Abstract:
The invention relates to a hinge arrangement of a door ( 14 ) for closing off an opening, such as a housing opening, partition opening, wall opening, or the like, having at least one pivot pin ( 18   a ) that is connected to the door ( 14 ) and oriented vertically in the direction of the housing ( 22 ), wherein the pin can be engaged in a pivot pin receptacle ( 20   a ) on the housing ( 22 ). The pivot pin ( 18   a ) can be moved from a retracted position, in which the pivot pin ( 18   a ) is not engaged in the pivot pin receptacle ( 20   a ), by vertical displacement into an extended position in which the pivot pin ( 18   a ) is engaged in the pivot pin receptacle ( 20   a ) and is rotatably supported therein. A releasable, spring-loaded locking device ( 41 ) acts on the pivot pin ( 18   a ) and holds the pivot pin ( 18   a ) in the retracted position.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    This invention relates to a hinge arrangement of a door for shooting an opening such as a housing opening, partition opening, wall opening, or the like, having at least one pivot pin that is connected to the door, that points vertically toward the housing, and can be brought into engagement in a pivot pin receptacle in the housing. By sliding vertically, the pivot pin can be moved from a retracted position in which the pivot pin is not engaged in the pivot pin receptacle into an extended position in which the pivot pin is engaged and rotatably supported in the pivot pin receptacle. 
         [0003]    2. Discussion of Related Art 
         [0004]    German Patent Reference DE 10 2007 012 980.9 discloses a door arrangement in which the attachment side, such as the hinge side, can be switched in order to permit the door to open toward a different side. To permit the door to first be attached at will, first at the left and then at the right, the door is embodied with two attachment sides. In this case, each attachment side has a hinge, which through corresponding actuation of an actuating lever, can be brought into one position to form a hinge and into another position to form a latch. 
         [0005]    When functioning as a hinge, a pair of one pivot pin pointing vertically upward and one pivot pin pointing vertically downward engages in corresponding pivot pin receptacles in the housing. If the hinge or latch on an attachment side is to be opened, then through corresponding actuation of the actuating lever, the two pivot pins on the corresponding attachment side are retracted from the associated pivot pin receptacles so that the door can be opened on the attachment side. The hinge on the other attachment side remains closed in this case. 
         [0006]    If the door is open on one side and the actuating lever is actuated again in order to open the other attachment as well, this can lead to an unintended unhinging of the door, which can result in damage to the door if it is not held firmly. 
         [0007]    On the other hand, problems can arise when closing the door if unintentional actuation of the actuating lever causes the pivot pins to be brought into an extended position in which they protrude from the door. 
       SUMMARY OF THE INVENTION 
       [0008]    One object of this invention is to provide a hinge arrangement that assures a reliable function of the door provided with two attachment sides, even in the event of inadvertent actuation of the actuating lever and also prevents an unintended unhinging of the door. 
         [0009]    This object of this invention is attained by a hinge arrangement having characteristics defined in this specification and in the claims, including advantageous modifications of the door arrangement according to this invention. 
         [0010]    According to this invention, an unlockable spring-loaded locking device acts on the pivot pin, holding the pivot pin in the retracted position. As long as the pivot pin is secured in the retracted position, the actuating lever on the door cannot be brought into a position in which both attachment sides of the door are opened and the door can be unhinged. Thus, the door can only be unhinged when the locking device is released. 
         [0011]    Only when the locking device is released can the pivot pin move through a pivot pin passage on the door edge oriented toward the housing, moving in the direction toward the pivot pin receptacle aligned with the pivot pin passage. 
         [0012]    According to one preferred embodiment of this invention, a securing spring can exert its action between the door and the pivot pin, acting laterally on the pivot pin, sliding it laterally into the locked position of the locking device so that the vertical sliding direction of the pivot pin is oriented toward a region of the door adjacent to the pivot pin passage so that the pivot pin cannot travel through the pivot pin passage. This measure makes it possible to effectively avoid an unintended actuation when the door is open. 
         [0013]    The securing spring can be advantageously actuated in opposition to its prestressing direction, thus bringing the locking device into its unlocked position. The prestressing force of the spring keeps the locking device in its locked position. 
         [0014]    According to a particularly simply designed embodiment, the securing spring can be a metal spring element of a piece of sheet metal. 
         [0015]    In this case, the securing spring can have a through bore on the door interior, through which the pivot pin extends. This arrangement can be implemented simply and can assure a reliable function. 
