Abstract: An apparatus for measuring the fat content of milk includes an optical guide having two light passageways for guiding light delivered from a light source. One of said light passageways is provided with a cuvette through which the fat of milk flows. Disposed adjacent to the cuvette is an optical correction device, which includes an open window and at least one optical correction window. The optical correction window comprises a transparent glass plate over which there are uniformly formed a number of scratches each having such a dimension as is capable of giving an optical result corresponding to the milk fat particles.

Abstract: A rotary actuator provides rotation of its rotor over predetermined angles. The rotor is a cylindrical housing in which are cylindrically curved permanently magnetized poles spaced apart at their ends and surrounding a fixed armature. The armature has magnetic arms angularly disposed with respect to each other which define fixed poles. Coils wound on the fixed poles generate magnetic fields when energized to drive the rotor. A holding coil may be provided to hold the rotor stationary when the holding coil is energized. The armature may have two, three or more fixed poles. The actuator can be operated in rotor latching or fail-safe return modes. Fixed stop members may be used to limit angular rotation of the rotor.

Abstract: Apparatus for purifying the air laden with paint particles for use in a paint spray booth, comprises a vertical duct having a mixing chamber at one end. The chamber has a horizontal wall formed with one or more straight or curved slots at which a spray or washing liquid and the air stream are directed to atomize the washing liquid. An upright guide structure in the mixing chamber defines a narrow passage or passages in which the impurities are removed from the air stream by the atomized liquid.

Abstract: An electrical system for measuring the speed of flow in a body of a fluid includes a current generator for energizing a coil and establishing a magnetic field in the body of the fluid. A current switching circuit connected between the current generator and the coil, cyclically reverses direction of current flow through the coil to reverse the magnetic field. The switching circuit includes energy storage capacitors for storing energy released by the coil during one half of each cycle and for returning the stored energy to the coil during the next half cycle. A control pulse generator supplies control pulses for cyclically controlling the reversal of current flow and the storage and release of energy in the capacitors.

Abstract: A helmet visor to be attached to the front of a crash helmet to protect the user's face and comprising a stiff support comprising a curved transparent plate covered by an antifriction layer and a movable film material extending across the user's field of sight. A supply roll of the movable film is rotationally mounted at one side edge portion of the support and a continuously or intermittently driven take-up roll is mounted at the other side edge portion of the support. When the film section within the user's field of sight has received sight restricting deposits the user actuates the driven take-up roll to draw the dirty film section out of the field of sight and introduce a fresh film section into the field of sight.