GB2104142A

GB2104142A - Door lock for motor vehicles

Info

Publication number: GB2104142A
Application number: GB08218132A
Authority: GB
Inventors: Hans-Josef Deischl; Hermann Werner Kurth; Frank Kleefeldt; Kurt Raffelsiefer
Original assignee: Kiekert AG
Current assignee: Kiekert AG
Priority date: 1981-07-08
Filing date: 1982-06-23
Publication date: 1983-03-02
Also published as: IT8222250A0; FR2509357B1; JPS5811278A; GB2104142B; DE3126810A1; JPH0216437B2; IT1151685B; DE3126810C2; FR2509357A1

Abstract

A door lock for motor vehicles has a forked latch (1) with a half-lock arm (3) and a full-lock arm (4), and a catch (2) with a lever arm (5) and hook (6) which engages first behind the half- lock arm (3) in a half-locked position and then behind the full-lock arm (4) in the fully locked position, the forked latch (1) and the catch (2) being so shaped that as the forked latch (1) rotates out of the half-lock position into the full-lock position, the half-lock arm (3) remains in controlling contact with the catch lever arm (5) and guides the hook (6) into position over the full-lock arm (4). In this way, impact collisions between the hook (6) and the full-lock arm (4), which would interfere with the control of door closure, are avoided. <IMAGE>

Description

SPECIFICATION Door lock for motor vehicles This invention relates to a door lock for motor vehicles, having a forked latch and a catch, in which the forked latch has a half-lock arm and a full-lock arm, the catch has a lever arm and a hook attached thereto, and as the vehicle door is closed the hook on the catch engages first against the half-lock arm in the half locked position and then against the full-lock arm in the fully locked position.

In known door locks for motor vehicles, the catch is driven through its closure movement first by the half-lock arm and then by the full-lock arm, and they act directly on the hook rather than on the lever arm itself. During the closure movement, a stop face on the half-lock arm encounters a corresponding thrust face on the hook, the hook slides on to the half-lock arm and then it drops in behind the half-lock arm; in general, the catch is spring loaded and the spring brings about or supports the engagement movement. Later during the closure movement of the forked latch, a stop face on the full-lock arm encounters a corresponding thrust face on the hook, the hook slides on to the full-lock arm and then it drops behind the full-lock arm. As a result, the hook experiences as it were two collisions, first on the half-lock arm and then on the full-iock arm.

Although the aforementioned components in such door locks for motor vehicles are usually made from materials of a nature and strength such that these collisions do not lead to premature failure, the impacts between the full-lock arm and the hook nevertheless impair the functional reliability of the lock. If a vehicle door is slammed so rapidly that it rebounds, the hook may not drop in behind the full-lock arm. In fact, the impacts bring about a very rapid acceleration of the catch, which rebounds over a corresponding distance against the action of the loading spring. In such circumstances, premature failure can still occur.

The object of the invention is to provide a motor vehicle door lock of this type but in which impact collisions no longer occur between the hook and the full-lock arm.

According to the present invention, the forked latch and the catch are so shaped that as the formed latch rotates out of the half-lock position into the full-lock position the half-lock arm remains in controlling contact with the catch lever arm and guides the hook into position over the full-lock arm.

The components are preferably shaped and assembled so that the half-lock arm leads the hook on to the full-lock arm, and the hook is preferably caused to drop in behind the full-lock arm under the action of a loading spring for example as the forked latch completes its rotation. However, it is possible to adopt a construction in which the half-lock arm automatically pushes the hook in behind the fulllock arm. The two possibilities can even be combined, so that both the half-lock arm controls the catch lever arm and the full-lock arm controls the hook.For outstanding simplicity with respect to kinematic and dynamic relationships, the forked latch and the catch preferably have pivots which are staggered in the direction of the closure movement of the forked latch, the pivot for the catch being disposed above and beyond the pivot for the forked latch, in the closure direction of the forked latch.

The accruing advantages are to be seen in that there is no longer any significant impact between the hook and full-lock arm. This enhances its functional reliability. Even if a vehicle door is slammed with very great force, the engagement of the hook behind the full-lock arm qn the forked latch is guaranteed.

An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a side elevation of part of a motor vehicle door lock in accordance with the invention; Figure 2 shows the door lock of Figure 1 in another functional position; and Figure 3 shows the door lock of Figure 1 in yet another functional position.

In the motor vehicle door lock shown in the Figures, the components of significance within the scope of the invention are a forked latch 1 and a locking catch 2. The forked latch 1 has a halflock arm 3 and a full-lock arm 4. The catch 2 consists of a lever arm 5 and a hook 6 attached thereto. As the vehicle door is closed, ,the halflock arm 3 first engages behind the hook 6 on the catch 2, in the half-locked position shown in Figure 1. Then the full-lock arm 4 engages behind the hook 6 on the catch 2, in the fully locked: position shown in Figure 3. The forked latch 1 is actuated by a locking pin 7, as can be seen by comparing Figures 1 to 3. The door lock is usually built into the vehicle door 8, and the locking pin 7 is mounted on the door frame. The kinematic relationships are indicated by the arrows inscribed in Figures 1 and 2.

Referring to Figure 2 in particular, it will be seen that as the forked latch 1 rotates out of the half-lock position into the full-lock position the half-lock arm 3 remains in controlling contact with the catch lever arm 5 and guides the hook 6 into position over the full-lock arm 4 so that there is no impact collision between the hook 6 and the full-lock arm 4. Figure 2 shows a series of intermediate positions, a, b and c, distinguished by differently drawn lines. The arrangement is such that the half-lock arm 3 leads the hook 6 on to the full-lock arm 4. It could additionally push it in behind the full-lock arm 4. It will also be seen from Figure 2 that the half-lock arm 3 controls the catch lever arm 5 until the full-lock arm 4 can control the hook 6.

The forked latch 1 and the catch have pivots 9 and 10 which are staggered in the direction of the closure movement of the forked latch 1. The kinematic relationships just described and the resulting dynamic relationships are outstandingly simple, because the pivot 9 for the catch 2 is disposed above and beyond the pivot 10 for the forked latch 1.

Claims

1. A door lock for motor vehicles, having a forked latch and a catch, in which the forked latch has a half-lock arm and a full-lock arm, the catch has a lever arm and a catch attached thereto, and as the vehicle door is closed the hook on the catch engages first against the half-lock arm in the half-locked position and then against the fulllock arm in fully locked position, the forked latch and the catch being so shaped that as the forked latch rotates out of the half-lock position into the full-lock position the half-lock arm remains in controlling contact with the catch lever arm and guides the hook into position over the full-lock arm.

2. A motor vehicle door lock as in Claim 1, wherein the half-lock arm leads the hook on to the full-lock arm.

3. A motor vehicle door lock as in Claim 2, wherein the hook is caused to drop in behind the full lock arm under the action of a loading spring as the forked latch completes its rotation.

4. A motor vehicle door lock as in Claim 1, wherein the half-lock arm pushes the hook in behind the full-lock arm.

5. A motor vehicle door lock as in Claim 1, wherein the half-lock arm controls the catch lever arm until the full-lock arm can control the hook.

6. A motor vehicle door lock as in any one of Claims 1 to 4, wherein the forked latch and the catch have pivots which are staggered in the direction of the closure movement of the forked latch, the pivot for the catch being disposed above and beyond the pivot for the forked latch in the closure direction of the forked latch.

7. A motor vehicle door lock substantially as hereinbefore described with reference to the accompanying drawings.