Disk drive seal attached to a motor ring flange

A seal is coupled to a movable member in a disk drive for sealing an opening in a chassis over which the movable member passes. The seal comprises a first layer of foam attached to the movable member, and a second layer of low-friction plastic attached to the layer of foam. The foam layer presses the plastic layer against the chassis to seal the opening as the plastic layer slides over a surface of the chassis.

BACKGROUND 
1. Field of the Invention 
The present invention relates to disk drives of the type that accept 
removable disk cartridges, and more particularly, to a disk drive having a 
seal that blocks airflow between the inside and outside of a disk drive. 
2. Related Applications 
This application is based on prior provisional application Ser. No. 
60/003,758, filed Sep. 14, 1995, from which priority of this application 
is claimed. This application is related to U.S. Pat. No. 5,583,710, issued 
Dec. 10, 1997, in the names of Nicklos et al., entitled "Disk Drive Having 
An Automatic Spindle Motor Loading Mechanism," which is incorporated 
herein by reference, in its entirety. 
3. Description of the Prior Art 
Removable disk cartridges for storing digital electronic information 
typically comprise an outer casing or shell that houses a rotatable 
recording medium, or disk, upon which electronic information can be 
stored. The cartridge shell often comprises upper and lower halves that 
are joined together to house the disk. The disk is mounted on a hub that 
rotates freely within the cartridge. When the cartridge is inserted into a 
disk drive, a motor-driven spindle in the drive must engage the hub in 
order to rotate the disk(s) within the cartridge. 
U.S. Pat. No. 5,204,793, Apr. 20, 1993, Garold Plonczak, "Removable 
Cartridge Disk Drive With an Integral Head Loading Ramp, Air Filter and 
Removable Cartridge Door Safety Stop" relates to a removable cartridge 
disk drive with an integral head loading ramp, air filter and removable 
cartridge door safety stop. Air filters for reducing contamination in disk 
drives are known. 
The disk drive shown and described in the related application has an 
opening in the drive which cannot be blocked with air filters of this 
type. It is an object of the present invention to block airflow into a 
disk drive. By blocking airflow, the particles that occupy a volume of air 
are not permitted to enter the internal part of the disk drive. These 
particles would otherwise damage the head disk interface. 
SUMMARY OF THE INVENTION 
This invention reduces particles inside a disk drive. According to one 
aspect of the present invention, this is accomplished by sealing an 
opening that provides an access to a rotating flange on the outside of the 
drive to link it to a rotating lever on the inside of the drive. The seal 
is attached to the rotating flange on the outside of the drive. It is 
comprised of a layer of low friction plastic attached to a foam layer that 
matches the perimeter of the rotating mechanism. The attachment layer is a 
pressure sensitive adhesive, and this same layer is used to attach the 
seal to the rotating flange. The layer of foam provides a compliant, 
compressible spring layer that, when attached to the plastic, provides a 
force that creates a seal between the rotating flange and the drive. 
According to another aspect of the present invention, a second seal is 
provided to cover an opening through which the pins of a connector extend 
into the interior of the disk drive. This second seal prevents particles 
from entering the disk drive through this additional opening. 
Other features and advantages of the present invention will become evident 
hereinafter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
FIG. 1 shows a preferred embodiment of a disk drive 20 for receiving a 
cartridge, according to the present invention. The disk drive 20 comprises 
an outer housing 18 that is attached to a rigid chassis 21. A front panel 
24 is attached to a forward end of the chassis 21. A disk cartridge (not 
shown) is inserted into the disk drive 20 through an elongate, horizontal 
opening 22 in the front panel 24. An eject button 26 is provided on the 
front panel 24 for automatically ejecting the disk cartridge from the disk 
drive 20. In the embodiment shown, the disk drive 20 is configured for 
insertion into the housing of a computer system, such as a personal 
computer. However, the disk drive 20 can also be employed as a stand-alone 
unit. Preferably, the front panel 24 is formed of plastic, and the housing 
18 and drive chassis 21 are formed of metal, although other suitable 
materials may be employed. 
