Year: 1888

page_text: Date of Application, 7th Apr., 1888
Complete Specification Left, 7th Jan., 1889
Complete Specification Accepted, 2nd Mar., 1889
FRANK WILLIAM DODD of 16 Osborne Road, Forest Gate in the County of
Essex, Engineer, do hereby declare the nature of this invention to be as follows:-
:―
This invention relates to a novel construction of governor which, both from economyof
space and economy of manufacture, will offer considerable advantages to the builder
of steam engines.
In constructing my improved governor, I avail myself, as heretofore, of the use of
centrifugal action for contracting the supply of steam to the engine, and I make this
controlling power adjustable independent of the speed at which the engine is driven.
In a steam tight case I mount, on side trunnions, a hollow cylinder having closed
ends and helically formed steam passages in its side.
This cylinder I fit internally with two sleeve valves for controlling the steam
passages in the cylinder. The forward ends of these valves are cut helically for the
purpose of regulating the length of the steam passages.
Connected with each sleeve valve is a central rod which carries a crank arm for
the purpose of imparting an axial motion to the sleeve valves when it is desired to
contract the length of the steam ways of the cylinder.
One trunnion of this cylinder opens into an adjacent chamber coupled with the
steam supply pipe, for the purpose of admitting steam freely to the cylinder, and
through the end of this chamber and the hollow trunnion passes a screwed spindle
which connects, by a grooved collar or its equivalent, with the pins of the crank arms
carried by the valve rods.
By turning this screwed spindle, an axial motion is imparted to the sleeve valves,
and thus a permanent adjustment may be communicated thereto for determining the
length of the steam passages in the cylinder.
The other trunnion of the enclosed cylinder may be locked to the crank shaft of
the engine which is to be governed, or it may be connected by a band and pulleys, or
gearing, to the crank shaft, for the purpose of imparting rotary motion to the
cylinder in the steam tight casing.
This casing is connected directly or indirectly with the steam chest of the engine,
and it is through the case that the engine is supplied with steam.

page_text: When the engine is set in action, it will cause the governor cylinder to revolve,
and as its speed increases, the sleeve valves, which are held back by one or more
coiled springs, will be caused to move outwards, and as the speed increases,
contract the openings for the passage of the steam from the cylinder to the casing
enclosing it.
As, however, the speed of the engine drops, and the centrifugal force imparted to
the sleeve valves decreases, these valves will, under the action of their springs, move
back towards their centre of motion, and enlarge the openings in the cylinder for the
passage of the steam therefrom to the surrounding case, which is in communication
with the steam chest of the engine.
From this explanation it will be understood that the size of the governor will be
determined by the capacity of the engine, it being required to pass a sufficient supply
of steam to work the engine with which it is connected.
Dated this 7th day of Anril 1888
NEWTON & SON,
Agents for the Applicant.

page_text: I FRANK WILLIAM DODD of 16 Osborne Road, Forest Gate in the County of
Essex, 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 :-
This invention relates to a novel construction of governor, which, both from economy
of space and economy of manufacture, will offer considerable advantages to the builder
of steam engines.
In constructing my improved governor, I avail myself, as heretofore, of the use of
centrifugal action for contracting the supply of steain to the engine, and I make this
controlling power adjustable independent of the speed at which the engine is driven.
In a steam-tight case connected with the steam chest of the engine, I mount, on
side trunnions, a hollow cylinder, having closed ends, and peripherical steam passages
formed in it.
This cylinder I fit internally with two valves for controlling the steam passages in
the cylinder. The forward or advancing ends of these valves serve to regulate the
capacity of the steam passages.
One trunnion of this cylinder connects with the steam supply pipe, which is led into
the steam-tight case for the purpose of admitting steam freely to the cylinder, from
which it passes in regulated quantity to the engine with which the governor is
connected.
The steam regulating cylinder is driven by the engine with which it is connected,
in order to actuate the valves contained within it, which valves, as the speed of the
engine increases, will contract the steam passages in the revolving cylinder, and
thereby check the supply of steam to the steam chest of the engine.
In the accompanying drawings, Fig. 1 represents in sectional plan view, one form
of my centrifugal governor, and Fig. 2 is an end view of one of the valves detached
from its cylinder.
AA is a steam tight case fitted with bearings to receive the trunnions 6 b' of a
revolving cylinder B, which is closed at its ends.-The trunnion 61 is made solid,
and is fitted with a pulley or a gear-wheel (not shown in the drawings) for receiving
rotary motion from the engine to which the governor is applied. The trunnion bis
made hollow, and fits loosely, but steam-tight, in a cored out passage in the casing
connecting with the steam supply pipe C.
Within the cylinder B, and situated at opposite sides of the axis of motion of the
cylinder, are two sleeve valves D, which are pressed towards the axis of motion of the
cylinder by coiled springs E E.
dd are inclined peripherical passages cut through the walls of the cylinder B, their
object being to pass the steam admitted by the hollow trunnion b to the cylinder B,
into the case A surrounding the cylinder, and thence, by a pipe A¹, to the steam chest
of the engine.

