Improvements in Expansion Gear for Steam and other Engines.
Year: 1889

page_text: Date of Application, 21st Oct., 1889
Complete Specification Left, 21st July, 1890-Accented 6th Sent
1800
PROVISIONAL SPECIFICATION.
Improvements in Expansion Gear for Steam and other Engines.
HORACE MUNCASTER St. Georges near Wellington Salop Mechanical Engineer do
hereby declare the nature of this invention to be as follows:-
This invention relates to cut off or variable expansion mechanism for engines
operated by steam or other expansive fluid and its object is chiefly to provide
improved automatic mechanisin controlled by an ordinary centrifugal governor and
which is applicable to existing engines provided with common slide or other forms
of distribution valves worked by means of an eccentric and rod.
The invention may be described as follows.
To the eccentric rod of engine is fixed a pin or stud, on which works a lever the
other end of which is connected to a rod extending to and working the cut off valve
either directly or through the medium of an L lever according to the position of the
cut off valve.
The said lever is pivotted near the middle to one end of a link the other end of
which is connected to a lever in communication with the governor and is guided in a
curved path and made to assume a position varying with the rise of the governor and
thereby varying the angle of the link and the amplitude of the oscillations of the first
mentioned lever and so altering & modifying the travel of the cut off valve.
Dated this 12th day of October 1889.
H. MUNCASTER.
COMPLETE SPECIFICATION.
Improvements in Expansion Gear for Steam and other Engines.
HORACE MUNCASTER St. Georges Wellington Salop Mechanical 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 to cut-off or variable expansion mechanism for engines operated
by steam or other expansive fluid and its object is chiefly to provide improved automatic
mechanism controlled by an ordinary centrifugal governor and which is applicable to
engines provided with slide valves or other forms of distribution valves worked by
means of an excentric and rod.
The invention may be described by the aid of the accompanying drawings.
Fig. 1 is an elevation of mechanism arranged according to this invention.
Fig. 2 is a plan of same in part section.
a is a pin or stud fixed to extension of the excentric rod on this stud works the
lever or bell-crank b which is pivotted to a link d, the other end of which is connected
to the lever e of which the trunnion f forming part of the lever e works in a sleeve g,
which is firmly fixed in a suitable position to guide the point in a curved path when
acted upon by the rising or falling of the governors by means of the rod k.
The point h is made to assume a position varying with the lift of the governors
thereby varying the angle of the link d and the amplitude of the oscillations of the
first mentioned lever and also the travel of the cut off valve m.
It is evident that an ordinary flat cut off valve may be used in place of the circular
valve shewn.
It is intended to use a modification of this gear to actuate a valve similar to that
hewn in conjunction with my Patent No. 2301, 1888.

page_text: 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) The novel arrangement of expansion gear or cut off mechanism characterized
by the employment of the main excentric rod x to actuate a system of links modified
by the variations of the governors.
(2) The employment for this purpose of a stud or pin a fixed to the excentric rod,
on which works a lever the other end of which is connected to a rod extending and
working the cut-off valve either directly or through the medium of an L lever according
to position of cut-off valve, the above mentioned lever is pivotted to one end of a link the
other end of which is attached to a lever in communication with the governors and so
guided in a curved path and made to assume a position varying with the lift of the
governors and thereby varying the angle of the link d and the amplitude of the
oscillations of the first mentioned lever and also the travel of the cut-off valve.
Dated this 17th day of July 1890.
H. MUNCASTER.