Note: Descriptions are shown in the official language in which they were submitted.
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APPARATUS FOR CHANGING POWER DII~ECTION FOR BICYCL~
Technical Field
The present invention relates to an apparatus for ch~nging power direction
for a bicycle, and more particularly, to an apparatus for ch~n~ing power direction
~tt~ h~od to a pedal shaft hub for a bicycle in which the bicycle can travel forward
at all tirnes by controlling a ch~nging lever when pe~1~1in~ the bicycle forward or
rearward, and an idling is also allowed if required when pedaling the bicycle
rearward, like when pedaling a conventional bicycle rearward.
Back~round Art
Generally, a bicycle includes front and rear wheels before and after a
bicycle frarne, and a pair of pedals as a power supply source between two wheels.
The driving force for bicycle is obtained through pedaling and then the force istr~n~mittt-d to the rear wheel via a driving sproclcet, a chain and a driven sprocket.
This general bicycle travels forward when pedaling forward by a rider and the rear
wheel of the bicycle rotates without load by an one-directional ratchet of a hub of
the rear wheel when pedaling rearward, wherein the rotation of the rear wheel
without load is called "idling".
Also, inventions for new parts of bicycle which can allow of bi-directional
pedaling to the general bicycle to which only one-directional pedaling is allowed
have been disclosed. Particularly, those of Mantzoursos et al. and Foster et al. will
be introduced as follows.
According to the invention of ~antzoutsos et al. (EPO Publication No.
0,369,925), two gears are installed on a pedal shaft and an auxiliary gear is
in~t~lle(l between two gears to be detachable. ~ere, the bicycle of this invention
can travel like a general bicycle when pedaling in the state where the auxiliary gear
is detached. However. the bicycle can travel forward through the change of
rotation direction of the pedal shaft by the auxiliary gear when pedaling rearward
while the auxiliary gear is attached.
On the other hand, according to the invention of Forster et al. (US Patent
No. 5,435,583), a gear box is installed on a pedal shaft, including two gears, two
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clutches therebetween and a bevel gear between two gears' teeth. Here, the bicycle
of this invention can travel like a general bicycle when pedaling while the clutch
is coupled with the right gear. However, the bicycle can travel forward through
the change of the rotation direction of the pedal shaft by the bevel gear when
5 pedaling rearward while the clutch is coupled with the left gear.
The above two inventions are meaningful in the aspect of the bi-directional
pedaling apparatus which can drive the bicycle forward by adopting a mid gear
when pedaling rearward. However, life span of the bi-directional pedaling
apparatus is shortened due to abrasion of a specific portion to which a force
10 required for changing the power direction is applied and there is inconvenience in
the operation of the apparatus for ch~n~ing power direction..
A bi-directional pedaling apparatus obtained by solving the above defects is
disclosed in Korean Patent Application No. 94-13391. According to this
application, a predetermined closed space is formed between one end of a pedal
15 shaft and a driving sprocket, and two one-directional ratchets are installed at the
outer and inner portions of the space.= Also, a ratchee wheel to which a plurality
planetary gears are rotatably set, and a chz~nging lever for controlling the locking
and unlocking of the outer one-directional ratchet are provided in the closed space.
The bi-directional pedaling mechanism of the bicycle in the bi-directional pedaling
20 apparatus is as follows.
When pedaling forward, the pedal, the ratchet wheel and the driving
sprocket integrally rotate to travel the bicycle forward. Meanwhile, the outer one-
directional ratchet instead of the inner one-directional ratchet functions by the
ch~n~ing lever when pedaling rearward. Here, there are two cases where the outer25 ratchet is locked and unlocked. First, when pedaling rearward while the outerratchet is locked, the plurality of planetary gears rotate around own shafts thereof,
so that the rotation direction of the pedal shaft is changed and then power from the
pedal shaft is transmitted to the driving sprocket, thereby driving the bicycle
forward. Second, when pedaling rearward while the outer ratchet is unlocked, the30 planetary gears rotate and simultaneously revolve around the pedal shaft in
cooperation with the ratchet wheel. As a result, power from the pedal shaft cannot
be tr~n~mitted to the driving sprocket, resl-lting in the idling of the pedal.
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According to the above-described Korean Patent Application No. 94-13391,
the concentration of force on a specific portion by the ch~n~ing of power direction
is prevented by dispersing the force using the plurality of planetary gears. Thus,
life span of the bi-directional pedaling apparatus is prolonged and the rotationS direction of the pedal shaft can be simply changed by using the ch~nging lever.
