AN IMPROVED VALVE GEAR FOR STEAM HAMMERS
Year: 1885

page_text: I CHARLES DAVY of Park Iron Works Sheffield in the County of York,
Engineer do hereby declare the nature of my said invention for "AN IMPROVED
VALVE GEAR FOR STEAM HAMMERS" to be as follows:-
My invention relates to an improved self acting valve gear for steam hammers, of
the kind in which motion is imparted to the valve through a lever from the tup or
hammer head and the invention has for its object to dispense with a jointed con-
necting rod between the said lever and the valve spindle and to enable the valve
spindle to be jointed directly to the said lever, and to be guided in its rectilinear
motion by an additional guide situated at a sufficient distance from the stuffing box
of the valve chest to steady the valve in its motion and ensure the proper position
of the gear.
To enable the valve spindle to be connected directly to the lever without the
intervention of a connecting rod it is necessary that the point of connection
between the valve spindle and the lever should move in a straight line instead of
in the arc of a circle as it otherwise would do in consequence of the angular
motion of the lever and to provide for this I make the fulcrum of the lever
movable so that it is free to accomodate itself to the varying position of the lever,
the preferable mode being to mount the fulcrum of the lever upon a radius link
carried by the handing lever or other suitable support. Or the fulcrum might be
mounted on a slide block if preferred, which might also be under the control of
the handing lever.
The lever preferably consists of a rod fitted to slide through a sleeve or bush to
allow for the angular motion of the lever and the rectilinear motion of its point of
connection with the tup.
The fulcrum and also the connecting joint with the valve spindle being attached
to the said sleeve or busb.

page_text: I, CHARLES DAVY of Park Iron Works Sheffield in the County of York,
Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
My Invention relates to an improved self acting valve gear for steam-hammers
of the kind in which the motion is imparted to the valve from the tup or hammer
head through a lever connected to the valve spindle, and the Invention has for its
object to enable the valve-spindle to be jointed directly to the said lever without
the intervention of a connecting rod, and without interfering with the rectilinear
motion of the spindle which may consequently be provided with an additional
guide situated at a sufficient distance from the stuffing box of the valve-chest to
steady the valve in its motion and ensure the proper position of the gear.
Reference is to be had to the accompanying Drawings forming part of this
Specification wherein Figure 1. represents a front elevation of a steam hammer
provided with the preferred arrangement of valve gear; and Figure 2 is a side
elevation of the gear only. Figure 3 is an elevation; and Figure 4 a plan partly
in section of a modification of part of the gear. The same letters of reference
indicate similar parts in all the Figures.
a is the hammer-head or tup, b the valve-spindle, and c d the lever by which
motion is imparted to the spindle from the tup, the range of angular motion of the
lever being indicated by the dotted lines. To enable the valve spindle to be
connected directly to the lever without the intervention of a connecting rod it is
necessary that the point of connection e between the valve spindle and the lever
should move in a straight line instead of in the arc of a circle as it otherwise
would do in consequence of the angular motion of the lever and to provide for this
I make the fulcrum f of the lever movable in a direction perpendicular to the
valve spindle so that it is free to accommodate itself to the varying angle which
the lever makes with the valve spindle. The preferable mode is to mount the
fulcrum f of the lever upon a radius link g carried by the handing lever / whereby
the fulcrum may be raised or lowered to vary the cut-off and regulate the force of
the blow in the usual way. Or, the fulcrum f might be mounted in a slide block
movable in a slot in the part d of the lever (see figures 3 and 4) the fulcrum
being as before under the control of the handing lever h.
In either case the lever is divided into two parts consisting of a rod c fitted to
slide telescopically through a sleeve or bush d to allow for the varying distance
between the points of connection of the lever with the tup and valve spindle,
consequent on the angular motion of the former and the parallel motion of the
latter. The fulcrum fand the joint e are attached to the said sleeve or bush.
The valve spindle b is guided in its rectilinear motion by an additional guide k
situated near its point of connection with the lever cd, this point of connection
being thus constrained to move in a right line.

page_text: Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed; I would observe
that I lay no claim to the exclusive use of the telescopic construction of lever for
working the valve except when it works on a movable fulcrum as herein specified,
but I declare that what I do claim is;-
1. A self acting valve gear for steam hammers in which the slide valve is
connected directly to a lever operated by the hammer-head or tup; the lever
being mounted on a fulcrum which is movable so as to permit of the rectilinear
motion of the joint of the lever with the valve spindle substantially as herein
specified, the lever being free to accommodate itself in any suitable manner to the
varying distance between the points of connection with the tup and valve spindle.
2. A self acting valve gear for steam hammers in which the slide valve is
connected directly to a lever operated by the hammer head or tup, the lever
being made in two parts fitted to slide telescopically the one in the other and
mounted the one part on a fulcrum which is movable so as to permit of the
rectilinear motion of the joint of the lever with the valve spindle substantially as
herein specified.
3. In a steam hammer valve gear the combination with the tup and valve
spindle of a lever made in two parts sliding the one in the other, the one part
being jointed, direct to the valve spindle and fulcrumed on a radius link or slide
block carried by a handing lever and of a guide whereby the spindle is con-
strained to move in a right line, substantially in the manner herein described and
represented in the drawings for the purpose specified.