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(11) | EP 0 366 267 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Labeling apparatus |
| (57) A method and apparatus for applying sleeve labels to product containers including
a label gripping assembly for engaging a label and pulling it onto a product container
(20) and a web positioner (38) for adjusting the position of a next-to-be-applied
label prior to engagement by the label gripping assembly. During a label applying
cycle, the label being applied is severed from the web (32) along a line of weakness
interconnecting the end most label (32a) with the next-to-be-applied label, after
the next-to-be-applied moves to a predetermined position located downstream of an
initial position. The web positioner (38) reverse feeds the web until the leading
edge of the next-to-be-applied label retracts to the desired initial position. The
web positioner (38) includes a driven roll and a nip roll that is movable towards
and away from the driven roll by an actuator. The driven roll is continuously rotated
and the nip roll is driven into frictional engagement with the driven roll in order
to effect web retraction. |
Technical Field
[0001] The present invention relates generally to a method and apparatus for labeling products and in particular to an improved apparatus and method for applying flexible, tubular labels to product containers such as bottles.
Background Art
[0002] Various automated methods and apparatus for labeling product containers, such as bottles are known. In particular, U.S. Patent Nos. 4,412,876 and 4,620,888, both owned by the present assignee, disclose bottle labeling machines which are capable of automatically placing tubular labels on product containers such as "2-liter" soft drink bottles. In the apparatus described in the above two identified patents, a gripper mechanism grabs the endmost label of a chain of labels and pulls it onto a bottle. During the installation process, the endmost label is severed from the remainder of the chain.
[0003] With these prior bottle labelers, the final position of the label on the bottle is in large measure a function of its position with respect to the bottle when it is initially engaged by the gripper mechanism. In order to consistently and precisely install the labels onto the bottles, it was found that the initial position of the label prior to engagement by the label gripping mechanism, must be precisely controlled.
[0004] In U.S. Patent No. 4,565,592, also owned by the present assignee, an apparatus for monitoring the position of the "next-to-be-applied" label was monitored, and adjustments to its initial position were made prior to engagement by the gripper mechanism. In particular, the leading edge of the next-to-be-applied label was adjusted by a positioning mechanism that either raised or lowered a mandrel assembly about which the label was held in order to adjust the initial position of the label. As a result the labels would be substantially at the same position when engaged or gripped by the label applying mechanism. With the disclosed apparatus, accurate labeling could be achieved without disrupting or compromising the speed at which labels could be applied to the bottles.
Disclosure of the Invention
[0005] The present invention provides a new and improved method and apparatus for precisely locating a "next-to-be-applied" label prior to engagement with a label applying mechanism so that even more precise and accurate positioning can be achieved without substantially increasing the cost of the labeling machine. In the disclosed embodiment, a monitoring and positioning mechanism is disclosed which precisely locates the leading edge of the next-to-be-applied label, while a label already engaged by the grippers is being installed. The disclosed monitoring and positioning apparatus does not substantially effect the speed of the machine nor its reliability.
[0006] The disclosed apparatus can be used with the labeling machines disclosed in U.S. Patent Nos. 4,412,876 and 4,620,888, both of which are hereby incorporated by reference. In addition, the disclosed monitoring and positioning apparatus can be used with the packaging apparatus and method disclosed in copending application Serial No. , filed concurrently herewith (Attorney Docket 31854), which is also hereby incorporated by reference.
[0007] According to the preferred embodiment of the invention, a positioning mechanism controls the final position of the leading edge of the "next-to-be-applied" label which forms the lead label in a chain or web of interconnected sleeve-like labels. In the disclosed embodiment, the label gripping mechanism engages the lead label in the chain and pulls it towards a container located at a label applying position forming part of a labeling station. When the lead label or gripper mechanism reaches a predetermined position in its travel, a brake mechanism engages the web upstream of the lead bag and inhibits further movement. This causes the lead label to sever itself along a line of weakness as the gripping mechanism continues its movement.
[0008] According to the invention, the brake mechanism is operated so that the leading edge of the next-to-be-applied label is at a position that is beyond an ideal initial position for the leading edge. A drive mechanism is then activated to reverse feed the web until the leading edge reaches a desired initial position. This occurs as the previously severed lead label is being applied to the container located at the label applying position of the machine.
[0009] According to the invention, the positioning mechanism comprises a pinch roll assembly which includes a power driven drive roll and a back-up or nip roll. The web or chain of labels passes through the pinch roll assembly. During an initial portion of a label applying cycle when the label gripping mechanism engages the leading edge of the lead label, the drive roll and back-up roll are separated to define a gap in order to allow the web to freely move through the pinch roll assembly. After severance of the lead label from the web, the pinch roll assembly is activated to clamp the web between the nip and drive roll. The drive roll is reverse rotated in order to reverse feed the next-to-be-applied label until its leading edge is retracted to a predetermined position, preferably sensed by an optical or similar sensor. When the leading edge reaches the desired initial position, the pinch roll assembly is deactivated in order to disengage the web.
[0010] In the preferred and illustrated embodiment, the drive roll is continuously driven (in the reverse direction from the normal label feed direction) by an electric motor and the nip roll is pivotally mounted for movement towards and away from the drive roll. An actuator is used to move the nip roll towards and away from the drive roll. After severance of the lead label from the web, the actuator is energized to drive the pinch roll towards the drive roll thereby engaging the web and causing reverse movement. As soon as the position sensor senses the leading edge of the next-to-be-applied label, the nip roll is immediately retracted to release the web.
[0011] With the disclosed construction, extremely precise positioning of labels onto containers can be achieved. The disclosed apparatus and method can be added to existing labeling machines and is extremely cost effective.
[0012] Additional features of the invention will become apparent and a fuller understanding obtained by reading the following detailed description made in connection with the accompanying drawings.
Brief Description of the Drawings
[0013]
Figure 1 is a perspective view of a bottle labeling apparatus;
Figure 2 is a plan view of the bottle labeling apparatus shown in Figure 1;
Figure 3 is a fragmentary, side view of the labeling apparatus with exterior covers omitted to show interior details;
Figure 4 is a fragmentary, front view of the labeling apparatus shown in Figure 3;
Figure 5 is a side view of a web positioning mechanism constructed in accordance with the preferred embodiment of the invention and forming part of the labeling apparatus shown in Figure 1; and
Figure 6 is a top view of the web positioning apparatus shown in Figure 5.
[0014] Figure 1 illustrates the external appearance of a labeling apparatus constructed in accordance with the preferred embodiment of the invention. The labeling apparatus includes a sheet metal cabinet formed by a plurality of removable covers 10, 12, 14, 16. A control panel 18 contains a plurality of operator controls for controlling the operation of the apparatus. The disclosed labeling apparatus is adapted to apply tubular, flexible labels to containers such as "2-liter" soft drink bottles 20. It should be understood that the present invention is adaptable to a variety of labeling applications and should not be limited to the bottle labeling apparatus disclosed herein
[0015] Referring also to Figure 2, the bottles 20 are brought to the machine on a conveyor, indicated generally by the reference characters 22. The conveyor does not form part of the present invention and therefore its details are not shown. The conveyor 22 alone or in cooperation with a bottle advancing mechanism (not shown) advances a bottle on the conveyor to a label applying position or labeling station indicated generally by the reference character 28. After it is labeled, the bottle is advanced out of the labeling position by the conveyor or the bottle advancing mechanism and onto an exit conveyor 26 that carries the labeled bottles from the exit of the labeling apparatus.
[0016] Figures 3 and 4 illustrate in more detail, the labeling station 28 where a sequence or chain of labels in the form of a tubular web 32 are applied to individual containers. Referring in particular to Figure 3, the web 32 (shown in phantom) is unwound from a supply (not shown) and threaded around a series of pulleys 36 through a web positioner 38 constructed in accordance with the preferred embodiment of the invention, around a guide assembly 40 and over a mandrel assembly 42. The mandrel 42 expands the labels prior to separation of an endmost label 32a from the web 32. In addition, the mandrel assembly 42 maintains tension in the web 32.
[0017] The mandrel 42 extends inside the tubular web 32 and the web is expanded as it passes over the mandrel. The mandrel 42 is formed of a tubular sheet metal or plastic have a frusto-conical section 44 at its upper end and a generally cylindrical skirt 46 formed at its lower end. The skirt defines a pair of cut outs 48 on its lateral sides for enabling a label stretched about the base of the skirt to be gripped and pulled downwardly relative to the mandrel by a label applying assembly 49 including label gripping assemblies 50 (shown in Figure 4).
[0018] A supporting tongue or mandrel fin 53 below which the mandrel 42 hangs, extends upwardly from the mandrel 42 and carries rollers 54 which coact with a mandrel support 56 including rollers 57. The web 32 passes over the roller 54 and then the mandrel 42.
[0019] A web position detector 60 senses indicia on each successive label 35. When the label 35 is properly positioned with respect to the mandrel 42, the detector 60 produces a web brake operating signal for activating a solenoid actuated brake 62. The web position indicia are accurately located on each label and the detector 60 and mandrel 42 are positioned so that each indicia is sensed as it moves over the mandrel 42.
[0020] A preferred detector 60 detects visible light fluorescing from the invisible indicia on each label and is constructed as disclosed in U.S. Patent, 4,392,056 to Weyandt entitled "Control Marking Detector" which issued July 5, 1983 and is incorporated herein by reference. The position of the detector 60 relative to the mandrel 42 can be adjusted by a support assembly indicated generally by the reference character 61 and including a slot 61a and link arm 61b. The adjustment enables the detector 60 to be moved vertically and side to side.
[0021] Referring also to Figure 4, label gripping assemblies 50a, 50b positioned on either side of a center line 64 of the mandrel 42 (and web 32) are operative to grip a label positioned about the mandrel 42 and pull it downwardly over a container 20 positioned directly beneath the mandrel 42. The gripper assemblies 50a, 50b release the label when its properly positioned on the container and then are driven upwardly to grasp the next label and repeat the labeling cycle. As the gripper assemblies 50 move an endmost label downwardly with respect to the mandrel 42, the detector 60 senses the arrival of the next succeeding label and it activates the brake 62.
[0022] Two brake pads 63 (shown best in Figure 4) are driven into engagement with the web to pin the web against the mandrel 42. The force of engagement between the brake and web prevents the web from moving relative to the mandrel. As continued movement of the gripper assemblies 50 move the endmost label away from the mandrel 42, a line of weakness (such as defined by a line of perforations, 32a) gives way and the end most label is severed from the web 32.
[0023] The label applying assembly is reciprocally movable in a vertical plane by a carriage 51 (indicated generally in Figure 4) operatively connected to a drive system located in the base of the apparatus. The carriage 51 includes a pair of slide rods 52a, 52b that are slidably supported by upper and lower slide bearings 54, 55. The left and right hand halves 50a, 50b of the labeling applying apparatus 49 are adjustably clamped to the left and right slide rods 52a, 52b, respectively. The drive system for driving the label applying assembly is preferably of the type disclosed in U.S. Patent 4,620,888 which is hereby incorporated by reference. In summary, the drive system includes a drive motor which rotates a cam that operates an arm connected to the carriage 51 such that rotation of the cam produces vertical, reciprocating motion in the arm and hence the label applying assembly 49. The drive system does not form part of the present invention and will not be discussed further. Reference should be made to U.S. Patent No. 4,620,888 for additional details.
