| 摘要 |
672,413. Work holders. WALES-STRIPPIT CORPORATION. April 11, 1950 [Aug. 24, 1949], No. 8909/50. Class 60. [Also in Group XXII] A pneumatic device for rotatably holding workpieces in nibbling, punching &c. machines comprises a head adapted to engage a workpiece to seal off a predetermined area which communicates with a cylinder and plunger by which the sealed-off chamber is exhausted, the chamber having a volume small with relation to the cylinder and an area large with relation to the plunger. The head 16 is rotatably mounted in a bracket 31 adjustable on an arm 10 clamped by a screw 19 to a post 18 adjustable in a slot 13a in the die holder 13: A punch or rubber 15 co-operates with a die in the holder. The head comprises a disk 37, with insert sealing ring 38, secured to a cylinder 35 by plug 41 with air hole 43 and screwed centre 53. The plunger 44 carries a rubber ring 50 in a recess 49 with air passage 51. On the downstroke of the plunger the ring 50 rises in the recess 49 and allows air to be exhausted through the passage 51. When a spring 45 raises the plunger the ring 50 seals the passage 51 and air is exhausted from between the workpiece and the disc 37 through the hole 43, to grip the workpiece, the necessary pressure being obtained by making the volume of the space over the workpiece small with relation to the cylinder and the area large with relation to the plunger. The cylinder is held to the bracket by a screwed bush to allow the workpiece to be rotated for nibbling about a fixed centre. The holder may be adjusted in height by the screw connection between the bush and the bracket. U.S,A. Specification 2,364,011 is referred to. |
