U.S. patent number 3,800,715 [Application Number 05/336,612] was granted by the patent office on 1974-04-02 for bomb recovery and shield apparatus.
Invention is credited to William A. Boller.
United States Patent |
3,800,715 |
Boller |
April 2, 1974 |
**Please see images for:
( Certificate of Correction ) ** |
BOMB RECOVERY AND SHIELD APPARATUS
Abstract
Bomb recovery and shield apparatus includes a cage shaped to
slip over a bomb, and a clip in the cage adapted to engage the bomb
and retain it inside the cage. A lead line attached to the cage is
used to pull the bomb into an explosion-resistant, open-ended
tubular shell. A lid having a shrapnel-capturing wire rope screen
covers the top opening of the shell. A post extending above the top
opening of the shell supports a pulley, and the lead line is reeved
over the pulley prior to its attachment to the cage. A workman
standing a safe distance from the bomb pulls the lead line to slip
the cage over the bomb and thereafter guides the bomb toward the
shell. The bomb is guided into the opening at the bottom of the
shell by a guide system in the shell which includes a second pulley
attached to a ring and detent pin releasably supported in the
bottom of the shell. The lead line passes through the interior of
the shell and is reeved over the second pulley. A fixed lead rod
extends lengthwise through the interior of the shell, and the ring
of the detent pin is disposed around the lead rod. The bomb and
cage are drawn into the open bottom of the shell, and continued
pulling on the lead line causes the detent pin and ring to release
from their support and slide lengthwise upwardly along the guide
rod, thereby allowing the bomb to be guided safely along the guide
rod into the interior of the shell.
Inventors: |
Boller; William A. (Mountain
View, CA) |
Family
ID: |
26881022 |
Appl.
No.: |
05/336,612 |
Filed: |
February 28, 1973 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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185301 |
Sep 30, 1971 |
3721201 |
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Current U.S.
Class: |
109/49.5; 86/50;
109/1R; 89/36.01 |
Current CPC
Class: |
F42D
5/045 (20130101); F42B 33/067 (20130101); F42B
39/14 (20130101) |
Current International
Class: |
F42B
39/00 (20060101); F42D 5/00 (20060101); F42B
39/14 (20060101); F42D 5/045 (20060101); E06b
009/00 (); E05g 003/00 () |
Field of
Search: |
;109/49.5,58.5,58,49,85,1R ;102/22 ;89/36R,36D,1R ;214/1D
;294/67DA,67C,67D,67DB,67E,92,93,75H ;86/1 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
"This Week Magazine Section" of The Sunday Star, Aug. 12, 1951,
Washington, D.C..
|
Primary Examiner: Taylor; Dennis L.
Attorney, Agent or Firm: Christie, Parker & Hale
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATION
This is a continuation-in-part of my copending application Ser. No.
185,301, filed Sept. 30, 1971, now U.S. Pat. No. 3,721,201.
Claims
I claim:
1. Apparatus for moving a bomb and shielding its explosion, the
apparatus comprising a shell having an explosion-resistant body
with a hollow interior and at least one open end, a cage shaped to
fit around the bomb and adapted to retain the bomb inside it, and a
guide system for moving the cage around the bomb and providing
guided movement of the cage and the bomb through the open end of
the shell to its interior, the guide system including an elongated
tension line secured to the cage, an elongated guide rod in the
interior of the shell, and a guide attached to the guide rod and
coupled with the tension line, the tension line extending to a
point remote from the shell from where it can be shortened to draw
the bomb and cage toward the shell, the tension line cooperating
with the guide and guide rod to provide guided movement of the bomb
safely through the open end of the shell into the interior of the
shell so that the bomb and cage can be led into the shell without
substantial contact between the cage or bomb and the shell.
2. Apparatus according to claim 1 in which the guide rod is held in
a fixed position in the shell, and in which the tension line is
reeved over a sheave engaged by the guide rod.
3. Apparatus according to claim 2 in which the sheave is slidably
engaged with the guide rod.
4. Apparatus according to claim 3 in which the sheave is releasably
mounted adjacent the open end of the shell, the sheave being
attached to a ring which is slidably disposed on the guide rod.
5. Apparatus according to claim 2 in which the shell is a
substantially tubular body having an open top and an open bottom,
and in which the tension line extends through the open top of the
shell, lengthwise through the interior of the shell, and out the
open bottom of the shell for attachment to the cage, and in which
the sheave is engaged with the guide rod at a point near the open
bottom of the shell so that the bomb and cage can be led through
the open bottom of the shell via the tension line without
substantial contact between the cage or bomb and the shell.
