US20030221888A1

US20030221888A1 - Motor retrofit for scooter

Info

Publication number: US20030221888A1
Application number: US10/262,990
Authority: US
Inventors: Edward McKinney; Andrew Parker; Jesse Patterson; Charles Taylor
Original assignee: Sharper Image Corp
Current assignee: Sharper Image Corp
Priority date: 2002-05-29
Filing date: 2002-10-02
Publication date: 2003-12-04

Abstract

The present invention is a retrofit kit that mechanically attaches to a push scooter. The retrofit kit converts the push scooter into an electrically driven scooter. The retrofit kit includes a bracket that may attach to the rear fork of the scooter so that the existing components of the scooter do not need to be modified. Components of the retrofit kit can also be used to originally manufacture the scooter. A motor assembly and a battery are supported on the scooter. The motor assembly includes a roller that frictionally engages and drives the rear wheel of the scooter when an individual activates a throttle assembly. In another embodiment, the motor assembly is located between a floorboard and a rear wheel and a foot brake is located aft of the rear wheel.

Description

PRIORITY CLAIM

This application claims priority from U.S. Provisional Patent Application No. 60/385,698, filed on Jun. 4, 2002, and this application claims priority from U.S. Provisional Patent Application No. 60/384,053, filed on May 29, 2002. Each of these provisional patent applications is being incorporated herein by this reference.[0001]

FIELD OF THE INVENTION

The present invention generally relates to a device that converts a manual push scooter into an electrically powered scooter. More specifically, an embodiment of the present invention is a retrofit kit that includes a motor assembly to frictionally drive a wheel of the scooter.

BACKGROUND OF THE INVENTION

Most scooters are designed and manufactured primarily for recreational use. Manually powered scooters are well known as efficient means for transportation. Such scooters are propelled by the rider using a single stride with one leg, while the other leg and foot are maintained in contact with the rider platform. The front wheel of the scooter is steered by a handle bar that is also connected to the platform. Most commonly, a push scooter has a foot brake located proximate to and above the rear wheel. A rider may slow the scooter down by depressing the foot brake downward, bringing the foot brake into contact with the rear wheel and frictionally slowing the rotation of the rear wheel.

An example of a folding collapsible push scooter is shown in FIG. 1. The

scooter

10 includes a footboard 11, a rear wheel 14, a foot brake 16, a front fork assembly 18, a collapsible connecting bar 22, a front wheel 24, and a handle bar 26. The footboard 11 is the main area where the rider stands while driving or operating the scooter. The handle bar 26 is mounted to and supported by the connecting bar 22. The connecting bar 22 is pivotally mounted onto the fork assembly 18, allowing a rider to turn the front wheel 24 left and right. The connecting bar 22 may telescope up and down, allowing the rider to adjust the height of the handle bar 26. The rear wheel 14 is secured relative to the footboard 11 by a rear axle 30 mounted through a rear fork 32 extending rearwardly from footboard 11. The foot brake 16, as shown in FIG. 1, is commonly located over the rear wheel 14, so that the rider may easily keep one foot on the footboard 11 while the other foot operates the foot brake 16.

One reason the scooter is so popular is that the scooter can be folded into a compact structure, making it easy to carry and store when not in use. For example, the

fork assembly

18 may pivot between an operative or extended position, as shown in FIG. 1, and a non-operative or collapsed position where the connecting bar 22 is substantially parallel to the footboard 11.

Electrically powered scooters have begun to replace push scooters. An electric scooter eliminates the need for the rider to push on the ground to propel the scooter forward. Instead, the rear wheel is electrically driven when a throttle assembly, commonly located on the handlebar, is activated by the user. A manual foot brake is still commonly used to frictionally slow the scooter down. Over the years, the electrically powered scooter has become the preferred type of scooter.

There are still many manual push scooters on the market today. For example, the Razor™ scooter has several models of manual push scooters such as the RZ Cruiser™ and the RZ Ultralite™. Such scooters are being used today. Owners of a manual push scooter may not wish to buy a new, more expensive electric scooter. Thus, there is a need to provide an apparatus to convert existing manual push scooters into electrically powered scooters at a low cost.

SUMMARY OF THE INVENTION

An aspect of the present invention is to provide an apparatus that can attach to a manually powered scooter and convert the manual push scooter into an electrical scooter. An embodiment of the present invention connects to the rear fork of the manually powered scooter. Once attached, a roller frictionally engages and drives the rear wheel to propel the scooter.

Another aspect of the present invention is to attach an apparatus to a scooter that will not require modifying any of the existing components. An embodiment of the present invention does not reduce the existing footboard space that a user stands on when riding the scooter or alter the existing foot brake system of the scooter.

In a further aspect of the invention, the motor is mounted between a floorboard and a rear wheel, with a foot brake located aft of the motor.

Yet another aspect of the present invention is to allow a user to electrically control the speed of the scooter. An embodiment of the present invention includes a throttle assembly that mounts onto the handlebar of the scooter. In this embodiment, a throttle handle is electrically connected to a motor assembly and a battery. The speed of the motor is controlled by activating the throttle handle.

Still another aspect of the present invention is to provide an apparatus that has easily replaceable parts. An embodiment of the present invention has a removable friction roller that can be replaced when it degrades or wears out. Another embodiment of the present invention has a removable battery housing so that a battery stored within the housing can be conveniently removed and recharged.

Another embodiment of the present invention has a motor cut-off switch that will prevent the rider from burning out or destroying the motor. In one embodiment, the motor is electrically isolated from the battery and throttle assembly when the foot brake is activated.

A further embodiment of the present invention is to allow a rider the flexibility to either manually push the scooter or electrically propel the scooter. One embodiment has a roller positioning mechanism for holding the roller against the rear wheel or maintaining the roller away from the rear wheel.

