Footwear with extendable heel

Technical field

The present invention relates to footwear with a heel. The invention has application in the sector of fashion footwear, but also of orthopaedic footwear.

Prior art

The heel of a shoe is a very important element. A low heel allows an emphasis to be placed on wearing comfort, a high one can make a person look slimmer and taller. However, wearing shoes with a high heel can tire a person who, especially after prolonged use, may feel the need to change into more comfortable shoes.

Shoes with an interchangeable heel of varying length are known. Therefore, the wearer can adopt a heel of the size they most prefer.

Shoes provided with a heel that is movable by means of a complex kinematic mechanism are also known. One drawback of this solution is tied to the weight and complexity of the kinematic mechanism, as well as the difficulties of miniaturising such a solution to adapt it to the positioning in the shoe. There are also known solutions whereby the heel is movable by means of a system in which the wearer must exert a force to manually overcome the resistance posed by the movement system. Such a solution is not without drawbacks. In fact, the wearer, when manoeuvring near the shoe to apply the necessary effort to adjust the heel as desired risks getting dirty.

Disclosure of the invention

In this context, the technical task at the basis of the present invention is to propose footwear that enables the heel height to be adapted by means of an optimised system.

The stated technical task and specified objects are substantially achieved by footwear comprising the technical features disclosed in one or more of the accompanying claims. Brief description of the drawings

Additional features and advantages of the present invention will emerge more clearly from the approximate, and thus non-limiting, description of a preferred but not exclusive embodiment of footwear as illustrated in the accompanying figures, in which:

- figures 1 and 3 show perspective views of footwear according to the present invention in which some parts have been removed to better highlight other technical-functional ones;

- figure 2 shows a front view of the solution in figure 1 ;

- figure 4 shows a detail of figure 3;

- figures 5 and 6 show detail components of the footwear in figure 1 ;

- figure 7 shows the component in figure 6 in a different configuration.

Detailed description of preferred embodiments of the invention

In the accompanying figures, the reference number 1 indicates an item of footwear. The footwear 1 comprises an extendable heel 2. The heel 2 is telescopically extendable.

Conveniently, the extendable heel 2 comprises a plurality of telescopically slidable sections. Conveniently, they have progressively decreasing overall transverse dimensions (typically a diameter). In a configuration of minimum lengthening, the sections are conveniently housed in a fixed tubular portion. In one example embodiment there could be from one to seven slidable sections, preferably from 3 to 5. For example, in the embodiment illustrated in the accompanying figures there are four slidable sections. Conveniently, in a configuration of maximum lengthening, the heel 2 is between 125 and 140 millimetres long. Conveniently, in the configuration of minimum lengthening, the heel 2 has a length comprised between 35 and 50 millimetres.

The heel 2 can comprise at least a first and a second hollow section 21 , 22 telescopically slidable relative to each other. The slidable sections, in particular the first and the second section 21 , 22, are concentric. Moreover, they are coaxial. The first and second sections 21 , 22 are in reciprocal fluid communication by means of a cap 210 defining at least one calibrated orifice. The calibrated orifice could have an adjustable size, for example adjustable by means of a grub screw. Optionally, the cap 210 could also comprise one or more connection holes in addition to the calibrated orifice. Advantageously, a plurality of sections are fluid- dynamically connected two by two by means of a corresponding cap defining a calibrated orifice. In the example embodiment, the orifice could be absent on the last slidable section (the one with the smallest transverse dimensions).

The calibrated orifice enables the cavities of the sections to be placed in fluid communication, thus allowing a proportionate lengthening of the individual sections.

Starting from a configuration of minimum lengthening, the slidable sections initially all move together. Each section thus comes out of the immediately larger section. After a section reaches the end of its stroke the lengthening continues with the other sections. During a lengthening stroke the widest slidable section will typically be the first to reach the end of its stroke. Conveniently, the slidable sections have progressively decreasing braking when passing from the slidable section with the largest transverse dimensions to the one with the smallest transverse dimensions. This serves to facilitate the passage of fluid from the slidable section with the largest transverse dimensions to those of larger dimensions. The braking of the sections is regulated for example on the basis of friction coefficients of the seals (which may for example vary as a function of the diameter of the section and/or manufacturing tolerances and cause resistance to forward movement).

