Importance

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Abstract

A method and apparatus for positioning tooling and riveting the apparatus including a frame provided with opposed riveting rams (96, 86) and clamps (34, 36). The first clamp (34) is extended above the work plane established by the outer surface of one workpiece (10) with the lower ram retracted. Next, the frame (26) is moved downwardly until the first clamp touches the workpiece. An encoder (140) measured the amount of first clamp collapse during overtravel of the frame after the first touch is sensed. The frame is now backed off this distance to establish a work line coextensive with the work plane. The lower clamp (36) is then raised to clamp the workpieces (10, 12) and drill carried by a sub-frame (66) will now drill aligned apertures through the workpieces. The subframe is indexed to another position to place rams (96, 86) is alignment with the apertures. The upper riveting ram (96) is then advanced to its full down position to set an upper cavity and is locked under high pressure. The lower ram (86) then rises under low pressure to a snug up position. Squeeze forming is now accomplished by simultaneously controlled motion of the frame down and the lower ram up until an upset complete signal is received. During this operation the upper clamp (34) is in a resilient condition. When the rivet is completely upset pressure is dumped from the upper clamp and simultaneously the frame is driven to its start position and the lower ram is retracted. As soon as the lower ram reaches its back away position the upper riveting ram is fully retracted.

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First Claim