Abstract:
A shock mount structure is shown that has one position wherein shock mount members positioned at the corners of the device are contained within the length, width, and height of the form factor with which the device complies and a second position wherein the elastomeric corner members violate the form factor, but are positioned to impact a planar surface, toward which the device is dropped, before any portion of the device, irrespective of the attitude of the device as it approaches the planar surface. To assure protection, the elastomeric corner shock mount elements are urged toward the second position by integral springs and are manually movable to the first position by overcoming the biasing force of the springs.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention pertains to shock mounting structures and more particularly to a shock mount structure that may be contained within the dimensions of a form factor, but is movable to a position violating the form factor, but protecting the device when dropped in any attitude.  
         BACKGROUND OF THE INVENTION  
         [0002]    Shock isolation is important for all precision devices such a disk drives and becomes more important for current small devices, such as those confined within a Personal Computer Memory Card International Association (PCMCIA) or microdrive form factors, which are more likely to be subject to casual and frequent transport and accidental dropping. This is particularly true when more than one device must be used in a single bay of a system, requiring the devices to be frequently interchanged and handled.  
           [0003]    In many cases it is adequate to provide shock protection at the corners of a device within the form factor. On most occasions a device falls randomly with one corner lower to encounter the initial impact with the surface above which the device is dropped. However, such protection is ineffective when the impact is nearly face-flat with the surfaces substantially parallel at the moment of engagement or if dropped on an edge. This type of impact is particularly dangerous since it represents the worst case for disk drive head-disk interface failure and spindle failure modes. Shock protection should be adequate when the device is dropped irrespective of device orientation when impact occurs with the underlying surface. Further, the entire device must be contained within the dimensions of the form factor when installed for use within a host apparatus. However, when the device is not installed it is permissible to violate the form factor.  
         SUMMARY OF THE INVENTION  
         [0004]    The invention utilizes movable, integral shock mount members at each corner of a miniature electronic device such as a PCMCIA type II form factor or a microdrive form factor. In one position the elastomeric corner portions are flush with the exterior of the device and within the dimensions of the form factor. When the device is removed from the host device, the elastomeric corner members may be rotated to a position where mechanical shock protection is provided if the device is inadvertently dropped. This protection is important, since such small devices are at times difficult to handle. The structure of the invention is capable of maintaining the form factor of a micro-sized device when the device is in use, but violate the form factor when the device is handled while removed from the host apparatus to protect the delicate parts within the device from damage that would render the device inoperative. To assure mechanical protection of the device, when not mounted in a host and confined to the form factor, the shock mount corner members are biased toward the form factor violating protective position. The shock mount members are manually movable, against the biasing force, to a position within the form factor for reinstallation of the device in the host apparatus.  
           [0005]    In addition to being biased ninety degrees to the from factor violating, protective position, the shock mount corner members are biased outward. In the protective position, with the shock mount members rotated and biased outward, the shock mounts will be the first to engage any planar surface over which the device may be dropped irrespective of the attitude of the device at the instant of impact.  
           [0006]    In another mode of practicing the invention, elastomeric shock mount members are mounted at truncated corners of the device within the form factor when in a first position. When moved to a second position, the sides of the elastomeric shock mounts move outward parallel to the device sides to violate the form factor and upper and lower surfaces of the elastomeric shock mount are distorted to exceed the third dimension of the form factor. With the shock mount in the second position, this embodiment also protects the device if dropped toward a planar surface irrespective of device attitude at contact.  
           [0007]    Small devices such as micro drives are not only delicate precision structures, but due to the small size are often difficult to handle and properly secure for transport. When used with a portable host apparatus having limited resources for receiving auxiliary apparatus, it is often necessary to interchange devices to achieve multiple functions. When not installed, miniature devices are occasionally casually handled and subject to being dropped. Thus, mechanical protection of micro devices is required to have the device and any data carried by the device reliably available. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a plan view of a device within a PCMCIA type II form factor which incorporates the integral shock mount structure of the present invention.  
         [0009]    [0009]FIG. 2 is a plan view, similar to that of FIG. 1, showing the integral shock mount structure of the present invention in the environment of a microdrive form factor.  
         [0010]    [0010]FIG. 3 is a view of an integral corner shock mount structure taken along line  3 - 3  of FIG. 2, with internal structural details shown in phantom view.  
         [0011]    [0011]FIG. 4 is a view of an integral corner shock mount taken along line  4 - 4  of FIG. 1 with certain obscured portions illustrated by dashed lines.  
