GB2565808A

GB2565808A - Trap

Info

Publication number: GB2565808A
Application number: GB1713562.5A
Authority: GB
Inventors: Elliot Darryl
Original assignee: Individual
Current assignee: Individual
Priority date: 2017-08-23
Filing date: 2017-08-23
Publication date: 2019-02-27
Also published as: GB201713562D0

Abstract

A trap 1 for small animals comprising a chassis 2 with a treadle plate 8 connected via a hinge 5 to a first edge 9b of a spring loadable strike arm 6, where the second edge of the strike arm is held away from the treadle plate by releasable engagement with a first end 16 of a trigger arm 14, and the strike arm is biased by a spring to close onto the treadle plate. The weight of a small animal depressing the treadle pate about the hinge releases the trigger arm to pivot upwards to release the strike arm to close. There may be an internal baffle [38, figure 2] part way along the treadle plate in the direction parallel to the hinge, and extending across the treadle plate from the hinge edge towards an opposite and distal second edge, where the strike arm is provided with a passage through which the internal baffle passes in use of the trap.

Description

Trap

Field of the Invention

The invention is directed to the provision of a trap for humane killing of small animal pests such as stoats, weasels, squirrels, and the like.

Background to the Invention

A variety of traps have been employed to aid in controlling the population of small animals where their numbers are considered excessive.

An overpopulation, in some locations a non-native population, of stoats, weasels, squirrels, and the like can result in substantial losses of valued and/or rare, even endangered animals. Producing and conserving populations of ground nesting game or rare birds is difficult where animals such as stoats are overabundant.

The use of traps to control small animal populations is often subject to government control (licensing procedures) as care is required to despatch animals as humanely as possible and avoid destruction of non-target species.

In many territories such as the UK, traps for control of stoats and the like are only permitted when the trap design is licensed and a prescribed method of use is followed.

Some previously approved traps are subject to scrutiny or even withdrawal of licence; due to uncertainty in achieving consistently humane destruction of target species.

Accordingly there is a need for improved traps.

Description of the invention

According to a first aspect the present invention provides a trap for small animals, the trap comprising a chassis mounting:

a treadle plate and a spring loadable strike arm, connected one to the other by a hinge between adjacent first edges;

wherein, when the strike arm is in a spring loaded position;

a second edge of the strike arm, opposite to and distal to the hinge, is held away from the treadle plate by releasable engagement with a first end of a trigger arm, and the strike arm is urged by a spring to close onto the treadle plate; and wherein the first end of the trigger arm pivots above the second edge of the strike arm and said trigger arm extends to a second end at a second edge of the treadle plate opposite to and distal to the hinge; and wherein the second end of the trigger arm engages releasably with the second edge of the treadle plate, whereby the weight of a small animal depressing the treadle plate about the hinge releases the trigger arm to pivot upwards thereby releasing the strike arm to close.

In the spring loaded position the treadle plate is typically generally horizontal and the strike arm upstanding from the hinge. In the spring loaded position the strike arm may be substantially vertical. This provides approximately a quarter circle rotation about the hinge from the spring loaded (open) position, to a closed position where the strike arm is closed onto, or at least nearer to, the treadle plate (and onto any small animal trapped in between). Normally the trap will be provided with at least one safety catch, operable to keep the strike arm from releasing accidentally when spring loaded.

Animals are directed to pass through the trap, across the treadle plate in a direction generally parallel to the hinge, until the trigger arm releases. This can be achieved in a number of ways as discussed further hereafter. Thus the trap of the invention is a so called “run through” trap.

The treadle plate may be generally rectangular in form. The opposed hinge edge and second edge may be the longer edges of the rectangle. The strike arm may have a generally rectangular form, and may be of comparable size and general shape as the treadle plate, so as to be capable of trapping a small animal on any or substantially any part of the treadle plate. However, as discussed further hereafter the strike force imparted by the strike arm is greater towards the second edge of the treadle plate; and so a baffle or baffles may be provided to direct animals passing through the trap to pass across the treadle plate nearer the second edge, leading to a rapid, humane, despatch of the animal.

