| 摘要 |
<p>1531858 Seaming non-metallic sheet material DOMAIN INDUSTRIES Inc 18 Nov 1976 [3 Dec 1975] 48123/76 Heading B5K A band sealer for scaling filled thermoplastic bags, e.g. of polyethylene, comprises superposed endless heat transfer bands 11, 12 and conveyer chains 15, 16 with adjacent bagengaging and return runs immediately above frame plates 22, the chains 15, 16 being mounted on and driven by motor-driven sprockets 17, 18, the bands 11, 12 being driven from wheels 13 overlying the chains 15, 16, each wheel 13 being journalled in a mounting and coupled to the adjacent chain 15 or 16 so that the bands 11, 12 are driven at the same linear speed as the chains 15, 16. As shown, the sprocket 17 is driven by a motor 24 and drives the sprocket 18 through meshing pinions 17À2, 18À2. Chain guides 28, 29 are mounted on the plates 22 to guide the bag-engaging runs 15À1, 16À1 of the chains 15, 16 along the sides of a slot 20 defined by the plates 22. The guide 29 is slightly movable or spring-pressed to accommodate different bag thicknesses. Heat transfer bars 11À3, 12À3 extending along the bag-engaging runs 11À1, 12À1 of the bands 11, 12 supply, or withdraw heat from the bands and may be heated by electrical resistance heaters or cooled by chilled water. Each wheel 13 has a ring gear 30, fixed to the inside of a peripheral wall 13À6 thereof, and with which meshes a pinion 31 on a sprocket 32 meshing with the return run 15À2 or 16À2 of the chain 15 or 16. The runs 15À2, 16À2 are maintained in mesh with the sprockets 32 by guides 33 on the plates 22. Brackets 34, mounting the wheels 13, the pinions 31 and the sprockets 32, define stub shafts 34À1 extending into bearings 13À3 of the wheels 13 and have cantilever portions 34À4 in which are fixed shafts 35 extending through bearings 32À1 of the sprockets 32. Each bracket 34 is on the adjacent plate 22 by a fulcrum pin 36 and fixed thereto by screws (37), Fig. 3 (not shown), adjustable to alter the orientation of the respective wheel 13 so that the band tracks properly. Each wheel 14 is mounted on a slide 38, Fig. 5, movable by swinging a cam 38À1 upwardly against the end of the slide against the pressure of a spring 38À2 to move the wheel 14 slightly towards the wheel 13 to loosen the band for replacement thereof. The space immediately above the wheels 13 is open to facilitate this replacement.</p> |
