US2242496A

US2242496A - Sear mechanism for firearms

Info

Publication number: US2242496A
Application number: US160321A
Authority: US
Inventors: David M Williams
Original assignee: Individual
Current assignee: Individual
Priority date: 1931-02-07
Filing date: 1937-08-21
Publication date: 1941-05-20
Anticipated expiration: 1958-05-20

Description

Original Filed Feb. 7, 1931 2 Sheets-Sheet l 2 Sh'eetSf-S'heet 2 May 20, l941.` D. M. WILLIAMS SEAR MECHANISM FOR FIREARMS Original Filed Feb.' 7, 1931 iii Patented May 20, 194i Original application February 7,

Divided and this Z1, 1937, Serial No. 160,321

Claims.

The present invention relates to an improvement in rearms, and particularly to searmechanisms therefor.

One of the objects of this invention is to provide a novel arrangement for the sear and trigger mechanism such that an vindependent operative means furnishes the motive power for disengaging the scar from the striker mechanism of the gun.

In the sear disengaging means, as usually provided, in the prior art, the trigger is directly coupled or indirectly coupled by means of some lever arrangement to the sear and a pull on the trigger serves to disengage the sear from the striker and fire the ann. It is obvious, therefore, ,that the trigger pull on this type of gun, had to overcome not only the spring tending to retain the trigger in its normal position, but also had to provide suicient force to disengage the sear from the striker. As is well-known in the art, the notch in the striker mechanism which is normally engaged by the sear, may take various shapes and usually, a very positive engagement of the sear and striker is desirable in order to prevent any accidental discharge of the rearm. In the event a deep notch is provided in the striker to be engaged by a shoulder on the sear or vice versa, the force of a strong striker spring acting on this deep notch engagement would result in a very heavy trigger pull. In some cases, it may even give rise to what is known in the art as a drag or trigger creep. In other words, the very opposite of the crisp trigger pull, which is desirable.

In the gun mechanism, in accordance with the present invention, a separate scar-releasing spring is provided which is suitably tensioned by some movable part ofthe gun and is arranged to be released by the trigger. In other words, a manual pull on the trigger does not furnish the motive power for the sear release. This power is furnished by a separate operative mechanism or spring, which is automatically tensioned during the operation of other parts of the gun mechanism.

The present invention is shown particularly applied to a gun of the automatic or self-loading type; however, it is obvious that it may be applied with certain minor modications to a gun which is manually operated, such as the ordinary conventional lever or bolt action rifle. As before pointed out, the salient characteristic of the present invention is to provide a separate operative mechanism or separate spring for disengaging the sear of the gun and it is largely 193i, semi No. application August inmaterial as to just gun nism In the present invention, the opening movement of the bolt serves to perform this function, but it is obvious that by a suitable arrangement of parts, this tensioning eiect could be obtained either by some other portion of the gun mechanism or by some other movement of the bolt.

One of the objects of the present invention, therefore, is to provide a gun having a uniform, light and crisp trigger pull.

A further object of the invention is to provide an actuating spring operative to disengage the sear.

It is a further object of the invention to provide an operating spring suitably tensioned by a moving part of the gun mechanism and Whose stored up energy is operative to disengage the sear.

Still another object of the invention is to provide a spring operative upon the sear to disengage the same, which is tensioned by a movable part of the gun mechanism and released bythe trigger mechanism. y

Other objects of the invention will appear from thefollowing disclosure and drawings illustratlng the invention.

Figure 1 is a longitudinal section of a gun in accordance with the invention, the gun mechanism being shown in the closed position ready to re.

f Figure 2 is a longitudinal section similar to l what moving part of the functions to tension this operating mecha- Figure 1, with the gun mechanism being shown in open position assumed after ring.

