Improvements in the Driving Gear of Velocipedes.
Year: 1898

page_text: Date of Application, 13th Apr., 1898-Accepted, 29th Oct., 1898
COMPLETE SPECIFICATION.
Improvements in the Driving Gear of Velocipedes.
We, ISAAC PHILLIP PATTON, Machinist, and JAMES ARTHUR SEYBOLD, Merchant,
residing at 292, Kent Street, and 155,, Sparks Street, respectively, in the city of
Ottawa, in the Province of Ontario, and Dominion of Canada, 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 our invention is an improved gear for velocipedes to utilize the
power exercised by the pedal action more effectively and to increase the speed
obtainable therefrom.
Fig. 1 is a side elevation of a bicycle constructed with my improved driving
gear.
Fig. 2 is a corresponding view of the gear alone on a larger scale and the crank
in a different position.
Fig. 3 is a transverse section of the gear on line 3-3, Fig. 2, and showing the
crankshaft in longitudinal section with adjacent parts and the treadle arms falling
in the line of the plane of the section.
Fig. 4 is a transverse section of the crankshaft on line 4-4, Fig. 3 with the
adjacent parts of the frame seen from the inside and the gear behind it in elevation.
Fig. 5 is a diagram showing the relative position of the treadle arm and crank
with connecting link at regular intervals.
Fig. 6 is a longitudinal section of the link on line 6-6, Fig. 2, showing its
bearings in the treadle arm and crank or the connection of the latter with the
former.
The drawings and the following description refer to the construction of a bicycle.
A A¹ and A" are the front brace, seat post column and rear fork respectively.
Both the former two are forked transversely, (Fig. 3), with a somewhat wide
arch and preferably more on one side than on the other, to compensate for the
sprocket wheel and chain being placed within the forks, i.e. between their tines.
The ends of the tines, a and a¹, of these forks on each side and the end of the
corresponding bar of the rear fork are rigidly united (forged welded or brazed)
to form hubs, all (Fig. 4), projecting outwardly and each adapted to have a
somewhat large eye formed in it. B is the driving shaft or crank axle. It is
furnished with V grooved collars B₁ (called cones) which are carried in V grooved
bushings, CC, CC, (called cups) which are screwed into the eye in the hub a".
On that end of the axle on which, the sprocket wheel is placed the cone B¹ is
preferably formed integrally with the axle, while on the other side it is formed
separately and made a snug fit upon the axle. Each of the cups C C¹ and Cu C
consist of a pair of rings threaded outside to screw in the eye of the hub a" and
have their inner opposite corners, c, beveled to form a V groove, their inner
opposite faces, c³, clearing to allow room for adjustment and to take up wear and
their lips, c, clearing the axle and cone. Balls, b, are placed in the V groove
to form a ball bearing. To prevent displacement of said cups, a device is used

