Patents Assigned to American Telephone and Telegraph Company
  • Patent number: 4861278
    Abstract: The connector comprises a plastic holder which carries two wire leads and serves as a cap for the free end of a drop wire inserted thereunto. Two metal contacts received in slots in the holder are driven in by pliers action to pierce the insulation of the leads and drop wire and to each engage both the conductor of a respective lead and a respective conductor of the drop wire to thereby electrically connect these two conductors. Next, plastic covers for the contacts, hinged to and integral with the holder, are closed to become locked thereto. The connection is then adapted to serve as a plug for an aperture in a terminal box, and to be attached thereto by snap action, and to have its leads connected to terminals in the box.
    Type: Grant
    Filed: April 26, 1988
    Date of Patent: August 29, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Antoinette D. McBride, Arnold R. Smith
  • Patent number: 4861393
    Abstract: A molecular beam epitaxy method of growing Ge.sub.x Si.sub.1-x films on silicon substrate is described. Semiconductor heterostructures using Ge.sub.x Si.sub.1-x layers grown on either Ge or Si substrates are described.
    Type: Grant
    Filed: May 28, 1987
    Date of Patent: August 29, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: John C. Bean, Leonard C. Feldman, Anthony T. Fiory
  • Patent number: 4861976
    Abstract: Apparatus according to the invention comprises an optical, or opto-electronic device that comprises one or more "trapping" layers that can speed the decay of a non-equilibrium carrier distribution in an active region of the device, thereby improving device characterstics. In preferred embodiments the trapping layers are arranged so as to increase the likelihood of radiative recombination of carriers leading to erased heat sinking requirements.
    Type: Grant
    Filed: June 6, 1988
    Date of Patent: August 29, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Jack L. Jewell, Samuel L. McCall, Jr.
  • Patent number: 4861277
    Abstract: A card guide for guiding a circuit card towards a connector mounted on a backplane of electronic apparatus includes a first member which is mounted on the backplane and a second member releasably joined to the first member, the second member having a slot for accommodating an edge of the card for aligning and guiding it towards the connector.
    Type: Grant
    Filed: November 21, 1988
    Date of Patent: August 29, 1989
    Assignees: American Telephone and Telegraph Company, AT&T Information Systems, Inc.
    Inventor: Dale C. Bina
  • Patent number: 4859023
    Abstract: Optical fiber cables have an inner sheath extruded or otherwise applied to surround optical fibers. If the fibers are coupled to the sheath, substantial shrinkage of the sheath during manufacturing induces microbending losses in the optical fibers. The inventive technique involves choosing a sheath material having a low viscoelastic modulus, typically PVC, and the application of tension thereto during or after extrusion that prevents such shrinkage. This approach typically avoids the necessity of including longitudinal compressive strength members in the cable. A filled optical fiber cable having a flexible gel to prevent water entry advantageously uses the present technique.
    Type: Grant
    Filed: September 21, 1981
    Date of Patent: August 22, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Bernard R. Eichenbaum, Manuel R. Santana
  • Patent number: 4860296
    Abstract: The invention is a controlled laser having an optical resonator, a laser gain medium placed inside the optical resonator, the laser gain medium being capable of emitting light and of lasing with the light, a multiple layer heterostructure placed inside the optical resonator, and means for varying an optical absorption of the multiple layer heterostructure for the light in order to control an optical gain of the optical resonator, and thereby control lasing of the laser gain medium. Passive mode locking is achieved by the light emitted by the gain medium controlling the optical absorption of the multiple layer heterostructure. Active mode locking and modulation are achieved by controlling the optical absorption of the multiple layer heterostructure by applying an electric field to the multiple layer heterostructure.
    Type: Grant
    Filed: May 14, 1987
    Date of Patent: August 22, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Daniel S. Chemla, David A. B. Miller, Peter W. Smith
  • Patent number: 4859820
    Abstract: A key switch utilizing a buckling compression spring to move a switch actuator mechanism includes a cylindrical core of resilient material located within an opening formed by the coils of the compression spring to attenuate the acoustical energy generated by the buckling and unbuckling action of the spring.
    Type: Grant
    Filed: March 31, 1988
    Date of Patent: August 22, 1989
    Assignees: American Telephone and Telegraph Company, AT&T Information Systems Inc.
    Inventors: Casimer Gotfryd, Stephen L. Kay, Hartland P. Klotz, Robert M. Wentzel
  • Patent number: 4859876
    Abstract: An electrooptic or optical parametric device comprises a noncrystalline second order optically nonlinear element and means for providing an optical input to and an optical output from said element wherein said element comprises an organic molecule having second order optical susceptibility incorporated in a directionally oriented manner in an optically clear glassy polymer. When said device is employed in an electrooptic mode it includes means for applying an electric field and/or optical input to said element for altering an optical property thereof.
