GB2208264A

GB2208264A - Clamping device

Info

Publication number: GB2208264A
Application number: GB8818090A
Authority: GB
Inventors: Klaus Struck
Original assignee: Autoflug GmbH
Current assignee: Autoflug GmbH
Priority date: 1987-07-30
Filing date: 1988-07-29
Publication date: 1989-03-22
Anticipated expiration: 2008-07-29
Also published as: ZA885568B; FR2618740A1; IT8821470A0; DE3725223A1; DE8717599U1; SE8802642D0; FR2618740B1; SE8802642L; GB2208264B; GB8818090D0; IT1227431B

Description

1 - OY 53 112B 17 220P264 Clamping device The invention relates to a

clamping device for a safety belt system, e.g. for use in motor vehicles.

It is known from EP-0 186 105 to provide a clamping device having a clamping jaw fixed to a housing and a movable clamping jaw controlled by sensors. The clamping jaws are arranged such that the safety belt may be guided therebetween and the movable clamping jaw has a separate clamping plate which, in the clamped position, rests parallel to the fixed clamping jaw and to the belt. The clamping plate is rotatably mounted by means of a hinge on the movable clamping jaw which is in turn pivotally movable.

An arrangement of this kind is intended essen- tially to ensure that there is a clamping action over the entire area between the clamping surface of the clamping plate and the belt or the fixed clamping jaw. A disadvantage of this known arrangement in which the clamping plate and movable clamping law are rotatable relative to each other, aided by the action of an additional spring, is the fact that the parts have to be manufactured separately and are correspondingly laborious to mount.

Although German utility model 84 37 581, for example, proposes an integral, sealed construction for the movable clamping jaw with clamping plate and clamping teeth provided directly thereon, this construction has the disadvantage of requiring very great accuracy of measurement and fitting of the parts of the clamping device in order to avoid operational defects such as rubbing of the clamping members on the belt or a reduction in the braking strain; however, such high recruirements on the accuracy of dimensions and fittinq of the parts and their assembly can scarcelly be met in mass production of the kind used for such components.

According to the invention there is provided clamping device for a safety belt system, havinq housing, a clamping iaw fixed relative to the housing, a movable clamping jaw arranged to be controlled by at least one sensor and located such that a safety belt may be guided between the clamping jaws, the movable clamping law having a clamping plate which is arranged such that in the clamped position it is disposed parallel to the fixed clamping jaw and the belt, wherein the clamping plate is integral with the movable clamping jaw and, under a clamping load, can change its position relative to the movable clamping iaw by deformation.

An advantage of such an arrangement is that the movable clamping law including the clamping plate can be manufactured in a single operation, since the parts which are integral with one another can be manufactured in one tool, for example by injection moulding of plastics, or from an extruded aluminium profile or as a die-cast aluminium part. As a result, advantageously, it is not necessary to pre-assemble the clamping device by movably mounting the clamping plate on the movable clamping jaw, and the parts required for such movable mounting of the clamping plate such as springs, bearing pins and the like are not needed. On the other hand, howe ' ver, the resilient or plastic mounting of the clamping plate on the movable clamping jaw makes it possible to incorporate fairly coarse tolerances, since the forces which occur during clamping will in any case cause the clamping plate to abut in clamping manner on the belt or on the fixed clamping law as a function of the resulting deformation.

v, Z1 1 i 1.

Thus at least in its preferred forms the invention provides a clamping device which may be mass produced with reduced manufacturing and assembly costs whilst meeting the requirements of operational reliability of the clamping device.

According to a preferred embodiment of the invention, the clamping plate is mounted in the manner of a hook on the movable clamping jaw and a deformable support member of elastomer is inserted between the clamping plate and the clamping jaw. Because of its rate of deformation which remains constant under load,-the support member ensures a constant transmission of force in the event of clamping and, when the load is removed, it returns the clamping plate to its original position.

In so far as the invention also proposes the plastic deformation of support members, for example in the form of support ribs, the movable clamping jaw will have to be changed after being under load, but because of the simple construction of the clamping device and the less stringent tolerances required-in relation to the other parts of the clamping device this is easy to do.

Finally, the invention advantageously makes it possible in a preferred embodiment to incorporate the roughness of the relevant clamping plate surface needed for non-slip clamping of the belt in the manufacturing tool for the clamping plate, so that the clamping plate and roughness profile can be produced in one piece. This advantageously reduces the manufacturing tolerances and there is no need for any subsequent machining of the surface of the clamping plate or the provision of an additional part or a separate layer of material on the surface of the clamping plate.

A preferred embodiment of the invention which will now be described by way of example and with reference to the accompanying drawings, in which:Fig. 1 shows a diagrammatic side view of a clamping device in the open position; Fig. 2 shows the clamping device of Figure 1 in the clamped position; and Fig. 3 shows an enlarged perspective view of the movable clamping law.

A safety belt arrangement consists of a belt reeling means 10 from which the belt 11 unwinds, and a clamping device 12 which grips the belt 11 between a clamping jaw 13 fixed to the housing and a movable clamping jaw 14; an actuating lever 15 operated by sensors actuates the movable clamping law 14 to abut on the belt 11 or on the fixed clamping law 13 when the clamping device 12 is activated.

The movable clamping jaw 14 is pivotally mounted by means of a bolt 16 in a common housing 17 which accommodates both the belt reeling means 10 and also the clamping device 12, whilst a spring tongue 22 formed on the housing 17 ensures that the movable clamping jaw 14 is biased into its open position.

