Improvements in and connected with Vacuum Pumps.
Year: 1891

page_text: Date of Application, 24th Feb., 1891-Accepted, 28th Mar., 1891
COMPLETE SPECIFICATION.
Improvements in and connected with Vacuum Pumps.
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of this invention (a communication to me
from abroad by Adolph Bornholdt, Engineer, of 350, Drigg Street, and Joseph
Glatz, Chemist, of 165, New York Avenue, both in Brooklyn, County of Kings
and State of New York, United States of America), 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 a vacuum pump and condenser combined, serving to
draw vapors from any suitable source into a vacuum which is created by the pump,
to condense these vapors, and to mingle the products of condensation with water
from which the same may afterwards be conveniently removed; and the invention
consists more particularly in the employment within each pump chamber of a
reciprocating piston combined with a valve mechanism for closing the passage to
the vapor chambers whenever the piston approaches said passage, and for opening
the same whenever the piston recedes therefrom, and with valve mechanism also for
throwing the products of condensation into a column of water which always follows
one side of the piston, as hereinafter more fully described.
Reference is to be had to the accompanying drawings, forming part of this
Specification, in which
Figure 1 is a vertical central section of the improved vacuum pump and
Figure 2 is a top view, partly in section, of the same.
In the drawings two vacuum pumps of the improved construction are represented,
both being joined to the vapor supply pipe A. by branch pipes B B, but it is to be
understood that the invention is not limited to the conjoint use of two pump cylinders
of the new construction as one alone may, in many instances, be profitably employed
or more than two in connection. But one of these cylinders will, therefore, be
described.
The
The vacuum pump cylinder is shewn at C and contains a piston D whose stem E
extends into a steam cylinder F within which it carries a piston or plunger G.
Steam is supplied to the cylinder F, on opposite sides of the plunger G alternately,
in the well-known manner, the devices for introducing it not being represented in
the drawings. The effect of the alternate admission of steam to the upper and
lower part of the steam cylinder F is to lower and then raise the plunger G and
thereby to lower and to raise the plunger D within the vacuum pump.
plunger D is perforated and with it the stem E is likewise perforated for the
purpose of admitting within the tubular cavity thus formed a stem H of a valve [
which valve is placed below the entrance of the vapor supply pipe B to the
cylinder C. A spring J may be placed above the valve I, as shewn, but in lieu of
this spring an equivalent weight may be employed. The stem H where it enters
the tubular passage of the plunger D is embraced frictionally by a washer a which
has for its object to normally retain the valve I in the position which corresponds
to the motion of the plunger D, that is when the plunger D moves upwards this
frictional grasp will cause the valve I to move upwards too until it finds resistance
on its seat, thus closing all communication with the pipe B, whereas, when the
plunger D moves downwards, this frictional contact with the stem H will cause it
to draw the valve I away from its seat and thereby establish communication
between the vapor pipe B and the cylinder C. The plunger D carries also a check
valve which opens downwardly and which closes upwardly, under the influence of
a suitable spring or otherwise, against its seat. By preference, this check valve b
is contained within an upward extension d of the plunger D, as shewn, and, in case

page_text: this upward extension is employed, the upper head of the cylinder C has a corre-
sponding upwardly extending chamber. e into which the extension d can enter, as on
the right-hand side of Figure 1, when the plunger D is raised. Below the
lowermost position of the plunger D is a water supply passage f in the wall of the
cylinder C which communicates with a water reservoir L. It is preferred to place
this water reservoir alongside each pump cylinder, as clearly appears from
Figures 1 and 2 of the drawings, but it may be placed at a distance therefrom
whenever desired and by water reservoir is meant either water or any analogous
liquid which will answer the purpose of receiving the products of condensation and
of cooling the walls of the vacuum cylinder; another object of the water being to
make air tight connections wherever its column contacts the movable parts of the
machine. Directly above the lowermost position of the plunger D is a jet supply
pipe M through which a jet of water or analogous liquid may be sprayed into the
cylinder C when the plunger D is down.
Having now described the construction of the new pump, I will proceed to
describe its operation. Supposing the plunger D of the vacuum pump to be in the
lowermost position, shewn on the left hand side of Figure 1. In this position the
valve I is open and vapors are free to enter from the pipes A B into the vacuum
cylinder C, the valve is closed so that these vapors cannot escape from the
cylinder C and the aperture m being open to admit a small spray or stream of
liquid into the cylinder C sufficient simply to cover the plunger D and prevent
leakage of air from around the same which it continues to do during the subsequent
ascent of the plunger D. Steam is now admitted beneath the piston G and the
plunger D thereby lifted. As soon as it begins to lift it causes the valve I to be
closed and is now dealing with the confined column of vapors which had previously
been admitted to the cylinder C. This column of vapors the plunger D, as it
continues to rise, compresses, no escape for the same being provided for until the
compression has reached such a degree that, under its influence, the check valve b
is opened, when, during the continued ascent of the plunger D, these vapors will be
forced into the column of water beneath the plunger D until finally the plunger D
is in the most elevated position, shewn on the right hand side of Figure 1, when
there will be no more vapors or practically none left above the plunger D all
having been discharged into the water which during the ascent of the plunger D
was caused to follow it from the reservoir L through the aperture m. Having now
attained the most elevated position, the plunger D is next moved downwards by
causing steam to be admitted to the upper part of the steam cylinder F. As soon
as the downward motion is started, the valve I is immediately opened and fresh
vapors are admitted into the vacuum chamber which otherwise would be created by
the descent of the plunger and the descent of the plunger further serves to force the
water beneath the aperture back into the reservoir L and thence out through a
suitable conduit until finally the lowermost position of the plunger D, shewn on
the left hand side of Figure 1, has been again attained. The products of
condensation can be separated from the liquid that is discharged from the
reservoir L or directly within the reservoir L if desired, by any well known means,
according to the character of these products in each instance.
Having now particularly described and ascertained the nature of the said
invention, and in what manner the same is to be performed, I declare that what
1 claim is
1. The vacuum cylinder C having outwardly closing valve I and valve stem H
combined with the plunger D having outwardly closing valve said plunger being
frictionally connected with the stem H of the valve 1, substantially as described.
2. The vacuum cylinder C having outwardly closing valve I and reciprocating
plunger D which is frictionally connected with the said valve, said plunger having
outwardly-closing valve in combination with the water reservoir and with the
water supply passage in the wall of the cylinder near that end thereof which is
opposite to the end receiving the valve I, as specified.

page_text: 3. The vacuum cylinder C having outwardly closing valve I and reciprocating
plunger D which is frictionally connected with said valve, said plunger having
outwardly-closing valve bin combination with the water reservoir L with the
water supply passage fin the wall of the cylinder near that end thereof which is
5 opposite to the end receiving the valve I and with the spray supply pipe M located
above the plunger D, as described.
Dated this 94th dow of February 1801
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.
A. MELVILLE CLARK.
By A. M. & Wm. Clark,
53, Chancery Lane, London, Patent Agents.