Also, the bi-directional pedaling apparatus can operate actively by adopting small
and precise parts.
However, in the above-described Korean Patent Application No. 94-13391,
mass production of the parts and assembling of each part are difficult and the bi-
10 directional pedaling apparatus cannot be attached directly to a conventional bicycle.so that the parts thereof should be improved partially. Also, each constituent part
may be broken by a re~erse-load caused when pulling back the bicycle.
Disclosure of the Invention
As an improved invention from the Korean Patent Application No. 94-
13391, it is an ob3ect of the present invention to provide an apparatus for changing
power direction for a bicycle which can be produced on a large scale by improving
the shape of each constituent part to be suitable for the simple rnanufacture and
assembling of the parts, which can be directly attached to a conventional bicycle
20 by irnproving parts and adopting an auxiliary means, and simult~neously which can
prevent the damage of parts caused by a reverse-load.
The apparatus for ch~nging power direction of the present invention includes
basic constituent elements for the bicycle1 such as a pedal shaft, a rear wheel, a
driving sprocket rotating with being formed on the pedal shaft. a driven sprocket
25 for tr~n~mitfing the driving force of the driving sprocket to the rear wheel~ and a
chain connecting the driving sprocket and the driven sprocken The basic
characteristic of the present invention is the "apparatus for ch~ngino. power
direction" formed in a closed space between the pedal shaft and the driving
sprocket. Here, the shape of parts used for constituting the apparatus for changing
30 power direction is a hollow cylindrical, ring- or gear-type.
The apparatus for ch~nginsJ power direction of the present invention, located
between the pedal shaft and the driving sprocket~ roughly includes a shaft housing~
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a ehange ring, a earrier, a sun gear and a sproeket cap. The functions of eaeh
eonstituents are as follows.
The shaft housing receiving the change ring, the carrier and the sun gear
supports the rotating pedal shaft and simultaneously controls the carrier by using
5 a plurality of pawls to be released from and inserted into a plurality of openings
formed at the inside of a rim of a right cap of the shaft housing when pedaling
rearward. The ehange ring releases and inserts the pawls from and into the shafthousing when pedaling rearward, and the carrier having ratchets at the outside and
inside of a left portion thereof, respeetively, and a plurality of planetary gears to
10 be rotatably set at a right portion rn~int~in.c or changes the direction of power from
the pedal shaft, thereby tr~n~mit~ing the power to a driving sprocket. The sun gear
transmits the driving force of the pedal shaft to the carrier while being coupled with
the pedal shaft. Also, the sprocket cap having. a gear at the right of the inside of
the rim thereof receives the power from the carrier to travel the bicycle forward at
15 all times regardless of forward and backward pedaling directions.
Therefore, the bicycle travels forward when pedaling forward and rearward
in the state where the apparatus for changing power direction is installed to the
bieyele. The apparatus for eh:~ngin~ power direction of the present invention asone of "bi-directional pedaling apparatus" is different from the conventional bi-
20 directional pedaling apparatus in the constituent parts and operating mechanism.In addition, according to the apparatus for changing power direction of the present
invention, the shapes of each constituent elements are optimized, thereby preventing
the concentration of load on a specific portion. Also, all constituent parts areintegrally formed, thereby simplifying the assembling process thereof. The
25 apparatus for changing power direction adopts a ch~n~in~ lever so as to easily
operate the same~ and an auxiliary ring which is for in~t~lling the apparatus for
ch~nging power direction to the conventional bicycle without the modification ofthe conventional bicycle.
