Patent Publication Number: US-2009218187-A1

Title: Tilted Push-Pull Wheeled Luggage with a Removable Front Swingable Wheel with an Elongated Neck for the Removable Front Swingable Wheel

Description:
BACKGROUND 
     This invention generally relates to luggage. In particular, the invention relates to a novel wheeled luggage that reduces the user&#39;s burden of lifting a portion of the wheeled luggage during transportation. Furthermore, the invention relates to a novel wheeled luggage which utilizes a removable front swingable wheel. 
     Wheeled luggage is a common method of carrying items for shippers and travelers. One common type of wheeled luggage is a “pullman” case. There are several variations of pullman cases. One type of pullman cases has two fixed wheels located in the bottom-rear portion and a pair of luggage legs in the bottom-front portion of the case. This type of pullman case also has a handle or a strap located in the front portion of the case. A user is required to “pull” the case by lifting the front portion of the case and pulling the case forward. The pullman case can either have a solid or flexible casing. One disadvantage of the pullman case is that the user has to lift the front portion of the case with a handle and then pull the case forward, which requires a directly proportional amount of pulling force relative to the weight of the case. Therefore, for pullman cases, increased weight of luggage requires a proportionally increased amount of pulling force from the user. 
     Another common type of pullman case has four wheels at the bottom of the case. They are designed to be pulled like a wagon with a handle or a strap in the front portion of the case. In order to pull the case ergonomically, the handle or the strap of the four-wheeled pullman is diagonally upward from the front portion of the case because a user is typically taller than the case. A Newtonian physics force diagram for the required diagonally-upward force suggests that the user is essentially lifting a portion of the weight of the case (i.e. a vertical vector component from the diagonally upward vector representing the net force). Therefore, heavier pullman cases assert substantial strain on the user&#39;s arm during transportation. As a real-world example, this drawback is apparent to a user in with a heavy pullman-type luggage at a large airport, where the user may be required to roll the luggage across hundreds or thousands of yards. 
     Furthermore, a conventional wheeled luggage which has one or more wheels in front of the rear wheels and a flat surface clearance height at a bottom surface is often inconvenient for a user. The flat surface clearance height typically requires the user to provide a vertical-lift force to a front portion of the conventional wheeled luggage to prevent tip-over and accommodate a smooth movement of the conventional wheeled luggage. 
     Therefore, a novel wheeled luggage which substantially reduces the stress on a user&#39;s arm is highly desirable. Furthermore, a novel wheeled luggage configuration which provide a variable surface clearance height for smoother movement of a wheeled luggage is also highly desirable. 
     SUMMARY 
     Summary and Abstract summarize some aspects of the present invention. Simplifications or omissions may have been made to avoid obscuring the purpose of the Summary or the Abstract. These simplifications or omissions are not intended to limit the scope of the present invention. 
     A wheeled luggage case configured to be pushed and pulled by a user using a handle attached to the wheeled luggage case is disclosed. In one embodiment of the invention, the wheeled luggage case comprises a main luggage body with a higher front ground-clearance height relative to a rear ground-clearance height of the main luggage body, wherein the higher front ground-clearance height is achieved by a triangular neck portion which enables a vertical axis of swinging rotation for one or more removable front swingable wheels to form a perpendicular angle with a flat (i.e. horizontal) surface, and wherein the triangular neck portion contributes to a backward-tilt of the wheeled luggage case; one or more fixed rear wheels located near a rear edge of a lower portion of the main luggage body, wherein each fixed rear wheel stabilizes a straight path movement; and the one or more removable front swingable wheels located in front of the one or more fixed rear wheels in an attached mode, wherein the one or more removable front swingable wheels can be easily attached, detached, and/or re-attached by the user, and wherein the one or more removable front swingable wheels utilize a slide rail, a ball detent, a plurality of Velcro strips, and/or “snap-fit” male and female guides to be attached or detached to the lower portion of the main luggage body by the user. 
     Furthermore, another embodiment of a wheeled luggage case configured to be pushed and pulled by a user using a handle attached to the wheeled luggage case is disclosed. In one embodiment of the invention, the wheeled luggage case comprises a main luggage body with a higher front ground-clearance height relative to a rear ground-clearance height of the main luggage body, wherein the higher front ground-clearance height is achieved by a triangular neck portion which enables a vertical axis of swinging rotation for one or more removable front swingable wheels to form a perpendicular angle with a flat (i.e. horizontal) surface, and wherein the triangular neck portion contributes to a backward-tilt of the wheeled luggage case; one or more fixed rear wheels located near a rear edge of a lower portion of the main luggage body, wherein each fixed rear wheel stabilizes a straight path movement; and the one or more removable front swingable wheels located in front of the one or more fixed rear wheels in an attached mode, wherein the one or more removable front swingable wheels can be easily attached, detached, and/or re-attached by the user by utilizing a first Velcro strip on the lower portion of the main luggage body and a second Velcro strip on a top portion of the one or more removable front swingable wheels. 
     Moreover, an elongated neck for a removable front swingable wheel attachable to a lower front portion of a wheeled luggage is also disclosed. In one embodiment of the invention, the elongated neck comprises a triangular neck portion with a top surface of the triangular neck portion permanently attached or attachable on-demand to a bottom surface of the wheeled luggage, wherein the triangular neck portion enables a vertical axis of swinging rotation for the removable front swingable wheel to form a perpendicular angle with a flat (i.e. horizontal) surface, and wherein the triangular neck portion contributes to a backward-tilt of the wheeled luggage case; and an additional neck portion attached or attachable on-demand to a bottom surface of the triangular neck portion, wherein the additional neck portion is horizontally rotational to enable a “swinging” motion of the swingable wheel and contains a vertical axis of swinging rotation, and wherein the triangular neck portion and the additional neck portion contribute to a backward-tilt of the wheeled luggage case. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  shows a user pushing a wheeled luggage in accordance with one or more embodiments of the invention. 
         FIG. 2  shows a user pulling a wheeled luggage in accordance with one or more embodiments of the invention. 
         FIG. 3  shows a bottom portion of a wheeled luggage in accordance with one or more embodiments of the invention. 
         FIG. 4  shows a bottom portion of a wheeled luggage in accordance with one or more embodiments of the invention. 
         FIG. 5  shows a laid-down side view of a wheeled luggage in accordance with one or more embodiments of the invention. 
