LOCK HAVING RESTRICTED GUIDANCE FOR A PAWL

The invention relates to a lock for a motor vehicle with a locking mechanism comprising a catch and two pawls, by means of which the catch can be snapped into two respective closed positions. One of the pawls engages the catch in a primary position (hereinafter called the “primary-position pawl”). The other pawl engages the catch in a first position (hereinafter called the “first-position pawl”). The lock also includes a blocking lever for said primary-position pawl. Such a lock is known from DE 10 2007 003 948 A1.

A catch of a motor vehicle lock has a fork-shaped inlet slot into which a locking pin of a vehicle door or hatch enters when the car door or hatch is closed. The locking pin then rotates the catch from an open position to a closed position. When the catch reaches the closed position, the locking pin can no longer leave the inlet slot of the catch. In a closed position, the pawl engages the catch such that the catch can no longer be rotated back into the open position.

Known are locks with two closed positions, which are assumed consecutively during the closing of the catch, namely the so-called first position and the so-called primary position.

To prevent the pawl from being unexpectedly moved out of these notched positions, a blocking lever can be provided that blocks such movement when the catch assumes a notched position. Such a blocking lever is necessary for the primary-position pawl of the lock described in DE 10 2007 003 948 A1 because the catch and the primary-position pawl are constructed such that the pawl assuming the primary position pushes the primary-position pawl out of the notched position.

The rotatably arranged blocking lever described in DE 10 2007 003 948 A1 is biased by a spring. Because of this bias, when the catch is not in the primary position, the blocking lever exerts pressure on the primary-position pawl toward the direction of the catch. This pressure is responsible for ensuring that the primary-position pawl is moved into a notched position when the catch reaches the primary position. The bias then further ensures that the blocking lever is ultimately moved into a blocked position to complete the vehicle door or hatch closing.

To unlock the lock, the blocking lever is rotated with the help of the first-position pawl against the biasing force until the blocking lever sets free the primary-position pawl. The primary-position pawl is then pushed by the catch from the notched position or is stricken by a driver of the first-position pawl and so is moved out of the notched position. The driver is a long hole in the first-position pawl into which a pin attached to the primary-position pawl extends. Subsequently, the catch rotates from the primary position into its open position due to an appropriately set bias. The locking pin can then move out of the inlet slot, and the attached vehicle door or hatch can be pushed ajar.

It is one object of the invention to provide an inexpensive lock for a motor vehicle that can fit into a small space.

The object of the invention is achieved by providing a lock having the characteristics of the first claim. Advantageous embodiments are described in the dependent claims.

To achieve the object of the invention, a lateral contour area of the first-position pawl is provided to function as a driver that strikes and moves a pin attached to the primary-position pawl. Because of this, the primary-position pawl can be rotated out of its notched position. Because a slot does not need to serve as a driver, material is saved and installation space is reduced.

In one embodiment, the primary-position pawl is pushed out of a notched position by the catch, as described in DE 10 2007 003 948 A1, and the pin attached to the primary-position pawl is made of plastic. Usually, it would be necessary to make the pin out of metal for reasons of stability because of the stresses experienced by the pin. The stresses are, however, relatively small in this embodiment because the primary-position pawl is pushed out of a notched position by the catch. In general, this pressure is high enough to move the primary-position pawl out of a notched position after the primary-position pawl is released by the blocking lever. Even if the driver should still strike the pin, only a small force would be required to rotate the primary-position pawl out of the notched position. It is, therefore, not necessary to manufacture the pin from metal. A relatively light and cheap pin made of plastic, e.g., polypropylene, is, therefore, sufficient.

In one embodiment of the invention, the primary-position pawl comprises a lever arm to which the pin is attached. This lever arm is made particularly of metal and is encased with plastic or is made at least partially of plastic. The remaining portion of the primary-position pawl is made of metal. In this case, a limiter is provided for the lever arm, and this limiter is fully or partially made of plastic. The limiter limits the rotation of the primary-position pawl in the direction toward a notched position. The limiter ensures that the primary-position pawl does not rotate past a certain position due to the inertial mass, for example, during rapid rotation.

