Abstract:
A latch mechanism having a mounting bracket, a body portion, and a flange portion. The latch mechanism is used for connecting a first and second members. The body portion has walls extending from a flange portion defining a chamber therein. A detent mechanism is positioned in the chamber. A bolt, movably carried on the latch mechanism, has connected front and rear bolt portions and may include a spring biased ball for engaging a recess on the rear bolt in the latched position. A receptacle is defined in the mounting bracket. A head portion of the rear bolt is positioned relative to the receptacle in the latched position. A portion of the rear bolt travels through the receptacle when unlatching and engages the detent mechanism in the latched position. A gasket provided between the head and the receptacle seals the head in the receptacle in the latched position.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority under 35 U.S.C. §119 to copending U.S. Provisional Patent Application No. 61/431,117, filed Jan. 10, 2011. The disclosure set forth in the referenced application is incorporated herein by reference in its entirety. 
     
    
     BACKGROUND 
       [0002]    The present disclosure relates to a pressure relief latch mechanism for releasably latching and/or holding a first member in position with respect to a second member, and in particular to a latch mechanism including a bolt that is movable with respect to a mounting bracket from a latched condition to an unlatched condition in response to an over-pressure condition wherein the bolt is in sealed engagement with the mounting bracket of the latch mechanism when the bolt is in the latched condition and the bolt comprises a front bolt that is selectively coupled to a rear bolt. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWING FIGURES 
         [0003]      FIG. 1  is a perspective view of the latch mechanism shown in the latched condition. 
           [0004]      FIG. 2  is a perspective view of the latch mechanism shown in the unlatched condition. 
           [0005]      FIG. 3  is a top plan view of the latch mechanism shown in the latched condition. 
           [0006]      FIG. 4  is a side elevational view of the latch mechanism shown in the latched condition in solid lines and releasably latching a first member to a second member, and shown in the unlatched condition in dashed lines. 
           [0007]      FIG. 5  is an end view of the latch mechanism taken along line  5 - 5  of  FIG. 4  without showing the first member. 
           [0008]      FIG. 6  is a cross sectional view of the latch mechanism shown in the latched condition taken along line  6 - 6  of  FIG. 3 . 
           [0009]      FIG. 7  is a top perspective view of the mounting bracket of the latch mechanism. 
           [0010]      FIG. 8  is a bottom perspective view of the mounting bracket of the latch mechanism. 
           [0011]      FIG. 9  is a top plan view of the mounting bracket. 
           [0012]      FIG. 10  is a bottom view of the mounting bracket. 
           [0013]      FIG. 11  is a side elevational view of the mounting bracket. 
           [0014]      FIG. 12  is a cross sectional view of the mounting bracket taken along line  12 - 12  of  FIG. 9 . 
           [0015]      FIG. 13  is an end view of the mounting bracket taken along line  13 - 13  of  FIG. 11 . 
           [0016]      FIG. 14  is an end view of the mounting bracket taken along line  14 - 14  of  FIG. 11 . 
           [0017]      FIG. 15  is an enlarged view taken along line  15 - 15  of  FIG. 14 . 
           [0018]      FIG. 16  is a perspective view of the rear bolt of the bolt. 
           [0019]      FIG. 17  is a top plan view of the rear bolt. 
           [0020]      FIG. 18  is a left-side elevational view of the rear bolt. 
           [0021]      FIG. 19  is a front view of the rear bolt taken along line  19 - 19  of  FIG. 18 . 
           [0022]      FIG. 20  is a right-side elevational view of the rear bolt. 
           [0023]      FIG. 21  is a cross sectional view of the rear bolt taken along line  21 - 21  of  FIG. 17 . 
           [0024]      FIG. 22  is a perspective view of the front bolt of the bolt. 
           [0025]      FIG. 23  is a top plan view of the front bolt. 
           [0026]      FIG. 24  is a left-side elevational view of the front bolt. 
