Abstract:
A removable disc drive cartridge providing an improved combination of shock protection and electrical alignment (registration) of a enclosed removable disc drive.

Description:
This application is being filed as a non-provisional patent application under 37 C.F.R. 1.53(b). 
   FIELD OF THE INVENTION 
   This invention relates generally removable disc drives, also referred to as disc drive cartridges, and in particular to a disc drive cartridge configured to provide an improved combination of shock protection and electrical interface alignment (registration) to other computer hardware. 
   BACKGROUND OF THE INVENTION 
   A removable disc drive cartridge is a type of removable media that is employed to store and to physically transport data between two different locations. Typically, a disc drive cartridge transports data between two different computers that are each located at different locations. Other types of removable media, such as a compact disc (CD), a digital video disc (DVD), a tape cartridge or a flash memory key can also be used to physically transport data between two different computers. 
   Patents and patent publications that relate to the general subject matter of removable disc drive cartridges include U.S. Pat. No. 4,941,841 to Darden, U.S. Pat. No. 5,837,934 to Valavanis, U.S. Pat. No. 6,154,360 to Kaczeus, and U.S. 2005/0257949 to Lalouette. Differences between the subject invention and these patents and patent publications will be described in the following invention description. 
   SUMMARY OF THE INVENTION 
   The invention provides an improved combination of shock protection and electrical interface alignment (registration) for a removable disc drive cartridge. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The objects and features of the invention can be better understood with reference to the claims and drawings described below. The drawings are not necessarily drawn to scale, and the emphasis is instead generally being placed upon illustrating the principles of the invention. Within the drawings, like reference numbers are used to indicate like parts throughout the various views. Differences between like parts may cause those parts to be indicated by different reference numbers. Unlike parts are indicated by different reference numbers. 
     For a further understanding of these and objects of the invention, reference will be made to the following detailed description of the invention which is to be read in connection with the accompanying drawing, wherein: 
       FIG. 1A  illustrates an exploded view of a removable disc drive cartridge. 
       FIG. 1B  illustrates the bottom side of the disc drive that includes (4) mounting holes that are provided with the disc drive. 
       FIG. 2A  illustrates a top-down view of a plurality of mounting and shock absorbing components residing within an embodiment of the bottom portion of the disc drive cartridge enclosure, in accordance with the invention. 
       FIG. 2B  illustrates a side view of an embodiment of individual mounting and shock absorbing strut of  FIG. 1A . 
       FIG. 2C  illustrates a perspective view of the embodiment of individual mounting and shock absorbing strut of  FIGS. 2A-2B . 
       FIG. 3  illustrates an exploded view of a removable disc drive cartridge enclosure including an elastomeric outer rear mounting and shock absorbing component. 
       FIG. 4  illustrates an exploded view of a removable disc drive cartridge enclosure including a rear mounting and shock absorbing component that is overmolded around a rear side of the bottom portion and the top portion of the enclosure. 
       FIG. 5A  illustrates a close up view of holes located along the left side and the right side (not shown) of the disc drive that are configured to engage snap hooks. 
       FIG. 5B  illustrates a close up view of hooks located within the top portion of the enclosure that are configured to snap assemble and engage the holes of  FIG. 5A . 
   

   DETAILED DESCRIPTION OF THE INVENTION 
     FIG. 1A  illustrates an exploded view of an embodiment of a removable disc drive cartridge  100 . As shown, the removable disc drive cartridge  100 , also referred to as a cartridge  100 , is comprised of an enclosure  150  that includes a top portion  130  and a bottom portion  110 . The top  130  portion and the bottom  110  portion are shaped and sized to fit together to form the enclosure  150  that encloses a cavity within which a disc drive is located and protected. The enclosure  150  is configured to substantially surround and to protect a disc drive  120  from sudden movements (shocks), such as for example, caused by an impact between the enclosure and another object. 
   The disc drive  120  has a front side  122   a , left side  122   b , a right side  122   c , rear side  122   d , top side  122   e  and bottom side  122   f  (Shown in  FIG. 1B ) A plurality of electronic connectors  124  protrude from the front side  122   a  of the disc drive  120 . The electronic connectors  124  are configured to electronically connect to a complementary set of electronic connectors provided within a receiving bay (not shown) of a host computer or a peripheral of a host computer (not shown). 
