Improvements in a Certain Form of Driving Mechanism of Safety, Bicycles.
Year: 1896

page_text: Date of Application, 16th July, 1896-Accepted, 22nd Aug., 1896
COMPLETE SPECIFICATION.
Improvements in a Certain Form of Driving Mechanism of Safety,
Bicycles.
I WALTER WILLIAM CURTIES of 71 Cathedral Square Christchurch in the Pro-
vincial District of Canterbury in the Colony of New Zealand Cycle 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 the driving mechanism for safety bicycles for which I
together with Nelson Laveux Nelson Dyhrberg and Albert Crum; applied for Letters
Patent on the 17th day of March 1896 such application being numbered 5891.
I have found the driving mechanism therein described imperfect as there is no
means of adjusting the relative proportions of the quadrant and pedal levers and
motion of the machine cannot be retarded by what is known as "back pedalling."
My improvements consist in substituting projecting arms for the quadrants
described in the prior specification referred to, the length of such arms being
adjustable either automatically or otherwise to the work they have to perform.
The other of my improvements consists in fixing upon each side of the hub of the
driving wheel a friction sheave which is surrounded by an outer sheave divided into
seginents. The cord which passes over a guide pulley from one side of the machine
to the other to connect the driving gear is coiled around these segments and it is
arranged that when the pedal levers are simultaneously depressed sufficient strain is
produced upon the cord to cause the segments to move inwardly; come in contact
with the peripheries of the friction sheaves and thus retard motion of the machine. :
Referring to the accompanying drawings :-
Figs. 1 and 2 are respectively a side and end elevation of a pedal lever showing the
projecting arms.
Fig. 3 is a plan of one end thereof.
Fig. 4 a section showing an arm adjustable by a telescopic joint and
.
Fig. 5 a vertical central section of an arm the length of which is automatically
adjustable.
1
Fig. 6 is a side elevation one half of which is in section; showing the hub of the
driving wheel with the friction sheaves and driving clutches.
Fig. 7 is an end thereof and
Fig. 8 a section on line 8-8 Fig. 6.
Fig. 9 shows a segment of the friction sheave removed.
Fig. 10 is a side elevation of a bicycle fitted with my invention.
Similar letters of reference indicate the saine parts in all the figures.
:
Referring first to Figs. 1 to 5 the tubular pedal lever (a) is formed with the gland
or clip (6) by means of which it is fixed upon the rocking spindle (c) journalled in the
bottom bracket of the frame of the cycle. One end of the driving cord (d) is fixed
to jointed wire rods (d') which are pivotally secured to an eye (e) at that end of the
lever to which is attached the pedal the other end of the cord is carried to the
drum (Fig. 6 around which it is coiled and the end secured to it by a clip or other
convenient means.
When the pedal levers are vibrated by the rider the projecting arms (g) (h) severally
come in contact with the wire rods (d') which are jointed at the place of contact and
it will be evident that the pull exerted thereon depends upon the relative lengths of
the pedal lever and proiecting arm.