With agile animals such as stoats there is a risk that the animal may jump across the treadle plate when passing through. This may occur even when the trap is provided in a tunnel and/or has baffle arrangements at either end of the treadle plate. This jumping across the treadle plate can lead to a failure to trap the animal efficiently between the treadle plate and the strike arm. The provision of an internal baffle part way, for example about half way along the treadle plate (in the direction parallel to the hinge), has been shown in testing to be effective in restricting jumping.

The internal baffle may extend across the treadle plate from the hinge edge towards the second edge. The internal baffle may be an upstanding plate, such as a metal plate, extending across the treadle plate from the hinge edge towards the second edge. The internal baffle may block passage for an animal moving across the treadle plate except through an aperture, advantageously located towards the second edge. As the internal baffle extends across the treadle plate it could interfere with the action of a strike arm coming down towards the treadle plate. Therefore the strike arm may be provided with a passage such as a slot through which the internal baffle (if fitted) passes in use of the trap.

More than one internal baffle may be fitted, for example two. The two baffles may each provide an aperture for passage of an animal. The baffles may be offset so as to cause an animal to deviate from a straight line passage across the treadle plate. For example apertures in baffles can be offset. This can have the benefit of slowing an animal down, aiding in ensuring successful operation of the trap.

Other types of internal baffle can include an upstanding portion of a mesh, or one or more rods or bars (upstanding or transverse e.g. horizontal). Also contemplated is an internal baffle of one or more, typically a plurality, of plates upstanding in orientation and with edges facing the intended direction of an animal entering the trap. The plates may be relatively thin e.g. 2-3mm thickness. As the plates are ‘edge on’ they may be initially less visible to an animal entering the trap at speed, causing a rapid slowing when the animal realises their presence.

The internal baffle may be fixed to the chassis of the trap or may be fixed to the treadle plate.

The trigger arm according to the first aspect pivots at the first end above the second edge of the strike arm. Typically the trigger arm pivots about a pivot point on a part of the chassis that is above the second edge of the strike arm.

A convenient arrangement is to have a short post projecting upwards from the first end of the trigger arm passing up through an aperture in a plate portion of the chassis that extends generally horizontally. The post can be held captively in the aperture, for example by having an end above the aperture that is larger than the aperture. A generally loose fit in the aperture allows an upwards pivoting motion of the trigger arm to allow consequent release of the strike arm; and can also allow some limited lateral and/or rotational motion of the trigger arm about a substantially vertical axis.

Such allowed motions can make it easier to set and adjust the trap. Excessive or unwanted motion in the strike arm can be avoided by arrangements to restrict the motion at or near the pivot. For example a part of the post below the aperture may be shaped to have a larger diameter than the aperture, acting to restrict upwards motion on release of the strike arm. For further example the extreme first end of the trigger arm may extend away from the post and pass through a slot in the chassis. The upper edge of the slot can act to prevent upwards motion or ‘float’ of the first end of the trigger arm that could lead to less reliable and less consistent setting of the trap. The lower edge of the slot may aid in keeping the trigger arm in position so that the trap can easily be set.

The first end of the trigger arm releasably engages the strike arm when in the spring loaded position. Conveniently this releasable engagement is by the provision of a sear or catch on an under surface of the trigger arm that catches on the strike arm at or near the second edge. This catching action is released only when the second end of the trigger arm is released from the second edge of the treadle plate.

The trigger arm may be in the form of an elongate strip of sheet metal. In which case the sear or catch at the first end for engaging with the strike arm may be formed as a bend in the sheet metal, forming a crease running from side to side across it. Other forms of trigger arm can be employed, for example a rod or bar of metal.

The second end of the trigger arm releasably engages the second edge of the treadle plate when in the spring loaded position. This may be achieved in various ways. Conveniently the second edge of the treadle plate may be upturned to form a lip at least where the trigger arm engages. The second end of the trigger arm fits inside and pushes outwards against this lip, holding the trigger arm in place until the weight of a small animal displaces the treadle plate downwards. Alternatively the engagement between the treadle plate and the second end of the trigger arm may be via a roller mounted either on the second end of the trigger arm or on the treadle plate. The roller rotates about an axis substantially parallel to the hinge. The roller can reduce friction between the trigger arm and the treadle plate and hence may improve reliability of action.

