Rotatable actuator arm having an integral strut

#This invention relates to actuator arms for data storage disc drives, and particularly to rigid actuator arms formed of pliable material, such as sheet metal, with integral struts arranged to support an actuator coil.

#Rotating disc data storage devices store data along concentric tracks of a rotatable disc. An actuator assembly positions a transducer adjacent a selected track to transfer data between the disc media and the transducer. Electrical conductors couple the transducer to external circuitry, such as a data processor, so that data may be transferred to the transducer to write data to the medium and so that data read from the from the medium by the transducer may be transferred from the transducer. The actuator assembly consists of a rigid actuator arm that is pivotably mounted to the frame of the disc drive, a flexible suspension at the distal end of the actuator arm, a transducer mounted to the flexible suspension to “fly” a predetermined distance from the rotating storage medium, and a motor that rotates the actuator arm about the pivot point to move the transducer across the tracks on the medium. The suspension is resilient to provide a force, or load, to counter the upward force imposed on the transducer by the air movement supporting the transducer as it flies adjacent the rotating medium.

#It is important that the actuator assembly have minimum weight to minimize inertia that may adversely affect the response of the motor and arm to actuation signals to move the transducer across tracks of the medium. The arm of the actuator assembly must be sufficiently rigid so that impulse and acceleration forces on the arm during a track seek operation does not bend or distort the arm.

#FIG. 1 is a perspective view of a disc drive in which aspects of the present invention may be practiced.

#FIG. 2 is a top perspective view of an actuator arm in accordance with a first embodiment of the present invention.

#FIG. 3 is a bottom perspective view of the actuator arm illustrated in FIG. 2.

#FIG. 1 is a perspective view of a disc drive 100 in which the present invention is useful. Disc drive 100 includes a housing with a base 102 and a top cover (not shown). Disc drive 100 further includes a disc pack 106, which is mounted on a spindle motor (not shown) by a disc clamp 108 for rotation in the direction of arrow 132. Disc pack 106 includes a plurality of individual discs 107, which are mounted for co-rotation about central axis 109. Each disc surface has an associated slider 110 that is mounted in disc drive 100 for communication with the confronting disc surface. Slider 110 is arranged to fly above the associated disc surface of an individual disc of disc pack 106, and carries a transducing head 111 arranged to write data to, and read data from, concentric tracks on the confronting disc surface. In the example shown in FIG. 1, sliders 110 are supported by suspensions 112 which are in turn attached to track accessing arms 114 of an actuator assembly 116. Actuator assembly 116 is driven by a voice coil motor (VCM) 118 to rotate the actuator assembly, and its attached sliders 110, about a pivot shaft 120. Rotation of actuator assembly 116 moves the heads along an arcuate path 122 to position the heads over a desired data track between a disc inner diameter 124 and a disc outer diameter 126.

#Voice coil motor 118 is operated by position signals from servo electronics included on circuit board 128, which in turn are based on error signals generated by heads 111 and position signals from a host computer (not shown). Read and write electronics are also included on circuit board 128 to supply signals to the host computer based on data read from disc pack 106 by the read portions of heads 111, and to supply write signals to the write portions of heads 111 to write data to the discs.

#FIGS. 2-7 illustrate an actuator arm 114 in accordance with a first embodiment of the present invention. Actuator arm 114 is formed by folding a single planar sheet 200 of pliable material, such as 0.005 to 0.010 inch thick No. 300 series steel. Sheet 200 includes a bore hole 202 that supports a portion of a pivot bearing mounted to base 102 (FIG. 1) so that actuator arm 114 may be rotated about axis 120. Longitudinal struts 204 and 206 are formed by bending the material of sheet 200 normal to the planar surface 220 of the sheet so that struts 204 and 206 extend along longitudinal edges 208 and 210 of arm 114, terminating at distal end 212. A flex cable bracket 214 and flex cable retention arm 216 are formed along one edge 210 of arm 114, again by bending the material of sheet 200 to form the bracket and arm. Usually, apertures, such as aperture 218, are formed through of sheet 200 for balance and weight purposes. Mounting hole 222 is formed though sheet 200 adjacent distal end 212 so that suspension 112 (FIG. 1) may be attached to arm 114, such as by a suitable adhesive, swage connection, rivet, etc.