30 Brief Description of the Drawin~s
FIG. 1 is a cross-seetional view of an apparatus for changing power
direction for a bicycle according to the present invention;
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FIG. 2 is an exploded perspective view o~ the apparatus for changing power
direction according to the present invention;
FIG. 3 is a right side view showing an example of a sun gear adopted in
the apparatus for ch~n~in~ power direction according to the present invention;
~ 5 FIG. 4A is an operational diagram of the apparatus for chan~ing power
direction, cut along line A-A of FIG. 1, when a change ring allows the release of
the first pawls from the openings of the shaft housing, and FIG. 4B is an
operational diagram of the apparatus for ch~nging power direction, cut along line
A-A of FIG. 1, when the change ring blocks the release of the first pawls from the
10 openings of the shaft housing;
FIG. 5 is a cross-sectional view of the apparatus for chan~ing power
direction. cut along line B-B of FIG. 1;
FIG. 6 is a cross-sectional view of the apparatus for changing power
direction according to a preferred embodiment of the present invention:
FIG 7 is a right side view of a shaft housing adopted in the apparatus for
changing power direction shown in FIG. 6;
FIG. 8 is a left side view of a carrier adopted in the apparatus for ch~ngin~
power direction shown in FIG. 6;
FIG. 9 is a left side view of a sprocket cap adopted in the apparatus for
20 ch~n~ing power direction shown in FIG. 6;
FIG. 10 is a right side view of a means for controlling a change ring
according to another embodiment of the present invention; and
FIG. 11 is a cross-sectional view when the apparatus for chan~ing power
direction is installed to a conventional bicycle according to still another embodiment
25 of the present invention.
Best mode for carrvin~ out the Invention
The present invention will be described in detail with reference to FIGS. 1
to 5.
As shown in FIGS. 1 and 2~ a shaft housing 30, a change ring 40. a carrier
50 and a sun gear 60 and a sprocket cap 70 are coupled in sequence on a pedal
shaft 20 of a bicycle to form an integrated apparatus for ch~nginsg power direction
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by attaching a fixing nut 90 to the outside of the sprocket cap 70. The structures
of each part and functions thereof will be described in sequence.
The shaft housing 30 supports the rotating pedal shaft 20, and has a plurality
of openings 31 at the inside of a rim of a right cap of the shaft housing 30, into
which a plurality of first pawls 32 are inserted. Also, a hole 33 to which a first
gear 81 for controlling the change ring 40 is fitted is formed at the sidewall of the
right cap. The shaft housing 30 having the above structure holds the change ring40, the carrier 50 and the sun gear 60 in sequence and simultaneously has a
function of rotating the carrier 50 or preventing the rotation of the carrier 50 by
10 using the first pawls 32 placed at the rim of the shaft housing 30 when pedaling
backward. Here, a spring is inserted between the shaft housing and the first pawls
32 to elastically holding the first pawls 32 in the openings 31.
The change ring 40 has a second gear 41 at one side thereof toward the
pedal shaft and a plurality of holes 42 at the surt'ace portion thereof. The second
15 gear 41 is in mesh with the first gear 81 to rotate the change ring 40 and the holes
42 is for permitting projection or shrink of the first pawls 32. The carrier 50
cannot rotate when the first pawls 32 are slid into the holes 42, and the carrier 50
can rotate when the change ring 40 blocks the first pawls 32 within the openings31 of the shaft housing 30.
Z0 The carrier 50~ having a hollow cylindrical shape, has a first ratchet 51 and
a second ratchet 52 at the outside and inside of a left portion, respectively and a
ring 53 having a plurality of holes at a right portion of the carrier 50, wherein the
right portion is integrally coupled with the left portion such that a plurality of
planetary gears 54 are rotatably set by a planetary gear shaft 55 in the ring 53.
25 The first ratchet 51 of the carrier 50 having the above structure is engaged with the
first pawls 32 of the shaft housing 30 and the second ratchet 52 is engaged withsecond pawls 62 of a sun gear 61 which will be explained later. On the other
hand, an inner portion of the planetary gears 54 of the carrier 50 is engaged with
a third gear 61 of the sun gear 60 and an outer portion thereof is engaged with a
fourth gear 71 formed at the inside of the sprocket cap 70 which will be explained
later.
The carrier 50 has a function of tr~ncmi~in~ the power from the pedal shaft
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20 to the sprocket cap 70 by m~int~ining or chzlngin5J the direction of power from
the pedal shaft 20, which is the most important in the present invention. The
planetary gears 54 of the carrier 50 disperses the force concentrated on a specific
portion by the change of the power direction and preferably, the number of
5 planetary gears is eight.
The sun gear 60, having a hollow cylindrical shape with steps, a left portion
with smaller diameter of the sun gear 60 has a plurality of openings 63 at the
outside thereof, to which the second pawls 62 are set, and the inside of the left
portion has a central opening having a hexagonal and spline-like shape such that the
10 left portion is integrally fixed to the pedal shaft 20. Also, a right portion with
larger diameter of the sun gear 60 has the third gear 61 at the outside thereof. In
the sun gear 60 having the above structure~ the second pawls 62 are enga~ed withthe second ratchet 52 of the carrier 50 and the third gear 61 is engaged with the
planetary gears 54 of the carrier 50. Here, the number of the second pawls is
15 preferably four.
