It is a requirement of the fiscal authorities in some markets that all packets of cigarettes offered for sale must bear a tax or revenue stamp. Such stamps are adhesively secured to an exterior surface (s) of cigarette packets following upon the cigarettes having been packaged in the packets.

As used hereinafter the term"label"is used to embrace tax and revenue stamps, labels or any similar sheet like item applied to the exterior of a packet.

When on a packing machine adhesive labels are fed to a label application station, at which a label is applied to each packet fed to the station, it sometimes occurs that two, or indeed more, labels, one above the other, are fed together to the station and are applied to a package. If the labels take the form of tax stamps, each-such unintended application of two or more stamps rather than one stamp constitutes a financial loss.

It is also sometimes the case that when a label is applied to a package on a packing machine the adhesion of the label to the package is insufficient to prevent the label becoming separated from the package during subsequent handling of the package. If the label is a tax stamp, a package may thus enter the marketplace without a tax stamp this being in contravention of the requirements of the law.

It is an object of the subject invention to provide a label monitoring device operable to overcome these problems of prior art label application.

The subject invention provides a label monitoring device operable to monitor labels which have been applied to packets, said device comprising conveyance means operable to move packets serially to a monitoring station of said device, suction means, transfer means and label receiving and retaining means, said suction means being operable to apply suction to a label of a packet at said station thus to capture the label from the packet if the label is inadequately adhered to the packet and said transfer means being operable to transfer a thus captured label to said receiving and retaining means.

A label captured from a packet by the suction means may be the upper label of two labels applied to the packet one above the other, leaving, after the capture, the lower label adhered to the packet. The label may be a plurality of labels, if two or more labels are accidentally applied to the packet.

If a label is insufficiently securely adhered to a packet upon arrival of the packet at the monitoring station, the suction means will capture the label from the packet. This may be the case even if such insufficiently securely adhered label is the lower label of two or more labels applied one above the other to the packet, so long as the adhesion between the upper and lower labels is greater than the adhesion between the lower label and the packet.

The label or labels captured from a pack is/are retained in the receiving and retaining means. Thus it is possible to re-use such retained labels by re-application to packets.

Such capture, retention and re-use of labels avoids financial loss, especially if the labels are tax stamps.

Advantageously, the transfer means is a rotative means and the transfer path of a captured label from the monitoring station to the label receiving and retaining means is constituted by an arc of the rotative movement of the rotative means. It is convenient for the suction means to be mounted of such rotative transfer means, in which case the suction means may comprise a plurality of suction heads equi-angularly spaced about the rotative transfer means such that each suction head arrives at the monitoring station in register with the arrival thereat of a packet.

The conveyance means of the label monitoring device is conveniently provided by conveyance means of a packing machine on which the monitoring device is mounted. If the label monitoring device is not mounted on a packing machine, but is situated downstream of a packing machine, the conveyance means will be otherwise provided, as for example by being a conveyance means dedicated to the monitoring device.

Advantageously, the conveyance means is operable to move packets to and through the monitoring station in continuous motion and at uniform speed. The speed of the conveyance . means may be directly related in the number of revolutions of the suction wheel per minute and the number of suction heads mounted thereupon. Preferably the conveyance means is operable to move packets to and through the monitoring station at a speed in the range of about 300 to about 900 packets per minute. More preferably the speed is 450 packets per minute.

The receiving and retaining means may advantageously be removable and adapted to be mountable at the label application station to re-supply the removed labels.

In order that the subject invention may be fully understood and readily carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawing depicting a label monitoring device.

In the diagrammatic drawing reference numeral 1 designates a packet, a packet of cigarettes for example, which packet 1 is being conveyed at uniform speed, in the direction of arrow A, by conveyance means (not shown), which conveyance means is provided by conveyance means of a packing machine (also not shown). As depicted, the packet 1 is at a label. monitoring station of the label monitoring device.

Before the serial arrival-of packets, such as depicted packet 1, at the monitoring station, each packet passes through a label application station (not shown) of the aforesaid packing machine. It is the intended purpose of a label application device (also not shown) at the label application station to apply and adhere a label (in the form of a tax stamp) to the uppermost surface of each packet. Upon occasion though, and as hereinabove related, two labels (tax stamps) one above the other, are fed to the application station and are together applied to a packet. The result of such eventuality is depicted in relation to packet 1, reference numeral 2 designating such a"double"label.

Reference numerals 3 and 4 designate respectively a suction wheel and a container of the label monitoring device.

The suction wheel 3 is mounted of mounting means 5, which mounting, means 5 is fixedly secured relative to the aforesaid packing machine. The mounting means 5 provides (by means not shown) rotative motion to the suction wheel 3 in the direction of arrow B, such that the peripheral speed of wheel 3 is the same as the linear speed of packet 1 in the direction of arrow A.

Mounted on the suction wheel 3, at diametrically opposed locations, are first and second suction heads 6 and 7. By means of a passageway (not shown) in the mounting means 5 and passageway means communicating therewith (and also not shown) in the suction wheel 3, suction is applied to a suction head 6,7 in the arc of rotation of the wheel 3 commencing with a suction head 6,7 arriving at the aforesaid label monitoring station and discontinuing upon the arrival of that suction head at the container 4.

As may be discerned from the diagrammatic drawings, a peripheral portion of the suction wheel 3 extends into the interior of the container 4, this being by way of an aperture in the container 4. The container further comprises doctor blade means 8 and a lid 9. The container may be adapted to be removable from its receiving location and be mountable at the label application station.

As will be readily appreciated from the diagrammatic drawing and the foregoing description with reference thereto, suction head 6 captures the upper label of the"double"label 2 and, by way of the rotation wheel 3, the upper label is transferred to the container 4, whereat the suction at the suction head 6 is discontinued and the doctor blade means 8 strips the upper label (designated by reference numeral 2'as shown within the container 4) from the wheel 3.

If in respect of a packet arriving at the label monitoring station a single label which has been applied thereto is insecurely adhered thereto, then in the same manner the label will be captured and transferred to, and deposited in, the container 4. The packet machine comprises, downstream of the label monitoring device, a label detection device (not shown) operable to detect any packet not bearing a label and to remove such packet from the packaging line.

If in respect of a packet arriving at the label monitoring station more than two labels have been applied thereto, then in the same manner one or more labels will be captured and transferred to the container 4, depending on the respective strength of the adherence between labels or labels and packets.

The width of the suction wheel 3 may be less than the width of the labels, so that a label captured on the wheel 3 by a suction head 6,7 extends to each side of the wheel 3, in which case the doctor blade means 8 is comprised of a pair of doctor blades, one to each side of the portion of the wheel 3 which extends into the container 4. Thus when a label carried on the wheel 3 enters the container 4, the doctor blades contact respective margins of the label.

In accordance with an alternative arrangement, the suction wheel 3 comprises a continuous peripheral groove (not shown) and the doctor blade means 8 comprise a single doctor blade which extends partially into the groove.

Labels (tax stamps) deposited in the container 4 may be removed therefrom for re-use.