U.S. patent application number 13/340568 was filed with the patent office on 2013-07-04 for terrain resilient wheel maintaining a uniform elevation.
The applicant listed for this patent is Patrick Timothy Donohue. Invention is credited to Patrick Timothy Donohue.
Application Number | 20130167991 13/340568 |
Document ID | / |
Family ID | 48693891 |
Filed Date | 2013-07-04 |
United States Patent
Application |
20130167991 |
Kind Code |
A1 |
Donohue; Patrick Timothy |
July 4, 2013 |
Terrain Resilient Wheel Maintaining a Uniform Elevation
Abstract
A wheel includes a central hub and a flexible rim. A drive band
configuration including a plurality of flexible bands extends as
spokes from the central hub to the rim. The hub and band
configuration cause the rim to flex toward and away from the hub as
the wheel moves.
Inventors: |
Donohue; Patrick Timothy;
(Portland, OR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Donohue; Patrick Timothy |
Portland |
OR |
US |
|
|
Family ID: |
48693891 |
Appl. No.: |
13/340568 |
Filed: |
December 29, 2011 |
Current U.S.
Class: |
152/5 |
Current CPC
Class: |
B60B 1/00 20130101; B60B
2900/351 20130101; B60B 19/04 20130101; B60B 9/04 20130101; B60B
27/0047 20130101; B60B 2900/551 20130101; B60B 9/26 20130101; B60B
2900/90 20130101; B60B 2900/313 20130101; B60B 21/00 20130101 |
Class at
Publication: |
152/5 |
International
Class: |
B60B 9/26 20060101
B60B009/26 |
Claims
1. A wheel, comprising: a central hub; a flexible rim; a drive band
configuration comprising a plurality of flexible bands extending as
spokes from the central hub to the rim; and the hub and band
configuration configured to cause the rim to flex toward and away
from the hub as the wheel moves.
2. The wheel of claim 1, further comprising: the central hub
comprising a plurality of hub components symmetrically arranged
around a central axle; and the band configuration fitted to move
between the hub components and the central axle.
3. The wheel of claim 2, further comprising: the central hub
comprising exactly four hub components.
4. The wheel of claim 2, further comprising: the central hub
comprising exactly six hub components.
5. The wheel of claim 2, further comprising: the central hub
comprising exactly three hub components and three spacers, the
spacers having a smaller radius than the hub components and
configured to maintain a consistent minimum distance from the rim
to the central axle.
6. The wheel of claim 1, further comprising: the drive band
configuration comprising bands joined at their ends into a closed
four-sided periphery.
7. The wheel of claim 1, further comprising: the drive band
configuration comprising bands joined at their ends into a closed
six-sided periphery.
8. The wheel of claim 2, further comprising: each hub component
comprising raised ends configured to rotate against the flexible
rim in a direction opposite a direction of rotation of a central
portion of a corresponding hub component against the band
configuration.
9. The wheel of claim 2, further comprising: each band comprising
teeth to mate with a gear adjoining to the central axle.
10. A wheel hub, comprising: a drive band configuration comprising
a plurality of flexible bands extending as spokes; and a plurality
of hub components configured to cause the drive band configuration
to flex toward and away from the hub as the hub rotates.
11. The hub of claim 10, further comprising: the plurality of hub
components symmetrically arranged around a central axle; and the
band configuration fitted to slide between the hub components and
the central axle.
12. The hub of claim 11, further comprising: exactly four identical
hub components, and exactly four bands forming the drive band
configuration.
13. The hub of claim 11, further comprising: exactly six hub
components, and exactly three bands forming the drive band
configuration.
14. The hub of claim 11, further comprising: exactly six hub
components, and exactly six bands forming the drive band
configuration.
15. The hub of claim 11, further comprising: exactly three smooth
bands and exactly three gear-tracked bands forming the drive band
configuration.
16. The hub of claim 11, further comprising: exactly three hub
components engaging the drive band configuration, and exactly three
spacers, the . spacers configured to maintain a consistent minimum
distance from the rim to the central axle.
17. The hub of claim 10, further comprising: the drive band
configuration comprising bands joined at their ends into a closed
n-sided periphery.
18. The hub of claim 10, further comprising: the drive band
configuration comprising bands joined at their ends into a closed
six-sided periphery.
