U.S. patent number 3,799,287 [Application Number 05/344,436] was granted by the patent office on 1974-03-26 for emergency descent apparatus.
Invention is credited to Albert C. Ledner.
United States Patent |
3,799,287 |
Ledner |
March 26, 1974 |
EMERGENCY DESCENT APPARATUS
Abstract
A device useful for descending from an elevated location along a
strand of webbing or similar material is disclosed, which includes
a housing containing a tortuous path through which the strand is
drawn as the housing moves downward on the strand. Means for
controlling the rate of descent are included, and a novel handle
arrangement permits immediate reuse of the device without having to
draw the strand back through the housing.
Inventors: |
Ledner; Albert C. (New Orleans,
LA) |
Family
ID: |
23350538 |
Appl.
No.: |
05/344,436 |
Filed: |
March 23, 1973 |
Current U.S.
Class: |
182/5;
188/65.4 |
Current CPC
Class: |
A62B
1/14 (20130101) |
Current International
Class: |
A62B
1/00 (20060101); A62B 1/14 (20060101); B65h
059/14 (); A62b 001/14 () |
Field of
Search: |
;182/5,6,7
;188/65.4,65.5,65.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Machado; Reinaldo P.
Attorney, Agent or Firm: Semmes; J. Gibson
Claims
Having described my invention in such clear and complete detail as
to enable one of ordinary skill in the art to make and use it, I
claim:
1. A device useful for emergency descent, comprising:
A. a housing having openings therein;
B. a flexible strand passing through the openings of the
housing;
C. means located within the housing for directing the strand
through a tortuous path thereby to provide resistance to movement
of the strand through the housing;
D. means located within the housing in coactive relationship to the
strand and responsive to movement of the strand for preventing
movement of the strand through the housing by displacing portions
of the strand into contact with one another within the tortuous
resistance path; and
E. selectively actuable means for deactuating the means for
preventing movement of the strand.
2. A device useful for emergency descent, comprising:
A. a housing having openings therein;
B. a flexible strand passing through the openings of the
housing;
C. means located within the housing for directing the strand
through a tortuous path thereby to provide resistance to movement
of the strand through the housing;
D. means located within the housing in coactive relationship to the
strand and responsive to movement of the strand for preventing
movement of the strand through the housing;
E. selectively actuable means for deactuating the means for
preventing movement of the strand; and
F. means located within the housing for selectively adjusting the
rate of speed with which the strand moves through the housing when
the means for preventing movement of the strand has been
deactuated.
3. A device useful for emergency descent, comprising:
A. a housing having openings therein;
B. a flexible strand passing through the openings of the
housing;
C. means located within the housing for directing the strand
through a tortuous path thereby to provide resistance to movement
of the strand through the housing;
D. means located within the housing in coactive relationship to the
strand and responsive to movement of the strand for preventing
movement of the strand through the housing; and
E. selectively actuable means for deactuating the means for
preventing movement of the strand, comprising:
a cable operatively engaged with the means for preventing movement
of the strand to remove it from contact with the strand;
an opening in the housing for the cable;
a gripping handle;
means attached to the housing for permitting the gripping handle to
swing from one side of the housing to the other after the strand
has moved therethrough; and
means attached to the gripping handle for pulling the cable to
deactuate the means for preventing movement of the strand.
4. A device useful for emergency descent comprising:
A. a housing having openings therein;
B. a flexible strand passing through the openings of the
housing;
C. tortuous path means for causing the strand to move in opposite
directions in closely adjacent paths as it passes through the
housing, thereby to provide resistance to movement of the strand
through the housing;
D. means located within the housing in coactive relationship to the
strand and responsive to movement of the strand for causing
portions of the strand in the closely adjacent paths to contact one
another, thereby providing resistance to movement of the strand;
and
E. selectively actuable means for deactuating the means for causing
portions of the strand to contact one another.
5. The apparatus of claim 4, wherein the means for causing the
strand to move in opposite directions comprises:
C1a. a first pair of laterally spaced pins attached to the housing
beneath which the strand is threaded;
C1b. a second pair of laterally spaced pins attached to the housing
below and spaced outwardly of the first pair, over and around the
first of which and beneath the second of which the strand is
threaded;
C1c. a pin attached to the housing around which the strand is
threaded;
C1d. a third pair of laterally spaced pins attached to the housing
over the first of which and over and around the second of which the
strand is threaded; and a fourth pair of laterally spaced pins
attached to the housing over which the strand is threaded.
