US3571961A

US3571961A - Firing mechanism with a rearwardly activated firing pin

Info

Publication number: US3571961A
Application number: US765433A
Authority: US
Inventors: Joel Lehtinen
Original assignee: Sako Oy
Current assignee: Sako Oy
Priority date: 1968-10-07
Filing date: 1968-10-07
Publication date: 1971-03-23
Anticipated expiration: 1988-03-23

Abstract

A firing mechanism in small arms of the type, which use miniature rifle cartridges which present an annular detonating fuse located in the rim of the cartridge case, includes a trigger and a movement transmitting device which cause the firing pin to strike the rim of the cartridge to set off the detonating fuse. The striking pin is directed from the front, and moves backwards to the rim of the cartridge case.

Description

Unite States Patent Joel Lehtinen Karhula, Jumalniemi, Finland 765,433

Oct. 7, 1 968 Mar. 23, 1971 0y Sako AB Riihimaki, Finland Inventor Appl, No. Filed Patented Assignee FIRING MECHANISM WITH A REARWARDLY ACTIVATED FIRING PIN 10 Claims, 1 Drawing Fig.

US. Cl 42/69, 42/ 1 Int. Cl F4lc 3/00, F4lc 11/02, F4lc 19/00 Field of Search 42/69, 69 (B), 1,] (G)-1 (K), 2; 89/1, 1.01; 227/9-l1 mar new.

[56] References Cited UNITED STATES PATENTS 2,099,993 1 H1937 Tauschek 42/1 2,931,039 4/1960 Henning et al.. 227/1 I 3,087,428 4/1963 Frech, Jr. 42/69 3,286,899 1 H1966 Seghezzi et a1. 227/ 1 0 Primary Examiner-Samuel F einberg Assistant Examiner-Charles T. Jordan Attorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: A firing mechanism in small arms of the type, which use miniature rifle cartridges which present an annular detonating fuse located in the rim of the cartridge case, includes a trigger and a movement transmitting device which cause the firing pin to strike the rim of the cartridge to set off the detonating fuse. The striking pin is directed from the front, and moves backwards to the rim of the cartridge case.

Known firearms present a firing mechanism located in the lower portion of the firearm, and a firing pin mechanism which is situated behind the cartridge housing breech. The firing mechanism and the firing pin mechanism are actuated in this order when the trigger is pulled. The two mechanisms comprise several parts which move in sequence upon pressing the trigger, until the firing pin strikes the rim of the cartridge. Because of the large number of parts included in the said two mechanisms and because these parts are spaced relatively far apart, the time taken for the firing pin to strike the base of the cartridge after the trigger has been pulled is relatively long. Attempts have been made to reduce as much as possible the time taken to complete this action since the hand of the marksman might move during said period, thus impairing the accuracy of the shot. The firing and firing pin mechanism in firearms used in competition, such as free pistols, have been developed to such an extent that it is no longer possible to shorten the period of time in question, when using these mechanisms.

The design of prior art firearms can be altered according to the present invention in a most surprising manner, so that with the exception of the firing pin no firing pin mechanism is needed at all. The present invention is characterized in that the firing pin is directed from the front, and moves backwards in such a way that it strikes the leading edge of the cartridge rim. In this way the firing pin is actuated immediately, by the firing mechanism. Since, pursuant to the spirit of the invention the number of moving parts are considerably reduced and since the trigger movement can be transmitted to the firing pin via a much shorter path than in the case of prior art firearms,

the time interval between the moment of pressing the trigger and the moment of impact of the firing pin is substantially shorter. During experiments it has been determined that this period of time has been reduced substantially in half. This means in practice that when using the firing mechanism according to the invention the cartridge has already left the gun barrel when the firing pin of a conventional firearm has only just struck the case of the cartridge. Owing to the small number of moving parts and their relatively small size, the mass is also considerably less than that of the mass of the prior art firearms. Consequently, the movements effected by the moving parts do not cause the firearm to move, which would otherwise impair the accuracy of the shot.

The invention will now be more fully described with reference to the drawing which illustrates a free pistol in section.

The drawing illustrates a firing mechanism in cocked position.

The firing mechanism comprises a bolt 11 which is securely threaded into a scar I, mounted in turn in a boxlike structure E3. The lower end of a catch member 2 mounted in the frame rests under the action of spring 12 in a recess in the upper end of the sear 1. Further, the left end of a lever 3, as seen from the drawing, mounted in said boxlike structure 13 is supported in a recess in the upper end of the catch member 2. A hammer 4 is supported to bear against and seat in a recess located to the right of the lever 3, as seen in the drawing; the said hammer 4 also being mounted in the structure 13. The right-hand end of the hammer 4 is actuated by a strong leaf spring 6, which acts to rotate the hammer 4 clockwise.