19. The hub of claim 10, further comprising: the drive band
configuration comprising bands joined at their ends into a closed
four-sided periphery.
20. The hub of claim 10, further comprising: each hub component
comprising ends configured to rotate against the flexible rim in a
direction opposite a direction of rotation of a central portion of
the each hub component against the band configuration.
21. A wheel comprising a hub and spokes, the wheel configured such
that the hub oscillates between the ends of the spokes, with ach
spoke exhibiting a cycle of advancing forward of the hub, receding
inward toward the hub, and advancing rearward from the hub as the
wheel turns.
Description
BACKGROUND
[0001] Wheels and tracks are a primary source of propulsion and/or
motion for a variety of vehicles and applications. Conventional
wheels and tracks tend to churn the terrain they move over. Wheel
designs thus could benefit from a greater capability to adapt to
the terrain while maintaining stability and forward progress.
BRIEF DESCRIPTION OF THE DRAWINGS
[0002] In the drawings, the same reference numbers and acronyms
identify elements or acts with the same or similar functionality
for ease of understanding and convenience. To easily identify the
discussion of any particular element or act, the most significant
digit or digits in a reference number refer to the figure number in
which that element is first introduced.
[0003] FIG. 1 illustrates a tread and rim that form part of a
terrain adaptable wheel.
[0004] FIG. 2 illustrates a configuration of drive bands that may
be coupled to the axis mounts.
[0005] FIG. 3 illustrates construction of a wheel hub.
[0006] FIG. 4 illustrates a drive gear that may be fitted to the
central axis for higher torque applications.
[0007] FIG. 5 illustrates a completed wheel with four hub
components.
[0008] FIG. 6 illustrates a wheel having six hub components and
utilizing six bands.
[0009] FIG. 7 illustrates a gear driven six spoke hub design.
[0010] FIG. 8 illustrates a hybrid design employing bands with gear
tracks and bands without gear tracks.
DETAILED DESCRIPTION
Preliminaries
[0011] References to "one embodiment" or "an embodiment" do not
necessarily refer to the same embodiment, although they may. Unless
the context clearly requires otherwise, throughout the description
and the claims, the words "comprise," "comprising," and the like
are to be construed in an inclusive sense as opposed to an
exclusive or exhaustive sense; that is to say, in the sense of
"including, but not limited to." Words using the singular or plural
number also include the plural or singular number respectively,
unless expressly limited to a single one or multiple ones.
Additionally, the words "herein," "above," "below" and words of
similar import, when used in this application, refer to this
application as a whole and not to any particular portions of this
application. When the claims use the word "or" in reference to a
list of two or more items, that word covers all of the following
interpretations of the word: any of the items in the list, all of
the items in the list and any combination of the items in the list,
unless expressly limited to one or the other.
Overview
[0012] Embodiments of a wheel are described, having a load-bearing
(central) axis that shifts horizontally in a uniform horizontal
plane as it moves across the terrain. The wheel includes a central
hub and a flexible rim. A drive band configuration for the wheel
includes flexible bands extending as spokes from the central hub to
the rim. The hub and band configuration are configured to cause the
rim to flex toward and away from the hub as the wheel moves. The
wheel thus tends to unfold over the terrain, rather than churn the
terrain as would a conventional wheel.
Detailed Descriptions of Particular Embodiments
[0013] FIG. 1 illustrates a tread 104 and rim 106 that form part of
a terrain adaptable wheel. Axle mounts 102 may be attached to the
rim 106, for example using mounting holes 108 (e.g., via machine
screws through the mounting holes). The tread 104 is illustrated as
a caterpillar type, but may in fact be any tread suitable to the
vehicle and the terrain. The rim 106 may be metal, plastic, or
other suitable materials. Likewise, the tread 104 may be rubber,
metal, plastic, or any suitable material. Multiple axle mounts 102
may be fixed to the rim 106 at multiple locations. The ends of the
rim 106 are illustrated with a slight gap between them, but would
typically be joined together. In some designs the rim 106 may be
constructed using two strips of clock spring, fused to a single
strip of rubber tire.
[0014] Typically, the axle mounts 102 will be spaced at equal
intervals around the circumference of the rim 106. Embodiments
including four and six axle mounts 102 will be described, although
other numbers of axis mounts are also possible depending upon
requirements of the particular implementation.
