IMPROVEMENTS IN STEAM HAMMERS
Year: 1857

page_text: LETTERS PATENT to Richard Martin, Ebenezer Hall, and Joshua Hall,
trading under the style or firm of Martin, Hall, & Co., Silver Platers,
of Shrewsbury Works, Sheffield, in the County of York, for the Invention
PROVISIONAL SPECIFICATION left by the said Richard Martin, Ebenezer,
Hall, and Joshua Hall at the Office of the Commissioners of Patents,
with their Petition, on the 31st October 1857.
We, RICHARD MARTIN, EBENEZER HALL, and JOSHUA HALL, trading under
the style or firm of Martin, Hall, & Company, Silver Platers, of Shrewsbury
Works, Sheffield, in the County of York, do hereby declare the nature of
the said Invention for "IMPROVEMENTS IN STEAM HAMMERS," to be as follows:-
This Invention relates to a peculiar construction of forging or stamping
hammers to be worked by the intermittent action of steam and the atmo-
sphere. It consists of a cylinder open at the lower extremity, with a valve
near the top for the admission of the steam above the piston. To the top of
the piston rod is attached a rope which passes over pullies, and to it is secured.
the hammer or weight, which moves in a vertical frame. This frame may be
fixed at any required distance from the cylinders. The steam is conducted
by a tube or pipe, the discharge of which is regulated at pleasure by a stop-
tap to a steam chest in which a slide valve works. The valve employed is
of the ordinary construction, but with a triangular slot on the upper part of
the sliding face, so that as the valve is being opened a thin jet of steam is

page_text: admitted, when the apex of the slot passes below the top of the inlet. The
flow of steam gradually increases with the increasing area of the slot, until on
the complete opening of the valve the full volume of steam is admitted; this
depresses the piston, which draws the rope and weight with it. The required
depression of the piston, and consequent elevation of the weight or hammer
being attained, the movement of a lever closes the steam valve and opens
at the same instant a stop-tap attached to the exhaust pipe, the pressure of
the atmosphere on the under side of the piston then assists the descent of the
hammer, which falls with such momentum as may be required, according to
the length of cylinder and size of hammer or weight employed.
SPECIFICATION filed in pursuance of the conditions of the Letters Patent,
and of an Order of the Lord Chancellor, by the said Richard Martin,
Ebenezer Hall, and Joshua Hall in the Great Seal Patent Office on
the 26th May 1858.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, RICHARD.
MARTIN, EBENEZER HALL, and JOSHUA HALL, trading under the style or firm
of Martin, Hall & Co., Silver Platers, of Shrewsbury Works, Sheffield, in the
County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Thirty-first day of October, in the year of our
Lord One thousand eight hundred and fifty-seven, in the twenty-first year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto us,
the said Richard Martin, Ebenezer Hall, and Joshua Hall, Her special licence
that we, the said Richard Martin, Ebenezer Hall, and Joshua Hall, our
executors, administrators, and assigns, or such others as we, the said Richard
Martin, Ebenezer Hall, and Joshua Hall, our 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 STEAM HAMMERS," upon the condition (amongst others)
that we, the said Richard Martin, Ebenezer Hall, and Joshua Hall, our
executors or administrators, by an instrument in writing under our, or their,
one of our or 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

page_text: Patent Office within six calendar months next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that we, the said Richard Martin, Ebenezer Hall, and
Joshua Hall, do hereby declare the nature of our 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):-
Our Invention relates to forging or stamping hammers, or machines for pile
driving and such like purposes worked by the intermittent action of steam and
the atmosphere. It consists of a cylinder open at the lower extremity, with a
valve near the top for the admission of the steam above the piston; to the top
of the piston rod is attached a rope which passes over pulleys, and to it is
secured the hammer or weight which moves in a vertical frame; this frame
may be fixed at any required distance from the cylinder.
The steam is conducted by a tube or pipe, the discharge of which is regu-
lated at pleasure by a stop-tap, to a steam chest in which a slide valve works;
the valve employed is of the ordinary construction, but having a triangular
notch on the upper part of the sliding face, so that as the valve is being opened
a thin jet of steam is admitted when the apex of the notch passes below the
top of the inlet; the flow of steam gradually increases with the increasing area
of the notch until on the complete opening of the valve the full volume of
steam is admitted; this depresses the piston which draws the rope and weight
with it. The required depression of the piston and consequent elevation of
the weight or hammer being attained the moment of a lever shuts off the
steam, and opens at the same instant an orifice communicating with a
chamber to which the discharge pipe is attached; the pressure of the atmo-
sphere on the underside of the piston then assists the descent of the hammer,
which falls with such momentum as may be required according to the length
of cylinder and size of hammer or weight employed.
In the accompanying Drawings we have exhibited the arrangement con-
templated by our said Invention, similar parts in each Figure being marked
by similar letters of reference.
Fig. 1 is a side elevation shewing the cylinder, the framework and all the
connecting parts; Fig. 2 is a horizontal section through a, b, (see Fig. 1);
Fig. 3 is a vertical section through c, d, (see Fig. 2); and Fig. 4 is a
vertical section of the slide valve through e, f, (see Fig. 3)...
The cylinder A may be secured by framing and bolted at the bottom to any
fixed body, through a washer corresponding with the flange at the bottom of
the cylinder, which is open for the free admission of air; the top of the
cylinder is rendered steam-tight by a cap B, and stuffing box C, through which