Further, an embodiment of the invention includes a robust attachment device to secure the battery and also the motor to the scooter.

Other aspects and features of the invention can be found in the specification, drawings and claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a folding collapsible push scooter, according to the prior art. [0017]
FIG. 2 is a perspective view of an embodiment of the present invention attached to the push scooter shown in FIG. 1. [0018]
FIG. 3 is a partial exploded view of the embodiment of the present invention shown in FIG. 2. [0019]
FIG. 4 is an exploded view of an embodiment of the motor assembly of FIG. 3, according to the present invention. [0020]
FIG. 5 is a perspective view illustrating the roller removed from the motor assembly of the embodiment of FIG. 2 of the invention. [0021]
FIGS. [0022] 6A-6C, FIG. 6A is a top view of the embodiment of FIG. 2 of the present invention in an engaged position; FIG. 6B is a side partial cutaway view along line C-C in FIG. 6A; FIG. 6C is a sectional view of area D indicated in FIG. 6B.
FIGS. [0023] 7A-7C, FIG. 7A is a top view of the embodiment of FIG. 2 of the present invention in a disengaged position; FIG. 7B is a side partial cutaway view along line B-B shown in FIG. 7A; FIG. 7C is a sectional view of area E shown in FIG. 7B.
FIG. 8 is a perspective view of an alternate embodiment of the motor assembly of the invention. [0024]
FIG. 9 is a side view of the alternate motor assembly of the invention shown in FIG. 8. [0025]
FIG. 10 is a sectional view of the motor assembly of the invention shown in FIG. 8. [0026]
FIG. 11 is a perspective view of the internal components of the motor assembly of the invention shown in FIG. 8. [0027]
FIG. 12 is a perspective view of the internal components of the motor assembly of the invention shown in FIG. 8 in a disassembled state. [0028]
FIG. 13 is an exploded perspective view of a battery and a battery mount of an embodiment of the invention. [0029]
FIG. 14 is a perspective view of a battery of the embodiment of FIG. 13 of the invention mounted on the battery mount shown in FIG. 13.[0030]

