Tennis racket

A complete tennis racket comprising at least a frame having a head portion supporting a string netting in a plane, and a handle portion having a grip portion suitably adapted for the hand to grip, said netting having a length along the longitudinal axis of said frame greater than 9 inches and a width along an axis perpendicular to said axis greater than 7.5 inches;

• said racket having a weight W in ounces;
• a center of percussion located at a distance C.sub.p in inches from the end of the grip portion, when tested in accordance with test 4 of FIG. 40 herein before defined, said center of percussion taken about a pivot located at the end of the grip portion, said pivot having an axis perpendicular to the longitudinal axis of said racket and parallel to the plane of said string netting;
• said racket having a length L in inches from the end of the grip portion to the end of the head portion;
• said racket having a center of gravity located at a distance C.sub.g in inches from the end of the grip portion;
• said racket having a first moment of inertia I.sub.s in ounce inches squared about said pivot, and I.sub.s is directly proportional to the product of C.sub.p, C.sub.g, W, given by the formula I=(C.sub.p)(C.sub.g)(W);
• said racket characterized in that the magnitude of C.sub.p is greater than 18.75 inches, and the weight W is less than 10.7 ounces.

A complete tennis racket comprising at least a frame having a head portion supporting a string netting, and a grip portion suitably adapted for the hand to grip;

• said racket with said frame supporting a string netting having a weight W in ounces, and a center of gravity located at a distance C.sub.g in inches from the end of the grip portion, said racket having a length L in inches from the end of the grip portion to the end of the head portion;
• said racket characterized in that the magnitude of the said distance C.sub.g divided by the said length L given by the formula C.sub.g /L is greater than 0.56;
• and said racket has a weight W less than 10.7 ounces;
• and the ratio of W/L is less than 0.4.

A complete tennis racket comprising at least a frame having a head portion supporting a string netting and a grip portion suitably adapted for hand to grip;

• said racket having a weight distribution providing a first moment of inertia I.sub.s in ounce inches squared about a pivot located at the end of the grip portion, said pivot having an axis perpendicular to the longitudinal axis of said racket running from the center of the head portion end to the center of the grip portion end, and parallel to the plane of said string netting, and a second moment of inertia I.sub.a in ounce inches squared about said longitudinal axis;
• and said racket having a center of gravity located at a distance C.sub.g from the end of the grip portion;
• and said racket having a length L from the end of the grip portion to the end of the head portion;
• said racket characterized in that the magnitude of the said distance C.sub.g divided by the magnitude of the said distance L given by the formula C.sub.g /L is greater than 0.56;
• and the magnitude of the moment of inertia I.sub.a divided by the magnitude of the said moment of inertia I.sub.s given by the formula I.sub.a /I.sub.s is greater than 0.20.

A complete tennis racket comprising at least a frame having a head portion supporting a string netting, and a grip portion suitably adapted for the hand to grip;

• said racket having a weight W in ounces, a center of percussion located a distance C.sub.p in inches from the end of the grip portion, when tested in accordance with test 4 of FIG. 40 herein before defined, said center of percussion taken about a pivot located at the end of the grip portion, said pivot having an axis perpendicular to the longitudinal axis of said frame and parallel to a plane containing the surface of the frame;
• said racket having a length L in inches from the end of the grip portion to the end of the head portion;
• said racket having a center of gravity located at a distance C.sub.g in inches from the end of the grip portion;
• said racket characterized in that the magnitude of the said distance C.sub.g divided by the magnitude of the said distance C.sub.p given by the formula C.sub.g /C.sub.p is greater than 0.80 and the magnitude of the weight W is less than 10.7 ounces.

A tennis racket having great rigidity and strength with a minimum of weight comprising a head member and a handle member;

• said head member being an elongated hollow tubular metal strip having a center portion and two adjacent end portions shaped to partially inclose a space, said head member adapted to support a string netting in a plane;
• said handle member being a thin wall aluminum alloy tube having a yield strength greater than 55,000 pounds per square inch, said wall having a thickness less than 0.025 inches and said tube having a grip portion, and a shaft portion, said grip portion suitably formed for the hand to grip and said shaft portion gradually formed along the length toward the head member into a crossectional shape having an upper wall and a lower wall and two side walls, said walls being substantially planar and said side walls being substantially perpendicular to said upper and lower walls;
• said end portions of the head member having a crossectional shape to provide an upper surface and a lower surface located at a distance from a plane bisecting the head member lengthwise and said plane being parallel to the plane of said string netting;
• and said upper and lower walls of said shaft portion being located at substantially the same distance from said plane, and said upper and lower walls of the shaft portion being fastened to the said upper and lower surfaces of the end portions of said head member;
• and wherein the portion of said handle member having an axial length of 14 inches from the handle end of the racket, has a weight less than 3.0 ounces, and the weight of the racket extending beyond the said length of 14 inches is greater than 6.0 ounces.