FIG. 2 is a perspective view of the disk drive 20 of FIG. 1 with the 
housing 18 removed. As shown, a number of components are mounted on the 
upper surface 21a of the drive chassis 21. For example, an actuator arm 
32, which forms part of a radial arm voice coil actuator, is pivotally 
mounted to the drive chassis 21 at 38. The actuator arm 32 has a plurality 
of suspension arms 34 at its distal end that each carry a read/write head 
36 for recording and reading information to and from respective surfaces 
of the recording disks of a disk cartridge (not shown). A voice coil 
element 42 is affixed to the other end of the actuator arm 32 for 
controlling the rotational movement of the arm 32. A head loading 
mechanism 35 facilitates loading of the magnetic heads onto the disk 
surfaces. Additional details of the actuator and head loading mechanism 
are provided in co-pending, commonly assigned, U.S. patent application 
Ser. No. 08/438,254, entitled "Head Loading Mechanism for a Disk 25 Drive" 
and in co-pending, commonly assigned, U.S. patent application Ser. No. 
08/377,033, filed Jan. 23, 1995, entitled "Compliant Anchor for Securing 
Disk Drive Actuator Bearing", both of which are incorporated herein by 
reference, in their entireties. 
Another opening 130 is provided in the disk drive chassis 21, though which 
the pins of an electrical connector (not shown) extend to provide 
electrical connection between components on the upper surface 21a of the 
chassis and circuitry (not shown) on a bottom surface of the chassis. 
Further details concerning this aspect of the disk drive are provided 
hereinafter with reference to FIGS. 12-14. 
As further shown in FIG. 2, a head park lever 44 and a cartridge eject 
lever 50 are each pivotally mounted to the drive chassis. The operation of 
these levers 44, 50 is described hereinafter. As also described 
hereinafter, a spindle motor 110 and its housing 112 are mounted in a 
motor ring (not shown) on the underside of the drive chassis 21. The motor 
ring operates to translate the spindle motor vertically through an opening 
23 in the drive chassis 21 in order to engage the hub (not shown) of a 
disk cartridge (not shown) that has been inserted into the disk drive. 
FIGS. 3 and 4 show top and bottom views, respectively, of the disk drive of 
FIG. 2 and illustrate, in particular, a spindle motor loading mechanism. 
The spindle motor loading mechanism comprises, generally, a spindle motor 
110 and corresponding housing 112, a motor ring 66, a motor ring position 
transducer (not shown), a motor ring spring 71, a load/eject motor 74 and 
associated gear train 76-82, and the head park and cartridge eject levers 
44, 50 mentioned above. The spindle motor loading and unloading mechanism 
functions to (1) move the spindle motor into engagement with the hub of a 
disk cartridge upon insertion of the disk cartridge into the disk drive, 
(2) unlock the actuator arm of the radial arm voice coil actuator once the 
spindle motor is engaged, (3) disengage the spindle motor from the 
cartridge and eject the cartridge from the disk drive when the eject 
button on the front panel 24 of the disk drive is depressed and (4) move 
the actuator arm into a retracted, parked position as the cartridge is 
ejected from the disk drive. 
FIGS. 3 and 4 illustrate the position of the head park lever 44, cartridge 
eject lever 50 and radial arm voice coil actuator 30 when the drive is not 
in use, i.e., no cartridge has been inserted in the drive. As shown, the 
cartridge eject lever 50 is pivotally mounted to the upper surface 21a of 
the drive chassis 21. A spring 60 biases the eject lever 50 toward the 
insertion end 27 (i.e., front) of the drive chassis 21. A catch 52 formed 
at the distal end of the eject lever 50 engages a pin 62 that is attached 
to a portion of the motor ring 66 on the underside 21b of the drive 
chassis. When the motor ring 66 is in the position shown in FIG. 3, the 
pin 62 prevents the eject lever 50 from springing further toward the 
insertion end 27 of the drive chassis 21. 
The eject lever 50 has a dwell cam surface 54 and a second cam surface 56 
that, as described hereinafter, slide over the pin 62 of the motor ring 66 
during various stages of rotation of the motor ring 66. In the position 
shown in FIG. 3, the dwell cam surface 54 contacts the pin 62 and thereby 
prevents the motor ring 66 from rotating toward the pivoted end 61 of the 
eject lever 50, i.e., clockwise in FIG. 3(counter-clockwise when viewed in 
FIG. 4). 
