Abstract:
A suitcase has retractable telescoping legs that are stored on the edges of the suitcase and are deployed into a position with respect to the suitcase that resembles a hospital gurney. The suitcase is then oriented horizontally but in a location that is elevated to be convenient for packing or unpacking. The legs have casters on them and are telescoped and folded adjacent to edges of the suitcase during storage so the legs are out of the way, but with the casters located adjacent to one edge of the suitcase in the manner of wheeled suitcases.

Description:
TECHNICAL FIELD OF THE INVENTION 
       [0001]    The present invention relates in general to automatically extendable and retractable wheel assemblies, and in particular to luggage having wheel assemblies. 
       BACKGROUND OF THE INVENTION 
       [0002]    As early as the late nineteenth century, patent literature showed large wooden trunks with small metal wheels built into wood strips or skids. Conventional suitcases having either two or four wheels have been standard in the industry for years. Wheels are popular on horizontal cases, known as “pullman” cases, and upon “vertical” cases adapted to be rolled across a supporting surface with the major dimension of the case disposed at an angle to the supporting surface. 
         [0003]    A pullman case has wheels attached to the bottom wall of the case, and the case is towed on these wheels by a strap or handle attached on an end wall near an upper corner of the case. A conventional wheeled pullman has two fixed-axis wheels spaced from one another along the relatively narrow width dimension of the case to support the back end of the case. A pair of caster type wheels support the front end of the case. The user pulls the case around on these four wheels as if it were a rather narrow, tall wagon. 
         [0004]    Recently, pullman cases have declined dramatically in popularity with luggage users. One of the reasons for the declining popularity of wheeled pullman cases is their relative instability while being wheeled. Pullman cases manifest a tendency to fishtail or tip while being towed, and are perceived generally to be difficult to steer. 
         [0005]    Another style of wheeled case is the immensely popular vertical, or “upright,” luggage case. A typical upright case has a pair of fixed axis wheels spaced along a long edge defined by the intersection of the back and the bottom of the case. These wheels are oriented so that the case is rolled broadside. The upper face of the case has a handle with which the user balances the case on these two wheels. 
         [0006]    Known upright wheeled luggage cases often manifest either one, or both, of two problems: user discomfort and instability. Most commonly encountered wheeled uprights must be tipped from a vertical position and towed on two wheels—requiring constant support from the user in order to remain upright—posing the problem of strain and discomfort in the user&#39;s arm. A conventional upright luggage has a pull handle which typically is retractable/extendable and configured to be gripped in one hand and used to tow the luggage. The two wheels normally are mounted on an edge of the bottom of the case, and the case is tipped toward the user to be positioned for towing. Furthermore, this kind of luggage has the disadvantage of having to be held all the time to prevent it from sliding away when a car or train travels at a high speed or stops suddenly. If a car or train is crowded, then it is easy to damage the wheel assembly of this type of luggage when getting into or out of a car or train. The luggage has to be placed in a flat position in order to prevent it from sliding about on its wheels, and as a result, requires more space for storage, which is a disadvantage when the car or train is crowded. 
         [0007]    The user must then constantly support and steady the case in the tilted wheeling position, with a significant portion of the weight of the case borne by the user&#39;s rearwardly outstretched arm. A possible solution to user discomfort is the provision of additional wheels upon the bottom of the upright case, whereby the case may stand in a balanced upright position upon three or more wheels with no weight borne by the user&#39;s arm. However, for such a case to be satisfactorily stable when pushed or pulled, it must satisfy minimum requirements for wheel base length, that is, the distance between the front wheels and the back wheels, measured between respective axles and generally parallel to the direction of travel. 
         [0008]    Luggage users for a variety of reasons increasingly demand “carry on” luggage, i.e., luggage sized to be carried into the passenger sections of aircraft, buses, and other common carriers. Carry on luggage must be easily carried, but also must satisfy certain restrictive exterior dimensional criteria imposed by airlines so to be small enough to fit in overhead or under-seat storage compartments. 
         [0009]    Many people lift their suitcases to a higher surface to facilitate packing or unpacking. This can be difficult under any circumstances, but may be especially onerous if the person is disabled or infirm. Therefore, there is a need for a luggage device that can combine the advantages associated with pullman cases with the advantages associated with upright cases. 
       SUMMARY OF THE INVENTION 
       [0010]    The above-discussed disadvantages of the prior art are overcome by a suitcase having retractable telescoping legs that are stored on the edges of the suitcase and are deployed into a position with respect to the suitcase that resembles a hospital gurney. The suitcase is then oriented horizontally but in a location that is elevated to be convenient for packing or unpacking. The legs have casters on them and are telescoped and folded adjacent to edges of the suitcase during storage so the legs are out of the way, but with the casters located adjacent to one edge of the suitcase in the manner of wheeled suitcases so the suitcase embodying the present invention has the desirable characteristics of a pullman suitcase and a vertical wheeled suitcase, without the disadvantages of either. 
         [0011]    Other systems, methods, features, and advantages of the invention will be, or will become, apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the invention, and be protected by the following claims. 
     
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0012]    The invention can be better understood with reference to the following drawings and description. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. Moreover, in the figures, like referenced numerals designate corresponding parts throughout the different views. 
           [0013]      FIG. 1  is a perspective view of a suitcase embodying the present invention with the legs in a deployed condition. 
