Improvements in Engines Actuated by Expansible Fluids.
Year: 1896

page_text: Date of Application, 17th June, 1896-Accepted, 18th July, 1896
COMPLETE SPECIFICATION.
Improvements in Engines Actuated by Expansible Fluids.
We, OTTO ABRAHAM and HERMAN MEISEL both of Platkow near Gusow in
the German Empire, Engineers, 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 to improvements in the construction of engines operated
by expansible fluids and its principal object is to provide for more effective
'utilisation of the fluid during expansion.
We will describe our improvements with reference to the accompanying drawings
in which Figure 1 represents a partial sectional elevation, and Figure 2 a partial
plan.
a is the engine cylinder, 6 the piston, and c c¹ two auxiliary pistons respectively
arranged near the ends of the cylinder. The auxiliary pistons are mounted upon
the inner ends of hollow rods dd, which are capable of reciprocation in the bearings
shewn in section at the centres of the bridge pieces . Instead of the ordinary
cylinder covers, the cylinder ends are partly closed by the internal flanges s s¹,
provided with central openings sufficiently large for the springs ff coiled upon
the hollow rods, and each of which abuts at one end upon the auxiliary piston and
at the other end upon the bridge bearing. On each of the hollow rods there is a
collar g g which by coming into contact with the bridge bearing limits the
movement of each auxiliary piston inwards. Normally the inner face of each
auxiliary piston is about flush with the outer edge of the steam port, which is not
indicated in the drawing, and it is retained in this position by the spring for fl
when not acted on by the expansible fluid.
The motion of the piston & may be communicated to a crank by a piston rod and
connecting rod in the usual manner but we prefer to employ the arrangement indicated
by the figures. Here, the piston is fixed upon the centre of the piston rod e which
passes through the auxiliary pistons and their hollow rods d d¹ to the cross heads k k
to which it is connected. To these cross heads there are also connected the two ends
of a chain or its equivalent 7 which passes over and gears with the two chain wheels
or pulleys each of which has arranged upon one of its faces a number of
pawls n n engaging with a ratchet wheel oo'. The two ratchet wheels and sets
of pawls are respectively arranged as shewn by Figure 1 so that when the chain
moves in one direction one of the ratchet wheels is rotated and when in the other
direction the other ratchet wheel is turned. The ratchet wheels are keyed upon
shafts m m' upon which also the two pulleys ppl are keyed, these pulleys being
geared together by the crossed driving belt r.
When expansible fluid under pressure is admitted to the engine, the piston b
commences to move, and at the same time, its pressure acting upon the auxiliary
piston, overcomes the tension of the spring for f and that piston is moved in the
opposite direction to that taken by the piston b. The outward excursion of the
auxiliary piston is limited by the internal flange s or s'. During the expansion of
the fluid, the auxiliary piston is returned by its spring and thus tends to
supplement the force acting upon 6 by the release of the power stored up in the
The resultant
spring upon its compression by the full pressure of the fluid.
movement of the piston b is very uniform and enables smaller and lighter fly
wheels to be used, thus reducing the amount of power wasted in maintaining their
rotation.

page_text: The distribution of steam in the engine can be regulated in any known manner,
but the fluid which is just entering should commence to act before the piston 6 has
come into actual contact with the auxiliary piston c or c². With the arrangement
illustrated for transmitting and converting the motion of the piston b, it is best to
arrange for comparatively slow driving.
The piston 6 touches the auxiliary pistons only when the engine is stopped, and in
this case, the springs ffl prevent any risk of damage.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In an engine operated by expansible fluid, the arrangement and combination
with a piston b, of two anxiliary pistons e c¹ mounted upon the inner ends of hollow
rods through which the piston rod passes and upon which spiral or equivalent
springs are arranged, constructed and operating substantially as and for the
purpose hereinbefore described and as illustrated by the accompanying drawing
Figure 1.
2. In an engine operated by expansible fluid, mechanism and devices for
transmitting and converting the reciprocal motion of the piston and rode into
rotary motion and consisting essentially of the chain l, the two chain wheels or
pulleys i, pawls nn', ratchet wheels oo on the shafts m m', and the pulleys p p¹
geared together by a crossed belt r, constructed. arranged and operating
substantially as hereinbefore described and as illustrated by the accompanying
drawings.
Dated this 16th day of June A.D. 1896.
W. E. HEYS & SON,
Agents for the Applicants.