The trigger arm extends from the pivot at the first end, above the second edge of the strike arm, to a second end at the second edge of the treadle plate distal to the hinge. Conveniently the trigger arm may be located at or towards the middle (as determined along the direction parallel to the hinge) of the treadle plate. Conveniently the strike arm may be generally arcuate along its length from the first to the second end. The arcuate shape of the trigger arm may generally follow the arc described by the second edge of the strike arm. With such an arrangement the arcuate trigger arm is clear of the path, generally parallel to the hinge that is followed by animals crossing the treadle plate. An arcuate trigger arm also can have the advantage that bending to a more or less curved shape can be used to adjust the sensitivity of the trap. The arcuate shape provides a spring type action with the second end pushing outwards against the engagement point with the treadle plate.

The spring employed to spring load the strike arm may take different forms. Conveniently the spring comprises one or more coiled torsional springs wrapped around a spindle (pin) of the hinge and acting to generate spring force between the chassis and the strike arm. A spring of suitable strength to move the strike arm with sufficient speed and crushing force can readily be selected for a given size of trap.

The strike arm may be provided with a plurality of ribs with long edges directed towards the treadle plate i.e. directed towards an animal passing though the trap in use. The ribs are for providing striking contact to animals passing through the trap. Oher forms of projection, such as an array of knobs may be provided instead of or as well as ribs. The ribs, or other projections, concentrate the force from the strike arm to aid in providing an assurance of fatality. The ribs may run generally transverse to the direction of travel of an animal through the trap. Conveniently a strike arm with a plurality of ribs may be formed from a sheet of metal cut and folded to provide a slotted strike arm and ribs with edges directed towards the treadle plate as described hereafter and with reference to specific embodiments.

The use of an internal baffle as discussed above can be advantageous with other trap arrangements featuring different trigger mechanisms.

Thus according to a second aspect the present invention provides a trap for small animals, the trap comprising a chassis mounting:

an internal baffle, part way along the treadle plate in the direction parallel to the hinge, and extending across the treadle plate from the hinge edge towards an opposite and distal second edge;

wherein the strike arm is provided with a passage through which the internal baffle passes in use of the trap; and wherein, when the strike arm is in a spring loaded position;

a second edge of the strike arm, opposite to and distal to the hinge, is held away from the treadle plate by releasable engagement with a trigger arm, and the strike arm is urged by a spring to close onto the treadle plate;

whereby the weight of a small animal depressing the treadle plate about the hinge releases the trigger arm, thereby releasing the strike arm to close.

The trap according to the second aspect can have an internal baffle arrangement of the same form as discussed above with respect to the first aspect of the invention. For example, an upstanding plate of sheet metal. The trap according to the second aspect of the invention may have the same trigger arm arrangements as discussed above with respect to the first aspect, or it may have other trigger arm arrangements such as are known in the art. More generally a trap according to the second aspect may be provided with any of the features described herein in respect of the first aspect of the invention.

For reliable and humane use, the traps according to either aspect of the invention may be fitted in an enclosure in use. An enclosure may be a legal requirement. As with prior art run through traps a separate enclosure such as a cage, tunnel or pipe may be employed. Conveniently a trap of the invention may include an enclosure. The chassis may be the enclosure or the enclosure may be attached to the chassis.

The enclosure may be an open cage like structure or may be of sheet metal. For example the chassis may be a cage and/or sheet metal container for the treadle plate, strike arm and associated mechanism.

The enclosure may include one or more walls with apertures e.g. at opposed ends of the treadle plate, whereby animals are directed to pass through the trap, across the treadle plate in a direction generally parallel to the hinge, until the trigger arm releases.

These walls constitute baffles. They may be provided even where the trap is not supplied with an enclosure. A baffle may be attached to or be a part of the chassis. A wall may be of a sheet or a mesh or a barred construction.

