US2998863A - Fire escape ladders - Google Patents

Description

p 1951 c. E. LARSON 2,998,863

FIRE ESCAPE LADDERS Filed Aug. 3, 1959 2 Sheets-Sheet 1 INVENTOR CLAYTON E. LARSON ATTORNEY p 5, 1961 c. E. LARSON 2,998,863

FIRE ESCAPE LADDERS Filed Aug. 3, 1959 2 Sheets-Sheet 2 ,44 EIE: 5.

INVENTOR CLAYTON E. LARSON BY WM ATTORNEY 2,998,863 FIRE ESCAPE LADDERS Clayton E. Larson, Weston, Conn assignor to White Metal Rolling & Stamping Corporation, Brooklyn, N.Y., a corporation of New York Filed Aug. 3, 1959, Ser. No. 831,176 1 tClairn. (Cl. 182-164) 1882, Hewitt 412,752 of 1889, and Dobbs 499,523 of' r 1893. Further, these early disclosures taught the need for some means incorporated in the foldable ladder structure by which the rungs of the ladder would be held outwardly from the exterior of the building wall to permit sufiicient space for the users foot on the rungs and thus mitigate the danger of a serious fall. Although the need for fire escape ladders of the type disclosed in these patents persists today, especially in residential type dwellings and smaller type apartment houses, the problem of retaining the desirable features of such ladders and yet providing the ladder with a sufficient amount of stability when it is being used to escape from a burning building has not been solved by the prior developments in this art. Another problem of some concern is the provision of means by which such a ladder can be quickly and safely afiixed to the building. Further, it is especially desirable to stow the ladder compactly so that it will not interfere with the eifective use of building space or constitute a nuisance when not in use.

A principal object of this invention is to provide new, unique, articulated, foldable fire escape ladders.

Anotherv object of this invention is the provision of foldable fire escape ladders which are easily and compactly stowed and yet which are capable of being quickly made available for use in case of an emergency.

A further object of this invention is that of providing foldable fire escape ladders having highly effective means for attachment to the building opening with which they are to be used. v

Another object of this invention is the provision of extremely safe means for attaching foldable fire escape ladders to buildings which means facilitates the use of inexpensive and highly effective manufacturing techniques.

Still another object of this invention is to provide foldable fire escape ladders which are capable of being suspended along the exterior surface of the building wall and held outwardly therefrom so as not to interfere with effective use of the rungs, and yet which are extremely stable while supporting the weight of at least one adult person.

Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter; it should be understood, however, that the detailed description, while indicating preferred embodiments of the invention, is given by Way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

In general, the aforementioned objectives are achieved by a ladder including a plurality of articulated ladder sections, each of the sections being connected to each other by an intermediate wall bearing member having upper and lower pivotal connections to respective ladder sections,

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2 and further, having two wall engaging feet or bearing points, which points are spaced at a distance from each other greater than the distance between the pivotal connection of the wall bearing member to. the ladder sections. Also, the structure is equipped with a pair of flexible chain sections at the upper end thereof for connection to a building by a new and improved hook structure.

A more complete understanding of the new and improved fire escape ladders of this invention and their method of use may be had by reference to the accompan ing drawings in which:

FIG. 1 is a perspective view showing a fire escape ladder of this invention suspended along the exterior wall surface of a building; I

FIG. 2 is a fragmentary side elevation illustrating the adaptability of the new and improved fire escape ladders of this invention to an irregular wall surface;

FIG. 3 is an enlarged, fragmentary plan view showing an improved connecting link by which the fire escape ladder is aflixed to a building window or the like;

FIG. 4 is a side view of the connecting link illustrated in FIG. 3;

FIG. 5 is an enlarged, fragmentary plan view of an alternative form of connecting link for afiixing the fire escape ladder to a building window or the like; and

FIG. 6 is a sectional side elevation illustrating stowage of the fire escape ladder of this invention.

