IMPROVEMENTS IN STEAM AND OTHER HAMMERS WHEREBY TO EFFECT ECONOMY IN THE USE OF THE STEAM OR OTHER FLUID ACTUATING SAID HAMMERS
Year: 1867

page_text: LETTERS PATENT to David Davy, of Sheffield, in the County of York,
Engineer, for the Invention of "IMPROVEMENTS IN STEAM AND OTHER
HAMMERS WHEREBY TO EFFECT ECONOMY IN THE USE OF THE STEAM OR OTHER
FLUID ACTUATING SAID HAMMERS."
Sealed the 17th December 1867, and dated the 3rd July 1867.
PROVISIONAL SPECIFICATION left by the said David Davy at the Office
of the Commissioners of Patents, with his Petition, on the 3rd July
1867.
I, DAVID DAVY, of Sheffield, in the County of York, Engineer, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN STEAM AND
OTHER HAMMERS WHEREBY TO EFFECT ECONOMY IN THE USE OF THE STEAM OR
OTHER FLUID ACTUATING SAID HAMMERS," to be as follows:-
This Invention consists in a means herein-after described by which an
economy of steam or other elastic fluid, as the case may be, may be effected
above that accomplished by the ordinary system of working such hammers, and
whereby much expenditure of steam or other fluid is in a manner avoided
when the hammer is working with a varying length of stroke.

page_text: The methods by which I propose to accomplish these results are as
follows:-
The cylinder and piston may be constructed in any of the variety of forms
usually adopted, but the distribution of steam or other fluid is effected as
follows: I propose using a piston valve with two or more pistons upon it,
but as an example I will describe one with two pistons. The steam or other
fluid is admitted into the valve chest between the two pistons, and the exhaust
steam passes into the valve chest from the cylinder at each end of the valve,
and thence into the exhaust pipe. The pistons of the valve are hollow, and
around their circumference are ports corresponding with and opposite or
nearly so with other ports in the valve casing; by this means when the valve
is in a certain position a communication is established between 'the top and
bottom of the cylinder. The valve is made to reciprocate in the casing either
by hand or by a self-acting motion. The ports in the valve casing answer
both for the ingress and egress of the steam and for passing it from the top to
the bottom of the hammer cylinder, or vice versa, but the ports around the
circumference of the valve pistons and the passage connecting them together
are only used as a communication for equalizing the pressure of the steam in
the top and bottom of the hammer cylinder.
The mode of operation is as follows:-Supposing the hammer is to be
raised the valve will be moved in a downward direction, admitting the steam
or other fluid to the under side of the piston, and when it has ascended
sufficiently high the valve will be moved in the opposite direction till the
equilibrium ports in the valve are opposite the ports in the casing; a portion
of the steam or other fluid which has raised the hammer will then pass from
the lower to the upper side of the piston, equalizing the pressure on both sides
of the piston, when the hammer will descend with a velocity due to gravitation
alone; when it has descended the valve will again be reversed, the equilibrium
ports closed, and the steam or other fluid on the under side of the piston will
be retained in anticipation of the next stroke, whilst that on the upper side
will be exhausted at the same time that the steam or other fluid is admitted
to the under side for again raising the hammer.
If the steam or other fluid is to be admitted to the upper side of the piston
for accelerating the downward stroke the action of the valve is as follows:-
The valve will be moved in a downward direction, admitting the.steam or
other fluid to the under side of the piston, and when the hammer has ascended
sufficiently high. the valve may be moved in the contrary.direction till the
equilibrium ports in the valve are opposite the ports in the casing, when the
pressure in the cylinder will be equalized above and below the piston; this

page_text: so far is precisely the same as for single-acting, but instead of the valve now
being reversed it will continue moving in the same direction till the ports are
open to the steam or other fluid at the top side of the piston and to the
exhaust pipe on the bottom side; the hammer will then descend with a
velocity due to its own gravity and the pressure of steam or other fluid on the
top side of the piston. After it has descended the valve will be again moved
downward and the equilibrium passage and ports opened, when a portion of
the steam or other fluid will pass from the top to the lower side of the piston,
and will be retained there until the next charging, while that on the top side
will at same time be exhausted.
Instead of piston valves, slide valves or conical or cylindrical valves may be
used, to the latter of which I give a partial rotary motion, and provide the
necessary passages for effecting the objects desired.
Two or more single valves may be adapted and applied to effect the same
purposes as the one combined valve above referred to.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said David Davy in the Great Seal Patent, Office on the 31st
December 1867.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
DAVY, of Sheffield, in the County of York, Engineer, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of July, in the year of our Lord One
thousand eight hundred-and sixty-seven, in the thirty-first year of Her reign,
did, for Herself, Her heirs and successors, give and grant unto me, the
said David Davy, Her special licence that I, the said David Davy,. niy'
executors, administrators, and assigns, or such others as' I, the said David
Davy, 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 STEAM AND OTHER
HAMMERS WHEREBY TO EFFECT ECONOMY IN THE USE OF THE STEAM OR OTHER FLUID
ACTUATING SAID HAMMERS," upon the condition (amongst others) that I, the
said David Davy, 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

