Abstract:
An adaptable luggage cart or suitcase handle that is configured to accommodate an assortment of positions is presented. The adaptable handle includes secondary grip extensions that exist within the contours of a traditionally-shaped luggage cart handle and are capable of attaining a more comfortable, extended grasping position than a traditional handle. The extended position of the convertible handle allows the user to switch from a palms-down or a palms-up grasping position to a palms-inward position that emulates the grip a snow skier makes on a ski pole. Furthermore, once in the extended position, the handle of the present invention can be configured in a wide assortment of extension angles to increase the comfort to the user.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not Applicable. 
     TECHNICAL FIELD OF THE INVENTION 
     The present invention relates generally to devices used to transport or tow heavy objects. 
     More particularly, the present invention relates to a wheeled dolly for transporting heavy objects or luggage. More particularly still, the present invention relates to a convertible handle for a wheeled dolly that is configured to change from a standard position to an alternative position that is more comfortable to the user. 
     BACKGROUND OF THE INVENTION 
     Various devices have been used to assist people in transporting objects that are either too heavy or bulky to carry comfortably without assistance. A common example of such device is known to many as a luggage cart or a suitcase dolly. Luggage carts typically include a small frame with a handle and a single pair of parallel wheels. An object to be transported, often a suitcase or file box, is placed upon the frame and held in place, either by straps, elastic cords, or by its own weight. The user then grasps the handle and tilts the cart about the axis of the wheels until a substantial portion of the weight of the object is supported by the wheels. Once in this position, the user is able to pull and maneuver the cart with ease from one location to another. The weight of the object is substantially carried by the pair of wheels which, when coupled to the frame by proper bushings or bearings, enables the user of the luggage cart to transport objects that would otherwise be too difficult or heavy to carry. The single pair of parallel wheels gives the luggage cart increased maneuverability, thus enabling the user to direct their objects through crowded or obstructed areas easily. Luggage carts are preferably designed to be collapsed into a reduced profile so as to enable the user to more easily transport the device. Typically, the frame folds together while the handle apparatus collapses, often telescopically, into a shortened position. Once compacted, the luggage cart is capable of being easily transported, often taking up little more space than a portable computer. 
     Frequently, containers that are expected to transport relatively heavy objects are manufactured with a cart of this type integral to the container design. A common example of a container of this design is the “traveler” design suitcase. Such a case includes a set of integrated wheels at its bottom and a retractable handle at its top. Once a traveler reaches his or her destination, they are then able to extend the handle, tilt the suitcase about the axis of the integral wheels, and transport the case by grasping and pulling the handle. Frequently, such a case will include a provision, in the form of hooks or accessory platforms, that enables the attachment of other bags to the wheeled case. This design is a favorite among travelers that must carry more than one bag thus enabling them to transport all of their luggage using a single handled device. 
     One drawback to the luggage carts and traveler suitcases currently available on the market is the limited amount of comfort they allow the operator. While great advances have been made to increase the durability and compactability of such carts, little has been done to improve their ergonomic characteristics. Particularly, most luggage carts and wheeled suitcases include a handle that is substantially parallel to the axis of rotation about which the wheels rotate. This requires the user to pull the device with their hand in either a palms-up or palms-down position. While such a position for the handle may be acceptable for some users, others find such a position uncomfortable, if not painful, during extended periods of use. A collapsible luggage cart or traveler suitcase with a retractable handle having improved ergonomics than what is currently available would be highly desirable and beneficial to consumers. The present invention addresses the shortcomings of the prior art. 
     SUMMARY OF THE INVENTION 
     The present invention overcomes the deficiencies of the prior art by providing an adaptable handle for dollies, luggage carts, and suitcases that is configured to accommodate an assortment of positions. The adaptable handle includes secondary grip extensions that are disposed within the contours of a traditionally-shaped handle and are capable of attaining a more comfortable, extended grasping position than a traditional handle. The extended, or forward-facing, position of the convertible handle allows the user to switch from a palms-up (or palms-down) grasping position to a palms-inward position that emulates the grip a snow skier makes on a ski pole. 
