U.S. patent application number 12/843476 was filed with the patent office on 2010-12-09 for power assist system and method for a vehicle.
Invention is credited to Harold Spanski, Roberta Spanski.
Application Number | 20100307851 12/843476 |
Document ID | / |
Family ID | 39609240 |
Filed Date | 2010-12-09 |
United States Patent
Application |
20100307851 |
Kind Code |
A1 |
Spanski; Harold ; et
al. |
December 9, 2010 |
POWER ASSIST SYSTEM AND METHOD FOR A VEHICLE
Abstract
A power-assist system and method for a bicycle, comprising three
main sections, namely: a motor section, a speed-reducing section,
and a power-assist section. It is capable of operating in four
modes, namely: a) a power-assist pedaling mode (where the bicycle
rider is pedaling to supply power and the power-assist section is
also providing power); b) a pedal only mode (where power is
supplied solely by pedaling the bicycle; c) a power-assist only
mode (where the bicycle rider is not providing any power by
pedaling, and all the power is supplied by the power-output
section); and d) a coasting no-power mode where the bicycle is
traveling with the pedal section stationary, and no power is being
delivered either by the pedal section or the power-assist drive
system.
Inventors: |
Spanski; Harold; (Lynden,
WA) ; Spanski; Roberta; (Lynden, WA) |
Correspondence
Address: |
HUGHES LAW FIRM, PLLC
5160 Industrial Place,#107
Ferndale
WA
98248-7819
US
|
Family ID: |
39609240 |
Appl. No.: |
12/843476 |
Filed: |
July 26, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11963619 |
Dec 21, 2007 |
7770682 |
|
|
12843476 |
|
|
|
|
60871396 |
Dec 21, 2006 |
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Current U.S.
Class: |
180/206.4 |
Current CPC
Class: |
B62K 11/00 20130101;
B62M 6/20 20130101 |
Class at
Publication: |
180/207 |
International
Class: |
B62M 23/02 20100101
B62M023/02 |
Claims
1. A motor assist power system for a bicycle which has, at least
one drive wheel, a second wheel, and a bicycle frame with front and
rear ends, said system comprising: a) a pedal section comprising a
crank shaft connecting a plurality of pedal members, a crank
housing in which the crank shaft is located; b) a sprocket section
coupled to the pedal section having a power drive connection to the
drive wheel; c) a power-assist drive section comprising a power
assist drive member concentrically mounted around and mechanically
coupled to said crank shaft; d) a motor positioned directly forward
of the second wheel and the crank housing, wherein the motor is
mechanically coupled to the power-assist drive section; e) an
overrunning drive connection coupled to the power-assist drive
connection; whereby said bicycle is configured to operate in four
operating modes, namely: i a power-assist mode where a bicycle
rider is pedaling to supply power, and the motor through the
power-assist section is providing additional power; ii a pedal-only
mode where power is being supplied solely by pedaling the bicycle;
iii the power-assist-only mode where the bicycle rider is not
providing power by pedaling, but power is supplied by the motor
through the power output section; iv a coasting no-power mode where
the bicycle is traveling with the pedal section stationary, and no
power is being supplied by either the pedal section or the
power-assist drive section.
2. The motor assist power system as recited in claim 1 wherein the
power drive is a chain-and-sprocket power drive.
3. The motor assist power system as recited in claim 1 further
comprising a speed reducing section positioned between and
mechanically coupled between the motor and the overrunning drive
connection.
4. The motor assist power system as recited in claim 1 wherein the
speed reducing section comprises an eccentric gear cluster.
5. The motor assist power system as recited in claim 4 wherein the
speed reducing section comprises epicyclical eccentric gear cluster
further comprising a power input component and a power output
component wherein the power input component is structurally and
rotationally co-axial with the power output component.
6. The motor assist power system as recited in claim 1 wherein the
motor is a gasoline powered motor.
7. The motor assist power system as recited in claim 1 wherein the
motor is an electrically powered motor.
8. The motor assist power system as recited in claim 7 further
comprising a gasoline powered motor.
9. The motor assist power system as recited in claim 1 wherein the
motor is positioned laterally between the second wheel and the
crank housing.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 11/963,619 incorporated herein by reference
which claims priority benefit of U.S. Provisional Application Ser.
No. 60/871,396, filed Dec. 21, 2006, and U.S. Pat. No. 6,976,551 B2
which is also incorporated herein by reference.
FIELD OF THE DISCLOSURE
[0002] The present invention relates to a power assist system for a
pedal powered bicycle or the like, and also a method relating to
the same.
SUMMARY OF THE INVENTION
[0003] The present invention relates to a power-assist apparatus
and method that is adapted for use in a bicycle or the like, and
also to the combination of the bicycle or the like and the
power-assist method and apparatus.
[0004] In the embodiments of the present invention there are three
sections, and namely a motor section, a speed-reducing section
having an operative connection to the motor section, and a
power-assist section.
