IMPROVEMENTS IN GOVERNORS, FOR STEAM AND OTHER MOTIVE POWER ENGINES
Year: 1879

page_text: LETTERS PATENT to Thomas Browett, junior, of Manchester, in the County
of Lancaster, Engineer, for the Invention of "IMPROVEMENTS IN GOVERNORS,
FOR STEAM AND OTHER MOTIVE POWER ENGINES."
PROVISIONAL SPECIFICATION left by the said Thomas Browett at the Office.
of the Commissioners of Patents on the 20th June 1879.
THOMAS BROWETT, junior, of Manchester, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN GOVERNORS FOR STEAM AND OTHER MOTIVE POWER ENGINES.”
My Invention consists in the use of apparatus by which the governing is brought
into action by varying loads upon the engine instead of by variations in speed. The
following is an arrangement which will illustrate my Invention:-The fly wheel,
pulley, or driving wheel is mounted loosely on the crank shaft, but fast thereon is
an arm the outward part of which is connected to a spring, the other end of which
is connected to the said wheel or pulley, and the driving therefore takes place
through the medium of this spring. The outward end of the aforesaid arm carries a
lever provided with a fork which embraces the usual excentric. As the load varies
the spring is compressed or expands, by which means the arun on the crank shaft
becomes altered in position, and by carrying with it the forked lever shifts the
excentric so as to after its throw, it being adapted so as to allow of its sliding
bodily.
In place of the aforesaid spring compressed air or other yielding medium, auch
as weights, may be adapted, between the fast arm and the driving wheel or

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Thomas Browett in the Great Seal Patent Office on the 20th December
1879.
THOMAS BROWETT, junior, of Manchester, in the County of Lancaster, Engineer.
"IMPROVEMENTS IN GOVERNORS FOR STEAM AND OTHER MOTIVE POWER ENGINES."
My Invention relates to governors in which the regulation is brought into action
by varying loads upon the engine instead of by the more ordinary arrangement in
which variations of speed aro employed, and consists in the employment of such
governors to shifting the eccentric or otherwise regulating the inain distributing
valve as distinguished from the throttle valve.
Fig. 1 of the accompanying Drawing is an elevation, and Fig. 2 a section on
the line A, B, of Fig. 1 of one arrangement of my improved governor; the same
letters of referenco are used to the corresponding parts in each Figure of the
Drawing.
At 1 is the crank shaft of the engine upon which are keyed levers 2, 2ª; upon
the bosses 3, 3×, of these levers and capable of turning thereon is mounted the
driving wheel 4 of the engine, the outward ends of the levers 2, 2*, carry pins to
which volute springs 5, 5*, are attached, the other end of such springs being
attached to pins 6, 6*, carried by the driving wheel.
Alongside the lever 2 is a lever 7 carried at one end by the stud or pin 8 passing
through the levers 2, 2*; at its other end is an eccentric 9 for actuating the slide
valve of the engine. Through a slot formed in the eccentric 9 passes the crank
shaft 1, so that the said eccentric may move sideways when it is desired to give it
more or less throw as hereafter described.
Upon the boss of the wheel,4 is a projection 10 in which is fixed a pin or stud 11;
this stud passes through a slot 12 formed in the lever 2 and is provided with a head
upon which a slot 13 formed in lever 7 is capable of sliding.
Having described the working parts I will now proceed to describe their action
in governing the engine.
The springs 5, 5*, are by calculation or experiment so adjusted as to be in the
position shown when the engine is driving its minimum load.
The steam or other motive force acting through a crank upon the shaft 1 turns
the levers 2, 2*, fast thereon in the direction of the arrow 14, and this motion is
transmitted to the driving wheel through the medium of the springs 5,5*; so long
as the load upon the wheel remains the same the parts will revolve, keeping the
same relative position as that shown, but should the load increase it will have the
effect of retarding the forward motion of the wheel 4 in the direction of the arrow,
and the springs 5, 5*, will be compressed. This retarding of the wheel 4 will have
moved the stud 11 carried by the boss of fly wheel in the direction of the arrow 15
relatively to lovers 2; this movement of the stud will cause this lever 7 to turn
upon its fulcrum by means of the slot 13 carrying with it the eccentric 9 further
from the centre of the crank shaft 1, consequently increasing the traverse of the
slide valve, and so allowing more steam to pass into the cylinder in proportion as
the load or resistance upon the driving wheel increases.
When the load again decreases the springs 5, 5*, will again expand, causing the
levers to turn in an opposite direction, thereby lessening the supply of steam, the
amount of compression of the springs varying with the load or resistance on the
engine. I have spoken of the springs 5, 5*, acting by compression, but it will bo
readily understood that such action may be reversed, and they may be caused to
act by their extension.
One of the said springs I have shown with a "dash pot" 17 combined therewith,
and shown on an enlarged scale Fig. 3; such dash pot is to prevent the too rapid

