Improvements in Mitre Cramps.
Year: 1892

page_text: Date of Application, 27th July, 1892
Complete Specification Left, 27th Apr., 1393-Accepted, 10th June, 1893
PROVISIONAL SPECIFICATION.
Improvements in Mitre Cramps.
I, GEORGE GREENWAY, of 20 Upper Webster Street, Aston Newtown, in the
County of Warwick, Architect, do hereby declare the nature of this invention to
e as follows:-
This invention relates to the manner in which I construct and arrange cramps
or use upon picture frames, doors, tables or other similar articles in which mitre
corners are employed, whereby 1 am enabled to cramp or hold together the four
corners or mitres by one setting of my improved appliance, thereby obviating the
trouble at present occasioned when a cramp is applied in the usual ordinary manner
to one corner or mitre only.
In carrying my invention into effect, I construct my improved cramp in the form
of a central bar or frame to which are attached four pivotted arms, having a screw
or system of toggle levers for drawing these arms together for the purpose of
enabling them to simultaneously secure the four corner pieces.
The central bar I construct preferably of metal, of channel or flange girder
section, and of a length suitable for the frame or work upon which the cramp is to
be chiefly employed. Within the flanges or upon the bed of my metal frame,
I mount a sliding plate having a slot or series of holes to work upon a pin or
securing nut and bolt which connect the sliding plate to the frame at any required
point. Upon one end of this sliding plate I mount two arms upon a central pivot
as a hinged joint, or upon a pair of pivots, one arm passing to one mitre or corner,
and the other to the opposite corner. Upon each of these arms I fix my mitre
block or corner piece having upon its outer edges suitable flanges or projections
for securing the adjacent pieces of timber or other material required to be
"mitred; the flanges or projections being arranged at the opposite corners in a
manner to permit of access to the corner or outer and inner joints of the timber
edges. The mitre block I provide with a projecting stud or pin for working in a
hole arranged or formed within the arm so that the block may automatically adjust
itself when the arm is pulled. I prefer to form a projecting stud or pin upon each
mitre block with a head, so that it may pass through an enlarged hole within the
arm, and then be slipped along into a smaller hole of a size suitable to the neck
pin while the larger head projecting below secures the block upon the arm.
I form or arrange a number of holes and slots along the arm to suit any varying
size or width of frame which is to be "mitred," each arm being identical in shape
and arrangement. Upon the opposite end of my central bar I secure another
sliding plate upon which I mount two arms in a manner similar to that hereinbefore
described for the other arms; but into this sliding plate 1 secure or form a pro-
jecting nut or block to receive a nut, so that a screw which I carry from a head-
stock fixed upon the centre of the frame when turned passing through the nut will
draw the slide along. The screw headstock 1 rivet or attach to the central bar or
frame in any ordinary manner the screw being shouldered down or permitted to
pass through the headstock freely, with a collar upon the outer end to secure it in
position; while upon
the inner end or opposite side of the headstock, I mount a
turning lever or bar, passing through a hole running right through the screw.
Instead of a turning handle or bar I sometimes arrange a small hand wheel for
drawing the slide along when turned.
When dispensing with the screw I sometimes arrange a system of toggle levers
from one sliding frame to the other; so that when the levers are manipulated the
double armed frames are brought together from cramping four corners or mitres.
I do not limit the application of my invention to frames made from any particular

