Patent GB-811537-A (GB)
Title: Method and machine for applying film to a base sheet
IPC: B44C1/16
Filed: 1956-12-28
Abstract: 811,537. Laminating. MEYERCORD CO. Dec. 28, 1956, No. 39432/56. Class 140. [Also in Groups XV and XXIV] A laminating apparatus comprises a pair of feed rolls, one of which is heated, a pair of compressible pressure rolls mounted adjacent to said feed rolls and surfaced with resilient material, and a second heating means interposed between said feed rolls and said pressure rolls. As shown, the apparatus is supported on a pair of standards 14 and 16, united at the top by a pair of cross-bars 17. Stationary bearing supports 18 are rigidly mounted on the standards 14 and 16 to journal a bottom feed roll 19 with a rubber traction surface. Similar supports 21 journal a bottom delivery roll 22 of rubber. Vertically movable bearing boxes 23 are carried on the standards 14 and 16 to mount an upper feed roll 24 which coacts with the roll 19 and an upper delivery roll 26 which is similar to the roll 22 and coacts therewith. The roll 24 is a hollow metal roll having a plurality of internal electric heating elements which are connected through one end of the roll to suitable electrical conductors contained in a flexible conduit 27. A radiant heating unit 28 is located between the two pairs of rolls. The work may thus be fed from a feed-table at the front of the machine between rolls 19 and 24 which are power-driven, at least in part, then beneath the radiant heater 28, between pressure rollers 22 and 26, and on to a work-receiving table at the rear of the machine. Each of the bearing boxes 23 comprises a pair of parallel inner and outer plate members 57 and 58 disposed closely adjacent to the standards 14 and 16. The plates 57 and 58 are interconnected by transverse plates 59 and 61 thereby defining a central opening of rectangular cross-section through which the corresponding standard 14 or 16 extends. The plates 57 and 58 extend beyond the standards in both directions to define pairs of box-like bearing enclosures. At the front of each bearing box a bearing housing for the roll 24 is formed by plates 62, 63 and 64 which are bolted to each other and to the plates 57 and 58. At the rear of each bearing box a similar bearing housing for the roll 26 is formed by plates 66, 67 and 68. The rolls 24 and 26 are journalled in bearing blocks 71 and 82 respectively which are keyed to permit limited vertical sliding in their housings. The upper portion of each bearing block is formed with a cylindrical recess to receive a helical spring 77 or 86 which is seated therein and is compressed by a pressure screw 78 or 88 which carries a thrust member 79 or 87 at its lower end, is threaded through plate 63 or 67, and carries a handle 81 or 89 at the upper end for varying the degree of compression. The electrical conductors from the conduit 27 to the heaters in roll 24 extend through a hollow shaft (not shown) through the journal bearing. To prevent rotation of this hollow shaft a square collar 93 is rigidly mounted on the hollow shaft and has a depending bar 94 which extends between two spaced rods 96 which project from the bearing box 23. The bearing boxes 23 are mounted on channel members 98 which are rigidly bolted to the outer plates 58 of the bearing boxes and are received within the outermost channel portions of the H section of the standards 14 and 16. The upper end portions of the channel members have bolted thereto elongated hanger rods 101 threaded at their upper ends which project above the standards 14 and 16 and engage with an adjusting mechanism for raising or lowering the boxes 23. The lower portions of the channel members 98 have slots 103 and bolts carrying slide blocks 106 project therethrough and into the standards to ensure alignment of the channel members with the standards. The adjusting mechanism for raising and lowering the hanger rods comprises a pair of worm-gear boxes 107 and 108 mounted on the cross-bars 17. Both of these boxes have apertures at the top and bottom to permit the hanger rods to pass through them. A worm gear 109 is supported on each of the threaded portions of the hanger-rods by means of a bushing 110 rigidly secured to the upper side of the worm gear and having a threaded bore engaging the thread on the hanger rod. A thrust bearing 111 is placed between each worm gear and the bottom of its box. A shaft 112 extends between the two boxes 107 and 108 and is journalled therein. Worms carried on shaft 112 engage the worm gears 109, and a hand wheel 116 is affixed to the shaft to rotate it manually and so operate both worm gears simultaneously. The shaft 112 is made in two pieces joined by a coupling 117. This coupling may be loosened to raise or lower one of the bearing boxes 23 without the other and then retightened. A sliding wedge arrangement is provided at each end of roll 24. An upright lifting stud 121 may be adjusted to project above the plate 64 to act as a stop for the bearing block 71. A rectangular channel