U.S. patent application number 11/589839 was filed with the patent office on 2007-02-22 for pillar stem for aerobar assembly.
Invention is credited to Horizon Garrison Peter Meng.
Application Number | 20070039409 11/589839 |
Document ID | / |
Family ID | 35446234 |
Filed Date | 2007-02-22 |
United States Patent
Application |
20070039409 |
Kind Code |
A1 |
Meng; Horizon Garrison
Peter |
February 22, 2007 |
Pillar stem for aerobar assembly
Abstract
An aerobar assembly is arranged to be mounted on a pillar stem,
rather than on the handlebars, of a bicycle. The pillar stem in
turn supports the handlebars. By mounting the aerobar on the stem,
the range of adjustability of the aerobar is greatly increased, and
the handlebar is subject to less torsional forces. The aerobar
assembly includes a pillar stem having one end secured to the stem
and a support structure at a second end for mounting an aerobar
bracket, an arm rest support, and handlebar clamps. The aerobar
bracket is arranged to permit axial adjustment of aerobar position,
while the arm rest support is arranged to enable lateral,
horizontal pivoting, vertical swivelling, and fore-aft adjustment
of arm rest position independent of aerobar position. The handlebar
mount preferably uses C-clamps that can easily be substituted to
accommodate different handlebar configurations.
Inventors: |
Meng; Horizon Garrison Peter;
(San Francisco, CA) |
Correspondence
Address: |
BACON & THOMAS, PLLC
625 SLATERS LANE
FOURTH FLOOR
ALEXANDRIA
VA
22314
US
|
Family ID: |
35446234 |
Appl. No.: |
11/589839 |
Filed: |
October 31, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10893361 |
Jul 19, 2004 |
7127966 |
|
|
11589839 |
Oct 31, 2006 |
|
|
|
Current U.S.
Class: |
74/551.8 |
Current CPC
Class: |
B62K 21/125 20130101;
Y10T 74/20822 20150115; Y10T 74/2078 20150115; B62K 21/12
20130101 |
Class at
Publication: |
074/551.8 |
International
Class: |
B62K 21/12 20060101
B62K021/12 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 8, 2004 |
TW |
93-209002 |
Claims
1. A pillar stem structure suitable for removably and adjustably
mounting handlebars and aerobars to a bicycle fork or steering
column, comprising: at a first end, a stem-securing structure for
securing the pillar stem to a generally vertical fork of a bicycle
and, at a second end, an integral support structure; first threaded
openings in the support structure for receiving first fasteners
arranged to secure a first sub-assembly to the support structure;
second threaded openings in the support structure for receiving
second fasteners arranged to secure a second sub-assembly to the
support structure; and third threaded openings in the support
structure for receiving third fasteners arranged to secure
handlebar clamps to the support structure.
2. A pillar stem structure as claimed in claim 1, further
comprising knee bumpers arranged to fit over and to be secured to
said stem securing structure.
3. A pillar stem structure as claimed in claim 2, wherein said knee
bumpers include projections arranged to extend into openings in
fasteners for the stem securing structure.
4. A pillar stem structure as claimed in claim 2, wherein said knee
bumpers are made of a thermal plastic elastomer.
5. A pillar stem structure as claimed in claim 4, wherein said
bumpers are arranged to snap onto the stem securing structure.
6. A pillar stem structure as claimed in claim 1, wherein at least
one of said first fasteners, second fasteners, and said third
fasteners are titanium bolts treated with a physical vapor
deposition (PVD) coating.
7. A pillar stem structure as claimed in claim 6, wherein said PVD
coating is a color spectrum coated finish.
8. A pillar stem structure as claimed in claim 1, wherein said
second threaded openings are situated in a top surface of said
pillar stem structure, and further comprising a moisture outlet in
communication with a respective said first threaded opening for
draining moisture from said first threaded opening.
9. A pillar stem structure as claimed in claim 1, wherein said
first threaded openings are situated in a bottom of said pillar
stem structure, and further comprising a gasket arranged to seal
said second threaded openings when not being used to secure the
second sub-assembly.
10. A pillar stem structure as claimed in claim 9, wherein said
gasket include projections arranged to fit into and secure said
gasket to said second threaded openings.
11. A pillar stem structure as claimed in claim 9, wherein said
gasket is made from a thermal plastic elastomer.
