Patent Publication Number: US-6216760-B1

Title: Adjustable in-plate gluing system

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the field of systems for applying glue, and more particularly to an in-plate hot glue application system for folding machines, which in-plate hot glue application system can be quickly fitted onto any number of folding racks for folding machines and easily adjusted to accommodate a desired hot glue application, even for relatively short folding and glue runs. 
     2. Description of the Prior Art 
     A tremendous volume of printed material is generated and distributed around the world. Much of this printed material comprises sheet material such as printed paper which is folded and which can also be detachably retained in a closed position so that it may be mailed and otherwise handled without inadvertently opening up. For small folding jobs, or for very complicated folding projects, hand folding is often employed. For large volume runs of folded materials, folding machines are used when practical. 
     These folding machines include folding plates or buckle plates, wherein each buckle plate is used to create a single fold in a sheet of material. For example, tri-fold materials are folded using folding machines with two racks. There are several means to retain folded material in a closed position. These means include use of staples, paper and plastic stickers, tear strips, and adhesives, just to name a few. Quick release adhesives have gained popularity for use in detachably holding together folded printed material in a closed position. 
     These quick release adhesives typically comprise hot melt glues which are applied in a heated form and which cool quickly, yet retain elasticity. In their best form, once applied, these hot melt adhesives hold the folded material together well, yet allow the folded pages to be easily peeled apart without damaging the printed material. These hot melt adhesives typically are clear or transparent. 
     The hot glue applicators typically use either an electric or pneumatic applicator, which dispenses the desired quantity of hot glue to the material to be adhered together. Manufacturers of such hot glue dispensers include Robatech, of Switzerland, and the Slautterback Corporation of Monterey, California, among others. 
     Generally, after the printed material is folded, the folded printed material is sent to a different machine to apply the hot melt adhesive. However, it is desirable to simplify the manufacturing process (by eliminating steps) and minimize the need for expensive equipment to the greatest extent possible. The inventor herein is familiar with in-plate gluing systems in which electric adhesive applicators are fixed to a moveable sheet stop of a buckle plate. In such in-plate gluing system, however, since the adhesive applicators are fixed in position to the movable sheet stop of the buckle plate, the position of the adhesive applicators relative to the front of the movable sheet stop and the side to side position of the adhesive applicators within the rack is also not readily adjustable once positioned. 
     Since there is no simple means to provide for adjustability of the adhesive applicators on buckle plates of such in-plate gluing system, it is relatively time consuming to set up buckle plates with adhesive applicators. As a result, buckle plates tend to become set up and dedicated for particular runs. Another issue is cost. Adhesive applicators, the photoelectric eyes used therewith, and the various heated glue hoses and other parts are relatively costly. It would therefore be desirable to have an in-plate gluing system that can be set up easily and quickly, and which can be swapped out to other buckle plates to obviate the need to purchase separate in-plate gluing systems for the sets of buckle plates for each fold and glue job. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide an easy to fit and fully adjustable in-plate hot glue application system for use with folding machines. 
     Another object of the invention is to provide an in-plate hot glue application system which uses a series of slideable brackets and rods to allow the system to be quickly yet securely attached to conventional folding plates for desired folding runs on a folding machine, then reused for printing runs with different requirements, including use on different buckle plates. 
     These and other aspects of the invention are met by providing an adjustable in-plate gluing system for adjustable and detachable use with a buckle plate for a folding machine, the buckle plate having a front, a rear, two sides, and a plurality of spanners spanning the buckle plate, the in-plate gluing system comprising: 
     a rod support bracket means for adjustable attachment to the rear of the buckle plate; 
     a rod for attachment to rod support bracket means; 
     a hot glue applicator bracket means for adjustable attachment to the rod; 
     a hot glue applicator attached to the hot glue applicator bracket means; 
     a photoelectric eye bracket for adjustable attachment to the buckle plate; and 
     a photoelectric eye attached to photoelectric eye bracket. 
    
    
     These and other objects of the invention are set forth below. 
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a first embodiment of an in-plate gluing system of the invention attached to a buckle plate for a folding machine. 
