Improvements in Speed Gear for Velocipedes.
Year: 1896

page_text: Date of Application, 25th Nov., 1896-Accepted, 16th Jan., 1897
Improvements in Speed Gear for Velocipedes.
I, WILLIAM GEORGE HEYS, of 70 Market Street, Manchester, in the County
of Lancaster, Chartered Patent Agent, 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 :-
The object of this invention is to enable cyclists to reduce their speed gear
when ascending hills, or when desired, without stopping the machine.
Speed gear constructed according to these improvements is illustrated by the
accompanying drawings to which reference is hereinafter made.
The principal parts of the gear are contained in and about the driving gear
wheel, as shewn by Figures 1 to 3 inclusive, of which Figure 1 shews a side
elevation, Figure 2 a section, and Figure 3 an edge elevation. They consist of a
rim a having on its outer surface, teeth to gear with the driving chain, a disc b
fitting and running upon ball bearings within the rim a and having internal teeth.
This disc has a hub which is fixed upon the shaft and one side of which is
prolonged so that the pedal arm M may be fixed upon it as shewn by Figure 2.
Upon the opposite side of the hub there is arranged thereon a movable toothed
wheel c, whose teeth are external to it. The disc is placed within the rim a and
retained by means of an annular steel plate d attached to the rim by the screws vv.
The opening in this plate allows the toothed part of the wheel c to be passed
through it. This wheel c has a flange which then comes into contact with the
annular plate. Between the teeth of the disc b and those of the wheel c and
gearing therewith there are arranged two diametrically opposite pinions p p the
spindles of which are riveted or fastened to the annular plate. A notch fis made
in the flange of the wheel c and serves a double purpose. In this notch there
engages a bolt g' which carries a cam hereinafter described. The bolt is capable
of sliding between two guides h h fixed upon the plate d and is normally forced
towards the centre of the plate by the springs rr, attached to the bolt as herein-
after described, and abutting upon the stops a a fixed upon the plate d. When
the bolt is in engagement with the notch f the speed gear is fixed.
Another bolt g is capable of engagement with the notch f. This bolt is carried
in bearings on the bracket or framing of the machine as shewn by Figures 3
and 4 or in any other suitable and similar manner. Motion in the direction of its
axis may be given to this bolt in two different ways. As shewn by Figures 1 and 3
that part of the bolt which is in the bearing is enlarged and provided with a
helicoidal slot or groove in which there engages the point of a stud k. If, looking
towards the chain wheel the bolt g is rotated "clockwise" or to the right, it will
be advanced towards the chain wheel and finally come into contact with the cam o
and thus displace the bolt gl. Immediately thereafter the bolt g³ falls into the
notch and engages the wheel c which is thus prevented from rotating. The
continued motion of the pedals maintains the rotation of the disc b, the teeth of
which engage with the pinions pp gearing with the teeth of the temporarily fixed
wheel c. The axes of these pinions being fixed to the plate d, which is also fixed
to the rim a, the latter will be rotated at a reduced speed.

page_text: There may be fixed upon the bolt g³ a grooved sector upon which there is
fixed one end of a band strap, or chain l, the other end of which is under the
control of the cyclist, who is enabled by this means, by a simple pull or release,
to put the reduced gear into and out of action. The motion of this bolt may
however be effected in other ways, as will be obvious. With the arrangement
shewn, the spring n will, when the cord is released, push the bolt 9 out of
engagement with the notch f.
As soon as the bolt g2 is released, the resistance to the drive brings the wheel o
again into rotation and the bolt g' soon re-engages with the notch f, re-establishing
the status quo ante.
In the disc b, an oil hole may be formed, closable by the screw B when not
in use.
The cam o may form part of the bolt gl or may be attached thereto. The
springs, because of their necessary strength and of the limited space they must
occupy, are preferred to be attached to the bolt and cam by a special device. As
illustrated by Figure 5, the cam o is formed of sheet steel fixed upon the. bolt,
and its outer end is turned to form a U-shaped recess in which the central part y
of the springs is held. Lateral motion of the springs is prevented by forming in
them, on one side, a shallow groove y (as shewn separately at the bottom of
Figure 5), which groove. engages with the turned part of the cam plate.
A different method of actuating the bolt is illustrated by Figure 4. In this
case, the bolt is not turned upon its axis but is slided to and fro. A collar m is
fixed upon the bolt and forms an abutment for one end of a spiral springs which
is arranged to force the bolt into engagement with the notch in the flange of the
wheel c. Bearing against the collar, is one end of a right angled lever t, fulcrumed
at t. The other end of this lever has attached to it a cord or the like which is
under the control of the cyclist.
Although the rim a has herein before been described as constructed to gear
with a chain, it may be otherwise constructed according as the motion is transmitted
by toothed gear, by friction, by straps or cords, or by other means.
Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed, as communicated to me by
my foreign correspondent, I declare that what I claim is :-
Speed gear for velocipedes, constructed and arranged substantially as herein-
before described with reference to the accompanying drawings.
Dated this 24th day of November A.D. 1896.
WILLIAM GEO. HEYS.