Abstract: A walking stick with a flexure spring to store energy from compression during the user's step, and release of the energy to aid in propelling the user forward, thereby reducing fatigue and enabling longer and faster walks.

Abstract: A rotatable charging apparatus includes a length extending between a first end and a second end, with the rotatable charging apparatus centered about an axis parallel to the length. The rotatable charging apparatus outer periphery forms N apparatus positions. One charging device is fixed to each of N−1 apparatus positions. The remaining (Nth) apparatus position is devoid of a charging device, thus forming an “empty” charging device position. A host printing machine selectively causes the rotatable charging apparatus to rotate about its axis thereby selectively position any of its N−1 charging devices to face a proximately-located photosensitive element. When a problem exists with the current charging device, or when the total number of operating hours of the current charging device exceeds a fixed threshold, the printing machine causes the rotatable charging apparatus to rotate from its current charging device to position a new charging device facing the photosensitive element.

Abstract: An apparatus and method that utilize a sensor circuit and a liquid supply to control resistance of a fluid carrier of an aquatron. The resistance of the fluid carrier or charging pad is maintained by controlling the loading or concentration of liquid in the charging pad. A comparison of the fluid or liquid level in the charging pad to the desired fluid level for the charging pad triggers the addition or reduction of fluid to the charging pad to achieve the desired fluid level and thus the desired resistance. A minimum fluid carrier resistance is required to prevent loading the power supply when charging over pinholes and scratches in the imaging surface.