Improvements relating to Cycle and other Driving Gear.
Year: 1897

page_text: Date of Application, 28th Apr., 1897-Accepted, 29th May, 1897
DI MULTIUATION.
Improvements relating to Cycle and other Driving Gear.
I, LUCIEN STEPHEN CRANDALL, of 62 Moor Street, in the City of Birmingham,
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 consists of improvements relating to cycle and other driving gear,
my object being to provide simple and efficient means for the transmission of power
and to so arrange the same that the ratio beween the speeds of the driving and driven
parts can be very readily and conveniently varied.
In order that my invention may be the more readily understood, I append hereunto
three sheets of explanatory drawings to be hereinafter referred to..
-
:
Figure 1 on Sheet 1 is a side elevation of a bicycle fitted with one form of my
improved driving gear.
On Sheets 2 and 3 the combination and arrangement of parts forming my improved
driving mechanism is illustrated to a larger scale.
Figure 2 is a side elevation and Figure 3 an end elevation representing one
construction of my gear.
Figures 4 and 4 are sectional views illustrating one method of connection between
the gear and the rear wheel of a cycle.
Figure 5 is a side elevation representing the gear adjusted to such a position as to
give the minimum ratio between the speeds of the driving and driven parts.
Figure 6 is a side elevation and Figure 7 a part sectional end elevation
representing a modified form of connection between the gear and the rear wheel of
a cycle.
Figure 8 is a side elevation and Figure 9 an end elevation representing another
construction of my driving gear.
Figure 10 is a side elevation and Figure 11 an end elevation representing a further
modification in the construction of my improved gear, and Figure 12 an end view
showing the combination of anti-friction balls with the eccentric.
Figure 13 illustrates the gear in position for minimum speed.
The same reference letters in the different views indicate the same parts.
In the application of my invention in one manner to a cycle such as illustrated at
Figure 1, I secure upon the crank shaft, indicated by the letter A in the detail views
in place of the ordinary chain wheel employed in chain driving gear, an eccentric
sheave B and on the end of the bracket adjacent thereto, I mount an adjusting worm
wheel or block such as C. The worm D upon the tubular or other spindle D¹ gears
into the worm block C and adjustment can thus be effected by turning the hand
wheel D² on the upper end of the spindle D, such hand wheel being arranged in a
convenient position for operation by the rider without dismounting and whilst the
machine is in motion.
The eccentric sheave B imparts a reciprocating or oscillating motion to the lever E
pivotted upon a link F which is connected to the projecting arm (from the worm
block C; one end of the lever E embraces the eccentric sheave B, whilst the opposite
end is jointed to the pitman or connecting rod G. Thus on the revolution of the
crank shaft a reciprocating motion is imparted to the pitman or connecting rod G.
A slotted or shackle-like end G¹ is provided at the rear part of the pitman or
connecting rod G to receive the operating clutches H H. Each of the clutches H H¹
are mounted loosely upon the projection J from the rear wheel hub and are prevented