    Type: Grant
    Filed: June 19, 1987
    Date of Patent: August 22, 1989
    Assignees: AT&T Bell Laboratories American Telephone and Telegraph Company, AT&T Technologies, Inc.
    Inventors: Carl W. Dirk, Howard E. Katz, Salvatore J. Lalama, Kenneth D. Singer, John E. Sohn
  • Patent number: 4860163
    Abstract: In order to cool heat generating components mounted on circuit packs plugged into a backplane wiring board mounted in a compact cabinet, in which the backplane would normally prevent a stream of cooling gas entering the front of the cabinet from flowing evenly over the heat generating components, a flow control baffle is placed on each side of the backplane to direct cooling gas entering the cabinet to the rear of the circuit packs and then around the backplane to a plenum formed by the backplane and a rear surface of the cabinet where the gas is exhausted by a fan. The exhaust of the cooling gas by the fan causes the level of the cooling gas pressure in the plenum to decrease, thereby urging additional cooling gas to enter the cabinet through louvers formed in the front surface of the cabinet.
    Type: Grant
    Filed: August 5, 1988
    Date of Patent: August 22, 1989
    Assignees: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Alan Sarath
  • Patent number: 4860068
    Abstract: Single GaAs quantum well or single GaAs active layer or single reverse interface structures with Al.sub.x Ga.sub.1-x As barrier layers have improved qualities when one or more narrow bandgap GaAs getter-smoothing layers, which are thin, are grown and are incorporated in the barrier layer before and in close proximity to the active layer.
    Type: Grant
    Filed: January 27, 1988
    Date of Patent: August 22, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Arthur C. Gossard, Robert C. Miller, Pierre M. Petroff
  • Patent number: 4860064
    Abstract: A previously ignored property of a degenerate 2-dimensional gas of charge carriers in a quantum well (to be termed the quantum-capacitance effect) makes possible a novel class of transistors. In these devices the collector (a quantum well having high transverse conductance) is located between gate and emitter, with a barrier layer between emitter and collector, and a relatively thin barrier layer between collector and gate, and the chemical compositions and/or thicknesses of the various layers are chosen such that application of a voltage to the gate results, as a manifestation of the quantum-capacitance effect, in an induced charge in the emitter, whereby a current between emitter and collector can be controlled by means of a voltage applied to the gate. Transistors according to the invention potentially are very fast. Exemplarily the invention is embodied in a GaAs/AlGaAs heterostructure.
    Type: Grant
    Filed: October 21, 1987
    Date of Patent: August 22, 1989
    Assignee: American Telephone and Telegraph Company AT&T Bell Laboratories
    Inventor: Sergey Luryi
  • Patent number: 4860085
    Abstract: A high performance bipolar transistor structure is disclosed which exhibits an extremely low extrinsic base resistance by virtue of a silicide layer which is included in the base contact portion of the structure. The silicide layer is situated to be electrically in parallel with the conventional heavily-doped polysilicon base contact region, where a vertical polysilicon runner is used to provide a self-aligned electrical contact to the base. The parallel combination of the low resistivity (0.5-4 ohm/square) silicide with the polysilicon (sheet resistance of 10-100 ohm/square) results in a low extrinsic base resistance on the order of 0.5-4 ohm/square. The disclosed device also includes a submicron emitter size, defined by vertical oxide sidewalls above the base region, which further improves the high frequency performance of the device.
    Type: Grant
    Filed: August 24, 1988
    Date of Patent: August 22, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Anatoly Feygenson
  • Patent number: 4859827
    Abstract: Laser welding of an outer sleeve 14 to an inner fiber ferrule 12 is expedited by, first, machining a thinned region 18 in the outer diameter of the sleeve. After the ferrule has been inserted in the sleeve, the thinned region permits the laser to fuse through the sleeve and melt part of the ferrule, as is required for laser welding of ferrule for the sleeve. The thinned region is preferably made by using a rotary cutter to cut an axially extending slot in the outer sleeve, which permits a succession of laser welds 21 in the axial direction in the slot. In a preferred embodiment, thinned regions 18,19 are made on opposite sides of the outer sleeve, and laser welding is performed simultaneously on both sides of the sleeve so as to avoid distortions caused by thermal stress asymmetries.
    Type: Grant
    Filed: October 17, 1988
    Date of Patent: August 22, 1989
    Assignee: American Telephone and Telegraph Company
    Inventors: Richard J. Coyle, Jr., Jaroslav Mracek
  • Patent number: 4860358
    Abstract: An arrangement and a method for recognizing a speech pattern employs a quick initial processing based upon subpatterns of speech features from which time-sequence information has been removed is followed by more conventional processing of a plurality of the best candidates. The initial processing, or pre-selection, eliminates large numbers of unlikely candidates, the best candidates being retained by setting an empirically determined threshold for similarity, as measured by a suitable distance measurement. To facilitate retrieving the complete speech feature patterns including time-sequence information for the subsequent processing, the code books of the subpatterns also contain associated indices pointing to the corresponding complete patterns.
