Patent US4355803A successfully refreshed from Google Patents.
US4355803A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Tennis racquet with variable center of gravity and balance
Assignee: COIN-OPERATED EXERCISE EQUIPMENT Co Inc
•
Filing: 1980-12-22
•
Granted: 1982-10-26
•
Expires: 2000-12-22
Abstract
Abstract A tennis racquet with variable center of gravity and balance which comprises (a) a head, a handle and a grip, with the handle comprised of two side frames, (b) a weighted mechanism slidably mounted between the two side frames, and (c) ball and detent means between the weighted mechanism and the side frames for readily maintaining the position of the weighted mechanism at intermediate positions between head and grip as the weighted mechanism is slid back and forth between the head and the grip, thereby shifting the center of gravity and the balance toward the head or the grip.
Inventors
- 👤 Lord Rama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 07:55
CPC Classifications
A; A63; A63B; A63B60/00; A63B60/02; A63B49/00; A63B49/02; A63B49/08; A63B49/12; A63B60/04; A63B60/06; A63B60/22; A63B60/24; A63B60/08; A63B60/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
318 words
A tennis racquet comprised of (a) a head, a handle and a grip, with the handle comprised of two side frames, (b) a weighted mechanism slidably mounted between the two side frames, (c) ball and detent means comprised of a series of correspondingly placed detent holes in the side frames adjacent to the sides of the weighted mechanism and a ball positioned between each side frame and the adjacent side of the weighted mechanism, (d) means for readily maintaining the position of the weighted mechanism at intermediate positions between the head and grip comprised of cam means in which the cam is cross-shaped and is slidably located in a detent box, which in turn is slidably located within the weighted mechanism, said box having a detent hole on each side and said box being spring-loaded longitudinally against the ends of the weighted mechanism, said cross-shaped cam being attached at the intersection of the two arms of said cross to the gripper plates of the weighted mechanism, so that the cam moves in unison with the gripper plates when said weighted mechanism is moved in the direction of the head or grip of the racquet by manually gripping said gripper plates, but the detent box is delayed in moving in said direction, thereby allowing each ball, which at rest was maintained in a detent in the adjacent side frame by the transverse cross-arm of the cross-shaped cam, to recede further into the corresponding detent hole in the detent box as movement brings the longitudinal section of the cross-shaped cam opposite the detent hole of the detent box; and the spring-loading of the detent box bringing the transverse cross-arm of said cross-shaped cam adjacent to each ball thereby forcing each ball into the detent in the side frame adjacent to it and maintaining the weighted mechanism where it is located between head and grip when the manual movement is stopped.
Claim 2
Dependent Claim
318 words
A tennis racquet comprised of (a) a head, a handle and a grip, with the handle comprised of two side frames, (b) a weighted mechanism slidably mounted between the two side frames, (c) ball and detent means comprised of a series of correspondingly placed detent holes in the side frames adjacent to the sides of the weighted mechanism and a ball positioned between each side frame and the adjacent side of the weighted mechanism, (d) means for readily maintaining the position of the weighted mechanism at intermediate positions between the head and grip comprised of cam means in which the cam is cross-shaped and is slidably located in a detent box, which in turn is slidably located within the weighted mechanism, said box having a detent hole on each side and said box being spring-loaded longitudinally against the ends of the weighted mechanism, said cross-shaped cam being attached at the intersection of the two arms of said cross to the gripper plates of the weighted mechanism, so that the cam moves in unison with the gripper plates when said weighted mechanism is moved in the direction of the head or grip of the racquet by manually gripping said gripper plates, but the detent box is delayed in moving in said direction, thereby allowing each ball, which at rest was maintained in a detent in the adjacent side frame by the transverse cross-arm of the cross-shaped cam, to recede further into the corresponding detent hole in the detent box as movement brings the longitudinal section of the cross-shaped cam opposite the detent hole of the detent box; and the spring-loading of the detent box bringing the transverse cross-arm of said cross-shaped cam adjacent to each ball thereby forcing each ball into the detent in the side frame adjacent to it and maintaining the weighted mechanism where it is located between head and grip when the manual movement is stopped.
Claim 3
Dependent Claim
52 words
A tennis racquet as claimed in claim 1 in which there is additionally present (e) a rod of uniform cross section which is longitudinally located between the two side frames and on which the weighted mechanism slides by means of a longitudinal passage of similar cross section as that of the rod.
Claim 4
Dependent Claim
44 words
A tennis racquet as claimed in claim 1 in which there are resilient bumpers on that part of the head and that part of the grip against which the ends of the weighted mechanism impact as limits to the travel of the weighted mechanism.
References Cited (Backward Citations)
US1587918A
Cited
GB218423A
Cited
US2546140A
Cited
US3315532A
Cited
US4027881A
Cited
US3931968A
Cited
US4052060A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-10-25 | 1986-04-26 | 1986-10-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-10-25 | 1990-04-26 | 1990-10-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-10-25 | 1994-04-26 | 1994-10-26 | $7700.00 | Window Closed / Lapsed |