Patent Publication Number: US-10779623-B2

Title: Self-stabilized rollable luggage assembly and corresponding assembly method

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application is a continuation of U.S. patent application Ser. No. 15/451,342 filed on Mar. 6, 2017, which is a continuation in part of U.S. patent application Ser. No. 14/599,961 filed on Jan. 9, 2015 and issued as U.S. Pat. No. 9,585,448, which is a continuation of U.S. patent application Ser. No. 12/348,857 filed on Jul. 8, 2010 and issued as U.S. Pat. No. 8,936,140, which claims priority to PCT Patent Application Serial Number PCT/US09/65414 filed on Nov. 20, 2009, all of which are included herein in their respective entirety, by this reference thereto. 
    
    
     BACKGROUND 
     Some conventional pieces of luggage, such as carry-on bags and rolling duffel bags, may have rollers on the bottom to make the bags easier for travelers to transport. However, travelers often need to transport two or more wheeled pieces of luggage simultaneously. If a traveler needs to transport two wheeled pieces of luggage, both hands are typically required. Consequently, while transporting two or more large, heavy pieces of luggage, the traveler may find it difficult or impossible to do other things, such as answering a cellular telephone call, retrieving cash or keys from a pocket or purse, holding the hand of a small child, etc. Should the traveler happen to remove their hand from the handle holding the first piece of luggage, frequently, all of the luggage on it or connected to it, will fall over. 
     Furthermore, in many situations, travelers find it difficult to maneuver multiple pieces of luggage simultaneously. For instance, it can be difficult to safely transport two large pieces up or down a step or escalator, or to transport both pieces through a narrow opening. Such maneuvers may be particularly difficult when the traveler is small and one or both of the pieces of luggage are large and heavy. When more than two pieces need to be transported, these kinds of difficulties may be multiplied. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The accompanying drawings, which are incorporated herein and form a part of the specification, illustrate some, but not the only or exclusive, examples of embodiments and/or features. It is intended that the embodiments and figures disclosed herein are to be considered illustrative of the luggage system herein, rather than limiting. 
       Various features and advantages of the present self-stabilizing luggage assembly invention will become apparent from the appended claims, the following detailed description of one or more example embodiments, and the corresponding figures, in which: 
         FIG. 1  shows an embodiment of a self-stabilized rollable luggage assembly showing two unequal sized pieces of luggage engaged in a luggage train with the smaller piece of luggage in the lead. 
         FIG. 2  depicts a perspective view of a piece of luggage referred to as a carry-on bag. 
         FIG. 3  shows a perspective view of a piece of luggage referred to as a rolling duffel bag. 
         FIG. 4  depicts a perspective view of a piece of luggage referred to as a shoulder bag. 
         FIGS. 5-8  show side views of the components depicted in  FIGS. 2-4 , illustrating a device and method for creating a self-stabilized luggage assembly or luggage train, according to an example embodiment of the present invention. 
         FIG. 9  depicts a top view of the carry-on bag and the rolling duffel bag from  FIG. 7 . 
         FIG. 10  depicts a rear view of a carry-on bag and a front view of a rolling duffel bag, according to another embodiment of the present invention. 
         FIGS. 11-13  show side views of the carry-on and rolling duffel bags of  FIG. 10 , in different stages of another example embodiment of a method for creating a luggage train between two unequal sized pieces of luggage. 
         FIGS. 14-17  show side views of another embodiment of carry-on and rolling duffel in different stages of another method for creating a luggage train where a smaller piece of luggage is operatively engaged in the lead of a larger piece of luggage. 
         FIG. 18  shows a top view of the carry-on coupled to the rolling duffel in  FIG. 17 . 
         FIG. 19  shows another mode of the self-stabilizing luggage configured as a suitcase or the like, having a deployable connecting strap, shown out of sight and stored in a closed pocket, where the two pieces of luggage may be equal in size or unequal in size. 
         FIG. 20  shows the mode of self-stabilizing luggage of  FIG. 19 , with the user-adjustable strap, deployed from storage in the closeable pocket and ready for engagement to form a luggage train. 
         FIG. 21  depicts the user adjusting the length of the adjustable deployable strap, which engages an adjacent piece of luggage in a self-stabilized train, and which allows for adjustment of the lie angle of the engaged luggage pieces as well as the tilt for taller or shorter users. 
         FIG. 22  shows the deployable strap being locked into an adjusted length, to achieve the lie angle and tilt determined by the user whether used on equal sized or unequal sized adjacent pieces of luggage. 
         FIG. 23  shows an overhead view the adjustment of strap length of  FIG. 21  in the formation of a self-stabilized luggage train of adjacent pieces of luggage. 
