GB2113531A - Safety belt retractor tensionless means override for automobile passenger restraint systems - Google Patents

Abstract

A passive safety belt restraint system in an automotive vehicle employing an emergency locking belt retractor having a tensionless mode producing means provided with a tensionless mode override means operable in response to protractive movement of the safety belt beyond a position of use, as when the vehicle door is opened pulling portions of the passive restraint system beyond a normal position of use, so that a tensionless mode is not experienced when the vehicle door is opened.

Description

SPEC!FICATION Safety belt retractor tension less means override for automobile passenger restraint systems The present invention relates in general to passive type safety belt restraint systems for restraining passenger3 in their seat in moving vehicles and more particularly to a means for controlling operation of a tension less type emergency locking safety belt retractor employed therewith.

Various types of passive restraint systems have bean developed heretofore for use in automotive vehicles wherein portions of the safety belt webbing are wound upon emergency locking safety belt retractors. In some passive restraint systems, as in U.S. Patent Nos. 4,189,170 and 4,245,856, the safety belt retractor is mounted to the vehicle frame inboard of the passenger seat with the webbing cuter end being attached to the vehicle door frame.

Alternatively, the retractor mechanism may be mounted in the vehicle door with an opposite end of the safety belt being secured to a floor anchor inboard of the passenger's seat as in U.S. Patent No.

4,180,283. In each of these passive restraint systems, a sufficient amount of webbing must be wound within the retractor to allow for the opening of the vehicle door to a full open position without the need for disconnecting the safety belt so that it may operate in the so called "passive" mode, i.e. does not require occupant manipulation of the belt to place it in use.

To enhance the comfort of the occupant when riding in a vehicle having a passive type safety belt restraint system, it is now common to employ a tensionless type safety belt retractor wherein the rewind spring of the retractor mechanism is blocked out while the safety belt is in a position of use.

Exemplary of such tensionless type retractors are U.S. Patents Nos. 3,679,228; 3,682,412; 4,065,072; 4,023,746; 4,108,395; and Re. 29,095. In these, as weli as other prior art tensionless retractors, it is common for the tensionless mechanism to be operable after the safety belt has been withdrawn from the retractor to a position of use to relieve the safety belt of the retractor rewind spring tension.

However, in a passive restraint system as described hereinbefore, particularly where a portion of the safety belt is attached to a portion of the vehicle door, it is desirable to prevent the retractor from going into its tensionless mode while the vehicle door is in the open position.

It is the primary object of the present invention to disclose and provide a means for overriding the tensionless mechanism of a tensionless type safety belt retractor when the safety belt associated with the retractor is other than in intended positions of use when a tensionless mode is desired. More specifically, it is an object of the present invention to disclose and provide a means for preventing a tensionless type safety belt retractor from assuming its tensionless mode when the associated safety belt webbing is protracted beyond a position of use, as when the safety belt of a passive restraint system wherein portions of the belt are connected to the vehicle door are protracted by virtue of the passenger opening the vehicle door so that on closing the vehicle door, the retractor mechanism will be free to rewind the belt under the normal bias of the retractor rewind spring.

Generally stated, the present invention includes the provision of tensionless mode override means operable in response to protractive movement of a safety belt associated with a tensionless retractor when the protractive movement of the safety belt is of an additional protractive amount beyond that required for placing the safety belt in an intended position of use thereby preventing the tensionless retractor from entering its tensionless mode until the safety belt is returned to an intended position of use.

More specifically, the present invention finds particular use in a passive safety belt passenger res train system for vehicles wherein a vehicle inertia responsive emergency locking safety belt retractor is employed with tensionless mode producing means for blocking the rewind bias of the retractor spring when the belt is protracted to an intended position of use and wherein a portion of the safety belt is connected to a vehicle door such that when the vehicle door is opened the safety belt is further protracted relative the retractor an additional proto raction beyond that desired for an intended position of use. in such an environment, the present invention in tensionless mode override means is operable in response to the protractive movement of the safety belt when the vehicle door is opened causing the belt to move beyond the normal use protractive condition with the override means continuing to prevent operation of the tensionless mode producing means of the retractor until the vehicle door is closed allowing the associated safety belt to reassume an intended position of use.

It is believed that a better understanding of the present invention, as well as an appreciation of various additional objects and advantages thereof, will become apparent to those skilled in the art from a consideration of the following detailed description of a preferred exemplary embodiment thereof.

Reference will be made to the appended sheets of drawings which will be first briefly ciescribed.

