Year: 1885

page_text: I, ROBERT MAJOR BAILY, Junior, of Amberley Works, Amberley Road,
Paddington, W. Engineer, do hereby declare the nature of this invention to be
as follows:
My invention relates more particularly to that class of valve gears in which a
slide valve on the back of the main valve has a variable travel but is likewise
applicable to valve gears in which separate valves are provided for the steam and
exhaust, as in the Corliss' type.
It has for its object the variation of the point of cut-off either independently
of the points of release and compression or in combination with a variation of
them.
To obtain this result I operate the expansion valve by means of a link. This
link is, at one end, connected to an eccentric, or to an overhung crank, or other
suitable moving point; so adjusted that its motion is opposite to that of the main
crank pin or piston. At the other end it has given to it by any suitable arrange-
ment a movement similar to that of the main valve but of greater amplitude. The
travel of the expansion slide varies between this latter movement (corresponding
to latest cut-off) and the former; (giving lead opening only).
In engines fitted with reversing gear the movement of the full gear end of the
expansion link is derived from the main valve spindle or from some point in the
link motion having a similar movement to the main valve, and the mid-gear end
of the expansion link is operated either from the centre of the link or from a
separate eccentric or from the engine crosshead, provided only that its motion is
always opposite to that of the piston. The resultant motion of the expansion
valve relative to the main valve is the same as that of an ordinary slide working
on a stationary valve seat.
In radial gears of the Joy type the expansion link receives at one end a move-
ment similar to that of the main valve but of greater amplitude and at the other
end a movement opposite the piston.
In engines with reversing gear the act of reversing the main valve reverses the
expansion valve also, no separate movement being required to effect this. Also if
when running, a larger amount of compression is desired, it is only necessary to
notch up the main valve to obtain it.
As will be evident my invention may be carried out in various forms.
Dated L 1
1007

page_text: I, ROBERT MAJOR BAILY, Junior, of Amberley Works, Amberley Road,
Paddington, in the county of Middlesex, 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:-
My invention relates more particularly to that class of valve gears in which a
slide valve on the back of the main valve has a variable travel but is likewise
applicable to valve gears in which separate valves are provided for the steam and
exhaust as in the Corliss type.
It has for its object the variation of the point of cut-off either independently of
the points of release and compression or in combination with a variation of them.
And in order that the nature of my invention and the manner of carrying it into
practical effect may be fully understood I append hereto three sheets of illustrative
drawings in which various applications of my invention are represented. Referring
to sheet 1, Figs. 1 to 4 illustrate the application of my invention to a horizontal
engine with ordinary slide valve, Fig. 1 being a side elevation; Fig. 2 a plan; and
Figs. 3 and 4 cross sections.
A is an eccentric keyed on the crank shaft in the same position and with the
same advance as in an ordinary non variable slide valve gear; B is an eccentric
keyed on the crank shaft opposite the crank pin; its throw or travel is equal to
twice the advance of the main valve N plus twice the advance of the expansion
slide M relative to the main valve N.
The eccentric A operates the main valve N direct as usual, and also by means of
the rod S imparts motion to the rocking or swinging lever O which is pivotted
at 1 and is of such a length that the point E sweeps at each vibration through a
distance equal to the greatest travel of the expansion slide M corresponding to
latest cut off. The pin E operates one end of the slot link D: the other end of it
is operated by the eccentric B its rod being attached at H.
The expansion valve M is worked from the link D by means of the sliding block
and rods L L shown. The position of the sliding block in the slot link D may be
varied and controlled by hand (by any usual device, such as a lever and sector, a
screw and wheel, etc:) or by the governor directly, or by a cataract cylinder
operated by the governor.
The main valve N has ports O. O. through it; these may be single as shown;
double, or treble, as may be desired; also there may be separate main and
expansion valves for each end of the cylinder to reduce clearance and waste spaces.
According to the position of the sliding block in the slot link D, the expansion
valve M has a motion varying from the movement of the point E which is similar
to that of the main valve but of greater amplitude (corresponding to latest cut off)
to the movement of the point H (corresponding to lead opening only); the exhaust
edges of the main valve remaining undisturbed.
The point H of the slot link D need not of necessity be worked by an eccentric,
but if more convenient its motion may be taken from some other moving part of

