Abstract: A refrigerated trailer 10 which is subject to having a restricted normal return air flow path back to the refrigeration unit 24 through the suction space 46 in communication with the return air inlet 34 of the unit, due to volume and arrangement of the load 42, is provided with secondary air return ducts 48 and 50 which are also in communication with the suction space 46 to ensure an adequate return air flow to the unit and thereby also assuring an adequate discharge of air to the rear 22 of the trailer.

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: The method of assembling lead-mounted electric components such as DIP 18 in automated fashion to a printed circuit board 14 is accomplished by building up a crimping tool (FIG. 7) comprising a base 28 with crimping anvils 12, 20, 22, 24, by selectively positioning and orienting the anvils on the base while the base is energized to provide a moderately low strength field, and the base is then energized to provide an adequately high strength magnetic field to retain the anvils properly during the subsequent steps of mounting the components to the board and crimping the leads to produce a particular type of board. After the requisite number of boards of a particular type are built, the anvils are removed to storage and the base is rebuilt to provide a different array of anvils for a different board.

Abstract: A combined refrigerant receiver, suction gas accumulator, and heat exchanger is provided and is particularly useful in connection with a transport refrigeration unit, and includes an internal concentrically disposed receiver 46 in the upper portion of an accumulator shell 40, the disposition providing an annular space 48 between the receiver and accumulator shell, in which is located a helically wound finned tube heat exchanger 56 which carries warm liquid refrigerant from the receiver to an outlet of the shell connected to an evaporator, with cold suction gas entering the shell at 52 and passing over the external fins 60 on the heat exchanger to exit the shell at 66.

Abstract: A transport refrigeration unit of the type which has a single or common refrigerant circuit, and a truck engine driven compressor 22 and a mutually, exclusively operable standby compressor 34 is provided with an arrangement of suction line fitting 46 with a pair of check valves 64 and 66 located physically above the fitting which receives the suction side refrigerant through line 48 from below the fitting and is provided with an inversely related pressure side fitting 54 with associated check valves 68 and 70 and the compressors are of substantially identical pumping capacity and oil capacity, all to the end of preventing an interchange of oil between the compressors during operation, and to migration of refrigerant and oil during periods of inoperation.

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: To reduce the probability of top freezing of a fresh cargo 12 in a trailer 10 served by a transport refrigeration unit 14, a control arrangement is provided including a sensor 18 controlling signals according to discharge air temperature fed to a first timer 20 which provides time periods according to the level of discharge air temperature, with shorter duration periods with lower discharge air temperatures, and when timer 20 times out effects actuation of relay 22 to reduce refrigerating capacity and start a duration timer 26 to maintain the reduced refrigeration capacity, with timer 26 functioning through a reset 28 to again start timer 20 when the duration timer has expired, and has caused the relay 22 to be operated to a position of normal refrigerating capacity.

Abstract: A hermetic refrigerant compressor having an electric motor and compressor assembly in a hermetic shell is cooled by oil which is first cooled in an external cooler 18 and is then delivered through the shell to the top of the motor rotor 24 where most of it is flung radially outwardly within the confined space provided by the cap 50 which channels the flow of most of the oil around the top of the stator 26 and then out to a multiplicity of holes 52 to flow down to the sump and provide further cooling of the motor and compressor. Part of the oil descends internally of the motor to the annular chamber 58 to provide oil cooling of the lower part of the motor, with this oil exiting through vent hole 62 also to the sump. Suction gas with entrained oil and liquid refrigerant therein is delivered to an oil separator 68 from which the suction gas passes by a confined path in pipe 66 to the suction plenum 64 and the separated oil drops from the separator to the sump.

Abstract: A hollow, airfoil shaped stator vane 10 is provided in its trailing edge portion with staggered rows of pin fins 20, 22 and 24 and with longitudinal ribs 26 which provide the required stiffness for the thin wall design of the vane, the ribs being provided with protuberances 36 in those locations where the turbulence inducing pin fins are displaced by the presence of the ribs.

Abstract: The tips 14 of any glow plugs 10 which are shorted are protected against enlargement by a separate protective device 28 in each series connection 26 to an individual glow plug opening in a fraction of a second in response to current through the device of a value corresponding to a short of the heating element in the tip.

Abstract: A one-piece, investment cast stator structure is provided including inner and outer shrouds 14 and 12 with a hollow airfoil-shaped vane therebetween and with areas 34, 36, 42 and 44 in the vicinity of the intersections of the shrouds with the airfoil vane walls being of reduced thickness relative to the remainder of the shrouds to provide improved properties of the material in these areas to better respond to thermal stresses imposed on the structure.

