Improvements in Valve Gear for Reciprocating Fluid Pressure Motors and Fluid Meters.
Year: 1887

page_text: Date of Application, 24th Dec., 1887
Complete Specification Left, 24th Sept., 1888
Complete Specification Accepted, 26th Oct., 1888
Improvements in Valve Gear for Reciprocating Fluid Pressure
Motors and Fluid Meters.
I, JOHN HENRY HOLMES of Portland Road, Newcastle-on-Tyne, in the county of
Northumberland, Electrical Engineer, do hereby declare the nature of this invetition
to be as follows:-
This invention relates to improvements in valve gear for reciprocating fluid pressure
motors such for instance as direct acting steam pumps without flywheels, or water
meters of the piston type, and has for object to ensure the moving of the valve or
valves controlling the motions of the piston, being effected at the right instants in a
rapid manner and by simple mechanical means or apparatus.
To this end, according to my invention instead of making use of some kind of fluid
pressure relay with supplementary valves or some arrangement of falling weight for
the purpose of altering the position of the main valve or valves I make use of some
simple form of spring or springs arranged in such a manner that the main valve which
controls the movements of the reciprocating piston is urged into either of its two
extreme positions solely by the force of a spring or springs in which energy for this
use has been stored by reason of the movement of the piston.
The force of the spring is exerted between a point or points moved by direct
pressure from the reciprocating piston and which point or points I call the "actuating
mechanism and a point or points rigidly connected to the valve and which point
or points call the valve mechanism" and is not exerted between the "valve
mechanism and some immoveable portion of the motor such for instance as the
cylinder.
The actuating mechanism" is arranged so as to have a somewhat larger range
of movement than is allowed to the valve mechanism so that the direction of the
force exerted by the spring upon the "valve mechanism" is altered as the "actuating
mechanism" approaches the end of its traverse because the direction of the force
passes a dead point enabling the force so to act upon the "valve mechanism" as to
urge it into the other of its two extreme positions to that which the "valve mechanism
occupied when the "actuating mechanism" commenced its stroke.
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page_text: The spring as I prefer to make it is so arranged as to always be exerting some force
between the actuating mechanism" and the "valve mechanism" tending to prevent
either the "actuating mechanism or the valve mechanism" remaining stationary at
intermediate points between the extreme limits of their travel.
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2:
The same spring it will be observed forms the medium through which force is
exerted upon the valve mechanism" for the purpose of causing it to move in either
direction, and such spring is so arranged that when the actuating mechanism is
moved from one of its two extreme positions to the other the spring taken as a whole
entirely alters its position with regard to the cylinder or other immoveable part of the
motor although the spring has in the two positions approximately the same shape or
form and is approximately in the same state of strain.
Suitable stops can he provided to limit the travel of the "actuating mechanism" and
also the travel of the "valve mechanism."
As will be obvious, valve gear to operate on the principle of my invention as above
set forth may be constructed in various forms and the spring or springs may be
straight, curved or spiral and may act as tension springs or as compression springs
and they may be situated within or external to the valve chest.
The spring or springs may act between two pivotted levers the arrangement being
such that the spring pressure tends to draw or move the levers together in either of
two directions so that when one of the levers is moved by the action of the piston
through a sufficient distance the direction of the force which the spring exerts will be
changed so as to draw or move the other lever over to the same side.
The spring or springs may act directly upon an angular shaped portion of the
"actuating mechanism" or of the valve mechanism ** or both the "actuating
mechanism :: and the valve mechanism " may be provided with angular shaped
portions pressed together by the spring so that when the "actuating mechanisin
moves, its angular portion slides up the inclined face of the angular portion of the
"valve mechanism" and as soon as the point of the angular portion of the "actuating
mechanism passes the point of the angular portion of the valve mechanism" the
motion of the former ceases as it is arrested by its stop but the latter moves in an
opposite direction into its other extreme position by reason of the pressure exerted by
the spring.
Di 51
1007

