IMPROVEMENTS IN MECHANISM EMPLOYED TO CONTROL THE SPEED OF STEAM ENGINES."
Year: 1881

page_text: LETTERS PATENT to Herbert Lindley, of the Firm of Messrs. Deakin, Parker,
& Co., of Salford, in the County of Lancaster, Engineers, for an Invention
of "IMPROVEMENTS IN MECHANISM EMPLOYED TO CONTROL THE SPEED OF
STEAM ENGINES."
PROVISIONAL SPECIFICATION left by the said Herbert Lindley at the Office
of the Commissioners of Patents on the 14th May 1881.
HERBERT LINDLEY, of the Firm of Messrs. Deakin, Parker, & Co., of Salford,
in the County of Lancaster, Engineers. "IMPROVEMENTS IN MECHANISM EMPLOYED
TO CONTROL THE SPEED OF STEAM ENGINES."
My Invention relates in the first place to improvements in and connected with
weighted pendulum governors of the class described in the Specification of Letters
Patent granted to Hartnell and Guthrie, bearing date the 13th day of August,
A.D. 1868, and numbered 325. In the said former Invention, weights upon levers
were connected together and moved to and fro radially in a plane at right angles
to the axis of rotation, and the movements of the weights arising from the varying
speeds of rotation were conveyed to mechanism on the fly wheel axis to regulate
the position of the excentric. The object of this part of my Invention is to adapt
this class of governor to engines running at a comparatively low speed, as, for
example, 45 revolutions per minute, whereby I am enabled to obtain greater
sensitiveness and consequently less variation of speed. To this end I form the
governor of a disc or drum having pivoted to it two or more weighted arms, the
tendency of which to move outwards from the centre of rotation is resisted by
suitable springs. This mechanism I propose to mount on a suitable shaft, which is
rotated at twice the speed of the engine crank shaft by means of suitable gearing,
and on this will ride free to rotate on an excentric or cam suitable for actuating the
cut off or expansion valve of the steam cylinder. This valve is free to slide on a
diaphragm or plate fixed in the steam chest of the cylinder plate, which is arranged
so as to bear steam tight against the back of the main valve, and in which is a
|central cavity or port communicating with the "s" ports of the cylinder through the

page_text: main slide valve. This port will be opened and closed twice in each half revolution
of the crank shaft by the cut-off valve. The first time the port is opened it will
distribute steam to the cavity in the plate, and through the ports of main valve
to one end of the cylinder, and then the main valve having moved in the mean
time it will distribute steam to the opposite end of cylinder. In order to vary
the periods relatively to the travel of the main valve at which these double
reciprocations of the cut-off valve shall take place, I cause the excentric or cam
actuating the cut off valve to rotate round the shaft on which it is mounted, and
this I effect by attaching two light links or rods to the said weighted arms, and
also to suitable points on the excentric, so that as the weights move the rods will
rotate the cam in proportion to their movement, which is proportional to the speed
of rotation; for example, if it required a variation of, say, four revolutions per
minute to cause the weights to move thro' their whole path and alter the cut-off
from the earliest to the latest point, this will be effected by half that variation of
the main shaft, and the regularity of the engine will be proportionately increased.
The second part of my Invention relates to high-speed governors, in which one
end of the governor arms by their rotation is caused to bear upon and depress a
spiral or other suitable spring, and consists in the employment of two steel links
or toggles, the object being to reduce the friction and to increase the wearing
Burface.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said Herbert Lindley in the Great Seal Patent Office on the 14th November
1881.
HERBERT LINDLEY, of Salford, in the County of Lancaster, Engineer. "IMPROVE-
MENTS IN MECHANISM EMPLOYED TO CONTROL THE SPEED OF STEAM ENGINES."
