Abstract:
An adjustable headrest that provides both support and comfort to the user and one that can be used in connection with furniture including household and office furniture and also in connection with various types of passenger vehicles. The headrest includes slide means for permitting easy height adjustment of the headrest and also includes locking means for securely locking the headrest in a desired elevated position. Further, the headrest includes easily adjustable, wing-like, side-support members that are pivotally connected to a centrally located, vertically adjustable head support member by means of constant torque hinges and also includes easily adjustable chin support members that are pivotally connected to the side support members by means of constant torque hinges.

Description:
BACKGROUND OF THE INVENTION 
     This is a Continuation-In-Part application of application Ser. No. 09/886,924, filed Jun. 20, 2001, which is a Continuation-In-Part of application Ser. No. 09/665,992, filed Sep. 20, 2000, now U.S. Pat. No. 6,250,716. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to headrests for seats. More particularly, the invention concerns a fully adjustable headrest for use in connection with furniture and with passenger vehicles such as aircraft, trains and busses. 
     DISCUSSION OF THE PRIOR ART 
     Various types of headrests for use in passenger vehicles have been suggested in the past. As the general rule, these headrests are designed primarily to satisfy safety aspects rather than to provide a comfortable seating posture. Typically, the prior art vehicle headrests comprise only a vertically adjustable head support member designed to provide protection against injury in the event of an accident. However, some vehicle headrests have also been provided with lateral headrest elements. Exemplary of such a headrest is that described in U.S. Pat. No. 5,997,091 issued to Rech et al. 
     In addition to passenger vehicle headrests, a number of headrests have been designed for use in a emergency vehicles. These types of headrests are of a more complicated design and some include greater adjustability features. Exemplary of these types of headrests are those disclosed in U.S. Pat. No. 5,275,462 and in U.S. Pat. No. 5,934,749 both issued to Pond et al. 
     Even more complex headrests have been designed for use in military aircraft and, more particularly in military aircraft for use in conjunction with ejection seats. Typical of this class of headrest design are those disclosed in U.S. Pat. No. 4,883,243 and U.S. Pat. No. 4,899,961 both issued to Herndon. Another such headrest design is disclosed in U.S. Pat. No. 4,466,662 to issued to McDonald et al. 
     In addition to the development of headrests for use in military aircraft, significant advances have been made in recent years in the design of headrests for use in commercial aircraft. Many of these headrests are designed for personal comfort and include pivotally movable back and lateral supports. In these latter types of headrests, the head support members are typically slidably mounted on spaced apart rods that extend upwardly from the back of the seat and rely on friction to maintain the headrest in an elevated position. 
     As will become clear from the discussion that follows, the headrests of the present invention represents a substantial improvement over the prior art headrests and provide significantly greater adjustability and therefore greater support and comfort to the user. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide an adjustable headrest that provides both support and comfort to the user and can be used in connection with furniture including household and office furniture and also in connection with various types of passenger vehicles. 
     Another object of the invention is to provide a headrest of the aforementioned character that includes slide means for permitting easy height adjustment of the headrest and also includes locking means for securely locking the headrest in a desired elevated position. 
     Another object of the invention is to provide easily adjustable, wing like, side support members that are pivotally connected to a centrally located, vertically adjustable head support member by means of constant torque hinges. 
     Another object of the invention to provide easily adjustable chin support members that are pivotally connected to the side support members by means of constant torque hinges. 
     Another object of the invention is to provide an adjustable headrest construction of the character described that includes strategically positioned comfort cushions for engagement by the user&#39;s neck, head and chin. 
     Another object of the invention is to provide an adjustable headrest construction of the type described in the preceding paragraphs in which the cushions are readily inflatable and deflatable. 
     Another object of the invention is to provide a headrest construction of the class described that is of a simple construction and one that can be inexpensively produced and easily installed. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a front view of one form of the seat headrest apparatus of the invention partly broken away to show internal construction. 
     FIG. 2 is a view taken along lines  2 — 2  of FIG.  1 . 
