A NEW OR IMPROVED COMPRESSED AIR AND EXHAUSTION HAMMER
Year: 1860

page_text: LETTERS PATENT to Thomas Geast Dawes, of Wolverhampton, in the
County of Stafford, Iron Merchant, for the Invention of "A NEW OR
IMPROVED COMPRESSED AIR AND EXHAUSTION HAMMER."
Sealed the 15th May 1860, and dated the 17th January 1860.
PROVISIONAL SPECIFICATION left by the said Thomas Geast Dawes at
the Office of the Commissioners of Patents, with his Petition, on the
17th January 1860.
I, THOMAS GEAST DAWES, of Wolverhampton, in the County of Stafford,
Iron Merchant, do hereby declare the nature of the said Invention for
"A NEW OR IMPROVED COMPRESSED AIR AND EXHAUSTION HAMMER," to be as
follows:-
My Invention consists of a new or improved haminer, which may be used
as a forge hammer, tilt hammer, or stamp, and actuated, as herein-after
described, by means of compressed air on one side of a piston and exhaustion
or rarefaction of the air on the other side of the said piston.
In carrying my Invention into effect, I take two cylinders, which may
either be similar or dissimilar in size, the said cylinders being closed both at
top and bottom, and provided with tightly-fitting pistons. The said cylinders
communicate with one another both at top and bottom by means of pipes or
passages. The piston rod of one of the cylinders passes through a stuffing
hox at the top of the cylinder, and the piston rod of the other or hammer

page_text: cylinder passes through a stufling box at the bottom of the cylinder, or the
piston rods may both pass out at the bottoms of their respective cylinders.
The former piston rod is raised and depressed by a crank or other mechanical
agent, and the ram or hammer is attached to the latter piston rod. The
-working-or-motive cylinderniaybe placed in anyeonvenient-position-when-the-
piston in the first-named cylinder is raised; the air above it is forced into the
other cylinder on the upper side of the piston tending to depress the latter
piston. The exhaustion on the under side of the first and rising piston pro-
duces a corresponding exhaustion on the under side of the piston of the
second cylinder, and thus the motion of the piston in one cylinder communi-
cates to the piston in the other cylinder motion in a contrary direction.
I sometimes modify my Invention in the following manner :-Instead of
moving a piston in the second cylinder I make the piston stationary, and
cause the cylinder to move; I effect this by making the fixed piston rod of
the second cylinder hollow, and containing two passages, one of the said
passages communicates between the top of the first cylinder and the top of
the fixed piston of the second cylinder, the other pessage communicates
between the bottom of the first cylinder and the under side of the fixed piston
in the second cylinder. By this arrangement the motion of the pistou in the
first cylinder produces the motion in a similar direction of the second cylinder
upon its fixed piston. I fix a stop-cock both on the top and bottom of the
cylinders to regulate the blow of the hammer by the admission or explusion
of air.
by the said Thomas Geast Dawes, in the Great Seal Patent Office ou
the 14th July 1860.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, THOMAS
GEAST DAWES, of Wolverhampton, in the County of Stafford, Iron Merchant,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Seventeeth day of January, in the year of our Lord
One thousand eight hundred and sixty, in the twenty-third year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the said
Thomas Geast Dawes, Her special licence that I,the said Thomas Geast Dawes,
my executors, administrators, and assigus, or such others as I, the said Thomas
Geast Dawes, my executors, administrators, and assigns, should at any

page_text: time agree with, and no others, from time to time and at all times there-
after 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 "A NEW
OR IMPROVED COMPRESSED A IR AND EXHAUSTION HAMMER," upon the condition
(amongst others) that I, the said Thomas Geast Dawes, my executors or
administrators, by an instrument in writing under my, or their, or one of their
handsand 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 saine 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 Geast Dawes, 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 thereof, that is to say:
My Invention consists of a new or improved hammer, which may be used
as a forge hammer, tilt or other hammer, or as a stamp or press, and actuated,
as herein-after described, by means of compressed air on one side of a piston,
and exhaustion or rarefaction of the air on the other side of the said piston.
In carrying my Invention into effect, I construct two cylinders, which may
either be similar or dissimilar in size. Supposing the cylinders to be both the
same length, I prefer the motor cylinder to be at least double the area of the
hammer cylinder, but I prefer the hammer cylinder being longer than the
motor one. If, for instance, it is double the length, then the motor cylinder
should be at least four times the area of the hammer cylinder, or as much
larger as may be found convenient; for it is evident that the larger (in reason)
the motor cylinder is in proportion to the hammer one, so much greater will
be the compression of air below the hammer piston and rarefaction above it.
The said cylinders are closed both at top and bottom, and provided with
tightly-fitting pistons. The said cylinders communicate with one another both
at top and bottom by means of passages; the piston rod of one or motor
cylinder passes through a stuffing box at the top of the cylinder, and the piston
rod of the other or hammer cylinder passes through a stuffing box at the
bottom of the cylinder, or the piston rods may both pass out through the
bottoms of their respective cylinders. The former piston rod, that is to say,
the piston rod of the motor cylinder, is raised and depressed by a crank or
other mechanical agent, and the ram or hammer is attached to the latter
piston ro', that is to say, the piston rod of the hammer cylinder. The
cylinders, or one of them, may be placed either in a vertical or horizontal