DETAILED DESCRIPTION OF THE PRESENT INVENTION

The present invention will be described in reference to FIGS. [0031] 2-14. FIG. 2 illustrates the retrofit kit 100 attached to the rear fork 32 of the scooter. The retrofit kit 100 includes a mounting bracket 102, a battery housing 104 and a motor assembly 106. The mounting bracket 102 is the main support for both the battery housing 104 and the motor assembly 106. In a preferred embodiment, as shown in FIG. 2, the retrofit kit 100 mounts on the rear fork 32 and extends from the rear of the scooter. This design does not require modifying any of the parts of the scooter, and does not interfere with the operation of any of the parts of the scooter. For example, the mounting bracket 102 forms around the rear tire 14 and the foot brake 16 when mounted to the scooter. As the mounting bracket 102 is the main structure to support all the components of the retrofit kit 100, the mounting bracket 100 should be a rigid structure. The mounting bracket 102 may be manufactured from materials such as, but not limited to, aluminum, steel, and stainless steel. It is within the scope of the present invention for the mounting bracket 100 to be manufactured from other materials.
The mounting [0032] bracket 102 secures to the scooter by two flanges 108. In one embodiment, each flange 108 has a “U”-shaped channel 110 located on the interior of each end 111. The width of each “U”-shaped channel 110 is preferably slightly larger than the width of each rear fork 32. Additionally, the distance between the two flanges 108 is preferably substantially similar to the width between the rear forks 32. These dimensions allow each “U”-shaped channel 110 to slide over the outside surface of the rear fork 32, yet at the same time provide a rigid connection between the bracket 102 and the rear fork 32. As shown in FIG. 2, the platform 103 that the battery housing 104 is secured to is horizontal. However, it is within the scope of the present invention for the platform 103 to be at an angle when the bracket 102 is mounted on the scooter.
The mounting [0033] bracket 102 is held stationary relative to the scooter by the rear axle 30. That is, the mounting bracket 102 cannot slide onto the rear fork 32 while the rear axle 30 is in place. To install the bracket 102, a user should first remove the rear axle 30. Removing the rear axle 30 disengages the rear wheel 14 from the rear fork 32. After removing the rear axle 30, the user should align the channels 110 with the rear forks 32 and slide the flanges 108 over the rear forks 32 until the bore 112 in the flange 108 aligns with the axle hole in the rear fork 32. Once the mounting bracket 102 is aligned with the rear fork 32, the rear axle pin 30 may be re-inserted. In effect, the rear axle 30 functions as the rotation axis for the rear wheel 14 and prevents translation of the bracket 102 relative to the scooter.
The power for the [0034] retrofit kit 100 is supplied by a battery 156 (see FIGS. 6B and 7B). The above battery housing 104 encases the battery 156. The battery housing 104 prevents an individual from accessing and touching the battery terminals. In the embodiments shown in FIG. 2 as described above, the bracket 102 has a platform 103 that the battery housing 104 mounts to, and rests upon. As shown in FIG. 3, an alternate embodiment of the battery housing 104 is a two-piece container. By way of example only, the housing 104 may be manufactured from ABS plastic. In one embodiment, the two halves of the housing are ultrasonically welded together to form a single unit. However, in alternate embodiments, the two halves of the housing 104 may be fastened together by any method as long as the halves can be repeatedly separated (e.g., fasteners, clamps or bolts). Methods to attach and repeatedly separate two halves of a housing are known to those skilled in the art. In the embodiment shown in FIG. 3, the housing 104 has an access hole (not shown) in the side or bottom to allow the cable 162 (FIG. 2) to enter the battery housing 104 and electrically connect to the battery 156. In one embodiment, the battery 156 is secured within the housing 104 so that the battery 156 will not move or slide around within the battery housing 104 during operation of the scooter. For example, scooters are driven on many different types of terrain, such as on smooth streets and bumpy sidewalks. The housing 104 is preferably fastened to the platform 103 to prevent the housing 104 from falling or sliding off the platform 103 during operation of the scooter. By way of example only, the housing 104 may be attached to the platform 103 by a latch, a bolt or any other type of fastening mechanism. Alternate embodiments can include a fastening plate 105 that attaches to the housing 104 and the platform 103 (see FIG. 3). In one embodiment, the fastening plate 105 and the housing 104 have a quick-release mechanism, allowing the user to easily disconnect the plate 105 or the housing 104 from the bracket 102.
FIG. 4 illustrates one embodiment of the components of the [0035] motor assembly 106. In the embodiment shown in FIG. 4, a motor housing, comprised of a first half 120 and a second half 122, encloses and supports a motor 114, a roller 116 and a torsional spring 118. The first half 120 of the motor housing has a motor shaft bore 124, a support column 126, and a pulley shaft bore 130. When the motor housing is assembled, the bore 124 aligns with the motor shaft 135. The motor shaft 135 passes through the bore 124 and extends out of the motor housing. The support column 126 has a cavity that a first end 127 of the pivot shaft 128 extends into such that the pivot shaft 128 can rotate within the support column 126. In the embodiment shown in FIG. 4, the pulley shaft bore 130 is located below the pivot shaft 128 and aligns with the second timing belt pulley 132.
The [0036] second half 122 of the motor housing is a mirror image of the first half 120 and includes a motor support, a support column 138, and an axle bore 140. The motor support aligns with the stationary motor shaft 135. Thus, the motor 114 is supported by the motor shaft bore 124 and the motor support 134 when the first half 120 and second half 122 are secured together. The support column 138 has a cavity similar to the support column 126 for accepting the second end 129 of the pivot shaft 128 and the bore 140 aligns with, and supports, the axle bearing 142.
The [0037] rotating shaft 135 of the motor 114 extends through the bore 124 of the first section 120 and engages a first timing belt pulley 131. The timing belt pulley 131 is secured to the shaft 135 and therefore rotates at the speed of the shaft 135. In operation, the motor shaft 135 drives the first timing belt pulley 131 in a clockwise direction. By way of example only, a motor suitable for the motor assembly 106 is manufactured by Mabuchi Motor, Model No. RS-775 or RS-500 series. The first timing belt pulley 131 drives the second timing belt pulley 132 by a timing belt 142 that frictionally engages both the first pulley 131 and the second pulley 132. Thus, the first pulley 131 and second pulley 132 rotate in the same direction.
The two [0038] pulleys 131 and 132 operate as a gear reduction mechanism so that the roller 116 will rotate at a slower speed than the motor shaft 135. For example, and as shown in FIG. 4, the diameter of the pulley 132 is larger than the diameter of the pulley 131. As previously mentioned, the pulley 131 rotates at the speed of the motor shaft 135. In a preferred embodiment, the diameter of the second pulley 132 is five to eight times larger than the diameter of the first pulley 131. Accordingly, the second pulley will rotate five to eight times more slowly than the first pulley 131.
The [0039] second pulley 132 has a shaft 133 that extends through the bore 130 and into the motor housing when the motor assembly 106 is assembled. The bore 130 is larger than the shaft 133 so that the pulley 132 may rotate freely. In one embodiment, the shaft 133 is maintained substantially parallel to the motor shaft 135. A bearing 150 is press fit into a bearing seat (not shown) located within the outer pulley 132 so that the bearing 150 and the pulley 132 rotate as a single object. A drive belt 143 connects first pulley 131 and second pulley 132.
