Abstract:
A laminating machine for making sheet laminations using a thermal laminating film is disclosed which protects the film from being mounted in the machine in a manner that will expose its adhesive side to the heated laminating rollers in the machine. The film is stored on upper and lower supply rollers in the machine. Each supply roller is engaged at one end by a forward end of a rotatable piston disposed in a variable-length spring operated chuck. A stem attached to the forward end of the piston extends rearwardly from the forward end and away from the roller into a cylindrically enclosed body portion of the chuck. There the stem is engaged by a one-way needle bearing which permits the film to be unwound from the supply roller only in one direction, thus permitting only the non-adhesive side of the film to contact the machine&#39;s heated laminating roller.

Description:
This is a non-provisional application which claims the filing date of the same inventor&#39;s provisional application Ser. No. 61/632,539, filed in the United States Patent and Trademark Office on Jan. 26, 2012. 
     This invention relates to improvements in machines for covering pages of copy material with film by encasing them between layers of film. More particularly, it relates to introducing upper and lower layers of laminating film wound on supply rollers into a laminating machine easily in registration with each other and insuring that the adhesive layers of the laminating film on each of the rollers does not contact the heated film laminating rollers in the machine as the film from each laminating film supply roller is unwound. 
     Except for the provisional application just referred to, there are no patent applications related to this one. This application is not subject to any federally sponsored research or development or to any joint research agreement. The inventor in this application is also the inventor of the invention in U.S. Pat. No. 7,874,340 entitled “Laminating Machine.” 
     BACKGROUND OF THE INVENTION 
     Prior to the improvements described in this application, a laminating machine known as “GBC Ultima 65 School Laminator” was promoted by General Binding Corporation in their 2001 Bulletin No. 1630371 3MO202, copyright 2001. A large number of the machines described in that brochure have presumably been in use in schools and offices which require sheet laminating equipment. 
     However, correctly threading the films from the film supply rollers has proved difficult for many classroom instructors, especially in aligning the webs of film with each other as they are inserted into the machine and thereafter placing them on the heated laminating rollers without having the adhesive coated side of the film contacting those rollers. 
     SUMMARY OF THE INVENTION 
     The present invention is embodied in a laminating machine which has upper and lower laminating rollers with outer surfaces rotatably moving toward each other at a nip between them. There are also upper and lower laminating film supply rollers from which webs of film extend onto the laminating rollers and are drawn through the nip. An object to be encased in laminating film is inserted between the webs of film at the nip and is encased there as the object, sandwiched between the upper and lower films, is drawn through the nip. The laminating film, which has a non-adhesive polyester layer and an adhesive polyethylene layer, is placed with its adhesive side on the object where it is fastened onto the object as the object and film pass the nip. First and second frame members support the laminating rollers and the film supply rollers. Each of the laminating film supply rollers has a socket formed at one end so that a spring-loaded chuck, affixed on one of the frame members, may be engaged in the socket when the supply roller is installed in order to position and support the supply roller on the frame. 
     Downstream from the heated laminating rollers, draw rollers (not shown) pull the laminating films around the heated laminating rollers and through the nip between them. 
     A rotational direction member is engaged on the chuck member and restricts it, and the supply roller in which it is engaged, to rotation only in a single direction. Thus restricted, the laminating film supply roller unwinds the film only with the adhesive layer facing away from the heated laminating roller so that it does not contact that roller as the film passes around it. 
     From the foregoing, and from the detailed description which follows, it will be apparent that the laminating machine described herein allows a classroom instructor or secretarial person to quickly and successfully replace supply rolls of laminating film. 
     It is one object of this invention to provide a laminating machine in which installing films from the upper and lower laminating film supply rollers on the machine&#39;s heated laminating rollers is accomplished correctly and rapidly. 
     It is a further object of this invention to provide a laminating machine in which the installation of the film can only be accomplished in a manner which insures that the adhesive layer of the film directly engages an object being laminated. 
     It is a further object of this invention to provide a laminating machine in which the installation of the upper and lower laminating film supply rollers may always be accomplished by relatively unskilled personnel. 
     It is a further object of this invention to provide a laminating machine in which installation of the laminating film supply rollers will always be accomplished in a manner which avoids the possibility of unwinding a supply roller with the adhesive layer of the film disposed to contact the heated laminating roller of the machine. 
