Patent Application
20120288830
1. Technical Field
The field relates to non-lethal missiles for practice, controlling crowds and subduing individuals, and more particularly to triggers controlling timing of operation of grenade simulators and stun grenades.
2. Description of the Art
Stun grenades are typically hand thrown missiles which include a small pyrotechnic charge to create a flash of light and noise. Practice grenades may be similar in providing for generation of light and noise, but without the capacity for stunning. Unlike conventional grenades pyrotechnic triggers may not be preferred due to the potential for causing injury.
Woodall, U.S. Pat. No. 5,996,503 teaches a spring loaded ram for piercing a gas reservoir, a spring biased trigger lever which pivots to release the spring loaded ram and a “release activated delay” which delays operation of the device after release of the trigger lever. Woodall's delay mechanism is described as providing for temporarily restraining movement of the trigger lever by “resistive force provided between plunger face and end face.” The element temporarily restraining movement of the trigger lever is a resistance element which the bias spring urging the trigger lever outwardly must overcome.
Edison, II, U.S. Pat. No. 5,018,449, provides a trigger using a single driver spring for pushing a ram against a flexible paint bag. This spring is directly restrained by holding the trigger lever in place. Rotation of the lever is urged by the drive spring. Release the ram is delayed upon release of the trigger by an operator by inertia wheels.
Hammond, U.S. Pat. No. 1,179,301, illustrates a driver spring for an actuation rod which carries a catchment. The catchment is restrained by a shoulder formed on a trigger lever which is spring biased. The spring bias does not control rotation of the lever but instead relates to locating a slot in the lever on its fulcrum pin.
Fegley, U.S. Pat. No. 3,967,757 teaches a trigger lever with shoulder for restraining movement of a spring loaded gas cannister carrier.
A grenade simulator comprises a housing with an integral internal track. A carriage is mounted on the track for linear movement. A travel limit is provided at one end of the track to limit movement of the carriage on the track. A gas source is installed on the carriage. A drive spring installed between the carriage and the housing for urging the carriage against the travel limit. A time delay, multi-link trigger is installed on the housing for holding the carriage away from the travel limit until the multi-link trigger is released. A bayonet opens the gas source upon the carriage reaching the travel limit.
Understanding of the following description may be enhanced by reference to the accompanying drawings, wherein:
Referring now to the drawings
Referring to
Referring to
Multi-link trigger 24 comprises a handle 28 mounted for rotation on an axis of rotation 32 and a lever 46 mounted for rotation on a fulcrum 62. Fulcrum 62 is positionally fixed with respect within housing 12. Axis of rotation 32 may be positioned with respect to either housing 12 or to carriage 14. Here it is mounted to be carried by carriage 14. As viewed in the drawing the lower arm of lever 46 is configured to provide a shelf which serves as a latch 58 for a catch 60 installed on the end of drive spring 22 distal to seat 78. The opposite arm of lever 46 terminates in a cam follower 48 which rides against a cam formed into the adjacent portion of handle 28.
Carriage 14 carries a compressed gas cannister 64 which is oriented to allow an upwardly oriented bayonet 26 installed on the travel limit to impinge against a seal mounted in the gas cannister 64 and to open the gas cannister by ripping the seal. This initiates the flow of gas which inflates rupture bag 54 by a conduit (not shown). Carriage 14 also carries a switch 66 which closes (see contact probe 72 in
In
The operation and features of the multi-link trigger 24 are now considered in greater detail including use to provide a time delay. As previously described, handle 28 and lever 46 are mounted for rotation, handle 28 on axis 32 and lever 46 on fulcrum 62. One end of a handle bias spring 74 is connected to the handle at a point displaced from the axis of rotation 32 toward the cam 30. The opposite end of the handle bias spring 74 is connected to a fixed point relative to the housing 12, tending to pull the cam 30 end of the handle 28 downward, that is the handle rotates clockwise as viewed into the drawing.
Rotation of the handle 28 is constrained when it is desired to build into a delay into the trigger. Delay is controlled by incorporation of an escapement 34 which is engaged upon initial rotation of the handle 28 in the direction indicated by the letter A. Escapement 34 includes an anchor 40 which mounted to oscillate on an anchor pivot 76. Anchor 40 provides two spaced pallets 42 which engage in alternating fashion a section of an escapement wheel or “escapement arc 42” which depends from handle 28. In effect handle 28 has to step out of engagement with the anchor 40, which delays rotation of cam 30 into cam follower 48, and, accordingly, delays release of latch 58 from catch 60.
A lever bias spring is connected between the latch 58 of lever 46 and a point on the housing 12. The lever bias spring 56 urges withdrawal of the latch 58 and may be provided to overcome sticking between the latch 58 and catch 60. In addition, a bias spring may be used with the anchor 40 to bias rotation of the anchor in a particular direction to control delay timing. The delay may be adjusted by providing a handle 28 with a different moment of inertia or by selection of a handle bias spring 74 with a different spring constant.
