U.S. patent number 3,658,006 [Application Number 04/796,770] was granted by the patent office on 1972-04-25 for explosively actuated egress and ingress device and method.
This patent grant is currently assigned to Explosive Technology, Inc.. Invention is credited to Harold W. Hannagan, Gordon A. Nistler.
United States Patent |
3,658,006 |
Nistler , et al. |
April 25, 1972 |
EXPLOSIVELY ACTUATED EGRESS AND INGRESS DEVICE AND METHOD
Abstract
Explosively actuated egress and ingress device having a case
formed of relatively light-weight material with an outer surface
and having a linear-shaped explosive positioned within the case
adjacent to the outer surface and with a resilient backing material
in the case. A pliable gathering material may also be provided
within the case to the rear of the linear-shaped explosive charge.
The method includes the positioning of the devices for cutting
large holes.
Inventors: |
Nistler; Gordon A. (Vacaville,
CA), Hannagan; Harold W. (Napa, CA) |
Assignee: |
Explosive Technology, Inc.
(Fairfield, CA)
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Family
ID: |
25169016 |
Appl.
No.: |
04/796,770 |
Filed: |
February 5, 1969 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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740645 |
Jun 27, 1968 |
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Current U.S.
Class: |
102/307;
102/310 |
Current CPC
Class: |
F42B
3/08 (20130101) |
Current International
Class: |
F42B
3/08 (20060101); F42B 3/00 (20060101); F42b
003/08 () |
Field of
Search: |
;102/20,24,24HC,27 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Pendegrass; Verlin R.
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of application Ser. No.
740,645, filed June 27, 1968, and now abandoned.
Claims
We claim:
1. A self-contained explosively actuated ingress and egress device
for forming an opening in a wall-like structure having an exposed
surface, said device being detonatable from a safe distance from
said wall-like structure and comprising an enclosing case normally
surrounding the operative components of said device, said case
being formed of a relatively light-weight substantially
non-fragmentable material having an outer surface adapted to be
placed in engagement with the exposed surface of the wall-like
structure in which the opening is to be cut, a linear shaped
explosive charge positioned within the case adjacent said outer
surface and lying along a line which defines at least a portion of
the perimeter of the opening to be cut into the wall-like
structure, a resilient backing material mounted within said case to
the rear of the linear shaped explosive charge and surrounded by
said case, and integral self-contained means normally disposed
within and enclosed by said case for detonating said linear shaped
explosive charge; said last named means including an elongated
confined detonating cord operatively connected with said explosive
charge, and a firing mechanism operatively connected with said
confined detonating cord, said detonating cord and said firing
mechanism normally being enclosed within said case but being
selectively removable from the confines of said case and actuatable
from a distance when said explosive charge is to be detonated.
2. A device as in claim 1 together with a pliable gathering
material mounted in the case to the rear of the linear shaped
explosive charge.
3. A device as in claim 2 wherein said gathering material is in the
form of a flexible sheet surrounding said resilient backing
material.
4. A device as in claim 1 wherein said case is formed with a means
permitting an opening to be readily formed within the case to
permit access to the firing mechanism and to the confined
detonating cord.
5. A device as in claim 1 wherein said case is formed of a pair of
telescoping box-like sections.
6. A device as in claim 2 wherein said linear shaped explosive
charge, said backing material and said gathering material are in a
general alignment with the perimeter for the opening to be cut into
the wall-like structure.
7. A device as in claim 1 wherein said resilient backing material
is a closed cell syntatic foam.
8. A device as in claim 1 wherein said case is provided with flaps
which can be opened to permit access to said firing mechanism and
said confined detonating cord.
9. A device as in claim 1 together with means mounted on the case
to facilitate securing the case to the wall in which the opening is
to be cut.
10. A device as in claim 1 wherein said firing mechanism is
comprised of a housing, a bore in said housing for receiving said
confined detonating cord, a detonator mounted in the housing and
engaging the cord, a firing pin slidably mounted in the housing, a
spring means mounted in the housing for yieldably urging the firing
pin in the direction toward the detonator, a trigger mounted in the
housing being movable between the first and second positions, said
trigger in said first position preventing said firing pin from
moving into engagement with said detonator and in second position
permitting said firing pin to move into engagement with the
detonator and spring means yieldably urging the trigger into the
first position.
11. A device as in claim 1 together with a centrally disposed
compartment formed in said housing, said compartment being adapted
to receive an additional explosive charge, said case being formed
to permit access to said compartment.
12. A device as in claim 11 wherein said case and said linear
shaped explosive charge are formed so that said additional
explosive charge can be connected to said linear shaped explosive
charge for detonating said additional explosive charge.
13. A device as in claim 12 wherein said case is formed with a
compartment overlying the centrally disposed compartment for
receiving the elongate confined detonating cord and the firing
mechanism.
14. A device as in claim 1 wherein said resilient backing material
is Vermiculite.
15. A device as in claim 1 wherein said case is formed of a molded
plastic having a compartment disposed behind the linear-shaped
explosive charge and wherein said backing material is disposed in
said compartment.
16. A device as in claim 1 together with a centrally disposed
compartment formed in said housing, an additional explosive charge
in said centrally disposed compartment, and means for detonating
said additional explosive charge connected to said elongate
confined detonating cord.
17. A device as in claim 1 wherein said case is formed of plastic
and wherein said case has a weakened section in one wall, said
weakened section being capable of being broken out to permit access
to the firing mechanism and the confined detonating cord.
18. A device as in claim 1 together with safety means disposed
within the linear-shaped explosive charge for defeating the jet of
the linear-shaped explosive charge when it is detonated.
19. A device as in claim 18 wherein said linear-shaped explosive
charge is generally V-shaped in cross section and having a
generally V-shaped open recess extending longitudinally of the same
and wherein said safety means is in the form of wire disposed in
the open recess of the linear-shaped explosive charge.
20. A device as in claim 19 together with means carried by said
wire to facilitate ready removal of the same from the linear-shaped
explosive charge.
21. In an ingress and egress device adapted to be explosively
actuated for forming an opening in a wall-like structure having an
exposed surface, a case formed of a relatively light-weight,
substantially non-fragmentable material and which has an outer
planar surface adapted to be placed in engagement with the exposed
surface of the wall-like structure in which the opening is to be
cut, a linear-shaped explosive charge carried by the case adjacent
to the outer surface and lying along at least a portion of the line
forming at least part of the perimeter for the opening to be cut
into the wall-like structure, safety means within the case
removably mounted adjacent the linear-shaped explosive charge for
defeating the jet created by detonation of the linear-shaped
explosive charge prior to removal of said safety means from
adjacent said explosive charge, a resilient backing material
carried by the case and disposed to the rear of the linear-shaped
explosive charge, and integral self-contained means disposed at
least partially within said case for selectively detonating said
linear-shaped explosive charge.