12. A pillar stem structure as claimed in claim 1, further
comprising at least one eccentric collar member arranged to fit
over the fork or steering column and to provide a variably angled
surface to which the stem securing structure is clamped in order to
vary an angle of the pillar stem relative to the fork or steering
column.
13. A pillar stem structure as claimed in claim 12, wherein said
collar includes a rim and a cylindrical body extending at a
predetermined angle relative to the rim, whereby rotation of the
collar relative to a vertical axis changes an orientation of the
cylindrical body relative to the vertical axis.
14. A pillar stem structure as claimed in claim 12, wherein said
collar includes a gap that enables it to be fitted over the fork or
steering column and that serves as a marker for orienting the
collar.
15. A pillar stem structure as claimed in claim 12, wherein said
collar includes an upper member and a lower member.
16. A pillar stem structure as claimed in claim 12, wherein said
collar is a one-piece collar.
17. A pillar stem structure as claimed in claim 12, wherein said
first sub-assembly is an aerobar bracket sub-assembly including a
bracket, aerobars and aerobars adjustably secured in the
bracket.
18. A pillar stem structure as claimed in claim 1, wherein said
second sub-assembly is an arm rest sub-assembly including an arm
rest support removably secured to the support structure of the
pillar stem, arm rest plates, and arm rest plate fasteners for
adjustably securing the arm rest plates to the support.
19. An eccentric collar member arranged to fit over a fork or
steering column and to provide a variably angled surface to which a
stem securing structure is clamped in order to vary an angle of a
pillar stem relative to the fork or steering column.
20. A pillar stem structure as claimed in claim 19, wherein said
collar includes a rim and a cylindrical body extending at a
predetermined angle relative to the rim, whereby rotation of the
collar relative to a vertical axis changes an orientation of the
cylindrical body relative to the vertical axis.
21. A pillar stem structure as claimed in claim 19, wherein said
collar includes a gap that enables it to be fitted over the fork or
steering column and that serves as a marker for orienting the
collar.
22. A pillar stem structure as claimed in claim 19, wherein said
collar includes an upper member and a lower member.
23. A pillar stem structure as claimed in claim 19, wherein said
collar is a one-piece collar.
Description
[0001] This application is a continuation-in-part of U.S. patent
application Ser. No. 10/893,361, filed Jul. 19, 2004.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates to an aerodynamic handlebar extension
for bicycles, also known as an "aero bar" or aerobar, and in
particular to an aerobar assembly that mounts on the handlebar stem
that is part of the frame of the bicycle, rather than on the
existing handlebars, and that thereby provides improved
adjustability, comfort, and safety.
[0004] 2. Description of Related Art
[0005] The concept of handlebar extensions that permit the rider of
a bicycle to assume an improved aerodynamic position, by
positioning the rider's hands forwardly of the handlebar and by
providing support for the riders elbows or forearms, is well-known.
Conceived in the mid-1980's, the aerobar was quickly adopted by
triathletes. Since Greg LeMond used them in winning the 1989 Tour
de France, aerobars have also attained widespread use by bicycle
racers, particularly during time trials.
[0006] In competitive cycling, proper fitting or adjustment of the
aerobar to the rider is critical to achieving optimal performance.
In general, the closer the torso of the rider is to horizontal, the
lower the aerodynamic drag on the rider. However, the resulting
extension of the lower back and hamstrings in the optimal
aerodynamic position may cause injury or discomfort to the rider,
and may prevent the rider from achieving maximum power. In
addition, proper positioning is necessary to ensure clearance for
the rider's knees. As a result, the optimal position for racing or
triathlons depends on the physiology of the rider, and can vary
substantially from rider to rider.
[0007] Most currently available aerobars are either non-adjustable
or have at best a limited adjustability. While the aerobars of an
adjustable aerobar assembly can usually be moved in a fore-to-aft
direction to ensure proper horizontal positioning of the rider and
accommodate different arm lengths, the elbow rests or pads can only
be adjusted laterally, and fail to take into account skew or
angling of the rider's arm, either in a horizontal or vertical
plane. Furthermore, because the conventional aerobars are either
integral with the handlebars or clamped thereto, possibilities for
adjustment are limited by the position and configuration of the
handlebars.
[0008] On the other hand, many conventional aerobar brackets offer
too great a lateral tolerance for the aerobars, because the left
and right aerobar brackets are mounted independently on the
handlebars. This makes it difficult to position the aerobars
symmetrically, in a balanced manner, on the left and right sides of
the stem.
