Patent Publication Number: US-10310571-B2

Title: Cable cassette apparatus

Description:
BACKGROUND 
     The present invention relates generally to the field of tools and equipment for use with computer cabinets, and more particularly to apparatus for managing cables that connect to interface cards in computer cabinets. 
     Computer servers and other systems are often installed in cabinets, racks, or other support structures. Such computer systems often require various cables to be connected to ports mounted on or in the computer chassis within the cabinet or other rack. Cable connectors may be incorporated into printed circuit board devices (i.e., “cards”) that interface with larger computer systems. As signal transmission rates for cabling in server environments grow and new performance limitations are reached, Engineers and designers continue to face challenges in managing and extending cable connections. 
     SUMMARY 
     An apparatus includes a cassette. The cassette includes a carriage. The carriage is retained internally to the cassette. The apparatus further includes a booklet assembly. The booklet assembly includes a cable connector. The cable connector is affixed internally to the booklet assembly. The cassette is configured for insertion into the booklet assembly. The apparatus further includes a cable assembly. The cable assembly is configured for insertion into the cable connector. The carriage is configured for retaining the cable assembly. 
     In an aspect, the cassette is inserted into and retained within the booklet assembly, and said cable assembly is inserted into the cable connector and retained in an inserted position by the carriage. In an aspect, the booklet assembly conforms to a form factor, the booklet assembly includes a card, and the card is of reduced length relative to the form factor. The cassette  220  may be understood as filling a length difference between the card  204  and the form factor, which corresponds to the size of the booklet assembly  200 . In an aspect, the cable assembly is a preexisting cable assembly. 
     In an aspect, a method of using the apparatus includes preloading the cable assembly into the carriage, inserting the cassette into the booklet assembly, and configuring the carriage such that the cable assembly is inserted into the cable connector and retained in an inserted position by the carriage. In an aspect of the method of using the apparatus, the booklet assembly is configured for insertion into a device cabinet, the device cabinet houses a computer system, the booklet assembly further includes a backplane connector, the backplane connector is configured to connected to a backplane socket, the backplane socket is in electronic communication with the computer system, and the method further includes inserting the booklet assembly into the device cabinet such that the backplane connector is inserted into the backplane socket. 
     In an aspect, an apparatus includes a cassette. The cassette includes a cassette base. The cassette base includes a cassette base top surface, a cassette base front edge, a cassette base rear edge, a cassette base right edge, and a cassette base left edge. The cassette further includes a cassette front panel, a cassette rear panel, a cassette right panel, and a cassette left panel. The cassette front panel is affixed to the cassette base front edge, orthogonal to the cassette base top surface. The cassette rear panel is affixed to the cassette base rear edge, orthogonal to the cassette base top surface. The cassette right panel is affixed to the cassette base right edge, orthogonal to the cassette base top surface. The cassette left panel is affixed to the cassette base left edge, orthogonal to the cassette base top surface. The cassette front panel includes a front panel gap cut therefrom. The cassette further includes a carriage. The carriage includes a carriage panel. The carriage panel includes a carriage panel top face and a carriage panel bottom face. The carriage further includes at least one hook structure affixed to the carriage panel top face. The carriage is retained to the cassette base such that the cassette base top surface opposes the carriage panel bottom surface. The front panel gap and the carriage are aligned along an insertion dimension. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a plan view of a full length card in the context of schematically represented cabinet and computer system environment, in accordance with at least one embodiment of the invention. 
         FIG. 2  is a plan view of a cable assembly, cassette, and reduced form factor card, in accordance with at least one embodiment of the invention. 
         FIG. 3A  is an elevated right-front perspective view of a cable assembly and cassette, in accordance with at least one embodiment of the invention. 
         FIG. 3B  is an elevated right-front perspective view of a cable assembly and cassette with a light pipe, in accordance with at least one embodiment of the invention. 
         FIG. 4A  is an elevated right-rear perspective view of a cassette, in accordance with at least one embodiment of the invention. 
         FIG. 4B  is an elevated right-rear perspective view of a cassette with carriage in expanded position, in accordance with at least one embodiment of the invention. 
         FIG. 4C  is a lowered, right-rear perspective view of a carriage, in accordance with at least one embodiment of the invention. 
         FIG. 5  is a plan view of a cable assembly, cassette with jack screw carriage retainer, and reduced form factor card, in accordance with at least one embodiment of the invention. 
