US873110A

US873110A - Extension-ladder.

Info

Publication number: US873110A
Application number: US31381306A
Authority: US
Inventors: William Williamson
Original assignee: Individual
Current assignee: Individual
Priority date: 1906-04-26
Filing date: 1906-04-26
Publication date: 1907-12-10
Anticipated expiration: 1924-12-10

Description

No. 873,110. v PATENTED DEC. 10, 1907.

W. WILLIAMSON.

EXTENSION LADDER. APPLICATION FILED APR. 28,1906.

WITNESSES:

\NVENTOR 5 cm, WAsHlNcnrN. a. c

WILLIAM WILLIAMSON, OF SAGINAW, MICHIGAN.

EXTENSION-LADDER.

Specification of Letters Patent.

Patented Dec. 10, 1907.

Application filed April 26. 1906. Serial No. 813.813.

T 0 all whom it may concern:

Be it known that 1, WILLIAM WILLIAMSON, a citizen of the United States, residing at Saginaw, in the county of Saginaw and State of Michigan, have invented certain new and useful Improvements in Extension-Ladders; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as 'wdll enable others skilled in the art to which it appertains to make and use the same.

My invention relates to an extension ladder and I have herein illustrated one embodiment of which my invention is susceptible.

One object of my invention is to provide a novel form of ladder over those heretofore noted, capable of extension and contraction, one of the novel features residing in the fact that the ladder sections are separable from each other by moving the extension section downwardly.

Another important object of my invention is the provision of means adapted to operate as a reinforcing guide strip for the base sec tion of the ladder, such strip performing many important functions such as preventing side sway of the ladder when in use, strengthening the ladder considerably and preventing the splitting of any cross grain timber in the base section.

Still another object of my invention is the provision of an improved means for effecting the raising and lowering of the extension section, such means comprising a peculiar fastening means to which a flexible connection is removably secured.

Another object of my invention is the provision of means carried by the extension section and actuated by a rolling round, on the extension section, said means adapted to take over the rounds of the stationary or base section to adjustably support the extension section at any desired height.

To these and other ends, my invention consists in certain novel features and combinations of parts, together with their equivalents, such as will be more fully disclosed hereinafter and particularly pointed out in the claims.

In the accompanying drawings illustrating one embodiment of my invention, Figure 1 is a front view of one form of my invention when used as an extension ladder, Fig. 2 is a detail perspective view of the lower end of the extension section, Fig. 3 is a vertical sectional view on line .rm of Fig. 1, Fig. 4 is a detail view of the fingers engaged by the flexible connection, and Fig. 5 is a detail side view of one of the latches and its cooperating parts.

Referring to the drawings, A indicates the base section and B the extension section of a ladder constructed in accordance with my invention. The foot of the base section may be spread as-shown, although this is not a necessary incident of my device.-

1 preferably secure reinforcing guide strips 1, 1, to the rails of the base section, as shown, which strips not only operate to prevent side sway of the ladder and greatly strengthen the same, but also prevent the breaking of the rails in case of cross grain timber or knots as well as preventing the splitting of the rails. Furthermore, the strips whose importance cannot be exaggerated, are arranged to lap over or overhang the inner faces of the rails for a purpose hereinafter set forth.

Brackets 3, 3, are securedto the inner faces of the rails of the. base section, such brackets being each provided with an extension 4, from which projects a pin 5, the pins projecting toward each other from the opposite rails. The

pins

5, 5, maybe headed or not, as convenient.

The extension section is preferably narrower than the base section and overlies the face thereof.

The

pins

5, 5, project over the rails of the extension section whereby the latter is securely held against lateral movement away from the base section.

As one means for supporting the extension section at varying elevations 1 preferably provide the following mechanism. The lower round 13 of the extension section is rotatably journaled in the side rails as by means of the

pintles

14, 14, received in bearings 15, in the side rails, the pintles being of less diameter than the round whereby to prevent a longitudinal movement thereof. At opposite ends of the round 13, I secure the

sleeves

16, 16, from which project the

arms

17, 17, having the studs 18, 18, located at the upper free ends, the studs extending in opposite directions. A double latch 19, of A shape in general formation is pivotally secured at its apex to the inner face of each rail of the extension section, at a point between the round 13 and the round next above, the latches each being suitably braced as at 20, 20, the

braces having slots

21, 21, formed therein in which are loosely received the to secure

sockets

30, 30, to the inner faces of the rails of the adjustable section, the sockets adapted to receive the apices of the latches and assisting in the support of the weight of the adjustable section and the operator thereon, the pivot pin passing through the socket and latch. Ordinarily this means of adjusting the extensible section is sufficient since an operator accustomed to such structures can mount the base section pushing the extensible section before him from time to time, the bosses or rolls 11 or 12 engaging the wall and. reducing the friction without marring the surface, but for convenience of others and to facilitate the use of the device, Iprefer to equip the rotatable round 13 with a pair of suitably

