US2792632A - Cam actuated sight - Google Patents

Description

33-258 OR n zwaz SR y 1957 H. E. PINKERTON, JR 2,792,632

CAM ACTUATEID SIGHT Filed April 12, 1954 5 Sheets-Sheet 1 IN V EN TOR.

ATTO-QNEYS H. E. PINKERTON, JR

May 21, 1957 CAM ACTUATED SIGHT 5 Sheets-Sheet 2 Filed April 12. 1954 i WIIIIIII/II/IIII/Ifl/A INVENTOR. kEIlUTL JIL E- Pin ATTORNEYS y 1957 H. E. PINKERTON, JR 2,792,632

CAM ACTUATED SIGHT Filed April 12, 1954 v 5 Sheets-Sheet 3 INVEN TOR H UTI y El iTLk E finIL Jr.

ATTORNEYS y 1957 H. E. PINKERTON, JR 2,792,632

CAM ACTUATED SIGHT Filed April 12, 1954 5 Sheets-Sheet 4 IN V EN TOR.

' 97 I HuTTyE PiI1kEI El I1 J1.

ATTORNEYS y 1957 H. E. PINKERTON, JR 2,792,632

CAM ACTUATED SIGHT Filed April 12, 1954 5 ShetS-SIISGT. 5

Ti c111- m g 1% as INVEN TOR.

H HnTryEPh-Lkgflnnlt A TTOENE Y5- United States Patent i CAM ACTUATED sronr Harry E. Pinkerton, Jr., Oyster Bay, N. Y., assignor to the United States of America as represented by the Secretary of the Army Application April 12, 1954, Serial No. 422,702

11 Claims. (Cl. 33-56) This invention relates to sighting devices for shoulder arms and is more particularly directed to adjustment means therefor.

Sights for firearms are necessarily adjustable to cornpensate for the wind deflection of the bullet and for the range of the target and it is conventional for the adjustment means to be provided on the rear sight because of convenience. In prior art, range adjustments on the rear sight are generally cam actuated. These cams are usually either of linear thread type, which, it is obvious, cannot translate the nonlinearity of a bullets trajectory into uniform increments of adjustment, or of inclined plane type which call for the sight to rise on the path of an arc, which, it has been demonstrated, causes eye fatigue and visual errors.

Further, it is generally acknowledged that the restricted aperture type of rear sight, commonly known as peep sight, is especially well adapted for precision sighting as color contrasts, and consequently target definitions, are intensified thereby while also employing the advantages of peripheral centering. These benefits, however, are achieved at the cost of target objective size. That is to say, as the size of the aperture is decreased, the size of the target as viewed through the aperture is likewise decreased.

Moreover, with unavoidable variations in the structures of the sight units and firearms, means must be provided for zeroing a sight after being mounted on a firearm and it is desirable that the zeroing be easily accomplished in the field.

It is, therefore, an object of this invention to provide for small arms precision sighting means which are compact, rugged and easily adjusted.

It is another object of this invention to provide a magnifying lens associated with the front sight to compensate for the reduction in size of the target as seen through the aperture when a rear peep sight is used.

It is a further object of this invention to provide simple, easily actuated range and windage zeroing means for rear sights.

It is the specific object of this invention to provide in a rear sight a range adjustment device having an actuating cam contoured to translate the predetermined trajectory of a bullet into uniform linear increments of distance.

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

Fig. l is a perspective side view of the receiver portion of a firearm with the rear sight installed thereto;

Fig. 2 is a perspective side view of the front end of the firearm with the monocle sight unit mounted thereto;

Fig. 3 is a perspective exploded view of the monocle sight unit;

Fig. 4 is an enlarged partially sectioned top view of the rear sight;

Patented May 21, 1957 ice Fig. 5 is an enlarged partially sectioned side view of the rear sight;

Fig. 6 is an enlarged perspective exploded view of the rear sight;

Fig. 7 is an enlarged perspective view of the cam member rotated to another position to show the mounting grooves provided thereon;

Fig. 8 is an enlarged perspective view of the peep sight member;

Fig. 9 is an enlarged perspective exploded view of an alternate embodiment;

Fig. 10 is a top partially sectioned view of the alternate embodiment;

Fig. 11 is an enlarged view taken along line 1111 of Fig. 10;

Fig. 12 is an enlarged partially sectioned view of the alternate embodiment; and

Fig. 13 is an enlarged bottom view of the alternate embodiment.

