Abstract:
A spare-wheel carrier for a motor vehicle is pivotable at a body of the motor vehicle and arranged in a region of a tailgate of the motor vehicle. The spare-wheel carrier includes at least one sensor configured to detect at least one position of the spare-wheel carrier and to transmit the at least one position to a control unit. The control unit is configured to enable and block at least one function of the motor vehicle in accordance with the position of the spare-wheel carrier.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application claims priority to Application No. 202 20 177.5, filed in the Federal Republic of Germany on Dec. 30, 2002, and Application No. 203 04 381.2, filed in the Federal Republic of Germany on Mar. 13, 2003, each of which is expressly incorporated herein in its entirety by reference thereto. 
   FIELD OF THE INVENTION 
   The present invention relates to a spare-wheel carrier for a motor vehicle. 
   BACKGROUND INFORMATION 
   In the branch of off-road motor vehicles, it is believed to be conventional that a spare wheel can be mounted outside of the motor vehicle, e.g., in the region of a tailgate. Due to the positioning of the spare wheel in the rear section with the aid of a spare-wheel carrier, the tailgate is only partially accessible or inaccessible as long as the spare wheel is attached. Therefore, it is believed to be conventional that the spare-wheel carrier can be pivoted at the body to swivel it from a position nearly parallel to the tailgate to a position of nearly 90° or more, in order to thereby obtain unencumbered access to the tailgate. However, the tailgate and/or the spare-wheel carrier are often damaged, because, for example, the tailgate is opened, but the spare-wheel carrier is still in a position where it collides with the opened tailgate. 
   Therefore, it is an aspect of the present invention to provide a spare-wheel carrier, where collisions with other vehicle parts or other damage to the spare-wheel carrier may be prevented. 
   SUMMARY 
   The above and other beneficial aspects of the present invention may be achieved by providing a spare wheel carrier as described herein. Additional aspects of the present invention are also described herein. 
   To this end, at least one position of the spare-wheel carrier may be detectable and transmittable to a control unit with the aid of a sensor, functions of the motor vehicle being able to be unblocked or blocked as a function of the position of the spare-wheel carrier. In this context, a sensor is generally to be understood as both a sensory system and a switch, by which a position of the spare-wheel carrier may be detectable. Examples of the functions, which are unblocked or blocked, may include access options, operating functions, driving functions, etc. For example, access to or the enabling of the tailgate, the opening of the rear window, the starting or driving-off of the motor vehicle, etc. may be made a function of the position of the spare-wheel carrier. This enabling or blocking may be directly accomplished by the control unit, or the control unit may transmit the position of the spare-wheel carrier to other control units. To this end, the control units may be interconnected by a CAN or LIN bus, or the control unit may transmit its information via a gateway to control units situated in other bus systems. 
   In an example embodiment, the position of the spare-wheel carrier may be represented on a display unit, the display unit, e.g., taking the form of an instrument cluster. This may allow the motor-vehicle driver to rapidly and clearly receive the information about the position of the spare-wheel carrier at a usual location, since he or she may normally receive a display of the position of doors and tailgates in the instrument cluster. 
   In an example embodiment, the spare-wheel carrier may be lockable. This may ensure that the spare-wheel carrier does not move, in particular, during an off-road trip. By having the position of the spare-wheel carrier represented on the display unit, the driver may be informed, prior to starting a trip, whether or not the spare-wheel carrier is locked, so that he may take appropriate measures to prevent it from swinging out during the trip. 
   In an example embodiment, the sensor may take the form of a lock having a touch-sensitive switch, a position of the spare-wheel carrier being detectable by the touch-sensitive switch, and the spare-wheel carrier being lockable by the lock. In the simplest case, the touch-sensitive switch may detect the position, “Spare-wheel carrier locked?” 