[0024] The description of the labeling apparatus has been substantially similar to the description in U.S. Patent Nos. 4,412,876 to Lerner et al. and U.S. Patent No. 4,620,888 to Easter et al. The description regarding the indicia detector 60 is substantially similar to the description in U.S. Patent No. 4,565,592 to Wehrmann and U.S. Patent No. 4,392,056 to Weyandt which are both incorporated by reference. Additional details regarding the construction, arrangement or operation of the brake 62, gripper assemblies 50, mandrel 42 and indicia detector 60 can be obtained by reference to these aforementioned and incorporated patents.
[0025] In U.S. Patent No. 4,565,592 a method and apparatus for adjusting the position of the mandrel 42 and hence the label surrounding the mandrel, prior to installa tion, was disclosed. In U.S. Patent No. 4,565,592, a detector was used to monitor the position of the label about to be installed, and in conjunction with a control system, activated a stepper motor attached to the mandrel support (i.e. 57) for raising and lowering the mandrel 42 in order to ensure that the bottom of the label about to be applied, was at a pre-set distance above the container. By precisely locating the bottom of the label, the final installed position of the label on the container was made relatively consistent.
[0026] In the present invention a detector 90 which may be the same type of detector disclosed in U.S. Patent No. 4,565,592 also monitors the position of the endmost label 35. However in the present invention, the web positioner assembly 38 is used to precisely adjust the position of the endmost label prior to installation.
[0027] According to the invention, the machine is adjusted such that when severance of the label being applied occurs, a bottom edge 91 of the next-to-be-applied label 35 is lower than a desired initial ideal position. In the preferred embodiment, this is achieved by adjusting the web detector 60 such that the web brakes 62 are applied to the web 32 after the line of weakness 32a has moved past an ideal or desired position.
[0028] After severance occurs, the web positioner 38 is activated to reverse feed the web 32 in order to retract the label until the leading edge 91 of the next-to-be-applied label is at a desired position. With the disclosed invention, the rather complex mechanism for making position adjustments to the mandrel is eliminated and replaced by a relatively straight forward mechanism for moving the web in only one direction, i.e. retraction, without sacrificing reliability or cost.
[0029] Referring also to Figures 5 and 6, the construction of the web positioner 38 is illustrated. In the preferred embodiment the web positioner 38 comprises a pinch roll assembly including a driven roll 92 and a nip roll 94. Referring also to Figure 3, the web positioner includes frame structure indicated generally by the reference character 96 and in particular includes side plates 98a, 98b. A support plate 100 extends between the side plates and also mounts a clamping bar arrangement 102. The clamping bar 102 enables the web positioner to be adjustably clamped to a pair of support rods 106. This arrangement enables the vertical position of the web positioner 38 to be easily adjusted.
[0030] In the preferred construction, the driven roll 92 is rotatably mounted between the side plates 98a, 98b and is connected to an electric motor 108. In the preferred operation, the driven roller is continually reverse rotated by the motor 108 during machine operation.
[0031] The nip roll 94 is rotatably supported between bearing members 110 that are attached to a pivot bar 112. The pivot bar is pivotally connected to the side members 98a, 98b at pivot points 113 so that the nip roll 94 can be moved towards and away from the driven roller 92. An actuator 114 which may be pneumatically operated, is operatively attached to the pivot bar 112 and is used to move the nip roller 94 into frictional contact with the driven roller 92. In particular, the actuator 114 includes an actuating rod 116 operatively connected to a yoke member 118 bolted to a central portion of the pivot bar 112. When pressurized, the actuator rod 116 extends to drive the nip roller 94 into frictional contact with the driven roller 92. As seen best in Figure 3, the web 32 passes through a gap G defined between the driven roller 92 and the nip roller 94 when the actuator 114 is de-energized. The web passes freely between the rolls during a label applying cycle. When the label being applied is severed from the remainder of the web, the sensor 90 is enabled to sense the position of the leading edge of the next-to-be-applied label 35. As indicated above, the web brakes 62 and control system are adjusted so that the leading edge 91 of the next-to-be-applied label 35 is below the desired position and as a result, the leading edge of the web is not detected. The control system associated with the detector 90 actuates the actuator 114 to cause the nip roll 94 to frictionally clamp the web between itself and the driven roller 92. As indicated above, the driven roller is continuously rotated by the drive motor 108 in a reverse feed direction. Movement of the nip roller 94 into frictional contact with the web 32 causes the web to be reverse fed. As soon as the detector 90 senses the leading edge 91 of the next-to-be-applied label, the actuator 114 is immediately de-energized thereby retracting the nip roll 94 and immediately releasing the web. The next-to-be-applied label (now the endmost label) is now accurately positioned and is ready to be applied to the next container located at the labeling station. With the disclosed apparatus, very precise positioning of the lead label 35 in the chain of labels 32 can be achieved. By precisely locating the lead label, accurate positioning of the label on the product container is also achieved. This is effected with a relatively simple control mechanism that is highly reliable and is believed capable of a positioning precision not achievable with prior mechanisms.
