Seat assembly having a pivot restraint mechanism that limits seat back movement

A seat assembly having a seat bottom, a seat back, and at least one belt. The belt may have a first end that may be coupled to a seat bottom frame and a second end that may be coupled to a seat back frame. The belt may limit pivotal movement of the seat back away from the seat bottom.

TECHNICAL FIELD

This disclosure relates to a seat assembly having a pivot restraint mechanism that limits pivotal movement of a seat back.

BACKGROUND

A seat belt system for a vehicle seat is disclosed in U.S. Pat. No. 6,655,744.

SUMMARY

In at least one embodiment, a seat assembly is provided. The seat assembly may include a seat bottom, a seat back, and a belt. The seat bottom may have a seat bottom frame. The seat back may be pivotal about an axis with respect to the seat bottom. The seat back may have a seat back frame. The belt may have a first end and a second end. The first end may be coupled to the seat bottom frame. The second end may be coupled to the seat back frame. The belt may limit pivotal movement of the seat back about the axis and a rotational direction that extends away from the seat bottom.

In at least one embodiment, a seat assembly is provided. The seat assembly may include a seat bottom, a seat back, and a first belt. The seat bottom may include a seat bottom frame and a seat bottom trim cover. The seat bottom frame may have first and second lateral seat bottom side members that may extend along opposing lateral sides of the seat bottom. The seat bottom trim cover may cover the seat bottom frame. The seat back may be pivotally disposed on the seat bottom. The seat back may include a seat back frame and a seat back trim cover. The seat back frame may have first and second lateral seat back side members that extend along opposing lateral sides of the seat back. The seat back trim cover may cover the seat back frame. The first belt may extend from the seat bottom to the seat back. The first belt may have a first end and a second end that may be disposed opposite the first end. The first end may be coupled to the first lateral seat bottom side member. The second end may be coupled to the first lateral seat back side member. The first belt may be disposed between the seat bottom trim cover and an outboard side of the first lateral seat bottom side member that faces away from the second lateral seat bottom side member. The first belt may also be disposed between the first seat back trim cover and an outboard side of the first lateral seat back side member that faces away from the second lateral seat back side member.

DETAILED DESCRIPTION

Referring toFIG. 1, an example of a seat assembly10is shown. The seat assembly10may be configured for use in a motor vehicle, such as a car or truck. The seat assembly10may include a seat bottom12, a seat back14, and at least one pivot restraint mechanism16.

Referring toFIG. 3, the seat bottom12may be configured to support a seat occupant18. The seat bottom12may be mounted to a support surface, such as a vehicle floor. For reference purposes, the side of the seat bottom12or side of components of the seat bottom12that faces in a forward direction or toward the front of the seat assembly10(e.g., to the left from the perspective shown inFIG. 3) may be referred to as a front side20. A rear side22may be disposed opposite the front side20and may face to the right from the perspective shown inFIG. 3. A top side24may face toward a seat occupant18. A bottom side26may be disposed opposite the top side24. As is best shown inFIG. 1, opposing lateral sides28or left and right sides or sides may extend between the front side20and the rear side22and that may extend between the top side24and the bottom side26.

As is best shown with reference toFIGS. 1 and 2, the seat bottom12may include seat bottom trim cover30, a seat bottom cushion32, and a seat bottom frame34.

Referring toFIG. 1, seat bottom trim cover30may be disposed over or upon the seat bottom cushion32and may form or provide at least a portion of a visible exterior surface of the seat bottom12. In addition, the seat bottom trim cover30may cover or conceal at least a portion of the seat bottom frame34. A seat occupant18may be disposed on the seat bottom trim cover30when in a seated position. The seat bottom trim cover30may include a plurality of trim panels that may be assembled in any suitable manner, such as by stitching. In addition, the seat bottom trim cover30may be made of any suitable material or materials, such as fabric, leather, vinyl, carpet, or combinations thereof.