A cartridge push tab 58 on the eject lever 50 engages the forward end face 
of a disk cartridge when the cartridge is inserted into the disk drive 
through the insertion opening 22 in the front panel 24 of the drive. 
Continued insertion of the disk cartridge causes the eject lever 50 to 
pivot toward the rear end 29 of the disk drive against the force of spring 
60. This loads the spring 60. As the eject lever 50 pivots toward the rear 
end 29 of the disk drive, the dwell cam surface 54 will slide along the 
pin 62 until it moves just past the pin 62, thereby releasing the pin 62 
and allowing the motor ring 66 to rotate. 
The head park lever 44 is pivotally mounted to the upper surface 21a of the 
drive chassis 21 at 44a. Movement of the head park lever 44 is controlled 
by movement of the motor ring pin 62 along a contoured groove 48 in the 
head park lever 44. As the motor ring 66, and hence pin 62, rotate 
clockwise in FIG. 3 (counter-clockwise when viewed from below in FIG. 4), 
the pin 62 will engage the contoured surfaces of groove 48 causing the 
head park lever to swing toward the insertion end 27 of the disk drive. 
Movement of the motor ring 66 in the opposite direction will cause the 
head park lever 44 to move back to the position illustrated in FIG. 3. 
The head park lever 44 has a push back tab 46 positioned to engage a mating 
projection 40 formed on the actuator arm 32. In the position shown in FIG. 
3, the push back tab 46 of the head park lever 44 prevents the actuator 
arm 32 from rotating toward the insertion end 27 of the disk drive, i.e., 
the actuator arm 32 is in a "parked" position. Movement of the head park 
lever 44 toward the insertion end 27 of the disk drive will, of course, 
move the push back tab 46 away from the actuator arm 32, allowing the 
actuator arm 32 to move toward the insertion end 27 of the drive in order 
to load the read/write heads 36 at the end of the actuator arm 32 onto the 
recording disks of the cartridge (not shown). 
FIG. 4 shows the underside 21b of the drive chassis 21 and provides 
additional details of the spindle motor loading mechanism, including the 
motor ring 66, load/eject motor 74 and gear train 76-82. The motor ring 66 
is rotatably mounted on the underside 21b of the drive chassis 21 via 
three flat-headed pins 69a-c that capture a retaining shoulder 66a that 
extends around the base of the motor ring 66. Access pockets 101a-c are 
formed in the retaining shoulder 66a to facilitate assembly of the motor 
ring 66 to the drive chassis 21. The motor ring 66 is mounted by aligning 
the access pockets 101a-c with the flat-headed pins 69a-c, pressing the 
motor ring 66 against the underside 21b of the drive chassis 21, and then 
rotating the motor ring 66 into position so that the flat-headed pins 
69a-c capture respective portions of the retaining shoulder 66a. 
The motor ring 66 has an enlarged seal flange 64 that rides in a recessed 
portion 73 of the drive chassis 21 as the motor ring 66 rotates back and 
forth. In the present embodiment, the motor ring 66 rotates back and forth 
through a 20.6 degree arc. The aforementioned pin 62 of the motor ring 66 
is affixed (e.g., riveted) to the enlarged flange 64, and, as mentioned 
above, extends through an elongate opening 62a in the drive chassis to 
engage the groove 48 of the head park lever 44 and the dwell cam and 
second cam surfaces 54, 56 of the eject lever 50 on the opposite side of 
the chassis 21. The elongate opening 62a in the chassis must be 
sufficiently long and wide to allow the pin 62 to move through the entire 
20.6 degree arc of the motor ring 66. The seal flange 64 blocks off the 
opening 62a in the drive chassis 21 over the full travel of the motor ring 
66 to reduce contamination flow in the drive. 
FIG. 5 is a perspective view of the spindle motor 110 and its associated 
housing 112. The housing 112 of the spindle motor has a plurality of pins 
extending substantially radially therefrom. In the present embodiment, the 
housing 112 has three pins spaced equally about the circumference of the 
housing 112. 