page_text: COMPLETE SPECIFICATION.
Improvements in Valve Gear for Reciprocating Fluid Pressure
Motors and Fluid Meters.
1, JOHN HENRY HOLMES, of Portland Road, Newcastle on Tyne in the County of
Northumberland, Electrical Engineer do hereby declare the nature of this inven-
tion and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:—
This Invention relates to improvements in valve gear for reciprocating fluid pressure
motors and fluid meters such for instance as direct acting steam pumps without fly-
wheels or water.meters of the piston type and has for object to ensure the moving of the
valve or valves being effected at the right instants in a rapid manner and by simple
mechanical means or apparatus.
To this end instead of making use of some kind of fluid pressure relay with supple-
mentary valves or some arrangement of falling weight for the purpose of altering the
position of the main valve or valves I make use of some simple form of spring or
springs in which energy for this use has been stored by reason of the movement of the
piston.
The force of the spring is exerted between a point or points moved by direct pressure
from the reciprocating piston, and which point or points I call the "actuating
mechanism," and a point or points rigidly connected to the valve and which point
or points I call the "valve mechanisin, and is not exerted between the "valve
mechanism and some immoveable portion of the motor, such for instance as the
cylinder.
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The "actuating mechanism" is arranged so as to have a somewhat larger range of
movement than is allowed to the "valve mechanism so that the direction of the force
exerted by the spring upon the "valve mechanism" is altered as the "actuating
mechanism approaches the end of its traverse, because the direction of the force
passes a dead point, enabling the force so to act upon the valve mechanism" as to
urge it into the other of its two extreme positions to that which the "valve mechanism
occupied when the "actuating mechanism" commenced its stroke. The spring, as I
prefer to make it is so arranged as to always be exerting some force between the
actuating mechanism" and the "valve mechanism tending to prevent either the
"actuating mechanism" or the "valve intermediate points between the extreme limits
of their travel. The same spring, it will be observed, forms the medium through
which force is exerted upon the valve mechanism" for the purpose of causing it to
move in either direction, and such spring is so arranged that when the "actuating
mechanism is moved from one of its two extreme positions to the other the spring
taken as a whole entirely alters its position with regard to the cylinder or other
immoveable part of the motor although the spring retains approximately the same
shape or form and is approximately in the same state of strain.
Suitable stops can be provided to limit the travel of the "actuating mechanism”
and also the travel of the "valve mechanism."

page_text: As will be obvious, valve gear to operate upon the principle of my invention as
above set forth, may be constructed in various forms, and the spring (or springs) may
be straight, curved, or spiral, and may act as tension springs, or compression springs,
and they may be situated within or external to the valve chest.
The spring (or springs) may act between two pivoted levers, the arrangement being
such that the spring pressure tends to draw or move the levers together in either of
two directions, so that when one of the levers is moved by the action of the piston
through sufficient distance, the direction of the force which the spring exerts will be
changed, so as to draw or move the other lever over to the same side.
moves, its
The spring (or springs) may act directly upon an angular shaped portion of the
actuating mechanism," or of the "valve mechanism," or both the "actuating
mechanism and the "valve mechanism "
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may have angular shaped portions pressed
together by spring pressure, so that when the "actuating mechanism"
angular portion slides up the inclined face of the angular portion of the "valve
mechanism and, as soon as, the point of the angular portion of the "actuating
mechanism passes the point of the angular portion of the "valve mechanism" the
motion of the former ceases, as it is arrested by its stop, but the latter moves in an
opposite direction, into its other extreme position, by reason of the pressure exerted
by the spring.
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Referring to the accompanying 3 sheets of drawings.
Figure 1. shows in section, a cylinder, piston, and rotary slide valve to which my
improved valve gear may be applied.
A represents the cylinder, 13 the piston, and C the rotary slide valve controlling the
admission and exhaust of the fluid from either end of the cylinder, in a manner well
understood.
nust however he understood, that I lay no claim to what is drawn in Fig. 1. this
drag being added merely for the purpose of making more clear the operation of
the mhanism shown in Figures 2 and 3 and Figures 4 and 5.
Further it must be understood that I do not wish to confine the application of my
improved valve gear to use with cylinders and valves of the kind drawn in Figure 1.
as it is obvious, that the gear may be applied to cylinders and valves differing there-
from, for example, the valve may move in a straight line instead of being rotary or
cocks or clack valves, might be applied instead of the slide valve.
Figures 2 and 3 show a valve gear made according to this invention in which a
spiral spring acting in tension, is made use of, for the purpose of moving the slide
valve from either end of its stroke to the other.
A represents the cylinder, D the piston rod, E a lever connected to and moving
with the piston, and turning freely upon the axis F of the rotary slide valve. G is a
lever connected to and moving with the valve, H is a spring having its end attached
to pins K. and L. upon the levers E and G, the said pins being long enough to allow
the spring to pass clear of the end of the valve spindle F. when it moves from the
position shown in Figure 2. to the position shown in Figure 3. Stops I and J are
provided to limit the movement of the lever G.
"
Referring to Figure 2., when the piston moves towards the right, the lever or
actuating mechanism" E, will move with it, stretching the spring H and storing
energy in it.
As the piston approaches the end of the stroke, the lever E will pass
into a position in line with the lever G, and the said spring is under the greatest
tension in this straight position. When the dead point, as it were, is exceeded by
further movement of the lever E, the angle between the two levers has become less
than 180 degrees, the spring contracts, and moves the valve lever G from the stop
to the stop J, thus reversing the position of the valve. The same operations take place
during the return stroke of the piston. It may be observed that the angle through
which the lever E moves, is greater than the angle through which the lever G moves,
thus giving to the pin La larger range of movement than is given to the pin K, so
that the direction of the force exerted by the spring upon the valve lever G is altered
as the actuating lever E approaches the end of its traverse and the direction of the force
passes the dead point.

