IMPROVEMENTS IN THE VALVES AND VALVE GEAR OF STEAM HAMMERS
Year: 1883

page_text: LETTERS PATENT to John Cochrane, of Barrhead in the County of Renfrew,
North Britain, Engineer for an Invention of "IMPROVEMENTS IN THE
PROVISIONAL SPECIFICATION left by the said John Cochrane at the Office
of the Commissioners of Patents on the 21st November 1883.
JOHN COCHRANE, of Barrhead, in the County of Renfrew, North Britain,
Engineer, "IMPROVEMENTS IN THE VALVES AND VALVE GEAR OF STEAM
HAMMERS
و"
This Invention has for its object by improved arrangements of the valves and
valve gear of steam hammers to provide in a simple and efficacious manner for
varying the force of the blow, and for making the hammer self-acting or not as
required.
"
In carrying out the Invention two piston valves on one spindle are employed
for controlling the entrance and escape of steam to and from the two ends of the
cylinder. The lower piston valve and its ports are of an ordinary kind, but the
upper valve and its ports are made with inclined lower edges and the valve and
its spindle are arranged so that they can be turned by means of a regulating.
handle. When the hammer is working with the self-acting gear the valves have
always the same stroke but the amount of opening of the upper ports for the
admission of steam is made more or less by turning the valve, which brings the
inclined or angled edges of the valve and ports nearer together or further apart,
and causes the amount of opening to be varied accordingly. The spindle of the
valves is turned by means of a handle engaging with it by a groove and key but
otherwise loose so as whilst held between brackets, to allow of the up and down
movement of the spindle. The lower end of the spindle is connected by a swivel
joint to a small block which is loose on a pin in a lever fixed on a horizontal spindle
and which lever is raised by the hammer block when approaching the upper end of
its stroke. The horizontal spindle of the lever is carried in bearings on the

page_text: hammer standard or frame and has a hand lever upon it; it has also loose on it a
lever connected by a link to a slotted lever which last is acted on by a pin fixed to
the hammer block for the purpose of lowering the valves as the block approaches
its lowest position. The loose lever on the spindle and the lever fixed thereon and
connected to the valve spindle are formed with lugs or projections which engage
with each other when the horizontal spindle is in the position for making the
hammer self-acting, and when it is desired to work the hammer by means of the
band lever, the horizontal spindle is moved on end so as to take the sougs on the
lever fixed on it clear of the snugs on the loose lever. A pin and holes are
provided for securing the horizontal spindle in either of its two positions.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said John Cochrane in the Patent Office on the 20th May 1884.
· JOHN COCHRANE, of Barrhead in the County of Renfrew, North Britain,
Engineer, IMPROVEMENTS IN THE VALVES AND VALVE GEAR OF STEAM
HAMMERS
"
"
My said Invention has for its object by improved arrangements of the valves and
valve gear of steam hammers to provide in a simple and efficacious manner for
varying the force of the blow, and for making the hammer self-acting or not as
required.
""
In carrying out my Invention two piston valves on one spindle are employed for
controlling the entrance and escape of steam to and from the two ends of the
cylinder. The lower piston valve and its ports are of an ordinary kind, but the
upper valve and its ports are made with inclined lower edges, and the valve and its
spindle are arranged so that they can be turned by means of a regulating handle.
When the hammer is working with the self-acting gear the valves have always the
same stroke, but the amount of opening of the upper ports for the admission of
steam is made more or less by turning the valve, which brings the inclined or
angled edges of the valve and ports nearer together or further apart, and causes the
amount of opening to be varied accordingly.
The valves are worked by means of a rocking shaft having on it a hand lever
which is loose when the self-acting parts are in gear, and when the valves are to
be worked by hand instead of by the self-acting gear the rocking shaft is moved
on end to disengage the self-acting part and the hand lever is then fixed to it by
means of a pin or cotter.
And in order that my said Invention and the manner of performing the same
may be properly understood I hereunto append a sheet of explanatory drawings to
be hereinafter referred to and representing the main parts of a steam hammer as
fitted with my improvements.
Figure, 1, is a sectional side elevation, figure, 2, is a development diagram of the
upper valve and ports; and, figure, 3, is a sectional plan of part of the valve gear.
In these drawings the same reference numerals are used to mark the same or like
parts wherever they are repeated.
土
The admission and escape of the steam to and from the two ends of the hammer.
cylinder, 4, by the passages, 5, 6, is controlled by two piston valves, 7, 8, which are
formed or fixed on a spindle, 9, and work in a cylindrical shell, 10, formed with
ports communicating with the cylinder passages, 5. 6. Steam has access to the
valves through ports round the middle part of the shell, 10, whilst the exhaust
steam escapes from the ends of that shell. The lower valve, 8, is like an ordinary
piston valve, but the upper one, 7, is made with its lower edges inclined or angled
as shown in figure, 2, which represents the circumferential surface of the valve as
developed or flattened; the upper ports in the shell, 10, being of a similar form as
indicated by the dotted lines in figure, 2. With this form of the valve, 7, and its
ports it will be obvious that with a fixed stroke or vertical movement of the valve,
the ports will be more or less opened accordingly as the valve is turned more or
less round in a direction corresponding to a movement of the development shown in
figure, 2, towards the left hand relatively to the ports. The valve spindle, 9, passes
downwards through a stuffing box, and for turning it there is placed on it a bevil
wheel or bevil-toothed sector, 11, which gears with a similar wheel or sector, 12,
centered on a stud and having a hand lever, 13, fixed to it. The bevil wheel or
sector, 11, is loose on the valve spindle but made to turn it by a feather and
groove. The valve spindle, 9, continues downwards below the bevil wheel or