         FIG. 6  shows a zoomed-in view of a swingable wheel from a prior art. 
         FIG. 7  shows a zoomed-in view of a swingable wheel with an elongated neck with a triangular neck portion located at a bottom-front portion of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 8  shows a side view of a removable front swingable wheel detached from a wheeled luggage, and a slide rail and a ball detent mechanism on bottom of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 9  shows a side-bottom perspective view of a removable front swingable wheel and a sliding plate in a “snap-in” or a locking position with a slide rail and a ball detent mechanism on a lower surface of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 10  shows a side-bottom perspective view of a removable front swingable wheel configured to snap into an attached position with a slide rail and a ball detent mechanism on bottom of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 11  shows a side view of a removable front swingable wheel with a Velcro surface separated from a wheeled luggage, and a side view of a bottom portion of a wheeled luggage with a Velcro surface, in accordance with one or more embodiments of the invention. 
         FIG. 12  shows a side-bottom perspective view of a removable front swingable wheel with a Velcro surface configured to be attached to a Velcro surface on a bottom portion of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 13  shows a side-bottom perspective view of a removable front swingable wheel with a Velcro surface attached to a Velcro surface on a bottom portion of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 14  shows a side view of a removable front swingable wheel with a snap-fit male guide attached on top of the removable front swingable wheel, and a snap-fit female guide at a bottom portion of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 15  shows a side-bottom perspective view of a removable front swingable wheel with a snap-fit male guide attached on top of the front removable swingable wheel, and a snap-fit female guide at a bottom portion of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 16  shows a side view of a removable front swingable wheel with a snap-fit female guide on the removable front swingable wheel, and a snap-fit male guide at a bottom portion of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 17  shows a side-bottom perspective view of a removable front swingable wheel with a snap-fit female guide on the removable front swingable wheel, and a snap-fit male guide at a bottom portion of a wheeled luggage, in accordance with one or more embodiments of the invention. 
         FIG. 18  shows a side-bottom perspective view of a removable front swingable wheel attached to a bottom portion of a wheeled luggage using snap-fit male and female guides, in accordance with one or more embodiments of the invention. 
     
    
    
     DETAILED DESCRIPTION  
     Specific embodiments of the invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency. 
     In the following detailed description of the present invention, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will become obvious to those skilled in the art that the present invention may be practiced without these specific details. In other instances, well known methods, procedures, and/or components have not been described in detail to avoid unnecessarily obscuring aspects of the present invention. The detailed description is presented largely in terms of procedures, logic blocks, processing, and/or other symbolic representations that directly or indirectly resemble wheeled luggage and its various configurations. These descriptions and representations are the means used by those experienced or skilled in the art to most effectively convey the substance of their work to others skilled in the art. 
     Reference herein to “one embodiment” or “an embodiment” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. Further, the order of blocks in process flowcharts or diagrams representing one or more embodiments of the invention do not inherently indicate any particular order nor imply any limitations in the invention. 
     In general, embodiments of the invention relate to an apparatus for carrying items in a luggage. More specifically, embodiments of the invention relate to a wheeled luggage which can be used for a “push mode” and a “pull mode” by the user using a handle attached to the wheeled luggage. 
     Furthermore, embodiments of the invention enable the user to move the wheeled luggage in a push mode with significantly less effort than in a pull mode. More specifically, the invention alleviates the user from lifting a portion of the weight of the wheeled luggage by tilting the luggage backward (i.e. towards the user) and incorporating one or more “swingable” front wheels in lower front portion of the luggage. 
     In one embodiment of the invention, each swingable wheel is configured to rotate horizontally around a neck of the swingable wheel attached to a bottom portion of the wheeled luggage. The tilting of the wheeled luggage is achieved by using an elongated neck for each swingable wheel, thereby creating a higher front ground clearance relative to a lower rear ground clearance provided by fixed rear wheels for the wheeled luggage. 
     In one embodiment of the invention, an elongated neck ( 702 ,  703 ) of a swingable wheel ( 704 ) in  FIG. 7  includes a triangular neck portion ( 702 ) which enables a vertical axis ( 707 ,  708 ) of swinging rotation (e.g.  302 ,  402 ) for the swingable wheel ( 704 ) to form a perpendicular angle (i.e. angle between  706  and  707 ) with a flat surface, as shown by an illustrative horizontal arrow ( 706 ,  709 ) and the vertical axis ( 707 ,  708 ) of swinging rotation (e.g.  302 ,  402 ) for the swingable wheel ( 704 ) in  FIG. 7 . Without the triangular neck portion ( 702 ) of  FIG. 7 , an axis of rotation ( 607 ,  610 ) for an elongated neck ( 603 ) of  FIG. 6  forms a perpendicular angle with a bottom surface of the wheeled luggage (i.e. angle between  610  and  611 ) and undesirably forms an obtuse angle (i.e. angle between  609  and  607 ) and an acute angle (i.e. angle between  606  and  607 ) with the flat surface, as shown in  FIG. 6 . A non-perpendicular angle between the axis of rotation ( 607 ,  610 ) of the swingable wheel and the flat surface ( 600 ), as illustrated in  FIG. 6 , hampers the user from pushing the wheeled luggage efficiently because the horizontal “swing” or directional movements of the swingable wheel is hampered by uneven gravitational pressure to the swingable wheel. In contrast, with the triangular neck portion ( 702 ) as illustrated in  FIG. 7 , gravitational pressure is generally more evenly applied to the swingable wheel, thereby making the swingable wheel easier to orient to a certain direction based on the user&#39;s directional force applied to a luggage handle. As shown by example in  FIG. 7 , when the axis of rotation ( 707 ,  708 ) for the swingable wheel ( 704 ) is upright (i.e. vertical) and is perpendicular to a flat surface (i.e. conceptually represented by the illustrative horizontal arrow ( 706 ,  709 )) due to an inward tilt provided by the triangular neck portion ( 702 ), the swingable wheel is at an optimal geometrical configuration to provide easy-swinging motions based on the user&#39;s directional force applied to the luggage handle. 
       FIG. 1  shows a user ( 111 ) pushing a wheeled luggage ( 103 ) with a pair of fixed rear wheels ( 106 ) and at least one swingable front wheel ( 112 ) in accordance with the invention. This activity ( 100 ) involving the user ( 111 ) pushing the wheeled luggage ( 103 ) as illustrated in  FIG. 1  is defined as the “push mode.” 
