Abstract:
An anti-motor fret package/container is provided including a main insert, a top cover, and a cardboard shell. The package is especially adapted for securing computer disk drives therein. Potential damage to the computer disk drives is minimized by isolating any movement of the disk drives within the package. A central rib, displacement means, or contacting means are provided to press or hold the disk drives tightly against side walls of their loading compartments. Movement of the disk drives within the package is particularly constrained in the lateral or transverse direction to avoid the phenomena known as motor fret. The overall arrangement and construction of the package minimizes vibration and shock transferred to the disk drives during shipment.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     Priority is claimed from U.S. Provisional Patent Application No. 60/232,811, filed on Sep. 15, 2000 and entitled “Anti-Motor Fret Package for Multiple Disk Drives” and further identified as the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to a container or package used for shipment and storage of computer disk drives, and more particularly, the present invention relates to an anti-motor fret package for multiple disk drives which protects the computer disk drives from vibration and shock which may occur during shipment and storage. 
     BACKGROUND OF THE INVENTION 
     Computer disk drives are common to personal computers, laptop computers, and other computing devices. As with any product, computer disk drives at some point in time must be shipped from a manufacturer or distributor to another location where the disk drives may be used. As understood by those skilled in the art, computer disk drives are precision electromechanical devices which electronically store data and allow data to be manipulated in accordance with the functioning of computing device in which the disk drives are installed. A computer disk drive includes one or more disks or platters which rotate at high RPMs and are driven by a spindle motor. Because of the advances in the manufacture of disk drives, many disk drives now have thicker platters or disks which weigh more and, thus, have more inertia during rotation. Each computer disk drive also includes at least one read/write component known as the “head” which reads and writes data to and from its corresponding platter. During shipment, a disk drive is shipped with its head in the “landing zone.” The “landing zone” is an area on a platter where the head is positioned when the disk drive is not in use. In previous disk drive construction, the contact of a head against its corresponding platter in landing zone created enough friction to prevent the platter from any rotational movement during the shipment. However, refinements in the construction of some computer disk drives have also resulted in fewer and/or smaller heads being used. Accordingly, for these newer types of disk drives, there is not enough friction between the smaller heads and the landing zone corresponding with each platter to prevent the platters from rotating due to vibration or shock during shipment. Vibrations experienced by these types of disk drives during shipment can cause the platters to partially rotate in repetitive back and forth motions. These small, partial rotations of the platters cause the lubrication to be displaced or separated from the ball bearings and bearing races within the spindle motors which drive the platters. As grease or lubricant separates from the ball bearings and bearing races, the bearings and races become damaged from lack of proper lubrication. This damage is called “motor fret.” When the disk drive is then installed in a computer, the motor fret is significant enough to result in increased motor noise, typically from three to eight decibels. This increase in noise is a defect which makes the disk drive unsuitable for sale to a consumer. 
     Most multi-pack boxes which are used for shipment of computer disk drives arrange the disk drives on edge and orient them transversely with respect to the long axis of the box. Unfortunately, pronounced vibrations can occur to a disk drive during shipment in such containers. Transverse or side-to-side vibration during shipment results in motor fret. 
     SUMMARY OF THE INVENTION 
     In accordance with this invention, an anti-motor fret package or container is provided which prevents motor fret. Although the present invention involves a combination of elements, there is also utility with respect to various subcombinations to include a top cover and stabilizing member used in the package. Also in accordance with the invention, methods are provided which facilitate shipment of computer disk drives in a way to avoid motor fret. 
     In its simplest form, the package or container of the invention includes three major components, namely, a main insert, a top cover, and a cardboard shell. The main insert is constructed of expanded polypropylene material molded to include a plurality of compartments to receive disk drives loaded therein. The compartments are arranged in one or more rows extending longitudinally along the length of the package. The top cover is placed over the main insert and contacts the upper surfaces of the disk drives. A stabilizing member in the form of a central rib communicates with the top cover, and extends longitudinally along the row(s) of disk drives to particularly constrain the disk drives from lateral or transverse movement within their respective compartments. In some embodiments, the central rib is attached to the lower surface of the top cover while other embodiments separate the central rib from the top cover. The main insert, top cover, and central rib are housed within the cardboard shell which is in the form of a corrugated cardboard box. 
     Typically, the main insert includes two parallel rows of compartments for holding a plurality of disk drives. A longitudinally extending gap separates the rows of disk drives. The central rib is positioned so that it extends along and fills this gap, and makes contact with the disk drives pushing or displacing them transversely against outer edges or walls of their respective compartments. The central rib particularly constrains the disk drives from lateral or transverse motion within their respective compartments, thus minimizing motor fret induced by undesirable transverse or lateral vibration. 
