Improvements in and relating to Gear Wheels.
Year: 1895

page_text: his Print is in accordance with the Original Specification as it stands after
Amendment (under Section 11 of the Patents, &c., Act, 1883), as required
by the decision of the Chief Examiner of the 2nd day of February 1897.
Date of Application, 28th Sept., 1895
Complete Specification Left, 28th July, 1896-Accepted, 19th Sept., 1896
PROVISIONAL
Improvements in and relating to Gear Wheels.
I, PRESTON DAVIES, of Spencer House, West Hill Road, Southfields, in the
County of Surrey, Engineer, do hereby declare the nature of this invention to be
as follows:-
:-
My invention, which is more especially applicable to velocipedes though it may
be utilised for other driving purposes, consists essentially in providing, in lieu of
the well-known gear wheels with fixed projecting teeth, such wheels with hardened
steel or other suitable balls or spherical bodies projecting at intervals from the
periphery of such wheels to an extent less than the diameter of the said balls or
spherical bodies maintained in position upon the said wheels but free to revolve in
every direction. Two or more of these wheels may gear with one another or they
may be connected by a suitable chain or connecting band running between the
driving and the driven axles, shafting or hubs in the well-understood way.
I may prefer to construct the connecting chain or band with circular openings
or with hemispherical or similar depressions corresponding with the projections
formed by the balls on the gear wheels.
A convenient way of constructing my said wheels is to take a steel or other
suitable blank having a solid peripheral ring of a somewhat larger diameter than
that of the finished article. Circular apertures are drilled from side to side at
intervals around the said ring and afterwards such ring is cut away leaving some-
what more than half of the said apertures on the wheel, and forming, as it were,
a wheel with undercut projecting teeth. The wheel upon each side face is turned
down to a smaller diameter and screw-threaded exteriorly. Into the said apertures
the balls or spherical bodies are passed from one side of the wheel and since such
apertures are more than semi-circular the balls or spherical bodies cannot pass
outwards and they are maintained in position on either side by adjustable rings or
collars screwing over the hereinbefore-mentioned threads and clamped or otherwise
fixed in position. The said rings may or may not be formed with annular grooves
or the like for the better adjustment of the balls.
In driving gear constructed in manner described the friction at the point where
the chain or its equivalent leaves the gear wheels is materially lessened and the
system possesses many advantages over those now in use.
Dated thin 99th dow of Sentember 1895.

page_text: COMPLETE SPECIFICATION (AMENDED).
İmprovements in and relating to Gear Wheels.
I, PRESTON DAVIES, of Spencer House, West Hill Road, Southfields, in the
County of Surrey, Engineer, 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:-
My invention, which is more especially applicable to velosipedes though it may
be utilized for other driving purposes, relates to gear wheels which have, in lieu of
fixed projecting teeth, balls or spherical bodies imprisoned within, but projecting at
intervals from the periphery of, such wheels or from a flauged disc or distance-
piece to a sufficient extent to form teeth, and to engage with the links of the
driving or pitch chain or with another gear wheel. My said invention likewise
comprises an improved chain hereinafter described for use with the above chain
or gear wheels.
In the accompanying drawing
Figure 1 is a side elevation partly in section, illustrating one form of a chain or
gear wheel and chain constructed according to my said invention as applied to the
hub of a velocipede wheel.
Figure 2 is a similar view to Figure 1 showing another form or modification
thereof, and
Figure 3. is a similar view to Figures 1 and 2 showing the position assumed by
the balls or spheres at the point where the chain is leaving the gear wheel.
Figure 4 is a plan, and
Figure 5 is a side elevation both drawn to a greatly enlarged scale.showing a
further slight modification of construction hereinafter described.
Like letters indicate corresponding parts throughout the drawing.
Referring to Figure 1, a indicates the hub of a bicycle or other wheel. b.is.a
disc.or collar provided with recesses 61 to receive balls or spheres c and with
recesses to allow clearance for the joints or pivots of the chain. A convenient
manner of forming the sockets or recesses 61 for the balls or spheres c in the disc or
collar b is to take a steel or other suitable blank having a solid peripheral ring of a
somewhat larger diameter than that of the finished article. Circular apertures are
drilled from side to side at intervals around the said ring and afterwards such ring
is cut away leaving somewhat more than half of the said apertures on the wheel,
and forming, as it were, a wheel with undercut projecting teeth. Into the said
apertures the balls or spherical bodies c are passed from one side of the wheel and
since such apertures are more than semi-circular the balls or spherical bodies
cannot pass outwards, and they are maintained in position on either side by plates,
collars, or side flanges d screwed upon the hub a, only one of which plates, collars,
or side flanges is shown in the drawing.
is the chain the links of which are pivoted or jointed together as shown at e
and are provided with recesses e² to engage the ball or spherical teeth c. When in
position upon the wheel the pivots e¹ work, as shown; in the recesses 6 between the
ball or spherical teeth c in the disc or collar b, and in corresponding recesses d*
formed in the plates or collars d.
For convenience of manufacture I prefer to form the links e in. two parts
longitudinally, which parts are held together at the joints by shouldered rivets
also serving as pivots between the several links forming the chain.
In the modification shown in Figures 2 and 3 the recess b¹ in the disc or collar b
are formed so as to enclose the balls or spheres c to a distance less than, or only
just equal to, half the diameter. thereof so that they are free to leave the same.
To allow. the said balls or spheres c a certain amount.of play or movement during
work and at the same time to prevent their entirely leaving the said sockets 61
1...

