Abstract: A method and apparatus for communicating a voice conversation over a single telephone channel using continuously variable level quadrature amplitude modulation establishes and maintains two totally independent communication paths, each near perfect in amplitude and phase with respect to frequency over a bandwidth suitable for communication of continuously variable amplitude pulses. These pulses may be representations of any suitable bandlimited analog signal. The method establishes almost flawless QAM channels (real, imaginary), then allows switching to continuously variable amplitude analog transmissions.

Abstract: Various methods have been proposed for measuring the viscosity of thermosetting polymers. It has been found that these method are generally inaccurate. A test which avoids the inaccuracies of previous techniques is proposed. In this test the heated thermosetting resin is forced at a known flow rate through a runner and through a capillary tube at the end of the runner. By measuring the pressure differential across the capillary a meaningful measure of viscosity is obtained.

Abstract: An apparatus (20) is provided for transferring articles (40--40) from a pickup position to a pickoff position and then to a dropoff position. The apparatus includes a pair of pickup arms (60--60) which are spaced apart to engage lugs (42--42) oppositely extending from an article to be transferred. As the transfer arms are caused to be moved rotatably, the article is transferred to the pickoff position whereat the lugs are adjacent to stepped end portions (88--88) of a pair of pickoff arms (80--80). Further movement of the transfer arms causes the article to engage surfaces (92--92) of the stepped free ends of the pickoff arms and to be supported by engagement of the lugs with surfaces (94--94) of the stepped end portions of the pickoff arms. Afterwards, the pickoff arms are turned to allow the article to descend until, at a predetermined position, the lugs of the article become engaged with a conveyor (100) and become disengaged from the pickoff arms.

Abstract: Disclosed is a means for testing drop wires in digital loop systems which employ optical fiber up to a distant terminal near the subscriber's premises. A test module is provided at the distant terminal to determine the presence or absence of faults on the wires to the customer premises. The results of the test are transmitted via an optical data link to the remote terminal where the results can be accessed by a loop tester at the central office.

Abstract: A laser marking apparatus provides markings of enhanced readability in an outer jacket of repetitively spaced sections along the length of a moving cable which is delivered from a supply source. The cable is advanced under tension and is wound onto a take-up spool. The outer jacket is of a specified color and has an outer surface. The laser marking apparatus includes a first guide roller, a laser marker, an applicator, a coarse brush roller with a first driving mechanism, a fine brush roller with a second driving mechanism and a second guide roller. The first and second guide rollers are disposed adjacent to the supply source before the laser marker and before the take-up spool after the fine brush roller, respectively, in order to guide the cable along a path of travel so that the outer jacket passes adjacent to the laser marker. The laser marker inscribes in the outer jacket markings opening to the outer surface thereof.

Abstract: This disclosure describes a double-sided transmission substrate formed with striplines and end-ports in juxtaposition on either side. The transmission substrate is sandwiched between two exterior dielectric substrates, each coated on one side with a metallic layer. The three substrates are laminated together. Through-holes are drilled into the lamination and its interior substrate, at known locations to intersect the said ports. The copper exteriors of each board are etched to identify two contact pad lands on each side. Plated-thru holes are created to connect to each of the ports.

Abstract: An audiographics conferencing arrangement for use in a business communication system allows the conferees to exchange displayed text and/or graphics stored locally in their respective data terminals. The conferees may change the displayed text and/or graphics and such changes are automatically distributed to the other data terminals so that all of the conferees view the same information. Moreover, a data terminal and its associated telephone station set may be included in an audiographics conference connection even though they are not directly served by the business communication system. In addition, one of the conferees may establish concurrent with the original audiographics conference connection a second audiographics conference connection with one or more other data terminals and transfer information obtained from one conference connection to the other conference connection.

Abstract: A laser (20) directs a laser beam at an optical fiber (12) and the resulting forward-scattered light is detected by a detector (21). The energy of the foward-scattered laser light is monotonically inversely proportional to the thickness of a carbon coating on the optical fiber. A computer (22) generates an electrical signal for controlling carbon coating thickness by driving a valve (24) to control the flow of acetylene from a source (14) used to coat the optical fiber in a coating chamber (13).

Abstract: In a packet network, each data packet that is transported through the network to a destination node is assigned one of 2**N priority levels based on the type of information contained in the data packet. A data packet containing system control information is assigned the highest priority level. A data packet containing, for example, user information, is assigned a lower priority level. In addition, each priority level is associated with a respective "watermark" threshold. When a data packet arrives at a network node, the node compares the packet's associated watermark threshold with the number of data words currently stored in a common memory. The node rejects the packet if the watermark threshold is found to be less than that number to reserve space in the memory for data packets of higher priority. Otherwise, the data packet is stored in the common memory.

Abstract: In a facility for conveying PWBs in a path of travel, two stop/clamp devices are magnetically clamped along the path to be spaced in its length and to be within the path width occupied by the traveling board. Each of the devices has stop and clamp elements shiftable as a unit between out positions at which they are disposed in the path and in positions at which they and the rest of their device do not interfere with the travel in the path of the boards. When in the out position, the leading device is adapted to stop the travel of such a board, and both devices are then selectively operable to grip and then release the stopped board. Sensors on the leading device are used to detect the presence of a board near to and at such device. A computer is responsive to such sensors and is used to produce a desired sequence of operations of such two devices and of other units.

