CA1317177C - Single use syringe - Google Patents
Single use syringeInfo
- Publication number
- CA1317177C CA1317177C CA000606993A CA606993A CA1317177C CA 1317177 C CA1317177 C CA 1317177C CA 000606993 A CA000606993 A CA 000606993A CA 606993 A CA606993 A CA 606993A CA 1317177 C CA1317177 C CA 1317177C
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- Prior art keywords
- chamber
- valve
- sub
- syringe
- piston
- Prior art date
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Abstract
ABSTRACT
A single use syringe having an interacting piston and cylinder which cooperate to define a variable volume working space, the syringe includes a valve body located in the chamber so as to divide the chamber into a first and second sub-chamber, the valve body has valves which permit a liquid to be initially drawn into the syringe and then injected, but prevent a subsequent liquid being drawn into the syringe.
A single use syringe having an interacting piston and cylinder which cooperate to define a variable volume working space, the syringe includes a valve body located in the chamber so as to divide the chamber into a first and second sub-chamber, the valve body has valves which permit a liquid to be initially drawn into the syringe and then injected, but prevent a subsequent liquid being drawn into the syringe.
Description
t 31 7 1 77 The invention relates to hypodermic syringes and in particular to d single use hypodermic syringe Disposable syringes for which a single use is contemplated are well known as for exarple syringes for the injection of insulin in diabetics.
Nothing, ho~ever. prevents these syringes from being reused in a necessarily unsterile state. The result that contamination syringes when used contribute to the spreading of disease such as AIDS or hepatiti,.
Accordingl~ is desirable for syringes to be designed for a single use only to inhibit their re-use and therefore the risk of using contaminated syringes.
Previously kno~,ln single use syringes usually incorporate a modification of the piston of the syringe so that it is jammed in its fully inserted position adjacent the needle. These previousl~ known devic2s ~ave the disadvantage th~t the piston can become inadvertently jammed priol ~o a liquid being dra~- into the c~linder of the sylinge Described in British Patent 1,550,310 and French Patent 2,348,7C8 is a single use syringe The syringe has a detachable piston ~hich prevents re-use of the syringe. Once the piston has been moved to the minimum volume position, movement of the piston to again draw in a liquid is ~0 prohibited since the piston rod becomes detached from the piston head.
This syringe suffers from the disadvantage that the piston can become detached from the piston rod and the syringe cannot be operated to test whether the syringe has been correctly inserted. This is usually achieved by pulling back on the piston rod to draw into the syringe a small portion of blood. A similar syringe is disclosed in British Patent 2,015,883 again this particular device shows a detachable piston which suffers from the disadvantages as discussed.
French Patent 2,298,340 discloses a single use syringe, with the piston being provided with a frangible diaphragm. Once the piston has been moved to the minimum volume position, d bar penetrates the diaphragm -,~ 12U -2-"`` 1317177 preventing re-use of the syringe. British Patent 1,454,540 is of a similar construction, in that the piston is provided with a means of damaging the body of the syringe preventing its re-use. Both the syringes surfer from the disadvantage that they do not enable operation of the syringe to test whether the needle has been correctly located. ~3`~7 U.S. Patent 3,951,146 discloses a single use syrlnge which employs a ratchet mechanism to prevent withdrawal of the piston. Again this particular type of syringe does not enable testing to determine whether the needle has been correctly located. British Patent 2,184,657 also uses a pawl to engage behind the piston to prevent re-use. It has the same disadvantages. U.S. Patents 3,478,937 and 3,890,971 also employ pawls or detent members which prevent rearward movement of the piston. They suffer similar disadvantages.
U.S. Patent 4,233,975 discloses a single use syringe with a plunger mernber which engages within a socket when the piston is moved to the minimum volume position. The plunger cannot be retracted and prevents re-use of the syringe.
U.S. Patent 4,650,468 is similar to several of the above discussed patents since it also uses a plunger or piston which is automatically locked in a position preven-ting re-use.
The above-discussed previously known single use syringes suffer from the further disadvantage in that they require the piston to be moved to the minimum volume of position before any action is taken to render the syringe inoperative.
It is the object of the present invention to overcome or substantially ameliorate the above disadvantages.
There is disclosed herein a single use syringe comprising:
an inter-acting piston and cylinder defining a variable volume chamber within which a liquid to be injected is drawn;
a needle mounting at one end oE said cylinder, to receive a needle, a passage extending -through said mounting X
enabling liquid communication between said cylinder and said needle;
a piston rod attached to said piston and operable by a user to cause movement of said piston to vary the volume of said chamber;
a valve means including a valve body located within said chamber between said mounting and said piston and dividing said chamber into a first sub-chamber located between said mownting and valve means, and a second sub-chamber located between said valve means and said piston, said valve body being movable longitudinally of said cylinder between a first position and a second position, and said valve means includes a first valve which, when said body is in said first position, permits flow from said first sub-chamber to said second sub-chamber and prevents flow from said second sub-chamber to said first sub-chamber, but when said body is in said second position, said first valve permits flow from said second sub-chamber to said first sub-chamber and prevents flow from said first sub-chamber to said second sub-chamber, and a second valve which, when said body is in said first position, permits flow from said firs-t sub-chamber to said second sub-chamber, but prevents flow from said first sub-chamber to said second sub-chamber when said body is in said second position; and means to prevent movemen-t of said body from said second posi-tion to said first position.
There is further disclosed herein a valve assembly for a syringe having an interacting pis-ton and cylinder, with the cylinder terminating at one end with a mounting to receive a syringe needle, said pis-ton and cylinder cooperating to define a variable volume working chamber which receives a liquid to be injected by the syringe, said valve assembly being adapted to be located within said chamber so as to divide said chamber into a first sub-chamber located adjacent the needle mounting, and a second sub-chamber located adjacent the piston, said valve assembly including a valve sleeve to be sealingly received within said cylinder so as to be X
t 31 7 1 77 coaxial with respect thereto, said sleeve having an internal peripheral surfacei a movable valve member received within said sleeve and sealingly co-operating therewith so that in use of the syringe the valve member selectively controls the direction of flow of liquid within the syringe, said valve member having a pair of axially spaced annular sealing surfaces which sealingly engage said sleeve, and which are 0 resiliently deformable.;
a first set of sleeve projections extending inwardly of said sleeve to engage a first one of said sealing surfaces;
a second set of sleeve projections extending inwardly of said sleeve to engage the other sealing surface, said second set of sleeve projections being spaced longitudinally of said first set of sleeve projections; and wherein said valve member is longitudinally movable between a first portion wherein the first annular sealing surface is engaged with the first set of sleeve projections so as to be deformed and deflected from said sleeve so that liquid may pass thereby, and the other sealing surface is in sealing contact with said sleeve and inhibits the direction of fluid flow in a first direction, and a second position wherein said second sealing surface is enga~ed with said second set of sleeve projections so that liquid may pass thereby, and said first sealing surface is sealingly engaged with said sleeve to inhibit fluid flow in a second direction, which is opposite to said first direction.
Also in accordance with the present invention, there is provided a valve for a single use syringe having an interacting piston and cylinder and a syringe needle. The valve comprises duct means providing a passage through which liquid to be injected must pass to be delivered to the needle. The valve also comprises a movable valve body located in the duct means and dividing the passage into a first sub-chamber and a second sub-chamber, with the first sub-chamber to be located closer to the needle than the second sub-chamber.
The valve body is movable longitudinally of the duct means between a first position and a second position 20 under the influence of pressure applied thereto by the liquid. The valve body includes a first valve means sealingly co-operating with the duct means and which, when the body is in the first position, permits flow from the first sub-chamber to the second sub-chamber and prevents flow from the second sub-chamber to the first sub-chamber. However, when the body is in the second position, the first valve -5a-~ 3 1 7 1 7~
means permits flow from the second sub-chamber to the first sub-chamber. The valve body also includes a second valve means which, when the body is in the first position, permits flow from the first sub-chamber to the second sub-chamber but prevents flow from the first sub-char~er to the second sub-chamber when the body is in the second position. Means are provided to prevent movement of the body from the second position to the first position.
