Filtering screen and support frame therefor

• US 6,692,599 B2
• Filed: 03/13/2002
• Issued: 02/17/2004
• Est. Priority Date: 03/01/1997
• Status: Expired due to Term

• Current Assignee: United Wire Ltd (Schlumberger NV)
• Original Assignee: United Wire Ltd (Schlumberger NV)
• Inventors: Hughes, Andrew, Cook, Gordon James, Bailey, Arthur Robert, Hartnup, George Charles, Stewart, Dugald
• Primary Examiner(s): Aftergut, Jeff H.
• Assistant Examiner(s): CORCORAN, GLADYS JOSEFINA-PIA
• Application Number:
  US10/097,920
• Publication Number:
  US 20020096470A1
• Time in Patent Office: 706 Days
• Field of Search: 210/495, 156/94, 156/98, 264/36.1, 264/36.22
• US Class Current: 156/94
• CPC Class Codes: B01D 29/012 Making filtering elements making bag, cage, hose, tube, sleeve or like filtering elements B01D29/111
• CPC Class Codes: B01D 29/05 supported
• CPC Class Codes: B01D 29/445 Bar screens
• CPC Class Codes: B07B 1/46 Constructional details of screens in general; Cleaning or heating of screens
• CPC Class Codes: B07B 1/4618 Manufacturing of screening surfaces
• CPC Class Codes: B07B 1/4627 Repairing of screening surfaces
• CPC Class Codes: B07B 1/4645 Screening surfaces built up of modular elements
• CPC Class Codes: B07B 1/4663 Multi-layer screening surfaces
• CPC Class Codes: B07B 1/4672 Woven meshes
• CPC Class Codes: B07B 1/48 Stretching devices for screens
• CPC Class Codes: B07B 2201/02 Fastening means for fastening screens to their frames which do not stretch or sag the screening surfaces
• CPC Class Codes: B29C 2045/14442 injecting a grill or grid on the insert
• CPC Class Codes: B29C 45/14336 Coating a portion of the article, e.g. the edge of the article B29C45/14573 and B29C45/14598 take precedence
• CPC Class Codes: B29C 70/56 Tensioning reinforcements before or during shaping
• CPC Class Codes: B29C 70/82 Forcing wires, nets or the like partially or completely into the surface of an article, e.g. by cutting and pressing
• CPC Class Codes: B29C 70/885 with incorporated metallic wires, nets, films or plates as lost heating elements B29C35/0272, B29C61/0625
• CPC Class Codes: B29L 2031/14 Filters optical filters B29L2011/0066, sieves or screens B29L2031/737
• CPC Class Codes: B29L 2031/737 Articles provided with holes, e.g. grids, sieves nets B29L2028/00
• CPC Class Codes: Y10T 29/49616 Structural member making
• CPC Class Codes: Y10T 29/4962 Grille making
• CPC Class Codes: Y10T 29/49895 : Associating parts by use of aligning means [e.g., use of a drift pin or a "fixture"]
• CPC Class Codes: Y10T 428/12347 : Plural layers discontinuously bonded [e.g., spot-weld, mechanical fastener, etc.]
• CPC Class Codes: Y10T 428/12361 : having aperture or cut
• CPC Class Codes: Y10T 428/12444 : Embodying fibers interengaged or between layers [e.g., paper, etc.]
• CPC Class Codes: Y10T 428/12965 : Both containing 0.01-1.7% carbon [i.e., steel]
• CPC Class Codes: Y10T 428/249923 : Including interlaminar mechanical fastener
• CPC Class Codes: Y10T 428/298 : Physical dimension

Abstract

A method of repairing or refurbishing a filter screen is described. The type of screen is defined in the specification. The repair or refurbishment is effected by stripping worn or damaged wirecloth from the surface of the frame and placing fresh cloth over the frame and tensioning it as appropriate. Heat is then applied so as to soften surfaces of the frame over which wirecloth is stretched, so that the latter can penetrate softened plastics material in the surfaces and become embedded therein. The frame and its associated fresh cloth is allowed to cool, after which the applied tensioning is removed. Exposed edges of the wirecloth can be trimmed back to the surrounding flange. Plastics material may be applied to the surface of the frame which is to receive the new wirecloth, before the latter is fitted, to provide additional plastics material for bonding the wirecloth to the frame. Alternatively the stripped frame may be inserted in a mould, and fresh polymer material is injected into the mould so as to reform ridges on the surfaces of the frame similar to those which existed when the frame was first manufactured, before the wirecloth is applied thereto.

Claims

1. A method of repairing or refurbishing a litter screen comprising a support frame with a surface, a surrounding flange and a worn or damaged wirecloth, comprising the steps of:

(a) stripping worn or damaged wirecloth from the surface of the frame;

(b) inserting the frame in a mould and injecting fresh polymer material into the mould so as to reform ridges on the surface of the frame corresponding to those which existed when the frame was first manufactured, before fresh wirecloth is applied thereto,

(c) placing fresh wirecloth over the frame and tensioning it as appropriate;

(d) applying heat so as to soften the frame surface over which the wirecloth is stretched, so that the latter can penetrate softened plastics material of the frame surface and become embedded therein;

(e) allowing the frame and its associated fresh wirecloth to cool;

(f) removing tensioning applied; and

(g) trimming back exposed edges of the wirecloth back to the surrounding flange.