ANIMAL EAR TAGS

Abstract: An animal ear tag having interfitting male (5) and female (6, 21) parts for fixing the tag has a chamber (14) inside the male part (5) for receiving a cylindrical electronic responder (15, 15a), which may have a diameter of up to 3 mm and a length of up to 20 mm. The male part (5) is preferably wholly or partly formed of plastics material. An identification index encoded in the responder is also represented visually on the tag. The male and female parts are preferably mounted at opposite ends of a looped strip (1).

Description: TITLE OF THE INVENTION Animal Ear Tags BACKGROUND OF THE INVENTION a. Field of the Invention This invention relates to ear tags for animals, particularly for use in marking farm animals in disease eradication programmes or in stock control. b. Description of the Related Art Ear tags have been known for a long period. Such tags generally have a fixing device comprising male and female parts, the male part of which is inserted through an animal's ear. The male and female parts may each be attached to a separate plate or tab, or they may be joined by a looped strip. Visual identifying indicia are carried on one or both plates or one or both limbs of a strip. The ear tag of our Irish Patent No. 48,707 (E.P. 0,014,584B) has been successfully used in Government programmes for marking cattle. However there is currently a demand for electronic marking devices which can be identified by an interrogation unit. It is known to implant a coded responder in the animal (see for example EP 0,299,557 NEDAP). A responder is capable of generating an identification signal e.g. a numerical code in response to an electromagnetic interrogation field generated by a transmitter/ receiver. However an implanted responder may migrate in the animal, either as the whole responder or as fragments thereof resulting from breakage of the responder. At the time of slaughtering it is desirable that each responder is accounted for, so that misuse is prevented and the risk of migration or loss is overcome. However it is very difficult to recover all implanted responders, particularly because of the rapid movement of the animals or their carcases in a slaughter house so that there may be insufficient time to retrieve the responders. Furthermore if an implanted responder ceases to work there is no means of identifying the animal or of knowing whether or not a responder is present in the animal. It has been proposed to attach a responder to the animal by means of a collar. However such devices are cumbersome and liable to snagging on fences and the like. E.P. 0,077,707 A. Soc. Nouvelle Rockall France S.A. describes an ear tag consisting of a first plate ending in a tab which supports the male part of a fixing device, while the female part is mounted on the tab of a second plate which has a broad zone for eye-readable information and carries a semi-conductor memory circuit housed in a rectangular cavity on the exterior of the female part. A glove with contact studs is used to transfer data via a cable to a data processor. E.P. 138,723A Soc. Nouvelle Rockall France S.A. describes a hand-held reading device for reading or modifying the content of an electronic memory attached to an animal ear tag. SUMMARY OF THE INVENTION It is an object of the present invention to provide a device which combines the advantages of an electronic responder with the security of a tamper-proof ear tag. The present invention provides an ear tag having interfitting male and female parts for fixing the tag, wherein a chamber is provided inside the male part for receiving an electronic responder. Such responders are generally cylindrical in shape with a diameter of not more than 3mm, particularly 2-3mm and a length of not more than 20mm, particularly 15-20mm. Such a responder may therefore be housed very conveniently within the male part of the fixing device. In use the male part is substantially shielded against both tampering and accidental damage by the flesh of the ear which surrounds it. Preferably the male part is wholly or partly formed of plastics materials and the responder chamber is surrounded by plastics material. This facilitates interrogation of the responder, which would be inhibited if the responder were housed in a metal body. According to one aspect of the invention, an identification number which is encoded in the responder is also represented visually on the ear tag, e.g. by engraving the number and/or by means of a bar code which can be read by a bar code reader. The term "number" as used