SNARES

Abstract: A snare thrower for throwing a snare about the leg of an animal. The snare thrower has a housing (20) and a support arm (22) upon which it is mounted a spring (62). One end of the spring is elongate and is formed with a hook (64) which engages a snare loop (8). A tongue (40) holds the arm (60) adjacent to the support arm (22) until a trigger plate (26) is pressed whereupon the throwing arm (60) is rapidly elevated by the spring.

Description: SNARES This invention relates to snares for trapping animals. In the past it has been commonplace for steel jaw traps to be used to trap pest animals such as feral dogs and cats or fur-bearing animals. There has however been a move away from the use of such traps because they are inhumane and, in the case of use with fur-bearing animals-, they tend to injure the animal and hence damage the fur. The object of the present invention is to provide a snare thrower which in use applies a snare to the leg of an animal and does not require jaws for its opera- tion. According to the present invention there is provided a snare thrower comprising a snare throwing arm having means thereon to engage a snare, a spring, a release mechanism which in use operates to hold the arm in a set position in which energy is stored in the spring and, on release of the release mechanism the arm moves under influence of the spring to a snare throwing position in which the snare is moved upwardly. The invention will now be further described with reference to the accompanying drawings, in which: Figure 1 is a plan view of a preferred embodiment of the invention; Figure 2 is a side view of the device; Figure 3 is a partial longitudinal section through the device; Figure 4 is a cross-sectional view taken along the line 4-4; Figure 5 is a side view of the loop of the snare; Figure 6 is an end view of a snare locking brac- ket. Figure 7 is a schematic view showing the section of a snare elevating spring and post; and Figure 8 is a fragmentary plan view showing the snare elevating spring. The snare shown in the drawings comprises a snare thrower 2 for throwing a snare assembly 4. The snare assembly comprises a strand 6 of stainless steel wire rope formed into a snare loop 8 by means of a snare bracket 10 formed at one end of the strand. The other end of the strand is formed with a mounting loop 12. The loop 12 is connected to a chain 14 by means of a shackle 16. The other end of the chain is connected by means of a wire or the like to a stick or log 18. In use of the device, as explained hereinafter, the snare thrower operates to project the snare loop 8 rapidly upwards about the leg of an animal and simultaneously close the loop about the leg so that the bracket 10 prevents the loop from being removed from the animal's leg. The snare and stick 18 constitute an encumbrance to the animal and prevent it moving a significant distance from the site of the snare. The animal can then be captured in a humane manner. The snare thrower comprises a generally cylindrical housing 20 rigidly connected to a support arm 22. The housing 20 is provided with an annular platform 24 beneath which is located a trigger plate 26. The platform 24 is located from about 6 to 12 mm below the top edge of the housing so that wall portion 27 forms a protective wall against which the snare loop 8 rests. The wall portion 27 slopes to the level of platform 2 at sloping edges 29 so that the ends of the loop 8 extending towards the arm 22 are not encumbered by the wall portion 27. The plate platform 24 is provided with eight drainage holes 25. The plate 26 is of slightly larger diameter than the opening in the platform 24 so that its edge underlies the inner periphery of the platform 24. The plate 26 is carried by means of an arm 28 which includes a narrow portion 30 which extends through an opening 34 in the housing 20. The inner end of the portion 30 is connected to a bush 36 which is mounted for rotation on a bolt which passes laterally through the arm 22. Extending upwardly from the arm 28 is a post which carries a hook member 40 which co-operates with a tongue 42. The hook .member 40 may be integrally formed with the arm 28. The post 43 passes through an opening 41 formed in the platform 24. One end of the tongue 42 is connected to a bush 44 which is mounted for rotation on a pivot shaft 46. The pivot shaft 46 in turn extends between two mounting brackets 48 and 50 which extend upwardly from the arm 2.2. One end of the shaft 46 is threaded and is received in a threaded opening in the bracket 50, the other bracket, 48 including a circular opening through which the shaft may pass. The other end of the tongue 42 has a downwardly inclined end portion 52 provided with a tapering rebate 54 which receives the hook formation 40 when the snare thrower is in its set position, as seen in Figures 1 and 3. The snare thrower includes a snare throwing arm 60 and a coil spring 62. In the illustrated arrangement, the arm 60 is formed integrally as an end of the coil spring 62. The other end 63 of the spring is formed into a loop and is connected to the underside of the arm 22 