Patent ID: 7952835

Claim:
A head stack assembly (HSA) comprising: a swing arm having an axis of rotation about which the swing arm is to rotate in a hard disk drive (HDD); a connection plate integral with the swing arm at a terminal end of the swing arm; a suspension attached to the connection plate; a head slider mounted to a terminal end of the suspension and having a read/write head for reading/writing data from/onto a data storage disk, and wherein the suspension includes a load beam and a flexure extending from the bottom of the load beam and supporting the head slider, the load beam comprises a main arm, first and second side rails extending along opposite sides of the main arm, and first and second connecting parts extending from a rear end of the main arm towards the connection plate, the first and second connecting parts being located on opposites sides of a central longitudinal axis of the HSA, the central longitudinal axis lying in a plane coincident with the axis of rotation of the swing arm and bisecting the head slider, the first and second connecting parts having attaching surfaces at which the connecting parts are attached to the connection plate, respectively, the attaching surface of the first connecting part lying in a plane beneath that in which the attaching surface of the second connecting part lies, the first side-rail extends alongside the main arm at that portion of the suspension which is disposed on said one side of the central longitudinal axis, the second side-rail extends alongside the main arm at that portion of the suspension which is disposed on said other side of the central longitudinal axis, and the first and second side-rails are each inclined relative to the main arm of the load beam and subtend different angles with the main arm, and that portion of the suspension which is disposed on one side of the central longitudinal axis and includes the second connecting part is stiffer, on account of said side rails, than that portion of the suspension which is disposed on the other side of the central longitudinal axis and includes the first connecting part.