Improvements in Driving Gear for Cycles and other Machinery.
Year: 1896

page_text: Date of Application, 8th Apr., 1896
Improvements in Driving Gear for Cycles and other Machinery.
I, JAMES WILLIAM DUNCAN, of No. 2792 Catherine Street, City of Montreal,
Dominion of Canada, Forwarder, do hereby declare the nature of this invention to
be as follows:-
The object of this invention is to provide gear for cycles and other machinery
which produces rapid rotation of a shaft with a minimum expenditure of power.
In order to make the description of the invention more easily understood I will
describe it as applied to a bicycle, although it can be adapted to other uses as will
be understood.
The invention comprises the usual crank-shaft, preferably journalled in ball
bearings forming part of a bracket, and conveniently fitted on the framework
between the two supporting wheels. A bevel-wheel is fitted to the shaft and
meshes with a similar wheel fitted to a shaft which conveys the motion to the
drive wheel by means of bevel-gear at its other end. The ends of the crank-shaft
project through the bearings, at each side of the bracket, eccentrically and are
each fitted with a small tooth-wheel which projects through the annular surface of
the bearing. Eccentric straps forming the hubs of the cranks fit over the outer
periphery of the bearings on the bracket, and each has an internal annular rack,
which engages the small projecting tooth wheels. The strap is preferably provided
with annular grooves to carry balls which run in contact with the outer surface of
the bearings on the bracket.
When the cranks are operated, the annular racks in the crank hubs engage the
projecting small tooth-wheels and rotate them and the crank-shaft from which the
motion is conveyed to the driving-wheel as aforedescribed.
When the mechanism is used in connection with machinery other than cycles,
the ball bearings may be dispensed with and a gear-wheel or pulley take the place
of the cranks; but a crank or cranks may be used if desired.
Dated this 8th day of April 1896.
W. H. MUNNS,
Agent for Applicant.
Improvements in Driving Gear for Cycles and other Machinery.
I, JAMES WILLIAM DUNCAN of No. 2792 Catherine Street, City of Montreal,
Dominion of Canada, Forwarder, 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 means for securing a faster rotation of the usual
driving wheel or sprocket of a bicycle or of similar driving gear usually operated
Price 8d.1

page_text: by a crank and provides an arrangement whereby the speed of rotation of the
initial operating part or crank and the usual sprocket or driving wheel rotated by
it is considerably augmented.
In the drawings hereunto annexed and forming part of this specification,
Figure 1, is a side elevation of a bicycle provided with my improved running
gear:
Fig. 2, a side elevation of the operating parts with retaining-plate removed and
hub of crank partly broken away;
Fig. 3 a longitudinal section of the operating parts on line Z Z, Fig. 2; and
Fig. 4, a detail longitudinal section similar to Fig. 3, but shewing a different
form of initial operating part.
I have chosen to show my invention as applied to the running or operating gear
of a bicycle; but it will be readily understood that its application is not confined
to such mechanism, since by changing the form of the initial operating part it can
be used in connection with shafting and rotary mechanism and devices of various
kinds.
a is the usual transverse crank axle or shaft of a bicycle operating gear, in this
case shewn as composed of bevel gear wheels and shafting instead of sprocket
wheels and drive chain. This axle a is carried in bearings in the frame of the
machine and carries a bevel gear wheel e adapted to internesh with a similar
wheel d on the shaft e, running rearward to operate through other gear connections
the hind wheel of the bicycle.
Each end of the shaft a passes eccentrically through a solid bearing f, projecting
laterally from the side of the frame, on which solid bearing the hub of the crank
or cranks g or other initial operating part is mounted to revolve.
The hub of the crank or other initial operating part is constructed to present an
internal periphery or face carrying gear teeth g' preferably formed on a ring piece g²,
inclosed by two side pieces 93 9'; or such ring can be formed in one piece with the
outer side piece g' with which ring and side piece the crank-arm proper is also
preferably formed and the whole secured together in any desired way. The side
pieces are centrally perforated to fit the bearing fand this latter is cut away, as
at, to accomodate a pinion h, rigidly mounted on the shaft a and in intermeshing
relation with the gear teeth g' of the crank.
The parts are held in place preferably, by means of an outer retaining plate k,
secured in any desirable way to the end of the bearing f.
In Figure 4 I have shewn the initial operating part in the form of a pulley m,
the hub portion of the crank furnishing all the essential parts when rotation is
secured by means of a driving belt such as indicated in section at n.
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 I
claim is :-
(1) In driving gear for bicycles and the like, the combination with the supporting
frame and axle or part to be rotated, of a solid journal bearing projecting from
said frame, an eccentric recess in said journal having an opening centrally of the
width of the periphery thereof leaving solid continuous bearing surfaces of the
same diameter on each side of same, the axle or part to be rotated passing through
the bearing and eccentric space therein, a pinion rigidly mounted on said axle
within said space, and the crank or initial operating part mounted evenly on each
of the continuous bearing surfaces of the bearing and being centrally toothed to
engage said pinion, and a retaining plate secured to the end of said journal bearing
for the purpose set forth.
(2) The combination with the frame, of axle a, suitably supported, a bearing f
in one with the frame and projecting laterally therefrom, an eccentric recess in
said bearing having an opening centrally of the width of the periphery thereof
and leaving continuous bearing surfaces on each side of same, the axle passing
eccentrically through such bearing and through the recess therein, pinion & rigidly

page_text: mounted on said axle within said space, the hub of a crank composed of side
pieces 99, centrally perforated and mounted to revolve on the bearing surfaces
of said bearing and ring pieces bolted together and the latter having gear
teeth on its inside face to intermesh with said pinion; and a retaining plate k
secured to the end of said bearing for retaining the parts in place, for the purpose
set forth.
W. H. MUNNS,
Agent for Applicant.