US PATENT SUBCLASS 166 / 228
.~ Porous material
Current as of: June, 1999
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DEFINITION
Classification: 166/228
(under subclass 227) Devices comprising a straining portion made up of a mass of material having fine, irregularly shaped or tortuous pores or channels.
(1) Note. The material is usually a body of gravel, sand or porous concrete.
SEE OR SEARCH THIS CLASS, SUBCLASS:
51, for apparatus for placing porous beds.
230, for screens using woven fabric (wire mesh) to form straining openings.
276, for a process for providing a porous mass of adhered filter material in the well. 278, for a process of graveling or filter forming.
SEE OR SEARCH CLASS
210, Liquid Purification or Separation,
496, for shaped porous filter elements of general utility, and subclass 510.1 for a filter material comprising a porous unitary mass.
428, Stock Material or Miscellaneous Articles,
304.4+, for a stock material product in the form of a composite sheet or web, in which one component is porous or cellular.