Shown in the figures is a shoulder arm of the type of the U. S. Rifle Cal. .30 Ml having a barrel 12 and a receiver 13. Projecting upwardly from the top side of receiver 13 is a rearwardly opening, substantially U-shaped housing 14 having laterally spaced longitudinal walls 15 which form a recess 16 therebetween. Walls 15 terminate rearwardly in semicylindrical ear portions 17 having laterally aligned holes 18 provided therethrough. Mounted for slidable lateral movement in recess 16 is a rear sight member 19 having a substantially rectangular body portion 20 and a cylindrical portion 21 which extends vertically upward from the rear end thereof. Arcuate fender portions 22 encircle the rear and top portions of ear portions 17.

Rotatably mounted in the left one of holes 18 is a windage zeroing actuator member 23 having a head portion 24, suitably slotted, as noted at 25, to receive the extractor rim of a cartridge or other means for turning, an adjoining cylindrical bearing portion 26, rotatably received by such hole 18, a toothed portion 27, spaced from the bearing portion by an annular groove 28, and a cuplike cylindrical well 29, extending inwardly from the end of the tooth portion. Encircling such one of holes 18 is a series of 30 uniformly spaced diametrical serrations 30 which cooperate with a pair of diametrically opposed detents 31 provided on the inside of head portion 24. One thirtieth of a turn (each click) of windage zeroing actuator member 23 represents one fifth of one mil of angular change thus providing measurable windage zeromg.

Rotatably mounted in the right one of holes 18 is a windage adjustment actuator 32 having a knob portion 33, an adjoining cylindrical portion 34 engageable with the outside of the adjacent wall 15, a cylindrical bearing surface 35 arranged for rotation in such hole 18 and a threaded portion 36, spaced from bearing surface 35 by an annular groove 37 similar to groove 28. Provided on the inside of cylindrical portion 34 are four regularly spaced lands 56 mateable with recesses 71 spaced around such one of holes 18.

Each quarter turn (one click) of windage adjustment actuator 32 represents one mil of angular relationship change with respect to a front sight 126 and the target objective thus providing measurable windage adjustment without scale reference necessity. Portion 36 is arranged to be threadably received by a lateral bore 38 through body portion 20 and is terminated by a journal portion 39 which is rotatably received by well 29.

Windage adjustment actuator 32 is held resiliently in union with windage zeroing actuator 23 while lands 56 are releasably held in recesses 71 and detents 31 in serrations 30, by a substantially U-shaped spring 40 receivable greases within recess 16. Spring 40 is provided with bifurcated ends 41 which are receivable by grooves 37 and 28 whereby members 32 and 23 are held resiliently together and are also separately rotatable. The engagement of the lateral portion of spring 40 with the lateral wall of housing 14 secure-s bifurcated ends 41 in engagement with grooves 37 and 28.

Spring 40 is maintained in engagement with the lateral wall of housing 14 by a dust cover 47. Dust cover 47 is arranged to close the top of housing 14 and is provided with a pair of ear portions 141 which depend vertically from the longitudinal sides thereof. Each ear portion 141 is provided with an inwardly projecting dimple 142 which is arranged to be resiliently received by a mating protrusion 143 in the longitudinal portions of spring 40. Whereby, dust cover 47 is resiliently secured to housing 14 and also stresses spring 40 to increase the pressure applied by bifurcated ends 41 to windage adjustment actuator 32 and windage zeroing actuator 23. Dusfcover 47 is removable by the insertion of the extractor rim of a cartridge under the rear side thereof.

Provided laterally through body portion 20, rearwardly of bore 38, is a cylindrical hole 42 which slidingly receives a drive member 43. Such drive member 43 is comprised of a threaded shaft portion 44, the ends of which terminate closely adjacent the insides of walls 15 to prevent lateral movement of such drive member, and a gear portion 45 arranged on one end thereof to mate with toothed portion 27. A spring-biased plunger 46 extends downwardly from the bottom side of base portion 20 to bear against the bottom side of recess 16 for 50 which receives, for vertical movement therein, a cylindrical cam member 49 with a peep sight member 48 mounted therein as described hereinafter. A slot 51 is arranged laterally through the rear portion of cylindrical portion 21 to provide forward communication with bore 50 and to form with the bore end portions 52 on both sides thereof. A lateral slot 53 extends forwardly from bore 50, in alignment with the top side of slot 51, to communicate with hole 42. Extending radially into bore 50 from the side of cylindrical body portion 21, above slot 51, is a passage 54 wherein there is received a pressed pin 55 which projects into such bore.

