GB2313548A - An Applicator - Google Patents

Abstract

A vaccine scratch applicator having a body having a handle. The body includes a cavity 23 to slidably receive a vial 14 containing the vaccine. The vial 14 engages a piston member 28 to cause reciprocation thereof. Movement of the two part piston member 28 delivers the vaccine to a position adjacent a scratch blade 16 via two variable volume chambers. The liquid reaches the variable volume chambers through a duct 37 which passes from the vial 14 through the piston member 28, and exits from the chambers via a valved duct 43. A third valved duct 39 allows air into the vial to replace liquid expelled therefrom. The handle may contain storage areas for spare vials and blades (20).

Description

An Applicator The present invention relates to devices to deliver medication to animals.

Currently available applicators are not particularly suited to deliver an extremely accurate and consistent relatively minute volume of a medication to animals. More particularly, previously known devices are not well adapted to deliver such small doses to an abrasion on the skin of an animal.

Disclosed in International Patent Application PCT/NZ95/81 (International Publication No. WO 96/07369) is a scratch vaccine applicator. The applicator receives a vial which delivers vaccine to a scratch blade. Upon the blade being applied to the skin of an animal to scratch the epithelial layer, without completely penetrating the lower endothelial layer, the vaccine is allowed to flow from the vial to a position adjacent the blade. This device has the same disadvantages of the above discussed applicators, that is it would not consistently deliver an accurately measured dose of vaccine. A still further disadvantage is that the item is intended to be thrown away rather than the vial merely being replaced.

It is the object of the present invention to overcome or substantially ameliorate the above disadvantages.

There is disclosed herein an applicator comprising: a body to be gripped by a user, said body including a reservoir receiving portion, said portion including said first and second surfaces, which surfaces have generally parallel longitudinal axes; a piston member including a first piston portion engaged with said first surface so as to cooperate therewith to substantially enclose a first variable volume chamber, a second piston portion engagable with said second surface and to cooperate therewith to substantially enclose a second variable volume chamber; first duct means extending to said first chamber to deliver a liquid thereto; second duct means, said second duct means extending from said second chamber to a position at which said liquid is ejected from said applicator; and wherein an operator causes reciprocation of said piston member between a first position at which said chambers have a first volume and a second position at which said chambers have a second volume less than said first volume, to cause liquid to be delivered to said first chamber from where it flows to said second chamber and is ejected therefrom via said second duct upon said second chamber being reduced in volume.

Preferably, the piston member would be provided with a hollow stem which would enter the reservoir so as to draw the liquid therefrom to be delivered from said second duct.

The hollow stem would communicate with the first duct means.

In a still further preferred form there would extend from the piston member a further hollow stem to enable air to be delivered to the interior of the reservoir while liquid is withdrawn therefrom.

In a still further preferred from the reservoir would abut the piston member and a user would apply a force to the reservoir to cause reciprocation of the piston member.

In a still further preferred form the applicator is a scratch vaccine applicator having a scratch blade mounted on said body and to which said second duct means extends to deliver vaccine to a position adjacent the scratch blade.

There is further disclosed herein a device to deliver a liquid dose, said device comprising: a body having a first and a second cylindrical surface, which surfaces are coaxial; a piston member having a first piston portion cooperating with said first surface to substantially enclose a first variable volume chamber, and a second piston portion to cooperate with said second surface to substantially enclose a second variable volume chamber; first duct means extending from said first chamber through which a liquid is delivered from a reservoir to said first chamber; second duct means extending from said second chamber from which the liquid dose is delivered; and wherein said piston member is movable between a first position at which said first and second chambers are operatively connected so that liquid may pass therebetween, and a second position at which said second piston portion is associated with said second surface to separate said first and second chambers, with said liquid dose being delivered by a reduction in the volume of said second chamber.

A preferred form of the present invention will now be described by way of example with reference to the accompanying drawings wherein: Figure 1 is a schematic side elevation of an applicator to apply vaccine to an animal; Figure 2 is a schematic part sectioned side elevation of the applicator of Figure 1; Figure 3 is a schematic part sectioned side elevation of the forward portion of the applicator of Figure 1; and Figure 4 is a schematic further part sectioned side elevation of the forward portion of the applicator of Figure 1.

