Abstract:
What is disclosed is a latch comprising a housing and a pawl that is held in a normal position relative to the housing and capable of extending from the normal position and away from the latch housing along a travel path to maintain connection between the latch and a strike. This improved latch is a locking mechanism that reacts to deflections and bowing in overhead storage compartment bins found in airplanes to maintain positive engagement between the compartment door and bin. In addition, the latch is compatible with existing strikes used in storage compartment bins, and thus does not require existing strikes to be modified or changed for the latch to preserve engagement between the compartment door and bin.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates generally to the field of locking mechanisms; more specifically, a door locking mechanism for an aircraft overhead storage bin.  
         BACKGROUND OF THE INVENTION  
         [0002]    One issue that exists in aircraft manufacture is the development of a locking mechanism that does not lose connection when an overhead storage compartment deflects or bows. To maximize storage capacity, overhead storage compartments are increasingly designed with longer bays to accommodate aircraft passengers&#39; demand for more space to store their carry-on luggage. As a result, fewer vertical supports are used to hold the storage compartments in position, which make the compartments subject to a higher likelihood of deflection and bowing. The bowing in a storage compartment is caused by the weight of the compartment&#39;s contents as well as moments of stress during times of turbulence and landing.  
         DESCRIPTION OF THE RELATED ART  
         [0003]    One attempt of solving this issue has been to provide a strike with an extending arm that is rotatably fixed to the overhead storage compartment bin. The arm of this strike can pivot around its fixed point and be flexible enough to accommodate the deflections and bowing in the storage compartment bins. However, this design has the limitation of requiring a modified latch design to accommodate this flexible strike with a rotatable fixed arm. Thus, to incorporate this strike design in airplanes would require the added expense of changing storage compartment latches as well as strikes.  
           [0004]    Therefore, a locking mechanism is needed that reacts to deflections and bowing in overhead storage compartment bins to maintain positive engagement between the compartment door and bin. Preferably, the locking mechanism could function without requiring a change or modification in both the strike and latch of existing locking mechanisms for overhead storage compartments.  
         SUMMARY OF THE INVENTION  
         [0005]    The present invention provides a locking mechanism designed to maintain connection and overcome forces that disturb connection between the door and bin of an overhead storage compartment found in airplanes. The locking mechanism improves the latch of existing designs to include an extendable pawl that reacts to the deflections and bowing in overhead storage compartment bins to maintain positive engagement between the pawl and a strike on the bin. This improved latch is compatible with existing strikes used in storage compartment bins and thus, utilizing this improved latch does not require that existing strikes be modified or changed.  
           [0006]    In one embodiment, the latch comprises a housing, a handle rotatably fixed to the housing, an extendable pawl having an angled tip, and a link that connects the handle to the extendable pawl. The extendable pawl is held in a catched position relative to the housing by a catch that is rotatably fixed to the housing. When the door is closed the catch rotates away from the tip of the pawl, the pawl is free to extend from the catched position and away from the housing to follow the movements of a deflecting and bowing bin.  
           [0007]    The latch preferably includes a track cover encased within the housing that provides a surface from which the pawl may travel and extend from the housing to follow the movements of and slide along the travel path of a deflecting and bowing bin.  
           [0008]    In a preferred embodiment, an angled tip of the extendable pawl has a notch to receive the catch. While the notch is not mandatory to keep the storage compartment door in a closed position, the notch assists the pawl in maintaining positive engagement with the strike of a deflecting and bowing storage compartment bin.  
           [0009]    In a preferred embodiment, the extendable pawl is connected to the handle of the latch by a link with two arms that are rotatably joined at a point, wherein one arm is connected to the pawl and the other arm is connected to the handle. The link with the two arms allows for the handle to remain flush to the front portion of the housing when the pawl retracts from its catched position into the housing. This allows a person to close a storage compartment door by pressing the handle in the down position as the door engages with the bin. Alternatively, the link allows the pawl to force the handle up away from the housing when the pawl retracts from its catched position. This provides a warning to the airplane&#39;s occupants that the storage compartment door is not fully engaged with the bin.  