Referring to Figure 1, the gun comprises a receiver I carrying a barrel 2 having a rifle bore 3. The gun carries the usual stock secured in the usual manner by screws and 5, and is provided with a guard indicated as an entity by numeral G. Positioned within the receiver I is a bolt l having at its forward portion a projecting member 8 adapted to engage a vibrator 9. 'I'he bolt I is apertured centrally at I0 to receive a portion of the bolt mechanism cooperating therewith, the lowest Wall of the bolt being slotted at I I from the aperture to its periphery, this aiording means for inserting the scar mechanism in said slot II of the bolt 1. It is understood that the bolt 'I is provided with the usual handle or other means for a. manual operation, not shown. Mounted within the forward portion of the bolt aperture I0 is a striker I2 provided with a striker point I3 adapted to engage the rim of the cartridge I4 and prime or fire the same. Mounted adjacent the rear end of the aperture I8 is a striker spring compressor element I5. The forward end I8 of the element I5 has a sliding relation with the rear portion of the striker member I2. Confined within the striker member I2 is a spring I1 bearing at its front end on the forward wall I8 of the striker, and at its rear end on the front end I8 of the compressor element I5.

Mounted in the rear end of the receiver plug 26 is an ejector 2l serving to guide the bolt spring 22 encasing the elector rod at. its rear end. The plug 28 -is recessed at 23 for the purpose of seating the head 24 of the ejector 2|. I'his head 24 is provided with a key 25 to prevent rotation of the ejector 2|. The spring 22 is seated at its rear end against'the face 0f the ejector head 24 and its front end in the forward wall of the spring compressor well. 26 indicates a retaining plunger for locking the receiver plug 28 against rotation.

lMounted in the forward end of the slot IVI is a cooking lever 21 pivotally mounted on a pin 28 carried by the bolt, and adapted to engage the striker cam 23. There is also positioned in the slot Il a sear 38, pivotally'mounted on a pin 3I carried by the bolt. The sear 38 is provided with a notch 32 adapted to engage a corresponding notch 33 vin the striker I2. 'I'he rear portion of the sear 30 is provided with lingers 34 adapted to engage a finger 35 on the sear lever 36 pivoted on a pin 31 carried by the bolt.

'I'he sear lever 36 vis urged into the direction equivalent to sear engaging position by a spring 35a, which is suitably mounted in theXbolt, as.

shown in the drawings.

'Ihe guard 6 comprises a trigger mechanism and magazine catch. Referring to the trigger mechanism, there is provided a trigger 38 pivotally mounted on a pin 38.

Slidably mounted in an aperture 4I) in the trigger 38 is a :trigger plunger 4I cooperating with a pawl 42 adapted to engage a set 1ever 43. The lower end of the plunger 4I is apertured to receive a spring 44 which urges the slidable plunger in an upward direction. The set lever 43 is pivotally mounted at. 45 and is provided with a lug 46 adapted to engage tail piece 41 of the sear lever 36.

It may be noted by referring to the drawings that the sear lever 36 and the sear 38 are so mounted and dimensioned yas Ito provide an inclined lower face 36a to the sear lever. particularly true when the sear is disengaged from the striker as shown in dotted line position, in Figure 1.

The gun is provided with the usual box magazine 48 and mechanism to hold the same in place. The magazine 48 is provided with a recess l48 adapted to engage a serrated finger piece 58.

These serrations are shown at 5I. The fingerl piece 58 is provided with a projecting member 52 adapted to engage a recess 53. The finger piece 58 is apertured at 54 to receive a plunger 55 pivotally mounted at 56.

The forward end 51 of the plunger bears against a spring 58. Mounted in the fiooi platev 58 is a set spring holder 68 carrying a set lever. spring 6I. Mounted in the top portion of the set lever spring is a. plunger 62 having a ball point 63 adapted rto engage a socket 64 in the set lever. The floor plate catch 65 pivotally mounted on pin 65 engages oor plate 58 at 61 to locate the oor plate. The iioor plate catch 65 isheld This is amasar I in position by means ofthe spring 68. The floor plate catch 88 is recessed at 68 to provide a seat for pawl plunger 18 actuated by the spring 1I.`

The spring 1I functions topush the plunger 18 against the pawl 42. 'I'he pawl 42 is provided with a hook 12 adapted to engage the portion 13 of the stirrup 14 of the set lever 43. The set lever paw! 42 is engaged at the point I5 by the end 18 of the plunger 18.

