IMPROVEMENTS IN VALVES AND VALVE-GEAR FOR MOTIVE-POWER ENGINES, PUMPS, BLOWERS AND EXHAUSTERS
Year: 1883

page_text: LETTERS PATENT to James Aimers and James Tinline both of Galashiels in
66
the County of Selkirk North Britain for an Invention of "IMPROVEMENTS
IN VALVES AND VALVE-GEAR FOR MOTIVE-POWER ENGINES, PUMPS, BLOWERS
AND EXHAUSTERS
"
PROVISIONAL SPECIFICATION left by the said James Aimers and James
Tinline at the Office of the Commissioners of Patents on the 12th January
1883.
JAMES AIMERS and JAMES TINLINE, both of Galasbiols in the County of
Selkirk North Britain, "IMPROVEMENTS IN VALVES AND VALVE-GEAR FOR
MOTIVE POWER ENGINES; PUMPS, BLOWERS AND EXHAUSTERS,"
This Invention relates to improvements in valves and valve-gear for motivo
power engines, such as steam and water engines, and for pumps and apparatus for
forcing, blowing or exhausting air, gas, or other fluids.
The improvements comprise a novel construction and arrangement. of rotating
valve for controlling the admission and exhaust or discharge of the steam or other
fluid, actuating motive-power engines, or passing through pumps, blowers or
exhausters; and, in steam engines, the combination with such valve of a cut-off
valve and valve-gear for cutting off the admission of steam at any part of the
stroke, the action of such valve gear being controlled by the governor, so that the
power developed may correspond exactly with the load on the engine.
In carrying out the Invention, as applied to steam engines, the steam inlet and
exhaust ports are specially formed to suit the improved rotating valve, or in the
case of old engines, the port face of the cylinder is covered by a plate in which
the special ports are cut. The exhaust port is as usual placed centrally, and is
circular, while the steam inlet ports are made segmental, or in the form of segments
of an annulus whose centre coincides with the centre of the exhaust port.
The improved rotating valve which controls the admission of the steam to these
ports, is disc shaped, and is fitted to bear on the port face, and is keyed on a
spindle whose axis is in line with the centre of the exhaust port of the cylinder.

page_text: A single steam admission port is cut through the valvo disc at one side of its
centre, to coincide in shape and in position with one of the segmental inlet ports
of the cylinder. An exhaust port or recess is formed in the bearing face of the
disc, (but not through it) by cutting out a larger segment than is cut for the inlet
port, and forming in communication with this segmental recess, a central circular
recess directly opposite the exhaust port in the cylinder face.
The valve spindle is rotated by means of bevel gearing or other means from the
governor spindle or other rotating shaft operated by the engine; and during the
rotation of the valve the inlet and exhaust ports or passages in it alternately pass
over each inlet port of the cylinder, while the exhaust passage in the valve is
continuously open to the exhaust port of the cylinder.
The rotating valve can be so fitted on the cylinder face as to obtain any desired
extent of "lead," and the exhaust passage is by preference formed to ensure free
escape of the exhaust steam from one end of the cylinder before the inlet port is
open to admit steam to the other end, while both the admission and the exhaust
ports are full open at or about half stroke of the engine.
To provide means for reversing the engine, one of the wheels of the bevel gear
driving the valve spindle may be put out of gear to enable the valve to be shifted,
or two bevel wheels may be fitted free to slide on the valve spindle, one on each
side of the driving wheel on the governor spindle, and be connected to a hand
lever, so that the wheel on one side may be put into gear, while the other is thrown
out of gear, (as in ordinary clutch arrangements) to reverse the motion of the
valve.
In combination with the steam distributing valve described is fitted a cut-off
valve, which consists of a flat disc fitted on the back of the rotating valve, and
having cut through it two segmental ports directly. opposite the two inlet ports of
the cylinder. This valve disc is carried by a hollow shaft passed over the rotating
spindle of the distributing valve, and passing out by a stuffing box in the cover
of the steam chest which encloses both valves. To the outer end of the hollow
shaft is fitted a lever arm connected to a spring or dash pot, by which the cut-off
valve is kept in a normal position in which the steam ports are closed. The
cut-off valve disc is however brought round to a position in which the ports in it
are opposite the valve inlet port and the inlet ports of the cylinder, or immediately
before the commencement of each stroke, by means of cams or wipers fitted on
the rotating spindle of the distributing valve, and the valve disc is brought back
with a rapid movement to cut off the admission of steam at any part of the stroke
by means of the spring, immediately the cams pass.
