Footwear

Abstract

Footwear 10 convertible between an elevated state and a lowered state, the footwear comprising an adjustable heel 12 movable between a deployed position where the footwear is in the elevated state, an

Description

FIELD The present teachings relate to footwear, in particular but not exclusively to a shoe, convertible between an elevated state and a lowered state. BACKGROUND It is known for shoes, in particular women's shoes, to be designed with an elevated or high heel. As well as increasing the apparent height of the wearer, such a high heel increases design options, and is thought to provide a more formal style. Such high-heeled shoes can be uncomfortable, in particular when worn for a long period of time. This is a particular issue with stiletto or slim-heeled shoes, commonly the highest-heeled shoes, which are often the most uncomfortable in which to walk, due to the slim heel and forced arch. Because of this, it is common for the wearers of high-heeled shoes to travel with an additional pair of flat or lower-heeled shoes, to provide the option of changing footwear due to discomfort, or to undertake some activity such as walking longer distances or driving a vehicle. However, it can be inconvenient to carry a second pair of shoes, and it may not be an option - for example, due to spontaneity, or the lack of a suitable carrying means. It is known to address this problem with a shoe that can be worn as a high-heeled or elevated shoe, and as a low-heeled or lowered shoe, with an adjustable high heel that allows conversion between the two states. The adjustable heel may be detachable, and may be replaced with a lower heel. However, such a design leaves the wearer carrying the detached heel. An alternative is a shoe with a pivotable heel which remains attached to the sole of the shoe when the shoe is in the lower-heeled state. It can be difficult to incorporate the necessary pivoting arrangement within the shoe whilst maintaining a stylish design. A latch mechanism is commonly required to secure the pivotable heel in place, which again can be difficult to incorporate into the shoe given the limited space available, and can negatively affect the aesthetic design of the shoe. The requirements for the sole of a shoe vary depending on whether the shoe is high-heeled or low-heeled, as the position of the wearer's foot is different in each case. Where a shoe is convertible between elevated and lowered states, if the wearer's foot is to be properly supported by the sole, the sole must adapt as the shoe is converted between states. In particular, the required angle of the relative parts of the sole changes depending on whether such a shoe is elevated or lowered. A steeper angle is required between the toe of the sole and the heel of the sole in a higher-heeled shoe. It is known to adjust the sole of a convertible shoe when the shoe is converted between elevated and lowered states. However, known arrangements for adjusting the sole can also negatively affect the aesthetic design of the shoe, and can be awkward and timeconsuming for the wearer to operate. The present teachings seek to overcome or at least mitigate the problems of the prior art. SUMMARY According to a first aspect of the present teachings there is provided footwear convertible between an elevated state and a lowered state, the footwear comprising an adjustable heel, wherein the adjustable heel is movable between a deployed position, where the footwear is in the elevated state, and a stowed position, where the footwear is in the lowered state; a sole of adjustable angle; and a sole adjustment arrangement configured to adjust the angle of the sole. The sole adjustment arrangement is configured to be operated by movement of the adjustable heel between the deployed position and the stowed position. The sole adjustment arrangement being activated by movement of the adjustable heel between the deployed position and the stowed position allows the sole angle to be automatically adjusted as the footwear is converted between the elevated and lowered states. The wearer can convert the footwear with a single operation, saving time and effort, and the adjustable angle of the sole ensures that the footwear fits the wearer in the elevated and lowered states. In exemplary embodiments, at least part of the movement of the adjustable heel between the deployed position and the stowed position is pivotable movement. Pivoting movement of the heel facilitates simultaneous adjustment of the sole length, and is a simple and effective method of converting the footwear. In exemplary embodiments, the footwear further comprises a pivotable joint between the adjustable heel and the footwear, wherein the sole adjustment arrangement is configured to be operated by movement of the pivotable joint upon pivoting of the adjustable heel between the deployed position and the stowed position. The pivotable joint between the adjustable heel and the footwear being used to provide adjustment of the sole angle ensures that the sole angle is adjusted simultaneously with movement of the adjustable heel between the deployed and stowed positions. In exemplary embodiments, the sole adjustment arrangement comprises a body connected to the sole, and the body is arranged in rotatable connection with the pivotable joint, such that movement of the pivotable joint is configured to rotate the body such that the angle of the sole is adjusted. In exemplary embodiments, the sole adjustment arrangement further comprises at least one arm extending from the body, wherein the or each arm is connected to the sole. This sole adjustment arrangement advantageously makes use of the pivotable movement to adjust the sole angle, leading to a compact and effective adjustment arrangement. In exemplary embodiments, the body is rotatable between a first position, where the sole is adjusted to an angled state and a second position, where the sole is adjusted to a flatter state. In exemplary embodiments, when the adjustable heel is in the deployed position, the body is in the first position, and when the adjustable heel is in the stowed position, the body is in the second position. The rotatable body being movable between first and second positions allows the sole to be adjusted between two predetermined lengths, to correspond with the required adjustment in sole angle when the footwear is converted between elevated and lowered states. When the footwear is in an