Year: 1887

page_text: Date of Application, 8th Dec., 1887
Complete Left, 27th June, 1888
Complete Accepted, 27th July, 1888
I THOMAS POWNALL FORD of 4 Queen Victoria Street in the City of London,
Engineer, do hereby declare the nature of this invention to be as follows:-
My Invention relates to that kind of hydraulic lift in which the cage is suspended
by a chain or rope passing round an overhead sheave, and is actuated by a piston
working in a vertical cylinder with a column of water above and below it. And the
invention relates first to the valve gear for controlling the admission of the water to
the main cylinder and its circulation from one end of said cylinder to the other; and
it has for its object to enable plug or slide valves to be used and at same time prevent
leakage of the water owing to grit preventing the valves being properly seated which
leakage, if it occurred when the cage is landed, would raise the hoisting sheave of the
main piston off the suspension rope or chain and so cause accidents. Cup leather
valves, which would obviate this leakage, cannot however be used if exposed to high
pressures (say 700 lbs per square inch) such as are used in this class of lift, as they
are liable to be forced through and be cut in passing over the openings in their seats.
The Invention consists in the combination with valves of the plug or sliding type
sustaining the bulk of the pressure from the supply and controlling the circulation of
water from one end of the main cylinder to the other, of an auxiliary cup leather valve
which is operated concurrently with, and by the same hand rope gear as, the main
valves; this cup leather valve being exposed when passing over the ports in its seat,
only to a very diminished pressure which is insufficient to injure the cup leather valve,
the office of this valve being merely to arrest any leakage that might occur at the
main valves when those valves are closed and when, consequently, the cup leather
valve is not covering the ports in its seat. The main valves which may be of the
conical plug form, comprise a valve controlling the water from the supply to what I
term a circulation chamber, a similar valve controlling the passage of water from the
circulation chamber to the pipe leading to the upper end of the main cylinder; these
two valves being opened simultaneously by the same gear. In its most simple form,
this may consist of a double incline cam placed between, and acting directly on, the
valves, the cam being carried by the spindle of a cup leather piston valve working

page_text: within the circulation chamber as a cylinder, and controlling circulation or by-pass
orifices, the cam and valve being operated through rack and pinion gear or other
mechanical motion from the hand wheel rope passing through the car. When the cam is
moved in the one direction for the purpose of opening the valve from the supply it will
also open the other valve to the upper end of the main cylinder, and at same time raise
the cup leather valve wholly above the orifices or ports which it controls, and when
the cain is moved in the opposite direction it will permit the valve controlling the
supply to be closed and will afterwards open the valve to the main cylinder and same
time move the cup leather valve to a position between two sets of by-pass or circulation
ports which permit the water from the upper end of the main cylinder to circulate
from the upper to the lower end of said cylinder.
Instead of operating the plug valves by a cam motion between them and within the
circulation chamber they may be operated by an external system of rods and levers
connected to the outer ends of their stems and operated by a rack and pinion or other
mechanical motion from the same hand wheel as that which operates the cup leather
piston valve, the arrangement being such that the valves are in no case actuated by
the water pressure.
The invention has secondly for its object to prevent the application of pressure to
the underside of the piston in consequence of leakage; to compensate for the difference
of area of the two ends of the main cylinder due to the displacement of the piston rod,
and to economise power by enabling low pressure water to be automatically supplied
to make up the deficiency when the water is circulated from the upper to the lower
end of the cylinder. To this end the invention consists in causing the exhaust pipe to
discharge into an open tank as near as possible at the level of the bottom end of the
cylinder into which the mouth of the pipe dips below the level of a supply of liquid
maintained therein so that the deficiency in volume of the circulating water will be
made up by water forced back by atmospheric pressure through the exhaust pipe to
the main cylinder.
The exhaust pipe is therefore always open to the tank instead of being closed by a
valve as heretofore, so that were leakage past the valves, or main piston to occur when
the cage is landed, no pressure can be generated against the lower side of the main
piston, which cannot consequently rise and throw the sheave off the ropes.
My invention relates thirdly to an automatic regulator for checking tlie flow of
water both on the ascent of the main cylinder under a light load or on its descent under
a heavy load. The action of this regulator is due to the inertia of the column of water
itself and it consists in a plunger placed in a cylinder in line with the column of
water so that the latter will impinge directly against the end of the plunger and be
thereby diverted from its direct course through by-pass passages in the cylinder which
lead the water transversely across a part of the plunger that acts as a balanced valve
controlling the flow of the water. The plunger is held by a weighted lever or its
mechanical equivalent in its normal or mid position so as to give a full passage to the
water but on the water striking the end of the piston with a velocity exceeding a
predetermined limit the weight will be overcome and the flow of water checked, the
action being similar in whichever direction the water is flowing.
