A New or Improved Driving Gear for Cycles.
Year: 1897

page_text: Date of Application, 13th Aug., 1897-Accepted, 13th Nov., 1897
A New or Improved Driving Gear for Cycles.
I, THOMAS GRANT, of 11 St. James' Street, Brighton, in the County of Sussex,
Dealer in Cycles, 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 driving gear for bicycles, tricycles and the like, and
consists of mechanism by means of which the motion of the bottom bracket spindle
is transmitted to the driving wheel without the use of a chain or chains.
Slight modifications of arrangement are possible without departing from the
principle of my invention.
In one form, I attach to the bottom bracket spindle, a suitable driving device,
such as the sheave of an eccentric encircled by a metal band or strap. To the
strap is attached a connecting rod or rods, which extend towards the hub of the rear
wheel of the machine. Their ends are attached to an internally toothed ring
disposed eccentrically to the centre of the rear wheel hub. Attached to the hub
is a toothed pinion, the teeth of which engage those of the internally toothed
ring. The rotation of the bottom bracket spindle is thus transmitted to the rear
wheel of the machine, and its progression results.
Other modifications of the gear are hereinafter described.
In order that my invention may be clearly understood and ascertained I append
drawings in which
Fig. 1 is an elevation of a bicycle shewing one form of the gear fitted thereto.
Fig. 2 is an enlarged elevation of the gear shewn in Fig. 1.
Fig. 3 is an elevation of a modification.
Referring to Figs. 1 and 2.
A is the bottom bracket spindle, to one end of which the pedal crank arm a
is attached. B is the eccentric sheave formed integrally with or firmly attached
to the spindle A. The eccentric sheave B is encircled by a strap or metal band b
to which is attached one end of an open frame C forming a connecting rod.
Between the periphery of the sheave B and the inner surface of the metal band b
balls or rollers may be introduced to lessen friction. To allow for the to and fro
notion of the connecting rod C, a stud c projects therefrom at or about the middle
of its length, and engages a slot in the frame of the machine, or a slot may be
formed in the connecting rod and engage a pin fastened to the frame.
The other end of the connecting rod C is attached to an annular or internally
toothed ring D, disposed eccentrically to the centre of the rear wheel hub e. The
teeth of the annular ring D engage the teeth d of a pinion E, which is formed
integrally with or firmly attached to the hub of the rear wheel. Thus when the
bottom bracket spindle A is rotated by the pedals a, the movement of the eccentric
sheave B is transmitted, by the connecting rod or rods C, to the annular toothed
ring D; the teeth of this latter gearing with those of the pinion E attached to.
the rear wheel hub, causes the hub to rotate and the machine to progress.
Referring to Fig. 3.

page_text: This figure shews a modified form of driving device. It consists of the employ-
ment of a pedal crank arm or arms F' of modified form, which are caused to
oscillate by the feet of the rider. The pedal crank arms F, only one of which are
shewn, are fulcrummed at f, and one end of each are preferably slotted to receive
a pin f projecting from one end of the connecting rod or rods C. The other end
of the latter is connected to the annular toothed ring D, the teeth of which engage
those of the pinion E as above described.
Thus when the pedal crank arm or arms F are caused to oscillate by the feet of
the rider the motion imparted to the connecting rod or rods C will cause the
rotation of the annular toothed ring D, around the pinion E, causing the latter to
rotate. Or the ring D may be of any contour desired.
As a modification the backward end or ends of the connecting rod or rods C
may be toothed to engage the pinion E direct. Suitable devices would be
arranged to cause the teeth to disengage during the backward stroke of the con-
necting rod or rods. The pedals may be either caused to rotate or oscillate.
Figs. 4 and 5 shew a modification of my driving gear. It consists of a pedal
crank arm or arms F which are caused to oscillate by the feet of the rider as in
Fig. 3. These arms F, one of which only is shewn in the drawings, are fulcrumed
at f, and one end is preferably slotted to receive a pin f projecting from one end
of the connecting rod or toothed rack C; the other end of the connecting rod C
consists of a toothed rack j which engages the teeth of the pinion d which
runs loosely on the spindle E of the driving wheel. On the inner circle of this
pinion dare formed slots e, in these slots are placed wedges, balls or rollers g.
The action of this mechanism is as follows:-
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The crank arms F being made to oscillate by the feet of the rider the pin f¹ and
connecting rod or toothed rack C are drawn forward and the toothed rack j
being in gear with pinion causes it to rotate. The wedges, balls or rollers g
are driven to the narrow end of the slots e thus locking the pinion d to the hub D
and spindle E and so causes the driving wheel to rotate. The connecting rod or
rack C in its backward stroke causes the pinion d to reverse its motion, but
the wedges, balls or rollers y being driven to the widest part of the slots e, the
pinion turns loosely on the hub D and spindle E until the forward stroke again
causes the wedges, balls or rollers g to lock the pinion d to the spindle E. Instead
of the balls and slots e any ordinary form of ratchet and pawl device may be
employed.
When the pedals are required to rotate I employ an eccentric on the bottom
bracket as in Fig. 1.
In some cases I may if necessary affix to the ring D an eccentric sheave attached
to the hub encircled by the usual strap, thus forming a suitable guide for the
movement of the ring D.
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:-
-
4
1. Mechanism for driving cycles and like vehicles consisting essentially of an
eccentric sheave, or other suitable device, attached to the bottom bracket spindle, 4
the rotation of both being caused by the feet of the rider rotating the pedal crank
arms, said motion being transmitted to the hub of the rear wheel by a centrally
pivoted or slotted connecting rod or rods attached to an annular or internally
toothed ring disposed eccentrically to the rear wheel hub, on which is mounted a
toothed pinion, the teeth of which engage those of the annular ring, substantially 5
as described and shewn with reference to Figs. 1 and 2.
2. In mechanism for driving cycles and like vehicles, the combination of the
centrally pivoted or slotted connecting rod or rods C, the toothed annular ring D
toothed minion E, and a suitable driving device attached to the bottom bracket

page_text: spindle, and operated by the feet of the rider, substantially as described and
shewn.
3. Mechanism for driving cycles and like vehicles consisting essentially of
the pedal crank arm F, fulcrummed at f, the connecting rod or rods C attached
at one end to the pedal crank arms, and at the other end to the toothed annular
ring D and the toothed pinion E, substantially as described and shewn with
reference to Fig. 3.
4. The improved mechanism for driving cycles and like vehicles, substantially as
described and shewn with reference to Figs. 1 and 2.
5. The improved mechanism for driving cycles and like vehicles, substantially
as described and shown with reference to Fig. 3.
Dated this 13th day of August 1897.
WILLIAM J. MUNDEN,
75 Chancery Lane, W.C., Agent for the Applicant.