Improvements in or relating to the Valve Gear of Fluid Pressure Engines.
Year: 1896

page_text: Date of Application, 23rd Mar., 1896
Complete Specification Left, 22nd Dec., 1896-Accepted, 13th Mar., 1897
PROVISIONAL SPECIFICATION.
Improvements in or relating to the Valve Gear of Fluid Pressure
Engines.
We MICHAEL WATSON of 5 Ashfield Terrace East in the City and County
of Newcastle-on-Tyne Engineer and JACOB GOWLAND JOICEY of 30 Bewick
Road Gateshead in the County of Durham Engineer do hereby declare the nature
of this invention to be as follows:-
Our invention is applicable to engines of various types, but more particularly to
colliery or other winding engines, in which double beat or other form of lift valves
are employed, and is designed to effect a variable cut. off, or variable amount of
steam expansion, during the whole or active part of the stroke of the engine, as
the speed attained by the engine varies, and is also designed to utilise the power of
the steam used, by facilitating its escape through the exhaust valve during the
return stroke of the engine, and thereby decrease the back pressure.
The ordinary method of working the double beat valves in a winding engine, is
by means of eccentrics on the main shaft, working through eccentric rods, a link
motion, radius rods and levers, terminating in a main lifting lever which acts by a
toe piece and either lifts the valve spindle direct, or through an intervening lever
pivotted on a pillar at the opposite side of the valve spindle.
In either of these arrangements the valve simply rises & falls with the vibrating
motion of the lifting lever.
Occasionally a tripping piece is pivotted to the steam valve spindle consisting of
a short bell-crank lever, the vertical extremity coming into contact with the toe of
the lifting lever when the valve has to be raised, and when the valve has to be
tripped the horizontal portion comes into contact, on the upward stroke, with an
interposed piece which prevents it rising further, the vertical portion is consequently
forced of the face of the toe piece, and the valve falls & closes.
Our invention consists in placing a trip block between the toe piece of the lifting
lever, and the valve spindle, or between the toe piece of the lifting lever, and any
intervening lever.
This trip block may be either hinged to the valve spindle or preferably we make
it a rectangular block fitted to a recess formed in the valve spindle, and it has a
constant reciprocating movement imparted to it, when the engine is running, by
an eccentric or some reciprocating portion of the engine, and connected to it by the
necessary rods & levers.
The movement imparted to the trip block is such, that it is sliding away from
the toe-piece during the steam admission, and back again during the exhaust or
return stroke, ready for the next steam admission..
By means of a screw or levers or eccentric or cam, we control the position of
this trip block, so as to lengthen or shorten the time of its contact with the toe of
the lifting lever, and the part of the stroke at which the valve will trip & close, is
determined by the action of the constant sliding motion, of the trip block, and its
position as temporarily fixed, in the manner described.
In starting an engine, when full power is required, 'the' trip block is in such
position that the valve spindle will simply rise & fall with the motion of the main
lifting lever, and the steam valve will be kept open almost the full stroke of the
engine

page_text: As the speed increases and less power is required, and consequently less volume
of steam, the trip block is gradually withdrawn causing the toe of the lifting lever
to clear it at some portion of its upward or downward movement, thus allowing the
valve to fall & close.
The gradual withdrawal of the trip block is continued as the speed of the engine
increases, causing the valve to fall & close earlier in the stroke, until the desired
maximum speed is attained, when just sufficient steam will be admitted to the
cylinder to overcome the resistance and maintain the speed.
The shortening or withdrawal of the trip block is effected either by a lever or
other mechanical means worked by an attendant, or automatically by a governor,
acting by its variable speed upon the screw, lever, eccentric, or cam, connected
with it.
In the case of winding engines it is desirable that by a simple movement, the
attendant may be able to throw the tripping gear out of action, so that the engine
can be reversed, and full steam put against it, to prevent an overwind in case of
emergency.
This can be secured either by a suitable arrangement of levers connected to
and moved by the reversing gear or by an independent lever worked by the
attendant.
Our improvement in working the exhaust valve consists in using a cam, in place.
of the ordinary lifting lever.
This cam is preferably formed of two true radii struck from the centre of the
rocking shaft by which it is worked, and connected by a slightly curved or inclined
face, or any other convenient form may be adopted, the larger part of the cam is
used to lift the valve, the smaller part is only intended to sustain the weight of the
valve spindle, or any intervening lever when the valve is shut, should this be found
desirable.
The cam is set, so that it has only to travel the length of the curved or inclined
face until the exhaust valve is full open, it is maintained in this position almost the
whole stroke, and returns quickly to its seat near the end of the stroke, to secure
the necessary cushioning.
This cam may he worked either by an independent weigh bar, or by the same
weigh bar as is used for working the steam valve lever, and may be set either to
lift the valve spindle direct, or through an intervening lever in the ordinary way.
A roller revolving between this cam and the valve spindle, or between the cam
and the intervening lever, may be used to reduce friction.
Only one steam valve and one exhaust valve has been named in the foregoing
description, but it will be obvious, that the arrangement is applicable to whatever
number of valves there are required to work the engine.
Dated this 21st day of March 1896.
J. G. JOICEY.
M. WATSON.
COMPLETE SPECIFICATION.
Improvements in or relating to the Valve Gear of Fluid Pressure
Engines.
We MICHAEL WATSON of 5 Ashfield Terrace East in the City and County of
Newcastle-upon-Tyne Engineer, and JACOB GOWLAND JOICEY of 30 Bewick
Road Gateshead in the County of Durham Engineer 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 is an improved arrangement of valve gear for fluid pressure
engines and is as follows.
Our invention is applicable to engines of various types but more particularly