     FIG. 3 is an enlarged, cross-sectional view taken along lines  3 — 3  of FIG.  1 . 
     FIG. 4 is a view taken along lines  4 — 4  of FIG.  3 . 
     FIG. 5 is an enlarged, cross-sectional view taken along lines  5 — 5  of FIG.  1 . 
     FIG. 6 is a view taken along lines  6 — 6  of FIG.  5 . 
     FIG. 7 is an enlarged, cross-sectional view taken along lines  7 — 7  of FIG.  1 . 
     FIG. 8 is a view taken along lines  8 — 8  of FIG.  7 . 
     FIG. 8A is a view similar to FIG. 8, but showing the support assembly raised and the pawl type locking mechanism thereof in a locked position preventing downward movement of the support assembly. 
     FIG. 9 is a cross-sectional view taken along lines  9 — 9  of FIG.  8 . 
     FIG. 10 is a front view of one form of the slide mechanism of the invention. 
     FIG. 11 is a cross-sectional view similar to FIG. 7, but showing the head support assembly in an intermediate upraised position. 
     FIG. 11A is a generally perspective view of the apparatus of the invention shown affixed to the seat and illustration the articulation of the various support components of the headrest assembly of the apparatus. 
     FIG. 12 is a front view of an alternate form of the headrest apparatus of the invention having inflatable cushions or air bags affixed to the various support members of the apparatus. 
     FIG. 13 is an enlarged, cross-sectional view taken along lines  13 — 13  of FIG.  12 . 
     FIG. 14 is a front view of the apparatus shown in FIG. 12 as it appears when affixed to a seat. 
     FIG. 15 is a view similar to FIG. 14 but showing the support assembly in a raised position. 
     FIG. 16 is a generally schematic, block diagram view showing the various components that make up the control means of the apparatus for inflating and deflating the air bags. 
     FIG. 17 is a front view of an alternate form of seat headrest construction of the present invention. 
     FIG. 18 is a view taken along lines  18 — 18  of FIG.  17 . 
     FIG. 19 is a cross-sectional view taken along lines  19 — 19  of FIG.  17 . 
     FIG. 20 is a cross-sectional view taken along lines  20 — 20  of FIG.  17 . 
     FIG. 21 is a greatly enlarged, generally prospective view of one of the hinge assemblies that connects the front and back portions of the headrest. 
     FIG. 22 is a generally prospective view of one form of the carriage assembly of the invention that interconnects the front portion of the headrest with the rear portion thereof. 
     FIG. 23 is an enlarged, cross-sectional view taken along lines  23 — 23  of FIG.  17 . 
     FIG. 24 is a greatly enlarged, cross-sectional view taken along lines  24 — 24  of FIG.  23 . 
     FIG. 25 is a cross-sectional view taken along lines  25 — 25  of FIG.  23 . 
     FIG. 26 is a cross-sectional view taken along lines  26 — 26  of FIG.  23 . 
     FIG. 27 is front view of an alternate form of the headrest assembly of the present invention. 
     FIG. 28 is a rear view of the alternate form of the headrest assembly of the invention shown in FIG.  27 . 
     FIG. 29 is a plan view of the seat connector assembly of the apparatus that interconnects the headrest assembly with the aircraft seat. 
     FIG. 30 is a cross-sectional view taken along lines  30 — 30  of FIG.  27 . 
     FIG. 31 is a cross-sectional view taken along lines  31 — 31  of FIG.  27 . 
     FIG. 32 is a generally perspective view of the resistance imparting means of this latest form of the invention. 
     FIG. 33 is a cross-sectional view taken along lines  33 — 33  of FIG.  30 . 
     FIG. 34 is an enlarged, cross-sectional view taken along lines  34 — 34  of FIG.  33 . 
     FIG. 35 is a generally perspective, fragmentary view of the roller guide component of this latest form of the invention. 
