An Improved Method of Attaching Chain-wheel on Orank-axle of Oyoles or Velocipedes, rendering same Easily Detachable.
Year: 1893

page_text: Date of Application, 1st Feb., 1893
Complete Specification Left, 4th Oct., 1893-Accepted, 4th Nov., 1893
PROVISIONAL SPECIFICATION. .
An Improved Method of Attaching Chain-wheel on Orank-axle of
Oyoles or Velocipedes, rendering same Easily Detachable.
I, JOHN LACEY ROLLINGS No. 2 Brook's Court, St. Mary's Street, Stamford,
Lincolnshire Cycle Maker, do hereby declare the nature of this invention to be as
follows:-
It being desired to fasten chain-wheel upon the right-hand and of crank-axle, at
the proper distance from that end I turn out a recess about one sixteenth of an
inch deep, and about one eighth of an inch wide. I then make a turned and bored
collar, the thickness of which fits the width, and the bore of which fits the reduced
dinmeter of axle in the before-mentioned recess, this collar being about 1 inch
outside diametor, and divided into two portions across its diametral line.
The portion of axle to the right of recess is then chased in the lathe with
a suitably fine left-hand screw thread, and the chain-wheel is bored and screwed to
match, with a recess turned and sunk in face of boss of maid wheel, of a diameter
to exactly fit outer diameter of divided collar, and of a depth equal to its
thickness.
The two halves of the divided collar being placed into the recess in axle, the
chain wheel is screwed on to the axle until the collar is imbedded tightly in recess,
in face of wheel, which makes it impossible for the halves of collar to rise out of
the reduced portion or recess in axle.
The portion of screwed axle which projects through wheel to the right is then
slightly reduced or turned down to the bottom of the left-hand thread thereou and
is then screwed with suitable right-hand thread upon which a nut fits, and being
screwed up tight to side of boss of wheel opposito divided collar effectually locks
the whole in place.
The remaining portion of axlo to right of nut is then further reduced to take
crank in the usual way.
Should it be desired to fasten wheel on left-hand end of axle the threads would
be reversed the thread on axle and in wheel being right-handed and the lock-nut
left-handed.
Dated this 80th day of January 1893.
COMPLETE SPECIFICATION.
An Improved Method of Attaching Chain-wheel on Orank-axle of
Oycles or Velocipedes, rendering same Easily Detachable.
I, JOHN LACEY ROLLINGS, formerly of No. 2 Brook's Court, Saint Mary's
Street, Stamford, Lincolnshire, but now of No. 9 Saint John's Street, Stamford
Lincolnshire, Cycle Maker, 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 velocipedes driven through pedals, cranks and chain
gearing and consists in the hereinafter described method of attaching the wheel
on the crank axle in such a way as to render the same easily detachable therefrom.
In order that my invention may be well understood 1 append drawings which
show the general form and arrangement of the parts of my invention, but modi-
fications can be made without departing from the spirit of my invention. In the
drawings similar numerals refer to similar parts.

page_text: Figure 1 represents partly in elevation and partly in section'a pedal crank axle
bearing bracket of the kind commonly known as a "Humber or barrel" bracket
for a rear driving safety bicycle, holding a pedal crank axle on which a chain
wheel is attached according to my invention.
Figure 2 represents a modification of some of the parts shown in Figure 1, and
Figure III represents in elevation the divided collar shown in section in Figures I
and II.
It being desired to fasten the chain wheel 2 upon the right hand end of the
orank axle 4;—at a convenient distance from the extremity of the axle,-I turn
out a recess 6 which may measure about one sixteenth of an inch deep and about one
eighth of an inch wide or other suitable dimensions. I then make a turned and
bored collar 7, the thickness of which fits the width and the bore of which fits the
reduced diameter of the axle 4.in the recess 6. This collar may be of about one and
one eighth inch or other suitable outside diameter (the same being greater than the
diameter of the said end of the axle 4) and the said collar is divided into two
portions across its diametral line. The divided collar 7 must be of sufficient size
and strength to bear the strain to which it is subjected in attaching the chain
wheel 2, to the axle, 4, and the recess 6, must be of sufficient sizo to hold the
collar 7 securely, but the recess 6 should not be so large as to unduly reduce the
strength of the axle 4.