In the embodiment shown in FIG. 4, the bearing is rotatably mounted onto a [0040] stem 152 extending from the protective cover 154. However, in alternate embodiments, the pulley 132 can mount directly onto the stem 152. In either case, the central axis of rotation of the pulley 132 is the stem 152. The protective cover 154 attaches to the first half 120 of the motor housing and remains separated from the outer surface of the motor housing so that it does not interfere with the operation of the pulleys 131 and 132 or the timing belt 142.
The [0041] roller 116 has a cavity to engage the shaft 133. As shown in FIG. 4, the shaft 133 has a cruciform shape. However, in alternate embodiments, other interlocking or keyed shapes can be used. The cavity of the roller 116 should be shaped similarly to the shaft 133 and have substantially the same diameter such that the roller 116 and the shaft rotate as a single unit and that the roller 116 does not slide in response to, or independent from, the shaft 133. Thus, the roller 116 will rotate at the same speed as the pulley 132.
In the embodiment shown in FIG. 4, the [0042] roller 116 preferably remains in a substantially horizontal position at all times. To help maintain this position in one embodiment, the roller 116 is supported at both ends. As previously mentioned, one end of the roller 116 is mounted on, and rotates about, the stem 152. An axle 142 extends from the other end of the roller 116. The axle 142 extends through, and is rotatably seated within, the bore 140 and a bearing 144 is seated within the bearing seat 141 of the axle 142. In one embodiment, the bearing 144 is press fitted into the bearing seat 141. The bearing engages a stem 148 that protrudes from the access cover 146. Similar to the bearing 150, the bearing 144 is rotatably secured to the stem 148 so that the roller 116 may rotate freely. Accordingly, the roller 116 is ultimately supported by the stems 148 and 152. The stems 148 and 152 are aligned along a concentric horizontal axis so that the roller 116 remains in a substantially perpendicular position in relation to the rear wheel 14 when the roller is in both the power-assist mode and the free-wheel mode (both described later).
In the power assist mode, the [0043] roller 116 frictionally contacts and drives the rear wheel 14 of the scooter. The continuous contact between the roller 116 and the rear wheel 14 will tend to wear the roller 116 down over time. The roller 116 is preferably manufactured from a material that will not easily degrade. The roller 116 may be manufactured from materials such as, but not limited to, steel or aluminum, to increase the life of the roller 116, or also rubber, plastic, a polymer or an elastomeric material which, preferably, is softer than the rear wheel. The roller 116 has a track or channel 117. In one embodiment, the track 117 is preferably shaped substantially similar to the contour of the rim of the wheel 14. For example, the track 117 is substantially “U”-shaped to mirror the shape of the wheel 14 shown in FIG. 1. Since the roller 116 will experience wear and tear from the frictional contact with the rear wheel 14, the roller 116 may need to be replaced from time to time.
As shown in FIG. 5, the [0044] motor assembly 106 is been designed so that the roller 116 can be easily replaced by the rider without having to remove the entire motor assembly 106 from the bracket 102. To replace the roller 116, the user can first place the scooter in the free-wheel mode (described hereinafter) by decoupling the roller 116 from the rear wheel 14. The cover 146 can then be removed to access the roller 116. In one embodiment, and as shown in FIG. 5, the cover 146 is secured to the motor assembly 106 by four screws. Once the cover 146 is removed, an individual can remove the worn-out roller by sliding the roller 116 off the pulley shaft 133 and out of the motor housing 106. A new roller 116 can then be placed into the motor assembly 106 and onto the shaft 133. After inserting a new roller, a user can replace the bearing 144 back into the bearing seat 141 and fasten the cover 146 to the motor assembly 106.
The scooter can be operated in a free-wheel mode and a power-assist mode. When the [0045] roller 116 is placed in the power-assist mode (see FIGS. 6B-6C), the track 117 of the roller 116 contacts the rear wheel 14 along its outer surface 15. The shape and size of the rear wheel 14 will vary depending on the manufacturer and model of the scooter. For example, some scooters, such as the Razor™ models, use smaller wheels having a diameter of approximately five inches. Other scooters, such as a few models designed by The Sharper Image™, use larger wheels having a diameter of nine inches. Thus, the shape and size of the roller 116 can vary to accommodate the specific shape of the rear wheel 14.
In one embodiment, there is a large contact area between the [0046] roller 116 and the rear wheel 14 to frictionally drive the rear wheel 14. The frictional force is proportional to the contact area shared between the two surfaces. The larger the frictional force created between the roller 116 and the rear wheel 14, the more efficiently the roller 116 will drive the rear wheel 14. A larger frictional force will also prevent the roller 116 from slipping while driving the rear wheel. However, it is noted that the final linear speed of the rear wheel is independent of the size of the rear wheel.
A rider should still have the option to manually push the scooter. For example, if the [0047] battery 156 expires while riding the scooter, it would be beneficial if the rider could manually push the scooter and not have to overcome the resistance created by the roller 116 remaining in contact with the rear wheel 14. The scooter can therefore operate in a free-wheel mode.
The [0048] torsional spring 118, mounted on the shaft 128, rotates to either hold the roller 116 against the rear wheel 14 (power-assist mode, FIGS. 6A-6C) or keep the roller 116 away from the rear wheel 14 (free-wheel mode, FIGS. 7A-7C). The shaft 128 is manually moved between the two positions by a lever (not shown) that is pivotally attached to and extending from the second half 122 of the motor housing 106. The lever is mechanically attached to the pivot shaft 128 and can be moved between a power-assist mode or free-wheel mode location. The lever can be “locked” into either position. Such engagement and locking mechanisms are well known in the art.
In the power-assist mode the [0049] roller 116 is held against the rear wheel 14 by the force from the torsional spring 118 FIGS. 6A-6C). FIG. 6B is a partial cross-sectional view of the motor assembly 106, along extension line C-C in FIG. 6A. As shown in FIG. 6B, the roller 116 is held against the rear wheel 114. In this position, the roller 116 will frictionally drive the rear wheel 14 when the throttle assembly 160 (to be described later) is activated. FIG. 6C illustrates a more detailed view of the roller 116 engaging the rear wheel 14, as shown in area D in FIG. 6B. The roller 116 is spring-biased in this position during the power-assist mode. By activating the throttle assembly 160, the roller 116 will rotate and drive the rear wheel 14, propelling the scooter forward.
If the user wishes to manually push the scooter, the user can select the free-wheel mode. The user can mechanically decouple the [0050] roller 116 from the rear wheel 14 by rotating the housing against 104 the torsional spring 118 away from the rear wheel 14. This action is accomplished by rotating the lever in the opposite direction that was required to place the scooter in the power-assist mode. By decoupling the roller 116 from the rear wheel 14, the rear wheel 14 may rotate freely about the rear axle 21. While the scooter is in the free wheel mode, the roller 116 is held away from, and is not in contact with, the rear wheel 14. FIGS. 7A-7C illustrate that the roller 116 is held away from the rear wheel 14 at all times during the free-wheel mode.
The [0051] retrofit kit 100 includes a throttle assembly 160 that electronically controls the rotation of the roller 116 (see FIG. 2). The throttle assembly 160 includes a cable 162 and an acceleration handle 164. The cable 162 is electrically connected between an acceleration handle 164 and the battery 156. In one embodiment, the cable 162 preferably travels down the connecting bar 22, across the side of the platform 10 and along the mounting bracket 102 to the battery 156. In one embodiment, the cable 162 is secured to the connecting bar 22, the platform 10 and the mounting bracket 102 to prevent the cable 162 from getting caught or snagged on a passing object. In an alternate embodiment, the cable 162 is secured to the side or bottom of the platform 10 so that the user will have a flat surface to stand upon.
