Abstract:
An anti-reversal end cap with tab to prevent improper stowage of a handset into its cradle. The end cap is formed by joining two members together to route a cable from an in-flight entertainment system to the handset. The end cap has a protruding tab which interferes with the cradle if the handset is improperly stowed. The end cap can be taken apart to free the cable from the handset such that the cable does not need to be re-terminated. The tab on the end cap has a generally wedged shape to prevent binding with the cradle and to ensure smooth ejection.

Description:
FIELD OF THE INVENTION 
     The present invention relates to in-flight entertainment systems (“IFE”) provided by passenger aircrafts, and more particularly relates to the universal controller handsets used by passengers to interact with the in-flight entertainment systems. 
     ART BACKGROUND 
     With the advent of technology, traveling on passenger aircrafts has become quite some experience. Each passenger&#39;s seat not only offers an individual screen for movie viewing, it also allows the passenger to play interactive video games, or browse the in-flight duty-free shop, by using a controller handset. Pretty soon, passengers will be able to surf the worldwide web during flight. As people become more connected on the ground, some airlines have gone as far as installing individual telephone handsets at each passenger&#39;s seat, so that business can still be conducted at 30,000 feet above ground. Not to be mistaken, airlines offer these amenities to increase customer satisfaction, as well as their own revenue derived from goods sold and in-flight telephone calls made. 
     With all these electronics and communications options available to a passenger at her fingertips, it would have been unthinkable to have multiple gadgets and wiring for the passenger to manipulate at her seat. A universal passenger control unit (“UPCU”) is thus developed to integrate all the passenger&#39;s electronics and communications controls into one handset. A typical model of such universal handset has been provided to numerous airlines by Passenger Systems division of Rockwell Collins, Inc., the assignee of the present application, as shown in FIG.  1 . 
     As shown in FIG. 1, handset  10  is constructed to provide multiple control functions such as video game control  105 ,  140 ,  145 ,  146 , audiovisual programming  130 , channel and volume adjustment buttons  110 , status screen  120  and of course attendance call/cancel buttons  100 . In additional to providing control functionality, the flip side of handset  10  (not shown) is constructed to operate as a telephone handset. 
     When not in use, handset  10  is stowed in a cradle (illustrated in FIGS.  2  and  3 ), which is typically installed in the seat arm, on top or on the side. The normal position is to stow handset  10  with its controller side facing up. This way, passengers can still use handset  10  to control the audiovisual programming, change channels or stations, turn the overhead reading light on or off, or call the attendant, with handset  10  remaining in its cradle. 
     Handset  10  can also be removed from the cradle for the passenger to additionally play video games, browse the worldwide web or use the telephone features on the other side of handset  10 . When the passenger is finished with handset  10 , handset  10  can be stowed back into the cradle, hopefully with its controller side up. Cable  150  is also automatically retracted by a cord reel (not shown) attached to the cradle. The generally symmetrical shape of handset  10  and its universality make it very convenient to use and to handle, in addition to giving it an attractive look and feel. 
     Cable  150  links, through a retractable cord reel (not shown), the handset&#39;s control and telephone functionality to a server or switch located away from the armrest. When cable  150  is first installed with handset  10 , cable  150  is drawn from the cord reel and led through a removable end cap  151 , before its termination with a connector. The connector can then be plugged into a circuit board socket within handset  10 . End cap  151 , which serves as the mechanical interface between cable  150  and the cord reel, can then be securely attached to handset  10  by a temper-proof screw to prevent electromagnetic interference (“EMI”), electrostatic discharge (“ESD”) and environmental hazards from affecting handset  10 . As is commonly the practice, end cap  151  makes it possible to repair or replace handset  10 , when it needs servicing. All the field crew needs to do is to unscrew end cap  151 , unplug the cable connector and handset  10  can be removed. 
     There are some drawbacks associated with the generally symmetrical shape and universality of handset  10 . The symmetry makes it more likely that a passenger will stow the handset back to its cradle with the controller side facing down, thus preventing the passenger from using the controlling functions later on. Sometimes, the handsets are improperly stowed and they end up being stuck in the cradle. 
     To facilitate proper stowage of the handset and to preserve the symmetrical look and feel, the cradle and handset assembly has been designed to achieve better fit when it has the proper face up, while making the fit more awkward and resistant, if the handset has the wrong face face up. However, because the handset is generally symmetrical, a passenger is not likely to notice the feel of friction, or resistive awkwardness, when the handset is improperly inserted. In fact, airlines have found that many passengers simply push and shove harder to get the handset into the cradle, being totally unaware of the difference. Many handsets have been found to suffer damages and cracks due to passenger abuse or misuse. At a cost of several hundred dollars per handset, such replacement cost is quite high, not to mention field repair cost and down-time during flight. 
