Battery Carrier for Electric Assisted Vehicle

This invention relates to an electric motor assisted vehicle and more particularly to an improved battery carrier therefor.

There have been proposed a class of vehicle wherein the vehicle is powered primarily by a manual input force of the operator. However, there is also incorporated an electric motor assist which provides assist power for assisting the operator's manual propulsion of the associated vehicle. Although the type of vehicle employed for this purpose may be of a wide variety, this type of system is frequently used on land vehicles such as bicycles that have a generally open construction.

Specifically, the type of system generally employs a manual force receiving device such as a pedal operated crank mechanism that drives a transmission for driving an output shaft for propelling the vehicle. An electric motor is employed in conjunction with this pedal operated mechanism for providing electric power assist for driving the vehicle. Generally, at least one sensor is also incorporated in this mechanism that senses the input force of the operator to the pedal operated mechanism. This sensed signal is then sent to a controller which, in turn, controls the transmission of electrical power from a battery to the electric motor for determining the amount of electric power assist.

This type of vehicle derives the electrical power for operating the electric motor from a rechargeable type battery. Conventionally, the type of battery utilized is comprised of a battery pack that consists of a number of individual rechargeable cells that arc wired in series with each other. For convenience, these cells are generally contained within an outer container that has terminals that afford the connection to the electric motor and controls for it.

Frequently, it is desirable to ensure that the battery itself may be removed from the vehicle and taken to a remote location for charging. To achieve this, it has been proposed to put the battery pack into an outer housing or battery carrier. This battery carrier is then, in turn, mounted in a battery case that is fixed in some way to the vehicle so that, upon insertion, it will be electrically connected to the electric motor and its control. Of course, it should be easy to insert and remove the battery carrier for charging and replacement.

The problem of accomplishing this result is particularly acute with a vehicle such as a bicycle. Bicycles have a very compact and open construction. It has been proposed, therefore, to mount a battery case on one of the frame tubes of the bicycle and to insert and remove the battery carrier (battery pack and its outer casingO from this battery case. Obviously, this presents a large degree of bulk. In addition, it also makes it cumbersome to insert and remove, and somewhat interferes with the configuration of the bicycle per se.

It is, therefore, a principal object of this invention to provide an improved battery case assembly for an electrically assisted vehicle.

It is a further object of this invention to provide a compact battery carrier and battery case for an electric power assisted vehicle, such as a bicycle or the like.

This invention is adapted to be embodied in a detachable battery case assembly for an electrically powered vehicle. The battery case assembly comprises a generally cup-shaped base part that is adapted to receive one end of an elongated battery carrier and which is fixed to the vehicle in an accessible position. A guide extends upwardly from one side of the base portion. The battery carrier and the guide have inter-engaging portions for directing the movement of the battery carrier into the cup-shaped base portion upon insertion into the base portion.

FIG. 1 is a side elevational view of a bicycle constructed in accordance with a preferred embodiment of the invention.

FIG. 2 is in enlarged cross-sectional view taken along the line 2--2 of FIG. 1 with the battery carrier and battery case being shown in solid lines as well as their attachment to the frame with the remaining components shown in phantom.

FIG. 3 is an enlarged side clevational view of a portion of the bicycle shown in FIG. 1 and illustrates the components shown primarily in FIG. 2 but illustrating the bicycle in solid line view and the seat in its normal, riding position.

FIG. 4 is a partial side elevational view, in part similar to FIG. 3 but shows the position of the seat and position of the battery carrier upon installation and removal.

FIG. 5 is a rear elevational view of the battery case looking generally in the direction of the arrow 5 in FIG. 3.

FIG. 6 is an enlarged cross-sectional view taken along the line 6--6 of FIG. 3.

FIG. 7 is a top plan view showing the base of the battery case.

FIG. 8 is a view of the battery guide portion of the battery case in elevational view but being rotated 90.degree. from the position shown in FIG. 5.

FIG. 9 is a cross-sectional view of the guide taken along the line 9--9 of FIG. 8.

FIG. 10 is an enlarged cross-sectional view of the battery lock showing the key in phantom.

FIG. 11 is a side elevational view of the battery lock looking in the same general direction as FIG. 10 but shows the key in solid lines.

FIGS. 12-16 are cross-sectional views of the lock, in part similar to FIG. 12 but on a smaller scale, and show the cooperation with the battery carrier in various conditions.

FIG. 12 shows the locked position.

FIG. 13 shows the insertion of the key prior to release of the lock and rotation thereof to the unlocked position.

FIG. 14 shows the lock released and the battery carrier released and partially removed.