         [0016]    In order to assure that when the door is closed, the locking device is unlocked and permits a movement of the pivot pin, the securing spring can protrude from the door in the direction toward the housing wall. When the door is closed, the securing spring is then actuated by the housing wall, thus bringing the locking device into its unlocked position. 
         [0017]    According to an alternative embodiment, the securing spring can be mounted to the outside of the door oriented toward the housing wall and can extend through an associated opening into the door interior. The securing spring then acts on the pivot pin inside the door. 
         [0018]    In order to enable an intentional unhinging of the door after it is open, once the door is opened, the securing spring can be manually actuated directly so that the locking device is brought into its unlocked position. 
         [0019]    A particularly effective and reliable locking device can be achieved if the securing spring is mounted to the door interior, on the side oriented toward the housing wall and is thus covered. On the housing wall, a pin is provided, which, when the door is closed, extends through an associated opening into the door interior and acts on the securing spring, thus bringing the locking device into its unlocked position. 
         [0020]    However, the covered placement when the door is opened can also be actuated in an entirely intentional fashion by inserting an actuating pin into the opening to manually actuate the securing spring, thus bringing the locking device into its unlocked position. 
         [0021]    According to a particularly functionally reliable embodiment, the pivot pin can be supported in a pin guide that is engaged by the securing spring. This assures that the pivot pin is particularly easy to slide. 
         [0022]    According to another embodiment that features a particularly simple design, the door can be acted on by a securing spring that covers the pivot pin passage in the locked position of the locking device so that the pivot pin cannot be inserted through the pivot pin passage. In this case, the securing spring can have a guide plate that can be moved perpendicular to the pivot pin passage through actuation of the securing spring. The guide plate can have a through bore that is aligned with the pivot pin passage when the locking device is unlocked, thus permitting an insertion of the pivot pin into the pivot pin receptacle in the housing. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0023]    This invention is explained in view of exemplary embodiments and with reference to the accompanying drawings, wherein: 
           [0024]      FIG. 1   a  is a schematic partial view of a door arrangement with two attachment sides in the “closed” actuation position; 
           [0025]      FIG. 1   b  is a schematic partial view of the door arrangement shown in  FIG. 1   a , in the actuation position for “opening the left attachment side”; 
           [0026]      FIG. 1   c  is a schematic partial view of the door arrangement shown in  FIGS. 1   a  and  1   b , in the actuation position for “opening the right attachment side”; 
           [0027]      FIG. 2  is a transparent, schematic front view of the side of the door panel oriented toward the user, with an arrangement of four actuating rods; 
           [0028]      FIG. 3  is a schematic, sectional side view of a closed door with a hinge arrangement in which the upper left pivot pin can be brought upward into engagement with the upper left pivot pin receptacle in the housing by being slid vertically, and a locking device, which has a securing spring composed of a piece of sheet metal mounted to the outside of the door, is in the unlocked position in which it acts laterally on the pivot pin; 
           [0029]      FIG. 4  is a schematic, sectional side view of the arrangement according to  FIG. 3 , in which the door is open and the locking device is locked; 
           [0030]      FIG. 5  is a schematic, sectional side view of the hinge arrangement according to  FIGS. 3 and 4  in which the door is open and the securing spring is manually actuated in order to unlock the locking device; 
           [0031]      FIG. 6  is a schematic, sectional side view of a closed door with a hinge arrangement in which the upper left pivot pin can be brought upward into engagement with the upper left pivot pin receptacle in the housing by being slid vertically, and a locking device, which has a securing spring composed of a piece of sheet metal mounted to the outside of the door, is in the unlocked position in which it uncovers the pivot pin passage at the top of the door; 
           [0032]      FIG. 7  is a schematic, sectional side view of the arrangement according to  FIG. 6 , and the door is open and the locking device is in the locked position in which the sheet metal element covers the pivot pin passage at the top of the door; 