           [0027]      FIG. 25  is the front view of the front bolt taken along line  25 - 25  of  FIG. 24 . 
           [0028]      FIG. 26  is a cross sectional view of the front bolt taken along line  26 - 26  of  FIG. 25 . 
           [0029]      FIG. 27  is a top plan view of the sealing gasket. 
           [0030]      FIG. 28  is a cross sectional view of the sealing gasket taken along line  28 - 28  of  FIG. 27 . 
           [0031]      FIG. 29  is a side elevational view of the sealing gasket. 
           [0032]      FIG. 30  is a perspective view of the plunger of the biasing mechanism. 
           [0033]      FIG. 31  is a side elevational view of the plunger. 
           [0034]      FIG. 32  is a front view of the plunger. 
           [0035]      FIG. 33  is a top plan view of the detent member. 
           [0036]      FIG. 34  is a side elevational view of the detent member. 
       
    
    
     DETAILED DESCRIPTION 
       [0037]    As shown in the drawing figures, latch mechanism  10  is adapted to releasably latch a first member  12  to a second member  14 . First member  12  includes a first surface  16 , a second surface  18  and an aperture  20  that extends through first member  12  from first surface  16  to second surface  18 . Second member  14  includes a first surface  22  and a second surface  24 . Second member  14  may be, for example, an aircraft frame, aircraft engine cowling, or other body member. First member  12  may be, for example, a door or panel that is adapted to be coupled to second member  14  and that is adapted to be removed or displaced with respect to second member  14 . First member  12  may be latched in fluid-tight sealing engagement with second member  14 . 
         [0038]    Latch mechanism  10  includes a mounting bracket  30  that extends between a first end  32  and a second end  34 . Mounting bracket  30  includes a pair of generally planar side walls  36  that are spaced apart and generally parallel to one another. A generally planar bottom wall  38  extends between the bottom ends of side walls  36  and is generally perpendicular to side walls  36 . A top wall  40  extends between the top ends of side walls  36  and is generally perpendicular to side walls  36 . Top wall  40  extends transversely outwardly beyond each side wall  36  to form flanges  42  that extend outwardly from each side wall  36 . Each flange  42  includes one or more apertures adapted to receive a fastener for use in attaching mounting bracket  30  in engagement with second surface  18  of first member  12  in alignment with aperture  20 . Top wall  40  includes a generally planar top surface  44 . Each side wall  36  extends between a first end  46  and a second end  48 . Second ends  48  of side walls  36  are spaced inwardly from second end  34  of mounting bracket  30  such that top wall  40  extends from first end  32  to second end  34  outwardly beyond second ends  48  of side walls  36 . 
         [0039]    An elongate generally cylindrical chamber  50  is formed in mounting bracket  30  between side walls  36 , bottom wall  38  and top wall  40 . Chamber  50  extends from an opening at first end  32  toward second end  34  of mounting bracket  30  generally concentrically about and along a central longitudinal axis  52 . Chamber  50  extends from first end  32  of mounting bracket  30  to an end wall  54 . At least a portion of chamber  50  includes an internally threaded side wall  58  that extends into chamber  50  from first end  32  of mounting bracket  30 . End wall  54  extends generally transversely between side walls  36 , bottom wall  38  and top wall  40 . End wall  54  is located between first end  46  and second end  48  of side walls  36 . End wall  54  includes an aperture  56  in communication with chamber  50 . Aperture  56  may be in the general configuration of an obround, having two parallel sides and two generally semicircular ends. An aperture  60  extends through bottom wall  38  adjacent first end  32  of mounting bracket  30  and is in communication with chamber  50 . A pair of transversely spaced apart mounting ears  62  are attached to the bottom surface of top wall  40  and are located adjacent second end  34  of mounting bracket  30 . Each mounting ear  62  includes a generally circular aperture  64 . Apertures  64  of mounting ears  62  are coaxially aligned with one another about a pivot axis  66  that is transverse to longitudinal axis  52 . 