In the accompanying drawings there is schematically depicted an applicator 10 which is held in the palm of the hand during use. The applicator 10 includes a body 11 having a handle 12 which is gripped by the user, and a forward portion 13 which receives a reservoir (such as a vial 14) containing a live vaccine. The forward portion 13 is also provided with a scratcher tip 15 including a blade 16. In operation, the blade 16 is passed across the skin of the animal so as to produce an abrasion. The user presses on the vial 14 which causes the vaccine to be delivered via the tip 15. The live vaccine delivered to broken skin enables the vaccine to enter the animals blood stream.

Preferably, the vaccine would be delivered to the blade before the skin is scratched.

The handle 12 is of a two-part structure so as to have a first part 17 to which there is pivotally attached a second part 18. The parts 17 and 18 are secured together by means of a hinge 19. The parts 17 and 18 cooperate to provide a cavity in which extra vials 14 are stored. Still further, the forward portion 13 is provided with cavities 20 in which additional scratcher tips 15 may be stored.

Extending from the body 11 is a guard 21 including a projecting portion 22 which is resiliently deflectable, as best seen in Figure 1, from a first position generally covering the blade 16, to a retracted position at which the blade 16 is exposed for use. The projecting portion 22 is deflected upon contact with the skin of the animal. The handle portions 17 and 18 are pivotally movable from a folded configuration, as shown in Figure 1, to an unfolded position as shown in Figure 2 providing access to the additional vials 14 and additional scraper tips located in the cavities 20.

The forward portion 13 provides a cavity 23 within which the vial 14 is mounted and is slidably guided by the walls surrounding the cavity 23. The forward portion 13 is also provided with a cylindrical sleeve 24 providing a cylindrical surface 25. Coaxial with the surface 25 is a further cylindrical surface 26 of smaller radius. Located between the surfaces 25 and 26 is a seal 27. Cooperating with the cylindrical surfaces 25 and 26 is a piston member 28. The piston member 28 includes a first piston portion 29 which engages and cooperates with the surface 25 to provide a first variable volume chamber 30. Extending from the first piston portion 29 is a second piston portion 31, which cooperates with the cylindrical surface 26 to provide a second variable volume chamber 32. The second piston portion 31 is movable to a position sealingly engaging the seal 29, while the first piston portion is provided with a seal 33 which slidably sealingly engages the cylindrical surface 25.

Surrounding the sleeve 24 is a cavity 34 which receives a spring 35. The spring 35 extends between the forward portion 13 and the piston member 28, urging the piston member 28 to move to a position maximising the volume of the chambers 30 and 32. The forward portion 13 has an annular flange 36 to retain the piston member 28 within the forward portion 13.

Extending from the piston member 28 is a first hollow stem 37, which stem 37 extends to a first passage or duct 38. The passage 38 extends so as to communicate with the first chamber 30. Also extending from the piston member 28 is a second hollow stem 39 which is pointed. The stem 39 extends to a passage 40 containing a one-way valve assembly 41. The valve assembly 41 communicates with the surrounding atmosphere so that in use air is allowed to enter the vial 14 as liquid is withdrawn therefrom. The one-way valve 41 prevents liquid exiting via the passage 40. The stem 39 has a pointed end to enable the stems 37 and 39 to penetrate a rupturable membrane covering the neck of the vial 14.

Extending from the chamber 32 is a second passage 42 including a one way valve 43. The valve 43 ensures that only liquid moves away from the chamber 32. Extending from the valve 43 are passages 44 which extend to openings adjacent the blade 16 so that the vaccine is delivered to the blade 16.

The above described preferred form of the present invention, the applicator 10, enables extremely accurate and consistent minute volume doses to be delivered. For example, 0.01 millilitres can be accurately measured and dispensed after having been directly taken from a vial of 10 to 50 millilitres in volume, containing a live vaccine.

In operation of the above described applicator 10, a user inserts the vial 14 in the cavity 23 so that the stems 37 and 39 pierce the rubber stopper closing the top of the vial 14. A user places the handle 12 in the palm of the hand as illustrated and applies pressure to the end face 44 with the thumb. By pressing down on the end face 44 the spring 35 compresses so that the piston member 28 moves towards the blade 16. This movement causes reduction in the volume of the chambers 30 and 32. Upon the vial 14 being released by the.thumb, the spring 35 moves the vial 14 away from the blade 16 so that the volume of the chambers 30 and 32 increases to a maximum. This position is defined by abutment of the piston member with the flange 36. The vaccine in the vial 14 is then drawn into the chambers 30 and 32. This process is repeated until all air is driven from the chambers 30 and 32. When pressure is again applied to the end face 44 to move the piston member 28, vaccine is ejected from the tip 15 when the piston 31 engages the seal 27 and further moves to reduce the volume of the chamber 32.

