Improvements in and relating to Chain-adjusting Devices for Velocipedes.
Year: 1897

page_text: Date of Application, 4th Oct., 1897
Complete Specification Left, 16th Apr., 1898-Accepted, 11th June, 1898
TIONAL SPECIFICATION.
Improvements in and relating to Chain-adjusting Devices for
Velocipedes.
1, GEORGE PILKINGTON MILLS, of "The Woodlands," Beeston, in the County of
Notts, Engineer, do hereby declare the nature of this invention to be as
follows:-
This invention relates to an improved chain adjusting device for chain driven
cycles, and it has for its object obtaining a parallel adjustment with the slotted
back forks at present used.
According to this invention a washer of any suitable shape is rigidly fixed by
keying or otherwise near each end of the axle. In each of these washers is a
radial slot adapted to engage with a pin or peg fixed to or carried by one of the
jaws of the back forks, the construction being such as to allow the necessary
movement of the axle in the said jaws.
To adjust the chain i.e. to adjust the position of the axle in the back forks, it is
partially rotated by any suitable means when by reason of the controlling action
of the slotted washers and pins or pegs it is caused to move along the slots of the
jaws of the forks parallel to its original position.
As an alternative construction the washers may carry the pins or pegs and the
slots be formed either in the jaws of the forks or in pieces fixed thereto.
I may also use an ordinary draw bolt on either side to adjust the position of
the axle, the device hereinbefore described ensuring its parallel movement.
Date
improvements in and relating to Chain-adjusting Devices for
Velocipedes.
I, GEORGE PILKINGTON MILLS, of "The Woodlands," Beeston, in the County of
Notts, 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 that class of chain geared velocipede in which the
adjusting and tensioning of the drive chain is performed by the drawing backwards
bodily of the axis or spindle of one of the velocipede's wheels, and, in the case of a
safety velocipede, has particular reference to the employment of the ordinary flat
[Price 8d1

page_text: and slotted back fork ends, wherein the ends of the back wheel axle or spindle slide,
now so extensively used.
The invention consists in an improved means to be used in combination with the
slotted back fork ends, before referred to, and the ends of the wheel axis or spindle
working therein, for controlling the movement of the adjusted wheel and for
adjusting and tensioning the drive chain, the said means having for their primary
object the obtainment of a parallel and simultaneous movement of both the ends of
the axis or spindle, so as to ensure the alignment and tracking of the chain and
velocipede wheels at all times, and secondary the simple and neat manner in which
the said parallel movement of the adjusting is effected.
That a difficulty at present exists in obtaining a perfectly true adjustment of both
the ends of the back wheel spindle in their framing slots by the use of the ordinary
adjusting draw-bolt mechanism is an acknowledged fact by every cyclist, and
especially by those who have no mechanical knowledge,-ladies for instance-and,
as such a deal of the accuracy in the running of a cycle depends upon this par-
ticular adjustment, it is felt that the improved device hereinafter set forth will have
exceptional advantages.
In the accompanying sheet of drawings the chain adjusting device according to
this invention is shown applied to the axis or spindle of the rear wheel and to the
slotted back fork ends of a safety diamond frame cycle, Figs. 1 and 2 representing
side elevations of the particular parts applied, the said figs. being dissimilar only
in that in Fig. 2 parts are in section or removed and a dotted position of the
adjusting means is shown. Fig. 3 is a back view of Fig. 1, showing the hub or
centre of the back wheel in elevation and the adjusting device in elevation upon
the one side of the back fork ends and in section upon the other side, whilst
Figs. 4 and 5 show some of the parts of the adjusting device upon the one side of
the machine separate. In Figs. 6 and 7 slight modifications or variations of the
adjusting device, Figs. 1 to 5, are set forth.
The same letters of reference are used to. indicate corresponding parts in the
whole of the figs, of the drawings.
In Figs. 1 to 5, a, a, are the lower members or chain stays of the back forks,
and c is the hub or centre of the back wheel, the former having slotted ends or
terminations a², a², of a well known construction, wherein the ends c², c², of the
spindle, of the latter, rest and slide. The bearings of the hub c may be built up in
any suitable way so long as abutment collars, or their equivalents, c³, c³, are
provided upon the hub and spindle ends to bear against the inside faces a³, a³, of
the slotted ends a² a. The spindle ends c², c², are free to move and slide in the
slots in the ends a², a², and are carried and controlled by washers d, d, mounted to
oscillate or rock upon a shifting or changeable fulcrum and to slide upon the outer
faces d², d, of the slotted ends.a² a². The shifting or changeable fulcrums of
these oscillating or rocking washers are formed by straight slots, d³, d³, in the
said washers, and pins or pegs d d carried stationary upon the slotted ends a², a²;
the said pins or pegs engaging the said slots a good fit and preferably holding the
said washers face to face with the faces d² of the slotted ends a².
The washers d, d, are, practically speaking, a pair of oscillating arms which
have a shifting fulcrum and which work upon and against the true or partly true
Hat faces of the back fork ends, and they carry the ends c2 c2 of the back wheel
spindle a tight fit within eyes, d³, d, formed within them, and prevent the spindle
rotating by having flats do, do, in the said eyes, the spindle ends, which have also
corresponding flats ct, c, upon them, being the medium for connecting and coupling
the said washers.
It will be obvious that the slots d³, 3 in the washers d, d work over and upon
the stationary pins and pegs d', d' when an adjustment of the spindle, and through it
the chain, is being effected, and that by reason of the said washers sliding face to
face and preferably in slight frictional contact upon the outer faces of the slotted
ends a, a, both the spindle ends must move simultaneous and in common, which
gives, for all practical purposes, a parallel adjustment.