The movable clamping jaw 14 has, on its front side, a clamping plate 18 which is integrally formed thereon in a hook shape and which is provided, on its portion facing the belt 11, with a corresponding roughness profile 19, integrally formed with the clamping plate- 18, in the form of teeth, knurling, or a corrugated or honeycomb profile, so that a corresponding clamping action is obtained when it abuts on the belt 11. Between the clamping plate 18 and the body of the clamping jaw 14 is inserted a support member 20 which, in the embodiment shown by way of example consists of a block of elastomeric material. A lug 21 provided on the clamping law 14 ensures a secure connection and mounting between the support member 20 and the clamping jaw 14 which carries it. Such a lug may alternatively or additionally be provided on the clamping plate 18.

L; Although this is not shown in detail, deformable support ribs or other protruberances of material may be provided between the clamping plate 18 and the movable clamping jaw 14, giving the same supporting effect in the resting position and suitable deformation in the loaded state.

As can be seen from Figures 1 to 3 taken together, the clamping plate 18 is initially, in the unloaded state (Figure 1), at a corresponding spacing from the movable clamping law 14 which is determined by the dimensions of the support member 20 provided. If (Fig. 2) the movable clamping jaw 14 is pivoted upwardly by the actuating lever 15, the clamping plate 18 with the roughness profile 19 comes to abut on the belt 11 and presses the belt against the fixed clamping law 13 because of the conditions of spacing and leverage prevailing; a further pull on the belt 11 intensifies the contact force and thus, in the clamped position, the desired parallel abutment of the clamping plate 18 on the belt 11 or on the fixed clamping jaw 13 is obtained, as the clamping plate 18 changes its position relative to the movable clamping jaw 14 by deformation of the elastomer support member 20. Since in this case the elastomer support member 20 offers the desired clearance for the adjustment of the position of the clamping plate 18, in relation to the desired final state, and suitable deformation occurs as a function of the clamping forces prevailing, any dimensional tolerances are compensated for in the design and assembly of the clamping device.

When the tension on the belt slackens, if the support member 20 is of elastic construction, the clamping plate 18 is returned to its original position opposite the movable clamping jaw 14, whilst the movable clamping law 14 in turn is returned to the unloaded starting position by the spring tongue 22 mounted on the housing 17. By superimposing the recoil forces thus occurring at two points, it is advantageously possible to provide the recoil spring which is required in the prior art for the movable clamping jaw as a simple spring tongue which is integrally formed on the housing 17, thus saving further material, manufacturing and assembly costs in the production of the clamping device as a whole.

If plastic deformation of the clamping plate 18 relative to the movable clamping jaw 14 is provided, the movable clamping law 14 must be replaced after loading has occurred; however, this replacement does not present any problems, in the light of the advantages, since the u niformly produced, movable clamping jaws 14 with integrally formed clamping plate 18 can easily be fitted into the existing clamping device, since any dimensional tolerances occurring are compensated by the deformation clearance provided.

It is to be clearly understood that there are no particular features of the foregoing specification, or of any claims appended hereto, which are at present regarded as being essential to the performance of the present invention, and that any one or more of such features or combinations thereof may therefore be included in, added to, omitted from or deleted from any of such claims if and when amended during the prosecution of this application or in the filing or prosecution of any divisional application based thereon. Furthermore the manner in which any of such features of the specification or claims are described or defined may be amended, broadened or otherwise modified in any manner which falls within the knowledge of a person skilled in the relevant art, for example so as to encompass, either implicitly or explicitly, equivalents or generalisations thereof.

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Claims

Claims "'f - il 1. A clamping device for a safety belt system, having a

housing, a clamping jaw fixed relative to the housing, a movable clamping iaw arranged to be controlled by at least one sensor and located such that a safety belt may be guided between the clamping jaws, the movable clamping jaw having a clamping plate which is arranged such that in the clamped position it is disposed parallel to the fixed clamping jaw and the belt, wherein the clamping plate is integral with the movable clamping jaw and, under a clamping load, can change its position relative to the movable clamping jaw by deformation.
2. A clamping device as claimed in claim 1, wherein the clamping plate is connected in resiliently deformable manner to the movable clamping law.
3. A clamping device as claimed in claim 1, wherein the clamping plate is connected to the movable clamping law in plastically deformable manner.
4. A clamping device as claimed in claim 1, 2 or 3, wherein the clamping plate is formed in a hook shape on the movable clamping jaw and a deformable support member is arranged between the clamping plate and the movable clamping jaw.
5. A clamping device as claimed in claim 4, wherein the support member consists of a block of elastomer.
6. A clamping device as claimed in claim 4 or 5, wherein the movable clamping jaw and/or the clamping plate has a lug for mounting the support member.

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7. A clamping device as claimed in claim 4, wherein at least one deformable rib of material is provided as the support member.
S 8. A clamping device as claimed in any preceding claim, wherein the clamping plate and the movable clamping jaw are integrally formed as an injection moulded plastics component.
9. A clamping device as claimed in any of claims 1 to 7, wherein the clamping plate and the movable clamping jaw are integrally formed as an extruded aluminium profile.
10. A clamping device as claimed in any of claims 1 to 7, wherein the clamping plate and the movable clamping iaw are integrally formed as a die-cast aluminium component.
11. A clamping device as claimed in any preceding claim, wherein a roughness profile is integrally incorporated in the surface of the clamping plate arranged to face the safety belt.
12. A clamping device substantially as hereinbefore described with reference to the accompanying drawings.

P Published 1988 a' I The Patent Office. State House. 66 71 High Holborn. London WC1R 4TP. Further copies may be obtained from The Patent Office.

Sales Branch. St Mary Crw;. Orpingtor., Kent BR5 3RD Printed by Multiplex techniques ltd. St Mary Crky. Kent Con 1'87