Abstract: In a fiber optic receiver of the type comprising a photodetector, a preamplifier, a postamplifier and a voltage comparator for quantizing the output to a logic level signal, the improvement comprising symmetrical clamp means interposed between said postamplifier and said voltage comparator.

Abstract: In a repeater for a communication system a continuously running local oscillator (P) injects a pilot tone into the repeater input, ahead of all the non-linear functions. The repeater may include an input amplifier 1, a re-shaping amplifier 2 and an output amplifier 3. The pilot frequency is unique to the repeater and is sufficiently close to the clock frequency in a digital system or the carrier frequency in an analogue system to allow the pilot to pass through all the repeater filters. The pilot effects a small phase modulation of the carrier or clock. Measurement of the amount of phase modulation and also the pilot amplitude at the receiving terminal indicates degradation or failure of the system performance. The pilot frequency is used to identify the repeater.

Abstract: This ringing circuit detects the presence of the ringing signal on the subscriber line by means of a first circuit for detecting transition of the same direction in the ringing signal and of a second time measuring circuit for defining a validity window for the occurrence of a transition of desired direction and for providing a ringing control signal when the ringing signal is recognized. The ringing circuit is supplied by rectified AC ringing signals wherein a sufficient-voltage detection circuit is provided to authorized the operation of the ringing circuit.

Abstract: The invention concerns a method and a device for lifting and lowering of a load. The load is provided with a short lifting chain which in its turn is connected to a guiding wire. A lifting hook connected to a lifting device is arranged to be guided along the guiding wire to the lifting chain.When the guiding wire is slacked the lifting chain will engage a slot in the lifting hook and the load can be lifted up.

Abstract: Solid electrolytic capacitors are made in a batch process by etching a tantalum foil to form a number of rows of teeth, screen-printing tantalum powder ink onto the teeth, processing the sheet through sintering, anodizing and manganesing stages, sequentially encapsulating opposite edges of the rows of teeth in conductive epoxy and the "gap" with insulating epoxy and separating the individual capacitors from the rows.

Abstract: A device for transporting lubricant to the mechanical sealds in a submersible machine includes a funnel shaped guide means arranged on a rotating shaft in an oil room. Oil will be sucked in at the small end of the guide means and flow out at its big end thus obtaining a transport of oil.

Abstract: A diaphragm pump pumping arrangement includes two diaphragm pumps which are arranged and operate in tandem. Each of the diaphragm pumps includes a housing and a movable wall that includes a flexible diaphragm and subdivides the interior of the respective pump housing into a pumping chamber and an actuating chamber. An air distributing control arrangement interposed between and connected to the pump housings includes a spool valve movable in a bore of an aluminum casing of the control arrangement between two end positions in which it alternatingly achieves the admission of the compressed air into one, and discharge of the air from the other, actuating chamber.

Abstract: Height adjustment means for a cylindrical brush in a carpet sweeper with a U-shaped adjusting yoke which loads the cylindrical brush and is mounted in the housing by angled parts molded on the free ends of its members and is loaded at the summit part by a spring connected to an adjusting slide and riding up on ramp surfaces.

Abstract: A gallium arsenide logic circuit which forms part of a silicon/gallium arsenide logic interface, is provided with a negative supply voltage from a silicon logic gate whose output is held in its LOW condition. This obviates the need to provide separate power supplies to the two different semiconductor types.

Abstract: A cleaning brush for brushing clothing has a slip case that circumferentially surrounds a passage having a brush therein. The slip case has open ends, the brush being slid into and out of the slip case through either end. The slip case acts as a handle. Stops are provided at each of the open ends to prevent the brush from being separated from the slip case.

Abstract: A floor-sweeping machine consisting of a housing with a revolving brush which is mounted rotatably therein and is driven by means of running wheels and which is located between two dirt-collecting spaces, the two dirt-collecting spaces being formed by dirt-collecting containers which can be taken out of the housing upwards, and the dirt-collecting container having a resilient locking device which secures it in its operating position and which can be transferred by hand into its release position, and in which, to make it substantially easier to operate and especially to take out and empty the dirt-collecting containers, the two dirt-collecting containers 24, 25 are connected to one another and have a common top side 27 in which, approximately centrally, there is a part 35 which is to be grasped by the operator and is to be moved to a limited extent in the lifting-out direction and which, when moved in the lifting-out direction, transfers the resilient locking device 36 into the release position.

