Patent US4456251A successfully refreshed from Google Patents.
US4456251A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tennis ball rebound practice net
Assignee: PLASPACK KUNSTSTOFF & Co KG DR A CORP OF AUSTRIA GmbH
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Filing: 1980-08-18
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Granted: 1984-06-26
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Expires: 2000-08-18
Abstract
Abstract Tennis training equipment is constructed of a net supported by a frame. The net acts as a catch and return surface for a tennis ball hit against it and is made from vertically extending elastic elements and horizontally extending substantially inelastic elements. The tensions of the vertically extending elements may be varied by adjusting the frame in the vertical direction. The inclination of the net may be varied by tilting the frame. These features permit the flight characteristics of return balls to be controlled according to the abilities of a user of the equipment.
Inventors
- 👤 Anton Balaz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 07:03
CPC Classifications
A; A63; A63B; A63B69/00; A63B69/0097
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
288 words
A tennis training device comprising: a four-sided frame (4) adapted to be supported on the ground and having a pair of spaced vertical sides (5, 9) joined to a pair of spaced horizontal sides (17, 21); a net (8) having an outline similar to that of said frame (4) and being disposed inside said frame (4); a plurality of resilient means (19) connecting said net (8) to said frame (4); said net (8) having a first plurality of strings (6) extending in a vertical direction and being elastic, and having a second plurality of strings (7) extending in a horizontal direction and being inelastic; said net (8) adapted to act as a catch and return surface for a tennis ball impinging against said net (8); adjustment means (10, 11) on each vertical side (5, 9) of said frame (4) for adjusting the distance between the pair of spaced horizontal sides (17, 21) and thereby adjusting the tension in said first plurality of strings whereby the speed of return of the tennis ball is adjusted; a ground support for each vertical side (5, 9) including a stand (15) having a ground engaging part and a shaft (16) pivotally carrying its adjacent vertical side (5, 9), an inclined bar (14) pivotally connected at one end to said stand (15), and releasable clamp means (12) mounted on said adjacent vertical side (5, 9) in spaced vertical relation above said shaft (16), said bar (14) having an opposite end passing through said clamp means (12) whereby movement of said bar (14) relative to said clamp means (12) effects adjustment of the angle of inclination of said frame (4) relative to the ground to select the direction of return of the tennis ball.
Claim 2
Dependent Claim
288 words
A tennis training device comprising: a four-sided frame (4) adapted to be supported on the ground and having a pair of spaced vertical sides (5, 9) joined to a pair of spaced horizontal sides (17, 21); a net (8) having an outline similar to that of said frame (4) and being disposed inside said frame (4); a plurality of resilient means (19) connecting said net (8) to said frame (4); said net (8) having a first plurality of strings (6) extending in a vertical direction and being elastic, and having a second plurality of strings (7) extending in a horizontal direction and being inelastic; said net (8) adapted to act as a catch and return surface for a tennis ball impinging against said net (8); adjustment means (10, 11) on each vertical side (5, 9) of said frame (4) for adjusting the distance between the pair of spaced horizontal sides (17, 21) and thereby adjusting the tension in said first plurality of strings whereby the speed of return of the tennis ball is adjusted; a ground support for each vertical side (5, 9) including a stand (15) having a ground engaging part and a shaft (16) pivotally carrying its adjacent vertical side (5, 9), an inclined bar (14) pivotally connected at one end to said stand (15), and releasable clamp means (12) mounted on said adjacent vertical side (5, 9) in spaced vertical relation above said shaft (16), said bar (14) having an opposite end passing through said clamp means (12) whereby movement of said bar (14) relative to said clamp means (12) effects adjustment of the angle of inclination of said frame (4) relative to the ground to select the direction of return of the tennis ball.
Claim 3
Dependent Claim
24 words
A tennis training device as claimed in claim 1 wherein said net (8) has a horizontally extending color division to define a serving height.
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) | 1987-06-26 | 1987-12-26 | 1988-06-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-06-26 | 1991-12-26 | 1992-06-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-06-26 | 1995-12-26 | 1996-06-26 | $7700.00 | Window Closed / Lapsed |