Here, elasticity can be provided to the first and sccond pawls 32 and 62 by
the following methods. First, a coil or leaf spring is inserted beneath the pawls.
Second~ a flute is formed at each pawl with a predete~mined angle as shown in
FIG. 3 and then each pawl is connected by an annular spring 65 to provide a linear
20 tension.
Also, according to the present invention, the first pawls 32 and the change
ring 40 locate at the outside of the carrier 50 to control the carrier 50 only when
the pedal shaft 20 rotates reversely. Also, the second pawls 62 locate at the outside
of the sun gear 60 to allow one-directional rotation to the carrier 50 in the forward
25 rotation.
Since the sun gear 60 is integrally coupled with the pedal shaft 20, the sun
gear 60 transmits the power from the pedal shaft 20 to the carrier 50 while rotating
in the same direction as the rotation direction of the pedal shaft 20.
The sprocket cap 70 has the fourth gear 71 at the right of FIG. 1 of the
30 inside of the rim thereof, and a plurality of screws or ~rackets 72 at the outside of
the rim~ such that driving sprockets 73 having multiples steps is coupled thereto.
Also~ a ~earing 74 is fixed at the center of the sprocket cap 70, so that the sprocket
_
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cap 70 can freely rotate independent on the pedal shaft 20. The fourth gear 71 of
the sprocket cap 70 having the above structure is engaged with the planetary gears
54, thereby receiving power from the pedal shaft 20 via the carrier 50.
The sprocket cap 70 rotates forward at all times regardless of the rotation
direction of the pedal shaft 20.
Also, reference numerals 10, 11, 21 and 23 in FIG. 1 which are not
explained above represent a bicycle frame, a pedal shaft hub, a shaft bearing and
a washer, respectively.
When coupling the shaft housing 30 with the sprocket cap 70 on the pedal
10 shaft 20 of the bicycle~ a closed space is formed therebetween~ and the change ring
40. the carrier 50 and the sun gear 60 are assembled being engaged each other inthe space and a fixing nut 90 is fixed to the outside of the sprocket cap 70~ thereby
forrning an integrated apparatus for chan~ing power direction.
The integrated power changing apparatus is assembled by the following
15 sequence. First, the pedal shaft 20 is rotatably set in the shaft housing 30~ and then
the change ring 40~ the carrier 50, the sun gear 60 and the sprocket cap 70 are
assembled in sequence centering the pedal shaft 20 within the shaft housing 30.
Thcn, the fixing nut 90 is fixed to the outside of the sprocket cap 70, thereby
resulting in an integrated apparatus for changing power direction.
Also, a changing lever 80 for controlling the change ring 40 is set at the
sidewall of the shaft housing 30 and connected to the first gear 81. Thus~ the
ch~nPing Iever 80 moves the change ring 40 using the motion of the first gear 81.
The operation and effect of the apparatus for ch~n~ing power direction
according to the present invention having the above structure will be described
25 below.
~or convenience' sake in description, the operation of the present invention
will be described by classifying the operational method into ' forward traveling by
forward pedaling", ''forward traveling by rearward pedaling"~ and ''idling by
rearward pedaling".
First~ "forward traveling by forward pedaling" means that the bicycle
travels forward when driving pedal shaft 20 clockwise (this direction is referred
based on the case where the bicycle is viewed from the right with respect to the
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- _ g _
traveling direction of the bicycle, which is also applied to the following description)
as shown in FIGS. 4 and 5. Here, the power from the pedal shaft 20 is transmitted
as follows.
When driving the pedal shaft 20 clockwise, the sun gear 60 rotates
S clockwise in cooperation with the pedal shaft 20. Here, since the second pawls 62
are engaged with the second latch 52, the carrier 50 rotates in the same direction
as the pedal shaft 20. Accordingly, the planetary gears 54 do not rotate for
themselves while the fourth gear 71 of the sprocket cap 70 which are engaged with
the planetary gears 54 rotates clockwise. Thus, the pedal shaft 20 and the sprocket
10 cap 70 rotate in the same direction each other. thereby traveling the bicycle forward.