     Thinking in terms of bottom line, airlines would like to prevent damages based on improper stowage, without comprising the look and feel. On the other hand, airlines cannot afford to replace all the handsets and cradles already in the tens of thousands of installed units. Further, any replace or retrofit efforts must be straightforward enough for the field team to do. As such, efforts involving replacing parts of the handsets by cutting the cable will not work, since cables will now have to be re-terminated and connected. 
     Therefore, it is desirable to be able to make the handset anti-reversal without having to change the major components or modify existing general design and fit between the handset the cradle. 
     It is also desirable to retrofit the handsets such that they are incapable of being stowed upside down, without having to uninstall the cradle from the seat arm. The improvement should be readily achievable by the field team. 
     It is further desirable to be able to replace the handsets, or separate the cable from the handset, without having to re-terminate the cable&#39;s connector, which is too costly a process, in time and money, for the field repair efforts. 
     SUMMARY OF THE INVENTION 
     An anti-reversal end cap with tab to prevent improper stowage of a handset into its cradle is disclosed. The end cap is formed by joining two members together to route a cable from an in-flight entertainment system to the handset. The end cap has a protruding tab which interferes with the cradle if the handset is positioned to be improperly stowed by the user. The end cap can be taken apart to free the cable from the handset such that the cable does not need to be re-terminated. The tab on the end cap has a generally wedged shape to prevent binding with the cradle and to ensure smooth ejection. 
     Another aspect of the invention is an end cap to ensure proper stowage orientation of a handset in a cradle installed at an airline passenger&#39;s seat. The end cap comprises a tab located and protruding at a predetermined position on the end cap, in such a way that the tab fits through an opening on the cradle only when the handset is stowed properly. The tab interferes with the opening on the cradle to prevent said handset from being fully placed inside the cradle when the handset is placed in the cradle at an improper orientation. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Additional objects, features and advantages of the present invention will become apparent from the following disclosure, wherein: 
     FIG. 1 shows an example of a conventional controller handset. 
     FIG. 2 shows handset  20 , with its telephone side up, in accordance with the present invention partially in the cradle  200 . 
     FIG. 3 shows another view of handset  30  being improperly stowed in cradle  300 . 
     FIG. 4 shows handset with its anti-reversal tab  440  and end cap  430 . 
     FIG. 5 shows handset  510  with its telephone side up. 
     FIG. 6 shows an isometric view of the anti-reversal end cap in accordance with the present invention. 
     FIGS.  7 ( a ),  7 ( b ),  8 ( a ) and  8 ( b ) show isometric views and cross-sectional views of the bottom half  620  and top half  610  are shown, respectively. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     An anti-reversal end cap for universal handset controller is disclosed. It should be noted that the present invention is described in terms of commonly known components and devices, which are the means generally used by those skilled in the art to communicate with each other. Based on the disclosure that follows, those skilled in the art can readily practice the present invention, without undue experimentation, for their intended purposes. 
     FIG. 2 shows handset  20  partially in the cradle  200  with its telephone side, i.e. wrong side, up. An end panel  210 , known as the “venturi,” locates at one end of cradle  200  to protect cable  250  and its cord reel. Venturi  210  has horse-shoe shaped opening (as shown in FIG.  3 ). An anti-reversal tab  240  implemented on the end cap of handset  20  is shown interfering with venturi  210  in handset&#39;s downward motion to prevent further insertion. If handset  20  has its controller side up, anti-reversal tab  240  fits through the opening on venturi  210  easily. Also, when handset&#39;s downward movement is blocked by tab  240  hitting the venturi  210 , the other end of handset  20  can only lean on the edge  220  of cradle, thus making it impossible that a passenger will continue to shove handset  20  down into cradle  200  even when it has the wrong side up. 
     FIG. 3 shows another view of handset  30  being improperly stowed in cradle  300 . Note that cable  350  passes through an opening on the venturi piece  310 . The opening is shaped, currently in a horse-shoe shape, such that the anti-reversal tab can only fit through the opening, when handset  30  is stowed with its proper side up. 
