Patent Publication Number: US-2012025582-A1

Title: Seat assembly having an adjustable head restraint assembly

Description:
BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a seat assembly having an adjustable head restraint assembly. 
     SUMMARY OF THE INVENTION 
     In at least one embodiment, a seat assembly is provided. The seat assembly has a seat back and a head restraint assembly. The head restraint assembly includes a headrest for supporting the head of a seat occupant, a support post, and a drive assembly. The support post extends between the seat back and the headrest and has an engagement area. The drive assembly has a rotatable element that engages the engagement area. The drive assembly actuates the headrest away from the seat back when the rotatable element is rotated in a first direction and actuates the headrest toward the seat back when the rotatable element is rotated in a second direction that is opposite the first direction. 
     In at least one other embodiment, a seat assembly is provided. The seat assembly has a seat back and a head restraint assembly disposed on the seat back. The head restraint assembly includes a support post, a headrest, an armature, and a drive assembly. The support post extends from the seat back and has an engagement area. The headrest is disposed on a support post and is spaced apart from the engagement area. The armature is disposed in the seat back and has an upright member that receives the support post. The upright member has an aperture disposed proximate the engagement area. The drive assembly at least partially extends through the aperture to engage the engagement area. The drive assembly actuates the headrest toward and away from the seat back. 
     In at least one additional embodiment, a seat assembly is provided that has a seat back and a head restraint assembly. The head restraint assembly has a support post, a headrest, and a drive assembly. The support post is disposed on the seat back and has an engagement area. The headrest is disposed on the support post. The drive assembly has an output unit, an intermediate unit, and an actuator unit. The output unit operatively engages the engagement area. The intermediate unit rotates to actuate the output unit. The actuator unit rotates the intermediate unit. The headrest moves in a first direction when the intermediate unit rotates in a first rotational direction and moves in a second direction disposed opposite the first direction when the intermediate unit rotates in a second rotational direction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a seat assembly. 
         FIG. 2  is a fragmentary perspective view of a portion of a seat back of the seat assembly including an exemplary embodiment of an adjustable head restraint assembly. 
         FIG. 3  is an exploded perspective view of the adjustable head restraint assembly shown in  FIG. 2 . 
         FIG. 4  is a magnified side view of a portion of a support post of the adjustable head restraint assembly. 
         FIG. 5  is a fragmentary side view of a portion of another embodiment of an adjustable head restraint assembly. 
     
    
    
     DETAILED DESCRIPTION 
     Detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention that may be embodied in various and alternative forms. The figures are not necessarily to scale, some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a representative basis for the claims and/or as a representative basis for teaching one skilled in the art to variously employ the present invention. 
     Referring to  FIG. 1 , an exemplary seat assembly  10  is shown. The seat assembly  10  may be configured for use in a vehicle, such as a motor vehicle like a car or truck. 
     The seat assembly  10  may include a seat bottom  12  and a seat back  14 . The seat bottom  12  may be configured to be mounted on a support surface, such as a floor pan of a vehicle. The seat back  14  may be pivotally disposed on the seat bottom  12  and may include a head restraint assembly  16 . 
     Referring to  FIG. 2 , an upper portion of the seat back  14  and the head restraint assembly  16  are shown in more detail. The seat back  14  may include a structural frame  20 . The frame  20  may include first and second side members  22 ,  24  and a cross member  26  that extends between the first and second side members  22 ,  24 . Alternatively, the first and/or second side members  22 ,  24  may be integrally formed with the cross member  26  in one or more embodiments of the present invention. The cross member  26  may include one or more openings  28  that receive a portion of the head restraint assembly  16  as will be discussed in more detail below. 
     Referring to  FIGS. 2 and 3 , the head restraint assembly  16  is shown in more detail. The head restraint assembly  16  may be configured to move with respect to the seat back  14 . In addition, the head restraint assembly  16  may be used with a seat assembly having an active head restraint system in which a head restraint moves to support the head of a seat occupant in response to a vehicle impact event. An example of such an active head restraint system is described in U.S. Pat. Nos. 6,789,845 and 7,455,357, assigned to the assignee of the present invention and hereby incorporated by reference in its entirety. In at least one embodiment, the head restraint assembly  16  may include a headrest  30 , a support post  32 , a guide sleeve  34 , an armature  36 , and a drive assembly  38 . 
     The headrest  30  may be configured to support the head of a seat occupant. The headrest  30  may be disposed above or at the top of the seat back  14  and may be mounted to and disposed around the support post  32 . For clarity, the headrest  30  is shown in phantom in  FIG. 2  and is not shown in  FIG. 3 . 
