Abstract:
A power-assisted closing device ( 1 ) for doors, flaps, folding tops or roofs of vehicles, in particular passengers cars, having a pivotably mounted rotary latch ( 2 ) which interacts with a fastening peg, a detent pawl ( 7 ) which releasably locks the rotary latch ( 2 ), and an actuating drive which acts via a disk cam ( 13 ) on the rotary latch ( 2 ) and the detent pawl ( 7 ) to effect an unlocking or locking procedure, wherein a pivotable stop element ( 17 ) is arranged on the rotary latch ( 2 ) and a pivotable stop element ( 20 ) is arranged on the detent pawl ( 7 ), the stop element ( 17, 20 ) interacting with the disk cam ( 13 ) in the unlocking or locking procedure.

Description:
RELATED APPLICATION 
     This is a continuation application of my copending application (including a CPA Application) Ser. No. 09/337,111 filed Jun. 21, 1999 under 35 USC 120 now abandoned. 
    
    
     FIELD AND BACKGROUND OF THE INVENTION 
     The invention relates to a power-assisted closing device for doors, flaps, folding tops or roofs of vehicles, in particular passenger cars, in accordance with the features of the preamble of patent claim 1. 
     DE 37 08 095 A1 discloses a power-assisted lock for doors, flaps, folding tops or roofs on vehicles, which has a pivotably mounted rotary latch which interacts with a fastening peg, it being possible for the rotary latch to be releasably locked by a detent pawl and furthermore for it to be able to be driven to effect an unlocking or locking procedure by a power-dispensing member. 
     Furthermore, a functional disk having at least one latching projection for the detent pawl in the unlocking position of the lock and a bevel for releasing the detent pawl from the latching position into the switching position is mounted pivotably next to the rotary latch. Moreover, the rotary latch is likewise provided in the opposite direction of rotation with a latching projection and a bevel each having the same function, and a hydraulic cylinder is coupled to the functional disk, the functional disk having a play-afflicted drive-type connection to the rotary latch. The rapidly advancing rotation of the rotary latch, which is caused by the fastening peg during the locking, unlocks the functional disk, the rapidly advancing rotation of the functional disk, which is caused by the return of the hydraulic cylinder or is manually triggered, unlocking the rotary latch during unlocking. 
     Although a design of this type has been proven with regard to good reliability, the complex form of the rotary latch and the detent pawl, but also of the functional disk with its associated bevels and slots in which the hydraulic cylinder engages, results in a costly construction. Moreover, during the installation of the power-assisted lock the position of the functional disk with the hydraulic cylinder coupled thereto has to be brought into a defined position with regard both to the detent pawl and also to the rotary latch so that the sloping surfaces of the functional disk can come into operative connection with the associated sloping surfaces of the detent pawl or of the rotary latch. This means that the outlay on installation is increased. 
     SUMMARY OF THE INVENTION 
     The invention is therefore based on the object of providing a power-assisted closing device which in addition to the required, utmost reliability is also distinguished by a simple construction and ease of installation. The aim with this power-assisted closing device is to open and close the doors, flaps, folding tops or roofs of vehicles in a power-assisted manner or else automatically. 
     According to the invention, provision is made for a respective stop element to be pivotably mounted on the rotary latch and on the detent pawl, the stop elements interacting with the disk cam, which is driven by an actuating drive, in the opening procedure (in other words: unlocking procedure) or in the closing procedure (in other words: locking procedure). That means that in the unlocking procedure the stop element on the detent pawl is effective for opening (unlocking) the rotary latch, while the stop element on the rotary latch is ineffective and hence pivoted away in this case. On the other hand, in the locking procedure it is such that the stop element which is arranged on the rotary latch is effective so that by the latter the actuating drive can drive the rotary latch and lock the closing device. In this case, the stop element which is arranged on the detent pawl is ineffective. This arrangement ensures that the pivotable stop elements can be installed on the rotary latch and on the detent pawl, the detent pawl and the rotary latch being rotably mounted in a housing of the closing device. The assignment of the rotary disk cam to the detent pawl and the rotary latch results in installation being easy and rapid without attention having to be paid during the installation as to the position in which the disk cam has to be aligned with regard to the detent pawl or the rotary latch. 
