CABLE DRAWING DEVICE WITH AT LEAST ONE THERMOPLASTIC CABLE-DUCT TUBE AND METHOD FOR DRAWING CABLES INTO CABLE-DUCT TUBES Russian patent published in 1999 - IPC

FIELD: electrical engineering. SUBSTANCE: device has cable duct with radial wall round in cross-sectional area and slide ribs made of tube material which are equally distributed over circumference of duct inner wall in wavy manner to form reversing regions between sections with constant angle of turn a and width of contact surfaces b formed in cable-duct tube between slide ribs and sheath of drawn-in cable as they come in contact. According to invention, angle of rib inclination g measured in radians satisfies equation g = r_a/L_c and ranges between 0.001 and 1.2 radians, where r is between 12 and 100 mm and L_c is length of contact sections of slide ribs between reversing regions ranging between 500 and 10 000 mm. Here, A•r = 0,16b²Z•L_c or , in case connecting sections of length are provided between sections with constant angle of turn where slip ribs are parallel to tube axis, A•r = 0,16²•Z•(0,0003r²a²+L2c

)^1/2-4L_vb•r, where A is contact surface of cable sheath at point of its intersection with slide ribs and ranges between 4.5 and 32 sq. mm; Z is number of slide ribs; cables that can be drawn in should have outer radius between 5 and 45 mm. Method used is characterized in that cables are drawn in at speed ensuring fusing of contact surfaces under effect of friction heat so that molten surfaces provide for lubricated friction condition. EFFECT: reduced traction forces under all process conditions. 4 cl, 5 dwg, 1 tbl