APPARATUS FOR APPLYING LABELS TO MOVING ARTICLES

Abstract: The apparatus applies adhesive labels to the rear of articles A, B, C... on a moving conveyor (3). Two arms L,R are mounted on a gantry (2) spanning the conveyer (3). Each arm has an inner arm portion (15) mounted on a shaft (6) which is rotated by a motor (9) and transmission, always in the same direction, under the control of a computer having an input from a sensor (55) for detecting the rear edge of each article. Each arm has an outer arm portion (17) pivoted to the inner arm and urged to a straight position by a torsion spring (19). Each outer arm (17) carried a label-applying pad (33) and is extended by an actuator to collect a label from a printer above the gantry and then retracted, to clear the printer, as the arm rotates, in response to detection of a package, to apply its label to the package.

Description: Apparatus for Applying Labels to Moving Articles This invention relates to apparatus for applying adhesive- carrying labels to articles which are moved past the apparatus for example on a moving conveyor. Apparatus according to the present invention comprises an arm mounted for rotation about an axis transverse to the direction of movement of the said articles, a label support on the arm for releasably supporting a label and carrying the label along a path to bring the label into contact with an article to be labelled, the label support being yieldably mounted relative to the inner part of the arm. Advantageously, the arm is articulated with a resilient bias towards a straight configuration but resiliently yieldable when applying a label to an article. Advantageously, the labels are self-adhesive labels carried by a release tape at a supply point which may include a printer for printing required indicia on the labels. The arm is then preferably extendible and has means for extending the label support to collect a label at the supply point and then to retract the label support clear of the supply point. The extending means may comprise a pneumatic actuator supplied through rotary joints on the axis of rotation of the arm. The apparatus may include two arms mounted for rotation about a common axis and arranged to alternate in collecting and applying labels. In order to reduce the number of rotary air-supply joints required, each arm may carry a two-position pilot valve, the state of which may be changed by the supply of pressurised air, via a respective rotary joint, this supply being also connected by a flexible conduit to a part of the pilot valve on the other arm, the arrangement being such that when both supplies are pressurised, both label supports are retracted, but when one supply is depressurised, the associated pilot valve operates to apply pressure from the other supply to extend the label support associated with the said one supply means. Preferably, the or each label support holds successive labels by suction (applied via a rotary connection at the axis of rotation of the respective arm) , which is released or replaced by positive pressure as the label is applied to an article. An embodiment of the invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 is a vertical elevational view of labelling apparatus in accordance with the invention mounted about a conveyor, as seen from one side of the conveyor; Figure 2 is a vertical section on the line II-II of figure 1; Figure 3 shows one arm of the apparatus on an enlarged scale, in side elevation; Figure 4 is a sectional view on the line IV-IV of figure 3; Figure 5 is an end-view of the arm in the direction of the arrows V-V of figure 3 ; Figures 6a to 61 show 12 successive positions adopted by the arms of the apparatus during a cycle of collecting a label and applying it to a package; and Figure 7 shows diagrammatically the electrical and pneumatic surfaces of the apparatus. As shown in figures 1 and 2, the labelling apparatus 1 is mounted on a gantry frame 2 spanning a conveyor 3 along which successive packages A, B, C, for example from a packaging machine (not shown) are being moved under the apparatus 1. The packages A, B, C have substantially the same dimensions but are not necessarily spaced at equal intervals along the conveyor. The apparatus comprises two substantially identical arms L and R capable of being rotated about a common horizontal axis 4 indefinitely but at variable speeds. The apparatus 1 comprises two articulated arms L, R which are mounted on respective shafts 6 supported in bearings 7 in a gearbox housing 8 for each arm. Each shaft 6 is driven, always in the same direction but at variable speed, by a brushless DC motor 9 (figure 3) via a toothed belt and pulley reduction transmission 10 and a worm shaft 11 the worm 12 of which meshes with a worm wheel 13 secured to the shaft 6. Each arm L, R is formed by an inner arm portion 15, the outer end part of which carries a bolt 16 on which an outer arm portion 17 is mounted by bearings 18. A coiled torsion spring 19 has one end 20 anchored in the inner arm portion 15 and its other end anchored in the outer arm portion 17 and is prestressed to urge the outer arm portion 17 to the position, relative to the inner arm portion 15, shown in figure 3, but to allow relative movement of the outer arm portion 17 in the direction of the arrow 22 in figure 3. The outer arm portion 17 is extendible and for this purpose has a rectangular-section portion 23 on which a head portion 24 is slidable, having a correspondingly shaped space 25 within it. Movement of the head 25 is effective by a pneumatic actuator 26 within the portion 23 and having pneumatic connections 27 and 28 leading to opposite sides of the piston 29 of the actuator. The head 24 carries a bolt 30 on which can swivel, by means of bearings 31, a label support 32 having a label-carrying pad 33 formed by a perforated or porous plastic plate to which suction can be applied from a flexible line 34. Between the hub of the inner arm portion 15 and the casing of the gearbox 8, the shaft 6 passes through a double rotary connector 36, 37 comprising three rotary seals, the two spaces between adjacent seals being connected respectively to a suction line 38 and an actuator supply line 39. Passages 40, 41 within the shaft 6 lead from openings communicating with the two respective spaces between the seals, to the line 34 and to a connector 42 on the inner arm portion 15. The connector 42 is connected both to a line 43 leading to the control port of an air pilot valve 44 (figure 7) and to a port 45 of the air pilot valve 44 of the other arm. During most of the revolution of an arm, a central controller 50 operates an assembly of solenoid operated valves 51 to control the supply of air from a compressed air inlet 52 so that both lines 43L and 43R are pressurised. The valves 44L and 44R then provide the connections shown in figure 7 so that both actuators 26 are retracted. When, however, one of the label supports is to collect a label from a printer 53 or 54 the controller 50 causes the relevant valve in the valve block 51 to depressurise the supply for example in the line 43L. The condition of the valve 44L then changes so that pressure is supplied from the line 43R to the connection 27L to cause the actuator 26L to extend the pad 33L (figure 6a) . Thereafter, the controller 50 causes air pressure to be resupplied to the line 43L causes the valve 44L to vent the port 27L and repressurise the port 28L to retract the pad 32L (figures 6b to 6d) . Operation of the printers 53 or 54 and the valves 51 as well as speed control of the motors 9 is controlled by the controller 50 in response to photoelectric sensors 55 which register and identify the trailing edge of each package A, B, C as it passes. When the arm L reaches the positions shown in figure 6k and 61, the label carried by the pad 32 is brought into contact firmly with the rear surface of the package B and the motor 7L is caused to supply sufficient torque to flex the arm L and, also, if the package is somewhat skew on the conveyor, to turn the pad 32 in flat engagement with the package about the bolt 30 against the action of a helical torsion spring 60. When the package to which the label has just been applied as shown at B for the arm R, moves away from the pad 32, as shown in figures 6b to d, the outer arm 17 can return from the position shown in broken lines in figure 3 to the position shown in solid lines. To prevent excessive shock, a dashpot-type damper 62 is preferably mounted on the inner arm 15. Suction for each of the pads 33 L, R is created by a venturi 71 through which air is blown via a line 72 from one of the valves in the block 51. To release a label, further air is supplied, through a line 73 from another of the valves in the block 51, to the opposite end of the venturi. An air knife 74 may be used to assist the suction pads in removing labels from the printe (s) 53, 54.