The footwear 1 comprises a means 3 for lengthening/shortening the extendable heel 2. The lengthening/shortening means 3 comprises: -a first electric motor 31 ;

-a fluid-dynamic actuator 32 for moving the heel 2 and operatively interposed between the first electric motor 31 and the extendable heel 2. The actuator 32 comprises at least a first piston 320 moving a substantially incompressible fluid, for example distilled water or another liquid. Conveniently, a filter for the working fluid is present. Conveniently, there is thus a hydraulic movement with the filtration of distilled water. This is to the advantage of the environmental impact, as the latter is not a pollutant. The piston 320 is mobile (it typically translates) inside a first jacket 325. The fluid-dynamic actuator 32, in at least one configuration of the footwear, is in fluid communication with the heel 2. Conveniently, the footwear 1 comprises a valve 7 that allows/prevents the lengthening/shortening of the heel 2. Conveniently, the valve 7 is a solenoid valve. In an open configuration, the valve 7 enables fluid communication between the fluid-dynamic actuator 32 and the heel 2. In the open configuration the valve 7 thus allows the incompressible fluid to be introduced into the heel 2 (with a consequent lengthening of the heel 2), or the incompressible fluid to be evacuated from the heel 2 (with a consequent shortening of the heel 2). The valve 7 can also take on a closed configuration in which it prevents fluid communication between the heel 2 and the fluid-dynamic actuator 32. Consequently, in the closed configuration the fluid present in the heel 2 cannot flow out, preventing the heel 2 from being shortened under the weight of the wearer.

Conveniently, the footwear 1 comprises a conduit 34 that connects the fluid-dynamic actuator 32 and an expandable chamber 20 inside the heel. The conduit 34 can comprise a tube, preferably a flexible one. The conduit 34 could also pass inside a hinge connecting the intermediate portion 42 and the rear portion 41 . The chamber 20 involves a plurality of sections of the heel 2. At least one portion of the conduit 34 is conveniently flexible.

Conveniently, the footwear 1 comprises a control unit that coordinates the configuration taken on by said valve 7 and the action of the lengthening/shortening means 3.

In a first operating mode the valve 7 is open and the lengthening/shortening means 3 moves. In a second operating mode the valve 7 is closed and the lengthening/shortening means 3 is stationary.

Conveniently, the footwear 1 comprises a system for detecting the rotation of the first motor 31. Advantageously, the footwear 1 comprises an encoder associated with the first motor 31. In this manner, the position of the first piston 320 relative to the first jacket 325 is known.

The footwear 1 comprises a rear portion 41 comprising the heel 2. It is intended to accommodate the heel of a wearer of the footwear 1 .

The footwear 1 comprises a front portion 43. It typically comprises the toe of the footwear 1 . The front portion 43 is hinged to the intermediate portion 42.

The footwear 1 comprises an intermediate portion 42 interposed between the rear portion 41 and the front portion 43. The front portion 43 is rotatably constrained to the intermediate portion 42. The fluid-dynamic actuator 32 and/or the first motor 31 are integrated into the intermediate portion 42. The fluid-dynamic actuator 32 is part of (or defines or contributes to defining) a weight-bearing frame for supporting a wearer’s foot.

Conveniently, the first motor 31 , by pushing the first piston 320, causes its extraction from the first jacket 325. On the other hand it (the first motor 31 ), by drawing the first piston 320 towards it, brings about the insertion thereof into the jacket 325.

