Abstract: A method for controlling the energization of a crankcase heater for use in a refrigeration circuit is disclosed. The crankcase heater is energized through normally closed relay contacts except when the compressor is operating and except for a delay period after compressor operation. A microprocessor control is utilized to calculate the delay period based on the length of the period of compressor operation and to control the energization of the crankcase heater.

Abstract: Apparatus and a method are disclosed for mounting a grille assembly to a sleeve designed for installation of an air conditioning unit. Rotatable mounting channels are secured to brackets of the grille assembly and may be manipulated from the interior of the sleeve to allow the grille assembly to be secured to the sleeve from the interior of the building. The sleeve includes a sleeve flange coacting with the grille flange and a channel support member having notches for receiving the rotatable mounting channels of the grille assembly for affixing the grille assembly to the sleeve.

Abstract: A wrapped fin heat exchanger is disclosed having variable spacing between adjacent loops forming the heat exchanger. Various embodiments are shown wherein the spacing between adjacent loops of single row and multi-row coils is varied to provide for equal heat transfer per loop of the heat exchanger and to effectively level out the air flow per loop. The various embodiments include varied spacing over a single row coil and multiple row coils having partial second rows and second rows with varied spacing while the first row has fixed spacing.

Abstract: A wrapped fin heat exchanger formed from a continuous length of tubing having a fin wrapped thereabout to provide an enhanced heat transfer surface is disclosed. A cylindrical core portion is formed from loops of tubing and a second cylindrical locking portion is mounted thereabout. The locking portion has bands which extend about and in engagement with the loops of the core portion to secure the heat exchanger in a predetermined configuration. By utilization of the locking portion and the core portion the unwinding of the heat exchanger is prevented and its structural integrity is maintained for subsequent manufacturing operations.

Abstract: An apparatus and a method for controlling the capacity of a reciprocating compressor by altering the effective stroke length of the working piston of the compressor is disclosed. The working piston of the compressor has a piston opening extending through the top surface thereof. A bypass piston having a cylindrical portion sized to block the piston opening and a reduced cross-sectional portion designed to allow gas to flow through the piston opening is provided. By adjusting the position of the bypass piston the effective stroke length of the working piston may be controlled to allow modulating compressor operation.

Abstract: A method and apparatus for expanding a tubular workpiece which includes mounting the workpiece in a lower die, filling the workpiece with fluid and engaging the upper portion of the workpiece with an upper die. The upper die is moved downwardly acting to physically compress the workpiece. The dies are additionally configured to form an internal pressure cavity such that further downward displacement of the upper die creates an internal pressure forcing the workpiece outwardly into the desired end configuration.

Abstract: Pressure variation absorbing apparatus is mounted adjacent to a moving fluid stream in the diffuser of a centrifugal compressor for absorbing both acoustic and aerodynamic pressure variations. The absorbing apparatus when mounted as a part of the diffuser wall of a centrifugal compressor not only reduces acoustic noise but also absorbs aerodynamic pressure variations increasing the efficency of the compressor and simultaneously reducing the rate of flow at which surge occurs thereby enlarging the operational flow range of the compressor. A method of absorbing pressure variations in a moving fluid stream is also disclosed.

Abstract: A heat exchange unit is disclosed having a combination coupling retainer and support. This combination coupling retainer and support acts to both secure a suction line coupling and a liquid line coupling connected to the appropriate headers of the heat exchanger and to provide structural support for the heat exchange unit. The coupling retainer and support includes a suction line opening for securing the suction line coupling therein and a liquid line slot in an arcuate configuration adapted to secure the liquid line coupling. This combination retainer and support is capable of being used in various units with heat exchangers mounted at differing angles, the suction line coupling serving as a pivot point and the liquid line coupling being positioned within the liquid line slot to secure the various components.

Abstract: A noise suppressing feeder tube for use in a refrigeration circuit is disclosed. A single unitary member having a middle portion flattened to reduce this cross-sectional diameter is disclosed for connecting a capillary tube to the evaporator of a small refrigeration circuit. By forming a unitary piece with a reduced cross-sectional area it has been found that refrigerant noise as is caused during the turbulent flow from the capillary tube to the evaporator may be suppressed.

Abstract: A method and apparatus for promoting effective heat transfer between refrigerant flowing through a heat exchanger and air flowing thereover and for providing a method of defrost of a portion of the heat exchanger wherein frost has accumulated. A headering arrangement is provided such that during defrost a portion of the heat exchanger is isolated and the fluid being supplied to the frosted portions of the coil is directed to the frosted portions to make the most effective use of the heat energy therein. Valve means are provided for regulating the flow of refrigerant to an intermediate header during defrost.

Abstract: Apparatus and method for the assembly of an air conditioning unit including a tube sheet isolator. An electrically and thermally insulative isolator is provided for securing an aluminum heat exchanger to a steel component of the unit. The tube sheet isolators further serve to allow various subassemblies of the air conditioning unit to be slidably engaged to secure the components relative to one another.

