NZ199049A - Applicator,pressure on forward end exposes needle and opens valve - Google Patents

Description

199049//201756 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION AFTER PROVISIONAL NO: 199049/201756 DATED; 24 November 1981 and 30 August 1982 IMPROVEMENTS IN AND RELATING TO APPLICATORS WE, WELLCOME NEW ZEALAND LIMITED , a New Zealand company of Great South Road, Auckland, New Zealand do hereby declare the invention for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement:- 220CTI9821 % 199049 201756 The present invention relates to an applicator and in particular to an applicator suitable for applying matter such as vaccines which are required to be applied by way of injection.

. The present invention has particular application to the application of vaccines to animals such as sheep, cattle, pigs and the like. It should however be appreciated that the invention has equal application to the application or injection of matter such as vaccines to humans. 10. Reference is made throughout the specification and claims to "matter to be applied" and it should be appreciated that this covers vaccines, liquid foodstuffs and other matter that is required to be applied by way of injection.

Up until this time numerous problems have been associated 15. with the application of matter by way of injection, and in particular problems have arisen in the area of application to animals such as for example sheep, cattle and pigs.

In arrangements provided up until this time, the needle or means for applying the matter has often been exposed. 20. This has been dangerous from the point of view of the people using the applicator and also dangerous from the point of view of the person or animal being injected. Due to exposed needles, they have often been broken off before, during or after application. This has therefore caused 25. infection and discomfort, as well as being generally inefficient and in some cases expensive.

C 199049 It has also been a problem with applicators used up until this time, that it has often been necessary and indeed difficult to hold an animal still while applying vaccine. For example it has often been necessary to first hold the animal, thereafter positioning a needle in the correct or desired position then entering the needle into the animal and thereafter actuating some appropriate means (such as depressing a plunger) to cause matter to be applied to be injected into the animal through a needle. This has been difficult and time consuming.

The present invention sets out to provide an applicator which overcomes or at least minimises these problems and which also provides a straight forward and efficient applicator for applying matter such as vaccine.

According to one aspect of this invention there is provided an applicator including an applicator head having a chamber and a needle; a proboscis being mounted about said needle, so as to be capable of axial movement relative thereto; at least one valve being provided between the chamber and the needle; said proboscis being so mounted relative to the needle, that rearward axial movement of the proboscis over the needle, on application of pressure to a forward end thereof,at least partially exposes a forward end of said needle; the arrangement being such that matter is thereafter caused to pass from the chamber through the needle, by way of said valve.

According to a further aspect of this invention there is provided an applicator including a reservoir and an applicator head having a chamber and elongate needle; the needle bej^^^? /'' S£ 199049 #0CT1935 partially surrounded by a proboscis adapted for axial movement relative to the needle; valve means being provided between the chamber and the needle; further valve means being provided between the reservoir and the chamber; triggering means being provided to cause the passage of matter to be applied from said reservoir into said chamber; the proboscis being so mounted relative to the needle that rearward axial movement of the proboscis over the needle, by application of pressure to a forward end thereof, at least partially exposes a forward end thereof; the arrangement being such that matter to be applied is thereafter caused to pass from said chamber through said needle, by way of said valve between the chamber and needle.

The invention will now be described by way of example only and with reference to the accompanying drawings, wherein: Figure 1: shows a side exploded view of an applicator head ofone form of the invention, connected to an upper portion of a reservoir according to one form of the invention.

Figure 2; is a side and partially exposed view of the handle arrangement incorporating the head member and showing the chamber in a substantially loaded condition.

Figure 5: is a side and partially exploded view of the applicator including the housing and showing the chamber in its released or unloaded position.

Figure 4: is a side view of thevhousing incorporating the head member and reservoir according to one form of the invention. 199049 20173® Preferably, the present invention provides an applicator for applying matter such as vaccine to animals.

