Method and device for pressing and pleating overcapping caps of the foil type onto bottle necks

A device for pressing and pleating an overcapping foil cap on a bottle neck, comprising:

• a rigid encompassing frame;
• means defining first and second pairs of diametrically opposed pressure expandable chambers disposed within said frame and arranged to define a central passage for receiving a bottle neck, each of said chambers comprising at least an inner expandable resilient wall defining, integral therewith, a pad having an operative surface defining partially said central passage and shaped, in a rest condition, to substantially correspond to the partial shape in longitudinal and transversal directions of a bottle neck;
• a first means for admitting simultaneously pressurized fluid into the chambers of said first pair for pressing the pads thereof onto the bottle neck;
• a second means, independent of said first means, for admitting simultaneously pressurized fluid into the chambers of said second pair for pressing the pads thereof onto the bottle neck,
• the pads of said first pair having, in transversal cross-section, a substantially constant thickness along their operative surfaces which is delineated laterally by substantially angular edges to initiate pleat formation in a cap when pressed onto a bottle neck,
• the pads of said second pair having, in transversal cross-section, a middle portion having a thickness along their operative surfaces less than that of the opposite lateral end portions thereof which delineate their operative surfaces, whereby said lateral end portions may expandably circumferentially overlap the area of a bottle neck pressed by the pads of said first pair when the pads of said second pair are pressed onto said bottle neck with the pads of said first pair separated therefrom so as to lap the pleats previously formed in said caps by the pads of said first pair.