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Publication numberUS2855716 A
Publication typeGrant
Publication dateOct 14, 1958
Filing dateApr 5, 1955
Priority dateApr 5, 1955
Publication numberUS 2855716 A, US 2855716A, US-A-2855716, US2855716 A, US2855716A
InventorsCampbell Clark S
Original AssigneeRemington Arms Co Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Fire control mechanism
US 2855716 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Oct. 14, 1958 c. s. CAMPBELL FIRE CONTROL MECHANISM I 2 Sheets-Sheet 1 Filed April 5, 1955 INVENTOR. CLARK 5. CAMP6LZ Oct. 14, 1958 c. s. CAMPBELL FIRE CONTROL MECHANISM 2 Sheets-Sheet 2 Filed April 5, 1955 INVENTOR.

CLARK 5. CAMPBfLL \kfw a) ATTORNQS FEE CONTROL MECHANISM Clark S. Campbell, Ilion, N. Y., assignor to Remington Arms Company, Inc., Bridgeport, Conn., a corporation of Delaware 1 Application April 5, 1955, Serial No. 499,397

3 Claims. (Cl. 42-69) This invention relates to fire control mechanism adapted to be utilized with either manually operated or autoloading firearms.

The fire control mechanism shown in Patent No. 2,675,638, issued April 20,,1954, to L. R. Crittendon has wide application to a variety of firearms manufactured by the Remington Arms Company, Inc., several of those firearms being shown in the patent. The fire control mechanism of the instant invention is designed to serve as a replacement for that of the cited patent in those instances where it is desired to improve the trigger pull characteristics with particular reference to a lighter pull, freedom from creep or blacklash, and faster lock time Such an improvement is the object of this invention.

The advantages of the so-called blocked sear type of fire control have long been realized and are readily applied to bolt action arms where the striker has only a straight line fore and aft movement. Insofar as I am aware, a blocked sear or other hammer controlling element which is urged to completely disengaged position by the force of the hammer spring has not previously been applied to firing mechanism employing the very common type of swinging hammer. A more specific object of my invention is to provide a blocked sear type of fire control for a swinging hammer firing mechanism.

The exact nature of my invention as well as other objects and advantages thereof will be readily apparent from consideration of the following specification referring to the attached drawings in which:

Fig. 1 is a longitudinal vertical sectional view through a fire control mechanism embodying my invention. The mechanism is shown in cocked position.

Fig. 2 is a similar view showing the same mechanism in fired position before relaxation of the grip on the trigger.

Fig. 3 corresponds to Fig. l but relates to another embodiment of my invention.

Fig. 4 is a view similar to Fig. 3, showing the same mechanism in fired position after the grip on the trigger has been relaxed.

Referring to the drawings, it may be seen that I have illustrated a fire control mechanism which would be directly interchangeable with that shown in Figs. 6 and 7 of the Crittendon patent above referred to, and which with obvious modifications could be applied to any other model shown in the patent.

Referring to the drawings by characters of reference, it may be seen that I have provided a trigger plate 1 which is essentially the same as that of the Crittendon patent and mounts a hammer 2 urged to swing upward and forward by a hammer spring 3 acting on a hammer spring plunger 4, communicating hammer spring force to the hammer. As in the Crittendon patent, the plunger 4 is arranged to impinge upon an arm 5 on the disconnector 6 and raise the tail 7 thereof whenever the hammer falls. A similar action of the disconnector is provided when rearward displacement of the breech Patented Oct. 14, 1958 ice 2 bolt carrier, also as shown in the patent, overrides the forwardly extending arm 8 of the disconnector.

The mechanism described thus far is substantially that of the Crittendon patent and the differences which characterize my invention are to be found in the hammer controlling means to be now described.

A rotating hammer block 9 comprises a V-shaped element mounted in the trigger plate 1 for swinging movement about a fixed pivot near the apex of the V and is provided with a hammer engaging arm 10 which, in the position shown in Fig. 1, engages the hammer on the surface 11 and retains it in cocked position. A locking arm 12 extends rearwardly for engagement with an abutment on the sear 13 and a spring 14 acts between trigger plate and hammer block, applying a force in addition to the component of hammer spring force, urging the hammer block to free the hammer. Obviously, when the sear 13 is disengaged from the hammer block, the latter will eifect an instant and clean release of the hammer for a minimum of lock time. The mechanical advantage which can be obtained by variations in the length of the locking arm 12 permits a decrease in the force applied to the sear and/or permits the use of a heavier hammer spring and lighter hammer for further decreasing lock time.