herein covers numerals, letters and other identifying indicia. According to a further aspect of the invention, the tag comprises a strip of flexible plastics material having the male part of the fixing device close to one end of the strip and the female part of the fixing device close to the other end of the strip. This is a more secure arrangement than a tag comprising 2 tabs (as in E.P. 0,077,707A) because there is a risk that one tab may slip through the hole in the animal's ear if that hole becomes enlarged, or that an unscrupulous person may roll one tab to a tubular shape and force it through the hole in the animal's ear. According to one preferred embodiment of the invention, the female part of the fixing device includes a resilient split washer which engages behind a head on the male part. Preferably the female part also includes a sleeve of hard plastics material inside a cap of softer plastics material, so that the cap protects the female part while the sleeve supports the cap and retains the split washer. Preferably the male part incorporates a metal head. Preferably also the chamber is sealed by an end cap at the base of the male part, the end cap also acting as a locator of the tag in a tool for applying the tag. The sealing of the end cap may be achieved by heat sealing, sonic welding or adhesive, or it may have a push-fit or threaded connection with the body of the male part. The term "soft plastics material" or "softer plastics materials" used herein refers generally to a plastics material having a softness and flexibility comparable to that of the plates or tabs of commercially-available ear tags, e.g. a polyurethane such as the polyeste urethane having Shore-hardness A/D (DIN 53,505) of 92/42 sold by Bayer AG under the Trade Mark DESM0PAN 590. The term "hard plastics material" or "harder plastics material" refers generally to a plastics material (most suitably a filled plastics material) having a hardness and rigidity comparable to that of the male part of commercially- available ear tags such as those sold under the Trade Mark DALT0N. While the preferred form of responder is a cylindrical responder received within the stem of the male part, an alternative embodiment of ear tag according to the invention may use a disc shaped (or other generally flat) responder housed in the base of the male part. The plastics materials used in the male part of an ear tag according to the invention should not inhibit the transmission of electromagnetic waves. Any plastics materials used in the ear tag should be bacteria resistant and resistant to ultra violet light, as is known to those skilled in the art. BRIEF DESCRIPTION OF THE DRAWINGS Various embodiments of the invention are illustrated in the accompanying drawings in which Figure 1 is an isometric view of the first embodiment of an ear tag in unfolded position; Figure 2 is an enlarged isometric view of the male part of the fixing device in the embodiment of Figure 1; Figure 3 is a vertical cross section of the male part shown in Figure 2; Figure 4 is a vertical cross section of the fixing device in a second embodiment, shown in the closed position of the tag; Figure 5 is a vertical cross section of a third embodiment of an ear tag, shown in the closed position; Figure 6 is an isometric view of portions of the female part of the fixing device in the embodiment of Figure 5; Figure 7 is a vertical cross section of the fixing device in a fourth embodiment, shown in the closed position; Figure 8 is a horizontal cross section of the fixing device on the l ne A-A in Figure 7; Figure 9 is a projection of the entire tag of the fourth embodiment, shown in the closed position; Figure 10 is a vertical cross section of the fixing device in a fifth embodiment, shown in the closed position. DESCRIPTION OF THE PREFERRED EMBODIMENTS As shown in Figures 1-3, a tamper-proof ear tag comprises a strip 1 of flexible plastics material which has a waisted portion 2 at the middle to facilitate folding of the strip into a loop having two limbs 3 and 4. The fixing device comprises a male part 5 mounted at the free end of one limb 3 and a female part defining a receiver hole 6 at the free end of the other limb 4. The receiver hole in this embodiment is elliptically shaped. A number and/or bar code is engraved or printed on the outer surface of one or both limbs i.e. on the surface which is not seen in Figure 1. The male part 5 comprises a metal arrow 7 (preferably of brass) mounted into a body 8 of hard plastics material; for example the body 8 may be injection