A preferred form of thQ present invention will now be described by way of exampl~ with reference to accompanying drawings, wherein:
Figure l is a schematic perspective part section view of a single use syrinye;
Figure 2 is a schematic section side elevation of a portion of the syringe of Figure 1 in a first operative mode;
Figure 3 is a schematic sectioned side elevation of the syringe -5b-portion of Figure 2;
Figure 4 is a schematic sectioned side elevation of the syringe portion of Figure 2 in a second opera-tive position;
Figure 5 is a schematic side elevation of an alternative syringe to that shown in Figure l;
Figure 6 is a schematic part sectioned perspective view of a single use syringe;
Figure 7 is a schematic sectioned side elevation of a portion of the syringe of Figure 6, with -the syringe in a first mode of operation;
Figure 8 is a schematic sectioned side elevation of the portion of Figure 7, with the syringe in a second mode of operation;
Figure 9 is a schematic sectioned side elevation of the portion of Figure 7 sectioned along the line 9-9;
Figure 10 is a schematic sectioned side elevation oE a portion of a syringe;
Figure 11 is a schematic end elevation of the portion of Figure 10;
Figure 12 is a schematic side elevation of a further syringe portion;
Figure 13 is a schematic end elevation of the portion of Figure 12; and Figures 14 to 17 schematically depict a val-ve assernbly.
In the preferred ernbodimen-t of the invention shown in Figures 1 to 5, the valve has been incorporated in the needle portion 3 of a syringe, the syringe main body portion 1 and needle portion 3 being made preferably as separate pieces. The valve includes a sliding portion 10 comprising a cylindrical body 14, at the opposite ends of which peripheral seals 34 and 36 are provided. Flexible flaps 17 and 19 extend from opposite ends and at diametrically opposed sections from arms 15 and 16 of cylindrical body 14. In cooperation with the wall 13 of the syringe flap 19 acts as an inlet valve while the flap 17 acts as an outlet valve in a manner to be described below.
The wall 13 includes two outwardly extending portions 8 and 9. Portion 8 has a sloping portion extending from point 24 to point 32 to - 6a -provide channel 18. The portion 9 has a sloping portion from point 22 to point 23 to provide channel 21. The wall 13 is also provided with a portion 28 extending towards the needle 4 from point 22, ending in a shoulder 25 which forms a stop for the body 14 in a manner tc be explained below.
The flaps 17 and 19 are made of such a resilient material that in their resting stdte as shown in Fig. 2 they lie against the ~all 13. The flaps 17 and 19 as shown in Figs. 1, 2 and 4 are shaped so as to provide a sealing action not only agdinst wall 13 within channels 18 an~ 21 but also against the side wdlls of these channels.
At approxilnately right angles to the flaps 17 and l9a p~ir of fingers 30 and 31 is provided as best shown in Fig. 3. These fingers extend froln the body 14 near ,eal means 36 and at the end of sliding port~on 10 distal of the needle tip 4. Finge,^s 30 and 31 extend into channels ~0 and 51, which are intel-lupted by inclined surfaces 53 and 55 wnich le~d to forwardly facing shoulders 45. The fingers 30 dnd 31 are sui~ably resilient to enable them to bend upon motion of the sliding portion 10 in the forward direction of arrow 42 so that upon passing the shoulder 45 they re-enter the channels 50 and 51 and thereby prevent return movement of the 20 valve body 10. In addition, the fingers 30 and 31 help to centre the body 10 within the wall 13, for example, by seating against the inclined surfaces 53 and in their initial state.
The operation of the valve will now be described with particular reference to Figs. 2, 3 and 4. The drawing o-f fluid into the needle 4 in the direction of arrow 40 will cause the flap 19 to move away from the wall in the channel 21, allowing fluid past the cylindrical body 14 via channel 21. The flap 19 will remain open as long as the filing stroke continues.
Once the desired dose has been drawn up the plunger 2 is moved in the direction of arrow 42. This initiates an expulsion stroke. The pressure of fluid being forced in the direction of arrow 42 by the plunger 2 in the FlF/~12U -7-~ 1317177 main body portion 1 of the syringe causes the flap 19 to seat against the surface of the fixed por-tion 13. The cylindrical part 14 is driven in the direction of arrow 42 by fluid pressure. This forces the seal 34 of the body 14 against point 22 to completely close channel 21 while dragging flap 19 therealong. Further motion in the direction of arrow 42 can continue until the body 14 presses against should 25 to be stopped thereby (Fig. 4).
Once the seal 36 of the cylindrical part 14 has cleared the point 32 fluid pressure ~;/ill open the flap 17 to allow expulsion of fluid through the needle top portion 4. Concurrently the fingers 30 and 31 become engaged forwar-d of the ;houlders 45. The expulsion stroke of the syringe is completed as desired.
Refilling of the syringe is now prevented. Flap ~ill allow expulsion of the contents of a sy!in~2 but upon initiation of a stroke in the direction of ar,ow 40 the Flap 17 will engage the wall 13 preventing the fi11ing of the syringe, ~hile the body 14 moves slightly in the direction of arrow 40 until engagement of the fingers 30 and 31 with the shoulders 45 prevents further movement of the body 14. The body 14 is then then located with the seal ,6 in contact with the wall 13 at point 32 so that the flow of fluid in the direction of arrow 40 is prevented. This effectively limits the syringe having these valve means to being used for single filling and expulsion stroke.
The material used for the body 14, the flaps 17, 19 and the fingers 30 and 31 may be any suitably resilient and pharmacologically acceptable material such dS nonprene.
Through the preferred embodiment shows the invention in the needle portion of a syringe other ways of carrying out the invention are also contemplated. For example, the valve means of the invention can be provided in the neck portion 5, the end portion of the main body portion 1, or in a needle ~ortion 3 integral with the main body of a syringe. The valve means can also be provided as a separate module in any of the . lr /61 2U -~-portions 3, 5 or 6, or as a module which is securely fixed at manufacture intermediate the neck portion S and the needle portion 3 of a syringe, as illustrated in figure 5. The main body portion 1, the valve means 7 and the needle portion 3 in the latte case thereby forming a single integral unit~ Equall. the valve means 7 -an be fi~ed to the neck portion 5, or the needle portion 3 separately for co-operation with a needle por-tion 3 or a neck portion '6 respectively of a ;yringe ~ Ihen thr valve means is use~ as a separate module within region 6 of the main body ~ortion 1 of a syringe, it is to be understood that the module can be nse!ted as a plug~ the size o-f which can be standardised and fitted to vari~usly sized syringei by slee~/es or other suitable fi~ing or securing means.
~n any c~ the above situat~ns there is a possibilitly that ~h^
syringe may be re-useable if the ~lunger portion 2 is withdrawn and ~he syringe fillea from the rear. Tc pr-event this situation the rear end o-f the main body ~ortion 1 through ~.J~ich the plunger is inserted can be crimped or heat staked after the plunger has been inserted at manufacture~
Egually, stop means can be provia d to prevent false operation of the valve means during transit~
In Figures 6 to 9 of the accompanying drawings there is schematically depicted a syringe 110 comprising an interacting cylinder 111 and piston 112 which co-operate to define a iealed chamber 113 The leading portion of the cylinder 112 is closed by a needle mounting 114 which receives a syringe needle 115.
Extending rearwardly from the piston 112 is a piston rod 116 e~tending to an end flange 117~ The end of the cylinder 111 is provided with a pair of flanges 118 which are gripped by the user together with the flange 117. The piston 112 is provided with one or more sealing rings 119.
Located within the chamber 113 is a novable valve member 120 which is slidably received by the internal cylindrical surface of the cylinder 111, F~F/612U -9-and divides the chamber 113 into two sub-chambers 121 and 122. The sub-chamber 121 being located adjacent the needle mounting 114, while the sub-chamber 122 is located between the piston 112 and the valve assembly 120.
The valve member 120 includes a main body 123 uF~n which there is mounted a pair of valve flaps 124 and 125 as well as a pair of pawl members 126.
The internal peripheral surface of the cylinder 111 is provided with shaped recesses 127 which slidably réceive the valve flaps 125, and shaped 10 recesses 128 which r-eceive the pawl melnbers 126.
The internal peripheral surface of the cylinder ?11 is also provided with abutments 129 which are positioned to be engaged -)y ~he pawl members 126.
The valve member- 120 is longitudinallv slidablv novable within the cylinder 111 so as to be mcvable between a first operative position as shown in Figure 7~ and a second operative position as shown in Figure 3.
