Seat belt junction ring

A junction ring adapted for use in a seat belt system wherein a continuous-loop belt is slidable through the junction ring to define shoulder belt and lap belt portions includes a housing having slots mounting a pin for movement toward and away from the buckle. The belt passes around the pin. A buckle is selectively engageable with the junction ring to establish the lap belt and shoulder belt in occupant restraining positions across the seat. The shoulder belt is wound by a seat belt retractor having a tension reliever permitting introduction of slack into the shoulder belt. A spring urges the pin in the direction toward the buckle so that the belt is carried into frictional engagement with a friction member to provide a one-way friction detent which prevents transference of the shoulder belt slack into the lap belt so that the lap belt remains taut about the occupant. The spring acting on the pin yields upon the onset of an occupant restraint load to permit movement of the pin away from the buckle and the friction member so that the continuous-loop belt is permitted to pass through the junction ring to adjust the relative restraint lengths of the lap and shoulder belt portions. The frictional engagement of the friction member with the belt is terminated upon disengagement of the junction ring from the buckle so that the belt may pass freely therethrough.

The invention relates to an occupant restraint belt system having a 
continuous-loop belt and, more particularly, provides a junction ring 
assembly which is effective when the belt is buckled in the occupant 
restraint position to permit belt transference through the junction ring 
only in the direction to tighten the lap belt so that slack introduced 
into the shoulder belt by a tension relieving shoulder belt retractor 
cannot be transferred into the lap belt. 
BACKGROUND OF THE INVENTION 
It is known in vehicle seat belt systems to employ a continuous loop of 
belt having a junction ring slidable therealong to adjust the relative 
restraint lengths of the lap and shoulder belt portions. It is also known 
to provide a retractor mounting the shoulder belt end of the continuous 
loop belt and to provide a tension relieving device within the shoulder 
belt retractor so that the shoulder belt can be held against rewinding at 
a certain slacked length to enhance occupant comfort. 
It would be desirable in such an occupant restraint system to provide a 
junction ring assembly which would function to prevent the transference of 
this slack from the shoulder belt into the lap belt. Furthermore, it would 
be desirable to provide a junction ring assembly which would free the 
continuous loop belt for passage through the junction ring upon the onset 
of an occupant restraint load to permit adjustment of the relative 
restraint lengths of the lap and shoulder belts to obtain optimum occupant 
restraint effectiveness. 
SUMMARY OF THE INVENTION 
The invention provides a junction ring adapted for use in a seat belt 
system wherein a continuous loop belt is slidable through the junction 
ring to define shoulder belt and lap belt portions. A buckle is 
selectively engageable with the junction ring to establish the lap belt 
and shoulder belt in restraining positions across the seat to restrain the 
occupant. The shoulder belt is wound by a seat belt retractor having a 
tension reliever permitting introduction of slack into the shoulder belt. 
The junction ring includes a housing mounting a pin having the continuous 
loop belt passing therearound. The pin is mounted on the housing for 
movement toward and away from the buckle. A spring urges the pin in the 
direction toward the buckle. A friction member is adapted to frictionally 
engage with the belt on the opposite side thereof from the pin when the 
junction ring is engaged with the buckle to provide a one-way friction 
detent which enables the introduction of slack into the shoulder belt by 
the tension reliever of the seat belt retractor and yet prevents 
transference of the slack into the lap belt so that the lap belt remains 
taut about the occupant. The spring acting on the pin yields upon the 
onset of an occupant restraint load to permit movement of the pin in a 
direction away from the buckle and the friction member so that the 
continuous loop belt is permitted to pass around the pin and through the 
junction ring to adjust the relative restraint lengths of the lap and 
shoulder belt portions. The frictional engagement of the friction member 
with the belt is terminated upon disengagement of the junction ring from 
the buckle so that the belt may pass freely therethrough.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, the vehicle body indicated by numeral 10 includes a 
floor 12 having an outboard sill 14 and an inboard transmission tunnel 16. 
A pillar 18 extends vertically adjacent the rear of the seat 19 outboard 
thereof and includes a trim panel 20 facing the occupant compartment of 
the vehicle body. 
An occupant restraint system includes a continuous loop restraint belt 22 
having a lower end attached to the sill 14 by an anchor plate 24 and bolt 
assembly 26. The upper end of the continuous loop belt 22 passes through a 
slide loop 28 attached to the pillar 18 by a bolt 30 and downwardly to a 
shoulder belt retractor 32 which normally winds the continuous loop belt 
22 to a phantom line indicated stowed position extending generally 
vertically along the trim panel 20. 
A seat belt buckle 36 is mounted on the transmission tunnel 16 by a 
semi-rigid anchor strap 38. A junction ring 40 is slidable along the 
continuous loop belt 22 and divides the continuous loop belt 22 into a lap 
belt 44 and a shoulder belt 46 when the junction ring 40 is engaged within 
the buckle 36. 
Referring to FIGS. 2 and 3, it is seen that the junction ring includes a 
stamped steel frame 48 including an apertured tongue portion 50 which is 
adapted for insertion into the buckle 36. The buckle 36 has a conventional 
latch for engaging with the apertured tongue portion 50 and a pushbutton 
for releasing the latch to enable disengagement of the junction ring 40 
from the buckle 36. The frame 48 also has a pair of spaced apart upturned 
flanges 54 and 56 having aligned longitudinal extending slots 58 and 60. A 
pin 64 extends between the flanges 54 and 56 and projects slidably through 
the slots 58 and 60 to enable movement of the pin toward and away from the 
buckle 36. The continuous loop belt 22 passes around the pin 64 as best 
seen in FIG. 2. 