     The support post  32  may extend between the headrest  30  and the seat back  14 . The support post  32  may include one or more upright portions  40  and a headrest mounting portion  42 . The upright portions  40  and headrest mounting portion  42  may be provided as a one-piece component and may be made of any suitable material, such as a metal or metal alloy. The upright portions  40  may be generally linear in one or more embodiments. 
     An engagement area  44  may be provided along at least a portion the support post  32 . For example, the engagement area  44  may be provided on at least one upright portion  40 . The engagement area  44  may be disposed in any suitable side and location on the upright portion  40 . For example, the engagement area  44  may extend from a free end of the upright portion  40  along a portion of the upright portion  40  such that the engagement portion  44  is not visible when the support post  32  is installed in the seat back  14 . In an embodiment in which the headrest  30  moves with respect to the support post  32 , the engagement area  44  may be provided on the headrest mounting portion  42 . 
     The engagement area  44  may have any suitable configuration. For example, the engagement area  44  may be configured with a surface treatment or features that help provide sufficient friction to facilitate actuation of the support post  32 . For instance, the engagement area  44  may be provided with protrusions, indentations, a rough or textured surface, or combinations thereof. In at least one embodiment, the engagement area  44  includes a set of teeth  46 . As is best shown in  FIG. 4 , the set of teeth  46  may be disposed on a surface  48 . The surface  48  may have any suitable configuration and may be generally flat or planar. In addition, each member of the set of teeth  46  may extend partially across the surface  48 . As such, the teeth may be spaced apart or set back from lateral edges of the surface  48 , such as where the surface  48  intersects a curved surface of the support post  32 , which may help inhibit binding during installation and/or operation. 
     The headrest mounting portion  42  may be disposed in the headrest  30 . The headrest mounting portion  42  may extend from at least one upright portions  40  and may be configured to help receive and/or distribute force exerted by a head of a seat occupant. The headrest mounting portion  42  may extend between and connect multiple upright portions  40  in embodiments of a support post  32  having more than one upright portion  40 . In addition, the headrest mounting portion  42  may extend forward or at an angle from the upright portions  40 . 
     The guide sleeve  34  may receive a portion of the support post  32 . In addition, the guide sleeve  34  may be disposed in and/or mounted to the frame  20  of the seat back  14 . For example, the guide sleeve  34  may generally extend from the top of the seat back  14  into the seat back  14  and into an opening  28  in the cross member  26 . In an embodiment having an active head restraint system, the guide sleeve  34  may move with respect to the frame  20  and opening  28 . 
     The armature  36  may be disposed in the seat back  14 . The armature  36  may include a lateral member  50  and one or more upright members  52 . 
     The lateral member  50  may be configured to be mounted on the seat back  14 . For example, the lateral member  50  may have first and second ends  54 ,  56  that may be fixedly or pivotally associated with the seat back frame  20 . In the embodiment shown in  FIGS. 2 and 3 , the first and second ends  54 ,  56  are received by mounting brackets or links  58  that may be disposed on the frame  20 . The lateral member  50  may pivot with respect to the links  58  or the links  58  may pivot with respect to the frame  20  to permit the head restraint assembly  16  to move upward and/or forward in one or more embodiments. Alternatively, links  58  may be deleted and the lateral member  50  may be mounted directly to the frame  20  or another suitable component. The lateral member  50  may be configured as a hollow tube and may include one or more openings  60  through which the support post  32  may extend. 
     One or more upright members  52  may extend from the lateral member  50 . In the embodiment shown in  FIGS. 2 and 3 , two upright members  52  are provided that are spaced apart and extend generally parallel to each other. Each upright member  52  may be configured as a hollow tube and may engage the guide sleeve  34 . For example, an upright member  52  may receive a guide sleeve  34  or vice versa in one or more embodiments. As is best shown in  FIG. 3 , the upright member  52  may include an aperture  64  that permits access to the support post  32  and the engagement area  44 . The aperture  64  may have any suitable configuration and may be disposed in any suitable location. 
     A guide member  66  may be provided in the lateral and/or upright members  50 ,  52  to help support and guide movement of the support post  32  within the armature  36 . Moreover, the guide member  66  may help inhibit rattling of the support post  32 . The guide member  66  may have any suitable configuration and may be configured as a ring or bushing. In the embodiment shown, the guide member  66  extends through the opening in the lateral member  50  and into the upright member  52  without covering the aperture  64 . The guide member  66  may include a flange  68  that may engage the lateral member  50  to help position the guide member  66 . 