The actuator 32 comprises a second piston 330 mobile along a second jacket 335. Conveniently, the first and second jackets 325, 335 are reciprocally joined or constrained. Advantageously, the first and second jackets 325, 335 are adjacent and extend parallel to a same main direction. The first and/or second jacket 325, 335 define a reservoir for the fluid. The first and second pistons 320, 330 can translate along a same direction. Conveniently, the first and second pistons 320, 330 are integrally mobile. The first and second pistons 320, 330 operate in parallel. Conveniently, the first and second pistons 320, 330 have an identical geometry. Conveniently, they have a diameter comprised between 13 and 18 millimetres, preferably 16 millimetres. Advantageously the stroke of the first piston 320 is comprised between 30 and 40 millimetres. Conveniently, when the valve 7 is open, both the first and the second piston 320, 330 (or in any case the first and second jackets 325, 335) are in fluid communication with the inside of the heel 2. Conveniently, the conduit 34 enables fluid communication between the first and/or second piston 320, 330 and the expandable chamber 20 inside the heel 2. Conveniently, a branched connection is present which connects the first and second jackets 325, 335 with the conduit 34. The branched connection allows a three-way connection to be defined, a direct one towards the heel 2, a direct one towards the first piston 320 and a direct one towards the second piston 330. Conveniently, the valve 7 is situated along the conduit 34 or at one end thereof. The valve 7 is operatively interposed between the fluiddynamic actuator 32 and the chamber 20.

The first and second pistons 320, 330 are both driven by the first motor 31 . Conveniently, the first motor 31 comprises a first shaft; a movement, typically a translation, of the first piston 320 and/or the second piston 330 corresponds to a rotation of the first shaft. Conveniently, a first reduction gear 81 can be present between the first motor 31 and the first and/or second piston 320, 330. The first reduction gear 81 is situated between the first and second jackets 325, 335.

Conveniently, the first motor 31 or the first reduction gear 81 or a kinematic mechanism situated downstream of the first motor 31 and driven by the first motor 31 comprises a threaded shaft that meshes with an internal thread integral with the first piston 320. In this manner, a movement, typically a translation, of the first piston 320 corresponds to a rotation of the first motor 31. Depending on the direction of rotation of the threaded shaft, there is a corresponding movement of the first piston 320 in one direction or the other. The threaded shaft-internal thread conveniently defines a coupling by means of a worm gear. As regards the speed of extension, assuming the use of an M6 worm gear with a 1 - millimetre pitch and considering a maximum speed of the first reduction gear of 330 rpm, there will be a maximum speed of the first piston of 5.5 millimetres per second.

The encoder precisely determines the number of revolutions of the first motor 31 or first reduction gear 81 and, based on the pitch of the thread of the threaded shaft that meshes with an internal thread, information is obtained on the stroke of the first and/or second piston 320, 330.

In a preferred embodiment, the fluid-dynamic actuator 32 comprises a first and a second syringe 321 , 322 arranged side by side. The first and second pistons 320, 330 are part of the first and second syringes 321 , 322. At least a part of the first electric motor 31 is operatively interposed between the two syringes 321 , 322. The first and second syringes 321 , 322 are actuated by the first motor 31. The conduit 34 allows fluid communication between the chamber 20 and the first and second syringes 321 , 322.

The footwear 1 comprises a means 5 for adjusting an inclination of the heel 2 relative to the intermediate portion 42. Conveniently, this enables the footwear 1 to be made more comfortable. In fact, the shape of the footwear 1 adapts to the lengthening/shortening of the heel 2. Conveniently, the control unit of the footwear 1 actuates the adjusting means 5 as a function of an input coming from the lengthening means 3. Advantageously, the means 5 for adjusting an inclination of the heel 2 comprises:

- a mobile actuator 51 applied to the intermediate portion 42; advantageously, the mobile actuator 51 is extendable; the actuator 51 is usually a linear actuator; the mobile actuator 51 is typically a sliding actuator; conveniently, the mobile actuator 51 translates along a guide;

- a lever mechanism 52 rotatably constrained both to the mobile actuator 51 and to the rear portion 41 .

The lever mechanism 52 is rotatably constrained to the intermediate portion 42 by means of a hinge 520, which fixed relative to a base 521 from which the heel 2 extends.

