Abstract: A refrigeration system comprises a display case having an exterior and an interior. A fan blows or draws air across an evaporator coil to cool the display case. The air is blowing over a viewing area to create an air curtain. At least one sensor obtains environmental data, which is fed to a control unit. The control unit communicates with the fan and adjusts the air curtain based on the sensed environmental data.

Abstract: A refrigerated cabinet (10) includes a cabinet base (20) defining an open top compartment having a refrigerated interior for housing a refrigerated product (50) and a canopy (30) disposed atop the refrigerated compartment. A transparent glass window in the front wall of the canopy (30) is extended downwardly to the product fill line within the refrigerated compartment thereby expanding the customer view area. The rear wall of the canopy (30) includes a transparent service door (40) and a framework (42). The service door (40) may be rotated independently of the framework (42) to an open position providing service access to the refrigerated compartment. The service door (40) and the framework (42) may also be rotated together as a unit to a second open position to provide access to the refrigerated compartment for cleaning and sanitizing. A lamp (80) for illuminating the cabinet interior is disposed externally of the canopy (30).

Abstract: A refrigerated cabinet (10) includes a cabinet base (20) defining an open top compartment having a refrigerated interior for housing a refrigerated product (50) and a canopy (30) disposed atop the refrigerated compartment. A transparent glass window in the front wall of the canopy (30) is extended downwardly to the product fill line within the refrigerated compartment thereby expanding the customer view area. The rear wall of the canopy (30) includes a transparent service door (40) and a framework (42). The service door (40) may be rotated independently of the framework (42) to an open position providing service access to the refrigerated compartment. The service door (40) the framework (42) may also be rotated together as a unit to a second open position to provide access to the refrigerated compartment for cleaning and sanitizing. A lamp (80) for illuminating the cabinet interior is disposed externally of the canopy (30).

Abstract: A plurality of frost shields (50) are removably positioned about the upper circumferential expanse of the walls of the liner (20) of a refrigerated cabinet (10). The frost shields (50) are magnetically mountable to the liner (20) to facilitate ease of installation and removal. Each frost shield (50) is a pliable panel fabricated in a layered construction with a relatively thin observe layer (52) of vinyl mounted on nominally thicker back layer of thermoplastic material (54) impregnated with magnetic material (60). Each frost shield (50) may be provided with a pair of handles (70) inserted in their respective slots (58) formed through the frost shield panel.

Abstract: A refrigeration system which controls subcooling by controlling the amount of refrigerant diverted from the condenser to the receiver based upon the difference in temperature between the phase change transition temperature of the refrigerant in the condenser and the liquid refrigerant temperature at the condenser output. Refrigerant is bled from the receiver to charge the system until the condenser pressure causes the difference between the phase change and liquid temperatures to exceed a predetermined value. A controller responds to this condition by simultaneously operating a bleed valve at the receiver inlet and a release valve at its outlet to draw refrigerant from the condenser into the receiver. As the condenser pressure drops, the difference between the phase change and liquid temperatures decreases toward the desired amount, and the cycle begins again.

Abstract: A compressor control system for a commercial refrigeration system includes a variable speed compressor and multiple fixed speed compressors. The control system calculates a variable which fluctuates according to the desired capacity of the system and is calculated as a function of the difference between a variable indicative of the refrigeration load on the system, such as compressor suction pressure, and a target value. A "PID" proportional-integral-differential (PID) controller is used in which terms have been added which fluctuate as a function of the square of the difference between the sensed variable and the target value and as a function of the second derivative of the control variable with respect to time. Fixed speed compressors are turned on or off and the speed of the variable speed compressor is adjusted to bring the actual refrigeration capacity of the system in line with the system refrigeration requirements.

Abstract: An edge seal gasket assembly for use in a multi-glazed window or door. The edge seal gasket assembly having a flange gasket fitted into the inset spacer between the separated panes of glass and embedded by a sealant compound on either side of the flange gasket. The flange gasket extending outward from between the panes to provide an edge seal gasket for sealing engagement with the sides of the insulated casing or another edge gasket.

