Improvements in Governors for Steam Engines.
Year: 1892

page_text: Date of Application, 30th Apr., 1892
Complete Specification Left, 28th Feb., 1893-Accepted, 15th Apr., 1893
PROVISIONAL SPECIFICATION.
Improvements in Governors for Steam Engines.
We, JAMES THOMPSON MARSHALL and REGINALD WIGRAM, both of Steam
Plough Works, Leeds, in the County of York, Engineers, do hereby declare the
nature of this invention to be as follows :—
Our invention relates to a construction of governor which, arranged on the
crank shaft of a steam engine, serves to vary the stroke of the slide valve, reducing
it when the engine moves too fast and increasing it when the engine moves too
slow. We also construct this governor in such a manner that we can combine with
it, when desired, a second governor which varies the stroke of the eccentric
working an expansion valve or the supply valve for the high pressure cylinder,
when the engine is a compound one. On the crank shaft we fit free to revolve a
casing baving a circumferential ring of considerable weight so that we can take
advantage of the inertia and momentum of this ring as we shall presently describe.
To this ring we pivot two heavy arms with loads on them preferably adjustable,
and those arms we connect by links symmetrically arranged to an eccentric boss
which is fitted free to turn on the shaft. On the shaft we fix a disc or plate which
carries a bell crank; one arm of this bell crank is linked to the ring, the other
arm is linked to another eccentric which encloses the former. The heavy arms
are urged towards the shaft by springs which resist their centrifugal force when
the whole system revolves with the shaft. When the speed of the shaft increases,
the ring, owing to its inertia, tends to lag behind, and at the same time the heavy
arms by their centrifugal force move outwards, being aided by their connection to
the ring. The result of this movement is to turn the two eccentrics relatively to
each other so as to reduce the throw of the outer eccentric which is connected
to the main slide valve.
When the speed of the shaft diminishes, the converse action takes place. When
an expansion or high pressure supply valve is desired to be also governed, which
in many cases it is preferable to do, we mount within the same ring casing another
pair of heavy arms which operate as governor balls, turning in the one direction
or the other a sleeve on the shaft. This sleeve has on it an eccentric for the high
pressure or expansion valve with a slotted hole allowing it to be shifted on the
sleeve to a greater or less degree of eccentricity, and the sleeve being made with
teeth gearing with rack teeth on the eccentric, this alteration in the position of the
eccentric results from the action of the governor arms which move the sleeve.
Dated this 30th day of Anril 1802
ABEL & IMRAY,
Agents for the Applicants.
COMPLETE SPECIFICATION.
Improvements in Governors for Steam Engines.
We, JAMES THOMPSON MARSHALL and REGINALD WIGRAM, both of Steam
O Plough Works, Leeds in the County of York, Engineers, 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 :-
Our invention relates to a construction of governor which, arranged on the crank
shaft of a steam engine, serves to vary the stroke of the slide valve, reducing it
when the engine moves too fast and increasing it when the engine moves too slow.
We also construct the governor in such a manner that we can combine with it.

page_text: when desired, a second governor which varies the stroke of the excentric working
an expansion valve or the supply valve for the high pressure cylinder, when the
engine is a compound one.
"
The accompanying drawings illustrate both the simple and the compound
governor according to this invention.
Figure 1 is an elevation and Figure 2 is a section on X X of Figure 3 which
is a plan of the simple governor.
Figures 14, 24 and 34 are corresponding views of the compound governor,
Figure 34 being sectional.
In all the figures similar reference letters are employed as far as possible to
designate corresponding parts.
On the crank shaft Å we fit free to revolve a casing having a circumferential
ring B of considerable weight, so that we can take advantage of the inertia and
momentum of this ring as we shall presently describe.
To the ring B we pivot at bb two heavy arms C with loads on them, preferably
adjustable, and we attach to each arm C one end of a helical spring D the other
end of which is attached to the casing B; we connect the arms CC by links e e
symmetrically arranged to an excentric boss E which is fitted free to turn on the
shaft A. On the shaft A we fix a disc or plate F on which is pivotted a bell
crank having its one arm G linked at g to the ring B, the other arm G₁ being
linked at to another eccentric H, which encloses the former excentric E. The
disc F, which is fixed on the shaft, is connected by links ff to the arms C, and
these, being pivotted on the ring B, as the shaft and disc F revolve, the ring Bis
thus also caused to revolve but with certain freedom due to the jointing of the
parts through which motion is communicated to it. The arms C C are urged
towards the shaft by the springs D which resist their centrifugal force when the
whole system revolves with the shaft. When the speed of the shaft increases, the
ring B, owing to its inertia, tends to lag behind, moving the bell crank and partly
turning the excentric H, in the one direction, while at the same time the heavy
arms C, by their centrifugal force move outwards towards the ring B partly
turning the excentric E in the opposite direction. The result of these movements
is so to turn the two excentrics relatively to each other as to reduce the throw of the
outer excentric H which is connected in the usual way to the main slide valve of
the engine, the stroke of the valve being thus diminished. When the speed of the
shaft diminishes, the converse action takes place the stroke of the slide valve being
then increased.
When an expansion or high pressure supply valve is desired to be also governed,
which in many cases it is preferable to do, we mount within the same ring casing B
another pair of heavy arms C¹ C' pivotted to the ring B at 6' 6' and urged inwards
by springs D'D'. These arms C₁ operate as governor balls turning in the one
direction or the other a sleeve E' on the shaft A, to which sleeve they are connected
by links ee¹. On this sleeve is an excentric H for the high pressure or expansion
valve with a slotted hole allowing it to be shifted on the sleeve El to a greater or
less degree of excentricity and at one side of this hole are rack teeth K on the
eccentric, gearing with teeth on the sleeve E¹.
As the governor arms move the sleeve E¹ more or less round according_as the
speed of rotation is greater or less, its teeth, acting on the rack teeth K, slide
the excentric H' so as to give it less or greater throw, thereby modifying the
opening of the expansion or high pressure supply valve to which the excentric H¹
is connected and reducing or increasing the supply of steam.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
1. A governor for a steam engine consisting of a heavy ring having pivotted on
it loaded spring arms which are linked to a disc fixed on the engine shaft and are
also linked to an excentric boss enclosed within another excentric which is con-

page_text: nected to the slide valve of the engine and which is linked to one arm of a bell
crank pivotted on the disc, its other arm being linked to the heavy ring, so that
according as the whole system revolves at less or greater speed the outer excentric
has greater or less throw, giving the slide valve a greater or less stroke,
substantially as described.
2. In combination with a governor such as is above referred to a second governor
with heavy spring arms pivotted to the ring and linked to a boss having teeth
gearing with rack teeth in the hole of a sliding eccentric which is connected to the
expansion or high pressure supply valve of the engine, so that, according as the
system revolves at less or greater speed, the eccentric has greater or less throw,
causing the expansion or high pressure supply valve to give a greater or less supply
of steam, substantially as described.
Dated this 24th dow of Februa 1902
ABEL & IMRAY,
Agents for the Applicants.