US2971367A - Fuze test device - Google Patents

Description

Feb. 14, 196 M. E. SHINDLEDECKER 2,971,357

FUZE TEST DEVICE 3 Sheets-Sheet 2 Filed Jan. 30, 1958 INVENTOR. M. E. SHINDLEDECKER ATTYS.

Feb. 14, 1961 Filed Jan. 30, 1958 M. E. SHINDLEDECKER FUZE TEST DEVICE 3 Sheets-Sheet 3 M. E. SHINDLEDECKER iy z w ATTYS.

United ates FUZE TEST DEVICE Maurice E. Shindledecker, Laurel, Md., assignor to the United States of America as represented by the Secretary of the Navy The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without the payment of any royalties thereon or therefor.

This invention relates to a test device for an electric fuze for use with a projectile and more particularly to a device for simulating the setback force applied to a fuze as the projectile is fired from a gun, in which means are provided for measuring the interval of time between the application of the simulated setback force to the fuze and the instant of operation ofthe fuze in time delayed relation with respect to the application of such force.

Heretofore the methods previously employed for actuating the fuze switch plunger of the electric time delay fuze to set the time delay mechanism into operation were of the type known as a drop test in which a mass was dropped from a predetermined height in a manner to impinge uponthe fuze to effect actuation of the switch plunger thereof or to actually fire the fuze from a gun. Still another method heretofore employed was to use a hammer for obtaining the setback force necessary to set the fuze into operation. Such methods were inaccurate and costly, the inaccuracy being due principally to the lack of proper coordination between the application of the setback force and the closure of a timing circuit concurrently therewith.

The device of the instant invention possesses all of the advantages of the prior art devices and methods and none of the foregoing disadvantages. i

In accordance with the present invention the fuze is set into operation by a rammer or ram comprising a spring actuated plunger releasable from a cockedposition by a solenoid latch arrangement thereby applying the necessary simulated setback force to the fuze and simultaneously therewith completing a control circuit to an electric counting mechanism, the counting mechanism b eing brought to rest when the fuze fires, as will more clearly appear as the description proceeds. t

' One of the objects of the present invention is the provision of a new and improved ram for actuating an electric fuze and completing a control circuit simultaneously therewith. r i Another object is a test device for an electric fuze havtag new and improved means for suddenly imparting a simulated setback force thereto and closing a control circuit simultaneously with the application of the force.

Still another object is the provision of a time testing [mechanism to which the fuze to be tested is clamped and which provides a new and improved ram for setting the fuz e into operation and simultaneously therewith starting 3 an electronic counter for measuring the time interval before the fuzeperforms a firing operation.

Still other objects, advantages and improvement will be apparent from the following description taken into connection with the accompanying drawings of which: W 1 Fig.1is a plan View of the test device accordingito a preferred form thereof on which is shown the fuse to be tested;

"ice

Fig. 2 is a view in elevation partially broken away and partially in section of the device of Fig. 1; I

Fig. 3 is an end view of the fuze testing device of Fig. 2;

Fig. 4 is a view of the device taken along line 44 of Fig. 1;

Fig. 5 is a view taken along the line 5-5 of Fig. 4;

Fig. 6 is an end view of the fuze clamping mechanism and a fuze clamped thereby; and

Fig. 7 is a schematic diagram of an electrical circuit suitable for use with the present invention.

Referring now to the drawings on which like numerals of reference are employed to designate like or similar parts throughout the several views and more particularly to Fig. 1 thereof, there is shown thereon in plan view, a testing device according to a preferred form of the invention and indicated generally by the numeral 10. The device comprises a base 11 to which is secured as by the bolts 12 a ram mechanism 13 comprising a block member 14 secured to the base by the bolts 12.