A tennis racket comprising a head member and a handle member;

• said head member being an elongated metal strip having a center portion and two adjacent end portions shaped to partially inclose a space, said head member adapted to support a string netting in a plane;
• said handle member being a thin wall tube having located at a first end a grip portion, said grip portion suitably formed for the hand to grip and said tube generally formed along the length toward the second end portion into a crossectional shape having an upper wall and a lower wall located at a substantial distance from a plane bisecting said handle member lengthwise and said plane being parallel to the plane of said string netting, said second end portion being fastened to the said end portions of the said head member;
• said head member having the center portion substantially straight and lying perpendicular to a first axis, said axis running longitudinally from the center of the head end of the racket to the center of the handle end, and the said two adjacent end portions each substantially straight and forming corners with the center portion, and having the said end portions directed to converge toward a location in the second end portion of said handle member;
• a second axis perpendicular to the said first axis, said second axis being at a distance of 3.0 inches from the head end of the racket, said second axis intersecting said head member at locations, said locations being at the surface of said head member laterally outermost from said first axis, and the distance between said locations being greater than 9.0 inches;
• a third axis starting at one of the said locations on said head member, and running toward a point on the said first axis, said point being at a distance of 19 inches from the head end of the racket;
• a first plane being perpendicular to the said first axis and containing the said second axis, and a second plane being perpendicular to the said first axis and being located at a distance of 16.5 inches from the head end of the racket, and the portion of the racket lying between said first and second planes having a surface laterally outermost from said third axis, said surface being laterally on the same side of the first axis as the third axis, and said surface being at a maximum distance from said third axis less than 0.75 inches.

A tennis racket having great rigidity and light weight comprising a head member, a throat member, and a handle member;

• said head member being an elongated hollow tubular metal strip having a center portion and two adjacent end portions shaped to partially inclose a space, said head member adapted to support a string netting in a plane;
• said handle member being a thin wall aluminum alloy tube having a yield strength greater than 55,000 pounds per square inch and said wall having a thickness less than 0.025 inches and said tube having a grip portion and a shaft portion, said grip portion suitably formed for the hand to grip and said shaft portion gradually formed along the length toward the head member into a crossectional shape having an upper wall and a lower wall and two side walls, said upper and lower walls lying parallel to the plane of said string netting and said sidewalls lying perpendicular to said plane and said walls being substantially planar;
• said end portions of said head member having a crossectional shape having an upper surface and a lower surface located at a distance from a plane bisecting said head member lengthwise and said plane being parallel to the plane of said string netting;
• and said upper and lower walls of said shaft portion being located at substantially the same distance from said plane bisecting said head member lengthwise;
• and said throat member comprising a separate first planar sheet of thin wall metal having a portion fastened to the exterior of said upper wall of the shaft portion of said handle member and another portion of said first sheet fastened to the said upper surface of said head member, and a second separate planar sheet of thin wall metal having a portion fastened to the exterior of the said lower wall of the shaft portion of the handle member, and another portion of said second sheet fastened to the lower surface of said head member;
• and wherein the portion of said handle member having an axial length of 14 inches from the handle end of the racket has a weight less than 3.0 ounces, and the weight of the racket extending beyond the said length of 14 inches is greater than 6.0 ounces.

A tennis racket having rigidity and light weight comprising a head member, a throat member, and a handle member;

• said head member being an elongated hollow tubular metal strip having a center portion and two adjacent end portions shaped to partially inclose a space, said head member adapted to support a string netting in a plane;
• said handle member being a thin wall aluminum alloy tube having a yield strength greater than 55,000 pounds per square inch and said wall having a thickness less than 0.025 inches and said tube having a grip portion suitably formed for the hand to grip and a shaft portion gradually formed along the length toward the head member into a crossectional shape having a planar upper wall and a planar lower wall and two planar side walls, said upper and lower walls lying parallel to the plane of said string netting and said side walls lying perpendicular to said upper and lower walls;
• said end portions of said head member having a crossectional shape having an upper surface and a lower surface located at a distance from a plane bisecting said head member lengthwise and said plane being parallel to the plane of said string netting;
• and said upper and lower walls of said shaft portion being located at substantially the same distance from said plane bisecting said head member lengthwise;
• and said throat member comprising a sheet of thin wall material formed into a substantially u-shaped crossection having a first planar side opposing a second planar side and a third substantially planar side therebetween, said third side being straight in a direction perpendicular to a plane passing through the longitudinal axis of said racket, said plane being perpendicular to the plane of said string netting;
• said first and second sides being fastened to the said upper and lower surfaces of the said end portions of said head member and said first and second sides lying exterior to and being fastened to the said upper wall and lower wall of said shaft portion of said handle member, and the third side of said throat member adapted to support said string netting.

A tennis racket comprising at least a head portion, a throat portion, and a grip portion;

• said head portion being an elongated strip of material shaped to partially inclose a space for a string netting, said head portion adapted to support said string netting;
• said head portion comprising a center portion and two adjacent side portions, said center portion being substantially straight and placed perpendicular to a first axis running longitudinally from the center of the head portion to the center of the grip portion end, and the two adjacent side portions being substantially straight and forming corners with the center portion and said side portions directed to converge toward the throat portion of said racket;
• a second axis perpendicular to the said first axis, said second axis being at a distance of 3.0 inches from the head end of the racket, said second axis intersecting said head portion at locations, said locations being at the surface of said head portion laterally outermost from said first axis and the distance between said locations being greater than 9.0 inches, a third axis starting at one of the said locations on said head portion, and running toward a point on the said first axis said point being at a distance of 19 inches from the head end of the racket;
• a first plane being perpendicular to said first axis and containing said second axis, and a second plane being perpendicular to the said first axis and being located at a distance of 16.5 inches from the head end of the racket, and the portion of the racket lying between said first and second planes having a surface laterally outermost from said third axis, said surface being laterally on the same side of the first axis as the third axis and said surface being at a maximum distance from said third axis less than 0.75 inches;
• and said material of said head portion having a modulus of elasticity in tension greater than 2.5.times.10.sup.6 pounds per square inch and said material having a yield strength in tension greater than 15.times.10.sup.3 pounds per square inch.