6. The apparatus of claim 4 wherein the means for causing portions
of the strand to contact one another comprises:
D1a. first and second brake levers;
D1b. pivot means for mounting the levers adjacent the closely
adjacent paths;
D1c. a first brake shoe plate mounted on the first brake lever and
contacting the strand at angle leading in one direction of motion
of the adjacent strand through the housing; and
D1d. a second brake shoe plate mounted on the second brake lever
and contacting the strand at an angle leading in the opposite
direction of motion of the adjacent strand through the housing,
whereby as the strand moves through the housing in either
direction, the respective brake shoe plates will be caught by the
strand and the levers rotated to force the shoes into braking
contact with the strand and to force the portions of the strand in
the closely adjacent plates to contact each other.
7. The apparatus of claim 6, further including:
D1e. resilient means for biasing the respective brake shoe plates
into contact with the strand.
8. The apparatus of claim 6, wherein the selectively actuable
deactuating means comprises:
E1. first and second brake release links each having a first end
joined respectively to the first and second brake levers and each
link having a second end, the second end of the first link being
pivotally joined to the second end of the second link;
E2. resilient means for biasing the respective brake shoe plates
into contact with the strand; and
E3. cable means pivotally joined to the second ends of the brake
release links for moving the brake shoe plates from contact with
the strand.
9. The apparatus of claim 4, further including roller means for
guiding the strand into and out of the means for causing the strand
to move in opposite directions in closely adjacent paths.
Description
FIELD OF THE INVENTION
This invention relates to emergency escape devices, particularly
those permitting descent from dangerous locations such as burning
buildings by means of apparatus which will descend a strand of
webbing or similar material under the control of the escaping
person or objects.
Such devices have been known, U.S. Pat. No. 300,090 to Larson et
al, shows an early device in which a strand of rope is directed
through a tortuous path housing and the rate of descent along the
rope is controlled by cam levers which may be actuated by the
ecaping person or by persons on the ground or in the adjacent
building. U.S. Pat. No. 722,713 to Johnson shows another device
which permits the operator to descend along a strand while
controlling his speed with a pair of rope gripping jaws. U.S. Pat.
No. 812,950 to Price shows yet another tortuous path escape device
with a friction brake which permits control of the speed in only
one direction along the strand.
U.S. Pat. No. 933,685 to Wray illustrates an escape system which
permits movement in either direction along the strand and includes
separate friction brakes for control of movement in the opposing
directions. U.S. Pat. No. 1,059,754 to Paquet depicts yet another
tortuous path fire escape in which the strand is directed along a
helical path through the housing and may be engaged by the operator
with hand operated friction brakes which control the rate of
descent in either direction. U.S. Pat. No. 2,544,964 to Phelan
discloses a fire escape apparatus in which the strand is directed
around a stationary sheave, through a pair of braking devices for
controlling the rate of movement in one direction along the
strand.
Numerous problems have been experienced with devices such as the
above. For example, an escaping person is required to actuate the
speed control devices using levers separate from the grips on which
he would normally steady himself during his descent. This reduces
the safety of such devices. Also, the effectiveness of the speed
controls in most instances depends upon the strength of the
escaping person who applies the control. This has the obvious
disadvantage of making the device useless for weak or frightened
users who might not have sufficient strength to operate the device
properly.
SUMMARY OF THE INVENTION
A strand of webbing, rope or similar material is directed through a
tortuous path within a housing. The strand is so directed that a
plurality of portions of the moving strand are arranged to move in
approximately parallel paths in close proximity to each other but
in alternately opposite directions. Strand braking means, actuable
from outside the housing are provided to selectively prevent
movement of the strand in one or the other direction through the
housing. When the braking means are actuated, the neighboring
portions of the moving strand are automatically driven into contact
with each other under the action of the brake, which increases
braking efficiency. A handle is pivoted about the housing and
includes easily moveable means for actuating the brake within the
housing. When the housing has moved to one end of the strand after
a descent, the handle may be swung over to the other side to ready
the device for immediate reuse.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a plan view, partially in section, of the invention;
FIG. 2 is a side elevation view, partially in section, taken along
line 2--2 of FIG. 1;
FIG. 3 is a plan view in section of an alternate embodiment of the
combination handle and brake deactuating mechanism.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
There follows a detailed description of the invention, reference
being had to the drawings, in which like reference numerals
designate like elements of structure in each of the several
FIGURES.