Datod this 8th day of Draamh 1007
THOS. P. FORD.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: improves in nyurate it.
I, THOMAS POWNALL FORD, of 4, Queen Victoria Street, in the City of London,
Engineer, do hereby declare the nature of this invention and in what manner
the same is to be perforined, to be particularly described and ascertained in and
by the following statement :-
--
My Invention relates to that kind of hydraulic lift in which the cage is suspended
by a chain or rope passing round an overhead sheave and under a sheave carried at
the upper end of a piston working in a vertical cylinder with a column of water above
and below it whereby the lift is actuated. And the invention relates first to the
valve gear for controlling the admission of the water to the main cylinder and its
circulation from one end of said cylinder to the other; and it has for its object' to
enable plug or slide valves to he used and at same time avoid leakage of the water
owing to grit preventing the valves being properly seated which leakage if it occurred
when the cage is landed would raise the hoisting sheave of the main piston off the
suspension rope or chain and so cause accident.
The Invention consists in the combination with valves of the plug or sliding type
sustaining the bulk of the pressure from the supply and controlling the circulation of
water from one end of the main cylinder to the other, of an auxiliary cup leather
valve which is operated concurrently with, and by the same hand rope gear as,
the main
valves. Cup leather valves which are not liable to leakage like metal valves, cannot
however be used if exposed to high pressures (say 700 lbs. per square inch) such as
are used in this class of lift, as they are liable to be forced through, and be cut in
passing over, the openings in their seats. In the combination of my invention the
cup leather valve is exposed, when passing over the ports in its seat, only to a very
diminished pressure which is insufficient to injure the cup leather valve, the office of
this valve being merely to arrest any leakage that might occur at the main valves
when all the valves are closed.
The Invention has secondly for its object to prevent the application of pressure to
the underside of the piston in consequence of leakage; to compensate for the difference
of area of the two ends of the main cylinder due to the displacement of the piston
rod; and to economize power by enabling low pressure water to be automatically
supplied to make up the deficiency when the water is circulated from the upper to the
lower end of the cylinder.
My Invention relates thirdly to an automatic regulator or governor for checking
the flow of water both on the ascent of the main cylinder under a light load, or on its
descent under a heavy load.
Reference is to be had to the accompanying drawings forming part of this specifi-
cation;
wherein figure 1 is an elevation, partly in section, of the main cylinder and
valve gear of a hydraulic lift of the class to which my invention relates. Figure 2
is a vertical section through the cup leather valve separately. Figure 3 is a vertical
section of the regulator. The same letters of reference indicate the same narts in all
the figures.

page_text: The main valves A, B, which may be of the conical plug form, comprise a valve A
controlling the water from the supply to what I term a circulation chamber C, and a
similar valve B controlling the passage of water from the circulation chamber C to
the pipe D that leads therefrom to the upper end of the main cylinder E, these two
valves A B, being operated by gear from the hand wheel rope passing through the
car. F is a cup leather piston valve working within the circulation chamber as a
cylinder, and controlling circulation or by-pass orifices y, the said valve being operated
simultaneously with valves A and B through rack and pinion or other gear.
i
The valve gear shewn consists of levers a b connected with the stems of valves A B
respectively, both the levers being connected with the same rack rod I gearing with
a pinion on the axis of the pulley K over which runs the hand rope. The lever a is
connected to the stem of valve A by a pin and slot connection a¹ which permits of
motion of the lever towards the valve A although the latter has closed on its seat.
The lever is a bell crank lever and is connected with the stem of valve B through a
link &, the centre of motion 12 of the lever being opposite the end of the valve so
that the latter will be closed on the lever arm link and valve spindle coming into line,
and will be opened by angular motion of the lever either way from the position
shewn. The cup leather piston valve is carried on a spindle f having rack teeth on
its upper end and gearing with a pinion on the same axis with pinion i.
The operation is such that when the valve A from the supply is opened the valve B
is also opened to admit water to the upper end of the main cylinder E, the cup leather
valve F being then raised wholly above the orifices or ports g which it controls; and
when by motion in the opposite direction the valves A B, are closed and the valve B
alone opened by the continued motion of lever b, the cup leather valve will be moved
to the position shewn in figure 3, between the two sets of by-pass or circulation
ports g which permit the water to circulate from the upper end of the main
cylinder through pipe, D, chamber C, by-pass g', to pipe H leading to the lower end
of said cylinder.