           [0033]      FIG. 8  is a schematic, sectional side view of the hinge arrangement according to  FIGS. 6 and 7  in which the door is open and the securing spring is manually actuated in order to unlock the locking device by causing the sheet metal element to uncover the pivot pin passage at the top of the door; 
           [0034]      FIG. 9  is a schematic, sectional side view of a closed door with a hinge arrangement in which the upper left pivot pin can be brought upward into engagement with the upper left pivot pin receptacle in the housing by being slid vertically, and a locking device, which has a securing spring composed of a piece of sheet metal mounted to the inside of the door in a covered position, is in the unlocked position in which it uncovers the pivot pin passage at the top of the door; 
           [0035]      FIG. 10  is a schematic, sectional side view of the arrangement according to  FIG. 9 , and the door is open and the locking device is in the locked position in which the sheet metal element covers the pivot pin passage at the top of the door; 
           [0036]      FIG. 11  is a schematic, sectional side view of the hinge arrangement according to  FIGS. 9 and 10 , in which the door is open and the securing spring is manually actuated by an actuating pin in order to unlock the locking device by causing the sheet metal element to uncover the pivot pin passage at the top of the door; 
           [0037]      FIG. 12  is a schematic, sectional side view of a closed door with a hinge arrangement in which the upper left pivot pin can be brought upward into engagement with the upper left pivot pin receptacle in the housing by being slid vertically, and a locking device, which has a securing spring of a piece of sheet metal that is mounted on the inside of the door, is in the unlocked position in which it acts laterally on a pin guide in which the pivot pin is guided; and 
           [0038]      FIG. 13  is a schematic, sectional side view of the arrangement according to  FIG. 12 , in which the door is open and the locking device is locked. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0039]      FIG. 1   a  is a schematic partial view of a door arrangement for closing a housing opening. A door panel  14  made of sheet steel has a left hinge  16   a  on its left attachment side  12   a.    
         [0040]    The left hinge  16   a  has an upper left pivot pin  18   a  that is connected to the door panel  14  and points vertically upward, and the upper left pivot pin  18   a  is engaged in an upper left pivot pin receptacle  20   a  in the housing  22  and rotatably supported therein. 
         [0041]    The left hinge also has a lower left pivot pin  24   a  that is connected to the door panel  14  and points vertically downward, and the lower left pivot pin  24   a  is engaged in a lower left pivot pin receptacle  26   a  in the housing  22  and rotatably supported therein. 
         [0042]    The door panel  14  also has a right attachment side  12   b  on which a right hinge  16   b  is provided. The right hinge  16   b  has an upper right pivot pin  18   b  that is connected to the door panel  14  and points vertically upward. The upper right pivot pin  18   b  is engaged in an upper right pivot pin receptacle  20   b  in the housing  22  and rotatably supported therein. The right hinge  16   b  also has a lower right pivot pin  24   b  that is connected to the door panel  14  and points vertically downward. The lower right pivot pin  24   b  is engaged in a lower right pivot pin receptacle  26   b  in the housing  22  and rotatably supported therein. 
         [0043]    Adjacent to the door panel  14 , the housing  22  has housing parts  22   a  and  22   b  that extend perpendicular to the pivot pins  18   a ,  18   b ,  24   a ,  24   b  and contain pivot pin receptacles  20   a ,  20   b ,  26   a , and  26   b  in the form of circular recesses. The housing parts  22   a  and  22   b  extending perpendicular to the pivot pins  18   a ,  18   b ,  24   a ,  24   b  are of sheet metal and have pivot pin receptacles  20   a ,  20   b ,  26   a , and  26   b  in the form of bores. 
         [0044]    In its middle, the door panel  14  has an actuating element  28  that has an actuating handle  40  and is coupled to the left pivot pins  18   a ,  24   a  and the right pivot pins  18   b ,  24   b  and in  FIG. 1   a  is brought into the “closed” actuation position, such as position  1  (POS 1 ). 
         [0045]    In the “closed” actuation position  1  (POS 1 ), the left pivot pins  18   a  and  24   a  engage with the two left pivot pin receptacles  20   a  and  26   a  and the right pivot pins  18   b  and  24   b  engage with the two right pivot pin receptacles  20   b  and  26   b.    
         [0046]      FIG. 1   b  is a schematic partial view of a door arrangement in which the actuating element  28  is brought into the actuation position for “opening the left attachment side”, such as into position  2  (POS 2 ). In the actuation position for “opening the left attachment side” (POS 2 ), the left pivot pins  18   a  and  24   a  are disengaged from the left pivot pin receptacles  20   a  and  26   a  and the door panel  14  can pivot around the right hinge  16   b.    
