IMPROVEMENTS IN BICYCLES APPLICABLE TO TRICYCLES & OTHER VELOCIPEDES
Year: 1885

page_text: I, MICHAEL JACKSON WHEATLEY, of 8 Winterbottom Street of South Shields in.
the County of Durham Engineer do hereby declare the nature of my invention for
IMPROVEMENTS IN BICYCLES APPLICABLE TO TRICYCLES & OTHER VELOCIPEDES
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 enable riders of short stature to ride a bicycle
with an increased speed without increasing the size of the driving wheel beyond
the size they can conveniently stride; while the pedalling may remain at the
normal rate and in the case of racing bicycles; to enable any rider to gear up his
machine from or below the normal size of wheel to any diameter he may desire.
The general principle of my invention consists in applying speed gearing in the.
hub of a bicycle in such a manner as to enable a rider in each revolution of the
pedal shaft to travel over an increased distance over that due to the circumference
of the driving wheel: such increased distance depending upon the relative
proportions of the toothed wheels used in the said speed gearing.
A tall rider may ride an ordinary bicycle with a driving wheel 60 inches
diameter. A shorter man may not be able to ride a bicycle with a driving wheel
more than 50 inches diameter; owing to his legs being so much shorter than the
taller rider. He is thus compelled in a given distance to make a greater number
of strokes with his legs than the taller rider with the larger machine and con-
sequently wasting a portion of his power.
With this improved speed gearing a rider may use a much smaller driving wheel
than he would need in an ordinary bicycle & thereby reduce the weight of the
machine, the number and length of the spokes and thus reduce the wind resistance
of such spokes For instance by applying this improved speed gearing a 40 inch
driving wheel could be geared up to any convenient size above 50 inches diameter
such increased size depending upon the relative proportions of the two toothed
wheels used in the said speed gearing. The speed gearing comprises two toothed
wheels placed within the hub: the larger of these wheels is securely attached to
the pedal or crank shaft and having teeth on its internal periphery The smaller
wheel is attached and forms part of the hub of the driving wheel of the bicycle
and having external teeth gearing into the internal teeth of the larger wheel,
TD 177

page_text: These toothed wheels may be made any convenient size or proportion to each
other as may be desired.
The hub and pedal shaft are shown in the accompanying drawings running in
ball bearings. Ball bearings however are not essential plain bearings may be used.
I prefer ball bearings.
In order that I may be fully understood I will more particularly describe my
invention with the aid of the accompanying drawings in which similar parts are
marked with like letters of reference.
Fig. 1. is a cross section of the speed gear. Fig. 2. is a vertical section through
the hub. Figs. 3, 4, 5, & 6 are elevations & sections of the two parts forming the
hub Figs. 7, and 8, are an end elevation and section of the internal toothed
wheel and pedal shaft.
The dotted lines in Fig. 1. represent the pitch circle of the teeth of internal
& external toothed wheels A. B.
E is the crank shaft on which B is securely fixed. Fig. 2. F. F. are the cranks
E the crank or pedal shaft H, H. the pedal shaft ball bearings P. P. P. P. the hub
ball bearings. A is a section of the external wheel which forms part of the hub C.
and is also shewn on Fig. 5. and by the dotted lines on Fig. 6. B. is a section of the
internal wheel which is fixed securely to the pedal shaft and which when the pedal
shaft is driven by the rider it communicates motion to the machine by turning the
wheel A.
The hub of a bicycle driving wheel D. C. is mounted loosely in the bearings P.
fitted to the ends of the front fork K.
The crank or pedal shaft E. passes through the hub a little out of the centre
and runs in the bearings H. H. which form part of the said hub bearings. Ordinary
cranks F. F. are fitted on to the ends of the crank shaft E. The hub D. C. is made
in two parts and securely joined in the middle and is enlarged between the flanges
to receive the two toothed wheels used in obtaining the increased speed.
It will thus be seen that by my arrangement of speed gear, a bicycle may be
geared up to any convenient size, by determining the proportions of the wheels A. B.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed I declare that what
I claim is
1st The arrangement of speed gear substantially as hereinbefore described and
shown.
2nd The combination of pedal shaft within hub bearing.
3rd The arrangement of external & internal toothed wheels.