Improvements in Differential Gearing.
Year: 1891

page_text: Date of Application, 19th May, 1891-Accepted, 11th July, 1891
COMPLETE SPECIFICATION.
Improvements in Differential Gearing.
1 EDWARD KENWORTHY DUTTON, of the firm of Dutton and Fulton, of
Number 1 St. James Square, Manchester, in the County of Lancaster, Consulting
Engineers and Fellows of the Institute of Patent Agents do hereby declare the
nature of this invention (communicated to me from abroad by Cyra B. Wattles,
of 1048 Elizabeth Avenue, Elizabeth, Union County, State of New Jersey, one of
the United States of America, Engineer,) and in what manner the same is to be
performed to be particularly described and ascertained in and by the following
statement and accompanying drawings:
The object of this invention is to provide a simple and effective means of
controlling the movement of the driven member or follower of a train of differential
gearing.
The invention consists essentially in the combination with a train of differential
gearing comprising a driving member or driver, an intermediate member and a
driven member or follower, of mechanism actuated by the driver for controlling the
movement of the intermediate to determine the movement of the follower. It
includes also a special mechanism for controlling the movement of the follower;
the same comprising a worm wheel applied to the intermediate, and a worm
meshing therewith and actuated by an adjustable friction device applied to the
driver, whereby the rotation of the intermediate may be varied at pleasure to
regulate the speed of the follower.
Heretofore, the speed of the intermediate member of a train of differential
gearing has been varied by means of an independent braking device applied
thereto; but by my invention the controlling device is actuated by the driving
member of the train, requiring only a slight effort on the part of an attendant
to adjust the same and thereby vary the movement of the driven member in the
desired manner.
The annexed drawings show my invention applied to differential trains of
both spur and bevel gears, the controlling mechanism in each case being driven by
a friction device applied to the driving member of the train. To avoid any
ambiguity herein in the reference to the different members of the train of gearing,
the term intermediate" is used to designate that member operating indepen-
dently of the driver and governing the movement of the follower, regardless of its
position in the train.
Fig. 1 is a side elevation of a train of bevel gearing provided with a worm
controlling mechanism, the worm wheel being in section through its centre line;
Fig. 2 is an end elevation of the same viewed at the right of Fig. 1, and
Fig. 3 an end elevation of the same viewed at the left of Fig. 1.
Fig. 4 is a central longitudinal section of a similar train of gearing, showing the
worm gearing operated by a different friction device from that shown in
Fig. 1 and
Fig. 5 is an end elevation of the same viewed at the left of Fig. 4, and with the
gear removed to expose the others more clearly.
Fig. 6 is a side elevation (that portion below the line X X being in central
longitudinal section) of a differential train of spur gearing showing a brake wheel
and a brake shoe operated by the driver applied to the intermediate; and
Fig. 7 is an end elevation of the same viewed at the left of Fig. 6.
In Figs. 1, 2 and 3, the bevel gear a, which constitutes the driver, is mounted
loosely upon the shafts and provided with a sleeve g to which is secured an
electric motor armature h. Upon the same shaft is mounted loosely a similar gear b,

page_text: between which and the gear a is interposed the bevel gear c meshing with both of
said gears and mounted upon a stud d projected radially from a hub e, which is fixed
to the shaft s.
It will be observed that any difference in the speed of rotation of the gears a and b
causes the lateral motion of the gear c with its stud d around the shaft s, thereby
causing the rotation of the shaft upon which they are fixed.
The worm controlling device is shown applied to the lateral gear, the worm
wheel being secured upon the hub of such gear, and the worm i being actuated by
a friction driver in contact with a flange j upon the driving gear a. Such friction
driver consists in a ring k fitted loosely to a hub upon a shaft m, by means of
which it is pressed toward the flange with the desired force. The shaft mis
connected with the worm shaft by cog wheels o, and the operation of the friction
device is to rotate the worm and the wheel at a given speed; to determine the
speed of the shafts by means of the follower c of the train.
q
The hub 7, upon which the friction ring is mounted, is provided with a brake
groove P to which a shoe 7 is applied, and pressure upon such shoe by means of the
lever operates to retard or to actually arrest the movement of the friction hub and
the consequent rotation of the worm wheel.
By inclining the thread of the worm in the required direction, the worm wheel
and its attached bevel wheel may be rotated in the same, or in a contrary,
direction to the driver a, and the speed of the shaft s thereby increased or
diminished.
The hub is shown fitted to the shaft m by a spline m³, and the brake lever is
mounted upon a swivel fulcrum so that it may be used at pleasure to move the hub
longitudinally upon its shaft. With such construction, the hub may be shifted
longitudinally upon the shaft m to remove the ring from contact with the driving
flange, if it were desired to hold the worm stationary. By such means, the waste
of energy involved in the use of a brake would be avoided during the normal
operation of the gearing. Such detachment of the friction driver from the flange j
does not release the coutrolling gear, as the worm operates normally as a locking
device, and holds the worm wheel stationary in every position to which it is turned.
In the construction above described, the gear c, the stud d of which is fixed upon
the shaft, constitutes the follower; the gear 6 being the intermediate and the
gear a the driver: but in the train shown in Figs. 4 and 5, the lateral gear b, which
is fixed upon the shaft, constitutes the follower;. the gears c, the studs of which
are carried by the loosely mounted hub e, constituting the intermediate; and the
gear a the driver, as in the preceding figures. In this construction, a worm ringj
encloses the gears e and is held concentric with the hub e by the two studs d, the
gears c balancing the frictional pressure of the hub upon the shaft. The driving
Hange for actuating the worm is formed as a disk upon the back of the driving
gear a, and a friction wheel in contact with the disk is fitted to a spline upon a
shaft which is connected with the worm by cog wheels o. A lever, forked at
its outer end to embrace the grooved hub of the friction wheel t, is provided to
shift the latter to and from the centre of the disk j, thus varying the speed
imparted to the worm i, (which, with its shaft n, is omitted from Fig. 4).
A clearance w is formed in the disk j adjacent to the shaft s to remove the
friction wheel from contact with the disk when required; which wholly arrests
its motion and permits the worm to hold the worm wheel stationary. In such
position, the follower is obviously driven at the same velocity as the driver a
and in the opposite direction; while the inclination of the teeth upon the worm
may be designed to either increase or diminish the velocity of the follower, when
the worm is rotated.
The armature is shown in Fig. 4 connected with the sleeve g' by cog wheels ',
which may be proportioned to produce a relatively slow motion of the sleeve when
the armature is rotated rapidly. Such arrangement is especially adapted for use
with a fast running motor; while the construction shown in Fig. 1 is better adapted
for a slow running motor, as when used for a tram car.

