System and method for removing incorrect labels from a web of labels

An incorrect label removal system is disclosed for removing unwanted labels from a web of labels in a labeling machine. The incorrect label removal system includes a label peel assembly positioned between two fixed points along the direction of travel of the web of labels. The label peel assembly provides a first orientation in which labels remain on the web as the web passes the label peel assembly, and selectively provides a second orientation in which labels are removed from the web. The label peel assembly provides that a length of the web between the two fixed points is substantially the same when the label peel assembly is in each of the first orientation and the second orientation.

BACKGROUND

The invention relates to labeling machines in which labels are continuously or intermittently transferred from a web to articles, and relates in particular to labeling machines in which labels are checked and, if necessary, redirected so that unwanted labels are not applied to articles.

For example, U.S. Pat. No. 3,772,123 discloses a label reject mechanism for a labeling machine that includes a pinch wheel on an actuated arm that selectively engages incorrect labels between the pinch wheel and a rotating wheel, preventing them from being applied to a vacuum actuator drum.

U.S. Pat. No. 5,405,482 discloses a labeling machine that includes a label scanning unit for scanning labels on a web, as well as a label removal unit that includes a single freely rotating roller. If an incorrect label is detected by the label scanning unit, then the incorrect label is removed from a rotating label applicator drum by having the label removal unit advance the roller into contact with the adhesive side of the incorrect label on the applicator drum. The incorrect label would then be removed from the roller.

U.S. Pat. No. 6,841,018 also discloses a labeling machine including a label reconciliation device that selectively advances actuating arm that terminates in a roller toward incorrect labels while on a vacuum drum7. The reconciliation device further includes a reject label web onto which rejected labels are applied so that they are removed from the label application assembly.

U.S. Pat. No. 6,450,227 discloses a labeling machine that includes a label check station having an actuator for moving a casing from a rest position that does not interrupt the normal direction of flow of a web of labels to a working position that changes the direction of flow of the web of labels so that the incorrect label may be directed off of the web and onto a rotating reject label core.

Conventional label reject systems, however, generally either remove labels from an applicator drum, or change the direction of travel of a web prior to reaching an applicator stage. Changing the direction of travel of a web to remove labels typically changes the path length of web in order to remove the rejected label from the web. Even small changes in a path length, however, can adversely affect the performance of a labeling machine that relies on high speeds and precision timing.

There is a need, therefore, for an improved label removal system that more efficiently and effectively removes labels from a web.

SUMMARY

The invention provides an incorrect label removal system for removing unwanted labels from a web of labels in a labeling machine. In accordance with an embodiment, the incorrect label removal system includes a label peel assembly positioned between two fixed points along the direction of travel of the web of labels. The label peel assembly provides a first orientation in which labels remain on the web as the web passes the label peel assembly, and selectively provides a second orientation in which labels are removed from the web. The label peel assembly provides that a length of the web between the two fixed points is substantially the same when the label peel assembly is in each of the first orientation and the second orientation.

In accordance with another embodiment, the incorrect label removal system includes a pair of idler rollers, and a label peel assembly a positioned between the pair of idler rollers such that a web of labels passes between and in contact with each of the pair of idler rollers and the label peel assembly. The label peel assembly provides a first orientation in which labels remain on the web as the web passes the label peel assembly, and selectively provide a second orientation in which labels are removed from the web. A distance between the pair of idler rollers remains constant when the label peel assembly is in each of the first orientation and the second orientation. A path length of the web between the pair of idler rollers remains substantially constant when the label peel assembly is in each of the first orientation and the second orientation.

In accordance with a further embodiment, the invention provides a method of removing unwanted labels from a label web in a labeling machine. The method includes the steps of causing a web of labels to travel a first distance through a label removal assembly that includes a pair of idler rollers and a peel roll with the labels remaining in the web while the peel roll is maintained in a first orientation, detecting an incorrect label on the web of labels in advance of the label removal assembly and providing a detection signal, and changing the orientation of the peel roll to a second orientation response to the detection signal such that the incorrect label is separated from the web of labels when the web of labels passes the peel roll such that the web travels a second distance through the label removal assembly that is substantially the same as the first distance.