         [0012]    [0012]FIG. 5 is a side elevation of an elastomeric shock mount of the present invention with internal details shown in phantom view.  
         [0013]    [0013]FIG. 6 is a view of the member illustrated in FIG. 5 taken along line  6 - 6  of FIG. 5.  
         [0014]    [0014]FIG. 7 is a plan view of a corner portion of a device frame including a post structure for receiving the shock mount member of FIG. 5.  
         [0015]    [0015]FIG. 8 is an axial end view of the slotted post of FIG. 7 taken along line  8 - 8 .  
         [0016]    [0016]FIG. 9 illustrates a second embodiment of the invention showing an elastomeric shock mount at the truncated corner of a device in a first position within the device form factor.  
         [0017]    [0017]FIG. 10 shows the apparatus of FIG. 9 with the shock mount in a second position in which then device form factor is violated.  
         [0018]    [0018]FIG. 11 illustrates the projection about which the shock mounts of FIGS. 9 and 10 are mounted.  
         [0019]    [0019]FIG. 12 is an elevation, partially in section, taken along line  12 - 12  of FIG. 9.  
         [0020]    [0020]FIG. 13 is an elevation, partially in section, taken along line  13 - 13  of FIG. 10. 
     
    
     DETAILED DESCRIPTION  
       [0021]    [0021]FIG. 1 illustrates a device  10  in the form of a Personal Computer Memory Card International Association (PCMCIA) type II standard or form factor. The form factor dimensions are 85.6×54.0×5.0 millimeters. The four elastomer shock mount corner members  11 ,  12 ,  13 ,  14  are shown with the two lower members  13 ,  14  in the operative position wherein they have been manually rotated to be contained within the form factor dimensions and the upper members  11 ,  12  are in the protective position wherein they are rotated a quarter turn and biased outward (both of which motions cause a violation of the form factor).  
         [0022]    [0022]FIG. 2 is similar to FIG. 1, but shows the shock mounts of the present invention in the environment of a device  20  having a microdrive form factor which is contained within the dimensions of 42.8×36.4×5.0 millimeters. The shock mounts  21 ,  22  at the upper corners are shown in the protective position and the shock mounts  23 ,  24  at the lower corners in the operative position.  
         [0023]    [0023]FIG. 3 shows one of the elastomeric shock mount members  22  in the protective position with concealed portions of the assembly in phantom view. The shock mount assembly  22  (as seen in FIGS. 5 and 6) has an elastomer portion including a cylindrical opening  28  extending from the lower surface  30  and includes an enlarged portion  31 . Elastomeric member  28  is formed with two inserts  34  and  35 . Leaf spring insert  34  is captured within the molded elastomer and bisects the cylindrical opening  29 . The second insert is a spring member  35  which has flange portions  37  captured by the molded elastomer and end portion  38  that engage the wall surface  40  of device  20  and biases the shock mount away from the device frame when not confined in the operative position within the form factor. A recess  42  in the elastomer member  28  surrounding the spring member  35  receives the compressed spring terminal end portions  38  when the shock mount is manually urged to the operative position. An enlarged opening  43  in spring member  35  enables the elastomeric material at the base of the cylindrical opening  28  to be displaced as the shock mount is assembled onto the device.  
         [0024]    As shown in FIGS. 7 and 8, the device frame  45  includes a post member  47 , formed as an integral part of the frame, that is generally cylindrical and includes an intermediate enlarged portion  48  and a terminal slotted opening  50  which receives the leaf spring insert  34  in the assembled condition. As shown in FIG. 8, the slotted opening  50  has substantially parallel side portions  51  at the center of the slot which closely confine spring  34  and diverging surfaces  52  extending to the slot opening at the periphery of post  47  to prevent localized stress on spring  34  when the shock mount assembly is assembled about post  47  and rotated a quarter turn to the operative position.  
         [0025]    The elastomeric shock mount assembly  22  is assembled about the supporting post  47  by forcing the elastomeric material surrounding the cylindrical opening base over the enlarged portion  48  of post  47  to position the enlarged post portion in the enlarged portion  31  of the elastomer cylindrical opening  29 . Such assembly is effected with the shock mount in the rotated protective position so that the leaf spring  34  is received in the post slot  50 . When the shock mount  22  is assembled about the post  47 , the spring  35  urges the shock mount outward to cause the lower surface  54  of the post enlarged portion to engage the wall portion  55  of the elastomer enlarged portion extending from the cylindrical opening  29 . The shock mount  22  is placed in the operational position within the device form factor by rotating the shock mount 90 degrees against the biasing force of leaf spring  34  and compressing spring  35  to place the shock mount within the dimensions of the device form factor.  