page_text: metal, or to any form of jointed arms; but I modify the material together with its
shape and configuration to suit any particular requirement.
I do not limit the application of my invention to doors or frames having mitre
corners but employ my improved cramps upon the construction of tables or upon
any article required to be drawn together at the four corners in the course of
construction.
Dated this 26th day of July 1892.
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Mitre Cramps.
1, GEORGE GREENWAY, of 20 Upper Webster Street, Aston Newtown, in the
County of Warwick, Architect, 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 the manner in which 1 construct and arrange cramps
for use upon picture frames, doors, tables or other similar articles in which mitre
corners are employed, whereby I am enabled to cramp or hold together the four
corners or mitres by one setting of my improved appliance, thereby obviating the
trouble at present occasioned when a cramp is applied in the usual ordinary manner
to one corner or mitre only.
In the three accompanying sheets of explanatory drawings,
Figure 1 is a plan of my improved cramp shown in position upon a picture frame,
and Figure 2 is an end elevation of the same.
Figure 3 is a plan of my cramp with channel shaped levers and modified form
of slide.
Figure 4 is a sectional elevation of the same.
Figure 5 is a plan of my cramp when employed for securing the corners of a
square frame X.
Figure 6 is a plan of my cramp applied to a semi-circular frame Y.
Figure 7 is a plan of my cramp when applied to a circular frame Z.
In carrying my invention into effect when constructing my improved cramp as
illustrated in Figures 1 and 2, 1 arrange a central bar or frame A to which are
attached four pivoted arms B C D E having a screw For system of toggle levers
for drawing these arms together for the purpose of enabling them to simultaneously
secure the four corner pieces b c d e.
The central bar A I construct preferably of metal of channel or flange girder
section, and of a length suitable for the frame W or work upon which the cramp is
to be chiefly employed. Within the flanges or upon the bed of my central
frame A, mount a sliding plate G having a slot or series of holes to work
upon a pin or securing nut and bolt which connect the sliding plate to the frame
at any required point, or having a pin such as y to pass through the slot a
within the frame bar A with a nut g' to secure it in any desired position.
Upon one end of this sliding plate GI mount two arms B C upon a central
pivot Kas a hinged joint, or upon a pair of pivots, one arm passing to one
mitre or corner and the other to the opposite corner. Upon each of these arms
I fix my mitre block or corner piece be having upon its outer edges suitable
flanges bc (Figure 3) or projections for securing the adjacent pieces of timber
or other material required to be "mitred; the flanges or projections being
arranged at the opposite corners in a manner to permit of access to the corner
or outer and inner joints of the timber edges as shown in Figures 3 and 4.
mitre blocks bc I provide with projecting studs or pins for working in holes
arranged or formed within the arms so that the block may automatically adjust
وو
The

page_text: itself when the arm is pulled. I prefer to form a projecting stud or pin upon each
mitre block with a head, so that it may pass through an enlarged hole within the
arm, and then be slipped along into a smaller hole of a size suitable to the neck
pin while the larger head projecting below as shown in Figure 3 secures the
block upon the arm; I form or arrange a number of holes and slots L along the
arm to suit any varying size or width of frame which is to be "mitred," each arm.
being identical in shape and arrangement.
Upon the opposite end of my central bar I secure another sliding plate H upon
which I mount two arms D E in a manner similar to that hereinbefore described
for the other arms; but into this sliding plate I secure or form a projecting
nut or block to receive a nut, so that a screw F which I carry from a head
stock M fixed upon the centre of the frame, when turned and passing through
the nut will draw the slide H along. The screw head stock M I rivet or
attach to the central bar or frame A in any ordinary manner, the screw F being
shouldered down or permitted to pass through the headstock freely, with a collar
on the outer end to secure it in position; while upon the inner end or opposite side
of the headstock, I sometimes mount a turning lever or bar, passing through a hole
running right through the screw. Instead of a turning handle or bar I sometimes.
arrange a small hand wheel O for drawing the slide along when turned.
When dispensing with the screw I sometimes arrange a system of toggle levers
from one sliding frame to the other, so that when the levers are manipulated the
double armed frames are brought together from cramping four corners or mitres.
I do not limit the application of my invention to frames made from any particular
metal or section of metal, or to any form of jointed arms, but I modify the material
together with the shape and configuration of the parts to suit any particular
requirement.
I do not limit the application of my invention to doors or frames having mitre
corners but employ my improved cramp upon the construction of tables or upon
any article required to be drawn or held together in the course of construction.
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. The construction of cramps having arms or jointed levers arranged about a
central frame or bar upon which a screw and nut is mounted for opening and closing
the arms substantially as and for the purposes hereinbefore described.
2. The construction of pivoted or swivelling mitre pieces or blocks such as a b c d
for use upon binding cramps, such blocks having flanged projections for fitting
against the sides or ends of the pieces or members which are to be joined together
substantially as hereinbefore described and as illustrated in the accompanying
drawings.
3. The combination and arrangement of cramps for binding or securing frames
and the like together, substantially as herein before described and as illustrated in
the accompanying drawings.
1202
MARKS & CLERK,
13, Temple Street, Birmingham, Agents for the Applicant.