   In an example embodiment, the lock may be assigned an actuator, which may be manipulable with the aid of a grip switch. The actuator may take the form of an electric motor, which may be energized and unlock the lock in response to manipulation of the grip switch. Accordingly, the motor may be energized, when the touch-sensitive switch detects that the spare-wheel carrier has been swung into the position for locking. 
   In another example embodiment, the lock for locking may be arranged to have at least two locking elements, one locking element being attached to the body of the vehicle, e.g., to a tailgate, and a complimentary locking element being attached to the spare-wheel carrier. One locking element may include a striker, the striker being arranged to have a ball and a pin. The complimentary locking element may include at least two hinged ball sockets, which may receive the ball of the striker. The striker may rotate in the ball sockets, thereby allowing an effective adjustment for tolerance. Due to spatial considerations, the locking element, including the ball sockets, may be attached to the spare-wheel carrier. 
   The striker may be supported in a further ball. In this manner, the striker is not rigidly fastened, but may be swivelled about its transverse axes to compensate for tolerance. 
   In an example embodiment, the swivelling of the ball sockets from a closed position into an open position may be blocked by a movable blocking part, the locking element being unlocked by displacing and/or tilting the blocking part. In the open position, the ball sockets are in a stable equilibrium position. When the ball of the striker is received by the ball sockets, the ball sockets are swivelled about assigned axes and assume a closed position. In the closed position, and/or in the event of a movement into the closed position, a blocking element is moved and/or tilted between the ball sockets in such manner, that the ball sockets are prevented from swinging back into the open position. The blocking element may be swivelled and/or tilted into the locked position by spring forces. 
   In an example embodiment, the ball sockets may be held in a closed position by a catch hook, using its own weight. Due to their own weight, the catch hooks load the ball sockets and, in this manner, prevent the ball sockets from swinging back into the open position. 
   In an example embodiment, a release device may be arranged to have at least one lever, the lever being operable by an actuator and/or manually. An example embodiment having a lever mechanism may mimic the unlocking device in a simple manner. 
   In an example embodiment, the lock may be arranged to have an emergency release device that includes an emergency release lock, the spare-wheel carrier being manually releasable by the emergency release device. In this context, the emergency release lock includes a striker having at least one rotatable actuator, the actuator being rotatable into at least an unlocked and a locked position, and, in the unlocked position, the lever for unlocking the spare-wheel carrier being driven by displacing the striker, and, in a locked position, the lever for unlocking the spare-wheel carrier not being driven by displacing the striker. 
   In an example embodiment, the emergency release device may include a least one lever, the lever being positioned in such a manner, that at least one lever for releasing the spare-wheel carrier may be actuated by the lever. This may allow various mechanisms of the lock to be simultaneously released, and rapid access is therefore possible in emergency situations. 
   In an example embodiment, at least one bearing of the spare-wheel carrier on the body may be assigned an end switch. A specific, swung-open position of the spare-wheel carrier may be detectable with the aid of the end switch. 
   In an example embodiment, the tailgate may be assigned an additional grip switch, the tailgate being operable as a function of the spare-wheel carrier position detected by the end switch. Therefore, it may be ensured that the tailgate is only released when the spare-wheel carrier is swivelled out far enough to prevent a collision with the tailgate to be swung open. In this context, the end switch is preassigned a specific angular position at which the contact closes, this angular position not necessarily having to be the actual end position of the spare-wheel carrier. 
   In an example embodiment, the operation of the rear window may be blocked when a locked spare-wheel carrier is detected. 
   The present invention is described below on the basis of exemplary embodiments. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a spare-wheel carrier on the rear end of a vehicle. 
       FIG. 2  is a perspective view of the spare-wheel carrier. 
       FIG. 3  is a simplified block diagram of the electric circuitry. 
       FIG. 4   a  is a representation of the motor vehicle on a display unit. 
       FIG. 4   b  illustrates a display-unit representation of the motor vehicle having the spare-wheel carrier. 
       FIG. 5  is an exploded view of the swung-out spare-wheel carrier. 