My Invention relates in the first place to improvements in and connected with
weighted pendulum governors of the class described in the Specification of Letters
Patent granted to Hartnell and Guthrie, bearing date the 13th day of August,
A.D. 1868, and numbered 325. In the said former Invention, weights upon levers
were connected together and moved to and fro radially in a plane at right angles
to the axis of rotation, and the movements of the weights arising from the varying
speeds of rotation were conveyed to mechanism on the fly wheel axis to regulate
the position of the excentric. The object of this part of my Invention is to adapt
and combine this class of governor to engines running at a comparatively low
speed, say, for example, to engines running at forty five revolutions per minute,
whereby I am enabled to obtain greater sensitiveness and consequently less
variation of speed. To this end I form the governor of a disc or drum having
pivoted to it two or more weighted arms, the tendency of which to move outwards
from the centre of rotation is resisted by suitable springs. This mechanism I
propose to mount on a shaft which is rotated at twice the speed of the engine
crank shaft by means of suitable gearing, and on this shaft will ride free to rotate
an excentric or cam suitable for actuating the cut off or expansion valve of the steam
cylinder. This valve is free to slide on a diaphragm or plate fixed in the steam
chest of the cylinder, which diaphragm or plate is arranged so as to bear steam tight
against the back of the main valve, and in which is a central cavity or port
communicating with the steam ports of the cylinder through the main slide valve.
This port will be opened and closed once in each half revolution of the crank shaft
by the cut-off valve. The first time the port is opened it will distribute steam to
the cavity in the plate and through the ports of main valve to one end of the
cylinder, and then the main valve having moved in the mean time, it will on
opening again distribute steam to the opposite end of cylinder. In order to vary
the periods relatively to the travel of the main valve at which the double
reciprocations of the cut-off valve shall take place, I cause the excentric or cam
actuating the cut off valve to rotate round the shaft on which it is mounted, and
this I effect by attaching two light links or rods to the said weighted arms, and
also to suitable points on the excentric, so that as the weights move, the rods will
rotate the excentric round the shaft through a certain angle proportional to the
amount that the speed of rotation is varied; also, if it requires a variation in speed
of, say, four revolutions per minute, to cause the weights to move through their
whole path and alter the cut-off from the earliest to the latest point, this will be
effected by half that variation of the main shaft, and the regularity of the engine
will be proportionately increased. The second part of my Invention relates to
high speed governors, in which one end of the governors arms by their rotation is
caused to bear upon and depress a spiral or other suitable spring, and consists in
the employment of two steel links or toggles, the object being to reduce the
friction and to increase the wearing surface.
And in order that my Invention may be fully understood, I have caused to be
appended hereunto a Sheet of Drawings to which reference will now be made.
Figs. 1 to 4 represent a method by which the first part of my Invention may be
carried out. Figs. 5 and 6 refer to the second part of my Invention. Figs. 1 and 2
represent respectively a side elevation and plan of an engine governed according to

page_text: To
the first part of my Invention. The valve chest of the cylinder contains a main
valve A and a cut-off valve B, which latter works on a plate C fixed in the valve
chest and bearing steam tight against the back of main valve A. D represents the
governor drum shown on a larger scale in Fig. 4, wherein a, a¹, represents the
weights, and b, b', the springs which tend to draw the weights towards the centre
of the drum during rotation. The weights a, a', are connected to the expansion
excentric by means of links jointed at one end to the pins_c, c', and at the other
end to the expansion excentric by ordinary pin. joints, so that as the weights fly
outwards the excentric is partially rotated round the shaft. This drum, Fig. 4,
with its governing mechanism is an improved form of a type of governor described
in the Specification of Hartnell and Guthrie, for which a Patent was granted on
the 13th day of August A.D. 1868, No. 325. This part of my Invention consists
in a new application of the hereinbefore mentioned governor, whereby the speed of
the engine is kept more regular than is the case when the drum is keyed on the
crank shaft in the ordinary way. To effect this improvement I mount the drum D
on the shaft E, Figs. 1 and 2. The shaft E is caused to rotate at twice the speed of
the engine by means of suitable gearing F, as shown. The excentric which works
the cut-off valve is mounted on this shaft, the excentric of the main valve being
mounted either on the crank shaft or on a shaft G, as shown, driven by a drag link
from the crank pin. The cut off excentric therefore rotates at double the speed of
the engine shaft, and this has the effect of giving a sharp cut-off of the steam.