[0005] There are four operating modes, and these are as follows:
[0006] i. the power-assist pedaling mode (where the bicycle rider
is pedaling to supply power, and the power-assist section is
providing power); [0007] ii. the pedal only mode (where power is
being supplied solely by pedaling the bicycle); [0008] iii. the
power-assist only mode (where the bicycle rider is not providing
any power by pedaling, and the power is supplied by the power-out
section); and [0009] iv. a coasting, no-power mode (where the
bicycle is traveling with the pedal section stationary, and no
power is being delivered either by the pedal section or the
power-assist drive system).
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side elevational view of a portion of a bicycle
having a first embodiment of a power-assist system of the present
invention installed thereon;
[0011] FIG. 2 is a sectional view taken primarily along line 2-2
showing the two main sections of the power assist system of FIG. 1
connected to one another in their operating environment;
[0012] FIG. 3 is a sectional view of the speed reducing power
section of the power assist apparatus of FIG. 1;
[0013] FIG. 4 is a sectional view of the power assist output
section of FIG. 1;
[0014] FIG. 5 is a side sectional view of the power assist shaft
assembly of the power assist output section;
[0015] FIG. 6 is an exploded sectional view of the same components
of FIG. 5;
[0016] FIG. 7 is an isometric view of a modified arrangement of
certain components of the speed reducing gear section of FIG.
3;
[0017] FIG. 8 is an isometric view of a lower part of a bicycle
incorporating the components of a second embodiment of the present
invention;
[0018] FIG. 9 is a cross-sectional view that is taken from a plane
extending through two axes of rotation of components of the second
embodiment of the present invention; and
[0019] FIG. 10 is a cross-sectional view of two components of a
third embodiment of the present invention, similar to the view
taken in FIG. 9.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0020] In FIG. 1, there is shown a bicycle 10 which comprises a
frame 12, front (second) and rear wheels, with only the rear wheel
14 being shown, and a frame mounting sleeve 16 where a handlebar
(not shown) is located, and a drive section 22, comprising a pedal
section 24 comprising a crank housing 25, and a sprocket section
26. The sprocket section in turn comprises a forward sprocket
section 28, a drive chain 30, and a rear sprocket section 32.
[0021] The frame 12 in turn comprises a central frame section 34,
which in turn comprises an upper horizontal frame member 36, a
front downwardly and rearwardly slanting frame member 38, and a
back frame member 40. The frame members 36 and 38 meet at a front
connecting location 42 to connect to the mounting sleeve 16 of the
steering column; the upper frame member 36 and the back frame
member 40 meet at a back connecting location 44; and the front
lower frame member 38 and the back frame member 40 connect to the
crank housing 25 at a lower connecting location 46.
[0022] There is also a rear frame section 48 comprising an upper
forked frame member 50 and a lower forked frame member 52. The rear
ends of these two frame members 50 and 52 meet at the location of
the rear axial sprocket section 32. The upper forward end portion
of the upper frame member 50 connects to the back frame member 40
at approximately the connecting location 44. The forward end of the
lower rear frame member 52 has a connection to the central frame
section 34 at the lower connecting location 46. There is a seat 53
supported by a seat post 54 extending upwardly from the bottom of
the back frame member 40, and as is common in the prior art, this
seat post 54 can comprise a separate post member telescopically
mounted in the back frame member 40.
[0023] It is to be understood that the components described above
already exist in the prior art. The present invention is designed
so that it can be readily adapted to be incorporated in a typical
bicycle configuration, such as described above, as well as other
bicycle configurations.
[0024] With further reference to FIG. 1, there are shown the main
components of the power-assist apparatus 60 of the present
invention. These comprise three main sections, namely: a motor
section 62, a speed-reducing section which in this embodiment is in
the form of a speed reducing gear section 64, and a power-assist
output section 66 (hereinafter called the "power-assist section
66").
[0025] It is believed that a clearer understanding of the present
invention will be achieved by first identifying the four main
operating modes of the apparatus of the present invention. After
that, there will be a more detailed description of these components
and their operation. The main operating modes are as follows:
[0026] a) the power-assist pedaling mode (where the bicycle rider
is pedaling to supply power, and the power-assist section 66 is
providing power); [0027] b) the pedal only mode (where power is
being supplied solely by pedaling the bicycle); [0028] c) the
power-assist only mode (where the bicycle rider is not providing
any power by pedaling, and all the power is supplied by the power
output section; and [0029] d) a coasting no-power mode where the
bicycle is traveling with the pedal section stationary, and no
power is being delivered either by the pedal section or the
power-assist drive system.
[0030] The motor section 62 comprises a motor 68 mounted by a clamp
69 to an upper mounting plate 70, and having a power output shaft
71 (shown in FIG. 3) which is contained in a cylindrical mounting
member 72 that extends from the motor section 62 to the speed
reducing gear section 64 (see FIG. 1) so that the drive shaft
extends from the motor section 62 to the speed reducing gear
section 64. A connecting end portion of this drive shaft is shown
at 71 (see FIG. 3). In this embodiment, the motor 68 is a gasoline
powered motor having a power output of, for example, 1 to 1.5
horsepower, and capable of operating at 4000 RPM, and possibly as
high as 8000 RPM, or higher.