page_text: Figures 4 and 5 represent a form of valve gear, according to this invention, in
which a double or sugar tongs spring, acting in compression is made use of for the
purpose of moving the slide valve from either end of its stroke to the other. As
before. A represents the cylinder D the piston rod: Ea lever connected to and
moving with the piston, and turning freely upon the axis F of the votary slide valve;
Gis a double angular shaped cam formed by the faces K Kand LL; His a flat spring
fixed at its centre to part of the lever E, this part being raised to allow for play in the
extremities of the spring, which rest on the two sets of cam-faces K. K' and L'L'. In
action, the two springs act concurrently.
Figure 4 shows the cam G and the lever E in the positions they occupy when the
piston is commencing its stroke towards the right hand. As the piston moves in this
direction, the springs are bent outwards by the angular shaped cam G formed by the
faces K K and LIA. So long as a perpendicular drawn from the face of the spring,
where it meets the angle, falls towards one side of the centre of the axis, the lever E is
impelled towards the stop I, but when the perpendicular falls to the other side of the
axis, the cam G and lever M are impelled in the opposite direction, and when the
force is sufficient, they make their stroke suddenly and rapidly, coming into
the position shown in Figure 5, in which position the lever M is held firmly against
the stop J.
Figure 5 shows the position of the parts when the piston is about to commence its
return stroke towards the left hand.
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As before a larger range of movement is allowed to the "actuating mechanism
than is given to the valve mechanism," for the purpose of enabling the direction of
the force of the springs to pass a dead point as the "actuating mechanism" approaches
the end of its traverse, in either direction, and thus allow the springs to act upon the
valve, so as to urge it into the other of its two extreme positions, to that which it
occupied when the piston commenced its stroke. It will be obvious that the positions
of the cam and springs might be reversed, the springs being upon the "valve
mechanism," and the cain upon the "actuating mechanism the latter being allowed as
before, a larger range of movement.
Figures 6 and 7. show valve gear according to this invention in which the valve is
moved to and fro in a straigih line, and not turned round a centre. The "actuating
mechanism" also moves in a straight line parallel to that in which the valve moves.
As before A represents the cylinder and D the piston rod. E is an arm projecting
from the piston rod and moving with it. I is a casting capable of sliding upon the
valve rod G, the valve rod acting as a guide for it. The amount of movement of the
casting F is limited by stops O and P. In the casting are two sockets or recesses in
which are received helical springs J. The mouths of the recesses are closed by
caps K, which are free to slide within the recesses and which partly enclose the springs.
The ends of the caps are formed into wedge shaped projections L which are pressed by
the springs against a double wedge shaped block M carried upon and fixed to the
valve rod G.
The amount of movement allowed to the valve and valve rod is limited by reason
of the valve coming up against each end of the valve chest at either end of its stroke,
and the amount of movement allowed is less than that allowed to the casting F, so
as to allow the dead points to be passed as has been described.
Assuming the parts of the apparatus to be in the positions shown in Figure 6 and
the fluid under pressure to be admitted to the valve chest the piston and piston rod
will be moved to the right hand and when they are approaching the end of their stroke
the arm E will come in contact with the collar I forming part of the casting F, and
will carry the casting F along with it. The result of this will be that the wedge shaped
caps L must recede partly within the recesses in the casting compressing the springs
and sliding up the inclined faces of the block M until the points of the wedges are in a
straight line this position of the parts being the dead point. As soon as this point has
been passed the movement of the casting F is arrested by the collar H coming
against the immoveable stop P and the springs will then force out the caps K and as
these will now act upon the right hand side of the block M this latter and with it the

page_text: valve will be forced towards the left into the position shown in Figure 7. The valve
being thus reversed the piston will commence the return stroke and on approaching
the end of its traverse the arm E will come in contact with the collar R on the
casting F carrying this casting with it and a series of operations similar to what has
just been described will take place until the various parts have again assumed the
positions as drawn in Figure 6.
Having now particularly described and ascertained the nature of my inven-
tion and in what manner the same is to be performed, I declare that what I
claim is:
First. In valve gear for reciprocating fluid pressure motors and fluid meters the
combination or application in connection with the reciprocating piston and the valve
controlling its movements of a spring (or springs) exerting force between a point (or
points) moved by the piston and a point (or points) moving with the valve, the
arrangement, being such that the valve is urged from either end of its stroke to the
other solely by energy which has been stored in the spring (or springs) by reason of
the movement of the piston, such energy being allowed to exert itself upon the valve
at the right moment owing to the direction of the force exerted by the spring (or
springs) passing a dead point as the piston approaches the end of its stroke, substan-
tially as described.
Second. The arrangements of valve gear for reciprocating fluid pressure motors
and fluid meters substantially as described with reference to and illustrated in
Figures 2 and 3, Figures 4 and 5, and Figures 6 and 7 of the accompanying
drawings.
Dated this 22nd day of Santambar 1888