IMPROVEMENTS IN THE MODE OF AND MEANS FOR WORKING HYDRAULIC APPARATUS
Year: 1878

page_text: LETTERS PATENT to James. Henry Greathead, of Victoria Chambers, and
Montagu Durance Martindale, of Great George Street, both in the City of
Westminster, for the Invention of "IMPROVEMENTS IN THE MODE OF AND
MEANS FOR WORKING HYDRAULIC APPARATUS."
Sealed the 7th March 1879, and dated the 10th September 1878.
PROVISIONAL SPECIFICATION left by the said James Henry Greathead and
Montagu Durance Martindale at the Office of the Commissioners of Patents
on the 10th September 1878.
.
JAMES HENRY GREATHEAD, of Victoria Chambers, and MONTAGU DURANCE
MARTINDALE, of Great George Street, both in the City of Westminster. "IM-
PROVEMENTS IN THE MODE OF AND MEANS FOR WORKING HYDRAULIC APPARATUS."
In hydraulic presses, lifts, engines, and the like, in which a piston or plunger is
urged by the pressure of water or other liquid, it is usual to supply the cylinder
with the liquid under pressure to the same extent whether the load or resistance to
be overcome is great or small, hence when there is a light load to be moved there is
a great waste of the motive force.
This Invention relates to the means of avoiding such waste by proportioning the
amount of high-pressure liquid used to the resistance to be overcome. For this purpose
we employ in the supply pipe of the cylinder a regulating nozzle constructed as an
injector, and communicating with the high-pressure supply, and also with a low-
pressure cistern or pipe.
The high-pressure supply is regulated as in an injector by a conical valve, and the
low-pressure inlet may also be regulated in like manner.
By partially opening the high-pressure supply a portion of the low-pressure liquid
is caused to flow along with the high-pressure liquid into the working cylinder, and
the working pressure therein is proportionately reduced, and so by the more or less
opening of the high-pressure supply the working pressure is regulated as desired

page_text: with reduced expenditure of the high-pressure liquid in all cases where the working
pressure requires to be less than the full pressure of the supply.
The high-pressure supply may be regulated automatically by connecting the
regulating nozzle to a piston subject to the pressure in the working cylinder, so that
as that pressure becomes greater or less, according as the resistance increases or
diminishes, the nozzle is more or less. opened.
The injecting nozzle or cone may in some cases be adjusted to a fixed position,
the quantity of low-pressure liquid admitted to the working cylinder being deter-
mined by the velocity of its piston or ram permitting a greater or less velocity of
high pressure in flow.
Instead of or in addition to the lateral action of the high-pressure liquid as
means for introducing low-pressure liquid with it into the working cylinder, a screw,
turbine, or other rotary apparatus may be applied to receive movement from the
high-pressure flow, and to urge the low-pressure liquid to flow along with it.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said James Henry Greathead and Montagu Durance Martindale in
the Great Seal Patent Office on the 10th March 1879.
JAMES HENRY GREATHEAD, of Victoria Chambers, and MONTAGU DURANCE
MARTINDALE, of Great George Street, both in the City of Westminster. "IM-
PROVEMENTS IN THE MODE OF AND MEANS FOR WORKING HYDRAULIC APPARATUS."
In hydraulic presses, lifts, .engines, and the like, in which a piston or plunger is
urged by the pressure of water or other liquid, it is usual to supply the cylinder
with the liquid under pressure to the same extent whether the load or resistance to
be overcome
great or small, hence when there is a light load to be moved there is
a great waste of the motive force.
This Invention relates to means for avoiding such waste by approximately pro-
portioning the amount of high-pressure liquid used to the resistance to be overcome.
For this purpose we employ in the supply pipe of the hydraulic cylinder a regu-
lating nozzle constructed as an injector, and communicating with the high-pressure
supply, and also with a low-pressure cistern or pipe.
The high-pressure supply may be regulated, as in an injector, by a conical valve,
and the low-pressure inlet may also be regulated in like manner.
By partially opening the high-pressure supply a portion of the low-pressure
liquid is caused to flow along with the high-pressure liquid into the working
cylinder, thus reducing the expenditure of the high-pressure liquid in cases
where the working pressure needed is less than the full pressure of the supply.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 represents in sectional elevation apparatus constructed according to our
Invention for supplying the working cylinder of a hydraulic press, crane, lift, or
engine partially with low-pressure liquid.

