US3045598A - Ball set back detent - Google Patents

Description

July 24, 1962 c. F. BROWN ETAL 3,045,598

BALL SET BACK DETENT 2 Sheets-Sheet 2 Filed Jan. 12

FIG.4.

FIG.5.

INVENTOR5. C. F. BROWN R. M.JAOKSON R. T. CAMPBELL A RNEYS,

United States Patent Ofifice 3,045,598 Patented July 24, 1962 BALL SET BACK DETENT Calvin F. Brown, Paradise, and Roderick M. Jackson and Richard T. Campbell, Lancaster, Pa., assignors, by mesne assignments, to the United States of America as represented by the Secretary of the Navy Filed Jan. 12, 1959, Ser. No. 786,438 6 Claims. (Cl. 10280) This invention relates to a fuze construction for a rotative missile, and more particularly to the arming of the missile.

In Ordnance missiles having explosive charges, it is desirable that the missile be maintained in a safe or unarmed condition until it has been discharged or fired and is at a safe distance. Ordinarily a safety device designed to be actuated by setback or by centrifugal force is incorporated in the missile. Sometimes a setback mechanism may be prematurely actuated by dropping and a centrifugal force operated device by rolling so that an otherwise safe missile is armed when it should not be. This is undesirable.

The object of the present invention is to provide a new and improved safety device for a fuze which needs both a setback force and a centrifugal force to render the missile capable of exploding.

A further object of the present invention is to provide a rotor mounted so as to be subject to setback forces and also subject to the centrifugal force of the spinning missile and to provide moving parts cooperating with the rotor so that it will assume an armed position only after being subjected to set back force and centrifugal force in turn.

It is a still further object of the invention to provide an arming device which will operate on being subjected to a setback force and subsequently to a centrifugal force with a limiting factor that delays the action of the centrifugal [force until the acceleration is zero.

It is a still further object of the invention to provide a fuze having a safety arming rotor which is prevented from rotating by a ball, which ball is moved through setback force to a new or second position and is held in said new position during acceleration of the missile after which centrifugal force will cause the ball to again move to a third position which will permit rotation of the rotor to an armed position.

Other objects and many of the attendant advantages of this invent-ion will be readily appreciated as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

FIG. 1 is a vertical section showing the essential parts of the invention in safety position;

FIG. 2 is a view similar to FIG. 1 showing the movement of the pants due to setback force;

FIG. 3 is a view similar to FIGS. 1 and 2 showing the parts at the instant before arming;

FIG. 4 is a top plan view of the invention with the essential parts in safety position; and

FIG. 5 is a similar view showing the parts in armed position.

Referring particularly to the drawings, certain parts necessary to illustrate the invention are shown and designated by like numerals throughout the several views. Other parts closely associated with the parts shown are omitted as they form no part of the invention.

The bottom plate 8 of a switch housing 9 is formed with an oif center hole having a top [referring to the posi tion shown in the drawings] section 10 slightly larger in diameter than a lower or reduced section 12. The lower part of the wall of the reduced section 12 is flared as at 14 to accommodate the end of the cup as will be hereinafter described.

A ball retaining cup 16 fits the lower section 12 and is for-med with an annular flange 18 adapted to engage the bottom of the top section 10. A ball 20 is held in the cup 16 by slightly crimping the lower end as at 22 [FIG. 1] with the ball projecting below the plate 8. A friction titted cap 24 [shown in FIG. 1 only] closes the hole and prevents axial movement of the cup in the hole.

Separated from the bottom plate 8 by a diaphragm 26 is a rotor housing 28 formed with an oif center cylindrical well 3%} in which a rotor 32 is located. The diaphragm 26 is formed with an arcuate shaped hole 27 which provides clearance between the plate 8 and the rotor carried ball permitting the rotor to turn freely through the of are necessary for arming. A tapered hole 34 depends from the well 30, said hole being in line with the hole formed in the bottom plate of the switch housing.

