Improvements in Changeable Gear for Bicycles and similar Driving Mechanisms.
Year: 1898

page_text: Date of Application, 21st Apr., 1898--Accepted, 17th Sept., 1898
COMPLETE SPECIFICATION.
Improvements in Changeable Gear for Bicycles and similar Driving
Mechanisms.
We, FRANCIS HENRY MURPHY, Electrician, and MASON ROUNDS PIERCE, Builder,
both residing at 221, East 126th Street, in the City, County, and State of New
York, United States of America, 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 changeable gear for bicycles and similar driving
mechanisms, and it has for its object to provide a simple and improved gear of this
character which will be especially adapted for convenient and effective use upon
bicycles of the "chainless" type.
The invention is fully disclosed in the following specification of which the
accompanying drawing forms a part, in which the separate parts of our improve-
ment are designated by the same letters of reference in each of the views, and
in which;-
Fig. 1, is a side elevation, partly in section, showing a bicycle provided with
our improved gear; and
Fig. 2, is a detail top or plan view, partly in section, of the gear mechanism.
In the drawing forming part of this specification, A designates the frame of the
machine, which may be in the main of any suitable or adapted construction
embodying the tubular head, a and the lower tubular front bar, a¹, extending from
the head to the crank shaft bearing. B designates the crank shaft, which carries,
at one side the frame of the machine, a bevel gear, C, having upon its inner face
an outer gear, c, within the plane of which is arranged an inner gear c¹, of lesser
diameter. D designates a shaft, which is arranged longitudinally with respect
to the frame of the machine, preferably in bearing brackets, e, projecting from
one of the lower rear side bars, E, of the frame. At its rear end the shaft D
carries a bevel gear, d, meshing with a corresponding bevel gear, f, upon the
shaft, F, of the main driving wheel, and at its front end the shaft 1) carries two
bevel pinions, G G', respectively, of varying diameter, which pinions are separated
a suitable distance and respectively mesh with the different gears c c¹ upon the
main gear. The pinions are loosely mounted upon their shaft and are adapted to
be engaged by an intermediate clutch H, carried upon the shaft D) and adapted
to be thrown into or out of engagement with the respective pinions.
The clutch is operated by a transverse lever, I, which may be pivotally mounted,
as at i, in the frame bars E, which lever preferably engages the clutch by means
of an end point, ¹, received by a circumferential groove or recess, h, upon the
clutch.
It will be understood that by operation of the lever I the clutch may be moved
longitudinally upon its shaft to bring its clutch ends, h¹ h¹ into engagement with
the corresponding inner clutch faces, c², of the respective pinions, and that the
clutch may be withheld from engagement with either of the pinions in a position
intermediately between the same.
,

page_text: The lever I is operated by a worm shaft, J, mounted in longitudinal position
and bearing in the frame portion E, the lever being provided with a pin, as at 3,
engaging the worm.
The front end of the worm shaft projects within the tubular bar a¹ of the frame,
as at j, and is connected, by a joint K, with the lower end of a shaft, L, arranged
longitudinally within the tubular bar a', the top end of said shaft L being con-
nected by a similar joint, K', with the lower end of a shaft, M, arranged within
the tubular head a and extending to the top of the same, at which point it is
provided with a detachable key, m.
By turning the key m, the shaft M is revolved and in turn revolves the shaft L
which operates to revolve the worm shaft J and thereby cause the lever
throw the clutch into engagement in either direction, as desired.
to
It will be understood that the sliding clutch is withheld from rotary movement
by a feather, d', or other suitable engaging device upon the shaft D.
The angular joint connections between the shafts by which the worm is operated
may be of any suitable or adapted construction, but we prefer to provide an
improved rotary angle joint connection of the construction herein shown, which
embodies a connecting link k having its ends respectively bifurcated, as at k
the bifurcations being at right angles to each other and pivotally receiving end
fingers or flanges, upon the ends of the respective shaft sections. The ends
of the shaft sections are thus pivotally connected, at right angles, to the connect-
ing link, so that the rotary movement of one shaft connection will be communi-
cated to the next shaft connection at an angle. In this construction, the adjoining
ends of the shaft sections will have a slight play, the construction being especially
adapted for a sectional shaft such as that herein embodied and enclosed within a
casing formed by the tubular bars.
The operation and advantages of our invention will be readily understood. The
gear may be instantly changed by the rider without dismounting, by simply
turning the key m, to either a high or low speed. For instance, in ascending a
grade, the rider can simply turn the key without dismounting, to throw the low
speed gear into operation and thus lessen exertion. In like manner the change-
able gear may be operated to disconnect both gears and permit the machine to
run free in coasting without movement of the pedals; or, in coasting, the low
gear can at any moment be thrown into play and thus enable the speed of the
machine to be limited or controlled.
The worm connection between the gear operating mechanism and the clutch
will serve to effectively retain the clutch in any position to which it may be
adjusted. Thus, by operating the mechanism to adjust the clutch to a position
intermediately between the pinions, and removing the detachable key m, the
machine will be virtually locked against use, inasmuch as the driving wheel will
then be entirely disconnected from the driving gear.
The beveled gear and clutch and the worm mechanism may be housed within a
suitable casing connected to the frame of the machine.
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
claim is:
-
1. An improved changeable gear of the class described, comprising the main
shaft carrying bevel pinions of different diameters, the crank shaft transversely
mounted with respect to the main shaft and carrying a gear embodying gears of
different diameters respectively meshing with said bevel pinions, a clutch mounted
upon the main shaft intermediately between said bevel pinions and adapted to
respectively engage the same, and mechanism for operating said clutch, sub-
stantially as and for the purpose set forth.
2. An improved changeable gear of the class described, comprising a main
shaft carrying bevel pinions of different diameters, a crank shaft transversely
mounted with respect to the main shaft and carrying a gear embodying gears of

