US2364585A - Aiming device for automatic guns - Google Patents

Description

Dec. 5, 1944. w, MEYER 2,364,585

AIMING {DEVICE FOR AUTOMATIC GUNS Filed May 27, 1941 '2 Sheets-Sheet l 13111911101: W/u TEE M5 YER.

Dec. 5, 1944. w YER 2,364,585

AIMING DEVICE FOR AUTOMATIC GUNS Filed May 2'7 19 41 2 Sheets-Sheet 2 Fig. 4

lNVENTOR WALTER MEYER ATTYS.

Patented Dec. 5, 1944 AIMIN G DEVICE FOR AUTOMATIC GUNS Walter Meyer, Zurich, Switzerland Application May 27, 1941, Serial No. 395,461 In Switzerland May 22, 1940 4 Claims.

' i The known aiming devices for automatic guns used against aircraft consist substantially of two elements: the rear sight near to the eye, and the front sight farther away from the eye.

The rear sightis usually a spot and the front sight a ring or a multiplicity of concentric rings.

' 'The velocities of the aircraft and projectile are taken care of by aiming ahead of the craft a certain distance which may be predetermined. Assuming the velocities and the distance of the craft, it is possible to determine a combination of distance between spot and center of the sight rings and diameter of the latter (two rings may be used for instance for given aircraft velocities of 400 and 600 km./h.) To correct for the distance and allow for the ballistic of the projectile, one of the aiming elements is adjustable in the vertical 1 plan passing through the axis of the gun. In

order to point the gun correctly, it is necessary thatthe apparent trajectory of the craft seen by the gunner in the plan of the rings, become radial, that is, the gunner must by trial and error, place the gun in such a way that the spot lies on rapidity of the craft motion.

The object of the present invention consists in'a device materializing the projected straight line continually ori'entable in the plane of the rings, joining the projections of the spot and the ring center, and also giving a prolongation of I said straight line by an appreciable amount outside of the ring edge. This'disposition allows the gunnente catch visually the craft quite a time before it reaches the position in which it is judged desirable to fire the shots. The materialization of the straight radial line may consist of a rigid sliding rod, or a telescopic tube of small diameter, or an elastic element (rubber string or coil spring), or'a thread kept under tension by a weight, or a combination of any number of these elements, joining the spot to the ring center.

It is seen in this manner that any projection, in particular as seen from the gunners eye, is a visible'straight line joining the spot to the rin center. g

It is obvious that the object of this invention may be'applied to the well-known .periscopic arrangements consisting mainly of. two parallel light-reflecting surfaces (mirrors or prisms) One of these surfaces could bear the sighting rings engraved or otherwise marked.

The spot could be placed together with the material straight line between the two reflecting surfaces or between the eye and the first surface or between the second surface and the craft.

Fig. 1 is a diagram which shows the field of vision obtained by the gunner for a given azimuth.

Fig. 2 is a diagrammatic view of a periscopic arrangement of the sighting device.

Fig. 3 is a side elevation view of an embodiment of the sighting device.

Fig. 4 is a plan view of the device shown in Fig. 3.

Fig. 5 is a diagram similar to Fig. 1 showing further detail.

In Fig. 1, ll! represents the center of the circle of the front or ring sight as viewed by the gunner, H is the projection of a material straight line which extends outward beyond a point l2 which is the projection of the spot or rear sight. l3 represents the craft approaching the sighting field.

It is obviously not compulsory that the material line reach the ring center ll] if for any reason of design or manufacture this imposes difficulties.

As an illustration and without implying any restriction in the application of the invention, the following arrangement is described and shown in Figs. 3 and 4.

The front and back sights I9, 20, consisting respectively of a ring with center 24, and spot, are supported on a base plate which is attached to a suitable place on the gun or gun cradle by means of a clamping device with lever 3| whereby the line of sightbetween the spot 20 and the center of the ring 24 is properly located with respect to the axis of the gun barrel in all positions of the gun. A pair of curved supports 32 extend from the base 3%] and terminate at their outer ends in bosses 33 and 34, rigidly braced by a bar 35. In the bosses 33 and 34 are pivoted the arms 22, 2| supporting the sights 20, [9. The arm 22 supporting the spot 20 or back sight is straight and has a portion 22a, extending below the pivot 22!). The arm 2! carrying the sighting ring is with center 24 or front sight, has a forwardly and upwardly cranked portion and a straight portion 2la extending below the pivot 21b. The ends of the arm portions 22a, 2la are connected by a link 36 jointed at its ends to said firstsight is provided at the pivot 2212 with the usual adjusting means 38, whereby, in manner known per se, the sights receive a setting corresponding to the elevation of the gun. It will be understood that the sighting ring remains in fixed relationship to the horizontal plane while the spot 20 moves in the vertical plane passin through the vertical axis about which the gun pivots in aiming at the target, in accordance with the elevation of the gun, this movement being transmitted to the spot through the link mechanism described.