   The enclosure  150  is configured to provide an opening  116  within its front side  112   a  to allow passage of electronic connectors  124  protruding from the front side  122   a  of the disc drive  120 . In the embodiment shown, the front side  112   a  of the bottom portion  110  of the enclosure  150  provides the opening  116  within the enclosure  150 . In other embodiments, the opening  116  can be provided within the top portion  130  of the enclosure  150 . 
   Four screws  114   a - 114   d  can be each inserted through a separate opening, each proximate to a mounting and shock absorbing component (See  FIG. 2A ), and located in the bottom surface of the bottom portion  110  of the enclosure  150 . The screws  114   a - 114   d  are configured to mate with screw holes located on the bottom surface of the bottom portion  110  of the enclosure  150  (Shown in  FIG. 1B ) 
     FIG. 1B  illustrates the bottom side (surface)  122   f  of the disc drive  120  that includes (4) mounting locations  126   a - 126   d  that are manufactured as part of the disc drive  120 . In this embodiment, each mounting location  126   a - 126   d  is implemented as a screw hole configured to receive a screw  114   a - 114   d  (Shown in  FIG. 1A ). As shown, each mounting location  126   a - 126   d  is configured provide a physical (mounting) attachment between the disc drive  120  and the bottom portion  110  of the enclosure  110  (Shown in  FIG. 1A ). 
     FIG. 2A  illustrates a top-down view of a plurality of mounting and shock absorbing components  212   a - 212   d  manufactured as part of an embodiment  210  of the bottom portion  110  of the disc drive cartridge enclosure  150 , in accordance with the invention. As shown, (4) mounting and shock absorbing components  212   a - 212   d , also referred to as mounting and shock absorbing struts  212   a - 212   d  or struts  212   a - 212   d , are configured to attach to the bottom side  122   f  of the disc drive  120 . 
   Each strut  212   a - 212   d  includes an opening  214   a - 214   d  configured to allow access to each of the mounting locations  126   a - 126   d  residing on the bottom side  122   f  of the disc drive  120 . In some embodiments, a screw is configured to be inserted upwards and rotated through each of the openings  214   a - 214   d  and respectively into and engaging each of the screw holes (mounting locations)  126   a - 126   d  of the bottom side  122   f  of the disc drive  120  in order to form an attachment between each strut  212   a - 212   d  and the disc drive  120 . 
   In accordance with the invention, the struts  212   a - 212   b , also referred to as the front struts  212   a - 212   b  that are located along the front side of the bottom portion  110  of the enclosure  150 , are configured to provide rigid support to the front side of the disc drive  120  and rigid support to the position of the electronic connectors  124  within the enclosure  150 . In some embodiments, the struts  212   c - 212   d , also referred to as the rear struts  212   c - 212   d , also provide the same rigid support as the front struts  212   a - 212   b . In other embodiments, the rear struts  212   c - 212   d  provide less rigid and more flexible support, by being configured for more deflection in response to a shock (force), than any deflection provided by the front struts  212   a - 212   b  in response to a shock (force). 
   Rigid support of the position of the electronic connectors  124  within the enclosure  150  enables proper alignment (registration) of the electronic connectors  124  in order for the electronic connectors  124  to connect with complementary electronic connectors located and positioned within a bay of a computer or peripheral within which the cartridge  100  is to be installed (not shown). 
   In some embodiments, the rigid forward struts  212   a - 212   b  are made from, Acrylonitrile Butadiene Styrene (ABS) plastic or some other metallic material such as aluminum or magnesium, for example. In accordance with the invention, the forward struts  212   a - 212   b  are not made from elastomeric materials, such as rubber or materials having deflection properties of rubber. Elastomeric materials do not provide sufficient rigid support for the electronic components  124 . 
   Some prior art removable disc cartridges require use of an intermediate electronic connector, also referred to as an interposer, to connect the electronic connectors  124  with the complementary electronic connectors located and positioned within a bay of a computer or peripheral within which the cartridge  100  is to be installed. Interposers create additional cost, interfere with signal integrity and can cause reliability issues. 
   Like embodiments of the invention, other prior art removable disc cartridges do not require use an interposer and provide an opening through which the electronic connectors  124  may pass through and protrude from the enclosure  150  in order to connect to the complementary electronic connectors located and positioned within a bay of a computer or peripheral within which the cartridge  100  is to be installed. 