     FIG. 4 shows handset with its anti-reversal tab  440  and end cap  430 . Strain relief  450  surrounding the cable distributes the bending load over a large area when the cable is flexed and bent, which is typical of how a passenger handles the handsets. End cap  430  and anti-reversal tab  430  are made of material such as Lexan 940A, available from GE Plastics, with tab  440  being positioned in parallel with strain relief  450  as cable enters end cap  430 . Tab  440  and strain relief  450  work in conjunction with each other to sustain much greater forces of impact or abuse, than would each individually. 
     FIG. 5 shows handset  510  with its telephone side up. Anti-reversal tab  540  on end cap  530  takes the general shape of a wedge and is positioned above cable&#39;s strain relief  550 . While the tab-and-end cap assembly in accordance-with the present invention shows tab  540  positioned on top when the telephone side is up, it should be apparent to those skilled in the art that tab  540  can be located elsewhere based on the given design of the handset and cradle. For the cradle and opening shown in FIG. 3, the location and shape of tab  540  is relative to how tab  540  is intended to interfere with the opening, or the absence thereof, on the venturi piece of the cradle. 
     Reference is now turned to FIG. 6, where an isometric view of the anti-reversal end cap in accordance with the present invention is illustrated. Currently, the end cap is made by assembling top half  610  and bottom half  620  into a unitary piece, which can then be installed to the handset. Tab  630  has a general angled and wedged shape, and overlaps the opening  650  for the cable&#39;s strain relief. Tab  630  serves to inhibit downward movement of the handset if it is upside down, by interfering with the venturi piece of the cradle. If the handset is stowed correctly, tab  630  smoothly nests in the opening of the venturi piece. As can be appreciated by those skilled in the art, the end cap with tab  630  increases the effective length of the handset if the handset is upside down, while fitting through the opening of the venturi piece if the handset is correctly placed in its cradle. 
     The angled profile of tab  630  also has the advantage of deflecting any impact away from itself for self-protection, as well as making the handset eject more easily from the cradle. Additionally, opening  650 , through which the cable is directed, is preferably positioned in such a way that it overlaps with tab  630 . Such overlapping allows both of them, together, to withstand much greater forces of impact and abuse than would each individually. 
     Referring to FIGS.  7 ( a ),  7 ( b ),  8 ( a ) and  8 ( b ), isometric views and cross-sectional views of the bottom half  620  and top half  610  are shown, respectively. Passage  725  is positioned to overlap with tab  740 , for the reasons described above. Enclosed channel  728 ,  828 , which is formed when both halves are joined, is provided to route the cable with a lock  734 ,  834 , which retains a crimp ring on the cable. As can be appreciated by those skilled in the art of Federal Aviation Administration&#39;s IFE requirements, a handset and its cable must withstand a minimum pull-off force, e.g. 20 lb, expected from users. As the cable is directed into the end cap through passage  725 , its crimp ring is secured by lock  734 ,  834  together. The cable then winds its away through enclosed channel  728 ,  828 , and reaches the circuit board inside the handset. 
     The two halves of the end cap are interlocked and secured to the handset as follows: As in the Lego® blocks, indentations  710  and  720  are formed as a female-type lock, while their counterparts male-type  840  and  830  are correspondingly positioned on the upper half of the hand cap. When the two halves are joined together like Lego® blocks, ring-shaped locks  731 ,  831  allow a screw, e.g. temper-proof screw, through to fasten both halves to the handset at the same time. It should be pointed out that in order to optimize field repair efforts, the passage  725  and enclosed channels  728 ,  828  are only formed when the two halves are joined together. In other words, when the two halves are separated, the passage  725  is laid open and the cable can be readily removed from the end cap, with the cable&#39;s connector intact. This can all be done without having to re-terminate the cable&#39;s electrical connectors. 
     As can be appreciated by those skilled in the art, an end cap may comprise of only one piece to still satisfy both the anti-reversal and ease of field repair requirements, if the limitations of the current handset design are varied slightly. For example, instead of forming passage  725  with two halves of the end cap, it may be constructed such that a portion of passage  725  is pre-formed by the handset&#39;s case itself, with the end cap closing to form the complete passage  725 . When the end cap is subsequently removed, the passage opens up and the cable can be removed. Also, the dimension, location, angle and shape of the protruding tab may be modified based on the shape and location of the opening on the venturi piece, if called for by the design of the handset and the cradle. 
     As disclosed, the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiments are to be considered in all respects as illustrative, and not restrictive. The scope of the invention is therefore, indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.