| 摘要 |
In welding apparatus for web material, one of a pair of feed rollers for the web is reciprocatable by a crank shaft. A swing arm oscillated by the crank shaft oscillates a gear segment for intermittently driving the feed rollers. A clutch and brake unit for uncoupling and braking the feed rollers and vice versa is operated by a cam rotating with the crank shaft. The crank shaft is operatively connected to a disc which is provided with an eccentric slide block and turns at the same speed as the crank shaft. The slide block is longitudinally displaceable in a slot of the swing arm. The driving motion for the feed rollers occurs during rotation of the slide block by way of the sector remote from the pivot shaft of the swing arm. |