page_text: sector, 11, and has at its lower end a ball-and-socket joint by which there is
connected to it a rod, 14, having its lower end connected by a double joint, 15, to
a lever, 16, which is fixed to a horizontal rocking shaft, 17.
The rocking shaft, 17, is carried in bearings formed for it on the inner side of
the hammer standard, 18, and there is on the shaft a hand lever, 19, which when
it is fixed on the shaft serves for working the hammer valves by hand. The self-
acting gear for working the valves comprises a stud, 20, fixed in a lug on the
hammer head, 21, and working in a slot in a lever, 22, centered on a lug formed on
the standard, 18; and this lever, 22, is connected by a link, 23, to a short lever, 24,
which is loose on the rocking shaft, 17. The boss of the short lever, 24, is formed with
projections, 25, designed to engage with corresponding projections, 26, upon the boss
of the lever, 16, which is fast on the rocking shaft, 17; and when the parts are in the
positions in which they are shown in figure, 3, the downward movement of the ram
acting through the lever, 22, link, 23, and short lever, 24, moves the rocking
shaft, 17, and lever, 16, so as to lower the valves, 7, 8. When the ram rises, the
head, 21, acts on the lever, 16, so as to raise the valves, 7, 8, and admit steam to
the upper end of the cylinder. The rocking shaft, 17, can be moved a little
endways in its bearings and when drawn out at the end where the hand lever, 19,
is placed, the lever, 16, is thereby moved so that its projections, 26, are clear of the
projections, 25, on the short lever, 24; and then the self-acting gear is disengaged.
A pin or cotter, 27, is provided for fixing the boss of the hand lever, 19, on the
rocking shaft, 17, when it is wished to work the valve gear by hand. The ball-
and-socket connection between the valve rod, 9, and the lower rod, 14, and the
double joint, 15, between the latter and the lever, 16, allow of the turning of the
valve spindle, and also of the slight angular movements of the lower rod, 14, caused
by the movements of the parts to which it is connected.
Having thus particularly described my said Invention and the manner of
performing the same I have to state that I do not restrict myself to the precise
details herein described or delineated but that what I believe to be novel and
original and claim as the Invention secured to me by and in terms of the
herein before in part recited Letters Patent is :-
1. The making of the edges of the valve and of the ports by which steam enters
the top of the hammer cylinder of an angular form combined with arrangements
for turning the valve independently of its longitudinal movements substantially as
herein before described.
2. The arranging of the valve gear so that it can be changed from self-action to
hand-action substantially in the manner herein before described.
In Witness whereof, I, the said, John Cochrane have hereunto set my hand
and seal this nineteenth day of May in the year of our Lord One thousand eight
hundred and eighty-four.
Witness
EDMUND HUNT
Patent Agent
Glasgow
JOHN COCHRANE (L.S.)