GB2396585A

GB2396585A - A safety seat anchoring mechanism for a stroller

Info

Publication number: GB2396585A
Application number: GB0230041A
Authority: GB
Inventors: Jen-En Hou; Chuan-Tso Tai
Original assignee: Link Treasure Ltd; Link Treasure Ltd Taiwan
Current assignee: Link Treasure Ltd
Priority date: 2002-12-23
Filing date: 2002-12-23
Publication date: 2004-06-30
Anticipated expiration: 2022-12-23
Also published as: GB0230041D0; GB2396585B; GB2396585A9

Abstract

A seat belt retractor arrangement comprises a retractor reel (1), a locking mechanism (2) having a support (9) and a locking member (8), pivotally mounted to the support by a mounting element (22), moveable between a locked position, preventing movement of the reel, and an unlocked position allowing the reel to rotate freely; wherein the mounting element has an elongated cross section (preferably substantially rectangular with rounded edges) and is rotatably received in an aperture (15) which communicates with an open-ended channel having a width less than the diameter of the aperture. The mounting element is sized such that it can only pass along the channel when the longitudinal axis of its cross section is substantially aligned with the axis of the channel, the mounting element being designed such that the axis are misaligned during the movement of the locking member between the locked and unlocked positions.

Description

DESCRIPTION OF INVENTION

IMPROVEMENTS IN OR RELATING TO A SEAT-BELT

10 RETRACTOR ARRANGEMENT

THE PRESENT INVENTION relates to a seat-belt retractor arrangement, and more particularly relates to a seat-belt retractor arrangement for a motor 1 5 vehicle.

Motor vehicles are typically provided with a retractable seat-belt arrangement in which a length of seat-belt is wound on an inertia-type retractor reel. Such arrangements include a mechanism or electrical circuit arranged to 20 lock up the retractor reel in the event of an accident, thereby preventing the retractor reel from rotating in a "payout" direction, and hence preventing the seat-belt from being paid-out from the retractor reel so that the seat-belt serves a proper restraining function.

25 For many years, retractor reel arrangements of the general type discussed above have included a mechanical inertia-activated system configured to lock up a retractor reel in the event that a high deceleration, such as may occur during an accident, is experienced.

In recent years, it has become increasingly desirable to mount seat belt retractors within the back-rests of motor vehicle seats. However, because most vehicle seats are adjustable such that the angle of the back-rest relative to the 5 squab of the seat can be varied, conventional mechanical inertia actuator arrangements of this type have been found to be unreliable when located in a back-rest, because of the wide range of angles in which the arrangement must operate. It has therefore been proposed to provide an electrical actuator configured to lock-up the retractor reel in the event of a crash situation, because 10 such electrical arrangements and their associated sensors operate effectively regardless of their orientation.

DE19620236C2 discloses a seat-belt retractor arrangement comprising an electrical actuator mechanism. The arrangement comprises a retractor reel 15 mounted to a ratchet arrangement. A locking arm is pivotally mounted to an actuator in a fixed manner, the locking arm being moveable from an unlocked position to a locked position in which it engages a toothed wheel carried by the retractor reel, which is associated with an integral locking mechanism. If the toothed wheel rotates relative to the reel, the locking mechanism is actuated, 20 thereby preventing the retractor reel from rotating in a pay-out direction. The locking arm carries a first permanent magnet which is repelled by a second permanent magnet so as to urge the locking arm towards the locked position.

An electromagnet is provided which can be energised upon receipt of an appropriate signal, in order to overcome the repulsive force between the two 25 permanent magnets and attract the first permanent magnet carried by the locking arm, so as to pull the locking arm out of its locked position towards its unlocked position.

In the arrangement of DE19620236C2, the locking arm is permanently fixed to the supporting structure via a pivotal coupling. Thus, it has been proposed previously in arrangements of this type to provide the locking arm with a pair of aligned mounting projections extending outwardly from the 5 locking arm, each mounting projection taking the form of a generally cylindrical spigot which is received within an elongate U- shaped slot formed in the support structure of the actuator mechanism. In this way, the locking arm can be easily mounted to the support during manufacture of the retractor arrangement, simply by lowering the two spigots into their respective U-shaped 10 slots. When each spigot is located at the closed bottom end of its respective U shaped slot, the spigot is allowed freely to rotate in the slot.

