Improvements in Speed-varying Gears for Chainless Velocipedes.
Year: 1897

page_text: PROVISIONAL SPECIFICATION.
Improvements in Speed-varying Gears for Chainless Velocipedes.
I, JOSEF SCHLASCHL, of Pola, Austria, Engineer of Royal Imperial Navy, do hereby
declare the nature of my said invention to be as follows:-
-
This invention relates to improvements in that class of speed varying gears for
chainless velocipedes wherein a wheel with two circles of teeth is keyed upon the
crank axle in gear with two wheels mounted upon the transmission shaft which
latter wheels are alternately keyed upon the driving shaft, the object being to
provide an improved method of keying and unkeying the two wheels upon the said
transmission shaft.
To this end a disc having two concentric circles of teeth is keyed upon the crank
axle in the usual way, each of the said circles of teeth being in gear with a bevel
pinion mounted loosely. on the transmission shaft.
The transmission shaft is hollow and placed around a bar of the frame as is usual
in chainless velocipedes and retained longitudinally in position by means of ball
bearings arranged at each end.
The bevel wheels on the transmission shaft are retained in their relative position
apart, partly by the cup of the ball bearing near the crank axle and partly by two
muts.
The portion of the transmission shaft between the said two bevel wheels is formed
hexangular on which is adapted to slide a sleeve furnished at each end with six
keys fitting against the middle of the surfaces of the flats of the hexangular part
of the transmission shaft. The space between the said keys is filled up at each end
by six other keys which when the said sleeve is displaced longitudinally expand
and press a conical ring formed in six segments against the interior of the said bevel
wheels respectively, whereby one of the said. wheel will be coupled with the trans-
mission shaft.
To prevent the said segmental rings leaving the interior of the said bevel wheels
they are formed with flanges which engage in corresponding grooves in the said
wheels.
To prevent the said section rings turning in the said wheels the latter are inter
nally formed with midfeathers which project between the said segments.
For the purpose of moving the said sleeve longitudinally the latter is embraced
by a rings as is usual in couplings and in order to prevent friction a ball race is
formed between the same.
The said ring, which may be formed in one or two parts, is formed diametrically
opposite with pivots, which engage in the usual way in a forked lever keyed upon
a rod.

page_text: The upper end of this rod is furnished with crank handle locked in position by
a pawl attached to the upper part of the frame of the velocipede.
F. BOSSHARDT & Co.,
Agents to Applicant.
Improvements in Speed-varying Gears for Chainless Velocipedes.
I, JOSEF SCHASCHL, of Pola, Austria, Engineer of Royal Imperial Navy, do hereby
declare the nature of this invention and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following state-
ment:-
This invention relates to improvements in that class of speed varying gears for
chainless velocipedes wherein a wheel with two circles of teeth is keyed upon the
crank axle in gear with two wheels mounted upon the transmission shaft which
latter wheels are alternately keyed upon the driving shaft, the object being to pro-
vide an improved method of keying the said two wheels upon the said transmission
shaft and unkeying same.
And in order that my invention may be more fully understood I have caused to
he appended hereunto one sheet of drawings marked with letters of reference
indicating like parts in the various figures, Fig. 1 being a side view of a bicycle
furnished with my improved chainless driving gear, Fig. 2 a section through the
crank bearing and transmission shaft, Fig 3 a cross section on line of Fig. 2,
and Fig. 4 a perspective view of the coupling shown at an enlarged scale.
In carrying out this invention and referring more particularly to Figs. 2, 3 & 4,
I key upon the crank axle A in the usual way a disc B having two concentric
circles of teeth 131, 132 each of which is in gear with a bevel pinion b1, b2 mounted
loosely on the transmission shaft a.
The transmission shaft a is hollow and placed around the bar g of the frame
as is usual in chainless velocipedes and retained longitudinally in position by means
of ball bearings g¹, a³, arranged at each end.
The bevel wheels 61, 62 on the transmission shaft a are retained apart in their
relative position near the crank axle by the ball bearing cup a and partly by nuts,
viz. an ordinary nut and a lock nut a², a respectively screwed onto the transmission
shaft a.
The part a of the transmission shaft a between the two bevel wheels b¹, 62 is
formed hexangular, see Fig. 3, and upon the same is adapted to slide a sleeve f
formed with a corresponding hexangular hole. In the middle of the said sleeve
is formed externally an annular groove f adapted to receive anti-friction balls
whereby the said sleeve is divided symmetrically in longitudinal halves, each of
which is formed hexangular in pyramid fashion tapering towards each sleeve end
and the surfaces f¹, f2 of which are respectively separated from each other by
means of ribs f³, fs formed thereon.
9
Between the bosses 63, 64 of the bevel wheels b1, b2 and the corresponding sur-
faces f, f of the sleeve f, keys cl, care employed respectively, which are kept in
position laterally by means of the ribs f, f on the said sleeve and longitudinally
by flanges ³, formed thereon respectively, which flanges engage in the
grooves 5, 6 formed in the bosses of the wheels 61, 62.
The upper surfaces of the said keys are each curved to a radius smaller than that
from the centre of the shaft a. In consequence of this the interior of each wheel
boss is not bored out cylindrically but formed with small cavities 67 the radius of
which corresponds with that of the said keys.

page_text: For the purpose of displacing the sleeve f which carries the keys c¹, &, the
groove f in the sleeve f, is embraced by a ring h of corresponding section, anti-
friction balls f being employed between the groove f³ and the ring / whereby
the friction between the rotating sleeve ƒ and the stationary ring his reduced to
a minimum.
The ring h, which may be formed in one or more parts, is formed diametrically
opposite with pivots h¹, h² which engage in the usual way in a fork H', which
through the eye H³, is secured to and can be actuated by a suitably mounted rod H.
The rod H near its upper end is mounted in a bracket suitably secured to the
top bar of the velocipede and has secured to the respective extremity a crank
handle H2 rendered suitably adjustable below the said top bar.
The mechanism described thus operates as follows:-
When turning the crank handle H3 in one or the other direction, the sleeve f
will cause either the keys c¹ or c³ to be forced against the interior of the boss of the
wheel or b².
During this displacement of the keys c¹ or ², they will slide outwards in the
cavities of the boss of the wheel to be coupled, until they are in the position in
the cavities in which the coupling of the respective wheel takes place reliably.
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:-
:-
1st. In speed varying gears for velocipedes of the type herein before referred to,
a device for alternately keying the bevel wheels 1 & 2 to and unkeying the same
from the transmission shaft a, consisting chiefly of a sleeve f keyed longitudinally
movable upon the said transmission shaft and having externally a number of
symmetrically formed flats fl, f tapering from the middle towards each end and
adapted to receive the keys & surrounded by the hollow bosses 63, 64, all sub-
stantially as set forth.
2nd. In a coupling such as specified in the preceding claim, the keys c¹ & o²,
formed with flange like projections 3 &c, adapted to enter the grooves b & b
formed respectively in the interior of the said wheel bosses, all substantially as
set forth.
3rd. In a coupling such as specified in Claim 1, the keys c¹, c³ the outer surfaces
of which are curved to a radius smaller than that from the centre of the shaft a,
all substantially as set forth.
4th. In a coupling such as specified in Claim 1, the cavities 67 formed in the
interior of the wheel bosses b³, 6+, all substantially as set forth.
5th. In a coupling such as specified in Claim 1], the employment of a ball race
between the sleeve f and the coupling ring h, all substantially as set forth.
Total thin 14
F. BOSSHARDT & Co.,
4, Corporation Street, Manchester, Agents to Applicant.