22. A device as in claim 21 wherein said case is formed with a
compartment to the rear of the linear-shaped explosive charge and
wherein the backing material is disposed in the compartment to the
rear of the linear-shaped explosive charge.
23. A device as in claim 22 wherein said backing material is in the
form of Vermiculite.
24. A device as in claim 21 wherein said linear-shaped explosive
charge is substantially V-shaped in cross section and has an open
"V" extending longitudinally of the same and wherein said safety
means is in the form of a wire disposed in the open "V."
25. A device as in claim 24 together with means secured to the wire
for facilitating removal of the wire from the linear-shaped
explosive charge.
26. A device as in claim 21 wherein said linear-shaped explosive
charge is positioned along a substantially straight line.
27. A device as in claim 21 in which said means for detonating the
linear-shaped explosive charge is normally disposed entirely within
and enclosed by said case within a space provided therein to
receive said means for detonating the linear-shaped explosive
charge.
28. A device as in claim 27 wherein said case is provided with a
weakened section which is adapted to be broken to gain access to
the means for detonating the linear-shaped explosive charge.
29. In an assembly of the character described, first and second
devices adapted to be explosively actuated, each of said devices
comprising a case formed of a relatively light-weight,
substantially non-fragmentable material and which has an outer
surface adapted to be placed in engagement with the exposed surface
of the wall-like structure in which the opening is to be cut, a
linear-shaped explosive charge carried by the case adjacent to the
outer surface and lying along at least a portion of a line which
defines at least a portion of the perimeter for the opening to be
cut into the wall-like structure, safety means within the case
removably mounted adjacent the linear-shaped explosive charge for
defeating the jet created by detonation of the linear-shaped
explosive charge prior to removal of said safety means from
adjacent said explosive charge, a resilient backing material
carried by the case to the rear of the linear-shaped explosive
charge, means carried by each of the cases for detonating the
linear-shaped explosive charge carried thereby, and means
interconnecting said means for detonating whereby both of said
devices may be initiated substantially simultaneously.
30. An assembly as in claim 29 wherein said devices are
substantially straight and are adapted to be positioned in spaced
parallel positions whereby when they are initiated, they will cut
two relatively straight parallel lines.
Description
BACKGROUND OF THE INVENTION
In emergency operations of various types, it frequently becomes
necessary to gain immediate access to the inside of a structure
such as a building, ship's hold, grain elevator, aircraft fuselage,
or the like, for the purpose of rescue, fire fighting or similar
types of emergency operations. Forced entry of this general type
normally has employed the use of conventional or specialized hand
implements such as axes, saws, pry bars, battering rams and
oxy-acetylene cutting torches. More recently, motorized saws have
been used. Although each of these implements or devices has been
used for a number of years, they all have disadvantages
particularly in that most of them require considerable time to use
and are frequently ineffective or hazardous for one reason or
another. For example, chain saws are now used rather extensively by
fire fighters for emergency roof ventilation and the like. A not
uncommon incident is for the saw blade to encounter live electrical
wires when cutting into the structure. Such an occurrence is
obviously dangerous to the operator of the chain saw. In an attempt
to overcome these disadvantages, explosives, per se, have been
utilized in an attempt to gain forcible entry into structures.
However, these attempts have largely utilized techniques associated
with rock blasting and have generally employed stick dynamite or
blasting gelatin. The result is inefficient utilization of energy,
relatively unsafe operation, and inordinate damage to the structure
being breached. Also in such operations it is necessary to clear
personnel and bystanders to a remote location from the point of
explosion because of the fragment hazard and the concussion. There
is, therefore, need for a new and improved explosively actuated
egress and ingress device.
SUMMARY OF THE INVENTION AND OBJECTS
The explosively actuated egress and ingress device for forming an
opening in a wall-like structure having an exposed surface consists
of a case which is formed of a relatively light-weight material and
which has an outer surface adapted to be placed in engagement with
the exposed surface of the wall-like structure in which the opening
is to be cut. A linear-shaped explosive charge is positioned in the
case adjacent to the outer surface and lays along at least a
portion of a line which defines the perimeter for the opening to be
cut into the wall-like structure. A resilient backing material is
mounted in the case to the rear of the linear-shaped charge with a
pliable gathering material which is also provided in the case to
the rear of the linear-shaped explosive charge.
In general, it is an object of the present invention to provide an
explosively actuated egress and ingress device and method which can
be utilized by relatively unskilled personnel.
Another object of the invention is to provide a device of the above
character which can be rapidly and readily placed in operation.
Another object of the invention is to provide a device of the above
character which is relatively fool-proof.
Another object of the invention is to provide a device of the above
character which can be readily manufactured and which is relatively
inexpensive.
Additional objects and features of the invention will appear from
the following description in which the preferred embodiments are
set forth in detail in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view showing an explosively actuated egress
and ingress device incorporating the present invention for use in
cutting an opening in a rolling door.
FIG. 2 is a top plan view of the device shown in FIG. 1 with the
flaps in an open position.
FIG. 3 is a cross-sectional view taken along the line 3--3 of FIG.
2.
FIG. 4 is an enlarged cross section view of the trigger mechanism
for actuating the device.
FIG. 5 is a cross-sectional view taken along line 5--5 of FIG.
4.
FIG. 6 is a perspective view of another embodiment of the device
incorporating the present invention mounted upon a wall for cutting
a hole into the wall.
FIG. 7 is a top plan view of the device shown in FIG. 6 with the
flaps in an open position.
FIG. 8 is a top plan view of still another embodiment of a device
incorporating the present invention.
FIG. 9 is a plan view of the under side of the lid of the device
shown in FIG. 8.
FIG. 10 is a cross-sectional view taken along the line 10--10 of
FIG. 8.
FIG. 11 is a cross-sectional view taken along the line 11--11 of
FIG. 8.
FIG. 12 is a bottom plan view of the device shown in FIG. 8 with
certain portions broken away.
FIG. 13 is a top plan view of the device shown in FIG. 8 with the
center section of the lid broken out and with portions of the lid
broken away.
FIG. 14 is a cross-sectional view taken along the line 14--14 of
FIG. 12.
FIG. 15 is a cross-sectional view taken along the line 15--15 of
FIG. 14.
FIG. 16 is a cross-sectional view taken along the line 16--16 of
FIG. 14.
