Abstract:
A container for disks has an improved latching mechanism. The container comprises a cassette with sidewalls with slots for holding disks in an axial arrangement, two opposite end walls each have a U-shaped recess extending downwardly from the open top, a top cover with a rectangular top portion and two end portions extend downwardly to cover the U-shaped recess. The top cover latches to the cassette by way of a latching mechanism which includes a living hinge, an extension portion, and a hook portion all on each end portion. The hook portion cooperates and engages with a cooperative catch member on the cassette. The extension member is under tension to secure the top cover in place. In an alternate embodiment, recesses on the extension portion connect to nubs on the cassettes or on the bottom cover to secure the top cover in place.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Priority is claimed from U.S. Provisional Patent Application Ser. Nos. 60/377,876 filed May 3, 2002 and 60/403,819 filed Aug. 14, 2002, which are incorporated by reference herein in their entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to containers for storing and transporting memory storage disks, such as magnetic and optical disks. More particularly it relates to such a container with an improved latching mechanism and one with a more robust design. 
     BACKGROUND OF THE INVENTION 
     Storage disks are utilized in the computer industry, as well as other ever-expanding applications, for storage of information. Storage disks may be made of metal or glass and are subjected to a number of processing steps. Such storage disks must be transported, not only within the place of manufacturing during processing, but from the processing and manufacturing facilities to the manufacturing facility where the disks are placed in end use devices, such as disk drives. The disks are typically transported in plastic containers adapted for providing a generally sealed enclosure along with protection of the disks. It is critical for the disks that the enclosure be very clean and preclude entry of particles or other containments. Particles or other containments in the containers can adhere to the disks causing damage or necessitating additional cleaning steps. 
     Containers for storage disks have become generally standardized in their configuration as shown in Prior Art  FIGS. 1–8 . Such disk storage containers have three principal parts, a main body or cassette  20 , a top cover  22  and a bottom cover  24 . These component parts are generally molded from thermoplastic materials such as polycarbonate, polypropylene and the like. 
     The cassette is generally boxed shaped with an open top  26 , an open bottom  28 , a plurality of slots  30  typically formed by inwardly projecting ribs  32  disposed on the side walls  34  hold the disks in an axial arrangement. U-shaped openings or recesses  36  extend downwardly from the top edge  38  into the end walls  40  allow axial access to the disk apertures. The top covers generally have rectangular top portion  42  and two end portions  44  which extend downwardly from the top portion. The end portions close the openings  36  in the end walls  40 . 
     Different means have been utilized to latch the top cover  22  to the cassette  20 . One such latching means is shown in the Prior Art  FIGS. 1 and 2  and is disclosed in U.S. Pat. No. 4,557,382. This embodiment utilizes end portions  44  that extend slightly inward to create an interference fit with the cassette. The end portions  44  must be flexed or deformed outwardly for the top cover  22  to be lowered and close the cassette. The top cover is then held in place by the inward bias or spring action of the end portions  44  and also by a frictional engagement between the catch edge  48  of the end portion  44  and a complementary locking catch  50  on the end wall  40  of the cassette  20 . One potential disadvantage of the top cover latching mechanism of  FIGS. 1 and 2  is that the inward bias of ends  44  can diminish or lessen outwardly over time such that the spring action or inward bias is reduced or, perhaps, lost. Additionally, some level of finesse is required to lower the top cover onto the cassette without making scrapping contact between the end portions  44  and any disks in the cassette or with the locking catch  50  of the end walls, which contact can generate contaminants. Additionally, there have been concerns that the engagement between catch edge  48 , lip  49  and the locking catch  50  does not create a secure latch or an adequate seal, particularly around the entire length of the opening  36  in the end wall. 
     A second Prior Art reference is illustrated in  FIGS. 3 ,  4 , and  5  and is described in more detail in U.S. Pat. No. 5,253,755. This embodiment shows a disk container with a top cover  22  having an end portion  44  with a structural offset portion  54  shaped to snugly nest within the curvature of opening  36  formed by lip  56  of the U-shaped recess  36 . This structural offset forms a seal with respect to the opening  36 . In this Prior Art disk container, the top cover  22  is lowered down to the cassette and snaps into the engagement position as shown in  FIG. 5 . The ramped surface  58  engages the edge  56  of the opening as it is being lowered down and continued downward pressure on the top portion of the top cover urges the engagement member  60  outwardly to clear the edge  56  as shown in  FIG. 5 . Although this particular latching arrangement and top cover configuration has generally been accepted by the industry, concerns have been raised that such a snap-in top cover operates to launch particles from the top cover and cassette during the snap action. Said particles would thus be airborne and may end up as containments on the magnetic disks. Therefore it is desirable to have a latching mechanism that is not subject to the creep and sealing problems associated with the embodiment in  FIGS. 1 and 2  and that also does not utilize the snap action of either of these embodiments. 
     A third Prior Art reference, U.S. Pat. No. 6,070,730, attempted to address the foregoing problems. This design is shown in  FIGS. 6 ,  7  and  8 . In this structure, like that disclosed in  FIGS. 3–5 , the top cover  22  includes end portions  44  having a structural offset portion  54  that rests within the opening  36  of the end wall of the cassette. However, the end portion  44  of the top cover  22  further includes an integral extension  62 , disposed below the offset portion, and connected to the end portion by a hinge element  64 . The locking members comprise a ramped surface  58  and engagement ledge  60  formed on the inside of the integral extension  62 . The engagement ledge  60  is secured by opposed locking ledge  66  formed on the end wall  44  of the cassette  20 . In this manner, the locking members  60  and  66  are physically separated from the structure  54  that closes the U-shaped opening  36 . Also, there is no spring action or inward bias of the end portion  44  that causes particles to be projected into the container. Rather, the extension  62  must be affirmatively pressed inwardly to create engagement between engagement ledge  60  and locking ledge  66 . Ramp  58  provides assistance if the cover is not squarely seated on the cassette. However, such affirmative action on the part of the operator is one draw back of the design. It is possible that the operator may not cause the integral extension  62  to fully engage the locking members, thereby creating the possibility that the cover would not be secure or could be unintentionally removed from the cassette leading to contamination of the contents. In addition, with repeated use, the hinge may weaken and tear or the locking members  60  and  66  may wear away, thereby diminishing their locking ability. This would render the container unuseable. 
     SUMMARY OF THE INVENTION 
     The present invention relates to an improved latching mechanism for use with a container for storing and transporting memory disks. The container comprises a base unit or cassette with sidewalls having inwardly facing ribs or slots within the sidewalls for holding disks in an axial alignment, two opposite end walls each having a U-shaped recess extending downwardly from the open top, a top cover with a top portion and two end portions extending downwardly to close and seal the open top of the cassette and the U-shaped recess, and a bottom cover to close and seal the open bottom of the cassette. The end portions of the top cover include a structural offset that extends into the U-shaped recess to assist in closing and sealing the opening. A U-shaped locking member surrounds each end portion outside the periphery of the end portion and includes a latching mechanism to secure the top cover to complementary latching members disposed on the cassette. In the preferred embodiment, the U-shaped locking member is integrally formed with the top portion of the top cover and has limited flexibility allowing it to distort slightly as part of the locking process. In the same preferred embodiment, the latching mechanisms comprise a pair of cams disposed on the U-shaped locking member, on opposite sides of the end portion, together with a pair of opposed cams disposed on the end wall of the cassette which interact to secure the cover to the cassette. 
     In an alternative embodiment, the U-shaped locking member may be joined to the top portion of the top cover by a hinge, allowing the U-shaped locking member to pivot outwardly and inwardly relative to the end wall of the cassette. The latching mechanisms may remain the same opposed camming surfaces with interlocking surfaces, or may comprise alternatives, such as a hook portion positioned on each end wall of the cassette and a complementary hook receiving portion on the U-shaped locking member (or vice versa). It may also comprise a post and aperture arrangement, a fictional engagement between the U-shaped locking member and the cassette end wall, a pair of complementary interlocking ridges or lips or other structures known to those of skill in the art. In any case, the locking member secures the top cover in place on the cassette under appropriate tension to adequately seal the opening. Additionally, the cassette may include a shoulder disposed near the hinge of the U-shaped locking member and the U-shaped locking member may include a cut-out portion which engages the shoulder on the cassette to assist in securing the top cover to the cassette. In this configuration, the shoulder lock will hold the top cover to the cassette, allowing a separate latching mechanism to secure the U-shaped locking member to the cassette. 
     An advantage and feature of the various embodiments of the present invention is that the top cover is sealed and latched to the cassette without a snap action that can generate and launch particles onto the contents of the cassette, while not requiring any affirmative locking action by the user other than pressing the cover onto the cassette. In addition, due to the mechanical advantage caused by the placement of the latch engagements, the top cover can be more easily unlatched than snap-on top covers or other conventional covers. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an exploded perspective view of a prior art disk shipper. 
         FIG. 2  is a cross-sectional view of the latching mechanism of the prior art shipper of  FIG. 1 . 
         FIG. 3  is an elevational view of the component parts of a second prior art disk shipper. 
         FIG. 4  is an elevational view of a portion of the prior art disk shipper of  FIG. 3 . 
         FIG. 5  is a cross-sectional view of the latching mechanism of the prior art shipper of  FIGS. 3 and 4 . 
         FIG. 6  is an elevational view of a third prior art shipper. 
         FIG. 7  is a perspective view of the top cover of the prior art shipper of  FIG. 6 . 
         FIG. 8  is an elevational view of the end portion of the prior art top cover illustrated in  FIG. 7 . 
         FIG. 9  is an exploded perspective view of a first embodiment of the disk shipper of the present invention. 
         FIG. 10  is a side elevation view of the disk shipper illustrated in  FIG. 9 . 
         FIG. 11  is a top plan view of the base of the disk shipper illustrated in  FIG. 9 . 
         FIG. 12  is a cross-sectional side view of the base of the disk shipper illustrated in  FIG. 9 , taken along line  12 — 12  of  FIG. 11 . 
         FIG. 13  is an end elevation view of the base of the disk shipper illustrated in  FIG. 9 . 
         FIG. 14  is a cross-sectional end view of the base of the disk shipper illustrated in  FIG. 9 , taken along line  14 — 14  in  FIG. 11 . 
         FIG. 15  is a cross-sectional end view of the base of the disk shipper illustrated in  FIG. 9 , taken along line  15 — 15  in  FIG. 11 . 
         FIG. 16  is an enlarged end view of a portion of the latching mechanism of the disk shipper illustrated in  FIG. 13 . 
         FIG. 17  is an enlarged side elevation view of a portion of the latching mechanism of the disk shipper illustrated in  FIG. 16 . 
         FIG. 18  is a perspective view of the cover of the disk shipper illustrated in  FIG. 9 . 
         FIG. 19  is a perspective view of the cover of the disk shipper illustrated in  FIG. 9 , but upside down compared to  FIG. 18 . 
         FIG. 20  is a side plan view of the cover of the disk shipper illustrated in  FIG. 9 . 
         FIG. 21  is an end plan view of the cover of the disk shipper illustrated in  FIG. 9 . 
         FIG. 22  is a cross-sectional end view of the cover of the disk shipper illustrated in  FIG. 9 , taken along line  22 — 22  of  FIG. 20 . 
         FIG. 23A  is a partial side view of the latching mechanism of the disk shipper illustrated in  FIG. 9 , depicting the cover moving downward relative to the base and prior to latching. 
         FIG. 23B  is a partial side view of the latching mechanism of the disk shipper illustrated in  FIG. 9 , depicting the cover seated on the base prior to latching. 
         FIG. 23C  is a partial side view of the latching mechanism of the disk shipper illustrated in  FIG. 9 , depicting the cover flexing to accommodate interaction of the latching mechanism prior to latching. 
         FIG. 23D  is a partial side view of the latching mechanism of the disk shipper illustrated in  FIG. 9 , depicting the cover flexing to accomplish latching. 
         FIG. 23E  is a partial side view of the latching mechanism of the disk shipper illustrated in  FIG. 9 , depicting the cover latched to the base. 
         FIG. 24  is an exploded perspective view of an alternative embodiment of the present invention. 
         FIG. 25  is an enlarged view of a portion of the latching mechanism of the disk shipper illustrated in  FIG. 24 . 
         FIG. 26  is a perspective view of the alternative embodiment of the disk shipper of  FIG. 24 , shown with the cover partially engaging the base. 
         FIG. 27  is an enlarged view of a portion of the latching mechanism of the disk shipper illustrated in  FIG. 26 . 
         FIG. 28  is a perspective view of the disk shipper of  FIG. 24 , showing the latching mechanism in a partially-open position. 
         FIG. 29  is a top plan view of the disk shipper of  FIG. 24 , with one latching mechanism open. 
         FIG. 30  is a cross-sectional side view of the base and top cover of the disk shipper illustrated in  FIG. 29  taken along line  30 — 30  of  FIG. 29 . 
         FIG. 31  is an enlarged view of a portion of the latching mechanism of the disk shipper illustrated in  FIG. 30 , showing the latching mechanism in an engaged position. 
         FIG. 32  is a side plan view of an alternative embodiment of the cover of the disk shipper illustrated in  FIG. 9 . 
         FIG. 33  is an end plan view of the cover of the disk shipper illustrated in  FIG. 32 . 
         FIG. 34  is a cross-sectional end view of the cover of the disk shipper illustrated in  FIG. 32 , taken along line  34 — 34  of  FIG. 32 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring first to  FIG. 9 , a first embodiment of the invention is shown in the context of a shipping and storage container for memory disks generally designated with the numeral  100 . When used alone herein, “disk” should be considered as any type of memory disk, including both magnetic and optical memory disks. In general terms and with reference to the drawings, the disk shipper is comprised of three pieces: a base or cassette  110  having an open top, open bottom and open ends; a bottom cover  112  for enclosing the open bottom of the cassette and, a top cover  114  for enclosing the open top and open ends of the cassette. The cassette, as illustrated in more detail in  FIGS. 10–17 , has two end walls  116  and two parallel side walls  118  extending between the end walls. Slots  120  are formed in the side walls of the cassette by inwardly extending teeth or ribs  122 . The slots are configured to hold magnetic disks in parallel axial alignment by engaging the outer edge portions of the disks. The side walls  118  are uniform in thickness throughout the curved portion  118   a  and the upper vertical portion  118   b . As best seen in  FIG. 15 , the ribs  122  are uniform in height relative to the inside surface of the side wall. As best seen in  FIG. 12 , the upper portion of the ribs  122   a  extend to the top  36  of the side wall  118  and are tapered in width to enlarge the gap between adjacent ribs to facilitate receiving and removing disks. There are no exterior ribs or strengthening members on the outside surface of the side walls. 
     The end walls  116  include a U-shaped opening  124  extending downwardly from the top edge of the cassette. (See  FIGS. 13–15 .) A saddle  126  is formed along the edge of the U-shaped opening and has a surface  128  that is perpendicular to the plane of the opening (see  FIG. 11 ). The internal surface  130  of the end wall is vertical, however, the outer edge or surface of the saddle  126   a  extends a further distance at the bottom of the opening compared to the top, defining a plane P that lies at an angle relative to the vertical end wall  130  ( FIGS. 10 ,  12 ,  17  and  23 B). An outer, buffer wall  132  is positioned outwardly from the top edge  136  of the open base along the side walls  118  and defines a channel  134  between itself and the upper edge  136  of the side wall of the cassette (see  FIGS. 9 ,  11 ,  14  and  15 ). This outer wall or buffer creates a shield to protect the perimeter edge  138  of the top cover from impact by positioning the perimeter edge of the cover within the channel  134 . Each of the ends of the outer wall are thickened, such as at  132   a , to create further rigidity and protection from impacts against the end walls and corners of the shipper that occur during use. A pair of wedge-shaped locking cams  140  are positioned on each end wall  116  laterally outside of the U-shaped opening  124  and form part of the locking mechanism for securing the top cover  114  to the cassette  110 . The locking cams  140  include a camming surface  162  and a locking surface  164 . The bottom cover  112  is held on the opened bottom of the cassette by a friction fit with the side walls  118  and end walls  116  of the cassette  110  and side walls  170  and end walls  172  of bottom cover  112 . 
     As illustrated in  FIGS. 18–22 , the top cover  114  includes a generally rectangular portion  142  with integral downwardly extending end portions  144 . A perimeter edge  138 , extending between the end portions  144  and downwardly from the rectangular portion  142 , is formed at the outer perimeter of the rectangular portion. This edge or lip  138  fits within the channel  134  formed along the upper edge  136  of the side walls  118  of the cassette and is protected from impact by the outer wall or buffer  132  of the cassette. The rectangular portion further includes two recesses  146  which extend parallel to each other adjacent the outer edge of the rectangular portion and are spaced by a central planar portion  148 . A row of inwardly projecting ribs or teeth  150  extend along the inner surface of each recessed portion and are aligned with ribs  122  formed in the side walls of the cassette to further secure the magnetic disks within the shipper. A flexible skirt  152  disposed along the length of the lower surface of each recessed portion  146  and outwardly of the teeth  150  engages the perimeter edges of the memory disks to dampen movement of the disks within the shipper. 
     The end portions  144  of the top cover include a U-shaped structural offset or seal member  154  designed to nest against surface  128  within the U-shaped opening  124  of the cassette and generally seal the opening. An outer flange  156  of each end portion, best seen in FIGS.  18  and  23 A–C, is contoured to abut against the non-vertical outer edge  126   a  of the saddle  126  along the plane P. The non-vertical profile of edge  126   a  promotes sealing of the opening by gradually forcing flanges  156  outwardly. Given the molded construction of the top cover, this creates an inward force by the end portion  144  against the cassette end wall which keeps flange  156  fully engaged against surface  126   a.    
     Each end portion further includes a separate locking member or yoke  158  which is spaced outwardly from the end portion  144 . A pair of complementary wedges  160  are located on the yoke member to engage and cooperate with the wedges  140  disposed on the end walls of the cassette. Thus, and with reference to  FIGS. 23A–C , as the cover is moved downwardly to nest on the cassette, the camming surfaces  162  of the complementary wedges  140 ,  160  engage each other to force the locking member  158  outwardly from the base unit until the camming surfaces pass each other, allowing the locking member  158  to snap inwardly and the locking surfaces  164  to engage to thereby secure the cover to the base. The locking occurs outwardly of the opening  124  and without movement of U-shaped offset portion  154  allowing the U-shaped offset portion to maintain its seal of opening  124 . A pair of handles  166  may be included on each end portion to assist in handling the top cover  114  during locking and in handling the entire container when the cover is latched to the base. It should be appreciated that the locking member  158  is separate from the end portion  144 . Although not shown in the figures, it should also be appreciated that the locking member  158  may alternatively comprise two independent separate arms which are not connected. The bridge portion  176  interconnecting the two arms does facilitate latching and unlatching the cover to the base by allowing the pair of wedges  160  to be operated simultaneously. 
     With this locking mechanism, the locking features of the disk shippers are separated from the sealing features to prevent dust and other particles from contaminating the memory disks stored at each end of the base unit as the cover is engaged with the base portion. In other words, the U-shaped offset portions  154  which seal the open U-shaped end  124  of the base do not snap into position or otherwise cause particles to be projected into the interior of the base unit during the securement of the top cover to the base unit. Moreover, because the locking member  158  is spaced outwardly and separate from the U-shaped offset portions  154 , the U-shaped open end  124  is sufficiently sealed by offset portion  154  such that the snap action of locking member  158  does not contaminate the interior of the shipper. Moreover, the locking will occur almost automatically by simply pressing the cover onto the base; no separate or affirmation locking step is needed. Thus, closing and securing the cover  114  to the cassette  110  can be accomplished in a single, one-dimensional movement between the cover and cassette. In addition, because the locking member  158  is separate from the U-shaped offset  154 , the regular flexing of the locking member  158  will not diminish the inward bias of the U-shaped offset portion  154 , thereby maintaining a sealed closure over a longer product life span. 
     A second embodiment of the present invention is shown in  FIGS. 24–31 . In this embodiment, the base or cassette  202  and the top cover  204  remain generally the same. However, the latching mechanism is different. Turning to the cassette  202 , and more particularly, the end walls  206 , a pair of cutout portions  208  and  210  are formed on the underneath surface of the lower portion of the saddle  212  to create a ridge or lip  214  (see  FIG. 25 ). The lip  214  cooperates with a locking member associated with the top cover to secure the cover to the cassette. 
     As shown in  FIGS. 24 ,  26 ,  27  and  29 , the top cover  204  includes a locking member  216  pivotally attached to the top cover  204  by a hinge  218 . The hinge  218  permits the locking member  216  to pivot relative to the top cover while, simultaneously, the U-shaped structural offset  220  is sealably nested within the saddle  212  when the top cover  204  is properly seated on the cassette  202 . This allows the locking member  216  to pivot upwardly and downwardly about the end of the rectangular portion of the top cover, while the U-shaped offset  220  remains stationary. As best seen in  FIG. 31 , the locking member  216  further includes a raised portion  222  that includes a lip  224  at its inner edge. The lip  224  engages the lip  214  of the base portion when the locking member  216  member is pressed against the end wall  206  of the base  202  to secure the U-shaped locking member  216  to the base  202 . To accommodate the raised lip  224  on the locking member  216 , the lower portion of the U-shaped offset  220  must also be modified. As seen in  FIG. 28 , unlike in the preferred embodiment, the flange  226  positioned at the perimeter of the U-shaped offset  220  is not continuous. Instead, at the lower curve of the U-shaped offset  220 , the flange  226  terminates and a raised portion  228  is formed to provide clearance for the raised lip  224  as it moves between a latched and unlatched position. 
     As shown in  FIG. 26 , the U-shaped locking member  216  further includes cutouts  230  which allow the U-shaped member  216  to accommodate the structural ribs  232  formed along end wall  206  of the base  204 . Similarly, notches or cutouts  234  are also formed in the U-shaped locking member  216 , proximate the hinges  218 , to accommodate other ribs or strengthening members  236  formed in the end wall  206  of the base  202 . As should be appreciated, the cutouts can vary in location and size to accommodate unique structural features in the cassette body, while still permitting the locking member  216  to fully engage the complementary locking elements of the cassette. 
     The present invention may be embodied in other specific forms without departing from the spirit or essential attributes thereof, and it is therefore desired that the present embodiment be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention. For example, the mechanism by which the independent locking member attaches to the cassette can vary to include other locking mechanisms positioned at other points along the independent locking member of the top cover to vary and/or optimize the mechanical advantage provided by the locking member. This may include a post  140  and aperture  260  arrangement as shown, for example, by the cassette of  FIGS. 13 ,  16  and  17  and the cover of  FIGS. 32–34 . Other alternatives, within the scope of the present invention, will likely occur to those of ordinary skill in the art upon review of the specification and appended claims.