         [0047]      FIG. 1   c  is a schematic partial view of a door arrangement in which the actuating element  28  is brought into the actuation position for “opening the right attachment side”, such as into position  3  (POS 3 ). In the actuation position for “opening the right attachment side” (POS 3 ), the right pivot pins  18   b  and  24   b  are disengaged from the right pivot pin receptacles  20   b  and  26   b  and the door panel  14  can pivot around the left hinge  16   a.    
         [0048]    As shown in  FIGS. 1   a  through  1   c , the left and right hinges  16   a  and  16   b  combine with the actuating element  28  to form a closing mechanism, which produces a hinge or a latch on one or both attachment sides  12   a  and  12   b  of the door panel  14 , depending on the actuation position POS 1 , POS 2 , or POS 3  of the actuating element  28 . 
         [0049]    The latch can be situated on a door, a wall, or a cover equipped with a mechanism that has at least the three actuating positions POS 1 , POS 2 , or POS  3 . 
         [0050]      FIG. 2  is a schematic front view of the side of the door panel  14  oriented toward the user, with an arrangement of four actuating rods  30   a ,  30   b ,  32   a , and  32   b , that are attached at one end  30   ab ,  30   bb ,  32   ab ,  32   bb  to the end region of the pivot pins  18   a ,  18   b ,  24   a ,  24   b  oriented away from the associated pivot pin receptacles  20   a ,  20   b ,  26   a ,  26   b.    
         [0051]    With their other ends  30   aa ,  30   ba ,  32   aa ,  32   ba , the actuating rods  30   a ,  30   b ,  32   a , and  32   b  are pivotably supported on the lever arm H. The actuating rods  30   a ,  30   b ,  32   a ,  32   b  are of metal that is integrally joined to the pivot pins  18   a ,  18   b ,  24   a ,  24   b.    
         [0052]    In an alternative embodiment, not shown, the pivot pins  18   a ,  18   b ,  24   a ,  24   b  can also be actuated by a system of cables. 
         [0053]    The actuating element  28  has a disk  38  that can be rotated around the axle A. The ends  30   aa ,  30   ba ,  32   aa ,  32   ba  of the actuating rods  30   a ,  30   b ,  32   a ,  32   b  oriented away from the pivot pins  18   a ,  18   b ,  24   a ,  24   b  engage the disk  38  at respective bearing points L 1 , L 2 , L 3 , L 4  spaced apart from the axle A by a distance that corresponds to the lever arm H. The rotatable disk  38  is positioned on the side of the door panel  14  oriented away from the user and parallel to the door panel  14 . The axle A connected to the rotatable disk  38  extends through the door panel  14  toward the user. At the end oriented toward the user, the actuating element  28  has an actuating handle  40 , as shown, for example, in  FIGS. 1   a  through  1   c.    
         [0054]    Depending on the rotation direction of the actuating element  28  and the disk  38 , two of the four actuating rods  30   a ,  30   b ,  32   a , and  32   b  arranged on the door are always actuated so that one side opens and the other side remains closed. With this design, a door can thus be selectively opened at either the right or left side. 
         [0055]    In the “closed” actuation position (POS 1 ), the left pivot pins  18   a  and  24   a  are fully engaged with the two left pivot pin receptacles  20   a  and  26   a  while the right pivot pins  18   b  and  24   b  are fully engaged with the two right pivot pin receptacles  20   b  and  26   b.    
         [0056]    In the actuation position for “opening the left attachment side” (POS 2 ), the left pivot pins  18   a  and  24   a  are fully disengaged from the left pivot pin receptacles  20   a  and  26   a.    
         [0057]    In the actuation position for “opening the right attachment side” (POS 3 ), the right pivot pins  18   b  and  24   b  are fully disengaged from the right pivot pin receptacles  20   b  and  26   b.    
         [0058]    As shown in  FIG. 2 , the bearing points L 1 , L 2 , L 3 , and L 4  for the actuator or the actuating means  30   a ,  30   b ,  32   a , and  32   b  are situated on both sides of the rotatable disk  38 . The bearing point L 1  for the actuating means  30   a  connected to the upper left pivot pin  18   a  and the bearing point L 4  for the actuating means  32   b  connected to the lower right pivot pin  24   b  are positioned on one side of the rotatable disk  38 . The bearing point L 2  for the actuating means  30   b  connected to the upper right pivot pin  18   b  and the bearing point L 3  for the actuating means  32   a  connected to the lower left pivot pin  24   a  are positioned on the other side of the rotatable disk  38 . 