Claims: Claims 1. Apparatus for applying adhesive-carrying labels to articles which are moved past the apparatus for example on a moving conveyor, comprising an arm mounted for unlimited rotation about an axis transverse to the direction of movement of the said articles, a label support on the arm for releasably supporting a label and carrying the label along a path to bring the label into contact with an article to be labelled, the label support being yieldably mounted relative to the inner part of the arm. 2. Apparatus according to claim 1, wherein the arm is articulated with a resilient bias towards a straight configuration but resiliently yieldable when applying a label to an articled 3. Apparatus according to claim 1 or 2 for use with self- adhesive labels carried by a release tape at a supply point wherein the arm is extendible and has means for extending the label support to collect a label at the supply point and then to retract the label support clear of the supply point. 4. Apparatus according to claim 3, wherein the apparatus includes a printer adjacent the supply point for printing indicia on the labels. 5. Apparatus according to claim 3 or 4, wherein the extending means comprises a pneumatic actuator supplied through rotary joints on the axis of rotation of the arm. 6. Apparatus according to any preceding claim, wherein the apparatus includes two arms mounted for rotation about a common axis and arranged to alternate in collecting and applying labels . 7. Apparatus according to claim 6, wherein each arm carries a two-position pilot valve, the state of which may be changed by the supply of pressurised air, via a respective rotary joint, this supply being also connected by a flexible conduit to a part of the pilot valve on the other arm, the arrangement being such that when both supplies are pressurised, both label supports are retracted, but when one supply is depressurised, the associated pilot valve operates to apply pressure from the other supply to extend the label support associated with the said one supply means. 8. Apparatus according to any preceding claim, wherein the or each label support holds successive labels by suction applied via a rotary connection at the axis of rotation of the respective arm, which is released or replaced by positive pressure as the label is applied to an article.

Inventors: JONES TIMOTHY JOHN, JONES, TIMOTHY, JOHN
Applicants: JONES TIMOTHY JOHN, LABFAX SYSTEMS LTD, JONES, TIMOTHY, JOHN, LABFAX SYSTEMS LIMITED
Application year: 1995
Main classification: B65C9
IPC codes: B65C1, B65C9