         FIG. 24  depicts an overhead view of the self-stabilized luggage as in  FIG. 22 , where the user locks the buckle or connector to fix the length of the deployable strap to achieve the desired lie angle and tilt of the handle during subsequent use on either equal sized or unequal sized pieces of luggage. 
         FIG. 25  shows that the self-stabilized luggage assembly can be adjusted for a tilt angle “A” by adjusting the strap length. 
         FIG. 26  depicts the change in height “H” of the handle from the floor, which may be accomplished by adjusting the length of the strap in its engagement between first and second suitcases while still maintaining a self-stabilized luggage train. 
         FIG. 27  shows the engagement of suitcases of substantially equal height to form the self-stabilized luggage train of  FIG. 28 , which can only be accomplished with the adjustable strap mode of the invention herein. 
         FIG. 28  shows the two suitcases of substantially equal size, engaged and forming a self-stabilized luggage train which can be adjusted for angle as well as handle height above the ground, by adjusting the length of the strap. 
     
    
    
     DETAILED DESCRIPTION 
     In this description, the directional prepositions of up, upwardly, down, downwardly, front, back, top, upper, bottom, lower, left, right and other such terms refer to the device as it is oriented and appears in the drawings and are used for convenience only; they are not intended to be limiting or to imply that the device has to be used or positioned in any particular orientation. 
     Now referring to drawings in  FIGS. 1-28 , wherein similar components are identified by like reference numerals,  FIG. 1  depicts an example embodiment of such a luggage assembly  100  including carry-on bag  102  connected to a trailing bag  104 , and a third bag  106 . Moreover, the bags  102 ,  104 ,  106  are connected in a way that allows a majority of the weight of the assembly  100  to rest on the wheels of carry-on bag  102  and trailing bag  104 . 
     Assembly  100  is self-stabilized when in motion and when stationary, and in particular, a traveler does not need to hold handle  236  for the assembly  100  in a frictional contact  124 , to remain upright or in an inclined position whether or not assembly  100  is in motion. These and other characteristics of luggage assembly  100  provide for excellent stability and maneuverability. Additional details concerning the components and steps used for creating a rollable luggage assembly  100 , as well as various operating characteristics of luggage assembly  100 , are provided below. 
       FIG. 2  depicts a perspective view of an embodiment of a piece of luggage referred to as a carry-on bag  102 . As illustrated, carry-on bag  102  has a front  224 , a back  222 , a top  226 , a bottom  228 , a left side  230 , and a right side  232 . As described in greater detail below, in some embodiments, carry-on bag  102  serves as the foundation for an assembly of bags that can easily be transported, maneuvered, and parked. 
     For purposes of this disclosure, carry-on bag  102  may be referred to as a first bag, a base bag, or a leading bag  102 . In one embodiment, the dimensions of first bag  102  are approximately 23 inches high, 12 inches wide, and 10 inches deep. In other embodiments, other types and/or sizes of bags may be used as the first bag or base bag. 
     In the embodiment of  FIG. 2 , the top of first bag  102  features a soft handle  234 . Left side  230  can also features a soft handle. First bag  102  also features a substantially rigid, yet extendable handle  236  that includes two extendable, rigid upright members  240 , and a substantially rigid grip member  238  that spans the top of upright members  240 . In the embodiment of  FIG. 1 , handle  236  is situated at the back of bag  102 , and is centered longitudinally between the left and right sides. 
     First bag  102  can also have a pair of wheels  242 , with one wheel situated at the back left corner of the bottom of the bag  102 , and the other wheel situated at the back right corner of the bottom of the bag  102 . One or more feet  244  may also be provided at or near the front edge of the bottom of first bag  102 , to provide stability and prevent movement when first bag  102  is parked in an upright position with the weight resting on feet  244  and wheels  242 . 
       FIG. 3  depicts a perspective view of an embodiment of a piece of luggage known as rolling duffel bag  104 . As illustrated, rolling duffel bag  104  has a front  304 , a back  302 , a top  306 , a bottom  308 , a left side  310 , and a right side  312 . 
     In some embodiments, rolling duffel bag  104  is connected to first bag  102  to create a luggage assembly  100  that can easily be transported, maneuvered, and parked. Accordingly, for purposes of this disclosure, rolling duffel bag  104  may be referred to as a second bag or a trailing bag  104 . In at least one embodiment, the trailing bag  104  is larger than the leading bag. In one embodiment, the dimensions of second bag  104  are approximately 28.5 inches high, 13.5 inches wide, and 11.5 inches deep. 