Mounted in the bottom of slot 51, so as to rotate about cam member 49, is a collar-like range adjustment member 57 the outside of which is approximately flush with the adjacent surface of cylindrical body portion 21. Extending radially from range adjustment member 57 is an arm portion 58 which provides the manual rotating means therefor. ber 57 is limited by the movement of arm portion 58 between end portions 52, which is approximately 180. Provided on that portion of the outside surface of adjustment member 57 which is visible in slot 51 between end portions 52 when arm portion 58 is central therebetween, are equally spaced graduations 10, numbered.

from 1 to 8, which represent one hundred to eight hundred yards of range. Provided in the surface of cylindrical portion 22 below slot 51 and central of end portions 52, is an incised reference mark 59 which aligns with the graduation l on range adjustment member 57 when arm portion 58 is engaged with the left one of end portions 52 and with the graduation 8 when the arm portion is engaged with the right one of the end portions. Extending into the hollow portion of range adjustment member 57, adjacent arm 58, is a lug portion 60 and provided in the top side of the adjustment member, supplementing the graduated portion thereof, are thirty-two equally spaced notches 61. Such notches 61 are so spaced that four thereof equal the distance between each of the graduations and so represent twentyfive yards of range. t

The rotation of range adjustment mem- Rotatably mounted on cam member 49 above range adjustment member 57, is a ring-like spacer member 62 comprised of two vertically related fixedly joined laminations 64 having lip portions 63 which engage end portions 52 to prevent rotation thereof. A detent 8, cooperable with notches 61, is provided in the central rear bottom side of the under one of the laminations 64 and a segment is removed from the top one of the laminations above such detent to give resilience thereto when cooperating with notches 61. Mounted on top of spacer member 62, so as to be rotatable about cam member 49 within aperture 53, is a ring-like windage zero indicator 65. Provided around approximately half of the outside surface of indicator 65 is a plurality of teeth 66 mateable with threaded shaft portion 44. Centrally disposed on the outside surface of zero indicator 65, opposite such teeth, is an incised index mark 67 which is alignable with a plurality of regularly spaced reference marks 9 provided on the outside surface of cylindrical portion 22 above slot 51. The central one of reference marks 9 is made larger for ready identification.

Thus, to zero peep sight 48 windage adjustment actuator 32 is rotated to move rear sight 19 in recess 16. When rear sight 19 is zeroed, windage zeroing actuator 23 is rotated causing toothed portion 27 thereon, through engagement with gear portion 45, to rotate drive member 43 which by worm gear engagement thereof with windage zero indicator 65 produces rotation of such indicator whereby index mark 67 is rotated to align with the central one of reference marks 9. Thereby, when rear sight 19 is actuated by adjustment actuator 32, the lateral movement of windage zero indicator 65 along drive member 43 causes rotation of the windage zero indicator and consequently index mark 67. The relationship of index mark 67 to reference marks 9 indicates the degree which rear sight 19 is moved away from zero position to compensate for wind deflection.

As has hereinbefore been noted, cam member 49 is cylindrical and is mounted for vertical movement in bore 50. A vertical channel 68 is provided in cam member 49 to cooperate with the projecting end of pin 55 for securing such member against rotational movement while providing for vertical movement thereof. Cam member 49 is assembled in bore 50 from the underside thereof. Therefore channel 68 is arranged to extend downwardly from the top side of cam member 49 for slidably receiving the end of pin 55 during installation of the cam memher. At the same time, another vertical channel 69 slidably receives lug 60 and guides such lug to a cam groove 70 which extends downwardly from the bottom end of the channel. Thereafter, rotation of range adjustment member 57 moves lug 60 along cam groove 70 to produce vertical movement of cam member 49 and consequently peep sight 48. When arm portion 58 is engaged with the left one of end portions 52, whereby graduation l is aligned with reference mark 59, peep sight 48 is in its lowest adjustable position, and when the arm portion is engaged with the right one of the end portion, whereby graduation 8 is aligned with the reference mark, the peep sight is in its highest adjustable position. During the travel of lug 60 along cam groove 70 to move peep sight 48, detent 8 of spacer 62 passes over the notches 61. As has hereinbefore been stated, each notch 61 represents 25 yards in the to 800 yards of the adjustable range of the sight and cam groove 70 is so contoured that when detent 65 is successively received in grooves 61, peep sight 48 aims the rifle on successive increments of 25 yards of range corrected to the predetermined trajectory of a bullet as affected by the ballistic characteristic of the ammunition. As the trajectory of a bullet is nonlinear, with the deviation thereof from linearity increasing with distance, cam groove 70 is consequently nonsymmetrical in contour.