   Unlike the embodiments of the invention, the aforementioned other prior art does not provide sufficiently rigid support to the front end  122   a  of the disc drive  120  and consequently, the front end  122   a  and the electronic connectors  124  can become misaligned within the enclosure  150  of the cartridge  100 . As a result, the electronic connectors will often not properly connect with the complementary electronic connectors when installing the cartridge  100  within a bay of a computer or peripheral. This type of circumstance is inconvenient for users of the removable disc cartridge  100 . Embodiments of the invention are designed to avoid this type of circumstance. 
     FIG. 2B  illustrates a side view of an embodiment of an individual mounting and shock absorbing strut  212  of  FIG. 1A . This side view shows a near longitudinal side  220   a  of the strut  212 . The strut  212  includes a lower portion  216  and an upper portion  218 . A lower portion of the strut  212  rises above a wall of the bottom portion  110  of the enclosure  150  at approximately a 45 degree angle. The upper portion  218  of the strut  212  is oriented approximately parallel to the wall of the bottom portion  110  of the enclosure  150 . Both the lower  216  and upper  218  portions are approximately 3 mm in thickness. A top surface of the lower portion  216  is approximately 12 mm in length and a top surface of the upper portion is approximately 6 mm in length (as shown). The top surface of the upper portion  218  is approximately 8.5 mm above the top surface of the wall of the bottom portion  110  of the enclosure  150 . 
     FIG. 2C  illustrates a perspective view of the embodiment of individual mounting and shock absorbing strut  212  of  FIGS. 2A-2B . The width of the lower  216  and upper  218  portions is approximately 6 mm. The opening  214  is circular in shape and has a diameter of approximately 1 mm. The opening  214  is centered between the near longitudinal edge  220   a  and a far longitudinal edge  220   b  of the top surface of the strut  212 . 
   Each strut  212   a - 212   d  is configured to deflect vertically and/or horizontally to counteract potential forces applied to the enclosure  150  from vertical and/or horizontal directions. A particular deflection of a strut in a direction can be quantified in terms of an amount of energy required to cause that particular deflection, also referred to as a strain energy. 
   Each strut  212   a - 212   d  is configured for a vertical (Y axis) down deflection caused from dropping the cartridge  150  (oriented top side up and bottom side down), including a disc drive  120 , from a height of one meter onto a rigid floor. Impact between a bottom side of the bottom portion  110  of the enclosure  150  with the floor creates an upward force causing a downward deflection of the struts  212   a - 212   d . For this type of drop, the bottom side (not shown) of the cartridge  150  physically impacts the floor while being oriented parallel to the floor. 
   Each strut  212   a - 212   d  is also configured for deflection towards the front side  122   a  or the rear side  122   d  (Z axis) or towards the left side  122   b  or the right side  122   c  (X axis) of the enclosure  150  in response to a force (shock) applied to the enclosure  150 . 
   In one embodiment, the cartridge  150  has dimensions of 24.5 mm (height)×85.7 mm (width)×111.9 mm (length). In some embodiments, removable disc drive cartridges can be dimensioned to comply with standards associated with a Standard Form Factor (SFF). Under a first variation of the SFF standard, a disc drive has a height of 9.5 cm and under a second variation of the SFF standard, a disc drive has a height of 12.5 cm. 
   For example, under the first variation of the SFF standard, a disc drive has dimensions of 9.5 mm (height)×69.85 mm (width)×100.2 mm (length). When enclosed within the enclosure  150  having a 2 mm wall thickness, there remains (24.5−9.5) mm−(2 walls)(2 mm/wall)=11 mm of vacant height (Y axis) space within the enclosure  150 , (85.7−69.85) mm−(2 walls)(2 mm/wall) mm=11.85 mm vacant width (X axis) space within the enclosure  150 , and (111.9−100.2)−(2 walls)(2 mm/wall)=7.7 mm vacant length (Z axis) space within the enclosure  150 . 
   When the disc drive  120  is centered within the enclosure  150 , the vacant space in any dimension (height, width or length) is divided into two separate portions that are each located on opposite sides of the disc drive  120 . Each separate portion is referred to as sway space. For the example described above, the dimensions of the sway space is 11 mm/2=5.5 mm of sway space in the height dimension (Y axis), 11.85 mm/2=5.925 mm sway space in the width dimension (X axis) and 7.7 mm/2=3.85 mm of sway space in the length dimension (Z axis), when the disc drive  120  is centered within the enclosure  150 . 