page_text: a
In effecting an adjustment, the clamping or locking nuts e, e are first loosened
and then the spindle of the back hub is given, as it were, a partial rotation by a
key or a spanner, which is placed upon the flats upon one of the spindle ends,
preferably on the chain wheel side, and this so called partial rotation causes
rocking or oscillation in common of the washers, and serves, in conjunction with the
controlling action thereof, to effect a parallel and simultaneous adjustment of both
ends of the spindle, the said adjustment being afterwards again locked by tightening
up the nuts e, e, or one of them.
It is not thought necessary according to this invention to employ any means other
than the key, or the spanner, and the nuts e, e, for pulling back the spindle ends in
the slots, and for retaining them after being adjusted, as it is anticipated that the
adjusting device is sufficiently effective without, but, if necessary, the usual bolts for
drawing back and retaining the spindle ends in their adjusted position may be used,
although in this particular case one screw bolt (preferably upon the chain wheel
side) for drawing back the spindle ends and for retaining them when drawn back is
sufficient.
In the modification shown in Fig. 6 the slots ³ ³ are formed within the slotted
ends a², a², and the pins or pegs d, d, which engage them, are carried rigid upon
the inside faces of the oscillating washers d, d.
In the modification shown in Fig. 7 the slots d³, d³, in the oscillating washers are
radial or curved, but other than this the arrangement of the parts is identical with
the arrangement shown and described in connection with Figs. 1 to 5.
If necessary, oscillating washers with shifting fulcrums can be provided upon the
inside faces of the slotted ends a², a², as well as upon the outside faces, and these
may be coupled so that they work nicely upon both faces; it being understood that
the larger the area of the surfaces in contact the more sure will be the parallel
movement.
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 :-
First. A chain adjusting device for velocipedes characterised by slotted parts
upon the stationary framing which form guides and rests for the ends of the
spindle or axis of the wheel to be adjusted, oscillating or rocking washers carried
upon or by the slotted parts of the frame, and which have shifting or moveable
fulcrums, and which preferably work against the faces of the slotted parts and carry
the ends of the said wheel axis or spindle so as to ensure them a parallel and
together movement within the guide slots of the framing if either side or any part
of the wheel is drawn back for adjustment, substantially as set forth.
Second. In combination, in a chain adjusting device for velocipedes, slotted
frame ends a², a², wheel axis or spindle ends, c2, c², sliding therein, oscilating or
rocking washers d, d, carrying the said spindle ends and movably fulcrummed
upon the slotted ends a² a² by slots and pins or pegs so that they work face to face
with the said slotted ends, and means for locking the parts when adjusted such
as e, e, substantially as and for the purpose set forth.
Third. In a velocipede, the means described for obtaining the parallel adjust-
ment of the wheel axis or spindle to tighten the drive chain in combination with
the method of effecting the adjustment as set forth.
Dated this lot 1
W. P. THOMPSON & Co.,
11, Burlington Chambers, New Street, Birmingham,
Patent Agents for the Applicant.