Abstract: The invention is directed to a hinge assembly for pivotably interconnecting a frame and a glass door of a refrigerated display case. The hinge assembly is pivotable about a horizontal axis and includes a hinge movable between a first position and a second position. The hinge includes a spring biasing device for biasing the hinge to the first position or second position. A clamp is connected to the hinge and holds the glass door using only frictional force.

Abstract: A gas defrost apparatus for melting frost and ice from evaporators in commercial refrigeration systems using a pressure differential hold back valve to direct superheated refrigerant in a reversed direction into the evaporators and a gas return conduit for reintroducing the refrigerant into the main refrigerant distribution system between the compressors and condensers. Reintroducing the refrigerant on the high side of the condensers between the compressors and condensers prevents inefficiencies in the refrigeration system.

Abstract: In refrigeration system, a first solenoid operated valve in parallel disposition with an inlet pressure regulator for refrigerant to a receiver. The refrigeration system also includes a second solenoid operated valve disposed in a receiver bypass line. The first solenoid valve is a normally open valve and the second, bypass solenoid valve is a normally closed valve. A sensor is disposed on the outlet of the condenser of the refrigerant system for determining the condition of refrigerant exiting the condenser. A controller then operates the first solenoid valve and the second solenoid valve to direct flow to the receiver or to bypass the receiver if the refrigerant is subcooled.

Abstract: A refrigeration system for a display case including electronic means for controlling an expansion valve and a refrigerant compressor used in the system. The expansion valve is cycled between open and close positions to modulate refrigerant flow into an evaporator coil. A microprocessor controls the operation of the expansion valve in response to: (a) the relationship of the temperature of air that has passed over the evaporator coil to multiple upper and lower limits (b) time integrated temperature deviations beyond preselected limits (c) upward or downward trend of the differential in temperature in the refrigerant during its flow through the evaporator coil, and (d) extreme deviation of the temperature of air that has passed over the evaporator coil. Compressor cut-in and cut-out pressures are also adjusted by the control in response to these air and refrigerant temperatures.

Abstract: An improved evaporator unit in which a cooling tube core is placed between guide panels which permit a portion of the refrigerated air band to by-pass the front air opening of the core and to thereafter be forced into the core along a substantial longitudinal length of one or more side air openings. The flow of an auxilliary portion of the air stream into the side air opening permits the diffusion of frost build-up within the cooling tube core. A heater is provided for use during a defrost cycle in order to add heat directly into the cooling tube core. The improved evaporator is designed for use with reverse flow air defrost refrigerated container apparatus. Use of the evaporator permits improved refrigeration and defrost cycle operation.

Abstract: An improved oil return system for use with closed circuit mechanical refrigeration systems having multiple compressors. The oil return system is responsive to the flow of refrigeration gas to the individual compressors and enables an optimum flow of crank case oil to each of the multiple compressors. The system is based on the use of oil pick-up means for each of the suction lines connected between the suction manifold and each of the compressors. This pick-up means comprises a venturi tube which provides for the flow of oil through each of the suction lines responsive to the flow of refrigerant gas therethrough. The venturi tube has an outlet end positioned in a downstream orientation with respect to the flow of refrigerant gas through a surrounding suction drop sleeve.

Abstract: An automatically operated flexible barrier cover for the access openings of refrigerated display cabinets. The barrier cover limits the contact between the refrigerated air within the cabinet and the ambient air. The barrier cover can be moved over the access opening during non-customer use time periods when the retail food outlet is closed. The barrier cover can be arranged as a unitary assembly which can be manufactured and sold separately from the display cabinet as a retrofit device to effect energy savings. The flexible barrier cover can be stored in a reeled-up position or can be arranged as a folded flexible barrier which can be fanned out across the access opening. Various traction means are provided for moving the flexible barrier across the access opening.

