Abstract:
A drive for opening and closing a cover member in a motor vehicle has a lever which includes a detent device, for example a spring-loaded pin, which is pressed into a detent notch by force of a spring and is disengageable when a predetermined force is exceed and as a result disconnects an electric motor for opening and closing said cover member. It is therefore possible to open the cover member even when the electric motor fails, by disengaging the lever by hand, and the lever forms an overload safety device for the electric motor in the event of the cover member becoming jammed.

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a drive for opening and closing a cover member in a motor vehicle. 
     The cover member is provided especially as a cover member of a glove compartment or other storage compartment in a motor vehicle and/or as a covering for a car radio, CD player or some other similar device built into the motor vehicle. Operating elements of the motor vehicles can be incorporated in the cover member, such as, for example, controls or switches for seating-heating, a warning light system and the like, that have to be, or should be, accessible at all times, that is to say when the cover member is open and when it is closed. The cover member is in principle closed and is opened only as required, for example at the touch of a button, by an electric motor so that in the event of an accident no objects can fall out of the storage compartment. 
     The drive according to the invention comprises an electric motor that moves the cover member, which is also associated with the drive, by way of a path transmission element, for example a pushing and pressure-applying rod. The problem arises, for example in the event of a power failure, defective control of the drive, a defect in the electric motor or in a reduction gear system, when present, that the cover member cannot be opened. It may be important, however, to be able to open the cover member also in such cases in order, for example, to be able to remove objects contained in a storage compartment that is closed by the cover member, such as important medication, documents or the like. 
     SUMMARY OF THE INVENTION 
     Accordingly, it is an object the present invention to provide a drive for opening and closing a cover member in a motor vehicle, which avoids the disadvantages of the prior art. 
     More particularly, it is an object of the present invention to provide the drive for opening and closing the cover member in a motor vehicle, such that it is possible to open the cover member when the drive fails. 
     In keeping with these objects and with others which will become apparent hereinafter, one feature of present invention resides, briefly stated, in a drive which has a disconnecting device, which disconnects the cover member from the electric motor when a predetermined force acting upon the cover member is exceeded. As a result, the cover member can be opened by hand without movement of the electric motor. The disconnecting device according to the invention, for example, can disconnect the path transmission element from the electric motor or may disable the path transmission element itself. 
     The invention has the advantage that the cover member can be opened by hand independently of the electric motor. A further advantage of the invention is that the disconnecting device forms an overload protection for the electric motor, which disconnects the cover member from the electric motor if the cover member becomes jammed when the electric motor is running. 
     The disconnecting device can, for example, be in a form providing frictional engagement and can transmit a limited force or a limited moment normally sufficient to open and close the cover member. In an embodiment of the invention, a detent element is provided as disconnecting device, which disengages when the predetermined force is exceeded and as a result disconnects the drive of the cover member mechanically from the electric motor. This has the advantage that the force required for disconnection can be set relatively precisely and can be maintained in mass production. A further advantage is that, after the detent element has disengaged, the cover member can be moved smoothly. There is also the advantage that the detent element can be re-engaged after the drive has been rectified, and the drive according to the invention is not damaged as a result of the predetermined force being exceeded. 
     In a special embodiment of the invention, the path transmission element comprises a lever that converts a rotational movement of the electric motor into a translational movement for opening and closing the cover member. At the same time, that lever forms the disconnecting device that disconnects the cover member from the electric motor when the predetermined force is exceeded 
     In a development of the invention, the lever is in the form of a detent element. 
     In an embodiment of the invention, the detent element comprises a detent body, for example a ball or a pin, which is pressed into a detent notch by a spring element. By overcoming a detent force, the detent body can be disengaged from the detent notch, as a result of which the cover member is disconnected from the electric motor. 
     In an embodiment of the invention, the drive comprises an insert that is guided displaceably in the manner of a drawer. The insert forms, for example, a storage compartment or a seat for installation a car radio, CD player or the like. The insert can be displaced by the electric motor especially by way of the lever explained above. The insert forms a path transmission element that transmits a drive movement of the electric motor to the cover member, which is connected pivotably to the insert. The cover member comprises a guiding element that moves it sideways when the insert is displaced to a pulled-out position. “Moved sideways” means that the cover member is moved to a position in which the insert is accessible. For that purpose, the cover member can be moved upwards, downwards or sideways. When the insert is pushed in again, the cover member moves back to a closed position in which it covers the insert. That construction of the invention can be achieved together with the disconnecting device according to the invention or without it. 
     In an embodiment of the invention, the cover member has at least one arm by way of which it is connected pivotably to the insert, for example by means of a pin connection. By way of the pin connection, the cover member can be driven by displacement of the insert. 
     In a preferred construction, the cover member comprises a slide-type guiding element. A slideway preferably extends at an angle relative to the direction of displacement of the insert and as a result causes the desired sideways movement of the cover member when the insert is pulled out. On insertion of the insert, the slide-type guiding member moves the cover member back to the position in which it closes the insert. The slideway does not have to be straight; for example, it can extend in a curve. The slideway can be arranged in a fixed position, for example in a housing in which the insert is displaceably accommodated. The slideway can also be arranged in the arm of the cover member, and a fixed-position sliding pin, sliding block or the like engages in the slideway. 