     In a development of the invention, a restoring spring is assigned to a respective stop element. This ensures in a simple manner that the respectively appropriate stop element is effective or ineffective in the unlocking procedure or in the locking procedure. In the ineffective case, the stop element is rendered ineffective by the force of the restoring spring being overcome. In the effective case, the stop element bears by means of a form fit against the relevant counter part (rotary latch or detent pawl), with the result that the actuating drive can act via the disk cam on this counter part for unlocking or locking. 
     In a development of the invention, the disk cam has a peg which acts on the stop elements. The installation is further improved by this refinement, in particular by a peg protruding perpendicularly from the surface of the disk cam, a further advantage which can be mentioned being the flat construction. Installation is therefore made easy since the disk cam is pushed, for example, onto a peg of a housing half shell and further pegs are provided on the housing half shell to receive the detent pawl and the rotary latch. In the process, attention does not have to be paid to a certain position when fitting the elements and so malfunctions caused by erroneously installed elements are also avoided during initial operation. 
     In a development of the invention, the rotary latch can be driven in a geared-down manner by the actuating drive, this being required in order to overcome the forces when shutting the door (for example, triggered by the weight of the door or else the sealing forces). 
     In a development of the invention, the actuating drive is an electric motor which drives the disk cam in a geared-down manner. The advantageous result of this is a compact constructional unit. 
     In a development of the invention, for the locking procedure the actuating drive acts via the disk cam on the stop element of the rotary latch and for the unlocking procedure on the stop element of the detent pawl. That is to say that depending on the type of procedure only the one stop element is subjected to force and thus a function which is required for this desired procedure is triggered. In addition, it is thereby ensured that also only the desired procedure is triggered when the actuating drive is activated. Thus, for example in the locking procedure, i.e. when the rotary latch is being rotated and thus when the door is being shut, the detent pawl cannot be operated since if this was operated it would result in the locking procedure being terminated or prevented. The same happens in the unlocking procedure so that it is ensured that when, the detent pawl is driven to the effect of providing opening assistance, the door cannot be shut again onto the rotary latch by being subjected to force. This is thus a very important safety aspect. 
     In a development of the invention, the rotary latch has a preliminary catch which interacts with the detent pawl and a main catch, means being provided which detect at least the preliminary catch position of the rotary latch. This ensures that an operator brings the door, the rear flap or the trunk lid, for example, from the opened position into the so called preliminary catch position, the fastening peg, which is arranged on the door, the rear flap or the trunk lid, being intercepted by the rotary latch and held in a preliminary closing position. It should further be noted here that the fastening peg can also be arranged on a vehicle part which is secured to the body and the power-assisted closing device with the rotary latch, detent pawl, disk cam and actuating drive can be arranged in the door or the like. 
     As soon as the door or the like is brought into the preliminary closing position, this is recognized by the means and the actuating drive for the locking procedure (shutting assistance) is activated. As an alternative to the means which detect the preliminary catch position of the rotary latch, means can also be provided which detect the preliminary closing position of the door or the like per se. In a development of the invention, the means comprise a preliminary catch switch which can be operated by the rotary latch or the stop element thereof and optionally a main-catch switch which can be operated by the detent pawl. Means for detecting the position and on which the activation of the actuating drive depends can thereby be integrated in the immediate vicinity of the elements of the closing device, in particular can be integrated therewith in a housing. The outlay on cabling is thus also reduced as long as these switches (or other means in general) are accommodated in the housing together with the actuating drive and a control device which has yet to be described. 
     In a development of the invention, the actuating drive, in particular of the electric motor, can be operated in block mode. That means that the actuating drive is activated and drives the disk cam until the latter runs, in particular with its peg, onto the stop element which acts in a positively locking manner with the rotary latch or with the detent pawl, specifically in a manner such that further driving of the disk cam is no longer possible. This can be evaluated in a suitable manner (for example, by evaluating the increase in power of the actuating drive) and the actuating drive can be switched off as a result. Means for positional control (for example, microswitches, restoring springs or other means) can thus be dispensed with, as a result of which the installation is again simplified and the number of elements reduced. 