Abstract: A refrigerated display case having an ambient air automatic defrost system and a method of operating such a case. The display case has an access opening in one wall for enabling products within the display section to be removed. The access opening can be either in the top of front wall of the display case. At least one air conduit extends in an approximately C-shaped formation around the display case. The air conduit has openings at both ends, with such openings being located on opposite sides of the access opening. Arranged within the air conduit is at least one reversible fan and a set of refrigeration coils. During a refrigeration cycle the fan circulates air through the air conduit in a first direction towards the refrigeration coils. When frost buildup within the display case has reached a certain level, the system is switched to a defrost cycle. During the defrost cycle, the fan circulates in the opposite direction through the air conduit and draws in ambient air from outside of the display case.

Abstract: An electric outlet assembly adapted for mounting in an opening in a wall to secure a current take-off means at various fixed positions relative to the opening. The take-off means is mounted in a cover member which is arranged to block the opening at all positions at which the current take-off means is secured. Positive or negative air pressure can be maintained within the wall. The wall can be an air conduit partition in a refrigerated display cabinet.

Abstract: A refrigerated display case having a display section within a cabinet and a movable door covering a front access opening to such display section. The door includes a frame member in which two glass members are mounted with an air space between the glass members. A refrigeration air conduit extends along the top, bottom and rear walls of the cabinet. The air conduit has an outlet opening and an inlet opening at opposing ends thereof with the openings being in alignment so that air leaving the outlet opening will be directed towards and received by the inlet opening thereby forming an air curtain across the front opening of the cabinet along the path inside the door. During a refrigeration cycle of operation of the display case, refrigerated air is circulated through the air conduit and a refrigeration mechanism arranged within the conduit so as to establish a refrigerated air band and a refrigerated air curtain across the front opening in the cabinet.

Abstract: A refrigeration system including a refrigeration control system for controlling the operation of the refrigeration system so as to insure that the temperature of the refrigerant discharged from the evaporator coil is above the saturation temperature. The refrigeration system includes at least one refrigerated display case having an evaporator within the primary air conduit and an expansion valve coupled to the inlet end of the evaporator coil. The control system includes: a pressure sensor arranged within the refrigerant discharge line, i.e. suction line to compressor, from the evaporator coil; a first temperature sensor arranged at the air discharge side of the evaporator coil for sensing the temperature (T.sub.1) of the air that has passed over the evaporator coil, a second temperature sensor arranged adjacent to the refrigerant discharge end of the evaporator coil for measuring the temperature (T.sub.

Abstract: A closed circuit refrigeration system includes a compressor, a remote condenser coupled to the output of the compressor, a receiver tank coupled downstream of the condenser means, and one or more evaporators coupled between the receiver and compressor return. A bypass conduit is coupled between the condenser output and receiver input at one end and between the receiver output and evaporator input at the other end; and a temperature controlled valve selectively controls the flow of refrigerant through the bypass conduit as a function of the temperature of refrigerant at the condenser output. A check valve in the condenser output conduit prevents backflow of refrigerant during periods of low condenser pressure. A method of operating a closed circuit refrigeration system is included in which a receiver tank bypass line is controlled responsive to the condition of the refrigerant in the condenser output.

Abstract: An open top refrigerated display case having an ambient air automatic defrost system and a method of operating such a case. A single air conduit extends in a U-shaped formation along opposing side walls and the bottom wall of the display case. The air conduit has openings at both ends in the location of the upper portions of the side walls. Arranged within the air conduit is at least one reversible fan and a set of refrigeration coils. During a refrigeration cycle the fan circulates air through the air conduit in a first direction towards the refrigeration coils. When frost buildup within the display case has reached a certain level, the system is switched to a defrost cycle. During the defrost cycle, the fan circulates the air in the opposite direction through the air conduit and draws in ambient air from outside of the display case. Since such ambient air is of a higher temperature than the normally refrigerated air, it serves to defrost the system.