Improvements in Centrifugal Governors.
Year: 1896

page_text: Date of Application, 27th Apr., 1896
Compile Connifinction Inft 27th lon 1007 Accented
Red Ane 1207
Date of Application, 27th Apr., 1898
Complete Specification Loft, 27th Jan, 1907 Accepted, 3rd Apr, 1207
Improvements in Centrifugal Governors.
We, JAMES NOAH PAXMAN and WILLIAM PAXMAN both of the Standard
Iron Works, Colchester, in the County of Essex, Engineers, and JAMES
COURTHORPE PEACRE of 87 Enst Hill Colchester, in the county aforesaid,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to certain improvements in that type of governor used for
controlling the speed of steam engines or other prime movere, in which a helical
spring or springs are used between the balls or weights so that the centrifugal
force of the said balls or weights is balanced by the centripetal action of the
spring or springs. The arins on which the balls or weights are carried are extended
beyond their points of fulcration in the cross head or hody of the governor to form
balance weights, so that the centrifugal force of the balls or weights round their
points of fulcration becomes nil at some point before the centres of gravity of the
balls or weights coincide with the action of the governor shaft which enables
(other things being equal) a longer spring to be employed than is possible in the
ordinary construction, the object being to obtain an isochronons or approximately
isochronous governor. The spring or springs are attached to the governor arms
between the ball or weight and the balance weight at such a point that when the
said arms are in their mean working position the amount of the centrifugal force
of the balls or weights and balance weights is directly taken by the centripetal
action of the springs and thus the pins on which the arms are fulcrated are relieved
of all pressure due to the interaction between the centrifugal forces of the weights
and the centripetal pull of the springs, thus reducing friction to a minimum and
making the governor more sensitive and accurate in its action than would otherwise
be the case.
To enable the speed of the governor to be adjusted, a spring the tension of
which can be adjusted by means of a hand wheel and screw or the like is mounted
independent of the revolving parts of the governor, and is connected either to
the governor spindle or governor body-as the case may be either direot, or
through a lever from which the force of the spring is transmitted through links or
by a cross slide to points on the extensions of the armis of the governor, the said
points being on a line making an angle of about 135% or thereabouts with the
centre line of the said arms.
The stiffness or tension pull in the extension of the spring is so proportioned
that in conjunction with the varying leverage due to the arrangement of its
connection with the governor arms, and also in conjunction with the stiffness of
the springs connecting the governor arms together, that not only can the mean
speed at which the governor comes into action be varied and adjusted by varying
the tension of the independent spring, but the percentage of the variation of speed
between the extreme inner and outer working positions of the governor arms can
be kept constant through the whole range of mean speeds. Further if desired the
percentage of variation of speed between the extreme inner and outer working
positions of the governor arms may be made to increase or diminish as the mean
epeed is altered.
To show the mean speed at which the governor and thereof at which the engine

page_text: is running, an indicator is provided the hand or pointer of which is connected
either directly or indirectly with the adjustable spring controlling the speed of the
governor.
Dated this 27th day of April 1896
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Agent for the Applicants.
ntrifugal Governors.
We, JAMES NOAH PAXMAN and WILLIAM PAXMAN both of the Standard
Iron Works, Colchester in the County of Essex, Engineers, and JAMES
COURTHORPE PEACHE of 87 East Hill, Colchester, in the county aforesaid,
Engineer, do hereby declare the nature of this invention and in what manner
the same is to be performed to be particularly described and ascertained in aud
by the following statement :-
This invention relates to certain improvements in that type of governor used for
controlling the speed of steam engines or other prime movers in which the centrifugal
force of the balls or weights is balanced by a spring or springs.
It is well known that to reduce friction in a spring centrifugal governor it is
desirable that the centrifugal force of the balls or weights, and the centripetal
action of the spring or springs shall be directly opposed to each other without
the intervention of joints or levers.
The balls or weights in some governors as now made are directly tied together
by helical springs. But, although by this means friction due to the interaction
between the balls or weights and springs is reduced to a minimum, yet there is
difficulty in obtaining close regulation of speed with such a governor. The reason
of this is that since the centrifugal force of the balls or weights-the speed being
constant-varies directly as the distance of their centres of gravity from the axis
of the governor shaft, the centrifugal force would not become "nil" until the
centres of gravity of the balls or weights coincided with the axis of the governor
shaft. Now the tension of a helical spring practically varies directly at its
length. Consequently, if the points corresponding with the centres of gravity
of the balls or weights are to be directly tied together by helical springs, it is
obvious that to construct an isochronous governor, it would be necessary to employ
springs that have no length when at rest, which is a "reductio ad absurdum."
In governors of this class as at present constructed it is usual to employ springs
as short as can be made to stand the extension they have to give. But, the tension
of the spring increases at a much more rapid rate than that proportional to the
distances of the centres of gravity of the balls or weights from the axis of the
governor shaft, and consequently the difference in speed between that corresponding
to the inner and outer position of the balls or weights respectively is considerable.
If to avoid this considerable variation in speed the action of the governor is limited
to a relatively very small movement of the balls or weights, then the governor
loses largely in capacity.
One of the objects of our invention is to gain the advantage of absence of friction
due to the direct connection of the balls or weights by helical springs and at the
same time to avoid the disadvantages set out above, i.e. to obtain a governor that
shall be isochronous or as nearly isochronous as may be desired throughout its
range of action.