However, whilst the above-mentioned arrangement incorporating U shaped slots is simple to produce during manufacture, it has been found that in 15 operation the spigots can jump upwardly within the U-shaped channels, away from the closed end of the channels, which can result in noisy operation of the mechanism, which is disadvantageous.

The present invention therefore seeks to provide an improved seat-belt 20 retractor arrangement.

Accordingly, the present invention provides a seat belt retractor arrangement, comprising: a retractor reel with one end of a seat-belt wound around it; 25 a locking mechanism having a support and a moveable locking member pivotally mounted to the support for pivotal movement between an unlocked position in which the locking member is substantially clear of the retractor reel such that the retractor reel is allowed to rotate substantially freely in a pay-out direction thereby allowing the seat-belt to pay out from the retractor reel, and a

locked position in which the locking member engages part of the retractor reel to prevent rotation of the retractor reel in said pay out direction; and an actuator arrangement operable to move said locking member between said locked and unlocked positions; 5 wherein said locking member is pivotally mounted to said support via a mounting element carried by the locking member, the mounting element having an elongate cross-section and being rotatably received within a recess or aperture formed on the support, the recess or aperture communicating with an open-ended channel having a width less than the diameter of the aperture or 10 recess, the mounting element being sized so as to pass along the channel when the longitudinal axis of its cross-section is substantially aligned with the axis of the channel but so as not to pass along the channel when the longitudinal axis of its cross-section is misaligned with the channel, the mounting element being configured such that said longitudinal axis is substantially misaligned with the 15 channel during movement of the locking member between said locked and unlocked positions.

Preferably, the length of the mounting element cross-section is sized to be a close rotational fit within said aperture or recess.

Advantageously, said mounting element is substantially rectangular in cross-section. Conveniently, the corners of said rectangular crosssection are rounded.

Preferably, said aperture or recess is substantially circular.

Advantageously, said locking member is provided with a pair of said mounting elements, each received within a respective said aperture or recess formed on the support.

5 Conveniently, at least part of said locking member is ferrous and said actuator arrangement is electromagnetic.

So that the invention may be readily more understood, and so that further features thereof may be appreciated, an embodiment of the invention will now 10 be described, by way of example, with reference to the accompanying drawings, in which: FIGURE 1 is a schematic drawing illustrating a known type of seat-belt retractor arrangement having a retractor reel and a locking mechanism in an 15 initialunlocked position; FIGURE 2 is a perspective view of the locking mechanism of the arrangement illustrated in Figure 1; FIGURE 3 is an enlarged view of part of the locking mechanism of Figures 1 and 2; 20 FIGURE 4 is a view corresponding generally to that of Figure 1, but illustrating a locking member of the locking mechanism in a locked position in which it prevents rotation of the retractor reel in a pay-out direction; FIGURE 5 is a view similar to that of Figure 1, but illustrating a seat belt retractor arrangement in accordance with the present invention; 25 FIGURE 6 is a perspective view of the locking mechanism of the seat belt retractor arrangement illustrated in Figure 5; FIGURE 7 is an enlarged view of part of the locking mechanism of Figures 5 and 6; and

FIGURE 8 is a view corresponding generally to that of Figure 5, but illustrating a locking member of the locking mechanism in a locked position in which it prevents rotation of the retractor reel in a pay-out direction.

5 It is appropriate first to consider a known type of seat-belt retractor arrangement as illustrated in Figures l to 4, before considering the features of the seat-belt retractor arrangement of the present invention, as illustrated in Figures 5 to 8.

