Backlash vibration structure for toy rifle

A backlash vibration structure for toy rifle (air soft rifle, BB-rifle) formed of a receiver extension, a weight, a reaction spring and a buttcap spacer is disclosed. The weight has a front extension inserted through the lower receiver of the toy riffle and connected to the rear end of the piston spring at the rear side of the piston so that the component parts of the backlash vibration structure doe not touch the piston during movement of the piston. An adjustment knob is provided at the buttcap spacer for adjustment of the reaction spring to adjust the level of the backlash vibration.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a toy rifle (air soft rifle/BB-rifle) and more particularly, to a backlash vibration structure for toy rifle that improves the connection relationship between the piston and the weight.

2. Description of the Related Art

To simulation of a real automatic rifle, a toy rifle (air soft rifle/BB-rifle) may be provided with a backlash vibration structure. Taiwan Patent Publication No. 200708712 discloses a similar design. However, this design is still not satisfactory in function.

FIG. 1illustrates a backlash vibration structure a′ installed in a toy riffle. As illustrated, the backlash vibration structure a′ is arranged at the rear side in axial alignment with the piston10in the piston-cylinder mechanism b′, comprising a receiver extension20, a weight30, a reaction spring40, and a buttcap spacer50. The receiver extension20is connected to the rear side of the lower receiver c′ that accommodates the piston-cylinder mechanism b′. The weight30and the reaction spring40are mounted inside the receiver extension20. The reaction spring40is connected between the weight30and the buttcap spacer50. The piston10has its rear side mounted with a piston spring101. The piston spring101has its one end received in the piston10, and its other end stopped against an inside wall of the lower receiver c′. Further, a connection rod60is movably inserted through the lower receiver c′ and connected between the piston spring101and the weight30. The toy riffle further comprises a transmission mechanism d′, a trigger e′ and a bullet pusher f′. When pressed the trigger e′, the transmission mechanism d′ is forced to move the piston-cylinder mechanism b′, causing the bullet pusher f′ to push the bullet into the firing position for striking by (the firing pin of) the piston10. During movement of the transmission mechanism d′, the piston10is moved backwards, and the connection rod60is moved with the piston10to force the weight30against the reaction spring40(seeFIG. 2). When over the compression limit of the reaction spring40, the reaction spring40forces the weight30forwards, and the piston10is moved forwards in a rush to shoot the bullet (see alsoFIG. 1). During forward movement of the weight30, a reactive force is produced, causing a backlash vibration.

According to the aforesaid design, the connection rod60is connected between the piston spring101and the weight30and has its front end suspending in the piston10, the inside wall of the piston10will strike the front end of the connection rod60during backward movement of the piston10, and the front end of the connection rod60will strike the inside wall of the piston10during forward movement of the weight30. Therefore, the piston10wears quickly with use. Further, the pressure of the backlash is determined subject to the weight of the weight30and the spring force of the reaction spring40and the piston spring101. However, because the weight of the weight30is fixed, and the spring force of the reaction spring40and the piston spring101will be gradually reducing after a long use. In consequence, the backlash vibration will become small and not adjustable after a long use of the toy riffle. Therefore, an improvement in this regard is necessary.

SUMMARY OF THE INVENTION

The present invention has been accomplished under the circumstances in view. It is the main object of the present invention to provide a toy rifle (air soft rifle/BB-rifle) backlash vibration structure that greatly prolongs the working life of the piston. It is another object of the present invention to provide a toy riffle backlash vibration structure that allows adjustment of the level of the backlash vibration.

To achieve these and other objects and according to one aspect of the present invention, the backlash vibration structure installed in a rear side of a lower receiver of a toy riffle in axial alignment with a piston in a piston-cylinder mechanism, comprising a receiver extension affixed to the rear side of the lower receiver, a weight mounted in and movable along the receiver extension relative to the lower receiver, a buttcap spacer detachably fastened to a rear side of the receiver extension, and a reaction spring connected between the weight and the buttcap spacer. The weight comprises a base mounted in and movable along the receiver extension and stopped against the front end of the reaction spring, a front tip suspending in the lower receiver and connected to the rear end of the piston spring, and a front extension inserted through the lower receiver and connected between the base and the front tip.

