US1003407A - Sectional scaffold. - Google Patents

Description

V. ABRAMS.

SEGTIONAL SGAFI'OLD.

APPLICATION FILED mm. a, 1909.

3 SHEETS-SHEET 1.

Patented Sept. 19, 1911.

V. ABRAMS.

SEGTIONAL SOAFFOLD.

APPLICATION FILED DEC. 3, 1909.

Patented Sept. 19, 1911.

. F, 4 V j/CI gEETB-BHEBT'Z. 9 4 g 4? Q N v. ABRAMS.

' SEGTIONAL SGAFFOLD.

APPLICATION FILED DEG. 3 1909.

Patented Sept. 19,1911.

3 SHEETSSHEET 3.

UNITED STATES PATENT OFFICE. VICTOR ABRAMS, OF CHICAGO, ILLINOIS, ASSIGNOR T GIANT LADDER C0., L JHICAGO,

' ILLINOIS, A. CORPORATION OF ILLINOIS.

\ SECTIONAL SCAFFOLI).

To all whom it may concern:

Be it known that I, VICTOR ABRAM-S, citizen of the United States, residing at Chicago, in the county of Cool; and State of Illinois, have invented certain new and use ful Improvements in Sectional Scafi'olds; and I do hereby declarethe following to be a. full,.clear,,and exact description of the invention, such as will enable others skilled in the art towhich it appertains to make and use the same. 1

This invention relates to a novel constructionin a sectional scaffold, the object being to provide a scaffold of thischaracter which is very strong, durable and e'flicient and is easily erected and razed and which is safe, and consists in the features of construction and combinations of parts hereinafter fully described and claimed. V

In the accompanying drawings illustrating this invention: Figure -1 is a perspective view of a scaffold constructed in accordance with my invention. Fig. -2 is an end elevation of the same. Fig. 3 is a fragmentary vertical sectional view of a scaffold constructed in accordance with my invention. I Fig. 4.- is a fragmentary, end elevation of the. same. Fig 5- is a view similar to Fig. -1- showing the opposing ladders one of same being shown in side elevation. Fig. 6 is a fragmentary detail sectional view showing the joint between two super-imposed side rails of ladders comprising the u rights of the'scaffold. Fig. -7 is a ragmentary detail section showing the lower end of one of the side rails of a ladder. Fig. 8 is a fragmentary detail plan view showing the. fastening device employed for securing braces to rungs of the ladder sections Fig. --9'- is a fragmentary detail view in elevation showing one of the cross-pieces secured to v the side rail of one of the ladders. "Fig.

-10- is a plan section on the line 110-10 of Fig. 9 Fig. 11 is a sectional view on the line 1111 of Fig. -9-- Fig. -12 is a plan section of the scaffold set up ready for use. Fig. 13- is a detail new in elevation of a locking device employed as a part of one of the fittings.

Sectional scaffolds made up of interfitting ladders in connection with braces connecting the same in arallel and maintaining them rigidly uprlght are quite commonly employed but in almost all instances the1up- Specification of Letters Patent. Patented Sept. 19, 1911. Application filed December 3, 1909. Serial No. 531,279. 7 I I per ladder sections are supported exclusively on the rungs of the lower ladder sections, the joints being effected in various ways.

In some instances the side rails of the upper ladder sections are supported directly upon the side rails of the lower sections so that the load is transferred continuously from the uppermost to the lowermost section through the side rails exclusively.

My said sectional scaffolding belongs to the last-named class, the improvements madev by me relating more particularly to certain details of construction whereby the strength, rigidity and reliability of the scaffolding is greatly increased without increasing the weight or cost of construction, of the same.

The said scaffolding is composed of a plurality of ladders of equal length and having 75 preferably the same number of rungs spaced equi-distantly, the upper and lower rungs of each section being disposed exactly onehalf the distance from the ends of they side rails as the distance between centers of adthe remaining rungs. This feature is, I 'believe, novel and constitutes an important feature of the invention.

The lower ends of the side rails 1 of each ladder are longitudinally slotted as at 2 and bound with a strap .3 of flat steel or 1 other suitable metal suitably secured to the edges of said side rail. The upper ends of said side rails 1 are similarly bifurcated as'at4 and almost entirely surrounding and inclosing said upper end portion is a sleeve 5 ofsteel or the like which is substantially rectangular in plan section but is preferably slotted as at 6 on the inner face of the side rail, said sleeve being suitably secured to said side rail in any well-known manner. i

The free flan es 7 on either side of the slot 6 are preferafilysecured together by means of the cross-pieces 8 riveted thereto thereby preventing expansion of saidsleeve.

The top and bottom rungs of the ladders extend into and are secured within the bifurcated end portions of said side rails 1 1n any suitable manner. Pivotally secured to the upper end portion of-one of the flan es 7 ofthe sleeve 5 is an inverted hook 9 which a projection on the opposite flange 7 of said sleeve to confine the rung 11 of an upper section and thus prevent separation of a supported section from that upon which it is supported. The sections are thus securely locked together vertically. V

The bifurcation of the upper and lower ends of the side rails 1 of the ladders serves to prevent the same when swelling .under the influence of moisture exerting a sufficient the size of the interfitting parts and thereby prevent or render more-difficult the proper .assembling of the ladders t 'form a, scaffold.

