IMPROVEMENTS IN MERCURIAL AIR PUMPS
Year: 1882

page_text: LETTERS PATENT to David Johnson of Barrelwell House in the City and
County of Chester Gentleman and Samuel Charles Tisley of No. 172 Brompton
Road in the County of Middlesex Optician, for an invention of " IMPROVE-
PROVISIONAL SPECIFICATION left by the said David Johnson and Samuel
Charles Tisley at the Office of the Commissioners of Patents on the
5th May 1882.
DAVID JOHNSON of Barrelwell House in the City and County of Chester
Gentleman and SAMUEL CHARLES TISLEY of No 172 Brompton Road in the
County of Middlesex Optician "IMPROVEMENTS IN MERCURIAL AIR PUMPS."
Our Invention consists first of the improvements hereinafter described in the
apparatus known as Spreingle's pump by which improvements the quantity of
mercury and the power required for producing a given result with the said
apparatus are reduced a better vacuum is produced and the said apparatus is
rendered capable of being worked more rapidly than the ordinary apparatus and
by means of any suitable motor.
According to this part of our invention we mount a number of tubes vertically
in brackets affixed to a suitable standard. The upper ends of the said tubes
(which correspond with the "dropping tubes" in Spreingle's pump) are all at the
same level and open into a sealed chamber the upper part of which is provided
with a tube to which the article or articles to be exhausted is or are connected.
The lower ends of the dopping tubes aforesaid open into a chamber into which
the mercury from them passes which chamber communicates by means of a syphon
tube with a force pump which also communicates with the interior of the upper
chamber by means of a tube the top of which is enlarged and is at a lower level
than the tops of the dropping tubes. This tube and the syphon tube are provided
with valves arranged so that when the pump is worked the mercury passes from
the lower chamber to the pump and from the pump to the upper chamber but is

page_text: prevented from passing in the reverse direction through the said tubes. We prefer
to form a bulb or enlargement in some suitable part of the tube communicating
between the pump and the upper chamber which bulb constitutes an air chamber
the elasticity of the air in which absorbs the shocks caused by the intermittent
flow of mercury from the pump. The tube at the upper part of the upper chamber
is provided with a stop cock by closing which before removing the article or
articles which has or have been exhausted the vacuum or partial vacuum in the
said chamber is preserved. The said tube is or may be also provided with branch
tubes having stop cocks by means of which any required gases may be admitted
to the article or articles being exhausted
The apparatus is provided with an ordinary mercurial barometer for showing
the pressure of the atmosphere and beside it a glass tube open at top and bottom
is set vertically the upper end being within the aforesaid upper chamber and
above the level of the tops of the dropping tubes and the lower end dipping into
the mercury cistern of the said barometer. This tube corresponds with the
'comparative tube" of an ordinary "Spreingles" pump and by comparing the
height of the mercury in it with the height of that in the said barometer
the extent of rarefication of the air in the upper chamber may be ascertained.
**
The valves which we prefer for preventing the return of the mercury in the
tubes connected with the pump consist of pieces of india rubber tubing compressed
at one end while the rubber is warm or in a plastic state. The pieces of tubing
are thus permanently flattened at one end and though (owing to the elasticity of
the rubber) they are capable of being opened by pressure from within they cannot
be opened by pressure from withont. Pieces of tubing thus compressed when
secured in or over the ends of the tubes conveying the mercury allow it to pass
freely in one direction but prevent it from passing in the reverse direction.
An ordinary forcing pump or any other suitable apparatus may be used for
One form of such
forcing the mercury from the lower to the upper chamber.
apparatus consists of a tube of india rubber around which a strip of flexible non
elastic fabric is wrapped the marginal parts of which strip of fabric are then
secured together and form a flange by which the said tube is secured in the form
of a circle to the surface of a flat board or plate on which and in the centre of the
circle a rotatory shaft is mounted in suitable bearings the said shaft having affixed
to it radial arms which carry rollers which bear on the said tube and compress it
at the parts where they bear. By connecting the ends of this tube one to the
outer limb of the syphon tube of the apparatus herein before described and the
other to the lower end of the tube herein before described as passing from
the pump to the upper chamber and by giving rotatory motion to the aforesaid
shaft in the required direction the mercury entering the india rubber tube from
the syphon tube is pressed through the said india rubber tube and forced into the
upper chamber.
Valves are not required with this apparatus the pressing rollers
preventing the return of the mercury.
Or the apparatus herein after described may be used.