[0031] Alternatively, the motor 68 could be an electric motor, also
capable of operating at 4000 RPM or possibly higher, or other types
of motors. Further, the motor 68 could be mounted to the bicycle
frame 12 directly. Within the broader scope, the RPM could
conceivably range from 1000, 1500, 2000, 2500, 3000, 3500, or 4000,
up to higher ranges such as 4500, 5000, 5500, 6000, 7000, 8000,
9000, 10,000, 11,000, or 12,000 RPM. The horsepower could obviously
vary from one-half (or below one-half), three-quarters, 1.0, 1.75,
2.0, 2.5, or 3.0 or higher. There are design options available to
possibly meet certain applications or requirements, or possibly to
take advantage of improvement in power sources, including electric
power, etc. Since these alternative power sources are already known
to those skilled in that art, these will not be discussed in this
text.
[0032] The speed-reducing gear section 64 will now be described
with reference to FIG. 3. The speed-reducing gear section 64
comprises a speed reducing gear section housing 76, a power input
component 78, a speed-reducing gear assembly 80, and a power output
component 82. The housing 76 in turn comprises an input end 84 at
which there is an input housing section 86, an output end 88 having
an output housing section 90 and an intermediate housing section
91. These two housing sections 86 and 91 are connected to one
another at perimeter portions thereof by a first set of bolts 93,
and the intermediate housing section 91 is connected to the rear
housing section 90 at outer perimeter bolt locations at 101. The
housing 76 has a longitudinal center axis 94.
[0033] In the following description, the term "rear" shall denote a
location at, or in proximity to, the input housing section 86, and
the term "front" or "forward" shall denote a location at, or in
proximity to, the output housing section 90.
[0034] The rear housing section 86 has a rear end plate 96 which
has a frustoconical configuration. The output housing section 90
comprises a disc shaped front end plate 100, having a perimeter
portion 102, extending from the perimeter of the end plate 100
rearwardly. There are additional bolts 101 that extend through the
forward perimeter portion 102 to connect to a forward perimeter
portion 103 of the intermediate housing section 91. Positioned
between the two perimeter portions 103 and 102 is a stationary ring
gear flange 104. The additional bolts 101 extend through the ring
gear flange 104 and the connecting plate 169 (to be discussed later
in this text) to attach it rigidly to the housing 76.
[0035] The power input component 78 comprises a pinion gear 106
which is connected to the end portion of the drive shaft 71 that is
driven directly from the motor section 64. The pinion gear 106
engages a matching input drive gear 108 which connects to a rear
input shaft section 114 of a longitudinally extending power input
shaft 116 rotatably mounted about the longitudinal axis 94. The
shaft 116 also comprises a forward output shaft section 122 that
connects to the forward end portion of the rear shaft section 114.
The forward portion of the input shaft section 114 is supported in
the intermediate housing section 91 by a rear end bearing 117. A
counterweight 118 is connected to the front end portion of the rear
shaft section 114. The front end of the forward shaft section 122
is mounted in a front end bearing 124. A rear seal 125 is
positioned between the input shaft section 114 of the shaft 116 and
the intermediate housing section 91.
[0036] At the longitudinal center portion of the shaft 116, the
shaft 116 is formed with a cylindrically shaped eccentric drive
portion 128 having an outer cylindrical surface 130 which is
concentric with an offset center axis 132 of the eccentric drive
portion 128. As the shaft 116 rotates, the offset center axis 132
orbits about the longitudinal center axis 94.
[0037] The aforementioned speed-reducing gear assembly 80 comprises
a cluster gear section 136 mounted by front and rear bearings 138
and 140 to the eccentric drive portion 128 so as to be concentric
with the offset center axis 132. The cluster gear section 136
comprises a first rear gear portion 142 and a second forward gear
portion 144. The first gear portion 142 is positioned within the
earlier mentioned surrounding fixed ring gear 104 mounted in the
perimeter portion 103 of the rear housing 76. The first rear gear
portion 142 has a pitch diameter moderately smaller than the inside
pitch diameter of the fixed ring gear 104. With the first gear
portion 142 being concentric with the offset axis 132, and with the
first gear portion 142 engaging the ring gear 104, as the shaft 116
rotates about the longitudinal axis 94, the gear portion 142 has a
rotating motion about the offset axis 132 and also has an orbital
movement about the longitudinal axis 94.
[0038] Adjacent to, and just forwardly of, the fixed ring gear 104,
there is a rotatably mounted ring gear 148 mounted within a bearing
150 which surrounds the ring gear 148 and is positioned within a
forward cylindrical extension 152 of the fixed ring gear 104.
Positioned within this rotatably mounted ring gear 148 is the
aforementioned forward cluster gear portion 144. The outside
diameter of this forward cluster gear portion 144 is moderately
smaller than the inside diameter of the rotatable ring gear 148.