The applicator of the present invention includes a reservoir 1 for vaccine and a head member 2, which are 5. securely attached one to the other in a substantially sealed arrangement. The combined head member 2 and vaccine reservoir 1 are preferably formed of a plastics material and are disposable. It is envisaged that once an amount of vaccine provided in the reservoir 1 has been utilised, the connected 10.or combined head member and reservoir can be disposed of and replaced.

A suitable housing 5 (with reference to Figure 4 of the accompanying drawings) is provided which locates the head member 2 and reservoir 1 in a substantially releaseable 15 .engagement and this will be described hereinafter.

The head member 2 includes a needle or other injection member having a bore therethrough, for the passage of matter to be applied, this hereinafter being referred to as "a needle". An elongate needle 3 is located within suitable 20.guides and mountings 4 and is surrounded by a housing or covering, such as a protective housing, covering or proboscis 6, (hereinafter referred to as a "proboscis").

In the form of the invention shown in the drawings, the proboscis is substantially elongate, conical and tapering 25.in formation, being open at the point end of the needle 3, and located relative to the head member so that it is axially movable relative to the longitudinal axis of the needle 3.

The proboscis 6 substantially covers the length of 199049 201756 the needle 3 when not in use.

The head member 2 also provides a vaccine chamber 8, which communicates with the needle 3 by way of valving 10, the valving 10 being located in the head member 2 substant-5. ially intermediate the chamber 8 and needle 3.

The valve 10 between the needle 3 and the chamber 8 includes a valve plate 12 and "O" ring 13 adapted to be sealed against a valve seat. Valve actuating means 15 such as arms with buttons 15a on the end thereof, extend outwardly 10. from the valve plate 12, inwardly of the proboscis 6.

The proboscis 6 is formed or provided with an inner skirt portion, which forms a valve actuating portion or means 6a of the proboscis.

When the proboscis 6 is in the position of rest, sub-15. stantially covering the needle, the valve actuating means 6a of the proboscis and the valve actuating means 15 associated with the valve 10, are spaced apart one from the other.

On movement of the proboscis 6 relative to the needle 3, the valve actuating means 6a of the proboscis is 20. caused to move against the valve actuating means 15 of the valve 12, this opening the valve 12, between the chamber 8 and the needle 3, and allowing matter to pass from the chamber 8 through needle 3.

The location and spacing of the proboscis relative to the 25. needle and chamber, can ie varied, to thus vary the distance required to be travelled by the proboscis before the valving between the chamber and needle is actuated. This then determines the amount of needle to be exposed by actual movement of the proboscis and thus also the depth to which the needle 199049 can penetrate through the skin of the animal.

In this way, it will be appreciated that the required depth or amount of penetration of the nieedle can be varied or determined. Thus, axial movement of the proboscis 6 will not actuate valving between the chamber 8 and needle 3 (to 5. thus deliver a shot or measure of vaccine), until the predetermined amount of needle 3 has been exposed and thus until the needle has penetrated the skin of an animal to the desired depth.

Thus, if for example the needle cannot penetrate to the 10.correct depth, having regard for example to a bone being struck or if the injector or needle is placed against a resisting surface, vaccine delivery is prevented.

The chamber 8 is designed to hold a shot or measure of vaccine for delivery into an animal through the needle 3. 15. On axial movement of the proboscis 6 relative to the needle 3, theproboscis which is preferably spring biased, moves against the bias of the spring toward the chamber 8, so that the valve actuating means 6a of the proboscis 6 come into contact with the valve actuating means 15 of the valve 12, 20.between the chamber 8 and needle 3. This will then cause the valve 10 and "O" ring 13, to move away from the valve seat to thus communicate the chamber 8 with the needle 3. The measure or shot of vaccine will then be caused to pass from the chamber 8 through the needle 3, to be discharged into an animal. 25. The reservoir 1 and head member 2 are preferably connected in a permanent or semi-permanent sealed connection. 199049 201750 8b and passage means are provided to connect the chamber 8 with the reservoir 1.

A feed tube 11 preferably leads up from within the reservoir 1, and is connected to an outlet and valving la and the 5. upper end of the reservoir, which is connected to the chamber 8 by the passageway 8b.