     The drive assembly  38  may provide force to actuate or initiate movement of the head restraint assembly  16 . The drive assembly  38  may actuate at least a portion of the head restraint assembly  16  in multiple directions and between multiple positions. For example, the drive assembly  38  may actuate the head restraint assembly  16  generally toward or away from the seat back  14 . Moreover, the drive assembly  38  may actuate the headrest  30  or head restraint assembly  16  between a fully advanced position and a fully retracted position and hold it at one or more positions therebetween. 
     The drive assembly  38  may have any suitable configuration. As is best shown in  FIG. 3 , the drive assembly  38  may include an actuator unit  70 , an intermediate unit  72 , and output unit  74 , and a housing  76 . The present invention also contemplates embodiments that may omit one or more of these units, such as the intermediate unit  72  and/or output unit  74 , or the housing  76 . 
     The drive assembly  38  may be disposed in any suitable location. In the embodiment shown in  FIG. 2 , the drive assembly  38  is located below the cross member  26  of the seat back frame  20  and generally above the lateral member  50  of the armature  36 . Alternatively, the drive assembly  38  may be reconfigured to be located generally below the lateral member  50 . In such an embodiment, the aperture  64  in the upright member  52  of the armature  36  may be eliminated. In at least one another embodiment, the drive assembly  38  may be mounted to the frame  20  or located in the cross member  26 . In addition, the drive assembly  38  may be disposed in the headrest  30  in one or more embodiments and configured to move with respect to the support posts  32 . 
     The actuator unit  70  may be configured to exert a biasing force. The actuator unit  70  may have any suitable configuration. For example, the actuator unit  70  may include an electrical machine  80 , such as a motor or solenoid. The electrical machine  80  may include an output element  82 , such as an output shaft that may be adapted to drive or exert force upon the intermediate unit  72 . For instance, the output element  82  may be provided with an engagement feature, such as a gear like a worm gear, that engages the intermediate unit  72 . 
     The intermediate unit  72 , if provided, may transmit force from the actuator unit  70  to the output unit  74 . The intermediate unit  72  may be provided with a unitary construction or as an assembly of components. The intermediate unit  72  may include a first portion  90  and a second portion  92 . The first and second portions  90 ,  92  may be disposed along and/or rotate about a common axis  94 . The first portion  90  may be adapted to engage the output element  82  of the actuator unit  70 . For instance, the first portion  90  may be configured as a gear such as a helical gear. The second portion  92 , which may have a smaller diameter than the first portion  90 , may also be configured as gear like as a worm and may be adapted to engage the output unit  74 . As such, the intermediate unit  72  may be configured to provide a predetermined amount of gear reduction that may facilitate the use of smaller or less expensive electrical machine. 
     The output unit  74 , if provided, may transmit force from the intermediate unit  72  to actuate the support post  32 . The output unit  74  may be provided with a unitary construction or as an assembly of components. The output unit  74  may have any suitable configuration. For instance, the output unit  74  may generally be configured as a shaft and may include an input element  100  and at least one output element  102 . The input element  100  may be adapted to engage the second portion  92  of the intermediate unit  72 . 
     The input element  100  may have any suitable configuration. For instance, the input element  100  may be configured as a gear such as a helical gear. The output element  102  may be adapted to engage the engagement area  44  of the support post  32 . The output element  102  may have any suitable configuration that is compatible with the engagement area  44 . For example, the output element  102  may be configured with a surface treatment or features that help provide sufficient friction to facilitate actuation of the support post  32 . For instance, the output element  102  may be provided with protrusions, indentations, a rough or textured surface, or combinations thereof. In at least one embodiment, the output element  102  may be configured as a gear such as a spur gear that engages the set of teeth  46  on the support post  32 . The input element  100  may be spaced apart from the output element  102 . 
     The housing  76  may facilitate mounting of the drive assembly  38  and various components. As is best shown in  FIG. 2 , the housing  76  may be mounted on the armature  36 . For example, the housing  76  may be mounted to the lateral member  50  and or an upright member  52 . Alternatively, one or more of these mounting positions may be deleted or changed. For instance, the housing  76  could be mounted to one or more different components, such as the frame  20  in one or more embodiments. 
     The housing  76  may have any suitable configuration. In the embodiment shown, the housing  76  includes a first portion  110  and a second portion  112 . The first and second portions  110 ,  112  may have similar configurations. The first and second portions  110 ,  112  may cooperate to facilitate mounting of the housing  76 . For instance, the first and second portions  110 ,  112  may be disposed around and fixedly positioned relative to the lateral member  50  and/or upright members  52 . Of course, the present invention also contemplates embodiments in which the housing  76  has a different number of attachment points or locations of attachment. For example, the housing  76 , if provided, may be coupled to the frame  20  or disposed in the headrest  30  in other embodiments as previously discussed. 
