IMPROVEMENTS IN THE MEANS AND APPARATUS FOR OBTAINING AND APPLYING MOTIVE POWER
Year: 1864

page_text: PROVISIONAL SPECIFICATION left by Charles William Siemens at the
Office of the Commissioners of Patents, with his Petition, on the 81st
December 1864.-Partly a communication from abroad by Werner
Siemens, residing at Berlin, in the Kingdom of Prussia.
I, CHARLES WILLIAM SIEMENS, of No. 3, Great George Street, West-
minster, in the County of Middlesex, do hereby declare the nature of the
said Invention for "IMPROVEMENTS IN THE MEANS AND APPARATUS FOR OBTAINING
AND APPLYING MOTIVE POWER," to be as follows:-
The power of a steam engine is due to the augmentation of volume which
water undergoes in being changed into steam by the application of heat.
Motive power engines have also been constructed in which the expansion of
air or vapours by heat is made a source of power, the air or vapours being in
some cases heated and cooled alternately by means of regenerators; or a
mixture of atmospheric air and combustible gas has been ignited within a
confined space, in order to exert an increased pressure upon a moving piston
in consequence of a great accession of heat due to their combustion. In all
these cases the power is obtained through the pressure of a gaseous or elastic
fluid upon a moving piston or its equivalent.
In another class of engines a non-elastic fluid, namely, water, is employed
to urge the piston or its substitute forward, but in these engines heat is not
employed as cause of motion, but the force of the liquid column is due to
gravitation.

page_text: Now, in the present Invention the characteristics of the two classes of
motive power engines just named are combined. The Invention is based
upon the physical property of some liquids, such as paraffin, to expand very
considerably on being heated. For this purpose a closed receptacle, capable
of resisting considerable internal pressure, is filled with such liquid. One
extremity of this receptacle, which may conveniently be of cylindrical form,
is exposed to a source of heat, whereas the other extremity is cooled by
external application of cold water, or by changing at suitable moments a
portion of the liquid contained in the receptacle or otherwise. A plunger or
piston is provided, which, in being moved to and fro within the cylindrical
vessel transfers the liquid (or a considerable portion of the same) alternately
from the heated portion of the vessel to the cooled portion, and vice versa. A
regenerator, or cavity filled with divided surfaces of metal or other refractory
materials is interposed, through which the liquid passes to and fro, and which
serves to retain the greater portion of the heat contained in the liquid when
this is forced from the beated to the cooled portion of the vessel, and to
restore the same to the liquid on its return. Such regenerators have already
been described by me in reference to steam engines in certain Letters
Patent granted to me, and bearing date the 22nd December 1847, No. 12,006.
The alternate expansion and contraction of the liquid is made available for
obtaining motive power in urging a piston or plunger forward in a cylinder or
vessel, while the liquid is being increased in volume, and allowing it to recede
while the corresponding contraction ensues. The working power may be
obtained by increasing the diameter of the rod carrying the displacing piston
before referred to, and allowing it to work out and in through a stuffing box
or cupped leather at the cooled extremity of the cylindrical chamber. The
enlarged piston rod or plunger imparts the power it receives to a working
.crank or its substitute. This power is considerable, owing to the fact that
liquids possess very little elasticity, but expand with a force which is only
limited by the resisting power of the vessel containing them. Upon the com-
pletion of every outward stroke of the plunger the pressure within the vessel
has to be released in order that the return stroke may be effected without
resistance, or even with the atmospheric pressure in aid of it. This may be
conveniently effected by means of a comparatively small charging cylinder, the
piston of which is worked to and fro by a crank standing at right angles or
nearly so to the crank to which the working plunger is attached, if upon the
same shaft. One extremity of this charging cylinder is in permanent com-
munication with the vessel, and as the piston of the charging cylinder is made
to recede when the effective stroke of the working plunger is almost com-

page_text: pleted, some liquid is withdrawn from the same, and a vacuum created, which
continues to exsist during the return stroke of the working plunger.
Or arrangements of engines similar to those described in certain Letters
Patent granted to me, and bearing date respectively the 20th March 1849
(No. 12,531), and the 28 August 1860 (No. 2074), may be adopted. The
liquid employed in working these engines being almost non-elastic a certain
amount of elasticity may be advantageously provided by introducing into the
cylinder cover or other part a corrugated steel plate yielding to a certain
extent to the internal pressure, or by other means producing the same
result.
Engines may be constructed by the combination of several working plungers
or pistons, as before described, or one displacing plunger and regenerator, as
before described, may be employed for effecting the motion to and fro of a
hydraulic ram or piston, or of several rams or pistons acting in concert and in
accordance with the arbitrary motion imparted to the displacing plunger,
the connection between the plunger and working rams being effected by
means of pipes.