Abstract: A method for controlling first and second air/fuel ratio oscillations in first and second cylinder groups, respectively, of an internal combustion engine is provided. The method includes determining a first frequency of the first air/fuel ratio oscillations in the first cylinder group. The method further includes determining a second frequency of the second air/fuel ratio oscillations in the second cylinder group. Finally, the method includes adjusting the first frequency towards the second frequency responsive to a frequency difference between the first and second frequencies.

Abstract: A control system and method is provided for selecting one of first and second cylinder groups of an internal combustion engine when a frequency of air/fuel ratio oscillations in the selected cylinder group is to be adjusted. The method includes determining which of first and second frequencies of air/fuel ratio oscillations in the first and second cylinder groups, respectively, has a greater frequency. Further, the method includes selecting one of the first and second cylinder groups having the greater frequency of air/fuel ratio oscillations. The selection is made to reduce engine torque fluctuations when changing a frequency of air/fuel ratio oscillations in the selected cylinder group.

Abstract: A method and system for diagnosing catalyst operation in an internal combustion engine having a two-bank, three EGO sensor structure includes monitoring when the EGO sensors switch states between rich and lean and determining the ratio between a switch count of the post-catalyst EGO sensor signal and a switch count of a pre-catalyst EGO sensor signal over a selected time period. If the exhaust bank is a one-sensor bank having only a post-catalyst EGO sensor and not a pre-catalyst EGO sensor, the system uses the switch count from the pre-catalyst EGO sensor in the two-sensor bank to calculate the switch ratio, thereby allowing calculation of two switch ratios without two matched pairs of EGO sensors. The switch ratio indicates the efficiency of the catalyst and may be compared with later-generated ratios to monitor converter efficiency over time.

Abstract: A method and system for diagnosing catalyst operation in an internal combustion engine having a two-bank, three EGO sensor structure includes determining the ratio of the arc length between the post-catalyst EGO sensor signal and the arc length of a pre-catalyst EGO sensor signal over a selected time period. If the exhaust bank is a one-sensor bank having only a post-catalyst EGO sensor and no pre-catalyst EGO sensor, the system uses the arc length from the pre-catalyst EGO sensor in the two-sensor bank to calculate the arc length ratio, thereby allowing calculation of two arc length ratios without two matched pairs of EGO sensors. The ratio indicates the efficiency of the catalyst and may be compared with calibratable or experimentally-determined thresholds to monitor converter efficiency over time.

Abstract: A refrigerated, reach-in merchandiser having a product display area with a front opening defined by casing means having at least two mullion members, a reach-in door for closing the front opening and being hingedly mounted on one of the mullion members by door control means, said reach-in door having a transparent panel with a molded frame and at least two glass lites, door control means for hingedly mounting the door on said merchandiser, electric means for said merchandiser including lighting means on one of the mullion members for illuminating the display area, said electric means also including heating means for the glass lites of the transparent panel and including a key member for connecting said heating means to said merchandiser. A thermal door and a method for making the same are also disclosed.

Abstract: A method of forming a thermally insulated, transparent door for use on a reach-in merchandiser, in which said door has at least two glass lites, and which comprises providing a thermally and electrically insulating spacer member having an outer wall portion and an inner separator body portion, and forming angled notches in the separator body portion to define the respective corners of first and second glass lites; folding the spacer member at the angled notches around one of the glass lites with te body portion in surface contact with the inner glass lite surface and an edge flange of the outer wall portion in engagement with the adjacent marginal edge thereof, and bringing the free ends of the spacer member into juxtaposition and securing them together with locking means for holding the spacer member in assembled peripheral contact around the one glass lite; assembling another glass lite in surface contact with the body portion of the spacer member and in spaced relation with the one glass lite; and molding

Abstract: A method and system for adjusting a fuel injection amount in one of two groups of cylinders in an internal combustion engine using feedback signals generated by oxygen sensors coupled to both groups of cylinders. The claimed invention includes first and second groups of engine cylinders coupled to first and second exhaust banks respectively. The first exhaust bank includes a catalyst and at least a pre-catalyst EGO sensor for generating a first feedback signal. The second exhaust bank includes a catalyst and a post-catalyst EGO sensor for generating a second feedback signal. A controller calculates desired air/fuel ratio values for the first group of cylinders based on the first feedback signal. The controller also calculates desired air/fuel ratio values for the second group of cylinders based on the first feedback signal and the second feedback signal. The controller adjusts the level of liquid fuel injected into the groups of cylinders based on the calculated air/fuel ratio values.

Abstract: A method and system for diagnosing catalyst operation in an internal combustion engine having a two-bank, three EGO sensor structure includes determining the ratio of the arc length between the post-catalyst EGO sensor signal and the arc length of a pre-catalyst EGO sensor signal over a selected time period. If the exhaust bank is a one-sensor bank having only a post-catalyst EGO sensor and no pre-catalyst EGO sensor, the system uses the arc length from the pre-catalyst EGO sensor in the two-sensor bank to calculate the arc length ratio, thereby allowing calculation of two arc length ratios without two matched pairs of EGO sensors. The ratio indicates the efficiency of the catalyst and may be compared with calibratable or experimentally-determined thresholds to monitor converter efficiency over time.

