Abstract: A method and apparatus for determining the sufficiency of refrigerant charge in an air conditioning system by the use of only two temperature measurements. The temperature of the liquid refrigerant leaving the condenser coil is sensed and the temperature of the condenser coil itself is sensed and the difference between these two measurements is calculated to provide an indication of the adequacy of refrigerant charge in the system. This process is refined by steps taken to eliminate measurements during transient operations and by filtering signals to eliminate undesirable noise. A permitted threshold of deviation is calculated by using probability theory.

Abstract: An elevator (20) includes a sill (38) that extends out from underneath an elevator car (30) to bridge an operating gap (26) between the car (30) and a landing (24). When an elevator door (34) is aligned with a landing door (36), the sill (38) extends outwardly from the car (30) until the sill (38) makes contact with a landing structure (40). A locking mechanism (52) securely locks the sill (38) to the landing structure (40). In one example, once proper sill alignment and locking engagement occurs, a door moving mechanism (50) is released and the elevator (34) and landing (36) doors open.

Abstract: A method and apparatus for determining the sufficiency of the refrigerant charge in an air conditioning system by use of temperature measurements. The temperature of the liquid refrigerant leaving the condenser coil and the outdoor temperature are sensed and representative electrical signals are generated. The electrical signals are converted to digital values that are than compared to predetermined optimal values to determine whether the system is properly charged with refrigerant. An appropriate LED is lighted to indicate that the system is undercharged, overcharged or properly charged. For non-TXV/EXV systems a third parameter i.e. the return air wet bulb temperature is also sensed and a representative digital value thereof is included in the comparison with the predetermined known values to determine if the charge is proper.

Abstract: The sufficiency of refrigerant charge in an air conditioning system is determined by a comparison of two sensed temperatures in the system, one being the liquid line temperature and the other being either the outdoor temperature or the condenser coil temperature. In one embodiment the two sensed temperatures are displayed on respective thermochromic strips which are so calibrated and juxtaposed as to provide a visual indication, by the relative positions of the two displayed sensed temperatures, as to whether the refrigerant charge is adequate. In another embodiment, the sensed liquid line temperature is displayed by way of a plurality of LEDs and the other temperature is displayed by way of a marker on a temperature scale. If the two displayed temperatures are aligned, then the refrigerant charge is optimized, and if they are not aligned, the system is undercharged or overcharged.

Abstract: An air conditioning system includes a plurality of sensors for sensing temperature and/or pressure conditions of the system which collectively indicate the actual refrigerant charge level in the system. This level is then compared with optimum level values that are stored in memory, and the difference between the two is used to indicate whether the system is properly charged. If not, the difference is applied to open a charge valve or a purge valve to automatically install additional refrigerant or to remove refrigerant so as to establish an optimum volume of refrigerant in the system.

Abstract: An elevator door moving arrangement includes a door mover (40) and an interlock device (42) supported near a lower edge (44) of cabin doors (26). The strategic position of the door mover (40) and the interlock device (42) minimizes the distance between the sill member (34, 78) and the operative components for moving the doors. In one example, the entire door mover assembly and the interlock are located beneath a sill member (34), which is beneath the bottom edge of the doors (26).

Abstract: A pulse free escalator system has two spaced apart pulse free turnaround sections and at least one pulse-free transition zone. A method of designing the turnaround sections and the at least one transition zone is described herein. The escalator system has a pair of guide tracks and a pair of linkage assemblies, each comprising a plurality of links joined together. Each linkage assembly has a plurality of rollers for supporting the linkage assembly which travel in a respective one of the guide tracks. Each guide track has two spaced apart turnaround portions with each turnaround portion defining a travel path for each roller having a linear entry section, a linear exit section, and a pulse-free section intermediate the two sections.

Abstract: The present invention relates to a pulse free escalator system having two spaced apart pulse free turnaround sections and at least one pulse-free transition zone and to a method of designing the turnaround sections and the at least one transition zone. The escalator system has a pair of guide tracks and a pair of linkage assemblies, each comprising a plurality of links joined together. Each linkage assembly has a plurality of rollers for supporting the linkage assembly which travel in a respective one of the guide tracks. Each guide track has two spaced apart turnaround portions with each turnaround portion defining a travel path for each roller having a linear entry section, a linear exit section, and a pulse-free section intermediate said two sections.