Abstract: A wrist exercise includes a casing rotatably receiving a rotor therein. The casing defines slots that are aligned in pair. The rotor has axially aligned rotation shafts respectively and rotatably received in holes defined in the casing for rotatably supporting the rotor inside the casing. A drive roller is mounted to one of the rotation shafts. A drive bar is partially and movable received in the casing through the aligned slots to drivingly engage the drive roller whereby by forcibly pulling the drive bar out of the casing, the drive roller is caused to drive an initial rotation of the rotor with a high rotational speed.

Abstract: A rotor is rotatably received in a casing to form a wrist exerciser. The rotor includes a spherical body defining a bore in which an inner flange is formed. First and second weight members are received in the bore on opposite sides of the flange. The weight members have inner end portions releasably attached to opposite surfaces of the flange. Through holes are defined in the first and second weight members to receive an axle of which ends project beyond opposite ends of the body to rotatably engage a support ring of the casing.

Abstract: A wrist exercise includes a casing defining an interior space rotatably receiving a rotor. The casing includes upper and lower casing members. The upper casing member has a first mating edge forming a first mating device. The lower casing member has a second mating edge forming a second mating device for mating the first mating device to attach the lower casing member to the upper casing member whereby a circumferential groove is defined between the first and second mating edges. A first retention ring is at least partially fit over the upper and lower casing members and forms an inwardly-projecting portion fit into the groove to securely retain the upper and lower casing members in position.

Abstract: A wrist exercise includes a casing rotatably receiving a rotor therein. The casing defines slots that are aligned in pair. The rotor has axially aligned rotation shafts respectively and rotatably received in holes defined in the casing for rotatably supporting the rotor inside the casing. A drive roller is mounted to one of the rotation shafts. A drive bar is partially and movable received in the casing through the aligned slots to drivingly engage the drive roller whereby by forcibly pulling the drive bar out of the casing, the drive roller is caused to drive an initial rotation of the rotor with a high rotational speed.

Abstract: A wrist exerciser includes a spherical hollow casing having a top opening. A ring is received within the casing and substantially coincident with a great circle of the casing. A rotor is rotatably received in the casing by being rotatably supported by the ring. The rotor has a circumferential groove defined in an outer surface thereof for receiving a rope wound around the rope. By manually pulling to unwind the rope through the top opening, the rotor is rotated in the casing. A number of light emitting diodes (LEDs) are arranged on the outer surface of the rotor in a predetermined fashion. A power supply device is mounted to the rotor and electrically connected to the LEDs via a microprocessor based control circuit for conducting on/off the LEDs in accordance with operation modes performed by the microprocessor. By making use of the persistency of human vision, a limited number of the LEDs may display complicated messages, including the rotational speed of the rotor.

Abstract: A wrist exerciser includes a spherical hollow casing having a top opening. A ring is received within the casing and substantially coincident with a great circle of the casing. A rotor is rotatably received in the casing by being rotatably supported by the ring. The rotor has a circumferential groove defined in an outer surface thereof for receiving a rope wound around the rope. By manually pulling to unwind the rope through the top opening, the rotor is rotated in the casing. A number of light emitting diodes (LEDs) are arranged on the outer surface of the rotor in a predetermined fashion. A power supply device is mounted to the rotor and electrically connected to the LEDs via a microprocessor based control circuit for conducting on/off the LEDs in accordance with operation modes performed by the microprocessor. By making use of the persistency of human vision, a limited number of the LEDs may display complicated messages, including the rotational speed of the rotor.

Abstract: A wrist exercise includes a casing defining an interior space rotatably receiving a rotor. The casing includes upper and lower casing members. The upper casing member has a first mating edge forming a first mating device. The lower casing member has a second mating edge forming a second mating device for mating the first mating device to attach the lower casing member to the upper casing member whereby a circumferential groove is defined between the first and second mating edges. A first retention ring is at least partially fit over the upper and lower casing members and forms an inwardly-projecting portion fit into the groove to securely retain the upper and lower casing members in position.