page_text: to colliery or other winding engines, in which double beat or other form of lift
valves are employed and is designed to effect a variable cut-off or variable amount
of steam expansion during the whole or active part of the stroke of the engine, as
the speed attained by the engine varies, and is also designed to utilise the power
of the steam used in this way by facilitating its escape through the exhaust valve
during the return stroke of the engine, thereby decreasing the back pressure.
To secure the variable cut-off we place a trip block between the toe piece of the
lifting lever and the steam valve spindle, or between the toe piece of the lifting
lever, and any intervening lever.
This trip block may be either hinged to the valve spindle or preferably we make
it a rectangular block, fitted to a recess formed in the valve spindle; this block has
a constant reciprocating motion imparted to it when the engine is running by an
eccentric or some reciprocating portion of the engine these parts being connected
by the necessary coupling rods and levers.
The movement imparted to the trip block is such that it is sliding away from the
toe piece during the steam admission, and back again during the exhaust, or return
stroke ready for the next steam admission.
By means of a lever, screw, eccentric, or cam, we control the position of this
trip block so as to lengthen or shorten the time of its contact with the toe of the
lifting lever, and the part of the stroke at which the valve will trip and close, is
determined by the action of the constant sliding motion of the trip block, and its
position as temporarily fixed, in the manner described.
In starting an engine when full power is required, the toe piece is in such
position, that the valve spindle will simply rise and fall with the motion of the
main lifting lever, and the steam valve will he kept open almost the full stroke of
the engine.
As the speed increases and less power is required, and consequently less volume
of steam, the trip block is gradually withdrawn causing the toe of the lifting lever
to clear it at some portion of its downward or upward. movement, thus allowing the
valve to fall and close.
The gradual withdrawal of the trip block is continued as the speed of the engine
increases, causing the valve to fall and close earlier in the stroke, until the desired
maximum speed is attained, when just sufficient steam will be admitted to the
cylinder to overcome the resistance and give the required speed.
The shortening or withdrawal of the trip block is effected either by a lever or
other mechanical means, worked by an attendant, or automatically by a governor,
acting by its variable speed upon the lever, screw, eccentric, or cam connected
with it.
In the case of winding engines it is desirable that by a simple movement the
attendant may be able to throw the tripping gear out of action so that the engine
can be reversed and full steam put against it, to prevent an overwind in case of
emergency.
This can be secured either by a suitable arrangement of levers connected to,
and moved by, the reversing gear, or by an independent lever worked by the
attendant.
Our improvement in working the exhaust valve consists in using a cam in place
of the ordinary lifting lever.
This cam is preferably formed of two true radii struck from the centre of the
rocking shaft by which it is worked, and connected by a slightly curved or inclined
face, or any other convenient form may be adopted, the larger part of the cam is
used to lift the valve, the smaller part is only intended to sustain the weight of
the spindle or any intervening lever when the valve is shut, should this be found
desirable.
The cam is set so that it has only to travel the length of the curved or inclined
face until the exhaust valve is full open, it is maintained in this position almost the
whole stroke and returns quickly to its seat near the end of the stroke, to secure
the necessary cushioning.

