provements in Hydraulic Accumulators.
Year: 1888

page_text: PROVISIONAL SPECIFICATION
Improvements in Hydraulic Accumulators.
We, CARL PROTT and ROBERT SEELHOFF of Witten in the Kingdom of Prussia
and Empire of Germany, Engineers do hereby declare the nature of our invention
to be as follows
Instead of the usual employment of weights, or, in some cases of steam pressure
for the loading of hydraulic accumulators, the herewith described invention applies
This piston
compressed air or other gases, which act on a piston in a cylinder.
is attached to a plunger in another and preferably smaller cylinder and according
to the relation of the diameters of the cylinders, the tension of the fluid in the
second cylinder may be multiplied The compressed fluid is taken from the second
cylinder for the purposes that may be required
The applied gases can be developed out of solid or liquid masses (for example
liquid carbonic acid), placed in the cylinder or in vessels attached to it, or they
can be brought to the cylinder in a compressed condition (for example compressed
air).
If the capacity of the cylinder is not large enough to avoid a too varying
pressure in case of the employment of permanent gases, the cylinder is attached
to one or more vessels giving an enlarged capacity.
For the sake of attaining a perfect piston-packing in the gas cylinder, the piston may
be covered with a fluid (for example glycerine). The arrangement can be modified
in so far as the cylinder can be placed in a horizontal or inclined position instead of
vertical.
For the sake of attaining a perfect tightness of the gas-cylinder or vessels against
the high pressure of the gases, the sides can be arranged double and the intermediate
spaces filled with fluid being under the same pressure as the interior of the cylinder
or vessel.

page_text: COMPLETE SPECIFICATION.
Improvements in Hydraulic Accumulators.
We, CARL PROTT and ROBERT SEELHOFF of Witten in the Kingdom of Prussia,
and Empire of Germany, Engineers, do hereby declare the nature of this invention
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement :-
Instead of the usual employment of weights, or, in some cases of steam pressure for
the loading of hydraulic accumulators, the herewith described invention applies
compressed air or other gases, which act on a piston in a cylinder. This piston is
attached to a plunger in another and preferably smaller cylinder and according to the
relation of the diameters of the cylinders, the tension of the fluid in the second cylinder
may be multiplied The compressed fluid is taken from the second cylinder for the
purposes that may be required.
The applied gases can be developed out of solid or liquid masses (for example liquid
carbonic acid), placed in the cylinder or in vessels attached to it, or they can be brought
to the cylinder in a compressed condition (for example compressed air).
If the capacity of the cylinder is not large enough, to avoid a too varying pressure
in case of the employment of permanent gases, the cylinder is attached to one or
more vessels giving an enlarged capacity
For the sake of attaining a perfect piston-packing in the gas-cylinder, the piston
may be covered with a fluid (for example glycerine) The arrangement can be
modified in so far as the cylinder can be placed in a horizontal or inclined position
instead of vertical
For the sake of attaining a perfect tightness of the gas-cylinder or vessels against
the high pressure of the gases, the sides can be arranged double and the intermediate
spaces filled with fluid being under the same pressure as the interior of the cylinder
or vessel.
In the accompanying drawings we have represented sections of six different forms
of apparatus or parts of apparatus constructed according to our invention.
With reference to Fig. 1, is the piston upon which acts compressed air or other gas
within the cylinder a. c is the plunger to which the piston is attached and which is
preferably of a diameter smaller than the piston b d is the cylinder in which the
plunger c works and p is the pipe which conducts water or other liquid or mixture of
liquids which may be used for operating the hydraulic apparatus, from the pressure
pump to the cylinder d. q is the pipe by which the said liquid is conducted from the
cylinder d to the lifts, presses or other apparatus which it is intended to operate. The
cylinder d is preferably cast in one piece with the cross head d¹ to which the cylinder a
is tied by the standards d and ring a' or by any other suitable means
e is the fluid, advantageously glycerine, which we use to prevent the escape of air
or gas from the cylinder a around the piston b.-

