Patent Publication Number: US-2019168649-A1

Title: Adjustable head restraint

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a United States National Phase Application of International Application PCT/AU2017/050717 filed Jul. 12, 2017, and claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional application 62/367,102, filed Jul. 26, 2016 and Australian Application 2016903043, filed Aug. 2, 2016, the entire contents of which are incorporated herein by reference. 
    
    
     TECHNICAL FIELD 
     Embodiments generally relate to adjustable head restraints. In particular, embodiments relate to adjustable head restraints suitable for seats, such as automotive seats. 
     BACKGROUND 
     Some head restraints, such as vehicle head restraints, do not permit much adjustment in position. It is desired to address or ameliorate one or more shortcomings or disadvantages associated with prior head restraints, or to at least provide a useful alternative thereto. 
     Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim of this application. 
     Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising”, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps. 
     SUMMARY OF THE INVENTION 
     Some embodiments relate to an adjustable seat head restraint, comprising: a first head restraint part comprising at least one connection component to connect the head restraint to a seat; a second head restraint part; a coupling component to couple the first and second head restraint parts together while allowing relative movement therebetween; and at least one motor to cause one or both of vertical and angular relative movement between the first and second head restraint parts. 
     The first motor may be disposed in the first head restraint part. 
     The second motor may be disposed in the second head restraint part. 
     The second head restraint part may comprise a front cushioning portion for occupant head support and cushioning. 
     The first head restraint portion may be vertically adjustable relative to the seat. 
     Power and/or control signals for operation of the at least one motor may be supplied via an electrical conductor extending through the seat and through the at least one connection component. The at least one motor may comprise a first motor to cause vertical relative movement between the first and second head restraint parts and a second motor to cause angular relative movement between the first and second head restraint parts. 
     The first head restraint part may comprise a mount to which the first motor is coupled, the mount connecting to the at least one connection component. Power and/or control signals may be supplied to the second motor via an electrical conductor passing through the coupling component. Power and/or control signals to the at least one motor can be selectively applied by a control unit nearby, such as within the seat or another part of a vehicle. 
     The at least one connection component may comprise two poles to be received in pole guides in the seat. 
     Some embodiments relate to a method of manufacturing a seat head restraint, comprising: forming a first head restraint part comprising at least one connection component to connect the head restraint to a seat; forming a second head restraint part; coupling the first and second head restraint parts together with a coupling component while allowing relative movement between the first and second head restraint parts; and providing at least one motor arranged to cause one or both of vertical and angular relative movement between the first and second head restraint parts. 
     The at least one motor may comprise a first motor to cause vertical relative movement between the first and second head restraint parts and a second motor to cause angular relative movement between the first and second head restraint parts. Providing at least one motor may comprise disposing the first motor in the first head restraint part. Providing at least one motor may comprise disposing the second motor in the second head restraint part. 
