US3271864A

US3271864A - Azimuth adjustment device with lock for firearm sights

Info

Publication number: US3271864A
Application number: US352696A
Authority: US
Inventors: John G Rocha
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-03-17
Filing date: 1964-03-17
Publication date: 1966-09-13
Anticipated expiration: 1983-09-13

Description

V SEARCH mm Sept. 13, 1966 J. G. ROCHA 3,271,864

AZIMUTH ADJUSTMENT DEVICE WITH LOOK FOR FIREARM SIGHTS Filed March 17, 1964 2 Sheets-Sheet 1 INVENTOR ATTORNEYS Sept. 13, 1966 oc 3,271,864

AZIMUTH ADJUSTMENT DEVICE WITH LOCK FOR FIREARM SIGHTS Filed March 17, 1964 2 Sheets-Sheet 2 INVENTOR John llRuchu ATTORNEYS United States Patent 3 271,864 AZIMUTH ADJUSTlVlENT DEVICE WITH LOCK FOR FIREARM SIGHTS John G. Rocha, Westfield, Mass., assignor to the United States of America as represented by the Secretary of the Naw Filed Mar. 17, 1964, Ser. No. 352,696 3 Claims. (Cl. 33-56) The invention described herein may be manufactured and used by or for the Government for governmental purposes without the payment to me of any royalty thereon.

This invention relates to gun sights and pertains more particularly to gun sights which are adjustable as to range and azimuth drift.

Certain shoulder arms, such as the M79 Grenade Launcher, are designed for high trajectory fire whereby the sight line for distant ranges must be elevated at a considerable angle relative to the bore axis of the gun. Because of this, the sights for such guns must be designed so that the gun structure will not interfere with the angular adjustment of the sights between the minimum and maximum ranges; whereby, the sight has to be offset respective to its point of mounting on the gun to be free of interference with the gun barrel. This means that where severe recoil shocks are created high torque forces are produced in the sight at the mounting axis so that it is impossible to maintain an azimuth adjustment with conventional types of adjustment devices.

It is, therefore, the principal object of this invention to provide such sights with an azimuth adjustment device in the axial mount thereof and means for locking the sight in its adjusted azimuth position.

The specific nature of the invention as well as other objects and advantages thereof will clearly appear from a description of a preferred embodiment as shown in the accompanying drawings in which:

FIG. 1 is an elevational view of a high trajectory sight mounted on a firearm barrel;

FIG. 2 is a view taken along line 2-2 of FIG. 1;

FIG. 3 is a view taken along line 3-3 of FIG. 2;

FIG. 4 is a view taken along line 44 of FIG. 2;

FIG. 5 is a view taken along line 55 of FIG. 2;

FIG. 6 is a fragmentary view similar to FIG. 2 but showing the locking member actuated to secure the azimuth adjustment device in the selected position; and

FIG. 7 is a perspective exploded view of the sight mount and the azimuth adjustment device therein.

Shown in the figures is a gun barrel 12 with a pad 14 integrally formed thereon for mounting a sight 16. Sight 16 includes a base plate 18 which is fastened to pad 14 and a sector member 20 which is mounted onto the base plate, as hereinafter described, so as to be swung by an azimuth adjustment device 22 around the vertical axis thereof. An optical sight tube 24 is mounted on sector member 20 for calibrated range adjustment.

Formed on top of base plate 18 is a boss 26 which is recessed at the top, as noted at 28, to form a rib 30 and a groove 32 bot-h of which are of U-configuration in lateral cross-section. A bore 34 extends vertically through base plate 18 and boss 26 from recess 28 and such bore is counterbored at 36 from the bottom end to form a shoulder 38. Recess 28 receives the bottom end of a mount 40 which is fixed at one side, as by welding, to seetor member 20 and which has a flange 42 formed around the base :so as to be received by groove 32 to hold the mount against vertical displacement. Mount 40 is substantially of U-configuration in lateral cross-section. However, the sides of mount 40 and flange 42 taper inwardly toward-s the side to which sector member 20 is fixed to provide clearance for limited rotational displace- 3,271,864 Patented Sept. 13, 1966 ment of the mount in recess 28 around the extended axis of bore 34.

