Abstract: A precision head (10) for a machine tool includes a ram (12) axially movable along an axis A within an outer stationary ram support (14) of a polygonal shape. The outer stationary ram support (14) includes a pair of fixed bearing portions (16, 17) spaced from each other on one side (18) of the support (14) and a central bearing portion (20) on the other side (22) of the ram support (14) between the fixed bearing portions (16, 17). A pair of adjustable bearings (24, 25) bias the ram (12) against the pair of fixed bearing portions (16, 17). One of the adjustable bearing portions (24) is positioned on the central bearing portion (20) and the other adjustable bearing (25) is positioned in opposed relation to fixed bearing portion (16). The adjustable bearing portion (24) positions ram (12) with respect to the fixed bearing portions (16, 17).

Abstract: A windshield wiper blade made of a synthetic elastomeric material includes an elongated body having a longitudinal axis, a longitudinally extending central squeegee rib and a longitudinally extending scraping rib immediately adjacent to and on each side of the squeegee rib. All three of the ribs are integral with the body and project outwardly in the same direction from the body. The squeegee rib has a greater radial length than the scraping rib. Each of the scraping ribs has one 90 degree scraping edge and the squeegee rib has a pair of 90 degree squeegee edges. The one squeegee edge and the one scraping edge on the side facing the direction of movement of the blade engage the windshield. The scraping rib on the other side of the squeegee rib is out of contact with the windshield but engages the squeegee rib to effect lateral stiffness of the squeegee rib. A mounting rib is integral with the body and projects outwardly therefrom at a location essentially diametrically opposite the squeegee rib.

Abstract: An EDM electrode assembly including an electrode with a relative uniform, other-than-round shape, in cross-section along its entire length is supported within tubing by an epoxy bushing formed completely around an end portion of the electrode on one end of the tubing to slidably support the electrode. An EDM cartridge assembly constructed in accordance with the above further includes an outer tubing and a mechanism for driving the electrode through the bushing. A method for making the EDM electrode assembly as well as a method of refeeding the electrode.

Abstract: A modular EDM system including a compact servo slide assembly provides flexibility, accuracy and positional repeatability. The servo slide assembly includes a frame member provided with a precision dovetail for mounting on a column or bracket having a mating dovetail. The assembly also includes a slide member having a dovetail to receive and retain an electrode assembly thereon.

Abstract: Electrical discharge machining (EDM) apparatus includes an arc protection circuit which monitors the values of the ignition voltages applied across the gap between an electrode and a workpiece. A signal conditioning circuit includes a peak detector and averaging circuit conditions the voltage appearing across the gap and the arc protection circuit compares the value of the conditioned signal to the value of one of two reference voltage signals depending on whether the gap ignition voltages are increasing or decreasing. When the ignition voltages have decreased below the first reference level, the arc protection circuit provides a first control signal which causes a servo drive mechanism to increase the distance between the electrode and the workpiece. The first control signal also causes a pulse generator circuit to increase the off time between successive electrical discharges.