AU603110B2 - Trap - Google Patents

Description

603110 FEE STAMP~ To VALUE OF AaTACtIED LODGED AT SUB..FiCE 2 JUN 1W~ Melbourne 'a

S

S

0

S.

S

S

APPLICANT:

NUMBER:

FILING DATE: CARL PETER DALTON PH 6532/86 This document contains the amendments made under Section 49 and is correct for printing 23 Jun 86 4'.S a S

S

S

04

S.

FORM COMMONWFALTH OF AUSTRALIA The Patents Act 1J052 COMPLETE SPECIFICATION FOR AN INVENTION

ENTITLED:

TRAP

The following statement is a full description of this invention, including the best method of performing it known to me: -1- This invention relates to traps and, in particular, to traps which are specifically useful for trapping a number of rodents although, as the trap can be used either to kill or not kill the inhabitents, they would equally well be useable for trapping, for example, animals which are to be captured alive.

In areas where there can be large congregations of rodents, and for simplicity throughout this specification I shall refer to the trap of the invention being used for rodents without limiting the generality of the I invention in any way, conventional traps are of little value.

S Any trap to be used in these conditions must be able to reset and must be o• •capable of containing a large number of the rodents to be trapped.

It is the object of the present invention to provide a trap of such a type that it meets the desiderata, that is, that it can be used to capture more .os than a single rodent and is automatically self-setting.

0* The trap, in its broadest form, a trap comprising a swinging plate in a cover .o over an enclosed space, the plate being hinged along one side, retaining means adjacent the opposite side to normally hold the plate in a closed position, but which can be released by a rodent on the plate, and restoring ,means associated with the hinge whereby, when the plate has been opened, it automatically returns to its closed condition in which it is held by the fiJ retaining means opposite the hinge thereby resetting the trap, bait Ireceiving means adjacent the end of the plate at which the retaining means Sis located and a restriction between the plate and bait receiving means through which the rodent must pass its head to reach the bait.

SIn a first embodiment of the invention, the plate may be held in its required ;L S DlrN -2- Da I ton/63/May87 closed position by a magnet and the restoring means to return the plate to its closed position may be counterweight means associated with the plate on the side of the hinge away from the plate, or may be bias means 0 se 00 0005

S

SOS.

S.

55 0 @0 0 0 005 5* @0 0 .0

S

SSqS@0 0 0 -12a. Dal tonf63/May87 i

S

SS

S S

S.

.i eses

S..

S

whereby the plate is moved towards the magnet. In either situation, the movement is such that the free end of the plate becomes sufficiently close to the magnet for the magnetic attraction to permit the plate to close.

Rather than using some fixed method of closure of the plate, such as a permanent magnet, it is possible to provide an active means of retaining the plate closed, such as an electromagnet, which is triggered by the rodent passing through, for example, an infrared beam.

The arrangement, otherwise, is similar to that described.

Practical arrangements of traps according to the present invention will now be described with reference to the accompanying drawings. In these drawings:- Fig. I is a perspective view of one form of the trap; Fig. 2 is a cross section on the line 2-2 of Fig. 1; Fig. 3 is a cross section of a second form of trap; Fig. 4 is a view on a larger scale of a detail shown in Fig. 3; Fig. 5 is a plan of a third form of trap; Fig. 6 is a cros section on the line 6-6 of Fig. Fig. 7 is a plan of a fourth form of trap; Fig. 8 is a cross section of portion of a fifth form of trap; Fig. 9 is a cross section of portion of a sixth form of trap; and Fig. 10 is a plan of one component of "the trap shown in Fig. 9.

In the first form, shown in FPigs. I and 2, the trap may comprise a steel box 11, the size of which would depend upon the size of rodent to be caught, and, to a degree, the number of rodents to be caught.

-3- Dalton/63/May87

I,

@0Sg 10 S S

*SS@

5555

S

0550

S.

0 0 00

S

S. S

S

S.

Preferably, the top of the box, which incorporates the trap mechanism, may be removeable therefrom to enable access to the interior thereof.

As well, the box is provided with a hinged door 12, the location of which may vary depending upon the way in which the trap is to be used.

The trap itself comprises an aperture in the upper surface through which the rodent is to pass when the trap is sprung and, in a particular form, this aperture is of a wedge shape and it is provided with side walls 13 and 14 which are tapered inwardly to a closed end 15 and which provide a means to direct the rodents towards the closed end.

At the end of these walls, there is a bait receiving tray 16, which is supported by portion 17 of the top forwardly of the aperture. It could alternatively be connected between the walls above portion of the aperture.

The trap plate 18 itself is hingedly located within the aperture with the hinge 19 along the wider edge of the aperture.

The plate is tapered to generally conform with the shape of the aperture.

