Appliance to Prevent Racing of Marine Engines.
Year: 1896

page_text: Date of Application, 21st July, 1896
Complete Specification Left, 12th May, 1897-Accepted, 21st Sept., 1897
PROVISIONAL SPECIFICATION.
Appliance to Prevent Racing of Marine Engines.
FREDERICK EDWARD SHEAN, 360 Upland Road East Dulwich, S.E. Engineer, do
hereby declare the nature of this invention to be as follows:-
To so control the speed of Marine Engines, as to Prevent their "Racing."
This is effected by (when the engines first "fly off") making coinmunication
between the two ends of the cylinder, i.e. on opposite sides of the piston of each
main engine, and thus transposing the pressure from that side of the Piston where
it is causing the Racing, to the opposite side, where it will oppose it.
The appliance for directly effecting this object is a cylindrical chamber, attached
to the main engine cylinder, and containing a double cylindrical or piston valve. I
call this compound, the "speed controller" or "controller." The axis of the
controller is parallel to that of the main cylinder, to which it is attached.
The interior of each end of the main cylinder is connected, by a portway, with the
interior of the controller cylinder. The top-end portway entering the controller near
its top-end; and the bottom-end port-way entering near its bottom-end.
Ordinarily, the valves cover the portways in the controller, the upper valve the
upper port, & the lower valve the lower port.
Both valves move together, so, that, when one opens one port, the other opens the
other port; and, the two opposite ends of the cylinder communicate, through the
controller.
The action of the controller valves is produced, by a light, sensitive.governor,
opening and closing communication, between, the controlling appliance, and a
pressure, or vacuum source.
T
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1000
Appliance to Prevent Racing of Marine Engines.
FREDERICK EDWARD SHEAN 360 Upland Road London, S.E. 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:-
To so control the speed of Marine Engines, as to prevent their racing.
This is effected, by-when the engines attempt to "fly off"-making communica-
tion between the two ends of the interior of the cylinder, on opposite sides of the
piston of each main engine; thus transferring a portion of the pressure from the
side of the piston, upon which it is causing the racing, to the opposite side of
the piston, where it opposes the racing.

page_text: This compound Figs. 1 & 2, is called the controller," & one, such is fixed to each
main cylinder, the axis of the controller cylinder being parallel to that of the main
cylinder to which it is attached.
Each end of the interior of the main cylinder c is connected by a portway p, to the
outside of the controller valve b. The top-end portway, enters the controller near
its top-end; and the bottom-end portway enters the controller near its bottom-end.
Ordinarily, the valves b cover the ports, in the controller a i.e. the upper valve,
the upper port; and, the lower valve, the lower port.
The controller valves b work in equilibrio, firstly, because they form the connected
ends of a hollow cylinder, and, secondly, because port pressure tending to wear the
faces, is obviated, by extending the port p as a recess, around them. With the same
object, and, also, for the purpose of getting greater opening for little movement,
the valve port f too, is carried around in segments.
Both valves, are connected, by a rod y & work together, so that both ports are
opened at the same time, when the two ends of the interior of the main cylinder,
upon opposite sides of the piston, communicate through the controller, a.
The action of the controller valves, b, is produced by the sudden difference of
speed between the main engines, and a form of governor, or speed-transmitter,
Fig. 3. This latter consists of a spindle A running upon two bearings, and carrying
a driving pulley n a driving, or active disc, o, & a loose, and heavier disc, p.
The active, or driving disc, o, has, at least two horns, or projections q, from its
face, which enter corresponding recesses in the face of the loose disc, p, and, with some
latitudes in the direction of revolution, afforded by the difference of the thickness
of the horn, and the breadth of the recess, which limits the angular travel of the
horn, in the recess.
These horns, p are near the periphery of the active disc, and upon opposite radii
of the same diameter; and, are for transmitting increase, or decrease of the speed
of the main engines, to the inert, loose disc, p.
At a lesser distance from the centre,-say, half way between it and the periphery
of the active disc o either on the same or another diameter, are two other
projections, or horns, t, which, also, enter corresponding recesses, u, in the loose disc
and, with room, also, for angular movement.
But, the outer parts of these inner horns, t, i.e. those farthest from the face of the
disc, o, of which they are a portion, are bent backwards, so far, in opposition to the
direction of revolution, as to form a "claw," the inner and outer portions of which
are two parallel faces v & wat an angle of some 45° to that direction.
These inner horns t, open and close the motor-valve z and their recesses are,
therefore, carried through the loose disc p.
Upon the side of the loose disc p furthest from the driving disc o, the
spindle carries, loosely upon it, a short light, hollow shaft, or sleeve y which, near the
loose disc p, radiates into two short arms, z. At the inner recesses, or holes through
the loose dise p these arms z, take the form, and direction of those holes, which, at

