IMPROVEMENTS IN GOVERNORS FOR STEAM AND OTHER ENGINES
Year: 1879

page_text: PROVISIONAL SPECIFICATION left by George Frederick Redfern at the Office
of the Commissioners of Patents on the 9th April 1879. A communication
from abroad by Edgar Side, of Brooklyn, New York, in the United States of
America.
GEORGE FREDERICK REDFERN, of the General Patent Office, 4, South Street,
Finsbury, in the County of Middlesex, Patent Agent. "IMPROVEMENTS IN
GOVERNORS FOR STEAM AND OTHER ENGINES." [A communication from abroad by
Edgar Side, of Brooklyn, New York, in the United States of America]
The Invention communicated to me relates to improvements in governors for
steam and other engines.
In carrying out these improvements as applied to a governor suitable for marine
engines a wheel is employed cast with recesses in the inner part of the rim to receive
one or more sets of springs radially, and fastened in by wedges driven in by bolts.
A disc with recesses in the face receives the other ends of the springs. The face of
this disc, which is keyed to the shaft, acts as a bearing for the lugs, which are cast
on the inner part of the wheel. One of these lugs is enlarged to receive the after
wrist pin of the engine. The lugs are slotted to receive bars which slide in a
direction parallel to the shaft. These bars have a stud near the front end for rollers
to run on, such rollers engaging in a cam-groove cut in the face of the disc. The
other ends of these bars are fixed to lugs projecting from a sleeve which fits free
on the hub of the wheel. The sleeve has a groove for the forked end of a lever to
engage in. The shaft is bored up the centre to receive a small shaft, and a slot is
cut in the shaft through to the bore under the hub of the wheel, a square piece
being fitted in this slot. A bolt runs through it and screws into the small shaft.
The bolt projects above the piece to receive a roller which ongages in a cam-groove.
A slot is also cut right through the shaft, in which slot is fitted a square piece on
each side of the small shaft. A split sleeve is provided with lugs on one side to
bolt it together, and two lugs on the other side which cover the pieces in the slot,
a bolt passing through the whole. For an engine that is geared the wheel may have
teeth on the rim, and take the place of a pinion.
The action of this mechanism is as follows:-
The pressure of the piston on the crank wheel or pinion, which is free on the
shaft, transmits the pressure through the springs to the disc, which is keyed on
the shaft. The springs deflect according to the resistance or load, and the crank
wheel or pinion will have a relative position on the shaft according to the deflection
of the springs, and the cam grooves through the rollers and bars will slide the sleeve
along the shaft, and this motion is transmitted to the throttle or other valve, and
thereby admits sufficient steam to drive the engine at a given speed. There are
three different positions for the groove sleeve, and the mechanism is varied to suit
each position. If used as a pinion the engine connections may permit a grooved
roller to project from the end of the small shaft, and in this case the shaft will be
bored only to the first hereinbefore described slot,

page_text: For land engines a belt wheel is provided, free on the shaft, and fitted inside
with curved springs, one end of which bears against a rib which turns at right
angles and extends to the rim of the wheel. At the angle of this rib is a bolt, the
point of which bears against the end of the spring. At a distance from the end of
the spring and opposite to the bolt another rib to support the spring in position
against the pressure of the bolt. A hub with arms extends nearly to the rim of
the wheel, and is fast on the shaft. A cam shaped surface receives the pressure
of the springs at varying distances from the centre of the shaft. The outer ends of
the arms are met by leather or other buffers. The hub of the wheel may be
extended by a sleeve, on the end of which is fitted a flange having a groove cut
across near the bore with a piece fitted to slide in it. The eccentric slides on a
square nut bored to fit the shaft. The flange, which is fast to the shaft, has a
radial slide piece; these two slide pieces and the eccentric are bored with holes
made to coincide, and a pin is fitted through them. With this arrangement the
relative movement of the belt-wheel to the shaft determines the throw of the
eccentric, and hence the stroke of the valve, thereby admitting sufficient steam to
drive the engine at a given speed. To work a variable cut-off valve eccentrics are
substituted for the herein before described flanges, one fixed on the sleeve for the
cut off valve, and the other fixed on the shaft for the ordinary valve.
A stud projecting from the arm extends through a segmental concentric slot, on
the margin of which is marked an index, and a pointer is fitted to slide in this
slot.
This arrangement answers the purpose of a dynamometer, as the pointer will
register the pressure of the load at that point of the radii of the wheel, and this
pressure multiplied by the velocity in feet per minute, divided by thirty three
thousand, gives the power used. It will be seen that this mechanism so far only
governs the engine in relation to its load, and that the engine will increase in
speed as the boiler pressure increases, and to obviate this one of the three following
devices must be used in combination with the hereinbefore described arrangement,
videlicet: A small piston acted upon by the boiler pressure, and resisted by
springs, which may be adjusted by hand-nuts; or the piston rod runs through a
hollow valve stem, and connects with the valve by means of a link. The piston
acting on the valve causes it to partially revolve in the ring on the end of the valve
stem; this partial revolution of the valve on the ports increases the lap of the
valve in relation to the ports, and thereby admits less steam to the cylinder. The
eccentric rod is connected to the arm which projects from the small cylinder. For
a throttle or slide valve crank the crank and stem have a steam way into the steam
chamber. On the end of the crank is the piston. The cylinder is attached to a
sleeve which has a stud on opposite sides of it; the fork of the eccentric or throttle
valve rod engages with these crank studs. As the steam increases the cylinder and
crank are carried from the centre of the stem, thereby decreasing the throw of the
valve, and admitting less steam to the cylinder. The small cylinder may be attached
or cast to the bed of the engine; a cap with a square hole for a key is screwed in
at the bottom; the piston and cross-head are cast in one; the cross-head, which is
split and bolted through to take up wear, slides on guides. In 'the centre of the
cross-head, which has a hub on each side, is pivotted a lever. The eccentric rod
fork engages this lever, and the lever slides through a swivel joint on the valve
stem.
The increasing pressure of steam forces the piston up, and along with it the fork
and lever, thereby shortening the stroke of the valve, and admitting less steam to
the cylinder. These pistons are in two parts, screwed together, and have an
annular space for rubber or other packing.