     Embodiments are described in further detail below by way of example, with reference to the accompanying drawings. The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which preferred embodiments of the invention are illustrated. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In the drawings: 
         FIG. 1A  is a front view of a head restraint according to some embodiments in an unextended configuration; 
         FIG. 1B  is a side view of the head restraint of  FIG. 1A ; 
         FIG. 1C  is a rear view of the head restraint of  FIG. 1A ; 
         FIG. 1D  is a top view of the head restraint of  FIG. 1A ; 
         FIG. 2A  is a front view of the head restraint of  FIG. 1A  in an extended configuration; 
         FIG. 2B  is a side view of the head restraint of  FIG. 2A ; 
         FIG. 2C  is a rear view of the head restraint of  FIG. 2A ; 
         FIG. 2D  is a top view of the head restraint of  FIG. 2A ; 
         FIG. 2E  is a perspective view of the head restraint of  FIG. 2A ; 
         FIG. 3  is an exploded perspective view of the head restraint according to some embodiments; 
         FIG. 4A  is a close-up exploded perspective view of a support structure and first mechanism of the head restraint shown in  FIG. 3 ; 
         FIG. 4B  is a perspective view of the first mechanism of  FIG. 4A  in an assembled state; 
         FIG. 4C  is a perspective view of the first mechanism of  FIG. 4A  mounted to the support structure of  FIG. 4A ; 
         FIG. 5A  is an exploded perspective view of a second mechanism of the head restraint shown in  FIG. 3 ; 
         FIG. 5B  is a perspective cutaway view of the second mechanism of  FIG. 5A  in an assembled state; 
         FIG. 5C  is a cross-section showing part of the second mechanism of  FIG. 5A  in further detail; 
         FIG. 6A  is a cross-sectional view of the head restraint showing section A-A as indicated in  FIG. 2D ; 
         FIG. 6B  is a cross-sectional view of the head restraint in an extended configuration showing section B-B as indicated in  FIG. 2D ; 
         FIG. 7A  is a front perspective view showing the second mechanism of  FIG. 5A  mounted to the support structure of  FIG. 4A ; 
         FIG. 7B  is a rear perspective view showing the first mechanism of  FIG. 4A  mounted to the support structure of  FIG. 4A ; 
         FIG. 8  is a perspective view of a support structure mounted to a seat frame according to some embodiments; and 
         FIG. 9  is a side view of the head restraint of  FIG. 1A  illustrating the difference between the extended and unextended configurations. 
     
    
    
     DESCRIPTION OF PREFERRED EMBODIMENTS 
     Referring to the drawings, embodiments generally relate to adjustable head restraints. In particular, embodiments relate to adjustable head restraints suitable for seats, such as automotive seats. Such head restraints may also be described as headrests. 
     Referring to  FIGS. 1A to 1D , a head restraint  100  is shown according to some embodiments. The head restraint  100  comprises a first head restraint part  102  and a second head restraint part  104 . The first head restraint part  102  may be coupled to a seat (not shown) via at least one connection component to mount the head restraint  100  on the seat. The at least one connection component may comprise two support poles  106  as shown in the drawings. The first head restraint part  102  is roughly one half of the whole head restraint  100 , while the second head restraint part  104  is roughly the other half of the head restraint  100 , where the two halves are divided approximately by a vertical or mostly vertical plane.  FIGS. 1A to 1D  show the head restraint  100  with the second head restraint part  104  in an unextended or retracted position or configuration. 
     The second head restraint part  104  is movable relative to the first head restraint part  102  to allow adjustment of the head restraint  100 . The second head restraint  104  may be vertically adjustable relative to the first head restraint part  102 . The second head restraint  104  may be angularly adjustable by rotating or tilting the second head restraint part  104  relative to the first head restraint part  102 . 
     Referring to  FIGS. 2A to 2E , the head restraint  100  is shown in a (fully) extended configuration in which the second head restraint part  104  has been adjusted vertically upwards and tilted away from the first head restraint part  102 . In  FIG. 2A , the second head restraint part  104  is also shown (by a dashed outline) in an unextended configuration as shown in  FIGS. 1A to 1D . As is most easily seen in  FIG. 2B , in the extended configuration, a top portion of the second head restraint part  104  is moved vertically and horizontally away (separated) from the first head restraint part  102  further than a bottom portion of the second head restraint part  104 . In the extended configuration, the bottom portion of the second head restraint part  104  may remain close to or adjacent the first head restraint part  102 . The second head restraint part  104  is movable to various positions between the fully extended position ( FIGS. 2A to 2E ) and the fully retracted position ( FIGS. 1A to 1D ). 
     The head restraint  100  comprises a coupling component  108  that connects the second head restraint part  104  to the first head restraint part  102  and allows relative movement between the first and second head restraint parts  102 ,  104  as described above. 
     The head restraint  100  may comprise one or more mechanisms to control and drive the relative movement between the first and second head restraint parts  102 ,  104 , and may comprise one or more motors which can be operated to adjust the relative position and angle of the second head restraint part  104  relative to the first head restraint part  102 . 
