Patent ID: 6084222
Filing Date: 2000-07-04
Classification: B21B,B23K

Abstract:
A sheet bar joining apparatus, comprising:a delivery-side clamp adapted to clamp a rear end portion of a preceding sheet bar;an entry-side clamp adapted to clamp a front end portion of a succeeding sheet bar;a heater provided between said delivery-side clamp and said entry-side clamp, said heater generating a flux that induces eddy currents in said rear end portion of the preceding sheet bar and said front end portion of the succeeding sheet bar to heat said rear end and front end portions;anti-buckling plates having an upper plate and a lower plate, said anti-buckling plates adapted to prevent buckling of the sheet bars by holding a rear end of the preceding sheet bar and a front end of the succeeding sheet bar between the upper and lower plates;an upper comb tooth portion and a lower comb tooth portion formed in the upper and lower anti-buckling plates, respectively;a heat resistant insulator provided at a surface of each of the upper comb tooth portion and the lower comb tooth portion in a surface facing the sheet bars; anda plurality of first groove portions provided in the surface of each of the upper comb tooth portion and the lower comb tooth portion facing the sheet bars, said groove portions being provided in a width direction of the upper comb tooth portion and the lower comb tooth portion to suppress eddy current formed in a vertical direction within each of the upper and lower comb tooth portions due to the flux passing obliquely through a side face of said upper and lower comb portions.