Patent GB-727652-A (GB)
Title: An improved trawl protector
IPC: A01K75/00
Filed: 1951-07-12
Abstract: 727,652. Trawl fishing. LOWTHER, J. G. Oct. 8, 1952 [July 12, 1951 ; Aug. 2, 1951 ; Oct. 15, 1951 ; Nov. 22, 1951 ; Dec. 14, 1951], Nos. 16535/51, 18283/51, 23928/51, 27377/51, and 29316/51. Class 48. A protective mat adapted to be secured to the lower part of a trawl net is formed by a sheet of manufactured flexible material the thickness of which does not exceed 3/16 inch and the weight per square foot of which does not exceed 10.5 ozs., the sheet being provided with aligned perforations adjacent the leading edge. The mat is formed by rubber sheets 5 reinforced with sheets 6 of canvas or cotton duck or polythene or nylon. The mat may be of three or five or seven or nine ply-structure. Slits of V or U- shape are formed in the canvas or cotton duck at the leading edge of the mat and the aligned perforations are located either between the slits or within the slits, one to each slit. In the latter case the plies are replaced in the region of the perforations by a single thickness of rubber which is recessed on both sides and fitted with canvas or cotton duck washers. Additional perforations 9 may extend part way down each side of the mat and one or more additional rows of perforations 10 may extend across the mat parallel to the leading edge ; slits 11 are situated in the canvas or cotton duck between these additional perforations. A cushioning element preferably of expanded rubber may be located at the leading edge of the mat. The perforations at the leading edge may be located in the cushioning element when it is made of rubber of the same consistency as the mat. The perforations at the leading edge may be located in a series of forwardly projecting rubber tabs. Perforations may also be provided at the trailing edge. The perforations are generally circular but those at the leading edge may be segmental. The perforations may be reinforced by metal or plastic eyelets or by stitching. The leading edge may be cut away in a series of curved indentations, One or both faces of the mat may be provided with rubber ribs extending in longitudinal, lateral or diagonal directions. The edges of the mat mav be made of thickened material with or without additional fabric strips. The sides and trailing edges may be reinforced with stitching. Rows of stitching may be disposed diagonally or parallel to the longitudinal or lateral edges. The mat may be provided with a central reinforcing panel extending from leading to trailing edges and sufficiently wide to include the three central perforations at the leading edge. A composite mat is formed by bonding two or' more mats together at their leading edges. In a composite mat consisting of two mats of equal length the lower mat has a leading edge of the same width as the upper mat but is waisted rearwards. Cork may be attached to the mat. A plurality of mats may be attached to the undersurface of the trawl such that the trailing edge of one mat overlies the leading edge of the adjacent rearward mat. The mats may be attached to the net by rubber rings which pass through the perforations so as to provide double loops to which twine seizings may be fastened. Specification 312,805, [Class 48], is referred to.