Improvement in Changeable-speed Gearing.
Year: 1897

page_text: Date of Application, 15th June, 1897-Accepted, 4th Sept., 1897
Improvement in Changeable-speed Gearing.
I, FRANK HOWARD LEFROY, of No. 100 Broadway, New York, in the county and
State of New York, United States of America, Gentleman, 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:-
This invention relates to Improvements in Changeable-Speed Gearing for
Bicycles and Driven Mechanism, and it is embodied in the construction and
arrangement of parts hereinafter described, and definitely pointed out in the
claims.
My invention is designed as an improvement on that class of gearing wherein
a multiple-gear is employed having associated therewith an adjustably-supported
power-transmitting member in the form of a sprocket or gear wheel; and the
aim and purpose of the invention is to furnish an improved, strong, compact, and
efficient changeable-speed gearing especially adapted for use as a driving device
in connection with a power-shaft of a bicycle or other crank-actuated vehicles
and embodying, among other novel instrumentalities, adjusting means which will
enable a positive and accurate dual adjustment of the power-transmitting member
to be made at one operation, thereby obviating the employment of a multiplicity
of parts or delicate mechanisms for securing such adjustment.
In the drawings accompanying and forming part of this specification, Figure 1
is a longitudinal vertical section of the device applied to a crank-shaft, parts
being shown in elevation. Fig. 2 is a sectional view, on the line, Fig. 1,
with parts broken away. Fig. 3 is a detail view of a part of the cam member
of the adjusting device. Fig. 4 represents in details the other parts of the
adjusting device.
Similar characters designate like parts in all the figures of the drawings.
For convenience I have shown my improved changeable-speed gearing applied
to the crank-shaft of a bicycle, a portion only of the framework of the bicycle
being illustrated in the drawings; and I desire it to be understood that my
improvements are adapted for use in connection with a wheel-shaft or power-shaft
of any driven or driving mechanism.
In the drawings A represents a crank-shaft having a crank A' thereon; B, the
crank-shaft sleeve; C, the bearing; and D, one of the standards of the bicycle-
frame, all of which may be of any usual or suitable construction.
The bearing C is shown located a short distance from the crank A¹; and on the
intermediate portion of the shaft A is fixedly secured a multiple or stepped gear E,
comprising a series of peripherally-toothed disks or sections (herein shown as
three in number and designated by e, e¹, and e², respectively) of different diameters.
Secured to the end of the sleeve B is a rigid frame or plate F, having an annular
This frame or
flange f, which is shown secured to the sleeve B by set-screws.
plate extends above and below the sleeve and has vertical guide-grooves fl
and therein on opposite sides, respectively, of said !sleeve.
The driving member, which is herein shown as a sprocket-wheel and which is
designated in a general way by G, surrounds and is rigidly secured to the rim ǹ

page_text: of a drum H, formed with a central opening through which the shaft A passes,
and which opening is of a diameter greater than that of the largest gear-section e³
of the multiple gear E.
On the inner face of the rim of the drum H are a series of equidistantly-
disposed cleats or dovetailed guide-ribs-h', preferably four in number and extending
in parallelism with the axis of the shaft A.
Fixed to the internal periphery of the drum H is an internal or ring gear K
having teeth and also having dovetailed or retaining grooves into which the
cleats or guides extend and which facilitate transverse movements of the ring-
gear K relatively to said drum H. The pitch diameter of the ring-gear K is
substantially equal to the pitch diameter of the section e² of the multiple-gear E.
The external diameter of the ring-gear is such as to closely, but loosely, fit within
the drum H, and the width thereof, between the inner and outer faces of said rim,
is substantially equal to one-third of the depth of the central opening of the
drum H.
In the annular vertical face of the ring-gear K is formed an annular channel
in which is seated a ring-shaped locking-plate ³, whose inner edge projects a
short distance over the channel, for a purpose hereinafter described.
To support the drum H, I employ a supporting-disk L, which is located at the
inner edge of the drum and is of a diameter greater than that of the drum. The
outer edge of the supporting-disk is formed with a lateral plate 7, tapered or
inclined on its end and overlapping the periphery of the drum H, and constituting
one section of a bearing of the drum.
L' designates the other section of the bearing, and consists, conveniently, of a
ring having an inwardly-extending inclined portion at its outer edge, said ring
being internally screw-threaded at its inner edge and engaging threads on the
periphery of the other bearing member or ring L.
A suitable annular groove is formed in the periphery of the drum, registering
with the groove formed with the plate-disk and the ring L'and constitutes in
connection with said ring and disk, a raceway for the bearing-balls L².
The disk L has an opening in its center corresponding with the opening in the
flange of the drum and is carried by the plate or frame F through the instru-
mentality of the headed bolts m, passing through the slot f¹ in said frame into the
disk, this connection facilitating a limited conjoint vertical movement of the
disk L, ring K, and drum H.
The frame or supporting plate F closes the opening in the disk, L, which latter
slides on and is arranged in close contact with the former and thereby constitutes
a dust-guard for the gearing.
For preventing admission of dust to the gearing from the opposite end of the
device a dust-plate O is provided, which is shown as a circular cap of a diameter
greater than the opening in the rim h of the drum and is secured on the shaft
between the gear E and the crank. (See Fig. 1 of the drawings.)
This
As a simple and convenient means for effecting, simultaneously, a vertical and
lateral adjustment of the ring-gear K, drum H, and disk L, I employ adjusting
instrumentalities constructed and organized as follows: A disk or cam-wheel P
is journaled on a pin or shaft 7, mounted in the lower portion of the supporting-
frame F. This disk or wheel has a grooved periphery around which a suitable
actuating cord or chain (not shown) is passed. The wheel P is formed with a
cam-path p, properly shaped as to pitch and contour to effect a step-by-step
movement of the adjusting or connecting member engaging therein.
adjusting or connecting member for effecting the vertical adjustment of the parts
preferably consists of a pin or bar Q, having a channel q in its under face
extending its entire length, the inner portion of which is enlarged into a
cylindrical chamber or groove q¹. The inner end of the pin Q is passed through
the slot in the frame or plate F and is fitted with a screw-thread which takes
into a threaded opening in the disk L. A bevelled flange q² is formed on the pin,
which fits the outer face of the groove 2 and serves to form the connection

