Improvements in Speeding Gear of Bicycles.
Year: 1896

page_text: Date of Application, 6th July, 1896-Accepted, 17th Oct., 1896
Improvements in Speeding Gear of Bicycles.
I, WILLIAM WANLISS, of 48 Marshall Street Johannesburg, South African
Republic, 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 :-
My invention relates to improvements in the driving of bicycles, whereby a
change of speed gear may be effected without necessity for the rider to dismount
or to stop his machine.
Fig. 1. is an elevation of part of a bicycle to which my invention is applied.
Fig. 2. is a section, Fig. 3 is a plan and Figs. 4 & 5 show details to an enlarged
scale.
In carrying out my invention the hub of the hind wheel is forged on a hollow
spindle (Y) or to which latter it may be pinned or keyed, and I use two sprocket
pinions (I and J), respectively with six or eight teeth (or more or less as may be
desired) on the same spindle, on which they revolve on plain or ball bearings, a
flange (K) is cast or forged on the outer side of the sprocket pinions, and to which
the catches (A and C) and the tumblers (B and D) are attached by stud pins
which pass through them and are screwed into the flanges (K. K), the springs (U. U)
for keeping the catches in place are also attached to the latter. The tail end
of the catches (A¹ and C¹) and the tumblers (B and D¹) which come in contact
with the projections on the releasers (A. B. C. D) are turned respectively to the
right and left and are so placed that each catch and tumbler will be acted on by
its respective releaser only. Two discs (L. L¹) are screwed on to the spindle
respectively with a right and left hand screw, on the outer side of the flanges,
their use being to keep the sprocket wheels in their places close up to the hub of
the hind wheel between which and the discs (L. L') I place thin washers to lessen
the friction between them, the principal use of the discs is however, to drive the
machine by engaging with the catch by means of the notch (f) or notches in their
peripheries. The ends of the spindle (Y) are turned to fit into ball bearing sliding
blocks (Q. Q), one on each side of the frame, in which they are made to slide, and
which is suitably constructed to receive them. A sleeve (W) is fitted over both
ends of the spindles and is kept from turning by feather (k) fitting in a groove in
the spindle. A set nut (Z) kept in position by an outer jam nut (Z), forces the
end of the sleeve which is suitably formed, underneath the balls in the bearings
to take up any wear of the latter, an outer metal cap (R) is screwed over the nuts
to prevent any dust or dirt entering the bearings. The rear of each block (Q)
has a lug (m) forged or cast in the centre to receive a stud bolt, the other end of
which passes through a cross head (T) fitted on the end of the frame, and which is
set up or tightened by a nut on its outer end, its purpose being to take up the slack
of the sprocket chains (O and P). At the opposite ends of the sliding bearing
blocks (Q.Q) and on their inside edges I form another lug (n), which is attached
to an eye bolt (h), passing through a sliding block (V) in which the releasers
work, the use of the bolt being to keep the releasers and the bearing blocks (Q. Q)
in their relative positions, when the chains are being tightened by screwing up the
tightening bolts (T) and also to take up any wear and tear of the releasers by
means of a second nut (h) on the forward end of the releaser blocks (V) which
slide in guiding slots (S and S2) formed in the frame on the forward side of the
wheel, where they are kept in place by stud bolts (b. b.) which pass through the

