Abstract:
An aircraft luggage box lock includes a stationary housing and a cover moveable about a rotary axis. The lock includes a locking pin device mountable on the housing, having two parallel locking pins, a catch mountable on the cover having two locking hooks pivotable about a pivot axis for receiving the pins for locking the lock, and a manually actuatable drive device for jointly pivoting the locking hooks away from the locking pins for unlocking the lock. The drive device has a gear rack and a sliding element linearly displaceable against pressure of a spring element. The locking hooks are connected to the gear rack or the sliding element by a knee lever hinged to the closing hook adjacent to the pivot axis thereof in such a way that the lock is openable only by tensile force acting on the hinged point of the knee lever on the locking hook.

Description:
BACKGROUND 
     The invention relates to a lock for a luggage box installed overhead in the cabin of an aircraft, comprising a stationary housing and a lid that is articulated about a rotary axis, having a locking pin device that is or can be arranged on the housing, carrying at least one locking pin, and at least one catch that is or can be mounted on the lid which comprises at least one locking hook that is articulated about a pivot axis for engaging the locking pin to lock the lock, and with a manually actuatable drive device for pivoting the locking hook away from the locking pin to unlock the lock. 
     The primary function of such a lock is to securely lock and unlock the lid or luggage bin or container of a luggage box in all flight conditions including emergency landing conditions. The drive device within the lock is connected by a mechanical connection member to an operating button or handle, which is mounted on the lid such that it can be operated from outside the luggage box. The operation of the button or handle leads in the known lock to a rotary motion of the mechanical connection means by which the lock is unlocked. Here, the lock is embodied such that an unintentional opening in the loaded or unloaded state of the luggage box is prevented. In aeronautical engineering it is required that the lock is provided with a fail-safe function. For this purpose, a dual lock is provided. In the known lock, this dual locking is achieved on the one hand by a locking pin, which is engaged by a locking hook and on the other hand by a catch pin, which for the opened lid of the luggage box projects from the catch, however upon closing the lid of the luggage box it is pressed into the housing of the catch by the locking pin device. Both the locking pin as well as the catch pin are each individually capable of carry the required loads. 
     In the known locking mechanism for a luggage box it is problematic that two locks must be operated by the pivotal handle provided in the middle of the lid, which is arranged at one and/or the other end of the lid, for which the pivotal handle and the two shafts must be assembled on one axis for both catches. The pivotal handle performs a rotary motion, which via the shafts is transmitted to the catches of the locks. In each catch the rotary motion is respectively transferred into a pivotal motion of the locking hook. Completely independent therefrom, the catch pin of each lock is brought into its locking position by closing the lid. The locking pin device presses the catch pin, which pass said arrangement, into the housing of the catch. When the locks and the pivotal handle cannot be mounted on one axis, the known lock cannot be used at all. Further, it is problematic that the construction of the shafts and their mounting at the lid required for operating the lock of prior art leads to additional weight, higher expenses for parts, and an increased assembly expense, all of which being extremely undesirable in aeronautical engineering. Finally, in the lock of prior art the locking pin device can be adjusted in two axes. The locking pin simultaneously serves as a contact for a final stop. This is disadvantageous in that with every adjustment of the locking pin device, the contact of the final stop must also be adjusted and set. Additionally, the opening of the lock occurs by pulling the operating handle. Due to the fact that no transmission is provided between the operating handle and the shaft, higher operating forces are required. 
     A lock for housings, tool boxes, or the like is known from US 2002/00 56 296 A1. This lock has two locking pins on a lid and two locking hooks pivotal about a pivotal axis, which are pivoted jointly at a manually actuated drive arrangement. A luggage box in an airplane must have two locks, which can be operated by a joint operating button. The known lock is unsuitable for this purpose. It can be operated by two push buttons, which are arranged at the left and the right of the lock. The push buttons are connected to the locking hook by a common stiff operating member, with the displacement thereof allowing both locking hooks to be pivoted. Such a lock may not be used for the luggage box of an aircraft because the locking hooks cannot be operated separately. When one locking hook becomes blocked, here the other locking hook would also be blocked. 
     From GB 2 168 748 A, a lock is known for locking a sliding door to a door frame. The lock comprises two locking hooks respectively pivotal about a pivot axis, which are pivoted jointly via a drive arrangement in the form of a gear rack. This known lock is not suitable for a luggage box of an airplane, either, because both locking hooks, at least in the opening direction, can only be pivoted jointly. When one locking hook becomes blocked in the closed state the other locking hook also could no longer be opened by the drive device. 