         [0040]    Mounting bracket  30  includes a receptacle  70  attached to top surface  44  of top wall  40 . Receptacle  70  includes a peripheral side wall  72  that extends upwardly from top surface  44  of top wall  40  to a generally circular rim  74 . Side wall  72  includes a generally circular outer surface  76  and a generally D-shaped inner surface  78  comprising a generally linear surface portion and a generally circular surface portion. The generally linear surface portion of inner surface  78  extends generally perpendicular to longitudinal axis  52 . Receptacle  70  includes a generally D-shaped chamber  80  formed within inner surface  78 . Top wall  40  forms a bottom wall  81  of chamber  80 . Bottom wall  81  of chamber  80  includes an aperture  82  in communication with chamber  80  that extends through top wall  40 . 
         [0041]    Latch mechanism  10  includes a bolt  90  pivotally coupled to mounting bracket  30  by a shaft  92  that extends concentrically along pivot axis  66  and into apertures  64  of mounting ears  62 . As shown in FIGS.  1  and  3 - 6 , bolt  90  is in a retracted position with respect to mounting bracket  30  such that latch mechanism  10  is in a latched condition whereby latch mechanism  10  releasably latches first member  12  to second member  14 . Bolt  90  is pivotal with respect to mounting bracket  30  about pivot axis  66  from the retracted position as shown in  FIG. 1  and in solid lines in  FIG. 4  toward an extended position as shown in  FIG. 2  and in dashed lines in  FIG. 4 , wherein latch mechanism  10  is in the unlatched condition and first member  12  may be removed from, or displaced with respect to, second member  14 . 
         [0042]    Bolt  90  may comprise a rear bolt  94  as shown in  FIG. 16  and a front bolt  96  as shown in  FIG. 22  which is removably coupled to rear bolt  94 . Rear bolt  94  includes a curved arm  98  extending between a first end  100  and a second end  102 . Arm  98  extends through aperture  82  in mounting bracket  30 . Arm  98  includes a convexly curved outer surface  104  that extends between first end  100  and second end  102 . A recess or detent  106  is formed in outer surface  104  adjacent second end  102  of arm  98 . Outer surface  104  of arm  98  conforms generally to one or more arcs of a circle between first end  100  of arm  98  and detent  106 . 
         [0043]    Rear bolt  94  of bolt  90  includes a head  110 , generally in the form of a planar plate, attached to second end  102  of arm  98 . As shown in  FIG. 17 , head  110  has a generally D-shaped peripheral edge  112  adapted to generally conform with the D-shaped inner surface  78  of receptacle  70 . Head  110  includes a generally planar bottom surface  114  and a spaced apart and generally parallel planar top surface  116 . Head  110  is adapted to be located within chamber  80  of receptacle  70  when bolt  90  is in the retracted position and the latch mechanism  10  is in the latched condition. An elongate slot  118  extends downwardly from top surface  116  of head  110  through head  110  and into second end  102  of arm  98 . Slot  118  is adapted to receive the tip of tool or implement, such as a screw driver, that may be used to selectively pivot bolt  90  with respect to mounting bracket  30 . 
         [0044]    Rear bolt  94  also includes a leg  120  that extends from a first end  122  to a second end  124 . Second end  124  of leg  122  is attached to first end  100  of arm  98 . Leg  120  extends generally transverse to the plane containing head  110 . First end  122  of leg  120  includes an aperture  126  adapted to receive shaft  92  such that pivot axis  66  extends concentrically through aperture  126 . Shaft  92  pivotally couples rear bolt  94  to mounting bracket  30 . Leg  120  includes a front wall  128  having a generally planar top surface  130  and a generally planar bottom surface  132  located generally coplanar with one another. Front wall  128  includes a generally rectangular projection  134  that extends outwardly from top surface  130  and bottom surface  132 . Projection  134  is located between top surface  130  and bottom surface  132 . Projection  134  includes a generally planar front surface  136  that is generally parallel to top surface  130  and bottom surface  132 , and an upper surface  138  and a lower surface  140  that are generally planar and spaced apart and parallel to one another. Upper surface  138  extends generally perpendicular to and between front surface  136  and top surface  130 , and lower surface  140  extends generally perpendicular to and between front surface  136  and bottom surface  132 . A threaded bore  142  having a central axis  144  extends through front surface  136  of projection  134  and through leg  120 . 
