Patent Application
20060261528
This invention relates generally to increasing the shock robustness of storage systems, and in particular embodiments to an apparatus for increasing the shock robustness of a storage system by encapsulating the system in a shock absorbing material.
Personal computers are well known, as are portable personal computers, and other portable electronic devices, such as digital music and video players and recorders, PDAs, and the like. Many portable devices include a hard drive disc drive for storing large amounts of data.
Electronic equipment such as laptops, mini disc players, mp3 players and the like are small and portable. Portable equipment is partially susceptible to mishandling and accidental dropping. Disc drives can suffer from shock damages if they are exposed to a sufficient shock or vibration.
Further, external vibrations and shock may be caused by packaging, transporting, and handling the disc drive. To reduce the possibility of damage, disc drives have been designed to meet certain desired shock specifications. For example, some disc drives use shock absorbers to reduce the damaging effects of shock or vibration to the device. In a portable device, the hard disc drive is frequently the component most sensitive to shock and vibration. In use, the disc in the hard disc drive rotates at a high speed and a read/write head rides very closely above the disc. The head/disc arrangement is very sensitive to both vibration and shock and is easily damaged by either.
A typical disc drive has one or more circular discs, coated on both sides with a thin layer of magnetizable material. These discs can be mounted on a spindle that rotates them at a constant, high speed. For each surface (the top and the bottom of each disc), the drive has a read/write head. These heads are mounted on an actuator assembly that moves them in toward the spindle or out toward the edge of the disc.
Typically, disc drives are designed to keep the heads flying in very close proximity to the surface of the discs. The air flow created between the heads and surface keeps the heads from touching the surface. If the head hits the surface sufficiently hard, for example in a portable device during vigorous activity, the head can damage the disc surface (and possibly the head). In particular, if the head hits the surface and damages a portion of the magnetizable coating, data stored on that portion of the disc may be lost. External vibrations and shock can damage the disc drive by causing the head to impact the disc.
Shock absorbers have used shock mounts to attach a bracket to the disc drive and isolate the disc drive from vibration and shock. The shock mount design protects the disc drive and its components from shock. In another shock mount design, a shock absorbent jacket is used to protect the disc drive from vibration and shock. The shock absorbent jacket is made of a shock absorbing material that encloses the disc drive.
Some prior art devices are flat and dependent purely upon the elastomer material properties to attenuate the shock magnitude. Typically, the thickness of the shock absorbing material is related to the material's shock absorbing capability. The thickness is limited by the location of the disc drive in a host device and physical space constraints. Thus, there is a need to reduce the overall size and the susceptibility to damage from shocks. In the case of small portable applications where internal space available is at a premium, the shock mount should meet certain specifications while occupying minimal space.
The present invention addresses these and other problems, and offers other advantages over the prior art by providing a shock mount for a disc drive to minimize adverse effects of external disturbances.
A shock mount assembly for a mounted data storage system is configured to receive the storage system therein. A shock mount is configured to at least partially surround the storage system and to fit in a housing. A plurality of shock absorbing protrusions extend from the shock mount. The protrusions are of a shock absorbing material and configured to hold the storage system at a spaced apart position from the housing and provide shock absorption therebetween.
As discussed previously, many small, portable devices require large storage capacities. Examples include personal data assistants (PDAs), digital music players and audio recorders, video recorders and playback devices, etc. In order to meet the demands for a high storage capacity, there has been an ongoing effort to reduce the size of data storage devices. However, as the size of components are reduced, the component strength is also reduced thereby making the data storage device more susceptible to damage from impact, vibrations, or the like. The problem is exacerbated because by their very nature, portable devices are much more likely to experience impacts or vibrations than fixed devices. Examples include a user dropping a digital music player, or attempting to use a portable device while engaged in vigorous activities. Further, the design of any shock absorber can be limited because in some instances, the storage device must fit in certain preassigned packages such as a compact flash (CF), PCMICA configuration, or other formats. Further, the shock absorber itself must be bale to dissipate relatively large shock forces, even when the device is used in relatively normal situations. For example, if a device is dropped from 1.5 meters onto a hard surface, the impact can translate into a shock of about 5,000 G with a duration of 0.1 ms. The direction of this impulse is unpredictable and depends on the angle in which the portable device impacts the hard surface. In order to address the problems of mechanical shocks and vibrations applied to data storage devices, various shock absorbing and mounting techniques have been used such as those described previously.
