US1849982A - Mechanism for firearms - Google Patents

Description

March 15, 1932. HI E HOWLAND 1,849,982

MECHANI SM FOR `FIREARMS l March l5, 1.932.

H. E. HOWLAND MECHANISM FOR FIREARMS F'iled May 7. 1931 s sheets-sheet 2 gwwmtoz 5 Sheets-Sheet .3

Filed May 7, 1931 Patented Mar. l5, 1932 HARRY E. HOWLAND, E ITHACA,v NEW YORK, ASSIGNOR TO ITHACA GUN COMPANY, 0E

ITHACA, NEW YORK, A CORPORATON OE NEW YORK i MECHANISIVI FOR FIREARMS Application led May 7, 19,31. Serial' No. 535,739.

The present invention relates to breech mechanisms for fire arms4 and` more particu-1 larly to the so-called pump gun type or in other words a gun having a tubular magazine carried directly under the barrel and which is operated for loading, extracting and. eject-` ing of the empty cartridge case of the reciprocation of a slide handle.

TheV entire breech mechanism is housed in a receiver which is closed on all sides but the bottom, through which the filling off the magazine and the ejection of the shell or empty cartridge case takes place.

The main parts of the breech mechanism 1 are the breech block with the, firing pin and extractor, the slide for reciprocating they breech blocln, the hammer, trigger, cartridge carrier and shell stop.

This invention forms a further development and improvement on the mechanism of the Browning Patent No. 1,143,170, manyV of the parts being' identical.

Some of the aims and advantages of this invention will here be enumerated:

rlhe breech block is pracldcallysolid with.

l incre, direct and therefore more eiective blow of the firingA pinv for igniting the cap in the cartridge case as compared with the slanting and less effective blow of the firing p-in in other guns.

l/Vi'th the diminishing of the cavities and cuts in the breech block and the substantially complete inclosure of the firing pin and its retracting spring, there will be practically no collection of dirt7 grit and dust thus easy and free movementl of parts is assured.

The extractor is quite small and stocky, Well balancedl and mounted to rock in a small recess provided on the;y under side off thebreech block l,near the forward end thereof. It has no cuts or recesses,Y and the coil spring, actuating it,I engages the; sho-rt tail-end thereof. As it is fulcru-medsubstantially in alinement with the bottom of the bore, it is ve-ry effective and has no; tendency of slipping oft' the cartridge rim in extracting.

The ejection downwardly of the ern-pty case or shell throu-gh `the bottom of the. carrier is,l on account ofthe solidly built extractor, very powerful and sure. A feature notseen in other guns is the firm gripl which the nose of the extractor has on the cartridge case rim after the slide has traveled rearward a short distance and at. the moment when the slide eng-ages the bottom lug of the breech block forl releasing the same from the abutment shoulder in the top of the r-eceiver. At this moment the extractor is lowered withthe breech block and the underside of the forward end of the entr-actor comes in Contact withthe forward cam surface of the slide thus locking the extractor with the rim of thel cartridge case.

To summarize, the; following are the main objects and advantages of the present invention (a) A dust and dirt proof mounting of the firing pin in the breech block.

(b) A firing pin completely enclosed in the breech block.

(c) A firing pin adapted to deliver an axial', direct (not slanting) blow against the cartridge case.

(d) A breech block having a straight axial bore to house the firing pin.

(e) A breech block having solid top, sides and ends with only one central bore and small bottom cuts to accommodate the eX- tractor and the slide lugs respectively.

A solid, substantially balanced, eX- tractor housed in the breech block in a; small arched roof 29.

recess at the forward end thereof on its under side. Y

(g) An extractor also serving as cartridge ejector to expel the cartridge through the bottom of the receiver.

(h) An extractor positively gripping the cartridge rim actuated by a cam surface on the slide at the moment when the latter engages the bottom lug of the breech block for releasing it from the shoulder in top of the receiver.

In the accompanying drawings one embodiment of the invention is illustrated, and

Figure l shows a vertical, longitudinal section of the receiver and breech mechanism with the parts in position immediately after firing; .Y

Figure 2 is a view similar to Figure l, but with the breech block partly retracted and all moving parts in elevation instead of section; f

Figure 3 is a view similar to Figure l, showing the breech block full retracted;

Figure 4 is a transverse section taken alongVV line 4 4 of Figurey 3;

Figure 5 is a plan View of the slide; and

Figure 6 is a side elevation of a detail in section. f-

Like reference characters refer to the same parts in the different views.

Some of the parts are similar or identical with those shown and described in Patent 1,143.17() of which this invention forms a further improvement and they` are accordingly not claimed here. They are however necessary for cooperation with new and improved parts. Such known parts are the hammer and its mainspring and intermediate parts, the trigger, trigger-guard, slide and slide stop or safety sear, carrier and cartridge strop, etc.

