Abstract: An improved electromagnetic clutch is provided with a permanent magnetic return mechanism. The clutch includes a rotor connected to a driven device, such as a refrigerant compressor, a flywheel connected to a driving device such as an internal combustion engine, and a contact plate assembly for transmitting torque between the flywheel and the rotor when moved from a disengagement to an engagement position by an electromagnet. Permanent magnet assemblies are used to bias the contact plate assembly into a non-engagement position when the electromagnet is deactuated. The use of permanent magnets in lieu of resilient mechanical components such as springs to bias the contact plate assembly into a return position substantially extends the service life of the clutch when it is used in conjunction with a prime mover such as a diesel engine, whose output is accompanied by momentary spikes of high torque.

Abstract: A refrigeration system, and method of operating same, with the refrigeration system having a refrigerant flow path which includes a heat exchanger having an inlet, an outlet, and a refrigerant flow path between the inlet and outlet. The refrigerant enters the inlet in a first predetermined phase and exits the outlet in a second predetermined phase. A first resistance device is disposed in heat exchange relation with the refrigerant in the flow path of the heat exchanger, adjacent to the inlet. A second resistance device is disposed in heat exchange relation with the refrigerant in the flow path of the heat exchanger, at a location between the inlet and outlet where the change in phase from the first phase to the second phase is desired. The first and second resistance devices are connected in a bridge circuit having bridge arms connected between input and output terminals, with a source of potential being connected to the input terminals.

Abstract: A transport refrigeration unit for mounting on the front face of a trailer 1 or the like is provided with an exterior section 2 construction and arrangement in which a relatively low center of gravity is obtained by providing a frame means 25 in the lower portion of the exterior section mounting an internal combustion engine 26 at a relatively low level with a refrigerant compressor 27 at a somewhat higher level, and an electric motor 28 below the compressor when such a motor constitutes a part of the power pack, these elements being arranged so that the driving belts and pulleys in the lower part of the section are in the center portion of the section to promote their accessibility, and a significant open area is provided above the power pack to promote access to those parts in the upper portion of the exterior section behind the condenser 9.

Abstract: A solar collector having a housing and a plurality of substantially parallel heat absorbing vanes mounted in the housing immediately beneath a radiation transparent upper wall in such a manner as to form a plurality of relatively narrow channels through which a heat exchange fluid is circulated. The width of the channels is preferably not greater than one-half of the depth of the channels and is preferably substantially less. The width of the channels may be as little as one-sixth of the depth of the channels. Provision is made for changing the angular disposition of the vanes and this may be done by heat sensitive means sensitive to the direction of the solar radiation. One form of the vane is L-shaped in cross section with a short leg of each L constituting the bottom wall of the channel and the long leg constituting a side wall of the channel.