FIGS. 6A-6D show further views of the motor ring 66 and provide additional 
details thereof. As shown, the motor ring 66 further includes a plurality 
of cam slots 106a-c that receive the corresponding pins 104 of the spindle 
motor housing 112 when the spindle motor is mounted in the motor ring 66. 
As described herein, the motor ring 66 and associated pin 62 define a first 
movable member on the outside of the chassis 21 of the disk drive, and the 
head park lever 44 defines a second movable member on the inside of the 
chassis 21. The pin 62 of the motor ring 66 is coupled to the head park 
lever 44 through the opening 62a in the chassis. 
In accordance with the present invention, a seal 115 is mounted on the seal 
flange 64 of the motor ring 66. The seal 115 blocks contaminating airflow 
through opening 62a in the chassis. As best shown in FIG. 11, the seal 
includes a layer of low friction plastic 116 attached to a foam layer 117 
by adhesive 118. A pressure sensitive adhesive is used and is also used to 
attach the seal 115 to the flange 64. The layer of foam 117 provides a 
compliant, compressible spring layer. In combination with the plastic 
layer 116, it provides a force that creates a seal between the rotating 
flange and the chassis 21 of the drive over the full range of motion of 
the rotating flange 64. 
The friction between the seal and the drive is low for several reasons. The 
low friction plastic interfaces with the chassis 21 of the drive rather 
than having the foam itself interface with the drive. The foam occupies a 
small portion of the total surface area of the seal and thus provides low 
pressure against the drive. The surface of the plastic is lower in 
elevation where it is joined to the rotating flange, in comparison to the 
outside edge. As a result, the foam forces the plastic into a concave 
surface. The result is that the pressure exerted by the foam is highest at 
the outside edge of the seal. This provides a high force over a very small 
area with the result being an excellent seal with a relatively low 
pressure between the rotating mechanism and the drive. The features of 
this aspect of the invention include a movable seal that has low friction 
between surfaces, has a thin profile, conforms to a surface which is not 
flat, exerts minimal pressure, is low-cost and is lightweight. 
FIG. 12 is a top view of a portion of the upper surface 21a of the chassis 
21 of the disk drive, showing, in particular, the additional opening 130 
in the chassis. The opening 130 provides a means through which the pins of 
an electrical connector (not shown) extend to provide electrical 
connection between components on the upper surface 21a of the chassis and 
circuitry (not shown) on a bottom surface of the chassis. The opening 130 
is located in a recessed portion 132 of the upper surface 21a of the 
chassis 21. The recessed portion 132 of the chassis receives a small 
circuit board when the drive is fully assembled, as described hereinafter. 
FIG. 13 is a sectional view of the portion of the disk drive shown in FIG. 
12, taken along line 12--12. FIG. 13 shows various components that were 
omitted from FIG. 12 for convenience. As shown in FIG. 13, a small circuit 
136 occupies the recessed portion 132 of the upper surface 21a of the 
chassis of the disk drive. Pins (e.g., 134), which form an electrical 
connector, extend downward from the circuit board 136, through the opening 
130 in the chassis. According to another aspect of the present invention, 
the pins of the connector extend past the bottom surface 21b of the 
chassis, through a second seal 140, and then through a second circuit 
board 142 mounted to the bottom surface 21b of the chassis. A thin layer 
of plastic 138, which has an opening that is coextensive with the opening 
130 in the chassis, lies between the bottom surface 21b of the chassis and 
the second circuit board 142 to prevent undesired contact between the 
chassis 21 and the second circuit board 142. 
In the present embodiment, the second seal 140 is made of a thin layer of 
foam. However, in other embodiments, other suitable materials may be 
employed, such as, for example, rubber. As best shown in FIG. 14, the 
second seal 140 lies over the opening 130 on the bottom surface 21b of the 
chassis to prevent particles from passing through the opening 130 to the 
other side 21a of the chassis (which defines the interior of the drive 
when the drive is fully assembled). The pins (e.g., 134) of the connector 
pass through the foam layer 140, which conforms to the pins to maintain 
the seal. 
It is understood that changes may be made to the embodiments described 
above without departing from the broad inventive concepts thereof. 
Accordingly, the present invention is not limited to the particular 
embodiments disclosed, but is intended to cover all modifications that are 
within the spirit and scope of the invention as defined by the appended 
claims.