       FIG. 6  is a sectional view of the locking element. 
       FIG. 7  is a view of a lock. 
       FIG. 8  is a perspective view of an emergency release device. 
   

   DETAILED DESCRIPTION 
   In all of the figures, the same reference numerals are used for identical component parts. 
   A rear end  2  of a vehicle, including a tailgate  21 , a rear window  25 , and a spare-wheel carrier  1 , is illustrated in  FIG. 1 . In the represented, locked state, spare-wheel carrier  1  rests on tailgate  21  and is attached to tailgate  21  by a lock. In the locked position of spare-wheel carrier  1 , one is blocked from opening tailgate  21  via a rotating motion about axis H. In addition to tailgate  21 , rear window  25  may also be controlled as a function of the position of spare-wheel carrier  1 . For example, it may be provided that rear window  25  only be able to be opened when spare-wheel carrier  1  is swung out. However, it is also possible to allow rear window  25  to be opened in the case of a swung-back spare-wheel carrier  1  not having a spare wheel, using, e.g., an appropriate signal of a radio remote control. 
   Spare-wheel carrier  1  is illustrated in  FIG. 2 . Spare-wheel carrier  1  includes a carrier part  12  for mounting a spare wheel on an axis R. Carrier part  12  has a swivel arm  13 , via which carrier part  12  is pivoted in a bearing  14 . Bearing  14  is attached to vehicle rear end  2  shown in  FIG. 1 , using suitable fastening device. In this context, instead of one swivel arm  13 , models having two or more swivel arms are, in principle, also possible. Situated in bearing  14  is a hidden end switch  15 , which is connected to a control unit. End switch  15  is visible, for example, in  FIG. 5 . Carrier part  12  is arranged to have a grip switch  16 , an actuator  17  represented by hidden lines, and a lock  18 , which has a touch-sensitive switch  19  and is represented by hidden lines. Spare-wheel carrier  1  may be fastened to the body of the motor vehicle by lock  18 . Grip switch  16  and touch-sensitive switch  19  are connected to the control unit, as well. 
   In order to now get at tailgate  21 , which is at least partially covered by spare-wheel carrier  1 , one initially manipulates grip switch  16 . This manipulation of grip switch  16  is transmitted to the control unit. The control unit triggers actuator  17 , which consequently unlocks lock  18 . In addition to the unlocking, it may also be provided that carrier part  12  be moved into a pre-locking position. The user may swing open carrier part  12  in the direction of bearing  14 , until carrier part  12  is in a desired position. At or beyond a preset angular position of, e.g., 90°, end switch  15  closes and transmits this status to the control unit, which consequently enables tailgate  21  to be opened. In addition to the position of spare-wheel carrier  1 , the enabling of tailgate  21  is normally a function of other conditions. 
     FIG. 3  illustrates a simplified block diagram of the electric circuitry. Grip switch  16  of spare-wheel carrier  1  illustrated in  FIG. 2  and a grip switch  23  of tailgate  21  illustrated in  FIG. 1  are connected to a common port  30  of a control unit  3 . In a similar manner, touch-sensitive switch  19  and end switch  15  are connected to a common port  31  of control unit  3 . In addition, control unit  3  is connected to actuator  17 . In this context, the connection may either be made as shown, via a separate port  32 , or via a bus line  33 . Control unit  3  is connected, for example, to a control unit of the central locking system via bus line  33 . In this context, the common use of each of ports  30 ,  31  may not be necessary but, as explained below, possible. Grip switch  16  and touch-sensitive switch  19  each are assigned a series resistor Rv, by which the signal is resistance-coded. In this context, the fact that the signals must occur in a certain order during regular operation is utilized. In the locked state of spare-wheel carrier  1 , all four switches are initially open. In the first step, a user manipulates grip switch  16 , whereby the switch is closed and an operating voltage drops across series resistor Rv. This switching action is detected by control unit  3 , and actuator  17  is driven. In this manner, lock  18  illustrated in  FIG. 2  is unlocked, and spare-wheel carrier  1  moves into a pre-locking position, which means that switch  19  closes. If no pre-locking position is present, then switch  19  only closes when the user begins to swing spare-wheel carrier open. If the user swings spare-wheel carrier  1  open to a particular angular position, then end switch  15  closes, and the operating voltage is now switched to ground, which is detected, in turn, by control unit  3 . If grip switch  23  of tailgate  21  is now closed, then control unit  3  may unblock the tailgate, since control unit  3  detects that spare-wheel carrier  1  is in a non-critical position. Using the occurring order of the signals, control unit  3  may therefore check the operability of the individual elements. 