A bottomed hole 48 having the same diameter as bore 34 extends upwardly into mount 40 from the bottom end thereof in axial alignment with such bore. An aperture 50 extends concentrically from hole 48 through the top of mount 40. Bore 34 and hole 48 receive a pintle 52 of similar diameter which acts as a bearing for the rotational displacement of mount 40. A rib 54 around the bottom of pintle 52 is received by counterbore 36 to limit vertical displacement of the pintle. Rotational displacement of pintle 52 is prevented by a pin 55 which extends transversely through base plate 18 and a vertical slot 56 that extends upwardly into pintle 52 from the bottom end thereof.

Vertical displacement of pintle 52 is converted to rotational displacement of mount 40 through the cooperation of a pair of cam followers 58 installed in the mount with a pair of cam slots 60 formed in the pintle. Vertical displacement of pintle 52 is effected by a shaft 62 which is threaded at one end, as noted at 64, to engage with a mating threaded bore 66 in the pintle. The opposite end of shaft 62 extends upwardly through aperture 50 and mounted on such extended end is a knob 68 which provides means for manually rotating the shaft.

Fixedly mounted on shaft 62 within hole 48 and above threaded portion 64 is a sprocket wheel 70 which is provided with a plurality of substantially semicircular recesses 72 formed between teeth 74. The overall diameter of sprocket wheel 70 is similar to that of hole 48. Contact of the bottom of knob 68 with the outside of top 75 of mount 40 and the contact of sprocket wheel 70 with the inside of the top holds shaft 62 against vertical displacement.

Extending downwardly into mount 40 from the top thereof is a keyhole slot 76 which slidingly receives a plunger 78 having a key portion 80 to prevent rotation thereof. Plunger 78 is biased upwardly in keyhole slot 76 by a spring 82. An orifice 84 provides communication between keyhole slot 76 and hole 48 in registry with sprocket wheel 70 and slidingly received by such orifice is a metallic ball 86 having the same radius as recesses 72. A substantially semicylindrical pocket 88 is transversely formed in plunger 78 so as to be in registry with orifice 84 when the top of the plunger is flush with top 75 of mount 40. Orifice 84 has a diameter similar to that of ball 86 and a length equal to the radius thereof and the radii of recesses 72 and pocket 88 are the same as that of the ball so that, when plunger 78 is in an unlocked position with pocket 88 in registry with the orifice, shaft 62 may be freely turned as teeth 74 cam ball 86 free thereof into the pocket and so that, when the plunger is displaced upwardly to a locked position with the pocket moved out of registry with the orifice, the ball is forced into the one of the recesses which is in registry with the orifice to block the shaft against rotation.

Plunger 78 is actuatable between the locked and unlocked positions by a ring-type locking member 90 which is rotatingly mounted on a reduced diameter bearing section 92 of knob 68 in contact with top 75 of mount 40 and so that the underside of the locking member has contact with the top of plunger 78 to hold the plunger in the unlocked position. Provided in the underside of locking member 90 is a notch 94 which, when in registry with plunger 78, permits the plunger to be displaced upwardly by spring 82 to the locked position.

Operation When sight 16 is to be adjusted to compensate for ballistic or windage drift, locking member 90 is turned to where notch 94 is disposed out of registry with plunger 78 so that the plunger is displaced downwardly to the unlocked position. With plunger 78 in the unlocked position, pocket 88 is in registry with orifice 84 so that ball 86 may be displaced thereinto out of interference with sprocket wheel 70 when knob 68 is rotated. Sect-or member 20 is swung around pintle 52 to the corrected position by turning knob 68 which causes rotation of shaft 62 and, therefore, vertical displacement of pintle 52 through the cooperation of threaded portion 64 with threaded bore 66. Vertical displacement of pintle 52 is converted to rotational displacement of mount 40 and, therefore, sector member 20 through the cooperation of ca-m slots 60 in the pintle with cam followers 58 in the mount. When the correct adjustment is made, sector member 20 is locked in position by turning locking member 90 to where notch 94 is in registry with plunger 78 so that the plunger is displaceable by spring 82 to the locked position. With plunger 78 located in the locked position, half of ball 86 is located in one of the recesses 72 while the other half is located in orifice 84, thereby blocking rotation of sprocket Wheel 70 to hold sector member 20 against displacement. If one of the recesses 72 is not in complete alignment with orifice 84, any slight displacement of shaft 62 will bring one into alignment without affecting the adjusted position of sight tube 24 because of the high ratio of turn relationship between the shaft and mount 40.

