US3270418A

US3270418A - Rifle sight

Info

Publication number: US3270418A
Application number: US361402A
Authority: US
Inventors: Robert A Simeone; Anthony B Simeone
Original assignee: Individual
Current assignee: Individual
Priority date: 1964-04-21
Filing date: 1964-04-21
Publication date: 1966-09-06
Anticipated expiration: 1983-09-06
Also published as: BE656216A; GB1073520A; DE1428740A1

Description

Sept.6,1966 "R. Apmohimp 3,270,418-

RIFLE smm' Filed April 21,1964

FIG.2 W

INVENTORS QBERT A I m? HONY a 5122?? BY 2a X/{f ATTORNEY 3,270,418 RIFLE SIGHT Robert A. Simeone, 121 Linwood St., Milford, Conn., and

Anthony B. Simeone, 100 Broadfield Road, Hamden,

Conn.

Filed Apr. 21, 1964, Ser. No. 361,402

3 Claims. (Cl. 33-56) This invention relates to an improved gun sight and more particularly to an improved sight of the general type cover by our Patent 2,881,524.

The sighting of a gun, and particularly of a rifle, often has to be readjusted for distance, and when used in hunting this adjustment must be effected extremely rapidly and preferably without having to take the shooters right hand and trigger finger away from the gun. "Unless this can be done precisely and very rapidly with one hand the gun can often not be accurately aimed at rapidly moving game.

In the past various gun sights have been adjusted in small discrete increments, referred to as clicks from the audible noise-made. In other words if a rifle is properly sighted for a hundred yards and must then be sighted for two hundred or two hundred and fifty yards the sight must be raised by a definite number of clicks. Unfortunately this is not a simple matter because the trajectory of the rifle bullet is in the form of a parabola which is drastically modified by the effect of air resistance on the bullet after it leaves the muzzle of the gun. Needless to say the trajectory is in the form of a curve of a highly nonlinear equation. The clicks however are linear. The number of clicks .to transform the sighting from 100 yards to 200 yards is considerably less than that required to transfer the sighting from 200 to 300 yards and so on. Of course tables are available for particular rifle calibers and particular loads of propellant explosives, and if the shooter memorizes these tables he can rapidly count clicks. In practice however this has not proved practical except for target shooting where there is unlimited time to check a table. As a result there has been no practical gun sight Which could be adjusted quickly and accurately to meet the many varieties of ballistic trajectories.

Our prior patent, referred to above, dealt with an attempt to solve this problem. Essentially in the patent the sight itself, such as the common peep sight, was mounted on an L-shaped bracekt capable of moving up and down. The bracket extended down over along the receiver of the rifle, and was provided with a driving pin. It moved in a metal member with a suitable dovetailed groove to assure against lateral play, this member being bolted to the receiver. Two other disc shaped members were bolted to a central opening in the same member referred to above, one of them with a spiral groove of more or less arbitrary shape. This disc could be turned by a second disc attached thereto through two screws in slots to permit relative movement of the second disc which was cup shaped and carried indicia on its outer periphery. When the disc with the spiral is turned the pin on the sight bracket which engages with the spiral groove is moved up carrying the sight with it. As the spiral groove was to some extent arbitrarily chosen the indicia did not form a linear scale. But once proper adjustment had been there is no problem of adjusting a cap or of dealing with a scale which at best is nonlinear.

made the sight could be rapidly moved by the shooter by turning the discs and observing the indicia against a fixed mark on the receiver.

Our prior patent represented a great advance in rapid sighting but suffered from a serious problem. It is with an improvement of the type of sight just described that the present invention deals.

Two drawbacks were the arbitrary choice of spiral groove and the adjustment method which was very coarse and very slow. Also the adjustment could not be brought back readily and easily to a particular position. In the present invention the cap and groove disc form a unitary structure, which will be referred to as a rotatable cam member, and there is provided'a linear scale. The groove groove spiral is chosen so that it is an'accurate involute of the actual trajectory. Now the linear scale, which is easily read, corresponds to a linear sighting range and In the present invention the member in which the sight bracket moves is not bolted to the receiver of-the rifle but in turn slides in a dovetail groove on an additional memberwhich is bolted to the gun. This second member'is provided with a micrometer screw abutting against the sliding member carrying the grooved disc and permitting a precise vertical adjustment thereof for initial setting or zeroing in. As the micrometer screw head carries a scale it is easy to readjust toa particular value.