FIG. 17 is a greatly enlarged view, partially in cross section, of
the means utilized for firing the device shown in FIG. 8.
FIG. 18 is a top plan view of still another embodiment of a device
incorporating the present invention.
FIG. 19 is a bottom plan view of the lid of the device shown in
FIG. 18.
FIG. 20 is a cross-sectional view taken along the line 20--20 of
FIG. 18.
FIG. 21 is a bottom plan view of the device shown in FIG. 18 with
certain portions broken away.
FIG. 22 is a top plan view of the device shown in FIG. 18 with
certain parts removed therefrom.
FIG. 23 is a top plan view of the device shown in FIG. 18 with the
center section broken out.
FIG. 24 is a top plan view of a combination of devices
incorporating still another embodiment of the invention showing the
manner in which they would be arranged for cutting a large hole in
a roof or similar structure.
FIG. 25 is a side elevational view of one of the devices shown in
FIG. 24 with certain portions broken away.
FIG. 26 is a cross-sectional view taken along the line 26--26 of
FIG. 25.
FIG. 27 is an isometric view of a package assembly showing the
manner in which the explosively actuated ingress and egress devices
can be packaged for shipment.
FIG. 28 is a partial cross-sectional view taken along the line
28--28 of FIG. 27.
BRIEF DESCRIPTION OF THE PREFERRED EMBODIMENTS
The explosively actuated egress and ingress device consists of a
case 11 which is formed of a relatively light-weight
non-fragmentable material such as cardboard. The case is formed in
two box-like parts 12 and 13. Both the box-like parts 12 and 13 are
provided with the spaced parallel sidewalls 14 and spaced parallel
endwalls 16 and a top or a bottom wall 17. The part 12 is slightly
larger than the part 13 so that the two parts can be telescoped
together as shown in FIG. 3 to provide a complete enclosure. The
two parts 12 and 13 are bonded together by a suitable means such as
an adhesive and, in addition, the edges can be sealed with tape 18
so that the case is substantially water-proof.
The case 11 is provided with a substantially planar outer surface
formed by the bottom wall 17 of the inner box-like part 13 which is
adapted to be placed against the exposed surface of the wall-like
structure in which an opening is to be cut.
A linear-shaped explosive charge 21 is disposed immediately
adjacent the inner surface of the bottom wall 17 of the inner
box-like part 13 of the case 11. The linear-shaped explosive charge
can be of any suitable type as, for example, "Jetcord" manufactured
and sold by Explosive Technology, Inc. of Fairfield, California. As
is well known to those skilled in the art, such a linear-shaped
explosive charge consists of a shaped metal member 22 of a suitable
material such as lead which is substantially V-shaped or chevron
shaped in cross section to concentrate the explosive effects. The
open side of the "V" or chevron is positioned so that it faces in
the direction in which the cut is to be made. The explosive charge
23 is embedded within the metal member 22 and extends
longitudinally of the metal member. The explosive charge can be of
any suitable material such as RDX, PETN, TNT or any powdered
explosive. The linear-shaped explosive charge 21 is arranged in a
predetermined pattern as, for example, the perimeter of the opening
which is to be cut with the device. Thus, as shown in FIG. 2, the
linear-shaped explosive charge 21 can be formed into a circle to
provide a circular opening of the desired size.
A resilient backing material 26 of a suitable type such as a closed
cell syntactic plastic foam is applied to the rear of the charge
21. A supporting and/or gathering material 27 which is relatively
pliable also is provided to the rear of the explosive charge and
either can be provided within the backing material 26 or can
surround the outside of the resilient backing material. Thus, as is
shown in FIG. 3 of the drawings, the gathering material 27 can take
the form of a rubber sheet which envelopes the outer surface of the
syntactic foam which serves as a resilient backing material 26. The
resilient backing material is in the form of a circle and is
generally rectangular in cross section as can be seen in FIG. 3.
The gathering material 27 is generally U-shaped in cross section
and covers the side and the rear surfaces of the resilient backing
material. Alternatively, the gathering material 27 can be a woven
fabric such as woven Nylon or it can be in the form of chopped
Nylon roving dispersed within the syntactic foam which makes up the
resilient backing material. As can be seen, the resilient backing
material 26 with the gathering material 27 substantially fills the
outer peripheral portions of the case 11 but leaves a cylindrical
space 28 in the center.
Means is provided for detonating the linear-shaped explosive charge
and consists of a non-electric blasting cap 31 of a conventional
type which is embedded within the resilient backing material 26 and
is in engagement with the linear-shaped explosive charge. A
confined detonating cord 32 of a conventional type is connected to
the blasting cap 31 and extends outwardly through a hole 33 in the
gathering material 27 and is connected to a firing mechanism 34.
The firing mechanism 34 consists of a housing 36 formed of a
suitable material such as plastic. The housing 36 is generally
cylindrical and is of a size which can be readily grasped by hand.
The confined detonating cord extends into a bore 37 provided in the
housing. A percussion detonator 38 is mounted in the housing 36 and
is in engagement with the end of the detonating cord 32. The
detonator 38 is adapted to be detonated by firing pin 39 slidably
mounted in the housing 36 and yieldably urged in a direction toward
the detonator 38 by a coil spring 41. The spring 41 is mounted in a
well 42 provided in the housing 36 and has one end engaging a
collar 43 provided on the firing pin 39.
The firing pin 39 is normally retained out of engagement with the
detonator by a trigger member 46 which is slidably mounted in a
bore 47 in the housing 36 extending at right angles to the bore 37.
The trigger mechanism 46 is provided with a bore 48 which is of
such a size so that the firing pin 39 can travel therethrough. The
trigger member 46 is also provided with a slot 49 which opens into
the bore 48 and is adapted to receive the pointed tip 39a of the
firing pin 39 as shown in FIG. 4. Spring means in the form of a
waffle spring 51 is provided for yieldably urging the trigger
member outwardly so that the slot 49 of the trigger member is
engaged by the pointed end 39a of the firing pin. Safety means is
provided for preventing operation of the trigger member until it is
removed and consists of a safety pin 52 which extends through the
housing 36 and through the trigger member 46. The firing pin 39 is
provided with a pull ring 53 to permit cocking of the firing pin
against the force of the spring 41. The firing mechanism with the
confined detonating cord is normally stored within the cylindrical
recess 28 provided within the case 11.
The top wall of the box 17 is perforated to provide two flaps 17a
and 17b which can be opened to expose the recess 28 and to permit
access to the firing mechanism 33 and the confined detonating cord
32. Before use of the device, the flaps 17a and 17b are in closed
positions with the firing mechanism stored within the recess
28.