To overcome the limitations in the prior art described above, the present invention includes an apparatus for increasing the robustness of a disc drive. Generally, the present invention includes a storage system that has a shock absorbing material encapsulating a storage device. A shock mount comprises an elastomer that at least partially encompasses the disc drive. Molded shock absorbers in the elastomer hold disc drive firmly in place within the embedded application. In one configuration, a plurality of shock absorbing protrusions extend toward the disc drive and are configured to hold the data storage device at a position spaced apart from the housing or drive and provide shock absorption therebetween. In a preferred embodiment, there is one protrusion extending from the first surface of each corner, one protrusion extending from the second surface of each corner, one protrusion extending from the anterior surface of each corner and one protrusion extending from the posterior surface of each corner. (See generally
The inventive shock mount design has extended shock absorption features. While some previous designs like the corner shock mount are flat and dependent purely upon the elastomer material properties to attenuate the shock magnitude, the shock mount of the present invention has shock absorbing protrusions which are more efficient at reducing shock in a confined space. Shock absorption in the present invention arises from elastomer material properties of the materials as well as shape of shock absorbers. The protrusions are designed to be highly compressed during shock, but take up minimal space in a normal condition. In a preferred embodiment, the protrusions are strategically placed around the shock mount to provide protection in x-y-z axis. The designed shock mount lowers shock input to the storage device, regardless of impact direction. To obtain similar protection with an elastomeric enclosure without the protrusions requires that the enclosure be much thicker. The present mount is particularly useful in portable devices such as digital audio and video players and recorders, and the portable equipment which uses a storage device.
In the following description of preferred embodiments, reference is made to the accompanying drawings which form a part hereof, and in which is shown by way of illustration a specific embodiment in which the invention may be practiced. It is to be understood that other embodiments may be utilized and structural changes may be made without departing from the scope of the preferred embodiments of the present invention.
Referring to
Referring to
Turning now to one specific example,
The shock mount is preferably molded of an elastomeric material with high damping characteristics such as ethylene propylene dimer (EPDM). In one specific implementation, the shock mount have a Hardness (durometer measurement) Shore A of between about 10 to 50, preferably for the 1.8 mm protrusion, the material is EPDM 30 shore A. Other shock absorbing materials may require different configurations of the protrusions in terms of thickness and surface area. The configuration preferably prevents the material from “bottoming out” and maximize the shock absorbing power.
The shock mount may also be made of any desired material such as natural or synthetic rubber (or its compounds) or plastic. Example rubber candidates are: high damping butyl, impregnated rubber (e.g., Silicone), a thermoplastic elastomer, dispensable e.g., Polyurethane), etc. Example plastics: acrylonitrile-butadiene-styrene copolymer, polypropylene, polyethylene, etc. Other plastic alternatives or other shock absorbing materials can be used.
Referring to
The dimensions and properties of the mount affect the drop height survivability and can be chosen as desired. Referring to
In another embodiment shown in
The protrusions described herein can be configured to extend from the shock mount inward and in a direction toward the disc drive, or can be configured to extend in a direction outward from the shock mount toward the housing. Further, in some embodiments, both types of protrusions are used. For example, in
While a particular embodiment is shown here, this is not intended to be limiting. Although the present invention is described in connection with any CF (compact flash) type II product, the principles of the invention are applicable to other devices as well as other form factors in a disc drive. Furthermore, the application of shock mount can extend to CF type I devices and the invention is not limited to the illustrated dimensions or configurations. Hence, the presently disclosed embodiments are illustrative and not limiting. Also, the particular dimensions and materials described herein are, in general, not limiting but are intended to be illustrative. Hence while the presently disclosed embodiments are for a particular size and mass, in the future hard disc drives may be of other sizes and shapes, and the present shock mounting in general is applicable to changes in the disc drive and the housing. Moreover the disclosed details of the shock mount protrusions and their surface areas are only illustrative and are intended to provide a certain amount of shock and vibration protection; if greater or lesser amounts of shock protection are needed, the size, thickness, and materials of the shock mount protrusions can be changed.
The invention provides a shock absorber apparatus for encapsulating a disc drive, where the shock absorbing apparatus includes a molded polymeric enclosure sized to carry a disc drive therein. The enclosure has protrusions extending from the inner or outer surfaces of the comers of the shock mount where the protrusions distribute shock loads in such a manner as to reduce the effect on the drive itself. In preferred embodiments, the shock mount and protrusions are the form of a single molded component and therefore are the same material. However, in other embodiments, the materials of the body of the shock mount can differ from the protrusions.
The present specification discloses preferred embodiments of an apparatus and process for increasing the shock robustness of disc drives by encapsulating the disc drive in a shock absorbing material. The preferred embodiments of the invention have been presented for the purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise forms disclosed above. Many modifications and variations are possible in light of the above teaching. For example, other form factors and shapes of disc drives may be accommodated by the shock absorber apparatus of the present invention. The location of shock impact may vary and the location and configuration of the protrusions may change as desired. The shock mount can be implemented with any storage device and is not limited to the disc drive storage system set forth herein. Although the shock mount and disc drive illustrations herein are generally square or rectangular shaped, the present invention is not limited to these shapes or configurations.
