Improvements in Steam Engine Governors.
Year: 1887

page_text: Date of Application, 11th Jan., 1887.
Specification Accepted, 11th Feb., 1887.
COMPLETE SPECIFICATION.
Improvements in Steam Engine Governors.
1, FRANCIS MARION RITES, of No. 2504 Penn Avenue, Pittsburgh, in the County
of Allegheny, State of Pennsylvania, and United States of America, Mechanical
Engineer, do hereby declare the nature of my said invention and in what manner the
same is to be performed, to be particularly described and ascertained in and by the
following statement:-
My invention relates to automatic cut off governors of the class which are mounted
upon the main or crank shaft of the engine and effect regulation by variation of the
position of an adjustable eccentric actuating a valve which governs the supply of
steam to the cylinder, and its object is to provide a governor specially adapted
to engines having their distribution valves reciprocating in substantially vertical
planes in the employment of which, under a simplified and economical construction,
the gravity of the eccentric and of the reciprocating parts shall be effectively
counterbalanced and the weight of the eccentric reduced to the minimum compatible
with required strength. To this end, my invention, generally stated, consists in the
combination of an adjustable eccentric or crank pin pivoted upon a crank shaft and
coupled to a valve reciprocating in a substantially vertical plane, and a governor weight
pivoted upon the crank shaft and coupled to the eccentric in such manner as to
move in opposite direction thereto. The improvements claimed are hereinafter fully
set forth.
In previous constructions of the class to which my invention relates, the gravity
of the reciprocating parts has been balanced by provision for the exertion of an
upwardly acting force, and it has ordinarily been necessary to employ two governor
weights coupled together and pivoted at opposite points to a supporting member on
the shaft, so as to balance each other as well as to counterbalance the eccentric by
a corresponding weight. I am further aware that governors having but a single
weight, the gravity of which is counterbalanced by that of the eccentric, have been
heretofore known and used, but such require a comparatively heavy eccentric and
are incapable of effective operation with a vertically reciprocating valve without
the provision of a special balancing device for gravity of the reciprocating parts

page_text: Under my invention such balance is effected by the gravity of the single weight
and the eccentric being freed from balancing function may be made as light as its
strength will permit, or a single crank pin may be employed in its stead.
In the accompanying drawings: Figure 1, is a vertical transverse section through
a steam engine taken at the centre of the valve chest, showing a face view of a
governor embodying my invention; Fig. 2, a side view in elevation of the governor
Fig. 8, a face view of the crank arm illustrating more fully the positions of the
pivots of the eccentric and weight, and; Fig. 4, a similar view of the same with the
weight and spring attached.
The engine in which my invention is herein shown as applied is of the vertical
single acting type, having its cylinders 1, secured upon the top of a crank case or
box 3, provided with proper end bearings for a crank shaft 5, having double
cranks 2, to the pins 4, of which the pistons of the cylinders 1, are coupled by
connecting rods. The admission and exhaust of steam to and from the cylinders I,
is effected by a distribution valve 7, composed of an upper piston 8, and a lower
piston 9, fixed upon a valve stem 10, which is adapted to reciprocate in a sleeve or
bushing 11, provided with proper steam and exhaust ports and fixed in a valve
chest 12, located between the cylinders 1, and slightly inclined relatively thereto, such
construction being one of the numerous types of vertical engines to which my
improvements are desirably applicable.
In the practice of my invention, the distribution valve 7, is reciprocated by an
eccentric 13, the strap 19, of which is secured to one end of an eccentric rod 20,
whose opposite end is coupled, by a pin 21, to the valve 7, the throw of said
eccentric being varied as required in the operation of the engine by adjustment of its
position relatively to the crank line, in order to vary the travel of the valve and
consequently the degree of expansion or point of cut off, as presently to be described.
A crank pin coupled to the lower end of the eccentric rod would perform, as an
equivalent, the function of the eccentric.
The eccentric 13, is made as light as may suffice to afford sufficient strength,
being; as shown, a simple ring, formed in halves or sections bolted together for
convenience of application, and having an arm or lug 15, on one of its sections,
which is pivoted by a pin 16, to the arm of one of the cranks 2, of the crank shaft 5.
It will be seen that by movement of the eccentric in one or the other direction
about the axis of its pivot 16, its throw, and consequently the degree of traverse
which it imparts to the valve 7, is increased or diminished, as the case may be,
such movement being imparted to the eccentric by the tension of a spring 14, or the
centrifugal force of a governor weight 26, as either may preponderate under varying
conditions of pressure or resistance, or both.
A single governor weight 26, is provided by a pin 17, to an extension of the
crank arm 6, and is coupled by a link 18, to the lug 15, which receives the pivot 16,
of the eccentric, the relation of the pivots 16 and 17, of the eccentric and weight to
the link 18, being such that the eccentric and weight are compelled to move in
opposite directions, and the gravity of the reciprocating parts, to wit, the eccentric
rod and valve, which are connected to the eccentric is exerted in opposition to that
of the governor weight, that is to say downward or outward movement of the weight
induces corresponding upward movement of the eccentric and reciprocating parts
and vice versa. In the construction shown the eccentric and governor weight are
pivoted to the crank arm on opposite sides of the shaft but such location is not an
essential one, as both might be pivoted on the same side and by suitable connections
to an intermediate sleeve, the balancing action of the governor weight and the
reciprocating parts could be equivalently provided for.
The outward movement of the weight 26, upon its pivot 17, under the influence of
centrifugal force by which the throw of the eccentric is reduced is opposed by the
iension of a helical spring 14, by which the throw of the eccentric and travel of
the valve are increased in accordance with increase of load or diminution of
pressure or both, as from time to time required. The spring 14, bears at one end

page_text: against an abutment 22, on the crank arm, and at the other against a stop 23, on a
pin 24, which passes freely through an opening in the crank arm and is coupled to
the weight 26. The tension of the spring 14, may be varied by the adjustment of a
nut 25, engaging a screw thread on the pin 24, and forming an abutment for the
stop 23.
My invention, in addition to simplifying and reducing the cost of an automatic cut
off mechanism possesses the further advantage of presenting the same in such form
as to be readily adaptable to operation within the contracted compass of a closed
crank case.
The substantial reduction of weight of the eccentric and the permissible
substitution of a light, crank pin renders a counterbalance unnecessary, and the
gravity of the reciprocating parts is fully balanced in all positions of the valve by
hat of the governor weight.
Having now, particularly described and ascertained the nature of my said invention,
and in what manner the same is to be performed, I declare that what I claim is:
1. The combination of an eccentric or crank pin pivoted upon a crank shaft, a
distribution valve adapted to reciprocate in a substantially vertical plane and coupled
to said eccentric, and a governor weight pivoted upon the crank shaft, and coupled
to the eccentric so as to move in opposite direction thereto, substantially as set
forth.
2. The combination of a crank arm, an eccentric pivoted thereto on one side of
the axis of the crank shaft, a governor weight pivoted thereto on the opposite side
of the axis of the crank shaft, a link connecting the governor weight and eccentric
on the side of the crank shaft furthest from the free end of the weight, and a spring
bearing against the crank arm and the governor weight, substantially as set forth.
3. The combination of a crank armi, an eccentric and a governor weight each
pivoted thereto, and coupled by an intermediate connection so as to move in opposite
directions upon their pivots, a pin coupled to the governor weight and passing freely
through the crank arm, and a spring bearing against an abutment on the crank arin
and against a stop on said pin, substantially as set forth.