Improvements in Exhausting Apparatus, Applicable to the Manu- facture of Incandescent Lamps and for other Purposes, and in Apparatus or Means Employed therefor or therewith. AND FOR OTHER PURPOSES AND INANS EMPLOYED THEREFOR OR THERE- WI
Year: 1885

page_text: Improvements in Exhausting Apparatus, Applicable to the Manu-
facture of Incandescent Lamps and for other Purposes, and
in Apparatus or Means Employed therefor or therewith.
I MORTIMER EVANS of 97 West Regent Street Glasgow Scotland Civil Engineer
do hereby declare the nature of my invention for IMPROVEMENTS IN EXHAUSTING
APPARATUS APPLICABLE TO THE MANUFACTURE OF INCANDESCENT LAMPS AND FOR
OTHER PURPOSES AND IN APPARATUS OR MEANS EMPLOYED THEREFOR OR THERE-
WITH to be as follows:-
My Invention relates to improvements in apparatus for the production of a
vacuum for various industrial purposes among which is the construction of Incan-
descent Lamps.
In carrying my invention into practise I employ a compound vacuum pressure
or differential exhausting apparatus in which mechanical means are employed for
operating upon the chambers or apparatus (from which the exhaustion is to be
made) in communication with each other through the medium of one or more
channels of conduction.
The process of exhaustion is carried on through the medium of the abstracting
apparatus connected with such channel or channels of conduction until some
predetermined exhaustion is attained or until the potential of all parts so connected
and operating is the same These channels and vessels are so arranged as to provide
for the use of liquid or liquids in their various parts the rise and fall of which in
the various vessels and conduit indicates the difference of pressure exerted on the
liquids in the main reservoir which is adapted to be exposed to atmospheric or
other higher pressure and the pressure existing in the apparatus connected with or
worked by the other part or parts of the exhausting apparatus.
In combination with my improved exhausting apparatus suitably ground and
sealed valves are provided which may be operated either manually or automatically
by the rise and fall of the liquids employed or by a combination of both.
In combination with my improved exhausting apparatus I provide for the appli-
cation of suitable chambers provided with stoppers and valves for the introduction
of sulphuric acid either as the sole liquid to be employed or in combination with
mercury to absorb moisture from the apparatus to be exhausted.

page_text: In combination with my improved exhausting apparatus provision is made
whereby the prime exhaustion of the vessel in which a vacuum is desired is effected
by means of the main exterior apparatus which is so arranged as to act through
the channels and chambers of the secondary apparatus and independently of them
and a vacuum more or less perfect may by this main exhausting apparatus be
independently obtained. When however the action of the secondary high exhausting
apparatus is desired an alteration of the position of the sealed valve already
described (and which is connected with the various conduits and the main reservoir
of the apparatus) causes by the entrance of the air or other higher pressure a
difference of potential in the various parts of the apparatus and the vacuum
chamber in immediate connexion with the vessel to be exbausted (and through
which the main exhaustion has already taken place) now becomes filled with liquid
which rises into it, (in virtue of the difference of pressure, or potential, now
established) and at the same time this liquid expels any air or gas that it had
before contained which is drawn off as before by the main exhausting apparatus.
On the reversal of this valve equal pressure is again established when the liquid
recedes from the chamber it before filled and this chamber being now empty a fresh
charge is drawn off from the vessel to be exhausted and this by the repeated
reciprocal action of the apparatus may be effected as often as desired or until a
complete vacuum is obtained, by the reversals of the sealed valve above mentioned
either by manual, or automatic arrangement as desired.
Should any liquid follow the course of the expelled air and require removal
I provide various tubes and valves which may be necessary to effect this.
The arrangement and construction of my exhausting apparatus is such as to
reduce to a minimum or obviato entirely the admixture of air or gas or gaseous
mixture with the liquids or liquid in the main chamber or ducts of the exhausting
apparatus during the process of exhaustion and I especially provide for the use of
sulphuric acid solely or sulphuric acid in combination with mercury for exhausting
purposes and I sometimes use electrical means for automatically reversing the
sealed valve above described.