In building the scafl old the ladders are preferably set up to constitute the four corn'ers of a square,'the side rails and rungs \thereof being mamtained parallel with each other. The corner uprights-thus constituted 'are secured together by means of knee braces) 13 and cross-pieces '14,- the' former being equipped at the ',free ends of their com-'" ponent members with suitable devices for firmly engaging the rungs of opposed ladders, while the latter are provided with devices for engaging the side rails 1 of the ladders and also the rungs thereof as is hereinafter further explained in detail as follows: The-lmee braces 13 comprise each a horizontal bar 12 equipped on its lower edge and at both ends with a lockin device consisting of a casting 15 provide in its lower face with a recess 16 to receive a rung of a ladder. The said casting 15 is preferably stepped and is provided with threaded openings through which the threaded ends of the bolts 17 pass to secure said casting to said bar. The free ends of the bolts pass through longitudinal slots in the flanges of a Z-shaped member 18, the latterbeing held in place by means of the nut 19 and butterfly or thumb nut 20. The said Z-shaped member 18 may be moved longitudinally so that one end of the same covers the recess 16, as shown in Figs. 1 and -3, and may be moved rearwardly a distance suflicient to undercover said recess to permit a rung to be withdrawn from the same. The braces 21 are similarly equipped with said locking devices but the latter are mounted on the upper endge of said braces 21 instead of the lower so that after mounting the bar 12 'in position the said braces 21 may be swung upwardly so as to, throw the said locking devices into engagement'with the rungs of the ladder sections.

The cross or X-braces consist of oppo 'sitely inclined bars disposed between opvposin side rails of adjacent ladders and each t ereof is equipped at its ends with an engaging device which consists'of a J-shape'd er 22 provided with a flange 23 resting against aside face of the bar to which it is secured. The said' member '22 is pro-- vided free flange with a slot 24 in which a rung of the ladder is received. A Z-shaped member 25 is secured through one of its flanges to the opposite face of the bar 28 entering the mouth of the slot 24 in the pressure on'the sleeve 5 'or strap .3 to vary member 22 thereby preventing rotation-of said member 25 when saidthumb nut 27 is drawn up to secure said members firmly in position. The engagement of therung with the walls of the slot 24 in the member 22 will obviously prevent longitudinal move- 0 it'is-desired the said cross braces may be arranged-14in pairs pivotally secured together between'their ends but owing to their rela tively great length and consequent difliculty of handling it is more advisable and convenient to maintain said bars separate from each other.

In erecting a scaffold by means of the sectional ladders it is'fprimarily necessary that the lowermost or base sections shall be supported at a uniform level or at different levels corresponding in variations in elevation by 'thedistance between centers of,-the rungs of the sections or twice, three times,

-etc., the last-named distance, it being essential that those rungs of all ladders to which the knee braces 13 are to be secured shall be disposed in the same horizontal plane so that flooringv supported on the bars 14: or

scafi'olds 29 of greater width and strength corresponding in shape with said knee braces shall be level. After having set up two pairs of ladders each of -which is secured together by means of the knee braces 13, the said pairs are connected together by means of the diagonal braces 14 secured at opposite ends to o posing side rails of opposed ladders at di erent elevations. A rectangular structure is thus formed which may be extended upwardly to any desired height with ease :and rapidity and which may be extended laterally in all directions to cover any desired area.- The side rails of all up er ladder sect-ions rest directly upon the side rails of the nekt lower sections to which they are locked by means of the while the pivoted legs thereo engage the rungs of the supporting sections. The said knee braces 13, cross-braces 14 and scaffolds 29 serve to maintain all fiprights rigidly in vertical position and prevent any deflection thereof. The scaffolds 29 may be described as comprising a pair of knee pieces disposed parallel With each other and the several opposed parts of which are secured together by means of rungs of less length than the rungs of the ladders.

Flooring may be supported on the scaffolds 29 at any desired elevation and said scaffolds may be disposed at several different elevations in the scaffold so as to permit several gangs of men to Work at different elevations as in painting and decorating Walls of halls, churches, theaters, etc., thus enabling lathing, plastering and decoration of Walls and ceiling to be carried on simul taneously.

I claim as my invention:

1. Sectional ladders each equipped at one end of each of its side rails with sleeves embracing and secured to the same and projecting beyond the ends thereof, U-shaped straps embracing and securedto the other ends of the side rails of said ladders, said projecting end portions of said sleeves adapted to receive the bound end portions of companion ladders to join the same, both ends of said side rails being longitudinally slotted to permit swelling thereof Without exerting undue pressure on the members embracing the same.

2. Sectional ladders having rungs spaced equi-distantly from each other, the end rungs of each ladder spaced one-half the distance from the adjacent ends of the side rails as the distance between adjacent rungs, sleeves embracing and secured to one end of each of the siderails of said ladders and projecting beyond the ends thereof, said sleeves adapted to receive the other ends of the side rails of companion ladders to join the same, there being slots in the opposed Walls of the sleeves of each ladder adapted to receive a rung of the companion ladder, and latches spanning said slots and operatively engaging said rung to hold said ladders against separation.

In testimony whereof I have signed my name 'in presence of two subscribing wit-- nesses.

. VICTOR ABRAMS. Witnesses:

RUDOLPH WM. Lo'rz, E. -H. MACDOWELL.

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