| 摘要 |
A joint between the overlapped ends of two metal strips comprising strip portions defined by parallel straight longitudinal slits cut through the thickness of both strips, adjacent strip portions being deflected in opposite directions to define a transverse passage and a lock pin located in said passage is produced by apparatus comprising a pair of parallel cutter bars arranged on opposite sides of the path of the metal strip carried by supports, provided with means for moving said cutter bars towards and away from each other, each cutter bar carrying a plurality of laterally spaced cutter elements, the space between adjacent cutter elements on each cutter bar being substantially equal to the thickness of width of the cutter elements on the other cutter bar, the cutter elements on each cutter bar being arranged to mesh with the cutter elements on the other cutter bar, each cutter element having at least a part-circular periphery, each cutter bar being rotatable in relation to its support between a series of positions and being provided with means for holding it against rotation in a plurality of positions. Some at least of the cutter elements are provided with arcuate recesses in their periphery. When these recesses are indexed to face the opposed cutter bar, such cutter elements are rendered inoperative. |
