Patent ID: 6213369
Filing Date: 2001-04-10
Classification: B21D

Abstract:
A material feeding apparatus comprising:a first gripper apparatus which performs material clamping and unclamping operations by a first stationary gripper and a first movable gripper;a second gripper apparatus which performs material clamping and unclamping operations by a second stationary gripper and a second movable gripper;a sliding block which supports said first gripper apparatus and can oscillate in a material transfer direction;a cam apparatus having a first cam which is fixed to an input shaft continuously rotated in one direction and has a predetermined cam surface shape for converting a rotating motion of said input shaft into a linear motion of said sliding block, a second cam which is fixed to said input shaft and moves said first movable gripper between a clamping position at which said first movable gripper is moved near said first stationary gripper and an unclamping position at which said first movable gripper is moved apart from said first stationary gripper and a third cam which is fixed to said input shaft and moves said second movable gripper between a clamping position at which said second movable gripper is moved near said second stationary gripper and an unclamping position at which said second movable gripper is moved apart from said second stationary gripper;a first gripper sliding apparatus having a swinging arm which swings in correspondence to a rotation of said first cam, and connecting means which operatively connects said swinging arm to said sliding block so as to convert a swing motion of said swinging arm into a linear motion of the sliding block;a first gripper operating apparatus which operatively connects said second cam to said first movable gripper;a second gripper operating apparatus which operatively connects said third cam to said second movable gripper; andfirst urging means which always urges so that said sliding block, said connecting means and said swinging arm are closely connected to each other along a transfer path of a force from said first cam to said sliding block.