page_text: The forward or advancing edges of the sleeve valves are cut to correspond to the
inclination of the steam passage d.
This arrangement provides for the virtual shortening or lengthening of these
passages, by giving the sleeve valves an axial adjustment, and thereby regulating the
delivery of steam to the engine independently of the speed of the governor. The
manner of effecting this adjustment will be presently explained.
Supposing now the engine to be working at its normal speed, the position of the
valves D will be such as to leave the steam passages d fully open as respects their
width. So soon, however, as the normal rate of speed is exceeded, the cylinder will
be driven at a rate that will cause the sleeve valves to advance against the restraining
pressure of their springs E, and partially or wholly close the steam passages d, thereby
contracting, or cutting off, as the case may be, the supply of steam to the engine.
For effecting the axial adjustment of the valves, whereby the length of the
diagonal slots d is contracted or extended, I employ the following contrivance.
are crank pins standing out from the rear of the valves D, and projecting into an
annular groove turned in a collar formed on an adjusting screw F.-This screw passes
through the hollow trunnion of the cylinder, and is mounted centrally thereto.
A screwed bearing is formed in the case A to receive the screw F, and it is further
supported, at its inner extremity, in a step bearing formed in the trunnion ¹. The
head of the screw is pierced transversely to receive the end of an adjusting lever, the
depression of which will advance the screw, and thereby cause it to turn the sleeve valves,
and contract the steam passages d lengthwise. By reversing the movement of the
screw, the length of the steam passages will be increased.' A nut fis provided on the
screw for tightening it in its adjusted position.
As the excentric pins d¹ enter an annular groove in the collar of the adjusting screw,
that collar, although stationary, will offer no obstruction to the free revolution around
it of the sleeve valves with their cylinder B.
In same cases, I may find it desirable to rely solely on the centrifugal action of the
governor for controlling the supply of steam to the engine. The apparatus will in that
case take a modified form.
Thus, instead of inclining the passages d, as shown in Fig. 1, I make them annular,
with interposed connecting pieces, and form the valves to correspond thereto.
Fig. 3 is a sectional plan view of an arrangement in which I reply upon the centri-
fugal action established within the revolving cylinder, to contract the steam passages
ja the cylinder.
The valves, in this example, instead of being sleeve valves, are piston valves D,
fitted to rods D¹, which rods pass respectively through the pistons, as illustrated in
the sectional view, Fig. 4, leaving, however, the pistons free to advance towards or
recede from each other.
The extremity of each rod that is passed through the piston, carries a weighted
disc D³, and between the pistons are placed the coiled springs E for maintaining the
normal position of the piston valves.
While the valves are in this position, the steam admitted through the hollow
trunnion to the cylinder B, is free to pass off by the steam passages d.
Each piston rod is provided with a disc D³ cast with a concentric cylindrical
shoulder for receiving and holding concentrically its spring E, and the pistons are
similarly provided with a cylindrical support for the other end of the springs. These
discs D³ are pierced, like the piston valves, to receive the two rods D¹, upon both of
which they slide freely.
The inner face of each disc is formed with a central pointed stud, and between the
studs of the two discs is a pair of arms D³, pivotted in a rocess formed in the solid
trunnion b¹.
F is an adjusting screw, fitted, as in the first described arrangement, in a screwed
bearing, and carrying a coned end f¹, which bears against the back of the pivotted
arms D.
By advancing this cone-ended screw, the arms will be caused to drive the discs D³ further
apart, and thereby compress the coiled springs E, which will thus offer an increased

page_text: resistance to the inward movement of the piston valves, under the centrifugal action set
up by the revolving of the cylinder.
As the cylinder revolves, the piston valves will receive a tendency to move inwards,
or towards each other, by reason of the weighted discs D' moving outwards, and they
will thereby contract the steam passages d, as before explained with reference to
Fig. 1. But so long as the engine to which the governor fitted, works within the
limited speed desired, the springs E will retain the piston valves out of action, leaving
the steam passages d open to their full capacity for supplying the steam to the engine.
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. In a centrifugal motor engine governor, the use of cylindrical slide valves
actuated by centrifugal motion, for controlling the passage through the cylinder
containing such valves, of the steam to be admitted to the motor engine.
2. The means described with reference to Fig. 1 for adjusting the slide valves to
their work.