Improvements in and relating to Cramps for Screwing up Picture Frames and the like.
Year: 1899

page_text: Date of Application, 27th Nov., 1899
Complete Specification Left, 25th Aug., 1900-Accepted, 29th Sept., 1900
PROVISIONAL SPECIFICATION.
Improvements in and relating to Cramps for Screwing up Picture
Frames and the like.
I, HENRY LAWSON, of High Street, Pittenweem, Fifeshire, Joiner, do hereby
declare the nature of my invention to be as follows:-
This invention has reference to improvements in and relating to cramps for
screwing or tightening up picture frames and the like.
According to my improvements I use four radial arms which extend out to the
diagonal corners of the frame. Each diagonally opposite pair of arms are jointed
to a collapsible centre piece consisting of pairs of ribs which are in turn jointed
to centre pieces. These centre pieces are at right angles to each other on the
diagonally opposite pairs of arms and a screw spindle works through screw threaded
holes in the top pair and the plain lower end of spindle is held by a nut in a
slide in a fixed table, so that by turning this centre screw by hand the hinged
parts are opened out or collapsed and so the radial arms are drawn in or pushed
out. These radial arms are formed with slots, and screw threaded spindles project
down through same from triangular or like shaped paws or grippers at the corners
of the frames, and are tightened up by thumb nuts, so as to suit the different sizes
of frames.
Hated the 25th November 1899
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.
COMPLETE SPECIFICATION.
Improvements in and relating to Cramps for Screwing up Picture
Frames and the like.
I, HENRY LAWSON, of High Street, Pittenweem, Fifeshire, Joiner, do hereby
declare the nature of my invention and in what manner the same is to be per-
formed to be particularly described and ascertained in and by the following
statement in writing, reference being made to the accompanying drawings:
This invention has reference to improvements in and 'relating to cramps for
screwing or tightening up picture frames and the like, and by which they are
closely and firmly held while being glued, nailed, or wedged up.
And. in order that my said invention and the manner of carrying same into
practice may be properly understood I have hereunto appended a sheet of explana-
tory drawings in which Figure 1 is an elevation in perspective of my improved
cramp in a form specially suitable for window sashes, light door frames and
CD977

page_text: mitred frames. Figures 2 and 3 are a detached elevation and plan view respec-
tively to an enlarged scale of one of the paws or grippers as suitable for picture
frames. Figure 4 is a detached view of a modified form of the radial arms and
operating fittings suitable for mitred frames, window sashes and the like where
no inside framework can come in contact with operating fittings; and Figures 5
and 6 are views corresponding to Figures 2 and 3 of one of the grippers as
suitable for sash frame work and the like. While Figure 7 is a detached view
showing how extension links may be applied to the slotted radial arms.
Referring to these drawings:-
-
According to my improvements, I use four radial arms a a and a¹ a¹ which
extend out beyond the diagonal corners of the frame A. Each diagonally opposite
pairs of arms a a and a a¹ are jointed to a collapsible centre piece consisting of
pairs of ribs bb and 61 61 which are in turn jointed to centre pieces c c and c¹ c¹.
These centre pieces may be at right angles to each other on the diagonally
opposite pairs of arms a a and a¹a and a spindle d with right and left handed
screw threads on its upper and lower halves respectively works through threaded
holes in the centre pieces c and c', so that by turning this centre screw spindle d
by the handled the hinged parts 6 1 are opened out or collapsed and so the
radial arms a al are drawn in or pushed out, the whole being carried on a suitable
frame or table B. These radial arms a a¹ are formed with slots a³, and screw
threaded spindles el project down through same from triangular or like shaped
paws or grippers e at the corners of the frames A, and are tightened up by thumb
nuts e² so as to suit the different sizes of frames A. As shown in Figure 7 the
radial arms a or al may be lengthened out by extension links a fixed on end of
each arm by thumb screws at when treating specially large frames. For window
sashes and the like, the screw spindle is turned by a cross bar as shown at d
in Figure 4 at opposite end of spindle d to the crank handle d, shown in Figure 1,
and the dogs or grippers are preferably made of the form shown in Figures 5
and 6 with crescent base having vertical end projections .
In the arrangement shown in Figure 4, which is specially suitable for picture
frames, the slotted radial arms a a¹ have not a long knee piece but are connected
at the end of the straight piece, to the rib links b b¹, and a collar f is fitted on
screw threaded spindle d and slides in a slotted bar B2 in frame work or table B
so as to be made adjustable when grippers come in contact with table, and a cross
bar is fitted on lower end of spindle d for turning same to operate the radial
arms a a¹.
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:-
First. Cramps for screwing up picture frames and the like, consisting of radial
slotted arms connected to rib pieces which are in turn connected to centre pieces
operated by a screw threaded spindle, substantially as herein described in refer-
ence to and shown in the accompanying drawings.
Second. The arrangement in combination, of the parts of cramps, sub-
stantially as herein described in reference to and shown in the accompanying
drawings.
Dated the 0141
1000
W. R. M. THOMSON & Co.,
96, Buchanan Street, Glasgow, Agents.