US1858498A - Bolt operating mechanism for machine guns - Google Patents

Description

J. L. HATCHER Filed April 22. 1931 I llwlzlwllm. Llamas 1-7.. at: E1"

ATTORNEY May 17, 1932.

sour OPERATING MECHANISM FOR MACHINE GUNS Patented May 17, 1932 hdSdAtd FATE @FFEQE JAMES L. HATOHER, on THE UNITED slnrns ARMY, wrnonns'rnn, vrne n n Application filed April 22, 1931.

Serial No. 531,972.

(GRANTED UNDER THE ACT OF MABGE 3, 1883, AS AMENDED APRIL 30, 1928; 370 O. 757) The invention described herein may he manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalt there- This invention relates to a bolt operating mechanism for machine guns.

Machine guns are provided with a bolt handle to permit manual retraction of the bolt in order to reproduce the action of the gun mechanism during firing for the purpose of initially loading the gun and correcting stoppages. Then agun is mounted, as in aircraft, so that the bolt handle is inaccessible to the gunner, an auxiliary operating mechanism is provided.

The operating mechanism of the present invention is of the rigid slide bar type having a pivoted handle arranged to act as a lever in raising the bar from its latch-plate and in initially retracting the bar when the gun barrel is locked to the bolt. The bar is also provided with a fixed handle to replace the handle normally provided on the bolt stud of the gun.

lVith the foregoing and other objects in view, the invention resides in the novel arrangement and combination of parts and in the details of construction hereinafter (lee scribed and claimed, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

A practical embodiment of the invention is illustrated in the accompanying drawings, wherein:

Fig. l is a view in side elevation of a machine gun equipped with the improved bolt operating mechanism.

Fig. 2 is a plan view of Fig. 1.

Fig. 3 is a. sectional View on the lines 38 of Fig. 2.

Referring to the drawings by numerals of reference There is shown the side plate 6 of a machine gun having a longitudinally extending slot 7 in which the stud S of the breech bolt reciprocates during actuation of the gun. Secured to the side plate at either end of the slot are front and rear brackets 9 and 1Q for supporting and guiding a slide bar 11 parallel to and directly below the slot '2',

A collar 12 (Fig. 3) secured to the bar 11 by means of a threaded pin 13 is formed with an upstanding finger 14 engageable with the forward face of the stud 8 so that rearward movement of the bar will retract the stud 8 and the bolt of the gun while forward movement of the stud will return the slide bar, A, handle 15 fastened to the pin 13 by means of a pin 16 replaces the handle that is usually provided on the stud 8.

The slide bar 11 extending a short distallfle beyond the rear bracket 10 and fitting into the bifurcated upper portion of a handle 1? is secured intermediately of the ends of the handle by apivot pin 18. A roller 19 also fitted in the bifurcated portion and secured by a pivot pin 20 at one end of the handle above the pivot pin 18 normally engages a curved cam surface 21 on the rear bracket 10. This surface constitutes a support for the roller and serves as a fulcrum for the handle when the latter is acting as a lever.

The pivotally mounted handle is maintained in a predetermined position by means of a stop pin 22 and aspring-pressed plunger 23. The pin 22 is fixed in the handle and engag h pper surface of the slide bar while the plunger 23 bears against the under? cut rear face 2% of the slide bar and works in a downwardly inclined recess 25 in the handle. The plunger normally tending to rotate the handle downwardly is opposed by the stop-pin 22. Upward rotation of the handle is limited by contact of the face 241 of the bar with the handle.

The under side of the slide bar is provided with spaced recesses or notches 26 and 27, the rear recess 26 being engaged with the latch-plate 28 of the rear bracket 10 when the slide bar is fully forward as shown in Fig. 1, and the front recess 27 being engage able therewith when the slide bar is retracted for the purpose of holding the stud 8 and its breech bolt in the retracted position. Spaced fiat springs 29729 carried on the upper side of the slide bar each overlie one of the re.- GBSSBS and are adapted to engage the rear bracket to depress the slide bar and insure engagement of the recesses with the latchplate.