     In another embodiment, the dimensions of the second bag are approximately 33 inches high, 16 inches wide, and 13 inches deep. In another embodiment, the second bag may be greater than 47 inches high. In other embodiments, other types and/or sizes of bags may be used as the second bag or trailing bag  104 . For example, the trailing bag  104  may be the same size as, or smaller than, the leading bag  102 , with attachment means  604  ( FIG. 6 ) dimensioned accordingly (e.g., a longer attachment strap) to provide a suitable weight distribution to stabilize the bags  102 ,  104 . 
     In the embodiment of  FIG. 3 , the top of second bag  104  features a soft handle  314 . Second bag  104  may also feature a rigid, extendable handle  236 , along with a pair of wheels  318  at the back corners of the bottom of the bag, and one or more feet  320  at or near the front edge of the bottom. Feet  320  may provide stability and prevent movement when second bag  104  is parked in an upright position on feet  320  and wheels  318 . 
       FIG. 4  depicts a perspective view of an embodiment of piece of luggage known as shoulder bag  106 . As illustrated, shoulder bag  106  has a back  402 , a front  404 , and a strap  406 . As described in greater detail below, in one embodiment, shoulder bag  106  may be connected to first bag  102  along with second bag  104  to create an assembly of bags that can easily be transported, maneuvered, and parked. Accordingly, for purposes of this disclosure, shoulder bag  106  may be referred to as a top bag or a third bag  106 . 
     In the embodiment of  FIG. 4 , strap  406  is dimensioned to snugly receive handle  236 . Thus, strap  406  may be slid down handle  236  until third bag  106  rests on top of first bag  102 , and strap  406  will thereafter prevent top bag  106  from being dislodged. In other embodiments, other types and/or sizes of bags may be used as the third bag  106  (e.g., a laptop bag, a purse, a carry-all bag, a gear bag). Typically the third bag  106  can be sized to meet airline requirements for carry-on bags. For instance, the third bag  106  could be small enough to fit under a typical airline seat. In other embodiments, the third bag  106  may be omitted. 
       FIGS. 5-8  depict side views of the components depicted in  FIGS. 2-4 . In addition,  FIGS. 5-8  illustrate an embodiment of a method for creating luggage assembly  100  ( FIG. 1 ). 
       FIG. 5  depicts first bag  102 , second bag  104 , and third bag  106  resting on the floor, each in an upright position, as they might be situated, for instance, after a traveler has retrieved second bag  104  from a baggage carousel. The process for attaching the bags together in a manner to create a stable luggage assembly  100  may begin with the bags in this position. The traveler may then separate handle  314  into two separate members. 
     As shown in  FIG. 6 , handle  314  may include a main handle strap  602  and a reinforcement handle strap  604 . A sleeve with snaps, or any other temporary connection means, may be used to keep main handle strap  602  and reinforcement handle strap  604  connected when second bag  104  is being used alone. When desired, however, the traveler may release the temporary connection means, to allow the traveler to separate reinforcement handle strap  604  from main handle strap  602 , as shown by arrow  606  in  FIG. 6 . 
     In one embodiment, two ends of main handle strap  602  are connected to the top of second bag  104 , at two points at or near the left and right edges of the top  306  of bag  104 , while two ends of reinforcement handle strap  604  are connected to the upper portion  322  (e.g., the upper third) of the back of second bag  104 . For instance, the two ends of reinforcement handle strap  604  may be connected at two points at or near the top edge of the back  302 . In one embodiment, the two attachment points for reinforcement handle strap  604  are approximately equal distances from the longitudinal center of second bag  104 , and the two attachment points are situated at least as far apart from each other as are the upright members  240  of handle  236  of first bag  102 . Other embodiments may use other configurations of uprights, handles, and/or straps. 
     Once the traveler has separated reinforcement handle strap  604  from main handle strap  602 , the traveler lifts reinforcement handle strap  604  over grip  238  of handle  236 , as shown by arrow  608 . Extendable handle  236  may be retracted to make this operation easier. 
     As shown in  FIG. 7 , the traveler then slides reinforcement handle strap  604  down handle  236 , and/or extends handle  236  up through reinforcement handle strap  604 , to couple second bag  104  to first bag  102 . Accordingly, reinforcement handle strap  604  and handle  236  may serve as, and may be referred to as, attachment members. Similarly, reinforcement handle strap  604  may also be referred to as an attachment strap  604 . 
       FIG. 9  depicts a top view of the configuration of first bag  102  and second bag  104  shown in  FIG. 7  with the second bag  104  attached to the first bag  102 , but without third bag  10  As illustrated, once the traveler has attached second bag  104  to first bag  102  with reinforcement handle strap  604 , reinforcement handle strap  604  may have three segments, namely, a first segment  604 A and a third segment  604 C, each of which extends from second bag  104  around handle  236 , and an intermediate second segment  604 B, which spans handle  236 . In one embodiment, first segment  604 A and third segment  604 C are approximately the same length  902 , and that length  902  is approximately twice the length  904  of the segment that spans handle  236 . 