The valve la between the reservoir 1 and chamber 8 is preferably a non-return valve.

The chamber 8 is formed with one wall 8a as a movable 10.or flexible wall, which can for example be in the form of a flexible diaphragm, a piston or a ram. These are by way of example only however.

Preferably, the wall 8a is in a form of a flexible diaphragm, preferably constructed of a flexible plastics 15.material, which is sealed to the chamber 8 so as to form a sealed but flexible wall which is capable of movement inwardly and outwardly of the chamber 8.

The movable wall 8a is connected to or formed with spring biased actuating means 26, the actuating means 26 20.being biased so as to extend the flexible diaphragm 8a into a position in which it extends inwardly into the chamber 8. A first actuating member 26a is connected to the rear side of the diaphragm 8a and is releaseably engageable or locatable with a second actuating member 26b which provides 25.the spring bias referred to hereinbefore, when the first and second actuating members 26a and 26b are interconnected.

The flexible diaphragm 8a is also naturally biased into a position into which it extends inwardly of the chamber 8. 199049 201756 _9_ On operation of the actuating means 26, as will be described hereinafter, the flexible diaphragm 8a is pulled outwardly of the chamber 8 against the bias of the actuating spring 27, this drawing the non-return valve la between the reservoir 1 5. and head member 2 upwardly and open within its guides lb and at the same time sucking or drawing up vaccine from within the reservoir. The outward movement of the diaphragm 8a then sucks or draws a measure or shot of vaccine up into the chamber and when it is in the chamber the pressure of the vaccine forces 10.the non-return valve la between the reservoir 1 and head member 2 back down into its closed position to thus close and seal a measure or shot of vaccine within the chamber 8.

The measure or shot of vaccine is then held within the chamber 8 under pressure, between the closed valves la and 10, 15.and under pressure from the flexible diaphragm 8a and the spring biased actuating means 26, which urges the diaphragm 8a inwardly of the chamber 8.

In use, once a measure or shot of vaccine has been loaded into the chamber 8, (such as in the manner hereinbefore 20 .described), the proboscis 6 is placed against an animal in the desired position and a downward pressure applied to the head member 2 by an operator. This will cause the proboscis 6 to move axially relative to the needle 3 and against the bias of the proboscis spring, such as to bring the proboscis valve 25.actuating means 6a into contact with the actuating means 15 of the valve 10 between the chamber 8 and needle 3, this pressure causing the valve 10 between the chamber 8 and needle 3 to be opened. The opening of this valve 10 will cause the measure or shot of vaccine within the chamber 8 to exit from the chamber 8 199049 201756 through the needle 3, with some force, assisted by the spring biased flexible diaphragm 8a which will urge the shot or measure of vaccine out of the chamber 8.

The present invention provides for the head member 2 and 5.reservoir 1 to be releaseably locatable within a housing 5, the housing 5 providing also triggering means and actuating means for loading a shot or measure of vaccine into the chamber 8. The housing 5 also provides for a handle grip for use by an operator, and a counting mechanism whereby the 10.operator can keep count on the number of shots or measures delivered by the applicator.

Referring to Figure 4 of the accompanying drawings, the housing 5 is shown as incorporating an upper body portion 30, the forward upper body portion 31 being adapted to release-15.ably locate the head member 2 in appropriate supports and lugs. A front side 32 is hingeably attached to the upper body portion 30 so as to be capable of being opened for location of the head member and closed over and about (and so as to locate) the head member 2 in position. Suitable releaseable locking means such 20.as a locking bolt, clip and the like can be provided, to open and close the front side 32 of the housings. In other forms of the invention, the housing can be provided with a pivotally or hingeably mounted upper wall portion for location and removal of the head member. These are however by way of example only and 25.other variations are envisaged as being possible.

The rear upper body portion 33 locates the actuating means 26 (as hereinbefore referred to) and as will be described further hereinafter. ' 199049 201756 The rear upper body portion 33 leads into a downwardly extending handle portion 34, which defines a grip opening 34a in which is pivotally located triggering means 35.

