Abstract:
A battery powered, electric motorized cart and burden carrier which may be manually pushed or pulled to a shopping area for use during shopping and for transporting merchandise thereafter. Battery powered motors and gearing associated with the rear driving wheels are controlled from a control box on a lanyard attached to the cart so that the loaded cart may be either operated and controlled by an individual walking in front or the rear thereof. Steering is effected through the swivelly mounted front wheels by the operating exerting a tug on the lanyard or applying forward pressure to the rear of the cart when the control box is arranged and supported thereat. Battery charging may be accomplished by actuating a control box switch to close the circuit to the battery and manually pushing the cart to rotate the motor shafts and cycle the amperage back into the battery. Another way is to utilize an alternating current charging adapter.

Description:
BRIEF SUMMARY OF THE INVENTION 
       [0001]    This invention relates to an electric motor and battery powered wheeled shopping cart and burden carrier manually pushable or pullable to a shopping area for use during shopping and for thereafter transporting merchandise under motor power by the operator walking along therewith and controlling the dual motors and gearing associated with the rear drive wheels and the travel thereof through the medium of a hand held or cart mounted control device on a lanyard attached to the cart, and whereby charging of the battery may be effected by closing the circuit to the battery and manually pushing the cart to rotate the motor shafts and cycle the amperage back into the battery. 
       CROSS REFERENCE TO THE PRIOR ART 
       [0002]    While it has heretofore been proposed to provide a shopping service cart with a motorized wheel assembly unit, such as that of Swinny U.S. Pat. No. 3,190,386, and the self-propelled power units for picking up and handling unpowered shopping carts of Hudson U.S. Pat. No. 3,073,404 and Vokes U.S. Pat. No. 3,524,512, and a wheel chair driving and steering apparatus of Schmidt U.S. Pat. No. 2,978,053, none of these devices suggest a self-contained electric motor and battery propelled shopping cart which may be manually pushable or pullable to a shopping area and thereafter returned when loaded under power controlled by the operator walking along therewith and controlling its speed and travel by a control unit arranged on a lanyard attached to the cart. 
       SUMMARY OF THE INVENTION 
       [0003]    The principal object of this present invention is to provide a shopping service cart and burden carrier having dual electric motors and gearing associated with the rear driving wheels on the flat undercarriage thereof and with a storage battery interposed therebetween, and wherein a lanyard attached to the cart has a hand holdable control unit thereon for controling the speed and travel of the cart under power, and whereby the cart may also be manually pushed or pulled without power. 
         [0004]    Another object is the provision of a shopping service cart or the like wherein the main body storage area consists of a front end wall having an inverted U-shaped handle frame with wire mesh extending therebetween, a pair of wire mesh sides, and a generally rectangular insulated, hinged top storage chest at the rear end and also having an inverted U-shaped handle frame attached thereto, and wherein the walls and chest are removably interconnected and mounted on the flat undercarriage for disassembly and flat storage of the these components, as well as the separate use of the undercarriage. 
         [0005]    A further object is to provide a shopping service cart or the like wherein the lanyard fixedly attached thereto has a control unit arranged on the outer end thereof in which the motor controls and wiring are housed with the wiring extending through the lanyard to the battery and dual motors, so that the control unit may either be hand held for actuation by the operator walking in front of the cart or mounted on the rear handle for actuation by the operator from the rear. 
         [0006]    Still another object is the provision of a shopping service cart or the like wherein the battery thereof may be charged by actuation of switching means on the lanyard control unit to close the circuit to the battery and permit manual pushing of the cart in reverse so that no power is transmitted to the rear wheel gear trains and opposite rotation of the driving wheels causes the gears to rotate the motor shafts and act as a charging, direct current generator to produce current and cycle the amperage back into the battery. 
     
     
         [0007]    These and other objects and advantages will be apparent as the specification is considered with the accompaying drawings. wherein 
           [0008]      FIG. 1  is perspective view of an assebled cart showing the operator leading and controlling by the hand held control unit on the lanyard. 
           [0009]      FIG. 2  is an exploded perspective of cart with storage components disassembled from the undercarriage thereof; 
           [0010]      FIG. 3  is a front elevation; 
           [0011]      FIG. 4  is a side elevation, showing the lanyard control unit mounted on the rear handle; 
           [0012]      FIG. 5  is a bottom plan view, showing the battery, dual motor, gear and wheel assemblies; 
           [0013]      FIG. 6  is a bottom perspective view of the rear axle and battery assembly; 
           [0014]      FIG. 7  is a perspective view, partly broken away, of the insulated storage chest with top elevated; 
           [0015]      FIG. 8  is a perspective view of the lanyard control unit when mounted on the rear handle; 
           [0016]      FIG. 9  is a plan view of a rear drive wheel with its associated gear box broken away to show a gear train therein; 
           [0017]      FIG. 10  is a diagrammatic view of the control circuit from the lanyard control unit to the battery and dual motors; 
           [0018]      FIG. 11  is an exploded perspective view of a rear driving wheel, and its associated gear box, gear train, and D.C. motor. 
       
    
    
     DETAILED DESCRIPTION 
       [0019]    Referring more particularly to the drawings, wherein similar reference characters designate like part throughout the several views, the herein and about to be described shopping service cart generally approximates in size, height and shape a conventional basket type shopping cart of the type employed in retail grocery establishments and includes a generally rectangular flat undercarriage  1  having a pair of suitable driving or traction wheels  3  of suitable flow-molded plastic arranged on an aluminum axle  2  suspended and supported beneath the undercarriage  1  adjacent its rear end  4  by suitable brackets  5 . In the interest of reducing weight, the undercarriage  1  may be of a suitable high impact plastic, or aluminum. Supported by posts  6  suitably mounted in and depending from the front corners of the undercarriage  1  are a pair of smaller suitable wheels or casters  7  swivelly mounted, as at  8 , to the lower ends of the posts. A brace rod  9  extends between and serves to retain the posts in position. The rear wheels  3  are larger than the front wheels  7  and, as presently to be described, serve to propel the undercarriage and cart, whereas the smaller wheels, being swively mounted, enable the cart to be steered in an obvious manner. 
         [0020]    Removably supported on the upper surface of undercarriage  1  is a storage compartment  10  which includes a generally rectangular chest  11  having a top  12  hinged, as at  13 , and a suitable latch  14 . The chest may be formed of any suitable material and have an insulated lining, not shown, so that frozen packages and the like may be housed therein. Suitably affixed to a wall of the chest is an inverted U-sghaped tubular aluminum pipe  15  projecting a suitable distance above the top of  12  to provide a rear handle portion  16 . The chest may have suitable trunk handles  17  on the end walls thereof to facilitate handling thereof, and is preferably arranged at one end of the undercarriage  1 , such as the end above the rear drive wheels  3 . Dowel pins  3  may be provided at the lower corners of the chest for interfitting holes  19  in the undercarriage, and suitable latches  20  arranged thereon for securely but removably mounting and anchoring the chest on the undercarriage. Projecting upwardly from, and extending across the front end of the undercarriage is a front panel  21  of aluminum wire mesh  22  or suitable plastic of a height corresponding to that of chest  11 , suitably attached to an inverted U-shaped tubular aluminum pipe  23  projecting a suitable distance above the top  24  of the panel to provide a forward handle portion  25 . Dowel pins or the like  26  on the lower ends of pipe  23  interfit holes  27  in the undercarriage. Side panels  28 - 29 , similar to front panel  21  and extending therefrom to the rear wall  30  of chest  11 , may interfit suitable channels  32 , and the other ends of panels  28 - 29  may be removably attached, in any suitable manner, such as, by latches, not shown, to front panel  21 . The lower ends of the front and side panels may engage with L-shaped angles bars  32 , attached to the upper surface of undercarriage  1 , so as to assist in retaining these components thereon. Thus, it will be evident that the various storage comprtment units are securely, but removably, arranged on the undercarriage, and permit the latter to be used independently thereof when desired, as well as to facilitate storage. 
         [0021]    As best shown in FIGS.  3 , 5  and  11 , the shopping cart and the rear traction wheels  3  thereof are power operated by a pair of relatively small conventional 6-12 volt, D.C. electric motors  33 , suitably mounted on and oppositely projecting inwardly from gear boxes  34  suitably mounted on an supported by rear axle  2  parallel to and adjacent the inner side of each wheel. Referring to  FIGS. 9 and 11 , each motor  33  is so positioned that the armature shaft  35  thereof extends through an inner side wall  36  of the gear box and actuates the smallest gear  38  of a train of worm gears  37 . The largest gear  39  thereof is formed with a hub  40  which projects through as outer wall  41  or its gear box and drivingly interengages with a hub  42  of the wheel. Axle  2  projects through the gear boxes and the largest gears  39  thereof and through the wheel hubs  42 , so it will be apparent that the traction wheels  3  will be rotated and driven thereon in an obvious manner. 
         [0022]    A conventional 12 volt storage battery  43  is securely mounted and suspended beneath the undercarriage on a base plate  44  suitable horizontally affixed to the axle  2  and between the supporting brackets  5  thereof so that the battery top abuts the undercarriage and is suitably fixedly so positioned, as best in  FIG. 6 . Battery  43  is electrically connected to each of the motors  33  so that when a control unit, presently to be described, is actuated the traction wheels will be driven. 
