GB2293961A

GB2293961A - Apparatus for actuating a locking pawl of a safety belt retractor

Info

Publication number: GB2293961A
Application number: GB9520989A
Authority: GB
Inventors: Martin Specht
Original assignee: ICSRD RUECKHALTESYSTEME fur F
Current assignee: ICSRD RUECKHALTESYSTEME fur F
Priority date: 1994-10-14
Filing date: 1995-10-13
Publication date: 1996-04-17
Also published as: GB9520989D0; ES2128209B1; ITBZ950064A1; ITBZ950064A0; FR2725672B1; FR2725672A1; DE4436811A1; IT1282444B1; ES2128209A1

Description

2293961 1 APPARATUS FOR ACTUATING A WCKING PAWL FOR LOCKING A IRFIX REEL

OF A SAFETY 1FIEL1 RETRACTOR The invention relates to apparatus for actuating a locking pawl for locking a belt reel of a safety belt retractor to prevent belt extension.

In such apparatus, prior to locking of the belt reel, the belt webbing can be tensioned in the belt winding-on direction by a tensioner drive.

A coupling is described in German Patent Specification No 43 27 134, with which the tensioning movement produced by a tensioner drive can be transmitted by way of a coupling disc with coupling elements mounted thereon for a rotary drive in the belt winding-on direction, to the belt reel of a belt retractor.

According to the invention there is provided apparatus for actuating a locking pawl for locking a belt reel of a safety belt retractor to prevent belt extension, wherein prior to locking of the belt reel the belt webbing can be tensioned in the belt winding-on direction of a tensioner drive, and the locking pawl can be activated by a component which is moved upon tensioning of the safety belt for locking engagement into the belt reel.

Such apparatus can ensure that the tensioned belt webbing is securely locked by the locking pawl to prevent belt webbing extension.

It can also guarantee that, independently of the functioning of the sensor device associated with the belt retractor, reliable engagement of the locking pawl into the belt reel of the safety belt retractor is ensured after tensioning of the belt webbing in the belt winding-on direction.

That can be effected by an actuating member which moves the locking pawl into a position of engagement with the belt reel being movable out of a rest position upon tensioning of the safety belt. For that purpose the actuating member can be biased in the actuating direction.

There may be provided a holding member which holds the locking pawl in a deactivated position with a biasing effect which is overcome by the actuating member.

Upon activation of the locking pawl it can come out of a rest position into a ratchet contact condition with one or both blocking tooth arrangements on the belt reel. The 1) tensioning movement is not adversely affected thereby. When the tensioning movement is concluded and a rotary movement-initiating force is applied by the belt webbing to the belt reel in the belt extension direction, the locking pawl comes into engagement directly with the blocking tooth arrangement on the belt reel.

The component which is moved upon tensioning of the safety belt may be for example a shear element which is formed on the coupling disc as described in German Patent Specification No 43 27 134 and a holding element by which the actuating member is held in the rest position, removed for example by shearing off, so that the actuating member can activate the locking pawl for locking engagement into the belt reel.

The invention is diagrammatically illustrated by way of example in the accompanying drawing, which is a side view of parts of a coupling arrangement which corresponds for example to the coupling arrangement of the embodiment shown in Figure 10 of German Patent Specification No 43 27 134. A belt reel 3 is mounted with a fixed belt reel axis 15 on the frame of the belt retractor. A coupling disc 16 is also coaxially rotatably mounted on the frame of the belt retractor. Provided on the coupling disc 16 are coupling elements 13 of which one coupling element is shown.

In the case of the tensioning drive, the coupling elements 13 are moved radially outwardly by the rotary movement of the coupling disc 16 and come into coupling engagement with a coupling tooth arrangement 14 on the belt reel 3.

In the rotary movement of the coupling disc 16 which is caused by a tensioner drive (not shown in greater detail) by way of a pull cable which acts on the coupling disc 16, a component 2 which is formed on the coupling disc 16 is also moved, more specifically in the anti-clockwise direction in the Figure. A holding element in the form of a holding pin 8 with which the actuating device for a locking pawl 1 is held in the rest position shown in the Figure can be sheared off by the moved component 2 which can be in the form of a shear element. As will be described in detail hereinafter the locking pawl 1 comes into ratchet engagement with a blocking tooth arrangement 6 on the belt reel 3.

