CN111388806B - A set-volume syringe - Google Patents

Abstract

The invention provides a set quantity type injector which comprises a needle cylinder, a push rod and a limiting baffle piece, wherein the limiting baffle piece is fixed relative to the axial position of the needle cylinder, at least part of the limiting baffle piece is projected to the inner side of the needle cylinder along the axial direction of the needle cylinder, the push rod can rotate relative to the limiting baffle piece around the axial direction of the needle cylinder and is pushed into the inner side of the needle cylinder along the axial direction, at least one quantitative piece is axially distributed on the push rod, and the push rod drives each quantitative piece to pass through a blocking position and a passing position in the rotating process relative to the limiting baffle piece; when the quantitative part rotates to the blocking position, a cross part exists between the quantitative part and the limiting baffle part along the projection of the axial direction of the needle cylinder and positioned on the inner side of the needle cylinder; when the quantitative part rotates to the passing position, the projection of the quantitative part and the limiting baffle part along the axial direction of the needle cylinder is separated from each other; when a plurality of quantitative parts are arranged in the axial direction of the push rod, the blocking positions corresponding to every two adjacent quantitative parts in the axial direction are different by a preset angle in the rotation range of the push rod. The syringe can conveniently realize quantitative injection for a plurality of times.

Description

A set-volume syringe

Technical Field

The invention relates to the technical field of medical devices, and in particular to a set-volume syringe.

Background Art

The technology in the field of syringes represented by conventional syringes, pre-filled pre-sealed syringes, and filled drug syringes is developing faster and faster, and the scope of clinical application is also becoming wider and wider. At present, during the injection process of syringe products used in clinical practice, it is often necessary to inject the liquid medicine in the syringe in multiple times.

When the injection is finished, the force exerted by the push rod on the piston causes the top of the piston to deform and penetrate into the hollow channel of the cone head of the syringe. When the external force is removed and the piston head is deformed and restored, the liquid in the locked cone head will be drawn back, resulting in blood return.

Existing syringes require the operator to control the injection volume according to the scale on the syringe, and need to clamp the syringe with fingers and push it with great force. The operator needs to pay attention to the scale, clamping force and injection angle depth at the same time, which makes it easy for the injection volume to be too large or too small, resulting in overtreatment or undertreatment.

Therefore, how to conveniently achieve quantitative injection of a syringe is a technical problem that those skilled in the art currently need to solve.

Summary of the invention

In view of this, an object of the present invention is to provide a set-volume syringe, which can conveniently implement multiple quantitative injections.

In order to achieve the above object, the present invention provides the following technical solutions:

A set-volume syringe comprises a syringe and a push rod, and further comprises a limit stopper, wherein the limit stopper is fixed relative to the axial position of the syringe, and at least a portion of the projection of the limit stopper along the axial direction of the syringe is located inside the syringe, the push rod can rotate relative to the limit stopper around the axial direction of the syringe and be pushed into the inside of the syringe along the axial direction, at least one quantitative component is distributed on the push rod along the axial direction, and the push rod drives each of the quantitative components to pass through a blocking position and a passing position during the rotation process relative to the limit stopper;

When the quantitative member follows the push rod and rotates relative to the limit stopper to the blocking position, there is an intersection between the projections of the quantitative member and the limit stopper along the axial direction of the syringe and located on the inner side of the syringe;

When the quantitative member follows the push rod and rotates relative to the limit stopper to a passing position, the projections of the quantitative member and the limit stopper along the axial direction of the syringe are separated from each other;

When a plurality of quantitative members are arranged in the axial direction of the push rod, the blocking positions corresponding to every two adjacent quantitative members in the axial direction differ by a preset angle within the rotation range of the push rod.

Preferably, when a plurality of the quantitative members are arranged on the push rod, the distance between every two adjacent quantitative members in the axial direction is in a linear relationship with the corresponding preset injection volume.

Preferably, the above-mentioned set-volume syringe also includes a handle limit assembly, which includes a handle connecting mechanism and a limit stopper connecting mechanism, and the handle limit assembly is detachably connected to the handle at the end of the syringe through the handle connecting mechanism, and the limit stopper is connected to the limit stopper connecting mechanism.

Preferably, the limit stopper connection mechanism includes a fixed plate, the fixed plate is provided with a limit opening corresponding to the terminal barrel of the syringe, the limit stopper is fixedly connected to the inner side of the limit opening, the handle connection mechanism includes a clamping plate arranged opposite to the fixed plate, the clamping plate is connected and fixed to the fixed plate through an intermediate connecting piece and a clamping gap is reserved between the clamping plate and the fixed plate, the clamping plate is provided with a clamping port arranged opposite to the limit opening, and the side of the clamping plate is provided with an open clamping groove connected to the clamping port.

Preferably, the limit stopper connection mechanism comprises a fixing plate, a limit stopper fixing ring and a support cylinder with openings at both ends, the fixing plate is provided with a limit opening corresponding to the end barrel opening of the syringe, the support cylinder is fixed to one side of the fixing plate and the barrel opening of the support cylinder is arranged opposite to the limit opening, the support cylinder is sleeved on the outer periphery of the push rod, the limit stopper is fixedly connected to the inner wall of the support cylinder for rotation around the axis of the support cylinder, the side wall of the support cylinder is provided with a limit notch extending in the circumferential direction, the limit stopper fixing ring is fixed with a lever penetrating the limit notch and extending out of the outer side of the support cylinder, and the limit stopper is fixedly connected to the inner side of the limit stopper fixing ring;

The handle connection mechanism includes a snap-in plate arranged opposite to the fixed plate, the snap-in plate is connected and fixed to the fixed plate via an intermediate connecting piece and a snap-in gap is reserved between the snap-in plate and the fixed plate, the snap-in plate is provided with a snap-in opening arranged opposite to the limiting opening, and the side of the snap-in plate is provided with an open snap-in slot connected to the snap-in opening.

Preferably, the inner wall of the support tube is provided with an annular guide rail surrounding in the circumferential direction, and the outer periphery of the position limit stopper fixing ring is provided with an annular groove cooperating with the annular guide rail.