     FIG. 2 is a perspective view of a second embodiment of an in-plate gluing system of the invention attached to a buckle plate for a folding machine. 
     FIG. 3 is a perspective view of a portion of the first embodiment of the in-plate gluing system. 
     FIG. 4 is an exploded view of a portion of the second embodiment of the in-plate gluing system. 
     FIG. 5 is a perspective view of the photoelectric eye bracket. 
     FIG. 6 is a perspective view of the photoelectric eye cable support bracket. 
     FIG. 7 is a perspective view of the rod support bracket. 
     FIG. 8 is a perspective view of the rod support bracket backing plate. 
     FIG. 9 is a perspective view of the hot glue unit support bracket. 
     FIG. 10 is a perspective view of the extension bracket for the hot glue unit support bracket. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring to FIG. 1, a perspective view of a first embodiment of an in-plate gluing system  10  generally designated, is shown mounted to a buckle plate or folding plate  12  for use with a folding machine (not shown.) The buckle plate  12  can be conventional in design and has a front  14 , a rear  16 , sides  18 , a top face  20 , and a bottom face  22 . A number of spanners  44  extend from the front to rear  14 ,  16  of buckle plate  12 . Located along the sides  18  is a drive means  24  with drive belt  26 . Drive belt  26  attaches to a moveable sheet stop  28  to allow sheet stop  28  to be moved between the front and rear  14  and  16 , respectively, of buckle plate  12 . 
     The position of sheet stop  28  determines how far a sheet of material to be folded will slide into buckle plate  12  before it contacts sheet stop  28  and is folded. Located at front  14  of buckle rack  12  are series of feet  30 . These feet  30  can be either fixed in a stationary position, or can be made to be adjustable from side to side in a feet support rail  31 , so that the feet  30  do not ride on glue after it is applied to the sheet material, and the sheet material is withdrawn from buckle rack  12 . 
     In-plate gluing system  10  provides a system to allow hot glue applicator units  32  and photoelectric eye units  34  to be adjusted from side-to-side and from front to rear on conventional buckle plates  12 , independent of the position of sheet stop  28 . In FIG. 1, a single hot glue applicator unit  32  and a single photoelectric eye unit  34  are shown, but it is understood that a plurality of hot glue applicator units  32  and photoelectric eye units  34  can be used on a single buckle rack  12  to accommodate the need to apply multiple points or lines of adhesives to sheet material. Located along the rear  16  of buckle rack  12  is a section of tubing  36 . A section of tubing  38  is likewise located along front  14  of buckle rack  12 . Sections of tubing  36  and  38  are preferably rectangular in cross section. 
     Referring to FIGS. 3 and 5, photoelectric eye unit  34  has a photoelectric eye  40  and a photoelectric eye bracket  42  which is adapted to be mounted to one of a series of spanners  44  that extend between the front  14  and rear  16  of buckle plate  12 , as shown in FIG. 1. A photoelectric eye cable support bracket  46  of FIG. 3 is likewise attached to a spanner  44  to support photoelectric eye cable  48 . 
     Photoelectric eye  40  works in conjunction with hot glue applicator unit  32  to detect the presence or absence of sheet material, so that hot glue applicator unit can be properly timed to dispense the hot glue at the appropriate intervals (for example, either when the paper has stopped moving for spot applications, or when the sheet material is still moving, for application of lines of hot glue). 
     Turning to FIG. 5, a perspective view of photoelectric eye bracket  42  is shown, and has a grip portion  50  for holding photoelectric eye (not shown) and a plate runner contact portion  52 . A bolt  54  (as shown in FIG. 4) can be threaded through aperture  56  to adjustably support photoelectric eye bracket  42  on a spanner  44  at a desired position on buckle plate  12 . Allen bolts or other types of bolts can be used to securely, yet detachably hold support photoelectric eye bracket  42  securely in place. 
     As shown in FIG. 6, photoelectric eye cable support bracket  46  is shown. It preferably has threaded apertures  58  through which bolts  60  (as shown in FIG. 4) can be threaded to support photoelectric eye cable support bracket  46  on spanner  44 . 
