U.S. patent application number 09/901485 was filed with the patent office on 2003-01-09 for motorcycle frame having integral fuel storage unit and break-away steering head.
This patent application is currently assigned to Buell Motorcycle Company. Invention is credited to Askenazi, Abraham, Buell, Erik F., Ferguson, Donald S., Hoechst, Dane J., Strader, Vance C., Wightman, Todd R..
Application Number | 20030006579 09/901485 |
Document ID | / |
Family ID | 25414272 |
Filed Date | 2003-01-09 |
United States Patent
Application |
20030006579 |
Kind Code |
A1 |
Buell, Erik F. ; et
al. |
January 9, 2003 |
MOTORCYCLE FRAME HAVING INTEGRAL FUEL STORAGE UNIT AND BREAK-AWAY
STEERING HEAD
Abstract
The present invention includes a motorcycle frame that has a
steering head and a fuel storage unit that is adapted to contain
motorcycle fuel. A separating wall is disposed between the fuel
storage unit and the steering head to substantially prevent fluid
communication between the fuel storage unit and the steering head.
The steering head includes a stress focusing structure for
separating the steering head from the fuel storage unit and leaving
the separating wall substantially intact to contain fuel within the
fuel storage unit in response to a predetermined force being
applied to at least one of the steering assembly and the front
wheel.
Inventors: |
Buell, Erik F.; (Mukwonago,
WI) ; Wightman, Todd R.; (Waukesha, WI) ;
Hoechst, Dane J.; (Elkhorn, WI) ; Strader, Vance
C.; (New Berlin, WI) ; Ferguson, Donald S.;
(Pell Lake, WI) ; Askenazi, Abraham; (Burlington,
WI) |
Correspondence
Address: |
MICHAEL BEST & FRIEDRICH, LLP
100 E WISCONSIN AVENUE
MILWAUKEE
WI
53202
US
|
Assignee: |
Buell Motorcycle Company
East Troy
WI
|
Family ID: |
25414272 |
Appl. No.: |
09/901485 |
Filed: |
July 9, 2001 |
Current U.S.
Class: |
280/279 |
Current CPC
Class: |
B62K 11/08 20130101;
B62J 35/00 20130101; B62K 19/32 20130101 |
Class at
Publication: |
280/279 |
International
Class: |
B62M 007/00 |
Claims
1. A motorcycle comprising: a frame including at least one hollow
beam adapted to contain motorcycle fuel, a steering head, and a
separating wall disposed between said hollow beam and said steering
head to prevent communication between said hollow beam and said
steering head; a rear wheel interconnected with said frame to
support a rear portion thereof; a steering assembly pivotably
mounted to said steering head; and a front wheel rotatably mounted
to said steering assembly; wherein said steering head includes a
stress focusing structure for separating said steering head from
said hollow beam and leaving said separating wall substantially
intact to contain fuel within said hollow beam in response to a
predetermined force being applied to at least one of said steering
assembly and front wheel.
2. The motorcycle of claim 1, wherein said stress focusing
structure includes a notch formed in a wall of said steering
head.
3. The motorcycle of claim 1, wherein said stress focusing
structure includes a squared junction between said separating wall
and said steering head.
4. The motorcycle of claim 1, wherein said stress focusing
structure includes a strengthening rib at the connection between
said separating wall and said hollow beam.
5. The motorcycle of claim 1, wherein said stress focusing
structure is interposed between a portion of said steering head and
said separating wall.
6. The motorcycle of claim 1, wherein said steering head and
separating wall are integrally formed with each other.
7. The motorcycle of claim 1, wherein said at least one hollow beam
includes first and second hollow beams spaced apart from each
other.
8. The motorcycle of claim 7, further comprising at least one
joining portion communicating between said first and second hollow
beams.
9. The motorcycle of claim 8, wherein said at least one joining
portion includes first and second joining portions, said first
joining portion communicating between first ends of said first and
second hollow beams and said second joining portion communicating
between second ends of said first and second hollow beams, said
beams and joining members defining a generally ring-shaped fuel
storage cavity within said frame.
10. A motorcycle frame comprising: at least one hollow beam adapted
to contain motorcycle fuel; a steering head; a separating wall
disposed between said hollow beam and said steering head to prevent
communication between said hollow beam and said steering head; and
a stress focusing structure for separating said steering head from
said hollow beam and leaving said separating wall substantially
intact to contain fuel within said hollow beam in response to a
predetermined force being applied to said steering head.
