Method and apparatus for producing can bodies
AssigneeFried. Krupp Gesellschaft mit beschrankter Haftung
InventorsNorbert Lentz, Harald Schmidt
Life of this patent
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Abstract
A method and apparatus for producing can bodies, wherein blanks are laterally centered after removal from a magazine, are engaged in the center of their rear edge and are transported into a shaping station in which initially the center section of the blank is bent into its final shape. While doing this, a central force and friction lock is produced between a transporting means and the deformed blank to realize reliable guidance of the already partially bent blank. To further transport the blank, it is contacted at its rear edge in the already completely bent region by two lateral transporting devices and is advanced to a seam forming station, while the opposite longitudinal edges of the blank are brought to an adjoining relationship.
Claims22
A method of producing can bodies from individual, planar cut blanks having a central region bordered by two lateral regions, the method comprising the following steps:
- (a) transporting the blank into a shaping station by a first transporting means which engages the central region of the blank at its trailing edge;
- (b) bending, to a final shape, solely the central region of the blank around an inner shaping mandrel to a circumferential angle of 120.degree. to 190.degree. while leaving the lateral regions unbent;
- (c) clamping, simultaneously with step (b), said central region between said mandrel and said transporting means by way of friction forces derived from the forced deformation of the central region;
- (d) transporting the blank for further shaping, after step (b), by a second transporting means which engages the trailing edge of said blank at two lateral locations on respective sides of said central region, said two lateral locations having already received the shape of the final can body as a result of step (b);
- (e) bending, after step (b), said lateral regions of said blank;
- (f) guiding opposite longitudinal side edges of said blank into an adjoining position;
- (g) forming a longitudinal seam along the adjoining side edges;
- and
- (h) continuously linearly advancing the blank during steps (a) through (g).
An apparatus for forming a can body from individual planar blanks comprising:
- a frame,
- an outer elongated shaping cage attached to said frame, and including a plurality of longitudinal elements and having an entrance end and an exit end,
- an inner shaping mandrel comprised of individual, axially parallel guide rods positioned within said cage, and having a longitudinal center axis and a cross-sectional outline perpendicular to said axis corresponding to the desired inner cross-sectional shape of said can body, wherein an underside of the shaping mandrel has a central recess;
- first transporting means for transporting said blank between said cage and said mandrel, extending over a first portion of the length of said shaping mandrel in its axial direction, said first transporting means being equipped with pawls extending into said recess of said shaping mandrel and with engaging means for engaging said blank between said transporting means and said shaping mandrel,
- means for guiding the edges of the can body,
- said longitudinal elements at said entrance end of said outer shaping cage forming an initial plane extending at least one blank width tangential to said mandrel,
- said longitudinal elements being gradually curved to surround said mandrel at said exit end of said cage in the shape of said can body, and
- second transporting means extending over a second portion of the length of said mandrel in said axial direction, for transporting said blank between said cage and said mandrel and out of said exit end, said second transporting means including two advancing means, each arranged laterally of a longitudinal center plane of the mandrel, for engaging and advancing said blank.
Dependencies are inferred from the claim text.