IMPROVEMENTS IN HYDROSTATIC PRESSES
Year: 1863

page_text: LETTERS PATENT to Robert Luthy, of Solothurn, in the Republic of
Switzerland, and of No. 2, Thavies Inn, in the City of London, for the
Invention of 'IMPROVEMENTS IN HYDROSTATIC PRESSES."
Sealed the 3rd July 1863, and dated the 10th January 1863.
PROVISIONAL SPECIFICATION left by the said Robert Luthy at the
Office of the Commissioners of Patents, with his Petition, on the
10th January 1863.
1, ROBERT LUTHY, of Solothurn, in the Republic of Switzerland, and of No. 2,
Thavies Inn, in the City of London, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN HYDROSTATIC PRESSES," to be as follows:
The object of this Invention is to economise time and labour in the
working of hydrostatic presses, and also to reduce the weight of the same so
as to render them more portable, and thereby facilitating their conveyance to
distant parts.
My improvements are applicable to all hydraulic presses, but more
especially to those which are intended for packing cotton, wool, hay, and other
like materials, and in which the piston has to perform the greater part of its
stroke without meeting with much resistance. In ordinary presses hitherto
used for this purpose, the piston is forced through this part of the stroke simply
by forcing water into the cylinder in the usual manner by means of pumps or
by accumulators, and at a considerable outlay of time and power.
Now, my said improvements relate, firstly, to presses in which the piston
has to pass through the whole length of the stroke or lift, and consist in
raising or moving the piston through the first or principal part of the stroke

page_text: by means of a screw or screws, or by rack and pinion motion, or by other
suitable mechanism; but I prefer to use one or more smaller hydraulic rams
for effecting this object.
The said mechanism or apparatus may be connected with the press piston
through the press plate or cross piece, or may be made to act upon a rod
passing through the bottom of the cylinder, and bearing direct upon the
piston. In using a small hydraulic ram and cylinder, however, I propose to
place the same within the large cylinder, and partly within the ram or piston
of the latter; the pipe leading to the small cylinder is made to pass through
the bottom of the large cylinder. Supposing the large piston is to be raised,
the water or other fluid is forced into the small cylinder, whose piston bearing
upon the large pistor, will thereupon raise it till the above-mentioned part of
the stroke is completed, water or other fluid being at the same time allowed
to flow into the large cylinder through a pipe connected with the pump,
cistern, or other reservoir, and filling the same. The pipe leading to the
small cylinder is now shut off, and likewise the supply pipe to the large
cylinder, and the pressure pipe to the large cylinder is opened to give the final
pressure. The rams of the large and small cylinders are then disengaged in
the usual way; instead of having a pressure pipe for each cylinder, as described,
I also propose to use but one pressure pipe, and to make the small piston hollow
with apertures through its sides, which, when rising above the small cylinder,
will communicate pressure to the water or fluid in the large cylinder.
Secondly, my improvements relate to those hydraulic presses in which the
stroke of the piston of the large cylinder may be shorter than the lift required
for the whole operation. For this purpose I propose to effect the first part
of the stroke by means of a cylinder and piston of the requisite length, but of
small diameter, and therefore of comparatively small weight. The large
cylinder and its piston. which may rest on the small piston, are made of
only the length necessary for the final pressure, the weight of the same being
thereby reduced to a minimum. In this case the fluid is forced into the
small cylinder, and when its piston has completed the first part of the stroke,
the fluid passes into the large cylinder through a cock or valve forming part
of the piston of either cylinder, or of the small cylinder only.
Thirdly, my improvements relate to apparatus for supporting the platform
upon which the material to be compressed rests; for instance, when the small
piston has completed its stroke. These apparatus consist again in small
hydraulic cylinders into which the fluid is allowed to enter whilst their rams,
attached to the platform or cross piece, rise through the first part of the
stroke; when the rams are not in motion the suction valves will close and

page_text: prevent the escape of the fluid, which will now support the pressure or weight
resting upon them. I apply my said improvements to presses, whether working
upwards, downwards, or horizontally, as also to compound presses.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Robert Lutby in the Great Seal Patent Office on the
10th July 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, ROBERT
LUTHY, of Solothurn, in the Republic of Switzerland, and of No. 2, Thavies
Inn, in the City of London, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Tenth day of January, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-sixth year of
Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said Robert Luthy, Her special licence that I, the said
Robert Luthy, my executors, administrators, and assigns, or such others as
I, he said Robert Luthy, 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 HYDROSTATIC PRESSES," upon the condition (amongst others)
that I, the said Robert Luthy, my executors or administrators, by an instru-
ment 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 imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Robert Luthy, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement:
The object of my Invention is to economise time and labour in the working
of hydraulic presses, and also to reduce the weight of the same so as to
render them more portable, and thereby facilitating their conveyance to
distant parts.
My said improvements are applicable to all hydraulic presses, but more

