Abstract: The invention concerns a refrigerant compressor with a cylinder block (1), a valve plate (4), a pipe connectable or connected with a suction muffler, a cover (2) covering the valve plate (4), a first sealing (3) between cover and valve plate and a second sealing (5) between valve plate and cylinder block. On assembling the refrigerant compressor it should be provided that the flow resistance of the suction gas is reduced as much as possible. For this purpose, each of the following pairs of members, cover. (2) and pipe (29), pipe (29) and valve plate (4) and valve plate (4) and cylinder block (1), has an alignment device for its members with at least two guiding elements, and that the members (2, 29, 4, 1) are assembled in a direction, which is substantially parallel to the guiding elements.

Abstract: A system for dispensing batches of fluid comprising a flowmeter (5), a pump or valve (6) for starting and stopping the flow and a controller (9) for controlling the pump or the valve. In order to reach a target batch size, the settling time at start of the flowmeter is compensated for as well as for the time it takes to stop the flow by generating a stop signal before the target batch size is reached. Further, to compensate for variations in the actual flow caused by variations in the feed pressure and the like, the compensation is made a function of the actually measured flow. A controller or a batch flow meter for use in dispensing batches is equipped with an interface for setting a compensating time constant and a correction unit for compensation of changes in the flow. The correction unit can consist of a differentiator an a summation circuit. Using digital techniques, the correction unit can be made as a lead filter.

Abstract: Customer premises equipment for a telecommunications DSL subscriber is adapted to provide a lifeline voice service under a fault condition, e.g. a power failure at the subscriber station. The arrangement incorporates a number of switchable local subscriber ports each providing access to a respective telephone instrument, and a router circuit whereby, under normal conditions, voice calls may be routed each to a respective loop port. Under a fault condition the router directs an incoming call to a selected port to provide the lifeline service. Further calls may be barred when such a lifeline call is in progress.

Abstract: A radio base station in a Fixed Wireless Access System broadcasts downlink data packets, each packet being transmitted on a single logical channel. A plurality of network subscribers in a sector may be members of a user group, each user group configured to receive and transmit packets transferred on a specific single logical channel only. Packets include a destination address which specifies a member of the user group. The packets include a token which specifies which user group member may transmit uplink data to the base station on the next frame. Logical channels are yielded for use by circuit switched traffic when required.

Abstract: Wave division multiplexers and demultiplexers utilizing fused fiber couplers and similar devices are expensive to implement. This is a barrier to deployment of optical networks particularly in the metro and access areas. The invention provides a cheaper design scheme to help overcome this problem. The invention provides an apparatus arranged to demultiplex a predetermined range and number of wavelengths comprising a plurality of devices each having at least one input port and two output ports, the output ports of each device having a periodic and complimentary series of minimum attenuation wavelength peaks, wherein the devices are arranged such that each demultiplexes a unique series of wavelengths, and wherein the apparatus comprises at least one device having a series of minimum attenuation wavelength peaks which do not correspond to the unique series of wavelengths the device is arranged to demultiplex.

Abstract: An optical switch comprising at least two segments, each segment having a respective input and a respective output, arranged such that in use if a first segment is removed, a second segment can operate as a pass-through device.

Abstract: Voice and data traffic are transported over a digital subscriber loop by multiplexing one or more plesiochronous packet data channels together with lower priority asynchronous traffic into a single composite data stream for transmission over the loop. The plesiochronous data packets each comprise a number of bytes together with a header element containing channel identification information and a packet length indicator. Each plesiochronous data packet is assigned a transmission time such that the desired nominal data rate for the plesiochronous channel is achieved when packets containing the preferred number of bytes are transmitted at the preferred time intervals.

Abstract: Interconnection of a multimedia terminal (110) of a narrowband, LAN-type network (10) to an exchange (118) and thence to an end-point (119) is orchestrated through an intermediate network (142), as shown in FIG. 5. A route (115) to the exchange (118) is initially established by a call handler (116) in responsive to a called party number of the end-point, before a connection supervisor (120), coupled to the call handler (116), sets up a control channel across the intermediate network (142). The control channel supports the communication of control messages between the multimedia terminal (110) and the end-point (119), which control messages are intercepted and interpreted by the connection supervisor (120). The connection supervisor (120) then establishes media paths through the intermediate network (142) dependent upon types of control message sent across the control channel, which media paths are used to transfer traffic components across the intermediate network.

Abstract: This invention relates to a phase and amplitude detector (160) required to identify small signal errors in a signal envelope having a large dynamic range, especially in the context of linearization of a power amplifier (122) arrangement employing a pre-distortion technique. A vector generator (300, 352, 372) responsive to a reference signal R (110) produces a frame of reference vectors R1-Rn (274-280) generated by a combination of the reference signal R (110) with first A (270) and second P (272) offset vectors that provide an amplitude and phase displacement of the reference signal R (110). A signal combiner (290-296, 360-366, 390-396) is arranged to generate difference vectors E1-En by combining the frame of reference vectors R1-Rn (274-280) and the feedback signal F (124, 150), with the difference vectors E1-En expressing the phase (p, 254) and the gain (a, 252) error terms relative to the reference signal R (110) and the first A (270) and second P (272) offset vectors.

