US2173620A

US2173620A - Combination projectile fuse

Info

Publication number: US2173620A
Application number: US169860A
Authority: US
Inventors: Harold M Brayton
Original assignee: Individual
Current assignee: Individual
Priority date: 1937-10-19
Filing date: 1937-10-19
Publication date: 1939-09-19
Anticipated expiration: 1956-09-19

Description

Sept. 1%, 1939. H. M. BRAYTON COMBINATION PROJECTILE FUSE Filed Oct. 19, 1938 2 Sheets-Sheet l Patented Sept. 19, 1939 srra r COMBINATION PROJECTILE FUSE Harold M. Brayton, Westfield, N. J.

Application October 19, 1937, Serial No. 169,860

13 Claims. (Cl. 102-69) The invention relates to a combination prosuch flame has ignited the exciter intended to be jectile fuse of a known general type, and it aims ignited only by the delay train, causing instanto improve upon the prior construction in a numtaneous firing with the fuse set for delayed firing. ber of respects. The shear pin intended for holding the striker In the known structure, a fuse is provided in in safety position until the projectile strikes, if which a nose is rotatably mounted on the fuse made sufficiently weak to shear when striking body, said nose being turnable to one position to soft ground or water, may shear in the barrel of set the fuse for firing instantaneously on impact, the gun or mortar when the propellant charge and to another position to set said fuse for deis fired, causing firing of both primers. If this 1%} layed fire after impact. Two primers are propin shears in the barrel with the fuse set for vided, one for instantaneous firing and the other instantaneous firing, no serious result occurs, for for delayed firing, and two firing pins are provided although the detonator will be fired, the defor said primers respectively, said firing pins betonator-carrying slide will not have moved to lug operable by means of a striker at the front armed position and the projectile charge will not,

extremity of the fuse nose. A shear pin is protherefore, be exploded. However, if the pin shears 15 vided, intended to hold this striker against opwith the fuse set for delayed fire, a V y ri s eration until said striker comes in contact with situation exists, for firing of the detonator is the ground or with some object at the end of prothen delayed by the delay train, giving the detjectile flight, it being intended that said shear pin onator-carrying slide time to move said detonashall then be sheared and that the striker shall tor to armed position, and the entire projectile 20 be driven rearwardly, causing the two firing pins Will be exploded a short distance from the barrel, to simultaneously fire both the instantaneous-fire with severe danger of killing r injurin h n primer and the delayed-fire primer, only the one or mortar crew. or the other being intended to fire the detonator, Similar occurrences may a place if a firing 5 according to the setting of the fuse. The dep is defective, breaks When the p p t 315- tonator is carried by a slide in the fuse body, said charge is fired, and strikes one of the p sslide being operative to move said detonator from y inVention as a med to o ercome all of the a normal safety position to an armed position. A above objections by simple, inexpensive and. efspring-ejected bolt is 1ldab1e in id body 130 ficient improvements, and has attained this end.

hold the aforesaid slide in safety position until Figure 1 0f t e p y g drawings is a 30 the projectile has left the barrel, said bolt being front elevation of a fuse embodying my improvein turn held by a pin which is releasable by set- Inents.

back when the propelling charge is fired. Figures 2 and 3 are sectional views on lines Experimentation, tests and experience with the and f respectivelyfuse above explained, show that certain imper- Figure 4 is a view similar to Fig- 2 t S o 35 fections exist and that projectiles equipped with the fuse nose Set delayed firing W ereas in said fuse subject the gun or mortar crew to ex- Fig. 2 said nose is set for instantaneous firing.

