IMPROVEMENTS IN HYDRAULIC PRESSES
Year: 1878

page_text: LETTERS PATENT to James Watson, of Glasgow, in the County of Lanark,
North Britain, Engineer, for the Invention of "IMPROVEMENTS IN HYDRAULIC
PRESSES"
Sealed the 17th September 1878, and dated the 8th June 1878.
PROVISIONAL SPECIFICATION left by the said James Watson at the Office
of the Commissioners of Patents on the 8th June 1878.
JAMES WATSON, of Glasgow, in the County of Lanark, North Britain, Engineer.
"IMPROVEMENTS IN HYDRAULIC PRESSES."
The object of this Invention is to obtain an increase in the working speed of
hydraulic presses, and at the same time to reduce the number of pumps employed
without reducing the power of the presses.
The Invention has reference more particularly to the press described in the
Specification of my Letters Patent dated 28th October 1869, No. 3123.
The improvements mainly consist in a particular arrangement of and mode of
working a three-ram press, with the centre ram of smaller diameter than the two
outer rams; also in a particular construction of self-acting inlet valve to the large
cylinders, which valve takes off the pressure from the small cylinder when such
pressure attains a given limit; also in a particular arrangement (in addition to the
said self-acting valve) for taking the pressure off the small centre ram when it
reaches a given part of its stroke; also in a particular arrangement for opening the
main door and relief valve of the press.
The Invention will be understood by the following description of a press in which
the improvements are embodied :-The press has three rams, the centre of which is,
say, a three-inch ram, while the two outer are, say, 7 inch rams.
Each of these rams
is capable of making a stroke of, say, 16 feet 6 inches. The small ram has a
collar at its lower end, or at any other part that may be decided upon, and there is
a bush or inner projection at the top or other part of the small cylinder, against
which the said collar comes, as herein-after explained. There is also a collar or
...ת

page_text: projection on the lower end of the small cylinder, the purpose of which is likewise
herein-after explained. There is a valve in communication with an elevated tank
to allow water to flow into and from the large cylinders at the proper times. There
is a second valve which admits water from the pumps through a telescopic pipe to
the small cylinder, and also to a loaded self-acting valve. This self-acting valve is
loaded to the maximum pressure which is to be attained on the centre ram, so as to
open at such pressure and relieve the centre ram, and allow the water to flow
through such valve into the large cylinders; and in order to prevent this valve
closing, owing to the decrease in pressure which takes place when the water has
entered the large cylinders, the valve has a larger area at a part above its seat for
the purpose herein-after explained. There is a fourth valve for allowing the return
water from the centre cylinder to flow back into the pump cistern.
Such being the construction and arrangement of the parts of the press, I proceed
to describe its action:-Supposing the follower to be at the bottom of its stroke,
the press box filled, and all the valves shut, the valve first herein-before mentioned,
which is in communication with the elevated tank, is first opened to allow water to
flow from the tank by pipes over, but not through, the loaded valve into the two
large cylinders. Then the valve secondly herein-before referred to is opened, so as
to admit water from the pump by a pipe to the under side of the loaded valve, and
also through the telescopic pipe to the small centre cylinder. The small ram in
this cylinder will then rise, carrying with it the follower and the two large rams,
the two large cylinders during this movement being filled from the elevated tank.
When the follower has risen, say, 15 feet, the collar at the lower end of the small
ram comes against the bush or projection in the small cylinder, lifting this cylinder
off its seat, and consequently taking the pressure off the ram. At this point the
pressure in the centre cylinder will be, say, 15 cwt. to the square inch, which being
the maximum pressure calculated for this cylinder, will raise the loaded valve, and
allow the water to flow up through it into the two large cylinders. As soon as the
water has passed through the loaded valve the pressure, owing to the larger area of
the two large rams, will drop from 15 cwt. to, say, 2 cwt. to the square inch, and
therefore the load on this valve would close it again, but the water by acting on
the larger area, which, as before explained, this valve has at a point above
its seat, overcomes the load on the valve, and therefore keeps the valve open. This
increased pressure is borne not entirely by the spring, but by a cover bolted down
and regulating the lift of the valve. The valve which is in communication with
the elevated cistern is now closed, and the large rams will force up the follower
through the remaining portion of its stroke, say, 18 inches, carrying the centre
cylinder with it.
On the completion of the stroke the collar or projection before
mentioned on the lower end of this cylinder, by coming against a bush or other
suitable part, acts upon levers which open the lock of the main door and the relief
valve of the press. After the "grid," described in the Specification of the Letters
Patent beforo referred to, has been slid in, the inlet valve to the small cylinder is
closed, and the rams are lowered by opening the valve which communicates with
the elevated cistern, and also the outlet valve to the small cylinder.
Presses constructed as herein-before described are applicable where a long stroke
is required.