The ends of the tubes by which the mercury is conveyed from the lower
chamber and to the upper chamber may be connected to a bag formed of a suitable
flexible material and attached to a cylinder or chamber against which bag a piston
or plunger works the working of which piston or plunger compresses the bag and
allows it to expand alternately thus drawing and forcing the mercury as required.
In this arrangement the tubes require to be provided with valves for preventing
the return of the mercury.
The pump or apparatus for forcing the mercury through the tubes may be
worked either by hand or by means of any suitable motor.
Although we prefer to provide our improved apparatus with a number of
dropping tubes as herein before described one only may be employed.
The improvements herein before described may be applied to Spreingle pumps
of the ordinary construction.
Our Invention consists further of improvements in the apparatus originally

page_text: known as the " © Geissler" air pump which apparatus as ordinarily constructed
consists of a chamber (termed the " exhausting chamber") to the upper and
lower parts of which tubes are connected that from the upper part dipping into an
open vessel containing mercury (termed the "outlet chamber") and set at a lower
level than the exhausting chamber and that from the lower part communicating
at its extremity by means of a flexible tube with a vessel containing mercury
(termed the "lifting bulb") and at a point a little below the exhausting chamber
with a syphon tube (termed the "connecting tube") to the free end of which the
article to be exhausted is connected. By alternately raising and lowering the
lifting bulb the air in the said article and in the tube and exhausting chamber is
driven out through the mercury in the outlet chamber.
Our improvements in the said apparatus consist in substituting a flexible bag
containing mercury for the lifting bulb which bag we enclose in a chamber to
which gas steam compressed air or water under pressure may be admitted by
means of a pipe provided with a stop cock and from which the said gas steam
compressed air or water may be allowed to escape by means of another pipe
provided with a stop cock which stop cocks are worked automatically by means of
the following arrangement. Above the outlet chamber a lever is mounted to
which are connected two rods one of which is also connected to the said stopcocks
the other which descends into the outlet vessel carrying two blocks of iron one
above the other the upper one being secured to the said rod and the lower one
being free to slide upon it its upward motion being limited by the fixed block and
its downward motion being limited by a stop on the said rod. The action of this
apparatus is as follows:-The inlet pipe of the chamber containing the bag of
mercury being connected to a reservoir of gas steam compressed air or water under
pressure the gas steam air or water therefrom enters the said chamber and com-
presses the bag containing the mercury which is thereby forced up into the
exhausting chamber and from the upper tube connected therewith into the outlet
chamber the rising of the mercury in which chamber causes the lower block of iron
to rise on the rod connected to the lever until the said block meets the upper block
when the said rod and lever are raised and the stopcocks are thereby turned so as
to shut off communication between the reservoir of gas steam air or water and to
open the escape pipe. The pressure being thus removed the mercury in the
exhausting chamber returns to the bag and part of that in the outlet chamber
rises in the tube connecting it with the exhausting chamber. The rod and lever
being thus allowed to descend the stop cocks are again turned the escape pipe
being thereby closed and the supply pipe opened when the action herein before
described is repeated.
We do not limit ourselves to the arrangement of mechanism herein before
described by which the rising and falling of the mercury in the outlet chamber is
caused to operate the stop cocks aforesaid as other arrangements of mechanism
may be used.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Johnson and Samuel Charles Tisley in the Great Seal
Patent Office on the 4th November 1882.
DAVID JOHNSON of Barrelwell House in the City and County of Chester
Gentleman and SAMUEL CHARLES TISLEY of No. 172 Brompton Road in the
County of Middlesex Optician. "IMPROVEMENTS IN MERCURIAL AIR PUMPS."
Our Invention consists first of the improvements hereinafter described in the
apparatus known as "Spreingle's pump" by which improvements the quantity of
mercury and the power required for producing a given result with the said apparatus
are reduced a better vacuum is produced and the said apparatus is rendered capable
of being worked more rapidly than the ordinary apparatus and by means of any
suitable motor.
According to this part of our invention we mount a number of tubes vertically
in brackets affixed to a suitable standard the upper ends of the said tubes (which
correspond with the dropping tubes in Spreingle's pump) are all at the same level
and open into a sealed chamber the upper part of which is provided with a tube to
which the article or articles to be exhausted is or are connected.
The lower ends of the dropping tubes aforesaid open into a chamber or vessel
into which the mercury from them passes which chamber or vessel communicates
by means of a tube with a suitable pump which also communicates with the
interior of the upper chamber by means of a tube the top of which is at a lower
level than the tops of the dropping tubes.
The tube at the upper part of the upper chamber is provided with a stop cock
by closing which before removing the article or articles which has or have been
exhausted the vacuum or partial vacuum in the said chamber is preserved. The
said tube is or may be also provided with branch tubes having stop cocks by
means of which any required gases may be admitted to the article or articles being
exhausted.
