HYDRAULIC PRESS FOR FORGING AND OTHER PURPOSES
Year: 1885

page_text: COMPLETE SPECIFICATION.
We, RALPH HART TWEDDELL of N° 14 Delahay Street Westminster in the
County of Middlesex, Engineer, JAMES PLATT and JOHN FIELDING both of Atlas
Works Gloucester in the County of Gloucester, Engineers do hereby declare the
nature of our invention for "HYDRAULIC PRESS FOR FORGING AND OTHER
PURPOSES and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement :-
"
Our invention relates to a construction and arrangement of hydraulic press
applicable for forging and other purposes, our object being to provide for con-
veniently varying the pressing power, for economising the pressing fluid, and for
arranging the hydraulic cylinders so as not to interfere with the operation of the
press. We will describe a press according to our invention adapted for forging,
referring to the accompanying drawings. Fig. 1 is a front view and Fig. 2
a vertical transverse section, Fig. 3 is a side view, Fig. 4 a sectional plan of the
base, Figs. 5 and 6 plans of the upper and lower crossheads respectively. A is
a stationary frame or base on which is placed the anvil or bottom tool B. Within
the base A we arrange several (three being shewn in the drawings) hydraulic
cylinders C with their rams C₁ projecting through packing downwards and butting
against a lower crosshead D. This crosshead is connected to an upper crosshead E
by suitable ties F which are guided through the base A. The upper tool or die E¹
is attached to the crosshead E. Below the crosshead D is situated another
hydraulic cylinder G the ram G' of which butts against the crosshead D. Each of
the cylinders C is connected by pipes provided with suitable valves as indicated
at V to a high pressure supply and to a discharge and also to a low pressure tank
by a passage provided with a check valve. The cylinder G is also connected to
a high pressure supply and to a discharge. The operation is as follows. The
head E being raised by the action of pressure in the cylinder G, and the work to
be forged W being laid on the anvil B, the pressure in G is relieved and thereupon
the heads D and E descend by gravity, the cylinders C becoming filled with low
pressure water as their rams C¹ descend. The high pressure service is now turned
on to one, two or more of the cylinders C as the case may be, and the head D is
urged down, bringing the upper tool E¹ forcibly down on the work W. On
relieving the pressure in the cylinders C and again admitting pressure to act
in G, the crossheads D and E are raised ready for a succeeding operation. The

page_text: cylinder G may be kept constantly in communication with the high pressure
supply, provided the area of its ram be sufficiently small to allow of the pressure
The check
on it being overcome by the weight and pressure acting against it.
valve in the passage from each of the cylinders C to the low pressure tank may be
opened for discharge of the water from the cylinder back to the tank. By this
arrangement all the massive parts of the apparatus being below the base, there is
free access to the work above, and when the press is used for forging, the packings
are so far distant from the work that they are not injuriously affected by the heat.
By the use of one, two or more of the several cylinders C, the power of the press
can be varied as required, and, as a considerable part of the descending movement
may be effected without great pressure, the cylinders C during that part may
merely draw in low pressure water without involving waste of the high pressure
water, which can be turned on at any desired part of the stroke.
Obviously, instead of fixing the cylinders C in an inverted position to the
base A with their rams butting against D, the cylinders C may be fixed to or butt
against D and move with it whilst their rams C₁ are attached to the base A.
In this case, in order to avoid the use of flexible or jointed pipes, the rams C¹ may
be tubular, the communication for liquid to the cylinders C being made through
them.
By making the lower ends of the rams C¹ in segmental form as shewn in Fig. 6
and providing similar holes in .the crosshead D, the rams, on being turned one
quarter round, can be lowered into the body of the crosshead a sufficient distance
for giving access to the packing of their cylinders.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is.
The construction and arrangement of hydraulic press substantially as herein
described and illustrated by the Drawings.