Patent GB-1354544-A (GB)
Title: Wrapping machines
IPC: B65B35/24
Filed: 1971-04-19
Abstract: 1354544 Wrapping machines SCANDIA PACKAGING MACHINERY CO 19 April 1971 [9 April 1970] 26027/71 Heading B8C A wrapping machine comprises cutting means to form in a web of wrapping material, two perforations 32, 33, Fig. 3, extending longitudinally and a perforation 31 that crosses the two perforations, means for joining a tear strip 10 to the wrapping material so as to extend between the longitudinal perforations, means 40, Fig. 1, for moving a package from a package supplying work station to a wrapper applying station, Fig. 1, the moving means 40 including primary and auxiliary pushing means 42, 43, Fig. 10, shifting means 62, Fig. 14, at the wrapper applying station for adjusting the position of the wrapping material after being contiguously placed on the package, means 53, Fig. 10, for receiving the package after a wrapper has been applied across the advanced end and two opposite sides of the package, the primary pushing means being effective to urge the package into the receiving means and the auxiliary pushing means being effective to seat the package within the receiving means, sensing means (49), Fig. 9 (not shown), located before the receiving means 53 to detect an irregular feed condition of a package, first means responsive to the sensing means to stop the moving means, heat-sealing means 87, Fig. 22, located adjacent the receiving means 53 at a heat sealing station, and second means responsive to a shut down condition of the machine to move the heat-sealing means away from a package and the receiving means to prevent burning of the package. As shown, tearstrap wrappers are produced on an assembly 124, Fig. 2, in which wrapper material 18 is formed with a slit 31 by means of a rotary cutter 21 prior to the application of a tear-strip ribbon 10 which is fed over a solvent applicator 15 and through a heater 16 to a pressure roller 22 where the ribbon is glued to the material 18. A cutter 24 then produces the perforations 32, 33 and a cutter covers the ribbon at a perforation 34. The material is subsequently cut into sheets by a rotary cutter 29. The package is moved along a platform (73), Fig. 9 (not shown), by the pushing means 42, 43, Fig. 10, which comprise members fixed to a pair of driven chains 41, and urging the package into the receiving station 53 which comprises a turret wheel assembly having pocket members 54, 55 and a folding platform 56 which provides a support for the lower part of a wrapper sheet and an edge over which a projecting end (58), Fig. 11 (not shown), of the sheet is folded by the pushing members 42, 43. Adhesive is applied by a wick (61), Fig. 13 (not shown), to the end (58) for subsequent joining of ends 57 and (58). The shifting means 62, Fig. 14, is associated with the moving means 40 and comprises a control member 63 extending transversely to the direction of movement of the package along a platform 73. A shaft 64 is attached to a lever 65 which pivots about a pin 66 connecting the lever 65 to the platform 73, the pivoting movement of the lever 65 being effected by a rod assembly 67, the arrangement being such that the member 63 is effective to grip and skew the wrapper sheet at the one side of the package before the wrapper has been folded thereon, the degree of control by the member 63 being adjustable by pivoting action of the member 63 about the pin 66 by means of the assembly 67. The sensing means (49), Fig. 9 (not shown), in the form of a roller opens a switch (51) as a package passes thereover and a cam switch (80), Figs. 16 and 17 (not shown), operated by a cam (81) driven by the drive to the chains 41, opens and closes in synchronism with the switch (51), such that one or the other of the switches (51), (80) is closed under normal package feed conditions. Under abnormal package feed condition as in for example Fig. 16 (not shown) both switches remain open. The two switches are wired in a circuit, Fig. 17 (not shown), controlling a drive circuit (85) for the chains 41 such that the latter are stopped when both switches (51), (80) are held open. Switches (51), (80) are supplemented by a switch (82) controlled by a clutch in the drive for the chains 41 effective to prevent operation of the machine under fault conditions. In this connection, the heat-sealing means 87, Fig. 22, comprises a heater element (102) Fig. 25 (not shown), and a micro-switch 86 actuated by an oscillating cam 92 in response to movements of the heater (102). The heat-sealing means forms part of a mechanism which includes levers 88, 89 for operating the heater (102) and a folder member (103). The switches (51), (80), 86 are associated with circuitry, Fig. 27 (not shown), which includes start and stop switches (105), (104) for the machine motor and start and stop switches (111), (123) for the machine drive; energization of a coil (112) closes a contact (115) in a circuit which includes the switch 86 and a timer (117). A relay (85) controls contacts (108), Fig. 27 (not shown), in the machine drive circuit and such that under normal package feed conditions contacts (108), (114) are closed. If either or both contacts (114), (115) opens through operation of switches (104) or (123) or through abnormal operation of switches (51), (80), the machine will continue the run until the heater (102) and member (103) have been moved away from the package, when the switch 86 is opened by the cam 92. Specifications 1,354,545, 1,354,546, 1,354,547 and 1,354,548 are referred to.