     SUMMARY 
     The objective of the invention is to provide a lock of the type mentioned at the outset, which avoids the above-mentioned disadvantages and particularly can be used in a luggage box, even when the operating button or handle is not positioned on the axis of the catch. 
     This objective is attained according to the invention in that the locking pin device carries two locking pins, that the catch comprises two locking hooks each pivotal about a pivotal axis, that the drive arrangement is embodied for a joint pivoting of the locking hook, the drive arrangement comprises a gear rack and a sliding member, arranged successively in a linear guide, pre-stressed by the pressure of a spring element in the direction towards a stop, and displaceable by manual operation against the pressure of the spring element in the direction away from the stop, that the drive arrangement comprises a gear rack, that the gears of the gear rack can engage and be operated by a cable pull. 
     The lock according to the invention can be unlocked by an operating pull, which is mounted invisibly inside the lid (luggage bin or container). The use of a light operating pull is advantageous with regards to weight. The assembly is uncomplicated because operating pulls can be assembled much easier than shafts and levers made from CFK. The lower weight and the lower assembly expenses are further complemented by lower costs for parts. The primary advantage of the lock according to the invention is that the catch and the operating button or handle are not required to be assembled on a joint axis. The fail-safe function is ensured such that the catch has two locking hooks and that each locking hook engages a locking pin such that, when one of the locking pins or locking hooks malfunctions, the other locking pin and the other locking hook can compensate the entire load. Due to the fact that the two locking hooks are connected to a gear rack and the slider, which in turn only contact under spring pressure but otherwise show no mutual mechanical connection, the lock can also be securely locked when only one locking hook is able to engage the corresponding locking pin. The linear pulling motion created by the operating button is transferred into a rotary motion, which in turn leads to a translational motion of the gear rack and the sliding element, entraining the two locking hooks and pivoting them around their pivotal points. The operation by a cable pull results in a simple, trouble-free, low-weight operation for the gear rack and renders unnecessary the previously used shafts of known luggage boxes. The two locks and the pivotal handle of a luggage box are no longer required to be mounted on one axis. 
     Advantageous embodiments of the lock according to the invention form the subject matter of the sub-claims. 
     In one embodiment of the lock according to the invention, the locking hooks are each connected to the gear rack and/or the sliding element via a knee lever, which is linked at the locking hook next to its pivotal axis such that the locking position can only be opened by the effect of a tensile force upon the link of the knee lever at the locking hook. This allows in a simple fashion the fail-safe (dual locking) and positive locking required in aeronautical engineering. The latter is achieved according to the invention such that the knee levers can each be brought into a final locking position in which they are mechanically locked and this way automatically prevent any opening of the lock by overload or vibration. 
     In another embodiment of the lock according to the invention one of the two knee levers is extended beyond its linking point at the corresponding locking hook and embodied as a preliminary trigger lever to displace the gear rack. In a luggage box in which the lid commonly is simply closed without additionally operating an operating button the locking motion of the lid is ensured by a locking pin contacting the preliminary trigger level such that both locking hooks are opened in order to subsequently accept both locking pins. 
     In another embodiment of the lock according to the invention, the gear rack comprises an additional gearing, which engages sprockets of an emergency operating lever supported in a pivotal fashion. If the locking hook allocated to the gear rack, for example due to a broken spring element, is blocked in the open position the lock fails to lock, and here a feedback is given to the operating personnel. In this case, the locking hook and thus the lock can manually be locked and unlocked, and subsequently servicing must occur. In this case the luggage can still be removed and it can be ensured that the lock securely locks with only one locking hook. If the locking rack allocated to the gear rack is stuck in the closed position and cannot be unlocked by manual operation with the help of an emergency operating lever, the lock remains locked and must be serviced. This means that the luggage can only be removed after the repair. 
     In another embodiment of the lock according to the invention the locking pins have different diameters. When one of the locking pins cannot engage the corresponding locking hook it is ensured that at least the other locking hook allocated to the locking pin with the smaller diameter engages said locking pin. 
     In another embodiment of the lock according to the invention the two locking hooks are embodied identically. Although it is possible to use two locking pins having the same diameter and instead using locking hooks in which the openings that receive the locking pins have a different clear width, however this would be the more expensive solution with regards to warehousing spare parts and assembly. 
     In another embodiment of the lock according to the invention the locking hook, which can be engaged by the locking pin with the smaller diameter, is allocated to a knee lever embodied as a preliminary trigger lever. This ensures that at least the locking hook connected to the gear rack can in any case be brought into a position in which it can receive the locking hook with the smaller diameter even if for example the spring element might be broken. Here, due to the smaller diameter of the locking pin it is not required for the locking hook and the locking pin to be precisely aligned. 