    
    
     DESCRIPTION OF THE INVENTION 
     Referring to the drawings and particularly to FIGS. 1,  2 , and  11 A, one form of the seat headrest of the invention is there illustrated and generally designated by the numeral  14 . The seat headrest here comprises a seat connector assembly  16  that includes a connector member  18  that is connected to the seat “S” by any suitable means such as threaded connectors  20  (FIGS.  2  and  8 ). A support assembly  21  is slidably connected to connector member  18  for movement between a first position shown in FIG. 7 to an intermediate position shown in FIG.  11  and to an upraised position shown in FIG.  11 A. 
     Support assembly  21  here comprises a slide mechanism  22 , including a track  24 , that is connected to connector member  18  by a suitable connector such as connector  24   a  (FIGS.  7  and  10 ). Slide mechanism  22  also includes a slide assembly  26  that slides within track  24  in a manner presently to be described. Connected to slide assembly  26  by a threaded connector  28   a  is a mounting member  28  (FIG.  7 ). A first head support member  30  is pivotally connected to member  28  by means of a friction hinge pivot assembly  34  that includes a transversely extending pivot pin  36  and a connector bracket  37  (FIGS.  7  and  8 ). With this construction, first support member  30  can be pivoted about the axis of the shaft  36   a  of a connector bolt  36  from a first position adjacent mounting member  28  to an angularly outwardly extending position as shown in FIGS. 7 and 11A. As best seen in FIG. 8, bracket  37  includes spaced apart apertured legs  37   a  that receive the shaft of bolt  36 . Disposed between legs  37   a  is a bearing  37   b  having a transverse bore that receives shaft  36   a  of bolt  36 . With this construction, when nut  36   b  is snugged down against one of the legs, pivoting of support member  30  will be controllably frictionally resisted. 
     Pivotally connected to first head support member  30  by a constant torque hinge  38  is a first lateral, or side wing  40  that is pivotally movable from the position shown in FIGS. 1 and 2 wherein it is substantially coplanar with head support member  30  to a second angularly extending forward position shown by the phantom lines in FIG.  2 . In similar fashion, a second, or lateral side wing  42  is connected to the opposite side of support member  30  by a constant torque hinge  44  that is of identical construction to constant torque hinge  38 . Side wing  42  is also pivotally movable from the substantially coplanar position shown in FIG. 2 to the angularly outwardly extending position shown by the phantom lines in FIG.  2 . When side wings  40  and  42  are pivoted into the position shown by the phantom lines in FIG. 2, they can provide a comfortable lateral support to the passenger&#39;s head “H” in the manner shown in FIG.  2 . 
     Hingedly connected to side wing  40 , by means of a constant torque, friction imparting hinge  46  is a first chin support  48 . Similarly, a second chin support  50  is hingedly interconnected with side wing  42  by means of a constant torque hinge  52  that is of identical construction to hinge  46  (FIG.  1 ). Constant torque hinges  38 ,  44 ,  46  and  52 , which are readily commercially available from sources such as Reel Precision Manufacturing of St. Paul, Minn. function to maintain the side wings and chin supports in a selected position until a substantial force is exerted on the hingedly connected member to positively move it into a different position. More particularly, as best seen in FIG. 6, each of the constant torque hinges includes a torsion spring  53  that circumscribes pivot pin or rod  55  and engages the leaves of the hinge in a manner such that relative pivotal movement of the leaves of the hinges produce a constant torque tending to continuously resist the relative pivotal movement of the leaves. In this way, movement of one of the hingedly support members relative to the other is continuously, positively resisted. The use of the constant torque spring hinges in this manner uniquely overcomes a common drawback of prior art head rest construction in which the hingedly connected members tend to undesirably move as a result of vibration and other environmental forces. It is to be understood that a friction-imparting, constant-torque hinge could also be used to hingedly connect first head support member  30  to member  28 . 
