Abstract: A novel optical filtering system for a laser bar code scanner having narrow band-pass characteristics is disclosed. The optical filtering system has two different optical filtering elements which are disposed in a scanner housing in a spatially separate relationship. One of the optical filtering elements is positioned inside of the scanner housing in front of and close to the light detection element. The other optical filtering element is positioned in the light transmission aperture of the scanner housing and forms the scanning window. The optical filtering characteristics of the scanning window obscure the internal components of the scanner from plain view making the scanner appear more aesthetically pleasing. Together the optical filtering element cooperate to form a narrow-band pass filter to provide for better light collection and scanning.

Abstract: A laser bar code symbol scanner employing a narrow band-pass optical filtering system of novel construction is disclosed. A first optical filtering element is installed in the light transmission aperture of a bar code scanner housing. A second optical filtering element is installed inside the scanner housing near the light detecting element. The first and second optical filtering elements have wavelength selective properties such that taken together they cooperate to form a narrow wavelength band-pass optical filtering system which allows only transmission of light at and around a certain predetermined wavelength into the photodetector element. The present invention also hides aesthetically unappealing electro-optical components mounted in the scanner housing from plain view and the optical filtering elements of the system can be easily and inexpensively manufactured without compromising the performance of the scanner.

Abstract: The invention relates to electrostatic separation of coal from toxic and pyritic elements and ash compounds. More particularly this invention relates to separation of coal from refuse material by imparting opposite electrostatic charges to coal and refuse particles, passing them between oppositely charged electrodes and mechanically separating the electrostatically attracted diverging coal and refuse particles. The electrostatic attraction and divergent separation process is maximized by performing the charging and separation functions within a continuously vacuum reduced atmosphere. The use of a vacuum exhaust to continuously remove water and water vapor can prevent charge dissipation of the coal particles through charge transfer to water and water vapor. Additionally, the vacuum reduced atmosphere can prevent impairment of electrostatic influence due to gas turbulence.

Abstract: A spinning band device for use in a distillation process including a particular pattern of apertures. The band is made of of an elongated strip, either metal screen or Teflon, twisted about its longitudinal center. Both embodiments contain frayed or jagged edges to create turbulences within a mixture and scrape the inner wall of a distillation column. The novel features of this band are the large apertures, which a situated on the longitudinal centerline for the metallic embodiment and scattered on the outer face for the Teflon embodiment, combined with the use of a plurality of spinning blades. Experimental testing and empirical data has proven this type of band to yield a significant increase in fractionating efficiency over the conventional two bladed bands without apertures.