     In a development of the invention, the pivotably mounted detent pawl is subjected to force in the direction of the rotary latch, it thereby being ensured that after the detent pawl has been pivoted by the disk cam out of the operative range of the rotary latch, the detent pawl itself can again enter into operative connection with the rotary latch (for locking). 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     One possible constructional refinement of the closing device, to which the invention is not, however, restricted, is described in the following and explained with reference to the figures. 
     The figures show the following: 
     FIGS. 1 to  9 : a power-assisted closing device in the various functional positions, 
     FIG.  10 : a control device for activating the actuating drive. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     FIGS. 1 to  9  show the various functional positions of a power-assisted closing device  1 , only the elements of the power-assisted closing device  1  being enumerated and described with reference to FIG. 1 for the time being. 
     The power-assisted closing device  1  has a rotary latch  2 , the rotary latch  2  being mounted such that it can rotate about a pivot  3 . This pivot  3  can be realized, for example, as a peg which protrudes from a housing, in particular from a housing half shell. The rotary latch  2  furthermore has a recess  4  into which a fastening peg  4 A can be introduced and after it has been introduced can be held immovably, this position corresponding to a closing position of the door or the like. In the opening position the fastening peg can slide out of the recess  4 . The rotary latch  2  furthermore has a preliminary catch  5  and a main catch  6  which are designed as projections of the rotary latch  2  and interact with a corresponding counter projection on a detent pawl  7 . The detent pawl  7 , which is designed as a separate component, is likewise mounted such that it can rotate about a pivot  8  which is designed in the same manner as the pivot  3 . FIG. 1 shows that the detent pawl  7  has an extension  9  which will be gone into a more detail below. 
     The power-assisted closing device  1  furthermore has as actuating drive an electric motor  10  which bears a worm  12  on its motor shaft  11 , the worm  12  being arranged rotably on the motor shaft  11  by being pressed on, for example. 
     The power-assisted closing device  1  furthermore also has a disk cam  13  which is mounted such that it can rotate about a pivot  14 . The disk cam  13  is of flat design and over its entire circumference has a worm thread  15  which meshes with the worm  12 . It is thus possible for the disk cam  13  to be driven by the electric motor  10  via the worm  12  and the worm thread  15  in a geared-down manner. The disk cam  13  has a peg  16 , which is produced integrally with the disk cam  13  (as is the worm thread  15 ) or else is subsequently installed, protruding approximately perpendicularly from the disk cam  13  (i.e. from the plane of FIG.  1 ). 
     A pivotable stop element  17  is now arranged on the rotary latch  2 , this pivotable stop element  17  being mounted such that it can rotate about a pivot  18  on the rotary latch  2 . The pivotable stop element  17  is deflected from the position shown in FIG. 1 counter to the force of a restoring spring  19  by means of the peg  16 . Depending on the position of the rotary latch  2  and rotational direction of the disk cam  13 , the pivotable stop element  17  interacts with the rotary latch  2  in a positively locking manner to rotate the rotary latch  2  about the pivot  3 , it being possible, however, for the pivotable stop element  17  also to be moved about the pivot  18  once the force of the restoring spring  19  has been overcome without pivoting the rotary latch itself. 
     In an analogous manner thereto, the detent pawl  7  has a pivotable stop element  20  which is mounted such that it can rotate about a pivot  21  on the detent pawl  7 . In this case too the pivotable stop element can be pivoted counter to the force of a restoring spring  22  without the detent pawl  7  being deflected or is connected to the detent pawl  7  in a positively locking manner in such a way that the detent pawl  7  can be pivoted under the effect of the rotational movement of the peg  16  onto the pivotable stop element  20 . 
     The power-assisted closing device  1  moreover also has a preliminary catch switch  23  which can be operated by the detent pawl  2  (or by the pivotable stop element  17 ), a main-catch switch  24  furthermore also being provided, which switch is arranged in such a manner that it can be operated by the extension  9  of the detent pawl  7  (or also by the pivotable stop element  20 ). While in FIG. 1 the rotary latch  2  is shown with a preliminary catch  5  and a main catch  6  and also with the associated preliminary catch switch  23  and the main-catch switch  24 , the rotary latch  2  can also be designed with just a single catch. 