The portion of the axle 4 to the right of the recess 6 is then chased in the lathe
or otherwise provided with a suitably fine left hand screw throad 3 and the chain
wheel 2 is bored and screwed internally to match the loft hand thread on the axle.
The chain wheel is further provided with a circular concentric recess 8 turned and
sunk in the left face of the boss of the said wheel, such recess being of a diameter
to exactly fit the outer diameter of the divided collar 7, and of a depth equal or
'approximately equal to the thickness of the said collar.
"
In order that the recess 8 may well and truly fit the divided collar it is desirable
that the two parts of the said collar should together equal a whole or single piece
collar of practically complete circular form. To attain this desiratum I prefer to
make the divided collar of two pieces of straight flat bar steel or other suitable
material and suitable dimensions. 1 lightly braze the two pieces together by their
straight edges and turn and bore them to the form and dimensions required.
When finished I knock the two (preferably equal) pieces apart. The two
pieces, thus mado together, equal a collar of practically complete circular form.
If a collar made from a single piece of metal were sawn in two, the two pieces
would together equal a collar of a form amounting to less than a complete cirole
by the quantity of metal subtracted in the process of sawing. But I do not confine
myself to the above described method of making the divided collar as it may be
made in other ways with a like result.
The two halves of the divided collar 7 being placed in the recess 6 in the axle 4,
the chain wheel 2 is screwed on to the axle until stopped by the collar and which
cullar is then embedded tightly in the recess 8 in the face of the wheel, which
inukes it impossible for the halves of the collar to rise out of the reduced portion or
recess 6 in the axle. The right hand circumferential edge of the collar 7. is
preferably slightly rounded off so that the collar may readily become embedded in
the recess 8. If desired a double thread such as shown in at 3 in Figure Il or a
triple or any other_convenient multiple thread may be used instead of the single
thread shown at 3 Figure 1. Where a double triple or other such multiple thread
is used, the chain wheel may be more quickly screwed on to and off from the axle
than where a single thread is used and tho wheel is more readily removed owing to
the greater inclination of the screw thread not allowing the parts to be jammed up
so tight.
The portion of the axle which projects through the wheel 2 to the right is slightly
reduced or turned down to a diameter measuring at most not more than that of the
bottom of the left hand thread on the axle, and this portion of the axle is then
screwed with a suitable right hand thread 5. A suitable nut 0 is fitted upon this

page_text: right hand thread and being screwed up tight to the side of the boss 10 of the
wheel 2 opposite the divided collar 7, effectually looks the whole in place.. I prefer
to arrange the parts so that when the wheel 2 is screwed up tight against the
collar 7, the right hand side of the boss slightly overlaps the right hand thread 5
as shown in the drawing. If desired (with the object of reducing the "width of
tread," that is; the horizontal distance between the pedals of the velocipedes, or
for other reasons) a recess 11 Figure 11 of suitable dimensions may be made in the
right face of the boss 10 of the wheel and the length of the portion of the axle
provided with a left hand thread reduced so that it does not project into the said
recess 11 when the wheel is screwed up tight into position; the right hand thread 5
is carried a distance to the left corresponding to the depth of the recess 11 and the
nut is screwed into the rocess 11. In this case I prefer to make the nut 9 round
and provide it with two recesses 12, enabling it to be turned with a suitable
pronged wrench; the thickness of the nut preferably equals the depth of the recess
so that the split collar 7, and the nut 9 both lie flush with the two faces respectively
of the boss of the wheel 2. Where a recess 11 is used the tread may be reduced,
so far as this invention is concerned, by the depth of the recess if the nut 9 be
buried therein, but the depth of the recess and the thickness of the nut 9 may be
varied within any convenient and suitable limits, so that the outer surface of the
nut may lie to the left or right of the right face of the boss of the chain wheel.