The seat bottom cushion32may be disposed between the seat bottom trim cover30and the seat bottom frame34. For example, the seat bottom cushion32may be disposed on and may be supported by the seat bottom frame34and may be at least partially concealed by the seat bottom trim cover30. The seat bottom cushion32may be made of any suitable material, such as foam.

Referring toFIG. 2, the seat bottom frame34may provide a load bearing structure for the seat bottom12. In at least one configuration, the seat bottom frame34may include a first lateral seat bottom side member40, a second lateral seat bottom side member42, a front cross member44, and a rear cross member46.

The first lateral seat bottom side member40and the second lateral seat bottom side member42may be disposed along opposing lateral sides or left and right sides of the seat bottom frame34. The first lateral seat bottom side member40and the second lateral seat bottom side member42may be spaced apart from each other and may extend generally parallel to each other. The first lateral seat bottom side member40and the second lateral seat bottom side member42may each include a rear end that may be disposed proximate the seat back14and a front end that may be disposed opposite the rear end. The first lateral seat bottom side member40and the second lateral seat bottom side member42may be integrally formed with the front cross member44, the rear cross member46, or both. Alternatively, the first lateral seat bottom side member40and the second lateral seat bottom side member42may be provided as separate components from the front cross member44and the rear cross member46. A lateral seat bottom side member that is not integrally formed with a cross member may be attached to a cross member in any suitable manner, such as by welding or with fasteners.

The front cross member44may be generally disposed at the front of the seat bottom frame34and underneath the thigh region of the seat occupant18. The front cross member44may extend from the front end of the first lateral seat bottom side member40to the front end of the second lateral seat bottom side member42. The front cross member44may be disposed substantially perpendicular to the first lateral seat bottom side member40and the second lateral seat bottom side member42in one or more configurations.

The rear cross member46may be disposed at or near the rear of the seat bottom frame34and below the seat back14. In addition, the rear cross member46may be disposed substantially parallel to the front cross member44in one or more configurations. The rear cross member46may be fixedly attached to the first lateral seat bottom side member40to the second lateral seat bottom side member42. For example, the rear cross member46may extend from the rear end of the first lateral seat bottom side member40to the rear end of the second lateral seat bottom side member42.

Referring toFIGS. 1-3, the seat back14may be configured to support the back of a seat occupant18. The seat back14may be pivotal about an axis50with respect to the seat bottom12. For example, a pair of recliner mechanisms52may pivotally connect the seat back14to the seat bottom12as is best shown inFIGS. 2 and 3. As is best shown inFIG. 2, a synchronization rod54may extend along the axis50between the recliner mechanisms52to synchronize operation of the recliner mechanisms52in a manner known by those skilled in the art.

Referring toFIG. 1, for reference purposes the side of the seat back14or side of components of the seat back14that face in a forward direction or toward the front of the seat assembly10or toward a seat occupant18may be referred to at a front side60. A back side62may be disposed opposite the front side60. An upper side64may be disposed adjacent to and below a headrest that is located at the top of the seat back14. The lower side66may be disposed opposite the upper side64. The left and right sides or sides that may extend between the front side60and the back side62and that may extend between the upper side64and the lower side66may be referred to as lateral sides68.

As is best shown with reference toFIGS. 1 and 2, the seat back14may include seat back trim cover70, a seat back cushion72, a seat back frame74, and a headrest76or head restraint.

Referring toFIG. 1, the seat back trim cover70may be disposed over or upon the seat back cushion72and may form or provide at least a portion of a visible exterior surface of the seat back14. In addition, the seat back trim cover70may cover or conceal at least a portion of the seat back frame74. A seat occupant18may be disposed on the seat back trim cover70when in a seated position. The seat back trim cover70may include a plurality of trim panels that may be assembled in any suitable manner, such as by stitching. In addition, the seat back trim cover70may be made of any suitable material or materials, such as fabric, leather, vinyl, carpet, or combinations thereof.

The seat back cushion72may be disposed between the seat back trim cover70and the seat back frame74. For example, the seat back cushion72may be disposed on and may be supported by the seat back frame74and may be at least partially concealed by the seat back trim cover70. The seat back cushion72may be made of any suitable material, such as foam.