     In the following, the sequence of movement, i.e. a locking procedure (shutting) and an unlocking procedure (opening) is described with reference to FIGS. 1 to  9 . 
     FIG. 1 shows the rotary latch  2  in an opened position, i.e. the door, the flap or the like is open. The electric motor  10  has been switched off since the peg  16  has moved to form a block against the pivotable stop elements  17  of the rotary latch  2 . The motor is now switched off; neither the preliminary catch switch  23  or the main-catch switch  24  are operated. 
     FIG. 2 shows that by the user moving the door the rotary latch  2  has been brought into the preliminary catch position so that the preliminary catch  5  has been arrested in this preliminary catch position by the corresponding projection on the detent pawl  7 . At the same time, the pivotable stop element  17  or a corresponding extension on the rotary latch  2  thereby operates the preliminary catch switch  23  and activates the electric motor  10  which moves the disk cam  13  counterclockwise (when looking at FIG.  2 ). The peg  16  first reaches the pivotable stop element  20  of the detent pawl  7 . 
     FIG. 3 now shows that on further rotation of the disk cam  13  the peg  16  deflects the pivotable stop element  20  of the detent pawl  7  counter to the force of the restoring spring without the detent pawl  7  itself being operated. As before, the preliminary catch switch  23  is operated so that the electric motor  10  is furthermore activated. The main-catch switch  24  is not operated yet. 
     FIG. 4 shows that a further rotation of the disk cam  13  counterclockwise causes the peg  16  to strike against the pivotable stop element  17  of the rotary latch  2 . The pivotable stop element  20  of the detent pawl  7  has in the meantime been pivoted back into its starting position because of the force of the restoring spring  22 . The pivotable stop element  17  is in FIG. 4 in a position in which it is coupled in a positively locking manner to the rotary latch  2 . As before, the preliminary catch switch  23  is operated while the main-catch switch  24  is as before inoperative. The rotary latch  2  is still in its preliminary closing position. Starting from the position of the peg  16  which is shown in FIG. 4, said peg by further rotation causes the rotary latch  2  to rotate clockwise about its pivot  3 . As a result, the main catch  6  comes into operative connection with the projection on the detent pawl  7  so this further rotation causes the door or the like to be shut and likewise locked. 
     FIG. 5 now shows that the door is closed so that the rotary latch  2  is also in its arrested closing position. Since the preliminary catch switch  23  is, as before, operated and the electric motor  10  is, as before, activated, the peg  16  rotates further counterclockwise, specifically until it runs onto a block on the detent pawl  7 . The electric motor  10  is switched off, either by the further movement of the peg  16  on the detent pawl,  7  being blocked and/or by the main-catch switch  24  being operated by the extension  9  on the detent pawl  7 , and so the shutting procedure is thereby finished. The power-assisted closing device  1  is now in the rest state again. If the door or the like is then to be opened again, the following procedure is required. 
     FIG. 6 shows that the peg  16  is moved, after the electric motor  10  is activated, in the counterclockwise direction from its rest position shown in FIG. 5, in precise terms past the pivotable stop element of the rotary latch  2 . During this movement both the preliminary catch switch  23  and also the main-catch switch  24  are operated. On further rotation of the peg  16 , said peg reaches the stop element  20 , which is connected in this case in a positively locking manner to the detent pawl  7 , with the result that further rotation of the peg  16  causes the detent pawl  7  to be deflected so that the projection on the detent pawl  7  can come into operative connection with the preliminary catch  5  of the rotary latch  2 . 
     FIG. 7 shows this state of the projection of the detent pawl  7  being in operative connection with the preliminary catch  5 . In this case, the preliminary catch switch  23  is, as before, operated while the main-catch switch  24  is inoperative. As before, the electric motor  10  remains activated so that the peg  16  is moved further in the clockwise direction until it reaches the pivotable stop element  17  of the rotary latch  2 . FIG. 8 then shows that on further rotation of the peg  16 , the latter deflects the pivotable stop element  17  counter to the force of the restoring spring  19  without in the process triggering an effect on the rotary latch  2 ; i.e., the rotary latch  2  further remains in the preliminary catch position. As before, the preliminary catch switch  23  is, operated while the main-catch switch  24  is, as before, inoperative. 