           [0010]    The pawl preferably has at least one roller, which advantageously assists the pawl when it extends or retracts from a normal latched or catched position.  
           [0011]    Although this latch was designed for use in aircrafts, the practicality of the design allows for the latch to be used in a number of arrangements, such as but not limited to storage compartments found in buildings or naval vessels.  
           [0012]    And although this summary of the claimed invention provides an idea of what is covered, the invention will be more readily apparent from the following description and appended claims when taken with the drawings. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0013]    [0013]FIG. 1 shows an expanded view of the internal components of the preferred embodiment of the overhead storage bin lock of the invention.  
         [0014]    [0014]FIG. 1A shows an expanded view of the components linking the catch with the track cover.  
         [0015]    [0015]FIG. 1B shows an expanded view of the free-travel link connecting the handle with the pawl.  
         [0016]    [0016]FIG. 2 is an isometric view of the preferred embodiment without the back portion of the housing showing the extendable pawl held in a catched position with respect to the latch housing.  
         [0017]    [0017]FIG. 2A is a cross section of the embodiment in FIG. 2, along line  2 - 2 .  
         [0018]    [0018]FIG. 3 is another view of the embodiment in FIG. 2A showing the strike in contact with the pawl causing the pawl to retract into the housing and forcing the handle outward to an unflush position relative to the face of the housing.  
         [0019]    [0019]FIG. 4 is another view of the embodiment in FIGS. 2A and 3 showing the compartment door in a closed position with respect to the compartment bin where the extendable pawl is engaged with the strike.  
         [0020]    [0020]FIG. 5 is an isometric view of the embodiment in FIGS.  2 A- 4  showing the compartment bin in an undeflected normal position.  
         [0021]    [0021]FIG. 6 is another view of the embodiment in FIG. 5 showing the compartment bin in a deflected position with the spring-loaded pawl extended to maintain positive engagement with the strike.  
         [0022]    [0022]FIG. 7 is a side profile view of the embodiment in FIGS.  2 A- 4  showing the spring-loaded pawl extended from its normal position to maintain positive engagement with the strike of a deflecting and bowing compartment bin. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0023]    The overhead storage bin lock is designed to compensate for the deflection and bowing in an overhead storage bin to maintain positive engagement. As one may recognize, the overhead storage bin lock could be used to maintain connection with any two objects that could move in opposing directions and is not necessarily limited to overhead storage compartments found on airplanes.  
         [0024]    [0024]FIG. 1 illustrates the preferred embodiment of the latch  101 , which includes a housing having a front portion  102  and a back portion  103 , which are connected together by a plurality of housing screws  104 . Encased within the housing are an extendable pawl  105 , a track cover  106 , a catch  107 , and a handle  108 .  
         [0025]    Associated with the extendable pawl  105  are three rollers  109 , each mounted on a pin  110  that can be fed through a hole in the pawl and fastened by a nut  111 . The rollers  109  are connected to the extendable pawl  105  in a manner such that they are in contact with a track for the pawl to travel on. The track is a surface formed between two sets Of grooves  112  found on one side of the back portion of the housing  103  and one side of the track cover  106 .  
         [0026]    The grooves  112  are shaped and sized in a manner to house two compression springs  113 . The grooves  112  span the full length of the springs  113  and provide for a travel path for the springs to compress and recoil.  
         [0027]    The extendable pawl  105  has two wings  114 , which are perpendicular to the length of the pawl  105  as shown in more detail on FIG. 1B. Each wing  114  is designed to engage with one end of a compression spring  113 . The wings  114  also provide a platform by which the springs  113  may channel a force to the pawl  105 , and assist in creating and maintaining positive engagement between the pawl and a strike found on an overhead storage compartment.  
