US619334A - John kiciiol and joseph willson - Google Patents

Description

No. 6l9,334.

Pateted Feb. l4, I899. J. mcnm. &. J. WILLSDN.

LA D D E R (Application flled Sept. 10, 1898.)

(No Modal.)

UNlTBD STATES ATENT OFFICE.

JOHN NICHOL AND JOSEPH WILLSON, OF BLENHEIM, CANADA.

LADDER.

SPECIFICATION forming part of Letters Patent No. 619,334, dated February 14, 1899. Application filed September 10, 1898. Serial No. 690,708. (No modal.)

T aZZ whom it may concern:

Be it known that we, JOHN NICHOL and JO-- Britain, residing at Blenheim, in the county of Kent and Dominion of Canada, have invented certain new and useful Improvements in Ladders, of which the following is a specification, reference being had therein to the accompanying drawings.

The invention consists in the peculiar construction, arrangement, and combination of parts, and particularly in the following details: the construction of the combined guide, locking-dog, and stop, the means employed for engaging and disengaging the lower ends of the ladder-sections and for pivoting the upper ends of said sections, the means of securing in position a second extension-section, and the construction of the ladder-ronnds.

In the drawings, Figure 1 is an elevation of our device as arranged for an extensionladder. Fig. 2 is a perspective view of it as arranged for a step-ladder. Fig. 3 is et sectional elevation of the upper ends of the ladder-sections in the position shown in Fig. 2. Fig. 4 is an enla1ged section on line 0c :13, Fig. 1. Fig. 5 is a cross-section on line 2 3 Fig. 1. Fig. 6 is a cross-section on line 22, Fig. 1. Fig. 7 is a perspective view of one side of the main laddersection at its lower end. Fig. 8 is a section on line 10 w, Fig. 1, With the sections separated.

A is the main ladder comprising sides b 29 and rounds c, and B is the extension-section, provided With sides a (L and similar rounds.

0 is a rock-shaft extending across the upper end of the main section. D are rockarms secured to this shaft in recesses E formed in the inner faces of the side bars 19 of the main ladder. These rock-arms are provided at their outer ends With laterally-projecting lugs d, which extend over the side bars of the extension-section B and form guides therefor. The side bars 6 of the main ladder are provided on their inner faces with the longitudinal s1ots 6, With which slides F on the lower end of the side bars et engage. These slides are preferably in the form of anglebrackets secured to the outer sides of the section B, and to engage and disengage them from the slots e entering-slotsf are provided opening into said slots 6 and through which said slides may pass.

In the upper ends of the side bars of the ladder B are formed semicircular bearingfaces g, which engage over the hubs of the rock-amas D, carried by the rock-shaft 0. This forms the pivotal connection between the ladder-sections when they are used as a step-ladder and constitutes a smooth bearing, which allows the sections to be readily moved away from and to each other, as desired.

G is a rock-mm secured to the rock-shatt 0, which has attached toits free end the pulley H.

I is a hoisting-cord secured to the lower round h of the section B and passing over the pulley H and down again to the lower end of the main ladder.

&Vith the parts thus construeted to use the device as an extension-ladder the slides F are engaged with the slots 6. The extension-section B is normally held in any position of adjustment by the arms D, which are in a slightly-inclined position and act as frictiondogs, holding the section from sliding down. To raise or lower the ladder, the operator draws upon the cord I, which will first rock the shaft 0 sufiiciently t0 raise the arms D from their inclined position, freeing the extension-section B, which may then be lifted or dropped, as desired.

T0 use the device as a step-ladder, the section B is lowered to register the slides F with the entering-slots and to engage the notches 9 with their bearings on the rockshaft C. The lower end 01: the section B may then be swung ont nntil it strikes against the lugs d on the rock-arme. D, which act as stops.

It will be noticed that the rock-arms D perform the triple function of friction-dogs, guides, and stops, while their hubs form the pivotal bearings for the extension-section B of the ladder.

The rounds of the ladder are preferably constructed, as shown in Fig. 6 of the drawings, by having end sections i of reduced diameter, with the beveled shoulder 75 between said sections and the larger portion. The side bars of the ladder are provided with apertures corresponding in diameter With the sections 2' and countersunk to fit the beveled shoulders k. With this construction the rounds are mach stronger than where formed with a square shoulder and are less fiable to Corne 1oose from the side bars than where the ends are tapering.

When a greater extension is desired,we preferably provide an extra section J. This is securcd to the upper end of the section B by having notches K at the lower ends of the side bars, adapted to engage With the upper round L 01: the section B, the latter being preferably fiattened at its sides. The upper ends of the side bars et are also notched at M t0 engage with pins N, projecting from the sides of the section J. If desired, instead the rockshaft 0 may be provided with an operating connection 0, extending down one side of the main ladder.

What we claim as our invention is 1. In an extension-ladder the combination With the main and the extension sections thereof, 01: a rock-shaft extending across the upper end of said main section, roek-arms thereon having laterally-projecting lugs engaging With the side bars of the extension-section to form guides and iocking-dogs. therefor, a hoisting-cord for said extension-section, and a connection to said rock-shatt over which said cord passes, substantially as described.

2. In an extension-ladder, the combination with the main section, of an extension-section of less width than the main section, adapted to be arranged intermediate the sides of the h JOSEPH WILLSON.

mark Witnesscs:

C. A. WEDGE, J. J. VON GUNTON.

Images