page_text: Another arrangement of governor is shown by Figa 4, 5. The crank shaft is
at 1 carrying the levers 2, 2*, and wheel 4, as in Figs. 1 and 2, but not fully shown
to avoid confusion. This arrangement is intended more particularly for such
engines as are provided with two eccentrics, one actuating the main slide and fixed
upon the crank shaft, the other being for working the variable cut off valve as is
well understood. Upon the crank shaft 1 is keyed the fixed eccentric 18; alonguide
it is an eccentric 19, capable of being rotated on the crank shaft 1, and is provided
with a boss 20 to which are attached one end of bands 21, the other ends of such
bands being attached to a lever 22 carried by a stud 8 carried by lever 2, as in Figa 1
and 2, and turning thereon; the are head 23 of the lever 22 is provided with a screw
pin 24 and a nut 25, to which one end of the bands 21 is attached, so that they may be
tightened. The lever 22 is connected to the wheel 4 through the medium of a link 20
provided with a nut 27 for adjustment. The force of the steam or other motive
power upon the piston acts upon the wheel 4 through the springs 5,5*, as shown at
Figs. 1 and 2, and as the springs are compressed the lever 22 is turned upon its
fulcrum 8 by means of the connecting link 20, and through the bands or strip 21
rotates the eccentric upon the crank shaft 1, giving more or less lead, thereby
regulating the amount of steam passing into the steam cylinder, as is well understood.
In the above description the rolling are and toothless pinion or boss 20 are of
circular configuration on their rolling surfaces, but where any special relative move-
ment of the latter is required the surfaces may be cam shaped, such as a logarithmic
spiral, by which a varying angular motion may be transmitted. Figs. 6 and 7
illustrate an arrangement by which the lever 22 may be used to jactuate a single
eccentric, having a variable amount of throw for regulating the cut off.
A disc 28 carries a boss 29, to which the bands 21 may be attached; this dise
has an incline slot 30 formed in its face; into this slot passes a pin 30* projecting
from the side of the eccentric 31. At 32 is a disc keyed upon the crank shaft across
the face of which is a slot 33, in which a rib formed upon the eccentric 31 is capable
of sliding. The eccentric 31 has a slot 34 formed within it to allow of its movement
on the crank shaft.
The lever 22 actuates the eccentric in the following manner:-When the lever is
turned upon its fulcrum by the varying load upon the engine the disc is thereby
caused to turn upon the crank shaft, the inclined slot therein acting upon the
pin 30 causes the eccentric to be slidden so that its centre is nearer to or further
from that of the crank shaft, thereby lessening or increasing the traverse of the
alide valve as is well understood.
Fig. 8 shows another arrangement of my Invention in which the coiled springs 5,
5*, shown in Fig. 1 and 2, and through which the force exerted upon the crank shaft
by the steam or other motive force is transmitted are dispensed with, and for which
weights caused to move outward by centrifugal action are substituted. At 1 is the
usual crank shaft upon which is keyed a lever 36 jointed at its ends 37, 37*, to
levers 38, 38*, turning upon centres 39, 39*, carried by the wheel 4; these are
provided with weights 40, 40%. The wheel 4 is also connected to the eccentric
by any of the methods I have previously described. When the crank shaft is
revolving with the levers 36, 38, in the position shown and in the direction of the
arrow the engine will be driving its minimum load; but should the load increase
the wheel 4 will be retarded and the levers 36 advancing will cause the levers 38,
38*, carrying the weights 40 which by centrifugal action are tending to be turned
upon their centres in the direction of arrows A, B, to be turned inward as indicated
by arrows 41, 41*, such movement of parts acting upon the slide valve to admit
more steam upon the piston.
.
As the centrifugal action of the weights 40, 40*, becomes less as they approach
the centre of revolution I propose to counteract this by the use of springs 43, 43
which tend to resist the inward motion of levers 38, or the same could be accom-
plished by the weights being caused to act upon the lever 88 by means of inclines
on cams instead of being fixed thereon.
In such engines as have valves that admit steam by their partial rotation it is

page_text: desirable that the motion of the eccentric should be transmitted with as little loss
of movement as possible, one arrangement for accomplishing this is shown at Fig. 9.
At 45 is the eccentric rod carrying at its end a frame 46 furnished with screwed pins
and tightening nuts 47, to which are attached bands 48, 48*, the other ends of
which pass partially around and are attached to a drum 49 fast upon the valve
spindle 50. Upon the valve spindle 50 swings a cradle bracket 51 to support and
guide the frame 46. The rectilinear motion of the eccentric rod is converted in a
rotatory motion through the wrapping and unwrapping of the bands 48, 48, upon
the drum or pulley 49; or in place of the bands I use a toothed rack, as shown at
53, Fig. 10, taking into the tecth of a toothed wheel 54 mounted fast upon the valve
spindle 50.
In all the preceding descriptions of mechanism I have assumed that the engine is
required for driving in one direction only, but in cases when the engine is required
to reverse, it will be understood that the spring mechanism through which the force
is transmitted will have to be reduplicated on the other side of lever 2, 2*, and the
slot in the eccentric 9 through which the crank shaft passes must be elongated to
permit of the motion necessary for reversing, as will be understood.
The above mechanism may be used to vary the position of cams relative to the
crank, or in cases where any valve mechanism is actuated by a lay shaft rotated
by gearing from the crank shaft the wheel driving it may be advanced or
retarded by mechanism shown in Figs. 4 and 5, and thereby effect the time of
action of the distributing valves; such wheel will take the place of the eccentric 19,
Fig. 5.
Having thus described and ascertained the nature of my said Invention, and the
manner in which the same is to be performed, I desire it to be understood that I
claim as secured to me in the above in part recited Letters Patent, -
Firstly. The use of governors of the aforesaid description for acting upon the
eccentric or other mechanism which actuates the main distributing valves afore-
Baid.
Secondly. I claim as a special yielding resistance in governors of the aforesaid
type the centrifugal action of weights as described and illustrated by Fig. 8, either
alone or in combination with springs.
In witness whereof, I, the said Thomas Browett, junior, have hereunto set my
hand and seal, this Nineteenth day of December, One thousand eight bun-
dred and seventy nine.