Abstract: Ceramic spheroids having:A. a core made by firing raw materials comprising about:50-99.8 parts by weight mineral particulates;0.1 to 50 parts by weight silicon carbide; and0.1 to 15 parts by weight binder (e.g. bentonite); andB. an outer shell comprising Al.sub.2 O.sub.3 or MgO.More alumina or magnesium oxide is contained in the outer shell than in the core. The core of the ceramic spheroid has closed cell microporosity. The inventive spheroids are characterized by a density less than 2.2 g/cc and can be readily made to have a density less than 1 g/cc. These ceramic spheroids combine high strength (due to the tough outer shell) with low density (due to the closed cell microporosity) and have applications (among others) as buoyant water filtration media and low density fillers.
Type:
Grant
Filed:
June 12, 1985
Date of Patent:
December 30, 1986
Assignee:
Minnesota Mining and Manufacturing Company
Abstract: The treatment of pavement surfaces with a rapid setting high float asphalt emulsion which comprises 50 to 75 weight percent asphalt, about 0.01 to 1.0 weight percent anionic emulsifier, about 0.2 to 15 weight percent carboxylic acid esters, sufficient base to provide said emulsion with a pH greater than about 9, and water.
Abstract: Described is a raised pavement marker comprised of (referring to FIG. 1) a hollow, flexible, elastomeric body 2, a reflective film 4, and a pressure-sensitive adhesive 3. Raised portion 5 provides back support for the reflective film. The hollow body has a compressive strength of less than about 100 kiloPascals at 25 percent compression so that it yields readily to vehicle wheels traversing the marker, but it regains its approximate original shape after the wheels have passed over it.
Abstract: A receiver is disclosed for acquiring and tracking a data signal in a highly stressed environment. The receiver comprises first and second I.F. sections, a mixer for translation from the first I.F. frequency to the second I.F. frequency, a 2 KHz bandpass filter at the second I.F. frequency, signal translator for synchronous translation of the signal at the second I.F. frequency to baseband, a digitizer for complex sampling operation on the baseband signal, a microprocessor for processing the digital samples, and a numerically controlled oscillator coupled to the mixer and controlled by the microprocessor. The microprocessor formulates matched digital discrete Fourier Transform filters which drive frequency, phase and symbol lock loops at the symbol rate. Each of the loop filters is formed by symbol-rate recursive, first-order equations.
Abstract: A meter for passively logging the presence of TV viewers including circuitry for disabling the audio of a TV set, a transmitter for wirelessly transmitting the audio to a plurality of headphones, a circuit responsive to the headphones presence upon the head of a viewer for transmitting a headphone ID signal to a monitor, a receiver in the monitor for logging the fact that particular headphones are activated, and a time of day clock for logging the period of time particular headphones are activated.
Abstract: A non-woven, non-tufted skeletal mass of fibrous members in a mat-like structure for reducing liquid splash and/or spray in a region likely to be subjected to liquid impact is provided. The mat-like structure contains 75-98 percent by volume of voids and is particularly useful on motor vehicles as a material for mud flaps, mud guard lining, and wheel valances. The mat-like structure may be provided with a gutter or deflector so that water draining from the skeletal structure is deflected to one side. The mat-like structure may be made by needle-puching a fibrous web and the fibrous members may randomly be bonded to each other by use of an adhesive or welds.
Type:
Grant
Filed:
April 22, 1982
Date of Patent:
December 2, 1986
Assignee:
Minnesota Mining and Manufacturing Company
Abstract: A calibration standard simulates predetermined flying characteristics of a magnetic head for calibrating flying height testers. The standard comprises a substrate having a reflective layer supported thereon. A transparent layer is disposed over the reflective layer so that the reflective layer is disposed at a predetermined angle to a surface of the transparent layer, the predetermined angle representative of a predetermined flying angle of a head over a disk, the transparent layer having a thickness representative of a predetermined flying height of a head over a disk. A process for manufacturing and calibrating the calibration standard is also described.