   Preferably, for a force (shock) applied in a given direction, the strut should not deflect so far that the disc drive  120  physically impacts a wall of the enclosure  150 . For example, considering that the struts  212   a - 212   d  each have a height dimension of approximately 8.5 mm above the bottom wall of the enclosure  150 , when deflecting in the vertical down direction, a deflection of greater than 8.5 mm would cause the disc drive  120  to physically impact the bottom wall of the enclosure  150 . Hence, each strut  212   a - 212   d  should vertically deflect less than 8.5 mm from the force (shock) of the bottom side (wall) of the enclosure impacting a rigid floor from a fall of the enclosure  150  and the enclosed disc drive  120  from a height of one meter. 
   Like wise, if the disc drive  120  is centered within the enclosure  150 , the (X axis) deflection of the struts  212   a - 212   d  should be limited to 5.925 mm in a direction along the (X axis) and limited to 3.85 mm in a direction along the (Z axis). 
   Notice that the disc drive  120 , when supported by the struts of  FIGS. 2A-2C , is located approximately 8.5 mm, minus a small deflection to support the weight of the disc drive  120 , above the wall of the bottom portion  110  of the enclosure  150 . This location is not exactly centered within the cavity formed by the enclosure given that the vertical (Y axis) vacant space is 11.85 mm. If centered, the disc drive  120  would be located approximately 11/2=5.5 mm above the wall of the bottom portion  110  of the enclosure  150 . 
   In other embodiments, the configuration of the struts  212   a - 212   d , specifically the shape and size of the struts  212   a - 212   d , is altered to support the disc drive  120  at other heights above the top surface of the wall of the bottom portion  110 . For example, the struts  212   a - 212   d  can be configured to have a height of 5.5 mm instead of 8.5 mm. In one embodiment, the angle of the strut  212   a - 212   b  can be altered to be less than 45 degrees, instead of equaling 45 degrees, as shown in  FIG. 2B . This would enable the disc drive  120  to be centered within the cavity. 
   The mass of the disc drive  120  is typically between 80-140 grams. The mass of an enclosure made from ABS plastic is approximately 15 grams. A disc drive  120  is typically designed to withstand an impact of 800 G without sustaining serious damage. The energy of a fall of a combined mass of 155 grams (0.155 kilograms) equals 0.155 kilograms×9.81 Newtons/kilogram×1 meter=1.5 Newton Meters (Joules) 
   The energy required to cause a specified deflection, also referred to as the strain energy, is a function of the amount of deflection squared times one-half of a spring constant. Hence, a spring constant equal to approximately 111000 Newtons/kg would correspond to strain energy of 1.5 joules for a deflection amount of approximately 5.2 mm ((0.0052 m)**2) (111,000)/2=1.5 joules 
   For example, a spring constant equal to approximately 195,000 Newtons/meter would correspond to strain energy of 1.5 joules when deflecting approximately 3.9 mm. In order to limit the impact force to below 800 G, the struts  212   a - 212   d  must collectively absorb the strain energy of a 1 meter drop without imposing an acceleration on the disc drive greater than 800 G. The acceptable spring constant for the combined supporting struts employed lies within the range of approximately 111,000 newtons per meter to 195,000 newtons per meter. 
   In many embodiments, each strut  212   a - 212   d , as designed and manufactured, is likely to have a unique and different spring constant of deflection for a direction along each of the X, Y and Z axes. For example, a strut  212   a - 212   d  may have a spring constant of deflection of 120,000 in the Y axis direction, by have a spring constant of 200,000 in the X axis direction and 250,000 in the Z axis direction. 
   In accordance with the invention, a substantially rigid strut  212   a - 212   b  is not intended to include an entirely rigid strut, such as a strut made from a little deflecting or non-deflecting material. A substantially rigid strut  212   a - 212   d  is configured to provide at least a minimum (greater than zero) amount of deflection. In accordance with this objective, in some embodiments, the struts  212   a - 212   d  are configured to deflect in accordance with a spring constant of less than or equal to 200,000 Newtons per Meter. 
   Likewise, in accordance with the same objective, in some embodiments, the struts  212   a - 212   d  configured to deflect at least 20 percent relative to a range of deflection between the strut  212   a - 212   d  at rest (undeflected except for miniscule deflection required to support a disc drive) and at maximum permitted deflection without making physical contact with a wall of the encloaure. 
