US2420324A - Mechanical time fuse - Google Patents

Description

May 13, 1947. J; E. MIDDLEMISS 2 MECHANICAL TIME F SE Filed Dec. 15, 1959 Fig 1- Fig.5.

uuuuuu [4 lnvET-Lt c11 JusaphJi- Mini [119.1111 55 Patenteol May 13, 1947 NED ST ll EEKZHANICAL TIME FUSE Joseph E. Middlemiss, Philadelphia, Pa, assignor to United States of America, as represented by the Secretary of War amended April 30, 1928; 370 O. G. 757) The invention described herein may be manufactured and used by or for the Government for governmental purposes, without the payment to me of any royalty thereon.

ally employed in such trains as is well understood in the art.

As shown in Figs. 1 and 2 the supporting membar it is formed with two similar parallel chordal This invention relates to a centriiugally op- 5 grooves l2 having rectangular side and bottom erated rack device for driving a pinion suitably defining walls. The grooves i2 are disposed equiconnected in driving relation with the clockdistant on either side of the axis of spindle l I work train or" a mechanical time fuse for projecand the portion (3 of plate It lying between the tiles. grooves I2 is formed with the guideways i l for The rack device of this invention comprises a apurpose made clear hereinafter. pair of opposed radial movable racks which Spindle ll is either milled to provide an infunction in the same general manner as the racks tegral pinion E5 or a separate pinion is suitably in U. S. Patent No. 1,970,207 and British Patent secured to the spindle as may be desired and two No. 265,583. oppositely acting similar rack members It are It is an object of the invention to so arrange disposed with one in either groove I2 to act upon the rack device as to facilitate the testing of the the pinion l5 and arbor ll for driving the confuse. nested clockwork train not shown.

It is a further object or the invention to so Each rack member it comprises a rack ll of arrange the rack device that it may be used fol rectangular cross-section and of substantially the testing the fuse thereafter be reengaged with depth of the guideways it fitted in the grooves its cooperating pinion to re-run the clockwork l2 and engaging the pinion It in driving relation. train without necessity of revers ng the clockwork The racks ll each have weights l8 suitably atmechanism, whereby the time consumed in testtached thereto so proportioned that the center ing will be materially reduced and the accuracy of gravityrof the rack member it will fall within of adjustment materially increased due to the the weight l8 as secured to the rack ll. In acelimination of blllrlng the escapement gear teeth Cordance With t e invention e W ts 153 are of the clockwork which invariably accompanies so shaped externally as to fit the grooves l2 in running the clockwork train in reverse direction. sliding relation and serve to guide the movement The specific nature of the invention as well of the racks in cooperation with the guideways It. as other objects and advantages thereof will so n per ti n the racks is are inserted in the clearly appear from a description of a preferred gTOOVBS l3 With the a teeth a j t e embodiment as shown in the accompanying drawei hts engaging the pini l5 a t e ts ings in whi h; 18 disposed on a circle concentric with the axis Fig. 1 is a plan view of a fragmentary portion of pinion It. When a projectile armed with a of a fuse with the present invention embodied fuse embodying the racks it is fired the rotation showing the racks near the outer extremity of Of the projectile will cause the centrifugal force their outward movement; developed to act upon the Weighted racks and Fig. 2 is a sectional view taken on the line 2-2 m e them outwardly n the grooves 1 Outof Fig, 1; ward movement of the opposed racks will exert Fig. 3 is a bottom plan View of one of the racks is a dr v t rqu on t s e l I t h pini n of this invention; and I5 and drive the clockwork train connected with 4 is a view in side elevation of the rack the Spindle ii. y this a e t t e in t al Shown in Fig 3; starting torque is high as compared with the Referring now to the draviin s by characters Sector racks used in l l heretofqle as of reference and more particularly to Fig. 1 there the tolfque increases Wlth mcreas? 1n Instance is shown a supporting member it which is genof Welghts from the 3X15 of splndle H the orally a circular plate disk member. Several increased torque with outward displacement of disks such as member is are superimposed upon the racks will compensate for the retardatlon of other to form a support for the complete the projectile in rotation as it passes through its clockwork train but as they form no part of the t j y present invention they are omitted from the In t stns t f for accuracy at the drawings for the e of clarity. clusion of manufacture the fuse is pun about its ihe merr M: is axially bored to provide a axis by means of a machine for such p pose and hearing for the spin lie or arbor El of a clockthe weighted racks are forced outward by cenwork train governed by the escapement genertrifugal force to drive the clockwork train. During this test operation the fuse escapement may be adjusted if necessary and at the conclusion of the operation the weighted racks are simply withdrawn from the grooves l2 and reinserted with the teeth thereof adjacent the weighted en'ds engaging the pinion l5 as above described. In this manner the necessity of running the clockwork train in reverse to reposition the racks for subsequent actuation by centrifugal force is obviated which saves the time of running clockwork train in reverse and the Wear and burring of the teeth of the delicate escapement device. Hence a substantial saving of time is efiected in testing each fuse which is a critical item in quantity production and the accuracy of adjustment after being made will not be disturbed by the introduction of factors not compensated for, such as a Worn or burred escapement, resulting from the reverse driving of the clockwise train after adjustment is made.

Having now particularly described what is at present a preferred embodiment of the invention I claim and desire to secure by U. S. Letters Patent:

In a fuse in combination, a cylindrical supporting member formed with two parallel chordal grooves having rectangular side and bottom defining Walls, said grooves being disposed one on either side of the axis of the member equi-distantly and being formed to provide guideways in the upper portions of their adjacent defining walls, a spindle mounted axially of the supporting member adapted to drive a clock- Work train, a pinion secured to the spindle, a rack of generally rectangular cross-section having teeth adapted to engage the pinion in driving relation mounted in each of said grooves with its teeth disposed in the guideway thereof, said racks being slidable throughout the length of the grooves and provided at their outer end portions with depending weights engaging the grooves in guiding relation.

JOSEPH E. MIDDLEMISS.

REFERENCES crisis!) The following references are of record in the file of this patent:

UNITED STATES PATENTS Number 7 Name Date 1,970,207 Varand Aug. 14, 1934 FOREIGN PATENTS Number Country Date 265,588 Great Britain May 2, 1928

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