Patent IL-28987-A (IL)
Title: Heat-sealing apparatus
IPC: B65B9/087
Filed: 1967-11-21
Abstract: 1,153,779. Packaging machines. J. SALOMON. 14 Nov., 1967 [29 Nov., 1966], No. 53454/66. Heading B8C. [Also in Division B5] A machine for heat sealing a web 53 at spaced intervals comprises a rotatable wheel 14 having a plurality of projecting elements 21 extending radially outwardly from the periphery thereof, a heated arcuate member 24 positioned to extend around a portion of the periphery of the wheel 14 to overlie a plurality of the elements 21 and means for feeding the web 53 between the elements 21 and the member 24. A support table 12 and a cam plate 13 are secured to a vertical shaft 11 of the machine. The wheel 14 secured by spaced tie rods 15 to a plate 16 is rotatably mounted on the shaft 11 and can be driven by a motor (not shown). Each element 21 comprises a pad 22, Fig. 5, of silicone rubber lined with polytetrafluoroethylene which is urged outwardly by a spring 23. The member 24 extends around a 120 degree arc of the wheel 14 and is pivoted at 25 and locked by a clamp 26. A non-heated or forcibly cooled arcuate member 27 is positioned around a further 120 degree arc and is mounted on a pivot (not shown) and secured by a clamp 28. Funnels 29 each having an ellipticalsection stem 30 are each mounted on an arm 31 carried by one rod 15 and urged downwardly by a spring 34. The arm 31 forms one arm of a bell-crank lever the other arm of which carries a roller 32 bearing against a cam surface 33 on the plate 13. The vertical position of each funnel 29 is determined by a cam 35 engaging a portion of the second arm of the bell-crank. A clamp 36 having an inwardly concave clamping plate 37 is urged downwardly by a spring 38 against the action of which a roller 39 running on a cam 40 forces the clamp 36 as the plates 37 enter between the member 24 and the pockets formed by the elements 21. Holes 41 and grooves 42, 43 are formed in the plate 16, one hole immediately above each funnel 29. A radially outwardly sliding shutter 44 is arranged beneath each hole 41. A supply hopper 46 is arranged within a wall 45. In operation, for the formation of tea bags, a web 53 of paper impregnated with a heatscalable resin is fed from a roll 50 over a roller 51 and is longitudinally doubled upon itself to form a channel by a folder plate 82, Fig. 3b, located within a U-section plate 80. In the course of this folding operation, the rotation of the wheel 14 causes the stems 30 to be lowered into the channel and they are allowed by the surface 33 to move radially inwardly towards the wheel 14. Simultaneously, the plates 37 are lowered and brought into contact with the outer wall of the channel of the web by the cam 40 and move inwardly until they are positioned in the packets between adjacent elements 21. The pads 22 wrap the inner wall of the channel against the radially inner surface of the stems 30. As the wheel 14 rotates the pads 22 press the web 53 at spaced apart intervals against the inner surface of the member 24 to transversely heat seal the web. As each funnel 29 enters between the wheel 14 and the member 24, the associated shutter slides radially outwardly to permit a charge of tea to fall into the funnel 29. Scrapers (not shown) feed the tea over the holes 41 and scrape tea out of the grooves 42, 43. Upon further movement of the wheel 14 the cam 35 raises the funnels 29 and the stems 30 withdraw from the web 53 by the time they have reached the downstream end of the member 27 so that tea remains in the pocket. The web is cooled as it passes the member 27 and then passes around a roller 47 driven with a peripheral speed greater than that of the wheel 14 to remove any slack therefrom. A stationary member 47 surrounds a part of the periphery of the roller 47. The top of the web 53 which is still open passes around a disc 48 which presses it against a heated member 49 to heat seal the open edge. The completed web of tea bags is wound on a spool 52. In a modification, Fig. 3a (not shown), the clamp (36) has an outwardly concave plate (37) positioned to face the plate (37). The plate (37<SP>1</SP>) is spring urged inwardly but can be forced out by a cam to clamp the inner portion of the web against the stem 30. In another modification, Fig. 4 (not shown), the plates 37 are omitted and at the point at which the wheel (14) enters the member (24) there is provided a conveyer (60) synchronized with the wheel (14) and provided with projections (61) to force the web between the pads (22).