     Referring particularly to FIGS. 7,  8 ,  9 ,  10 , and  11 , the novel slide means of the invention for slidably interconnecting the support assembly  21  with seat connector member  18  is there illustrated. In the present form of the invention, this slide means comprises the previously identified slide mechanism  22  which is of conventional construction and is readily commercially available from sources such as Dirak Gmbh &amp; Co. of Ennepetal, Germany. As previously mentioned slide assembly  26  is controllably movable within track  24  from the position shown in FIG. 7 wherein slide member is substantially enclosed within the hollow housing portion of track  24  to a second extended position wherein the slide assembly extends outwardly from the track housing  24  a substantial distance. 
     As best seen by referring to FIGS. 9,  10  and  11 , the hollow housing of track  24  includes having an upper surface  24   a  that is provided with a plurality of spaced-apart, angularly, downwardly extending notches  60  that are configured to receive the locking pin  62   a  of a pawl  62  that is carried by track  24  for pivotal movement between a first retracted position shown in FIGS. 8 and 10 to a second position shown in FIG. 8A wherein pin  62   a  is urged into a selected notch by means of a biasing spring  62   b . With this construction, as slide  26  moves upwardly within track  24 , locking pin  62   a  will ride over the tooth-like portions  60   a  located intermediate to notches  60 . However, due to the urging of spring  62   b , pin  62   a  will drop into a selected notch when upward movement of the slide assembly ceases. When locking pin  62   a  has thusly been urged into a selected notch, downward movement of slide assembly will be positively prevented. However, when the slide assembly reaches its uppermost position, pawl  62  will enter slot  60   b  (FIG. 10) where it will once again move into a retracted position permitting the support assembly to move downwardly toward its starting position. As indicated in FIG. 9, mounting member  28 , which is interconnected with slide assembly  26  and moves therewith, is guided by guide means shown here as a pair of spaced-apart guide brackets  65  that are connected to connector member  18  by threaded connectors  67 . Each of the brackets  65  includes an angularly outwardly extending segment  65   a  that guidingly engage the sloping side walls  28   a  of mounting member  28 . 
     Turning next to FIGS. 12 through 16, an alternate form of the headrest apparatus of the present invention is there illustrated. This form of the invention is similar in many respects to that illustrated in FIGS. 1 through 11 and previously described herein. Because of the similarity of these embodiments, like numbers are used in FIGS. 12 through 16 to identify like components. The principal difference between this latest embodiment of the invention and that earlier described resides in the fact that inflatable cushions or air bags are attached to the various support components that make up the headrest assembly. More particularly, as shown in FIG. 12, three inflatable air bags or bladders  70 ,  71 , and  72  are interconnected with the lower portion of support member  30 , while a single air bag  74  is affixed to each of the side panels  40  and  42 . In similar fashion, first and second air bags or bladders  76  and  78  are attached to each of the chin support members  48  and  50 . Air bags  70 ,  71 , and  72  are disposed below a main cushion  80  that is affixed to the upper portion of support member  30 . Similarly, air bag  74  is positioned below a larger support cushion  82  that is affixed to side wing  40  while inflatable air bag  74  is disposed beneath a larger cushion  84  that is affixed to side wing  42 . Cushions  82  and  84  can be of a conventional padded cushion construction, or, if desirable, could also be inflatable bladder components. When installed to the support component in the manner illustrated in FIG. 12, the supporting cushions and inflatable air bags are covered by a conventional upholstery cover  87  so that the assembly takes on the finished configuration shown in FIG.  14 . Covering  87  can be of fabric or vinyl material and is suitably flexible to enable the inflation and deflation of the bladder component without unduly stressing the cover material. FIG. 15 illustrates the support assemblage shown in FIG. 14 in the upraised position wherein the support assembly has been moved to the uppermost position by sliding it along the sliding mechanism which is of the character previously described. 
