US 2274195 A
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Description (OCR text may contain errors)
' Feb. 24,. 1942. G. H. GARRgsoN 2,274,195
FIREARM 2 Sheets-Sheet 2 Filed Dec. 3l, 1938 "i I V1 1 Iii.`
rg0 l rll """nlml INVENTQR George H. 6er/Afan Patented Feb. 24, 1942 FERERM 3 Claims.
This invention relates to improvements in rearms and particularly to improvements in the ring mechanism thereof.
In ring mechanisms for firearms as heretofore usually constructed an impact device, such as a striker or hammer, is provided, which device is spring urged to a position where it or a member actuated by it, such as a firing pin, strikes the primer of the cartridge. The impact device, is, when the arm is in condition for firing, held against the action of said spring by a holdingl device or sear, which engages a shoulder associated with the impact device. A spring is usually associated with the sear tending to hold it in position in the notch of the impact device. The relationship between the sear and the notch is usually such that there is a slight under cut and, in any event, the parts are so shaped that if the sear spring were removed, the force developed by the impact .device spring whether acting through an under cut construction or due to friction alone, will hold the sear in position Within the notch. In said constructions the sear spring (which may in some cases also be the trigger spring) is made comparatively light since the friction (or under cut) at the point of engagement of the sear with the notch is so great as to approximate the desired trigger pull.
Such constructions have distinct disadvantages, among whjch are:
(a) 'Ihe occurrence of "creep in the trigger action, viz., as the shooter increases the pressure of his nger upon the trigger preparatory to shooting, the trigger may suddenly move a short distance, without however initiating iiring. This creep is very disturbing to the shooter and interferes with accuracy; and
(b) Considerable trigger jump occurs, viz., as
the shooter gradually increases the pressure upon the trigger, the sear is finally pulled from the notch against the friction or the eiect of the undercut. When this has occurred, the only resistance to further movement of the trigger is the comparatively light sear (or trigger) spring. Therefore, the trigger moves backwardly a considerable distance frequently resulting in movement of the gun at the critical moment when firing is occurring.`
It is an object oi' the present invention to'provide improved impact firing device holding and releasing means so constructed and arranged that the trigger movement is entirely free fro creep and jump.
It is another object of the invention to provide such a means in which the movement of the mechanism which is so associated with the im? pact device (striker or hammer) that the driving spring for the impact device tends to move the holding means from its holding position, means being provided, as a strong trigger spring, to hold the sear in holding position against the action of the impact device actuating spring.
It is another object to provide a firing mechanism in which the holding means or sear is held against movement by the second holding means (or Sear-Sear) which, in turn, is held against movement by a third sear actuated by movement of the trigger.
Other objects will become apparent from the following description taken in connection with the attached drawings showing several illustrative embodiments of the invention and wherein:
Fig. 1 is a longitudinal sectional view of the receiver portion of a firearm illustrating the present invention, certain of the parts being shown in elevation;
Fig. 2 is a view of the bolt and associated parts, the left wall of the receiver having been cut away, the striker being shown in retracted position;
Fig. 3 is a cross-sectional view on the line III- III of Fig. 1;
Fig. 4 shows the striker, the rst sear, the second sear, and the trigger sear, in the position they will have immediately after firing has occurred;
Fig. 5 is a view of the parts shown in Fig. 1, the bolt handle being raised to cam the striker rearwardly and the bolt being drawn back to approximately its normal limit of movement, the trigger being shown drawn back so far as to free the bolt for removal from the receiver; and
Fig. 6 is a schematic view showing a modification.
Referring to said drawings, the numeral II in. dicates the barrel of a rearm attached to the receiver I2, as by screw threads I3. Said receiver in the form shown contains a generally cylindrical bore I4 within which is supported the usual bolt I5 for limited sliding Vand rotary motion. Said bolt is provided with a bolt handle IISV (see Figs. 2 and 3), connected to the sleeve I1 rotatably mounted upon the bolt between a shoulder I5a thereon and a sleeve I8. Housed within said bolt is a striker 20 having a ring pin 2|.
Said striker is formed with a, rear hollow portion within which is housed the striker spring 22, the forward portion of which bears against a spring stud 23 and the rear portion of which bears against an abutment pin 24, passing through an elongated hole 20a in the striker 20 and a hole in the bolt I5 and sleeve I8.
As shown in Fig. 2, the bolt handle sleeve I1 is formed with a cam slot I'ia into which extends a pin I1b mounted in the striker 20. With the striker in cocked position, as in Fig. 2, the pin I1b is free to move forwardly as the striker falls to explode the cartridge. It will be seen however that upon the opening (lifting) movement of the bolt handle I6, as by grasping the ball end I 6a thereof, the cam surface I1a will cam the pin I'Ib rearwardly and thus retract the striker to and beyond the position shown in Fig. l.
