New or Improved Changeable Driving Gear for Chainless Cycles.
Year: 1898

page_text: Date of Application, 7th May, 1898-Accepted, 9th July, 1898
COMPLETE SPECIFICATION.
New or Improved Changeable Driving Gear for Chainless Cycles.
I, PETER VILHELM FJELSTRUP, of 36, Gl. Strand, Copenhagen, in the Kingdom
of Denmark, Dentist, 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:―
A long felt want in connection with chainless cycles is a light, convenient
and efficient changeable gear.
The present invention is intended to meet the said want; and it consists of
gear which can be changed while riding without necessitating the dismounting
of the rider.
The invention is illustrated in the accompanying drawings, wherein,
Figure 1 is a horizontal section,
Figure 2 a part side elevation and part longitudinal vertical section, and
Figure 3 a detail.
The movement is transmitted by cog-wheels somewhat in the well known
manner but, instead of employing ordinary bevel gear the large bevel wheel 2
on the crank shaft 1 is double, that is to say it has two conical circles 3 and 4.
of cogs turned towards one another. The cogs in the outer circle 3 are formed
like the teeth of lantern wheels, whilst the inner circle 4 has teeth of ordinary
form. On the transmitting shaft 5 is flxed the double cog wheel 6. This is
of the form of a double truncated cone and on the side which engages the tooth
wheel 4 there are the usual teeth, whilst on the other side are spokes or studs
which gear in the lantern wheel 3. The cog wheel 6 is longitudinally loose on
the shaft 5, that is to say it can be moved lengthways on the shaft, but is (by
means of a stud and notch or the like), obliged to take shaft 5 with it when it
rotates. When in its normal position the cog wheel engages the tooth wheel 3,
which gives a high gear, and is therefore used when riding on good and level
roads. It is kept in this position by a spiral spring 7. Passing over the end
of shaft 5 is a stirrup 8 attached to cog wheel 6. The stirrup 8 bears a pivot-
stud 9 with a mushroom head, covering balls, and so forming a ball bearing.
A second stirrup 10, together with the parts 8 and 9 constitutes a universal joint
in this case of a well known form. From the stirrup 10 a chain 11 passes over
the pulley 12 on the bracket 13, up the diagonal tube 14 and out at a catch-
slot 15 cut in the wall of said tube some distance below the saddle. To the free
end of said chain a ring or the like is attached.
When it is desired to make use of the low gear, whether on going up hill or
on bad roads, the chain 11 is pulled, and the cog wheel 6 moved to the end of
shaft 5, when the studs cease to engage the lantern wheel 3, and the teeth on
the opposite side of wheel 6 gear with the toothed wheel 4. The parts may be
retained in this position by a broad link on chain 11 being put outside the
smaller part of the catch-slot in the tube 14 as shown in Figure 3.
•

page_text: 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:
1. The new or improved changeable driving gear for chainless cycles sub-
stantially as set forth.
2. The arrangement and combination of parts substantially as set forth.
3. The employment of double acting bevel gear in combination with a universal
joint substantially as and for the purpose set forth.
Dated this (th day of May 1898.
For the Applicant,
J. G. LORRAIN, M.I.E.E., M.I. Mech. E.,
Chartered Patent Agent.