Abstract: An acrylic glass plate for use as an opaque noise protection element in noise protection walls, the plate measuring a minimum of 2×2 m and having a minimum thickness of 8 mm wherein threads, strips, grids or networks consisting of a material which is incompatible with the acrylic glass are integrated into the acrylic glass for binding splinters in the event of a fracture of the plate, and the plate comprises between 40 and 80 wt. % of filling materials, in relation to its total weight (calculated without integrated threads, strips, grids or networks); and a method for producing such plates.

Abstract: The present invention relates to tanning aids, comprises a polymethyl methacrylate shaped body, where the transparency of the polymethyl methacrylate shaped body at 380 nm is at least 40%, and the polymethyl methacrylate shaped body comprises 0.005 to 0.

Abstract: The invention relates to tanning aids comprising a polymethylmethacrylate moulded body, which contains between 0.1 and 1.5 wt. % of a UV-stabiliser comprising a 2,2,6,6 tetraalkyl piperidyl group, said stabiliser having a transmission of at least 95% when dissolved in MMA with a concentration of 1 wt. % at 330 nm. Said polymethylmethacrylate moulded body contains between 0.005 and 0.1 wt % of a UV-absorber, which has a maximum transmission of 5% when dissolved in MMA with a concentration of 0.02 wt % at 320 nm and a transmission of at least 80% at 370 nm. The transparency of the polymethylmethacrylate moulded body is at least 40% at 380 nm.

Abstract: The invention relates to an acrylic glass plate for using as an opaque noise protection element in noise protection walls, said plate measuring a minimum of 2×2 m and having a minimum thickness of 8 mm, preferably more than 12 mm. Threads, strips, grids or networks consisting of a material which is incompatible with the acrylic glass are integrated into said acrylic glass for binding splinters in the event of a fracture of the plate, and the plate comprises between 40 and 80 wt. % of filling materials, in relation to its total weight (calculated without integrated threads, strips, grids or networks). Said filling materials are preferably extender materials consisting of talc and dolomite, optionally and preferably mixed with aluminium hydroxide. The invention also relates to a method for producing such plates.

Abstract: Self-reinforced, thermoplastically moldable sheets made from poly(meth)acrylate having at least two layers which differ in their filler content. The ratio between the elongation at break of the layer with higher filler content and the elongation at break of the layer with lower filler content is less than 1.5. The poly(meth)acrylate sheets can serve as a semifinished product for producing sanitary items, such as bathtubs, shower trays or washbasins, preferably by thermoforming, without the need for any other reinforcing layers sprayed on or otherwise applied after molding.

Abstract: A self-reinforcing semifinished product capable of thermoplastic shaping, composed of a single-layer sheet made from filled poly(meth)acrylate, where the semifinished sheet product contains a filler and has an upper side and a lower side, where the upper side is depleted with respect to fillers and the lower side is enriched with respect to fillers, in relation to the average filler content and a process for producing the semifinished products. The semifinished poly(meth)acrylate sheet products of the invention may be used in producing sanitary items, such as shower trays and washbasins, preferably by a high-performance shaping process, such as thermoforming.

Abstract: A transparent plastic pane of acrylic glass with internal plastic filaments, which largely hold together the fragments formed in the event of a break characterized in that the plastic filaments are at least partly sized. The internal filaments can be sized completely and/or partly, for example in portions. Hereby the matrix adhesion of the filaments can be adjusted to the effect that any fragments which may be formed in the event of break are largely held together by the filaments without permitting undesired detachment of the filaments during thermal stresses in the normal range of −20 to 120° C. The plastic panes are suitable in particular as a noise protection wall.

Abstract: The disclosure relates to a self-reinforcing semifinished product capable of thermoplastic shaping, composed of a single-layer sheet made from filled poly(meth)acrylate, where the semifinished sheet product has an average filler content Fm in per cent by weight, based on its total weight, an upper side U and a lower side L, characterized in that the upper side U of the semifinished sheet product has been depleted with respect to fillers and the lower side L has been enriched with respect to fillers, in each case in relation to Fm.

Abstract: The disclosure relates to self-reinforced, thermoplastically mouldable sheets made from poly(meth)acrylate. The sheets have at least two layers which differ in their filler content, where the filler content is the percentage proportion by weight of the reinforcing fillers based on the total weight (% by weight) of the respective layer. The ratio between the elongation at break of the layer with higher filler content and the elongation at break of the layer with lower filler content is less than 1.5, advantageously from 0.8 to 0.1, the elongation at break for the respective layer being determined to DIN EN ISO 527-2.

Abstract: A transparent plastic pane of acrylic glass with internal plastic filaments, which largely hold together the fragments formed in the event of a break, characterized in that the plastic filaments are at least partly sized.

Abstract: A plate utilizable in a noise protection wall of fragile acrylic glass comprising a plurality of side by side synthetic monofilament plastic threads for embedded in and running along the plate for splinter binding on breakage of the glass wherein, at least one thread has a maximum deviation of 1 mm or more from a theoretical straight line connecting the ends of said thread.