FIG. 15 shows the condition after the battery has been removed and the key has been removed from the lock.

FIG. 16 shows the reinsertion of the battery in place to illustrate how the automatic locking occurs.

A bicycle constructed in accordance with a first embodiment of the invention is illustrated primarily in FIG. 1. The bicycle is indicated generally by the reference numeral 21 and includes a frame assembly, indicated generally by the reference numeral 22. The frame assembly 22 includes a head pipe 23, a down tube 24, and a seat tube 25. The down tube 24 and seat tube 25 are connected to each other and to a bracket assembly, indicated generally by the reference numeral 26 and which includes the drive unit, indicated generally by the reference numeral 27 which may be of the type shown and described in detail in the co-pending application entitled "SENSOR FOR ELECTRIC MOTOR ASSISTED VEHICLE", Ser. No. 08/887,489 Filed Jul. 2, 1997 (Attorney Docket No.YAMAH4.274A) now U.S. Pat. No. 5,915,493, issue Jun. 29, 1999, and assigned to the assignee hereof

A pair of chain stays 28 extend rearwardly from and are connected to the bracket 26. The chain stays 28, in turn, carry a rear wheel bracket 29 on which a rear wheel 31 is rotatably journaled in a known manner. A pair of seat stays 32 extend downwardly from the upper end of the seat tube 25 so as to provide triangular reinforcement for the assembly. The upper and forward ends of the seat stays are connected to the upper end of the seat tube 25 by a clamp 33.

A front fork 34 is journaled by the head tube 23 and rotatably journals a front wheel 35. The front fork 33 is dirigibly supported in the head pipe 23 and carries a handlebar assembly 36 at its upper end for steering of the bicycle 21 in a well-known manner. The rear and front wheels 31 and 35 are partially covered by respective fenders 37 and 38.

A seat post 39 (FIGS. 3 and 4) is slidably supported in the seat tube 25 and pivotally carries a seat 41 on which a seated rider may operate the bicycle 21. The seat 41 is pivotally carried by the seat post 39 for a reason which will be described. However, this mechanism will be described now by reference to FIGS. 3 and 4. FIG. 3 shows the seat in its normal riding position while FIG. 4 shows it pivoted upwardly for access and service purposes.

A bracket assembly 42 is affixed to the upper end of the seat post 39 in any suitable manner. This bracket has a pair of side portions 43 that receive a pivot pin 44 to establish a pivotal connection to the seat 41.

A latch mechanism, indicated generally by the reference numeral 45 is provided for detachably latching the seat 41 in its normal operative riding position. This latch mechanism 45 includes a keeper pin 46 that spans the legs 43 of the bracket 42. A pivotally supported latch element 47 has a retainer portion 48 that normally is held in engagement with the keeper pin 46 when the seat 41 is in its normal, riding position. The latch member 47 is pivotally supported on a base clement 49 of the seat by means of a pivot pin 51. A coil compression spring 52 holds the latch 45 in this engaged position.

However, by pivoting the lever 47 in an upward or clockwise direction, the portion 48 moves free of the pin 46 and the scat 41 can be tilted upwardly. Upon return of the seat 41 to its normal riding position, the latch mechanism 45 will again engage.

Referring again primarily to FIG. 1, the drive unit 27 is comprised of an outer housing assembly, indicated generally by the reference numeral 53 that journals a crankshaft 54 for rotation about a transversely extending axis. The crankshaft 54 has affixed to its exposed ends a pair of crank arms 55 each of which journals a pedal 56 at its outer extremity. Thus, the pedals 56 may be conveniently operated by a rider seated on the seat 41.

The crankshaft 54 is connected through a step-up transmission to drive a drive sprocket (not shown) which, in turn, drives a chain 57. The chain 57 is entrained around a driven sprocket 58 that is affixed for rotation with an and which drives the rear wheel 31.

In addition, an electric motor 59 forms a part of the propulsion unit 27 and offers electric power assist to assist the manual force applied to the pedals 56. The electric motor 59 drives the aforenoted and not shown sprocket through a step down transmnission.

A controller 61 receives input data such as the force applied by the rider to the pedals 56 and the speed of rotation or travel so as to control the power assist provided by the motor 59. This structure may be of any type known in the art and reference may be had to either the aforenoted copending application or U.S. Pat. No. 5,570,752, issued Nov. 5, 1996, for the constructions and control strategies that may be utilized to practice the invention.

A rear wheel lock 62 may be carried by the seat stay 32 for locking the rear wheel 31 when the bicycle is not in use, for example when supported on a kick stand 63. If desired, a cover assembly 63 may be carried by the frame 22 to afford cover and protection for the mounting bracket 26 and a portion of the propulsion unit 27.

