IMPROVEMENTS IN HYDRAULIC LIFTS
Year: 1884

page_text: "
I ALEXANDER CLARK of 37 Lancaster Gate, Hyde Park, in the County of
Middlesex, Engineer, do hereby declare the nature of the said Invention for
IMPROVEMENTS IN HYDRAULIC LIFTS," to be as follows:-
My Invention has for its object to avoid the counterbalance weights and to
counterbalance the lift by hydraulic pressure without consequent waste of water.
My Invention consists in supporting the lift cage upon two rams working in
independent cylinders whereof one termed the counterbalance cylinder is in
continuous communication with the tank, accumulator, main, or other source of
water under pressure, the communication with the other or working cylinder being
controlled by a valve in the usual way. The combined areas of the two rams is
sufficient for raising the lift cage with its load, but the area of the counterbalance
ram alone is not sufficient for the support of the cage.
The cage is raised by the water acting on both rams when the admission valve
of the working cylinder is opened, and when the water in the working cylinder is
released to the waste the weight of the cage overcomes the pressure beneath the
counterbalance ram which consequently forces the water out of its cylinder back to
the accumulator, tank, main, or other source of pressure without loss.
Dated this First day of January 1884.
COMPLETE SPECIFICATION.
I, ALEXANDER CLARK of 37 Lancaster Gate Hyde Park in the County of
Middlesex Engineer do hereby declare the nature of the said Invention for
IMPROVEMENTS IN HYDRAULIC LIFTS," and in what manner the same is to be
performed, to be particularly described and ascertained in and by the following
statement:
My Invention relates to improvements in hydraulic lifts and has for its object
to avoid the use of counterbalance weights and to counterbalance the apparatus by
hydraulic pressure without consequent waste of water.
Di

page_text: My Invention consists in mounting or supporting the lift cage upon two rams
working in independent cylinders whereof one, termed the counterbalance cylinder,
is in continuous communication with the tank, accumulator, main, or other source
of water under pressure, while the communication with the other, or working
cylinder, is controlled by a valve in the usual way. The combined areas of the
two rams is sufficient to raise the lift cage with its load, but the area of the
counterbalance ram alone is not sufficient for the support of the cage.
The cage is raised by the water acting on both rams when the admission valve
of the working cylinder is opened, and when the water in the working cylinder is
released to waste the weight of the cage overcomes the pressure beneath the
counterbalance ram which consequently forces the water out of its cylinder back
to the accumulator, tank, main, or other source of pressure without loss.
In the accompanying Drawings, Figure 1 is an elevation of a lift constructed in
accordance with my Invention, while Figure 2 is a cross section of the rams and
cylinder on line 1-1.
a a¹ is the working cylinder, and its ram, b b¹ the counterbalance cylinder and
its ram, c, is a branched supply pipe to the two cylinders, d the valve for controlling
the admission of water to and its discharge to waste from the working cylinder,
and the cage of the lift.
In operation the valve d is opened to admit water to the working cylinder a
whereupon the combined pressure upon the two rams suffices to raise the cage and
its load. To enable the cage to fall the valve d is opened to waste and the weight
of the cage thereupon overcoming the pressure in the counterbalance cylinder b
forces the water in said cylinder b back through pipe c to the accumulator or
tanke or other source of supply.
In the Drawing the working ram is shown of larger area than the counter-
balancing ram but will of course be understood that the relative size of the rams
will depend on the work to be performed.
Having now particularly described and ascertained the nature of the said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
The combination, with the cage of an hydraulic lift, of a pair of rams working
in independent cylinders whereof one is in continuous communication with the
source of supply under pressure and the other is provided with means for enabling
the admission of water to the cylinder and its discharge to waste to be controlled,
substantially as shewn and described for the purpose specified.
Dated this Twenty-fifth day of September 1884.