IMPROVEMENTS IN MACHINERY FOR COMPRESSING AIR OR GAS, PARTS OF WHICH INPROVEMENTS ARE APPLICABLE TO THE PISTONS AND PISTON RODS OF STEAM ENGINES
Year: 1872

page_text: LETTERS PATENT to Thomas Brown, of Newgate Street, in the
County of Middlesex, Engineer, for the Invention of "IMPROVEMENTS
IN MACHINERY FOR COMPRESSING AIR OR GAS, PARTS OF WHICH INPROVEMENTS
ARE APPLICABLE TO THE PISTONS AND PISTON RODS OF STEAM ENGINES." -A
communication from abroad by Daniel Colladon, of Geneva, Swit-
zerland.
Sealed the 22nd April 1873, and dated the 23rd October 1872.
PROVISIONAL SPECIFICATION left by the said Thomas Brown at the
Office of the Commissioners of Patents, with his Petition, on the
23rd October 1872.
I, THOMAS BROWN, of Newgate Street, in the County of Middlesex,
Engineer, do hereby declare the nature of the said Invention for "In-
PROVEMENTS IN MACHINERY FOR COMPRESSING AIR OR GAS, PARTS OF WHICH
IMPROVEMENTS ARE APPLICABLE TO THE PISTONS AND PISTON RODS OF STEAM
ENGINES," to be as follows:-
My said Invention relates to novel contrivances to be used with the
cylinder, pistons, and piston rods of air or gas compressing machinery.

page_text: for protecting the piston packing and the packing in the stuffing boxes
of the cylinders from the heat developed by the compression of the air
or gas. By the use of these contrivances I am able to obtain a great
pressure of air or gas in a perfectly dry condition, and with great
economy of the motive power.
The said Invention also relates to means for making the joints or con-
nections tight under a very high pressure of air or gas.
In practising my said Invention I construct the pump cylinder with a
jacket or casing forming an annular chamber surrounding the said
cylinder. Through this chamber I maintain a circulation of cold water.
I also make the cylinder covers or ends hollow or with chambers,
through which I cause cold water to flow. I connect a small inlet pipe
to any convenient portion of the cylinder casing and covers, and provide
the same with a suitable outlet aperture, and I thereby maintain a con-
stant circulation of cold water around the cylinder.
The piston and piston rod are also made hollow, and into the piston
rod I insert a small tube, which is supplied with water from a reservoir
or otherwise. I fit inside this tube a pipe, which may be connected to
the said reservoir by a flexible tube. The said small tube has a piston,
which fits the interior of the hollow piston rod. On each side or the
front and rear of this small piston the hollow piston rod has holes, which
form passages between the interior of the piston rod and the cavity of
the large piston. The cold water entering the small tube passes through
the same into the hollow piston, thence it flows through the aforesaid
holes on one side of the small piston into the cavity of the large piston,
returning into the hollow rod on the other side of the small piston, and
escaping from the said rod through an aperture at the end of the same.
The supply of cold water may be regulated by a valve arranged in the
small central tube, to be opened by the external pressure of the water.
The escape of the water is prevented by providing the end of the cylinder
with a stuffing box and gland.
The aforesaid hollow piston and piston rod may be advantageously
employed in steam engines for the admission of steam for heating the
piston and rod.
For making the joints or connections air-tight under a high pressure
I use a rubber tube, through which I pass a length of soft rope, spun
yarn, cotton yarn, or other suitable material. I cut the ends at an angle.

page_text: to overlap each other. By this means I obtain an elastic, durable, and
perfectly tight packing for joints where air, gas, or steam of very high
pressure is employed.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Thomas Brown in the Great Seal Patent Office on
the 23rd April 1873.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
BROWN, of Newgate Street, in the County of Middlesex, Engineer, send
greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-third day of October, in the
year of our Lord One thousand eight hundred and seventy-two, in the
thirty-sixth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said Thomas Brown, Her special licence
that I, the said Thomas Brown, my executors, administrators, and,
assigns, or such others as I, the said Thomas Brown, 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
MACHINERY FOR COMPRESSING AIR OR GAS, PARTS OF WHICH IMPROVEMENTS ARE
APPLICABLE TO THE PISTONS AND PISTON RODS OF STEAM ENGINES," a communi-
cation to me from abroad by Daniel Colladon, of Geneva, Switzerland,
upon the condition (amongst others) that I, the said Thomas Brown,
my executors or administrators, by an instrument in writing under my,
or their, or one of their 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 immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Thomas Brown, 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

