Improvements in and connected with the Crank Axles and Bottom Bearings of Bicycles.
Year: 1897

page_text: Date of Application, 25th Nov., 1897
Complete Specification Loft 25th Aug 1898--Accented 15th Oct. 1898
Date of Application, 25th Nov., 1897
Complete Specification Loft, 25th Aug 1898-- Accepted 15th Oct. 1898
PROVISIONAL SPECIFICATION.
Improvements in and connected with the Crank Axles and Bottom
Bearings of Bicycles.
I, MIKAEL PEDERSEN, of Kingsley House, Dursley, in the County of Gloucester,
Engineer, do hereby declare the nature of this invention to be as follows:-
My invention relates to the crank axles and bottom bearings of bicycles the
object of my invention being to provide an arrangement of parts which occupy
less space and require less adjustment than the parts of bearings as heretofore
constructed.
According to my invention the crank axle has secured to it or formed upon it
near one end a collar having in it a groove or channel forming a ball race, a portion
of the shank between this collar and the adjacent end of the spindle being made of
slightly larger diameter than this adjacent end of the spindle and screw-threaded
on a slight taper so that the chain wheel can be screwed tightly on to it. Pius or
keys are provided for preventing movement between the wheel and axle. Pro-
jecting from the face of the boss of this chain wheel on the side adjacent to the
said collar is a small flange or ring which serves to hold the anti-friction balls
in position when assembling the parts.
The race for the balls at the other end of the axle is formed in a kind of cap
which is adapted to be screwed up against a collar or abutment upon the shaft the
race portion of the said cap upon which the balls run being practically cylindrical.
The cap is provided with a projecting Hange or lip in the same manner as the
chain wheel so as to retain the balls in position when assembling the parts.
In the outer ends of the bottom bracket are inserted two cups with practically
cylindrical bearing surfaces for the balls the faces of which correspond with the
position of the races upon the axle.
In assembling the parts the chain wheel having been applied to the axle the
balls for the bearing on the chain wheel side are placed upon the said wheel
whilst in a horizontal position so that they lie against the projecting flange or
lip and then the parts whilst in this position are inserted into the bottom bracket
so that the balls of the bearing on the chain wheel side take their position in the
bearing. The frame with the axle thus placed in position is now turned over
and the balls for the bearing on the opposite sides are placed in the said cap which
is then placed upon the axle and screwed tightly up the distance between the
said cap and the face of the chain wheel being so accurately adjusted that when
the said cap is as tightly screwed up as possible the balls will be in proper
adjustment.
To permit of adjustment I advantageously arrange one or more washers of thin
packing material between the said cap and the collar against which it is screwed
so that when desired one or more of these thin washers can be removed to permit
of slightly decreasing the distance between the adjacent faces of the chain wheel
and the said cap. Or if desired the cylindrical portion of the cap may be ground
back the desired extent.