The sear 13 is likewise mounted for rotation on a cross pin 15 in the trigger plate and is urged to swing anti-clockwise as viewed in the drawing to a position for engagement with the hammer block by means of a force applied below the pivot by a spring 16. The rear end of the spring engages the connector 17 which is swingably mounted on the upper end of the trigger 13. The connector is provided with a forwardly extending arm 19 which engages a step 20 on the sear above the pivot pin 15. Thus, the spring 16 acts in the same Way as the spring of the Crittendon patent, urging the sear into engagement, urging the connector into engagement therewith, and urging the trigger finger piece 21 to its normal forward position. Thus, as the trigger is pulled rearwardly,-the connector will rotate the sear clockwise, disengaging it from the hammer block and releasing the hammer to fall. The end of the arm 12 will ride up the forward surface of the sear above the abutment thereon and prevent return of the sear until after the hammer has been recocked.

Another arm 22 on the connector extends forwardly along the back side of the trigger plate and overlies the rearwardly extending arm 7 on the disconnector. Thus, as the hammer falls and the plunger 4 engages the arm 5, the arm 7 is lifted, carrying with it the arm 22 on the connector and disengaging the arm 19 from the sear step 20. The same disconnecting action will result from rearward displacement of the breech bolt overriding and depressing the disconnector arm 8. The arm 8 may also, as described in the Crittendon patent, be utilized as an action bar lock and provided with a manual release lever extending through a slot in the trigger plate.

Regardless of the means by which the disconnector is operated, it frees the sear from the control of the trigger and will only permit the trigger to regain control when the breech block is fully locked and the trigger finger relaxed to permit the trigger to return to a normal forward position.

After firing, the hammer block will be turned clockwise to the limit permitted by engagement of the arm 10 with the trigger plate retaining pin 23, and the arm 12 will serve as a stop limiting anti-clockwise rotation of the sear 13 under urging of the spring 16. As the hammer is returned to cocked position, it will engage the arm 12 on the hammer block rotating the block anti-clockwise into position for retention by the scar, and return lease of the hammer block. The extent or tiiggei ihdve inent prior to release of the sear is depehdiit the starting position or the trigger which is conttolled by the engagement at the upper end the trigger with the tri ger plate retaining pincs. Tileposition may be controlled by selective assembly, 15y fitting of the trigger at assembly, or another adjustable trigger s'top' sc ew,

not s own, may be provided to control this function. The usual type of cross bolt safety 16 is also provided, and the degree of trigger movefrierit after release of the sear may be controlled as noted above, depending upon the engagement with the seetioned may of the safety 2'6 or upon another step serew, not shown, to prevent trigger stop or overtr'avel. I

Summarizing the operation of improved fire control, it will be seen that pulling of the trigger 2 1 urges the connector 17 forward and swings the sear 13 clockwise. This releases the hammer block 9 which swings clockwise to release the hammer 2. The fall of the hammer perinits the plunger 4 to engage the arm 5 on the disconnector, raising the arm 7 and disengaging the connector arm 19 from the sear step 20. The seat is thus released from control of the trigger, giving the sear freedom to swing anti-clockwise into position to engage the hammer block arm 12 when the hammer cocked again.

In the embodiment shown in Figs. 3 and 4, a similai combination of elements is provided and where parts are substantially similar they have been 'givensirnilar reference numerals. In this embodiment the hammer blocking member 27 is mounted behind hammer on the pivot 15 and engages with a surface 2 8 on the hammer 2. The sear 29 is mou ted on a pivot so and, when its front end is raised, releases the hammer block by disengaging from the corner 31 thereof. When the hammer block is so released, the hammer falls and the action of the spring 32 tends to return the hammer bloek to its former position. If the hammer block were per mitted to return in this way, it would interfere'with cock: ing of the hammer, so I have in this errilio'dir'nent pro vided a latch 33 which is held inoperative whenever the hammer is fully cocked. As the hammer moves; from cocked position, it disengages from the latch 33 and, since the hammer block i 's' theii iie'ce'ssarily out of the path or the ammer, it will e caught 'and retained by the latch until the hammer is again returned nearly to cocked position.