page_text: a working fit, they partly fill; and their ends contain oblique faces, corresponding
to those of the inner horns, t, of the driving disc o, of which they are the
complement.
The spindle A. is bored hollow, from the end opposite to the driving one, up to the
loose disc p nearly.
In the hollow lies a rod B which is cottared to the sleeve y, but, the cottar is free
to move an inch, or two, longitudinally, in a slot C, in the spindle, A, which slot also
allows of a small angular movement, due to that of the loose disc p, on the
spindle, A.
The outer end of the rod, B, (which is cottared to the sleeve y at its inner end) is
connected to the cylindrical motor-valve z whose office is to supply, or exhaust the
pressure, as necessary, to open, or close communication, between the opposite sides
of the main pistons.
This pressure, may be either steam, or atmospheric; and, may be exerted directly
upon the controller valve b, through a pipe k or lor, by rods and levers, worked by
a small piston.
To simplify description, let the adoption of atmospheric pressure be assumed.
Then, the pressure acts upon the area of the upper valve b (to which the air has
access) by the space, or clearance a, under the lower valve, being opened to the
condenser.
The ordinary position of the valves, ie, covering the ports, is maintained by two
coiled springs D one at either end of the rod, g, which connects the two valves, b.
The upper spring D acts against the opening pressure, and the lower spring
with it.
The lower spring D acts against the closing pressure, and limits recoil.
ACTION OF THE GOVERNOR.
When the engine speed is regular, the active and inert dises have equal velocity.
Any sudden increase of the engine speed increases, at the same instant that of the
active disc o, which, being impelled forward, brings the front oblique faces of the
inner horns t and those of the sleeve arms together, by that face which is a portion
of the active, and inflexible driving disc o, pressing that of which is a portion of the
loose and yielding valve-gear, against the inert, and heavy loose dise p, when, from
the obliquity of the faces, the latter is set forward, or further from the driving
dise, o.
By that forward movement, the motor-valve a opens communication between.
condenser and controller.
The active disc o, then transmits the increased velocity to the inert disc p, by the
impact of the outer horns q, against the sides of their recesses, 8.
But, before this occurs, the motor-valve r is fully open; whence, pressure is exerted
to open communication between opposite sides of the piston, before the driving disc
has imparted the increase to the inert one.
At the instant that the speed of the engine slackens, that of the active disc o, does
so, to the same extent, whilst the momentum of the loose disc p carrying it on,-the
contact of the discs is broken. The rear oblique face of the "claw "t, meets the
corresponding one of the sleeve-arm z and, pressing it against the rear of its recess, in
the inert dise p. draws it back.
By that backward movement the motor valve closes communication with the
condenser, and opens to the atmosphere, before the decrease of speed is imparted to
the loose disc. That is to say, pressure is exerted upon the controller to close
communication between opposite sides of the piston, before the decrease is imparted
to the loose dise, p
The hollow cylindrical motor-valve a is provided with narrow, circumferential ports,
three towards each end; and one broad port, in the middle.
The valve works in a hollow cylindrical matrix, or face w (which it accuratel

page_text: fits) containing corresponding circumferential ports, towards the ends & in the
middle. Those at one end G, lead to the atmosphere, those at the other F, to the
condenser; and the middle one to the controllers; the latter is always open.
The sensitiveness of the governor is reduced, as necessary, by the tension of an
adjustable spring, I.
If steam, or air, above atmospheric pressure, be used to work the controller valves,
the position of the controller is inverted.
If rods and levers be used to work the controller valves, the controllers have no
springs, and the controller cylinders, instead of being closed, by the discs of the two
valves, may be closed by their own covers, through which the valve-rod will work,-
the valves then being fully open, and perfectly in equilibrio.
The motive pressure, for the controller valves, may be outside them, upon a separate
small piston, instead of inside upon the valve, the discs of the valves, then, would,
as in the case of rods and levers being used, (above), be removed; and the valves
work in perfect equilibrio.
The controller valves are double, and at a distance from each other, merely in order
to lessen the length of port-way between the main cylinder, and that of the controller
when the latter is ready for operation.
With a single valve, the controller would be much shorter, and the portways much
longer.
When the controllers are not working, a cock-plug d closes the port-way.
The controller valves do not bear against their rod, but only upon its collars.
Controllers may be fixed uniformly, before, abaft or, on one side of the cylinders;
or, irregularly, where convenient.
The inner and outer horns of the driving disc, and the arms of the sleeve may be
three or four, in number; I gave two, for simplicity of description.
To prevent, affecting the vacuum, a separate, small air-pump, with a reservoir of
pressure, above, or below the atmosphere, and of two, or three cubic feet content, may
be used for working the controllers.
The methods employed, to prevent the racing of marine engines have, hitherto, so
far as I know, been directed to stopping the admission of steam to the engines, by
closing the throttle valve.
But, however perfectly the governor, and throttle-valve act, in this connection,
closing the throttle-valve never prevents racing, for the simple reason that, its
immediate cause, i.e. the pressure within the engines is beyond the control of the
throttle-valve:
Therefore, throttling is, and ever has been, powerless to prevent racing; and, can
only mitigate that evil by the comparatively slow process of exhaustion.
This condition existed in the simple, and is increasingly accentuated, in the
compound, triple, and quadruple expansion engines.
The immediate source of the evil being in the cylinders, there, only, lies the field
of rational prevention-the throttle-valve being left wholly out of consideration.
The radical method, herein proposed, although in its crude, and inceptive stage,
seems the basis of finally disposing of the dangers of racing; for, the power of the
controller applied, as it is, at the source of the evil, may, as a preventive, be made
absolute.
Having, now, particularly described, and ascertained the nature of my said
Invention; and, in what manner the same is to be performed, I declare that what I
claim is,
1. Appliance to open communication between the two ends of the interior of a
marine engine cylinder, upon opposite sides of its piston; the said communication

page_text: being with the object, and for the purpose, of controlling the speed, and preventing
the racing of marine engines.
2. Connecting, by means of a pipe, or otherwise, any source of pressure, or partial
vacuum, with the said appliance, for the purpose of opening communication, between
opposite sides of the cylinder piston, before mentioned.
3. A form of Governor, or speed-transmitter, in which, sud len difference of speed
of the main engines shall-by bringing together two oblique metallic faces, one of
which is a part or an attachment of the driving disc, active, & unyielding; and the
other, a part of the motor-valve gear passive, and yielding-open, or close the said
motor-valve, which, in effect, opens, or closes communication between opposite sides
of the piston, in the main cylinder, before mentioned.
DL: 10th dose of 1007