In one embodiment, the acceleration handle [0052] 164 is mounted to the handlebar 26 so that the rider may conveniently control the speed of the scooter while standing on the platform 10. To activate the motor 135 and thus the roller 116, the acceleration handle 164 may be pulled towards the handlebar 26. When the handle 164 is pulled towards the handlebar 26, the roller 116 begins to rotate and drive the rear wheel 14. In one embodiment, the closer the acceleration handle 164 is pulled towards the handlebar 26 the faster the motor shaft 135 will rotate. Releasing the acceleration handle 164 to its “normal” position will electrically isolate to the motor 114 from the battery 156 and the motor will no longer drive the scooter. Such speed control is well known in the art. Positioning the acceleration handle 164 on the handlebar 26 allows a user to steer the scooter and control the speed of the scooter while maintaining both hands on the handlebar 26. The acceleration handle 164 may be fastened to either side of the handlebar 26. In alternate embodiments the acceleration handle 164 can be attached to other areas of the scooter or the acceleration handle 164 may be in the form of a foot peddle located on the platform 10 or any other convenient location of the scooter.
In most instances, the user may slow the speed of the scooter by releasing the [0053] acceleration handle 164. As previously mentioned, releasing the handle 164 causes the roller 116 to stop driving the scooter. In fact, the roller 116 will provide a small braking force. The rear wheel 14 must be able to overcome the frictional force of the motor shaft 135 and pulley system to keep rotating. However, sometimes this braking force will not be sufficient to bring the scooter to a complete stop. For example, if the rider is traveling down a steep hill the scooter may continue to accelerate even though the acceleration handle 164 has been released. Similarly, if the rider needs to bring the scooter to a quick stop, releasing the acceleration handle 164 may not stop the scooter in a sufficiently short period of time.
The [0054] foot brake 16 provides an additional method to stop or slow the scooter. Stepping on the foot brake 16 brings the underside of the foot brake 16 in contact with the rear wheel 14. This contact will slow the rotation of the rear wheel 14 and eventually bring it to a complete stop. In one embodiment, when the foot brake 16 is depressed, a motor cut-off switch interrupts the electrical signal to the motor 114 as previously mentioned, and electrically isolates the motor from the battery 156. The switch prohibits the motor shaft from driving the roller 116 while the foot brake 16 is depressed, even if the handle 164 is pulled towards the handlebar 26. This prevents the motor assembly 106 from driving the rear wheel 14 while the foot brake 16 is inhibiting rotation of the rear wheel 14. If the foot brake 16 did not include a cutoff switch, the motor shaft 135 could continue to attempt to rotate the roller 116 even though rotation of the rear wheel 14 is being inhibited by the foot brake 16. This could overheat and/or overload the motor 114, reducing the life of the motor or damaging it permanently. Furthermore, switch will be in an open position when the scooter is in a “free wheel” mode. Thus, electrical power will not be transmitted to the motor when the scooter is in “free wheel” mode (see also switch 804 in FIG. 9).
FIG. 8 is an alternate embodiment of the [0055] motor assembly 106. In the embodiment shown in FIG. 8, the motor assembly is inboard of the scooter rear wheel 14 rather than above or behind the rear wheel 14 of the scooter as described in the embodiment shown in FIGS. 2-7. In the embodiment shown in FIG. 8, the motor assembly 106 is rigidly fixed to the footboard 10 of the scooter, but does not interfere with the foot brake 16. In the embodiment shown in FIG. 8, the foot brake 16 also includes a pin 802 that extends from one side of the foot brake 16. When the foot brake 16 is in its inactive (non-depressed) position, the pin 802 is in contact with a switch lever 804 that is associated with the motor assembly 106 which closes the circuit and allows electrical power to be delivered to the motor assembly 106. When a user engages the foot brake 16 by depressing it, the pin 802 is moved out of contact with the switch lever 804 thus creating an open circuit and preventing delivery of electrical power to the motor assembly 106 and preventing the motor assembly 106 from driving the rear wheel 14.
FIG. 9 shows an elevation view of the [0056] motor assembly 106 attached to the scooter shown in FIG. 8. In the embodiment shown in FIG. 9, when the foot brake 16 is in an inactive position (non-depressed), it is held out of contact with the wheel 14 by a torsional spring 902. The torsional spring 902 is wound around a brake axle 904 and biased against both the foot brake 16 and at least one platform 906 on the rear fork 30. In alternate embodiments, the foot brake 16 may be supported by other mechanisms known in the art or the torsional spring 902 may be biased against other sections of the scooter.
As described with regards to FIG. 8, when [0057] foot brake 16 is in an inactive position (non-depressed), the pin 802 is held in contact with the switch lever 804. However, when the foot brake is depressed, the pin 802 is moved out of contact with the switch lever 804 and electrical power is not delivered to the motor assembly 106 to drive the wheel 14. It is noted that the foot brake 16 is located aft of the motor 106 for convenience of operation. The user can rest his rear foot on the motor and when desired conveniently shift his rear foot aft to activate the foot brake.
In the embodiment shown in FIG. 9, the [0058] motor assembly 106 is pivotally mounted on a rotation axle 908. The rotation axle 908 is connected to a support bracket 910 that is rigidly fixed to the scooter. In the embodiment shown in FIG. 9, the support bracket 910 is mounted to the scooter and primarily supported on the brake axle 904. To prevent rotation of the support bracket 910 and motor assembly 106 around the rotation axle 908, a front portion of the support bracket 910 rests against the upper surface of the foot board 10 and a rear portion 912 of the support bracket 910 rests on the upper side of the rear fork 30. In the embodiment shown in FIG. 9, the front and rear portions of the support bracket are biased by a torsional spring such that downward pressure is applied to both the rear fork 30 and the upper surface of the foot board 10. In alternate embodiments, the support bracket may be fixed to the scooter in various other manners.
In the embodiment shown in FIG. 9, the [0059] motor assembly 106 is biased by a torsional spring (not shown) such that the friction brushing (not shown) is pressed against the wheel 14. However, in alternate embodiments other methods know in the art to hold the roller (not shown) in contact with the wheel 14 may be used.
The [0060] motor assembly 106 further includes a toggle locking pin 914. The toggle locking pin 914 allows the motor assembly 106 to be moved from a first position to a second position and held in the second position. In a first position, the roller (not shown) is pressed against the wheel 14 such that rotation of the roller (not shown) can drive the wheel 14 and propel the scooter. In a second position, the roller (not shown) is held away from the wheel 14, thus allowing the scooter to be used without assistance from the motor assembly 106. In the embodiment shown in FIG. 9, when the motor assembly 106 is in a second position, the toggle pin 914 (FIGS. 11, 12) can engage a bore (not shown) in the mounting bracket such that the motor assembly is held in the second position. In one embodiment, the toggle pin 914 is spring biased such that when the toggle pin 914 is moved in a prescribed manner, the spring bias of the toggle pin 914 will drive it into the bore (not shown) in the mounting bracket when the motor assembly is in the second position. The toggle pin 914 may then be manually or automatically removed from the bore (not shown) so that the motor assembly may return to the first position.
FIG. 10 is a cross-sectional view of the [0061] motor assembly 106 and scooter shown in FIGS. 8 and 9. In the embodiment shown in FIG. 10, the motor assembly contains a roller 116 to frictionally drive the wheel 14 and a motor 114 to convert received electrical power into mechanical power to drive the roller 116. FIG. 10 also shows that the brake 16 further includes a brake pad 1002. In the embodiment shown in FIG. 10, the brake pad is removably attached to the brake 16 by two fasteners 1004. However, in alternate embodiments, the brake pad may not be present, or may be fixedly attached to the brake 16.
