Patent Publication Number: US-2011061815-A1

Title: Device for sensing curled film in laminating machine

Description:
BACKGROUND OF THE INVENTION 
     1. Technical Field 
     The present invention relates to a device for sensing a curled film in a laminating machine and, more particularly, to a device for sensing if a to-be-laminated object adheres to rollers in a laminating machine. 
     2. Description of Related Art 
     Lamination is widely used for document preservation and is carried out in the following manner. Photographs or other planar objects of importance (e.g., paper-based pictures or documents) are sandwiched between laminating films to form a to-be-laminated object, which is then fed into a laminating machine so as to be hot-pressed and completely sealed. Thus, the important materials, such as photographs and pictures, inside the resultant laminate are tightly enclosed by the laminating films and protected against moisture and damage. 
     However, there is a tremendous risk when the to-be-laminated object containing the document undergoes lamination. This is because a document needing lamination must be of consequence, worth preservation, and in most cases the only copy in existence. Should a mistake occur during the laminating process, the important document, which is very likely the only existing copy, may be damaged. Now that mistakes are inevitable, a laminating machine must be provided with certain safety measures to prevent important documents from being ruined by accident. 
     Presently, the most frequent cause of document damage by a laminating machine is adjusting the hot-press temperature too high, which makes laminating films adhere to and get stuck between the rollers so that the document between the laminating films is damaged. Another highly probable cause is inserting the to-be-laminated object in a wrong direction. Referring to  FIG. 6 , a to-be-laminated object  50  is composed essentially of an upper laminating film  501 , a lower laminating film  502 , and a document  503  sandwiched therebetween. As the upper laminating film  501  and the lower laminating film  502  are already sealed together at one end, the document  503  usually has one end pushed against the seal end of the upper and lower laminating films  501 ,  502 . The sealed end also serves as a leading end  51  when the to-be-laminated object  50  is inserted into the laminating machine for lamination. If the to-be-laminated object  50  is inadvertently inserted in a reverse direction, i.e., with a rear end  52  going in first, as indicated by the dash-line arrow in  FIG. 6 , the to-be-laminated object  50  will touch the rollers of the laminating machine with the rear end  52 . Therefore, when hot-pressed by the rollers, the to-be-laminated object  50  may be curled around the rollers instead of advancing along a tangential direction thereof. It is very likely that the beginning section of the to-be-laminated object  50  will be enough to get the rollers stuck so that the motor runs without load thereafter. Eventually, related circuits will be burnt, or the laminating machine itself is damaged, thereby crunching or even destroying the precious document to be laminated. 
     While it is necessary to adjust the hot-press temperature according to the size of the to-be-laminated object, and the to-be-laminated object is always subject to the possibility of being unintentionally fed in a wrong direction, any such mistake may damage the document which is supposed to be protected by lamination. Therefore, it is imperative that a laminating machine be equipped with an effective sensing device to prevent losses caused by operational mistakes. 
     BRIEF SUMMARY OF THE INVENTION 
     It is a primary objective of the present invention to provide a design which, upon occurrence of a to-be-laminated object being curled around rollers of a laminating machine, is capable of detecting the occurrence immediately, providing an alert, and rotating the rollers reversely so as to eject the to-be-laminated object safely. 
     To achieve the above and other objectives, the present invention provides a device for sensing a curled film in a laminating machine, wherein the device essentially includes rollers and a photoelectric sensor disposed behind the rollers. Working on the principle that reflectance varies with surfaces of different objects, the photoelectric sensor continuously projects a visible or invisible light onto surfaces of the rollers. When there is a foreign matter on the rollers, or when a laminating film is curled around one of the rollers, the intensity of reflected light received by the photoelectric sensor changes. The change of intensity is converted by means of the photoelectric sensor and related circuits into a change of voltage so as to activate a safety mechanism, which includes giving off an alarm and ejecting the to-be-laminated object. Thus, not only is the motor of the laminating machine prevented from burning, but also the to-be-laminated object is protected from damage. 
    