elevated state, the required sole angle is decreased, and the body is accordingly in the first position. When the footwear is converted to a lowered state, the required sole angle is increased, and the body is accordingly moved to the second position. In exemplary embodiments, movement of the pivotable joint is configured to result in lesser rotational movement of the body. In exemplary embodiments, the body is arranged in rotatable connection with the pivotable joint in a lost motion arrangement. The lost motion arrangement allows the pivoting movement of the adjustable heel to result in the required lesser movement of the sole adjustment arrangement. In exemplary embodiments, the body defines a sleeve, wherein the pivotable joint comprises a shaft from which the adjustable heel extends, wherein the adjustable heel is rotatable about the shaft, wherein the sleeve defines an aperture, and wherein the sleeve is arranged about the shaft such that the shaft extends through the sleeve, and the adjustable heel extends through the aperture, such that engagement of the adjustable heel with an edge of the aperture upon pivoting of the adjustable heel about the shaft is configured to rotate the body about the shaft. In exemplary embodiments, when the adjustable heel is to be pivoted from the deployed position to the stowed position, the adjustable heel is configured for a first stage of pivoting away from a toe of the footwear. In exemplary embodiments, the adjustable heel is configured for a second stage of pivoting towards said toe. Movement of the adjustable heel away from the toe of the footwear in the first instance moves the body of the sole adjustment arrangement in a direction such that the sole is adjusted to the required flatter state as the footwear is converted to a lowered state. In exemplary embodiments, when the adjustable heel is to be pivoted from the stowed position to the deployed position, the adjustable heel is configured for a third stage of pivoting away from a toe of the footwear. In exemplary embodiments, the adjustable heel is configured for a fourth stage of pivoting towards said toe. The adjustable heel is thus moved beyond the deployed position in a movement away from the toe, before being moved to the deployed position in the fourth stage of pivoting. This fourth stage of pivoting moves the body of the sole adjustment arrangement in a direction such that the sole is adjusted to the required angled state as the footwear is converted to an elevated state. In exemplary embodiments, the adjustable heel is pivotable between the deployed position and the stowed position about a transverse axis of the footwear, perpendicular to a longitudinal axis of the footwear. The adjustable heel being pivotable about an axis perpendicular to the longitudinal axis of the footwear allows the pivoting movement of the adjustable heel to be used to adjust the angle of the sole, allowing a compact sole angle adjustment arrangement. In exemplary embodiments, the sole comprises a toe portion and a heel portion, wherein the toe portion and the heel portion are adjustable with respect to one another, and wherein the sole adjustment arrangement is configured to adjust the position of the toe portion and the heel portion with respect to one another along a longitudinal axis of the footwear so as to adjust the sole angle. Adjusting toe and heel portions of the sole is a simple means of adjusting the overall sole angle and allows sole angle adjustment to be carried out by pivoting of the adjustable heel. The pivoting movement of the adjustable heel is efficiently translated into lengthwise adjustment of the sole portions with respect to one another. In exemplary embodiments, the sole adjustment arrangement is connected to the toe portion, such that the sole adjustment arrangement is configured to adjust the position of the toe portion. The sole adjustment arrangement being configured for adjustment of the toe portion allows effective adjustment of the overall angle of the sole. In exemplary embodiments, the sole comprises a detent mechanism between the heel portion and the toe portion. The detent mechanism inhibits unwanted adjustment of sole angle once the footwear is in the elevated or lowered position, and improves location of the heel and toe portions in relation to one another. In exemplary embodiments, the footwear further comprises a latch configured to latch the adjustable heel in the deployed position. The use of a latch to secure the adjustable heel in the deployed position ensures that the adjustable heel will not be moved from the deployed position unless the wearer wishes to convert the footwear to the lowered state. In exemplary embodiments, the latch comprises a push-button release. The push-button release is easily operated, and allows the footwear to be converted between states whilst remaining on the foot of the wearer. There is also provided footwear convertible between an elevated state and a lowered state, the footwear comprising an adjustable heel, pivotable between a deployed position, where the footwear is in an elevated state, and a stowed position, where the footwear is in a lowered state; wherein the adjustable heel comprises a heel extension and a connection member; wherein the connection member is configured to pivotably connect the adjustable heel to the footwear at a pivotable joint, such that the adjustable heel is pivotable in relation to the footwear about a transverse axis of the footwear; wherein the connection member defines a longitudinal axis; and wherein the heel extension is rotatable about the connection member longitudinal axis between a first orientation, in which the adjustable heel can be pivoted to the deployed position, and a second orientation, in which the adjustable heel can be pivoted to the stowed position; and wherein, when the adjustable heel is in the deployed position, the adjustable heel is configured for a first stage of pivoting about the pivotable joint, away from a toe of the footwear, such that the heel extension can be rotated to the second orientation. Allowing a change in orientation of the adjustable heel between the deployed and stowed positions increases design options, and can lead to the creation of a more stylish footwear. Pivoting of the adjustable heel away from the toe of the footwear to provide clearance for a change in orientation is easy for a wearer to carry out, and allows for a simple and effective