     In one or more embodiments of the invention, the pair of fixed rear wheels ( 106 ) provide linear stability to movement of the wheeled luggage ( 103 ) and a swingable front wheel ( 112 ) provides a directional guidance to the wheeled luggage ( 103 ) depending on the user&#39;s applied force on a handle ( 101 , 102 ) attached to the wheeled luggage ( 103 ). In one embodiment of the invention, a pair of fixed rear wheel covers ( 110 ) covers some portions of the pair of fixed rear wheels ( 106 ). It is important to note that the wheeled luggage ( 103 ) is tilted backward (i.e. towards the user ( 111 )) because an elongated neck creates a higher front clearance than a rear ground clearance created by the pair of fixed rear wheels ( 106 ). The elongated neck comprises a triangular neck portion ( 104 ) which enables an axis of rotation for the swingable front wheel ( 112 ) to make a perpendicular angle ( 7 ) with a flat surface. The elongated neck further comprises an additional neck portion ( 105 ) which contains the swingable front wheel ( 112 ). The additional neck portion ( 105 ) is horizontally swingable by rotating around the axis of rotation contained in the elongated neck, depending on a directional force applied by the user ( 111 ) to the handle ( 101 ,  102 ). 
     The perpendicular angle ( 7 ) enabled by a geometrical tilt provided by the triangular neck portion ( 104 ) is important because the perpendicular ( 7 ) angle provides generally even gravitational pressures on the swingable front wheel ( 112 ), which reduces rotation-hampering forces to the swingable front wheel ( 112 ) based on the directional force applied by the user ( 111 ). A zoomed-in diagram showing this key feature of the invention is also illustrated and described in detail for  FIG. 7  (i.e. the perpendicular angle between  706  and  707  in  FIG. 7 ). 
     Continuing with  FIG. 1 , there is an engineering motivation for tilting the wheeled luggage ( 103 ) backward (i.e. towards the user ( 111 )) in accordance with the invention. If the wheeled luggage ( 103 ) were not tilted backward and instead remained orthogonal to the flat surface, it is ergonomically difficult to apply any horizontal force Fh 1  ( 107 ) to the wheeled luggage ( 103 ) using the handle ( 101 , 102 ) without tipping the wheeled luggage ( 103 ). A simple vector component diagram of a net force provided by the user, Fu 1  ( 109 ), shows a clear advantage of tilting the wheeled luggage ( 103 ) backward when the user decides to apply a diagonal forward-downward force, Fu 1  ( 109 ), to the handle. A simple Newtonian physics vertical and horizontal vector analysis shows that a horizontal vector, Fh 1  ( 107 ), provides a forward push to the wheeled luggage ( 103 ). A vertical vector, Fv 1  ( 108 ), on the other hand, provides a downward force mostly to the pair of fixed rear wheels ( 106 ), thereby helping stability of the wheeled luggage ( 103 ) when the user ( 111 ) applies Fu 1  ( 109 ). 
     An inherent advantage of the present invention comes from the push mode of wheeled luggage ( 103 ). Unlike a pull mode, in which the user is forced to lift a portion of the weight of the wheeled luggage, the push mode benefits from an inherent advantage in laws of physics. By applying the diagonal forward-downward force (i.e. push mode) instead of a forward-upward force (i.e. pull mode), the user leverages gravity and does not have to lift a portion of the weight of the wheeled luggage. Over long distances, the forward-downward force used during the push mode results in superior usability and efficiency for movement of the wheeled luggage, compared to the pull mode. Ease of movement of the wheeled luggage during the push mode is a key feature of the invention. 
       FIG. 2  shows a user ( 211 ) lifting a front swingable wheel ( 206 ) from a surface and pulling a wheeled luggage ( 203 ) using a pair of fixed rear wheels ( 210 ) by applying a forward-upward force, Fu 2  ( 209 ), in accordance with the invention. This activity ( 200 ) involving the user ( 211 ) pushing the wheeled luggage ( 203 ) as illustrated in  FIG. 2  is defined as the “pull mode”. 
     In one or more embodiments of the invention, the pair of fixed rear wheels ( 210 ) provides a linear stability to the movement of the wheeled luggage ( 203 ). An elongated neck creates a higher front clearance than a rear ground clearance created by the pair of fixed rear wheels ( 210 ). The elongated neck comprises a triangular neck portion ( 204 ) and an additional neck portion ( 205 ) which contains the swingable front wheel ( 206 ). The additional neck portion ( 205 ) is horizontally swingable by rotating around a vertical axis contained in the elongated neck, depending on a directional force applied by the user ( 211 ) to the handle ( 201 ,  202 ). Unlike the push mode, the pull mode requires the user ( 211 ) to apply the forward-upward force, Fu 2  ( 209 ), to a handle ( 201 ,  202 ) which necessitates the user ( 211 ) to lift a portion of the weight of the wheeled luggage ( 203 ). 
     A simple Newtonian physics vector diagram ( 207 ,  208 ,  209 ) demonstrates this added burden to the user ( 211 ) for the pull mode. The net force applied by the user ( 211 ) is illustrated by a vector, Fu 2  ( 208 ), which can be broken down into components, a horizontal vector, Fh 2  ( 207 ), and a vertical vector, Fv 2  ( 209 ). The horizontal vector, Fh 2  ( 207 ) is responsible for pulling the wheeled luggage ( 203 ) forward. The vertical vector, Fv 2  ( 208 ), essentially requires the user ( 211 ) to lift up a portion of the weight of the wheeled luggage ( 203 ). In essence, lifting up the portion of the weight of the wheeled luggage ( 203 ) is inefficient and unnecessary (i.e. in light of the push mode described for  FIG. 1 ), but it is an inherent force required in the pull mode. 
     Continuing with  FIG. 2 , although the pull mode requires more effort to the user ( 211 ), it is a conventional mode of moving a wheeled luggage. The wheeled luggage ( 203 ) in accordance with the invention provides this additional mode (i.e. pull mode) of operation for further user convenience. A Newtonian physics-based force efficiency provided by the novel push mode as described in  FIG. 1  and the flexibility of the conventional pull mode as described in  FIG. 2  give the present invention great utility and convenience to the user ( 211 ). 
