Improvements in Speed Reducing Mechanism for Driving Cycles.
Year: 1891

page_text: Date of Application, 12th Nov., 1891-Accepted, 9th July, 1892
COMPLETE SPECIFICATION.
Improvements in Speed Reducing Mechanism for Driving Cycles.
We ROCHESTER ILLINGWORTH of Hill Street Coventry in the County of
Warwick, Manager and JOSEPH BUSH of Gas Street Coventry Engineer do
hereby declare the nature of our said invention and in what manner the same is to
be performed to be particularly described and ascertained in and by the following
statement:-
Our invention has for its object improvements in speed reducing mechanism for
driving cycles by which means we obtain a compact simple and cheap means for
driving safety bicycles and tricycles at a reduced speed from that of the driving
crank so as to suit the variable conditions under which the machine has to travel
as in the case of ascending a hill or under other difficult conditions a reduction of
the speed of the machine by this means creates an increase of power and ease in
driving and this we effect with the smallest possible amount of extra bulk or weight
in the driving mechanism..
By this said arrangement of gearing the chain wheel in its normal condition
i.e. when on level or easy roads is driven direct for speed while for power and ease
of driving the speed of the driving chain wheel is reduced from that of the crank
shaft by means of toothed wheels of varied sizes and an intermediate pinion or
pinions.
In order that our invention may be clearly understood and more easily carried
into practice we have appended hereunto a double sized sheet of drawings upon
which we have fully illustrated the nature and working of our said invention.
Figure 1 is an elevation of the chain wheel with part of one of the side plates
broken away to shew the internal mechanism.
Figure 2 is a section through Figure 1 on the line 1-2.
Figure 3 is an end elevation of the chain wheel complete.
Figure 4 is an elevation of the centre tooth wheel and the side plate to which it
is fixed.
Figure 5 is an elevation of the chain wheel with all other parts separated
therefrom.
In carrying our invention into effect we firmly key or otherwise secure the plate
wheel A to the crank driving spindle B at one side of the chain wheel D and
around the circumference of the plate wheel A the internal teeth a' are provided.
Upon the other side of the chain wheel the side plate E is mounted upon and
independently of the crank spindle in such a manner as to allow of being locked or
fixed to any convenient part of the crank spindle support and provided with the
projecting journal e and upon this journal the chain wheel is mounted so as to
revolve indepandently of it. Upon the chain wheel the studs d¹ and d² are fixed
and upon these studs the cog wheels F and F¹ are mounted so as to gear both with
the internal teeth a' of the plate wheel A. and with the toothed wheel e² which is
fixed to the bush e' so as to form a part of the side plate E. It will thus be seen
that as the crank spindle revolves it carries around with it the toothed wheel a¹
which in turn revolves the toothed wheels F & F¹ which engaging as they do with
the fixed toothed wheel e² are caused to rotate as they revolve carrying with them
the chain wheel at a speed reduced in proportion to the difference in the sizes and
number of teeth in the relative toothed wheels a' and e².
In the normal condition when the highest speed is required the side plate E is
unlocked from the fixed part of the cycle and is locked to the chain wheel D so
that the whole of the mechanism revolves together this being effected by reason of
the inability of the pinions F and F¹ to revolve when the side plate E is locked to

page_text: the chain wheel D and thus the toothed plate wheel A carries with it the pinions
and with them the whole of the mechanism.
We lock and unlock the parts in the manner shewn and described by
Specification No. 15519 A.D. 1890 in which case the bolt C referred to in that
Specification is mounted upon the side plate E herein referred to while the slotted
ring with which the said bolt engages is fixed upon the chain wheel D.
We may confine ourselves to the use of one pinion F only or we may have more
than two but generally we prefer to use two as shewn which is sufficient to prevent
any undue back lash while at the same time the two wheels F and F1 balance cach
other & do not form any material addition to the weight. Though we have
explained the best mode by which the speed is reduced from the normal condition
we do not lay claim to the principle of the "sun & planet" motion but to the neat
& effective mode of mounting and using the whole combination herein described.
Ball bearings may be formed between the chain wheel D & the fixed bearing
bush e so that when the chain wheel D is running at reduced speed the friction is
but slightly more than when the chain wheel is running at the same speed as the
spindle & ball bearings may be formed on each side between the crank shaft B and
inside bearing e³.
The amount of the reduction of the speed is determined by the relative number
of teeth in the two wheels a¹ and e2 and any alteration of the amount of speed
reduced is effected by a variation in their relative sizes.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed we declare that what
we claim is :-
:-
The improvements in speed reducing mechanism for driving cycles consisting of
the part A in combination with the locked part E and with the intermediate wheel
or wheels mounted upon the chain wheel D substantially as and for the purposo
herein set forth and shewn upon the accompanying drawings.
Dated this 10th day of November 1891.
GEORGE BARKER,
77, Colmore Row, Birmingham, Agent for Applicants.