Since cam groove 70 is helically generated to specifically reflect the trajectory with which it is employed greases and each point in the helix represents a definite range,

zeroing is accomplished independent of the cam-to-range relationship. Therefore, extending downwardly from the top of cam member 49 are a well 72, which is terminated by a wall portion 73, and a threaded bore 74, which communlcates by a vertical slot 75 with such well. Peep sight 48 is comprised of a cylindrical head portion 76, having a cylindrical aperture 77 provided axially therethrough, a hollow rod portion 78, extending from such head portion and arranged to be slidably receivable in well 72 and a key portion 79. Such key portion 79 extends radially from the side of rod portion 78 and is arranged to be slidably received through slot 75 into bore 74 to maintain aperture 77 in longitudinal alignment with barrel 12.

A compressible coil spring 80 is mounted in the hollow portion of rod portion 78 and bears against wall 73 to bias peep sight 48 upwardly. A set screw 82 is threadably mounted in bore 74 and engages key 79 to secure, and vertically adjust, peep sight 48 in well 72 whereby the peep sight may be zeroed for range adjustment. The bottom end of set screw 82 is provided with bisecting grooves 83 which resiliently receive the top side of key portion 79, which is formed in an apex, as noted at 84, to secure the set screw against rotation. Zeroing is easily accomplished by pressing downwardly on peep sight 48 to relieve apex 84 from grooves 83 whereby set screw 82 may then be easily turned as by an inserted match stick or other available soft solid shaft until peep sight 48 is adjusted to the proper elevation. Each quarter turn of set screw 82 (one click) represents one mil of elevation change with respect to front sight 126 and the target objective thus providing measurable range zeroing.

Figs. 9, 10, 11, 12 and 13 show an alternate means of mounting cam member 49 and associated peep sight 48 which is provided for those embodiments wherein lightness of weight is especially desirable but accuracy of sighting is also important. Shown in the figures is a mounting base 85 comprised of a substantially rectangular basal portion 91, which is received for slidable lateral movement in recess 16, and a cylindrical portion 92, which extends upwardly therefrom. Extending laterally from basal portion 91 are a cylindrical support member 86, which is received for slidable movement in the left one of holes 18, and an externally threaded rod member 87, which is receivable in the right one of holes 18 and is of smaller diameter than such hole. Rod 87 is provided with an axial cylindrical passageway 88 and a diametrical slot 89 along the length thereof which joins a recess 90 in the adjacent side of base 85.

Mounted for slidable movement in passageway 88 and slot 89 is a retainer member 93 which bears against a compressible coil spring 94 installed in such passageway ahead thereof. Retainer 93 is comprised of a pin portion 95 receivable by passageway 88, radially opposed wing portions 96 at one end thereof and a spherical knob portion 97 at the opposite end. When base 85 is assembled in recess 16, support member 86 is first inserted in the left one of holes 18 then retainer 93 is pressed into passageway 88 against the bias of spring 94 until knob portion 97 clears associated wall 15. Then, when rod 87 is aligned for entry into cooperating hole 18, the retainer is released permitting wing portions 96 to bear against the inside of the associated wall 15. Threadably mounted on that portion of rod 87 protruding from wall 15 is a windage adjustment knob 99 which is provided with a protruding shaft portion 100, which is receivable for rotatable movement in hole 18 but which does not extend all the way therethrough, and a rim portion 101 spaced from shaft portion 100 by an annular groove, not shown.

Shaft 100 is provided with an axial internally threaded portion 103 which is arranged to threadably receive rod 87 and which is terminated by a hole 104 of slightly larger diameter than knob portion 97. Provided through suitable passageways in windage adjustment 99 is a pair of parallel resilient wire members 105 which chordly intersect hole 104. Wires 105 are spaced slightly closer than the diameter of knob portion 97 and are so arranged that such knob portion may be pushed therethrough to rotatably secure retainer 93 to windage adjustment knob 99. In assembling, windage adjustment knob 99 is first mounted to rod 87 and then rotated thereon to pull base theretowards until wing portions 96 bottom in recess 90. Further rotation of windage adjustment knob 99 forces knob portion 97 through wires which resume normal position in back of the knob portion. Thus, wall 15 is secured resiliently between wing portions 96 and rim portion 101 so that rotation of windage adjustment knob 99 moves base 85 laterally in recess 16. Provided on rim portion 101 are land portions 106 which are mateable with recesses 71 in wall 15 for securing and indexing windage adjustment knob 99.