by means of a mounting bolt 64. The end of the arm 22 (opposite to the housing 20) is formed with an oblique face 65 so as to facilitate access to the bolt 67 for adjustment of the location of the mounting of the spring. The free end of the arm 60 is provided with a transverse leg 61 and a hook 64 which is formed by a downwardly extending leg 66, transverse leg 68 and upturned leg 70, as best seen in Figure 4. The hook 64 in use engages the snare strand 6 between the mounting loop 12 and the snare loop 8. The trap is set by rotating the throwing arm 60 anticlockwise (as seen in Figure 2) from the position shown in chain lines to the position shown in solid lines. The tongue 42 is then rotated from the position shown in chain lines to the position shown in solid lines so that it overlies the transverse leg 61 formed at the top of the throwing arm. The plate 26 and hook 40 are then rotated clockwise (as seen in Figure 3) from the position shown in chain lines to the position shown in solid lines whereby the end of the hook, 40 engages the rebate 54 of the tongue. In this position the transverse leg is resiliently biased into engagement with the underside of the tongue 42 by the spring 62. As seen in Figures 1 and 3, the snare loop 8 is placed on the annular platform 28 adjacent to the outer periphery and the snare bracket is located on the arm 22 beneath the tongue 42. As mentioned previously, the loop 12 is mounted on the end of the shaft 46 and the adjacent ' strand 6 of the snare assembly lies in the hook 64 formed at the end of the arm 60. When a downward force is applied to the plate 26 it will rotate anticlockwise (as seen in Figure 3) whereupon the hook 40 will disengage the tongue 42 and the action of the spring 62 will cause the arm to rotate rapidly in a clockwise direction (as seen in Figures 2 and 3) . Because the snare wire is engaged in the hook 64 it will be carried out rapidly upwardly with the arm and at this stage the loop 12 will remain on the shaft 46. The snare loop 8 will of course also move upwardly at this stage. If an object, such as the leg of an animal, has caused the downward movement of the plate 26, the leg will have the snare loop 8 moved rapidly upwardly around the leg and this action causes the snare loop to close by the strand sliding through the snare bracket 10, as seen in chain lines in Figure 2. Once the snare loop has tightened, the bracket 10 prevents it from being untightened. Figures 5 and 6 show in more detail the shape of the snare bracket 10. The bracket has three generally straight legs 72, 74 and 75 and a bifurcated loop portion 78. The legs 75 and 74 are inclined at an angle of about 50° to one another and the legs 74 and 72 are inclined at about 20° relative to one another. The snare wire is provided with a swaged abutment 80 at the end opposite to the loop 12 the axis of the abutment 80 being set about 75° to the axis of the strand 6 of the snare wire. The wire passes through a hole 82 formed in the leg 75 and the abutment 80 engages one side of the leg 75. The snare wire, extending at an angle of about 75°, passes through the bifurcated loop portion 78. The wire then, forms the snare loop 8 and passes through a hole 84 formed in the terminal leg 72. The holes 82 and 84 are slightly countersunk on their inner faces i.e. the faces opposite to the abutment 80 and loop 12 so as to facilitate passing of the snare wire in the direction of arrow 90 for tightening of the snare loop but to resist movement of the snare wire in the opposite direction. It is preferred that the snare wire comprises 3.2 mm 7/19 stainless steel wire rope in which case the holes 82 and 84 are 4 mm in diameter and the gap in the bifurcated loop 78 is 4 mm wide. The bracket 10 is preferably formed from zinc anneal flat plate 1.6 mm in thickness. The snare bracket 10 has an important bearing on the successful operation of the snare thrower and snare. In order to provide for an adjustment of the amount of downward force required on the plate 26 for triggering of the snare thrower, an adjusting screw 92 is provided. It passes through the arm 22 and is threadedly received in a nut 94 fixed to the upper face of the arm 22. The end of the screw 92 bears against the underside of the tongue 42 with a force which depends upon the axial adjustment of the screw and the harder it bears against the tongue, the more force is required on the plate 26 in order for triggering to occur. The snare thrower also includes an arm support projection 96 extending upwardly from the arm 22, the height of the projection 96 being chosen so that the arm 60 engages the top of the projection when in the set position, as shown in Figures 2 and 3. This prevents unwanted triggering of the snare thrower by forces applied to the arm itself rather than to the plate 26. The snare thrower includes an elevating spring 97 and a post 99 which assist in giving the snare loop 8 a high vertical component of velocity shortly after triggering. Figure 8 shows the mounting of the spring 97 relative to the housing 20. One end of the spring is formed with a U-shaped connecting portion 