           [0014]      FIG. 2  is an elevational view of the suitcase embodying the present invention with the legs in a stored condition. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0015]    Referring to the figures, it can be understood that the present invention is embodied in a suitcase  10  that can be used in the manner of both a pullman type case and an upright wheeled case. Suitcase  10  comprises a case unit  12  which includes a first end wall  14  which is a bottom end wall when the case unit is in an upright orientation. First end wall  14  has a first side edge  16  which is a top side edge when the case unit is in a horizontal orientation, a second side edge  18  which is a bottom side edge when the case unit is in a horizontal orientation, a first end edge  20  which connects the first side edge of the first end wall to the second side edge of the first end wall, and a second end edge  22  which connects the first side edge of the first end wall to the second side edge of the first end wall. 
         [0016]    Case unit  12  further includes a second end wall  30  which is a top end wall when the case is in the upright orientation. Second end wall  30  has a first side edge  32  which is a top side edge when the case unit is in a horizontal orientation, a second side edge  34  which is a bottom side edge when the case unit is in a horizontal orientation, a first end edge  36  which connects the first side edge of the second end wall to the second side edge of the second end wall, and a second end edge  38  which connects the first side edge of the second end wall to the second side edge of the second end wall. 
         [0017]    Case unit  12  further includes a first side wall  40  which extends between the first and second end walls of the case unit. First side wall  40  has a first side edge  42  which is a top side edge when the case unit is in a horizontal orientation, a second side edge  44  which is a bottom side edge when the case unit is in a horizontal orientation, a first end edge  46  which connects the first side edge of the first side wall to the second side edge of the first side wall and which is coincident with first end edge  20  of the first end wall, and a second end edge  48  which connects the first side edge of the first side wall to the second side edge of the first side wall and which is coincident with first end edge  36  of the first end wall. 
         [0018]    A second side wall  50  extends between the first and second end walls of the case unit and is similar to the first side wall. Second side wall  50  has a first side edge  52  which is a top side edge when the case unit is in a horizontal orientation, a second side edge  54  which is a bottom side edge when the case unit is in a horizontal orientation, a first end edge  56  which connects the first side edge of the second side wall to the second side edge of the second side wall and which is coincident with second end edge  22  of the first end wall, and a second end edge  58  which connects the first side edge of the second side wall to the second side edge of the second side wall and which is coincident with second end edge  38  of the second end wall. 
         [0019]    Case unit  12  further includes a first surface  60  which is a top surface when the case unit is in a use orientation and a second surface  62  which is a bottom surface when the case unit is in a horizontal orientation. The case unit is hollow with a storage volume  64  defined therein. A rack unit  70  is mounted on the case unit. The rack unit supports the case unit in the manner of a pullman case when the rack unit is deployed as shown in  FIG. 1 . Rack unit  70  includes a first frame  72  that is located adjacent to the bottom end wall of the case unit and a second frame  74  that is located adjacent to the second surface of the case unit. 
         [0020]    Second frame  74  includes a first frame element  80  that is located adjacent to second side edge  44  of the first side wall and which extends between the first and second end walls of the case unit, and a second frame element  82  that is located adjacent to second side edge  54  of the second side wall and which extends between the first and second end walls of the case unit. 
         [0021]    A third frame element  90  is located adjacent to second side edge  18  of the first end wall. A first wheel  94  is rotatably mounted on the rack unit adjacent to second side edge  44  of the first side wall, and a second wheel  96  is rotatably mounted on the rack unit adjacent to second side edge  54  of the second side wall. 
         [0022]    A first telescoping leg  100  is pivotally mounted on the rack unit adjacent to first wheel  94 . The first telescoping leg is pivotally movable between a stored position shown in  FIG. 2  adjacent to the second side edge of the first side wall and a deployed position shown in  FIG. 1  that is oriented at an oblique angle to the second side edge of the first side wall. First telescoping leg  100  includes a distal end  102  and a wheel  104  rotatably mounted on the distal end of the first telescoping leg. 
         [0023]    A second telescoping leg  110  is pivotally mounted on the rack unit adjacent to second wheel  96 . Second telescoping leg  110  is pivotally movable between a stored position shown in  FIG. 2  adjacent to the second side edge of the second side wall and a deployed position shown in  FIG. 1  that is oriented at an oblique angle to the second side edge of the second side wall. Second telescoping leg  110  includes a distal end  112  and a wheel  114  rotatably mounted on the distal end of the second telescoping leg. 
         [0024]    A third telescoping leg  120  can also be included to add stability to the rack unit and is pivotally mounted on the case unit adjacent to end edge  38  and the second surface of the case unit. The third leg moves in the manner just described for the first and second legs but extends opposite to the second leg. A support frame element  130  is mounted on the first end wall and supports the case unit when the case unit is in an upright orientation. A handle  150  is mounted on the second end wall and is used to carry the case unit. 
         [0025]    As can be understood from the teaching of the foregoing disclosure, rack unit is folded into the stored condition shown in  FIG. 2  and the case unit can be moved and carried in the manner associated with an upright wheeled unit. However, the rack unit can be unfolded into the deployed condition shown in  FIG. 1  so the case unit can be supported in a horizontal orientation shown in  FIG. 1  for easy access to the inside of the case for packing and unpacking. The rack unit will be strong enough to stably support the case unit when the case unit is in the  FIG. 1  horizontal orientation. 
         [0026]    While various embodiments of the invention have been described, it will be apparent to those of ordinary skill in the art that many more embodiments and implementations are possible within the scope of this invention. Accordingly, the invention is not to be restricted except in light of the attached claims and their equivalents.