When the trigger or the end of the bolt 11 is squeezed inwards, the catch member 2 rotates clockwise, releasing the left-hand end of the lever 3. The hammer, loaded by the spring 6, then rotates the lever 3 counterclockwise. At the same time the left-hand end of the hammer 4 is released from the righthand end of the lever 3, and strikes heavily against the striking pin 5, which strikes against the leading edge of the rim of cartridge case it). The annular detonating charge within the rim, which is supported at the back by locking piece 15, fires the cartridge.

The firing mechanism is cocked by rotating the lever 7 counterclockwise. The lever 7 is mounted on the same pivot pin as the hammer 4. When the lever 7 is turned counter clockwise, front face of the lever 7 meets the pin 14 projecting from the side of the hammer 4 and the hammer begins to rotate counterclockwise thereby opposing force of spring 6. When the hammer 4 meets the right-hand end of the lever 3, the said lever 3 is rotated clockwise. When the left-hand end of the lever 3 snaps into the recess in the catch member 2 the firing mechanism is cocked. The pressure spring resting against the lower end of the lever 7 returns the lever to its original position.

The reference numeral 8 indicates a setscrew by means of which the pressure of the trigger movement can be regulated. if desired. The reference numeral 9 indicates a setscrew which supports the spring 6 after a firing sequence, and by means of which the action of the spring 6 can be adjusted against the rotary movement of the hammer 4, and thereby also the impact of the hammer against the striking pin 5. The reference numeral 16 indicates an ejector for the case 10 in the locking piece 15.

The present invention is not restricted to the embodiments shown and described but may be varied arbitrarily within the scope of the appended claims. It is obvious that the members which transmit the movement from the trigger I, 11 to the striking pin 5 can be arranged differently from the arrangement shown in the drawing.

lclaim:

l. A firearm for firing a projectile from a projectile carrying cartridge, said cartridge including a detonating rim having a front face, said firearm comprising a housing, means in said housing defining a cartridge chamber for containing said cartridge, said cartridge chamber having a longitudinal axis along which said projectile is ejected in a forward direction, a firing pin shiftably supported in said housing for engaging said front face of said detonating rim of said cartridge in a rearward direction substantially opposite of said forward direction, impelling means for impelling said firing pin, locking means for locking said impelling means in an energy stored condition in spaced relation relative to said firing pin, and releasing means for releasing said impelling means from said locking means such that said impelling means impels said firing pin for discharging said cartridge from said cartridge chamber.

2. A firearm as claimed in claim 1 wherein said impelling means includes a hammer pivotally supported in said housing, and means for urging said hammer rotatably toward said firing pin.

3. A firearm as claimed in claim 2 wherein said locking means includes a lever pivotally supported in said housing, said lever including opposite end portions, one of said opposite end portions being engageable with said hammer for releasably holding said hammer in spaced relation relative to said firing pin.

4. A firearm as claimed in claim 3 wherein said locking means further includes a catch pivotally supported in said housing, said catch including a portion engageable with the other of said opposite end portions of said lever for releasably holding said lever in a position for locking said hammer.

5. A firearm as claimed in claim 4 wherein said locking means further includes a spring interposed between said catch and said housing for urging said catch rotatably toward said other of said opposite end portions of said lever.

6. A firearm as claimed in claim 5 wherein said releasing means includes a scar pivotally supported in said housing, said sear including a portion engageable with said catch for rotating said catch away from said lever to free said hammer.

7. A firearm as claimed in claim 6 including means for cocking said firearm.

means, said locking means, and said releasing means are constituted by a plurality of pivotally supported nontranslatory members operatively coupled with one another.

Claims

1. A firearm for firing a projectile from a projectile carrying cartridge, said cartridge including a detonating rim having a front face, said firearm comprising a housing, means in said housing defining a cartridge chamber for containing said cartridge, said cartridge chamber having a longitudinal axis along which said projectile is ejected in a forward direction, a firing pin shiftably supported in said housing for engaging said front face of said detonating rim of said cartridge in a rearward direction substantially opposite of said forward direction, impelling means for impelling said firing pin, locking means for locking said impelling means in an energy stored condition in spaced relation relative to said firing pin, and releasing means for releasing said impelling means from said locking means such that said impelling means impels said firing pin for discharging said cartridge from said cartridge chamber.

6. A firearm as claimed in claim 5 wherein said releasing means includes a sear pivotally supported in said housing, said sear including a portion engageable with said catch for rotating said catch away from said lever to free said hammer.

7. A firearm as claimed in claim 6 including means for cocking said firearm.

8. A firearm as claimed in claim 7 wherein said means for cocking said firearm includes a further lever pivotally supported in said housing, said further lever including a portion engageable with said hammer.

9. A firearm as claimed in claim 8 wherein said further lever includes a further portion protruding outwardly from said housing for operator manipulation, and said releasing means further includes a member fixedly connected to said sear and protruding from said housing for operator manipulation.

10. A firearm as claimed in claim 1 wherein said impelling means, said locking means, and said releasing means are constituted by a plurality of pivotally supported nontranslatory members operatively coupled with one another.