Abstract: Means for coupling an electrooptical device, such as a semiconductor laser, to an optical fiber avoids heat-induced stresses that commonly result from joining methods employing welding, soldering, or catalytic adhesive compositions. In this invention, the electrooptical device and fiber are firmly mounted within separate elements, such as copper tubes, by means of potting compound or the like, and after close end-to-end supported alignment of the device and fiber elements to obtain optimum light coupling, the assemblage is immersed in an electrolytic plating solution. Plating current is then applied and maintained until a sufficiently strong layer of plating metal encompasses the tubular elements and thereby rigidly fixes the alignment of the device and fiber end at its optimum position. Since the plating operation proceeds in a substantially isothermic environment, there is no misaligning stress introduced which would otherwise degrade the coupling efficiency.

Abstract: A system for detecting an arcing fault in a telephone central office DC power distribution conductor repeatedly measures the current flow in the distribution line, as with an inductive coupling, and derives a Fourier transform analysis spectrum from such measurements. The power values at intervals across the frequency spectrum are compared with recorded threshold template values encompassing the spectrum typical of an arcing event and an alarm condition is established when such threshold levels are exceeded.

Abstract: Several ISDN telephone terminals in a passive bus configuration are enabled to be used to share a single voice communication in the familiar extension phone arrangement by means of a second bus connecting the analog sides of the terminal circuits. Once an incoming or outgoing voice call has been established at one of the number of ISDN terminals located on the premises, any others of such terminals may join the conversation by simply completing an off-hook connection by way of the analog bus. In conversion of premises to ISDN systems, the abandoned conventional telephone wiring may be employed as the analog bus. Conventional analog phones may also be utilized with ISDN voice terminals via the analog bus.

Abstract: A sychronous frequency encoding technique (SFET) provides method and apparatus for recovering the timing of an isochronous source node input service signal at the destination node of a synchronous ATM telecommunication network despite cell jitter which arises from the broadband multiplexing and switching delays in the network. A source node control clock is employed which is of greater frequency than that of the service signal and as a result a data under-flow condition occurs in the cell assembly process at a rate that is a function of the difference between such clock frequencies. Regular cell transmission is inhibited for a period at each under-flow occurrence and this pseudo-"stuffed cell" gap is signaled by setting a flag bit carried by an ensuing transmitted cell.

Abstract: The useful life of an electrolytic battery cell commonly employed in a series string as a backup power source is significantly extended by maintaining the polarization of the positive plates of such a cell at a predetermined level relative to a reference electrode of similar composition in contact with the cell electrolyte. While the cell is being supplied with the usual float charging voltage, a controller circuit senses any variance of polarization below the desired level and meters a minute input current to the positive plates with a resulting increase in the polarization over a substantial time period. The slow biasing of the polarization effects a passivation of the surface of the plates which deters the penetration of oxygen to the plate metal and prevents the deep destructive formation of expansive metal oxide.

Abstract: A process for controlling a telephone switching system provides a telephone customer access from any dual-tone multi-frequency (DTMF) telephone set to a memory-stored list of calls which the customer had previously been unable to answer at the customer's registered telephone station. A party receiving no answer when placing a call to the customer's station, whether due to a busy line or absence of the customer, is advised by a recorded message to enter, via the DTMF keyboard, the caller's phone number. The number received in the response is then entered on the customer's callback list, which may later be accessed by the customer from the customer's station, or from any DTMF set. Upon entering proper identification, the customer is advised of the number, and other identity, of any of the calling parties on the callback list. The customer may signal for the automatic placement of a return call to, or may delete or hold, any of such listed numbers.

Abstract: A framer-demultiplexer circuit provides means for reducing the high serial bit-stream rate of byte-interleaved low level signal frame structures proposed by the Synchronous Optical Network (SONET) signal hierarchy to speeds which can be processed with low-power low-cost CMOS VLSI technology, while establishing and maintaining basic byte integrity. In this circuitry the incoming high-rate serial bit stream is divided alternately between shift registers 43, 44 under the control of a single high-precision clock-division circuit to provide a multi-bit formatting that enables parallel delivery of stage bytes with the multifold reduction in transmission to a rate within the processing capabilities of CMOs devices.

Abstract: A method of conducting a public opinion poll by means of a telephone loop network comprises selecting such a network whose customers are representative of a universe of interest in the subject matter of the poll and soliciting by means of a mass communication medium, such as television, a non-billed manipulation of the telephone instruments of such customers during a prescribed time period in response to a polling question. During the polling period, while instruments of responding customers are placed in an off-hook condition, the normal line-scanning function in the network central office is disabled, thereby allowing electrical current to flow continuously in the network in proportion to the number of customer instruments in the off-hook state.

Abstract: Agricultural mulch sheeting which provides soil moisture retention and weed control during the growing season, yet is readily degradable when harrowed into the soil after harvest, comprises a creped natural kraft paper coated on both sides with a polyvinylidene chloride latex dispersion. The coating on one side of the sheet includes carbon black which provides the opacity to prevent weed growth while also yielding a reversible sheet which may be installed to absorb or reflect the sun's rays. The mulch may also include a sleeve of the same material sealed to the upper surface of the main sheet to form a conduit for irrigating water which seeps into the underlying soil through a row of puctures in the sheet.