page_text: the piston rod D works. The steam chest E is fitted with a slide valve F,
notched at the top, as shown in Fig. 4, and formed with an exhaust concavity
which is large enough when in position to embrace the steam port y and the
exhaust port z: the motion of this valve is regulated by a lever G, to which
it is connected by the rod H, working through a stuffing box in the top of the
steam chest. The off steam passage i is fitted with a pipe K, through which
the waste steam is discharged. To the top of the piston rod D the hammer
or weight is attached in the manner shewn in Fig. 1, the: rope or chain L
passing over the pulleys M &..N, the other end of the rope being attached
to the weight or ram block Q.
When by the action of the lever G the slide valve is pressed to the bottom
of the steam chest, the steam will pass through the port y into the cylinder and
depress the piston d' until the valve is again raised by means of the lever G, till
the upper face of the slide valve covers the steam port y, whereby the com-
munication between the steam chest and cylinder is stopped, and the motion
of the piston arrested. The weight or ram block O being connected with the
piston rod D, through the rope L, is, by admitting steam into the cylinder,
raised in the same proportion as the piston is depressed; and supposing the
piston to have been forced to the bottom of the cylinder, the ram block will
thereby have been raised in the guide frame P to its maximum height, as
represented in Figs. 1 & 3. If the valve is further raised so as to bring the
exhaust cavity a over the steam port y, whereby a communication is esta-
blished between the steam port y and exhaust port, the discharge of the
steam, and consequent descent of the hammer, will at once commence, the
steam passing through the exhaust cavityx, exhaust port z, channel i, to the
discharge pipe K; the discharge of the steam and consequent fall of the hammer
is accelerated by the pressure of the atmosphere upon the lower surface of the
piston. The discharge of steam may, however, be stopped, and the descent
of the hammer arrested at an elevation desired, by slightly depressing the lever
and altering the position of the valve accordingly. When it is desired to
moderate the force with which the hammer falls, or to strike a blow with less
power than it would acquire in descending the full height of the guide frame,
the object may be accomplished by raising the lever to shut off the steam and
open the communication with the exhaust port, when the hammer attains to such
height as may be necessary to determine the momentum desired. When the
steam port and exhaust port are wholly within the exhaust concavity of the
slide valve, no impediment exists to the free ascent of the piston and consequent
fall of the hammer beyond the resistance due to friction, which is more than
counterbalanced by the atmospheric pressure on the lower surface of the piston.

page_text: For raising the hammer, the valve is slowly depressed, when a thin jet of
steam will pass into the cylinder, as the point Q (see Fig. 4) or apex of the
triangular notch passes below the upper part of the steam port y; and as the
orifice becomes gradually opened, the larger area afforded for the admission of
steam is determined by the gradually increasing area of the triangular or other
notch. By thus gently introducing the steam, motion is gradually imparted
to the piston, before the full volume of steam is admitted, thus avoiding the
wear and tear consequent on the concussions and violent shocks which result
from the immediate admission of a large body of steam.
In the arrangement of the guide frame delineated, and the mode of con-
necting the hammer with the piston rod by a rope or chain passing over
pulleys, there is nothing new. It will be seen, however, that the arrangement
admits of the frame and hammer being placed at such distance from the
working cylinder as circumstances may demand.
Having now described and particularly ascertained the nature of our said
Invention, and the manner in which the same is or may be carried into effect,
we would observe in conclusion, that we do not claim the various parts or
elements of the machinery herein-before described; but what we consider novel
and original, and therefore claim as the Invention to be secured to us by the
above in part récited Letters Patent, is,―
Firstly, the general construction and arrangement of the cylinders employed
in working, forging, or stamping hammers or machines for pile driving and
such like purposes, as set forth and delineated in the accompanying Drawings.
Secondly, the peculiar arrangement of outlet and inlet orifices or ports with
the triangular or other notch in the valve to regulate the admission of steam.
Thirdly, the system or mode of accelerating the ascent of the piston in
steam hammers by atmospheric pressure.
In witness whereof, we, the said Richard Martin, Ebenezer Hall, and
Joshua Hall, have hereunto set our hands and seals, this Thirtieth
day of April, in the year of our Lord One thousand eight hundred
and fifty-eight.
Witness,
T. F. CASHIN,
Sheffield.
RICHARD MARTIN. (L.S.)