In the operative position of Figure 2. a user of the syringe can increase the volume of the chamber 113 by moving the piston away from the needle 113. A liquid is then drawn in through the needle into the chamber 113 and 20 is allowed to pass between the sub-chambers 121 and 122 via inward deflection of the valve flap 125. The valve flap 125 deflects towards the longitudinal axis 30 of the cylinder 111. Once a desired amount of liquid has been drawn into the syringe 110, the needle 115 is inserted and the piston 112 moved towards the needle 115. As the pressure in the chamber 122 increases, the valve flap 125 is forced into sealing engagement with the internal peripheral surface of the cylinder 111. This pressure further causes movement of the valve member 120 towards the needle 115 until the body 123 abuts a step 131, as shown in Figure 3. Further movement of the piston 112 then causes the liquid to move past the body 123 to cause inward 30 deflection of the valve flap 124 towards the longitudinal axis 130.
F?F/612U -10-away from the cylindl-ical wall 231. Once the desired amount of liquid has been drawn into the syringe the needle ls oriented vertically and air expelled~ ~lovement of the piston to achieve this moves the valve member 235 to a position such that the end ~.~all 237 is forward of the projections 2qO. However the end wall 236 is engaged by the projections Z40 and is deformed to enable liquid to pass thereby and between the end wall 237 and -the internal peripheral sur-face of the cylindrical wall 231.
Once the needle has been inserted the piston is moved so dS to minimize the volume of the chamber 232 ~.~ith the liquid again passing by ~he deformed end wall 236 and past the end wall 237.
Re-use of the syringe is inhibited since movement of the piston again in the direction 241 moves the valve member- 235 to bring the end wall 23 back into ~ealing con act ~lith the annular lip 239.
The ~lve member 235 is permitted a certain degree of movement bef~re the end ~.~al~ 237 is moved back into ealing contact ~.lith the annular lip 239 to enaole the syringe to be inserted and a smaller amount of blood drawn into the syringe to indicate whether the needle has been correctl~
located.
In Figures 14 to 17 of the accompanying drawings there is schematically depicted a valve assembly 310 to be mounted within the end portion 311 of a syringe. The end portion 311 includes a needle mounting 312 to receive a syringe needle 313. The end portion 311 includes a generally cylindrical section 314 which if need be may be slightly tapered so as to be "frustoconical" in configuration. Extending from the cylindrical portion 314 is the main body 315 of the syringe which slidably sealingly receives the piston (not illustrated).
The cylindrical section 314 receives the valve assembly 310. The valve assembly 310 includes a valve sleeve 316 which has an outer peripheral surface sealingly mated with the internal peripheral surface of the cylindrical section 314. The internal peripheral sur-face 317 slidably F~]F/fil~!J ~ 4 1 3 1 7 1 7`7 In the position shown in Figure 3 it should be appreciated tha-t the body 123 is in sealing engagement with the internal peripheral surface of the cylinder 111 apart -From the recess 127 which is selectively closed by the valve flap 124.
When the valve assembly 120 is in the position shown by Fiyure 3, -the pawl members 126 are located forward of the abutments 129. Accordingly, if an attempt is made to re-use the syringe by again moving the piston 112 away from the needle 115, the valve member will not return to the position as shown in Figure 2. However, while in the position of Figure 3, the 10 valve flap 124 prohibits liquid being drawn into the chamber 113 and therefor the sub-chamber 122 is sealingly cut off from the sub-chamber 121.
It is desirable in some instances to ensure that the needle 125 has been correctly located by drawing into the syringe 110 a small amount of blood. This is done af-ter the syringe has been filled with a liquid to be injected. To provide for this, the step 131 is located relative to the abutments 129 such that a small movement of the valve member 120 away From the needle 115 is possible until the pawl members 26 engage the abutments 129.
In Figures 10 and 11 of the accompanying drawings, there is schematically depicted a portion 210 of a syringe. The syringe includes a cylindrical wall 111 which sealingly slidably receives a piston which is not illustrated. One end of -the chamber 212 is closed by the piston, while the other end of the chamber 212 is closed by a needle mounting. The chamber 212 is divided into two sub-chambers 213 and 214 by means of a valve member 215. The valve member 215 is formed of flexible resilient material and is provided with a first Flexible end wall 216, and a second end wall 217.
The cylindrical wall 211 has an internal peripheral surface provided with an annular lip 218 and at least one longitudinally extending 30~ projection 219. The projections 219 extend longitudinally from the lip 218 F.!F/61 ,IJ
"`' ' `' ~ `' ' ' '' ' I :, towards the piston.
Located forward from the lip 218 towards the needle mounting, is at least one projection 220.
In oFeration of the syringe described with reference to Figures 10 and ll,initial y the valve member 215 is located engaged by the projections 219 so that the end wall 217 is at least partly deformed, as best seen in Figure 2. The piston is also located so that the chamber 212 has a minimum volume. Thereafter, a liquid to be injected is drawn into the syringe by the piston being moved away from the valve member 215 in the direction of the arrow 2 1. Once the desired amount of liquid is contained within the syringe, the needle is oriented vertically and air expelled from within the syringe. It should be appreciated that the vast majority oF the liquid to be injected is located in the sub-chamber 214. The liquid is allcwed to enter the sJb-chamber 214 by passing around the deformed end wall _17 and causing deflection of the end wall 216.
Once the desired amount of liquid is located in the syringe. the needle is oriented vertically and air expelled from within the syringe.
This operation will move the valve member 215 to a position located closer to the needle moun-ting. More particularly, the end wall 217 is moved from engagement with the projections 219, and abuts the projec-tions 220. When in this position, the end wall 216 is engaged by the projections 219. It should be appreciated that this forward movement of the valve member 215 is caused by the pressure within the liquid, applied against the end wall 216.
Once the syringe needle has been inserted, and the pis-ton moved to inject the liquid, the liquid moves past the deformed end wall 216 and around past the annular space eNisting between the internal per-ipheral wall oF the cylinder 211 and the end wall 217. This deformation of the end wall 216 is caused by the engagement between the end wall 216 and the projections 219.
, Further use of the syr-inge. by movement oF the piston again in the : . r, F IF/~.I IJ
direction of the arrow 221 is prevented by the valve member 215 being moved in the direction of the arrow 221 until the valve member sealingly engages the annular lip 218. Since insufficient -force can be applied to the valve member 215 to cause deformation thereof by englgement with the projections 219, further use of the syringe is inhibited.
It should be appreciated that the projections 220 are spaced from the projections 219 so that a certain amount of mcvement of the valve member 215 is permitted until the end wall 217 sealingly contacts the lip 218.
This enables the syringe needle to be inserted in a vein and the piston drawn back, a limited amount, to draw in a sma~l quantity of blood to thereby detect whether the syringe needle has been correctly inserted.
In Figures 12 and 13 there is schematically depicted a portion 230 of a syringe. In this particular embodiment, the s!ringe has a cylindrical wall 231 encompassing a chamber 232. The chamber i; closed at one end by means of a piston, while the other end is closed by ~ needle mounting.
The chamber 232 is divided into two sub--hambers 233 and 234 by means of a valve member 235. The valve member 235 is formed of flexible resilient material and has a pair of end walls 236 and 237. The end walls 236 and 237 are joined by a stem 238.
The internal peripheral surface of the wall 231 is provided with an annular lip 239 as well as at least one longitudinally extending projection 240.
In the position depicted in Figures 12 and 13, the end wall 217 is engaging the projections 240 so as to be deformed thereby.
Initially, the valve member 235 is located in the position depicted in Figure 3. The piston is located so that the volume of the chamber 232 is minimi~ed. To draw a liquid into the syringe, the piston is moved in the direction of the arrow 241 away from the valve member 235. The liquid is drawn into the sub-chamber 234 via movement of the liquid past the end wa.ll 237~ due to its deformation. and the deflecticn of the end wall 236 F'F/f 12ll i 3 1 7 1 77 receives a movable valve member 318. The valve member 318 iS of a unitary construction, and is preferably moulded or formed from a resilient elastic material. The valve member 318 has a pair o-f annular sealing flanges 319 and 320 which provide sealing surfaces which slidably engage the surface 317.
The surface 317 iS provided with t~"o sets of projections 321 and 322, with the set of projections 321 being located closer to the needle than the second set of projections 322. The first set of projections 321 include two projections which are located on diametrically opposite sides of the surface 317, and are coextensive and parallel. The second set of projections 322, which are longitudinally spaced from the first set of projections 321 toward the rear of the syringe, also include a pair of projections, which are located on diametrically oppciite sides of the surface 317, and are coextensive and parallel. The rojections 322 are spaced 90 degrees angularly about the longitudinal ~xis 331, from the projections 321.
