Precision direct drive mechanism for a power assist apparatus for a bicycle

Abstract

A power assist apparatus which includes a battery pack that connects with a motor housing with the battery pack being removably mounted on the frame of the bicycle and the motor housing being mounting on a mounting plate which is carried by one of the support wheels of the bicycle. The power assist apparatus is designed to not only assist in the manual operation of the bicycle but also as a sole source of power for the bicycle. The mounting plate is to be affixed to the frame of the bicycle upon the desired location being selected for the mounting plate. The motor assembly operates a drive gear, pulley or sprocket which connects to a driven gear, pulley or sprocket which is mounted in conjunction with one of the support wheels of the bicycle. The motor housing may be disconnectable from the mounting plate as also the battery pack is capable of being disengaged from the frame of the bicycle permitting the bicycle to be used as a conventional bicycle without the power assist apparatus. The motor assembly is indexed to the axle of the support wheel maintaining accurate alignment in all operating conditions and upon repeated engagements and disengagements of the support wheel from the bicycle frame.

Description

BACKGROUND OF THE INVENTION1. Field of the InventionThis invention relates to an electrically operated, by means of a battery, power assist apparatus for a bicycle and more particularly, to a new and novel construction of that power assist apparatus for a bicycle.2. Description of the Prior ArtElectric powered bicycle have long been known. All electric powered bicycles incorporate an electric motor which is powered by a battery. One way the bicycle is powered is by a motor that operates through a drive wheel which frictionally engages with a support wheel of the bicycle. Movement of the drive wheel adds power to the manual movement of the bicycle or could be the only source of movement of the bicycle. Frictional engagement between the drive wheel and a support wheel is only one method. Others involve many configurations of direct drive involving shafts, chains, and gears but with the common feature of the driving motor being mounted on the bicycle frame in one position or another (e...

AI Technical Summary

Benefits of technology

The subject invention is a power assist apparatus for a bicycle which utilizes a direct drive mechanism between an electric motor and a drive gear, pulley or sprocket mounted on the hub of one of the wheels of the bicycle. It has been found to be most desirable to have the axis of the rotatable shaft of the motor parallel to the rotational shaft of a wheel for reasons of simplicity and smoothness of operation. A one-way clutching mechanism is to be mounted between the wheel and the motor. One or more batteries mounted within a battery pack are to be used to power the motor with this battery pack to be removably mounted on the frame of the bicycle. The motor is mounted within a motor housing with the motor housing being mounted within an enlarged hole formed within a mounting plate. The mounting plate is to be carried by a support wheel of the bicycle with either support wheel being satisfactory. This mounting plate is to be affixed by a bolt fastener (or pin) to the frame of the bicycle. This bolt or pin is to be easily removable. The mounting plate can be attached at any desired angular position on the support wheel but when selected is then fixed. The motor housing may be removably mounted on the mounting plate by a series of locking tabs being utilized to facilitate the engagement and disengagement of the motor housing to that mounting plate.

A further objective of this invention is to obtain a practical direct drive gear system employing precision indexing and alignment which is in a self-contained bicycle rear wheel assembly that features: (1) precision alignment with repeated removal and reengagement of rear wheel for repair; (2) maintaining precision alignment in all rough environments; and (3) has fast conversion of non-electric to electric configuration (<3 minutes) and back again with minimal weight penalty in normal operation.

Problems solved by technology

The prior art direct drive power assist devices for a bicycle have generally required complex gearing arrangements.

Upon removal of the wheel for maintenance, such as tire repair, precise reengagement is difficult leading to excessive wear and noise during operation.

Also, complex gearing arrangements are difficult to maintain in precise alignment when the bicycle encounters road bumps and holes.

Also, incorporation of prior art power assist apparatuses on bicycles has made it difficult to remove and replace the wheel(s) of the bicycle for tire repair and / or replacement.

Additionally, if it is desired to use the bicycle as a normal bicycle and have the bicycle not carry the extra weight of a battery pack plus a motor assembly, the prior art direct drive power assist apparatuses for bicycles have not been designed to be readily removable from the bicycle to permit normal manual usage without the extra weight involved.

These slight variations often result in excessive noise and wear.

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