page_text: the engine, care being taken to ensure that its stroke shall be equal to twice the
linear advance of the expansion valve and its motion opposite to that of the
piston.
The lifting link or rod K which shifts the sliding block should have its centre
of motion on the same side of the centre line of. the gear as the centre I of the
rocker C; and its length should be such as to correct the error arising from the
angular movement of Č.
On the same sheet is shown my improved valve gear applied to a horizontal
engine with four valves of the Corliss type. Fig. 5. is a side elevation; Fig. 6. a
plan; and Fig. 7. a section looking towards cylinder.
The eccentric A is keyed on the crank shaft with the same angle of advance, as
if it operated a non adjustable slide of the usual type so arranged as to give the
latest cut off required. The eccentric B is keyed on the crank shaft directly
opposite the crank pin, and its throw or stroke is equal to twice the linear advance
of the steam valves.
The eccentric A is, by means of its rod, connected at F to a swinging arm or
lever C, pivotted at I, and operates the exhaust valves X X by means of the pin G
and the rods G* shown. It also, by means of the pin E operates one end of the
slot link D; the other end of the slot link is operated by the eccentric B whose
rod is attached to it by the pin H.
The steam or admission valves are worked from the link D by means of the
sliding block and rods shown.
It will be seen that, according to the position of the sliding block in the slot
link D, with respect to the points E and H where it receives its motion from the
eccentrics A and B respectively; the travel of the steam valves S S will vary and
the cut off be earlier or later as the block approaches H or E respectively; when
the motion of the admission valves corresponds with that of the point E the latest
cut off is obtained and when it corresponds with the motion of point H lead
opening only is obtained.
The movement of the exhaust valves X X remains the same for all points of
cut off.
The position of the block in the slot link D may be varied and controlled by
hand or by the governor directly, or by a cataract cylinder operated by the
governor as mentioned with reference to the previous arrangement.
The point H in the slot link D need not necessarily be operated by an eccentric
as shown; but, when more convenient, it can be worked from some other moving
part of the engine, care being taken that its motion shall always equal twice the
linear advance of the admission valves and be opposite in direction to that of the
piston.
It is to be noted also that the lifting rod or link K which shifts the sliding block
in the slot link D, should have its point of attachment T on the same side of the
motion as the point I of the swinging lever C; and, its length must be so adjusted
as to neutralize the disturbance of the motion of the slot link D caused by the
angular movement of C as before mentioned.
On sheet 2 is shown my improved valve gear applied to reversing engines.
Fig. 8. is a side elevation; Fig. 9 a sectional plan; Fig. 10. a cross section
looking towards the crank; and Fig. 11. a cross section looking towards the
cylinder of an engine fitted with reversing gear of the kind known as Stephenson's
Link Motion.
The gear operating the main valves requires no special description.
The main valves have ports OO through them which may be single or divided
according to convenience."
The expansion slides M M work on the back of the main valves N N and are
connected to the slot link D by the rods L L which carry a sliding block capable
of adjustment to any required position in the slot link D.
The slot link D is connected at E with the rocker C which is pivotted at I and
is operated from the main valve spindle by means of the rod S; the point H of the

