Tennis racquet with adjustable frame isolation

A racquet comprising:

• an outer frame defined by a generally hoop shaped portion with a handle extending therefrom;
• an inner frame positionable within said outer frame having a string bed formed from a plurality of cross string elements and a plurality of main string elements;
• and a means for isolating and securing said inner frame to said outer frame constructed and arranged to allow for sway space deflection and to control overall in-plane stiffness between 30 lbs/in and 800 lbs/in and overall out-of-plane stiffness between 70 lbs/in and 600 lbs/in, said isolators' in-plane stiffness is adjusted to include a player's racquet preparation motion which results in in-plane g-loads applied to said inner frame and pre-loads the in-plane stiffness of the isolators, resulting in g-load stored energy of the isolators, which said energy combines with stored energy of the in-plane motion of said isolators caused during ball impact, with the combined energy then returned to the ball to optimize ball rebound spin, said means for isolating and securing said inner frame to said outer frame provides a combined and coordinated out-of-plane stiffness of isolators with the string bed only out-of-plane stiffness, whose coordinated combined motion results in a nearly normal rebound of a tennis ball, independent of any ball impact eccentricity to a center of the string bed and is adjustable and combines out-of-plane stiffness, string bed stiffness, and in-plane stiffness to provide increased spin to a ball impacting said string bed wherein any specific isolator is adjusted, using significantly 3×-10× larger in-plane stiffnesses compared to other isolators, which said stiffnesses effectively makes a connection between the inner and outer frame, at that isolator position, a door-hinge pin connection between two structures, where the hinge's rotation axis is normal to the string-bed at that isolator position, which said isolator adjustment allows the inner frame, relative to the outer frame, to achieve a rigid-body in-plane-of-the-string-bed rotation about a hinge line.

A racquet comprising:

• an outer frame defined by a generally hoop shaped portion with a handle extending therefrom;
• an inner frame positionable within said outer frame having a string bed formed from a plurality of cross string elements and a plurality of main string elements;
• and a means for isolating and securing said inner frame to said outer frame constructed and arranged to allow for sway space deflection and to control overall in-plane stiffness between 30 lbs/in and 800 lbs/in and overall out-of-plane stiffness between 70 lbs/in and 600 lbs/in, said isolators' in-plane stiffness is adjusted to include a player's racquet preparation motion which results in in-plane g-loads applied to said inner frame and pre-loads the in-plane stiffness of the isolators, resulting in g-load stored energy of the isolators, which said energy combines with stored energy of the in-plane motion of said isolators caused during ball impact, with the combined energy then returned to the ball to optimize ball rebound spin, said means for isolating and securing said inner frame to said outer frame provides a combined and coordinated out-of-plane stiffness of isolators with the string bed only out-of-plane stiffness, whose coordinated combined motion results in a nearly normal rebound of a tennis ball, independent of any ball impact eccentricity to a center of the string bed and is adjustable and combines out-of-plane stiffness, string bed stiffness, and in-plane stiffness to provide increased spin to a ball impacting said string bed wherein any specific isolator is adjusted, translational stiffness of two specific isolators, positioned diametrically opposite each other relative to a geometric center or center of mass of the inner frame, are adjusted using significantly 3×-10× larger in-plane stiffnesses compared to other isolators, which in-plane perpendicular stiffness component of each diametrically opposite isolator is 3×-10× larger than any other isolator stiffness, thereby allowing a connection between the inner and outer frame to effectively move along a diameter direction in the plane of the inner frame, which said isolator adjustment allows the inner frame to achieve a spring-loaded in-plane rigid-body diametric-only motion relative to the outer frame.