Reference numeral 25 indicates the receiver which is closed on all sides except the bottom 26. It has two fiat side walls 27, 28 and an At its forward end is secured the barrel 30 and beneath the same the tubular cartridge magazine 31 preferably by interrupted threads. The receiver is` at its rear end secured in usual manner to the stock 32 which, together with the trigger guard 33 completely closes the rear end of the receiver. The trigger guard is secured between the side walls 27 and 28and extends forward in .the bottom opening. 26 of the receiver 25 set to prevent the pulling of the trigger accidentally.

A slide stop 4l is also pivoted on the pin 35 and, actuated by a coiled spring 42, engages the rear end of the slide 43, when the mechanism is in firing position, thereby preventing the opening of the mechanism in case of hang-fire. The slide 43 is guided in grooves 44 cut in the sides 27 and 28 of the receiver and parallel to the gun axis thereby permitting straight reciprocation of the slide actuated by the loading handle (not shown) on the magazine through the intermediary of the operating rod or slide-bar 45. The latter is connected tothe slide by means of a pin 46 securedtherein.

Soon after starting on its rearward movement, the slide 43 with its recess 47 engages a corresponding lug 48 provided on the under Y side of the breech block 50.

Unlike former constructions, the breech block consists of a practically solid piece of metal with flat sides and an arched top surface. At its rear end is provided an upstanding lug or projection 5l which engages a corresponding recess 52 in the top of the receiver whenthe block is in its iiring or forward position, see Figure l. The rear face 53 is slanting backwards and constitutes an abutment shoulder for the breech block taking up the blow from the firing. In this position, the top face of the breech block is parallel with the bore of the barrel 30 and the axis of the firing pin 54, which is housed in the breech block, is in exact alinement with the axis of the gun bore. The firing pin is cylindrical throughout with a firing pin point 54 of small diameter and the rear'end 55 of large diameter thus forming a shoulder 56 for the retracting spring 57 wound around the firing pin point 54 and abutting against the forward wall of the firing pin seat 58.l The firing pin has a limited movement in its seat governed by a transverse pin 59 in the breech block, engaging a slot 60 in the rear heavy end 55 of the firing pin. Thus, when not driven forward by the hammer 38, to puncture the cartridge case cap, as seen in Figure l, the rear end 55 of the firing pin projects a short distance beyond the straight rear face of the breech block, see Figures 2 and 3. The drilled hole running through the solid` breech block forming the seat for the tiring pin, constitutes a dust and dirt proof enclosure for the same.`

This `is of great importance, because upon the easy and perfect working of the firing pin depends to a great extent the correct functioning of the entire firing mechanism.

On the underside of the breech block 50, near its forward end is pivoted on a small pin 63 the short extractor 54 almost at its middle so as'to practically balance itself. A small recess 65 is milled out of the breech block forming a seat just large enough to permit a slight oscillation of the extractor. Its nose 66 is formed as. ahoolr for engaging: the rim of the cartridge case and its tail 67 is engaged by a compression spring 68 lodged in a drilled hole in the breech block. Said spring thus tendsv to press the tail downwardly, thus swinging the nose 66 upwardly for engaging the cartridge case rim 69. Cvpposite the seat is cut out another recess 70 to accommodate the extractor which projects slightly below the bottom of the breech block. The special function of this recess 70 will be described later.

Forward of the lug 48 to the seat 65, the bottom portion of the breech block 50 is cut away as at 73 in order to permit the rearwardly slanting cam surface 74 of the slide recess to engage the correspondingly inclined forward surface 75 of the lug 48 on the breech block during the rearward or opening move` ment thereof.

In its firing position, as seen in Figure 1, when the breech block engages with its projection 51 in the receiver recess 52, then the bottom face of its lug 48 rests on the rear end of the slide 43, while the cam surfaces 74 and 75 are separated. Directly the slide 43 be gins to move rearwardly the cam surface 74 approaches the cam surface 75 of the lug 48 and after only a short travel, the said surfaces become engaged and after a further movement of the slide the lug 48 is compelled to travel downwards into the recess 47 of the slide. This causes the rear end of the breech bloclr te tilt downwards until the projection 51 becomes disengaged from the receiver recess 53 and the breech block 50 is free to move rearwards with the slide 43.

With the breech block moves also the extractor 64 which with its nose 66 engages the rim 69 of the cartridge case after only a slight rearward movement of the breech block and actuated by the spring 68. The lowering of the breech block as regards the slide also causes the underside of the forward end of the extractor 64 to abut against the bottom of the forward recess 70 in the slide 43 in this manner creating a firm, unyielding grip, on the cartridge case 76. The latter is thus drawn out of the bore as indicated in Figure 2. How the carrier 77 pivoted at 78 in the receiver 25, is swung upwards from its middle position, seen in Fig. 1, to its uppermost position, seen in Figure 2, by the action of the breech block 50 during its retraction, forms no part of the present invention, but is fully described in the above named Browning patent. On the inside of the carrier arms are provided a pair of small abut-ments 79 engaging the upper portion of the cartridge rim 69 when the cartridge case has been still further retracted. As the cartridge case thus meets with an obstruction while the extractor tries to draw the case further back,

5 the cartridge case will be swung downwards with it-s open end first until it ultimately drops away from the extractor and falls through the bottom opening 26 of the receiver 25.

