Patent ID: 8308036
Filing Date: 2012-11-13
Classification: B21C,B21D,B65H

Abstract:
1. A sheet material feeding apparatus comprising: a pair of rolls that interpose therebetween a sheet material to intermittently feed the same to a press apparatus; a roll clearance adjusting device that adjusts a clearance between the pair of rolls according to the thickness of the sheet material; and a release device that temporarily releases the sheet material having been interposed by the pair of rolls just before the sheet material fed to the press apparatus is subjected to press working, and wherein: the pair of rolls comprise a main roll driven by a drive motor and a sub-roll driven through the sheet material by the main roll, the roll clearance adjusting device displaces the main roll up and down to adjust a clearance between the main roll and the sub-roll, the release device includes a sub-roll guide that rotatably supports the sub-roll and that moves up and down together with the sub-roll, a rectilinear cam that is movable in a direction parallel to a longitudinal axis of the sub-roll and having an upper surface with a cam surface, a cam follower mounted to the sub-roll guide and that is supported for rotation about an axis that is substantially perpendicular to the longitudinal axis of the sub-roll to engage with the cam surface of the rectilinear cam, and a control device that moves the rectilinear cam in the direction parallel to the longitudinal axis of the sub-roll in synchronism with the operation of the press apparatus to displace the sub-roll up and down through the cam follower and the sub-roll guide, the cam surface having a shape for displacing, via the cam follower and the sub-roll guide, the sub-roll between an upper position and a lower position according to movement of the rectilinear cam in the direction parallel to the longitudinal axis of the sub-roll, and the cam surface having an upwardly raised portion extending substantially parallel to the longitudinal axis of the sub-roll for positioning the sub-roll at the upper position and a downwardly recessed portion for positioning the sub-roll at the lower position.