GB565345A - Plastic well screen - Google Patents

Abstract

565,345. Well screens. DEHN, F. B. (Johnson, Inc., E. E.). Dec. 28, 1942, No. 18423. [Class 46] [Also in Group XXI] A well screen comprises a number of elements made of plastic material and formed so that, when groups of the elements are held secured together end to end and in tiers they form a hollow member with drainage slots, longitudinal steel rods extending through and being held within the abutting ends of the members. In Figs. 2 and 4, arcuate members 10 are formed of plastic material, such as that known under the Registered Trade Mark " Bakelite," and all of the same curvature, and preferably of inwardly tapering cross-section ; each end 12 of the members 10 is narrower than the body and apertured to permit threading on to metal rods 14 which also pass through flanges of end fittings 18, 19, which may be threaded to form unions. Continuous metal rings 25 are provided between groups of segments 10 and are deeper radially than the segments. In Fig. 13, the. members 10 are provided adjacent their ends with thickened portions 26 which contact to leave slots 27 of desired width. In Fig. 7, the separate members 10 are replaced by wide arcuate strips 28 with a number of slots 29 moulded or cut therein, each strip having at one end a central extension 32 and at the other end spaced extensions 34, 35, to permit threading of the strips on the rods ; in another form, the slots 29 are arranged vertically. In Fig. 17, each segment 49 has halved ends 55, 57, fitting together so that the segments form continuous rings ; one or more washers 60 are provided on each rod 14 between adjacent rings to leave slots of desired width.