WO2021125978A1

WO2021125978A1 - A device for puncturing a container

Info

Publication number: WO2021125978A1
Application number: PCT/NZ2020/050153
Authority: WO
Inventors: Daniel Paris; John Wilks
Original assignee: Zero Invasive Predators Limited
Priority date: 2019-12-18
Filing date: 2020-11-18
Publication date: 2021-06-24

Abstract

The invention comprises device for puncturing a container, for example a canister (24), so that a fluid (eg a gas) is released from the canister at a controlled rate. The device comprises a spike, for example item (25), which has a peripheral arc portion and a peripheral chord portion. The device also has driving means adapted to force the spike (25) against the container to create a puncture that has a peripheral arc portion, and so that the spike's chord portion extends across the arc portion of the puncture to provide a gap of predetermined size. As a result the fluid is able to leave the container at the controlled rate.

Description

TITLE

A Device for Puncturing a Container

FIELD OF THE INVENTION

This invention relates to a device for puncturing a container, optionally but not necessarily for releasing a euthanising gas to eradicate a rodent or other animal, eg a rat or stoat.

BACKGROUND

Rats and stoats have significant adverse impacts on some natural ecosystems, for example in New Zealand. Rats eat seeds, flowers and fruits, birds and their chicks and eggs, as well as lizards, snails, invertebrates and larvae. Stoats are voracious predators of birds. There are various traps for rats and stoats, but they can be ineffective in that they are not necessarily effective in efficiently euthanizing a trapped animal.

OBJECT OF THE INVENTION

It is an object of a preferred form of the invention to go at least some way towards addressing the above problem. That said, the object of the invention per se is not so limited and is, rather, simply to provide the public with a useful choice. Therefore any objects of preferred embodiments should not be read into claims expressed more broadly.

DEFINITIONS

The term “comprising” if and when used in relation to a combination of features indicates minimum features present, but does not rule out the option of there being extra features that are not mentioned. The same applies to derivatives of the word, for example “comprises”, etc.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided a device for puncturing a container so that a fluid (eg a gas) is released from the container at a controlled rate, comprising: a) a spike that has a peripheral arc (eg rounded) portion and a peripheral chord (eg flattened) portion; and b) driving means (eg a spring/gear mechanism) adapted to force (eg rotate) the spike against the container to create a puncture that has a peripheral arc portion, and so that the spike’s chord portion extends across the arc portion of the puncture to provide a gap of predetermined size such that the fluid leaves the container at the controlled rate.

Preferably the spike is generally conical.

Optionally the device is such that the puncture is created by rotational forward movement of the spike against the container.

Optionally the driving means comprises a spring loaded gear and pinion adapted to rotate the spike a predetermined amount towards and into the container.

Optionally a tail of the spike fits into a complimentary slot of the pinion so that rotation of the pinion causes rotation of the spike.

Optionally a lug of the gear rotates in a track above the gear to limit rotation of the gear and as a consequence of the pinion and spike.

Optionally the driving means comprises a support cylinder with an internal thread that compliments an external thread of the spike, and the driving means is adapted to cause the spike to advance by screw turning the spike in the cylinder thread.

Optionally the device is part of a trap and is arranged to release the fluid into the trap to euthanise an animal when the trap has been set off by the animal.

Optionally the container holds substantially liquid CO₂ and the device is arranged so that the CO₂ becomes a gas at or about the gap.

Optionally the container is pressurised.

According to a further aspect of the invention there is provided a method of puncturing a container, comprising causing the spike of a device as set out above to rotate to puncture the container so that the puncture has a peripheral arc portion, and so that the spike’s chord portion extends across the arc portion of the puncture to provide a gap of predetermined size such that fluid leaves the container at the controlled rate.

Optionally the arc of the puncture is substantially in a circular path.

Optionally the chord portion of the spike is substantially linear (eg straight line).

According to a further aspect of the invention there is provided a trap comprising:

• an enclosure having at least one door;

• at least one treadle;

• an actuator having or associated with: o at least one magnet; and o at least one tensioned driver; and

• a connector mechanism between the actuator and the door; arranged so that the trap can be set to capture a target animal wherein: o the treadle is in or adjacent to a walk way of the enclosure and is held in a non-triggered position by the magnet; o at least some body weight of the animal, if on the treadle, will move the treadle to break the magnet’s hold; and o on breaking of the hold the driver urges the actuator towards a triggered position to cause the connector mechanism to close the door.

