Abstract:
Network cables are provided via spool cartridges remove ably held inside snap-in cassettes that again are slideably inserted and snap arrested in a rack mountable chassis. The network cables are spring loaded spooled such that they autonomously retract upon unplugging and such that they are straightened while plugged in. Each snap-in cassette has a rear connector that is snap connected to the spooled network cable via an externally releasable connector pair inside the snap-in cassette. The network cables are spooled around a continuously rotating contact hub configured for high frequency signal transfer. The rear connectors reach through the chassis for a centralized network connection. The chassis is dimensioned in conjunction with well known computer rack standards for simple integration into server station architectures. The dual level modularity of spool cartridges inside the snap-in cassette inside the chassis provides for maximum system flexibility and maximum network connections.

Description:
FIELD OF INVENTION 
     The present invention relates to systems for providing multiple cables to a number of rack mounted computers. In particular, the present invention relates to a rack mountable unit that modularly provides multiple retractable network connection cables. 
     BACKGROUND OF INVENTION 
     In a conventional server station, multiple computers and other server station components are commonly assembled in standardized racks. Several racks may be placed next to each other to accommodate for eventual large numbers of such server station devices. Individual server station devices need to be fast and easily connected and disconnected from the server station to reduce overall maintenance of the server station. Due to ever increasing number and complexity of server station components and the affiliated network wiring, the task of connecting, reconnecting and/or sorting out the network cables may become excessively time consuming. Therefore, there exists a need for a simple, modular network cable connection system that is easily scaled and adjusted. The present invention addresses this need. 
     Sorting and untangling of multiple network cables that are connecting rack mounted server station components with a hub may be particularly cumbersome in cases of loosely hanging network cables. Therefore there exists a need for a network cable connection system that provides straightened network cable connections and a spooling of excess cables. The present invention addresses also this need. 
     Server station components may vary with their network connectors. Therefore there exists a need for a network cable connection system that may be modularly adjusted in an ergonomic fashion to varying network connector standards. The present invention addresses also this need. 
     Server station architectures commonly incorporate generic  19 ″ racks and server station components are also commonly dimensioned to that standard. For a most efficient use of rack space for server station components it is desirable to have a rack integrated network cable connection system that provides a maximum number of individually dispensable network cables within a minimum rack face area. The present invention addresses also this need. 
     In the prior art, spooling of hundred-plus MHz transmitting data cables is commonly accomplished by double cable spooling whereby a required employment of a continuous rotating contact hub is circumvented. Single cable spooling to the contrary is a prerequisite for integrating a cable spool in a larger assembly by providing a stationary spool connector that electrically connects to an extendable connector via a spooled cable and a continuously rotating contact hub. Therefore, there exists a need for a hundred-plus MHz transmitting continuously rotating contact hub. The present invention addresses this need. 
     SUMMARY 
     A rack unit includes preferably at least twenty four snap-in cassettes slide ably fitting through a main access opening of a chassis preferably fitting in a  19 ″ computer rack. Each snap-in cassette houses preferably two spool cartridges behind each other amounting to preferably at least forty eight spooled network cables. The snap-in cassettes may be snap arrested inside the chassis via a latching feature such that preferably two rear connectors of the assembled cartridges are peripherally accessible at the rear side of the chassis. 
     The rear connectors are conductively connected via a contact drum axle and a spooled cable to an extendable front connector that is configured to connect to the server station component. The spooled cables are retractably spooled around the contact axle preferably in a spring loaded fashion such that the spooled cable remains straightened after connecting the front connector to the respective network connector. In case a network cable needs to be disconnected, the front connector only needs to be unplugged and the cable is spooled into its respective spool cartridge that again is contained inside the snap-in cassette. 
     Individual spool cartridges may be conveniently replaced inside a snap-in cassette while that respective snap-in cassette is released at the backside of the chassis and pulled out of its respective chassis slot. The same snap-in feature that locks the snap-in cassette in its assembly position may serve as a hinge hook at the front to the chassis such that the snap-in cassette may loosely hang down from the bottom edge of the chassi&#39;s frontal access opening. The loosely hanging snap-in cassette remains sufficiently stabilized with its top side accessible for inserting and/or removing individual spool cartridges. The spool cartridges of a number of adjacent snap-in cassettes may be simultaneously accessed via the top access. This top access in combination with the hinging access positioning of the snap-in cassettes, the spring loaded self spooling of the cables and the dual level modularity of the spool cartridges inside the snap-in cassettes inside the chassis provide for fastest and most easy configuration of the rack unit as may be well appreciated by anyone skilled in the art. 