The reasons for the improvement obtained with the present invention lie in the fact that the trajectory of the bullet is enormously affected by the retarding action of the atmosphere. This increases so rapidly, as the cube of muzzle velocity, that the actual trajectory is changed only a little by changing muzzle velocity with the same type of gun, that is to say the same caliber and general bullet configuration. Thus variations due to propellant charge can be very closely approximated by an actual linear displacement of the spiral groove. Putting it another way the present invention was made possible by the fact that the trajectories of the same caliber and type of bullet with different loads of propellantwere a practically parallel family of curves. Accordingly, the drastic departure from ideal trajectory, a true parabola in.a vacuum, has been used in the present invention to make possible a simple adjustment for different propellant loads without upsetting the accuracy of the linear scale on the grooved element which is turned. The present invention therefore represents a rather unusual case where a theoretical enormous complication of the trajectory is made to perform a highly useful effect. Ordinarily when ideal conditions are departed from compensation is required. In the present case this does not occur and the sight of the present invention, which is extremely accurate with various loads in actual shooting through the atmosphere, would be completely inoperative *under ideal conditions in a vacuum. Ditffferent loads would then change the parabola completely because the shape of a parabolic trajectory is determ-ineduniquely by initial velocity and the value of gravity and no sight can be made which performs the valuable additional functions that are possible in the present sight.

i i -t i It is not possible to use the same sight forf guns of the present invention adds no complication thereto.

It has been stated above that the present invention includes as one of, its essential features that the spiral groove be an accurate involute of ,the actualtrajectory. This presents no particular problems for each groove for each caliber. While it might be thought theoretically possible to compute mathematically the shape of the spiral, in practice this is extremely difficult and it is much simpler and cheaper to determine the involute experimentally by firing a gun from a machine rest at different distances. These show the amount by. which the sight has to be raised for each range and these points then permit graphically laying out the shape of the spiral groove with ease in accordance with ordinary machine design. Of course once a groove for a particular spiral is determined it is simplicity itself to reproduce it as many times as is desired.

It has been pointed out above that a linear displacement of the member carrying the spiral permits corrections for different propellant loads. This is one of the important practical advantages of the present invention but it presupposes that the same caliber gun will have a bullet. of more or less comparable characteristics. Sometimes there may be special ammunition or special guns which sufficiently change the bullet characteristics so that it is behaving very much as a different caliber. In such cases it is very cheap to replace the member having the groove with another one having a somewhat different spiral groove corresponding to atypical ammunition. As this element is bolted on quickly with a central screw such interchanging can be 7 effected rapidly, and thus the present sight is useful even where there may be occasional uses of highly atypical ammunition.

It will be noted from what is stated above that the correction for ammunition load by means of a micrometer screw is really a correction for muzzle velocity. With guns of the same type, for instance of the same barrel length, all that is needed is a table for screw settings with different loads. barrel length as well as propellent load an adjustment of the micrometer screw is necessary in going from a gun of one barrel length to one of a very different one. This however presents no problem as a table of micrometer screw scale settings for the new type of gum is furnished with it and it is perfectly simple to set the screw accordingly. This is an added advantage of the present invention which permits adjustment to barrel length in a simple manner and with great precision. 4

The invention will be described ingreater detail in conjunction with the drawings in which:

FIG. 1 is an isometric view with a sight shown exploded so that the various members are separated, and

FIG. 2 is a section through FIG. 1 along the line 2-2.

The gun receiver is shown at 1. To the receiver there is bolted a member 5 fastened with two bolts 6 and provided with a dovetail groove 7. This member is not shown exploded in FIG. 1 but is shown in its actual position bolted to the gun receiver. The member 5 is provided with an extension from which a micrometer screw 2 extends with a head 3 having on its periphery a l The next member'8 slides in the dovetailed groove of member 5 the slide being the male dovetail 9. The bottom of this member when assembled strikes the end of the micrometer screw 2 and can be moved with respect to member 5 a definite predetermined amount by means of the screw.

The other side of the member 8 carries a female dove- Since the muzzle velocity is effected bytail or groove 10 and in this slides an L-shaped bracket 13 carrying a peep sight 11 in a slot 12, thmsight beingmoveable laterallycfopwindage b means of the screwi ti This wiridage adjustment is one of many conventional types and is not significantly. changed by the present invention. Of course its mounting must be s uitable for the L-shaped bracket 13. The bracket carries a. pin 15 and central slot 16. The pin engages spiral groove 20 in a disc 19, in the form approximately of an involute of the trajectory, which is rotatable and which is bolted to a member 17 by bolts 24. The member 17 carries on its periphery a scale 18. -All of the movable members except the bracket 13 are-screwed together with a screw 21 engaging a threaded recess 22 in the member-8. The screw 21 extends-through the slot 16 of the bracket13, the length of the slot corresponding to maximum movement of the'bracket 13. v g

In use the sight is assembled, the micrometer screw 3 adjusted or zeroed in, at any known distance for the particular ammunition load and barrel length of the gun and then sighting is-effected" merely by turning the member 17, the scale 18 being readable against a mark 23 on the member 8. Change of range requires only turning of the member -17 with one hand until the correct range is read on the 'scale 18. This can be done very rapidly, particularly as 'the scale is linear. When the shooter wishes to use different ammunition, that is to say ammunition with a different propellant load, he merely adjusts the head 3 of the micrometer screw 2 to zero in, at any distance to which the member 17 is set.

