Year: 1899

page_text: I, WILLIAM CITATER LEA, of 116 to 120, Golden Lane, in the County of London,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to clutch-gear and is more especially designed for use in
velocipede driving mechanism although it is applicable to many other uses.
According to my invention as applied to the driving gear of a rear-driven
bicycle I form on, or secure to, the hub of the driving wheel an annular toothed
rack. Outside, and free from, this annular rack is the chain wheel which is held
in position between two side plates. That part of the chain wheel nearest to
the toothed rack is provided at intervals with segmental openings and at corre-
sponding intervals one of the side plates is provided with D-shaped or other
suitable recesses. Into each said segmental opening and recess a D-shaped block
of metal is loosely inserted, that part of the block which drops into the said
recess being rouned off so as to form a trunnion. A small spring in compression
located within the said recess normally thrusts the one edge of the D-shaped
metal block into a notch of the annular rack herein before mentioned. In this
position the annular toothed rack and the chain wheel rotate as one but upon
the pedals of the bicycle, and with them the chain wheel, being temporarily
stopped, the driving wheel, and with it the annular toothed rack, will continue
to rotate, the said D-shaped metal blocks partially rotating about their trunnions
and returning under the influence of their springs.
In addition to forming separate D-shaped recesses in the one side plate as
hereinbefore described I may in some cases provide the opposite side plate with
an annular recess or separate bearings and form journals on the ends of the said
D-shaped blocks to engage therein and thus prevent the D-shaped blocks from
sagging in their respective recesses in case of wear or loose fitting.
Dated this 6th day of June 1899.

page_text: the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
My invention relates to clutch-gear and is more especially designed for use in
velocipede driving mechanism although it is applicable to many other uses.
In the accompanying drawings which show a gear ring designed for applica-
tion to the hub of the driving wheel of a rear-driven bicycle,
Figure 1 is an elevation with the rear plate d removed.
Figure 2 is an obverse view of the removed plate.
Figure 3. is a transverse section on the line A, B, Figure 1, part of the wheel
hub, spindle and adjacent frame members being shown in broken lines.
Figure 4 is a similar view to Figure 3, showing a modified form with ball
bearings.
Figure 5 is a part view similar to Figure 3 illustrating a modification, and
Figure 6 shows in perspective one of the pawls f.
According to my invention, as applied to the driving gear of a rear-driven
bicycle, I form on, or secure to, the hub of the driving wheel an annular toothed
rack a.
Outside, and free from, this annular rack is the chain ring b which is
held in position between two side plates c and d. These plates are held together
by screws or other suitable means. That part of the chain wheel nearest to
the toothed rack is provided at intervals with segmental openings and at corre-
sponding intervals the side plate c may be provided with D-shaped or other
suitable recesses. Alternatively the said side plate may be provided with an
annular flange c¹. Into each said segmental opening in the chain wheel a D-
shaped block of metal or pawl f is loosely inserted, that part of the block which
drops into the said recess or bears upon the annular flange being rounded off
so as to form a trunnion. A small spring in compression g located within the
said recess normally thrusts the one edge of the pawl f into a notch of the
annular rack a. In this position the annular toothed rack a and the chain ring
rotate as one but upon the pedals of the bicycle, and with them the chain wheel,
being temporarily stopped, the driving wheel, and with it the annular toothed
rack a, will continue to rotate, the said D-shaped metal blocks or pawls f
partially rotating about their trunnions and returning under the influence of their
springs g.
In addition to forming separate D-shaped recesses on the said annular flange c¹
in or upon the side plate e as herein before described I may in some cases provide
the rear or other plate d with centres h, (or instead thereof an annular groove
or recess) to serve as bearings and form journals or pivots on the ends of the
pawls to engage therein and thus prevent the said pawls from sagging in
their respective recesses in case of wear or loose fitting. Figures 1, 3, 4 and 6
show the pawls f provided with the journals or pivots and Figure 5 illustrates
the construction without them.
In some cases I may, as shown in Figure 4, insert ball bearings ; between
the annular toothed rack a and the chain wheel b.
Obviously instead of the pawl driving the ratchet as in the arrangement herein
described, the ratchet may be arranged to drive the pawls.
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. In a clutch gear one or more pawls f substantially as described.
2. The combination, in a clutch gear, of one or more pawls such as f and
compression springs such as g, substantially as described.
3. In a clutch gear, the combination with an annular toothed rack and a chain
ring, of one or more spring-actuated D-shaped pawls, and a side plate having
recesses or an annular flange to receive the rounded-off portions of the pawis
substantially as described.

page_text: 4. In a clutch gear, the combination, with an annular toothed rack and a chain
ring, of one or more spring-actuated pawls with rounded-off portions to form
trunnions on the one side and pivots or journals on the other side, and two side
plates one having recesses or an annular flange to receive the rounded-off por-
tions of the pawls and the other having bearings to receive the pivots of the
pawls substantially as described.
5. The clutch gear constructed substantially as described with reference to
Figures 1 to 4, or to Figure 5 of the accompanying drawings.
Dated this 28th day of February 1900
A. F. SPOONER,
323, High Holborn, London, Agent for the Applicant.