Improvements relating to Driving Gear for Velocipedes.
Year: 1898

page_text: Date of Application, 4th Mar., 1898-Accepted, 7th May, 1898
COMPLETE SPECIFICATION.
Improvements relating to Driving Gear for Velocipedes.
We, JULIUS ALEXANDER NICOLAJ RASMUSSEN, of Tojhuset, Armorer, and
CHARLES BENTON HART RASMUSSEN, of 2, Kalkbranderivej, Machine Constructor,
both in Copenhagen, in the Kingdom of Denmark, do hereby declare the nature
of this invention and in what manner the same is to be performed, to be particu-
larly described and ascertained in and by the following statement:―
It is well known that in ordinary cycles provided with a chain the latter
forms an elastic connection between the crank-axle and the axle of the rear wheel.
Being placed on the ends of the axles in question, it will when suddenly tightened
draw the hind frame of the cycle towards the crank axle so that when riding on
rough roads, in starting, or in stopping the cycle the rear part of the frame is
constantly vibrating.
Chainless cycles, notwithstanding their obvious advantages in other respects
have the drawback that they do not possess the above mentioned elastic connection.
The pedalling will consequently be hard, all roughnesses of the road will be felt
through the pedals by the rider, and the different parts of the driving gear will
be violently strained.
The object of the present invention is to obviate this drawback of the chainless
cycles by giving them an elastic connection in the shape of a block of india rubber,
a flat or a spiral spring, one end of which being fixed to the driving wheel, and the
other end to the crank axle; or in the shape of a spring fixed to the driving wheel
itself.
The accompanying drawing shows as an example different ways of carrying out
the invention.
Figure 1 shows a portion of the driving gear wheel provided with one form of
the elastic connection.
Figure 2 a section on the line A-B Figure 1.
Figure 3 shows another form of construction, while
Figures 4 and 5 illustrates a third form in side and front elevation respectively.
In the first example (Figures 1 and 2) the driving wheel a revolves on the axle
it being as shown fixed on to a tempered steel tube b, which in a suitable manner
is secured on the axle c in the longitudinal direction. A double lever c¹ placed on
the axle limits the motion by catching into a recess a¹ in the wheel a. This
double lever is kept in position of rest by a forked spring e which is hooked on to
the driving wheel by a tenon e' with a broader head.
e.
The pedals being acted upon, the long arm of the lever c¹ will press upon one
prong of the forked spring straining it, while the short arm of the lever strains the
other prong of spring The straining will increase till it has sufficient force to
move the gear. During even riding the straining will be constant but by riding
up and down steep hills it will change and thus offer the elasticity desired.
Owing to the double action of the arm on the spring e the resistance of the latter
increases so that its highest strain is reached only now and then but never sur-
passed, as the arm c¹ touches one side of the recess a and thus directly rotates the
wheel.

page_text: When the pedals are acted upon in the reverse direction the double arm c¹ will
press the opposite prong of spring e but the effect will be as above described.
In the construction shown in Figure 3 the driving wheel is provided with two
hollows or recesses f, f, into which india rubber blocks g, g, or other elastic bodies
are placed which are acted upon by an arm h fixed on the crank axle c, while the
moving of this arm will be limited by a recess k in the driving wheel a.
In Figures 4 and 5 a third construction is shown, in which the driving wheel a
has an arm upon which is fixed one end of a flat or a spiral spring p by means of
a screw-bolt m, the other end of the spring being fixed in a similar way by means
of a screw-bolt o to an arm n protruding from the crank axle c.
The working will easily be understood from the description hereinbefore given;
the mobility of axle c may for instance be limited by an arm catching into a recess
of the wheel which is not shown on the drawing.
Having now particularly described and ascertained the nature of our said
invention and in what manner the same is to be performed, we declare that what
we claim is:-
1. An arrangement for producing elastic pedalling in chainless cycles, in which
the motive power is transmitted by means of a cog-wheel, consisting of an elastic
connection inserted in the driving gear in the shape of a block of india-rubber,
a spring or a similar body, which by attaining different degrees of tension may
neutralize sudden changes in the resistance to the motion, substantially as described.
2. An elastic connection as referred to in Claim 1 consisting of a spring e fixed
to the driving wheel a (which is turnable only to a certain extent round the crank
axle c), the said spring e being straightened by an arm c¹ fixed to the crank axle
substantially as described.
g
3. An elastic connection as referred to in Claim 1 consisting of two india-rubber
blacks placed in two hollows or recesses f fixed to the driving wheel a, the blocks
being acted upon by an arm h protruding from the crank axle which is rotatable
only to a certain extent in relation to the driving wheel, substantially as described.
4. An elastic connection as referred to in Claim I consisting of a flat or a spiral
spring p, the ends of which are fixed to two arms and n on the driving wheel a
and the crank axle e respectively, substantially as described.
1 1
ALL
Sh 1000
HASELTINE, LAKE & Co.,
45, Southampton Buildings, London, W.C., Agents for the Applicants.