Second. 'forward traveling by rearward pedaling" means that the bicycle
travels forward when driving pedal shaft 20 counterclockwise. Here, the power
from the pedal shaft 20 is tr~n~mitted as follows. For this operation, the first pawls
15 32 and the first ratchet 51 should be engaged each other by controlling the change
ring 40 as shown in FIG. 4A.
When driving the pedal shaft 20 counterclockwise, the sun gear 60 rotates
counterclockwise in cooperation with the pedal shaft 20. Here~ since the second
pawls 62 is slid over the second latch 52, it is impossible to transmit power to the
20 carrier 50. Meanwhile, as shown in FIG. 5, the third gear 61 of the sun gear 60
transmits power to the planetary gears 54 which are engaged with the sun gear 60~
thereby rotating the planetary gears 54 clockwise. Here, the rotation of the
planetary gears 54 provides a force for rotating the carrier 50 which is integrally
coupled with the planetary gears 54. However, the carrier 50 cannot rotate
25 counterclockwise since the first pawls 32 are engaged with the first ratchet 51 of
the carrier 50 as shown in FIG. 4A. Thus, the sprocket cap 70 engaged with the
planetary gears 54 rotates clockwise while only the planetary gears 54 rotate asshown in FIG. 5. By this operation. direction of the drivin_ t'orce applied to the
pedal shaft 2V in the counterclockwise is changed via the apparatus for ch:~ngin g
30 power direction of the present invention, thereby rotating the sprocket cap 70
clockwise.
Third, ''idling by rearward pedaling" means that the bicycle cannot travel
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since the power is not transmitted to the sprocket cap 70 while only idling occurs
when driving pedal shaft 20 counterclockwise. Here, the power from the pedal
shaft 20 is tr~n~mi~f~d as follows. For this operation, the first pawls 32 of the shaft
housing 30 and the first ratchet 51 of the carrier 50 should not be engaged each5 other by controlling the change ring 40 as shown in FIG. 4B.
Here, the power transmit process for the above operation is the same as
those of "forward traveling by rearward pedaling" to the step where
counterclockwise force is applied to the carrier 50 by the planetary gears 54, except
that the carrier 50 itself revolves around the pedal shaft 20 counterclockwise while
10 the planetary gears 54 rotate since the first pawls 32 are not engaged with the first
ratchet 5~. Thus, power from the pedal shaft 20 is transmitted only to the carrier
50. not to the sprocket CAp 70. so that the bicyclc carmot travel.
The idling by rearward pedaling in the general bicycle is different from the
''idling by rearward pedaling'~ by the apparatus for changing power direction of the
15 present invention in the following aspects. That is, in the idling by rearward
pedaling in the general bicycle~ the driving sprocket and the chain reversel~ rotate
in cooperation with the pedal shaft. However, the driving sprocket and the chaindo not rotate in the present invention.
As described above, the apparatus of the present invention as one of bi-
20 directional forward traveling apparatus" transmits power in the different mannerfrom the conventional apparatus by adopting new parts. Also, since the shape of
each constituent part is optimized, concentration of load on a specific portion is
prevented. Also, each part is integrated, so that the assembling can be performed
simply. In addition, a lever is attached to simplify the operation of the apparatus
25 and ehe structure of the shaft housing is modified to be directly attachable to the
conventional bicycle, which will be explained in the following embodiments of the
present invention.
Hereinafter, the first. second and third embodiments of the present invention
will be described based on the above present invention. In the first embodiment,30 the locations of an one-directional ratchet used for the forward rotation and a
ratchet for controlling the reverse rotation are shifted each other. In the second
embodiment~ the changing lever is replaced by a wire. Also. in the third
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embodirnent, the shape of the shaft housing is modified such that the apparatus for
changing power direction can be attached directly without modification of the
conventional bicycle.
5 < Embodiment 1 >
Referring to FIGS. 6 to 9, a basic characteristic of this embodiment is to
change the locations of an one-directional ratchet used for the forward rotation and
a ratchet for controlling the reverse rotation. That is, the location of the ratchet
used for the forward rotation is shifted from the inside of the carrier to the outside
10 thereof while the location of the ratchet used for controlling the reverse rotation is
shifted viceversa.
For shifting the locations of the above two ratchets. each constituent part is
manufactured with different shape from the above-described present invention.
However, the number of parts are the same as the above present invention and the15 operation thereof is similar to the above present invention. The shape of the modified parts will be described as follows.