The seat back cushion72may be disposed between the seat back trim cover70and the seat back frame74. For example, the seat back cushion72may be disposed on a front side of the seat back14with respect to the seat back frame74and may be at least partially concealed by the seat back trim cover70. The seat back cushion72may be made of any suitable material, such as foam.

Referring toFIG. 2, the seat back frame74may provide a load bearing structure for the seat back14. In at least one configuration, the seat back frame74may include a first lateral seat back side member80, a second lateral seat back side member82, an upper cross member84, and a lower cross member86.

The first lateral seat back side member80and the second lateral seat back side member82may be spaced apart from each other and may generally extend away from the seat bottom12along opposing lateral sides of the seat back14. The first lateral seat back side member80and the second lateral seat back side member82may be disposed substantially parallel to each other. In addition, the first lateral seat back side member80and the second lateral seat back side member82may extend from the lower cross member86to the upper cross member84. The first lateral seat back side member80and the second lateral seat back side member82may be integrally formed with the upper cross member84, the lower cross member86, or both. Alternatively, the first lateral seat back side member80and the second lateral seat back side member82may be provided as separate components from the upper cross member84and the lower cross member86. A lateral seat back side member that is not integrally formed with a cross member may be attached to a cross member in any suitable manner, such as by welding or with fasteners.

The upper cross member84may be disposed proximate the upper side64of the seat back14. The upper cross member84may extend from the first lateral seat back side member80to the second lateral seat back side member82and may extend in a generally horizontal direction.

The lower cross member86may be disposed proximate the lower side66of the seat back14and may be disposed above the seat bottom12. The lower cross member86may be disposed opposite the upper cross member84and extend from the first lateral seat back side member80to the second lateral seat back side member82. As such, the lower cross member86may extend in a generally horizontal direction.

Referring toFIGS. 1-3, at least one pivot restraint mechanism16may be provided with the seat assembly10. The pivot restraint mechanism16may limit pivotal movement or rotation of the seat back14in a rearward direction about the axis50with respect to the seat bottom12as will be discussed in more detail below. In the configuration shown, two pivot restraint mechanisms16are provided and are located along opposing lateral sides of the seat assembly10. In at least one configuration, the pivot restraint mechanism16may include a pretensioner90and a belt92.

The pretensioner90may facilitate coupling of the belt92to either the seat bottom frame34or the seat back frame74. For example, one end of the belt92may be coupled to a portion of the pretensioner90, such as a rotatable spool, and the pretensioner90may be coupled to either the seat bottom frame34or the seat back frame74. In the configuration shown inFIGS. 1-3, the pretensioner90is mounted to the seat bottom frame34. In such a configuration, a pretensioner90may be mounted on the first lateral seat bottom side member40, the second lateral seat bottom side member42, or both. In the configuration shown inFIG. 4, the pretensioner90is mounted on the seat back frame74. In such a configuration, a pretensioner90may be mounted on the first lateral seat back side member80, the second lateral seat back side member82, or both.

The pretensioner90may be operative to retract the belt92and/or lock to inhibit unwinding of the belt92from the pretensioner90. For example, the pretensioner90may operate to tighten the belt92and remove slack, such as by winding the belt92onto a spool. The pretensioner90may be of any suitable type. For instance, the pretensioner90may be the same type that commercially available for use with occupant seat belts. In addition, the pretensioner90may be an electric pretensioner or a pyrotechnic pretensioner that may employ a pyrotechnic charge or explosively expanding gas to drive a piston that may retract the belt92. The pretensioner90may be triggered by one or more sensors on the vehicle as is known by those skilled in the art.

The belt92may extend from the pretensioner90and may extend between the seat bottom12and the seat back14. The belt92may have any suitable configuration. For example, the belt92may be made of the same material and weave as a seat belt. However, the belt92may not restrain a seat occupant18and therefore may be spaced apart from and may not engage the seat occupant18. In at least one configuration, the belt92may have a first end100and a second end102.