         FIG. 6A  is an elevated rear perspective view of a cable assembly and cassette with jack screw carriage retainer, in accordance with at least one embodiment of the invention. 
         FIG. 6B  is a close-up, elevated rear-right perspective view of a jack screw, in accordance with at least one embodiment of the invention. 
         FIG. 7  is a plan view of a cable assembly, cassette with fixed carriage, and reduced form factor card, in accordance with at least one embodiment of the invention. 
         FIG. 8  is an elevated right-rear perspective view of a cassette with fixed carriage, in accordance with at least one embodiment of the invention. 
     
    
    
     DETAILED DESCRIPTION 
     Referring now to the invention in more detail,  FIG. 1  is a plan view of a booklet assembly, generally designated  100 , which is configured for insertion into a device cabinet  170 . The device cabinet  170  is schematically represented by a pair of parallel lines. The device cabinet  170  may include rails, guides, slides, slots or other mounting structures suitable for receiving the booklet assembly  100 . In an embodiment, the device cabinet  170  is the back of a rack mounted server installation, as may be found in a computer data center. In an embodiment, the booklet assembly  100  includes hardware appropriate for mounting a card  104  into the particular device cabinet  170 . The card  104  may be understood as a Printed Wiring Board (PWB) or, equivalently, a Printed Circuit Board (PCB) upon which various electronic components may be mounted for electronic interface with a computer system  174  (schematically represented as a box). The device cabinet  170  houses the computer system  174 . Example computer hardware systems where embodiments of the present invention may be applied include IBM® z System® servers and cabinets. 
     In an embodiment, the booklet assembly  100  further includes a backplane connector  108 . The backplane connector  108  may be incorporated into the card  104 , and may provide electronic communication to various components mounted to the card  104 . In an embodiment, the backplane connector  108  is configured to connect to a backplane socket  172 , and the backplane socket  172  is in electronic communication with the computer system  174 . The backplane connector  108  and the backplane socket  172  may be of the type commonly found as expansion board connectors in commercially available computer systems. In alternative embodiments, the backplane connector  108  may be incorporated into a side of the booklet assembly  100 , ninety degrees offset from its depicted position, as is the case in various desktop computer systems, and the structures disclosed elsewhere may be modified accordingly. 
     Referring still to  FIG. 1 , the card  104  may include a cable connector  106 , which may connect to one or more types of cable connectors, whereby communication between the computer system  174  and other computer systems or devices is enabled. The card  104  may conform to a large form factor consistent with the size of the booklet  100 . The inventors have observed and/or recognized that, where the primary function of the card  104  is to facilitate communication via the cable connector  106  by the computer system  174 , due to recent reductions in the size and cost of integrated circuit chips, as well as recent increased needs to improve signal integrity performance and/or reduce the cost of manufacture, the card  104  may be substantially reduced in length relative to a given form factor to which the booklet  100  conforms. For example,  FIG. 2  depicts a card  204  that is of reduced length relative to the full length card  104 . The length of the card  104  necessitates the use of a retimer chip  102  to coordinate signals across the PWB of the card  104 . By reducing the length of the card  104 , the retimer chip  102  may no longer be necessary, and the resulting short card (e.g., the card  204 ) may be less fragile than the full length card  104 , thereby requiring less structural support from the booklet  100 . 
     The resulting short card  204  may also be less costly to produce and distribute, consume less power, require fewer capacitors (e.g., filtering, blocking, and/or decoupling capacitors), and have simple thermal management than the full length card  104 . However, the inventors have observed and/or recognized that the short card  204  necessitates bringing the cable connector  106  inside the booklet  100 , which puts the cable at risk of damage by contacting potentially sharp internal structures of the booklet  100  and/or device cabinet  170 . This may also put the cable at risk of accidental disconnection, if internal components place unexpected tension on the cable. Similarly, moving the cable connector  106  inside the booklet  100  creates a risk of altering airflow through the device cabinet  170  in unexpected ways. The inventors have observed and/or recognized that a system can incorporate the benefits of a short card without the drawbacks of a cable connector deep inside the booklet by providing a cassette into which a preexisting cable assembly may be preloaded and/or pre-retained. It should be noted, however, that no particular aspect of the aforementioned benefits of short cards, drawbacks of long cards, drawbacks of internally mounted cable connectors, or benefits of cassettes need necessarily be present in any particular embodiment of the invention. 