As best seen in Figures 14 and 15, each of the projections 321 and-322 has a leading face 323 which may be generally normal to the surface 317, or slightly inclined thereto so as to provide a barb which will engage the 2~ movable.valve member 318. The rear end of each projection 321 and 322 iS
provided by a ramp surface 324.
The valve member 318 is provided with an annular recess 325 with a leading surface 326. The recess 325 has a rear surface 327. The surface 326 extends generally normal to the longi-tudinal axis 331, while the surface 327 is inclined to the axis 331 by an acute angle.
Each of the projections 321 iS provided with a longitudinally extending passage 328 through which d liquid to be injected may pass.
In operation of the above described valve assembly 310, the movable valve member 318 begins in a starting position as seen in Figures 14 and 15.
The projections 322 are engaged with the flange 319 so tnat the flange 319 ... l` - .
is resiliently deformed so -that portions -thereof are spaced from the surface 317 so that the flange 319 is no longer in sealing contact with the surface 317. When the piston of the syringe is located adjacent the valve assembly 310 and moved in the direction of the arrow 330, a liquid is drawn in through the needle 313, pass the flange 319, and due to the pressure differential across the flange 320, the flange 320 deflects from a sealing contact with the surface 317, and permits the liquid to enter the main chamber 332 of the syrirge. When the desired amount o-f liquid has been drawn into the syringe, and the operator wishes to expel any air contained in the syringe, the needle 313 is placed so as to extend vertically.
Thereafter, any air contlined in the syringe will move upwardly. The operator then moves the jiston or plunger to expel the air. When the piston moves, the pressu~e within the liquid within the chamber 331 causes the valve member 318 to ~ove towards the needle 313, so that the flange 319 moves from operative contact with the projections 322. When this occurs, the flange 320 moves in contact with the projections 321. Accordingly, the flange 320 is moved from sealing contact with the surface 317. The liquid then is able to pass the flange 320 and cause deflection of the flange 320 to pass towards the needle 313. This position is shown in Figure 2.
In some instances it is desirable to test to determine whether the needle has been correctly inserted. This is achieved by drawing back on the piston and drawing into the syringe a small amount of blood. This test can be carried out due to the distance between the surface 326 and the surface 323, which distance. permits a small amount of rearward movement of valve member 318. When the piston is drawn back, the movable valve member 318 moves until the surface 326 engages the surfaces 323 of the projections ~21. Once this has occurred, the movable valve member 318 is prevented from any -fur-ther rearward movement. Once in this position, the flanges 319 -are in sealirg contact with the surface 317 and prevent any further material being drawn into the syringe. To inject the liquid contained F ~ F / f; 1 2 U
within the chamber 332, again the piston is moved forward towards -the needle 313. The pressure in the liquid then deflects the Flanges 319 away from the surfac~ 317 so that the liquid can then reach the needles 313.
Re-use of the syringe is inhibited since once the syringe has been used7 the surface 326 is located forward of the surfaces 323 of the projections 321. Once this has occurred, the valve member 318 prevents any liquid being drawn irto the chamber 332.
FJF/~l'IJ
Nothing, ho~ever. prevents these syringes from being reused in a necessarily unsterile state. The result that contamination syringes when used contribute to the spreading of disease such as AIDS or hepatiti,.
Accordingl~ is desirable for syringes to be designed for a single use only to inhibit their re-use and therefore the risk of using contaminated syringes.
Previously kno~,ln single use syringes usually incorporate a modification of the piston of the syringe so that it is jammed in its fully inserted position adjacent the needle. These previousl~ known devic2s ~ave the disadvantage th~t the piston can become inadvertently jammed priol ~o a liquid being dra~- into the c~linder of the sylinge Described in British Patent 1,550,310 and French Patent 2,348,7C8 is a single use syringe The syringe has a detachable piston ~hich prevents re-use of the syringe. Once the piston has been moved to the minimum volume position, movement of the piston to again draw in a liquid is ~0 prohibited since the piston rod becomes detached from the piston head.
This syringe suffers from the disadvantage that the piston can become detached from the piston rod and the syringe cannot be operated to test whether the syringe has been correctly inserted. This is usually achieved by pulling back on the piston rod to draw into the syringe a small portion of blood. A similar syringe is disclosed in British Patent 2,015,883 again this particular device shows a detachable piston which suffers from the disadvantages as discussed.
French Patent 2,298,340 discloses a single use syringe, with the piston being provided with a frangible diaphragm. Once the piston has been moved to the minimum volume position, d bar penetrates the diaphragm -,~ 12U -2-"`` 1317177 preventing re-use of the syringe. British Patent 1,454,540 is of a similar construction, in that the piston is provided with a means of damaging the body of the syringe preventing its re-use. Both the syringes surfer from the disadvantage that they do not enable operation of the syringe to test whether the needle has been correctly located. ~3`~7 U.S. Patent 3,951,146 discloses a single use syrlnge which employs a ratchet mechanism to prevent withdrawal of the piston. Again this particular type of syringe does not enable testing to determine whether the needle has been correctly located. British Patent 2,184,657 also uses a pawl to engage behind the piston to prevent re-use. It has the same disadvantages. U.S. Patents 3,478,937 and 3,890,971 also employ pawls or detent members which prevent rearward movement of the piston. They suffer similar disadvantages.
U.S. Patent 4,233,975 discloses a single use syringe with a plunger mernber which engages within a socket when the piston is moved to the minimum volume position. The plunger cannot be retracted and prevents re-use of the syringe.
U.S. Patent 4,650,468 is similar to several of the above discussed patents since it also uses a plunger or piston which is automatically locked in a position preven-ting re-use.
The above-discussed previously known single use syringes suffer from the further disadvantage in that they require the piston to be moved to the minimum volume of position before any action is taken to render the syringe inoperative.
It is the object of the present invention to overcome or substantially ameliorate the above disadvantages.
There is disclosed herein a single use syringe comprising:
an inter-acting piston and cylinder defining a variable volume chamber within which a liquid to be injected is drawn;
a needle mounting at one end oE said cylinder, to receive a needle, a passage extending -through said mounting X
enabling liquid communication between said cylinder and said needle;
a piston rod attached to said piston and operable by a user to cause movement of said piston to vary the volume of said chamber;
a valve means including a valve body located within said chamber between said mounting and said piston and dividing said chamber into a first sub-chamber located between said mownting and valve means, and a second sub-chamber located between said valve means and said piston, said valve body being movable longitudinally of said cylinder between a first position and a second position, and said valve means includes a first valve which, when said body is in said first position, permits flow from said first sub-chamber to said second sub-chamber and prevents flow from said second sub-chamber to said first sub-chamber, but when said body is in said second position, said first valve permits flow from said second sub-chamber to said first sub-chamber and prevents flow from said first sub-chamber to said second sub-chamber, and a second valve which, when said body is in said first position, permits flow from said firs-t sub-chamber to said second sub-chamber, but prevents flow from said first sub-chamber to said second sub-chamber when said body is in said second position; and means to prevent movemen-t of said body from said second posi-tion to said first position.
There is further disclosed herein a valve assembly for a syringe having an interacting pis-ton and cylinder, with the cylinder terminating at one end with a mounting to receive a syringe needle, said pis-ton and cylinder cooperating to define a variable volume working chamber which receives a liquid to be injected by the syringe, said valve assembly being adapted to be located within said chamber so as to divide said chamber into a first sub-chamber located adjacent the needle mounting, and a second sub-chamber located adjacent the piston, said valve assembly including a valve sleeve to be sealingly received within said cylinder so as to be X
t 31 7 1 77 coaxial with respect thereto, said sleeve having an internal peripheral surfacei a movable valve member received within said sleeve and sealingly co-operating therewith so that in use of the syringe the valve member selectively controls the direction of flow of liquid within the syringe, said valve member having a pair of axially spaced annular sealing surfaces which sealingly engage said sleeve, and which are 0 resiliently deformable.;
a first set of sleeve projections extending inwardly of said sleeve to engage a first one of said sealing surfaces;
a second set of sleeve projections extending inwardly of said sleeve to engage the other sealing surface, said second set of sleeve projections being spaced longitudinally of said first set of sleeve projections; and wherein said valve member is longitudinally movable between a first portion wherein the first annular sealing surface is engaged with the first set of sleeve projections so as to be deformed and deflected from said sleeve so that liquid may pass thereby, and the other sealing surface is in sealing contact with said sleeve and inhibits the direction of fluid flow in a first direction, and a second position wherein said second sealing surface is enga~ed with said second set of sleeve projections so that liquid may pass thereby, and said first sealing surface is sealingly engaged with said sleeve to inhibit fluid flow in a second direction, which is opposite to said first direction.