     Disk drives that are prepared for shipment are often placed in a flexible plastic bag or container for various reasons, including preventing a static charge from damaging the drives. Thus, the disk drives do not have a completely uniform and rigid shape during shipment because of the plastic bag or containers. The main insert compartments could be sized for a tight friction fit with the loaded disk drives; however, this might rip or tear the containers. Furthermore, it is undesirable to have the disk drives firmly wedged within the main insert compartments because it makes the disks drives difficult to load and remove, and damage can occur to the disk drives merely by loading or removing them. The central rib constrains the disk drives within their respective compartments and prevents any movement or displacement of the disk drives; however, the central rib is easily removed which allows the disk drives to be loaded and removed without damage and without undue physical effort. 
     The central rib in a first preferred embodiment is simply a substantially rectangular shaped extension protruding from the lower surface of the top cover. Other preferred embodiments are disclosed herein which provide different shapes of the central rib. Yet other embodiments are disclosed wherein the central rib is a separate piece which is not permanently attached to the top cover. 
     Like the main insert, the top cover and central rib may be made of expanded polypropylene or other well known molded packing materials. Additionally, it is contemplated within this invention that the central rib can be made of any type of suitable material which has the strength and resiliency to displace and hold the computer disk drives in their contact positions against the outer walls of their respective compartments. For example, the central ribs could be constructed of plastic, wood, or cardboard, or the central rib could be made of a sufficiently rigid inflatable member. 
     There are numerous advantages to the invention. First, motor fret can be substantially reduced, if not eliminated. No or minimal changes are required of either the main insert or the cardboard shell. In fact, the only required structural modification to the overall package is the inclusion of the central rib. The disk drives are easily inserted and removed from their respective compartments because the size of the compartments do not have to be modified. In addition to protection from vibration, the disk drives are still protected from normal shock which may occur during shipment (for example, inadvertent dropping or slamming of the package against another object). More importantly, the construction of the newer types of disk drives do not have to be modified to reduce motor fret. These and other advantages will become apparent from the description which follows, taken in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view illustrating a top cover and main insert of the anti-motor fret package of the invention; 
     FIG. 2 is a perspective view of the main insert placed in a cardboard shell, and illustrating the lower surface of the top cover having a central rib attached thereto; 
     FIG. 3 is a perspective view of the package illustrating the top cover placed over the main insert, and showing two flaps of the cardboard shell in a folded position; FIG. 4 is a fragmentary enlarged plan view taken along line  4 — 4  of FIG. 1; 
     FIG. 5 is an enlarged fragmentary vertical section taken along line  5 — 5  of FIG. 3; 
     FIG. 6 is an enlarged vertical section taken along line  6 — 6  of FIG. 5; 
     FIG. 7 is a greatly enlarged fragmentary perspective view of one preferred embodiment of the top cover, the view taken along line  7 - 13 ,  7 - 13  of FIG. 1; 
     FIGS. 8-13 each show greatly enlarged fragmentary perspective views of other embodiments of the top cover usable with the package of the invention; 
     FIG. 14 is a perspective view of a prior art top cover, specifically illustrating the lower surface thereof; 
     FIG. 15 is a perspective view of a prior art main insert and top cover; and 
     FIG. 16 is an enlarged fragmentary vertical section taken along line  16 — 16  of FIG.  15 . 
    
    
     DETAILED DESCRIPTION 
     FIGS. 1 and 2 illustrate the anti-motor fret package/container  10  of the present invention. As shown, the package  10  includes three major components, namely, a cardboard shell  12 , a main insert  14 , and a top cover  16 . Beginning first with the top cover  16 , it includes a reinforced/thickened edge  18  extending around the periphery or outer edge of the top cover  16 . A plurality of shock pads  20  and  22  are arranged on the upper surface of the top cover  16 . The shock pads are shown as having substantially box-like shapes with flat or planar exposed upper surfaces. Intermediate shock pads  22  have uniform heights H 1 . Two pairs of end shock pads  20  are provided which have uniform lower heights H 2  in comparison to the intermediate shock pads  22 . A center reinforcing flange  24  extends longitudinally along the top cover. This center flange  24  is simply a thickened or raised area which provides bending strength to the top cover. Each end of the top cover may include a handle extension  26  which eases removal of the top cover from the main insert. The pads  20  and  22  are mounted on the web portion  28  which traverses between the thickened edge  18  and the center flange  24 . 
     Referring now to FIG. 2, the top cover  16  has a lower or bottom surface  32  having a central rib  30  extending longitudinally therealong. The center rib  30  extends substantially perpendicular to the lower surface  32 . 
     The main insert  14  is characterized by a number of features to include end shock ribs  34  protruding from their respective ends of the main insert, and a plurality of lateral or side shock ribs  36  which extend laterally or transversely from the main insert  14 . End wall  38  defines the retaining structure at both ends, while side walls  40  define the retaining structure along the lateral sides of the main insert. One or more feet/base extensions  41  are positioned at the bottom or lower surface of the main insert. These extensions  41  are also seen in FIG. 5. A plurality of ledges  42  define upper ends of respective end shock ribs  34 . Recessed ledges  44  extend longitudinally along their respective lateral sides of the main insert. 