page_text: To this end we construct the arms of our governor with balls or weights at one
end and balance weights at the other end so that the nett movement of their
centrifugal forces, round the pivot of the governor arms, becomes "nil" at some
point outside the axis of the governor shaft.
Another object of our invention is, as far as possible, to directly balance the
centrifugal force of the balls and balance weights by the centripetal action of the
springs, and for this purpose we locate the points of spring attachment at such a
position of the governor arms, that, in their nean working position, the movement,
of the centrifugal forces of the balls and balance weights shall balance each other
round the point of spring attachment.
In the accompanying drawings which serve to illustrate how our invention is
carried into practice :-
Figure 1 Sheet No. 1 is a diagrammatic view showing the balanced arms of the
governor at the position in which the nett centrifugal moment of the balls and
balance weights become "nil."
Figure 2 Sheet No. 1 is a similar view showing the mean working position of
the balls and balance weights.
Figures 3 and 4 Sheet No. 1 are views in side and back elevation respectively
showing the application of our invention to one form of governor.
Figures 5 and 6 Sheet No. 2 are views in side and back elevation respectively
showing the application of our invention to another form of governor, and
Figure 7 Sheet No. 2.is a broken view showing a further modification.
Figures 8 and 9 Sheet No. 3 aro diagrams showing one method of varying the
leverages between the inner and outer positions of the governor arms.
Throughout the views similar parts are marked with like letters of reference.
The arms A, A, on which the balls or weights B, B, are carried are extended
beyond the points at which they are pivotted in the cross head or body of the
governor as the case may be, to form balance weights C, C. The arms A, A are
connected by means of two springs D, D, located one on each side of the said arms.
The points y, y, at which these springs are attached to the arms A, A, is such that
when the said arms are in their mean working position, the centrifugal forces of
the balls or weights and balance weights is directly taken by the centripetal action
of the springs and thus the pins on which the arms are pivotted are relieved of
all pressure due to the interaction between the centrifugal force of the weights
and the centripetal pull of the springs, thus reducing friction to a minimum and
making the governor more sensitive and accurate in its action than would otherwise
be the case.
In the construction shown by Figures 3 and 4 the arms A, A, carrying the balls
or weights B, B, and the balance weights C, C, are pivotted to the arins e, e, of
the body E of the governor which has no vertical movement but is rotated through
any convenient form of gear. The balls or weights B, B, are connected with the
valve spindle F by means of links, and a cross head F.
In the construction shown by Figures 5 and 6 the governor body E moves
instead of the spindle F the movement of the said body being transmitted to a
lever G which controls the travel of the slide rod Z through any suitable
mechanism such as that shown.
As a modification a slotted cross slide H connected direct to the balls or
weights B, B, as shown by Figure 7 may be substituted for the cross bar F¹ and
the links. The springs D are not shown in this figure.
For effecting changes of speed in the governor we employ an adjustable spring
and transmit its force to the governor arms through leverages which vary with the
position of the balls in such a proportion that the sum of the pull of main governor
springs and of the adjusting spring against the nett centrifugal force of the balls
and balance weights for the inner and outer positions of the governor arms
respectively shall bear a constant ratio to each other throughout the range of the
speed adjusting spring. In other words that the % of variation of speed between
that corresponding to the inner and outer positions of the governor arms

