Improvements in Velocipede Driving Gear.
Year: 1894

page_text: Date of Application. 16th Nov., .1894
Complete Specification Left, 16th Aug., 1895-Accepted, 12th Oct., 1895;
THUYLIUNAL DE MUITIVATION.
Improvements in Velocipede Driving Gear.
I GERALD BARKER of Westoe, South Shields, in the County of Durham,
Engineer, do hereby declare the nature of this invention to be as follows:-
This invention relates to the crank-driving mechanism of velocipedes.
11
The main object is to increase the speed, or render the propulsion easier by
applying the pressure upon the pedals to greater advantage.
The invention consists essentially in providing mechanism for causing the pedals
to travel around the main crank spindle in an excentric or somewhat excentric
path or course. When descending the pedals are at an increased distance from the
When the
crank spindle, and power is therefore applied to greater advantage.
pedals are ascending, they are at a reduced distance from the crank spindle. By
this means the advantage of a long crank-throw is obtained without the fatigue
consequent upon the feet having to travel round the spindle at a larger radius.
In carrying my invention into practice I cause the crank spindle to pass through
the centre of the driving wheel or wheels, and the said spindle is attached
directly thereto, or power is conveyed to the said wheel or wheels by means of
suitable gear.
If desired the crank spindle is mounted in separate bearings,
and power is conveyed to the driving wheel or wheels by endless chains, gear
wheels or the like.
The excentric or somewhat excentric course or path of the pedals is obtained
in any of the following or equivalent ways.
(a.) By sliding pedal pins working in long-slotted cranks or cranks with
suitable slides, the positions of the pedal pins in such slots being controlled
by radial arms from a fixed centre some little distance in front of the crank
spindle bearings.
(b.) By sliding pedal pins working in long slotted cranks, or cranks with
suitable slides, the positions of the pedal pins in such slots being controlled by
excentric guides or paths fixed to the framework of the machine.
(c.) By means of secondary cranks attached to spindles mounted in bearings
at the outer ends of radial arms working freely on the main crank spindle.
Planet-wheels are keyed or otherwise fixed on the secondary crank spindles,
and endless chains or bands pass over each of these planet wheels and over
stationary sun-wheels fixed to the framework of the machine. The sun-wheels
and planet wheels must be of equal diameters. Intermediate wheels may be
substituted for chains between the sun and planet wheels. Either of the above
arrangements will maintain the secondary cranks in horizontal positions at all
points of revolution, and the secondary cranks always project forward. The
forward ends of the secondary cranks govern or control the positions of the
pedal pins in the slots or slides of the main cranks.
(d.) A somewhat excentric course or path may be insured for the pedals and
increased leverage obtained by mounting short secondary cranks and spindles in
bearings on the outer ends of the main cranks, the pedal pins being fixed to the
outer ends of the secondary cranks. Toothed planet wheels, keyed or otherwise
attached to the secondary crank spindles, engage direct with stationary toothed
sunwheels of the same diameter as the planet wheels.
The centres of the various sunwheels referred to in the above schemes, must
coincide with the centre line of the main crank spindle. The sunwheels are.

