US3411401A

US3411401A - Explosive driven guillotine

Info

Publication number: US3411401A
Application number: US634813A
Authority: US
Inventors: Darrel W Harris
Original assignee: Navy Usa
Current assignee: US Department of Navy
Priority date: 1967-04-26
Filing date: 1967-04-26
Publication date: 1968-11-19
Anticipated expiration: 1985-11-19

Description

Nov. 19, 1968 w, R s 3,411,401

EXPLOSIVE DRIVEN GUILLOTINE Filed April 26, 1967 /9 Q|Himiuumh ilml I INVENT OR /9 BARREL W HARE/5 BY Afro/Mr United States Patent ice 3,411,401 EXPLOSIVE DRIVEN GUILLOTINE Darrel W. Harris, Colonial Beach, Va., assignor to the United States of America as represented by the Secretary of the Navy Filed Apr. 26, 1967, Ser. No. 634,813 6 Claims. (Cl. 89-1) ABSTRACT OF THE DISCLOSURE An explosive driven cutting device having a guillotine blade capable of being lowered against a wire, rope, cable, tube, or like member for severing, the device being insertable along a confined detonating cord explosive train at a plurality of points whereby detonation along the train will serially effect a lowering of the guillotine blade for severance.

Government interest in the invention 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.

Cross-reference to related application This application is related to application Ser. No. 538,902, filed Mar. 25, 1966, now US. Patent No. 3,352,- 513, for Helicopter Rotor Shaft and Rotor Blade Severing Means.

Background of the invention The present invention is related generally to a cable cutting device and, more particularly, to a means for severing a plurality of cables in series through a single confined detonating cord. In helicopter and other aircraft escape systems, it has become necessary to completely separate the fuselage such that the crew occupying compartment can be independently lowered to safety from the remaining portion of the helicopter or aircraft. Various meeans have been heretofore designed for severing the electrical wiring, control cables and hydraulic lines in the helicopter escape system. Among the leading techniques used, are those of the shaped charge or of the cartridge actuated guillotines. Although the explosive shaped charge is capable of severing along a single explosive train, large explosive charges are required in order to insure complete severance of the circumferentially spaced members of the fuselage and the positioning of the charge in relation to the member to be cut must be closely controlled. In addition, fragment shielding becomes necessary because of the unconfined nature of the charge. On the other hand, the guillotine separation devices heretofore designed have been each equipped with a cartridge for lowering the guillotine blade against the member to be severed. While these devices have obviated many of the disadvantages inherent in the shaped charge separating means, their extended use in helicopter and other aircraft escape systems is rendered impracticable in view of weight problems and difficulties in designing adequate self-arming means. Moreover, these separation devices each require independent actuation from separate live cartridges. The present invention seeks to avoid the disadvantages of the prior art devices by providing an explosive driven guillotine blade which is lowered against the member to be cut as the explosive propagates along a confined detonating cord. A plurality of units, according to the instant design, are installed along the cord in order to facilitate a cutting of the lines and cables in series.

3,411,401 Patented Nov. 19, 1968 Summary of the invention An explosive driven cutting device consisting of a housing, a movable guillotine blade contained therein, and terminals of a confined detonating cord separated by a gap and in contact with the guillotine blade. Propagation of explosive along the cord produces a shock wave at a cord terminal to both lower the guillotine blade against a member to be cut, and, to actuate an adjacent cutting device along the cords as the shock wave jumps the gap.

It is therefore an object of the present invention to provide a cutting means capable of severing a plurality of wires, ropes, cables, etc, from a single detonating cord.

Another object of the present invention is to provide a cutting apparatus capable of being installed along any point of a confined detonating cord explosive train which apparatus is completely inert until installation in the explosive train.

A further object of the present invention is the provision of a cutting apparatus having a single moving element and being completely incapable of inadvertent actuation before installation in an explosive train.

Still another object of the present invention is to provide an explosive driven cutting device having the unique capability of transferring explosive energy therethrough.

Other objects, advantages and novel features of the invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.

Brief description of the drawings FIG. 1 is a partly broken away side view of the instant design showing the guillotine, cord terminals, anvil, and object to be cut;

FIG. 2 is a top view of the FIG. 1 device;

FIG. 3 is a bottom view of the FIG. 1 device;

FIG. 4 is a side view of the FIG. 1 device;

FIG. 5 is a sectoinal view taken at line 55 of FIG. 1;

FIG. 6 is a partly broken away showing of the cord terminal;

FIG. 7 is a perspective view of the guillotine blade; and

FIG. 8 is a schematic view showing a plurality of cutting devices installed along a detonating cord for severing a plurality of cables in series,

