US4044179A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Playing surface for athletic games
Assignee: Mod-Sod Sport Surfaces
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Filing: 1975-11-18
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Granted: 1977-08-23
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Expires: 1995-11-18
Abstract
Abstract A playing surface for athletic games, such as tennis, comprising a flat, firm subsurface, a pile fabric disposed on the subsurface comprising a relatively flexible, moisture-impermeable backing and normally generally upstanding pile elements resembling grass, a compacted layer of granular mineral material disposed among the pile elements on the backing to a depth from about 75% to substantially equal to the length of the pile elements, the mineral layer comprising less than 10% clay and further comprising a quantity of moisture retaining material sufficient to maintain the moisture content of the mineral layer above about 3% by weight under normal climatic conditions.
Inventors
- 👤 Frederick T. Haas, Jr.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 02:03
CPC Classifications
E; E01; E01C; E01C13/00; E01C13/08; E01C13/02; Y; Y10; Y10T; Y10T428/00; Y10T428/23907; Y10T428/23921; Y10T428/23979; Y10T428/25; Y10T428/259
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
143 words
A playing surface for athletic games comprising: a. a substantially flat, firm subsurface; b. a pile fabric disposed on said subsurface comprising a relatively flexible, substantially moisture-impermeable backing and normally generally upstanding pile elements resembling grass; the length of said pile elements lying in the range from about 1/2 to about 11/2 inches; c. A compacted layer of weather-resistant, mineral, granular material disposed among said pile elements on said backing; the depth of said granular material layer lying in the range from about 75% to substantially equal to the length of said pile elements and being substantially uniform over the entire area of said playing surface; d. said mineral material comprising less than 10% clay and further comprising a quantity of moisture retaining material sufficient to maintain the moisture content of said mineral material above about 3% by weight under normal climatic conditions.
Claim 2
Dependent Claim
143 words
A playing surface for athletic games comprising: a. a substantially flat, firm subsurface; b. a pile fabric disposed on said subsurface comprising a relatively flexible, substantially moisture-impermeable backing and normally generally upstanding pile elements resembling grass; the length of said pile elements lying in the range from about 1/2 to about 11/2 inches; c. A compacted layer of weather-resistant, mineral, granular material disposed among said pile elements on said backing; the depth of said granular material layer lying in the range from about 75% to substantially equal to the length of said pile elements and being substantially uniform over the entire area of said playing surface; d. said mineral material comprising less than 10% clay and further comprising a quantity of moisture retaining material sufficient to maintain the moisture content of said mineral material above about 3% by weight under normal climatic conditions.
Claim 3
Dependent Claim
35 words
A playing surface as recited in claim 1 wherein said level subsurface comprises an underlayer of crushed rock and an overlayer of compacted material selected from the class consisting of sand, clay and mixtures thereof.
Claim 4
Dependent Claim
32 words
A playing surface as recited in claim 1 wherein said granular mineral material comprises sand having a particle size lying between 200 U.S. screen mesh size and 12 U.S. screen mesh size.
Claim 5
Dependent Claim
67 words
A playing surface as recited in claim 3 wherein said granular mineral material comprises a lower sublayer of fine sand, having a particle size lying in the range from 200 U.S. screen mesh size to 40 U.S. screen mesh size and an upper sublayer of medium sand having a particle size lying in the range from 70 U.S. screen mesh size to 20 U.S. screen mesh size.
Claim 6
Dependent Claim
16 words
A playing surface as recited in claim 1 wherein said moisture retaining material comprises expanded vermiculite.
Claim 7
Dependent Claim
22 words
A playing surface as recited in claim 1 further comprising a surface modifying material layer on top of said granular mineral material.
Claim 8
Dependent Claim
49 words
A playing surface as recited in claim 1 wherein the length of said pile elements lies between about 3/4 and about 1 inch and wherein the depth of said granular mineral material lies in the range from about 85% to about 95% of the length of the pile elements.
Claim 9
Dependent Claim
24 words
A playing surface as recited in claim 1 wherein the clay content of said granular mineral material lies between about 1 and about 2%.
Claim 10
Dependent Claim
25 words
A playing surface as recited in claim 1 wherein said moisture retaining material in said granular mineral material comprises a sublayer disposed adjacent said backing.
Claim 11
Dependent Claim
20 words
A playing surface as recited in claim 1 wherein said moisture retaining material is interspersed throughout said granular mineral material.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-08-22 | 1981-02-21 | 1981-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-08-22 | 1985-02-21 | 1985-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-08-22 | 1989-02-21 | 1989-08-23 | $7700.00 | Window Closed / Lapsed |