IMPROVE- MENTS IN HYDRAULIC LIFTS
Year: 1883

page_text: LETTERS PATENT to William Humble Johnson of Palace Chambers
Westminster in the county of Middlesex for an Invention of "IMPROVE-
MENTS IN HYDRAULIC LIFTS"
PROVISIONAL SPECIFICATION left by the said William Humble Johnson
at the Office of the Commissioners of Patents on the 13th March 1883.
WILLIAM HUMBLE JOHNSON of Palace Chambers, Westminster in the County
of Middlesex "IMPROVEMENTS IN HYDRAULIC LIFTS"
My invention relates to hydraulic lifts in which water pressure is employed, as
described in the specification to Ellington's Patent of 9th December 1880, No: 5149,
for counterbalancing the weight of the cage and plunger, and for compensating the
variation of load resulting from the greater or less protrusion of the plunger, the
object which I have in view being to simplify construction, to economise space and
to obtain facilities for erection and for repair, when necessary. For this purpose,
I make the counterbalancing cylinders and plungers of annular kind, surrounding
the lift cylinder and its plunger, so that the whole apparatus is accommodated on
one foundation within the space of the lift shaft, and without requiring external
pipe connections. The particular arrangements of the counterbalancing cylinders
and plungers may be varied to suit various conditions. I will describe several
arrangements as examples of the constructions which I adopt. In cases where the
service pressure has to be intensified for operating in the lift cylinder, I arrange
the apparatus as follows. I make the upper part of the lift cylinder to act as a
stationary differential plunger, its upper end being of less diameter than its lower
end. On this, as a plunger, I fit with packing an annular cylindrical plunger,
which is either sufficiently heavy itself, or can be loaded so as to counterbalance,
to such extent as is desired, the cage and plunger of the lift. This annular plunger
works through packing in the bottom of a stationary cylinder which has the usual
valve box, by which it can be supplied from the service or permitted to discharge.
The annular plunger above referred to is made with sufficient internal capacity to
supply the lift cylinder with which it is in constant communication by passages
through the stationary plunger. When water under the service pressure is