page_text: 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 David Davy, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following
statement, reference being had to the Sheet of Drawings hereunto annexed,
and to the letters and figures marked thereon (that is to say) :-
My Invention consists in a means berein-after described by which an
economy of steam or other elastic fluid employed for actuating said hammers
may be effected above that accomplished by the ordinary system of working
such hammers, and whereby much expenditure of steam or other fluid is in
a manner avoided when the hammer is working with a varying length of
stroke.
The methods by which I propose to accomplish these results are as
follows:-
The cylinder and piston may be constructed in any of the variety of forms
usually adopted, but the distribution of steam or other fluid is effected as
follows: I-propose using a piston valve with two or more pistons upon it, but,
for example, I will describe the one with two pistons. The steam or other
fluid is admitted into the valve chest between the two pistons, and the exhaust
steam passes into the valve chest from the cylinder at each end of the valve
and thence into the exhaust pipe. The pistons of the valve are hollow, and
around their circumference are ports corresponding with and opposite or
nearly so with other ports in the valve casing; by this means when the valve
is in a certain position a communication is established between the top and bottom
of the cylinder. The valve is made to reciprocate in the casing either by hand
or by a self-acting motion. The ports in the valve casing answer both for the
ingress and egress of the steam, and for passing it from the top to the bottom
of the hammer cylinder, or vice versa, but the ports around the circumference
of the valve pistons and the passage connecting them together are only used as
a communication for equalizing the pressure of the steam in the top and
bottom of the hammer cylinder.
The mode of operation is as follows:-Supposing the hammer is to be
raised the valve is moved in a downward direction, admitting the steam or
other fluid to the under side of the piston, and when it has ascended sufficiently
high the valve is moved in the opposite direction till the equilibrium ports in
the valve are opposite the ports in the casing; a portion of the steam or other
fluid which has raised the hanımer will then pass from the lower to the upper

page_text: side of the piston, equalizing the pressure on both sides of the same, when the
hammer will descend with a velocity due to gravitation alone. When it has
descended the valve is again reversed, the equilibrium ports closed, and the
steam or other fluid on the under side of the piston will be retained in anticipa-
tion of the next stroke, whilst that on the upper side will be exhausted; the
steam or other fluid is then admitted for again raising the hammer.
If the steam or other fluid is to be admitted to the upper side of the piston
for accelerating the downward stroke the action of the valve is as follows:-
The valve is moved in a downward direction, admitting the steam or other
fluid to the under side of the piston, and when the hammer has ascended
sufficiently high the valve is moved in the contrary direction till the equili-
brium ports in the valve are opposite the ports in the casing, when the pressure
in the cylinder will be equalized above and below the piston; this so far is
precisely the same as for single acting, but instead of the valve being now
reversed it will continue moving in the same direction till the ports are open
to the steam or other fluid at the top side of the piston, and to the exhaust
pipe on the bottom side; the hammer will then descend with a velocity due to
its own gravity and the pressure of the steam or other fluid on. the top side of
the piston; after it has descended the valve is again moved downward, and the
equilibrium passage and ports opened, when a portion of the steam or other
fluid will pass from the top to the lower side of the piston, and will be retained>
there until the next charging takes place, when that on the top side will be
exhausted.
:
.
}
Instead of piston valves, slide valves or conical or cylindrical valves may be
used, to the latter of which I give a partial rotary motion, and provide the
necessary passages for effecting the desired object.
Two or more single valves may also be adapted and applied to effect the
same purposes as the one combined valve above referred to.
DESCRIPTION OF DRAWINGS.
My improvements are illustrated in the accompanying Drawings, Figure 1
of which is a vertical section of a hammer cylinder with the valve box and
valve; Figure 2 is a horizontal section through the line A, B, of Figure 1';
Figure 3 is a similar section through the line C, D; and Figure 4 is a section
of the valve box taken at. right angles to Figure 1 with an elevation of the
valve.
'
The steam or other fluid is admitted into the valve casing at a, and fills the
annular space b, it will be seen that when the valve c is moved in a downward

page_text: direction the steam or other fluid will pass from the annular space b through
the port d to the under side of the piston e, thereby raising the hammer attached
to the rod of said piston; and if when the hammer has ascended sufficiently
high the motion of the valve be reversed and brought to the position shown
in the Drawing it will be seen that a communication is established between
the bottom and top of the cylinder, and a portion of the steam or other fluid
will pass from the under side to the top side of the piston e through the ports
d and f in the cylinder by means of the equilibrium ports 9 in the valve, the
pressure on the under side and top side of the piston e will then become
equalized and the hammer will fall with a velocity due to gravitation or work
what is usually termed single acting; if it is desired to work double acting,
that is, with steam on the top side of the hammer piston e at the initial pressure,
it will be necessary to raise the valve c till the port f in the cylinder is open
to the space b around the valve and the port d is open to the exhaust pipe h;
the hammer will then fall with a velocity due to its own gravity, and the
pressure of steam or other fluid on the top side of the piston. When it is:
desired to again raise the hammer the valve c will be lowered in the casing
till the port d in the cylinder is open to the space 6 around the valve allowing
the steam or other fluid to again pass to the under side of the piston e; but.
before this can take place it will be seen that in lowering the valve the
equilibrium ports g in the valve will pass over the ports f and d in the cylinder,
during which process a part of the steam which has acted on the top side of
the piston e in the descent of the hammer will pass through the port f in the
cylinder and the equilibrium ports 9 in the valve to the under side of the
pistone through port d. is the valve spindle working through a stuffing
box and connected to handing levers or a self-acting motion in the ordinary
manner.
Figures 5 and 6 represent vertical and horizontal sections of a modification
of the valves shown in Figures 1, 2, 3, and 4. The steam or other fluid in place
of being admitted to a space round the valve is admitted to the top and
bottom side of the valve, and the exhaust port is in the middle...
a is the steam branch; b, b, b, b, the equilibrium ports serving both for the
exhaust and for passing the steam from the bottom to top of cylinder, or vice
versa; c, the exhaust port; d and e, the ports leading to the under side and
top side of the hammer piston; f, the valve spindle.
Figures 7, 8, 9, and 10 represent a cylindrical valve, but it may if preferred
be turned slightly conical, in which case I propose making the valve spindle of
the same area as the difference in the areas of the two ends of the valve so as:

page_text: to prevent the steam or other fluid from jamming the valve tight in the casing;
these valves have a partial rotary motion imparted to them, the mode of
operation being precisely the same as the reciprocating piston valves already
described.
a is the steam branch; b, b, b, b, the equilibrium ports; c, the exhaust port;
d and e, the ports leading to the under side and top side of the hammer piston;
f, the valve spindle.
Figures 11 and 12 represent a vertical and horizontal section of a slide
valve adapted to these improvements. a is the steam pipe; b, the equilibrium
port; c, the exhaust; d and e the ports leading to the bottom and top side of
the hammer piston; f, the valve spindle.
Figures 13, 14, and 15 further represent respectively a horizontal and
vertical section and front view with cover removed of an equilibrium slide
valve arranged according to my improvements. a is the steam pipe; b, answers
both for the equilibrium and exhaust passage; c, the exhaust branch; d and e,
the ports leading to the bottom and top side of the hammer piston; f, the
valve spindle.
Figure 16 represents a vertical section, and Figure 16* a horizontal
section, of a combination of two valves for effecting the same object as the
single valves already described. a, a, is a double piston valve; b, is the
equilibrium valve; c, c, the equilibrium ports; d, the steam branch; e, the
exhaust branch; f and g, the ports leading to the bottom and top side of the
hammer piston; h and i, the valve spindles, both connected by a bell-crank
lever or otherwise to the same hand levers or self-acting motions.
Figure 17 is a vertical section, and Figure 17* a horizontal section, of
another modification of the slide and piston valves already described. The steam
or other fluid is admitted to the ends of the valve at a, a; b, b, the equilibrium
passage; c, c, the exhaust passage; d, the valve spindle; e and f, the ports
leading to the bottom and top side of the hammer piston.
Having described the nature of my Invention, and the manner of perform-
ing the same, I declare that what I claim as new and of my Invention for
obtaining economy in the working of steam and other hammers to be secured
by the herein-before in part recited Letters Patent is,―
First, passing a portion of the steam or other fluid which has raised the
hammer to the top side of the hammer piston, and passing a portion of the
steam or other fluid which has acted on the top side of the hammer piston in
the descent of the hammer to the under side of the said piston, in each case
before the steam or other fluid is admitted into the cylinder at the initial
pressure.

page_text: Secondly, I claim the several arrangements of valves applied as and for the
purposes described and as represented in the accompanying Drawings.
In witness whereof, I, the said David Davy, have hereunto set my hand
and seal, this Twenty-third day of December, in the year of our
Lord One thousand eight hundred and sixty-seven.
DAVID DAVY. (L.S.)