| 摘要 |
The apparatus comprises a punch 2 arranged for reciprocating movement along an axis 31, the punch having two flat opposite sides 20, 21 parallel to the axis, and a die 3 mounted in axial alignment with the punch. The die 3 comprises a die body 5 also having two flat opposite sides 22, 23 parallel to the axis 31 and a pair of flat parallel spring stool leaf springs 7 each lying along a respective one of the parallel sides of the die body. The leaf springs are secured against the die body 5 at a point 8 below the free end 6 of the die body which faces the punch and extend along the parallel sides 22, 23 of the die body to terminate above the free end 6. The leaf springs 7 initially resist the deforming action of the punch but spring apart as pressure builds up. This delayed action gives the joint right angular edges which retain filler material more readily. The apparatus is a modification of that in UK Patent No. 2087284. <IMAGE> |