page_text: This cam may be worked either by an independent weighbar, or by the same
weighbar as is used for working the steam valve lever and may be set either to
lift the valve spindle direct or through an intervening lever in the ordinary way.
A roller revolving between this cam and the valve spindle, or between the cam
and the intervening lever, may be used to reduce friction.
Only one steam valve and one exhaust valve has been named in the foregoing
description, but it will be obvious that the arrangement is applicable to whatever
number of valves there are required to work the engine.
And in order that this invention may be readily understood and carried into
practical effect we have herewith appended one sheet of drawing having the figures
thereon marked with letters of reference.
In all the figures similar parts where they occur are marked with similar figures
and references.
Fig. 1 is an elevation of the complete gear for one cylinder partly in section.
In this drawing A. A are the steam valve spindles with a recess in its upper
part in which moves the sliding block B B.
This sliding block receives a lateral movement from the crosshead or an eccentric
or some other part of the engine through a series of levers etc. and the necessary
connections, ee are eccentric straps acting in this arrangement as part of the series
of levers which oscillate upon the eccentrics D D.
The eccentrics are keyed to the shaft E, and the shaft E is connected to the
governor G which in rising gives a circular movement to the shaft E, and alters
the position of the eccentric D giving a movement to the eccentric strap C to which
the sliding block B is attached by connecting rods, thus partially withdrawing the
sliding block B from contact with the toe of the lifting lever E.
The drawing shews the apparatus in position for admitting steam to the front end
of the cylinder, and the action is as follows.
The levers X are coupled to and actuated from the eccentrics in the usual
manner.
In rising the toe F of the lifting lever comes into contact with the sliding block B
and lifts the steam valve.
The valve simply opens and closes with the motion of the lifting lever, because.
although the sliding block B receives a reciprocating motion from the engine, yet
it does not clear the toe of the lifting lever at any portion of the stroke; the engine
thus receives steam almost the full stroke until it attains nearly full speed, when the
governor begins to rise.
When the governor rises, it alters the position of the eccentrics D through the
levers and coupling rods, causing the sliding block B to clear the toe F of the lifting
lever at some portion of its downward or upward movement and thus allowing the
valve to fall and close.
The higher the governor rises the sooner the block B, is released from contact
with the toe F of the lifting lever hence the shorter is the admission of steam to
the cylinder, and the range of the governor can be made sufficient at its highest
point to altogether withdraw the block from contact with the toe of the lifting
lever and consequently entirely deprive the engine of steam, should the speed exceed
the desired maximum.
To put the governor out of action so that steam may be put against the engine to
prevent an overwind in case of emergency, we use a bell crank L with a double
concave or other suitable surface at its upper part which is pivotted on the governor
stand, the other end of the bell crank being connected to the reversing weighbar by
suitable lever and coupling rod.
The bell crank is shewn in the position it occupies when the reversing gear is in
mid position.
When the reversing gear is put over to start the engine the bell crank assumes
one or other of the positions shewn in dotted lines.
The action of this is as follows:-
Should the governor be at the top or in any intermediate position when it is

page_text: necessary to reverse the engine; the concave surface of the upper part of the bell
crank closes upon a roller M carried by the governor sleeve, and depresses the
governor thus forcing the trip blocks into position for carrying steam the full stroke
of the engine, and enabling the attendant to put steam against the engine, when the
action of reversing is completed.
In cases where a governor is not employed the trip gear can be manipulated by
the attendant, through a lever attached to the weighshaft E.
If preferred the combined motions acting on the block from the engine and from
the governor, or from the hand lever may be transferred through a system of
differential levers as shown in Fig. 2 in which S is the rod transmitting the motion
from the engine. T is the rod transmitting the motion. from the governor, or from
the hand lever, U is the differential bar or lever, and V the rod transmitting the
differential motion to the block.
It will be obvious that the rod T can be actuated from the governor either by
means of a lever, eccentric, cam, or suitable pitched screw.
A suitable spring may be interposed between the trip block and the actuating.
part of the mechanism if required.
The cam H for working the exhaust valve has two surfaces, both being true
radii from the centre of the weigh bar I and connected by a curved or inclined
face.
When the cam is oscillated the larger part coming into contact with a roller
which is carried by a pin in the exhaust valve spindle raises the valve and
retains it full open during the exhaust stroke just allowing it to return to its.
seat at the time required to secure the necessary cushioning in the steam cylinders.
The smaller part of the cam is only intended to support the weight of the valve
spindle during the time the valve is closed.
It will be obvicus that any arrangement of intervening levers may be placed
between the exhaust valve spindle and the cam, the sole point to be secured being,
that the exhaust valve shall be rapidly opened and kept full open for a sufficient.
time to enable the steam to escape quickly and thus reduce the back pressure.
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
1st. The method of cutting off steam at any part of the stroke by means of a.
motion imparted from some suitable part of the engine together with a motion.
imparted from the governor both acting upon the sliding block.
2nd. The method of cutting off steam at any part of the stroke by means of a
motion imparted from some suitable part of the engine together with a motion.
imparted from a hand lever or controlling lever both acting upon the sliding
block..
3rd. The method of depressing the governor so as to throw the trip gear out of
action by means of a bell crank with double concave or other suitable surface-
actuated either from the reversing weighbar or by a hand lever substantially as
described.
4th. The method of exhaust valve action effected by means of cams substantially
as described as applied to winding engines.
5th. The several constructions and combined arrangements of parts embodying.
our improvements in or relating to the valve gear of engines substantially as and
for the purposes herein set forth and as illustrated by the accompanying drawings.
Dated this 21st day of December 1896.
J. G. JOICET.
MICHAEL WATSON.