WO2007026129A1

WO2007026129A1 - Belt tension indicator

Info

Publication number: WO2007026129A1
Application number: PCT/GB2006/003172
Authority: WO
Inventors: David Shaun Carine; David Downie
Original assignee: Britax Excelsior Limited
Priority date: 2005-08-27
Filing date: 2006-08-24
Publication date: 2007-03-08
Also published as: CN101247977A; EP1937522A1; CA2616509A1; GB0517532D0

Abstract

The present invention relates to a tension indicator for indicating tension in a belt. The indicator comprises first and second belt path defining members (521, 522) arranged to be spaced from one another along a belt path defined therebetween, a third belt path defining member (550), provided between the first and second belt path defining members in said belt path, the third belt path defining member being resiliently biased into the belt path defined between the first and second belt path defining members . The third belt path defining member is provided with indicating means (547) for indicating its extent of movement.

Description

BELT TENSION INDICATOR

The present invention relates to a tension indicator for a strap or belt in a passenger restraint fitted to a transport vehicle.

Inadequate tension in a restraint belt can severely degrade the performance of the restraint as a whole. Please note that the term "belt" is used hereinbelow in respect of the present invention with the intention of it being synonymous with "strap" or any other term such as "webbing" meaning a wide, thin, -elongate textile material member.

In our patent application No. 0512273.4, we have described a tension indicator suitable for use on a strap of a harness of a child restraint, whose primarily intention is to indicate of absence of slack and the presence of a small degree of tension in the strap.

The object of the present invention is to provide a tension capable to indicating that a quantum of tension is present in a restraint belt.

According to an aspect of the present invention there is provided a tension indicator for indicating tension in a belt, the indicator comprising:- first and second belt path defining members arranged to be spaced from one another along a belt path defined therebetween, a third belt path defining member, provided between the first and second belt path defining members in said belt path, the third belt path defining member being resiliently biased into the belt path defined between the first and second belt path defining members; wherein said third belt path defining member is provided with indicating means for indicating its extent of movement. In this manner, a reliable device for establishing Q

the tension in a belt is provided.

Preferably, one or more of the belt path defining members comprises an elongate member extending transversely to said belt path and having an opening for allowing a belt to be threaded therethrough. This allows the tension indicator to be readily fitted to existing belts, provided within vehicles .

Conveniently, the tension indicator further comprises a housing within which said third belt path defining member is movably housed.

Preferably, said first and second belt path defining members are integrally formed as part of said housing. This provides for an effective and readily assembled structure.

The third belt path defining member can be housed for linear movement, and biased to project outwardly from a main body of said housing.

Preferably, said first and second belt path defining members are provided on limbs extending from said main housing body, a belt path thereby being defined between said first and second belt path defining members and said main housing body.

Conveniently, said limbs are inclined relative to the direction of travel of said third belt path defining member. The angle of inclination of the limbs may be substantially 40°.

Preferably, said indicating means comprises a connecting arm coupling ^* said third belt path defining member to an indicating element. Conveniently, said indicating element is pivotally mounted, and moves past an aperture in said housing on movement of said third belt path defining member.

Preferably, said indicating element has a surface, viewable through said aperture, marked to correspond with different deflections of said third belt path member. Hence, a extent of the tension of the belt can be readily attained.

Conveniently, said tension indicator comprises a pair of housing casings, said first and second belt path defining members being formed integrally with housing casings, said first and second belt path defining members extending on their respective housing casings such that when the casings are assembled together, the first and second belt path defining members do not quite meet, to thereby define an opening in each of the first and second belt path defining members. As such, the indicator can be easily and effectively assembled, with a minimum of parts.

Preferably, the housing casing has an arcuate profile for accommodating a pivotal movement of said indicating element.

Conveniently, the third belt path defining member and indicating element are coupled by an "L" shaped connection arm. The connection arm can be pivotally connected to both the third belt path defining member and the indicating element .

Preferably, the third belt path defining member is recessed to accept the pivotal attachment of the connection arm. This provides for a compact structure.

Conveniently, a pair of indicating elements are provided, arranged within said housing either side of said third belt path defining member.

