Abstract:
A bag, comprises a bottom support member and a pair of wheels secured to the bottom support member. A scale disposed on the bottom support member has an electrical output. A compartment is configured and dimensioned to hold the contents of the bag. The scale is disposed between the bottom support member and the compartment. The compartment is movably mounted with respect to the bottom support member. This causes items contained within the compartment tend to apply their weight to the scale. A readout is electrically coupled to the electrical output of the scale.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to apparatus and methods for determining the weight of luggage. 
       CROSS REFERENCE TO RELATED APPLICATIONS 
       [0002]    (Not applicable) 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0003]    (Not applicable) 
       BACKGROUND OF THE INVENTION 
       [0004]    Increasingly, airlines are imposing restrictions on carry-on luggage both relating to the number of pieces and the weight which the traveler is allowed to bring on a trip without incurring extra fees. Last minute purchases, shifting weight between carry-on and checked luggage, and the like complicate the task of meeting airline restrictions. In addition, scales commonly available in homes, such as scales for measuring body weight do not easily lend themselves to weight determinations. While specialized small scales are available, the same are difficult to use due to the weight of heavier items of luggage. 
       SUMMARY OF THE INVENTION 
       [0005]    In accordance with the invention, the problem of determining the weight of luggage is solved by providing a bag which weighs itself and its contents. 
         [0006]    More particularly, in accordance with the invention, a bag comprises a bottom support member and a pair of wheels secured to the bottom or side support member. A scale disposed on the bottom or side support member has an electrical output. A compartment is configured and dimensioned to hold the contents of the bag. The scale is disposed between the bottom support member and the compartment. The compartment is movably mounted with respect to the bottom support member. This causes items contained within the compartment tend to apply their weight to the scale. A readout is electrically coupled to the electrical output of the scale. 
         [0007]    In accordance with the invention, the compartment may comprise a compartment bottom and a compartment back, with the compartment back secured to the compartment bottom, and the compartment bottom being made of a relatively stiff material. A side support member may be secured to the bottom support member. The compartment back is slidingly mounted with respect to the side support member. 
         [0008]    The bag may further comprise a telescoping member secured to the side support member, and a handle secured to the telescoping member. 
         [0009]    The compartment bottom may be made of steel or a fiber-reinforced plastic. 
         [0010]    The compartment may comprise a fabric member, a compartment bottom and a compartment back. The compartment back may be secured to the compartment bottom. The compartment bottom may be relatively stiff. The fabric member may be secured to the compartment back and the compartment bottom. 
     
    
     
       BRIEF DESCRIPTION THE DRAWINGS 
         [0011]    The operation of the invention will become apparent from the following description taken in conjunction with the drawings, in which: 
           [0012]      FIG. 1  is perspective view of a bag of the present invention; 
           [0013]      FIG. 2  is a side view of the bag illustrated in  FIG. 1 ; 
           [0014]      FIG. 3  is a top plan view of the bag illustrated in  FIG. 1 ; 
           [0015]      FIG. 4  is a cross-section of the bag according to the present invention in the vertical position; 
           [0016]      FIG. 5  is a cross-section of the bag according to the present invention in the tilted rolling position; 
           [0017]      FIG. 6  is a perspective view of an alternative embodiment of the invention with a sliding compartment; 
           [0018]      FIG. 7  illustrates in cross-section the relationship of the compartment and bag in an embodiment with a sliding compartment; 
           [0019]      FIG. 8  is a top plan view of the embodiment of the invention of  FIG. 7  with a sliding compartment; 
           [0020]      FIG. 9  is a view of a bag with a sliding compartment in the vertical position; 
           [0021]      FIG. 10  is a detail showing the relationship of the compartment and support in the inventive bag in the vertical position; 
           [0022]      FIG. 11  is a detail showing the relationship of the compartment and support in the inventive bag in the rolling position; 
           [0023]      FIG. 12  is a detail showing the relationship of the compartment and support in the inventive bag in the rolling position; 
           [0024]      FIG. 13  is a side view in diagrammatic form of a scale component useful in the bag of the present invention; 
           [0025]      FIG. 14  is a top view of a scale component useful in the bag of the present invention; 
           [0026]      FIG. 15  is a view of another alternative embodiment of the present invention; 
           [0027]      FIG. 16  is a top plan view of an embodiment of the invention with an enlarged weight display and clock; and 
           [0028]      FIG. 17  is an alternative embodiment of the invention showing a different scale readout location. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0029]    Turning to  FIG. 1 , an item of luggage  10 , constructed in accordance with the present invention, is illustrated. Luggage  10  comprises a fabric compartment  12  having the main body portion  14  and a lid portion  16 . 