If desired, means may be provided in or on the case for securing
the case to the wall in which a hole is to be cut. Thus, for
example, four magnets 56 can be provided in the four opposite
corners of the case 11 adjacent the bottom wall 17 of the inner
part 13. These magnets are of such strength and size so that they
can readily support the device upon a steel door or the like in
which a hole is to be cut.
Let it be assumed that an emergency has arisen and that it is
desired to cut a hole in a steel door which is the steel door 61
shown in FIG. 1 in the drawings in the sidewall of a building 62.
The user would quickly grab one of the devices and would merely
place it against the steel door and it would be held on the steel
door in the desired position by the magnets 56 within the case. The
perforated flaps 17a and 17b would be broken by the fist and the
flaps 17a and 17b opened as shown in FIG. 3 to permit immediate
access to the firing mechanism 33. The operator would then quickly
grab the firing mechanism and pull out the confined detonating cord
32 to the extent of the length of the cord which in a typical
device can be 30 feet to permit the operator to move a sufficient
distance to permit safe operation of the device.
The safety pin 52 is then removed and the trigger 46 is actuated
against the force of the spring 52 by the same hand which is
holding the firing mechanism 46 to permit the spring 41 to force
the firing pin through the hole 48 and to detonate the percussion
detonator 38. The percussion detonator 38 ignites the cord which
detonates the blasting cap 31. The detonation of the blasting cap
31 detonates the linear-shaped explosive charge which immediately
cuts through the steel door 61 against which it is placed to
provide a relatively large hole so that a man can crawl through the
same and enter the building. All this can be accomplished in a very
few minutes because the device is a relatively light-weight device
and can be easily manipulated because of its practical size and
bulk. It also provides the necessary degree of safety.
When the linear-shaped charge is detonated, the high pressure gases
or shock waves which are generated are dispersed and attenuated by
the geometry of the voids that constitute the macroscopic air holes
in the foam. This has the overall effect of normalizing the
pressure points emanating from the explosion and thereby extends
the pressure release duration and reduces the over-pressure in the
proximity of the explosion. The plastic foam also serves to
decelerate the fragments that result from the fragmentation of the
metal sheath of the linear-shaped explosive charge. It also
collects the fragments within the foam in which they are embedded.
If and as the foam structure begins to fracture into large
segments, the foam presents a significant aerodynamic drag so that
the fragments, in their foam encapsulation, travel only a few feet.
The gathering or supporting media around the foam minimizes the
break-up of the foam and increases the size of the broken-up foam
sections and thereby reduces the distance that they will be
propelled. Thus, it has been found that the device can be operated
with great safety at a distance of as little as 30 feet.
Although the invention has been described with a closed cell foam,
other foams can be utilized. A closed cell foam is desirable
because it will not absorb water as readily as will an open celled
foam. If an open celled foam were to be used, it would lose its
shock attenuating characteristics if it absorbed water. It has been
found that a closed cell foam which has been foamed to a density of
approximately 6 lbs. per cubic foot is particularly satisfactory.
It has also been found that the lower limit of effectiveness is
approximately 3 lbs. per cubic foot and that the upper limit is
approximately 10 to 15 lbs. per cubic foot at which time the foam
becomes prohibitively heavy and its effectiveness as a shock
attenuator is reduced.
Although there has been described one particular way of initiating
a linear-shaped charge, other conventional ways can be utilized.
However, the use of electrical blasting caps may be undesirable in
the vicinity of high voltage electric lines in an emergency
situation. Time-delayed fuses also may be undesirable where people
may be wandering around such as at a fire.
Another manner for attaching the device to a wall is shown in FIG.
6 in which the device has been provided with a handle 66. With such
a handle, a nail 67 can be pounded into the wall 62 and the device
quickly hung on the nail and then operated in the same manner as
hereinbefore described to blast a hole quickly in a wall.
The device as disclosed can be constructed to cut any desired size
and shape of hole. Thus, as shown in FIG. 7, a generally
rectangular opening can be cut if desired.
Another embodiment of the explosively actuated egress and ingress
device is shown in FIGS. 8-17 and is particularly adapted for use
on steel rolling doors. It cuts an opening which is square in shape
and has a suitable size such as a 2 ft. square. The opening is cut
by cutting an inverted "U" in the steel rolling door which creates
a flap which will fold down as soon as the device is actuated to
create the square opening. There is no necessity for cutting across
the bottom of the rolling door because of the construction of the
rolling door which permits the flap to drop downwardly along the
fold line of one of the slats of the rolling door.
The device shown in FIGS. 8-17 consists of a housing or case 71
which is formed of a relatively light-weight non-fragmentable
material such as molded polystyrene. The case 71 is formed in two
parts: one of which is a box 72, and the other of which is a lid
73, both of which are formed of polystyrene. The box 72 is of a
unitary construction and is provided with a bottom wall 76 which is
generally planar as shown in FIG. 10. The box 72 is also provided
with spaced parallel upstanding side walls 77 and 78 and spaced
parallel upstanding end walls 79 and 81 which join with the walls
77 and 78 to provide a rectangular enclosure. A first or inner
compartment 82 is formed within the confines of the walls 77, 78,
79 and 81 by spaced parallel side walls 83 and 84 which are spaced
from and parallel to the walls 77 and 78 and an end wall 86 which
is spaced from and parallel to the end wall 79. The walls 83, 84
and 86 cooperate with the end wall 81 to provide the four-sided
first or inner compartment 82.
A U-shaped second or outer compartment 87 is formed between the
walls 83, 84 and 86 forming the inner compartment 82 and the walls
77, 78, 79 and 81 which form the outer extremities of the box 72. A
pair of spaced parallel reinforcing walls 88 and 89 extend between
the walls 79 and 87. The bottom wall 76 of the box 72 is provided
with a U-shaped raised portion 76a which is generally V-shaped in
cross section as can be seen in FIG. 10 and which is centered with
respect to the portion of the bottom wall that forms the outer or
second compartment 87. This raised portion 76a is generally
U-shaped in plan as is the compartment 87. A recess 91 which is
generally V-shaped in cross section is formed in the bottom wall 76
and underlies the raised portion 76a of the bottom wall so that it
also extends the entire length of the U-shaped outer or second
compartment 87. The recess 91 opens outwardly through the outer
surface of the bottom wall 76.
