| 摘要 |
1,271,377. Punching. KAZUYOSHI KONDO. 11 April, 1969 [11 April, 1968; 10 July, 1968], no. 15517/69. Heading B3W. In a metal shearing process, a die 2 is moved towards a die 1 to shear off the major portion of the thickness of a workpiece 5 against a die 1, a punch 3 associated with the die 2 or, as shown in broken line, the die 1 being used to separate the partly sheared blank 4 from the workpiece. For perforating a workpiece. Fig. 2, a punch 8 is used in combination with a punch 7 for the major shearing action and a knockout 9 acts against a counter pressure member 10 to sever the waste 12 from the workpiece. The surface 13 of the die 1 and the punch 7 is preferably between 30 and 40% of the thickness of the workpiece to be sheared. The surface 13 may be inclined downwardly from the horizontal at up to 20 degrees towards the inclined face 15- to help to shed scrap. To promote waste removal in perforating the workpiece may be prepunched at 12<SP>1</SP> and/or a member (16), Fig. 5 (not shown), projects from the punch 8 to dish the waste 12, the punch being resiliently mounted to cause the member 16 to project progressively more during perforating. |