[0009] Another problem with conventional aerobars is the problem of
compatibility. Most conventional aerobars are suitable only for a
single type of handlebars. Different types of handlebars, e.g.,
drop bars or bullhorn style TT bars, require different aerobar
designs to ensure proper positioning and clamping of the aerobar,
provide access to shift levers if stem mounted, and to ensure
clearance between the aerobar mount and the knees of the rider.
[0010] In addition to the problems of limited adjustability and
compatibility, another problem with conventional aerobars is that
they can present a significant safety hazard. The cinch clamps
conventionally used to secure an aerobar to the handlebars of a
bicycle exert a substantial amount of force on the handlebar, in
order to counter the rotational torque exerted when the rider leans
on the aerobars. This anti-torsion clamping force, combined with
vibrations and road shocks, can cause metal fatigue and cracking of
the handlebars, while vibrations and shocks also can cause the
bolts that secure the clamp to the handlebars to loosen and permit
the aerobars so suddenly become loose or fall off.
[0011] Furthermore, because the conventional aerobar handlebar
brackets must be positioned so that the brackets and aerobars clear
the stem, they enable the aerobars to be slid to a position where
they extend behind the fork, in the path of the rider's knees. This
can also present a serious safety hazard.
SUMMARY OF THE INVENTION
[0012] It is accordingly a first objective of the invention to
overcome the drawbacks of the prior art by providing an aerobar
having enhanced performance, comfort, safety, and reliability.
[0013] It is a second objective of the invention to provide an
aerobar that is fully adjustable to enable a rider to assume a
position that provides optimal performance during speed racing, and
that also provides an optimal balance of speed and comfort during
triathlons and other endurance contests.
[0014] It is a third objective of the invention to provide an
aerobar that is simple in construction and easily mounted on a
bicycle.
[0015] It is a fourth objective of the invention to provide an
aerobar that provides increased safety by eliminating the problems
caused by the conventional use of cinch clamps to secure
conventional aerobars to handlebars, including cracking of the
handlebars and loosening bolts.
[0016] It is a fifth objective of the invention to provide an
aerobar that can be adapted to any handlebar style, including those
in which the handlebars have a non-circular cross-section.
[0017] It is a sixth objective of the invention to provide several
improvements to and modifications of the aerobar assembly disclosed
in the parent application Ser. No. 10/893,361.
[0018] These objectives are achieved, in accordance with the
principles of a preferred embodiment of the invention, by providing
an aerobar system that is arranged to be mounted on the handlebar
stem of the bicycle fork, rather than on the handlebars, and that
in turn supports the handlebars.
[0019] According to an especially preferred embodiment of the
invention, the handlebars, aerobars, and arm rests are separately
mounted to a pillar stem clamped to the handlebar stem by cap
screws that thread directly into the pillar stem without the use of
bolts. The bracket/support structures for the aerobars and arms
rests permit a variety of independent adjustments of aerobar and
arm rest position, including fore-to-aft adjustment of aerobar
position, lateral and fore-to-aft adjustment of arm rest position,
and adjustment of arm rest angle or skew in both horizontal and
vertical planes. The handlebar mount preferably uses C-clamps that
can easily be substituted to accommodate different handle bar
configurations.
[0020] By mounting the aerobar on the stem, the range and ease of
adjustability of the aerobars or arm rests may be greatly
increased, while still ensuring that the aerobars will be laterally
centered and positioned away from the riders knees. In addition,
mounting of the aerobars on the handlebar stem of the bicycle fork
rather than the handlebars provide a mechanical advantage that
prevents torsional forces from cracking the handlebars, while the
use of socket or cap screws threaded into a pillar stem to support
the arm rests, aerobars, and handlebars eliminate the problem of
bolt loosening.
[0021] By providing an independent modular support for the
aerobars, it is possible to achieve an optimal stem length for
positioning the handlebars, without or without the addition of
aerobars and arm rests. The pillar stem can initially BE provided
solely as a handlebar support, with the aerobars and arm rests
offered as an option which can easily be installed, removed,
replaced, and/or adjusted at a later time simply by loosening and
tightening one or two screws, without such inconveniences as having
to remove or re-apply handlebar tape.
