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US 5,775,060 AGranted
Process for forming wrappers of thin sheet materials and a device for carrying out same
AssigneeSoremartec S.A.
InventorPietro Ferrero
Life of this patent
Estimating the term…
Abstract
This invention pertains to a method and apparatus for wrapping an article, wherein a metal foil is pleated and then formed in to a dished shape such that the pleats unfold, and then an article is placed within this dished shape.
Claims34
A method of wrapping an article having at least one rounded portion, comprising the steps of:
- (a) providing a first sheet of material on the order of tens of microns thick and having a coating thereon which can perform a self-lubricating function;
- (b) pleating said first sheet of material gradually, progressively, and symmetrically from a central region thereof towards outer regions thereof, thereby forming symmetrical meridional pleats in a pleated portion of said first sheet of material, said pleating step including maintaining said first sheet of material generally flat and causing limited movement of said first sheet of material from said outer regions thereof toward said central region thereof while said pleats are being formed, said pleating step further including subjecting said first sheet of material to restraining action which opposes said limited movement of said first sheet of material from its outer regions toward its central region;
- (c) forming the pleated portion of said first sheet of material into a dished shape while substantially eliminating said pleats from said pleated portion by unfolding-type expansion of said pleats, thereby yielding a substantially smooth, wrinkle-free surface;
- (d) inserting an article into said dished shape and then joining a second sheet of material to said first sheet of material along a closed line such that said article is completely surrounded by said first and second sheets of material;
- and
- (e) cutting said first and second sheets of material along said closed line, thereby forming a rim which projects outwardly from said closed line.
3 more elements
A method for forming wrappers for food articles, the method comprising the steps of:
- providing a sheet of metallic foil;
- forming pleats in an area of the sheet;
- and
- forming said area into a dished shape such that the pleats are virtually entirely eliminated in the area of the sheet forming the dished shape by unfolding-type expansion of the pleats, thereby yielding a generally smooth, substantially wrinkle-free surface.
1 more element
A method for forming a wrapper for an article, the method comprising the steps of:
- providing a sheet of material having a thickness on the order of tens of microns;
- forming a predetermined area of the sheet of material into a dished shape;
- and
- forming pleats in the sheet of material only in the predetermined area, prior to formation of the dished shape, the pleats being of a size such that they are virtually entirely eliminated during formation of the dished shape by unfolding-type expansion of the pleats, thereby yielding a generally smooth, substantially wrinkle-free surface.
1 more element
A device for forming pleats in a portion of sheet material which subsequently is to be formed into a dished shape, the device comprising:
- a male die element which has ribs for forming the pleats in the portion of sheet material, the ribs being arranged along meridians of a first pleating area corresponding to the portion of sheet material that is to be formed into the dished shape;
- a female die element which has grooves that are oriented along meridians of a second pleating area and which are complementary to the ribs;
- the ribs and the grooves of the male and female die elements being only within the first and second pleating areas, respectively;
- and
- wherein of the set of ribs and the set of grooves, one set is in a generally fixed position on its respective die element and the other set is mounted so that it can be retracted relative to its respective die element during mating of the die elements, as the pleats are formed, in a sequential manner such that pleating is carried out in distinct portions of the sheet material sequentially;
- and
- resilient means for opposing retraction of said other set.
4 more elements
Dependencies are inferred from the claim text.