10 The known type of seat-belt retractor arrangement illustrated in Figure 1 essentially comprises a retractor reel l and a locking mechanism 2. The retractor reel 1 is mounted for rotation, preferably within the back-rest of the motor vehicle seat, and has one end of a conventional seat-belt 3 wound around it. The retractor reel 1 is mechanically biased so as to rotate in a "winding-in" 15 direction (as indicated by arrow 4) to wind the seat-belt 3 onto the retractor reel 1. However, the retractor reel 1 is able to rotate in a 'key-out" direction (as indicated by arrow 5) in the event that sufficient pull is exerted on the seat-belt 3 to overcome the mechanical bias acting to wind-in the seat-belt 3.

20 A toothed wheel 6 is mounted to the retractor reel 1 for co-rotation with the retractor reel 1. The wheel 6 is provided with a plurality of teeth 7 around its periphery.

The locking mechanism 2 is mounted with respect to the retractor reel l 25 so as to be generally spaced from the toothed wheel 6. However, as will become clear hereinafter, the locking mechanism 2 comprises a locking member 8 which is operable to engage the toothed wheel 6.

The locking mechanism 2 comprises a support frame 9. The support frame 9 has a substantially horizontal base plate 10 which is bent upwardly at one end so as to define a side wall 11 extending upwardly and perpendicularly from the base plate 10. A support finger 12 extends outwardly from the base 5 plate 10 in the region where it is bent upwardly to form the side wall 11, such that the support finger 12 projects past the side wall 11.

The support frame 9 also comprises a top plate 13 which extends from the uppermost end of the side wall 11, and lies generally parallel to the base 10 plate 10. Upstanding from opposite edges of the top plate 13 are a pair of support lugs 14, each of which defines a respective mounting recess 15. As illustrated most clearly in Figure 3, each mounting recess 15 takes the form of a generally elongate U-shaped recess which is open at its uppermost end and which defines a smoothly-rounded lower end 16.

An electromagnet 17 is mounted on the support frame 9 between the base plate 10 and the top plate 13. The electromagnet 17 comprises, as is conventional, a coil of electrically-conductive wire 18 which is helically wound around a soft-iron core 19, the top of which is just visible in Figure 1. The wire 20 18 is electrically connected to a power supply (not shown) so that the electromagnet 17 can be selectively energised by passing an electric current through the wire 18.

The locking member 8 is generally planar but is provided, projecting 25 from its uppermost surface, with a locking tooth 20 which, as will become clear, is configured to engage the teeth 7 of the toothed wheel 6 upon actuation of the locking mechanism 2. Secured to the undersurface of the main planar part of the locking member 8, there is provided a generally planar plate of ferrous material 21.

The locking member 8 is sized so as to be received between the two support lugs 14 upstanding from the top plate 13 of the support frame 9, and is provided with a pair of outwardly-directed mounting elements 22, each of 5 which is received within a respective mounting recess 15, and is sized to be a close rotational fit within the lowermost end 16 of the recesses 15. It will therefore be appreciated that the mounting elements 22 are each free to rotate within respective mounting recesses 15. In this way, the locking member 8 is pivotally mounted to the support frame 9.

A projection 23 extends outwardly from the locking member 8 at a position located substantially centrally between the two mounting elements 22, so as to project past the axis of the mounting elements 22. A helical spring 24 is mounted between the mounting finger 12 carried by the support frame 9 and 15 the projection 23 of the locking member 8 and so serves to pull the projection 23 of the locking member 8 towards the mounting finger 12, thereby pivoting the mounting member 8 with respect to the support frame 9 and lifting the parts of the locking member 8 extending over the electromagnet 19. The locking member 8 is thus mechanically biased by the spring 24 away from the position 20 illustrated in Figures 1 and 2, and towards the raised position illustrated in Figure 4. However, it should be understood that when the electromagnet 17 is energised, the electromagnet attracts the ferrous part 21 of the locking arm 8 so as to overcome the mechanical bias provided by the spring 24. Thus, in Figures l and 2, the electromagnet 17 is in an energised state.

When the electromagnet 17 is energised as illustrated in Figures 1 and 2, the locking arm 8 adopts an unlocked position in which it is substantially clear of the toothed wheel 6 and hence allows the retractor reel 1 to rotate substantially freely in its pay-out direction 5.