The block member 14 is provided with three axially aligned bores 15, 16 and 17 of increasing diameter in the order named, Fig. 4. Within the bores 15, 16 and 17 is disposed for sliding movement a plunger 18 having a shoulder 19 formed thereon adapted to be brought into engagement with shoulder 21 as the ram is fired. A rod 22 is fitted within bore 23 within plunger 18 and secured therein in any suitable manner as by the pin 24 illustrated. A plug 25 is threaded into block member 14 as at 26 and provided with a bore 27 within which rod 22 is slide ably disposed in axial alignment with bores 15, 16 and 17. A helical spring 28 disposed about rod 22 and having one end thereof in engagement with an end surface of plunger 18 and the other end in engagement with an end surface of plug 25 is employed to move the rod 22 from the cocked position of Fig. 4 to the final or rest position shown on Fig. 2 with shoulder 19 thereof engaging shoulder 21 of the block member 14. The outer end surface of plug 25 is formed at an inclined angle with respect to the axis of rod 22 thereby to form a cam surface 29 for coaction with a complementary cam surface 31 formed on cam member 32, the cam member 32 being rotatable in either direction selectively about rod 22.. The end portion of rod 22 is provided with a-stop member 33 secured thereto in any suitable manner as by the pin 34 illustrated. There is also aflixed to cam member 32 a lever or handle 35, Fig. 1, whereby the cam member 32 may be moved from the operated or cocked position of Fig. 4 selectively at will to the released position of Fig. 1 after a cocking operation of the plunger has been achieved. There is also preferably provided a guide member 36, Fig. 2, having a cam surface 37 thereon for moving the cam member axially along rod 22 as the lever 35 is restored after a cocking operation to the position shown on Fig. 2 such that cam surface 31 thereof engages cam surface 29 of plug 25 throughout the entire surface thereof. The guide member 36 is secured to block member 14 in any convenient maner as by the screws 38 illustrated.

The base 11 is provided with an upstanding portion 39 tapped to receive a screw 41 having a round head 42 thereon disposed within a recess 43 formed within the block member 14 and retained therein rotatably by the annular member 44 threaded within the block member 14. The screw .41 thus provides means for adjusting the block member 14 in a manner to vary the stroke of plunger 18 when .the'screw is rotated by a wrench or other. tool fitted to the machined end 45 thereof. The screw ismaintained in anadjusted position by nut 46 threaded thereon when the nut is tightened against the upstanding portion 39 of the base 11.

Secured to the block member 14 as by the screws 47 is a support 48 disposed generally transverse to the direction'of movement of plunger IS-and carrying "at the outer portion thereof a solenoid 49 to whichthe support is secured as by the screws 51, Fig. 5. A magnetic plunger 52 is slideably disposed within the solenoid magnet substantially as illustrated and provided with a bore 53 in the outwardly extending portion thereof within which is slideably disposed a rod-like latch member 54 having an elongated slot 55 formed therein and encircling a pin 56 secured to plunger 52. An arrangement is thus provided in which the plunger 52 applies a sudden axial force to the rod-like member 54 when pin 56 has moved to the left, as viewed on Fig. 5, sufficiently to engage the left end of the slot 55. The latch member 54 is disposed within a bore 57 formed within block member 14 and the end portion of the latch is slideably disposed within bore 58 in alignment with bore 57 and communicating with bore 16. The latch member is provided with a helical spring 59 having one end thereof in engagement with a threaded retaining member 61 and the other end in forcible engagement with washer 62 abutting stop pin 63. An arrangement is thus provided in which the outwardly projecting end of the latch member 54 is urged by spring 59 into engagement with cylindrical surface 64 formed on plunger 18 in such manner that shoulder 19 of the plunger is latched in a cocked position by the end portion of latch member 54 until the latch member is suddenly retracted by operation of solenoid 49.

Secured to base 11 as by bolts 65 is an upstanding bracket 66 having an aperture therein for receiving fuze 67 to be tested. A complementary clamp member 68 having a pair of downwardly protruding legs 69 interconnected by an arcuate surface 71 is employed to clamp the fuze 67 tightly against bracket 66, the fuze 67 being provided with an annular raised portion 72 against which the clamping pressure is applied. The lower end of each of the legs 69 is provided with a downwardly projecting cylindrical portion 73, Fig. 2, disposed within a pair of elongated slots 74 formed within the base 11 in such manner as to provide a limited degree of movement in 'a direction parallel to the axis of the fuze and to facilitate the removal of the fuze after test by disengagement of the clamp member 68 from the base 11. A pair of adjusting screws 75 are provided within the base 11 for adapting the clamp to different sizes of fuzes 67 to be tested and to provide a uniform clamping pressure about the annular raised portion 72 when the fuze is clamped therein. The upper portion of bracket, 66 is provided with a slot 76'within which is disposed for pivotal movement an eye screw 77 and secured for pivotal movement in respect thereto as by the pin 78. The upper end of clamp member 68 is also provided with a slotted portion 79 of sufficient width to allow free pivotal movement of the eye screw 77 therein. The eye screw is threaded as at 81 for threaded engagement with a knurled knob 82 whereby the fuze to be tested is clamped by the clamp member 68 when the eye bolt is in the position shown on Fig. 2 and the knurled knob 82 is. tightly screwed into a clamping position in engagement with the clamp member 68. The fuze 67 to be tested is of the type known in the art as .a time delayfuze in which the time delay mechanism is set to operation by a force suddenly applied to. the plunger 83 thereof. When the period of time as originally set into thefuze has expired, a switch 84 isclosed thereby-completing a circuit across a pair of terminals 85 carried by the fuze. q j

This simulated setback force is applied to plunger 83 ,by a rod'86 threadedly securedthereto at one end thereof and at the other end threadedlysecured to plunger 18.

Plunger 18, it will be -noted,,is provided with a cam surface 87 cooperating with cam follower 88 secured to a movable member 89 of microswitch 90.. .Theswitch 99 is disposed within a recess 91-formedwithin block "-What is claimed as new and desired to be secured by member 11 and provided with a plurality ofterminals 1 92, 93 and 94 and secured to thesblock member 14in anyjsuitable manner as by the screws 95. I

93'and 9.4..of micro- As shown on Fig. 7 the terminals switch are connected to the start'circuit or an electronic counter indicated generally by the numeral 96 in such manner that the electronic counter is set into operation when terminals 93 and 94 are closed by the switch in response to movement of plunger 18 from the cocked position as the solenoid 49 is operated. When the fuze 67 operates at the end of the delay period the closure of switch 84 thereof causes the electronic counter to be brought to rest whereby the actual elapsed time between the application of the simulated setback force to fuze 67 and the operation of the fuze may be made manifest. When the simulated setback force has been applied to fuze 67 by plunger 18, the operating circuit to the solenoid 49 is interrupted thereby deenergizing the solenoid plunger 52 causing the plunger to be moved by spring 97 to the position shown on Fig. 5 and the latch member 54 to be released and brought into engagement with the plunger 18.

' The operation of the device will best be understood by consideration of a specific example. Let it be assumed, for purpose of description that a time delay fuze such as the fuze 67 is clamped into the device andsecured to the ram by rod 86 and that the plunger 18 has been cocked by reciprocal movement of lever 35 from the position shown on Fig. 2. As the lever 35 is moved to a diametrically opposite position from the position shown on Fig. 2, the cam member 32 secured thereto is rotated to the position shown on Fig; 4 whereby cocking the ram which is now locked in the cocked position by latch member 54- as shown in Fig. 5. The handle or lever 35 is now restored to the initial position of Fig. 2 and the cam member 32 connected thereto is moved axially 'along rod 22 by-the cam surface 327 of guide member 36 to the position of Fig. 2 such that the outer flat surface thereof is disengaged from stop member 33. With the plunger 13 in a cocked position the microswitch is .in the position shown in solid outline on Fig. 7 with terminal 94 thereof in engagement with terminal 92. As an operating current is applied to the solenoid 49, the solenoid is energized thereby causing the plunger 52 to be quickly moved inwardly, and as pin 56 connected to the plunger engages the inner end surface of slot 55 the rodlike latch member 54 is suddenly moved away from shoulder 19 of plunger 18. When this occurs the plunger 18 is moved quickly in a direction of fuze 67 thereby setting the time release mechanism of the fuze into operation and concurrently therewith actuating microswitch 90 to a position interconnecting terminals 94 and 93 thereof thereby setting the electronic counter 96 into operation. As switch 84 of fuze 67 is closed at the end eye screw 77 upwardly sufficiently for the knob to be disengaged from clamp member 68 and the clamp member to be withdrawn from base 11. The fuze 67 may now be rotated sufficiently to be disengaged from rod 86 or the a rod 86 to be disengaged from plunger 18, as the case may be. I

While the invention has been described with particularity with reference to a preferred example thereof which gives satisfactory results, it is not so limited, as itwill be apaprent to those skilled in the art to which the invention pertains, after understanding the invention, that various changes and modifications may be made without departing from the spirit and scope of the invention and it is intended therefore, in the appended claims, to cover all such changes and modifications.

