Patent Grant
8156987
1. Field of the Invention
This invention pertains to automatic high-speed self-adhesive labeling machines. More particularly, the present invention relates to automatic high-speed labeling machines for labeling cylindrical containers which are linearly fed through the machine in a straight line, but are caused to rotate about their vertical axes through three points of contact with a powered rotating belt (or wheel or drum) and two passive rollers held at the apex of a freely rotating star wheel which results in the transfer of at least one label to a container and thereby causing the container to wrap the label around itself.
2. Description of the Prior Art
The prior art is replete with descriptions of labeling machines for cylindrical containers which all accomplish the same purpose but by different means.
For example, in U.S. Pat. No. 4,714,515 (1987), Hoffman describes a “straight line” container labeling apparatus including oppositely moving main drive and porous labeling belts, and a timing star and second star wheel having rollers on the ends of its arms for engaging and aligning each container while allowing it to rotate freely between the belts. In this apparatus, the leading edge of a continuous strip of label stock is gripped by a radially retracted vacuum pad located on the periphery of a rotating vacuum drum and pulled until a cutting knife carried directly on the drum severs the trailing edge of each label. The retracted vacuum pads are selectively extendable for application of adhesive and then may be retracted to allow fingers to strip each gummed label from the drum and transfer it to a vacuum wheel over which is entrained a porous labeling belt that carries each label to a container driven by the drive belt and aligned by the second star. Although workable in theory, this fairly complex labeling apparatus obviously required critical synchronization of its interrelated elements to function properly. During high speed labeling operations (more than 125 containers per minute) several problems arose. For example, containers would often jam as they left the timing star and became wedged by an arm of the aligning star. Additionally, the reciprocating vacuum pads on the vacuum drum did not provide a uniform glue pattern on the labels which often caused glue to be deposited on the porous labeling belt resulting in labels stuck thereon. Moreover, part of the cutting means was located on the periphery of the vacuum drum which, of course, increased in rotational speed with the speed of the labeling operation, and often resulted in improperly cut labels. Thus, the labeling apparatus as above described was short lived in actual high speed production and is not known to be in use today. This method disclosed a star wheel with small rollers (bearings) only at the top and/or at the bottom of the container to assist in the stability and the guiding the containers but this star wheel is powered by the system and is continuously rotating by necessity as this is a continuous motion machine, hence is a complex and expensive system.
In U.S. Pat. No. 4,931,122 (1990), Mitchell discloses another straight through labeling machine with a “feed-screw” for moving cylindrical containers past, but in tangent to, a vacuum drum containing precut gummed labels. The containers travel along a guide-way to the feed screw where they also contact an endless belt causing the containers to spin counter-clockwise around their vertical axes. As the feed screw advances the containers linearly past, but in tangent to, the vacuum drum, a label is transferred to a container and is preferably wrapped around it before said container exits the feed screw. Although this labeling machine appears to be an improvement over the cited prior art, the counter-clockwise rotation of the containers while being linearly advanced within the feed screw causes vertical drag or a retarding force acting on the containers due to friction which is undesirable in high speed labeling operations. Although the feed screw has the effect of aligning the containers vertically, the alignment is only between the root of the screw and the rotating drum, which alignment is improved only by constraining the containers more and more which has adverse effect of jamming the labels as the constraints are tightened.
In U.S. Pat. No. 4,428,474 issued on Jan. 31, 1984 to Gau, et al., disclose an apparatus for aligning containers in a labeling machine. The apparatus comprises pairs of moveable arms, adjacent container pockets on a star wheel, and a belt carried on the arms. The belt is rotated by a motor which, in turn, causes a container in the star wheel pocket to rotate. A sensor detects marks on the containers and applies a brake to stop rotation of the belts, thereby locking the containers in a pre-determined angular orientation. While this would rotate containers and stop them at an appropriate position for labeling with respect to a witness mark on the container, the system is complex and expensive.
