Abstract: A pair of thermoplastic coated, paramagnetic metal sheets (26 and 27) are moved from a position within a first bus loop half (28) to a position within a second loop half (29) while a pair of electrodes (31 and 32) are cyclically moved to engage and weld a line of spots along the sheets. Constant current pulses are cyclically applied to the welding electrode (32) and through the loop halves (28 and 29) to the welding electrode (31). The current divides in the loop halves in proportion to the positionment of the metal sheets in the respective loop halves so that eddy current and hysteresis losses are held to constant minimum values. Auxiliary heaters (43 and 44) act to heat the electrodes to melt and displace the thermoplastic coating along the line of engaged spots prior to the cyclic application of the weld pulses.

Abstract: A reactant deposition torch (10) has a plurality of concentric glass tubes (16, 18, 20, 24 and 26). Various gases pass through the tubes (18, 20, 24 and 26) while particle producing reactants pass through the inner tube (16). The concentricity of the tubes is accurately maintained by a plurality of precision machined splines located on the outer periphery of the inner and intermediate tubes (16, 18, 20 and 24). Additionally, the inner tube (16) is movable in the axial direction during the deposition process to controllably alter the amount of reactant to be deposited.

Abstract: An automatic pull tester and an acoustic emission system are herein combined to analyze the failure modes of lead frames bonded to integrated circuits. By using a discriminant analysis technique, a specific failure mode can be determined in real-time by first measuring up to five variables during the pulling operation. The five variables that may be measured comprise acoustic emission signals of a first amplitude (AE1), acoustic emission signals of a second amplitude (AE2), the time elapsed until failure (.DELTA.t), the number (n) of acoustic emission bursts above a first threshold, to the peak pulling force at failure (L.sub.max). Next, the variables measured are incorporated into a plurality of predetermined functions, each function corresponding to one failure mode (FM1 to FM5). The failure mode of the bond is determined by selecting the function having the highest value (FIG. 4).

Abstract: In the manufacture of electrical coils (10), particularly large transformer coils, an insulated wire (11) is wound on a rotatable winding arbor (12) so as to form a succession of turns of the insulated wire. Particularly when large gauge enamelled copper wire is wound, the insulation (14) has a tendency to crack or chip during the winding process, causing shorted turns and producing a defective coil. This application relates to systems for testing such a coil to detect a short as it is wound so as to permit interruption of the winding process and repair of the insulation fault on the spot. The test equipment includes a pair of test windings (41, 42) positioned at opposite ends of the winding arbor (12) and magnetically coupled by flux paths (50, 51) to each other and to the coil being wound so that an A.C. input signal (V.sub.1) applied to the first winding (41) induces an A.C. output signal (V.sub.

Abstract: A PBX system (20) receives a predetermined number of dialing digits from a central office which represents a subscriber station interconnected within the system. The system (20) adds a pseudo digit to the dialing digits to facilitate: (1) the use of a full compliment of dialing digits; and (2) the establishment of a switching connection with the subscriber station. The pseudo digit is then removed and the remaining dialing digits are translated into an equipment location for the subscriber station. Thereafter the switching connection is established with the subscriber station.

Abstract: A ladder foot (20) comprises (a) a bracket means (25) attachable at its upper end to a ladder rail (11) and including a stud (35) extending downward from such end, (b) a shoe (60) including a central sole plate (61) and a pair of upper plates (62, 63) extending from the sole plate to straddle opposite sides of the bracket means, and (c) a pin (75) fixedly secured with the upper plates and passing from one to the other through the bracket means adjacent the front side of the stud. The downward extent of the stud includes an upper range within which the stud fits between the pin and sole plate in such manner that the shoe is locked in toe-down position. Such extent also includes a lower range for which, if the pin is moved to register therein, the shoe is angularly adjustable from its toe-down position through a range of angular positions including a flat position.

Abstract: Methods and a system of this invention are used to determine whether a fault in a subscriber loop is located between a telephone central office and a reference point or between the reference point and subscriber terminal equipment without opening the loop. Included in the system are two current interrupter networks one of which is connected in series with the tip conductor and one in series with the ring conductor. If a fault exists between the central office and the reference point, the application of a test signal causes a constant current reading on a meter at a test center. On the other hand, if a fault is present in the loop beyond the reference point, an oscillatory current reading appears on the meter. The system also includes a recognizable impedance termination network which is connected between the tip and ring conductors of the subscriber loop to facilitate testing for opens in the tip and ring conductors.

Abstract: This invention involves optical fiber which supports essentially only a single guided mode, perhaps degenerate, at the transmission wavelength, usually between 0.6 and 1.7 microns. The index of refraction of the core material is graded in the radial direction so as to yield an optical fiber with very low total dispersion and therefore high bandwidth. Specific embodiments include, in addition to the low dispersion characteristic, improved field confinement, and therefore permit lower clad-to-core ratios then heretofore believed practical. Additional advantages which accrue as a result of the greater field confinement include lower cabling, microbending, and curvature-induced losses.

Abstract: A glass tube is formed having a mean cross-sectional tube wall area less than a preselected mean cross-sectional area. Additional glass differing in composition from that of the glass tube, but having an index of refraction substantially equal to that of the glass tube, is then fused onto a surface of the tube by vapor deposition, outside vapor-phase oxidation or outside vapor-phase axial deposition until the tube wall obtains the preselected mean cross-sectional area.

Abstract: Apparatus for supplying fluid to a rotary tube uncontaminated with ambient air comprises an end cap having an open ended bore in which an end portion of the tube may be rotatably positioned, a first conduit extending into the end cap through which fluid may be fed into the rotary tube, and a second conduit communicating with the end cap bore through which a purge fluid may be fed into and at least partially through the bore to the exterior of the end cap.