curvedfingers

22, 22, the fingers being curved in opposite directions as shown and adapted-to engage and hold a flexible connection 23, which connection may have a knot or other enlargement 24 formed intermediate its ends and caught in the fingers. The plies of the connection ass upward on opposite sides of the rotatable round and thence between the rounds ofthe extension and base sections respectively thence over a double block or pulley 25 secured to the upper round of the base section from whence the ends depend in position to be grasped by the operator. A pull on either end of the connection will operate to raise the extensible section, strain on one ply being adapted to rock the rotatable round in one direction to move the inner lip of the latch away from the rounds of the base section, and pull on the remaining ply operating to rock the round in the opposite direction and cause the inner lip of the latch to overhang the rounds of the base section. Thus it will be seen that in operating the ladder a downward pull can be given both plies of cord until the latches have cleared the round on the base section over which their inner lips have caught, whereupon the weight of the extension section may be supported for an instant on one of the plies alone thereby rocking the round and catches as set forth to prevent the inner lips from engaging the rounds of the base section after which the extensible section may be raised or lowered and when in its adjusted position, a preponderance of strain is applied to the other ply whereby to rock the latch in the opposite direction and cause its lip to engage the adjacent round of the base section. In this manner, the extensible section need not be lowered below the point at which it is to be adjusted nor need itbe raised above the base round on which it is to be supported only that the rounds of the base and extensible sections are so arranged that they lie opposite each other to afford a broadsupport for the feet, rather than alternating with each other. Furthermore, the flexible connection can be instantaneously removed from the ladder and need not be used.

The extensible section is removable from either end of the base section, that is to say, it can be run up so that the foot of the extensible section leaves the head of the base section or the extensible section can be drawn downwardly until its head clears the inwardly projecting

pins

5, 5 which latter mode is much easier to accomplish. It will also be observed that the latches are double, that is to say, each latch has two depending lips, one object of which is to provide a stopfor the latch when its inner lip is caught over around on the base section, the outer lip taking against the sleeve 16, to limit the inward movement of the latch and also when the latch is removed from its engagement with a round on the base section, the inner lip engages the sleeve 16 to limit the outward movement of the latch. Another result attained by this con struction is to permit the extensible section to be reversed in case it becomes warped or sprung, or for any other reason. The reinforcing strips 1, 1, operate to prevent the springing or warping of the base section.

. While I have shown but two sections of an extension ladder, it is plain that more might be used, a plurality of adjustable sections being successively arranged relative to each other.

From the foregoing, it is obvious that I have devised a novel construction which is both simple and efiicient and one which can be placed on the market at a comparatively slight cost.

It is also evident that many changes might be made in the form and arrangement of the several parts described without departing from the spirit and scope of my invention, hence I do not wish to limit myself to the exact construction herein. set forth.

Having thus fully disclosed my invention, what I claim as new, is

1. The combination with a base section and an extensible section, of a rocking round on the extensible section, double latches pivotally secured to the extensible section, and arms projecting from the round and positively engaging the respective latches to swing the latter toward and from the rounds of the base section, the latches adapted to take over the rounds of the base section to sustain the extensible section in adjusted position. i

2. The combination with a base section and an extensible section, of a rocking round on the extensible section, double latches pivotally secured to the extensible section, the latches being apertured, arms projecting from the round, studs carried by the arms and receivable in the apertures in the latches to'positively swing the latches toward and from the rounds of the base section.

3. The combination with a base section and an extensible section slidable relative to the base section, of a rocking round on the extensible section, double latches pivotally secured to the extensible section, arms proj ecting from the round and positively engaging the respective latches to swing the latter toward or from the rounds of the base section, the latches adapted to take over the rounds of the base section to sustain the extensible section in adjusted position, oppositely extending curved fingers on the rocking round and a flexible connection having an enlargement in the bight thereof, for engaging the fingers.

4. An extension ladder comprising base and adjustable sections, latches pivotally supported by the adjustable section for supporting the latter at various points relative to the base section, a rocking rung, meansconnecting the rung and latches, oppositely curved fingers mounted on the rocking rung and a knotted flexible connection independent of the means, connecting the rung and latches for actuating the rung in o posite directions, the knot being releasably eld by i I the curved fingers.

5. An extension and extensible sections, a latch on the extensible section for supporting the same at various heights relative to the base section, a rocking rung, means connecting the rung and latch, curved fingers mounted on the rung and a flexible connection independent of the means connecting the rung and latch, and an enlargement located intermediate the ends of the connection, the enlargement being releasably caught in the curved fingers to rock the rung in opposite directions.

"In testimony whereof, I afiix my signature I in presence of two Witnesses.

WILLIAM WILLIAMSON.

Witnesses:

A. A. EAsTERLY, RALPH S. WARFIELD.

ladder comprising base