IMPROVEMENTS IN STEAM HAMMERS
Year: 1863

page_text: LETTERS PATENT to David Davy, jun., of Sheffield, in the County of
York, Engineer, for the Invention of "IMPROVEMENTS IN STEAM
HAMMERS."
Sealed the 5th February 1864, and dated the 3rd November 1863.
PROVISIONAL SPECIFICATION left by the said David Davy at the
Office of the. Commissioners of Patents, with his Petition, on the
3rd November 1863.
I, DAVID DAVY, jun'., of Sheffield, in the County of York, Engineer, do
hereby declare the nature of the said Invention for "IMPROVEMENTS IN STEAM
HAMMERS," to be as follows:-
This Invention relates to certain improvements in double and single acting
steam hammers.
I employ a small supplementary cylinder fixed upon one of the hammer
frames or in any other convenient position, through the piston of which the
motion is given to the slide or valve of the hammer cylinder. This is
accomplished by planing in or bolting or otherwise fastening upon the
hammer tup an incline a, Fig. 1, which gives motion through the bell-crank
lever b to the valve c of the supplementary cylinder, which admits the steami
alternately above and below the piston d of the same, and this piston being in
connection with the slide or valve of the hammer cylinder, either direct as

page_text: shown in Drawing, or otherwise, gives the required motion thereto. It
will be seen that when the supplementary cylinder has been charged with
steam on either side of its piston, and the valve has travelled the required
distance (in all cases the full length of the stroke of the valve) for freely
admitting and exhausting the steam from the hammer cylinder, the valve will
remain in its position until the supplementary cylinder has been charged with
steam on the contrary side of the piston, thereby allowing the steam free
ingress and egress to and from the hammer cylinder, and the full effect of the
blow obtained, without subjecting the motion to any blow. or jerk from the
hammer tup. The length of stroke of the hammer is regulated, and all
varieties of blows obtained at will, by fixing on the back of the valve c
of the before-mentioned supplementary cylinder two adjustable plates e and f,
cast hollow on their under side to allow the exhaust steam to pass from the
said cylinder up the pipe g to the main exhaust pipe. The valve c of the
supplementary cylinder is cast with three ports, the two outside ports for the
admission of steam into the cylinder and the middle for the exhaust steam.
It will be seen that on the two end ports of the valve working beyond the
adjustable plates before named, that the cylinder will be charged with steam
at either end, and that by raising or depressing either of the back plates
separately by means of the two hand levers h and i, the supplementary'
cylinder may be charged with steam earlier or later in proportion to the
length of stroke the hammer is required to work. The ports of the supple-
mentary cylinder are cast bell-mouthed, so as always to allow the steam from
the same to escape freely, no matter in what position the adjustable plates are
fixed. is a buffer or cushion, of india-rubber or other elastic material, to
prevent the valve travelling farther than is necessary. It will be seen that in
large hammers which are not required to be self-acting, the valve of the
supplementary cylinder might be constructed on the ordinary slide or piston
principle, and be connected to an ordinary handing lever.
The supple-
mentary cylinder with its parts may be fitted to steam hammers of any con-
struction, and be in connection with valves either on the ordinary slide or
piston principle. Fig. 2 shows a sectional plan of the supplementary cylinder.
Fig. 3 represents a sectional elevation of a piston valve for a steam hammer
with five pistons upon it, the middle piston being of a smaller area than the
two pistons immediately above and below it. The small slide a is attached by
means of rods or otherwise to the bell-crank lever herein-before mentioned,
and from which it receives its motion. It will be seen that as the slide a
moves up or down the spaces between the pistons b, c, and b, d, are alternately
charged with steam, and the two pistons c and d being of greater area than

