AU599857B2 - Passive safety belt system - Google Patents

Description

I-*~C.C7ic C.PTED AND hvi, L- 1 4 r- I~,~---I*rrrrll l IL ~~ILl~kC -i i 599 8 5 7 COMMONWEALTH OF AUSTRALIA PATENTS ACT 1952 COMPLETE SPECIFICATION NAME ADDRESS OF APPLICANT: a a 0p o o 0 TRW Repa GmbH Industriestrasse 20 Alfdorf 7077 Federal Republic of Germany NAME(S) OF INVENTOR(S): This document contains the amendments made under Section 49 and is correct for printg. _i Wolf-Dieter HONL Hermann WELLER ADDRESS FOR SERVICE: DAVIES COLLISON Patent Attorneys 1 Little Collins Street, Melbourne, 3000.

COMPLETE SPECIFICATION FOR THE INVENTION ENTITLED: Passive safety belt system The following statement is a full description of this invention, including the best method of performing it known to me/us:i 4 The basic application.......... relerrea to in paragiap"n a v. eX the first application.......... made in a Convention country in respect of the invention the subject of the application.

Declared at A dorf th day of February, 1989 Decla ed at A lf"d or f MA 1,;xitw 114.

Insert place and date of signature.

Signature of declarant(s) (no aftestation required) Note' Initial all alterations.

t1 1 Wolf-Dieter Klink WPaWmpa ra Ml Industriss1ie.ql DAVIS OLLISON,MELBOURNEand CANBERRA.

DAVIES COLL1SON, MELBOURNE and CAN BERRA.

T I '-sq I C0 0 0 o 0 5, 00 0 0 0 0 0 0 0 0000 0 o 0 00 0 QO 00 0 0 0 o o[ o a l 3 0 0 The present invention relates to a passive safety elt system in which a shoulder belt extends between a belt retractor fixed with respect to the vehicle bodywork and a movable end fitting which is guided by means of a slide member and by a guide rail fixed with respect to the vehicle bodywork between a holding means corresponding to the unfastened position and a detent means corresponding to the fastened position of the safety belt.

A passive safety belt system means a system which ensures automatic fastening of the safety belt. In dependence on vehicle operating parameters, for example ignition key or door position, the end fitting is moved by means of a motor drive between the unfastened position and the fastened position. The movement of the end fitting is guided by a guide rail which extends for example from the lower end of the A post along the upper door frame tl -2member up to the upper end of the B post. Further more, such safety belt systems are generally equipped with a belt retractor with which an automatic locking mechanism is associated for blocking the belt withdrawal in the event of danger. By the action of the takeup spring of the belt retractor the webbing is always held under a certain tension so that no appreciable belt slack can occur. During the fastening operation as well the webbing is under this tension so that it extends approximately rectilinearly between the belt retractor and the end fitting until it comes to bear on the body of the vehicle occupant and 's deflected thereby.

Now, as soon as the webbing during the fastening 0e00 15 operation comes to bear on the body of the occupant it is pulled in the longitudinal direction over the contact surface because the one end of the webbing is secured to the end fitting and by the deflection of the webbing at the contact surface with the vehic-e occupant on further o 20 movement of the end fitting to the detent means more webbing must be withdrawn from the belt retractor. This sliding contact with the webbing may be found to be troublesome.

Ii The present invention provides a passive safety belt system wherein no immediate impairment of the vehicle occupants occurs during the fastening operation.

According to the present invention there is provided a

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passive'safety belt system comprising a belt retractor and a guide rail mounted in a vehicle, a shoulder belt section extending between said retractor and an end fitting movable along said guide rail between a first end position and a second end position, said belt retractor having a reel whereon said belt is wound, said reel being permanently under the action of a takeup spring which wOO5O1jnxpe.OO1.ky31314.spe,1 N0 3 normally keeps the webbing under a certain tension, a ratchet wheel attached to said reel and a detent member cooperating with said ratchet wheel to selectively block rotation of said reel in a belt winding direction, a solenoid being provided for controlling engagement of said detent member with said ratchet wheel and said solenoid being energized to engage said detent member with said ratchet wheel in response to said end fitting leaving said first end position and deenergized in response to said end fitting approaching said second end position, said solenoid, when energized, resiliently holding said detent member in engagement with said ratchet wheel to permit rotation of said reel in an unwinding direction.