6. Apparatus according to claim 5 in which the sheave is slidably
engaged with the guide rod.
7. Apparatus according to claim 6 in which the sheave is releasably
mounted adjacent the open end of the shell, the sheave being
attached to a ring which is slidably disposed on the guide rod.
8. Apparatus according to claim 7 including a second sheave
disposed near the open top of the shell for providing guided
movement of the tension line during use.
9. Apparatus according to claim 1 including attachment means fixed
to a point exterior of the shell for releasably securing the
tension line in a fixed position relative to the shell.
10. Apparatus according to claim 6 in which the guide rod extends
from a point adjacent the bottom inner wall of the shell upwardly
and inwardly toward the longitudinal axis of the shell.
11. Apparatus according to claim 5 including an open mesh wire rope
screen covering the open top of the shell.
12. A bomb shield comprising a shell having an explosion-resistant
exterior wall and a hollow interior, means forming an opening into
the hollow interior, means providing a gas escape path from the
hollow interior to the exterior of the shell, and a guide system in
the shell for providing guided movement of an explosive device
through the opening of the shell to its interior, the guide system
including an elongated tension line secured to a device for
retrieving the explosive device, an elongated guide rod in the
interior of the shell, and a guide attached to the guide rod and
coupled with the tension line, the tension line extending to a
point remote from the shell from where it can be shortened to draw
the explosive device toward the shell, the tension line cooperating
with the guide and guide rod to provide guided movement of the bomb
safely through the open end of the shell into the interior of the
shell without substantial contact between the explosive device and
the shell.
13. Apparatus according to claim 12 in which the guide rod is held
in a fixed position in the shell, and in which the tension line is
reeved over a sheave engaged with the guide rod.
14. Apparatus according to claim 13 in which the sheave is slidably
engaged with the guide rod.
15. Apparatus according to claim 14 in which the sheave is
releasably mounted adjacent the open end of the shell, the sheave
being attached to a ring which is slidably disposed on the guide
rod.
16. Apparatus according to claim 13 in which the shell is a
substantially tubular body having an open top and an open bottom,
and in which the tension line extends through the open top of the
shell, lengthwise through the interior of the shell, and out the
open bottom of the shell for attachment to the device for
retrieving the explosive, and in which the sheave is engaged with
the guide rod at a point near the open bottom of the shell so that
the explosive can be led through the open bottom of the shell via
the tension line without substantial contact between the explosive
and the shell.
17. Apparatus according to claim 16 in which the sheave is slidably
engaged with the guide rod.
18. Apparatus according to claim 17 in which the sheave is
releasably mounted adjacent the open end of the shell, the sheave
being attached to a ring which is slidably disposed on the guide
rod.
19. Apparatus according to claim 18 including a second sheave
disposed near the open top of the shell for providing guided
movement of the tension line during use.
20. Apparatus according to claim 12 including attachment means
fixed to a point exterior of the shell for releasably securing the
tension line in a fixed position relative to the shell.
21. Apparatus according to claim 17 in which the guide rod extends
from a point adjacent the bottom inner wall of the shell upwardly
and inwardly toward the longitudinal axis of the shell.
22. Apparatus according to claim 16 including an open mesh wire
rope screen covering the open top of the shell.
Description
BACKGROUND OF THE INVENTION
The invention relates to public safety equipment, and more
particularly to a remote-controlled system for moving a bomb to the
inside of an explosion-proof shield that prevents serious injury if
the bomb subsequently explodes.
The recent increase in militant bombings has made it necessary to
develop devices for aiding policemen, firemen, and the like in
recovering potentially explosive bombs and removing them in such a
way that serious injury does not occur if the bomb explodes.
Generally speaking, most militant pipe bombs are "low-order"
explosives in which an explosion propels deadly shrapnel in a
multiplicity of directions at supersonic velocities. In
"high-order" explosives, the explosion occurs with such force that
the pipe is virtually annihilated, creating essentially no shrapnel
of any substantial mass. However, the pressure and temperature
generated within the pipe by a high-order explosive can approach
3,000,000 psi at 2,000.degree.K. The persons responsible for
removing a bomb must always assume that the bomb may be activated
without warning by a timer, or set off by a triggering device, such
as a mercury switch, in response to slight movement of the bomb.