page_text: the piston b, there is necessarily a greater pressure upon them, which gives
the required motion to the valve, which is prevented from travelling too far
by its spindle being carried through the top of the valve box, the end of
which is provided with a small piston which works on a cushion or buffer of
india-rubber or other elastic material as shown at e. The spaces between
the two pistons is allowed to be quickly or slowly charged in proportion to the
length of stroke of the hammer, by opening or closing either of the two
cocks ƒ and g by means of hand levers, by which operation the length of stroke
and variety of blow is regulated; or in lieu of this mode of regulating the
stroke, the valve with adjustable backs as applied to the auxiliary cylinder
herein-before described may also be applied in this case; h is the stop or
regulating valve, and the main valve of the hammer is proposed to be made.
hollow with a number of holes through its sides, as shown in Drawing, for the
purpose of allowing the steam to pass from the top part of the valve chest to
the lower part; or it may be an ordinary spindle with each piston cottered or
otherwise fastened upon it separately, and with two admission valves, one to
admit the steam to the top side of the valve chest and the other to admit the
steam to the lower side of the valve chest. It will be seen that by entirely
closing the valve which admits the steam to the top part of the valve box
the hammer will work single acting (viz.), with steam on the
piston only. This will be better understood by referring to Fig. 4, which
shows a piston valve with three pistons upon it, i, k, and I, which receives its
motion direct from the bell-crank lever herein-before described. The admis-
sion of steain to the top and bottom side of the hammer piston is regulated
by opening or closing the two valves m and n, which are adjusted by hand
levers in the ordinary manner, and also serve as stop valves. If the valve m
which admits the steam to the top part of the valve box be entirely closed,
the hammer will work single acting (viz.), with steam on the under side of
piston only.
under side of
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed.
by the said David Davy in the Great Seal Patent Office on the 30th
April 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DAVID
DAVY, junior, of Sheffield, in the County of York, Engineer, send greeting.
WHEREAS IIer most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Third day of November, in the year of our

page_text: Lord One thousand eight hundred and sixty-three, in the twenty-seventh
year of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said David Davy, junior, Her special licence that I, the
said David Davy, junior, my executors, administrators, and assigns, or
such others as I, the said David Davy, junior, my executors, adminis-
trators, 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 I, the said David Davy, junior, 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 David Davy, junior, do hereby
declare the nature of my said Invention, and in what manner the same is
to be performed, to be particularly described and ascertained in and by the
following statement, reference being had to the four Sheets of Drawings
hereunto annexed, and to the lotters and figures marked thereon (that is.
to say) -
My Invention relates to improvements in valve apparatus of steam hammers,
whereby the working of the hammer is easily regulated, and a freer and better
action thereof induced than is obtained by the ordinary mode of working.
The motion is not subject to any blow or jerk, and is of much simpler con-
struction than the ordinary motion, therefore much less liable to get out of,
order. The valve of the hammer cylinder is actuated by an auxiliary steam
cylinder, the valves of which may be small, and therefore work easily as
compared with the slide valves of hammer cylinders. The valve apparatus is
so arranged that the valve of the hammer cylinder always travels the same
distance, whether the hammer is working the whole length of its stroke, or only
making short strokes, and remains at rest for a considérable period of time
at each end of its course; by this arrangement ample time is always provided
for the ingress and escape of the steam to and from the cylinder, thereby
ensuring the full and uninterrupted effect of the blow of the hammer. For
regulating the length of the stroke of the hammer I provide the valve of the
auxiliary cylinder with adjustable back plates, moving which up and down
:

page_text: permits the ports to open sooner or later in the stroke of the valve, thus
admitting the steam sooner or later into auxiliary cylinder, and therefore
moving its piston, and with it the main valve, at an early or later period
of the stroke. The valve itself is simply a flat plate with slots or ports.
through it, and I provide two of the back plates before mentioned, which are
half the width of the valve, placed side by side on it, and so cover its entire
breadth. These back plates have hollow channels cut in them for the passage
of the exhaust steam in manner of an ordinary slide valve, and are each
provided with considerable lap at one end, the lap of the one being at the
opposite end to that of the other. This lap of the one end of the back plates is
such that the port in the valve is never uncovered at all by the broad lapping
part, while at the other end of the back plate where the valve uncovers itself,
there is little or no lap; consequently as soon as the steam is cut off, say, at
the upper end, it opens to the exhaust at same end, but steam is not admitted
to the other end of the auxiliary cylinder until the valve port passes from
under the lower end of the other back plate, which like the upper end of the
former one has little or no lap. From this it will be seen that by moving the
back plates so that the ends where the steam is admitted are brought in
their closest proximity, the said slide moves a short distance only in admitting
the steam to opposite ends of the auxiliary cylinder, and as the slide is moved
directly from the hammer a short stroke only will be imparted to it, whereas
when those ends of the back plates are moved further apart the slide will
move further before admitting steam to act on the auxiliary cylinder piston,
and therefore produce a longer stroke of the hammer in proportion to the
extent covered by the back plates, as it will be obvious the valve must move
a greater distance before the inlet ports will be uncovered. Whether the
stroke of the hammer be long or short, the piston of the auxiliary cylinder
moves the full extent of its stroke, and consequently moves the valve of the
main cylinder the full length of its stroke, either for a long or short stroke of
its piston and hammer, as before mentioned.
The auxiliary cylinder, instead of being a small separato cylinder connected
by a rod to the slide valve of the main cylinder, may be formed in one and the
same piece with main slide valve, for which purpose I make it in the form
of a piston valve, which as well understood consists of pistons fixed on a rod
or stem working in a cylinder furnished with suitable steam ports. To
combine the auxiliary cylinder with this I add other pistons to the same rod
or stem, and by the difference in the area of said pistons produce the desired
motion of the main valve by the admission of the steam to act thereon, as will
be herein-after described with reference to the Drawings.

