Abstract: A bur grinding machine especially adapted to grind dental burs and including a turntable supporting a plurality of similar workheads having collets to support bur blanks; a plurality of grinding units mounted on a stationary base in circumferentially spaced locations around the periphery of said table and repsectively operable to perform different grinding operations in sequence upon the heads of bur blanks; means to index, rotate, and advance the collets of the workheads automatically at each grinding unit to form a plurality of teeth upon the bur blanks; means to index said table to advance the burs in the workheads to the next grinding unit; means to feed and accurately position bur blanks within the collets of the workheads; and means to control the cycle of the machine throughout.

Abstract: A foot control for a dental unit having a control unit for the delivery of power to operate dental equipment, and including a plunger to effect a range of speeds for the equipment, said control unit being operated by an actuating member which engages said plunger to depress it, and said actuating member being universally actuated by a pedal selected from a series thereof arranged in spaced relationship upon a base and extending radially from the base and capable of being moved either pivotally in a horizontal plane or depressed vertically downward to actuate said actuating member in one direction to depress the plunger of said control unit to a degree corresponding to the speed desired for the dental equipment.

Abstract: An operatory-type chair having a seat to which a back rest is pivotably connected for movement between upright and rearwardly extending positions by an electric motor interconnected to said back rest by a rotatable screw driven by said motor. Movement of the back rest is controlled by limit switches which stop the motor when either limit of movement is reached, the invention comprising an adjustable program switch included in said control system which operates to stop the motor when the back rest reaches a desired position intermediately of the opposite limits of movement thereof, as controlled by said limit switches.