Improvements in Hydraulic Elevators.
Year: 1891

page_text: COMPLETE SPECIFICATION.
[Communicated from abroad by JOHN GOULDING STAMP, Engineer, of 202, Main
Street, and CHARLES JOHN JAMES SEAMAN, of 200, Main Street, Clerk, both
of the City of Buffalo, in the County of Erie and State of New York, United
States of America.]
Improvements in Hydraulic Elevators.
I, HENRY HARRIS LAKE, of the firm of Haseltine Lake & Co., Patent
Agents, 45 Southampton Buildings, in the County of Middlesex, do hereby
declare the nature of this invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
This invention relates to pumping apparatus which is employed in connection
with hydraulic elevators for supplying water under pressure to the cylinder
whereby the system of pulleys and lifting cables of the elevator are actuated.
The compressed air escapes in small quantities with the water discharged from
the pressure chamber containing the compressed air and water, so that in time the
volume of compressed air becomes so small that its expansive force is insufficient
to operate the elevator.
In order to discharge the excess of water and permit the proper volume of
air to be restored to the pressure chamber, it has been customary to run the
elevator car up and down empty, but this requires considerable time and causes
delays. It has hitherto been sought to overcome this difficulty by connecting an
air pipe with the suction chamber of the pump, so as to mix the water with the
air before its delivery into the pressure chamber and thus replace the loss of air;
but unless the air supplied to the pump is properly regulated, the volume of air
so drawn into the pump cylinder will be excessive, in which case the air acts as
a cushion which impairs the action of the pump and sometimes requires the pump.
to be stopped to allow the air to escape thus causing annoying interruptions of
the elevator service.
The object of the said invention is to so organize the pumping apparatus that
when the volume of compressed air in the pressure chamber becomes deficient
from any cause, the proper quantity of air may be readily restored without
regulating the water supply to the pump or requiring the elevator to be run
empty to discharge the surplus water from the pressure chamber.
In the accompanying drawings,
Figure 1 represents a sectional elevation of a hydraulic elevator plan embodying.
my improvement.
Figure 2 is a vertical section of the air injector, on an enlarged scale.
Figure 3 is a cross section in linea a Figure 2.
Like letters of reference refer to like parts in the several figures.
A represents the closed pressure chamber containing water and compressed air
and A is the pipe whereby the water is delivered under pressure from the
chamber A to the usual actuating cylinder of the chamber. This actuating
cylinder and the system of pulleys and lifting cables operated by the same are not
shown in the drawings and may be of any ordinary construction. B is the pump.
and 6 the pipe through which water is delivered by the pump into the lower portion
of the pressure chamber A. C is an open water tank from which the pump draws.
its supply through the suction pipe D. The latter may be provided with a valve d
for shutting off the supply of water to the pump for making repairs or for other
purposes.
E is an auxiliary pipe leading from the pressure tank A' to the suction pipe D.
This auxiliary pipe enters the pressure chamber below the water level and is pro-
vided with a cut-off valve e. "F is an air injector connected with the auxiliary

page_text: pipe E and whereby air is commingled with the water flowing through said pipe.
This air injector consists, preferably of a pipe f.which enters a shell or casing el
arranged in the auxiliary pipe E and extends downwardly a short distance into the
upright portion of the latter, the pipe f.being.separated-from the surrounding water
pipe by an annular space through which the water passes. The injector pipe fis
provided with-a,depending branch having a valve f for regulating the quantity
of air admitted to the injector. Upon opening the valve e of the auxiliary pipe E
and the valve of the injector, the water passes through the pipe E into the
supply pipe of the pump, producing a vacuum at the mouth of the injector pipe f
whereby air is drawn into the auxiliary pipe and mixed with the water supplied to
the pump. A perforated diaphragm is preferably arranged in the pipe E at the
mouth of the injector pipe to restrict the passage of the water at this point and
increase the force of the suction.
In the ordinary operation of the apparatus, the valve of the suction pipe b is wide
open and the valves of the injector pipe fand the auxiliary pipe E are closed, so
that the water in the pressure chamber A is shut off from the pipe E and the
injector rendered inoperative.
When the volume of air in the pressure chamber becomes deficient, the valve of
the auxiliary pipe E and the regulating valve of the injector pipe are opened. A
portion of the water in the pressure chamber is now forced into the pipe E and in
its passage through the same is mixed with air. The water charged with air is
delivered into the suction pipe D of the -pump and forced by the latter into the
pressure chamber, whereby the volume of air in the latter is increased, the air
rising above the surface of the water into the air space in the upper part of the
chamber. As the water for operating the air injector is drawn from the pressure
chamber, the latter is gradually relieved of its surplus water, and the water so
discharged is replaced by the air and partly by the water forced into the chamber.
When the proper proportion of water and air is established in the pressure
chamber, the valves of the auxiliary pipe E and injector F are closed.
proper volume of air is thus readily restored in the pressure chamber, when
necessary, without requiring the elevator to be run up and down numerous times
and as the flow of the water to the pump is unrestricted, the pump always has
a sufficient supply to prevent air from being delivered into the pump in such
large quantities as to cushion the pump and impair its action.
The
It is obvious that any other suitable air injecting device may be employed instead
of that above described and shown in the drawing.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed as communicated to me
by my foreign correspondents, I declare that what I claim is :-
First. In an hydraulic elevator, the combination with a pressure chamber
containing air and water and a pump for delivering water to said chamber, of a
suction pipe connecting the pump with the source of supply, an auxiliary pipe
leading from the pressure cylinder to said suction pipe, and an air injector arranged
in said auxiliary pipe whereby the water in the latter is mixed with air, sub-
stantially as set forth.
Second. In an hydraulic clevator, the combination with a pressure chamber
containing air and water, and a pump having its delivery pipe connected with the
pressure chamber of a suction pipe connecting the pump with the source of supply,
an auxiliary pipe connecting said suction pipe with the pressure cylinder and
having a cut-off valve and an air injector arranged in said auxiliary pipe and
provided with a valve for regulating the supply of air to the injector, substantially
as set forth.