U.S. patent application number 10/669296 was filed with the patent office on 2004-03-25 for variable speed transmission for scooter.
This patent application is currently assigned to Patmont Motor Werks. Invention is credited to Patmont, Steven J..
Application Number | 20040055803 10/669296 |
Document ID | / |
Family ID | 31998169 |
Filed Date | 2004-03-25 |
United States Patent
Application |
20040055803 |
Kind Code |
A1 |
Patmont, Steven J. |
March 25, 2004 |
Variable speed transmission for scooter
Abstract
A small, motor-driven vehicle has at least one steered wheel and
at least one motor-driven wheel with the rider supported between
the wheels. The rider directs the steered wheel while applying
motor power through a throttle mechanism to the driven wheel. The
throttle mechanism includes a driven shaft from the motor
contacting the periphery of the driven wheel. This driven shaft has
an adjustable diameter. When the driven shaft is adjusted to have a
small diameter, the small, motor-driven vehicle is propelled at low
speed and high torque with optimum power transmission for
proceeding either uphill or over terrain presenting higher
resistance to vehicle passage. When the driven shaft is adjusted to
have a larger diameter, the small, motor-driven vehicle is
propelled at higher speed and lower torque, on the level, downhill
or over terrain presenting lower resistance to vehicle passage.
Accordingly, the adjustable diameter of the driven shaft permits
optimization of scooter torque and speed for proceeding with
optimum motor efficiency.
Inventors: |
Patmont, Steven J.;
(Gardnerville, NV) |
Correspondence
Address: |
TOWNSEND AND TOWNSEND AND CREW, LLP
TWO EMBARCADERO CENTER
EIGHTH FLOOR
SAN FRANCISCO
CA
94111-3834
US
|
Assignee: |
Patmont Motor Werks
Pleasanton
CA
|
Family ID: |
31998169 |
Appl. No.: |
10/669296 |
Filed: |
September 23, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60413319 |
Sep 24, 2002 |
|
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Current U.S.
Class: |
180/181 |
Current CPC
Class: |
B62M 6/10 20130101; B62M
6/35 20130101; B62K 3/002 20130101 |
Class at
Publication: |
180/181 |
International
Class: |
A63C 017/12 |
Claims
What is claimed is:
1. In a small, motor-driven vehicle having: at least one steered
wheel; a motor for driving the small, motor-driven vehicle; at
least one motor-driven wheel; a platform supporting the rider from
the at least one driven wheel wherein the rider supported on the
platform directs the steered wheel while applying power from the
motor through a throttle mechanism to the driven wheel; and, a
throttle mechanism for applying power from the motor to the driven
wheel; the improvement of a throttle mechanism comprising: a driven
shaft from the motor contacting the periphery of the driven wheel;
means for providing the driven shaft with an adjustable diameter
between a small diameter and a larger diameter when driving the
driven wheel whereby, when the driven shaft is adjusted to have a
small diameter, the small motor driven vehicle is propelled at low
speed and high torque, and when the driven shaft is adjusted to
have a large diameter, the small motor driven vehicle is propelled
at higher speed and lower torque.
2. The small, motor-driven vehicle according to claim 1 and
wherein: the small, motor-driven vehicle is a scooter.
3. The small, motor-driven vehicle according to claim 1 and
wherein: the means for providing the driven shaft with an
adjustable diameter includes two opposed parts for moving toward
and away from one another.
4. The small, motor-driven vehicle according to claim 3 and
wherein: the two opposed parts produce a larger diameter when moved
toward one another and produce a smaller diameter when moved away
from one another.
5. The small, motor-driven vehicle according to claim 1 and
wherein: the driven shaft is inflatable to provide a variable
diameter.
6. The small, motor-driven vehicle according to claim 5 and
wherein: the driven shaft when inflated provides a larger diameter;
and, the driven shaft when deflated provides a smaller
diameter.
7. In a small, motor-driven vehicle having: at least one steered
wheel; a motor for driving the small, motor-driven vehicle; at
least one motor-driven wheel; a platform supporting the rider from
the at least one driven wheel wherein the rider supported on the
platform directs the steered wheel while applying power from the
motor through a throttle mechanism to the driven wheel; and a
throttle mechanism for applying power from the motor to the driven
wheel; a process of driving the driven wheel through the throttle
mechanism comprises the steps of: providing a driven shaft from the
motor for contacting the periphery of the driven wheel; providing
the driven shaft with an adjustable diameter between a small
diameter and a larger diameter when driving the driven wheel;
adjusting the driven shaft to have a small diameter to propel the
driven wheel at low speed and high torque; and, adjusting the
driven shaft to have a larger diameter to propel the driven wheel
at high speed and low torque.
