Abstract:
A low speed, low cost mechanical device for sealing folded product treated with pressure sensitive adhesive into ready to mail documents. Designed as a stand-alone machine powered by a gear motor for small business applications or as a back-up machine for larger users of pressure seal products. The unit can also be used in conjunction with any form folder for a more “automated” system.

Description:
BACKGROUND 
     1. Field of Invention 
     This invention relates to a small, low cost device for the mechanical sealing of pressure sensitive glue treated material, specifically business forms, used as “self-mailing”pieces. The machine can be used “off line” as a stand-alone device for sealing small runs of forms, either as a back up for other larger pressure sealing machines, or as the primary sealer for small businesses. The machine can also be used in conjunction with separate forms folding device for a more automated system. 
     2. Description of Prior Art 
     Until now the cost of pressure sensitive self-mailer forms has limited the market to large volume users. The majority of equipment design has consequently been for high-speed heavy-duty applications. With the advent of competition in the manufacture of pressure sensitive forms, prices per form are now within the range of small volume users. The problem to date in getting small users into pressure seal product has been the high cost of the equipment necessary to seal the product. 
     In addition, a market exists for a back up or emergency machine for existing users of pressure seal forms if their primary sealer is broken, while waiting for service. While users of water activated adhesives can manually apply water via sponges to their documents and users of heat sensitive adhesive can actually “iron” them with an electric iron until service is restored, pressure seal users have no back-up alternative. 
     U.S. Pat. No. 5,540,806 to Traise (1995) discloses a “table-top” sealer for low speed, low volume applications, which utilizes narrow edge rollers and a complex pivoting yoke mechanism. 
     U.S. Pat. No. 5,656,118 to Traise (1997) an improvement to U.S. Pat. No. 5,540,806 still utilizes narrow edge sealing rollers with a cumbersome method of removing and replacing different size bolts to activate/deactivate the sealing pressure. 
     U.S. Pat. No. 5,183,527 to Parker (1993) is a portable “perimeter” pressure sealer, also utilizing narrow edge wheels that seal only the edges of a document. 
     U.S. Pat. No. 5,133,828 (1991) and U.S. Pat. No. 5,211,793 to Jacques (1993) still utilize an edge only sealing method with the addition of complex electronics to reverse motor direction, moving the form forward and back within the sealer. 
     U.S. Pat. No. 5,772,841 to Lindsay (1998) details an “in-line” pressure sealing machine that utilizes two sets of biased rollers to effect product seal. The machine seals the product, which is fed through in the shorter width orientation as delivered from a form folder in line with the sealer. 
     While some of the features of these patents are unique, nevertheless they all suffer from several disadvantages: 
     The small units only seal the edges of the document, one side at a time. 
     The small units require that the form be reinserted in the sealer to seal the opposite edges either manually or through a complicated electronic method. 
     They are expensive to manufacture and consequently expensive to purchase. 
     They all require complicated adjustments to control sealing roll pressure or relief. 
     OBJECTS AND ADVANTAGES 
     Accordingly, several objects and advantages of the present invention are: 
     (a) To provide a pressure sealing device that is mechanically simple and very low cost to manufacture; 
     (b) To provide a pressure sealer that seals the entire document in one pass. 
     (c) To provide a pressure sealer that can be used as a stand-alone unit or used in conjunction with any commercial form folder. 
     (d) To provide a pressure sealer that requires no adjustments to pressure or relief rollers. 
     Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings. 
    
    
     DRAWING FIGURES 
     FIG. 1 shows and exploded isometric of the pressure seal module. 
     FIG. 2 shows a typical safety and cosmetic enclosure. 
     FIG. 3 shows the product flow through the sealer in the lengthwise orientation. 
    
    
     
       
         
               
             
               
               
             
           
               
                   
               
               
                 Reference Numerals in Drawings 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 - left-hand side plate 
                 11 - right hand side plate 
               
               
                 12 - exit plate 
                 13 - bottom plate 
               
               
                 14 - infeed guide plate 
                 15A - front bottom sealing roll 
               
               
                 15B - upper sealing roll 
                 15C - rear bottom-sealing roll 
               
               
                 16 - gear motor 
                 17 - deflector bar 
               
               
                 18 - thrust washers 
                 19 - needle bearings 
               
               
                 20 - motor drive gear 
                 21 - idler gear 
               
               
                 22 - shoulder bolt for securing idler 
                 23A - front bottom sealing roll gear 
               
