Improvements in or relating to Frames and Variable Throw Cranks for Cycles.
Year: 1896

page_text: Date of Application, 6th Nov., 1896-Accepted, 31st July, 1897
COMPLETE SPECIFICATION.
Improvements in or relating to Frames and Variable Throw Cranks
for Cycles.
HERBERT LUZERNE TODD, Electrician, 44 Upper Tollington Road, Holloway,
N. London and FREDERICK WILLIAM MCCLELLAN, Clerk Lincoln House, Asteys Row,
Cannonbury, N. London, 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 :-
This invention consists of a new method of obtaining power and stability to a
cycle. First to gain a leverage by a new form of crank. Second to have the said
crank form part of a combination which would combine the crank with a circular
rimmed hub. The rimmed hub to be of such dimensions as would admit of space
enough to allow the crank to be set eccentrically within the rim of the said hub for
the purpose of giving power to the thrust of the foot where needed and still keep
the foot in a perfect circular motion at each turn of the crank. The hub to be of
one piece of metal and to be so constructed that the tubes forming the frame of the
cycle can be fastened to bosses attached thereto. On each side of this circular hub
or rim is to be put a groove, both outside and inside, and as near the edge as may be
done consistently with the strength of the metal, for the purpose of guiding the
wheels attached to the crank lever bar. These wheels are to be with ball bearings
and so placed that any side strain upon the pedal will not move the wheels from the
groove. To avoid any tendency of the pins which sustain the said wheels from
turning or slipping from their normal position they are to be pinned or fastened by a
screw. The crank lever bar is to consist of a piece of metal with the pedal at one
end and two wheels on ball bearings fastened to the bar in such position as will allow
of the lever bar being turned in a circle from the common centre of the circular
rimmed hub, although the proper hub upon which the crank lever bar works is
eccentrically placed. The wheels upon the lever bar to revolve, one on the inside
and one on the outside of the said circular hub or rim. The crank lever bar or that
portion of it being contained within a sleeve piece which is fastened to the axle, is
to move on ball bearings backwards and forwards according to the distance from the
inner wheel on the lever bar to the centre of the hub where the axle is confined.
The sleeve piece which contains a part of the lever bar consists of two main pieces,"
one with a boss at the back to receive the axle and is constructed like a box without
a top or ends, one portion extending from the centre of the axle to the outer edge
of the circular rim when in line for the long thrust of the lever bar, but at the end-
of the lever bar most remote from the pedal, the other piece of the sleeve long
enough to reach across the rim from outside to outside and so constructed that it
will fit snugly in the opening of the first mentioned piece, for the length of that
piece, and the remaining length to be as wide and as deep as the piece which receives
the axle, this second piece to have only three sides, the open side being for the pins
of the inner and outer wheel to pass during the revolution of the crank. To avoid
friction between the long piece of the sleeve and the lever bar, ball bearings are to
be placed between the inner edge or side of the long piece of the sleeve and the
edge of the lever bar, the balls to run in semi-circular grooves cut in the sleeve

page_text: piece and lever bar respectively and kept in their proper position by pins or stops.
The circular rim forming the hub of a machine frame may be so constructed as to
allow of the sprocket wheel at the crank being placed inside the crank lever bar and
near the webbing of the casting in the said circular rim or hub for all ordinary.
purposes and could be placed upon the outside for very high gear or racing purposes.
In order that this invention may be used on machines already made the circular rim
can be in two pieces and fastened one on each side of the ordinary hub of the frame
and held in place by bolts or stays to the frame of the machine. To more fully
explain the nature of this invention reference is made to the accompanying drawings
in which like letters represent similar parts.
Figs. 1 and 2 are outline drawings showing a method of fastening the circular rim
to an ordinary frame. A. is a cast rim with radials D. from an eccentrically placed
hub and a flange K. The flange K. to have a series of holes through which the
screws M. are passed to fasten the rins together by stays to sliding pieces L. on the
tubes of the frame I. Attached to the axle C. is a sleeve E. which receives the lever
bar F. of the crank so that as the wheels G. set upon opposite sides of the rim A. in
being turned or pushed around will shorten the length of the crank from the centre
of the axle C. until the lever bar and sleeve are in the position shown in Fig. 2. the
total sweep of the pedal H. being a true circle from the common centre B. That
end of the sleeve E. which is next to the wheels G. is provided with rollers for the
lever bar to run between to lessen friction. The hub can be placed in any position
eccentrically so long as there is space between the inner surface of the rim A. and
the hub for the inner wheel G. to pass without touching the hub. The casting for
this form of a circular rimmed hub need not be confined to any particular pattern.
and the object of having the flange K. as long as designated is to enable the rim to
be fitted to any style of machine, and at the same time, to change the angle, with
the ground, of the crank lever bar when set at its longest length for the purpose of
altering the rise and fall of the foot.
Figs. 3 to 7 inclusive are outline drawings of this invention explanatory of the
construction of the hub to completion.
Fig. 3. shows the hub O. with two sets of radials D. and D' which are both attached
to the rim A. The rim A. is so constructed that the part from P. in the direction of
the arrow, to P is an opening wide enough to admit of the sprocket wheel being
inserted freely, and the hub Ö. is in two parts for the same purpose, hence the reason
for the two sets of radials. The radials D. are attached to one side of the hub,
or more accurately, are cast to one end of the hub 0. and one side of the circular
rim A. while the radials D' are cast to the other end of the hub O. and the other
side of the rim A. thus making a casting that will admit of the axle being passed
through the one part of the hub, throngh the sprocket wheel and then through the
other part of the hub ready for the cranks to be fastened thereto. The outer ends of
the hub O. to be turned out for the reception of ball bearings.
Fig. 4. shows a similar construction as Fig. 3, with the sprocket wheel attached.
Fig. 5. shows the sleeve piece K. attached to the axle Q. The axle Q. being square.
on each end to enter a similar shaped opening in the sleeve piece E. which is firmly
fastened by the screw R.
Fig. 6. shows the addition of the outer part of the sleeve, which is marked Ethe
crank lever bar F. and outer wheel G. which runs around the outer edge of the
circular rim A.
All of the Figs. 3. to 6. inclusive show the bosses I¹ which are cast to the circular
rim A. for the purpose of being brazed or fastened to the tubing or frame of the
cycle. These hosses are not to be confined to any particular position or size, but may
be so modified as to fit any style of frame.
Fig. 7. is a cross section of Fig. 6. on the dotted line f. g. and shows all of the
parts referred to in the other drawings.
Fig. 7 is the left side of the right sleeve piece E. piece Et lever bar F. wheels G.
as well as the ball bearings h. which run in the grooves k. and the pins or
stops m.

