Patent ID: 6481260
Filing Date: 2002-11-19
Classification: B21D

Abstract:
A device for embossing metal pipe comprising:a frame supported on ground; a length of core having one end detachably fixed horizontally to an upper surface of the frame having a plunger hole at a center thereof in an axis direction and a plurality of core pass through holes perpendicular to the plunger hole in a portion of the core; a first stock fixed to one side of the upper surface of the frame; first reciprocating members fixed in the first stock and the frame each for reciprocating perpendicular to the axis of the core; first segments respectively fitted to insides of the first reciprocating members for moving along the movement of the first reciprocating members; casings detachably and respectively fitted to the segments for coming into a close contact with the core as the casings move inward or moving away from the core as the casings move outward, having a plurality of casing pass through holes in an inside surface thereof opposite to the core pass through holes; a punch movably inserted in each of the core pass through holes for selectively and forcibly moving outwardly perpendicular to the core axis, to form embossing projections on the metal pipe inserted on the core; punch fall off preventing means for keeping the punch in position inside of the core pass through hole without falling off inward or outward direction including a large diametered part of the punch forming an outside portion of the punch, a small diametered part forming an inside portion of the punch smaller than the large diametered part, a step in the core pass through hole close to the plunger hole for blocking the large diametered part of the punch, and a thin cover pipe fitted tightly around the core having cover pipe pass through holes each opposite to the core pass through hole with a diameter slightly smaller than the diameter of the core pass through hole for passing the fore end of the large diametered part of the punch only; a second stock mounted on the upper surface of the frame and spaced apart from the first stock with a predetermined distance; a second reciprocating member fixed to the second stock for reciprocating in the axis direction of the core; a second segment fitted an inside of the second reciprocating member for moving along the movement of the second reciprocating member; and, a plunger detachably fixed to the second segment for moving along the movement of the second segment through the plunger hole to push the punches in the core pass through holes selectively away in a direction perpendicular to the axis of the core.