         [0059]    The pivot pins  18   a ,  18   b ,  24   a ,  24   b  each has a respective locking device that can be embodied in different embodiment forms and will be described in greater detail in conjunction with  FIGS. 3 through 13 . The function of the locking device  41  that acts on the upper left pivot pin  18   a  will be explained below. The locking devices  41  mounted on the remaining pivot pins  18   b ,  24   a , and  24   b  are all embodied in the same way as it. 
         [0060]      FIG. 3  is a schematic side view of a closed door  14  with a hinge arrangement. The door is embodied as a metal door with a door interior  13   a  that is bordered by the door panel. 
         [0061]    The upper left pivot pin  18   a  shown in  FIGS. 1   a  through  1   c  and  2  can be brought from a retracted position, as shown in  FIG. 3 , in which the pivot pin  18   a  is not engaged with the pivot pin receptacle  20   a , into an extended position, not shown, by being vertically slid in the direction of the arrow S. The pivot pin  18   a  can be slid through a pivot pin passage  15  on the door edge  14   a  facing the housing part  22   a  that extends perpendicular to the pivot pin  18   a , moving in the direction of the pivot pin receptacle  20   a  aligned with the pivot pin passage  15 . In the extended position, the pivot pin  18   a  is then engaged with the pivot pin receptacle  20   a  and rotatably supported therein. The sliding occurs by the actuating rod  30   a , not shown, upon actuation of the actuating element  28  and rotatable disk  38  shown in  FIGS. 1   a  through  1   c  and  2 . 
         [0062]    An unlockable spring-loaded locking device  41  acts on the pivot pin  18   a . The locking device  41  has a securing spring  42  formed as a metal spring element composed of a piece of sheet metal. One end of the securing spring  42  is mounted to the outer surface  13   b  of the door  14  oriented toward the housing wall  23  by a screw connection  43  or by rivets. On the side oriented toward the housing wall  23 , the door  14  has an opening  44  leading to the door interior  13   a.    
         [0063]    The securing spring  42  extends from the screw connection  43  toward the housing wall  23 , then extends along the housing wall  23 , and finally extends at a right angle into the door interior  13   a . In the arrangement shown in  FIG. 3 , when the door  14  is closed, the housing wall  23  pushes the securing spring  42  toward the door interior  13   a  and holds it there under tension. In  FIG. 3 , the locking device is in its unlocked position. 
         [0064]    The part of the securing spring  42  extending in the door interior  13   a  has a through bore  45  extending perpendicular to the pivot pin  18   a , through which the pivot pin  18   a  extends. In the unlocked position of the locking device  41  shown in  FIG. 3 , the through bore  45  is aligned with the pivot pin passage  15  and the pivot pin receptacle  20   a.    
         [0065]      FIG. 4  is a schematic, sectional side view of the arrangement according to  FIG. 3 , in which the door  14  is open and the locking device  41  is locked. The securing spring  42  exerts its action between the door  14  and the pivot pin  18   a  and acts laterally on the pivot pin  18   a  in the locked position of the locking device  41 . 
         [0066]    In the arrangement shown in  FIG. 4 , when the door is open, the housing wall  23  is no longer pushing the securing spring  42  in the direction of the door interior  13   a  and holding it there under tension. The securing spring  42  can therefore relax. In so doing, the securing spring  42  slides the pivot pin  18   a  laterally into the locked position of the locking device  41  so that the sliding direction S of the pivot pin  18   a  points toward a region  49  of the door  14  adjacent to the pivot pin passage  15 . In the sliding direction S, the pivot pin  18   a  strikes against this region  49  and cannot be guided through the pivot pin passage  15 . The pivot pin  18   a  is locked in its retracted position. 
         [0067]    At the same time, the lower left pivot pin  24   a  shown in  FIGS. 1   a  through  1   c  and  2  is also locked in its retracted position in the same way. In this case, the hinge  16   a  embodied on the left attachment side  12   a  functions as an open latch. Because in this position, the actuating lever  40  is positioned in the actuation position for “opening the right attachment side” (POS 3 ), the hinge  16   b  on the right attachment side  12   b  is engaged. 
         [0068]    Because the pivot pins  18   a  and  24   a  cannot be brought into the extended position due to the locked locking device  41 , the actuating rods  30   a  and  32   a  shown in  FIG. 2  likewise can no longer be slid. This in turn affects the rotatable disk  38  so that the actuating rods  30   b  and  32   b  for the right hinge  16   b  also cannot be moved. The locking device  41  thus reliably prevents the open door from being inadvertently unhinged through actuation of the actuating lever  40 . 