pivoting mechanism. In exemplary embodiments, the footwear further comprises a fixed heel, wherein the adjustable heel is pivotable with respect to the fixed heel, and wherein the pivotable joint is located within the fixed heel. The pivotable joint being located within the fixed heel enables the pivotable joint to be hidden from view, improving the aesthetic appeal of the footwear design. In exemplary embodiments, when the adjustable heel is in the stowed position, the fixed heel is exposed, such that the fixed heel is configured for contact with a ground surface. Advantageously, the provision of a fixed heel suitable for contact with the ground means that no additional detachable low heel is required when the footwear is in the lowered state. In exemplary embodiments, the heel extension defines a longitudinal axis, the longitudinal axis being substantially coincident with and normal to the transverse axis of the pivotable joint in the deployed position. This arrangement minimises eccentric loads on the mechanism. In exemplary embodiments, the heel extension defines a longitudinal axis, and the angle between the heel extension longitudinal axis and the connection member longitudinal axis is between 90° and 150°. In exemplary embodiments, the angle between the heel extension longitudinal axis and the connection member longitudinal axis is between 110° and 130°. This angle between the heel extension and the connection member enables the adjustable heel to support the weight of the wearer on a thin stiletto heel. In addition, this angle between the heel extension and the connection member allows the heel extension to be neatly stored close to the sole of the footwear when the adjustable heel is in the stowed position. The angle is such that, when the adjustable heel is in the stowed position, the heel extension is kept away from the ground, improving ease of movement for the wearer and reducing the likelihood of the heel extension becoming dirtied. In exemplary embodiments, when the adjustable heel is to be pivoted from the stowed position to the deployed position, the adjustable heel is configured for a third stage of pivoting about the pivotable joint away from a toe of the footwear. In exemplary embodiments, the adjustable heel is configured for a fourth stage of pivoting about the pivotable joint towards said toe. The adjustable heel is thus moved beyond the deployed position in a movement away from the toe, before being moved to the deployed position in the fourth stage of pivoting. This fourth stage of pivoting moves the body of the sole adjustment arrangement in a direction such that the sole is adjusted to the required angled state as the footwear is converted to an elevated state. In exemplary embodiments, the heel extension is configured for rotation of between 170° and 190° between the first orientation and the second orientation. Such rotation of the heel extension allows the adjustable heel to be of a stylish design that can provide suitable support to the heel of the footwear, and to be stowed neatly beneath the sole of the footwear. In exemplary embodiments, the footwear further comprises a latch configured to latch the adjustable heel in the deployed position. The use of a latch to secure the adjustable heel in the deployed position ensures that the adjustable heel will not be moved from the deployed position unless the wearer wishes to convert the footwear to the lowered state. In exemplary embodiments, the latch is operable between a first, closed, position, where the first stage of pivoting of the adjustable heel is prevented, and a second, open position, where the first stage of pivoting of the adjustable heel is enabled. The latch blocking movement of the adjustable heel from the deployed position is a simple and effective method of securing the adjustable heel in the deployed position. In exemplary embodiments, the latch comprises a resilient biasing mechanism, configured to bias the latch towards the closed position. In exemplary embodiments, the latch comprises a push-button release. Advantageously, the latch being biased towards a closed position leads to the adjustable heel being automatically secured when in the deployed position. The push-button release is easily operated, and allows the footwear to be converted between states whilst remaining on the foot of the wearer. In exemplary embodiments, the footwear further comprises a sole of adjustable angle; and a sole adjustment arrangement configured to adjust the angle of the sole; wherein the sole adjustment arrangement is configured to be operated by pivoting of the adjustable heel between the deployed position and the stowed position. BRIEF DESCRIPTION OF THE DRAWINGS Embodiments will now be described, by way of example only, with reference to the accompanying figures, in which: Figure 1 is an isometric view of a sole and heel of a convertible shoe in an elevated state according to an embodiment; Figure 2 is an isometric view of an adjustable heel of the shoe of Figure 1 with some parts removed for clarity; Figure 3 is a vertical cross-sectional view through the shoe of Figure 1 on a longitudinal centreline thereof, and including an upper of the shoe; Figure 4a is a plan view of a sole of a shoe of Figure 1 when the shoe is in a lowered state; Figure 4b is a cross-sectional view through the sole of Figure 4a on the plane Y-Y; Figure 4c is an exploded view of the cross-section of Figure 4b; Figure 5 is a cross-sectional view through the shoe of Figure 1 after a first stage of pivoting of the adjustable heel; Figure 6 is a cross-sectional view through the shoe of Figures 1 and 5 during a second stage of pivoting of the adjustable heel; Figure 7 is a cross-sectional view through the shoe of Figures 1, 5 and 6 after the second stage of pivoting of the adjustable heel; Figure 8 is a side view of the shoe of Figures 1, 5, 6 and 7 after the second stage of pivoting in the lowered state; Figure 9 is a rear view of the shoe of Figure 1; Figure 10a is a cross-sectional view through the shoe of Figure 1 showing a latch mechanism in a first position; and Figure 10b is a cross-sectional view through the shoe of Figure 1 showing the latch mechanism of 10a in a second position. DETAILED DESCRIPTION OF EMBODIMENT(S) With reference to Figure 1, a sole and heel of a footwear article in the form of a convertible shoe are indicated generally at 10. In Figure 1, some upper parts of the sole have been removed to