US1789308A

US1789308A - Apparatus for rifling gun barrels

Info

Publication number: US1789308A
Application number: US208313A
Authority: US
Inventors: James L Hatcher
Original assignee: Individual
Current assignee: Individual
Priority date: 1927-07-25
Filing date: 1927-07-25
Publication date: 1931-01-20
Anticipated expiration: 1948-01-20

Description

Jan. 20, 1931. J. L. HATCHER APPARATUS FOR RIFLING GUN BARRELS Filed July 25, 1927 Patented Jan. 20, 1931 UNITED STATES JAMES L. HATGHER, OF WINCHESTER, VIRGINIA.

APPARATUS FOR RIFLING GUN BARRELS Application filed July 25, 1927. Serial mi. 208,813.

(GRANTED UNDER THE ACT OF MARCH 3, 1883, AS AHENI JED APRIL 30, 1928; 370 0. G. 757) The invention described herein. may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

Thisinvention relates to an apparatus for rifling gun barrels and the like.

The recent development of a type of iron and steel alloy generally designated as stainless or unstainable has resulted in proposals to employ it in gun barrels because its physical properties of high resistance to wear and erosion are admirably suited to this purpose. 1

This type of steel however possesses certain mechanical properties which are exhibited in its capacity for flowin and work hardening and because of this di culties are presented in rifiing a gun barrel by the customary machining operation.

end of the cutting tool produces a grinding rather than a cutting action the foregoing mechanical properties are reflected in a tendency of the metal to push ahead and bank up in front of the tool and also in a tendency to form a hardened skin which will resist cutting. If this trouble is to be avoided'by the exercise of every possible precaution the cutting operation would be extremely slow due to the hardness of. the metal and it would be so necessary to frequently interrupt the work for the purpose of tempering the metal.

Accordingly it is proposed in the present' invention to form the riflin by a cold Workv operation which will not on y permit simul- 23 tane'ous formation ofthe riflin in a number of barrels but will serve to raise the elastic limit of the metal. The apparatus employed in carrying out theinvention is characterized by a novel arrangement designed to hold a -1 tool bar against bending as it is forced into the barrel.

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

tool holder Fig. 2 is an end view thereof; I

Figs. 3 and 4 are detail views; respectively in side elevation and plan of the rifling mem- Since the foremost Referring to the drawings by numerals of reference. I The apparatus employed in conducting the coldwork operation includes a hollow supportor holder 5 formed with a plurality of equally spaced parallel guide-Ways 6 in which the. bars 7 carrying the rifling members 8 are reciprocally mounted.

The guide-ways are circular in form corresponding in diameter to the bore of the gun barrel and all of them are provided with'a slot 9 opening into the bore of the support and extending substantially throughout the length of thesupport in order to provide for movement of a ram 10 Whose extremities fit in the guide-ways.

The rifling members 8 are revolubly mounted on their bars and'are each provided with' spiral ribs 11. As these members are forced' through the bore of the barrel the ribs ng substantially throughout its length, bars mounted in the guide ways, rifling members revolvably carried on one end of the bars and a ram mounted for sliding movement in the guide-ways and engageable with the other end of the bars.

JAMES L. HATCHER.

Fig. 1 is a view in side elevation of the