As seen in FIG. 3, a loop coil spring 66 wraps around the end of the pin 64 
and is anchored on the flange 54 by a plastic spring retainer 68. A like 
loop coil spring 74 encircles the opposite end of the pin 64 and is 
mounted on the flange 56 by a plastic spring retainer 76. The springs 66 
and 74 cooperate to urge the pin 64 in the direction toward the buckle 36. 
As best seen in FIGS. 2 and 4, a friction member 80 is suitably mounted on 
the buckle 36 and has an aperture 82 which registers with the opening in 
the end of the buckle 36 to receive the apertured tongue portion 50 of the 
junction ring frame 48. The friction member 80 also has a friction arm 84 
which projects from the buckle 36 and is adapted to overlie the pin 64 as 
best seen in FIG. 2. The springs 66 and 74 bias the pin 64 toward the 
buckle 36 so that the pin 64 carries the continuous loop belt 22 passing 
therearound into frictional engagement with the friction leg 84 of the 
friction member 80. 
OPERATION 
Referring to the phantom line indicated stowed position of FIG. 1, it will 
be understood that prior to engagement of the junction ring 40 with the 
buckle 36, the continuous loop belt 22 will be able to pass freely around 
the pin 64 so that the junction ring can be moved freely along the belt to 
facilitate positioning of the lap and shoulder belt portions about the 
seated occupant. 
When the junction ring 40 is engaged with the buckle 36 by the insertion of 
the junction ring tongue portion 50 into the buckle 36, the friction leg 
84 of the friction member 80 carried by the buckle 36 projects into 
overlying relationship with the pin 64 of the junction ring 40. The coil 
loop springs 66 and 74 cooperate to urge the pin 64 toward the buckle 36 
so that the belt 22 is frictionally engaged by the teeth 86 on the 
friction arm 84. The pin 64 and teeth 86 cooperate to permit one way 
travel of the belt around the pin 64 in the direction of the arrow 
designated 90 to transfer any slack belt from the lap belt portion 44 to 
the shoulder belt portion 46. 
After the occupant has engaged the junction ring 40 with the buckle 36 to 
establish the lap belt 44 and shoulder belt 46 in the occupant restraint 
positions, the occupant may set the tension reliever in the retractor 32 
and thereby establish slack in the shoulder belt 46. This slack cannot be 
transferred into the lap belt 44 because the frictional engagement of the 
belt 22 between the pin 64 and the friction teeth 86 clamps the belt 22 
against movement around the pin 64. 
Upon the onset of a rapid vehicle deceleration condition in which the lap 
belt 44 and shoulder belt 46 restrain the seated occupant, a substantial 
occupant restraining load is imposed on the lap belt 44 and the shoulder 
belt 46. This substantial belt load overcomes the bias of the coil loop 
springs 66 and 74 and permits movement of the pin 64 along the slots 60 
and 58 in the direction away from the friction member 80. Accordingly, the 
belt 22 moves away from frictional contact with the friction arm 84 and 
the continuous loop belt 22 is permitted to pass around the pin 64 to 
adjust the relative restraint lengths of the lap and shoulder belts. When 
the occupant restraint load is terminated, the coil loop springs 66 and 74 
return the pin 64 to the position of FIG. 2. 
Disengagement of the junction ring 40 from the buckle 36 as permitted by 
conventional manual depression of the buckle pushbutton permits bodily 
removal of the junction ring 40 away from the friction member 80 to 
restore the junction ring to the normal condition permitting free passage 
of the belt 22 around the pin 64. 
DESCRIPTION OF A SECOND EMBODIMENT 
Referring to FIG. 5, there is shown a second embodiment of the invention in 
which like elements are designated by like numerals. In the embodiment of 
FIG. 5, the friction member designated 100, is also of injection molded 
plastic but is moveably mounted within the junction ring 40. A pair of 
coil compression springs, one of which is shown at 104 acts between the 
upturned flanges 54 and 56 to urge the friction member 100 in the 
direction to carry its friction teeth 106 and abutment portion 108 in the 
direction away from the pin 64. FIG. 5 shows the junction ring 40 engaged 
within the buckle 36 such that the wall 110 of the buckle 36 has acted 
upon the friction member abutment portion 108 to retract the friction 
member 100 within the junction ring 40 and thereby carry the friction 
teeth 106 into engagement with the continuous loop belt passing around the 
pin 64. Accordingly, slack introduced into the shoulder belt 46 cannot be 
transferred into the lap belt 44 because any such attempted movement is 
blocked by the wedging of the teeth 106 against that portion of the belt 
22 clamped between the teeth 106 and the pin 64. However, upon the onset 
of an occupant restraint load, the pin 64 is permitted to move away from 
the friction teeth 106 as enabled by yielding of the loop coil springs 66 
and 74, not shown in FIG. 5. Thus, it is seen that the embodiment of FIG. 
5 differs from the embodiment of FIGS. 2-4 in that the friction member for 
engagement with the belt is moveably mounted on the junction ring instead 
of being fixedly mounted on the buckle housing. 
Thus, it is seen that the invention provides a new and improved junction 
ring for a continuous loop belt system having a tension relieving shoulder 
belt retractor. More particularly, the junction ring functions to prevent 
transference of the slack introduced into the shoulder belt by the tension 
relieving retractor into the lap belt and yet frees the belt upon onset of 
an occupant restraint load so that the belt may transfer through the 
junction ring to adjust the relative occupant restraint lengths of the lap 
belt and shoulder belt portions.