Abstract: An apparatus for raising and lowering a windable, portable motion picture screen which has a sliding pole inserted into a vertical opening within a hollow support cylinder in such a way that the sliding pole can slide up and down within the cylinder. A lever member is provided on the upper portion of the supporting cylinder to force against the sliding pole within the cylinder and hold it in position. The sliding pole is provided with a rack portion on one side thereof and rack and pinion gear drive means are connected to the side of the supporting cylinder in such a manner that they engage the rack portion of the sliding pole to move it up and down within the supporting cylinder as the gears are rotated.

Abstract: Swivel castors being characterized by providing a supporting shaft at the lower part of the both-side supporting member of a metal fitting which is pivotally fixed to the bottom of a fixed vertical shaft, mounting said supporting shaft on one side-wall of a L-shaped supporting plate, inserting said supporting shaft into a slit which has an appropriate temporary stopping means on its both ends, pivotally supporting the L-shaped supporting plate by said supporting shaft, providing a supporting stand at the end of one side-wall of said L-shaped supporting plate, mounting a supporting shaft on the other side-wall of the L-shaped supporting plate so as to support a rotary wheel, and when the L-shaped supporting plate turns in such direction as the end of one side-wall of the plate is raised and the supporting stand fixed thereto is stopped by an internal stopping edge of the metal fitting and thus the rotary wheel alone comes into contact with the ground, letting the metal fitting and the rotary wheel turn freely