page_text: respectively shall be kept constant throughout the range of speed adjustment
effected by the speed adjustment spring.
In Figures 3, 4, 5 and 6 of the accompanying drawings K designates the
adjustable spring the teusion of which can be adjusted by means of a hand wheel J
and screw, or the like. This spring is carried in a case M mounted on some
fixed parts of the governor stand Y and its one end is connected either to the
governor spindle For the governor body E as the case may be either direct or
through a suitable arrangement of levers, and of its other end is connected to the
'screw J¹.
In the construction shown by Figures 3 and 4 the spring K is connected to the
spindle of the governor through a lever L pivotted to the stand Y carrying the
governor, and in the construction shown by Figures 5 and 6 the spring Kis
connected to the governor body E through a pair of levers L, L, pivotted to the
stand and connected to the lever G.
In Figures 8 and 9 is shown one way of arranging the varying leverages
between the inner and outer positions. Figure 8 shows the governor arms at their
inner position with the speed adjusting spring K acting through a comparatively
small leverage against the centrifugal force of the halls and Figure 9 shows the
governor arms at their outer position with the speed adjusting spring acting
through a bigger leverage against the centrifugal force of the balls.
The stiffness of the spring K is so proportioned, that in conjunction with the
varying leverage due to the arrangement or its connection with the governor arms
and also in conjunction with the tension of the springs connecting the governor
arms together, not only can the mean speed at which the governor comes into
action be varied and adjusted by varying the tension of the said spring K, but the
percentage of the variation of speed between the extreme inner and outer working
positions of the governor arms can be kept constant through the whole range of
mean speeds. Further if desired the percentage of variation of speed between the
extreme inner and outer working positious of the governor arms may be made to
increase or diminish as the mean speed is altered.
To show the mean speed at which the governor is set to act an indicator is
provided the hand or pointer of which is connected either directly or indirectly
with the spring K so as to show its tension.
The indicator may either consist of a scale m carried by the case M enclosing
the spring K and of a pointer n carried by the attachment N by which the spring K
is connected to the controlling sorew Jas shown by Figures 3, 4, 5 and 6 of the
accompanying drawings, or it may consist of a dial mounted on any convenient
fixed part and of a hand or pointer rotating thereon and connected with the spring K
by means of a rack and pinion or other suitable gear.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed, we declare that what we
clain is-
(1.) The improvements in centrifugal governors substantially as hereinbefore
described and for the purpose set forth.
(2.) In a centrifugal governor the arms of which are provided with balance
weights and are connected together by a spring or springs so that the centrifugal
force of the halls or weights is balanced by the centripetal action of the spring or
aprings, the use of nu independent adjustable spring connected indirectly with the
governor arms so as to act against the centrifugal force of the balls or weights as
and for the purpose set forth.
(3.) In a centrifugal governor having arms provided with balance weights and
connected together by a spring or springs in such a manner that the centrifugal
force of the balls or weights is balanced by the centripetal action of the said
spring or springs, and having an independent adjustable spring adapted to act
against the centrifugal force of the balls or weights, the use of an indicator for
showing the mean speed at which the governor is set to act, as set forth.

page_text: (4.) In a centrifugal governor, the combination of the body E, of the spindle F,
of arms such as A carrying balls or weights B at one end and balance weights C at
the other end, of springs such as D connecting the arms A and A together
between the points at which they are pivotted to the cross head or body of the
governor and the weights C, of links such as for their equivalents connecting
the balls or weights B with the cross head on the spindle F, of an independent
spring such as K the tension of which is adjustable by means of a hand wheel J
and screw J', and of a lever such as L connecting the spring K either directly or
indirectly to the moving part of the governor i.e. either to the spindle F or to the
body E according to the type of governor, all combined, arranged and adapted to
operate as and for the purpose set forth.
Dated this 271
ROBERT E. PHILLIPS, Assoc. M. Inst. C.E., M.I. Mech. E.,
Consulting Engineer and Patent Agent,
70, Chancery Lane, London, W.C., Agent for the Applicants.