Abstract:
A system for dual-attachment of a trailer to a vehicle by either manually or robotically so that the trailer becomes a laterally-stable extension of the vehicle.

Description:
BACKGROUND 
     Field 
     The present disclosure is disclosure is directed to improvements in trailers for vehicles. The disclosure is particularly applicable to wheeled trailers for carrying range extending systems for electric vehicles and will be described in connection with such utility, although other utilities are contemplated. 
     Background of the Present Disclosure 
     Today, the batteries present in electric vehicles have a relatively short range resulting in what is commonly referred to as “range anxiety.” 
     The art also has proposed range extending trailers carrying self-powered charging systems—commonly referred to as “range extenders”—for the batteries of for electric vehicles. However, trailers are inherently maneuverably unstable. Pulling a trailer requires maintaining a smooth pulling geometry between the two vehicles. Any quick changes in speed or direction can cause undesirable reactions in an attached trailer, resulting in sliding and/or jackknifing, particularly on slippery roads, or driving under windy highway conditions. Additionally, backing up maneuvers, and, aligning and hitching a trailer can be difficult particularly for drivers who only occasionally have a need to trailer, requiring the driver to align the trailer ball and hitch behind the vehicle, below the driver&#39;s line of sight. Accordingly, current range extending trailers contain complicated back-up steering mechanisms. 
     SUMMARY OF THE DISCLOSURE 
     The present disclosure overcomes the aforesaid and other disadvantages of the prior art, by providing an attachable wheeled trailer that includes an attaching plate that self-aligns to a receiving plate on the vehicle. The trailer has a minimum of three wheels. In use, the trailer is suspended on one or a pair of swiveling wheels. However, the trailer also has a pair of swiveling wheel or wheels normally deployed out of the way when the trailer is hitched to the vehicle. The additional swiveling wheel or wheels support the trailer when the trailer is detached from the vehicle, making the trailer readily maneuverable on the ground. 
     More particularly, the present disclosure provides a trailer comprising a housing, one or more swiveling suspension wheels, one or more swiveling ground maneuvering wheels, and an attaching plate for engaging with a receiving plate on a vehicle. 
     In one embodiment, the trailer includes a maneuvering handle, which may be rear mounted or side mounted. 
     In another embodiment, the attaching plate is sized and shaped to self align in the vehicle receiving plate. 
     In one embodiment, the trailer comprises two suspension wheels and one ground maneuvering wheel. 
     In another embodiment, the trailer comprises one suspension wheel and two ground maneuvering wheels. 
     In still yet another embodiment, the trailer comprises two suspension wheels and two ground maneuvering wheels. 
     In a preferred embodiment of the disclosure, the trailer comprises a range extending trailer for a battery powered vehicle. 
     In yet another embodiment, the disclosure provides a trailer having one or more swiveling or non-swiveling suspension wheels, and a pair of hitching tongues with connectors for engaging with a pair of ball hitch connectors on a vehicle. In such embodiment, the trailer optionally may include maneuvering handles on the trailer or on the tongues of the trailer. The trailer may comprise one suspension wheel and two ground maneuvering wheels, two suspension wheels and one ground maneuvering wheel, or two suspension wheels and two ground maneuvering wheels. 
     In yet another embodiment, the trailer includes, a housing, one or more wheels, and a pair of hitching tongues with ball connectors. 
     In one embodiment of the disclosure, the range extender attaching plate is able to slideably adjust into position on the vehicle&#39;s receiving plate by omni-directional movement of the trailer. 
     The present disclosure also provides a system for extending the range of a motor vehicle powered by an electric motor, said system comprising a trailer as above described, and one or more rechargeable batteries carried in the trailer, or a self-powered charging system for the batteries of the electric vehicle. In such embodiment, the motor vehicle may be an automobile, a truck, a van or a bus. 
     In yet another embodiment there is provided a battery pack configured to power a motor vehicle carried on a trailer as above described. 
     In still yet another embodiment, the disclosure provides a trailer hitch assembly for connecting a trailer to a vehicle, comprising a two ball hitch structure for mounting on a vehicle, and for engaging with two hitching tongues mounted on a trailer. 
     Finally, the disclosure provides an attaching plate for a trailer compatible with attachment requirements of a vehicle plate dually attached to the trailer. In such embodiment, the structure may include a single receiving plate installed on a vehicle. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       Further features and advantages of the present disclosure shall be seen from the following detailed description, taken in conjunction with the accompanying drawings, wherein like numerals depict like parts, and wherein: 
         FIGS. 1A and 1B  illustrate maneuvering functionality of a three-wheeled range-extending trailer according to the present disclosure. 