The first end100may be an end of the belt92that is coupled to the seat bottom frame34. For example, the first end100of the belt92of one pivot restraint mechanism16may be coupled to the first lateral seat bottom side member40while the first end100of the belt92of another pivot restraint mechanism16may be coupled to the second lateral seat bottom side member42. In the configuration shown inFIGS. 1-3, the first end100of each belt92may be coupled to the seat bottom frame34via a corresponding pretensioner90. In the configuration shown inFIG. 4, the first end100may be a free end that is disposed opposite the pretensioner90and may have a mounting feature104, such as a buckle or mounting plate, that is coupled to a lateral seat bottom side member via a fastener, such as a mating buckle portion or bolt. The first end100of the belt92may be coupled to the seat bottom frame34below the axis50and forward of a seat bottom center line110. The seat bottom center line110may be disposed midway between the front side20of the seat bottom12and the rear side22of the seat bottom12. The seat bottom center line110may be disposed in a plane that may extend in a generally vertical direction.

The second end102may be disposed opposite the first end100and may be coupled to the seat back frame74. For example, the second end102of the belt92of one pivot restraint mechanism16may be coupled to the first lateral seat back side member80while the second end102of the belt92of another pivot restraint mechanism16may be coupled to the second lateral seat back side member82. In the configuration shown inFIGS. 1-3, the second end102is a free end that is disposed opposite the pretensioner90and may have a mounting feature104. In the configuration shown inFIG. 4, the first end100of each belt92may be coupled to the seat back frame74via a corresponding pretensioner90. The second end102of the belt92may be coupled to the seat back frame74above the axis50and below the upper side64of the seat back14. For example, the second end102of the belt92may be coupled to the seat back frame74above the axis50and below a seat back center line120. The seat back center line120may be disposed midway between the upper side64and the lower side66of the of the seat back14. The seat back center line120may be disposed in a plane that may extend in a generally horizontal direction.

The belts92may be disposed completely inside the seat assembly10or primarily inside of the seat assembly10. For example, the seat bottom trim cover30and the seat back trim cover70may cooperate to completely cover or conceal the belt92.

Referring toFIG. 7, a sleeve130may be provided with the seat bottom trim cover30and/or the seat back trim cover70to receive and further conceal the belt92. The sleeve130may be provided where the belt92passes through the seat bottom trim cover30and the seat back trim cover70. The sleeve130may extend from the seat bottom trim cover30to the seat back trim cover70and may conceal the belt92when the seat back14is reclined away from the seat bottom12to an extent where the seat back trim cover70disengages the seat bottom trim cover30where the belt92exits the seat bottom trim cover30and the seat back trim cover70. The sleeve130may stretch or expand to conceal the belt92throughout the full range of reclining motion of the seat back14. For example, the sleeve130may be a flexible material, such as a fabric or film, that may accommodate movement of the belt92or may be a rigid or semi rigid material, such as a polymeric material.

Referring toFIGS. 1-3, the belts92may be disposed outboard of the lateral seat bottom side members. For example, one belt92may be disposed between the seat bottom trim cover30and an outboard side140of the first lateral seat bottom side member40. The outboard side140of the first lateral seat bottom side member40may face away from the center of the seat bottom12and away from the second lateral seat bottom side member42. Another belt92may be disposed between the seat bottom trim cover30and an outboard side140of the second lateral seat bottom side member42. The outboard side140of the second lateral seat bottom side member42may face away from the center of the seat bottom12and away from the first lateral seat bottom side member40.

In a similar manner, the belts92may be disposed outboard of the lateral seat back side members. For example, one belt92may be disposed between the seat back trim cover70and an outboard side142of the first lateral seat back side member80. The outboard side140of the first lateral seat back side member80may face away from the center of the seat back14and away from the second lateral seat back side member82. Another belt92may be disposed between the seat back trim cover70and an outboard side142of the second lateral seat back side member82. The outboard side142of the second lateral seat back side member82may face away from the center of the seat back14and away from the first lateral seat back side member80.