The head 3 can be then set to the same reading whenever this particular kind of ammunition is. to be used under the same conditions, and the change forgotten and after any setting of the head 3 the sighting of the gun is effected precisely as before. It should be noted that

members

17 and 19 cohstitute single rigid structure which can be moved as a unit by adjustment of the screw 2. This is an additional advantage over the sight described in our earlier patent. In that sight it .was necessary to loosen two screws and move the cap with respect to the other portion .of the rotating member carrying the spiral groove, it is possible 'for the scale to become out of adjustment with the groove. In the sight of the present invention this cannot occur as scale and groove are part of a unitary whole, the

members

17 and 19 and no slippage is possible which can occur if the adjusting screws in our earlier patent become loose. This feature is of importance though not as basic as the precise involute shape of the spiral grooveand the possibility of micrometric adjust-ment. It is however an advantage of practical importance and makes it impossible for loosening of screws to throw the sight out of adjustment. It should be noted that the micrometer screw, as is the case with this typeof mechanism has so fine a pitch and it provided with a detent 25 so that it is, for-all practical purposes, self locking and will not move in ordinary use of the gun until the screw is deliberately turned to provide a new setting on the scale of its head 17.

When changing gun caliber screws-21 and 24 are unscrewed and anew disc 19 substituted with a groove of the proper involute shape for the trajectory of the new caliber.

We claim:

1. In a gun sight comprising a base plate adaptor to be secured to the receiver of the gun, a sight supporting member, means permitting vertical sliding of said member with respect to the base plate, said means including a rotatable cam member provided with a slot therein and a slot engaging projection on the sight supporting member,

the improvement which comprises,

(.a) the slot is in a form approximating an involute of the trajectory of a bullet of the particular gun caliber in air, (b) a member slidable vertically in the base-plate and carryingon its opposite face a gr0ove in which. the

5 6 sight supporting member is slidably mounted for one a cam slot carrying disc and the other a rotatable vertical movement, member carrying the linear scale. (c) micrometric adjusting means connecting the base plate to the member sliding therein and capable of References Cited y the Elam!!!" :liding (the meniber vertically in accurately prede- 5 UN STATES PATENTS ermine amoun s, ((1) means for attaching the cam member to the memgfig :3 sliding in the base plate to form a unitary whole, 2,671,966 3/1954 kcobscn et a1 (e) a direct reading linear scale on the periphery of 10 2881524 4/1959 Slmeone et a] 33-665 the cam member. FOREIGN PATENTS 2. A gun sight according to claim 1 in which the micrometric means is provided with a scale showing relative 12238 1909. ,Gmat Bmam' movement between the base plate and the member sliding LEONARD FORMAN Primary Examiner therein.

3. A gun sight according to claim 1 in which the ro- 15 HAROIAN, Assistant Examinertatable cam member is in two pieces bolted together,

Claims

1. IN A GUN SIGHT COMPRISING A BASE PLATE ADAPTOR TO BE SECURED TO THE RECEIVER OF THE GUN, A SIGHT SUPPORTING MEMBER, MEANS PERMITTING VERTICAL SLIDING OF SAID MEMBER WITH RESPECT TO THE BASE PLATE, SAID MEANS INCLUDING A ROTATABLE CAM MEMBER PROVIDED WITH A SLOT THEREIN AND A SLOT ENGAGING PROJECTION ON THE SIGHT SUPPORTING MEMBER, THE IMPROVEMENT WHICH COMPRISES, (A) THE SLOT IS IN A FORM APPROXIMATING AN INVOLUTE OF THE TRAJECTORY OF A BULLET OF THE PARTICULAR GUN CALIBER IN AIR, (B) A MEMBER SLIDABLY VERTICALLY IN THE BASE PLATE AND CARRYING ON ITS OPPOSITE FACE A GROOVE IN WHICH THE SIGHT SUPPORTING MEMBER IS SLIDABLY MOUNTED FOR VERTICAL MOVEMENT, (C) MICROMETRIC ADJUSTING MEANS CONNECTING THE BASE PLATE TO THE MEMBER SLIDING THEREIN AND CAPABLE OF SLIDING THE MEMBER VERTICALLY IN ACCURATELY PREDETERMINED AMOUNTS, (D) MEANS FOR ATTACHING THE CAM MEMBER TO THE MEMBER SLIDING IN THE BASE PLATE TO FORM A UNITARY WHOLE, AND (E) A DIRECT READING LINEAR SCALE ON THE PERIPHERY OF THE CAM MEMBER.