         FIGS. 2A and 2B  demonstrate the manual maneuverability of the range-extending trailer vehicle by means of two different handle configurations. 
         FIGS. 3A-3C  demonstrate an alternative swing-away installation system allowing full access to the rear of an attached vehicle. 
         FIGS. 4A-4D  demonstrate a manual attachment of the range-extending trailer to a vehicle. 
         FIG. 5A  demonstrates the functionality of a range-extending trailer attaching plate installing to a vehicle receiving plate, and  FIG. 5B  is a top plan view thereof. 
         FIGS. 6A-6G  demonstrates the lateral and vertical self-aligning functionality of a range-extending trailer attaching plate installing to a vehicle receiving plate. 
         FIGS. 7A and 7B  illustrate two alternative embodiments of a range-extending trailer of the present disclosure. 
         FIGS. 8A-8D and 9A-9B  illustrate yet another alternative embodiment of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1A  is a plan view of a range-extending trailer  100  showing the maneuvering functionality of the vehicle swiveling suspension wheel or wheels  130  and trailer swiveling ground maneuvering wheel or wheels  140 . Also shown is dually-attached trailer installing plate  150 . 
       FIG. 1B  illustrates how the swiveling wheels  130 ,  140  permit lateral maneuverability of the range-extending trailer. 
       FIG. 2A  demonstrates manual maneuvering of the range-extending trailer from behind using a rear handle  160 . 
       FIG. 2B  demonstrates manual maneuvering of the range-extending trailer from a side using a side-front wrapping handle  170 . 
       FIG. 3A  is an elevational view of an electric pickup truck  200  that requires full access to its rear end. The same would be true for station wagons and SUVs and delivery vans. Identified are the trailer&#39;s housing  110  and deployable rear handle  115 . 
     In an expanded view,  FIG. 3B , is shown the range-extending trailer&#39;s attaching plate  150  and the vehicle&#39;s receiving plate  210  installed to vehicle hinged hitch frame  250 . The hinged frame  250  features a quick release component (not shown) allowing its two hinged components to be operationally opened. 
       FIG. 3C  is a plan view of the truck with its hinged attachment frame opened so as to locate the attached range-extending trailer off to a side so as to allow full access to the back of the vehicle. 
       FIGS. 4A-4D  demonstrate manual attachment of a range-extending trailer  100  to electric vehicle  200 . 
       FIG. 4A  shows the range-extending trailer  100  sitting on the ground supported on its own three wheels  130 ,  140 . Identified are a swiveling suspension wheel  130 , a swiveling ground maneuvering wheel  140 , the vehicle&#39;s housing  110 , deployable rear handle  115  and attaching plate  150 . 
       FIG. 4B  demonstrates a man raising the front of the range-extending trailer&#39;s installing plate above the operational height of a vehicle&#39;s receiving plate  215 . This action also has elevated maneuvering wheels  140  off the ground. 
       FIG. 4C  shows the tilted range-extender trailer&#39;s attaching plate arriving over the vehicle&#39;s receiving plate. 
       FIG. 4D  demonstrates the installing plate having been lowered onto vehicle receiving plate  210 . 
       FIG. 5A  is an operational schematic of the connecting plates. Range-extender trailer installing plate  150  is positioned at step  202  and moved at step  204  to above its target receiving plate  210  and lowered at step  206  into connection with the receiving plate. Step  208  shows the accomplished connective assembly of the plates. At step  208  a locking pin  220  is installed into aligning holes  222  in the established plates. 
       FIG. 5B  is a top plan view of the dual-connectivity structure of a range-extending trailer&#39;s installing plate  150  arriving to an electric vehicle&#39;s receiving plate  210 . 
       FIGS. 6A-6F  present front and side views and  FIG. 6G  a top plan view of self-aligning functionality installing plate  150  slidingly installed to vehicle receiving plate  210 , as follows: 
       FIG. 6A  is illustrates the receiving plate&#39;s alignment edges  230  that will guide the installing plate down into the seating recess,  235 . 
       FIG. 6B  illustrates an installing plate making random first contact with the receiving plate  210 . 
       FIG. 6C  illustrates the installing plate being laterally slid against the receiving plate until an end edge  290  is above an alignment edge of the receiving plate. 