       FIGS. 2-4C  collectively depict various views and components for one or more embodiments of the present invention.  FIG. 2  presents a plan view of a cable assembly, cassette, and reduced form factor card, in accordance with at least one embodiment of the invention. In the depicted embodiment, the card  204  is mounted internally to the booklet assembly  200 . Mounting may be accomplished with any appropriate fastener, such as the depicted screws  205 ; alternatives include nails, adhesives, bolts, and rivets. A backplane connector  208  is integrated into the card  204 , and a cable connector  206  is mounted thereon, both in electronic communication with the card  204 , its components, and any computer system that may be connected via the backplane connector  208 . The cable connector  206  may be understood as being affixed internally to the booklet assembly  200 , regardless of whether, in alternative embodiments, a card  204  is present or not. The apparatus of the depicted embodiment includes a cassette  220 . The cassette  220  is shown isolated from the booklet assembly  200  at  FIG. 3A . 
     Referring still to an embodiment depicted in  FIGS. 2-4C , the cassette  220  retains a cable assembly  230 . The cable assembly  230  includes a cable  232 , which connects electrically, optically, or otherwise to a cable head assembly  234 , which includes a connector jack  236 . The cable assembly  230  is configured for insertion into the cable connector  206  via the connector jack  236 . The cable assembly  230 , as depicted, is a PCIe cable assembly. In alternative embodiments, the present invention may be applied to other standard or non-standard cable types that may be usefully connected to the card  204 , such as Ethernet, Universal Serial Bus (USB), etc. Various embodiments may include custom cable types and/or embodiment-specific cable types. Embodiments that use a preexisting cable assembly  230 , specifically a cable that is manufactured and commercially available off-the-shelf and conforming to one or more defined standards, may benefit in that such embodiments require only the manufacture of the cassette  220 , with other components already available (though this advantage is not a necessarily a requirement for any particular embodiment). 
     Referring still to an embodiment depicted in  FIGS. 2-4C , the cassette  220  includes a carriage  250 , which includes at least one hook structure, in a depicted embodiment including a rear right hook structure  252 R, a rear left hook structure  252 L, a front right hook structure  254 R, and a front left hook structure  254 L. The carriage may be made of various rigid or semi-rigid metal or plastic materials. The carriage  250  is retained internally to the cassette  220 . As described herein, “retained” includes not only completely fixed configurations, but also includes configurations where movement in various dimensions is permitted, subject to mechanical restriction. The carriage may  250  may be understood as including a carriage panel with a carriage panel top face  251  to which the hook structures  252 R,  252 L,  254 R, and  252 L may be understood as affixed to or monolithically incorporated into the carriage panel top face  251 . The four hook structures  252 R,  252 L,  254 R, and  252 L are shaped to conform to the cable head assembly  234  such that the cable head assembly  234  is retained to the carriage  250 , as depicted. Thus, the carriage  250  may be understood as being configured for retaining the cable assembly  230 . In alternative embodiments, different numbers and shapes of retaining structures may be incorporated into and/or affixed to the carriage  250 , and such structures may accommodate the same shaped cable assembly  230  differently or may accommodate a differently shaped cable assembly  230 , for example a cable assembly conforming to a different cabling standard. 
     Referring still to an embodiment depicted in  FIGS. 2-4C , the cassette  220  includes a cassette base  221 . The cassette base  221  may be a flat (or about flat, permissive of holes, raised regions depressed regions, etc.) rectangular (or about rectangular, permissive of indentations, outcroppings, fabrication errors, etc.) structure of rigid or semi-rigid material, such as sheet metal. The cassette base  221  includes a cassette base top surface  221 A (in the drawings, the cassette base  221  refers to the three dimensional panel while the cassette base top surface  221 A refers to its two dimensional top surface), a cassette base front edge  221 F, a cassette base right edge  221 R, a cassette base rear edge  221 B, and a cassette base left edge  221 L. Alternative shapes of the cassette base  221  and the cassette  220  as a whole are contemplated, for example where the device cabinet  170  accepts an alternatively shaped booklet  100 . 