The rearmost position of the breech block and slide is shown in Figure 3 when the rounded rear end 80 of the slide 43 engages the tail 81 of the carrier 77 lifting the same thereby causing the forward arms of the carrier to descend, ksee Figure 3, in position to receive the next cartridge case from the magazine. The carrier and its operation form no part of the present invention, but is fully described in said Browning patent. Similarly the operation of the positive stop 82 pivoted at 83 in the receiver and other parts assisting in feeding a new cartridge case into the bore, also form part of said Browning patent and need therefore no further description here.

The hammer 38 fulcrumed at 85 in the trigger guard 33, is forced down and cocked by the rearward movement of the slide 43, which is facilitated by its slightly rounded front face as at 84. rIhe cocling of the hammer talres place against the main spring 86 through the intermediary of the strut 87 which is hinged in the hammer 38 at 88, when finally the latter reaches its position shown in Figure 3, where the trigger 34 engages the hammer notch 37. As however the slide swings back the hammer slightly more than necessary for such engagement a small tooth 89 on the hammer engages under a sear notch 90 provided on the slide stop 41 which thu-s acts as a safety sear. This hammer mechanism is also similar to the said Browning mechanism, as already stated.

lVhen the breech block and slide have been brought forward by the action of the loading handle through the rod 45 into iring position, the gun can then be tired in the usual manner by pulling the trigger.

I claim 1. In a tiring mechanism for guns having a downwardly openreceiver, the combination with a straight liring pin, a substantially solid breech block reciprocable in the receiver and provided in closed position with a longitudinal bore coaxial with the axis of the gun barrel and forming a fully dust proof housing for the firing pin in all positions, and means in said bore adapted to retract the point of the iring pin into the bore.

2. In a firing mechanism for guns having a receiver, the combination with a substantially solid breech block having an axial bore, a slide adapted to actuate said block and reciprocable in the receiver, a small recess Jeing formed on the underside of the breech block, a short solid extractor having a short nose portion and a short tail portion and pivoted in said recess and substantially balanced therein, below said bore, and means for actuating the extractor to grip the rim ico of thel cartridge case, said means comprising a spring in said recess engaging said tail portion and a cam surface on the slide cooperating with said nose portion.

8. ln a iiring mechanism for guns having a receiver, the combination with a substantially solid breech block, a slide reciprocable in the receiver, and adapted to engage the breech block to partake in such reciprocation, a small recess being formed on the underside of the breech block, a short solid extractor pivoted in said rec-ess, and means for actuating the extractor to grip the rim of the cartridge case, a cam surface on the slide cooperating with said gripping means to irml ly hold the extractor during retraction of said slide.

4. ln a firing mechanism Jlor guns having a receiver, the combination with a. substantially solid breech block, having an axial bore, a slide reciprocable in the receiver, and adapted to engage the breech block to partake in such reciprocation; a short extractor pivoted in the breech block below said bore, a cartridge carrier pivoted in said receiver and actuated by the slide to raise a cartridge into loading position, shoulders on said carrier positioned in the path of an empty cartridge case extracted by said extractor, said extractor and abutments cooperating to swing said cartridge case downwardly thereby ejecting the same through an opening in the bottom of said receiver, and means for actuating the extractor to grip the rim of the cartridge case.

5. In a tiring mechanism for guns having a downwardly open receiver, the combination with a straight firing pin, a substantially solid breech block, a slide reciprocable in the receiver adapted to actuate the breech block, said breech block being provided with a longitudinal bore forming a dust proof housing for the tiring pin, means in said bore adapted to retract the point of the firing pin into the bore, a small recess being formed on the underside of the breech block, a short solid extractor pivoted in said recess below said bore, and means onfthe slide for actuating the extractor to grip the rim of the cartridge case.

6. In a firing mechanism for guns having a receiver, the combination with a substantially solid breech block, a slide reciprocable in the receiver and adapted to engage the breech block to partake in suoli reciprocation, a firing pin, the breech block having a longitudinal bore forming a dust proof housing for the firing pin, the iii-ing pin being adapted to deliver a blow in axial direction against the cartridge case cap; a recess being formed in the underside of the breech block below said bore, a solid extractor' pivoted in said recess and substantially balanced therein, means actuating the extractor to grip the rim of the cartridge case, a cam surface on the slide cooperating with said gripping HARRY E. HOWLAND.

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