8. The process of driving the driven wheel through the throttle
mechanism of claim 7 and further including: mounting the driven
shaft on a pivot relative to the driven wheel; and, pivoting the
driven shaft toward and away from the wheel to apply power to the
driven wheel.
9. The process of driving the driven wheel through the throttle
mechanism of claim 7 and wherein the providing of the driven shaft
with an adjustable diameter includes the steps of: providing the
driven shaft with interlocking parts moving toward and away from
one another to provide a first shaft diameter in a first
toward-and-away position and to provide a second shaft diameter in
a second toward-and-away position; and, moving the interlocking
parts of the driven shaft to vary the torque and speed of the
driven wheel.
10. The process of driving the driven wheel through the throttle
mechanism of claim 9 and wherein: moving the interlocking parts of
the driven shaft away from one another to provide high torque and
low speed to the driven wheel.
11. The process of driving the driven wheel through the throttle
mechanism of claim 7 and wherein the step of providing the driven
shaft with an adjustable diameter includes: providing the driven
shaft with an inflatable diameter; inflating the driven shaft to
provide the driven wheel with high speed and low torque; and
deflating the driven shaft to provide the driven wheel with low
speed and high torque.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application claims the benefit of U.S. Provisional
Patent Application No. 60/413,319, filed Sep. 24, 2002,
incorporated herein by reference.
STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSORED
RESEARCH AND DEVELOPMENT
[0002] Not Applicable
Reference to a "Sequence Listing," a Table, or a Computer Program
Listing Appendix Submitted on a Compact Disk.
[0003] Not Applicable
[0004] This invention relates to small, motor-driven vehicles, such
as scooters and go-carts. More particularly, a driven shaft from
the vehicle motor for driving a driven wheel has an adjustable
diameter. When the driven shaft is adjusted to have a small
diameter, the small, motor-driven vehicle is propelled at low speed
and high torque. When the driven shaft is adjusted to have a larger
diameter, the small, motor-driven vehicle is propelled at higher
speed and lower torque. Accordingly, the adjustable diameter of the
driven shaft permits optimization of vehicle torque and speed.
BACKGROUND OF THE INVENTION
[0005] Go-carts and scooters powered by motors are known. By way of
example, see Patmont, U.S. Pat. 6,095,274, entitled Engine Drive
for Scooter, in which the rider of a scooter stands upon a scooter
platform and directs a foreword steered wheel while applying motor
power through a throttle mechanism to a rear driven wheel. In this
disclosure, the throttle mechanism includes an engine mounted on a
pivot arm offset from the axis of rotation of the rear driven wheel
of the scooter. This engine has a protruding driven shaft overlying
the driven wheel for moving into and out of contact with the
periphery of the driven wheel. Through offset mounting of the
engine pivot relative to the point of rear wheel rotation and the
periphery of the driven wheel, the driving shaft can be brought
into and out of contact with the rear driven wheel for controlled
propulsion of the scooter.
[0006] In this particular driving arrangement, the torque and speed
applied to the rear driven wheel is a function of two parameters.
First, the driven shaft must be in contact with the periphery of
the driven wheel. Second, the torque and speed of the motor is
transmitted through the driven shaft and directly transferred to
the driven wheel. As the torque and speed of the engine varies, the
torque and speed of the driven vehicle wheel varies.
[0007] Small, motor-driven vehicles, such as the scooter
illustrated in the Patmont '274 patent, are used on surfaces having
variable slopes and variable resistance to vehicle passage. It is
common for such small, motor-driven vehicles to proceed uphill, on
the level, and downhill. Further, it is common for such small,
motor-driven vehicles to be used on an all-terrain basis on rough,
sandy, or marshy ground where the resistance to the foreword
passage of the small, motor-driven vehicle is highly variable.
Given a driven shaft of constant diameter, the only variation of
torque and speed will be the variation of torque and speed of the
driving motor. This is not necessarily in the best interest of
efficient small, motor-driven vehicle propulsion.
[0008] Variable speed and torque transmissions are known. However,
virtually none of these is suitable for the simple environment of a
small, motor-driven vehicle, such as a scooter. Simply stated,
between the motor and driven wheel, there is no room for mechanical
complication. Simplicity is required in all these
transmissions.