     Referring still to an embodiment depicted in  FIGS. 2-4C , affixed to or incorporated monolithically into the cassette base  221 , perpendicularly and upward thereto along the cassette base front edge  221 F is a cassette front panel  222 , which incorporates a full-height or partial height front panel gap  222 A. The front panel gap  22 A accommodates the connector jack  236 . More, fewer, or differently shaped gaps may be incorporated into the cassette front panel  222 , as required to accommodate differently shaped jacks or other components. Affixed to or incorporated monolithically into the cassette base  221 , perpendicularly and upward thereto along the cassette base rear edge  221 B is a cassette rear panel  226 , which incorporates a full or partial height cassette rear panel central gap  226 A. The cassette rear panel central gap  226 A accommodates the cable  232 . The edges of the cassette rear panel central gap  226 A may be folded over, as shown, or, alternatively, the edges may be smoothed, sanded, rounded, or otherwise rendered non sharp, which reduces the risk of shearing the cable  232 . More, fewer, or differently shaped gaps may be incorporated into the cassette rear panel  226 , as required to accommodate differently shaped cables or other components. As shown, a cassette rear panel left gap  263  and cassette rear panel right gap  264  may also be cut into the cassette rear panel  262 , as described in further detail below. 
     Referring still to an embodiment depicted in  FIGS. 2-4C , affixed to or incorporated monolithically into the cassette base  221 , perpendicularly and upward thereto along the cassette base right edge  221 R is a cassette right panel  225 , and affixed to or incorporated monolithically into the cassette base  221 , perpendicularly and upward thereto along the cassette base left edge  221 L is a cassette left panel  224 . The cassette right panel  225  may have cut therefrom a cassette right panel gap  225 A, and the cassette left panel  224  may have cut therefrom a cassette left panel gap  224 A. More, fewer, or differently shaped gaps cut from the cassette left panel  224  and cassette right panel  225  are also contemplated. 
     Referring still to an embodiment depicted in  FIGS. 2-4C ,  FIG. 4A  introduces an insertion dimension  400 . The front panel gap  222 A and the carriage  250  are aligned along the insertion dimension  400 . The carriage  250  may be retained to the cassette base  221  such that the cassette base top surface  221 A opposes the carriage panel bottom surface  451 , and that the carriage  250  is translationally movable along the insertion dimension  400 , relative to the cassette  220 , and the cable assembly  230  inserts into the cable connector  206  along the insertion dimension  400 . Thus, the cable assembly  230 , retained to the carriage  250 , may be adjusted positionally relative to the cassette  220  to obtain and retain optimal mating between the connector jack  236  and the cable connector  206 . The carriage  250  may be urged along the insertion dimension  400  thus pressing the connector jack  236  into the cable connector. In a depicted embodiment, one possible urging means for urging the connector jack  236  into the cable connector  206  includes a left lever and a right lever. The left lever includes a left lever arm region  258 L and a left lever fulcrum region  259 L. The right lever includes a right lever arm region  258 R and a right lever fulcrum region  259 R. Each of the two levers may be configured to urge the carriage  250  forward along the insertion dimension by spring action. Thus, the cassette  220  may be understood to include at least one spring-loaded member (one of the levers, including the left and right lever arm regions  258 L and  258 R) affixed internally thereto, and the at least one spring-loaded member may be understood as being configured to urge the carriage  250  along the insertion dimension such that the cable assembly is urged into an inserted position. 
     Accordingly, the levers may be made of an intrinsically deformable material, such as various metal or plastic materials that have spring properties. The levers may be constructed as a single piece with various other elements described below, and the single piece may be retained to the cassette  220  by one or more snap fasteners  402 , which may retain the lever and associated components to the cassette  220 . Alternative fasteners include screws, nails, bolts, adhesives, hook-and-loop fabric, etc. 
     Referring still to an embodiment depicted in  FIGS. 2-4C ,  FIG. 4B  depicts how translational movability of the carriage  250  along the insertion dimension  400  may be achieved incorporating into the cassette base  221  a slot  410 . The slot  410  includes a first slot region  412  and a second slot region  411 . The first slot region  412  is wider than the second slot region  411 , as depicted.  FIG. 4C  depicts the carriage panel bottom face  451 . The carriage  250  further includes a tongue  420  affixed to or incorporated monolithically thereto, for example via the carriage panel bottom face  451 . The tongue  420  includes a narrow region  421  and an enlarged region  422 . The narrow region  421  is affixed between the enlarged region  422  and the carriage panel bottom face  451 , such that the tongue  420  has a T-shaped profile, as shown. The enlarged region  422  is of lesser width than the second slot region  411  and greater width than the first slot region  412 . The narrow region  421  is of lesser width than the second slot region  411 . Thus, in a depicted embodiment, the tongue  420  is insertable into the first slot region  412  and slidable into the second slot region  411  such that, when the tongue  420  is disposed within the second slot region  411 , the carriage  250  is retained to the cassette base  221  slidably, along the insertion dimension  400 . Thus, the tongue  420  may be understood as configured for insertion into and retention by the slot  410  such that the tongue is restricted to motion along the insertion dimension  400 . 
