US3575263A - Folding fire escape ladder - Google Patents

Abstract

A folding fire escape ladder has an L-shaped first upright adapted to be secured vertically to the side of a building and has an L-shaped second upright parallel to but reversely positioned with respect to the first upright. A plurality of rungs are connected to both uprights, each rung having parallel end portions and an offset intermediate portion, the rungs being pivotally connected at the end portions to the uprights by shoulder rivets having enlarged, flanged heads. Other shoulder rivets extend from the uprights and are positioned to engage the margins of the rung to serve as stops, the other rivets also having enlarged flanged heads adapted to engage one side of the rung as positioners. A latching lever adapted to engage the first upright is releasably held against a fulcrum on the second upright by a spring, there being an actuating cable attached to the lever and to the second upright.

Description

United States Patent I [72] Inventor Cheyenne A. Reinhard 594 Beatrice St., San Leandroc, Calif. 94579 [2]] Appl. No. 861,684 [22] Filed Sept. 29, 1969 [45] Patented Apr. 20, 1971 [54] FOLDING FIRE ESCAPE LADDER 3 Claims, 3 Drawing Figs.

[52] U.S.Cl 182/160, 182/96 [51] Int.Cl. E06c U383 [50] Field of Search 182/159, 160, 96, 95

[56] References Cited UNITED STATES PATENTS 250,901 12/1881 Dunn 182/96 314,899 3/1885 Wilson 182/96 350,047 9/1886 Dunn 182/96 1,026,097 5/1912 Lewis 3,414,081 12/1968 Wedvik....

Primary ExaminerReinaldo P. Machado Att0rneyLothrop and West ABSTRACT: A folding fire escape ladder has an L-shaped first upright adapted to be secured vertically to the side of a building and has an L-shaped second upright parallel to but reversely positioned with respect to the first upright. A plurality of rungs are connected to both uprights, each rung having parallel end portions and an offset intermediate portion, the rungs being pivotally connected at the end portions to the uprights by shoulder rivets having enlarged, flanged heads. Other shoulder rivets extend from the uprights and are positioned to engage the margins of the rung to serve as stops, the other rivets also having enlarged flanged heads adapted to engage one side of the rung as positioners. A latching lever adapted to engage the first upright is releasably held against a fulcrum on the second upright by a spring, there being an actuating cable attached to the lever and to the second upright.

IFOLlDlNG FIRE ESCAPE LADDER The invention relates to means which can be permanently installed on the side of a building, such as an office building or a dwelling or the like, and which normally is unobtrusive and out of the way. The device is located, however, so that in theevent of an emergency, such as a fire, a user can quite readily and easily activate the ladder so that it becomes immediately available for descent or ascent by persons, even persons of considerable weight or simultaneously by a large number of persons.

It is an object of the invention to provide a folding fire escape ladder that normally will be quite unobtrusive and unobjectionable as to appearance when installed on the side of a building near emergency exits, such as doors, balconies, windows and the like.

Another object of the invention is to providea folding fire escape ladder that can unfailingly and always, even after long periods of disuse, be erected quickly into its condition for easy use.

Another object of the invention is to provide a latching mechanism which will under any circumstances release in an emergency.

A further object of the invention is to provide securing devices and stops to make sure that the ladder, when unfolded or extended, is sufiiciently firm and rigid in its extended position to support the weight of a large number of persons.

A further object of the invention is to provide a folding fire escape ladder that when extended is sufiiciently stiff and firm in all directions to afford a reassuring and adequate support for persons using it in an emergency.

A still further object of the invention is to provide a folding fire escape ladder that remains workable despite its exposure to the elements during a protracted period of time.

Other objects together with the foregoing are attained in the embodiment of the device described in the accompanying description and illustrated in the accompanying drawing, in which:

FlG. l is a front elevational view of a folding fire escape ladder erected against the side of a building and shown in broken lines in its open position and shown in full lines in its folded position;

- H6. 2 is an enlarged view like FIG. 1, but showing related portions of the structure of FIG. l in an extended or unfolded position; and

FIG. 3 is a cross section, the plane of which is indicated by the line 3-3 of FllG. 2.

While the folding fire escape ladder pursuant to the invention can be incorporated in a large number of different ways, depending particularly upon the environment or use to which it is especially to be put, it has in practice successfully been embodied as illustrated herein. in this installation the device is utilized on the side of a building 6 which is presumed to have various egress openings adjacent to the location of the ladder, some of them being nearer thev bottom of the ladder and others being nearer the top thereof.