Alternatively, it could simply be rectangular or any other shape of a size sufficient to extend beyond the edges of the aperture thus occluding the aperture.

A permanent magnet 20, supported by the top 17 is located above the free end of the plate to maintain it normally against the underside of the top.

The trap plate 18 is provided with a counterweight 21 located on a cut out portion 22 of the base, which is a continuation of the plate and is on the side of the hinge away from the trap plate, which counterweight acts to -4- Dalton/63/May87 if j i 1 tend to cause the trap plate to move upwardly so that it comes within the range of the magnet attraction of the magnet 20 and thus will tend to operate, together with the magnet, to maintain the trap in a closed condition.

A top 24 extends between the walls 13 and 14 to completely enclose the region above the plate 18 except at the entry 25. A short wall 26 extends down from the top 24 at a position opposite to an upward ramp 27 attached to the top of the plate 18 near its free end, to leave a narrow gap through .which bait on the tray 16 is visible.

10 In operation, the trap can either be sunk into the ground or it can be provided with a ramp to enable ready access to its upper surface or it can be stacked with boxes which, again, enable ready access to the upper surface.

The particular arrangement will depend upon where the trap is to be used.

A bait, which may be any food attractive to the rodent to be trapped, is located on the tray 16 adjacent the closed ends of the walls on the top of the trap and the trap itself is shut.

It will be seen that, when a rodent passes onto the upper surface of the plate 18 between the walls and reaches a position towards the closed end of the walls, there/wii come a situation where the turning moment about the Shinge 19 provided by the weight of the rodent exceeds the holding force of the magnet 20 and the counterweight 21 and, at this stage, the magnet will release and the weight of the rodent will cause the plate to drop o Re downwardly, the rodent will fall from the plate and, on release of this L S L' weight, the counterweight 21 will cause the trap plate to move upwardly Da I Dalton/63/May87 r~pq- 0Seug Ss 0g.

*0 0 6S 00 0 0 0 0000 00*6

S

0 0 until it comes into a position where the magnetic attraction occurs and the trap closes. If the weight of the rodent is not sufficient to cause the plate to drop, when the rodent pushes its head through the space between the wall 26 and the ramp 27 an additional force will be applied to the ramp and it will release.

It will, of course, be appreciated that the depth of the trap, if it is simply to receive rodents, must be such that no rodent already in the trap could jump onto the plate 18 when it is in its downward position.

It will be seen that the operation of the trap can readily be varied for different sized rodents simply by varying the strength of the magnet which causes the trap to close.

For example, if one wished to catch relatively heavy rodents, the strength of the magnet may be such that a lighter animal or something such as a bird or lizard would not be sufficient to cause the trap to operate, but an animal in the range of weight of the rodent to be trapped would be trapped.

1'- -ij If the trap is to be used to catch rodents alive, it will need to be simply as described, the door 12 enabling the ready removal of the rodents, and I may also prefer to provide drainage apertures adjacent the floor of the trap so that, should water or other liquid enter the body of the trap, this can drain therefrom.

If the trap is to kill rodents, I prefer to provide killing means in the trap and one such arrangement would be to provide the trap with a mixture of water and a chemical which will cause death and such chemicals could include such things as potassium chloride, atropine, digoxin or lignocaine.

n/6/May76- ,n/6_'./May87 ?-Vp

LS

(V C Da tt 3 1 These chemicals, if swallowed, and when the rodent falls into the trap it would normally tend to swallow, cause either tachycardia or bradycardia which, in turn lead to cardiac failure, and the rodent dies rapidly. Under e.g.

S0 C

SC

C.

S.

5 0 0 9**S 0*

C

S

500S S S C. S Sm

S

*0S

C*

C

CS

S

S OS S SO

C

6a Dal toh/6 3/May87 i i i i I such an arrangement I would normally provide drain holes slightly above the required level of chemical so that, should further liquid enter the trap, it is drained and, in these circumstances, the door 12 will of course, have to be located above the level of the chemical.

Whilst this simple form of trap could be quite suitable for many applications, there will be other applications where it is necessary to provide a large number of traps and, indeed, it may be desirable in some applications to provide a barrier which consists of a number of traps located side by side so that any attempt by a rodent to cross the barrier off@ 10 will cause the rodent to be trapped.

V o *In such arrangements, I can either make multiple traps or I can arrange to gog locate traps closely adjacent to each other and, preferably, provide a •go• means whereby the rodents are effectively restricted from passing across the barrier except by passing onto a trap plate.

oThis may be done by providing means which overlie portions of the walls which serve to provide an interconnection between the traps and which, at Sthe same time, can provide a barrier to the passage of the rodents.

For example, these could be oval shaped domes having a smooth or needle like surface over which the rodent cannot readily pass and, as such, the rodent is caused to be led between adjacent domes onto the trap plate to a position where it is trapped.