BRIEF SUMMARY OF THE INVENTION
[0009] A small, motor-driven vehicle has at least one steered wheel
and at least one motor-driven wheel with the rider supported
between the wheels. The rider directs the steered wheel while
applying motor power through a throttle mechanism to the driven
wheel. The throttle mechanism includes a driven shaft from the
motor contacting the periphery of the driven wheel. This driven
shaft has an adjustable diameter. When the driven shaft is adjusted
to have a small diameter, the small, motor-driven vehicle is
propelled at low speed and high torque with optimum power
transmission for proceeding either uphill or over terrain
presenting higher resistance to vehicle passage. When the driven
shaft is adjusted to have a larger diameter, the small,
motor-driven vehicle is propelled at higher speed and lower torque,
on the level, downhill or over terrain presenting lower resistance
to vehicle passage. Accordingly, the adjustable diameter of the
driven shaft permits optimization of scooter torque and speed for
proceeding with optimum motor efficiency.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] FIG. 1 is a side elevation view of a small, motor-driven
vehicle, here shown as a scooter, illustrating the front steered
wheel, the rear driven-wheel, and the rider supporting platform
supported between the two wheels;
[0011] FIG. 2 is an enlarged side elevation similar to FIG. 1
illustrating the throttle mechanism of the Patmont '274 patent with
the invention of this disclosure schematically shown in broken
lines;
[0012] FIG. 3 is a first schematic of the drive mechanism shown in
FIG. 2 illustrating the driven shaft with a small diameter for
driving the driven wheel with high torque and low speed;
[0013] FIG. 4 is a second schematic of the drive mechanism shown in
FIG. 2 illustrating the driven shaft with a larger diameter for
driving the driven wheel with lower torque and higher speed;
[0014] FIGS. 5A and 5B are first and second views of a mechanism
having opposed interlocking parts for producing a variable diameter
driven shaft with FIG. 5A illustrating the mechanism having a small
diameter when fully expanded with one interlocking part away from
the other interlocking part, and FIG. 5B illustrating the mechanism
having a larger diameter when contracted with one interlocking part
moved toward the other interlocking part; and,
[0015] FIGS. 6A and 6B are first and second views of an inflatable
variable diameter driven shaft with FIG. 6A illustrating the
mechanism having a small diameter when deflated and FIG. 6B
illustrating the mechanism having a larger diameter when
inflated.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Referring to FIG. 1, the small, motor-driven vehicle is
shown as scooter S. Scooter S can be easily understood. Scooter S
includes standing platform P, front steered wheel F and rear driven
wheel R. Engine E drives rear driven wheel R in the apparatus
disclosed herein.
[0017] Scooter S includes steering handle 14, which rotates on head
tube H. The single structural member of the scooter chassis is main
structural tube T. Main structural tube T connects to head tube H
at the front, supports standing platform P in the middle via
couplings 28 and 29 and terminates at rear tire mounting section
32. Referring specifically to FIG. 2, it will be seen that main
structural tube T has side-displacing section 30 followed by rear
tire mounting section 32. Rear tire mounting section 32 supports
rear driven-wheel R via axle 34.
[0018] Having generally set forth the construction of scooter S,
attention will be given first to the physical mounting of engine E
to main structural tube T and, second, to the mechanics of the
driving of rear driven wheel R.
[0019] Referring to FIG. 2, engine E is mounted on pivot V. As can
be seen in FIG. 4, engine E has a protruding driving shaft D, which
here rotates at the same speed as engine E. Protruding driving
shaft D directly contacts peripheral surface 40 of rear driven
wheel R. It will be understood that when protruding driving shaft D
is in contact with ground contact surface 40 and engine E is
operating, scooter S will be driven.
[0020] Attention will now be devoted to the drive schematic of FIG.
3. Rear driven wheel R turns on axle 34. To understand the physics
of this invention, note that radial 44 has been drawn from
protruding driving shaft D and its contact point on the periphery
40 of rear driven wheel R.
[0021] Pivot V is offset with respect to this radial 44.
[0022] Specifically, pivot V should have an angle of 10.degree. to
40.degree. relative to the point of contact between protruding
driving shaft D and peripheral surface 40. This range can be
narrowed to be between 15.degree. and 30.degree., and more
optimally is 20.degree..
[0023] Further, the length of pivot arm 48 is preferably less than
the length of radial 44 by a ratio of about 60% to 90% in a broad
range, 70% to 80% in a medium range, and about 75% as shown in the
preferred embodiment.
[0024] It will further be noticed that protruding driving shaft D
swings in an arc 50. Arc 50 will be seen to intersect the periphery
40 of rear driven wheel R at an acute angle alpha.
[0025] Having set forth this construction, the interaction of
protruding driving shaft D and rear driven wheel R during vehicle
operation can now be set forth.
[0026] Specifically, and as illustrated in FIG. 3, rear driven
wheel R turns counterclockwise. Protruding driving shaft D turns
clockwise. Taking the reactive force from protruding driving shaft
D, it will be understood that engine E on pivot arm 48 drives
protruding shaft D counterclockwise and into contact with the
periphery 40 of rear driven wheel R.