The ladder includes an L-shaped first upright 7', This is conveniently an angle member, preferably fabricated of relatively stiff, aluminum alloy which will hold itsshape well under load and which includes one leg 3 and an adjacent leg 9 at right angles to the first leg. Preferably, the leg 9 is disposed parallel to and adjacent the sidewall of the building 6 and isfastened thereto by means of several spaced brackets 11. These are not only held to the building by'suitable fastenings l2, such as lag bolts or the like, but are also secured to the first upright 7 by fastenings, such as nuts and bolts 13. The disposition of the first upright is with the flange or leg 8 extending out from and disposed at right angles to the side plane of the building 6.

Pursuant to the invention there is. also provided a second upright member 16, likewise of generally angular formation the same as or complementary to the formation of the member 7. That is to say, the second upright has a flange 17' arranged substantially parallel to the flange or leg 9 and hasa flange 18 at aright angles to the flange l7 and disposed substantially parallel to the flange or leg 3. The uprights are so disposed with respect to each other that when they are close together they define a generally boxlike configuration to serve as a partial housing.

To maintain the uprights in their various desired positions, 1 provide a plurality of rungs 21 as connectors. Each rung is like the others so that a description of one applies also to the others. A rung 21, for example, is a strap of similar metal generally flat at its opposite ends 22 and 23. The planar ends are disposed parallel to each other. The intermediate portion 24 of each rung has an angular offset so that one end 22 can die close to the flange 8 whereas the other end 23 can lie close to the flange R8. The rung 21 if desired can have portions somewhat rounded or shaped (not shown) for convenient grasping and the like.

Each of the rungs 21 at the end 22 is pivotally connected to the first upright 7 by means of a shoulder rivet 26. This rivet (HO. 3) has a narrow anchor portion 27 and an adjacent enlarged portion 28 affording an intermediate shoulder designed to butt against the inner face of the flange 3. The flange is first perforated, a rivet is forced in until the shoulder abuts, and then the rivet is deformed as at 29 so that is is firmly held in position. The rung end 22 is accordingly pierced to provide ajoumal slightly larger than the portion 28 so that the rung is pivotally mounted free rotation. The fit is relatively loose on the journal so that even surfaces deteriorated after long exposure will still rotate. in order to hold the rung in position against lateral dislodgement despite a loose journal the rivet has an end flange 31 designed to overlap and to lie closely adjacent the side of the rung 21. In a similar fashion the flange 18 is similarly pierced and carries a shoulder rivet 32 of a similar configuration having an enlarged flange 33 lying against the side of the rung 21 to hold it against axial dislodgement at that end.

To make certain that the rung lies in appropriate, horizontal position when the ladder is unfolded l provide on the flange 3, for each of the rungs, another shoulder rivet 34 disposed so that its intermediate portion 36 lies tangent to the lower edge of the rung 21 when the rung is extended horizontally and so that the enlarged flange 37 on the stop rivet lies against the face of the rung. ln-this way the end 22 of the rung cannot be dislodged laterally or transversely and is well supported from below. ln addition, I provide a similar stop rivet 33 on the flange 18 disposed so that its intermediate portion 39 is abutted by the top edge of the end 23 of the rung 21 when the rung is in horizontal position, In this case the enlarged flange 41 of the second stop rivet lies against the opposite side of the rung from the flange 37 and prevents any lateral shaking or displacementof the rung or of the second upright 16 despite loose pivots.

Great careis taken to position the pivot rivets 26 and 32 far from their associated stop rivets 34 and 38 for substantial leverage while keeping the stop rivet flanges 37 and 41 substantially tangent to the upright edges so as to permit compact folding of the uprights. The stop rivets are also carefully placed so as to have all of the stop shoulder rivets engage their respective rungs substantially simultaneously.

Partly for that reason, the ability of the structure to remain stiff and unshakingwhen extending and to bear loads is more than adequate. The ladder, when extended, can bear the weight of anumber of people at once. Even if a person puts his weight on the ladder before it is completely extended, nevertheless the ladder will open and assume its stop position without shock or failure.

ln use the ladder'is normally in folded condition. For that reason thereis provided a catch mechanism generally designated 13. This catch is mounted on a fulcrum 44 provided by a restricted notch as cut in the flange 17 A bowed portion 47 of the lever 48 bears against the fulcrum. A hook 49 on the end'of the lever in one position lies behind the flange 9. A spring 51 extends from an anchor 52 of the lever to an anchor 53 on the flange l7 and also holds the lever onits fulcrum seat. An actuating cable 54 extends from one end'of the lever 48 to an anchor 56 on the flange 17 preferably a number of feet above the ground so that it is regularly accessible to adults but is not so accessible to children.

