US 4,818,403 AGranted

Double cylinder screen

AssigneeNagaoka Kanaami Kabushiki Kaisha

InventorTadayoshi Nagaoka

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Abstract

A double cylinder screen comprises an inner reinforcing cylinder which performs a pressure-resisting function against an external pressure and an outer screen cylinder which performs a screen function. The inner reinforcing screen comprises inner rods disposed cylindrically at a predetermined interval in the axial direction of the screen and a spiral reinforcing member wound on the outside of the inner rods and welded to the inner rods. The outer screen cylinder comprises screen rods disposed at a predetermined interval in the axial direction on the outer periphery of the inner reinforcing member and a wire wound spirally about the outside of the screen rods and welded to the screen rods. The width of a slit of the reinforcing member is larger than the width of a slit of the wire. The double screen cylinder is improved in its stength and can be manufactured without requiring a costly jig.

Claims9

Dependent claims

A double cylinder screen assembly having no internal extraction pipe comprising an inner cylindrical major pressure resistant member and a cylindrical outer screen member, said inner pressure resistant member comprising:

radially spaced-apart inner rods extending in the axial direction of the double cylinder screen;
and
spiral reinforcing means wound at a predetermined pitch on the outside surface of said inner rods, said spiral reinforcing means including axially spaced-apart turns defining a plurality of first openings, wherein portions of said spiral reinforcing means are affixed to portions of said inner rods,
radially spaced-apart screen rods extending in the axial direction of the double cylinder screen and in pressure contact with the outer surface of the spiral reinforcing means of said inner pressure resistant member;
and
wire means spirally wound at a predetermined pitch on the outside surface of said screen rods and including axially spaced-apart turns defining a plurality of second openings, wherein portions of said wire means are affixed to portions of said screen rods,
wherein the width of said first openings are larger than the width of said second openings.

4 more elements

Dependencies are inferred from the claim text.