| 摘要 |
<p>1,181,128. Shearing and punching. SOC. DES FABRICATIONS BIRAGHI-ENTREPOSE. 4 July, 1967 [20 April, 1967], No. 30764/67. Heading B3W. A blank 10 of indefinite length is periodically advanced beneath a reciprocating head 11 carrying cutters 13 which produce transverse slits 4 in at least one of the blank edges, and a stepped cutter 15 which with each cutting stroke of the head 11 (direction F 1 ) cuts a further length of a central slot 18 in the blank, this slot eventually severing the blank into two strips 3 at least one (both, as shown) of which is edge-slotted and intended for use as a heat exchanger tube fin. The stepped cutter 15 has two portions of unequal length, the longer portion 15a having an abutment face 15c. When the head 11 is in the raised position shown, after the cutting stroke, the blank is advanced (direction F) until the leading edge of the centre slot 18 abuts the face 15c of the cutter 15. Thereafter the head 11 descends to cut further slots 4 and a further portion of the slot 18. The blank rests upon a matrix 12 having openings 16, 17 therein to facilitate ejection of scrap.</p> |