     For instance, segments  604 A and  604 C may be approximately 10 inches long, and segment  604 B may be approximately six inches long. The distance between the attachment points on second bag  104  for segments  604 A and  604 C may also be approximately six inches  904  The relatively wide intermediate segment, in conjunction with the relatively wide attachment points on second bag  104 , may provide increased stability for the luggage assembly  100  by helping to prevent the left or right side of second bag  104  from lifting away from first bag  102 . 
     Other dimensions and/or proportions may be used in other embodiments. For instance, the rigid handle  236  on the leading bag  102  could be wider than six inches or less than six inches (e.g., a single post), and the attachment strap could be longer or shorter, correspondingly. A rollable luggage assembly  100  may thus use an attachment strap  604  that is proportionate in length to the distance from the trailing bag  104  to and around the handle  236  to prevent the trailing bag  104  from sliding too far down the leading bag  102 . 
     Referring again to  FIG. 7 , the traveler may also attach third bag  106  to the assembly  100  by sliding strap  406  down handle  236  to rest third bag  106  on top of first bag  102  and reinforcement handle strap  604 . The added weight of third bag  106  on reinforcement handle strap  604  may provide increased stability for luggage assembly  100 . The added weight of third bag  106  may also contribute to the overall stability of luggage assembly  100 , depending on the weight and angle of the other bags. For instance, if the trailing bag  104  was very heavy and the leading bag  102  was very light, a third bag  106  on top of the leading bag  102  could provide a beneficial force downward in front of the wheels  242  of the first bag  102  to prevent the first bag  102  from reverting to the upright position. 
     Furthermore, as indicated above, many different kinds of objects could be used as the third bag  106 . For instance, a box or package may be placed on top of first bag  102  to serve as the third bag  106 , and the rollable luggage assembly  100  may also serve as a self-stabilized dolly for transporting that box or package. Third bag  106  may or may not include strap  406 . 
     When handle  236  has been extended up through reinforcement handle strap  604 , the assembly may take on substantially the configuration shown in  FIG. 7 , with first bag  102  in an upright position and second bag  104  leaning against first bag  102 . In this configuration, most of the weight of second bag  104  may rest behind wheels  318 . The force of gravity may therefore pull reinforcement handle strap  604  firmly against the front of upright members  240  and the top of first bag  102 . Reinforcement handle strap  604  is configured to retain second bag  104  in contact with at least a portion of first bag  102 , and may prevent second bag  104  from sliding down or moving away from the front of first bag  102  while luggage assembly  100  is in motion. In one embodiment, reinforcement handle strap  604  keeps the top back edge of second bag  104  substantially adjacent to the top back edge of first bag  102 . 
     In other embodiments, the attachment member may allow the second bag  104  to slide a short distance further down the back of the first bag  102 . However, it is generally preferable to keep to top of the second bag  104  within a certain distance, such as, for example, approximately two inches of the top of the first bag  102 , to provide weight distribution advantages such as those described below. 
     Referring again to  FIG. 8 , luggage assembly  100  is depicted in an inclined configuration. Specifically, (a) reinforcement handle strap  604  of second bag  104  is wrapped around handle  236  of first bag  102 , (b) third bag  106  is resting on top of first bag  102  and reinforcement handle strap  604 , with strap  406  receiving handle  236 , (c) both first bag  102  and second bag  104  are inclined at an angle on their wheels  242 ,  318  with the feet  244 ,  320  elevated from the floor, and (d) at least a portion of the back of second bag  104  is in contact with at least a portion of the front of first bag  102 . In embodiments that do not include third bag  106 , the assembly  100  may be considered fully assembled when in the preceding configuration, but without third bag  106 . 
     Reinforcement handle strap  604  is dimensioned to engage handle  236  when second bag  104  is situated next to first bag  102 . Reinforcement handle strap  604  is typically flexible but substantially inelastic, but strap  604  can also have some elasticity. Consequently, when first bag  102  is tilted forward from an upright position into the inclined position shown in  FIG. 8 , reinforcement handle strap  604  substantially prevents second bag  104  from sliding down the front of first bag  102  or moving away from first bag  102  while assembly  100  is in motion and stationary. For instance, the relative positions of the tops of first bag  102  and second bag  104  may change by less than five percent of the height of first bag  102  (e.g., approximately one inch) in the embodiment of  FIG. 8 . In other embodiments, depending on the size and weight of the trailing bag  104 , the attachment means  604  may provide for a larger or smaller change in position to maintain balance. 
