Improvements in Means for Adjusting the Driving Chains of Cycles.
Year: 1898

page_text: Date of Application, 29th Oct., 1898
Complete Specification Left, 25th July, 1899-Accepted, 26th Aug., 1899
PROVISIONAL SPECIFICATION.
Improvements in Means for Adjusting the Driving Chains of Cycles.
We, ADAM LEE, FREDERICK GRAHAM ISHERWOOD, and JAMES EDMUND
WHITTAKER, trading as the Queece Cycle Co., of Chamber Works, Oldham, in
the County of Lancaster, Manufacturers, and ALFRED GARRISON, of the same
address, Works Manager, do hereby declare the nature of this invention to be
as follows;
This invention relates to improved means for adjusting the tightness of cycle
driving chains, one form of our invention being applied to the driving wheel
of the cycle and another form to the bottom bracket. The latter modification
operates by adjusting the position of the pedal crank axle, and while being
applicable to machines for single riders it is more especially intended for tandem
machines and multicycles.
For the purposes of our invention as applied to the driving wheel
near each end
of the cycle we provide the spindle of the said wheel
thereof with a cam which takes a bearing against a shoulder on the stay rod or
bottom member of the frame and forms an abutment for keeping the centre of the
driving wheel at the proper distance from the centre of the chain wheel on the
pedal crank axle. When the tightness of the chain requires adjustment, it is
effected by slacking back the tightening or locking nuts on the end of the driving
wheel axle and then turning the cams through a suitable angle so as to move the
axle in its bearing slot, after which the nuts are screwed up again to lock the
axle and cams in their adjusted position. We provide holes in the side of the
cams to allow of turning them by means of peg keys. A suitable form
of cam for the above purpose is an ordinary eccentric with a circular periphery.
When applying our invention to the bottom bracket, we mount the pedal crank
axle in a bearing carried by a swing arm, which is pivoted on a bolt or other-
wise so that it can swing to and fro, the frame or bottom bracket being suitably
constructed to allow of such swinging movement. The pivot may be above or
below the axle.
The position of the arm is determined and adjusted by means of fore and aft
screws screwed into the bottom bracket and bearing against the arm. Lock nuts
are provided for fixing the screws when the adjustment is made.
In tandem machines and multicycles one such chain adjustment may be applied
to each bottom bracket, but if desired the rear chain may be adjusted by the
first described modification or in any other suitable manner.
Dated this 28th day of October 1898.
GEORGE HARRISON,
35, Therapia Road, Honor Oak, London, Agent for the Applicants.

page_text: Improvements in Means for Adjusting the Driving Chains of Cycles.
ADAM LEE, FREDERICK GRAHAM ISHERWOOD, and JAMES EDMUND WHITTAKER,
trading as the Queece Cycle Co., of Chamber Works, Oldham, in the County of
Lancaster, Manufacturers, and ALFRED GARRISON, of the same address, Works
Manager, 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 improved means for adjusting the tightness of the
driving chains of cycles, one form of our invention being applied to the driving
wheel of the cycle and another form to the bottom bracket. The latter modifica-
tion operates by adjusting the position of the pedal crank axle, and while being
applicable to machines for single riders it is more especially intended for tandem
machines and multicycles.
or
For the purposes of our invention as applied to the driving wheel of the cycle
we provide the spindle of such wheel near each end thereof, with a cam
eccentric disc which takes a bearing against a shoulder on the stay rod or bottom
member of the frame and forms an abutment for keeping the centre of the
driving wheel at the proper distance from the centre of the chain wheel on the
pedal crank axle. When the tightness of the chain requires adjustment, it is
effected by slacking back the tightening or locking nuts on the end of the driving
wheel axle and then turning the cams or discs through a suitable angle so as to
move the axle in its bearing slot, after which the nuts are screwed up again to
lock the axle and cams in their adjusted position.
When applying our invention to the bottom bracket, we mount the pedal crank
axle in a swinging bracket adjustable in the bottom bracket which is suitably
constructed for the purpose, the position of the axle being determined and
adjusted by means of fore and aít screws screwed into the bottom bracket and
bearing against the swinging bracket.
Referring to the accompanying drawings,
Fig. 1 is a side elevation, and Fig. 2 is a sectional plan of our improvement
applied to the spindle of the driving wheel; and Fig. 3 is a side elevation, and
Fig. 4, a plan of our improvement applied to the bottom bracket.
A is the bottom member of the frame, slotted at the end in the usual manner
to receive the driving wheel spindle D and to allow of the adjustment of the
said spindle. B is the inclined member of the frame secured in the usual manner
to the spindle. C is the cam or eccentric disc which is mounted loosely on the
spindle and placed between the members A and B. One such cam or eccentric
is provided on each side of the driving wheel and bears against the shoulder E of
the bottom member, and so resists the pull of the driving chain. The cam or
disc is locked in any position to which it may be set, by screwing up the nut F
in the usual manner. To adjust the tightness of the chain the nut F is slacked
back and the cam C is turned by means of a peg key until the desired tightness
is produced, and then the nut is tightened up again. Holes G are formed in
the side of each cam or disc to allow of the use of the peg key for turning the cam.
The discs or cams are independent of each other and the most accurate adjustment
of the spindle I can therefore be ensured.
Referring now to Figs. 3 and 4 H is the swinging bracket which carries the
pedal crank axle, said bracket being hinged or pivoted by its arms H¹ upon a bolt
or pivot pin J. The bottom bracket K is formed with a longitudinal slot K'
to allow the bracket H to swing. L. L are set screws screwed through the

page_text: bottom bracket, and having their ends hearing against the body of the swinging
or adjusting bracket. M, M are lock nuts for securing the set screws in their
adjusted position. The adjustment is effected by slacking back the nuts M, M
and then turning the screws L, L until the desired tightness of the chain is pro-
duced, after which the nuts M, M are screwed up again to lock the screws.
We have shown the bracket swinging from a bolt above the axle, but it may
be equally well arranged to turn on a bolt below the axle.
In tandem machines and multicycles one such chain adjustment may be applied
to each bottom bracket, but if desired the rear chain may be adjusted by the
first described modifications, or in any other suitable manner.
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. The cams or eccentric discs rotatable on the axle of the driving wheel and
bearing against shoulders on the bottom members or stay rods of the frame, and
arranged to be locked when the nuts on the end of the axle are screwed tight,
all substantially as described, and for the purpose specified.
2. The pedal crank axle mounted in a bearing carried by a swinging bracket
which is adapted to be adjusted by set screws, the bottom bracket being slotted
to allow of such adjustment, substantially as described, and for the purpose
specified.
3. The means for adjusting the tightness of the driving chain of cycles, sub-
stantially as described with reference to Figs. 1 and 2, or to Figs. 3 and 4, and
operating as specified.
GEORGE HARRISON,
10, Staple Inn, London, W.C., Agent for the Applicants.