FIG. 1 shows a plan view of the invention, partially in section. An
essentially rectangular housing 10 of suitable material such as
aluminum or high impact resistance plastic includes side wall
openings 12 and 14 to permit movement of a strand 16 of webbing,
rope or similar material through the tortuous path resistance 18
and braking mechanisms 20 and 22 located therein. Also included in
housing 10 are side wall openings 24 and 26 for attachment of
combined handle and brake actuating mechanism 28.
The strand of webbing or similar material is threaded through
opening 12, under roller 30, over roller 32 and under pins 34 and
36. It then passes over and around pin 38 and reverses direction
back along itself and under pin 40 to pass over and around roller
42. From there it reverses direction again back along itself and
over pin 44 located below pin 40 to pass over and around pin 46,
located below pin 38. The strand reverses direction a third time to
pass over pins 48 and 50, located below pins 34 and 36, around
roller 52, over roller 54 and out through opening 14. This unique
tortuous path resistance 18 provides closely spaced, essentially
parallel paths which permit the housing to move along the strand at
a reasonable rate of speed when weight is applied via handle
28.
Located above and below the tortuous path resistance 18 are
automatically acting braking mechanisms 20 and 22 which may be
deactivated by the user to control movement of the housing along
the strand in either direction. Opposite handed brake levers 56 and
58 are secured to housing 10 by pivot posts 60 and 62. With the
apparatus arranged vertically as shown in the FIGURE, levers 56 and
58 are essentially balanced to maintain attached braking shoe
plates 64 and 66 in light contact with the outermost strands of
webbing in resistance 18. If desired, the braking levers may also
be biased to maintain such contact to ensure proper actuation of
the brake and permit use of the apparatus in other orientations, as
will be discussed subsequently. To understand the automatic
function of the brake levers, consider that weight is placed on
handle 28 so as to tend to move housing 10 along strand 16 and
cause strand 16 to move through the housing from opening 14 to
opening 12. Braking shoe plate 66 is mounted on lever 58 at an
angle so that it leads in the direction of movement of the strand
16 in this example. Once enough weight is applied to handle 28 to
overcome the friction of resistance 18, the strand 16 will begin to
move; however, since shoe plate 66 is angled into contact with
strand 16, it will be caught by the strand causing lever 58 to
rotate clockwise about pivot post 62 to the position shown in the
dotted lines. The more strand 16 moves due to applied weight, the
further will lever 58 be rotated by the combined effects of the
shoe plate 66 and the strand 16. Thus, the braking effect increases
as more weight is applied by increasing the friction between shoe
plate 66 and strand 16 and by displacing the essentially parallel
oppositely moving strands in resistance 18 into contact one
another. Opposite handed brake lever 56 and shoe plate 64 provide
no resistance to movement of the strand 16 in this direction, but
function identically to brake lever 58 and shoe plate 66 when the
strand is moved through the housing in the opposite direction. If
desired, the ends 65 and 67 of brake shoe plates 64 and 66 may be
roughened or textured to increase the friction with strand 16;
however, increased wear of the strand will be experienced. Pins 36
and 48 ultimately serve as stops for levers 56 and 58.
Attached to elongated extensions 68 and 70 of brake levers 56 and
58 are brake release links 72 and 74, using suitable pins 76 and
78. Pin 80 joins the opposite ends of links 72 and 74. Stretched
between pin 80 and pin 82 is biasing spring 84 which serves to bias
the brake shoe plates into contact with strand 16 to ensure the
automatic operation of the brakes as discussed above. Spring 84
also returns the brake levers to their balanced, engaged position
after the escaping person reactivates the brakes using handle
28.
Also attached to pin 80 is brake deactivating cable 86 which passes
through motion stops 88 and 90 before reaching pivot hinge 92
located in opening 26. Motion stop 80 includes tapered bore 94 to
facilitate movement of cable 86 to the dotted line position during
the automatic actuation of brake lever 58. Secured to cable 86 is
stop element 96 which prevents movement of cable 86 beyond motion
stop 88 under the influence of spring 84, which could result in the
inadvertent locking of the brake actuating mechanism in the "on"
position due to excessive movement of links 72 and 74. Stop element
96 also prevents movement of the cable beyond motion stop 90 under
the influence of the operator, which could result in the
inadvertent locking of the brake deactuating mechanism in the "off"
position.