Although a particular embodiment of the invention has been described in detail herein, it is evident that many variations may be devised within the spirit and scope thereof and the following claims are intended to include such variations.

I claim:

1. A firearm sight having a base plate, a mount mounted on said base plate for rotational displacement respective thereto around a vertical axis, a sector member fixed to one side of said mount, a sight tube mounted on said sector member for calibratedTa fi geadjustment, an azimuth adjustment device having a pintle received by a mating hole in said mount and a bore in said base plate so as to act as a bearing for the rotational displacement of said mount and means for adjustably rotating said mount around said pintle, and means for releasably locking said mount at its adjusted position including a transverse pin through said base plate slidingly received by a vertical slot in said pintle to prevent rotation thereof respective to said base plate, means for displacing said pintle vertically, a pair of cam slots formed in said pintle, and a pair of cam followers on said mount having sliding engagement with said cam slots for converting vertical displacement of said pintle to rotational displacement of said mount.

2. The sight as defined in claim 1 wherein said means for displacing said pintle vertically include a shaft coaxially related to said pintle, means for threadingly engaging said shaft to said pintle, means for holding said shaft against axial displacement, and a knob mounted on said shaft to provide for rotational displacement thereof.

3. The sight as defined in claim 2 wherein said means for releasably locking said mount includes a sprocket wheel fixed to said shaft within said hole, a plurality of semicircular recesses formed between teeth around said sprocket wheel, a keyhole slot formed in said mount from the top thereof parallel to said hole, an orifice providing communication between said slot and said hole in registry with said sprocket wheel, a plunger slidingly disposed in said slot, a semicylind'rical pocket transversely formed in said plunger for registry with said orifice when a top end of said plunger is flush with a top of said mount, a ball slidingly received by said orifice, said orifice having a diameter equal to that of said ball and a length equal to the radius thereof and said pocket and said recesses having radii equal to the radius of said ball, a spring for biasing said plunger upwardly in said slot, a locking member rotatingly mounted on said knob for contact with the top of said mount and the top end of said plunger to hold the top end thereof flush with the top of said mount, and a pocket formed in the underside of said locking member for registry with said plunger to permit upper displacement thereof by said spring to move said pocket out of registry with said orifice when said pocket and said plunger are in registry.

References Cited by the Examiner UNITED STATES PATENTS 723,476 3/1903 De Mesquita 33-48 2,015,627 9/1935 Hug 33-69 LEONARD FORMAN, Primary Examiner.

S. S. MATTHEWS, Assistant Examiner.

Claims

1. A FIREARM SIGHT HAVING A BASE PLATE, A MOUNT MOUNTED ON SAID BASE PLATE FOR ROTATIONAL DISPLACEMENT RESPECTIVE THERETO AROUND A VERTICAL AXIS, A SECTOR MEMBER FIXED TO ONE SIDE OF SAID MOUNT, A SIGHT TUBE MOUNTED ON SAID SECTOR MEMBER FOR CALIBRATED RANGE ADJUSTMENT, AND AZIMUTH ADJUSTMENT DEVICE HAVING A PINTLE RECEIVED BY A MATING HOLE IN SAID MOUNT AND A BORE IN SAID BASE PLATE SO AS TO ACT AS A BEARING FOR THE ROTATIONAL DISPLACEMENT OF SAID MOUNT AND MEANS FOR ADJUSTABLY ROTATING SAID MOUNT AROUND SAID PINTLE, AND MEANS FOR RELEASABLY LOCKING SAID MOUNT AT ITS ADJUSTED POSITION INCLUDING A TRANSVERSE PIN THROUGH SAID BASE PLATE SLIDINGLY RECEIVED BY A VERTICAL SLOT IN SAID PINTLE TO PREVENT ROTATION THEREOF RESPECTIVE TO SAID BASE PLATE, MEANS FOR DISPLACING SAID PINTLE VERTICALLY, A PAIR OF CAM SLOTS FORMED IN SAID PINTLE, AND A PAIR OF CAM FOLLOWERS ON SAID MOUNT HAVING SLIDING ENGAGEMENT WITH SAID CAM SLOTS FOR CONVERTING VERTICAL DISPLACEMENT OF SAID PINTLE TO ROTATIONAL DISPLACEMENT OF SAID MOUNT.