Abstract: A modified construction for a non-linear or curved staircase employs a technique in which the treads for the staircase are initially cut to the required shape and size. Flexible plywood boards of the same length and height as the required stringers are then attached to the treads with the treads positioned in the required locations and orientations so as to create a rigid self-supporting structure formed by the flexible boards and the attached treads and risers where required. The self-supporting structuure is then finished by the attachment to the flexible boards of suitable laminations. House of treads have the laminations applied to the outer surface of the boards. Exposed end treads have the laminations applied to the inner side of the boards.

Abstract: A wafer pick up device is presented which may be used to pick up silicon wafers used in the semiconductor industry during the various stages of processing. Since the pick up device is made out of a high temperature and acid resistant material, it may be used to pick up hot wafers or to handle wafers being subjected to an acid bath. The device uses a sliding plate which slidably engages a closure channel and base plate. Two wafer holding pins fastened to an actuator bar portion of the sliding plate are used to engage a portion of the outer periphery of a wafer. A curved V-shaped groove at one end of the base plate engages another portion of the outer periphery of the wafer. The distance between the waver holding pins and curved V-shaped groove can be adjusted so that the wafer may be picked up by engaging the primary flat surface at the outer periphery of the wafer if desired. The actuator bar portion is wide enough to provide structural rigidity and facilitate holding the wafer securely in place.