         [0045]    Front bolt  96  of bolt  90  extends from a first end  148  to a second end  150 . Front bolt  96  includes a pair of spaced apart and generally parallel and planar side walls  152  that extend from first end  148  to second end  150 . Front bolt  96  includes a rear wall  154  having a generally rectangular recess or slot  156  that extends transversely between side walls  152 . Slot  156  is adapted to matingly receive projection  134  of front wall  128  of rear bolt  94 . Slot  156  includes a generally planar rear surface  158  adapted to engage front surface  136  of projection  134  of rear bolt  94 , a generally planar upper surface  160  and a spaced apart and generally parallel lower surface  162  that extend generally perpendicular to rear surface  158 . Upper surface  160  is adapted to be located closely adjacent to upper surface  138  of projection  134  and lower surface  162  is adapted to be located closely adjacent to lower surface  140  of projection  134 . Rear wall  154  also includes a generally planar top surface  164  and a generally planar bottom surface  166  that are generally coplanar with one another and generally parallel to rear surface  158 . Top surface  164  and bottom surface  166  are located on opposite sides of slot  156 . Top surface  164  is adapted to be located closely adjacent to, or in engagement with, top surface  130  of rear bolt  94  and bottom surface  166  is adapted to be located closely adjacent to, or in engagement with, bottom surface  132  of rear bolt  94 . If desired, the projection  134  may alternatively be located on rear wall  154  of front bolt  96  and slot  156  may alternatively be located in front wall  128  of rear bolt  94 . 
         [0046]    Second end  150  of front bolt  96  includes an engagement member  170  having a tip  172  adapted to engage second surface  24  of second member  14  when latch mechanism  10  is in the latched condition. Front bolt  96  also includes an inclined front wall  174 . A bore  176  extends through front bolt  96  from front wall  174  to rear surface  158  of slot  156  concentrically about a generally linear axis  178 . Axis  178  is aligned generally coaxially with axis  144  of rear bolt  94 . Bore  176  includes a first bore portion  180  that extends inwardly from rear surface  158  of slot  156 . First bore portion  180  has a first diameter generally equal to the diameter of bore  142  of rear bolt  94 . Bore  176  of front bolt  96  also includes a second bore portion  182  that extends from the internal end of first bore portion  180  to front wall  174 . Second bore portion  182  has a second diameter which is larger than the first diameter of first bore portion  180 . First bore portion  180  and second bore portion  182  are concentrically located about axis  178 . A generally annular ledge  184  is formed between first bore portion  180  and second bore portion  182 . Apertures  186 A and  186 B extend from respective side walls  152  to second bore portion  182  and are generally coaxially aligned with one another. Front bolt  96  includes a pair of stop members  188 , such as lugs. Each stop member  188  extends outwardly from a respective side wall  152  and is located adjacent first end  148  of front bolt  96  and adjacent a bottom end of front bolt  96 . 