     The invention will be explained hereinafter in greater detail with reference to an embodiment shown in the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a lever of a drive according to the invention; 
     FIG. 2 is a longitudinal section through the lever of FIG. 1; along line II—II in FIG. 3; 
     FIG. 3 is a plan view of the lever of FIG. 1; and 
     FIG. 4 is a partially cut-away side view of a drive according to the invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The drive in accordance with the present invention has a lever  10  shown in FIGS. 1-3 and is explained below with reference to FIG.  4 . The lever  10  has a base portion  12  of rectangular cross-section that is low in comparison with its width, the height of which base portion is constant over its entire length and the width of which decreases from one end to the other. the two ends of the base portion  12  are rounded in an arc of a circle (FIG.  3 ). The base portion  12  is provided with a slit  14  which extends over approximately ⅔ of the length of the lever  10  and passes through the base portion  12  in a plane with the lever  10 , that is to say in a transverse direction. 
     Positioned in the slit  14  in the base portion  12  is a coupling lever  16 , which can be rotated about a notional axis of rotation  18  of the lever  10  relative to the base portion  12 . Concentrically with the axis of rotation  18 , which extends perpendicular to the slit  14 , the base portion  12  and the coupling lever  16  inserted therein are pierced by aligned hole  20 ,  22 , the hole  20 ,  22  in the coupling lever  16  having a serrated profile  24  to enable an interlocking engagement therein, for cojoint rotation, of a motor or gear shaft (not shown in FIGS. 1 to  3 ). 
     The base portion  12  and the coupling lever  16  are made of plastics material. In order to reinforce the coupling lever  16 , a metal platelet  26  is inserted in the end of the coupling lever that faces the closed end of the slit  14 , the metal platelet being indicated by a broken line in FIG.  3 . On an edge facing the closed end of the slit  14 , the metal platelet  26  has a semi-circular detent notch  28 . 
     In the end of the base portion  12  remote from the coupling lever  16 , a spring-loaded pin  30  is inserted. The spring-loaded pin  30  lies in a cylindrical housing  32  and is pressed by a compression spring (not visible in the drawing) that is inside the housing  32  into the detent notch  28  of the metal platelet  26  inserted in the coupling lever  16 . The spring-loaded pin  30  and its housing  32  are also indicated in FIG. 3 by broken lines. 
     On the upper side at the end remote from the axis of rotation  18 , the base portion  12  has an upward projecting pin  34 , on which there is rotatably positioned a sliding block  36  that is square in plan view. 
     The lever  10  functions as follows: the lever  10  serves to convert a rotation movement into a linear movement. The rotational movement is transmitted by a motor or gear shaft (not shown in FIGS. 1 to  3 ) to the coupling lever  16  positioned in the base portion  12 . For that purpose, the motor or gear shaft has a serrated profile complementary to the serrated profile  24  of the coupling lever  16 , by means of which the motor or gear shaft engages in the coupling lever  16  so that the coupling lever rotates conjointly therewith. By way of the spring-loaded pin  30  that lies in the detent notch  28  of the metal platelet  26  inserted in the coupling lever  16 , the rotational movement of the coupling lever  16  is transmitted to the base portion  12  so that the sliding block  36  moves in a circular path. The circular movement of the sliding block  36  can be used to displace an element (not shown in FIGS. 1 to  3 ) with which the sliding block  36  is in engagement. 
     If the lever  10  is overloaded, the spring-loaded pin  30  is pressed out of engagement with the detent notch  28  so that the base portion  12  and the sliding block  36  are freely rotatable relative to the coupling lever  16  inside the base portion  12 , the coupling lever  16  being arranged to rotate conjointly with the motor or gear shaft (not shown) by way of its serrated profile  24 . The purpose of the ability of the base portion  12  to disengage from the coupling lever  16  is firstly that when the lever  10  is jammed at the sliding block  36  the motor can continue to turn and does not become overloaded. Also, when the motor is not turning, for example as a result of a power failure, defect or failure of a motor control system, the base portion  12  can be disengaged from the coupling lever  16  and moved relative to the coupling lever  16  by pulling or pushing the sliding block  36 . After such a fault has been overcome, the base portion  12  is re-engaged in the detent notch  28  and the lever  10  becomes fully operational again. The lever  10  is thus not damaged by the disengagement. 
     From the above explanation of the lever  10 , it will be clear that the lever together with the spring-loaded pin  30  that co-operates with the detent notch  28  comprises a detent element that forms a disconnecting device  28 ,  30  of the lever  10 . 
