| 摘要 |
<p>1,270,458. Tensioning webs. BELOIT CORP. 26 June, 1969 [13 Sept., 1968], No. 32428/69. Heading B8R. [Also in Division D2] A device for tensioning a web, e.g. an endless belt of felt, wire or synthetic material in papermaking apparatus, comprises a roller 14 which, in use, engages the web 2 and which is supported by a pair of arms 12 pivotally mounted in a frame 10 by a cross-connecting shaft 13; a further pair of arms 20 connect the respective ends of the shaft 16 of the roller 14 to thrustproducing means 22, e.g. a fluid-pressure cylinder or a spring, arranged so that the roller 14 can be moved to tension the web 2. The arms 12 are positioned as shown to form an angle A with the vertical 24 so that the weight of the roller 14 is also utilized to tension the web 2. Thus the roller 14 can move on its pivoted arms 12 to compensate for minor variations in the tension of the web 2; to accommodate large variations in tension, the frame 10 is movable bodily along a surface 11, this movement being effected automatically when the pivotal arms 12 reach a limiting angular position determined by limit switches or signalled by an indicator 32 cooperating with contact points 33.</p> |
