Abstract: A tipping prevention unit that prevents tipping of an image forming apparatus includes shafts holding a wheel of the image forming apparatus, a shaft that abuts the image forming apparatus at a position higher than the shafts, and a shaft that contacts a floor surface on which the image forming apparatus is placed at a position further protruding to the outside of the image forming apparatus than the wheel of the image forming apparatus.

Abstract: A clutch and a workpiece support incorporating the same selectively restrict rotation of a rotatable member through the use of one or more rollers that are pinched between the outer surface of the rotatable member and corresponding convergent surfaces disposed on a housing opposing such outer surface. In effect, each roller is interposed between a surface on a fixed housing and an outer surface of a rotatable member such that rotation of the rotatable member rolls the roller toward a converging gap to restrict further rotation of the rotatable member. A biasing mechanism biases the roller toward the converging gap, and a release mechanism is utilized to quickly and efficiently decouple the roller from the rotatable member by biasing the roller in a direction away from the converging gap and thereby preventing the roller from inhibiting rotation of the rotatable member.