According to another aspect of the present invention, the buttcap spacer is detachably fastened to the rear side of the receiver extension for easy maintenance of the component parts of the backlash vibration structure.

According to still another aspect of the present invention, the backlash vibration structure further comprises an adjustment knob mounted in the buttcap spacer and stopped against a rear end of the reaction spring opposite to the weight and rotatable relative to the buttcap spacer to adjust the spring force of the reaction spring.

According to still another aspect of the present invention, the backlash vibration structure further comprises a stop plate fixedly fastened to the adjustment knob and stopped against the rear end of the reaction spring.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring toFIG. 3, a backlash vibration structure a is arranged at the rear side in axial alignment with a piston1in a piston-cylinder mechanism b of a toy riffle. The piston1has a piston spring11mounted in its rear side. The piston spring11has its one end received in the rear side of the piston1and connected thereto. The toy riffle further comprises a transmission mechanism d, a trigger e and a bullet pusher f arranged in a lower receiver c under the piston-cylinder mechanism b. When pressed the trigger e, the transmission mechanism d is forced to move the piston-cylinder mechanism b, causing the bullet pusher f to push the bullet into the firing position for striking by (the firing pin of) the piston1.

The backlash vibration structure a comprises a receiver extension2, a weight3, a reaction spring4, and a buttcap spacer5. The receiver extension2is connected to the rear side of the lower receiver c that accommodates the piston-cylinder mechanism b. The weight3and the reaction spring4are mounted inside the receiver extension2. The reaction spring4is connected between the weight3and the buttcap spacer5. The weight3comprises a cylindrical base31, a front tip33, and a front extension32axially connected between the cylindrical base31and the front tip33. The cylindrical base31is received in the receiver extension2. The front extension32is inserted through (a hole on) the lower receiver c. The front tip33is fastened to one end of the piston spring11opposite to the piston1. The buttcap spacer5is detachably fastened to the rear side of the receiver extension2(by, for example, a screw joint, as shown inFIGS. 6 and 7). An adjustment knob6is fastened to the buttcap spacer5and rotatable to adjust the spring force of the reaction spring4. The adjustment knob6has its front side fixedly mounted with a stop plate61that is stopped against the rear end of the reaction spring4. The reaction spring4has its front end fastened to the rear side of the cylindrical base31of the weight3and its rear end stopped against the stop plate61at the adjustment knob6.FIGS. 6 and 7show two different connection arrangements between the weight3and the reaction spring4.

When pressed the trigger e, the transmission mechanism d is forced to move the piston1backwards (seeFIG. 4). At this time, the weight3is forced backwards to compress the reaction spring4. When over the compression limit, the reaction spring4forces the weight3forwards, and the piston1is forced forwards by the piston spring11to strike the bullet, causing shooting of the bullet (seeFIG. 5). During forward movement of the weight3, a backlash vibration is produced, simulating a backlash vibration of a real rifle during firing of a bullet. Further, the user can rotate the adjustment knob6to adjust the spring force of the reaction spring4, thereby adjusting the level of the backlash vibration. When wishing to increase the level of the backlash vibration, rotate the adjustment knob6forwards relative to the buttcap spacer5to increase the spring force of the reaction spring4. On the contrary, when wishing to reduce the level of the backlash vibration, rotate the adjustment knob6backwards relative to the buttcap spacer5to reduce the spring force of the reaction spring4. Further, the buttcap spacer5can be removed from the receiver extension2for replacement of the internal component parts of the backlash vibration structure a.

As stated above, the invention provides a backlash vibration structure for toy riffle that has the following advantages and features:

1. Because the front end of the weight3is directly stopped against the rear end of the piston spring11, the piston1will never rub against any component parts of the backlash vibration structure a during its movement. Therefore, the piston1does not wear easily and is durable in use. Further, the weight3can be made relatively bigger than the prior art design, increasing the backlash vibration.

2. By means of the adjustment knob6, the user can adjust the level of the backlash vibration as desired.

3. The buttcap spacer5is detachable from the receiver extension2for easy maintenance and replacement of the component parts of the backlash vibration structure a.