GB474029A - Improvements in or relating to web guiding mechanism - Google Patents

Abstract

474,029. Feeding webs. HOE & CO., Ltd., R. (Hoe & Co., Inc., R.) April 20, 1936, No. 11289. [Class 100 (i)] A web-guiding roller for a printing or other machine is supported by mechanism allowing it to turn about a transverse axis to compensate for differences of tension at opposite edges of the web, the mechanism being adjustable to vary the position of the transverse axis longitudinally of the roller, in accordance with the width of web being used, so that the axis can coincide with the centre of the web. In one form, Fig. 5, the roller 10 turns freely on a shaft 12, which is rotatable in slidable bearing blocks 13, 14 and has secured thereto oppositely directed slotted arms 19, 18 in which are slidably mounted pivot blocks 23, 22 which are connected, one directly and the other through pivoted arm 24 and link 28, to arms 27, 29 fixed on a shaft 31. The roller 10 can thus turn about a transverse axis, the position of which along the roller depends upon the ratio of the distances of the pivot blocks 22, 23 from the axis of the shaft 12. This ratio can be varied in accordance with the width and position of the web by means of a hand-lever 34 fixed to the shaft 31 and provided with a locking pin 36 which is engaged in one of a series of holes 37 corresponding to full width webs, and half and three quarter width webs on either side of the centre line of the machine. In a modification, Fig. 19, the slotted arms 128, 129 fixed to the shaft 102 of the roller 101 engage fixed pivots 134 and the effective lengths of the arms are varied by lifting the shaft 102. For this purpose, the shaft is supported at its ends in blocks 106 secured to resiliently supported rods 108 held in various positions by arms 115 on a shaft 116 adjusted by a hand-lever 118 similar to the hand-lever 34 of Fig. 5. In another form, Fig. 14, the roller 75 is carried by a bar 79 which can turn about a transverse pivot 82, carried by a block 81, and the position of the pivot can be varied by adjustment of the block 81 by a screw 87. In another form, the bearing blocks of the roller shaft are each connected to one arm of a bell crank lever, the other arms of which are connected by a link, the point of attachment of which to one bell crank lever is adjustable so as to vary the effective length of that lever. In a further form, Fig. 23, the ends of the shaft 138 of the roller 137 rotate, without axial movement, in bearings 139 hung upon shafts 140 mounted in bearing boxes 141 slidably mounted in slotted arms 142 of bell crank levers, the other arms 144 of which are connected by a link 152. The roller can thus turn about a transverse axis 168 which is substantially tangential to the surface of the roller and with the parts arranged as shown this axis is midway of the length of the roller. The position of this axis may be varied by adjustment of the boxes 141 in the arms 142, this being effected by a screw 154 threaded in a block 158 fixed to one of the shafts 140. To compensate for the weight of the roller, adjustable springs 160 may be arranged between fixed brackets 161 and the bearing blocks 139.