moulded around the metal arrow 7. The body 8 is elliptical in horizontal cross section. The arrow 7 has an enlarged conical head 9 which is exposed at surface 10. The body 8 also has an enlarged head portion 11 with a sharp ridge 12. The stem 13 of the body 8 is hollow and defines a cylindrical chamber 14 to receive an electronic responder 15 of known type. The base portion of the stem is widened out to form a skirt 16 which provides stability for the male part 5 on the flexible plastic strip 1. The body is seated in a hole in the limb 3. An end cap 17 having approximately the same diameter as the skirt 16 is sealed into the base of the body in such a manner that the end cap 17 and the skirt 16 are seated firmly on either face of the limb 3. The sealing of the end cap to the body may be achieved by heat sealing, sonic welding, adhesive or the like. In the case of an adhesive, it is preferred to use a solvent- based adhesive which primes or etches the surface of the plastics material on one or both of the components to be sealed together. The responder 15 is inserted into the chamber 14 before the end cap 17 is applied. After sealing of the end cap, the responder 15 is inaccessible. As shown in Figure 3, the metal arrow 7 may have a hollow portion 18 to receive a pin on a suitable applicator tool of known type. In use, the strip is held in folded position in the applicator tool (as in our earlier European Patent No. 0,014,584) and the head 9/11 is driven through an animal's ear. The head 9/11 then enters the receiver hole 6 which expands to permit the head to pass through and then closes around the stem 13 to retain the tag in position on the ear. The responder inside the male part is likely to break if an attempt is made to force the tag open. However it is protected against breakage in normal use because it is sheltered within the male part. Figure 4 shows a second embodiment of the invention. The same reference numerals are used for similar parts. In this embodiment, there is no metal arrow 7. The male part 5 is an integrally moulded body 19 of hard plastics materials with a conical head 20. The head is received in a round receiver hole 21 in limb 4, the receiver hole being surrounded by an annular rim 22. The body flares downwardly so that the base portion 24 of the stem is of substantially greater diameter than the neck portion 23. This widened base portion 24 provides stability in the same manner as the skirt 16 in the first embodiment. The body is retained in the hole in limb 3 b means of end cap 17 which is sealed into position as described above. The chamber 14 for the responder 15 in this embodiment lies on th axis of the male part 5. It is sealed into position by the end cap 17. This embodiment also is resistant to tampering which would permi re-use of the tag. Figures 5 and 6 show a third embodiment of the invention which i similar to that of Figure 4 but with additional features at the femal part of the fixing device. The region of the receiver hole 21 is enclosed (on the side remote from the male part 5) by a frusto-conical protective cap 25 formed of the same relatively soft plastics material as the strip 1. The cap 25 is co-axial with the receiver hole 20. Inside the cap 25, there is located a domed split washer 26 of resilient material, preferably plastics material, which is similar to a "speed-clip" as described in our Irish Patent No. 48,707 (E.P. 0,014,584). The split washer surrounds the receiver hole 20 and has its central aperture 27 aligned with the receiver hole. The aperture 27 is of smaller internal diameter than the external diameter of the neck portion 23 of the male part. The split washer is retained in position by a frusto-conical sleeve 28 of hard plastics material which lies inside the side wall of the cap 25 and supports the cap during insertion of the male part 5. The cap 25 is moulded or heat sealed into position after the split washer 26 and sleeve 28 have been installed. When the tag is being applied, by use of an applicator of known type, the head 20 passes through the animal's ear and then through the receiver hole 21; it is then forced through the aperture 27 in the split washer 26, which flexes upwardly i.e. in the direction of movement of the male part. After the head has passed through, the split washer snaps inwardly and embraces the neck portion 23 of the male part 5 below the head 20. In the closed position, the head 20 is trapped by the split washer 26 and is likely to break off if an attempt is made to force the ear tag open. The head and split