The rotor 32 has a diametric groove 36 housing a moveable strip 38. The rotor 32 has a notch 40 cut into the circumference to reduce the weight at that point. At a second point approximately 90 from the notch the rotor is bored and the hole filled with lead as shown at 41. This provides an unbalanced rotor which when subjected to centrifugal force will be sure to rotate through a predetel-mined arc. A groove 42 in the circumference limits the rotary movement of the rotor by either shoulder 44 or 46 engaging the pin 48. When the pin 48 is in engagement with the shoulder 44, the rotor is in a safety position and when in engagement with the shoulder 46 the rotor is in an armed position. The rotor is also formed with two holes 50 and 52 substantially in a diametric line and opposite each other. The hole 50 which is adjacent the notch 44} contains an explosive 51 which is positioned by rotary movement of the rotor to form a continuous passage through which the charge is ignited. The hole 52 is lined up with the hole in the bottom plate 8 when the rotor is in safety position and held aligned by the ball 20, FIG. 1. The thickness of the rotor and the diaphragm together is only slightly greater than the diameter of the ball so that the ball may be completely housed in the rotor and diaphragm to permit free movement of the rotor.

The rotor housing in addition to the well 30 is formed with a radial slot 54 the sides of which are parallel and serve as guides for a slide 56 supporting a pin 58. A coil spring 60 holds the pin 58 normally in engagement with the rotor and prevents the rotor from moving from the safety position until the pin is withdrawn. The spring is supported by a rod 62 which in turn is carried by the crossbar 64 mounted in the slot 54.

Let it be assumed, by way of example, that the fuze is assembled in the safety position with the hole in the bottom plate aligned with the hole 52 of the rotor and the ball 20 firmly held by the retaining cup 16 and extending into the hole 52. When the missile is fired, the setback force breaks the ball loose from the retaining cup forcing the ends of the cup into the flared portion 14 of the hole. The ball is thrown into the tapered hole 34 when it is subjected to the acceleration of the missile. It is held in the tapered hole until the acceleration value is zero which occurs when the missile is about eight feet from the gun and then the centrifugal force of the spinning missile urges the ball 20 into close engagement with the tapered wall of the hole 34, which directs it into the hole 52 of the rotor. The centrifugal force has moved the slide on the rod 62 compressing the spring 60 and removing the pin 58 from engagement with the rotor. With the moving of the ball 20 completely into the hole 52 the rotor will turn through approximately 90 moving the hole 50 into armed position, the turning of the rotor being limited by engagement of the shoulder 46 with the pin 48 and locked in position by the strip 38 engaging the notch 62. The rotor is now locked in armed position so that the missile may explode at the end of its flight. The lead 41 on one side and the notch 40 on the other insure the turning of the rotor when the missile spins.

Obviously many modifications and variations of the present invention are possible'in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed as new and desired to be secured by Letters Patent of the United States is:

1. An arming delay mechanism for a spin type projectile of the type fired from a gun comprising a switch housing having a bottom plate, a disc shaped body attached to said plate and formed with an eccentric circular well and a radial slot extending into said well, an arming rotor formed with a transverse circular opening and, carried in said well for limited angular movement, means carried within the radial slot and actuated by spin force set up by firing the projectile normally holding the rotor in a safe position, means carried by the bottom plate and actuated by setback force, said disc being formed with a tapered hole partially receiving the means actuated by the setback force to hold the rotor in said safe position after the arming rotor has been released by the spin actuated means until zero linear acceleration is reached, whereby centrifugal force generated by spin of the projectile will move the setback actuated means from the tapered hole to a position permitting partial rotation of the rotor, and means for stopping the rotor in an armed position.

2. An arming delay mechanism according to claim 1 including a rupturable cup carried by the switch housing plate for holding the means actuated by setback force prior to the firing of the projectile.

3. An arming delay mechanism according to claim 2 wherein the means actuated by the setback force is a ball.

4. An arming delay mechanism according to claim 3 including a diaphragm carried between the rupturable cup and the eccentric circular well carried rotor formed with a arc cutout portion, the thickness of said diaphragm and said rotor being slightly greater than the diameter of the ball to permit movement of the rotor with the ball extending through the 90 arc cutout portion of said diaphragm, the diaphragm being so located as to position the arc to permit 90 movement of the rotor from safe to armed position.

5. An arming delay mechanism according to claim 1 wherein the body has a notch communicating with the eccentric circular well, formed therein and a movable strip member slidea bly mounted in a diametric groove located in the face of the rotor carried by said eccentric circular well, said strip member being movable under centrifugal force to engage said notch to lock the rotor in armed position.

6. An arming delay mechanism according to claim 1 and including a charge of explosive carried in a transverse hole in the rotor and positioned to present a continuous passage thru which the charge is ignited when the rotor is moved to armed position.

References Cited in the file of this patent UNITED STATES PATENTS

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