Abstract: A polishing head includes a head housing having a first flange part that extends outward from an upper position of a circumferential surface of a cylindrical body and a second flange part that extends outward from a lower position of the circumferential surface, a membrane support ring that is sized to surround an outer circumference of the second flange part and has a third flange part that is formed at an upper end part thereof and located between the first flange part and the second flange part, a membrane that covers a lower end-side opening part of the membrane support ring and holds the wafer with a backing film pasted to a front surface thereof interposed therebetween, a retainer ring formed in a shape to surround an outer circumference of the substrate, and driving means that integrally horizontally rotates the head housing, the membrane support ring, and the retainer ring.

Abstract: A surgical knife having a body with a blade at one end is provided that has an attached, movable shield that can be moved between either one of two locked positions. The shield can be placed in one position in which it covers and protects the blade and in a second position where it forms a portion of the body for use of the knife.