page_text: slot link derives its movement from the eccentric B set opposite the crank as in
the case of the non reversing engine previously described. The neutral point of
the main reversing link can be, if desired, used for this purpose instead of the
separate eccentric shown. The point E has a movement similar to that of the
main valve but of greater amount or amplitude (corresponding to latest cut off)
and the point H has a motion corresponding to lead opening only.
The motion of the point H may be derived from any convenient moving part of
the engine; so long as the same stroke is used and its motion is always opposite to
that of the piston.
Fig. 12. is a side elevation partly in section; Fig. 13 a plan; and Figs. 14 and 15
are sections showing my improved gear applied to a reversing engine in which the
valve chest is above the cylinder.
The main valve gear is of the kind known as the Stephenson link motion and
requires no further description.
The slot link D is operated at E by the rocker C receiving motion from the main
valve spindle by means of the rod S. The point H in this case takes its motion
from the crosshead by means of a rod, levers W W and rod V as shown.
The action of the gear is the same as in the preceding example; and, as in that
case, by varying the position of the sliding block in the slot link D any desired
cut off can be obtained without interfering with the exhaust. Also the main valve
can be reversed without altering the point of cut off. The compression may, if
desired with the earlier cuts off, be increased by notching up the main valve without
appreciably altering the cut off.
When the engine requires to be frequently reversed, the expansion gear is left in
full gear and the engine is handled by the main valve only.
No separate reversing gear is required for the expansion valve as owing to the
motion of the full gear end of the expansion link being taken from the main
valve spindle; if the main valve be reversed, the expansion valve is reversed
with it.
My invention can be readily applied in conjunction with other well known
reversing gears such as Gooch's, Allan's, or Walschaert's but I have not considered
it necessary to give drawings of these, inasmuch as the examples illustrated and
described herein will serve to enable a competent person to apply my invention in
connection with other gears than those I have shown.
On sheet 3. Fig. 16 is a side elevation; Fig. 17 a plan; and Figs. 18. 19. and 20.
are sections showing my invention applied to an engine fitted with radial valve
gear of the type known as Joy's.
In this case as in previous examples the link D has one end operated from the
main valve spindle by the rods SS and the other from the crosshead by the
levers W W and rods V V the action being the same as in the other types
described.
Figs. 21 and 22 show a modification of this gear for engines in which it is not
required to vary the cut off while running or to do so only occasionally.
A is the main valve eccentric set as usual and having a slot D cut in its
substance in which slot the pin B operating the expansion slide can be shifted
from O to P corresponding respectively to points of latest and earliest cut off. The
pin B is fixed in any desired position by means of the jam nut K. The slot D is
the equivalent of the slot link D in the preceding examples.
Figs. 23 and 24 show a further modification that can be used when the valve
chest is on the flywheel side of the cylinder or where the slot D would fall within
the substance of the crankshaft.
A is the main eccentric, B is the expansion eccentric which is loose but is pro-
vided with a driving plate C keyed on the crankshaft. The driving plate C has a
slot D cut in it so arranged that as the block and jam nut K attaching the
eccentric B to the driver Care moved from O¹ to P¹ the centre of the eccentric B
is compelled to travel along the line OP from the point O to the point P
Corresponding to points of latest and earliest cut-off respectively.

page_text: Fig. 25 is a diagram for setting eccentrics for engines with cut off plates on the
backs of main slides whether reversing or not.
Fig. 26. is a diagram for setting the eccentrics for an engine with separate steam
and exhaust valves.
It will be understood that the motion imparted to the steam or expansion valves
is similar to that derived from an ordinary link motion gear and that where
sharpness of cut-off is required the admission ports should be double or multiple.
Having now particularly described and ascertained the nature of my said
invention, and in what manner the same is to be performed, I declare that what
I claim is:-
1. The use for operating an expansion valve in an engine of a link so applied
arranged and operated that its full gear end has a movement similar to that of the
main or exhaust valve but of different amplitude and its other end has a movement
opposite to that of the piston corresponding to lead opening only.
2. The improved valve gear for engines with separate admission and exhaust
valves in which by means of a link operated as set forth the admission may be
varied independently of the points of release and compression of the exhaust as
described with reference to and illustrated in Figs. 5. 6. and 7. of the annexed
drawings.
3. In a reversing engine the application and use of expansion gear substantially
such as described above whereby either the admission alone or the admission and
exhaust together can be varied.
4. Valve gear of the kind referred to in claim 1, constructed applied arranged
and operating as described with reference respectively to and shown in Figs. 1. 2. 3.
and 4, of the drawings.