Abstract: A multi-axis computer controlled machine tool for relief grinding of single and multiple start threaded hobs (46). The machine comprises an angular oriented spindle (65) that can be angularly (swivel) positioned thereby providing the flexibility to utilize both cup-shaped grinding wheels (55) and pencil-shaped grinding wheels (52) for grinding of hob and milling cutter relieved tooth geometry without exchanging grinding spindles assemblies or modifying the machine construction to accommodate two types of grinding methods or utilizing an additional machine axis for the spindle re-orientation.

Abstract: A self-locking safety pin comprising a tubular body which extends in circular fashion in a plane between opposed, spaced ends, the ends disposed to form a gap in the circular body, and an elongated curved tongue slidably mounted to extend, under bias, between a closed position extending across the gap from one end of the body into the other, and an open position in which the tongue is withdrawn into said one end of the body. The free end of the tongue is tapered to a fabric-piercing point. An actuator, by which the tongue may be moved to open position, extends from the tongue through an elongated slot on the body to the exterior surface of the body. An anchor is also positioned on the exterior surface of the body, spaced from the actuator. The actuator, anchor and slot are located on the side surface of the body, opposite from the gap.