As seen in Fig. 2 and Fig. 3, the sleeve I'I is also provided with a cam ramp I1c which cooperates at times with a spring pressed plunger I9, the function of which will be referred to hereinafter.
The numeral 30 designates the primary sear, viz., the sear which initially holds the striker in position. The primary sear 30 is formed with Ia holding surface 30a lying in the line A-A. Said surface makes such an angle with the line from the point of engagement to the pivot pin 3|v of the sear that the action of the striker spring 22 tends to force the primary sear 30 out of engagement with the holding shoulder 20h on the striker.
A light sear spring 32 is provided which, in the form shown, act/s upon a pin 33 which tends to rotate clockwise the latch 34 serving to hold in -place the member 35 which may either be a box magazine, in the case of a repeating arm, or a block to be substituted for the box magazine, and which block serves to support a loading platform member 36. These devices are, however,
Vnot involved in the present invention.
The primary sear 30 is also provided with a downwardly extending foot 33h engaging upon the support surface 31a of the secondary sear 31 pivoted uponpin 33. It will be noted that p view of the lower co-eicient of dynamic friction the point of engagement of 30 upon 31 is quite close to the pivot thereof.
As striker spring 22 tends to rotate primary sear 3B clockwise its pressure upon secondary sear 31 tends to rotate it counterclcckwise, preferably against the action of a light spring such as the spring 31h. Secondary sear 31 also has a supporting surface 31C thereon which engages a cooperating surface 40a upon a tertiary sear which is pivoted at 4I and is shown as constructed integrally with the trigger 42. It will be noted that the surfaces 31e and 40a are inclined along the line B-B which again lies at an obtuse angle to the line from the point of contact to the pivot 4I so that rearward rocking of the member 31 will tend to rock the member 4I) downwardly, viz., counterclockwise about its pivot M. This movement, which corresponds to rearward movement of the trigger 42, is strongly resisted however by the powerful trigger spring 43 which bears upon a rearward extension 40h of the member 40 and bears at its upper end upwardly against an abutment 44, the vertical position of which is adjustable by screw 45 to permit adjustmentof the trigger pull.
It will be noted that the pin I9 which is biased downwardly by its spring I9a bears upon the member d, with the result that when the bolt handle is raised the cam I1c forces the pin I9 downwardly, thus pressing the member 40 downwardly against the action of the powerful spring 43 to permit the secondary sear 31 to move forwardly in front of the surface 40a when the gun is beingre-cocked.
Operation With the parts in the position shown in Figs. 1, 2, and 3, the arm is in condition for firing. The striker spring 22 is attempting to force the striker forward and on account of the angle of the shoulder 30a the primary sear 30 is biased downwardly, causing the foot30b to press upon the surface 31a on secondary sear 31, and biasing said sear counterclockwise. The pressure of its surface 31e upon the surface 40a of the tertiary sear or trigger sear 40 will, on account of the obtuse angle, tend to move the member 40 and trigger 42 counterclockwise, which latter movement is however resisted by the strong spring 43 which is set for the desired trigger pull. As the shooter gradually increases the pressure upon the trigger 42, nothing whatever occurs until he applies a pressure approximately equal to the thrust of spring 43. As this point is reached, the thrust of striker spring 22 acting through 30 and 31 becomes suiiicient, to overbalance the thrust of spring 43, and to rock surface 40a away from surface 31C so that surface 30a may rock away from surface 20h, thus suddenly releasing the striker 20 for firing. There is absolutely no trig- .ger jump because while firing is occurring there is no sudden release of the resistance to the pull of the finger upon the trigger and the movement of the trigger is so slight that it would be unnoticeable.
Furthermore, no creep is possible. It is well known that the co-eicient of static friction is greater than the co-eiiicient of dynamic friction, so that when the shooter has once applied suiiicient pressure to the trigger to permit the initiation of any movement whatever as between surfaces 40a and 31e, the movement will go on in so that creep is absolutely prevented.