enable the double motion of the valve to give the proper distribution of steam, I
make the valve single acting, that is, the steam is always cut off at the same edge
or edges, so that an opening is made for the steam only twice in each revolution,
and according to the position of the main valve therefore, steam is admitted either
to one end or the other of the cylinder only twice in each revolution. The earliest
cut-off obtainable by this method occurs when the expansion valve is shutting just
as the main valve is opening, and the latest cut-off occurs when both main and
cut off valves open together, in which case the accelerated motion of the expansion
excentric will cause the cut-off valve to close at about a half stroke according to
the amount of lead given. The Drawings are sufficiently clear for this action to be
understood without further description. Fig. 3 shows an arrangement by which
this part of my Invention can be carried out where it is wished to obtain shorter
steam ports than those shown in Figs. 1 and 2, and as are used ordinarily. In this
case there are two main valves A, A', and two cut off valves B, B¹. The main
valves each work on a face on the cylinder having steam and exhaust ports marked
respectively Hand G. The cut off valves work against a plate c, which is here
shown as a partition, in a box containing both main and cut-off valves, with a lid
to balance the cut-off valve and keep it on its seat. The action of the cut-off valve
is just the same as in the case just considered. The second part of my Invention
consisting in improvements in the class of governors known as high speed governors,
is illustrated by Figs. 5 and 6. Fig. 5 shows one arrangement by which my
Invention may be carried into effect. Fig. 6 is a Drawing on a larger scale of the
ends of the weighted levers, showing the several joints and steel links. In these
Figs. K, K, represent levers weighted at one end and pivoted at L, L'. The other
ends of the levers in governors of this class usually press on a die or button beneath
which is a spring, the outward or centrifugal tendency of the weighted ends being
resisted by the spring, and the motion of the die or button being transfered by
suitable means to the throttle or eqiulibrium valve. To do away with the friction
and wear which always takes place when the ends of the lever press against the
button, I insert between the two parts a steel link or toggle which may have a
rounded or sharp edge, which edges take into grooves cut respectively in the
button and in the end of the lever. These links are shewn at M, M³, and it will be
noticed on reference to the large Drawing, Fig. 6, that these links have only a
slight rocking motion as the button is depressed, and having besides a considerable
amount of wearing surface round their edges are not liable to wear or cause undue
friction. The arrangement of the weighted levers and spring or weight, if the

page_text: latter be prefered to a spring, may be varied in an endless variety of ways, while
at the same time the application of the steel links or toggles may be different to
that shown in the Drawing, or two sets of toggles may be used, the second set to
replace the pivots L, L¹. The button N is set to clear the projection on the short
arm of the lever, and its object is to prevent cither of the links falling out of gear
with the lever and button in case one ball or lever should inadvertently be lifted
by hand.
Having now described and indicated the nature and intent of my Invention, and
some means for carrying the same into effect, I would have it to be distinctly
understood that I do not confine myself to the exact arrangement of parts shown in
the Drawings, but what I do claim is,
-
First. The employment of a governor of the type described geared to run at
twice the speed of the engine shaft, and caused to actuate cut-off valves of suitable
types in the manner and for the purpose specified.
And, Lastly. The insertion in high speed governors of two or more steel links
between the weighted levers and the spring or weighted resistance to diminish
friction and prevent undue wear.
In witness whereof, I, the said Herbert Lindley, have hereunto set my hand
and seal, this Twelfth day of November, in the year of our Lord One
thousand eight hundred and eighty one.
Signed and sealed by the said
Herbert Lindley, in the
presence of
F. BOSSHARDT,
Of the Firm of Bosshardt & Grant,
Patent Agents,
Hopwood Avenue,
Manchester.
HERBERT LINDLEY. (LS.)