Provided in the rear side of basal portion 91 is a substantially rectangular recess 107 and extending laterally therefrom to the left side of the basal portion is a bore 108 which communicates with a threaded passageway 109 introduced from the rear side of the basal portion. A pin 110 is inserted through bore 108 into recess 107 and the portion received therein is bent vertically downward to form a pointer portion 112 which is adjustably movable in such recess. A lock 111, threadably mounted in passageway 109, secures pin 110 against movement after pointer portion 112 is moved to align with a suitable reference mark on receiver 13 after the sight is zeroed horizontally.

A bore 113 is provided vertically through semicylindrical portion 92 and basal portion 91 to slidably receive cam member 49 and a lateral slot 114 at the rear junction of such portions communicates with such bore. Rotatably mounted in slot 114 and bore 113 is a ring member 115 having a lug portion 116, receivable by cam groove 70 for vertical actuation of cam member 49 when the ring member is rotated, and an indexing arm portion 117 which extends rearwardly from slot 114. Provided along the top side of arm portion 117 is an incised line 118 which aligns with graduations on the outside surface of semicylindrical member 92 above slot 114, which are similar to graduations 10 described hereinbefore for the preferred embodiment.

Provided in the rear bottom side of ring member 115 are 32 regularly spaced notches 119, similar to notches 61, and extending upwardly from an oval hollow portion 120 in the bottom side of basal portion 91 is a detent pin 121 which is reciprocable in a cylindrical hole 122. An eye 139, through the end of detent pin 121 in recess 120, receives one end of a resilient wire member 123 which extends forwardly through a longitudinal hole 124 and then at right angles along a channel 125 to be held releasably therein by the reception of the free end of the wire member in a recess 140. Thus, resilient support is given to detent pin 121 for its cooperation with notches 119.

In Figs. 2 and 3 front sight 126 is shown with the conventional clamp screw replaced by a clamp screw 127 having a longer shank portion 128. Mounted for rotational and slidable movement on shank portion 128 is a lens assembly 129 which is biased against front sight 126 by a spring 130. Assembly 129 is comprised of a body portion 131 having a longitudinal bore 132, provided with a forward annular flange 133, which receives a lens 134. Lens 134 is positioned against flange 133 and retained thereagainst by a retainer member 135 resiliently held against body 131 by spring 130. Provided in the front side of body 131 are vertical, laterally spaced flanges 136 arranged to receive the rear side of front sight 126 therebetween whereby assembly 129 is replaceably positioned in central alignment with blade 137 of front sight 126. Thus, a rearward pull on assembly 129 against spring relieves flanges 136 from rear sight 126 and permits the assembly to be rotated to either side out of the line of sight.

For the average user, lens 134 is preferably of +50 diopter at the sight distant of the U. S. Rifle M1. It has been found that the restriction of forward view caused by the aperture type sight increases the range of accommodation of the normal user to such an extent that the lens of the human eye will resolve, within the sight distance of the rifle, refractions from lens power up to +.50 diopter (approximately 80 inch focal length) with ease.

From the foregoing, it is readily apparent that there is here provided a novel cam lift range member for a rifle sight whereby the nonlinearity of a predetermined bullet trajectory is translated in terms of uniform increments of adjustment corresponding to uniform increments of range. Further, the means of range and windage zeroing are simple and easily accomplished in the field if necessary and the disadvantages of the aperture type rear sight are overcome herein by a monoele type front sight which is light in weight and which may be readily rotated out of the line of sight if the lens therein becomes smeared or otherwise ineffective. Moreover, the sights are distinguished by their toolless adjustments, assembly and disassembly.

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. 1

I claim:

1. A sight for a firearm including a base, a cylindrical member vertically reciprocal in said base, said cylindrical member being provided with a helical cam having a nonsymmetrical contour, an adjustment member rotatable in uniform increments of adjustment about said cylindrical member, said adjustment member being engaged t usaidjam,,fgrmsguv t nshsaidwin wrotation thereoftoyertical adjustment of said cylindrical member,

the contour of said cam bein g' soarrangedthat-said"'in-' cremental adjustment of said adjustment member adjusts a sight means on said cylindrical member to corresponding increments of range conforming to a predetermined trajectory, and means for elevational adjustment of said 'srgiithfdans in said cylindrical member.

2. A sight for a firearm including a base, a cylindrical member vertically reciprocal in said base, said cylindrical member being provided with a helical cam having a nonsymmetrical contour, an adjustment member rotatable in uniform increments of adjustment about said cylindrical member, said adjustment member being engaged to said cam for converting said incremental rotation thereof to vertical adjustment of said cylindrical member, the contour of said cam being so arranged that said incremental adjustment of said adjustment member adjusts a sight means on said cylindrical member to corresponding increments of range conforming to a predetermined trajectory, means for obtaining measurable elevational zero adjustment of said sight means in said cylindrical member, rotatable screw means arranged to provide measurable windage adjustment of said sight, and a movable index line adjustable to the line of fire of the firearm for adjustably zeroing said sight laterally to the firearm.

