Vacuum drum for a labeling unit, and labeling unit having a vacuum drum of this type

Abstract

A vacuum drum for container labeling includes vacuum holders for holding a label. Each holder has a bistable rotational switch that switches between operating positions as a result of its switch actuator interacting with stationary switches during the drum's rotation. In one operating position, a label receives glue from a glue station. In the other, the holders avoid engagement with the glue station.

Claims

1. An apparatus comprising a drum for a labelling unit of a labelling machine for labeling containers, said drum being a vacuum drum that comprises a drum surface, said drum surface being a circumferential surface, a drum axis, and a vacuum-holder pair that rotates with said drum about said drum, wherein said vacuum-holder pair comprises front and rear holders provided at said surface and offset relative to one another along said rotation direction, said holders being vacuum holders, wherein said front and rear holders hold corresponding front and rear ends of a label as said label is held against said drum's surface, wherein each of said front and rear holders comprises a rotational switch that can be switched between two operating positions said rotational switch being a bistable switch comprising a switch actuator that causes said rotational switch to switch between said operating positions, wherein said rotational switch, after having been switched into an operating position, remains in said operating position, wherein, said rotational switch switches said front and rear vacuum holders between first and second operating positions, wherein said first operating position is a radially-inner position in which said pair is movable without contact past a gluer that is next to said drum, wherein said second operating position is a radially-outer position in which said vacuum holder pair enables said gluer to apply glue to said label, and wherein said switch actuator engages a stationary switch to initiate a switch between said operating positions.

2. The apparatus of claim 1, wherein said drum further comprises segments arranged around a drum axis, wherein vacuum-holder pair is one of a plurality of vacuum-holder pairs, each of which is one of said segments, wherein said front and rear vacuum holders of each of said vacuum-holder pairs are switchable separately from each other between said operating positions using corresponding rotational switches thereof.

3. The apparatus of claim 1, further comprising a front pad and a rear pad, said pads being vacuum pads, wherein said front pad is disposed at said front holder, wherein said rear pad is disposed at said rear holder, wherein said front pad is configured to switch between said radially-outer position and said radially-inner position by said front holder's rotational switch, and wherein said rear pad is configured such as to be switched between said outer working position and said inner maintenance position by said rear holder's rotational switch.

4. The apparatus of claim 1, wherein said rotational switch comprises a U-shaped carrier, wherein said carrier comprises side limbs, a rotatable pivot axis extending between said side limbs along a direction parallel to said drum axis, and at least two rocker levers arranged along said pivot axis, wherein movement of said rocker levers causes said rotational switch to change state.

5. The apparatus of claim 1, wherein said rotational switch further comprises a punch that is biased by a spring force and that is guided to move axially, wherein said punch has a first end that has a sealed connection with a nozzle body on which a vacuum pad is arranged and a second end that engages a rocker lever.

6. The apparatus of claim 1, wherein said rotational switch further comprises a pivot axis and rocker levers, wherein said rocker levers are arranged at said pivot axis to pivot between said operating positions, wherein each of said rocker levers comprises first and second switching surfaces, wherein said first switching surface engages said pivot axis in said first operating position, and wherein said second switching surface engages said pivot axis in said second operating position.

7. The apparatus of claim 1, wherein said rotational switch comprises rocker levers and vacuum pads, wherein said rocker levers switch between said first and second operating positions, wherein said first operating position results in said vacuum pad being retained in a working position, and wherein said second working position results in said vacuum pad being retained in a maintenance position.

8. The apparatus of claim 1, wherein said rotational switch comprises a pivot axis, a punch, and rocker levers having switching surfaces, wherein said punch moves in a radial direction relative to said drum, wherein movement of said punch engages said switching surfaces to cause said rotational switch to transition between said operating positions, wherein said stationary switch initiates pivoting of said switch actuator to permit said movement of said punch.

9. The apparatus of claim 1, further comprising a base, wherein said switch actuators comprise free ends, wherein said free ends for switch actuators of front and rear holders lie in different horizontal planes at different heights above said base.