page_text: between the support F and disk L in a manner similar to the bolt above referred
to. This pin passes into and through the cam-path of the disk P, and as
the disk is turned the pin is made to follow in the path and respond in its
movement to the various pitches of the path, thereby rising and falling at certain
points, while at other points remaining stationary as the disk P is moved.
To effect the transverse movement of the ring K, a flat sliding arm R is
employed, having a bead r on its upper edge, which is located in the cylindrical
portion of the channel in the pin Q. The arm extends below the plane of the pin
and has three notches r¹, formed in its under edge within which one wall of the
cam-path enters. On the outer end of the arm R is a yoke R', comprising
oppositely-extending curved arms, which are loosely fitted in the channel k² of
the ring K and extend substantially above the plane of the centre of the ring on
opposite sides, thereby forming an extended connection between the arm and ring
and holding the latter in proper position during adjustment to prevent binding
or cramping.
On the wheel or disk P are struck up two inclined tongues or projections s,
formed at the bearing or moving wall of the cam-path, the same extending
laterally a distance equal to the distance between the grooves rl in the arm K.
These inclined tongues are so arranged that as the ring K has been raised to a
position to throw its teeth in line with the next larger gear el or e² the tongues
will enter the adjacent grooves r¹, and, owing to their inclination, will carry that
portion of the arm lying between the groove r through the opening in the
wheel P, formed at the tongue and thereby force the arm and ring one step
outward and on to the alined gear, the ring sliding on the guides of the drum.
In operation as the wheel P is turned the pin Q is raised or lowered, as the case
may be, adjusting the ring-gear K so as to engage the proper section of the
multiple-gear E. The ring-gear is moved laterally in the manner described, and
the engagement thereby effected.
It will be seen that a very positive and accurate adjustment can be effected.
and that the parts are of a relative strong and substantial nature, while the space
occupied by the mechanism is small. In fact the mechanism can be readily
applied to many existing machines.
While I have shown mechanism for effecting but three adjustments or variations
it will be understood that any convenient number can be had by obvious changes,
I desire it understood that many changes and alterations can be made in the
parts and substitutes for those shown and described, without in the least departing
from the nature and principle of my invention.
Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what I
claim is:-
1. A changeable-speed gearing comprising a shaft; a multiple-gear thereon;
a driving-wheel; an internal gear connected with said driving-wheel; and means
for shifting the gear longitudinally of the shaft and independently of the wheel,
and for shifting the driving-wheel and gear transversely of said shaft.
2. The combination, with a shaft, of a multiple-gear; a driving-wheel; a ring-
gear loosely mounted within the driving-wheel; a fixed support; a sliding
connection between the fixed support and the wheel; a rotary disk having a
cam-path and inclined lateral projections; a connection between the disk and
wheel; and a longitudinally-shiftable arm connected to the ring-gear and
engaging the cam-path, and also having notches in which the said inclined
projections engage, for effecting a longitudinal movement thereof.
3. In a changeable-speed gearing for driving mechanisni, the combination,
with a frame and a shaft, of a multiple-gear on the shaft; a drum surrounding the
gear; a support on the frame; a shiftable disk on the support; an operating
connection between the drum and disk; an internal gear loosely mounted on
the interior of the drum; means for moving the drum, disk, and gear transversely

page_text: of the shaft; means for moving the internal gear longitudinally of the shaft and
independently of the drum; and a dust-cap in connection with said drum.
4. A changeable-speed gearing comprising a power-shaft; a multiple or stepped
gear fixed to said power-shaft; an internal gear of a pitch diameter greater than
the greatest pitch diameter of the multiple-gear and supported for movement
longitudinally and transversely of the power-shaft; a driving-wheel carried by
the internal gear; a rotary disk having a stepped cam-path for shifting the
internal gear transversely of the power-shaft and having laterally-projecting
portions for effecting an adjustment of the internal gear longitudinally of the
shaft at successive points in the rotative movement of the cam-plate; and a
shiftable connection between the internal gear and disk and adapted to be
actuated by said disk.
Doted this 15th dox of Tune 1807
HASELTINE, LAKE & Co.,
45 Southampton Buildings, London, W.C., Agents for the Applicant.