US1943706A

US1943706A - Self-retarding mechanical percussion fuse for projectiles

Info

Publication number: US1943706A
Application number: US555442A
Authority: US
Inventors: Varaud Andre
Original assignee: Individual
Current assignee: Individual
Priority date: 1930-08-07
Filing date: 1931-08-06
Publication date: 1934-01-16
Anticipated expiration: 1951-01-16
Also published as: NL29630C; GB371247A; CH148799A; DE556631C; GB377914A; FR720925A

Description

Jan. 16, A VARAUD SELF RETARDING MECHANICAL PERCUSSION FUSE FOR PROJECTILES Filed Aug. 6, 1931 2 Sheets-Sheet l INVENTOR dmfc Vmuw( hw ATTORNEY Jan. 16, 1934. A. VARAUD 1,943,706

SELF RETARDING MECHANICAL PERCUSSION FUSE FOR PROJECTILES BY ma NJM/A his ATTORNEY Patented Jan. 16, i934 SELF-RETARDING DECHANICAL PERCUS- SION FUSE F0 R PROJECTILES Andr Varaud, Geneva, Switzerland Application August 6,

1931,- Serial No. 555,442,-

an-:l in Switzerland August 7, 1930' Y 6 Claims.

The object of the present invention is a selfretarding mechanical percussion fuse, for projectiles, characterized by mechanical means which, at the moment of impact, prevent ignition of the charge by point of the striker at least until the moment when an important part of the momentum of the projectile has been absorbed by the obstacle.

The annexed drawings show, only by way of example, two forms of execution of the object of the invention, applied to a perforating shell of small bore.

Fig. 1 shows the fuse and the shell according to the first form of execution in axial section in a transportable condition.

Fig. 2 is an axial section ofthe shell with its pyrotechnical equipment and shows the position taken up by the organs of the device at the moment of impact.

Fig. 3 is also an axial section of the shell, at the moment of function of the percussion, after the projectile has overcome the resistance of the obstacle or that its momentum is almost entirely absorbed.

Fig. 4 is a cross section made according to the une A-A of Fig. 1,

Fig. 5 is a View in detail in elevation of the striker of the fuse and,

Fig. 6 is an elevation of the organ of command of the percussion.

Fig. '7 is an axial section of the fuse according to the second form of execution with its pyrotechnical equipment and shows the position of the various organs in a transportable condition.

Fig. 8 is also an axial section of the fuse as shown in Fig. 7, but at the moment of impact (beginning of the movement).

Fig. 9 is an axial section of the fuse showing the position of the various organs at the moment of impact (termination of the movement).

Fig. 10 is an axial section of the fuse, at the moment of function of the percussion, after the projectile has overcome the resistance of the obstacle or that its momentum is almost entirely absorbed.

In referring to the drawings, it is seen that the fuse according to the rst form of execution comprises: the bottom plug 1 on which is screwed a body 2 which carries a socket at its front extremity, screwed on to the body and containing the primary detonator. The body 2 is pierced longitudinally by two cylindrical bores, which lie parallel to the axis of the projectile and at an equal distance from this axis. In one of these bores a striker 4, toothed in the manner of a rack (o1. 1oz-39) 4a, can slide freely and in the other a cylinder 5 also toothed in the same manner.

This striker 4 and this cylinder 5 are joined together in their movements by a pinion 6, radially situated between them, which cooperates with their respective teeth.

A Screwed plug 6a maintains this pinion in its place.

The striker 4 acts under the influence of a helicoidal spring 4b which tends to push the latter towards the percussion cap 8.

A centrifugal bolt 9, perforated by a bore 9a in which is engaged a projection 5b of the cylinder 5, assures that this latter is in a transportable condition, that is to say, in the position where the striker 4 is maintained away from the percussion cap 8.

As will be seen in Fig. 1, the spring 4b, which is only partly stretched, pushes the striker 4 in the direction of the percussion cap, but as the teeth 4a are engaged with the pinion 6, this latter tends to turn counter-clockwise, as indicated by the arrow (Fig. 1) and 'tends to cause the cylinder 5 to descend.

But because the centrifugal bolt 9 engages under the cylinder and is further maintained in its active position by the introduction of the projection 5b into the bore 9a, the cylinder cannot effect this descending movement, in such a way that the striker 4 is maintained away from the percussion cap. Y

The function'of the fuse is the following:

At the departure of the charge and underv the action of centrifugal force, the organs of the fuse do not leave the position they occupy in Fig. 1, either during the lineal acceleration or during the ilight.

In fact, during the lineal acceleration, the cylinder 5, which is much heavier than the hollow striker 4, remains appliedby inertia to the centrifugal bolt 9, and during the flight, this bolt is maintained in its active position against the action of the centrifugal force, by the projection 5b of the cylinder 5.

At the moment of impact, the cylinder 5 comes, by inertia, into the position represented in Fig. 2, and by means of its teeth draws the pinion 6 in the clockwise direction; this latter simultaneously communicates its movement to the striker 4, by the intermediary of the

strikers teeth

4a,4 which compresses the spring 4b in causing the striker to retreat from the percussion cap.

When the projectile has overcome the resistance of'the obstacle, thick iron plating, wall, concrete work etc., and that the momentum of 110 the cylinder 5 is absorbed, the spring 4b acts and pushes the striker in the direction of the percussion cap, in causing the pinion 6 to turn counterclockwise.

But as the centrifugal bolt 9 has been freed, by the forward displacement of the cylinder 5, at the moment ofimpact, the centrifugal force brings the bolt 9 into the position represented in Fig. 3 which causes the cylinder 5 to be displaced suiciently backwards by the pinion 6 so that the teeth 4a of the striker escapes the teeth of the pinion 6.

In fact, towards the opposite extremity of the point 4d of the striker, a fla-t cut part 4c is provided (Fig. 5) in order that the last tooth of said striker may suddenly escape the teeth of the pinion 6, and thus cause the percussion spring 4b to stretch and cause the deagration of the percussion cap 8 and at the same time the explosion of the projectile.

The fuse according to the second form of execution also comprises a bottom plug 10 which alone has been represented in Figures 7 to 10. This plug is partly grooved, this grooving comprising two cylindrical bores, which lie parallel to the a-,XiS of the projectile and at an equal distance from the axis. These two bores are closed by a socket 11 screwed in the plug, and containing the primary detonator.

In one of these two bores may slide a striker 12 formed by a short cylinder rendered lighter by a circular neck andY carrying, on the one hand, the point of the striker, and on the other hand, an abutment 13.

In the other bore a cylinder 14 may slide having three notches of which one, 15, relatively short is separated from another, 16, relatively long, by a tooth 17, the third notch 18 taking the form of the centrifugal bolt 19 penetrating into this third notch.

The striker 12 and this cylinder 14 are dependent upon each other in their movement by an oscillating organ 20 in the form of a lever of which one arm is able to penetrate into one or the other of the

notches

15 and 16 and the other arm of which, in the form of a beak, is able to retain the striker 12 away from the percussion cap 21. This oscillating organ 20 turns about a pivot situated in the axis of the fuse and directed according to a diameter of this latter perpendicular to the plane passing through the axis of the two bores.

rIhe striker 12 is under the action of a helicoidal spring 22 which tends to push this latter towards the percussion cap 21. A rod 23 is placed concentrically to this spring and is intended, at a given moment, to be met by the abutment 13 of the striker 12.

In the position represented in Fig. 7 the spring 22 is sufficiently taut to be able to cause the displacement of the striker l2 in the direction of the percussion cap 2 1, but this displacement is rendered impossible due to the fact that, on the one hand, the beak of the oscillating organ 20 stops the striker and that, o n the other hand, this organ cannot turn, given that it penetrates into the notch 15 of the cylinder 14 and comes to bear upon the tooth 17 of this cylinder. The cylinder, on the other hand, cannot be displaced because it is maintained in place by the centrifugal bolt 19.

The function of this second form of execution of the fuse is as follows:

At the departure of the charge, the organs of the fuse do not leave the position which they occupy in Fig. 7, nor during the lineal acceleration, nor during the flight, with the exception of the bolt 19 which, under the influence of the centrifugal force, liberates the cylinder 14.

In fact, during the lineal acceleration the cylinder 14 remains applied by inertia against the bottom of its lodgement. During the flight, the cylinder 14 continues to be maintained in this position by the pressure of the oscillating organ 20 on the tooth 17 caused by the spring 22.

