US1028430A - Shotgun. - Google Patents

Description

ccLUMBlA PLANOGRAPH ED..WASHINGTDN. D. c.

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FRANK F. BURTON, OF EAST HAVEN, CONNECTICUT, ASSIGNOR TO VINCHESTER REPEATING ARMS CO., OF NEW HAVEN, CONNECTICUT, A CORPORATION.

SHOTGUN.

Loeaaso.

To all whom t may concern Be it known that I, FRANK F. BURTON, a citizen of the United States, residing at East- Haven, in the county of New Haven and State of Connecticut, have invented a new and useful ImprovementI in Shotguns; and I do hereby declare the following, when taken in connection with the accompanying drawings and the characters of reference marked thereon, to be a full, clear, and eX- act description orn the same, and which said drawings constitute part of this application, and represent, in

Figure l a broken view partly in elevation, and partly in longitudinal section of a shot-gun barrel constructed in accordance with my invention. Fig. 2 a similar view showing a paper-shell cartridge in position in the barrel. Fig. 3 a detached view in side elevation ot a paper-shell cartridge. Fig. et a. view corresponding to Fig. 1, but showing the cartridge-chamber of the barrel treated throughout its length in accordance with my invention. Fig. 5 is a broken view, greatly enlarged, of a portion of such a nurling tool as may be employed in practising my invention. Fig. 6 a sectional view on the line a-Z) of Fig. 5. Fig. 7 a broken view, greatly enlarged, showing a portion of the surface produced upon the interior walls of the cartridge-chamber by the action of the nurl. Fig. 8 a broken perspective view of Fig. 7.

YVhen paper-shell cartridges were :lirst invented and put upon the market only black powders were in use. 0n ignition these powders produce relatively low pressures and consequently cut-offs, so called, were so rare as to be practically negligible. By cut-offs7 I mean the shearing of the paper tube of a paper-shell cartridge from the sheet-metal cap of the shell along the line of the edge of the cap where the paper and metal come together. lWhen a cut-0E occurs the sheet-metal cap is extracted in the usual manner, but the largest portion ot the tube remains, stuck in the cartridgechamber of the gun-barrel and can be eX- tracted only with diiiiculty and often not without the expenditure of precious time. Frequently the tube lett in the cartridgechamber is so firmly adhered to the walls thereof that it can be removed only by a hook. With the advent or" smokeless powders which produce higher pressures than Specicaton of Letters Patent.

Application filed March 21, 1912.

Patented June d, 19112. serial no. 685,346.

black powders, cut-oifs became so frequent as to be a source of great annoyance. Consequently the problem of avoiding cut-otts became one of the most serious problems connected with the manufacture and use of what the trade knows as paper shell ammunition. A variety of expedients were resorted to for the correction of this diiiiculty. None of them have been more than measurably successful; some of them have been attended with considerable eXtra eX- pense; all of them have attempted to solve the problem by some modification of the shells themselves.

The object of my invention is to prevent cut-Otis, not by changing the Aconstruction of paper-shell cartridges, but by modifying the construction of the gun barrel itself.

With these ends in view, my invention consists in a gun having the walls of the cartridge-chamber of its gun-barrel formed with a plurality of anchoring-pockets to anchor the sheet-metal caps of paper-shell cartridges at the instant of tiring to prevent the said caps against longitudinal rearward movement and separation from the paper tubes of the shells.

In carrying out my invention as herein shown, the rear portion of the interior walls of the cartridge-chamber 2 of the gun-barrel 3 are subjected to a nurling or swaging or other equivalent forming operation for the production of a gripping surface consisting of a great number of regularly arranged tapering anchoring pockets d isolated from each other by ridges 5 intersecting each other at or about right angles. The pockets 4 may be varied in depth, in specilic form and amount of separation from each other, all depending upon the particular character of t-he tool used to produce them upon the highly polished rear portions of the walls of the cartridge-chamber; but whatever their specific shape and arrangement, and number, and however produced, they must be adapted, in order to function in accordance with my invention, to sufiiciently receive portions of the sheet-metal cap 6 of a paper-shell cartridge in the chamber 2, to anchor the said cap 6 and rmly hold it against longitudinal movement rearward, whereby the cap is prevented from being torn away from the projecting portion of the paper tube 7, along the edge 8 forming the mouth of the cap, it being understood that the pressures produced by the firing of the cartridge operate to instantly force portions of the cap into the anchoring pockets 4 formed in the walls of theV cartridgecliainber as described. 1 may further say that the high pressures produced by smokeless powders at the time of ignition and eX- plosioii expand both the sheet-metal cap G and the paper-tube T of the cartridge and force their exterior surfaces into intimate contact with the inner surfaces of the cartridge-chamber 2. These high pressures also tend to force the sheet-metal cap 6 of the cartridge rearward, and unless this tendency of the cap to be moved rearward is effectually resisted, the cap will move rearward and be torn away from the paper-tube T along the edge 8 of the cap. In short a cutoff will result. The cap will then be free to be extracted as usual, but the tube will be left in the cartridge-chamber 2 to be extracted by itself by such means as the user of the arm can devise. I should also explain in this connection that the breech-closures of the guns in which paper-shell ammunition is used may be slightly opened before the pressures have entirely expended themselves. It is this remaining pressure tending to push the cap G rearward that, generally7 speaking, tears the metal cap away from the paper tube. By providing the cartridge-chamber 2 with a sufficient number of anchoring pockets 4, as described. I ani able to anchor the cap at the time of firing and so entirely control the position of the cap at the time of firing and until after the pressures have spent themselves.

1n the gun-barrel shown in Figs. 1 and 2 of the drawings, the interior walls of the cartridge-chamber 2 are lled, so to speak, with anchoring pockets 4 from the rear end of the chamber 2 forward for a distance approximately corresponding to the length of the longest metal caps used in this class of cartridges, which, as is well known, have metal caps varying in length according to the load. By extending the pitted surface far enough forward to cover the longest metal caps used, the gun will be adapted to prevent cut-offs in the use of paper-shell cartridges having metal caps from the shortest to the longest. The cartridge shown in Fig. 3 has a metal cap 6 of the maximum length. 1f desired, the pitting of the interior walls of the cartridge-chamber of a gun constructed in accordance with my invention, may be carried forward of the point indicated by metal caps of maximum length even to the forward end of the paper tube, as shown by Fig. e, in which the cartridge-ehamber 9 of the gun-barrel 12 has its walls provided with pockets 13 throughout the entire length of the chamber, but I have found that the provision of the rear portion of the cartridge-chamber with pockets of the character described, effectually prevents the rearward movement of the caps at the time of firing, and meets all of the requirements of avoiding what are known to shooters as cut-offs.

1n Figs. 5 and 6 I have shown enlarged views of portions of such a nurl or swaging tool l-Lt as might be used in practising my invention. It will be seen that itis the cameo of which the surface produced by it is the intaglio.

I claim A gun having the walls of the cartridgechaniber of its gun-barrel formed with a plurality of anchoring-pockets to anchor the sheet-metal caps of paper-shell cartridges atV the instant of firing to prevent the said caps from longitudinal rearward movement and separation from the paper tubes of the shells.

1n testimony whereof, I have signed this specification in the presence of two subscribing witnesses.

FRANK F. BURTON. `Witnesses:

Dimmi. H. VEADER,

F RANK A. PAUL.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

Washington, D. C.

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