US2947220A - Single trigger sequential firing mechanism - Google Patents

Description

Aug. 2, 1960 c. F. L AAGr-:R

SINGLE TRIGGER sEQuEN'rIAL FIRING MECHANISM Filed Jan. 23, 1958 III Il; /l/lfllillillll fihi.

FIG.2.

1N V EN TOR. CRESTON E LAAGER 2,947,220 l"vitaliteitAug-v 251960 SINGLE TRIGGER SEQUENTIAL FIRING MECHANISM Creston F. Langer, Beverly, NJ., assgnor to the United States of America as represented by the Secretary f the Army Filed Jan. 23, 1958, Ser. No. 710,825

1 Claim. (Cl. 89-1) (Granted under Title 35, U.S. Code (1952), sec. 266) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment of any royalty thereon.

This invention relates to trigger mechanisms such as are adapted to fire explosive charges utilixed in the operation of aircraft escape systems. More particularly, it relates to an improved mechanism which is operated by one motion of a single trigger to determine the charge to be fired and to cock and release the tiring pin of the selected charge.

As hereinafter explained, this arrangement has the very important advantage over those heretofore proposed that it positively insures that the explosive charges are fired in the proper order and does away with certain mechanical devices, such as cables, pulleys and rods, which have not been altogether reliable in operation.

Currently used in high speed airplanes are escape devices which jettison the canopy and catapult the pilot away from a disabled craft. These devices depend for their motivation upon the energy released by an exploding cartridge. The device jettisoning the canopy is known as the remover. That ejecting the pilot is called a catapult. Each contain powder charges and each is tired by gas pressure generated by a device known as an initiator. The initiator generates gas when a cartridge contained within it is red by actuating its tiring pin manually.

Two separate initiators are customarily used and each is fired separately by the pilot. Present installations utilize cables, pulleys and various other mechanical devices. Some are diicult to operate under some circumstances. Others have failed and resulted in loss of life because of the nature of the operating rigs. It has been possible, for example, to re the catapult before the remover with the result that personnel was projected through the canopy. All these difficulties are avoided by the present invention which is of relatively simple construction and positively insures that the initiators are tired in the proper order.

The invention will be better understood from the following description when considered in connection with the accompanying drawings and its scope is indicated by the appended claim.

Referring to the drawings:

Fig. 1 is a sectional view of a preferred form of the invention, and

Fig. 2 is a section taken on the line 2-2 of Fig. l.

The mechanism of these figures includes a trigger which has a removable cover 9 and is an integral part of a member 11. This member is slidable along a rod 12, is biased to its illustrated position by a spring 13, and

2. has pivoted to it a pawl 14 which is biased to its illustrated position by a spring 15. The pawl 14 is arranged to cooperate with a four lobed cam i16 which is fixed to a gear 17. This gear is revolved degrees by one stroke of the trigger 10. l

The gear 17 bears a pin 17 which is arranged to en gage one end of a sear 18. This sear rides on a rocker 19 which permits it to angle away from engagement with the pin 17' when it has been moved a predetermined distance by counterclockwise rotation of the gear 17 It should be understood that this action is facilitated by the arrangement of the lower end of the scar 18, which at one side is sloped and connected to a spring 21 and at the other side is bifurcated to straddle the firing pin 20 and offset to engage a notch near the top of the firing pin. Thus the member 19 maintains the sear 18 in engagement with the ring pin 20 during the initial movement of the scar. When the lower end of the member 19 engages the offset part at the lower part of the sear however, the lower end of the sear is released to the point where it is moved to the left by the spring 21 and is disengaged from the firing pin 20 which is thereupon activated by the spring 22.

This one stroke of the trigger 10 functions through the pawl 14, the cam 16, the gear 17, the sear 18, the rocker 19, and the spring 21 to compress and release a spring 22 which provides the energy for firing a primer 23. As previously indicated, the primer 23 is a part of an initiator 24 which is connected through a exible tube to the tiring pin of the canopy remover and generates a gas for activating this firing pin. This action leaves the sear 18 out of engagement with the gear 17 so that this gear is now rotatable independently of the sear.

Meshing with the gear 17 is a second gear 25 bearing a pin 26 adapted to engage a sear 27 of a mechanism by which an initiator 28 in the same manner as that described in connection with the firing of the initiator 24.

The initiators 24 and 28 are of a well known type wherein a firing pin piston is surrounded by a seal ring 29. Each of them is adapted to fire a cartridge 30 for generating a gas under pressure which is applied through a port 31 and a tube (not shown) to the tiring pin of a cartridge which activates the canopy remover or the catapult.

Obviously, more than two initiators can be similarly fired by the addition of more gears and pins. The described mechanism has the additional advantage that it permits a second firing in the case of a mislire of the catapult, since a fourth pull of the trigger again brings the pin 26 into engagement with the sear 27 I claim:

In an apparatus for generating a gas pressure and for applying said gas pressure to a device to be operated, the combination of a support, a pair of initiators fixed to one end of said support with their longitudinal axes parallel to one another, each of said initiators having a tiring pin, a spring biasing said ring pin to its uncooked position, a gear, a sear extending between and releasably coupled to said gear and said ring pin, said sear having a surface which is flat adjacent said gear and is offset adjacent said firing pin, a rocker arm pivoted to said support and having relatively long and short arms and a spring tensioned to maintain said arms in engagement gear and from said firing pin when said relatively shortnu arm engages the offset part of said surface, the gears of said initiators being in mesh with one another, actuating means including a pawl biased into engagement with one of said gears, said actuating means being mounted at the other end of said support and being movable transversely of said longitudinal axes for alternately ring said initiators, and means for returning said actuating Y' leerhe-ncesl Cited in the le of this patent means to its original positionafter each of its movements. 10 2,902,788

ITD STATES PATENTS Granger July 28, 1891 Kilgore July 27, 1909 Stanley Sept. 21, 1954 Polny Feb. 15, 1955 Martin Feb. 28, 1956 Foster Jan. 21, 1958 Laager Sept. 8, 1959

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