page_text: especially to such as are intended for packing cotton, wool, hay, and other
like materials, and in which the piston has to perform the greater part of the
stroke without meeting with much resistance. In the ordinary presses
hitherto used for this purpose the piston or ram is forced through this first
part of its stroke simply by forcing the water or other fluid into the cylinder
in the usual manner, namely, by means of pumps or accumulators, and at a
considerable outlay of time and labour.
Now, my said improvements relate, firstly, to presses in which the piston
or ram has to pass through the whole length of the stroke or lift, and consist
in raising or moving the ram through the first or principal part of the stroke
by means of a screw or screws, or by rack and pinion motion, or by other
suitable mechanism; but I prefer to use one or more smaller hydraulic rams
for effecting this object.
The said mechanism or apparatus may be connected with the press piston
or larger ram through the press plate commonly called follower, or it may be
made to act upon a rod passing through the bottom of the cylinder, and
bearing direct upon the ram. In using a small hydraulic ram and cylinder,
however, I propose to place the same either outside the large cylinder, the
small ram passing through the bottom of the latter, or inside the same, and
partly inside the larger ram, so that the small ram acts directly upon the large
one, and moves the same through the first part of the stroke, the pressure
from the pump or accumulator being at the same time communicated to the
fluid in the small cylinder only. During this part of the stroke the large
cylinder is filled with water or other fluid supplied from the pump cystern or
other reservoir. When the resistance of the material under pressure is equal
to the pressure of the small ram the supply from the reservoir to the large
cylinder is shut off, and the pressure from the pump or accumulator is com
municated to the large ram, which will then complete the stroke, and give
the final pressure.
The small ram may be stationary during this last part of
the stroke, and consequently so much shorter, or it may move with the large
ram through the whole stroke. The admission of the supply to the large
cylinder, and the communication of pressure to the ram may be effected by
working cocks or valves by hand; but I propose to use a self-acting apparatus
connected with all the pipes leading to the cylinders, pumps, or accumulator
and supply reservoir. This apparatus consists of suction valve for the supply
of the large cylinder during the first part of the stroke of a valve weighted
according to the pressure of the pumps or accumulator, which will open and
communicate pressure to the large cylinder, when the small ram meets with
a resistance equal to its pressure, and of an arrangement for disengaging the

page_text: cylinders either by common stop-cocks, or by opening the suction valve to
disengage the large cylinder.
To communicate the pressure to the large cylinder I also propose to make
the small ram hollow and fitted with a valve bearing against the large ram,
which valve will open when the resistance is equal to the pressure on the
valve. This arrangement may also be used as a self-acting apparatus in con-
nection with the pipes leading to the cylinders instead of being part of the
The sinal rain may also be hollow, with apertures through its sides
to communicate the pressure to the larger ram at the end of the first part of
the stroke.
rams.
Secondly, my improvements relate to those hydraulic presses in which the
stroke of the larger ram may be shorter than the lift required for the whole
operation. For this purpose I propose to effect the first part of the stroke
by means of a cylinder and ram of the requisite length, but small diameter,
and therefore of comparatively small weight. The large cylinder and its ram,
which may rest on the small ram, are made of the length necessary for giving
the final pressure, the weight of the same being thereby reduced to a
minimum. In this case the fluid is forced into the small cylinder, and when
its ram has completed the first part of the stroke, the fluid passes into the
large cylinder through a cock or valve forming part of either cylinder or ram,
or it may pass through extra pipes to the large cylinder.
Thirdly, my improvements relate to apparatus for supporting the platform
or follower, or the cylinder and rams upon which the material to be com-
pressed rests-for instance, when the small ram has completed its stroke.
These apparatus consist, again, in small hydraulic cylinders, into which the
fluid is allowed to enter, whilst their rams attached to the follower rise
through the first part of the stroke. When the rams are not in motion the
suction valves will close and prevent the escape of the fluid, which will now
support the pressure or weight resting upon them. I apply my said improve-
ments to presses, whether working upwards, downwards, or horizontally, as
also to compound presses.
But in order that my Invention may be fully understood and readily carried
into effect, I will now proceed to describe the same, reference being had to the
two accompanying Sheets of Drawings, and to the figures and letters marked
thereon.
On Sheet I., Figs. I., II., and UIII. represent parts of the hydraulic presses
in section, constructed according to my improvements. Fig. I. shews an
arrangement with the small cylinder placed within the larger one; Figs. 11.
and III. represent the small cylinder placed outside the larger one.