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
       The invention as well as a preferred mode of use, further objectives, and advantages thereof will be best understood by referring to the following detailed description of an illustrative embodiment in conjunction with the accompanying drawings, wherein: 
         FIG. 1  is a sectional view of a laminating machine using a device of the present invention for sensing a curled film in the laminating machine; 
         FIG. 2  is a top view of the laminating machine illustrated in  FIG. 1 ; 
         FIG. 3  is another sectional view of the laminating machine illustrated in  FIG. 1 , wherein the lamination machine is in normal operation; 
         FIG. 4  is yet another sectional view of the laminating machine illustrated in  FIG. 1 , wherein a to-be-laminated object is curled around a roller; 
         FIG. 5  is still another sectional view of the laminating machine illustrated in  FIG. 1 , showing how the device of the present invention solves the problem presented in  FIG. 4 ; 
         FIG. 6  is a perspective view of a to-be-laminated object; and 
         FIG. 7  is a flowchart showing operation of the device of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Please refer to  FIGS. 1 ,  2 , and  3  for a laminating machine. A set of front rollers  20 ,  21  and a set of rear rollers  22 ,  23  are provided in a machine body  10  of the laminating machine and properly spaced from each other. The front rollers  20 ,  21  and the rear rollers  22 ,  23  are driven, through gear transmission, by a power unit  11  provided on a lateral side of the machine body  10 , so as to rotate in predetermined directions. 
     A front guiding member  30 , an intermediate guiding member  31 , and a rear guiding member  32  are disposed in front of the front rollers  20 ,  21 ; between the front rollers  20 ,  21  and the rear rollers  22 ,  23 ; and behind the rear rollers  22 ,  23 ; respectively. The guiding members are intended to guide and support a to-be-laminated object  50  and ensure that the to-be-laminated object  50  moves smoothly along the correct directions. 
     At least one photoelectric sensor  40  is provided behind one of the front rollers  20 ,  21 . In an embodiment of the present invention, three sets of photoelectric sensors  40 ,  41 ,  42  are provided, as shown in  FIG. 2 . Depending on the width of the machine body  10  of the laminating machine, the number of the photoelectric sensors  40 ,  41 ,  42  may be increased. Furthermore, in order to provide timely sensing, the photoelectric sensors  40 ,  41 ,  42  are preferably located on horizontal centerlines L 1 , L 2  extending rearward from the front rollers  20 ,  21 . As shown in  FIG. 1 , two photoelectric sensors  40  are provided respectively on the horizontal centerlines L 1 , L 2  extending rearward from the upper and lower front rollers  20 ,  21 . 
     Referring to  FIG. 6 , the to-be-laminated object  50  is composed mainly of an upper laminating film  501 , a lower laminating film  502 , and a document  503  sandwiched therebetween. The upper laminating film  501  and the lower laminating film  502  are sealed together at one end in advance, and the document  503  is pushed against the sealed end of the upper and lower laminating films  501 ,  502 . The sealed end also serves as a leading end  51  when the to-be-laminated object  50  is inserted into the laminating machine for lamination. If the to-be-laminated object  50  is inserted reversely by mistake, i.e., along a direction indicated by the dash-line arrow in  FIG. 6 , the to-be-laminated object  50  tends to advance with difficulty or get stuck. And these problematic scenarios are exactly what the present invention aims to solve. 
     Referring to  FIG. 7 , the effects of the present invention is achieved by the following steps. 
     At step  60 , as shown in  FIGS. 3 and 7 , the to-be-laminated object  50  is placed into the machine body  10  for lamination. Normally, the to-be-laminated object  50  is inserted with the leading end  51  going in first, and the laminating process is completed after the to-be-laminated object  50  is heated and pressed by the front rollers  20 ,  21  and the rear rollers  22 ,  23  successively. 
     At step  61 , referring to  FIGS. 4 and 7 , the photoelectric sensors  40  detect an abnormality. More specifically, if the to-be-laminated object  50  is incorrectly oriented such that a rear end  52  thereof (as shown in  FIG. 6 ) is entrained by and wrapped around one of the front rollers  20 ,  21 , or if the heating temperature is so high that the to-be-laminated object  50  adheres to the front rollers  20 ,  21 , the intensity of reflected light received by the photoelectric sensors  40  will change as soon as the to-be-laminated object  50  moves past one of the horizontal centerlines L 1 , L 2 . The photoelectric sensors  40  sense the change of intensity and thus detect the abnormality. 
     At step  62 , the photoelectric sensors  40  immediately alert the operator to the abnormality through light or a warning sound. 
     At step  63 , referring to  FIGS. 5 and 7 , the photoelectric sensors  40  send a signal to the power unit  11 , instructing the power unit  11  to rotate the front rollers  20 ,  21  reversely so as to eject the to-be-laminated object  50 . 
     Hence, according to the present invention, when a to-be-laminated object is curled around one of the front rollers during operation because of an excessively high heating temperature, a wrong inserting direction, or any other reasons, the photoelectric sensors immediately detect the abnormality, provide an alert, and have the front rollers rotated reversely to eject the to-be-laminated object. The major advantage of the present invention is that, while the to-be-laminated object is safely ejected, the motor of the laminating machine is also prevented from burning. 
     The present invention is described herein by reference to the preferred embodiment. However, it is understood that the embodiment is not intended to limit the scope of the present invention, and equivalent or minor changes to the disclosed embodiment are easily conceivable by a person skilled in the art. 
     For example, as the type and size of the laminating machine vary, the rollers may be increased in number or reduced to only one set. In other words, the number of the rollers may be easily changed without departing from the scope of the present invention. 
     Furthermore, the number and locations of the photoelectric sensors may also vary without departing from the scope of the present invention. 
     Therefore, all equivalent alterations and modifications, as well as addition of accessories and change of materials, which do not depart from the concept and scope of the present invention should be encompassed by the appended claims. 
     In short, the present invention is capable of achieving the intended effects, has not been put to public use, demonstrates industrial applicability, and thus meets the requirements of novelty and utility for patent application. Therefore, an application for patent of the present invention is hereby lawfully filed for examination.