improve clarity. The shoe 10 is convertible between an elevated state and a lowered state. In Figure 1, the shoe is shown in the elevated state. The shoe 10 has an adjustable heel 12. The adjustable heel 12 allows the conversion of the shoe 10 between the elevated and lowered states. The adjustable heel 12 is pivotable between a deployed position, as shown in Figure 1, where the shoe is in an elevated state, and a stowed position, as shown in Figure 8 and described in further detail below, where the shoe is in a lowered state. Where reference is made to movement of the adjustable heel between the deployed position and the stowed position, movement in either direction is included. That is, movement from the deployed position to the stowed position, and movement from the stowed position to the deployed position. Where movement is in a particular direction, i.e., from the deployed to the stowed position, or from the stowed position to the deployed position, this will be made clear. The shoe 10 has a sole 14 (see Figures 4a, 4b and 4c), the angle of which is adjustable. That is, the relative angle of different portions of the sole can be varied to provide support to the wearer's foot when the shoe 10 is in the elevated or lowered state, as described in further detail below. The shoe 10 has a sole adjustment arrangement 16 by which the angle of the sole 14 can be adjusted. The sole adjustment arrangement 16 is operated by pivoting of the adjustable heel 12 between the deployed position and the stowed position, in both directions. Advantageously, the angle of the sole is adjusted automatically when the shoe is converted between elevated and lowered states. The wearer of the shoe, who is assumed to be the person converting the shoe between states, is able to convert the shoe with simultaneous adaptation of sole angle in a single operation. There is no need for separate adjustment of the heel 12 and the sole 14 of the shoe 10 as it is converted between the elevated and lowered states. The adjustable heel 12 is connected to the shoe at a pivotable joint 18, as shown in Figures 2 and 3. The pivotable joint 18 allows pivoting of the adjustable heel 12 between the deployed position and the stowed position. The sole adjustment arrangement 16 is operated by movement of the pivotable joint 18 as the adjustable heel 12 is moved between the deployed position and the stowed position. In this way, the angle of the sole 14 is adjusted as the adjustable heel 12 is moved between the deployed position and the stowed position. The sole adjustment arrangement 16 has a body 20 connected to the sole 14. In this embodiment, the body takes the form of a sleeve 20. The body 20 is arranged in rotatable connection with the pivotable joint 18. That is, the body 20 is arranged such that pivoting movement of the joint 18 results in rotation of the body 20. As the body 20 is connected to the sole 14, rotation of the body 20 leads to adjustment of the angle of the sole 14 by virtue of relative longitudinal movement of parts of the sole as described below. The pivotable joint 18 is pivotable about an axis y transverse to the longitudinal axis x of the shoe. Pivoting of the joint 18 about the axis y results in rotation of the body 20 about the axis y, and so can provide adjustment of the length of the sole 14 in the direction of the longitudinal axis x. In this embodiment, the sole adjustment arrangement 16 includes a pair of arms 22 extending in a parallel direction from the body 20 to connect the body to the sole 14. The arms 22 each define a bore 24. The bores 24 are co-axial. A pin 26 is received in both bores 24, so that the pin 26 extends between the arms 22. The pin 26 extends through a connection end 28 of the sole (see Figure 4a) to attach the sole 14 to the sole adjustment arrangement 16. In this embodiment, the connection end 28 defines a loop 29 positioned between the arms 22. The pin 26 extends through the loop 29 to secure the connection end 28 to the body 20. The pin 26 extending through the connection end 28 of the sole 14 allows the sole adjustment arrangement 16 to move the sole 14 in both directions along the longitudinal axis x, i.e., in a forwards direction, towards a toe 30 of the shoe, and in a rearwards direction, away from the toe 30. The body 20 is rotatable between a first position, where the sole 14 is adjusted to an angled state and a second position, where the sole 14 is adjusted to a flatter state. The body 20 is shown in the first position in Figures 2 and 3, where the arms 22 are rotated rearwardly, away from the toe 30. As shown in Figure 4a, the connection end 28 of the sole 14 to which the sole adjustment arrangement 16 is attached is part of a toe portion 32 of the sole 14. Movement of the connection end 28 with the sole adjustment arrangement 16 therefore results in movement of the toe portion 32 along the longitudinal axis x. The sole 14 is flexible, such that movement of the connection end results in tensioning and release of the sole 14, so adjusting the sole 14 between the angled state and the flatter state. When the body 20 is in the first position, shown in Figures 2 and 3, the arms 22 are rotated rearwardly, and so the toe portion 32 is held rearwardly along the longitudinal axis x, i.e., relatively closer to a heel portion 34 of the sole 14. The sole 14 is thus adjusted to an angled state, with the heel portion 34 inclined at an angle f in relation to the toe portion 32. This angle, as can be seen from Figure 3, corresponds to the shoe 10 being in an elevated state, with the adjustable heel 12 in the deployed position. The sole 14 is thus adapted to the desired angled state when the shoe 10 is in the elevated state. Figure 7 shows the body 20 in the second position, where the sole 14 is adjusted to the flatter state, and where the angle f between the heel portion 34 and the toe portion 32 is reduced in comparison to the angled state. As shown in Figure 7, when the body 20 is in the second position, the arms 22 are in a relatively forward position, i.e. towards the toe 30. The sole 14 is shown in the flatter state in Figures 4a, 4b and 4c, where it can be seen that the connection end 28 is moved towards the toe 30, and the toe portion 32 of the sole is extended away from the heel portion 34. As shown in Figure 7, where the adjustable heel 12 is in the stowed position, this second position of the body 20 and thus likewise the arms 22 corresponds to the shoe 10 being