treme danger, as enumerated below. The fuse body is denoted at 5, the rear end of The fuse will not function when striking a Sa d body being provided With S table means 0 comparatively fiat surface of rock, concrete, steel Such a the threaded neck 5 Cohheatihg i or the like, as the striker is flush with the nose With a p j The front end of the y 5 tip and cannot be driven in. is provided with a cylindrical recess l coaxial with Firing of the instantaneous-fire primer has said dy, said recess retatably r eiving the cyoften resulted, due to flame leakage, in explosion lindrical neck 3 0f the fuse 11086 9, aid nose beof the projectile charge instantaneously upon img held in place by p s the like to u t y 45 pact, even though the fuse be set for delayed fire, secured to the body 5 and havin their inner ends The means provided for holding the nose when re eive in a p ripheral ro ve H in the neck 8. turned to its instantaneous-fire setting or to its The front end of the nose 9 is formed with a cylindelayed-fire setting, has not functioned as indrical recess l2 which slidably receives the rear 9 tended. portion of a striker l3, the front portion M of The bolt-holding pin, releasable by set-back, which projects forwardly from said nose to insure has not always released as intended, particularly that the striker shall be rearwardly driven even when using low propellant charges. when striking a hard comparatively fiat surface of The delayed-fire train has frequently been byconcrete, rock or the like, which was not true of passed by flame from the delayed-fire primer and the old structure above referred to. A shear pin I5 passes through the front end portion of the nose 9 and through the striker I3, and due to nove] provision hereinafter described for positively holding said striker against any premature rearward movement, said shear pin may be, with safety, much weaker than the corresponding pin of the old structure, insuring that the striker I3 shall be driven rearwardly even when striking soft earth or water. The ends I6 of the pin I5 are preferably bent laterally into a circumferential groove I? in the front portion of the nose 9, holding the pin against loss and making it possible at a glance to see Whether said pin has been installed.

The usual detonator [8 for the booster charge I9 carried by the fuse body 5, is mounted in a slide of conventional form, said slide being mounted in a bore 2! of the body 5 for movement from the unarmed or safety position shown in the drawings, to an armed position, under the infiuence of a coiled spring 22. The cap-like plug 23 which this spring abuts, is preferably secured in the body 5 by a crimped-in portion 24 of said body.

A bolt 25 slidably mounted in a transverse bore 26 through the body 5, normally holds the slide 23 in safety position, a coiled spring 2'! being provided for ejecting said bolt 25 after the projectile has left the weapon, to permit movement of said slide 20 to armed position, in which position the detonator I8 is in position to explode the booster charge I9. The bolt 25 is normally held against movement under influence of the spring 21, by

. means of a set-back pin 28 which is slidable in a short longitudinal bore 29 in the rear portion of the body 5. This pin 28 is held in its forward operative position by a coiled spring 30 but upon set-back said pin releases the bolt 25 and the latter is ejected from the fuse by the spring 21, releasing the slide 20 for movement to armed position. By making use of the spring 30 for holding the pin 28 in its operative position, this pin will properly release even when relatively low propellant charges are used. When using the spring 33, the pin will properly release even under the acceleration produced in an 81 m/m mortar, fourteen-pound stabilized projectile with a propellant charge of only eight grammes of powder.

From the rear end of the recess 1 to the transverse bore 2 I, the body 5 is provided with a flame passage 3 I, through which the flame for firing the detonator I8 passes, whether the fuse be set for instantaneous firing (Fig. 2) or for delayed firing (Fig. 4). In the old construction, both the instantaneous-fire primer and the delayed-fire primer were mounted in the rotatably adjustable head, causing difficulties above set forth. However, I mount the instantaneous-fire primer 32 in the body 5 across the flame passage 3| and mount only the delayed-fire primer 33 for the delay train 34, in the fuse nose 9, and while both

primers

32 and 33 are fired simultaneously when the fuse is set for instantaneous fire (Fig. 2), only the delayed-fire primer 33 will be fired when the nose 9 is set for delayed fire (Fig. 4) There is thus no danger of the instantaneous-fire primer 32 firing the detonator I8 and exploding the projectile charge, with the fuse set for delayed fire, as was possible with the old construction. Moreover, I provide an improved construction whereby flame from the delayed-fire primer 33 cannot leak around the cylinder 35 of the delay train 34 and fire the exciter 36 which is intended to be fired only by said delay train 34, whereas such an occurrence is possible with the 01d const uction, causing instantaneous firing even with the fuse set for delayed fire.

The exciter 36 is mounted in the reduced rear end 3'! of a longitudinal bore 38 extending rearwardly from the recess I2 in which the striker I3 is mounted, a forwardly facing shoulder 39 being formed at the juncture of the two bore diameters. I place a soft metal sealing washer 40 against this shoulder and provide the rear end of the cylinder 35 with a continuous rib 4| which abuts and becomes partly embedded in said soft metal washer 43 when the plug 42 which secures the primer 33 and the cylinder 35 in place, is tightened, said rib and washer, therefore, preventing any flame from leaking from the primer 33 directly to the exciter 36 and insuring that this exciter shall be fired only by the delay train 34.

