US666442A - Ladder. - Google Patents

Description

No. 666,442. Patented Ian. 22, 1901.- r. s. SEAGBAVE LADDER.

(Application filed Nov. 14, 1900.)

(No Model.)

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FREDERIO S. SEAGRAVE, OF COLUMBUS, OHIO.

LADDER.

SPECIFICATION forming part of Letters Patent No. 666,442, dated January 22, 1901. Application filed November 14, 1900. Serial No. 36,449. (No model.)

To ctZZ whom it may concern:

Be it known that I, FREDERIO S. SEAGRAVE, a citizen of the United States, residing at O0- lumbus, in the county of Franklin and State of Ohio, have invented a certain new and usefulImprovement in Ladders, of which the following is a specification.

My invention relates to the improvement of ladders, and has particular relation to the construction of an upper or sliding section of an aerial extension-ladder.

The objects of my invention are to provide an improved ladder construction of the class set forth which will be at once strong and durable and capable of withstanding great strain and which, although in the nature of a trussed ladder, will be so constructed as to permit its riding easily on the rungs of the lower ladder-section and to produce other improvements, the details of construction and arrangement of parts of which will be more fully pointed out hereinafter. These objects I accomplish in the manner illustrated in the accompanying drawings, in which Figure 1 is a side elevation of my improved ladder. Fig. 2 is a face or front view of a portion of the same, shown in connection with a portion of the lower section of an extensionladder; and Fig. 3 is an enlarged sectional View on line a: at of Fig. 2.

Similar numerals refer to similar parts throughout the several views.

In carrying out myinvention I employ the parallel legs 1, between which extend at desired intervals transversely-arranged rungs 2. On what I shall term the under side of each of the ladder-legs I secure throughout the length thereof a straight truss or strengthening bar 3, the ends of the ladder being rigidly and securely united with the end portions of the legs through the medium of intervening uniting-plates 4c, the dowel-like projections of which engage corresponding recesses in the bar 3 and the ladder-leg.

In constructing each of the ladder-legs 1 I form the same on its upper side with an upwardly-projecting web or strengthening-truss 1, the latter being of less width or thickness than the body of the leg, although having its inner side flush with theinner side of said legbody. The production of this upwardly-projecting web 1 results in the formation at the junction of the latter and the leg of a shoulder 1 As shown in the drawings, the web portion 1 converges or gradually decreases in width toward the ends of the ladder-leg, the said web being, however, so formed as to impart the greatest height or width thereto at a point below the center of the length of the ladder-section. On the outer or upper face of the web I I secure an upper strengthening or truss bar 6, which, being of greater thickness than the web, projects inwardly beyond the line of the inner surface of the leg, the outer surface of said bar thus being flush with the outer surface of the web.

In constructing the lower section of the ladder, on the rungs of which the upper section above described is adapted to run, I provide the upper end portion of the lower-section legs on their inner sides with journaled rollers 7 these rollers being so located as to provide an upper frictional bearing for the shoulder portions 1 of the ladder-legs 1.

From the construction herein shown and described it will be seen that a ladder side frame is produced which comprises acentral standard or leg and both upper and lower strengthening-bars which have substantially the effect of trusses and that,although this strengthened ladder side construction is employed, said ladder is permitted to slide easily and smoothly upon the rungs of a lower section. It will also be observed that by imparting the greatest widths to the truss-like webs 1 of the ladder-legs at points below the center of the length of the ladder-section said ladder sides are made stronger or have increased strength imparted thereto at the points where the ladder is subjected to the greatest strain.

It will thus be seen that an exceedingly strong, durable, and effective ladder construction is provided which is particularly adapted for employment as the upper laddersection of an extension-ladder, such as is employed on aerial fire-ladder wagons.

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

1. In a ladder construction, the combination with the parallel legs 1 and transverse rungs uniting said legs atintervals, of under side truss-bars running parallel with and united with the under sides of said legs and curved outwardly-bowed upper side trussbars extending throughout the length of and united with the upper sides of said legs, substantially as specified.

2. In a ladder, the combination with the parallel legs 1 each of which has formed therewith an upper side web l the latter being bowed outwardly and transverse rungs connected with said legs, of a truss or strengthening bar running parallel with and secured 16 to the under sides of said legs and a trussbar running over and united with said weblegs and conforming to the curvature of the latter, substantially as specified.

I FREDERIO S. SEAGRAVE. In presence of O. C. SHEPHERD, A. L. PHELPS.

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