         [0069]      FIG. 5  is a schematic, sectional side view of the hinge arrangement according to  FIGS. 3 and 4 , in which the door is open. Through direct manual force exertion, the securing spring  42  can be actuated in direction K in opposition to its prestressing direction, thus bringing the locking device  41  back into its unlocked position. 
         [0070]      FIG. 6  is a schematic, sectional side view of a closed door  14  with a different embodiment of a hinge arrangement. A securing spring  54  acts on the door  14  and has a guide plate  56  positioned perpendicular to the pivot pin  18   a , between it and the pivot pin passage  15 . 
         [0071]    The securing spring  54  is formed as a metal spring element composed of a piece of sheet metal. One end of the securing spring  54  is mounted to the outer surface  13   b  of the door  14  oriented toward the housing wall  23  by a screw connection  43  or by rivets. On the side oriented toward the housing wall  23 , the door  14  has an opening  44  leading to the door interior  13   a.    
         [0072]    The securing spring  54  extends from the screw connection  43  toward the housing wall  23 , then extends along the housing wall  23 , and finally extends at a right angle through the opening  44  into the door interior  13   a.    
         [0073]    In the arrangement shown in  FIG. 6 , when the door  14  is closed, the housing wall  23  pushes the securing spring  54  toward the door interior  13   a  and holds it there under tension. In  FIG. 6 , the locking device is in its unlocked position. 
         [0074]    The part of the securing spring  54  extending into the door interior  13   a  is embodied in the form of a guide plate  56  and has a through bore  58  extending perpendicular to the pivot pin  18   a . In the unlocked position of the locking device  41  shown in  FIG. 6 , the through bore  58  is aligned with the pivot pin passage  15  and pivot pin receptacle  20   a  so that the pivot pin  18   a  can be slid through the through bore  58 , the pivot pin passage  15 , and the pivot pin receptacle  20   a.    
         [0075]      FIG. 7  is a schematic, sectional side view of the arrangement according to  FIG. 6 , and the door  14  is open and the locking device  41  is in the locked position in which the guide plate  56  covers the pivot pin passage  15  at the top  14   a  of the door  14 . 
         [0076]    In the arrangement shown in  FIG. 7 , when the door  14  is open, the housing wall  23  is no longer pushing the securing spring  54  in the direction of the door interior  13   a  and holding it there under tension. The securing spring  54  can therefore relax. In so doing, the securing spring  54  slides the cover plate  56  into the locked position of the locking device  41  so that the sliding direction S of the pivot pin  18   a  no longer points through the through bore  58 , but at the underside of the cover plate  56 . In the sliding direction S, the pivot pin  18   a  strikes against the underside of the cover plate and cannot be guided through the through bore  58 . The pivot pin  18   a  is locked in its retracted position. 
         [0077]      FIG. 8  is a schematic, sectional side view of the hinge arrangement according to  FIGS. 6 and 7 . Through a direct manual exertion of force in direction K, the securing spring  42  can be actuated in opposition to its prestressing direction, thus bringing the locking device  41  back into its unlocked position. 
         [0078]      FIG. 9  is a schematic, sectional side view of a closed door  14  with a different embodiment of a hinge arrangement. The pivot pin  18   a  can be brought from a retracted position, as shown in  FIG. 9 , in which the pivot pin  18   a  is not engaged with the pivot pin receptacle  20   a , into an extended position by being vertically slid in the direction of the arrow S. The pivot pin  18   a  can be slid through a pivot pin passage  15  on the door edge  14   a  facing the housing part  22   a  that extends perpendicular to the pivot pin  18   a , moving in the direction of the pivot pin receptacle  20   a  aligned with the pivot pin passage  15 . In the extended position, the pivot pin  18   a  is then engaged with the pivot pin receptacle  20   a  and rotatably supported therein. 
         [0079]    An unlockable spring-loaded locking device  41  acts on the pivot pin  18   a . The locking device  41  has a securing spring  54  that is embodied in the form of a metal spring element of a piece of sheet metal. The securing spring  54  is mounted to the door interior  13   a  on the side oriented toward the housing wall  23  by a screw connection  43 . 