It may be noted here that in connection with the trigger mechanism there is a safety mechanism having a bow indicated by fthe reference numeral 11, which will not be described in detail, as it is intended to be more adequately described in another application.

The trigger mechanism is provided with means for making adjustments with regard to the trigger pull, or the amount of engagement of pawl hook 12 and portion 13. To effect the adjustment, there is provided an adjusting screw 18 which abuts against an adjusting lever 18, which has a tail piece 88 and projecting therefrom, a forward or upper portion, not shown, which abuts against thev pawl 42. It may, therefore, be seen that when the tail piece is pushed in an upward direction by movement of the screw 18,

' that the pawl 42 will be moved to the right, and,

therefore, the hook 12 will have a shorter engagement with the portion 13.

As before pointed out, plunger 4I is slidably seated in the trigger 38 and is urged to an up; ward position by means of a spring 44. The upper portion of plunger 4I has a cam shoulder .8I contacting the pawl 42 at the point 82 to provide a camming action which eliminates any back lash or looseness with respect to the trigger 38 and the pawl 42, and yforces the pawl 42 in close contact with the finger 83 of the trigger 38. The trigger 38 is held under tension by means of aV plunger 84 and plunger spring 85 mounted in adjusting lever 18.

Referring to Figure 1 of the drawings, the gunis shown in a closed position ready to fire. Cartridge I4 has been fed in a suitable manner and is in the chamber ready to re. Striker spring I1, bolt spring 22 and sear actuating spring 6I are all under tension. 'I'he sear shoulder 32 is in engagement with the notch 33 on the striker and restrains the same from moving forward.

Upon apull of the trigger, pawl 42 is moved in a forward direction to the dotted line position as shown in Figure 1, disengaging hook 12 from the portion 13 of set lever 43. Set lever 43 then moves in an upward direction to dotted line position about the pivot 45 under the 4action of spring 6I 'I'he lug 46 integral with the set lever, therefore, is moved in the upward direction, in turn moving tail piece 41 of the sear lever in an upward direction to dotted line position against the action of spring 35a. 'I'he rear portion of sear lever 36 is, therefore, moved in an upward direction about the pivot 31 and the front portion and finger 35 of the sear lever therefore, moved in a downward direction. The nal position of sear lever and 1sear are also shown in dottedlines in Figure Since the linger 35 on the sear lever engages fingers 34 on the sear, the sear 36 is, therefore,

moved in a downward direction, swinging aboutinfluence of striker spring I1 to iire the cartridge.'

. The action of the latter augmented by the action 0f the gas on the vibrator 8, serves to drive the bolt l to an open position, as shown in Figure Z. This action tensions the striker spring Il through the action of cooking lever 21 on striker cam 29 and also tensions bolt spring 22. During the backwards motion of the bolt, the inclined face 36a of sear lever 36 carried by the bolt, pushes lug $6 in a downward direction and tensions spring Si through lever $3. 'Ihe depression of lever $3 during the backward or opening movement of the bolt, is best seen in Figure 2, wherein set lever 53 is shown in its lowermost position, and spring 6| is shown fully compressed.

In this position, portion 13, carried by the set lever Q3 is also in a position to be engaged by hook 12 carried by the pawl $2. Pawl 62 is urged into an engaging position by pawl plunger l actuated by spring 1l.

The bolt is now forced to a fully closed position under the action of spring 22; however, the tension on the striker spring and the sear actuating spring 6| is not fully relieved during this closing action of the bolt due to the engagement of the pawl hook 12 and portion i3 and the engagement of the sear and striker notches 32 and 33. Since the tension on the sear actuating spring 6| is not fully relieved by the closing action of the bolt, it may be noted that the possessed stored up energy for moving the sear, as hereinbefore set forth and the pull on the trigger is a relatively light one determined by the amount of engagement of portion 13 and hook 12.

This application is a division of my prior application, Serial No. 514,252, filed February 7, 1931.

I claim:

1. In a bolt-action firearm, the combination with the bolt-unit thereof, of a spring-pressed ring-member; a sear serving to releasably hold the said firing-member in its cocked position; a trigger controlling the said sear; spring-means urging the said sear into position to hold the said firing-member in its cocked position; and second spring-means constructed and arranged to be tensioned and relaxed by the movement -of the said bolt-unit and serving when tensioned to move the said sear into position to release the said ring-member when the said trigger is operated.

