Patent GB-953683-A (GB)
Title: Method and apparatus for cutting spirally wound containers
IPC: B31C3/00
Filed: 1962-07-23
Abstract: 953,683. Cutting tubes. ROBINSON & SONS Ltd. July 23, 1962 [July 24, 1961], No. 28239/62. Heading B4B. [Also in Division F2] A method of producing spirally wound containers having a unitary pattern strip spirally wound thereon, comprises the steps of determining substantially the length of a multiple number of patterns wound on a tube, allowing for winding errors by automatically adjusting in a given cycle the spacing of multiple cutting means for dividing the tube into containers until the spacing of the cutters and the patterns are so related that winding errors are parcelled out proportionately among the different containers and then cutting the tube, whereby the excess or deficiency of length of the tube due to winding errors is reduced or eliminated. As shown in Figs. 1, 2 and 3, three mandrels at stations A, B, C, carry laminated paper tubes, the tube 1 from the winding machine being fed on to the mandrel 2 at station A in readiness for movement to station B at which station a tube 3 on the mandrel 4 is ready to be cut into individual containers; at station C a tube 5 in the mandrel 6 has already been divided. The mandrels are indexed from one position to the next by mechanism consisting of a spider 66 rotated on a shaft 65 by a cam-shaft 36 and through bevel gears 61, 62 and an indexing apparatus of known type. Rotation of the mandrels is effected by an electric motor 67 driving a pulley 70 freely rotatable on the shaft 65 and to which is fastened a gear 71 engaging gears 72, 73 and 74 secured to the mandrels. The cutters 7, 8 and 9 are rotatably mounted in frames 10, 11 and 12 slidable lengthwise on a rectangular portion of a bar 13 carried in bearings 16, 17 and resilient compression bushings 19, 20, 21 and 22 located on each side of the cutter frame are also slidable on the bar 13; longitudinal pressure on the bushings tending to shorten the bushings and thereby reduce the spacing of the cutters is effected by an hydraulic cylinder 23 the piston rod 24 of which is connected to a journal housing 18 slidably mounted on the bar 13. Attached to the housing 18 is a lever-operated valve 27 from which depends an actuator lever 28 pivotable about a shaft 52 and able to swing a slotted lever 51 about the shaft, the lever being connected to a vertical spool 39 of the valve and normally held in the lowermost position thereof by a spring 53. An hydraulic source 38a is connected through a pump 38b and relief valve 38c to the inlet port 50 of the valve 27. As shown in Fig. 3, hydraulic fluid can pass through the valve 27 past the spool 39 and into a pipe 41 connected to the inlet port 42 of a valve 43 containing a ported plug 44, the port 42 being out of engagement with the ports in the plug, such " no flow " condition being maintained by a cam lever 46 with an associated cam roller 47 biased by a spring 48 against a rotatable cam 45 on the shaft 36; the ports in the plug 44 are connectible with the cylinder 23 and an exhaust port 54 is connected to the fluid supply 38a. In the other position of the plug 44 the valve connects the cylinder 23 and the valve 27, when the plug has been rotated by the cam 45 and causes the piston rod 24 to retract in the direction of the arrow 30, Fig. 2. When the lever 28 is engaged by the end 32 of the tube 3 the lever 51 raises the spool 39 to cut off passage of hydraulic fluid from port 50 to valve 43, the cutters then being brought into engagement with the tube by a cam lever 33 which is operated in timed relation with the indexing mechanism 64. When the subsequent cutting operation has taken place and the cutters have been withdrawn, rotation of the cam 45 operates the valve 42 so that relaxation of the bushings 19-22 causes the cylinder 23 to be exhausted of hydraulic fluid, the housing 18 moving back to the initial position shown in Fig. 3 and the valve 27 being returned to the open condition thereof. In place of rubber bushings, coiled springs or lever systems can be used and two rubber bushings may be fitted between the cutters if the tube is to be cut into one long and two short containers. In a modification, a photo-cell 101, Fig. 10, and light source 102 is mounted adjacent the cutter 105 which detects a control feature 103 on the tube, and as the cutter carriage 108 moves forward with the tube 104 a spring- loaded finger 118 engages a roller 119 to close contacts A which through a relay energizes a solenoid which operates the plug 44 of the valve 43 to admit fluid to the cylinder 23. After a cutting operation the finger 118 engages a roller 135 to open the contacts C whereby the solenoid operates the valve plug 44 so that the cylinder 23 is exhausted of fluid, the cutter frame 108 being returned to a rearward position in preparation for another cutting cycle.