page_text: position, or inclined at any desired angle between these positions; I will.
however, explain the action of my Invention with reference to a vertical
position of the cylinders. I will suppose the piston of the motor cylinder to
be at the top of its cylinder, and the piston of the hammer cylinder to be at
the bottom of its cylinder; then, when the piston-of-the-motor-cylinder
descends, it forces its compressed air under the piston of the hammer cylinder
at the same time that it rarefies the air above it, and so causes the hammer
piston to rise, and with it the hammer. When the motor piston ascends, it
extracts the compressed air from beneath the hammer piston at the same time
that it returns the air which, in the previous down stroke of the motor piston,
had been extracted from above the hammer piston to the top of the hammer
piston (or as much more as may have been let into the motor cylinder by the
stop-cock or valve herein-after described), and causes the hammer to descend.
Thus the motion of the piston in the motor cylinder communicates to the
piston in the hammer cylinder motion in a contrary direction.
I sometimes modify my Invention in the following manner:-Instead of
moving a piston in the hammer cylinder I make the piston stationary, and
cause the cylinder to move; the hammer in this case is fixed to the bottom of
the cylinder. In this modification of my Invention 1 make the rod of the
hammer cylinder fixed and hollow and containing two passages, or there may
be two hollow fixed piston rods instead of one piston rod with two passages;
one of the said passages communicates between the top of the motor cylinder
and the bottom of the fixed piston of the hammer cylinder. The other
passage communicates between the bottom of the motor cylinder and the
upper side of the fixed piston in the hammer cylinder. By this arrangement
the motion of the piston in the motor cylinder produces the motion in a
contrary direction of the hammer cylinder upon its fixed piston. The con-
nection between the motor cylinder and the passages may be reversed, which
makes the hammer cylinder move in the same direction as the motor piston.
I fix a valve opening inwards on the bottom of the motor cylinder, which
-valve-is-self-acting, and restores-to the under side of the motor piston any air
that may have escaped during the downward stroke. I also affix a stop-cock
or valve on the top of the notor cylinder, which is opened for au instant by a
cam or other contrivance, and closes itself by a spring or weight just before
the motor piston reaches the top of the cylinder. The object of the said stop-
cock or valve is to restore the equilibrium of air in the hammer cylinder. I
also open and close the said stop-cock or valve, if requisite, just before the
motor piston reaches the bottom of the cylinder, so as to fill the motorcylinder
with air, which cylinder I am assuming to be the larger. By this means I

page_text: get as great a compression of air above the hammer piston as below it,
although the motor cylinder is ever so much larger than the hammer cylinder.
I also affix a stop-cock or valve at the top and bottom of the hammer
cylinder, or on the passages when the cylinder moves to regulato the blow of
the hammer. The last-named stop-cocks or valves are opened by hand at
pleasure to regulate the blow. By increasing the size of the motor cylinder,
I obtain great compression of air under the piston in the smaller or hammer
cylinder, enabling me to work a heavy hammer with comparatively a small
hammer cylinder. I am also able thereby to make the hammer move through
a large stroke or compass while the motor piston is moving through a short.
one, whereby great speed may be obtained. The hammer ram or the hammer
cylinder, when the cylinder is moveable, moves in guides. I use suitable
buffers to prevent the hammer ascending too high, and I also use safety valves
if required.
Having now described the nature of my Invention, and the manner of
carrying the same into effect, 1. wish it to be understood that I do not limit
myself to the precise details herein described, as the same may be varied
without departing from the nature of my Invention; but I claim, as my
Invention, the new or improved compressed air and exhaustion hammer
herein-before described, that is to say, the arrangement or combination of
parts herein-before described, whereby the motion of a piston in a motor
cylinder is made to compress the air on one side, and exhaust the air on the
other side of a pisten in another or hammer cylinder, and thereby move the
piston of the said hammer cylinder, or where the said piston of the hammer
cylinder is fixed, to move the cylinder upon the said fixed piston, the hammer
being attached to the piston of the hammer cylinder when the said hammer
cylinder is fixed, and to the said hammer cylinder itself when the said
hammer cylinder is moveable on a fixed piston.
In witness whereof I, the said Thomas Geast Dawes, have hereunto set
any hand and seal, this Twelfth day of July, in the year of our Lord
One thousand eight hundred and sixty.
Witness,
JAMES TYRER:
THOMAS GEAST DAWES. (L.s.)