Improvements in Apparatus for Regulating the Speed of Dynamo- electric and other Machines.
Year: 1890

page_text: Date of Application, 15th Apr., 1890-Accepted, 14th June, 1890
COM LEIE DI DUIFICATION.
[Communicated from abroad by THEODORE MARSHALL FOOTE, of Boston, Massachusetts,
United States of America, Electrician.]
Improvements in Apparatus for Regulating the Speed of Dynamo-
electric and other Machines.
I, HENRY HARRIS LAKE, of the Firm of Haseltine, Lake & Co., Patent Agents,
Southampton Buildings, in the County of Middlesex, 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 and by the following statement :-
The object of this invention is to provide means whereby a dynamo or other
machine may be maintained at a constant speed independent of variation in the
speed of the shaft of the driving pulley connected with the engine or other prime
mover.
To this end the invention consists of the combination, substantially as hereinafter
more fully set forth, with a wheel connected to and rotating with the shaft of the
driving pulley of a series of brake shoes bearing upon the periphery of this wheel and
connected to the shaft of the dynamo or other driven machine, a centrifugal governor
connected with this shaft, and an arrangement of levers and pressure producing
devices, as described, operated by the driver shaft to increase or decrease the friction
of the shoes upon the wheel in accordance with the varying speed of the driving shaft.
It also consists of the arrangement, substantially as hereinafter more fully set forth,
around the wheel connected to the driving shaft, of the pulley from which motion is
communicated from the driver shaft to the work.
In the accompanying drawing:
:-
Fig. 1, is a view in elevation of the mechanism.
Fig. 2, is a longitudinal sectional view of the same.
Fig. 3, is an end view of the friction device.
Fig. 4, is a transverse sectional view of the same and―
Fig. 5, is a longitudinal sectional view of the device for regulating the movement
of the governor arms.
In these several figures the same letters refer to the same parts.
A is the shaft of the driven pulley and B is the driving pulley. This pulley rotates
at a speed which is in excess of that of the shaft A, and is made fast to a sleeve C
rotating on the shaft A. This sleeve carries the wheel D which forms one member
of the friction coupling. The other member of the friction coupling consists of the
brake shoes E attached to the wheel or pulley which is fast on and rotates with
the shaft A.
The device is shown as having three brake shoes encompassing the wheel D,
each of which consists of a plate of sheet metal, a, having some springiness and
faced with a suitable fabric b, for forming a frictional contact with the surface of
the wheel D. Above each of these shoes is pivoted in the pulley F a lever G which
at one end projects from the pulley F and at the other end carries an adjustable
pin c, which bears against the plate a and establishes a frictional contact between the
shoe and the wheel D. The projecting end of each lever G is connected by a
suitable link d with a sleeve I sliding on the shaft B. A strong spiral spring H
surrounds the sleeve I and the other end of the spring bears in a bush K screwed
into a sleeve L fixed on the shaft A. The object of the spring is to force the sleeve I
towards the pulley F and thus through the action of the links, d, and levers G

page_text: to cause the brake shoes to bear with frictional contact on the surface of the
wheel D. To the face of the pulley F on opposite sides of the shaft A is pivoted
a bent lever the longer arm M of which is weighted and acts as the arm of a centri-
fugal governor and the shorter arm N of which bears against the 'end of the sleeve I.
The tension of the spring H can be adjusted by screwing the cap K in or out of the
cap L.
The operation of the device is as follows:-The driver B is driven with a speed in
excess of that desired for the shaft A and pulley F and the dynamo or other machine
connected thereto. The cap K is set in such a position as to cause the sleeve I by
means of the links, d, and levers G to force the brake shoes against the surface of
the wheel D and thereby create sufficient friction to cause the pulley F to rotate
with the wheel D until the pulley F attains the desired speed and at the same
time by the effect of centrifugal force the arms M of the governors are thrown out
sufficiently to cause the arms N to bear against the sleeve I in opposition to the
force of the spiral spring H.
Should the speed of the pulley exceed the desired rate the increased centrifugal
force will operate to throw out the arm M and to cause the arms N to press with
increased force against the end of the sleeve. The spring H will therefore be
compressed the sleeve will move away from the pulley F and by the movement of the
links, d and levers G the pressure of the brake shoes upon the surface of the wheel
is diminished until the brake shoes slip upon the wheel and the pulley returns to its
normal speed.
When the governors are properly weighted and adjusted to the tension of the
spring H the speed of the pulley F will always be maintained uniform, as any varia-
tion in speed will by the action of the governors automatically produce a variation
in the friction between the brake shoes and the wheel D rotating with the driving
pulley the friction increasing when the speed of the pulley falls below its desired
rate and decreasing when this speed exceeds the desired rate.
The efficiency of the device is increased by providing for the adjustment of the
several parts. The tension of the spring I may be adjusted by moving the сар K
on the sleeve M and the movement of the governor arm may be regulated by the
device shown in Figs. 1 and 2 or by the device shown in Fig. 5.
In the device shown in Figs. 1 and 2 there is a spiral spring, o, on the shaft A
which fits within a bush P screwed into the sleeve L and presses against a sliding
sleeve R on the shaft. To this sleeve is pivoted a lever S the end of which rests upon
the sleeve L which is bevelled off and has pivoted to it at right angles thereto a short
arm, e, which bears against the end of the governor arm. The tension of the spring O
can be regulated by the movement of the cap P to determine the position of the short
armi, e.
In the device shown in Fig. 5, the spring O, is not used but the sleeve R can bè
fixed in any desired position in the shaft and can be moved to that position by means
of the pivoted collar T which has a handle, f, which moves "over the graduated
arc, g.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, as communicated to me
by my foreign Correspondent I declare that what I claim is :-
First. The combination of the shaft A, the sleeve C loose on said shaft, the driving
pulley B'fast on the sleeve C, the wheel D connected to the sleeve and forming one
member of the friction clutch, the wheel F fast on the shaft A, the brake shoes
connected to the wheel F and bearing upon the surface of the wheel D, the sliding
sleeve I, the spring H bearing against this sleeve, the sleeve L and adjustable bush K,
the pivoted levers G provided at one end with pins, c, which bear against the brake
shoes * and connected at the other end by links d, to the sleeve I and the centrifugal

page_text: governor pivoted to the pulley F and formed of the weighted arms M, and the arms N
bearing against the end of the sliding sleeve I.
Second. The combination with the wheel D of the brake shoes, levers G acting upon
the same, and the pulley F covering these shoes.
Dated this 15th day of April 1890.
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicant.