IL26187A - Sights for weapons - Google Patents

Description

\ C O H E N Z E D E K & S P I S B A C H EC D.. PAT E N T ATT O R N E YS 24, LEVONTIN STR., P. O. B. 1169 T E L - A V I V P A T E N T S & D E S I G N S O R D I N A N C E 15597/66 SPECIFICATION SIGHTS FOR WEAPONS We, PAUL VINCENT COATE and ALTON FRANK CARR, both citizens of U.S.A., of 11 Catherine Street, Milton and 60 Robinson Road, Woburn, both in the Commonwealth of Massachusetts, U.S.A., and NORRIS INDUSTRIES, INC., a corporation organized under the laws of the State of California, U.S.A., of 5215 South Boyle Avenue, City of Los Angeles, State of Calif ornia ,U.S .A (previously NORBIS-THERMADOR CORPORATION) DO HEREBY DECLARE the nafure of this invention and in what manner the same is to be performed to be particularly described and ascertained in and by the following statement : The present invention relates to sights for weapons and particularly to those for launchers for rockets utilizing solid propellants.

While it is well known that such weapons as firearms and rocket launchers must have sights that are adjustable to enable targets at different distances to be hit, such sights usually being also adjustable to compensate for the effects of wind on the projectile, the effects of heat have not been the object of much concern. This is true even though it is recog-nized that a firearm sighted in with a hot barrel, for example, may prove to be inaccurate when the barrel is cold.

With the use of solid propellants for rockets, it was observed that markedly different results followed any substantial temperature change. The results were that, as the temper-ature of the propellant decreased, the range of a rocket using that propellant was shortened with reference to a preselected normal while, as the temperature of that propellant increased, the rocket's range was extended relative thereto. In short, the effects of temperature changes are relatively the same, as far as sighting requirements, as changes in the distance to a target but are not as readily discerned.

As a consequence, there is a real demand to have sighting corrections made automatically in response to temperature changes and, in accordance with the invention such correc-tions are effected by means of a sight member that is raised or lowered by thermally responsive means in a predetermined direction and to a predetermined extent dependent on the temperature to which the element is subjected. While other types of thermally responsive means may be used, those that use bi-metallic and low cost. With a weapon having both front and rear. sights, the sight member, if the' rear sight, must raise on a drop of temperature, or, under these conditions, a front sight must be lowered. In the case of a rise in temperature, the rear sight must be lowered or the front sight elevated. A telescopic sight presents a situation similar to a rear sight.

While the actuation of a' sight by thermally responsive means must be in a predetermined relationship to the performance characteristics of the propellant, there is the added necessity that the sight must have its thermally responsive means shielded against being heated or cooled at a rate materi-■ ally faster or slower than the propellant to avoid over or under corrections, either of which would result in inaccurate sighting.

As it is desirable to have the thermally responsive means below the sight member and as the thermally responsive means must be operative or so connected to the sight members as to cause movement in a range-increasing direction as the temperature drops and vice versa, it Is required, in the case of a rear sight, for example, either that the thermally responsive means contract in response to increased temperature or that the connection between the thermally responsive means and the sight member produce movement in the same direction as such contracting thermally responsive means.

In accordance with the present invention there is provided a sight, comprising a mount, a sighting unit attached to the mount and including a vertically movable sight member and thermally responsive means connected thereto to cause the s o h si ht member relative to the mount to dependent on the temperature to which the means is subjected, and in a range-iAooldl-ng^direction when the temperature is rising.- In order that the invention may be more clearly understood and readil carried into effect, the same will now be described more fully with reference to the accompanying drawings, in which; - FIGURE 1 is. a diagrammatic view illustrating sighting requirements where the efficiency of a rocket propellant decreases with a decrease in temperature; FIGURE 2 is a rear perspective view of a rear sight in accordance with the invention; FIGURE 3 is a section, on an increased scale, taken approximately along the indicated lines 3—3 of Figure 2 FIGURE 4 is a side elevation, on a further increased scale, of the thermally responsive means of the sight shown in Figures 2 and 3; FIGURE 5 is a fragmentary elevation, on a further increase of scale, of the material of which the thermally responsive means, shown in Figures 3 and 4, is formed; FIGURE 6 is a section similar to Figure 3 illustrating an embodiment of the invention in which the thermally responsive means is in the form of a bi-metallic coil; and FIGURE 7 is a similar section illustrating another embodiment wherein the thermally responsive means is a U-shaped bi-metallic element.

Reference is first made to the fact that the propellant for rockets to be launch d from shoulder-su orted launch- mono-perforated sticks being most commonly used. The efficiency of such a propellant is a function of its temperature at the time it is ignited with the efficiency improving as the temperature rises and vice versa.

In Figure 1, a launcher is generally indicated at 10 and the path of its rocket 11 to the target 12 is indicated at N. The launcher 10 is shown as having a front sight 13, and a rear sight 14. While any type of front sight may be used, the front sight 13 is of a transparent plastic having, sighting indicia thereon as is fully detailed In the co-pending application of Paul V. Choate and Charles B. Weeks, Serial No. 151, 894, filed November 13, 1961, now United States Patent No. 3,122, 059. It is, of course, conventional for sighting arrangements to be adjustable to enable corrections to be made for different dis-tances and wind factors and the means for so doing are not herein shown as they form no part of the present invention. It is assumed that the sights of the launcher 10 are set with the path N being normal for the rocket 11 when the temperature of its propellant, just prior to being ignited, is in the order of say, 70°P.

