Improvements in Vacuum Pumps.
Year: 1891

page_text: Date of Application, 8th June, 1891-Accepted, 11th July, 1891
COMPLETE SPECIFICATION.
[Communicated from abroad by WILLIAM EMERY NICKERSON, of 111, North
Avenue, Cambridge, Middlesex, Massachusetts, United States of America,
Chemist.]
Improvements in 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 :-
The object of this invention is to adapt a diaphragm pump to the work of
exhausting air.
This object I attain by the mechanism shown in the accompanying drawings, in
which
Figure 1 is a side elevation of my device.
Figure 2 is a vertical section of the same.
The device selected for illustration consists of two circular diaphragms B and B',
united air tight at their edges. The diaphragm B is riveted or otherwise attached
to the centre piece C, and this centre piece C is firmly secured or made integral
with the flange piece D, as shown: the flange piece D is secured by screws E, E,
to one side A of the outside casing.
L is a valve located in the centre of the diaphragm B. This valve L has a
stem L' forked as shown and so fitted to the hole in the rod M that it shall
have a strong frictional connection with the said rod so that the said valve L will
move with the movements of the rod M, unless it is held by its seat from moving
in the closing direction, or by the nut L³ on the stem I, after opening to the
desired extent. Although the valve is actuated, that is closed and opened by the
movement of the rod M, its motion is very slight in comparison to that of the rod,
and it opens with the beginning of the outward movement of the rod, remaining
open during the full outward stroke and closes promptly at the beginning of the
inward movement and remaining closed during the entire inward movement.
Small openings V, V are made in the diaphragms for the outlet of air and oil
while the pump is closing, and for the admission of small quantities of oil when the
diaphragms are opening. These small openings, when intended for the admission
and emission of oil only may be located at any part of the diaphragm when the
whole is immersed in the oil; but when the openings are intended for the emission
of air either with or without the oil, they must of necessity be made at or near the
highest part of the diaphragms, as the air being lighter than the oil, naturally seeks
the top.
The action of my pump is as follows:-
The rod M being actuated by any suitable mechanism moves the diaphragm to
and from each other. As they move towards each other the contained air and oil
are forced out of the openings V, V, the air passing up through the oil in the
space S, escapes through the pipe T', and the oil mingles with the oil in the
space S.
Now as the diaphragms begin to separate, opening the valve L, air from the
vacuum pipe F will enter and at the same time a small quantity of oil will flow in
through the openings V, V and settle to the lowest part of the space between the
diaphragms.
As the oil is heavier than the air, it is evident that as the diaphragms close, air
will pass out first and then oil follows, so that when the diaphragms are closed the
small spaces left between them will be filled with oil, all of the air, having been

page_text: expelled. When the chamber outside of the diaphragms, and inside of the case
formed by the parts A, A', is not filled with oil but is a partial vacuum, then the
openings V, V must be provided with outwardly opening valves, and as oil, or some
similar fluid is used for filling the space that is left between the diaphragms when
collapsed it may be introduced through the pipe F and, after having been forced
out from between the diaphragms through the openings V, V into the chamber S,
may be drawn off through the pipe H.
it
F is a vacuum pipe leading from the articles to be exhausted to the pump; this
pipe F has a jacketing space S' around it, formed by the jacket pipe H, the
jacketing space S¹ being connected to the chamber S by the pipe H. The pipe H2
serves to connect the lower part of the chamber S with the jacket pipe H at the
extreme end of the vacuum system of pipes F, so that there may be a circulation of
jacketing fluid throngh the chamber S and the pipe H2, H, H.
Krepresents a strong disk attached to the rod M, and also to the diaphragm B¹.
In the action of the pump this disk serves to force the diaphragm B flat onto the
diaphragm B, thus forcing out all air and nearly all the oil from between them.
K is a central piece attached directly to the main body of the disk K, and to the
rod M, as shown. This construction admits of taking out the valve L, when
desired. A represents a stuffing box for the rod M. If desirable an oil pocket A³
for checking the inward leakage of air may be attached to the case A, as shown;
this pocket makes it necessary to have an additional stuffing-box A for the
rod M.
An outlet pipe T¹ is connected to the case A, A¹, by means of a screw
thimble T.
The parts A and A' that form the case are bolted together, as shown at R, R.
A convenient base A5 may be cast solid with the parts A, A.
It is obvious that instead of two diaphragms, one alone could be used in
connection with a co-ordinate part which may be made, either of rubber or of
metal, if of metal it may have circular corrugations, in which case the part against
which the single metal diaphragm closes should have corrugations to correspond
with those of the diaphragm.
This form of pump will work much easier and better if an exhaust device is
attached to the pipe T', so that the external pressure on the diaphragms shall be
greatly reduced or almost entirely removed.
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 I claim is
1st. In a vacuum pump, the combination of the diaphragins (B, B') having a
to-and-fro motion in relation to each other, the pipe (F) connecting the space
between the said diaphragms to the articles to be exhausted, the valve (L) in
connection with the pipe F and openings (V V) as described; with a sealing
liquid, a small quantity of which is introduced into the space between the
diaphragms at each of their successive separations, thereby serving to completely
expel all air at each successive closing of the same, substantially as and for the
purpose set forth.
2nd. In a vacuum pump, the combination of diaphragms (B B¹) having to-and-fro
inotion in relation to cach other, the pipe (F) connecting the space between the
said diaphragms to the articles to be exhausted, the valve (L) in connection with
the pipe (F), and openings (VV): with a case (A A) filled with a suitable liquid
as described, enclosing said diaphragms, and pipe (T') connecting it to an auxiliary
exhaust device, substantially as and for the purpose set forth.
Dated this 8th day of June 1891
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.