     Other objects and features of this invention will be apparent to those persons who are skilled in the practical art of designing and using machines for enclosing sheets of materials such as paper between laminating films, particularly after reviewing the following description of the preferred embodiments of the present invention and the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded view of elements of the laminating machine of this invention illustrating the initial positions of the upper and lower laminating film supply rollers as those film supply rollers are ready to be mounted between the side frames of the machine and held in place by chuck assemblies in one of the side frames as the film supply rollers are ready to be unrolled. 
         FIG. 2 . is an enlarged perspective view of a chuck assembly of this invention. 
         FIG. 3  is a sectional view of the chuck assembly of  FIG. 2 , taken along the line  3 - 3  in  FIG. 2 . 
         FIG. 4  is a sectional view of the chuck assembly in  FIG. 3 , taken along the line  4 - 4  in  FIG. 3 . illustrating a cross section of a one-way needle bearing disposed around a trailing stem portion of a piston in the chuck assembly of  FIG. 3 . 
         FIG. 5  is an enlarged, perspective view of the one-way needle bearing shown in the chuck assembly in  FIGS. 3 and 4 . 
         FIG. 6  is an enlarged diagramatic view of a portion of a web of laminating film from the upper laminating film supply roller passing under an idler roller and around a heated laminating roller in the laminating machine of this invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Elements of the improved laminating machine  10  of this invention are shown in perspective in  FIG. 1 . An upper laminating film  12  is shown wound around upper laminating film supply roller  14 , and the roller  14  is shown in position to be installed in the machine  10  between side frames  16  and  18 . The path of film  12 , as shown in  FIG. 5 , extends below an idler roller  20  and around a heated upper laminating roller  22 . A lower laminating film supply roller  24  which carries a supply of lower laminating film  26  is shown in position to be installed in the machine  10  between the side frames  16  and  18 . The path of the lower laminating film  26  is similar to the path of the upper laminating film  12  except that lower laminating film  26  extends around heated lower laminating roller  28 . The upper laminating film  12  and the lower laminating film  26  meet at a nip  30  between the heated upper laminating roller  22  and the heated lower laminating roller  28 . An object to be laminated (not shown) is inserted between the upper laminating film  12  and the lower laminating film  26  so that it is sandwiched between the upper and lower films as they pass through the nip  30 . The heated laminating rollers  22  and  28  are heated electrically to about 240 degrees Fahrenheit so that they are hot enough to soften the films  12  and  26  and cause them to adhere to the object being laminated, as will be described below. 
     The step of installing the supply rollers must be capable of being done by a classroom instructor or secretary without having to call an assistant. Moreover, after the supply rollers are installed in the laminating machine, threading the films on them onto and between the heated laminating rollers must be accomplished smoothly without requiring an operator to bring his hands close to or touch the heated laminating rollers. One such manner of installing the films is described in U.S. Pat. No. 7,874,340, but other procedures may be used. Whatever procedure is employed, it is important to be sure that the adhesive layer of the film is not brought in contact with the heated rollers. 
     Thermal laminating films normally have two layers, a polyethylene layer which is an adhesive, and a polyester layer which is a film layer. When such laminating films are wound on a supply roller, it is important to install the supply roller in the laminating machine so that as it is unwound the polyester layer is the one which contacts the heated laminating roller, not the polyethylene layer. One manner of insuring that the layers are properly oriented is to restrict unwinding the film from the laminating film supply roller to one direction only. The variable-length chuck in the present invention is constructed so that the piston member in the chuck can only rotate in a single direction, and thus, the laminating film supply roller which the piston engages is only permitted to unwind when the laminating film on the supply roller has its polyethylene side facing away from the heated laminating roller and onto the object being laminated. 
     In the laminating machine of this invention, the laminating film supply rollers  14  and  24  are held in place between the frame members  16  and  18  by variable length spring-loaded chucks at one end and fixed length chucks at the other end. In  FIG. 1 , the variable length chucks are shown at  32  for the upper laminating film supply roller  14  and at  34  for the lower laminating film supply roller  24 . Variable length chuck  32  is shown in enlarged perspective in  FIG. 2 , and since variable length chuck  34  is identical except for the direction in which the piston inside rotates, chuck  32  may be taken as typical. 
