US4245406A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Athletic shoe
Assignee: Brookfield Athletic Shoe Co Inc
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Filing: 1979-05-03
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Granted: 1981-01-20
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Expires: 1999-05-03
Abstract
Abstract A shoe and its method of manufacture in which an upper and preformed rubber outsole are joined by a foamed polyurethane, injection-molded midsole. The rubber outsole and polyurethane foam midsole combine to provide a lightweight and flexible shoe compressively conformable to the flexing foot and having strong traction and long wear.
Inventors
- 👤 David L. Landay
- 👤 Alvan H. Wolf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 11:01
CPC Classifications
B; B29; B29D; B29D35/00; B29D35/10; Y; Y10; Y10T; Y10T428/00; Y10T428/24; Y10T428/24149
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
90 words
A flexible athletic shoe comprising: an upper including a lower edge adapted for bonding to polyurethane, a flexible rubber outsole conformable to the flexing foot and having an outer surface providing playing court traction, a foamed polyurethane, injection molded midsole in situ bonded by said polyurethane to both said outsole and to said upper, whereby said rubber outsole and polyurethane foam midsole combine to provide a relatively inexpensive, lightweight and flexible athletic shoe compressively conformable to the flexing foot with a flexible sole having strong court traction and long wear.
Claim 2
Dependent Claim
90 words
A flexible athletic shoe comprising: an upper including a lower edge adapted for bonding to polyurethane, a flexible rubber outsole conformable to the flexing foot and having an outer surface providing playing court traction, a foamed polyurethane, injection molded midsole in situ bonded by said polyurethane to both said outsole and to said upper, whereby said rubber outsole and polyurethane foam midsole combine to provide a relatively inexpensive, lightweight and flexible athletic shoe compressively conformable to the flexing foot with a flexible sole having strong court traction and long wear.
Claim 3
Dependent Claim
115 words
A method for manufacturing the athletic shoe of claim 1, comprising the steps of: (a) treating the upper surface of a preformed, rubber outsole to prepare it for bonding to polyurethane, (b) inserting said outsole, treated side up, in the bottom of a mold, (c) mounting an upper on a last, said upper having a lower edge adapted for bonding to polyurethane, (d) lowering the last and upper into the mold so as to be spaced above the rubber outsole, (e) injecting a charge of foamable polyurethane between the outsole and the last, (f) allowing the polyurethane to foam to form the midsole and to bond in situ with the rubber outsole and the upper.
Claim 4
Dependent Claim
59 words
The method of claim 2 further comprising the step of raising the outsole upward in the mold after injection of the polyurethane until the upper surface of the outsole engages a fin element extending into the mold around the periphery of the shoe, whereby the fin element prevents the polyurethane from spilling over the sides of the rubber outsole.
Claim 5
Dependent Claim
50 words
The method of claim 2 further comprising the steps of preparing the inner surface of the rubber outsole for bonding to the polyurethane by: (a) roughening the inner surface; (b) chlorinating the inner surface; (c) applying a cement that bonds to both rubber and polyurethane, and (d) drying the cement.
Claim 6
Dependent Claim
22 words
The method of claim 4 further comprising the step of heat-activating the cement prior to insertion of the outsole in the mold.
Claim 7
Dependent Claim
12 words
The method of claim 5 wherein said cement is a urethane type.
Claim 8
Dependent Claim
16 words
The shoe of claim 1 wherein said midsole has a density of between 0.40 and 0.75.
Claim 9
Dependent Claim
11 words
The shoe of claim 1 wherein said rubber includes natural rubber.
Claim 10
Dependent Claim
18 words
The shoe of claim 1 wherein said midsole has a honeycomb structure to increase compliance and reduce weight.
Claim 11
Dependent Claim
18 words
The shoe of claim 1 further comprising an insole laid over the top of said midsole after molding.
Claim 12
Dependent Claim
28 words
The shoe of claim 1 wherein said rubber sole has a tread pattern on its lower surface that includes flexible rubber projections with sharp corners for enhanced grip.
Claim 13
Dependent Claim
13 words
The shoe of claim 1 wherein said polyurethane is of the polyester type.
Claim 14
Dependent Claim
50 words
The shoe of claim 1 wherein said upper in situ bonded by said polyurethane to said flexible outsole comprises flexible sheet-form material bondable to polyurethane, said upper being of string-lasted form with said lower edge of said upper comprising stitching and string effectively in situ bonded to said rubber outsole.
References Cited (Backward Citations)
GB1126535A
Cited
US3549472A
Cited
US3510968A
Cited
DE2017719A1
Cited
US3793750A
Cited
GB1536901A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-01-20 | 1984-07-21 | 1985-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-20 | 1988-07-21 | 1989-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-20 | 1992-07-21 | 1993-01-20 | $7700.00 | Window Closed / Lapsed |