The one-way valve 41 permits air to enter the interior of the vial 14 as liquid is drained therefrom. The one-way valve 43 ensures that liquid can only flow from the chamber 32 in the direction toward the blade 16 (thereby preventing reverse flow) when the piston member 28 retracts.

In the above described embodiment the body 11 includes a handle 12 which is gripped by the user. This arrangement can be modified so that the handle 12 is eliminated. In such an instance the forward portion 13 would be enlarged so that a user may grip the applicator 10 by grasping the forward portion 13.

Claims (16)

1. An applicator comprising: a body to be gripped by a user, said body including a reservoir receiving portion, said portion including said first and second surfaces, which surfaces have Generally parallel longitudinal axes; a piston member including a first piston portion engaged with said first surface ;o as to cooperate therewith to substantially enclose a first variable volume chamber, a second piston portion engagable with said second surface and to cooperate therewith to substantially enclose a second variable volume chamber; first duct means extending to said first chamber to deliver a liquid thereto; second duct means, said second duct means extending from said second chamber to a position at which said liquid is ejected from said applicator; and wherein an operator causes reciprocation of said piston member between a first position at which said chambers have a first volume and a second position at which said Chambers have a second volume less than said first volume, to cause liquid to be delivered to said first chamber from where it flows to said second chamber and is ejected therefrom via said second duct upon said second chamber being reduced in volume.

2. The applicator of claim 1, wherein said first and second surfaces are coaxial cylindrical surfaces with said second surface having a smaller radius than said first surface.

3. The applicator of claim 1 or 2, wherein said second piston portion moves into sealed cooperation with said second surface when said piston member is moving from its first position to its second position, and said second chamber is open to aid first chamber when said piston member is in its first position.

4. The applicator of claim 1, 2 or 3 further including a hollow stem which is to extend from the reservoir to draw liquid therefrom and which communicates with said first chamber.

5. The applicator of any one of claims 1 to 4 further including means to deliver air to the interior of the reservoir.

6. The applicator of any one of claims 1 to 5 further including a valve in said second duct means restricting liquid to flow from said second chamber to said position at which said liquid is ejected from said applicator.

7. The applicator of any one of claims 1 to 6 further including a spring urging said piston member to move from its second position to its first position.

8. The applicator of any one of claims 1 to 7 wherein said applicator is a cratch vaccine applicator having a scratch blade mounted in said body and to which aid second duct means to deliver a vaccine which would be drawn from the reservoir.

9. The applicator of any one of claims 1 to 8 wherein said piston member is adapted to engage the reservoir, so that the reservoir is positioned to be engaged by an operator to cause movement of the piston from the first position thereof to the second position thereof.

10. The applicator of claim 8, wherein said body includes a cavity to slidably receive the reservoir.

11. A device to deliver a liquid dose, said device comprising: a body having a first and a second cylindrical surface, which surfaces are coaxial; a piston member having a first piston portion cooperating with said first surface to substantially enclose a first variable volume chamber, and a second piston portion to cooperate with said second surface to substantially enclose a second variable volume chamber; first duct means extending from said first chamber through which a liquid is delivered from a reservoir to said first chamber; second duct means extending from said second chamber from which the liquid dose is delivered; and wherein said piston member is movable between a first position at which said first and second chambers are operatively connected so that liquid may pass therebetween, and a second position at which said second piston portion is associated with said second surface to separate said first and second chambers, with said liquid dose being delivered by a reduction in the volume of said second chamber.

12. The device of claim 11, wherein said first chamber is open to said second chamber when said piston member is in its first position.

13. The device of claim 11 or 12, further including a spring urging said piston member to move to its first position.

14. The device of claim 11, 12 or 13 wherein said second surface has a radius larger than said first surface.

15. The device of any one of claims 11 to 14, wherein said device is a scratch vaccine applicator having a scratch blade mounted in said body and to which said second duct means extends to deliver the vaccine to said blade.

16. A vaccine scratch applicator substantially as hereinbefore described with reference to the drawings.