     Furthermore, once in the extended position, the handle of the present invention can be configured in a wide assortment of extension angles to increase the comfort to the user. The features, above and collectively, provide substantial ergonomic advantages and allow for longer, more comfortable periods of use. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     For a more detailed description of the preferred embodiment of the present invention, reference will now be made to the accompanying drawings, wherein: 
     FIG. 1A is a schematic view drawing of a luggage cart assembly with a convertible handle in accordance with a preferred embodiment of the present invention, the handle being disposed in a first configuration; 
     FIG. 1B is a schematic view drawing of the luggage cart assembly of FIG. 1A with the convertible handle in a second, forward-facing configuration; 
     FIG. 2A is a top view schematic drawing of the handle of the luggage cart of FIG. 1A; 
     FIG. 2B is a front view schematic drawing of the handle of the luggage cart of FIG. 1A; 
     FIG. 2C is a side view schematic drawing of the handle of the luggage cart of FIG. 1A; and 
     FIG. 3 is a top view schematic drawing of the handle of the luggage cart of FIG. 1B; 
     FIG. 4A is a side view schematic drawing of a traveler suitcase having an integral convertible handle in accordance with another preferred embodiment of the present invention, the handle being shown in a second forward-facing configuration; 
     FIG. 4B is a front view schematic of the integral traveler suitcase of FIG. 4B; 
     FIG. 5A is a schematic side view drawing of a convertible handle assembly in accordance with another preferred embodiment of the present invention with the handle in the retracted position; 
     FIG. 5B is a schematic front view drawing of the handle of FIG. 5A; 
     FIG. 5C is a schematic side view of the handle of FIG. 5A wherein the handle is in an extended or forward-facing position; 
     FIG. 5D is a schematic side view of the handle of FIG. 5A wherein the handle is in another extended or forward-facing position; 
     FIG. 5E is a side view drawing of the convertible handle assembly of FIG. 5D attached to a wheeled suitcase; 
     FIG. 6A is a schematic front view similar to FIG. 2B showing an alternative preferred embodiment of the present invention in which the convertible handle includes ergonomic handle extensions, wherein the extensions are in a nested position; and 
     FIG. 6B is a schematic front view of the convertible handle with ergonomic handle extensions of FIG. 6A, wherein the extensions are in an extended position. While a preferred embodiment of the invention is shown and described, modifications thereof can be made by one skilled in the art without departing from the spirit of the invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring initially to FIGS. 1A-B, a schematic representation of a luggage cart or transport apparatus  10  is shown. Luggage cart  10  includes a base  12 , a back  14 , a pair of parallel wheels  16 , and a handle  18 . It is preferable that base  12  and back  14  meet substantially perpendicular at a line of intersection that defines an axis  19  for wheels  16 . A load  20 , typically in the form of a box or suitcase, is placed upon base  12  and against back  14  and can be secured with straps or cords (not shown) or any other type of retaining apparatus. If load  20  is heavy enough, straps or another retaining apparatus may not be necessary, the load above providing enough stability to keep it in place. 
     Handle  18  is constructed as a convertible device and includes a main body  30  and at least one extension grip  32 . FIG. 1A shows extension grip  32  in a first position nested within main body  30 , while FIG. 1B shows grip  32  in an extended, forward-facing position. In the extended position of FIG. 1B, grip  32  defines an angle of inclination a with back  14 . Although angle of inclination a is shown in FIG. 1B as approximately 90°, it should be understood that various angles may be employed. Particularly, handle  18  may be constructed such that angle a between grip  32  and back  14  may be fully adjustable to accommodate the height of the user and other user preferences. 
     Referring now to FIGS. 2A-C, the handle  18  of transport apparatus  10  is shown in more detail. FIG. 2A, a top view, details handle  18  in a contracted or nested position from a top view and shows main body  30 , left and right extension grips  32   a ,  32   b  respectively, and pivot screws  34   a ,  34   b . FIG. 2B details the same handle of FIG. 2A in a front view and FIG. 2C details handle  18  from the side. In FIGS. 2B-C, the extensions to the frame  14  of cart  10  can be shown protruding from the bottom of main body  30  of handle  18 . 
     Referring specifically now to FIG. 2C, the cutaway, or recess  31  in main body  30 , for containing the nested extensions  32   a ,  32   b  can be seen. Recess  31  is formed as a cutout and includes back surface  36  and bottom surface  38 . Although handle assembly  18  is shown as primarily square-shaped in FIGS. 1-4, it should be noted that handle  18  can be contoured to any geometry desired by the manufacturer. Examples of such geometries favorable to consumers would include circular cross sections (as shown in FIG. 5) or cross sections molded to replicate the contours of the operator&#39;s hand as shown in FIGS. 6A-B. 
     Referring to FIGS. 2-3 collectively, the operation of handle  18  can be described. In the contracted or nested position (shown in FIGS. 1A,  2 A-C), handle  18  is capable of being used as any other luggage cart handle. In this position, the operator grasps handle  18  along its length, tilts cart  10  about the axis  19  of wheels  16 , shifting the weight of load  20  over wheels  16 , and pulls cart  10  as he or she walks to their destination. While the operator is using cart  10  with handle  18  in the contracted position, the hand used to pull cart  10  is rotated such that its palm is pointed substantially upward or, in some instances, downward. For many users, these positions are not comfortable and can become painful after prolonged use. 