     Referring to FIG. 16, one form of the control system, or control means of the invention for operating the air bags, or inflatable cushions, is there illustrated in schematic form. Shown in the left-hand portion of FIG. 16 are the inflatable bladders that have been previously identified and that are connected to the left, center and right support members. As indicated in FIG. 16, central bladder  70  is interconnected by means of a pneumatic hose  88  with an air pump  90  via a pneumatic junction  92  and a first solenoid valve  94 . Bladders  74  are, in turn, connected to bladder  70  by pneumatic hoses  88   a . Similarly, inflatable bladder  71  is interconnected by means of a pneumatic hose  96  with pump  90  via pneumatic junction  92  and a second solenoid valve  98 . Bladders  76  are, in turn, connected to bladder  71  by pneumatic hoses  96   a . In similar manner, inflatable bladder  72  is interconnected by means of a pneumatic hose  100  with air pump  70  via pneumatic junction  92  and a third solenoid valve  102 . Bladders  78  are, in turn, connected to bladder  72  by pneumatic hoses  100   a . First solenoid valve  94  is interconnected by means of an electric connnector  104  with the central processing unit  106  of the apparatus via a first relay  108 . Similarly, second solenoid  98  is interconnected by means of an electrical conduit  110  with central processing unit  106  via a second relay  112 . In similar manner third solenoid valve  102  is interconnected by means of an electrical conduit  114  with central processing unit  106  via a third relay  116 . Air pump  90  is interconnected with pneumatic junction  92  by means of an air hose  120 . Motor pump  90  is also operably interconnected with central processing unit  106  by an electrical connector  122 . Central processing unit  106  is of a conventional construction that is readily commercially available and is powered by a conventional external power source. Similarly pump  90 , pneumatic junction  92 , as well as the solenoids and relays that make up the control system are well understood by those skilled in the art and are also readily commercially available. 
     Central processing unit  106  is operably interconnected by an electrical connector  126   a  with an occupant control means, shown here as a control panel  126 . In the form of the invention shown in FIG. 16, occupant control panel  126  includes an inflate switch  130  for use in inflating the bladders and a deflate switch  132  for use in deflating the bladders. Also provided on occupant panel  126  is an on/off massage switch  140  that can be manipulated to cause a massaging type action to be imparted to the passenger by the sequential inflation and deflation of the air bags or bladders that are affixed to the various support members. Switch  140  is operably coupled with switches  134  and  136  to enable faster and slower massage cycle rates. With the construction shown in FIG. 16, the inflatable air bags, or bladders, can be inflated or deflated independently either in series or in parallel for the purpose of controlling bladder firmness or for performing an upper back, neck, face and head message cycle for a preprogrammed time in accordance with a program contained within central processing unit  106 . Once again, switches  130 ,  132 ,  134 , and  136  are of a conventional design well understood by those skilled in the art. 
     Motor pump  90  can be powered by an existing seat power supply as, for example, a seat controller lumbar controller, seat motor controller or the like, or it may be powered by a power supply interconnected with and dedicated to motor pump  90 . It is to be understood that the electrical and pneumatic interconnection shown schematically in FIG. 16 is well understood by those skilled in the art as is the necessary programming of central processing unit  106  to accomplish the desired inflation and deflation sequencing of the various air bags or bladders. 
     For certain end use application, central support member  30  can be provided with a greater or lesser number of inflatable air bags. Similarly, side panels  40  and  42  may have more than one air bag and chin support member  48  can be provided with one, two or more inflatable bladders as may be desired by the system designer. Similarly the occupant control panel can be designed to accommodate more or less inflatable bladders and may also be designed to cooperate with the central processing unit to accomplish various other inflation/deflation and message type cycles as may be desired for the particular vehicle in which the apparatus is installed. 
     Referring next to FIGS. 17 through 26, an alternate form of seat headrest of the invention is there illustrated and generally designated by the numeral  114 . This latest embodiment of the invention comprises a seat connector assembly  116  that includes a generally planar first connector member  118  that is connected to the seat “S” by any suitable means. Slidably connected to first connector member  118  for movement between a first lowered position shown by the solid lines in FIG. 17 to an upraised position shown by the phantom lines in FIG. 17 is a head support assembly  220  (see also FIG.  26 ). 