     Referring still to an embodiment depicted in  FIGS. 2-4C , the cassette  220  is configured for insertion into the booklet assembly  200 . In some configurations of a depicted embodiment, the cassette  220  is inserted into and retained within the booklet assembly  200 , and the cable assembly  230  is inserted into the cable connector  206  and retained in an inserted position by the carriage  250 . The inserted position may be understood to include a position, such as that depicted in  FIG. 2 , where the connector jack  236  is mated to the cable connector  206  such that electronic communication between the cable assembly  230  and the card  204  is enabled. 
     Enabling insertion and retention of the cassette  220  into the booklet assembly  200 , the cassette  220  includes a plurality of tabs. The plurality of tabs is configured for releasably interlocking with the booklet assembly  200 . More specifically, in an embodiment depicted in  FIGS. 2-4C , the cassette  220  includes a left tab and a right tab. The left tab includes a left tab handle region  262 L, a left tab bend region  264 L, and a left tab fulcrum region  266 L. The right tab includes a right tab handle region  262 R, a right tab bend region  264 R, and a right tab fulcrum region  266 R. In a depicted embodiment, each tab is a single piece together with the corresponding lever, retained by the fasteners  402 . Specifically, the left tab fulcrum region  266 L and right tab fulcrum region  266 R may be understood as affixed internally to the cassette  220 , as depicted. In alternative embodiments, the levers and tabs may be distinct structures. 
     Referring still to an embodiment depicted in  FIG. 2-4C , the left tab bend region  264 L may extend through the cassette left panel gap  224 A, and the right tab bend region  264 R may extend through the cassette right panel gap  225 A. The left tab handle region  262 L extends through the cassette rear panel left gap  263 L, and the right tab handle region  262 R extends through the cassette rear panel right gap  263 R. The left tab is urged toward the cassette left panel  224  by spring action of the left tab fulcrum region  266 L, and the right tab is urged toward the cassette right panel  225  by spring action of the right tab fulcrum region  266 R. Thus, the tabs may be understood to be spring-loaded. The left tab is urgable away from the cassette left panel  224  by actuation of the left tab handle region  262 L (for example, manual pushing rightward by a human user of the left tab handle region  262 L). The right tab is urgable away from the cassette right panel  225  by actuation of the right tab handle region  262 R (for example, manual pushing leftward by a human user of the right tab handle region  262 R). Thus, each of the plurality of tabs may be understood as actuated by a lever. Resultingly, the left tab bend region  264 L and right tab bend region  264 R may be configured to engage with corresponding structures interior to the booklet assembly  200  such that, if inserted into the booklet assembly  200 , the cassette  220  is retained by the left tab bend region  264 L and right tab bend region  264 R snapping into place. Similarly, the cassette  220  is releasable from the booklet assembly  200  by a user actuating both the left tab handle region  262 L and right tab handle region  262 R, whereby the left tab bend region  264 L and right tab bend region  264 R disengage from the booklet assembly  200 , releasing the cassette  220  therefrom. Thus, via the left and right tabs, the cassette  220  may be understood as configured for insertion into the booklet assembly  200 . 
     Referring still to an embodiment depicted in  FIG. 2-4C ,  FIG. 3B  presents an optional light pipe  370  affixed internally to the cassette  220 . A light source  207  (shown in  FIG. 2 ) may be affixed to the cable connector  206 . The light source  207  may be a status indicator, such as Light Emitting Diode (LED) that is configured to blink or otherwise present status information pertaining to the card  204 . The light source  207  may not, on its own, be visible from outside the device cabinet  170 . Addressing this in a depicted embodiment, the light pipe  370  includes a first end  207 A located at a light collection position whereat, if the cassette  220  is inserted into the booklet assembly  200 , light emitted by the light source  207  is collected by the light pipe. That is, the first end  370 A may be located proximate to the light source  207 . The light pipe  370  further includes a second end  370 B located at a light emission position whereat light emitted from the light pipe  370  unobstructedly propagates out of the cassette  220 . That is, the second end  370 B is located at the back of the cassette and is visible from outside of the device cabinet  170 . The light pipe  370  may be made of acrylic, glass, or other transparent but internally reflective material. The light pipe  370  may be affixed to the interior of the cassette  220  by adhesives, snap components, or other fasteners, and may be arranged on a path through the cassette  220  that avoids various other components. For example, the light pipe  370  may pass under a notch  358 A in a lever arm region  358  (corresponding to the right lever arm region  258 R and left lever arm region  258 L). 
