Travel bags and suitcases having wheels and handles are well known. Such bags typically have a set of wheels and a handle to enable the user to pull the bag along a relatively even and/ or flat surface. However, when the user encounters a set of stairs they invariably have to stop and carry the bag up the stairs. This can be difficult and can require significant effort in cases where the bag is heavy.

It is an object of the invention to seek to mitigate problems such as the aforementioned.

According to a first aspect of the invention, there is provided a bag comprising a handle and at least one wheel to facilitate movement of the bag along a fiat surface, wherein the handle is rotatably attached to the bag so that the bag can move relative to the handle, and wherein the at least one wheel does not interfere with movement of the bag as it ascends and/ or descends an incline. Advantageously, the user doesn't have to carry the bag of the present invention as he moves the bag along a flat horizontal surface and/ or as he moves the bag up and/ or down an incline such as a set of stairs or an escalator.

Typically, when the user encounters an incline such as a set of stairs, he pulls the bag via the handle to move and slide the bag up and./ or down the stairs. Preferably, the handle rotates with respect to an axis of rotation of the bag such that the angle of the handle with respect to the bag may be adjusted to a position which reduces the force and thus the effort required to move the bag up and/ or down a set of stairs. In one embodiment, the handle may rotate such that the angle of the handle with respect to the central horizontal axis of the bag may be adjusted to a position which reduces the effort required to move the bag up and/ or down a set of stairs. Advantageously, the bag of the present invention allows a user to traverse an incline such as a set of stairs without the requirement to lift the bag clear of the surface. Advantageously, the bag of the present invention allows a user to navigate a set of stairs with relative ease when moving the bag, through rotation of the handle with respect to the bag. Advantageously, the bag of the present invention allows a user towing the bag to traverse a flat surface and/ or an incline such as a set of stairs with relative ease.

Preferably, the bag comprises a body having a front wall, a rear wall and a plurality of sidewalls that extend peripherally of the front and rear walls. Typically, the bag comprises four sidewalls that support the front and rear walls in spaced relation therewith. It is preferred that the front and rear walls have a greater surface area than the surface area of the sidewalls. Typically, the bag comprises four sidewalls, known as left, right, top and bottom sidewalls when the bag is in the upright, vertical configuration. In an embodiment wherein the bag is substantially rectangular in shape, the upright, vertical configuration is achieved when the longitudinal axis (i.e. the longest axis) of the bag is substantially perpendicular to the surface of the ground.

Preferably, the handle comprises two arms and a crossbar (also known as a handlebar). Preferably, the two amis of the handle are substantially parallel to one another and the crossbar extends between and joins the two arms, thus forming a U-shape. Preferably, the handle is attached to the bag via the arms and the user grips and pulls the handle via the crossbar. It is preferred that the handle is attached to the bag at a distal end of the arms (i.e. the end furthest from the user). It is further preferred that the crossbar extends between and joins the two arms of the handle at a proximal end thereof (i.e. the end closest to the user).

Preferably, the handle is attached to the bag at a point substantially at the centre of at least one of the sidewalls of the bag. It is preferred that the handle is attached at a substantially central point located on two opposite and parallel sidewalls of the bag. Preferably, the handle is attached to a substantially central point located on the left and/ or right sidewalls of the bag, when the bag is in the upright, vertical configuration. In one embodiment, the handle may be attached to the bag such that the axis of rotation of the handle may be substantially along the central point of gravity of the bag.

In one embodiment, the bag comprises at least one pair of wheels. Typically, the bag comprises two pairs of wheels. Preferably, the bag comprises four wheels, i.e. two pairs of wheels. Advantageously, the wheels engage with and assist the movement of the bag along a flat surface. Preferably, each wheel is attached to the bag via an axel. Preferably, each pair of wheels is located at an opposite end of the bag. Preferably, two wheels are attached to the bottom sidewall of the bag (i.e. the sidewail adjacent to the ground when the bag is in the upright, vertical configuration), and two wheels are attached to the top sidewall (i.e. the sidewall opposite and parallel thereto). Advantageously, the provision of a pair of wheels at opposite ends of the bag allows a user to rotate the bag through 180 degrees and then pull the bag along a surface via the wheels provided at the other end of the bag. It is preferred that each pair of wheels is located at a diagonally opposite end of the bag.