     As best seen in FIG. 24, head support assembly  220  includes a carriage assembly  221  to which a generally planar central support member or panel  222  is pivotally connected by means of a constant torque hinge  224  (FIG.  19 ). Connected to central support panel  222  by a constant torque hinge  225  is a first lateral or side panel  226 , which is pivotally movable, a first position wherein it is substantially coplanar with central support panel  222  to a second angularly extending forward position. In similar fashion a second or lateral side panel  228  is connected to the opposite side of central support member  222  by a constant torque hinge  230  that is of identical construction to constant torque hinge  225 . Side panel  228  is also pivotally movable from a substantially coplanar position with central support panel  222  to an angularly outwardly extending position. When side panel&#39;s  226  and  228  are pivoted into the angularly outwardly extending position, they provide a comfortable lateral support to the passenger&#39;s head “H” in the manner shown in FIG.  2 . Constant torque hinges  225  and  230  are readily commercially available and function to maintain the side panels in a position desired by the user until a substantial force is exerted on the hingedly connected member to positively move it into a different position. As before, use of these constant torque hinges overcomes a common drawback of prior art headrest construction in which the hingedly connected members tend to undesirably move as a result of vibration or other environmental forces. 
     As indicated by the arrow  231  in FIG. 18, constant torque hinge  224  permits the headrest assembly  220  to be adjustably pivoted both forwardly and rearwardly relative to the seat connector assembly  116 . Constant torque hinge  224 , which is readily commercially available from several commercial sources, including Torqmaster, International of Stamford, Conn., functions to maintain the headrest assembly  220  in a position desired by the user until a substantial force is exerted on the headrest assembly to positively move it into a different position. As shown in FIGS. 20 and 23, hinge  224  is mounted on a plate  233  and includes a housing  224   a  that carries a steel shaft  224   b  that, in turn, carries a plurality of spring steel friction bands  224   c  that function to controllably resist rotation of plate  223  and panel  222  that is attached thereto relative to connector assembly  116 . Connected to seat connector member  118  is an elongated guide  238  that includes oppositely disposed guide rails  238   a  (FIG. 19) that are adapted to be rollably engaged by two pairs of spaced apart roller assemblies  244  that are mounted on carriage assembly  221 . The roller assemblies  244 , each of which are of identical construction, include a threaded connecting shaft  244   a  that is threadably connected to carriage assembly  221  and a grooved roller  244   b  that is rotatably mounted on shaft  244   a . With this construction, carriage assembly  221  along with headrest assembly  220  can be adjustably moved upwardly and downwardly relative to seat connector member  118  so as to enable the desired adjustment in the height of the headrest assembly relative to the seat connector member. 
     Forming and important aspect of the headrest assembly of this latest form of the invention is resistance imparting means for imparting resistance to the movement of head rest assembly  220  upwardly and downwardly relative to connector member  118 . In the present form of the invention, this novel resistance imparting means comprises a uniquely configured leaf spring designated in the drawings by the numeral  247 . As best seen in FIGS. 22 and 24, spring  247  includes a central portion  247   a  that is affixed to carriage assembly  221  in the manner shown in the drawings. Spring member  247  also includes a pair of outwardly extending yieldably deformable side members  274   b  that are connected to central portion  247   a . Each of the side members  247   b  terminates in a surface engaging portion  247   c . As best seen in FIG. 24, when the resistance means is fully assembled portions  247   c  are substantially parallel to central portion  247   a . With this construction, when carriage assembly  221  is interconnected with seat connector member  118  in the manner shown in FIG. 24, spring member  247  will be yieldably deformed in the manner shown in FIG. 24 so that surface engaging portions  247  are brought into pressural engagement with seat connector member  118 . As the headrest assembly is moved upwardly and downwardly in the manner indicated in FIG. 26, surface engaging portions  247   c  will frictionally engage the outer surface of connector member  118  and will yieldably resist sliding movement of carriage assembly  221  relative to seat connector member  118 . In the preferred form of the invention a plastic film  249  is disposed between surface engaging portions  247   c  and connector member  118  so as to insure smooth sliding of the headrest assembly relative to the connector member. 