Aesus literature Premier wrap 20060621 discloses a system of rollers which index forwards and backwards, while capturing containers against a rotating wrap belt into a position to appropriately apply a pressure sensitive label. This system adequately grips the container, holds it correctly in a vertical axis, allows time for the container to rotate (if required) to a location where the label should be applied relative to a witness mark (seam, spot, or other witness mark) and then signals the label head to dispense the label (or labels) while the container continues to be rotated and held aligned in the vertical axis. Although the system works well, it is limited in speeds to approximately 50 containers per minute.
Aesus literature Premier star wrap 20080122 describes a system of a continuously rotating star wheel that has rollers at the apex of the star wheel which hold the container against a wrap belt similarly, with the whole system being driven by servomotors that are synchronized in order to position the container at the precise point where label needs to be applied. This system works at speeds greater than 50 containers a minute even to speeds in excess of 300 containers per minute, but the combination of servomotors and precise controls making a costly and unaffordable solution for many labeling applications, and it does not have the capability of applying more that one sequential label (ie: separate front and back labels) to each container as the container is continuously moving away from the label dispensing apparatus.
What is needed in the industry is a system that can present the container to the label dispenser at speeds greater than 50 containers per minute, be able to hold the container precisely in the vertical axis, allow the rotation of the container to a witness mark (if required), to subsequently signal the label dispenser to dispense the label or labels, then continue to hold the container rotating in the vertical axis until the label has finished dispensing and then release the correctly and accurately labeled container, the system manufactured in a simple and affordable configuration.
The present invention overcomes the disadvantages and limitations of the prior art by providing a high speed inline machine to assemble labels onto cylindrical container that can be applied with respect to a witness mark (seam, spot or other witness mark) or simply applied to a regular cylindrical container, at speeds over 50 containers per minute.
Well known in the industry are label dispensing devices which dispense pressure sensitive labels by feeding them off the end of their dispense blade/plate at speeds as fast as 160 meters per minute. (Greater than 8 feet per second). Once the label comes off the dispensing plate it needs to coincide precisely with the container that is being labeled. In the instance of a cylindrical container, if the container is not held precisely in the vertical axis and it is not rotated at the same speed at which the label is being dispensed problems will occur. Either the label will be severely wrinkled, or if the container is not held correctly in the vertical axis the label will spiral onto the container, both instances being unsatisfactory as a final product.
Referring to
Fingers 31, 32 protrude from indexing cylinders 15, 16 respectively, indexing cylinders 15, 16 independently operated. In operation of star wheel labeler 100, weight of containers 11 on conveyor 10 typically is enough to rotate star wheel 13 in the direction of rotational arrow 40 when container 11 presses against one roller 14 while moving along with conveyor 10. Rotation of star wheel 13 is stopped as one finger 31, 32 extends from its respective indexing cylinder 15, 16 upon command from a controller (not shown) and is engaged by one pin 41-44 rotating thereagainst, thus interference by finger 31, 32 with one pin 41-44 stopping rotation of star wheel 13 and aligning one pocket 34 directly opposite wrapper 50. At that time container 11 will be spinning by action of wrapper 50 pressing against container 11, container 11 captured between wrapper 50 and rollers 14 on star wheel 13. Coincidentally, either label dispensing device 17 dispenses at least one label, or waits momentarily until a signal from a sensor 18 which recognizes a container 11 in proper position and/or a witness mark on container 11 (if so required) thereafter causing label dispensing device 17 to dispense a label. Once the label has been dispensed and container 11 rotated through an arc at least equal to the length of the label to fully press the label against container 11, the engaged finger 31, 32 retracts and the retracted finger 32, 31, which is positioned to allow rotation of star wheel one pocket 34 distant, extends thus allowing star wheel 13 to rotate one pocket 34, star wheel 13 being pushed by the weight of containers 11 on conveyor 10. For instance, referring to