Preferably, the at least one wheel is at least substantially flush with the outer surface of the front and/ or rear wall of the bag. Advantageously, providing the wheels such that they are substantially flush with, i.e. inside of the outer surface of the front and/ or rear wall of the bag, means that the wheels do not interfere with the sliding movement of the bag as the user ascends and/ or descends an incline. In another embodiment, the at least one wheel may be at least substantially flush with the end of the bag, thus allowing the bag to stand freely in the upright and vertical configuration without manipulation by a user.

Preferably, the bag comprises at least one slider. It is preferred that the bag comprises at least two sliders. In one embodiment, the bag may comprise two sets of sliders. Advantageously, the at least one slider does not interfere with the movement of the bag as it ascends and/ or descends an incline, such as a set of stairs. Preferably, the at least one slider comprises a durable material such as a plastics or metal material, or another material that reduces the effect of friction on the bag. Preferably, the at least one slider is attached to the outer surface of the front and/ or rear wall of the bag. It is preferred that the bag comprises two sliders, wherein one slider is attached to the front wall of the bag and one slider is attached to the rear wall of the bag. Advantageously, the at least one slider assists in the movement of the bag up and/ or down an incline such as a set of stairs by providing a smooth surface. In one embodiment, the at least one slider may be provided in the form of sleigh-like strips. Advantageously, the provision of at least one slider provides a smooth surface and protects the outer surface of the bag from abrasion which may be caused by friction. Preferably, the at least one slider is replaceable, for example, following wear of the slider over a period of time. In one embodiment, the at least one slider may not be provided on the top and/ or bottom sidewalls of the bag when the bag is in the vertical configuration. Preferably, the bag further comprises at least one gripper element. Preferably, the bag comprises two gripper elements. Typically, the at least one gripper element comprises a non-slip material. Preferably, the non-slip material is provided on the sidewalls of the bag, preferably on the sidewalls to which the wheels attach. In one embodiment, the non-slip material may be provided at a region of a sidewall of the bag, adjacent to the region where the wheels are attached, hi another embodiment, the non-slip material may be provided at a region of a sidewall of the bag opposite to the position where the wheels are attached. Preferably, the at least one gripper element is provided adjacent the central longitudinal axis of the bag. In one embodiment, the gripper element may be provided at a position on the top and/ or bottom sidewall of the bag opposite to the point of attachment of the at least one wheel. Advantageously, the provision of a non-slip surface assists in rotation of the bag. For example, as the non-slip surface contacts the surface of the ground and/ or the angular portion of a stair, the handle rotates with respect to an axis of rotation of the bag, assisting the user in pulling the bag up the incline of the stairs. Preferably, the non-slip material comprises a plastics or rubber material.

Typically, the bag is substantially rectangular in shape. Typically, the bag is a suitcase.

Preferably, the bag further comprises bevelled and/ or rounded comers. In one embodiment, one of the comers at the top and/ or bottom end of the bag may be bevelled and/ or rounded and the other comer may comprises the at least one wheel. In another embodiment, all of the comers of the bag may be bevelled and/ or rounded. Advantageously, the provision of bevelled and/ or rounded corners allows for smooth movement of the bag up and/ or down a set of stairs, as the bag is not caught on the angular portion of the steps. Advantageously, the provision of bevelled and/ or rounded comers enables the user to pull and/ or tow the bag along a surface at a range of angles to the ground.