A lid 73 has the same configuration as the box 72 and is adapted to
form a cover for the open side of the box 72. The cover is provided
with means whereby a predetermined section 73a of the cover may be
broken out without destroying the remainder of the lid. Thus, the
cover 73 has been provided with a recess 94 which is generally
V-shaped in cross section as can be seen from FIG. 10 which is in
the form of a rectangle in plan as seen in FIG. 9. The recess 94 is
positioned so that the rectangle which is formed thereby generally
overlies the first or inner compartment 82 to facilitate access to
the compartment 82. In order to facilitate ready break-out of the
section 73a which is defined by the recess 94, additional recesses
96 and 97 which are also V-shaped in cross section are provided in
the bottom side of the lid 73 and form an "X" in plan as shown in
FIG. 9. The lid 73 is also formed with a downwardly depending
bulging portion 73b which also forms a rectangle in plan that is
generally the same size as the first or inner compartment 82 so
that it will fit within the first or inner compartment as shown in
FIG. 10 and to thereby position the lid 73 on the box 72. The lid
73 is provided with a planar outer surface 98 which is generally
parallel to the outer surface of the bottom wall 76 of the box 72.
As can be seen from FIG. 8, the lid 73 can be provided with
suitable printing to indicate the section 73a which is to be broken
out and a description where the lid should be punched by hand to
break out the section 73a.
A linear-shaped explosive charge 101 is disposed within the recess
91 provided in the bottom wall 76 of the box 72. As explained
previously, this linear-shaped explosive charge can be of any
suitable type such as "Jetcord" manufactured and sold by Explosive
Technology, Inc. of Fairfield, Cal. As shown particularly in FIG.
15, such a linear-shaped explosive charge consists of a shaped
metal member 102 of a suitable material such as lead which is
substantially V-shaped or chevron shaped in cross section to
concentrate the explosive effects. The open side of the "V" or the
chevron is positioned so that it faces in the direction in which
the cut is to be made. An explosive charge 103 is embedded within
the metal member 102. The linear-shaped explosive charge 101
extends the entire length of the U-shaped recess 91 so that it
generally underlies the outer or second compartment 87 of the box
72.
Means similar to that hereinbefore described is provided for
detonating the linear-shaped explosive charge 101 and consists of a
non-electric blasting cap 106 which is in engagement at one end of
the linear-shaped explosive charge 101 as shown in FIG. 14. The
blasting cap 106 is adapted to be detonated by a confined
detonating cord 107 of a conventional type. The blasting cap 106
and the confined detonating cord 107 are disposed in a recess 108
provided in the bottom wall and which continues into an opening 109
provided in the bottom wall 76 so that the detonating cord 107 can
extend upwardly into the box 72 within the inner compartment 82 as
shown in FIG. 13. As can be seen from FIG. 13, a substantial length
of the confined detonating cord as, for example, 30 ft., is coiled
within the inner compartment 82 in the form of a figure "8." The
end of the cord 107 is provided with a fitting 111 which contains a
percussion initiator 113 which, when acted upon by a firing
mechanism 114, will initiate a primer 116. The primer 116 initiates
an intermediate charge 117 which, in turn, initiates the confined
detonating cord 107. The outer end of the fitting 111 is provided
with threads 118 and is adapted to have threaded thereon the firing
mechanism 114. The fitting 111 on the end of the cord 107 and the
firing mechanism 114 are mounted in a slotted holder 121 secured to
the bottom wall 76 of the box 72. The firing mechanism 114 consists
of a tubular member 122 which is threaded onto the fitting 111. A
firing pin 123 is slidably mounted within the member 122 and is
provided with a pin 124 which extends outwardly at right angles
therefrom through a slot 126 provided in the tubular member 122. A
knob 127 is mounted on the pin and is adapted to be grasped by the
hand. A spring 128 mounted within the tubular member yieldably
urges the firing pin 123 in a direction towards the percussion
initiator 113. The spring is held in place by a knurled cap 129
threaded into the end of the tubular member 122. It can be seen
that by grasping the knob 124 and moving it out of one portion of
the slot 126 and releasing the same, the spring will urge the
firing pin 123 into rapid engagement with the percussion initiator
113 to initiate the same.
In FIG. 17 a line extension 131 has been provided to permit firing
of the explosively actuated ingress and egress device from a
greater distance. This line extension 131 consists of a length of
confined detonating cord 132. The length is chosen so that there is
more than ample distance for initiating the explosively actuated
ingress and egress device from a distant location as, for example,
100 ft. One end of the extension line 131 is provided with a
fitting 111 similar to that hereinbefore described. The other end
of the line is also provided with a fitting 133 in which the
confined detonating cord 132 is mounted. In addition, there is
provided an intermediate charge 134 which ignites the primer 136.
The primer 136 initiates the percussion initiator 113 which is
carried by a coupling 137 which is threaded onto the fitting 111
provided on the cord 107. The coupling 137 is retained on the
fitting 133 by a snap ring 138. With the extension line 131
constructed in this manner, it can be readily seen that one or more
extension lines can be utilized to place the necessary distance
between the explosively actuated ingress and egress device and the
person operating the same.
The linear-shaped explosive charge 101 forms a thin wedge-shaped
jet of energy when it is initiated. Means is provided for depleting
this jet in the event that the linear-shaped explosive charge 101
is inadvertently initiated. This means consists of a relatively
thin wire 141 which is disposed in the open V-shaped recess 142 of
the linear-shaped explosive charge 101 and extends the entire
length of the linear-shaped explosive charge. A portion of the wire
141 extends outwardly from the box 72 and is formed into a loop 143
which carries a warning tag 144. The warning tag states that the
wire 141 must be pulled completely out of the box 72 so that it
will not defeat the jet which is created by the linear-shaped
explosive charge. The wire 141 can be formed of any suitable
material. However, it should have certain characteristics. For
example, it should be relatively ductile so that it can be readily
pulled out of the recess 142 of the linear-shaped explosive charge.
In addition, it should have a relatively high density. Lead has
been found to be particularly desirable for this purpose. It is
believed that the wire 141 serves to defeat the jet because the
wire 141 is, in fact, positioned along the line at which the jet
would be formed. In addition, the wire 141 serves as a shock
attenuator or dispersant to prevent shock waves from forming. Thus,
the wire 141 serves to defeat the essential elements which are
required to form a jet from a linear-shaped explosive charge. Since
the jet is defeated, there will be substantially no cutting action
from the linear-shaped explosive charge in the event it is
inadvertently initiated.
Even though a single wire 141 has been utilized for the three-sided
configuration of the explosive charge 101, it should be appreciated
that, if desired, particularly if it is very difficult to pull a
wire extending the entire length of the recess 142, that a separate
wire could be provided for each side of the V-shaped configuration
of the explosive charge 101. When this is the case, three places
would be provided for removing the wires from the box 72. A face
panel 146 of a suitable material such as cardboard is secured to
the bottom side of the bottom wall 76 by suitable means such as
cement and serves to hold the jet defeating wire 141 in place as
well as to hold the linear-shaped explosive charge 101 in
place.
