Improvements in and connected with Pedals and Cranks for Bicycles and other Velocipedes.
Year: 1899

page_text: PROVISIONAL SPECIFICATION.
Improvements in and connected with Pedals and Cranks for Bicycles
and other Velocipedes.
I, WILLIAM JOSEPH RYMER WATSON, of No. 16, Holborn Viaduct, in the City
of London, Stockbroker, do hereby declare the nature of this invention to be as
follows:
My invention relates to improvements in and connected with pedals and cranks
for bicycles and other velocipedes whereby I am enabled to give a throw of
varying length to the pedal at different periods during one revolution of the
crank shaft.
According to my invention I key or otherwise attach to each of the crank
pins an eccentric barrel either solid or of a skeleton form or I provide two eccen-
tric discs or the like adapted to receive a row or rows of balls or rollers and I
mount the pedal so as to cause it to revolve on the balls or rollers surrounding
the eccentric discs in any convenient manner and preferably so as to permit of
the adjustment of these bearings and to prevent dust or dirt entering the bearings.
By my invention I am enabled to obtain practically the same result with a
crank having a throw of say six inches as is now obtained with a crank with, say,
a throw of seven inches.
1000
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.
Improvements in and connected with Pedals and Cranks for Bicycles
and other Velocipedes.
I, WILLIAM JOSEPH RYMER WATSON, of No. 16, Holborn Viaduct, in the City
of London, Stockbroker, do hereby declare the nature of this invention and in
what manner the same is to be performed to be particularly described and ascer-
tained in and by the following statement:
-
My invention relates to improvements in and connected with pedals and cranks
for bicycles and other velocipedes whereby I am enabled to give a throw of
varying length to that point on the pedal where the power of the rider is exerted
at different periods during one revolution of the crank shaft.
Figure 1 of the accompanying sheet of drawings represents in elevation a
bicycle crank fitted with a pedal made according to my invention and
Figure 2 is a plan thereof partly in section
Figure 3 is a sectional plan of a modified form

page_text: or
Figure 4 is a similar view of another modification and
Figure 5 is a similar view of yet another modification.
According to my invention and referring more particularly to Figures 1 and 2
I key or otherwise attach to each of the crank pins, of which only one is shown
and marked A, an eccentric barrel or extension of a solid or skeleton form. In
the present instance, this barrel is shown as consisting of two discs B and C
of which the disc B is mounted eccentrically on the crank pin A
and provided with a pedal pin D which is keyed screwed into
otherwise attached to the said ise 13. The disc C is mounted on the
pedal pin and preferably it is screwed thereon being locked or jammed
in position by means of a nut E and further there is a washer F having a flat
thereon, the end of the pedal pin D being correspondingly formed so as to pre-
vent the washer from turning and there may also be a lock nut to jam the nut E.
It is evident however that if desired other means of locking the disc C in position
on the pedal pin D may be employed. The barrel G of the pedal is mounted
on the two discs B and C so as to permit of its free revolution and preferably
the rows of balls H and H as shown are interposed in suitable ball races to
reduce friction as much as possible. The barrel G is provided with means for
affording a foothold for the rider such as plates I and I¹ with jagged edges to give
a grip as is usual in pedals of the rat-trap type and with the ordinary horns K
and K to prevent the foot of the rider from slipping sideways.
In the construction shown in Figure 3 the crank pin A³ is continued right
through the second disc C3 while both discs are provided with a keyway and the
crank pin is provided with a key or feather A which fits in the said keyways
it is naturally of importance that the discs B3 and C3 should not be at all loose
on the crank pin A3 and for this reason any additional devices such as screws L
and M may be employed in the discs B3 and C³ to prevent any movement on
the crank pin. In this instance the strain is not so great on the pedal pin and
consequently it is shown of smaller diameter than in the construction shown in
Figures 1 and 2.
The construction shown in Figure 4 differs only slightly from that shown in
Figures 1 and 2 in that the disc or cone C is of smaller diameter than the disc C
Figure 2 my reason for this being that it is not essential that the outer disc be
as large in diameter as that of the inner disc B.
The modification shown in Figure 5 is somewhat similar to that shown in
Figure 3 except that the pedal pin is entirely dispensed with and the discs B5
and C fit tightly on the crank pin A5 being prevented from turning thereon by
means of feather ways into which the feather A6 fits. If desired the disc B
may be a fixture on the crank pin A³. There is a nut or as shown a nut E and
a lock nut E to hold the disc C the right distance apart from the disc B³.
One feature of my invention is that I am enabled to obtain practically the
same result with a crank having a throw of say six inches, as is now obtained
with a crank with, say a throw of seven inches. It is evident that the effect
of mounting an ordinary pedal at a point beyond the axis of the crank pin does
not in itself produce any greater advantage than would be obtained by using a
longer crank but by my invention I obtain not only a longer crank without
interfering with any part of an existing machine (excepting the removal of the
ordinary pedals) but in practice I find that I apply the power at varying distances
from the axis of the crank axle owing to the different angles which the pedal
assumes during its revolution and consequently the path described by an imagi-
nary point under the ball of the rider's foot where he applies power to the pedal
does not produce a true circle but a figure of a pronounced elongated or oval
shape due to the combination of the revolution of the pedal round the axis of
the crank axle and the variations of angle of the pedal to the horizontal. The
result obtained is that the power of the rider is expended more usefully at cer-
tain positions of the pedal than is possible with cranks and the pedals of ordinary
construction both when pedalling and back pedalling.

page_text: 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. An attachment for the crank of a bicycle or other velocipede consisting
of a barrel or extension mounted eccentrically on the crank pin of the said
bicycle and having a pedal mounted thereon substantially as set forth.
2. An attachment for the crank of a bicycle or other velocipede consisting
of a crank pin, two discs mounted eccentrically thereon, a barrel adapted to
revolve on said discs and means for ensuring a foothold for the rider on the said
barrel substantially as described and shown.
3. The constructions of pedal attachments shown on the drawings.
Wat dox
1800
JENSEN & SON,
77, Chancery Lane, London, W.C., Patent Agents.