GB2310958A

GB2310958A - Lock for a safety belt

Info

Publication number: GB2310958A
Application number: GB9704453A
Authority: GB
Inventors: Dirk Quardt; Thomas Breer
Original assignee: BURGESS GmbH
Current assignee: BURGESS GmbH
Priority date: 1996-03-04
Filing date: 1997-03-04
Publication date: 1997-09-10
Anticipated expiration: 2017-03-04
Also published as: DE19608223A1; SE9700771D0; GB9704453D0; FR2745537A3; SE9700771L; GB2310958B; FR2745537B3

Description

1 Belt Lock for a Saf@jy Belt of a People Mover 2310958 The invention

relates to a belt lock for a safety belt of a "people mover", comprising a lock housing into which a tongue-shaped lock part can be inserted and can be locked or engaged there, and provided with an electrical switch which is actuable by the insertion movement of the tongue-shaped lock part.

At the present time it is known in principle to provide the belt lock of a safety belt with an electrical switch in order that an electrical circuit can be closed by the closure of the belt lock by way of the actuation of the switch, the circuit illuminating for example a control light or the like or opening a circuit in order for example to extinguish a control light.

When the belt lock is opened, the switch is in turn actuated, for example by a restoring member for the actuator of the switch.

The electrical switch used for this task has hitherto been a normal pushbutton switch, namely a microswitch such as is found for performing widely varying tasks in the field of motor-car electrics.

Because of the fiu-ther development of safety systems in a people mover and the associated electronicization in this field, it would be desirable if the switch present in the belt lock could be employed for further tasks, namely in particular for control tasks.

For example, in the case of a passenger car equipped in the modem manner, it would no longer be merely a matter of interest as to whether the belt lock of a safety belt is closed and therefore the person in question adequately secured, but a modern passenger car frequently has finther retaining systems as well, for example an airbag, 2 the operation of which should be controlled differently according to circumstances, depending upon whether the person to be secured by the flirther retaining system is additionally strapped in or not. In the case of a further retaining system, different functions would therefore have to be optionally actuated as a function of the state of closure of the belt lock..

Such a task, however, can be performed with a microswitch in the belt lock only with an increased outlay and at greater cost. In particular, one control circuit - even if simple in an individual case - should in addition already have been provided in the belt lock, and is in turn actuated by the actuating switch in the desired manner. It is disadvantageous, however, to. fit a bar of this type having a conventional microswitch depending upon the space available - in the region of the belt lock, since such a switchcircuit combination is limited in its possibilities of application. In addition, an "insertion shape" of this type is susceptible to mechanical stresses and environmental effects.

The object of the invention is therefore further to develop a belt lock of the type defined in the introduction, in such a way that even relatively sophisticated control functions can be carried out automatically depending upon the state of closure of the belt lock.

This object is attained according to the invention in that the electrical switch is constructed in the form of a sliding switch with an integrated printed circuit board capable of being provided with switching members, in such a way that the sliding switch has contacts which can be displaced onto different conductive areas of the printed circuit board, in which case the direction of displacement coincides with the insertion movement of the tongue-shaped lock part.

By means of the invention, therefore, a switching device is advantageously provided in a belt lock, in which [switching device] the actual switch and the printed circuit board are combined in a particularly functional and space-saving menner, in which case a very high degree of switching reliability and precision can be ensured at 3 the same time, namely with respect to taking on relatively sophisticated control tasks for which the printed circuit board can be provided with suitable conductor tracks and and can be equipped with suitable switching members. It is even possible for two or more electrically separate circuits to be actuated or controlled by one switch.

According to a flu-ther development of the invention the switch comprises a restoring member, preferably a spring, with a restoring action in the direction of the withdrawal movement of the tongue-shaped lock part when the belt lock is opened.

If - during the insertion of the tongue-shaped lock part, i.e. during the closure of the belt lock - the switch is actuated by the insertion movement itself, it would would be disadvantageous if during the opening of the belt lock the tongue-shaped lock part had to perform a reversed actuating movement during its withdrawal movement by a sort of entrainment device. For this purpose, it is advantageous and sufficient to provide a restoring member, preferably a relatively simple restoring spring, which in turn because of the potential energy stored therein - is able to produce a corresponding restoring movement of the switch when the belt lock is opened.

According to the invention the switch comprises an actuating member which is preferably in the form of a tappet which is orientated parallel to the insertion direction of the tongue-shaped lock part, i.e. it can convert a force acting in the insertion direction in order to actuate the switch.