page_text: A is the high-pressure supply pipe; B, the low-pressure supply, which is provided
with a check valve of any known construction; Ċ is the discharge pipe; and D is
the pipe communicating with the working cylinder. In this pipe is fitted an
injector arrangement consisting of a nozzle a supplied from the pipe A with a
quantity of the high-pressure liquid, regulated by the cone plunger E, with suitable
concentric guide tubes F and G for controlling the supply of low-pressure liquid which
flows in the direction of the arrows to the hydraulic cylinder, combining in its
passage with the high-pressure liquid supplied by the pipe A. H is the plunger
valve for opening the discharge passage for the escape of the liquid from the
hydraulic cylinder.
In operating with this apparatus the coned plunger Ẹ is retracted more or less,
according to the greater or less pressure or speed required in the working cylinder.
The high-pressure liquid issuing by the nozzle a causes by its lateral action a
quantity of low-pressure liquid supplied from B to enter the cylinder along with it,
and the check valve before mentioned in the pipe B prevents any back flow from
the cylinder or pipe leading thereto. For the back stroke of the hydraulic piston
the plunger valve E is closed and the discharge valve H is opened.
The discharge pipe C and valve H may obviously be arranged between the
injector and the cylinder, thus avoiding retardation of the back stroke of the
passage of the discharge liquid through the injector.
Fig. 2 represents a section of a modified arrangement of the injector, according
to which a portion of the low-pressure liquid is supplied through the plunger E,
which is made tubular for that purpose, the tubular plunger being brought into
connection by an elastic pipe E' with the low-pressure supply pipe B.
In this Figure all the parts corresponding to those in Fig. 1 are marked with
similar letters.
Figures 3 and 4 represent diagrammatically an arrangement whereby a portion
of the discharge for one back stroke may be utilized for a succeeding forward stroke
by the application of an injector arrangement of the kind described above.
Fig. 3 is a section through the set of valves which govern the flow of the liquid,
and Fig. 4 is a plan of these valves and the communications therewith.
In these Figures A is the supply pipe for the high-pressure liquid, C is the dis-
charge from the cylinder, and D is the pipe communicating with the cylinder; I is
a cistern or source of supply of low-pressure liquid, and K is an air vessel; L, L, are
check valves seating, as shewn in Fig. 4, and M, N, are valves worked by hand as
E and H; in the former Figures O, P, are injector nozzles similar to a. In operating
with this arrangement, applied, for instance, to a hydraulic crane or hoist, when a
very light load has to be lifted, as, for example, in taking up the hoisting chain
alone, the force developed by the descent of the previous load is utilized in the
following manner :-In order to lower the load the valve M is first opened, allowing
the discharge liquid to flow from the working cylinder into the air vessel K, taking
with it by its lateral action at the nozzle 0 a portion of low-pressure liquid from
the supply I. As the pressure in K increases the quantity of low-pressure fluid
drawn in at O will diminish, and finally the inductive action will cease.
the further increase of pressure in K the descent of the load is inconveniently
retarded, the valve H is opened, allowing the rest of the liquid to be discharged
from the working cylinder into I. There is thus stored up in the vessel K a pressure
available for a subsequent operation. Should this be the lifting of a light load or
taking-up chain, the valves H and M being closed, the valve N is first opened,
whereupon liquid flows from the air vessel K to the working cylinder, taking with
it by its lateral action at the nozzle P a portion of low-pressure liquid from I, the
inductive action diminishing and finally ceasing as the pressure in K decreases.
When by
When the ascent of the chain or light load is inconveniently retarded owing to
the reduction of the pressure in K, or when there is not sufficient pressure in K to
raise the load, or when the slack of chain being taken up, a heavy load comes upon
it, the valve E is opened, allowing high-pressure liquid to flow into the working
clyinder. This flow, by its lateral action at the nozzle a, takes with it a portion of

page_text: the liquid at lower pressure, first, from the air vessel K, and then from the supply I
flowing past the nozzle P.
The valves L, L, as will be seen in Fig. 4, are so arranged as to allow the flow in
. the directions above-set forth, but to prevent flow in the opposite directions.
The valves H, M, E, and N may be either worked separately or connected to a..
lever by links so arranged that they are opened or closed in due order according as
the lever is put in different attitudes, or in certain cases they may be worked in
combination as slide valves.
..Although for the sake of clearness we have shewn in the accompanying Drawings
injector nozzles of a simple character, they might obviously be sub-divided and
. fitted with several sets of guide tubes, so as to utilize to a greater extent the lateral
inductive action of the high-pressure stream or streams.
An example of such an arrangement is shewn in section at Fig. 5, here the
.high-pressure supply governed by a slide R is divided into two annular streams S
and T, whilst the low-pressure supply from the pipe U is sub-divided into a central-]
stream V and two annular streams W and X, the whole passing to the working
cylinder by the pipe Y.
The sub-divided streams instead of being annular may be separate jets, arranged
annularly or otherwise.
Having thus described the nature of our Invention, and in what manner the same
is to be performed, we hereby declare that we make no general claim to the use of
injector nozzles for the purpose of creating currents in liquids, but we claim,
First. The method, substantially as herein described, of supplying a hydraulic
cylinder with operating liquid, consisting partly of high-pressure liquid and partly
of liquid drawn from a low-pressure supply by the inductive lateral action of the
high-pressure liquid.
Second. In connection with the induction passage of a hydraulic cylinder the
*combination of a high-pressuro injector nozzle with a low-pressure supply pipo
provided with a check valve, substantially as and for the purposes herein set
forth.
In witness whereof, we, the said James Henry Greathead and Montagu Durance
Martindale, have hereunto set our hands and seals,. the Tenth day of
March, in the year of our Lord One thousand eight hundred and seventy-
nine
J. H. GREATHEAD.
(L.S.)
MONTAGU MARTINDALE: (L.S.)