3. A sight for a firearm including a base having a vertical bore and a transverse semicircular slot communicating forwardly thereinto, a cylindrical member mounted for non-rotatable slidable movement in said bore, a sight member mounted for adjustable elevation in said cylindrical member, a helical cam groove in said cylindrical member, an adjustment member rotatable in said slot about said cylindrical member, said adjustment member being provided with a plurality of uniformly spaced graduations visible in said slot and a plurality of regularly spaced serrations on the top side thereof, said graduations referring to divisions of a range and said serrations being in regular subdivisions of said graduations, an arm master portion extending from said adjustment member through said slot to provide rotating means therefor, a spacer mounted on said cylindrical member above said adjustment member, said spacer being comprised of a pair of laminated resilient plates, a detent portion extending downwardly from the bottom one of said plates below an incompleted portion of the top one thereof for resilient cooperation with said serrations whereby said adjustment member is indexable at regularly spaced intervals, and said cam being arranged to convert said intervals of rotation of said adjustment member to vertical movement of said cylindrical member for adjusting said sight member to corresponding increments of range corrected to a predetermined trajectory.

4. A sight for a firearm including a base, a cylindrical member vertically reciprocable in said base, a bore and a threaded hole vertically disposed in said cylindrical member in parallel relationship, a vertical slot providing communication between said bore and said hole, a sight member comprised of a head portion with an aperture therethrough, a shaft portion arranged for slidable movement in said bore and a pin portion extending from said shaft portion for slidable movement in said slot for maintaining said aperture in longitudinal alignment with the firearm, a spring arranged to bias said sight member for elevation in said bore, a screw threadably received by said hole to bear against said pin portion for elevational adjustment of said sight member, detent means cooperating with said spring for indexing and securing said sight member, a helical cam in said cylindrical member, a ring rotatable in uniform increments of adjustment about said cylindrical portion, means for rotating said ring, a key portion extending from said ring for engagement with said cam, and said cam being so arranged that rotation of said ring in said rotational increments of adjustment is translated to vertical adjustment of said aperture for sighting the firearm in accordance with uniform increments of range conforming to a predetermined trajectory.

5. In a firearm, having a receiver provided with a rearwardly opening substantially U-shaped housing on the top side thereof, a recess in the housing and a pair of laterally aligned holes through the rear portions of the longtiudinal walls of the housing, a rear sight including a base arranged for slidable lateral movement in the recess, said base being provided with a vertical bore and transverse semicylindrical slot communicating forwardly thereinto, a cylindrical sight member arranged for slidable elevational movement in said bore, a circular adjustment member arranged for uniform increments of rotation about said sight member in said slot, cam means i on said sight member slidably engaged by said adjustment member for translating said increments of rotation to said sight member for elevational adjustment thereof to corresponding increments of range corrected to a predetermined trajectory, a ring mounted for rotation about said sight member above said adjustment member, said ring being provided with a reference mark on the out side thereof alignable with a series of graduations on the outside of said base above said slot and a plurality of teeth opposite said reference mark, a windage adjustment member rotatably mounted in one of the holes in the housing, said windage adjustment member being comprised of a knob for turning, detent portions cooperable with regularly spaced grooves about the hole, a bearing portion rotatably received in such hole, a threaded portion arranged for a threadable passage through said base to obtain lateral movement of said sight, an annular groove between said bearing portion and said threaded portion and a journal portion terminating said threaded portion, a windage zero actuator rotatably received in the op posite hole, said windage zero acuator being comprised of a head portion suitably slotted for turning, a cylindrical portion rotatably received by such hole, a gear portion, an annular recess between said gear portion and said cylindrical portion and a lateral well arranged to rotatably receive said journal, a substantially U-shaped resilient means receivable in the recess, bifurcated portions on each end of said resilient means arranged to receive said annular groove and said annular recess portions for holding said windage adjustor and said windage zero actuator in union with each other while being separately rotatable and to cooperate with said detent and said associated grooves, a threaded drive member transversely mounted through said base and arranged to mate with said teeth in said ring for rotation thereof, said shaft arranged to be held against lateral movement by engagement with the walls of the housing during lateral movement of said sight by said windage adjustment member thereby rotating said reference mark, and a serrated portion on said drive member arranged to mate with said gear portion whereby rotation of said windage zero actuator rotates said reference mark.

