Abstract: A supplemental warning apparatus for school buses which is mounted on the roof of the bus in a vertical plane spaced above the usual warning sign which is carried on the side of the bus, the warning apparatus including a display member carried by a base which display member is shiftable between a retracted position and an upright vertically extended warning position. The supplemental warning apparatus may be coupled with the warning sign assembly on the side of the school bus; the passenger door of the school bus; or may be directly operated by the driver of the bus, all to the end that a warning is given from the roof of the bus which can be seen by surrounding traffic when the view of the normal warning sign on the side of the bus is blocked by such traffic.

Abstract: A mirror apparatus includes a flexible mirror mounted in a frame and a shuttle assembly shiftable along a generally upright axis having a cam element for selectively engaging a cam follower coupled with the rear face of the mirror in order to flex the mirror outwardly.

Abstract: An air return system for a rotatable rack baking oven having a heat source and a blower associated therewith for providing a flow of heated air across a baking chamber of the oven. The outlet end of the blower is connected via ductwork to an air outlet vent which introduces the heated air into the baking chamber. The air outlet vent includes a lattice of fixed vanes which are elongated in the direction of intended air flow. This arrangement channels the heated air to exit normal to the outlet vent to maintain a well defined column of air with less turbulence. An air return vent is located opposite the air inlet vent and is operatively associated with the heating means and the inlet side of the blower. The air return vent includes a panel having a plurality of holes through which the air may be drawn. A number of return holes in the return vent are blocked such that their numbers vary in inverse proportion to the drawing force produced by the inlet of the blower.

Abstract: An improved laboratory fume hood is the subject of the present invention. A cabinet structure presents an enclosed work area defined by sidewalls, a back wall, and an access opening. Each of the sidewalls presents first and second planar surfaces disposed in spaced parallel planes and interconnected by a third surface disposed at an acute angle relative to the plane of one of the first two surfaces. This third surface provides a mounting area for hose connectors which increases the effective work area and reduces the danger of clothing catching on the hose connectors. A vertically mounted sash covers the access opening and is movable between a lowered closed position and a raised open position. A fixture mounted in front of the sash provides means for mounting a light source. A removable cover on the side of the sash opposite the work area cooperates with the sash to define an air duct for directing add air into the access opening.