Cable 86 passes through bore 98 of pivot hinge 92 to the exterior
of housing 10. Pivot hinge 92 includes tapered bore insert 100
which facilitates movement of cable 86 as handle 28 is rotated
about housing 10. Opposite pivot hinge 92 on housing 10 is pivot
hinge 102. Depending from the hinges are arms 104 and 106 which
connect to handle 28. Handle 28 comprises an inner tubular portion
108, to which arms 104 and 106 are attached using bolt 110 and
suitable fasteners 112 and 114. If desired, tubular portion 108 may
be a solid piece of suitable material or may be filled with impact
resistant plastic for greater rigidity. Surrounding tubular portion
108 are gripping tubes 116 and 118, which include slots 120 and 122
for arms 104 and 106. Tube 116 is stationary relative to tubular
portion 108 and carries reinforcing ring 124 and eyebolt 126 near
the center of handle 28. A seat or sling may be attached to eyebolt
126 for the use of the escaping person, or the person may simply
hang from the handle 28 during descent.
Gripping tube 118 is rotatable relative to tubular portion 108 and
has affixed thereto the end of cable 86, as at 120. To permit brake
deactuation via cable 86 and gripping tube 118, slot 122 is
extended part way around the circumference of tube 118 to allow
rotation of the tube which pulls the cable and deactuates the
brakes. Arm 106 may include a cable guard 128, if desired, to
prevent fouling of cable 86 in use.
An adjustable control over the rate at which the strand 16 moves
through housing 10 may be provided by adjustable resistance
elements 130 and 132. Outer telescopic members 134 and 136 are
affixed to motion stop 90 by pins 138 and 140. Located within
members 134 and 136 are plungers 142 and 144, which carry braking
plates 146 and 148 on their outer ends and are movably disposed in
guide members 150 and 152. Selectively movable adjustment flanges
154 and 156 are mounted on the exterior of members 134 and 136
using suitable fasteners such as set screws 158 and 160. Flanges
162 and 164 are mounted on plungers 142 and 144. Between adjustment
flanges 154 and 156 and flanges 162 and 164 are disposed springs
166 and 168 which act to force braking plates 146 and 148 into
contact with strand 16. By moving adjustment flanges 154 and 156,
the compression of springs 166 and 168 may be changed, thereby
providing more or less resistance to the movement of strand 16 and
controlling the rate of descent. If desired, the contact surfaces
of braking plates 146 and 148 may be roughened or textured to
provide additional resistance; however, this increases the wear on
the strand material considerably.
FIG. 2 shows a side elevational view, partially in section, taken
along line 2--2 of FIG. 1. The rotating mounting of roller 54 and
the stationary mount of pin 36 are shown. If desired to provide
more or less friction in the toruous path resistance 18, various of
the rollers may be made stationary pins or the pins may be made
rotating rollers, without departing from the spirit of this
invention.
FIG. 3 is a plan view in section of an alternate embodiment of the
combination handle and brake deactuating mechanism 28. Handle 28
comprises a tubular portion 170 which is attached to arms 104 and
106 by rings 172 and 174 and suitable fasteners. Located within
tubular portion 170 is cable tensioning lever 176, mounted for
rotation about pivot post 178. Lever 176 has an extension 180 on
one end which extends through opening 182 in tubular portion 170 to
a position where it may be easily actuated by the thumb of the
escaping person as he grips the handle. Cable 86 extends through a
bore 184 in ring 174 and tubular portion 170 and is attached to the
other end of lever 176 using fastener 186. As extension 180 is
depressed, cable 86 is drawn downward, thereby deactuating the
braking mechanisms in housing 10, as previously discussed.
Woven webbing such as shown in the drawings has been discovered to
be a superior strand material for use with the invention due to its
combination of large friction contact area, great flexibility and
strength; however, it will be appreciated that other materials such
as rope or thin cable could be used without departing from the
spirit of this invention.
In use, one end of the strand of webbing is affixed to a high point
in the structure from which escape is to be made. The escaping
person then grasps the handle and places his weight against the
friction of the tortuous path resistance and adjustable resistance
elements, by hanging from the handle or sitting in an appropriate
device attached to the handle. Movement down the strand will start
when the brake is released using the release mechanism located in
the handle, and may be discontinued by untwisting or releasing the
release mechanism. When the escaping person has reached safety, the
strand will have been drawn through the housing, at which time the
handle may be flipped over to the other side, thus readying the
inventive apparatus for immediate reuse. For returning the device
to the elevated point of danger, the next escaping person need only
drawn it back up using the webbing and change the end of the
webbing attached to the high point in the structure.
* * * * *