The aperture of a baffle may be located so as to direct an animal across the treadle plate general parallel to, but away from, the hinge i.e. nearer the second edge of the treadle plate. Where more than one baffle is provided, apertures may be offset to direct an animal to deviate from a straight line passage. Where an internal baffle is fitted, a baffle in the form of a wall at an end of the treadle plate may have an aperture that is offset from the passage dictated by the internal baffle, again directing a deviation from a straight line passage.

The traps of the invention are suitable for trapping small animals such as stoats, weasels and squirrels. The size of the components employed in a trap can be adjusted to suit the target species.

Brief Description of the Drawings

Figure 1A shows in schematic perspective the operative component parts of a trap;

Figure 1B shows in schematic perspective a chassis for mounting the parts shown in figure 1A;

Figure 2 shows an end elevation of the trap of figures 1A, 1B;

Figures 3 and 4 show front elevation views of the trap;

Figure 5 shows a detail of a trigger mechanism;

Figure 6 shows baffle plates in end elevation; and

Figure 7 shows a safety catch in end elevation.

Detailed Description of some Embodiments with Reference to the Drawings

Figure 1A shows in schematic perspective the operative component parts of a trap 1 having a sheet metal chassis 2 (figure 1B). The chassis 2 is a generally box like structure that mounts the components of the trap shown in figure 1 A. The combination, to provide the trap 1, can be seen in the end elevation figure 2 and front elevations figures 3 to 5 as discussed below.

An operating lever for a safety catch 3 can be seen at one end of the chassis 2 in figure 1B. Figure 1B also shows arcuate guards 4a, 4b at either side of the chassis 2, to protect the internal mechanism (figure 1 A). The guards can also be seen in figures 2, 7 but are otherwise not shown in the figures. Also visible in the 1B view, but not shown elsewhere, are end plates 62, 64, leaving offset apertures 66, 68 for the passage of an animal.

The trap 1 is shown in the set (spring loaded) condition in figure 1A and figures 2 to 4. A hinge 5 connects strike arm 6 (generally rectangular in form) to rectangular treadle plate 8 along adjacent first edges 9a, 9b. The hinge 5 includes hinge pin 10 with springs 12 wrapped around it (figure 3). Spring ends 13a and 13b press on chassis 2 and strike arm 6. Thus the strike arm 6 is being urged towards the treadle plate 8 as suggested by arrow X.

Arcuate trigger arm 14 is positioned half way along treadle plate 8 (along direction of hinge 5, figure 3). The trigger arm 14 is a strip of sheet metal having a first end 16 including a sear 18 in the form of crease that engages the top (second) edge 20 of strike arm 6. Also at first end 16 of trigger arm 14 is a pivot 22 formed by pivot post 24 passing up through aperture 26 in a plate of chassis 2. First end 16 has an extreme end 28 passing through slot 30 in a back plate of chassis 2 as discussed in more detail below and with reference to figure 5.

Sear 18 is preventing release of strike arm 6 in direction X as trigger arm 14 is constrained from pivoting upwards about pivot 22 (direction Y). This constraint is achieved as trigger arm 14 extends to second end 32 which engages with lip 34 at second edge 36 of treadle plate 8. The force of strike arm second edge 20 against sear 18 produces a resultant force suggested by arrow Z, urging second end 32 against lip 34. Thus the trigger arm 14 is acting as a restraint which will release when a sufficient downwards force, as suggested by arrow A, is applied to the treadle plate 8 by an animal passing over it. When released trigger arm 14 springs up in direction Y and strike arm 6 descend in direction X to trap and kill an animal passing across the treadle plate 8.

Optionally a small roller (not shown) may be located at the position of lip 34 or at the second end 32 of trigger arm 14. The roller rotates about an axis substantially parallel to the direction of hinge pin 10, providing a smooth releasable contact between trigger arm 14 and treadle plate 8.

