Patent GB-1154221-A (GB)
Title: Improvements in or relating to Packing Machines
Inventor: WAHLE GUENTER
IPC: B65B51/16
Filed: 1966-01-04
Abstract: 1,154,221. Packing-machines. HAUNIWERKE KORBER & CO. K.G. 2 Nov., 1966 [4 Jan., 1966], No. 299/66. Heading B8C. [Also in Division B5] A sealing device in a packaging machine is provided with heating means the effective temperature of which is adapted to be controlled dependently on the operating speed of the packaging machine. In one embodiment, Figs. 1 and 3, two cigarette packing machines 2, 4 are each provided with a single speed drive motor 6, 8 and supply cigarette packages to a transparent film wrapping machine 10 having a two-speed drive motor 12 which is in full operation when both machines 2, 4 are in operation and runs at half speed when only one machine is in operation. A relay 34 having contacts 36, 38 is provided to change the motor 12 from full speed to half speed and vice versa. In operation, when both machines 2, 4 supply packages to the machine 10, sensing devices 40, 42 maintain the relay 34 energized with its contact 38 closed and its contact 36 open. Simultaneously, an electromagnet 64 is energized and holds, against the action of a spring 76, a rack 66 in the position shown in Fig. 3, so that through the co-operation of a pinion 68, a shaft 70, a gear-wheel 72 and a rack 74, a heater member 78 lies with an electrical heater element 90, which is switched on by the relay 34, in front of an open side of a duct 80. Wrapped packages 86 slide through the duct 80 with the longitudinal side flaps of their wrappers along the region of the member 78 so that the element 90 welds these flaps. If one of the machines 2, 4 is out of operation or a disturbance occurs, the associated sensing device 40, 42 closes either a switch 48 or a switch 52 to de-energize the relay 34 so that its contact 36 closes and its contact 38 opens and the motor 12 is reduced to half speed. Simultaneously, the electromagnet 64 is de-energized so that the spring 76, through the co-operation of the rack 66, the pinion 68, the shaft 70, the gear 72 and the rack 74 moves the member 78 so that an electrical heater element 92 lies in front of the open side of the duct 80. As the element 92 is moved into its operative position it is switched on by the relay 34 and as the element 90 moves out of this position it is switched off by the relay 34. The element 92 is designed to give the same effective heat output in twice the, time as the element 90. As soon as both machines 2, 4 return to normal operation, the device 40 or 42 energizes the relay 34 so that the motor 12 changes over again to full speed and the element 90 moves into the operative position. In a second embodiment, Fig. 6, wrapped cigarette packages (not shown) pass intermittently through a stacking duct (not shown) at one side of which three heater members 214, 216, 218 are located. Each member 214, 216, 218 comprises two semi-cylindrical thermostatically-controlled heater elements 220, 222 heat insulated from each other by an intermediate plate (224), Fig. 5 (not shown), the elements 222 being used for full speed operation of the machine and the elements 220 for half speed operation to give the same heat output. In operation, when the wrapping machine is changed from half to full speed an electromagnet 254 is energized and displaces a rack 252 which rotates the members 214, 216, 218 through 180 degrees so that the elements 222 are in operative position. This rotation is effected by a pinion 250, a shaft 248, bevel gears 244, 246, a hollow shaft 230, gear-wheels 238, 240, 242 and hollow shafts 232, 234. If the machine is changed to half-speed, the electromagnet 254 is de-energized and the rack 252 is returned by a spring (not shown) so that the members 214, 216, 218 are rotated through 180 degrees in the opposite direction to bring the elements 220 into the operative position. The members 214, 216, 218 may be withdrawn from the packages between the heating periods by movement in the direction of the arrow 270. This movement may be cam controlled and is guided by bars 264 on a housing 236 which bars engage in a slot 266. Fig. 7 shows a portion of the packing track of the machine 10 of Fig. 1. Wrapped cigarette packages 300 are conveyed between rails 306, 308 in the direction of the arrow 304 by a belt 302. A heater member 310 to seal end flaps of the package is located in a gap in the rail 306 and comprises heater elements 314, 316 separated by an insulating plate 312. A scraper 326 extends along the member 310 to clear the member. The member 310 is secured to a shaft 328 provided with a pinion 334 which engages a rack 336 reciprooable by an electomagnet (not shown) and a spring (also not shown). The device operates on the same principle as that of Fig. 6 to position one of the elements 314, 316 in operative position according to the operating speed of the machine. A further heater member may be positioned in a gap in the rail 308 either directly opposite to the member 310 or at a subsequent location. In a further embodiment, Fig. 8 (not shown), a single electrical heater (400) is provided and is fed by a transformer (402). When the machine changes from full to half speed, the voltage applied to the transformer is reduced to reduce the temperature of the heater so that the effective heat output thereof remains constant in spite of the lengthening of the effective heating period. In a modification, Fig. 9 (not shown), two heater elements (500), (502) are provided and are used for full and half speed operation, respectively, of the machine. In a further modification, Fig. 10 (not shown), two heater elements (600), (602) are provided and both are used for full speed operation but only the element (602) for half speed operation. In another embodiment, Fig. 11 (not shown), an electrical heater element (700) is controlled dependently upon the speed of the machine by a tachometer generator (702) driven from main shaft (718) of the machine.