Preferably, the handle comprises a ratchet mechanism to allow the user to control the angle of the handle relative to an axis of rotation of the bag. In one embodiment, the handle may be attached to the bag via a hinge. Advantageously, the handle may pivot about an axis of rotation of the bag and may rotate through a range of angles until it reaches a position at which the user can comfortably tow the bag, i.e. reducing the effort and/ or gravitational force required to pull the bag. It is preferred that the bag further comprises releasable locking means to lock the handle in position with respect to the bag. Typically, the releasable locking means comprises a ratchet mechanism. In another embodiment, the releasable locking means may comprise a cogwheel in combination with an outer ring. Advantageously, the releasable locking means may be configured to achieve a desired range of angles of the handle with respect to an axis of rotation of the bag. Advantageously, the provision of a releasable locking mechanism means that the handle can be fixed at any desired angle with respect to the bag such that it will not rotate as the user pulls the bag along a surface. The user can then use the handle to adjust the angle of the bag with respect to the axis of the ground surface. In a preferred embodiment, the user may rotate the bag via the handle such that the angle of the bag with respect to the axis of the ground surface is 45 degrees. Advantageously, the provision of releasable locking means allows the lock to be released at a desired time such that the user can adjust the angle of the handle with respect to the central horizontal axis of the bag. Preferably, the handle comprises a rigid material. Preferably, the handle comprises an aluminium alloy.

Preferably, the length of the handle is adjustable. It is preferred that the handle is extendable and/ or retractable. Typically, the handle comprises telescopic means to allow it to be extended and/ or retracted. In the embodiment where the handle is not in use, the handle may be retracted and/ or wrapped around the outer surface of the bag. In one embodiment, the bag may further comprise an inlay which may accommodate the handle when the handle is in the retracted position and not in use. Typically, the inlay may be a pre-defined groove which may be provided within at least one of the sidewalls of the bag. It is preferred that the inlay is provided along four sidewalls of the bag, i.e. the inlay may be provided on the sidewalls of the bag such that it encircles the sidewalls of the bag. Preferably, the dimensions of the inlay are such that the handle may be securely held within the inlay when not in use. In the embodiment where the handle is in use, the handle may be extended to facilitate adjustment of the position of the handle with respect to the bag, and to allow the user to pull the bag along a ground surface, and/ or up and/ or down a set of stairs.

In one embodiment, the bag further comprises a closing means. Preferably, the closing means comprises a zip. Alternatively or additionally, the closing means may comprise toggle latches and/ or hinges. Preferably, the closing means extends around at least three sidewalk of the bag, to allow the user to open the bag to retrieve the contents therefrom. Typically, the closing means and/ or the inlay may be provided at a range of angles with respect to the longitudinal axis of the bag. Preferably, the longest axis of the closing means and/ or the inlay is provided such that they are substantially parallel to the longitudinal axis of the bag.

In one embodiment, the closing means are provided around three sidewalls of the bag and the remaining sidewall comprises a hinging mechanism to facilitate opening and closing of the bag, Preferably, the front, rear and/ or sidewalls of the bag are substantially rigid and may comprise layers of woven polypropylene fabrics, formed into self-reinforced composite sheets.

Advantageously, such materials minimise the weight of the bag, whilst providing exceptional strength and resistance to impact, for example, at low temperature. The invention will be further described by way of example, with reference to the following drawings and figures, in which:

Figure 1 is a schematic perspective view of a bag according to the invention: Figure 2 is a schematic perspective view of the bag of the invention, showing an enlarged view of one of the ends of the bag;

Figure 3 is a schematic side view of the bag of the invention, wherein the bag is in the vertical configuration;

Figure 4 is a schematic side view of the bag of the invention showing various angles of rotation of the bag with respect to the ground;

Figure 5 is a schematic side view of the bag of the invention in relation to a set of stairs;

Figure 6 is a schematic perspective view of an embodiment of the bag of the invention; Figure 7 is a schematic front view of one embodiment of a bag of the invention; Figure 8a and Figure 8b show a schematic side view of two embodiments of a bag in accordance with the invention; Figure 9 is schematic view of the bag from above, wherein the bag is in the open configuration;

Figure 10a and 10b show a schematic side and end view of the bag of the invention, wherein the bag is in the horizontal configuration; Figure 1 1 a and 1 1b show a schematic side and front view of the bag of the invention, wherein the bag is in the upright, vertical configuration;

Figure ! 2 is a schematic illustration of the bag of the invention, showing rotation of the bag as a user ascends and descends a set of stairs.