page_text: In Figs. I., 11., and III., A represents the large cylinder; B, the large
ram; a, the small cylinder; b, the small ram; C, the supply pipe for the larger
cylinder; c, the pipe for the smaller cylinder. Fig. IV. represents, in section,
and on
larger scale, a self-acting apparatus through which the fluid
from the pumps or accumulator and the reservoir has to pass to reach the
cylinders.
In working presses constructed as shown in Figs. 1. and II., and provided
with a self-acting apparatus, as shown in Fig. IV., the water, oil, or other
fluid is forced by the pumps or accumulator into the self-acting apparatus al o,
see Fig. IV., and from there direct through the pipe into the smaller
cylinder a, the ram b of which being against the larger ram B, will move the
same till the resistance of the material to be compressed is equal to the force
of the small ram b. During this part of the stroke the space vacated by the
larger ram B is filled up with fluid which enters the cylinder A from a supply
reservoir through the pipe f, the suction valve d, and the pipe c, see
Fig. IV.
When the rams have arrived at the end of the first part of the stroke, the
fluid under pressure will open the valve g, which is weighted accordingly by
a spring or weights; the fluid is thus forced through the pipe C into the large
cylinder A, the ram B of which will then complete its stroke, and give the
final pressure. The fluid is after each operation led back from the cylinders to
the pump and supply cistern by opening common stop-cocks, not shown in
the Drawings or in order to empty the large cylinder more speedily, the
valve may be opened by a screw p, as shown in Fig. IV., or by any other
suitable arrangement.
A press arranged as shewn in Fig. III. works in the following manner:
The fluid enters the small cylinder a through the pipe c; the ram b is hollow,
and is fitted at the top with a valve h bearing against the large ram B; the
valve his pressed slightly against its seating fixed to the top of the small
ram by a spring i. in order to hold it in its position. The area of this
valve is a little smaller than the area of the ram b, which will cause the
scating to separate from the valve h as soon as the resistance of the large
rain B or the valve is equal to the pressure of the fluid on the other side of
the valve. The large cylinder A, which was supplied during this part of the
stroke with the fluid from the reservoir D, through the suction valve d, is
now open to the action of the pumps, or the accumulator, and the ram B will
give the final pressure.
On Sheet II. of Drawings is represented a front elevation of part of a
press suitable for baling cotton. In this case the stroke of the small ram is

page_text: of only the length necessary to give the first part of the stroke, and its area is
only such as is necessary to overcome the resistance of the material to be
compressed at the end of this part of the stroke. The large cylinder with its
ram is moved by the small ram through the first or principal part of the
stroke requisite for the operation of baling, and the dimensions of this large
cylinder and ram are not larger than necessary for giving the last part
of the stroke and the final pressure. According to this arrangement,
presses can be constructed of a number of separate pieces of comparatively
Small weight, which facilitates their conveyance to distant parts; the
principal advantage, however, consists in the great saving of time and labor
in working such presses. In working such presses the fluid is first forced
into the small cylinder a, whereby the ram b with the large cylinder A. and
its ram B and follower D are raised. When the ram b has arrived at the
end of its stroke, the large cylinder A is propped up in this position by two
beams p, p, brought by a suitable arrangement under the two corresponding
projections A', A', of the cylinder A, and resting in the columns C, C, which
may form part of the box O, O, and which are made strong enough to resist
the pressure. The fluid is then admitted to the large cylinder A either
through a pipe connected with it, or through the smaller ram b, and which
is provided with suitable cocks or valves, not shown in the Drawing, and the
ram B thereupon will give the final stroke and pressure. It is obvious that
more than one hydraulic cylinder may be employed for the first part of the
stroke as well as for the final compression, and, if preferred, the top cylinders
may be inverted, and form part of the follower, and the proping may be
effected by hydraulic cylinders, as herein-before described. In place of lifting
the hydraulic cylinders and ram by means of a cylinder and ram of smaller
diameter, I also propose to lift the said cylinder and ram by means of screws
or other suitable mechanical arrangement.
Having now described the nature of my said Invention, and the manner
in which the same may be carried into effect, I wish it to be understood that I
do not confine or limit myself to the precise details and arrangements as shewn
and described, as the same may be modified according to the purposes for
which they are to be applied; but what I do claim as the Invention to be
secured to me by the herein-before in part recited Letters Patent, is,―
Firstly, the moving of the ram or rams of hydraulic presses, or of the
hydraulic cylinders and rams through the first and greater part of the stroko
by means of screws. rack and pinion in other suitable mechanism, as herein-
before described.
Secondly, the mode of raising or moving the rams of hydraulic presses. or

page_text: the cylinders and rams through the first and greater part of the stroke by
means of smaller rams of an area and length proportionate to the lift and
pressure required, as described and shewn in Figures I., II., and III. of
Sheet I., and on Sheet II. of Drawings.
Thirdly, the mode of proping or supporting the follower or the cylinders
and rams for giving the final pressure by means of hydraulic cylinders and
rams of smaller diameters, as herein-before described.
Fourthly, the construction and application of the valve arrangement h, i, k,
Fig. ILL, on Sheet I., in the manner and for the purpose substantially as
described.
And, lastly, the arrangement of valves and parts connected therewith, as
shown in Fig. IV. on Sheet I., and its application, in the manner and for the
purpose substantially as described.
In witness whereof, I, the said Robert Luthy, have hereunto set iny
hand and seal, this Tenth day of July, in the year of our Lord One
thousand eight hundred and sixty-three.
ROBERT LUTNI. (L.S.)