Abstract: A method and system for controlling the air/fuel ratio in an internal combustion engine having first and second groups of cylinders coupled to first and second exhaust banks, respectively. The first exhaust bank includes a catalyst and at least a pre-catalyst oxygen sensor. The second exhaust bank includes a catalyst and no more than one post-catalyst oxygen sensor. The oxygen sensors monitor the oxygen content of the exhaust gases in their corresponding exhaust banks and provide feedback signals to a controller. The controller uses the feedback signal from the pre-catalyst oxygen sensor (in the first bank) to calculate desired A/F values in the first group of cylinders. The controller uses both the feedback signal from the pre-catalyst oxygen sensor (in the first bank) and the feedback signal from the post-catalyst oxygen sensor (in the second bank) to calculate desired A/F values for the second group of cylinders.

Abstract: A method and system for controlling the air/fuel ratio in an internal combustion engine having first and second groups of cylinders coupled to first and second exhaust banks, respectively. Each exhaust bank has a catalyst, a pre-catalyst oxygen sensor and a post-catalyst oxygen sensor, wherein the oxygen sensors monitor the air/fuel ratio in their respective exhaust banks and provide corresponding feedback signals to a controller. The controller uses the feedback signals to control the air/fuel ratio in the engine cylinders. When it is detected that one or the other of the pre-catalyst oxygen sensors has degraded, the controller calculates A/F values for the group of cylinders corresponding to the exhaust bank having a degraded EGO sensor based on feedback signals from the three still-functional oxygen sensors.

Abstract: A method and system for controlling the air/fuel ratio in an internal combustion engine having a first group of cylinders and a second group of cylinders. The first group of cylinders is coupled to a catalyst and at least one oxygen sensor, which provides a first feedback signal. The second group of cylinders is coupled to a catalyst and a post-catalyst oxygen sensor, which provides a second feedback signal. A controller uses the first and second feedback signals to calculate a short-term air/fuel bias value for the second group of cylinders. The controller also calculates a new long-term air/fuel bias value corresponding to the current engine speed and engine. The new long-term air/fuel bias value is based on a previously-calculated long-term air/fuel bias value calculated for the same engine load and speed. A total air/fuel bias value is calculated based on the short-term air/fuel bias value and the long-term air/fuel bias value. The new long-term air/fuel bias value is stored for future calculations.

Abstract: A refrigerated, reach-in merchandiser having a product display area with a front opening defined by casing means having at least two mullion members, a reach-in door for closing the front opening and being hingedly mounted on one of the mullion members by door control means, said reach-in door having a transparent panel with a molded frame and at least two glass lites, a door control for hingedly mounting the door on said merchandiser, an electric member for said merchandiser including a light on one of the mullion members for illuminating the display area, said electric member also including a heating element for the glass lites of the transparent panel and including a key member for connecting said heating element to said merchandiser.

Abstract: A fluid defrost system and method for defrosting the cooling coil of a product fixture normally cooled by circulating a cold secondary liquid coolant in a cooling loop refrigerated by a primary vapor compression system having compressor, condenser and evaporator means; the defrost system comprising a heat exchanger associated with the condenser means for warming secondary liquid coolant in a heating loop, and means for controlling the circulation of warm liquid coolant through the heat exchanger and cooling coil.

Abstract: An air cooling and control system for a refrigerated food merchandiser having an insulated cabinet with a product are having adjacent product zones, plural modular evaporator coil sections of substantially equal heat exchange potential and being of predetermined length and arranged in horizontal, spaced, end-to-end predetermined disposition and separate air moving means associated with each coil section and a corresponding product zone for circulating separate air flows through the coil sections and to the product area for cooling. The system further includes a first refrigerant metering valve for controlling liquid refrigerant flow on the high side of the evaporator sections, and a second refrigerant metering valve for controlling suction pressure and refrigerant vapor flow on the low side of the evaporator sections. An electronic control senses exit air temperatures downstream of the evaporator sections and operates the second metering valve in response thereto.

Abstract: A commercial refrigeration network including refrigeration system units constructed and arranged for placement in strategic proximity to corresponding product cooling zones within the shopping arena of a food store, each refrigeration unit having a condensing unit rack configured to accommodate the maximum refrigeration loads of its associated zone with an optimum floor space footprint in the shopping arena, and the condensing unit rack including a plurality of multiplexed compressors, condenser and associated high side and low side refrigerant delivery and suction conduits operatively connected to evaporators for cooling the corresponding zone, and the network also including another cooling source remote from said modular refrigeration units and constructed and arranged for circulating a fluid coolant in heat exchange relationship with the condenser to obtain optimum condensing and efficiency of said evaporators in cooling the corresponding zone.

Abstract: An air cooling and control system for a refrigerated food merchandiser having an insulated cabinet with a product area having adjacent product zones, plural modular evaporator coil sections of substantially equal heat exchange potential and being of predetermined length and arranged in horizontal, spaced, end-to-end predetermined disposition and separate air moving means associated with each coil section and a corresponding product zone for circulating separate air flows through the coil sections and to the product area for cooling. The system further includes a first refrigerant metering valve for controlling liquid refrigerant flow on the high side of the evaporator sections, and a second refrigerant metering valve for controlling suction pressure and refrigerant vapor flow on the low side of the evaporator sections. An electronic control senses exit air temperatures downstream of the evaporator sections and operates the second metering valve in response thereto.