Improvements in the Valve Gear of Steam Engines.
Year: 1888

page_text: Date of Application, 24th Apr., 1888
Complete Specification Left, 23rd Oct., 1888
Complete Specification Accepted, 23rd Nov., 1888
Improvements in the Valve Gear of Steam Engines.
1, JAMES DES BRISAY of the Town of Vancouver, British Columbia, in the
Dominion of Canada, Machinist, do hereby declare the nature of this invention to be
as follows:-
The object of this invention is to provide an improved valve gear for steam engines'
by which one, two, or more cylinders are controlled by a single rotating valve, so
that the improvement is specially adapted for locomotive engines.
The Invention consists of a rotary valve provided with ports arranged in such a
manner that one cylinder takes steam at one end and exhausts at its other end while
the other cylinder exhausts at the corresponding end and takes steam at its other
end.
The improved valve gear can be adapted to nearly all classes of steam engines, but
is principally intended for a locomotive engine, in connection with which, I have
described it, in which case the ports leading to the cylinders are contained in the
saddle connecting the cylinders and supporting the end of the boiler. These ports
open through the seat of the rotary valve, the ports being radial to the axis and at
right angles to each other. The rotary valve is mounted on a horizontal axis and is
held up to its seat by any suitable means. It has four ports in its face at equal
distances apart, two diametrically opposite ports being the steam ports opening
through the circumference of the valve to the steam chest whilst the other two
opposite ports lead to a central passage coinciding with the exhaust passage in the
saddle leading to the blast pipe. The rotary valve is fast on the end of a horizontal
shaft driven by the crank axle with which it is connected through reversing gear.
For this purpose the other end of the shaft is received in a sleeve and connected
therewith by a pin and spiral groove. The sleeve is supported in a hearing and is
adapted to turn with and slide upon a second shaft driven by bevel gear from the
crank axle, the ratio of the gearing being such that the axle makes two revolutions
to one of the shaft. The sleeve operated by suitable means such as a forked lever

page_text: The rotary valve controls both cylinders as if two valves were used, and as it makes
only one revolution to two of the axle, the steam is alternately admitted to, and
exhausted from, the ends of the cylinders in the usual order.
In order to prevent mutual interference of the exhaust from the two cylinders, the
central exhaust passage in the valve may be divided. Instead of an exhaust passage
in the valve seat and saddle, the valve stem may be hollow and the exhaust pipe
connected therewith.
Slightly modified valves to be used with a single cylinder have respectively four and
two opposite ports for admitting and exhausting steam.
The back of the valve may have a cylindric off-set surrounded by a loose ring fitted
in a cylinder formed in the steam chest cover, springs being applied against the ring
so as to hold the valve up to its scat.
J. DES BRISAY.
By A. M. & Wm. Clark,
53, Chancery Lane, London,
Patent Agents.

page_text: I, JAMES DES BRISAY, of the Town of Vancouver, British Columbia, in the
Dominion of Canada, Machinist, 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:-
The object of this invention is to provide an improved valve gear for steam engines
by which one, two, or more cylinders are controlled by a single rotating valve, so that
the improvement is specially adapted for locomotive engines.
The invention consists of certain parts and details and combinations of the same, as
will be fully described hereinafter and then pointed out in the claim.
Reference is to be had to the accompanying drawings forming a part of this specifi-
cation in which figure 1 is a sectional plan view of the improvement; Figure 2 is a
vertical cross-section of the same on the line of figure 1; Figure 3 is a like view
of the same, on the line y-y of figure 1; Figure 4 is an enlarged sectional plan view
of the rotary valve and its connections; Figure 5 is a face view of the same, with
parts in section; Figure 6 is a sectional plan view of a modified form of the improved
rotary valve; Figure 7 is a side elevation partly in section, of part of the reversing
mechanism Figure 8 is a sectional end elevation of the same on the line ww of
figure 7 Figure 9 is a like view of the same, on the line ve of figure 7; Figures 10
and 11 are face views of rotary valves of modified form, and figure 12 is a plan view
partly in section of a modified form of a rotary valve. Similar letters of reference
indicate corresponding parts in all the figures.
The improved valve gear can be adapted to nearly all classes of steam engines, but
is principally intended for a locomotive engine in connection with which I have
illustrated it in the drawings.
A, B, are the steam cylinders, C, D, their pistons, E the driving wheel axle.
F, F the crank pins, all as usual. The saddle G carries the steam chest H into which
leads the steam pipe K. a, b, c, d, are the ports or passages of the two cylinders.
They are formed in the saddle G connecting the cylinders A, B, and serving as a rest
for one end of the locomotive boiler. The poris a, b, c, d, open out at the valves
at G against which the inner face of the rotary valve I is held, the axis of said valve
being horizontal and supported in bearings on the cover H' of the steam chest H. The
valve I is held up to its seat G by any suitable means, such as shewn in figure 1 or such
as illustrated in figure 12. The openings of the ports a b c d in the seat Gare arranged
radially in relation to the axis of the valve 1, the opening of the port a being at right angles
to that of the port and that of the port cat right angles to that of the port d, as
illustrated in figure 3. The valve I has in its face, four ports or openings e, f, g, h,
placed at equal distances apart and diametrically opposite each other as illustrated in
figure 2. The two opposite steam ports open through the circumference of the
valve to the steam chest H. The two exhaust ports e, g, lead into the central exhaust
passage I which coincides with the exhaust passage G in the saddle G leading to the
blast pipe J. The valve 1 is fast on the end of a shaft L driven by the axle E with

