JPS57155571A - Heating roll for fixing device - Google Patents

Abstract

PURPOSE:To prevent the denting of the parts of a heating roll in contact with a pressurizing roll on account of improved rigidity and to decrease heat capacity on account of average reduction in wall thickness by forming the core of said heating roll to the wall thickness partially larger in at least >=1 places in its axial direction. CONSTITUTION:A metallic heating roll 1 is hollow and its core part 2 of a cylindrical shape in outside circumferential surface and both shaft end parts 3 are coupled to one body in disc parts 4. Thick-walled reinforcing parts 5 of constant thickness over the entire circumference are formed on the inside circumference of the core part 2 in the central position in the axial direction of the roll and the laterally symmetrical positions having prescribed spacings from this. The thick-walled reinforcing parts 5 and thin-walled parts are connected alternately adjacently to the core part 2 of the roll 1, whereby the average thickness of the core part 2 is reduced; hence, the heat capacity of the roll is decreased and the warm-up time is reduced with no increase in the electric power to be supplied.