Abstract: Apparatus for use in a heat exchange unit for securing a heat exchanger assembly to the remaining components of the unit. A pin which acts to secure a tubular member and a lateral support to either a fan assembly or a base pan is disclosed. This pin has an insertion portion having pin teeth which is inserted into a tube for securing the pin to the tube, a spacer portion for locating in a fixed relationship a lateral support relative to the heat exchange unit and a top portion for securing the pin to the component to which it is being fastened.

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 capacity control for a multi-cylinder refrigeration compressor includes a modulating valve disposed between a suction manifold and less than all of the cylinders of the refrigeration compressor. The modulating valve regulates the flow of refrigerant gas from the manifold to the cylinders in communication therewith, with the valve functioning to increase the flow of refrigerant gas to the cylinders as the load on the refrigeration unit increases and to decrease the flow of refrigerant as the load on the refrigeration unit decreases.

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: A hermetically sealed motor compressor unit has refrigerant gas at discharge pressure substantially surrounding the motor of the unit. The compressor includes at least two cylinders in which gas is compressed. A suction plenum for receiving gas at suction pressure surrounds each of the cylinders. Conduits, equal in number to the number of cylinders, are disposed externally of the compressor for delivering the gas into each of the plenums. One end of the conduit is connected to the plenum and the other end of each conduit is interconnected with the remaining conduits. The pressure pulsations developed in each conduit are controlled whereby the pressure in each plenum is at a maximum when the suction valve for a particular cylinder opens and is at a minimum when the piston is substantially at bottom dead center.

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: A motor-compressor unit comprising a compressor, a shell enclosing the compressor, and a suspension system resiliently suspending the compressor within the shell. According to a first aspect of the invention, the shell includes first and second sections joined together along a seam defining a vertical plane, and the suspension system includes a mounting plate and a resilient member. The mounting plate is supported by the shell; and the resilient member is supported by and spaced from the shell seam by the mounting plate, and extends between the mounting plate and the compressor to support the compressor resiliently within the shell. According to a second aspect of the invention, the shell and compressor define a plenum; and the suspension system includes a resilient member located in this plenum, extending between the shell and the compressor, and applying a resilient force to the compressor along a cylinder axis thereof to dampen movement of the compressor along the cylinder axis.

Abstract: A plurality of circumferentially spaced pockets are formed in the face of a stationary carbon ring. A rotating seal ring coacts with the pockets in the carbon ring to define a gas lift bearing to thereby reduce the pressure differential and leakage across the carbon ring. Alternatively the spaced pockets can be located in the rotating seal ring.

Abstract: A Belleville spring type of overspeed trip mechanism is made to rotate at the same speed as the shaft by preventing slippage between the spring and the other members of the trip mechanism. Slippage is prevented by forming grooves in the periphery of the interior portion of the spring and using pins which coact with the grooves to prevent rotation of the spring relative to the other members.

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 to prevent oil pump cavitation in a hermetically sealed vapor compression refrigeration system are disclosed. A hermetically sealed housing containing the refrigeration compressor transmission and oil supply reservoir is connected to the suction side of the compressor to equalize the pressure in the housing and the suction to the compressor is constructed with a restriction such as an orifice or a venturi to create a pressure drop or is of a size small enough to create a pressure drop when refrigerant flows through the line. The pressure drop is sensed by a pressure differential switch to anticipate sharp drops in pressure in the housing. The flow of refrigerant to the compressor is throttled in response to predetermined pressure drops to prevent a sharp drop in pressure within the transmission housing and thus prevent vigorous boiling of refrigerant from the oil reservoir.

Abstract: A method of regulating startup operation of a vapor compression refrigeration system to prevent oil pump cavitation during startup of the refrigeration system is disclosed. The method comprises monitoring the rate of decrease in evaporator pressure or temperature or monitoring compressor suction line pressure and then comparing this monitored rate to a rate of pressure or temperature decrease which is predetermined to prevent oil pump cavitation. If the monitored rate exceeds the predetermined rate control action is taken to adjust the capacity of the compressor to provide a desired rate of pressure drop which prevents oil pump cavitation. A microprocessor control system and a mechanical control system are disclosed for carrying out the disclosed method.

Abstract: An apparatus is disclosed for use in venting the products of combustion from a power combustion system such as an induced draft furnace. The apparatus includes a housing having three openings and a baffle. One opening in the housing receives the gaseous products of combustion from the power combustion system. A second opening in the housing is connected to a flue pipe which directs the products of combustion from the housing to an outlet vent. The third opening in the housing has a spillage damper or movable panel which can cover the third opening. The panel is pivotally connected to the outside of the housing above the third opening. When the pressure within the housing is less than the surrounding atmospheric pressure the panel is forced closed by this pressure. The panel is forced open and the products of combustion in the housing are vented to the surrounding atmosphere when a pressure greater than the surrounding atmospheric pressure is present within the housing.

Abstract: The present invention relates to a self-checking safety switch control circuit for a power combustion system. The circuit comprises a safety switch, a combustion blower relay, a thermal pilot switch, and a fuel supply system. The safety switch operates to detect flow through the combustion system. The safety switch either operates the pilot switch directly or operates the fuel supply system directly to shut down the system if no flow through the combustion system is detected. The circuit has a self-checking feature because combustion cannot be initiated in a subsequent cycle of the system if the safety switch remains in the proven condition from the previous combustion cycle.

Abstract: A method of trimming a resistance element is disclosed which comprises cutting transversely into one side of the element until the measured total resistance of the element increases by a fraction 1/N of a fixed percentage of a desired total resistance value. The fraction 1/N is approximately equal to the path length of the resistance element divided by the designed width of the transverse cut and the fixed percentage is equal to the percent deviation of the initial total resistance of the element from a nominal, desired resistance value. After the transverse cut is made, a longitudinal-type cut is made at a distance, equal to the length of the transverse cut, from the edge of the element having the transverse cut to isolate a portion of the element from the remainder of the element so that the isolated portion has the desired total resistance. This method is particularly suitable for use with computer controlled laser trimming systems used to mass produce resistance elements.

Abstract: A method of arc welding is disclosed. Specifically, a method of pulsed DC arc welding is disclosed wherein the pulse width of the current pulses are modulated to maintain a constant time averaged power flow to the work pieces being welded. This method of arc welding is especially useful with a type of pulsed DC arc welding wherein the ratio of peak current to maintenance current is maintained at a selected high value and the current is cycled in a time duration whereby oxides on the surface of the work pieces are dissipated as the weld is made. When used with this type of pulsed DC arc welding the present method is especially suited for fluxless welding of aluminum work pieces, such as thin wall aluminum tubing used in making heat exchangers for air conditioning systems.

Abstract: A flexible damped bearing arrangement for rotatably mounting a shaft wherein the shaft bearing is supported within a movable member suspended from a stationary frame by means of a series of resilient springs adapted to permit the member to move radially in reference to the shaft. A squeeze film cavity, provided with high pressure fluid, is established between the movable member and the stationary frame to dampen the bearing's response to the shaft. Seals are provided outside the damping cavity and are arranged to act perpendicular to the direction of movement of the member whereby the interaction of the seals with the squeeze film damping is substantially minimized.