[0022] Finally, a few further additions and/or modifications of the
above-described aerobar may be made, including: [0023] a. The
addition of knee bumpers to the rear cinch clamp so as to lessen
injuries when a cyclist's knee impacts the clamp. [0024] b. The
addition of arc-variable eccentric collars to provide angular
adjustment of the stem when attached to a bicycle fork or steering
column. [0025] c. The use of titanium bolts or fasteners treated
with physical vapor deposition (PVD). [0026] d. The addition of a
moisture outlet for the stem's upper utility ports. [0027] e. The
addition of a plug gasket for the stem's lower utility ports.
BRIEF DESCRIPTION OF THE DRAWINGS
[0028] FIG. 1A is an isometric view of an aerobar assembly
constructed in accordance with the principles of a preferred
embodiment of the invention.
[0029] FIG. 1B is a side view of the aerobar assembly of FIG.
1.
[0030] FIG. 2 is an exploded isometric view of a pillar stem for
use in the aerobar assembly of FIG. 1.
[0031] FIG. 3A is an exploded isometric view of an aerobar bracket
sub-assembly for use in the aerobar assembly of FIG. 1.
[0032] FIG. 3B is a front view of the aerobar bracket sub-assembly
of FIG. 3A.
[0033] FIG. 3C is a top view of the aerobar bracket sub-assembly of
FIG. 3A, with a modified aerobar configuration.
[0034] FIG. 4 is an isometric view of an arm rest sub-assembly for
use in the aerobar assembly of FIG. 1.
[0035] FIG. 5A is an exploded isometric view of the arm rest
sub-assembly of FIG. 4.
[0036] FIG. 5B is a front view of the arm rest sub-assembly of FIG.
4 after installation of the handlebars.
[0037] FIG. 6 is a cross-sectional front view of the arm rest
sub-assembly of FIG. 4, showing lateral adjustment of the arm
rests.
[0038] FIG. 7 is a side view of the arm rest sub-assembly of FIG.
4, showing pivotal adjustment of an arm rest about the axis of the
arm rest support.
[0039] FIG. 8 is an isometric view of a handlebar that may be used
with the aerobar assembly of FIG. 1.
[0040] FIG. 9A is an exploded isometric view of a modified aerobar
assembly that incorporates several improvements/modifications
including knee bumpers, PVD treated titanium bolts, a moisture
outlet for the stem's upper utility ports, and a plug gasket for
the stem's lower utility ports.
[0041] FIG. 9B is a cross-sectional top view of the cinch clamp
portion of the stem of FIG. 9B, showing a knee bumper.
[0042] FIG. 10A is an isometric view showing two different stem
mounting angles made possible by the use of eccentric collars.
[0043] FIG. 10B is an isometric view of a stem and one set of
collars.
[0044] FIG. 10C is a side view showing the collar of FIG. 10B
rotated to different angles.
[0045] FIGS. 10D and 10E are side views showing the effects of the
various collar angles on the orientation of the stem.
[0046] FIG. 10F shows various stem-angle-adjustment collar
configurations.
[0047] FIG. 10G is an isometric view of an alternative collar
configuration.
[0048] FIG. 10H is an isometric view of yet another alternative
collar configuration.
[0049] FIG. 11A is an isometric view of the assembled stem of FIG.
9A.
[0050] FIG. 11B is an isometric view of the assembled step of FIG.
9A including bicycle fork and handlebars.
[0051] FIG. 12 is an isometric view of the stem of FIG. 9A showing
operation of a moisture outlet for the stem's upper utility
ports.
[0052] FIG. 13 is a cross-sectional side view showing details of a
gasket fitted into the stem's lower utility ports.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0053] FIG. 1A is an isometric view of an aerobar assembly
according to a preferred embodiment of the invention, and FIG. 1B
is a side view. Various sub-assemblies of the aerobar assembly
illustrated in FIGS. 1A and 1B are shown in FIGS. 2-8. FIG. 2
illustrates a pillar stem mount 20 and associated hardware for
mounting the aerobar assembly on the handlebar stem of a bicycle,
and for securing a handlebar 12 to the aerobar assembly, while
FIGS. 3A-3C show a pair of aerobars 32 and a bracket 30 for
adjustably mounting the aerobars on the pillar stem mount, FIGS. 4,
5A, 5B, 6, and 7 illustrate the structure and operation of an arm
rest sub-assembly 40, and FIG. 8 shows one of many handlebar
configurations that may be mounted to the aerobar assembly of FIG.
