US20120288830A1

US20120288830A1 - Stun grenade with time delay trigger

Info

Publication number: US20120288830A1
Application number: US13/068,498
Authority: US
Inventors: David Van Zuilen; Thomas L. Fiechter
Original assignee: Ultra Electronics UnderSea Sensor Systems Inc
Current assignee: Ultra Electronics UnderSea Sensor Systems Inc
Priority date: 2011-05-12
Filing date: 2011-05-12
Publication date: 2012-11-15

Abstract

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 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. A release delay is integral with the multi-link trigger.

Description

BACKGROUND

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.

SUMMARY

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.

BRIEF DESCRIPTION OF THE DRAWINGS

Understanding of the following description may be enhanced by reference to the accompanying drawings, wherein:

FIG. 1 is a side elevation of a grenade simulator.

FIG. 2 is a perspective view of the grenade simulator of FIG. 1.

FIG. 3 is a cut-away view of the grenade simulator.

FIG. 4 is a cut-away view of the grenade simulator with a rupture bag undergoing inflation toward rupture.

FIG. 5 is a reverse perspective of FIG. 4.

FIG. 6 is a cut-away view of the grenade simulator after rupture of the rupture bag.

FIGS. 7-9 illustrate operation of a time delay multi-link trigger.

DETAILED DESCRIPTION

Referring now to the drawings FIG. 1 illustrates a grenade simulator 10. Grenade simulator 10 includes a cylindrical housing 12, sized to be easily grasped in a hand. The cylindrical housing is closed at one end by a hemispherical flash globe 50 and at the other end by a cap 52. A handle 28 is shown flush with housing 12 where it may be retained by a safety (not shown) or held in place by hand.
Referring to FIG. 2, the consequences of release of handle 28 of grenade simulator 10 are illustrated. Upon release of a hold on grenade simulator 10 handle 28 swings outwardly from housing 12. The movement of handle 28 initiates operations (described below) which result in a bright flash being emitted from flash globe 50 at one end of the housing 12 and the inflation until rupture of a rupture bag 54 at the opposite of the housing. Rupture of the rupture bag 54 releases a volume of air at a pressure calculated to generate a shock wave evocative of sound generated by an explosion. A flash of light from flash globe 50 is coordinated with the expected timing of the rupture to simulate the flash of an explosion. The flash globe 50 may be realized in various ways. A pyro-technic version could be based on a clear, break-resistant polycarbonate hemisphere which is charged with a pure oxygen atmosphere. Thin strips of aluminum or aluminum powder are suspended or stuffed into the hemisphere for ignition in the pure oxygen atmosphere. An “electric match” extends into the hemisphere to provide the ignition source. An external electrical circuit and switch connects the “match” to a battery to heat the match. Oxygen pressure can be varied on manufacturing to vary the illumination intensity generated by the flash globe. It is possible that alternative fuels/oxidizers may be employed. Alternatively the flash globe 50 may be based on electrical illumination sources.
Referring to FIG. 3 a cut-away view of grenade simulator 10 is shown. A time delay, multi-link trigger 24 provides a mechanical grenade actuator. The time delay element is based in part on an escapement 34 shown in FIGS. 7-9. Mult-link trigger 24 controls release of a carriage 14 which has a linear travel on a track 18. Track 18 is internal to and integral with housing 12 and longitudinally aligned in the housing. Track 18 comprises rods, stubs or poles set in a base disk or track travel limit 16 near one end of housing 12. Near the opposite end of housing 12 is a seat 78 for a drive spring 22 which is set between the seat and the carriage 14. Drive spring 22 is a compression spring and operates, when released, to urge carriage 14 away from seat 78 and against travel limit 16. Contact of carriage 14 with travel limit 16 initiates operation of the grenade simulator 10 to simulate an explosion. Multi-link trigger 24 functions to space the carriage 14 from the travel limit 16 and to restrain movement of the carriage toward the travel limit until the multi-link trigger 24 is released.
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 FIG. 7) upon closure of the carriage with the travel limit 16, sending a signal along wire 68 to ignite the contents of the flash globe 50. The function of a lever bias spring 56 which is coupled between the latch 58 end of lever 46 and a fixed point on the housing 12 is described below.
FIGS. 4 and 5 are perspective, cut-away views of grenade simulator 10 illustrating to greater advantage the location of compressed gas cannister 64 on carriage 14. A full quarter rotation of handle 28 has occurred, and carriage 14 has moved the full limit of its travel impinging against travel limit 16. Rupture bag 54 approaches the limit of its expansion before its catastrophic failure at a defined limit of expansion.
In FIG. 6 the condition of the grenade simulator 10 after use and rupture of rupture bag 54 is shown to illustrate operation of the device. Drive spring 22 has expanded pushing carriage 14 down by displacement of a catch extension 80 downwardly. Handle 28 has rotated by a quarter turn resulting in cam 30 having rotated against cam follower 48 displacing the cam follower arm of lever 46 toward drive spring 22. The opposite arm of lever 46 has rotated away from catch 60 releasing the catch from the restraint of latch 58.
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.