The fire escape ladders of this invention comprise a plurality of sections 10 which may vary in number,v

although they should be sufiicient in number to have the composite length of the ladder extend at least from the window or other opening in the building from which the ladder is suspended to ground level; Each of the sections 10 includes a pair of side rail members 12, a rung member 14 and a pair of rung brace members 16. Preferably, the rungs and rung brace members are affixed to the side rails 12 by rivets 18, although other fastening means, such as bolts or welding, may be used in place of the rivets. Further, only one rung is shown with each ladder section 10 and while this construction is preferable to permit stowage within as small a compartment as possible, there may be more rungs per section.

Each of the ladder sections 10 is articulately connected to the other through a wall engaging member 20. This member is generally of X-shaped configuration, and the outwardly facing legs thereof 22 are formed having apertures to receive rivets, bolts or other fastening means 24, which extend through the ends of the side rails 12 in a manner such that the upper and lower side rails for each joint are pivotally connected to the wall bearing member 20 and thus hinged or articulated with respect to each other.

Each wall bearing member 20 is provided with a pair of inwardly facing legs 26 engageable with the exterior surface of a wall designated by the numeral 28 in FIG.

2. It is to be noted that the ends of the legs 26 are cut at such an angle that the inwardly facing edge 30 thereof intersects with edges 32 to form inwardly and vertically directed points 34. In other words, a bearing line '36 established by the two points 34 on each bearing member 20 defines with the inwardly facing edge 30 of the wall bearing leg portions 26 an acute angle of substantial magnitude indicated by the arrow 38 in FIG. 2. In view of thefact'that the points 34 of the wall bearing member 20 are spaced at a distance from each other greater than the distance betweenthe rivets or bolts 24, a bearing structure is provided which offers a great amount stability and thus resistance to tipping of the bearing members in the direction of ladder length. Also, the twopoint bearing arrangement, as can readily be appreciated from FIG. 2 of the drawings, enables the bearing members 20 to readily adapt to'hi-ghly irregular wall surfaces with- 3 out any tendency to cause rocking or otherwise tipping in the direction of ladder length.

The angle 38 whichthe lower or inner edge portion 30 of the bearing member makes with the line established by the points 34 is also extremely important to the fire escape ladder of this invention. It will he noted that because of this arrangement, any tendency for the wall bearing members 20 to be moved vertically along the wall will be opposed by anchorage of the points 34 therein. Such vertical movements may develop as a result of an outward pulling by a person descending the fire escape ladder in the region of his hands. Correspondingly, an inward pressure is developed by the users feet. Since the upper end of the ladder is anchored to the building, the outward force developed by the users hands will necessarily result in a tendency for that portion of the ladder in the vicinity of the users feet to be moved upwardly. However, because of inward pressure exerted by the users feet coupled with the angle at which the points 34 meet the wall, this tendency for movement will be resisted, thus greatly enhancing the stability of the ladder.

Stowability of the improved fire escape ladder of this invention is illustrated by FIG. of the drawings. As shown, the ladder is in its folded condition, each of the sections being collapsed about the joint established by the members 20 and rivets or bolts 24, and positioned within a container 40 having a cover 42. As illustrated by the phantom lines in FIG. 5, the ladder sections are folded upon one another in generally accordion fashion. In this manner, the sections and wall bearing members 20 fold compactly upon one another without in any way impeding the removal of the ladder from the container 40.

An improved manner of connecting the fire escape ladder of this invention to a building window or the like is illustrated in FIGS. 3 and 4. A pair of chains 44 are affixed to the upper section of the ladder and each terminates in a link 46 provided with a hook retaining link 48 which carries a book 50 and a generally C-shaped partial link 52 slidably thereon. The shank portion 52 of the hook 50 is curved in a manner such that to provide a link seating portion 54, the advantages of which will be more fully described hereinafter.

A generally inverted, U-shaped loop 56 having'the ends of its legs welded or otherwise anchored in a plate member 53 to form a closed loop, is adapted to be aifixed to the building by means of screws 60. It will be noted the plate member 58 is arranged such that its longitudinal axis is in the direction of pull by the chains 44, and further, that the loop 56 is also aligned with this axis. Through this arrangement, a minimum of strain is placed on the screws 60. Two such loops are provided and while as shown, each plate 58 is attached to the upper surface of a window sill 62, it is to be understood that it can be attached at any point on the interior building wall as suggested by the view seen in FIG. 1.