page_text: Fig. 7 is the under side of the right sleeve piece E. piece E¹ lever bar F.
wheels G. pins S. position of ball bearings and longitudinal grooves in piece E¹
grooves and stops for balls in lever bar F. and the boss to receive the axle.
Fig 7 is a cross section of the rear end of the sleeve pieces E and E showing the
grooves in the piece E and lever bar F for ball bearings.
Fig. 7" is a cross section of the front end of sleeve piece E¹ lever bar F. wheel G.
and pin S.
It will be seen by these drawings that as regards cost of construction that there
need be but little work expended upon the castings, for it is intended that all parts
except the crank lever bar and the pins and wheels will be cast, the opening in the
hub O. which is to receive the axle Q. is to be large enough to not touch the axle or
anything else except the ball bearings between the hub 0. and the sleeve piece E.
The sleeve pieco E. and the end of the hub 0. being fitted to the said ball
bearings. The sprocket wheel N. being placed upon a larger portion of the axle than
the ends that enter the sleeve piece E. and may he either round or square and should
be pinned with a screw as at T. to prevent slipping. When the crank lever bars F.
are in the position shown in Figs. 6. and 7. one is as much longer than the other as
twice the distance the centre of the hub O. is from the common centre of the circular
rim A. and the dotted lines u. v. and w. x. show the difference in length. The long
crank or . v. heing in the position where the foot has the most power and the short
crank or w. c. where the foot has the least power.
This form or combination of circular rim hub, sprocket wheel and crank is for the
purpose of confining all the parts into the smallest space so as to narrow the tread,
as well as to furnish the rider with a device for either speed or power, and one which
will not cause the foot to rise or fall as far as the ordinary crank.
Figs. 8 and 9. show a modified form of the circular rimmed hub for very high
gearing, in which the sprocket wheel N. has an opening Z. for the crank lever bar "
to slide in as the sprocket wheel is turned upon the centre C. and the sleeve piece E.
is provided with bosses 12 to which the sprocket wheel may be fastened by the screws a
and an extra pedal bar is attached to the crank lever bar F on the outside.
Having now particularly described and ascertained the nature of my said Inven-
tion and in what manner the same is to be perforined I declare that what I
claim is:
1. In a combined circular rimmed hub and crank for cycles, the combination of a
casting forming a cireular rim, a hub set eccentrically with radiating pieces attached
to the hub and rim, the circular rim to be supplied with bosses wherewith to attach
the frame, a sprocket wheel set in between the two parts of the hub and an opening
in the circular rim, a sleeve attached to the axle to allow the crank lever bar to slide
backwards and forwards within it, the said lever bar to have two wheels attached
thereto to run in a groove on each side of the circular rim, substantially as
described.
2. In a combined circular rimmed hub and crank for cycles, the combination of a
hub eccentrically placed within a circular rim, the said rim and hub connected
together by radials, the hub being in two parts for the insertion between of a sprocket
wheel, the said sprocket wheel to be fastened to an axle which is connected at each
end by a sleeve piece to receive the crank lever bar having attached thereto two
wheels that are to run in a groove upon each side of the circular rim substantially as
and for the purpose specified.
Dated this 2nd day of November 1896.
HERBERT LUZERNE TODD.
F. W. MCCLELLAN.