page_text: from lateral displacement from the slotted or shackle-like end G', by the fixed flange J
on the one side and the movable flange J2 on the opposite side. The flange J is
removed from the views given at Figures 2 and 5. The clutches each consist of a
ring having an external flange at each side and a plain internal surface which rides
upon the projecting boss J. Grooves or recesses as J³ are formed in the boss J for
the reception of rollers as illustrated at Figures 2 and 5.
Within the slot or shackle end G' of the pitman or rod G, I secure a pair of wire
or other flexible cords as K K', one at the upper and the other at the lower side. One
end of the cord K' (Figures 2, 4 and 5) is secured in any convenient manner to the
shackle at a and the opposite end is then passed completely around the clutch ring H!
(Figures 4 and 4*), and after the cord is pulled tight throughout its length such end
is secured to the shackle at b. In the same manner the lower cord K is secured to
the shackle and passed round the clutch ring H; but whereas the cord K' is led around
the clutch ring H' from its upper side, the cord K is led around the clutch ring H
from the under side and thus as the pitman or rod G is reciprocated, the clutch rings
will be revolved in opposite directions.
On the movement of the pitman or rod G in the direction indicated by the arrow 1
(Figure 2) the clutch ring H' will be revolved in the direction indicated by the arrow 2
and will cause its rollers to be retained against the shouldered ends of the grooves
or recesses J³, and will thus impart no motion to the rear wheel. But at the same
time the clutch ring H will be revolved in the direction indicated by the arrow 3, and its
rollers will be moved away from the shouldered ends of the grooves or recesses and
towards the narrow ends, and thus by becoming wedged between the clutch ring and
the projecting boss J will lock the two parts and cause them to revolve together. On
the reverse movement of the pitman or rod G the clutch ring H' and the rear wheel
will be revolved together in the direction of the arrow 3 whilst the clutch ring H will
revolve idly in the opposite direction. Thus by the continuous reciprocation of the
pitman the driving wheel will be constantly revolved in the one required direction.
Each clutch ring is provided with its own set of rollers, the ring L being interposed
between them. The interior surface of the ring L is formed to suit the section of the
projecting boss J.
As illustrated at Figures 2 and 3 the lever E is set in the position to give the
maximum ratio between the speeds of the crank shaft and the rear or driving wheel
of the bicycle for the particular pivot eye which is mounted upon the pintle or pivot
pin of the link F. The position illustrated is suitable for pedalling the machine over
a flat road or when only a moderate tractive force is required and the rider wishes
the distance travelled by the machine to be the maximum multiple of the movement
of the pedals.
As illustrated at Figure 5 the lever E is set in the position to give the minimum
ratio between the speeds of the crank shaft and the rear or driving wheel, the length
of the reciprocating movement of the pitman G being now limited to twice the throw
of the eccentric B. Such position is suitable for bill climbing or when a considerable
tractive force is required upon the driving wheel.
The position of the lever E can be readily adjusted to any point between the speed
position shown at Figure 2 and the hill climbing position shown at Figure 5, by the
operation of the hand wheel D2, (Figure 1), and, as herein before described, such
operation can be effected by the rider without dismounting, and whilst the machine
is in motion.
The lever E can be pivotted upon the link F at any of the pivot eyes as e to suit
the rider. By pivotting at the eye nearest to the crank shaft A, the maximum
possible ratio between the speeds of the crank and the driving wheel will be obtained.
Instead of the cord connection between the pitman and the clutches as herein-
before described, I sometimes form teeth upon the exterior surfaces of the clutch
rings to engage with rack teeth formed in the shackle end of the pitman, the rack
teeth being at the upper and lower sides respectively as illustrated at Figures 6 and 7,
in order to cause the clutch rings to revolve in opposite directions.
In the construction shown at Figures 8 and 9 the lever E' is pivotted at its lower

page_text: extremity and has its connection with the eccentric B between its two ends or
extremities. The lever in this case is therefore a lever of the "third kind" having
the power or operating force applied between the fulcrum and the load or resistance
to be overcome, whereas the lever in Figures 2 and 3 is of the "first kind" having
the fulcrum between the operating force and the resistance.
In the modification illustrated by Figures 10 to 13 inclusive on Sheet 3, the lever E²
is provided with a central aperture for the reception of the eccentric which is preferably
made in two parts and has anti-friction balls carried in a retaining groove around its
periphery, as illustrated in the large sectional view of a portion of the eccentric at
Figure 12. The lower end of the lever E2 is pivotted directly upon the projecting
arm C' from the worm block C. With such a form of my improved gearing, the
minimum horizontal or effective movement of the pitman G on the revolution of the
eccentric is limited to the distance indicated at M Figure 13.
I do not limit myself to the particular construction and combination of parts as
hereinbefore described, but make such modifications as may be necessary to the most
convenient and effective application of my invention to cycles, motor cars, and other
services.
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 cycle and other driving gear means substantially as described whereby the
ratio between the speeds of the driving and driven parts can be very readily varied.
2. In cycle and other driving gear, the use of an oscillatory lever upon or in
connection with the crank shaft having means for the adjustment of its effective
leverage substantially as and for the purposes described and as illustrated.
3. In cycle and other driving gear, the combination comprising an eccentric mounted
upon or secured to the crank or driving shaft and arranged to oscillate a variable
lever in attachment with a pitman or rod connecting with the rear wheel or other part,
substantially as and for the purposes described and as illustrated.
4. In cycle and other driving gear, the construction and arrangement of parts
whereby the continuons reciprocation of a pitman or connecting rod having a variable
length of stroke, imparts a rotary motion in the one direction to a driving wheel or
other part, substantially as described and as illustrated.
5. In cycle and other driving gear, the combination with a reciprocating pitman or
rod of a pair of clutches arranged to revolve in opposite directions and to alternately
seize and release the driving wheel hub or other part in such a manner that the
movement of the pitman in each direction shall impart a rotary motion in one
direction to such hub or other part, substantially as described and as illustrated.
6. The improved adjustable driving gear for cycles, motor cars, and other services,
substantially as described.
Dated is on day of
MARKS & CLERK,
18 Southampton Buildings, London, W.C., and
13 Temple Street, Birmingham, Agents for the Applicant.