Improvements in and relating to Vacuum Pumps.
Year: 1891

page_text: Date of Application, 19th May, 1891-Accepted, 20th June, 1891
COMPLETE SPECIFICATION.
[Communicated from abroad by ADOLPH BERRENBERG, of Somerville, Massa-
chusetts, United States of America, Engineer, and WILLIAM EMERY
NICKERSON, of the United States of America.]
Improvements in and relating to Vacuum Pumps.
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 the construction, arrangement, scaling and method of
co-working the cylinders of a vacuum pump.
The object being to simplify the mechanism and to secure superior results.
This object I attain by the devices shown in the accompanying drawings, in
which―
Figure 1 is a view in which some of the parts are shown in vertical section and
some in elevation.
Figure 2 is a plan of the device with the top removed.
In the drawings, A represents a tank made large enough to hold one or more
pump cylinders and their connections. This tank is to be filled with oil or other
suitable fluid and if it is large it must be properly braced and stayed.
Near the bottom of this tank a crank shaft H is hung on suitable housings and
bearings, as shown. The shaft H passes out of the tank through the stuffing-box H',
then through the oil S2 in the pocket H' to a second stuffing-box H2, and has
driving gears not shown.
Within the oil tank four cylinders B, C, D, E, are shown; supported respectively
upon base pieces B, C, D, E²; these cylinders are substantially alike, and a
description of one, E, will do for all.
The cylinder proper E, coned at the top as shown, is supported on a base ³,
and has a piston E³, also coned, connected by a pitman E to its crank, on the crank
shaft H. At the top of the cylinder E a downwardly closing valve E is placed.
A port indicated by dotted lines at E is made in the side of the cylinder. As has
already been stated the cylinders B, C, D, and E, and their pistons, valves and
ports are alike, and therefore require no further description, except to refer to the
connections with the inlet and outlet pipes, and to their co-working.
The system of pipes and valve connections will now be described; P is a pipe
leading from the article to be exhausted; this pipe is connected to the interior of
cylinder B by a branch P (Fig. 2), which terminates in the port B³ (see Fig. 1),
and to the interior of the cylinder C, by a bend P² (Fig. 2) which terminates in
the port C (Fig. 1).
The pipe R is connected to the valves in the tops of the cylinders B and C (their
valves being in all respects like the valve E' shown in section in Fig. 1), thence
the pipe turns downward and rearward, as shown, and is connected to the
ports D and E in the cylinders D and E. The pipe R is connected by a pipe R
to an air dome A' (see Fig. 1).
The pipe T connects at T with the valve D₁ in the top of the cylinder D, and
at T with the valve E in the top of the cylinder E, thence the pipe T passes out
of the tank and terminates at T over a return box H, which is connected to the
tank, as shown, having a downwardly closing valve attached to a float H. The
top of the entire tank A, may be covered with oil as indicated.
The operation of this pump is as follows:-The tank is nearly filled with oil, or
other suitable fluid, that is, a sufficient quantity is put in it to cover all of the parts,

page_text: but leaving a space above, as shown. The. top may be covered with oil for the
purpose of sealing the joints.
Now as the crank shaft H rotates, the pistons in the cylinders B and D descend,
and those. in C and E ascend.
ŷ
The pumping action is as follows:-Supposing that a half turn of the crank shaft
is made, a vacuum is formed in the cylinder B, while air is forced out of cylinder C,
through the pipe R, R and R' to the dome A5 a vacuum is formed in cylinder D,
and air is forced out of cylinder E, through the pipe T to the open air. At the
completion of the half turn of the crank shaft the ports B and D in the exhausted
cylinders B and D will be open and air will flow to B through the pipe P from the
article being exhausted, and air will flow into the cylinder D, through the pipe R,
from the cylinder B-and the articles being exhausted, and through the pipes R³
and the lower part of the pipe R from the dome A and the upper part of the tank,
that is from the part of the tank not occupied by the oil. In this action the pump
performs another important function, namely-it, by exhausting from above the oil 1
in the tank causes the deacration of the oil in the said tank and renders it a suitable
fluid for filling the spaces around the pump cylinders and their connections, for the
purpose of preventing any air or other vapor from entering the vacuum spaces
within the cylinders and their connections.
Now supposing the crank shaft to make another half turn, the ports 15 in 2
cylinder B, and D in cylinder D, will be closed, and the enclosed air will be forced
out, the air from B going to the dome A, and from D through the pipe T, to the
air;
open while this is going on, the cylinders C and E are exhausting, C through
pipe P from the article being exhausted, and the cylinder E through the pipe R+, R$
from the dome A³. This comprises the work done by a full turn of the crank 2
shaft, and repetition of the rotation simply repeats the pumping action of all the
cylinders.
As the work goes on the vacuum in the article being exhausted and in the dome
and in the space above the oil in the tank is improved until the desired minimum of
air tension is attained.
All of the cylinders are supplied with a small quantity of oil at cach stroke of
the pistons, the oil passing through small ports made in the sides of the cylinders
for that purpose, one of which ports is shown at E, Fig. 1. These oil ports are
covered and uncovered by the piston itself the same as the air ports B³, C, D'
and Es are.
The excess of oil is forced out together with the air at each upward 3
stroke of the piston. The oil thus admitted serves to completely expel the air from
the cylinders at each upward stroke of the piston. This oil flows from cylinders B
and through the pipe R', R, to the cylinders D and E, and thence through the
pipe T to the box H, whence the flow back into the tank A is regulated by the
Hoat H and valve h.
In the above description of the working of this pump it is seen that the several
pistons and cylinders co-work to produce the result; thus the piston D³ produces a
vacuum for the cylinder B to discharge into, while the piston E³ produces a vacuum
for the cylinder C to discharge into. By this co-working of the individual pumps
very rapid and efficient work is accomplished.
The above described arrangement, except as to co-working, may be modified so
as to apply to a single cylinder. For instance take the cylinder E, and let the
exhaust pipe R run directly to the articles to be exhausted, say lamps, and have
the delivery pipe T, T³, unconnected with any other pump and pass directly to the
oil box H; now this single cylinder would become, for most purposes, a very
efficient pump..
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed as communicated to me by
my foreign correspondent I declare that what 1 claim is:
+
4
1st. An air-tight tank containing a sufficiency of oil to wholly submerge an a
enclosed pump-cylinder with a pump cylinder, the interior of which is connected
:

page_text: to the articles to be exhausted, and also to an air space in the tank and above the
oil, whereby the action of the pump will exhaust the air from the articles to be
exhausted and also from the tank and from the oil enclosed within the tank, said
cylinder having a port for admitting above the piston a small portion of oil for the
purpose of expelling all the air from the cylinder at each upward stroke of the
piston, a piston, the length of which exceeds the length of its stroke whereby
the port for the admission of air is open only during the lower portion of the stroke
of the piston, and a valved outlet port at the top of the cylinder, substantially as
and for the purpose set forth.
2nd. In a vacuum device, the combination of one or more vacuum pumps and an
enclosing tank, said tank being exhausted of air and containing sufficient oil to
wholly submerge the said pumps with a return box H, located at the top of said
tank, having a valved connection therewith, and adapted to receive and return to
the tank the surplus of air-expelling oil forced from the pump at each upward stroke
of the piston, substantially as and for the purpose set forth.
Dated this 19th day of May 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.