| 摘要 |
The movable blank-holder of a bending press includes a series of segments and a pair of motor-driven carriages each of which has an entraining member which can selectively engage and release the segments in order to move them for re-arrangement purposes. Each of two segments situated at opposite ends of the series includes a shoe-holder which supports a respective shoe by means of inclined guides. Each shoe-holder body carries a respective slide having a driving portion and each shoe has a driven portion. These driving and driven portions have facing cooperating pressure and sliding faces arranged in a manner such that a movement of the slide towards the center of the press is converted into an oblique movement of the respective shoe such that it is released from a lateral channel-shaped bend already formed in a metal sheet, without sliding on the sheet. Each carriage includes an entraining member and each slide includes an entrained member which can be engaged by the entraining member in order to move the slide selectively towards the center of the press. The two carriages are movable simultaneously in opposite directions upon command in order to simultaneously bring about the aforementioned movements of the shoes, by means of the slides, in directions such as to release them from the respective lateral bends. The shoes have respective resilient mechanisms for biasing them in directions to return each shoe to a working position to which it is moved away from the center of the press and from the movable blank-holder.
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