         [0047]    As shown in  FIG. 6 , front bolt  96  is removably coupled to rear bolt  94 . Projection  134  of rear bolt  94  is located within slot  156  of front bolt  96 , such that front bolt  96  is interlocked with rear bolt  94 . A threaded fastener  192 , such as a bolt, removably couples front bolt  96  to rear bolt  94 . Fastener  192  includes a threaded generally cylindrical shaft  194  adapted to extend closely within first bore portion  180  of front bolt  96  and to threadably engage bore  142  of rear bolt  94 . A head  196  is attached to shaft  194 . Head  196  has a diameter that is larger than the diameter of shaft  194  and is adapted to be closely received within second bore portion  182  of front bolt  96 . Head  196  of fastener  192  is adapted to engage ledge  184  of front bolt  96  such that threaded fastener  192  presses front bolt  96  into engagement with rear bolt  94  along axis  178  when threaded fastener  192  is tightened. Front bolt  96  is thereby securely coupled to rear bolt  94 , while allowing for the removal and replacement of front bolt  96  from rear bolt  94 . Front bolt  96  may be removed from rear bolt  94  for repair or replacement by loosening and unscrewing fastener  192  from rear bolt  94 . If desired, a lock wire  198  may removably couple fastener  192  to front bolt  96  to prevent unintended rotation and loosening of fastener  192 . Lock wire  198  may be connected to front bolt  96  through apertures  186 A-B. In addition to allowing for the removal of the front bolt  96  for repair or replacement, different types of front bolts  96  with respectively different types of engagement members  170  may be selectively coupled to rear bolt  94  as conditions may require. 
         [0048]    Latch mechanism  10  includes a resilient and flexible seal member such as a gasket  210  as shown in  FIGS. 27-29 . Gasket  210  is generally D-shaped and is configured to fit within chamber  80  of receptacle  70 . Gasket  210  is generally annular and includes a generally D-shaped central aperture  212  which is adapted to align with aperture  82  in the bottom wall  81  of receptacle  70  such that arm  98  of rear bolt  94  extends through aperture  82  of receptacle  70  and aperture  212  of gasket  210 . Gasket  210  includes a bottom end  214  adapted to sealingly engage the bottom wall  81  of receptacle  70  and a top end  216  adapted to sealingly engage bottom surface  114  of head  110  of bolt  90  when bolt  90  is in the retracted position, and latch mechanism  10  is in the latched condition. Top end  216  of gasket  210  may include a generally planar peripheral surface adapted to engage bottom surface  114  of head  110 . Bottom end  214  of gasket  210  includes a generally annular groove  218  forming a peripheral outer rim  220  and a peripheral inner web  222 . The top surface of top end  216  of gasket  210  is pressed into sealingly engagement with bottom surface  114  of head  110  of bolt  90 , and rim  220  and web  222  of bottom end  214  of gasket  210  are pressed into sealingly engagement with bottom wall  81  of receptacle  70 , when bolt  90  is in the retracted position and latch mechanism  10  is the latched condition, such that gasket  210  creates a fluid-tight seal between mounting bracket  30  and bolt  90  and around aperture  82  of receptacle  70 . 
         [0049]    Latch mechanism  10  includes a detent mechanism  230 . Detent mechanism  230  includes a detent member  232 . Detent member  232 , as shown in  FIGS. 33 and 34 , may comprise a generally cylindrical roller having a generally cylindrical center shaft and generally hemispherical shaped ends, or alternatively generally planar ends. In addition, detent member  232  may alternatively comprise a generally spherical ball. Detent member  232  is preferably formed from metal. Detent mechanism  230  includes an adjustable biasing mechanism  234  for providing a selectively adjustable and resilient biasing force to detent member  232 . 
         [0050]    As shown in  FIG. 6 , biasing mechanism  234  additionally comprises a resilient biasing member  236 , such as a helical coil spring, a plunger  238 , and a adjustable base member  240 . Biasing mechanism  234  is located within chamber  50  of mounting bracket  30 . Biasing member  236  extends between a first end  242  and a second end  244  generally concentrically along axis  52 . Plunger  238  includes a head  246  having a generally V-shaped recess  248  configured to receive a portion of detent member  232 . Plunger  238  also includes a generally cylindrical stem  250  extending from head  246  along axis  52 . Stem  250  extends within second end  244  of biasing member  236  such that second end  244  engages head  246 . Base member  240  includes a head  252  and a stem  254  that extends within first end  242  of biasing member  236 . First end  242  of biasing member  236  engages head  252 . Biasing member  236  resiliently biases plunger  238  into engagement with detent member  232  and thereby resiliently biases detent member  232  along axis  52  toward arm  98  of bolt  90  and into detent  106  of arm  98  as shown in  FIG. 6 . 