     Cardboard shell  12  is simply a cardboard box having end walls  46 , side walls  48 , bottom  49  (FIG.  5 ), end flaps  50  and side flaps  52 . Now referring to FIGS. 1 and 4, the main insert  14  includes a plurality of compartments  60  formed by a crisscross pattern of internal walls. One common arrangement for main insert  14  is a pair of longitudinally extending compartment rows wherein each of the compartments extends transversely from a center axis or center line of the main insert. This pair of rows is separated by a single central wall or longitudinal wall  54  extending longitudinally along the main insert. A plurality of transverse walls  56  interconnect longitudinal wall  54  and side walls  40 . Optionally, transverse walls  56  may include one or more flanges or ribs  58  which extend vertically along the transverse walls  56  and protrude inwardly into the defined compartment  60 . Disk drives located in their respective compartments  60  are shown as disk drives D. FIGS. 4 and 5 show no gaps between the drives D and the walls of their respective compartments; however, there are, in fact, small gaps which allow the disk drives to be easily loaded within or removed from their respective compartments. Each of the compartments  60  are further defined by an inner side wall  66  which itself forms one edge of the longitudinal wall  54 , each compartment also being defined by an outer side wall  64  which itself forms an interior surface or edge of outer side wall  40 . When a disk drive is loaded within a compartment  60 , the interior edge of the drive will be adjacent the inner side wall  66  and the exterior edge of the drive wall will be adjacent the outer side wall  64 . 
     Referring back to FIG. 2, once a package is loaded for shipment, the top cover  16  is placed over the main insert. The center rib  30  is aligned in the gap between the rows of drives D, and the center rib  30  pushes the drives D against their respective outer side walls  64  of their respective compartments  60 . Preferably, one end of the top cover  16  is placed adjacent the main insert, and the center rib  30  is progressively aligned and forced between the rows of drives D. When in place, the center rib  30  extends continuously between the rows of drives D and prevents any transverse or lateral movement of the drives D within their respective compartments  60 . 
     Referring now to FIG. 6, the center rib  30  is shown in its installed position wherein disk drives D have been forced against their respective outer side walls  64 . Accordingly, the primary or major gap which then exists between the walls defining the compartments  60  and the disk drives D is the gap between walls  66  and the interior edges  69  of the disk drives D. The disk drive D includes the platter or disk  70  which normally rotates in the manner as shown. An actuator assembly  72  is shown in its parked position in the landing zone. By preventing any lateral or transverse movement of the disk drive D within the compartment  60 , the platter  70  is unable to make its slight rotations or twitches which otherwise cause the motor fret. As also shown in FIG. 6, the lower surface  32  of the top cover sets flush against the upper surfaces of the disk drives D. The drives D are also in contact with the bottom surfaces  68  of their respective compartments  60 . Therefore, not only are the drives D constrained within the compartments to prevent lateral or transverse displacement, but also vertical displacement. 
     In terms of longitudinal displacement of the drives D in their compartments  60 , the center rib  30  imparts enough force on the disk drives to prevent any appreciable longitudinal displacement as well. Therefore, even longitudinal vibration or shock which is induced upon the package does not result deleterious effects upon the disk drives loaded in the package. 
     In order to ease the insertion of the central rib  30  between the rows of disk drives, the central rib may be provided with a slick plastic covering or sleeve (not shown). 
     Referring back to FIG. 3, yet another advantage of the invention is the specific construction and arrangement of the shock pads  20  and  22 . In order to best isolate the disk drives D from any vibration or movement when loaded, the cardboard shell should provide a tight contacting envelope or cover over the top cover  16  and the main insert  14 . In other words, it is undesirable to allow movement of the main insert and top cover within the cardboard shell. The main insert  14  fits tightly within cardboard shell  12  such that the ribs  34  and  36  contact the respective cardboard shell walls  46  and  48 . End shock pads  20  are slightly lower in height than intermediate shock pads  22  which allows end flaps  52  to set flush against the upper surfaces of end shock pads  20 . Then, side flaps  52  may be folded over to set flush against the upper surfaces of intermediate shock pads  22 . This arrangement of pads  20  and  22  allows the top portion of the cardboard shell to be in aligned contact with each of the shock pads  20  and  22 . 