Thus, extreme care must be used in handling all bombs.
The prior art systems for handling potentially explosive bombs
unfortunately require the workman to be dangerously close to the
bomb, and usually require him to make physical contact with the
bomb. In some prior art procedures, the operator works from behind
a protective shield stationed relatively close to the bomb. The
inherent danger in this procedure is the strong chance the operator
will be struck by shrapnel ricocheting around or even penetrating
the shield if the bomb explodes. Worse still is the danger that the
percussion from the shock wave of detonation will injure or kill
him despite the shield because of this proximity (usually within 15
or 20 feet) to the uncovered bomb.
SUMMARY OF THE INVENTION
This invention provides a remote controlled system for the safe
handling and disposal of militant bombs.
Briefly, the invention includes a shell having an
explosion-resistant body, and an explosive-capturing cage shaped to
slip over the bomb and adapted to retain the bomb inside it. Guide
means secured to the cage are controlled to slip the cage over the
bomb to pick it up and provide guided movement of the bomb to the
interior of the shell for safe disposal. Preferably, the interior
of the shell is large enough to provide an air insulation gap (at
least two to three times the diameter of the bomb) between the bomb
and the inner wall of the shell.
In a preferred form of the invention, an elongated post is secured
to the body of the shell. The guide means includes an elongated
line having one end secured to the cage, and a pulley secured to a
portion of the post supported above the open end of the shell. The
lead line is reeved over the pulley, with its other end extending
to a point remote from the shell and cage. Thus, the operator can
handle the bomb from a safe distance by pulling on the line to slip
the cage over the bomb and guide the cage and bomb in one
continuous and quick motion to the inside of the shell.
In one form of the invention, the top opening of the shell is
covered by a shrapnel-capturing open mesh wire rope screen to allow
the escape of gas if an explosion occurs. In another form, the lid
can be suitably spaced from the top of the shell to provide an
adequate gas escape.
Preferably, the bomb is guided into an open bottom of the shell by
guide apparatus in the shell including a second pulley attached to
a ring and detent pin supported inside the shell adjacent its
bottom opening. The lead line passes through the interior of the
shell and is reeved over the second pulley prior to its attachment
to the explosive-capturing cage. A fixed lead rod extends
lengthwise through the interior of the shell, and the detent pin
ring is disposed around the lead rod. In use, the lead line is
pulled to move the bomb and cage into the open bottom of the shell
until the end of the lead line engages the second pulley. Continued
pulling of the lead line thereafter releases the ring and detent
pin from their support, and allows the ring to slide lengthwise
upwardly along the guide rod. The bomb and cage follow the ring and
are thereby guided safely into the interior of the shell.
BRIEF DESCRIPTION OF THE DRAWINGS
These and other aspects of the invention will be more fully
understood by referring to the following detailed description and
the accompanying drawings in which:
FIG. 1 is an elevation view showing a tubular bomb shield;
FIG. 2 is a perspective view showing a bomb pickup device for
slipping over a bomb and moving it to the inside of the bomb
shield;
FIG. 3 is a perspective view showing a wheel cart for carrying the
bomb shield;
FIG. 4 is a perspective view showing the bomb recovery and shield
apparatus in use recovering a bomb;
FIG. 5 is a fragmentary sectional perspective view showing an
alternate embodiment of the tubular bomb shield;
FIG. 6 is a fragmentary sectional elevation view showing an
alternate embodiment of the lid covering the bomb shield;
FIG. 7 is an exploded elevation view showing a system for guiding
the bomb into the interior of the bomb shield;
FIG. 8 is a plan elevation view taken on line 8--8 of FIG. 7;
and
FIG. 9 is an enlarged elevation view of the apparatus shown within
the circle 9 of FIG. 7.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Referring to FIG. 1, a bomb shield or "blast tube" 10 includes a
tubular, open-ended shell 12. Preferably, the shell has relatively
thick walls made of a rigid, high strength material such as steel.
The shell ideally has walls which are about 11/2 inches thick so
the shell is capable of withstanding explosions caused by low order
and propellant explosives and common high order explosives.
Preferably, the shell is made from a gun barrel casing having an
interior large enough to enclose the type of pipe bombs which are
commonly encountered during use.
During normal use, the shell stands upright on feet 14 secured to
the bottom angular lip of the shell by suitable means such as
welding. Outwardly projecting cylindrical handles 16 are welded to
opposite sides of the shell outer wall.