         [0051]    The outer circumferential surface of head  252  of base member  240  threadably engages threads in chamber  50  of mounting bracket  30  such that selective rotation of base member  240  about axis  52  moves base member  240  along axis  52  in a desired direction to either compress or expand biasing member  236  to a desired extent such that biasing member  236  applies a desired resilient biasing force to detent member  232  for engagement with detent  106 . When base member  240  is properly positioned and biasing member  236  is compressed as desired, the threads of head  252  may be deformed through aperture  60  to prevent further rotation of base member  240  with respect to mounting bracket  30 . 
         [0052]    When detent member  232  is in an extended position as shown in  FIG. 6 , a portion of detent member  232  projects outwardly from aperture  56  of end wall  54  of mounting bracket  30  and is located within detent  106  of arm  98  of bolt  90  to inhibit pivotal movement of bolt  90  about axis  66  with respect to mounting bracket  30 . Detent member  232  thereby releasably locks bolt  90  to mounting bracket  30  in the retracted position such that first member  12  is securely coupled to second member  14 . However, when a sufficiently large force is applied to engagement member  170  of bolt  90  in a generally downward direction as viewed in  FIG. 6 , the retention force with which biasing member  236  presses detent member  232  into detent  106  of bolt  90  may be overcome such that arm  98  of bolt  90  presses detent member  232  toward base member  240  to a retracted position and compresses biasing member  236 , such that bolt  90  may rotate in a generally clockwise direction about pivot axis  66  with respect to mounting bracket  30 . When detent member  232  is no longer located within detent  106 , bolt  90  may easily pivot about pivot axis  66  with respect to mounting bracket  30  to a retracted position as shown in  FIG. 2  wherein stop members  188  engage second ends  48  of side walls  36  and first member  12  is released from second member  14 . Outer surface  104  of arm  98  slides along detent member  232  as bolt  90  pivots about axis  66  between the retracted position shown in  FIG. 6  and the extended position as shown in  FIG. 2 . Bolt  90  may be manually returned to the retracted position as shown in  FIG. 6  by pressing downwardly on head  110  of bolt  90  to pivot bolt  90  in a counter-clockwise direction about axis  66  with respect to mounting bracket  30  until detent member  232  is located within detent  106  of bolt  90 . 
         [0053]    In the event an excess-pressure condition is encountered, wherein an excess pressure of a predetermined pressure is applied to second surface  18  of first member  12 , which results in a predetermined excess force being applied to engagement member  170  of bolt  90 , the excess force will overcome the force by which detent member  232  engages arm  98  of bolt  90  such that arm  98  of bolt  90  will move detent member  232  along axis  52  in a direction away from bolt  90  and toward base member  240 . Bolt  90  will then be free to pivot in a generally clockwise direction about axis  66  with respect to mounting bracket  30  toward an extended position as shown in  FIG. 2 , whereby engagement member  170  is released from second member  14 . Arm  98  of bolt  90  extends and passes through aperture  82  of receptacle  70  as bolt  90  pivots in a clockwise direction about axis  66  with respect to mounting bracket  30 . First member  12  may thereby be automatically removed from, or repositioned with respect to, second member  14  as a result of the excess-pressure condition, preventing or reducing damage that may otherwise be caused to first member  12  and second member  14 . Bolt  90  may be manually reset to the retracted position with respect to mounting bracket  30  by pressing downwardly on head  110  of bolt  90 .