Abstract: A single frequency lightwave system employs semiconductor, optical amplifiers arranged in tandem with suitable nose filtering and isolation between amplifier stages. Feedback control maintains overlap between the signal frequency and one of the passbands of the amplifiers. Either direct detection or coherent detection can be used. Also described is a receiver front end which includes such an amplifier between the incoming signal and a photodetector. Both transmission systems and switching systems are described.

Abstract: Radiation-induced effects discovered in layered structures of conductor and semiconductor materials are utilized in radiation-sensitive devices such as, e.g., highly linear as well as highly nonlinear position sensors. Such devices includes a structure of alternating layers of conductor and semiconductor materials, and electrical contacts are provided between which a radiation-induced voltage appears. Among suitable layer materials are silicon and titanium, and resulting devices are sensitive to electromagnetic as well as to particle radiation.

Abstract: A high capacity metropolitan area network (MAN) is described. Data traffic from users is connected to data concentrators at the edge of the network, and is transmitted over fiber optic data links to a hub where the data is switched. The hub includes a plurality of data switching modules, each having a control means, and each connected to a distributed control space division switch. Advantageously, the data switching modules, whose inputs are connected to the concentrators, perform all checking and routing functions, while the 1024.times.1024 maximum size space division switch, whose outputs are connected to the concentrators, provides a large fan-out distribution network for reaching many concentrators from each data switching module. The data switching modules chain groups of incoming packets destined for a common outlet of the space division switch so that only one connection in that switch is required for transmitting each group of chained packets from a data switching module to a concentrator.

Abstract: An optical preform is prepared first by depositing soot about a glass subate rod (22) to form a boule. Then the soot boule is sintered to consolidate the material and provide a preform from which optical fiber is drawn. The boule is relatively large so that the resulting preform is capable of providing more optical fiber than those used in the past. In order to be able to sinter successfully the enlarged boule, microwave energy from a furnace (60) is coupled to the glass rod so that the sintering proceeds from the rod radially outwardly thereby allowing gases readily to escape and rendering the process highly efficient.

Abstract: A polarization independent semiconductor amplifier is used in a double-pass configuration; that is, the output of the amplifier is passed through a 45.degree. Faraday rotator to a mirror and then through the rotator and the amplifier again. Polarization independent gain is thus achieved.

Abstract: A mobile hoist for loading and unloading heavy objects onto and from shelves in space limited quarters includes a hydraulic cylinder piston combination for elevating and lowering the objects utilizing a platform or a boom which may be attached to the piston. The piston moves up and down in response to a flow of hydraulic fluid to and from the hydraulic cylinder. The flow of the hydraulic fluid is controlled by a metering valve which is opened and closed by a cam driven arrangement designed to ensure that the fluid flow through the metering valve is nonlinear enabling soft, no shock stops regardless of the weight of the objects being elevated or lowered. The boom includes a sling lock mechanism which allows for placement of objects in locations with limited clearances.

Abstract: 36 We have discovered the III-V semiconductor layers with previously unattainably high effective hole concentrations can be produced by molecular growth processes (e.g. MBE) if an amphoteric dopant such as Be is used and if, during the growth of the highly doped III-V layer, the substrate is maintained at a temperature T.sub.g that is substantially lower than customarily used. For instance, a InGaAs layer with effective hole concentration 1.0.times.10.sup.20 cm.sup.-3 was grown at T.sub.g =450.degree. C., and a GaAs layer with effective hole concentration of 1.0.times.10.sup.20 cm.sup.-3 was grown at T.sub.g of 475.degree. C. The heavily doped III-V layers can be of device grade and can usefully be part of electronic devices such as high speed bipolar transistors.

Abstract: A folded bit line configured DRAM, with standard even and odd rows of memory cells, also includes spare even and odd rows of memory cells which can be substituted for standard rows found to have defective cells or interconnections. Each of the decoders associated with a standard row includes provision for being disconnected if found to be associated with a defective row. One common spare decoder is associated with one spare even and one spare odd row of memory cells. Each spare decoder is designed normally to be deselected for any address but to be able to assume the address of any disconnected standard row. Disconnection of a standard decoder and substitution of a spare decoder with the appropriate even or odd row are made possible by appropriate inclusion of fusible links which are selectively opened by laser irradiation. The use of one spare decoder with both an even and odd row serves to reduce the number of needed spare decoders and thus reduces overall chip size.

Abstract: A technique for providing high current carrying metal conductors for coupling to transistors or the like to increase the current carrying capacity of the transistor without substantial increase in size. The conductors are tapered along the axis of current flow with current being conducted to or from the tapered portion of the conductors, such that the current density therein is substantially constant.

Abstract: Differential amplifier having multiple stages, each stage having the gain thereof set by digital control. The gain of each stage is individually controlled, thereby allowing wide dynamic range and gain. Each stage has a differential pair with multiple sets of gain-setting resistors in the emitters of the pair. By selecting which resistor set, or combination of resistor sets, is used, the gain of the stage is controlled. The result is a 4 stage, 0-45 dB gain amplifier for RF or IF applications, with the gain adjustable in 3 dB increments.