Abstract:
An unlocking device for actuating a control device in the locked condition to release it. The unlocking device has an actuating magnet guided in a coil base and/or in housing elements ( 28 ) of the actuating magnet and has an actuating element that can be displaced and that releases, in an actuation position, an unlocking path for a control unit has a locking element ( 30 ). The locking element, when unlocked by the actuating element via the control unit, releases the trajectory for the control device to be actuated. The locking device ( 30 ) is guided in the housing element ( 28 ) of the actuating magnet and prevents the control device from being unintentionally locked again by maintaining it in the unlocked position by a blocking part ( 48 ). The unlocked position corresponds to a release of the control device.

Description:
FIELD OF THE INVENTION 
     The invention relates to an unlocking device for actuating a control part in the locked state to release it, with an actuating magnet guided in a coil base and/or in housing parts of the actuating magnet. An actuating element can be moved and, in the actuating position, clears an unlocking path for a control unit having a locking part. The locking part, unlocked by the actuating element via the control unit, clears the path of movement for the control part to be actuated. 
     BACKGROUND OF THE INVENTION 
     Unlocking devices such as these can be used for a plurality of applications. Especially wherever it is important to execute an initiation process for a technical component in a dedicated and reliable manner, unlocking devices with actuating magnets are preferred. This actuating magnet even in rough, everyday operation, for example, when exposed to vibrations or impacts, is reliable in use, as experience shows. With the unlocking device according to the invention, especially in the motor vehicle domain, safety-relevant parts can be unlocked and caused to operate, whether in the form of a roll bar which is to be deployed or in the form of a headrest which moves forward in a crash, in order to reduce the free impact path between the back of the head of the seat occupant and the head impact surface on the headrest, etc. 
     In these unlocking devices, the actuating magnet with the actuating element and movable control unit can be housed in a very small installation space. These devices can then be accommodated in a space-saving manner within motor vehicles. As a result of the space-saving structure, these unlocking devices can also be used directly at the site of the initiation process, where previously, in the prior art, optionally Bowden cables which are complex to manage have accomplished the initiation process over greater path distances. 
     On the other hand, for safety-relevant applications of these unlocking devices, there is, however, the danger of loss of operating reliability. After an initiation process in which the pertinent safety means has been activated by triggering the control part, in many cases it is necessary, in order to ensure operating reliability, to replace the safety means itself or its parts by new parts before reactuation. In other words, there is the risk that an already activated safety means will be inadvertently returned to the initial position, the control part will be returned to the locked state by the unlocking device, and the safety means which is no longer reliable after completed activation is “armed” again. 
     SUMMARY OF THE INVENTION 
     An object of the invention is to provide an unlocking device in which the danger of this loss of operating reliability of an assigned safety means is avoided. 
     According to the invention, this object is basically achieved by an unlocking device having a locking part guided in the housing part of the actuating magnet. A blocking part keeps the locking part in the unlocked position corresponding to the release of the control part to prevent unintentional re-locking of the control part. 
     In one especially advantageous embodiment, the blocking part is formed by a spring clamp guided with its free spring ends at least partially along the housing part for movement between the blocking position in which the locking part is held by the spring clamp in the unlocked position, and the position in which the locking part is released for re-locking of the control part. The arrangement can preferably be made such that the spring clamp is accessible to manual movement out of the blocking position. 
     The spring clamp can be shaped such that the free spring ends in the blocking position between themselves form a clamping gap for clamping the locking part in the unlocking position. 
     In embodiments characterized by a design enabling simple and comfortable handling, oblique guides are on the housing part. When the spring clamp moves out of the blocking position into the position releasing the locking part, the oblique guides form control surfaces for the spring ends. The central surfaces spread the spring ends apart from one another and widen the clamping gap to release the locking part for return into the position locking the control part. 