page_text: In practice the outer edges of the cups inserted into the bottom bracket enter
corresponding grooves formed in the adjacent faces of the chain wheel and the
cap for the purpose of excluding dust.
Dated the 25th day of November 1897.
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.
Improvements in and connected with the Crank Axles and Bottom
Bearings of Bicycles.
MIKAEL PEDERSEN, formerly of Kingsley House, now of Raglan House,
Dursley, in the County of Gloucester, 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:-
My invention relates to the crank axles and bottom bearings of bicycles the
object of my invention being to provide an arrangement of parts which occupy
less space and require less adjustment than the parts of bearings as heretofore
constructed.
In the accompanying drawing,
Figure 1 is an elevation of the crank axle; and,
Figure 2 is a sectional elevation shewing the axle in position with its bearings
in the bottom bracket and with a chain wheel upon it.
is the crank axle, is the chain wheel attached thereto and is the bottom
bracket.
According to my invention the crank axle a has secured to it or formed upon
it near one end a collar & having in it as shewn a groove or channel e forming a
ball race.
If desired, however, the surface of the said collar may be plain or
slightly conical similar to the cap hereinafter described on the other end of the
axle.
A portion of the spindle between the collar d and the adjacent end is made of
slightly larger diameter than the adjacent portions of the spindle and slightly
taper and on this taper portion a screw thread / is formed upon which the chain
wheel is placed, the tapering of the screw thread serving to ensure that, as the
wheel b is screwed home against the side of the collar d, it shall become firmly
wedged upon the said axle; pins or keys may be provided for preventing move-
ment between the said wheel and the axle a.
Upon the face of the boss of the chain wheel on the side adjacent to the collar d
is a small flange and outside this flange is a channel i, the purpose of both of
which will be hereinafter described.
The opposite end of the spindle to that upon which the chain wheel is fixed has
the portion of slightly less diameter than the central portion of the spindle so as
to form a shoulder and the portion of the spindle between the portion j and
the end is of still smaller diameter as clearly shewn in Figure 1.
The screw-threaded portion is adapted to have screwed on to it a cap m the
said cap having formed in it a race for the balls and being provided with a
flange h and groove i similar to those on the face of the boss of the wheel b.
The bottom bracket c has inserted into its ends the cups o, o in which the balls
run, the said cups having practically cylindrical bearing surfaces for the balls
so that the weight shall be carried by the balls in a vertical direction instead of
in an angular direction as is the case when the usual cups and cones are employed.
The outer edges of the said cups are adapted to enter the grooves i, i hereinbefore
referred to for the purpose of excluding dust from the bearings.

page_text: In assembling the parts the chain wheel b is first applied to the axle a, being
screwed tightly up against the collar d; the said axle is now held in a vertical
position with the flange h on the wheel b uppermost; the anti-friction balls are
then arranged around the collar d, the said flange h serving to retain the balls in
this position. The axle is now passed up through the bottom bracket so that the
balls are brought into the cup o. The frame with the axle therein is now turned
over and the balls for the bearing on the opposite side are placed in the cap m,
the said balls resting against the flange h on the said cap. This cap is now
screwed on to the portion of the axle and screwed tightly up against the
shoulder to bring the balls into the adjacent cup o. The distance between the
cap m and the face of the chain wheel should be so accurately adjusted that when
the said cap is as tightly screwed up as possible upon the axle, the balls will be
in proper adjustment.
In practice I find it advantageous to arrange one or more washers of thin packing
material between the said cap and the shoulder against which it is screwed, so
that, when desired, one or more of these thin, washers can be removed to permit of
slightly decreasing the distance between the adjacent faces of the chain wheel and
the said cap; or if desired the cylindrical portion of the cap which makes contact
with the collar k may be ground back to the desired extent.
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 I
claim is:-
1. The combination of a bottom bracket, cups inserted into the ends of the said
bracket and bored out to form races for the anti-friction balls, the portions of the
surface of the cups upon which the said balls run being cylindrical, a crank axle,
a collar fixed to the said axle near one end, a cap screwed tightly against a
shoulder on the said axle near the other end, the said collar and cap having in
them races designed to co-operate with the races in the said cups, and a chain
wheel mounted on a screw-threaded portion of the axle adjacent to the said collar
the said screw-threaded portion being made slightly tapering, substantially as
described.
2. The combination of a bottom bracket, cups inserted into the ends of the said
bracket and bored out to form races for the anti-friction balls, the portions of tha
surface of the cups upon which the said balls run being cylindrical, a crank axle,
a collar fixed to the said axle near one end, a cap screwed tightly on, to the said
axle near the other end, the said collar and cap having in them races designed to
co-operate with the races in the said cups, and a screw threaded portion upon the
said axle adjacent to the said collar the said screw threaded portion being made
slightly tapering and adapted to carry a chain wheel, substantially as described.
3. The manufacture and use of crank axles and bottom bearings for cycles
substantially as herein before described and illustrated in the accompanying
drawing.
1
_1008
G. F. REDFERN & Co.,
4, South Street, Finsbury, London, Agents for the Applicant.