Figure lisa perspective view of an exemplary prior art passive safety belt restraint system wherein the tensioniess mode emergency locking safety belt retractor is mounted inboard of the passenger seats with an outer end of the safety belt attached to the vehicle door frame; Figures 2 and 3 are right hand and left hand, respective, perspective views of another exemplary embodiment of passive restraint system wherein a tensionless type emergency locking safety belt retractor is located inboard of the vehicle seat with portions of the safety belt being attached to the vehicle door; Figure 4 is a vertical view, partially in section, of an exemplary emergency locking safety belt retractor which may be employed in passive restraint systems as illustrated in Figures 1 through 3;; Figure 5 is a vertical section view taken in the plane V-V in Figure 4 showing an exemplary embodiment of tensionless mode override means em polyed in asscciation with an exemplary tensionless madeproducing means of the safety belt retractor of @, ths tensioniess mesans being in hs tensionode wher in the rewind bias of the retractor re ind spring is blocked out; igure 6 is a vertical section view of the apparatus 0. lgure = taken therein along the plane VI-VI ; Mgure 7 is a detail section view cf the apparatus of the Figure 6 taken therein along the plane VII-VII ;; Figure 8 is a detail view of the apparatus of Figure 6 taken therein along the plane VIII-VIII ; Figure 9 is a view as in Figure 8 showing the tensionlats means in a position of initial webbing protraction from the tensionless mode ; Figure C is is a detail section view of the apparatus of Figure 8 aken therein along the plane X-X; Figure 11 is a detail section view of the apparatus of Figure 9 taken therein along the plane XI-XI ; Figure 12 is a view as in Figures 8 and 9 showing the tensioniess means in a still further belt protraeted position relative the position of Figure 9;; Figure 13 is an exploded perpective view of the exemplary embodiments of tensionless override means and tensionless mode producing means ; Figure 4 is a view as in Figures 9 and 42 showing the exemplary tension less mode producing means in a belt retracting position; and Figure 15 is a vertical section view as in Figure 5 showing the preierred exemplary ambodiment of tensionless mode override means maintaining the tensionless mode producing means in an inoperatve condition.

Referring initially to Figure 1, an exemplary embodiment of passive safety bet restraint system is Hlustrated in association with an automobile indicated generally at 10.

The passive system illustrated is in accordance with prior l l.S. Patent No. 4,245,856, the disclosure of which le incorporated herein be this reference. For purposses of the description of the present invention, it shoihd te observed that the passive safety belt system includes a pair of belt assemblies 11 and 11a, repesitvley, associated with the two front seats of the vehicle. A vehicle occupant 12, is shown having a chest belt 13 extending from a door frame anchor 14, where it is anchored by releasable buckle 15 and safety stra,J 16, to a retractor provided within housing 17 7 and anchored by floor anchor 18.The tensionless retractor of this exemplary passive sys tern has a manual actuator 19 for placing the tensionless means in an operative position as more fuily explained in said U.S. Patent No.4,245,856. The second sest belt assembly 11a is provided in the same manner with the sane parts being given the same numbers with the added letter "a" reference.

When the vehicle door is opened, as seen in Figure 1, the safety belt 13, 13 is protracted an additional amount beyond that normally protracted for a normal position of use as shown in association with vehicle occupant 12.

Similarly, in other passive restraint systems, such as that illustrated in Figures 2 and 3, opening of the vehicle door moves the safety belt in a manner to cause protraction of webbing off of the safety belt retractor an amount greater than normally experienced for exiending the safsty belis to a position of use. The passlve safety behs system of Figures 2 and Bis substantiaily die same as that in copending U.S.

Patent Application Seriel No. 182845 filed August 29 1980, the disclosure of which is incorporated herein by this reference. However, or purpores of the present description of a preferred exomplary embodiment of the present invention, :t should be noted that the passive safety belt resuaint system assoclated with an automobile type vehicle indicated generally at 20 includes a seat belt assembly indicated generally at 21 in association with the vehicle occupant 22. The chest belt portion 23 of the safety belt assembly includes a lower belt section 23a which is anchored to the door by door anchor 24.

Upper potions of the chest belt 23 pass through a guide 25 on flexible arm 26 mounted to a travelling base 27 which moves along stationary track 28 in the header portion of the vehicle as nice ftiiy described in said copending application Serial No. 182,645.

Belt 23, alter passing th rough guide 25, passes through a second guide 29 with horizontal belt portion 23D extending to a conventional emergency locking retractor indicated generally at 30. An inner lap belt portion 81 is secured by slip through fitting 32 to a mid portion of the chest belt 23, 23a and is wound upon an emergency locking retractor positioned within housing 13 and anchored by floor sneer 34 to the vehicie floor.