     In another embodiment of the lock according to the invention, in order to lock the lock, the locking hook allocated to the knee lever embodied as a preliminary trigger lever, with the help of an emergency lever, can manually engage the locking pin with the smaller diameter even when the other locking pin is not engaged with the other locking hook. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the following, the exemplary embodiments of the invention are described in greater detail with reference to the drawings. Shown are 
         FIG. 1  a lock according to the invention in a side view with an opened catch housing and in the locked state, 
         FIG. 2  the lock according to the invention in a view similar to  FIG. 1  but in the unlocked state, 
         FIG. 3  the lock according to  FIG. 2  but in a view from the rear, 
         FIG. 4  the catch of the lock according to  FIGS. 1-3  in an exploded illustration, 
         FIG. 5  a detail of a locking pin device, with for reasons of clarity only two locking pins being shown of  FIGS. 1-3 , and 
         FIG. 6  a schematic side view of a luggage box of an aircraft. 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       FIG. 1  shows an exemplary embodiment of a lock according to the invention, marked  10  in its entirety. The lock  10  is a catch lock. It comprises a catch  10 , in its entirety marked  20 , and a locking pin device (keeper) shown in  FIG. 5  and marked  30  in its entirety, with  FIG. 1  only showing two locking pins  32  and  32   b . The lock  10  is preferably intended for a luggage box  40  mounted overhead in a cabin of an aircraft, with a schematic side view being shown in the example of  FIG. 6 . 
     According to the illustration in  FIG. 6 , the luggage box  40  comprises a stationary housing  42 , which is mounted overhead in the cabin of an aircraft. The housing  42  comprises a lid  46  mobile about a rotary axis  44 . In the exemplary embodiment shown the lid  46  is a luggage bin or container opening downwards. The locking pin device  30  of the lock  10  is arranged at a lateral wall of the housing  42 . The catch  20  of the lock  10  is mounted at a lateral wall of the lid  46  adjacent to the lateral wall of the housing, namely such that when pivoting the lid  46  upwards, the catch  20  and the locking pin device  30  mutually engage each other. At an opposite end of the luggage box  40 , not shown, an identically embodied additional lock  10  is provided. The operation of the lock  10  occurs by a push button  48 , which is connected via cable pulls  50 , one of which being shown in  FIG. 4 , to the catch  20  of each lock  10 . When the lid  46  is pivoted upwards from the position shown in  FIG. 6 , in which the lock  10  is unlocked, the catch  20  and the locking pin  32 ,  32   b  of the locking pin device  30  engage each other, locking the lock  10 . By operating the push button  48  the lock is unlocked again, subsequently the lid  46  moves downwards under its own weight or loaded by luggage into the position shown in  FIG. 6 . 
     The catch  20  has a housing  21  made from fiberglass—reinforced thermoplastic, with its structure being best discernible in the exploded illustration of the catch  20  in  FIG. 4 . The catch  20  comprises two locking hooks  51 ,  51   b , each pivotal about a pivotal axis  22  and/or  22   b . The locking hooks  51 ,  51   b  each have an opening  55  and/or  55   b  for catching the locking pin  32  and/or  32   b . The locking pins  32 ,  32   b  are mounted parallel in reference to each other at a base plate  34  of the locking pin device  30 , as discernible in  FIG. 5 . The locking hooks  51 ,  51   b  are pivotal from the position shown in  FIG. 1 , in which the lock  10  is locked, into a position shown in  FIG. 2 , in which the lock  10  is unlocked, via a drive device marked  60  in its entirety. 
     The drive device  60  comprises a gear rack  62  and a sliding element  64 , arranged successively in a linear guide  66 . The linear guide  66  is formed by a channel provided in the housing  21 . In  FIG. 1  the right end of the channel forms a stop  68  for the gear rack  62 . The gear rack  62  and the sliding element  64  are pre-stressed in the direction towards a stop  68  by a spring element  70 , also arranged in the channel, so that it tends to assume the position shown in  FIG. 1 . 
