IMPROVE- MENTS IN PNEUMATIC PUMPS
Year: 1873

page_text: LETTERS PATENT to Henry Bernoulli Barlow, of Manchester, in the
County of Lancaster, Patent Agent, for the Invention of "IMPROVE-
MENTS IN PNEUMATIC PUMPS."-A communication from abroad by
Sealed the 22nd August 1873, and dated the 26th March 1878.
PROVISIONAL SPECIFICATION left by the said Henry Bernoulli
Barlow at the Office of the Commissioners of Patents, with his
Petition on the 26th March 1878.
I, HENRY BERNOULLI BARLOW, of Manchester, in the County of
Lancaster, Patent Agent, do hereby declare the nature of the said In-
vention for "IMPROVEMENTS IN PNEUMATIC PUMPs," being a communication
to me from abroad by Nicolas Joseph Galland, of Paris, France,
Engineer, to be as follows:-
This improved pneumatic pump consists of two chambers united by a
bent pipe, and it resembles a syphon barometer, the two chambers must
be of the same capacity, and they as well as the bent pipe are full of oil

page_text: or other suitable liquid, the lower chamber is provided with a plunger
which is worked by a steam engine or other power, and the upper one
is in communication with the vessel in which the vacuum or partial
vacuum is to be formed, in the upper chamber is a float connected to a
valve which opens and closes the end of the pipe leading to the vessel to
be exhausted. Near the top of the upper vessel is the discharge valve,
and above it is a small chamber containing oil or other liquid to exclude
the air. As the plunger moves up and down it sucks the air, vapour, or
gas out of the vessel to be exhausted, and forces it out through the
discharge valve. By closing the chamber above the discharge valve, and
exhausting the air from it by a second plunger a more perfect vacuum
can be formed in the vessel to be exhausted.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Henry Bernoulli Barlow in the Great Seal Patent
Office on the 24th September 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, HENRY
BERNOULLI BARLOW, of Manchester, in the County of Lancaster, Patent
Agent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-sixth day of March, in the year
of our Lord One thousand eight hundred and seventy-three, in the thirty-
sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Henry Bernoulli Barlow, Her
special licence that I, the said Henry Bernoulli Barlow, my executors,
administrators, and assigns, or such others as I, the said Henry
Bernoulli Barlow, my executors, administrators, and assigns, should at
any time agree with, and no others, from time to time, and at all times
thereafter during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Invention
for "IMPROVEMENTS IN PNEUMATIC PUMPS," being a communication to me
from abroad by Nicolas Joseph Galland, of Paris, France, Engineer,
upon the condition (amongst others) that I, the said Henry Bernoulli
Barlow, my executors or administrators, by an instrument in writing

page_text: under my, or their, or one otheir hands and seals, should particularly
describe and ascertain the nature of the said Invention, and in what
manner the same was to be performed, and cause the same to be filed in
the Great Seal Patent Office within six calendar months next and imme-
diately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Henry Bernoulli Barlow, do
hereby declare the nature of the said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement (that is to say) :—
This improved pneumatic pump consists of two chambers united by a
bent pipe and it resembles a syphon barometer, the two chambers must
be of the same capacity and they as well as the bent pipe are full of oil
or other suitable liquid, the lower chamber is provided with a plunger
which is worked by a steam engine or other power, and the upper one is
in communication with the vessel in which the vacuum or partial vacuum
is to be formed, in the upper chamber is a float connected to a valve
which opens and closes the end of the pipe leading to the vessel to be
exhausted. Near the top of the upper vessel is the discharge valve and
above it is a small chamber containing oil or other liquid to exclude the
air. As the plunger moves up and down it sucks the air, vapour,
or gas out of the vessel to be exhausted and forces it out through the
discharge valve. By closing the chamber above the discharge valve,
and exhausting the air from it by a second plunger a more perfect
vacuum can be formed in the vessel to be exhausted.
And in order that the Invention may be fully understood and readily
carried into operation, I will proceed to describe the accompanying
Sheet of Drawings in which Fig. 1 is a vertical section of my improved
pneumatic pump taken through the line 3, 4, on Fig. 2, which is a
section through the line 1, 2, on Fig. 1, and Fig. 3 is a plan.
A is a cylindrical vessel the lower end of which is in communication
by the tube T with the force pump P which is worked by steam or other
power. The valve 8 is in the upper part of the vessel A which is pro-
longed to form a chamber B. The pump P, and the tube T are full of
oil or other liquid. The bent end of the pipe D enters the vessel A, and
it is closed by the cup valve C, this valve is connected to the float F
and they are both put in motion by the liquid of the pump, a portion of
which is left in the vessel A. as the plunger p rises. The chamber B

page_text: also contains a portion of the liquid up to the line N so as to leave a
depth of some inches above the valve S, and to prevent the passage of
air when the valve is up. The contents of the vessel A must be equal
to that of the pump P so that when the plunger is down the liquid shall
be raised up to the valve S. The pipe D is in communication with the
receiver I, in which the vacuum is to be formed. It is therefore evident
that when the pump P is set to work it will exhaust the air or gas from
the receiver I and will blow it out through the valve 8.
In some cases it is necessary to use a liquid that will not give off
vapour to reduce the vacuum; water would produce this result. I find
oil to give the best results in practice as the boiling point is much
higher than that of water.
In order to provide for the waste of the liquid in the joints of the
pump I make a small hole o in the conical cover of the vessel A, which
hole allows a little stream of the liquid to enter the vessel A so long as
the pressure in the interior is not balanced by that on the small hole.
At every stroke of the pump this excess of liquid will be forced back
with the air or gas through the hole o and the valve S. By this appa-
ratus all injurious space is avoided, and a vacuum is formed sufficiently
perfect for most purposes.
A higher degree of perfection may be attained by adopting the system
known in France as "Babinetts," and by employing a second pump
which would draw the liquid from the first; in this case the chamber B
would have to be closed by a valve, a vacuum having then been made in
the chamber B the pressure is greatly reduced on the valve S and small
hole o, and the danger of the liquid retaining globules of air or gas
which would re-enter the vessel A. is reduced. By this means a perfect
vacuum is obtained.
In conclusion I wish to remark that in order to economise oil it is not
necessary to have the pumps and the tubes full of oil, it is sufficient to
fill them with water from which air or gas has been removed, and to
cover the surfaces with oil to the required depth.
Having thus stated the nature and particulars of the Invention com-
municated to me by the within named Nicolas Joseph Galland, I declare
that I claim as my improvements in pneumatic pumps the application
of the system of the syphon barometer, as shewn and described; I also

page_text: claim the application thereof to all practical purposes, and the use of a
liquid or of two liquids of different density to prevent the drawing of air
as described.
In witness whereof, I, the said Henry Bernoulli Barlow, have hereto
set my hand and seal, this Twenty-third day of September One
thousand eight hundred and seventy-three.
as described.
In witness whereof, I, the said Henry Bernoulli Barlow, have hereto
set my hand and seal, this Twenty-third day of September One
thousand eight hundred and seventy-three.
H. B. BARLOW. (18.)