   Control unit  3  is connected to further control units of another bus system via port  34 . For this purpose, control unit  3  transmits information to an instrument cluster  4  via a bus  35 . It is also possible to transmit to a gateway in place of transmitting to an instrument cluster. Bus  35  may be constructed as a 2-wire CAN, a 1-wire LIN, a free communications interface, etc. 
   As explained above, the position of spare-wheel carrier  1  may not be the only condition for releasing tailgate  21 . For example, the enablement of grip switches  16  and/or  23  may be limited in time. For example, grip switches  16 ,  23  are activated for a certain period of time when a remote radio link sends a signal. In addition, it may be provided that this signal only results in an activation when the ignition key is not inserted, in order to prevent manipulation from the outside. Furthermore, the grip switches may be enabled by an authorized rear-end key, or by manipulating a switch situated in the interior of the motor vehicle, whereby the internal locking system must be switched off. In this context, it may also be provided that the temporal enabling of the grip switches be extended, when, e.g., it is detected that one of the grip switches is being manipulated or the tailgate is in the pre-locking position. The enabling of the grip switches is canceled, for example, after a specifiable time, when the tailgate or rear window is closed from the open state or pre-locking position. In a similar manner, the enablement may be canceled or interrupted, when the vehicle is locked from the outside and no enable signal comes from the interior switch, or the tailgate is locked in the pre-locking position. In addition, the tailgate is blocked when the vehicle moves, i.e., has a speed that is greater than a limiting speed. A further option for blocking the tailgate is an active safety interlock. This blocks both the doors and the tailgate after driving off, and only re-enables them when a door is opened from the inside. 
     FIG. 4   a  illustrates a display unit  41  for representing the position of a spare-wheel carrier  1  illustrated in  FIG. 1 . In this context, display unit  4  may be arranged on an instrument cluster illustrated in  FIG. 3 . Display unit  41  includes at least one field  42 , on which a vehicle pictograph  43  is displayable. For example, open vehicle doors, defective vehicle lights, and further information relating to the vehicle, etc., are displayable on the vehicle pictograph. In addition, the display unit includes a display bar  44  for alphanumerically displaying changing information. In the illustrated view, a kilometer reading and an outer temperature are displayed on display bar  44 . In addition, it is possible to have a display of an oil temperature, an engine temperature, an interior vehicle temperature, the remaining cruising range, etc. The engaged gear of an automatic shifter or transmission may be deduced, for example, from a second display bar  45 . 
   In  FIG. 4   b , a warning of an open spare-wheel carrier  1  is illustrated on display unit  41 . Spare-wheel carrier  1  illustrated in  FIG. 1  is assigned a pictograph  46 . If spare-wheel carrier  1  is not locked at the rear end of the vehicle, then a user receives a corresponding indication of it on display unit  41 , using an illuminated pictograph  46  and/or color markings. 
     FIG. 5  schematically illustrates an exploded view of vehicle rear end  2  having an opened spare-wheel carrier  1 . As previously explained, spare-wheel carrier  1  is locked to tailgate  21  by a lock  18 . In this context, lock  18  includes a locking element  18 ′, which is attached to tailgate  21 , and a locking element  18 ″, which is attached to spare-wheel carrier  1 . 