Whilst in the form of trap described I use a magnet as the engaging means, it is possible to provide several different methods of operation, each of which have the same effect, that is the trap will maintain weight until a certain situation occurs, after which time it will be released.

-7- Da Iton/63/May8 7 r::1 The first of these may be a mechanical arrangement as shown in Figs. 3 and 4.

In this case, the plate 18 itself has an upstanding portion 30 at its free end which portion has outwardly directed extensions 31 and 32 which are shaped to provide a rectangular space.

Located between these is preferably a steel plate which acts to provide a surface against which a magnet can act.

0"99 In this arrangement I provide a lever in the form of a bell crank pivotted at 33 above the plate, one arm 34 of the bell crank extending downwardly, and 10 the other arm 35 extending over the plate itself.

@6* At the lower end of the arm 34 there is both a counterweight 36, which tends to cause this arm of the bell crank to rotate towards the plate 18, but .which is insufficient to cause it to rotate so that it fouls the plate, and a magnet 37 which is directed towards the plate and which is of a shape to fit between the extensions 31 and 32.

The arm 35 is a trigger ramp which, when the trap is in its open position, is below the level of the plate 18.

I r The operation is that, when the trap is set, the bell crank is rotated about its pivot 33 so that the magnet 37 is received between the extensions 31 and 32 and is held in this position by its attraction to the steel plate.

The free end of the ramp 35 is higher than the trap itself.

When a rodent passes on the trap and onto the trigger ramp 35, which it is obliged to do if it is to get to the bait which is above the pivot 33, then the D o 3-8- Da l ton/63/May87 1 c I pn~, trigger ramp will mnove causing the bell crank to rotate, the magnet to be freed from the plate, thus releasing the mechanical stop, and the plate 18 wi,' drop.

After the rodent has left the trap, the plate 18 will move upwardly under a counterweight, as described in relation to the earlier embodiment.

As it approaches its final position, the trap plate comes into contact with the ramp 35 which causes rotation of the bell crank, the arrangement being such that, the magnet will pass between the extensions 31 and 32 and will s.e be drawn into its required position acting against the steel plate and the 10 initial condition will be established.

0:0 In a still further embodiment of the invention, I provide a positive and direct release means.

t In such an arrangement I provide means which are actuated by the I~ 0 movement of the rodent, such as either a passive IR detector, or an infrared beam being reflected from a surface or a light beam, each of which, when actuated, provides a positive release.

S In one particular form, shown in Figs. 5 and 6, the trap comprises a .I cylindrical steel drum 40 having its top open except for an annular ledge 41 -around the edge. An axial pillar 42 extends through the cylinder to project above the open top, and terminates in a conical cowl 43 of opaque material. A circular steel plate 44 coplanar with the ledge 41 is fixed at its centre to the pillar 42.

The opening at the top of the drum is covered by eight sector-shaped plates each hinged at 46 to the inner edge of the ledge 41, and each provided -9- Dal ton/63/May87 with an extension 47 to which a counterweight 48 is attached.

Electromagnets 49 are attached, one to the free end of each of the plates Each plate 45 carries on its upper surface near its free end an infra-red sensor 50 connected by wiring to a switch and a battery (not shown) located on the ledge 41. The battery is connected by wiring to the electromagnet 49.

A source of infra-red radiation 51 is located under the cowl 43 and is directed on to the sensor 50. The switch is so arranged that, when the *sensor is receiving radiation from the source 51, current flows to the 10 electromagnet 49, and, when the radiation is interrupted, the flow of I current to the electromagnet is also interrupted.

.0 0* In use, bait 52 is placed on the plate 44, and the rodent, in endeavouring to reach it, covers the sensor 50, with the result that the flow of current to .the electromagnet 49 ceases, and the plate 45 falls. After the rodent has .0 fallen from the plate 45, the counterweight 48 restores the plate to its normal position. As the sensor 50 is again exposed to the radiation from the source 51, current again flows to the electromagnet 49, so that the plate 45 is held in position awaiting the arrival of another rodent.

As an alternative to the electromagnet, I could use a mechanical latch +s i a 20 which is freed when an alarm device is triggered.

Fig. 7 shows a variation of the arrangement shown in Figs. 5 and 6, in which the drum 40 is substituted by a rectangular tank 60. Plates 61 are hinged at 62, and are retained in their normal position by means of the same kind as described with reference to Figs. 5 and 6.

An alternative to the arrangements of permanent magnets shown in Figs. I Dalton/63/May87 I'

I--

I 0000 1

S..

