Abstract: A method of controlling refrigerant pressure during elevated ambient temperature conditions in a refrigeration unit having a refrigerant compressor driven by a prime mover, and controllable suction line modulation. The method includes the steps of detecting the actual load PML on the prime mover, sensing the ambient temperature AA, and providing a dynamic load limit DLL as a function of the ambient temperature AA. The actual load PML is compared with the dynamic load limit DLL, and the suction line modulation is changed as a function of the comparison step to cause the actual load PML to follow the changing dynamic load limit DLL. The invention also includes a method of preventing excessive on-off cycling of a refrigeration unit during low ambient temperature conditions, with the refrigeration unit operating in a cycling start-stop mode to control the temperature of a conditioned space to a selected set point temperature SP.

Abstract: A hand-operated hydraulic jack rotatably mounted on a trailer to assist in removably attaching the trailer to the hitching mechanism of a towing vehicle. The jack can be rotated to a vertical position and hydraulically actuated with a hand-operated pump to lift or lower the trailer tongue relative to the hitching mechanism. Once the trailer is attached to the hitching mechanism or is otherwise being adequately supported, the jack can be retracted by opening a thumbscrew valve on the hydraulic circuiting body to allow the hydraulic fluid to move through the return circuit back to the hydraulic fluid reservoir in the jack. The jacks's actuator is retracted by means of springs at the sides of the jack. With the tongue of the trailer supported and the jack retracted, the jack may then be rotated to its horizontal position to provide maximum ground clearance.

Abstract: A method of controlling a refrigeration system by determining an average air temperature by sensing and averaging evaporator return and discharge air temperatures, and developing an average error by using the average air temperature and a selected set point temperature. The average air temperature is then used to calculate a proportional error and an integral error, and the discharge air temperature is used to calculate a floor error. The proportional error, integral error and floor error are weighted by predetermined gain factors and then summed to provide an error signal which is used to modulate the capacity of the refrigeration system, with the control mode depending upon the location of the error signal relative to set point.

Abstract: A strain relief clamp suitable for protecting power cables, fuel lines, wire harnesses, and the like, which includes first and second identical metallic clamp members. Each of the first and second clamp members includes first and second ends and a right angle bend which forms first and second leg portions which respectively extend from the first and second ends to the bend. The first leg portions are corrugated to define curved recesses which cooperatively define elongated apertures when the first leg portions are fixed in assembled relation via aligned openings defined by the first leg portions. The second leg portions include openings adapted to fix the assembled first and second clamp portions to a housing associated with the items to be protected.

Abstract: A mounting clamp for mounting a power supply to the corner castings of a thermal freight container, having a locking mechanism which automatically locks the mounting clamp in selectable installation and locking positions. The locking mechanism includes a gravity biased release lever which is actuated when it is desired to change from one position to the other. When the release lever is actuated and a new operating position is reached, the release lever automatically locks the mounting clamp in the new position, without human intervention. The mounting clamp includes a base having first and second selectable positions for mounting the release lever, which positions respectively adapt the mounting clamp for right and left hand use.

Abstract: A fuel tank assembly which includes a fuel tank mounted below spaced I-beams of a refrigerated container chassis during a land transportation mode in which an engine driven generator provides electrical power for driving a refrigeration compressor. The fuel tank is mounted within about 0.5 inch of the lower flanges of the I-beams, to provide maximum road clearance, by a mounting arrangement which projects tank hangers above the level of the lower flanges of the I-beams, and by mounting brackets which extend downwardly from the tank hangers to rest upon the lower inner flange portions of the I-beams.

Abstract: A transport refrigeration unit for a transport container in which the refrigeration unit has side-by-side evaporator and condenser compartments 18 and 20 in the upper portion of the exterior frame, with a power compartment 24 extending across the entire width of the lower portion of the unit, the power compartment containing an internal combustion engine 26, a motor-alternator 28 and a refrigerant compressor 30 in in-line relationship, a radiator coil 62 condenser coil 64 being in inclined disposition in the condenser compartment and receiving air therethrough from condenser fan 66, the evaporator coil 72 being inclined in the evaporator compartment and in a disposition in which a portion of the coil projects out of the plane of the rear face of the frame, and a pair of double inlet centrifugal fans 74 are provided in the upper portion of the evaporator compartment to draw air from the upper part of the container and direct it downwardly through the coil 72 back into the container, and separate panels 36 and