US733269A

US733269A - Ladder.

Info

Publication number: US733269A
Application number: US15313503A
Authority: US
Inventors: William W Pope
Original assignee: Individual
Current assignee: Individual
Priority date: 1903-04-17
Filing date: 1903-04-17
Publication date: 1903-07-07
Anticipated expiration: 1920-07-07

Description

l? MODEL.

PATENTED JULY v, 1903;

W W7 POPE. LADDER.

APPLIOATOsNL EILED APR., I'Z, 19(13.

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UNITED STATES Patented July 7, 1903.

PATENT OFFICE. I

LADDER.

SPECIFICATION forming part of Letters :Patent No. 733,269, dated July '7, 1903.

Application iiled April 17, 1903. Serial No. 153,13@ (No model.)

To all whom, t may concern:

Be it known that I, WILLIAM W. POPE, a citizen of the United States, and a resident of Jackson, in the county of Susquehanna and State of Pennsylvania, have invented a new and useful Improvement in Ladders, of which the following is a specification.

My invention relates to an improvement in extension-ladders, the object being, as the name implies, to provide a ladder which can be lengthened and shortened and the sections of which will become automatically locked or unlocked when occasion may demand raising or lowering the sections.

With the foregoing object in View my invention consists in a ladder composed of two or more sections having sliding connections with each other, in combination with counterweighted hooks pivotally connected with one section of the ladder and operating to automatically engage and lock the next section thereto or by reverse motion of the rope or cable and of the movable section to cause a release and permit the ladder to be shortened.

The invention further consists in certain novel features of construction and combinations of parts, which will be hereinafter de scribed, and pointed out in the claim.

In the accompanying drawings, Figure l is a view of my improved extension-ladder. Fig. 2 is a side elevation of the same. Fig. 3 is a detail view of one of the locks, and Figs. 4 and 5 are detail views of the clips.

A and B represent two sections of an eX- tension-ladder. These sections are of ordinary form and alike, except that the movable section B is narrower than the other section A, it just fitting and sliding nicely within its sides and between the rounds a d thereof and the clips b Z) and c c as guides, the clips c c being secured to the lower ends of the movable extension B, and the clips h l) being secured to the upper ends of the stationary section A and embracing the sides of the eX- tension-section B.

A rope or cable l is secured at its ends to the lowermost rounds of the two sections of the ladder, and it is passed over a pulley 2, depending from the top round of the stationary section A of the ladder. By pulling on this rope or cable the upper section is raised and the ladder lengthened, and by the reverse action or slackening of the rope or cable it is lowered.

The automatic lock for engaging or disengaging the movable section (shown in enlarged detail in Fig. 3) will now be described. Two of these are shown; but more or even less could be employed. As they are alike, one only need be described. This lock may be cast of a single piece of metal. It preferably has a hole 3, formed at or near its center, by means of which it is pivoted to a round of the lower section of the ladder, and at one end it is provided with two hooked

ngers

4 and 5. The shorter inger 4 is more rounded than the other and curves or opens upwardly, it being adapted to receive and hold a round of the other section of the ladder, its shape and its position with respect to the pivot being such that it holds and supports a round of the movable section of the ladder when the latter is raised thereto and lowered thereinto. The other finger 5 is much longer and curves in the opposite direction and in a more general curve over and beyond linger 4. On the opposite end the lock has a counterweight 6, which keeps the lock in an operative position for locking or unlocking when the ladder is in position and causes it to resume such position after havingbeen tilted therefrom. The lock is confined against sliding or turning too far on the round where it is placed by a staple 7. Thus it will be seen that the lock acts as a reverse eccentric, and the greater the weight resting upon the upper section of the ladder when extended the closer the sections are drawn together, and consequently the lateral motion of ladder is correspondingly reduced. As the upper section slides inside the lower section, this also prevents swaying. The foregoing features, taken in connection with the fact that the hook is composed of one piece, make a strong, rigid, and perfect-acting ladder.

The operation is as follows: The ladder is first raised. To raise the movable section, the rope or cable is pulled down, the rounds of the movable section pushing aside the fingers of the lock or locks and passing above until the desired length is attained, when the round of the movable section opposite or about opposite the locks is allowed to pass by the finger or ngers 4 until the longer iingers 5 drop over IOO and strike the round. Then the movable section is lowered until the round drops into hooked fingers 4, where it remains securely until the rope or cable is again pulled down to extend the ladder still farther or to lower the movable section. To extend the ladder farther, the operation above described is repeated. To lower it, the rope or cable is pulled until the round last locked pushes aside and clears the longer nger 5, when the latter drops beneath it and the round will force it down, as well as the rounds above, in order, and the movable section will resume its normal position.

It is evident that slight changes'might be resorted to in the form and arrangement and particularly in the number of parts described without departing from the spirit and scope of myinvention, and hence I do not Wish to limit myself to the exact construction herein set forth; but,

Having thus fully described my invention, what I claim as new, and desire to secure by Letters Patent, is-

In an extension-ladder, the combination with a stationary section, of a movable section suitably guided and supported thereon, means for raising and lowering the movable section with respect to the stationary section and means for removably securing the sections together at any predetermined point, the means comprising an integral hook pivotally received upon the stationary section, the hook comprising a long guard-finger extending laterally and approximately horizontally from the longitudinal plane of the ladder, the guard-finger being on a level with the pivotal point of the hook, a shorter, curved hook-finger depending from and located beneath the pivotal point of the hookbody and a counterbalance depending from the hook-body and beneath the pivotal point, the counterbalance located on the same side of the pivotal point with and opposite to the short curved hook-finger, the guard-finger, the hook-linger and the counterbalance all rigidly and immovably connected with one another.

In testimony whereof l have signed this specification in the presence of two subscribing witnesses.

WILLIAM W. POPE.

Vitnesses:

E. L. TANNER, E. l. WHITNEY.