Conveniently, the lever mechanism 52 is directly rotatably constrained both to the actuator 51 and to the intermediate portion 42. In particular, the lever mechanism 52 comprises/coincides with a rod hinged at one end to the actuator 51 and at the other end to the actuator 51 .

The means 5 for adjusting an inclination of the heel 2 comprises a second electric motor 53 which drives said mobile actuator 51. Conveniently, the second motor 53, by moving the actuator 51 , brings the actuator 51 closer to or farther away from itself. Conveniently, the second motor 53, on moving the actuator 51 , moves closer to or away from the hinge 520. This corresponds to a variation in the inclination of the intermediate portion 42. A rotation of the lever mechanism 52 about the hinge 520 corresponds to a movement of the second motor 53.

Conveniently, a second reduction gear 82 is present between said second motor 53 and said mobile actuator 51. The second reduction gear 82 enables a reduction in the number of rotations in the unit of time output by the second motor 53. The second reduction gear 82 is conveniently interposed between the first and second jackets 325, 335. This enables the overall dimensions to be optimised. Conveniently, a rotating shaft of the second motor 53 or the second reduction gear 82 or a kinematic mechanism interposed between the second motor 53 and said actuator 51 meshes with an internal thread integral with the mobile actuator 51. A movement of the mobile actuator 51 corresponds to a rotation of said shaft. A different direction of linear movement of the mobile actuator 51 corresponds to a different direction of rotation of the shaft. For example, two opposite directions of the linear movement of the actuator 51 correspond to a clockwise and anticlockwise rotation of the shaft.

Conveniently, the second motor 53 and/or said actuator 51 are provided in said intermediate portion 42.

The first and/or the second motor 31 , 53 is/are DC motors. Conveniently, the footwear 1 comprises a battery as a power source. The battery is advantageously of the rechargeable type. It powers the first and/or the second motor 31 , 53.

Conveniently, the first and second motors 31 , 53 are provided on opposite faces of the fluid-dynamic actuator 32.

The control unit reciprocally coordinates the configuration taken on by said valve 7 and the action of the adjusting means 5.

Conveniently, the control unit reciprocally coordinates the action of the lengthening/shortening means and the action of the adjusting means 5.

In this regard, the control unit (or in any case the footwear 1 ) advantageously comprises a means for synchronising the means 5 for adjusting the inclination of the heel 2 and the means 3 for lengthening/shortening the heel 2.

In the configuration of maximum lengthening of the heel 2, the angle between the axis of the heel 2 and the direction of extension of the intermediate portion 42 is comprised between 25 and 35°. In configurations in which the heel 2 is less lengthened, the angle is greater. Conveniently, the footwear 1 comprises a wireless means for interfacing with an external device, for example an antenna. The external device can be, for example, a telephone, a tablet, or another electronic device (preferably provided with a dedicated software application). The wireless means can for example operate using radiofrequency. The wearer can thus conveniently provide input to the lengthening means 3 by means of the external device. In this regard, the wireless means is operatively connected with the control unit. Adjustment of the heel 2 can also take place while the footwear 1 is worn. In particular, shortening of the heel 2 takes place by activating the lengthening/shortening means 3. Advantageously, in order to lengthen the heel 2 while wearing the footwear 1 , the wearer will shift the weight onto the toes and activate the lengthening/shortening means 3.

The invention achieves important advantages. First of all, it enables the shoe components and production costs to be optimised. Moreover, it enables an easy, fast adjustment of the heel without having to dirty one’s hands and without physical effort. In addition, the footwear 1 could also be used for medical purposes, for example in cases in which a wearer may have one leg with a slightly different length from the other. The footwear can be women’s footwear or men’s footwear.

The invention thus conceived is susceptible of numerous modifications and variants, all falling within the scope of the inventive concept that characterises it. Furthermore, all the details may be replaced with other technically equivalent elements. All the materials used, as well as the dimensions, may in practice be any whatsoever according to needs.