The apparatus is provided with an ordinary mercurial barometer for showing
the pressure of the atmosphere and beside it a glass tube open at top and bottom is
set vertically the upper end being within the aforesaid upper chamber and above
the level of the tops of the dropping tubes and the lower end dipping into the
mercury cistern of the said barometer. This tube corresponds with the "comparative
tube" of an ordinary "Spreingle pump" and by comparing the height of the
mercury in it with the height of that in the said barometer the extent of
rarefication of the air in the upper chamber may be ascertained.
The pump or apparatus which we prefer to use for forcing the mercury from
the lower to the upper chamber consists of a tube of india rubber around which a
strip of flexible non elastic fabric is wrapped the marginal parts of which strip of
fabric are then secured together and form a tange by which the said tube is
secured in the form of a circle to the surface of a flat board or plate on which and
in the centre of the circle a rotatory shaft is mounted in suitable bearings the said
shaft having affixed to it radial arms which carry rollers which bear on the said
tube and compress it at parts where they bear. By connecting the ends of this
tube one to the tube leading from the lower chamber or vessel hereinbefore
referred to and the other to the lower end of the tube hereinbefore described as
passing from the pump to the upper chamber and by giving rotatory motion to
the aforesaid shaft in the required direction the mercury entering the india rubber
tube from the said lower chamber is pressed through the said india rubber tube
and forced into the upper chamber.
Figure 1 of the accompanying drawings is an elevation and Figure 2 is a plan

page_text: partly in section (taken on the line A Figure 1) of the improved mercurial air
pump herein before described the apparatus hereinbefore described for causing the
required flow of the mercury being shown in connection with the said pump.
The same letters and Figures of reference indicate the same parts in the said
Figures 1 and 2.
a is the frame or standard of the air pump 6b are the dropping tubes and a¹ a²
are the brackets in which they are mounted c is the chamber enclosing the upper
ends of the said tubes b b which chamber consists of a dome shaped glass vessel
the open part of which is cemented air tight in a groove formed in the upper side
of the bracket a', and d is the vessel into which the lower ends of the said tubes
dip. cis the tube communicating with the chamber c to which tube the article
or articles to be exhausted is or are connected and c² is a branch tube by which
any required gases may be admitted to the article or articles being exhausted.
care stopcocks by which the said tubes may be closed when required. e is
the tube communicating between the vessel d and the pump or apparatus for
causing the required flow of the mercury and f is the tube communicating
between the chamber c and the said pump or apparatus the upper end of which
tube is at a lower level than the upper ends of the tubes b b. g is the
tube of the barometer g¹ is the mercury cistern thereof and his the "com-
parative tube" the lower end of which dips into the mercury cistern g¹. the
top being within the chamber c and at a higher level than the tops of the
dropping tubes b b. The vessels d and g¹. are supported in brackets a³. at.
secured to the standard ai is the tube of the apparatus for causing the required
flow of the mercury the ends of which tube are connected respectively with the
tubes and fj is the board to which the tube is secured as herein before
described being the strip of flexible fabric wrapped around the said tube the
marginal parts of which strip of fabric are secured to the said board by a ring j
screwed down over them. Figure 3 is a section of part of the said tube and of the
said strip and board drawn to a larger scale, k is the rotatory shaft mounted in
bearings on the board and in a standard which board and standard are affixed
to a base m. . . are the radial arms affixed to the said shaft k and . . are the
rollers carried by the said arms which rollers bear on the tube i and n is a driving
pulley by which motion is communicated to the shaft from any suitable motor.
In order that the rollers k³. 2. may be readily thrown into and out of action
without stopping the shaft the arrangement hereinafter described is used. o is
a weighted lever on which is formed a spiral incline o¹ which lever is mounted
loosely on the said shaft k and bears on one side against a correspondingly formed
incline affixed to the board j and on the other side against a collar 3. formed
on the shaft k. o². is a handle formed on the said lever by which it may be turned
to one or other side of the shaft as required. The said lever o when in the
position shown in the drawings (Figure 2) causes the rollers to bear on and
compress the tube i and when the said lever is turned to the other side the pressure
of the said rollers on the tube is relaxed. The apparatus hereinbefore described
is used and acts as follows:-The vessel or article to be exhausted having been
connected to the tube c¹. and the lever having been turned to the side necessary
to cause the rollers k². of the pump to bear on the tube i the shaft k of the said
pump is set in motion. Mercury is thus drawn from the vessel d through the
tube e to the tube i and forced thence through the tube into the chamber c
where it rises to the level of the tops of the tubes bb down which it passes in
drops the air contained in the said chamber also passing down the said tubes
between the drops of mercury. The air contained in the vessel or article con-
nected to the tube c¹. is thus rarefied the extent of rarefication being shown by
the height to which the mercury rises in the comparative tube h When it is
desired to admit a gas or gases to the said vessel or article the tube c². is connected
to a reservoir of the required gas or gases and the stopcock c³. is opened. When
the vessel or article is sufficiently exhausted the stopcock c. is closed and the said
vessel or article is disconnected from the tube c'.