Also visible in figures 2 and 4 but not shown in figure 1A is an internal baffle 38 in the form of an upstanding metal plate fixed by rivets 40 to the treadle plate 8. The baffle 38 has an aperture 42 in the form of a cut out at the edge nearest the second edge 36 of treadle plate 8. Internal baffle 38 acts to prevent an animal jumping across treadle plate 8 and directs the passage of an animal from one side 44 or the other side 46 of the treadle plate 8; nearer the second edge 36 where the speed and hence the force of the descending strike arm 6 will be greatest. Internal baffle 38 need not be fixed to the treadle plate 8 but could, for example be fixed to a back plate of the chassis 2.

The internal baffle 38 is not visible in figure 3 as it is obscured by trigger arm 14. In figure 4 the same view is shown but without the trigger arm. Here the internal baffle 38 is visible “end on” and an aperture 48 in the sheet metal of strike arm 6 is also visible. This aperture 48 allows the internal baffle 38 to pass through without hindrance.

The force applied by the strike arm 6 is concentrated by the provision of ribs 50. In this example the strike arm 6 has been manufactured from a single sheet of metal by cutting and bending. Ribs 50 are formed by flaps bent at right angles to the general plane of the sheet, giving a strike arm having an array of ribs 50 with long edges directed towards the treadle plate. Edges 52 of the strike arm are similarly formed by bending portions of metal sheet out of the general plane. When viewed as in figure 4 the strike arm has alternating portions of metal sheet 54 and apertures 56, between ribs 50.

Figure 5 shows in schematic detail first end 16 of trigger arm 14. Slot 30 locates extreme end 28 of the first end 16 of the trigger arm 14. The top edge of the slot 58 prevents upwards float of extreme end 28 aiding in the catching action of sear 18 to top (second) edge of strike arm 6. Slot top edge 58 has been found useful in ensuring reliable engagement between sear 18 and the strike arm 6. The larger diameter portion 60 of post 24 has been found useful in preventing excessive upwards action of trigger arm 14 on release.

As well as, or instead of, internal baffle 38 - baffles may be provided at either end 44, 46 of the treadle plate 8. The chassis 2 of figure 1B includes end plates 62, 64 as baffles, leaving offset apertures 66, 68 for the passage of an animal. End elevation figure 6 shows another example where trap 1 has end plates or walls 62, 64 with circular apertures 66, 68 to direct the entrance of an animal. In this example the apertures are offset with the intent of slowing an animal down. In other examples the apertures may not be offset. Apertures in baffles may be defined by a cut out at an edge in a similar way to that shown for internal baffle 38 on figure 2. Where an internal baffle is used the apertures in other baffles employed may be offset from the passageway afforded by the internal baffle.

Figure 7 is a schematic end elevation of a trap 1 (showing only some parts) to illustrate the operation of a particularly convenient safety catch 3, when considered together with figure 3.

Safety catch 3 is fitted to a side plate 70 of chassis 2. The catch 3 is in the form of a portion of sheet metal 72 (figure 3) bent at right angles to include a hook portion 74. The portion of sheet metal 72 is mounted for rotation about bolt 76 which can be raised in slot 78 (figure 7) by raising handle 80 in direction R. Handle 80 passes through slot 82. The portion of sheet metal 72 can then rotate in the locking direction L until it passes the top edge 20 of strike arm 6 (only part shown in figure 7). Locking is complete when the handle 80 reaches end 84 of slot 82. Hook portion 74 then prevents motion X of the strike arm (figure 2) until such time as handle 80 is moved from end 84 of the slot 82.

The trap shown in these figures may typically be operated within an enclosure, or the 5 chassis may include a covering that constitutes an enclosure.

The dimensions of a trap can be adjusted to suit target species. A trap for a stoat may have, for example a treadle plate 8 of about say 200mm length x 130mm width. The strike arm 6 of about the same size. The strike arm is typically slightly smaller; say 10 about 197mm length x 122mm width measured from the hinge pin 10. Ribs 50 may be spaced at say 18 to 20mm apart and made of metal sheet of say 2-3mm thickness. Other dimensions of trap may be successfully used against stoats.

