Abstract: Systems and methods are disclosed for selectively allowing or preventing output of laser pulses. In some embodiments, a laser system comprises a shutter and a shutter motor. The shutter motor is configured to move the shutter in an alternating manner between a first position in which output of laser electromagnetic radiation is allowed a second position in which output of laser electromagnetic radiation is prevented.

Abstract: A roller skate shoe includes a shoe base having two receiving cavities provided thereunder at a front portion and a rear portion of the shoe base respectively, a roller arrangement fittedly received in each receiving cavity including a supporting frame securely mounted on a ceiling of the receiving cavity having a supporting member extended downwardly, a T-shaped wheel frame including a vertical wheel arm rotatably mounted on the supporting member and a horizontal wheel axle for rotatably supporting two wheels at two ends thereof, and a resilient element for applying an urging pressure against the wheel frame so as to normally retain the wheel frame slid out of the receiving cavity, and a locker means for securely locking the wheel frame in a rotatably movable manner selectively between a folded position and an unfolded position.

Abstract: A roller skate shoe includes a shoe base having two receiving cavities provided thereunder at a front portion and a rear portion of the shoe base respectively, a roller arrangement fittedly received in each receiving cavity including a supporting frame securely mounted on a ceiling of the receiving cavity having a supporting member extended downwardly, a T-shaped wheel frame including a vertical wheel arm rotatably mounted on the supporting member and a horizontal wheel axle for rotatably supporting two wheels at two ends thereof, and a resilient element for applying an urging pressure against the wheel frame so as to normally retain the wheel frame slid out of the receiving cavity, and a locker means for securely locking the wheel frame in a rotatably movable manner selectively between a folded position and an unfolded position.

Abstract: A roller skate shoe incorporates a wheel lock releaser arrangement which includes a locking member movably attached to a shaft for locking up a wheel frame from being slid rotatably with respect to a supporting frame of the roller skate shoe. The locking member includes an operation button extended to an exterior of a shoe base for operating the locking member. A resilient member is adapted for applying an urging pressure against the locking member so as to normally retain the locking member in a locking position. At the locking position, the locking member is engaged with the wheel frame such that the wheel frame is locked for a rotational movement. For operating the roller skate shoe, a player must press the operation button inwardly to disengage the locking member with the wheel frame, so as to unlock the wheel frame from being slid out of the receiving cavity.