Mechanism for securing passenger side air bag door

[0002] 1. Technical Field

[0003] The present invention relates to an apparatus for helping to protect an occupant of a vehicle. In particular, the invention relates to an apparatus including a mechanism for securing, or maintaining in a closed condition, a door for a passenger side air bag.

[0004] 2. Description of the Prior Art

[0005] A known apparatus for helping to protect a front seat passenger of a vehicle includes an inflatable air bag stored in the vehicle instrument panel. The air bag inflates into the vehicle passenger compartment through a deployment opening in the instrument panel. A movable door covers the deployment opening. The door is normally held closed by a tear seam or a latch.

[0006] The force that is needed to open the door comes from the air bag. The air bag is initially pressurized beyond the amount needed simply to inflate the bag through the deployment opening. The force of the inflating air bag pushes open the door to enable movement of the air bag through the deployment opening into an inflated condition.

[0007] A front seat passenger intended to be protected by the air bag may be out of position, that is, may be positioned too close to the instrument panel. To minimize the amount of force applied to an out of position passenger, it would be desirable to limit the amount of force needed to open the door and, thereby, limit the initial force with which the air bag inflates.

[0008] Another known apparatus for helping to protect a front seat passenger of a vehicle is an actuatable knee bolster. A knee bolster is located at a lower portion of a vehicle instrument panel and is movable from a stored position adjacent to the instrument panel to a blocking position spaced apart from the instrument panel, in response to detection of a vehicle crash condition. The knee bolster can help to prevent the vehicle occupant from “submarining” underneath an inflated air bag.

[0009] The present invention is an apparatus comprising an inflatable vehicle occupant protection device having a deflated condition stored in an instrument panel of a vehicle. The inflatable device has an inflated condition extending out of the instrument panel for helping to protect an occupant of the vehicle. A door connected with the vehicle instrument panel is movable between a closed condition covering the inflatable device when in the deflated condition and an open condition. A knee bolster is supported on the vehicle instrument panel for movement in the vehicle from a stored position adjacent to the instrument panel of the vehicle to a blocking position spaced apart from the vehicle instrument panel. The knee bolster when in the stored position helps to maintain the door in the closed condition.

[0010] The foregoing and other features of the present invention will become apparent to one skilled in the art to which the present invention relates upon consideration of the following description of the invention with reference to the accompanying drawings, in which:

[0011] FIG. 1 is a schematic view, partially in section, of an apparatus in accordance with the present invention, including a knee bolster shown in a stored position and a deployment door shown in a closed condition;

[0012] FIG. 2 is a rear elevational view of the knee bolster and deployment door of FIG. 1;

[0013] FIG. 3 is a rear elevational view of a knee bolster and deployment door in accordance with a second embodiment of the invention;

[0014] FIG. 4 is a view similar to FIG. 1 of an apparatus in accordance with a third embodiment of the present invention; and

[0015] FIG. 5 is a rear elevational view of the knee bolster and deployment door of FIG. 5.

[0016] The present invention relates to an apparatus for helping to protect an occupant of a vehicle. In particular, the invention relates to a mechanism for securing, or maintaining in a closed condition, a door for a passenger side air bag. As representative of the present invention, FIG. 1 illustrates an apparatus 10.

[0017] The apparatus 10 includes a knee bolster 20. The knee bolster 20 is mounted in a lower portion 22 of a vehicle instrument panel indicated schematically at 24. The lower portion 22 of the instrument panel 24 is the portion of the instrument panel that a vehicle occupant's knees would contact were the occupant to slide forward from a seated position to contact the instrument panel.

[0018] The instrument panel 24, which is of a known construction, includes a metal or plastic substrate (not shown) which supports a trim pad or cover 26. The knee bolster 20 is configured as a continuation of the cover 26. The knee bolster 20 is preferably covered with or made from a resilient material for cushioning contact between the knee bolster and an occupant of the vehicle. The knee bolster 20 has a generally rectangular configuration as viewed from the rear of the vehicle (FIG. 2), including upper and lower edge portions 30 and 32 and inboard and outboard side portions 34 and 36.

[0019] An actuator indicated schematically at 40 is located in the instrument panel 24. The actuator 40 is a known mechanism for moving the knee bolster 20 rearward from a stored position shown in solid lines in FIG. 1 to a blocking position (shown in dashed lines in FIG. 1) spaced apart from the instrument panel 24. The actuator 40 preferably includes an inflatable device (not shown) in the form of an air bag, and an inflator (not shown) for inflating the inflatable device. Other types of actuators can, alternatively, be used.

[0020] The actuator 40 is electrically connected to an actuation circuit 42. The actuation circuit 42 includes a crash sensor, such as an inertia switch or an accelerometer, and a controller. Upon'detection of a crash condition requiring occupant protection, as sensed by the crash sensor, the controller controls the actuation circuit 42 so that the actuation circuit sends an electric signal to the actuator 40.

[0021] The apparatus 10 includes a passenger side air bag module 50. The module 50 includes a container 52 mounted in the instrument panel 24 at a location above the knee bolster 20 and the actuator 40. An inflator 54 is located inside the container 52 together with a folded air bag 56. The inflator 54 is electrically connected to the actuation circuit 42 by lead wires 58 for actuating the inflator when needed to help protect a front seat passenger of the vehicle.

[0022] The instrument panel 24 has a deployment opening 60 through which the air bag 56 is inflatable to help protect a passenger of the vehicle seated behind the module 50. The deployment opening 60 is closed by a cover or deployment door 62. The deployment door 62 has an upper edge portion 64, a lower edge portion 66, and inboard and outboard side portions 68 and 70. The upper edge portion 64 of the deployment door 62 is hingedly connected with the instrument panel 24 and supports the door for pivotal movement between a closed condition shown in solid lines in FIG. 1 and an open condition shown in dashed lines in FIG. 1. The inboard and outboard side portions 68 and 70 of the deployment door 62 are releasably connected with the instrument panel 24 by a suitable mechanism (not shown), such as tear seams or latches.

