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Publication numberUS3626621 A
Publication typeGrant
Publication dateDec 14, 1971
Filing dateFeb 25, 1969
Priority dateMar 5, 1968
Publication numberUS 3626621 A, US 3626621A, US-A-3626621, US3626621 A, US3626621A
InventorsIdo Chiyoki
Original AssigneeMiroku Firearms Mfg
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Percussion firing mechanism for a breech-loaded gun
US 3626621 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)


(IlllYUkl HM) Dec. 14, 1971 H|YQK| IDQ 3,625,621


(IIIIYUKI m0 United States Patent Oflice 3,626,621 Patented Dec. 14, 1971 PERCUSSION FIRING MECHANISM FOR A BREECH-LOADED GUN Chiyoki Ido, Kochi, Japan, assignor to Kabushiki Kaisha Miroku Seisakusho, Kochi, Kochi Prefecture, Japan Filed Feb. 25, 1969, Ser. No. 802,123

Claims priority, application Japan, Mar. 5, 1968,

43/ 13,848 Int. Cl. F41c 19/00 US. C]. 4241 2 Claims ABSTRACT OF THE DISCLOSURE A percussion mechanism in a breech loading gun where a percussion hammer is engaged with a sear which holds the hammer at full cock, where the direction of force of a preloaded spring bearing on the percussion hammer through a stirrup is closely located at the center of rotation of the percussion hammer and with the rotation of the percussion hammer in operating a trigger, the said direction of force moves away from the said center of rotation.

FIELD OF THE INVENTION This invention relates to a percussion mechanism in a breech loading gun characterized in that it usually is actuated by a percussion hammer held in a cocked position, and in firing it releases the engagement by pulling an interlocking trigger, reducing the engagement load of a sear which allows the action of the percussion hammer, and the engagement load of said percussion hammer being as small as possible, results in a decreased force of operating the trigger and reduces the time of releasing the said engagement in order to reduce the marksmanship error and to obtain enough striking power for a firing pin to fire a percussion cap.

SUMMARY OF THE INVENTION The idea of this invention exists in the improvement of a percussion mechanism characterised Where in the engagement status of the percussion hammer with the sear, the direction of force of a spring bearing on the percussion hammer is closely located at the center of rotation of the percussion hammer and the said direction of force moves away from the said center of rotation as the percussion hammer rotates when released by operating the trigger.

BRIEF DESCRIPTION OF THE DRAWINGS In the accompanying drawings in which the vertical sectional side views show an embodiment of the percussion mechanism of the gun in accordance with the present invention and is illustrated as follows:

FIG. 1 shows the mechanism before firing, and

FIG. 2 shows the mechanism after firing.

Referring to the drawing, a percussion hammer 2 is pivoted to be freely rotatable about a pin 2a in a breech block 1 of a breech loading gun, and its rear end 2b is in contact with a firing pin 5 fixed to a breech closure 4 by a screw bushing 3 and its front side is formed with a concave bearing 20 with which is engaged a stirrup 6b of the spring rod 6, the base 6a of which is located in the bearing hole 4a of the breech block 4 and operates to rotate the percussion hammer 2 in the direction of the arrow by a spring 7 preloaded on the said spring rod 6 between the breech closure and the stirrup 6b. In the lower part of the percussion hammer 2 is formed the engagement part 2d with which a sear 9 rotatably mounted on a pin 9a interlocking with a trigger 8 is engaged to maintain the cocked preparatory to firing position. Under the conditions where the direction of force of the spring 7 is in the operating line 12, in proximity to the line p, the rotating moment of the spring 7 on the percussion hammer 2 is small. Whereas, with the rotation of the percussion hammer 2 released from the engagement, the said direction of the line of force moves away from the rotation center 2a, the rotating'power of the spring 7 on the percussion hammer 2 is increased.

For cocking the breech block 1 to the firing position, a hand lever 10 is turned to the right hand side, permitting the opening of the gun barrel 11 which operates a percussion hammer lever 13 by means of a front base 12, said lever 13 being removably fixed to the gun barrel 11.

The percussion hammer lever 13 is rotated around a pin 13a and its percussion hammer lifting part 13b pushes up the percussion lever locking part 2d of the percussion hammer 2 which pushes the spring rod 6 and compresses the spring 7 to move it to the preloaded position. At the same time the end of the sear 9 engages the locking part 2d directly in advance of the cocked position. As a result even if the gun barrel 11 is closed, the percussion hammer 2 is locked by the sear 9 and holds the spring 7 in a preloaded position.

By operating the trigger 8 the sear 9 rotates about the pin 9a, releases the engagement of the sear 9 and releases the percussion hammer 2, which then rotates by means of the energy of the preloaded spring 7 and the rear end 2b of the percussion hammer 2 strikes the rear of the firing pin 5 to fire the percussion cap.

According to the present invention the line of force of the spring 7 is closely located to the rotation center 2a of the percussion hammer 2 under the condition of the hammer set in the cooked preparatory to firing position as stated above, so that the rotating power acting on the percussion hammer 2 is small and accordingly, the engaging load at the operating time of the sear is weak, so the required force to pull the trigger is reduced and there is negligible engagement wear and engagement damage resulting in longer life of the moving parts and increased accuracy in the firing of the gun.

What is claimed is: 1. A percussion mechanism in a breech loading gun comprising a breech blocking including a socket; a percussion hammer; a shaft; said hammer mounted pivotably on said shaft; a firing pin; said pin fixed to said breech block; said hammer having at its forward portion a concave recess; 7

a spring rod, a stirrup and an activating spring; the base of said spring rod being movably and pivotably located in said socket; said stirrup engaging said concave recess in said percussion hammer;

an engagement nose in the lower portion of said hammer;

a sear; said sear engaging said noise in the firing preparatory position;

said spring in the firing preparatory position being poised to move said stirrup in the direction away from the near center position of said shaft, the rear end of said hammer shaped to hit the said pin.

2. A percussion mechanism as claimed in claim 1, the end portion of said spring rod located wtihin said socket being tapered to permit limited pivotable movement of said stirrup, whereby in the firing position said stirrup and said rod are moved pivotably and forwardly tofollow the arcwise movementof said recess of said percussion hammer into an angular position below the center of said shaft of said hammer.

References Cited UNITED STATES PATENTS 368,401 8/1887 King 42-41 6 535,528 13/1895 Bye 42 41 612,313 10/1898 Deeley et al. 42-41 1,825,331 9/1931 Becker 42 -41 BENJAMIN A. BORCHELT, Primary Examiner C. TFIORDAN, Assistant Examiner

Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4447977 *Feb 1, 1982May 15, 1984Holmgren Steven AMulti-faceted firing device
US6405473 *Aug 18, 2000Jun 18, 2002Smith & Wesson Corp.Slide assembly for a firearm
US6640479Apr 6, 2001Nov 4, 2003Heckler & Koch GmbhHammer release apparatus
WO2000022367A1 *Oct 7, 1999Apr 20, 2000Beckmann RudiTrigger device
WO2002016855A2 *Jul 26, 2001Feb 28, 2002Smith & Wesson CorpA slide assembly for a firearm
U.S. Classification42/41, 42/69.1
International ClassificationF41A19/14, F41A19/00
Cooperative ClassificationF41A19/14
European ClassificationF41A19/14