The present invention relates to footwear, more particularly to interchangeable heels for footwear so that a single pair of shoes can be used in flat form and in high heel form as per the requirement of the user. Preferably the present invention relates to interchangeable wedge and/or heels for footwear so that a single pair of shoes can be used in flat form and in high heel form as per the requirement of the user.

Background of the invention:

Most footwear comes with fixed heels. The user has no option to change the height and the type of heel that could be worn based on different situations. Typically users would use more flats or low height heels for comfort use and may prefer higher heels for formal or special occasions. Hence the user buys several footwear with different heel heights for different occasions.

There always remained a demand for the footwear having interchangeable heels so that same footwear may be used for different occasions and purposes. Several patents and applications are representative of various types of footwear with interchangeable components.

U.S. Pat. No. 5,953,836 teaches shoe having removable heels for permitting a user to wear a single pair of shoes which can be used in high heel form and in a flat form. The show includes a sole having opposite heel and toe ends. The lower surface of the sole has a hole therein located towards the heel end of the sole. The hole has a perimeter with a number of sides. Each of the sides of the perimeter of the hole has an aperture into the sole. A heel is also provided and has a block outwardly extended from its upper end. The block also has a number of sides with each of the sides of the block associated with a side of the perimeter of the hole. The block is removably inserted into the hole of the lower surface of the sole and each of the sides of the block has a detent which are inserted into the aperture of their associated side of the perimeter of the hole.

U.S. Pat. No. 8,112,908 B2 to Visser teaches a shoe with a removable and interchangeable heel that includes a first fixed heel disposed on a heel bottom portion of the shoe. The fixed heel includes a first fastener disposed therein. A second removable and interchangeable heel has a cooperating second fastener disposed therein that is engageable with the first fastener to secure the removable heel to the fixed heel, thereby increasing the effective height of the heel of the shoe.

U.S. Pat. No. 7,185,448 B2 to Schupbach teaches a shoe that includes a sole member, at least one heel member, a front securing member, and optionally a forward tread member. Each heel member includes a column portion having a predetermined height and a blade portion having a predetermined slope. Each blade portion's slope corresponds to the respective column portion's height for providing a proper amount of arch support for a user's foot. The sole member has an arch region made of a flexible material that defines a sleeve for selectively receiving each respective blade portion. Each blade portion includes a flange extending longitudinally therealong, and the sleeve defines a complementary groove. When the sleeve receives a respective blade portion, the blade portion provides shape and structural support for the sole member. Means for releasably attaching the respective column portion to the sole member are utilized, and the front securing member may secure the sole member to the user's foot.

U.S. Pat. No. 6,023,858 to Srourian teaches a two-piece shoe bottom system including a platform structure and a hollow interchangeable heel structure. The platform structure comprises a lower forepart portion, a raised rear heel portion, and a middle wedge portion connecting the forepart portion to the raised rear heel portion. The raised rear heel portion is elevated substantially above the forepart portion so that it will correspond to a particular height of the interchangeable heel structure. A reinforcing bolt member is molded to the underside of the raised heel portion of the platform structure. The hollow interchangeable heel structure is detachably attached to the reinforcing bolt member.

U.S. Pat. No. 5,133,138 to Durcho teaches a replaceable high heel for use with a shoe having an upper and a sole and with a block downwardly extending from the lower portion of the sole adjacent to the heel and with a magnetic plate facing downwardly from the block, an improved replaceable heel having an upper surface with an upwardly facing recess therein and a magnetically responsive plate face upwardly on the lower surface of the recess.

U.S. Pat. No. 4,219,946 to Baum teaches a shoe with an interchangeable heel that comprises two parts, a main sole part reinforced in its rear end section by a rigid plate and a separate heel part. The heel part is fitted to the reinforced section of the sole part by a ferrule, fixed to one part, having a projecting portion of non-circular cross-section which prevent rotation of the heel, and a removable locking element is provided to lock the heel part in place.

U.S. Pat. No. 2,478,264 to George et al teaches an interchangeable heel and heel tap arrangement with an attaching plate on the bottom of a shoe for attachment and removal of a heel that utilizes a resilient latch.

United States Patent Application No. 2011/0119954 to Ortiz teaches a safety replaceable heel mechanism that is used to adjust the height of women's shoes. The mechanism comprises a shoe sole, a removable heel comprising a heel connector and an interchangeable heel, and a locking key to securely connect the removable heel to the shoe sole. The heel is detached and the shoe can be worn without the heel, providing a pair of shoes suitable for different occasions. The invention is provides a stable structure avoiding unwanted movement of the removable heel for adjusting the comfort of a particular pair of shoes during the course of a day.