Optionally- a) there are at least two of the drivers and two of the magnets, each arranged in substantially the same way; b) each driver comprises a spring tensioned rod adapted to move in opposition to the hold of the magnets, but has insufficient force to move in that way until the hold is broken; c) there are two of the treadles arranged in substantially the same way so that either treadle can be triggered to move the actuator in a rotary manner with respect to a mount; d) there is a second door and the rotary movement of the actuator causes both doors to swing shut simultaneously; and e) the rotary movement of the actuator causes release of a euthanising gas into the enclosure. DRAWINGS

Some preferred embodiments of the invention will now be described by way of example and with reference to the accompanying drawings, of which:

Figure 1 is an isometric view of a trap when set for catching a rat; Figure 2 is an alternative isometric view of the trap when set;

Figures 3a-c provide detail of features of the trap; Figure 4 is an isometric view of the trap after it has been set off; Figure 5 is an isometric view of the trap with its lid closed;

Figures 6a-b are isometric views illustrating canister puncturing features of the trap;

Figures 7a-d illustrate the manner in which a canister forming part of the trap is punctured by a spike, to release a euthanising gas;

Figure 8 is an isometric view of a drive mechanism for the spike; Figure 9 illustrates the drive mechanism when disassembled; and Figures 10a-b are isometric views showing detail of the drive mechanism when partially assembled

DETAILED DESCRIPTION

Referring to Figures 1 and 2, the trap comprises an elongate box 1 having a hinged lid 2 and a door 3, 4 at each end. The trap has two treadles 5, 6 at the middle portion of the box’s floor 7. The treadles 5, 6 are either side of a tray 8 that holds a rat attracting substance, for example a sweet syrupy foodstuff 9. The foodstuff drops to the tray from a timed-release dispenser overhead (not shown) so that there is a constant supply in the tray. Each treadle 5, 6 is arranged so that if a rat stands on it, it will pivot in response to the rat’s bodyweight. This reference to bodyweight means a sufficient amount of weight, but preferably significantly less than the full weight of the rat. When the trap is ‘set’, each treadle 5, 6 is held more or less flush with the floor 7 (see Figure 2). This way the rat is less likely to detect and be spooked by a discontinuity in ‘feel’ as it moves through the trap onto one of the treadles 5, 6.

Each treadle has an arm 10 that extends to an overhead actuator 11. When the treadle pivots under the weight of a rat, the arm 10 pushes against and causes the actuator 11 to move in a rotary manner (eg a partial rotation). In this regard the actuator rotates from a central support 12. In the embodiment illustrated the support 12 comprises metallic cross beams 13, 14. The rotary movement of the actuator 11 causes the doors 3, 4 to swing down to shut. This is because the doors are mechanically linked to the actuator 11 by a series of rods 15, rod pivots 16a and door pivots 16b.

Rats tend to be very sensitive to ground movement beneath them. They are also typically agile and able to move quickly to retreat if spooked. For this reason the trap is formed so that when either treadle triggers the actuator 11 , the doors slam shut, rapidly, to prevent escape. If for example too much treadle movement or time is needed to close a trap, then a rat is given more warning before the doors lock it in.

Referring to Figures 3a and 3b, to facilitate rapid closing, the actuator 11 holds each treadle flush with the floor by way of magnets 17 that are attracted and magnetically connected to one of the cross beams 14. The balance is such that the magnets only need to move away from the cross beam 14 a slight amount before the actuator 11 rotates to bring the doors down.

Figure 3c illustrates further detail of the actuator mechanism and the way it relates to the cross beams 13, 14. The parts are shown disassembled, for ease of understanding. The rotational movement of the actuator 11 is accelerated by drivers.

In this embodiment each driver is in the form of a spring-tensioned push rod 19 housed within a sleeve 19a, and positioned next to a respective one of the magnets 17. When the trap is set with the magnets holding the treadles flush, springs 19b associated with the rods 19 bias them to push against the cross beam 14. In that situation the force from the springs is insufficient to break the attraction between the magnets 17 and the cross beam 14. As treadle movement causes the magnets to separate from the beams, the spacing weakens the magnetic attraction and, as a result, the springs are able to drive the push rods 19 outward against the cross beam 14. This causes rapid rotary acceleration of the actuator 11 , to close the doors fast.

Preferably the magnets 17 touch the cross beam 14 when the trap is set. The amount of body weight needed on each treadle to trigger the actuator can be changed by screw adjusting the amount of tension on the springs 19b when the actuator is in its ‘trap set’ position. The adjustment screws are shown at 19c.

Figures 3a and 3b also illustrate detail of the way the actuator 11 interacts with the rods 15, the rod pivots 16a and the door pivots 16b that mechanically link the actuator 11 to the doors. In Figure 3b the parts are in a ‘trap-set’ disposition where one end of the rod 15 is permanently fixed to the rod pivot 16a, and the other end sits freely in a seat 20 of the actuator 11. The door pivot 16b has a shoulder 21 that sits under the rod pivot 16a. And, as shown, the door 2 sits on top of an opposite shoulder of the door pivot 16b to hold it open against the closing ‘bias’ of a door spring 22. As will be appreciated, spring loaded downward force by the door 3 at one end of the door pivot 16b produces an upward force on the far shoulder 21 . That in turn produces a pivot force at the rod 15 to press its distal end down into the actuator’s seat 20. As long as the rod 15 is sitting in the actuator seat 20 the door cannot drop to close. Put another way, the force of the door down onto the door pivot 16b, coupled with the inability of the door pivot’s far shoulder 21 to push upwards past the rod pivot 16a, means that the door pivot is unable to turn. As a consequence the door is unable to swing down and close.

