Handle mechanism and casing assembly including the same

A handle mechanism, adapted to be mounted on a slidable plate and configured to slide the slidable plate relative to a chassis, comprising:

• a handle, adapted to be pivotably disposed on the slidable plate so as to have an engaged position and a disengaged position;
• and
• an engagement component, slidably disposed on the handle and adapted to contact the chassis to slide the slidable plate into the chassis, wherein the engagement component has a contact surface, and the contact surface has an edge located away from an axis of the handle;
• wherein the axis of the handle is located outside an outer profile of the engagement component, a distance between the edge of the contact surface of the engagement component and the axis of the handle in the engaged position is smaller than a distance between the edge of the contact surface of the engagement component and the axis of the handle in the disengaged position.