The housing further includes a lower body support member 5. which is below, spaced apart from and substantially parallel to the forward upper body portion 31 so as to define a spacing therebetween, in which the reservoir can be located. A suitable slot or recess can be provided in the lower face of the support member 36, in which can be located a tab portion lc 10.of the reservoir 1.

Referring further to Figures 2 and 3 of the accompanying drawings, these drawings show exploded views of the actuating and triggering mechanism of the applicator as located within the housing 5.

. Figure 2 of the accompanying drawings shows the trigger ing and actuating mechanisms in position in which the diaphragm 8a of the chamber 8 has been withdrawn and in which a shot or measure of vaccine is within the chamber 8. This is prior to movement of the proboscis 6 relative to the needle 3 and thus 20.the opening of the valve 10 between the chamber 8 and needle 3.

Figure 3 of the accompanying drawings shows the triggering and actuating mechanisms in position prior to the loading of a measure of shot of vaccine into the chamber 8 and in this position the diaphragm 8a is shown as being in its relaxed 25.position extending inwardly of the chamber 8, in accordance with the urging of the spring bias of the actuating means 26.

The actuating means 26 located within the housing incorporates an actuating member 26b, which is located in the rear portion 33 of the housing 5. 199049 201756 An actuating spring 27 is provided about the actuating member 26b and within spring guides 41 to urge the actuating member outwardly of the housing 5 and towards the chamber 8.

The actuating member 26a is provided with a suitable conn-5. ection head 26c, to enable it to be releaseably connected to an adjacent slotted end 26d of the actuating member 26b. Thus, on location of the head member 2, and reservoir 1, within the housing 5, the actuating members 26a and 26b are releaseably engaged one with the other.

. A trigger 35 is provided and is mounted for pivotal movement, rearwardly, within the grip opening 34a of the handle 34 in accordance with arrow "A" as shown in the accompanying drawings.

The trigger 35 is connected at its upper end, to a pivot-ally connected crank lever 48 which is connected to a further 15.pivot lever 49 which engages with the lower portion of the crank lever 4 8 in its position of rest as shown for example in Figure 3 of the accompanying drawings. A trigger spring 50 connects the trigger 35 and an inner surface of the housing 5, to urge the trigger into its position as shown in Figure 3 of 20.the accompanying drawings, in which the diaphragm 8a is inwardly of the chamber 8.

A counting mechanism 54 is provided, being provided with an actuating or operating tab or finger 55, the counting mechanism also being provided with a dial or face rearwardly of 25.the housing, which is covered by suitable glass or perspex so that it can be viewed exterior of the housing. A dial capable of showing the number of measures or shots delivered by the applicator is provided and is capable of being seen through the aforementioned glass or perspex. The counting 199049 201*356 mechanism 54 operates such that on movement or actuation of the finger 55, the counter will be caused to move on one digit, thus keeping a clear indication as to the number of shots or measures.

Referring now to Figure 3 of the accompanying drawings, the 5. trigger 35 is shown as being in a position of rest and on depression of the trigger, the trigger and the pivotally connected crank lever 48 are caused to move rearwardly. The crank lever 4 8 is connected to the butt end of the actuating member 26b and thus the movement or depressing of the trigger 35 and movement 10.of the crank lever 48, draws the actuating means 26 away from the chamber and against the bias of the spring 27 passing about the actuating member 26b, this causing the diaphragm 8a to be moved or drawn outwardly of the chamber 8. As described hereinbefore, this opens the valving la between the reservoir 1 and 15 # chamber 8, sucking or drawing a shot or measure of vaccine into the chamber 8 for delivery. On full depression of the trigger, the crank lever 48 and additional lever member 49 are disconnected such as shown in Figure 3 of the drawings in which the trigger is disengaged from operation with the actuating means 26. 20. Referring to Figures 2 and 3 of the drawings, the crank arm 48 is formed at its lower end with a substantially flexible hook member or portion 48b.

