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Publication numberUS3142926 A
Publication typeGrant
Publication dateAug 4, 1964
Filing dateJun 27, 1962
Priority dateJun 27, 1962
Publication numberUS 3142926 A, US 3142926A, US-A-3142926, US3142926 A, US3142926A
InventorsMorrow Edward L
Original AssigneeOlin Mathieson
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Trigger with adjustable screw and stud therein
US 3142926 A
Abstract  available in
Previous page
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Claims  available in
Description  (OCR text may contain errors)

TRIGGER WITH ADJUSTABLE SCREW AND STUD THEREIN Filed June 27, 1962 INVENTOR. [DJ/144R!) L. MORROW WWW United States Patent 3,142,926 TRIGGER WITH ADJUSTABLE SCREW AND STUD THEREIN Edward L. Morrow, Fairfield, Conn., assignor to Olin Mathieson Chemical Corporation, a corporation of Virginia Filed June 27, 1962, Ser. No. 205,612 Claims. (Cl. 4269) This application relates to the method and means for adjusting the trigger assembly in a firearm.

The invention more specifically relates to the provision of a novel adjustable releasing stud for the trigger in a firearm trigger assembly.

In a firearm trigger assembly having a plurality of pivotally mounted and relatively movable elements including a trigger, a sear and a hammer; a buildup of tolerances occurs which necessitates and ajustment between the trigger and the sear to render the structure operative.

The tolerance buildup occurs because it is impossible to bore the holes for the pivotal connections with exact accuracy. The pivot pins and other elements found in such structures are furthermore not perfectly dimensioned. Thus, the plus and minus tolerances accumulate so that some means must be devised to adjust the tolerances at final assembly. This problem becomes more acute in those trigger assemblies in which the pivoted sear is mounted on a pivotal sensing element, such as in the device disclosed in Brunelle Patent 2,922,241, since such a structure introduces additional pivotal connections.

It has been the practice in the art to completely assemble the trigger assembly, measure the tolerance between the trigger and the sear, and then disassemble the structure to adjust the tolerance. This is done by initially providing the trigger with a raised integral lug, or a stepped portion as in Patent 2,922,241, in the area where the trigger engages the sear. Upon disassembly the lug or step is filed down by hand to provide an acceptable operative tolerance between the trigger and the sear.

It is therefore an object of this invention to provide novel adjusting means for a trigger assembly which can be readily adjusted at final assembly; thereby eliminating the necessity of assembly, measurement, adjustment, and then final assembly which is a time consuming and tedious operation.

It is a further object of this invention to provide a trigger assembly with adjusting means which can be adjusted at final assembly and then locked in place to prevent tampering with the adjustment.

These and other objects and advantages of this invention will become more readily apparent from the following detailed description and the drawings in which:

FIG. 1 is a side view partly in section showing the trigger assembly of this invention.

FIG. 2 is a detailed side view of the trigger and adjusting means.

Referring now to FIG. 1 of the drawing, there is shown a trigger housing generally indicated 1. A trigger 2 is pivotally mounted in the housing by means of a pivot pin 3. The trigger 2 is provided with a stud 4 which engages a projection 5 on a scar 6. The sear 6 is pivotally mounted by means of pivot pin 7 on a sensing lever 8. Sensing lever 8 is in turn pivotally mounted in the trigger housing 1 by means of a pivot pin 9. Sear 6 has a hook portion 10 which is engageable with a hook portion 11 of hammer 12. Hammer 12 is pivotally mounted in trigger housing 1 by means of a pivot pin 13.

In operation, trigger 2 is squeezed manually and I0- tates about its pivot 3. Stud 4 engages projection 5 on sear 6 to rotate the sear in a counterclockwise direction away from hammer 12. As the sear is rotated, hook portion 10 on the sear becomes disengaged from the hook portion 11 on the hammer 12 and the hammer is released. Spring means (not shown) drive the hammer 12 toward impacting engagement with a cartridge positioned in the firearm chamber (not shown).

It is apparent that the engagement between stud 4 on the trigger and projection 5 on the sear requires careful adjustment if the device is to be operative. If the tolerance between the stud 4 and projection 5 is too great, the gun will not fire. If the tolerance is too close, the trigger will be too sensitive.