101 which passes through a pair of holes in the housing 20. The spring then has a first cross portion 103 extending transversely across the housing and through an opening in its side wall. The spring then sweeps upwardly in a first curved portion 105 and then sweeps downwardly in a second curved portion 107 to a point near the bottom of the housing 20 on the other side thereof. The spring then has a second transverse portion 109 extending across the housing and terminating with a U-shaped connecting portion 111. The curved portions 105 and 107 join at a central kinked portion 113. The portion 113 is located beneath the tongue 42 in the set position of the snare thrower, illustrated in Figures 1 and 2. In the set portion energy is stored in the first and second portions 105 and 107 owing to their ' resilient deformation and in the cross-portions 103 and 109 which behave as tension springs. It will be further seen that in the set position, the snare loop 8 is located above the portions 105 and 107 of the spring. On triggering of the snare thrower the spring 97 will be released simultaneously with the throwing arm 60. The portions 105 and 107 will thus move rapidly upwardly and will impart a significant component of upward vertical movement to the loop 8. The spring 97 therefore stops the leg of the animal which has triggered the device from being pulled towards the release mechanism whereby the throwing arm 60 has a rigid object gate which to pull the snare loop tight. Further, the snare loop must rise over the highest point 113 of the spring thereby ensuring a catch well up the leg of the animal which has triggered the device. The sudden upward movement of the spring 97 also breaks soil on the platform 24 thereby allowing the snare loop 8 a clearer upward movement from the platform. The elevating post 99 is generally U-shaped and its legs pass through holes formed in the platform. The legs extend to the housing 20 and pass through opennings, where the ends 117 are bent upwardly so as to fix the post 99 in position.. It is inclined to the wall portion 27 as shown and preferably projects about 5 mm above the wall portion. In the set position, the snare loop 8 passes between the post 99 and the wall portion 27. On triggering, the snare loop is moved * rapidly upwardly and in a direction towards the arm 22 and the post 99 thus momentarily forms a solid object against which the snare loop pulls thereby assisting in tightening of the loop. Further, the inclination of the post post 99 will assist in imparting an upward vertical component of velocity to the snare loop as the throwing arm 60 continues to rise. In a prototype snare designed for snaring feral dogs, the housing 20 is about 180 mm in diameter and the inner periphery of the annular plate 24 is 100 to 110 mm in diameter. For snaring dogs it is preferred to have a minimum distance of about 40 mm between the snare loop 8 and the opening in the annular plate so that the animals paw will not press the trigger plate 26 while the paw is also roughing the snare loop 8. It follows that this distance is variable in accordance with the type of animal to be snared. The arm 22 is about 280 mm in length and the arm 60 is about 300 mm in length. The arm 60 and spring 62 are formed from 4.5 mm spring steel. The spring 62 has about 5 right hand coils and an outside diameter of 33 mm, there being no spacing between the coils thereof. The force at a point on the arm 60 35__rømfrom the centre of the spring 62 when the device is set, has been measured at 14. Nm. The arm 60 moves through an arc of about 140° from its set position to its release or rest position as shown in chain lines in Figure 2. It will be appreciated that the snare could be made larger or smaller according to the intended application of the device. In use the snare is set and positioned at a location where target animals are thought to be fo present. The snare loop 8 is laid on the platform 24 and the inner face of the housing 20 assists to define a circular shape for the loop 8 at this stage. The log 18 is connected to the loop 12 of the snare assembly by the chain 14 and shackle 16. The snare is then camouflaged by means of a light covering of soil or leaves. It will be appreciated that the pivot 38 for the plate 26 is located within the arm 22 and is thus not likely to be fouled by the camouflage material. When an animal stands on the plate 26, the release mechanism will operate and the arm 60 will cause the snare loop 8 to move rapidly upwardly and tighten on the leg of the animal. After snaring, the animal will cause the loop 12 to slide from the end of the spindle 46 whereby the animal is not tethered to the snare thrower and is constrained only by the log 18. In an alternative use the chain 14 can be passed through the arm 22 from the oblique face and then through the opening 34 in the housing for connection to the loop 12. After snaring the snare will remain connected to the snare loop and thus will be less easily lost. Many modifications will be apparent to those skilled in the art without departing from the spirit and scope of the invention.