Thus, with the first and second gear portions 142 and 144 being
fixedly connected with one another, the rotation of the cluster
gear section 136 causes the rotation of the rotatable ring gear 148
which provides the power output. The diameters of the first and
second gear portions 142 and 144 and the inside diameters of the
ring gears 146 and 148 are selected so that the speed reduction
ratio is in the range of about 45:1 or 50:1, or, more broadly,
possibly as low as 40:1, 35:1, or 30:1, or conceivably lower, or
possibly as high as 55:1, 60:1, 65:1, 75:1, 80:1, 90:1, 100:1,
125:1, 150:1, 200:1, or higher.
[0039] The aforementioned output component 82 comprises a forward
drive member 157 that is a forward extension of the power output
ring gear 148 and fixedly connected thereto. There is an output
bearing member 162 mounting the output drive member 157. The front
end of the forward shaft section 122 is supported by means of the
aforementioned bearing 124.
[0040] The final output member is an output set of sprocket teeth
164 which are mounted to the output drive member 157 so as to be
positioned around, and connected to, the drive member portion 157.
The upper end of a drive chain 168 (shown schematically as a broken
line in FIG. 2) engages the output sprocket teeth 164 and extends
downwardly therefrom to come into drive engagement with the
power-assist output section 66. There is a connecting plate 169
which was discussed earlier in this text and which has as an upper
circular end portion that is adjacent to the ring gear flange 104.
This plate 169 extends downwardly and connects to the power assist
section 66. There is a downward extension 171 of the end plate 100
of the housing 76 that is formed as a cover to fit against the
plate 169 to enclose the drive chain 168. The perimeter portion 102
of the forward output housing section 90 is provided with through
openings to accommodate the drive chain 168 so that it can extend
through the housing section 90 to connect to the power-assist
output section 66.
[0041] We will now provide a more detailed description of the
power-assist output section 66. However, before doing so, it would
be helpful to review briefly the existing drive section 22 which
exists in the bicycle prior to installation of the power assist
apparatus of the present embodiment in the bicycle. As described
briefly above in this text, this drive section 22 comprises the
pedal section 24 and the drive sprocket section 26 that in turn
comprises the forward sprocket section 28, a drive chain 30, and
the rear sprocket section 32. In incorporating the present
invention in a conventional bicycle, the existing power section
remains substantially the same, but with a few modifications.
[0042] Reference is now made to FIGS. 2 and 4 to proceed to a
description of the power-assist output section 66 of this
embodiment of the invention. There is the existing crank housing 25
which is part of the existing bicycle and this remains as it is.
Then as part of the present embodiment of the invention there is
added to the bicycle a pedal section crank shaft 170 that is
positioned in the crank housing 25. There are right and left crank
arms, inner portions of which are shown in FIG. 2 at 172 and 174,
respectively, and each of these crank arms has a foot pedal (not
shown except in FIG. 1) which is attached to the outer end of its
crank arm 172 or 174. The left crank arm 174 connects to the left
end of the crank shaft 170. The right end of the crankshaft 170
connects to a hub 178 (see FIG. 2) which in turn engages a pedal
driven freewheeling clutch 180 shown somewhat schematically as a
rectangular cross section of the clutch 180. The clutch 180 has a
threaded drive connection to the hub 178 and a second freewheeling
connection to the forward sprocket section 28.
[0043] The freewheeling clutch 180 is arranged so that when the
bicycle rider is pedaling to move the bicycle forward under power,
the two clutch portions of the clutch 180 engage one another in
drive relationship to drive the sprocket section 28. However, when
the forward sprocket section 28 is rotating faster than the crank
shaft 170 or rotating while the pedal section 24 (and the crank
shaft 170) is stationary, the freewheeling clutch portion will
rotate freely with the sprocket 28.
[0044] Near the left end of the pedal crank shaft 170, there is a
second freewheeling clutch 188 which connects to the left end of a
power-assist shaft section 190. This power-assist shaft section 190
has a tubular generally cylindrical configuration and it
concentrically surrounds the crank shaft 170. The power-assist
shaft section 190 and the crank shaft 170 collectively comprise a
shaft assembly 191. The clutch 188 has a first clutch portion which
is provided with sprocket teeth 194 that engage the aforementioned
drive chain 168 so that the first clutch portion functions as a
sprocket 194. The second inner portion of the clutch 188 is
freewheeling.
[0045] The clutch 188 is a "left handed version" of the clutch 180
so that when the speed reducing gear section 64 is not being driven
by the motor section 62, and the person is pedaling the bicycle,
the clutch 188 is free wheeling, but when the second sprocket
portion 194 is driven by the speed reducing gear section 164, the
clutch 188 is in its engaged power supplying mode of operation. The
second freewheeling portion of the clutch 188 has a second drive
connection to the outer surface of the left end portion 198 of the
power-assist shaft 190. The left end portion of the power-assist
shaft 190 section has a diameter greater than that of the main
portion of the shaft 190. A bearing member 200 is positioned in
this left end portion 198 to provide support for the left end of
the crank shaft 170.