page_text: Instead of the apparatus herein before described for raising the mercury from the
vessel d to the chamber c an ordinary forcing pump or any other suitable pump
may be used or the tubes e f may be connected to a bag formed of a suitable
flexible material and attached to a cylinder or chamber against which bag a piston
or plunger works the working of which piston or plunger compresses the bag and
allows it to expand alternately thus drawing and foreing the mercury as required.
In these cases valves are required in order that the mercury may be caused to pass
in the proper direction.
The valves which we prefer for preventing the return of the mercury in the
tubes connected with the pump consist of pieces of india rubber tubing compressed
at one end while the rubber is warm or in a plastic state. The pieces tubing are
thus permanently flattened at one end and though (owing to the elasticity of the
rubber) they are capable of being opened by pressure from within they cannot be
opened by pressure from without. Pieces of tubing thus compressed when secured
in or over the ends of the tubes conveying the mercury allow it to pass freely in
one direction but prevent it from passing in the reverse direction. A valve of this
kind is illustrated in side view and longitudinal section drawn to a large scale in
Figures 4 and 5 of the accompanying drawings f. f. being portions of the tube f.
2 the piece of india rubber tubing bound over the end of the tube f' p¹ the
flattened end of the said india rubber tubing and q another india rubber tube
bound at one end over the end of the tube f¹. and at the other end over the end of
the tube f³.
When pumps are used which cause an intermittent flow of the mercury through
the tubes we prefer to form a bulb or enlargement in a suitable part of the tube
communicating between the pump and the upper chamber which bulb constitutes
an air chamber the elasticity of the air in which absorbs the shocks caused by the
said intermittent flow of mercury from the pump.
.
Although we prefer to provide our improved apparatus with a number of
dropping tubes as hereinbefore described one only may be employed.
That part of the improvements hereinbefore described which consists in raising
the mercury from the lower chamber to the upper chamber without allowing the
said mercury to come in contact with air in its passage may be applied to Spreingle
pumps of the ordinary construction.
"
Our invention consists further of improvements in the apparatus originally
known as the "Geissler air pump which apparatus as ordinarily constructed
consists of a chamber (termed the exhausting chamber) to the upper and lower
parts of which tubes are connected that from the upper part dipping into an open
vessel containing mercury (termed the "outlet chamber") and set at a lower level
than the exhausting chamber and that from the lower part communicating at its
extremity by means of a flexible tube with a vessel containing mercury (termed
the "lifting bulb ") and at a point a little below the exhausting chamber with a
syphon tube (termed the connecting tube) to the free end of which the article to
be exhausted is connected. By alternately raising and lowering the lifting bulb
the air in the said article and in the tube and exhausting chamber is driven out
through the mercury in the outlet chamber.
Our improvements in the said apparatus consist in substituting a flexible bag
containing mercury for the lifting bulb which bag we enclose in a chamber to
which gas steam compressed air or water under pressure may be admitted by
means of a pipe provided with a stopcock and from which the said gas steam
compressed air or water may be allowed to escape by means of another pipe
provided with a stop cock which stopcocks are connected by a rod to a lever
mounted above the outlet chamber to which lever is also connected another rod
which descends into the outlet chamber and carries two blocks of iron one above
the other the upper one being secured to the said rod and the lower one being free
to slide upon it the upward motion of the said lower block being limited by the
fixed block and its downward motion being limited by a stop on the said rod. By
this means the stopcocks are worked automatically by the rise and fall of the

page_text: <
mercury in the outlet chamber the rising of the mercury (caused by compression
of the flexible bag) carrying up the iron blocks and thereby raising the rod carrying
them and the lever and thus opening the outlet cock and closing the inlet cock
and the fall of the mercury (consequent on the pressure being removed from the
bag) causing the blocks and lever to fall thus reversing the position of the said
cocks.
