IMPROVEMENTS IN MOTIVE-POWER ENGINES
Year: 1870

page_text: PROVISIONAL SPECIFICATION left by John Yule at the Office of
the Commissioners of Patents, with his Petition, on the 24th May
1870.
I, JOHN YULE, of Glasgow, in the County of Lanark, North Britain,
Engineer, do hereby declare the nature of the said Invention of
"IMPROVEMENTS IN MOTIVE-POWER ENGINES," to be as follows, that is
to say :-
The first part of this Invention relates to that part of a motive-power
engine known as the governor, and it consists in coupling the rods or
levers (which carry the balls or weights) by links to one or more circular
friction plates concentric with and placed on the vertical shaft of the
governor, and so as to revolve with it. As the governor increases or
diminishes in its rate of revolution the rising and falling action of the
balls produces a corresponding rising and falling of the friction plate or
plates. Relatively with the friction plate or plates there are situated
one or more friction wheels carried upon a shaft or shafts, and driving
a shaft with a screw thread cut thereon (the shaft having the said screw

page_text: thread in the case of using two friction plates and one friction wheel
being the same as that in which the said friction wheel is carried). In
the case of using two friction plates these as they rise and fall act upon
opposite points of the circumference of the friction wheel, and so rotate
it in opposite directions alternately, and as these rotations are also
imparted to the screw herein-before referred to it traverses a nut
connected to a lever or levers also in opposite directions, the said lever
or levers being coupled to the link motion at once regulates the
cut-off and travel of the valve, and therefore the motive agent,
such as steam, air, or gas within the cylinder. In the case of a double
or compound slide valve it is preferred to so connect the governor that
it shall act upon the top slide or cover. In the case of using one
friction plate its upper and under surface acts alternately on two
friction wheels which drive the screw shaft by means of spur or bevil
gearing. The arrangements of governors herein-before set forth may
also by employed to regulate the throttle valve.
In applying the said governors to engines in which there is no link
motion the lever is caused to actuate one or more cams carried on the
driving shaft of the engine by moving the said cam or cams longi-
tudinally theron, and the cams having inclined faces or edges as they
are thus moved act at different times and for different lengths of time
upon the rods driving the steam admission valves (which may be either
ordinary slide valves or piston valves), thus regulating the admission
and cut off of the motive fluid. In place of using friction plates or
friction wheels as herein-before set forth, plates and wheels having teeth
to gear into each other may be employed.
The second part of this Invention relates to an improved arrangement
of mechanism for auxiliating mine pumping engines, or it may be
applied to engines when at first constructed, and it consists, under one
modification, of a steam cylinder and piston placed at an angle, the
piston being connected to the bell crank over the mouth of the shaft,
and to which the pump rods are coupled. The valves for admitting the
steam are driven by means of one or more cams on the revolving
pumping shaft or on the crank shaft, and as the said cams revolve they
push a rod or rods connected to the valves, thereby opening them, the
valves being closed again by means of the pressure of the steam acting
upon a piston attached to them, The valves for admission of the steam

page_text: may be either circular valves or flat valves. The exhaust valve is by
preference placed on the under side of the cylinder, and driven by an
eccentric.
Under a second modification of this part of the Invention the auxiliary
cylinder in place of being connected to the bell cranks may be placed
behind, above, or below the pumping crank, and the piston connected
thereto.
The second part of the Invention may be applied to engines wherein
the pumping crank is placed either on the crank shaft of the engine or
on a second motion pumping shaft.