When the trap is triggered at one of the treadles, the actuator 11 rotates away from the free end of the rod 15. This causes the distil end of the rod 15 to drop out of the actuator’s seat 20 and the rod pivot 16a to rotate clockwise. This frees the shoulder 21 so that the door pivot 16b rotates counter-clockwise. The result is that the door drops to a closed position, rapidly, under pressure from the door spring 22. The arrangement of parts when the trap has been triggered is shown in Figure 3a and Figure 4.

As indicated, both ends of the trap are arranged the same way so that both doors close simultaneously in the same manner, regardless of which treadle is sprung. When the trap is set for action the lid is closed so that the rat is unable to escape out the top. The trap when closed is shown in Figure 5. In that disposition its communications antenna 18 is visible. The antenna is arranged to send a wireless signal to a base station when the trap has been set off, so that a human worker knows to go to the trap to clear and reset it.

The box is formed long enough so that when the trap is triggered, the distance to the doors is too great for the rat to escape.

The rotational movement of the actuator 11 also triggers release of a fatal volume of gas, for example CO2, into the box. This provides for relatively quick and pain free euthanasia of the rat. The canister 24 is visible in figures 1 , 2 and 4. The arrangement is such that the canister 24 releases gas when the actuator 11 is triggered.

Referring to Figures 6a and 6b, it is desirable that the gas be released from the canister 24 at a controlled rate, to flood the box with a sufficient amount in a sufficient time. For example at a rate where the animal is not panicked by a surge of gas, but rather succumbs to the gas slowly, over the space of a few minutes. To facilitate this the trap incorporates a spike 25. Figure 6a shows the spike 25 just before it is moved upwards to puncture the canister 24. Figure 6b on the other hand shows the arrangement when the spike has been screw rotated up into the throat of the canister to create a gas releasing puncture.

Figures 7a-c show three positions of the spike 25 as it moves towards and into the canister 24. Each drawing provides a transverse and lateral cross section for the canister and the spike. In Figure 7a the spike 25 is almost in contact with the canister 24, in Figure 7b the spike has been screw rotated into the canister to create a puncture, and in Figure 7c the spike has been screw rotated further into the canister to expand the puncture. The spike 25 is generally cone shaped, but has a flat discontinuity. The cone’s curved portion is indicated at 26, and the discontinuity is indicated at 27. The curved portion 26 is arc-like and the discontinuity 27 is chord-like. In preferred embodiments, when viewed in plan, the arc is regular circular, and the discontinuity is straight. Flowever in some embodiments the arc may be other than straight, for example a region of much less curvature, or zig-zagged, etc, and yet still function adequately in the manner described below. When the spike 25 rotates into the canister it creates a generally circular aperture. As the spike rotates further in, the discontinuity, instead of following the curvature of the aperture’s periphery, extends across it like a chord, so that there is a gap 29 of predetermined size. This gap provides an exit for the gas under pressure, at the desired rate. Figure 7d provides a close-up view of the gap 29.

Referring to Figure 8, the trap has a drive mechanism 30 inside the box and this houses the canister 24 and the spike 25 (not visible). The mechanism 30 has a trigger 31 that is engaged with and can be tripped by the same movement of the actuator 11 that brings the doors down.

Figure 9 shows the drive mechanism 30 when disassembled. It has a gear 32 that meshes with a pinion 33. The gear 32 is tensioned by two springs 34 so that when the mechanism 30 is triggered, the spring causes the gear 32 to rotate. This in turn causes rotation of the pinion 33. Because a tail 25a of the spike sits snugly in a slot of the pinion 33, when the pinion rotates so does the spike. The spike 25 is screw-fitted in a support cylinder 35, so that when the spike rotates it moves upwards to puncture the canister 24 (not shown).

Referring to Figures 10a and 10b, the gear 32 has a lug 36 on its upper face that runs in an arc shaped track 37 in a housing-cover 38 (see Figure 9). Because the lug 36 is restricted by the track 37, it only allows the gear 32 to turn a limited amount, being less than one revolution. In Figure 10b the lug 36, and therefore the spike 25, have rotated further than in Figure 10a. The limited rotation of the gear 32 means limited rotation of both the pinion 33 and the spike 25, so that the depth to which the spike enters the canister, and therefore the size and other characteristics of the puncturing aperture, are controlled.