10. The apparatus of claim 1, wherein said stationary switch comprises a pivotable lever having a control surface for engaging said actuator to initiate switching of said rotational switch.

11. The apparatus of claim 1, wherein said stationary switch is one of a plurality of stationary switches, wherein each of said stationary switches comprises a pivotable lever having at least one control surface, and wherein at least one of said pivotable levers comprises two control surfaces.

12. The apparatus of claim 1, wherein said stationary switch is configured to use a control surface thereof to press said switch actuator radially inward, thereby initiating transition of said rotational switch into said radially-inner position.

13. The apparatus of claim 1, wherein said rotational switch is a rotational switch of said rear holder, wherein said stationary switch is configured to use a control surface thereof to press said switch actuator of said rotational switch radially inward to initiate transition of said rotational switch into said radially-inner position.

14. The apparatus of claim 1, wherein said stationary switch is one of at least three stationary switches, among which is a third stationary switch having first and second control surfaces, wherein said third stationary switch is configured to press said actuator radially away from said drum axis to initiate transition of said rotational switches into said radially-outer position.

15. The apparatus of claim 1, wherein said switch actuator comprises a bolt.

16. The apparatus of claim 1, further comprising a labeling machine for labeling containers with a roll-fed label, said labeling machine comprising said drum.

17. The apparatus of claim 1, wherein said switch actuator comprises a roller.

18. The apparatus of claim 1, wherein said switch actuator comprises a tag.

19. The apparatus of claim 1, wherein said switch actuator comprises a sleeve.

20. The apparatus of claim 1, wherein said switch actuator comprises a freely-rotating roller.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) These and other features of the invention will be apparent from the following detailed description and the accompanying figures, in which:

(2) FIG. 1 is a view from above a labeling unit of a labeling machine for labeling containers;

(3) FIG. 2 is an isometric view of a vacuum drum used in the labeling machine of FIG. 1;

(4) FIG. 3 shows the drum of FIG. 2 from below;

(5) FIG. 4 is a top view from above a carrier plate of the drum shown in FIG. 3;

(6) FIG. 5 is a side view of the drum shown in FIG. 4;

(7) FIG. 6 is an isometric view of a segment of the drum shown in FIG. 2;

(8) FIG. 7 is a sectional view of the drum shown in FIG. 6;

(9) FIG. 8 is a top view of the segment shown in FIG. 6 with the front vacuum holder in its working position;

(10) FIG. 9 is a top view of the segment shown in FIG. 6 with its front vacuum holder is located in its maintenance position; and

(11) FIG. 10 shows a view from below the vacuum drum of FIG. 2 in which the switch actuators 31.1, 32.2 are configured as switching rollers.

(12) Identical reference numbers are used in the figures for elements of the invention which are the same or have the same effect. Moreover, for easier overview, only reference numbers are shown in the individual Figures which are required for the description of the respective figure. In the figures, also, the invention is only represented in schematic views to explain the mode of operation. In particular, the representations in the figures serve only to explain the underlying principle of the invention. For reasons of easier overview, the representation of all the constituent parts of the device has been avoided.

DETAILED DESCRIPTION

(13) FIG. 1 shows a labeling unit 1 of a labeling machine for the labeling of bottles or similar containers 2 with roll-fed labels 3. The labels 3 are drawn off a supply roll 4 that supplies an endless strip of label material 3a. The labeling unit 1 includes a cutter 5 that cuts the label material 3a into a length that is required for a label 3.

(14) The labeling machine 1 also includes a vacuum drum 6. The vacuum drum 6 transfers the label 3 onto a container 2 as the container is being moved past on a rotor 7 that is moving in a first direction A. Meanwhile, the vacuum drum 6 rotates in a second direction B.

(15) Conveyor rollers draw the label material 3a off the supply roll 4 consistent with the first direction A and convey it to the cutter 5.

(16) The cutter 5 comprises a cutting drum 12, that, during the labeling operation, rotates about its vertical cutting-drum axis TA along a third direction C that is opposite the second direction B.