     Turning now to FIGS. 27 through 35, still another form of seat headrest of the invention is there illustrated and generally designated by the numeral  254 . This latest embodiment of the invention is similar and several respects to the earlier described embodiments and like to numerals are used in FIGS. 27 through 36 to identify like components. This latest embodiment of the invention comprises a seat connector assembly  256  (FIG. 29) that includes a generally planar first connector member  258  that is connected to the seat “S” by any suitable means. Slidably connected to first connector member  258  for movement between a first lowered position shown by the phantom lines in FIGS. 27 and 28 and an upraised position shown by the solid lines in FIGS. 27 and 28 is a head support assembly  260  (see also FIG.  31 ). 
     As best seen in FIGS. 27,  28  and  30 , head support assembly  260  includes a generally planar central support member or panel  262  to which an elongated guide member  264  is connected by means of connectors  265  (FIG.  31 ). A first lateral or side panel  266  is pivotally connected to the central support member by means of a constant torque hinge  225 . Also connected to central support panel  262  by a constant torque hinge  230  is a second lateral or side panel  268 . As indicated in FIG. 30, side panels  266  and  268  are pivotally movable, a first position shown by solid lines in FIG. 30 wherein they are substantially coplanar with central support panel  262  to a second angularly extending forward position shown by phantom lines in FIG.  30 . When side panel&#39;s  266  and  268  are pivoted into the angularly outwardly extending position, they provide a comfortable lateral support to the passenger&#39;s head in the manner previously described and as shown in FIG.  2 . 
     The earlier identified elongated guide member  264  includes oppositely disposed guide rails  264   a  (FIGS. 33,  34  and  35 ) that are adapted to be rollably engaged by two pairs of spaced apart roller assemblies  270  that are mounted on connector member  258 . The roller assemblies  270 , each of which are of identical construction, include a connecting shaft  272  that is connected to connector member  258  and a grooved roller  274  that is rotatably mounted on shaft  272  (FIG.  34 ). With this construction the headrest assembly  260  can be adjustably moved upwardly and downwardly relative to seat connector member  258  so as to enable the desired adjustment in the height of the headrest assembly relative to the seat connector member. As the headrest assembly is moved upwardly and downwardly, guide means, shown here as a pair of internal ears  275  formed on support member  258  (FIG.  30 ), slidably engage guide member  267  to guide the travel of the headrest assembly. 
     Forming and important aspect of the headrest assembly of this latest form of the invention is resistance imparting means for imparting resistance to the movement of head rest assembly  260  upwardly and downwardly relative to connector member  258 . In the present form of the invention, this novel resistance imparting means comprises a uniquely configured leaf spring designated in the drawings by the numeral  277 . As best seen in FIGS. 31 and 32, spring  277  includes a first end portion  277   a  that is connected to support member  258  by a connector  280  (FIG.  31 ), a free end portion  277   b  and a yieldably deformable, outwardly curved central portion  277   c . As indicated in FIG. 31, when the headrest assembly of the invention is fully assembled, central portion  277   c  of the spring is in pressural engagement with the front surface, or face,  264   a  of guide  264 . More particularly, when the headrest assembly  260  is interconnected with seat connector member  258  in the manner shown in FIG. 31, spring member  277  will be yieldably deformed in the manner shown in FIG. 31 so that central portion  277   c  is brought into pressural engagement with face  264   a  of the elongated guide  264 . With this construction, as the headrest assembly is moved upwardly and downwardly in the manner indicated in FIG. 28, spring  277  will yieldably resist sliding movement of headrest assembly  260  relative to elongated guide  264  and seat connector member  258 . In the preferred form of the invention a plastic film  279  is disposed between the central portion  277   c  and the face  264   a  of elongated guide  264  so as to insure smooth sliding of the headrest assembly relative to the connector member. 
     Having now described the invention in detail in accordance with the requirements of the patent statutes, those skilled in this art will have no difficulty in making changes and modifications in the individual parts or their relative assembly in order to meet specific requirements or conditions. Such changes and modifications may be made without departing from the scope and spirit of the invention, as set forth in the following claims.