US150005A - Improvement in scaffolds - Google Patents

Description

PATENT @Priori ALONZO S. DRISKO, OF BOSTON, MASSACHUSETTS.

EMPROVENIENT IN SCAFFLDS.,

Specification forming part of Letters Patent No. 150,065, dated April 2l, 1874; application filed March 5, 1874.

l To all whom it may concern:

-Boston, in the count-y of Suil'olk and State of Massachusetts, have invented certain Improvements inv Scaffolding or Staging for the use of masons, carpenters, and other mechanics, of which the following is a full, clear, and exact description, reference being had to the accompanying drawings, making part of this specification, in which- Figure l is a perspective view of my iinproved frame-work for supporting one end of the staging. Fig. 2 is a transverse vertical section through the center of the same.

The ordinary staging or scaffolding employed by masons, carpenters, and other mechanics in building walls, lat-hing, plastering, painting, Ste., consists of a platform composed of plank placed across two or more horses, another platform, also consisting of horses and plank, erected on the lower platform, being required to enable the mechanic to change his position to more conveniently obtain access to the work as it progresses from time to time, a staging so constructed occupying considerable time, and involving much labor in its erection, besides which all the tools and materials on one platform have to be removed to another platform every time a change in the height of the staging becomes necessary. To overcome the above-mentioned objections is the purpose of my invention, which consists in a traine-work, composed of a pair of standards connected by a horizontal transverse frame, upon which rest the ends of the plank which form the platform, upon which the materials and tools are deposited, and upon which the workmen stand while at work, the standards being provided with a series of notches, and the transverse frame with pawls, which engage therein, by which construction it is simply necessary to trip the pawls, by a cord or otherwise, to enable the workmen to readily lower the platform, a lever, in connection with an adjustable fulcrum, being employed for raising it, the notches being placed so near together that the platform may be conyeniently adj usted into various positions, differing very slightly in height from each other, the

materials and implements upon the platform remaining uninoved thereon during its adjustment.

To enable others skilled in the art to understand and use my invention, I will proceed to describe the manner in which I have carried it'out.

In the said drawings, A A represent two standards, each rising from the center of a base or foot piece, B, to which it is securely stayed by braces a a. The outer surface of each standard is provided with a series ot' notches, b I), separated about two inches from each other, and for a purpose to be presently explained. The two opposite side surfaces of cach standard are provided with vertical grooves c c, for the reception of the outer bent ends d (l of plates or straps O, two of which are secured to each of the opposite sides of each end of a frame, D, composed of two horizontal cross-beams, c f, connected by uprights E, the ends of the plank 4, for forming the platform, being intended to rest on the upper beam, e, by which construction the frame is free to slide up'and down within the stainlards, and the frame and its plates serve to prevent the standards from spreading apart. lVithin each upright E, at t', is pivoted a lever, G, of the forni seen in Fig. 1, the outer portion of the lever being bifurcated, and extending outside of and inclosing the upright portion of the frame D and the standard A, the outer ends of the bifurcations being united by a cross -piece, k, made separately from or 'in one and the same piece therewith, and resting in one of the notches b, the bifurcated lever, with its cross-piece k, serving as a pawl to prevent the frame D from slipping after being adjusted in position. The inner orlstraight portion of each lever has secured to its inner end a rope or cord, l, by pulling down on which the two pawls or cross-pieces k are brought rmly down on their notches, and bear forcibly in a lateral direction against their inclined surfaces, whereby increased security against the slipping down ofthe frame is insured, and an additional bond formed between the standards and the frame. The cord lis intended to be caught around a pin or cleat, m, to prevent the pawls from being accidentally thrown up and the consequent dropping ofthe frame. II is a cross-bar, extending horizontally from one standard to another, enlargements or projections 5, on the ends of the cross-bar, resting on the sides of the standards, each end of the cross-bar being provided with a hook, u, which fits into one of the notches b, and extends around to the opposite side of the standard, by which the cross-bar is securely held when suspended from the standards at any desired height, the object of the cross-bar being to provide a fulcrum for a lever, I, whose inner end p is to be inserted under the lower beam f when it is desired to raise the frame to elevate the platform, so as to enable the workman to have access to the work as it progresses, the pressure of the lever down on the cross-bar serving to increase instead of reduce the stability of the frame-work and platform while the latter is being raised. After being raised to the required height, the pawls drop'into their notches, and the sliding frame and platform are thereby held securely in place. When the platform is to be lowered, the frame D, at each end, is allowed to gradually slide down on its standards, by drawing up the inner ends of the levers by a cord, s, fastened thereto, and passing up over a pulley, t, hung in or to the lower side of the upper beanie, it being necessary rst to loosen the cord l, care being had to trip the levers only sufficiently to allow of the pawls successively engaging with the notches beneath, and the platform or staging, if heavily loaded, being eased in its descent by a counter resistance exerted by the lever I, with its inner end placed under the lower beam j', and having its fulcrum on the cross-bar H. Instead of the standards being provided with grooves c c, as shown, the latter may be dispensed with, and the standards be provided with projecting rails, as guides for the frame D to slide on, in which ease the latter would be provided with grooves, and the plates C would be dispensed with; but I prefer the construction first described.

From the foregoing, it will be seen that a staging constructed in accordance with my invention may be easily and quickly set up, and adjusted to various heights without the necessity of removing the load thereon; besides which it combines safety with strength and durability, andthe parts may be stowed away compactly when not in use, and can be transported from place to place with great facility.

Vhat I claim as my invention, and desire to secure by Letters Patent as an improvement in scaffolding, is*- 1. The pawl-clasp G, pivoted in the sliding frame D, in combination with the notched standards A A7 as and for the purpose set forth.

2. The cross-bar H, in combina-tion with the links n, lever I, and notched standards A A, substantially as described.

Vitness iny hand this 26th day of Febrn ary, A. D. IS7/l..

ALONZO S. DRISKO.

In presence ofl?. E. Tnscnnirzionnn, \V. J. CAMBRIDGE.

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