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 transport refrigeration system having a frame which supports a refrigerant compressor, a prime mover for the compressor, condenser and evaporator coils, and an air delivery assembly for moving air through the condenser and evaporator coils. The air delivery assembly includes a single shaft having first and second condenser blowers mounted adjacent the ends of the shaft, and an evaporator blower mounted on the shaft between the first and second condenser blowers. A drive arrangement for the air delivery assembly includes a jack shaft between the shaft of the air delivery assembly and the prime mover, with the prime mover being linked to drive the jack shaft, and with the jack shaft being linked to drive the shaft of the air delivery assembly.

Abstract: A refrigerant evaporator assembly suitable for remote mounting to a ceiling of a trailer compartment having a served space to be conditioned. The evaporator assembly is modular, including an evaporator module, a cover module, and an evaporator blower module. The evaporator and cover modules cooperatively define a tubular housing having first and second open ends, with the blower module removably closing the second open end. A grille covers the first open end. The evaporator module includes a base member which functions as a support base for the evaporator module during assembly of the module and as a drain pan in the refrigerant evaporator assembly. The cover module functions as a support base for the evaporator coil when the evaporator assembly is mounted to the ceiling of a trailer compartment.

Abstract: A transport refrigeration system suitable for narrow post highway trailers in which the refrigeration system intrudes into the trailer cargo space only to the extent necessary to direct trailer air into an evaporator. The evaporator is completely serviceable external to the trailer, with its inlet surface being substantially co-planar with the inside surface of the front wall of the trailer. An air delivery unit is manufactured as an integral assembly and mounted in a main support frame of the transport refrigeration system without requiring further adjustment. Mounting of the air delivery unit completes a plenum chamber for the evaporator, placing an axially narrow blower into an air flow path in which the blower draws trailer air through the evaporator and forces conditioned air back into the trailer. Mounting of the air delivery unit also places a fan into an air flow path in which outside air is directed upwardly through a condenser, and laterally through an engine radiator.

Abstract: The transport refrigeration unit (FIG. 5) includes a generally planar main frame 20, 22, 24 which supports a base frame 34 for carrying the compressor 54 and engine 56, and with an evaporator plenum 58 and a condenser plenum 60 in side-by-side, but spaced apart relation to provide a channel 62 therebetween. A heavy intermediate upper support member including wall 44 supports a bearing and support housing 68 which carries the shaft upon which is mounted, in cantilevered relation, both the evaporator blower 72 and the condenser blower 74. The plate fins 66 of the condenser are in planes parallel to the plane of the main frame with the air for the condenser entering the condenser plenum 60 from the side, rather than the front. With the arrangement as shown, all of the shafts carrying pulleys for the drive train to the blowers are parallel with each other.

Abstract: In a transport refrigeration unit, top and front shutters are controlled to open in sequence upon rising temperatures being sensed by temperature responsive control means located in a recirculation passage between the shutters.

Abstract: A method of compacting granular material with continuously vibrating a hollow pipe. The vibrating pipe is lowered into the material to be compacted with a crane type apparatus, maintained in a lowered position for a period of time and then withdrawn from the material. The vibration imparted to the material is increased by a number of annular rings located along the outer surface of the vibrating pipe.

Abstract: A method of compacting granular material with continuously vibrating a hollow pipe. The vibrating pipe is lowered into the material to be compacted with a crane type apparatus, maintained in a lowered position for a period of time and then withdrawn from the material. The vibration imparted to the material is increased by a number of annular rings located along the outer surface of the vibrating pipe.