Improvements in Compound Steam Motors for Driving Vehicles.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Compound Steam Motors for Driving Vehicles.
CHARLES TENNETT, of 180A, Leeds Road, Bradford, in the County of York,
Engineer, and ALFRED JOSEPH RILEY, of 25, Talbot Street, Batley, also in the
County of York, Boiler Maker, do hereby declare the nature of this invention to
be as follows:-
We
This invention relates to the valve gear of compound expansive moters having
pistons of the plunger or trunk type whereby an ordinery piston or D valve is
made to perform the functions of inlet and exhaust for both cylinders by means
of eccentrics and links. We accomplish this as follows, employing two cylinders
for ligh and low pressure making one valve answer the purpose for both cylinders
steam being admited to one end of the pistons only for each revolution.
employ the usual three ported valve steam being admited to the first port and
cylinder and exhausted through the valve to the second port and cylinder from
which it may be exhausted through the third port to a third cylinder or condenser.
At the time it is admiting steam through the first port to the first cylinder it is
exhausting from the second cylinder into the third cylinder or condenser. In
order to do this we make the lap of one end of the valve to cover both the second
and third ports.
Dated this 15th day of September 1897.
CHARLES TENNETT.
ALFRED JOSEPH RILEY.
COMPLETE SPECIFICATION.
Improvements in Compound Steam Motors for Driving Vehicles.
We, CHARLES TENNETT, of 180A, Leeds Road, Bradford, Engineer, and ALFRED
JOSEPH RILEY, of 25, Talbot Street, Batley, Boiler Maker, both in the County of
York, 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:-
:-
Our invention relates to improvements in the valve gear of compound or
expansion motors having pistons of the plunger or trunk type, whereby an
ordinary D-valve or piston-valve is minde to perform the functions of inlet and
exhaust for both high-pressure and low-pressure cylinders.
n.

page_text: Fig. 2 is a sectional elevation of D-valve and ports, showing the position of the
valve when steam is being admitted to the high-pressure cylinder.
Fig. 3 shows position of valve when steam is exhausted from the high-pressure
to the low-pressure cylinder.
Fig. 4 shows position of valve when steam is exhausted from the low-pressure
cylinder.
We employ two cylinders A and B, and admit steam to one side only of the
pistons for each revolution of the crank shaft C, the cylinders being preferably
open at the ends nearest the said crank shaft. The valve D has three ports, and
is operated from the crank shaft C by means of an eccentric and rod or the like.
When the valve is in the position shown in Fig. 2, steam is admitted through
the first port E to the high-pressure cylinder A, the steam in the low-pressure
cylinder B being at the same time exhausted through the ports F and G to the
condenser or (in the case of a triple-expansion motor) third cylinder H. When
the valve D reaches the position shown in Fig. 3, the steam in the high-pressure
cylinder A is exhausted through the ports E and F to the low-pressure cylinder B,
the port G being closed. On the valve reaching the position shown in Fig. 4,
steam is again admitted to the high-pressure cylinder A and exhausted from the
low-pressure cylinder B.
The lap of the valve D at the end K must be sufficient to cover two ports, so
as to prevent the port G opening to the steam-box, and any suitable cut-off may be
given to the cylinders A and B when setting the valve 1).
Having now particularly described and ascertained the nature of our said
invention, and in what manner the same is to be performed, we declare that what
we claim is:
1. In a compound steam motor the employment of a single valve, of any suitable
type, for controlling the inlet to and the exhaust from both the cylinders, substan-
tially as shown and described.
2. In an expansion steam motor, the combination of the valve D, having
ports E, F, and G, (the said valve being operated by any suitable means), with
the cylinders A and B, and the condenser or additional cylinder H, substantially
as, and for the purposes, shown and described.
Dated this 16th day of June 1898
JOHN E. WALSH,
Royal Exchange Chambers, Boar Lane, Leeds,
Patent Agent for the Applicants.