The limiter advantageously also functions as a stop for the first pawl, which is preferably biased by a spring toward a notched position. If a bias is present, the first-position pawl is prevented by the stop from rotating past its notched position. The primary-position pawl, however, is not biased. The corresponding lever arm of the primary-position pawl does not, therefore, normally put pressure on the limiter, especially since the primary-position pawl, and hence also the limiter, is pushed away by the catch in the opposite direction.

The limiter is preferably made of a metal pin, which is encased by a sheath of elastic material. In this way, the impact of the corresponding lever arm of the first-position pawl is dampened. In addition, the plastic of the primary-position pawl is treated with care.

To bias the first-position pawl, the first-position pawl preferably further comprises an additional lever arm, which extends into an area, which runs perpendicularly to the housing wall, to which wall the catch is rotatably attached. In this way, an area is provided against which an arm of the torsion spring can press. In addition, this perpendicular area is also used in order to strike the first-position pawl, and preferably to move it by means of a motor when the associated vehicle door or hatch is opened. The height of the lock does not need to be increased, therefore, when the two pawls are arranged one on top of the other, as is known from DE 10 2007 003 948 A1. The perpendicular arrangement thus ensures that the base of the lock does not need to be increased.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a closed position of a lock with a first-position pawl being transparent (not shown);

FIG. 2 shows the closed position of the lock of FIG. 1;

FIG. 3 shows an open position of the lock of FIG. 1; and

FIG. 4 shows an intermediate position of the lock of FIG. 1.

An exemplary embodiment of the invention shown in the figures will be explained hereinbelow in more detail. Advantages of further embodiments of the invention will be illustrated with reference to the exemplary embodiment.

FIG. 1 shows a plan view of a housing wall 1 of a vehicle lock. The housing wall 1 is provided with an inlet slot 2, into which a locking pin 3 of a vehicle door or vehicle hatch enters when the corresponding vehicle door or vehicle hatch is closed. The catch 4 is rotatably mounted on the housing wall 1 and can be rotated about its mounting axis 5. FIG. 1 shows the primary position, in which the locking pin 3 located in the inlet slot 2 in the wall housing is enclosed by the inlet slot of the catch such that the locking pin 3 can no longer be moved out of the inlet slot 2 in the wall housing. The corresponding door or hatch of the vehicle is thus closed. It is obvious that the primary position is shown here because in this figure, the action of turning back the catch according to the arrow direction 22 toward the open position is blocked by the primary-position pawl 6. The primary-position pawl 6 is also mounted on the housing wall 1 and is rotatable about its mounting axis 7. The catch is biased toward the direction of the open position, preferably by a spring (not shown). Because of this bias, the catch presses diagonally against a stop of the primary-position pawl. This diagonal movement pushes the main locking pawl out of the notched position.

If the catch is not biased by a spring, when said vehicle door or hatch is opened, at least the locking pin 3 causes the rotation of the catch 4 toward the open position, as indicated by the arrow 22. The associated torque then pushes the primary-position pawl 6 out of the notched position.

However, this is prevented in the primary position by the blocking lever 8 when the vehicle door or hatch is closed, as shown. The blocking lever 8 is also mounted on the housing wall 1 and can be rotated about its mounting axis 9. On a lateral contour area of the blocking lever 8 is disposed an arm 10b of a spring 10. The spring 10 is biased such that the arm 10b of the spring 10 presses the blocking lever in the direction toward the shown blocking position (in the direction of arrow 11). The rotational movement of the blocking lever caused thereby is limited, as shown by the stop 12, which is attached to the housing wall 1 in the form of a protruding pin. The stop 12 causes the blocking lever to be positioned always very precisely in the same blocking position, which is particularly important for the proper functioning. The spring 10 is arranged predominantly laterally next to the blocking lever 8 as well as next to the first-position pawl to allow for a low profile. Only one arm 10a of the spring 10 extends beyond the blocking lever 8.

