GB2139156A

GB2139156A - Tamper proof clasp assembly

Info

Publication number: GB2139156A
Application number: GB08411638A
Authority: GB
Inventors: Timothy Kelleher; Thomas John Benson
Original assignee: Individual
Current assignee: Individual
Priority date: 1983-05-07
Filing date: 1984-05-08
Publication date: 1984-11-07
Also published as: IE830791L; GB8411638D0

Abstract

The assembly, particularly an animal ear tag, comprises a plug 2 including an arrowhead 4 at its projecting end and a weak point 5 behind the arrowhead, and a socket 3 into which arrowhead 4 may pass having a chamber containing a resiliently deformable washer 11 freely movable axially along a part only of the axial length of the chamber. The dimensions of the washer 11 are such that the washer cannot leave the chamber and such that when the arrowhead 4 is pushed through the washer 11 and the washer subsequently reverts to its original dimension, the arrowhead 4 cannot then be withdrawn from the washer 11. <IMAGE>

Description

SPECIFICATION Tamper proof clasp assembly The present invention relates to tamper proof clasp assemblies and is particularly though not exclusively concerned with tamper proof ear tags for animals.

The invention provides a tamper proof clasp assembly for clasping two members together, the assembly comprising (1) a plug projecting from one member, the plug including an arrowhead at its projecting end and a weak point behind the arrowhead (2) a socket on the other member into which the arrowhead may pass, the socket opening out into a chamber and (3) a resiliently deformable washer housed within the chamber and freely movable axially along a part only of the axial length of the chamber, the outer dimensions of the washer being such that the washer cannot leave the chamber and the inner dimensions of the washer being less than the outer dimensions of the arrowhead; whereby when the arrowhead is pushed through the washer and the washer subsequently reverts to its original dimension, the arrowhead cannot then be withdrawn from the washer or the socket.

By arrowhead is meant a head which gradually increases in cross section and then ends in a shoulder; The invention also provides an animal ear tag comprising a strip of metal bent over into a V or U shape to define two members, the ends of which strip are provided with an assembly according to the invention.

The invention will now be described more particularly, by way of example, with reference to the accompanying drawings in which; Figure 1 is an exploded perspective view partly in section of a first plug, socket and washer arrangement; Figure2 is a sectional elevation of an alternative socket; and Figure 3 is a sectional elevation of a part only of a third socket.

Referring initially to Figure 1, the tag is made of a single strip of stainless steel bent over into a V or a U shape to define two arms 1 a, 1 b. A plug 2 is provided at the end of arm 1 a and a socket 3 at the end of arm 1 b. The plug 2 is a cylinder, and includes an arrowhead 4 and a weak point 5. The socket 3 comprises a housing which consists of a hollow cylindrical cage 6 and a cap 7. The cap 7 has a downwardly depending skirt 8 which extends into the cage 6, and a flange 9 which seats on top of the cage 6. The downwardly depending skirt 8 defines a shoulder 10 within the housing. The housing contains a split washer 11, freely movable axially within the housing, but constrained between the shoulder 10 of the cap and the bevelled shoulder 12 of the cage.To close the ear tag, the plug 2 and socket 3 are pushed together by means of a tool such as a pliers.

The arrowhead 4 of the plug 2 passes freely through the aperture 13 in the tag and through the entry aperture of the housing. The arrowhead 4 then encounters the split spring washer 11 and pushes the split spring washer 11 until the split spring washer 11 engages the shoulder 10. Further pressure causes the arrowhead 4 to push through the split spring washer 11, opening out the split spring washer 11. The arrowhead 4 then passes on into the recess 14 within the cap 7, and the washer 11 returns resiliently to its original dimensions, behind the arrowhead 4.

If an attempt is made to pull the plug 2 from the socket 3, the washer 11 will move downwardly against inclined internal shoulder 12, causing the washer 11 to tighten around the plug 2. Eventually the plug 2 will snap at the weak point 5. In the closed position (not shown) of the plug 2 and socket 3 arrangement, the weak point 5 coincides with the aperture 13 in the tag, and it is therefore not possible for a would-be tamperer to grip the plug 2 in the region between the weak point 5 and arrowhead 4.

