Labelling machine and a method for applying tubular labels to respective articles

摘要

A labeling machine for applying tubular labels to articles; the machine comprises a conveying device movable along a given path and at least one unit to receive and retain an article to be labelled, a feeder to feed a label to the unit, a former to bend the label in a vertical tubular configuration with opposite vertical edges overlapping one another, and at least one welding device arranged on the conveying device to weld the overlapped edges of the label; the welding device comprises an electrically heatable sealing element, provided with a striplike working surface having a height at least equal to the height of the label overlapped edges to be welded, electrical power supplying means selectively connectable to the sealing element and controlled for heating the sealing element along a given portion of the mentioned path and for cooling the sealing element along a subsequent portion of the path, and actuator displacing the sealing element to and from the overlapped edges of the label along a horizontal direction transverse to the path.

主权项

1. A tubular label applicator for applying a label to an article, the applicator comprising:
a conveying device movable along a path, the conveying device having at east one receiving unit configured to receive and retain the article to be labeled; a feeder configured to provide the label to the receiving unit; a winding body configured to bend the label into a tubular configuration with an axis of the winding body transverse to the path, and with opposite edges of the label parallel to the axis such that the opposite edges overlap, the winding body being movable between a retracted position within a support mount and a raised position; at least one transformer associated with the conveying device; and at least one welding device arranged on the conveying device to weld the overlapping opposite edges of the label; the at least one welding device includes:
an electrically heatable sealing element moveable along the path, wherein the sealing element has a working surface strip oriented in a direction parallel to the axis, a longitudinal support body, a heating layer covering a surface of the support body, and an electrical conductor selectively connectable to an electrical power supply and interposed between the support body and the heating layer, the working surface strip having a height at least substantially the same height as the label bent by the winding body when the winding body is positioned in the raised position, the support body internally defining a cooling conduit used for cooling the sealing element;the electrical power supply including the at least one transformer, the at least one transformer being selectively connectable to the sealing element and at least one other sealing element associated with a separate welding device, and wherein the at least one transformer is controlled by a control unit based on feedback signals received from the sealing element, the control unit being configured to connect the at least one transformer to the sealing element for a first predetermined period of time in order to heat the sealing element along a portion of the path for the first predetermined period of time, and to cool the sealing element along a subsequent portion of the path for a second predetermined period of time, such that the sealing element and the at least one other seal element are not heated simultaneously based on their respective positions along the path;an actuator operable to displace the sealing element, along a direction transverse to the path and the axis, between a first position proximate the overlapped edges of the label and a second position apart from the label, the actuator including a movable member that is selectively displaced along the direction; andfirst and second springs for coupling the moveable member to the sealing element and to allow a degree of movement of the sealing element along the direction when the sealing element is displaced to the first position, such that the first and second springs allow the working surface and the axis of the winding body to be substantially parallel in the first position, each of the first and second springs having an axis substantially parallel to the direction, wherein the first spring couples an upper portion of the moveable member to an upper portion of the sealing element, and the second spring couples a lower portion of the moveable member to a lower portion of the sealing element.