According to the present invention, a rod 23 extending from point 20 to the front is articulated to the center 24 of the ring [9 forming the front sight (and extends throughpoint 20 rearwardly through a bore in the spot 20 or rear sight.) The rod 23 materializes a line between the spot 20 and the center 24 and is seen by the gunner as a radial line extending from the center of the ring to the periphery through the spot 20 towards the target. The gun being always aimed at a point ahead of the aircraft, the center of the ring will be ahead of the target and the spot directed towards the same, and the horizontal and vertica1 aiming of the gun is controlled to bring the rod into alignment with the cours of the target. The projection of the rear portion rearwards of point 21] thus extends outside the periphery towards the target, allowing the target to be located on the trajectory of the bullet before the shot has to be fired. The moment the target covers the point where the projection of the rod 20, i9 crosses the periphery of 19, the shot is fired. The front or ring sight has outer and inner circles 19a, [9, and the image of the said radial line as seen by the gunner will appear to intersect the inner or both the inner and outer circle, according to the position of the sights, and can be readily pointed towards the target as indicated in Fig. l for the line H. When the image of the spot I2 lies on the outer circle, assuming that the estimated speed of flight of th target corresponds to the radius of this circle, the shot is fired. If the estimated speedor" flight corresponds to the radius of the inner circle, the firing is effected when the spot image lies on the inner circle, for intermediate speeds of flight the instant of firing can be readily estimated. The matrialization of a radial line formed by the rod 23 makes accurate sighting possible.

The periscopic arrangement shown in Fig. 2 is equivalent except that the line of sight l8 from the eye of the gunner is not direct, that is in a straight line, as in the device of Figs. 1, 3 and 4 but has two parallel portions one below the other whereby the portion extending from the gunners eye is below the portion extending through the front sight to the target in order to allow the gunner to occupy a protected position, as in a trench. The two parallel portions of the line of sight appear to be in alignment to the gunner owing to the interposition of the periscope with its prisms or oblique reflecting surfaces l5, It. The zigzag lin of sight l8, l8, l8, of Fig. 2, where I8 is the vertical portion provided by the said surfaces 15, H5, thus is seen by the gunner as a straight line and may beconsi'dered as such. The front sight or ring sight I9 is placed in the upper portion of the lin of sight directed at the target, and the rear or spot sight 20 is placed between the refiecting surfaces [5, 16 in the line 3, l8, [8. The rod 23, materializing a line between the spot 20 and the center 24 of the ring sight 20, is placed as shown in Fig. 2, also between the surfaces l5, l6 and in the vertical plane of the line of sight. Thus it is seen by the gunner in a relationship with the spot 20 and ring I9 exactly similar to the direct sighting line apparatus of Figs. 3 and 4.

Fig. 5 illustrates the sighting a carried out by either of the foregoing arrangements. The points A, B, C on the rod 23 represent its ends and the spot or rear sight 20. The eye of the gunner is at point E of Fig. 5, behind the point A, so as to be able to view the complete length of projection of the line A-C. Before the shot is fired, the gunner locates his eye at E of Fig. 5, so as to brin the projection A-C of the line A-C exactly in the flying direction of the aeroplane. All the gunner has to do then, is to wait until the target, in this case the aeroplane, has reached the point B along the projected line A'C. At this moment the shot is fired.

B is an imaginary point always on the projected lineof A--C, and it will be the intersection of this projection with the outer circle of the ring sight, if the velocity of the target corresponds with the velocity represented by the said circle of the ring sight.

This aiming device is distinguished by having the projection A, B, C extending outside the circles of the ring sight towards the target whereby the target can be followed on the projection of the line A-C even before th shot is fired. The gunner has ample time to prepare the gun and keep it sighted, following the flying direction of the target with the projection A'-C.

I claim:

l. Sighting mechanism for guns comprising: a bead member formingthe rear sight, a ring member forming the front sight, means for supporting said members on the gun in sighting relation thereto, means maintaining said ring member substantially horizontal irrespective of the angle of elevation of the gun, and a straight rod extending through said bead member and the center of said ring member, said rod bein slidable in one of said sighting members.

2. Sighting mechanism for guns comprising: a bead member, a ring member, means for supporting said members on the gun in sighting relation thereto, and a straight rod the axis of which extends through the centers of said bead member and said ring member whereby said rod appears to the gunner as a radial line extending from the center of said ring member through said head member towards the target, said rod being slidable in one of said sighting members.

3. Sighting mechanism according to claim 1 in which a periscope with upper and lower reflecting surfaces is arranged with the straight rod and the bead member between them.

4. A sighting mechanism for guns comprising a bead member forming the rear sight, 'a ringmember forming the front sight said ring member having a plurality of concentric circles of diameters corresponding to different speeds of target motion, means for supporting said members on the gun in sighting relation thereto, means maintainable in one of said sighting members and being of such length that when viewed by th gunner it appears to extend beyond the outermost circle of the front sight.

WALTER MEYER.

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