Patents by Inventor David L. Mack

David L. Mack has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 6396844
    Abstract: To provide either or both multiplexed and non-multiplexed (loop repeater) mode communications in the same equipment shelf between a network and plural subscriber circuits, a multi-mode backplane architecture includes a network interface multiplexer that provides time division multiplexed signal connectivity and point-to-point multiplexed signal connectivity between the network and line circuit access modules, to which the subscriber circuits are selectively ported. Each of a plurality of non-multiplexed interface connectors is configured for external connection to non-multiplexed communication links of the network and non-multiplexed communication links of the subscriber circuits. A plurality of access module card slots receive line circuit access modules that are individually programmable to provide a selected one of a plurality of diverse modes of telecommunication connectivity between the network and a subscriber circuit.
    Type: Grant
    Filed: October 9, 1998
    Date of Patent: May 28, 2002
    Assignee: Adtran, Inc.
    Inventors: David L. Mack, David R. Krueger, John B. Bartell
  • Patent number: 6347809
    Abstract: A stabilizer for flexible guards provides for the stabilization and control of flexible flaps, brush type devices, and the like as used in motor vehicle mud flaps, car washes, and in conveyor systems. The present stabilizer includes a rigid structure which completely surrounds the guard(s), and which is loosely and flexibly suspended from an overlying structure. The rigid portion of the device is preferably constructed of polyvinyl chloride (PVC) pipe or tubing, or any other suitable elongate structural material (e.g., electrical metal tubing, pipe, and/or extruded metallic or non-metallic shapes, such as Tees, channels, angles, etc.). The rigid structure is preferably suspended from the overlying structure by chains at at least both ends of the device, with an additional chain(s) optionally installed at the center area of the device.
    Type: Grant
    Filed: September 18, 2000
    Date of Patent: February 19, 2002
    Inventor: David L. Mack
  • Patent number: 5970051
    Abstract: The problem of digital data corruption heat occurs when an analog card is inserted into a card/time slot of a D4 channel bank is effectively remedied by sampling and analyzing the channel bank's transmit enable (TNEN) lead for successive frames of time slots. Unless analyzed TNEN lead samples of a channel unit time slot of interest derived over successive frames have the same logic state associated with an analog channel unit, the PCM data lead remains default-coupled to a digital data transmission lead. This prevents PCM-encoded spurious noise on the analog PAM lead from being erroneously asserted in place of serialized digital data bits that should have been passed directly from the digital data bus to the PCM bus.
    Type: Grant
    Filed: January 2, 1997
    Date of Patent: October 19, 1999
    Assignee: Adtran, Inc.
    Inventors: David L. Mack, Michael W. Elliott, Clifford Hall
  • Patent number: 5940374
    Abstract: A D4 channel bank data bus monitoring scheme automatically determines if a channel unit connector slot is occupied, without having to gain physical access to the interior of the channel bank cabinet and inspect the channel bank's backplane slot positions. To this end, for a respective channel unit connector slot the channel bank's transmit data bus, which is initially pulled high via a pull-up resistor, is monitored for an all `1`s state. If the data on the bus is not all `1`s, then it is inferred that a channel unit is installed. If an all `1`s state is not detected, then, during the next time slot for that channel unit, the bus is decoupled from the pull-up resistor and coupled instead to a `soft` pull-down resistor. If the data on the bus is now all `0`s, it is inferred that the previously read all `1`s condition was due to the fact that no channel unit is installed, and the channel unit connector slot is declared as empty.
    Type: Grant
    Filed: September 3, 1996
    Date of Patent: August 17, 1999
    Assignee: Adtran, Inc.
    Inventors: David L. Mack, Jason F. McCullough, Stacy M. Murphree