An elongated upright post 18 is welded to the upper annular lip of
the shell. The top of the post carries an outwardly extending,
horizontal boom 20 projecting over the hollow interior of the
shell. Preferably, the boom is located about 21/2 feet above the
top of the shell. The boom supports a downwardly extending eye 22
positioned centrally over the hollow interior of the shell.
A lid 24 is mounted to pivot about a point on the upper lip of the
shell. Lid 24 includes a ring-shaped metal body 25 having a size
matching that of the tubular shell. The opening in the lid is
covered by an open mesh screen 26 preferably made of woven wire
rope. The end portions of the wire ropes extend through separate
holes (not shown) drilled through the lid and project below an
annular shoulder 27 formed in the inner periphery of the bottom
annular lip of the lid. Each end of the wire rope is swaged below
shoulder 27 to firmly hold the wire ropes in place. The wire ropes
are shaped and interwoven to form the hemispherical open mesh
netting illustrated best in FIG. 1.
A similar hemispherical shaped open mesh netting 28 made of woven
wire rope covers the opening at the bottom of the shell. The ends
of the bottom wire ropes extend through holes (not shown) drilled
through an annular lip 29 extending inwardly into the interior of
the shell at its bottom. The ends of the wire rope below shoulder
27 are swaged to hold the wire ropes in place.
A bore 30 extends through the body of the lid, with a narrowed
lower portion 31 of post 18 extending up through bore 30 so the lid
pivots from an open position shown in FIG. 1 to a closed position
covering the opening at the top of the shell. The narrowed part of
the post forms a shoulder immediately above the upper lip of the
lid to prevent the lid from sliding axially on the post.
A spacer 32 between the upper lip of the shell and the bottom of
the lid provides a narrow annular space between the lid and the top
of the shell when the lid is closed. The purpose of this space will
be described in detail below. A downwardly projecting lug 34 on the
side of the lid opposite its pivotal connection acts as a support
for the opposite side of the lid when it is closed.
A pair of upwardly projecting steel locking dogs 36 are welded to
opposite sides of the shell outer surface so as to extend above the
upper lip of the shell. Preferably, dogs 36 are spaced 120.degree.
apart with one being 30.degree. from post 18. Each dog has a
respective shoulder 38 projecting inwardly toward the opening in
the shell and positioned so that the lid makes a relatively tight
friction fit under the dogs when the lid is closed.
A third steel locking dog 39 welded to the outer surface of the lid
projects downwardly below the lid. Locking dog 39 has an inwardly
projecting shoulder 40. When the lid is closed shoulder 40 makes a
sliding fit in a notch 42 formed in the outer surface of the shell.
Preferably, notch 42 is spaced 120.degree. from each steel dog 36,
so that the lid is locked at three equidistantly spaced points when
closed.
An upwardly projecting eye 44 is welded to the upper annular lip of
lid 24. The purpose of the eye will be described in detail
below.
FIG. 2 shows a bomb pickup device or cage 46 for use in conjunction
with blast tube 10. Pickup device 46 comprises a skeleton framework
which includes a U-shaped base frame 48. The ends of several
longitudinally spaced apart, downwardly opening hoop segments 50
are secured to the parallel legs of base frame 48, one hoop segment
being secured to the open end of the U, and a pair of other hoop
segments being secured to intermediate portions of the U. An
inverted V-shaped end piece 51 is secured above the cross-piece of
the U at the other end. A longitudinally extending bar 52 is
rigidly fixed to the tops of the hoop sections and the apex of the
end piece. A relatively stiff elongated steel leaf spring or bomb
retainer clip 56 secured to the underside of the hoop segment above
the open end of the U projects downwardly and rearwardly into the
interior portion of the pickup device.
Alternatively, the skeleton framework may be modified in a suitable
manner to support an open-ended bag (not shown) or other similar
receptacle for slipping over the bomb.
The use of the blast tube 10 and bomb pickup device 46 is best
understood by referring to FIGS. 3 and 4. Blast tube 10 preferably
is transported to the site of the bomb on a wheel cart 58. The
wheels of the wheel cart preferably are those from a motorcycle,
and include hand brakes (not shown) for controlling movement of the
cart so that one man can operate it. The blast tube hangs in the
wheel cart by handles 16 which rest in upwardly opening stirrups or
gimbal hangers 60 secured to the sides of the cart frame. The wheel
cart has an elongated handle (not shown) secured to a rear
cross-piece 62 of the frame for wheeling the blast tube to the bomb
site. The handle also may have an extension (not shown) adapted for
towing the wheel cart behind a vehicle. Other equipment for
removing the bomb (to be described in detail below), together with
bomb pickup device 46, may be carried in hand by a workman or
secured by suitable means to the wheel cart frame.