1.
[0054] As illustrated in FIGS. 1A, 1B, and 2, the pillar stem mount
20 is arranged to be mounted on the handlebar stem of a bicycle
fork (indicated by dashed lines) by means of a cinch clamp 21.
Because the handlebar stem of the bicycle fork typically has a
larger diameter than the handlebars, it is better able to withstand
clamping, and therefore provides a more secure mount for the
aerobar assembly. Furthermore, the pillar stem is subjected by the
handlebars to a linear, downwardly directed force that is absorbed
by the fork rather than to a torsional force borne by the
handlebars, eliminating the problem of metal fatigue and cracking
of the handlebars.
[0055] It will be appreciated that cinch clamp 21 may be replaced
by other types of structures for securing the pillar stem mount to
the fork of a bicycle, or the pillar stem may even be made integral
with the handlebar, without departing from the scope of the
invention. Although not shown, the cinch clamp is typically
tightened by screws or bolts extending through openings in the
clamp in conventional fashion, and the clamp may rest on the fork
into which the pillar stem is inserted.
[0056] The main body of the pillar stem is cylindrical and may be
hollow or solid, although a hollow configuration is preferred in
order to reduce the weight of the assembly. At the opposite end of
pillar stem 20 from the cinch clamp 21 is an integral, generally
c-shaped supporting structure 22 which has three functions: (i) to
support the handlebars; (ii) to support the aerobar bracket; and
(iii) to support the arm rest. The pillar stem including the
supporting structure 22 at one end are preferably cast or machined
as a single piece or member. Each of the handlebars, the aerobar
bracket, and the arm rest assembly is independently mounted on the
c-shaped supporting structure 22, and therefore independently
adjustable.
[0057] The supporting structure is illustrated as including a lower
pair of threaded openings 225 for mounting the aerobar bracket, an
upper pair of threaded openings 224 for mounting the arm rest
sub-assembly, and two pairs of frontwardly facing threaded openings
223 for mounting handlebar C-clamps or brackets 23.
[0058] Preferably, each sub-assembly is mounted using cap screws or
machine screws. The illustrated screws are hex type socket head cap
screws, although other types of screws or fasteners may be utilized
so long as the screws or other fasteners mount the respective
subassemblies to the supporting structure 22 in a secure manner
and, where appropriate, in such a way that the mountings can be
loosened and the positions of the subassemblies adjusted.
[0059] As illustrated in FIGS. 3A-3C, the aerobar bracket 31
preferably includes a pair of openings 311 for receiving aerobars
33 and a central connecting portion in which are located upper and
lower pairs of through-holes 312, either or both pairs of which may
be threaded or smooth.
[0060] Upon insertion of the aerobars to a desired position in the
openings 311, the screws 313, which have been extended through
openings 312 and threaded into openings 225 in the supporting
structure of pillar stem 20 just far enough to avoid stressing the
bracket 31, are tightened to cause the bracket to securely clamp
and center the aerobars in the openings 311 by causing the lower
connecting portion between the openings to be pulled toward the
upper opening. To adjust the forward extent of the aerobars 32,
screws 313 are simply loosed to a point at which the lower
connecting portions is sufficiently far from the upper connecting
portion to enable release of the aerobars for movement within the
openings 32, after which the screws are tightened to the support 22
of pillar stem 21 to again clamp the aerobars.
[0061] Preferably, the bracket positions the aerobars in front of
the fork, so that the fork prevents a user from extending the
aerobars rearwardly to a position where the rider's knees could
come into contact with the aerobars. However, those skilled in the
art will appreciate that the invention is not limited to a
particular aerobar configuration. For example, alternative aerobar
styles are illustrated in FIGS. 3A, 3B, and 3C, the latter having a
dual-curved configuration. The invention is intended to be used
with any aerobar shape, length, and position.
[0062] The arm rest sub-assembly is illustrated in FIGS. 4, 5A, 5B,
6, and 7. Each of the arm plates 42 is adjustably mounted on an
elongated, generally tubular or cylindrical arm plate support 41,
which is mounted on the top of the pillar stem support structure 22
by two screws 413 arranged to extend through openings 412 in the
support 41 and threaded openings 224 at the top of support
structure 22.