1. Apparatus for repetitively applying a series of connected sleeve labels about a
plurality of containers comprising:
a) gripper means for gripping and moving an end most label along a travel path to a labeling work station;
b) stretching means for stretching said end most label into a configuration for application to a container;
c) separation means for separating the end most label from the remainder of the chain of labels;
d) monitoring means for monitoring the position of the subsequent label after said end most label is severed; and
e) web positioning means responsive to the monitoring means for reverse feeding said chain until said subsequent label is reverse fed to a desired position.
2. The apparatus of Claim 1 wherein said positioning means comprises a pinch roll
assembly including a driven roll and a nip roll and an actuator for causing clamping
engagement between said driven roll and said nip roll whereby engagement and reverse
feeding of said web occurs.
3. The apparatus of Claim 2 wherein said nip roll is pivotally supported for movement
towards and away from said driven roll and said actuator is operatively connected
to a nip roll support assembly.
4. The apparatus of Claim 1, 2 or 3 wherein said monitoring means monitors the leading
edge of said subsequent label.
5. A machine for automatically placing a series of sleeve labels over a series of
bottles or cans comprising:
a) a mandrel for stretching said labels to a shape to be slipped over said bottles or cans and a gripper assembly for gripping in turn each of said stretch labels and moving each of said labels to a bottling station where said sleeve is slipped over a bottle or can;
b) positioning means for reverse feeding said web;
c) sensing means for sensing the relative position of a next-to-be-applied sleeve with respect to said bottling station; and
d) control means for energizing said web positioner and operative to reverse feed said web until the next-to-be-applied label is retracted to a predetermined position prior to engagement by said gripper assembly.
6. A method for applying tubular, sleeve labels to product containers, comprising
the steps of:
a) positioning a product to be labeled at a label applying position;
b) engaging a label to be applied with a label gripping assembly in order to pull said label onto said containers;
c) monitoring the position of a next-to-be-applied label and energizing a web brake mechanism when said next-to-be-applied label has moved beyond a desired position;
d) reverse feeding said web until said next-to-be-applied label reaches a predetermined position.
7. The method of Claim 6 further comprising the step of monitoring a leading edge
of said next-to-be-applied label.
8. A web positioner for a labeling apparatus comprising:
a) a detector means for detecting the position of a next-to-be-applied label;
b) a pinch roll assembly located upstream of said detection means and including a driven roller, a pinch roller and an actuator for causing clamping engagement between said driven roller and said pinch roller;
c) control means for actuating said actuator to cause clamping engagement between said driven roller and said pinch roller in order to retract said web until said detector means detects that said next-to-be-applied label is at said predetermined position.
9. The apparatus of Claim 8 wherein said pinch roller is mounted for movement towards
and away from said driven roller.
10. The apparatus of Claim 8 or 9 wherein said driven roller is continuously rotated
in a reverse feed direction so that said web is retracted upon clamping engagement
between said driven roller and said pinch roller.