Improvements in and relating to Vacuum Pumps.
Year: 1891

page_text: Date of Application, 24th Feb., 1891--Accepted, 30th May, 1891
OUBLE LININ SIMULETATION.
[Communicated from abroad by ADOLPH BERRENBERG, of Somerville, County of
Middlesex, Massachusetts, United States of America, Engineer, and WILLIAM
EMERY NICKERSON, of No. 111, North Avenue, Cambridge, Middlesex,
Massachusetts, United States of America, Chemist.]
Improvements in and relating to Vacuum Pumps.
1, 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 consists in using as a sealing medium for the jacketing spaces
about a vacuum pump cylinder and its connections a liquid deprived of air or other
gascous or volatile bodies.
This invention may be put in practice by a great variety of devices, one of which
is shown in the accompanying drawings, in which the parts are shown partly in
section and partly in elevation, the illustration being intended to be as far
diagrammetrical as is consistent with a clear understanding of the method.
In the illustration, A. represents, the inner cylinder of a vacuum pump A the
jacketing cylinder. The space S between the two cylinders is closed at all points
so that no air can enter it. B represents the bottom of the cylinder proper, and
B' the bottom of the jacketing cylinder.
The valves used in this illustration consist of a valve D, serving to admit air
from the chamber being exhausted; and of a valve E, through which the air is to
be expelled. The above described valves are not operated by the pressure of the
air, but should be provided with mechanism which will cause them to act indepen-
dently of the air, and at such times as the best action of the pump requires.
I will now describe an oil supply device. M is a reservoir for oil located above
the spaces in and about the pump so that the oil will flow by its gravity, unless
checked, from the reservoir, to the spaces to be sealed. This reservoir M is con-
nected by the pipe K to a force-pump K', and through the force-pump by the
pipe K to the jacketing space or spaces S, S', S, of the vacuum pump. The
circulation of the oil being completed through the pipe L, weighted valve L' and
pipe L2
In the illustration an auxiliary air pump M is shown immediately over the oil
reservoir M; the cylinder of this pump M¹ has a valve as shown at M², and a
piston N, also provided with a valve.
The mode of operation involved in this illustrative device is as follows:
The oil or other fluid to be used is placed in the reservoir M, thence made to fill
the circulation pipes and spaces S, S1, S2, of the vacuum pump to be sealed.
Now if we start the apparatus, the oil in the reservoir M, will be subjected to a
vacuum and its embodied air will expand and rapidly leave it in a deaerated con-
dition, as the movements go on all of the oil in the circulation pipe and in the
sealing parts will become deaerated to such a degree that no more air can be drawn
from the oil, and thus the oil becomes a medium properly adapted for the purpose
of sealing.
If the oil in its circulation becomes, from any cause re-aerated, as it readily
absorbs air when brought in contact with it, it is again restored to its airless
condition by the continued action of the vacuum in reservoir M.
This invention does not depend upon the mechanism by which it is put in
practice, but upon the use of deaerated oil for a sealing medium, thereby making
a vacuum pump more efficient than has heretofore been done.

page_text: It is well known that satisfactory vacuums have been produced by means of
mercury pumps, but they are extremely and necessarily slow.
The method above described admits of using large pumps, the functional parts of
which may move rapidly, so that it becomes possible to exhaust on a large scale;
for example, if the pump is applied to the work of exhausting electric incandescent
lamps, hundreds may be exhausted at one operation and in a very short time.
In the above description and accompanying drawings, parts not claimed in this
application, are described and shown in an application (of even date, serial
number 351,359), filed by us in the United States Patent Office.
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
First. In the jacketing spaces of a vacuum pump deaerated oil as a sealing
medium, substantially as and for the purpose set forth.
Second. In a vacuum pump the combination of jacketing spaces sealed with
deaerated oil, and an apparatus having passage connection with said spaces and
adapted to deaerate the oil and force it through the jacketing spaces, operating
substantially as and for the purpose set forth.
Dated this 24th day of February 1891.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, Agents for the Applicant.