As the temperature drops, the efficiency of the propellant decreases so that the path of the rocket, when the temperature of its propellant is at some temperature lower than 70°P. is indicated at C and passes below the target 12. As in the case of an increased range, it is now necessary to make correction by raising the muzzle of the launcher 10 as by raising the rear sight 14. As the temperature rises above the assumed temperature for which the path N is normal, the efficiency of the propellant increases so that the path .N of the temperature passes above the target 12, As In the case of a shorter range, it is now necessary to make corrections by lowering the muzzle of the rocket as by lowering the rear sight 14..

In accordance with the invention, the sight corrections are made, automatically so that · variations in propellant efficiency do not need to be considered in firing.

Referrin now to Figure 2, . it will be seen that the rear sight 14 consists of a mount 15 having its lower end forked as at 16 with the ends having ali ed apertures 17 for the transverse attaching pivot not -shown.. The mount 15 has an upwardly disposed, cylindrical, chamber 18 opening between the forked ends of the mount and. in communication with a transverse, vertical slot 19 intersected. by a fore-and-aft passage 20 provided with windows 21 and establishing the sight axis., it is preferred that- the windows 21 protrude slightly for ease in cleaning them., The sight member is shown as being in the form of a blade 22 having a peep aperture 23 and slidably guided in the slot 19 with its lower end. connected to thermally responsive means in the form of a helical element 24 formed from bimetallic stock 25 which 1B itself in the form of a helix, as may best be seen in Figure 4,, and is of the type contracting in response to temperature rises..

The element 24 is a free fit in an insulating sleeve . 26,. typically aluminum, fitted within the cylindrical chamber 18. . The lower end of the element 24 extends freely through a central hole In a disc 27 and is attached to a loose anchor 28 to revent bindin as the coil ex ands and contracts., A ca 2 In Figure 6, there Is shown another embodiment of the Invention and, for convenience, the same mount construction is used. Like "parts are distinguished from those of the embodi-r ment Just described by the suffix letter A. It will be noted that the blade 22A.is provided with a depending leg 30 havin a notch 31 in which is caught the free end 32 of a thermally responsive element in the form of a coil 33 of bi-metallic stock. The coil 33 has its other end secured to a cross bar 34 fastened to the interior of the shell 26A SO that the blade 22A is moved downwardly as the temperature increases and upwardly as the temperature drops.

Similarly, the embodiment of the invention illustrated by Figure 7 is shown as employing the same type of mount as has been described. Like parts are distinguished from those of the other embodiments by the suffix B. In the embodiment of Figure 7, the blade 22B has a diagonally disposed slot 35 through which extends a pin 36 at the upper end of a fork 37. The lower end of the fork 37 is eecured to the free end 38 of a thermally responsive element 39 of bi-metallic stock and approximately U-shaped with its yoke-carrying end moving away from its anchored end as the temperature drops. With a like element but having its yoke-carrying end moving in the opposite direction as the temperature drops, the slot 35 would be inclined in a direction opposite to that shown* As with the other embodiments of the invention, the blade 22B is pulled downwardly as the temperature rises and is elevated as the temperature drops.

With sights of the types disclosed, the blades move up and down in response to temperature changes. In practice, of the propellant as determined by temperature. It will be apparent that as the propellant is within the rocket and. the. rocket is within, the launcher while the sight is exposed, the thermally responsive means must be prevented from too promptly registering temperature changes and the aluminum sleeve is a simple and inexpensive means for so doing. Other types of insulating the thermally responsive means may, of course, be used.

From the foregoing it will be apparent that the invention makes possible sights which accurately adjust themselves to temperature changes in relation to the effect such changes have on accuracy.

Claims (6)

NORRIS - ISRAEL HL 16956 REP 3:13;70

1. A sight for a weapon, comprising a mount and a sight member vertically movable relative to the mount, the sight element being vertically adjustable relative to the mount in a range-increasing and range-decreasing direction when the temperature is falling and rising respectively, wherein the sight elemen is automaticall adjusted by a thermally responsive means connected thereto dependent on the temperature to which said means is subjected and the mount includes a chamber in which the thermally responsive means is housed, which chamber is insulated against the direct transfer of heat to the thermally responsive means.

2. A sight according to claim 1, wherein the chamber includes a heat reflecting shield surrounding the thermally responsive means.

3. A sight according to any one of the preceding claims wherein the thermally responsive means is below the sight member,

4. * A sight according to any one of the preceding claims, wherein the thermally responsive means is in the form of a U-shaped element of bl-metalllc stock, one arm of the element being free to move, the sight member has a diagonal slot, and the free arm of the U-shaped element includes a stud slidable in the diagonal slot and operable, as it slides therein, to move the sight member in a vertical direction.

5. A sight for a weapon substantially as herein described with reference to and as shown in the accompanying drawings.

6.. A rocket launcher provided with a sight according to any preceding claim.