6. A sight for a firearm including a base having a recess in the bottom side thereof, a vertical bore and a transverse semicylindrical slot communicating forwardly into said bore, a cylindrical member mounted for nonrotatable slidable movement in said bore, a sight member mounted for adjustable elevation in said cylindrical member, a helical cam generated in said cylindrical member, an adjustment member rotatable about said cylindrical member in said slot, sai-d adjustment member being provided with a key portion disposed for slidable engagement with said cam whereby rotation of said adjustment member moves said cylindrical member in said bore, an arm portion extending from said adjustment member through said slot and having a reference mark therealong alignable with a series of regularly spaced graduations on said base referring to range adjustments of said sight, and a plurality of notches on the bottom side thereof spaced in regular subdivisions of said graduations, a reciprocable pin extending upwardly from said recess to cooperate with said notches for securing and indexing said adjustment member, a linear spring having one end anchored in said recess and the other end received by a hole in said pin whereby said pin is resiliently pressed into said notches, a rod member having a pointer portion at one end mounted for adjustable lateral movement in said base, means for securing said rod member in a selected position, and said cam being so generated that rotation of said adjustment member between said notches adjusts said sight in accordance with said cam to obtain corresponding increments of range elevation conforming to a predetermined trajectory.

7. In a firearm having a receiver with a pair of longitudinal laterallyspaced walls upstanding therefrom and laterally aligned holes in the walls, a rear sight including a base member mounted for slidable lateral movement between the walls, a cylindrical member extending laterally from said base for slidable reception in one of the holes, an externally threaded rod member extending laterally from said base in alignment with the other one of the holes, said rod being provided with an axial well and a diametrical slot therealong, an adjustment knob provided with an axial bore having a portion arranged to threadably receive said rod and a portion of smaller diameter extending therefrom through said knob, a bearing portion rotatably received by the other hole and a rim provided with regularly spaced lands matingly receivable in corresponding grooves around such hole, a pair of parallelly spaced flexible pins arranged to chordly intersect said small diameter, a retainer having a shaft with oppositely disposed wing portions extending radially from one end thereof and a spherical portion at the other end which is pressable between said pins to rotatably secure said knob to said retainer, said retainer being slidably mounted in said well with said wing portions protruding through said slot to engage the inside Of the associated wall while said knob is rotatably secured to said retainer on the outside of such wall, a spring mounted in said well to bear against said retainer whereby said retainer and said adjustment knob are held resiliently against the associated wall and said lands are resiliently held in said groove and whereby said sight is adjustable in regular increments for lateral movement between the walls, a sight member arranged for elevational movement in said base, an adjustor rotatable in uniform increments of adjustment about said sight member, and cam means whereby said adjustor adjustably elevates said sight member in accordance with said cam to obtain uniform increments of range conforming to a predetermined trajectory.

8. In a firearm having a housing comprised of a pair of spaced longitudinal walls, a lateral wall joining the front ends of the longitudinal walls and laterally aligned holes through such longitudinal walls, a rear sight member mounted for adjustable lateral movement in the housing and including a first adjustment member rotatably mounted in one of the holes and arranged to adjustably move said sight laterally in the housing and a second adjustment member rotatably mounted in the other one of the holes and arranged to zero said sight laterally to the line of fire of the firearm, said first adjustment member and said second adjustment member being provided with annular grooves adjacent the insides of the longitudinal walls, said first adjustment member being terminated by a journal portion arranged to be rotatably received by a well portion in the adjacent end of said second adjustment member, a U-shaped resilient member provided with bifurcated ends receivable by said grooves whereby said first adjustment member is resiliently held in rotatable engagement with said second adjustment member, saidresilient member being arranged to be received within the housing whereby the engagement of the lateral portion of said resilient member with the lateral wall of the housing secures said bifurcated ends in engagement with said grooves, and a cover arranged to close the top of the housing, said cover being provided with an ear portion depending from each of the longitudinal sides thereof, each of said ear portions having an inwardly projecting dimple arranged to receive a mating projection portion provided in each of the longitudinal arm portions of said member whereby said cover is held resiliently in position and extra pressure is applied to said bifurcated ends to secure said first and second adjustment members in engagement.