         [0080]    The securing spring  54  extends from the screw connection  43  toward the door interior  13   a , then extends parallel to the pivot pin  18   a , and finally, in the form of a cover plate  56 , extends at a right angle to the pivot pin  18   a . The cover plate  56  has a through bore  58  extending perpendicular to the pivot pin  18   a.    
         [0081]    In the unlocked position of the locking device  41  shown in  FIG. 9 , the through bore  58  is aligned with the pivot pin passage  15  and the pivot pin receptacle  20   a  so that through actuation of the actuating lever  40 , the pivot pin  18   a  can be slid through the through bore  58 , the pivot pin passage  15 , and the pivot pin receptacle  20   a.    
         [0082]    On the housing wall  23 , a pin  46  is provided, which, when the door  14  is closed, extends through an associated opening  47  into the door interior  13   a  and acts on the securing spring  54 , thus bringing the locking device  41  into its unlocked position. 
         [0083]      FIG. 10  is a schematic, sectional side view of the arrangement according to  FIG. 9 . The door  14  is open and the locking device  41  is in the locked position in which the guide plate  56  covers the pivot pin passage  15  at the top  14   a  of the door  14 . 
         [0084]    In the arrangement shown in  FIG. 10 , when the door  14  is open, the pin  46  positioned on the housing wall  23  is no longer pushing the securing spring  54  in the direction of the door interior  13   a  and holding it there under tension. The securing spring  54  can thus relax. In so doing, the securing spring  54  slides the cover plate  56  into the locked position of the locking device  41  so that the sliding direction S of the pivot pin  18   a  no longer points through the through bore  58 , but at the underside of the cover plate  56 . In the sliding direction S, the pivot pin  18   a  strikes against the underside of the cover plate and cannot be guided through the through bore  58 . The pivot pin  18   a  is locked in its retracted position. 
         [0085]      FIG. 11  is a schematic, sectional side view of the hinge arrangement according to  FIGS. 9 and 10 . The securing spring  42  can be manually actuated, through insertion of an actuating pin  48  into the opening  47 , in direction K in opposition to its prestressing direction, thus bringing the locking device  41  back into its unlocked position. 
         [0086]      FIG. 12  is a schematic, sectional side view of a closed door with yet another embodiment form of a hinge arrangement. An unlockable spring-loaded locking device  41  acts on the pivot pin  18   a . The locking device  41  has a securing spring  42  that is embodied in the form of a metal spring element composed of a piece of sheet metal. The securing spring  42  is mounted to the door interior  13   a , on the side oriented toward the housing wall  23 , by a screw connection  43 . 
         [0087]    The securing spring  42  extends from the screw connection  43  toward the door interior  13   a , then extends parallel to the pivot pin  18   a . At the free end of the securing spring  42 , an annular pin guide  52  is provided, in which the pivot pin  18   a  is supported. 
         [0088]    In the unlocked position of the locking device  41  shown in  FIG. 12 , the pin guide  52  is aligned with the pivot pin passage  15  and the pivot pin receptacle  20   a  so that through actuation of the actuating lever  40 , the pivot pin  18   a  can be slid through the pivot pin passage  15 , and the pivot pin receptacle  20   a.    
         [0089]    On the housing wall  23 , a pin  46  is provided, which, when the door  14  is closed, extends through an associated opening  47  into the door interior  13   a  and acts on the securing spring  42 , thus bringing the locking device  41  into its unlocked position. 
         [0090]      FIG. 13  is a schematic, sectional side view of the arrangement according to  FIG. 12 , in which the door  14  is open and the locking device  41  is in the locked position. The securing spring  42  exerts its action between the door  14  and the pivot pin  18   a  and, via the pin guide  52 , acts laterally on the pivot pin  18   a  in the locked position of the locking device  41 . 
         [0091]    In the arrangement shown in  FIG. 13 , when the door is open, the pin  46  positioned on the housing wall  23  is no longer pushing the securing spring  42  in the direction of the door interior  13   a  and holding it there under tension. The securing spring  42  can thus relax. In so doing, the securing spring  42  slides the pivot pin  18   a  laterally into the locked position of the locking device  41  so that the sliding direction S of the pivot pin  18   a  points at a region  49  of the door  14  adjacent to the pivot pin passage  15 . In the sliding direction S, the pivot pin  18   a  strikes against the region  49  and cannot be guided through the pivot pin passage  15 . The pivot pin  18   a  is locked in its retracted position.