US3329091A - Pressure responsive mechanical firing device - Google Patents

Description

July 4, 1967 M. G. ANGELOS PRESSURE RESPONSIVE MECHANICAL FIXING DEVICE 2 Sheets--Sheet 1 Filed Aug. 17, 1965 7 INVENTOR 777z'zc/7eil G. Huge/0s 4 A v 4 7. W J WT 5/ 4 C .m a M w a. g

ATTORNEY;

July 4, 1967 M. G. ANGELOS 3,329,091

PRESSURE RESPONSIVB MECHANICAL FIXING DEVICE- Filed Aug. 17, 1965 2 Sheets-Shet 2 INVENTOR 77?z'z"cheZZ G. flngeios BY 1 )4 7 1,! 42% a. aga w V ATTORNEY;

United States Patent 3,329,091 PRESSURE RESPONSIVE MECHANICAL FIRING DEVICE Mitchell G. Angelos, Cockeysville, Md., assignor, by mesne assignments, to the United States of America as represented by the Secretary of the Army Filed Aug. 17, 1965, Ser. No. 480,533 1 Claim. (Cl. 102-70) ABSTRACT OF THE DISCLOSURE A mechanical firing device in which a pressure responsive diaphragm activates arming, time delay and firing mechanisms housed in the device to fire a detonator in a detachable coupling. The firing device is capable of use both in the air and under water and may be employed to detonate explosive charges.

This invention relates to a firing device and more particularly to a mechanical device used for initiating explosives in demolition work and actuated by the concussion produced from the detonation of a high explosive charge.

The device permits detonation of multiple demolition charges without electrical or explosive fuze connections between the charges.

The device is held safe by a mechanical time delay mechanism incorporated therein and a disarm feature permits the device to be readily made safe after the set arming time has elapsed.

The device is, further, suitable for use either underwater or in the air.

It is therefore an object of this invention to provide a firing device functioning in the air by the concussion produced from the detonation of a high explosive in a predetermined proximity thereto.

Another object is to provide a firing device adapted to function at a predetermined depth in either fresh or sea water.

A further object is to provide a firing device having a delay feature which holds it in a mechanically safe condition for a selectable period after removal of a safety wire.

A final object is to provide a firing device having a disarming feature which permits rendering it mechanically safe after the arming time has elapsed.

These and other objects and advantages of the present invention will be fully apparent from the following description when taken in connection with the annexed drawings, in which:

FIG. 1 is a side elevation of the firing device of this invention;

FIG. 2 is a top view thereof;

FIG. 3 is an axial section View taken along line 33 of FIG. 2 and looking in the direction of the arrows;

FIG. 4 is a cross section view taken along line 4-4 of FIG. 3 and looking in the direction of the arrows;

FIG. 5 is a cross section view taken along line 55 of FIG. 3 and looking in the direction of the arrows;

FIG. 6 is a cross section view taken along line 66 of FIG. 3 and looking in the direction of the arrows;

FIG. 7 is a cross section view taken along line 77 of FIG. 1 and looking in the direction of the arrows;

FIG. 8 is a perspective detail, partly in section, of the firing pin; and

16 to flange 12 and clamp diaphragm 15 securely therebetween.

Cover 16 is thereon.

An adapter plate 19 is secured to ribs 13 by bolts 20 and a firing pin assembly including a housing 21 is secured to the top side of plate 19 by bolts 22 (FIG. 4). Housing 21 is provided with a bore 23 (FIG. 3) and a pair of upstanding cars 24. Bore 23 is disposed diametrically in housing 11 as shown.

A lever 25 is pivoted at one of its ends to ears 24 by a pin 26 and is biased upwards by a spring 27. Lever 25 defines a raised portion 28 which is in contact with the underside of diaphragm 15 at its center point.

A firing pin 29 is slidably mounted in bore 23. Firing pin 29 is provided with a head 30 at one of its ends and head 30 carries a striker 31. A coil spring 32 encircles firing pin 29 and biases between head 30 and the end of bore 23.

Firing pin housing 21 is counterbored as at 33 and receives a first reduced portion 34 of firing pin 29 therein. A second reduced portion 35 on firing pin 29 is provided for a purpose to be described. Firing pin housing is further, notched as at 36 (see FIG. 8) and is milled out at one end to form a channel 37. A back plate 38 is welded in the channel 37 and forms a slot 39.