page_text: admitted to the stationary cylinder, it presses down the annular plunger, and
this, moving along the differential stationary plunger, causes its internal contents
to pass into the lift cylinder, raising the lift with a pressure increased above that
of the service according as the external area of the annular plunger exceeds the
difference of area of the stationary plunger on which it works. When the stationary
cylinder is opened to discharge, the weight of the cage and plunger of the lift
causes the annular plunger to rise, the contents of the lift cylinder returning into
the interior of the annular plunger. When it is desired to employ in the lift
cylinder a pressure less than that of the service, the construction above described
is arranged in an inverted condition, the high pressure service communicating with
the interior of the annular plunger (which, in this case, moves through the top
of the stationary cylinder) and the lift cylinder being in constant communication
with the lower part of the stationary cylinder. When, instead of a heavy or loaded
plunger, it is desired to employ chiefly water pressure for balancing the dead load,
I use the construction last described, but fit the annular plunger so as to move not
only through the top of the stationary cylinder, but also through the bottom of an
upper stationary cylinder, which is in communication with the service, or with a
water tank which may give only a moderate pressure, in which case, I pro-
portionally enlarge the upper end of the annular plunger. The stationary lift
cylinder need not be made differential when the pressure acting in the lift cylinder
is to be the same as that of the service. In this, and in several of the cases
previously described, the lift plunger itself may pass through the annular plunger
and the stationary cylinders, without extending the upper part of the lift
cylinder throughout the whole length of the counterbalancing and compensating
apparatus.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said William Humble Johnson in the Great Seal Patent Office on the
10th September 1883.
WILLIAM HUMBLE JOHNSON of Palace Chambers Westminster in the county
of Middlesex "IMPROVEMENTS IN HYDRAULIC LIFTS"
My invention relates to hydraulic lifts in which water pressure is employed, as
described in the Specification to Ellington's Patent of 9th December 1880, N° 5149,
for counterbalancing the weight of the cage and plunger, and for compensating the
variation of load resulting from the greater or less protrusion of the plunger, the
object which I have in view being to simplify construction, to economise space, and
to obtain facilities for erection and for repair, when necessary. For this purpose,
I make the counterbalancing cylinders and plungers of annular kind, surrounding
the lift cylinder and its plunger, so that the whole apparatus is accommodated on
one foundation within the space of the lift shaft, and without requiring external
pipe connexions. The particular arrangements of the counterbalancing cylinders
and plungers may be varied to suit various conditions. I will describe several
arrangements as examples of the constructions which I adapt referring to the
accompanying drawings which are vertical sections shewing in each case part of
the lift cylinder A and plunger B with hydraulic balancing apparatus according to
my invention.
Fig. 1 shows an arrangement that may be used when it is desired to intensify
the service pressure, so as to have a greater pressure acting in the lift cylinder.
In this case, part of the lift cylinder A at A' A' is made of differential area, and on
it works an annular plunger C, sufficiently heavy in itself, or loaded sufficiently to
counterbalance the weight of the lift plunger and cage or any desired portion
thereof. The differential space of the plunger C when it is at the extreme of its
upstroke has capacity enough to contain all the liquid required to raise the lift
plunger B. Passages at a make communication between the lift cylinder and the
interior of the plunger C. A stationary cylinder D communicates at d through a
suitable valve box with the accumulator or supply reservoir and with the discharge,
and the plunger C works through packing at the bottom of D. On admitting the
liquid under pressure to D, the plunger C is forced downwards and, owing to the
difference of area of A¹ and A³, liquid at increased pressure is forced through a
from the interior of C into the lift cylinder A, raising the plunger B and the cage.
As, by the descent of C, the column of liquid pressing on it increases propor-
tionally to the ascent of the plunger B, the variation of load due to the greater or
less protrusion of B is compensated throughout the stroke. On opening d to the
discharge, the weight of the cage and plunger B causes them to descend, forcing
liquid through a into C and causing C to rise. In the arrangement shewn in
fig. 2, the hollow plunger C works through packing not only in the cylinder D, but
also in a lower cylinder E communicating at a with the lift cylinder A. A
passage c leading to the interior of C is in constant communication with the
accumulator or pressure reservoir, so that, in addition to the weight of C, this
pressure acts as counterbalance, d being as before in communication with the
supply and discharge valve box. Obviously the connections of c and d may be
inverted, d being in constant communication with the accumulator, while c com-
municates with the valve box. By a modification of this arrangement, shewn in
fig. 3, a low pressure supply constantly communicating with D through d and
acting on the enlarged piston area of C, serves, in addition to the weight of C for
counterbalance, the working being effected by supply and discharge through c.

page_text: Fig 4 shews another modification of the arrangement shewn in fig. 2, the parts, in
this case, being so arranged that the cylinder C works on the lift plunger B. In
the arrangement shewn in fig. 5, weights W placed on C serve for counterbalance,
the working being effected through the passage d. By the arrangement shewn in
fig. 6, C is made of sufficient weight or is loaded sufficiently for counterbalance, the
working being effected by high pressure liquid through d.
Having thus described the nature of my invention and in what manner the same
is to be performed, I claim in respect of Hydraulic Lifts in which the weight of
the cage and lift plunger is wholly or partly counterbalanced by hydraulic
pressure,―
Constructing the counterbalancing and intermediately working cylinders and
plungers in annular form, surrounding the lift cylinder, substantially as and for the
purposes herein set forth.
In Witness whereof, I, the said William Humble Johnson, have hereunto set
my hand and seal this Sixth day of September in the year of our Lord, one
thousand, eight hundred and eighty-three.
TOLETT
TATHAT
W HUMBLE JOHNSON