Improvements in Cramps for Joinery, Cabinet Making, and the like.
Year: 1896

page_text: Date of Application, 7th Oct., 1896
Complete Specification Left, 7th July, 1897--Accepted, 21st Aug., 1897
PROVISIONAL SPECIE
TION.
Improvements in Cramps for Joinery, Cabinet Making, and the like.
I, HARRY DUCKWORTH NEEDHAM, of 91, Moor Street, Burton on Trent, Foreman
Joiner, do hereby declare the nature of this invention to be as follows:-
This invention relates to improvements in the construction of cramps for use by
joiners, cabinet makers and the like, and has for its object to provide a simple
arrangement whereby such cramps may be rendered more effective and less liable
to injure the article held.
The cramp according to my invention is provided with a bar of T shape in
cross section, on the upper side of which a rack is formed. This rack does not
project from the surface but is sunk so that the sides of the bar project up to or
beyond the top of the teeth. This arrangement effectually prevents the teeth
scratching or otherwise damaging the articles held by the cramp
The sliding block I propose to employ is provided with a T shaped groove
fitting closely around the top of the bar, the shape of the groove preventing it
moving to either side, but allowing it to slide readily in a longitudinal direction.
Within the sliding block, a loose catch is employed the lower side of
which is provided with a rack which engages with the rack on the bar. This
catch is sufficiently loose to allow it along with the block to slide in one direction
along the bar, but by engaging with the lower rack prevents any return motion.
The catch is allowed considerable play within the block, the upper side being
sloping so that on its being pressed into the recess in the block the latter will
bear upon it and press it down upon the rack. The catch is provided with a slot
preferably parallel to the sloping upper surface, and a pin passes through the
block into the said slot, retaining the catch in the block, at the same time allowing
of considerable longitudinal motion. Owing to this arrangement by simply
pushing the block or foot towards the head of the cramp fitted at the other end of
the bar in the usual manner, the catch or wedge is raised clear of the rack, allowing
the foot or block to be pushed back.
Dated this 7th day of October 1896
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.
COMPLETE SPECIFICATION.
Improvements in Cramps for Joinery, Cabinet Making, and the like.
I, HARRY DUCKWORTH NEEDHAM, of 91, Moor Street, Burton-on-Trent, Foreman
Joiner, 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 improvements in the construction of cramps for use by
joiners, cabinet makers and the like, and has for its object to provide a simple

page_text: arrangement whereby such cramps may he rendered more effective and less liable
to injure the article held.
The cramp according to my invention is provided with a bar of T shape in
cross section, on the upper side of which a rack is formed. This rack does not
project from the surface but is sunk so that the sides of the bar project up to or
beyond the top of the teeth. This arrangement effectually prevents the teeth
scratching or otherwise damaging the articles held by the cramp.
The sliding block I propose to employ is provided with a shaped groove
fitting closely around the top of the bar, the shape of the groove preventing it
moving from either side, but allowing it to slide readily in a longi-
tudinal direction. Within the sliding block a loose catch or wedge is
employed the lower side of which is provided with a rack on the bar.
This
catch is sufficiently loose to allow it along with the block to slide in one direction
along the bar, but by engaging with the lower rack prevents any return motion.
The catch is allowed considerable play within the block, the upper side being
sloping so that on its being pressed into the recess in the block the latter will
bear upon it and press it down upon the rack. The wedge is provided with a slot
preferably parallel to the sloping upper surface, and a pin passes through the
block into the said slot, retaining one catch in the block, at the same time allowing
of considerable longitudinal motion. Owing to this arrangement by simply
pushing the block or foot towards the head of the cramp fitted at the other end of
the bar in the usual manner, the catch or wedge is raised clear of the rack, allowing
the foot or block to be pushed back.
In order that the invention may be more clearly understood, reference is had to
the accompanying sheet of drawings, in which Fig. 1 is a section of my improved
cramp, and Fig. 2 is an end view with the bar in section.
A is the bar T shape in cross section having the rack a at the upper side, this
rack being sunk below the upper surface of the bar. On this bar the sliding
block or jaw, B is placed, this jaw being formed with a central passage or groove
fitting the top of the bar and engaging with it. The sliding block is formed with
the recess b. Within this recess the wedge C is placed, the lower part of which
is forned with the rack c adapted to engage with the rack a. This wedge is
formed with the slot e parallel with its upper surface, the pin 61 belonging to the
sliding jaw passing through the slot. This arrangement allows the jaw to be
pushed forward towards the other end of the cramp, which is of any suitable
construction, having a moveable jaw with a screw adjustment. The racks by
engaging with each other prevent the jaw being pushed back and owing to the
wedge any pressure will only cause the racks to engage more firmly with each
other. The jaw can be easily moved back by pushing it slightly forward taking
the pressure off the wedge and permitting the latter to be pulled back. Owing
to the slot el being placed at an angle, the wedge is raised when pulled back
clearing the rack.
Owing to the bar being made without holes it is not weakened in any way, and
the arrangement can be used in any position, as there are no loose parts.
Having now particularly described and ascertained the nature of my said in-
vention, and in what manner the same is to be performed, I declare that what I
claim is:
(1) In an improved cramp for joinery and the like, the combination with a bar
provided with a rack,. of a sliding jaw fitted on the said bar, a wedge connected
to the said jaw, and a rack at the lower end of the wedge engaging with the rack
on the bar, substantially as and for the purposes specified.
(2) In an improved cramp for joinery and the like, the combination with a bar
having a rack at its upper side, of a sliding jaw fitted to the said bar, a recess in
the jaw, a wedge fitted in the recess, a slot and pin connecting the wedge and jaw
together, and a rack at the underside of the wedge engaging with the rack on the
bar substantially as described and for the purposes specified.

page_text: (3) In an improved cramp for joinery and the like, the combination with
a Tshaped bar having a suuk rack at its upper side, of a sliding jaw engaging
with the said bar, a recess in the jaw, a wedge fitting into the recess having a
rack at its under side, a sloping slot in the wedge and a pin passing through the
said slot, substantially as described and shown in the accompanying drawings,
and for the purposes specified.
Dated sh: 7.1 1
T
100%
GEO. H. RAYNER,
37, Chancery Lane, London, Agent for the Applicant.