IMPROVEMENTS IN ENGINE GOVERNORS
Year: 1882

page_text: LETTERS PATENT to David Greig and Max Eyth, both of Leeds, in the
County of York, Engineers, for an Invention of "IMPROVEMENTS IN ENGINE
GOVERNORS."
PROVISIONAL SPECIFICATION left by the said David Greig and Max
Eyth at the Office of the Commissioners of Patents on the 17th February
1882.
DAVID GREIG and MAX EYTH both of Leeds in the County of York, Engineers
"IMPROVEMENTS IN ENGINE GOVERNORS."
This Invention refers to governors regulating the speed of engines either by
working a throttle valve or by acting on a variable expansion gear.
Ordinary governors as is well known fail to regulate the speed of an engine
under variable steam pressure and power owing to their peculiarity of assuming a
certain fixed position for a certain fixed speed. They therefore are not able to
vary the opening of a throttle valve at the normal speed of the engine according to
the requirements of varying steam pressure or power. Parabolical or approxi-
mately parabolical governors are intended to overcome this defect but they are
unable to overcome any moderate resistance at slight variations of speed.
To overcome these difficulties we employ any ordinary governor-except para-
bolical or approximately parabolical governors-with the following combination.
The moving sleeve of the governor is connected with two clutch halves mounted
in preference on the governor spindle itself. The corresponding clutch halves are
fixed to or are parts of two bevil wheels loose on the same spindle and goaring both
into a third wheel one gearing with it at the top the other at the bottom. The
shaft of the third wheel acts on a friction coupling which may work a nut or a
worm or any suitable gearing connecting it with the throttle valve or the variable
expansion gear of the engine.
Thus by the rising or lowering of the governor either the upper or lower bevil
wheel will be made to turn and the nut or worm will turn either back or forward
by the power of the engine. This will change the position of the throttle valve or
the expansion valve motion till the engine makes again its normal number of

page_text: revolutions, then the governor resuming its central position will disengage the
clutch leaving thereby the throttle valve or the expansion valve gear in its changed
position.
The clutches are provided with only one or two short claws so as to give them
a ready chance of falling into gear. The surfaces of the claws which get into
contact are not vertical (parallel with the spindle) but slightly inclined the angle
being proportioned to the frictional coefficient of the material employed so that the
frictional adhesion between the claws is balanced or nearly balanced by the wedge
like action which tries to separate the clutches. Thus none or scarcely any power
will be required to disengage the clutches.
The object of the friction coupling is this. Whenever by the continuous action
of the governor in one direction the throttle valve or the slide valve motion has
been worked into one of its extreme positions so that it can go no further than the
friction coupling allows the bevil wheels to turn without further affecting the
motion of the throttle valve whilst at the same time it at once causes the latter to
move in the opposite direction as soon as the governor acts again on the other
clutch.
In some cases it is desirable to change the number of revolutions of an engine
between certain limits at will and without trouble. This we effect by changing
the height of the pendulum of the governor either by lowering or raising the point
of suspension of the governor arms by means of a screw or otherwise or by changing
the central position of the sleeve or by sliding the weights along the governor arins
and locking the weights to the arms in the positions required.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed
by the said David Greig and Max Eyth in the Great Seal Patent Office
on the 17th August 1882.
DAVID GREIG and MAX EYTH both of Leeds in the county of York Engineers
"IMPROVEMENTS IN ENGINE GOVERNORS."
This Invention refers to governors, regulating the speed of engines either by
acting on a throttle valve or on a variable expansion gear.
Ordinary governors, as is well known, fail to regulate the speed of an engine
under variable steain pressure and power owing to their peculiarity of assuming a
certain fixed position at a certain fixed speed. They therefore are not able to
vary the opening of a throttle valve, at the normal speed of the engine, according
to the requirements of varying steam pressure or power. Parabolical, or nearly
parabolical governors are intended to overcome this difficulty, but are unable to
overcome any moderate resistance at slight variations of speed.
To contend with both drawbacks, we employ any ordinary governor except
a parabolical or approximately parabolical governor, with the following
combination.
The governor sleeve is connected with two clutch halves, mounted in preference
on the governor spindle itself. The corresponding clutch halves are fixed to, or
are parts of, two bevel wheels, loose on the same spindle and gearing both into a
third wheel one gearing with it at the top the other at the bottom. The shaft of
the third wheel acts by means of a friction coupling on a nut or a worm, or any
suitable gearing connecting it with the throttle valve or the expansion gear of the
engine.
Thus by the rising or falling of the governor, either the upper or lower bevel
wheel will be made to turn and the nut or worm will turn either forward or
backward, by the power of the engine. This will change the position of the
throttle valve or the expansion valve motion, until the engine makes again its
normal number of revolutions. Then the governor resuming its central position,
will disengage the clutches, leaving thereby the throttle valve or expansion gear
in its changed position.
The clutches are provided with only one claw, so as to give them a ready chancé
of falling into gear. The surfaces of the claws, which are in contact, are not
vertical (parallel with the spindle) but slightly inclined, the angle being in pro-
portion to the frictional resistance of the material employed, so that the adhesion
of the claws is balanced or nearly balanced by their wedge like action, which
tries to separate them. Thus no power, or scarcely any power is required to
separate them.
The object of the friction coupling is this; whenever by the continuous action of
the governor in one direction the throttle valve or the slide valve motion has been
worked into one of its extreme positions, so that it can go no further, then the
friction coupling allows the bevel wheels to turn, without further affecting the
throttle valve, whilst, at the same time, it at once causes the latter to move
in the opposite direction as soon as the governor acts again on the other clutch.
With a governor formed as above the action will be as follows:
Owing to the vis viva of the fly wheel and the accumulated steam in the steam
chest, an engine will continue to make for a short time an increased number of
revolutions even after the throttle valve bas been placed into a position which
otherwise would cause it to revolve at the desired speed. The same takes place, in
the reverse sense, whenever the engine goes slower than it ought to do, and tries

