Improved Driving Gear for Bicycles.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improved Driving Gear for Bicycles.
JOHN COWIE, Engineer, 115, Dumbarton Road, Glasgow, do hereby declare
the nature of this invention to be as follows:-
Double speed wheel (loose) with double clutch working on boss of chain main
speed wheel on right of bottom bracket spindle. (Loose) chain wheel with clutch
on left hand of bottom bracket spindle (loose) connected to chain wheel keyed on
counter spindle on bracket fixed on frame, connecting slow speed wheel right hand
bottom bracket spindle for decreasing speed connected with handle bar.
1007
JOHN COWIE, Engineer, 115, Dumbarton Road, Glasgow, 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:-
Above the ordinary bottom bracket spindle "D" I fix a counter spindle H support-
ed from bottom bracket by a bracket J on this spindle I fix two chain wheels G and K
and on the ordinary bottom bracket spindle D of bicycles I place two chain wheels
marked E and L on drawings also two clutches marked F and B the clutches
are held in position or moved backwards or forwards by crosshead or sliding
bar M. Clutch F having key fixed to it is a slack fit on spindle, the spindle having
a groove cut in it to suit key but allowing key to be slack in it, hence clutch F is
free to move backwards or forwards but not to turn round the spindle.
The tails on clutch B passes through boss C, of wheel A and when clutch B is
hard against wheel A (as showen on drawing) they enter wheel L in this position
wheel L would be in gear, as wheel E is fixed to bottom bracket spindle by means
of the clutch F hence wheel E would transmit its motion by means of chains, (not
showen on drawing 1 but on drawing 2) to wheel G which is keyed to counter
spindle H, and through wheel K (also keyed on counter spindle H) to wheel L but
as L is fixed to wheel A by means of clutch B therefore A will receive its motion
from L and be driven by it.
Sliding bar M is actuated by rod N which is led up directly underneath ordinary
steering handle (so that the gear may be altered without the rider dismounting)
when sliding bar "M" is moved over in direction of arrows on drawings, Sheet 1,
and 2, by handle P" being moved over to position shown dotted on drawing,
"

page_text: on
Sheet 3, then wheel "E" is released from clutch "F" and runs loose
spindle "D" at the same time wheel "L" is released from clutch "B, and
clutch "B" is now fixed to spindle "D" by means of collar "S" (which is keyed
on spindle "D"). Hence wheel Ⓐ" receives its motion through clutch "B,"
& collar "S.".
66
وو
By this means the speed may be reduced or increased by shifting the handle
(which is always at the rider's command to right or left.
.
The spring chain adjuster "R" is a spiral spring slipped on to the ordinary
tension bolt, between the nut and the crossbar so as to allow the tension bolt to
accommodate itself to the extra strain put upon it in ascending inclines, and so
reducing the friction. In descending inclines when the driving chain becomes
slack, the spring "R" will stretch the tension bolt out, and so tighten the chain,
thereby reducing the back lash.
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 :-
1st. Introducing double and single clutches "B" and "F" working on the
bosses of the ordinary chain wheels for the purpose of altering the gear.
2nd. Introducing the sliding bar "M" and handle P, and rod "N" to work
clutches "F" and "B."
3rd. Introducing spiral spring "R" between the nut and crossbar of the
ordinary tension bolt.
26th February 1898.