Firing pin housing 21 is supplied with a transverse keyway 40 along its bottom side.

A latch 41 is slidably mounted in slot 39 as best seen in FIGS. 3 and 9. Latch 41 is provided with an inturned tab 42 and a hole 43 having a diameter somewhat larger than the overall diameter'of firing pin 29. The latch 41 is received in reduced portion 34.

Firing pin 29 is retained in its cocked position by a safety bracket 44 (see FIG. 9).

Bracket 44 is provided with an integral bar 45 which rides in keyway 40. A downwardly turned tab 46, cut out of the floor of bar 45 is for a purpose to be described. One end of bracket 44 is bent in at a right angle as seen at 47 and its inner edge is cut to form a semicircular hole 48 which has a diameter substantially equal to the diameter of the second reduced portion 35 of firing pin 29.

Bracket 44 is biased outwardly in firing pin housing 21 by a coil spring 49 (see FIG. 4).

Visual means are provided for indicating when the detonator is in safe or armed condition and comprises a pin 50 fixed to an upturned end 51 of bar 45. Pin 50 has an integral indicator head 52 slidable in a bore 53 in housing 11.

A window 54 is provided in housing 11 and consists of a piece of transparent material 55 which is mounted proat its top side and ribs 13 (FIG. 6)

provided with openings 18 forming a grid 10 includes a tubular housing 11 which 3 over bore 53 by screws 56. Window 54 and bore 53 are in axial alignment with pin 50.

A boss 57 is integral with the upper portion of housing 11 and has a bore 58 threaded at one end. A detonator 59 is housed in bore 58 and receives a coupling base 68 therein. Coupling base 60 is for mounting on a charge to be detonated, not shown. Bore 58 is in axial alignment with bore 23 as seen in FIG. 3.

A time delay mechanism for tripping bracket 44 is provided and consists of a conventional spring-wound spaces 64 and bolts 65. The frame is further bolted to a pair of plates 62 and 63 held in spaced relation by timer 61 which is supported by a frame which comprises the adapter plate 19 by bolts 66 (see FIG.

A shaft 67 driven by timer 61 extends upwardly therefrom. A cam 68 (see FIG. 9) having a notch 69 is carried by the upper end of shaft 67. The circumferential edge of cam 68 normally engages tab 46 on bar 45 of bracket 44.

Means for winding timer 61 are provided and consist of a winding knob 70 rotatably mounted in an axial opening 71 in housing 11. Knob 70 is retained in opening 71 by a radially disposed pin 72 (see FIG. 3) which rides in annular groove 73 therein. Knob 70 is provided with a beveled portion 74 having indicia thereon and is adapted to register with a pointer 75 on the outside of housing 11 for setting the timing of the delay.

Knob 70 is axially bored as at 76 and counterbored as at 77 and receives a winding pin 78 slidable therein. Winding pin 78 is bifurcated at its top end as at 94 (see FIG. 6) and is provided with an enlarged lower end 79. Winding pin 78 is retained in bores 76 and 77 in knob 70 by a pin 80 riding in a keyway 81 in the body of knob 70 and limits the axial movement of pin 80.

Bifurcated end 94 of winding pin 78 is adapted to receive a pin 82 which is transversely carried by an arbor 83 integral with the bottom end of a shaft 84. Arbor 83 winds the timer 61. Hence, by pushing up knob 70, the bifurcated end 94 of pin 78 engages pin 82 so that by turning knob 70, the timer 61 may be wound.

A stop pin 85 fixed in the floor of housing 11 acts as a limit stop for pin 82 to prevent overwinding of timer 61 beyond the preset timing delay.

Enlarged portion 79 is provided with an axial bore 86 at its lower end. An extractor pin 87 is frictionally retained in bore 86 by a series of balls 88 which ride in an annular groove 89 formed in pin 87.

A cotter pin 90 is passed through knob 70 and winding pin 78. The cotter pin is attached to an arming wire 91 which, in turn, is attached to a ring 92 carried by extractor pin 87.

Operation Before operation, the firing device is coupled by coupling base 60 to a charge, not shown, to be destroyed.

Assuming that the firing pin 29 is in a cocked, safe position as shown in FIG. 3, the timer 61 is wound by turning knob 70 clockwise until pin 82 is stopped by stop pin 85. (The amount of turning is predetermined by the position of stop pin 85.)

