Roll product tail securing system
BACKGROUND OF INVENTION 
     1. Field of Invention 
     This invention relate to an apparatus and method for securing the unaffixed tail of a roll product to a convolution thereof underlying the tail with a flexible sealing element such as a label. 
     2. Description of the Prior Art 
     A wide variety of devices are known in the prior art for applying labels or other flexible sealing elements to roll products. Such prior art arrangements are characterized by their complexity and consequent high cost In addition, such devices often cannot readily be used to apply the labels to roll products having different physical characteristics, such as differing lengths. When the sealing element is a label, for example, the label will in all probability have indicia imprinted thereon that is only applicable to a given size of roll product. Consequently if a roll product of a differing size were introduced into the system an incorrect and misleading label would be applied. Even though some prior art systems may be adjusted to accommodate different sized roll products such change over will in most cases render the system appropriate for only one type of roll product without another adjustment being made. That is, such systems do not lend themselves to receiving and sealing more than one size of roll product at any given time. This drawback means that a manufacturer of roll products of various sizes may be required to employ a separate tail sealing and labelling machine in conjunction with each converting machine producing a different sized roll product. This obviously adds to the overall cost of producing the roll products and the machinery is utilized inefficiently. 
     BRIEF SUMMARY OF THE INVENTION 
     The present system for securing the unaffixed tail of a roll product to a convolution thereof underlying the tail with a flexible sealing element has the ability to accommodate roll products, such as paper towels or the like, of different sizes. The system automatically senses a predetermined physical characteristic of the roll product and delivers to the roll product an appropriate flexible sealing element such as a label appropriate to the sensed characteristic. In the preferred embodiment illustrated herein the sensed physical characteristic is the length of the roll product and a label correctly identifying that length will be delivered to the roll product and applied thereto so that the label is positioned on both the tail and the convolution of the roll product underlying the tail. If a roll product having a different physical characteristic such as a different length is introduced subsequently into the system, a different label will automatically be selected, delivered to the roll product and secured thereto. This arrangement does away with the necessity of manual adjustments being made to accommodate roll products with different physical characteristics. This flexibility enables the system of the present invention to be employed in the labelling of roll products having different physical characteristics coming from a plurality of converting stations upstream. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a preferred form of apparatus constructed in accordance with the teachings of the present invention; 
     FIG. 2 is a perspective view of selected portions of the apparatus of FIG. 1 providing a schematic illustration of the operation thereof; 
     FIG. 3 is a plan view of selected portions of the apparatus of FIG. 1; 
     FIG. 4 is a side elevational view of the apparatus portions shown in FIG. 3; and 
     FIGS. 5-13 illustrate in schematic fashion sequential steps of the method of the invention. 
    
    
     DETAILED DESCRIPTION 
     Referring now to the drawing, a prefererd form of apparatus for carrying out the teachings of the present invention is illustrated. The apparatus includes a roll product receiving station indicated generally by reference numeral 10 which includes selectively rotatable rollers 12 and 14 for receiving and supporting thereon a roll product 16 having an unsecured tail 18. It is a function of the apparatus to apply labels or other flexible sealing elements to the tail 18 and a convolution of the roll product underlying the tail. Any suitable means may be employed to deliver the roll product end wise into position over the rollers 12 and 14, one such suitable means being a belt conveyor 20 shown in phantom in FIG. 1. Belt conveyor 20 delivers the roll product to a second belt conveyor 22 comprising part of the roll product receiving station and disposed between rollers 12 and 14. A suitable mechanism (not shown) is preferably employed to raise and lower belt conveyor 22 relative to the rollers in a manner well known in the art. When belt conveyor 22 is in raised position it provides full support for the roll product and prevents the roll product from engaging the rollers. When the belt conveyor 22 is lowered, on the other hand, it is out of engagement with the roll product and the rollers 12 and 14 provide full support for the roll product. It will be appreciated that the conveyor 22 is in raised position when it receives the roll product from conveyor 20. 
     The labels or other sealing elements to be secured to the roll product are maintained in sealing element supply stations 26 and 28. Station 26 contains labels 30a and station 28 contains labels 30b. The labels may if desired be of the same size but they ordinarily have imprinted thereon indicia describing a physical characteristic of the roll product such as the length thereof. Consequently, it is important that the correct label be applied to the correct roll product. As may perhaps best be seen with reference to FIG. 4, each supply station is in the form of a magazine for containing a supply of sealing elements in stacked relationship. Each of the magazines has an opening 34 which is tilted at an angle to the horizontal so that the labels are continually urged toward the opening under the influence of gravity. In the absence of an outside force being applied to the labels. They are retained in the magazine by lips 36 defining the opening. 
     Sealing element supply stations 26 and 28 are mounted over conveyor means in the form of two conveyor belts 40 and 42 disposed in parallel and defining a space therebetween. Conveyor belts 40 and 42 are mounted for movement on support rollers rotatably journaled on the apparatus framework 44. The conveyor belts 40 and 42 have apertures 50 formed therein which provide communication between the upper surface of the conveyor belts and a vacuum box 52 positioned thereunder. 
