Patent ID: 7992532

Claim:
A switchable hydraulic lash adjuster comprising: (a) an outer cylindrical housing having a first internal, axial, cylindrical blind bore; (b) an inner cylindrical housing slidably mounted at an open end of the first bore, the inner housing having a second internal, axial, cylindrical blind bore; (c) a lash adjuster piston slidably mounted at an open end of the second bore; (d) a lost motion spring mounted in the first bore between a bottom of the inner housing and a closed end of the first bore; (e) a radial hole extending through a side wall of the outer housing; (f) an inner indent in a side wall of the inner housing; (g) a ball housed in the radial hole and radially movable between a locked position where the ball engages the indent and the radial hole so that the inner housing is locked to the outer housing and an unlocked position where the ball is in the radial hole and disengages from the indent so that the inner housing is unlocked from the outer housing; (h) a piston axially, movably mounted outside the outer housing, the piston having a radial bearing surface and a radially outer indent, the piston axially movable on the outside of the outer housing between a first position where the bearing surface pushes the ball into engagement with the inner indent and the ball is in the locked position and a second position where the outer indent engages the ball and the ball disengages from the inner indent and the ball is in the unlocked position; and (i) a ball return spring housed on a side wall of the first bore as the radial hole and urging the ball into the unlocked position.