Abstract: A safety system for an elevating machine has a base part and an elevating part. The safety system includes sensor assemblies for sensing an electric or magnetic field, which are mounted on different parts of the elevating machine. A data processor is connected to receive sensor signals from the sensor assemblies. A memory stores data relating to numerous patterns of sensor signals associated with the interaction between the elevating machine and an electric or magnetic field. The data processor compares the received sensor signals with the stored data and identifies the positional relationship between the elevating machine and a source of the sensed field.

Abstract: A safety system for an elevating machine has a base part and an elevating part. The safety system includes sensor assemblies for sensing an electric or magnetic field, which are mounted on different parts of the elevating machine. A data processor is connected to receive sensor signals from the sensor assemblies. A memory stores data relating to numerous patterns of sensor signals associated with the interaction between the elevating machine and an electric or magnetic field. The data processor compares the received sensor signals with the stored data and identifies the positional relationship between the elevating machine and a source of the sensed field.

Abstract: A method and apparatus for generating, propagating, encoding, decoding, modulating and detecting acoustic signals in a well borehole that comprises a signal generator (10) located at a first location for generating an acoustic source signal; a medium for the propagation the acoustic source signal to a second location and the propagation of the reflections and partial reflections of acoustic signals as it propagates through the medium; an apparatus to remove a detectable amount of energy from propagated acoustic signals; a controllable signal modulator (11) for attenuating the transmitted acoustic source signal; and a receiver (12) for receiving the modulated acoustic signals reflected, partially reflected or both by at least one reflector respectively located at one or more other locations.

Abstract: A device comprising a receiver for receiving a broadcast; a processor for processing said broadcast to extract at least one data channel or service from said broadcast means for connecting said device to user equipment, said connecting means being arranged to establish a connection with said user equipment whereby said extracted data channel or service can be transferred securely to said user equipment.