Referring to Figures 1 and 10, there is provided a bag (2) comprising a handle (4) and at least one wheel (6) to facilitate movement of the bag along a flat surface, wherein the handle (4) is rotatably attached to the bag (2) so that the bag (2) can move relative to the handle (4), and wherein the at least one wheel (6) does not interfere with movement of the bag (2) as it ascends and/ or descends an incline. Advantageously, when the user encounters a set of stairs he pulls the bag (2) via the handle (4) to move and slide the bag up and/ or down the stairs. Advantageously, the handle (4) rotates about an axis of rotation of the bag such that the angle of the handle with respect to the bag is adjusted to a position which reduces the force and thus the effort required to move the bag up and/ or down a set of stairs, In one embodiment, the handle may be attached to a central position on two sidewalls of the bag, wherein the handle can rotate through 360 degrees with respect to the central horizontal axis of the bag.

The bag comprises a body (5) having a front wall ( 10), a rear wall (12) and sidewalls ( 14) that extend peripherally to the front and rear walls, wherein the sidewalls of the bag support, the front and rear walls in spaced relation therewith. The front and rear walls have a greater surface area than the surface area of the sidewalls. The bag comprises four sidewalls, known as left, right, top and bottom sidewalls when the bag is in the upright, vertical configuration. In the embodiment wherein the bag is substantially rectangular, the upright, vertical configuration is achieved when the longitudinal axis of the bag is perpendicular to the surface of the ground.

In one embodiment, the handle (4) comprises two arms (4a) and a crossbar (4b). The two arms (4a) of the handle are substantially parallel to one another and the crossbar (4b) extends therebetween. The handle (4) is preferably attached to the bag via the arms (4a) and the user grips and pulls the handle (4) via the crossbar (4b). It is preferred that the handle (4) is attached to the bag at a distal end (7) of the arms (i.e. the end furthest from the user). It is further preferred that the handlebar extends between and joins the two amis of the handle at a proximal (9) end thereof (i.e. the end closest to the user).

The handle (4) is preferably attached to two parallel sidewalls (14) of the bag at a substantially central point on each sidewall (14). In one embodiment, the handle (4) may be attached to the bag (2) such that the axis of rotation of the handle may be provided along the central point of gravity of the bag. The user typically pulls and tows the bag via the crossbar (4b). As shown in Figure 1 , the handle can pivot around the point of attachment to the bag, and may rotate through 360 degrees with respect to the point of attachment of the handle to the bag.

Preferably, the bag (2) comprises two sets of wheels (6). In a preferred embodiment, the bag comprises four wheels, two wheels being provided at opposite ends of the bag. Advantageously, the wheels assist the movement of the bag along a surface. Each wheel is attached to the bag via an axel.

Each pair of wheels (6) is typically located at diagonally opposite ends of the bag, i.e. the bag comprises four wheels, two wheels being located at either end thereof. Advantageously, the provision of a pair of wheels (6) at opposite ends of the bag allows a user to rotate the bag through 180 degrees with respect to the central horizontal axis of the bag and then pull the bag along a surface via the wheels provided at the other end of the bag. The wheels (6) are preferably at least substantially flush with the front and/ or rear wall of the bag (2). Advantageously, providing the wheels such that they are substantially flush with the side of the front and/ or rear wall of the bag means that the wheels do not interfere with the sliding movement of the bag as the user moves the bag up and/ or down an incline. Figure 2 shows an embodiment of the bag (2) of the invention and includes an enlarged section illustrating the provision of a wheel (6) of the bag which is substantially flush with the rear wall (12) of the bag. Preferably, the bag comprises two sets of sliders (8), wherein one slider (8a) is attached to the front wall of the bag and one slider ( 8b) is attached to the rear wall of the bag (see, for example, Figure 10a). In one embodiment, the sliders (8a, 8b) comprise a plastics material.

