US3045597A

US3045597A - Centrifugal type safety and arming spring for fuze applications

Info

Publication number: US3045597A
Application number: US57591A
Authority: US
Inventors: Sidney S Linn
Original assignee: Individual
Current assignee: Individual
Priority date: 1960-09-21
Filing date: 1960-09-21
Publication date: 1962-07-24
Anticipated expiration: 1979-07-24

Description

July 24, 1962 s, s, LINN 3,045,597

CENTRIFUGAL TYPE SAFETY AND ARMING SPRING FOR FUZE APPLICATIONS Filed Sept. 21, 1960 INVENTOR. 5- S Linn.

ate

3,045,597 Patented July 24, 1962 tic 3,045,597 CENTRIFUGAL TYPE SAFETY AND ANG SPRING FOR FUZE APPLICATIONS Sidney S. Linn, Garden City, N.Y., assignor to the United States of America as represented by the Secretary of the Army Filed Sept. 21, 1960, Ser. No. 57,591 3 Claims. (Cl. 102-79) This invention relates to a centrifugal type safety and arming spring for fuze applications and more particularly to means for moving an arming rotor in a fuze utilizing centrifugal force applied to a spring, the centrifugal force being generated by spin of the fuze.

This invention comprises an improvement over the centrifugal spring arming device disclosed in copending application by H. G. Wenig and having a common assignee, Serial No. 53,857 filed September 2, 1960, now Patent No. 3,013,496.

In the above identified application there is disclosed a centrifugally actuated arming means for fuzes in spin stabilized projectiles in which centrifugal force acts on a coil or helical spring or the like to expand the Spring and rotate an arming rotor. While such a spring is satisfactory in most instances, it has been found in some applications that a proper ratio of mass to spring constant cannot be attained to provide proper operation. The spring of the present invention has added thereto or formed therein a concentrated mass. This mass can be varied to any degree desired so that a proper mass to spring constant can be obtained for all conditions of operation.

It is an objection of this invention to provide a fuze hav ing a centrifugally operated arming spring of non-uniform mass per unit length.

It is a further object of this invention to provide a fuze having a centrifugally operated arming spring with an additional mass attached thereto.

Another object of the invention is to provide a fuze having a centrifugally operated spring with a concentrated mass near the center thereof.

These and other objects will become more apparent when reference is had to the following detailed description and drawing, in which:

FIGURE 1 is an elevation view partly in section of a fuze according to the present invention,

FIGURE 2 is sectional view taken on the line 22 of FIGURE 1 looking in the direction of the arrows and showing one form of spring, and

FIGURE 3 is a perspective view of a modified form of spring.

Now having reference to the drawing there is shown a fuze having a body 1 provided with a reduced, threaded, rearward extension 2 and base portion 3. The base portion 3 is provided with a through passage 4 having pyrotechnic element 5. The reduced end portion 2 of the body is adapted to be screw connected to the forward end of a spin stabilized projectile so as to be rotatable therewith when in flight. The body 1 is provided with a central bore 6 in which is rigidly mounted the plate 7. The firing pin 8 is carried by the plate 7 in alignment with pyrotechnic element and is movable rearwardly on impact by any conventional means such as crushing of the ogive 9. Rotatably mounted within aligned

recesses

10 and 11 in the base portion 3 and plate 7, respectively, is the spindle 12 of an arming rotor 13. The rotor 13 carries a pyrotechnic element 14 which is normally 90 out of alignment with the firing pin 8 as shown in solid lines in FIGURE 2, but which during flight moves into alignment therewith as shown in dotted lines in FIGURE 2 in a manner to be described. The rotor 13 is provided with a peripheral groove 15 of substantially 90 cira cumferential extent. The housing 1 is provided with inwardly projecting pin 18 which abuts with groove end wall 16 when the rotor is in the unarmed position and end wall 17 when the rotor is in the fully armed position.

In order to move the rotor 13 from unarmed to armed position there is provided a spring 19, as shown in FIG-

URES

1 and 2, having one end connected to the rotor and the other end connected to the base portion 3 of the housing. The spring 19 is formed from a piece of spring wire bent at spaced points to provide a straight central section 20. Applied to the central section 20 by pressing or brazing or formed integral therewith is the weight member 21. When the rotor is in the unarmed position as shown in FIGURE 2 and the fuze is not spinning the spring 19 is in equilibrium; i.e. in an unstressed condition. When the fuze is spinning centrifugal force will act on each segment of the spring as well as on the weight 21 and tend to move the spring radially outward. This applies a torque to the rotor to move it through to the armed position with the

pyrotechnic elements

5, 14 aligned. With the rotor so positioned the firing pin will initiate the element 14 on impact thus detonating the projectile.

Upon firing the groove 15 and pin 18 serve a dual purpose. When fired the projectile and fuze have a very high angular acceleration which would tend to distort the spring 19 immediately to move the rotor to armed position. However, the pin 18 engages the end wall 16 of the groove during angular acceleration and in like manner accelerates the rotor. When the angular acceleration decreases or ceases the centrifugal force acting on the spring is effective to move the rotor to armed position. When the rotor has been armed pin 18 abuts end wall 17 of the groove to insure proper alignment of the pyrotechnic element.

FIGURE 3 illustrates a spring 22 of modified form. In this embodiment the spring is of arcuate shape and carries the weight 23 at approximately the midportion thereof. It can be seen that this modified shape will provide different characteristics for a given spin speed than that of FIGURES 1 and 2.

As pointed out above application Serial No. 53,857, now Patent No. 3,013,496 discloses a similar fuze system utilizing a coil or spiral spring or the like. For most applications such a spring has been found to be satisfactory. However, in certain instances it has been found extremely difficult to obtain the proper ratio of mass to spring constant to provide the desired results. With the arrangement of the present invention this ratio may be changed at will by varying the size of the weight attached to the spring and the instant device is applicable to all fuze applications.

While I have described specific embodiments of my invention herein, it will be recognized that various changes in construction and arrangement may be made without departing from the scope of the invention as defined in the appended claims.

I claim:

1. A fuze for attachment to a spin stabilized projectile comprising, a body having a central bore therein, a pyrotechnic element disposed at the rearward end of said bore, a firing pin at the other end of said bore and in alignment with said pyrotechnic element, a rotor mounted for limited rotation between unarmed and armed positions in said central bore, a pyrotechnic element in said rotor, a wire spring disposed between the rearward end of said central bore and the rearward end of said rotor, said spring having oppositely bent ends, one end being connected to said rotor, and a weight attached to said wire spring intermediate its ends, centrifugal force due to spin of said body causing said weight to move outwardly to distort said wire spring and apply a torque to said References Cited in the file of this patent UNITED STATES PATENTS 792,369 Watson June 13, 1905 4.- Thompson Dec. 22, 1953 Baker Apr. 30, 1957 Piskorski Feb. 25, 1958 Stevenson Sept. 9, 1958 Horowitz Oct. 21, 1958 Taylor Feb. 17, 1959 Koonz Feb. 17, 1959 FOREIGN PATENTS France Feb. 16, 1928