Embodiments of adjustable length golf clubs and methods of manufacturing adjustable length golf clubs are generally described herein. Other embodiments may be described and claimed.

The present invention relates to a practice swing bat and, particularly, to a bat which is capable of, during golf swing practice, calculating and displaying swing speed, virtual driving distance of each club, etc., and transmitting the same to a terminal so as to enable management of the same. To this end, the bat of the present invention comprises a swing measurement module.

The present invention relates to a practice swing bat and, particularly, to a bat which is capable of, during golf swing practice, calculating and displaying swing speed, virtual driving distance of each club, etc., and transmitting the same to a terminal so as to enable management of the same. To this end, the bat of the present invention comprises a swing measurement module.

One embodiment of an extendable and retractable tennis racquet contains a stringed area 01, throat 02, and shank 03 as one integral member. The handle is comprised of a shank inside of a hollow handle 05. A spring or flexible means 07 connects the shank to the hollow handle. When the racquet is swung, the centrifugal force generated pulls on the head assembly. The shank slides outward telescopically, thereby increasing the length of the racquet. At the end of the racquet swing, the restoring force of the spring overcomes the diminishing centrifugal force, which pulls the shank back to its retracted position. Other embodiments are described and shown.

One embodiment of an extendable and retractable tennis racquet contains a stringed area 01, throat 02, and shank 03 as one integral member. The handle is comprised of a shank inside of a hollow handle 05. A spring or flexible means 07 connects the shank to the hollow handle. When the racquet is swung, the centrifugal force generated pulls on the head assembly. The shank slides outward telescopically, thereby increasing the length of the racquet. At the end of the racquet swing, the restoring force of the spring overcomes the diminishing centrifugal force, which pulls the shank back to its retracted position. Other embodiments are described and shown.

A golf club shaft connection assembly comprising first and second shaft sections, male and female adaptors, a hollow retainer, a spring, and a plurality of balls is disclosed herein. The male and female adaptors are each attached to the first and second shaft sections, respectively, preferably with a permanent adhesive. The male adaptor comprises a protrusion that fits within a keyed interior of the female adaptor, and moving the hollow retainer towards the male adaptor reversibly fixes the two adaptors together, while moving the hollow retainer towards the female adaptor allows the male adaptor to be removed from the female adaptor.

An adjustable and releasably lockable shaft for sporting goods, such as lacrosse sticks, and a method for adjusting and releasably locking the length of sporting goods shafts, is disclosed. The device may include a first shaft and a second shaft, which may be connected through a connector component. The connector component may provide structural support for one or both shafts, resisting flexion and deformation during use. One or both shafts may be unlocked and removed from the connector component, allowing for easier travel and storage. Shafts may also be connected when desirable, such as for defensive lacrosse play, or disconnected when shorter devices are desired, such as for offensive lacrosse play. Other components and structures may also be attached using similar methods and structures.

A golf club length adjustment device for use in a golf club, including a first member affixed to a main shaft, a second member slideably coupled to the first member, the second member adapted to couple to a golf club grip, wherein the first member is configured to slide relative to the second member to change the length of the golf club; a locking system having a locked position and an unlocked position; wherein the locking system includes at least one locking member and a plurality of detents, wherein the locking member is configured to selectively engage at least one of the plurality of detents; wherein the first member is formed of a first material having a first density; wherein the locking member is formed of a second material having a second density; wherein the second density is greater than the first density.

The present invention relates to a ball game racket, a method for adjusting the length of the handle portion of a ball game racket and a handle shell for the handle portion of a ball game racket.

The present invention relates to a ball game racket, a method for adjusting the length of the handle portion of a ball game racket and a handle shell for the handle portion of a ball game racket.