Abstract: A robotic manipulator wrist has one part 10 rotatable relative to the other part 12 of the wrist, and gear trains 16, 18, 20, operates to rotate the end effector shaft 14 when a brake 36 is applied to prevent relative movement between the two parts 10 and 12, and to rotate one part 10 relative to the other part 12 when a second brake 38 is applied to prevent relative movement between the end effector gear 18 and the intermediate gear 16.

Abstract: A split-ball type wrist and manipulator assembly (FIG. 6) includes a first ball portion 2, a second ball portion 4 rotatable independently and relative to the first ball portion, and end effector 52 rotatably carried by the second ball portion 4, the first ball portion 2 being controlled in its rotation by the hollow outer shaft 38, the second ball portion 4 being controlled in its rotation by rotation of an inner shaft 39 coupled to the second ball portion by the hollow, flexible coupling 45, and the end effector rotation being controlled by the innermost hollow shaft 42 rotation connected to the end effector by the inner flexible coupling 53, and with power line means 58 for controlling tool operation extending totally internally of the wrist and arm to the source of power.

Abstract: For a dual capacity refrigerant compressor of the type which has an eccentric cam rotatable on a crankpin between two opposite positions which changes the total eccentricity of the crankpin and cam so as to obtain two different stroke lengths, the rotation of the cam on the crankpin being effected by a reversal of motor operation, the cam moves through an angle of about 270.degree. around the crankpin so that a centrifugal force torque tending to hold the cam in place is available at least in the reduced stroke length position of the cam, and by providing lightening cavities and eccentric weightings, the center of mass 74 of the cam can be shifted to obtain the centrifugal torque in the proper direction at both the maximum and reduced stroke positions.

Abstract: The circuit arrangement includes a first voltage divider including a temperature sensitive resistance 18 and resistor R1 which feed an analog signal through line 30 to comparators CP1-4, which also receive reference voltages from a second voltage divider comprising R2-5. CP1 goes high with a falling temperature of 26.degree. F. or lower, CP2 goes high when the temperature falls below 22.degree. F. and CP3 goes high when the temperature falls below 18.degree. F. A first timer 20 is turned on when any of the comparators are turned on and counts pulses from an R-C circuit including R8-11 and C1. Whether R8 and 9 are in the oscillator circuit depends upon whether the bilateral switches S2 and S3 controlled by the comparator CP2 and CP3 have shunted them out. Accordingly, the counting is speeded up as the temperature drops.

Abstract: A hollow stator vane for a turbine is provided with separate forward and aft inserts 26 and 32 with the forward insert providing impingement cooling of the vane walls while the aft insert is closely fitted into the vane internal cavity to provide closely defined channel widths between the insert and facing walls of the vane, the aft insert also including means functioning during operation to ensure the maintenance of the closely defined channel widths, the coolant air admitted to the inserts functioning first for impingement cooling, then channel flow cooling along the aft insert, and then channel flow cooling of the trailing edge 18 through an exit slot.

Abstract: Shrink fit sleeves 30 interposed between the hub 21 and the shaft 10 of a large rotating apparatus adapted for operation in an environment subject to severe cyclical loading as occasioned by large thermal transients, are provided with the property of having greater axial shear flexibility than radial flexibility and/or greater axial flexibility than that of the shrunk on component 21.

Abstract: A multi-cylinder compressor 10 particularly useful in connection with northern climate heat pumps and in which different capacities are available in accordance with reversing motor 16 rotation is provided with an eccentric cam 38 on a crank pin 34 under a fraction of the connecting rods, and arranged for rotation upon the crank pin between opposite positions 180.degree. apart so that with cam rotation on the crank pin such that the crank throw is at its normal maximum value all pistons pump at full capacity, and with rotation of the crank shaft in the opposite direction the cam moves to a circumferential position on the crank pin such that the overall crank throw is zero. Pistons 24 whose connecting rods 30 ride on a crank pin 36 without a cam pump their normal rate with either crank rotational direction. Thus a small clearance volume is provided for any piston that moves when in either capacity mode of operation.

Abstract: The outdoor unit for an electric heat pump is provided with an upper portion 10 containing propeller fan means 14 for drawing air through the lower portion 12 containing refrigerant coil means 16 in the form of four discrete coils connected together in a subassembly forming a W shape, the unit being provided with four adjustable legs 64 which are retracted in shipment, and are adjusted on site to elevate the unit to a particular height suitable for the particular location in which the unit is installed.

Abstract: For a heat pump, the outdoor unit is provided with a coil and a refrigerant flow arrangement therefor which is such that in the heating mode of operation of the heat pump they operate in a thermosyphon fashion. The coil 32 has a feed portion 30 and an exit portion 34 leading to a separator drum 36 from which liquid refrigerant is returned through downcomer line 42 for recirculation to the feed portion. The coil is tilted upwardly from entry to exit by the angle alpha to enhance the clearance of the two phases of refrigerant from each other in the heating mode of operation. There is no thermosyphon function in the cooling mode of operation.