Advantageously, the at least one slider facilitates smooth movement of the bag up and/ or down an incline such as a set of stairs. The provision of at least one slider also advantageously protects the outer surface of the bag from abrasion which may be caused by friction.

Preferably, the bag further comprises a gripper element (16) comprising a non-slip material. The non-slip material may be provided at regions of the bag adjacent to or opposite to the regions where the wheels are provided. Advantageously, the provision of a non-slip surface assists in rotation of the bag. In this embodiment, the non-slip material comprises rubber.

In a preferred embodiment, the bag is a suitcase and is substantially rectangular in shape. Preferably, the bag further comprises bevelled and/ or rounded corners (18). Advantageously, the provision of bevelled and/ or rounded corners allows for smooth movement of the bag up and/ or down a set of stairs since the bag is not caught on the angular portion of the steps. In addition, the provision of bevelled and/ or rounded comers advantageously enables the user to pull the bag at a range of angles to the ground.

Advantageously, the handle (4) comprises a ratchet mechanism to allow the user to control the angle of the handle relative to the central horizontal axis of the bag (2). Preferably, the bag further comprises releasable locking means (20) to lock the handle (4) in position, hi one embodiment, the releasable locking means comprises a ratchet style wheel to lock the handle in position. The provision of a releasable locking mechanism advantageously means that the handle can be fixed at a desired angle such that it will not rotate as the user pulls the bag along a surface. Advantageously, the provision of releasable locking means allows the lock to be released at a desired time, allowing the user to adjust the angle of the handle with respect to the central horizontal axis of the bag. The handle (4) preferably comprises a rigid material, and in one embodiment may comprise an aluminium alloy. The length of the handle (4) is adjustable via telescopic means to allow it to be extended and/ or retracted, hi one embodiment, the upper region (11) of an arm of the handle collapses and may be accommodated within the lower region (15) of an arm of the handle upon retraction thereof. In the embodiment where the handle is not in use, the handle is retracted and is wrapped around the outer surface of the bag. In the embodiment where the handle is in use, the handle is extended to assist the user in adjusting the position of the handle and/ or the bag.

Preferably, the front, rear and sidewalls of the bag may be substantially rigid and comprise layers of woven polypropylene fabrics, formed into self-reinforced composite sheets. Advantageously, such materials minimise the weight of the bag, whilst providing exceptional strength and resistance to impact, for example, at very low temperature.

Figure 3 illustrates an embodiment wherein the bag is stored in an upright, vertical configuration, wherein the longitudinal axis of the bag is substantially perpendicular to the ground. The provision of the bevelled ends of the bag and the wheel advantageously provide support for the end of the bag adjacent to and/ or in contact with the ground, allowing the bag to stand freely.

Figure 4 shows the bag of the invention wherein the handle has been locked in position. The ratchet mechanism may be used to lock the handle at a specific angle with respect to the central horizontal axis of the bag. The bag may be rotated through a range of angles with respect to the axis of the ground surface, such that the user can rotate the bag to a desired angle with respect to the ground surface to facilitate towing of the bag by a user. The preferred angle of the bag with respect to the ground surface (i.e. the angle at which the user achieve the optimum comfort when pulling the bag) will depend on a number of factors such as the height of the user, weight of the bag, etc.