The Invention consists secondly in causing the exhaust pipe H connected to the
lower end of the main cylinder E to discharge into an open tank L (as near as possible
at the level of the bottom end of the cylinder E) into which the mouth of the pipe H
dips below the level of water retained therein so that the deficiency in volume of the
circulating water will be made up by water forced back by atmospheric pressure
through the exhaust pipe to the main cylinder. The exhaust pipe is therefore always
open to the tank instead of being closed by a valve as heretofore, so that were leakage
past the valves or main piston to occur when the cage is landed no pressure can be
generated against the lower side of the main piston which cannot consequently rise
and throw the sheave off the ropes.
The action of the regulator or governor which forms the subject of the third
improvement, is due to the inertia of the column of water itself, the flow of which it
is required to control. It is exceedingly sensitive in its action, which is a primary
consideration in a governor, owing to the absence of rods-sliding in stuffing boxes as
in other regulators and the consequent reduction of friction of the moving parts, so
that the regulator quickly responds to fluctuations of pressure.
The regulator consists in a plunger valve N fitted to work in a cylinder M in line
with the column of water in the pipe D to be regulated, so that the water will impinge
directly against the end of the plunger valve. The cylinder is formed with by-pass
passages O, P, communicating with the ports o, p, controlled by the plunger which
acts as a balance valve controlling the flow of water transversely across the cylinder
from port o to port p or vice-versa. The plunger is held in its normal or midposition
by a yielding force so as to give a full passage to the water, but on the water striking
the end of the piston with a velocity exceeding a predetermined limit, the force will
be overcome and the plunger moved so as to check the flow of water at the ports op,
the action being similar in which-ever direction the water is flowing.
.1
"
The preferred means of controlling the plunger valve consists of a rock lever R
turning loose on an axis 7, one end of the lever engaging in a slot in the plunger and
the other end located between a pair of opposing springs ss, the whole being contained

page_text: within a closed casing. The power of the springs is regulated by means of adjusting
screws, this power necessarily differing in the two springs inasmuch as the water
on its admission above the piston has to overcome the back pressure due to friction
and the load, whereas whilst circulating, the back pressure is very much diminished.
The motion of the plunger valve either way from the mid-position is opposed by the
one or other of the springs, according to the direction in which the water is flowing.
In the figure, the water is supposed to be flowing in the direction of the arrows.
The motion. of the plunger in either direction is limited by the lever abutting against
the top or bottom of the slot in the casing in which it moves.
Having now particularly described and ascertained the nature of the said invention,
and in what manner the same is to be performed, I would observe that it has hereto-
fore been proposed to provide an auxiliary pipe controlled by a valve, in addition to
the ordinary escape pipe said auxiliary pipe connecting the main cylinder with a tank
in order to permit the return of water to the main cylinder to make up for the
deficiency consequent on the displacement of the piston rod, but such auxiliary pipe
did not permit the escape of water to the exhaust tank; Further, it is not new in
principle to actuate a governor by the momentum of the column of water to be
regulated, and I do not therefore, lay any claim thereto; but declare that what I
claim is;
1. In a hydraulic lift of the type specified, the combination with water supply and
circulation valves A, B, of the plug or sliding type and the chamber ( connected
with the main cylinder as described, of a cup leather piston valve F controlling the
passage from chamber to the lower end of the main cylinder and acting in con-
junction with the valves A, B, as a second seal to prevent leakage, both sets of valves
being operated by the same gear, substantially as specified.
2. The combination with the valves A, B, and of the rack and pinion gear and
levers for operating such valves, and consisting of the piston rack rod fpinions fr
and i, rack rod and levers a 1, connected to rack rod 1 and to the stems of
valves A, B, substantially as specified and shewn in Figure 1.
3. A hydraulic lift of the type specified wherein open communication is at all times
maintained between the lower end of the vertical main cylinder and an open tank at
about the same level, by means of the exhaust pipe dipping into water in said tank,
so that the said exhaust pipe shall perform the triple function (a) of exhausting the
waste water in the usual manner; (b) of affording a free exit for leakage water and so
preventing the application of pressure to the underside of the piston; and (c) of
permitting the return of low pressure water to compensate for the difference of area
of the two sides of the piston due to the displacement of the piston rod, all as
specified.
4. In a hydraulic lift, a double acting automatic regulator or governor for checking
both the supply and circulation of the water and consisting of a plunger valve working
in a cylinder interposed axially in line with the moving column, the cylinder being
provided with by-pass passages or ports across which the valve works, said valve
being held by a yielding force against the momentum of the coluun of water
impinging against it, as described.
Dated this 27th day of June 1888.