Even though the hook may be engaged for a long time, say a number of years, without any operation, then when an emergency exists and the cable 54 is pulled, the hook 49 is readily disengaged. if there should be a mischance and the hook itself does not immediately release, a person can readily dislodge the entire lever 48 from its fulcrum seat against the retention of the spring and can in that fashion disengage the holding device. When released, the outboard upright member 16 will swing away by gravity from its boxlike configuration with the member 7 and will descend until all of the rungs are horizontal and rest against their various stop rivets in what amount to grooves between the flanges of the uprights and the enlarged flanges of the rivets. The entire structure when extended is extremely rigid and stiff and can readily withstand the descent of persons. The ladder is restored to its original condition simply by forcing the outer member back into its position against the inner member and with the hook again engaged.

lclaim:

l. A folding fire escape ladder comprising a first upright L- shaped in transverse cross section, means for securing said first upright to a support such as a building wall, a second upright L-shaped in transverse cross section arranged parallel to and facing opposite to said first upright, a plurality of cross rungs of flat material, a first shoulder rivet having its shoulder abutting said first upright and pivotally connecting one end of one of said rungs to said first upright, a second shoulder rivet having its shoulder abutting said first upright and mounted in said first upright in position to abut a lower surface on said one rung when said one rung is in a horizontal position, an enlarged flange head on said second shoulder rivet adapted to engage the side of said one rung opposite said first upright when said one rung is in a horizontal position, a third shoulder rivet having its shoulder abutting said second upright and pivotally connecting the other end of said one rung to said second upright, a fourth shoulder rivet having its shoulder abutting said second upright and mounted in said second upright in position to abut an upper surface on said one rung when said one rung is in said horizontal position, an enlarged flange head on said fourth shoulder rivet adapted to engage the other side of said one rung opposite said second upright when said one rung is in a horizontal position, and said one rung having substantially planar ends with parallel edges each adapted to engage a respective one of said second and fourth shoulder rivets between said uprights and said flange heads and having an intermediate portion angled to dispose said uprights in a box relationship when said uprights are close together.

2. A folding fire escape ladder as in claim 1 in which said first and third shoulder rivets also have enlarged flange heads, each of said flange heads being positioned and adapted to overlie and substantially engage a different one of the opposite sides of said one rung.

3. A folding fire escape ladder as in claim 1 including a hook lever having an open bowed portion intermediate its ends, means on said second upright for providing a fulcrum adapted to lie in said bowed portion of said hook lever, a spring engaging said hook lever and said second upright for releasably urging said bowed portion of said hook lever against said fulcrum, a hook on one end of said hook lever adapted to engage one end of said first upright, and a cable engaging the other end of said hook lever for pulling said hook lever to tension said spring and for pulling said bowed portion of said hook lever bodily from said fulcrum.

Claims (3)

1. A folding fire escape ladder comprising a first upright Lshaped in transverse cross section, means for securing said first upright to a support such as a building wall, a second upright Lshaped in transverse cross section arranged parallel to and facing opposite to said first upright, a plurality of cross rungs of flat material, a first shoulder rivet having its shoulder abutting said first upright and pivotally connecting one end of one of said rungs to said first upright, a second shoulder rivet having its shoulder abutting said first upright and mounted in said first upright in position to abut a lower surface on said one rung when said one rung is in a horizontal position, an enlarged flange head on said second shoulder rivet adapted to engage the side of said one rung opposite said first upright when said one rung is in a horizontal position, a third shoulder rivet having its shoulder abutting said second upright and pivotally connecting the other end of said one rung to said second upright, a fourth shoulder rivEt having its shoulder abutting said second upright and mounted in said second upright in position to abut an upper surface on said one rung when said one rung is in said horizontal position, an enlarged flange head on said fourth shoulder rivet adapted to engage the other side of said one rung opposite said second upright when said one rung is in a horizontal position, and said one rung having substantially planar ends with parallel edges each adapted to engage a respective one of said second and fourth shoulder rivets between said uprights and said flange heads and having an intermediate portion angled to dispose said uprights in a box relationship when said uprights are close together.

2. A folding fire escape ladder as in claim 1 in which said first and third shoulder rivets also have enlarged flange heads, each of said flange heads being positioned and adapted to overlie and substantially engage a different one of the opposite sides of said one rung.

3. A folding fire escape ladder as in claim 1 including a hook lever having an open bowed portion intermediate its ends, means on said second upright for providing a fulcrum adapted to lie in said bowed portion of said hook lever, a spring engaging said hook lever and said second upright for releasably urging said bowed portion of said hook lever against said fulcrum, a hook on one end of said hook lever adapted to engage one end of said first upright, and a cable engaging the other end of said hook lever for pulling said hook lever to tension said spring and for pulling said bowed portion of said hook lever bodily from said fulcrum.

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