| 摘要 |
<p>1,006,670. Feeding webs. H. C. LARRIEU. May 4, 1962 [May 6, 1961], No. 17124/62. Heading B6B. Mechanism for feeding strip material 32, Fig. 1, step-by-step through e.g. a metal-cap forming machine, includes a device for clamping the strip in registered position, which device is operated pneumatically when perforations in the strip register with suction ports associated with the device. The mechanism comprises a feed roller 5 having suction ports 17, Fig. 4, on its periphery whereby the strip is gripped and fed forward during a part of each cycle of the machine. The feed roller 5, driven in synchronism with the machine, is mounted between plates 7, 8, Fig. 3, fixed to plates 2, 3 secured to the frame 1 of the machine. Suction ports 17 on the periphery of the roller communicate by means of passages 19, 18 in the roller with a groove 20 in the plate 7. Suction is applied to the groove 20 through an orifice 16 so that during most of the period the passage 18 is in communication with the groove 20 and suction is being applied to the ports 17, the web 32 is fed forward by the roller 5. At the latter end of that period, however, the web is held by the clamping device as described below and the ports 17 slip over its surface. The clamping means comprises an adjustably-fixed block 21, Figs. 1, 2 over the surface of which the web passes, and having side guides 22. Between the guides 22, a freely slidable block 33 is mounted, and rests on the web. The block 33 has a cavity 36 on its lower face. Passages 31 in the lower block 21 communicate by means of a passage 29 with a passage 15 in the plate 7 communicating with a groove 14 in the roller 5 at certain angular positions of the roller. Another passage 13 in the plate 7 is connected to suction and also opens into the groove 14 at certain angular positions of the roller 5. After the web has been fed a certain distance, suction is applied to the passages 31 through passages 13, 14, 15, 29 and causes braking of the web without stopping its feed. When, however, perforations 43, Fig. 5 (not shown) in the web, situated between printed designs, register with the passages 31, suction is admitted to the cavity 36 in the block 33 drawing the block downwards so that the web is clamped between the blocks and feed prevented whilst the passage 13 communicates with the groove 14. The clamping lasts until beyond the period during which the ports 17 act on the web. Stationary guides.-The web is guided over the roller 5 by a member 37, Fig. 1, and is stripped therefrom by a member 39 engaging a groove 38 in the roller.</p> |