The remaining purtion of the axle to the right of the nut is then further reduced
to take the crank in the usual way.
Should it be desired to fasten the wheel 2 on the left hand end of the axle 4 the
screw threads would be reversed, the thread 3 on the axle and in the wheel being
right handed and the thread 5 on the axle and in the lock nut 9 being left handed.
The object of sotting the screw threads in the several directions above mentioned
is to cause the power exerted on the chain wheel and crank axle in propelling the
machine forward to tend to sorow the chain wheel tighter up to the divided collar
on the axle the screw thread on which the nut is fitted is set in the opposite
direction to the scrow thread on which the chain wheel is fitted in order that the
nut may the more securely look the wheel in position aud prevent its unscrewing.
To detach the chain wheel 2 from the crank axle 4, the crank is first detached
from the end of the said axle. The nut 9 is then unscrewed and removed. The
wheel may then be unscrewed and detached. By removing the parts of the collar 7
from the recess 6, the end of the axle 4 is left clear for the cup or disc 13 to be
passed along and off it, which could not be done if the collar 7 were a fixture, nor
could the disc 13 be then passed along into its position in the first instance. Hence
my invention is specially applicable to "Humber" or "barrel" brackets, though it
is also applicable to other kinds of brackets and to other kinds of velocipedes than
the rear driving safety bicycle.
I am aware that chain wheels have already been attached to crank axles so that
they may be readily detached therefrom, by providing the said crank nxles with
external screw threads and collars and by screwing the said chain wheels up to the
said collars on the said axles but arranged in the opposite direction to the first
threads thereon and I do not broadly claim such arrangement as my invention bnt
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. In a cycle or velocipede, the combination with a crank axle, of a recess
formed in such axle, and of a divided collar fitting into and projecting out of such
recess substantially as and for the purpose herein described.
2. In a cycle or velocipede the combination with a chain wheel, of a circular
concentric recess formed in one face of the boss of the said chain wheel and of a
divided collar adapted to be fitted into such recess, substantially as and for the
purpose herein described.
3. In a cycle or velocipede the combination with a crank axle, having an

page_text: external screw thread or screw threads and chain wheel provided with an internally
screw threaded hole in the boss thereof adapting it (the said wheel) to be screwed
on to the said axle, and a lock nut adapted to bo sorewed on to the said axle and
abut against the boss of the said chain wheel, of a recess formed in such axle, of a
divided collar fitting into and projecting out of such recess and adapted to act as a
stop for the chain wheel to be screwed up to, and of another recess in one face of
the boss of the said chain wheel adapted to receive the said collar substantially as
and for the purpose herein described.
4. In a cycle or velocipede driven through chain gearing, attaching the chain
wheel to the crank axle by providing the said axle with a recess, and an external
screw thread adjacent to such recess, forming a divided circular collar and inserting
such collar in the said recess in the axle so that it, the collar, projects beyond the
surface of the said axle, providing the boss of tho said chain wheel with an
internally screw threaded hole adapting the said wheel to be screwed on to the
said axle (the said screw threads being directed so that the power applied to the
wheel and axle tends to screw the wheel tighter ou to the said axle against the said
collar) and providing the said boss with a circular concentric recess in one end
adapted to receive the said collar; and providing the said axle with a second
screw thread adjacent to but directed in the opposite direction to the first screw
thread and screwing a nut on to such second scrow thread so that it abuts against
the boss of the said chain wheel and locks the parts in position substantially as and
for the purpose set forth.
5. In a cycle or velocipede, the improved constructions, combinations and
arrangements of parts constituting an improved method of attaching the chain
wheel on the crank axle so as to render the same easily detachable therefrom,
substantially as herein described and illustrated.
Dated this 2nd day of October 1893.
WILLIAM BESTWICK MAXFIELD,
Registered Patent Agent,
19, Bowling Green Street, Leicester, Applicant's Agent.