Camshaft for reciprocating piston engines

A camshaft for reciprocal piston engines comprising:

• a rotatable and expandable tube having an axis and an annular wall;
• and axially spaced members [including axially spaced cams and bearing rings] mounted about the tube, the rotatable tube and the axially spaced members [, cams, and bearings] having the same axis;
• the rotatable tube having a plurality of circumferentially spaced projections spaced around its entire circumference and extending axially through and from one longitudinally outermost member to and through the other longitudinally outermost member, said circumferentially spaced projections being spaced apart from each other, the projections being formed by expanding circumferentially spaced portions of the wall of the tube away from the axis of the tube, each [cam and each bearing ring] axially spaced member having a plurality of circumferentially spaced axially extending grooves on [their] its inner [surfaces] ;
• surface , said circumferentially spaced grooves being spaced apart from each other, each projection of the tube extending only partially into a groove of each axially spaced member, [cam and a groove of each bearing ring to permanently secure the cams and bearing rings on the tube] the annular wall of the tube characterized by expansion into contact with the inner surface of the axially spaced member, each projection of the tube characterized by expansion greater than the expansion of the annular wall of the tube between projections.