The trigger 35 pivotally mounts the pivot lever 49, which has two interconnected arms 49a and 49b. The pivot lever 49 25.is pivotally mounted substantially about its mid point 49f, and is of a substantially bifurcated, splayed or "V" formation.

Free movement or rotation of the pivot lever 49 is prevented by pivot control stops or pins 49c and 49d which allow for pivotal movement of the pivot pin 49 but which 199049 201756 restrict movement to prevent free rotation.

The pivot lever 49 is spring biased into a position in which it is biased towards the lower control pin 49d.

An elongate slot 35b is provided in the handle 35 and the 5# control pin 49d extends through the slot. The slot 35b therefore allows for movement of the trigger relative to control pin 49d.

The upper control pin 49c is mounted to and integral with the trigger.

Referring now to Figure 2 of the accompanying drawings. On 10.the trigger 35 being depressed rearwardly in the direction of arrow "A" in Figure 2 of the drawings, the engaged arm 49a and hook 4 8b of the crank arm, are moved rearwardly until the hook 48a of the crank arm 48 comes into contact with the rear wall of the housing, and in particular an abutment 75 on the rear wall 15.of the housing.This then causes the crank arm 48 and pivot lever 49 to disengage one from the other. The depressing of the trigger 35 will cause the pivot lever 49 and connected crank arm 4 8 to draw the actuating member 26 rearwardly against the bias of the spring 27, and to thus move the movable wall or 20.diaphragm 8a of the chamber 8 rearwardly, this drawing a shot or measure of matter to be applied into the chamber 8.

On the pivot lever 4 9 and crank arm 4 8 being disengaged one from the other, the actuating means 26 is able to be free for uninhibited discharge, thus allowing free and uninhibited 25.movement of the actuating means 26, in order to deliver the shot or measure of matter to be applied, irrespective of the trigger position.

On disengagement of the pivot lever 49 and the crank arm 48, the trigger is still able to be depressed such as 199049 201756 would be the case when the applicator would be gripped by an operator, who following the applicator being loaded with a measure of charge of vaccine, wishes to grip the applicator firmly, (involving the depressing of the trigger) as he 5. applies the matter to the animal.

On the applicator being applied to an animal such as to deliver a shot in the manner hereinbefore described, and on the valving 10 between the chamber 8 and needle 3 being opened, the urging of the spring biased actuating means 26 10. against the diaphragm 8a will assist in forcing a measure or shot out of the chamber 8 as soon as the valve 10 opens, this effectively delivering a shot or measure of vaccine through the needle.

Following discharge of the matter from within the 15.chamber, the actuating means 2 6 and crank arm 4 8 will return to the position shown in Figure 3 of the drawings, but the trigger will still be free of engagement with the crank arm 48, and still capable of being depressed.

On the trigger being released, such as being released by an operator, it will be returned such as by trigger spring 50 20. to the position substantially shown in Figure 3 of the accompanying drawings, the substantially flexible hook member 48b of the crank arm 48, flexing and riding over the end of the arm 49a of the pivot lever 49, so that the pivot arm 49 and crank lever 4 8 are inter-engaged so that a further loading 25.of the applicator can take place.

On the trigger 35 being depressed and on the crank lever 48 being pivoted to move the actuating means 2 6 rearwardly, an operating or cam face 48a of the crank lever 48 is caused to 199049 20-n56 move against the operating finger 55 of the counting mechanism 54 to thus actuate the counting mechanism to indicate that a shot or measure has been loaded and will be delivered.

. It is preferred in this invention that the head member 2 and reservoir 1 are constructed of a plastics material so as to be readily disposable when desired. The housing is preferably, although not essentially, formed or moulded from an appropriate plastics material, so as to be light and straight 10.forward to use and handle. This is however.by way of example only.