[0023] The lower edge portion 66 of the deployment door 62 is not directly connected with the instrument panel 24 by a tear seam or latch or such. Instead, the lower edge portion 66 of the deployment door 62 is at least partially covered by the knee bolster 20. Specifically, the upper edge portion 30 of the bolster 20 engages, or overlaps, the lower edge portion 66 of the deployment door 62. The upper edge portion 30 of the knee bolster 20 thereby prevents the lower edge portion 66 of the deployment door 62 from moving outward, that is, away from the instrument panel 24. As a result, the knee bolster 20, when in the stored position, secures or maintains the deployment door 62 in the closed condition.

[0024] Upon detection of a crash condition requiring occupant protection, as sensed by the crash sensor in the actuation circuit 42, the actuator 40 moves the knee bolster 20 from the stored position shown in solid lines in FIG. 1 to the blocking or open position shown in dashed lines in FIG. 1. The knee bolster 20, when in the blocking position shown dashed lines in FIG. 1, is positioned to contact the knees of a vehicle occupant and block further movement of the vehicle occupant in a forward direction in the vehicle. This blocking action can help to protect the vehicle occupant by preventing contact between the vehicle occupant and the instrument panel 24, and by preventing the vehicle occupant from “submarining” underneath the inflated air bag 56.

[0025] After the knee bolster 20 is thus moved, the inflator 54 for the air bag 56 is actuated. The inflator 54 produces inflation fluid under pressure which is directed into the air bag 56. The increased pressure in the air bag 56 causes the air bag to inflate outward against the deployment door 62. When the force of the inflating air bag 56 overcomes the resistance of the tear seams or latches or other mechanism that releasably secure the door 62, the door opens. The air bag 56 can then inflate into the vehicle passenger compartment.

[0026] Because the knee bolster 20 previously moved to a position spaced apart from the deployment door 62, the lower edge portion 66 of the deployment door is not restrained from movement when the air bag 56 inflates. As a result, less force is required to open the door 62 than would be required were the lower edge portion 66 of the door secured to the instrument panel 24 like the other edge portions of the door. Because less force is required to open the door 62, the pressure in the air bag 56 can be lower at the time the door opens and the air bag inflates into the passenger compartment. This can help reduce the amount of force applied to an out of position passenger of the vehicle.

[0027] FIG. 3 illustrates schematically a portion of an apparatus 100 in accordance with a second embodiment of the invention. The apparatus 100 includes a passenger side air bag module 102 mounted in a vehicle instrument panel 104. The air bag module 102 includes a deployment door 106 that is similar in construction and operation to the deployment door 62 (FIGS. 1-2). The deployment door 106 has a lower edge portion 108 that is not connected with the instrument panel 104 by a tear seam or otherwise.

[0028] The apparatus 100 includes a knee bolster 110. The knee bolster 110 has a U-shaped configuration including inboard and outboard side portions 112 and 114 connected by a base portion 116. The side portions 112 and 114 have upper edge portions 118 and 120, respectively. A glove box 122 is located within the U-shaped configuration of the bolster 110.

[0029] The upper edge portions 118 and 120 of the knee bolster 110 engage, or overlap, the lower edge portion 108 of the deployment door 106. This overlapping engagement prevents the lower edge portion 108 of the deployment door 106 from moving outward, that is, away from the instrument panel 104. As a result, the knee bolster 110 maintains the deployment door 106 in a closed condition when the knee bolster is in the stored position.

[0030] When the knee bolster 110 is moved from the stored position to a position spaced apart from the instrument panel 104, the upper edge portions 118 and 120 of the knee bolster move away from the lower edge portion 108 of the deployment door 106. The lower edge portion 108 of the deployment door 106 is released and does not offer any resistance to opening by the inflating air bag of the module 102. As a result, less force is required to open the door 106 than would be required were the lower edge portion 108 of the door secured to the instrument panel 104.

[0031] FIGS. 4 and 5 illustrate an apparatus 10ain accordance with a third embodiment of the invention. The apparatus 10a is similar to the apparatus 10 (FIGS. 1-2) and parts that are the same are given the same reference numerals with the suffix “a” added for clarity.

[0032] The apparatus 10aincludes a deployment door 62aand a knee bolster 20a. The deployment door 62ahas an upper edge portion 64athat is hingedly connected with the instrument panel 24a. The deployment door 62aalso has a lower edge portion 66aand inboard and outboard side portions 68aand 70a.

[0033] The knee bolster 20ahas an upper edge portion 30a, a lower edge portion 32aand inboard and outboard side portions 34aand 36a. The deployment door 62ais molded as one piece with the resilient material of the knee bolster 20a. The upper edge portion 30aof the knee bolster 20ais connected with the lower edge portion 66aof the deployment door 62aby a common tear seam 67. As a result, the knee bolster 20ais in engagement with the door 62aalong the tear seam 67.

[0034] When the knee bolster 20ais actuated, it moves away from the instrument panel 24a,rupturing the tear seam 67 between the upper edge portion 30aof the knee bolster and the lower edge portion 66aof the deployment door 62a. As a result, the lower edge portion 66aof the deployment door 62ais not restrained from movement and thus does not offer any resistance to opening. Less force is therefore required to open the deployment door 62athan would be required were the lower edge portion 66aof the door secured to the instrument panel 24alike the other edge portions of the door.

[0035] From the above description of the invention, those skilled in the art will perceive improvements, changes and modifications in the invention. Such improvements, changes and modifications within the skill of the art are intended to be covered by the appended claims.