page_text: frame and have nuts on their outer ends to draw the sliding blocks (V) close to
the sides of the slots (S' and S2) and to fix them in position after tightening up the
chains. In the releaser blocks I form an oblong slot, in which the two releasers
work side by side with an upward and downward motion. These releasers are
made with suitably formed projections and rise and fall about g of an inch so as to
allow the catches and tumblers to pass underneath them after the levers, having
been manipulated for the purpose of changing speed, have risen again to their
normal position by means of the springs on the upper ends of the rods, the releasers
are projected upward in the form of a rod, which pass through guides (D3) attached
to the rear angle stay, and their upper extremities are formed with a long slot
through each of which passes the end of one of a pair of cross arms (E. E¹), fixed
to one spindle (F), to which latter also is fixed one of a pair of lever handles (G)
each of which works the cross arm (E). The other cross arm (E) is fixed to
a sleeve, fitted on the spindle to which its before described fellow cross arm (E) is
fixed. This sleeve revolves freely on the spindle (F) and is actuated by the other
lever handle (G1). Thus each lever, and consequently each cross arm and pair of
releasers work independently of the other, the handles lying side by side so as to
be readily manipulated by one hand. My object in using two sets of levers is to
prevent the catch on the one side of the machine falling into the notch before the
opposite catch is set free by its tumbler, a condition which would result in the
locking of both discs. Two or more rods may be used as required with four rods
the change of gear can be effected while the machine is in motion at full speed,
but with two rods it would be necessary to slow down before effecting the change
of gear. Spiral springs (H. H) are fitted to the upper ends of the releaser rods
which raise and retain the releasers about of an inch, from the releaser block,
pins being inserted through the rods to form stops against the guides (D³) to
prevent the rods rising higher, washers and pins on the top ends of the springs (H.H)
serve to keep them in place and on which their pressure is exerted for raising the
rod to the required height.
The end of the rear angle stay is formed with an arm (F) projecting above the
bolt for tightening the saddle bar, and through which passes the hollow steel
spindle (F) on which the levers (G. G') and the cross arms (E. E') are fixed.
Two sprocket wheels (M. N) with any requisite number of teeth, according to
the gearing required, are fitted in the following manner to the crank spindle (S).
The spindle is made somewhat longer than in the ordinary single geared machine,
so as to allow room for a sprocket wheel on either side of the bottom bracket, a
shoulder being turned at each end of the spindle against which the hubs of the
driving sprockets rest, on the outer face of the hub of the sprocket, a notch (E³)
(on plan) is cut and on the inner face of the crank a tongue (E³) is formed which
corresponds with and fits into the notch in the hub, the pin which holds the crank
in position on the spindle, is wedge formed so that when driven home it forces the
tongue on the inner face of the crank into the notch on the outer face of the hub
of the driving sprocket.
A projection (T) is cast on one of the spokes of the sprocket corresponding
with a similar projection (T) on the inner face of the crank arn, a small bolt
passing through the two connects the crank arın firmly to the sprocket, the strain
ou the hub of the latter when driving being thus greatly reduced. All sprockets
are made interchangeable from one side to the other.
METHOD OF WORKING.
When travelling on a level road the high speed gear will naturally be used, the
point of the high speed catch (A') is then in the notch (f) of the disc (L) beside
the smallest sprocket pinion (1) and is held there by the spring (U) on the
flange (K) the machine being thus set on the high speed gear. Should a rising
grade be encountered by the traveller, he will then require the speeding of the
machine to be changed from high to low speed, in order to lessen the labour and

page_text: exertion necessary to drive the machine up a rising gradient. This is done,
without necessity for the rider to dismount and whilst still travelling, by pressing
down the lever (G) which depresses the catch releaser (B) and allows the tail of the
catch (A) to strike against the releaser and be raised and locked out of gear by
the tumbler (B1). The machine is now out of gear, and to put it on the slow
speed the handle (G) is lifted which by means of the rear end of the cross
arm (E) depresses the catch releaser (D), the tail end of the tumbler (DI) then
comes round and strikes the releaser and allows the catch (C) to fall into a notch
in the disc (L') where it is locked and held in place by the spring (U). To
change again from slow to high speed the actions of the levers are simply
reversed.

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, I would observe in
conclusion that what I consider to be novel and original and therefore claim as
my invention is :-
1. In differential speeding gear for bicycles. The sprocket pinions (I and J)
revolving loosely on the after spindle (Y); the flanges (K) formed on their hubs;
the catches (A and C¹); the tumblers (B and D) attached to the flanges by
stud pins; the springs (U. U); the catch and tumbler releasers (A. B. Č. D);
the sliding blocks (Q. Q) in which the ends of the spindle (Y) revolve; the sliding
blocks (V. V) in which the catch and tumbler releasers work; the discs (L. L)
having notches in their peripheries into which the ends of the catches fall and
lock; the secondary slots (S1 and S2) in which the releaser blocks which are
secured by the stud bolts (b. b) slide; the cross arms (E. E'); the levers (G. G¹);
the extension of the back stay of the present form of bicycle above the saddle
bolt (a) in the top of which the spindle (F) is set as shown at (F1), substantially
as described in the foregoing specification and on the accompanying drawings.
2. In differential speeding gear for bicycles. The general construction,
adaptation or application, and the combination and use of the several parts in
the whole, constituting improved, more simple, and efficient appliance or means for
rapidly changing the speed of bicycles when travelling from high to low speed
or vice versa, without requiring the rider to dismount or to stop his machine,
substantially as described in the foregoing specification and on the accompanying
drawings.
Dated this 6th day of July 1896.
CARPMAEL & Co.,
Agents for the Applicant.