Above the primary-position pawl 6 is arranged a first-position pawl. The first-position pawl is also pivotally mounted on the shaft 7 and can, therefore, also be rotated around the axis 7. The outline 13 of the first-position pawl is indicated with dots. The first-position pawl 13 comprises a pin 14, which extends down from the first-position pawl in the direction toward the housing wall 1. At this pin 14, which is attached to the first-position pawl, is disposed the other arm 10a of the spring 10. The other arm of the spring 10 pushes toward the direction of the pin 14 along the arrow 15. In the primary position, the pin 14 abuts a lateral contour area of the blocking lever 8. When the first-position pawl 13 is turned in the direction of the arrow 16, the pin 14 causes the blocking lever 8 to be rotated out of the blocking position. The spring arm 10a can follow the movement of the stop or the pin 14 such that the rotation of the first-position pawl 13 is not limited by an opposing force, which would otherwise originate from the spring arm 10b. This facilitates the rotation of the blocking lever 8 by the first-position pawl 13 out of the blocking position. When the blocking lever 8 is moved from the blocking position, the primary-position pawl 6 is pushed away by the catch from its shown notched position. Additionally or alternatively, the lateral contour area of the first-position pawl 13 strikes a protruding pin 17 serving as a stop, which is attached to the primary-position pawl 6. This pin is made of plastic and is formed as a single piece with the plastic portion 6a. This has the consequence that the primary-position pawl 6 is rotated out of the shown notched position and releases the catch. The catch then pivots in the direction of the arrow 22 toward the open position and ultimately sets free the locking pin 3. The corresponding door or gate can then be opened.

The catch exerts a sufficiently great pressure on the primary-position pawl primarily at the time when a door seal pressure transfers high opening forces onto the catch. However, when the door seal pressure is relatively low, a problem may arise in that the catch does not transfer a sufficiently large torque onto the primary-position pawl and the primary-position pawl cannot be pushed out of the notched position. The aforementioned lateral contour area of the first-position pawl ensures that the primary-position pawl is reliably rotated out from its notched position, even when a too low of a door seal pressure is applied. This embodiment of the invention described herein is technically simpler than the solution described in DE 10 2007 003 948 A1.

The first-position pawl 13 can also lock the catch 4 when a protruding pin 18 of the catch 2 strikes against the lateral contour area 19 of the first-position pawl 13 and thus prevents the rotation of the pawl toward the open position in accordance with the arrow 22. The first-position pawl 13 is preferably biased by a spring (not shown) in the direction toward its locked position. One arm of this spring then pushes against an end 21, which is perpendicular to the wall 1. A protruding pin 20, which serves as a stop and is secured to the housing wall 1, prevents further rotation of the first-position pawl beyond its notched position. This pin 20 is, for reasons of stability, preferably made of metal.

The primary-position pawl 6 is also made of metal and is preferably not directly spring loaded. The primary-position pawl 6 is instead appropriately rotated alone by other components, particularly by the rotation of the catch 4, the first-position pawl 13, and/or the blocking lever 8, e.g., by the rotation of the blocking lever 8 into a notched position (primary position). The corresponding rotation of the blocking lever is caused by the supplied bias of the spring 10.

In order to move the primary-position pawl, with the help of the blocking lever, suitably into a notched position, the hook-like endings 6b and 8a have been found to be particularly suitable. The head of the hook 6b of the primary-position pawl acts as a stop for the catch. The tip of the hook 6b is blocked in the primary position by the head of the hook 8a. If the blocking lever 8 is rotated out of the blocked position, then the two hooks 6b and 8a interlock. The top end 6b finally pushes the hook 8a so far outward that the lever arm 8b of the pin 14 is lifted, whereby the tension of the spring 10 is increased (see also FIG. 3). The rotation of the first-position pawl 13 is further facilitated because the first-position pawl 13 no longer transfers its moment of inertia onto the blocking lever 8. The movement of the tip 6b or the primary-position pawl 6, which is responsible for moving the arm 8b away from the pin 14, is then caused by the catch, which rotates toward the open position, wherein the lateral contour area 4a presses against the then-adjacent lateral contour area of the hook 6b. As shown, the end portion 4b of the contour area 4a is angled or bent outwards (as seen from the catch) in order to rotate the primary-position pawl and thereby to rotate the hook 6b, particularly far along the direction indicated by arrow 16. As a result, the lever arm 8b is moved particularly far away from the stop 14 and a desirable bias is then provided by the spring 10. Advantageously, the tip of the hook 6b is longer than the tip of the hook 8a in order to provide a particularly large bias of the spring 10. Because the hook 8a does not have to achieve such an effect, the hook 8a is relatively short. All of this ensures a particularly reliable operation.