     Referring to FIGS. 3 and 4, the hot glue applicator unit  32  is shown attached above top face  20  of buckle plate  12 . Referring to FIGS. 3,  4  and  7 , hot glue applicator unit  32  includes rod support bracket  62  which has clamp end  64  adapted to fix snugly onto tubing  36  at rear of buckle rack  10  (as shown in FIG. 1.) A rod aperture  66  of FIG. 7 is formed through rack engagement bracket  62 . Preferably, rod aperture  66  is not circular in cross-section and rod  78  will have a complementary cross-section so that rod  78  will be slideably in aperture  66  but will not be able to spin or twist in aperture  66 . 
     Bolt holes  68  are formed in rack engagement bracket  58  and receive bolts  70 , as shown in FIG. 4. A rod support bracket plate  72  of FIGS. 3,  4  and  8  preferably has a slot aperture  74  formed therethrough, through which a bolt  76  can be passed through to screw into rod support bracket  62 . This will allow rod support bracket plate  72  to be quickly and securely bolted to a desired position on rear tubing  36  of buckle rack  12 . 
     As shown in FIGS. 1,  3 , and  4 , a rod  78  is sized to slidingly pass through rod aperture  66  in rod support bracket plate  72 . Bolts  80  are threaded into bolt holes  68  to retain the desired position of rod  78  in rod aperture  66  of rod support bracket plate  72 . 
     Other means can be used to slideably, yet securely attach rod  78  to rack engagement bracket  62 . As shown in FIG. 1, a front end of rod  78  will rest on front tubing  38  of buckle rack  12 , and rod  78  will be thusly stabilized. Obviously, the side-to-side position of rod support bracket  62  on buckle rack  12  can be easily adjusted by loosening bolt  76  and sliding rod support bracket  62  on tubing  36  at rear of buckle rack  12 . 
     Referring now to FIGS. 3,  4 , and  9 , hot glue applicator bracket  82  has an aperture  84  sized to receive rod  78 . Bolt holes  86  are formed in hot glue applicator bracket  82  and are adapted to receive bolts  88  to lock the position of hot glue applicator bracket  82  on rod  78  at a desired position. This position can be changed easily. Hot glue applicator bracket  82  likewise has holes  90  for use in attaching hot glue applicator bracket  82  to hot glue valve  92  with bolts  94 . In turn, hot glue valve  92  is attached to hot glue applicator nozzle  96 . 
     Use of a pneumatic valve  92  allows a wider range of viscosities of hot glue to be used, although electric valves can also be used. It is through hot glue applicator nozzle  96  that hot glue will be sprayed downwardly onto sheet material to be folded and adhered together which passes near bottom face  22  of buckle plate  12 . Hot glue supply hose  98  supplies hot glue to hot glue valve  92 . For pneumatic valves, air pressure is used to activate the hot glue valve  92 , and for electric valves, electricity is used to activate the valve. 
     FIGS. 2 and 4 show a second embodiment of the in-plate gluing system  100  of the invention. This second embodiment  100  is almost identical to that of the first embodiment  10  and the same reference numerals identify the same parts and have the same features. Referring to FIGS. 4 and 10, however, an extension bracket  104 , with alignment holes  106 , is used to extend hot glue valve  92  and hot glue applicator nozzle  94  downwardly to be closer to sheet material to which hot glue will be applied. This second embodiment  100  is useful in cases where the buckle plate  102  is thick and/or it is desirable to position hot glue valve  92  and hot glue nozzle  96  closer to the sheet material that would be possible without use of an extension bracket  104 . 
     The various brackets and parts of the system can be conveniently formed of high strength material such as steel, aluminum, or other materials. While the two above described embodiments of the invention make reference to use of bolts to hold the various brackets, rods and units together, other known detachable detachment means can be used as well. 
     The drawings and the foregoing description are not intended to represent the only form of the invention in regard to the details of this construction and manner of operation. In fact, it will be evident to one skilled in the art that modifications and variations may be made without departing from the spirit and scope of the invention. Although specific terms have been employed, they are intended in a generic and descriptive sense only and not for the purpose of limitation, the scope of the invention being delineated in the claims that follow.