Patents Represented by Law Firm Parmelee, Bollinger, Bramblett & Drumm
  • Patent number: 4539229
    Abstract: The invention relates to a method for providing a shaped carbon article of low green or crude density and high porosity, in particular for heat insulation, by means of which it is intended to produce shaped carbon articles of actually any dimensions and configurations from comparatively inexpensive organic materials, also from waste products from the paper-making industry. According to the invention, this is done in that paper particles in platelet form having an average diameter of from 0.5 to 5 mm and an average thickness of from 0.01 to 1 mm and/or in strip form having an average length of from 5 to 100 mm, an average width of from 0.5 to 10 mm and an average thickness of from 0.01 to 1 mm, which include an ash content of from 0.005 to 5%, are impregnated with a carbonaceous binder, in that the paper particles are thereupon shaped to form an article and said article is then through a corresponding temperature treatment condensed, carbonized and optionally graphitized.
    Type: Grant
    Filed: June 25, 1984
    Date of Patent: September 3, 1985
    Assignee: C. Conradty Nurnberg GmbH & Co KG
    Inventor: Franz Schieber
  • Patent number: 4523190
    Abstract: Switching system for transmitting program or data signals from an exchange to a number of subscriber posts, in which the processing of selection signals received by the exchange from the subscriber posts, the tuning of oscillators in the exchange, and the eventual correction of a drifting oscillator are carried out in separate control loops. In a first control loop, the subscriber posts are scanned for selection signals at a high scanning rate. In a second control loop, oscillators which must be tuned to a frequency corresponding to a received selection signal, are scanned and properly tuned within a scanning period. In a third control loop, all oscillators are scanned sequentially and a correction signal is provided if frequency drift has occurred in any oscillator.
    Type: Grant
    Filed: July 27, 1982
    Date of Patent: June 11, 1985
    Assignee: Deltakabel B.V.
    Inventor: Minno De Roo
  • Patent number: 4521764
    Abstract: A signal-controllable attenuator comprising a 17-bit multiplying-type digital-to-analog converter having an R/2R ladder network to set the bit weights, and controlled by a 6-bit remotely-generated command signal to vary the attenuation in steps of 1.5 dB through a range of 88 dB. The 1.5 dB steps are controlled by a 4-bit code signal responsive to two bits of the command signal. The 4-bit code signal is directed to four successive bit input terminals of the converter. Which four DAC input terminals are selected is controlled by a shifting matrix which shifts the four bits along the DAC input terminals to a position determined by the other four bits of the command signal.
    Type: Grant
    Filed: December 31, 1981
    Date of Patent: June 4, 1985
    Assignee: Analog Devices Incorporated
    Inventor: David P. Burton
  • Patent number: 4511413
    Abstract: The new process makes it possible to produce stable buried Zener diodes in large-sized wafers where slow ramping of diffusion temperatures is required to avoid crystal damage and other adverse effects. The process includes an initial deep diffusion of p type dopant carried out in two separate steps. In the first step, a diffusion of p dopant is made and is partially driven in. Thereafter, a second diffusion of p dopant is made over the first diffusion and both diffusions are further driven in to the required degree. The Zener diode is completed by still further diffusions including an n dopant diffusion to establish a sub-surface breakdown junction with the first two p dopant diffusions. The first two p dopant diffusions use the same mask window, and preferably are made during the isolation diffusion sequence for the wafer.
    Type: Grant
    Filed: October 5, 1983
    Date of Patent: April 16, 1985
    Assignee: Analog Devices, Incorporated
    Inventors: Ralph C. Tuttle, Richard S. Payne
  • Patent number: 4509964
    Abstract: A gas chromatographic column comprising synthetic fused silica tubing irradiated in its raw state with gamma radiation of pre-selected dosage and dosage rate. The column further comprises a stationary phase coating of cyano-silicone immobilized and stabilized by cross-linking in situ by means of further irradiation by gamma radiation.
    Type: Grant
    Filed: January 4, 1984
    Date of Patent: April 9, 1985
    Assignee: The Foxboro Company
    Inventors: John A. Hubball, Eugene F. Barry