Improvements in Crank Driving Mechanism for Velocipedes, Motor Cars, and other Machines.
Year: 1897

page_text: Date of Application, 6th Aug., 1897
Complete Specification Left, 6th May, 1898-Accepted, 9th July, 1898
IIVOVIDIONAL DEVITICATION.
Improvements in Crank Driving Mechanism for Velocipedes, Motor
Cars, and other Machines.
I, JOHN MOUNTGOMERY COLLINS, of 45, Bartholomew Street, Bridgeton, Glasgow,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to crank driving mechanism capable of being adapted
for driving velocipedes, motor cars, and other locomotive or stationary machines.
In carrying out my invention, say for a bicycle, I cast in one with or secure
to the bottom bracket a circular frame or support having three or other number
of friction rollers projecting laterally from its periphery. These rollers are grooved
or otherwise made so as to carry between them a sprocket driving wheel geared
by means of a chain to the driving pinion of the driving wheel of the bicycle.
The sprocket wheel aforesaid is, by preference, made with four spokes each of
which is slotted.
The bottom bracket is excentric of the sprocket wheel and is provided with the
usual cones, cups, and balls.
Two cranks are used and these cranks are both at the one side the spindle of
one of the cranks is hollow and works in the bottom bracket whilst the spindle
of the other crank is passed through the hollow spindle of the first crank. The
crank with the hollow spindle is provided with a crank pin having a friction
roller which works in one of the slots of the sprocket wheel aforesaid and also
having secured to it a pedal or pedal crank. The crank with the solid spindle
has a crank pin on it with a friction roller which works likewise in one of the
slots of the sprocket wheel. The solid spindle is carried right through the bottom
bracket and is provided with a pedal and pedal crank at its outer end.
The sprocket or other driving wheel may be carried in other suitable and well
known manner.
If desired the driving wheel may be made in the form of a disc with slots
therein.
Only two slots are required one for each crank but I prefer to have four slots
so that when one pair of slots is worn the crank mechanism may be changed
to the other pair.
The driving wheel may be made without sprocket teeth and in this case it is
made to drive by means of friction, belt or rope gearing, lever connections, or in
other well known manner, any shaft or body required to be rotated.
The cranks may be driven by power for certain classes of machinery.
Dated this 5th day of August 1897.

page_text: Improvements in Crank Driving Mechanism for Velocipedes, Motor
Cars, and other Machines:
I, JOHN MOUNTGOMERY COLLINS, of 45, Bartholomew Street, Bridgeton, Glasgow,
Scotland, Engineer, 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 crank driving mechanism capable of being adapted
for driving velocipedes, motor cars, and other locomotive or stationary machines
for which it may be suitable.
And in order that my said invention may be properly understood I have hero-
unto appended two explanatory sheets of drawings, which show the driving
mechanism, by way of illustration or example, applied to a bicycle.
Referring to the drawings:-
Fig. 1 is a side elevation of the mechanism.
Fig. 2 is a cross section on the line - Fig. 1.
Fig. 3 is a front view and Fig. 4 a plan view of the driving cranks drawn to
an enlarged scale.
a is the bottom bracket of the bicycle, b is the front inclined stay, c is the
diagonal tube, d is one of the back stays, e is one pedal crank and f the other
pedal crank.
The bottom bracket a has made in one with or fitted to it an eccentric disc or
support which is made with a flange h¹ at one side and has a flanged ring h
screwed into it at the other side. Running on balls i in the trough formed between
the two flanges is a sprocket wheel of which are the sprocket teeth. This
sprocket wheel j has made one with or secured to it a cross bark which, as clearly
shown at Fig. 2, is held by its bent ends k¹, k, at a slight distance away from
the surface of the wheel so as to leave a free space for the driving cranks to work
in. This bar which extends right across the centre of the wheel, as shown, has
two longitudinal slots l, m, in it. Working in the slot m is a roller n which is
secured upon a pin o made one with or fitted in the end of the driving crank I of
the hollow spindle or sleeve 2 which latter runs in ball bearings in the bottom
bracket a. Working in the slot 7 is a roller r carried on the pins of the driving
crank which is made one with the solid axle or spindle u. If so desired this
axle u may be carried in ball bearings fitted within the hollow spindle or sleeve p
which latter as well as the bottom bracket, would, in such a case, be made larger.
Figs. 3 and 4 show the arrangement of the spindles p, u, and the driving cranks
very clearly.
As shown at Figs. 1 and 3 the crank 7 may be tapered longitudinally and be
also cut away at an angle at the end t¹. The pedal crank e is fitted on the crank
pin o and the pedal crank f is fitted on the end of the shaft u. vare pedals.
to are nuts. y are balls. z are washers.
As will be seen the distance from the centre of the axle u to the centre of the
pins is exactly equal to the distance from the centre of the axle to the centre of
the pin o
As will be seen from Fig. 1 the centre of the sprocket wheel does not coincide
with the centre of the axle u or the centre of the bottom bracket owing to the
fact that the disc h is arranged eccentrically of said bracket.
With the construction of mechanism herein before described there is besides
other advantages a gain in leverage at each forward stroke of the pedal cranks.
One eccentric only is required.

page_text: The sprocket wheel drives, by means of a chain, a pinion on the hub of the
back wheel of the bicycle as usual.
The invention can be adapted for driving chainless gears as well as chain gears.
The details of construction of the mechanism can be altered or modified with-
out departing from the invention. I am aware that eccentric gears of various
types have been previously used.
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
consider novel and desire to claim is:-
1. Crank driving mechanism comprising, in combination, a driving wheel run-
ning upon an eccentric or its equivalent, a cross bar, made with longitudinal slots
therein, on the driving wheel, a hollow spindle or sleeve made with a crank and
having a pin and roller or equivalent which works in one of the slots of the cross
bar, and a crank axle passed through the hollow spindle or sleeve and having a
pin and roller or equivalent which works in the other slot of the cross bar, all
substantially as hereinbefore set forth.
2. The construction, or general arrangement and combination of parts, of the
crank driving mechanism, substantially as herein before described and shown on
the drawings annexed.
-
1000
Dated this on day or may
H. D. FITZPATRICK,
100, Wellington Street, Glasgow, Agent.