A collar on the slide bar adjacent its rear end is arranged to engage the lower portion of the rear face of the bracket 10 to positively limit forward movement of the slide bar.

In the normal automatic operation of the gun the slide bar remains in the forward position and the bolt stud 8 reciprocates freely in rear of the finger lt. When it is desired to manually retract the bolt by means of the handle 17, the handle is grasped and pulled rearwardly. Since the slide bar is locked against rearward displacement by virtue of the engagement of the recess 26 and latch plate 28, the effect of the rearward pull on the handle will be to rotate it about its pivot 18 and cause the roller 19 to ride up the cam surface 21 thereby bodily raising the handle and the slide bar which is attached to it until the bar is arrested by engaging the rear bracket. At this point the roller supported by the rear bracket comes into play as the fulcrum of a lever and the continued rearward pull on the handle serves to smoothly initiate retraction of the slide bar and the bolt of the gun which at this time is being unlocked from the barrel. From then on the handle functions merely as an attachment on the slide bar whereby complete retraction is efiected.

At the end of the rearward stroke of the slide bar the front spring 29 will act on the rear bracket to depress the bar and .efiect engagement of the recess 27 andvlatch plate 28 unless an upward pressure is exerted. Consequently the tendency of the slide bar to be automatically held in the retracted position may be overcome at the will of the operator.

The handle 15 provided intermediate the length of the slide bar is more conveniently employed when the operator is, not in a favorable position to pull back on the handle 17.

I claim:

1. The combination with a machine gun having a reciprocating bolt and bolt stud, of a front and rear bracket secured to the side of the gun, a slide bar reciprocally mounted in the brackets, a finger on the slide bar en gageable with the forward face of the bolt stud, and under side of the slide bar provided with spaced recesses for engagement with the rear bracket, springs on the upper side of the slide bar overlying the recesses and engageable with the rear bracket to depress the slide a bar, and a pivoted handle on the slide bar adapted to fulcrum on the support.

2. Mechanism for manually operating the bolt of a machine gun including supporting means securable to the gun, a slide carried by the supporting means and engageable with the bolt stud, a handle pivoted intermediate its ends to the slide and having limited movement relative thereto, a springpressed plunger mounted in the handle and acting on the slide to normally rotate the handle to one limit ofits movement, a'roller on one end of the handle, a cam surface on the supporting means against which the roller normally bears when the slide is fully forward.

3. Mechanism for manually operating the bolt of a machine gun including supporting means securable to the gun, a slide carried by the supporting means and engageable with the bolt stud, a handle pivoted intermediate ment relative thereto, means for maintaining the handle in a predetermined position with respect to the slide bar, a roller on one end of the handle, a cam surface on the supporting means against which the roller normally bears when the slide is fullyforward. a. Mechanism for manually operatingthe bolt of a machine gun including supportingmeans securable to the gun, a slide recip-' rocally mounted in the supporting means, and engageable with the bolt, means for latching the slide against reciprocation, a handle pivi oted on therear end of the slide, and an inclinded fulcrum against which one end of the handle normally bears when the slide is fully forward. 2

5. Mechanism for manually operating the bolt of a machine gun including supporting means securableto the gun, a slide reciprocally mounted in the supporting means, and engageable with the'bolt, means for latching theslide against reciprocation, and means on the slide cooperating with the supporting means for unlatching the slide and initiating retraction of the slide. a

6. Mechanism for manually operating the bolt of a machine gun including supporting means securable to the gun, a slide reciprocally mounted in the supporting means, and engageablc with the bolt, means for latching the slide against reciprocation,and means on the slide cooperating with the supporting means for unlatching the slide.

7. Mechanism for manually operating the bolt of a machine gun including supportin means securable to the gun, a slide carrie by the supporting means and engagcable. with the bolt, and means on the slide fulcrumed on the supporting means in initially retracting the slide.

JAMES L. HATCHER.

80 its ends to the slide and having limited move- 7

Images