Apparatus for jointing plate materials

Claim 1

An apparatus for jointing overlapping plate materials comprising: a die having a top end surface, a base end surface, an axial die hole opened on said top end surface and including an inner peripheral surface slanting radially outwardly away from said top end surface, the axially inner end of said peripheral surface being located nearer to said top end surface than said base end surface, means defining a plurality of slits extending in the axial direction of said axial die hole from said top end surface to a point located nearer to said base end surface than the axially inner end of said peripheral surface of said die hole to permit separation of said die and said peripheral surface into a plurality of independent segments and to permit said segments to be radially outwardly elastically bendable around a base end portion which is adjacent to said base end surface of said die, and means defining a circular hole at the base end of each one of said slits to diffuse the stress concentrated at the base end of each one of said slits when the segments are radially outwardly elastically bent; a base section member disposed inside said die hole and capable of moving along the central axis of said die hole between a first position wherein the top end surface of said base section member is located near and around the opening of said die hole and a second position wherein the top end surface of said base section member is located at the axially inner end of said peripheral surface of said die hole; urging means for urging the base section member toward the first position thereof; and punch means reciprocally movable between a first position wherein said punch means is out of said die hole, and a second position wherein said punch means is inserted into said die hole against the urging force of said urging means for (i) pinching a portion of said overlapping plate materials between said punch means and said upper end surface of said base section member, (ii) drawing said portion of said overlapping plate materials said die hole, and (iii) extending said pinched portion of said overlapping plate materials along the radial direction of the die hole by pressing said pinched portion in conjunction with the upper end surface of said base section member when said base section member reaches its said second position, said punch means thereby forming a joint having a side wall conforming to said outwardly slanting peripheral surface of said die hole from the drawing portion of said overlapping plate materials; wherein said outwardly slanting peripheral surface of said die hole constitutes joint-discharge means for permitting said joint of said overlapping plate materials to be discharged from said die hole when said base section member is moved from its said second position to its said first position by the urging force of said urging means, said joint-discharge means for elastically bending said segments of said die radially outwardly in response to sliding contact between said conforming wall of said joint and said outwardly slanting peripheral surface of said die hole established during movement of said base section member from its said second position to its said first position whereby said joint is discharged from said die hole.

Claim 2

An apparatus for jointing overlapping plate materials comprising: a die having a top end surface, a base end surface, an axial die hole opened on said top end surface and including an inner peripheral surface slanting radially outwardly away from said top end surface, the axially inner end of said peripheral surface being located nearer to said top end surface than said base end surface, means defining a plurality of slits extending in the axial direction of said axial die hole from said top end surface to a point located nearer to said base end surface than the axially inner end of said peripheral surface of said die hole to permit separation of said die and said peripheral surface into a plurality of independent segments and to permit said segments to be radially outwardly elastically bendable around a base end portion which is adjacent to said base end surface of said die, and means defining a circular hole at the base end of each one of said slits to diffuse the stress concentrated at the base end of each one of said slits when the segments are radially outwardly elastically bent; a base section member disposed inside said die hole and capable of moving along the central axis of said die hole between a first position wherein the top end surface of said base section member is located near and around the opening of said die hole and a second position wherein the top end surface of said base section member is located at the axially inner end of said peripheral surface of said die hole; urging means for urging the base section member toward the first position thereof; and punch means reciprocally movable between a first position wherein said punch means is out of said die hole, and a second position wherein said punch means is inserted into said die hole against the urging force of said urging means for (i) pinching a portion of said overlapping plate materials between said punch means and said upper end surface of said base section member, (ii) drawing said portion of said overlapping plate materials said die hole, and (iii) extending said pinched portion of said overlapping plate materials along the radial direction of the die hole by pressing said pinched portion in conjunction with the upper end surface of said base section member when said base section member reaches its said second position, said punch means thereby forming a joint having a side wall conforming to said outwardly slanting peripheral surface of said die hole from the drawing portion of said overlapping plate materials; wherein said outwardly slanting peripheral surface of said die hole constitutes joint-discharge means for permitting said joint of said overlapping plate materials to be discharged from said die hole when said base section member is moved from its said second position to its said first position by the urging force of said urging means, said joint-discharge means for elastically bending said segments of said die radially outwardly in response to sliding contact between said conforming wall of said joint and said outwardly slanting peripheral surface of said die hole established during movement of said base section member from its said second position to its said first position whereby said joint is discharged from said die hole.