Letters Patent of the United States is:

1. A test device for a projectile fuze comprising means including a bifurcated plate for clamping the fu ze to said I device, means including a rod normally in contact with the fuze for applying a sudden force to the fuze simulating the setback force applied thereto as the projectile is fired from a gun, said device comprising a frame, a support mounted within said frame and adjustable therein, a plunger secured to said rod in coaxial relation therewith, said plunger being slideably mounted in said support and urged in one direction by a spring, cam means including a pair of mutually opposed cam surfaces for retracting said plunger against the urging of said spring from a released position, a latch pin movably mounted in said support and engageable with said plunger for retaining the plunger in retracted position, a solenoid mounted on said support and having an armature connected to said latch pin by a slot and pin connection, resilient means engaging an end of said plunger for yieldably maintaining the last-named pin in engagement with one end of said slot when the latch pin engages said plunger, said connection permitting the armature to move and exert a sudden pull on the latch pin to release the plunger as the pin forcibly strikes the end of said slot, said plunger having a cam surface, a microswitch carried by the support and having a movable part engageable with the cam surface of said plunger, movement of said plunger from a retracted position to the release position serving to cam said part to a position closing said microswitch, said microswitch having a plurality of electrical terminals for connection to an electronic counter whereby the electronic counter is set into operation as the micro switch is closed, and means on said fuze and electrically connected to the counter for interrupting the operation of the counter as the fuze is fired.

2. A test device according to claim 1 in which the fuze under test is of the type which includes means for closing a firing circuit in time delayed relation with respect to the application of the simulated setback force applied thereto, means within the fuze for actuating said circuit closing means, andmeans for establishing an electrical connection between said circuit closing means and the electronic counter thereby to interrupt the operation of the counter as the switch is closed whereby the time delay of the fuze is made manifest.

3. A fuze testing device comprising means for clamping thereto the fuze to be tested, a spring driven ram slideably moveable selectively from a cocked position to a released position, a rod interconnecting said ram and a fuze to be tested, spring means for quickly moving the ram and rod to said release position, manipulative means having a cam surface thereon for moving the ram and rod to said cocked position, means for latching the ram in said cocked position, a solenoid for actuating the latching means to release said ram thereby to cause the rod to actuate the fuze, a normally open switch, means including a cam surface on said ram for closing said switch as the ram moves from said cocked position to the release position, and electronic counting means operatively connected to said switch and operable as the switch is closed.

4. A testing device according to claim 3 in which the fuze under test comprises a normally open switch adapted to be closed in predetermined time delay relation with respect to the instant of application of force to said fuze by the rod, and means including a plurality of electrical circuit connections for establishing a control circuit from said last named switch to the electronic counting means thereby to interrupt the operation of the counting means as the last named switch is closed.

5. A projectile fuze tester comprising a base member, means secured to said base member for clamping a fuze to be tested, a ram carried by said base member and having a bore therein in alignment with the fuze, a spring actuated ram member slideably disposed within said bore and operatively connected to the fuze for imparting a sudden force thereto as the ram member is actuated from a cocked position to a released position, said force simulating the setback force applied to the fuze as the projectile is fired from a gun, means operable at will for moving the ram member to said cocked position, solenoid actuated means for releasably latching the ram member in said cocked position, and a rigid rod interconnecting the end of said ram member with the fuze whereby said sudden force is applied to the fuze by the rod as the ram member is released from said cocked position by said solenoid means.

6. A fuze tester according to claim 5 in which the means for clamping the fuze to be tested comprises a fixed member and a moveable clamping member, and means operatively connected to said moveable clamping member for adjusting the clamped position thereof in a manner to apply a clamping force uniformly to an upraised circumferential portion of said fuze.

7. A tester according to claim 5 including means settable at will for adjusting the initial and cooked positions of said ram member with respect to the fuze.

8. A tester according to claim 5 in which the solenoid means includes a solenoid plunger having an axial bore within one end portion thereof, a latch member slideably disposed within said bore and having a slot formed 1ongitudinally therein and a pin secured transversely to said solenoid plunger and disposed within said slot for applying a sudden force to the latch member suflicient to operate the latch member quickly as the pin strikes one end of said slot in response to the operation of the solenoid plunger.

9. A tester according to claim 8 including a spring for yieldably urging said plunger to an unoperated position with the pin normally engaging the other end of said slot.

10. A tester according to claim 5 including a cam surface on said ram member, a switch disposed in closely spaced adjacency to said cam surface, and a complementary follower on said switch for closing the switch and engageable by said cam surface as the ram member moves from said cocked position to said reieased position.

References Cited in the file of this patent UNITED STATES PATENTS 1,241,213 Heisler Sept. 25, 1917 1,691,170 Schmidt Nov. 13, 1928 2,037,129 Hilts Apr. 14, 1936 2,689,938 Larson Sept. 21, 1954 2,697,344 McNatt Dec. 21, 1954

Images