o This construction ensures that in the initial phase of a the movement of the end fitting from the unfastened o o position to the fastened position firstly webbing is So a withdrawn from the belt retractor and thereafter a belt 0 0 0 slack is formed which is dimensioned such that up to the movement of the end fitting into the vicinity of the detent means there is still no contact between the webbing and the vehicle occupant. Only after the end fitting has reached the detent means or at least almost reached said means is the takeup function of the belt retractor established again by the locking means being inactivated so that the webbing can then come to lie Igently round the vehicle occupant. Pulling of the webbing,in its longitudinal direction over the contact surface with the vehicle occupant is therefore avoided.

The detent means is preferably constructed in the manner of an overrunning clutch which locks only in the belt, takeup direction and in the belt withdrawal permits rotation of the belt retractor so that during the movement of the end fitting over the initial portion of the guide rail the webbing can be withdrawn unrestricted 3a from the belt retractor to form the desired belt slack.

A particularly expedient detent means consists of a ratchet wheel connected non-rotatably to the belt reel of the belt retractor and a pivotally mounted locking pawl co-operating with said wheel. The locking pawl is preferably held by a spring resiliently in its rest position out of engagement with the ratchet teeth and pivoted by an electromagnet into its engagement position at the ratchet teeth. The electromagnet is controlled by two switches which are arranged on the guide rail direction in front of the holding means and the detent y 00 @ea 00000 0 a a 00 00 0Q 0 a 0 oc~u 0 0 00 00 00 0 0 0( a

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Pt fi 900501. gjnspe.001,ky31314. spe, 3 Ut P r 4 1 means respectively and are actuable by the slide member.

Further features and advantages of the invention will be apparent from the following description of several examples of embodiment and from the drawings to which reference is made and in which: Fig. 1 is a schematic overall view of a passive twopoint safety belt system; Fig. 2 is a schematic representation of a first embodiment 4444 4411 of a belt retractor for the system according to 4. Fig. 1 with the housing plate broken away on the side; and Fig. 3 is a second embodiment of a corresponding belt retractor.

o444 r In the passive two-point safety belt system shown in Fig. 1 a safety belt retractor 10 is mounted adjacent 20 a vehicle seat 12 in the vicinity of the bottom of the vehicle bodywork. The webbing 14 extends from the belt retractor 10 up to and end fitting 16 which is connected to a slide member (not shown) which is guided in a guide- 2 rail 18 between a holding means 20 and a detent means 22. The holding means 20 is disposed at the lower end of the front A post of the vehicle bodywork the detent means 22 is disposed in the region of the upper end of the centre B post of the vehicle bodywork. The webbing 14 is shown in Fig. 1 in continuous lines in the unfasten- 8O ed position and in dashed lines in the fastened position.

The guide rail 18 comprises an initial portion which is adjacent the holding means 20 and is designated in Fig.

1 by A and extends between the holding means 20 and about the middle of the guide rail 18. In the direction of the detent means 22 a rectilinear intermediate portion Z follows said initial portion A which has a relatively slight curvature. Between the intermediate L r U I portion Z and the detent means 22 there is a relatively highly curved end portion E of the guide rail 18.

Indicated schematically in Fig. 1 are an electric switch 24 arranged on the guide rail adjacent the holding means and an electric switch 26 which is arranged on the guide rail 18 adjacent the detent means 22. The switches 24, 26 are actuated by the slide member when the latter moves in the guide rail 18 past the switches.

During the movement of the end fitting 16 out of the unfastened position over the initial portion A of the guide rail 18 the distance between the belt retractor and end fitting increases from the value designated by 0 °al to the value designated by a2. Webbing is therefore 0, oowithdrawn from the belt retractor 10. Said belt retractor o 15 o 5 is equipped with a locking means which will be described in detail hereinafter with the aid of Figs. 2 and 3 and Sthe function of which resides in blocking the takeup 00 o o function of the belt retractor 10 in controlled manner.

o 04 o 20 Said locking means is moved into its activated state S 04 by the switch 24 when the slide member is moved past said switch 24. Only on actuation of the switch 26 by the slide member is the locking means deactivated again, the takeup function of the belt retractor then being reestablished. When the end fitting 16 has reached the of the initial portion A of the guide rail 18 the i distance between the belt retractor and end fitting decreases to a value a3 which is less than the value a2. Belt slack therefore forms in the webbing 14. Due 3 to this slack the webbing can be placed without any discomfort round the vehicle occupant and the end fitting guided up to the fastened position at the detent means 22. As soon as the switch 26 is activated the takeup function of the belt retractor 10 is established again and consequently the belt slack eliminated.