     Referring to  FIG. 3 , an exploded view of the head restraint  100  is shown according to some embodiments. The head restraint comprises a first movement mechanism  140  configured to allow vertical relative movement between the first and second head restraint parts  102 ,  104 , and a second movement mechanism  150  configured to allow angular relative movement between the first and second head restraint parts  102 ,  104 . However, in some embodiments, the vertical and angular movement may be achieved with a single mechanism. The first and second mechanisms  140 ,  150  are described in further detail in relation to  FIGS. 4A to 4C and 5A to 5C , respectively. 
     The first mechanism  140  is housed in the first head restraint part  102 , which comprises a first front housing part  110  and a first rear housing part  112  which cooperate to house the first mechanism  140 . The first head restraint part  102  also houses a mounting structure  114  which mounts the first head restraint part  102  on the supports  106 . As discussed above, each support pole  106  may provide one example of a connection component. In some embodiments, the at least one connection component may comprise internal receiving structures  113  which may form part of the mounting structure  114 . 
     The second mechanism  140  is housed in the second head restraint part  104 , which comprises a second front housing part  120  and a second rear housing part  122 , which cooperate to house the second mechanism  150 . The second head restraint part  104  also houses the coupling component  108  (in the unextended configuration), which is coupled to the mounting structure  114  via a slidable carrier or slider  124 . The second head restraint part  104  further comprises a pad or front cushioning portion  126 , which is configured to fit over the second front housing part  120  for occupant head support and cushioning. 
     Referring to  FIG. 4A , the first movement mechanism  140  is shown in more detail. The slider  124  is configured to be coupled to and slide in tracks  116  in the mounting structure  114 . The first mechanism  140  comprises a first motor  142  mounted (and fixed in position relative) to the mounting structure  114  by a first mounting bracket  143  and configured to drive rotation of a first threaded spindle  144 . A first threaded drive nut  146  is configured to be coupled to the slider  124  and to move along the spindle  144  by threaded engagement when the spindle  144  is rotated by the first motor  142 , thereby moving the slider  124  vertically up or down relative to the first head restraint part  102 . 
     The drive nut  146  includes an aperture  147  configured to receive a locking pin  148 . Referring to  FIG. 4B , the slider  124  comprises a drive nut seat  128  configured to receive at least part of the first drive nut  146  in an internal cavity (not shown) of the drive nut seat  128 . The drive nut seat  128  also includes an aperture (not shown) configured to receive the locking pin  148 . Once the drive nut  146  is received in the drive nut seat  128 , the locking pin  148  may be inserted through the apertures  127 ,  147  to couple the drive nut  146  to the slider  124 . The drive nut seat  128  also defines a top aperture through which the spindle  144  passes as the drive nut seat  128  and drive nut  146  are moved up or down by rotation of the spindle  144 . In some embodiments, the drive nut  146  may be coupled to the slider  124  by a suitable releasable mechanical coupling other than the drive nut seat  128  and locking pin  148 . 
     Referring to  FIGS. 4A and 6B , the mounting structure  114  defines a channel  118  configured to receive and surround part of the drive nut seat  128  and allow it to move along the channel  118  as the slider  124  moves relative to the mounting structure  114 . 
     In some embodiments, the first mechanism  140  may comprise a stop  149  such as a plastic washer, for example, disposed around the first spindle  144 , for example at a base thereof, near the first motor  142 . The stop  149  may restrict the first drive nut  146  from being drawn hard against the first motor  142  and causing thread bind. 
     A distal end  145  of the first spindle  144  (distal to the first motor  142 ) may be received in a recess or slot  115  formed in the mounting structure  114  at an end of the channel  118  as shown in  FIGS. 4A to 4C and 6B . Walls of the channel  118  adjacent the slot  115  may also act as a stop to limit the movement of the drive nut seat  128  and first drive nut  146  along the first spindle  144 . 
