IMPROVEMENTS IN ACTUATING THE VALVES OF STEAM HAMMERS AND IN THE CONSTRUCTION OF SUCH VALVES
Year: 1878

page_text: 837,
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LETTERS PATENT to Charles Davy, of Sheffield, in the County of York, for
the Invention of "IMPROVEMENTS IN ACTUATING THE VALVES OF STEAM
HAMMERS AND IN THE CONSTRUCTION OF SUCH VALVES,"
Sealed the 4th October 1878, and dated the 15th April 1878.
PROVISIONAL SPECIFICATION left by the said Charles Davy at the Office
of the Commissioners of Patents on the 15th April 1878.
CHARLES DAVY, of Sheffield, in the County of York. "IMPROVEMENTS IN
ACTUATING THE VALVES OF STEAM HAMMERS AND IN THE CONSTRUCTION OF SUCH.
VALVES."
My Invention relates to the valves for controlling the admission and exhaustion
of steam to and from the cylinders of steam hammers, and to the method of:
actuating such valves, the object of the Invention being to enable the steam to be.
worked expansively, and therefore economically, and to avoid compression or back.
pressure.
Hitherto the valves of steam hammers when worked automatically have been
actuated entirely by mechanism in connection with and operated by the hammer
head or tup, and it has not been possible in self-acting stean hammers to employ.
valves having more lap on the steam than on the exhaust side. .
Now according to my Invention I employ a valve or valves having lap on the
steam side, as in the case of an ordinary steam engine, but instead of depending.
entirely upon the motion of the hammer head or tup to actuate the valve or valves,
I employ the conjoint action of the hammer head or tup and of a revolving shaft
driven from a source of power entirely independent of the hammer, and acting in,
such a way the one in relation to the other that a compound action is given to the
valve where a single valve is employed, or where two valves are employed a.
differential motion is imparted to the two valves, whereby the steam is worked
expansively, precisely as in an ordinary steam engine.
In carrying out my Invention I employ an arrangement of levers worked by an
inclined plane fixed to the hammer head or tup, or by any means hitherto used for.
imparting motion to the valve by the action of the hammer head or tup; and when
[Povice G11
:
"

page_text: a single valve is used I propose, according to one arrangement, to mount the fulcrum
of one of the said levers on a lever operated by an eccentric or crank on a revolving
shaft driven from any independent source of power, or I may otherwise combine the
action of the hammer head or trip and of the revolving shaft so as to produce the
compound motion desired.
In order to obtain an equivalent effect I may employ two valves, the one inside
or on the back of the other, and actuated independently, the one by the usual
mechanism from the hammer head, and the other by the crank or eccentric above
mentioned, so as to impart a differential motion to the two valves.
SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Charles Davy in the Great Seal Patent Office on the 15th October
1878.
CHARLES DAVY, of Sheffield, in the County of York. "IMPROVEMENTS IN
ACTUATING THE VALVES OF STEAM HAMMERS AND IN THE CONSTRUCTION OF SUCH
VALVES."
£ My Invention reates to the valves for controlling the admission and exhaustion
of steam to and from the cylinders of steam hammers, and to the method of
actuating such valves, the object of the Invention being to enable the steam to be
worked expansively, and therefore economically, and to avoid compression or back
pressure.
Hitherto the valves of steam hammers when worked automatically have been
actuated entirely by mechanism in connection with and operated by the hammer
head or tup, and it has not been possible in self-acting steam hammers to employ
valves having more lap on the steam than on the exhaust side.
Many attempts have been made to work the steam expansively in automatic
hammers by modifying the mechanism in such a way that the valves, although still
entirely actuated by the hammer head instead of making a continuous stroke, are
arrested immediately on cutting off the admission of steam, so as, instead of opening
at once to the exhaust as usual, to remain closed for a sufficient length of time to
enable the steam to work expansively; but as in steam hammers both ports are
necessarily closed at the same instant, the result of attempting to work the steam
expansively in the way above described has been to cause back pressure or com-
pression on the other side of the piston, and little or no advantage has been
gained.
Now according to my Invention I employ a valve or valves having lap on the
steam side, as in the case of an ordinary steam engine, but instead of depending
entirely upon the motion of the hammer head or tup to actuate the valve or valves,
I employ the conjoint action of the hammer head or tup and of a revolving shaft
driven from a source of power entirely independent of the hammer, and acting in
such a way the one in relation to the other that a compound action is given to the
valve where a single valve is employed, or where two valves are employed a