     FIG. 7 more specifically illustrates the construction of the center rib  30 . As shown, the center rib  30  includes a main extension  80 , and a narrowed portion  82  which allows the rib  30  to be more easily placed in the gap between the rows of disk drives D during its initial contact with the drives D. FIGS. 8-13 illustrate variations of the center rib  30 , and can be considered other preferred embodiments of the top cover of the invention. FIG. 8 illustrates a center rib  84  having a main extension  86 , and a rectangular shaped end  88 . FIG. 9 illustrates a center rib  90  including a main extension  92 , and an arrow shaped end  94 . FIG. 10 illustrates another center rib  96 ; however, this center rib is not connected to the lower surface  32  of the top cover, but rather is a separate element which is wedged between the row of disk drives D. In this embodiment, the center rib  96  is a longitudinally extending member  98  having a rectangular cross section. FIG. 11 illustrates yet another rib  100  which is also separated from the top cover  16 . Rib  100  is shown as a longitudinally extending member having a semi-circular cross section including a notch or gap  104  extending longitudinally along the rib  100 . FIG. 12 shows yet another rib  106  which has a cylindrical body  108 . FIG. 13 shows a final arrangement of ribs wherein in addition to a central rib  109 , a pair of outside ribs  110  are provided which extend longitudinally along the exterior lateral sides of the top cover  16  and protrude from the lower surface  32  of top cover  16 . Rib  109  is in the same shape as rib  30 . Ribs  110  each include a main extension  112  and narrowed portions  114 . The purpose of these outside ribs  110  is to provide additional structure to support the upper exterior edges of the disk drives D once the top cover  16  is placed over the main insert  14 . These ribs  110  reside in the gaps which extend longitudinally between ledges  44  and the lower surface  32  of the top cover. 
     FIG. 14 illustrates a prior art top cover  200 , one which was used by the Applicant of this invention. As shown, this top cover  200  includes a plurality of shock pads  202 . However, this top cover  200  was used in a manner quite different from the present invention. Specifically, the shock pads  202  were mounted to the lower surface of the top cover, and the shock pads were placed in contact with the upper edges of the disk drives. The upper surface of top cover  200  was simply flat with no shock pads. With the present invention, it was found that by reversing the upper and lower surfaces such that the upper surface of the top cover placed the shock pads in contact with the flaps of the cardboard shell, there was better absorption and distribution of shock and vibration. 
     FIG. 15 illustrates components of a prior art container which include a main insert  204  and a top cover  206 . This particular main insert and top cover is one which has been used by Quantum, Inc. of Milpitas, Calif. As shown in the cross-section of FIG. 16, while a loaded disk drive D may be enveloped by the top cover  206  placed over the main insert  204 , there are no means to positively restrict or prevent displacement or movement of the disk drives D within the compartments. The compartments of this prior art container are defined by lower surface  208  of top cover  206 , side walls  212 , and lower or bottom surface  210 . As shown, there are small gaps between the disk drive D and side walls  212 , as well as gaps between lower surface  208  and the upper edges of the disk drive D. For illustration purposes, these gaps have been accentuated to illustrate the failure of this particular prior art container to effectively isolate the disk drive D from displacement caused by vibration during shipment. 
     As a subcombination, the top cover itself has utility. Regardless of the specific type of main insert used, a top cover which incorporates a central rib for contacting a disk drive and prevents displacement of the disk drive in its compartment is advantageous. 
     While the container of this invention has been described with respect to advantages in the shipment of products such as disk drives, it shall be understood that the present invention is not limited to application solely with disk drives. Vibration induced upon a large number of electromechanical devices can be damaging. Therefore, providing a means to effectively isolate the devices from vibration is particularly desirable when the device cannot be placed in packaging which inherently isolates the device from vibration. Human factors play a large part in how products are packaged. The more difficulty a user encounters when accessing a product within a package, the more undesirable that style of packaging is to the user. According to the present invention, the central rib is easily emplaced and removed by a user. The products loaded in the package are then easily removed, because there is no high friction arrangement between the products and the corresponding compartments. 
     Although the main insert disclosed herein has two rows of compartments, it shall also be understood that the present invention encompasses any package having at least one row of compartments. In a package having only one row, the central rib  30  would simply be positioned at a location to constrain lateral or transverse movement of the disk drives. Accordingly, the location of the “central” rib would result in the rib being placed in communication with one of the outside longitudinal edges of the top cover. 
     One aspect important to the present invention is that the central rib should remain in a fixed position once the top cover has been placed over the main insert. Therefore, the rib should not deform, twist, or otherwise displace during shipment. Additionally, the fit of the top cover and the main insert within the cardboard shell should be tight so that, if the package is subject to any vibrations or shock, the entire package must vibrate or displace in response to the induced vibration or shock. Because of the weight of the package and the tightly packed components, deleterious effects of smaller amplitude vibrations can be reduced or eliminated because the package as a whole has to displace or move in reaction to an induced vibration, and such smaller vibrations are absorbed without displacement. 
     This invention has been described with respect to various disclosed embodiments; however, it will be understood that other modifications can be effected within the spirt and scope of this invention.