page_text: facture of Incandescent Lamps and for other Purposes, and
in Apparatus or Means Employed therefor or therewith.
I MORTIMER EVANS of 97 West Regent Street Glasgow Civil Engineer do hereby
declare the nature of my invention for IMPROVEMENTS IN EXHAUSTING APPARATUS
APPLICABLE TO THE MANUFACTURE OF INCANDESCENT LAMPS AND FOR OTHER
PURPOSES and in what manner the same is to be performed, to be particularly
described and ascertained in and by the following statement:—
My Invention relates to improvements in apparatus for the production of a
vacuum for various industrial purposes among which is the construction of Incan-
descent Lamps.
In carrying my invention into practice I employ a compound vacuum pressure
or differential exhausting apparatus in which mechanical means are employed for
operating upon the chambers (or apparatus) from which the exhaustion is to be
made in communication with each other through the medium of one or more
channels of conduction in which the secondary exhausting apparatus is arranged
as herein described.
In my improved exhausting apparatus the process of exhaustion is carried on
through the medium of the abstracting apparatus connected with such conducting
channels until perfect or some predetermined exhaustion is attained In cases
where the mechanical exhausting apparatus is insufficient to produce the vacuum
ultimately desired or otherwise when at any time it may be necessary to test the
condition of the vacuum already produced by the prime exhausting apparatus the
intermediate exhausting apparatus is brought into action and by its reciprocating
intermittent motion a large highly exhausted chamber in which a pure vacuum
exists is alternately placed in communication with the vessel to be exhausted and
afterwards shut off therefrom at the same time any air or gas abstracted from the
vessel to be exhausted is (by the rising and shutting off by the liquid in the
chamber already referred to) expelled into the adjacent channel, whence it is with-
drawn by the main exhausting apparatus by which the prime exhaustion had
already been performed as described.
In order that my invention may be the better understood I here give a descrip-
tion of the same as shewn in the accompanying drawings.
Figure 1 is a vertical section of an apparatus to which my invention would
apply. A is the main conducting channel by means of which the air or gas is
withdrawn from the apparatus and which communicates with an exterior pump
or air exhausting apparatus not shewn and by means of which a more or less
perfect vacuum is maintained in all the channels and tubes permanently or
periodically connected with it.
o is a vessel or chamber to be exhausted which by means of the necessary air
tight fittings and the pipe p is placed in communication with the interior of the

page_text: bulb or high exhaustion chamber b This vessel b is so fitted by means of the
tube b¹ as to be in permanent communication with the liquid contents of the reser-
voir B. (into which it is fitted with an air tight stopper) and into which liquid the
tube descends so far that no change of level in the liquid in B will allow its lower
orifice in any case to be exposed.
At its upper end this vessel is contracted in size until it forms a duct or tube
which being bent over passes downwards to such convenient distance that if filled
with liquid it will under all conditions effectually balance any difference of pressure
which may occur between the interior of the chamber b and the outlet or duct A
or its branches to the main exhausting apparatus.
a is a
At 6 this tube or duct is again bent upwards and is continued into the duct a
and by means of it communicates with the main exhausting channel A,
branch duct from the main exhausting channel A leading through the stopcock or
valve d to the interior of the reservoir B through which exhaustion into the main
channel A may take place.
d is a valve of stopcock having two openings as shewn in the enlarged drawing
Fig. 2 its action is twofold in the one position (as shewn in the drawing) it provides
for a through communication between the main exhausting channel A and the
reservoir B. So that any air or gas in the reservoir B may be readily drawn off
through it into the duct or channel A, in its reversed position it cuts off this and
all communication between the reservoir B and the channel A to the main
exhausting apparatus and allows instead the entrance of air, gas, or other con-
venient liquid through the aperture d' into the chamber or reservoir B.
The reservoir B. at the base of the apparatus is provided to contain the liquids
necessary to ensure the correct action of the other portions of the apparatus and
when out of action or in communication through the valve d with the channel or
duct A and at rest, it is nearly or quite filled with the liquid or liquids by means
of which the final exhaustion is carried on.
g is a bent tube communicating between the the bulb c and the upper portion of
the reservoir B. to each of which it has an air tight connexion. And its length
should be such that the liquid or liquids it may contain will in all circumstances
counterpoise any difference of pressure that may occur between the reservoir B.
and the main exhausting channel A. the object of this tube, if used, is automatically
to return any superfluous liquid that may have passed over in expelling the air
from the chamber b. This tube I sometimes dispense with altogether and substitute
in lieu thereof a smaller tube having a connexion directly across between the bulb c
and the valve or stopper d. as shewn in drawing Fig. 3 this tube should be of
small diameter and when it is used the valve d should be made as large as it
conveniently can be.
h. h¹ are vessels communicating with the chamber b or its connexions by means
of the tube or duct leading thereto from the vessel to be exhausted o the vessel h
is occasionally filled with any desirable liquid (usually strong sulphuric acid) that
it may be desirable to pass into the chamber b h¹ is an intermediate chamber and
are two stoppered air tight valves similar to the valve d but with a single
opening.
i.
On opening the valve i the liquid contained in h. passes into the chamber h¹
when this valve i. is then closed. On opening the valve the contents of the
chamber h¹ find their way into the chamber b and its connexions as desired.
When I do not use the tube g or the arrangement shewn in Fig. 3 I sometimes
substitute a sealed valve or stopper of the same character as the valve d. which
I affix to the lower part of the bulb c. By its means and an auxilliary vessel
provided with a valve or cock at its lower end Fig. 4 I draw off at any convenient
period any superfluous liquid that may have passed over from the chamber b.
during the secondary exhausting process This liquid may then be returned if
desired to the chamber b by means of the before described apparatus shewn at h. h¹.
f is a valve connected with the reservoir B. by which liquid from this reservoir
may occasionally be drawn off if desired.