As shown in FIGS. 6 and 7, a shaft housing 130 has a hollow cylindrical
protrusion at the right thereof and a plurality of openings 131 at the outside thereof,
into which a plurality of third pawls 132 are inserted. The shaft housing 130 has
20 a circular plate type sidewall and a hole 133 for receiving the first gear 81 of the
above present invention at a position which is near the pedal shaft 120 comparedwith the hole 33 of the above present invention since the shaft huusing 130 is
obtained by removing the rim of the shaft housing 30.
A change ring 140 of this embodiment is different from the change ring 40
25 of the above present invention in the aspect in that a fifth gear 141 is forrned at one
side thereof toward the o~tside of the pedal shaft 120. The change ring 140 locates
between the third pawls 132 and the third ratchet 151 of the carrier 150.
As shown in FIGS. 6 and 8, a carrier 150 of this embodiment has a plurality
of opening 153 into which a plurality of fourth pawls 152 are inserted at the outside
of a left portion of the carrier 150 and a third ratchet 151 at the inside of the left
portion. Also~ a right portion of the carrier 150 is the same as that of the carrier
50 of the above present invention. In the carrier 150 having the above structure,
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the fourth pawls 152 are engaged with a fourth latch 172 of a sprocket cap 170 and
the third ratchet 151 is engaged with the third pawls 132 of the shaft housing 130.
A sun gear 160 of this embodiment has an inside fixed to the pedal shaft
160 and an outside having a sixth gear 161 which is engaged only with a plurality
of planetary gears 154.
Also, as shown in FIGS. 6 and 9, the sprocket cap 170 has a seventh gear
171 at the right of FIG. 6 of the inside of the rim and a fourth ratchet 172 at the
left thereof. Thus, the seventh gear 171 is engaged with the planetary gears 154of the carrier 150 and the fourth ratchet 172 is engaged with the fourth pawls 152
10 of the carrier 150.
The other parts are the same as those of the above present invention. Also.
in ~IGS. 6 to 9, reference numeral 110 represents a bicycle frame~ reference
numeral 111 represents a pedal shaft hub, reference numeral 153 represenes a
carrier ring, reference numeral 155 represents a shaft of the planetary gears. and
15 reference numeral 173 represents a sprocket bracket.
The operation and effect of this embodiment having the above structure will
be described below.
First, the "forward traveling by forward pedaling" is performed by the
following mechanism. When the pedal shaft 120 rotates clockwise, the sun gear
20 160 rotates in the sarne direction as the pedal shaft 120 and the planetary gears 154
rotates counterclockwise. However, the carrier 150 itself rotates clockwise in adifferent rotating rate from that of the pedal shaft 120 and the fourth pawls 152 of
the carrier 150 is engaged with the fourth ratchet 172 of the sprocket cap 170,
thereby rotating the sprocket cap 170 clockwise.
Next~ the "forward traveling by rearward pedaling" is performed when the
third pawls 132 of the shaft housing 130 are engaged with the third ratchet 151 of
the carrier 150 after the change ring 140 allows the release of the third pawls 132
from the holes of the change ring 140. That is, the forward traveling by rearward
pedaling is performed while the carrier 150 is fixed. Thus, the planetary gears 154
30 change the direction of power from the sun gear 160 while rotating around their
own shafts~ thereby providing the power to the sprocket cap 170 clockwise.
Finally, the "idling by rearward pedaling'' is performed by the following
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mechanism. The change ring 140 blocks the release of the third pawls 132 frorn
the openings of the shaft housing, so that the carrier 150 rotates in the same
direction as the pedal shaft 120. As a result, the power from the sun gear 160
cannot be transmitted to the sproclcet cap ~70.
< Embodiment 2 >
The second embodiment of the present invention relates to the controlling
~ of the change ring 40.
The change ring 40 of the above present invention releases and blocks the
first pawls 32 by using the first gear 81 (see FIGS. 1 and 2) formed at the sidewall
of the shaft housing 30. In order to control the first gear ~1 formed in the shaft
housing 30, the shaft housing 30 should be drilled to form a hole 33 through which
the changing lever 80 is installed from the outside. When rotating the changing
lever 80 in the front and back, the first gear gl rotates in cooperation with the
changing lever 80 and the change ring 40 engaged with the first gear 81 rotates in
the same direction as the ch~nPing lever 80, thereby releasing and blocking the first
pawls 32.
The above changing lever 80 is protruded to the outside of the shaft housing
30, so that the protruded ch~nging lever 80 prevents the successful coupling of the
apparatus for ch~nginP power direction to the conventional bicycle.
