Patent US4105203A successfully refreshed from Google Patents.
US4105203A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tennis trainer
Assignee: Individual
•
Filing: 1977-01-11
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Granted: 1978-08-08
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Expires: 1997-01-11
Abstract
Abstract A tennis trainer includes a generally L-shaped arm having a ball holder at one end and pivotally engaged to a support at the other. Impact against the ball in a direction axially along the ball-supporting section of the arm is initially absorbed by a resilient section of the other section of the arm. A housing on the support includes a slot through which the arm extends and a rotatable cylinder to which the arm is secured. Bias springs oppose rotation of the cylinder and hence the arm. The housing is mountable upside down to permit the trainer to be used for back hand practice or for left handed fore hand practice. Various bending of the arm and vertical positioning of the support permits the ball to be positioned at various heights and positions.
Inventors
- 👤 Tae Han Cho
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:25
CPC Classifications
A; A63; A63B; A63B69/00; A63B69/0073; A63B69/0091
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
263 words
Tennis training apparatus comprising: a free-standing support structure having a vertical axis; an arm member having first and second sections forming a generally L-shaped structure; pivotal engagement means securing an end of said first section inside said support structure to permit rotational movement of said arm member about said vertical axis; bias means in said support structure for biasing said arm member to a rest position and opposing rotational movement of said arm member; spring means located in said first section of said arm member for imparting axial resiliency to said first section; holder means located at an end of said second section for firmly holding a tennis ball in a position which is substantially centered with respect to said second section of said arm member; whereby impact against said tennis ball in a direction axially toward said second section of said arm member is initially partially absorbed by said spring means and then partially absorbed by said bias means; wherein said pivotal engagement means includes: a housing having outer side walls, a top wall and a bottom wall forming an enclosure, said outer side walls being positioned to surround said vertical axis and having a horizontally-extending slot defined therein; a hollow cylinder positioned inside said housing and coaxial with said vertical axis, said hollow cylinder being positioned for rotational movement about said vertical axis; and means securing said one end of said first section of said arm member to said hollow cylinder such that said first section extends radially outward from said vertical axis through the slot in said outer side walls.
Claim 2
Dependent Claim
263 words
Tennis training apparatus comprising: a free-standing support structure having a vertical axis; an arm member having first and second sections forming a generally L-shaped structure; pivotal engagement means securing an end of said first section inside said support structure to permit rotational movement of said arm member about said vertical axis; bias means in said support structure for biasing said arm member to a rest position and opposing rotational movement of said arm member; spring means located in said first section of said arm member for imparting axial resiliency to said first section; holder means located at an end of said second section for firmly holding a tennis ball in a position which is substantially centered with respect to said second section of said arm member; whereby impact against said tennis ball in a direction axially toward said second section of said arm member is initially partially absorbed by said spring means and then partially absorbed by said bias means; wherein said pivotal engagement means includes: a housing having outer side walls, a top wall and a bottom wall forming an enclosure, said outer side walls being positioned to surround said vertical axis and having a horizontally-extending slot defined therein; a hollow cylinder positioned inside said housing and coaxial with said vertical axis, said hollow cylinder being positioned for rotational movement about said vertical axis; and means securing said one end of said first section of said arm member to said hollow cylinder such that said first section extends radially outward from said vertical axis through the slot in said outer side walls.
Claim 3
Dependent Claim
42 words
The apparatus according to claim 1 wherein said bias means comprises further spring means positioned inside said hollow cylinder and connected to said support structure and to said hollow cylinder for opposing rotational motion of said hollow cylinder about said vertical axis.
Claim 4
Dependent Claim
107 words
The apparatus according to claim 2 wherein said support structure comprises: a plurality of telescopically related tubular members positioned coaxially about said vertical axis; means for securing said tubular members over a wide range of extended and retracted positions to permit selective adjustment of the height of said support structure; wherein said housing is secured to the uppermost of said tubular members with said hollow cylinder surrounding said uppermost tubular member; and wherein said further spring means comprises at least one helical spring wound about said uppermost tubular member and having one end secured to said uppermost tubular member and another end secured to said hollow cylinder.
Claim 5
Dependent Claim
104 words
The apparatus according to claim 3 wherein said support structure further comprises: a plurality of selectively retractable legs mounted at their upper ends for pivotal movement in respective vertical planes; a collar slidably mounted about the periphery of the lowermost tubular member; means for selectively securing said collar at various positions along the length of said lowermost tubular member; and a plurality of rods, one for each of said retractable legs, each having one end pivotally secured to said collar for rotational movement in a vertical plane and having another end which slidably engages a respective retractable leg at adjustable positions along that leg.
Claim 6
Dependent Claim
33 words
The apparatus according to claim 3 wherein said outer side walls of said housing form an outer cylinder, said slot extending over an arcuate angle of at least 180° in said outer cylinder.
Claim 7
Dependent Claim
32 words
The apparatus according to claim 5 wherein said housing is removably secured to said uppermost tubular member and is adapted to be re-positioned upside down and secured to said uppermost tubular member.
Claim 8
Dependent Claim
30 words
The apparatus according to claim 1 wherein said housing is removably secured to said support structure and is adapted to be re-positioned upside down and secured to said support structure.
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) | 1981-08-07 | 1982-02-06 | 1982-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-08-07 | 1986-02-06 | 1986-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-08-07 | 1990-02-06 | 1990-08-08 | $7700.00 | Window Closed / Lapsed |