     Referring still to an embodiment depicted in  FIGS. 2-4C , a method of using the apparatus of the invention includes preloading the cable assembly  230  into the carriage  250 . To achieve this, the cable head assembly  234  may be pressed into carriage  250  such that the hook structures  252 L,  252 R,  254 L, and  254 R snap around the cable head assembly  234 . The method further includes inserting the cassette  220  into the booklet assembly  200 . For example, the cassette  220  may be pressed into the booklet assembly  200  until the left tab bend region  264 L and right tab bend region  264 R snap into place. The method further includes configuring the carriage  250  such that the cable assembly  230  is inserted into the cable connector  206  and retained in the inserted position by the carriage  250 , for example by adjusting the position of the carriage  250  along the insertion dimension  400 . The method may further include inserting the booklet assembly  200  into the device cabinet  170  such that the backplane connector  208  is inserted into the backplane socket  172 . 
     Referring now to an embodiment depicted in  FIGS. 5-6B , the booklet assembly  500  includes a card  504  with a cable connector  506  and backplane connector  508 , similarly to the previously described embodiments. The cable assembly  530 , cable  532 , cable head assembly  534 , and connector jack  536  likewise function similarly to the previously described embodiments. The cassette  520 , cassette base  521 , carriage  550 , carriage panel top face  551 , hooks  552 L,  552 R,  554 L, and  554 R, tab bend regions  564 L and  564 R, and tab handle regions  562 L, and  562 R likewise function similarly to previously described embodiments. 
     In an embodiment depicted in  FIGS. 5-6B , the cassette  520  includes a jack screw  590 . The jack screw  590  rotates within a jack screw retainer  591  resulting in adjustable translational motion along the insertion dimension  400 . The jack screw retainer  591  is affixed to or incorporated into the cassette base  521 . By the jack screw retainer  591 , the jack screw  590  may be understood to be mounted internally to the cassette  520  such that the jack screw  590  is rotatable about and translatable along the insertion dimension  400 . The jack screw  590  may engage with a receiving structure  550 A affixed to or incorporated into the carriage  550 . By rotating the jack screw, users may adjust the degree to which the carriage  550  is urged along the insertion dimension  400 . Thus, the jack screw  590  may be understood to be configured to urge the carriage along the insertion dimension  400  such that the cable assembly is urged into an inserted position. Equivalently, the jack screw  590 , together with the jack screw retainer  591  and receiving structure  550 A may be understood to be an urging means for urging the connector jack  536  into the cable connector  506 . 
     Referring still to an embodiment depicted in  FIGS. 5-6B , the cassette rear panel center gap  526 A in the cassette rear panel  526  may be reduced, as shown, leaving a panel through which the cable  532  may pass via one or more holes. An additional central hole  592  may permit a user to insert a screwdriver to access the jack screw  590 . 
     Referring now to an embodiment depicted in  FIGS. 7-8 , the booklet assembly  700  includes a card  704  with a cable connector  706  and backplane connector  708 , similarly to the previously described embodiments. The cable assembly  730 , cable  732 , cable head assembly  734 , and connector jack  736  likewise function similarly to the previously described embodiments. The cassette  720 , cassette base  721 , carriage  750 , and hooks  752 L,  752 R,  754 L likewise function similarly to previously described embodiments. 
     In an embodiment depicted in  FIG. 6-8 , the carriage  750  is not slidable relative to the cassette  720 , but rather is affixed to the cassette base  721  via fasteners  751 , which may include screws, nails, bolts, rivets, snapping structures, adhesives, hook-and-loop fabric, etc. Thus, the carriage  752  is fixedly positioned within the cassette  720 . In addition, an embodiment of  FIG. 7-8  may replace the tabs with retaining hooks  744 R and  744 L, each including a retaining hook tip  745 R and  745 L, which pass through the right and left panel gaps  725 A and  724 A to engage with corresponding structures on the interior of the booklet assembly  700 . In addition, the retaining hooks exert tension between the cassette  720  and a booklet back panel  746 , thus urging the entire cassette  720  forward along the insertion dimension  400  such that the connector jack  736  is urged into the cable connector  706 . Thus the retaining hooks  744 L and  744 R may be understood to be an urging means for urging the connector jack  736  into the cable connector  706 .