US 3826341 A
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 automatically maintaining an essential uniform rate of descent essentially irrespective of the weight of the escaping person are included, and a unique handle arrangement permits immediate reuse of the device without having to draw the strand back through the housing.
Description (OCR text may contain errors)
United States Patent [191- Ledner [111 3,826,341 [451 July 30, 1974 EMERGENCY DESCENT APPARATUS Inventor: Albert C. Ledner, 5328 Bellaire Dr., New Orleans, La. 70124 Filed: Sept. 11, 1973 Appl. No.: 396,241
Related US. Application Data Continuation-impart of Serv No. 344,436, March 23,
US. Cl. 188/655, 182/5 Int. Cl A62b 1/14 Field of Search 182/5, 6, 7; 188/654,
References Cited UNITED STATES PATENTS 6/1924 Bass 188/654 2,437,864 3/1948 Staley 182/5 Primary Examiner-Reinaldo P. Machado Attorney, Agent, or FirmJ. Gibson Semmes [5 7] ABSTRACT A device useful for descending from an elevated location along a' strand of webbing orsimilar material is disclosed, which includes a housing containing a tortuous path through which the strand is drawn as the housingvmoves downward on the strand. Means for automatically maintaining an essential uniform rate of descent essentially irrespective of the weight of the escaping person are included, and a unique handle arrangement permits immediate reuse of the device without having to draw the strand back through the housing,
6 Claims, 3 Drawing Figures 1 1 EMERGENCY DESCENT APPARATUS REFERENCE TO RELATED APPLICATION This application is a continuation-in-part of application Ser. No. 344,436, filed Mar. 23, 1973 by Albert C. Ledner, for EMERGENCY DESCENT APPARATUS.
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; for example, US. 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 escapingperson or by persons on the ground or in the adjacent building. US. Pat. No. 722,7l3 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. US. 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.
US. Pat. No. 933,685 toWray illustrates an escape system which permits movement in either direction along the strand and includes separate friction brakes for control of movement inthe opposing directions. US. 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. Bass shows in US. Pat. No. 1,497,534 an escape device in which the strand is led around a friction roller and past hand-actuated brake devices at either end of the housing. US. Pat. No. 2,544,964 to Phelan disclosesa 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. I
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. Further, many devices move at speeds directly proportional to the weight of the person, which can result inunsafe descent rates for a heavy person or too slow a rate for a small person such as a child.
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'bu t 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 attached to the housing in proximity to easily movable means for deactuating the brake within the housing using the thumb. When the housing has moved to one end of the strand after a descent, the device is ready for immediate reuse, without having to draw the strand back through the housing. Auxiliary braking means located within the housing apply a continuous but variable, resistance to movement of the strand and are actuated by the weight of the user transmitted through a seat or sling in which the user rides.
BRIEF DESCRIPTION OF THE DRAWINGS I 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 cast 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 handles 28 and 29.
The strand of webbing or similar material is threaded through opening 12, under pin 30, over roller 32 and under pins 34 and 36. It then passes over and around pin 8 and reverses direction back along itself to pass over and around'pin 42. From there it reverses direction' again back along itself 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 36 and 34, around roller 52, over pin 54, out
through opening 14, and over bolt 116 in sling support secured to housing 10 by pivot posts 60 and 62. Levers 56 and 58 are biased at a location remote from pivot posts 60 and 62 by springs 57 and 59, as shown, to maintain attached braking shoe plates 64 and 6 6 in light contact with the outermost strands of webbing in resistance 18 To understand the automatic function of the brake levers, consider that weight is placed on handles 28 and 29 so as to tend to move housing 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 so that it leads in the direction of movement of the strand 16 in this example. Once enough weight is applied to handles 28 and 29 to overcome the friction of resistance 18, the strand 16 will begin to move; however, since shoe plate 66 is biased and-leads into contact with strand 16, it will be caught by the strand causing lever 58 to rotate clockwise about pivot post 62. 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 causing the essentially parallel oppositely moving strands in resis tance 18 to 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 increasethe friction with strand 16; however, increased wear of the strand will be experienced. Pins 36 and 48 ultimatelyserve assto ps for levers 56 and 58.
