IMPROVEMENTS IN OR RELATING TO LABEL APPLYING DEVICES FOR APPLYING ADHESIVE LABELS TO ARTICLES

Abstract: The disclosure relates to a labelling mechanism for a weigh/price labelling apparatus comprising a device (10) which supplies printed self-adhesive labels on a backing strip (11) around a stripper block (12) to feed labels onto a temporary holder (13) on which a label is held by vacuum ports in the holder. A label transfer device (16) comprises a carrier (17) mounted for rotary movement on an eccentric drive mechanism (18). Rotation of the drive mechanism moves the carrier (17) from a label receiving position adjacent the holder (13) to a label delivery position for delivering a label to an article. The carrier includes a pad (42) having ports (47) to which vacuum or air pressure can be supplied to hold a label to or discharge a label from the pad. In order to reorientate the label between the pick-up and discharge positions, the pad is mounted on a spindle (43) which is reciprocated in opposite directions by means of two pneumatically operatable piston/rack members (46) movable in bores (45) in the mounting block for the pads. The stroke of the pistons can be adjusted so that the pad can be orientated as required to suit the article to which the label is to be applied.

Description: This invention relates to label applying devices for applying adhesive labels to articles and is particularly, although not exclusively applicable to label applying devices for labelling apparatus of weigh/price labelling machines in which articles (usually food items) are delivered by a conveyor to a weigh station where they are weighed and then to a labelling station where a label printed with the weight and price computed from the measured weight and other information such as date dates, goods description and appropriate bar codes is applied to the article. This invention provides a label applying device for applying adhesive labels to articles comprising; label holding means, means to supply labels one-by-one to the holding means oriented in one direction, a pad having a surface to receive a label, means to draw vacuum at the surface to hold a label on the surface and means to apply air pressure to the surface to propel the label from the pad onto a surface of an article, reciprocating means to support the pad and to move the pad from a position adjacent the label holding means to receive a label and a label discharge position to discharge a label onto an article and means to rotate the pad with respect to the supporting means through a predetermined angle about an axis extending normal to the surface of the pad to enable a label received from the holding means to be positioned in the required orientation on said article. Said reciprocating means which supports and moves the pad between the label receiving position and the label discharging position may be arranged to maintain the pad in a horizontal attitude throughout said movement. In one arrangement according to the invention the pad may be mounted at one end of a spindle rotatably mounted on the supporting means, and a pair of pneumatically operated racks may be mounted in the supporting means in driving engagement with a pinion on the spindle to rotate the spindle and with it the pad in opposite directions. In any of the above arrangements the pad rotating means may be arranged to rotate the pad through an angle of 90° in one or other direction. Also in any of the above arrangements means may be provided for adjusting the angle through which the pad is rotated between said respective receiving and discharge positions. For example the means for adjusting the angle of rotation of the pad comprise stop means for limiting the rotation of the pad in at least one direction. More particularly the stop means may be associated with the means for rotating the pad and may comprise adjustable screw means mounted on the pad supporting means and in the path of the pad rotating means to limit the angles through which the pad rotating means rotates the pad. Thus in the case where the pad rotating means comprises a pair of pneumatically operated racks mounted in the pad spindle means, the adjustable screw means may comprise a pair of screws mounted in the carrier in the paths of of movement of the racks to provide end stops for limiting the movement of the racks and thereby the rotation of the pad. Specifically, the pad rotating means may be arranged to rotate the pad through an angle of 90° in one or other direction. The following is a specific description of a specific embodiment of the invention, reference being made to the accompanying drawings in which: FIGURE 1 is an elevation view of part of a label applying mechanism in a weigh/price labelling machine including a movable label applying head; FIGURE 2 is an exploded view of the components of the label applying head; FIGURE 3 is a side view of the label applying head; and FIGURE 4 is a section on the line 4-4 of FIGURE 3. Referring firstly to Figure 1 of the drawings, there is shown a part of a labelling mechanism for a weigh/price labelling apparatus comprising a device 10 which supplies printed self-adhesive labels on a backing strip 11. A stripper block 12 is provided around which the backing strip passes at an acute angle feeding the labels onto a temporary holder 13 for the label formed by a pair of spaced vertically extending parallel walls 14. The walls 14 terminate in downwardly facing edges 15 located immediately above the end of the stripper block 12 so that as a label is detached from the backing, it slides onto the edges 15. The edges 15 have spaced vacuum ports along the length thereof to hold temporarily the label to the edges. A label transfer device is indicated at 16 and comprises a carrier 17 mounted for rotary movement on an eccentric drive mechanism indicated at 18. Rotation of the drive mechanism moves the carrier 17 from the label delivery position indicated in Figure 1 through an annular path which extends downwardly between the walls 14 for the carrier to pick up a label supported at the lower ends thereof and thence downwardly to the label discharge position shown in Figure 1. The eccentric drive mechanism is mounted on a bracket 20 and comprises a first shaft 21 mounted in bearings 22 and 23 and driven by an electric motor 24 through a belt drive 25. The shaft 21 extends through a fixed hub 26 to which a toothed wheel 27 is keyed. An eccentrically extending housing 29 is keyed to the shaft 21 and an eccentric shaft 30 is mounted in the housing in a bearing 31. A toothed wheel is keyed to the shaft 30 and is drivably connected to fixed toothed pinion 27 by a drive belt 28 at one end of the shaft 30 and the other end of the shaft is keyed to the carrier 17. Thus, rotation of the shaft 21 by the motor 24 rotates the carrier 17 through a circular path whilst maintaining a constant horizontal attitude. The carrier 17 is formed with a recess 40 in which a rectangular block 41 is mounted. A pad 42 for receiving and applying labels to articles to be labelled is mounted at one end of a spindle 43 extending downwardly from the block. The spindle is supported in bearings 44 in the block for rotation about a vertical axis. The block has two parallel cylindrical bores 45 in which integral pistons/rack members 46 are reciprocatable. The rack/piston members engage either side of a toothed pinion 47 keyed to the spindle 43 which extends between the cylinders. The cylinders 45 are closed at one end of the carrier block 41 by an airplate 48 and at the other end by adjustable sealed plugs 49 as shown in Figure 4. Air pressure is supplied to one or other of the cylinders 45 through ports 47 on the carrier 17 and appropriate passageways through the carrier to drive one or other pistons/racks to the end of its travel adjacent the plate 48 to reciprocate the spindle 43 and thereby the pad 42 in one or other direction. The extent of reciprocation can be adjusted by adjusting the end plug. In the particular arrangement shown, rotation of 90° is provided for the pad 42. A further port 50 is provided on the carrier for supplying air pressure to the pad 42 through passageways to the carrier and the spindle 43 to the pad surface to provide vacuum at the pad to hold the label to the pad or air pressure to the surface of the pad to discharge a label from the pad onto an article below the pad. In operation, the reciprocating carrier rotates through the parallel walls 14 to collect a label supplied from the backing 11 and collects the label, vacuum being applied to the pad at that time. As the pad moves away from the walls, air pressure is supplied to one of the cylinders 46 to cause the pad to rotate through 90° to reorientate the pad for application of the label to an article. By the time the carrier reaches the label applying position, the 90° movement will have been completed. The vacuum is then cut off from the pad and a pressure pulse is supplied to the pad to discharge the label onto an article. Thus the label is reorientated from the attitude in which it has been collected from the temporary holder 13. As the carrier continues to move back towards the temporary holder, air pressure is supplied to the other cylinder of the block to return the pad to its original orientation. It will be appreciated that the pad can be arranged to rotate in either direction and although the arrangement described above provides 90° of rotation, the extent of rotation can readily be set by appropriately designing the ram operated racks and pinion engaged therewith. It will also be appreciated that the pad can be operated selectively, that is it is not rotated if the label is received from the temporary holder correctly oriented to be applied to an article.

