IMPROVEMENTS IN THE GEARING FOR ACTUATING THE SLIDE VALVES PUMPS AND OTHER PARTS OF MOTIVE POWER ENGINES
Year: 1882

page_text: PROVISIONAL SPECIFICATION left by Arthur William Cooper at the
Office of the Commissioners of Patents on the 27th April 1882.
ARTHUR WILLIAM COOPER, of Dundee, in the County of Forfar, North Britain,
"IMPROVEMENTS IN THE GEARING FOR ACTUATING THE SLIDE VALVES PUMPS AND
OTHER PARTS OF MOTIVE POWER ENGINES,"
This Invention consists in arrangements of mechanism for reducing the number
of working parts in marine and other motive power engines also to effect a more
compact and accessible placing of the parts thereof.
These advantages are attained by means of an intermediate shaft carried in
journals parallel to the main crank shaft of the engine and rotated by cranks on
the intermediate shaft coupled to cranks on the main shaft by connecting rods.―
A collar is formed on the main shaft crank pins to prevent contact between the
main and intermediate shaft, the cranks on it and on the main shaft are at the
same angle and length, and make an angle with each other on the same shaft less
than 180 degrees-90 degrees being preferred-so that there may be no dead
points. This intermediate shaft being driven is rotated in unison with the main
crank shaft may be placed in a position suitable for the centres of the slide valves,
or valve, when these are turned aside from the centre line of the main crank
shaft. A single eccentric may be fitted to work each valve, or if onu valve is
placed above the other then one eccentric may work both.-These eccentrics are
fitted on the intermediate shaft in such a manner that a proper motion may be
given to the eccentric centre allowing the valves to be adjusted in the usual way,
either full in gear or drawn back to allow of an earlier cut-off as required. The
reversing or adjusting of the gear is performed by hand, steam, or other year as
desired. An expansion valve, or valves, may be driven from the intermediate
shaft as required, with the addition of an eccentric for that purpose, or other
equivalent means as suitable. The main pumps are preferably actuated by return
cranks, or pins overhung from the point of the crank pins on the fore and aft ends
of the intermediate shaft in a marine screw engine. By this means, the strain on
the intermediate shaft journals is kept as low as possible as by any other arrange-
ment the power would be transmitted through the main journals thus increasing
friction, and a consequent loss of power. The circulating water pump and one

page_text: bilge pump at each side are placed at that end of the sole plate preferably furthest
from the boilers, and the air pump, and one feed pump at each side next the boilers.
The height of the intermediate shaft or position thereof being determined by style
of engine.
In some cases it may be found more convenient to drive the intermediate shaft
by a return crank at the forward end of both the main and intermediate shafts, or
by one connection to one main crank pin, and one to single crank at the forward
end of the shaft, these being connected to companion cranks on the intermediate
shaft, although the first mentioned arrangement is preferable when suitable.