       FIG. 3  shows a bottom surface of a wheeled luggage ( 303 ) in accordance with one or more embodiments of the invention. A pair of fixed rear wheels ( 304 ), each of which is configured to roll in a corresponding wheel well carved into a main luggage body as shown in  FIG. 3 , provides linear stability to the wheeled luggage ( 303 ) for both push and pull modes as described in  FIG. 1  and  FIG. 2 . A swingable wheel ( 301 ) is located in front of the pair of fixed rear wheels ( 304 ). In one or more embodiments of the invention, the swingable wheel ( 301 ) is roughly equidistant from each fixed rear wheel ( 304 ) and forms a geometrical configuration similar to a tricycle. 
     Continuing with  FIG. 3 , the term “swingable” defines the horizontal circular movement of the swingable wheel ( 301 ), as shown by arrows ( 302 ). The swingable wheel ( 301 ) can be attached to a front portion of the wheeled luggage ( 303 ) by riveting, drilling, or bolting an elongated neck ( 305 ) into the bottom surface of the wheeled luggage ( 303 ). This tricycle-like configuration ( 300 ) with the elongated neck ( 305 ) containing an axis of rotation for the swingable wheel ( 301 ) is a preferred embodiment of the invention. 
       FIG. 4  shows a bottom surface of a wheeled luggage ( 403 ) in accordance with one or more embodiments of the invention. A pair of fixed rear wheels ( 404 ), each of which is configured to roll in a corresponding wheel well carved into a main luggage body as shown in  FIG. 4 , provides linear stability to the wheeled luggage ( 403 ) for both push and pull modes as described in  FIG. 1  and  FIG. 2 . A pair of swingable wheels ( 405 ) is located in front of the pair of fixed rear wheels ( 404 ). In one or more embodiments of the invention, this four-wheel configuration ( 400 ) is optimal for supporting a heavier weight of the wheeled luggage ( 403 ) compared to the tricycle-like configuration ( 300 ) of the wheeled luggage ( 303 ) described in  FIG. 3 . 
     Continuing with  FIG. 4 , the term “swingable” defines the horizontal circular movements of the pair of swingable wheels ( 405 ), as shown by arrows ( 402 ). The pair of swingable wheels ( 405 ) can be attached to a front portion of the wheeled luggage ( 403 ) by riveting or drilling elongated necks ( 401 ) into the bottom surface of the wheeled luggage ( 403 ). 
       FIG. 5  shows a laid-down view ( 500 ) of a wheeled luggage ( 501 ) in accordance with one or more embodiments of the invention. A handle case holder ( 504 ) typically houses a retractable handle ( 505 ), from which a user exerts pushing or pulling force to the wheeled luggage ( 501 ). The handle case holder ( 504 ) and the retractable handle ( 505 ) are typically made of metal or plastic. A pair of fixed rear wheels ( 503 ) can be held together by rear wheel necks which are typically riveted, drilled, or bolted on to a lower rear portion of the wheeled luggage ( 501 ). One or more swingable wheels ( 502 ) is also typically riveted, drilled, or bolted on to a lower front portion of the wheeled luggage ( 501 ). 
       FIG. 6  shows a prior art for a backward-tilted wheeled luggage ( 601 ) which has an axis of rotation ( 607 ,  610 ) for a swingable wheel ( 604 ) forming a non-perpendicular angle (i.e. angle between  606  and  607 ) with a flat surface ( 600 ). In one case of a prior art, an elongated neck ( 603 ) does not have a triangular neck portion which could have tilted the axis of rotation ( 607 ,  610 ) clockwise to overlap a vertical line ( 608 ) to make the axis of rotation ( 607 ,  610 ) perpendicular to the flat surface ( 600 ). Because the axis of rotation ( 607 ,  610 ) instead forms an acute angle ( 606 ,  607 ) and an obtuse angle ( 606 ,  610 ) with the flat surface ( 600 ), such non-perpendicular angles between the axis of rotation ( 607 ,  610 ) and the flat surface ( 600 ) hamper the user from pushing the wheeled luggage efficiently because the horizontal “swing” or directional movements of the swingable wheel is hampered by uneven pressure to the swingable wheel. In another case of a prior art, the elongated neck ( 603 ) includes a triangular neck portion but does not tilt the axis of rotation ( 607 ,  610 ) sufficiently to make the axis of rotation ( 607 ,  610 ) perpendicular to the flat surface ( 600 ). Any non-vertical and non-perpendicular axis of rotation relative to the flat surface ( 600 ) is not optimal for easy swinging motions of the swingable wheel ( 604 ) for the wheeled luggage ( 601 ). 
       FIG. 7  shows a zoomed-in view of a swingable wheel ( 704 ) located at a lower front portion of the wheeled luggage ( 701 ) in accordance with one or more embodiments of the invention. A triangular neck portion ( 702 ) of an elongated neck ( 702 ,  703 ) enables an axis of rotation ( 707 ,  708 ) for the swingable wheel ( 704 ) to be vertical, thereby forming a perpendicular angle (i.e. angle between  706  and  707 ) with a flat surface ( 700 ), as represented by a illustrative horizontal arrow ( 706 ,  709 ). With the triangular neck portion ( 702 ) as illustrated in  FIG. 7 , gravitational pressure is generally more evenly applied to the swingable wheel, thereby making the swingable wheel easier to orient to a certain direction based on the user&#39;s directional force applied to a luggage handle. As shown by example in  FIG. 7 , when the axis of rotation ( 707 ,  708 ) for the swingable wheel ( 704 ) is perpendicular to a flat surface (i.e. conceptually represented by the illustrative horizontal arrow ( 706 ,  709 )) by a geometrical tilt provided by the triangular neck portion ( 702 ), the swingable wheel is at an optimal geometrical configuration to provide easy-swinging motions (e.g.  302 ,  402 ) based on the user&#39;s directional force applied to the luggage handle. The elongated neck ( 702 ,  703 ) also gives the wheeled luggage ( 701 ) a higher ground clearance in the front than the rear, creating a backward tilt necessary for the user to apply a diagonal forward-downward force to a handle to propel the wheeled luggage for the push mode. A lower portion of the elongated neck ( 703 ) is horizontally swingable along a vertical axis of rotation contained within the elongated neck ( 702 ,  703 ). This horizontal, circular swinging action enables the swingable wheel ( 704 ) configured to roll within the lower portion of the elongated neck ( 703 ) to swing around the vertical axis of rotation depending on a directional force applied by the user. 
