PCT No. PCT/SE89/00037 Sec. 371 Date Sep. 27, 1989 Sec. 102(e) Date Sep. 27, 1989 PCT Filed Feb. 2, 1989 PCT Pub. No. WO89/07020 PCT Pub. Date Aug. 10, 1989.The present invention provides method and apparatus for joining together two or more overlaying sheet formed metals, either metallic or non-metallic, in which a movable punch is moved towards a stationary die axially in a first direction and into a first position that is independent of the thickness or the number of sheet formed members to be joined together. Thereafter, an anvil is co-axially moved towards the die and into a second relative position that is also independent of the thickness or the number of sheet formed members to be joined together. The anvil is blocked in its second relative position by a blocking element, and a movable die is co-axially moved towards the anvil and into a third relative position that is dependent upon forces applied to the die and on the number, thickness and material of the sheet formed members to be joined together. As an alternative, the punch may be the stationary element, while the die is the movable element. In either case, the first predetermined relative position between the punch and the die at the end of the first stroke is independent of both the thickness and number of sheet formed members to be joined together.
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