Improvements in and relating to Vacuum Pumps.
Year: 1891

page_text: Date of Application, 24th Feb., 1891-Accepted, 28th Mar., 1891
COMPLETE SPECIFICATION.
Communicated from abroad by ADOLPH BERRENBERG, of Somerville, County of
Middlesex, Massachusetts, 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 consists in forcing at each upward stroke of the piston, a quantity
of oil from which the air has been drawn into the cylinder, said oil to serve to fill
all of the unoccupied space under and about the piston when it is at its lowest
point, thus expelling all air; during the downward stroke of the piston all
excess of oil is forced out of the cylinder into a vacuum tank, in which tank the
air that has been taken up by the oil during the descent of the piston will be with-
drawn, and the oil will be ready to be again forced (in its de-aërated condition)
back into the cylinder from which its excess is again expelled, and returned to the
de-aërating tank, this circulation and de-aëration taking place at each stroke of
the piston.
An apparatus for putting this invention in practice is shown in the accompanying
drawing, which is partly in section and partly in elevation.
Let S represent the cylinder of an air pump, and N the piston; one head S¹ only,
of the air pump is shown, this head S₁ has three valves, namely:-a valve T, for
the admission of de-aërated oil, a valve R, in the air pipe R' which serves to draw
air from the article to be exhausted, and the valve P which furnishes an outlet for
the excess of oil, and also for the discharge of air drawn from the articles being
exhausted.
All of the above valves have mechanical connections by means of which they are
to be operated independently of any pressure of air or oil.
The oil circulating and de-aërating device chosen for illustration may be
described as follows:
C is an oil tank having a valve C₁ for the outlet of air that is drawn from the
oil in the process of de-aëration.. E is an air pump having a piston E' in which a
valve is placed.
Oil from the tank C, flows to the force pump A, through the pipe B, and is
forced through the pipes A', A2, to the valve T, and thence into the cylinder S,
under the piston N.
To maintain and also to limit the pressure of the oil in the pipes A1, A2, and the
chamber of the valve T, a weighted valve is placed at D' and connected to the
pipe A by the pipe D, and to the tank C by the pipe D¹.
The excess of the oil (that passes into the space at the lower end of the cylinder
for the purpose of occupying all of the space that is left between the piston and
the cylinder at the completion of the downward stroke) is forced out through the
valve and with the air passes through the pipe P¹ to the return box P². The
box P2 has in it a valve P attached to the float P³. The float P³ is so large in
comparison with the valve P that its displacement of oil is sufficient to lift the
valve off its seat whenever the oil accumulates in the box P to a sufficient height.
When the valve P is lifted as above, the accumulated oil in the box P will pass
through the pipe H to the oil tank C.
The top of the box P² is open so that the air from the pump can freely
pass out.

page_text: 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 correspondents, 1 declare that what I claim is:
•
:-
The combination in a vacuum pump of a piston and cylinder: "witli'a filling of
de-aerated oil adapted to fill all the space under and about the piston within the
cylinder at the completion of the stroke of the piston, and thus completely expel
all air, 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.