               
                 23B - upper sealing roll gear 
                 23C - rear bottom sealing roll gear 
               
               
                 24 - infeed tray securing screws 
                 25 - deflector bar securing screws 
               
               
                 26 - motor securing screws 
                 27 - exit panel-securing screws 
               
               
                 28 - roll pins 
                 29 - cosmetic &amp; safety enclosure 
               
               
                 30 - enclosure screws 
                 31 - complete mini module 
               
               
                   
               
             
          
         
       
     
     DESCRIPTION 
     FIGS. 1 to  3   
     A typical embodiment of the mini pressure sealer is shown in FIG. 1 (exploded isometric). The pressure sealer is composed of a right and left hand side frame  10 &amp; 11  typically metal, a front and bottom plate  12 &amp; 13  typically metal, an infeed guide plate  14  typically metal, three pressure rollers  15 A- 15 B&amp; 15 C typically steel, six sealed bearings  19 , five thrust washers  6  typically metal, three drive gears  23 A- 23 B&amp; 23 C typically plastic, one idler gear  21 , typically steel, and one motor gear  20  typically steel. A flex deflector bar  17  typically metal, an AC gear motor  16 , and various mounting hardware. A safety and cosmetic enclosure shown in FIG. 2-29. 
     Typically bearings  19  are pressed into side frames  10  and  11 . Thrust washers  18  are installed on the left and right hand end of pressure rollers  15 A- 15 B&amp; 15 C as required. Pressure rollers  15 A- 15 B&amp; 15 C are pressed into bearings  19  already pressed into side frame  11 . Flex deflector shaft  17  is pressed into side frame  11  and secured with mounting screw  25 . Side frame  10  is placed over the left-hand journals of pressure rollers  15 A- 15 B&amp; 15 C through bearings  19  on that side. Flex deflector bar  17  is aligned with it&#39;s hole on side frame  10  and loosely secured with opposite screw  25 . Side plates  10  and  13  are dropped in milled slots in bottom plate  13  and secured with mounting screws  27 A. Drive motor  16  is installed with the drive shaft protruding through side frame  10  and secured with mounting screws  26 . Motor gear  20  is installed on motor shaft and pined with a roll pin  28 . Idler gear  21  is meshed with motor gear  20  and secured to side frame  10  with shoulder bolt  22 . Drive gears  23 A- 23 B&amp; 23 C are pressed on the ends of pressure rollers  15 A- 15 B&amp; 15 C respectively and pined with roll pins  28 . Infeed guide plate  14  is secured between side plates  10 &amp; 11  with mounting screws  24 . Front plate  12  is secured to side plates  10 &amp; 11  with mounting screws  27 . All screws are tightened. The cosmetic—safety enclosure  29  is placed over the module and secured with mounting screws  30 . 
     The product flow through the mini pressure sealer module  31  is shown in FIG. 3, indicating the lengthwise seal of the product. 
     OPERATION 
     FIGS. 1,  3   
     The present invention is driven by an AC gearmotor  16 , which turns motor gear  20 . Motor gear  20  meshes and turns idler gear  21 , which in turn drives sealer roll gears  23 A- 23 B&amp; 23 C, rotating sealer rolls  15 A- 15 B&amp; 15 C. Product to be sealed is placed on infeed guide  14 . Gravity forces the product into contact with sealer rolls  15 A&amp; 15 B where it is pinched and pulled between them. The product then encounters flex deflector bar  17  that forces it up under pressure roll  15 B and over pressure roll  15 C. The forward motion of the pressure rolls deposits the now sealed product out through the exit hole in front plate  12 , onto a desk or other customer supplied container. 
     SUMMARY, RAMIFICATIONS, AND SCOPE 
     Accordingly, the reader will see that the pressure seal module of this invention is very simple and is significantly less expensive to manufacture than any other pressure sealer presently available. Furthermore, this invention has additional advantages in that: 
     it utilizes a lengthwise placement of the product to form a complete seal; 
     it utilizes a unique “flex” deflector in the three pressure roller station; 
     It utilizes a split capacitor drive that automatically reverses the motor rotation if the stall torque of the motor is exceeded which clears any jams that may occur without manual intervention. 
     Although the description above contains specifications, these should not be construed as limiting the scope of the invention but as merely providing an illustration of one preferred embodiment of this invention. Thus the scope of the invention should be determined by the claims and their legal equivalents, rather than by the example given.