[0027] Given the position of pivot V, it will be understood that
protruding driving shaft D moves along arc 50. This arc 50 contacts
peripheral surface 40 of the driven wheel at a shallow (acute)
angle. As a result of this motion, firm driving contact takes
place--even in the absence of any other biasing forces present.
[0028] In the preferred embodiment, two biasing forces are present.
One is the weight of engine E. The remaining force is supplied by
tension from coil spring 52, which extends from the distal end of
main structural tube T to engine E.
[0029] Referring to FIGS. 1 and 3, it will be understood that the
motion of engine E and protruding driving shaft D into rear driven
wheel R at peripheral surface 40 must be controlled. Precise
control of this motion gives corresponding precise control of the
motion of scooter S. This being the case, a cable control lever,
such as derailleur cable ratchet 54 acting on cable 56, limits such
contact., By the simple expedient of tensioning cable 56 through
cable control lever 54, precision control of the scooter driving
force occurs.
[0030] It should be understood that the drive here disclosed does
not appreciably affect the placement of fender 58, which hinges to
the chassis. Likewise, a conventional scooter brake 58 can be
utilized.
[0031] It will be understood that where scooter S is used off road,
it is possible to completely disengage engine E from rear driven
wheel R. In this case, pushing or coasting of scooter S can occur
in a conventional manner.
[0032] Thus far, the transmission of this invention has not been
differentiated from that transmission set forth in the Patmont '274
patent, although it will be understood that the embodiments of
FIGS. 1, 2, 3, and 4 all incorporate this invention. Comparing
driven shaft D' of FIG. 4 to driven shaft D of FIG. 3, the
principle on which this invention operates can be readily
understood.
[0033] The size of driven shaft D' is larger in diameter than
driven shaft D of FIG. 3. Accordingly, rotation of driven shaft D'
wheel drives the driven wheel R at a higher speed and lower torque
from engine E. Understanding this much, what is needed is a
mechanism for changing the diameter of rotating shaft D from its
small diameter shown in FIG. 3 to the larger diameter shown in FIG.
4.
[0034] Before moving on to an explanation of these mechanisms, it
is important to note with respect to FIG. 4, and the drive swinging
axis there illustrated, that the larger diameter of driven shaft D'
does not interfere with the operation of the transmission thus far
described. The only consequence of the larger diameter driven shaft
is that the engagement of the driven shaft with the periphery of
driven wheel R occurs at a different angular interval of the engine
E on the drive pivot position.
[0035] As of the writing of this Provisional Patent Application,
the optimum mechanism for expanding and contracting the diameter of
driven shaft D to driven shaft D' is being selected. At present,
two mechanisms are shown for accomplishing this purpose. The
mechanism of FIGS. 5A and 5B, illustrates opposed conical splines.
The mechanism of FIGS. 6A and 6B, illustrates an inflatable driven
shaft. Using either alternative, the objectives sought by this
disclosure can be realized.
[0036] Referring to FIG. 5A opposed conical spline sections 70A and
70B are illustrated. Each spline section fastens to a cylindrical
base 72 and has tapering, alternating, conical splines concentric
about axis 74 of engine E rotation. In the view of FIG. 5A, spline
sections 70A and 70B are remote one from another. In the view of
FIG. 5B, spline sections 70A and 70B have been moved toward one
another. Such movement is urged by wire 76 concentric to the
rotating conical spline sections 70A and 70B. The reader will
appreciate that if tension is not exerted by wire 76 drawing the
respective splines sections towards one another, the natural
tendency of the spline sections will be to move away, one from the
other.
[0037] Control of the mechanisms of FIGS. 5A and 5B can be easily
understood. Specifically, derailleur cable ratchet (not shown)
acting on wire 76 can produce, through the tension on the wire, the
desired driven shaft diameter. At the same time, the respective
conical spline sections will provide the requisite traction to the
driven wheel R.
[0038] Referring to FIGS. 6A and 6B, an even simpler mechanism is
illustrated. In this mechanism, driven shaft D is given an
inflatable exterior 80. In FIG. 6A, inflatable exterior 80 is
deflated through inflation conduit 82. As a result, driven shaft D
has a small diameter and drives driven wheel R at low speed and
high torque.
[0039] Referring to FIG. 6B, inflatable exterior 80 of driven shaft
D' is inflated through inflation conduit 82. As a result, driven
shaft D' has a large diameter and drives driven wheel R at high
speed and lower torque.
[0040] The reader will understand that this Provisional Patent
Application is intended to cover any mechanism which provides for
the convenient expansion and contraction of the driven shaft D, D'.
It is anticipated that other preferred embodiments of this
mechanism will be identified by the time a non-provisional patent
application is filed.
* * * * *