| 摘要 |
A process of forming bend-controlling structures, such as slits, grooves or displacements ( 22 ), in a sheet of material ( 21, 121, 221, 321, 421, 521, 621, 721 ). The bend-controlling structures ( 22 ) have central portions ( 26 ) extending substantially parallel to a desired bend line ( 23 ) on the sheet and end portions ( 27 ) which diverge away from the bend line ( 23 ). In one embodiment the process includes the step of forming the bending straps ( 24 ) between pairs of slit end portions ( 27 ) at a desired spaced apart distances along the bend line ( 23 ) with the straps ( 24 ) having a desired configuration, and the step of forming central portions ( 26 ) which connect the end portions ( 27 ) to complete the slits ( 22 ) using a separate die set. A plurality of end portion dies ( 51/54 ) can be used to produce end portions ( 27 ) of various shapes and straps ( 24 ) of various widths, and a single set of central portion forming dies ( 71/74 ) are used to connect the end portions ( 27 ). In other embodiments die sets producing a single end portion ( 27 ) or mirror image impressions (A, B) are used and preferably overlapped to produce the complete bend-controlling structure ( 22 ). A modular die assembly ( 500 ) also is disclosed in which the bend-controlling structures can be produced by modular die inserts ( 511 - 514, 611 - 614 ). Finally, a selection of die sets ( 722 a, 722 b, 722 c) of differing length from a group of die sets can be made to position the bending straps ( 24 ) at desired locations along the bend line. |