Abstract: An air conditioning economizer control method and apparatus for integrating the operation of the economizer with an air conditioning system is disclosed. An economizer position control arrangement is further disclosed incorporating a rotor locking circuit for maintaining the damper in position against a bias applied by mechanical means such as a spring. A multiple position indicator or multiple temperature sensor is utilized to modulate the position of the damper utilizing the motor for opening the damper, a spring for returning the damper and a rotor locking circuit for maintaining the damper in position. Multiple temperature sensors are also disclosed for making effective use of outdoor air when cooling through economizer operation is available. Staged cooling loads relative to outdoor ambient temperatures are utilized to select the appropriate mode of operation.

Abstract: A method and apparatus for slitting ribbon stock for use in making fins for a heat exchanger. A pair of slitter wheels are mounted to co-act on separate shafts. One of the shafts is driven by a motor and the other shaft is driven therefrom. Notched pulleys mounted on each shaft and a double sided belt connects the pulleys to maintain the slitter teeth and respective wheels in registration during rotation. A phase shifting device is further provided to allow for initial alignment of the slitter teeth relative to the pulleys.

Abstract: A method and apparatus for proving a demand for air conditioning or heating upon startup of an air conditioning unit before the unit is allowed to effect heat transfer. A separate thermal sensing unit is provided in the return air to prove a demand for cooling prior to the conventional thermostat of the unit being energized to operate the unit in the normal manner. This method and apparatus prevents energy waste and unnecessary cycling at startup and low load conditions.

Abstract: Apparatus and a method for inserting tube supports into a loose coil bundle are disclosed. A tube support insertion machine is disclosed wherein a series of spaced support arms are located within a cylindrical coil bundle. A drive is provided for forcing the support arms outwardly, each support arm having a tube support mounted thereto such that the tube supports are forced through the coil bundle securing each of the loops of the bundle in the appropriate location. A tube support for securing the coil bundle prior to the tube sheet insertion and a drive for co-ordinately driving the various support arms with equal force are further disclosed.

Abstract: A heat exchange unit for use with an air conditioning system having an enclosure defining an opening, a heat exchanger within the enclosure and a grille adapted mounted to the enclosure at the opening, the grille having segments extending between a solid center portion of the grille and an edge portion such that slots are created between adjacent segments. A fan motor is suspended from the center of the grille and a special louver segment is created extending from the fan motor to the edge portion. This louver segment includes inclined segments which coact with a wire guide for forming a wire securing cavity extending from the fan motor to the control section of the unit. This combination louver configuration and wire guide acts to secure the wire in a preselected position.

Abstract: A wire guide assembly for use in an air conditioning system having a heat exchange unit. A wire guide assembly acts to provide a secure cavity through which wires emanating from the control area and flowing to a separately located electrical component may pass. The wire guide assembly serves to protect the wires from engagement with either a rotating fan or a heat exchanger. The wire guide assembly includes a control area member having a T-shaped opening, a retainer and a cover slidably engaged to the retainer.

Abstract: Apparatus and a method for providing a combination of non-reverse and reverse defrost for a refrigeration circuit are disclosed. A three-way valve is provided for initially circulating hot gaseous refrigerant directly from the compressor to the heat exchanger requiring defrost. An intermediate header is provided as part of the internal circuiting of the outdoor heat exchanger, said intermediate header serving to direct hot gaseous refrigerant from the three-way valve into all of the circuits of the outdoor heat exchanger simultaneously to effect defrost thereof. If, after a predetermined time period, the first mode of defrost directing hot gaseous refrigerant directly to the outdoor heat exchanger fails to accomplish defrost then the three-way valve is returned to its original position and the system is operated in a second defrost mode with the reversing valve being changed such that the system operates in the cooling mode and the outdoor heat exchanger serves as a condenser until defrost is completed.

Abstract: Apparatus and method of assembly of a heat exchange unit wherein an annular orifice having a U-shaped cross section is assembled to a heat exchange assembly. The grille of the unit is supported on a support ledge of the fan orifice. An annular top cover having an L-shaped cross section may be engaged to the fan orifice to define a control area space therebetween. The top cover engages a top cover support ledge of the fan orifice and the grille engages a grille support ledge of the fan orifice to form a subassembly.

Abstract: An apparatus and method for operating an air conditioning unit incorporating both an economizer and a two speed fan are described. When the economizer is in operation the fan is typically operated at high speed regardless of refrigeration circuit operation to circulate sufficient outdoor air to the enclosure. When the economizer is closed, indicating the outdoor air is too warm to provide cooling to the enclosure, the fan is typically operated at low speed saving fan energy. An override control is provided for operating the fan at high speed regardless of the outdoor temperature should sufficient cooling demand be detected.