Also in accordance with the present invention, there is provided a valve for a single use syringe having an interacting piston and cylinder and a syringe needle. The valve comprises duct means providing a passage through which liquid to be injected must pass to be delivered to the needle. The valve also comprises a movable valve body located in the duct means and dividing the passage into a first sub-chamber and a second sub-chamber, with the first sub-chamber to be located closer to the needle than the second sub-chamber.
The valve body is movable longitudinally of the duct means between a first position and a second position 20 under the influence of pressure applied thereto by the liquid. The valve body includes a first valve means sealingly co-operating with the duct means and which, when the body is in the first position, permits flow from the first sub-chamber to the second sub-chamber and prevents flow from the second sub-chamber to the first sub-chamber. However, when the body is in the second position, the first valve -5a-~ 3 1 7 1 7~
means permits flow from the second sub-chamber to the first sub-chamber. The valve body also includes a second valve means which, when the body is in the first position, permits flow from the first sub-chamber to the second sub-chamber but prevents flow from the first sub-char~er to the second sub-chamber when the body is in the second position. Means are provided to prevent movement of the body from the second position to the first position.
A preferred form of thQ present invention will now be described by way of exampl~ with reference to accompanying drawings, wherein:
Figure l is a schematic perspective part section view of a single use syrinye;
Figure 2 is a schematic section side elevation of a portion of the syringe of Figure 1 in a first operative mode;
Figure 3 is a schematic sectioned side elevation of the syringe -5b-portion of Figure 2;
Figure 4 is a schematic sectioned side elevation of the syringe portion of Figure 2 in a second opera-tive position;
Figure 5 is a schematic side elevation of an alternative syringe to that shown in Figure l;
Figure 6 is a schematic part sectioned perspective view of a single use syringe;
Figure 7 is a schematic sectioned side elevation of a portion of the syringe of Figure 6, with -the syringe in a first mode of operation;
Figure 8 is a schematic sectioned side elevation of the portion of Figure 7, with the syringe in a second mode of operation;
Figure 9 is a schematic sectioned side elevation of the portion of Figure 7 sectioned along the line 9-9;
Figure 10 is a schematic sectioned side elevation oE a portion of a syringe;
Figure 11 is a schematic end elevation of the portion of Figure 10;
Figure 12 is a schematic side elevation of a further syringe portion;
Figure 13 is a schematic end elevation of the portion of Figure 12; and Figures 14 to 17 schematically depict a val-ve assernbly.
In the preferred ernbodimen-t of the invention shown in Figures 1 to 5, the valve has been incorporated in the needle portion 3 of a syringe, the syringe main body portion 1 and needle portion 3 being made preferably as separate pieces. The valve includes a sliding portion 10 comprising a cylindrical body 14, at the opposite ends of which peripheral seals 34 and 36 are provided. Flexible flaps 17 and 19 extend from opposite ends and at diametrically opposed sections from arms 15 and 16 of cylindrical body 14. In cooperation with the wall 13 of the syringe flap 19 acts as an inlet valve while the flap 17 acts as an outlet valve in a manner to be described below.
The wall 13 includes two outwardly extending portions 8 and 9. Portion 8 has a sloping portion extending from point 24 to point 32 to - 6a -provide channel 18. The portion 9 has a sloping portion from point 22 to point 23 to provide channel 21. The wall 13 is also provided with a portion 28 extending towards the needle 4 from point 22, ending in a shoulder 25 which forms a stop for the body 14 in a manner tc be explained below.
The flaps 17 and 19 are made of such a resilient material that in their resting stdte as shown in Fig. 2 they lie against the ~all 13. The flaps 17 and 19 as shown in Figs. 1, 2 and 4 are shaped so as to provide a sealing action not only agdinst wall 13 within channels 18 an~ 21 but also against the side wdlls of these channels.
At approxilnately right angles to the flaps 17 and l9a p~ir of fingers 30 and 31 is provided as best shown in Fig. 3. These fingers extend froln the body 14 near ,eal means 36 and at the end of sliding port~on 10 distal of the needle tip 4. Finge,^s 30 and 31 extend into channels ~0 and 51, which are intel-lupted by inclined surfaces 53 and 55 wnich le~d to forwardly facing shoulders 45. The fingers 30 dnd 31 are sui~ably resilient to enable them to bend upon motion of the sliding portion 10 in the forward direction of arrow 42 so that upon passing the shoulder 45 they re-enter the channels 50 and 51 and thereby prevent return movement of the 20 valve body 10. In addition, the fingers 30 and 31 help to centre the body 10 within the wall 13, for example, by seating against the inclined surfaces 53 and in their initial state.
The operation of the valve will now be described with particular reference to Figs. 2, 3 and 4. The drawing o-f fluid into the needle 4 in the direction of arrow 40 will cause the flap 19 to move away from the wall in the channel 21, allowing fluid past the cylindrical body 14 via channel 21. The flap 19 will remain open as long as the filing stroke continues.
Once the desired dose has been drawn up the plunger 2 is moved in the direction of arrow 42. This initiates an expulsion stroke. The pressure of fluid being forced in the direction of arrow 42 by the plunger 2 in the FlF/~12U -7-~ 1317177 main body portion 1 of the syringe causes the flap 19 to seat against the surface of the fixed por-tion 13. The cylindrical part 14 is driven in the direction of arrow 42 by fluid pressure. This forces the seal 34 of the body 14 against point 22 to completely close channel 21 while dragging flap 19 therealong. Further motion in the direction of arrow 42 can continue until the body 14 presses against should 25 to be stopped thereby (Fig. 4).
Once the seal 36 of the cylindrical part 14 has cleared the point 32 fluid pressure ~;/ill open the flap 17 to allow expulsion of fluid through the needle top portion 4. Concurrently the fingers 30 and 31 become engaged forwar-d of the ;houlders 45. The expulsion stroke of the syringe is completed as desired.
Refilling of the syringe is now prevented. Flap ~ill allow expulsion of the contents of a sy!in~2 but upon initiation of a stroke in the direction of ar,ow 40 the Flap 17 will engage the wall 13 preventing the fi11ing of the syringe, ~hile the body 14 moves slightly in the direction of arrow 40 until engagement of the fingers 30 and 31 with the shoulders 45 prevents further movement of the body 14. The body 14 is then then located with the seal ,6 in contact with the wall 13 at point 32 so that the flow of fluid in the direction of arrow 40 is prevented. This effectively limits the syringe having these valve means to being used for single filling and expulsion stroke.
The material used for the body 14, the flaps 17, 19 and the fingers 30 and 31 may be any suitably resilient and pharmacologically acceptable material such dS nonprene.
Through the preferred embodiment shows the invention in the needle portion of a syringe other ways of carrying out the invention are also contemplated. For example, the valve means of the invention can be provided in the neck portion 5, the end portion of the main body portion 1, or in a needle ~ortion 3 integral with the main body of a syringe. The valve means can also be provided as a separate module in any of the . lr /61 2U -~-portions 3, 5 or 6, or as a module which is securely fixed at manufacture intermediate the neck portion S and the needle portion 3 of a syringe, as illustrated in figure 5. The main body portion 1, the valve means 7 and the needle portion 3 in the latte case thereby forming a single integral unit~ Equall. the valve means 7 -an be fi~ed to the neck portion 5, or the needle portion 3 separately for co-operation with a needle por-tion 3 or a neck portion '6 respectively of a ;yringe ~ Ihen thr valve means is use~ as a separate module within region 6 of the main body ~ortion 1 of a syringe, it is to be understood that the module can be nse!ted as a plug~ the size o-f which can be standardised and fitted to vari~usly sized syringei by slee~/es or other suitable fi~ing or securing means.