page_text: which is similar in all respects to that used in the excentric strap and which will
be described in connection therewith. A washer or disk, D, at the outer face of
the hub a, screwed into the eye, flushes up the latter with the former to make a
finish and also acts as a dust guard. A couple of screws, I), passing through
said washer and pressing against the outer part of the cup, prevents the washer
working loose. While on the non-driving side the two sections of the cup C C¹
are practically alike and with the clearance spaces' between themselves and between
the outer one and the washer D occupy and fill the whole depth of the eye in the
hub a", those on the sprocket side, CC, vary a little from each other and are
narrower, to accommodate a clutch, E. This consists of a flanged nut which
screws upon the axle and the edge of its circular barrel is screwed tight against
the adjacent cone B. The cup section C has, therefore, its lip, c, sufficiently
shortened to allow room for and clear. said barrel and its outer face clears the rear
of the flange, barrel and flange forming a rabbet in which the corner of said cup
section fits. It will be noted that the cup section C is stationary in the eye of
the hub while the clutch E rotates with the axle and cone and the former must
therefore clear both the latter. Said clutch is provided on its face (which sets flush
with the inner face of the hub a) with a series of lugs, e, which engage corre-
sponding circular slots in the sprocket wheel, F, which latter is mounted upon the
axle, being pressed against the face of the clutch E by a nut, F¹, screwed upon the
axle, with a washer, F, between them.
Upon the outwardly projecting part or lateral extension of each hub a" is
rigidly mounted and secured excentrically by screw threads as shown in Fig. 3,
a circular disk or excentric G and further secured adjustably to the hub all or
brace A by a bolt, such as G1, Fig. 2, (it will be seen, however, that the projecting
part of the hub a might be dispensed with and the excentric bolted to the hub
or adjacent parts). Said excentric is set to have its long axis (or geometric centre)
forward and upward of the axle B, approximately at a right angle to the direction
of the pedal action of the foot of the rider in its downward movement, which is
approximately parallel to the front brace A, both excentrics having the same
position. Upon each excentric is mounted an excentric strap, H, formed with an
extension, h, forming a crank arm and which, as a distinction from the axle crank,
will be termed the pedal arm, carrying the crank pin with the pedal in the usual
manner. The bearing surface between the excentric and the strap is formed
into a ball bearing, the face of the former having a V groove, g, carrying balls, 61,
For this purpose the sides adjacent to the face of the excentric disk are checked out
or rabbeted to receive the side flanges, h, of two rings, H', screwed into the rim of
the strap, one from each side and having their inner edges beveled to form a corres-
ponding groove between them, their remaining opposite faces, ", clearing, so
as to allow room for taking up wear. To prevent displacement of said rings, a
transverse key bed is provided in the rim H and a gib H", of soft brass or similar
material, inserted which is pressed down into the screw threads of the rings H¹
by a set screw H (Figs. 2 and 3) passing through said rim H. A similar
arrangement is used for securing the cups C, CCC in the eye of the hub a",
nothing but the set screw, C4, of which is visible in the drawings, Fig. 4.
II are the axle cranks set in a straight line in opposite directions. They are
secured in any well known manner upon the outer ends of the crank axie B (as
cotter bolts I) and each is connected with its adjacent treadle arm h by a link, I¹,
the connections being ball bearings, as shown in Fig. 6, formed on the pivot
bolts I and II with balls 611. The link is of such a length as to prevent the
treadle arm h and crank I at any point of their rotation falling into a straight
lime, or toc nearly approaching one. In other words, it is longer than the
difference between the end of the axle crank and the point of connection with the
pedal arm when both are taken to coincide with the long axis of the excentric.
The device operates as follows:
It will be observed that there are in this gear two centres of rotation, one the

page_text: crank axle and the other the fixed excentric, being a true circle mounted excen-
trically upon, but unconnected with the crank axle, and throwing the centre of
the excentric forward of the axle centre. The excentric centre (geometric centre)
of the excentric disk being the centre of rotation for the pedal arm and the pedal
-the point to which the propelling power is applied,--the leverage of the power
applied is constantly changing, as the distance of the pedal from the axle varies,
being greatest when the pedal arm coincides with and forms a continuation of the
longest axis of the excentric, which is about midway in the downstroke move-
ment when the greatest pressure can be exerted, and smallest when the pedal arm
coincides with the short axis of the excentric (exactly opposite the former posi-
tion) or about midway in the upstroke or return movement, when no propelling
power can be exerted at all, as illustrated in Fig. 5. The pedal is thus condi-
tioned to present the opportunity for the exertion of the greatest amount of pres
sure when the rider is in a condition to exert it. The centre of the circle which
the pedal describes not being the centre of rotation of the axle causes a peculiar
relative movement between the two, favored by the link connection which is found
in practice to be conducive to increased speed. There is the further advantage of
the foot having to move through a comparatively small circle for a long leverage.
The connection of the pedal arm with the crank by means of a link, instead of a
sliding connection as has been contrived by some inventors, has the advantage that
the amount of excentricity used cannot outrun the length of the pedal arm, as
is the case with a sliding connection. The friction of the excentric and strap, and
the connections of the link to the cranks are reduced to a minimum by the use of
ball bearings. Also the strain on the axle is equalized by the sprocket wheel being
placed between its bearings.
Having now particularly described and ascertained the nature of our inven-
tion and in what manner the same is to be performed, we declare that what we
claim is:
1. In a velocipede gear, the combination with the driving shaft or axle of the
rear fork and forked frame bars formed into hubs adapted to carry bearings for
the axle, bearings formed with said axle and in said hubs, a sprocket wheel rigidly
mounted upon said axle, a circular disk or excentric secured rigidly and adjust-
ably to the outside of each hub excentrically to the axle so that its longest axis
is forward of said axle and approximately at a right angle to the downward move-
ment of the treadle action of the foot of the rider, an excentric strap adapted
to rotate upon said disk or excentric and provided with an arm adapted to carry a
pedal, a crank mounted and secured upon each outer end of the axle and a link
connecting said crank arm with the pedal arm, substantially as set forth.
2. In a velocipede gear, the combination of a driving shaft or axle, crank arms
secured to the ends of said axle projecting from its bearings, a link pivoted to the
end of each of said cranks, a pivot bolt fixed in said link and turning on balls in
the crank, a pedal arm forming part of an excentric strap, a pivot pin in said arm
rotating upon balls and fixed in the other end of said link and an excentric
through which said axle projects and upon which said strap is mounted rotatively,
substantially as set forth.
3. In a velocipede gear, the combination with the driving shaft or axle, of the
rear fork and forked frame bars formed into hubs adapted to carry bearings for
said axle, bearings in the eyes of said hubs supporting said axle, a sprocket wheel
mounted and secured upon said axle between said bearings, an excentric secured
to the outer part of each hub having its geometric centre forward to and upward
of said axle, a strap mounted rotatively upon said excentric, balls between the
bearing surfaces of said excentric and strap, a pedal arm formed on said strap,
a pedal on said arm, a crank secured to each of said axles projecting through said
excentric and a link connecting the end of said crank to said pedal arm, sub-
stantially as set forth.