         [0030]    Of course, any suitable material for a bag may be used, such as leather, vinyl, rigid plastic, nylon, cardboard and so forth. Likewise, the luggage of the present invention may include additional materials, such as an insulating layer, shock absorbing layer, a waterproofing material such as Gortex, and so forth. 
         [0031]    Main body portion  14  and a lid portion  16  are secured to each other by a zipper  18  which is secured to fabric compartment  12  by stitches  20 . Fabric compartment  12  is secured to a rigid plastic support  22 , as illustrated most clearly in  FIG. 2 , which shows the inventive luggage bag  10  in cross-section. Support  22  comprises a bottom portion  24  and a backing portion  26 . Bottom portion  24  and backing portion  26  are integrally formed with a horizontal top plate  25 . In accordance with a preferred embodiment, bottom portion  24  is relatively stiff, and if desired, may be made of graphite reinforced plastic composite. Fabric compartment  12  is secured to support  22  forming a housing  27  for containing the contents of luggage bag  10 . 
         [0032]    Bag  10  further comprises a handle  28 . Handle  28  may be sewn in position or secured in any conventional matter. 
         [0033]    Bag  10  further comprises a rolling support  30  which is made of a base  32  and a back  34 . Housing  27  is slidingly mounted with respect to rolling support  30 . More particularly, backing portion  26  of support  22  slides with respect to back  34  of rolling support  30 . Movement is limited by a pair of pins  36  which move in elongated holes or slots  38 . Pins  36  may be secured to back  34  and loosely slide in slots  38 , allowing housing  24  to move up and down in response to the weight of its contents. 
         [0034]    A scale  38  is positioned within a compartment  40  in base  32  of support  30 . In proportion to the weight contained within housing  27 , forces applied to scale  38  cause scale  38  to generate the measurement of the weight of housing  27  and its contents. Scale  38 , whose construction is described below, is programmed to add the weight of the remainder of bag  10  to provide the total weight of the luggage. 
         [0035]    More particularly, the output of scale  38  is sent to a digital display  42 , as illustrated most clearly in  FIG. 3 . A push button  44  may be provided to switch the scale between kilograms and pounds, in a manner well known in the art. 
         [0036]    In a manner well-known in the art, bag  10  is provided with a pair of wheels  46  and a foot  48 . Bag  10  also includes a pair of telescopic members  50  attached to a handle  52 . Telescopic members  50  may be extended as illustrated in  FIG. 4 , allowing the bag to be tilted as illustrated in  FIG. 5  and easily transported. 
         [0037]    It is intended that in accordance with the present invention that the dimensions of the bag may be changed, so that the largest area side is the bottom of the bag. In this case, the scale may be placed on the small area side of the bag and the display placed on the opposite side of the bag. 
         [0038]    An alternative embodiment of the invention is illustrated in  FIGS. 6-9 . This embodiment is substantially identical to that of  FIGS. 1-5  except that bag  110  comprises a housing  127  which is displaced from base  132  overall and support  30  when the bag is being moved to the position illustrated in  FIG. 11 . 
