IMPROVEMENTS IN THE CYLINDERS AND PISTONS OF STEAM AND OTHER ENGINES OR MACHINES PROPELLED BY AERIFORM FLUIDS
Year: 1860

page_text: PROVISIONAL SPECIFICATION left by Marc Antoine François Mennons:
at the Office of the Commissioners of Patents, with his Petition, on
the 17th May 1860.-A communication from Joseph Auguste Monnier
and Georges Brunier, both resident at Marseilles, Mechanical Engineers.
I, MARC ANTOINE FRANÇOIS MENNONS, of the British and Foreign Patent
Offices, 39, Rue de l'Echiquier, Paris, in the Empire of France, do hereby
declare the nature of the said Invention for "IMPROVEMENTS IN THE CYLINDERS
AND PISTONS OF STEAM AND OTHER ENGINES OR MACHINES PROPELLED BY AERIFORM
FLUIDS," to be as follows:-
The Invention is based on an application of the screw to the working
surfaces of the cylinders and pistons of motive engines or machinery for general
purposes actuated by steam and other aeriform fluids. The accompanying
Drawing represents a practical application of this principle.
Fig. 1 is an ordinary steam cylinder, round the inner surface of which is
cut a spiral groove receiving the metallic screw shewn apart in Figure 2 ;
Fig. 3 represents a piston of helical form, corresponding with the cylinder
screw (Fig. 2), in which it works. The rod of this piston is threaded to the
same pitch, and after having passed through the cylinder cover A and the
stuffing box B is maintained in a perfectly central position by the tapped collar
C, in which it revolves; Fig. 4 represents the complete arrangement com-
posed of the different parts above described, with the addition of an ordinary
valve box. The steam admitted into the cylinder thus constructed exerts its
pressure on one of the free surfaces of the helical piston (say, at X), and

page_text: imparting to the latter a rotatory motion compels it to follow the convolutions
of the main screw. The down stroke completed, the second free surface (invi-
sible in the Drawing) receives in its turn the action of the steam, the piston
revolving in the opposite direction ascends the spiral to its starting point, and
so on alternately as in ordinary engines.
In the above application of the Invention the action of the steam on the
piston may be compared to that of the enflamed powder on the projectiles of
rifled ordnance. The cylinder with its helical core corresponds with the rifled
barrel of the cannon, the helical piston corresponds with the projectile, and
the propelling fluid in exerting its pressure produces in both cases a movement
of rotation, the velocity of which is proportioned to the pitch of the spiral and
the expansive force developed.
Among the advantages to be derived from the present system may be
noted, 1stly, increased range of the motive fluid in a given length of
cylinder; 2dly, increase of positive force resulting from the manner in which
the motive fluid exercises its pressure on the surfaces of the piston combined
with the mechanical action of the screw; 3dly, direct production of circular
motion, which may be readily converted into rectilinear or other. As above
stated, the same principle may be adopted in the construction of all engines or
apparatus for general purposes in which aeriform fluids are used as the motive
agent, the mode of application and minor details being varied as may bo
required. It is needless to add that it may also be applied with the utmost
facility to cylinders and pistons already in use, without necessitating any
essential modifications in the machinery to which they belong.