BOBBIN Russian patent published in 1997 - IPC

FIELD: fishery, in particular, trawl parts. SUBSTANCE: central part of lower seine rope of trawl is equipped with bobbins operating in rolling motion mode. Each bobbin has body circumscribed into short cylinder and provided with axial opening. Bobbin body is made from material with density close to that of water, preferably rubber. Bobbin body has rim, disk, hub and stiffening ribs. Mid plane of disk coincides with mid planes of rim and hub to make the plane of symmetry. Length of rim is equal to that of hub and makes length of bobbin. At least 5-9 stiffening ribs are equally spaced between rim and hub at each side of disk. Ribs are arranged in circular pattern and have height equal to half the difference between length of bobbin and thickness of disk. Other sizes of ribs are equal. Inner outlines of rim and outer rims of hub in axial sections of bobbin and side outlines of rib sections are sloped at an angle of 10-30 deg. Thickness of members is increasing from end surfaces to plane of symmetry. Junctions of facets of cavities defined between rim, disk, hub and ribs are made rounded. Sizes of main members of bobbin are set within the range of: length (0.2-0.4)D, disk thickness (0.05-0.1)D, thickness of rim and hub measured in end planes (0.04-0.08)D, stiffening rib thickness measured in end planes (0.01-0.03)D, radii of rounded junctions: in end planes (0.04-0.2)D, in longitudinal and cross sections (0.02-0.05)D, where D is outer diameter of bobbin. EFFECT: increased efficiency and enhanced reliability in operation. 3 dwg, 2 tbl