[0046] Positioned concentrically around the shaft section 190
immediately to the right of the clutch 188 and fixedly connected by
threads to the left end of the crank housing 25 is an adapter
member or connecting adapter 204 to connect the connecting plate
169 to the crank housing 25. This adaptor 204 comprises a radially
outwardly extending perimeter flange 206 and a forwardly extending
cylindrical flange 208, supporting a bearing 209. These two flanges
206 and 208 engage the aforementioned connecting plate 169 which
has a through opening by which it is mounted by bolts 207 to the
flange 206. The adapter member 204 also has a rearwardly extending
cylindrical flange 210 which has outer threads to enable it to
thread into the left end of the crank housing 25.
[0047] For convenience of illustration, only the inner connecting
portions of the two crank arms 172 and 174 are shown only in FIG. 2
and not in FIG. 4. To summarize briefly, the power-assist shaft
section 190 has a "freewheeling" connection to the drive connection
to the speed reducing gear section 64. The crank shaft 170 has at
its left end a connection to the left crank arm 72. However, the
right end of the crank shaft 170 has a drive connection to the
inner portion of the right crank arm 174.
[0048] At the right end of the crank housing 25, there is a right
adapter member 212, which comprises a cylindrical connecting
portion 214 which has external threads which engage the inner
threaded surface portion of the right end portion of the crank
housing 25. The adapter member 212 also comprises a radially
extending flange portion 216 that connects to a rearwardly
extending cylindrical flange portion 218 within which is positioned
a bearing member 219 to provide support for the right end portion
of the power-assist shaft 190.
[0049] Connected to the right end of the power-assist shaft section
190, there is a sprocket connecting member 220 (also called a
carrier flange 220) which comprises a forwardly extending
cylindrical connecting member 224 having interior threads to engage
the right end portion of the power-assist shaft section 190. This
carrier flange 220 has an outwardly stepped portion 226 outside of
which is the aforementioned outer bearing member 219 to provide
support for the right end portion of the power-assist shaft
190.
[0050] The sprocket connecting member 220 further comprises a
sprocket mounting portion 230 which is fixedly attached to the
carrier flange 220. Additional sprockets could also be mounted to
the member 230.
[0051] Let us turn our attention now to the power-assist shaft 190
which was mentioned earlier in this text. One of the potential
problems in installing the system of this embodiment in a bicycle
is that the length of the crank housing 25 may be different for
different models of bicycles. This creates a problem in the
preloading of bearings or interference. This power-assist shaft
section 190 is designed to alleviate this problem.
[0052] To discuss the power-assist shaft section 190 further,
reference is made to FIG. 5 and FIG. 6. This power-assist shaft
section 190 comprises the aforementioned right carrier flange 220,
and also a left drive sleeve section 240, and a middle position
adjustment section 242 (also called the adjustment sleeve 242).
[0053] As indicated previously in this text, the carrier flange 220
comprises the previously mentioned cylindrically shaped connecting
collar portion 224. This collar section 224 has a set of interior
left hand threads 244.
[0054] The main drive sleeve section 240 has at its left end
portion as previously mentioned, a left end power input 198 which
has external left hand threads 246 that engage the inner section of
the left clutch overrun member 188. As indicated previously in this
text, the left clutch member 188 connects to, and is driven from,
the power-assist speed reducing gear section 64, and the power from
this left clutch 188 is transmitted through the power-assist shaft
190 to a right hand location to provide power to the carrier flange
220.
[0055] This main drive sleeve section 240 has three sets of
external threads, namely the above-mentioned left hand threads 246
of the left end power output, a second central position set of
right hand threads 247 which are used for position adjustment, and
immediately to the right a third set of left hand threads 250 which
connect to the interior threads 252 of the connecting collar
portion 224 of the carrier flange 220 so that it can drive the
carrier flange 220 and drive the sprocket section 26.
[0056] The position adjustment section 242 is cylindrically shaped,
and this has a set of internal right hand threads 252 which engage
the central set of right hand threads 247 of the main drive sleeve
section 240. The thread sections 252 and 247 are position
adjustment positioning threads. The right circumferential edge
surface 254 of the position adjustment section 242 functions as an
abutment surface 254 which is positioned to engage a matching
abutment surface 256 of the connecting member or collar 224 of the
carrier flange 220. The positioning adjustment section 242 has at
its left end a cylindrical extension portion 258 having a thickness
dimension slightly less than its main body portion having the
interior threads 252. This extension portion 258 engages a seal
which is shown in FIG. 4 and indicated by numeral 260.
[0057] Also, there is at the right abutment edge surface 254 of the
positioning section 242 a pair of notches 262 (see FIG. 6A) which
can be engaged by a matching wrench which would have two
diametrically opposed fingers that fit into these notches 262.
Thus, during assembly the wrench could be inserted and rotated one
way or the other to thread the positioning adjustment section 242
to the desired position.
[0058] With the components of the power-assist shaft section 190
having now been described, let us now turn our attention to the
manner in which it may be assembled in the crank housing 25.
[0059] We shall assume that the original crank shaft and the pedal
section 24 have been removed from the crank housing 25 so that
there is nothing in the crank housing 25 or extending therefrom.
