IMPROVEMENTS IN MACHINERY OR APPARATUS FOR STARTING, STOPPING, AND REVERSING STEAM AND OTHER ENGINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by William Henry Allen, Richard Wright,
and William Lawrence Williams at the Office of the Commissioners of
Patents on the 23rd January 1882.
WILLIAM HENRY ALLEN and RICHARD WRIGHT, both of Lambeth in tho
County of Surrey, and WILLIAM LAWRENCE WILLIAMS, of Westminster Chambers,
in the County of Middlesex. "IMPROVEMENTS IN MACHINERY OR APPARATUS FOR
STARTING, STOPPING, AND REVERSING STEAM AND OTHER ENGINES.”
Our Invention relates to machinery or apparatus used for the purpose of starting,
stopping, and reversing marine or other steam engines or other engines, or machines
in which it is required that reversing or other mechanism of considerable weight
should be moved easily and readily either forward or backward when desired, and
at the same time with steadiness and without liability to concussion or sudden
irregularity of motion. It is applicable more especially to that kind of such
apparatus in which the starting, stopping, reversing, or other gear, is actuated by
the pressure of steam in a cylinder, the movement of such piston being controlled
and regulated by a second piston working in combination with it in a cylinder
filled with water or other fluid, openings for the admission and discharge of such
water or other fluid being regulated synchronously with the movement of the
valve by which steam is admitted to or discharged from the steam cylinder.
In such apparatus as heretofore ordinarily constructed and used, the motion of
rams and pistons in reversing engines and other machinery, is controlled by one
valve, which being opened by the hand of the attendant, is closed by the motion of
the said ran:s or pistons (or by mechanism receiving notion from them) gradually
and continuously, and our present Invention bas for its object firstly--improved
methods of construction and arrangement of the mechanism, so that instead of the
valve by which the motion is controlled as described being closed gradually and
continuously, it remains open in the position to which it has been moved by the
attendant until the rains or pistons together with the stopping, starting, or
reversing gear, or other machinery which they actuate, have moved nearly to the
point of their travel corresponding to the position of the valve, which is then
rapidly closed, the time occupied in effecting the desired result being thus greatly
reduced, a matter often of considerable importance in the case of the stopping and
reversing mechanism of marine steam engines, and other machinery.

page_text: Our Invention consists also in improved methods of constructing and arranging
machinery or apparatus for the purpose described, by which improved methods
space is economized, and economy obtained, whilst the hydraulic controlling
apparatus is readily kept filled with water or other fluid and its valves are very
simple and easily actuated, and the piston in the hydraulic cylinder is readily
worked by hand for the purpose of actuating by its means the starting or reversing
or other gear,
if steam should not be available for admission into the steam cylinder
for such purpose. We take a cylinder of suitable size and provided with a slide or
other valve by which steam, compressed air, or other non-clastic fluid, under
sufficient pressure can be admitted to either end of the cylinder, the alternate end
of which communicates with an 'exhaust pipe.
Inside the cylinder and concentric with it we arrange a second cylinder of
smaller diameter and of very considerable thickness, and we fit an annular piston
provided with suitable packing into the annular space between the two cylinders
and a piston also provided with suitable packing into the inner cylinder. The
annular piston is provided with two or more rods, which pass out through
corresponding stuffing boxes in the cover, and the central cylinder is also provided
with a rod passing up through a central stuffing box.
The several piston rods are all connected at their upper or outer ends to a
crosshead working in suitable guides which crosshead is itself connected by one
or more links to a lever upon the weigh shaft or reversing shaft, if a marine.or
other steam engine is to be actuated, or the pistons may be connected in any
convenient way to other machinery which the steam piston is to actuate.
The spindle of the valve by which the steam or other fluid is admitted to
operate the annular pistons, passes through a stuffing box and afterwards forms
part of or is connected to a second valve spindle-passing-through-a-valve-chest.
provided with stuffing boxes and is finally connected by a link to the reversing
lever actuated by the attendant. In the valve chest last described are arranged
two disc valves fitted upon sents into one or both are forced by springs, and
a projection upon the spindle which passes as already described through the valve
chest fits between the tails or spindles of the two valves in such mauner that when
the spindle is raised the upper valve is raised from its seat and opened, and when
it is depressed the lower valve is opened. The space above the upper valvo
communicates by a suitable passage or pipe with the inner cylinder above the
piston in the latter, and the space below the lower valve communicates similarly
with the space below the piston.