11. The frame of claim 10, wherein said stress focusing structure
includes a notch formed in a wall of said steering head.
12. The frame of claim 10, wherein said stress focusing structure
includes a squared junction between said separating wall and said
steering head.
13. The frame of claim 10, wherein said stress focusing structure
includes a strengthening rib at the connection between said
separating wall and said hollow beam.
14. The frame of claim 10, wherein said stress focusing structure
is interposed between a portion of said steering head and said
separating wall.
15. The frame of claim 10, wherein said steering head, hollow beam,
and separating wall are integrally formed with each other.
16. The frame of claim 10, wherein said at least one hollow beam
includes first and second hollow beams spaced apart from each
other.
17. The frame of claim 16, further comprising at least one joining
portion communicating between said first and second hollow
beams.
18. The frame of claim 17, wherein said at least one joining
portion includes first and second joining portions, said first
joining portion communicating between first ends of said first and
second hollow beams and said second joining portion communicating
between second ends of said first and second hollow beams, said
beams and joining members defining a generally ring-shaped fuel
storage cavity within said frame.
Description
BACKGROUND
[0001] The invention relates to a motorcycle frame structure and
more specifically, to frame structures having integral fuel
tanks.
[0002] Most motorcycles include a frame assembly to which an
engine, transmission, and fuel tank are mounted. U.S. Pat. No.
4,951,774 discloses a frame assembly in which fuel is stored within
the frame structure to save room. With such a design, a separate
fuel tank is not required.
SUMMARY
[0003] The present invention is an improvement over the combination
frame and fuel tank disclosed in U.S. Pat. No. 4,951,774. The
present invention provides a motorcycle including a frame having a
steering head, a rear wheel interconnected with the frame for
rotation with respect to the frame, a steering assembly pivotably
mounted to the steering head; and a front wheel rotatably mounted
to the steering assembly.
[0004] The frame also includes a fuel storage unit that is adapted
to contain motorcycle fuel. A separating wall is disposed between
the fuel storage unit and the steering head to prevent fluid
communication between the fuel storage unit and the steering head.
The steering head includes a stress focusing structure for
separating the steering head from the fuel storage unit and leaving
the separating wall substantially intact to contain fuel within the
fuel storage unit in response to a predetermined force being
applied to at least one of the steering assembly and the front
wheel.
[0005] Other features and advantages of the invention will become
apparent to those skilled in the art upon review of the following
detailed description, claims, and drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] FIG. 1 is a side view of a motorcycle embodying the
invention.
[0007] FIG. 2 is an exploded view of the frame and an air box
assembly of the motorcycle in FIG. 1.
[0008] FIG. 3 is a bottom perspective view of the frame.
[0009] FIG. 4 is cross-section view taken along line 4-4 in FIG.
2.
[0010] Before one embodiment of the invention is explained in
detail, it is to be understood that the invention is not limited in
its application to the details of construction and the arrangements
of the components set forth in the following description or
illustrated in the drawings. The invention is capable of other
embodiments and of being practiced or being carried out in various
ways. Also, it is understood that the phraseology and terminology
used herein is for the purpose of description and should not be
regarded as limiting. The use of "including" and "comprising" and
variations thereof herein is meant to encompass the items listed
thereafter and equivalents thereof as well as additional items. The
use of "consisting of" and variations thereof herein is meant to
encompass only the items listed thereafter. The use of letters to
identify elements of a method or process is simply for
identification and is not meant to indicate that the elements
should be performed in a particular order.
DETAILED DESCRIPTION
[0011] FIG. 1 illustrates a motorcycle 10 that includes a frame 12
and an engine 14 and transmission 16 supported by the frame 12. The
frame 12 is supported by a rear wheel 18 that is interconnected to
the frame 12 by way of a swingarm 20. The swingarm 20 is pivotally
connected at one end to the transmission 16, or, alternatively, to
the frame 12 and/or transmission 16. The rear wheel 18 is driven by
the engine 14 through the transmission 16 and a flexible drive
member such as a chain or the illustrated drive belt 21. A front
wheel 22 supports the front of the motorcycle 10. A steering
assembly 24 is interconnected between the front wheel 22 and a
steering head 26 of the frame 12. The steering assembly 24 includes
a triple tree 28, handlebars 30, a steering column 31 (FIG. 4), and
a pair of fork members 32 straddling the front wheel 22.
