Improvements in or relating to Driving Mechanism, especially suitable for Cycles.
Year: 1897

page_text: Date of Application, 15th Dec.. 1897
Complete Specification Left, 18th Aug., 1893-Accepted, 12th Nov., 1898
PROVISIONAL SPECIFICATION.
Improvements in or relating to Driving Mechanism, especially
suitable for Cycles.
I, GEORGE WYATT, of 21, Benedict Road, Brixton, in the County of Surrey,
Architect and Surveyor, do hereby declare the nature of this invention to be as
follows:-
This invention relates to driving mechanism particularly suitable for cycles,
though it may be employed for other purposes, say for example for motor vehicles.
I will now describe it as applied to a bicycle of the ordinary safety construction.
In carrying out the invention I place centrally upon the crank axle a toothed
driving wheel, and divide or suitably arrange or construct the crank bracket or
other portions of the frame-work to accommodate this. The wheel has driving teeth
upon both faces, and when it is desired to use this gearing in order to obtain
changes of speed, I employ any required number of rings of teeth upon each side.
The rings of teeth upon the two faces may be the same number or different numbers
as preferred.
The teeth of the wheel may be of the ordinary construction, but I prefer to make
them as pins either with or without sleeves or rotating surfaces.
Upon or in the frame of the bicycle are carried preferably in ball bearings two
hollow or other shafts, extending substantially from the previously mentioned
toothed wheel to corresponding toothed wheels secured upon the hub or axle of the
road driving wheel of the cycle.
Wheels are carried at or about each end of the axle to engage with the various
wheels, and I prefer to make the axle telescopic or otherwise to so arrange that
the wheels near the crank bracket may be caused to engage with the various sets
of toothed rings upon the crank or crown wheel, Any suitable form of mechanism
may be employed for changing the positions of these wheels.
For preference, as causing the least friction, I prefer to make the engaging
wheels respectively pin or roller wheels but I may vary this construction if desired.
By this means I obtain central instead of one-sided driving, and the road wheel
being driven from each side the tendency to side slip is reduced.
Dated this 15th day of December 1897.
BOULT & WADE,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvement in or relating to Driving Mechanism, especially
suitable for Cycles.
I, GEORGE WYATT, of 21, Benedict Road, Brixton, in the County of Surrey,
Architect and Surveyor, do hereby declare the nature of this invention and in what
[Price 8d.]

page_text: manner the same is to be performed, to be particularly described and ascertained
in and by the following statement:-
The invention relates to driving mechanism particularly suitable to cycles
though it can be employed for other purposes such as motor vehicles.
In carrying out the invention the driving wheel or disc is placed centrally upon
the crank axle, the crank bracket or any other portion of the frame work being
divided or suitably constructed to suit this.
The driving wheel or disc D has three rings as shown on the drawings Figs. 1,
2 & 4 (or it can have more or less in number) with pins projecting on both sides
of each ring, the small ring giving a low gear and the larger rings higher gears.
The hub on each side of the rear or road wheel is provided with a single ring or
disc L having similar pins to the driving wheel, and between the two wheels or
discs an axle or shaft is placed revolving upon suitable ball bearings on each side
of the road or rear wheel, at one end of these axles or shafts is fixed a star shaped
fitted with rollers which engage the pins on the discs of the hub of the rear or road
wheel, while the other end of each of these axles or shafts is provided with a similar
star shaped wheel with rollers, and having a clutch attached thereto seated on ball
bearings. This wheel is arranged with a key way so as to revolve with, and to
slide backwards and forwards along the axle or shaft, to engage at will the respec-
tive rings of pins on the central crank wheel or disc. By this means the gears can
be varied and central driving is absolutely obtained.
A suitable method of carrying out the invention when applied to a bicycle of the
ordinary safety construction is shown in the accompanying drawings.
Fig. 1 is a side view and
Fig. 2 a plan part in section, part in elevation of so much of a bicycle as is
necessary to show the construction of the invention.
Fig. 3 is a detail of the adjustable gear shown in Figs. 1 & 2.
Fig. 4 is a front view of the bifurcated crank bracket and back bone tube.
Fig. 5 is a side view of an alternative arrangement for shifting the movable gear
wheel for varying the speed.
Fig. 6 is a drawing of the pins to the driving wheel D.
Fig. 7 is an enlarged drawing of the locking rings of the driving wheel D.
Fig. 8 enlarged drawings of the sliding star or pinion wheel 1.
Fig. 9 enlarged drawing of the back star gear wheel H lug F4 and extended and
recessed hub.
Fig. 10 enlarged drawing of the fittings F¹ of bottom brackets A, A¹ and bear-
ings F, G, G³.
Like letters refer to similar parts in all the drawings.
The crank bracket is formed in two distinct parts A, A each of which is con-
nected to a branch of the bifurcated back-bone tube B. and seat tube C as shown
in Figs. 2 & 4, thus to leave a space between them for the driving wheel D, which is
carried by a screwed boss on the centre of the crank spindle E to which it may be
secured in any convenient manner.
The driving wheel or disc D may be formed in various ways, preferably as
shown on Figs. 1, 2 & 4 with three grooved or recessed rings L' L2 L³. Threaded
holes are formed through the bottom of the recesses to receive pins L Fig. 6.
Each pin has a square nut in the centre with a thread cut immediately under same
on one side to screw into threaded holes in the recesses of the rings L1 L2 L³ the
pins L Fig. 6 have plain bodies with rounded or otherwise shaped ends of equal
lengths on the side of the nut, and thread respectively the plain bodies of the pins
projecting equal distances from each face of the rings L L L of the driving
wheel D. Although preferably pins with rounded bodies are employed as shown
in the drawings the shape of these pins may be varied. Thin flat rings L5 Fig. 7
(preferably made in two or more pieces) are fitted into the recesses of the
rings L L L and fastened by countersunk screws.
These flat rings L5 are perforated with square holes corresponding with the