     When first bag  102  and second bag  104  are tilted or inclined as shown in  FIG. 8 , most of the weight of second bag  104  sits in front of wheels  318 . Consequently, the weight of second bag  104  keeps second bag  104  firmly pressed against first bag  102 , and prevents second bag  104  from accidentally reverting to the upright position. Furthermore, a sufficient portion of the weight of the assembly  100  typically rests in front of wheels  242  to prevent first bag  102  from reverting to the upright position. As described in greater detail below, this tendency for the bags to stay in inclined or pitched forward positions may be referred to as internal pitch stability or self-stabilizing. 
     In one embodiment, the contact area where the front  222  of first bag  102  contacts the back  302  of second bag  104  covers more than seventy-five percent of the front  224  of first bag  102  and more than sixty percent of the back  302  of second bag  104 . This contact area helps to keep second bag  104  from shifting relative to first bag  102 . 
     Accordingly, when the bags  102 ,  104  are substantially fully loaded and are configured in the position depicted in  FIG. 8 , luggage assembly  100  tends to remain in that position, with some of the weight of the assembly supported by wheels  242 , and the rest supported by wheels  318 . Consequently, once the assembly has been completed, the traveler need not expend any effort to keep the assembly together and properly positioned. The traveler may also easily move assembly  100  with a single hand. Furthermore, whether stationary or in motion, and whether tilted or not, the assembly  100  is completely self-stabilized and may continue on its established course with no hands or other external support. 
     In addition, in some embodiments, when in the completed and ready-to-roll position depicted in  FIG. 8 , much of the weight of assembly  100  can rest in front of wheels  242 . For instance, depending upon the weight of each bag, and the distribution of weight in each bag, approximately twenty to forty percent of the weight of the assembly  100  might rest in front of the wheels  242  of the first bag  102 . 
     Furthermore, handle  236  provides significant leverage, and reinforcement handle strap  604  prevents second bag  104  from shifting from its position on first bag  102 . Consequently, it is typically easy to press down on handle  236  and lift wheels  318  completely off of the ground. For example, if the weight is well distributed within the bags, it may be easy for a 100 pound traveler to perform this operation with one hand on a luggage assembly  100  weighing in excess of 100 pounds. Additionally, the further down the traveler pushes handle  236 , the more weight shifts in front of wheels  242 . The traveler may therefore easily balance the whole assembly  100  on wheels  242  similar to maneuvering baby strollers over steps, escalators, etc. Accordingly, with the assembly  100  balanced on the wheels  242  of the leading bag  102 , the traveler may find it very easy to maneuver the entire assembly  100  around turns, over steps, up and down escalators, and through various other obstacles which would be more difficult to handle with two or more pieces of conventional luggage, one in each hand. Further, since assembly  100  is no wider than the widest bag in the assembly  100 , it may be easy to maneuver assembly  100  through crowded or narrow openings or passages. 
     When the traveler does not want assembly  100  to move, the traveler may simply return first bag  102  to the upright position, so that feet  244  contact the ground and bear some of the weight of assembly  100 . 
     Also, as indicated above, the way reinforcement handle strap  604  connects the first and second bags together helps to keep the left and right sides of second bag  104  from lifting or moving away from first bag  102  when assembly  100  is in the rollable configuration. In other words, reinforcement handle strap  604  prevents second bag  104  from spinning or rotating along its longitudinal axis, relative to first bag  102 . For example, in the embodiment of  FIG. 8 , reinforcement handle strap  604  prevents second bag  104  from rolling more than five degrees, relative to first bag  102 , when first bag  102  and second bag  104  are substantially fully packed. Another embodiment may allow the first bag to roll up to thirty degrees, relative to the first bag. This type of stability for assembly  100  may be referred to as internal roll stability. By contrast, the resistance of the entire assembly  100  from rotating about its longitudinal axis may be determined largely by the distance between the wheels on the bottom of first bag  102 , and that type of stability may be referred to as external roll stability. 
     Assembly  100  also exhibits good internal and external pitch stability. For purposes of this disclosure, internal pitch stability refers to the tendency of both bags  102 ,  104  to retain the same angle of inclination, relative to each other, when the first and second bags  102 ,  104  are in the rollable configuration. In other words, the attachment members, the weight distribution, and other features work to resist forces which might otherwise cause one bag to lean up or down, relative to the other bag, even when a traveler is not holding onto handle  236  or any other part of the first bag  102  or second bag  104 . Good internal pitch stability is one of the attributes that makes it easy to lift wheels  318  by pressing down on handle  236 . External pitch stability refers to the tendency of the complete assembly  100  to keep all four wheels  242 ,  318  on the ground. 
