An Improved Screw Holdfast for Securing Boards or Planks to the Side-rails or Uprights of Ladders in Erecting Scaffoldings.
Year: 1895

page_text: Date of Application, 23rd Nov., 1895-Accepted, 28th Dec., 1895
COMPLETE SPECIFICATION.
An Improved Screw Holdfast for Securing Boards or Planks to the
Side-rails or Uprights of Ladders in Erecting Scaffoldings.
I, GEORG LUCAS, of No. 7 Fischerstrasse, Berlin, in the Empire of Germany,
Painter, 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.
Figure 2 is a perspective view of an improved screw block or holdfast;
Figure 3 is a side view of the same as it appears when attached to the ladder;
Figure 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,
cast steel or the like, consists of a clamp a which carries in its front part a screw e,
preferably fitted at its forward end with a claw or hook. The rear portion / of
the clamp a is secured to the side-rail by means of two screws d one each side of
the side-rail, and having thumb nuts c screwed on to them, and through the
medium of an angle piece or shoe b. The angle piece is placed against one of
In order to prevent
the rungs of the ladder h, so that the clamp cannot slip off.
any lateral displacement, another clamp k should preferably be provided, which,
in that case, is so arranged that it embraces the beam of the ladder and may he
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 semi-circular cross section, the
parts and should preferably be made half-round also, as illustrated in Figure 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 inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. Screw holdfasts for securing planks or boards to the side-rails, of ladders for

page_text: the purpose of erecting scaffoldings; the main feature of such holdfasts being a
clamp, such as a, 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 d, so that the side-rails of the ladders are
firmly clamped between the shoe 6 and the clamp a.
2. In the screw holdfasts referred to in Claim 1, the provision of a lower
clamp k, adapted to surround or embrace the side-rail of the ladder and to be
securely fixed in position by means of keys, or wedges, or in any other convenient
manner, for the prevention of lateral displacement.
Dated this 23rd day of November 1895.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.