The arrowhead 4 on the plug 2, together with the bevelling 15 on the lower internal rim of the cage 6, cooperate in guiding the plug 2 into the socket 3 so that the tag will still function even if distorted.

The arrowhead 4 also assists in reducing pain or irritation felt by the animal as the plug 2 passes through the tissue of the ear.

The plug 2, socket 3 and washer 11 are all made of stainless steel. The plug 2 is stud welded to the arm 1a;the cage6is welded to the arm 1b;thewasher11 is inserted in the cage 6; and then the cap 7 is welded in position on the cage 6.

To assist in detecting tampering, the outside of the socket is provided with a surface pattern (not shown), such as a milled surface. It would be very difficult to restore the pattern to the surface of the socket, after tampering with the clasp assembly.

The requisite animal identification code (not shown) is provided on the outer surface of arm la.

All of the code is provided on one arm to prevent the tag having to be flipped over to read part of the code, thus irritating the animal. The code also covers the stud weld for the plug 2. The arm 1 b of the tag is, however, also provided with written matter or a pattern (not shown) on the outer surface thereof to enable detection of tampering. To protect the code and other pattern or written matter, the arms 1 a, 1 b of the tag are provided with raised edge flanges 16.

Referring now to Figure 2, there is shown one arm 30 of a tag, a socket generally designated 31, and a washer 32 which is movable axially within the socket but constrained between two shoulders 33 and 34.

The second arrangement functions in the same manner as the first but differs in the construction of socket. The socket 31 comprises an outer housing 31a and an inset 31 b. Only one weld is required, between the arm 30 of the tag and the oter housing 31 a, the insert being retained in position by the arm 30 and outer housing 31a.

Referring now to Figure 3 there is shown an alternative outer housing 60 which, in conjunction with the insert of Figure 2, would form a socket for a clasp assembly according to the invention.