         [0023]    An important feature hereof is the provision of a remote control operable by the user when walking in front and ahead or astern of the cart and maneuvering and controlling its rate of travel. Thus, an electrical lanyard or cable  45 , of any suitble material, such as, rubber or plastic, which is sufficiently strong and yet flexible to enable the used exerting an appropriate tug thereon when steering of the front wheels or casters  7 , is required and may be suitably securely anchored to the middle of the front brace rod  9 . 
         [0024]    Lanyard  45  is of sufficient length so that a control box  46  on the outer end thereof may be grasped in a hand of the user when walking ahead of the cart, or may be extended rearwardly over the storage compartment  10 , as shown in  FIG. 4 , where it may be mounted and supported on the rear handle  16 . A group of conductor wires  47  are encased within the lanyard and extend from within the control box  46  to a point intermediate the ends of the undercarriage where they project from the terminal and of the lanyard and are electrically connected to the posts of the battery  43  and the motors  33 , as shown in the diagram of  FIG. 10 . 
         [0025]    The control box  46  is generally rectangular and of a size for grasping and holding in a hand of the user when leading the cart, as in  FIG. 1 . A dowel pin  48  projecting from one side wall of the box may be inserted in a hole  49  in rear handle  16  to support the box thereat, as in  FIG. 4 , and thereby enable the cart to be controlled from the rear, as will hereinafter be described. Now referring to  FIGS. 6 and 10 , suitably arranged in control box  46  are a conventional rheostat  50 , conventional spring loaded push button switch  51 , normally open when released, closed when depressed, conventional double pole double throw cross wire (D.P.D.T.) switch  51 , and conventional blocking diode  53 , which are connected with the conductor wires  47 . It will be noted that the controls for the switches  51  and  52  and the rotatable knob for the rheostat are arranged on the top of the box so as to be available for actuation, whereby switch  51  controls power to the motors  33 , with the circuit to the battery and motors being closed when pressure is applied thereto; rheostat  50  functions to vary the voltage and speed of the motors; and the rotatable knob of the rheostat  50  also functions to hold down the push button switch  51  when this rotatable knob is swung over  51  thus closing the circuit and the D.P.D.T. switch control  52  can be placed in the charging mode D.P.D.T. switch  52  reverses the polarity of the current; and the blocking diode  53  allow current to flow one way to activate motors  33 , blocking the current when the D.P.D.T. switch  52  is reversed thus to stop the current flow from the battery to stop the motors. 
         [0026]    It will be understood that the cart may be readily operated by a walking operator and, by dismantling the storage compartment components from the undercarriage, enable suitable storage thereof, as well as permitting the individual and seperate use of the undercarriage as a truck. The most significant use would be as a shopping service cart, in which event the operator may push the cart, either or without power, to the supermarket and continue pushing it thereat without power until shopping is completed with any frozen food stored in the insulated chest. After checking out and leaving, the operator may stand behind the loaded cart, grasping the rear handle thereof, and, after first pushing the cart to impart movement thereto, actuate the controls on the control box thereon, and guiding under power of the motors so that any terrain may be travelled without effort by the operator, other than steering. The cart may also be controlled and operated with the operator in the lead and the lanyard control box in hand so that the cart trails under power and is steered by tugs on the lanyard. as low gearing trains are arranged in the gear boxes associated with the rear traction wheels, no brake system is required. When being operated under power and an upgrade is encountered, the cart will slow down and then be controlled by the operator. On the other hand, on a downgrade the cart will coast at a very slow rate and is controllable with a little restraint. 
         [0027]    Charging of the storage battery  43  is effected by actuating D.P.D.T. switch  52  to its designated charging position and the rotatable knob of the rheostat control  50  is rotated directly over the push button switch  51  to hold it down and keep the circuit closed, and by the operator pushing the cart in reverse without electric power so that the traction wheels rotate clockwise and similarly rotate the motor shafts  35  through the trains of gearing  37 . Thus the D.C. motors  33  will be driven in reverse of their wired polarity to act as generators producing current cycling the amperage back into and charging the battery. During the charging operation, heat will be dissipated from the armatures and brushes which gives longer life to these components. In the usual electrically operated rider operated vehicles, such as, a power lawn mower or golf cart, a large initial amount of current is required to get the vehicle moving until it can build up needed electrical force or breakway power, which usually is about three times that required to operate the vehicle. On the other hand, it is only necessary for the operator to get the present cart moving a few feet before starting the motors so that breakway power is not needed, and a saving in electrical energy effected. 
         [0028]    While a preferred embodiement of a electrically powered shopping service cart has been shown and described, it is to be understood that various changes and improvements may be made therein without departing from the scope and spirit of the appended claims.