A bomb 64 is approached by a workman (not shown), usually wearing a
conventional protective suit. The workman pushes the wheel cart to
a point close to the bomb, say ten to fifteen feet from the bomb.
The wheel cart is tipped forward, using its handle, to release the
blast tube from engagement with gimbal hangers 60 to set the blast
tube on the ground adjacent to the bomb. (Alternatively, the blast
tube can remain on the cart during use. This mode of operation will
be described in further detail below.)
After the blast tube is placed adjacent to the bomb, lid 24 is
pivoted to its fully open position illustrated in FIG. 4. An
elongated bomb position control tension line 66 passing through a
swivel pulley 68 is releasably secured to the pickup device,
preferably by a clip 69 at the end of the line attached to another
line 70 which forms a yoke for attachment to the pickup device. The
yoke has snap ring fasteners 72 to releasably clip tension line 66
to the pickup device. Swivel pulley 68 is releasably clipped by
suitable fastening means to eye 22 on the boom of post 18, so that
tension line 66 extends from the pickup device, through the pulley,
to a point remote from the bomb site. A lid position control
tension line 74 is releasably secured to eye 44 on the lid by a
snap ring fastener 76 fitted through the eye.
Tension lines 66 and 74 are preferably 150 feet to 200 feet long,
and each line is wound on a separate spool (not shown) or the like
to facilitate ease of handling during the preliminary stages of the
bomb recovery. Both tension lines are then strung out to a safe
position. Alternatively, the lines are played out ahead of time
from the remote position, preferably by a second workman, as the
other workman wheels cart 58 to the bomb recovery site. This latter
method is quick and substantially prevents the chance of pulling
line 66 too soon while unwinding.
Bomb pickup device 46 is placed on the ground adjacent to the bomb,
on the side of the bomb opposite the blast tube, with the
longitudinal axis of the pickup device being aligned approximately
with that of the bomb. The size of the pickup device is such that
the lateral distance between the longitudinal legs of base frame 48
is less than the diameter of the bomb. Thus, when tension line 66
is pulled, the pickup device slips over the bomb, with the
longitudinal legs of the base frame being closely spaced from the
adjacent sides of the bomb.
The bomb pickup device initially can be placed next to the bomb by
the workman in charge of the bomb recovery. However, if there is a
likelihood that the bomb contains a timing device, which makes
approaching the bomb extremely dangerous, the pickup device may be
placed on the ground at a safe distance from the bomb. Thereafter,
tension line 66 can be pulled, while standing in another safe
position, to guide the bomb pickup device over the bomb.
Alternatively, device 46 can be placed over bomb 64 by hand without
disturbing the bomb.
As the tension line 66 is guided to pull the pickup device over the
bomb, spring steel clip 56 is urged upwardly from its original
position (shown in phantom line in FIG. 4) by its contact with the
bomb. Thus, the clip exerts a downward force on the top of the bomb
to retain the bomb within the pickup device. After the bomb is
inside the pickup device, tension line 66 is pulled to immediately
move the bomb from its position on the ground to the edge of the
blast tube, then being raised to a position (not shown) hanging
directly above the opening to the blast tube. At this point, clip
69 at the end of the tension line engages pulley 68 and thereby
acts as a stop to limit further pulling of the tension line. (A
scoop device (not shown) may be used in conjunction with the blast
tube to aid guiding the pickup device up the side of the tube.) The
operator then slackens tension line 66 to lower the bomb into the
blast tube.
During movement of the bomb, end piece 51 prevents the bomb from
slipping out the end of the pickup device. The bomb will not slide
out the opposite end of the device because the cap of the bomb
catches on the end of spring clip 56, and the longitudinal legs of
base frame 48 are spaced sufficiently close to each other to
prevent the bomb from slipping out the bottom of the pickup
device.
As shown in FIG. 4, an upwardly opening cloth bag 78 or other
similar receptacle may be hung in the upper portion of blast tube
10 to receive the bomb and hold it in the center of the blast tube
so as to maintain an air insulation gap between the bomb and the
inner wall of the tube. Preferably, the blast tube is of a size
that provides an air gap of at least two to three times the
diameter of the bomb. Bag 78 may be secured to the blast tube by
various suitable means, such as screws 79, which releasably attach
the top of the bag to the upper lip of the tube.