     The locking hooks  51 ,  51   b  are connected via a knee lever  74  and/or  74   b  to the gear rack  62  and/or the sliding element  64 . The knee levers  74 ,  74   b  are each linked to the locking hook  51  and/or  51   b  next to their pivotal axis  22  and/or  22   b  at another pivotal axis  24  and/or  24   b . The knee levers  74 ,  74   b  are visible in their entirety in  FIG. 3  in the rear view of the lock  10 . In  FIG. 3  it is further discernible that the knee lever  74  is extended beyond the pivot point  24  to the locking hook  51  and embodied as a preliminary trigger lever to displace the gear rack  62 . The function of the preliminary trigger lever is explained in greater detail in the following. 
     The drive device  60  is completed by a gear wheel  80 , which engages gears  78  of the gear rack  62  and thus can be operated by one of the cable pulls  50  connected to the push button  48 . The gear wheel  80  converts the translational motion of the cable pull  50  into a translational motion of the gear rack  62  and the sliding element  64 . In the exploded illustration in  FIG. 4  additionally a lid  81  made from aluminum is allocated to the housing  21 , which is not shown in  FIGS. 1 and 2 . It covers the top of the linear guide  66  with the elements arranged therein and offers a counter bearing to the axes  22 / 22   b . The gear wheel  80  projects through a central slot  82  in the lid  81  and engages the teeth  89  of the gear rack  62 . When via the cable pull  50  a tensile force is applied upon the gear rack  80  it rotates, in  FIG. 4  in the clockwise direction, and moves the gear rack  62 , against the pressure of the spring element  70 , in the illustration in  FIG. 1  towards the left in the direction away from the stop  68 . The knee levers  74 ,  74   b  are each linked, at their end adjacent to the pivotal axis  24 , and/or  24   b  at the side facing away from the gear rack  80 , at a pivotal axis  26  and/or  26   b  with the sliding element  64  and/or the gear rack  68 , as best discernible in the rear view of the lock  10  in  FIG. 3 . The arrangement is made here such that the knee levers  74 ,  74   b  in the position shown in  FIG. 1 , in which the lock  10  is locked, can only be opened again by the impact of a force upon the link of the knee lever  74 ,  74   b  at the locking hook  51  and/or  51   b . The reason here is that in this position the knee levers  74 ,  74   b  each form, together with their corresponding locking hook  51  and/or  51 , a so-called positive locking or over-center position, from which they cannot be removed by the impact of a force from the openings  55 ,  55   b  of the locking hooks  51  and/or  51   b . This positive locking can only be released by displacing the gear rack  62  and the sliding element  64 , thus by rotating the gear wheel  80  or by operating an emergency operation lever  91  described in the following. In case of this displacement, at least the locking hook  51   b  is pivoted in the counter-clockwise direction into the position according to  FIG. 2 , in which the lock  10  is unlocked. 
     Due to the above-mentioned positive locking, the locking hooks  51 ,  51   b  are additionally locked mechanically in their closed position shown in  FIG. 1 , in order to prevent any opening by overload or external vibrations. This is achieved by the knee levers  74 ,  74   b  being moved beyond their dead center and are thus locked or blocked in their end position. The locking hooks  51 ,  51   b  can also be blocked by latches or blocking links, however the embodiment shown is a simpler solution with regards to design and mechanics, because latches or blocking links would require additional parts that are harder to operate under load. 
     The gear wheel  80  is supported rotational above the gear rack  62  at the housing  21 . For this purpose, at both sides of the guide  66 , two brackets  28 ,  29  extend upwards, each of which comprises a bearing bore, in which an axis of the gear wheel  80  is supported in a rotary fashion. 
     The gear rack  62  comprises, as best discernible in  FIG. 4 , an additional gearing  79 , which engages the gears  90  at the above-mentioned emergency operating lever  91 , supported pivotally at the housing  21 . 
     The two locking hooks  51 ,  5   b  are embodied identically. However, the locking pins  32 ,  32   b  have differently sized diameters Dg and/or Dk. The locking pin  32   b  therefore has play in the opening  55   b  in the locking hook  51   b  when the locking hook  51 ,  51   b  is in the position shown in  FIG. 1 , in which the lock  10  is locked. 
     Normally, the spring element  70  presses the gear rack  62  via the sliding element  64  to the stop  68 , so that the lock  10  is always locked as long as no pressure is applied upon the push button  48 . When the spring element  70  due to malfunction, for example a broken spring, cannot be able to do so, in order to lock the lock  10  the locking hook  51   b , allocated to the knee lever  74   b  embodied as a preliminary trigger lever, can be manually made to engage the locking pin  32   b  with the smaller diameter Dk with the help of the emergency operating lever  91  even when the other locking pin  32  no longer engages the locking hook  51  or can be made to engage it. As soon as the emergency operating lever  91  has brought the locking hook  51   b  into the position shown in  FIG. 1  the knee lever  74   b  is located in its position of positive locking from which it can only be removed by a renewed operation of the emergency operating lever  91  so that the lock  10  remains in the locked position even after an emergency manual locking. The emergency operating lever  91  can be operated via a narrow gap, which is located between the lateral wall of the lid  46  and the lateral wall of the housing  42 , using an object, such as a credit card or the like. 