page_text: I provide upon the collars or discs & projections & having grooves d'. It will be
seen that the balls or spheres c being carried in the peripheral and equi-distant
recesses or sockets b' and in the grooves formed upon the adjacent or inner
surfaces of the plates or collars d, a certain amount of play or movement of the
said balls or spheres c is provided and permitted in the latter for the purpose
hereinafter specified.
On the rotation of the chain e in the direction indicated by the arrows in
Figures 2 and 3, the balls or spheres will during a portion of the revolution of
the gear wheel engage equally in the sockets band in the recesses or arches e of
the chain links, but during its revolution through the remaining, or a certain angle,
each of the said balls or spheres c will rise or roll in the manner indicated at fin
Figure 3, thereby greatly reducing friction between the parts and especially at
that point where the chain or its equivalent leaves the gear wheel.
In the modification shown in Figures 4 and 5 the central disc or collar 6 and the
discs or plates d are formed in one piece. The holes or sockets 61 to receive the
balls or spheres c are drilled radially in the periphery thereof, and the latter are
retained therein whilst at the same time allowed a certain amount of play or
movement, by screws, pins, or projections 63, or by plates, strips or the like. 6 is
a peripheral groove to admit of the chain e engaging with the balls or spheres
mounted in the recesses or sockets 6'. The periphery of the wheel is recessed to
receive the pivots of the chain links as before.
g is a lock-nut or collar having a reverse thread to the wheel b for securing the
latter upon the hub a.
Although illustrated as applied to the hub of a velocipede wheel my invention is
by no means limited thereto. It may by obvious modifications be applied to the
gear wheel on the crank axle of a velocipede or elsewhere.
Obviously two or more gear wheels such as herein before described with reference
to Figure 1 might be arranged to gear or mesh together. Wheels as described
with reference to Figures 2, 3, 4 and 5 may gear with other wheels formed with
recesses on their peripheries similar to those shown at in the chain, but such
other wheels should be of such thickness as to pass freely between the plates,
collars, or side flanges d. In these instances the recesses b' in the wheels illustrated
may be dispensed with.
Having now particularly described and ascertained the nature of my said
invention and in what manner the same is to be performed, I wish it understood
that I am aware that the use of ball or spherical teeth in gear wheels is not new
and I do not claim broadly the use of such teeth, also that I am aware of the
Specification of Lock No. 4,708 of 1889, and that I do not claim anything
described and claimed therein, but what I do claim is :-
1. A chain or gear wheel having for teeth imprisoned balls or spheres, a
distance-piece or disc having milled-out portions forming beds for such balls or
spheres, and plates, collars, or side flanges serving to retain the said balls or
spheres, and permit them to move or roll within their imprisoning chambers
substantially as set forth.
2. A chain or gear wheel having for teeth balls or spheres so mounted that each
of the said balls or spheres will be capable of rolling within its chamber or socket
as the corresponding link of the driving chain or its equivalent leaves it, substan
tially as and for the purpose specified.
3. The improved chain or gear wheel and driving or pitch chain substantially as
described and illustrated with reference to either of the forms or modifications
shown in the accompanying drawing.