The cotter pin 90 and extractor pin 87 are removed by pulling arming wire 91. Winding pin 78 then moves downward under bias of a spring 93 to free the bifurcated end 94 from pin 82. As long as winding pin 78 engages the winding arbor 83 the firing device 10 is unarmed due to froctional force on winding pin 78 by balls 88. In order to release the winding pin, extractor pin 87 must also be pulled out by wire 91.

The firing device 10 is now fully armed.

A blast occurring in the vicinity of the device will impinge on the diaphragm and pressure is transferred to raised portion 28 on lever which then moves sharply downward to strike tab 42 on latch 41 which is held in reduced portion 34 by the shoulders formed thereby. The latch 41 is moved downward in notch 36 so that hole 43 therein is in axial alignment with the firing pin 29.

After timer 61 runs down and pin 82 contacts stop pin 85, the notch 69 at this point will permit tab 46 to snap therein and safety bracket 44 will slide outward under bias of spring 49 to move bent portion 47 and semicircular hole 48 of reduced portion 34 and release firing pin 29 which strikes detonator 59 under urge of spring 32 to initiate firing of the charge (not shown) to be destroyed.

In case of a misfire, extractor pin 87 may be reinserted in winding pin 78 and pushed up to engage winding arbor 83 and the timer rewound until tab 46 snaps out of notch 69 to engage the circumferential edge of cam 68. The firing pin will be reset manually and latch 41 also and the device made safe.

One firing device can be employed to fire multiple charges by suitable arrangement of detonating devices.

It will be apparent that a novel firing charge has been provided and one that is entirely mechanical in its operation.

While a preferred form of the invention is shown and described, other forms of the invention are contemplated and numerous changes and modifications may be made therein without departing from the spirit of the invention as set forth in the appended claims.

What is claimed is:

A firing device comprising in combination, an outer housing, a coupling base detachably secured to the wall of said outer housing, a detonator in said coupling base, a flexible diaphragm secured in the top of said outer housing, an inner housing mounted in the upper portion of said outer housing, a spring loaded firing pin slidable in said inner housing and in axial alignment with said detonator and having first and second reduced portions at one of its ends; a first means associated with said first reduced portion on said firing pin for arming said firing device and including a spring-loaded bracket having an inwardly bent portion and an inwardly extending bar slidable in said inner housing and having a downwardly turned tab thereon, said bar being disposed normal to the longitudinal axis of said firing pin, said inwardly bent portion having a semicircular hole in its edge and engaging said first reduced portion on said firing pin to hold it in a safe position in said inner housing; a second means associated with said second reduced portion on said firing pin and responsive to inward pressure of said diaphragm to release said firing pin to fire said detonator and including an upwardly biased lever pivoted at one of its ends to said inner housing and disposed under said diaphragm, a latch vertically slidable in said inner housing, said latch having an inwardly turned tab at its upper end and disposed under the free end of said lever, a hole located centrally in said latch and having a diameter somewhat greater than the overall diameter of said firing pin, said hole normally being in an upward, offset position with respect to the longitudinal axis of said firing pin and receiving said second reduced portion therein whereby said firing pin will be held against axial movement in said inner housing until said latch is moved downward by said lever whereby said hole is in axial alignment with said firing pin; a time delay mechanism mounted in said outer housing for the predetermined release of said bracket from said firing pin and including a timer supported in said outer housing, a shaft rotated by said timer, a cam secured on the top of said shaft and having a notch therein and engaging said downwardly turned tab on said bar whereby when said cam is rotated said tab will enter said notch and permit said spring-loaded bracket to move away from said firing pin and arm said firing device; and a winding mechanism journaled in said outer housing for winding said timer, said last named mechanism including a winding shaft extending downwardly from said timer, said winding shaft having an arbor on its lower end and a transverse pin therein, a winding knob journaled in the 5 lower end of said outer housing and a spring-loaded shaft axially slidable in said knob, said last named shaft having a bifurcated upper end for engagement with said transverse pin in said arbor whereby said timer may be Wound by said spring-loaded shaft.

References Cited UNITED STATES PATENTS Porter 58-46 X Hammond -2 102-84 X MacLean et al. 10284 Chase 10270 X Kharasch et al 10284 BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL FEINBERG, Examiner.

10 G. H. GLANZMAN, Assistant Examiner.

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