Description 0 the preferred embodiments Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIGS. 1 through 4 a cutting device 10 consisting of a housing 11 having a slot 12 therein for permitting a sliding movement of a guillotine blade 13 as it is lowered against a cable 14 or other object to be cut. A clear showing of the guillotine blade 13 appears alone in FIG. 7 of the drawings. The object 14 to be cut rests against an anvil 15 disposed along the lower end of housing 11. As is apparent from FIG. 1, a cut-out portion 16 is provided in housing 11 of a dimension sufficient to accommodate the object 14. In FIG. 5, the guillotine blade 13 is shown maintained in its initial position at a maximum distance from object 14, by means of a nylon head 17, adjustable through a set screw 18 mounted in the housing 11. At opposite sides of the housing 11, a pair of explosive cords 19, terminating in explosive filled caps 21, are threadedly secured, as shown, or are otherwise attached to the housing. An enlarged view of cord 19 is shown in FIG. 6 with part of the cap 21 broken away to show the explosive content thereof. As in FIG. 1, the ends of caps 21 are maintained apart so as to provide a gap 22, The explosive cord itself, while not a subject of the instant invention,

is preferably of the type of light weight and light powder grain dispersion which operates on a shock wave principle and is commercially available from several sources under the name of Confined Detonating Cord.

In operation of the instant device, initiation of the explosive in cord 19 from either direction is commenced from a source, not shown, and is propagated to either of cap 21 whereupon the shock Wave at gap 22 will perform two functions. It will lower the guillotine blade 13 into cutting engagement with the object 14 and come to rest against the anvil 15. The shock wave, at the same time, will jump the gap 22 and initiate the explosive in the other cap 21 to continue the propagation through the other cord 19. As is evident from FIG. 8 of the drawings, a severing of an object 14 adjacent the leftmost cutting device 10' will be effected in the same manner as just described. While a cutting of the second object 14 is taking place, detonation of the explosive will be propagated further to the third adjacent cutting device 10 and further through as many cutting devices as are installed aroundthe circumference of the fuselage. Separation of the objects 14 in this manner is accomplished by a clean cut through the use of a single moving part for a completely nonfragmenting severance.

The explosive driven guillotine of the instant design is a unique cutting device of particular application for the severing of electric wiring, control cables and hydraulic lines in the helicopter escape system heretofore cited as a related application. Such a cutting apparatus is a simpler design over those devices currently available, has fewer component parts, is smaller in size per unit, possesses greater reliability and is of significantly less cost than any of the prior devices heretofore devised. The explosive driven guillotine has an explosive charge of about onethird that required for a shaped charge. Its total weight is less than the weight of a shaped charge and requires no backup structure. The instant device also has the unique capability of transferring explosive energy therethrough, and, therefore, can be installed along any point in a confined detonating cord explosive train either in existing or newly assembled systems with little effort. The device is inert until it is so installed in the explosive train thereby rendering it completely safe until installed. Although the explosive driven guillotine has been designed for the helicopter escape system, it could be used in any military or civilian application requiring reliable severance of wiring, cables, tubing, etc.

Obviously many modifications and variations of the present invention are possible in the light of the above teachings. It is therefore to be understood that Within the scope of the appended claims the invention may be practiced otherwise than as specifically described.

What is claimed is:

1. A cutting device capable of severing a cable, wire, rope and the like, from an explosive detonating cord, said device comprising:

at least one housing;

a moveable guillotine blade disposed within said housing capable of being lowered against the object to be cut;

detonating means, said detonating means comprising a detonating cord having a pair of explosive caps mounted on the ends thereof; and

connecting means linking said detonating means to said housing in a spaced apart relation so as to provide a gap across which a shock wave is caused to jump thereby lowering said guillotine blade.

2. The device of claim 1 wherein a plurality of housings are provided along the explosive detonating cord whereby propagation may be transmitted through each housing by said shock wave thereby effecting a severance in series of objects to be cut.

3. The device of claim 1 wherein said guillotine blade contacts the sides of said connecting means and is maintained in contacting relation by a screw head mounted in one face of said housing.

4. The device of claim 3 wherein said housing, at a third side thereof, is provided with an open slot for receiving the object to be cut.

5. The device of claim 4 wherein said housing is provided with a longitudinally disposed anvil mounted through the walls of said slot at a distance from said guillotine blade so as to provide a surface against which said guillotine blade comes to rest after severing the object to be cut, v

6. The device of claim 5 wherein a plurality of housings are provided along the explosive detonating cord whereby propagation may be transmitted through each housing as said shock wave jumps each gap thereby effecting a severance in series of objects to be cut.

References Cited UNITED STATES PATENTS 3,032,356 5/1962 Botsford 10249.5 X 3,139,031 6/1964 Schroter et al. 102-49.5 X 3,246,396 4/ 1966 Temple et a1. 3,326,127 6/1967 Schimrnel 10227 SAMUEL W. ENGLE, Primary Examiner.