Abstract: A metallic material coating is applied to the external surface of a freshly drawn optical fiber while such surface is still pristine by passing the optical fiber through a body of liquid metal-organic material which forms a layer on the fiber, and by subsequently removing all non-metallic components from the layer of metal-organic material by volatilizing the same. The optical fiber with the layer metal-organic material is passed through a baking oven in which at least the layer is heated to a baking temperature at which organic materials present in the metal-organic material are volatilized and the remainder is baked to the fiber. Then, at least the layer is fired in a firing chamber at a higher temperature at which the metal-organic material is decomposed into its volatile non-metallic and non-volatile metallic components, the latter remaining in the layer and the former becoming volatile and leaving the layer.

Abstract: Floor-sweeping machine consisting of a housing with a revolving brush which is mounted rotatably therein and which can be driven by means of running wheels projecting from the under side of the housing, and in which, for the purpose of rapid assembly and removal, the revolving brush 14 is mounted rotatably by means of two bearing clasps 19 which engage on its ends and which each have a bearing receptacle 24 for the associated bearing end of the revolving brush 14, and the bearing clasps 19 are themselves retained by securely positioned clamping onto housing parts 23.

Abstract: A gate member for a gate valve provides improved sealing by providing for proper orientation of the gate member as it approaches its closed position and then providing improved sealing action as the gate member is closed further. A lip on the gate member overlaps a ledge on the valve body at the opening where the gate member enters the valve chamber. The lip is covered by a seal of resilient material having a cross-sectional shape that cooperates with the valve body to orient the gate member and that controls the compression of the seal between the lip and ledge as the gate member closes further. The shape of the gate member also helps to orient it while it is closing. A spine and a ridged cap of resilient material on the leading edge of the gate member cooperate to prevent blow-by of pressurized fluid when the gate member is closed. Pads integral with the seal contact the corners of the opening initially to orient the gate member and then to fill the corners when the gate member is closed further.

Abstract: Ceramic capacitors are made by printing green ceramic limps with a fugitive electrode material, stacking the printed limps and firing the stacked assembly to form the ceramic and remove the fugitive electrodes. This provides an array of laminar voids in the body. The ceramic is doped to form boundary layers, terminations are applied, and the voids are then filled, such as by vacuum impregnation, with an electrode metal.

Abstract: A dielectric composition which is particularly suitable for the manufacture of ceramic capacitors, comprises lead magnesium niobate with additions of one or more lead titanate, lead stannate, or lead zirconate. The composition can be fired at a temperature between 950.degree. and 1100.degree. C., which is lower than the conventional firing temperatures of 1200.degree. to 1400.degree. C. The lower firing temperature means that, in the case of multilayer ceramic capacitors, the internal electrodes can be made of cheaper materials than previously with resultant materials and process cost savings. Some of the compositions exhibit higher dielectric constants than conventional Z5U ceramics, which means that capacitor device size can also be reduced.

Abstract: A transverse mode stabilized injection laser with a planar active layer is provided with a transverse waveguiding effect by the presence of a rib of intermediate refractive index material protruding through a blocking layer overlying the active layer. Optionally the blocking layer may include high refractive index material to provide additional waveguiding effect and controlled attenuation of higher order transverse modes.

Abstract: A single channel duplex transmitter/receiver utilizing digital frequency shift keying (FSK) signals. An analogue-to-digital converter frequency modulates the output of a local oscillator whose output is coupled via a mixer/combiner/splitter network to an aerial. FSK signals received from the aerial in the receiver are mixed with the local oscillator output in network to provide quadrature signals which are low-pass filtered before being demodulated in a zero IF demodulator to give a digital output. To avoid unwanted sidetone the output of the A/D converter is fed through a delay to a digital network where it is subtracted from the corresponding signals fed back through the demodulator. The digital signals are then fed to a D/A converter.

Abstract: A demodulator of the type employed in a "zero-IF" system uses a local oscillator for providing guadrature output signals at the center frequency of an FM signal to be demodulated. The demodulator has first and second mixers for separately mixing the FM signal with the quadrature signals to provide a first and second output signal each in quadrature at the outputs of said mixers. These signals are low pass filtered. The demodulator includes third and fourth mixers with each mixer receiving at an input one of the low pass signals. At another input the mixers receive third and fourth signals. The third and fourth signals are derived from mixing a variable controlled oscillator (VCO) signal with the local oscillator guadrature signals. The outputs of the third and fourth mixers are applied to the inputs of a difference amplifiers, the output of which controls the frequency of the VCO in an automatic frequency control mode (AFC) to cause the output of the difference amplifier to provide demodulated signal.