IMPROVEMENTS IN SPEED AND POWER GEARING FOR VELOCIPEDES
Year: 1884

page_text: We CHARLES MONTAGUE LINLEY Engineer of N° 49 Dynevor Road Stoke
Newington in the County of Middlesex JOHN BIGGS Engineer of 9 Melior Street
Southwark in the County of Surrey and GEORGE GRAINGER TANDY Surgeon
of 43 Cedars Road, Clapham in the County of Surrey do hereby declare the
nature of this invention for IMPROVEMENTS IN SPEED AND POWER GEARING FOR
VELOCIPEDES to be as follows:-
This invention relates to means for altering at will the comparative speeds of the
treadle shaft and the wheel axle with the object of gaining power or speed as
required and the invention consists essentially in a novel construction of expanding
chain wheel the action of which may be produced direct from the treadle shaft.
In carrying out our invention we employ two discs which we fix at a suitable
distance apart on the treadle shaft. On the inner face of each of these discs is
formed a volute groove and the discs must be so mounted that these grooves
correspond exactly.
In place of teeth we use a short length of chain constructed in a manner somewhat
similar to an ordinary driving chain except that the joint pins are prolonged on
either side to enter and work in the grooves on the discs.
To avoid friction as much as possible we prefer to mount antifriction rollers on
the projecting ends of the joint pins.
Projecting radially from and mounted loosely on the treadle shaft outside one of
the discs is an arm to the outer end of which is pivotted at or near the bend, a
U-shaped piece, which spans one of the discs, one arm which we will term the
inner arm, of this U piece is attached to the forward end of the chain and the other
or outer arm which is made thin and acts as a flat spring is provided on one side
with a locking pin which takes into a series of holes in the disc and on the other
side with a bevelled projection or catch which is intended to strike against a
moveable stop. This stop will usually be held out of action by a spring but will
be thrown into action when required by means of a hand lever connected there-
with or in any other convenient manner.
When the stop is out of action the chain will be locked to the discs by means of
the pin, but on throwing the stop into action the catch will, by reason of its shape
or striking against the stop, draw the pin out of the disc and allow the pair of
discs to rotate with the shaft irrespective of the chain which under the influence
of the volute grooves will be expanded or contracted as the case may be.

page_text: The holes in the disc will be arranged to correspond to the grooves and they are
formed at regulated intervals.
The means above described for holding the chain irrespective of the discs and
for locking the chain to the discs are however capable of modification without
departing from the essential features of our invention viz:-making an expansible
chain wheel for velocipedes of two grooved discs with the chain working between
them in the grooves.
The driving chain we form of links shaped somewhat like a flattened U, which
are pivotted together at their ends in any convenient manner so that the
connected ends of two links shall enter between the joint pins of the chain of the
chain wheel.
The chain must be of sufficient length to pass round the chain wheels when of
the larger diameter the slack caused by the reduction in the diameter of the chain
wheel or wheels being taken up by any convenient means such for instance as a
tension spring or a weighted lever pivotted to the frame and carrying a pulley or
roller round which the chain passes.
Either or both of the chain wheels may be made expansible but in general we
prefer that the chain wheel on the treadle shaft only shall be expansible as it is
more convenient to operate.