To connect the ladder chain to the loop 56, the hook 50 is inserted-therethrough from the inside and the hook engaged on the loop 52. Because of the offset of the link seating portion with respect to the aperture in the hook shank which receives the link 48, any pull on the chain 44 will tend to urge the hook away from the link 48. Since this is opposed by engagement of the hook of the loop 52, there is no danger of the chain becoming disengaged from the U-shaped loop 56.

A preferred alternative form of hook structure for securing the fire escape ladder to a building window or the like is shown in FIG. 5. In this instance, the terminal links 46 of the chains 44 each carry a hook generally designated by the numeral 64. The hook is formed having a shank portion 66, a rear portion 68 and a forward or engaging portion 70. The rear portion 68 of the hook is provided with a forwardly extending portion 72 to engage the link 46. The portion 72, in turn, is formed 'having an internally threaded aperture to receive a screw 74, which, when in place as shown, positively fixes the hook 64 on the link 46. The portion 72 is further provided at its outer edge with a ledge or flat 76 terminating in a rearwardly extending slot 73 to receive a leaf spring 80. The spring is cantilevered from the flat 76 and retained in position by the screw 74 extending therethrough.

The front portion 70 of the hook 64 is arranged to engage the loop 54 and terminates in a ledge 32 to seat the spring 80. Thus, when the spring is in position shown in solid lines, the hook 64 is firmly secured to the loop 54. When it is desired to remove the hook, the spring is do pressed to the position shown in phantom lines and the hook is removed from the loop 54 in a manner well known in the art. n,

it is to be noted that the hook 64 is of constant thickness as indicated by the shading in FIG. 5, and that accordingly, only one view thereof is necessary to fully illustrate its configuration. This configuration readily permits the use of extruding techniques to manufacture the hook since the material from which the hook is made is merely extruded through a die and the bar thus formed sliced into lengths equal to the desired hook thickness.

In use, after the U-shaped loop and plate members 56 and 58 have been affixed to the window sill desired to be used as an emergency escape outlet from the building, the ladder is merely stowed in the container 40 in a position where it is readily accessible. In the event an emergency arises wherein use of the ladder is necessary, the box lid 42 is opened, and the chains attached to the loops 56 in the manner aforementioned. The ladder is unfolded and removed from the box and suspended over the exterior of the building wall such that the wall bearing portions 29 are facing inwardly and engaging the wall as shown in FIG. 1. The person then merely descends the ladder facing the building in much the same manner as he would descend any ladder.

There is provided by this invention an extremely safe and stable fire escape ladder Which may be easily stowed and yet quickly removed from stowage and affixed to any building Wll'ldOWS or other opening. Further, it is to be distinctly understood that the foregoing description is illustrative only, and that various changes in details may be made without departing from the scope of this invention as defined in the appended claim.

I claim:

A foldable fire-escape ladder adapted to be suspended along-the exterior of a building comprising: a plurality of ladder sections, means for connecting said sections including a Wall engaging member formed having two point-bearing foot portions on one end and two apertures on the other end, and means for engagement with said apertures for pivotal connection of said sections to said Wall engaging member, said foot portions being spaced at a distance from each other greater than the distance between said apertures and each having a point which is defined by a pair of intersecting planes, both of said planes being disposed at an acute angle with respect to a bearing line established by said two foot portions and the planes defining said angle on one foot portion being oppositely inclined with respect to those of the other foot portion.

References Cited in the file of this patent UNITED STATES PATENTS 261,847 Gratf Aug. 1, 1882 644,265 Thirion Feb. 27, 1900 663,922 Neely Dec. 18, 1900 1,102,461 Vaughan July 7, 1914 2,604,679 Gise July 29, 1952 2,612,670 Pierre Oct. 7, 1952 2,648,881 Devonshire Aug. 18, 1953

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