     Furthermore, assembly  100  exhibits good internal and external yaw stability. For purposes of this disclosure, internal yaw stability refers to the tendency for the first and second bags  102 ,  104  to keep the same relative alignment for their longitudinal axes. In other words, considering the contact patch  802  between the first and second bags  102 ,  104 , the front  304  of the second bag  104  tends not to rotate relative to the back  222  of the first bag  102 . External yaw stability refers to the tendency for assembly  100  to track straight when it is rolling on all four wheels. The characteristics of pitch, roll, and yaw stability exhibited by assembly  100  contribute to assembly  100  being self-stabilized when in motion and when stationary, whether bags  102 ,  104  are tilted or not. Note that components of assembly  100  can be coupled using alternative attachment means such as one or more Velcro straps, straps with snaps or zippers, and straps on the trailing bag  104  that disconnect and reconnect with corresponding straps on the leading bag  102 . The straps may or may not be adjustable to provide suitable balance/leverage for bags packed with different weights, and that may serve as reinforcement straps when not being used to form a luggage assembly  100 . 
       FIG. 10  depicts a rear view of another embodiment of carry-on bag  1040  and a front view of another embodiment of rolling duffel bag  1050 . Carry-on bag  1040  may also be referred to as a leading bag or a first bag  1040 . Rolling duffel bag  1050  may also be referred to as a trailing bag or a second bag  1050 . As shown, a mating strap  1042  is affixed to the front of first bag  1040 , and a corresponding mating hook  1052  is attached to the back of second bag  1050 . Mating strap  1042  may be made of textile, leather, plastic, or any other suitable material. Mating hook  1052  may be made of metal, plastic, or any other suitable material. 
     Mating strap  1042  is dimensioned to receive mating hook  1052 . For instance, the top  1054  of mating hook  1052  may be approximately 4 inches wide, and the opening  1044  between mating strap  1042  and the back of first bag  1040  may be substantially the same width as top  1054 . The relatively wide mating hook  1052 , when engaged by mating strap  1042  may tend to prevent the left and right sides of second bag  1050  from moving or lifting away from first bag  1040 . Opening  1044  may also be referred to as a mating slot  1044 . Other dimensions may be used in other embodiments. 
       FIG. 11  depicts a side view of bags  1040  and  1050  in a first position. To begin connecting first bag  1040  and second bag  1050  into a stable luggage assembly  1000  ( FIGS. 12 and 13 ) or luggage train, the traveler may lean first bag  1040  and second bag  1050  slightly backwards, as shown. The traveler may then insert the tip  1056  of mating hook  1052  into mating slot  1044 . 
       FIG. 12  depicts a side view of bags  1040  and  1050  upright in luggage assembly  1000 . As depicted, when first bag  1040  and second bag  1050  are returned to upright positions, mating hook  1052  may keep the bags together. Accordingly, mating hook  1052  and mating strap  1042  may be referred to as attachment members. 
       FIG. 13  depicts a side view of bags  1040  and  1050  tilted in a luggage assembly  1000 . As first bag  1040  is tilted away from second bag  1050 , mating hook  1052  slides down into mating slot  1044  until the inside top  1054  of mating hook  1052  engages mating strap  1042 . In a tilted orientation, at least some the weight of second bag  1050  may rest in front of the wheels  1058  of second bag  1050 , so that gravity presses the back of second bag  1050  against the front of first bag  1040 . Consequently, similar to the embodiment of  FIG. 8 , the luggage assembly  1000  may be self-stabilized in this configuration, and may be easily rolled with one hand. The handle of first bag  1040  may also be used to lift wheels  1058  off of the ground, thereby allowing for good maneuverability, substantially as described above with regard to  FIGS. 2-9 . 
       FIGS. 14-17  show side views of another embodiment of carry-on bag  1402  and rolling duffel bag  1404  in different stages of another method for creating a luggage assembly  1400 . In the embodiment shown, carry-on bag  1402  and rolling duffel bag  1404  include two or more respective sets of straps  1406 ,  1410  with releasable connectors  1408 ,  1412  coupled at an intermediate portion along straps  1406 ,  1410 . Connectors  1408 ,  1412  are configured to be released and re coupled to a receiving connector portion either on the same bag or on the adjacent bag. That is, one end of straps  1406 ,  1410  are attached to the top back of bags straps  1406 ,  1410  are attached to the front top of bags  1402 ,  1404  and another intermediate end of straps  1406 ,  1410  terminates with another portion of connector  1408 ,  1412 . Straps  1406 ,  1410  can span from front to back across the tops of respective bags  1402 ,  1404  when portions of connectors  1408 ,  1412  are coupled. Additionally, portions of connectors  1412  on duffel bag  1404  can couple to a compatible portion of connector  1408  on carry-on bag  1402  and vice versa. Straps  1406 ,  1410  and connectors  1408 ,  1412  may also be referred to collectively herein as attachment members. 
