Abstract: A ventilating unit for mounting in the top wall of a vehicle that includes a frame and a panel movable between an open and a closed position in the frame. An operating mechanism is provided which includes linkages connected to opposite sides of the panel, and two electric motors connected to the linkages and independently operable to selectively raise either one, or both of the sides of the panel. At least one latching member may be included in the operating mechanism to assist in maintaining the panel in its closed position.

Abstract: A safety system which contains a crossing arm or the like which is mounted on a vehicle, such as a school bus, and normally carried at a retracted position adjacent the vehicle, and a sensor device for sensing the presence of children near the bus which operates in a coordinated fashion with the crossing arm. The sensor may operate either only when the crossing arm is in its retracted position or when the crossing arm is both in its retracted and operating positions.

Abstract: An actuating device for use in moving a school bus safety unit, such as a stop sign or crossing arm, between a retracted position adjacent the school bus, and an extended position projecting outwardly from the bus. The actuating device includes a drive motor and a friction-type slip clutch which permits the safety unit to be manually moved from its extended or retracted positions without damage to the drive arrangement for moving the safety unit, and several alternative control circuits may be utilized to automatically or semi-automatically return the safety unit to its retracted and/or extended positions if manually moved therefrom.

Abstract: An improved actuating device for school bus safety unit, such as crossing arms and the like, which includes an arrangement for driving and controlling the crossing arm in a continuous predetermined arcuate path of movement, with the safety device being moved continuously back and forth in a sweeping motion that provides a moving barrier in areas adjacent the school bus where children may be placed in an unsafe situation, such as immediately adjacent the front bumper of the bus which is outside of the normal line of vision of the school bus operator. In one embodiment, an extendable line is anchored to the bus at one or both ends, and an intermediate portion of the line is engaged by the moving safety unit, whereby the line itself creates a changing barrier as the safety unit sweeps through its path of movement.