Abstract: A check valve assembly for the forced gas cooling system of a vacuum heat treating furnace is disclosed. The check valve assembly includes a check valve for installation on the exterior of a hot zone wall in a vacuum heat treating furnace. The check valve includes a valve body forming an inlet, an outlet, and a channel extending longitudinally through the valve body. The valve body has an inner wall that forms a recess near the inlet. The channel contains a flap pivotally supported on a shaft that extends through the recess. The flap pivots in and out of the channel to permit a cooling gas to flow through the valve body in one direction while substantially preventing the flow of gas through the valve body in the opposite direction. The flap is operable between a closed position in which the flap extends into the channel to obstruct the channel, and an open position in which the flap is pivoted out of the channel and into the recess.

Abstract: A temporary extension enclosure for motor vehicles having enclosed bodies, includes a tent-like sheath erected atop a floorboard which extends horizontally from the doorway of the loading door of such vehicles. The floorboard is arranged to act as an extension of the floor of the vehicle body and is supported on and releasably secured in position by brackets at the lower frame of the loading door and by hangers affixed to the laterally opening door panels which normally close the doorway itself. The tent-like sheath may be attached to the vehicle body by snap closures and may be provided with a door, formed by tent-flaps, and with windows.