         [0028]    The track cover  106  is fastened to the back portion of the housing  103  by a plurality of track cover screws  115 . The fastening of the track cover  106  to the back portion of the housing  103  creates a casing that contains the extendable pawl  105 , provides the track by which the rollers  109  may travel, and captures the compression springs  113 .  
         [0029]    The catch  107  is rotatably fixed to the track cover  106 . As shown in greater detail on FIG. 1A, the track cover  106  has four lugs  117  that are perpendicular to and extend from the track cover. The catch  107  has two arms; each sized to fit between two of the lugs  117  and fixed together with pins  116 , which also extend through the springs  125 . The catch  107  is biased by the springs  125  toward the pawl  105 , but is capable of rotating about the pins  116  and away from the pawl.  
         [0030]    The handle  108  is rotatably fixed to the back portion of the housing  103 . The handle  108  has four arms  119 . The back portion of the housing  103  has two members  118  that are perpendicular to and extend from the back portion of the housing. Each member  118  is sized to fit between two of the arms  119 . The handle  108  is connected to the back portion of the housing  103  by inserting the pin  121  through holes in the arms  119 , members  118 , and through the spring  120 . The handle  108  is biased by the spring  120  toward a flush position with the face of the housing, as seen in FIG. 2A, but is able to rotate about the handle pin  121  and away from the housing, as seen in FIG. 3.  
         [0031]    As shown in more detail in FIG. 1B, the pawl  105  is connected to the handle  108  by a free-travel link  122  comprised of two arms  123 ,  124  that are connected on one end by a pin  128  and may rotate about the pin. Disposed between the connection and on pin  128  is a torsion spring  129 . Spring  129  holds the two arms  123  and  124  in an orientation causing a connection pin  127 , that connects arm  123  with the pawl  105 , to rest along the smooth surface of a slot  133  in the pawl  105  and away from the notches  126 , in the slot, when the handle is in a flush position with the housing. This orientation provides a connection between the pawl and arm  123  that allows the pawl to freely extend from the housing without interference from the link  122 .  
         [0032]    The other arm  124  is connected to the handle  108  by a pin  132  and a plurality of e-rings  130 . Disposed between the connection along the pin  132  is a spring  131  that is connected to arm  123 . The spring  131  works with spring  129  causing the arms  123 ,  124  to be biased toward maintaining a specific orientation and away from rotating about pin  128 . If the arms are forced to rotate about pin  128 , the springs  129 ,  131  provide a sufficient force to urge the arms to recoil back to the specific orientation once the force, which caused the arms to rotate, is removed.  
         [0033]    The arms  123 ,  124  are connected to the pawl  105  and the handle  108 , respectively, such that when the handle  108  is lifted, the free-travel link  122  catches onto one of the notches  126  and draws the pawl  105  into the housing.  
         [0034]    As seen in FIG. 2, the components of the preferred embodiment are connected, without the back portion of the housing  103 , with the pawl  105  being held in its catched position by catch  107 .  
         [0035]    When the compartment door  201  is swung toward an overhead storage bin  302 , as shown in FIG. 3, the pawl  105  comes in contact with a strike  301  on the bottom wall of the bin  302  causing the pawl to retract into the housing of the latch  101  and away from the catch  107 . The rollers  109  assist the pawl as it slides into the housing. As the pawl retracts into the housing, however, the springs  113  are further compressed. The catch is then forced from its engagement with the pawl when the strike  301  hits the catch. The catch is urged by the strike to rotate away from the pawl so that the strike may engage with the pawl as seen in FIG. 4.  
         [0036]    The front face of the handle  303  is normally flush with the front of the latch  304  as seen in FIG. 2A. However, when the strike  301  hits the pawl  105 , forcing the pawl  105  into the housing, the free-travel link  122  forces the handle  108  to rotate away from the housing, as seen in FIG. 3, such that the top portion of the handle  303  is no longer flush with the front face of the housing  304 . As the pawl  105  engages with the strike  301  to a latched position, as seen in FIG. 4, the springs  113  recoil and the handle  108  rotates to where the top portion of the latch handle  303  is again flush with the front face of the latch housing  304 .  