     FIG. 4 shows the use of the lever  10  from FIGS. 1 to  3  as a component of a drive according to the invention. In the embodiment shown, the drive according to the invention serves to open and close a compartment, for example a storage compartment (glove compartment) or a compartment for the installation of a car radio, CD player or the like. The compartment has a cub-like housing  38  of rectangular cross-section. The housing  38  is designed to be installed, for example, in a dashboard of a motor vehicle (not shown). The housing  38  is open at the front side and can be closed by a cover member  40 . Inside the cover member  40  there can be inserted operating elements, such as, for example, switches for a seat-heating system, a warning light system or instruments (not shown), which are accessible and readable when the cover member  40  is closed as well as when it is open. The closed position of the cover member  40  is indicated in FIG. 4 by a continuous line, and the open position of the cover member  40  is shown by a dash-dot line. 
     An insert  42  is arranged in the housing  38  to be displaceable in the manner of a drawer. The insert  42  has a base  44  and side walls  46 , one of which side walls  46 , remote from the observer, is visible because of the cut-away representation in the left-hand portion of FIG.  4 . 
     Below the base  44  of the insert  42 , the lever  10  is arranged in an opening  48  in a housing floor  50 . The opening  48  gives the lever  10  space to pivot As described for FIGS. 1 to  3 , the lever  10  together with its coupling lever  16  is positioned on a gear shaft  52  to rotate conjointly therewith. The gear shaft  52  has a serrated profile complementary to the serrated profile of the lever  10 . In order to pivot the lever  10 , there is arranged on the underside of the housing floor  50  an electric motor  54  having flanged-on gears  56 , from which there projects the gear shaft  52 , by means of which the lever  10  can be pivoted. The lever  10  rests by its sliding block  36  in a sliding block seat in the base  44  of the insert  42 , the sliding block seat being rectanglular in plan view, so that the sliding block  36  can move sideways relative to the insert  42 , that is to say transverse to the direction of displacement. By pivoting the lever  10 , the insert  46  is moved translationally and is moved forwards and backwards in the housing  38 , that is to say to the right and left in the drawings. 
     The cover member  40  has arms  58 , each arranged laterally on the insides of the side walls  46  of the insert  42 . The arms  58  of the cover member  40  have holes, by means of which they are positioned on pins  60  that project inwards from the side walls  46  of the insert  42 . The insert  42  forms a path transmission element of the drive according to the invention, which path transmission element transmits the drive movement of the electric motor  54  having the flanged-on gears  56  by way of the lever  10  to the arms  58  of the cover member  40 . 
     The arms  58  of the cover member  40  have outwardly projecting sliding pins  62  which lie in sideways  64  in side walls  66  of the housing  38 . Since the front portion of the housing  38 , which is on the right in FIG. 4, is shown in elevation, in the front region  38  of the housing  38  the side wall  66  thereof that faces the observer is seen in elevation from the outside. The sliding pin  62  of the arms  58  of the cover member  40  engages through openings (not visible in the drawing) in the side walls  46  of the insert  42 . The sliding pins  62  are arranged spaced at a distance in front of and below the pins  60  that project inwards from the side walls  46  of the insert  42  and on which the arms  58  of the cover member  40  are positioned to pivot. The slideways  64  extend in a curved line initially approximately parallel with the housing floor  50  and continue forwards/upwards in a curved line. w hen the insert  42  is displaced forwards, that is to say to the right in FIG. 4, by the electric motor  54  by way of the gears  56  and the lever  10 , it moves the arms  58  of the cover member  40  forwards by way of the pins  60 . As that happens, the sliding pins  62  of the arms  58  slide forwards and upwards in the slideways  64  so that the cover member  40  moves, as shown, from the closed position in which it closes the housing  38  that is open at the front side to an open position in front of the housing  38 , above and oblique thereto. In the open position of the cover member  40 , the housing  38  is accessible. When the insert  42  is pushed back into the housing  38  by the electric motor  54 , the cover member  40  returns to its closed position in which it closes the housing  38 . 
     If the drive of the lever  10 , that is to say the electric motor  54  having the flanged-on gear  56 , is not operational, for example as a result of a defect or power failure, the cover member  40  can be opened manually. This is done by pulling on the cover member  40  in the closed position of the cover member  40 . By way of its arms  58 , the cover member  40  draws the insert  42  in the housing  38  forwards. The lever  10  is thus pivoted forwards. As described in FIGS. 1 to  3 , the spring-loaded pin  30  inside the base portion  12  of the lever  10  disengages from the detent notch  28  of the coupling lever  16  lying pivotably inside the base portion  12 , as a result of which the base portion  12  that carries the sliding block  36  can pivot freely on the gear shaft  52 . By pulling on the cover member  40 , the lever  10  can be disengaged. To do so it is necessary initially to pull firmly on the cover member  40  in order to disengage the lever  10 , and once the lever  10  has been disengaged, the cover member  40  can be moved easily. 
     In the event of the cover member  40  or the insert  42  becoming jammed and the electric motor  54  being actuated, the lever  10  disengages also as described, so that the motor  54  can turn and does not become overloaded. Once the fault has been overcome, the lever  10  is re-engaged by closing or opening the cover member  40  manually and is thus operational again. 
     It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above. 
     While the invention has been illustrated and described as embodied in drive for opening and closing a cover member in a motor vehicle, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. 
     Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.