Claims: I f CLAIMS : 1. A snare thrower (2) comprising a snare throwing arm (60) having means (64) thereon to engage a snare (4), a spring (62), a release mechanism (26, 40, 42) which in use operates to hold the arm in a set position in which energy is stored in the spring and, on release of the release mechanism the arm moves under influence of the spring to a snare throwing position in which the snare is moved upwardly. 2. A snare thrower as claimed in claim 1 including a housing (20) having a snare support surface (24) upon which a snare loop (8) of the snare is positioned in the set position and wherein the release mechanism includes a trigger phase (26) which is, in the set position, generally contiguous with the support surface and is, in use, displaced from that position by an animal in order to throw the snare. 3. A snare thrower as claimed in claim 2 including a support arm (22) which extends laterally from the housing and said spring is mounted near the free end (65) of the support arm. 4. A snare thrower as claimed in claim 3 wherein the spring comprises a coil spring (62) , one end (63) of which is mounted on the support arm and the other end is extended so as to constitute said snare throwing arm (60). 5. A snare thrower as claimed in claim 4 wherein said means to engage a snare is a hook member (64) integrally formed with the snare throwing arm. 6. A snare thrower as claimed in claim 3, 4 or 5 wherein the release mechanism includes a tongue (42) pivotally mounted on the support arm and in the set position the tongue engages a catch member (40) which is coupled for movement with the trigger plate, the tongue being engageable with the snare throwing arm so as to hold the arm in the set position against the bias of the spring and wherein, on displacement of the trigger plate, the catch member disengages the tongue which, in turn, releases the throwing arm. 7. A snare thrower as claimed in claim 6 wherein the throwing arm includes a laterally extending leg (61) which is engageable with the underside of the tongue in the set position. 8. A snare as claimed in claim 6 or 7 wherein the trigger plate is carried by a plate support member (28) which extends within the housing and is pivotally connected to the support arm, said catch member being located on a catch support post (43) which projects from the plate support member through an opening (41) therein. 9. A snare thrower as claimed in claim 8 wherein the plate support member (28) , post (43) and catch member (40) are integrally formed. 10. A snare thrower as claimed in any one of claims 6 to 9 including a release adjustment member (92) for adjusting the force required on the trigger plate in order to trigger the release mechanism, said adjustment member including a body which tends to bias the tongue into engagement with the catch member. 11. A snare thrower as claimed in claim 10 wherein the body includes a threaded shaft received within a threaded socket (94) mounted on the support arm, the shaft being engageable with the underside of the tongue. 12. A snare thrower as claimed in any one of claims 2 to 11 including a supplementary spring (97) which in a set position thereof stores energy and is held in that position by said release mechanism and on release engages the snare loop (8) and assists in moving the snare loop upwardly. 13. A snare thrower as claimed in claim 12 wherein the supplementary spring, in the set position, extends adjacent to the outer surface of the housing and is held beneath the snare by the release mechanism and, on release, rotates in a sense which is opposite to the sense of rotation of the snare throwing arm. 14. A snare thrower as claimed in claim 13 wherein the supplementary spring has first and second mounting legs (103,109) which extend through the housing and are connected thereto, the arrangement being such that the mounting legs function as torsion springs. 1 . 15. A snare thrower as claimed in any one of claims 2 to 14 including a snare guide member (99) which projects upwardly from the snare support surface and which, in use, assists to impart vertical movement to the snare loop at a location remote point of engagement of the snare throwing arm with the snare. 16. A snare thrower as claimed in any one of claims 3 to 15 including an abutment (96) on the support arm which engages the throwing arm in the set position and prevents movement of the throwing arm towards the support arm when in the set position. 17. A snare thrower as claimed in any one of claims 3 to 16 including a shaft- (26) which projects laterally from the support arm and wherein the snare is formed from a snare wire (6) having a loop (12) formed at one end thereof said loop (12) being mounted on said shaft in the set position. 18. A snare thrower as claimed in claim 17 wherein the ends of the snare wire are coupled together by a snare bracket (10) which permits the snare to tighten but resists untightening. 19. A snare thrower as claimed in claim 18 wherein the snare bracket includes a first leg (72) having a hole (84) therein through which the snare wire (6) passes, a second leg (75) having a hole (82) therein through which the snare line passes, the other end of the snare wire including an abutment (80) which cannot pass through the hole (82) in the second leg, and a bifurcated loop portion (78) adjacent to said second leg, the snare wire passing through said bifurcated loop portion.

Inventors: ROBINSON JOHN L, STEVENS PETER LINDSAY, ROBINSON, JOHN, L., STEVENS, PETER, LINDSAY
Applicants: VICTORIA STATE, THE STATE OF VICTORIA
Application year: 1986
Main classification: A01M23
IPC codes: A01M23