Negative Poisson's ratio materials for racquets and golf tees
OwnerJoon Bu Parkinventor
Life of this patent
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Abstract
A racquet includes a handle; and a frame connected to an end of the handle, the frame defining a rounded interior space, the frame including a negative Poisson's ratio (NPR) foam material, in which the NPR foam material, and in which the frame has a Poisson's ratio of between 0 and −1; and a network of strings stretched across the rounded interior space defined by the frame. A golf tee includes an elongated stem; and a head disposed at an end of the elongated stem and shaped to receive a golf ball; in which at least a portion of the golf tee is formed of a negative Poisson's ratio (NPR) foam material, in which the portion of the golf tee has a Poisson's ratio of between 0 and −1, and in which the NPR foam material includes an NPR metal foam, an NPR ceramic foam, or an NPR-PPR composite foam.
Claims25
A racquet comprising:
- a frame defining a rounded interior space, the frame comprising a negative Poisson's ratio (NPR) portion comprising an NPR foam material, in which the NPR portion has a Poisson's ratio of between 0 and −1, the frame comprising a positive Poisson's ratio (PPR) portion comprising a PPR material, wherein dimples are defined on the frame of the racquet, wherein the dimples are irregularly spaced;
- a network of strings stretched across the rounded interior space defined by the frame, the network of strings comprising a PPR material;
- and
- a handle connected to an end of the frame, the handle comprising an NPR-PPR composite material, wherein the NPR-PPR composite material comprises a matrix composite including a matrix phase of NPR material with a reinforcement phase of PPR material including fibers and particles of PPR material.
A method of making a racquet, the method comprising:
- forming a frame of a racquet from a negative Poisson's ratio (NPR) foam material, in which the frame comprises an NPR portion, in which the NPR portion has a Poisson's ratio of between 0 and −1, the frame comprising a positive Poisson's ratio (PPR) portion comprising a PPR material, the forming including forming the frame to define a rounded interior space and to define dimples on the frame, wherein the dimples are irregularly spaced;
- stretching a network of strings across the rounded interior space defined by the frame, the network of strings comprising a PPR material, and
- in which the frame is connected to an end of a handle of the racquet, the handle comprising an NPR-PPR composite material, wherein the NPR-PPR composite material comprises a matrix composite including a matrix phase of NPR material with a reinforcement phase of PPR material including fibers and particles of PPR material.
A racquet comprising:
- a frame defining a rounded interior space, the frame comprising a negative Poisson's ratio (NPR) portion comprising an NPR foam material, in which the NPR portion has a Poisson's ratio of between 0 and −1, the frame comprising a positive Poisson's ratio (PPR) portion comprising a PPR material, wherein dimples are defined on the frame of the racquet, wherein the dimples are irregularly spaced;
- a network of strings stretched across the rounded interior space defined by the frame, the network of strings comprising a PPR material;
- and
- a handle connected to an end of the frame, the handle comprising an NPR-PPR composite material, wherein the NPR-PPR composite material comprises a laminar composite including alternating layers of NPR material and layers of PPR material, comprising at least two layers of NPR material and at least two layers of PPR material.
Dependencies are inferred from the claim text.