in the lowered state. In this lowered state, the flatter state of the sole 14 is required to comfortably support the foot, and the body 20 is in the second position as set out above. With reference to Figure 2, the pivotable joint 18 of this embodiment has a rotatable shaft 36 supported by bearings (not shown). The shaft 36 extends along the transverse axis y. The adjustable heel 12 extends from the shaft 36, and so is pivotable about the axis y. The body 20 of the sole adjustment arrangement 16 is in this embodiment arranged about the shaft 36. That is, the body 20 defines a bore 38 through which the rotatable shaft 36 extends. As shown in Figure 9, the body 20 defines an aperture or slot 21 extending partway around the circumference of the body 20, through which the adjustable heel 12 extends. Upon movement of the adjustable heel 12 about the axis y in either direction, the adjustable heel 12 connects with an edge of the slot, and so rotates the body 20 as the adjustable heel 12 pivots. The slot has a circumferential length greater than the width of the adjustable heel 12, such that the body 20 has a lost motion relationship with the pivotable joint 18. That is, the adjustable heel 12 can be moved some distance before meeting an edge of the slot, depending on the position of the body 20 and the direction of movement of the adjustable heel 12, as described in further detail below. That is, the body 20 does not always move as the adjustable heel 12 is pivoted, and does not necessarily move the same distance as the adjustable heel 12. The rotation of the arms 22 that is required to adjust the angle of the sole between the angled state and flatter state is less than the distance through which the adjustable heel 12 is pivoted during conversion between the deployed and stowed positions. In addition, rotation of the arms 22 between the first and second positions is not required at every stage of pivoting of the adjustable heel 12, as described in further detail below. This arrangement of the sole adjustment arrangement 16 and the pivotable joint 18 is advantageously compact and can be concealed within the heel of the shoe 10, allowing for a stylish shoe design. The toe portion 32 and the heel portion 34 of the sole are shown in detail in the exploded view of Figure 4c. In addition to the connection end 28, the toe portion 32 has an undersole 48 and a midsole 50. The heel portion 34 has an upper layer 52 and a lower layer 54. The upper and lower layers 52, 54 of the heel portion 34 overlie the heel of the shoe 10, and are secured to one another around their respective perimeters. The heel portion 34 is fixed in relation to the heel 11 of the shoe 10. The heel portion 34 defines an aperture 56 (see Figure 4a) arranged to allow movement of the sole adjustment arrangement 16. The sole adjustment arrangement 16 is located at the heel 11 of the shoe 10 such that the arms 22 correspond to the aperture 56. The aperture 56 allows movement of the arms 22 between the first and second positions. In this embodiment, the connection end 28 is an end of a connection member 58 that secures the connection end 28 to the remainder of the toe portion 32, i.e. to the midsole 50 and the undersole 48. The connection member of this embodiment takes the form of a strip 58 that runs between the upper and lower layers 52, 54 of the heel portion 34, and is moveable in relation to the heel portion 34. The sole 14 has a rigid outer (lower) layer 79 in the heel portion thereof in this embodiments. The outer layer 79 is moulded, and in this embodiment is of carbon fibre. In alternative embodiments, the outer layer 79 is of other suitable material such as ABS or other rigid plastics, or fibre reinforced plastics, such as glass fibre. In an exemplary embodiment (not shown), the upper side of the outer layer defines a slot through which the strip extends. In such an embodiment, the strip is slidable in relation to the slot. The slot serves to guide sliding of the strip in relation to the outer layer 79 and the remainder of the sole 14. The sole 14 has a location arrangement 60, 62a, 62b in order to locate the toe portion 32 and the heel portion 34 with respect to one another. The strip 58 has a protrusion 60 for locating the strip 58, and so also the toe portion 32, in relation to the heel portion 34 and the remainder of the shoe 10. The heel portion 34 defines a pair of recesses 62a, 62b. Each recess 62a, 62b is configured to receive the protrusion 60, in order to locate the toe portion 32 in relation to the heel portion 34 and act as a form of detent mechanism. The first recess 62a is distal the toe 30, and is intended to receive the protrusion 60 when the sole 14 is at the shorter length, i.e., when the body 20 is in the first position, and the toe portion 32 is in its rearward position. The second recess 62b is proximal the toe 30, and is intended to receive the protrusion 60 when the sole 14 is in the longer position, i.e., when the body 20 is in the second position, as shown in Figures 4a, 4b and 4c. In this embodiment, each recess 62a, 62b is defined by both of the upper and lower layers 52, 54. In this embodiment, the protrusion 60 is a cylindrical bar. Each of the upper and lower layers 52 and 54 of the heel portion 34 defines a pair of semi-circular recesses aligned with the semi-circular recess of the other of the upper and lower layers 52, 54, such that recesses 62a, 62b of a circular cross-section are formed. The recesses 62a, 62b are thus conformed to receive the cylindrical bar 60. In this embodiment, the bar 60 and the recesses 62a, 62b extend parallel to the axis y. As the sole 14 is adjusted between the angled state and the flatter state the bar 60 is moved between the first and second recesses 62a, 62b. This facilitates the flattening of the toe portion as illustrated in Figures 7 and 8, so the shoe 10 adopts a suitable form to comfortably fit the wearer's foot in its low heeled state. In alternative embodiments, no such location arrangement is provided. In alternative embodiments, an alternative location means between the toe portion and the heel portion is provided. As shown in Figure 3, the shoe 10 has an upper 13. The upper 13 is adjustable with the sole 14 as angle of the sole 14 is changed. The upper 13 of this embodiment has a resilient portion 15 on each side of the shoe 10. In this embodiment, the resilient portion is in the form of two v-shaped inserts 15 of resilient material. The