[0015] FIG. 2 illustrates a configuration of drive bands 210 that
may be coupled to the axle mounts 102. The drive band configuration
210 is comprised of multiple drive bands 204. Each drive band 204
may be formed to flex along a long axis of the band 204 and may be
substantially rigid to both sheer and twisting force along axes
perpendicular to the long axis. Example materials for the band 204
are carbon steel, stainless steel, other metals and alloys, and
plastic. The bands 204 are joined together at each end using
couplers 202. Each coupler 202 couples a joint of the band
configuration 210 to a axis mount 102 via an inserted axle 208. The
axle 208 is inserted through the coupler 202 and through the axle
mounts 102 on either end of the axle 208. A flexible cover 206
(e.g., a cylindrical polyethylene cover) may be fitted over each
coupler 202 to reduce friction of the coupler 202 against the axle
mounts 102 (give example materials for cover 206). Before inserting
the axle 208, the coupler 202 is rotated so that once the axle 208
is inserted, a gap 212 in the coupler 202 is rotated 180 degrees
from a gap 214 in the axle 208. This secures the joint between
drive bands 204 and also allows for some limited motion of the
joint within the coupler 202 once it is coupled to the axis mount
202 during rotation of the wheel.
[0016] One design includes a drive band configuration constructed
from four bands joined at their ends into a closed four-sided
periphery. Another design includes a drive band configuration
constructed from six bands joined at their ends into a closed
six-sided periphery. Designs including n numbers of bands formed
into closed n-sided peripheries (eight, ten, etc.) are also
possible.
[0017] FIG. 3 illustrates construction of a wheel hub 310. The
wheel hub 310 is constructed from a plurality of hub components
302. Hub components 302 are symmetrically positioned around a
center axle 308. Each hub component 302 may comprise ends 304
having a diameter (circumference) that is larger in relation to an
inner circumference of the hub component 302. In some designs
(e.g., four spoke designs), the ends 304 are separate elements
rotationally coupled the hub component 302. In these designs, as
the rim 106 moves inward toward the hub 310, it contacts the ends
304 of the hub components 302, and the ends 304 rotate against the
rim 106 as the wheel turns. The ends 304 rotate against the rim 106
in an opposite direction of rotation of the inner diameter 314
against the bands 204. This provides stability to the flexible rim
106 without decreasing terrain flexibility. Thus each hub component
302, as a unit including its ends 304, simultaneously rotates both
clockwise and counterclockwise as the wheel turns.
[0018] The band configuration 210 is compressed inwardly near the
center of each band 204 and compressed to fit between the center
axle 308 and each of the hub components 302. The result is that
each spoke from the hub 310 to the rim 106 comprises two bands 204
pressed together. Couplers 306 are fitted over both ends of the hub
310 and retain the band configuration 210 within the hub 310 and
retain the hub components 302 in a symmetrical configuration. Power
from a drive axle (e.g. axle 308) may be transferred to the hub 310
via the couplers 306 in some designs.
[0019] In some implementations, particularly those that use a
coordination gear on the center axle 308, some hub components have
a first inner circumference 314, and others have a second, smaller
circumference (refer to FIGS. 7 and 8). The smaller circumference
components are used as spacers to limit the rim 106 minimal
distance from the center axle 308 as the wheel turns and to hold
the bands 402 snug with component 714 and gear 406.
[0020] FIG. 4 illustrates a coordination gear 406 that may be
fitted to the central axle 308. The gear 406 coordinates motion of
the bands 402. Each band 402 of the band configuration 210 may
comprise a gear track 404 to mate with teeth of the coordination
gear 406. In models employing a coordination gear 406, each spoke
from the hub 310 to the rim 106 may comprise only a single band
402. The gear 406 rotates freely upon the outside of the central
axle 308 of the wheel, coordination motion of the bands 402.
[0021] FIG. 5 illustrates a completed wheel with four hub
components 302. The bands 204 are compressed between the central
axle 308 and the hub components 302. Each band is coupled to the
rim 106 by axle mounts 102. As the wheel turns, the ends of the
bands 204 pivot around the axis 208 which couples the bands 204 to
the axle mounts 102. The bands 204 are extended away from the hub
310 or are drawn toward the hub 310, depending on the position of
the wheel, giving the rim 106 and tread 104 a peripheral shape that
varies according to the position of the wheel and the topography
under the wheel. The rim 106 and tread 104 yield and flex according
to the terrain, thus shifting mass of the wheel and any associated
vehicle more directly over a force normal to the surface being
traversed. In this manner, the wheel adapts efficiently to the
terrain it is traversing.
