Air bag with tether and pulley arrangement

1. An apparatus for helping to control deployment of an inflatable protection device, the apparatus comprising:

a tether having a first connection with a first portion of the protection device and a second connection with a second portion of the protection device, each of the first and second portions being configured to receive occupant penetration; and

a guide connected to the protection device, the tether extending through the guide;

the tether configured to move through the guide in response to occupant penetration into the first portion of the protection device to move the second portion of the protection device in a direction that alters how the second portion of the protection device is configured to receive occupant penetration.

2. The apparatus recited in claim 1 , wherein the tether is configured to move through the guide and translate movement of the first portion to movement of the second portion in response to occupant penetration into the first portion.

3. The apparatus recited in claim 1 , wherein the tether and guide are constructed and arranged such that the first portion of the protection device substantially achieves a fully deployed condition when free from obstruction during deployment, the first portion of the protection device in substantially achieving its fully deployed condition pulling the tether through the guide which causes the tether to draw-in the second portion of the protection device, thus substantially inhibiting the second portion from reaching a fully deployed condition.

4. The apparatus recited in claim 1 , wherein the tether and guide are constructed and arranged such that the first portion reaches its fully deployed condition when the protection device deploys without being obstructed.

5. The apparatus recited in claim 1 , wherein the tether and guide are constructed and arranged to permit the second portion of the protection device to deploy toward a fully deployed condition to an extent that is in proportion to the extent to which deployment of the first portion of the protection device toward a fully deployed condition is inhibited.

6. The apparatus recited in claim 5 , wherein the proportion of second portion deployment to first portion obstruction is 1:1.

7. The apparatus recited in claim 5 , wherein the proportion of second portion deployment to first portion obstruction is 2:1 or greater.

8. The apparatus recited in claim 5 , wherein the proportion of second portion deployment to first portion obstruction is 1:2 or less.

9. The apparatus recited in claim 1 , wherein the first portion comprises a panel of the protection device, the apparatus further comprising an actuatable vent, the tether and guide being constructed and arranged to actuate the vent in response to deployment of the panel.

10. The apparatus recited in claim 9 , wherein the tether and guide are constructed and arranged to actuate the vent to a closed condition in response to deployment of the panel.

11. The apparatus recited in claim 9 , wherein the tether and guide are constructed and arranged to actuate the vent to an open condition in response to deployment of the panel.

12. The apparatus recited in claim 1 , wherein the guide comprises a loop of material.

13. The apparatus recited in claim 1 , further comprising a vent for venting inflation fluid from the protection device, the vent being actuatable in response to deployment of the first portion being blocked from reaching a fully deployed condition.

14. The apparatus recited in claim 1 , further comprising a vent for venting inflation fluid from the protection device, the vent being actuatable in response to the second portion reaching a fully deployed condition.

15. The apparatus recited in claim 1 , wherein:

the guide comprises a first guide connected to the first portion of the protection device and a second guide connected to the protection device at a location spaced from both the first and second portions of the protection device;

the tether comprises a first terminal end portion anchored to the protection device at a location adjacent or near the second guide and an opposite second terminal end portion anchored to the second portion of the protection device;

the tether comprising a first segment that acts as a trigger tether and a second segment that acts as a shaping tether, the trigger tether extending from the first terminal end portion through the first guide and to the second guide, the shaping tether extending from the second guide to the second terminal end of the tether.

16. The apparatus recited in claim 15 , wherein the guide connected to the first portion of the protection device defines the first connection of the tether to the protection device.

17. The apparatus recited in claim 1 , wherein:

the guide comprises a first guide connected to the protection device at a location spaced from both the first and second portions of the protection device and a second guide connected to the second portion of the protection device;

the tether comprises a first terminal end portion anchored to the first portion of the protection device an opposite second terminal end portion anchored to the protection device at a location adjacent or near the second guide;

the tether comprising a first segment that acts as a trigger tether and a second segment that acts as a shaping tether, the trigger tether extending from the first terminal end portion to the first guide, the shaping tether extending from the first guide through the second guide and to the second terminal end of the tether.

18. The apparatus recited in claim 17 , wherein the second guide defines the second connection of the tether to the protection device.

19. The apparatus recited in claim 1 , wherein the guide comprises a plurality of guides and the tether extends through each of the plurality of guides, the tether being configured and arranged to extend through the plurality of guides so that the movement of the first portion in the first direction is translated to movement of the second portion in the second direction at a ratio other than 1:1.

20. The apparatus recited in claim 1 , wherein a portion of the tether extending from the first connection comprises a trigger tether configured to shorten in response to occupant penetration into the first portion, a portion of the tether extending from the second connection to the trigger tether comprising a shaping tether configured to lengthen in response to shortening of the trigger tether, the second portion of the protection device being configured to move toward a fully deployed condition in response to lengthening of the shaping tether.

21. The apparatus recited in claim 20 , wherein the guide defines a transition point where the trigger tether transitions to the shaping tether.

22. The apparatus recited in claim 20 , wherein the guide comprises a plurality of guides, at least one of the shaping and trigger tethers extending through a plurality of the guides so that the movement of the first portion in the first direction is translated to movement of the second portion in the second direction at a ratio other than 1:1.

23. The apparatus recited in claim 1 , wherein the first direction of movement of the first portion is in a direction away from a first vehicle occupant position and the second direction of movement of the second portion is in a direction towards a second vehicle occupant position.