Year: 1887

page_text: Date of Application, 17th Mar., 1887
Complete Left, 16th Dec., 1887
Complete Accepted, 20th Jan., 1888
We ABRAHAM DAVY junior of Park Iron Works, Sheffield Engineer, and WALFORD
JOHN BENTON of 78 Artisan View Heeley near Sheffield Engineer do hereby declare
the nature of this invention to be as follows:-
"
This Invention relates to improvements in self-acting valve gear for steam-hammers;
and it has for its object to cause the hammer or hammer head to fall dead and pause
on the anvil at each blow, as distinguished from the elastic blow produced when
cushioning is permitted at the underside of the hammer piston, and yet to enable the
usual elastic blow to be obtained when required. To accomplish this object, the steam
distributing valve is actuated by the tup, hammer-head, or piston rod, in any ordinary
manner, and is actuated on the descent by a spring or by steam pressure or by gravity,
the action in either case being under the control of a "cataract," whereby the dis-
tribution valve is retarded in its motion more or less, according to the nature
of the blow required. The distributing valve is consequently disconnected from
and independent of the tup, hammer-head or piston rod, during its fall, so that
the tup or hammer may be made to fall dead and pause on the work before the valve
admits any steam to the underside of the piston, the controlling device or cataract
being adjustable so as to enable either a dead or an elastic blow to be given at will.
The cataract piston is connected to the distributing valve spindle, and works in a
cataract cylinder having a by-pass port leading from one side of the piston to the
other, and controlled by an adjustable by pass cock or valve which may also serve as
the inlet valve, or the passage from one side of the piston to the other may be formed
through the piston itself and be controlled by a valve or its equivalent, having suitable
means of regulation. The cataract cylinder may or may not be chambered out for
part of its working length, so that when its piston has travelled at a comparatively
slow speed for part of its stroke under the control of the by-pass cock or valve, it will
on passing entirely into the chambered part encounter no further resistance, (there
being a free flow of the liquid from one side of the piston to the other) and will then
move rapidly to the end of its stroke in the direction for giving a sudden admission of
steam to the underside of the hammer piston, for making another upstroke of the

page_text: hammer. The by-pass cock or valve may be adjusted so as to offer no resistance to
the motion of the distributing valve, which would then move as though it was connected
directly to the tup, thus causing an elastic blow by the usual cushioning of the steam
at the underside of the piston. The same effect may be obtained by adjusting the
position of the cataract piston relatively to its cylinder, so that it will arrive sooner or
later at the chambered part of the cataract cylinder.

page_text: :
COMPLETE SPECIFICATION.
Improvements in the Valve Gear of Steam Hammers.
We, ABRAHAM DAVY junior, of Park Iron Works Sheffield, Engineer, and
WALFORD JOHN BENTON, of 78 Artisan View Heeley near Sheffield, 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
statemont:
This Invention relates to improvements in self-acting valve gear for steam hammers;
and it has for its object to provide means whereby the hammer or hammer head may
be caused to fall dead and to pause on the anvil at each blow, and which will yet
permit of the usual elastic blow (produced by cushioning the steam at the underside
of the hammer piston) being obtained when required. To accomplish this object, the
steam distributing valve is actuated in the one direction only by the motion of
the tup, hammer head, or piston rod, in any ordinary manner, and is actuated in the
opposite direction by a spring, or by steam pressure, or by gravity, the motion of
the valve in this last mentioned direction being, in either case, under the control of a
"cataract" whereby the motion of the distribution valve is retarded more or less,
according to the nature of the blow required. The distributing valve is consequently
disconnected from, and independent of, the tup, hammer head, or piston rod, during
its fall so that the tup or hammer may be made to fall dead and pause on the work
before the valve admits any steam to the underside of the piston, the controlling device
or cataract being adjustable, so as to enable either a dead or an elastic blow to be
given at will.
(1
32
Reference is to be had to the accompanying drawing forming part of this Specifi-
cation in which figures 1 and 2 represent in sectional elevation, two arrangements
of the valve gear; so much of the steam hammer being shewn as is necessary to
explain the invention. The same letters of reference indicate the same parts in both
figures.
A is the tup, B its piston, C the cylinder, and D D the distribution valve, all as
usual. E is the cataract cylinder fixed to the framing preferably in line axially with
the valve D D and filled with water, oil, or other liquid or a fluid. F is the piston
working in the cataract cylinder, the spindle on which it is fixed passing through the
lower end of the cataract cylinder and abutting upon without being connected to, an
ordinary valve operating lever G pivoted at g and connected at g' to the tup whereby
the valve D D is actuated in the upward direction only, the downward motion being
given to the valve D in the examples illustrated, by a spring H which may either act
in compression as in figure 1, or in tension as in figure 2. The cataract piston Fis
connected by preference directly to the spindle d of the distributing valve or it may
be connected to the valve spindle through a lever or rods; and the cataract. cylinder Ĕ
in which it works, has a by-pass port I leading from the one side of the piston F to the
other and controlled by an adjustable by-pass cock or preferably by a valve & which

page_text: also serves as the inlet valve to the lower end of the cylinder. On the ascent of the
cataract piston, the valve kopens freely to the lower end of the cylinder E and on its
descent closes to the by-pass to an extent regulated by a hand wheel and screw k¹
which prevents the valve closing entirely on its seat. Or, the by pass passage from
one side of the piston to the other may be formed through the piston itself and be
controlled by a valve or its equivalent having suitable means of regulation. The
cataract cylinder may or may not be chambered out for part of its working length as
at e, so that when its piston F. bas travelled through the first part of its stroke at a
speed which is rendered comparatively slow by the resistance of the liquid beneath
the piston and which can only escape to the upper side at a rate regulated by the by-
pass cock or valve, the piston F will on passing entirely into the chambered part of
the cylinder E, encounter no further resistance (there being then a free flow of the
liquid from one sido of the piston to the other) and will then move rapidly to the end
of its stroke, so as to cause valve D to give a sudden admission of steam to the under-
side of the hammer piston B for the next up stroke of the hammer. The by pass
valve may be kept full open, so as to render the cataract practically inoperative,
the distributing valve D then moving downwards as though connected directly to the
Lup, an elastic blow being then caused by the usual cushioning of the steam at the
underside of the piston B. The same effect may be obtained by adjusting the position
of the cataract piston relatively to its cylinder, so that it will arrive sooner or later at
the chambered part e of the cataract cylinder.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is
;-
In a self acting valve gear for steam hammers in which the steam distribution valve
is operated in one direction by the motion of the tup and in the other direction by an
" cataract
independent power, the combination with the distribution valve of a
constructed and acting to retard the motion of the valve in the manner specified.
Dated this 16th day of December 1887.