IMPROVEMENTS IN GOVERNORS FOR STEAM AND OTHER ENGINES
Year: 1868

page_text: PROVISIONAL SPECIFICATION left by Daniel La Forest Chase at the
Office of the Commissioner's of Patents, with his Petition, on the
12th June 1868.
I, DANIEL LA FOREST CHASE, of Boston, Massachusetts, United
States of America, now of No. 18, Worship Street, in the County of
Middlesex, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN GOVERNORS FOR STEAM AND OTHER ENGINES," to be as
follows:-
The nature of my said Invention consists chiefly in the novel con-
struction and arrangement of the parts of an engine governor, whereby
the work of opening and closing the throttle valve is entirely effected by
the engine, which at the same time is completely under the control of
the
governor. The latter being relieved from the resistance offered by
the friction and weight of the valve and spindle is rendered more
sensitive to slight variations in the speed of the engine whose motion is
thereby rendered more regular and uniform than has hitherto been
practicable. A shaft which drives the vertical spindle of the governor
rotates a pinion between two racks (preferably curved) carried by a
segment fixed on the throttle valve spindle. The said racks are arranged

page_text: excentrically or obliquely to the said spindle and a space is left without
teeth at one end of each rack. The pinion is connected with the
pendulum balls, and as the same rise or fall is thrown into gear with
one or other of the racks or kept midway between the two, thereby
opening or closing the valve, or keeping the same partially open. The
governor balls with their arms and spindle may be of any approved
form and construction and may be rotated by means of bevel wheels,
pulleys, or other suitable driving mechanism connected with the engine
to be regulated. I prefer to fix a pulley on a horizontal shaft extended
through bearings in the standard which supports the vertical spindle.
A small toothed wheel is fixed on the other end of this horizontal shaft,
which wheel gears into another wheel fixed on a short spindle, whose
other end carries the pinion which gears with the racks. The said
spindle is preferably supported in a forked bracket which is pivotted to
the standard in such a manner as to allow the pinion on its outer end
to move freely into gear with either of the two racks while the pinion is
kept rotating in the same direction by means of its connection with the
horizontal shaft. The required movements of the pinion to cause it to
engage with the upper or lower rack are preferably effected by means of
a lever and suspension link, the said lever being connected at one end in
the ordinary manner with a sliding collar, or other device on the governor
spindle, and at its other end to the link which is attached to the forked
bracket. The latter is by this means caused to follow the movements
of the balls as they risc or fall under the influence of variations in the
speed of the engine, and the pinion is thus thrown into gear with either
of the racks, or kept disengaged from the same. The pinion is so formed
and arranged that it will turn freely without engaging with either rack
when the speed of the engine is uniform, but should it be increased or
retarded the said pinion rising or falling with the bracket will
immediately engage one of the racks and so move the segment and
spindle in the direction for either opening or closing the valve. The
space without teeth is formed at opposite extremities of the two racks.
These spaces-allow the pinion to revolve freely at these points, the valve
being then either fully open or closed. As the balls rise or fall the
pinion will leave the space and engaging with the teeth of the opposite
rack will move the segment and properly adjust the valve. The
excentricity of the racks with regard to the valve spindle allows a
reasonable amount of play to the governor balls, and also prevents any
unnecessary motion of the racks and segment when engaged by the

page_text: pinion, their motion being limited to the extent required by the variation
of speed. The segment is extended beyond the spindle of the valve
and furnished with a weight to counterbalance the weight of the racks.
the teeth of the latter are preferably made like those of an ordinary
ratchet. If preferred the two racks may be formed on the upper and
lower edges of a curved or straight piece of metal, a separate pinion
being used for each rack, and instead of using an ordinary throttle valve
as above described and attaching the racks excentrically to the spindle
or axis of the said valve a lifting valve may be used with the racks
arranged obliquely upon the rod or stem of such valve.