     The single cable spooling inside the spool cartridges is accomplished by a specially configured sliding contact spool hub that keeps noise and cross talk at sufficiently low levels such that signal frequencies of significantly above 100 MHz may be reliably transmitted across the spool hub in conjunction with well known CAT5 and eventually CAT6 performance criteria. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a first perspective view of the rack unit with all but one snap-in cassettes assembled and one snap-in cassette hinging at the bottom edge of the frontal access opening. 
         FIG. 2A  is a second perspective view of rack unit of  FIG. 1 . Side housing portions of the one hinging snap-in cassette and of its inserted spool cartridges are removed for visibility of the spooled cables. 
         FIG. 2B  is a detail view of a detail  2 B indicated in  FIG. 2A . 
         FIG. 2C  is a detail view of a detail  2 C indicated in  FIG. 2A . 
         FIG. 3  is the first perspective view of the chassis of  FIG. 1 . 
         FIG. 4  is the first perspective view of the hinging snap-in cassette of  FIG. 1 . 
         FIG. 5  is a third perspective view of a snap-in cassette with a side housing portion of that snap-in cassette being removed. 
         FIG. 6  is a side view of a spool cartridge with a side housing portion of that spool cartridge being removed. 
         FIG. 7  is a side view of the spool cartridge of  FIG. 6  with a coil spring and a spool drum of that spool cartridge being removed. 
       FIG. AA is a cross sectional view of the spool cartridge of  FIG. 6  cut along a section line A-A indicated in  FIG. 6 . 
         FIG. 8  is a fourth perspective view of a cable spool hub and slider detail. 
         FIG. 9  is the fourth perspective in scale view of slider and hub contacts of  FIG. 9 . 
     
    
    
     DETAILED DESCRIPTION 
     Referring to  FIGS. 1-3 , a multiple retractable cable dispensing rack unit  1  in accordance with a preferred embodiment of the invention includes a chassis  20 , at least one but preferably at least twenty four snap-in cassettes  30 . The chassis  20  has two side walls  25 , a top cover  22 , a bottom cover  23 , a rear side  24  with a rear access perforation  241  and a front side  21  with a main access opening  211  preferably occupying substantially the entire front side  21 . In at least one of the top and the bottom cover  22 ,  23  but preferably in the bottom cover  23  are a snap-in perforation  231  and a trap perforation  232 . The snap-in perforation  231  is preferably adjacent the rear side  24  and the trap perforation  232  is preferably adjacent the front side  21 . 
     The snap-in cassettes  30  slideably fit substantially through the main access opening  211  and in between the front side  21  and the rear side  24  and in between the top cover  22  and the bottom cover  23 . In addition, the chassis  20  may feature cassette rails  233  for a lateral positioning and guiding of the snap-in cassettes  30 . In that way, the snap-in cassettes  30  may be laterally and independently slideably inserted via the main access opening  211  and interchangeable fixed in the chassis  20 . Preferably each snap-in cassette  30  features rear connectors  32  in a number equal the number of spool cartridges  36  contained inside the respective snap-in cassette  30 . The rear connectors  32  are extending through and peripherally accessible at the rear access perforation  24  while the respective snap-in cassette  30  is snap-in arrested as said. The rear connectors  32  may be directly conductively connected to an adjacent oppositely positioned internal spool connector  35 . In case the internal cassette connector  35  is in a distance, an intermediate extension cable  351  with extension connector  352  may connect to an internal mating connector  354  of the rear connector  32 . Internal mating connector and internal spool connector  35  may be identically configured for ease of fabrication. 
     Further referring to  FIG. 4-AA , preferably each snap-in cassette  30  features also an extendable front connector  33  that is conductively through connected with a respective rear connector  32  at least via a spooled cable  34  and a contact hub  361  but preferably also via external cassette connector  363 , internal spool connector  35  and eventually via extension cable  351 , extension connector  352  and internal mating connector  354 . The spooled cable  34  is preferably autonomously retracting and spooled around the contact hub  361 . The autonomous retraction of the spooled cable  34  may be provided by a retracting spring  365  configured as a well known coil spring  365 . The coil spring  365  may exert a spring loaded torque onto a cable drum  364  while withholding itself in a torque transfer slot  3614  of the contact hub  361  that is rigidly connected with a spool housing  362 . The spooled cable  34  is spooled on the cable drum  364 . 
     The snap-in cassette  30  has also a latching feature  31  configured in conjunction with at least the snap-in perforation  231  but preferably also in conjunction with the trap perforation  232 . In that way, the latching feature  31  may be peripherally accessed and manually actuated via a manual actuator  311  while the latching feature  31  is engaged in the snap-in perforation  231  and while the respective snap-in cassette  30  is snap arrested as said. 
