Improvements in or relating to the Driving Mechanism of Bicycles.
Year: 1899

page_text: Date of Application (in United Kingdom), 19th Dec., 1899
Complete Specification Left, 17th Sept., 1900-Accepted, 15th Dec., 1900
Improvements in or relating to the Driving Mechanism of Bicycles.
I, ANDREW CHRISTIAN NYGAARD, of Rawlins, in the County of Carbon and
State of Wyoming, United States of America, Gentleman, do hereby declare
the nature of this invention to be as follows:-
This invention relates to chainless bicycles and has for its object to provide
driving mechanism whereof a change of speed may be effected and which may
be applied to any form of machine.
The driving gear of my invention comprises an extensible shaft mounted in a
telescoping casing, a double pinion secured to the shaft by means of a stem
engaging with the end of the casing, a double bevel gear wheel secured on the
pedal shaft and mechanism adapted to be conveniently operated by devices
within reach of the rider for causing the pinion to be brought into engagement
with one or other of the gears of the bevel wheel.
The casing is constructed in two telescopic sections both of which are secured
to one of the members of the rear fork of the machine frame and the shaft is
formed in two sections, one of which is provided with a polygonal inner end
while the other is tubular and fits on the polygonal portion of the first so that
the shaft and sleeve revolve as one. for which purpose they are mounted in
suitable roller or ball bearings contained within the casing. A bevel pinion
is secured to the outer end of the shaft and said pinion gears with a bevel pinion
located on the axle of the rear wheel of the machine. A spring is attached to
the inner end of the polygonal portion of the shaft, and this spring is continued
forward within the sleeve and is secured to a stem to which the double pinion
is attached, which pinion is also securely fastened to the sleeve.
The teeth with which the double bevel pinion is provided at each end
respectively engage with the teeth of the double bevel gear wheel, the arrange-
ment of the double gear being such that when one is in engagement, the other
will be out of engagement. When the teeth on the forward end of the pinion
engage with the gear wheel, a slow speed is obtained with considerable power,
which is of great advantage in hill climbing or in riding against the wind, and
when the other is in engagement an increase of speed may be attained.
A collar is secured to the stem of the double pinion and this collar is in con-
tact with the forward end of the casing which is preferably made to slide
longitudinally in its hanger. The change in speed is produced by drawing
forward the said section and placing the spring under tension, or permitting the

page_text: spring to restore the sections of the casing to their normal position. The
forward section of the casing may be shifted in various ways. Preferably this
is accomplished by attaching one end of a chain to said section and carrying
the chain upward through a tube that is attached to the frame, which tube,
near its upper end and convenient to the handle bars, is provided with an
enlarged chamber. A spindle is mounted to turn in this chamber, said spindle
being provided at its end with a thumb screw by which it may be manipulated.
A spring is coiled around said spindle within the chamber, one end of the
spring being attached to the chamber wall and the other end having bearing
against a pawl, the spring serving to normally hold the pawl in engagement
with the teeth of a pinion secured upon a shaft which is journalled in said
chamber and provided with a crank arm at one of its extremities. The pinion
engages with a gear wheel secured upon a shaft, which shaft also carries a
drum to which the other end of a chain is attached. The spring continually
exerts pressure upon the pawl thus holding the pawl against the teeth of the
pinion. By turning the thumb screw the pawl may be taken out of contact
with the pinion thus permitting said pinion to turn freely. When it is desired
to proceed at a low rate of speed the crank is turned, thus winding up the
chain and drawing forward the double gear pinion until it engages with the
inner bevel gear of the disc.
When it is desired to travel at a high rate of speed the pinion is released
from engagement with the pawl when the double gear pinion engages the outer
gear of the double bevel gear wheel.
The shifting mechanism may be utilized as a brake mechanism, since by turn-
ing the crank hard it will cause the teeth of the double gear pinion to press
with force upon the inner bevel gear of the disc enabling the rider of the
bicycle to travel down a steep hill in safety.
Total 41: 101 1
בד
1000
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
Improvements in or relating to the Driving Mechanism of Bicycles.
I, ANDREW CHRISTIAN NYGAARD, Gentleman, of Rawlins, in the County of
Carbon and State of Wyoming, United States of America, 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 my invention is to so construct the driving mechanism of a
chainless bicycle that a change may be made from high to low speed at the
will of the rider, the means for effecting said change being adjacent to the
handle bar so as to enable the change to be conveniently made. The driving
mechanism is simple, durable and economic, comprises but few parts and those
not liable to derangement, and may be applied to any form of machine.
The invention consists in the novel construction and combination of the
several parts, as will be hereinafter fully set forth and pointed out in the claims.
Reference is to be had to the accompanying drawings forming a part of this
specification, in which similar characters of reference indicate corresponding
parts in all the figures.
Figure 1 is a side elevation of the bicycle having the improved driving
mechanism applied: Figure 2 is a horizontal section through the rear portion