(17) Rotating plates 8 along the rotor's circumference each support a standing container 2 that is to be labeled. A transporter, which has been omitted for clarity, receives containers 2, such as bottles, from a container inlet and transports them to the rotor 7, where they stand on the rotating plates 8. The rotor 7 moves the containers 2 past the labeling unit 1. The drum 6, which holds a label along a circumferential drum surface thereof with the label having had glue applied thereto, labels the container 2.

(18) The drum 6 carries out the labeling by transferring a leading edge of the label onto the container 2 as the container 2 moves past. The rotating plate 8 then rotates the container 2, thus allowing it to draw the rest of the label from the drum 6. The newly-labeled container 2 then proceeds to a container outlet to be received at another transporter for further processing.

(19) Front and rear holders 9.1, 9.2 form a vacuum-holder pair 9 that holds the edges of the label along the drum's surface during the foregoing operation. Each holders 9.1, 9.2 is a vacuum holder. The holders 9.1, 9.2 are spaced apart from each other along the circumferential direction by the length of the label. Since the drum rotates, one of these holders leads the other. The front holder 9.1 holds the label's leading edge and the rear holder 9.2 holds the label's trailing edge.

(20) The labels 3 are cut and separated from an endless strip of labeling material 3a that has been wound onto a supply coil 4 to be drawn off for further processing as required. Motor-driven conveyor rollers convey this label material 3a to the labeling unit 1 and pass it by the cutting unit 5 to be cut as needed to form a label 3, to be separated from the strip. This label is then transferred to the vacuum drum 6.

(21) Referring to FIG. 7, the front holder 9.1 includes a front rotational switch 30.1 and the rear holder 9.2 includes a rear rotational switch 30.2. Each rotational switch 30.1, 30.2 has a corresponding switch actuator 31.1, 31.2 that causes the rotational switch 30.1, 30.2 to transition between two operating positions BS1, BS2.

(22) Each operating position BS1, BS2 is a fixed stationary operating position. The operating position is “fixed” because the rotational switch 30.1, 30.2 remains in that position until it is switched out of that position. The rotational switch 30.1, 30.2 is thus a bistable switch. The first operating position BS1 corresponds to an inner maintenance position WP and the second operating position BS2 corresponds to an outer working position AP.

(23) In a preferred embodiment, the switch actuator 31.1, 31.2 comprises a component that is rotationally symmetric to an axis along which it extends. A suitable switch actuator 31.1, 31.2 comprises a bolt.

(24) Referring back to FIG. 1, the labeling machine 1 includes a gluing station 11 having a glue roller that applies glue to labels. When the holder 9.1, 9.2 is in its working position AP, the holder pair 9 guides the label, which is being held by suction, against the glue roller at the gluing station 11. As a result, glue can be applied to the label. In contrast, a holder 9.1, 9.2 that is in its maintenance position WP can be led past the gluing station 11 without making contact. This is useful when the holder pair 9 is not carrying a label, for example as a result of a gap in the container flow.

(25) The working position AP is thus the usual configuration during operation. The maintenance position WP, which is located radially inward from the working position AP, is a disengaged position. An empty holder pair 9, which is one that is not carrying a label, is temporarily switched into the maintenance position WP.

(26) In the second fixed operating position BS2 of the rotational switch 30.1, 30.2, the front and rear vacuum holders 9.1, 9.2 are switched into their corresponding working positions AP. As a result, the holders 9.1, 9.2 hold a label 3 and guide it past the gluing station 11 so that the label can receive an application of glue.

(27) As shown in FIG. 2, the drum 6 comprises identical segments 17 arranged around the drum's axis TA. Each segment 17 includes a holder pair 9 having front and rear vacuum holders 9.1, 9.2. The front and rear vacuum holders 9.1, 9.2 switch between the two operating positions BS1, BS2 separately from each other using their corresponding rotational switches 30.1, 30.2.

(28) As can be seen in FIG. 3, each segment 17 comprises a carrier plate 15 that forms a segment of a pitch circle that is centered at a vertical shaft 16 that coincides with the drum's axis TA and is guided through a fixed base 40, as shown in FIG. 2. A motor 18, which is secured to the base's underside, drives the shaft 16, thereby rotating the drum 6 in the second direction B. Embodiments include those in which the motor 18 is an electric motor, such as a servomotor. A wall section 19 forms part of the drum's circumferential wall. The wall section 19 extends between the front and rear holders 9.1, 9.2.