     The latching feature  31  may also be configured in conjunction with the trap perforation  232  that is positioned adjacent the main access opening  211  and at the same one of the top cover  22  and the bottom cover  23  as the snap-in perforation  231  such that the respective snap-in cassette  30  is pivotably arrested immediately prior to being fully slideably removed from the chassis  20  as shown in  FIGS. 1 ,  2 A. The latching feature  31  has a manual actuator  311  that is peripherally accessible at the rear side  24  while the snap-in cassette  30  is snapped in and fixed. 
     The chassis  20  may feature rack flanges  251  with rack screw holes  2512  via which the multiple retractable cable dispensing rack unit  1  may be fixed in a standard  19 ″ computer rack as is well known in the art. To fit into such  19 ″ computer rack, the chassis  20  may have a rack width  20 W of up to about 16.8 inches and a rack depth  20 D of up to about 10 inches. To occupy minimal rack height, the chassis  20  may have a rack height  20 H of not more than 3.5 inches. Within that spatial envelope of the chassis  20  are up to twenty four snap-in cassettes  30  snap arrested and interchangeable fixed. Preferably each snap-in cassette  30  may have at least two spool cartridges  36  such that at least two extendable front connectors  33  may be pulled out and extend at least 70 inches at the cassette front  392  via their respective spooled cable  34 . 
     The extendable front connectors  33  are eight fold independently conductively connected with a respective rear connector  32  in accordance with at least a well known CAT5e but preferably a CAT6 performance criteria as specified by ANSI/TIA/EIA-568-B.2-2001. The extendable front connector  33  may be a well known CAT5, or CAT5e, or CAT6 or USB connector. Well known data signals may be transmitted between respective rear connectors  32  and extendable front connectors  33  and across the contact hub  361  with at least 100 MHz. 
     Spooling of the spooled cable  34  may be optimized by providing the spooled cable  34  with a substantially flat cross section such that the spooled cable  34  may easily bend and roll up while being spooled. The substantially flat cross section may have a width to height ratio of preferably at least five. 
     Dual level modularity of the multiple retractable cable dispensing unit  1  is provided by at least one but preferably two spool cartridges  36  that are interchangeable fixed inside a respective one of the snap-in cassettes  30 , which in turn are interchangeable fixed inside the chassis  20 . Interchangeable fixed in the context of the present invention means that the snap-in cassettes  30  and/or the spool cartridges  36  are fixed, removed or replaced in a routinely fashion preferably without use of any tools. 
     Each spool cartridge  36  features a spool housing  362  that encapsulates the contact hub  361  and a cable drum  364  that is rotatable guided by the contact hub  361  for spooling the spooled cable  34 . Also part of each spool cartridge  36  is an external cassette connector  363  in a mating configuration with an internal spool connector  35 , which is positioned inside each snap-in cassette  30  and conductively connected with a respective rear connector  32 . The external cassette connectors  363  are conductively connected to respective extendable front connectors  33  via a respective hub connect cable  366 , contact hub  361  and spooled cable  34 . In that way, the conductive through connection is established between rear connector  32  and extendable front connector  33  while a respective one spool cartridge  36  is interchangeable fixed inside a respective one snap-in cassette  30  and while a respective one external cassette connector  363  is coupled with a respective one internal spool connector  35 . 
     The cassette housing  38  of the snap-in cassette  30  has holding slots  37 F,  37 R, which have a mating configuration with the spool housing  362  for interchangeable fixing the spool cartridge  36  within the cassette housing  38 . The holding slots  37 F,  37 R are further configured in conjunction with the spool housing  362 , the external cassette connector  363  and the internal spool connector  35  such that the external cassette connector  363  connects to the internal spool connector  35  while the spool cartridge  36  is inserted and guided moved into its fixed position at least within the outside boundaries of the snap-in cassette  30  but preferably within the cassette housing  38 . A frontal holding slot  37 F may be directly accessible at the cassette front  392 . A rear holding slot  37 R may be accessible at the cassette top  393 . 
     The external cassette connector  363  and the internal spool connector  35  preferably snap mate. In this case, the snap mating may be remotely decoupled via a snap release actuator  381 . The external cassette connector  363  and the internal spool connector  35  as well as the extension connector  352  and the internal matting connector  354  may be mating CAT5 or CAT5e or CAT6 connectors that are well established in the industry at the time of this invention for high data through put. 
     Common to CAT5, CAT5e and CAT6 connectors is an integrated snapping mechanism including a release lever  3631  for peripherally disconnecting the snapped connection between the two mating connectors as is well known in the art. The snap release actuator  381  may have a contact lip  3812  that is positioned in conjunction with such connector release lever  3631  such that peripheral actuation of the release actuator  381  is transferred via the contact lip  3812  onto the connector release lever  3631  decoupling the mating connection between external cassette connector  363  and internal spool connector  35 . 