As may be seen in FIG. 1, a battery box, indicated generally at 64, is positioned to the rear end of the seat pipe 25 and between the scat stays 32. This permits a rechargeable battery carrier 65 to be inserted or removed from the battery box 64 in a vertical direction when the seat 41 is pivoted to the position shown in FIG. 4.. The battery box 64 has a base portion 66 which, as will be described, affords the electrical connection between the battery carrier 65 and the drive unit 27. This interrelationship will be described shortly.

The battery box 64 and its connection with the battery carrier 65 will be described now in detail by reference primarily to FIGS. 2-9. This mechanism includes a battery lock, indicated generally by the reference numeral 67 which will be described later in more detailed reference to FIGS. 11-16.

As has been noted, the battery box 64 has a base portion which is indicated generally by the reference numeral 66 and which has a generally cup shape. This base 66 is affixed to the upper side of the mounting bracket 26 by threaded fasteners 68. The base 66 forms a generally upwardly extending opening that extends, in position, parallel to the scat tube 25 and immediately to the rear of it. The seat post 25 is moved forwardly from the rear fender 37 so as to provide adequate area for the battery 65 and maintain a good center of balance for the bicycle 21.

The base portion 66 is formed with a receptacle-type opening, indicated by the reference numeral 69 and shown best in FIG. 7. This opening 67 receives a guide member, indicated generally by the reference numeral 71. The guide member 71 is formed from a soft plastic material such as a polypropylene and has a bayonet-type base portion 72 that is detachably received in the opening 67 when pressed thereinto.

This guide member 71 extends vertically upwardly forwardly of the back fender 37 and has a curved bearing part 73 which is configured so as to engage the battery case 65 when inserted in place and to bias it generally in a forward direction. The side parts, indicated by the reference numeral 74 of the guide portion 71 are configured for a purpose which will be described. There is further provided a curved guide in end 75 at the upper extremity of the guide member 71.

The battery 65 and specifically the battery carrier is comprised of a two piece outer case, indicated generally by the reference numeral 76, and which contains a plurality of rechargeable battery cells such ni-cad cells that are packaged in a shrink type container for protection in addition to that provided by the battery case 76.

As best seen in FIG. 2, the battery case 65 rear surface has a cross-section that defines a pair of recesses 77 which are complimentary to and which receive the end portions 74 of the guide member 71. Thus, this tongue and groove interaction will guide battery case 76 and contain batteries when inserted into mating relationship with the base 66.

In addition, a snubber 78 is carried at the rear of the seat post 25 on a metallic backing plate 79. The corresponding part of the battery case 76 has a pair of inwardly extending cabs 81 which engage the sides of the snubber 76 and will guide it also at the forward end. The biasing of the portion 73 of the guide 71 will hold the battery case 76 forwardly in this assembled relationship against the snubber 78 so as to resist rattling and motion.

As may be best seen in FIG. 3, the base portions 66 of the battery box 64 is provided with a pair of terminals 82 that mate with corresponding terminals carried at the lower end of the battery case 76 and in contact with the cells thereof so as to permit electrical connection when the battery carrier 65 is positioned in the battery case 64 and specifically the base portion 66 thereof.

The battery carrier 65 is also provided with a carrying handle 83 at the upper end thereof that carries a terminal 84 for charging of the battery either in location or when moved to a remote location.

Since the battery carrier 65 itself forms the major outer portion of the covering for the batteries when in place, the structure is much smaller and more compact than prior art type of construction. Furthermore, the insertion and removal is facilitated by the described construction and this makes the device very easy to manipulate and utilize by riders.

The upper end of the guide member 71 is also provided with an opening 84 that may receive a further fastener 85 and 86 so as to bolt it to the rear fender 37 so as to offer further stability to the assemblage.

The function and operation of the lock assembly 67 will now be described by reference to FIGS. 10-16. Basically, the lock assembly 67 functions to detachably retain the battery carrier 65 in the battery box 64. Upon its release, the battery carrier 65 may be removed. However, the key, indicated by the reference numeral 87 that is utilized with the lock 67 cannot be removed until the lock 67 is reset in its automatic locking position. In this way, the operator need only unlock the lock 67 to remove the battery carrier 65 and when the battery carrier 65 is reinserted, it will be automatically locked in position.

The lock 67 includes an outer housing 88 that has a cylindrical portion which terminates at one end in a larger diameter cylindrical flange 89. This flange 89 is formed with tapped openings 91 that receive threaded fasteners tor detachably affixing it to the bracket assembly 66. These fasteners are concealed within the bracket assembly 66 and hence, the lock 67 cannot be easily disassembled from the bicycle 21.