[0012] Turning to FIGS. 2 and 3, the frame 12 includes a fuel
storage unit 34 that is used to contain motorcycle fuel and
communicate with the engine 14 through fuel lines 35 (FIG. 3) for
the delivery of fuel to the engine 14. The fuel storage unit 34 is
preferably an integral portion of the frame 12. The fuel storage
unit 34 includes a pair of hollow beams 36 that extend rearwardly
from the front of the motorcycle 10. The hollow beams 36 are
positioned on opposite sides of and space equally from a frame
longitudinal axis 37.
[0013] The hollow beams 36 are connected together at their front
ends by a forward portion 38 and at their rear ends by a rearward
portion 40. The forward and rearward portions 38, 40 are hollow and
communicate between the hollow beams 36. Preferably, the forward
and rearward portions 38, 40 and the hollow beams 36 form a
continuous hollow cavity 41 (FIG. 4) that forms an enclosed loop.
The forward portion 38 includes a filler opening 42 that
communicates with the cavity 41. The rearward portion 40 includes
an aperture 44 (FIG. 3) that is adapted to receive a fitting 45
which is connected to the fuel lines 35.
[0014] The motorcycle 10 includes an air box 46 (FIG. 2) that is in
fluid flow communication with the engine 14 to provide combustion
air thereto. The air box 46 is mounted to the frame 12 on an air
box support 48. The illustrated air box 46 may be larger than
typical air boxes due to the space made available by incorporating
the fuel storage unit 34 into the frame 12. An air passage 50
extends generally perpendicular to the frame longitudinal axis 37
through the front portion of the frame 12 to provide combustion air
to air box 46.
[0015] The steering head 26 is a generally hollow cylindrical
structure that includes a top end 52 and a bottom end 54. The top
end 52 includes a top counter bore 56 and the bottom end 54
includes a bottom counter bore 58 that is substantially aligned
with the top counter bore 56. The counter bores 56, 58 support the
steering column 31 for pivotal movement. The steering head 26 is
separated from the fuel storage unit 34 by a separating wall 60.
The separating wall 60 defines the front end of the fuel storage
unit 34 to substantially prevent flow of fuel from the fuel storage
unit 34 into the steering head 26. The steering head and separating
wall 60 are preferably made of cast aluminum and are preferably
formed integrally with each other in a permanent mold casting
process.
[0016] Referring to FIG. 4, the top 52 of the steering head 26 is
connected to the separating wall 60 by a stress focusing structure,
which includes a notch 64 and a squared junction 66 in the
illustrated embodiment. In addition, the stress focusing structure
includes a strengthening rib 68 at the connection between the fuel
storage unit 34 and the separating wall 60. It should be noted that
the stress focusing structure could include any configuration that
significantly weakens the connection between the steering head 26
and separating wall 60 and/or any configuration that significantly
strengthens the connection between the fuel storage unit 34 and the
separating wall 60.
[0017] The stress focusing structure is sufficiently strong
structurally to avoid breaking during normal operation of the
motorcycle 10. The stress focusing structure creates a tri-axial
state of stress upon the application of a predetermined amount of
force from the front (e.g., a frontal collision) on the steering
assembly 24 or the front wheel 22. For example, in a frontal
collision when the steering assembly 24 is forced to pivot about
the bottom end 54 of the steering head 26, the top end 52 of the
steering head 26 pulls away from the separating wall 60. The stress
focusing structure allows the fracture to originate at and
propagate along the steering head 26 away from the separating wall
60. In contrast, if the weakest point was not located within the
steering column but was located on the other side of the separating
wall 60, the collision would potentially expose fuel to the
environment.
[0018] The stress focusing structure therefore causes the steering
head 26 to be separated from the fuel storage unit 34 while leaving
the separating wall 60 substantially intact. The steering head 26
may thus be termed a "break-away" steering head 26. The likelihood
of a fuel spill in the event of a front collision is reduced by the
illustrated structure because the separating wall 60 remains
substantially intact.
* * * * *