According to a further aspect of the invention there is provided a tension indicator for a belt in a passenger vehicle restraint system, the indicator comprising: a body; a pair of generally parallel, belt path defining members arranged on the body for passage of the belt to one side of them; a third belt path member arranged for deflecting the belt path towards the other side of the said pair of members, the third member being mounted to be resilient with respect to the pair of members; and means for indicating deflection of the third member with respect to the pair of members in the presence of tension in the belt.

The belt path defining members co-operate to hold the tension indicator on the belt. Whilst it is envisaged that the belt could pass between th.e said third member and the body, whereby the third member holds the indicator on the belt, in the preferred embodiments, the said pair of members have the belt between themselves and the body for this purpose.

Conveniently, the said pair of members are each split at mid-length, whereby the tension indicator can be fitted to the belt, without recourse to threading the belt from one end around the belt path defining members, which is impractical where the belt is an adult seat belt installed in a car with a stitched on buckle.

Where the third member retains the body on the belt, it will normally be arranged for resilient urging of itself away from the body; whereas in the preferred embodiment, the third member is arranged to be urged towards the body by tension in the belt. For this, a compression spring is arranged within the body for urging the third member outwards of the pair of members. In one embodiment, the third member may provide no external indication of the state of tension in the belt, but the body is provided with a displacement transducer for giving an electrical indication of the tension. This is expected to be combined with a spigot extensible from the other side of the body in the presence of tension.-

In another embodiment, the indicator includes a least one flag movable in the body; a window in the body for viewing the flag; a connection between the flag and the third member for moving the flag with respect to the window and showing one indication in the absence of tension in the belt and another indication in the presence of tension.

Preferably the flag is pivotally arranged in the body for pivotal movement .

Again in the preferred embodiment, two flags, two windows and two connections are provided.

To help understanding of the invention, a number of specific embodiments thereof will now be described by way of example and with reference to the accompanying drawings, in which:

Figure 1 is a perspective view of a first tension indicator of the present invention;

Figure 2 is a similar perspective view of a second tension indicator of the invention;

Figure 3 is an underside perspective view of a third tension indicator of the invention;

Figure 4 is a top perspective view of the third tension indicator;

Figure 5 is an exploded view of the components of the third tension indicator; Figure 6 is a central, transverse cross-sectional view of the third tension indicator in its condition in which there is negligible tension in the belt to which the indicator is fitted; and

Figure 7 is a view similar to Figure 6 of the indicator when there is appreciable tension in the belt.

Referring to first to Figure 1, the tension indicator shown has a body 1 with a pair of belt abutment ridges 2,3 along lower edges of the body, with a belt B contacting the ridges on its top surface. A U-shaped member 4 is arranged between the ridges 2,3 for abutting the belt B on its opposite, lower surface.

As viewed in Figure 1, a top surface of a transverse limb of the U in contact with the belt, is above the level of the bottom surface of the ridges. With this arrangement, the belt run is deflected upwards over the transverse limb.

Tension in the belt tends to pull the third belt path member 4 down. It is able to move down against the action of springs 5 mounted inside the body. A displacement transducer

6 -is associated with the member 4 at one of the springs 5 for giving an indication of the position of the member 4 and hence the tension in the belt. The higher the tension, the greater the displacement and the indication.

Turning to Figure 2, tension indicator shown has a body 11 with two belt abutment members 12,13. These each take the form of a pair of inwardly directed fingers, of which one pair 121,122 is shown, with a gap 123 therebetween, through which the belt B can be threaded when pinched in half lengthways. Slidingly carried by the body between the members 12,13 is a third abutment member 14, having an upwards extension 16, surrounded by a spring 15 abutting within the body. The members 12,13,14 impose a path on the belt which is deflected from straight. When the belt is tensioned, it straightens, urging the underside of the member 14 in line with the top of the members 12,13. This projects the extension 16 above the top surface of the body, indicating that the belt is tensioned.

Turning on to Figures 3 to 7, the tension indicator there shown is closer to that of Figure 2 than Figure 1, but more sophisticated. It has two identical body parts 511,512, each having a pair of belt abutment fingers 521,522. The abutment fingers are provided on limbs inclined at an angle ø ofaround 40° to the direction of travel of belt abutment member 550.