page_text: Fig. 1 represents a front elevation of a steam hammer fitted with valve
apparatus according to my Invention, which is shown in section. The main
valve a is a piston valve, and is represented as being worked directly from a
the
small auxiliary cylinder b, the pistons being in fact on the same rod e;
small cylinder bis bolted to the hammer frame, the piston d is worked by
steam admitted to the ports e and f, like an ordinary steam cylinder, but
instead of the ordinary slide valve for regulating the admission of steam, I
employ a slide plate or valve g, having through ports or passages, which
passages are covered by the back plates h and i before mentioned, which will
be best seen in the horizontal section, Fig. 2, of the auxiliary cylinder and its
valves, and in Fig. 3 a lateral section of the valve chest through the stuffing
boxes of rods j, j. The valve g is worked direct from the hammer tup by a
cranked lever k mounted on a fixed fulcrum at 1, the one end of said lever
being linked to rod m of valve g, while the other end has a pin which carries
a sliding block fitted to and sliding in the groove p placed in or bolted to
the hammer tup. The back plates h and i are connected by rods j, j, passing
through stuffing boxes with the hand levers 9 and r, by means of which their
position can be altered at will; after having been adjusted, the hand levers are
fixed by thumb-screws s to the arcs t. It will be observed that one of the
plates h has considerable lap at the lower end, while the other has like lap at
the upper end, and so as to prevent the admission of steam to the ports in the
valve g; steam is admitted by the pipe n from the main valve to the steam
chest o, enclosing the valve g, and back plates h and i, which presses up to
the valve g, and the whole up to the slide face; u is the eduction passage
of the steam, which communicates with the eduction of the main cylinder by
pipe v; w, w, are cushions of india-rubber. or other elastic material, against
which the enlargement on the valve rod strikes in its up-and-down strokes,
and limiting the extent of motion; this is however always the same, being
sufficient to fully open the ports of the main steam slide and cylinder.
It will be unnecessary to give any detailed explanation of the other parts of
the steam hammer, such machinery being well understood. The action of the
apparatus is as follows:-Supposing the stroke of the hammer desired be of the
full length, the back plate h is set at its highest position and back plate i at its
lowest position, the former controlling the admission of steam above the
piston d, and the latter the steam entering below that piston; from this it will
be readily seen that the valve 9 must move to the extreme or nearly the
extreme length of its stroke before the ports in g admitting steam below the

page_text: piston d will emerge from under the back plate i, and that, therefore, the
hammer tup and groove p will rise to its full extent, and the latter act
throughout its whole length on lever k, before change of motion will be
effected; but immediately the desired point is arrived at, the rise of piston d,
and with it the change of the main valve a, will be instantly produced, as before
mentioned; the steam from under the hammer cylinder will have a full and
instantaneous eduction, and if the hammer be double acting, as represented in
Fig. 1, the piston of the main cylinder will be simultaneously subjected to
the full force of the steam on its upper surface, and so augment the force of
the blow. By the fall of the hammer the slide 9 will be again raised, the
lower part thereon being withdrawn under the back plate i, and at once
admitting free eduction from the lower side of the auxiliary cylinder. This
eduction will not, however, cause the main slide a to descend, which descent
will not take place until the upper port in 9 has been projected upwards
beyond the back plate h, and is opened to the steam in the valve case, which
is admitted above the piston d; this takes place simultaneously with the blow
of the hammer, and piston d at once descends again and moves the main slide
so as to admit steam below the piston of the hammer cylinder, and so raise
the hammer as before, and so on. The position of back plate h necessarily
depends somewhat on the substance between the hammer and the anvil, in
other words, according to the point to which the hammer falls. The ports in
the face of the slide are funnel-mouthed, as seen in the sectional part, Fig. 1,
in order that the steam may always have free egress so soon as the extreme
ports in slide 9 pass under their respective back plates h and i, the communi-
cation being effected with the exhaust passage u by the back plates h and i,
embracing one of the extreme ports 1, 1, in valve g, and the middle port or
opening 2 in g, which is always open to u. For shorter strokes of the hammer
the positions of the back plates h and i are changed, that is to say, the plate i
is raised so as to admit the steam on the under side of piston d with less
stroke of the valve g, say, at half-stroke, and if so the steam will be admitted
under piston d, at half the rise of the hammer, raising piston d and slide a, and
at once cutting off the admission of steam to the under side of hammer
cylinder, opening the eduction, and reversing the pressure of the steam, as
before described. As before mentioned the position of back plate h depends
somewhat on the thickness of material on the anvil on which the hammer
falls. In large hammers, which are not required to be self-acting, the valve
of the supplementary cylinder may be constructed on the principle of the
ordinary slide or piston, and be connected and worked with an ordinary hand
lever.

