US2070788A - Regulatable fuse for projectiles - Google Patents

Description

Feb. 16, 1937. P. GIRARD REGULATABLE FUSE FOR PROJECTILES Filed Aug. zo, 1935 [Iwezzf/z@ PAUL GI RD Patented Feb. 16, 1937 PATET IC REGULATABLE FUSE FOR PROJECTILES Paul Girard,

Lyon, France Application August 20, 1935, Serial No. 36,947 In France August 24, 1934 3 Claims.

The present invention relates to the manufacture of shells, and particularly to a new regulatable fuse system obviating the marking of figures on the assembled shell.

In anti-aircraft firing, use is made with the greatest electiveness of mechanical time fuses in which the locking for resisting the effects of centrifugal force is at present obtained by the perforation of diaphragms by means of eccentric punches cutting eccentric holes in the position to be maintained during* the rotation of the projectile.

When it is considered that barrels for aerial firing are provided with grooves intended to impart to the projectiles during propulsion a speed of rotation of from 20,000 to 26,000 revolutions `per minute and that the effects of centrifugal force at these speeds is equivalent to a resultant lying between 4,000 and 6,000 grammes per gramme and millimetres of eccentricity, it will be understood that the manner in which usual types of apparatus are conceived is unreliable.

Moreover, with the known devices of this class the. exterior indications can only be defined by approximation.

In this device, the jacket of the shell is covered by a hood, which is movable about the axis of the said shell and, at the same time as winding a clockwork mechanism, carries along a graduated crown through the intermediary of a differential gear which reduces its movement, while the said graduation, the indications of which are visible from the exterior of the shellthrough an aperture provided in the hood indicates the number of turns made by it, the said ho'od also being provided, on its lower edge, with other graduations very widely spaced to facilitate reading of the same.

The invention also includes a system for locking the whole mechanism when the regulation has been effected, this locking being primarily effected by means of a central screw which ensures, by acting on a nut, positive friction between two cones and, secondly, by means of the automatic release, at the moment when the shell is fired, of a ring which, owing to its inertia, brings about the violent forcing of a washer against a fluted or toothed part, the said washer being connected to the clockwork mechanism and thus locking it.

'Ihe invention consequently also covers, by way of new industrial products, the fuses to which similar arrangements are applied.

It will in any case be readily understood with the aid of the following additional description and from the accompanying drawing in axial section, which description and drawing are, of course, given chiefly by way of example.

In the accompanying drawing A is the jacket of the shell. The movable hood B has on its lower edge a numbered graduation extending from l to 10. This hood may turn several times about its vertical axis (four times in the case of the drawing) to enable the graduations to be spaced as far apart as possible in order that they may be easily read. Through an aperture C provided in the hood, the number of revolutions of the latter may be seen from the ring D. The driving wheel E which, upon the circular movement of the hood, is moved horizontally about the core F, engages with the teeth cut in the upper edge of the ring D. During this movement about the core F, the driving wheel E is forced to turn about its axis, since it engages in a toothed ring G integral with the core F. As the pinion E runs on ring G it pushes ring D in the same direction as the movement of hood B and due to the difference in the number of teeth on ring D compared with the number of teeth on ring G the ring D will move faster than hood B and for every revolution of hood B the ring D will make one revolution and a fraction, so that the reference Figures (l to 4) are visible at each turn on the ring D through the aperture C in the hood.

As it is possible, after removal of the hood B and of the driving wheel E, to regulate the ring D and to cause it to turn freely about the core F, the advantage is aorded that the figures may be marked before the complete assembly of the shell.

Another advantage resi-des in the central disposition of the screw H, which serves to x the hood B and to obtain between the cone K in the core F on the one hand and that provided on the core J on the other hand, the friction indispensable for rapidly setting the hood by blocking of the nut L.

Moreover, as the clockwork movement M is wound with the aid of the hood B and of the core J enclosed therein, these members are protected against being brought out of adjustment, which might possibly be caused by the great speed of rotation of the shell in the air, owing to the fact that at the moment when the shell is fired the ring N and its cone O are violently pressed against the copper washer P. This washer P thus enters the teeth Q of a ring R and thus protects the clockwork movement M from being brought out of adjustment with the aid of pins S situated in the movable part of the latter. In order to prevent the ring N from becoming released, the ball T freed by centrifugal force slides towards the outer edge and thus prevents the ring N from moving.

Finally, it is self-evident and readily seen from the foregoing. that the invention is in no way limited to the form of construction hereinbefore referred to, nor to that of its various parts, but variations and constructional modications may be resorted to and parts may be used without others. y

What I claim and desire to secure by Letters Patent of the United States is:

1. Time fuse mechanism for projectiles oomprising a shell jacket, a hood mounted at the nose of the jacket and rotatable about the axis of the shell, said hood having an aperture and being marked with graduations, said jacket being provided with a chamber to house a clockwork mechanism, a crown mounted on said jacket and `within said hood and rotatable about the axis of the shell, said crown being marked with graduations which are visible through the aperture in the hood, and differential gear mechanism providing a drive between the hood and the crown and adapted to rotate said crown at a speed different from that of said hood when the latter is rotated.

2. Time fuse mechanism for projectiles comprising a shell jacket, a hood mounted at the nose of the jacket and rotatable about the axis of the shell, said hood having an aperture and being marked with graduations, said jacket being provided with a chamber to house a clockwork mechanism, a crown mounted on said jacket and within said hood and rotatable about the axis of the shell, said crown being marked with graduations which are visible through the aperture in the hood, differential gear mechanism providing a drive between the hood and the crown and adapted to rotate said crown at a speed different from that of said hood when the latter is rotated, a cone integral with the hood, said jacket having a core integral therewith and a conical recess in said core, into which recess said cone extends, and a screw extending axially through the cone and the conical recess, said screw being adapted to lock the hood relatively to the crown.

3. Time fuse mechanism for projectiles comprising a shell jacket, a hood mounted at the nose of the jacket and rotatable about the axis of the shell, said hood having an aperture and being marked with graduations, said jacket being provided with a chamber to house a clockwork mechanism, a crown mounted on said jacket and within said hood and rotatable about the axis of the shell, said crown being marked with graduations which are visible through the aperture in the hood, differential gear mechanism providing a drive between the hood and the crown and adapted to rotate said crown at a speed diierent from that of said hood when the latter is rotated, a cone integral with the hood, said jacket having a core integral therewith and a conical recess in said core, into which recess said cone extends, a screw extending axially through the cone and the conical recess, said screw being adapted to lock the hood relatively to the crown, a ring capable of bodily movement in the direction of the axis of the shell, a washer connected with the clockwork mechanism and arranged concentrically with the ring, and a toothed member integral with the shell jacket, the said ring being adapted due to its inertia to force the Washer into engagement with the toothed member on the ring of the she-ll whereby the clockwork mechanism is. locked, means actuated by centrifugal force being provided to maintain the ring in the position in which it ensures the locking of the clockwork mechanism.

PAUL GIRARD.

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