VAt the moment of impact, the cylinder 14, by inertia, takes up the position represented in Fig. 8,. So doing, it causes, by the intermediary of the tooth 17, an oscillation of the organ 20 in the clockwise direction and by reason of this, a compression of the spring 22 by momentarily drawing the striker 12 away from the percussion cap 21. The striker abuts against the rod 23 of which the length must be such that the oscillating organ 20 may be moved out of the path of the tooth 17, but not accomplish a rotation such that the pressure of the striker on the organ 20, no longer acting upon the beak, causes a blockage of the whole device. In fact,k and as shown in Fig. 9, immediately the tooth 17 has passed in front oi the oscillating organ 20, this latter must be caused to turn in the counter-clockwise direction and this under the influence of the pressure of the striker on the beak, and until this movement be in its turn stopped by the engagement of the organ 2G in the notch 16 of the cylinder 1 4.

The length of this notch must be such that it stops the oscillation of the organ 20 in a position where the beak of this latter still retains the striker l2 which will, however, be brought nearer to the percussion cap 21.

When the projectile has overcome the resistance of the obstacle and the momentum of the cylinder 14 is absorbed, the spring 22 pushes the striker in the direction of the percussion cap, forcing the beak of the organ 20 to be moved aside, this organ oscillating to this eifect in the counter-clockwise direction, which is rendered possible by a slight recoil of the cylinder 14.

The striker is liberated and penetrates into the percussion cap and produces the Vdeflagration of same, the organs of the f use then occupy the position represented in Fig. 10.

Instead of being applied to a bottom fuse the device according to the invention may be applied to a head fuse, for all kinds of artillery projectiles or others, aeroplane bombs, etc. without the scope of the invention being limited in any way.

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

1. A self-retarding mechanical percussion fuse for projectiles, comprising a body'pierced by two cylindrical bores which lie parallel to the axis of the fuse and situated at an equal distance from Said axis, a striker freely slidable in one of the bores and a cylindrical mass in the other, the striker and mass being toothed inthe manner of a rack, a pinion connecting these last` namedv the same, and a. centrifugal bolt associated with the icylindrical mass by which the same is retained in position until moved due to its inertia at the moment of impact of the projectile.

3. A self-retarding mechanical percussion fuse for projectiles, comprising a body member, a toothed striker and toothed cylindrical mass freely slidable in separate bores provided for the same in the body, the bores being arranged parallel to the axis of the projectile, a pinion connecting the striker and mass at the toothed portions of the same, a percussion cap, a percussion spring associated with the striker, a centrifugal bolt associated with the cylindrical mass by which the same is retained in position until moved due to its inertia at the moment of impact of the projectile, the mass at such time urging the striker through the medium of the pinion to compress the percussion spring, the striker then being urged against the percussion cap by the expansion of the percussion spring.

4. A self-retarding mechanical percussion fuse for projectiles, comprising a body pierced by two cylindrical bores which lie parallel to the axis of the fuse and situated at an equal distance from this axis, a striker freely slidable in one of the bores and a cylindrical mass in the other, an oscillating lever engaging, on the one hand, a. notch in the cylindrical mass and retaining, on the other hand, by means of a beak, the striker element, a percussion spring associated with the striker to maintain the same in a position against the beak of the lever, and a centrifugal bolt for normally retaining the cylindrical mass irnmovable.

5. A self-retarding mechanical percussion fuse for projectiles, comprising a striker and a cylindrical mass each sliding freely in one of two cylindrical bores, which lie parallel to the axis of the projectile, a percussion spring for urging the striker to a ring position, an oscillating lever engaging in a notch of the mass, and retaining the striker by means of a beak against the action of the spring, a centrifugal bolt for normally retaining the cylindrical mass immovable, the mass having a second notch, which the oscillating lever engages after the same has moved forward due to its inertia at the moment of impact of the projectile, to thereby facilitate the movement of the lever so that its beak leaves the striker.

6. A self-retarding mechanical percussion fuse for projectiles, comprising a striker and a cylindrical mass each sliding freely in one of two cylindrical bores which lie parallel to the axis of the projectile, said cylindrical mass having two notches thereon, a percussion spring for urging the striker to a ring position, an oscillating lever engaging, on the one hand, a notch of the cylindrical mass, and on the other, retaining by means of a beak the striker against the action of the percussion spring, a percussion cap, an abutment limiting the recoil of the striker away from the percussion cap when a forward movement of the cylindrical mass at the moment of impact, causes the said striker to compress the percussion spring by the intermediary of the beak of the oscillating lever, when the oscillating organ disengages with the notch of the cylindrical mass to engage in the second notch of said mass.

ANDR VARAUD.