However, upon receipt of an appropriate signal from a crash sensor or inertia sensor, the power supply to the electromagnet 17 is cut such that electric current is no longer provided to the coil of wire 18. The electromagnet 17 is 5 thus de-energised such that it no longer serves to attract the ferrous part 21 of the locking member 8. In this condition, the spring 24 becomes free to contract, thereby pulling the projection 23 of the locking member 8 towards the finger 22 and hence lifting the region of the locking member 8 which extends over the electromagnet 17. This condition is illustrated in Figure 6, and it will 10 be seen that in this position, the locking tooth 20 of the locking member 8 serves to engage a tooth 7 of the toothed wheel 6 thereby actuating the integral locking mechanism if the reel moves relative to the toothed wheel, preventing further rotation of the inertia reel 1 in the pay-out direction 5. However, the retractor reel l may rotate in its winding-in direction 4, in which case the 15 integral locking mechanism is released and the teeth 7 will simply ride over the locking tooth 20 and urge the locking member 8 downwardly against the bias of the spring 24 so that the teeth 7 can move past the locking tooth 20. Therefore, de-energisation of the electromagnet 17 serves to actuate the locking mechanism 2 such that the locking member 8 engages the toothed wheel 6.

Having particular regard to Figure 3, it will be seen that the elongate U-

shaped configuration of the mounting recesses 15, being open at their upper end, allows the mounting elements 22 of the locking member 8 to be very easily and quickly received within the mounting recesses 15, thereby allowing quick 25 and simple mounting of the locking arm 8 on the support frame 9. This clearly has significant advantages during the manufacture of the locking mechanism 2.

However, because the locking elements 22 are unconstrained against vertical movement away from the lowermost end 16 of the mounting recesses 15 (as indicated by arrow 25 in Figure 3), the mounting elements 22 can jump

upwardly within the recesses 15 so as to move away from the lowermost ends 16 of the recesses 15 during operation of the locking mechanism 2 and in particular as the locking member 8 approaches it unlocked position illustrated in Figure 1 upon energisation of the electromagnet 17. If the mounting 5 elements 22 move away from the lowermost end 16 of the recesses 15 in this way, then they are subsequently pulled sharply back down again under the biasing action of the spring 24. This results in the mounting elements 22 impacting against the lowermost ends 16 of the recesses 15 which generates unwanted and undesirable noise as the two components bang together. This is 10 disadvantageous. Figures 5 to 8 correspond generally to Figures 1 to 4, but illustrate a modified arrangement in accordance with the present invention. In many respects, the seat-belt retractor arrangement illustrated in Figures 5 through to 8 15 is identical to that illustrated in Figures 1 through to 4 and so it is not necessary to described again such features of the present invention (which are identified by the same reference numerals).

However, on the seat-belt retractor arrangement of the present invention, 20 the mounting elements 22 of the known arrangement are replaced with mounting elements 32 which, as best illustrated in Figure 7, have an elongate cross-section. The preferred configuration of cross-section for the mounting elements 32 is generally rectangular, but with rounded or chamfered corners 33.

25 The modified mounting elements 32 are again received within mounting recesses formed in each support lug 14, but in the present invention, the mounting recesses take the form of a generally circular terminal recess part 34 which communicates with an elongate and generally linear channel 35 extending generally upwardly away from the terminal recess part 34. This

channel 35 is open at its other end. The width of the channel 35 is significantly less than the diameter of the recess 34. As illustrated in Figures 5 through to 8, the mounting elements 32 are sized such that the length of the mounting element cross-section is a close rotational fit within the recess 34. The 5 preferred chamfered or rounded corners 33 assist with ensuring this close rotational fit. However, the width of the mounting element cross-section is slightly less than the width ofthe channel 35.