page_text: In figure II the cylinder a is connected by means of the pipe and valve to with the
vessel which thereby increases the capacity of the apparatus. a' is a hole and cover
which admits of access being bad to the interior of the cylinder a when required.
In figure III an air pump k is shown connected to the cylinder a as the means
employed for compressing air in the cylinder a and generally the other parts of
the apparatus correspond with those shown in figures 1 and 11 except in so far as
the shape of the piston b which however is unimportant to the working of the
invention.
Fig. IV shows how the properties of liquid as applied to the securing of a
tight joint around the piston may be applied to a cylinder the inverse of those
shown in figures 1 2 and 3. In this construction the cylinder a is connected by
a tube as with the compressed air or gas chamber a*.
In the apparatus shown in figure V the piston rod is connected to mechanism
for indicating the position of the piston in the accumulator and the consequent
amount of fluid under pressure available for use, connections also being if desired,
made for effecting the stoppage of the pump when the said accumulator is fully
charged. This form of accumulator is well adapted to wagon lifts as the pressure
in it increases as the piston ascends and vice versá
In figure VI we have illustrated the manner in which we ensure the tightness
of the gas cylinders or vessels so as to prevent the escape of the air or gas
therefrom. For this purpose we surround each of the said vessels with a jacket
so as to leave a space between it and the wall of the vessel
Into this space is
forced fluid at the same pressure as the air or gas contained within the inner
vessel. To enable pipes to be connected to the inner vessel say at the top as
illustrated in figure VI the said inner vessel at that part is preferably formed with
a neck so as to present the least possible surface to the air or gas. Among other
advantages gained in our construction of accumulators over those in which weights
are employed may be mentioned
;-
(a) The facility with which they may be transported from place to place owing
to their comparatively small weight and compactness.
(b) They are less costly to manufacture
(c) They can be worked at a higher rate of speed as the effects of shocks and
consequent wear and tear of the parts hitherto generally attendant on the working
of the heavy weights at a high speed will be avoided
(d) By their compactness they are well adapted for being mounted on the same
carriages as the apparatus they are to operate for example rivetting apparatus
We have found that suitable means for compressing the air for use in the
before described apparatus consist of small air compressors such as are used in
torpedo boats and a suitable degree of compression we have found from 50 to 60
atmospheres. For smaller pressures such for example as from 20 to 50
atmospheres we prefer to employ carbonic acid gas, a convenient way of applying
which is the form of carbonic acid when it is contained in iron bottles or flasks
that is to say the manner in which it is frequently sold, these flasks being
preferably screwed to the before described air or gas vessel with a valve so
situated that communication between the said vessel and flask may at any time be
cut off.
The before described air or gas vessels are preferably constructed of welded mild
steel but they may if desired be constructed of other metal.
In cases such as for forging purposes where it is desirable to have varying
pressures we use two or more accumulators of different pressures one perhaps with
the relation of 1 to 10, giving say 500 atmospheres water pressure and another
with the relation of 1° to 1° giving 50 atmospheres or 1 to 2 giving 100 atmospheres
pressure.
Where the accumulators are constructed with the relation of 1 to 1 as indicated
in figure V they may be regarded merely as air-vessels with the piston situated
between air and fluid both under the same pressure.

page_text: In apparatus where the press platen or plunger partakes of only a small travel
as in presses for stamping plates or pressing keys or the like, the variability of
the accumulator pressure as is a peculiar feature of the before described accumulator,
is advantageous in so far as the pressure corresponds to the position of the
piston and therefor different pressures may be obtained by regulating the position of
the said piston, the vessel a then acting as a regulator.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what
we claim 18,-
1. A hydraulic accumulator in which the pressure is obtained solely from the
tension of the fluids contained in the cylinder or in one or more closed vessels
connected to and forming substantially part of it or from its own piston substantially
as described and illustrated in the accompanying drawings.
2. A hydraulic accumulator in which a piston or the like working within a
cylinder is acted upon by compressed air or gas the piston being attached to a
hydraulic plunger and the gas being developed out of liquid or solid materials
placed in the cylinder or in one or more closed vessels connected to and forming
substantially part of it or brought to the cylinder in a compressed condition
substantially as herein described.
3. In apparatus such as described the employment of fluid for preventing the
escape of air or gas upon around or under the piston substantially as herein described
and illustrated in the accompanying drawings
4. In apparatus such as described the employment of a casing or jacket in which
water or other liquid is maintained at the same pressure of the air or gas contained in
the cylinder or vessel which it surrounds substantially as and for the purpose herein
described.
Dated this 4th day of March 1889