     Referring to  FIGS. 5A to 5C , the second mechanism  150  is shown in more detail. The coupling component  108  is coupled to the slider  124 , for example by suitable coupling mechanisms, such as fasteners, so that the second head restraint part  104  moves vertically with the slider  124 . The second front housing part  120  is pivotally coupled to the coupling component  108  at a first axis  152  shown as D 1 -D 2  in  FIG. 5A  and forming Joint ‘D’ elsewhere in the drawings. First axis  152  is positioned at a lower front portion of the second front housing part  120 . A lever  154  is pivotally coupled to the coupling component  108  at a second axis  156  shown as A 1 -A 2  in  FIG. 5A  and forming Joint ‘A’ elsewhere in the drawings. The second axis  156  is generally defined by the coupling component  108  to be generally vertically above the first axis  152 . The lever  154  is also pivotally connected to the second front housing part  120  at a third axis  158  shown as C 1 -C 2  in  FIG. 5A  and forming Joint ‘C’ elsewhere in the drawings. The third axis  158  is horizontally offset in a rearward direction from the first and second axes  152 ,  156 . The third axis  158  rotates around the second axis  156  in response to operation of the second motor  162 . The front housing part  120  may comprise one or more brackets  123  defining apertures to couple the front housing part  120  to the lever  154  to form Joint ‘C’. 
     The second mechanism  150  comprises a second motor  162  mounted to the coupling component  108  by a second mounting bracket  163  and configured to drive a second threaded spindle  164 . A second drive nut  166  is configured to threadedly move along the second spindle  164  when it is rotated by the second motor  162  by engagement of complementary screw threads on the second spindle  164  and the second drive nut  166 . The second drive nut  166  is pivotally coupled to the lever  154  at a fourth axis  160  coinciding with apertures defined by the lever  154 , such that when the second motor  162  is actuated, the second drive nut  166  is moved along the second spindle  164  to rotate the lever  154  relative to the coupling component  108  and thereby tilt the second head restraint part  104  relative to the coupling component  108  and the first head restraint part  104 . Lever  154  defines a second drive nut seat (not shown) therein to receive the second drive nut  166 . The lever  154  allows rotation of the second drive nut  166  within the second drive nut seat as the drive nut  166  progress along the spindle  164 . The fourth axis  160  is shown as B 1 -B 2  in  FIG. 5A  and forming Joint ‘B’ elsewhere in the drawings. The fourth axis  160  is generally vertically below the third axis  158 , is horizontally offset from the first and second axes  152 ,  156  and rotates relative to the first and second axes  152 ,  156  in response to actuation of the second motor  162 . The first, second, third and fourth axes  152 ,  156 ,  158  and  160  are all substantially parallel with each other. 
     The second mechanism  150  may comprise an end cap or stop tube  168  to limit movement of the second drive nut  166  along the second spindle  164 . A slot or groove  165  may be defined in the second spindle  164  at or near a distal end of the spindle  164 . The stop tube  168  may be crimped onto the spindle  164  and into the groove  165 . In some embodiments, the end cap or stop tube  168  may comprise a clip or barbs configured to engage the groove  165  and restrict removal of the stop tube  168  from the second spindle  164 . The second mechanism  150  may further comprise plastic washers  169  disposed around the second spindle  164  on either side of the second drive nut  166  to restrict the second drive nut  166  from being drawn hard against the second motor  162  or stop tube  168  and causing thread bind. 
     The head restraint  100  may further comprise a cover  109  to hide the coupling component  108  and internal mechanisms of the head restraint  100 . The cover  109  may be fixed relative to the first head restraint part  102  and may define a curved surface configured such that, as the second mechanism  150  is actuated to rotate the second head restraint part  104  relative to the first head restraint part  102  to adjust the angular position of the second head restraint part  104 , a constant clearance is maintained between the cover  109  and the second head restraint part  104 . The clearance may be in the range of about 0.1 mm to 5 mm, optionally about 0.5 mm to 3 mm, optionally about 1 mm to 2 mm. 
