Mouse and rat trap

Abstract: A mouse or rat trap (2) comprises a base (20), a striker (4) and an actuator (40), which are releasably connected, in combination with a spring (14) for biasing the striker (4) to a closed position. The components cooperate to provide a trap (2) which is easier to operate. An extension spring (14) is used to bias the trap to a closed position and in the set position, the spring force is primarily carried by the striker (4) and base (20) in a manner to increase the sensitivity of the actuator (40), as only a small load is carried by the surfaces of the actuator (40) and striker (4), maintaining the striker (4) in set position. Preferably, all components other than the spring (14) are of a molded plastic and snap fit together.

Description: The invention relates to a mouse or rat trap as defined in the preamble of claim 1. Mouse traps of this kind are known from US-A 2 174 929 (1937) and DE-A 2 623 394 (1977). The invention provides an improved mouse trap of the kind specified above as defined in the characterising portion of claim 1. In particular the large opening angle allows the striker to be accelerated over a relatively long angular path, so that the spring can be made weaker accordingly, which facilitates the opening of the trap. CA-A-1 139 929 shows a mouse trap made of card-board, and the spring is formed by a rubber band as generally used for closing parcels and the like. The closing force exerted by such a band depends on the manner in which it is applied, and, moreover, the elastic force of rubber bands will depend on the length and age thereof, so that, in practice, the forces obtained with such bands will widely vary. Furthermore the striker is provided with a latching tongue engaging a hole in the bait holder, which mechanism is liable to malfunctioning. Furthermore it is not kept in an over-centre position in respect of the band, which will make it more difficult to keep the trap open when applying the bait. The invention is shown in the drawings wherein: Figure 1 is a perspective view of the trap; Figure 2 is a perspective view of a vertical section of the trap; Figure 3 is a side elevation of Figure 5; Figure 4 shows the trap of figure 1 where the striker moves past the center position Figures 5 and 6 are side elevations showing the relationship between the striker and the base and the various hinge points to accomplish the modified structure of Figure 4. The trap generally shown as 2 in the drawings, is suitable for catching a mouse or rat or other small type animal and is designed to kill the same. The trap shown is for mice and a larger, stronger version is required for rats. For example, the rat version would be larger and the spring stronger. For simplicity the invention will be described with respect to the mouse trap version, however, the overall structure and cooperation of components work satisfactorily for larger traps. The striker 4, has a downwardly extending striking edge 6 adjacent the forward portion of the striker and is biased by extension spring 14. Journals 8 of the striker are pivotally received in bearing portions of the base 20. The base 20 has a forward edge 22 for cooperating the striking edge 6 of the striker, and act as the active surfaces which will result in the animal being killed. The base 20 of the trap has a full floor portion 26 and at the rear thereof bearing-type blocks 32 are provided for receiving the stub shafts 34 of the actuator 40. At the forward end of the base, stop posts 24 are provided which limit the downward movement of the striker 4. The upper surface of these posts 24 engage the striking edge 6 to thereby determine and end position of the striker. The actuator 40 has a front portion 42 which includes the bait recess area 44 having a raised lip region 45 thereabout. A permanent bait may be placed in the recess 44 or a small portion of cheese or other bait can be added. As the mouse enters the mouth of the trap adjacent the forward portion of the base 4, the actuator is upwardly angled and the mouse or rat, attracted by the bait, depresses the actuator 40 causing the same to release the striker to rapidly move towards the forward portion of the base 20 killing the mouse or rat. The striker, the actuator and base are all separately molded plastic pieces and basically snap-fit together. The trap is inexpensive to produce, easily set and not unduly complicated. The helical extension spring 14, preferably of metal, is disposed between the base 20 and the striker 4 for urging the striker towards a closed position, with edge 6 of the striker in engagement with or in close proximity to edge 22 of the base 20. As shown in Figure 1, the actuator 40 includes a ported area 54 through which the extension spring 14 extends to engage the base 20 at position 15. This ported area allows the actuator to freely move and also allows the spring to move as required to effect the desired movement of striker 14. The trap as shown in Figure 2 where the actuator includes a downwardly extending flange 60 rearward of the stub shafts 34, and this downwardly extending flange 60 acts both as a stop for the striker 4 and as a lever when the actuator is depressed for urging the striker through the center position such that the spring will cause the striker to move to the closed position. In the structure of Figure 2, the striker 4 is moved past the over center position, such that extension spring 14 serves to cause the striker to rotate about journals 8 and cause engagement of the rear portion of the striker with downwardly extending flange 60. Thus, the spring 14 causes the striker to be maintained in the set position. In the set position, the front portion of actuator 40 is raised and when a mouse enters the trap and attempts to take the bait from the bait holder, the weight of the mouse will cause rotation of the actuator about stub shafts 34, causing flange 60 to act as a lever and rotate the striker through the center position (very little additional force is required to effect the extension of the spring) whereupon the spring 14 now biases and accelerates the striker to the closed position. The details of the movement of the striker from the set position of Figure 2 and 3 to the closed position can be appreciated from a review of Figure 4, where flange 60 has caused the striker to move through the center position whereupon the spring urges the striker to the closed position. Figure 5 schematically shows the relationship between the striker 4, the journals 8, the base 20 and the extension spring 14 secured to the base at 15 and to the striker at 16. As can be seen, the striker 4 has been rotated such that a line drawn through point 15 and the center of journals 8 do not align with securement point 16. In fact, point 16 has rotated through the center position or point of maximum spring extension such that spring 14 is now urging the striker in the direction of arrow 75. This relationship ensures that the striker is maintained in the set position and will be in engagement with the downwardly extending flange 60 which acts as stop for the striker and causes a raising of the forward portion of the striker. It can be appreciated that other surfaces could provide the stop face, such as an extension of the base, while still causing the actuator to appropriately move to automatically set and when depressed move the striker through the over center position. In Figure 6, the actuator (not shown) has caused the striker to move through the center position (point 16 is now forward of the point where the spring force is aligned with a line through 15 and journals 8) and extension spring 14 now will rapidly move the striker to the non-operative position as indicated by arrow 77. The trap of Figures 1 through 6 operates on the principle that the cooperation between the actuator and striker, which maintains the striker in the set position, results in a relatively low load placed on the lock mechanism to render the tripping mechanism sensitive. This is accomplished as the extension spring goes through a position where substantially the major component of spring force is along a line defined by the journals of the striker and the point of securement of the spring to the base. Any components of the spring force in other directions, which are carried by the lock mechanism, are low.