A relatively short firing pin 43 is provided for the delayed-fire primer 33 and a comparatively long firing pin 44 is provided for the instantaneous-fire primer 32, both of said firing pins being suitably secured to the striker I3. The firing pin 43 is always in alinement with the primer 33 but the firing pin 44 is in alinement with the primer 32, only when the nose 9 is set for instantaneous firing as shown in Fig. 2. When the nose 9 is turned to the position of Fig. 4 to set the fuse for delayed firing, the firing pin 44 is moved to a position remote from the primer 32, and the exciter 36 and associated elements are moved into alinement with said primer 32. With the fuse thus set for delayed action, the primer 32 will not be fired by the firing pin 44, when the primer 33 for the delay train, is fired by the pin 43. stantaneous-fire primer 32 instantaneously effecting projectile explosion, with the fuse set for delayed explosion, as was possible with the old construction.

In order to insure against the firing pin 43 breaking and striking the primer 33 upon firing of the propellant charge, should such pin 43 be defective, I provide the plug 42 with an integral web portion 45 which is sufliciently strong to withstand any blow which might be delivered upon breaking and rearward movement of said pin 43, it being necessary that this pin shall be driven through the web 45 to fire the primer 33, the necessaryforce for so operating said pin, being in existence only when the striker I3 is driven rearwardly upon impact. It is not essential that the primer 32 be protected against firing should the pin 44 break upon firing of the projectile impelling charge, for any accidental firing of said primer 32 which might occur from this cause, would occurwith the detonator l8in unarmed position and consequentlythe projectile contents would not be exploded. However, it is important to protect the primer 33 for the delay train 34. With the fuse set for delayed fire, accidental firing of the primer 33 with the projectile still in the barrel, would not immediately subject the detonator I8 to a flame, but such flame would be delayed by the action of the delay train 34, and by the time the exciter 36 was fired by this delay train, said detonator I8 would have had time to be moved to armed position. The result would be premature explosion of the entire projectile immediately in front of the gun. This cannot occur, however, from a defective firing pin striking the primer 33, when the protecting web 45 is used.

When relying totally upon a shear pin such as I5, for holding the striker I3 until the pin is sheared, it is essential that said pin be sufficiently strong to prevent shearing when the propellant Thus, there is no danger of the incharge is fired, but if the fuse is to act when striking soft earth or water, said pin 15 must be comparatively weak. Experience has shown that a soft metal pin is required and that it is practically impossible to so accurately determine its strength as to give it the necessary toughness to prevent breaking while in the gun barrel, and the necessary weakness to shear when striking soft earth or water. However, I have provided novel means acting in addition to the shear pin I5, for positively holding the striker l3 against rearward movement until after the projectile has cleared the gun barrel. I am, therefore, enabled to make use of a shear pin of minimum strength acting primarily to hold the striker I3 against accidental outward movement from the recess l2 during handling of the fuse and projectile, and sure to shear even when said striker contacts soft earth or water.

In order to hold the striker 13 against any premature rearward movement, I interpose novel thrust-receiving means between said striker and the dual-function means which serves to normally hold the detonator l8 in safety position and to move said detonator to armed position, said dual-function means including both the slide 20 and the bolt 25 in the present disclosure. The thrust-receiving means in question is released only when movement of said dual-function means to armed position, occurs. This thrust-receiving means, in the present disclosure (see Fig. 3) includes two longitudinal rods 4-6 slidable in longitudinal bores 47 in the nose 9, and two blocks 48 interposed between the rear ends of said rods 36 and the bolt 25, said blocks being slidably received in short bores 49. The front ends of the rods 46 are in the rearward path of the striker l3, and a hard metal plate 55 is preferably provided at the rear end of said striker to contact with said front ends of said rods 46. As long as the bolt 25 is in place, the blocks 48 and rods 46 cannot slide rearwardly and consequently the striker I3 cannot be prematurely driven rearwardly, and this is so whether the fuse nose 9 occupy its instantaneous-fire setting or its delayed-fire setting.

I preferably provide transverse shear wires for holding the blocks 48 in position, even after the bolt 25 has been ejected. Thus, should the shear pin l5 be defective, the striker !3 will still be held against premature rearward movement. Upon impact, all of the pins l5 and 5! are, of course, sheared by the rearward movement of the striker l3 and said striker may thus actuate the firing pins, firing both

primers

33 and 32 if the fuse be set for instantaneous fire, but firing only the primer 33 if the setting be for delayed firing. By holding the striker l3 against being possibly driven rearwardly with the projectile still in the barrel, I overcome the possibility of premature and disastrous explosions immediately in front of the gun, whereas such occurrences could happen with the old construction. Moreover, this holding of the striker I3 is an important precaution against accidental explosion when handling the projectile, particularly desirable when said striker projects forwardly from the fuse nose, as herein disclosed.