The first step is to engage the adapter 204 with its bearing 209
and the seal 30 by inserting the bearing 209 in the operating
position in the adaptor and also place the seal 260 in its
operating position at the end of the adapter 204. Then the adapter
204 is inserted into the left side of the crank housing 25 and
threaded into the crank housing 25 to its operating position, as
shown in FIG. 4.
[0060] The next step is to substantially repeat this same step with
the right connecting adapter 212 and its bearing 219, namely to
mount the bearing 219 into its operating position in the connecting
adapter 212, then to insert it into the right side of the crank
housing 25, and thread the adapter 212 into its operating position
as shown in FIG. 4.
[0061] Then the tubular main drive sleeve 240 is inserted into the
crank housing 25 from the left side thereof, and pushed inwardly
until it buts against the inner race of the bearing 209.
[0062] Then the adjustment sleeve 242 is inserted into the right
end of the adapter 212 and rotated so that it begins to come into
threaded engagement with the threads 247 at the rear end of the
drive shaft 240. Then a two pronged wrench is then used to continue
the rotation of the sleeve 242 as discussed previously until the
adjustment sleeve 242 bottoms out. As the adjustment 242 is moving
to its "bottom out" position, the extension portion 258 of the
adjustment sleeve moves into its position within the seal 260. One
of the reasons for rotating the adjustment sleeve 260 until it does
bottom out is to make sure that the extension portion 258 has come
into proper engagement with the seal 260.
[0063] The next step is to adjust the position of the adjustment
sleeve 242. However, before getting into the details it may be
helpful to pause in this step-by-step presentation and provide some
comments on these components that are involved. It will be noted
that the internally threaded portion 252 of the position adjustment
section 242 has a slightly greater diameter than the external
threads 250 of the drive sleeve section 240. Thus, the interior
threads 252 of the position adjustment section 242 are able to
engage the central position threads 246 of the drive sleeve section
240.
[0064] The threads 247 are right hand threads, and these engage the
matching right hand threads 252 of the positioning member 242. The
rear positioned threads 250 of the main drive sleeve section 240
are left hand threads which match the left hand threads 244 of the
collar portion 224 of carrier flange 220.
[0065] To turn our attention back to the adjustment sleeve 242, if
adjustment is needed, then the carrier section 222 is removed, and
the tool is used to rotate the position adjustment member 242 to a
more desired position. This can be done by pre-measure or in a "hit
and miss" fashion until a happy medium is found. With regard to the
"pre-measure" method, if the pitch of the threads is already known,
then the distance by which the right and left pedal sections are
properly spaced can be measured. When these dimensions are known,
then the proper number of rotations of the position adjustment
section 242 could be made so that the adjustment sleeve 242 is
moved precisely to provide the proper length dimension.
[0066] With regard to the advantages of this design, in earlier
designs it would be necessary to have shims of different dimensions
being positioned between abutting surfaces. It would usually be
desired to have the tolerance be as close as five thousandths of an
inch, and this would make it necessary to have a variety of shims
at different widths to get precise dimensioning.
[0067] With the adjustment sleeve 242 properly in place, the rest
of the components can be assembled in the arrangement as shown in
the accompanying drawings.
[0068] In this embodiment these shims are not needed. Also, an
advantage of this embodiment of the invention is that since it can
precisely position the components, there would be very little
shifting laterally from the axis of rotation. If there is a lack of
clearance or too much, or there is some slight lateral shifting,
this subjects the components to interference lateral loads so that
it would preload the bearing surfaces. This would cause the
bearings to deteriorate rapidly.
[0069] With the regard to the materials of the components of this
embodiment, the following members are made from steel, namely
gears, seal sleeves, high load small diameter shafts, and
counterweights. The following members are made of aluminum, namely,
housings, moderately loaded shafts, carrier flange and drive tube
shafts. The reason for certain components being made of steel
occurs when high loads require maximum strength. Aluminum is used
to reduce weight, cut costs and to provide long tool life. For
example, one reason that the member 242 is made of steel is that
the forward extension 258 can properly provide a hard and polished
surface with the seal member 260.
[0070] To describe the overall operation of the present invention,
let us assume first that the rider is on the bicycle and pedaling
the bicycle under human power, without any power-assist. As the
cyclist pushes on the pedals to cause rotation of the crankshaft
170, the clutch member 180 in this mode has its first and second
clutch portions in driving engagement so that the clutch 180 drives
the forward sprocket section 26 to deliver power to the rear wheel
16.
[0071] At the same time, the power-assist shaft section 190, being
fixedly connected to the forward sprocket section 26, also rotates
at the same speed as the crankshaft 170. However, with the
power-assist apparatus 60 not operating, the first clutch portion
of the freewheeling clutch 188 is not rotating, but the
freewheeling portion of the clutch member is free to rotate with
the power-assist shaft 190.