Preferably, however, in order to actuate the switch, the tongue-shaped lock part does not press directly on the tappet, since for reasons of space a suitable arrangement of the switch would be possible only with difficulty and would also be disadvantageous, but an indirect actuation of the tappet is carried out in that an ejector, which is provided for ejecting the tongue-shaped lock part when the belt lock is opened and which is movable in the insertion direction of the tongue-shaped lock part, is provided as a means for transmitting the actuating force in order to actuate the tappet when the tongue-shapeA lock part is inserted. An ejector of this type is usually present in a belt 4 lock in any case, in order to assist the withdrawal movement of the tongue-shaped lock part when the belt lock is opened.

According to a fiz&er development of the invention, the ejector comprises an actuating arm which is orientated substantially transversely to the tappet and which during the movement of the ejector in the insertion direction of the tongue-shaped lock part is guided in a guide path leading to the free end of the tappet.

An additional fin-ther development of the invention provides that a bridging member, preferably a spring, which bridges the distance between the actuating arm and the free end of the tappet, is arranged in the guide path. This step too allows the switching device according to the invention to be positioned in the belt lock in a flinctionally and spatially appropriate manner.

The printed circuit board is preferably positioned on a longitudinal narrow side of the lock housing and arranged parallel thereto, Le. likewise in a spatially and functionally appropriate manner. In this connexion it should be additionally noted that the lock housing is generally the metallic part into which the tongue-shaped lock part is inserted. The lock housing itself is generally additionally encased with shells of plastics material, so that a space protected from contact is available for the switching device between the plastics-material shells and the metallic lock housing. In addition, the plastics-material shells can be sealed off, for example with an elastomer seal.

An embodiment, from which further inventive features may be seen, is illustrated in the drawing, in which Fig. 1 is a view, partly in section, of a lock housing of a belt lock according to the invention with a switching device; Fig. 2 shows the switching device with a belt-lock ejector according to Fig. 1; Fig. 3 shows the switching device according to Fig. 2 with the cover removed; Fig. 4 shows the switching device according to Fig. 3 with the guide path raised, and Fig. 5 shows the actuating device of the switching device according to the preceding Figures with the cover of the switching device.

Fig. 1 shows the lock housing 1 of a belt lock according to the invention for a safety belt of a people mover.

The lock housing, which is preferably produced from metal, has a substantially U-shaped cross-section which is formed by a base 2 and two longitudinal narrow sides 3 arranged opposite each other thereon. In the illustration according to Fig. 1 the longitudinal narrow side 3 in front in the drawing is shown only in part, in order to allow a view into the interior of the lock housing. In itself the front longitudinal narrow side 3 is formed precisely mirror-symmetrically to the rear longitudinal narrow side 3 which is shown complete.

On the basis of the front longitudinal narrow side 3 shown partly cut away, a bowshaped ejector 4 or an ejector formed in the shape of a large n is visible in the interior of the lock housing 1, the ejector 4 being guided displaceably in slots 5 in the longitudinal narrow sides 3 in the direction of the longitudinal axis of the lock housing 1. The insertion direction of a substantially tongue-shaped lock part (not shown in the Figures) into the lock housing 1 - in order to be locked or engaged there and thereby to lock the belt lock - corresponds to the said direction of movement of the ejector 4.

The lock housing 1 is encased in shells of plastics material in a conventional manner. In addition, a release button for unlocking the tongue-shaped lock part, i.e. for opening the belt lock, is provided on the lock housing. In the case of a three-point safety belt in the region of a front seat of a passenger car, the shells of plastics material containing the lock housing 1 are usually secured to the free end of a belt-buckle anchorage which is secured to a central console between the two front seats on the bodywork of the vehicle. The tongue-shaped lock part is secured to the belt itself and for this purpose has a lug through which the belt is drawn.

6 In the case of two-point safety belts the plastics-material casing containing the lock housing 1 can be secured to one belt end, whilst the tongue-shaped lock part is secured to another belt end. Two-point safety belts of this type are used for example on rear seats of motor vehicles, and also on aeroplane seats.

When the belt lock is opened, i.e. when unlocking and withdrawing the tongueshaped lock part out of the lock housing 1, the ejector 4 - which is spring-loaded in a conventional manner - assists the withdrawal movement of the tongue-shaped lock part, i.e. ejects the unlocked tongue- shaped lock part out of the lock housing 1 virtually automatically.

The ejector is provided at the free ends thereof with end arms 6 extending outwards transversely to its direction of movement and engaging in the slots 5. In addition, the ejector 4 ensures that the belt lock does not lock again.