In this embodiment, the seat 29 isioper'ated a trig ger 34 mounted on thepivot pin 15 and provided with a connector 35 engaged by a spring '36 and urged thereby to a position extending across between the trigger 34 and an adjlist'able contact point 37 on the sear; This connector is, like those of the patent and the"erribt'xli merit of my invention alreadydes'iibed, provided with a forwardly extending arm 38 whichlie's along" the back side of the trigger plate and overlies the rearwardly extending arm? on the discoiinector. As in the case of the other embodiments, a cross-pin safety 26 may be provided and, i'rithis instance, can serve to positively block movement not only of the tri ger 3'4 but 'of the sear 29 as well.

To 'sur'nrnariie the oper'atio'nof this embodiment; and starting in the position shownin' F ig. 3, pulling of the trigger 34' operates through the connector 35 to disengage the sear 29 froin'the corner 31 of' the hammer block 27. Thereupon, the hammer camsthe hammer block out of the way and swings forward to fire a cartridge. As the hammer moves, the latch 33 is released to catch and retainthe' hamrherblockas shown in Fig. 4,

and as the hammer completes its fall the plunger 4 en gages the arm 5 and lifts the rear arm 7 of the diseonnector. This lifting of the" arm 7, in turn, as shown in Fig. 4, lifts the arm 38 oh the connector, disengaging the connector 35 from the contact 37 on the sear and releasing the sear from control of the trigger.

As the hammer is returned to cocked position, it swings by the hammer block 27 and then releases the latch 33, pe'rfi'iit tiiig spring 32 to swing the hammer blo'ckinto engagement withthe surface 28 on the ham mer. The scar 29, upon being freed from control of the trigger, swings down to engage the corner 31 and to hold the hammer block.

Assuming that triggerfiager pie'ss'uie has beeh ielaxed after firing and that the" breech block is closed and locked after cocking, permitting the arm 8 on the disconnector to raise, the connector 35 will swing into posi ion to control the sear as soon as the disconnector 7 letters thceiti'pletion'bf breech locking movement. The erases-sit satay 2% may then be slaved is the usual way to position a large diameter section in opposition both to ti ig' ge'r and "seat to positively prevent movement of either one,

With this arrang ment, quite light trigger pulls can be provided with safety; for all eritical components are in reasonably good static and dyhamic balance and, hence, reasonably ifn'rriufie' to aecidental shocks. The practical limit on trigger 151111 is that imposed by the possibility of accidental eagageiaefit 6f the trigger by brush, eta, or by a 'Iie'rvo iis hunter.

this a'ri'aiig'eifiefit I ran 'p'r'ovide for barely perceptible trigger movement prior to actual release and for substantially no excessmovement after release of the tfig'ger. It is pastime with this construction to provide a tfi g'er 'pull is assets the target shearer; ideal with the rug' eahess 'afid' eatery required or a practical liiihtingrifl'e. M N

3 Although I have shti'wh' only an) embodiments of my inve tion, it will be swims that other embodiments and modifications are possible. Accordingly, it should be noted that I consider the scope of my invention to be limited by the laiiiljs' appended hereto rather than by thedetails of the emis'odimefits illustrated.

1. In fire cohtrbl mechanism comprising a pivotally mounted haii i'rner, a ttirust p'ie'ce engaged with said hammer and a hammer 'sii'ri'ng" engaging the thrust-piece and urging said hammer' 'fi'om a cocked position to a fired p'osih'o'ii; the improvement eorriprising in combination a hammer blocking member ivoauy engageable with said hammer to block said hammer in cocked position; a scar releasably engageable with said member to retain said member in hamme'r'blocking position; said member being forced out of the path of said hammer to a released position by said spring-urged hammer on release of said sear, means to obstruct return of said member tb blocking" position until said hammer approaches fully cocked position, comprising a latch for engagement with said member in released position, said latch, having a release arm disposed in the path of movement of said h'ai'n'n'ier to cocking position, whereby engagement of said 'arm by said ha'rfiiner releases said member from said latch; a trigger; and connector means coupling said sear to said trigger for manual release, said connector means comprising a pivotal element moveable out of engagement with said sear a'fter sear release, whereby said sear is free to return 'to member retaining position.