[0072] Now let us assume that the bicycle 10 is starting to go up
the hill, and the rider wants to have the power-assist operating in
addition to his pushing on the pedals. The motor 62 would be
started, and the control lever for the throttle of the motor 62
would be positioned at a convenient location, such as at the
handlebar. As the speed of the motor 62 increases, an automatic
engine clutch engages, and the speed of rotation of the output
sprocket 164 also increases. At such time as the rotational speed
of the outer sprocket member 194 matches rotational speed of the
power-assist shaft 190, the two portions of the clutch members 180
and 188 will be in driving engagement, so that power is delivered
from the motor 62 to the power-assist shaft 190 and into the
forward drive sprocket 28. The clutch members 180 and 188 are one
way clutches. Thus, the rider would still be pedaling and would
still be exerting a drive force through the pedal assembly, while
the power-assist apparatus 60 would be providing additional power
to maintain the desired bicycle speed up the hill. However, if the
rider stops pedaling, the power-assist cannot forcibly drive the
pedal crank arms, and the clutch 180 would be freewheeling, thus
providing a substantial safety factor.
[0073] Now let us assume that the bicycle rider has reached the top
of the hill and is traveling over a level pathway or road. If the
rider is feeling some fatigue and wishes to take a "breather", the
rider can simply stop pedaling. In this instance, the motor section
62 would still be operating, and power would still be delivered to
the power-assist shaft 190. The clutch 188 would be operating in
its drive mode, while the clutch 180 would be operating in its
freewheeling mode. Thus, the power-assist cannot forcibly drive the
pedal crank arms, thus (as indicated above) providing a substantial
safety factor.
[0074] Now, let us assume the bicycle is coasting downhill without
any power-assist and with the pedals 176 stationary. In this
operating mode, both of the clutches 180 and 188 are freewheeling.
Also for added safety there is usually a free wheeling clutch at
the rear wheel hub.
[0075] Also, it should be recognized that another advantageous
feature is that with the motor 68 being operated at a very high
RPM, the torque of the output of the motor 68 is relatively very
small compared to the torque at the output of the speed-reducing
gear section, this reducing stress on the bicycle frame.
[0076] FIG. 7 is an isometric drawing showing a modified
construction of some of the components of the speed reducing gear
section 64. For ease of explanation, there will be no attempt to
match the numerical designations in FIG. 7 with the various
numerical designations that appear earlier in this text. Rather,
these will simply be described with numerical designations not
previously appearing in this text.
[0077] There are in all four components which are shown in FIG. 7,
namely, a center shaft 270, an eccentric sleeve 272, a
counterweight 274, and an input adapter 276. For ease of
illustration the input adapter 276 is shown only schematically, and
in an actual apparatus, this member 276 would be structured to be
compatible with the components shown in FIG. 3 that are to the
right of the counterweight shown in FIG. 3 at 118.
[0078] The shaft 270 is centered on the main axis of rotation, and
it comprises a head 278 and a shank 280 having a threaded end
portion 282. The eccentric sleeve 272 has an offset cylindrical
through opening 284 which is centered on the axis of the shaft 270.
The eccentric sleeve has a longitudinally extending connecting
member 286.
[0079] The counterweight 274 has a center opening 288 and a
connecting slot 290 that is aligned with a connecting member 286 of
the eccentric sleeve 272. Finally, the input adaptor 276 has an
outer cylindrical member 292 which is adapted to make a connection
to another component, and this has a centrally extending
cylindrical inner member 294 which fits through the opening 288 of
the counterweight 274. Further, this center member 294 is arranged
so it extends all the way through the opening 288, so that its end
portion abuts against a surface 298 of the eccentric sleeve 272.
The member 294 also has recess 299. In the connected position the
connecting member 286 extends through the connecting slot 290 and
inwardly engages the recess 299. This is designed to correctly time
and drive the counter weight and the eccentric drive.
[0080] A second embodiment of the present invention will now be
described with reference to FIGS. 8 and 9.
[0081] In FIG. 8, there is shown a lower part of a bicycle 310
having a bicycle frame 312 which is, or may be, similar to the
bicycle frame of the first embodiment. There are front and rear
frame members 314 and 315, respectively. The bottom part of the two
frame members 314 and 315 meet at a connecting location 317 at
which the lower end portions of these frame members 314 and 315
connect directly to one another or connect to a component which is
at this connecting location. There is also a pedal-section 316
having a center axis of rotation which in this embodiment is
adjacent to the lower connecting portions of the two frame members
314 and 315. The bicycle has front and rear wheels 318 and 319.
[0082] The power-assist apparatus 320 of this second embodiment
comprises a motor section 322 (see FIG. 8), a speed-reducing
section 324, and a power-assist section 326 (see FIG. 9 for
sections 324 and 326). The motor section 322 is located adjacent to
(and located rearwardly from) the rear part of the front wheel, and
forwardly of the front frame member 314. The speed-reducing section
324 is closer to the axis of rotation of the peddle section 316,
and the power assist section 326 is located so that its main center
axis of rotation is coincident with the center axis of rotation of
the peddle-section 316.
[0083] Reference is now made to FIG. 9 to describe the
speed-reducing section 324. There is a power input connection 334
in which is located a centrifugal-clutch 336. An output portion of
the clutch 336 connects to a threaded connecting input-shaft 338
that comprises a pinion-gear 340. The pinion-gear 340 connects to a
bevel-gear 342 which in turn drives the main output-shaft 344
through a spline-connection.