page_text: square nuts of the rins L' and lock the latter in position, an arrangement which
allows of a pin being readily replaced.
The driving wheel D is screwed on a threaded boss E Figs. 2 & 10 placed
centrally on the crank axle E, and is kept in one position by a flange or back
nut EE on each side, one with a left and one with a right handed thread,
screwing on threaded bosses on the crank axle E of less diameter than the boss for
receiving the driving wheel D. These flanges or back nuts are recessed on their
internal faces to allow of the adjustment of the driving wheel D. This manner
of securing the driving wheel D is preferable as shown, but it may be secured
in any other convenient manner.
The bearing portion of the crank axle bracket will have ball bearings.
Each portion A A¹ of the crank bracket is connected to a separate tube F, these
tubes form the bottom stays and they are identical in construction, and arrange-
ment, the description herein given of one being therefore understood to apply to
both. The tube F is screwed into the socket of the crank bracket or otherwise
secured thereto. At the junction of the tube F with the crank bracket a fitting Fi
is provided with a female thread to screw into position on to the socket of the crank
bracket, having a curved groove which forms one wall of the race of a ball bear-
ing F. The rear end of the tube F is threaded with a female screw F³ into which
is screwed one end of the arm or lug F, this arm or lug F forming the connection
with the pin or axle of the back or road wheel, as shown at F5. Upon the arm
or lug F is a raised threaded collar F8 to receive the cone F6 with a curved groove
to form one wall of the race of the ball bearing F7. The cone F6 screws along the
collar F8 for adjusting the bearings.
Enclosing the tube F is a tube G, furnished at its front end with a fitting or
fixed collar G3 screw threaded to receive the cone of the ball race, the cone G¹ is
curved and grooved and forms the other wall of the race of the ball bearing F².
This cone is female-threaded to screw along the fixed collar Gs for adjusting the
bearings. At the rear end of the tube G is fixed by screwing or otherwise, the
star gear wheel H, formed with a recess to receive the hardened curved grooved
bearing which constitutes the other wall of the ball race F7. The tube G and its
star gear wheel H are thus capable of free rotatory movement on the tube F.
On the front end of the tube G is a raised strip of metal G2, which forms a key
engaging with the keyway I' (Figs. 3 and 8) of the star gear wheel I which thus
rotates along with the tube G. This is capable of longitudinal movement on the
tube G, so that this star gear wheel I can be placed at will opposite and so to
engage any one of the rows of pins of the driving wheel D.
The star wheels I, H, which engage the driving wheel D and the pins on the road
wheel hub respectively, are preferably shaped as shown Fig. 3 and 8 9, having
steel rollers M carried upon pins M¹ turned with shoulders at each end to fit
into holes in the flanges of the wheels. One flange or plate M² is arranged so as to
be removable, being secured by countersunk screws M³ to enable any broken or
damaged roller being easily removed and replaced. One end of the
body of the wheel I is prolonged M, and threaded to take the threaded cone I³
forming a race to receive a ring clutch I³. The sides of the cone I2, and both the
sides of the ring clutch I³ are provided with corresponding curved grooves forming
the recesses for ball bearings, and the body of the star wheel I is recessed on one
side to receive the hardened ball race M5 with grooves corresponding with those in
ring clutch I³. The ring clutch 13 forms a clutch with ball bearings to reduce
friction, having a lug I' with which is connected a horizontal rod 15, one end being
threaded having nuts I° 17, so as to admit of adjustment, the rod 15 is carried in
guides B C fixed on the back-bone and seat tubes respectively, and has its other
end pivotted in the slotted end of a lever IB.
The shifting ring clutch 13 of the star gear wheel I may be connected to and
actuated by cords, wires or any other reciprocating mechanism in place of the
device described herein.
As above stated the construction and arrangement of the mechanism of the