Abstract: A power amplifier comprises an input stage having a fully differential amplifier with differential inputs and differential outputs, and a high impedance closed loop common mode feedback control circuit deriving common mode feedback control signals from the differential outputs. The output stage of each differential output of the input stage comprises a class AB amplifier having source followers interfacing with the fully differential amplifier. A common mode output voltage control circuit maintains the common mode output voltage of the class AB amplifiers at a desired level. A quiescent current regulator comprises a circuit for mimicking the behavior of one of the source followers to derive a control signal for maintaining the quiescent current of the output transistors at a desired value.

Abstract: A circuit for maintaining hybrid cancellation of signals carried by a signal bus of a communication system, in response to variations in the number of hybrid circuits connected to the bus. One or more microprocessor control switches are utilized for selectively connecting one or more balancing load impedances to the bus in response to variations in the number of hybrid circuits connected thereto, such that a constant total load impedance is maintained on the bus. Also, circuitry is associated with each of the hybrid circuits for effecting hybrid cancellation of signals on the bus relative to the constant total load impedance. The circuit is of simple design and construction, occupying every little circuit board area and being of very low cost.

Abstract: A data interface for use in a communication system, comprised of a CPU module connected to a central controller of the communication system and a plurality of data terminals associated with respective subscriber sets of the communication system. The CPU module communicates with the central controller in response to user initiated requests at the respective data terminals, and executes telephone special features in association with the respective sets, such as dial-by-name, etc. The CPU module can also be connected to a personal computer, for interfacing the data terminals therewith on a time sharing basis. Furthermore, the CPU module functions as a data switch for implmenting electronic mail between the data terminals within the communication system. A communications module incorporating modems and Telex.TM. interfaces can be connected to the CPU module for establishing communication between the data terminals and one or more outside telephone lines via the communication system.

Abstract: A key telephone system comprised of a key service unit connected to a plurality of local sets via four-wire conductors for providing full duplex signal communication between the key service unit and sets. Signals are carried by a first pair of each of the conductors for unidirectional transmission of signals from each set to the key service unit, and the remaining pair of conductors carries signals transmitted by the key service unit for reception by one or more of the sets. Four-to-two wire signal conversion and line impedance balancing is effected by one or more trunk circuits of the key service unit in the event one or more of the local sets are connected via the key service unit for communication between the sets and the outside telephone lines.

Abstract: A system for expanding the number of signal ports accommodated by a base communication system having one or more switching circuits for interconnecting a plurality of local signal ports via a multiple line signal bus under control of a central controller. The expansion system is comprised of a plurality of expansion port circuits connected in parallel to the signal bus, for selectively interconnecting one or more respective remote signal ports to predetermined lines of the signal bus under control of the central controller. Each of the expansion port circuits preferably includes a selector/multiplexer circuit for selectively interconnecting the remote signal port with the predetermined line of the signal bus. According to a preferred embodiment of the invention, the communication system is a telephone system, such as a key telephone system or PABX, and the multiple line signal bus is comprised of a set of junctors.

Abstract: In a communication system, a modular expansion subsystem comprised of a plurality of general purpose slots disposed in the system cabinet, for receiving one or more co-operatively shaped interface modules connected to associated peripheral units, such as RS232C computer ports, answering machine interface circuits, local area network interface circuits, modems, etc. Additional slots are disposed in the cabinet for receiving one or more co-operatively shaped line or trunk interface modules connected to associated subscriber sets and outside telephone lines. A further slot is disposed in the cabinet for receiving a co-operatively shaped memory module in which an operating system program is stored. The various modules communicate with a central microprocessor of the communication system, which executes the stored operating system program, for identifying the various types of modules and the particular slots in which they are disposed.

Abstract: A key telephone system comprised of a key service unit connected to a plurality of local sets via four-wire conductors for providing full duplex signal communication between the key service unit and sets. Signals are carried by a first pair of each of the conductors for unidirectional transmission of signals from each set to the key service unit, and the remaining pair of conductors carries signals transmitted by the key service unit for reception by one or more of the sets. Four-to-two wire signal conversion and line impedance balancing is effected by one or more trunk circuits of the key service unit in the event one or more of the local sets are connected via the key service unit for communication between the sets and the outside telephone lines.

Abstract: A system for interconnecting a pair of communication systems comprising a pair of expansion switching matrices connected to bidirectional signal ports of the respective communication systems and interconnected via a plurality of signal paths, such as junctors. Control information is transmitted between central controllers of the pair of communication systems via a pair of serial data transmission circuits, such as universal asynchronous receiver/transmitters. Thus, predetermined ones of the signal ports of the separate communication systems may be interconnected via the expansion switching circuits independently of signal traffic within the respective communication systems. In addition, special features such as call ring back busy, may be implemented between signal ports of the respective communication systems as a result of control information being communicated via the serial data transmission circuits.

Abstract: A bidirectional communication system having separate unidirectional information signalling for connection to one or more signal ports, comprised of a first switching matrix for effecting bidirectional communication between one or more of the signal ports and a second separate switching matrix for establishing unidirectional communication from one or more information signal sources to a predetermined one or more of the signal ports. Preferably, the communication system is a telephone system and the signal ports are local subscriber sets and outside telephone lines. The information signal sources can be, for instance, supervisory tone generating circuits such as DTMF generators, RING BACK, DIAL TONE or BUSY/ERROR signal generators. Alternatively, the signal sources may be music on hold circuits or circuits for generating out of voice band data signals.