     Other objects, advantages and salient features of the present invention will become apparent from the following detailed description, which, taken in conjunction with the annexed drawings, discloses a preferred embodiment of the present invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Referring to the drawings which form a part of this disclosure and which are schematic and not to scale: 
         FIG. 1  is a front perspective view and an unlocking device according to an exemplary embodiment of the invention; 
         FIG. 2  is a side elevational view in section of the device of  FIG. 1  in the locked state; 
         FIG. 3  is a side elevational view in section of the device of  FIG. 1  in the unlocked state; 
         FIG. 4  is a perspective top view of the actuating magnet with a ratchet of the device of  FIG. 1 ; 
         FIG. 5  is a partially cutaway perspective view of the housing of the device of  FIG. 1 , with the blocking element inserted; and 
         FIG. 6  is a partial perspective view of the blocking element blocking the locking part of the device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The unlocking device for the control part  10 , according to the perspective view of  FIG. 1  showing its most important components, includes an actuating magnet  12 . The actuating magnet  12  has a coil base  14  with a coil winding (not detailed) and in which a cylinder shaped or rod shaped actuating element  16  is guided to be able to move lengthwise. 
     The actuating magnet  12 , made in the manner of a conventional electromagnet, is designed such that when power is supplied to the coil base  14  via a connector  18 , the actuating element  16  is pulled to the inside, that is, in the view of  FIG. 2 , in the direction of the rear plane of the figure. A reset spring (not detailed) can reset the actuating element  16  when the coil base  14  is not energized. The actuating element with a definable projection then protrudes over the front of the coil base  14  including the front of the actuating magnet  12 . In this respect the actuating element  16  is therefore arranged to be able to move along a first axis  20 . 
     In the actuating position of the unlocking device shown in  FIG. 3 , the actuating element  16  is pulled to the rear by the actuating magnet  12  and thus clears a swiveling or pivoting path  22  extending transversely to the first axis  20  and shown in  FIG. 3  with an arrow. Along this swiveling or pivoting path  22 , control unit  24  pivots clockwise around a second axis  26  extending parallel to the first axis  20 . This second axis  26  is, for example, made as a pivoting axle or pivoting journal. Its free ends are guided on the end side in the housing part  28 , preferably formed from a suitable plastic material. As is further shown in  FIGS. 1 to 3 , the control unit  24  has a locking part  30 . When unlocked by the actuating element  16  by way of the control unit  24 , locking part  30  clears the path  32  of movement, shown in  FIG. 3  with an arrow, for the control part  10  to be actuated. Inasmuch as  FIGS. 1 and 2  relate to the locked position for the control part  10 , the locking part  30  at least partially encompasses the control part  10  and in this way holds it in the locked position. 
     The control unit  24  has a pivoting lever  34 , as shown in  FIG. 4 . The pivoting lever  34  is guided to be able to pivot around the second axis  26  in the housing part  28  which for the sake of simplicity has been omitted in  FIG. 4 . The pivoting lever  34  on its one free end in the unactuated state of the actuating magnet  12  is in contact with the actuating element  16 . As shown in  FIG. 4  the actuating element  16  can be moved into the coil base  14  of the actuating magnet  12  to clear the pivoting path  22  for the pivoting lever  34 . Accordingly, in the retracted position of the actuating element  16 , actuating element  16  forms with its front essentially a plane front surface with the front of the coil base  14  facing the viewer of  FIG. 4 . 
     As shown in  FIG. 4 , the pivoting lever  34  is still in its unactuated position. On the other end of the pivoting lever  34 , the control part  10  is then held in the locking position. The locking part  30  of the control unit  24  is made in the manner of a claw or jaw opening  36 . This locking part  30  can be arranged centrally, that is, force-equalized in the middle of the device (cf.  FIG. 1 ). In this respect, the pivoting lever  34  has an axial offset  38  located therein to ensure this center arrangement. For the unlocking process, the claw or jaw opening  36  pivots clockwise around the pivoting axis  26  out of the locked position as shown in  FIGS. 1 and 2  into the unlocked position as shown in  FIG. 3 . 