     The first and second portions  110 ,  112  may also receive various components of the actuator unit  70 , intermediate unit  72 , and/or output unit  74 . For instance, the actuator unit  70  and intermediate unit  72  may be mounted to and/or at least partially received by the first and second portion  110 ,  112 . The first and second portions  110 ,  112  may also cooperate to define a channel  114  that receives the output unit  74 . As such, the first and second portions  110 ,  112  may support the output unit  74  in the channel  114  and permit the output unit  74  to rotate. The first and second portions  110 ,  112  may be made of any suitable material, such as a polymeric material and may be assembled in any suitable manner, such as by fasteners, mating features, a bonding agent, or vibration welding. 
     Operation of the embodiment shown in  FIGS. 2 and 3  may be described as follows. An input signal may be provided to control operation of the electrical machine  80  in any suitable manner, such as by a switch that may be disposed on the seat assembly  10  or a controller. The input signal may be indicative of a command to advance or retract the head restraint assembly  16 . Advancing the head restraint assembly  16  may move the headrest  30  away from the seat back  14  or in a first manner while retracting the head restraint assembly  16  may move the headrest  30  toward the seat back  14  or in a second manner. The electrical machine  80  may move or rotate in a first direction when the input signal is indicative of a command to advance and may move or rotate in a second direction that may be opposite the first direction when the input signal is indicative of a command to retract. 
     Operation of the electrical machine  80  may drive output element  82  which may then drive or rotate the intermediate unit  72 . The intermediate unit  72  may then drive or rotate the output unit  74  which in turn actuates the support post  32 . The interface between the actuator unit  70  and intermediate unit  72  and/or the interface between the intermediate unit  72  and output unit  74  may provide a resistive force or act as a locking mechanism that inhibits movement of the support post  32  when the electrical machine  80  is not operated. For instance, an interface having one or more gears may help inhibit movement in the absence of a sufficient actuation force. As such, the headrest  30  may be maintained in a desired position when the input signal is not indicative of an actuation command or during a vehicle impact event. 
     The actuation distance of the head restraint assembly  16  may be based on the configuration of the support post  32  and its engagement area  44 . A longer engagement area  44  may provide a greater distance of travel. In at least one embodiment, the distance of travel may be around 50 mm, although a greater or lesser distance of travel. 
     Referring to  FIG. 5 , an example of an alternate embodiment of a drive assembly  38 ′ is shown. In this embodiment, an electrical machine  80 ′ may drive one or more output shafts or output elements. Although  FIG. 5  shows multiple output shafts as well as a support post  32  having multiple upright portions  40 , the present invention also contemplates embodiments having a single upright portion  40  and a single output shaft and associated components. 
     In  FIG. 5 , first and second output shafts  120 ,  122  are shown. The first and second output shafts  120 ,  122  may be provided as a single unitary structure. The first and second output shafts  120 ,  122  may be provided with first and second gears  124 ,  126 , respectively, such as first and second spur or helical gears. The first and second gears  124 ,  126  may have different threads, such as left and right hand threads, in an embodiment in which the drive assembly  38 ′ rotates the first and second output shafts  120 ,  122  in common directions. 
     The first and second gears  124 ,  126  may engage a spur gear  130  that in turn engage the set of teeth  46  on the support post  32 . The spur gear  130  may be rotatably mounted on a pin  132  that may be provided on a bracket or any suitable mounting surface. 
     Operation of the drive assembly  38 ′ may be similar to the embodiments previously discussed. An input signal may be provided to control operation of the electrical machine  80 ′. Operation of the electrical machine  80 ′ may rotate the output shafts  120 ,  122 , which in turn rotate the spur gears  130  which in turn actuate the support post  32 . The support post  32  may move in a first direction represented by the straight arrow line when at least one output shaft  120 ,  122  rotates in a first direction represented by the curved arrow lines, and may move in a second or opposite direction when at least one output shaft  120 ,  122  rotates in the opposite direction. The interface between one or more moveable components, such as the first and/or second gears  124 ,  126  and a respective spur gear  130  may provide a resistive force or act as a locking mechanism that inhibits movement of the support post  32  when the electrical machine  80 ′ is not operated. As such, the headrest may be maintained in a desired position as previously discussed. 
     While embodiments of the invention have been illustrated and described, it is not intended that these embodiments illustrate and describe all possible forms of the invention. Rather, the words used in the specification are words of description rather than limitation, and it is understood that various changes may be made without departing from the spirit and scope of the invention.