A switching device 7, which contains an electrical switch, is arranged on the front longitudinal narrow side 3 of the lock housing 1 shown only in part in Fig. 1. The electrical switch has an actuating member in the form of a tappet which is surrounded by a guide path 8. One of the end arms 6 of the ejector 4 is not only guided in the corresponding slot 5 in the longitudinal narrow side 3, but is also guided as an actuating arm - for actuating the tappet of the switching device 7 - in the guide path 8 in the shape of a U-profile.

In addition, the switching device 7 comprises a printed circuit board 9 which is protected by a cover 10 and can be provided with conductor tracks and switching members for an electronic circuit. Electrical cables 11 or wires are arranged on the printed circuit board 9.

Fig. 2 essentially shows the switching device 7 with the guide path 8 thereof and the ejector 4 guided thereon with an end arm 6 in a clearer illustration while omitting 7 fin-ther components for the sake of simplicity.

The same components are each designated With the same reference numerals in the said Fig. 2, and also in the following Figures, as in Fig. 1.

Fig. 3 shows the switching device 7 with the guide path 8 thereof according to Fig. 2 with the cover 10 removed.

Since the cover has been removed in Fig. 3, the interior of the switching device is visible. In particular, the printed circuit board 9 may be seen, which comprises conductor track 12 and conductive faces 13 connected thereto and is provided with switching members 14, for example resistors or the like.

The actual electrical switch 15 is constructed in the form of a sliding switch and is actuated by way of a tappet 16 projecting in the guide path 8. The switch 15 comprises two contact tongues 17 which form a contact bridge and which are produced from metal and rest resiliently on conductive faces of the printed circuit board 9 and can be pushed by a sliding movement onto other conductive faces 13 in order to change the switch setting.

In addition, the switch 15 has a restoring spring 18 which triggers or performs an automatic return movement after the release of the tappet 16 and which is supported on the cover 10 or on a side of the edge of the cover 10.

Fig. 4 shows the switching device 7 according to Fig. 3, but this time with the guide path 8 removed. Since the guide path 8 has been removed in this illustration, the tappet 16 can now be seen in its complete design. In addition, it is possible to see that a bridging spring 19 is arranged as a bridging member in the guide path 8 and is supported at the free end of the tappet 16, in order to bridge the distance between the said firee end of the tappet 16 and the end arm 6 of the ejector 4 constructed in the form of an actuating arm.

8 Fig. 5 shows the switch 15 in the arrangement thereof in the cover 10, i. e. with the printed circuit board 9 removed as it were.

In the said Fig. 5 it may be seen in particular how the restoring spring 18 is supported on a side of the edge of the cover 10, in order to be able to perform a return movement of the switch 15 with the tappet 16 released.

9 Clahns:

1. A belt lock for a safety belt of a people mover, comprising a lock housing into which a tongue-shaped lock part can be inserted and can be locked or engaged there, and provided with an electrical switch which is actuable by the insertion movement of the tongue-shaped lock part characterized in that the electrical switch is constructed in the form of a sliding switch with an integrated printed circuit board capable of being provided with switching members, the sliding switch has contacts which can be displaced onto different conductive areas of the printed circuit board, wherein the direction of displacement coincides with the direction of the insertion movement of the tongue-shaped lock part.

Claims

2. A belt lock according to Claim 1, characterized in that the switch

comprises a restoring member, preferably a spring, with a restoring action in the direction of the withdrawal movement of the tongue-shaped lock part when the belt lock is opened.

3. A belt lock according to Claim 1 or 2, characterized in that the switch comprises as an actuating member a tappet orientated parallel to the insertion direction of the tongue-shaped lock part.

4. A belt lock according to Claim 3, characterized in that an ejector, which is provided for ejecting the tongue-shaped lock part when the belt lock is opened and which is movable in the insertion direction of the tongue-shaped lock part, is provided as a means for transmitting the actuating force for actuating the tappet when the tongue-shaped lock part is inserted.

5. A belt lock according to Claim 4, characterized in that the ejector comprises an actuating arm which is orientated substantially transversely to the tappet and which during the movement of the ejector in the insertion direction of the tongueshaped lock part is guided in a guide path leading to the free end of the tappet.

6. A belt lock according to Claim 5, characterized in that a bridging member, preferably a spring, which bridges the distance between the actuating arm and the free end of the tappet, is arranged in the guide path.

7. A belt lock according to one of the preceding Claims, characterized in that the printed circuit board is preferably arranged on a longitudinal narrow side of the lock housing and parallel thereto.

8. A belt lock substantially as herein described with reference to the accompanying drawings.