[0063] Preferably, support 41 includes some sort of alignment
structure arranged to fit into a complementary alignment structure
in the support structure 22. For example, arm rest support 41 is
illustrated as including notches or depressions 411 arranged to fit
over complementary ridges or projections in the top of the support
structure 22 at the end of the pillar stem 21, thereby facilitating
lateral alignment of the support 41 and the support structure
22.
[0064] Arm rest support 41 includes two hollow sections in which
are fitted two cylindrical, transversely-threaded dual-head nuts
415 arranged to slide axially within the support. Each of the
threaded openings in each of nuts 415 is arranged to receive a cap
screw 41 via slots 414 in support 41 and beveled washers 418. In
addition, the cap screws received by nuts 415 respectively extend
through openings 422 and 423 in the arm rest plates 42, with one of
the pairs of cap screws for each nut extending through opening 422
and the other through opening 423. Openings 422 are circular while
openings 423 are curved slots for reasons that will be discussed
below in connection with FIG. 7.
[0065] The nuts 415 are secured within the support 41 by threaded
end caps 416, which may of course take a variety of forms,
including press fit rather than threaded caps.
[0066] Those skilled in the art will appreciate that nuts 415 are
not limited to a dual-head shape, but may be in the form of a
single cylinder with two threaded holes, or other shapes to
accommodate different arm rest support configurations, including
flanges or grooves to facilitate alignment of the threaded openings
with the slot 414.
[0067] In addition, washers 418, which have a curved lower surface
corresponding in shape to the curved surface of support 41 and a
counter sink at the top to receive the heads of screws 421, may
have a variety of shapes to accommodate different arm rest support
and screw head shapes.
[0068] When the cap screws are extended through the respective
openings in arm rest plates 42, washers 418, and slots 414, they
may be threaded into openings 417 to fixedly secure the arm rest
plates 42 to the support 414. However, as illustrated in FIG. 6,
because slots 414 are longer than the distance between openings 417
in each cylindrical nut 415, as illustrated in FIG. 6, when the cap
screws are loosed to permit relative movement between the nut and
the support 411, but not sufficiently to separate the cap screws
from the openings, the arm rest plates 42 may be slid in a
direction parallel to slots 414, and thereby laterally adjusted
relative to the support.
[0069] In addition, as illustrated in FIG. 7, because the slots 411
are wide enough to permit movement of the cap screws across the
width of the slots, i.e., in a tangential direction relative to
support 411, and because of the curved lower surface of washers
418, when the cap screws are loosened in the manner described
above, the arm rest assemblies can be swivelled or pivoted around
the axis of the support so that they tilt upwardly or downwardly,
or are horizontal, in accordance with the preference of the
rider.
[0070] Finally, the skew or angle of the arm rest plate 42 in the
horizontal plane, i.e., relative to a substantially vertical pivot,
may also be adjusted, upon loosening of the cap screws by an amount
sufficient to permit movement between the arm rest plates and
support 411 without separating the screws from the threaded
openings 417 in nuts 415, by pivoting the arm rest plates around
the respective cap screws extending through openings 422, which by
their circular nature providing a pivot point. Slots 423 have a
curvature that forms a constant radius with the center of openings
422, and thus the slots are capable of sliding relative to the cap
screws extending therethrough, allowing the entire arm plate to
pivot.
[0071] As illustrated, arm rest plates include two circular
openings 422 in each arm rest 42, and two slotted openings 423.
This permits the fore-to-aft position of the arm rests relative to
the support 411 to be adjusted by selectively using either the
forwardmost or rearward most one of the slots 422 and 423 as the
slots through which cap screws 421 and 422 are extended. This is an
optional feature, and it is within the scope of the invention to
use a single opening 422 and a single opening 423 in each arm rest
plate, or more than two of each type of opening to achieve finer
adjustment.
[0072] Additional optional features of the arm rest include slots
424 which reduce the weight of the plates and/or provide
ventilation. The arm rest plates may be padded (not shown) for
further comfort, coated with rubber, plastic, or the like, or even
made of a synthetic rather than metal material. Other parts of the
aerobar assembly may also be made of metal or other materials, the
materials of the various parts forming no part of the present
invention.