page_text: to recover its proper speed by opening the valve. The consequence in both cases
is, that if a variation in the load upon the engine takes place rapidly the valve is
moved by the governor past the position it ought to reach and this motion
back and forward goes on without allowing the engine to settle down at its proper
speed.
We remove this drawback in the following manner.
We place within each bevel wheel a loose tube which can slide on the governor
spindle, the tube is provided at its its end, with a clutch half, which is acted upon.
by the corresponding clutch half, connected with the governor sleeve. These tubes
can readily slide up and down, being prevented from moving too freely by some
frictional resistance (a spring or an india rubber ring). Each of the tubes is
provided with a short feather, which enters, and slides in a corresponding recess
or key way, within the bush of its bevel wheel. In the central position of the
governor the feathers of the upper and lower tube are both just clear of the bevel
wheels. But a slight movement of the tubes either up or downward brings either
the upper or lower tube into gear with its bevel wheel. Both tubes move up or
downwards, readily with the governor sleeve, and are alternately acted upon by
the clutches connected with this sleeve.
The effect of this arrangement is this. When the speed of the engine rises, the
lower clutch gets into gear, the feather of the lower tube is pushed into its bevel
wheel and the sleeve and tubes rise together, whilst the valve is being closed.
When the (speed-reaches a maximum, and begins to diminish the sleeve sinks,
leaving the tubes behind, so that the clutch gets out of gear, leaving the throttle
valve unaffected, although the speed of the engine may still be considerably above
the normal one. This gives time to the fly wheel, to spend its vis viva, the engine
speed sinking, without any unnecessary movement of the throttle valve. Possibly
it will not come down to its norinal speed, but then the small undulations of the
governor sleeve will keep bringing the upper and the lower clutch constantly and
alternately into gear. Every upward motion will give a further turn to the bevel
wheel which closes the valve every downward motion will have no effect, because
the feather of the upper tube is still out of gear. Thus the engine speed is
gradually coming down to its proper number of revolutions; the same action
taking place, in a reverse sense, when the engine has fallen below its normal
speed.
In preference to using ordinary throttle valves we cause the regulating screw
of the governor to act on a plunger, which is moving in a long tube with two slots
along its whole length, through which the steam passes. These slots we make of
a conical shape, reducing them to a point at the closing end of the valve. By these
means the action of the piston will be approximately in proportion to the remaining
opening of the valve.
The regulating screw can be put into communication with a variable expansion
gear of any ordinary description. But in preference we employ the following
arrangement.
On the back of an ordinary main valve with two separate admission ports
slides an expansion valve, consisting of a plate, carrying a longitudinal cylinder,
within which there are two hollow rings, like ordinary sliding throttle valves, or
like piston valves, which we call expansion rings. Both are connected by a screw,
which has a right hand thread passing through one, a left hand thread passing
through the other ring and both are stationary, when no alteration of the degree
of expansion takes place. The ports in the back of the main valve are so large,
that they are always open towards the ports, in the face of the expansion valve,
the cutting off of the steam being effected by the expansion rings. The eccentric
of the main valve has its usual position, the eccentric of the expansion valve is
exactly opposite to the crank. The screw, which regulates the relative position
of the expansion rings does not move in the direction of its length, but turns
when the governor acts on it, thereby increasing or diminishing the distance
between the two rings, and causing the steam to be cut off sooner or later.