A backing material 148 is provided in the outer or second
compartment 87 and instead of the plastic foam hereinbefore
described, a relatively light granular material in the form of
Vermiculite is used. The compartment 87 is vibrated so that the
compartment is completely filled with Vermiculite and so that it
will not settle and leave any empty space during transportation of
the device. After the compartment 87 has been filled, a layer of
cardboard 149 is placed over the Vermiculite in the compartment 187
as shown in FIG. 10. This cardboard layer 149 is utilized to hold
the Vermiculite in place until the lid 73 can be secured to the box
72 by suitable means such as by the use of an adhesive. A handle
151 is mounted in the box 72 and is formed of a suitable material
such as 1/4 inch Nylon rope. The Nylon rope extends through holes
152 provided in the walls 88 and in the wall 87 and the ends of the
same are fastened together by metal splicers 153. The splicers
serve to form the Nylon rope into a continuous loop so that it
serves as a handle 151.
Operation and use of the explosively actuated ingress and egress
device shown in FIGS. 8-17 may now be briefly described as follows.
Let it be assumed that it is desired to cut a hole in a steel
rolling door to obtain quick access to the fire within a building
in which the door is mounted. The fireman or other individual
utilizing the device carries the same by the handle and uses a
magnet which carries a hook (not shown) which is secured to the
door and then the handle 151 is secured to the hook. The device
always must be positioned on the door so that the face plate 146
faces the door and is flat against the vertical surface of the
door.
Alternatively, as hereinbefore described, the device can be
provided with magnets which would hold the device to the door in
the appropriate place. As soon as this has been accomplished, the
fireman uses his fist and strikes the weakened section 73a which
says "punch here" shown in FIG. 8. This causes the polystyrene to
break along the lines of the V-shaped grooves 94, 96 and 97 to
provide a rectangular opening 154. The section which has been
broken out can be removed to expose the cord 107. At this time, the
jet defeating wire 141 is removed by pulling on the loop 143 as
shown in FIG. 13. As soon as the wire 141 has been removed, the
fitting 101 and the firing mechanism 114 are removed from the
holder 121. It should be appreciated that the jet defeating wire
141 can be removed before the device is mounted on the door. The
fireman then uncoils the cord 107 and goes to a remote location and
threads the firing mechanism onto the fitting 111.
After the cord 107 has been payed out to its full length and
without pulling the device away from the door in which the cut is
to be made, the operator then faces away from the device and
operates the firing mechanism by releasing the firing pin. This
causes detonation of the cord in the manner hereinbefore described
and also causes initiation of the linear-shaped explosive charge.
This causes the desired hole to be cut into the rolling door. The
hole will be cut between the two sides and the top of the door
which will form a flap which will drop downwardly along the closest
articulated joint of the rolling door to thereby permit ready entry
into the building.
It has been found that the construction as shown in FIGS. 8-17 is
particularly advantageous. One difference from that of the previous
embodiment is that the groove which contains the linear-shaped
explosive charge 101 is on the side of the bottom wall 76 rather
than on the inside. This is advantageous for a number of reasons.
For example, this makes possible the formation of a V-shaped groove
in the outer surface of the bottom wall and ensures that the
linear-shaped explosive charge will be positioned in the middle of
the backing material 148. In addition, this construction provides
means for isolating the jet which is generated by the linear-shaped
explosive charge from the backing material 146. This is important
because this prevents the backing material from seeping down into
the recess 142 in the linear-shaped explosive charge which could
interfere with the effectiveness of the jet which is formed by the
linear-shaped explosive charge.
It has been found that the Vermiculite utilized as the backing
material is particularly effective for capture of fragments and for
attenuation of the shock waves and noise. The utilization of a
plastic such as polystyrene for the case 71 has also been found to
be particularly desirable. It is relatively economical and is
particularly effective when it has a density ranging from
approximately 2 to 4 lbs. per cubic foot. Such a density gives
adequate strength to the case and when the linear-shaped explosive
charge is detonated will not break into fragments which are
dangerous. This material is also particularly advantageous for the
dissipation of shock waves and noise.
The plastic handle which is utilized has an advantage in that if
the door on which the device is mounted becomes red hot, the handle
will melt and the device will drop to the ground and then can be
removed at a later time. Even if the device should become very hot
so that it begins to burn, it normally will not explode and will
merely be consumed.
It should be appreciated that although in the embodiment of the
invention shown in FIGS. 8-17, the device has been formed so that
linear-shaped explosive charge 101 only extends along three sides
of the opening which is to be cut, the device can be readily
modified to extend the linear-shaped explosive charge to the fourth
side. When this is the case, the device can be utilized for
permitting entry, egress or ventilation through the barriers of
masonry, wood, metal, plaster, etc. It is particularly applicable
for forming ventilation holes in roofs and the like. It can be used
for rapidly cutting such a hole in a roof merely by throwing the
device onto a roof from an aerial ladder or platform. This is
accomplished by first removing the jet defeating wire 141 and then
breaking out the weakened front panel portion 73a. The firing line
or cord 107 is then removed. Then, holding the cord 107 in one
hand, the device can be thrown onto the roof. In the event that the
device lands upside down on the roof, it can be pulled back by the
firing line and tossed onto the roof again until it lands right
side up. Once the device has been properly positioned on the roof,
the firing mechanism is attached and then the device can be
initiated in the manner hereinbefore described to rapidly cut a
hole in the roof.
In the event a situation arises in which it is impossible for a
fire fighter to get close enough to position the device, the device
can be attached to the end of an aerial ladder and then by
utilizing an extension line 131, the aerial ladder can be utilized
for positioning the device and thereafter it can be initiated by
operation of the firing mechanism to cut a hole in the roof without
any danger to the firemen.
Still another embodiment of the explosively actuated ingress and
egress device is shown in FIGS. 18-23. This embodiment also
consists of a case 161 which has a circular configuration rather
than the rectangular configuration of the case 71 in the previous
embodiment. The case 161 consists of a box 162 and a lid 163, both
of which are formed of a suitable material such as molded
polystyrene. The box is provided with a bottom wall 164 and an
annular side wall 166. A centrally disposed well 167 is formed as a
part of the box 162 by a circular upright wall 168 formed integral
with the bottom wall 164. An outer annular compartment 169 is
formed between the wall 168 and the side wall 167. A linear-shaped
explosive charge 171 is mounted in a recess 172 provided in the
outer surface of the bottom wall 164. The recess 172 is formed in a
raised portion 164a of the bottom wall. The linear-shaped explosive
charge 171 is constructed in the manner hereinbefore described and
has mounted therein a jet defeating wire 173. A face plate 174 of
fiberboard is mounted on the back surface of the bottom wall 164
and serves to hold the jet defeating wire 173 and the linear-shaped
explosive charge 171 in place. A loop 176 is formed on the end of
the wire 173 and is provided with a warning tag 177. The
linear-shaped explosive charge 171 is substantially continuous and
is in the form of a circle which generally underlies the center of
the outer compartment 169 formed in the box 162.