       FIG. 15  shows connectors  1408 ,  1412  decoupled, leaving four intermediate ends of straps  1406 ,  1410  loose. In  FIG. 16 , the portions of connectors  1412  on straps  1410  attached to the top back of duffel bag  1404  are coupled to portions of connectors  1408  on straps  1406  that are attached to the top back of the carry-on bag  1402 . The length of straps  1406 ,  1410  may be adjusted to draw carry-on bag  1402  and duffel bag  1404  closer together once the connectors  1408 / 1412  are coupled. 
       FIG. 17  shows a side view of luggage assembly  1400  with bags  1402 ,  1404  in a tilted position. With connectors  1408 ,  1412  coupled, bag  1404  leans in the direction of bag  1402  as bag  1402  is tilted. In this orientation, at least some the weight of bag  1404  may rest over and/or in front of the wheels  1414  of bag  1402 , so that gravity presses the back of bag  1404  against the front of bag  1402 . Consequently, similar to the embodiment of  FIG. 8 , the luggage assembly  1400  may be self-stabilized in this configuration, and may be easily rolled with one hand. The handle of first bag  1402  may also be used to lift wheels  1416  off of the ground, thereby allowing for good maneuverability, substantially as described above with regard to  FIGS. 2-9 . 
     As shown in  FIGS. 19-28  the self-stabilizing luggage assembly  100  system herein, is provided with enhanced utility when provided with an adjustable length deployable strap  1502 , which can be stored within a hidden pocket  1504  of the luggage piece  1506  when it is placed in the luggage handling system of an airport. Provision of a deployable and storable adjustable strap  1502  is a particularly preferred mode of the self-stabilizing luggage assembly  100  system herein, because it offers a number of advantages not provided by the other above noted modes of the invention. 
     First, by using a deployable adjustable strap  1502 , which will deploy from the luggage bag  1506  positioned as the trailing bag  1505 , the user can adjust the length of the strap  1502  during engagement of any sized adjacent luggage bag  1508  in the laid position ( FIGS. 25-28 ), to form a self-supporting luggage assembly  100  at a desired engaged angle “A” of the engaged luggage pieces  1506  and  1508 , which remains in balance and maintains the handle  1510  at the desired angle “A” and at a height “H” from the floor and in balance. Only using an adjustable strap  1502  is such a balanced engagement self-supporting luggage assembly  100  achievable with equal sized luggage pieces in the trailing as well as leading position, regardless of the load that they are carrying. 
     Further, by adjusting the length of the deployable adjustable strap  1502 , and the resulting encirclement of the handle support  1512  of the adjacent leading luggage piece  1508 , the user can set the elevation or height “H” of the retractable handle  1510 , above the support surface on which the luggage train formed by the strap-engaged luggage pieces. This allows the user to form a balanced self-stabilized luggage assembly  100 , with the handle  1510  of the adjacent leading luggage piece  1508 , at a height “H” that is comfortable for the user to grip. This is very important since the height and arm length of users varies widely. Consequently, the ability to adjust the operative height of the handle “H” of the balanced luggage assembly  100 , even where the lead luggage piece  1508  is equal to the trailing luggage piece  1506  in height, provides significant utility not found in other modes of the device and system herein. 
     Through this provision of an adjustable length storeable strap  1502 , a user is provided with the ability to operatively engage two adjacent pieces of luggage of substantially equal size into a luggage assembly  100 . By substantially equal is meant that the height the smaller suitcase in the pairing forming the luggage assembly  100  is equal to, or 95 percent of the height of the larger luggage piece in the pairing. This is a significant increase in utility form the other modes of the device herein, since previous modes require that one piece of luggage in the formed self-stabilized luggage train, be smaller than the other and unequal. 
       FIG. 19  shows another mode of the self-stabilizing luggage herein, which features a luggage piece  1606 , which has a deployable adjustable connecting strap  1502 . As depicted the strap  1502  is stored within a pocket  1504  which has a closure  1514  thereon such as a zipper closure  1514  or one formed of hook and loop fabric, buttons, snaps, magnets, or another closure  1514  which will secure the opening to the pocket  1504  closed, and the adjustable strap  1502  secure within. 
       FIG. 20  depicts the mode of self-stabilizing luggage of  FIG. 19 , with the user-adjustable strap  1502 , deployed through the opening providing access to the closeable pocket  1504 . 
