Abstract: The linear D.C. motor is provided with parallel tiers of windings arranged along a linear path. A commutator is connected to these windings and extends along and parallel to the path. A conductor is provided in the form of two parallel strips to supply current through the commutator and through the windings. A plurality of pairs of magnets is arranged with the magnets in each pair being in serial magnetic relationship on opposite sides of the parallel tiers. A support of high magnetic permeability material supports the magnets to form a substantially closed magnetic circuit having a gap in which the tiers of windings are accomodated. Brushes on the support couple the conductor and commutator, and the support is displaceable along the linear path for selectively passing current through the windings, to establish electromagnetic fields in sequence along the magnetic path. Displacement of the support moves the magnets along the linear path in correspondence with the fields.

Abstract: Method and apparatus for monitoring the purity of a liquid in a container by passing a laser beam divided into two portions with the first portion passing through a pair of quartz windows with the liquid in a container therebetween, and the second portion being directed through the two windows and the liquid, the first portion being detected to detect the amount of solid particles in the liquid, and the second portion being detected to determine changes in refraction index to obtain a recording of the purity of the liquid.

Abstract: An ultrasonic sector scanner uses a transducer mounted within an ultrasonic transmitting medium with a rotating cam surface bearing against the transducer for inducing a rocking motion of the transducer between a pair of predetermined limit positions. The cam surface if rotatably driven by a Cardan joint mounted on a motor output shaft to produce an angular velocity of the transducer wherein the relationship between the angle of the transducer and the input shaft to the Cardan joint is a linear function. The position of the transducer is monitored by a code wheel connected to the motor drive to allow either a constant motor rotation or a selective angular positioning of the transducer.