For short stroke presses I adopt an arrangement in which the ram is cored from
the bottom to near the top thereof, to receive a rod which has a passage through
the centre. Water is first admitted through the rod to the inside of the ram, so as to
act against the top of its bore. When the ram has risen a certain distance and more
power is required, water is admitted to the cylinder, so as to act upon the lower end
of the ram.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Watson in the Great Seal Patent Office on the 7th December
1878.
JAMES WATSON, of Glasgow, in the County of Lanark, North Britain, Engineer.
"IMPROVEMENTS IN HYDRAULIC PRESSES."
The object of this Invention is to obtain an increase in the working speed of
hydraulic presses, and at the same time to reduce the number of pumps employed
without reducing the power of the presses,
The Invention has reference more particularly to the press described in the Speci-
fication of my Letters Patent dated 28th October 1869, No. 3123.
The improvements mainly consist in a particular arrangement of and mode of
working a three-ram press, with the centre ram of much smaller diameter than the
two outer rams; also in a particular construction of self-acting inlet valve to the
large cylinders, which valve takes off the pressure from the small cylinder when
such pressure attains a given limit; also in a particular arrangement for taking the
pressure off the small centre ram when it reaches a given part of its stroke; also
in a particular arrangement for opening the main door and relief valve of the
press.
In the particular arrangement and mode of working a three-ram press, as above
mentioned, the small ram, which is of long stroke, does the first portion of the
work, this rain being effective only during such portion of the stroke as is safe for
such a small ram to work, and when the pressure in the small ram reaches the limit
to which it is calculated it can safely work, it is relieved by automatic means or by
hand.
The Invention will be understood by the following description of one modification
of press in which the improvements are embodied, Figure 1 of the annexed Drawings
being a side elevation, and Figure 2 a plan, partly in section, of the press :- -The
press has three rams A, A, B, the centre one B of which is, say, a 3 inch ram, while
the two outer A, A, are, say, 7 inch rams. Each of these rams is capable of
making a stroke of, say, 16 feet 6 inches. The small ram B has a collar C. at its
lower end, or at any other part that may be decided upon, and there is a bush or
inner projection D at the top (or it may be at any other suitable part) of the small
cylinder B', against which the said collar C comes, as herein-after explained. There
is also a collar or projection E on the lower end of the small cylinder B¹, the purpose
of which is likewise herein-after explained. There is a valve F in communication
with an elevated tank, to allow water to flow into and from the large cylinders A', A',
at the proper times through the pipes 1, 2, 3. There is a second valve G, which
admits water from the pumps through a pipe 5 and a telescopic pipe 6 to the small
cylinder B', and also by a pipe 4 to a loaded self-acting valve H. This self-acting
valve is loaded to the maximum pressure which is to be attained on the centre
ram B, so as to open at such pressure and relieve the centre ram, and allow the
water to flow through such valve H into the large cylinders A¹, A¹; and in order to
prevent this valve H closing, owing to the decrease in pressure which takes place
when the water has entered the large cylinders, the valve has a larger area at a
part H¹ above its seat, for the purpose herein-after explained. There is a fourth
valve I for allowing the return water from the centre cylinder B₁ to flow back into
the pump cistern.
Such being the construction and arrangement of the parts of the press, I proceed
to describe its action-Supposing the follower K to be at the bottom of its stroke,
as seen in the Figures, the press box filled, and all the valves shut, the valve F is
first opened to allow water to flow from the elevated tank by the pipes 1, 2, 3, over,
but not through the loaded valve H into the two large cylinders A¹, A¹. Then the
valve G is opened, so as to admit water from the pump by the pipe 4 to the
under side of the loaded valve H, and also through the pipe 5 and telescopic pipe 6

page_text: to the small centre cylinder B¹. The small ram B in this cylinder will then rise,
carrying with it the follower K and the two large rams A, A, the two large
cylinders A¹, A¹, during this movement being filled from the elevated tank. When
the follower has risen, say, 15 feet, the collar C at the lower end of the small rain B
comes against the bush or projection D in the small cylinder, lifting this cylinder
off its seat, and consequently taking the pressure off the ram B. At this point the
pressure in the centre cylinder will be, say, 15 cwt. to the square inch, which, being
the maximum pressure calculated for this cylinder, will raise the loaded valve H,
and allow the water to flow up through it into the two large cylinders A', A¹.
Should the pressure in the centre cylinder reach the given maximum before the
collar C comes against the bush D, the valve H will at once be raised, and the small
ram will be relieved. As soon as the water has passed through the loaded valve
the pressure, owing to the larger area of the two large rams, will drop from 15 cwt.
to, say, 2 cwt. to the square inch, and therefore the load on this valve would close
it again; but the water, by acting on the larger area H', which, as before explained,
this valve has at a point above its seat, overcomes the load on the valve, and there-
fore keeps the valve open. This increased pressure is borne, not entirely by the
spring H2 of the valve, but by a cover H3 bolted down and regulating the lift of
the valve. The valve F is now closed, and the large rams A, A, will force up the
follower K through the remaining portion of its stroke, say, 18 inches, carrying the
centre cylinder B¹ with it. On the completion of the stroke the collar or pro-
jection E on the lower end of this cylinder, by coming against a bush L or other
suitable part, acts upon levers M, M, which open the lock of the main door of the
press by means of the rod N, and also upon a lever M', which opens the press relief
valve O. After the "grid," described in the Specification of the Letters Patent before
referred to, has been slid in, the inlet valve G to the small cylinder is closed, and
the rams are lowered by opening the valves G and I. The valve G allows the
water in the large cylinders to pass up through it into the elevated tank by the
pipe 7, and the valve I allows the water in the centre cylinder to flow back into the
pump cistern by the pipe 8.