Abstract: An apparatus and method for transferring a message from a calling party to an unavailable telephonically called party. The method comprises the steps of inititating a call to the called party over a communications channel, identifying that the called party is not available and instructing the calling entity to record the message at the calling entity and after recording to transmit the message to the called entity as a data message via a data channel for reception by the called entity. The system reduces the use of the voice/telephone communications networks by allowing a voice message to be transmitted through data channels, reducing the amount of voice traffic on the voice communication lines. The fact that the original voice message was actually stored with the calling entity after the telephone voice communication had been discontinued is transparent to both the calling party and the called party. Greetings for the called party can be stored at a messaging system of the calling entity.

Abstract: A rail restraining (1) and weld delivery device (100) uses a frame for supporting a welding head with a clamp (3) for restraining a first rail end and a second rail end and a base twist assembly (17) for aligning said first end and second end. An interconnected weld containment apparatus (290) pivotally connects to the clamp by use of a cam actuated linear pin (7). This arrangement is operable in an environment in which clearance between rails is about 7 to 11 inches and sufficiently compact that it may be operated from and carried in a truck based on a standard over the road truck.

Abstract: A method of manufacturing a pellistor comprises providing a porous catalyst layer (11) on a heater by electrodepositing material from a mixture containing the catalyst and a structure-directing agent in an amount sufficient to form an homogenous lyotropic liquid crystalline phase in the mixture.

Abstract: A dual band antenna is described which comprises a single band antenna surrounded by single band antenna elements. For example, the single band antenna may be a horn operating at a first frequency band and the single band antenna elements may be a flat plate array. In this case, the flat plate array contains an aperture through which the horn extends. The single band antenna and single band antenna elements are positioned such that a transmit and a receive antenna beam are created which have approximately equal phase centres and beamwidths. The single band antenna may also be an array of antenna elements, such as a flat plate array. Alternatively the single band antenna may be formed from dipole elements. As well as this the single band antenna elements may be dipole elements, flat-plate elements or any other suitable type of elements. The dual band antennas described may be used as feeds for reflector antennas or as antennas in their own right.

Abstract: A radio communication system (10) is disclosed which comprises a base station (12) for transmitting and receiving signals to and from one or more remote stations (16). The base station (12) is provided with at least one receive antenna (14) coupled to a base station receiver. The receive antenna (14) is provided with a directional pattern in a horizontal plane and a mechanism for steering the directional pattern azimuthly, until such time as a synchronization signal transmitted by a remote station located within the coverage area is received by the base station receiver. Upon detection of the synchronization signal, scanning of the receive antenna's pattern is stopped until such time as message information can be obtained from the remote station (16) and forwarded to a particular destination requested by the remote station. Upon receiving the information, the base station (12) will resume scanning of the antenna (14), and the information will be forwarded to its requested destination.

Abstract: An acoustic signalling device for containers destined for culinary use, in particular for boilers, is proposed, comprising a nozzle (11) able to convey externally to a container able to be closed (2) whereto the device is associated a steam jet formed inside the same container, a sounding body (12) fastened to a portion of the container able to be closed (2) and a movable element (13) positioned in the trajectory of the steam jet and able repeatedly to strike the sounding body (12) under the thrust of the same steam jet.

Abstract: A fibre optic coupling plate (24) has a sample viewing face for receiving light from a sample (12), an output window (18) for conveying sample originating (emitted) light to an imaging detector and an additional window through which excitation radiation can be projected. A primary light is provided through the plate made up of optical fibres which will convey light entering the viewing face, directly and with minimal loss, to the output window, and a secondary light path separate from the primary light path, by which excitation radiation entering the additional window is conveyed to the viewing face for irradiating the sample.

Abstract: A set of composite boss blocks for a rail car truck having equalizer arms and side frames uses a thermoset plastic resin system with a synthetic fiber reinforcement contained within the plastic matrix to handle severe loads under impact and vibration, in combination with set screw or pin extending through the mounting portion and well into the body of the boss block, a complementary wear pad also being usable.

Abstract: A hydrostatic steering arrangement with two control systems, each of which has a control unit with an inner and an outer rotary slide and a steering motor, one steering handwheel being common for both control units, and the control units being arranged in series in the axial direction of the rotary slides. On a failure of one control unit it is desired that the steering can be continued with a relatively high accuracy. For this purpose, a common inner rotary slide is provided for both control units.

Abstract: A flat-plate dual band array antenna is described which comprises two flat plate arrays of single band antenna elements, each of which operates in a different frequency band. The two flat plate arrays are positioned one above the other, with areas in the upper flat plate array being removed in order that the antenna elements in the lower flat plate array can radiate through the upper flat plate array. The geometric arrangement of the antenna elements is such that distribution networks for the antenna elements can be accommodated in the limited space available. Dual band flat-plate array feeds for a reflector antenna are also described. These use at least two flat-plate arrays that are positioned one above the other. Again regions in the upper flat-plate array are removed to allow the lower flat-plate to operate through the upper one.

Abstract: A hydraulic steering arrangement, having a steering value, which connects a steering motor with a pump, and which has a slide with two front sides, the slide being adjustable by means of a pressure fluid both through a hydraulic steering unit with a steering hand wheel and through an electro hydraulic steering unit with a control pressure generator. The two steering units have working connections and the front sides of the slide are connected with shuttle valves, each of which is connected with hydraulic steering unit on the one side and with the electro hydraulic steering unit on the other side. A valve arrangement connects the working connection of both steering units, which has the highest pressure, with one front side of the slide, and the working connection of both steering units, which has the lowest pressure, with the other front side of the slide.