Figure 5 shows the bag of the present invention in combination with a set of stairs (22). As the user ascends the stairs the handle of the bag is pulled such that the bag is towed and starts to ascend the stairs in direction X via a sliding movement. In this embodiment, the rear wall of the bag contacts the outer angular surface (22a) of the stairs. Advantageously, the bevelled ends

(18) of the bag and the positioning of the wheels (6) such that they are flush with the outer surface of the bag prevents the bag from becoming caught on successive steps, thus facilitating smooth movement of the bag up and/ or down the stairs.

When the bag is not in use, the handle may be adjusted such that its length is reduced. Thus, the handle of the bag may be extendable and/ or retractable. Figure 6 illustrates the embodiment wherein the handle of the bag is extended and the angle of the handle is adjusted with respect to the central horizontal axis of the bag. The angle of the handle with respect to the central horizontal axis of the bag is denoted in Figure 6 by a and in this embodiment is approximately 45 degrees to the central horizontal axis of the bag.

Figure 7 illustrates a front view of the bag, showing the point of attachment of the handle to the bag. In one embodiment, the bag comprises an inlay (24) to accommodate the handle when in the retracted configuration. Typically, the dimensions of the inlay are such that the handle may be securely held therein when not in use, i.e. the handle typically fits within the inlay and may be held such that it is flush against the sidewalls of the bag. The inlay (24) is typically provided within the sidewalls of the bag. In this embodiment, the action of pushing the handle downwards such that it moves from an extended configuration to a retracted configuration forces the sidewalls (14) of the bag to move inwards as shown by the arrows in Figure 7, thus assisting in positioning the handle within the inlay. This embodiment illustrates the handle when compressed, wherein the handle closes in around the bag and may be accommodated within the inlay such that it is held flush with respect to the sidewalls of the bag.

Figure 8a shows an embodiment wherein an inlay (24) is provided along the sidewalls of the bag. In the embodiment of Figure 8a, the inlay (24) extends along four sidewalls of the bag, extending diagonally across two parallel and opposite sidewalls of the bag. In the retracted position, the handle is accommodated within the inlay (24). In this embodiment, the handle is attached at a central point of the bag and may be fixed in position by a releasable locking mechanism (20) such as a ratchet lock. In this embodiment, an aperture (20a) is provided within a sidewall (14) to facilitate the attachment of the lock. An additional handle may be attached at one end of the bag, for example, at position denoted by B. The bag further comprises a closing means (26) such as a zip. The closing means typically extends around at least three of the sidewalls of the bag, such that the user can open the bag via the closing means and remove the contents of the bag therefrom. In this embodiment, the closing means extends in a direction parallel to the direction of the inlay (24). The bag may further comprise toggle latches (28) to assist in closing of the bag. Figure 8b shows another embodiment wherein the inlay (24) is provided along four of the sidewalls (14) of the bag. In this embodiment, the inlay (24) extends substantially parallel to the front and rear walls of the bag. The closing means (26) extends substantially parallel to the direction of the inlay. It will be understood that the inlay and closing means may be provided at a variety of angles across the sidewalls of the bag,

Figure 9 illustrates a view of the bag in the open configuration. In this embodiment, one of the sidewalls is attached to another wall of the bag via a hinging mechanism. Typically, the bag comprises a plurality of hinges (32), the hinges provided at the region where one sidewall joins the front or rear wall of the bag. Alternatively, the hinges may be provided along a central longitudinal axis of the sidewall, such that the sidewall is separated into two parts which are hinged together, such that the bag opens like a clam and is hinged at one of the sidewalls. Typically, the hinges may be provided on any one of the four sidewalls of the bag.

Figure 10a illustrates an embodiment of the bag, wherein the bag is in the horizontal configuration, i.e. wherein the longest wall of the bag is adjacent to and parallel to the ground surface. The wheels (6) are substantially flush with the front and rear walls of the bag such that they do not interfere with storage of the bag in this configuration. The front and rear walls of the bag comprise a slider (8a, 8b) comprising a plastics material, the slider providing a smooth surface to assist in movement of the bag up and/ or down an incline such as a set of stairs. The slider also protects the front and/ or rear walls from abrasion due to friction as the bag travels along a surface.