Abstract: The adaptive and predictive capabilities of Adaptive Differential Pulse Code Modulation (ADPCM) equipment enable a telecommunication system to maintain acceptable signal/noise levels in voice transmission while utilizing a significantly lower encoding bit rate than that of conventional Pulse Code Modulation (PCM). ADPCM, however, has a deleterious effect on high-speed voiceband data transmission, yet due to its adaptive capabilities cannot readily be identified or evaluated by means of conventional ANSI/IEEE standard test signals and methods. The procedure of the present invention enables such identification and evaluation by imposing upon an ADPCM system a multiple-tone test signal which spans the voiceband and has amplitude characteristics similar to white noise. This signal thereby effectively overloads the adaptive and predictive capabilities of the system and causes the generation of a notably high level of quantizing noise.

Abstract: A telecommunications terminal block provides service wire terminations within cells that are electrically and physically isolated from other cells in the block, and from the environment, thereby effectively preventing corrosion and shorting by eliminating electrical bridging between tip and ring service wire circuits. Cell 21 in the dielectric terminal block body 10 contains a pair of spaced-apart contact surface members 32, 35 that are forced into compression engagement upon an inserted service wire end 26 by threaded advancement of a dielectric plug 13 situated within the cell. A conduit bore 12 in the block wall directs insertion of the stripped service wire 16 between the contact members prior to plug advancement, and a gasket member 38 extending across the annular space between the plug and the cell wall, with an optional cell-filling gel 47, ensures exclusion of the environment from the cell and isolation between tip and ring circuits.

Abstract: A surveying instrument and procedure are provided for the precise determination of elevation differences in the course of a surveying traverse. The instrument comprises an optical wedge 13 situated on the horizontal longitudinal line of sight axis 27 of the primary optical system between the objective lens 11 and a target under observation. The wedge is arranged for rotation about this axis and with such rotation angularly displaces the diverted line of sight 28 from the horizontal to the plane of the target. The degree of rotation required of the wedge to acquire the target 33 is measured by electro-optical angle encoder means 10, and the distance to the target by EDM means 24, 26. The difference in elevation is calculated trigonometrically by computer means utilizing as data the wedge diversion angle, the sine function of its rotation, the computed angular displacement of the line of sight, and the distance to the target.

Abstract: An improved mislevel sensing device having a balanced pair of capacitive pick-up circuits includes a pendulously-suspended common electrode assembly comprising a leaf spring member in the available flexing length of which is located a centrally-disposed hole which effectively reduces the cross-sectional dimensions of the suspension leaf member in that area, consequently restricting the beam-like flexure of the leaf to that area and away from sharp stress-imparting edges of leaf-clamping members of the device. The device further includes means for readily adjusting its attitude with respect to a primary reference axis of the host instrument, and means for providing protection of the functional capacitive couples from variable stray capacitive fields arising within the instrument, and from the intrusion of capacitance-effecting ambient moisture.

Abstract: Caprolactam, caprylolactam, and azacyclooctanone have been found to be equally effective as thiourea in stabilizing diazotype compositions and materials against pre-coupling, loss of shelf life, and dye image fading.

Abstract: A linear actuator mechanism which comprises skewed roller members arranged about a drive shaft and translates rotation of the drive shaft to linear displacement along the shaft includes a pair of body members having a ball joint between them which serves as a pivot about which adjustable spring compression constrains each of the three normal degrees of freedom in the body member pair to provide a kinematic union which eliminates indiscriminate displacement between the actuator mechanism and the drive shaft.

Abstract: An electrooptic light modulator is constructed from a pair of subassemblies each comprising a lithium tantalate crystal fixed between two rigid, conductive electrodes. Such subassemblies may be individually tested to ensure the selection of a pair of crystals which are matching in thermal and electrical responses. The modulator construction is completed by arranging the selected subassembly pair with crystal optic axes in orthogonal relationship in order to negate the effects of natural crystal birefringence, and fixing the subassemblies between a pair of rigid pole pieces which, together with the electrodes, serve as heat sinks to moderate the effect of thermal fluctuations, and further stabilize the assembly against mechanical and piezoelectric perturbations.

Abstract: A method of forming a color-proofing surprint includes the image-wise light exposing of an imaging sheet having a photoresist top layer, removing by the application of developer fluid the more soluble areas remaining after light exposure, thereby revealing image-defining areas of an underlying layer of pressure-sensitive adhesive, and applying a powdered colorant to such image-defining areas of adhesive. The residual areas of the photoresist layer may then be removed to reveal the non-imaged areas of the adhesive layer and the image-bearing adhesive surface of the sheet pressed into adhesive contact with a receiving surface. Removal of the original carrier film of the imaging sheet from the adhesive layer renders this layer accessible to receive, in image registration, the image-bearing adhesive layer, in different color, of a separate imaging sheet.

Abstract: Apparatus for safely transporting a sheet of photographic material through a development or other processing station comprises means for concurrently circulating processing liquid in the form of a plurality of streams both downward onto the sheet and upward from an underlying plate, the latter streams supporting the sheet and providing for the formation of a liquid layer between the plate and the sheet which facilitates the unrestricted passage of the sheet along the processing path. The downwardly projected streams are angled in the direction of sheet travel to provide further impetus to the movement of the sheet.

Abstract: A press apparatus comprising a pair of parallel rollers sequentially joins a plurality of pre-imaged adhesive layers in precise registration to form a composite color proof. Detent and coupling means maintain the respective rollers and mounted image sheets in predetermined registration until the rollers are brought together and rotated by separate drive means to effect lamination of the complementary imaged layers.