IMPROVEMENTS IN SHEER LEGS
Year: 1862

page_text: LETTERS PATENT to Charles Arthur Day and Thomas Summers, both of
Northam Iron Works, in the Town and County of Southampton, Engi-
neers, for the Invention of "IMPROVEMENTS IN SHEER LEGS."
PROVISIONAL SPECIFICATION left by the said Charles Arthur Day and
Thomas Summers at the Office of the Commissioners of Patents, with
their Petition, on the 18th July 1862.
We, CHARLES ARTHUR DAY and THOMAS SUMMERS, both of Northam Iron
Works, in the Town and County of Southampton, Engineers, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN SHEER LEGS,"
to be as follows:-
. Our Invention consists, first, in connecting the lower end of the back leg to
a screw, worm, and pinion and rack, hydraulic ram, or other like mechanical
contrivance for imparting to-and-fro motion to the back leg. The front legs
are of the ordinary construction, and work in the usual manner. Our Inven-
tion also consists in the employment of a load at the lower end of the back leg.
This loaded leg then acts to some extent as a back balance.
5
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Charles Arthur Day and Thomas Summers in the Great Seal
Patent Office on the 17th January 1863.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, CHARLES
ARTHUR DAY and THOMAS SUMMERS,: both of Northam Iron Works, in the
Town and County of Southampton, Engineers, send greeting.

page_text: WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Eighteenth day of July, in the year of our Lord One
thousand eight hundred and sixty-two, in the twenty-sixth year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto us
the said Charles Arthur Day and Thomas Summers, Her special licence, that
we, the said Charles Arthur Day and Thomas Summers, our executors, admi-
nistrators, and assigns, or such others as we, the said Charles Arthur Day and
Thomas Summers, our 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
SHEER LEGS," upon the condition (amongst others) that we, the said Charles
Arthur Day and Thoma's Summers, or one of us, our executors or administra-
tors, by an instrument in writing under our, or one of our, 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 we, the said Charles Arthur Day and Thomas
Summers, do hereby declare the nature of our said Invention, and in what
manner the same is to be performed, to be particularly described and ascer-
tained in and by the following statement thereof, reference being had to the
Drawings hereunto annexed, that is to say :-
Our Invention consists, first, in connecting the lower end of the back leg to
a screw, worm, pinion and rack, hydraulic ram, or other like mechanical con-
trivance for imparting to-and-fro motion to the back leg, in order that it may
act as a prop to the front legs when they are moved inwards, and as a guy to
them when they overhang outwards. The front legs are of the ordinary con-
struction, and work in the usual manner. Our Invention also consists in the
employment of a load at the lower end of the back leg; this loaded leg then
acts to some extent as a back balance.
In the accompanying Drawings we show the back sheer leg made to travel
to and fro by means of a screw and nut.
Figure 1 is a side elevation of ordinary sheer legs with our means of working
the back leg, partly in section; Figure 2 is a plan, and Figure 3 is a cross
section on the line x, x, of Figure 1.
A, A, are the front legs, working in the ordinary manner; B is the back leg,
connected at top to the front legs in the usual manner; C is a foundation of

page_text: masonry piles or other solid work on which iron plates D, D, are secured;
these plates are formed with a groove or channel on their inner sides for
receiving guide blocks fixed to trunnions a, a, as shewn in the transverse
section, Figure 3; 6 is a nut united to the trunnions a, a, through which a
screw E passes; this screw is free to revolve in eyes or bearings c, c, bolted to
or cast with the foundation; F, F, are wrought-iron plates bolted on to the
flanged plates D, D, to prevent the trunnions rising when the leg is made to
move to and fro along the channel in the plates D, D. In the Drawings wo
show the screw worked by steam engine, but it may be made to revolve by
hand or otherwise; f is a chain barrel for raising and lowering weights to be
lifted or moved by the sheers. When the back leg B is of wrought iron, as
we prefer it should be, we make it hollow and load it at bottom with iron burrs,
shot, or other weights.
We have not thought it necessary to show the back leg made to move to
and fro by rack and pinion, bydraulic ram, or other like mechanical contri-
vance, as the substitution of such other contrivance for a screw and worm will
be readily understood by any engineer charged therewith.
And having now described the nature of our said Invention, and in what
manner the same is to be performed, we declare that we claim,-
First, constructing and fitting the lower end of the back leg of sheers in
such manner that the same may be caused to travel to and fro, in order that
the said back leg may act as a prop to the front legs when moved inwards, and
as a guy to them when they overhang outwards, as herein-before described.
And, second, the employment at the lower end of the back leg of sheers of
a counterbalance weight, as herein-before described.
In witness whereof, we, the said Charles Arthur Day and Thomas
Summers, have hereunto set our hands and seals, this Thirteenth day
of January, One thousand eight hundred and sixty-three.