     Normally, i.e. when no malfunction is given at the spring element  70  or at another part, which might prevent or hinder the proper operation of the lock  10 , the lock with the closed lid  46  of the luggage box  40  is situated in the position shown in  FIG. 1 . By pulling the cable pull  50 , due to an operation of the push button  48 , the gear wheel  80  is rotated in the clockwise direction in the illustrations of  FIGS. 1 and 2 . Thus, the gear rack  62  and with it the sliding element  64  is moved to the left against the pressure of the spring element  70  so that the locking hooks  51 ,  51   b  are pivoted in the counter-clockwise direction into the position shown in  FIG. 2 , in which the lock  10  is unlocked. As soon as the locking pin  32 ,  32   b  is released from the openings  55 ,  55   b  of the locking hooks  32 ,  32   b  the lid  46  moves downwards so that the luggage can be removed from the luggage box  40  or be inserted into said luggage box. When now the lid  46  is folded back upwards the upper left, free end of the knee lever  74   b  of  FIG. 1 , formed as a preliminary trigger lever, moves against the locking pin  32   b  and thus it is pivoted in the clockwise direction, thus moved into the housing  21 . Due to the fact that the locking pin  32   b  impinges the free end of the knee lever  24   b , first the positive locking is removed via the preliminary trigger lever. The locking hooks  51 ,  51   b  can be moved again in order to allow the lock  10  to snap shut. In  FIG. 3  it is discernible that the knee lever  74   b  here moves the gear rack  62  and the sliding element  64  in the direction away from the stop  68 , with here the spring element  70  being stressed. Here, the locking pins  32 ,  32   b  move along the locking hooks  51 ,  51   b , until they reach the openings  55 ,  55   b . As soon as they are positioned above the openings  55 ,  55   b  the locking hooks  51 ,  51   b  are pivoted by the pressure of the spring element  70  into the position shown in  FIG. 1 , in which the lock  10  is locked again. Here, the emergency operating lever  91  each time follows the motion of the gear rack  62 . 
     The catch  20  is dually latched at the locking pin device  30  during the locking of the lock  10 , namely a primary locking occurs between the locking hook  51  and the locking pin  32  with the help of the knee lever  74  and a secondary locking between the locking hook  51   b  and the locking pin  32   b  with the help of the knee lever  74   b . Neither the primary locking nor the secondary looking can be released by an impact of force upon the locking hooking  51 ,  51   b  because in the locking position the knee levers  74 ,  74   b  are respectively in positive locking, as explained above. 
     When the primary locking is blocked in the open position because a malfunction is given in the lock  10 , the lock  10  can still be fixed in the locked position by the knee levers  74   b  with the help of the secondary lock. When in case of a malfunction the locking occurs only via the locking hooks  51   b  and the locking pin  32 , due to the play between the locking hook  51   b  and the locking pin  32   b , the lid slightly projects from the luggage box  40  in the closed state, so that a malfunction is easily discernible from the outside. Due to the fact that the lid  46  is still safely locked the airplane may take off. 
     LIST OF REFERENCE CHARACTERS 
     
         
           10  Lock 
           20  Catch 
           21  Housing 
           22  Pivotal axis 
           22   b  Pivotal axis 
           24  Pivotal axis 
           24   b  Pivotal axis 
           26  Pivotal axis 
           26   b  Pivotal axis 
           28  Bracket 
           29  Bracket 
           30  Locking pin device 
           32  Locking pin 
           32   b  Locking pin 
           34  Base plate 
           40  Luggage box 
           42  Housing 
           44  Rotary axis 
           46  Lid 
           48  Push button 
           50  Cable pull 
           51  Locking hook 
           51   b  Locking hook 
           55  Opening 
           55   b  Opening 
           60  Drive device 
           62  Gear rack 
           64  Sliding element 
           66  Linear guide 
           68  Stop 
           70  Spring element 
           74  Knee lever 
           74   b  Knee lever 
           78  Gearing 
           79  Gearing 
           80  Gear wheel 
           81  Lid 
           82  Slot 
           90  Gearing 
           91  Emergency operating lever 
         Dg large diameter 
         Dk small diameter