Gm Global Technolgoy Operations, Inc.

Michael A Dykema

Terry E Burkhard

A variable length shaft assembly suitable for motor vehicle steering systems including a tubular outer shaft of non-circular cross section and a solid inner shaft of corresponding non-circular cross section telescoped inside of the outer shaft. A U-shaped metal spring is disposed over the solid shaft adjacent an outboard end of the tubular shaft with opposite legs of the spring in sliding engagement on corresponding flat sides of the solid shaft. A monolithic plastic sleeve is in situ molded on the tubular shaft and includes an integral lip closely surrounding the solid shaft. The integral lip captures the relative angular positions of the shafts about a longitudinal centerline of the assembly, i.e. delashes the shafts, defines a slide bearing between the shafts, and rigidly encases the spring. The surfaces of the legs of the spring which bear against the solid shaft are exposed after the sleeve is in situ molded and define wear plates on the integral plastic lip which protect the lip against abrasion.

Variable length shaft assembly

A variable length shaft assembly including a first shaft having a tubular polygonal end, a second shaft having a correspondingly polygonal solid end telescopically disposed in the polygonal tubular end, an arched spring in a spring chamber in the solid polygonal end having a planar body portion bearing in sliding engagement on a planar wall of the polygonal tubular end and biasing the polygonal solid and tubular ends in opposite directions to a substantially zero clearance relationship in which linear clearances are reduced to substantially zero, and a monolithic plastic block injection molded in situ in the spring chamber behind the flat body portion. After the in situ injection molded plastic solidifies, the monolith plastic block captures the substantially zero clearance relationship between the polygonal solid and tubular ends and encases the arched spring such that the flat body portion thereof defines a reinforced wear plate on the block in sliding engagement on the planar wall of the tubular polygonal end.

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Birch Run, MI, United States of America

Michael A Dykema