page_text: We CHARLES MONTAGUE LINLEY Engineer of N° 49 Dynevor Road, Stoke
Newington in the County of Middlesex, JOHN BIGGS, Engineer, of 9 Melior Street,
Southwark in the County of Surrey, and GEORGE GRAINGER TANDY Surgeon of
43 Cedars Road Clapham in the County of Surrey do hereby declare the nature of.
our invention for IMPROVEMENTS IN SPEED AND POWER GEARING FOR VELOCIPEDES
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 means for altering at will the comparative speeds of
the treadle shaft and the wheel axle with the object of gaining power or speed
as required, and the invention consists essentially in a novel construction of
expanding chain wheel the action of which may be produced direct from the treadle
shaft.
In carrying out our invention we employ two discs which we fix at a suitable
distance apart on the treadle shaft and on the inner face of each of these discs is
formed a volute groove to receive a short length of chain the joint pins of which
enter and work in the grooves in the discs.
In the accompanying drawing :-
Fig 1 is a side elevation with one wheel re:noved, of a tricycle to which our
invention is adapted.
Fig: 2 shows the inner face of one of the discs, with the chain in the
contracted position and
Fig 3 is an edge view of the gear as shown in Fig: 1.
A is the framing of the machine which may be of any convenient construction
and adapted either for a front or rear steerer.
B is the main driving axle, which carries the framing in any suitable manner and
C is the crank axle, which is mounted in suitable bearings secured in any.
convenient manner to the framing A.
The improved speed and power gear consists of two discs D D' (see Fig: 3) each
of which is formed with a volute groove a on its inner face, as shown at Fig: 2.
The two discs D D¹ must be mounted on the crank axle C, so that the two grooves
exactly correspond and they are secured to the axle in any convenient manner.
Between the discs is placed a short length of chain 6 which is constructed in a
manner similar to the ordinary driving chain except that the joint pins are
prolonged on either side so as to enter and work in the grooves a of the discs.
To avoid unnecessary friction we mount on the projecting ends of the joint pins of;
the chain b small antifriction rollers.
Projecting radially from and mounted loosely on the treadle or crank shaft C,
outside one of the discs, is an arm c to the outer end of which is pivotted, at or
near the bend one arm d of a U shaped piece which spans one of the discs. The
other or inner arm d' of this U piece is attached in any convenient manner to the
forward or outer end of the chain b (see Fig: 2) and the outer arm d which is made
thin acts as a flat spring.
This arm d is provided, on its under or inner side with a locking pin or stop e
which is arranged to enter a series of holes f made in the disc, and on the outer or
upper side with a bevelled bridge piece g to receive an arm h which is mounted
loosely on the treadle or crank axle and is intended to strike against a movable
stop i This stop is placed at one end of a lever j which has its fulcrum on the
frame, the other end being connected by a link k to a vertical rod / provided with

page_text: a handle m, and which is secured in any convenient manner within reach of the
rider's hand so that it may be raised or lowered as desired to throw the stop in or
out of action. When the stop is out of action the chain will be locked to
the discs by means of the pin or stop e but on throwing the stop into action the
arm h acting on the bevelled portion of the bridge piece g will draw the pin e out
of the hole in the disc and allow the pair of discs to rotate with the shaft
irrespective of the chain, which, under the influence of the volute grooves and
being firmly held by the arm d' of the U piece will be expanded or contracted as
the case may be.
The holes in the disc, must be arranged to correspond to the grooves and they are
formed at regulated intervals which will admit of the diameter of the expanding
wheel being enlarged or contracted to any size within certain limits.
The means above described for holding the chain irrespective of the discs and for
locking the chain to the discs, and also for actuating the stop h are however capable
of modification without departing from the essential features of our invention,
viz., making an expansible chain wheel for velocipedes of two grooved discs with
the chain working between them in the grooves.
The driving chain E we form of links shaped somewhat like a flattened U, which
are pivotted together at their ends in any convenient manner so that the connected
ends of two links shall enter between the joint pins of the chain 6 of the chain
wheel or pulley D D¹.
The chain E must be of sufficient length to pass round the chain wheel D D¹
when of the largest diameter, the slack caused by the reduction in the diameter of
the wheel being taken up by any convenient means, such, for instance, as a tension
spring or a weighted lever pivotted to the frame and carrying a pulley or roller
round which the chain passes.
Either or both of the chain wheels may be made expansible, but in general we
prefer that the chain wheel on the treadle shaft only shall be expansible as it is
more convenient to operate. The chain wheel on the driving axle may be
of any construction suitable to receive a driving chain of the character above
described but we prefer that this wheel should drive through a ratchet motion.
The machine is provided with steering gear and grip handle of the usual
construction.
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: In speed and power gearing the expansible chain wheel or pulley consisting
essentially of a pair of grooved discs and a short length of chain, the joint pins of
which are prolonged and work in the grooves substantially as herein shown and
described.
.
2. The means for securing the end of the chain b; for locking and unlocking
the discs, and for actuating the stop arrangement all substantially, as herein shown
and described.