Improvements in Chain Adjusters and Means for Facilitating the Removal of the Back Road-wheel of Cycles.
Year: 1898

page_text: PROVISIONAL SPECIFICATION.
Improvements in Chain Adjusters and Means for Facilitating the
Removal of the Back Road-wheel of Cycles.
I, FRANCIS GWYN GRIFFITH, of Llansannor House, near Cowbridge, in the
County of Glamorgan, Gentleman, do hereby declare the nature of this invention
to be as follows:-
This invention relates to improvements in chain adjusters and means for faci-
litating the removal of the back road-wheel of cycles, and the object of it is
to facilitate the removal of the back road-wheel of the machine in the event
of a puncture of the tyre, or for other repairs or purposes.
It may be advantageous here to remark that the method now commonly
adopted for adjusting the tension of a cycle chain, consists in providing an open
forked end to the bottom stay, a stout screw with an eye at one end, called an
eye-bolt, through the eye or hole of which the chain-side end of the spindle of
the back road wheel is threaded; or, in other words, the eye of the bolt is placed
over the end of the said spindle. The said bolt is screw-threaded and the screw-
threaded portion, which is directed towards the rear of the machine, and extends
beyond the forked end of the bottom-stay, has a nut screwed on its end. The
said nut takes its bearing against the forked end of the bottom-stay, and on
being tightened up, draws the spindle and consequently the back sprocket wheel
with the chain around it, towards the rear, thus putting a greater tension upon
the chain, by increasing the distance between the crank axle and that of the rear
wheel;
so that, when it is required to remove the back road-wheel to effect a
repair, such for instance as a puncture in the tyre, it is necessary to first loosen
the ordinary clamping nut of the wheel, then loosen the tension nut of the
tension bolt, which slackens the chain, then take off that end of the chain from
the sprocket wheel and the wheel may be slid out backwards. This operation
thus involves considerable time and experience to effect.
My invention is designed to render the whole operation of removing the back
wheel a simple matter and one that may be effected by either a lady or gentle-
man or even a child in a few moments.
According to my invention, instead of the bottom-stay having an open forked
end, the said end is closed at its extremity and preferably rounded, and the
necessary opening or gate is situated at the bottom of the forward end of the
central slot, so that it merges into the said slot above at an angle. The usual
eye-bolt and nut are employed to perform their usual functions as hitherto,
but the screw-threaded end of the bolt is in just the reverse position, that is to
say it points forward instead of rearward, and the nut is not placed on its
extreme end to bear against the extremity of the fork end, because it has to
tighten the chain in the reverse direction, so I provide a downwardly directed
projection of the stay at the forward end of the slot and thread the nut suffi-
ciently far on the bolt to bear on the inside of this projection. The nut thus
hangs or rests in the gateway or opening into the slot. The nut may have a

page_text: circular groove in its bearing face and a corresponding projecting bearing tongue,
surface, or ring on the projecting extension forming the termination wall of the
front of the slot, and the nut may be circular and provided with teeth or milling
on its periphery, and a detent or pawl secured in a suitable position to engage
with the said teeth or milled edge to prevent the nut slackening back, if desired.
It will be understood that the gate of the usual slot is reversed and the mouth
of it is not at the extremity of the forked end of the stay, but at the forward end
of the slot between the forks and is not in alignment with the axis of the slot
but is at the bottom and merges into the slot at an angle, preferably, but not
necessarily, a right angle.
With my invention, the chain is slackened on drawing the wheel out and will
not consequently require to be unscrewed or removed from the sprocket, neither
do the mud-guards require to be unfastened, the wheel spindle slipping out for-
wards through the down slot or gate so that the wheel, chain, mudguards,
spindle, and tension device are detached from the cycle together, after simply
loosening the clamping-nut and turning the milled or tension-nut slack, the
tension-screw will then fall down allowing the wheel etc., to be slid back, when.
the wheel &c. drop together out downwards through the gate, the chain, or mud-
guards not having been interfered with.
Dated the 26th day of October 1898.
PHILLIPS & LEIGH,
Agents for the Applicant.
Improvements in Chain Adjusters and Means for Facilitating the
Removal of the Back Road-wheel of Cycles.
I, FRANCIS GWYN GRIFFITH, of Llansannor House, near Cowbridge, in the
County of Glamorgan, Engineer, do hereby declare the nature of this inven-
tion 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 improvements in chain adjusters and means for faci-
litating the removal of the back road-wheel of cycles, and the object of it is
to facilitate the removal of the back road-wheel of the machine in the event
of a puncture of the tyre necessitating a repair or for other repairs or purposes.
It may be advantageous here to remark that the method now commonly
adopted for adjusting the tension of a cycle chain, consists in providing an open
forked end to the bottom stay, a stout screw with an eye at one end, called an
eye-bolt, through the eye or hole of which the chain-side end of the spindle of
the back road wheel is threaded; or, in other words, the eye of the bolt is placed
over the end of the said spindle. The said bolt is screw-threaded and the screw-
threaded portion, which is directed towards the rear of the machine, and extends
beyond the forked end of the bottom-stay, has a nut screwed on its end. The
said nut takes its bearing against the forked end of the bottom-stay, and on
being tightened up, draws the spindle and consequently the back sprocket wheel
with the chain around it, towards the rear, thus putting a greater tension upon
the chain, by increasing the distance between the crank axle and that of the rear
wheel; so that, when it is required to remove the back road-wheel to effect a
repair, such for instance as a puncture in the tyre, it is necessary to first loosen
the ordinary clamping nut of the wheel, then loosen the tension nut of the
tension-bolt which slackens the chain, then take off that end of the chain from