     Referring to  FIG. 6B , a cross-section of the first and second mechanisms  140 ,  150  is shown, illustrating the angular displacement or motion caused by the second mechanism  150  in the fully extended position. A first arc  171  is shown, illustrating the range of angular motion or rotation of a top part of the second head restraint part  104  relative to the first head restraint part  102  about axis  152  (Joint ‘D’). A second arc  172  illustrates the path (or motion range) of Joint ‘B’  160  as the lever  154  rotates about axis  156  (Joint ‘A’) to the fully extended position. A third arc  173  illustrates the path (or motion range) of Joint ‘C’  158  as the lever  154  rotates about axis  156  (Joint ‘A’) to the fully extended position. 
     As the second drive nut  166  moves up and down over time along the second spindle  164  (by actuation of the second motor  162 ) and drives the motion of the lever  154 , the movement of Joint ‘B’  160  (and thus the second drive nut  166 ) through the second arc  172  will cause the second spindle  164  to oscillate. That is, as the second motor is operated at various times in a backward or forward driving direction, a longitudinal axis  174  of the second spindle  164  will be rotated such that the distal end of the second spindle  164  is caused to move back and forth, towards and away from the first head restraint part  102 . This motion may also rock the second motor  162  back and forth in a similar manner. In order to allow for this oscillation and mitigate against such oscillation causing bending stress between the second motor  162  and the second spindle  164 , the second motor  162  may be mounted to the second mounting bracket  163  with flexible or deformable washers  161  disposed between the second motor  162  and the second mounting bracket  163 . Alternatively, the second motor  162  may be mounted to the second mounting bracket  163  in a way that allows for some angular deflection or rotation of the second motor  162  relative to the mounting bracket  163  as the spindle  164  is angularly deflected by the action of the drive nut  166  and the lever  154 . 
     Coupling component  108  acts as a mounting bracket for the second motor  162  and for pivot couplings, such as screws, to allow pivotal movement of the lever  154  relative to the coupling component  108  and allow pivotal movement of the coupling component relative to the second front housing part  120 . The coupling component  108  has a slotted aperture formed in a central web thereof, with the spindle  164  extending through the slotted aperture. The slotted aperture allows for some back and forth movement of the spindle  164  as it interacts with the drive nut  166  and the lever  154 , as described above. The structure of the coupling component  108  resembles a chair (as seen from the perspective shown in  FIG. 5A ), with an upper back part comprising a stiffening plate  188  and side plate portions extending from the stiffening plate  188  in a forward direction resembling chair arms. The central web that defines the slotted aperture is integrally formed with the side plate portions and the stiffening plate  188  and resembles a seat of the chair-like structure of the coupling component. A front mounting section of the coupling component  108  (spaced from the back stiffening plate  188 ) defines opposed apertures defining the first and second axes  152 ,  156  and that receive pivot couplings, such as screws, that allow pivoting about the axes  152 ,  156 . The second mounting bracket  163  extends rearwardly from a front of the coupling component  108  and resembles a foot of the chair-like structure of the coupling component  108 . 
     In general, the components described herein may be formed of any suitable materials with sufficient stiffness to support the expected design loads. For example, in order to meet safety standards for a head restraint for an automotive seat, the head restraint  100  must provide a certain level of support and resistance to impact loads which are predicted in certain car collisions. Some suitable materials for the components described are metals, metal alloys, steel, aluminum, or rigid plastics, such as acetal, for example. 
     In some embodiments, the slider  124  may be formed of a rigid plastic  180  molded around a metal reinforcing structure such as a metal plate  181  as shown in  FIGS. 6A and 6B . 
     In some embodiments, the coupling component  108  may be formed or molded in steel or other metal or molded in rigid plastic around a steel (or other metal) stiffening plate  188 . The stiffening plate  188  may provide reinforcement and strengthen the connection between the slider  124  and the coupling component  108 . 
     In some embodiments, the head restraint mounting structure  114  may be formed of a rigid plastic molded over the support poles  106 . In some embodiments, the support poles  106  may comprise hollow steel tubes. The tubes may have a 150 mm pitch, for example. 