   Locking element  18 ′ is schematically illustrated in  FIG. 6 . Locking element  18 ′ includes a striker  1 ′, which is formed by a ball  10 ′ and a pin  11 ′. Pin  11 ′ is rigidly connected to a bearing ball  12 ′. Bearing ball  12 ′ is supported in a bearing  2 ′. Bearing  2 ′ includes a bearing shell  20 ′, which is rigidly connectible to a flange  3 ′ for connection to vehicle tailgate  21 , and a movable bearing shell  21 ′, which is movable with respect to bearing shell  20 ′. Bearing shell  21 ′ is held in the displayed position by a spring  22 ′. However, striker  1 ′ may be tilted about its transverse axes in opposition to a force of spring  22 , in order to compensate for tolerances. 
     FIG. 7  schematically shows lock  18 , including locking element  18 ′ and locking element  18 ″, which is attached to spare-wheel carrier  1 . Ball  10 ′ of striker  1 ′ is accommodated in locking element  18 ″ by two ball sockets  10 ″. Ball sockets  10 ″ may swivel about axes  101 ″. Upon receiving ball  10 ′, they swivel from an open position into the illustrated, closed position. In this context, a blocking part  11 ″ moves between arms  102 ″ of ball sockets  10 ″ in such a manner, that it is not possible for them to swivel back into the open position. If blocking part  11 ″ between arms  102 ″ of ball sockets  10 ″ is removed and/or tilted, then the ball sockets swivel about axes  101 ″ into the open position due to, for example, spring tension, and they consequently release locking element  18 ′. Locking element  18 ″ may be opened by actuator  17 . Blocking part  11 ″ is connected to a lever  12 ″ by rod  112 ″, lever  12 ″ swivelling about an axis  120 ″. For opening, lever  12 ″ is moved by actuator  17  into illustrated arrow direction O. The movement is transmitted by rod  112 ″ to blocking part  11 ″, and in this manner, blocking part  11 ″ between arms  102 ″ of ball sockets  10 ″ is removed. 
   To increase the safety from spare-wheel carrier  1  swinging out, locking element  18 ″ is arranged to have an additional catch hook  14 ″, the own weight of which opposes the swivelling-back movement of ball sockets  10 ″ about axis  101 ″. Catch hook  14 ″ may be swivelled about an axis  150 ″ by a lever  15 ″. Lever  15 ″ may be moved by actuator  17 , as well. 
   To provide manual releasing and/or additional emergency releasing in response to the failure of actuator  17 , locking element  18 ″ is arranged to have an emergency release device. The emergency release system includes a lever  170 ″. A movement of lever  170 ″ in marked direction N causes lever  170 ″ to swivel about an axis  171 ″. Lever  170 ″ has a hook  172 ″, which drives levers  12 ″,  15 ″ during its movement. In this manner, lever  12 ″ is swivelled about its axis  120 ″ and lever  15 ″ is swivelled about its axis  150 ″, and lock  18  is thereby unlocked. 
     FIG. 8  illustrates emergency release device  17 ″, which includes lever  170 ″ and an emergency release lock  173 ″ having a striker  174 ″. Emergency release lock  173 ″ has a keyhole  176 ″ and may be unlocked by a key. For example, it may be the vehicle key. The unlocking causes an actuator  175 ″ to rotate in a direction E, so that, when striker  174 ″ is moved in direction N, lever  170 ″ is driven by actuator  175 ″. In this case, lever  170 ″ swivels about axis  171 ″, as described, levers  12 ″,  15 ″ being driven by hook  172 ″. For purposes of locking, actuator  175 ″ is rotated again in direction E. In the locked state, actuator  175 ″ does not depress lever  170 ″ in response to a displacement of striker  174 ″, so that spare-wheel carrier  1  is not released when emergency release device  17 ″ is locked. The key for unlocking the emergency release device may be removable in a locked state only.