FIG. 11 is a perspective view of the interior of the [0062] motor assembly 116 shown in FIGS. 8-10. In the embodiment shown in FIG. 11 the motor 114 includes a drive wheel 1102 that is connected to the drive spindle 1104 of the motor 114. The drive wheel 1102 is affixed to the drive spindle 1104 such that it rotates with the same angular velocity as the drive spindle 1104 with little or no slippage. A drive belt 1106 connects the drive wheel 1102 to a roller driver 1108. The drive belt 1106 frictionally engages both the drive wheel 1102 and the roller driver 1108. The rotation of the roller driver 1108 rotates roller 116 about a roller axis 1110 which remains essentially stationary relative to the scooter. The roller 116 frictionally engages the wheel 14 to drive the scooter. The embodiment shown in FIG. 11 also includes a second roller 1112 which is removably attached to the roller axis 1110 and the roller 116. The second roller 1112 is a spare roller that may be interchangeably switched with the roller 116. In the embodiment shown in FIG. 11, an end cap 1114 that is removably attached to the roller axis 1110.
FIG. 11 further shows an embodiment which includes a [0063] bias spring 1116 that is associated with the toggle pin 914. The bias spring 1116 may be engaged such that the toggle pin 914 will be driven into a bore (not shown) in the mounting bracket 910 when the motor assembly 116 is in a second position, as described above with regards to FIG. 9.
FIG. 12 shows a perspective view of discrete components of one embodiment of the [0064] motor assembly 116. The embodiment shown in FIG. 12 includes a keyed spindle 1202 that mounts on the roller axis 1110 and is free to rotate about the roller axis 1110. The keyed spindle 1202 has a predetermined pattern that allows it to engage the bore within the roller 116 such that the keyed spindle 1202 can drive the roller 116. The keyed spindle 1202 is also designed to mate with a first driver cam 1204 and a second driver cam 1206. The opposite side of the first driver cam 1204 is keyed to mate with the roller driver 1108 and the opposite side the second driver cam 1206 is keyed to mate with and degage the bore of the second roller 1112. A locking cam 1208 is keyed to mate with the portion of the second driver cam that passes through the bore of the second roller 1112 and engage the end cap 1114. In the embodiment shown in FIG. 12, rotation of the roller driver 1108 causes rotation of the first driver cam 1204, the keyed spindle 1202, the roller 116, the second driver cam 1206, the second roller 1112, the locking cam 1208 and the end cap 1114 about the roller axis 1110.
In the embodiment shown in FIG. 12, the individual components may be easily removed by a user and replaced when worn or damaged. For example, if the [0065] roller 116 becomes worn, a user may wish to exchange the roller 116 with the second roller 1112. The user may simply remove the end cap 1114, locking cam 1208, second roller 1112 second driver cam 1206, roller 116, drive spindle 1202 and first driver cam 1204. The user may then disassemble the part and reassemble them with the roller 116 and second roller 1112 in the opposite locations then reinsert the assembly back along the roller axis 1110 and begin using the scooter again. Similarly, a user my replace any other worn or damaged piece associated with the drive spindle 1202.
Although FIG. 12 describes a configuration in which all components coaxial with the [0066] roller axis 1110 rotate when the roller driver 1108 is rotated, in alternate embodiments one or more components that are coaxial with the roller axis 1110 may remain rotationally stationary when the roller driver 1108 is rotated, provided that the roller 116 rotates in a predetermined relationship to the roller driver 1108. For example, in one embodiment, the second roller 1112 may remain rotationally stationary when the roller driver 1108 is rotated. Furthermore, in alternate embodiments, the second driver cam 1206 that engages the second roller 1112 may be rotationally isolated from the driver spindle 1202 by ball-bearing-type isolation between the side that engages the drive spindle 1202 and the side that engages the second roller 1112. Thus, rotation of the drive spindle 1202 would not force rotation of the second roller 1112, the locking cam 1208 or the end cap 1114.
In yet another alternate embodiment, the side of the [0067] second driver cam 1206 that engages the second roller 1112 may not be keyed in the area in which the second roller is engaged. Thus, rotation of the second driver cam 1206 would not force rotation of the second roller 1112.
To install the embodiment of the [0068] motor assembly 104 shown in FIGS. 8-11, a user can remove the brake axle 904 and the existing foot brake 16. The support bracket 910 together with the motor assembly 104 can then be positioned on the foot board 10 such that the rear portion 912 of the support bracket 910 rests on the rear fork 32 and the forward portion of the support bracket 910 rests on the rear end of the foot board 10. The pivotal supports of the new foot brake 16 can then be aligned with the new support bracket along the axis from which the brake axle 904 was removed. The brake axle 904 can then be re-inserted in its original location of the scooter to secure the new foot brake 16, support bracket 910, and motor assembly 104 to the scooter. The user can then tension the torsional spring against the new foot brake 16 such that the foot brake 16 is held out of contact with the rear wheel 14. The battery 156 and throttle control 164 can then be attached to the scooter in various locations and in various manners. The motor assembly 104, battery 156 and throttle control 164 can then be electrically connected as desired.
FIG. 13 is a perspective view of a [0069] battery 1302 that is being mounted on the connecting bar 22 of a scooter. In the embodiment shown in FIG. 13, the battery 1302 has a mounting slot 1304 and a bore 1306. The scooter has a mounting track 1308 that is removably attached to the connection bar 22 of the scooter by fasteners 1310 that frictionally retain the mounting track in position on the connection bar 22. In alternate embodiments, the mounting track 1308 may also be designed to mate with a particular section of the connection bar 22 in a “pocket fit” manner. In the embodiment shown in FIG. 13, the mounting track 1308 had a locking lever 1312 that extends from the side of the mounting track 1308. In one embodiment, the mounting track 1308 may include a set of contact plates that are designed to electrically connect the battery 1302 to the mounting track 1308 which is connected to both the motor assembly 106 and the throttle assembly 160 to deliver power to the motor assembly 106. In an alternate embodiment, the battery 1302 may be directly connected to the motor assembly 106 and the throttle assembly 160 and electrically isolated from the mounting track 1308.
FIG. 14 is a perspective view of the [0070] battery 1302 shown in FIG. 13 attached to the mounting track 1310. In the embodiment shown in FIG. 14, the locking lever extends through the bore 1306 in the battery 1302 to retain the battery 1302 in position relative to the mounting track 1310. Thus, in the embodiment shown in FIG. 14, to disengage the battery 1302 from the mounting track 1310, the locking lever 1312 must be depressed. In alternate embodiments, various other mechanisms know in the art may be used to secure the battery 1302 to the mounting bracket 1310.
With respect to each of the above two embodiments, the motor assembly and the battery are robustly, but removably secured to the scooter. [0071]
The foregoing description of embodiments of the present invention has been provided for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed. Obviously, many modifications and variations will be apparent to the practitioner skilled in the art. The embodiments were chosen and described in order to best explain the principles of the invention and its practical application, thereby enabling others skilled in the art to understand the invention for various embodiments and with various modifications that are suited to the particular use contemplated. It is intended that the scope of the invention be defined by the following claims and their equivalents. [0072]