         [0039]    As can be seen most clearly in  FIG. 10 , when bag  110  is in the position of  FIG. 9 , housing  127  is urged by its contents toward base  132 , applying pressure to scale  138 . As shown most clearly in  FIG. 12 , when bag  110  is put in the position illustrated in  FIG. 11 , it slides away from base  132 , thus removing pressure from scale  138 , and increasing the expected lifespan of scale  138 . In other words, when the inventive bag  110  is tilted from the position shown in  FIG. 9  to the position shown in  FIG. 11 , the luggage containing compartment housing  127  slides toward back  134 , thus removing weight from scale  138 . Conversely, when the inventive bag  110  is brought back to the position shown in  FIG. 9  from the position shown in  FIG. 11 , the luggage containing compartment housing  127  slides toward base  132 , thus applying weight to scale  138 . 
         [0040]    This action is facilitated by a pair of facing Teflon strips  180  and  182  which are secured to inclined surfaces  184  and  186  on housing  127  and base  132 . 
         [0041]    In accordance with the present invention it is contemplated that any prior art scale mechanism may be used, for example a scale of the type disclosed in U.S. Pat. No. 4,765,422 to Hoffmann dated Aug. 23, 1988. 
         [0042]    Generally, the most common type of strain gauge consists of an insulating flexible backing which supports a metallic foil pattern. The weight of the contents of the bag of the present invention is applied to the metallic foil pattern to deform it, by applying weight to the substrate supporting the foil pattern. As the substrate is deformed, the foil is deformed, causing its electrical resistance to change. This resistance change, usually measured using a Wheatstone bridge, is related to the strain by the quantity known as the gauge factor. 
         [0043]      FIGS. 13 and 14  show a scale  38 , suitable for use in either of the above embodiments, which comprises a lower portion or base  210  and a plate-like carrier  215  which rests on the central portion of the base  210 , and an upper portion platform  211  which supports compartment  27 . The underside of the platform  211  carries two knife edge bearings  214  which rest on spaced-apart portions of the upper side of the carrier  215 . 
         [0044]    The carrier  215  rests on two spaced-apart supports  216  which are provided therefor on the base  210  beneath the bearings  214 . The distance between the supports  216  exceeds the distance between the bearings  214 , and the bearings are disposed between the supports so that the carrier  215  is flexed between the supports  216  in response to the application of a load by way of the bearings  214 , i.e., in response to the application of a load to the platform  211  so that the latter descends slightly and deforms the carrier  215 , whereby the latter assumes a substantially concave-convex shape with the concave side facing upwardly toward the underside of the platform  212 . 
         [0045]    When a load is applied to the platform  211 , the carrier  215  undergoes a deformation which is proportional to the applied load (such load is transmitted by the knife edge bearings  214 ), whereby the length of the conductor  222  ( FIG. 14 ) changes to bring about a proportional change of its resistance. This is detected by the circuit including conductors  224 ,  225 , amplifier  250 , energy source  251  and a microprocessor  252  which generates a digital number sent to digital display  42 . 
         [0046]    Referring to  FIG. 15 , a bag  310  constructed in accordance with the present invention comprises a compartment  327  forms of fabric  329  secured to frame bottom  331  and frame side  333 . 
         [0047]    Referring to  FIG. 16 , an alternative embodiment of the invention is shown, including a larger scale display  42  which also includes the indication “lb”, indicating pounds in the illustrated example. Of course when the button  44  is depressed, the display switches to show “Kg”. Bag  410  also includes a clock  443 . 
         [0048]    Still yet another embodiment of a bag  510  constructed in accordance with the invention is illustrated in  FIG. 17 . Here, the scale readout  542  extends into the compartment of the luggage and is, optionally, secured to the bag frame contained within the bag as illustrated. In this embodiment, all of the mechanics of the bag are contained within the fabric of the bag body. 
         [0049]    While illustrative embodiments of the invention have been described, it is noted that various modifications will be apparent to those of ordinary skill in the art in view of the above description and drawings. Such modifications are within the scope of the invention which is limited and defined only by the following claims.