US 1593981 A
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Jul 27,1926. 1,593,981
- .1. c. R.- MOCRUDDEN FIHINGAND SAFETY MECHANISM FOR FIREARMS Filed March 25. 1926 Patented July 27, 19 26.
. UNETE STATES ear @FFEQE.
JOHN CHARLES REGINALD McoRUnnEN, F HuRs'rvI-LLE, NEAasYnNEY, NEW SOUTH WALES, AUSTRALiA.
FIRING AND SAFETY MECHANISM FOR FIREARMS.
Application filed. March 26, 1926, Serial No. 97,556, and in Great Britain September 22, 1924.
This invention relates to trigger-controlled firing-mechanism for firearms of the kind wherein a sear, normally engaging the firing-bent or notch of a bolt, cocking-piece,
being such as to permit of the trigger-arm being moved from beneath the sear-arm before the trigger comes into action to withdraw the sear-nose from engagement with 5 tumbler or equivalent coacting element of the firing-mechanism, is prevented from accidental disengagement therefrom by a locking-member which is carried by and movable asone with the trigger and is normally presented in position to revent movement of the sear, the pulling of the trigger having for effect to withdraw the locking-member from engagement with the sear immediately before the latter is itself withdrawn, as a said firing-bent or notch. For the purpose of actuating the sear, the upwardly-extend ing trigger-arm may have a forward projection adapted, when the trigger has been pulled so far as to unlock the sear, to engage a downwardly-projecting arm on the sear so as to withdraw the sear from engagement with said firing-bent or notch. The scar may also be provided with a forwardly-extending arm having freedom for limited downward den blow, when t result of continued actuation of the trigger, from engagement with said firing-bent or notch. The primary object of the present invention is to provide an improved construction, applicable in cases wherein the trigger and the sear are each constituted by a pivoted lever, with a view more effectually to obviate risk of accidental discharge of the firearm as a result of the sear being jarred off by the shock due to a fall, or to a sud he weapon is cooked; a further object being to ensure that, in an automatic quick-firing weapon, release of the finger-pressure upon the trigger (as when the operator is put out of action) will result in the sear becoming automatically relocked, so that-the firing of the weapon will cease.
According to the present invention the triggenaxis and sear-axis are so placed relatively to one another and to the point of mutual engagement between the locking member and the sear that lines joining said point with the respective axes are substantially at right angles to one another whilst the searnose, which engages in the firing bent or notch of the bolt or other coasting element of the firing-mechanism, is situated approxi mately in a prolongation of the iine joining the trigger-axis with said point of mutual engagement and out of the line joining the sear-axis with the same polnt.
The locking member may. .be constituted by an upwardly-extending. arm of the trigger-lever whilst the sear may have a rearwardly-extending arm adapted, so long as the trigger remains in normal position, to rest upon said trigger-arm and thus retain the sear-nose (constituted by the rear extremity of said sear-arm) in engagement with the firing-bent or notch; the mutual en gagement of the sear-arm and trigger-arm movement, this arm resting upon a cushionspring adapted to reinforce the action of the sear-spring and deaden or partially absorb any jar or'shoc'k tending to displace the sear from engagement with said firing-bent or notch. r
. Further, the trigger may be. provided with a sefety-lever whereby to prevent its accidental actuation, this safety-lever being itself moved to and held locked in the operativ-e or safety position and in'the inoperative position alternatively by means of a camlever mounted, in the pistol hand-grip or equivalent part of the stock, in such position as to be readily felt, more especially when in the safety position, by the trigger-hand when the latter is applied to the weapon, even in the dark. I
One form of theinvention is illustrated in the accompanying drawing, which shows, in partly sectionalside elevation, only such parts of the firing mechanism as are required for the purpose of explanation".