The flange portion 89 has a small cylindrical projection 92 that passes through an opening in the bracket 66 and which defines a cylindrical bore 93. A keeper 94 is slidably supported within this opening 93 and has an inclined wedge locking surface 95. As may be best seen in FIGS. 12 and 13, the lower portion 96 of the battery carrier 65 is formed with a complimentary receiving notch 97 for the keeper 94. When in the position shown in FIG. 12, the battery carrier 65 is locked in the battery case 64 and specifically at base portions 66.

The lock mechanism 67 includes a sliding cylinder 98 that is received within a larger bore 99 formed in the housing member 88. A coil compression spring 101 acts between the sliding plunger 98 and the housing 88 for normally urging plunger 98 to the position shown in FIGS. 10 and 11 which is the released position.

The keeper 94 further is formed with a bore 102 in which a smaller plunger 103 reciprocates. A coil compression spring 104, which is lighter than the spring 101 acts on the plunger 103 to normally urge it into engagement with a recess 105 formed in an end plate 106 of the cylinder 98.

Also contained within the cylinder 98 is a tumbler mechanism 107 that acts to lock the cylinder 98 in either the unlocked position as shown in FIGS. 10, 11 and 14 or in its locked position as shown in FIGS. 12, 13, 15 and 16.

The cylinder 98 is formed with an open slot 108 into which a tab 109 (FIG. 11) of the end plate 106 extends. This tab 109 extends through the opening 108 in the cylinder 98 and into an L-shape opening having a short wide leg 111 and a long narrow leg 112 is formed. The plate 106 is coupled with the tumbler of the locking mechanism 107 and thus, rotates with the key 87. The purpose of this mechanism including the tab 109 and slot comprising the portions 111 and 112 is such that it will ensure that the key must be placed in a locked condition before it can be removed from the tumbler 107.

Hence, FIGS. 10 and 11 show the mechanism in its released position wherein the battery may be removed. However, in this position the key 87 cannot be removed from the tumbler 107. In order to accomplish this, the key 87 and tumbler 107 and cylinder 98 must be moved to the right as shown in FIG. 11 so that the tab 109 traverses the slot 111 and comes into registry with the slot 112. At this time, the key 87 can be rotated in a clockwise direction viewed from the left and the key may then be removed. FIG. 12 shows the condition when this locking has occurred.

Thus, if it is desired to remove the battery carrier 65 for charging of the batteries, the key 87 must be inserted into the tumbler 107 and the key rotated in a counter clockwise direction as shown by the arrow in FIG. 13.

This rotation continues until the tab 109 moves along the slot portion 112 and registers with the slot portion 111. When this occurs, the action of the spring 101 will be sufficient to urge both the locking member 94 to the left so as to clear the notch 97 in the battery carrier 96 and permit its removal. This will cause the tab 109 to traverse the slot portion 111. At the same time, the action of the spring 104 on the plunger 103 will cause the cylinder 98 and tumbler 107 also to move in this direction supplementing the action of the spring 101. Hence, the mechanism will then be in the final released position as shown in FIG. 14 and the battery carrier 96 can be removed for recharging of the battery.

However, the key 87 cannot be removed. Thus, in order to remove the key 87 the operator must again trigger the locking mechanism 67 to its locked position. This is done by moving the tumbler 107 and cylindrical plunger 98 to the right and to the position shown in FIG. 15. Then, the key is rotated and the tab 109 moves into the slot portion 112 so as to retain the plunger 98, tumbler 107 and locking member 94 in the locked position as shown in FIG. 15. The key then can be removed as indicated by its absence from FIG. 15.

When the batteries have been charged and the battery carrier 65 is reinstalled, a curved lower end 113 of the battery carrier will engage the inclined surface 95 of the locking member 94 and urge it to the left as shown in FIG. 16. This movement is accomplished by compressing the relatively light spring 104. Once the battery carrier 65 is fully inserted to the position shown in FIG. 12, the lock 67 will reengage.

Thus, it should be readily apparent from the foregoing description that the described mechanism provides very simple yet high effective battery box and carrier arrangement for the batteries of an electrically assisted vehicle and particularly a small open vehicle such as bicycle. Thus, the space considerations are relatively minor and it is not necessary to reconfigure the bicycle to any substantial extend to accommodate the batteries.

Of course, the foregoing description are those of a preferred embodiment of the invention and various changes and modifications may be made without departing from the spirit and scope of the invention as defined by the appended claims.