US3599337A

US3599337A - Sight for firearm using high trajectory ammunition

Info

Publication number: US3599337A
Application number: US874736A
Authority: US
Inventors: Robert E Snodgrass
Original assignee: US Department of Army
Current assignee: US Department of Army
Priority date: 1969-11-07
Filing date: 1969-11-07
Publication date: 1971-08-17
Anticipated expiration: 1988-08-17
Also published as: CA924093A

Abstract

A gunsight includes a metering bar with a rack formed on opposite sides for selective engagement by a pinion gear in which the sight aperture is centered. The pinion gear is mounted in a slide which permits lateral displacement of the pinion gear relative to the bar between a position wherein it is engaged to a selected one of the racks to permit fine adjustment of the sight, and a disengaged position wherein it is disengaged from the selected rack and thereby free to be slid along the bar for rapid sight adjustment. The two racks permit adaptation of the sight for right and left-hand shooters by reversing the slide on the bar without other structural changes.

Description

ite States 1,158,926 11/1915 Just .1

Primary Examiner-beonard Forman Assisnin! ExaminerPaul G. Foldes Attorneys-Harry Mr Saragovitz, Edward J. Kelly, Herbert Her] and Albert E. Arnold, Jr.

ABSTRACT: A gunsight includes a metering bar with a rack formed on opposite sides for selective engagement by a pinion gear in which the sight aperture is centered. The pinion gear is mounted in a slide which permits lateral displacement of the pinion gear relative to the bar between a position wherein it is engaged to a selected one of the racks to permit fine adjustment of the sight, and a disengaged position wherein it is dis engaged from the selected rack and thereby free to he slid along the bar for rapid sight adjustment. The two racks permit adaptation of the sight for right and left-hand shooters by reversing the slide on the bar without other structural changes.

SIGHT FOR FIREARM USING HIGH TRAJECTORY AMMUNITION Background of the Invention This invention pertains to sights for firearms and more particularly to sights for those firearms which fire high trajectory ammunition.

With the growing firearm use of high trajectory ammunition many problems have arisen as to the sights. One of these problems has to do with the length of the elevational displacement required of the sight aperture for the full range of the ammunition. This in turn creates the problem of providing for these sights means for quickly adjusting them along the full lengths of their elevational displacement and yet having fine vernier adjustment.

Also, because of their nature, these sights are, of necessity, mounted on one side of the weapon. This raises problems because military sights of this type have to be mountable to different sides of the weapons for both rightand left-handed shooters, requiring major structural changes in the sight for the changeover.

SUMMARY OF THE INVENTION The present invention solves these problems by providing a sight in which the aperture is carried by a slide also provided with a pinion gear which has engagement with rack means on a metering bar to provide for fine vernier adjustment of the slide therealong. The slide is permitted limited lateral displacement by manual pressure whereby the pinion gear is disengageable from the cooperating rack means to permit quick sliding elevational adjustment of the slide along the metering bar. To simplify the sight structure and operation, the aperture is axially located relative to the pinion gear.

A rack is provided along both sides of the metering bar which permits the slide to be reversed, moving the pinion gear and the aperture from one side of the metering bar to the other, whereby the sight can be used on either side of the supporting firearm without any major structural change.

Moreover, the high trajectory ammunition for which this sight is especially desirable produces a normal ballistic drift during its flight. The standard sight systems are provided with linear means for automatically compensating for this drift at the different elevational settings. This ballistic drift, however, is found to follow a curve rather than a linear pattern so that the drift cannot be accurately compensated for by the linear means. In the present sight, the metering bar is curved to conform to the ballistic pattern and thereby more accurately compensate for the ballistic drift along its elevational settings.

Further advantages of the invention will be apparent from the specification and accompanying drawings which are for the purpose of illustration only.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of the sight of this invention;

FIG. 2 is an enlarged cross-sectional view taken along line 2-2 of FIG. 1;

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG.

FIG. 4 is a cross-sectional view similar to FIG. 3 but of an alternate embodiment of the invention;

FIG. 5 is a fragmentary view of the alternate embodiment showing the slide displaced laterally to disengage the pinion gear of the slide from the selected rack on the metering bar;

FIG. 6 is a cross-sectional view taken along line 6-6 of FIG. 4; and

FIG. 7 is a cross-sectional view taken along line 7-7 of FIG. 4.