page_text: the sprocket wheel and the wheel must be slid out backwards. This operation
thus involves considerable time and experience to effect.
I will now proceed to describe the invention in detail with the aid of the
accompanying drawings, in which:-
Figure 1 represents in side elevation the end of one of the bottom stays of a
bicycle provided with my improved chain adjuster and means for facilitating
the removal of the road wheel.
Figure is a sectional plan of Figure 1, the section being made on a line
passing through the middle of the adjusting-nut to shew the internal formation
of the said nut.
Figure 3 is an elevation of the rear end of the bottom stay, and
Figure 4 is a sectional elevation through the adjusting-nut.
My invention is designed to render the whole operation of removing the back
wheel a simple matter and one that may be effected by either lady or gentleman
or even a child in a few moments.
According to my invention, instead of the bottom-stay 6 having an open forked
rear end, the said end a is closed at its extremity m and preferably rounded as
shown in Figures 1 and 3, and the necessary opening or gate d for the entrance
of the wheel spindle is situated at the bottom of the forward end of the central
slot c, so that it merges into the said slot above at an angle. The usual eye-
bolt e and nut g are employed to perform their usual functions as hitherto, but
the screw-threaded end e of the said bolt is in just the reverse position, that
is to say, it points forward instead of rearward, and the nut is not placed on its
extreme end to bear against the extremity of the fork end, because it has to
tighten the chain in the reverse direction, so I provide a downwardly-directed
projection h of the stay at the forward end of the slot and thread the nut suffi-
ciently far on the bolt to bear on the inside of this projection. The nut thus
hangs or rests in the gateway or opening leading into the slot. The nut may
have a circular groove i in its bearing face and a corresponding projecting bear-
ing tongue surface, or ring on the projecting extension forming the termina-
tion wall of the front of the slot; and the nut g may be circular and provided with
teeth or milling on its periphery, and a detent or parl (not shown in drawings)
secured in a suitable position to engage with the said teeth or milled edge to
prevent the nut slackening back, if desired, or it may be of the ordinary hexa-
gonal form as shown.
It will be seen that the gate of the usual slot is reversed and the mouth of it
is not at the extremity m of the stay, but at the forward end of the slot, and
is not, as usual, in alignment with the axis of the slot but is at the bottom and
merges into the slot at an angle, preferably but not necessarily, a right angle, as
shown.
With my invention, the chain is slackened on drawing the wheel out and will
not consequently require to be removed from the sprocket, neither do the mud-
guards require to be unfastened, the wheel spindle slipping out forwards through
the down slot or gate d so that the wheel, chain, mudguards, spindle and tension
device are detached from the cycle frame together after simply loosening the
clamping nut and turning the milled or tension nut y slack, the tension screw
will then fall down or at all events be sufficiently loosened to allow the wheel,
etc., to be slid forward, when the wheel etc. drop together out downwards through
the gate d, the chain, or mud-guards not having been interefered with.
The above arrangement is of course made on each side of the wheel as usual.
kis a fragment of one of the back stays, and is the dress-guard connection plate.
It will be observed that the tension of the chain is applied by the screwing
forward of the nut i against the face of the stay end causing a rearward motion
of the tension screw or eyebolt c which of course carries with it in its eye the
spindle of the rear road wheel which latter bears the rear sprocket pinion and so
increases the distance between the two sprocket wheels and thus tightening the
chain passing around them.

page_text: Having now particularly described and ascertained the nature of my said in-
vention and in what manner the same is to be performed, I declare that what
I claim is:-
-
1. In a cycle frame for a chain-driven cycle having a longitudinal slot for the
reception of the spindle of the road wheel and adjustment of the tension of the
driving chain, an opening in the frame at or near the forward end of and leading
into said slot, as and for the purposes described.
2. In a cycle frame for a chain-driven cycle having a longitudinal slot for the
reception of the spindle of the road wheel and adjustment of the tension of the
driving chain, an opening in the frame at or near the forward end of and leading
into said slot, a projection on the frame at the front extremity of the said slot
and a nut having a circular groove in one of its faces supported and guided by
the said projection as and for the purposes described and illustrated.
Dotal the 20th lov of Vo 1800
PHILLIPS & LEIGH,
No. 22, Southampton Buildings, Chancery Lane, London, W.C.,
Agents for the Applicant.