PURPOSE: To elevate the detection sensitivity, by arranging a cooling liquid passage having an intake port on the side of a bobbin and a discharge port on the inner surface where to pass material to be inspected so as to be in the tangential direction with the inner surface viewed from the side of the bobbin.
CONSTITUTION: A cooling liquid is fed at an inlet 8 to fill a water jacket 10a provided on flanges 2 and 3 over the circumference thereof and discharges from a discharge port 13 passing through a passage 12 from an intake port 10b provided on the side of the bobbin 6. The cooling liquid fed at the inlet 8 enters the passage 12 from the intake port 10b through the water jacket 10a but scatters along the inner circumference as the passage 12 is provided in the tangential direction with the inner surface of the bobbin 6. Thus, the sufficient cooling effect thus obtained can eliminate the sleeve heretofore equipped thereby preventing loss in vortex.
NITSUTA SHIGEYUKI
KOYAMA SUKESADA
| JPS4934387A | 1974-03-29 | |||
| JPS5412790A | 1979-01-30 |