US 20140137436 Al to Sandra teaches footwear having interchangeable heels, having a top component having a back section, a middle, a front and an upper section for encompassing a foot, the said top component having an underside shape and contour, and having at least two separate connect mechanisms for connection to a bottom component; a bottom component having a having back, a middle, and a front section, the said bottom component having a topside shape and contour sufficiently coinciding with the top component underside shape and contour so as to nest with one another, and having at least two separate connect mechanisms corresponding to at least two separate mechanisms of the top component for connection to it.

While these devices fulfill their respective, particular objectives and requirements particularly interchangeable heel footwear, most of the said known footwear differ in the way the heels are attached to the footwear. Most of them have some sort of a button release mechanism followed by a pull or push operation, which makes the heel interchanging process cumbersome.

Accordingly, it can be seen that need exists for improved interchangeable heels for a pair of complementary footwear without any complicated interchanging mechanism. In view of the foregoing background, the present invention obviates the drawbacks of the prior known and available footwear with interchangeable heels and provides interchangeable heels for a pair of complementary footwear without any complicated interchanging mechanism by providing a pivoted locking fulcrum clip which remains in a locked position when the sole of the footwear is on the ground surface. Thus, notwithstanding the prior art, the present invention is neither taught nor rendered obvious thereby.

Summary of the invention:

In order to achieve the afore-said objective, the present invention according to one of the embodiment provides a complementary footwear with interchangeable heels comprising an insole 1; a main sole 2; a detachable heel 3, wherein the inner side of the main sole 2 is provided with a pivoted locking fulcrum clip 4 and locking groove 6 to lock the heel 3 onto the sole 2; the inner side of the heel 3 is provided with locking clip 5 and locking snaps 7; said fulcrum clip 4, locks into the locking clip 5 provided on the inner side of the heel 3 and the said locking groove 6 snap locks with the locking snaps 7 to hold the said heel 3. The fulcrum clip 4 is fixed onto the sole 2 by a pivot pin 8.

According to another the embodiment, the invention provides a complementary footwear with interchangeable heels comprising an insole 1; a main sole 2; a detachable heel 3, wherein the inner side of the main sole 2 is provided with a pivoted locking fulcrum clip 4 and locking groove 6 to lock the heel 3 onto the sole 2 and at least one spring 9 for holding the heel against the fulcrum clip 4; for securing the said spring 9, a spring holding plate 11 is fixed onto the sole 2 by at least one spring fixing boss 10; the inner side of the heel 3 is provided with locking clip 5 and locking snaps 7; said fulcrum clip 4, locks into the locking clip 5 provided on the inner side of the heel 3 and the said locking groove 6 snap locks with the locking snaps 7 to hold the said heel 3. The fulcrum clip 4 is fixed onto the sole 2 by a pivot pin 8.

According to another the embodiment, the invention provides the fulcrum clip is optionally sliding type.

According to another the embodiment, the invention provides , spring 9 is of any type such as compression spring or torsion spring and of any material selected from the group of plastic, rubber etc. any material selected from the group of plastic, wood, leather, composites, metal, rubber etc.

According to another the embodiment, the invention provides the heels of any shape and size such as block heels, narrow heels and wedges across various heel heights.

According to another the embodiment, the invention provides a method of mounting the heel 3 onto the sole 2 comprising:

- inverting the footwear i.e. the sole 2 is facing the ground such that the fulcrum clip 4 falls due to gravity;

inserting the heel 3 by sliding towards the proximal end of the shoe; wherein the heel 3 is secured inside the sole by locking snap 7 on the heel 3 and locking groove 6 on the sole 2;

inverting the footwear i.e. the heel 3 is facing the ground and push the heel 3 further towards toe side gently; wherein as the heel 3 faces the ground the pivoted locking fulcrum clip 4 falls due to gravity;

- on removing the mechanical pressure from the heel 3, spring 9 pushes back the heel 3 till the locking clip 5 touches the fulcrum clip 4.

According to another the embodiment, the invention provides method of mounting the heel 3 onto the sole 2; wherein optionally the sole 2 is in normal position i.e. the sole 1 part is facing the sky such that the fulcrum clip 4 falls due to gravity, comprising the steps of

- sliding the heel 3 towards the proximal end of the shoe such that it lifts the fulcrum clip 4;

- securing the heel 3 inside the sole 2 with locking snap 7 on the heel 3 and locking groove 6 one the sole 2;

- pushing the heel further towards toe side gently so that the pivoted locking fulcrum clip 4 will fall due to gravity.

According to another the embodiment, the invention provides method of dismantling the heel from the shoe wherein the footwear is inverted and the heel is pushed towards toe, slided and pulled out. Brief Description of the drawings:

The novel features believed to be characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, together with further objects and advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings, wherein like numerals are used to represent like elements.

It is to be noted, however, that the appended drawings illustrate only typical embodiments of the present subject matter, and are therefore, not to be considered for limiting of its scope, for the subject matter may admit to other equally effective embodiments.

Figure 1: Isometric view of sole

Figure 2: Front view of sole

Figure 3: Sectional front view of sole

Figure 4: Top view of sole

Figure 5: Bottom view of sole (without heel)

Figure 6: Sectional view of sole (without heel)

Figure 7a-l to 7a-3: Isometric view of sole without heel and without insole

Figure 7b-l to 7b-2: Isometric view of heel

Figure 8-la to 8-ld: Assembly process of heal onto the sole according to one embodiment of the invention

Figure 8-2a to 8-2d: Assembly process of heal onto the sole according to another embodiment of the invention

Figure 9a to 9c: Different size and types of heels fitted onto the sole

Figure 10: Isometric view of wedge

Figure 11: Isometric view of Sole for wedges

Figure 12: Locking mechanism in wedge

Figure 13: Detailed view (A) of the locking snap of wedge

The reference numerals in the figures to be read as follows:

1: Insole

2: Sole

3: Heel

4: Fulcrum Clip (inside sole)

5: Locking Clip (inside heel) 7: Locking Snaps (inside heel)

8: Pivot pin (inside sole)

9: Spring (inside sole)

10: Spring holding plate fixing boss (inside sole)

11. Spring holding plate (inside sole)

Detailed description of the invention:

The following presents a detailed description of various embodiments of the present invention with reference to the accompanying drawings.

The embodiments of the present invention are described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments which are only provided to explain more clearly the present subject matter to a person skilled in the art of the present disclosure. In the accompanying drawings, like reference numerals are used to indicate like components.

The specification may refer to "an", "one", "different" or "some" embodiment(s) in several locations. This does not necessarily imply that each such reference is to the same embodiment(s), or that the feature only applies to a single embodiment. Single features of different embodiments may also be combined to provide other embodiments.

As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless expressly stated otherwise. It will be further understood that the terms "includes", "comprises", "including" and/or "comprising" when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. It will be understood that when an element is referred to as being "attached" or "connected" or "coupled" or "mounted" to another element, it can be directly attached or connected or coupled to the other element or intervening elements may be present. As used herein, the term "and/or" includes any and all combinations and arrangements of one or more of the associated listed items.

The figures depict a simplified structure only showing some elements and functional entities, all being logical units whose implementation may differ from what is shown. The present invention is a unique system of interchangeable heels for a pair of complementary footwear. The present system of interchangeable heels allows user to easily detach and attach heels to the complementary pair of footwear based on personal choice and situation. The system is also unique in a way that it allows user to change not only the heel heights but also type of heels from block to narrow heels (stiletto) and even wedge.

There are some interchangeable heel footwear available in the global market. All of them differ in the way the heels are attached to the footwear. Most of them have some sort of a button release mechanism followed by a pull or push operation. Also they do not offer the flexibility to go from block and narrow heels to wedge heels in the same shoe.

According to one of the embodiment of the present invention is simple and involves a pivoted locking fulcrum clip which remains in a locked position when the sole of the footwear is on the ground surface. To replace the heel, the user has to invert the footwear by at least by 90 degrees, preferably more than 90 degrees, more preferably by 180 degrees. When the footwear is inverted, the fulcrum clip gets released from the locking clip and the heel can be pulled out with ease.

According to another embodiment of the present invention, in order to secure the wedge heel, there is an additional locking feature developed that allows wedge to be held positively.

According to another embodiment of the present invention, the main sole 2 comprises an insole 1 and heel 3. Said heel 3 is detachable. The inner side of the sole 2 comprises a fulcrum clip 4 to lock into the locking clip 5 provided on the inner side of the heel. Said fulcrum clip 4 is fixed onto the sole by a pivot pin 8. Further, the locking groove 6 are provided on the inside sole. Said locking groove 6 snap locks with the locking snaps 7 provided inside the heel 3 to hold the said heel 3. Further, the sole may be provided with spring 9. Said spring 9, is conventional spring available, for e.g. torsion spring. Said spring is provided for holding the heel against fulcrum clip 4 and stopping accidental dislodging of the heel. A spring holding plate 11 is provided on the sole for retaining the spring at its place. A spring holding plate fixing boss 10, are provided in the sole for fixing spring holding plate. inverting the footwear i.e. the sole 1 part is facing the ground (figures 8-1 a to d). The heel 3 is located and inserted as shown in figure 8-la. When the footwear is inverted, fulcrum clip 4 will fall due to gravity as shown in figure 8-la. 4. The heel 3 is slided towards the proximal end of the shoe as shown in figure 8b. The heel 3 is locked inside the sole due to locking snap 7 and locking groove 6 as shown in the figure 8-lc. Now on inverting the footwear i.e. heel 3 is facing the ground the pivoted locking fulcrum clip 4 will lock to the locking clip 5 as shown in figure 8-ld. Once the heel 3 gets locked onto the sole, it will not be possible for said heel to come out until the shoe is again inverted and heel is slided towards the distal end of the shoe.

According to another embodiment of the present invention the assembly procedure requires inverting the footwear i.e. the sole 1 part is facing the ground. When the footwear is inverted, fulcrum clip 4 will fall due to gravity as shown in figure 8-2 a. The heel 3 is located and inserted as shown in figure 8-2 a. The heel 3 is slided towards the proximal end of the shoe as shown in figure 8-2 b. The heel 3 is secured inside the sole due to locking snap 7 on the heel 3 and locking groove 6 one the sole 2 as shown in the figure 8-2 c. Next step requires to invert the footwear again i.e. now the heel 3 is facing the ground and push the heel further towards toe side gently. Now as the footwear is inverted i.e. heel 3 facing the ground the pivoted locking fulcrum clip 4 will fall due to gravity as shown in figure 8-2 d-1. Now as soon the hand is removed from the heel 3, spring 9 shall push back the heel 3 till the locking clip 5 touches the fulcrum clip 4 as shown in fig. 8-2d-2. Once the heel 3 gets locked onto the sole, it will not be possible for said heel to come out until the shoe is again inverted and heel is slided towards the distal end of the shoe.

According to another embodiment of the present invention the assembly procedure involves holding the footwear in normal position i.e. the sole 1 part is facing the sky. Fulcrum clip 4 will fall due to gravity as shown in figure 8-2a-l.The heel 3 is located and inserted as shown in figure 8-2a-l. The heel 3 is slided towards the proximal end of the shoe as shown in figure 8-2b-l. While the heel 3 is being slided, it lifts the fulcrum clip 4 as shown in figure 8- 2b-l.The heel 3 is secured inside the sole due to locking snap 7 on the heel 3 and locking groove 6 one the sole 2 as shown in the figure 8-2c. Next step requires to push the heel further towards toe side gently (heel is facing the ground).

As heel 3 is facing the ground, the pivoted locking fulcrum clip 4 will fall due to gravity as shown in figure 8-2d-l. Now as soon the hand is removed from the heel 3, spring 9 shall push back the heel 3 till the locking clip 5 touches the fulcrum clip 4 as shown in fig. 8-2d-2. Once the heel 3 gets locked onto the sole 1 part, it will not be possible for said heel to come out until the shoe is inverted and heel is slided towards the distal end of the shoe.

According to another embodiment of the invention, once the heel 3 gets locked onto the sole 1 part, it will not be possible for said heel to come out due to combined effect of the spring force and the angle of contact between the locking clip 5 and the fulcrum clip 4 and pivot pin 8 position as shown in fig. 8-2d-2.

According to another embodiment of the invention for assembly of wedge, the aforesaid procedure is followed as for heel assembly, however, before assembly it has to be made sure that locking snap is aligned with locking groove, see figures 10 to 13.

According to another embodiment of the invention for dismantling the heel from the shoe, the footwear (sole part is facing the ground) is inverted and the heel is pushed towards toe side gently and then slided (away from toe side) and pulled out.

According to another embodiment of the present invention the heels of any shape and size may be used. Such as block heels, narrow heels and wedges across various heel heights small (@ 30 mm), medium (@55 mm) and high (@80 mm)

According to another embodiment of the present invention the shoe may be of any shape and size. Such sandals, open/semi-closed and closed shoe, boots in sizes 36, 37, 38, 39, 40, 41 (as per various country standards)

According to another embodiment of the present invention the soles and heels may be of any material. Such as plastic, wood, leather, composites, metal, rubber etc.

According to another embodiment of the present invention the springs may be of any type like compression spring or any material such as plastic, rubber etc. with some changes in construction.

According to another embodiment of the present invention the fulcrum clip may be sliding type with some changes in the construction.

Advantage of the invention: needs.