Claims

1. A grenade simulator comprising:

a housing;

a track integral to the housing;

a carriage mounted on the track;

a travel limit to movement of the carriage on the track;

an gas source installed on the carriage;

a drive spring installed between the carriage and the housing for urging the carriage against the travel limit;

a multi-link trigger installed on the housing for holding the carriage away from the travel limit until the multi-link trigger is released; and

means for initiating operation of the gas source upon the carriage reaching the travel limit.

2. The grenade simulator of claim 1, further comprising:

a release delay.

3. The grenade simulator of claim 2, the multi-link trigger further comprising:

a spring loaded handle mounted to pivot on an axis of rotation from a closed position to an open position and extending from the housing to be grasped;

a cam terminating one end of the handle;

a lever mounted for rotation on a fulcrum mounted to the housing;

a cam follower formed in a first arm of the lever, the cam follower being in contact with the cam; and

a latch terminating a second arm of the lever.

4. The grenade simulator of claim 3, further comprising:

the spring loaded lever being positionable with the handle in its closed position to allow location of the latch to restrain the drive spring with the carriage displaced from the travel limit.

5. The grenade simulator of claim 4, the release delay comprising:

an escapement including an escape wheel section mounted to the handle and an anchor mounted to engage the escape wheel.

6. The grenade simulator of claim 5, further comprising:

an air bag stored within the housing for inflation from the gas source.

7. The grenade simulator of claim 5, further comprising:

a flash source housed at one end of the housing in a light transmitting semi-globe.

8. The grenade simulator of claim 7, the flash source further comprising:

combustion configured aluminum in an oxygen enriched medium.

9. A time controlled release mechanism comprising:

a track;

a carriage mounted on the track;

a travel limit to movement of the carriage on the track;

a drive spring mounted with respect to the carriage and track for urging the carriage against the travel limit;

a lever mounted for rotation on a fulcrum attached to the track, a first arm of the lever having a latch for engaging the drive spring and a second arm of the lever including a cam follower;

a spring loaded handle mounted for rotation with a cam disposed on one end of the handle riding against the cam follower;

an escape wheel arc disposed on the spring loaded handle; and

an anchor mounted for oscillatory rotation and engaging the escape wheel arc.

10. The time controlled release mechanism of claim 9, further comprising:

a grenade initiator actuated by movement of the carriage to the travel limit.

11. The time controlled release mechanism of claim 10, further comprising:

the cam of the spring loaded handle urging rotation of the lever to move the latch from a position restraining the drive spring to a position releasing the drive spring.

12. The time controlled release mechanism of claim 10, further comprising:

a gas source mounted on the carriage.

13. A stun grenade comprising:

a spring biased initiator mechanism;

a lever mounted for rotation on a fulcrum, a first arm of the lever providing a latch for restraining the spring biased initiator mechanism and a second arm of the lever including a cam follower;

an escape wheel arc disposed on the spring loaded handle; and

an anchor mounted for oscillatory rotation engaging the escape wheel arc.

14. The stun grenade of claim 13, further comprising:

a gas source which the spring biased initiator mechanism initiates flow from upon release from the catch.

15. The stun grenade of claim 14, further comprising:

a flash source installed to emit light.

16. The stun grenade of claim 15, further comprising:

a rupturable airbag connected to the gas source for inflation upon initiation of flow.