washer are enclosed within the cap 25. Thus the ear tag is resistant to tampering. It will be noted in Figure 5 that the end cap 17 is of greater diameter than the base portion 21 of the body 19, for added stability. This end cap acts as a locator of the tag in the correct position in the applicator. In an alternative embodiment the cap 25 and the sleeve 28 may be cyl ndrical. The strip 1 carries a number and/or bar code on the outer surface of one or both limbs as described above for the first embodiment. Figures 7-9 show a fourth embodiment in which the male part 5 of the fixing device comprises a stem 30 of plastics material and a head portion 31 of metal e.g. brass or another metal such as an aluminium alloy or iron coated with brass. As shown in the drawings, the stem 30 comprises an outer sleeve 32 of soft plastics material formed integrally with the looped strip 33 and an inner tube 34 of relatively hard and rigid plastics material which is housed within the outer sleeve 32 except at the top where the inner tube 34 has a collar 35 extending to form the outer surface of the stem 30. The interfitting surfaces of the outer sleeve 32 and the inner tube 34 are provided with key formations 36 which may be of any suitable shape to facilitate moulding together of the hard plastics material of the inner tube 34 and the soft plastics material of the outer sleeve 32 and to avoid separation of them from one another. The head portion 31 comprises a conical head 37, a neck 38 of reduced diameter and a shoulder 39 which interfits with a protrusion 39a on the top of the inner tube 34, preferably by means of a screw thread connection as shown in the drawings or alternatively by a moulded or push fit connection. In the case of a moulded connection formed by moulding the inner tube 34 in contact with the metal head portion 31, the shoulder 39 may be perforated or keyed so that the plastics material flows into intimate engagement with the shoulder 39. The lower end of the stem 30 is completed by an end cap 40 of hard plastics material having the same diameter as the lower region of the outer sleeve 32. Due to the integral moulding of the outer sleeve 32 and the strip 33, there is no overhanging portion of the strip beyond the stem 30 and end cap 40. This reduces the risk of snagging the tag on wire fences and the like, leading to swivelling of the tag is such a way that the male part is pushed out of the hole in the animal's ear. The stem 30, head portion 31 and end cap 40 define a cylindrical chamber 14 to receive the electronic responder 15a. The chamber 14 has domed ends. The responder 15a is housed within a container structure of hard plastics material and metal. A space is left around the responder 15a and particularly at the top end thereof, in order to allow for possible deformation of the plastics material during application of the tag to an ear. In alternative embodiments, the chamber 14 may be contained within the stem 30 alone, within the stem and head portion 31, or within the stem and end cap 40. As shown in the drawings, the responder 15a is of the type supplied commercially by NEDAP N.V. of NL-7140 Groenlo, The Netherlands. The responder comprises a microchip code circuit 41, and a coil 42 wound on a ferrite rod 43, all housed within a glass tube 44. The responder is inserted into the chamber 14 before the end cap 40 is applied. After sealing of the end cap 40 to the stem 30, e.g. by sonic welding or adhesive attachment as described above, the responder 15a is inaccessible. There are no steps or hard edges on the stem which could be a cause of necrosis in the animal's ear. At the female part of the fixing device, the receiver hole 21 is enclosed by a frusto conical protective cap 45 moulded integrally with the looped strip 33. The cap 45 is coaxial with the receiver hole 21. Inside the cap 45 there is located a domed split washer or "speed clip" 26 of resilient material, suitably metal, as already described above with reference to Figures 5 and 6. Other forms of annular non-return clip or split collar may also be used. The washer or clip has its perimeter embedded in the plastics material of the cap 45 and/or strip 33, most suitably by moulding the plastics material around the washer or clip in situ. The cap 45 is penetrated by a series of vent passages 46 to allow air and/or flesh to escape from inside the cap when the tag is being applied. The tag is applied in the same manner as described with reference to Figures 5 and 6. The end cap 40 is received in a recess in the applicator tool