US1419834A - Adjustable tread stairs - Google Patents

Description

D. W. FELLOWS.

ADJUSTABLE TREAD STAIRS.

APPLICATION HIJED MAY 26. 1921-.

Patented June 13,1922;

DANIEL W. FELLOWS, OF LOS ANGELES, CALIFORNIA.

' ADJUSTABLE TREAD- STAIRS.

Application filed May 26,

To all whom it may concern:

Be it known that I, DANIEL W. FELLoWs, a citizen of the United States, residing at Los Angeles, in the county of Los Angeles and State of California, have invented new and useful Improvements in Adjustable Tread Stairs, of which the following is a specification.

It is the object of this invention to provide a stairway, such as is employed between a boat or dock and any object resting upon.

the surface of water, such as another boat or a float which will rise and fall through changes in the tide.

The present invention provides a stairway of this character wherein the respective treads of the stairway will be maintained parallel and in a horizontal position irrespective of the swinging movement of the stairway.

The invention will be readily understood from the following description of the accompanying drawings, in which: t

Figure 1 is a vertical section through a stairway constructed in accordance with the invention.

Fig. 2 is a similar view showing the swinging end of the stairway elevated as by the lifting of the float upon which said stairway rests, and responsive to a rise in v the tide.

Fig. 3 is a perspective view of one of the treads of the stairway.

Fig. 4 is a similar view showing the uppermost tread of the stairway and the connections with the same.

The improved stairway is illustrated as pivoted at one end to a dock or the like shown at 1 and having its opposite lower end resting on a float 2 upon the surface of water 3. The float will rise and fall responsive to variations in the tide, and as a consequence the stairway will be swung up and down with relation to dock 1. The treads of the stairway are arranged to be maintained parallel and horizontal irrespective of the position of the stairway.

As an instance of this arrangement, an upper tread 4 is pivoted to dock 1. This tread is shown as provided with a rear depending bracket 5, and a pivot rod 6 extends through the bracket and is journaled in eye bolts 7 carried by the dock.

Specification of Letters Patent.

Patented June '13, 1922.

1921. Serial No. 472,644.

The tread is normally fixed in horizontal position as by a bolt 8 received through a slot 9 in bracket 5 and threaded into the dock 1. When, however, there is a possibility of the stairway swinging above the horizontal position, the bolt 8 is removed so that tread 4 is free for swinging movement upwardly by means of pivot rod 6 journaled in eye bolt 7. When the stairway is arranged for normal use i. e.: with the same extending downwardly from its lowermost tread 4, the latter is fixed against the side of the dock by means of bolt 8, and in this position the bracket 5 abutting against the side of the dock will form a brace for the tread 4.

Two side rails 12 and 13 are arranged at each side of the stairway, the rails being pivoted to bracket 5, as shown at 14, and the side rails 13 being pivoted to ears 15 extending upwardly from the front edge of tread 4.

The treads forming the length of the stairway each comprise a tread plate 16 having depending cars 17 at the respective sides of the rear edge of the same and having upturned ears 18 at the respective sides of the front edge of the tread plate. The tread plates 16 are pivoted to side bars 12 by means of pins extending through said side bars and the cars 17, and the tread plates are similarly pivoted to side bars 13 by pins extending through the cars 18 and said side bars.

It will be understood that the tread plates 16 are so arranged between side bars 1213 as to position said tread plates parallel to one another and to tread plate 4, and that as a consequence the tread plates 16 will lie in horizontal planes. The stairway is supported upon float 2 by means of suitable rollers 20 upon the lower ends of side rails 12, and as a consequence the stairway is free for movement relative to the float, and as the latter rises the side rails 12 and 13 will approach a horizontal position, but the tread plates pivoted between the same will maintain their parallel positions in horizontal planes so as to form a convenient stairway.

Various changes may be made without departing from the spirit of the invention as claimed.

What is claimed is:

A stairway comprising a bracket having a tread portion, downwardly and back; vvardly extendingside flanges and upward 5 ly and forwardly extending ears, rails piv-' otally connected to;- the: side; flanges;- rails pivotally connected to the ears, and tread plates having depending ears attheir-reansides pivotally connected to the first rails and having upwardly extending ears at their 10 front sides ::and pivotally connected to the second rai1s'.-

In testimony whereof I have signed my nam o this specification DANIEL W. FELLOWS.

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