         [0037]    If the pawl  105  and strike  301  are not fully engaged, as shown in FIG. 3, the front face of the handle  303  will have a tendency to be in an unflush position with the front face of the latch housing  304 . The position of the front face of the handle  303  provides a signal as to whether the compartment door  201  is completely closed and connected with the compartment bin  302 .  
         [0038]    The two arms  123 ,  124  of the free-travel link  122  are capable of rotating about its connection pin  128  to allow the pawl  103  to come into contact and engage with the strike  301  without requiring the latch handle  108  to rotate. Thus, the front face of the latch handle  303  is able to maintain its flush position with the front face of the latch  304  when the pawl  103  comes in contact with the strike  301 . The two arms  123 ,  124  of the free-travel link  122  advantageously allow the compartment door  201  to fully close and to engage with the compartment bin  302  even if there is an obstruction, such as a person&#39;s hand, which prevents the handle  108  from rotating away from the latch housing.  
         [0039]    The pawl  105  may be disengaged from the strike  301  by lifting the handle  108  up and rotating it about pin  121  so that the face of the handle  303  is in an unflush position. When the handle is lifted, the arm  123  catches one of the notches  126 , along the pawl slot  133 , causing the pawl to disengage with the strike  301  while drawing the pawl into the housing. As the handle is lifted and the pawl is drawn into the housing, the catch  107  will be urged by spring  125  to engage with the pawl so that the pawl will be in a catched position as seen in FIGS. 2 and 2A.  
         [0040]    [0040]FIG. 5 is an isometric view of the preferred embodiment without the back portion of the housing  103  showing the storage bin  302  in an undeflected normal position. The pawl  105  is shown in positive engagement with the strike  301 . The rollers  109  of the pawl  105  are shown in contact with the track formed between the two grooves  112  on the track cover  106 . The compression springs  113  are shown partially contained within the grooves  112  of the track cover  106 .  
         [0041]    When the storage bin  302  deflects, as shown in FIG. 6, the pawl  105 , aided by the compression springs  113 , extend to maintain positive engagement with the strike  301 . The rollers  109  and the compression springs  113  work to reduce and provide additional force to overcome the friction force that the pawl  105  encounters along the length of the tract between the grooves  112 .  
         [0042]    Although the preferred embodiment has a pawl  105  with an angled end  501  having a notch  502  for assisting and providing positive engagement with the strike  301 , the notch  502  is not necessary for the pawl  105  to follow the movements of a deflecting bin  302 . The compression springs  113  of the preferred embodiment provide sufficient force to allow the pawl  105  to extend from the latch housing to maintain positive engagement with the strike  301  of a deflecting bin  302 .  
         [0043]    Additionally, while the preferred embodiment has rollers  109  connected to the pawl  105 , the rollers  109  are not necessary for the latch  101  to operate. The rollers  109  merely assist the pawl  105  to maintain engagement with the strike by reducing friction along the pawl&#39;s  105  travel path. The rollers  109  could be left out or could be easily replaced with a friction reducing strip or grease.  
         [0044]    [0044]FIG. 7 is a side profile view of the preferred embodiment in positive engagement with the strike  301  of a deflecting bin  302 . The pawl  105  is shown extended from its normal position and away from the latch housing with the latch handle  108  flush with the face of the latch housing. Even when the bin  302  is in a deflected position, the door latch  101  may be disengaged from the strike  301  on the bin. The pawl  105  may be disengaged from the strike by lifting the handle  108  up and rotating it about pin  121 . The link arm  123  will catch one of the notches  126  drawing the pawl into the housing and causing the pawl to disengage with the strike.  
         [0045]    Although the foregoing invention has been described in terms of certain preferred embodiments, other embodiments will become apparent to those of ordinary skill in the art, in view of the disclosure herein. Accordingly, the present invention is not intended to be limited by the recitation of preferred embodiments, but is instead to be defined solely by reference to the appended claims.