     To alleviate such discomfort, the operator is able to reconfigure handle  18  into the extended, or forward-facing, position by swinging grips  32   a ,  32   b  about their respective pivot points  34   a ,  34   b  until the grips meet together as shown in FIG.  1 B and FIG.  3 . Once in the extended position, the user is now able to grasp the new handle  40 , created by the meeting of extensions  32   a  and  32   b , along its length. As before, the user grasps handle  40 , tilts cart  10  forward about axis  19  of wheels  16  and pulls cart  10  as he or she walks. In this position, the user&#39;s hand is more comfortably placed, preferably with the palm substantially inward and the thumb downward as if gripping a ski thrust pole. 
     Although a single-axis pivot screw  34   a ,  34   b  is shown in FIGS. 2-3, it should be understood that compound, multi-axis pivot devices may be used instead to allow the user to extend extensions  32   a ,  32   b  as well as manipulate the extension angle α. Additionally, a wide assortment of devices may be employed upon handle  18  to maintain grips  32   a ,  32   b  in a desired angular position a, such that its position will not change as the user tows cart  10 . Such devices may include, but are not limited to straps, ratchets, snap in place features (i.e. detent position stops), and viscous or coulombic friction features (i.e. rubber washers to resist repositioning). FIG.  2 B and FIG. 3 show detent upsets  42   a ,  42   b  upon main body  30  to retain grips  32   a ,  32   b  in the retracted position. 
     Referring now to FIGS. 4A-B a convertible handle  50  is shown attached to an integrated traveler suitcase  100 . Traveler suitcase  100  includes a compartment  102 , a pair of wheels  104 , a back side  106 , and a top side  108 . Protruding from top side  108  of suitcase  100  are two telescopic extension poles  110 ,  112  and a lifting handle  114 . Telescopic poles  110 ,  112  are configured to raise and lower away from and towards top  108  of suitcase  100  and to provide a mounting location for convertible handle  50 . Convertible handle is constructed in the same manner as handle  18  of FIGS. 1-3 and therefore includes a main body  52  and a pair of extensions  54   a ,  54   b . Unlike dolly  10  of FIGS. 1A-B, there is no exterior frame ( 14 ) and base ( 12 ) for suitcase  100 , as those components are integrated with the suitcase frame within compartment  102 . Compartment  102  of suitcase  100  includes all the structural reinforcement along its back side  106  necessary to allow poles  110 ,  112  to transmit loads from handle  50  to wheels  104 . 
     When convertible handle  50  is desired for transporting suitcase  100 , the user simply raises handle  50  through the extension of poles  110 ,  112  and converts grips  54   a ,  54   b  into the desired position as shown in FIG.  4 A. As described above, the inclination angle a may be adjusted or preset to accommodate the users preference or may simply be fixed to one position. When handle  50  is no longer needed, grips  54   a ,  54   b  are retracted to their nested position within main body  52 , and telescopic poles  110 ,  112  are retracted, allowing handle  50  to be retracted within a recess (not shown) formed within back  106  and top  108  sides of suitcase  100 . With handle  50  fully retracted, lifting handle  114  may be used for simple positioning and lifting. 
     Referring now to FIGS. 5A-E, an alternative embodiment to the handles  18 ,  50  of FIGS. 1-4 is shown. Alternative handle  60  is constructed with a substantially circular main body  62  from which two extensions  64   a ,  64   b  extend. Handle  60  meets with mounts  70   a ,  70   b  at a curve of intersection  72 . When extended, grips  64   a ,  64   b  form an angle γ with respect to mounts  70   a ,  70   b  as shown in FIG.  5 C. Because main body  62  is round in cross-section, a slot and groove arrangement (not shown) may be employed to allow the position of grips  64   a ,  64   b  with respect to mounts  70   a ,  70   b  to change to a new angle δ as shown in FIG.  5 D. The change from γ to δ enables the user to rotate grips  64   a ,  64   b  to an angle greater than 90° so as to enable the tilting of luggage cart  10  or wheeled suitcase  100  to the most desired position (preferably substantially parallel to the ground  80 ) according to the user&#39;s size and towing preferences while maintaining grips in a comfortable, forward-facing configuration as shown in FIG.  5 E. This permits the user to adapt handle  60  to better suit or optimize their comfort. 
     FIGS. 6A-B shows an ergonomic handle  90  in accordance with another preferred embodiment of the present invention in retracted (FIG. 6A) and extended (FIG. 6B) positions. Handle  90  includes two contoured grip extensions  92   a ,  92   b  with grip contours,  93   a ,  93   b  respectively, that are extended together to form contoured secondary grip  94 . Because contours  93   a ,  93   b  are shaped to fit the contours of the user&#39;s hands, extended secondary grip  94  will be more comfortable to the user for longer periods of use. 
     While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the intention is to cover all modifications, equivalents and alternatives falling within the spirit and scope of the present invention as defined by the appended claims.