In one form of the invention, the chamber 8 can be provided with a relief or bleeder valve or opening. Preferably, this is provided in an upper or top side of the chamber 8. The 15.bleeder valve can be in the form of a hole or recess being provided with a suitable closure or cap. In preferred forms of the invention the suitable closure or cap is connected by means of an integral strap, to an adjacent portion of the head member. It has been found in use, that on applying 20.pressure to the reservoir, such as in the form of a "squeeze" matter to be applied will be forced up through the chamber 8 and out of the bleeder valve.

The particular advantage with this is that when an applicator is being used, there may be some air in the reservoir 25.prior to, or during, use. By the reservoir being squeezed in themanner set out above, air can be extinguished from the reservoir by way of the bleeder valve.

Thus, to allow for such exit of air, prior to use, the cap can be removed from the bleeder valve. The reservoir is then ^99049 20175G squeezed to exit air from the reservoir through the bleeder valve. Once air has been extinguished from the reservoir (such as when liquid starts exiting from the bleeder valve), the cap is replaced. This then closes the bleeder valve.

It has been found that the provision of such a bleeder valve 5. and cap prevents or at least reduces air pockets forming in the chamber 8, which can in some cases detract from the effectiveness and efficiency of the invention.

This invention has been described by way of example only, and it will be appreciated that improvements, and variations 10. may be made within the scope and spirit of the claims as appended hereto. 139049

Claims (26)

WHAT WE CLAIM IS:

1. An applicator including an applicator head having a chamber and a needle; a proboscis being mounted about said needle, so as to be capable of axial movement relative thereto; at least one valve being provided between the chamber and the needle; said proboscis being so mounted relative to the needle, that rearward axial movement of the proboscis over the needle, on application of pressure to a forward end thereof,at least partially exposes a forward end of said needle; the arrangement being such that matter is thereafter caused to pass from the chamber through the needle, by way of said valve.

2. An applicator as claimed in claim 1, wherein the applicator is a multiple dosage applicator.

3. An applicator as claimed in claim 1 or claim 2, including a reservoir holding a plurality of dosages, and a one way valve connecting the reservoir to the chamber for supplying substantially one dosage at a time to said chamber.

4. A multiple dosage applicator including an applicator head having a chamber and an elongate needle; a proboscis being mounted about said needle, so as to be capable of axial movement relative thereto; at least one valve being provided between the chamber and the needle; said proboscis being so mounted relative to the needle, that on rearward axial movement of the proboscis over the needle, by application of pressure to a forward end thereof,"' 199049 / X 2G1756 -19- a forward end of the needle is at least partially exposed; the arrangement being such that matter to be applied is thereafter caused to pass from said chamber through said needle, by way of said valve.

5. An applicator including a reservoir and an applicator head having a chamber and elongate needle; the needle being at least partially surrounded by a proboscis adapted for axial movement relative to the needle; a valve being provided between the chamber and the needle; a further valve being provided between the reservoir and the chamber; triggering means being provided to cause the passage of matter to be applied from said reservoir into said chamber; the proboscis being so mounted relative to the needle that rearward axial movement of the proboscis / over the needle, by application of pressure to a forward end thereof, at least partially exposes a forward end thereof; the arrangment being such that matter to be applied is thereafter caused to pass from said chamber through said needle, by way of said valve between the chamber and needle.

6. An applicator as claimed in any one of the preceding claims, wherein the proboscis includes valve actuating maano; valving between the chamber and needle including valve actuating members; axial movement of the proboscis relative to the needle causing the proboscis valve actuating means to come into contact with the actuating 199049/ '2G175& -20- members of the valve between the chamber and the needle, such that the valve between the chamber and the needle is ouctDod to open.

7. An applicator as claimed in claim 5, wchroin the valve between the reservoir and the chamber is a non-return valve.

8. An applicator as claimed in any one of the preceding claims, wherein the chamber includes at least one movable wall.

9. An applicator as cliamod in claim 8, wherein the movable wall is in the form of a flexible diaphragm.

10. An applicator as claimed in claim 8, wherein the movable wall is in the form of a piston.

11. An applicator as claimed in claim 5, wherein the chamber includes a movable wall; actuating means being connected or formed with the movable wall, so as to move the wall inwardly and outwardly of the chamber.