"
Figure 6 of the accompanying drawings is an elevation partly in section of a
Geissler pump to which our improvements are applied. a is the exhausting
chamber b is the connecting tube c is the outlet chamber d is the tube connecting
the exhausting chamber b with the outlet chamber and e is the tube to the lower
end of which the "lifting bulb" is ordinarily connected is the bag which we
substitute for the said lifting bulb g is the chamber containing the said bag his
the pipe provided with a cock h¹ by which the gas steam compressed air or water
under pressure is admitted to the said chamber and i is the pipe provided with a
cock by which the gas steam air or water is allowed to escape j is the lever
nounted above the outlet chamber c, is the rod by which the said lever is con-
nected to the cocks h¹ and is the rod connected to the said lever and descending
into the said outlet chamber. is the block of iron secured to the said rod, 1² is
the block of iron which is free to slide thereon and 3 is the stop which limits the
downward motion of the block 12. The action of this apparatus is as follows:-
The pipe being connected to a reservoir of gas steam compressed air or water
under pressure the gas steam air or water therefrom enters the chamber g and
compresses the bag f containing the mercury which is thereby forced up into the
exhausting chamber a and from the tube a connected there with into the outlet
chamber c the rising of the mercury in which chamber causes the block of iron 12
to rise on the rod until the said block meets the upper block when the said rod
and the lever j are raised and the stop cock h' is thereby turned so as to shut off
communication between the reservoir of gas steam air or water and the stopcock ¿¹
is turned so as to open the escape pipe i. The pressure being thus removed the
mercury in the exhausting chamber a returns to the bag f and part of that in the
outlet chamber c rises in the tube d. The rod and lever j being thus allowed to
descend the stopcocks are again turned the escape pipe i being thereby closed and
the inlet pipe opened when the action hereinbefore described is repeated.
We do not limit ourselves to the arrangement of mechanism herein before
described by which the rising and falling of the mercury in the outlet chamber is
caused to operate the stopcocks aforesaid as other arrangements of mechanism may
be used.
Instead of compressing the flexible bag containing the mercury by means of the
gas steam air or water as hereinbefore described the said flexible bag may be
compressed by any other suitable means the main feature of this part of our
invention consisting in forcing the mercury from its receptacle into the pump and
allowing it to return therefrom to the said receptacle by alternately pressing on
and removing the pressure from the said mercury instead of by alternately raising
and lowering the receptacle containing the mercury as in Geissler pumps of the
ordinary construction.
Having thus described the nature of our Invention and the manner in which it
is to be performed we wish it to be understood that we do not limit ourselves to
the precise details herein before described as they may be varied without departing
from the nature of our Invention but
We claim in respect of that part of our invention which relates to improvements
in mercurial air pumps of the kind known as Spreingle pumps.
First Enclosing the upper ends of the dropping tubes in an air tight chamber
to which the article to be exhausted may be connected and from which the said
article may be disconnected without admitting air to the said chamber and causing
the mercury to pass to the said air tight chamber from the vessel or chamber at
the lower ends of the dropping tubes without the said mercury being exposed to

page_text: contact with air in its passage substantially as herein before described with reference
to Figures 1 and 2 of the accompanying drawings.
Secondly-Causing the mercury in a Spreingle pump to pass from the vessel or
chamber at the lower ends of the dropping tubes to the vessel or chamber at the
upper ends of the said tubes without being exposed to contact with air in its
passage substantially as herein before described.
Thirdly-The general arrangement and combination of parts constituting the
improved apparatus herein before described with reference to and illustrated in
Figures 1 and 2 of the accompanying drawings.
We claim in respect of that part of our Invention which relates to improvements
in mercurial air pumps of the kind known as Geissler pumps.
Fourthly The substitution of a flexible bag containing mercury for the ordinary
lifting bulb the mercury in the said flexible bag being alternately forced into and
allowed to return from the tubes and exhausting chamber of the pump by
alternately compressing the said bag and allowing it to expand substantially as
hereinbefore described.
Fifthly The arrangement hereinbefore described and illustrated in Figure 6 of
the accompanying drawings for causing the alternate compression and expansion of
the flexible bag connected to the exhausting chamber that is to the say the
arrangement of the said bag within a closed chamber to which steam compressed
air or water under pressure is admitted and from which the said steam compressed
air or water under pressure may be allowed to escape as required by mechanism
actuated by a float or floats working in the outlet vessel and raised or lowered by
the mercury rising and falling therein substantially as hereinbefore described and
illustrated in the accompanying drawings.
In witness whereof I the said Samuel Charles Tisley have hereunto set my
hand and seal this fourth day of November in the year of our Lord one
thousand eight hundred and eighty two.