To provide for the correct tolerance adjustment between stud 4 and the projection 5, the novel arrangement shown in detail in FIG. 2 is provided. Trigger 2 is bored to provide an opening 14 adapted to accommodate a narrow shank portion 15 which is integral with stud 4. The opening 14 is tapped to provide screw threads 16 approximately halfway into opening 14. A special screw 17 having a head 18 and a tapered neck 19 is threaded into opening 14. Stud 4 is pressed into opening 14 from the other end. The elements which comprise the trigger assembly are assembled in the manner indicated above. The assembly is then adjusted by pulling the trigger and turning screw 17 inwardly toward stud 4 until hammer release occurs. Screw 17 is then advanced an additional /8 turn and Locktite or other equivalent locking composition is applied to the screw. Locktite is a single component polyester resin sold by the American Sealants Company of Hartford, Connecticut. Head 18 is then broken off at the tapered neck portion 19.

It is apparent that this invention provides a novel and convenient structure for adjusting the trigger in a trigger assembly, which allows the adjustment to be accurately made after final assembly of the structure. The device disclosed herein, while being relatively simple, eliminates the necessity of assembling the structure, taking measurements, disassembling the structure, filing down a projection on the trigger, and then making a final assembly.

This invention has been described in detail with reference to the specific embodiment shown in the drawings; however, it is contemplated that modifications in structure and design can be made which will be within the scope of the appended claims.

I claim:

1. In a trigger assembly including a pivotally mounted sear engageable with a pivotally mounted hammer, a trigger having an opening therein, a stud pressed into one end of said opening, said stud having an enlarged head portion engageable with said sear, screw means threaded in the other end of said opening engageable with said stud to move said enlarged head portion to- Ward said sear as the screw means is rotated.

2. An adjustable trigger for firearms comprising in combination a trigger having an opening therein extending from a top surface through a bottom surface of the trigger, a stud having an enlarged head portion extending above the top surface of the trigger and a shank portion pressed into said opening, and screw means having a body portion threaded into said opening engageable with said stud and having a head portion.

3. The device of claim 2 in which the body portion and the head portion of said screw means are joined by a portion of reduced diameter so that the head portion can be easily removed after final adjustment.

4. In a trigger assembly including a pivotally mounted sear engageable with a pivotally mounted hammer, a pivotally mounted trigger having an opening extending from the top surface thereof through the bottom surface thereof, a stud including an enlarged head portion extending above said top surface and a reduced shank portion pressed into one end of said opening, screw means threaded into the other end of said opening and having a head extending below said bottom surface, said screw References Cited in the file of this patent UNITED STATES PATENTS Laudensack Feb. 9, 1937 Barnett June 28, 1949 Hoard Apr. 24, 1951 Cutler July 3, 1951 Brunelle Jan. 26, 1960

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2069887 *Jul 31, 1935Feb 9, 1937Winchester Repeating Arms CoSear-mechanism for firearms
US2474456 *Mar 4, 1947Jun 28, 1949J H Barnett Son And Company LtCocking mechanism for bolt action rifles
US2549904 *May 28, 1948Apr 24, 1951Hoard Roy CTrigger-adjusting means for firearms
US2559010 *Sep 16, 1949Jul 3, 1951Cutler Richard ETrigger attachment for firearms
US2922241 *Aug 4, 1958Jan 26, 1960Olin MathiesonTrigger mechanism with a breech bolt sensing element
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US3206884 *Apr 10, 1964Sep 21, 1965Purvis Vinson CAdjustable trigger shoe
US4910903 *Feb 27, 1989Mar 27, 1990Steyr-Daimler-Puch AgTrigger mechanism, particularly for sports pistols
US5018292 *Jan 2, 1990May 28, 1991West Dennis ELinkage assembly for trigger/sear assemblies
US6367465 *Aug 29, 2000Apr 9, 2002Alfred N. Buccieri, Jr.Trigger extension for paint ball marker gun
U.S. Classification42/69.1
International ClassificationF41A19/10, F41A19/00
Cooperative ClassificationF41A19/10
European ClassificationF41A19/10