     FIG. 9 shows that further rotation in the clockwise direction causes the peg  16  to strike against the pivotable stop element  20  of the detent pawl  7 , further rotation of the peg  16  causing the stop element  20  to be further deflected, because of the positively locking connection of said stop element  20  to the detent pawl  7 , with the result that the projection on the detent pawl  7  is disengaged from the preliminary catch  5  and the rotary latch  2 , which in particular is subjected to spring force, can thereby be moved in the opening direction, as a result of which the fastening peg in the recess  4  is released and the door or the like can be opened. Since during this movement the preliminary catch switch  23  is, as before, operated (main-catch switch  24  as before inoperative), the peg  16  is further rotated until it runs onto a block on the rotary latch  2  or the stop elements  17  thereof, which is in turn shown in FIG.  1 . Following the opening procedure (opening assistance) just described, the power-assisted closing device  1  is thus prepared for the locking procedure described already from FIG.  1 . 
     As FIGS. 1 to  9  reveal, in the preliminary catch position the detent pawl  7  has a position which deviates from the main catch position. 
     FIG. 10 describes a further control device  25  which controls the sequences of movement which are shown and described in FIGS. 1 to  9 . The signals from the preliminary catch switch  23  and the main catch switch  24  are supplied to the control device  25 , the control device  25  activating the electric motor  10 . The control device  25  furthermore also has an input unit  26  which is integrated in it or is external and by means of which the unlocking procedure (opening assistance) and the locking procedure (shutting assistance) can be triggered by an operator. This input  26  is situated, for example, in the interior of the vehicle and it may, for example, be a switch mounted on a door inside handle so that after the door inside handle is operated, the opening assistance for opening the door is triggered. The control device  25  moreover also has an external input unit in the form of a remote control  27  which can be operated from outside the vehicle. The remote control  27  is, for example, a wireless remote control, so that at the push of a button the unlocking procedure (opening assistance) and/or the locking procedure (shutting assistance) can be triggered. Alternatively or supplementary thereto, it is also possible for a switch or the like to be arranged on the door outside handle so that the unlocking procedure is triggered after the door outside handle is operated. It is inherently understood here that the abovementioned functions proceed in conjunction with further functional positions of the closing device of the vehicle, such as, for example, theft-protection position, central locking position or central unlocking position, and is coordinated with these positions. FIG. 10 also shows that a measuring device  28 , is provided on or in the electric motor  10 , which device detects a parameter of the electric motor  10  so that the block mode can be controlled by means of the measuring device  28 . If, for example, an increased current consumption of the electric motor  10  or else a failure of the voltage supply is ascertained by the measuring device  28 , this is a sign that the electric motor  10  has run onto block and the activation can be switched off. For this purpose, the control device  25  correspondingly evaluates the signal output by the measuring device  28 . Instead of a measuring device  28  provision can also be made for the electric motor  10  to be activated for a predetermined time for the movement from one rest position into the next rest position, this time being dimensioned in such a manner that the electric motor  10  reliably reaches the next position. If the electric motor  10  then runs in block mode, it remains activated for a short time up until the activation time has elapsed, and it is then switched off. 
     LIST OF REFERENCE NUMBERS 
       1 . Power-assisted closing device 
       2 . Rotary latch 
       3 . Pivot 
       4 . Recess 
       5 . Preliminary catch 
       6 . Main catch 
       7 . Detent pawl 
       8 . Pivot 
       9 . Extension 
       10 . Electric motor 
       11 . Motor shaft 
       12 . Worm 
       13 . Disk cam 
       14 . Pivot 
       15 . Worm thread 
       16 . Peg 
       17 . Pivotable stop element 
       18 . Pivot 
       19 . Restoring spring 
       20 . Pivotable stop element 
       21 . Pivot 
       22 . Restoring spring 
       23 . Preliminary catch switch 
       24 . Main catch switch 
       25 . Control device 
       26 . Input 
       27 . Remote control 
       28 . Measuring device