page_text: differential motion is imparted to the two valves, whereby the steam is worked
expansively, precisely as in an ordinary steam engine.
In carrying out my Invention I employ an arrangement of levers worked by an
inclined plane fixed to the hammer head or tup, or by any means hitherto used for
imparting motion to the valve by the action of the hammer head or tup; and when
a single valve is used I propose, according to one arrangement, to mount the fulcrum
of one of the said levers on a lever operated by an eccentric or crank on a revolving
shaft driven from any independent source of power, or I may otherwise combine the
action of the hammer head or tup and of the revolving shaft so as to produce the
compound motion desired.
In order to obtain an equivalent effect I may employ two valves, the one insido
or on the back of the other, and actuated independently, the one by the usual
mechanisin from the hammer head, and the other by the crank or eccentric above
imentioned, so as to impart a differential motion to the two valves."
.
differential motion is imparted to the two valves, whereby the steam is worked
expansively, precisely as in an ordinary steam engine.
In carrying out my Invention I employ an arrangement of levers worked by an
inclined plane fixed to the hammer head or tup, or by any means hitherto used for
imparting motion to the valve by the action of the hammer head or tup; and when
a single valve is used I propose, according to one arrangement, to mount the fulcrum
of one of the said levers on a lever operated by an eccentric or crank on a revolving
shaft driven from any independent source of power, or I may otherwise combine the
action of the hammer head or tup and of the revolving shaft so as to produce the
compound motion desired.
In order to obtain an equivalent effect I may employ two valves, the one insido
or on the back of the other, and actuated independently, the one by the usual
mechanisin from the hammer head, and the other by the crank or eccentric abovo
inentioned, so as to impart a differential motion to the two valves."
DESCRIPTION OF DRAWINGS.
Figure 1 is an elevation of part of a steam hammer with the improved valve gear
of my Invention, the valve chest being in section.
Figure 2 is an elevation at right angles to Figure 1 of the shaft and levers by
which the valves are controlled.
Figure 3 is a plan of same, the side standard of the hammer framing being in
section.
A is the hammer head or tup represented in its lowest position; it has an inclined
rib a fitted to work through a slide or block B, jointed at b to a bell-crank lever C
working on a pivot c, to which lever is also jointed at d one end of a connecting
rod D, jointed at its other end to the valve rod E, all much as usual, for working
the valve from the incline a on the tup A.
Instead however of the fulcrum c being stationary on the hammer framing, it is
carried by a lever arm F fixed on a rock shaft f mounted in the hammer framing,
and having fixed to its other end another lever arm F', which is worked by a
crank h on a shaft H through a connecting rod G jointed adjustably to lever F',.
which is slotted for the purpose. The shaft H is mounted to revolve in a bearing
on the haminer frame or other support, and is driven at a suitable speed from an
independent source of power, such as a belt from the shop shafting running on fast
and loose pulleys H1, H2, on shaft H. H³, belt shipper.
It will be obvious that instead of the two arms F, F', being at opposite sides of
the framing, they might be on the same side and form one lever, and work on a
fixed pivot instead of the rock shaft f.
The valve for admitting and discharging steam to and from the cylinder consists
of three pistons K', K2, K³, Figure 1, mounted on one valve spindle, the outer ones
K¹ and K³ being made with lap on the "steam" side. The valve, as shown in
Figure 1, is intended to have steain from the boiler between the pistons K' and K²,
and between K2 and K³, the exhaust steam passing away from the outer sides of the
pistons K' and K³.
It will be observed that the shaft H revolves in the direction of the arrow, and
that crank h is near the middle of its stroke when the tup A is at the end of its
stroke, and vice versa, whereby an up or down motion is given to the fulcrum C, and
therefore to the valve in an opposite direction to that of the tup A during the first
part of its stroke, and in the same direction as the tup A during the latter part of
its stroke, the result of this conjoint action together with the valve having lap on
the "steam" side being that steam can be worked expansively.
Figure 4 represents in elevation, and Figure 5 in horizontal section a slightly
modified arrangement. The same letters of reference indicate the same parts as in
the former Figures, except that a is a groove and B a slide block fitted in it. In
this case the pivot c of bell-crank lever C is stationary on the hammer framing, and
the bell-crank lever C is not connected directly to the valve rod, but carries the

page_text: fulcrum of a lever F, F, whose arm F is jointed to a connecting rod D, and arm F'
to connecting rod G. The system of levers is partly worked from the tup A and
partly from the revolving shaft H, as before, the effect upon the valve being much
the same as above described. The pivot c of the bell-crank lever C is in this case
on the end of the shaft C¹, Figure 5, mounted in the hammer framing, and the
pivot c is slightly eccentric to said shaft C', which has a lever handle Če attached
to it working over a quadrant (not shown), by which the eccentric pivot c may be
turned to any position for the purpose of regulating the force of blow. This com-
bination also allows of steam being worked expansively.
In the above described arrangements a single valve receives motion by the con-
joint action above mentioned.
Figure 6 is an elevation with the valve chest in section of a hammer having two
valves, worked the one by the tup as usual, and the other by a rotary shaft, so as
to impart a differential motion to the two valves.
Figure 7 is a horizontal section of the valve chest taken through the steam port.
K, K¹, is a double piston valve of the ordinary description, made with lap on the
"steam" side of the pistons, and worked in the ordinary way by the tup A. Said
valve K, K¹, works inside a tubular valve L, worked from the rotary shaft H through
crank, connecting rod G, lever F, and valve rod 7. In this arrangement the
tubular valve L is near the middle of its stroke when the tup A (and consequently
the piston valve K, K',) is at the end of its stroke, and vice versa; and the said
tubular valve moves in the same direction as the tup A during the first part of its
stroke, and in an opposite direction during the latter part. By this combination
steam can be worked expansively, as in the combinations previously described.
Having described the nature of my Invention, and the manner of performing the
same, I declare that what I claim as my Invention to be protected by the herein-
before in part recited Letters Patent is,---
1st. In an automatic steam hammer, actuating the valve conjointly by the hammer
head or tup and by an independent source of power, as and for the purpose
specified.
2nd. In an automatic steam hammer, the two several arrangements of gear, sub-
stantially as herein described, and shown in Figures 1, 2, 3, 4, 5, for operating the
same valve or set of valves by the conjoint action of the tup and of an independent
revolving shaft, as and for the purpose specified.
3rd. In an automatic steam hammer, the employment, in combination with the
main valve worked from the tup in the usual way, of an expansion valve actuated
by a revolving shaft or otherwise from an independent source of power, whereby a
differential motion is imparted to the two valves, as aud for the purpose specified.
In witness whereof, I, the said Charles Davy, have hereunto set my hand and
seal, this Eleventh day of October, in the year of our Lord One thousand
eight hundred and seventy-eight.
CHARLES DAVY. (L.S.)