US2868081A - Retractable firing pin - Google Patents

Description

Jan, 13, 1959 D. P. GROVER RETRACTABLE FIRING PIN Filed Aug. 29, 1956 INVENTOR. Dunuld EETUVET 77 g JAM 9- a. a); Q-

Z, ,981 Patented Jan. 13, 1959 RETRACTABLE FIRING P N Donald P. Grover, Chicago, 111., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Army Application August 29, 1956, Serial No. 606,940

2 Claims. (Cl. 89-9135) My application relates to an automatic gun provided with transversely displaceable cartridge chambers and more particularly to a retractable firing pin therefor having a variable cartridge contacting position.

Conventional guns of this type are subject to misfire due to inability of the firing pins to contact the primers of those rounds which are seated deeply in the drums. Also, the useful lives of the firing pins are short due to excessive wear and breakage by the firing pin wiping across the bases of the cartridge during movement thereof to and from the firing station.

It is an object of my invention to provide a firing pin for such a gun having a variable cartridge contacting position.

Another object of my invention is to provide the gun with a floating firing device including a firing pin which is retractable out of contact with the chambered cartridges during movement thereof to and from the firing station of the gun.

Other aims and objects of my invention will appear from the following description and the accompanying drawing in which:

Fig. l is an elevational view in section of a portion of an automatic gun incorporating an embodiment of my invention with the actuator in a rearward position and the firing pin and lever in normal positions;

Fig. 2 is a view similar to Fig. l with the actuator in a forward position contacting the lever and thereby biasing the firing pin forward into contact with the primer of the cartridge; and

Fig. 3 is a view along line 3-3 of Fig. 2.

Shown in the figures is an automatic gun provided with arecoil unit 12 which includes abreech member 14 and a rotatable drum 16 which is provided with a plurality ofchambers 18 for receivingcartridges 20 with such drum being disposed for successively carrying the cartridges to a firing station for discharge therein.

Since tolerances are allowed for machining and assembly of the gun and in the manufacture of the cartridges, the primers of the cartridges are disposed in drum 16 at depths within a predetermined range of values.

Anactuator 22 is disposed for reciprocation through the forces produced by the discharge of the cartridges 29 in the firing station and for engagement with drum 16 for rotation thereof to successively move thechambers 18 to the firing station and to retain the chambers in the firing station when the actuator is in the forward battery position. Afiring pin device 23 is mounted throughbreech member 14 for actuation into electrical contact withprimer 21 of thecartridge 20 which is in the firing station.Firing pin device 23 includes atubular housing 25 of material which will not conduct electricity, and afiring pin 26 and astriker 28 which are slidingly disposed in such housing. Asleeve 32 is slidingly mounted inhousing 25 forwardly ofstriker 28 so as to be engaged therewith and a return spring 30 is compressed between the front end of asleeve 32 and a bushing 54 mounted in the front end ofhousing 25 to biasLd striker 28 rearwardly into engagement with astop 24 fixed to the rear end ofhousing 25. Sleeve 32 includes ashoulder 34 which is engageable with aflange 36 on the rear end offiring pin 26 to limit the forward movement thereof respective to striker'28. The forward movement offiring pin 26, respective to housing 25, is limited by the engagement of a shoulder 52 on the firing pin with the rear end of bushing 54. Aposition spring 38 is disposed between firingpin 26 andstriker 28 to press such firing pin forwardly relative to the striker and the tension of such spring is arranged to be less than that of return spring 30 so thatsleeve 32 will remain pressed againststriker 28 when the firig pin is in its farthest cartridge contacting position, whereinshoulder 34 engagesflange 36, and so that the firing pin may be resiliently retracted withinhousing 25 through the contact of the forwardly projecting end of the firing pin withprimer 21 of thecartridge 20 in the firing station when such primer is disposed within the predetermined range of values.

Alever 40 is pivotally mounted at 42 onbreech member 14 and is biased rearwardly away therefrom by aspring 44.Lever 40 is engageable by anarm 46 resiliently mounted toactuator 22 when such actuator is in forward battery position and is arranged to be pivoted by such engagement againststriker 28 for forward displacement thereof against return spring 30 with firingpin 26 being actuated byposition spring 38 to the farthest cartridge contacting position thereof.

Firing pin 26 is connected through aspring contact 48 andcable 50 to a source of electric power for the dis charge.

' Thus, whenactuator 22 is in forward battery position and drum 16 is held thereby to retain one of thechambers 18 in the firing station,striker 28 is pressed forwardly against the bias ofreturn spring 36 by the engagement ofarm 46 withlever 40 and firingpin 26 is biased forwardly byposition spring 38 to contact the primer of thecartridge 20 disposed in the firing station.Firing pin 26 is slidingly disposed infiring pin device 23 for movement within a predetermined range of values, determined by the tolerances permitted in the manufacture of the gun and the cartridges 2%), to insure connection between such firing pin andprimers 21 of all of the chambered cartridges andposition spring 38 provides firm electrical contact between the engaged primers and such firing pin in all of the variable cartridge contacting positions thereof.

When thecartridge 20 in the firing station is fired by electric current passed thereto throughfiring pin 26 fromcable 50, the force of the discharge movesactuator 22 rearwardly and thereby disengagesarm 46 thereon fromlever 40 which is then free to be pivoted rearwardly byspring 34. Aslever 40 is pivoted rearwardly, return spring 30biases striker 28 rearwardly to the normal position thereof and firingpin 26 is retracted from engagement with the primer of the discharged cartridge so as to be out of contact with the base of this cartridge whendrum 18 is rotated during the remaining rearward travel of the actuator. When the followingchamber 18 is rotated to the firing station byactuator 22, during the return thereof to forward battery position, arm 66 engages lever 40 to actuatestriker 28 forwardly and thereby move firingpin 26 as hereinbefore explained into contact with the primer of the followingcartridge 20 after such cartridge is moved to the firing station.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. In an automatic gun including a recoil unit with a U1 stop, a member in the recoil unit provided with chambers for inclosing cartridges with the primers thereof disposed in the chambers at depths within a predetermined range of values and a firing station for the chambers for discharge of the cartridges therein, and an actuator disposed for reciprocation with respect to the recoil unit to engage the member and convey the chambers to the firing station through the forces produced by the discharge, a firing device comprising a firing pin in the recoil unit, a striker in engagement with said firing pin, a sleeve inclosing said firing pin, a return spring engaging said sleeve to bias said striker towards the stop and said firing pin to a position spaced from the primers, a position spring disposed between said firing pin and said striker to .bias said firing pin towards electrical contact with primers disposed in the chambers at the greatest depth of the predetermined range and a lever pivoted and biased to a normal position on the recoil unit, said lever being disposed for engagement between said striker and the actuator.

2. A firing device as described in claim 1 with a spring member disposed on the actuator for engagement with said lever.

References Cited in the file of this patent UNITED STATES PATENTS

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