Figures 3 and 4 represent a modified arrangement of my improved press, in
which the loaded valve represented in Figures 1 and 2 is dispensed with, and a
simple self-acting valve H is employed, and in which the small cylinder B, instead
of being carried up with the large rams A, A, in the last portion of the stroke, is a
fixture, while the small ram B is not connected to the follower K, and is kept
central during the rising of the large rams by means of a sort of cross head P,
through which the large rams slide after the centre ram has stopped.
The working of the press shewn in Figures 3 and 4 is as follows:-Supposing the
follower is at the bottom of its stroke, and all the valves closed, first the valve G
is opened to allow water from the pumps to flow through the pipe 5 to the centre
cylinder B', so as to raise the ram B, which will carry the follower K and the two
large rams A, A, with it, the two large cylinders filling themselves from the elevated
tank through the valve H and pipes 2, 3. When the follower has been raised, say,
15 feet, the collar C at the lower end of the ram B comes against the bush D on
the cylinder B¹. At this part of the stroke either a bell is struck to give the signal
to the attendant to open the valve G', or this valve may be opened by suitable self-
acting means. Water from the pumps will then flow through the valve G¹ and
pipes 3, 4, to the large cylinders, the pressure closing the self-acting valve H. The
follower is thus raised the remaining portion of its stroke, while the centre ram B,
being loose, remains stationary, as indicated in Figure 5, in which the follower is
shewn at its highest position. The valves G and G¹ can now be closed, and the
grid be slid in.
In order to again lower the follower, the two outlet valves I and I'
are opened, when the return water from the two large cylinders will pass through the
pipes 2, 3, and 4, and valve I, to the elevated tank by the pipe 7, and the return
water from the small cylinder will pass through the pipes 5 and 6 and valve I¹ to
the pump cistern by the pipe 8.
Figures 6, 7, and 8 represent another modified arrangement of my improved

page_text: press, the construction of which will be fully understood from the following descrip-
tion of the mode of working it :-On starting to press, the inlet valve G is opened
to admit water from the pumps into the small cylinder B¹, so as to raise the small
ram B, which will carry the follower K and the two large rams A, A, with it, the
two large cylinders filling themselves from the elevated tank by the pipe 1. When
the pressure on the small ram rises to, say, 15 cwt., the ram will have risen, say,
13 feet, and as the self-acting valve H is loaded to 15 cwt. per square inch, it rises,
and allows the water from the pumps to pass into the large cylinders. The collar C
on the lower end of the small ram, on contact with the neck of the cylinder B¹,
entirely cuts off all pressure from the small ram, and also prevents this ram being
forced out of its cylinder. When the self-acting valve H rises it strikes a bell, and
the attendant shuts the valve I which communicates with the elevated tank, and
the pumps then produce the remainder of the stroke with the large rams, the small
ram being kept in position by the guide or cross head P, as in the press shewn in
Figures 3, 4, and 5. When the rams have to be lowered for the next pressing
operation, the water in the small cylinder B escapes through the self-acting valve H,
which is kept open by the attendant acting on the valve rod Q.
And having now described the nature of my said Invention, and in what manner
the same is to be performed, I declare that I claim as my "Improvements in Hy-
draulic Presses,"
First. Constructing long-stroke presses with a comparatively very small ram of
long stroke to do the first portion of the work, this ram being effective only during
such portion of the stroke as it can safely work, and being relieved, automatically
or otherwise, from all pressure beyond what it is able to sustain, substantially as
herein-before described.
Secondly. I claim the loaded self-acting valve to the large cylinders to take off
the pressure from the small cylinder when such pressure attains a given limit, the
said valve being constructed and working substantially as herein-before described,
and represented in Figures 1 and 2 of the annexed Drawings.
Thirdly. I claim the fitting of a collar on the lower end or other part of the
small ram for the purpose of taking the pressure off such ram when it reaches a
given part of the stroke, substantially as herein-before described, and represented in
the annexed Drawings.
Fourthly. I claim the arrangement for automatically opening the lock of the
main door and the relief valve (both or either of them) of the press, substantially as
herein-before described, and represented in the annexed Drawings.
In witness whereof, I, the said James Watson, have hereunto set my hand
and seal, this Fourth day of December, One thousand eight hundred and
seventy-eight.
J. WATSON. (L.S.)