12. An applicator as claimed in claim 11, wherein the actuating means is spring biased so as to urge the wall inwnrlay of the chamber.

13. An applicator as claimed in either of claims 11 or 12, wherein the triggering means are linked to the actuating means, connected to or fomcd with said movable wall of the chamber; operation of the triggering means causing the actuating means to move the wall outwardly of said chamber, so as to draw a shot or measure of matter to be applied into the chamber. -21- 199049/201756

14. An applicator as claimed in claim 13, wherein the triggering means is connected by a lever arrangement to the actuating means of the movable wall of the chamber.

15. An applicator as claimed in claim 13 or claim 14 wherein a crank arm is connected to the end of the actuating means; the triggering means mounting a pivot lever; the crank arm and pivot lever being engageable one with the other, such that on the triggering means being depressed, the engaged pivot lever and crank arm will cause the actuating means to move the wall outwardly of the chamber.

16. An applicator as claimed in claim 15, wherein the pivot lever is formed with upper and lower arms, the pivot lever being pivotally mounted substantially about its mid-point to the triggering means; pivot stops being provided adjacent the upper and lower arms to prevent free rotation of the pivot lever.

17. An applicator as claimed in claim 15 or claim 16, wherein the crank arm is provided with a flexible hook at a lower end thereof, which is engageable with the upper arm of the pivot lever. -22- 1B9049

18. An applicator as claimed in any one of the preceding claims 15 to 17, wherein abutment means are provided, such that on the triggering means being depressed, the engaged carnk arm and pivot lever are drawn rearwardly to come into contact with the abutment means, which contact releases the crank arm from the pivot lever.

19. An applicator as claimed in claim 18, wherein spring means are provided to return the triggering means to an undepressed position, following disengagement of the crank arm and pivot lever.

20. An applicator as claimed in any one of the preceding claims 15 to 19, including a counting mechanism to indicate each shot or measure delivered, the counting mechanism including a display face and an operating finger which is actuated by contact with the crank arm, on operation of the triggering means.

21. An applicator as claimed in any one of the preceding claims 5A-te- -5H* including a housing adapted to releaseably locate the applicator head and reservoir; the housing body support member; a rear upper body portion leading into a downwardly extending handle portion defining a grip opening; the handle portion pivotally mounting the V triggering means within the grip opening; at least +o "7 onol II -4o 7.0 including an upper body portion and a spaced apart lower 189049/201756 -23- part of the upper body portion being adapted to roloaoably locate said applicator head; the reservoir being releaseably locatable between a forward upper body portion and the spaced apart lower support member.

22. An applicator as claimed in claim 21, when dependent on claim 15^wherein the actuating means includes first and second actuating means; said first actuating means being attached to the movable wall of the chamber so as to be * releaseably locatable within the upper body portion of the beivo| Mf'Jl housing and s^e) connect able to spring biased second yS actuating means provided within the housing; the second corps'"c*v-?v—v and actuating means being connected by a lever arrangementAto the triggering means; the arrangement being such that on location of the applicator head and reservoir within said housing, and on connection of the first and second actuating means, operation of the triggering means will cause the lever arrangement to move the interconnected first and second actuating means, against spring bias, to draw the movable wall outwardly of the chamber, this opening valving between the reservoir and chamber and drawing a shot or measure of matter to be applied from the reservoir into the chamber, where it is held under pressure from the spring biased actuating means.

23. An applicator as claimed in any one of the preceding claims 5 to 22 wherein the applicator head and reservoir are sealably connected one to the other. -24- 199049

24. An applicator as claimed in any one of the preceding claims wherein a bleeder valve is formed or provided in an upper wall of the chamber.

25. An applicator as claimed in claim 24, wherein the bleeder valve is provided with a replaceable cap or cover.

26. An applicator substantially as hereinbefore described with reference to the accompanying drawings. WELLCOME NEW ZEALAND LIMITED By Their Attorneys, BALDWW-ySON & CAREY.