IMPROVED MECHANISM FOR CONVERTING RECTILINEAR INTO ROTARY MOTION, ESPECIALLY APPLICABLE TO STEAM ENGINES
Year: 1885

page_text: COMPLETE SPECIFICATION.
"
I, ALEXANDER MELVILLE CLARK, of the firm of A. M. and Wm. Clark, of
53, Chancery Lane, in the County of Middlesex, Fellow of the Institute of Patent
Agents, do hereby declare the nature of the said Invention for "IMPROVED
MECHANISM FOR CONVERTING RECTILINEAR INTO ROTARY MOTION, ESPECIALLY
APPLICABLE TO STEAM ENGINES (a communication to me from abroad by Jethro
E. Pencille of Titusville in the County of Crawford (Millwright and Machinist) and
Solomon Christy Rhodes of Bradford in the County of McKean (Oil Producer)
both in the State of Pennsylvania, United States of America) and in what manner
the same is to be performed, to be particularly described and ascertained in and by
the following statement:-
This improved mechanism is specially applicable to steam engines and consists
in a lever mechanism combined with a piston and crank shaft for operation as
hereinafter described and claimed.
Reference is to be had to the accompanying drawings forming part of this
specification, which represent a side elevation of the mechanism as applied to an
engine.
A is an engine cylinder and B is a crank shaft. In suitable bearings a, between
the cylinder and shaft is fitted a rock shaft b, at a greater or less height above the
level of the engine according to the length of the levers used. On this shaft b, in a
vertical plane, the lever d, is fulcrumed, and the lower end of the lever d, is jointed
to the connecting rod e. To the crank of the shaft B is connected a lever g that
extends upward and is connected to lever d by a jointed link i, at its upper end.
Near the lower end of the lever g is connected a link or rod that also connects to
lever d..
4
In operation the right line movement of the piston and crosshead is communicated
through the connecting rod e link (, and lever g, to the crank. The end of the
lever d, connected to rod e, has a movement equal to the length of movement of
ID071

page_text: the piston, and this movement is multiplied by the lever d upon the crank so that
the crank has a longer movement, or a movement greater than would be obtained
by a direct connection with the connecting rod e.
The link by its connection to the levers d, g, assists and regulates the movement.
By means of this mechanism the short piston movement is made to operate a crank
of much greater length, so that there is an increase of leverage and power, as also
dead centres are avoided and friction very much reduced. While these devices are
specially applicable to a steam engine, they may be applied generally for converting
rectilinear into rotary motion.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed I declare that what
I claim is
g
1. The mechanism for converting motion, consisting of the levers d connected
by the links i, and combined with a pitman and crank shaft, substantially in the
manner shown and described.
2. In a mechanism for converting motion the combination of the rock shaft b,
the lever d, connecting rod e lever g, being connected by the link l, to the lever d
substantially as described.
3. The combination of the two levers d, g connected respectively to a connecting
rod and a crank shaft and connected with the link i substantially as described.
4. The combination with a reciprocating. driver and a crank of levers and
connecting links substantially as described whereby the length of the crank is not
limited by the stroke of the driver, and dead centres are avoided as specified.
1607