2. In a firearm having a movable bolt, a spring-pressed ring member, a sear serving to releasably hold the said firing-member in its cocked position, a set lever constructed and arranged to move said sear to release said ringmember, a trigger including means coacting with said set lever to releasably hold the same in position to prevent the movement of the sear by said set lever, 'and spring means urging said set lever into position to move said sear to release the ring-member, said spring means being constructed and arranged to be tensioned by movement of the said bolt.

3. A sear mechanism for rearms, including in combination, a spring-pressed firing-member, a sear serving to releasably hold the said iringmember in its cocked position, a trigger including means coacting with the said sear to releasably hold the same in position to restrain the said firing-member, a plunger and a spring urging said plunger to move the said sear into its firing-member releasing position when the rearm is cocked, so as to release the said firingmember when the said trigger is operated and means to automatically render said spring operative when said rearm is cocked.

4. In a gun having a movable bolt, a ring CFI 3 mechanism, a sear constructed and arranged to hold said tiring mechanism in cocked position, a relatively weak spring urging said sear to holding position, a second relatively strong spring urging said sear to a released position, a trigger mechanism for preventing the movement of the sear by said second spring, and means to tension said strong spring simultaneously movable with said bolt.

5. In a gun, a ring mechanism, a sear constructed and arranged to hold said firing mechanism in cocked position, a relatively weak spring urging said sear to a holding position, a second relatively strong spring urging said sear to a releasing position, a movable bolt mechanism carrying a cam surface constructed and arranged to tension said second relatively strong spring, and a trigger mechanism for preventing the movement of the sear by said second spring when tensioned.

6. In a gun, a striker having a notch, a spring for actuating said striker, a sear having a portion constructed and arranged to seat in said notch to hold said striker in cocked position, spring means urging said sear into seated position, a second spring means urging said sear to a releasing position, means to tension said second spring, an automatically movable bolt, means on said bolt for operating said tensioning means, and a trigger mechanism for preventing the movement of said sear by said second spring when tensioned.

7. In a gun having a movable bolt and a firing mechanism, a spring urging said firing mechanism to firing position, means cooperating with the firing mechanism and movable to one position to hold the ring mechanism in cocked position and movable to another position to release the same, means including a spring constructed and arranged to move said holding means to release said ring mechanism when operatively tensioned, means including a. trigger constructed and arranged to prevent movement of the holding means by the spring means in one position and to allow movement thereof in another, and means simultaneously movable with said bolt and independently of the releasing or cooking movement of the first-mentioned holding means to operatively tension said spring.

8. In a gun having a movable bolt, a firing mechanism, means movable to a rst position to hold the firing mechanism in cocked position and movable to a second position to release said ring mechanism, means to move said holding means to the rst position, and means to move said holding means to the second position, said last mentioned means comprising a spring operatively connected to said holding means and constructed and arranged to be tensioned by a portion of the gun mechanism simultaneously movable with said bolt.

9. In a gun having a movable bolt, a ring mechanism, means movable to a rst position to hold the ring mechanism in cocked position and movable to a secondposition to release said firing mechanism, a spring constructed and arranged to move said holding means to the rst position and a second spring constructed and arranged to move said holding means to the second position, said second spring being constructed and arranged to be tensioned by a portion of the gun mechanism simultaneously movable with said bolt.

10. In a gun, a tiring mechanism including a striker and a spring urging said striker to ring position when tensioned, means movable independently oi said striker for tensioning said spring, means cooperating with said striker and movable to one position to hold the striker in cocked position and movable to another position to release the same, means including a spring constructed and arranged to move said holding means to release saidv striker when operatively tensioned, means including a. trigger constructed and arranged to -prevent movement oi' the hold- ,mentioned spring.

ing means by the spring means in one position and to allow movement thereof in another, und .means simultaneously movable with the means for tensioning the mst mentioned spring, and independently of the releasing or cooking movement of the holding meansto tension said second DAVID M.