Improvements in Pumps.
Year: 1892

page_text: Date of Application, 4th July, 1892-Accepted, 1st Oct., 1892
Improvements in Pumps.
A communication from abroad by OTIS BROTHERS & Co., of 38, Park Row,
New York, in the United States of America, Manufacturers.
We, AMERICAN ELEVATOR COMPANY (Incorporated) of 4 Queen Victoria
Street, in the City of London, Manufacturers, 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 that class of pumps in which there are two or more
cylinders and pistons communicating with each other and in which the stream of
water forced forward or drawn outward by one or the other of the pistons, flows
through a port in the piston that is not actively moving the water, for at least a
part of its stroke, such a pump being described in an application for Letters Patent
No. 287 of 1892.
In such case the displacing action of any piston pushing the water before it or
drawing the water with it is equal to the superficial area of that piston, while the
channel through which the water must pass through the other piston or pistons
necessarily is less in area than the working area of the actuating piston so that
there is an obstruction to the flow of the water resulting in pounding or hammering,
and obstructions to the ready smooth and effective action of the pump.
To overcome these objections the construction illustrated in Figures 1 and 2 of
the drawing is employed although it will be understood that these figures show only
one method and arrangement in which the improvement may be embodied.
In the construction shown in the drawing there are two cylinders D, D', practically
connected together and enclosed in one casing H having a dome like cap G
affording a channel 7 between the two cylinders. As shown, each cylinder is a
sleeve projecting from a plate v which is clamped between the casing H and
its cap.
The water is assumed to enter the casing H, and the cylinder D through the
inlet 10 and outward from the cylinder D' and casing through port 11 and when
the upper piston K' is moving to the left the water flows through a port 6, in the
piston K, the valve a opening to permit the passage of the water through the
port 6 into the channel 7 and to the cylinder D, the port 6 of which is then closed
by the seating of the valve a of said piston, so that the water in front of said valve
is carried out through the discharge opening 11.
It will be seen that the water discharged through the opening 11, and forced
forward by the piston K' is in volume equal to the total area of the piston K'
multiplied by its stroke, and that this volume of water must either pass through
the small port 6 of the piston K or a partial vacuum will result. This would
result in hammering pounding noise and obstructions to the regular movements of the
current and means are therefore provided whereby to compensate for the necessarily
reduced area of the ports through which the water must flow through the pistons.
To this end there are made in some part of the channel, ports h, closed by
spring valves i, i, one communicating directly or indirectly with each one of the
cylinders D D'
When the parts are in the position shown in Figure 1, and operating as described
as the full volume of water cannot pass through the port 6, of the lower piston K,
the lower valve i closing the port (communicating with the cylinder D, through the
intermediate surrounding space) will open and permit the water to flow so as to
supply the entire volume that can be moved by the upper piston K. In like
manner when the upper piston K' is moving to the right and the lower piston K, is
also moving to the right and forcing a volume of water before it, greater than can

page_text: readily pass through the port 6, of the upper piston K', then in that case the upper
valve i, will open the upper port h, and let the surplus of water pass towards
the port 11.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed (as communicated to us
by our foreign correspondents) we declare that what we claim is :-
The combination in a duplex or multiple pump of communicating cylinders and
pistons having openings and valves and auxiliary openings or passages between the
main inlet and outlet openings, provided with valves arranged to operate sub-
stantially as set forth.
PHILIP M. JUSTICE, Fel. Chart. Inst. P.A.,
55 & 56, Chancery Lane, London, Agent for the Applicants.