IMPROVEMENTS IN SCREW CLAMPS OR CRAMPS FOR JOINERS' AND OTHER WORK
Year: 1862

page_text: LETTERS PATENT to Henry Fox Wells, Engineer, of Woodland House,
Prospect Row, Woolwich, in the County of Kent, for the Invention
of "IMPROVEMENTS IN SCREW CLAMPS OR CRAMPS FOR JOINERS' AND OTHER
WORK."
Sealed the 24th October 1862, and dated the 29th April 1862.
PROVISIONAL SPECIFICATION left by the said Henry Fox Wells at the
Office of the Commissioners of Patents, with his Petition, on the 29th
April 1862.
I, HENRY Fox WELLS, Engineer, of Woodland House, Prospect Row,
Woolwich, in the County of Kent, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN SCREW CLAMPS OR CRAMPS FOR JOINERS'
AND OTHER WORK," to be as follows:-
This Invention has for its object improvements in screw cramps or
clamps for the use of joiners, carpenters, boatbuilders, and others, and consists
of a bar or rod of metal of any desired length, according to the purpose
to which the clamp or cramp is to be applied; upon this rod or bar is
placed an arm, having an opening formed in it for one end of the rod or
bar to pass through; this arm is capable of sliding freely up and down on the

page_text: rod or bar, and at its other end a hole is formed, and tapped with a screw
thread to receive a thumbscrew, to which one of the two pressing surfaces of
the clamp or cramp is rivetted or otherwise fixed. The other pressing surface
may be formed upon the bar or rod by turning the end thereof up into the
shape of a hook, or two moveable arms carrying pressing surfaces may, if
preferred, be used. In these respects the screw clamp or cramp resembles
those heretofore used, but according to this Invention the arm or arms are
caused to be self-adjusting, so that wherever they are slidden upon the rod or
bar they are caused to remain by turning the thumbscrew, so as to make the
pressing surface carried thereby press upon the materials to be clamped, the
opening formed in the arm for the bar or rod to pass through having its two
interior sides (which press upon the front and back edges of the rod or bar)
formed obliquely instead of parallel to its outside edges, by which a powerful
nip of the rod or bar is obtained, and any further sliding of the arm prevented,
until by the backward movement of the thumbscrew the arm releases the
bar or rod from the nip, its interior sides being again allowed to assume a
more parallel position with the front and back edges of the bar or rod. In
some instances it may be found desirable to form notches, or teeth, or per-
forations in the bar, so that the inclined surfaces of the opening of the arms
may enter therein, and become fast by the working of the thumbscrew; thus
it will be seen that the holes in the rod or bar, hitherto used to receive pins
to hold the pressing arms in position are unnecessary, consequently the adjust-
ment of the clamp to various diameters is much more rapid and effectual.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Henry Fox Wells in the Great Seal Patent Office on the
29th October 1862.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
Fox WELLS, Engineer, of Woodland House, Prospect Row, Woolwich, in the
County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-ninth day of April, in the year of our Lord,
One thousand eight hundred and sixty-two, in the twenty-fifth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me, the
said Henry Fox Wells, Her special licence that I, the said Henry Fox Wells,
my executors, administrators, and assigns, or such others as I, the said Henry