page_text: It can readily be understood, that this valve gear allows a variation of the cut
off from no steam to full, and also that it allows the engine to be reversed without
altering the position of the second eccentric.
Instead of the expansion valve and rings as described, a simple plate might be
employed on the top of which two other plates, corresponding to the rings, might
be worked by a similar stationary screw.
In some cases it is desirable, to change the speed of the engine, without trouble,
and without stopping the engine. This we effect by raising or lowering the
suspension block of the governor arins by means of a screw or other suitable
contrivance. This alters the height of the pendulum of the governor, and at once
causes it to adjust the speed of the engine accordingly.
For the purpose of still further explaining our Invention we now describe the
accompanying Drawings.
Sheet 1 shows a governor of the simpler description acting on a throttle valve,
Figure 1 being the side view of the governor, Figure 2 a top view of the suspension
block, Figure 3 a side view of the bottom clutch Figures 4, 5 and 6 three views of
the throttle valve. Sheet II. shows a governor of the improved type acting on an
arrangement of expansion gear Figure 7 being a side view of the governor,
Figures 8 and 9 sections through the valve chest showing the arrangement of the
expansion gear and Figure 10 indicating the position of the eccentrics on the
crank shaft.
In Figure 1 (Sheet I.) the governor sleeve a is provided at its lower end with
one or two claws, forming a clutch, and is connected by sliding keys to a clutch
collar b, both working into corresponding clutch teeth at the back of the bevel
wheels c and d. These wheels gear into a third one e. On the elongated hollow
shaft of the latter is a friction coupling f formed by a disc which by means of an
india rubber or other spring is pressed against a circular plate keyed on the shaft.
The disc is part of a nut which moves a screw acting on the plunger i of the
throttle valve. This valve consists of a valve seat with a tube shaped central
body l; this tube having two long slits, one upwards towards the steam space
connected with the boiler, the other downwards connecting it with the steam chest.
Within the tube moves the plunger i, regulating the amount of opening required.
The teeth of the clutches are shown in Figure 3 to be inclined, so that the
frictional adhesion between the surfaces, when in contact is as near as possible
neutralized by the wedge like upward pressure, which tries to separate the claws.
The dotted line shows the angle of inclination. By these means the power, to
separate the clutches when in gear is reduced to a minimum.
The object of the friction coupling is to prevent any breakage when the nut h
has worked the plunger to one of its extreme positions either completely closing or
opening the throttle valve.
The suspension block m of the governor arms is supported by a screw which
screws through it as shown-the block can be raised or lowered by turning the
screw by a hand wheel n so as to regulate the speed of the engine to any desired
number of revolutions.
In Figure 7 (Sheet II.) a is the governor sleeve, to which the clutch rings band c
are fixed, one above, the other below the bevel wheels & and e. The tubes g and ƒ
which pass loosely through the bushes of these wheels are provided with corre-
sponding clutch teeth, and are able to slide up or down the governor spindle when
pushed by the clutch rings on the governor sleeve. Each of these tubes is provided
with a projection or feather h which can enter and slide into a corresponding short
key way or slot in the bush of the bevel wheels. With the governor in its central
position each of these feathers h is just clear of the corresponding bevel wheel but
the least movement either up or downward, of the tubes g and makes either one
or the other feather enter the key way in the bevel wheel and it will then at once
shift the position of the valve but in returning to central position it does not shift
the valve and so the engine is allowed time to settle down quietly as above explained.
A wrought iron collar i, cut into two halves held together by an india rubber ring

page_text: prevents the tubes, by friction from sliding up too readily, or from falling down by
their own weight.
The friction coupling is similar to the one already described, but acts on a
pinion and turns a spur wheel on the screw shaft which regulates the position of
the expansion rings.
This shaft, which is prevented from shifting in the direction of its own length
by a suitable collar is coupled to the screw & connecting the two expansion
rings vv by a universal joint within the steam chest. The turning of the screw
either increases or diminishes the distance between the two rings, within the
expansion valve u which is sliding on the back of the main valve t.
The arrangement for lifting the suspension block o of the governor arms is such,
that it can be handled, whilst the governor is at work. The small hand wheel p is
part of the nut of the lifting screw the hand wheel q, is keyed to the screw itself.
Both are at liberty to turn with the governor spindle, but both can be stopped by
hand from turning at any moment and then, holding the bottom hand wheel and
turning the top one, the suspension block is raised or lowered as required, whilst
the governor is in full action.
Figure 10 shows the position of crank and eccentric, connected with the two
valves.
We are aware that governors acting by means of their sleeve on bevel wheels,
similarly in principle to those described, have been employed before, especially for
working sluices of water wheels. These governors, generally working by means of
friction clutches would be quite useless for the more delicate work of regulating
the speed of a steam engine. Without confining ourselves to the special details
indicated in the previous description, we claim therefore as our Invention.
First. The employment in connection with governors on the principle above
mentioned of couplings having only one, or at most two claws the acting surfaces
of which are inclined as herein before described so that the wedge like action of
these surfaces may neutralise the frictional adhesion of the claws.
Second. The employment in connection with governora on the principle above
mentioned of a friction coupling for communicating the movement of the bevel
wheels to the throttle valve or the variable expansion gear.
Third. The construction of engine governors in such manner that the action of
the governor in altering the position of the throttle valve or expansion gear ceases;
whenever the governor, having reached a maximum in its down or upward motion
begins to recede, but has not yet reached its central position.
Fourth. The employment of sliding clutch tubes substantially as herein before
described for effecting the above mentioned object.
Fifth. The construction of engine governors substantially as herein before
described and illustrated in the Drawings annexed.
Sixth. Constructing engine governors with the suspension block of the governor
arms capable of being slid up or down upon the governor spindle and held in any
desired position substantially as described.
In witness whereof I the said David Greig have hereunto set my hand and
seal this Fourteenth day of August in the year of our Lord One thousand
eight hundred and eighty two.