IMPROVEMENTS IN HYDRAULIC MACHINES FOR SHEARING, STAMPING PUNCHING AND SUCH LIKE OPERATIONS
Year: 1882

page_text: LETTERS PATENT to Ralph Hart Tweddell of No 14 Delahay Street
Westminster in the County of Middlesex for an Invention of IMPROVEMENTS
IN HYDRAULIC MACHINES FOR SHEARING, STAMPING PUNCHING AND SUCH
LIKE OPERATIONS
PROVISIONAL SPECIFICATION left by the said Ralph Hart Tweddell
at the Office of the Commissioners of Patents on the 26th September 1882.
RALPH HART TWEDDELL of N° 14 Delahay Street Westminster in the County
of Middlesex "IMPROVEMENTS IN HYDRAULIC MACHINES FOR SHEARING, STAMPING
PUNCHING AND SUCH LIKE OPERATIONS,"
My Invention relates to the construction and arrangement of hydraulic machines
for shearing stamping punching and such like operations, the chief objects which
I have in view being to provide a stop for the stroke of the machine, to maintain
the tool on the moving part constantly in its proper position relatively to the tool
on the stationary part, to provide against lateral strains resulting from the action
of the tools, and to enable the operator to have an uninterrupted view of the
tools as they approach the work. For this purpose I form in the framing of the
machine a cylindrical cavity in which a hydraulic piston works vertically, and
below this cylindrical cavity I form eccentric with it a cylindrical guide for a ram
head projecting eccentrically from the piston, which ram head carries the moving
tool. The eccentricity of the guide relatively to the cylinder prevents the head
from turning round and thus the tool is prevented from deviating angularly from
its true position. The guide, which I make of considerable depth particularly at
the back, supports the head and tool against such lateral strain as results from
shearing. Also as the head has its axis in front of the axis of the cylinder, the
tool carried by the head is near the front of the machine so that the operator's
view of it is comparatively uninterrupted by any projecting parts of the machine.
The cylinder in which the hydraulic piston works is closed at the top by a tightly
fitting cover which may have formed in it a small cylinder fitted with a piston

page_text: attached to the main piston for the purpose of drawing the latter up after it has
made its down stroke. The draw back cylinder may be arranged in or on the
framing under the main piston, with a plunger pressing against that part of the
underside of the main piston which extends beyond the eccentric guide. The stroke
of the piston is stopped by this part of it coming down on the bottom of the
cylindrical cavity.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said Ralph Hart Tweddell in the Great Seal Patent Office on the
24th March 1883.
RALPH HART TWEDDELL of N° 14 Delahay Street Westminster in the County
of Middlesex "IMPROVEMENTS IN HYDRAULIC MACHINES FOR SHEARING, STAMPING,
PUNCHING AND SUCH LIKE OPERATIONS
"
My Invention relates to the construction and arrangement of hydraulic machines
for shearing, stamping, punching and such like operations, the chief objects which
I have in view being to provide a stop for the stroke of the machine, to maintain
the tool on the moving part constantly in its proper position relatively to the tool
on the stationary part, to provide against lateral strains resulting from the action
of the tools, and to enable the operator to have an uninterrupted view of the tools
as they approach the work. For this purpose, I form in the framing of the
machine a cylindrical cavity, in which a hydraulic piston works vertically, and
below this cylindrical cavity I form eccentric with it, a cylindrical guide for a ram
head projecting eccentrically from the piston, which ram head carries the moving
tool. The eccentricity of the guide relatively to the cylinder prevents the head
from turning round, and thus the tool is prevented from deviating angularly from
its true position. The guide, which I make of considerable depth particularly at
the back, supports the head and tool against such lateral strain as results from
shearing. Also as the head has its axis in front of the axis of the cylinder, the
tool carried by the head is near the front of the machine, so that the operator's
view of it is comparatively uninterrupted by any projecting parts of the machine.
The cylinder in which the hydraulic piston works is closed at the top by a tightly
fitting cover which may have formed in it a small cylinder fitted with a piston
attached to the main piston for the purpose of drawing the latter up after it has
made its down stroke. The draw back cylinder may be arranged in or on the
framing under the main piston, with a plunger pressing against that part of the
underside of the main piston which extends beyond the ecc-ntric guide. The stroke
of the piston is stopped by this part of it coming down on the bottom of the
cylindrical cavity.
Fig. 1 of the accompanying Drawings is a vertical section, and Figs. 2 and 2ª are
sectional plans of part of a hydraulic shearing or punching machine with its
cylinder and piston according to my invention. The cylinder in its lower part B

page_text: is bored eccentric to, and of smaller size than in its upper part A. The upper part
is fitted with the hydraulic piston C and the lower has sliding through it the
eccentric trunk D, which carries the shearing tool E or such other tool as may be
required. F is the cover of the cylinder in which may be formed the draw back
cylinder G. Instead of this, a weight or spring might be used for draw back, or a
push back plunger indicated by the dotted lines H may be applied to act below
the piston C. Obviously, the eccentricity of the trunk may be inverted as shewn
in Fig. 1º.
Having thus described the nature of my invention and in what manner the same
is to be performed, I claim, in respect of hydraulic machines for shearing, stamping,
punching and such like operations:
The construction of cylinder and eccentric guide elongated at the back to take
the thrust of the tool, substantially as and for the purposes herein set forth.
In Witness whereof I the said Ralph Hart Tweddell have hereunto set my
hand and seal this Twenty first day of March in the year of our Lord One
thousand eight hundred and eighty three.
RALPH HART TWEDDELL. (L.S.) ·