US3447417A

US3447417A - Gun with a floating breech bolt

Info

Publication number: US3447417A
Application number: US618595A
Authority: US
Inventors: Bruno Civolani
Original assignee: Benelli SpA
Current assignee: Benelli Armi SpA
Priority date: 1966-03-09
Filing date: 1967-02-27
Publication date: 1969-06-03
Anticipated expiration: 1986-06-03
Also published as: BE695019A; DE1553854B2; DE1553854A1; FR1513776A; GB1182454A; ES337702A1

Description

June 3, 1969 B. clvoLANl 3,447,417

GUN WITH A FLOATING BREECH BOLT Filed Feb. 27. 1967 I IIIIIAVIIII INVEN TOR BRUNO CIVOLA Nl United States Patent O 3,447,417 GUN WITH A FLOATING BREECH BOLT Bruno Civolani, Bologna, Italy, assignor to Benelli S.p.A. Divisione Armi, Viale Mameli, Italy, a corporation of Ital y Filed Feb. 27, 1967, Ser. No. 618,595 Claims priority, application Italy, Mar. 9, 1966, 5,172/ 66 Int. Cl. F41d 3/04 U.S. Cl. 89--182 1 Claim ABSTRACT F 'I'HE DISCLOSURE This invention relates to sporting guns and guns generally and relates more particularly to a special breech bolt arrangement in such guns.

The prior art fixed barrel guns have the disadvantage that prior to firing it is required to effect a manual adjustment of the gun which is necessary for prearranging 1t to stand the pressure which will be generated by the cartridge during explosion in order not to damage the breech frame duringrecoil and to facilitate the ejection of the cartridge case.

It is an object of this invention to obviate said disadvantage by providing a weapon by which it is possible to re safely and repeatedly any light charge or heavy charge cartridge with excellent results, Iwith a substantial reduction in recoil with respect to other guns and with a regular and easy ejection of the cartridge lease.

More particularly, the gun according to the invention is characterized in that it has the bolt head separated from the breech bolt with a spring loosely interposed therebetween.

The spring should be suitably designed to perform the following functions:

(a) to make the kick between the breech bolt mass and the bolt head elastic thus ydampening the recoil;

(b) to automatically adjust the unlocking of the locking system by providing a more or less long unlocking delay time in relation to the different pressures generated by cartridges having different charges.;

(c) to cause by its reaction the back movement of the whole breech bolt-bolt head system, enabling the eiection of the cartridge case and the subsequent reloading of the gun.

The invention will be more fully understood from the following detailed description, given merely by way of example and therefore in no limiting sense, of an embodiment thereof, referring to the accompanying drawing, in which:

FIG. l shows in a perspective view, partially in section, the portion of a sporting gun concerning this invention, with the breech bolt ready for iirng;

F'IG. 2 shows in a perspective view, partially in section, the portion of a sporting gun concerning this invention 3,447,417 Patented June 3, 1969 showing the relative positions between the breech bolt and bolt head due to the reaction to firing, and

FIG. 3 shows in a perspective view, partially in section, the portion of a sporting gun concerning this invention, with the breech bolt in the bolt head unlocking and recoil stage.

Referring first to FIG. l, a breech frame 7 is shown containing a bolt head 1 and a breech bolt 9 between which a helical spring 10 is loosely interposed. The bolt head 1 and the breech bolt 9 have an

axial bore

12, 13 respectively for providing a passage for the striker 14. The bolt head 1 has a recess 15 having a rounded end, in which a correspondingly rounded end 4 of a nib 3 seatingly engages. The latter ends at the other end with a foot 5 having four -

flat faces

16, 17, 18 and 19, whose function will be explained hereinafter. The face 16 is adapted to cooperate with a ramp 6 in the breech frame 7, the face 17 is adapted to cooperate with a fface 20 in a cavity 21 in the lower portion of the breech bolt 9, the face 18 is adapted to cooperate with a fa'ce 22 in the cavity 21 of the breech bolt 9 and the face 19 is adapted to cooperate with a face 8 in the cavity 21 of the breech bolt 9. The tiring hammer is shown at 23 and the cartridge chamber at 24.