Fig. 2 shows a belt retractor 10 which is of conventional construction except for equipping with the locking means

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rcoo 00 00 0 4 0i 4 4$ 0 0o 0044 4 44 referred to above. It will therefore not be described in detail. The webbing 14 is coiled on a belt reel which is rotatably mounted in the two side plates of a U-shaped housing. The belt reel comprises a lateral flange to which a ratchet wheel 32 is non-rotatably connected. Said ratchet wheel 32 carries outer teeth 34 which co-operate with a locking pawl 36. The locking pawl 36 is pivotally mounted about a pin 38. The locking pawl 36 is held by a leaf spring 40 resiliently in its rest position out of engagement with the teeth 34. The leaf spring 40 comprises an approximately right-angled bent leg which is connected to a hinged armature 42 of an electromagnet 44. The hinged armature 42 is likewise pivotal about the pin 38. It is held by a spring 46 in its rest position. On activation of the electromagnet 44 the hinged armature 42 is pivoted anticlockwise in Fig. 2, the leaf spring 40 thereby being correspondingly pivoted and pressing resiliently against the rear side of the locking pawl 36 so that the latter is moved towards the ratchet teeth 34 and into engagement with the latter.

The ratchet teeth of the toothing 34 each have a flat face and a steep back. On rotation of the belt reel anticlockwise the locking pawl 36 is caught behind the first tooth back of the teething 34 encountered so that the takeup function of the belt retractor 10 is prevented.

In contrast, in the opposite direction of rotation (clockwise), corresponding to withdrawal of the webbing from the belt reel, the tooth flanks of the teeth 34 form repelling ramps for the locking pawl 36 so that even when the electromagnet 44 is activated webbing 14 can be withdrawn from the belt retractor In the embodiment according to Fig. 3 compared with that of Fig. 2 only the construction of the locking pawl 36a and the electromagnet 44a is different. In the embodiment according to Fig. 3 the electromagnet 44a is arranged in a lying position. Its hinged armature 42a, in the Lizi- 7 7 1 actuated state of the electromagnet 44a, presses against a cam 50 of a foot portion of the locking pawl 36a mounted pivotally about the pin 38a, On activation of the electromagnet 44a said foot portion 52 is pivoted clockwise. The foot portion 52 comprises a tapered extension 54 which is elastically deformable and bears at its free end on the housing. The body of the locking pawl 36a is connected to said tapered extension 54. The locking pawl 36a is therefore pivoted in the opposite direction to the foot portion 52 and on actuation of o the electromagnet 44a comes into the engagement position at the teeth 34a of the ratchet wheel 32a. Otherwise, 'n "ao the function of this embodiment is the same as in Fig.

2.

115 V I-

Claims (3)

1. 2. A passive safety belt system according to claim i, wherein said guide rail has a curved initial portion extending from said first end position and a curved end B portion adjacent said second end position, said end I portion being curved with a radius of curvature smaller Sthan that of said initial portion, and an approximately rectilinearly extending intermediate portion between said initial portion and said end portion of said guide rail.
2. 3. A passive safety belt system according to claim i, wherein said detent member is spring biased to a position disengaged from said ratchet wheel. %i U 00501,gjnspe.001,ky31314.spe,8
3. 9- 4. A passive safety belt system substantially as hereinbefore described with reference to the accompanying drawings. DATED this 1st day of May 1990 TRW REPA GMBH By Its Patent Attorneys DAVIES COLLISON CCC, o fo~~ 0 C C C 0 0 CC CC O 0 0 0 0 C CCC, ~C O 0 00 CC O 0 C O 0 L,gjnspe.OO1.ky31314. spe.9 I