[0022] A wheel employing a hub design in accordance with these
features and principles swivels between a plurality (e.g., two)
pivot points of the rim 106 as it rotates. The hub oscillates
between the ends of the flexible spokes. Each spoke exhibits a
cycle of advancing forward of the hub, receding inward toward the
hub, and advancing rearward from the hub. The spokes act in unison
to deflect the rim in a manner that contributes to gripping the
terrain.
[0023] In the case of a four-spoke wheel, the bottom spoke,
orthogonal to the ground, recedes inward towards the hub. This
causes the top spoke to also recede inward. The other two spokes
(horizontally positioned) advance outward providing indirect
load-support for the hub.
[0024] The four-spoke wheel design employs hub components 302
comprising an inner diameter (circumference 314) and a larger,
outer diameter 304 that rotates independently of the inner diameter
314. The outer diameter 304 of the components 302 may rotate
against the rim 106 as the wheel turns, in an opposite direction of
rotation as the rotation of the inner diameter 314. The components
302 may be constructed from an inner rotating member with washers
rotationally coupled to the ends.
[0025] The particulars of the motion and shape of the rim may vary
between designs that employ the features and principles described
herein, depending upon design details of the implementation and
components.
[0026] FIG. 6 illustrates a wheel having six hub components 302 and
utilizing six bands 204. As the wheel turns, the relative distance
of the rim 106 from the central axle 308 varies according to the
topography of the surface. The wheel's mass is efficiently shifted
more directly over the force normal to the surface being
traversed.
[0027] The central bottom spoke recedes inward which causes the two
adjacent spokes to advance outward at an acute angle to the
terrain. This deflection results in the hub being supported by
three spokes and not just a single spoke, as is the case of a
four-spoke wheel.
[0028] The particulars of the motion and shape of the rim may vary
between designs that employ the features and principles described
herein, depending upon design details of the implementation and
components.
[0029] Designs comprising six, eight, and higher numbers of spokes
need not comprise hub components 302 with a larger,
independently-rotating outer diameter (as do certain four spoke
designs, e.g. FIG. 5). Two spokes adjacent to the bottom, central,
orthogonal spoke advance outward at an acute angle to the terrain
during rotation, maintaining the hub is in a state of equilibrium,
balanced by opposing forces of the three supporting spokes. In
these designs, the hub components 302 do not ride upon (rotate
against) the rim 106 of the wheel.
[0030] FIG. 7 illustrates a gear coordinated six spoke hub design.
The hub comprises bands 402 comprising gear tracks, as illustrated,
for example in FIG. 4. A gear 406 coordinates motion of the bands
402. Each end of a band 402 forms a spoke of the hub. Thus, three
bands are sufficient to construct a six-spoke hub in the gear
coordinated design. Bands 402 ride upon an outer circumference 714
of hub components 702. The outer circumference 714 of hub
components 702 allows the gear tracked band to tightly arc
component 702. Couplers 710 prevents lateral motion of the bands
402.
[0031] Spacer hub components 708 are provided to fit in a space
between the larger diameter hub components 702 when the hub is
assembled. Spacers 708 fill in these gaps and retain the bands 402
in the hub and against the gear 406. Couplers 710 may be employed
to secure and properly orient the hub components in relation to one
another, serving a similar purpose of a component 306 in FIG. 3.
Couplers 710 may also transfer power from a drive axle (e.g., 308)
to the hub.
[0032] The spacers 708 do not necessarily have a smaller diameter
than the inner circumference 712 or outer circumference 714 of the
hub components 702. Rather, the spacers 708 has a diameter selected
to fit snugly between the bands 402 and the gear 406. For example,
the circumference of the spacers 708 may be equal to the inner
circumference 712 of the hub components 702 in some designs, or
even larger in circumference depending on the configuration of the
hub components 702.
[0033] FIG. 8 illustrates a hybrid hub design employing bands with
gear tracks and bands without gear tracks. Elements of this hybrid
model which are not essential to the description are omitted from
the drawing for clarity. The hybrid model may achieve benefits of
both the model of FIG. 3. and the gear coordinated model of FIG. 7.
