An Improvement in Vacuum Pumps.
Year: 1889

page_text: Date of Application, 24th May, 1889
Complete Specification Left, 15th Feb., 1890-Accepted, 22nd Mar., 1890
PROVISIONAL SPECIFICATION.
An Improvement in Vacuum Pumps.
I, EDWARD FRANCOIS VARALDI commonly known as Franck Varaldi of 23 Boulevard
de Strasbourg, Paris, France, do hereby declare the nature of this invention to be
as follows:-
.
My invention relates to a simple construction of vacuum pump, especially applicable
for exhausting bulbs of incandescent electric lamps. On a horizontal axis, which is
formed with ports like the plug of a stopcock, I mount two tubular arms more than.
30 inches long, to the outer ends of which are jointed vessels. having their tops con-
nected by a rod jointed to them.
This rod is mounted on an axis above that on which the arms are mounted so that
it is always parallel to the arms, when they are caused to oscillate on their axis, and
the vessels at the ends of the arms are thus always maintained in a vertical attitude.
The vessels are charged with mercury, and the ports in the plug axis communicate
with a vacuum tube to which are attached the bulbs or other vessels to be exhausted.
When the tubular arms are caused to oscillate on the plug axis, the mercury flows
down the one arm away from the axis, creating a vacuum and a port being then open
to the vacuum tube, air is drawn into that arm from the vacuum tube. The mercury
in the other arm flows down towards the axis, and the port to the vacuum tube being
then closed, such air as had been previously drawn into that arm has to find its way
through the mercury to the vessel at the end, and to escape at the top of the vessel
which is open. Thus, by oscillating the arms and so displacing the mercury in them
through a height exceeding 30 inches at each oscillation, there is formed in each arm
alternately a Torricellian vacuum next the axis, into which air is drawn from the
vacuum tube, and from, each, arm alternately the air drawn in is expelled. It is
preferred to enlarge the cavity of each arm near the axis so as to have the vacuum
formed in a considerable space.
Dated this 24th day of May 1889
.
ABEL & IMRAY,
Agents for the Applicant.
COMPLETE SPECIFICATION.
An Improvement in Vacuum Pumps.
I, EDWARD FRANCOIS VARALDI commonly known as Franck Varaldi of 23 Boulevard
de Strasbourg, Paris, France, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:-
My invention relates to a simple construction of vacuum pump, especially applicable
for exhausting bulbs of incandescent electric lamps. Fig. 1 of the accompanying
drawings is a side view of a vacuum pump according to this invention. Figs. 2, 3
and 4 drawn to an enlarged scale shew the axis and its parts Figs. 2 and 3 being
sections respectively on A B and C D of Fig. 4 which is a sectional plan. On a hori-
zontal axis B which is formed with parts e e' like the plug of a stopcock, I mount
two tubular arms A A¹ more than 30 inches long, to the outer ends of which_are
jointed vessels D D' having their tops connected by a rod T jointed to them. This
rod T is mounted on an axis above that on which the arins A A¹ are mounted so that
it is always parallel to the arms, when they are caused to oscillate on their axis, and
the vessels D D at the ends of the arms are thus always maintained in a vertical
attitude. The vessels are charged with mercury, and the ports e e¹ in the plug axis B
[Price 6d1

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communicate by a passage and canal 9 with a vacuum tube C to which are attached
the bulbs or other vessels to be exhausted. i is a cock by which the apparatus can be
put in communication with the outer air. When the tubular arms are caused to
oscillate on the axis B, the mercury flows down the one arm, away from the axis,
creating a vacuum and one of the ports e e¹ being then open by one of the passages ff1
to the descending arm, air is drawn into that arm from the vacuum tube C. The
mercury in the other arm flows down towards the axis, and the port to the vacuum
tube being then closed, such air as had been previously drawn into that arm has to
find its way through the mercury to the vessel at the end, and to escape at the top of
the vessel which is open. Thus by oscillating the arms and so displacing the mercury
in them through a height exceeding 30 inches at each oscillation, there is formed in
each arm alternately a Torricellian vacuum next the axis, into which air is drawn
from the vacuum tube; and from each arm alternately the air drawn in is expelled.
It is preferred to enlarge at a a¹ the cavity of each arm A A¹ near the axis so as to
have the vacuum formed in a considerable space.
The oscillation of the arms A A' may be effected by a reciprocating link E connected
to a crank, eccentric or hand lever. The state of the vacuum in C may be ascertained by
observing the height of mercury in a tube 6 leading from C to a mercury cup, and
comparing that height with the height in a barometer tube c.
.
Having now particularly described and ascertained the nature of this inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
A vacuum pump constructed and operating, substantially as herein described and
illustrated by the drawings.
Dated this 14th day of February 1890.
ABEL & IMRAY,
Agents for the Applicant.