inserts 15 allow expansion and contraction of the upper 13 with the sole 14 as the sole is lengthened and shortened respectively (compare Figure 3 with Figure 8, in which the shoe 10 is in its lowered state). In an alternative embodiment, the resilient portion is in the form of a single v-shaped insert of resilient material. In an alternative embodiment, the upper has on each side of the shoe an overlapping portion, where heel and toe portions of the upper meet and are movable in relation to one another as the angle of the sole is changed. The adjustable heel 12 of this embodiment has a heel extension 40, shown in Figure 3. The heel extension 40 provides the required additional height to the shoe 10 when the shoe 10 is in the elevated state. That is, the heel extension 40 supports a heel 11 of the shoe and raises the heel 11 of the shoe from the ground when the shoe 10 is in the elevated state. In this embodiment, the heel extension 40 is arranged such that, when the adjustable heel 12 is in the deployed position, some or all of the weight of the wearer is transmitted through the heel 11. The remainder of the weight of the wearer is transmitted through the pivotable joint 18. The adjustable heel 12 has a connection member 42, by which the heel extension 40 is connected to the pivotable joint 18. The connection member 42 is in this embodiment a rod 42. The rod 42 is fixed to the shaft 36. The rod 42 extends through the slot of the body 20, and acts on the body 20 as described above. In this embodiment, the rod 42 is fixed to the shaft 36 such that a longitudinal axis z of the rod 42 is perpendicular to the longitudinal axis y of the shaft 36. In this embodiment, the heel extension 40 is rotatably fixed to the rod 42 such that the heel extension 40 is rotatable about the axis z of the rod 42. In alternative embodiments, the rod has a rotatable connection with the shaft, and is fixed with respect to the heel extension, such that the heel extension and the rod are rotatable together about the axis z in relation to the shaft. With reference now to Figures 3, 5, 6 and 7, pivoting of the adjustable heel 12 between the deployed position and the stowed position will be described in further detail. The heel extension 40 has a first orientation, in which the adjustable heel 12 can be deployed, and a second orientation, in which the adjustable heel 12 can be stowed. In order to move the adjustable heel 12 from the deployed position shown in Figure 3 to the stowed position, shown in Figure 7, the adjustable heel 12 is pivoted in first and second stages about axis y. During pivoting of the adjustable heel 12, the heel extension 40 is rotated between the first and second orientations about axis z. In the first stage of pivoting, the adjustable heel 12 is pivoted rearwardly, away from the toe 30, as indicated in Figure 3 by arrow a. In the first stage of pivoting, the adjustable heel 12 is pivoted to the rear of the shoe 10, beyond the heel 11, to a heel clearance position as shown in Figure 5. In this embodiment, the adjustable heel 12 is pivoted about the axis y through an angle e of around 125° from the deployed position to the heel clearance position of Figure 5. In alternative embodiments, the adjustable heel 12 is pivoted about the axis y through an angle of between 50° and 180°, or through an angle of between 100° and 150°. When in the heel clearance position of Figure 5, the adjustable heel 12 is clear of the heel 11, such that the heel extension 40 can be rotated about the axis z without rotation being inhibited by the heel 11. In this embodiment, the heel extension 40 has a first end 40a by which the heel extension 40 is connected to the pivotable joint 18 via the rod 42, and a second, free end 40b, intended for supporting contact with the ground. In this embodiment, the first end 40a is at an obtuse angle to the second end 40b. In this embodiment, the angle d (see Figure 5) between the first end 40a and the second end 40b is 120°. This angle between the first end 40a and the second end 40b enables the adjustable heel 12 to provide proper support for the heel 11, and allows the heel extension to be pivoted clear of the heel 11 during the first stage of pivoting, such that the heel extension 40 can be rotated about the axis z. In alternative embodiments, the angle d is between 90° and 150°. During the first stage of pivoting, as can be seen in Figure 5, the rod 42 contacts a rearward edge 23 of the slot and thereby rotates the body 20 to the second position. The sole 14 is thus adjusted to the flatter state as described above. During the first stage of pivoting, the heel extension 40 remains in the first orientation. After the first stage of pivoting, and before the second stage of pivoting, the heel extension 40 is rotated through 180° about the z axis, to the second orientation, as shown in Figure 6. The adjustable heel 12 is then in a position for pivoting about the axis y in the direction of arrow b during the second stage of pivoting, as shown in Figure 6. Figure 7 shows the adjustable heel 12 in the stowed position, having been pivoted at the axis y in the second stage of pivoting until the free end 40b meets, and is restrained against the sole 14. As shown in Figure 7, the arms 22 remain in the second, forward, position during the second stage of pivoting. In the second stage of pivoting, the rod 42 moves through the slot of the body 20. The slot is of a length such that during the second stage of pivoting, the rod 42 does not come into contact with a forward edge of the slot, and so the body 20 is not moved from the second position. The sole 14 thus remains at the appropriate flatter state. Figure 8 shows the shoe 10 in a lowered state, with the adjustable heel 12 in the stowed position. As shown in Figure 8, the heel 11 has a heel tip 44 that is exposed after stowing of the adjustable heel 12. The heel tip 44 is intended for contact with the ground, so that the shoe 10 is comfortable in the low heel position, and the heel 11 is protected from wear. The heel tip 44 is fixed in relation to the heel 11, and is arranged such that the adjustable heel 12 is pivotable past the heel tip 44. The heel tip 44 of this embodiment has two portions 44a, 44b, as seen in Figure 10a. The heel tip portions 44a, 44b are separated from one another to allow pivoting of the adjustable heel 12 between the heel tip portions 44a, 44b. As shown in Figure 1, the shoe 10 has a recess 46 