When the bomb is safely inside the tube, the operator pulls on
tension line 74 to pivot the lid to its closed position under the
locking dogs. Locking dogs 39 on the lid acts as a stop by abutting
against the side of the blast tube as its lower shoulder engages
notch 42. This indicates to the operator that the lid of the blast
tube is completely closed. The space between the lid and upper lip
of the blast tube allows line 66 to remain attached to the bomb
when the lid is closed. Thus, line 66 may be used later to aid in
removing the bomb from the shell.
Thus, with the bomb safely inside the blast tube, the operator can
approach the blast tube with substantially reduced risk of injury.
Flying shrapnel from an explosion of a propellant or low-order
explosive will be retained inside the tube by wire rope top 26 and
bottom 28. High pressure gas resulting from an explosion is
controlled because it vents through the open mesh top and bottom.
In an explosion caused by a high-order explosive, the open mesh top
and bottom allow controlled ventilation of resultant gaseous
particles. The upper portion of the wire rope top and bottom
usually will separate by severing during such an explosion, but
tests have shown that the swaged end portions of the wire rope
maintain a secure connection to the lid and bottom of the blast
tube. Since the wire rope remains intact with the tube, it does not
create shrapnel, and in any event, even if separated from the top,
it has no substantial mass, shape, or direction to inflict much
injury, if any. The wire rope members that become severed are
easily replaced by interweaving new ones with the remaining
members. The spherical configuration of the top and bottom makes
replacement of the wire rope members a relatively easy task.
After the bomb is disposed in the blast tube, the wheel cart may be
used to pick up the blast tube and transport the bomb away from the
recovery site.
It is recognized that certain modifications of the above-described
bomb recovery and shield apparatus may be made without departing
from the scope of the invention. For example, the blast tube may be
modified in such a way that the pickup device and bomb are drawn
through the opening at the bottom of the tube. In this instance,
the feet 14 and wire rope screen 28 at the bottom of the tube are
modified to swing open together to allow bottom access and remote
closing capability. The post 18 can be shortened so that swivel
pulley 68 is positioned immediately above the opening at the top of
the tube, with the lid being bolted in its closed position. Thus,
lid position control tension line 74 may be eliminated from the top
but used on the bottom.
In using this modification of the blast tube, the operator pushes
the wheel cart and blast tube to a position close to the bomb. The
blast tube remains mounted on the cart, with the cart being
positioned so that the bottom of the blast tube is spaced
sufficiently above the ground to provide clearance for pulling the
pickup device through the opening in the bottom of the tube. After
the wheel cart and blast tube are properly positioned, the pickup
device and tension line 66 are extended down through the hollow
interior of the tube and out the bottom of the tube. After the
pickup device is aligned properly with the bomb, the operator pulls
on tension line 66 to slip the cage over the bomb and engage spring
clip 56 with the bomb. Thereafter, as the tension line is pulled
the bomb is drawn into the open bottom of the blast tube to a
position safely inside the tube. Line 74 is used to close the
bottom lid. The bomb can be lowered to rest on the bottom lid, or
the tension line may be secured to post 18, boom 20, or to a
suitable place on the cart, or the handle of the cart. This will
hold the bomb inside the blast tube as it is transported by the
wheel cart from the recovery site.
Various modifications of the post and boom also may be developed
without departing from the scope of the invention. For example, the
post or boom may be rotatable to allow the bomb to be picked up
clear of the blast tube, with continued pulling of the tension line
rotating the post or boom against a stop (not shown) to position
the bomb directly over the opening in the blast tube. Another
possible modification of the post and boom to accomplish the same
function would be a telescoping boom (not shown) with the tension
line being pulled along the longitudinal axis of the boom.
FIG. 5 shows a modified blast tube 80 which includes a metal
tubular inner shell 82 disposed concentrically inside a metal
tubular outer shell 84, with an annular void 86 being formed
between the inner and outer shells. An upper perforated ring 88 is
rigidly secured to the upper edges of the inner and outer shells so
as to cover the top of the annular void. Similarly, a lower
perforated ring 90 is rigidly secured to the bottom edges of the
inner and outer shells to cover the bottom of the annular void.