Referring further to Figures 10a and 10b, the trigger 31 has a slot 39 for engaging with the actuator 11 (not shown). When the trap has yet to be set off, a lower blade 40 of the trigger engages the gear 32 to prevent it rotating. When the actuator 11 rotates as above, it pushes on the trigger 31 so that that trigger pivots to move the blade 40 clear of the gear 32, so that the gear can rotate as above. The location of the drive mechanism 30 is generally indicated by the position of the canister 24 in Figure 2. As shown, it sits to the side of the actuator 11 and the treadles 5, 6 in a wider portion 41 of the box. Although the trap has been described in relation to rats, it can also be used with stoats and various other animals. It can be formed in different sizes and with different spring tensions if need be, to accommodate smaller or larger animals.

While preferred embodiments of the invention have been described by way of example, it should be appreciated that modifications and improvements can occur without departing from the scope of the accompanying claims.

In terms of disclosure, this document contemplates and hereby discloses any one or more features described above in combination with any one or more other features described above, even if not claimed. Such combinations may or may not have repeating features, e.g. two or more of the same feature in the combination.

Claims

1. A device for puncturing a container so that a fluid is released from the container at a controlled rate, comprising: a) a spike that has a peripheral arc portion and a peripheral chord portion; and b) driving means adapted to force the spike against the container to create a puncture that has a peripheral arc portion, and so that the spike’s chord portion extends across the arc portion of the puncture to provide a gap of predetermined size such that the fluid leaves the container at the controlled rate.

2. A device according to claim 1 , wherein the peripheral arc portion is a substantially circular portion.

3. A device according to claim 1 or 2, wherein the chord portion is a substantially flattened portion.

4. A device according to claim 1 , 2 or 3, wherein the spike is generally conical.

5. A device according to any one of the preceding claims, adapted to create the puncture by rotational forward movement of the spike against the container.

6. A device according to any one of the preceding claims, wherein the driving means comprises a spring loaded gear and pinion adapted to rotate the spike a predetermined amount towards and into the container.

7. A device according to claim 6, wherein a tail of the spike fits into a complimentary slot of the pinion so that rotation of the pinion causes rotation of the spike.

8. A device according to claim 6 or 7, wherein a lug of the gear rotates in a track above the gear to limit rotation of the gear and as a consequence of the pinion and spike.

9. A device according to any one of the preceding claims, wherein the driving means comprises a support cylinder with an internal thread that compliments an external thread of the spike, and the driving means is adapted to cause the spike to advance by screw turning the spike in the cylinder thread.

10. A device according to any one of the preceding claims, incorporating the container.

11. A device according to any one of the preceding claims, which is part of a trap and is arranged to release the fluid into the trap to euthanise an animal when the trap has been set off by the animal.

12. A device according to claims 11 , wherein the container holds substantially liquid

CO2 and the device is arranged so that the CO2 becomes a gas at or about the gap.

13. A device according to any one of the preceding claims, wherein the container is pressurised.

14. A device according to claim 1 , wherein - a) the container is fitted to the device; b) the puncture has been created by rotational movement of the spike against the container; c) the peripheral arc portion is substantially circular; d) the chord portion is a substantially flattened; e) the driving means comprises a spring loaded gear and pinion adapted to rotate the spike a predetermined amount towards and into the container; f) a tail of the spike is fitted into a complimentary slot of the pinion so that rotation of the pinion causes rotation of the spike; g) a lug of the gear rotates in a track above the gear to limit rotation of the gear and as a consequence of the pinion and spike; and h) the driving means comprises a support cylinder with an internal thread that compliments an external thread of the spike, and is adapted to cause the spike to advance by screw turning the spike in the cylinder thread.

15. A method of puncturing a container, comprising causing the spike of a device according to anyone of the preceding claims to rotate to puncture the container so that the puncture has a peripheral arc portion, and so that the spike’s chord portion extends across the arc portion of the puncture to provide a gap of predetermined size such that fluid leaves the container at the controlled rate.

16. A method according to claim 15, wherein the arc of the puncture is substantially of a circular path.

17. A method according to claim 15 or 16, wherein the chord portion of the spike is substantially linear.

18. A trap comprising:

• an enclosure having at least one door;

• at least one treadle;

19. A trap according to claim 18, wherein - a) there are at least two of the drivers and two of the magnets, each arranged in substantially the same way; b) each driver comprises a spring tensioned rod adapted to move in opposition to the hold of the magnets, but has insufficient force to move in that way until the hold is broken; c) there are two of the treadles arranged in substantially the same way so that either treadle can be triggered to move the actuator in a rotary manner with respect to a mount; d) there is a second door and the rotary movement of the actuator causes both doors to swing shut simultaneously; and e) the rotary movement of the actuator causes release of a euthanising gas into the enclosure.