Claims

CLAIMS:

1. A trap for small animals, the trap comprising a chassis mounting:

wherein, when the strike arm is in a spring loaded position;

2. The trap according to claim 1 wherein the treadle plate is generally horizontal and the strike arm upstanding from the hinge when the strike arm is in a spring loaded position.

3. The trap according to claim 1 or claim 2 wherein the treadle plate and the strike arm have a generally rectangular form,

4. The trap according to any preceding claim further comprising a baffle.

5. The trap according to claim 4 wherein the baffle is an internal baffle part way along the treadle plate in the direction parallel to the hinge.

6. The trap according to claim 5 wherein the internal baffle is half way along the treadle plate in the direction parallel to the hinge.

7. The trap according to claim 5 or 6 wherein the internal baffle extends across the treadle plate from the hinge edge towards the second edge.

8. The trap according to claim 7 wherein the internal baffle is an upstanding plate, extending across the treadle plate from the hinge edge towards the second edge.

9. The trap according to claim 8 wherein the internal baffle blocks passage for an animal moving across the treadle plate except through an aperture located towards the second edge of the treadle plate.

10. The trap according to any one of claims 5 to 9 wherein the strike arm is provided with a passage through which the internal baffle passes, in use.

11. The trap according to any preceding claim wherein the trigger arm pivots about a pivot point on a part of the chassis that is above the second edge of the strike arm.

12. The trap according to claim 11 wherein a short post projecting upwards from the first end of the trigger arm passes up through an aperture in a plate portion of the chassis that extends generally horizontally.

13. The trap according to claim 12 wherein a part of the post below the aperture is shaped to have a larger diameter than the aperture, acting to restrict upwards motion of the trigger arm on release of the strike arm.

14. The trap according to claim 12 or claim 13 wherein the extreme first end of the trigger arm extends away from the post and passes through a slot in the chassis.

15. The trap according to any preceding claim wherein releasable engagement between the trigger arm and the strike arm is by the provision of a sear or catch on an under surface of the trigger arm that catches on the strike arm at or near the second edge.

16. The trap according to any preceding claim wherein the trigger arm is in the form of an elongate strip of sheet metal.

17. The trap according to any preceding claim wherein the second edge of the treadle plate is upturned to form a lip at least where the trigger arm engages, whereby the second end of the trigger arm fits inside and pushes outwards against the lip.

18. The trap according to any one of claims 1 to 16 wherein the engagement between the treadle plate and the second end of the trigger arm is via a roller mounted either on the second end of the trigger arm or on the treadle plate.

19. The trap according to any preceding claim wherein the trigger arm is located at or towards the middle of the treadle plate, as determined along the direction parallel to the hinge.

20. The trap according to any preceding claim wherein the trigger arm is generally arcuate along its length from the first to the second end.

21. The trap according to any preceding claim wherein the spring employed to spring load the strike arm comprises one or more coiled torsional springs wrapped around a spindle of the hinge.

22. The trap according to any preceding claim wherein the strike arm is provided with a plurality of ribs having long edges directed towards the treadle plate.

23. The trap according to any preceding claim, further comprising an enclosure.

24. The trap according to any preceding claim comprising at least two baffles, offset to direct an animal to deviate from a straight line passage.

25. A trap for small animals, the trap comprising a chassis mounting:

26. The trap according to claim 25 wherein the internal baffle is mounted part way along the treadle plate in the direction parallel to the hinge.

27. The trap according to claim 26 wherein the internal baffle is half way along the treadle plate in the direction parallel to the hinge.

28. The trap according to any one of claims 25 to 27 wherein the internal baffle extends across the treadle plate from the hinge edge towards the second edge.

29. The trap according to claim 28 wherein the internal baffle is an upstanding plate, extending across the treadle plate from the hinge edge towards the second edge.

30. The trap according to claim 29 wherein the internal baffle blocks passage for an animal moving across the treadle plate except through an aperture located towards the second edge of the treadle plate.

31. The trap according to any one of claims 25 to 30 wherein the strike arm is provided with a passage through which the internal baffle passes, in use.