Claims

1. A device that can electrically power a push scooter having a footboard mounted between a front wheel and a rear wheel, a steering handle operably associated with the front wheel, and a foot brake that can brake the rear wheel, comprising:

a motor assembly including a motor and a roller adapted to selectively frictionally engage and drive the rear wheel of the scooter;

said motor assembly movably mounted above and between the rear wheel and the foot board; and

with the foot brake located aft of the motor assembly.

2. The device as recited in claim 1, wherein said roller is selectably engaged with the rear wheel in a power-assist position and is selectably disengageable from the rear wheel in a free-wheel position.

3. The device of claim 2 including a lever for selectively locking the motor and the roller in one of the power-assist position and the free-wheel position.

4. The device as recited in claim 1, wherein said device further includes a cutoff switch that electrically isolates said motor from a battery when the foot brake is depressed, preventing said motor from driving said roller while the foot brake is depressed.

5. The device as recited in claim 4, wherein said cutoff switch is actuated by relative motion between the foot brake and the motor assembly.

6. The device of claim 1 wherein said motor assembly is adapted to be movable by use of the foot of a rider from a position where the roller engages the rear wheel to a position where the roller disengages the rear wheel.

7. A device that can electrically power a push scooter having a footboard mounted between a front wheel and a rear wheel, a steering handle operably associated with the front wheel, and a foot brake for braking the rear wheel, the foot brake pivotally mounted to said footboard by a foot brake mount, comprising:

a motor assembly including a motor and a roller adapted to selectively frictionally engage and drive the rear wheel of the scooter; and

said motor mounted by the foot brake mount to the scooter and forward of the foot brake.

8. The device as recited in claim 7, wherein said roller can be selectively placed into a rear wheel engaging power-assist position and a rear wheel disengaged free-wheel position.

9. The device as recited in claim 7, wherein said device further includes a cutoff switch that electrically isolates said motor from a battery when the foot brake is depressed, preventing said motor from driving said roller while the foot brake is depressed.

