An Improved Window Jack or Scaffold.
Year: 1892

page_text: Date of Application, 3rd June, 1892
Complete Specification Left, 2nd Mar., 1893-Accepted, 22nd Apr., 1893
PROVISIONAL SPECIFICATION.
An Improved Window Jack or Scaffold.
I, GEORGE DAVIES, of Maidenhead Inn, Lyonshall, Kington, in the County
of Hereford, Machinist, do hereby declare the nature of this invention to be as
follows:-
•
My invention relates to improvements in portable jacks or scaffolds used by
window-cleaners, painters, decorators and others for affording ready access to the
exteriors of windows.
According to my invention I employ the ordinary plank and struts but I make
the hold-fast adjustable by connecting it to a sliding-block carrying a catch-lever
designed to engage with holes in the plank. In connection with the hold-fast I
employ a clamping-block which is carried by a screw passing through the sliding-
block to which the hold-fast is connected, the said screw being so arranged that
after the hold-fast has been adjusted by means of its catch-lever it may be securely
held in position by tightening the clamping-block by means of the screw.
I also arrange in conjunction with the hold-fast a sliding-catch or bolt adapted to
engage beneath some projecting part of the window-frame to afford an additional
security against the slipping of the scaffold.
Dated the 3rd day of June 1892.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improved Window Jack or Scaffold.
I, GEORGE DAVIES, of Maidenhead Inn, Lyonshall, Kington, in the County
of Hereford, Machinist, 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 :-
My invention relates to improvements in portable jacks or scaffolds used by
window-cleaners, painters, decorators and others for affording ready access to the
exteriors of windows.
According to my invention I can employ the ordinary plank and struts but I
make the hold-fast adjustable by connecting it to a sliding block carrying a catch-
lever designed to engage with holes in the plank. In connection with the hold-fast
I employ a clamping-block which is carried by a screw passing through the sliding-
block to which the hold-fast is connected, the said screw being so arranged that
after the hold-fast has been adjusted by means of its catch-lever it may be securely
held in position by tightening the clamping-block by means of the screw.
I also arrange in conjunction with the bold-fast a sliding-catch or bolt adapted to
engage beneath some projecting part of the window-frame to afford an additional
security against the slipping of the scaffold.
To enable my invention to be fully understood I will describe how it can be
carried into practice by reference to the accompanying drawings, in which :-
Figure 1 is a longitudinal elevation of a window jack or scaffold constructed
according to my invention, and
Figure 2 is a plan of the same.
mass contion on the crooked line A B of Figure 1.

page_text: Figure 5 is a longitudinal elevation and,
Figure 6 a plan of another part of the jack.
Similar letters in all the figures indicate similar parts.
a is the ordinary plank and b, c are the struts which form by preference with
slots d and respectively, the struts c being hinged at to the plank a and a
clamping bolt g (provided with a nut h) passing through the slots d, e. By this
means the strut c can be raised or lowered in case there should be any obstacle in
the way of its resting against any part of the wall. is the foot rest which is
fixed to the struts b, and j is the usual back rest which I mount upon the hinge
pins of the struts c.
The struts may however be of ordinary construction, that is to say, the struts c
may be unadjustable.
is the hold-fast, and is the sliding block to which I connect it through the
medium of the clamping block and screw hereinafter described in order to render
it adjustable; m is the catch-lever jointed spring-wise to a fixed handle n and to a
bar o, carrying pins designed to engage in holes q made in metal plates or strips
and entering the plank a. The block is provided with rollers to diminish friction
and with guiding splines or keys t, t (Figure 4) moving in rebates or grooves u
beneath the metal strips r.
vis the clamping-block to which the hold-fast k is fixed, and w is the screw which
carries the said clamping-block, such screw engaging with a nut in the block and
being provided with a hand wheel a for turning the same.
y is the sliding-catch or bolt adapted to engage beneath a projecting part, such
as y, of the window-frame (Figure 1) to afford additional security against the
slipping of the scaffold and which I employ in conjunction with the hold-fast k, the
said catch or bolt being formed with slots z, z¹ as shewn in Figure 1. It is adapted
to be raised, lowered and moved longitudinally by means of a clamping bolt a
(provided with a winged nut 6¹ and movable in the slot z and in a slot c¹ in a
frame d¹) in conjunction with a pin or pivot el carried by a screw f1 and passing
through the slot z. The screw is raised and lowered by a nut g₁ adapted to be
revolved in the frame d by means of a handle /².
, Figures 1, 2, 5 and 6, is a plate adapted to slide beneath the plank a and
having a downwardly turned end j₁ and a handle whereby it can be pulled
out or pushed inwards until its end abuts against the wall, when being clamped
between the block v and the plank a it forms an additional bearing for the
apparatus.
To fix the jack or scaffold in position upon a window-sill as indicated by the dot
and dash lines in Figure 1, the struts c having been adjusted the plank k is placed
across the window-sill with the struts c resting against the outside of the wall in
the usual manner. The spring catch-lever m is then operated by grasping the
same together with the fixed handle n so as to withdraw the pins p from the holes q.
The block is then moved along the plank a until the hold-fast k abuts against the
projection y or other part of the inner side of the wall, the lever m is released
when the pins p will enter the holes q and secure the block from moving longi-
tudinally. The plate is placed with its end j¹ against the wall and the screw w
is turned so as to clamp the block 1, plank a, plate and block v together. The
sliding-catch or bolt y is then placed with its inner end under the projecting part y¹
of the window-frame and secured by screwing up the bolt a' and nut g¹.
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. A window-jack or scaffold having a hold-fast made adjustable by connecting
it by means of a clamping-block and screw to a sliding block carrying a catch-
lever designed to engage with holes in the plank, substantially as hereinbefore
described.
2. The combination with a window-jack or scaffold having a hold-fast made

page_text: adjustable in the manner referred to in the preceding claiming clause of a sliding-
catch or bolt adapted to engage beneath some projecting part of the window-frame,
substantially as and for the purpose herein before described.
3. The combination with a window jack or scaffold constructed as referred to in
Claims 1 and 2 of the sliding plate i¹ and adjustable struts c substantially as and for
the purpose set forth.
4. The manufacture and use of the improved window jack or scaffold herein before
described and illustrated in the accompanying drawings.
Dated the 2nd day of March 1893.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.