       FIG. 6D  illustrates the installing plate&#39;s indicated guiding edge being slid down an alignment edge of a receiving plate. 
       FIG. 6E  illustrates the installing plate free of the bottom of the alignment plate edge and so over the receiving plate&#39;s seating recess  235 . 
       FIG. 6F  illustrates the installing plate being lowered down into operational connection with the receiving plate. 
       FIG. 6G  is a top plan view of the accomplished connective assembly of trailer installing plate  150  and a vehicle receiving plate  210 . 
     By virtue of the disclosure that has just been described it is a simple and straight forward exercise for a user to attach a swiveling-wheeled range-extending trailer to an electric vehicle, thus significantly extending the range of the vehicle. Moreover, unlike conventional single ball-mounted trailers, being dually-attached to the vehicle, and by virtue of the swiveling ground maneuvering wheel or wheels, the trailer will effortlessly track movement with the vehicle when backing up as a laterally-stable extension of the vehicle. 
     The disclosure in particular allows users of electric vehicles to simply and rapidly attach a range-extending trailer to an electric vehicle. The range-extending trailers may be privately owned, i.e. by the vehicle owner, or alternatively can be rented from central depots when a long trip is planned. Also, since the range-extending trailers may be provided with a universal standard attaching plate, and electric vehicles with a universal receiving plate, it will be a simple matter to attach or swap out a range-extending trailer at a central depot in a matter of minutes. The attachment system allows both manual and robotic attachment of the trailer to a suitably equipped vehicle. 
     Various changes may be made in the above disclosure without departing from the spirit and scope thereof. 
       FIGS. 7A and 7B  illustrate two alternative embodiments. In  FIG. 7A , the range-extending trailer has two swiveling suspension wheels  130 A,  130 B, and a single swiveling ground maneuvering wheel  140 . In  FIG. 7B , the trailer has two swiveling suspension wheels  130 A,  130 B and two swiveling ground maneuvering wheels  140 A,  140 B. 
       FIGS. 8 and 9  present a laterally-stable dual-hitching structure as an elaboration of the existing normal single-ball hitching method for trailers to vehicles. 
       FIG. 8  is a top plan view demonstrating a dual-ball hitching procedure. 
       FIG. 8A  presents vehicle hitch frame  410  that features two hitch balls  415 , and trailer hitch frame  310  that features two trailer hand grabs  315 . Extending from the hitch frame are two hitching tongues with coupler connectors  320 . The tongues are in assembly with tongue connective support  330 . An arrow demonstrates the initial operational destination of a trailer hitching connector to a hitch ball of the vehicle  400  hitch frame. 
       FIG. 8B  illustrates a first step of the trailer hitching process: a person&#39;s hand grabbing a trailer hand grip  325  and pulling a trailer tongue into installed connection with a vehicle hitch ball. 
       FIG. 8C  illustrates a second step of the hitching process from the other side of the trailer  300 : a hand is shown pulling the second trailer tongue toward it&#39;s destination vehicle hitch ball. 
       FIG. 8D  presents the accomplished dual-hitched trailer attachment. 
       FIG. 9A -is a full side view of detail  81 / FIG. 9B  is a full top plan view of detail  8 D. 
     While the disclosure has been provided in connection with wheeled range-extending trailers for electric vehicles, the disclosure advantageously may be used in connection with other general-purpose or special-purpose trailers. 
     DRAWINGS—Reference Numerals 
     
         
           100  Range-Extending Trailer 
           110  Trailer Housing 
           115  Handle 
           130  Trailer Swiveling Suspension Wheel 
           140  Trailer Swiveling Ground Maneuvering Wheel 
           150  Trailer Installing Plate 
           160  Rear Handle 
           170  Side Handles 
           200  Electric Vehicle 
           210  Vehicle Receiving Plate 
           215  Clearance Height of Receiving Plate 
           220  Locking Pin 
           222  Locking Pin Holes 
           230  Receiving Plate Alignment Edge 
           235  Receiving Plate Seating Recess 
           240  Installing Plate End Edge 
           250  Vehicle Hinged Hitch Frame 
           300  Trailer 
           310  Trailer Hitch Frame 
           315  Trailer Hand Grip 
           320  Trailer Hitching Tongue with Ball Connector 
           325  Tongue Hand Grip 
           330  Tongues Connective Support 
           400  Electric Vehicle 
           410  Trailer Hitch Frame 
           415  Hitch Ball 
           202 - 208  Alignment and Attachment Steps