track housing 122 is welded below the plate 64. A wedge member 127 slidably engages the lower surface of the stud 121 and is slidably mounted within the channel track in the housing 122. A screw 131 extends into the housing 122 and engages a threaded bore in the wedge 127. The outer end of screw 131 carries a rigid thrust member 133 which coacts with the plate 134 secured to the sides of channel 122, and has a hexagonal head 136 for manually adjusting the screw. Each of the feed and delivery rolls is driven by means of an electric motor 137 through a chain and sprocket drive. The motor 137 is mounted on a base 138 having depending flanges 139 which are slidably supported on two rods 141 extending between spaced supports 142. A rod 143 is journalled between the supports 142, and a threaded portion engages threaded holes in the dependent flanges 139. The outer end of rod 143 is journalled in a bracket 144 and has secured thereto an operating wheel 146 so that by rotating the rod 143 the motor 137 can be moved to vary the drive ratio and speed of the rolls. This is achieved in known manner through a variable speed pulley 147 on the motor shaft, the driving diameter of the pulley being self-adjusting as the motor is moved. A belt extends round the pulley 147 and a larger pulley 149 and so drives reduction gearing in a gear-box 151. A drive shaft 152 projects from this gear-box and carries a sprocket 153 which engages the chain 154. This chain passes over two idler sprockets 156 and 157, thence over two sprockets 158 carried on the pressure rolls 22 and 26, over another idler sprocket 159 and thence over two larger sprockets 161 carried on the feed rolls 24 and 19 and back to the drive sprocket 153. An overrunning clutch 162 is provided for the heated feed roll 24, the sprocket 161 being mounted on a projecting sleeve portion (not shown) of the clutch 162. The idler sprockets may be adjusted to maintain a predetermined chain tension in spite of vertical movement of the upper rollers. The uppermost idler sprocket 159 is carried on a stud 163 which is mounted on a bracket arm 164 secured to the cross-bars 17 at the top of the frame. The bracket arm 164 has a slot 166 so that the stud 163 can be moved up or down and tightened in any desired position thereon. An inverted T-shaped cam lever 167 is secured adjacent to the outer end of the cross-bar of the T to a pivot shaft 168 which extends across the frame of the machine and is journalled in the brackets 46. Sprocket 157 is also carried on the end of this shaft 168. Sprocket 156 is rotatably mounted at the opposite end of the cross-bar of the cam lever 167. The outer end of the upright portion of the cam lever has a rounded cam surface which bears on a cam plate 171 secured to the channel member 98. This cam plate is so shaped that as the channel member 98 is moved up or down the sprocket 156 is moved up or down to maintain the tension in the chain. The radiant heating unit 28 between the feed and delivery rolls comprises a U-shaped insulated reflector with a plurality of electrical radiant heaters 174 mounted within it. This heating unit is suspended between the inner walls of the bearing boxes 23 by means of a pair of bracket plates 176 which are fastened to opposite ends of the top of the unit and are supported on the horizontal flanges 177 of adjustable brackets 178 by means of saddle straps. Each bracket 178 has a slot 180, and a stud 181 carrying a collar 182 extends through the slot into the wall 57 of the bearing box. An adjusting screw is threaded through a horizontal upper flange of the bracket 178 and engages the collar, to adjust the height of the heating unit. A guard below the heating unit prevents the work coming into direct contact with the radiant heaters if it becomes buckled. This guard is in the form of a comb comprising a shaft 187 and a plurality of fingers 188. The shaft 187 is suspended from the flanges 177 by means of tubular collars. Two idler rolls 191 are journalled in brackets 192 secured to the standards 14 and 16 and support the work as it passes between the feed and pressure rolls. A rock shaft 193 extends across the front of the upper feed roll 24. A guard member 194 is secured to and hangs from it in front of the nip between rolls 19 and 24. A microswitch mechanism 197 is so arranged that if the operator's hand enters the nip of the rolls the guard member is moved back and the microswitch reverses the direction of rotation of the rolls. A shoe 203 is mounted above roll 24 and carries a heatsensitive element 204 which engages the surface of the roll, whereby to control the temperature of the roll through known temperature control mechanism. This apparatus may be used to laminate a relatively fragile film, e.g. a decalcomania to a rigid base sheet of e.g. wood or " Masonite " (Registered Trade Mark) having a thermoplastic surface coating, the thermoplastic-coated surface having surface irregularities, e.g. those commonly found at the edges of panels after sanding. The fragi