Claims: A mouse or a rat trap, comprising: A base (26) and a striker (4), each having a first and a second extremity, said striker (4) being connected between its first and second extremities (16,) with the base (26) by means of a first hinge axis (8), allowing the striker (4) to be moved between a closed and an open position in respect of the base (26); a tension spring (14) attached to the striker (4) near its first end (16) and to a point (15) of the base (26) below said first hinge axis (8), so that, when moving the striker (4) towards the open position, this spring (14) is tensioned and finally passes said first hinge axis (8) towards an over-centre condition; stop means defining the open position with the spring (14) tensioned in its over-centre condition; an actuator (40) having a first and a second extremity connected to the base by means of a second hinge axis (34), a bait holder (44) being provided thereon between the first extremity and the second hinge axis (34), the second extremity of said actuator being situated near said second hinge axis (34); and the second extremities of said striker (4) and said actuator (40) contacting each other in the open position of the striker, and, when moving the actuator (40) downwards, the second extremity thereof forcing the second extremity of the striker (4) so far that the spring (14) will pass the first hinge axis (8) and will force the striker (4) towards the closed position, wherein in the open position, the actuator (40) defines with the striker (4) an angle of less than 90°, and the second extremity of the actuator (40) acts, in the open position, as the stop means; and the short arm of the actuator between the second extremity and the second hinge axis (34) is so that, when moving the actuator (40) downwards, this second extremity forces the second extremity of the striker (4) sufficiently for initiating the closing movement thereof until the spring (14) passes the first hinge axis (8), and, when moving the striker (4) towards the open position and tensioning the spring (14), the second extremity of the actuator (40) is in the path of the second extremity of the striker (4), so as to push the second extremity of the actuator (40) towards the position in which this extremity acts as said stop means, characterized in that: in the open position, the back of the striker (4) and the bottom of the base (26) define an angle in the vicinity of a right angle. The trap according to claim 1, characterized in that the second extremity of the actuator (40) comprises a downwardly extending flange (60) contacting the second extremity of the striker (4) in its open position.

Inventors: VAJS HELENA, VAJS LUBOMIR, VAJS, HELENA, VAJS, LUBOMIR
Applicants: VAJS HELENA, VAJS LUBOMIR, VAJS, HELENA, VAJS, LUBOMIR
Application year: 1988
Main classification: A01M23
IPC codes: A01M23