One of the purposes of blast tube 80 is to provide a device capable
of shielding the blast from a high-order explosive, while reducing
the overall weight of the device sufficiently so it can be more
easily handled by a single workman. Preferably, the wall thickness
of inner tubular shell 82 is about one inch, and the wall thickness
of outer tubular shell 84 is about 1/4 inch. Both shells preferably
are constructed of steel, the preferred source of the shells being
standard oil well drill casing. Blast tube 80 provides about a 25
lbs. to 50 lbs. reduction in weight when compared with a blast tube
having a wall thickness of from 11/2 inches to 2 inches.
Annular void 86 is filled with an energy-absorbing medium, such as
water (as shown in FIG. 5). Because of the reduced wall thickness
of the blast tube, the energy-absorbing medium is used to dissipate
energy escaping through the wall of the inner shell from an
explosion in the blast tube. Separate corks 92 are releasably
disposed in the perforations of upper and lower rings 88 and 90 to
contain the energy-absorbing medium within the annular void. In the
event a substantial amount of energy is absorbed by the water
during an explosion, the corks will separate from their respective
perforations to provide further means for dissipating the
energy.
The annular void may be filled with a variety of energy-absorbing
media, such as plastic foam, expanded metal such as honeycomb
metal, balsa wood, sand, and the like.
The interior surface of the inner shell 82 is lined with a
removable layer of insulation 94, which also covers and seals the
bottom opening of the inner shell. During use of blast tube 80, a
source of liquid nitrogen (shown schematically at 96) is delivered
to the bomb site. After the bomb is moved to the inside of the
blast tube, the interior of the tube is filled with liquid nitrogen
by a pump 97 which forces the liquid nitrogen through a line 98
leading from liquid nitrogen source 96, at a point remote from the
bomb, to the interior of the blast tube. The purpose of the liquid
nitrogen is to freeze the bomb to deactivate the explosive material
contained in it. Moreover, if the bomb is activated by a triggering
device powered by batteries, for example, the liquid nitrogen
freezes all chemical activity in the batteries and thereby prevents
the bomb from being activated.
Other temperature-reducing media may be used in place of the liquid
nitrogen, but liquid nitrogen is preferred because of its
relatively low cost, chemical stability, and effectiveness in
deactivating explosives. Preferably, insulation 94 is a foam
insulation material, such as polystyrene. The purpose of the
insulation is to prevent the steel inner shell 82 from contacting
the liquid nitrogen which could lower the temperature of the steel
sufficiently to make it brittle and thereby reduce its
explosion-resistant characteristics. The insulation also reduces
evaporation of the liquid nitrogen. Other insulation materials may
be used, without departing from the scope of the invention, as long
as they are capable of providing a good temperature insulation
barrier between the interior of the blast tube and inner shell
82.
In the event a bomb is heavily insulated, the freezing process may
not be effective to deactivate the bomb. However, the presence of
the blast tube itself obviously will prevent serious injury in the
event the bomb explodes.
FIG. 6 shows a modified form of the blast tube in which the opening
at the top of the tube is covered with a downwardly opening
oversized metal lid 100. The lid has a bottom annular rim 102 which
is spaced laterally from the side of the blast tube, the underside
of the lid being spaced from the top of the blast tube by vertical
support legs 104 resting on the upper lip of the tube. The lid
swings to the side by means of a suitable hinge 106 at its side.
The blast tube also has an identical hinged lid 108 at the bottom,
the hinge at the bottom allowing lid 108 to open in the event the
bomb is drawn through the bottom of the tube. Both lids provide an
escape path for venting gas, as represented by the arrows in FIG.
6.
In using the blast tube of FIG. 6, lid 100 swings open by means of
a remote controlled tension line (not shown) such as line 74, so
that recovered bomb may be loaded through the top of the blast
tube. To allow loading through the bottom of the tube, lid 100
includes an opening 110 in its top through which line 66 passes.
Each lid includes suitable remote controllable locking means (not
shown), such as locking dog 39 and notch 42, located on the side of
the tube opposite the hinge.
FIGS. 7 through 9 illustrate a system for safely guiding the bomb
and pickup cage into the interior of the shell. This system
includes an alternate shell or blast tube 112 having an open top
and bottom, and an annular top 114 and open mesh wire rope screen
116 similar to lid 24 attached by bolts 117 in a fixed position
over the open top of the shell. The bottom of the blast tube
remains open.