As can be seen from the two foregoing general descriptions of prior art passive safety belt restraint systems, the safety belt webbing is protracted a substantial amount beyond a position of normal use when l the vehicle door is opened to a fully opened position. Movement of the opened door could possibly place the retractor mechanism of prior U.

S. Patents Nos. 3,679,228; 3,682,415; 4,065,072; 4,023,746 ; 4,108,396 ; and Re. 29,095. The present exemplary embodiment of tensionles means as best seen in Figures 5 and 6 and the exploded view oh Figure 12, includes the provision of a tensionless ratchet wheel 51 mounted by its hub 51 a to a square shaft end 49 of spool shaft 56, the latter passing through bushing 47 made of a lowfriction plastic and being ingregral with a base plate portion 47a.A ring 48 on the spool shaft rides against base 47a in holding the pan"s in assembled relation, ratchet wheel 51 thus turning along with the belt reel indicated generally at 4C. Teeth 32 on the tensionless ratchet heel 51 are adapted to be engaged by tensionless pawl 53 v-vhich is pivoted on support pin 54 to align the paw! tcoth 55 with the ratchet teeth 51. Engagement of tensioniess pawl 53 with teeth of the ratchet wheel 51 prevents rewinding of the reel and relieves the occupant from the belt tension otherwise applied by the retractor rewind spring.

Operation of tensionless pawi 53 is controlled in known manner by a palr cf cam discs including friction dise 60 and actuator cam disc 70. Friction disc 60 is provided with a contact surface 61 of annular configuration on its forward face to engage a matingly configured annular friction drive surface 56 provided on the inward side of ratchet wheel 51 as best seen in Figure 6. Coil spring 62 is provided to normally bias the friction disc 60 against ratchet wheel 51 to rotate therewith. A notch 63 is provided in the friction disc to allow follower pin 64 on pawl 53 to full therein and allow engagement of pawl 53 with ratchet teeth 52 as discussed hereinafter.

Cam actuator disc 70 is provided with a bore 71 which rides on a low friction material boss 47b formed integrally of bushing 47 and has a notch 72 adapted to receive follower pin 64. Rotation of cam actuator dise 70 relative the retractor frame is limited by the cooperation of a retractor in a tensionless mode such that the rewind spring would not automatically cause rewinding of the safety belt webbing when the door is closed. Where a manual override is provided as in the embodiment of Figure 1, the operator can simply move the manual actuator to disengage the tensionless means and thereby cause a rewinding of the retractor and a storing of the associated safety belt webbing.However, it is contemplated within the present invention to provide an additional means for preventing the tensionless means from assuming a tensionless mode when the door is opened to the positions illustrated in Figures 1 and 3 as discussed hereinbefore.

An otherwise conventional emergency locking retractor is shown in Figure 4 wherein the safety belt 35 is wound upon the retractor, indicated generally at 36, provided within housing 37. As is conventional with emergency locking retractors in commercial use, a U-shaped frame 38 is bolted by bolts 39 to the housing and vehicle floor to mount a safety belt reel, indicated generally at 40, which has ratchet wheels 41 and 42 positioned at its opposite ends to engage in a tiltable lock bar 43 mounted in the U-shaped frame in position to engage the ratchet wheels and lock the reel against protraction in the event of an emergency. A conventional actuating means, not shown, such as a vehicle inertia sensing pendulum may be employed for actuating lock bar 43 into engagement with the ratchet wheels 41 and 42 to lock the reel against protraction.Since the lock bar engages the ratchet wheels only in the event of an emergency, during normal seat belt use, the tension of the retractor spring within spring housing 44 is normally applied to the belt 35 subject to the provision of a tensionless means as it is also known in the art.

As discussed hereinbefore, various types of tensionless retractors have been employed heretofore for relieving the seat belt 35 of the tension of the retractor spring within spring housing 44. Exemplary thereof are the circular rear limit slot 73 provided in disc 70 which receives stop pin 74 provided on base 47a. The disc is rotated within limits thus provided by engagement with the friction disc, such engagement being accomplished between a circular front limit slot 75 and a drive pin 65 on the friction disc. Thus, as is known in the art, on a protraction of the webbing toward a position of use, the friction disc will rotate clockwise to the position of Figure 12 causing its drive pin 65 to carry disc 70 until its rear limit slots 73 bottoms out on stop pin 74 as seen in Figure 12.A retractive movement of the webbing as it is placed in use will cause the friction disc to revolve in the opposite direction until it moves actuator dise 70 to the position of Figure 14 which, if followed by a slight protraction of the webbing, as seen in Figure 8, will allow alignment of actuator disc slot 72 and friction disc slot 63 with pawl follower pin 64 allowing the pawl to engage the ratchet wheel 51 in a tensionless mode as seen in Figures 5, 6 and 7. Thereafter, small belt protractions of less than one full spool turn, as seen in Figure 9, still allows the tensionless mode to be resumed in a position of use. Protraction of a greater amount should end the tensionless mode.While this tensionless mode is normally desired when the safety belt is positioned in a location of use, and can be obtained by other belt manipulation as known in the art, it is not desired to have such a tensionless mode created when the belt is protracted beyond a position of use, as when the vehicle door is swung to an opened position as illustrated in Figures 1 and 3.