[0073] The final sub-assembly of the aerobar assembly illustrated
in FIG. 1 is the handlebar sub-assembly, which consists of a
handlebar 10, such as the one illustrated in FIG. 8, and C-clamps
or brackets 23. The brackets each include openings 231 for cap
screws 232, which are extended through the openings 231 and
threaded into openings 223 to secure the handlebar to the pillar
stem mount.
[0074] This arrangement permits a variety of different handlebar
configurations to be used with the aerobar assembly of the
invention. For example, the handlebar may correspond to handlebar
10 illustrated in FIG. 8, which is a drop style handlebar having
downwardly and inwardly curved drop extensions 12 and an oval base
bar 11; i.e., a base bar with an oval cross-section. Numerous other
cross-sectional base bar shapes can be accommodated by the
illustrated C-clamps, and if a different cross-sectional shape that
does not fit the illustrated C-clamps, the C-clamps can be replaced
by other clamp configurations, or by a suitably shaped or
configured bracket.
[0075] FIG. 9A shows an alternative pillar stem 500 that includes
several improvements/modifications of the stem illustrated in FIGS.
1-8. The first improvement is the inclusion of knee bumpers 501,
also shown in FIG. 9B, that fit over the rear and side portions of
cinch clamp 502 for clamping the stem 500 to the fork or steering
column 18 (see FIGS. 1B and 2) of the bicycle. The bumpers 501
preferably are molded of a recyclable thermal plastic elastomer,
although other cushioning materials may be substituted, and include
projections 503 that fit into holes 504 in the cinch clamp 502 to
secure the bumpers 501 to the cinch clamp 502. Because the bumpers
are made of an elastomeric material, they can be snapped onto and
removed from the cinch clamp without tools. The projections 503 are
dimensioned to fit into threaded or non-threaded openings in the
stem or in the cinch clamp fastener 505, as shown in FIG. 9B, and
the shape of the bumpers preferably ensures a snug fit. The purpose
of the bumpers is to lessen or prevent injuries such as cuts,
lacerations, abrasions, bruises, and breakage whenever a cyclist's
knee impacts the cinch clamp.
[0076] Also shown in FIG. 9A, and in FIGS. 11A and 11B, are
fasteners or bolts 510 for attaching handlebar clamps 511 to the
pillar stem 500. Bolts 510, and/or any other fasteners or bolts
used to attach various sub-assemblies to the pillar stem, are in
this embodiment made of titanium that has been treated with
physical vapor deposition (PVD). PVD treated titanium fasteners
have previously been used only in aerospace and Fl motorsport
applications. In addition to increased hardness, thereby making the
threaded shank and non-threaded body less susceptible to stripping
or fracturing, the PVD treated stem bolts have a color spectrum
coated finish, thereby allowing them to be used as an optional
marker for quality control (i.e., good stems will have colored
bolts whereas inferior stems will not). The PVD color spectrum
coated finish also absorbs the reflective glare from sunlight, in
contrast to naturally silver titanium stem bolts which reflect
harmful sunlight glare to a rider's eyes, harming vision and
reaction time, and permits the vivid detection of fastener cracks
or fissures so as to provide early detection of fastener failures.
Finally, PVD treated titanium bolts have lower friction loss that
makes the bolts less susceptible to galling, freezing, and/or
cracking when being torqued during installation, adjustment, or
removal.
[0077] FIG. 9A also shows a moisture outlet 512 for the upper
utility ports 513 of the stem. The upper utility ports 513 may be
used to attach the arm rest sub-assembly illustrated in FIGS. 1-8,
or other sub-assemblies such as aerobars or lights. However, when
upper utility ports 513 are not in use, because the arm rest
assembly is not required, dirt or moisture from sweat or rain,
represented by drop 514 illustrated in FIG. 12, may fall into and
collect in ports 513. To solve this problem, an outlet 512 on each
side of the pillar stem communicates with a respective bottom of
ports 513 to provide an outlet for moisture (represented by drop
514'). In addition, the outlets provide airflow to carry liquid
anodizing solution, allowing the ports to become fully anodized in
order to guard against corrosion, and also permit the use of
compressed air to blow away unwanted dirt, debris, and
moisture.
[0078] FIGS. 9A and 13 show a plug gasket 515 that may be used to
seal off unwanted dirt, debris, and moisture from the threads and
inner body of the stem's lower utility ports 516 when they are not
being used, for example to hold an aerobar sub-assembly as
illustrated in FIGS. 1-8. The plug gasket 515 is preferably made of
a recyclable thermal plastic elastomer (though other materials may
be substituted) and includes threaded cylindrical extensions 517
that have sufficient resilience to be pushed past and held by the
threads in ports 516 to removably secure the gasket to the pillar
stem.