page_text: of the frame of the bicycle and through the driving mechanism applied thereto;
and Figure 3 is a vertical section through the casing in which the shifting
mechanism is contained, said mechanism appearing in side elevation.
The crank hanger A is provided with the usual crank shaft 10; but a driving
wheel A is secured upon the said crank shaft between one of the pedal arms
and the crank hanger, and this driving wheel is provided upon its inner face
with a hub gear 11 and a peripheral gear 12, both of the bevel type.
B is a casing constructed in two telescopic sections 13 and 14, both of said
sections being secured to one of the members of the rear fork of the bicycle
frame, as clearly shown in Figure 2, by hangers 15 or their equivalents. A
shaft 16 is mounted to revolve within the said casing, and said shaft is pro-
vided at its inner end with a polygonal section 16. A tubular shaft 17 is
made to telescope with the polygonal portion 16% of the shaft 16, and that
portion 17 of the shaft 17 that thus engages with the shaft 16 is correspond-
ingly shaped in cross section to the cross section of said polygonal portion 16ª
of the shaft 16. These two shafts 16 and 17 are adapted to revolve, and to
that end are mounted in suitable roller or ball bearings 18. A bevel pinion 19
is secured to the outer end of the shaft. 16, and said pinion meshes with a bevel
pinion 20, on the axle of the rear wheel of the machine. A spring 21 is attached
to the inner end of the polygonal portion 16" of the shaft 16 and this spring is
continued forward within the tubular shaft 17 and is secured to a stem to
which a double bevel pinion 22 is attached, which pinion stem is securely
fastened directly or indirectly to the tubular section 17 of the shaft. This
double pinion comprises a front bevel section 22, the teeth whereof are arranged
for engagement with the hub gear 11 and a rear bevel section 22, the teeth
of which are adapted to engage with the peripheral gear 12 of the driving
wheel A and when one section of the double pinion 22 is in mesh with the
driving wheel A¹ the other section is out of engagement therewith. When the
inner section 22b of the double pinion 22 is made to engage with the hub gear 11
of the driving wheel, a slow speed is obtained, yet considerable power, which
is very available in hill climbing or in riding against the wind, and when
the double pinion is in mesh with the peripheral teeth 12 of the driving
wheel A considerable speed may be attained.
It will be observed that the angle of the wheels 22ª and 12 is much smaller
than that of the bevel wheels 11 and 22b, so that said wheels 22ª and 12 form an
approximation to angle gear, in which one of the wheels has practically parallel
teeth.
A collar 23 is secured to the stem of the double pinion 22, which abuts
against the forward end of the section 14 of the casing. The section 14 of the
casing is preferably made to slide in its hanger, and the change in speed is
produced by drawing forward the said casing section 14 and placing the
spring 21 under tension, or permitting the spring 21 to restore the sections of
the casing to their normal position, which is when the double pinion is in
mesh with the peripheral teeth 12 of the driving wheel A'.
The section 14 of the casing may be shifted in various ways. Preferably this
is accomplished by attaching one end of a chain 24 to the section 14 of the
casing and carrying the chain upward through a tube 25, that is attached to
the frame, which tube, near its upper end and convenient to the handle bars,
is provided with an enlarged chamber 26, (shown best in Figure 3). A spindle 27
is mounted to turn in this chamber 26, being provided at its outer end with a
thumb screw 28, by which it may be manipulated, and a spring 29 is coiled
around said spindle within the chamber, one end of the spring being attached
to the chamber wall and the other end having bearing against a pawl 30, the
spring serving to normally hold the pawl in engagement with the teeth of a
pinion 31, secured upon the shaft 32 journalled in said chamber and provided
with a crank arm 33 at one of its extremities. The pinion engages with a
gear 34, secured upon a shaft 35, which shaft also carries a drum 36, to which

page_text: the other end of the chain 24 is attached. The spring 29 continually exerts
pressure upon the pawl 30, thus holding the pawl against the teeth of the
pinion 31. By turning the thumb screw 28 in proper direction the paw! 30
may be taken out of contact with the pinion 31, permitting said pinion to turn
freely. When it is desired to proceed at a low rate of speed, the crank 33 is
turned, thus winding up the chain 24 and drawing forward the double pinion 22
When it is desired to
and engaging the section 22b with the hub gear 11.
travel at a high rate of speed, the pinion 31 is released from engagement with
the pawl 30 and the section 22 of the double pinion 22 is permitted to engage
with the larger ring of teeth 12 of the driving gear A¹.
The shifting mechanism shown in Figure 3 may be utilized as a brake
mechanism, since by turning the crank 33 hard it will cause the teeth of the
double pinion 22 to press with force upon the driving gear A¹ enabling the
The drum 36 is not
rider of the bicycle to travel down a steep hill in safety.
absolutely needed, since the chain 24, or a substitute therefor, may be wound
directly upon the shaft 35.
Having now particularly described and ascertained the nature of the said
invention and in what manner the same is to be performed, I declare that what
I claim is
1. In a bicycle, a driving gear consisting of an extensible shaft mounted in
a telescoping casing carried by the frame, said shaft consisting of a rear section
having a polygonal inner end, and a tubular forward section, fitting on the
polygonal end of the rear section, the rear section of the said shaft carrying
at its rear end a pinion engaging the drive wheel of the bicycle, while a double
pinion has its stem projecting into the forward end of the tubular section of
the shaft and secured thereto, said stem being provided with a collar for
engaging the end of the casing, a spring in the tubular section of the shaft
and having one end secured to the polygonal end of the rear shaft section and
its other end to the stem of the double pinion, and a double gear wheel on the
pedal shaft, substantially as described.
2. In a bicycle in combination with a driving gear such as claimed under
head 1, a shifting mechanism for the double pinion, said mechanism consisting
of a shaft, a chain or the like having one end secured to the shaft and the other
to one section of the telescoping casing, a second shaft geared with the first
named shaft, and provided with a crank handle at one end, a spring-pressed
pawl engaging a gear wheel on said second shaft to prevent backward movement
of the same, and means for manipulating the pawl from the outside of the
casing, substantially as described.
TY
1
זן,
11
of Santambar 1900
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.
A. M. & WM. CLARK,
Chartered Patent Agents, 53, Chancery Lane, London.