     In certain application tasks, a rotary spring or the like can be attached to the second axis  26  to move the pivoting lever along the swiveling path  22  as soon as the actuating element  16  has been pulled into the coil base  14 . In this case, however, in the actuated state of the actuating magnet  12 , the control part  10  by an energy storage device will cause unlocking for the pivoting lever  34  from the outside which then pivots around the second axis  26  into the unlocked position. For this reason, the control part  10  provides for a spring clamp, preferably in the form of a double spring clamp  40 , with an energy storage device in the form of spring energy in the unlocked state enabling pivoting away along the path  32  of movement from the control unit  24  for the control part  10 . Specifically, control part  10  pivots around a third axis  42  extending parallel to the first axis  20  and the second axis  26 . Based on the inherent dynamics of the control part  10  in the form of the double spring clamp  40 , it is therefore sufficient to actuate the actuating magnet  12  to be able to undertake unlocking, controlled from the outside. 
     The actuating magnet  12  is made in the shape of a cup. In this respect, actuating magnet  12  has an annular coil base  14  with winding ends connected respectively to the connector  18 . As the actuating element  16 , the coil base  14  encompasses a flat-cylindrical actuating rod. The rod comparably has a cup shape to the annular coil base  14  and is guided to be able to move lengthwise therein. As  FIG. 4  furthermore shows, the pivoting lever  34 , on its one free end facing the actuating element  16  in the manner of a catch, is provided tapering with a curvature at least partially following the curvature of the outer periphery of the actuating element  16  (cf. also  FIG. 2 ). The double spring clamp  40  with its clamp part  44  in the locking position engages the locking part  30  of the control unit  24 . The two round springs  46  relating to the double arrangement encompass the third axis  42  in the middle. 
     If, as shown in  FIG. 3 , the control part  10  is pivoted counterclockwise back around the axis  42 , the clamp part  44  catches again in the claw or jaw opening  36 . The pivoting lever  24  then pivots counterclockwise into its initial position as shown in  FIG. 4 . If at this point the actuating magnet  12  is no longer energized, the actuating element  16 , for example, under the action of a reset spring (not detailed), withdraws until the outside periphery of the actuating element  16  then again adjoins the inside of the pivoting lever  34 . By a corresponding reset process, the unlocking device could again be “armed”. In the invention this rearming is prevented, for example, because parts of a safety means (not shown) or the safety means itself must be replaced. Therefore, provision is made against the clamp part  44  again unintentionally engaging the locking part  30  and its claw or jaw opening  36  in the corresponding manner. To prevent this engagement, the locking part  30  is held in its unlocking position shown in  FIG. 3 . The blocking part  48  shown in  FIG. 5  prevents unintentional re-locking of the control part  10 . 
     The blocking part  48  includes a spring clamp  50  with free spring ends  52  guided at least partially along the housing part  28  and movable into the position to release the locking part  30 . To better illustrate these conditions, in  FIG. 5 , relative to the front view, part of the wall of the housing part  28  is omitted to illustrate the action of the spring clamp  50  on the top of the locking part  30 . In the position shown in  FIG. 5 , the spring clamp  50  forms the blocking part in its unblocking position. When the unlocking process is actuated, the locking part  30  snaps upward and moves into the clamping gap between the spring ends  52  in the blocking position. 
     The spring ends  52  between themselves then clamp a portion of the locking part  30  as shown in  FIG. 6  such that it is held in the unlocking position as shown in  FIG. 3 . If at this point, viewed in the direction of  FIG. 5 , the spring clamp  50  is pushed down by hand, the free spring ends  52  slide along the oblique guides  54  of the housing part  28  so that the spring ends  52  are spread apart from one another and then clear the swiveling path for the locking part  30 . Locking part  30  can then return to the locking position. In a repeated unlocking process, the locking part  30  snaps upward again, and in this way entrains the spring clamp  50  with re-formation of the clamping gap for the locking part  30 , so that then it is blocked again in its unlocked position and cannot be pivoted back unintentionally into the locking position. 
     The unlocking means according to the invention can be used for a plurality of applications. Instead of a control part  10  in the form of a double-spring clamp arrangement  40 , a single spring (not shown) can be used. Other technical components such as, for example, parts of a roll bar system can be held by the claw or jaw opening  36  of the locking part  30  so that in this respect the range of application can be expanded at will. 
     The solution according to the invention is characterized especially by the fact that operation is controlled by a single lever in the form of the pivoting lever  34 . 
     While one embodiment has been chosen to illustrate the invention, it will be understood by those skilled in the art that various changes and modifications can be made therein without departing from the scope of the invention as defined in the appended claims.