Improvements in Gear Wheels.
Year: 1896

page_text: Date of Application, 28th Sept., 1896-Accepted, 21st Nov., 1896
Improvements in Gear Wheels.
I, CHARLES AUGUSTUS TREDWELL, a citizen of the United States, residing
at Bristol, County of Hartford, State of Connecticut, United States of America,
Inventor, 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 :-
The object of my invention is to produce an improved gear wheel which, being:
especially designed for use in bicycle bells, is adapted to impart rotary movement
to the mechanism thereof, and at the same time to present to the thumb or finger;
of the operator a smooth finished, effectual and mild operating surface.
In the accompanying drawings :
Fig. I is a top plan view of my wheel incorporated with a species of bicycle bell,
mechanisms;
Fig. 11 is a section of the same, taken through the stud pin, upon which the gear
revolves, and that of the intermeshing gear;
Fig. III illustrates in group the component parts of the preferred form of my
gear;
Fig. IV is a perspective view of the same united ;
Fig. Villustrates in group the component parts of a modified form of my
gear.
Referring to the figures on the drawings:
1 indicates the base of a bicycle bell, which is illustrated merely by way of
example of mechanism with which my gear is especially adapted to be used.
2 is an intermediate gear incorporated in bicycle bell mechanism, and which is
pivoted upon a pin 3 projecting from the base.
4 indicates a stud pin located in proximity to the usual aperture 5, which, in
bells of this class, are designed to accommodate an operating gear. It is in such a
gear that my invention resides.
The gear consists of a pair of plates 6 each provided with concentric apertures
adapted to receive the reduced ends 7 of a bushing 8. One or both of the plates
is provided with a series of teeth 9 which are formed in the plate, and are after-
wards struck up at right angles to the plate so as to resemble somewhat a crown
gear. The teeth of the two plates correspond and when united upon the bushing
fit opposite to each other. When fastened together, they constitute in effect a
kind of cage gear, each pair of abutting teeth in the opposite plates constituting a
cog pin 10.
In practice I prefer, as above stated, to form teeth in each of the plates, and to
strike up the tooth edge of each of the plates by the use of dies, or other suitable
mechanism. After the plates are formed they are placed in position upon the
bushing and the parts are firmly united as by brazing, or by forced enlargement of
ends of bushing.
The important feature of my completed gear is that each of the cog pins is
perfectly flush with the edge of the plate so that while it affords a positive
co-operation with an intermeshing gear, it presents a comparatively smooth surface
to the thumb or finger of an operator, affording just enough friction to drive it
freely without being severe in its action against the surface of the hand which
drives it.
Although I prefer to make my wheel in two corresponding parts, and to form
the teeth, which when united constitute the cog pins, equally upon both of the

page_text: side plates, yet, as illustrated in Fig. V, it is practicable to form the teeth entirely
upon one plate and to fit them against the opposite plate.
My gear as applied to a bicycle bell is preferably secured to the stud pin 4,
by means of a screw 13 screwing into the end of the pin, and an intermediate
washer 14.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is :-
1. In a gear wheel, the combination with a pair of plates, of cog pins uniting
the same, the outer surfaces of the cog pins being flush with the edges of the plates,
substantially as set forth.
2. A gear consisting of a pair of plates, of cog pins uniting the same, said pins
being formed by teeth struck up from one or both of the plates, and united together,
substantially as set forth.
3. A gear consisting of a pair of plates provided, respectively, with teeth struck
up from their edges, respectively, and united together to form a whole, substantially
as and for the purpose specified.
4. The method of making gear wheels, which consists in forming teeth upon the
edge of a circular plate, afterwards striking up the toothed edge at right angles to
the plate and uniting the teeth to a second plate to form cog pins between the two
plates, substantially-as set forth.
Dated this 28th day of September 1896.
CHARLES AUGUSTUS TREDWELL.
Jensen & Son,
77, Chancery Lane, London, W.C., Patent Agents.