~n any c~ the above situat~ns there is a possibilitly that ~h^
syringe may be re-useable if the ~lunger portion 2 is withdrawn and ~he syringe fillea from the rear. Tc pr-event this situation the rear end o-f the main body ~ortion 1 through ~.J~ich the plunger is inserted can be crimped or heat staked after the plunger has been inserted at manufacture~
Egually, stop means can be provia d to prevent false operation of the valve means during transit~
In Figures 6 to 9 of the accompanying drawings there is schematically depicted a syringe 110 comprising an interacting cylinder 111 and piston 112 which co-operate to define a iealed chamber 113 The leading portion of the cylinder 112 is closed by a needle mounting 114 which receives a syringe needle 115.
Extending rearwardly from the piston 112 is a piston rod 116 e~tending to an end flange 117~ The end of the cylinder 111 is provided with a pair of flanges 118 which are gripped by the user together with the flange 117. The piston 112 is provided with one or more sealing rings 119.
Located within the chamber 113 is a novable valve member 120 which is slidably received by the internal cylindrical surface of the cylinder 111, F~F/612U -9-and divides the chamber 113 into two sub-chambers 121 and 122. The sub-chamber 121 being located adjacent the needle mounting 114, while the sub-chamber 122 is located between the piston 112 and the valve assembly 120.
The valve member 120 includes a main body 123 uF~n which there is mounted a pair of valve flaps 124 and 125 as well as a pair of pawl members 126.
The internal peripheral surface of the cylinder 111 is provided with shaped recesses 127 which slidably réceive the valve flaps 125, and shaped 10 recesses 128 which r-eceive the pawl melnbers 126.
The internal peripheral surface of the cylinder ?11 is also provided with abutments 129 which are positioned to be engaged -)y ~he pawl members 126.
The valve member- 120 is longitudinallv slidablv novable within the cylinder 111 so as to be mcvable between a first operative position as shown in Figure 7~ and a second operative position as shown in Figure 3.
In the operative position of Figure 2. a user of the syringe can increase the volume of the chamber 113 by moving the piston away from the needle 113. A liquid is then drawn in through the needle into the chamber 113 and 20 is allowed to pass between the sub-chambers 121 and 122 via inward deflection of the valve flap 125. The valve flap 125 deflects towards the longitudinal axis 30 of the cylinder 111. Once a desired amount of liquid has been drawn into the syringe 110, the needle 115 is inserted and the piston 112 moved towards the needle 115. As the pressure in the chamber 122 increases, the valve flap 125 is forced into sealing engagement with the internal peripheral surface of the cylinder 111. This pressure further causes movement of the valve member 120 towards the needle 115 until the body 123 abuts a step 131, as shown in Figure 3. Further movement of the piston 112 then causes the liquid to move past the body 123 to cause inward 30 deflection of the valve flap 124 towards the longitudinal axis 130.
F?F/612U -10-away from the cylindl-ical wall 231. Once the desired amount of liquid has been drawn into the syringe the needle ls oriented vertically and air expelled~ ~lovement of the piston to achieve this moves the valve member 235 to a position such that the end ~.~all 237 is forward of the projections 2qO. However the end wall 236 is engaged by the projections Z40 and is deformed to enable liquid to pass thereby and between the end wall 237 and -the internal peripheral sur-face of the cylindrical wall 231.
Once the needle has been inserted the piston is moved so dS to minimize the volume of the chamber 232 ~.~ith the liquid again passing by ~he deformed end wall 236 and past the end wall 237.
Re-use of the syringe is inhibited since movement of the piston again in the direction 241 moves the valve member- 235 to bring the end wall 23 back into ~ealing con act ~lith the annular lip 239.
The ~lve member 235 is permitted a certain degree of movement bef~re the end ~.~al~ 237 is moved back into ealing contact ~.lith the annular lip 239 to enaole the syringe to be inserted and a smaller amount of blood drawn into the syringe to indicate whether the needle has been correctl~
located.
In Figures 14 to 17 of the accompanying drawings there is schematically depicted a valve assembly 310 to be mounted within the end portion 311 of a syringe. The end portion 311 includes a needle mounting 312 to receive a syringe needle 313. The end portion 311 includes a generally cylindrical section 314 which if need be may be slightly tapered so as to be "frustoconical" in configuration. Extending from the cylindrical portion 314 is the main body 315 of the syringe which slidably sealingly receives the piston (not illustrated).
The cylindrical section 314 receives the valve assembly 310. The valve assembly 310 includes a valve sleeve 316 which has an outer peripheral surface sealingly mated with the internal peripheral surface of the cylindrical section 314. The internal peripheral sur-face 317 slidably F~]F/fil~!J ~ 4 1 3 1 7 1 7`7 In the position shown in Figure 3 it should be appreciated tha-t the body 123 is in sealing engagement with the internal peripheral surface of the cylinder 111 apart -From the recess 127 which is selectively closed by the valve flap 124.
When the valve assembly 120 is in the position shown by Fiyure 3, -the pawl members 126 are located forward of the abutments 129. Accordingly, if an attempt is made to re-use the syringe by again moving the piston 112 away from the needle 115, the valve member will not return to the position as shown in Figure 2. However, while in the position of Figure 3, the 10 valve flap 124 prohibits liquid being drawn into the chamber 113 and therefor the sub-chamber 122 is sealingly cut off from the sub-chamber 121.
It is desirable in some instances to ensure that the needle 125 has been correctly located by drawing into the syringe 110 a small amount of blood. This is done af-ter the syringe has been filled with a liquid to be injected. To provide for this, the step 131 is located relative to the abutments 129 such that a small movement of the valve member 120 away From the needle 115 is possible until the pawl members 26 engage the abutments 129.
In Figures 10 and 11 of the accompanying drawings, there is schematically depicted a portion 210 of a syringe. The syringe includes a cylindrical wall 111 which sealingly slidably receives a piston which is not illustrated. One end of -the chamber 212 is closed by the piston, while the other end of the chamber 212 is closed by a needle mounting. The chamber 212 is divided into two sub-chambers 213 and 214 by means of a valve member 215. The valve member 215 is formed of flexible resilient material and is provided with a first Flexible end wall 216, and a second end wall 217.
The cylindrical wall 211 has an internal peripheral surface provided with an annular lip 218 and at least one longitudinally extending 30~ projection 219. The projections 219 extend longitudinally from the lip 218 F.!F/61 ,IJ
"`' ' `' ~ `' ' ' '' ' I :, towards the piston.
Located forward from the lip 218 towards the needle mounting, is at least one projection 220.
In oFeration of the syringe described with reference to Figures 10 and ll,initial y the valve member 215 is located engaged by the projections 219 so that the end wall 217 is at least partly deformed, as best seen in Figure 2. The piston is also located so that the chamber 212 has a minimum volume. Thereafter, a liquid to be injected is drawn into the syringe by the piston being moved away from the valve member 215 in the direction of the arrow 2 1. Once the desired amount of liquid is contained within the syringe, the needle is oriented vertically and air expelled from within the syringe. It should be appreciated that the vast majority oF the liquid to be injected is located in the sub-chamber 214. The liquid is allcwed to enter the sJb-chamber 214 by passing around the deformed end wall _17 and causing deflection of the end wall 216.
Once the desired amount of liquid is located in the syringe. the needle is oriented vertically and air expelled from within the syringe.
This operation will move the valve member 215 to a position located closer to the needle moun-ting. More particularly, the end wall 217 is moved from engagement with the projections 219, and abuts the projec-tions 220. When in this position, the end wall 216 is engaged by the projections 219. It should be appreciated that this forward movement of the valve member 215 is caused by the pressure within the liquid, applied against the end wall 216.
Once the syringe needle has been inserted, and the pis-ton moved to inject the liquid, the liquid moves past the deformed end wall 216 and around past the annular space eNisting between the internal per-ipheral wall oF the cylinder 211 and the end wall 217. This deformation of the end wall 216 is caused by the engagement between the end wall 216 and the projections 219.
, Further use of the syr-inge. by movement oF the piston again in the : . r, F IF/~.I IJ
direction of the arrow 221 is prevented by the valve member 215 being moved in the direction of the arrow 221 until the valve member sealingly engages the annular lip 218. Since insufficient -force can be applied to the valve member 215 to cause deformation thereof by englgement with the projections 219, further use of the syringe is inhibited.
It should be appreciated that the projections 220 are spaced from the projections 219 so that a certain amount of mcvement of the valve member 215 is permitted until the end wall 217 sealingly contacts the lip 218.
