Plastic non-conductive explosive bolt

An explosive bolt is made of electrically non-conductive plastic material and is provided with a bore accommodating a low order deflagrating squid having only sufficient explosive energy to shatter a non-metallic bolt insulation surrounds the squib and fills the center bore and seals the squib in the center bore. There is a detonator for detonating the squib. Detonation of the squib is initiated by electrical current from an outside source electrically connected to the squib. A device has a stationary part and a removable part connected by the bolt.

BACKGROUND OF THE INVENTION 
The invention relates to electrically initiated explosive devices, 
particularly explosive bolts and to such bolts which may be used 
underwater as hinge connectors or simple fasteners but which are 
expendable when access past the hinged or bolted work piece is required. 
The invention is concerned with explosive bolts which shatter when exploded 
to provide access through openings such as doorways or hatches otherwise 
bolted closed by the unexploded bolt. More particularly, the invention 
pertains to such bolts which can better be used in marine environments. 
DESCRIPTION OF THE RELATED ART INCLUDING INFORMATION DISCLOSED UNDER 37 CFR 
1.97 AND 1.98 
An explosive bolt of the prior art is metal and is drilled from the top of 
its hex head along the axis of the bolt to accommodate a cup loaded with a 
relatively high order explosive which is detonated by electrical 
initiation of a primer. The explosion detonation shatters the bolt. The 
cartridge used in detonating metal bolts is metal and produces High order 
detonation which fractures the bolt. 
In another prior art construction explosive pressure drives a ram to the 
end of the bolt which is shorn off by the impact. The cartridge used in 
these conventional bolts is, as in the bolts that are shattered, metallic 
cased and contains several pyrotechnic/explosive components. The 
propellant produces high pressures which drive the ram or piston to 
shatter the end of the bolt. 
BRIEF SUMMARY OF THE INVENTION 
The present invention is directed to a plastic bolt which has been provided 
with a bore to accommodate a low order squib deflagration, the ignition 
composition of which is ignited by electrical activation of an initiator 
enclosed in the same cup as the initiation composition. 
The squib used in the plastic bolt is made entirely from plastic, PVC, 
glass, etc., except for the explosive mix and the initiation wires which 
are made of metal. The space in the bore around the metal (copper) wires, 
which terminate externally in a source of electrical power, is filled with 
epoxy. 
With a non-metallic squib, the entire bolt, less the wires, is 
non-conductive, and not readily detectable by metal detectors or x-ray. 
The squib may, however, be supplied in a metal cup if desirable for a 
particular application intended. 
The squib is a low order deflagrating high brisance energy source 
electrically initiated, in the preferred embodiment of the invention, and 
sufficiently destructive to shatter a bolt made of plastic. The plastic 
bolt is most desirable for use in marine environments to avoid rust and to 
provide a non conductive fastener to avoid unwanted electric currents. 
The plastic bolt of the invention can be made with a percussion initiator, 
instead of with an electrically initiated explosive, in which case there 
is no metal in the bolt.

DETAILED DESCRIPTION OF THE INVENTION 
In the drawings, the bolt 10 is fabricated, by molding or otherwise, of a 
non conductive plastic, PVC, glass etc. The bolt is threaded as at 11 
along the axial length of its cylindrical outer surface and has a 
hexagonal head 15 for rotational placement, via a wrench, not shown, 
within, and in this instance, through a nut 12 internally counter tapped 
to accept the thread of the bolt. 
The mounting of the bolt shown in FIG. 3 is specific to certain types of 
installations in which a stationary section or part 13 is joined to a 
removable part 14 of a device by the bolt which is threaded through 
aligned tapped holes in the parts such an arrangement is particularly 
suited to a submersible device 13, 14 such as an underwater observation 
station, where the station is the stationary part 13 having an inside 16 
and an outside 17 of the submersible device, and removable part 14 is the 
hatch. Nut 12 is fitted in the juxtaposed sides of the parts and acts to 
tighten the hex head against the outer surface of the removable part 14 
while the threads of the bottom end of the bolt draw the stationary part 
to and around the nut. In other types of installations, the nut may reside 
on the inner side if the stationary part to coact with the hex head to 
draw the parts tightly together. 
The bolt is fabricated with a center bore 20 to receive a low order 
deflagrating high brisance squib 21 which is detonated by insulated 
initiaion wires 22 and 23 carrying current from a source of electricity, 
not shown. The cavity surrounding the insulated wires if filled with epoxy 
to stabilize and insulate the squib. 
In the embodiment of the invention shown, the placement of the squib 
coincides with the plane of separation of the parts 13 and 14 so that when 
the bolt shatters, there will be no threading 11 to hold the two parts 
together. The nut 12 positioned in the separation area surrounding the 
plane of the squib's position assures centration of released energy from 
detonation in that area.