defined by the underside of the sole 14. The recess 46 receives the free end 40b of the heel extension when the adjustable heel 12 is in the stowed position, and is suitably retained. In order to move the adjustable heel 12 from the stowed position to the deployed position, the free end 40b is released from the recess 46. In a third stage of pivoting, the adjustable heel 12 is pivoted in the direction of axis y beyond the deployed position, i.e., beyond the heel 11, until the adjustable heel 12 is in the heel clearance position. That is, the adjustable heel 12 is positioned such that there is clearance for the heel extension 40 to be rotated about the rod 42. The heel extension 40 is rotated 180° throughout the axis z from the second orientation to the first orientation. A fourth stage of pivoting then takes place, such that the adjustable heel 12 is pivoted about the axis y in the direction b until it is in the deployed position, as shown in Figure 3. The adjustable heel 12 has a latch 70, shown in Figures 2, 10a and 10b. The latch 70 retains the adjustable heel 12 in the deployed position. The latch 70 has a latch member 72 arranged to prevent movement of the adjustable heel 12 when the adjustable heel 12 is in the deployed position. The latch member 72 of this embodiment has protrusions 74 that prevent movement of the adjustable heel 12 from the deployed position when the latch 70 is in a first, closed position. As shown in Figure 2, the end 40a of the adjustable heel 12 connected to the pivotable joint 18 has a forked end 76 that extends beyond the pivotable joint 18. The forked end 76 is aligned with the protrusions 74 when the latch member 72 is in the first, closed position, such that pivoting of the adjustable heel 12 about the axis y is prevented. In order for pivoting of the adjustable heel 12 to take place, the latch 70 must be moved to a second, open position. Figure 10a shows the latch 70 in the closed position, where the protrusions 74 block the forked end 76 and so prevent pivoting of the adjustable heel 12. Figure 10b shows the latch in the open position. In order to move the latch 70 to the open position, the latch member 72 is pushed along its longitudinal axis towards the shoe 10, in the direction c. Movement in this direction moves the protrusions 74 with respect to the forked end 76, so that the protrusions 74 are no longer aligned with the forked end 76. The forked end 76 is thus no longer blocked by the protrusions 74, and the adjustable heel 12 is free to be pivoted about the axis y. In this embodiment, the protrusions 74 are disc-shaped, so that any rotation of the latch member 72 will not prevent operation of the latch 70. In alternative embodiments, the protrusions are of some alternative shape. The latch member 72 has an operation end 73 for operation of the latch 70. The operation end 73 extends outwardly from a side of the shoe 10, so that the wearer can operate the latch 70 by pressing the operation end 73 inwardly, i.e. towards the shoe 10. In this embodiment, the operation end 73 is at an outer side of the shoe 10. That is, in a right shoe, the operation end extends from a right side of the shoe, and vice versa. This location of the operation end 73 provides easy access to the latch member 72, and so enables easy use of the latch 70. The latch 70 includes a resilient biasing mechanism 78 for returning the latch 70 to the closed position. In this embodiment, the resilient biasing mechanism is in the form of a compression spring 78. The spring 78 acts between the latch member 72 and the heel 11 to bias the latch 70 towards a closed position. Release of the latch member 72 returns the latch to the closed position shown in Figure 10a. In this embodiment, the protrusions 74 each define a ramp or chamfer 75 at an outer side of the protrusion 74 (i.e. the side proximal the operation end 73). The ramps 75 facilitate return of the latch 70 to the closed position. When the wearer wishes to convert the shoe from an elevated state to a lowered state, the wearer presses the operation end 73 of the latch member 72 towards the shoe 10. The first stage of pivoting of the adjustable heel 12 can then take place. Once the adjustable heel 12 has been moved from the deployed position, the latch 70 is disengaged, and so there is no need for the wearer to continue pressing the operation end 73. Conversion of the shoe 10 between elevated and lowered states can be carried out whilst the wearer is wearing the shoe 10, and can be carried out by the wearer. Upon pivoting of the adjustable heel 12 to the deployed position, the spring 78 acts to return the latch 70 to the closed state, and the adjustable heel 12 is secured in the deployed position. In alternative embodiments, some alternative suitable latch arrangement is used. In an alternative embodiment, the latch is disengaged by movement of the adjustable heel in the direction of a longitudinal axis of the adjustable heel, ora longitudinal axis of a portion of the adjustable heel. In an alternative embodiment, the latch is disengaged by movement of the adjustable heel along the longitudinal axis of the shoe in either direction. In this embodiment, the heel extension 40 is of titanium. At least the rear outer portion 79 of the sole 14 are principally of carbon fibre. The portion of the heel 11 that structurally supports the latch member 72, pivotable joint 18 etc. is formed from aluminium in this embodiment. The pivotable joint 18 and the sole adjustment arrangement 16 are of aluminium. The upper 13 may be manufactured of principally of suitable conventional material, for example genuine or synthetic leather material In alternative embodiments, other suitable materials are used. In an alternative embodiment, the heel extension, pivotable joint etc. are is of stainless steel, and / or the heel and the sole are of moulded plastics material. In certain embodiments, the structural components may be covered by coatings or layers of other material to provide an aesthetic similar to conventional shoes. Although the above embodiment relates to a shoe, the adjustable heel and adjustable sole are suitable for alternative types of footwear, such as a boot, and for alternative styles of shoe, such as sandals, Mary Jane, T-bar, ankle strap, court shoes, open toe shoes. Advantageously, the adjustable heel and adjustable sole can be used for shoes having heels of a range of heights without a change to the underlying mechanism.