The cams are not however arranged to act directly on the lever on the hollow
shaft, but on a plate fitted to slide on a long forked lever or levers connected to
the spindle lever arm, and fitted to oscillate on a fixed centro. The sliding plate
on which the cams act is moved by means of the usual sliding collar of the
governor acting through a bell-crank or other lever, and as the governor balls rise
or fall in accordance with the speed of the engine, the sliding plate is corre-
spondingly moved closer to or further from the cams. The length of time during
which the oscillating lever carrying the sliding plate, is raised by the cam, and
consequently the duration of the opening of the ports of the cut-off valve depends
on the proximity to the actuating cams of the sliding plate on which the governor
acts. The cams can be set at starting to clear the plate at a mean position, and
cause the spring to act on the valve disc and cut-off the steam at any part of the
stroke that may be desired; and the action of the governor on the sliding plate
will then, by causing the valve to cut-off earlier or later, compensate for variations
in the speed of the engine. The oscillation of the cut-off valve by the action of
the spring, is by preference in the direction opposite to the rotation of the
distributing valve, so that the cutting off of the steam may be effected as rapidly
as possible.
For small engines running at a high speed, and where simplicity of parts is
desirable, the cut-off plate at the back of the distributing valve may be onerated.

page_text: direct from the governor without the intervention of the oscillating lever, sliding
plate and spring or dash pot. The lever arm on the hollow shaft of the cut-off
plate is then connected to a lever operated by the governor. The period of cut-off
can be altered according to the load upon the engine, and the full benefit of
expansion is obtained; instead of the steam being wire-drawn as is the case when
the governor acts on a throttle valve.
In applying the improvements to motive power engines operated by water
pressure, or to steam engines in which expansive working is not desired, the
cut-off valve and valve gear described may be dispensed with, and the improved
distributing valve is then used alone.
The same arrangement without the cut-off valve is applicable to blowers and
exhausters and to pumps, and when the improved rotating valve is fitted both to
the motive-power cylinder and to the water cylinder or barrel of a direct-acting
pump, or to the corresponding cylinders of blowers and exhausters when combined
with an actuating cylinder, the distributing valves of both cylinders in each case
may be rotated by gearing from the same counter shaft.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said James Aimers and James Tinline in the Great Seal Patent Office
on the 12th July 1883.
JAMES AIMERS and JAMES TINLINE, both of Galashiels, in the county of
Selkirk, North Britain, "IMPROVEMENTS IN VALVES AND VALVE GEAR FOR
MOTIVE-POWER ENGINES, PUMPS, BLOWERS, AND EXHAUSTERS.
"
Our said Invention relates to improvements in valves and valve-gear applicable
for motive-power engines, such as steam and water engines, and for pumps and
apparatus for forcing, blowing, or exhausting air, gas, or other fluids.
The improvements comprise the construction and arrangement of a rotating
valve, for controlling the admission and exhaust or discharge of the steam or other
fluid, actuating motive-power engines, or passing through pumps, blowers, or
exhausters; and the combination with such valve of a cut-off valve and valvo
gear for cutting off the admission of steam at any part of the stroke, the action
of such valve gear being controlled by the governor, so that the power developed
may correspond exactly with the load on the engine.
The accompanying Drawings illustrate several modifications of our Invention.
Figures 1 and 2 on Sheet 1 are respectively a sectional side elevation and an end
elevation of part of a steam engine; showing the improved valves and valve gear
applied. Figures 3, 4 and are respectively a vertical section, a horizontal section,
and an end elevation of an engine, fitted with a modified arrangement of the cut-off
valve gear. Figures 6 and 7 are detailed views of the steam distributing valve,
and Figures 8 and 9 similar views of the improved cut-off valve or plate.
Figures 10 and 11 on Sheet 2 are front and side elevations, and Figure 12 is a
horizontal section of the valve chest of a steam engine, showing another modifi-
cation of the improvements. Figures 13, 14, 15, 16, 17, 18 and 19 are detached
views of details. Figure 20 is an elevation of a slightly modified arrangement of
the valve gearing. Figure 21 shows the port face of an old engine, or the plate
which is fitted thereon to adapt it for the improved valve arrangements; and
Figuro 22 shows the improved cut-off valve as used in combination with the
ordinary slide valve.
In carrying out the Invention as applied to steam engines, the steam inlet and
exhaust ports a, a¹ of the cylinder A, are specially formed to suit the improved
rotating valve, or in the case of old engines, the port face A' of the cylinder is
covered by a plate A', in which the special ports are cut. The exhaust port a¹ is
as usual placed centrally, and is circular, while the steam inlet ports a are made
segmental, or in the form of segments of an annulus whose centre coincides with
the centre of the exhaust port.