The parts are now in the position shown in Fig. 4, the striker having engaged the primer portion of the cartridge and exploded the charge. It will be noted that in the form shown, the movement of the striker is very short to give the desired speedy action. In said position of the parts it will be noted that sear springs 32 and 31h are stressed, the energy therefor having come from the striker spring 22. The trigger sear 42, 40 returns to normal position in engagement with set screw 40e. In order to reload, it is necessary to lift the bolt handle. In so doing, cam surface I'Ia engages pin I1b and forces the striker 20 rearwardly to a position somewhat further back than that shown in Fig. 1. Since surface 30a can clear surface 2Gb, springs 32 and 31h will serve to move the sears 3D and 31 to the position shown in Fig. 1. However, spring 31h would not be suiiiciently strong to force the trigger sear 42, 40 downwardly as would be necessary for the end 31e to clear the end 48a. However, cam surface I1c has, in the meantime, engaged and pressed downwardly pin I9, which has forced the member 40 downwardly, thus enabling the member 31 to move forwardly in front of the surface 43a until arrested by the stop 30e, so that when the bolt handle is moved downwardly, the surface 31e will engage the surface 40a. ,Y
It will be noted that the member 30 has an upwardly extending horn 30e which serves as a bolt stop abutment with which engages the lug Ib of the bolt I5, `serving to limit the rearward excursion of the bolt in normal re-loading operations.
Fig. 5 shows how the bolt stop 30o may be withdrawn to permit removal of the bolt from the receiver. For this purpose the primary sear is also formed with a rearwardly extending horn 30d, located below the forward end of the tertiary sear member 40. When it is desired to remove the bolt, the trigger is pulled not only to the firing position but sufciently far beyond so that the member 3l)v is rocked clockwise to the position shown in Fig. 5 so that the horn 30o is removed from the path of the lug lib, thus permitting removal of the bolt.
While the surfaces 31e and 40a are shown Yso related that a rearward bias on memberV 31 tends to push the member downwardly, it is to be noted that this is not essential. In view of the leverage, the pressure of 31e against 40a is not very great so that the friction resulting therefrom is negligible.
Various other modifications are contemplated. For example, it may under certain circumstances be desirable to omit one of the intermediate members entirely, as in the form shown in Fig. 6. In said form there is only one member intermediate the striker 20 and the trigger sear. This is the member pivoted at 5I and formed with one or more projections 52, preferably in the form of gear teeth, engaging with appropriate depressions 53 in the striker 20. The member 5U has a surface 50a engaging with a corresponding surface a on the trigger sear 60 which is pivoted at 6| and is biased to the position shown by the powerful trigger spring 43. The surfaces '50a and 60a lie in the line C-C which forms an obtuse angle with the line passing through the pivot point 6I, the angle being such that, as in the form shown in Fig. 1, it is greater than the angle of repose. It will be seen therefore that if the shooter increases the pressure applied to the trigger suiciently to substantially overcome the force exerted by spring 43, the striker spring acting through member 50 will exert pressure at the surfaces 50a, 60a, thus camming the trigger sear 60 downwardly and permitting the striker to advance and strike the primer. During this time, the member 50 moves to the dotted line position shown. Upon reloading, when the bolt handle IB is raised, the striker is positively cammed rearwardly by the action of cam surface IIa upon pin Hb, thus positively moving the member 50 clockwise past and in front of member 60, camming said member downwardly the 5 slight amount required. This is made possible by the two-way connection between member 50 and striker 20. It will be seen that the trigger rocking pin I9 and the cam surface llc on sleeve l1 is not necessary in the form of Fig. 6; the trigger setting screw 40e or its equivalent is however required.
It will be noted that the constructions shown and described will serve admirably to accomplish the objects stated above. It is to be understood, however, that the constructions disclosed above are intended merely as illustrative of the invention and not as limiting as various modifications therein may be made without departing from the invention as dened by a proper interpretation cf the claims which follow:
1. In a firearm, an impact ring device, a spring tending to move said impact device to ring position, restraining means engaging said impact device, a second restraining means for said rst restraining means, a third restraining means for said second restraining means, said several restraining means having co-acting surfaces so constructed and arranged that'theithrust of the said spring tends to move said several restraining means to ineiective position, spring means for holding said third restraining means against the thrust of said impact device spring, and a trigger connected to compress said spring means upon actuation of said trigger, whereby said impact device spring may move said several restraining means to inelective position and cause said imsaid spring, a third restraining means pressed against said second restraining means by means of a spring, the co-acting surfaces of said second and third restraining means being so disposed that the second restraining means tends to move the third restraining means to ineiective position, and trigger means for at will overcoming the force of said last mentioned spring.
3. In a firearm', a striker, a spring tending to move said striker to firing position, restraining means engaging a shoulder on said striker, a second restraining means for said first restraining means, a third restraining means for said second restraining means, said shoulder and the co-acting surfaces of said several restraining means being so constructed and disposed that the thrust of the said spring tends to move said several restraining means to ineffective position, spring means for holding said third restraining means against the thrust of said striker spring, and a trigger connected to compress said second spring means upon actuation of said trigger, whereby said striker spring may move said several restraining means to ineffective position and cause said striker to move to firing position.
GEORGE H. GARRISON.