The bottom of the shell includes a pair of fixed legs 118 and an
adjustable leg 120 having a tilt bolt 122. During use, the blast
tube 112 is transported to the bomb site on wheel cart 58 (shown in
FIG. 3), and prior to capturing the bomb the handle of the cart is
placed on the ground to elevate and tip the bottom of the blast
tube. Alternatively, the tube can be placed on the ground and the
tilt bolt 122 may be adjusted to fix the blast tube in its desired
orientation.
The shrapnel-capturing top 114 has a pair of circumferentially
spaced apart, upwardly extending fixed legs 124, and a pulley post
126 also acting as a leg. It will be shown below that the bomb
preferably is drawn into the open bottom of the blast tube during
use. However, should the operator determine that a suspect device
may be safely picked up physically, he can invert the blast tube to
allow for an open top configuration. This procedure is accomplished
preferably by setting the tube off cart 58 and inverting the tube,
using legs 124 and 126 as handles.
The bomb and cage are led into the interior of blast tube 112 by a
guide system which includes a pulley 128 attached to pulley post
126 above the top of the blast tube, and a bottom pulley 130 inside
the tube adjacent its bottom opening. The bottom pulley is attached
to a ring 132 which, in turn, is fastened to an upright detent pin
134 releasably secured to the top of a support 136 fixed to the
bottom annular lip of the blast tube and projecting inwardly toward
the center of the blast tube. The bottom pulley and its support are
located on the side of the blast tube immediately opposite top
pulley 128. This configuration is illustrated best in FIG. 8 which
shows the top pulley located 180.degree. from the position of the
bottom pulley.
Lead line 66 is reeved over top pulley 128, and then passes through
the wire mesh screen, and lengthwise through the interior of the
blast tube, prior to being reeved over the bottom pulley 130. The
end of the tension line carries a clip (not shown). A yoke (not
shown) attached to cage 46 is fixed to the clip.
An elongated guide rod 138 bent into a slight S-shaped
configuration extends lengthwise through the interior of the tube.
The top of the guide rod if fixed to pulley post 126, and the
bottom of the guide rod is threaded through ring 132 prior to being
attached to support 136.
In using the guide system, the lead line is pulled to draw the bomb
and cage slowly into the open bottom of the blast tube until the
line offers resistance when the clip at the end of the line engages
bottom pulley 130. Continued pulling of the lead line releases
detent pin 134 from its attachment to support 136. Thereafter, the
bomb may be guided safely into the interior of the blast tube via
ring 132 which is free to slide lengthwise upwardly along guide rod
138. The guide system thus allows the bomb and cage to enter the
blast tube through the bottom opening thereof, while preventing the
bomb or cage from striking the blast tube, which could otherwise
jar the bomb sufficiently to cause it to explode, or catch on the
bottom of tube 112.
Once the bomb and cage are safely inside the blast tube, lead line
66 can be secured by means of an attachment 140 to the blast tube
shown best in FIG. 9. The attachment includes a horizontally
disposed support base 142 attached to the top of a bracket 144, the
bottom of which is fixed to the annular rim of top 114. Bracket 144
projects radially outwardly and upwardly from the blast tube to
hold the support base in a remote position above top 114.
A cam-action jam cleat 146 is secured to the top of base 142. The
base also supports a guide 148 through which lead line 66 is
threaded prior to entering the top of the blast tube.
In using attachment 140, once the bomb is safely inside the blast
tube, the operator walks slowly toward the blast tube holding the
lead line taut until the lead line can be locked by an in-and-down
motion in jam cleat 146.
The bomb is then ready to be transported to a bomb disposal site by
wheel cart 58. At the disposal site, the lead line may be remotely
released from the jam cleat. The explosive-capturing device then is
lowered as far as possible, and the cart either driven, walked
away, or pulled away by means of another long rope, leaving the
explosive-capturing device on the ground. The operator then
approaches the device. There is a drawstring at the back of the bag
which encloses the capturing device. The drawstring is loosened to
allow the operator to open the rear of the bag. The
explosive-capturing device then is jerked from the bomb by the line
at a safe distance from the bomb. This movement leaves the suspect
bomb exposed.
Thus, the bomb recovery and shield apparatus of this invention
provides the following advantages:
1. The operator of the apparatus does not come into contact with
the bomb;
2. There is only a short time lag from the time the bomb is moved
to the time the bomb is safely inside the blast tube;
3. The movement of the bomb into the blast tube is done remotely;
and
4. The entire bomb recovery system may be operated by one
person.
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