If the catch is rotated from the open position toward the closed position up to the first position, the first-position pawl then snaps into its notched position, wherein the first-position pawl is then rotated opposite to the direction of the arrow 16 until a further rotation is limited by the stop 20, as shown in FIG. 1. In this first position, the corresponding lateral contour section of the hook 6b still lies against the lateral contour area 4a. This blocks the rotation of the blocking lever 8 such that the arm 8b is moved in the direction of the arrow 11. The bias of the spring 10 is then further increased in a desired manner. When the lateral contour portion 4a, extending from the corner point 4b to the corner point 4c, ultimately sets free the primary-position pawl 6, a high biasing force is provided in order to reliably move the primary-position pawl into a notched position when the corresponding vehicle door or hatch is closed.

In order to rotate the first-position pawl out of its notched position, so as to unlock the lock, the first-position pawl is stricken within the grip area 21 and rotated. The striking and rotating of the first-position pawl 13 can be done manually or with the help of a motor. Since the first-position pawl can also be rotated backwards by a motor, a spring that biases the first-position pawl toward a notched position is not mandatory. For performance and safety reasons, the provision of such a spring is, however, beneficial.

FIG. 2 shows the lock of FIG. 1. However, the first-position pawl 13 is now shown (is not transparent). Therefore, the first-position pawl 13 partially covers inter alia the primary-position pawl 6. FIG. 2 illustrates that the area 21 is perpendicular upwards with respect to the wall 1 in order to strike the first-position pawl without enlarging the size of the lock and in order to rotate it out of a notched position by means of a motor. Furthermore, the first-position pawl is biased toward a notched position by a pre-tensioned spring arm 40a of a torsional spring 40, which arm rests against the perpendicular end area 21.

FIG. 3 shows the position of the catch 4, the primary-position pawl 6, the blocking lever 8, the spring 10, and the locking pin 3 in the open position of the lock. In addition, the position of the first-position pawl 13 is outlined transparently. The locking pin 3 can now be moved out of the inlet slot and the attached door or hatch can be opened. The tip of the hook 6b of the primary-position pawl pushes the hook-shaped lever arm 8a and thereby also the lever arm 8b of the blocking lever 8 far to the outside. The spring arm 10b is thus also pushed wide to the outside and the spring 10 provides a strong bias. The lateral tip 4b of the lateral contour 4a, which tip extends to the corner point 4c, ensures that the lever 8b is pushed by the hook 6b particularly far to the outside and so that the spring 10 becomes particularly strongly tensioned. FIG. 3 also illustrates that the first-position pawl 13 does not contribute to the increased tension of the spring 10.

When a vehicle door, through which vehicle occupants enter and exit, or a hatch with the locking pin 3, is slammed, the locking pin 3 turns the catch 4 toward the closed position. The back side of the hook 6b then slides along the lateral contour 4a. This leads to an initial slight decrease in the tension of the spring 10 because at that time, the blocking lever 8 also initially rotates slightly backwards in the direction toward a blocked position. However, the pin-shaped stop 14 slides also in the direction toward the lateral contour 19 of the first-position pawl 13 and ultimately sets free the first-position pawl 13 such that the first-position pawl 13 rotates into a notched position due to a bias, which again increases the tension of the spring 10.

FIG. 4 shows an intermediate position between the open position and closed position of the catch 4. If the catch 4 is rotated somewhat further in the direction toward the closed position by the locking pin 3, the first-position pawl 13 snaps into a notched position and increases the tension on the spring 10. The back side of the hook 6b is pressed against the lateral contour area 4a of the catch 4 by the lever arm 8a of the blocking lever 8, which is biased by the spring 10.

Number	Date	Country	Kind
10 2009 026 920.7	Jun 2009	DE	national
10 2010 003 483.5	Mar 2010	DE	national

LOCK HAVING RESTRICTED GUIDANCE FOR A PAWL

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