       FIG. 8  shows a side view ( 800 ) of a removable front swingable wheel ( 809 ) detached from a wheeled luggage ( 802 ), and a slide rail ( 803 ) and a ball detent mechanism ( 804 A,  804 B) on a lower portion of a wheeled luggage, in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 809 ) is configured to be guided (i.e.  811 ) into the slide rail ( 803 ) which is attached to a triangular neck portion ( 805 ) of the wheeled luggage ( 802 ). In another embodiment of the invention, the triangular neck portion ( 805 ) may be part of a sliding plate ( 806 ) of the removable front swingable wheel. In the preferred embodiment of the invention, the ball detent mechanism ( 804 A,  804 B) enables one or more locking holes ( 807 A,  807 B) on a sliding plate ( 806 ) of the removable front swingable wheel ( 809 ) to be “locked” to a fixed position, if the sliding plate ( 806 ) is inserted into the slide rail ( 803 ). In one embodiment of the invention, one or more fixed rear wheels ( 801 ) provide stability for a straight-path movement of the wheeled luggage ( 802 ). The one or more fixed rear wheels ( 801 ) may be at least partially covered by one or more wheel covers ( 812 ), depending on a particular embodiment of the present invention. 
     In one embodiment of the invention, the removable front swingable wheel ( 809 ) is attached to an additional neck portion ( 808 ) which is attached to the sliding plate ( 806 ). The additional neck portion ( 808 ) can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 809 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 802 ) has a higher front ground-clearance height relative to a rear ground-clearance height in an attached mode for the removable front swingable wheel ( 809 ), because the triangular neck portion ( 805 ) and/or the additional neck portion ( 808 ) provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 801 ). 
     Continuing with  FIG. 8 , it should be noted that a significant novelty of the present invention is that the triangular neck portion ( 805 ) enables the vertical axis of swinging rotation of the removable front swingable wheel ( 809 ) to form a perpendicular angle with a flat (i.e. horizontal) surface (i.e.  706 ,  707  in  FIG. 7 ). Furthermore, another novelty of the present invention is that the removable front swingable wheel ( 809 ) is configured to be attached, detached, and/or re-attached depending on a user&#39;s needs and desires during a transport using the wheeled luggage ( 802 ). For example, if the user is traveling on a flat surface with a heavy load inside the wheeled luggage ( 802 ), the user may find pushing the wheeled luggage ( 802 ) forward in a backward-tilt configuration with the removable front swingable wheel ( 809 ) in an attached mode more convenient for the transport. On the other hand, if the user is resting on a sloped surface, then the user may find detaching the removable front swingable wheel ( 809 ) more convenient for keeping the wheeled luggage stationary. If the removable front swingable wheel ( 809 ) is detached from the wheeled luggage ( 802 ), a luggage leg ( 810 ) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 802 ) level. 
       FIG. 9  shows a side-bottom perspective view ( 900 ) of a removable front swingable wheel ( 909 ) and a sliding plate ( 906 ) in a “snap-in” or a locking position with a slide rail ( 903 ) and a ball detent mechanism ( 904 A,  904 B) on a lower surface of a wheeled luggage ( 902 ), in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 909 ) attached to the sliding plate ( 906 ) is configured to be guided into the slide rail ( 903 ) which is attached to a triangular neck portion ( 905 ) of the wheeled luggage ( 902 ). In another embodiment of the invention, the triangular neck portion ( 905 ) may be part of a sliding plate ( 906 ) of the removable front swingable wheel. In the preferred embodiment of the invention, the ball detent mechanism ( 904 A,  904 B) enables one or more locking holes on the sliding plate ( 906 ) of the removable front swingable wheel ( 909 ) to be “locked” to a fixed position, when the sliding plate ( 906 ) is inserted into the slide rail ( 903 ) sufficiently to contact the ball detent mechanism ( 904 A,  904 B). In one embodiment of the invention, one or more fixed rear wheels ( 901 A,  901 B) provide stability for a straight-path movement of the wheeled luggage ( 902 ). The one or more fixed rear wheels ( 901 A,  901 B) may be at least partially covered by one or more wheel covers ( 912 A,  912 B), depending on a particular embodiment of the present invention. In a preferred embodiment of the invention, the wheeled luggage ( 902 ) has a higher front ground-clearance height relative to a rear ground-clearance height if the removable front swingable wheel ( 909 ) is in an attached mode because the triangular neck portion ( 905 ) and/or an additional neck portion provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 901 A,  901 B). If the removable front swingable wheel ( 909 ) is detached from the wheeled luggage ( 902 ), one or more luggage legs ( 910 A,  910 B) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 902 ) level. 
       FIG. 10  shows a side-bottom perspective view ( 1000 ) of a removable front swingable wheel ( 1009 ) and a sliding plate ( 1006 ) configured to snap into an attached position with a slide rail ( 1003 ) and a ball detent mechanism ( 1004 A,  1004 B) on a bottom surface of a wheeled luggage ( 1002 ), in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 1009 ) attached to the sliding plate ( 1006 ) is configured to be guided into the slide rail ( 1003 ) which is attached to a triangular neck portion ( 1005 ) of the wheeled luggage ( 1002 ). In another embodiment of the invention, the triangular neck portion ( 1005 ) may be part of a sliding plate ( 1006 ) of the removable front swingable wheel ( 1009 ). In the preferred embodiment of the invention, the ball detent mechanism ( 1004 A,  1004 B) enables one or more locking holes ( 1007 A,  1007 B) on the sliding plate ( 1006 ) of the removable front swingable wheel ( 1009 ) to be “locked” to a fixed “snap-in” position, when the sliding plate ( 1006 ) is inserted (i.e.  1011 ) into the slide rail ( 1003 ) sufficiently to enable the ball detent mechanism ( 1004 A,  1004 B) to lock into the one or more locking holes ( 1007 A,  1007 B). In one embodiment of the invention, one or more fixed rear wheels ( 1001 A,  1001 B) provide stability for a straight-path movement of the wheeled luggage ( 1002 ). The one or more fixed rear wheels ( 1001 A,  1001 B) may be at least partially covered by one or more wheel covers ( 1012 A,  1012 B), depending on a particular embodiment of the present invention. In a preferred embodiment of the invention, the wheeled luggage ( 1002 ) has a higher front ground-clearance height relative to a rear ground-clearance height because the triangular neck portion ( 1005 ) and/or an additional neck portion provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1001 A,  1001 B) in an attached mode for the removable front swingable wheel ( 1009 ). If the removable front swingable wheel ( 1009 ) is detached from the wheeled luggage ( 1002 ), one or more luggage legs ( 1010 A,  1010 B) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1002 ) level. 