    Type: Grant
    Filed: December 18, 1987
    Date of Patent: August 22, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventor: Lawrence R. Rabiner
  • Patent number: 4860284
    Abstract: Apparatus and method for identifying the location of a lost token signal continuously transmitted on transmission paths interconnecting nodes of a network to sequentially enable the nodes to write data onto the network. The arrival of the token signal at each node is recorded in counter states of a token track counter corresponding with the node. The recorded binary counter states are compared upon the failure of the token signal to arrive at a node to detect mismatches and transitions occurring between adjacent nodes counter states identifying the network location of the lost token signal.
    Type: Grant
    Filed: April 20, 1988
    Date of Patent: August 22, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: David B. Brown, Richard E. Wallace
  • Patent number: 4856866
    Abstract: Disclosed are aligned plug optical fiber connectors that can accommodate larger differences in plug diameter and/or a wider range of plug diameters than is possible in prior art connectors, resulting inter alia in increased economy. The first of these advantages is attained through the use of bilaterally decoupled plug alignment means, i.e., means in which radial deformation of one half of the alignment means does not result in analogous deformation of the other half. A simple example of bilaterally decoupled alignment means is an alignment sleeve with a centrally located lateral slit. The second of the above advantages is attained through use of limited contact bilaterally decoupled alignment means, i.e., bilaterally decoupled alignment means shaped such that only a limited portion of the plug surface is in contact with the alignment means. A simple example of such alignment means is a transversely split alignment sleeve whose bore has roughly ellipsoidal cross-section.
    Type: Grant
    Filed: August 15, 1988
    Date of Patent: August 15, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Bell Laboratories
    Inventors: Lucius J. Freeman, Paul F. Gagen
  • Patent number: 4858168
    Abstract: A 32-bit adder utilizes an optimal partitioning scheme for improving the 32-bit carry look-ahead. Instead of relying on the powers-of-four partitioning scheme used in prior art adders, the inventive technique uses "double generate" and "double propagate" terms. These represent the generate and propagate functions for two bits. In addition, "double group geneate" and "double group propagate" terms are produced, which represent the generate and propagate terms for a 8-bit groups. In this manner, a partition of 1-bit/8-bit is obtained, rather than the prior art 1-bit/4-bit/16-bit. The critical path is typically shortened from 7 logic levels to 5 logic levels, resulting in faster operation. The double functions are advantageously implemented using logic circuitry having two (or more) outputs per gate.
    Type: Grant
    Filed: February 16, 1988
    Date of Patent: August 15, 1989
    Assignee: American Telephone and Telegraph Company
    Inventor: InSeok S. Hwang
  • Patent number: 4855996
    Abstract: Modems, data service units, application modules and other data communication devices, installed in a common equipment cabinet, are interconnected by way of a time division multiplexed bus. Time slots assigned to the various devices recur at a number of regularly-spaced access periods across each time division multiplex frame. The rate at which the access periods occur and the total number of access periods that make up each frame are chosen in such a way as to accommodate a mix of devices having respective bus access rates wherein there is at least one pair of rates for which neither rate of the pair is a whole number multiple of the other. The process of allocating access periods to the time slots is carried out using a known lemma to identify linear Diophantine equation solutions.
    Type: Grant
    Filed: August 3, 1988
    Date of Patent: August 8, 1989
    Assignees: American Telephone and Telegraph Company, AT&T Information Systems Inc.
    Inventor: William Douskalis
  • Patent number: 4856091
    Abstract: In a processing system (FIG. 1), peripheral boards (101-103) interconnected by a stack bus with a system board (100) each have an optical emitter (163) mounted on one face and an optical detector (162) mounted on the other face. The system board has an optical emitter mounted thereon. Emitters and detectors are arranged in a daisy-chain fashion: the emitter of one board faces the detector of the next board. To assign I.D.s (e.g. addresses) to boards, the system board turns on its emitter and transmits on the bus an I.D. The adjacent board's detector is illuminated and causes the board to latch the I.D. The system board turns off its emitter, signals the adjacent board to turn on its emitter, and transmits another I.D. on the bus. The next board's detector is thus illuminated and causes the board to latch the I.D. The system board performs the procedure for each peripheral board.
    Type: Grant
    Filed: April 27, 1987
    Date of Patent: August 8, 1989
    Assignees: American Telephone and Telegraph Company, AT&T Information Systems Inc.
    Inventor: John L. Taska
  • Patent number: D303114
    Type: Grant
    Filed: March 28, 1988
    Date of Patent: August 29, 1989
    Assignee: American Telephone and Telegraph Company, AT&T Information Systems
    Inventors: David C. Danielson, Norman K. Hart, Lynnet Koh, John N. McGarvey, Eugene A. Mills