page_text: 4. In a velocipede gear, the combination of a circular disk secured to the frame
excentrically to the axle and the latter passing through the former, a V groove
in the face of said excentric, a strap or rim adapted to be mounted upon said
excentric and being internally screw threaded, a pair of rings externally screw
threaded and screwed into said rim and having their inner corners beveled off to
form a groove corresponding to the V groove in the excentric, a side flange on
each ring and a corresponding check or rabbet on each side of the disk rim
receiving said flange rotatively, balls in said V groove, a transverse key bed in
the outer rim, a gib of soft metal in said key bed and a set screw in said rim
adapted to press said gib into the threads of the rings and secure the same against
displacement, substantially as set forth.
5. In a velocipede gear, the combination with the driving shaft or axle, of the
front brace and seat column both formed into wide arched forks and the two tines
of the two pieces on each side formed with the corresponding bar of the rear fork
into a hub with lateral outward projection forming a continuation or extension
thereof and adapted to have a large eye for the reception of the axle and journal,
a journal within each of said eyes supporting said axle and a circular disk mounted
excentrically upon each of said lateral hub extensions, substantially as set forth.
6. In a velocipede gear, the combination with the driving shaft or axle, of the
rear fork and forked frame bars formed into hubs each having a large eye, V
grooved cones upon said axle within said eyes, V grooved cups screwed into said
eyes each consisting of two rings having their inner corners beveled and their
inner faces clearing, a clutch consisting of a flanged nut with circular barrel
screwed upon said axle with its barrel face tight against the inner face of one of
said cones and its face provided with lugs, a sprocket wheel mounted upon said
axle and having circular slots adapted to engage said lugs, and a nut screwed upon
said axle against the inner face of said sprocket wheel, substantially as set forth.
7. In a velocipede gear, the combination with the driving shaft or axle, of the
front brace and seat column both formed into wide arched forks each having one
tine further from the centre of the main piece than the other and the two tines
of the two pieces on each side formed with the corresponding bar of the rear fork
into a hub adapted to have a large eye for the reception of the axle journal therein,
bearings for said axle in said hub and a sprocket wheel mounted and secured upon
said axle between the two bearings, substantially as set forth.
8. In a velocipede gear, the combination with the driving shaft or axle, of the
rear fork and forked frame bars formed into hubs adapted to carry ball bearings
for said axle, ball bearings formed with grooved cones carrying balls upon the
axle and grooved cups in two sections screwed into said hubs, a transverse slot
or key bed in each hub, a gib of soft metal in said key bed and a set screw passing
through said hub and impinging upon said gib to secure said cup, substantially as
set forth.
1.
9. In a velocipede gear, the combination with the driving shaft of the rear fork
and forked frame bars formed into hubs adapted to carry ball bearings for said
axle, ball bearings formed with grooved cones carrying balls upon the axle and
grooved cups in two sections screwed into said hubs, washers screwed into said
hubs to flush and finish their outer faces and set screws passing through said
washers and binding on the cups, substantially as set forth.
10. In a velocipede gear, the combination with the driving shaft or axle,, of the
rear fork and forked frame bars formed into hubs adapted to carry bearings for
said axle, bearings in the eyes of said hubs supporting said axle, a sprocket
wheel mounted and secured upon said axle between said bearings, a circular disk
secured to the outer part of each hub excentrically to said axle and with its
long axis forward and upward, a V groove in the face of said disk or excentric,
a strap mounted rotatively upon balls in the groove of said excentric and consist-
ing of an internally threaded rim having externally threaded rings screwed into

page_text: it which form a V groove between them, a pedal arm formed on said rim adapted
to carry a treadle having a path of rotation concentric with said excentric disk
and excentric to said axle, substantially as set forth.
Dated this 12th day of February A.D. 1898.
JAMES ARTHUR SEYBOLD,
ISAAC PHILLIP PATTON,
--By-their Agent B. Harvey..