(29) The wall section 19 has suction openings 20 formed therethrough to connect to vacuum chambers 21 that lie radially inward from the wall section 19. Suction lines 22, shown in FIG. 6, couple to a rotary connection and connect the vacuum chambers 21 to a central vacuum source.

(30) Each of the front and rear vacuum holders 9.1, 9.2 includes an associated vacuum pad 35.1, 35.2. The vacuum pad 35.1, 35.2 is a strip that extends in a direction parallel to the drum's axis TA. Openings 10 in the vacuum pad 35.1 permit the ends of the label to be held by suction against the vacuum pad 35.1, 35.2. The vacuum pads 35.1, 35.2, like the holders 9.1, 9.2, switch between the radially-outer working position AP and the radially-inner maintenance position WP. When in the working position AP, the vacuum pads 35.1, 35.2 project radially outward from the wall section 19. This promotes application of glue only to the label's ends when the label is brought to the gluing station 11.

(31) As shown in FIG. 7, the vacuum pads 35.1, 35.2 are hermetically secured to corresponding front and rear nozzle bodies 36.1, 36.2 to ensure a connection between the vacuum openings 10 provided at the respective vacuum pads 35.1, 35.2 and the suction lines 22.

(32) As shown in FIG. 6, the rotational switch 30.1, 30.2 comprises end limbs that extend radially-inward to form a U-shaped carrier. A rotatable pivot axis 33 extends between the side limbs along a direction parallel to the drum axis TA. Two rocker levers 34.1, 34.2 are securely arranged along the pivot axis 33 and spaced apart along the pivot axis 33.

(33) As shown in FIG. 8, each rocker lever 34.1, 34.2 comprises first and second switching surfaces SF1, SF2. Each switching surface SF1, SF2 interacts with a first end of a punch 37 that is biased by spring force. The punch 37 is guided to be displaceable in an axial direction along a side limbs of the U-shaped carrier element 32. The punch's second end connects securely to the corresponding front and rear nozzle bodies 36.1, 36.2.

(34) The rocker levers 34.1, 34.2 pivot to-and-fro between the first and second operating positions BS1, BS2. The first operating position BS1 is formed at the first switching surface SF1 and the second operating position BS2 is formed at the second switching surface SF2 of the rocker levers 34.1, 34.2.

(35) Switching the rocker levers 34.1, 34.2 into the first operating position BS1 holds the front and rear vacuum pads 35.1, 35.2 in the maintenance position WP. Switching the rocker levers 34.1, 34.2 into the second operating position BS2 holds the vacuum pads 35.1, 35.2 in the working position AP.

(36) As shown in FIGS. 6 and 7, a lever 39 couples the pivot axis 33 to the switch element 31.1, 31.2. A stationary switch 41.1, 41.2 is thus able to use the lever 39 to pivot a corresponding switch actuator 31.1, 31.2 to rotate the pivot axis 33. This, in turn, causes the switching surfaces SF1, SF2 at the rocker levers 34.1, 34.2 to switch, thus moving the punch 37 outward or inward. This, in turn, causes a switch between the first and second operating positions BS1, BS2. Moreover, the switch is bistable. After having been switched into a new operating position BS1, BS2, that operating position remains selected until another switching event occurs. The front and rear rotational switches are therefore “self-holding.”

(37) The vacuum drum 6 therefore represents a bistable system that remains in either the inner maintenance position WP or the outer working position AP without the need for the switch actuators 31.1, 31.2 to be held or guided by the switching device 41.1 . . . 41.3. It is therefore only necessary for switching to occur when some change makes switching necessary, such as when gaps occur in the container flow or upon reinstatement of continuous container flow. This reduces the number of switching procedures that would otherwise have to be carried out for large gaps in which many containers are missing.