The hybrid model comprises bands 402 with gear tracks, and smooth
bands 204 lacking gear tracks. The bands 402 arc the outer
circumference 714 of the hub components 702. The bands 204 arc the
circumference of the spacer hub components 708. Each spoke of the
hub comprises a portion of a band 402 and a portion of a band 204.
This makes the spokes stronger while still providing for power
transfer to the wheel rim using drive gear 406. Hybrid
implementations comprise two bands per spoke (one gear tracked
band, one smooth band). The gear tracked band 402 engages the gear
406. The smooth bands 204 do not engage the gear 406 but instead
arc the spacer hub components 708. The spacer hub components 708
are sized to prevent the smooth bands 204 from engaging the gear
406. The gear tracked bands 402 coordinate motion of the spokes,
while the smooth bands 204 eliminate chatter and add rigidity to
the spokes. The spokes may attach to the rim mounts 202 where the
ends of bands 402, 204 meet, as described for example in
conjunction with FIGS. 1 & 2.
[0034] The performance of a wheel employing designs in accordance
with the described principles/features may be adjusted by varying
the "true circumference" of the wheel. Extending the circumference
of the wheel by 4-10% beyond the "true circumference" may flatten
the bottom side of the wheel, increasing its grip upon the terrain
and its ability to roll smoother upon flat, hard surfaces. The
"true circumference" is calculated from the diameter measured from
center of the wheel hub to the inside surface of the rim.
[0035] Uses of the rims/wheels in accordance with the described
principles/features include, by way of example, tracked vehicles,
steep climbing vehicles, rough or multi-terrain vehicles (e.g.,
military, amphibious, police, scientific), and robotic
vehicles.
Comparison of Gear Driven and Non Gear-Driven Designs
[0036] Table 1 provides a comparison of implementations including
only gear track bands (A), only smooth bands (B), and both gear
track and smooth bands (C). Each hub design comprises six spokes.
Of course, other hub designs along the same principles may include
a different number of spokes.
TABLE-US-00001 TABLE 1 Comparison of hub designs A B C Number of
bands 3 6 6 Number of gear- 3 0 3 tracked bands Number of spokes 6
6 6 Bands per spoke 1 2 2 Number of hub 3 (3 additional hub 6 6
components engaging components act as spoke bands spacers only)
Number of spacer hub 3 (3 hub components 0 (no spacer hub 3 (3 hub
components components act as spacers only, components are used) act
as spacers but also and do not engage engage spoke bands) spoke
bands) Hub component type (1) Larger outer Uniform diameter (1)
Larger outer diameter with recessed diameter with recessed inner
diameter inner diameter (2) Spacers with (2) Spacers with uniform
diameter uniform diameter smaller than outer smaller than outer
diameter of (1) diameter of (1)
Implementations and Alternatives
[0037] For a predetermined overall hub size, a number of spokes
(e.g., 4, 6, 8 . . . ) may be chosen. Based on the hub size and
number of spokes, a size of the hub components is determined to
pressure fit against the compressed band configuration while
encircling the center axle.
[0038] As previously noted, in implementations that utilize a
coordination gear and bands with gear tracks, a different sizing
may be utilized for the hub components. For example, for a six
spoke design, three hub components may have a first diameter, and
three hub components may utilize a smaller or different diameter.
Spacer components of a different diameter may act to keep the gear
engaged against the gear tracks on the bands and/or to maintain
contact between the bands and the various hub components, while
maintaining a consistent minimum distance between the rim 106 and
the central axle (i.e., acting as spacers).
[0039] The hub components may be formed from a single piece of
molded or milled material, or assembled from multiple components
(e.g., one component for the band roller, others for the ends that
roll against the wheel rim). The couplers and central axle may be a
single piece, or assembled from multiple components. The hub
perimeter may have a non-circular cross section (e.g., square,
hexagonal, octagonal, etc). The hub components may be implemented
as ball or roller bearings, with or without an extended inner
ring.
[0040] Particular embodiments of a wheel utilizing certain
mechanical features/principles have been described. Variations of
the described embodiments utilizing these or similar features and
principles will now be apparent to those having skill in the art in
light of this disclosure. The range of wheel designs that the
inventor has conceived is not limited to the disclosed embodiments,
but to all designs that utilize the features and principles herein
disclosed, and as set forth in the claims.
* * * * *