         [0026]    [0026]FIG. 4 illustrates the shock mount  11  in the protective position (as also shown in the assembly view of FIG. 3) with the mount rotated and biased away from the confronting device wall portion  60  by the spring  35  (not visible in the view of FIG. 4). The upper edge  61  of shock mount  11  in cooperation with the corresponding edges of the other three shock mounts defines a plane above the device surface  63 . Similarly, the lower edge  63  in cooperation with the corresponding lower edge surfaces of the other three shock mounts define a plane below the device bottom surface  65 . There are also planes defined about the sides and ends of the device that function, in combination, to completely surround the device. For example, these include a plane determined by the shock mount  11  edge  67  and the shock mount  12  edge  68  which, with a plane defined by the edge  69  and the corresponding edge of shock mount  12 , establish intersecting planes beyond the device end surface  71 . Accordingly, with the shock mounts in the protective position, there is no attitude that the device can present when approaching a planar surface wherein the shock mounts will not engage such planar surface prior to any portion of the protected device.  
         [0027]    Another form of the invention is illustrated in FIGS. 10 through 13. In this embodiment shock mounting is provided for a device  74 , such as the microdrive of FIG. 2, with elastomeric shock mount members  75  mounted at the truncated corners of the device  74 .  
         [0028]    In this embodiment, the elastomeric corner shock mount  75  is likewise within the device form factor in a first position as shown in FIG. 9. Here the shock mount side surfaces  76  and  77  are respectively coplanar with device side surfaces  78  and  79 , while upper and lower surfaces of shock mount and device are likewise coplanar as seen with device upper surface  81  and shock mount upper surface  82 . When shock mount  75  moves outward to the second position, as illustrated in FIG. 10, the shock mount side surfaces  76  and  77  translate to a position respectively parallel to device sides  78  and  79  and outside the dimensions of the form factor determined by the dimensions of device  74 .  
         [0029]    Each shock mount is supported at a truncated device corner by a rectangular projection  84 , that has at the terminal end a bulbous portion  85 , and is received in a recess  86  extending into the shock mount. With the shock mount in the first position, the project end portion  85  is received in the enlarged terminal end  87  of the shock mount recess. It will also be noted that the recess  86  includes an intermediate relieved portion  88  (FIG. 12) which serves as a detent when the shock mount is moved outward along projection  84  to the second position.  
         [0030]    [0030]FIG. 11 illustrates the rigid projection  84  extending from the device  74  to support the elastomeric shock mount  75 . The projection  84  terminates at the distal end in an enlarged, bulbous portion  85 . The projection  84  has flat parallel sides  90  and thus there is no increase in dimension from side to side. Projection  84  being rectangular (non-round) resists any rotation of the shock mount as it is moved between the first and second positions.  
         [0031]    When the shock mount is moved from the first position shown in FIG. 12 to the second position shown in FIG. 13, the bulbous terminal end portion  85  of projection  84  moves from the enlarged terminal end  87  of recess  86  to the only slightly relieved portion  88  of the recess. The enlarged end  85  of projection  84  causes the elastomer of the shock mount to deform. Since the increased dimension of the projection occurs toward the upper and lower surfaces of the device  74 , the distortion of the shock mount elastomer is largely limited to the vertical direction as illustrated in FIG. 13. The upper surface  82  of the shock mount is caused to project above the plane of the device upper surface  81  and the lower surface  90  of the shock mount is similarly deformed to project beyond the plane of device lower surface  91 .  
         [0032]    With the shock mounts moved to the second position away from the truncated corners of the device, the shock mounts violate every dimension of the form factor. Thus, should the device drop toward a planar surface one or more of the elastomeric shock mount members will make the first contact with such planar surface irrespective of the attitude of the device when contacting the surface.  
         [0033]    While the invention has been shown and described with respect to preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and detail may be made without departing from the scope and teaching of the invention. For example, various interconnection structures might be used to mount the corner shock mount members to the device while enabling movement between the operative position within the form factor and the protective position where the form factor is violated. Biasing toward the protective position could be implemented by a more complex, but single spring element in cooperation with a track and stop elements which both limit rotation of the shock elements and control separation between shock elements and the drive as the shock elements are both rotated and moved outward by a single composite motion. Accordingly, the apparatus herein disclosed is to be considered merely illustrative and the invention is to be limited only as specified in the claims.