Means is provided for detonating the linear-shaped explosive charge
171 which is of a type that is similar to that hereinbefore
described. It consists of a blasting cap 178 which is disposed in a
recess 179 provided in gusset 181 that is formed integral with the
inner side wall 168 and the bottom wall 164. The blasting cap
extends through a hole 182 (see FIG. 2) and is in direct contact
with the linear-shaped explosive charge as shown in FIG. 20. The
blasting cap is connected to a confined detonating cord 183 which
is also disposed in the recess 179 and extends upwardly above the
well 167. A backing material 186 such as Vermiculite is disposed in
the outer annular compartment 169 and fills the same. A layer of
cardboard 187 is mounted in the box 162 flush with the top of the
wall 168 and also rests upon an annular shoulder 188 provided in
the side wall 166. This cardboard layer 187 serves to keep the
Vermiculite in place. The cord 183 extends above the cardboard
layer 187 and is looped about in a space 189 provided above the
cardboard layer 187 as shown in FIG. 23. The loops of the cord are
held in place by suitable means such as strips of masking tape 191.
The cord is provided with a fitting 192 similar to the fitting 111
and which is mounted in a slotted holder 193 mounted upon the
cardboard layer 187. The holder 193 also carries a firing mechanism
194 identical to the firing mechanism 114.
The lid 163 is cemented in place on the box 162. It is provided
with a weakened section 163a by the use of a circular V-shaped slot
167 and a pair of diametrically extending slots 197 and 198 which
form a cross to facilitate ready break-out of the weakened section.
The lid is also provided with an annular reinforcing portion 163b
which extends downwardly and, in addition, to reinforcing the
opening 199 which is formed when the weakened section 163a is
broken out, also serves as a means for registering the lid on the
box 162.
A handle 201 for carrying the device and also for hanging up the
device when it is desired to operate the same. The handle is formed
from a suitable material such as Nylon rope which extends through
holes 202 provided in reinforcing bosses 203 formed integral with
the side wall 166 and the ends of which are fastened together by
splices 204.
The device which is shown in FIGS. 18-23 is operated in much the
same manner as the embodiments hereinbefore described. It is
positioned on the wall or surface on which the opening is to be
cut. From the configuration of the linear-shaped explosive charge,
it can be seen that a circular cut is made. Typically, this device
can make a hole 12 inches in diameter. Such a hole permits
introduction of a stream of water through a masonry, plaster, metal
or wooden barrier or makes it possible to unlock a steel fire door
from the inside. Even though a small opening is made with a device
such as shown in FIGS. 18-23, this does not preclude making a
larger opening with a device of the type hereinbefore or
hereinafter described should this become necessary.
The embodiment of the device shown in FIGS. 18-23, however, does
include an additional feature which is not included as a part of
the embodiments hereinbefore described. This is the provision of
the center well 167 which is designed to receive a supplemental
explosive charge. Such a supplemental charge may be desirable where
it is necessary to form a hole in a relatively thick masonry or
concrete wall. Typically, a sheet explosive 206 is mounted in the
bottom of the well 167 after the weakened section 163a has been
removed from the lid 163 and after the cord 183 has been removed.
An extension line 207 having a blasting cap at one end and having a
percussion detonator and intermediate charge on the other end of
the type hereinbefore described is connected to the sheet explosive
206 as shown in FIG. 20. Then, the extension line 207 leads out of
the well and is placed in recess 208 provided in another gusset 209
extending radially outwardly from the wall 168. The extension line
207 then extends through an opening (not shown) similar to the
opening 182 and makes contact with the linear-shaped explosive
charge 171. Thus, it can be seen that at the time the linear-shaped
explosive charge is detonated, the extension line 207 will be
detonated to cause detonation of the sheet explosive 206 which will
cause the creation of a center point of over-pressure which will
greatly aid in cutting the hole through a thick wall of masonry or
concrete.
Still another embodiment of the explosively actuated ingress and
egress device is shown in FIGS. 25 and 26 which can be
characterized as a straight embodiment. The device 211 consists of
a housing or case 212. The housing or case 212 consists of a box
213 and a lid 214. The box has a rectangular configuration and is
provided with a bottom wall 216, spaced parallel side walls 217 and
218 and spaced parallel end walls 219 and 221 which form an
elongate compartment 222. The bottom wall is provided with a
centrally disposed raised portion 216a which extends longitudinally
of the box and which is provided with a recess which receives a
linear-shaped explosive charge 223 opening through the bottom side
of the bottom wall 216. A jet defeating wire 224 is mounted in the
open "V" of the explosive charge 223 in the manner hereinbefore
described. The wire is provided with a loop 226 which carries a tag
227. A fiberboard face plate 228 is secured to the bottom side of
the bottom wall 216 and retains the wire 224 and the linear-shaped
explosive charge 223 within the recess in the bottom wall. Backing
material 231 is provided in the compartment 222 and is of a
suitable type such as Vermiculite. The lid 214 covers the open side
of the box 213 as shown in FIGS. 25 and 26 by suitable means such
as an adhesive and seals the backing material 231 within the box.
The box 213 and lid 214, as in the previous embodiments, can be
formed from polystyrene.
Means is provided for detonating the linear-shaped explosive charge
and consists of a blasting cap 232 which is adapted to be initiated
by a confined detonating cord, both of which are disposed in a
recess provided in the bottom wall and which abut one end of the
linear-shaped explosive charge 223. A fitting 234 is provided on
the outermost end of the cord 233 and is adapted to receive a
firing mechanism 236 of the type hereinbefore described.
The device which is shown in FIGS. 25 and 26 can be manufactured in
any suitable length. For example, it may be desirable to provide
lengths of 2, 4, 6 and 8 ft. which can be utilized in combination
to enable one to cut a large, rectangular hole as, for example, a
hole 8 ft. long by 4 ft. wide, or any other size which can be cut
by using various combinations of the devices 211 shown in FIGS. 25
and 26.