Thus, the second embodiment is to improve the above defect. Here, a steel
wire is adopted instead of the changing lever to easily connect the apparatus for
changing power direction to the conventional bicycle, thereby controlling the
change ring.
As shown in FIG. 10, a means for controlling a change ring 43 of the
second embodiment has a loop 44 at one end of the change ring 43 having a
plurality of holes 45. Here~ the loop 44 is for connecting a steel wire 46 from the
outside of the shaft housing 30 via a hole 33. thereby controlling the change ring
43. That is, the change ring 43 blocks the first pawls 32 when the steel wire ispulled, and the change ring 43 releases the first pawls 32 when the steel wire 46
is pushed.
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< Embodiment 3 >
The third embodiment relates to the shaft housing 30, wherein the shape of
the shaft housing 30 is modified to a shaped which is suitable for directly attaching
the apparatus for ch~nging power direction of the present invention to the
5 conventional bicycle without the modification of the conventional bicycle.
FIG. 11 shows the state where the apparatus for ch~n~ing power direction
of the present invention is installed to the conventional bicycle. In the third
embodiment, appearance of the shaft housing 30 having a hollow cylindrical shapeis improved.
A shaft housing 34 of this embodiment has a multiple-stepped appearance.
That is, the cylindrical shaft housing 34 is multiple-stepped to the left in sequence,
wherein the diameter of the left side is smaller than that of the right side of the
shaft housing 34. Also. a connection tube 15 is adopted to provide compatibilitywhen conn~cting the apparatus for ch~n5gino power direction to the pedal hub 11 of
15 the conventional bicycle. A right-handed screw 35 is formed at the outside of the
connection tube 15. Also~ the outer diameter of the connection tube 35 is the same
as that of the pedal hub 11 and the inner diameter thereof is the samc as the outer
diameter of the shaft housing 34. On the other hand, an additional nut 36 is
manufactured as follows. A left-handed screw 37 is formed at the outside of the
20 nut 36 and a left inside of the nut 36 is processed to have a taper 38.
Accordingly, the shaft housing 34 is installed to the conventional bicycle by
the following procedures. First, the connection tube is coupled with the pedal hub
11 using the right-handed screw 35 and the connection t~lbe 15 is coupled with the
shaft housing 34 through a spline coupling. Then, the nut 36 is screwed at the
25 opposite side through left-handed screw coupling by the left-handed screw 37 and
then the assembling is completed using a washer 39.
When connecting the apparatus for changing power direction of this
embodiment to the conventional bicycle. the shaft housing 34 is much tightly
connected to the pedal hub 11 even though a reverse load caused by the pulling
30 back of the bicycle is applied to the apparatus for ch~n~ing power direction of the
present invention via the driving sprocket. That is, as the reverse load applied to
the apparatus for changing power direction increases, the shaft housing 34 is much
CA 02237112 1998-0~-07
WO 97/Z1587 PCT/KR96/00236
- 15 -
tightly connected to the pedal hub 11 by the taper 38 formed at the inside of the nut
36 since the right-handed screw 35 of the connection tube 15 and the left-handedscrew 37 of the nut 36 are coupled in the opposite direction each other.
Also, the shaft housing 30 and the pedal hub 11 may be tightly coupled each
S other by processing a contact portion between the sides of the shaft housing 30 and
the pedal hub 11 to have a ridge and valley-type.
~ Industrial Applicability
Therefore, the bicycle travels forward when pedaling forward and rearward
10 in the state where the apparatus for changing power direction is installed to the
bicycle. Also, an idling may occur if required when pedaling rearward in the state
where the apparatus for ch~nging power direction is installed to the bicycle. The
apparatus for changing power direction of the present invention as one of "bi-
directional pedaling apparatus" is different from the conventional bi-directional
15 pedaling apparatus in the constituent parts and operating mechanism. In addition,
according to the apparatus for chan~ing power direction of the present invention,
the shapes of each constituent elements are optimized~ thereby preventing the
concentration of load on a specific portion. Also, all constituent parts are integrally
formed, thereby simplifying the assembling process thereof. The apparatus for
2~ h~nging power direction adopts a ch~nging lever so as to easily operate the same,
and an auxiliary ring which is for installing the apparatus for ch~nging power
direction to the conventional bicycle without the modification of the conventional
bicycle.