[0084] The output-shaft 344 has an eccentric-shaft portion 346. In
the first embodiment, the eccentric-shaft portion was made as a
separate member. In this embodiment, the eccentric-shaft portion
346 is formed integrally with the output-shaft 344. There is also a
counter-weight 348 and (as in the first embodiment) this is
mechanically attached to the output shaft. Located at a more
forward portion of the power-input shaft 44 there is a cluster-gear
section 350 with components of an eccentric-drive section similar
to those components indicated at 136 and 128 in the first
embodiment. However, the cluster-gear section 150 differs from that
which is in the first embodiment in that the gear portion of a
smaller diameter and the one with a larger diameter have their
respective positions reversed in this second embodiment.
[0085] There is an output-drive member 352 which is driven from the
shaft driving the cluster-gear section. The member 352 has an
overall circular configuration and rotates about the axis of
rotation of the output-shaft 344. This output-drive member 352 has
its circumference formed with gear teeth to form an exterior
spur-gear 354 which has a drive-connection to an overrunning clutch
356 which serves the same function as the overrunning clutch 188 of
the first embodiment.
[0086] The power-assist section 326 of this second embodiment is
(or may be) exactly the same as the power-assist output-section 66
of the first embodiment. Therefore, there will be no detailed
description of the configuration and operation of this power-assist
section 326.
[0087] In this second embodiment, the power-assist output-section
has its axis of rotation coincident with the main-center axis of
the pedal-section 316, and the speed-reducing section 324 extends
in a forward direction toward the front-wheel when installed in the
bicycle. FIG. 9 is a cross-sectional configuration with the plane
of the cross-section being aligned horizontally. Thus, in viewing
FIG. 9, the upper part (as seen in FIG. 9) of the speed-reducing
section at the connecting location of the member 338 would be
positioned forwardly of the location of the crank-housing 360.
[0088] To provide a clarification of what is shown in FIG. 9, there
is shown a tubular support member 362 which would be part of the
bicycle frame, and this member 362 connects to the crank housing
360. As shown herein, this tubular member 360 extends horizontally.
However, with the apparatus being installed on the bicycle, this
frame member 362 would extend upwardly from the crank-shaft
360.
[0089] It is evident from comparing FIG. 3 of the first embodiment
with FIG. 9 of the second embodiment that there are substantial
similarities in the structure and operation of these speed-reducing
gear-sections. Accordingly, it is believed that the operation of
the second embodiment can readily be understood from the
information which is given in the first embodiment.
[0090] A third embodiment of the present invention will now be
described with reference to FIG. 9. In FIG. 9, there is shown the
apparatus 410 comprising a motor section 412, a speed-reducing
gear-section 414, and a power-assist section 416.
[0091] This third embodiment is similar to the second embodiment in
that it can be located at a forward lower location of a bicycle
frame in substantially the same manner as shown in the second
embodiment. However, it differs from the second embodiment in that
in this third embodiment invention there is provided an electric
motor 418 which functions as the motor section. This electric motor
comprises a rotor 420, and a stator 422.
[0092] The rotor 420 attaches to a drive-shaft 424. As in the
second embodiment, the drive-shaft 424 has a counter-weight 426.
There is also a cluster-gear 428 that is positioned around the
drive-shaft 424 and rotates around an eccentric-drive portion of
the shaft 424. There is a ring-gear 430 which comes into engagement
with the cluster-gear 428.
[0093] The cluster-gear assembly ultimately drives an output-drive
member 432 which corresponds to the output-drive member 352 of the
second embodiment. As in the second embodiment this output-drive
member 432 is in the form of a spur-gear and has a set of
gear-teeth 434 located on its circumference.
[0094] In this third embodiment, the power-assist section 416 is
(or may be) the same as (or similar to) the power-assist section
326 of the second embodiment.
[0095] The aforementioned overrunning clutch 436 has its
overrunning clutch-portion engaging the gear-teeth 434 of the
output-drive member 432. The power-assist section 416 is positioned
inside of the crank housing 438 and is aligned with the center axis
of the crank housing 438.
[0096] It is evident in comparing the drawings and text relating to
the second embodiment to the drawings and text of this third
embodiment the third embodiment is (except for having the electric
motor), that the third embodiment is quite similar (or nearly the
same as) the second embodiment. Accordingly, it is believed that
the operation of this third embodiment can be readily understood
from the information which is given in the descriptive text and
drawings of the second embodiment, and also to some extent to the
first embodiment.
[0097] It is obvious that various modifications could be made to
the presently shown embodiments without departing from the basic
invented features thereof.
[0098] While the present invention is illustrated by description of
several embodiments and while the illustrative embodiments are
described in detail, it is not the intention of the applicants to
restrict or in any way limit the scope of the appended claims to
such detail. Additional advantages and modifications within the
scope of the appended claims will readily appear to those sufficed
in the art. The invention in its broader aspects is therefore not
limited to the specific details, representative apparatus and
methods, and illustrative examples shown and described.
Accordingly, departures may be made from such details without
departing from the spirit or scope of applicants' general
concept.
* * * * *