As is particularly contemplated within the present invention, tensionless mode override means are provided in order to prevent operation of the tension less means when the belt is extended beyond a normal use position. Referring to Figues 5 and 12 particularly, the exemplary embodiment of tensionless mode override means is indicated generally at 80 and includes the provision of an additional follower pin 81 on pawl 53 which extends in an opposite direction then pin 64 and an override cam 82. The exemplary override cam is provided with an arcuate recess 83 having cam surfaces at either end merging with the outer circumferential surface of the cam. An internal gear is formed by teeth 84 in the annular cam 82 which is driven by idler gear 85 mounted on stub shaft 86 by a bearing sleeve 87 in gear 85.Idler gear 85 is driven by a drive pinion gear 88 fixed to tensionless ratchet wheel 51 via an engagement between pinion teeth 89 and internal gear teeth 84. An arcuate bearing support surface 90 is formed in the housing 37 to facilitate a smooth driving relation between the pinion gear 88, idler gear 85 and annular override cam 82. The length of recess 83 and its location relative to pawl follower pin 81 is predetermined by locating the recess in response to spool turns communicated via pinion 88 to cam 82 so that during the normal range of positions of use predetermined for the safety belt the pawl pin 81 will be free of cam 82 by virtue of alignment with recess 83.However, on protraction of the webbing past a predetermined position of use, as by a protraction exceeding the outer limits of a predetermined range of possible positions of use for the webbing for a particular vehicle installation, the spool turns imparted thereby communicated by pinion 88 through gear 85 to override cam 82 moves recess 83 from beneath pin 81 causing pin 81 to ride on the outer circumference of cam 82 preventing the exemplary tensionless means, indicated generally 50, from operating as seen in Figure 15. Therefore, when the vehicle door is in an opened position as seen in Figures 1 and 3, the override cam 82 maintains pawl 53 in an inoperative position, but when the vehicle door is closed, rewinding of the retractor reel under the influence of the retractor spring will return the recess 83 from a position as seen in Figure 13 to the non-override position of Figure 5.

Having thus described a preferred exemplary embodiment of tensionless mode override means in accordance with the present invention, it is believed that those skillet in the art will perceive that various modifications, adaptations, and alternative embodi- ments may be made within the scope of the present imrention zilch is defined by the following claims.

Claims (6)

1. In a passive safety belt passenger restraint system for vehicles wherein a vehicle inertia responsive emergency locking safety belt retractor is employed with tensionless mode producing means for blocking the rewind bias of the retractor spring when the belt is protracted to an intended position of use and wherein a portion of the safety belt is connested to a vehicle door such that when the vehicle door is opened the safety belt is further protracted relative said retractor an additional prot reactive amount beyond that desired for an intended position of use, the improvement comprising the provision of:: tensionless mode override means operable in response to protrative movement of said safety belt of said additional protractive amount beyond that desired for an intended position of use for preventing aid tensionless mode producing means from blocking the rewind bias ofthe retractor spring when sad belt is protracted beyond the intended position of tise as when the vehicle door is opened.

2. The improvornent in restraint system of Claim 1 wherein said tensionless override means comprises a cam disc engaging with said tensionless mode producing means and a reel shaft driven means is provided for operating said cam disc in response to the direction and extent of belt protracting and retracting movement of the retractor belt storage reel.

3. In a safety belt retractor having a belt tensionless mode producing means the improvement com prising the provision ol-: override means for preventing operation of said tensionlese mode producing means in a predetermined range of belt protraction relative said retractor.

4. The improvement in retractor of Claim wherein said override means further comprises a rotatable member, means for rotating said member in response to movement of said belt relative said retractor and means for mounting said member in operable relation with said tensionless mode produring means.

5. The irr.prnvement in retractor of Claim 3 wherein retractor includes a belt storage reel and said override means comprises: means operable in response to rotation of said reel for blocking operation of said tensionless mode producing means into a belt iensionless mode when said reel is rotated in a belt protraction direction an amountgreaterthan a predetermined amount

6. The improvement in retractor of Claim 5 wherein said predetermined amount of reel rotation is determined as that required for a maximum protraction of belt for an intended position of use of the belt.