       FIG. 11  shows a side view ( 1100 ) of a bottom portion of a wheeled luggage ( 1102 ) with a first Velcro surface ( 1103 ) and a removable front swingable wheel ( 1104 ) with a second Velcro surface ( 1107 ) separated from a wheeled luggage, in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 1104 ) is attached to an additional neck portion ( 1105 ) which is attached to a triangular neck portion ( 1106 ). In the preferred embodiment of the invention, the second Velcro surface ( 1107 ) is attached to a top surface of the triangular neck portion ( 1106 ). In another embodiment of the invention, the triangular neck portion ( 1106 ) may simply be part of a lower portion of the wheeled luggage ( 1102 ) with a first Velcro surface on a bottom surface of the triangular neck portion, and a second Velcro surface may be attached to a top surface of the additional neck portion ( 1105 ). If the first Velcro surface (e.g.  1103 ) and the second Velcro surface (e.g.  1107 ) are brought together for a physical contact (i.e.  1109 ), the first Velcro surface and the second Velcro surface are designed to adhere upon the physical contact. Velcro surfaces are typically designed to have a “male” surface and a “female” surface, which adhere together upon contact. For example, a male Velcro surface typically provides numerous “micro-hooks” which are designed to hook onto a female Velcro surface typically comprising “micro-loops”. Furthermore, male and female Velcro surfaces which form adherence upon physical contact can be separated again by force, if a sufficient force is applied to separate the male and female Velcro surfaces. 
     In one embodiment of the invention, one or more fixed rear wheels ( 1101 ) provide stability for a straight-path movement of the wheeled luggage ( 1102 ). The one or more fixed rear wheels ( 1101 ) may be at least partially covered by one or more wheel covers ( 1110 ), depending on a particular embodiment of the present invention. Furthermore, in one embodiment of the invention, the additional neck portion ( 1105 ) can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 1104 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 1102 ) has a higher front ground-clearance height relative to a rear ground-clearance height because the triangular neck portion ( 1106 ) and/or the additional neck portion ( 1105 ) provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1101 ). 
     Continuing with  FIG. 11 , it should be noted that a significant novelty of the present invention is that the triangular neck portion ( 1106 ) enables the vertical axis of swinging rotation of the removable front swingable wheel ( 1104 ) to form a perpendicular angle with a flat (i.e. horizontal) surface (i.e.  706 ,  707  in  FIG. 7 ). Furthermore, another novelty of the present invention is that the removable front swingable wheel ( 1104 ) is configured to be attached, detached, and/or re-attached depending on a user&#39;s needs and desires during transport using the wheeled luggage ( 1102 ). For example, if the user is traveling on a flat surface with a heavy load inside the wheeled luggage ( 1102 ), the user may find pushing the wheeled luggage ( 1102 ) forward in a backward-tilt configuration with the removable front swingable wheel ( 1104 ) in an attached mode more convenient for the transport. On the other hand, if the user is resting on a sloped surface, then the user may find detaching the removable front swingable wheel ( 1104 ) more convenient for keeping the wheeled luggage ( 1102 ) stationary. If the removable front swingable wheel ( 1104 ) is detached from the wheeled luggage ( 1102 ), a luggage leg ( 1108 ) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1102 ) level. 
       FIG. 12  shows a side-bottom perspective view ( 1200 ) of a bottom portion ( 1211 ) of a wheeled luggage ( 1202 ) with a first Velcro surface ( 1203 ) and a removable front swingable wheel ( 1204 ) with a second Velcro surface ( 1207 ) separated from a wheeled luggage ( 1202 ), in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 1204 ) is attached to an additional neck portion which is attached to a triangular neck portion ( 1206 ). In the preferred embodiment of the invention, the second Velcro surface ( 1207 ) is attached to a top surface of the triangular neck portion ( 1206 ). In another embodiment of the invention, the triangular neck portion ( 1206 ) may simply be part of a lower portion of the wheeled luggage ( 1202 ) with a first Velcro surface on a bottom surface of the triangular neck portion, and a second Velcro surface may be attached to a top surface of the additional neck portion. If the first Velcro surface (e.g.  1203 ) and the second Velcro surface (e.g.  1207 ) are brought together (i.e.  1209 ) for a physical contact, the first Velcro surface and the second Velcro surface are designed to adhere upon physical contact. Velcro surfaces are typically designed to have a “male” surface and a “female” surface, which adhere together upon contact. For example, a male Velcro surface typically provides numerous “micro-hooks” which are designed to hook onto a female Velcro surface typically comprising “micro-loops”. Furthermore, male and female Velcro surfaces which form adherence upon physical contact can be separated again by force, if a sufficient force is applied to separate the male and female Velcro surfaces. 
     In one embodiment of the invention, one or more fixed rear wheels ( 1201 A,  1201 B) provide stability for a straight-path movement of the wheeled luggage ( 1202 ). The one or more fixed rear wheels ( 1201 A,  1201 B) may be at least partially covered by one or more wheel covers ( 1210 A,  1210 B), depending on a particular embodiment of the present invention. Furthermore, in one embodiment of the invention, the additional neck portion can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 1204 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 1202 ) has a higher front ground-clearance height relative to a rear ground-clearance height if the removable front swingable wheel ( 1204 ) is in an attached mode because the triangular neck portion ( 1206 ) and/or the additional neck portion provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1201 A,  1201 B). If the removable front swingable wheel ( 1204 ) is separated from the wheeled luggage ( 1202 ), then one or more luggage legs ( 1208 A,  1208 B) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1202 ) level. 
       FIG. 13  shows a side-bottom perspective view ( 1300 ) of a bottom portion of a wheeled luggage ( 1302 ) with a first Velcro surface ( 1303 ) attached to a second Velcro surface on top of a triangular neck portion ( 1306 ) of a removable front swingable wheel ( 1304 ), in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 1304 ) is attached to an additional neck portion which is attached to a triangular neck portion ( 1306 ). In the preferred embodiment of the invention, the second Velcro surface is attached to a top surface of the triangular neck portion ( 1306 ). In another embodiment of the invention, the triangular neck portion ( 1306 ) may simply be part of a lower portion of the wheeled luggage ( 1302 ) with a first Velcro surface on a bottom surface of the triangular neck portion, and a second Velcro surface may be attached to a top surface of the additional neck portion. 
