US504008A - Third to j - Google Patents

Description

(No ModeL A. D. WEBSTER. EXTENSION LADDER.

Nb. 504,008. Patented Au 29, 1893'.

5i!gr UNITED STATES ATENT OFFICE.

AUGUSTUS D. WEBSTER, OF SPRINGFIELD, ILLINOIS, ASSIGNOR OF ONE-- THIRD TO J. S. OONDELL, JR, OF SAME PLACE.

EXTENSIO SPECIFICATION forming part of Letters Patent No. 504,008, dated August 29, 1893.

Application filed April 24, 1893.

To all whom it may concern.-

Be it known -that I, AUGUSTUS D. WEBSTER, a citizen of the United States, residing at Springfield, in the county of Sangamon, and State of Illinois, have invented a new and useful Extension-Ladder, of which the following is a specification.

This invention relates to improvements in extension ladders, and has for its object to provide a device or attachment for lowering the upper sections of extension ladders'to enable a person to lower himself any distance required gradually without leaving the ladder, and securing himselfby locking the same at any point that may suit his convenience.

With this and other objects in view the invention consists of the construction and arrangement of the parts as will be hereinafter more fully described and claimed.

In the drawingsFigure 1 is a perspective view of a ladder embodying the invention. Fig. 2 is a longitudinal vertical section of the ladder sections. Fig. 3 is a transverse section on the line y-y of Fig. 1.

Like numerals of reference indicate corresponding parts in all the figures of the drawings.

Referring to the drawings, the numeral 1 designates an outer ladder section as shown, and 2 an inner section to which the same is applied. The upper end of each section is tapered slightlyand slotted as at 3 to receive rollers 4, by which means the end of the ladder section that may be resting against a building or elevation, can be conveniently lowered without scraping or defacing the wall or surface against which the end of the ladder may be resting, and also to permit a free movement of one section on the other when the sections have been released to produce an adjustment or movement of the same. On one section is secured a pair of arms 6 that stand outwardly therefrom, and have anti-frictional rollers 7 journaled in the free ends of the same, that are arranged to bear upon the edges of the side rails of another section of ladder which moves over the said section carrying the arms and rollers, and which is designated by the numeral 1. To the opposite, ladder-section 2 is secured another pair of arms 8, having journaled' in the ends Serial No. 471,627. (No model.)

thereof a brake-roller 9, provided with cranks or eccentric spindles 10, which are mounted in bearings in the arms 8, and to one of said Icranks or eccentric spindles is rigidly secured an operating-arm 11, having a hook or catch 12, pivotally connected to the free end thereof. This hook or catch consists of a flat bar having a quarter-twist, and connected thereto is an operating-cord 13. The broadened upper end of the hook or catch is adapted to engage a pin or stud 14, which is arranged perpendicular to one.side of the section which carries the arms 8, to thereby lock the parts in position to cause the brake-roller to hold the sections in fixed relative positions. The eca frictional contact thereof upon the adjacent ladder-section to clamp the same rigidly against the under ladder-section when the operating-cord is taut, or when the catch or hook is engaged with the said pin or stud. When the ladder-sections are extended and it is desired to lower the upper section, the cord 13 is pulled sufliciently to release the catch from the pin or stud 14, after which it is slackened sufficiently to relieve the pressure of the eccentric roller upon the lower section. This pressure may be relieved more or less by the manipulation of the cord to allow the upper section to descend as slowly as may be desired, and dependent, of course, upon the Weight sustained by the ladder. When the upper section reaches the desired point the cord is again tightened to lock the sections together, and the catch is engaged with the stud or pin 14 to hold the roller in the looking position.

It will be understood that the major radius of the eccentric is longer than the distance between the bearings in the arms 8 and the rear side of the lower seotion,whereby the cocentric can never become cra1nped,and hence when the operating-cord is released the pressure of the eccentric is relieved. The said longer radius of the eccentric is below the pivotal point of the eccentric, as will be obvious from the above description.v

It will be seen that the device is operated to unlock or look the same by the same rope or cord with perfect ease and safety, and that weights resting upon the movable ladder seccentric mounting ofthe roller 9 provides for tion can also be lowered at the same time without removing the same from the ladder. The attachment can be applied to either small or large ladder sections, and to the old style of ladders already in use without changing the construction of the same or incurring material expense. The advantages of the improved arrangement are manifold, and in addition to those stated others will appear from time to time to those using the improved construction.

Changes in the form, proportion and the minor details of construction may be resorted to without departing from the principle or sacrificing any of the advantages of this invention.

Having described the invention, what is claimed as new is-- l. The combination of ladder sections adjustably mounted in connection with each other, one of which is arranged to freely move over the other, an eccentrically mounted brake roller carried by one of said ladder sections and arranged to engage the other to lock it in adjusted position, said roller extending entirely across the said ladder section, and means to operate said roller substantially as described.

2. The combination of ladder sections adjustably mounted on each other, a pair of arms carried by one of said sections and supporting anti-frictional rollers, an eccentrically-mounted brake roller carried by the other section and arranged to be operated to clamp the one section against the other, and means to operate the said roller substantially as described.

3. The combination of ladder sections adjustably mounted upon each other, a pair of arms secured to one of said sections and forming bearings for an eccentrically mounted brake roller, a crank arm fixed to said roller at one end, a catch and a cord havingits one end secured to said catch, substantially as described.

4. The combination with slidably-connected ladder-sections, of an eccentric brake roller mounted upon one of the sections to engage another section, a crank arm fixed to said roller, an operating-cord connected to said crank-arm, and a catch to lock the crank-arm in an adjusted position, substantially as specified.

5. The combination of slidably-connected ladder-section's, of parallel arms carried by one section to engage the adjacent section, an eccentric-brake roller mounted in bearings in said arms to engage said adjacent section, a

crank-arm connected to said roller, and an operating-cord connected to said crank-arm and fixed at the opposite end to the rollercarrying section, substantially as specified.

6. In an extension ladder, the combination of ladder sections movably mounted oneach other and having tapered ends with slots therein, rollers mounted in said slots, a pair of arms secured to one of said ladder sections supporting anti-frictional rollers, a pair of arms carried by the opposite ladder section, an eccentric brake roller mounted in the arms, a crank arm attached to one end of said roller, a catch connected to said crank arm, a cord connected to said catch, and an adjacently situated pin or stud with which the said catch engages, substantiallyas described.

In testimony that I claim the foregoing as my own I have hereto affixed my signature in the presence of two witnesses.

AUGUSTUS D. WEBSTER.

Witnesses:

J. S. CONDELL, J12, JOHN S. PENNINGTON.

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