[0079] Finally, FIGS. 10A-10H show a collar arrangement for varying
the angle of the pillar stem when attached to a bicycle steering
column or fork. The collar arrangement, which may be used with or
without any of the sub-assemblies illustrated in FIGS. 1-8 or the
additional features of FIGS. 9A, 9B and 11-13, allows for an
increase or decrease in stem angle to increase rider ergonomics and
operating efficiency by permitting the height of the handlebars 12
to be adjusted as illustrated in FIGS. 10A and 10B.
[0080] In the embodiment illustrated in FIG. 10B, the collar
arrangement includes two complementary collars 520 and 521 each
having an eccentric rim 522,523 and a cylindrical body 524,525
extending at a predetermined angle relative to the rim. In
addition, a gap 527 bisects the respective rims and bodies so as to
enable the collars to be fitted over the fork or steering column
18, and to provide a marker for angular positioning of the
collar.
[0081] As is best shown in FIG. 10C, as the collars are rotated
about a vertical axis, the angle of the cylindrical body 524,525
relative to the vertical axis changes. Reference numerals 520' and
521' indicate a first angle of collars 520 and 521; reference
numerals 520'' and 521'' indicate a second angle; and reference
numerals 520''' and 521''' indicate a third angle. As a result,
when the collars are fitted over the fork or steering column 18 and
the pillar stem 500 is clamped to the bodies 524,525, the angle of
the pillar stem varies accordingly, changing the height of the
handlebars 12, as indicated in FIG. 10C, which shows the various
pillar stem orientations corresponding to the rotational positions
indicated by reference numerals 520',521', 520'', 522'', and
520''', 521''' shown in FIG. 10B. FIG. 10D shows that a downward
rather than upward inclination can be achieved simply by exchanging
collars 520 and 521.
[0082] FIG. 10F shows various alternative configurations
522A,522B,522C of the rim. It will be appreciated that every pair
of collars should be engineered to retain the same bearing tension
and mounting position of the step onto the fork or steering column
tube, but that the collars may otherwise have any geometric shape
to fit the weight, durability, and clamping requirements of the
stem. The oval design, for example, offers a light weight design
with arc modification capabilities. The inner diameter of the
collar may of course be varied as necessary to fit the
corresponding outer diameter of the fork or steering column, which
is typically 28.6 mm for high end forks and 25.4 mm for low end
forks, though it is of course within the scope of the invention to
modify the collars to fit other types and sizes of fork or steering
column.
[0083] Whereas the regular handlebar stems only offer the
reciprocal of one angle, limiting riders to two angles (upwardly
inclined and downwardly inclined), the illustrated collars provide
an infinite number of stem angles, to which the pillar stem 500 can
be adjusted without removing the handlebar C-clamps. In addition,
the collar arrangement offers a taller surface for clamping the
stem onto the fork or steering column, thereby increasing the
cantilever beam to steering column stiffness and lessening its
torsion. The collars can be used to dampen road shock and low
vibrations by using different materials, such as carbon, urethane,
plastic, allow, and so forth, for adjusting ride feedback. Also,
the two-collar design facilitates removal of the stem from the fork
by dropping down when the clamp is loosened, exposing the larger
inner circumference of the stem to enable the stem to be easily
lifted off the fork. Variations of the collars illustrated in FIGS.
10G and 10H including forming the collar of a single cylindrical
member 530 for convenient installation, as illustrated in FIG. 10G,
or sculpting the collar to yield less mass for race competition, as
illustrated in FIG. 10H, in which material has been removed from
collars 528,529 relative to collars 520,521 shown in FIG. 10B.
[0084] Having thus described a preferred embodiment of the
invention in sufficient detail to enable those skilled in the art
to make and use the invention, it will be appreciated that numerous
variations of the illustrated embodiment may be made without
departing from the scope of the invention, such as use of different
types of screws or fasteners, different arm plate configurations,
different clamp configurations for the stem mount and the handlebar
mount, and so forth. It is accordingly intended that the invention
not be limited to the embodiment illustrated in the drawings or
accompanying description, but rather that it be defined solely in
accordance with the appended claims.
* * * * *