and serves to locate the tag in the tool. Figure 9 shows the looped strip 33 which is preferred. The strip, like that of Figure 1 has a waisted portion 2 at which the strip is folded into a loop having two limbs 3 and 4. A number and/or bar code corresponding to the code generated by the responder will be engraved or printed on the outer surface of one or both limbs, but this is not shown in Figure 9. The strip of soft plastics material may be moulded in a pre-folded configuration, leaving sufficient clearance between the upper limb 4 and the top of the head 37 to allow an animal's ear to be inserted therebetween before the tag is closed. In an alternative embodiment, the strip may be formed of metal, like the tags of EP 0,014,584B. In a further alternative embodiment, the strip may be replaced by two plates, e.g. of soft plastics material, as in EP 0,077,707A. However a closed looped strip is preferred because it cannot be removed from the ear without forcing the tag open (and thereby damaging it so that it cannot be re-used). Figure 10 shows a fifth embodiment which is generally similar to that of Figures 7-9 but which has an alternative arrangement in the stem. The inner tube 34 and end cap 40 of the fourth embodiment are replaced by a housing 50 made of a similar relatively hard and rigid plastics material and whose upper body portion 51 is similar to that of the inner tube 34 but which extends downwardly in a relatively thin walled cylindrical portion 52 closed at the bottom by a dome portion 53. The housing 50 is secured inside the outer sleeve 32, as in the fourth embodiment. However an annular recess 54, is defined between the thin walled cylindrical portion of the housing 50 and the lower part of the outer sleeve 32. This recess receives a projecting tubular portion of an applicator tool (not shown), locating the tag in the applicator tool and allowing the force of the tool to be applied directly to the upper body portion 51 of the housing 50. The chamber 14 is defined by the housing 50 and head portion 31a, and the responder 15a must be inserted before the housing 50 and head portion 31a are assembled together, so that a moulded connection between the housing and head portion is not suitable in this embodiment. In the above description, the terms "up", "down", "upper", "lower" and the like refer to the ear tag as disposed in the drawings, particularly Figures 3, 4, 5, 7 and 10. In use, the tag would be applied through part of an animal's ear with the male part generally -n- horizontal and the female part at the inner face of the ear.

Claims: CLAIMS 1. An ear tag having interfitting male (5) and female (6, 21) parts for fixing the tag, characterised in that a chamber (14) is provided inside the male part (5) for receiving an electronic responder (15, 15a). 2. An ear tag according to Claim 1 wherein the chamber (14) is cylindrical. 3. An ear tag according to Claim 2 wherein the chamber (14) is adapted to house a responder (15, 15a) which is generally cylindrical in shape with a diameter of not more than 3mm and a length of not more than 20mm. 4. An ear tag according to Claim 1 having a responder (15, 15a) sealed inside the chamber (14) in the male part (5). 5. An ear tag according to Claim 1 wherein the male part (5) is wholly or partly formed of plastics materials. 6. An ear tag according to Claim 4 wherein an identification index which is encoded in the responder (14) is also represented visually on the tag. 7. An ear tag according to Claim 1 which further comprises a strip (1) of flexible plastics material having the male part (5) of the fixing device close to one end of the strip and the female part (6, 21) of the fixing device close to the other end of the strip. 8. An ear tag according to Claim 1 wherein the female part of the fixing device includes a resilient split washer clip (26) which engages behind a head (20, 31, 31a) on the male part (5). 9. An ear tag according to Claim 5 wherein the male part incorporates a metal head (10, 20, 31, 31a). 10. An ear tag according to Claim 1 wherein the chamber (14) is sealed by an end cap (17, 40) at the base of the male part (5), this end cap (17, 40) also serving as a locator of the tag in a tool for applying the tag to an animal's ear.

Inventors: KILROY MICHAEL MAXWELL, KILROY, MICHAEL, MAXWELL
Applicants: KILROY MICHAEL MAXWELL, STAFFORD KATHERINE MANHEIM, STAFFORD RODNEY ARTHUR, KILROY, MICHAEL, MAXWELL, STAFFORD, KATHERINE, MANHEIM, STAFFORD, RODNEY, ARTHUR
Application year: 1991
Main classification: G09F3
IPC codes: A01K11, G09F3