     In some embodiments, power and/or control signals for operation of the first and second motors  142 ,  162  may be supplied via the seat and through the at least one connection component. For example, electrical wiring may be passed through the hollow support poles  106  to connect the first and second motors  142 ,  162  to a power supply (not shown). In some embodiments, power and/or control signals may be supplied to the second motor  162  via an electrical conductor passing through the coupling component  108 , slider  124  and/or mounting structure  114 . 
     Referring to  FIGS. 7A and 7B , a first power/signal cable  190  may extend through one of the support poles  106  to supply power to the first motor  142  and a second power/signal cable  192  may extend through another one of the support poles  106  to supply power to the second motor  162 . The second cable  192  may also pass through apertures in the mounting structure  114 , slider  124  and coupling component  108  to connect the second motor  162  to the power supply. 
     The first cable  190  may terminate in a first connector  191  configured to connect the first cable  190  to wiring within the main body of a car seat, for example. The second cable  192  may terminate in a second connector  193  configured to connect the second cable  192  to wiring within the main body of the car seat, for example. The first and second motors  142 ,  162  may be controlled by actuation of one or more manually operable switches (not shown) electrically coupled to a controller (not shown), which controls the supply of power to each motor  142 ,  162 . In some embodiments, a controller may not necessarily be required and the switches may be directly coupled to the power supply and the motors  142 ,  162  to control the supply of power to the motors  142 ,  162 . For example, the switches may comprise reverse polarity switches, one switch associated with each of the motors  142 ,  162 . The switches may be mounted in the car seat or in a dashboard of the car, and may allow a user to operate each motor  142 ,  162  in both directions to move the second head restraint part  104  up and down and tilt the second head restraint part  104  towards and away from the first head restraint part  102 . This allows adjustment of the head restraint in four directions (up, down, back and forward). 
     In some embodiments, the support poles  106  may be received and/or mounted in pole guides (not shown) to connect the support poles  106  to a car seat frame in a manually height-adjustable manner. In some embodiments, as shown in  FIG. 8 , the support poles  106  may be connected directly to the car seat frame  800  in a non-adjustable manner. Connections  802  between the support poles  106  and the car seat frame  800  may comprise welded joints, for example. 
     Referring to  FIG. 9 , the head restraint  100  is shown illustrating the difference between the extended and unextended configurations. As described above, the first and second mechanisms  140 ,  150  allow vertical and angular adjustment of the second head restraint part  104  relative to the first head restraint part  102 . The second head restraint part  104  is indicated as  104   a  in an unextended position adjacent the first head restraint part  104  (i.e., with the head restraint  100  in the unextended configuration). The second head restraint part  104  is indicated as  104   b  in an extended position fully extended away from the first head restraint part  102  (i.e., with the head restraint  100  in the extended configuration). However, the first and second mechanisms  140 ,  150  allow adjustment of the vertical and angular position of the second head restraint  104  over a continuous range of distances and angles that are intermediate the unextended and fully extended positions. That is, the second head restraint part  104  may be adjustable to a plurality of intermediate positions between the extended and unextended positions. For each angular position, the vertical position may be adjusted continuously over the full vertical range, and for each vertical position, the angular position may be adjusted continuously over the full angular range. 
     The first mechanism  140  may be configured to allow adjustment of the vertical position of the second head restraint part  104  by a distance of up to about 200 mm, optionally up to about 100 mm, optionally up to about 56 mm, optionally up to about 30 mm. 
     The second mechanism  150  may be configured to allow adjustment of the angular position of the second head restraint part  104  away from the first head restraint part  102  by an angle of up to about 30°, optionally up to about 20°, optionally up to about 17°, optionally up to about 15°, optionally up to about 10°, optionally up to about 5°. 
     It will be appreciated by persons skilled in the art that numerous variations and/or modifications may be made to the above-described embodiments, without departing from the broad general scope of the present disclosure. The present embodiments are, therefore, to be considered in all respects as illustrative and not restrictive. 
     While specific embodiments of the invention have been shown and described in detail to illustrate the application of the principles of the invention, it will be understood that the invention may be embodied otherwise without departing from such principles.