1. A tamper proof clasp assembly for clasping two members together, the assembly comprising (1)

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Tamper proof clasp assembly The present invention relates to tamper proof clasp assemblies and is particularly though not exclusively concerned with tamper proof ear tags for animals. The invention provides a tamper proof clasp assembly for clasping two members together, the assembly comprising (1) a plug projecting from one member, the plug including an arrowhead at its projecting end and a weak point behind the arrowhead (2) a socket on the other member into which the arrowhead may pass, the socket opening out into a chamber and (3) a resiliently deformable washer housed within the chamber and freely movable axially along a part only of the axial length of the chamber, the outer dimensions of the washer being such that the washer cannot leave the chamber and the inner dimensions of the washer being less than the outer dimensions of the arrowhead; whereby when the arrowhead is pushed through the washer and the washer subsequently reverts to its original dimension, the arrowhead cannot then be withdrawn from the washer or the socket. By arrowhead is meant a head which gradually increases in cross section and then ends in a shoulder; The invention also provides an animal ear tag comprising a strip of metal bent over into a V or U shape to define two members, the ends of which strip are provided with an assembly according to the invention. The invention will now be described more particularly, by way of example, with reference to the accompanying drawings in which; Figure 1 is an exploded perspective view partly in section of a first plug, socket and washer arrangement; Figure2 is a sectional elevation of an alternative socket; and Figure 3 is a sectional elevation of a part only of a third socket. Referring initially to Figure 1, the tag is made of a single strip of stainless steel bent over into a V or a U shape to define two arms 1 a, 1 b. A plug 2 is provided at the end of arm 1 a and a socket 3 at the end of arm 1 b. The plug 2 is a cylinder, and includes an arrowhead 4 and a weak point 5. The socket 3 comprises a housing which consists of a hollow cylindrical cage 6 and a cap 7. The cap 7 has a downwardly depending skirt 8 which extends into the cage 6, and a flange 9 which seats on top of the cage 6. The downwardly depending skirt 8 defines a shoulder 10 within the housing. The housing contains a split washer 11, freely movable axially within the housing, but constrained between the shoulder 10 of the cap and the bevelled shoulder 12 of the cage.To close the ear tag, the plug 2 and socket 3 are pushed together by means of a tool such as a pliers. The arrowhead 4 of the plug 2 passes freely through the aperture 13 in the tag and through the entry aperture of the housing. The arrowhead 4 then encounters the split spring washer 11 and pushes the split spring washer 11 until the split spring washer 11 engages the shoulder 10. Further pressure causes the arrowhead 4 to push through the split spring washer 11, opening out the split spring washer 11. The arrowhead 4 then passes on into the recess 14 within the cap 7, and the washer 11 returns resiliently to its original dimensions, behind the arrowhead 4. If an attempt is made to pull the plug 2 from the socket 3, the washer 11 will move downwardly against inclined internal shoulder 12, causing the washer 11 to tighten around the plug 2. Eventually the plug 2 will snap at the weak point 5. In the closed position (not shown) of the plug 2 and socket 3 arrangement, the weak point 5 coincides with the aperture 13 in the tag, and it is therefore not possible for a would-be tamperer to grip the plug 2 in the region between the weak point 5 and arrowhead 4. The arrowhead 4 on the plug 2, together with the bevelling 15 on the lower internal rim of the cage 6, cooperate in guiding the plug 2 into the socket 3 so that the tag will still function even if distorted. The arrowhead 4 also assists in reducing pain or irritation felt by the animal as the plug 2 passes through the tissue of the ear. The plug 2, socket 3 and washer 11 are all made of stainless steel. The plug 2 is stud welded to the arm 1a;the cage6is welded to the arm 1b;thewasher11 is inserted in the cage 6; and then the cap 7 is welded in position on the cage 6. To assist in detecting tampering, the outside of the socket is provided with a surface pattern (not shown), such as a milled surface. It would be very difficult to restore the pattern to the surface of the socket, after tampering with the clasp assembly. The requisite animal identification code (not shown) is provided on the outer surface of arm la. All of the code is provided on one arm to prevent the tag having to be flipped over to read part of the code, thus irritating the animal. The code also covers the stud weld for the plug 2. The arm 1 b of the tag is, however, also provided with written matter or a pattern (not shown) on the outer surface thereof to enable detection of tampering. To protect the code and other pattern or written matter, the arms 1 a, 1 b of the tag are provided with raised edge flanges 16. Referring now to Figure 2, there is shown one arm 30 of a tag, a socket generally designated 31, and a washer 32 which is movable axially within the socket but constrained between two shoulders 33 and 34. The second arrangement functions in the same manner as the first but differs in the construction of socket. The socket 31 comprises an outer housing 31a and an inset 31 b. Only one weld is required, between the arm 30 of the tag and the oter housing 31 a, the insert being retained in position by the arm 30 and outer housing 31a. Referring now to Figure 3 there is shown an alternative outer housing 60 which, in conjunction with the insert of Figure 2, would form a socket for a clasp assembly according to the invention. CLAIMS

1. A tamper proof clasp assembly for clasping two members together, the assembly comprising (1) a plug projecting from one member, the plug including an arrowhead at its projecting end and a weak point behind the arrowhead (2) a socket on the other member into which the arrowhead may pass, the socket opening out into a chamber and (3) a resiliently deformable washer housed within the chamber and freely movable axially along a part only of the axial length of the chamber, the outer dimensions of the washer being such that the washer cannot leave the chamber and the inner dimensions of the washer being less than the outer dimensions of the arrowhead; whereby when the arrowhead is pushed through the washer and the washer subsequently reverts to its original dimension, the arrow head cannot then be withdrawn from the washer or the socket.

2. An assembly as claimed in Claim 1, in which the washer is a split ring.

3. An assembly as claimed in Claim 2, in which all the components are of stainless steel.

4. An assembly according to any one of Claims 1 to 3, in which the weak point is so located on the plug that in the closed position of the assembly, the weak point is at the aperture of the socket.

5. An assembly according to any one of the preceding claims, in which there is provided part way along the axial length of the socket a shoulder which limits the axial movement of the washer.

6. An assembly according to any one of the preceding claims, in which a pattern is formed on the external surface of the socket.

7. An assembly according to any one of the preceding claims, in which the rim ofthe aperture is bevelled to guide the arrowhead during closure.

8. An animal ear tag comprising a strip of metal bent over into a V or U shape, the ends of which are provided with an assembly according to any preceding claim.

9. Atamper proof assembly, or an eartag including a tampered proof assembly, substantially as herein described with reference to and as shown in any of the accompanying drawings.