Patent Application
20050161164
This invention relates to a tamping labeler and to a labeling apparatus having tamping labelers.
Products to be sold are commonly labelled. In this regard, automatic labelling apparatus may be employed where the products are smaller and processed in large volumes. One approach in this regard is to wipe a label onto each product as its passes a labelling head. This approach, however, is only well suited for labelling products of uniform dimensions. Where products have irregular dimensions, such that the distance between a given product and the labelling head will vary, tamping labellers are typically used. U.S. Pat. No. 5,829,351 to Anderson discloses such a labeller. In Anderson, a turret carries a number of flexible pneumatic bellows about its periphery. The turret has a vacuum plenum and a positive pressure plenum. The turret rotates each bellows, consecutively, to a labelling station. A bellows normally communicates with the vacuum plenum which keeps it in a retracted position; also, due to end perforations in the bellows, the negative pressure holds a label at the end of the bellows. However, when the bellows reaches the labelling station, it is coupled to the positive pressure plenum which causes a one-way valve to block the perforations and causes the bellows to rapidly extend until it tamps a product below. The force of the tamping forms an adhesive bond between the pressure sensitive adhesive of the label and the product. Labels are fed to each bellows from a label cassette with a label web comprising serially arranged labels on a release tape.
A tamping labeler is suited to the labeling of produce, given the irregular dimensions of produce. However, if the produce is wet, the tamping face of the bellows will also become wet. This can result in the surface tension between the bellows and a label being stronger than the tack adhesion between the produce and the label when the label is tamped against the produce. Should this occur, the label may remain on the bellows. This event may be repeated, such that the bellows may become clogged with a plurality of labels, thereby requiring operator intervention. Even if a bellows does not become clogged, the effectiveness of the labeler is diminished if some labels do not adhere to the produce.
This invention seeks to address this problem.
By providing projections extending outwardly from the base of a wet tamping face of a tamping labeler, which projections maintain at least a substantial portion of a label at a stand off from said base, the surface tension between the label and tamping face is reduced. This reduction in surface tension helps ensure that when a label is tamped against a product, it remains there. The tamping face may be provided with a regular, or irregular, pattern of projections, or with a texture that results in the projections.
According to the present invention, there is provided a tamping labeler for use in a labeling apparatus, comprising: a tamping face having a base and projections projecting outwardly from said base for maintaining at least a substantial portion of a label at a stand off from said base.
According to another aspect of the present invention, there is provided a bellows for use in a labeling apparatus, comprising: a tamping face having a base and projections projecting outwardly from said base for maintaining a label at a stand off from said base.
According to a further aspect of the present invention, there is prvoded a bellows for use in a labeling apparatus, comprising: a tamping face having projections for reducing surface tension between a label held by vacuum to said tamping face and said tamping face when said tamping face is wet.
According to another aspect of the present invention, there is provided a product labeling apparatus, comprising: an indexing turret carrying a plurality of tamping labelers, each tamping labeler having a tamping face with a base and projections projecting outwardly from said base for maintaining at least a substantial portion of a label at a stand off from said base; a vacuum chamber in fluid communication with each tamping labeler other than at a labeling station; a positive pressure chamber in fluid communication with a tamping labeler at said labeling station; a label supply for supplying a label to a tamping face of a tamping labeler at a label supply station spaced from said labeling station.
Other aspects and features of the invention will become apparent by reference to the following description in conjunction with the drawings.
In the figures which illustrate example embodiments of the invention,
Referencing
The turret carries a plurality of bellows 160. Each bellows is fabricated of a flexible material, such as rubber or silicone. The tamping face 162 of each bellows is perforated with holes 164. A one-way valve 166 (
Turret 40 has a stationary core 110 with a port 112 for connection to a vacuum source (not shown) and a port 114 for connection to a source of positive pressure (not shown). The internal configuration of core 110 is such that each bellows is fluidly coupled to port 112 through most of its rotation about core 110 but is instead fluidly coupled to port 114 when a bellows is at the label applying station 128.
Further details of the construction of the labeling apparatus 10 as described so far may be found in WO 02/102669 to Neilsen and Sleiman, published Dec. 27, 2002, the contents of which are incorporated herein by reference.
Turning to
With reference to
The turret 40 is indexed (in direction T) past the label applying station 128 at a time when a product, such as item of produce 180 (being conveyed in direction C), is at the label applying station. As the bellows passes through the label applying station, it is coupled to a source of positive pressure through port 114 (
If the products are wet, the tamping face of the bellows will become wet as-well. In consequence, water will be interposed between fresh labels taken up by the bellows and the tamping face of the bellows. The resulting surface tension must be overcome by the strength of the adhesive bond between the product and the label at the label applying station in order for the label to remain on the product and not on the bellows. The domes 170, by providing a stand-off between the label and the (wet) base 172 of the tamping face 162 of the bellows, reduce this surface tension so that the labels will remain adhered to products. It will be apparent that, if necessary, the height of the domes could be increased to ensure this result.
It may be possible to provide a (regular or irregular) pattern of domes such that only a substantial portion of a label was maintained at a stand-off from the base of a tamping face of a bellows. In such instance, the surface tension between the label and bellows would be increased, but provided it were insufficient to overcome the tack adhesion of the label to the product, this would not be problematic.
With reference to
With reference to
As a further alternative, the tamping face may textured such that the texture results in the projections.
While the tamping labeler described in conjunction with the invention is a bellows, it will be appreciated that the teachings of this invention may be applied to any other type of tamping labeler that is used in a wet environment. For example, this invention has application to a tamping labeler which is in the nature of a spring biased piston, as described in U.S. Pat. No. 5,645,680 to Rietheimer. In Rietheimer, the piston is released by a cam so that it extends under the force of the spring to tamp a product at a label applying station.
Other modifications will be apparent to those skilled in the art and, therefore, the invention is defined in the claims.