This enables the syringe needle to be inserted in a vein and the piston drawn back, a limited amount, to draw in a sma~l quantity of blood to thereby detect whether the syringe needle has been correctly inserted.
In Figures 12 and 13 there is schematically depicted a portion 230 of a syringe. In this particular embodiment, the s!ringe has a cylindrical wall 231 encompassing a chamber 232. The chamber i; closed at one end by means of a piston, while the other end is closed by ~ needle mounting.
The chamber 232 is divided into two sub--hambers 233 and 234 by means of a valve member 235. The valve member 235 is formed of flexible resilient material and has a pair of end walls 236 and 237. The end walls 236 and 237 are joined by a stem 238.
The internal peripheral surface of the wall 231 is provided with an annular lip 239 as well as at least one longitudinally extending projection 240.
In the position depicted in Figures 12 and 13, the end wall 217 is engaging the projections 240 so as to be deformed thereby.
Initially, the valve member 235 is located in the position depicted in Figure 3. The piston is located so that the volume of the chamber 232 is minimi~ed. To draw a liquid into the syringe, the piston is moved in the direction of the arrow 241 away from the valve member 235. The liquid is drawn into the sub-chamber 234 via movement of the liquid past the end wa.ll 237~ due to its deformation. and the deflecticn of the end wall 236 F'F/f 12ll i 3 1 7 1 77 receives a movable valve member 318. The valve member 318 iS of a unitary construction, and is preferably moulded or formed from a resilient elastic material. The valve member 318 has a pair o-f annular sealing flanges 319 and 320 which provide sealing surfaces which slidably engage the surface 317.
The surface 317 iS provided with t~"o sets of projections 321 and 322, with the set of projections 321 being located closer to the needle than the second set of projections 322. The first set of projections 321 include two projections which are located on diametrically opposite sides of the surface 317, and are coextensive and parallel. The second set of projections 322, which are longitudinally spaced from the first set of projections 321 toward the rear of the syringe, also include a pair of projections, which are located on diametrically oppciite sides of the surface 317, and are coextensive and parallel. The rojections 322 are spaced 90 degrees angularly about the longitudinal ~xis 331, from the projections 321.
As best seen in Figures 14 and 15, each of the projections 321 and-322 has a leading face 323 which may be generally normal to the surface 317, or slightly inclined thereto so as to provide a barb which will engage the 2~ movable.valve member 318. The rear end of each projection 321 and 322 iS
provided by a ramp surface 324.
The valve member 318 is provided with an annular recess 325 with a leading surface 326. The recess 325 has a rear surface 327. The surface 326 extends generally normal to the longi-tudinal axis 331, while the surface 327 is inclined to the axis 331 by an acute angle.
Each of the projections 321 iS provided with a longitudinally extending passage 328 through which d liquid to be injected may pass.
In operation of the above described valve assembly 310, the movable valve member 318 begins in a starting position as seen in Figures 14 and 15.
The projections 322 are engaged with the flange 319 so tnat the flange 319 ... l` - .
is resiliently deformed so -that portions -thereof are spaced from the surface 317 so that the flange 319 is no longer in sealing contact with the surface 317. When the piston of the syringe is located adjacent the valve assembly 310 and moved in the direction of the arrow 330, a liquid is drawn in through the needle 313, pass the flange 319, and due to the pressure differential across the flange 320, the flange 320 deflects from a sealing contact with the surface 317, and permits the liquid to enter the main chamber 332 of the syrirge. When the desired amount o-f liquid has been drawn into the syringe, and the operator wishes to expel any air contained in the syringe, the needle 313 is placed so as to extend vertically.
Thereafter, any air contlined in the syringe will move upwardly. The operator then moves the jiston or plunger to expel the air. When the piston moves, the pressu~e within the liquid within the chamber 331 causes the valve member 318 to ~ove towards the needle 313, so that the flange 319 moves from operative contact with the projections 322. When this occurs, the flange 320 moves in contact with the projections 321. Accordingly, the flange 320 is moved from sealing contact with the surface 317. The liquid then is able to pass the flange 320 and cause deflection of the flange 320 to pass towards the needle 313. This position is shown in Figure 2.
In some instances it is desirable to test to determine whether the needle has been correctly inserted. This is achieved by drawing back on the piston and drawing into the syringe a small amount of blood. This test can be carried out due to the distance between the surface 326 and the surface 323, which distance. permits a small amount of rearward movement of valve member 318. When the piston is drawn back, the movable valve member 318 moves until the surface 326 engages the surfaces 323 of the projections ~21. Once this has occurred, the movable valve member 318 is prevented from any -fur-ther rearward movement. Once in this position, the flanges 319 -are in sealirg contact with the surface 317 and prevent any further material being drawn into the syringe. To inject the liquid contained F ~ F / f; 1 2 U
within the chamber 332, again the piston is moved forward towards -the needle 313. The pressure in the liquid then deflects the Flanges 319 away from the surfac~ 317 so that the liquid can then reach the needles 313.
Re-use of the syringe is inhibited since once the syringe has been used7 the surface 326 is located forward of the surfaces 323 of the projections 321. Once this has occurred, the valve member 318 prevents any liquid being drawn irto the chamber 332.
FJF/~l'IJ
Claims (16)
1. A single use syringe comprising:
an inter-acting piston and cylinder defining a variable volume chamber within which a liquid to be injected is drawn;
a needle mounting at one end of said cylinder, to receive a needle, a passage extending through said mounting enabling liquid communication between said cylinder and said needle;
a piston rod attached to said piston and operable by a user to cause movement of said piston to vary the volume of said chamber;
a valve means including a valve body located within said chamber between said mounting and said piston and dividing said chamber into a first sub-chamber located between said mounting and valve means, and a second sub-chamber located between said valve means and said piston, said valve body being movable longitudinally of said cylinder between a first position and a second position, and said valve means includes a first valve which, when said body is in said first position, permits flow from said first sub chamber to said second sub-chamber and prevents flow from said second sub-chamber to said first sub-chamber, but when said body is in said second position, said first valve permits flow from said second sub-chamber to said first sub-chamber, and a second valve which, when said body is in said first position, permits flow from said first sub-chamber to said second sub-chamber, but prevents flow from said first sub-chamber to said second sub-chamber when said body is in said second position; and means to prevent movement of said body from said second position to said first position.
an inter-acting piston and cylinder defining a variable volume chamber within which a liquid to be injected is drawn;
a needle mounting at one end of said cylinder, to receive a needle, a passage extending through said mounting enabling liquid communication between said cylinder and said needle;
a piston rod attached to said piston and operable by a user to cause movement of said piston to vary the volume of said chamber;
a valve means including a valve body located within said chamber between said mounting and said piston and dividing said chamber into a first sub-chamber located between said mounting and valve means, and a second sub-chamber located between said valve means and said piston, said valve body being movable longitudinally of said cylinder between a first position and a second position, and said valve means includes a first valve which, when said body is in said first position, permits flow from said first sub chamber to said second sub-chamber and prevents flow from said second sub-chamber to said first sub-chamber, but when said body is in said second position, said first valve permits flow from said second sub-chamber to said first sub-chamber, and a second valve which, when said body is in said first position, permits flow from said first sub-chamber to said second sub-chamber, but prevents flow from said first sub-chamber to said second sub-chamber when said body is in said second position; and means to prevent movement of said body from said second position to said first position.
2. The syringe of Claim 1, wherein said second position of said body is closer to said mounting than the second position of said body.
3. The syringe of Claim 1 or 2 wherein said first and second valves include valve flaps attached to said body, and said cylinder has recesses selectively sealingly cooperating with said valve flaps.
4. The syringe of Claim 2 further including first projection means to engage the valve flap of said first valve, which first projection means is positioned to deflect said valve flap from sealing engagement with said cylinder when said body is in said second position, and second projection means to engage the valve flap of said second valve means to move it from sealing contact with said cylinder when said body is in said first position.
5. The syringe of Claim 1 or 2 wherein said valve body is formed of resilient material, and said valves include resilient circular flanges on said body, and a first projection means on said cylinder and positioned to engage the flange of the first valve when said body is in said second position, and second projection means which engages the flange of said second valve when said body is in said first position.
6. A valve assembly for a syringe having an interacting piston and cylinder, with the cylinder terminating at one end with a mounting to receive a syringe needle, said piston and cylinder co-operating to define a variable volume working chamber which receives a liquid to be injected by the syringe, said valve assembly being adapted to be located within said chamber so as to divide said chamber into a first sub-chamber located adjacent the needle mounting, and a second sub-chamber located adjacent the piston, said valve assembly including;
a valve sleeve to be sealingly received within said cylinder so as to be coaxial with respect thereto, said sleeve having an internal peripheral surface;
a movable valve member received within said sleeve and sealingly co-operating therewith so that in use of the syringe the valve member selectively controls the direction of flow of liquid within the syringe, said valve member having a pair of axially spaced annular sealing surfaces which sealingly engage said sleeve, and which are resiliently deformable;
a first set of sleeve projections extending inwardly of said sleeve to engage a first one of said sealing surfaces;
a second set of sleeve projections extending inwardly of said sleeve to engage the other sealing surface, said second set of sleeve projections being spaced longitudinally of said first set of sleeve projections; and wherein said valve member is longitudinally movable between a first portion wherein the first annular sealing surface is engaged with the first set of sleeve projections so as to be deformed and deflected from said sleeve so that liquid may pass thereby, and the other sealing surface is in sealing contact with said sleeve and inhibits the direction of fluid flow in a first direction, and a second position wherein said second sealing surface is engaged with said second set of sleeve projections so that liquid may pass thereby, and said first sealing surface is sealingly engaged with said sleeve to inhibit fluid flow in a second direction, which is opposite to said first direction.
a valve sleeve to be sealingly received within said cylinder so as to be coaxial with respect thereto, said sleeve having an internal peripheral surface;
a movable valve member received within said sleeve and sealingly co-operating therewith so that in use of the syringe the valve member selectively controls the direction of flow of liquid within the syringe, said valve member having a pair of axially spaced annular sealing surfaces which sealingly engage said sleeve, and which are resiliently deformable;
a first set of sleeve projections extending inwardly of said sleeve to engage a first one of said sealing surfaces;
a second set of sleeve projections extending inwardly of said sleeve to engage the other sealing surface, said second set of sleeve projections being spaced longitudinally of said first set of sleeve projections; and wherein said valve member is longitudinally movable between a first portion wherein the first annular sealing surface is engaged with the first set of sleeve projections so as to be deformed and deflected from said sleeve so that liquid may pass thereby, and the other sealing surface is in sealing contact with said sleeve and inhibits the direction of fluid flow in a first direction, and a second position wherein said second sealing surface is engaged with said second set of sleeve projections so that liquid may pass thereby, and said first sealing surface is sealingly engaged with said sleeve to inhibit fluid flow in a second direction, which is opposite to said first direction.
7. A single use syringe having an interacting piston and cylinder, with the cylinder terminating at one end with a mounting to receive a syringe needle, said piston and cylinder cooperating to define a variable volume working chamber which receives a liquid to be injected by the syringe, and the valve assembly of Claim 6, which valve assembly is located within said chamber so as to divide said chamber into said first sub-chamber and said second sub-chamber.
8. A valve for a single use syringe having an interacting piston and cylinder and a syringe needle, said valve comprising:
duct means providing a passage through which liquid to be injected must pass to be delivered to said needle;
a movable valve body located in said duct means and dividing said passage into a first sub-chamber and a second sub-chamber, with said first sub-chamber to be located closer to said needle than said second sub-chamber, said valve body being movable longitudinally of said duct means between a first position and a second position under the influence of pressure applied thereto by said liquid; and wherein said valve body includes a first valve means sealingly co-operating with said duct means and which, when said body is in said first position, permits flow from said first sub-chamber to said second sub-chamber and prevents flow from said second sub-chamber to said first sub-chamber, but when said body is in said second position, said first valve means permits flow from said second sub-chamber to said first sub-chamber, and a second valve means which, when said body is in said first position, permits flow from said first sub chamber to said second sub-chamber but prevents flow from said first sub-chamber to said second sub-chamber when said body is in said second position; and means to prevent movement of said body from said second position to said first position.
duct means providing a passage through which liquid to be injected must pass to be delivered to said needle;
a movable valve body located in said duct means and dividing said passage into a first sub-chamber and a second sub-chamber, with said first sub-chamber to be located closer to said needle than said second sub-chamber, said valve body being movable longitudinally of said duct means between a first position and a second position under the influence of pressure applied thereto by said liquid; and wherein said valve body includes a first valve means sealingly co-operating with said duct means and which, when said body is in said first position, permits flow from said first sub-chamber to said second sub-chamber and prevents flow from said second sub-chamber to said first sub-chamber, but when said body is in said second position, said first valve means permits flow from said second sub-chamber to said first sub-chamber, and a second valve means which, when said body is in said first position, permits flow from said first sub chamber to said second sub-chamber but prevents flow from said first sub-chamber to said second sub-chamber when said body is in said second position; and means to prevent movement of said body from said second position to said first position.
9. The valve of Claim 8, wherein said second position of said body is intended to be closer to said needle than said first position of said body.
10. The valve of Claim 8 or 9, wherein said first and second valve means include valve flaps attached to a central portion of said body, and said duct means has recesses selectively sealingly co-operating with said valve flaps.
11. The valve of Claim 9, wherein said valve body is formed of resilient material, and each valve means includes a resilient circular flange, and said valve means further includes projection means on the internal peripheral surface of said sleeve positioned to engage the first valve means when said body is in said second position, and to engage the second valve means when said body is in said first position.
12. The valve of Claim 11, wherein said projection means includes first projection means to engage said first valve means, which first projection means is positioned to deflect said first valve means from sealing engagement with said duct means when said body is in said second position, and second projection means to engage the second valve means to move it from sealing contact with said duct means when said body is in said first position.
13. The valve of Claim 9 wherein said piston and cylinder provide a primary chamber, said valve is adapted to be located within said primary chamber so as to divide said primary chamber into said first sub-chamber located adjacent the needle mounting, and said second sub-chamber located adjacent the piston, and said valve is sealingly received within said cylinder so as to be coaxial with respect thereto.
14. A single use syringe comprising:
an inter-acting piston and cylinder defining a variable volume primary chamber within which a liquid to be injected is drawn;
a needle mounting at one end of said cylinder, to receive a needle, a passage extending through said mounting enabling liquid communication between said cylinder and said needle;
a piston rod attached to said piston and operable by a user to cause movement of said piston to vary the volume of said chamber; and a valve according to Claim 9 through which said liquid must pass in flowing between said needle and said primary chamber.
an inter-acting piston and cylinder defining a variable volume primary chamber within which a liquid to be injected is drawn;
a needle mounting at one end of said cylinder, to receive a needle, a passage extending through said mounting enabling liquid communication between said cylinder and said needle;
a piston rod attached to said piston and operable by a user to cause movement of said piston to vary the volume of said chamber; and a valve according to Claim 9 through which said liquid must pass in flowing between said needle and said primary chamber.
15. The syringe of Claim 14, wherein said valve body is located within said primary chamber between said mounting and said piston, and said cylinder provides and passage.
16. The syringe of Claim 14, wherein said valve is located in said needle mounting.
Applications Claiming Priority (4)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AUPI9554 | 1988-07-29 | ||
| AUPI955488 | 1988-07-29 | ||
| AUPJ037688 | 1988-09-13 | ||
| AUPJ0376 | 1988-09-13 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1317177C true CA1317177C (en) | 1993-05-04 |
Family
ID=25643515
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000606993A Expired - Fee Related CA1317177C (en) | 1988-07-29 | 1989-07-28 | Single use syringe |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA1317177C (en) |
| NZ (1) | NZ230113A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109571876A (en) * | 2019-01-25 | 2019-04-05 | 阳江恒茂包装制品有限公司 | A kind of injection hanging ring integral type injection mold |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111671987B (en) * | 2020-07-10 | 2024-10-01 | 北京大学深圳医院 | Negative pressure injector |
-
1989
- 1989-07-27 NZ NZ23011389A patent/NZ230113A/en unknown
- 1989-07-28 CA CA000606993A patent/CA1317177C/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109571876A (en) * | 2019-01-25 | 2019-04-05 | 阳江恒茂包装制品有限公司 | A kind of injection hanging ring integral type injection mold |
| CN109571876B (en) * | 2019-01-25 | 2024-02-20 | 阳江恒茂包装制品有限公司 | Injection rings integral type injection mold |
Also Published As
| Publication number | Publication date |
|---|---|
| NZ230113A (en) | 1992-07-28 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKLA | Lapsed |