Portable mechanical device for sealing material treated with pressure sensitive glue

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.

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.

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 & 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&11 typically metal, a front and bottom plate 12&13
 typically metal, an infeed guide plate 14 typically metal, three pressure
 rollers 15A-15B&15C typically steel, six sealed bearings 19, five thrust
 washers 6 typically metal, three drive gears 23A-23B&23C 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 15A-15B&15C as required. Pressure rollers 15A-15B&15C 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
 15A-15B&15C through bearings 19 on that side. Flex deflector bar 17 is
 aligned with it'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 27A. 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 23A-23B&23C are
 pressed on the ends of pressure rollers 15A-15B&15C respectively and pined
 with roll pins 28. Infeed guide plate 14 is secured between side plates
 10&11 with mounting screws 24. Front plate 12 is secured to side plates
 10&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 23A-23B&23C, rotating sealer rolls 15A-15B&15C.
 Product to be sealed is placed on infeed guide 14. Gravity forces the
 product into contact with sealer rolls 15A&15B where it is pinched and
 pulled between them. The product then encounters flex deflector bar 17
 that forces it up under pressure roll 15B and over pressure roll 15C. 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.