Abstract: A valve which is particularly suited for use as a vacuum relief valve in an industrial vacuum cleaning system and which the vacuum operator may quickly and easily open from any position throughout a full 360 degrees about the valve to cut off the suction at the intake end of the vacuum system suction hose in the event the hose becomes blocked or some part of the vacuum operator's body or clothes is accidentally sucked into the intake end.

Abstract: An adjustable supporting roller device has a roller bracket pivoted on a mounting bracket to be attached to an object to be supported, and a novel combination lead screw and follower assembly for releasibly securing the roller bracket in retracted position during handling and shipment of the object and adjustably extending the roller bracket for use.

Abstract: A supporting roller assembly for a sliding door has a downwardly spring loaded guide track engaging roller supported for vertical floating movement by a mounting bracket containing a limited stop plunger which is spring loaded downwardly against the roller carrier. The bracket is slotted and carries a clamp screw accessible from the side of the door for clamping the bracket firmly about the plunger to secure the plunger in a fixed position for limiting upward movement of the guide roller against the action of its spring.