2. In a fire control mechanism comprising a pivotally mounted hammer having an angularly disposed extension thereon which is provided with a locking surface, a thrust-piece engaged with said hammer and a hammer spring, engaging said thrust-piece and urging said harnmer from a cocked to a fired position, the improvement comprising in combination a trigger, a scar pivotal'ly moveable from a locking position to a released posit-ion,

' said connector from said sear when said sear reaches released position, hammer blocking means interposed between said sear and said hammer including a member pivotal from a first position wherein the member is retained in blocking engagement with said hammer locking surface by said sear in locking position, to a second position wherein said member frees said hammer and has a member portion retaining said sear in released position, and means for returning said member to first position comprising an element of said hammer blocking means disposed in the path of travel of said hammer for displacement by said hammer in movement to cocked position.

3. In a fire control mechanism for a firearm comprising a pivotally mounted hammer having anangularly disposed extension at its free end, a locking surface on said hammer extension, a thrust-piece engaged with said hammer and a hammer spring engaging said thrust-piece and urging said hammer from a cocked to a fired position; the improvement comprising in combination a pivotally mounted hammer blocking member having a hammer locking arm thereon, said locking arm being disposed in the path of movement of said hammer extension whereby movement of said hammer to cocked position will cause pivotal movement of said member to a blocking position, a hammer engaging arm on said member disposed to facially engage said hammer locking surface when said member is in blocking position, means for retaining said member in blocking position against the releasing force of the said spring-urged hammer comprising a sear pivotally moveable from a member locking position in engagement with said locking arm to a released position; a trigger; a connector pivotally mounted on said trigger for moving said sear to released position, and means for disengaging said connector from said sear when said sear reaches released position.

References Cited in the file of this patent UNITED STATES PATENTS 1,147,906 Swebilius et al. July 27, 1915 2,126,076 Wright et al. Aug. 9, 1938 2,249,231 Smith July 15, 1941 2,457,001 Smith Dec. 21, 1948 2,584,299 Sefried Feb. 5, 1952 2,675,638 Crittendon Apr. 20, 1954 2,775,837 Perry et al. Jan. 1,1957

FOREIGN PATENTS 6,672 Great Britain 1913

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US2457001 *Oct 4, 1945Dec 21, 1948Savage Arms CorpTrigger action for automatic firearms
US2584299 *Jul 15, 1948Feb 5, 1952Olin Ind IncFire-control mechanism for firearms
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Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3090148 *Oct 15, 1958May 21, 1963Smith Walter H BBolt action firearm with charger
US3314183 *Dec 2, 1964Apr 18, 1967Harrington & Richardson IncFirearm
US3965604 *Aug 22, 1974Jun 29, 1976Efim Leontievich KhaidurovFiring and trigger mechanism for self-loading match pistol
US3972142 *Nov 29, 1974Aug 3, 1976Takeji KawamuraShot gun
US4152856 *Apr 25, 1977May 8, 1979Ithaca Gun CompanyTrigger mechanism
US5274939 *Dec 31, 1991Jan 4, 1994Benelli Armi S.P.A.Firing mechanism for firearms
US6131324 *Nov 30, 1998Oct 17, 2000Jewell; Arnold W.Adjustable dual stage trigger assembly
US7562614 *May 17, 2006Jul 21, 2009Sa Ordinance, LlcClosed bolt system with trigger assembly for converting a fully automatic submachine gun into a semi-automatic carbine
EP0494439A1 *Jan 1, 1992Jul 15, 1992BENELLI ARMI S.p.A.Firing mechanism for firearms
U.S. Classification42/69.3, 89/144
International ClassificationF41A19/00, F41A19/45
Cooperative ClassificationF41A19/45
European ClassificationF41A19/45