     In one embodiment of the invention, one or more fixed rear wheels ( 1301 A,  1301 B) provide stability for a straight-path movement of the wheeled luggage ( 1302 ). The one or more fixed rear wheels ( 1301 A,  1301 B) may be at least partially covered by one or more wheel covers ( 1310 A,  1310 B), depending on a particular embodiment of the present invention. Furthermore, in one embodiment of the invention, the additional neck portion can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 1304 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 1302 ) has a higher front ground-clearance height relative to a rear ground-clearance height if the removable front swingable wheel ( 1304 ) is in an attached mode because the triangular neck portion ( 1306 ) and/or the additional neck portion provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1301 A,  1301 B). If the removable front swingable wheel ( 1304 ) is separated from the wheeled luggage ( 1302 ), then one or more luggage legs ( 1308 A,  1308 B) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1302 ) level. 
       FIG. 14  shows a side view ( 1400 ) of a removable front swingable wheel ( 1409 ) underneath an additional neck ( 1404 ), and a snap-fit male guide ( 1403 ) attached on top of a male guide stand ( 1406 ) which are detached from a wheeled luggage ( 1402 ).  FIG. 14  also shows a snap-fit female guide ( 1407 ) at a bottom portion of the wheeled luggage ( 1402 ), in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 1409 ) is configured to be guided (i.e.  1408 ) into a snap-fit female guide ( 1407 ) which is attached to a triangular neck portion ( 1405 ) of the wheeled luggage ( 1402 ). In another embodiment of the invention, the triangular neck portion ( 1405 ) may be part of a male guide stand ( 1406 ) and/or a snap-fit male guide ( 1403 ) of the removable front swingable wheel ( 1409 ). In the preferred embodiment of the invention, the snap-fit female guide ( 1407 ) contains a hook or a ball detent mechanism to lock an incoming snap-fit male guide (i.e.  1408 ) to a fixed position (i.e. a “snap-fit” position). In one embodiment of the invention, one or more fixed rear wheels ( 1401 ) provide stability for a straight-path movement of the wheeled luggage ( 1402 ). The one or more fixed rear wheels ( 1401 ) may be at least partially covered by one or more wheel covers ( 1412 ), depending on a particular embodiment of the present invention. 
     In one embodiment of the invention, the removable front swingable wheel ( 1409 ) is attached to an additional neck portion ( 1404 ) which is attached to the snap-fit male guide stand ( 1406 ). The additional neck portion ( 1404 ) can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 1409 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 1402 ) has a higher front ground-clearance height relative to a rear ground-clearance height in an attached mode for the removable front swingable wheel ( 1409 ), because the triangular neck portion ( 1405 ) and/or the additional neck portion ( 1404 ) provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1401 ). If the removable front swingable wheel ( 1409 ) is detached from the wheeled luggage ( 1402 ), a luggage leg ( 1410 ) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1402 ) level. 
       FIG. 15  shows a side-bottom perspective view ( 1500 ) of a removable front swingable wheel ( 1509 ) underneath an additional neck portion ( 1504 ), and a snap-fit male guide ( 1503 ) attached on top of a male guide stand ( 1506 ) which are detached from a wheeled luggage ( 1502 ).  FIG. 15  also shows a snap-fit female guide ( 1507 ) at a bottom portion ( 1511 ) of the wheeled luggage ( 1502 ), in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 1509 ) is configured to be guided (i.e.  1508 ) into a snap-fit female guide ( 1507 ) which is attached to a triangular neck portion ( 1505 ) of the wheeled luggage ( 1502 ). In another embodiment of the invention, the triangular neck portion ( 1505 ) may be part of a male guide stand ( 1506 ) and/or a snap-fit male guide ( 1503 ) of the removable front swingable wheel ( 1509 ). In the preferred embodiment of the invention, the snap-fit female guide ( 1507 ) contains a hook or a ball detent mechanism to lock an incoming snap-fit male guide (i.e.  1508 ) to a fixed position (i.e. a “snap-fit” position). In one embodiment of the invention, one or more fixed rear wheels ( 1501 A,  1501 B) provide stability for a straight-path movement of the wheeled luggage ( 1502 ). The one or more fixed rear wheels ( 1501 A,  1501 B) may be at least partially covered by one or more wheel covers ( 1512 A,  1512 B), depending on a particular embodiment of the present invention. 
     In one embodiment of the invention, the removable front swingable wheel ( 1509 ) is attached to an additional neck portion ( 1504 ) which is attached to the snap-fit male guide stand ( 1506 ). The additional neck portion ( 1504 ) can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 1509 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 1502 ) has a higher front ground-clearance height relative to a rear ground-clearance height in an attached mode for the removable front swingable wheel ( 1509 ), because the triangular neck portion ( 1505 ) and/or the additional neck portion ( 1504 ) provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1501 A,  1501 B). If the removable front swingable wheel ( 1509 ) is detached from the wheeled luggage ( 1502 ), one or more luggage legs ( 1510 A,  1510 B) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1502 ) level. 
       FIG. 16  shows a side view ( 1600 ) of a removable front swingable wheel ( 1609 ) underneath an additional neck portion ( 1604 ), and a snap-fit female guide ( 1603 ) embedded in a female guide stand ( 1606 ), which are detached from a wheeled luggage ( 1602 ).  FIG. 16  also shows a snap-fit male guide ( 1607 ) at a bottom portion of a wheeled luggage ( 1602 ), in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 1609 ) is configured to be guided (i.e.  1608 ) into a snap-fit male guide ( 1607 ) which is attached to a triangular neck portion ( 1605 ) of the wheeled luggage ( 1602 ). In another embodiment of the invention, the triangular neck portion ( 1605 ) may be part of a female guide stand ( 1606 ) and/or a snap-fit female guide ( 1603 ) of the removable front swingable wheel ( 1609 ). In the preferred embodiment of the invention, the snap-fit female guide ( 1603 ) contains a hook or a ball detent mechanism to lock a docking snap-fit male guide (i.e.  1608 ) to a fixed position (i.e. a “snap-fit” position). In one embodiment of the invention, one or more fixed rear wheels ( 1601 ) provide stability for a straight-path movement of the wheeled luggage ( 1602 ). The one or more fixed rear wheels ( 1601 ) may be at least partially covered by one or more wheel covers ( 1612 ), depending on a particular embodiment of the present invention. 