page_text: Fig. 4 represents a vertical section of the piston valves of the main or
hammer cylinder of a steam hammer to be actuated by the auxiliary cylinder,
as herein-before described, but in which the steam may be either admitted to
both sides of the piston or to one side only, and thus render the hammer
either single or double acting at pleasure. The only difference in this slide
from that represented at Fig. 1, is, that a third piston y is fixed on the valve
rod c, thus dividing the space of the valve chest between the two extreme
pistons z, z, into two compartments, each of which is provided with a steam
inlet (3, 4), the admision of steam to which is regulated by suitable stop
valves 5, 6, these are opened and closed by suitable hand levers, as may be
required. When steam is admitted by valve 6 to space 4, steam will enter
below the hammer piston, and it will work single-acting. When it is desired
to work the hammer double-acting, it is simply necessary to open the valve 5
in addition to the valve 6, when steam will be admitted to the space 3, and it
will work double-acting. The steam so entering will be admitted alternately
above and below the hammer piston by the pistons z, z, opening alternately
the cylinder ports 7, 7, to the steam spaces 3, 4, and the spaces 8, 8, leading
to the eduction, as well understood. In other respects the working of the
hammer by this arrangement of valve is precisely as before described with
reference to Fig. 1.
Fig. 5 represents a Drawing of an arrangement of a piston valve for a
steam hammer, in which the auxiliary cylinder is combined with the valve of
the main cylinder, and is in one and the same chamber, being in fact of a
piece with it, with five pistons upon it, the middle piston being of a smaller
area than the two pistons immediately above and below it. The small slide X
is attached by means of rods or otherwise to the bell-crank lever, receiving
motion from the hammer tup as herein-before described, from which the
slide X derives its motion. It will be seen that as the slide X moves up or
down the spaces between the pistons F, D, and F, E, are alternately charged
with steam, and the two pistons D and E being of greater area than the
piston F, there is consequently a greater pressure upon them, which gives the
required motion to the valve. The valve is prevented from travelling too far
by its spindle being carried through the top of the valve box, the end of which
is provided with a small piston, which works on a cushion or buffers of india-
rubber or other elastic material, as shown at G. The spaces between the two
pistons are allowed to be quickly or slowly charged, in proportion to the length
of stroke of the hammer, by opening or closing either of the two cocks H
and I by means of hand levers, by which operation the length of stroke and
variety of blow is regulated. Or in lieu of this mode of regulating the stroke,

page_text: the valve, with adjustable backs as applied to the auxiliary cylinder herein-
before described, may also be applied in this case. K is the stop or regu-
lating valve, and the main valve of the hammer has a hollow trunk with a
number of holes through its sides, as shown in the Drawing, for the purpose
of allowing the steam to pass from the top part of the valve chest to the lower
part 9, 9, being the steam spaces between the extreme upper and lower pistons:
B and C, and the intermediate pistons D and E. Instead of a hollow stem or:
trunk, an. ordinary spindle, with each piston cottered or otherwise fixed upon
it, may be used in conjunction with two admission valves, one to admit the
steam to the upper part of the valve chest, and the other to admit the steam.
to the lower side of the valve chest, which will have the further advantage of.
enabling the hammer to be worked single or double acting, as before described,
as by entirely closing the valve which admits the steam to the top part of the
valve box, the hammer will work single-acting (that is to say). with steam on
the under side of the piston only.
Fig. 6 represents a front elevation of a steam hammer, having valve appa-
ratus arranged according to my Invention, in which the main. slide valve is.
actuated by an auxiliary steam cylinder arranged and combined in same:
cylinder (as illustrated in Fig. 5), such auxiliary cylinder being worked by
the arrangement of slide valve with back plates, first herein-before described
with reference to Figs. 1, 2, and 3. Fig. 7 is an end elevation of Fig. 6.
Fig. 8 represents a vertical section through the lines N, O, on Fig. 6, showing.
the central vertical section of the compound pistons and piston valves, with the
arrangement of the slide valve and back plates of the auxiliary cylinders also
in section. Fig. 9 is a lateral vertical section of the main or hammer.
cylinder, piston valve cylinder, and the eduction passages therefrom. Fig. 10
shows a borizontal section on line P, Q; Fig. 11, a like section on line R, S;
and Fig. 12, a like section on T, U, all in Fig. 9. Fig. 13 represents a
horizontal section of the hammer cylinder and valve cylinder on the line V, W,
Fig. 6, showing the eduction passage from the auxiliary cylinder; while
Fig. 14 represents a horizontal section on line X, Y, Fig. 9, showing the
upper eduction passage from the piston valve. Fig. 15 represents a detached
view (plan) of the hand levers, partly in section, through their fixed fulcrum
or axis.
In this hammer, represented in Figs. 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15,
the arrangement of the auxiliary cylinder and piston valves of the main
cylinder is, as before mentioned, the same as that described with reference to
Fig. 5, B, C, D, E, and F, being the fixed pistons in cylinder J, J, constituting
the main valves and auxiliary cylinder, and 9, 9, the actuating steam spaces of

page_text: such auxiliary cylinder as before, the action of which, together with that of
the valves, it will be unnecessary to further explain. Instead of the slide
valve X of the actuating cylinder Fig. 5, I have substituted in this. the slotted
plate valve g of Figs. 1, 2, and 3, together with the back plates h and i, con-
nected with the hand levers 7 and r, the operation of the whole of which is the
same as described with reference to those Figures, and therefore need not be
again repeated. The lever k receiving motion from the hammer tup and
transmitting it to the valve g, is in this case of the second instead of the first
order of levers, which is necessary (other parts being the same) to reverse the
action of the auxiliary cylinder, as in this case the admission of steam to the
upper part of the auxiliary cylinder raises the main valve and admits steam
below the hammer piston, whereas in the former example the auxiliary piston
was depressed with like effect on the hammer piston. All other parts of
the action are the same as before, the same letters of reference where the
same parts recur being inserted, as will be readily traced on the Drawing, and
need not be recapitulated. The red arrows show the ingress of steam to the
auxiliary and main cylinders, while the black arrows show the eduction from
the main cylinder, and the blue ones that from the auxiliary cylinder, which
will render the general construction easily understood. If it is desired to
make this hammer single-acting, it is simply necessary to introduce a stop
valve in the passage from the steam chest. to the upper part of the cylinder,
as seen dotted at L, this valve being closed by suitable hand gear, when
the hammer works single-acting; Z is the stop valve connected with hand
lever Z' by rod Z", as usual in steam hammers. The arrangement of slide
valve g and adjustable back plates h and i may be applied to the hammer
cylinder to control directly the ingress and egress of the steam thereto, that is
to say, without the intervention of the auxiliary cylinder, which will be readily
understood without further description or Drawings. Instead of using piston
valves as the main valves of steam hammers, as herein-before described and
represented, an ordinary slide valve may be employed and actuated by an
auxiliary cylinder furnished with valve apparatus according to my Invention,
as represented and described with reference to Fig. 1 of the Drawings here-
unto annexed.
Having described the nature of my Invention and the manner of per-
forming the same, I declare that what I claim as my Invention, to be protected
by the herein-before in part recited Letters Patent, is,-
First, the slide valve g in combination with the adjustable back plates
h and i, for working the auxiliary cylinder actuating the main valves of a
steam hanımer, all as herein-before described. I also claim the said arrange

page_text: ment of slide valve g and back plates h, i, applied directly as the valve
apparatus of the hammer cylinder instead of to the auxiliary cylinder, as
described.
Secondly, I claim the arrangement and application of an auxiliary steam
cylinder combined with and working the valves of the hammer cylinder, as
represented in Figs. 5, 6, and 7 of the Drawings, & herein-before described.
Thirdly, I claim the arrangement of the valve g and back plates h and i,
in combination with the piston valves of the main cylinder, as herein-before
described and represented in Figs. 6, 7, 8, 9, 10, 11, 12, 13, 14, and 15 of
the Drawings hereunto annexed.
Lastly, I claim the application of any of the above arrangements, either
separately or conjointly, as a means of actuating the valves of steam hammers,
as herein-before described.
In witness whereof, I, the said David Davy, have hereunto set my hand
and seal, this Twenty-eighth day of April, in the year of our Lord
One thousand eight hundred and sixty-four.
זזז!
DIY
DAVID DAVY. (L.D.)