As conveyor 10 transports cylindrical containers 11 in a linear queue, it should be readily apparent that the large, complicated container capturing systems of the prior art are rendered unnecessary. Cylindrical containers 11 remain in a straight line from the entering queue, through the labeling process an onto the take away queue. Wrapper 50 may be a continuous moving wrapping belt 12 trained around spaced apart drums, such as drum 51, or may be comprised of a single drum 51 powered by a prime mover 45. In the preferred embodiment, wrapper 50 comprises continuously moving wrapping belt 12 trained around drums and powered by prime mover 45, continuously moving wrapping belt 12 moving in a direction indicated by directional arrow 30 thus providing spinning rotation to containers 11 when contacted thereby. Containers 11 are stopped approximately in line with spindle 46 of drum 51 and are held in that position by a pocket 34 on star wheel 13, pocket 34 established by a cusp between apices 27 of star wheel 13, apices 27 provided with rollers 14 on apices 27 thereof. Star wheel 13 could freely rotate, driven solely by containers 11 traveling in a straight line except star wheel 13 is held in position by either indexing cylinder 15 or indexing cylinder 16, which alternately engage and disengage to enable star wheel 13 to move one pocket 34 at a time. When container 11 is in the appropriate position as detected by sensor 18, label dispenser 17 will dispense at least one label. The label has a leading edge tacked to container 11 by dispense blade 19 on label dispenser 17 and, as container 11 will be spinning, because it is held in position by rollers 14 and spinning wrap belt 12, the label will be wrapped around container 11 and firmly adhered thereto by the pressing action of the three contact points. When label dispenser 17 has finished dispensing labels, cylinder 15 (or 16) retracts and cylinder 16 (or 15) will engage, allowing star wheel 13 to rotate one pocket 34 containing the next container 11 in the linear queue. Though the figures show eight cusps or pockets 34, it is fully understood that star wheel 13 may have at least three cusps, more preferably an even number between four and twenty four cusps.
This system also enables the possibility of placing two or more labels on the same container 11 while container 11 is rotating in its pocket 34. Label dispensing device 17 can carry two or three or more different labels, which labels can be dispensed one after the other, at an appropriate time delay while container 11 is still held in its pocket 34. Once the appropriate number of labels have been dispensed, star wheel 13 would be allowed to rotate, and the operation will be repeated on the next container 11. For instance, sensor 18 may be used to detect an edge of a previously applied label, recognizing the edge as an indexing mark and rotate container 11 through a specified angle before dispense blade 19 applies a subsequent label to container 11. It is also possible for multiple labels on a single backing tape to be applied to container 11 by repeated strokes of dispense blade 19 which tacks each label in sequence to container 11. Though in the preferred embodiment, conveyor 10 is horizontal and star wheel 13 and wrapper 50 ensure that container 11 is held perfectly at a right angle to conveyor 10 it is possible within the scope of this invention to orient star wheel labeler 100 at another designated angle with respect to horizontal, containers 11 supported by a shoe alongside containers 11.
While the present invention has been described with reference to the above described preferred embodiments and alternate embodiments, it should be noted that various other embodiments and modifications may be made without departing from the spirit of the invention. Therefore, the embodiments described herein and the drawings appended hereto are merely illustrative of the features of the invention and should not be construed to be the only variants thereof nor limited thereto.
| Number | Name | Date | Kind |
|---|---|---|---|
| 4083389 | Rosen et al. | Apr 1978 | A |
| 4428474 | Gau et al. | Jan 1984 | A |
| 4714515 | Hoffmann | Dec 1987 | A |
| 4931122 | Mitchell | Jun 1990 | A |
| 5028293 | Harvey | Jul 1991 | A |
| 5082520 | West et al. | Jan 1992 | A |
| 6494238 | Sindermann | Dec 2002 | B2 |
| 6793755 | Schaupp et al. | Sep 2004 | B2 |