page_text: bottom tubes, are identical, and the lever 18 of each side of the machine is fixed
on the corresponding end of a rotating cress rod I carried by lugs I10 I1 on the
bifurcated ends of the backbone tube. To the centre of this cross rod is fixed a
short lever I¹ pivotted to the connecting rod B2 working in guides B³ placed con-
veniently on the back-bone tube. The connecting rod B2 is carried to any
convenient portion of the frame so as to be readily manipulated by the rider when
in the saddle, and while the machine is in motion. This rod B2 is fitted with a
handle having a press spring catch locking into notches cut in a plate fixed to the
frame, so fixing the gear wheel I into position so as to engage with either of the
rings of pins on the driving wheel D.
The range of movement of the crank and lever 18 I2 is shown in dotted lines
in Fig. 1, and is such as to enable each star gear wheel I to be placed at will
opposite any one of the circle of pins on its own side of the driving wheel D.
An alternative arrangement is shown in Fig. 5 in which each slotted lever 18
is pivotted to a lug C on the branch of the bifurcated seat tube C connected to its
own side of the crank bracket. Each lever 18 is pivotted on a cross rod 14 fixed on
the end of the connecting rod B2, the end of the lever 18 is slotted and connected
with lug I. Each star gear wheel H engages with a pin wheel or disc L, L, which
is fitted with ring of single pins having square nuts and threaded ends and locked
with plates as described, to driving wheel which may be fixed in any convenient
manner on both sides of the web of the recessed hub. A desirable form of construc-
tion is shown in Figs. 12 & 9, in which the hub K of the road wheel is formed
with a central web K¹, having flanges K2 K3 on to which the spokes J are fixed.
In each recess formed by the flanges K2 K3 and web K¹ is fixed the pin wheels
or discs L L above described, being secured to the hub by screwing on to the
bosses K as shown on Fig. 2, or they can be fixed in any other convenient manner.
By the arrangement herein described, the driving mechanism is placed centrally
with a
revolving shaft on each side of the machine to convey the driving power
and the gear can be readily varied by the rider without stopping, the change of gear
taking place with equal facility, whether the machine be in rapid or slow motion,
or even when pedalling backwards.
Having now particularly described and ascertained the nature of the said inven-
tion, and in what manner the same is to be performed, I. declare that what I
claim is
1. In variable central double driving gear for cycles and the like, a disc or
wheel I placed centrally on the crank axle with one or more rings of pins on each
of its sides for the purpose described and illustrated in the accompanying drawings.
2. In variable central double driving gear for cycles, and the like, the construc-
tion with a central web K¹ which forms part of the hub of the rear road wheel,
of a disc L with a ring of pins on each side of the web K¹ substantially as and for
the purpose described.
3. In variable central double driving gear for cycles, and the like, a hub K of
a road or rear wheel, extended and recessed on both sides K2 K3, having discs with
pins fixed therein, projecting therefrom parallel to the axis about which the star
gear wheels H rotate as described and illustrated.
4. In variable central double driving gear for cycles or the like, the combination
with a driving wheel D, having pins on both its sides of two revolving shafts G G
with ball bearings at each end, each shaft carrying a star gear wheel H I one at
each end, the wheel H engages the discs L L on the hub of the road wheel, and
the gear wheel I engages either of the rings of pins of the driving wheel D by
sliding on the shafts G G substantially as described and illustrated in the accom-
panying drawings.
5. In variable central double driving gear for cycles and the like described
operating simultaneously two sets of gear changing mechanism by a common lever,
or other reciprocating mechanical means substantially as described.
6. In variable central double driving gear for cyclés and the like, the complete

page_text: gear changing mechanism substantially as described in the accompanying
drawings.
7. The combination and arrangement of parts constituting the complete variable
speed gear, acting centrally for cycles, and the like, substantially as described and
illustrated in the accompanying drawings.
1011 1