     To take advantage of the extended depth of computer racks while occupying a minimum of rack height, the rack depth  20 D is preferably a multiple of the rack height  20 H. Spooling a cable to the contrary requires a substantially circular spacing around the hub axis HA and consequently a substantially equally deep and high spool housing  362 . Therefore, preferably two or more spool cartridges  36  may be interchangeable fixed inside a single snap-in cassette  30  behind each other with respect to a cassette front side  392 . In that case, each of the snap-in cassettes  30  may feature two or more internal spool connector  35 , two or more spool cartridges  36  interchangeable fixed in one frontal holding slot  37 F and one or more rear holding slots  37 R. Extending between each rear holding slot  37 R and the cassette front  392  may be an externally accessible cable channel  382 . The externally accessible cable channel  382  may have a cable channel opening  3812  through the cassette housing  38  at the cassette top  393 . Through the cable channel opening  3812  a spooled cable  34  may be inserted in or removed from the externally accessible cable channel  382  while a spool cartridge  36  is inserted or removed from a rear holding slot  37 R. As a result, two or more of the extendable front connectors  33  are interchangeable accessible at the main access opening  211  and at least respective two rear connectors  32  are accessible at the rear side  24  while the snap-in cassette  30  is interchangeable fixed inside the chassis  20 . For easy access to individual spool cartridges without having to fully remove the snap-in cassette  30  from the chassis  20 , the rear holding slot(s)  37 R behind the frontal holding slot  37 F and the externally accessible cable channel  382  are preferably accessible at a cassette top  393 . The frontal holding slot  37  may be accessible at the cassette front  392 . 
     Referring to  FIGS. 8 and 9 , the preferably continuous rotating contact hub  361  comprises collector wires  3611  that are connected to the external cassette connector  363  via a hub connect cable  366 . A radial portion  3661  of the hub connect cable is kept flat adjacent or embedded in the spool housing  362  in the vicinity of the cable drum  364 . In that way, the radial connect cable portion  3661  contributes to a minimal overall width of the spool cartridge  36  and consequently of the snap-in cartridge  30 , which in turn contributes to a maximum number of snap-in cartridges  30  assembled along the rack width  20 W. 
     The collector wires  3611  may be wrapped in alternately opposite direction around the rotation axis HA of the contact hub  361 , which results in cancellation of high frequency electromagnetic fields eventually occurring in adjacent wrapped collector wires  3611  during electrical signal transmission. Also, the collector wire bends  3612  are free of sharp corners, which results in reduced high frequency electromagnetic corner field emission also eventually occurring during electrical signal transmission. Both alternately opposing wire wrapping and non sharp wire bends  3612  contribute to a high signal transmission capacity of substantially above 100 MHz, which is called hundred-plus MHz in context of the present invention. 
     Due to the non sharp bends  3612  there exists a collector wire gap  3613 . A slider head  341  combined with the cable drum  364  may hold sliders  342  in a number equal the number of collector wires  3611  and in contacting position with respect to the collector wires  3611  while the cable drum  364  rotates around the hub axis HA. The sliders  342  may have a contact extension  343  substantially larger than the collector wire gap  3613  such that snug area contact between respective sliders  342  and collector wires  3611  is warranted at any rotational position of the slider head  341 . 
     After the multiple retractable cable dispensing rack unit  1  is mounted in a computer rack, the extendable front connectors  33  may be pulled out at the respective cassette fronts  392  and connected to computing devices. The retract springs  365  keep the pulled out spooled cable  34  under tension and assure a straight cable connection to the computer. The rear connectors  32  may be connected to a well known central network distribution cable string. A large number of computers may be thereby conveniently connected to a network with clear oversight of which spooled cable  34  connects to which computer. In case a computer needs to be disconnected, the respective extendable front connector  33  just needs to be pulled out and the respective retract spring  364  spools the spooled cable  34  back in. 
     In case a computer needs to be connected with a connector standard not present in the multiple retractable cable dispensing unit  1 , a snap-in cassette  30  may be released from its interchangeable fixed position by manually actuating the manual actuator  311  after disconnecting the respective rear connector(s)  32 . The released snap-in cassette  30  may be moved forward until the latching feature  31  engages with the trap perforation  232 . There, the respective snap-in cassette  30  may be loosely held hanging down the chassis  20 . A spool cartridge  36  may be replaced from the rear holding slot  37  by actuating the snap release actuator  381 . Then a spool cartridge  36  having an extendable front connector  33  in desired configuration may be reinserted. In case an extendable front connector  33  needs to be replaced with a spool cartridge  36  from a front holding slot  37 F, the respective snap-in cartridge  30  may be pulled out only as far as to laterally access the respective snap release actuator  381 . 
     Accordingly, the scope of the invention described in the Figures and the Specification above is set forth by the following Claims and their legal equivalent: