US159521A - Improvement in extension-ladders - Google Patents

Description

FICE.

JEREMIAH B. MAHONY, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN {EXTENSION-LADDERS.

Specification forming part of Letters Patent No. 159,521, dated February 9,1875; application filed November 2, 1874.

To all whom it may concern Be it known that I, JEREMIAH B. MAHONY, of Boston, in the county of Suffolk, State of Massachusetts, have Vinvented a certain new and useful Improvement in ,Extension-Ladders, of which the following is a description sufficiently full, clear, and exact to enable any person skilled in the art or science to which my invention appertains to make and use the same, reference being had to lthe accompanying drawing, forming a part of this speciication, in whicl1 l Figure l is an isometrical perspective view, showing the improvement.

My invenlion relates to that class of ladders which are extensible, or designed more espe! ciallyl'or firemens use; and consistsin a novel construction and arrangement of the parts, as hereinafter more fully set forth and claimed, by which a simpler and more effective device of this character is produced than is -now vin common use.

In the drawing, A is the base, provided with the cross-barsB and tenons w and is designed to be connected with the main ladder O by the ropes or guys M and hooks N. Disposed in the lower part of the mainladder there is a crankshaft, H, provided with the pulleys 1 l, and in the upper part there is a shaft provided with the pulleys 2 2. Two cords or belts, I, having their ends attached at J in the lower rails of the irst splice or ladder D, pass around or under the pulleys 1 1, and over the pulleys 2 2. There are also two cords or belts, m m, attached at L to the upper part of the ladder O, and passingl over the pulleys 3 in the lower, and the pulleys 4. in the upper, part of the ladder D, being also attached at K to the lower end of the third splice or ladder, E. .The ladder D is provided on the outside of each rail with a groove, c, and also with the two clamps a a, which clamps overlap and slide upon the ladders C and E, respectively. There are also two clamps, b b, attached to the upper ends of the ladder O and the lower end of the ladder E, respectively, having flanges or arms projecting into the groove o, the clamps holding` the ladders together, and, with the groove, forming ways or ruudlets, in which they slide upon each other. Jointed to the upper rung of the ladder E by the hinges G there is a ilyin g ladder, F, designed for scalin g French and other steep roofs after the ladders ghave beenA extended.

From the foregoing the nature and operation of my invention will be readily obvious to all conversant with such matters.

y It will be seen that when the crank H is turned toward the base A the belt I will be carried around the pulleys l 2, and, being fast in the lower end of the lad der D, will cause the same to be elevated or slide upward along the "lower ladder, which movement ofthe ladder D will also cause the belts m m to pass around the pulleys 3 4, which belts, being fast to the ladder O and bottom of the ladder E, will elevate the ladder E in a maunerreadily apparent without more specific description.

The belts I M m may be made of wire-rope, chain, or some other noncoml'iustible material,

,t0 prevent destruction by tire. The rails and rungs of the ladders may also be of metal, it' preferred.

When the heat of a fire or other cause renders it necessary to elevate the ladder at a distance from the building, a counter-balance for the same can be readily made by several men standing upon the baseA. The base may also be provided with'trucks for moving the ladder up to, and away from, a building when partially or fully extended.

Having thus explained my invention, what I claim is The improved extensible ladder described, the same consisting of the ladders C D E, base A, guys M, pulleys l 2 3 4, belts I m, and crank H, combined and arranged to operate substantially as and for the purpose specified.

J EREMIAH B. MAHONY.

Witnesses:

H. E. METGALFE, C. A. SHAW.

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