In the position shown the bolt head 1 locks a cartridge 2 in the cartridge chamber 24 by means of the nib 3 acting as a push rod which engages at its rounded end 4 the corresponding rounded portion in the recess 15 and at its other end, by means of the face 16 engaging the ramp 6 in the breech frame. The gun is thus ready for firing.

After tiring, see RIG. 2, the whole gun recoils because of the pressure generated by the charge in the cartridge 2, the breech `frame 7 undergoes a sudden back movement whereas the mass of the mobile breech bolt 9, since it is not integral with the gun, opposes the shot by means of a kick causing the spring 10 to be compressed, thus dampening and delaying for a more or less long time depending upon the pressure of the cartridge charge, the recoil of the whole locking system. iDuring this stage the foot 5 of the nib 3 steadily contacts the ramp 6 in the breech frame 7 and is held in this position by the engagement of its face 19 with the face 8 in the cavity 21 of the breech bolt. As a result the bolt head is held locked against the cartridge chamber 24, as can be seen from FIG. 2.

After the spring 10 is compressed, to a predetermined degree because of the relative movement in opposite directions between the mobile breech bolt 9 and the bolt head 1 during the recoil of the whole gun, the spring, in the recoil subsiding stage, moves the breech bolt 9 rearwardly. During such movement, the face 22 strikes the falce 18 on the foot 5 of the nib 3 causing the face 16 to slide over the ramp 6 in the breech frame 6 until the face 17 on the foot 5 engages the face 20' of the breech bolt 9 (see FIG. 3) thus releasing the nib 3 from its engagement with the breech frame 7. The bolt head 1, because partly of the remaining recoil action and partly of the discharge gases, follows the breech bolt 9 in its back movement until the mobile breech bolt and bolt head assembly strikes against the rear portion of the breech frame 7 enabling a regular and easy ejection of the cartridge case.

While but one embodiment of the invention has been shown, it is obvious that a number of changes and modifications can be made. In particular, While the invention has been illustrated and described in its application to a sporting gun, it can nd application also in guns for armed forces.

I claim:

1. In a gun of the fixed barrel type, a breech frame having a firing chamber, a bolt head -within the frame, one end of said head closing said chamber and said end having a recess formed therein, said bolt head being formed with a cylindrical extension having a passage therethrough, a ring pin in said passage, a oating breech bolt slidably mounted within said 'frame and having a sleeve-like portion receiving the cylindrical extension of said bolt head and having also a passage aligned with said first named passage for receiving said ring pin, an inclined abutment formed on said breech frame, a locking nib within said frame having one end extending into the recess in the bolt head and the other end engaging said abutment to lock said bolt head in a forward ring position, and a spring interposed between said cylindrical extension and said breech bolt, said breech bolt and bolt head being relatively movable in opposite directions at firing of the gun due to recoil forces and the inertia of said breech bolt to compress said spring, the latter thereafter expanding during subsiding of the recoil forces to move said breech bolt in the opposite direction, and cooperating means on said breech bolt and said other end of the locking nib to release engagement between said other end of the nib and said inclined abutment to unlock said bolt head.

References Cited UNITED STATES PATENTS 676,094 6/ 1901 Linville et al. 1,109,910 9/1914 Eastwiek 89--182 X 2,365,389 12/1944 Browning 89-190 X 2,866,387 12/1958 Stern et al 89-190 X 2,890,626 6/1959 Amsler 89-180 FOREIGN PATENTS 511,084 8/ 1939 Great Britain. 429,241 1/1948 Italy.

BENJAMIN A. BORCHELT, Primary Examiner.

STEPHEN C. BENTLEY, Assistant Examiner.

U.S. Cl. X.R. 89-190