page_text: following statement, reference being had to the accompanying Drawings,
forming a part of this Specification.
My said Invention relates to novel contrivances to be used with the
cylinders, pistons, and piston rods of air or gas compressing machinery
for protecting the piston packing and the packing in the stuffing boxes.
of the cylinders from the heat developed by the compression of the air
By the use of these contrivances I am able to obtain a great
pressure of air or gas in a perfectly dry condition, and with great
economy of the motive power.
or gas.
The said Invention also relates to means for making the joints or con-
nections tight under a very high pressure of air or gas.
In practising my said Invention I construct the pump cylinder with
a jacket or casing, forming an annular chamber surrounding the said
cylinder. Through this chamber I maintain a circulation of cold water.
I also make the cylinder covers or ends hollow or with chambers, through
which I cause cold water to flow. I connect a small inlet pipe to any
convenient portion of the cylinder casing and covers, and provide the
same with a suitable outlet aperture, and I thereby maintain a constant
circulation of cold water around the cylinder.
The piston and piston rod are also made hollow, and into the piston
rod I insert a small tube, which is supplied with water from a reservoir
or otherwise. I fit inside this tube a pipe, which may be connected to
the said reservoir by a flexible tube. The said small tube has a piston,
which fits the interior of the hollow piston rod. On each side or the
front and rear of this small piston the hollow piston rod has holes, which
form passages between the interior of the piston rod and the cavity of
the large piston. The cold water entering the small tube passes through
the same into the hollow piston, thence it flows through the aforesaid
holes on one side of the small piston into the cavity of the large piston,
returning into the hollow rod on the other side of the small piston, a
and escaping from the said rod through an aperture at the end of the
same. The supply of cold water may be regulated by a valve arranged
in the small central tube, to be opened by the external pressure of the
water. The escape of the water is prevented by providing a stuffing box
and gland.
. The aforesaid hollow piston and piston rod may be advantageously
emploved in steam engines for the admission of steam for heating the

page_text: For making the joints or connections air-tight under a high pressure
I use a rubber tube, through which I pass a length of soft rope, spun
yarn, cotton yarn, or other suitable material. I cut the ends at an angle
to overlap each other. By this means I obtain an elastic, durable, and
perfectly tight packing for joints where air, gas, or steam of very high
pressure is employed.
I will now more particularly describe my said Invention in connection
with the accompanying Drawings, in which Figure 1 is a longitudinal
section of a cylinder and adjacent parts of a compressed air engine
embodying my Invention; Figure 2 is an end elevation of the same.
A is the cylinder; B and C are the covers of the said cylinder; D is
the piston rod, which has a reciprocating motion through the stuffing
boxes of the cylinder covers; D' is the piston, cast upon or otherwise
attached to the rod D.
F is a small tube somewhat shorter than the interior of the piston
rod D, and through which the cold water is introduced into the said piston
rod D. The said tube is fixed in and moves with the piston rod; it is
fitted with a piston H. The cavity or chamber of the piston D' communi-
cates with the interior of the piston rod D through openings M, N, O, O',
shewn at the front and rear of the small piston H.
The cold water passes in at E through the tube K, and returns by and
into the passage G, passing through the piston apertures M, N, O, O',
thus keeping the piston and piston rod cool. The cold water, after
cooling the piston rod and piston, makes its exit through the passage G¹
and by the outlet R. When this Invention is applied to the cylinder and
piston of a steam engine, as above specified, the steam will enter and
escape in like manner. The escape of the water or steam from the end
of the piston rod is prevented by fitting the end of the said rod with a
stuffing box and gland L.
I connect the tube K with a reservoir placed above the pump by a
flexible rubber tube. The water is forced into the piston rod and piston
through this tube K by the pressure due to the height of the reservoir.
I may regulate the supply of water in proportion to the velocity of the
piston by fixing in the tube K a small valve, which is opened by the
pressure of the water from the outside.
To keep the casing or chamber P round the cylinder and the space or
chamber in the covers of the cylinder sunnlied with water in nion

page_text: lation, a small pipe from the water reservoir is connected to one end of
the cylinder casing, and the water passes through the said spaces and out
at the other, and thus keeping up the circulation.
Having thus fully described the said Invention as communicated to
me by my foreign correspondent, and the manner of performing the same,
I wish it understood that I claim,—
First. The construction of a hollow piston and rod, with the small
tube inside the piston rod and the small piston fitted in the said rod
between the perforations therein, as herein set forth, and for the purpose
specified.
Second. The air or gas compressor, constructed substantially as shown
in the Drawings, and provided with the means herein described for
keeping the joints tight.
In witness whereof, I, the said Thomas Brown, have hereunto set
my hand and seal, this Twenty-third day of April, in the year of
our Lord One thousand eight hundred and seventy-three.
Witness,
W. ROBT. LAKE,
8, Southampton Buildings,
London.
THOMAS BROWN. (L.S.)