     In one embodiment of the invention, the removable front swingable wheel ( 1609 ) is attached to an additional neck portion ( 1604 ) which is attached to the snap-fit female guide stand ( 1606 ). The additional neck portion ( 1604 ) can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 1609 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 1602 ) has a higher front ground-clearance height relative to a rear ground-clearance height in an attached mode for the removable front swingable wheel ( 1609 ), because the triangular neck portion ( 1605 ) and/or the additional neck portion ( 1604 ) provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1601 ). If the removable front swingable wheel ( 1609 ) is detached from the wheeled luggage ( 1602 ), a luggage leg ( 1610 ) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1602 ) level. 
       FIG. 17  shows a side-bottom perspective view ( 1700 ) of a removable front swingable wheel ( 1709 ) underneath an additional neck portion ( 1704 ), and a snap-fit female guide embedded in a female guide stand ( 1706 ), which are detached from a wheeled luggage ( 1702 ).  FIG. 17  also shows a snap-fit male guide ( 1707 ) at a bottom portion ( 1711 ) of the wheeled luggage ( 1702 ), in accordance with one or more embodiments of the invention. In a preferred embodiment of the invention, the removable front swingable wheel ( 1709 ) is configured to be guided (i.e.  1708 ) into a snap-fit male guide ( 1707 ) which is attached to a triangular neck portion ( 1705 ) of the wheeled luggage ( 1702 ). In another embodiment of the invention, the triangular neck portion ( 1705 ) may be part of a female guide stand ( 1706 ) and/or a snap-fit female guide of the removable front swingable wheel ( 1709 ). In the preferred embodiment of the invention, the snap-fit female guide contains a hook or a ball detent mechanism to lock a docking snap-fit male guide (i.e.  1708 ) to a fixed position (i.e. a “snap-fit” position). In one embodiment of the invention, one or more fixed rear wheels ( 1701 A,  1701 B) provide stability for a straight-path movement of the wheeled luggage ( 1702 ). The one or more fixed rear wheels ( 1701 A,  1701 B) may be at least partially covered by one or more wheel covers ( 1712 A,  1712 B), depending on a particular embodiment of the present invention. 
     In one embodiment of the invention, the removable front swingable wheel ( 1709 ) is attached to an additional neck portion ( 1704 ) which is attached to the snap-fit female guide stand ( 1706 ). The additional neck portion ( 1704 ) can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 1709 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 1702 ) has a higher front ground-clearance height relative to a rear ground-clearance height in an attached mode for the removable front swingable wheel ( 1709 ), because the triangular neck portion ( 1705 ) and/or the additional neck portion ( 1704 ) provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1701 A,  1701 B). If the removable front swingable wheel ( 1709 ) is detached from the wheeled luggage ( 1702 ), one or more luggage legs ( 1710 A,  1710 B) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1702 ) level. 
       FIG. 18  shows a side-bottom perspective view ( 1800 ) of a removable front swingable wheel ( 1809 ) underneath an additional neck portion and a snap-fit male or female guide embedded in a male or female guide stand ( 1806 ), which are fully inserted to a locking position with a snap-fit male or female guide of a wheeled luggage ( 1802 ). In a preferred embodiment of the invention, the removable front swingable wheel ( 1809 ) is configured to be guided into a snap-fit male or female guide which is attached to a triangular neck portion ( 1805 ) of the wheeled luggage ( 1802 ). In another embodiment of the invention, the triangular neck portion ( 1805 ) may be part of a male or female guide stand ( 1806 ) and/or a snap-fit male or female guide of the removable front swingable wheel ( 1809 ). In the preferred embodiment of the invention, the snap-fit male or female guide contains a hook or a ball detent mechanism to lock a docking snap-fit male or female guide to a fixed position (i.e. a “snap-fit” position). In one embodiment of the invention, one or more fixed rear wheels ( 1801 A,  1801 B) provide stability for a straight-path movement of the wheeled luggage ( 1802 ). The one or more fixed rear wheels ( 1801 A,  1801 B) may be at least partially covered by one or more wheel covers ( 1812 A,  1812 B), depending on a particular embodiment of the present invention. 
     In one embodiment of the invention, the removable front swingable wheel ( 1809 ) is attached to an additional neck portion which is attached to the snap-fit male or female guide stand ( 1806 ). The additional neck portion can be configured to be horizontally “swingable” and can contain a vertical axis of rotation for the removable front swingable wheel ( 1809 ). Furthermore, in a preferred embodiment of the invention, the wheeled luggage ( 1802 ) has a higher front ground-clearance height relative to a rear ground-clearance height in an attached mode for the removable front swingable wheel ( 1809 ), because the triangular neck portion ( 1805 ) and/or the additional neck portion provides an elevated front ground clearance compared to a ground clearance provided by one or more fixed rear wheels ( 1801 A,  1801 B). 
     Continuing with  FIG. 18 , it should be noted that a significant novelty of the present invention is that the triangular neck portion ( 1805 ) enables the vertical axis of swinging rotation of the removable front swingable wheel ( 1809 ) to form a perpendicular angle with a flat (i.e. horizontal) surface (i.e.  706 ,  707  in  FIG. 7 ). Furthermore, another novelty of the present invention is that the removable front swingable wheel ( 1809 ) is configured to be attached, detached, and/or re-attached depending on a user&#39;s needs and desires during a transport using the wheeled luggage ( 1802 ). For example, if the user is traveling on a flat surface with a heavy load inside the wheeled luggage ( 1802 ), the user may find pushing the wheeled luggage ( 1802 ) forward in a backward-tilt configuration with the removable front swingable wheel ( 1809 ) in an attached mode more convenient for the transport. On the other hand, if the user is resting on a sloped surface, then the user may find detaching the removable front swingable wheel ( 1809 ) more convenient for keeping the wheeled luggage stationary. If the removable front swingable wheel ( 1809 ) is detached from the wheeled luggage ( 1802 ), one or more luggage legs ( 1810 A,  1810 B) may provide a sufficient front ground clearance to make the overall ground clearance of the wheeled luggage ( 1802 ) level. 
     While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims.