A One-Piece Shoe With a Stiffer Heel How Two Plastic Hardnesses Let You Step In Without Using Your Hands

This application covers a slip-on shoe whose upper, sole and heel cup are moulded as one unit, with the heel cup made from a plastic of a different hardness to the rest of the shoe. It was filed by Skechers U.S.A., Inc. II, names Abel Casas and Chase Greenberg as inventors, and is a divisional of Australian application 2024441060. A sister divisional filed the same day, AU 2026202271, shares this description but claims a manufacturing method instead of the finished shoe, as explained below.

The Problem

The specification is unusually short on background. It has no discussion of earlier shoes, no complaint about laces or heel crushing, and its “Field of the Disclosure” paragraph is a boilerplate disclaimer about prior art followed by the statement that the innovations “generally address footwear”. The only problem it identifies is implicit in the name: a shoe that can be put on “hands-free”, with the foot pushing the heel out of the way rather than the wearer bending down to pull the heel open.

The description does explain the mechanics it is after. A shoe has to open wide enough for the foot to pass through and then grip the heel once the foot is inside. A heel counter that is rigid enough to hold the heel will resist the foot going in, and one that is soft enough to give way will not hold the heel afterwards. The specification’s answer is a heel cup that is stiffer than the surrounding shoe but is shaped to flex under the load of the foot and spring back.

What This Invention Does

Claim 1 is an article of footwear comprising a uniformly moulded upper, sole and heel cup. The heel cup is made of a first plastic, the sole or upper is made of a second plastic, and the first plastic has a different hardness from the second. That is the whole of the independent claim. It does not say which is harder, and it does not mention a heel that deforms.

The narrower claims add the detail. Claim 2 specifies that the heel cup plastic is the harder one. Claim 3 describes the heel cup as moulded with an upper portion, a midportion and a lower portion, where the upper portion is narrower from side to side than the midportion, and the midportion and lower portion form a concave seat for the heel. The upper portion has a first configuration and distorts into a second configuration under the load of the wearer’s foot during donning. Claim 4 gives the heel cup an S wave shape in vertical cross section, and claim 5 says the thickness varies between the three portions. Claim 6 adds that the upper is moulded together with the sole and heel cup.

The description fills in numbers. It gives hardness examples measured on a Shore C durometer: a heel at or near 60 with an upper and sole at or near 40, or a heel near 52 with an upper and sole near 45, or a single hardness throughout at figures such as 50, 55 or 38 to 40. In the exemplary S wave, the upper arc is about 2 centimetres wide and about 3 millimetres in amplitude, while the lower arc is about 4.5 centimetres wide and about 9 millimetres in amplitude. Heel cup thickness runs from 0.4 to 4 millimetres, with a central region of the midportion at roughly a quarter to a sixth of the thickest edge, around 0.5 to 1 millimetre, and edges of 2 to 3 millimetres. In one embodiment a 7.5 centimetre shoe opening widens by up to 4 centimetres, about 50 per cent, when the heel cup is compressed. The specification gives no test data on how much force this takes or how many cycles the heel cup survives.

Key Features

• Moulded as one piece. The upper, sole and heel cup are uniformly moulded, so the shoe is made from plastic in moulds rather than cut and stitched from separate fabric parts. The description allows other upper materials such as mesh, nylon or suede with only the sole and heel cup moulded.
• Different hardness in the heel. Claim 1 requires only that the heel cup plastic differ in hardness from the sole or upper. Claim 2 makes the heel cup the harder of the two.
• A heel cup that gives way and springs back. Under claim 3 the upper portion of the heel cup distorts under the load of the foot, lowering relative to its resting shape, and returns once the foot is in.
• An S wave cross section. Claim 4 gives the rearmost part of the heel cup a shape like an S in vertical section, with a smaller upper arc and a larger lower arc in the worked dimensions.
• Variable thickness. Claim 5 has the three portions at different thicknesses, and the description puts a thin zone in the middle of the heel cup so that it bends there. Claim 5 as printed contains a drafting slip, since it compares the second thickness against “the first thickness and the second thickness”.
• Choice of plastics. The description lists ethylene vinyl acetate (EVA), compression moulded EVA, thermoplastic polyester elastomer (TPEE) and thermoplastic polyurethane (TPU), with TPEE or TPU suggested for the heel cup.

Who Is Behind It

The applicant is Skechers U.S.A., Inc. II, the operating entity of Skechers, a footwear company founded in 1992 and headquartered in Manhattan Beach, California, by Robert Greenberg. Skechers was taken private by 3G Capital, a deal announced on 5 May 2025 and, according to FashionUnited, completed in September 2025 at a price of about 9 billion dollars. The company sells a Hands Free Slip-ins range, which is the commercial context for this filing, although the specification does not name any product. Wikipedia also records that Kizik, a rival hands-free shoe maker, sued Skechers in 2025 over its Slip-ins, which shows how contested this area has become. The specification does not say how the inventor Chase Greenberg relates to the company’s founder, and nothing here should be read as saying so.

On priority, the description states that it is a non-provisional claiming priority under 35 U.S.C. 119 to US provisional application 63/636,403, filed 19 April 2024. It adds that it is also a divisional of Australian application 2024441060, the national phase of PCT/US2024/052684 filed on 23 October 2024. The priority country is therefore the United States.

Why It Matters

Slip-on shoes sell on convenience, and the hard part is the heel. A heel counter that is stiff holds the foot well but makes entry awkward, and a soft one lets the heel collapse. Putting two plastics of different hardness into a single moulded shoe is a way to build the stiff and the springy parts into the same product without a separate heel insert being stitched in later.

The claim is also broad on its face. Claim 1 asks for a moulded upper, sole and heel cup and a hardness difference, and the movement of the heel cup appears only in dependent claim 3. A reader should treat claim 1 as the reach of the application and claims 3 to 5 as the specific engineering. Moulded construction also suits a high volume plastic shoe, because the whole upper can come out of a mould instead of being assembled.

Related Concepts

• Injection moulding – the process used to form the moulded upper, sole and heel cup.
• Shore durometer – the hardness scale behind the Shore C figures for the heel and body of the shoe.
• Ethylene-vinyl acetate – the foam plastic widely used in midsoles and named in the specification.
• Thermoplastic polyurethane – one of the harder plastics suggested for the heel cup.
• Thermoplastic elastomer – the rubbery thermoplastic family that includes the polyester elastomer named for heel parts.

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AU 2026202270 was published in the Australian Official Journal of Patents on 9 April 2026 and is open for public inspection. Patent applications represent inventions that are sought to be protected and do not necessarily reflect commercially available products.