The trigger 11, pivoted at 12, and present- 7 ing the curved finger-piece 13 behind the trigger-guard l t, tends under stress of the trigger-spring 15- to occupy the normal or resting; position tshown in full outline) determined by the arm 16 contacting. with the stop 17. The sear 18', pivoted at 19 about an axis situated above v tri'ggetaxis 12, has a re'a'rwardlyand upwardly extending arm 20 the rear extremity or nose 20 of which, normally held raised by the sear-spring 21'as indicated, is'adapted then td engage in the fi-ring bent or notch of the bolt,- cocking-piece, tumbler, or equivalent coacting element ('not shown) of the firi ng-mecl ranism, s'oas to prevent the discharge of the weapon, The scar 18 has also a forward-1y and downwardly extending. arm
and forward of the,
22 which rests upon a coiled cushion-spring 23 held in a socket 2a, theupwardly-presented lip of which serves as a stop adapted to oppose a positive limit to the movement of the sear under the stress the cushion-spring 23 and sear-spring 21 will dead'en or partially absorb any jar or shock upon the sear-nose 20, such as is liable to arise from the reaction of a powerful recuperator-spring (not shown) I in automatic small-arms and like in the direction, approximately, of the searaxis l9g'and the notch 25 is made long enough, towards the sear-axis 19, to allow; of the extremity of the trigger-arm 26, when the trigger is pulled, passing clear of its engagement with the step 27 on the sear; the notch 25being also made deep enough, when the trigger-arnr 26 has been; thus moved clear of the sear-step at 27, to allow such depression of the sear-arm-o20 as is necessary to rele'asethe sear-nose-2O from the firing-bent or notch of the bolt or equivalent element of the firing-mechanism. The triggerarm 26 has formed upon it aforward projection 28 adapted, assoon as'the arm 26 has been moved clear-ofjthe searstep at 27, to encounter and move forwards (as indicated by the dotted outline) a down.- wardly-extending arm 29 on the sear'18,
' whereby, on the trigger being pulled'to its 20 is. depressed full extent, the sear-arm against the stressof the sear-spring 21 so as to release the searn0s e 20*:from the firing-bent or notch of the bolt (or equiva lent element) and thusbringabout the dis-- charge of the weapon. 1 a 1 g The substantially vertical rear surface of the sear-nose 20*, where the latter normally engages in the firing-bent-or notch just re ferred to, is situated above the level of the scan-axis 19 and out of the direct line of the. thrust, towards said axis, exerted by the bolt or equivalent element when the weapon is cooked, so that the sear 18 then has freedom for a slight rocking movement, about'lits axis 19, permitted by the cushionspring 23; such. movement, whilst sufiicient to absorb the eflect of arring or 1 sudden of its spring 21 t the end of the sear normally resting just clear of this stop, so that combined action of of v operative "position,
ing when the knobw42 i forced by the hand i p of the operator from the full-line shock, being nevertheless insufiicient to release the sear-nose 2O from'the firing-bent or notch of the bolt or equivalent element,
so that danger of accidental discharge of the Weapon due to such cause is elimlnated.
It will be observed that if, after a discharge, or during series of discharges in the case of an automatic or semi-automatic small-arm, the pressure on the finger-piece be released, the trigger and sear will at once return to their normal position,-so that'the "firing of the weapon will automatically cease. 1 a
- In conjunction with the above, the trigger 11 may be provided (as in frequent practice) with a safety-device for enabling it to be positively lockedagainst actuation until the weapon is tobe' actually discharged; In
the example illustrated, the lockingis effectedby Y the substantially horizontal arm 30 of a bell crank lever pivoted at 31, about atransverse axis within the up erpart of the hollow pistol-grip 32 of the re-arm, the arm 30 extending forwards through: an opening 33 in the front wall of the grip 32 so as,
by bearing against a projection 34 on. the I rear side of the finger-piece 13 of the trigger, to prevent the latter'from being pulled.