     Removal means is provided for removing the labels 30a and 30b from their respective magazines and transporting the labels to conveyor belts 40 and 42. More specifically, and as may perhaps best be seen with reference to FIGS. 3 and 4, the removal means includes two reciprocatable elements in the form of pivotally mounted arms 56 and 58 having vacuum cups 60 disposed thereon as illustrated. Each arm is pivotally mounted at one end thereof on apparatus framework 44 and is in the form of an L-shaped bellcrank. Each arm is connected to a suitable pneumatic prime mover 62 which when actuated will cause the arm to move from the retracted position occupied by arm 56 in FIG. 4 to the pick up station occupied by arm 58 in FIG. 4. In this latter position the vacuum cups associated with the arm will contact the outermost label of the magazine with which the arm is associated. Vacuum is supplied to the vacuum cups through a conduit 66 leading thereto from a suitable source (not shown) of vacuum. Through a suitable conventional valving arrangement (not shown) the vacuum to cups 60 is shut off after the arm again moves into retracted position and the label 30a or 30b attached to the cups engages conveyor belts 40 and 42. The vacuum supplied by vacuum box 52 through apertures 50 will then cause the labels to be retained on the upper surface of the belts. 
     Having desribed generally the primary components of apparatus constructed in accordance with the teachings of the present invention, the cooperative relationship of the components and their operation in carrying out the method of the present invention will now be described. This operational relationship and function may perhaps best be understood by referring to FIGS. 5-13 and the sequential steps of operation illustrated therein. In the interest of simplicity, the control system employed to control the operational relationship and function of the components will not be described in detail since such control systems are well within the capabilities of one skilled in the art. 
     In FIG. 5 a roll product 16 is illustrated being delivered end wise into the roll product receiving station by belt conveyor 22 which is in a raised position to maintain the roll product out of engagement with rollers 12 and 14. As the roll product moves into the receiving station a predetermined physical characteristic of the roll product, i.e. the length thereof, is sensed by sensing means in the form of photoelectric devices 70 and 72 of any suitable type mounted above the receiving station. Through a suitable control system belt conveyor 22 will halt movement when the leading edge of the roll product intersects the beam from photoelectric device 70. Photoelectric device 72, on the other hand, senses the length of the roll product delivered to the receiving station. If the distance between devices 70 and 72 is greater than the length of the roll product the beam from photoelectric device 72 will not be interrupted. If, on the other hand, the roll product is greater in length than the distance between photoelectric devices 70 and 72 the beam from device 72 will be interrupted. Depending upon which of these two conditions exists one or the other of labels 30a and 30b will be removed from their respective magazines, delivered to conveyor belts 40, 42 and applied to the roll product in a manner to be described below. In FIG. 5 arm 56 has been actuated and the vacuum cups 60 attached thereto brought into engagement with the outermost label 30a at station 26. Through a suitable mechanism the arm 56 will immediately return to its retracted position leaving the removed label 30a on top of the conveyor belts 40 and 42. 
     Conveyor belts 40 and 42 will then move in counter clockwise direction as viewed in FIG. 6 to transport label 30a in the direction of roll product 16. During this stage of the operation the upper surface of the label 30a is rendered in an adhesive condition. Assuming, for example, that the upraised surface of the label has previously had glue applied thereto and dried thereon, the adhesive condition is created by passing the glued surface under a water spray device 76. Alternatively, of course, spray device 76 could be used to apply a wet glue to a previously non-glue bearing surface. Movement of conveyor belts 40, 42 temporarily ceases when the trailing edge of label 30a reaches the beam of photoelectric device 78 disposed under the path of movement thereof as shown in FIG. 7. The next stage of operation is shown in FIG. 8 whereat the conveyor 22 is dropped to retracted position and the rollers 12 and 14 commence rotation in a counter clockwise direction as viewed in that figure. This causes the roll product 16 to rotate in a clockwise direction, that is, the direction tending to wind the tail of the roll product about the remainder thereof. Substantially simultaneously with this operation an air jet 86 disposed above the roll product directs a blast of air against the tail and causes same to be positioned on a platform 88 (FIG. 1) disposed over the path of movement of label 30a. The air blast will continue until the trailing edge of the tail 18 passes under the beam of yet another photoelectric device 94 which functions to cut off air to jet 86 through any suitable valving arrangement. Photoelectric device 94 in response to this condition will also cause renewed movement of conveyor belts 42 and 40. 
     The label 30a will be delivered by the conveyor belts at the same speed at which tail 18 is moving due to rotation of roll product 16 by rollers 12 and 14. What happens next is best illustrated by the sequential FIGS. 9-13. First, the label 30a passes through the space defined by platform 88 and conveyor belts 40 and 42. The label 30a then passes through a nip defined by the roll product 16 and roller 14 as shown in FIG. 10. The label 30a will be affixed to the tail 18 at this point due to the adhesive nature of the upper surface of the label and due to the nip pressure between the roll product and roller 14. Continued rotation of rollers 12 and 14 will completely wind the tail 18 over its underlying convolution and label 30a will, as shown in FIG. 11, be pressed into engagement with both the tail and the underlying convolution by passing through the two nips defined by rollers 12 and 14 and product 16. FIG. 12 shows the label 30a disposed at the top of the roll product and secured into position. The final stage of operation is illustrated in FIG. 13 wherein belt conveyor 22 is again moved to raised position, actuated, and delivers the sealed roll product out of the receiving station.