Abstract: An apparatus for substantially eliminating excessive edge growth in liquid phase epitaxy utilizing a substrate carrier 11 and a source material carrier 13 slidable over the substrate carrier 11 including a well 24 around a recess 14 in the substrate carrier 11 wherein the substrate 16 is held. The well 24 contains a material therein which reduces the heat loss from the edges of the substrate 16 held in the recess 14 thereby reducing excessive epitaxial growth around the edges of the substrate 16.

Abstract: The attachment of leadless chip carriers to printed wiring boards by means of soldering techniques must provide for a spacing between the chip carrier and the board. Such spacing is required for cleaning the area under the chip carrier, protecting the underlying circuitry, and accounting for stresses which may develop due to thermal mismatch between the chip carrier and the board, and to board flexure. Herein disclosed is a lead (15) for semiconductor chip carriers comprising an elongated body of high melting point electrically conductive material, e.g., solder material. Also disclosed is a method for casting such a solder lead, and a method for attaching a plurality of cast solder leads (38) to a leadless chip carrier (20).

Abstract: A feeder guide (10) comprises a pair of tube segments (11a, 11b) corresponding to the halves of a tube produced by its vertical bi-section through its axis. The segments are coupled through a hinge means (50) to be relatively movable between positions at which they are, respectively, spread apart and closed together to jointly form a tube assemblage having a central bore (13) with a front bellmouth (19), inward thereof, a throat (18) at which the bore has its minimum transverse dimension, and, rearward of the latter, a taper (25) divergent towards the rear of the bore and of greater transverse dimension throughout than such minimum dimension. The two segments are longitudinally stiffened by two pairs of web flanges (30a, 31a and 30b, 31b) respectively integral therewith and are releasably holdable in said closed position by fastening means (60).

Abstract: A test circuit (15 or 65), comprised of a plurality of parallel-connected circuit modules (15.sub.o-n or 65.sub.o-n), in response to both control signals from an associated commercially available automated test set (12), and output data from a test set-accessed read/write memory (14) under test, continuously senses for the presence of valid "one" or "zero" outputs on the data bit lines of the memory throughout a test set-established time window test period. When the memory output from a given data bit line, as applied to only an associated one of the circuit modules, is determined, as normally expected, to be continuously valid during each successive time window test period, a "pass" RESULT signal is generated by that circuit module and continuously applied to the test circuit (12) for flagging at any time between termination of the time window and the end of a given test set-established memory read cycle. Conversely, should the output on any memory data bit line be determined to be invalid (i.e.

Abstract: A cable which is suitable for use as a riser cable in buildings comprises a plurality of conductors each of which is covered with a composite insulation. The composite insulation comprises an inner layer of an expanded polyethylene material and an outer layer of a polyvinyl chloride material with the percent expansion of the inner layer and the thickness of the outer layer being such as to optimize several cable parameters. The resultant cable is one which has excellent fire-retardant properties such as, for example, an unusually low fuel content. Advantageously, this same cable lends itself to color coding for inside wiring and is capable of having a relatively high pair count density. All these parameters are optimized within the framework of specific transmission requirements.

Abstract: In the manufacture of integrated circuits, it is often necessary to prepare dielectrically-isolated single-crystal silicon regions to be used as substrates in which various circuit elements may be formed. These regions or substrates are formed by attaching a single-crystal silicon wafer (1) having a dielectrically-coated surface (2) to a second single-crystal silicon wafer (3) by means of an intermediate metallic layer (4) positioned therebetween. Using a heating process, e.g., a thermomigration process also referred to as temperature gradient zone-melting (TGZM) technique, the metallic layer (4) is removed through the second silicon wafer (3). This method substantially eliminates any bending or warpage of the dielectrically-isolated substrate (FIG. 1).

Abstract: Fabricating thin film RC networks (10) includes forming alpha tantalum capacitor base electrodes (14be) on a substrate (12), while simultaneously forming alpha tantalum anodization bus bars (14p and 14s) on the substrate. A portion of each base electrode (14be) then is anodized to form a capacitor dielectric (20) in a single anodizing step. A tantalum nitride resistor film (24) and electrically conductive films (26 and 28) then are deposited on the resultant assembly. Next, portions of the electrically conductive films are removed to define portions of capacitor counterelectrodes (22), to expose sections of the tantalum nitride resistor film (24) destined for use as resistors (24r). and to define conductor networks (30). Portions of the tantalum nitride resistor film (24) then are removed to define capacitor counterelectrode portions (24ce) and the resistors (24r), while simultaneously removing the anodization bus bars (14p and 14s). The resultant networks (10) then are thermally stabilized.

Abstract: A method of uniformly coating an optical waveguide fiber 10 comprises the steps of suspending an elongated glassy optical fiber preform 11 in an upright orientation from a preform holder that includes a collet 14 to which an x-y translator 15 is coupled, heating the preform, and drawing fiber from the bottom of the heated preform. The drawn fiber is passed through a tubular coating applicator 32 located beneath the preform, and the position of the fiber is sensed as it is being drawn. In response to sensed deviations in fiber position from along a preselected path that extends through the tubular coating applicator along the applicator axis, the preform is repositioned by horizontal movement of the preform holder so as to return the drawn fiber to the preselected path and thereby maintain its travel through the coating applicator substantially along the applicator axis.

Abstract: A method and apparatus for measuring the temperature of a moving elongated article is disclosed wherein radiant heat is sensed eminating from the focal axis or point of a parabolic or paraboloidal reflector beside which the article moves. An application of such is also disclosed wherein the temperature of a wire sensed in this manner is used in regulating an annealer.