Claims: 1. A label applying device for applying adhesive labels to articles comprising; label holding means, means to supply labels one-by-one to the holding means oriented in one direction, a pad having a surface to receive a label, means to draw vacuum at the surface to hold a label on the surface and means to apply air pressure to the surface to propel the label from the pad onto a surface of an article, reciprocating means to support the pad and to move the pad from a position adjacent the label holding means to receive a label and a label discharge position to discharge a label onto an article and means to rotate the pad with respect to the supporting means through a predetermined angle about an axis extending normal to the surface of the pad to enable a label received from the holding means to be positioned in the required orientation on said article. 2. A labelling device as claimed in Claim 1, wherein said reciprocating means which supports and moves the pad between the label receiving position and the label discharging position maintains the pad in a horizontal attitude throughout said movement. 3. A label applying device as claimed in Claim 1 or Claim 2, wherein the pad is mounted at one end of a spindle rotatably mounted on the supporting means, and a pair of pneumatically operated racks are mounted in the supporting means in driving engagement with a pinion on the spindle to rotate the spindle and with it the pad in opposite directions. 4. A label applying device as claimed in any of the preceding claims, wherein the pad rotating means is arranged to rotate the pad through an angle of 90° in one or other direction. 5. A label applying device as claimed in any of the preceding claims, wherein means are provided for adjusting the angle through which the pad is rotated between said respective receiving and discharge positions. 6. A label applying means as claimed in Claim 5, wherein the means for adjusting the angle of rotation of the pad comprise stop means for limiting the rotation of the pad in at least one direction. 7. A label applying device as claimed in Claim 6, wherein the stop means is associated with the means for rotating the pad and comprise adjustable screw means mounted on the pad supporting means and in the path of the pad rotating means to limit the angles through which the pad rotating means rotates the pad. 8. A label applying device as claimed in Claim 7, and in the case where the pad rotating means comprise a pair of pneumatically operated racks mounted in the pad spindle means, wherein the adjustable screw means comprise a pair of screws mounted in the carrier in the paths of of movement of the racks to provide end stops for limiting the movement of the racks and thereby the rotation of the pad.

Inventors: EAGLE, CHRISTOPHER RAYMOND
Applicants: PORTALS ENGINEERING LIMITED
Application year: 1988
Main classification: B65C9
IPC codes: B65C9