The rotating valve B which controls the admission of the steam to these ports, is
disc shaped, is fitted to bear on the port face A' of the cylinder, and is keyed on a
spindle B' whose axis is in line with the centre of the exhaust port a' of the
cylinder A. A single steam admission port b is cut through the valve disc at one
side of its centre to coincide in shapo and in position with one of the segmental
inlet ports a of the cylinder. An exhaust port or recess b' is formed in the bearing
face of the disc B (but not through it) by cutting out a larger segment than is cut
for the inlet port, and forming in communication with this segmental recess b¹, a
central circular recess 6 directly opposite the exhaust port a' in the cylinder face.
The valve spindle B' is rotated by means of bevil gearing D or other means from
the governor spindle D₁ or other rotating shaft operated by the engine; and during
the rotation of the valve B3, the inlet and exhaust ports or passages b, b', in it
alternately pass over each inlet port a of the cylinder, while the exhaust passage b²
in the valve is continuously open to the exhaust port a¹ of the cylinder.

page_text: The rotating valve can be so fitted on the cylinder face as to obtain any desired
extent of "lead," and the exhaust passage b', 63, is by preference formed to ensure
free escape of the exhaust steam from one end of the cylinder A, before the inlet
port is open to admit steam to the other end, while both the admission on one side,
and the exhaust port on the other are full open at or about half stroke of the
engine.
To provide means for reversing the engine, one of the wheels D of the bevil gear
driving the valve spindle may be put out of gear to enable the valve to be shifted,
or two bevil wheels may be fitted free to slide on the valve spindle B¹, one on each
side of the driving wheel on the governor spindle, and be connected to a hand lever
so that the wheel on one side may be put into gear while the other is thrown out
of gear (as in ordinary clutch arrangements) to reverse the motion of the valve.
In combination with the steam distributing valve described is fitted a cut-off
valve, which consists of a flat disc C, fitted on the back of the rotating valve B, and
having cut through it two segmental ports c, c, directly opposite the two inlet
ports a, a, of the cylinder A. This valve disc C is carried by a hollow shaft C'
passed over the rotating spindle B' of the distributing valve B, and passing out by
a stuffing-box in the cover of the steam chest A², which encloses both valves. To
the outer end of the hollow shaft C¹ is fitted a lever arm E, connected to a spring
or dash-pot F. by which the cut-off valve is kept in a normal position in which the
steam ports are closed. The cut-off valve disc C, is however brought round to a
position in which the ports c, c, in it are opposite the valve inlet port, and the inlet
ports a, a, of the cylinder A (or immediately before the commencement of each
stroke) by means of cams or wipers G fitted on the rotating spindle B¹ of the
distributing valve; and the valve disc is brought back with a rapid movement to
cut off the admission of steam at any part of the stroke by means of the spring or
dash pot F, immediately the cams pass. The cams are not however in general
arranged to act directly on the lever E on the hollow shaft C, but on a plate E'
fitted to slide on a long forked lever or levers E² connected to the spindle lever
arm E, and fitted to oscillate on a fixed centre E³. The sliding plate E on which
the cams G act is moved by means of the usual sliding collar of the governor H,
acting through a bell-crank or other lever H³, and as the governor balls rise
or fall in accordance with the speed of the engine the sliding plate E' is corre-
spondingly moved closer to or further from the cams G. The length of time during
which the oscillating lever E carrying the sliding plate E' is raised by each cam G,
and consequently the duration of the opening of the ports c of the cut-off valve Ć
depends on the proximity to the actuating cams G of the sliding plate E¹ on which
the governor acts. The cams G can be set at starting to clear the plate E' at a
mean position, and cause the spring F to act on the valve disc C and cut off the
steam at any part of the stroke that may be desired; and the action of the
governor on the sliding plate E' will then, by causing the valve to cut off carlier
or later, compensate for variations in the speed of the engine. The oscillation of
the cut off valve C, by the action of the spring F is by preference in the direction
opposite to the rotation of the distributing valvo B, so that the cutting-off of the
steam may be effected as rapidly as possible.
For small engines running at a high speed, and where simplicity of parts is
desirable, the cut-off plate C at the back of the distributing valve B may be
operated direct from the governor, as is shown in Figures 3, 4 and 5, without the
intervention of the oscillating lever, sliding plate and spring or dash pot. The
lever arm E on the hollow shaft C₁ of the cut-off plate C is then connected to a
bell crank lever H¹ operated by the governor H. The period of cut-off can be
altered according to the load upon the engine, and the full benefit of the expansion
is obtained, instead of the steam being wire-drawn, as is the case when the governor
acts on a throttle valve. The link H³ connecting the lever E to the bellcrank H'
is provided with a screw coupling to admit of the relative position of the parts
being varied.