DESCRIPTION OF A PREFERRED EMBODIMENT Shown in FIGS. 1--3 is a gunsight 12 comprising a base 14 which supports a metering bar 16 extending upwardly therefrom, and a slide 18 mounted on the bar, as hereinafter described, for elevational adjustment therealong. Slide 18 includes a carriage 20 which is substantially of U-configuration in cross section, as shown in FIG. 2, to form a slot 22 for receiving bar 16 with free ends 23 of the carriage arranged to extend beyond the bar when the slide is mounted thereon. Formed on the left side of bar 16 is a rack 24 and another rack 26 is formed on the right side thereof. Rotatingly mounted between anns 28 of carriage 20 adjacent free ends 23 thereof is a pinion gear 30 which has meshing engagement with

rack

24 or 26, depending on whether slide 18 is mounted on bar 16 so that the pinion gear is on the left or right side thereof. Pinion gear 30 and arms 28 are so dimensionally related that a sufficient portion at the toothed circumference of the pinion gear is exposed for ready manual rotation thereof, as shown in FIG. I. Pinion gear 30 is provided with integral axle stubs 32 which extend outwardly from opposite sides thereof so as to be rotatingly received by cooperating holes 34 in arms 28. A pair of pins 38 extend through arms 28, between bar 16 and pinion gear 30, to secure the arms against relative spaced displacement. Sight aperture 40 extends coaxially through pinion gear 30 and is formed by two converging conical sections coaxial therewith, as shown in FIG. 2.

Mounted longitudinally through slot 22 adjacent base portion 42 of carriage 20 are two pins 44 the ends of which are received by vertically spaced holes 46 in arms 28. Holes 46 are elongated laterally, as shown in FIG. 1, to permit relative lateral displacement of pins 44 and carriage 20. Each of the pins 44 rotatingly mounts within slot 22 a gear 48 which is engageable with

rack

24 or 26 depending on which way slide 18 is mounted on bar 16. Each pin 44 with gear 48 mounted thereon is biased towards bar 16 by a spring 50 which acts through a follower 52 of U-configuration which straddles the related gear 48 to contact the associated pin 44 on opposite sides thereof as shown in FIG. 2. Thus, gears 48, in coopera tion with the associated springs 50, act to resiliently hold pinion gear 30 in engagement with the selected

rack

24 or 26 and stabilize carriage 20 on bar 16. Holes 46 are elongated sufficiently to permit lateral displacement of slide 18 relative to bar 16 to where pinion gear 30 is disengaged from the selected

rack

24 or 26 and the slide can therefore be freely moved along the bar for quick adjustment of elevation.

Sight 12 is readily adapted, without any structural modifications, for either a rightor a left-hand shooter by reversing slide 18 on bar 16 so that pinion gear 30 is located on the left side of the bar for a right-handed shooter or on the right side for a left-hander shooter. When slide 18 is reversed, pinion gear 30 engages the

opposite rack

24 or 26. The front sight on the supporting firearm, of course, must be changed laterally to compensate for the changed location of aperture 40.

Calibrations 54 in selected increments of range distances are provided along the length of bar 16 and these calibrations are observable through a window 56, provided in each of the arms, in whichever position slide 18 is mounted on bar 16. Calibrations 54 and windows 56 are so related that when a selected range setting is centered in one of the windows 56 aperture 40 is adjusted to the indexed setting. Bar 16 may be curved, as shown in FIG. 1, according to the ballistic curve of the ammunition for the gun to which sight 12 is mounted, to automatically compensate for the deviation as slide 18 is elevationally adjusted to the estimated range distance.

To adjust sight 12 to a target. the hand of the shooter presses base 42 of carriage 20 towards bar 16 to disengage pinion gear 30 from the selected

rack

24 or 26. Thus, slide 18 is free to be quickly slid along bar 16 to the estimated range setting. Thereafter, vernier adjustment of slide 18 is achieved by rotating pinion gear 30 to move slide 18 in fine adjustments along bar 16. Slide 18 is prevented from being run off the top of bar 16 by a stop 58 threadingly mounted through bar 16 adjacent the top end thereof. The adjustment by pinion gear 30 is facilitated as slide 18 is moved along bar 16 in the direction of rotation of the pinion gear.

Shown in FIGS. 4-7 is an alternate embodiment of the invention wherein a slide 60 corresponding to slide 18 in the previously described embodiment comprises a carriage 62 having a base portion 64 with a pair of arms 66 extending from opposite sides thereof. Free ends 68 of arms 66 extend beyond bar 16 and mounted between the arms adjacent the free ends I is an aperture member 70 of cylindrical configuration. Provided axially through aperture member 70 is a sight aperture 76 formed by two converging conical sections coaxial therewith, as shown in FIG. 7. The outside surface of aperture member 70 provides a bearing surface 72 for a wheel 74 mounted for rotation thereon. Formed on wheel 74 coaxially therewith is a pinion gear 78 which has meshing engagement with either

rack

24 or 26, depending on which position slide 18 is mounted on bar 16. The diameter of pinion gear 78 is less than that of pinion gear 30 of the previously described embodiment so that much finer adjustment can be made when wheel 74 is rotated and, because of the reduced size of pinion gear 78, wheel 74 is provided as a more convenient means for adjusting sight 12. The outside of wheel 74 is knurled to facilitate the manual rotation thereof.