Preferably, the outer periphery of the limit stopper fixing ring includes a first retaining ring located at the upper end of the annular retaining groove and a second retaining ring located at the lower end of the annular retaining groove, the shift rod is fixed to the outer side of the first retaining ring, the limit stopper is fixedly connected to the inner side of the first retaining ring, the second retaining ring is circumferentially distributed with at least one retaining notch, and the second retaining ring is an elastic retaining ring structure that can be elastically deformed along its own radial direction.

Preferably, the limit stopper comprises a first stopper and a second stopper which are arranged opposite to each other, and the first stopper and the second stopper are clamped on both sides of the outer periphery of the push rod.

Preferably, the main body of the push rod includes a plurality of long strip ribs, the length directions of the plurality of ribs are extended along the length direction of the push rod, and the plurality of ribs are radially arranged around the axis of the push rod, and each of the quantitative parts is connected between two adjacent ribs.

Preferably, a plurality of saw teeth for clamping the rib plate are provided on opposite sides of the first stopper and the second stopper.

Preferably, the first stopper and the second stopper are symmetrically distributed with respect to the radial direction of the push rod, and the sawtooth is a bidirectional through sawtooth;

Alternatively, the first stopper and the second stopper are centrally symmetrically distributed relative to the center of the push rod, and the sawtooth is a one-way through sawtooth.

Preferably, each of the quantitative components includes a pair of quantitative baffles, and the pair of quantitative baffles are centrally symmetrically distributed relative to the axis of the push rod.

Preferably, the end of the push rod located on the inner side of the syringe is the push rod head, and the end of the push rod extending outside the syringe is the push rod tail. The push rod is provided with a stopper for limiting engagement with the limit stopper, and the stopper is located between the quantitative member and the push rod tail. The distance between the stopper and the quantitative member closest to the push rod head is less than or equal to the injection distance corresponding to the maximum injection volume of the syringe.

Preferably, the quantitative member is detachably connected to the push rod.

Preferably, a plurality of slots are axially provided on the push rod, and the quantitative member is detachably inserted into the slots.

Preferably, scale lines are arranged on the push rod along the axial direction.

The method for using the set-volume syringe provided by the present invention is as follows:

On the premise that the syringe contains liquid medicine, the air is exhausted before injection, the head of the syringe is facing upward, the push rod is pushed and the gas in the syringe is exhausted. After the exhaust is completed, the quantitative part closest to the push rod head is stuck at the outer end of the limit stopper. Then the quantitative injection is performed, and the push rod is rotated relative to the limit stopper by a preset angle. At this time, the quantitative part closest to the push rod head is rotated to the passing position, and the quantitative part is separated from the limit stopper, so that the push rod can continue to be pushed into the inner side of the syringe for injection until the quantitative injection is completed. When multiple quantitative injections are required, the multiple quantitative parts axially arranged on the push rod are rotated in sequence by preset angles, and at the same time, they are pushed forward in batches with the push rod. The positioning function of each quantitative injection is realized by the quantitative part and the limit stopper being engaged and limited, until all quantitative injections are completed, and the piston at the head of the push rod reaches the head position of the syringe.

The present invention has the following beneficial effects:

1) This scheme sets the dosage of the segmented injection of the drug solution, and the injection stops automatically after the set dosage is reached, thus avoiding the situation where the injection volume is too large or too small, and ensuring the accuracy of quantitative injection;

2) This solution requires that before each quantitative injection, the push rod must be rotated to a preset angle before the quantitative component can be rotated to the passing position to ensure that the push rod can continue to be pushed into the syringe, prevent misoperation, and improve the safety of segmented injection;

3) During the injection process, this solution allows medical staff to focus on the injection force and injection speed, thus improving the injection quality;

4) In the preferred embodiment, by providing a handle stop assembly detachably connected to the handle at the end of the syringe, the ordinary syringe can be easily modified to have the function of segmented quantitative injection, thereby improving the application scope of the product;

5) In the preferred embodiment, a stop piece is provided on the push rod to ensure that after the injection is completed, the stop piece is engaged with the limit stop piece to prevent the push rod from continuing to be pushed into the syringe, thereby preventing the piston from deforming after squeezing the syringe head and entering the hollow channel in the middle of the cone head, thereby preventing the negative pressure in the hollow channel from causing blood return when the piston is deformed and restored, thereby improving the safety of injection.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

FIG1 is a schematic diagram of the internal structure of a set-volume syringe in a specific embodiment of the present invention;

FIG2 is a schematic diagram of the structure of a push rod in a specific embodiment of the present invention;

FIG3 is a schematic cross-sectional view of a portion A of the push rod in FIG2 ;

FIG4 is a schematic diagram of the structure of a handle limit assembly in a specific embodiment of the present invention;

FIG5 is a schematic diagram of symmetrical distribution of the limit stoppers in the limit opening in a specific embodiment of the present invention;

FIG6 is a schematic diagram of the central symmetrical distribution of the limit stoppers in the limit opening in a specific embodiment of the present invention;

FIG7 is a schematic diagram of a first viewing angle of a set metering syringe in a specific embodiment of the present invention;

FIG8 is a second perspective schematic diagram of the entire set metering syringe in a specific embodiment of the present invention;

FIG9 is a schematic structural diagram of a second handle limit assembly in a specific embodiment of the present invention;

10 is a schematic diagram of the connection structure between the support tube and the fixing plate in a specific embodiment of the present invention;

FIG11 is a front view of the connection structure between the support tube and the handle connection mechanism in a specific embodiment of the present invention;

Fig. 12 is a cross-sectional view of the structure in Fig. 11 along the line A-A;

FIG13 is a schematic diagram of the overall structure of a stopper fixing ring in a specific embodiment of the present invention;

FIG14 is a top view of a stopper fixing ring in a specific embodiment of the present invention;

FIG15 is a schematic diagram of the overall structure of the stopper fixing ring in a specific embodiment of the present invention from another perspective;

FIG16 is a schematic diagram of a second handle limit assembly in a specific embodiment of the present invention working in a blocking position;

FIG. 17 is a schematic diagram of the second handle limit assembly in a specific embodiment of the present invention working in the passing position.

