| 摘要 |
864,371. Collapsible tyre-building formers. DUNLOP RUBBER CO. Ltd. Aug. 2, 1957 [Aug. 23, 1956], No. 25732/56. Class 144 (1). A collapsible former 1, suitable for building tyres of the form described in Specification 786,162, comprises a plurality of segments 7 which together form a part-spherical or cylindrical building surface 11, each segment 7 being pivoted at 9 on the ends of a common axis to two axially spaced supports 3, 4, which are secured to a rotary shaft 2, and each segment having a follower 12 attached thereto for cooperation with a cam surface 16 in a cam-plate 14 rotatably mounted coaxially on the shaft 2, rotation of the cam-plate 14 on the shaft effecting, through the followers 12, swinging movement of the segments about their pivots 9 to and from erected and collapsed positions (Figs. 1 and 3, respectively). As shown, fifteen segments 7 comprise the former surface, each being circumferentially split and bolted together about spacers 31 for axial width adjustment. Each segment has end pivots 9 received in bearings 10 in two support-plates 3, 4 drivably secured to the shaft 2, the plate 3 being axially adjustable on the shaft by spacers 6, 6a between the plate 3 and a fixed shaft collar 5. Two cam-plates 13, 14 are mounted one at each end of the shaft 2 on a common sleeve 15 which is rotatable on the shaft, the cam-plates being disposed axially between the adjacent supportplates and the segment ends, and each plate having fifteen cam-slots 16 therein to co-operate with follower pins 12 projecting axially from each end of each segment 7. Rotation of the cams is effected by means of a bell-crank lever 21 fulcrumed on a pivot 22 on the supporting- plate 4, Fig. 2, one arm 19 of the lever having a pin 18 drivingly engaged, through a slot 20 in the plate 4, in a slot 14a in the cam-plate 14, and the other arm 21a of the lever being drivably attached to a nut 25 displaceable along a rotatable screw-threaded rod 26 journalled on the plate 4. In an alternative arrangement the cam-plate 14 may be connected to a gear-wheel which is driven by a manually-rotatable pinion. |