(38) In some embodiments, as shown in FIG. 7, the distance between the base 40 and a free end of a front switch actuator 31.1 of a front vacuum holder 9.1 differs from the distance between the base 40 and the free end of a rear switch actuator 31.2 of a rear vacuum holder 9.2. In FIG. 7, the free ends of the front switch actuators 31.1 of the associated front vacuum holders 9.1 are in a first horizontal plane that is at a first height H1 above the base 40 and the free ends of the rear switch actuators 31.2 of the rear vacuum holders 9.2 are in a second horizontal plane that is at a second height H2 above the base 40, where the first height exceeds the second height. As a result, the free ends of the front switch actuators 31.1 are above the free ends of the rear switch actuators 31.2.

(39) To initiate switching of the front and/or rear rotational switch 30.1, 30.2 between first and second stationary operating positions BS1, BS2, the respective switch actuators 31.1, 31.2 are be brought into working engagement with at stationary switches 41.1 . . . 41.3, as shown in FIGS. 2 and 4.

(40) As shown in FIG. 4, each stationary switch 41.1 . . . 41.3 comprises a switchable lever 42.1 . . . 42.3 with a control surface 43.1 . . . 43.4. Each control surface 43.1 . . . 43.4 initiates a switching movement of a rotational switch 30.1, 30.2 by way of their respective switch actuators 31.1, 31.2. Each switchable lever 42.1 . . . 42.3 pivots relative to the respective switch actuator 31.1 . . . 31.2 in such a way that its control surface 43.1 . . . 43.4 initiates a switchover movement between operating position BS1, BS2 by interacting with the corresponding rotational switch 30.1, 30.2.

(41) Some embodiments feature first, second, and third stationary switches 41.1, 41.2, 41.3 as shown in FIG. 4. In such embodiments, the first switching device 41.1 comprises a first pivotable lever 42.1 with a first control surface 43.1, the second switching device 41.2 comprises a second pivotable lever 42.2 with a second control surface 43.2, and the third switching device 41.3 comprises a third pivotable lever 42.3 with third and fourth control surfaces 43.3, 43.4. The various pivotable levers 42.1, 42.2, 42.3 pivot independently of each other.

(42) The first stationary switch 41.1 presses the front switch actuator 31.1 of a corresponding front vacuum holder 9.1 radially inward in the direction of the drum's axis TA. This switches the front rotational switch 30.1 into the first operating position BS1, thus placing the front vacuum holder 9.1 into the maintenance position WP. If, by a further rotation about the drum axis TA, the front switch actuator 31.1 now disengages from the first control surface 43.1 of the first switching device 41.1, the front vacuum holder 9.1 holds itself in the first operating position BS1, This places the first control surface 43.1 of the first switching device 41.1 at the first height H1.

(43) The second stationary switch 41.2 presses the rear switch actuator 31.2 radially-inward towards the drum's axis TA, thereby switching the rear rotational switch 30.2 into the first operating position BS1. This places the rear vacuum holder 9.2 is located into its maintenance position WP.

(44) A further rotation about the drum's axis TA disengages the rear switch actuator 31.2 from the second control surface 43.2. The rear vacuum holder 9.2 nevertheless holds itself in the first operating position BS1. The second control surface 43.2 of the second switching device 41.2 is thus at the second height H2.

(45) The third stationary switch 43.1 is configured such that the third and fourth control surfaces 43.4, 43.4 exert a radially-outward force. This causes the front and rear rotational switches 30.1, 30.2 to switch into the second operating position BS2, in which the vacuum holders 9.1, 9.2 are in the working position AP.

(46) As the drum rotates further, the front and rear vacuum holders 9.1, 9.2 disengage from the third and fourth control surface 43.3, 43.4. Nevertheless, the front and rear vacuum holders 9.1, 9.2 hold themselves in the second operating position BS2. The third and fourth control surfaces 43.3, 43.4 are at the first and second heights H1, H2 respectively.

(47) The invention has been described heretofore by way of exemplary embodiments. It is understood that numerous alterations and derivations are possible without thereby departing from the underlying inventive concept of the invention. The claims are deemed to be a constituent part of the description.