page_text: It will be seen that the power derived from the use of a worm renders a friction
driver for the same (as shown herein) entirely applicable to regulate the motion of
the controlling gear; although a friction driver may not be adequate to transmit
the entire power required to propel the shafts. Such an application of the friction
driver is possible because the differential gearing transmits a great part of the
directly to the shaft s;. while the worm controlling or regulating mechanism operates
only to vary the speed of the shaft, where the power supplied to the driving member
of the train is not sufficient to drive the shaft at its normal speed, or where it is
desired to vary the speed of the latter for other reasons.
power
In Figs. 6 and 7, capital reference letters are used, to indicate the parts of the
mechanism corresponding to siinilar parts in the constructions already described.
In the construction shown in these figures, the sleeve G, mounted upon the shaft S
and carrying the gears, C, constitutes the driver of the train; the gear B, mounted
loosely upon the shaft, the intermediate; and the gear A, which is keyed upon the
shaft, the follower.
The sleeve G is provided, adjacent to the gear A, with the radially projecting
arms E carrying the studs D upon which the gears C are mounted; and the other
end of the sleeve is provided with the cog wheel I from which the power is derived,
the latter being provided at its outer side with the flat face J for the friction
wheel T to roll upon. The hub of the gear B carries the brake wheel F to which
is applied the brake shoe K by means of a lever L. The shaft M of the controlling
mechanism is actuated, like the shaft m in Figs. 4 and 5, by means of the friction
wheel T, and connected with the shaft U by means of the cog wheels O; at its
outer end, directly above the outer end of the brake lever L, it is provided with a
grooved collar N to which is fitted the split sleeve Q having the projecting toe I
and clamped movably thercon by means of bolts P. The friction of the sleeve Q
upon the collar N produced by the rotation of the shaft M causes the toe I to press
the lever L downward with a force depending upon the speed of rotation of the said
shaft, thereby retarding the motion of the intermediate B (the tendency of which
is to rotate with the driver of the train) and causing a corresponding variation in
the speed of the follower A.
From the above description it is obvious that the controlling mechanism may be
applied to different gears in the train to produce the desired speed of the follower;
and that the speed of such controlling mechanism may be varied in a practical and
convenient manner by the employment therein of a friction driver, which is the
most desirable agent for effecting the desired variation, as it operates without shock
or jar. It will also be seen that the class of gearing composing the train is
immaterial, the controlling mechanism being equally applicable to spur and bevel
gearing. It is evident that the principal and distinctive feature of my invention is
primarily the actuation of the controlling mechanism for the intermediate by the
driving member of the train; and secondarily, the employment of a friction device
applied to the driver, and the worm and worm wheel applied to the intermediate
member and actuated by the said friction device.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I declare that what 1
claim is,
1. The combination, with a train of differential gearing comprising a driver, a
follower and an intermediate member, of a controlling mechanism applied to the
intermediate member of the train and actuated by the driver, with means for varying
its speed in relation to that of the driver.
2. The combination, with a train of differential gearing comprising a driver, a
follower and an intermediate member, of a worm wheel applied to the intermediate
member, a worm for operating the same, and mechanism actuated by the driver
for rotating the worm, with means for varying its speed in relation to that of the
driver.
3. The combination, with a train of differential gearing comprising a driver, a

page_text: follower and an intermediate member, of a worm wheel applied to the intermediate
member, a worm for operating the same, and a friction device actuated by the
driver for rotating the worm, with means for varying its speed in relation to that
of the driver.
4. The combination, with a train of differential gearing comprising a driver, a
follower and an intermediate member, of a worm wheel applied to the intermediate
member, a worm for operating the same, a friction disk rotated with the driver, a
friction wheel held adjustable radially in contact therewith, and a connection from
the said friction wheel to the worm for actuating the same.
5. The combination, with the shafts, of the bevel gear a mounted loosely
thereon and the bevel gear fixed thereon, the hub e mounted loosely upon the shaft
between such gears and provided with radial studs d, interposed gears & upon the
studs and meshing with the gears a and, a worm wheel and worm connected with
the gear b, a friction disk rotated with the gear ", an electric motor for driving
such disk and gear, and a friction wheel pressed upon the disk and movable to and
from its centre, with a connection to the worm to control the speed of the worm
wheel and its attached gear, as and for the purpose set forth.
Dated this 16th day of May 1901
DUTTON & FULTON,
1. St. James' Square, Manchester, Agents.