0 to 4, is shown in Fig. 8. A magnet 71 is carried by a plate 72 which is normally maintained in a horizontal position by a spring 73. As a rodent advances along the plate 18, the attraction of the magnet 71 is overcome and the plale falls. Due to the attraction of the magnet, the plate 72 will also fall slightly, as shown in dotted lines. The counterweight will return the plate 18 to the normal position when the rodent has fallen. The spring 73 will return the plate 72 to the normal position.

In the form of the invention shown in Figs. 9 and 10, the plate 18 is normally held against a fixed plate 80 by a permanent magnet 81. A lever 82 and a shorter lever 83 are fixed together in a V-shaped configuration, and are pivoted where they join at 84 above the plate 18. The longer lever 82 is so located that it will be reached by an approaching rodent before the lever 83 is reached. The lever 83 rests with its free end on the plate 18.

In operation, an approaching rodent climbing on to the lever 82 will cause the lever 83 to press the plate down, wi'h a mechanical advantage resulting from the difference in length of the levers.

In order to ensure that the rodent does not by-pass the levers, the plate 18 is shaped as shown in Fig. 10. The part 85 of the plate which is contacted by the lever 83 is narrowed to be no wider than the levers.

The basic concept of these versions of the trap is, of course, identical to the earlier version, although their particular form of operation does vary somewhat.

Also, in each of the embodiments, I have discussed the closure of the trap as being basically under the actuation of a counterweight.

0S 00 0S0

SS

S

0@ @0 00 S @0 OS 0 0 00* 0@* -lr e 1

A

.4 j

L

Dalton/63/May87

I--

r It would be perfectly feasible to replace this counterweight with a spring which could either be a spring wrapped around the axis of the hinge or a spring extending to some other part of the trap.

Such arrangement would effectively be identical in operation to the embodiments described.

It will be understood that whilst I have described several different embodiments of my trap, there can be numerous variations in these without departing from the spirit and scope of the invention.

0e@ *e0.

00 0 se e 0* *0 0 0

S

S

6SS

S

S*

S S

S

0 09

I

:I

f !12 -r ~ili IBer Dalton/63/May87 -12-

Claims (13)

1. A trap comprising a swinging plate in a cover over an enclosed space, the plate being hinged along one side, retaining means adjacent the opposite side to normally hold the plate in a closed position, but which can be released by a rodent on the plate, and restoring means associated with the hinge whereby, when the plate has been opened, it automatically returns to its closed condition in which it is held by the retaining means opposite the hinge thereby resetting the trap, bait receiving means adjacent the end of the plate at which the retaining means is located and a restriction I .between the plate and bait receiving means through which the rodent must pass its head to reach the bait.

2. A trap according to claim I, wherein the retaining means is a magnet.

3. A trap according to claim 1 or claim 2, wherein the restoring means is a counterweight associated with the plate on the side of the hinge away from the plate. S S

4. A trap according to claim 2 or claim 3, wherein the retaining means is an electromagnet activated by an electric current which is interrupted when a trigger is operated by an animal.

A trap according to claim I wherein the retaining means comprises a mechanical lock which is displaced by the weight of the rodent to V7 r U, -13- 1\ o< Dalton/63/May87 a -ru permit the plate to rotate about its hinged side.

6. A trap according to claim 5 wherein the lock includes a lever, part of which extends over the plate and which is adapted to be actuated by the rodent to permit the lock to be freed.

7. A trap according to claim 6 wherein the lever is in the form of a bell crank, one arm of which overlies the plate and the other arm has a *see male or female member extending towards the plate and adapted to engage with a female or male member on the plate whereby, on rotation of the bell crank under the weight of the rodent, the male •0o* 000I and female members separate to permit the plate to rotate about its 0• hinge.

8. A trap according to claim 7 wherein the bell crank is biassed so that, when the plate returns to its closed condition, there is again re- engagement of the male and female members.

9. A trap according to any one of claims 1 to 3 wherein there is a against the plate to release the retaining means.

A trap according to claim 9 wherein the lever is pivotted about a pivot parallel to and in the same plane as the plate and the retaining I means is a magnet in the lever or the plate where they overlap.

11. A trap according to claim 9 wherein the lever is a bell crank, one SDalto -14- U Dalton/63/May87 r* i s~--narr~ rra~~ i arm of which can contact the plate and the other is which is moved by the rodent, a mechanical advantage being achieved between the two arms to enable the plate to open.

12. A trap according to claim 4, wherein the trigger comprises a switch and an infra-red sensor.

13. A trap substantially as hereinbefore described with reference to Figs. I and 2 accompanying drawings. DATED this 17th day of July, 1990 S 0SO* 0S GS 0S 00 *000 B 006 e g. 0 0000 0000 0 0e 00 CARL PETER DALTON By his Patent Attorneys A. TATLOCK ASSOCIATES i ii I ,I I i :i iY U Dalton/63/May87 re -i 1