The drawings are shown for illustrative purposes only.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

A labeling machine in accordance with an embodiment of the invention includes a reject label system as shown inFIG. 1that includes a web10, a first sensor12, peel roll14, a pair of idler rollers16,18and a vacuum spindle20for receiving labels that have been identified as being incorrect. The system also includes a reject label drum22for receiving a reject label web24. The reject label web24is unwound from a reject label supply roll26to the drum22around idle rollers28and30, and the idler roller28is mounted on a spring biased dancer arm32that maintains a desired tension in the reject label web as it advances from the supply roll26to the drum22.

As further shown inFIG. 2, during normal operation, the web10carries labels past the rollers16and18while the peel roll remains in a fixed position. The label side of the web is adjacent the rollers16and18, while the non-label side of the web travels along the peel roll14without causing the labels to become separated from the web.

When an incorrect label is detected by one or more sensors, such as sensor12, the peel roll14is rotated 45 degrees, which causes a peel edge rod element36on the peel roll14to be positioned opposite the vacuum spindle20as shown inFIG. 3. The peel roll14now causes the adjacent incorrect label35to be peeled from the web, and a leading edge of the incorrect label35is transferred to the vacuum drum20. The second sensor34verifies that the incorrect label has been received by the drum20as the label travels toward the drum22as shown at C. The drum20and web24may run continuously or may be moved responsive to the detection of an incorrect label in various embodiments.

As further shown inFIGS. 4 and 5, the roll14includes the rod element36and a shaft38. The rod element36is received within a recess40in the shaft38such that a portion of the rod element protrudes from the circumferential surface of the shaft38. The rod element36may have a diameter, for example, that is about 7 times smaller than the diameter of the shaft38. In further embodiments, the peel roll14may be formed of a unitary structure, for example, by molding or machining. The peel roll14may be formed of any of metal, ceramic or thermoplastic materials.

The system further provides that the web path length between arbitrary fixed points A and B as shown inFIGS. 2 and 3remains the same length when the roll14is rotated between the positions shown inFIGS. 2 and 3. This is achieved by providing that the roll14is mounted on an off-center shaft. In particular, and as shown inFIGS. 6 and 7, the shaft38includes mounting posts42and46that are coupled to bases44and48respectively on either end of the shaft38. The posts42,46and bases44,48are not, however, centered on the shaft38, but rather are slightly offset by, for example, a distance D in one direction and a distance E in a perpendicular direction as shown inFIGS. 6 and 7.FIGS. 8 and 9show top and bottom end views of the rod element36.

As shown inFIGS. 10-12, a system in accordance with a further embodiment of the invention includes a web50of labels that travels between idler rollers52and54, and over peel roll56. Incorrect labels are transferred to a vacuum drum58when the peel roll56is rotated such that a small radius portion of the roll56is positioned opposite the drum58as shown inFIG. 12. The length of the web50between points F and G as it passes over the roll56remains constant when the roll56is moved from the normal position (shown inFIG. 11) the label reject position (shown inFIG. 12).

Incorrect labels are identified by a sensor that is positioned near the web50in advance of the system shown inFIG. 10. A sensor60may be employed to confirm transfer to the drum of the incorrect labels as shown inFIGS. 11 and 12. A reject label web62is arranged to be drawn from a supply roll64via roller68and rollers70and72that are mounted in dancer arms74and76respectively.

In further embodiments, the label reject system may accommodate for different lengths of labels by providing a plurality of peel rolls along the web or by providing that the label reject system may be adjusted. In further embodiments, the peel roll may be formed of a solid piece of material or of a combination of component parts.

Those skilled in the art will appreciate that numerous modifications and variation may be made to the above disclosed embodiments without departing from the spirit and scope of the invention.