Because the lengths of the mounting elements' cross-section are sized so 10 as to be a close rotational fit within the recess 34, and because the width of the channel 35 is significantly less than the recess 34, then providing the longitudinal axis of each mounting element cross-section is not aligned with the axis of the channel 35, the mounting elements 32 will be constrained to remain within the recesses 34. As illustrated in Figures 5 and 8, the mounting elements 15 32 are both oriented relative to the locking member 8, such that they remain mix-aligned with the axis of the channel 35 when the locking member adapts its unlocked position illustrated in Figure 5, its locked position illustrated in Figure 8, and any intermediate position therebetween. Therefore, at all times during the normal operation of the locking mechanism 2, the mounting elements 32 are 20 tightly constrained against upwards movement within the recesses, thereby eliminating the noise problems associated with the known arrangement.

Because the width of the mounting elements 32 is slightly less than the width of the channel 35, then if the locking member 8 is manipulated such that 25 both of the mounting elements 32 became aligned with their respective channels 35, the elements 32 can be lifted upwardly and removed from the recesses 34 so as to pass along the channels as illustrated in phantom in Figure 7. This allows disengagement of the locking member 8 from the support frame 9, should such disengagement be required.

Of course, this relationship between the configuration of the mounting elements 32 and the recesses 34 and slots 35, still allows very simple mounting of the locking arm 8 on the support frame, by aligning the longitudinal axes of 5 the cross-sections of the mounting elements 32 with the axes of the channels 35 and passing the elements along the channels until the elements are received within the recesses 34. Then, simple manipulation of the locking member 8 turns the mounting elements 32 out of alignment with the channels such that they are substantially misaligned with the channels and become constrained lO within the recesses 34 for movement of the locking member 8 between its locked and unlocked position, without any vertical movement of the mounting elements 32.

In the present specification "comprises" means "includes or consists of"

15 and "comprising" means "including or consisting of".

The features disclosed in the foregoing description, or the following

claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process 20 for attaining the disclosed result, as appropriate, may, separately, or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

CLAIMS:

1. A seat belt retractor arrangement, comprising: a retractor reel with one end of a seat-belt wound around it; a locking mechanism having a support and a moveable locking member 10 pivotally mounted to the support for pivotal movement between an unlocked position in which the locking member is substantially clear of the retractor reel such that the retractor reel is allowed to rotate substantially freely in a pay-out direction thereby allowing the seat-belt to pay out from the retractor reel, and a locked position in which the locking member engages part of the retractor reel 15 to prevent rotation of the retractor reel in said pay out direction; and an actuator arrangement operable to move said locking member between said locked and unlocked positions; wherein said locking member is pivotally mounted to said support via a mounting element carried by the locking member, the mounting element having 20 an elongate cross-section and being rotatably received within a recess or aperture formed on the support, the recess or aperture communicating with an open-ended channel having a width less than the diameter of the aperture or recess, the mounting element being sized so as to pass along the channel when the longitudinal axis of its cross-section is substantially aligned with the axis of 25 the channel but so as not to pass along the channel when the longitudinal axis of its cross-section is misaligned with the channel, the mounting element being configured such that said longitudinal axis is substantially misaligned with the channel during movement of the locking member between said locked and unlocked positions.

2. A seat belt retractor arrangement according to claim 1, wherein the length of the mounting element cross-section is sized to be a close rotational fit within said aperture or recess.

3. A seat belt retractor arrangement according to claim 1 or claim 2, wherein said mounting element is substantially rectangular in crosssection.

4. A seat belt retractor arrangement according to claim 3, wherein the lO corners or said rectangular cross-section are rounded.

5. A seat belt retractor arrangement according to any preceding claim, wherein said aperture or recess is substantially circular.

15

6. A seat belt retractor arrangement according to any preceding claim, wherein said locking member is provided with a pair of said mounting elements, each received within a respective said aperture or recess formed on the support.

20

7. A seat belt retractor arrangement according to any preceding claim, wherein at least part of said locking member is ferrous and said actuator arrangement is electromagnetic.

8. A seat belt retractor arrangement substantially as hereinbefore described 25 with reference to and as shown in Figures 5 to 8 of the accompanying drawings.

9. Any novel feature or combination of features disclosed herein.