Year: 1896

page_text: JOHN BENNETT, Machine Fitter, Ilkeston Road, Marlpool, Derbyshire WILLIAM
RENSHAW ROOTH Cycle Maker and Agent No. 58 High Street Heanor Derbyshire.
We do hereby declare the nature of this invention to be as follows:-
To one end of bottom bracket is fixed a stationary spur wheel. To side of spur
wheel and keyed to crank axle is a circular plate carrying small spur wheels, rotating
on ball bearings & geared into stationary spur wheel, to the said circular plate is also
attached flanged rollers, rotating on ball bearings, to carry and guide an internally
cut ring, geared into the small wheels. The outer diameter of said ring is cut to
pitch of chain used.
The said internally cut ring is rotated & levered by the intermediate spur wheels
rotating round the stationary spur wheel on bracket thus gaining increased power
and speed.
1000
JOHN BENNETT.
WILLIAM RENSHAW ROOTH.
We, JOHN BENNETT of 33 Ilkeston Road, Marlpool, Mechanic, and WILLIAM
RENSHAW ROOTH, of High Street, Heanor, Cycle Manufacturer and Agent, both in
the County of Derby, 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 improvements in speed gear mechanism applicable to
chain driven cycles or the like.
The invention will be best understood by reference to the accompanying drawings
in which
Fig. 1 is a side elevation showing gearing constructed according to our
invention applied to a safety bicycle, the outer plate or cover and crank being
removed.
Fig. 2 is a sectional elevation on the line X X of Fig. 1 and,
Fig. 3 a sectional elevation on the line Y Y of Fig. 1.
Like letters indicate like parts throughout the drawings.
On one end of the crank axle A, which may be mounted in a bracket bearing A¹
of the usual form, is a circular plate or disc B. This plate or disc may be secured
directly to the crank axle or to the crank C, which latter is secured to the crank
axle in the usual way.
Mounted preferably on ball bearings on pivots D which may be adjustable, and
are secured to the plate or disc B, and parallel to the crank shaft, are preferably
four antifriction rollers E. These rollers E are reduced in diameter in the middle

page_text: and all form a bearing for an annulus F provided on the exterior with teeth F¹ to
engage with the driving chain, and on the interior with teeth F2 to engage with
preferably two intermediate toothed wheels G (see Figs. 1 and 2).
The teeth F2 lie in the reduced middle part of the antifriction rollers E and the
ring F is thus prevented from moving laterally.
The wheels G are mounted preferably on ball bearings on pivots H secured to
the plate or disc B these pivots being arranged parallel to the pivots D before
mentioned.
The teeth of the wheels G also engage with a fixed toothed wheel J placed
concentrically with the crank axle A. This wheel may be secured to the end of
the bracket bearing A¹ or to an extension of the adjustable ball bearing cup A
as shown.
The whole arrangement may be enclosed on the inner side by a plate K (see
Figs. 2 and 3) corresponding to the outer plate or disc B which forms an outer
cover. The plate K is bolted to the ends of the pivots D and H.
It will be seen that the wheels J and G and the annular toothed wheel F form
an epicyclic train of wheels and that the ring F will rotate quicker than the crank
axle. The rollers E which carry the ring Falso move round the crank axle A in
the same direction as the ring F and the difference in their relative movements
and the cousequent friction between the two will be equal to that caused by the
difference in their velocities.
The arrangement described may be used as a differential speed gear by arranging
the wheel J so that it may be conveniently released from the bracket A¹ and
be connected or locked to either of the plates or disc B or K or to the crank
axle.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, we declare that what we
claim is :-
1. In a speed gear for cycles the combination with an axle A of a toothed ring
such as F and rollers such as E carrying the ring and moving round the axle,
substantially as and for the purpose described.
2. In a speed gear for cycles the combination with an axle A of a toothed ring
such as F rollers such as E carrying the ring and moving round the axle a fixed
wheel J and one or more intermediate pinions G moving round the fixed wheel,
substantially as and for the purpose described.
3. In a speed gear for cycles the combination with an axle A of a toothed ring
such as F roller such as E carrying the ring and moving round the axle A, a fixed
wheel J one or more intermediate pinions & and a disc or plate such as B carrying
the pivots of the rollers E and pinion or pinions & substantially as and for the
purpose described.
4. The combination and arrangement of parts constituting the complete speed gear
constructed and operating substantially as described and illustrated in the accompanying
drawings.
Dated th: 19th 1 ..
JOHN BENNETT.
WILLIAM RENSHAW ROOTH.
Boult & Wade,
Agents for the Applicants.