Claims

1. Footwear convertible between an elevated state and a lowered state, the footwear comprising:an adjustable heel, wherein the adjustable heel is a ground engaging portion of the 5 shoe, wherein the adjustable heel is movable between a deployed position, where the footwear is in the elevated state and the heel is configured for contact with the ground, and a stowed position, where the footwear is in the lowered state and the adjustable heel is not configured for contact with the ground;a sole of adjustable angle; and10 a sole adjustment arrangement configured to adjust the angle of the sole;wherein the sole adjustment arrangement is configured to be operated by movement of the adjustable heel between the deployed position and the stowed position.

2. The footwear according to claim 1, wherein at least part of the movement of the 15 adjustable heel between the deployed position and the stowed position is pivotable movement.LO3. The footwear according to claim 2, further comprising a pivotable joint between the adjustable heel and the footwear, wherein the sole adjustment arrangement is configured ^^20 to be operated by movement of the pivotable joint upon pivoting of the adjustable heel between the deployed position and the stowed position.CM4. The footwear according to claim 3, wherein the sole adjustment arrangement comprises a body connected to the sole, and wherein the body is arranged in rotatable 25 connection with the pivotable joint, such that movement of the pivotable joint is configured to rotate the body such that the angle of the sole is adjusted; preferably wherein the sole adjustment arrangement further comprises at least one arm extending from the body, wherein the or each arm is connected to the sole.30 5. The footwear according to claim 4, wherein the body is rotatable between a firstposition, where the sole is adjusted to an angled state and a second position, where the sole is adjusted to a flatter state, preferably wherein when the adjustable heel is in the deployed position, the body is in the first position, and wherein when the adjustable heel is in the stowed position, the body is in the second position.

356. The footwear according to claim 4 or claim 5, wherein movement of the pivotable joint is configured to result in lesser rotational movement of the body.

7. The footwear according to claim 6, wherein the body is arranged in rotatable connection with the pivotable joint in a lost motion arrangement.

8. The footwear according to any one of claims 2 to 7, wherein, when the adjustable 5 heel is to be pivoted from the deployed position to the stowed position, the adjustable heel is configured for a first stage of pivoting away from a toe of the footwear, preferably wherein the adjustable heel is configured for a second stage of pivoting towards said toe.

9. The footwear according to claim 8, wherein, when the adjustable heel is to be 10 pivoted from the stowed position to the deployed position, the adjustable heel is configured for a third stage of pivoting away from a toe of the footwear, preferably wherein the adjustable heel is configured for a fourth stage of pivoting towards said toe.

10. The footwear according to any one of claims 2 to 9, wherein the adjustable heel is 15 pivotable between the deployed position and the stowed position about a transverse axis of the footwear, perpendicular to a longitudinal axis of the footwear.LDC\J 11. The footwear according to any one of claims 1 to 10, wherein the sole comprises atoe portion and a heel portion, wherein the toe portion and the heel portion are adjustable J 20 with respect to one another, and wherein the sole adjustment arrangement is configured to adjust the position of the toe portion and the heel portion with respect to one another CM along a longitudinal axis of the footwear so as to adjust the sole angle.CM12. The footwear according to claim 11, wherein the sole adjustment arrangement is 25 connected to the toe portion, such that the sole adjustment arrangement is configured to adjust the position of the toe portion.

13. The footwear according to claim 10 or claim 11, wherein the sole comprises a detent mechanism between the heel portion and the toe portion.3014. The footwear according to any one of claims 1 to 13, further comprising a latch configured to latch the adjustable heel in the deployed position.

15. The footwear according to claim 14, wherein the latch comprises a push-button35 release.

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