page_text: The length of the arm (h) may be adjusted by sliding the end thereof telescopically
within the tubular base () wherein it is secured by the clamping gland (h2).
To render the arm automatically adjustable so that its length will vary according
to the pressure of the rider's foot upon the pedal, a cylinder (i) is employed upon
the pedal lever within which operates the arm (5) provided with a piston (¹). A
spring (k) bears against the underside of the piston and normally causes the arm to
project its full extent but when the cycle is propelled uphill or when from other
causes the strain upon the driving cord increases then the pressure upon the arm
overcomes the resistance of the spring (k) and it is forced a certain distance into the
cylinder.
Oil is placed within the cylinder and the piston has a valve (!) or by-pass which
"regulates the passage of liquid from one side of the piston to the other and prevents
too rapid alteration in the length of the arm.
The pressure of the spring (k) upon the piston may be adjusted by the set screw (m)
passing through the cylinder cover (n).
The ends of the arms are made of "T" pieces fitted with wood, rubber, or other
¡material to form a bed for the driving cord the metal being cut away at the place
where the cord comes in contact.
Referring now to Figures 7, 8, and 9.the hub (o) of the driving wheel has formed
integral with it the friction sheave (p) an outer friction sheave (9) divided into
separate segments surrounds the periphery of the sheave (p) the segments being
guided by projecting lugs () upon the side of the clutch drum (f) fitting into
recesses (p) formed in the segments. The clutch drum (s) surrounds the ratchet
wheel (t) which is similar to and operates in the manner fully described and illustrated
in the prior specification referred to.
The nut or plate (u) screwed upon a projection (u¹) formed upon the side of the
clutch drum (s) serves to maintain the segments in position.
Springs (v) are placed in recesses (u 2) formed on the inner side of each of the
segments and bearing against the projection (ul) normally keep the outer and inner
peripheries of the friction sheaves (1) and (q) respectively out of contact.
Separate driving cords (d) one from each of the pedal levers are severally coiled
round and secured to the clutch drums (f) upon either side of the machine a cord (w)
which is employed to raise one pedal lever when the other is depressed is coiled round
the segments of the friction sheave (q) the end being secured to one of them, it is
then carried over a guide pulley (w) journalled upon the frame of the cycle (as
described in the prior specification referred to) and coiled round and the end secured
to the segments of the friction sheave upon the other side of the machine.
In operation when the pedal levers are depressed alternately the 'strain upon the
cord (w) is not sufficient to over-come the resistance of the springs (v) but when the
pedal levers are depressed simultaneously then strain is put upon the cord (w) which
causes the segments (g) to move inwardly and their inner periphery to come into
contact with the outer periphery of the sheave (p) and 'so retard motion of the
machine.
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 safety bicycles driving mechanism the combination with a pedal lever of
projecting arms: the end of which when' the pedal lever is'vibrated engage jointed wire
rods connecting one end of a driving cord to the pedal lever the other end of such
cord being coiled around a drum operating the driving wheel substantially as and for
the purposes set forth and illustrated.
2. The combination with the pedal lever (a) of an arm (/) telescopically adjustable
within a tubular base: (1) fixed upon the pedal lever a clamping gland (2) securing
¡the arm in a desired position substantially as and for the purposes herein described
and illustrated.
3. The automatically adjusting arm (9) consisting of the combination with the

page_text: pedal lever (a) of a cylinder connected thereto an arm provided with a piston
reciprocating within such cylinder the length of the arm being regulated by the
pressure of the driving cord (or rods connected thereto) when in contact with the end
of the arm tending to force it into the cylinder against the pressure of a spring
operating in the opposite direction substantially as and for the purposes herein described
and illustrated.
4. The arrangement for retarding motion of the cycle when the pedal levers are.
simultaneously depressed consisting of the combination with the hub of the driving
wheel of friction sheaves upon either end thereof the peripheries of such sheaves.
being surrounded by outer sheaves divided into segments a cord coiled around the
segments of one sheave being continued across the machine and coiled around the
segments of the other. Strain upon the connecting cord due to the simultaneous
depression of the pedal levers overcoming the resistance of springs operating the
segments in the opposite direction and causing them to move inwardly and their inner
peripheries to come into contact with the outer peripheries of the sheaves upon the
hub of the wheel substantially as herein described and illustrated.
5. In combination with the friction sheaves (p) upon the hub of the driving wheel
the segmental friction sheaves (q) surrounding the same guided by projecting lugs.
formed upon the side of clutch drums (f) which take into recesses formed in the sides
of the segments substantially as and for the purposes herein specified and illustrated.
6. In combination the friction sheaves (p) the surrounding segmental sheaves (g).
and the springs (v) in the recesses (u 2) formed in the segments substantially as-
specified and illustrated.
Dated this 16th dore of T..1.. 1000
J. E. EVANS-JACKSON & Co.,
Agents for the Applicant.