page_text: winen it is connected_ough
For this purpose, the
received in a sleeve N, a pin L' on the shaft engaging in a spiral groove N¹ formed in
the sleeve N. The latter is supported in a bearing in a cross-piece O¹ of the main
frame O and is adapted to turn with and slide upon a shaft P mounted in another
cross bearer 02 near the main axle E. and geared by a bevel wheel Q with a bevel
pinion R fast on the axle E, the ratio of the wheel and pinion being as 2 to 1,
so that the axle E makes two revolutions to one of the shaft P. The sleeve N receives
a to and fro sliding motion by suitable means, such as a forked lever engaged between
shoulders around the sleeve N, as shewn in figure 1.
The operation is as follows:-The steam passes from the steam chest through the
ports and through the ports a, b; c; d, in the usual order, the steam exhausting
through the ports a, b, c, d, also in the usual order, and through the
exhaust ports g, e, of the valve which communicate with the central exhaust
passages 1, G, leading to the blast pipe J, as above described.
The rotary
motion of the valve I therefore controls both cylinders A and B in the same manner
as if two valves were used, one for each cylinder. As the valve I makes but one
revolution to two of the axle E, the steam is admitted alternately to the respective
ends of the two cylinders A and B with the corresponding exhaust.
In order to reverse the engine, the sleeve N is slid along so that its spiral groove N¹
acting on the pin L' causes the shaft L to make one-quarter of a revolution indepen-
dently of the rest of the engine, so as to alter the relative position of the ports in the
valve I and its seat independently of the crank axle, thus reversing the engine.
In order to prevent mutual interference of the exhaust from the two cylinders, I
provide the valve I with a central partition I, as illustrated in figure 4, so that the
exhaust is directed into the exhaust passage G. Instead of the exhaust passage G
being in the saddle G, I may make the stem of the valve hollow and connect the
exhaust pipe J therewith, as shewn in figure 6, so that the exhaust steam will pass
therethrough.
i
The valve I, as illustrated in figure 10, can be used for a single steam cylinder so
that two opposite ports ii permit the steam to cuter the ends of the cylinder alter-
nately, while the ports exhaust alternately. The valve as illustrated in figure 11,
which is for the same purpose, is provided with only two ports of which one is
an inlet port and the other an exhaust port. As illustrated in figure 12, the back of
the valve I is provided with a concentric offset S surrounded loosely by a ring T fitted
to slide in a cylinder U formed in the interior of the head V of the steam chest,
springs W being applied to exert pressure against the back of the ring T, so as to hold
the valve I to its seat G¹.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a valve gear for steam engines, two locomotive cylinders provided with the
usual ports leading to a common valve seat, and arranged in such a manner that the
two ports of one cylinder stand at right angles to each other, in combination with a
rotary valve operating on the said valve seat and provided with two inlet ports placed
opposite each other, and two exhaust ports placed similarly, and at right angles to the
other ports, substantially as shewn and described.
2. In a valve gear for steam engines, two locomotive cylinders provided with
the usual ports leading to a common valve seat, and arranged in such a manner
that the two ports of one cylinder stand at right angles to each other, in combi-
nation with a rotary valve operating on the said valve seat and provided with
two inlet ports placed opposite each other, and two exhaust ports placed similarly
and at right angles to the other ports, and means substantially as described, for
imparting a rotary motion to the said valve from the main driving shaft, so that
the latter makes two revolutions to one revolution of the said valve, as set forth.
3. In a valve gear for steam engines; two cylinders provided with the usual
ports leading to a common valve seat and arranged in such a manner that the

page_text: two ports of one cylinder stand at right angles to each other, a steam chest formed
around said valve seat, and a steam inlet connected with the said steam chest, in
combination with a valve caused to rotate on the said valve seat in the said steam
chest, said valve being provided with inlet ports placed diametrically opposite each
other and leading from the interior of the steam chest to the valve seat, said
valve being also provided with two outlet ports placed opposite each other and
leading from the valve seat to a central opening connected with the exhaust pipe,
substantially as shewn and described.
4. In a valve gear for steam engines, the combination with a main shaft or
axle, of a second shaft connected with the said main shaft or axle, so that two
revolutions of the latter impart one revolution to the said second shaft, a sleeve adapted
to turn with, and slide upon, the said second shaft, said sleeve being provided
with a spiral groove, a pin projecting into the spiral groove, and a shaft carrying
the said pin, and also carrying the valve of the steam engine, substantially as
shewn and described.
5. In a valve gear for steam engines, the combination, with a valve adapted to
rotate on its seat and having a concentric partition, of a ring held on the said
concentric partition and pressing against the said valve by means of springs,
substantially as shown and described.
6. In a valve gear for steam engines, the combination, with a shaft (connected
with the main shaft or axle of the engine) of a sleeve having a spiral groove
and adapted to slide upon, and turn with, the said shaft, a second shaft carrying
a pin projecting into the said spiral groove of the sleeve, said second shaft also
carrying the valve of the steam engine, and means substantially as described, for
imparting a forward and backward sliding motion to the said sleeve, in order to
reverse the engine, as set forth.
7. The combination with the cylinders A, B, the saddle G provided on its inner
end with the valve seat G₁, and the ports a, b, c, d, leading respectively from the
said cylinders to the said seat, and the steam chest H on the inner end of the
saddle and provided with a steam inlet and the cover H³, of the rotary valve
having a horizontal axis, opposite exhaust ports eg leading from the face of the
valve inward to the central exhaust passage, and the opposite inlet ports f leading
from the face of the valve to opposite points in the periphery, and communicating
with the steam chest, substantially as set forth.
8. In a valve gear for locomotives, the rotary valve I having exhaust passages
or cavities I separated by a central partition 1 and leading from the face of the
valve to opposite sides of the said partition, and the inlet ports leading from the
periphery of the valve through its face, substantially as set forth.
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