9. In a firearm having a housing comprised of a pair of spaced longitudinal walls and a lateral wall joining the front ends of the longitudinal walls with laterally aligned holes provided through the longitudinal walls, a rear sight member including a base mounted for adjustable lateral movement in the housing, a windage adjustment actuator rotatably mounted in one of the holes and arranged to adjustably'move said sight in the housing, a windage zeroing actuator rotatably mounted to the other one of the holes, said windage zeroing actuator and said windage adjustment actuator being provided with annular grooves disposed adjacent the'insides of the longitudinal walls, said windage adjustment actuator being terminated by a journal portion arranged to be rotatably received by a lateral well portion in the adjacent end of said windage zeroing actuator, a U-shaped resilient member provided with bifurcated ends receivable by said grooves whereby said windage adjustment actuator is held resiliently in rotatable engagement with said windage zeroing actuator, said resilient member being arranged to be received within the housing whereby the engagement of the lateral portion of said resilient member with the lateral wall of the housing secures said bifurcated ends in engagement with said grooves, a cover arranged to close the top of the housing, said cover being provided with an ear portion depending from each of the longitudinal sides thereof, said ear portion having an inwardly projecting dimple arranged to receive a mating projection portion provided in each of the longitudinal arm portions of said member whereby said cover is held resiliently in position and extra pressure is applied to said bifurcated ends to secure said windage adjustment actuator to said windage zeroing actuator, a cylindrical member vertically reciprocal in said base, said cylindrical member being provided with a helical cam, an adjustment member rotatable in uniform increments of adjustment about said cylindrical member, said adjustment member being engaged to said cam for converting said incremental rotation thereof to vertical adjustment of said cylindrical member, said cam being so arranged that said incremental adjustment of said adjustment member adjusts a sight means on said cylindrical member to corresponding increments of range conforming to a predetermined trajectory, means for measurable elevational zero adjustment of said sight means in said cylindrical member, and a windage zeroing indicator rotatable about said cylindrical member and arranged for actuation by said windage zeroing actuator.

10. A sight for a firearm including a base, a cylindrical member vertically reciprocable in said base, a bore and a threaded hole vertically disposed in said cylindrical member in parallel relationship, a vertical slot providing communication between said bore and said hole, a sight member comprised of a head portion with an aperture therethrough, a shaft portion arranged for slidable movement in said bore and a pin portion extending from said shaft portion for slidable movement in said slot for maintaining said aperture in longitudinal alignment with the firearm, a spring arranged to'bias said sight member for elevation in said bore, a screw threadably received by said hole to bear against said pin portion for elevational adjustment of said sight member, detent means cooperating with said spring for indexing and securing said sight member, a helical cam in said cylindrical member, a ring rotatable in uniform increments of adjustment about said cylindrical portion, means for rotating said ring, a key portion extending from said ring for engagement with said cam, and said cam being so arranged that rotation of said ring in said rotational increments of adjustment is translated to vertical adjustment of said aperture for sighting the firearm in accordance with uniform increments of range conforming to a predetermined trajectory, screw means for adjusting said sight laterally for wind reflection, and a movable index line adjustable independent of said screw means for zeroing said sight laterally to the line of fire of the firearm.

11. A sight for a firearm including a base, a cylindrical member vertically reciprocable in said base, a bore and a threaded hole vertically disposed in said cylindrical member in parallel relationship, a vertical slot providing communication between said bore and said hole, a sight member comprising a head portion with an aperture therethrough, a shaft portion arranged for slidable movement in said bore and a pin portion extending from said shaft portion for slidable movement in said slot for maintaining said aperture in longitudinal alignment with the firearm, a spring arranged to bias said sight member for elevation in said bore, a screw threadablyreceived by said hole to bear against said pin portion for elevational adjustment of said sight member, a first detentmeans cooperating with said spring for indexing and securing said sight member, a helical cam in said cylindrical member, a ring rotatable in uniform increments of adjustment about said cylindrical portion, means for rotating said ring, a key portion extending from said ring for engagement with said cam, and said cam being so arranged that rotation of said ring in said rotational increments of adjustment is translated to vertical adjustment of said aperture for sighting the firearm in accordance with uniform increments of range conforming to a predetermined trajectory, screw means for adjusting said sight laterally for wind reflection, a second detent means for indexing and securing said screw means, a movable index line adjustably independent of said screw means for zeroing said sight laterally to the line of fire of the firearm, and a third detent means for indexing and securing said ring.

References Cited in the file of this patent UNITED STATES PATENTS 1,327,141 Bumpas et al. Jan. 6, 1920 1,428,115 Perrin Sept. 5, 1922 1,834,636 Pedersen Dec. 1, 1931 2,229,637 Burton J an. 28, 1941 2,445,087 Rogers July 13, 1948 2,531,421 Garand Nov. 28, 1950 2,639,507 Pachmayr May 26, 1953 FOREIGN PATENTS 12,180 Great Britain 1902 212,330 Great Britain Mar. 13, 1924

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