The body parts abut centrally and are held together by pegs and sockets 513,514 (see Figure 5). Centrally the body has a cavity 515, with edge guides 516 and a central spring locating formation 517.

Opposite the fingers 521,522, the body as two windows 518. A belt abutment member 550 also of two halves 541,542 held together by pegs and sockets 543,544 is accommodated in the cavity and urged outwards by a spring 55. At recesses 545 links 546 are pivoted to the third abutment member. The other ends of the links are pivoted to flags 547, themselves pivoted on the pegs 513.

The arrangement is such that when the belt B is slack, the spring urges the third member to its position in which SLACK indications 56 on the flags show at the windows. When tension in the belt urges the third member in, the flags are turned on the pegs 513, to show TENSIONED indications 57 at the windows. It will be appreciated that in accordance with the rate of the spring and the stroke of the third member required for the SLACK indications 56 to be completely replaced by TENSIONED indications 57, an accurate quantum of belt tension can be indicated. In other words the user can be confident that if the TENSIONED indications are fully exposed, an adequate tension is present in the belt for a purpose, such as holding a child safety seat securely with an adult seat belt.

Claims

Claims :

1. A tension indicator for indicating tension in a belt, the indicator comprising: - first and second belt path defining members arranged to be spaced from one another along a belt path defined therebetween, a third belt path defining member, provided between the first and second belt path defining members in said belt path, the third belt path defining member being resiliently biased into the belt path defined between the first and second belt path defining members; wherein said third belt path defining member is provided with indicating means 'for indicating its extent of movement.

2. A tension indicator according to claim 1, wherein one or more of the belt path defining members comprises an elongate member extending transversely to said belt path and having an opening for allowing a belt to be threaded therethrough .

3. A tension indicator according to claim 1 or 2, further comprising a housing within which said^; third belt path defining member is movably housed.

4. A tension indicator according to any one of claims 1 to 3, wherein said first and second belt path defining members are integrally formed as part of said housing.

5. A tension indicator according to any preceding claim, wherein said third belt path defining member is housed for linear movement, and biased to project outwardly from a main body of said housing. β. A tension indicator according to claim 5, wherein said first and second belt path defining members are provided on limbs extending from said main housing body, a belt path thereby being defined between said first and second belt path defining members and said main housing body.

7. A tension indicator according to claim 6, wherein said limbs are inclined relative to the direction of travel of said third belt path defining member.

8. A tension indicator according to claim 7, wherein the angle of inclination of the limbs is substantially 40°.

9. A tension indicator according to any preceding claim, wherein • said indicating means comprises a connecting arm coupling said , third belt path defining member to an indicating element.

10. A tension indicator according to claim 9, wherein said indicating element is pivotally mounted, and moves past an aperture in said housing on movement of said third belt path defining member.

11. A tension indicator according to claim 10, wherein said indicating element has a surface, viewable through said aperture, marked to correspond with different deflections of said third belt path member.

12. A tension indicator according to any preceding claim, said indicator comprising a pair of housing casings, said first and second belt path defining members being formed integrally with housing casings, said first and second belt path defining members extending on their respective housing casings such that when the casings are assembled together, the first and second belt path defining members do not quite meet, to thereby define an opening in each of the first and second belt path defining members.

13. A tension indicator according to any preceding claim, wherein the housing casing has an arcuate profile for accommodating a pivotal movement of said indicating element.

14. A tension indicator according to claim 13, wherein the third belt path defining member and indicating element are coupled by an "L" shaped connection arm.

15. A tension indicator according to claim 13 or 14, wherein the connection arm is pivotally connected to both the third belt path defining member and the indicating element.

16. A tension indicator according to any one of claims 13 to 15, wherein the third belt path defining member is recessed to accept the pivotal attachment of the connection arm.

17. A tension indicator according to claim 13, wherein a pair of indicating elements are provided, arranged within said housing either side of said third belt path defining member.

18. A tension indicator substantially as hereinbefore described with reference to the accompanying drawings.