These pipes or passages may be provided with adjustable throttle valves.
When, therefore the attendant raises the valve spindle by means of his handle or
lever he lifts the distributing valvo to the steam cylinder, admitting steam below
the annular piston which accordingly rises, and by the saine movement he opens to
a greater or less extent, according to the extent of movement of his lever, the upper
valve in the upper valve chest. The central piston can accordingly rise, forcing
the water above it through the upper valve and down through the lower valve into
the lower end of the inner cylinder.
The weighshaft or other mechanism is therefore actuated by the crosshead, the
steam valve remaining open until it has reached its desired position, and the
attendant then closes it and in doing. so allows the upper disc valve to close and
all motion of the two pistons is at once arrested, the piston in the inner or
hydraulic cylinder being absolutely prevented from moving so long as it is filled
with water and the disc valves remain closed.
If the steam distributing valve be lowered instead of being raised the lower disc
valve is opened simultaneously, the annular and central piston together with the
crosshead being depressed, and the water below the inner piston being allowed to
pass through the lower disc valve so long as the latter remains open.
In order to keep the inner cylinder together with its passage and valve chest
constantly full of water under sufficient pressure, and at the same time to permit
the escape of a quantity equivalent to the piston rod when the latter is entering

page_text: the cylinder, we prefer to arrange a small pipe one end of which enters tlie valve
chest between the disc valves, whilst its other end communicates with the boiler
from which steam is supplied, or other convenient boiler, the pressure in which is
consequently constantly acting upon the water. Or if any supply of water under
sufficient pressure is available from any other source it may be admitted to the
pipe described.
The inner cylinder may be separated from the outer one by a space containing
air or other non conducting substance. In order that the distributing steam valvo
and one or other of the disc valves described may not remain open too long in the
case of the attendant neglecting to close them by means of his lover, we arrange
such lever so that it operates in front of a bar or plate attached to or connected to
the crosshead already described and, having a similar motion communicated to it.
This bar has fixed at each end a stud or stop which at the end of its stroke drives
the lever in the same direction and thus vory rapidly closes the valves and prevents
concussion of the piston against the ends of the cylinders.
We also make a series of holes or notches at each end of the bar or plate, and we
make a corresponding moveable detent upon the lever which can be released or
drawn back by the attendant as he handles the latter. When, therefore, he has
opened the valves by depressing or raising his lever, and has allowed them to
remain open until the crosshead and appliances connected with it have been
brought to the desired point, he closes the valves and releases the detent and the
lever becomes coupled to the moving bar or plate, and the valves remain closed
until he again releases the detent for the purpose of operating the lever, and the
engine cannot possibly move so long as tho lever is connected to the moving bar or
plate in the manner described, without moving with it the said lever and thus
operating the valves and correcting instantly any tendency so to move. Instead
of the disc valves described, we sometimes use an ordinary cock provided with a
lever connected to the hand lever, and arranged so that in its central position it
completely closes all communication between the two ends of the hydraulic
cylinder, but opens such communication if moved more or less in either direction.
Apparatus constructed and operated in the method described according to our
Invention is very simple and easily worked, and very rapid and certain in its
operations. In order to provide for cases where it is required to operate the
crosshead and appliances connected with it when steam is not available, we provide
a pump which can be worked by hand and is arranged in such a manner that
by its means water can be withdrawn from either end of the inner or hydraulic
cylinder described, and simultaneously forced into the other end. And wo arrange
a four way cock of the ordinary well known kind so that the pump may be made
to force water, into either end of the cylinder as desired, and thus to actuate the
piston in either direction. Apparatus constructed according to our Invention may
be arranged in any convenient position to suit the purpose to which it is to be
applied, and instead of a double acting stean cylinder as described, two separato
single-acting cylinders may be used, the hydraulic cylinder being made independent
and arranged in any convenient position.