IMPROVEMENTS IN HYDRAULIC LIFTS
Year: 1880

page_text: LETTERS PATENT to Edward Bayzand Ellington, of the Chester Hydraulic
Engineering Works, Chester, in the County of Chester, for an Invention of
" IMPROVEMENTS IN HYDRAULIC LIFTS."
PROVISIONAL SPECIFICATION left by the said Edward Bayzand Ellington
at the Office of the Commissioners of Patents on the 20th October 1880.
EDWARD BAYZAND ELLINGTON, of the Chester Hydraulic Engineering Works,
Chester, in the County of Chester. "IMPROVEMENTS IN HYDRAULIC LIFTS."
My Invention relates to a construction and arrangement of hydraulic lift,
whereby I am enabled to dispense with the counter balance weights, chains, and
pullies usually employed for such lifts, and thus to simplify their structure and
action. For this purpose I connect the cylinder of the lift by a pipe with a
secondary cylinder fitted with a trunk piston, and I extend the trunk of this piston
and connect it to the piston or plunger of a third cylinder. The annular space of
the secondary cylinder is always in communication with the accumulator or reservoir
that supplies the working fluid, and the pressure of this fluid on the annular area
serves as the constant counterbalance to the ram and cage of the lift. The third
cylinder communicates with the accumulator or reservoir, and also with the
discharge pipe by suitable cocks or valves, so that the piston or plunger of this
third cylinder can either be subjected to the pressure of the working fluid or
relieved therefrom. In the former case the pressure acting on the piston or
plunger of the third cylinder, as well as on the annular area of the piston in the
second.cylinder, causes that piston to advance, forcing liquid into the lift cylinder,
and so causing the ascent of the lift. In the latter case when the piston of the
third cylinder is relieved from pressure, the lift descends, forcing liquid into the
second cylinder, and so causing its piston to retreat in opposition to the pressure on
its annular area, the fluid which was contained in the annular space being thus
returned to the accumulator or reservoir. By suitably proportioning the areas on
which the fluid acts, the relative pressures in the lift cylinder and in the accumulator
or reservoir may be proportioned as desired. In order to provide for loss by
leakage from the lift cylinder, I connect it or the second cylinder which communi-
cates with it to the accumulator or reservoir by a pipe provided with a cock or
valve which can be opened when required to admit fluid to the lift cylinder. In cases
where the other parts of the apparatus may require repair, the lift may, by means
of this pipe, be worked direct from the accumulator or reservoir, suitable cocks or
valves being provided.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Edward Bayzand Ellington in the Great Seal Patent Office on the
20th April 1881.
EDWARD BAYZAND ELLINGTON, of the Chester Hydraulic Engineering Works,
Chester, in the County of Chester. "IMPROVEMENTS IN HYDRAULIC LIFTS."
My Invention relates to a construction and arrangement of hydraulic lift,
whereby I am enabled to dispense with the counter balance weights, chains, and
pullies usually employed for such lifts, and thus to simplify their structure and
action. For this purpose I connect the cylinder of the lift by a pipe with a
secondary cylinder fitted with a trunk piston, and I extend the trunk of this
piston and connect it to the piston or plunger of a third cylinder. Tho annular
space of the secondary cylinder is always in cominunication with the accumulator
or reservoir that supplies the working fluid, and the pressure of this fluid on the
annular area serves as the constant counterbalance to the ram and cage of the lift.
The third cylinder communicates with tho accumulator or reservoir, and also with
the discharge pipe by suitable cocks or valves, so that the piston or plunger of this
third cylinder can either be subjected to the pressure of the working fluid or
relieved therefrom. In the former case the pressure acting on the piston or plunger
of the third cylinder, as well as on the annular area of the piston in the second
cylinder, causes that piston to advance, forcing liquid into the lift cylinder, and so
causing the ascent of the lift. In the latter case when the piston of the third
cylinder is relieved from pressure, the lift descends, forcing liquid into the second
cylinder, and so causing its piston to retreat in opposition to the pressure on its
annular area, the fluid which was contained in the annular space being thus
returned to the accumulator or reservoir. By suitably proportioning the areas on
which the fluid acts, the relative pressures in the lift cylinder and in the accumulator
or reservoir may be proportioned as desired. In order to provide for loss by
leakage from the lift cylinder, I connect it or the second cylinder which communi-
cates with it to the accumulator or reservoir by a pipe provided with a cock or
valve which can be opened when required to admit fluid to the lift cylinder. In
cases where the other parts of the apparatus may require repair, the lift may, by
means of this pipe, be worked direct from the accumulator or reservoir, suitable
cocks or valves being provided.
The accompanying Drawing shews a longitudinal section of apparatus according
to my Invention. A is the secondary cylinder which communicates with the lift
cylinder by the pipe B, and is fitted with a trunk piston C. The trunk D of this
piston forms, or it may be attached to, the plunger of the third cylinder E. The
accumulator or pressure reservoir by means of a pipe F and branch G, communicates
with the annular space of the cylinder A, and by another branch H with the valve
box I. From the valve box a branch K opens for discharge, another branch L
leads into the cylinder E, and a third branch M communicates with the pipe B
leading to the lift cylinder. In the valve box I there may be a single slide or
separate cocks or valves of any known construction, by moving which the
cylinder E can be put in communication either with the supply pipe H or the
discharge K, the branch M being at that time closed. Or the branch M can be put
in communication with the supply pipe H or the discharge K, while the cylinder E
communicates with the discharge. O, P, and Q are cocks or valves by which the
cylinders A and E can be cut off from communication with the supply and with the
lift cylinder in case they should require repair. In ordinary working these cocks
or valves are open, but the branch M is closed. When the lift has to be raised the
valves in I are moved so as to admit the pressure. to act in E. This pressure along

page_text: with that on the annular area of the piston C causes the piston to move towards
the left, forcing water by the pipe B into the lift cylinder, and so causing the lift
plunger to rise. For lowering the lift the valves in I are shifted so as to open E to
the discharge K, and thereupon the weight of the lift and its plunger being resisted
only by the pressure on the annular area of C causes the piston C to move towards
the right, the lift and its plunger descending. By moving the valves in I so as to
keep the cylinder E open to the discharge, the lift may be worked by direct com-
munication through the pipe M.
Having thus described the nature of my Invention, and in what manner the same
is to be performed, I claim,-
The combination with the cylinder of a hydraulic lift, of a second cylinder
provided with a trunk piston, and a third cylinder having its plunger attached to
the said piston, and suitable cocks and valves, arranged and operating substantially
as and for the purposes herein set forth.
In witness whereof, I, the said Edward Bayzand Ellington, have hereunto set
my hand and seal, this Nineteenth day of April, in the year of our Lord
One thousand eight hundred and eighty one.
E. B. ELLINGTON. (L.S.)