   With respect to  FIG. 2B , the deflection of the strut  212   a - 212   d  at rest, is a miniscule deflection (less than 0.1 mm) of the strut when supporting a 140 gram disc drive  120 . The maximum permitted deflection of the strut  212   a - 212   d  is approximately 8.5 mm. Hence, a 20 percent deflection within the above described range would equal approximately (0.2)(8.5 mm)=1.7 mm. 
   In accordance with the invention, a substantially rigid strut  212   a - 212   b  is not intended to include a substantially flexible strut, such as a strut made from elastomeric material. In some embodiments, the struts  212   a - 212   d  are configured to deflect in accordance with a spring constant of greater than or equal to 100,000 Newtons per Meter. 
     FIG. 3  illustrates an exploded view of a removable disc drive cartridge enclosure including an elastomeric outer rear mounting and shock absorbing component  340 . The outer rear mounting and shock absorbing component  340 , also referred to as a rear mount  340 , is made of an elastomeric material. An elastomeric material is a material that has properties of rubber and that generally provides less rigid support than ABS or other plastics or metals, for example. In accordance with the invention, an elastomeric material is not employed for manufacturing the front struts  212   a - 212   b.    
   As shown, the rear mount  340  is shaped and sized to surround and enclose the rear side  122   d  of the disc drive  120 . Preferably, the rear mount  340  is shaped and sized to form a friction fit over the rear side  122   d  of the disc drive  120 . 
   As shown, the rear mount  340  is configured to provide substantially less rigid support for the rear side  122   d  of the disc drive  120  than the rigid support provided for the front side  122   a  of the disc drive  120  by the front struts  122   a - 122   b , as previously described. As a result, the rear mount  340  can permit the rear side  122   d  of the disc drive  120  to deflect a farther distance in response to a force applied to the cartridge  100  than any deflection permitted for the front side of the disc drive  120  by the front struts  122   a - 122   b.    
   Preferably, the no portion of the disc drive  120 , including its rear side  122   d , should be permitted to deflect so far as to make physical contact in any of the X, Y or Z axis directions, with a wall of the enclosure  150 , as a result of forces applied to the enclosure  150  that are within a pre-determined range of force (shock) applied to the cartridge  100 . 
     FIG. 4  illustrates an exploded view of a removable disc drive cartridge enclosure  150  including a rear mounting and shock absorbing component  440   a - 440   b , also referred to as a rear mount  440   a - 440   b , that is over molded around a rear side of the bottom portion  110  and the top portion  130  of the enclosure  150 . Like the rear mount  340  of  FIG. 3 , this embodiment of the rear mount  440   a - 440   b  is made of an elastomeric material and is configured to provide substantially less rigid support for the rear side  122   d  of the disc drive  120  than the rigid support provided for the front side  122   a  of the disc drive  120  by the front struts  122   a - 122   b , as previously described. 
   As a result, the rear mount  440   a - 440   b  can permit the rear side  122   d  of the disc drive  120  to deflect a farther distance in response to a force applied to the cartridge  100  than any deflection permitted for the front side of the disc drive  120  by the front struts  122   a - 122   b.  In effect, in accordance with the embodiments of  FIGS. 3-4 , the disc drive  120  deflects in hinge like fashion when dropped onto a rigid floor as previously described where the front struts  122 - a - 122   b  can appear to act like a hinge while the rear side  122   d  acts like a plane, such as a door, tilting (rotating) around from a hinge over a small angle of rotation. 
     FIG. 5  illustrates a close up view of holes located along the left side and the right side of the disc drive  120  that are configured to engage snap hooks. The snap hooks (not shown) can be attached to the top portion  130  or the bottom portion  110  of the enclosure  150 . In this embodiment, the snap hooks enable snap together assembly between the disc drive and the upper portion, or between the disc drive and the lower portion or between the upper portion and the lower portion, or any combination thereof. 
     FIG. 5B  illustrates a close up view of hooks  552   a - 552   d  that protrude from the top portion  130  of the enclosure  150  and that are configured to snap assemble and engage the holes  550   a - 550   d  of  FIG. 5A . In other embodiments, the hooks are configured to engage holes (not shown) manufactured as part of the bottom portion  110  of the enclosure  150   
   While the present invention has been particularly shown and described with reference to the preferred mode as illustrated in the drawing, it will be understood by one skilled in the art that various changes in detail may be effected therein without departing from the spirit and scope of the invention as defined by the claims.