     Shown in  FIG. 21  is an example of a user adjusting the length of the deployable adjustable strap  1502 , during engagement around the handle support  1512  of the adjacent luggage piece  1508  which is positioned in the lead of the formed self-stabilized assembly  100 . The distal end of the strap  1502  is pulled through a securing connection shown as a buckle  1518 , to a connection position, to adjust the formed loop  1520  which will encircle the handle support  1512  of the adjacent luggage piece  1508  positioned in the lead of the formed assembly  100 . As noted this adjustment of the length of the strap  1502  and the loop  1520  encircling the handle support  1512 , to any of a plurality of such connection positions on the strap  1502 , allows the user to adjust the lie angle “A” ( FIG. 25 ) of the assembly  100  as well as the height “H” of the handle  1510  above the floor during use. For users who may be shorter or taller this is an especially desired utility provided by the system in this mode. 
     Shown in  FIG. 22 , the deployable adjustable strap  1502  can be locked into an adjusted length using the securing connector such as the buckle or latch, to hold the desired length achieving the desired lie angle “A” and handle height “H” desired by a user. 
     Depicted in  FIG. 23  there can be seen an overhead view showing the adjustment of the length of the adjustable strap  1502 . As noted this is done by the user to form a self-stabilized luggage assembly  100  of a leading luggage piece  1508  with a trailing luggage piece  1502  having the adjustable strap  1502  operatively connected thereto. As noted the leading and trailing luggage pieces may be equal in size and still engaged to a self-stabilizing luggage assembly  100 . 
     Shown in  FIG. 24  is an overhead view of the self-stabilized luggage assembly  100  as in  FIG. 22 , after adjustment of the handle height “H” and lie angle “A” by the user which is accomplished by adjusting the size of the loop  1520 . Thereafter as shown, the user locks the adjustable strap  1502  to maintain the desired loop  1520  size, using the securing connector such as a buckle  1518 , to fix the length of the deployable strap  1502  and loop  1520  size. 
     This adjusted engagement to form a luggage assembly  100  with the desired angle “A” is shown in  FIG. 25 . The user will adjust the length of the strap  1502  and the size of the loop  1520  to achieve the desired tilt angle “A” in the formed luggage assembly  100 . As noted, the user can also adjust the length of the strap  1502  and lock it as shown in  FIG. 26  once a desired height of the handle “H” above the ground or floor is achieved by their formed self-supporting luggage assembly  100 . 
     Finally, as shown in  FIG. 27  and  FIG. 28 , the engagement of a luggage piece  1504  as the trailing bag  1505  with the leading bag adjacent luggage piece  1508 , can be an engagement to form an assembly  100  between two luggage pieces of equal height or substantially equal height, to form the self-stabilized luggage assembly  100  of  FIG. 28 . As noted, the employment of a luggage piece  1506  which a deployable adjustable strap  1502  which allows for adjustment of the circumference of the formed loop  1520  is the only mode of the device and system herein which allows for the trailing luggage piece to be equal or substantially equal in height to the leading adjacent luggage piece  1506  to which it engages to form the assembly  100 . Further, even where the luggage pieces are equal in size, the user may still adjust the length of the strap  1502  to change the size of the loop  1520 , to thereby adjust the lie angel “A” and handle elevation or height “H” above the support surface. 
     Thus, as has been described, embodiments of a rollable luggage assembly may be made of two or more luggage pieces using suitable attachment means to keep the luggage assembly self-stabilized when stationary and when rolling. The size and weight of each luggage piece, when fully loaded, as well as the configuration of the attachment means, may serve to keep the pieces balanced on the wheels of the assembly. 
     In light of the principles and example embodiments described and illustrated herein, it will be recognized that the illustrated embodiments can be modified in arrangement and detail without departing from such principles. For instance, alternative embodiments may use approaches like those described above to create luggage assemblies with other types and sizes of bags, other types of attachment members, etc. For instance, the trailing bag may be shaped substantially like a rectangular cuboid in some embodiments. Also, second trailing bag may be attached to the first trailing bag to form a rolling luggage assembly with six wheels on the ground. Likewise, more than two trailing bags could be used. 
     Also, the foregoing discussion has focused on particular embodiments, but other configurations are contemplated. In particular, even though expressions such as “in one embodiment,” “in another embodiment,” or the like are used herein, these phrases are meant to generally reference embodiment possibilities, and are not intended to limit the invention to particular embodiment configurations. As used herein, these terms may reference the same or different embodiments that are combinable into other embodiments. 
     Similarly, although example processes have been described with regard to particular operations performed in a particular sequence, numerous modifications could be applied to those processes to derive numerous alternative embodiments of the present invention. For example, alternative embodiments may include processes that use fewer than all of the disclosed operations, processes that use additional operations, and processes in which the individual operations disclosed herein are combined, subdivided, rearranged, or otherwise altered. In view of the wide variety of useful permutations that may be readily derived from the example embodiments described herein, this detailed description is intended to be illustrative only, and should not be taken as limiting the scope of the invention. What is claimed as the invention, therefore, are all implementations that come within the scope of the following claims and all equivalents to such implementations.