Slide 60 is laterally displaceable relative to bar 16 between an engaging position wherein pinion gear 78 is engaged with

rack

24 or 26 and a disengaged position wherein the pinion gear is disengaged therefrom. Slide 60 is resiliently pressed to the engaged position by gears 80 which correspond to gears 48 of the previously described embodiment and are mounted similar thereto on pins 82 which are laterally displaceable in elongated slots 84. Gears 80 are pressed resiliently away from base portion 64 towards bar 16 by an arched leaf spring 86 the outside surface of which, at the center of the arch, contacts thebase portion. The ends of spring 86 contact both pins 82, as noted in FIGS. 4 and 6, so that pressure is applied through the arch in the spring to base portion 64 to press it outwardly away from bar 16 and therefore press pinion gear 78 into contact therewith. The operation of sight I2 with slide 60 mounted thereon is the same as that described for the previously described embodiment.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

Iclaim:

l. A gunsight comprising a metering bar calibrated in increments of target distance, a pair of racks respectively formed on opposite sides of said metering bar, a pinion gear, means for mounting said pinion gear relative to said metering bar for displacement respective thereto between a position wherein said pinion gear has engagement with a selected one of said racks and a position wherein said pinion gear is located out of engagement with the selected one of said racks, and for ready manual rotation, and a sight aperture coaxially formed through said pinion gear and comprising two converging conical sections coaxial therewith.

2. The invention as defined in claim 1 wherein said means comprises an aperture member of cylindrical configuration and a bearing surface formed on the outside of said aperture member to rotatingly mount said pinion gear thereon, and wherein said sight aperture is formed coaxially through said aperture member. 7

3. The invention as defined in claim 1 wherein said means comprises a carriage mounted to said metering bar for sliding displacement therealong and relative displacement normal thereto, axle studs formed on opposite sides of said pinion gear, and cooperating holes in said carriage for rotatingly receiving said axle studs.

4. The invention as defined in claim 3 and including biasing means operationally disposed between said carriage and said metering bar to resiliently press said pinion gear normally into engagement with the selected one of said racks and to permit the displacement of said carriage for moving said pinion gear out of engagement with the selected one of said racks against the bias of said biasing means. I

5. The invention as defined in claim 4 wherein said biasing means comprises a pair of gears each rotatingly mounted to said carriage for engagement with the one of said racks opposite the one thereof engaged by said pinion gear and for limited normal displacement relative to said metering bar, and spring means operationally disposed between said gears and said carriage for simultaneously biasing said gears and said pinion gear into engagement with said racks.

6. The invention as defined in claim 4 and including a wheel coaxial to said pinion gear to provide means facilitating manual rotation thereof when the diameter thereof is reduced for vernier purposes to where it is inconvenient for manual rotation.

7. The invention as defined in claim 6 wherein said metering bar is arcuately formed to conform to the ballistic curve of the ammunition to which said sight is adapted to automatically adjust said sight aperture to the deviations of the ballistic curve at the increments of target distances calibrated on said metering rod.

Claims

1. A gunsight comprising a metering bar calibrated in increments of target distance, a pair of racks respectively formed on opposite sides of said metering bar, a pinion gear, means for mounting said pinion gear relative to said metering bar for displacement respective thereto between a position wherein said pinion gear has engagement with a selected one of said racks anD a position wherein said pinion gear is located out of engagement with the selected one of said racks, and for ready manual rotation, and a sight aperture coaxially formed through said pinion gear and comprising two converging conical sections coaxial therewith.

2. The invention as defined in claim 1 wherein said means comprises an aperture member of cylindrical configuration and a bearing surface formed on the outside of said aperture member to rotatingly mount said pinion gear thereon, and wherein said sight aperture is formed coaxially through said aperture member.

4. The invention as defined in claim 3 and including biasing means operationally disposed between said carriage and said metering bar to resiliently press said pinion gear normally into engagement with the selected one of said racks and to permit the displacement of said carriage for moving said pinion gear out of engagement with the selected one of said racks against the bias of said biasing means.