page_text: preferably bored out so that the main crank spindle would pass through them
without touching. All the sunwheels are stationary.
Discs may be used instead of cranks.
J. JOHNSON,
Agent.
GERALD BARKER of Westoe, South Shields in the County of Durham,
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:-
This invention relates to the crank-driving-gear of velocipedes.
The main object is to increase the speed, and render the propulsion easier by
applying the pressure upon the pedals to greater advantage.
The invention consists essentially in providing mechanism for causing the pedals
to travel around the main crank spindle in a somewhat excentric or elliptical path
or course. When descending, the pedals are at an increased distance from the
crank spindle, and power is therefore applied to greater advantage. When the
pedals are ascending, they are at a reduced distance from the crank-spindle. By
the above means the advantage of a long crank throw is obtained without the
fatigue consequent upon the feet having to travel round the spindle at a larger
radius.
In carrying my invention into practice I cause the crank spindle to pass through
the centre of the driving wheel or wheels and the said spindle is attached directly
thereto, or power is conveyed to the said wheels by suitable gear. If desired,
the crank spindle is mounted in separate bearings and power is conveyed to the
driving wheel or wheels by an endless chain or chains, gear wheels or the like, and
the somewhat excentric or elliptical course or path of the pedals is obtained as
follows:-
Secondary cranks, crank wheels, or crank discs have their spindles mounted in
bearings at the outer ends of the main cranks, crank wheels, or crank discs, the
pedal pins being fixed to the outer ends of the secondary cranks, crank wheels, or
crank discs. Toothed planet wheels keyed or otherwise attached to the secondary
crank spindles engage directly with stationary toothed sun wheels of the same
diameter as the planet wheels and concentric with the main crank spindle.
The centres of the sunwheels must coincide with the centre line or axis of the
main crank spindle. The sunwheels are preferably bored out so that the main
crank spindle passes through them without touching in order to avoid friction and
provide room for the crank spindle bearings.
DESCRIPTION OF THE DRAWINGS.
Fig. 1 is an elevation and Fig. 2 is a plan of driving gear constructed in accordance
with my invention.
a is part of the framework of a velocipede. 6 is the main crank spindle. c is
a chain wheel secured to the crank spindle b. Two arms c¹ of the said wheel
together with bow or divided rim ca form the main crank at one end of the
spindle, being the main crank at the other end. d are secondary crank spindles
carried in bearings in the bows c². e are the secondary cranks. f are the pedal
pins and pedals. g are toothed planet wheels secured to the secondary crank
spindles and gearing with stationary sunwheels secured by set screws or
other suitable devices i to the framework a. The sunwheels are bored out to

page_text: receive the bearings for the main crank spindle b. The sunwheel may consist of
a toothed ring attached to the frame by set screws or the like passing through
slots in the said ring, so as to allow the angle of leverage to be readily adjusted.
If the slots are symmetrically placed, the sun ring may be turned partly round its
axis from time to time to ensure even wear. Planet wheels may be similarly
constructed.
Fig. 3 is a modification of gear similar to that described in Figures 1 and 2
with the exception that the bow or divided rim or end is dispensed with and that
the secondary crank spindles d are carried in a bearing or bearings in bosses c³ on
the arms of the chain wheel c or crank c*.
When the main crank spindle 6 passes through the centre of the driving wheel
and is attached or geared thereto, a crank similar to ct for either Figs. 1 or 3 is
used instead of the chain wheel.
Fig. 4 is an elevation and Fig. 5 is a plan showing a modification of driving gear
in which crank-arms c¹ secured to the main crank spindle b carry fixed crank pins
or secondary crank spindles d, around which the secondary cranks e and planet
wheels g rotate. When chain wheels are used, the crank arms c¹ are secured to
the chain wheels c by set screws or other suitable devices; as shown.
Fig. 6 is an elevation of gear similar to that described under Figures 4 and 5
with a large chain wheel.
Fig. 7 is a diagram showing the position of the main crank spindle b,
secondary crank spindles d and pedal pins and pedals at various points during a
revolution, the arrow showing the direction of motion. On reference to the above
diagram it will be seen that when applying power the pedals travel quickly down
through an increased distance as compared with pedals on a main crank pin, and
that during the remainder of the revolution the pedals pass upwards through a
decreased distance. If the secondary cranks are, as I prefer, one quarter of the length
of the main crank the pedals travel fifty per cent. faster and further during a portion
of the down stroke, the increased leverage being therefore twice that due to the
excentricity. During the down stroke it will be seen that the pedals overtake
and pass the main crank end but that the latter reverses its lead during the
up stroke.
By engaging any particular teeth of the sun and planet wheels and by varying
the position of the sun and planet wheels when slotted connections are used, the
angle of greatest leverage may be varied so as to adjust such angle to the best
advantage according to the position of the saddle. The sun-wheels may be made
to form part of the framework of the velocipede and so give increased stiffness
thereto.
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 1
claim is :-
First. Velocipede driving gear constructed substantially as and for the purpose
set forth.
Second. The combination of a main crank spindle and crauk, crank discs, or
crank wheels, with secondary cranks, crank discs or crank wheels, and sun and
planet wheels substantially as and for the purpose set forth.
Tared the tach day mu
J. JOHNSON,
4 Clayton Square, Liverpool, Agent.
J. JOHNSON,
4 Clayton Square, Liverpool, Agent.