Improvements in and relating to the Driving Mechanism of Locomotive and other Steam Engines.
Year: 1897

page_text: Cate of Application, 1st May, 1897-Accepted, 26th June, 1897
COMPLETE SPECIFICATION.
Improvements in and relating to the Driving Mechanism of
Locomotive and other Steam Engines.
I, AIMÉ ROBERT of Gilly in the Kingdom of Belgium, 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 :-
This invention relates principally to the construction of steam cylinders having
two independent pistons travelling in opposite directions.
The invention also consists in the combination of steam cylinders having two
pistons with the mechanical parts; a combination which permits of the two
sets of driving wheels of a locomotive being actuated directly by means of
connecting rods.
A simple distributing apparatus such as is commonly employed in cylinders of
the ordinary type suffices for the distribution of the steam to the two pistons acting
in opposite directions, and this is effected by means of a pipe connecting the
two extremities of the cylinder, whereby they are placed in communication one
with another.
This construction of the cylinder and its combination with the power transmitting
parts allows of a diminution of the diameter of the cylinders and also of the travel
of the pistons, and this to a considerable extent, seeing that the steam acts upon
four pistons in two cylinders instead of upon two pistons with which engines are
ordinarily provided. In addition to this, this novel arrangement replaces the four
cylinders in locomotives intended for use upon steep gradients and upon those
required to attain high speeds. That is to say, this novel arrangement in the
construction gives the advantages of an engine having four cylinders for over-
coming the force of inertia, whilst it offers the same degree of stability as is
afforded by the use of four cylinders.
The advantages of my improved method in all these respects are clearly shewn
in the accompanying drawing, in which my invention is shewn applied to a locomotive
for drawing express trains.
Figure 1 is a side elevation of a locomotive constructed in accordance with this
invention the cylinder being shown in section.
Figure 2 is a longitudinal section of the same.
Figure 3 is a horizontal section, and
Figure 4 a diagrammatic view.
A is the cylinder, B B the pistons, C the distributing or slide valve, c the port
for the admission of steam at the middle of the cylinder, at a point exactly midway
between the two pistons, el is the port for admitting the steam at the rear end of
the cylinder and D (Fig. 3) is the steam passage connecting the two extremities of
the cylinder.
The two pistons are alternately acted upon by the steam upon their front and
rear faces, owing to the ordinary motion of the slide valve. The motion of the
front piston is transmitted by means of the jointed rod E to a crank F arranged
n the front portion of the frame of the engine and with which is connected the
connecting rod H the other extremity of this latter being connected with the
rank 1 of the wheel J. The rear piston transmits motion direct to the wheel K

page_text: by means of the connecting rod M; in this manner the two sets of driving wheels K
and J receive the same effort of impulsion.
A locomotive constructed so as to fulfil these conditions, and in which everything
is balanced, will run smoothly and start without shocks or slipping.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is :-
1. A steam cylinder for two pistons, such pistons acting in opposite directions in
the said cylinder which is combined with a steam distributing valve acting in the
-ordinary manner, but in which the passages for the admission of steam are arranged
in such a manner that the steam acts upon the front and rear faces of the pistons,
owing to the fact that a steam admission port is provided exactly in the middle of
the cylinder between the two pistons by which their adjacent faces are acted upon,
and that another steam admission port communicates with a passage connecting
the two internal extremities of the cylinder so that the outer faces of the pistons
may be acted upon, as above described and shewn in the accompanying drawing.
2. In a locomotive engine, the employment and the combination of cylinders
having two pistons, the two pistons acting in opposite directions and simul-
taneously upon the two sets of driving wheels, owing to the fact that the pistons
are connected with these latter by means of connecting rods, as above described and
illustrated in the accompanying drawing.
3. In motor or propulsion engines, the employment and the combination of
cylinders having two pistons with their special transmission arrangement as above
described and illustrated in the accompanying drawing.
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.