BLANK OF ENVELOPE OF LAMINATE ARTICLES AND APPARATUS FOR MAKING IT Russian patent published in 2003 - IPC

FIELD: plastic metal working, namely production of laminate sleeve type or tubular articles. SUBSTANCE: blank of envelope of laminate articles is in the form of double-wall sleeve with outer and inner hollow cylindrical portions mutually joined by means of annular bottom part. Between outer cylindrical and bottom portions at one side and between inner cylindrical and bottom portions at other side there are respectively outer and inner inlet zones. Outer inlet zone is in the form of hollow truncated body of revolution having constant diameter of cavity and variable thickness of wall along its height. Inner inlet zone is in the form of hollow cylinder with variable thickness of wall along its height and with cavity whose diameter lowers towards cylindrical portion. Large bases of inner and outer inlet zones are joined respectively with outer and inner hollow cylindrical portions. Apparatus for making blank of envelope of laminate articles includes punch and die. Cavity of die has hollow cylindrical portion and bottom portion in the form of ring. In cavity of die there is additional shaping zone in the form of hollow truncated cone arranged between hollow cylindrical and bottom portions. Large base of cone is joined with hollow cylindrical portion. Inner surface of shaping zone is cone one and it has diameter lowered towards cylindrical portion. EFFECT: lowered deforming effort at initial time moment of calibrating, enhanced quality of laminate products. 2 cl, 7 dwg, 1 ex