Elongated extensions 68 and 70 of brake levers 56 and 58 extend from housing 10 through openings 72 and 74 aboveand below handle 29 as shown. Handles 28 and 29 comprise bolts 76 and 78 through openings 24 and, 26, over which are fitted sleeves 80 and 82, washers 84 and 86, lock washers 87 and 88, nuts 90 and 92fand grips 94 and 96. The user of the device may deactuate brake levers 56 and 58 using his thumb on extensions 68 and 70. An alternate brake deactuating mechanism would be that described in my co-pending application Ser. No. 344,436, on page 7, lines 1 to 29; page 8,;lines l to 18; page 9, lines l8 to 25; and page guides 122 and 124 at the other end. The spring clips bear upon strand 16 just adjacent to pins 30 and 54 and thus provide a certain inherent additional resistance to movement of strand 16. Springs 146 and 148 extend between pin retainers 118 and 120 and pin guides 122 and 124 as shown, and tend to reduce the force with which brake pins 134 and 136 are driven into contact with spring clips 138 and 140 by absorbing a portion of the force exerted by the users weight applied through axles 106 and 108. The heavier the person or object supported on sling bolts 114 and'l16, the greater will be the'auxiliary braking force applied, which produces a fairly uniform rate of descent.
FIG. 2 shows'a side elevation view, partially in section, taken along line 2-2 of FIG. 1. The rotatable mounting of sling support arms 112 and the coaction of axle 108 with spring retainer 120 are shown. If desired to provide more or less friction in the, tortuous 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.
, outwardly extending hand guards 146 and 148, which 10, lines 1 to 6; however, the present device is simpler I to manufacture and use and is considered to bean improvement'thereover. r
A further control over the rate at which the strand 16 moves .through housing l0 may be provided by resistance elements 98 and 100 which are actuated in part by the weight of the-user- Elongated apertures 102 and 104 in opposite sides of housing 10 slidably receive sling support axles 106 and 108 from which rotatably depend pairsofsling support arms 110 and 112, which in turn rotatably support sling support bolts 114 and 116. l-l-shaped auxiliary brake pin retainers and spring seats 118 and 120 abut axles 106 and 108 for-movement therewith so that-support axles 106 and 108may bear upon brake pins 134 and 136 when weight is applied-to sling support bolts 114 and 116; Attached to housing 10 are combination spring seatsand auxiliary brake pin guides 122 and 124, which include horizontal spring seating surfaces 126 and 128 and essentially vertical brake pin guide bores'130 and 132. Auxiliary brake pins 134 and 136 are mounted between pin retainers 118 and 120 and pin guides 122 and 124 and extend through bores and 132 into contact with strand braking spring clips 138 and 140. Spring clips 138 and 140 are held in place by fixed posts 142 and 144 at one end and by the sides'of pin deflect the apparatus from contact with projections on the adjacent structure or building from which escape is being made and provide protection from abrasion to the fingers and knuckles of the person using the device.
.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 or vehicle from which escape is to. be made. The escaping person then grasps handles 28 and 29 and places his weight in a seat or sling supported by sling support bolts 114 or 116. The strand begins to;move against the friction of the tortuous path resistance and the auxiliary braking elements but is stopped by the automatic braking levers 56 and 58. Movement down the strand will start when the brakes are released using lever extensions 68 and 70, and may be discontinued by releasing the lever extensions. To increase the rate of descent, the escaping person need only lift himself on handles 28 and 29, thereby atleast partially deactuating the auxiliary braking means and permitting greater speed. When the escaping person has reached safety, the strand will have been drawn through'the housing, thus readying the inventive apparatus for immediate reuse. For returning the device to the elevated point of danger, the next escaping person need only draw it back up using the webbing and change the end of the webbing attached to the high point in the structure.
. 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 the emergency descent of animate or inanimate objects, 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;
F. spring means located within the housing for bearing resiliently upon the flexible strand, thereby to provide additional resistance to the movement of the strand through the housing; and
G. means for increasing the resistance between the spring means and the strand by compressing the spring means in response to the weight of the transported object.
2. The apparatus of claim 1, wherein the tortuous path means comprises:
Cl. means for causing the strand to move in opposite directions in closely adjacent paths as it passes Clb. 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;
Clc. a pin attached to the housing around which the strand is threaded;
Cld. 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.
4. The apparatus of claim 2 wherein the means for causing portions of the strand to contact one another comprises:
Dla. first and second brake levers; 1
Dlb. pivot means for'mounting the levers adjacent the closely adjacent paths;
Dlc. 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
Dld. 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 thestrand 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.
5. The apparatus of claim 4, further including:
' Dle. resilient means for biasing the respective brake shoe plates into contact with the strand. 1
6. The apparatus of claim 2, 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.