In the arrangement of the improved valves and valvo gear illustrated in

page_text: Figures 10, 11, and 12, the cut-off valve which is operated by the dash-pot F'aud
the cams G acting on the lever E is kept out of action, or allowed to act, by
means of locking devices shown detached in Figures 13, 14, 15 and 16, which are
acted on by the governor. The dash pot connecting rod F¹ is jointed as in the first
modification to the lever E, and to the cut-off valve lever arm E, which in this
case is made in the form of a disc I on the hollow spindle, and this disc I would bo
acted on by the dash pot F, as soon as the rotating cams G passed the plate E' on
the lever E. The disc I is however fitted with springs i, which pass through
Blots in an oscillating plate I', and engage in catches is on a fixed disc or plate 12.
The oscillating plate I is connected by levers H, H², to the governor sliding
collar H, and as the governor collar rises or falls according to the speed of the
engine, this sliding plate I is oscillated. The oscillation of the plate I' brings
bevilled surfaces 13 at the ends of the slots over the springs i, and by depressing
those springs frees them from the engaging catches . Thereupon the disc I,
being released is acted upon by the dash pot F and partially rotates the hollow
spindle C on which it is fixed, and brings the ports in the cut-off valve C out of
line with those in the distributing valve B, thereby cutting off the steam.
In the case of engines of large size, it is preferred to interpose between the
cut-off valvó C and the distributing valve B, a fixed plate C³, provided with a
large number of narrow ports c³, and hollowed or dished out underneath at c³, to
allow the steam passing through the ports c³, to find its way freely to the inlet
ports b of the valve B. The cut-off valve or plate C is then formed with ports c
corresponding in number and size with the ports in this plate C, as indicated in
Figures 17, 18, and 19. A very slight movement of the cut-off valve is in this
case sufficient to cover or uncover the ports c² to admit or cut off the supply of
steam, and friction of the valve faces is also largely avoided. The plate C² is
secured in position by bolts which also secure holding pieces C³ on each side, by
means of which the oscillating cut-off plate C is retained in place. In this
arrangement the valve-spindle B¹, and the governor spindle are driven by means of
tooth gearing J and D from the rotating cain shaft.
In Figure 20 the lever E' acted on by the cams G, passes through an eye fin
the rod F¹ connecting the dashpot F to the oscillating plate I, but otherwise the
arrangement is similar to that just described.
In Figure 22 is shown an application of the improved cut-off valve C in com-
bination with an ordinary slide valve K. The valve C is fitted within the usual
valve chest K¹, and the oscillating spindle C¹ passes out through a stuffing-box,
and is connected to and operated by a lever from the governor direct, or by any of
the arrangements of valve gear described and illustrated. A stationary dished
plate Cs formed with ports c², corresponding to those in the cut-off valve C, is
interposed between the slide valve K, and the cut-off plate C.
In applying the improvements to motive-power engines operated by water
pressure, or to steam engines in which expansive working is not desired, tho cut-off
valve and valve gear described may be dispensed with, and the distributing valve
is then used alone. No claim is however made for the rotating valve per se.
The same arrangement without the cut-off valve is applicable to blowers and
exhausters and to pumps, and when the improved rotating valve is fitted both to
the motive-power cylinder and to the water cylinder or barrel of a direct-acting
pump, or to the corresponding cylinders of blowers and exhausters when combined
with an actuating cylinder, the distributing valves of both cylinders in each case
may be rotated by gearing from the same counter-shaft.
Having now described the nature of our said Invention and the manner in
which the same is to be performed, we declare that what we claim as our
Invention is,
First. The arrangement and combination of parts of valves and valve-gear of
motive-power engines, substantially as herein described and illustrated, and for the t
purpose set forth.
Second. In motive-power engines, the combination of the rotating valve B and

page_text: cut-off valve or plate C operated directly or through levers from the governor,
substantially as heroin described and illustrated.
Third. In motive-power engines the cut-off valve or plate C fitted in combi-
nation with a rotating or sliding steam distributing valve, with or without a grid
plate interposed, substantially as herein described and illustrated.
Fourth. In motive-power engines, the combination of the cut-off valve or
plate C on an oscillating spindle or disc connected to a spring or dash-pot, which is
brought into action by the engine governor, substantially as herein described and
illustrated.
In witness whereof we, the said James Aimers and the said James Tinline,
have hereunto set our hands and seals, this Tenth day of July, in the year of our
Lord One thousand eight hundred and eighty-three.