From the pivot 31, a second arm 35 of this bell-cranklever extends downwards within the hollow pistol-grip 32, the lower end of' this arm 35 being rearwardly directed and forked" as at 36 to carry a transverse pin 3'? which engages .a cam-slot 38 in a small camlever 39 pivoted at 40 to swing in or parallel to the plane of movement of the arm' 35. The arm 35 is inaccessible, but can at will be moved by means of the cam-lever 39 so as,
by shifting thebell-crank lever from the full-line to the dotted-line position, to with draw the arm 30 from the position wherein it prevents the pulling of the trigger. For
this purpose the end of the cam-lever 39 projects'outside the pistol-grip 32 through aslot 41 provided therein, the end of thecam-levei' being furnished with a knob -12 which, when the arm 30 is in the operative position shown in full outline, is presented-towards the rear Ofthepistol-grip so asto be readily felt by the trigger-hand of the operator, even in tllfldillk. The cam-lever slot 38 is of such form, and so placedrelatively tothe pin 37 and axis 31, as to necessitate the exertion' of a slightzelfort to move the safetylever 30, 35 from'the operativeto the inoperative vposition, the cam-lever 39 itself being' madepreferably from springy sheet-' metal so as, whilst adapted so to hold the pin 37 as to resist any tendency of the safetylever 30,35 to b'e'come'shaken or jarred out to be capable of yieldsafety-lever 30, 35 is in-the' inoperative p0- 7 shown) provided for the purpose and forming a widened mouth for the slot ll.
It will be obvious that, instead of an arm such as 26 on the trigger entering a notch such as in the sear, the sear 18 might have a depending arm entering a notch in the upper end of the trigger-arm 26, provided always that the mutual engagement of the trigger and sear is such that, so long as the trigger occupies its normal or resting position, the sear is prevented from becoming disengaged from the firing-bent or notch of the coacting element of the firing-mechanism, but is freed when the trigger is pulled so as to depres the sear-nose 20*.
I claim I 1. Trigger-controlled firing-mechanism for fire-arms of the kind referred to, comprising a trigger, a sear, mutually engaging members on the trigger and sear respectively whereby the trigger is adapted to prevent movement of the sear out of engaging position with the bent or notch until the trig ger is pulled, said trigger and sear being pivotally mounted on axes so placed relative to one another and to the point of mutual engagement between the sear and the trigger that lines joining said point with the respective axes are substantially at right angles to one another, a nose on said sear for engaging the firing bent or notch, said nose being situated approximately in a prolongation of the line joining the trigger axis with said point of mutual engagement but out of line joining the sear axis with said point, resilient means holding the nose of said sear in position for cooperation with the bent or notch, and coacting members on the trigger and sear respectively for moving said nose out of the bent or notch by a continuing pull on the trigger, the initial movement of which disengages said mutually engaging members, substantially as set forth.
2. Trigger-controlled firing-mechanism as claimed in claim 1, wherein said trigger is provided with an upwardly extending looking arm, and said sear is provided with a rearwardly extending arm, carrying said nose, adapted, when the trigger is in normal position, to rest upon said upwardly extending arm to thereby retain the nose of the sear in position to engage the firing bent or notch, the mutual engagement between said sear and trigger being such as to permit the trigger arm to be moved to release said sear arm before the trigger comes into action to withdraw the nose of the sear from its position of engagement with the firing bent or notch of the co-acting element of the firing mechanism, substantially astset forth.
3. The trigger-controlled firing-mechanism as claimed in claim 1, in which said sear is provided with a forwardly extending arm cooperating with a stop member for limiting rebound movement of said sear When the trigger is released after firing and a cushion spring engaging said forwardly extending arm, for absorbing rebound shock of said sear, substantially as and for the purpose set forth;
4. In trigger-controlled firing mechanism as claimed in claim 1, the combination therewith of a safety lever, adapted to be moved into position tocooperate with the trigger to prevent the latter from being pulled and a cam lever for moving and controlling the position of said lever, substantially as and for the purpose set forth.
JOHN CHARLES REGINALD McCRUDDEN.