The belts92may be located in various positions between the seat bottom frame34and the seat bottom trim cover30and between the seat back frame74and the seat back trim cover70. For instance, the belts92may be primarily or completely disposed outboard of the side members of the seat bottom frame34and/or the seat back frame74.

Referring toFIG. 6, the belts may extend along the seat bottom frame34and the seat back frame74. For instance, a belt92may be located under the seat bottom trim cover30and may be disposed proximate and may engage the first lateral seat bottom side member40and/or the second lateral seat bottom side member42. Similarly, a belt92may be located under the seat back trim cover70and may be disposed proximate and may engage the first lateral seat back side member80and/or the second lateral seat back side member82. The belt92may engage the seat bottom trim cover30and the seat back trim cover70. In such a configuration, the seat bottom trim cover30and/or the seat back trim cover70may include additional material or padding on a surface that faces the belt92to help mask the location of the belt92to provide an improved aesthetic appearance.

Referring toFIG. 3, the belts92may also extend along a lateral side of the seat bottom cushion32and the seat back cushion72. For instance, a belt92may be disposed under the seat bottom trim cover30and may be positioned between the seat bottom trim cover30and a lateral side of the seat bottom cushion32and may be disposed under the seat back trim cover70and may be positioned between the seat back trim cover70and a lateral side of the seat back cushion72.

Referring toFIG. 5, the belts92may also extend through the seat bottom cushion32and/or the seat back cushion72. For instance, a belt92may be disposed under the seat bottom trim cover30and may extend through a slit150in the seat bottom cushion32and may be disposed under the seat back trim cover70and may extend through a slit152in the seat back cushion72.

The slits150,152may be sized to provide adequate space for the belt92to move when the seat back14is folded over the seat bottom12or fully reclined away from the seat bottom12. In addition, it is contemplated that the sleeve130may extend into one or both slits150,152to prevent or inhibit the belt92from cutting or tearing the seat bottom cushion32and/or the seat back cushion72. It is also contemplated that separate sleeves may be provided in the seat bottom cushion32and the seat back cushion72such that the sleeves do not extend between the seat bottom trim cover30and the seat back trim cover70.

The pivot restraint mechanisms16may limit pivotal movement of the seat back14away from the seat bottom12. For instance, the pivot restraint mechanisms16may limit rotation of the seat back14about the axis50and away from the seat bottom12in response to a rear vehicle impact event. A seat occupant18may exert increased rearward force on the seat back14in response to a rear vehicle impact event. The pivot restraint mechanisms16may supplement the counteracting force exerted by the recliner mechanisms52to reduce rearward rotation of the seat back14.

One or more sensors may be provided with the vehicle that may detect a rear impact event in a manner known by those skilled in the art. The pretensioners90may be activated in response to the detection of a rear vehicle impact event to retract corresponding belts92, thereby providing increased tensile force on the belts92. The increased tensile force may help limit or prevent rotation of the seat back14away from the seat bottom12. Angular rotation of the seat back14about the axis50may decrease as the tensile force exerted by the pretensioners90increases. As an example, a seat assembly may be configured to allow rearward angular rotation of approximately 32° when not equipped with pivot restraint mechanisms. Equipping the same seat assembly with pivot restraint mechanisms16may reduce rearward angular rotation of the seat back14. Providing a tensile force of 2500 N with the pivot restraint mechanisms may limit rearward angular rotation to approximately 24°, a tensile force of 4500 N may limit angular rotation to approximately 21°, and a tensile force of 8500 N may limit angular rotation to approximately 16°. As such, the amount of force that is exerted by the pretensioners90may be set to limit the rearward rotation of the seat back14about the axis50.

The pivot restraint mechanisms16may also reduce peak moment forces exerted on the recliner mechanisms52. The moment forces on the recliner mechanisms52may initially be negative (e.g., the pretensioners90may exert force that may bias seat back forward) when the pretensioners90are activated, which may reduce the peak moment forces exerted on the recliner mechanisms52as compared to a seat assembly that is not provided with pivot restraint mechanisms, which may help improve the capability of the seat assembly10to withstand impact forces.