page_text: That the action of my apparatus may be the understood I proceed to describe it
as follows.
The apparatus being constructed as shewn in Fig. I the contained air or gas is
withdrawn, by the exterior pumping apparatus acting through A.
By these means air is exhausted in detail from the channel or duct a the valve d
and the upper portion of the reservoir B. And simultaneously with this, exhaustion
takes place through the duct a¹ & the duct 611 of the vacuum chamber of the
intermediate apparatus b. and through it and its connexions of the vessel o and
these all are simultaneously freed either entirely of air or to such extent as the
exterior exhausting apparatus is capable.
Should this vacuum prove a sufficient one farther action of the main pumping
apparatus (which is supposed to be constant) will in the same way and through
the same channels remove any occluded gas which may subsequently form or be
given off at the vessel o by heating or otherwise. Should however it be desirable
to put in action my secondary, or interposed high exhaustion apparatus either
to test the exhaustion or to carry the exhaustion farther than the exterior
apparatus is capable the valve d is for this purpose put into action, and by being
reversed i.e. turned half way round air or gas is allowed to enter by the opening d¹
into the upper part of the main vessel or reservoir B.
All communication between the reservoir B. and the main exhausting channel A
now ceases by the reversal of this valve and communication with it exists solely
through the medium of the vacuum chamber b. the channel 611 and the extension
the channel a¹.
The difference of pressure now established between the air or gas in the reser-
voir B. and the main exhaust duct A. compels the liquid or liquids in the reservoir B.
to rise into the vacuum chamber b and thence passing upwards to force out all air
or occluded gas which may have collected in its interior through the channels 611
and a¹ out into the main exhaust duct A As soon as this is accomplished the
valve & may be again reversed and caused to occupy the position shewn in the
drawing as first described.
The air or gas in the reservoir B. will now pass upward through valve d and be
removed through the main duct A and the liquid in the chamber b will accordingly
fall creating a complete vacuum throughout its whole interior. On its receding
below the orifice of its enclosed tube any air or occluded gas from the vessel o will
now pass into it when the above process may be repeated as desired.
When I desire to work my interposed high exhausting apparatus automatically
I sometimes provide an electrical or electromagnetical arrangement whereby the
valve d may be reversed periodically as the liquids in the various vessels or
ducts reach certain convenient predetermined points and I sometimes provide
a tube and float e in connexion with the reservoir B. as shewn in Fig. 5 provided
with a cock or valve K, (to provide against too violent or pumping action the
rising and falling of which float is arranged through the medium of the usual
tumbler device in which a weight hinged below its centre of gravity is caused to
tumble from side to side as the float rises or falls and in so tumbling turns or
reverses and actuats the valve as desired.
In combination with my improved exhausting apparatus as herein described
I provide for the use of sulphuric acid solely or sulphuric acid in combination with
mercury for exhausting purposes and the arrangement of my exhausting apparatus
is such as to reduce to a minimum or obviate entirely the admixture of air or gas
or gaseous mixtures with the liquid or liquids in the main chambers or ducts of the
exhausting apparatus during the process of exhaustion of the chambers as described.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I hereby declare that
what I claim is
1st The employment of a secondary high exhausting apparatus interposed in the
channels of conduction between a mechanical exhausting apparatus and the vessels

page_text: or chambers to be exhausted in which sulphuric acid alone or the same in combi-
nation with mercury is employed.
2nd In exhausting apparatus such as is described in the preceding claim the
employment of means for manually controlling the operation of the secondary
exhausting apparatus.
3rd In exhausting apparatus the employment of means for automatically operating
the secondary apparatus with or without the employment of manual means as set
forth in the claim immediately preceeding.
4th In exhausting apparatus the employment of means or combinations of parts
adapted to operate substantially as set forth in the respective paragraphs.
Dated this fifth day of February 1886
MORTIMER EVANS.