Patent ID: 7775075

Claim:
A lock cylinder comprising: a housing defining a cylindrical cavity, and an outer pin chamber communicating with the cavity, the outer pin chamber being adapted to house an outer pin; a plug disposed in the cavity and rotatable within the cavity between a locked position and an unlocked position, the plug having an inner pin chamber that is aligned with the outer pin chamber when the plug is in the locked position; a key slot disposed at least partially through the plug, the key slot communicating with the inner pin chamber; an inner pin housed in the inner pin chamber for movement along an axis, the inner pin engageable with a key inserted into the key slot, the inner pin engageable with the outer pin when the plug is in the locked position and including an outer surface having a non-axial groove, the non-axial groove having a curved surface defining a substantially semi-circular cross-section; and an engagement member supported by the plug and having a substantially semispherical end portion extending into the non-axial groove such that the semispherical end portion is substantially engaged with the curved surface.