10. The device as recited in claim 9, wherein said cutoff switch is activated by relative motion between the foot brake and the motor assembly.

11. A device that can selectably electrically power a push scooter having a footboard mounted between a front wheel and a rear wheel, a steering handle operably associated with the front wheel, and a foot brake, comprising:

a battery;

a motor assembly including a motor and adapted to frictionally engage and drive the rear wheel of the scooter; and

a bracket mechanically connected to the scooter, that supports said motor assembly behind the rear wheel and that supports the battery above the motor assembly and behind the rear wheel.

12. The device as recited in claim 11, wherein said motor has a roller that can be placed in a power-assist position and a free-wheel position with regard to the rear wheel.

13. The device of claim 11 wherein said rear wheel is mounted to the footboard with a mounting frame and the bracket is adapted to mount onto said mounting frame.

14. An electrically powered vehicle, comprising:

a scooter having a footboard mounted between a front wheel and a rear wheel, a steering handle operably associated with said front wheel, and a foot brake that can selectively brake the rear wheel;

a motor assembly connected to said scooter for electrically powering said scooter, said motor assembly having a roller for selectively frictionally engaging and driving said rear wheel of said scooter;

a mounting bracket for pivotally mounting said motor to the scooter with the motor assembly located between and above said rear wheel and said footboard of said scooter and with the foot brake located aft of the motor assembly; and

a throttle assembly that can selectively control the speed of said roller, which throttle assembly is mounted on said steering handle.

15. The vehicle as recited in claim 14, wherein said vehicle further includes a cut-off switch that shuts off said motor when the foot brake is depressed.

16. An electrically powered vehicle, comprising:

a scooter having a footboard, a front wheel, a rear wheel operably associated with said footboard by a rear fork, a steering handle operably associated with said front wheel, and a foot brake that can selectively brake the rear wheel;

a device that can selectively electrically power said scooter, including:

a battery;

a motor assembly including a motor that is electrically connected to said battery and a roller for frictionally engaging and driving said rear wheel;

a mounting bracket mechanically connected to said rear fork for supporting said motor assembly behind the rear wheel and said battery above the motor assembly and above the rear wheel; and

a throttle assembly electrically connected to said battery and said motor and that can selectively control the speed of said roller, said throttle assembly mounted to said steering handle.

17. A method of retrofitting a push scooter with a propulsion system comprising the steps of:

removing a rear wheel axle from a rear fork of the push scooter;

attaching a mounting bracket on the rear fork of said scooter using the rear wheel axle;

having a motor assembly mounted on the mounting bracket such that a roller of said motor assembly can selectively frictionally engage a rear wheel that is mounted on the rear wheel axle; and

removably attaching a battery to one of said push scooter and mounting bracket.

18. A method of retrofitting a push scooter having a rear wheel and footboard with a propulsion system comprising the steps of:

removing a brake axle of the push scooter;

attaching a mounting bracket on the rear fork of said scooter using the brake axle;

having a motor assembly mounted on the mounting bracket such that a roller of said motor assembly can selectively frictionally engage the rear wheel of said push scooter; and

removably securing a battery to power the motor assembly.

19. A device that can electrically power a push scooter having a footboard mounted between a front wheel and a rear wheel, a steering handle operably associated with the front wheel, and a foot brake movably mounted to the scooter so that the foot brake can brake the rear wheel, comprising:

a motor assembly including a motor adapted to selectively frictionally engage and drive the rear wheel of the scooter; and

said motor assembly mounted between and above the rear wheel and the footboard with the foot brake located rearwardly of said motor assembly and above the rear wheel so that the foot brake can move relative to a position further rearwardly of said motor in order to brake rear wheel.

20. The device of claim 19 wherein:

said motor and said foot brake are mounted at about the same height above the scooter so that both are adapted to be actuated by the foot of a user.

21. The device of claim 19 wherein:

the motor assembly is movably mounted to the scooter, with the motor assembly having a first rear wheel engaging position and a second rear wheel disengaged position, and said motor assembly is located adjacent to the foot brake so that both are adapted to be actuated by the foot of a user.

22. A device that can electrically power a push scooter having a footboard mounted between a front wheel and a rear wheel, a steering handle operably associated with the front wheel, and a foot brake pivotally mounted to the scooter so that the foot brake can brake the rear wheel, comprising:

a motor assembly pivotally mounted to the footboard including a motor adapted to selectively frictionally engage and drive the rear wheel of the scooter, with the motor pivotable between a rear wheel engaging position and a rear wheel disengaged position; and

23. The device of claim 22 wherein:

24. A retrofit kit adapted to be fitted to a push scooter to electrically power the push scooter, where the push scooter has a footboard mounted between a front wheel and a rear wheel, a steering handle operably associated with the front wheel, and a foot brake movably mounted to the scooter so that the foot brake can brake the rear wheel, the retrofit kit comprising:

a battery;

a mount that enables said motor assembly to be mounted between and above the rear wheel and the footboard with the foot brake located rearwardly of said motor assembly and above the rear wheel so that the foot brake can move relative to a position further rearwardly of said motor in order to brake rear wheel.

25. A retrofit kit adapted to be fitted to a push scooter to electrically power the push scooter, where the push scooter has a footboard mounted between a front wheel and a rear wheel mounted to the footboard with a mounting fork, a steering handle operably associated with the front wheel, and a foot brake movably mounted to the scooter so that the foot brake can brake the rear wheel, the retrofit kit comprising:

a battery;

a mount that enables said motor assembly to be mounted onto the mounting fork and behind the rear wheel and with the battery located above the motor assembly and behind the foot brake.