Although the device which is shown in FIGS. 25 and 26 has been
shown as having a rectangular configuration, an elongate device can
also readily be manufactured by utilizing a housing or case which
has a semi-circular configuration and in which the bottom side of
the semi-circular configuration is enclosed by a lid which can
carry the linear-shaped explosive charge.
Operation and use of the device which is shown in FIGS. 25 and 26
may now be explained in connection with FIG. 24. Let it be assumed
that it is desired to cut a large hole as, for example, 8 ft. by 2
ft., in the roof of a burning building to ventilate the same. To
accomplish this, the devices 211 would normally be used in pairs.
Thus, as shown in FIG. 24, two of the devices 211 which are 8 ft.
in length would be placed on the roof of the building in spaced
parallel relationship. The firing lines or cords 233 would be
coupled into a snap coupler 237 which, in turn, would be connected
to an extension line 238 of the type hereinbefore described. A
firing mechanism 234 would then be mounted on the end of the
extension line. As soon as the operator has removed himself to a
safe distance, the firing mechanism 234 could be operated to
detonate the extension line 238 and the lines 233 to set off the
devices 211. Actuation of the two devices 211 would form two
parallel cuts extending in one direction in the roof. As soon as
this has been accomplished, two additional devices 211 which are 2
ft. in length are mounted over the ends of the cuts which have
already been made in the roof and are interconnected to a firing
mechanism 234 in the same manner that the previous pair of devices
was connected. The operator then detonates the other two devices
211 to cause two additional cuts to be made in the roof at right
angles to the cuts which have previously been made to complete
cutting the rectangle and to permit the section of the roof which
has been cut out to drop inwardly and to thereby vent the roof. In
positioning the last two devices 211, the operator must be sure
that the cuts which are to be formed by the two devices 211 will
overlap the two cuts which have previously been made so that there
will be a continuous cut all around the section of the roof which
is to be cut out so that the roof section will drop inwardly.
From the foregoing, it can be seen that a very usable assembly
consists of a pair of the straight devices 211 which have their
confined detonating cords interconnected into a single end fitting
which can be detonated by the use of a single firing mechanism.
This facilitates placing the assembly into use very rapidly merely
by taking two of the units and placing them in spaced apart
positions and then rapidly detonating the same to provide two
elongate cuts. The opening can be completed merely by utilizing
another pair of the devices to make two cuts between the two cuts
which have already been formed to complete the formation of the
opening.
In order to facilitate use of the explosively actuated ingress and
egress devices, it is desirable and almost necessary that such
devices be capable of meeting a class C designation under the
Bureau of Explosive regulations. This permits it to be shipped in
the same classification as shot gun ammunition and permits it to be
moved by common carriers. In FIGS. 27, 28 and 29, there is shown a
package assembly which is utilized for packaging the explosively
actuated ingress and egress devices so that they will meet the
class C designation described above. Two of the explosively
actuated ingress and egress devices 241 of any of the types
hereinbefore described as, for example, the type which is shown in
FIGS. 8-17 are packaged as a unit as shown in FIGS. 27 and 28. Each
of the devices 241 is packaged in its own shipping container or box
242. Each box 242 consists of a bottom section 243 and a top
section 244. Each section is provided with a bottom wall and
upstanding side walls and are arranged so that they telescope
within each other as shown in FIG. 28. A shock absorbing pad 246
formed of a suitable material such as polystyrene having a density
of approximately 1 lb. per cubic foot and one-half inch in
thickness is provided within the box 242 adjacent the bottom or
cutting side of the device 241. It will be noted that with the pad
in place, the side walls of the two sections 243 and 244 overlap
substantially throughout the entire lengths. The two sections 243
and 244 are fastened together in a suitable manner such as by
gummed craft paper 247.
After the devices 241 have been packaged in the corrugated boxes or
containers 242, the two boxes 242 are stacked one above the other
in such a manner so that the bottom sides or the cutting sides of
the two devices 241 face each other. In other words, the cutting
sides of the devices 241 are in juxtaposition. It should be
appreciated that the devices 241 are packaged with their jet
defeating wires in place so that one device 241 will not be
initiated sympathetically in the event of inadvertent detonation of
the other device.
The two boxes 242 are placed in a large outer third box or shipping
container 251 which is also formed of two sections 252 and 253
which are provided with a bottom wall and upstanding sidewalls and
which are formed so that they telescope within each other as shown
in FIG. 28. Again, the side walls of the sections 252 and 253
overlap throughout substantially all portions thereof. The two
sections 252 and 253 are fastened together by suitable means such
as a filament tape 254.
The boxes 242 and the box 251 are formed of fiberboard which meets
an ICC approved classification 12H for containers.
The packaging which is shown in FIGS. 27 and 28 has been found to
be capable of providing adequate protection so that in the event of
inadvertent detonation of one of the devices, severe damage will
not result to adjacent structures. Lethal fragments are not created
because of the construction of the devices themselves as
hereinbefore pointed out and also because of the packaging material
which is utilized for packaging the devices for shipment. The
fiberboard construction of the boxes also serves to provide a
substantial fragment-shielding function. In tests, it was found
that even if the devices were thrown into a fire, they would not
explode but only burn. Driving heavy trucks over the same would not
cause them to explode. Similarly, firing rifle bullets into the
same or dropping the same would not cause them to explode. Also,
the device can withstand relatively high temperatures before
burning. Thus, it can be utilized on any surface which is
800.degree. F. or less. Even at the highest temperature it will not
begin to burn for several minutes which is more than ample time to
position and fire the device.
In packaging the straight device which is shown in FIGS. 25 and 26,
the devices can be packaged in a similar manner with the cutting
faces in juxtaposition to each other. It can be seen that if the
straight devices are semi-circular in cross-section, that two of
them can be readily combined and shipped in a circular tube which
would be very convenient.
In all the embodiments it can be seen that the backing material is
faced directly in the compartment behind the linear-shaped
explosive charge. Alternatively, if desired, the backing material
can be placed in elongate plastic bags and then the bags placed in
the compartment. This has the advantage in that the bags will
confine the backing material and will prevent it from spreading
throughout the device. This will be particularly advantageous
during the construction of the devices.
It is apparent from the foregoing that there has been provided an
explosively actuated device which can be readily and rapidly used
for obtaining either egress from or ingress into a building. This
is particularly advantageous for fire fighting and other emergency
situations. The device is relatively simple and economical in
construction and can be operated by relatively unskilled
personnel.
The device is one which can have a number of configurations and
thus is very versatile for cutting any size and type of hole. It
can be utilized in many dangerous locations without danger to the
personnel utilizing the same. Because of its many features, the
device can be characterized as a forceable entry tool.
* * * * *