page_text: different, diameters respectively meshing with said bevel pinions, a clutch mounted
upon the main shaft intermediately between said pinions and adapted to respec-
tively engage the same, an operating lever transversely mounted with respect to
said clutch, a longitudinally arranged worm gear engaging said lever, and means
for operating said worm gear, substantially as and for the purpose set forth.
3. An improved changeable gear for bicycles, comprising the main gear shaft
carrying bevel pinions of different diameters and mounted in a longitudinal
plane, a transverse crank shaft carrying a gear embodying gears of different
diameters respectively meshing with the bevel pinions, a clutch mounted upon
the main gear shaft intermediately between said pinions and adapted to respec-
tively engage the same, a lever transversely mounted and engaging said clutch,
a worm gear longitudinally mounted and engaging the lever, and an operating
shaft extending upwardly from said worm gear and embodying jointed sections,
substantially as and for the purpose set forth.
4. In a bicycle, the combination with the frame of the machine embodying the
tubular bars and carrying the main gear shaft having bevel pinions of different
diameters, a crank shaft carrying a gear having gears of different diameters
respectively engaging said pinions, a clutch mounted upon the main shaft and
intermediately between said pinions and adapted to respectively engage the same,
a transverse lever engaging said clutch and a longitudinally arranged worm gear
engaging said lever, of a sectional operating shaft formed of sections respectively
housed within the tubular frame bars and connected by rotary joints, said enclosed
sectional shaft being connected with the worm gear and being provided at its
terminal top end with an operating key or head, substantially as and for the
purpose set forth.
5. In a bicycle, the combination, with the tubular frame bars, and with gear
mechanism, of a sectional operating shaft housed within said tubular frame bars
and formed of sections extending through the respective tubular bars and con-
nected by rotary joints, said sectional shaft being connected at its lower end with
the gear mechanism and provided with a projecting key or head at its top end,
substantially as and for the purpose set forth.
6. In a bicycle, the combination, with gear mechanism, and a clutch or inter-
locking mechanism for throwing the same into and out of engagement, of an
operating shaft or mechanism connected with said interlocking mechanism.
and operating to retain the same either in or out of operative position, said shaft or
operating mechanism being enclosed or housed within the tubular bars of the
frame and provided at its top end with a removable key, whereby said gear and
its operating mechanism will serve also as a lock for the bicycle, substantially as
and for the purpose set forth.
7. In a mechanism of the class described, an operating shaft embodying sections
arranged at different angles, said sections being connected at their ends by a
pivotal intermediate link to the respective ends of which the ends of the shaft
are respectively pivoted at right angles, substantially as and for the purpose set
forth.
3000
WHEATLEY & MACKENZIE,
40, Chancery Lane, London, W.C., Agents.