page_text: Fox Wells, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times thereafter
during the term therein expressed, should and lawfully might make, use,
exercise, and vend, within the United Kingdom of Great Britain and Ireland,
the Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS
IN SCREW CLAMPS OR CRAMP3 FOR JOINERS' AND OTHER WORK,"
upon the
condition (amongst others) that I, the said Henry Fox Wells, my executors
or administrators, by an instrument in writing under my, or their, or one
of their hands and seals, should particularly describe and ascertain the
nature of the said Invention, and in what manner the same was to be
performed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the said
Letters Patent.
NOW KNOW YE, that I, the said Henry Fox Wells, do hereby declare the
nature of my said Invention, and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following state-
ment, that is to say :-
My Invention has for its object improvements in screw cramps or clamps
for the use of joiners, carpenters, boatbuilders, and others, and consists of a
notched or plain bar of metal of any desired length, according to the purpose
to which the cramp is to be applied, with one or more sliding arms formed in
the manner herein-after described. When one arm only is used, the end of
the bar is turned up to form an abutment or pressing surface, against.
which one side of the material to be clamped, cramped, or compressed, is
placed. The sliding arm is self-fixing by its peculiar form, and when placed in the
proper position upon the bar, forms the other abutment. An adjusting screw,
fitted either in the head of the bar or in the end of the sliding arm, or in
both, completes the cramp. In place of twining one end of the bar up, as
before described, a plain bar notched in opposite directions, and two sliding
arms may be added. The sliding arms are formed with a hole or slot at one
end, through which the bar can be passed. The arms can thus be moved
along the bar to any required position. When a plain surfaced bar is used;
these arms are self-fixing by the resistance offered by the material to com-
pression when the clamping screw is turned, and for light work, a plain bar, "
with an accurately fitting slot in the sliding arm will be found sufficient.
The arm and bar socket may be in one solid pieco of metal; or in two
parts fitted together with rabits or screw dowels; when made in two halves,
or parts, the screw dowels at the back of the, bar, when required, are

page_text: formed with heads projecting a little at the sides, so that they afford the means
of slightly diminishing the size of the socket, and thus tighten it upon the bar.
An opening of about 3 of an inch, being (cut when solid) left when formed
in parts for this purpose. For heavy work the arm is made solid; and is self-
fixing at and by the notches on the bar. In this case the slot is formed
rather larger than the bar, and in an oblique direction through the arm which.
stands at right angles to the bar when fixed. The arm can thus be inclined.
a little towards the head of the bar, or when two arms are used towards each
other. In this inclined position the arm or arms can be moved along the bar
freely over the notches, and when brought to the required position, and turned
square with or at right angles to the bar, the acute angle of the metal side
of the slot passes into one of the notches on the bar, and the arm, while it
remains at right angles to the bar, is thus rendered self-fixing; a screw or
wedge passing into one end of the slot may be added, if necessary.
The accompanying Drawing shews cramps constructed upon the principle
herein described.
EXPLANATION OF THE DRAWINGS.
Figs 1 & 2 shew a side view and section of a cramp for heavy work. a is
the bar; b, the sliding arm; c, c, the oblique slot; d, d, the notches in the bar;
and e the angle in the slot of the arm, which fixes it upon the bar when at right
angles thereto. The inclined position for sliding the arm is shewn at Fig. 2.
f is the abutment on the end of the bar, and g the corresponding abutment;
formed by the adjusting screw h in the arm; this screw may be placed in the
head if necessary. Fig. 3 shews a modification of the application of the
principle. is the bar, and j a sliding collar, in which the arm k is fitted,
so as to open upon a strong pin ; by slacking the screw m' the arm k can
be released from the notched bar, and the arm and collar be moved along the
bar as required, when the teeth n n, fitting into the notches o, o, fix it in the
desired position. Fig. 4 shews another modification of clamp. p is the bar,
and the sliding arm. r is an intermediate lever which carries the adjusting
screws and rotary abutment piece t. The bar is made rectangular, with
notches sunk at u, u,, but not extending from side to side.. Into these
notches one end of the intermediate lever passes when pressure is applied
by the screw; the other end of this lever rests upon the end v of the arm q,
and thus a double purchase is obtained for the abutment t, the slot in the arm
in this case, and also in that as shewn at Fig. 3, is the same size and shape as
the cross section of the bar, and traverses the arm at right angles..

page_text: Having thus described and illustrated my said Invention, and in what manner
the same may be performed, I hereby further declare that I do not confine the
application of the principle thereof to the forms and particular examples shewn
upon the Drawings, as both the forms & modes of applying the same may be
varied, but I include all such modifications as forming part of my said
Invention.
In witness whereof I, the said Henry Fox Wells, have hereunto set my
hand and seal this Twenty-ninth day of October in the year of our Lord
One thousand eight hundred and sixty-two.
HENRY FOX WELLS. (L.B.)