The safety pin 52 which holds the pin 28 in the position shown in Fig. 3, from the time of manufacture until the projectile is to be fired, is preferably in the form of a cotter pin with outwardly bent ends 52 holding it normally in place, a jerk ring 53 being provided at the eye end of said cotter pin .for jerking it out of engagement with the pin 28 of the fuse body, at the desired moment.

A slidable pin 5t has been provided in the front end of the body 5 to 'coact with two sockets 55 in the nose 9, to hold this nose in its instantaneous setting or its delayed setting, said pin 54 having a conical front end 56 partially received in either of the sockets 55, said pin being urged forwardly by a coiled spring 57. This arrangement has been found to properly hold the nose 9 in ad justed position, yet to permit rather easy turning of said nose when desired, whereas the means provided in the old structure for holding the nose, was not satisfactory. During turning of the nose, it is of course necessary that the rear ends of the rods 45 shall encounter nothing to interfere with said turning. I, therefore, preferably bevel at least the abutting ends of these rods and the blocks 48, and it will be obvious that when turning the nose from one position to the other, each rod 46 leaves the block 43 with which it previously contacted, slides along the rear wall of the recess 7, and engages the other of said blocks 48. While one rod 46 cooperable with two blocks 48 might possibly be adequate, it is preferable to use two of the rods diametrically opposed with respect to the fuse axis.

From the foregoing taken in connection with the accompanying drawings, it will be seen that novel provision has been made for effecting the desired improvements, and while preferred details have been shown, variations may, of course, be made within the scope of the invention as claimed.

I claim:

1. In a fuse having a body, and a nose rotatably mounted on said body to be turned to an instantaneous-fire setting or to a delayed-fire setting; an instantaneous-fire primer carried by said body, a delayed-fire primer carried by said nose, a firing pin carried by said nose in permanent alinement with said delayed-fire primer, and a second firing pin carried by said nose, said second firing pin being alined with said instantaneous-fire primer when said nose occupies said instantaneous-fire setting but being spaced circumferentially of the fuse from said instantaneous-fire primer when said nose occupies said delayed-fire setting, whereby said second firing pin cannot fire sa id instantaneous-fire primer with danger of instantaneous explosion when the fuse is set for delayed explosion.

2. In a fuse having a body, and a nose rotatably mounted on said body to be turned to an instantaneous-fire setting or to a delayed-fire setting, said body having a flame passage; an instantaneous-fire primer carried by said body across said flame passage, a delayed-fire primer carried by said nose, a firing pin carried by said nose in permanent alinement with said delayed-fire primer, and a second firing pin carried by said nose; said delayed-fire primer being spaced circumferentially of the fuse from said instantaneous-fire primer, and said second firing pin being in alinement with said instantaneous-fire primer, when said nose occupies its instantaneous-fire setting; said delayed-fire primer being in firing relation with said instantaneous-fire primer, and said second firing pin being spaced circumferentially of the fuse from said instantaneous-fire primer when said nose occupies its delayed-fire setting.

3. In a fuse having a body, a rotatable nose carried thereby and turnable to either an instantaneous-fire setting or a delayed-fire setting,

means in said body for normally holding a detonator in a safety position and for automatically moving said detonator to armed position, and detonator firing means including a rearwardly movable striker carried by said rotatable nose; thrustreceiving means for holding said striker against rearward movement until the arming movement of the first mentioned means occurs, said thrustreceiving means including a portion carried by said rotatable nose, said thrust-receiving means being so related with said first mentioned means as to be normally held by this means whether said portion of said thrust-receiving means be moved to one position by instantaneous-fire setting of said rotatable nose or to another position by delayed-fire setting of said rotatable nose.

4. In a fuse having a body, a rotatable nose carried thereby and turnable to either an instantaneous-fire setting or a delayed-fire setting, means in said body for normally holding a detonator in a safety position and for automatically moving said detonator to armed position, and detonator-firing means including a rearwardly movable striker carried by said rotatable nose; thrust-receiving means for holding said striker against rearward movement until the arming movement of the first mentioned means occurs, said thrust-receiving means including front and rear portions carried by said rotatable nose and said body respectively and cooperable with each other whether said front portion be moved to one position by instantaneous-fire setting of said rotatable nose or moved to another position by delayed-fire setting of said rotatable nose, said rear portion of said thrust-receiving means being so related with said first mentioned means as to be held in operative position thereby until the arming movement of this means occurs.