Figure 10b illustrates an end view of the bag in the embodiment shown in Figure 10a, Figure 1 1 a illustrates the embodiment wherein the bag comprises at least one gripper element (16) comprising a non-slip material. In this embodiment, the at least one gripper element is provided on two sidewalls (14) of the bag, at the upper and lower end when the bag is in the vertical configuration. Typically, the gripper element is provided on the top and bottom sidewalls of the bag. The gripper element may be provided adjacent the longitudinal axis of the bag, at a position of the sidewall opposite to the position at which the pair of wheels is provided. The non-slip material allows the bag to grip the ground surface to initiate rotation of the bag. When the handle is not in use it may be wrapped around the outer surface of the bag, as shown in Figure 1 1b. In this embodiment it can also be seen that the wheels are substantially flush with the outer surface of the front and rear walls of the bag.

Figure 12 illustrates the mechanism by which the bag is moved up and then down a set of stairs. In this embodiment, the two ends of the bag are denoted (A) and (B) to illustrate the rotation of the bag as the user ascends and descends a set of stairs. Initially, the user rotates the handle (4) to a desired angle with respect to the central horizontal axis of the bag (2) and then locks the handle (4) in position via the releasable locking mechanism. The releasable locking mechanism comprises a ratchet mechanism and may be controlled (i.e. activated and/ or deactivated) by a lever provided on the handle (4). The user then pulls the handle via the handlebar (4b) to tow the bag along a surface via the wheels (6). When the user approaches a set of stairs (22), the locking mechanism is released and the angle of the handle with respect to the central horizontal axis of the bag is adjusted as desired. The user then pulls the bag via the handle as he starts to climb the stairs. In this embodiment, the rear wall of the bag contacts the outer angular surface of the stairs. The slider (8b) provided on the rear wall of the bag assists in movement of the bag up the stairs, providing a substantially smooth surface which minimises friction. As the user reaches the top of the stairs, the user adjusts the position of the bag such that the non-slip surface contacts the ground and initiates rotation of the bag. The bag then rotates through approximately 180 degrees with respect to the central horizontal axis of the handle. The user then adjusts the angle of the handle with respect to the central horizontal axis of the bag and then pulls the bag down the set of stairs using the handle as a guide. When descending the stairs, the user may control the position of the bag from in front or behind the bag. At the bottom of the stairs, the bag is rotated and the handle is adjusted to a desired angle to facilitate movement of the bag along the ground. The handle is then locked in position and the user then pulls the bag along the surface of the ground.

As shown in Figure 12, at step (a) the bag is locked at comfortable elevation at the point of rotation. The locking mechanism is controlled by a lever provided at the handle, wherein the locking mechanism may be in two modes, i.e. free or locked. At step (b), the user releases the lock on rise of stairs, allowing the bag to freely assume the incline of the stairs. The user may also release the lock at step (a). The bag rotates. At step (c), the user begins the rotational process on reaching the top of the stairs and the bag is in the "free to rotate mode". At step (d), on descent, the user again has the bag in the "free to rotate mode" so that it again assumes the inclination of the stairs. The user controls the descent from either in front or behind the bag. At step (e), the user begins the rotational process on reaching the bottom of the stairs and the bag is in the "free to rotate mode". At step (f), the bag is eventually locked after rotation at the most comfortable pulling angle for the user. The two ends points of the bag are denoted (A) and (B) to help illustrate rotation of the bag as it moves up and down a set of stairs. The direction of travel of the bag is illustrated by the arrow (Y). Reference numeral (i) illustrates the smooth bevelled corners which prevent the bag from jamming on successive steps. Reference numeral (ii) shows the non-slip material catches which allows the bag to grip the ground and initiate rotation. The direction of rotation of the bag is indicated by reference numeral (iii).