The meanings of the reference numerals in FIGS. 1 to 17 are as follows:

1-syringe, 2-piston, 3-push rod, 4-handle limiting assembly, 5-limit stopper, 11-handle, 31-quantitative member, 311-quantitative baffle, 32-termination member, 33-push handle, 34-locking head, 35-rib plate, 41-fixed plate, 42-clamping plate, 43-rib, 44-side connecting plate, 45-clamping gap, 411-limiting opening, 421-bayonet, 422-card groove, 51-first stopper, 52-second stopper, 6-limit stopper fixing ring, 61-dial rod, 62-first clamping ring, 63-annular clamping groove, 64-second clamping ring, 65-clamping notch, 66-chamfer, 7-support cylinder, 71-limiting notch, 72-annular guide rail.

DETAILED DESCRIPTION

The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

Please refer to Figures 1 to 8, Figure 1 is a schematic diagram of the internal structure of a set-volume syringe in a specific embodiment of the present invention; Figure 2 is a schematic diagram of the structure of a push rod in a specific embodiment of the present invention; Figure 3 is a schematic diagram of the cross-section of part A of the push rod in Figure 2; Figure 4 is a schematic diagram of the structure of a handle limit assembly in a specific embodiment of the present invention; Figures 5 and 6 are schematic diagrams of the symmetrical distribution and center-symmetrical distribution of the limit stops in a specific embodiment of the present invention, respectively; Figures 7 and 8 are schematic diagrams of the first and second viewing angles of the entire set-volume syringe in a specific embodiment of the present invention, respectively.

The present invention provides a set-volume syringe, comprising a syringe 1, a push rod 3, and a limit stopper 5. The end of the push rod 3 located inside the syringe 1 is the push rod head, the end of the push rod 3 extending outside the syringe 1 is the push rod tail, the limit stopper 5 is fixed relative to the axial position of the syringe 1, and at least part of the projection of the limit stopper 5 along the axial direction of the syringe 1 is located inside the syringe 1, the push rod 3 can rotate relative to the limit stopper 5 around the axial direction of the syringe 1 and be pushed into the inside of the syringe 1 along the axial direction, at least one quantitative component 31 is distributed on the push rod 3 along the axial direction, and the push rod 3 drives each quantitative component 31 to pass through the blocking position and the passing position during the rotation process relative to the limit stopper 5;

When the quantitative member 31 follows the push rod 3 and rotates relative to the limit stopper 5 to the blocking position, there is an intersection between the quantitative member 31 and the limit stopper 5 along the axial direction of the syringe 1 and the projection located on the inner side of the syringe 1;

When the quantitative member 31 follows the push rod 3 and rotates relative to the limit stopper 5 to the passing position, the quantitative member 31 and the limit stopper 5 are separated from each other in the axial direction of the syringe 1;

When a plurality of quantitative members 31 are arranged axially of the push rod 3 , the blocking positions corresponding to every two adjacent quantitative members 31 in the axial direction differ by a preset angle within the rotation range of the push rod 3 .

In addition, the above-mentioned syringe also includes a piston 2 located inside the syringe 1, the piston 2 is connected to the push rod head of the push rod 3, and the push rod head is provided with a locking head 34 that cooperates with the piston 2 and is fixed. The locking head 34 can be designed as a spiral structure or a snap-fit structure, etc. A push handle 33 is provided at the rear of the push rod, which is convenient for medical staff to apply thrust to the push rod 3 with their fingers.

Preferably, the end of the push rod 3 located on the inner side of the syringe 1 is the push rod head, and the end of the push rod 3 extending out of the syringe 1 is the push rod tail. The push rod 3 is also provided with a stopper 32 for limiting engagement with the limit stopper 5. The stopper 32 is located between the metering member 31 and the push rod tail, that is, the stopper 32 is closer to the push rod tail than any metering member 31, and there is a certain distance between the stopper 32 and the metering member 31 closest to the push rod tail, and the distance between the stopper 32 and the metering member 31 closest to the push rod head is less than or equal to the injection distance corresponding to the maximum injection volume of the syringe. The purpose of such design is that when the injection is completed, the piston 2 has been in contact with the head of the syringe 1 or has not yet been in contact. At this time, the stop member 32 is engaged with the limit stopper 5 to stop the push rod 3 from continuing to push into the syringe 1, thereby preventing the piston 2 from further squeezing the syringe head and deforming and entering the hollow channel in the middle of the cone head, thereby preventing the negative pressure in the hollow channel from causing blood return when the piston 2 is deformed and restored, thereby improving the safety of injection.

In addition, the above-mentioned end member 32 can be designed as a circular plate structure, annular plate structure or circular retaining ring structure arranged circumferentially around the push rod 3. No matter what angle the push rod 3 rotates to, the end member 32 can be engaged with the limit stopper 5 to limit the position, thereby ensuring that the push rod 3 stops advancing in time.

The method for using the set-volume syringe provided by the present invention is as follows:

On the premise that the syringe 1 contains liquid medicine, the air is exhausted before injection, the head of the syringe 1 is facing upward, the push rod 3 is pushed to exhaust the gas in the syringe 1, and after the exhaust is completed, the quantitative member 31 closest to the push rod head is stuck at the outer end of the limit stopper 5. Then, quantitative injection is performed, and the push rod 3 is rotated relative to the limit stopper 5 by a preset angle. At this time, the quantitative member 31 closest to the push rod head rotates to the passing position, and the quantitative member 31 is separated from the limit stopper 5, so that the push rod 3 can continue to be pushed into the inner side of the syringe 1 for injection until the quantitative injection is completed. When multiple quantitative injections are required, the multiple quantitative parts 31 axially arranged on the push rod 3 are rotated in sequence at a preset angle, and at the same time, the push rod 3 is advanced in batches. The positioning function of each quantitative injection is realized by the limited engagement of the quantitative parts 31 and the limit stopper 5. After all the quantitative injections are completed, the piston 2 at the head of the push rod reaches the head position of the syringe 1, and the end part 32 is stuck at the outer end of the limit stopper 5. The push rod 3 cannot continue to advance, thereby preventing the piston 2 and the head of the syringe 1 from being squeezed and deformed to produce blood return.

It should be noted that the rotation axis of the push rod 3 in the syringe 1 can be the axis of the syringe 1, the axis of the push rod 3, or an axis parallel to the axis of the syringe. The push rod 3 can be arranged coaxially with the syringe 1, or can be arranged non-coaxially and the axes of both are parallel. When the push rod 3 rotates in the syringe 1, it will drive the quantitative member 31 on the push rod 3 to rotate together. The rotation range of the push rod 3 is within the angle range of 0° to 360°. Each quantitative member 31 has a blocking position and a passing position within the rotation range. The blocking position and the passing position correspond to a certain angle range, that is, the quantitative member 31 needs to rotate a certain angle with the push rod 3 to switch between the blocking position and the passing position.

It should be noted that, in this solution, only one quantitative component 31 may be provided on the push rod 3. In this case, the quantitative component 31 may be used to assist in the exhaust operation before injection and the positioning of the one-time quantitative injection. The specific usage process is as follows: before starting the quantitative injection, the syringe 1 is filled with liquid medicine, and a certain amount of gas may still remain in the syringe 1. At this time, the quantitative component 31 is located outside the syringe 1 and is at a certain distance from the limit stopper 5. Then, the head of the syringe 1 is arranged upward, the quantitative component 31 is rotated to the blocking position, and then the push rod 3 is pushed. When the quantitative component 31 abuts against the outer end of the limit stopper 5, the exhaust operation before injection is completed; then, the push rod 3 is rotated by a certain angle and the quantitative component 31 is rotated to the passing position, so that the quantitative component 31 is disengaged from the limit stopper 5. At this time, the push rod 3 can continue to be pushed for quantitative injection until the injection is completed. When the injection is completed, the piston 2 at the head of the push rod is squeezed on the head of the syringe 1, and the stopper 32 is stuck on the outer end of the limit stopper 5. Naturally, the push rod 3 cannot continue to be pushed forward, thereby preventing the piston 2 and the head of the syringe 1 from being squeezed and deformed to produce blood return.

In order to realize multiple segmented quantitative injections of the syringe, the present solution preferably arranges multiple quantitative members 31 along the axial direction on the push rod 3. When multiple quantitative members 31 are arranged on the push rod 3, the distance between each two adjacent quantitative members 31 along the axial direction is linearly related to the corresponding preset injection volume. The following is explained by way of example: for a 6ml syringe, the inner wall cross-sectional area of the syringe barrel 1 is ^1cm2 . If three quantitative injections are to be realized, and the first injection volume is 1ml, the second injection volume is 2ml, and the third injection volume is 3ml, then at least three quantitative members 31 need to be arranged. The three quantitative members 31 are arranged in sequence from the push rod head to the push rod tail. The first quantitative member and the second quantitative member are 1cm apart, the second quantitative member and the third quantitative member are 2cm apart, and the third quantitative member and the fourth quantitative member are 3cm apart, or the push rod portion between the third quantitative member and the push rod tail is no longer provided with a quantitative member and the distance between the third quantitative member and the push rod tail is greater than 3cm, so as to ensure that the third quantitative injection can achieve an injection volume of 3ml. It can be seen from the above example that the linear relationship between the distance x between every two adjacent metering members 31 in the axial direction and the corresponding preset injection volume c is: c=S·x, wherein S is the internal cross-sectional area of the syringe.

It should be noted that the main function of the limit stopper 5 in this solution is to serve as a limit structure to limit the push rod 3 from continuing to advance at the end of each quantitative injection. The limit stopper 5 is fixed in the axial position relative to the syringe 1, so it can ensure that an accurate positioning reference is provided for the push rod 3. In this solution, the limit stopper 5 can be fixedly set on the inner ring of the tail opening of the syringe 1 or the inner wall of the syringe 1, and the detachable connection between the limit stopper 5 and the syringe 1 can also be achieved through other connection structures. In a preferred solution, the limit stopper 5 in this solution is connected and fixed to the syringe 1 through a detachable connection structure. Specifically, the above-mentioned set-volume syringe also includes a handle limit assembly 4, and the handle limit assembly 4 includes a handle connection mechanism and a limit stopper connection mechanism. The handle limit assembly 4 is detachably connected to the handle 11 at the end of the syringe 1 through the handle connection mechanism, and the limit stopper is connected to the limit stopper connection mechanism.

It should be noted that the above-mentioned handle connecting mechanism and limit stopper connecting mechanism can have various structural forms, among which the handle connecting mechanism can be detachably installed with the handle 11 through a slot structure, and can also be clamped on the outer wall of the syringe below the handle 11 through a clip mechanism, and can also be detachably connected with the handle 11 through a threaded connection structure, or a snap structure, or an adhesive method; the limit stopper connecting mechanism can be designed as a plate-like structure, a ring-like structure, a rod-like structure, etc., and these structures can all serve as the basis for supporting and fixing the limit stopper 5.

Please refer to Figure 4. In a preferred embodiment, the limit stopper connection mechanism includes a fixed plate 41, the fixed plate 41 is provided with a limit opening 411 corresponding to the end barrel mouth of the syringe 1, the limit stopper 5 is fixedly connected to the inner side of the limit opening 411, and the handle connection mechanism includes a clamping plate 42 arranged opposite to the fixed plate 41, the clamping plate 42 is connected and fixed to the fixed plate 41 through an intermediate connecting member and a clamping gap 45 is reserved between the clamping plate 42 and the fixed plate 41, the clamping plate 42 is provided with a clamping port 421 arranged opposite to the limit opening 411, and the side of the clamping plate 42 is provided with an open clamping groove 422 connected to the clamping port 421. When installing the handle limit assembly 4, the handle 11 at the end of the syringe 1 is inserted from the position of the card slot 422 on the side of the above-mentioned card plate 42 into the card gap 45 formed by the fixed plate 41 and the card plate 42, until the end of the syringe 1 corresponds to the axial position of the limit opening 411 of the fixed plate 41. At this time, the outer wall of the syringe 1 below the handle 11 is stuck in the card slot 421 of the card plate 42, and the handle 11 is firmly clamped between the fixed plate 41 and the card plate 42. In this scheme, the intermediate connecting member used to connect the fixed plate 41 and the card plate 42 can be used, but not limited to, connecting members such as bolts, buckles, ribs, etc. Preferably, in this scheme, the two end edges of the fixed plate 41 in the length direction are connected and fixed to the card plate 42 through the side connecting plates 44, wherein the side connecting plates 44 can be designed as an integrated structure with the fixed plate 41 and the card plate 42, which can better ensure the connection firmness. In addition, since the clip-on plate 42 and the fixed plate 41 are arranged relative to each other, in order to ensure the supporting strength between the opposite surfaces of the two plates, the present scheme preferably provides one or more ribs 43 between the fixed plate 41 and the clip-on plate 42, and the upper and lower sides of the ribs 43 are respectively in contact with or directly connected to the opposite surfaces of the fixed plate 41 and the clip-on plate 42, thereby further improving the supporting strength and the overall rigidity of the handle limit assembly 4, as shown in Figure 4.

In the above preferred embodiment, by setting the handle limit assembly 4 and adopting a detachable connection structure, the limit stopper 5 and the syringe 1 can be quickly assembled, so that the ordinary syringe can be easily modified to have the function of segmented quantitative injection, thereby improving the application scope of this product.

Please refer to Figures 9 to 17. In another preferred embodiment, the limit stopper connection mechanism includes a fixing plate 41, a limit stopper fixing ring 6 and a support tube 7 with openings at both ends. The fixing plate 41 is provided with a limit opening 411 corresponding to the end tube mouth of the syringe 1. The support tube 7 is fixed to one side of the fixing plate 41 and the tube mouth of the support tube 7 is arranged opposite to the limit opening 411. The support tube 7 is sleeved on the outer periphery of the push rod 3. The limit stopper fixing ring 6 is rotatably connected to the inner wall of the support tube 7 around the axis of the support tube 7. The side wall of the support tube 7 is provided with a limit opening extending in the circumferential direction. The notch 71, the limit stopper fixing ring 6 is fixed with a lever 61 that passes through the limit notch 71 and extends out of the outside of the support tube 7, and the limit stopper 5 is fixedly connected to the inner side of the limit stopper fixing ring 6; the handle connecting mechanism includes a clamping plate 42 arranged opposite to the fixing plate 41, the clamping plate 42 is connected and fixed to the fixing plate 41 through an intermediate connecting piece and a clamping gap 45 is reserved between the clamping plate 42 and the fixing plate 41, the clamping plate 42 is provided with a clamping port 421 arranged opposite to the limit opening 411, and the side of the clamping plate 42 is provided with an open clamping groove 422 connected to the clamping port 421. In this solution, the limit stopper fixing ring 6 can drive the limit stopper 5 to rotate relative to the support tube 7, and the push rod 3 can be designed not to rotate relative to the syringe 1. When in use, the push rod 3 is pushed to achieve injection. When the quantitative member 31 abuts against the outer end of the limit stopper 5, a quantitative injection is completed. When continuing the second quantitative injection, it is only necessary to manually move the lever 61, so that the limit stopper fixing ring 6 drives the limit stopper 5 to rotate in the support tube 7. When the limit stopper 5 rotates to the passing position, the quantitative member 31 and the limit stopper 5 are separated from the limit. At this time, the push rod 3 can continue to be pushed to achieve the second quantitative injection, and so on to complete the subsequent injection operation. It should be noted that the handle connection mechanism in this preferred embodiment is similar in structure to the handle connection mechanism in the previous embodiment, so it will not be repeated in this article.

It should be noted that the stopper fixing ring 6 in the above embodiment can achieve relative rotation connection with the support tube 7 through various structural forms, such as through an annular guide rail matching structure, or an annular groove for accommodating the stopper fixing ring 6 is designed on the inner wall of the support tube 7, or only by the cylindrical matching surface between the stopper fixing ring 6 and the inner wall of the support tube 7 to achieve relative rotation and by the limit notch 71 structure of the support tube 7 to limit the relative movement of the two in the axial direction, etc. Preferably, the inner wall of the support tube 7 is provided with an annular guide rail 72 surrounding in the circumferential direction, and the outer periphery of the stopper fixing ring 6 is provided with an annular groove 63 matching with the annular guide rail 72. In this way, the annular guide rail 72 and the annular groove 63 are mutually matched in rotation, so that the stopper fixing ring 6 can only rotate along the circumferential direction of the inner wall of the support tube 7, but cannot move axially relative to the support tube 7, which also ensures the accuracy of quantitative injection. At the same time, the limiting notch 71 and the shifting rod 61 are used to limit the circumferential rotation angle of the limiting stopper fixing ring 6, so that it switches back and forth between the passing position and the blocking position.

Preferably, the outer periphery of the limit stopper fixing ring 6 includes a first clamping ring 62 located at the upper end of the annular clamping groove 63 and a second clamping ring 64 located at the lower end of the annular clamping groove 63, the lever 61 is fixed to the outer side of the first clamping ring 62, the limit stopper 5 is fixedly connected to the inner side of the first clamping ring 62, and the second clamping ring 64 is circumferentially distributed with at least one clamping notch 65, and the second clamping ring 64 is an elastic clamping ring structure that can be elastically deformed along its own radial direction. With such arrangement, when the stopper fixing ring 6 and the support tube 7 are assembled, the second snap ring 64 of the stopper fixing ring 6 can be pressed downward into the through opening of the annular guide rail 72 from the upper end of the support tube 7. At this time, since the second snap ring 64 has a plurality of snap notches 65 distributed circumferentially, the second snap ring 64 can reduce its outer diameter radially, so that the second snap ring 64 can be smoothly snapped into the lower part of the annular guide rail 72. After the second snap ring 64 is snapped into the lower part of the annular guide rail 72, the annular guide rail 72 cooperates with the annular snap groove 63 on the outer side of the stopper fixing ring 6, so that the axial position of the stopper fixing ring 6 and the support tube 7 is fixed. It should be noted that in this solution, the snap notch 65 can also be extended to the annular snap groove 63, so that the second snap ring 64 can be more easily reduced in outer diameter to be snapped into the lower part of the annular guide rail 72.

In order to further facilitate the installation of the limit stop fixing ring 6 and the support tube 7, the present solution is designed with a chamfer 66 on the outer edge of the lower end of the second retaining ring 64, as shown in Figure 15. With such a configuration, when the second retaining ring 64 is pressed in, the chamfer 66 can be used to achieve the purpose of automatic alignment of the second retaining ring 64 and the annular guide rail 72, and the inclined surface of the chamfer 66 can be used to smoothly shrink the outer diameter of the second retaining ring 64.

It should be noted that the limit stopper 5 can have a variety of structural forms, such as a rod-shaped structure, a plate-shaped structure, a raised block structure, etc., all of which can achieve a limit blocking effect on the quantitative member 31 on the push rod 1 along the axial direction of the syringe. In addition, the number of the limit stopper 5 can be one or more, and can be arranged or arranged in a variety of ways. In order to further improve the reliability of the limit stopper 5, preferably, the limit stopper 5 includes a first stopper 51 and a second stopper 52 arranged relatively, and the first stopper 51 and the second stopper 52 are clamped on both sides of the outer periphery of the push rod 3. Specifically, please refer to Figures 5 and 6, the first stopper 51 and the second stopper 52 are both designed as a rod-shaped structure, and one end of the rod-shaped structure is fixed to the inner wall of the limit opening 411, and the other end extends to the inner side of the limit opening 411, and a space for clamping the push rod 3 is formed between the two stops. In this preferred embodiment, the limit stopper 5 is divided into two parts, and the two stops are clamped on both sides of the outer periphery of the push rod 3, so that lateral pressure can be applied to the push rod 3. In this way, when the push rod 3 is pushed into the syringe 1, this pressure can prevent the push rod 3 from rotating at will, thereby ensuring the stability of the push rod 3 in pushing.

It should be noted that the push rod 3 in this solution can be designed into a variety of structural forms, such as a round rod, a square rod, a cross-ribbed rod, etc. Preferably, the main body of the push rod 3 includes a plurality of long strip ribs 35, the length directions of the plurality of ribs 35 are all arranged along the length direction of the push rod 3, and the plurality of ribs 35 are arranged radially around the axis of the push rod 3, and each quantitative member 31 is connected between two adjacent ribs 35. Specifically, in this solution, four ribs 35 are used to form a push rod 3 in a cross-ribbed shape, and this structure can further improve the strength and rigidity of the push rod 3, as shown in Figures 2 and 3. In addition, the push rod 3 is designed as a rod-shaped structure composed of ribs, which makes it more convenient for the first stopper 51 and the second stopper 52 to clamp the push rod 3.

Further preferably, a plurality of saw teeth for clamping the rib plate 35 are provided on opposite sides of the first stopper 51 and the second stopper 52. The first stopper 51 and the second stopper 52 are clamped on the outer side of the rib plate 35 of the push rod 3 by the saw teeth, and the saw teeth can further improve the firmness of the clamping, thereby better preventing the push rod 3 from rotating at will.

It should be noted that the tooth shape of the sawtooth can be a one-way passing sawtooth or a two-way passing sawtooth. When the sawtooth is a one-way passing sawtooth, the push rod 3 can only rotate in one direction under the clamping of the first stopper 51 and the second stopper 52. The one-way passing sawtooth means that the front and rear inclined surfaces of the sawtooth are inclined in one direction, and the edge of the rib plate 35 can only pass in one direction when sliding over the inclined surface of the sawtooth, and when sliding in the reverse direction, it will be stuck in the slot formed by the inclined surface of the sawtooth and cannot continue to slide; the two-way passing sawtooth means that the front and rear inclined surfaces of the sawtooth are inclined in opposite directions, and the edge of the rib plate 35 can slide over the inclined surface of the sawtooth in both the forward and reverse directions.

In a preferred embodiment, as shown in FIG5 , the first stopper 51 and the second stopper 52 are symmetrically distributed with respect to the radial direction of the limiting opening 411, that is, the first stopper 51 and the second stopper 52 are symmetrically distributed with respect to the radial direction of the push rod 3, and the saw teeth are bidirectional through saw teeth. At this time, the push rod 3 can rotate relative to the syringe 1 in both clockwise and counterclockwise directions.

In another preferred embodiment, as shown in FIG6 , the first stopper 51 and the second stopper 52 are centrally symmetrically distributed relative to the center of the limit opening 411, that is, the first stopper 51 and the second stopper 52 are centrally symmetrically distributed relative to the center of the push rod 3, and the sawtooth is a one-way through sawtooth. The front and rear inclined surfaces of the sawtooth shown in FIG6 are inclined from the root of the stopper to the end. At this time, the push rod 3 can only rotate relative to the syringe 1 in the clockwise direction in FIG6. Such a setting can not only facilitate the medical staff to simplify the rotation operation, but also can complete multiple quantitative injections in sequence by rotating the push rod 3 in one direction, and at the same time avoid the damage to the limit stopper 5 caused by accidental bending when the push rod 3 is rotated forward and backward, thereby improving the reliability of the limit stopper 5.

It should be noted that the quantitative member 31 in this solution can also be designed into a variety of structural forms, such as a plate-like structure, a rod-like structure, a raised block structure, etc. In a preferred embodiment, as shown in Figures 2 and 3, each quantitative member 31 includes a pair of quantitative baffles 311, and the pair of quantitative baffles 311 are centrally symmetrically distributed relative to the axis of the push rod 3. In this way, when the quantitative member 31 is limitedly engaged with the limit stopper 5, since the first stopper 51 and the second stopper 52 are clamped on both sides of the push rod 3, and the two quantitative baffles 311 are respectively clamped on the outer ends of the baffles, the two baffles can be used to apply an obstruction force to both sides of the push rod 3, thereby avoiding defects such as the push rod tilting or the failure of the baffle caused by the unbalanced force when the push rod 3 is blocked on one side. In addition, depending on the number of ribs 35 of the push rod 3, the rotation angle range corresponding to the blocking position or passing position of the quantitative component 31 in this scheme is also different. For example, the push rod 3 in this scheme is designed as a cross-rib rod-shaped structure with a cross-shaped cross section composed of four ribs 35. At this time, the quantitative component 31 at each position includes two quantitative baffles 311, and the two quantitative baffles 311 are distributed oppositely, then the rotation angle corresponding to the blocking position of the quantitative component 31 is 90°; if the push rod 3 is designed as a rod-shaped structure with a snowflake-shaped cross section uniformly radiated by six ribs 35, at this time, since the range of one rotation of the push rod 3 can be divided into six areas, and the quantitative component 31 at each position includes two quantitative baffles 311 distributed oppositely, then the rotation angle corresponding to the blocking position of the quantitative component 31 is 60°.

Please refer to Figures 2 and 3. The push rod 3 in the present embodiment preferably adopts a cross-ribbed rod structure. When a plurality of quantitative parts 31 are axially distributed on the push rod 3, the projections of every two adjacent quantitative parts 31 along the axial direction of the push rod 3 do not cross each other, that is, two axially adjacent quantitative baffles 311 are alternately distributed at 90° in the circumferential direction of the push rod 3, so that the rotation angle corresponding to the blocking position of each quantitative part 31 is 90°.

In addition, the above-mentioned quantitative baffle 311 can be designed as a variety of structures such as a fan-shaped plate, a rectangular plate, a circular plate or an arc plate. The present scheme preferably adopts a fan-shaped plate structure, as shown in Figure 3. At this time, the outer edge of the quantitative baffle 311 is an arc-shaped edge, which can smoothly pass through the limiting opening 411 and enter the inner side of the syringe 1. The quantitative baffle 311 with a fan-shaped plate structure can also more effectively contact with the limiting stopper 5, which is convenient for medical staff to align and operate.

It should be noted that the quantitative member 31 in the present invention can be fixedly arranged on the push rod 3, or can be fixed on the push rod 3 in a detachable connection manner. In a preferred embodiment, the quantitative member 31 is detachably connected to the push rod 3. By fixing the quantitative member 31 in a detachable connection manner, medical staff can change the injection amount of each quantitative injection at any time according to actual injection needs, which greatly improves the flexibility of use and the scope of application of the syringe.

It should be noted that the present solution can realize the detachable connection and fixation of the quantitative member 31 and the push rod 3 through various structural forms, for example, by providing a slot, buckle, pin hole and other structures on the push rod 3, and correspondingly, designing a matching plug block, buckle, latch and other structures at the connection end of the quantitative member 31, which can be conveniently assembled and disassembled. Preferably, a plurality of slots are provided in the axial direction of the push rod 3, and the quantitative member 31 is detachably plugged into the slots. When in use, the medical staff can insert the quantitative member 31 into different slots in the axial direction of the push rod 3 according to their injection needs.

Further preferably, in order to facilitate medical personnel to accurately position the quantitative member 31 , the present solution provides scale lines along the axial direction on the push rod 3 .

Next, the working process of the set-volume syringe with the structure shown in Figures 1 to 8 is introduced:

1) Exhaust before injection: The syringe 1 is filled with liquid medicine in advance, the head of the syringe 1 is facing upward, and the push rod 3 is pushed to exhaust the gas in the syringe 1. After the exhaust is completed, the quantitative member 31 closest to the push rod head is stuck at the outer end of the limit stopper 5;

2) Quantitative injection: rotate the push rod 3 90°, at this time, the quantitative member 31 closest to the push rod head rotates to the passing position, and the quantitative member 31 is separated from the limit stopper 5, so that the push rod 3 can continue to be pushed into the inner side of the syringe 1 for injection, until the next quantitative member 31 contacts the limit stopper 5, the first quantitative injection is completed; when performing the second quantitative injection, first rotate the push rod 3 90°, at this time, the second quantitative member 31 rotates to the passing position and just breaks away from the limit stopper 5, and continue to push the push rod 3 for the second quantitative injection, until the third quantitative member 31 contacts the limit stopper 5, the second quantitative injection is completed; the subsequent quantitative injection methods are similar;

3) Injection is completed: After the last quantitative injection is completed, at this time, the piston 2 reaches the head position of the syringe 1, and the end piece 32 on the push rod 3 is clamped on the outer end of the limit stopper 5. The push rod 3 cannot continue to be pushed into the syringe 1. Due to the mutual contact between the limit stopper 5 and the end piece 32, the deformation of the head of the piston 2 is prevented from penetrating into the cone head part of the syringe head, thereby avoiding the blood return phenomenon.

The present invention has the following beneficial effects:

1) This scheme sets the dosage of the segmented injection of the drug solution, and the injection stops automatically after the set dosage is reached, thus avoiding the situation where the injection volume is too large or too small, and ensuring the accuracy of quantitative injection;

2) This solution requires that before each quantitative injection, the push rod 3 needs to be rotated by a preset angle before the quantitative member 31 can be rotated to the passing position to ensure that the push rod 3 can continue to be pushed into the syringe 1, thereby preventing misoperation and improving the safety of segmented injection;

3) During the injection process, this solution allows medical staff to focus on the injection force and injection speed, thus improving the injection quality;

4) In the preferred embodiment, by providing a handle stop assembly 4 detachably connected to the handle 11 at the end of the syringe 1, a common syringe can be easily modified to have the function of segmented quantitative injection, thereby improving the application scope of the product;

5) In the preferred embodiment, a stopper 32 is provided on the push rod 3 to ensure that after the injection is completed, the stopper 32 is engaged with the limit stopper 5 to prevent the push rod 3 from continuing to be pushed into the syringe 1, thereby preventing the piston 2 from deforming after squeezing the syringe head and entering the hollow channel in the middle of the cone head, thereby preventing the negative pressure in the hollow channel from causing blood return when the piston 2 is deformed and restored, thereby improving the safety of injection.

The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims (13)

1. A set-meter syringe, comprising a syringe (1) and a push rod (3), characterized in that it also comprises a limit stopper (5), wherein the limit stopper (5) is fixed in an axial position relative to the syringe (1), and at least a portion of the projection of the limit stopper (5) along the axial direction of the syringe (1) is located on the inner side of the syringe (1), the push rod (3) can rotate relative to the limit stopper (5) around the axial direction of the syringe (1) and be pushed into the inner side of the syringe (1) along the axial direction, and at least one quantitative component (31) is distributed on the push rod (3) along the axial direction, and the push rod (3) drives each quantitative component (31) to pass through a blocking position and a passing position during the rotation relative to the limit stopper (5); When the quantitative member (31) follows the push rod (3) and rotates relative to the limit stopper (5) to a blocking position, there is an intersecting portion between the projections of the quantitative member (31) and the limit stopper (5) along the axial direction of the syringe (1) and located on the inner side of the syringe (1); When the quantitative member (31) follows the push rod (3) and rotates relative to the limit stopper (5) to a passing position, the quantitative member (31) and the limit stopper (5) are separated from each other in their projections along the axial direction of the syringe (1); When a plurality of the quantitative members (31) are arranged axially of the push rod (3), the blocking positions corresponding to each two adjacent quantitative members (31) in the axial direction differ by a preset angle within the rotation range of the push rod (3); The syringe also comprises a handle limit assembly (4), the handle limit assembly (4) comprising a handle connection mechanism and a limit stopper connection mechanism, the handle limit assembly (4) being detachably connected to the handle (11) at the end of the syringe (1) via the handle connection mechanism, and the limit stopper (5) being connected to the limit stopper connection mechanism; The stopper connection mechanism comprises a fixing plate (41), a stopper fixing ring (6), and a support tube (7) with openings at both ends; the fixing plate (41) is provided with a stopper opening (411) corresponding to the end tube opening of the syringe (1); the support tube (7) is fixed to one side of the fixing plate (41) and the tube opening of the support tube (7) is arranged opposite to the stopper opening (411); the support tube (7) is sleeved on the outer circumference of the push rod (3); the stopper fixing ring (6) is rotatably connected to the inner wall of the support tube (7) around the axis of the support tube (7); a stopper notch (71) extending in the circumferential direction is provided on the side wall of the support tube (7); the stopper fixing ring (6) is fixed with a lever (61) penetrating the stopper notch (71) and extending out of the support tube (7); and the stopper (5) is fixedly connected to the inner side of the stopper fixing ring (6); The handle connection mechanism comprises a clamping plate (42) arranged opposite to the fixing plate (41); the clamping plate (42) is connected and fixed to the fixing plate (41) via an intermediate connecting piece and a clamping gap (45) is reserved between the clamping plate (42) and the fixing plate (41); the clamping plate (42) is provided with a clamping opening (421) arranged opposite to the limiting opening (411); and a side edge of the clamping plate (42) is provided with an open clamping slot (422) communicating with the clamping opening (421). 2. The set-meter syringe according to claim 1, characterized in that, when a plurality of the metering members (31) are arranged on the push rod (3), the axial distance between each two adjacent metering members (31) is linearly related to the corresponding preset injection volume. 3. The set metered syringe according to claim 1 is characterized in that the inner wall of the support cylinder (7) is provided with a circumferentially surrounding annular guide rail (72), and the outer periphery of the limit stopper fixing ring (6) is provided with an annular groove (63) that cooperates with the annular guide rail (72). 4. The set metered syringe according to claim 3 is characterized in that the outer periphery of the limit stopper fixing ring (6) includes a first clamping ring (62) located at the upper end of the annular clamping groove (63) and a second clamping ring (64) located at the lower end of the annular clamping groove (63), the shift rod (61) is fixed to the outer side of the first clamping ring (62), the limit stopper (5) is fixedly connected to the inner side of the first clamping ring (62), the second clamping ring (64) is circumferentially distributed with at least one clamping notch (65), and the second clamping ring (64) is an elastic clamping ring structure that can be elastically deformed along its own radial direction. 5. The set metered syringe according to claim 1, characterized in that the limit stopper (5) comprises a first stopper (51) and a second stopper (52) arranged opposite to each other, and the first stopper (51) and the second stopper (52) are clamped on both sides of the outer periphery of the push rod (3). 6. The set-volume syringe according to claim 5 is characterized in that the main body of the push rod (3) comprises a plurality of long strip-shaped ribs (35), the length directions of the plurality of ribs (35) are all extended along the length direction of the push rod (3), and the plurality of ribs (35) are radially arranged around the axis of the push rod (3), and each of the quantitative members (31) is connected between two adjacent ribs (35). 7. The set metered syringe according to claim 6, characterized in that a plurality of serrations for clamping the rib plate (35) are provided on opposite sides of the first stopper (51) and the second stopper (52). 8. The set metered syringe according to claim 7, characterized in that the first stopper (51) and the second stopper (52) are symmetrically distributed with respect to the radial direction of the push rod (3), and the saw teeth are bidirectional through saw teeth; Alternatively, the first stopper (51) and the second stopper (52) are centrally symmetrically distributed relative to the center of the push rod (3), and the saw teeth are one-way passing saw teeth. 9. The set-meter syringe according to claim 6, characterized in that each of the metering members (31) comprises a pair of metering baffles (311), and the pair of metering baffles (311) are centrally symmetrically distributed relative to the axis of the push rod (3). 10. The set-volume syringe according to any one of claims 1 to 9, characterized in that the end of the push rod (3) located inside the syringe (1) is the push rod head, the end of the push rod (3) extending outside the syringe (1) is the push rod tail, and the push rod (3) is provided with a stopper (32) for limiting engagement with the limit stopper (5), the stopper (32) is located between the quantitative member (31) and the push rod tail, and the distance between the stopper (32) and the quantitative member (31) closest to the push rod head is less than or equal to the injection distance corresponding to the maximum injection volume of the syringe. 11. The set-meter syringe according to any one of claims 1 to 9, characterized in that the metering member (31) is detachably connected to the push rod (3). 12. The set-volume syringe according to claim 11, characterized in that a plurality of slots are axially provided on the push rod (3), and the quantitative member (31) is detachably plugged into the slots. 13. The set-volume syringe according to claim 12, characterized in that scale lines are arranged axially on the push rod (3).