Abstract: In the illustrated applicators, one of a series of pavement markers is individually dispensed from a carrier web by stripping the web back from the marker while moving the marker into wedging contact between a spring-loaded roller and the pavement. While doing so, the carrier web is kept taut between a brake shoe where it exits a magazine and an overdriven takeup roll which is locked against rotation while the marker is being moved into the wedging contact. Each pavement marker has a flat base which preferably bears a pressure-sensitive adhesive that releasably adheres the marker to the carrier web and bonds the marker to the pavement.
Type:
Grant
Filed:
April 25, 1985
Date of Patent:
November 18, 1986
Assignee:
Minnesota Mining and Manufacturing Company
Abstract: Conductive coating (20) is a thorough mixture of 0.03 parts per weight of carbon black together with 0.003 to 0.01 parts per weight of wetting agent and 20 parts of solvent, and further mixing in by low shearing mixing 1/2 to 1 part per weight of thermosetting resin. This is then sprayed into place on the substrate and thermoset. In this particular case, the substrate is exterior face sheet (12) of honeycomb structure (10) which may serve as part of a spacecraft, to electrically conduct away surface charges.
Type:
Grant
Filed:
August 13, 1984
Date of Patent:
November 18, 1986
Assignee:
Hughes Aircraft Company
Inventors:
Preston S. DuPont, Robert E. Ritter, John P. Stafford
Abstract: Stretched surface recording disk (SD) 10 comprises an annular support 12 having raised annular ridges 42 and 28 at its inside and outside diameters 22 and 30 with a base portion 24 in between the two ridges, and an annular recording medium film 14 held in radial tension and stretched across the base portion by adhering the film to attachment surfaces 48 and 36 near the inside and outside diameters respectively. The SD is annealed twice duringmanufacture to relieve stress in the stretched film 14. This annealing results in SD essentially free from track anisotropy and stress distribution anisotropy in the plane of the disk. As a result, data tracks are more stable than in previous SD, track density can be greater, and the SD is generally more reliable.
Type:
Grant
Filed:
March 14, 1985
Date of Patent:
November 18, 1986
Assignee:
Minnesota Mining and Manufacturing Company
Inventors:
Jerry L. Alexander, Sankar B. Narayan, Sten R. Gerfast, Charles E. Nelson
Abstract: A bulk polymerization process for free radical polymerization of vinyl monomers in a wiped surface reactor is disclosed. Referring to FIG. 1; monomer streams 5 (after purification and silica gel column 2) and 7 are combined with free radical initiator 9 to form a premix 16. Pump 18 transfers the premix stream 22 through static mixer 24 into a wiped surface reactor 27. The reactor can be a counter rotating twin screw extruder which produces polymer stream 36 without the need of solvent and using residence times much shorter than prior art solution or emulsion processes.Some unique pressure sensitive adhesive acrylate polymers have been produced. They are believed to have a relatively high degree of branching. The bulk polymerization process permits the manufacture of pressure sensitive adhesive articles by extruding directly from the twin screw extruder onto a substrate.
Type:
Grant
Filed:
March 28, 1984
Date of Patent:
October 28, 1986
Assignee:
Minnesota Mining and Manufacturing Company
Inventors:
Thomas A. Kotnour, Ronald L. Barber, Walter L. Krueger
Abstract: A switch (10) of the type comprising a rectangular arrangement of ports (21, 22, 23 and 24) includes a diagonally extending connector bar (35) disposed on one side of the rectangular arrangement opposite four laterally extending connector bars (31, 32, 33 and 34). The diagonally disposed connector bar is actuatable independently of the other bars. Electromagnetically driven rockers (79) or other means are provided to actuate the rods. In one realization of the switch, the ports are coaxial connectors for a microwave network. Each connector bar resides within a corresponding groove (51, 61) in a conductive housing and is independently actuatable. When actuated, a bar contacts the center conductors of two ports. The actuated bar cooperates with the walls of the containing groove to form an air-line microwave connection between the contacted ports. When the contained bar is unactuated, the groove becomes a waveguide-beyond-cutoff to isolate the respective ports.