Improvements in High Speed Steam Engines.
Year: 1898

page_text: Date of Application, 14th May, 1898-Accepted, 9th July, 1898
COMPLETE SPECIFICATION.
Improvements in High Speed Steam Engines.
I, PETER BROTHERHOOD, of 15 and 17, Belvedere Road, Lambeth, in the County
of Surrey, 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 to the construction of steam engines especially adapted for
working at high speed, as I shall describe referring to the accompanying drawings.
Figure 1 is a front elevation partly sectional, and Figure 2 is a transverse
section through one of the cylinders, of a single acting engine according to my
invention. Figure 3 is a longitudinal section and Figure 4 is a transverse section
through the high pressure cylinder of a compound double acting engine.
Referring first to Figures 1 and 2, a pair of single acting cylinders A are fixed
on a hollow top frame B with the cavity of which both cylinders communicate
through side ports B₁ and from which a pipe B leads to the exhaust. Each
piston rod A¹ is attached to a cylindrical crosshead A2 connected by double links C¹¹
to a crank pin C formed between two eccentric discs C as part of the main shaft S.
The two cranks are opposite to each other. The crosshead A is guided by two
arms Deach of which has a concave segmental end D¹ fitted to work on the
crosshead, and a convex segmental end D³ which rolls on a guide D3 and has a
pair of lateral pins linked by rods D¹ to pins D5 on the base of the engine.
Each cylinder A has above it a cylindrical side cavity fitted with a hollow piston
slide valve E having two sets of ports corresponding to lateral ports through the
wall of the cavity, these ports opening into an annular cavity E¹, communicating
with the cylinder. Each slide valve E is attached to a pair of rods E2 which pass
through suitably bushed holes of the cylinder cover, the piston and the bottom of
the exhaust cavity B, to a crosshead F, which is guided on the piston rod A¹ and
is worked by a pair of rods F1 from the eccentric discs C on the main shaft.
Steam is supplied by a pipe G¹ to a jacket G which surrounds the cylinder and
communicates with the jacket G2 surrounding the slide case. When the slide-
valve is moved so that its ports coincide with the lateral ports of the slide case,
steam is admitted to the annular cavity E¹ and to the cylinder above the piston;
when the piston in its descent uncovers the lateral ports B¹ the steam mostly
escapes into the exhaust cavity B, there being left in the cylinder and the
cavity E steam which, on the ascent of the piston forms a cushion, that may be
at the pressure of the steam entering for the succeeding stroke.
The
On the end of the main shaft S, is fixed the governor S¹, acting on a bell crank
lever S, which is linked through a rod having an adjustable spring to the short
arm of a bell crank S³ mounted on a bracket projecting from the slide case.
long arm of S³ is linked to a horizontal arm on a rocking spindle T which passes
down through a stuffing box into the interior of the slide valve. Arms on the two
rocking spindles T are connected by a link T so that as the one spindle T is
caused to turn partly round, as determined by the governor, the other spindle T
receives the same movement. The lower end of the spindle T is square or poly-

page_text: gonal in section fitting into a corresponding hole in a nut T³, in which the spindle
can slide, but which must turn with the spindle. The nut Te fits on a quick
threaded screw stud, and it is raised or lowered according as the spindle T is
turned by the governor action in the one direction or the other, being raised when
the speed is too great and lowered when it is too little. Within the main slide
valve E is fitted a cut off slide valve T having a central boss which as it descends
with the main slide valve meets the nut T and is raised relatively to the main
slide valve when the nut T2 is raised, thus the sooner covering the ports of the main
slide valve and cutting off the steam supply.
In the engine shewn in Figures 3 and 4 there is a high pressure cylinder A
and a low pressure cylinder A¹ both double acting and both having their piston
rods connected to opposite cranks in the manner described above. In this case
there is a single eccentric disc formed on the shaft between the two cranks and
connected by a rod F¹ to a crosshead F from which a pair of rods F2 extend
through stuffing boxes to each of the lower slide valves H and H¹. Each of these
lower slide valves is connected by another pair of rods F3 passing through bushed
holes of the piston to the upper slide valves K and K. Boiler steam is supplied
to a jacket L communicating with ports above the slide valve K and below the
slide valve H. The cavities M and N receiving exhaust from the high pressure
cylinder A by the lateral ports which are governed by the slide valves K and H,
communicate with lateral ports governed by the slide valves K¹ and H¹, for supply
of the low pressure cylinder A', the exhaust from which passes by spaces above K
and below H₁ to the exhaust chamber P.
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. A single acting high speed engine constructed and operating substantially
as described with reference to Figures 1 and 2 of the drawings.
2. A compound double acting high speed engine substantially as described
with reference to Figures 3 and 4 of the drawings.
Dated this 14th day of May 1900
ABEL & IMRAY,
Agents for the Applicant.