Abstract: A closed circuit vacuum apparatus having a nozzle housing which includes a cover and an exterior wall structure to form a housing interior. The housing interior is bisected by a baffle that is spaced apart from the wall structure of the nozzle housing to define an air-recirculation duct therebetween. The inner surface of the baffle defines the dimensions of an evacuation chamber. Preferably, the baffle follows the circumferential contour adjacent to the nozzle wall structure so that the air-recirculation duct completely surrounds the evacuation chamber. An evacuation port in the nozzle housing is in fluid communication with the evacuation chamber, and an exhaust port in the nozzle housing is in fluid communication with the air-recirculation duct. Particle laden air is extracted from the evacuation chamber for passage through the evacuation port to an inlet conduit.

Abstract: A spindle which may be connected to machine tools, taking power from a rotating power shaft of the machine for advancing and retracting a rotating tool at right angles to the power shaft of the machine. The spindle has a rearward uniform diameter screw which projects through a feed nut and into a hollow headstock. The feed nut has threads engaging the threads of the screw, together with an adjacent hollow section which seats an annular thrust bearing, as well as a rear collar of the headstock which constrains the headstock to move with the feed nut. Power is transferred to the headstock by means of a rotating quill, coaxial with the screw, but axially constrained within a housing. The quill is provided with a lengthwise keyway which is colinear with a similar, but much longer keyway in the headstock. The headstock is able to axially slide back and forth through the quill as the headstock is pushed and pulled by the feed nut moving on the screw.