5. In a fuse having a body, a rotatable nose carried thereby and turnable to either an instantaneous-fire setting or a delayed-fire setting, means in said body for normally holding a detonator in a safety position and for automatically moving said detonator to armed position, and detonator-firing means including a rearwardly movable striker carried by said rotatable nose; thrust-receiving means for holding said striker against rearward movement until the arming movement of the first mentioned means occurs, said thrust-receiving means including a rod slidable longitudinally in said rotatable nose and spaced radially from the axis of said nose, and two blocks longitudinally slidable in said body and normally held against rearward movement by said first mentioned means, said blocks being so spaced from the axis of said body that said rod will abut one of said blocks when said nose occupies its instantaneous-fire setting and will abut the other of said blocks when said nose occupies its delayed-fire setting.

6. In a fuse having a body, a nose rotatably mounted on said body to be turned to an instantaneous-fire setting or to a delayed-fire setting, detonator-carrying means mounted in said body for moving a detonator from a safety position to an armed position, automatically released means for locking said detonator-carrying means in safety position, including an ejectable bolt slidable transversely in said body, and firing means for said detonator including a rearwardly slidable striker carried by said rotatably mounted nose; thrust-receiving means for holding said striker against rearward movement until said bolt is ejected, said thrust-receiving means including a portion carried by said rotatably mounted nose,

said thrust-receiving means being so related with said bolt as to be normally held in operative position thereby whether said portion of said thrustreceiving means be moved to one position by instantaneous-fire setting of said rotatably mounted nose or moved to another position by delayed-fire setting of said nose.

7. In a fuse having a body, a nose rotatably mounted on said body to be turned to an instantaneous-fire setting or to a delayed-fire setting, detonator-carrying means mounted in said body for moving a detonator from a safety position to an armed position, automatically released means for locking said detonator-carrying means in safety position, including an ejectable bolt sliclable transversely in said body, and firing means for said detonator including a rearwardly slidable striker carried by said rotatably mounted nose; thrust-receiving means for holding said striker against rearward movement until said bolt is ejected, said thrust-receiving means including front and rear portions carried by said nose and said body respectively and cooperable with each other whether said front portion be moved to one position by instantaneous-fire setting of said nose or to another position by delayed-fire setting of said nose, said rear portion of said thrust-receiving means being so related With said bolt as to be held in operative position thereby until said bolt is ejected.

8. In a fuse having a body, a nose rotatably mounted on said body to be turned to an instantaneous-fire setting or to a delayed-fire setting, detonator-carrying means mounted in said body for moving a detonator from a safety position to an armed position, automatically released means for locking said detonator-carrying means in safety position, including an ejectable bolt slidable transversely in said body, and firing means for said detonator including a rearwardly slidable striker carried by said rotatably mounted nose; thrust-receiving means for holding said striker against rearward movement until said bolt is ejected, said thrust-receiving means including a rod slidable longitudinally in said rotatably mounted nose and spaced radially from the axis of said nose, and two blocks longitudinally slidable in said body and normally abutting the front side of said bolt to be held against rearward movement by this bolt until ejection thereof occurs, said blocks being so spaced from the axis of said body that said rod will abut one of said blocks when said nose occupies its instantaneous-fire setting and will abut the other of said blocks when said nose occupies its delayedfire setting,

9. In a fuse having detonator-carrying means for moving a detonator from a safety position to an armed position, automatically releasable means for holding said detonator-carrying means in safety position, and firing means for said detonator including a rearwardly movable striker; additional means engaging said automatically releasable holding means and held in operative position thereby, preventing rearward movement of said striker prior to release of said holding means, and a shear pin engaged with said additional means to further hold the same in operative position until said striker is driven rearwardly by impact.

10. A structure as specified in claim 4; together with a shear pin passing through said rear portion of said thrust-receiving means and a portion of said body for further holding said rear portion in operative position from the time said first mentioned means moves to armed position until said striker is driven rearwardly by impact.

11. A structure as specified in claim 8; together with shear pins passing through said blocks and portions of said body for further holding said blocks in operative position from the time said bolt is ejected until said striker is driven rearwardly by impact.

12. In a fuse having a recess and a primer therein, an imperforate plug threaded into said recess and securing said primer therein, said plug having a thinned imperforate web unitarily attached thereto and of a strength to be pierced only by a firing pin blow of greater than predetermined intensity, whereby the single unit formed by the plug and its web performs the blows.

HAROLD M. BRAYTON.