     Chuck  32  includes a stem member  36  which is slidably disposed in a cylindrical body  38 . An abutment  40  is located in one end of the cylindrical body  38 , and a pin  42  extends through the abutment to engage the stem  36 . Inside the cylindrical body  38 , a coil spring  44  surrounds the pin  42  and at one end engages the abutment  40 . Opposite that engagement on abutment  40 , the coil spring&#39;s other end may be affixed to pin  42 , or it may extend far enough to engage stem  36 . Pin  42  extends slidably through the abutment  40  so that when the stem  36  is moved inside the cylindrical body  38  toward the abutment  40 , stem  36  will compress spring  44  against the abutment  40 . A portion of pin  42  inside the spring  44  will be forced on through the abutment  40  and move beyond the abutment. When pressure on the stem  36  is relaxed to the point that spring  44  can expand, stem  36  will be moved in a direction away from the abutment  40 , and much of pin  42  will be brought back inside the cylindrical body  38 . 
     At the other end of stem  36 , outside the cylindrical body  40 , a chuck head portion  46  is formed which fits into an open end of a tubular core, or similar engagement dock, forming a socket portion  48  in the end of the upper laminating film supply roller  14 . Together, stem  36  and the head  46  form a piston which moves back and forth in the cylindrical body  38  of chuck  32  against the coil spring  44  and positions the chuck head portion  46  firmly in the socket portion  48  of supply roller  14 . 
     The spring-loaded chuck  32  is mounted on frame member  16 , as shown particularly in  FIG. 1 . Chuck  32  may be held in place there by bracket  50 . A fixed-length chuck  52  is mounted in frame member  18  opposite the location of chuck  32  and is engageable in a second socket portion on the other end of the upper laminating film supply roller  14  which is similar to socket portion  48 . When it is necessary to change the upper laminating film supply roller from an old one to a new one, an operator pushes the roller to be removed axially against the variable-length chuck  32  until the end of the supply roller engaged on the fixed-length chuck is freed from that chuck and can be lifted from it. Thereafter, the end of the old supply roller engaged on chuck  32  may be freed from chuck  32  and that roller removed from the laminating machine and either be thrown away if it is spent, or stored if it still has film. 
     Installing a fresh upper laminating film supply roller, for both the upper and lower film supply rollers, is quite similar to the removal steps just described. Thereafter, the films from either or both of the supply rollers are threaded between the heated laminating rollers. One manner of threading the films is described in U.S. Pat. No. 7,874,340, though other procedures may be used. As noted previously, it is important to avoid having an operator&#39;s hands touch the heated laminating rollers. An appropriate tool may be used to press the ends of the upper and lower films between the laminating rollers, but the threading process is increasingly difficult if the films should become adhesively stuck on the heated rollers. Even if the films do not immediately adhere to the heated rollers, the same adhesive problem may occur later during successive laminating activities. 
     The present invention avoids the myriad aspects of permitting the adhesive layer of a thermal laminating film coming in contact with the heated laminating rollers of a laminating machine by making it impossible for a supply roll of laminating film to be installed incorrectly. Viewing the upper laminating film supply roller as typical, a rotational direction member is installed in chuck  32  which limits rotation of that chuck to one direction, and consequently the upper laminating film supply roller  14  is limited to unrolling only in one direction. The result, assuming that the manufacturer of the film  12  wound it correctly on roller  14 , is that the film  12  will only unwind with its upper layer  56 , which is the adhesive layer, facing away from upper heated laminating roller  22  as the film passes that heated roller. The lower, non-adhesive layer  58  of film  12  is the only layer of film  12  which contacts roller  22 . A like rotational direction member (not shown) is installed in the chuck member  34  to limit film  26  to unrolling with its adhesive side  60  (see  FIG. 1 ) facing away from the lower heated laminating roller  28  as film  26  passes that heated roller. The non-adhesive layer  62  of film  26  is the only layer of film  26  which contacts roller  28 . The path of the upper laminating film  12 , including its adhesive and non-adhesive sides is illustrated in  FIG. 6 . 
     One form of a rotational direction member  54  is the one-way needle bearing shown in  FIGS. 3 ,  4  and  5 . That bearing includes a circular collar portion  64  which forms a bearing cage for the cylindrical bearing rollers  66 . Member  54  is disposed inside the cylindrical body  38  of chuck  32  and encircles the stem member  36  of the piston formed by stem  36  and head portion  46  in chuck  32 . Another rotational direction member (not shown) which may be a duplicate of the member  54 , except that it limits rotation of the lower laminating film supply roller  24  to presenting the adhesive layer  60  of film  26  to meet the adhesive layer  56  of film  12  at the nip  30  between upper and lower heated laminating rollers  22  and  24 , is contained in lower chuck  34 . 
     From all of the foregoing it will be evident that, although particular forms of the invention have been illustrated and described, nevertheless various modifications can be made without departing from the true spirit and scope of the invention.