IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR REGULATING THE CUT-OFF VALVES IN STEAM ENGINES WITH THE GOVERNOR.
Year: 1875

page_text: LETTERS PATENT to Thomas Broadbent and Joseph Westerby, both
of Huddersfield, in the County of York, Engineers, for the In.
vention of
" 'IMPROVEMENTS IN THE METHOD OF AND APPARATUS FOR
REGULATING THE CUT-OFF VALVES IN STEAM ENGINES WITH THE GOVERNOR."..
COMPLETE SPECIFICATION filed by the said Thomas Broadbent and
Joseph Westerby at the Office of the Conimissioners of Patents,
with their Petition and Declaration, on the 21st January 1875,
pursuant to the 9th Section of the Patent Law Amendment Act,
1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, wе, THOMAS
BROADBENT and JOSEPH WESTERBY, both of Huddersfield, in the County
of York, Engineers, send greeting.
WHEREAS we are in possession of an Invention for "IMPROVEMENTS
IN THE METHOD OF AND APPARATUS FOR REGULATING THE CUT-OFF VALVES IN STEAM
ENGINES WITH THE GOVERNOR," and have petitioned Her Majesty to grant
unto us, our executors, administrators, and assigns, Her Royal Letters
Patent for the same, and have made solemn Declaration that we are the
first and true Inventors thereof...

page_text: t
t
NOW KNOW YE, that we, the said Thomas Broadbent and Joseph
Westerby, do hereby declare that the following Complete Specification,
under our hands and seals, fully describes and ascertains the nature of the
said Invention, and in what manner the same is to be performed in and
by the following statement:-
-
This Invention relates to certain improvements in the method of and
apparatus for regulating the supply of steam to the cylinders of steam
engines by means of a cut-off valve acted upon direct and without the
intervention of a throttle valve. In the cut-off valves in ordinary use
the variation of supply of steam is regulated by means of the governor
acting upon a combined equilibrium and throttle valve, the exact amount
of cut-off is given by hand to suit as nearly as possible the weight upon
the engine, but this weight is constantly varying and cannot be regulated
efficiently by hand.
The object of our Invention is to regulate the supply of steam and
maintain the uniform speed in accordance with the varying weight upon
the engine, and to supply that steam upon the piston at the full boiler
pressure, or at any rate much nearer that pressure than is possible with
the intervention of a throttle valve, which has a tendency to wiredraw
the steam. We accomplish this in the following manner :-At the back
of an ordinary slide valve, which is worked by a common eccentric
prepared for a cut-off, we place the ordinary cut-off valves. One of the
valves is fitted with a right-hand screwed nut and the other with a left-
hand screwed nut, which fit on to corresponding screws forming part of
the valve spindle, to which a reciprocating motion is imparted by means
of a common eccentric. On to the cut-off valve spindle and outside the
steam chest is secured a toothed segment, with the teeth a little broader
'than travel of valve, into which is geared a worm secured to a shaft
placed in a diagonal or any other convenient position. At the end of the
said shaft is a ball coupling with suitable connections to governor lever,
so that when the governor rises or lowers the shaft and worm are lifted
or lowered, which revolves the segment and lengthens or shortens the
cut-off valves, thus admitting more or less steam, as the case may be.
In order to give our Invention another advantage, so as the governor
can act more quickly on the valve, we place a pair of bevel wheels on
the governor spindle, to which motion is imparted in the usual way, with
the points of the teeth opposite to each other and the body of wheels
turned out conical. Between these wheels is placed a double-coned

page_text: :
pulley, which is connected to sliding block on governors by means of
cotters and rod passing through hollow spindle in the ordinary way.
Into these wheels is geared another wheel secured to one end of a shaft
centred in framework of governor stand. To the other end of this last-
named shaft is another bevel wheel gearing in a wheel on the aforesaid
worm shaft. When the weight is thrown off the engine begins to run a
little faster then the governors rise, and by means of lever press down
the shaft and worm, thereby lengthening the cut-off valve and admitting
less steam. If the lever does not regulate the valves to the extent
required, and the engine continues to run too fast, the governor will
continue to rise, and when the same have risen to near the full extent
the friction gear comes into operation, and causes the worm to revolve
and lengthen the valves more than can be obtained by the lever alone.
When the valves are lengthened so as to admit the requisite amount of
steam to run the engine at the proper speed, the governors will then fall
to the ordinary working height and release the friction gear, when the
governor will again act upon the valve through the lever until another
considerable variation in the load driven by the engine. Tappets can be
used instead of friction concs, but we prefer the latter as giving a more
steady motion.
We will now proceed to describe the accompanying Drawings, in which
like parts are indicated by like letters and figures.
Fig. 2 is an end view of the same shewing friction conė, level gearing,
spur segment, and worm for regulating cut-off valve.
.
Fig. 3' is a back elevation shewing angle of worm and shaft.
Fig. 4 is a plan through line A, B.
A, A, is the bed plate of a horizontal engine to which our improved
apparatus is applied'; B is the valve chest cast to and forming part of
cylinder C; C, C, are the cylinder covers;, D, the gland for piston rod
to work through; G, G, is a fixing for supporting governors F, which
revolves on spindle H in footstep H'; J is the sliding governor block, to
which is attached double friction cone K in the usual way by means of
cotters and rod, not shewn in Drawings, inside hollow spindle H;
Land L'are bevel wheels centred on spindle H, and prepared to receive
friction cone K; L³, a bevel wheel gearing into L and L' fixed on end
of shaft passing through boss G¹. To the other end of the said shaft is
another bevel wheel M gearing into M' centred on shaft N, and so
arranged that the said shaft can move. longitudinally through wheel M',

page_text: but cannot revolve only when put into motion by wheel M¹; O is a
worm secured to shaft N, and held in position by fixing P at the angle
most suitable to work into teeth of spur segment O¹, which is secured to
valve spindle O%, to which motion is imparted in the usual way.
ACTION OF APPARATUS.
R, the slide valve; and S, the cut-off valve, to which a reciprocating
motion is imparted in the ordinary way; F, the governors, which revolve
at a suitable speed so as to keep the engine regular. If some of the
machinery that the engine is driving should be taken off the engine will
begin to revolve quicker, when the governors F with block J and friction
cone K will rise until K is held tight into recess of bevel wheel L', the
friction of which will revolve wheels L³, M, and M', and worm O, which
gears into spur segment O¹ secured to spindle O, by which means will.
turn spindle and lengthen the valves, thus admitting less steam and keep
the engine at its proper speed. If the engine were revolving too slow
the governors would act in the opposite direction and shorten the valves,
admitting more steam. Lever U, one end of which is connected to
block J and works in joint U₁, the other end couples to rod U³, is
applied so as to make apparatus more sensitive and act direct upon
the worm O and segment O¹, when the governor and block J, the end of
lever U, will press ball coupling W, shaft N, and worm down a little,
by which means the spur segment O' will revolve and lengthen the
valve and admit less steam. When the governors fall the segment and
valve will act in the opposite direction.
In witness whereof, we, the said Thomas Broadbent and Joseph
Westerby, have hereunto set our hands and seals, this Twentieth
day of January. in the year of our Lord 1875.
Signed, scaled, and delivered
in the presence of
JOHN WAUGH,
Engineer and Patent Agent,
(L.S.)
THOS. BROADBENT.
JOSEPH WESTERBY. (L.S.)
Bradford,
Yorks.