In the embodiment shown in the Figure the locking pawl 1 is held in the rest position by a resilient holding member 5. In that rest position the locking pawl 1 is 3 out of engagement with the blocking tooth arrangement or arrangements 6 on the belt reel 3. An actuating member 4 serves to actuate the pawl 1. That actuating member 4 which is of a wcdge-like configuration is subjected to the biasing force of a spring 7 which can be for example in the form of a Icaf spring. The spring 7 and the actuating member 4 arc held in the rest position by the holding clement which is in the form of a holding pin 8.

As already mentioned the holding pin 8 can be in the form of a shear pin and can be sheared off upon tensioning of the safety belt by the moved component 2. By virtue of the effect of the spring 7, an intermediate lever 9 is pivoted by the actuating member 4 so that the locking pawl 1 is moved against the spring force of the holding member 5 against the blocking tooth arrangement 6 of the belt reel 3. That position is shown in broken line in the Figure.

In the case of the tensioning drive, the coupling disc 16 which is in force-locking engagement with the belt rccl 3 by way of the coupling elements 13 is rotated in the anti-clockwise direction so that the belt reel is also rotated. When that happens the belt webbing is wound on to the recl. In that tensioning movement, the front engagement portion of the locking pawl 1 is in ratchet engagement with the blocking tooth arrangement 6.

The locking pawl 1 can be in the form of a double pawl which comes into engagement with both blocking tooth arrangements 6 on the belt rcel 1, as is shown for example in German Utility Model Specification No 94 13 087.6 or in the embodiment shown in Figure 10 of German Patent Specification No 43 27 134.

A common holding ring 10, for example of plastics material, is provided for the spring 7, the intermediate lever 9 and the holding member 5. The holding ring 10 is fitted into the housing 11. The holding ring 10 can be fixed to the housing 11 by means of a fixing pin 12. The holding pin 8 can also be fixed to the housing 11 for holding the spring 7 and the actuating member 4 in the rest position thereof.

When the tensioning movement during which the locking pawl 1 ratchets against the blocking tooth arrangement 6 and the rotary movement of the belt reel 3 arc ended, upon reversal of the rotary movement of the belt reel 3 the locking pawl 1 inevitably moves into its definitive locking position with one of the teeth of the 4 blocking tooth arrangement 6. If the locking pawl is in the form of a double pawl, locking pawls come into engagement with the blocking tooth arrangement 6, at both sides of the belt webbing. In that way the belt reel is locked against rotary movement in the direction of extension of the belt webbing and the body of the vehicle occupant is held fast in the vehicle seat by the tensioned belt webbing.

Claims

1. Apparatus for actuating a locking pawl for locking a belt reel of a safety belt retractor to prevent belt extension, wherein prior to locking of the belt recl the belt webbing can be tensioned in the belt winding-on direction of a tensioner drive, and the locking pawl can be activated by a component which is moved upon tensioning of the safety belt for locking engagement into the belt reel.

2. Apparatus according to claim 1, wherein an actuating member which moves the locking pawl into a position of engagement with the belt reel is movable out of a rest position upon tensioning of the safety belt.

3. Apparatus according to claim 2, wherein the actuating member is biased in the actuating direction.

is

4. Apparatus according to claim 2 or claim 3, wherein there is provided a holding member which holds the locking pawl in a deactivated position with a biasing effect which is overcome by the actuating member.

5. Apparatus according to any one of claim 1 to 4, wherein the locking pawl comes into its definitive locking position by reversal of a movement caused by the tensioner drive.

6. Apparatus according to claim 5, wherein the locking pawl comes into definitive locking engagement with a blocking tooth arrangement on the belt reel by reversal of the rotary movement of the belt reel, which is caused by the tensioner drive.

7. Apparatus according to any one of claims 1 to 6, wherein the locking engagement of the locking pawl in the belt reel can be activated by a tensioning movement which is transmitted to the belt recl.

6

8. Apparatus for actuating a locking pawl for locking a belt reel of a safety belt retractor to prevent belt extension substantially as hereinbefore described and illustrated with reference to the accompanying drawing.