US561263A - Georg lucas - Google Patents

Description

UNITED STATES PATENT OFFICE.

GEORG LUCAS, OF BERLIN, GERMANY.

SCAFFOLD.

SPECIFICATION forming part of Letters Patent No. 561,263, dated June 2, 1896. 7 Application filed December 14, 1895. Serial No. 572,172. (No model.)

To all whom, it may concern:

Be it known that I, GEORG LUCAS, painter, of No. 7 Fischerstrasse, Berlin, in the Empire of Germany, have invented an Improvement in scaffolds; and I do hereby declare the nature of this invention and in what manner the same is to be performed. to be particularly described and ascertained in and by the following statement.

This invention relates to a screw block or holdfast for securing boards or planks to the side rails or uprights of ladders for the purpose of erecting scaffoldings for painters, decorators, and other operatives employed in the building trade as a substitute for the scaffolding trestles or jacks now generally used. By means of the improved holdfasts two or more ladders may be connected by planks in such a manner that after these planks have been covered over with the necessary boards a scaffolding of considerable stability and strength is obtained as a result.

In the accompanying drawings, Figure 1 is a scaffolding erected with the assistance of my improved screw-holdfasts. Fig. 2 is a perspective view of an improved screw block or holdfast. Fig. 3 is a side view of the same as it appears when attached to the ladder. Fig. 4 is a modification of the same, adapted for use with ladders having half-circular section side rails or uprights.

The improved screw block or holdfast, which may be made of wrought-iron, caststeel, or the like, consists of a clamp a, which carries in its front part a screw 6, preferably fitted at its forward end with a claw or hook. The rear portion Zof the clamp a is secured to the side rail by means of two screws 61, one each side of the side rail, and having thumbnuts 0 screwed onto them and through the medium of an angle piece or shoe 1). The anglepiece I) is placed against one of the rungs of the ladder h, so that the clamp cannot slip off. In order to prevent any lateral displacement, another clamp 70 should preferably be provided, which in that case is so arranged that it embraces the beam of the ladder and may be firmly pressed against it by means of wooden wedges 'i or in any other convenient manner. Where the side rails of the ladder are of semicircular cross-section, the parts I and 70 should preferably be made half-round also, as illustrated in Fig. 4 of the drawings, so that they may correctly fit the side rail. After four or a greater number of such holdfasts have been screwed to the ladders on the required level or height, planks f, placed on edge,are inserted into the clamps a and tightly compressed and secured by means of the screw e. Upon these planks or rafters flooring-boards are laid to complete the scaffolding, which when so completed will prove very reliable and convenient. If desired, a further diagonal connection may be formed by suitable planks or boards or cross-pieces arranged to be, like the others, gripped by the clamps a.

Preferably the clamps a should be bent on one side in such a manner that the lower edge of the plank or board f which is inserted cannot shift or slide out of position.

Having now particularly described and ascertained the nature of my said invention and in what manner the same is to be performed, I declare that what I claim is- 1. Screw-boldfasts for securing planks or boards to the side rails of ladders for the purpose of erecting scaffoldings; the main feature of such holdfasts being a clamp, such as (1., having clamping-screws, 'such'as e, for the reception of planks or boards,such as f, placed on edge, and a movable shoe such as b, adapted to take up its position against the rungs h of the ladders and to be securely fixed in position by means of screws such as (1, so that the side rails of the ladders are firmly clamped between the shoe b and the clamp a.

2. In combination, a clamp for scaffolding adapted to ladders and the like comprising a clamp a, to receive and hold the side rails of the scafiold, a clamp 19 connected to the clamp a and adapted to secure the clamp a to the ladder-rail and a clamp is secured to the clamp a to hold the same from displacement at right angles to the clamp 22, substantially as described.

In witness whereof I have hereunto set my hand in presence of two witnesses.

, GEORG LUCAS.

Witnesses:

E. SOHMATOLLER, W. HAUPT.

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