Abstract:
A reclining chair includes a seat, a backrest, and a pair of spaced apart recliner mechanisms cooperatively supporting the seat and backrest. Each of the mechanisms includes a ground engaging base link, a seat link operably coupled with and supporting the seat, a backrest linkage operably coupling the backrest to the seat link, a rear swing link operably coupled to the base link at a first pivot, and a front swing link operably coupled to the base link with a shiftable pivot mechanism defining a second pivot. The rear swing link and the front swing link are selectively pivotable about the first and second pivots respectively to enable the mechanism to be selectively shifted between an upright position and a reclined position. The shiftable pivot mechanism shifts a position of the second pivot relative to the base link as the mechanism shifts between the first position and the second position.

Description:
RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 60/894,138 entitled ZERO CLEARANCE RECLINER MECHANISM filed Mar. 9, 2007, said application hereby fully incorporated herein by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates to reclining chair mechanisms and more specifically to zero-clearance reclining chair mechanisms. 
       BACKGROUND OF THE INVENTION 
       [0003]    Reclining chairs have become a very popular furniture item in today&#39;s home. Modern reclining chairs generally define three discrete seating positions: (1) an upright position in which the back is generally proximate a perpendicular orientation relative to the seat and the ottoman (if the chair is so equipped) is retracted; (2) a “TV” position in which the ottoman is extended, but the back is still more or less upright relative to the seat; and (3) a fully reclined position in which the ottoman is extended and the back is inclined at a greater angle relative to the seat. 
         [0004]    A drawback of standard reclining chairs, however, is that they must be positioned at some distance from the wall of a room because the top of the backrest tilts in a rearward direction when the chair is reclined. Prior attempts have been made to address this rear clearance problem existing with standard reclining chairs. These attempts have resulted in a general class of recliner mechanisms known as “zero-clearance” mechanisms, wherein linkages or other elements are arranged so that the lower edge of the backrest and the chair seat shifts forward relative to the floor as the mechanism is reclined, thereby enabling a lesser rearward shift of the top edge of the backrest. Examples of such prior mechanisms are disclosed in U.S. Pat. Nos. 4,740,031; 5,011,220; 5,570,927; 5,588,710; 5,772,278 and 5,217,276, all hereby incorporated herein by reference. 
         [0005]    One type of zero-clearance mechanism generally includes a four-bar linkage, wherein a pair of spaced apart swing links are pivoted on a base at one end of each link and pivoted to a seat link at the other ends. As the chair is reclined from the upright position in which the seat link is positioned over the base, the swing links pivot about their connections with the base to shift the seat link forwardly relative to the base. This in turn shifts the entirety of the backrest forwardly, away from any wall that may be behind the chair. These linkage based mechanisms are popular and in widespread use due to their low cost and relative ease of manufacture. 
         [0006]    It is usually desirable for user comfort purposes, however, for the seat to slope rearwardly toward the backrest of the chair. This is typically implemented in the linkage based mechanisms by making the front swing link longer than the rear swing link. A consequence, however, is that a user sitting in the chair is usually forced to work against the mechanism to shift the chair from the upright to the reclined positions and vice versa, particularly immediately proximate the upright position. The difference in length between the front and rear swing links cannot be made too great without resulting in excessively high user effort to operate the chair. Since the degree of forward shifting of the seat and backrest depends at least in part on the length of the swing links, the extent to which such a mechanism can approach true “zero-clearance” is limited. As a result, prior linkage type zero-clearance mechanisms still generally require some degree of rear clearance behind the backrest, because the top of the backrest still shifts rearwardly to some degree when the chair is reclined. 
         [0007]    Hence, what is still needed in the industry is a low cost, easy to operate recliner chair that enables less rear clearance than known “zero-clearance” mechanisms. 
       SUMMARY OF THE INVENTION 
       [0008]    The mechanism of the present invention addresses the need of the industry for a low cost, easy to operate recliner chair that enables less rear clearance than known “zero-clearance” mechanisms. In an embodiment of the invention, a reclining chair includes a seat, a backrest, and a pair of spaced apart recliner mechanisms cooperatively supporting the seat and backrest. Each of the mechanisms includes a ground engaging base link, a seat link operably coupled with and supporting the seat, a backrest linkage operably coupling the backrest to the seat link, a rear swing link operably coupled to the base link at a first pivot, and a front swing link operably coupled to the base link with a shiftable pivot mechanism defining a second pivot. The rear swing link and the front swing link are operably coupled to the seat link and the backrest linkage. The rear swing link and the front swing link are selectively pivotable about the first and second pivots respectively to enable the mechanism to be selectively shifted between an upright position in which the seat is disposed in a first position relative to the base link and the backrest defines a first angle relative to the seat, and a reclined position in which the seat is disposed in a second position forward of the first position relative to the base link and the backrest defines a second angle greater than the first angle relative to the seat. The shiftable pivot mechanism shifts a position of the second pivot relative to the base link as the mechanism shifts between the first position and the second position. 
         [0009]    In an embodiment, the shiftable pivot mechanism includes a follower post on the front swing link and a slot defined in the base link, wherein the follower post is received and slidably shiftable in the slot. In a further embodiment, the shiftable pivot mechanism may be a linkage operably coupling the front link and the base link. The chair may further be positionable in a third position, corresponding to a “TV” position, intermediate the first position and the second positions. 
         [0010]    A mechanism according to embodiments of the invention may include an ottoman linkage operably coupled to the seat link, wherein the ottoman linkage is selectively shiftable between a retracted position corresponding with the upright position of the mechanism, and an extended position corresponding with the reclined position of the mechanism. A drive linkage operably coupled with the ottoman linkage may be provided for selectively shifting the ottoman linkage between the retracted position and the extended position. 
         [0011]    An embodiment of a chair according to the invention may include a seat, a backrest, and a pair of spaced apart recliner mechanisms cooperatively supporting the seat and backrest. Each mechanism includes a ground engaging base link, a seat link operably coupled with and supporting the seat, a backrest linkage operably coupling the backrest to the seat link, a rear swing link operably coupled to the base link at a first pivot, a front swing link, and means for pivotally coupling the front swing link to the base link. The means may include means for defining a second pivot about which the front swing link is selectively pivotable, and means for shifting a position of the second pivot relative to the base link. The rear swing link and the front swing link are operably coupled to the seat link and the backrest linkage, wherein the rear swing link and the front swing link are selectively pivotable about the first and second pivots respectively to enable the mechanism to be selectively shifted between an upright position in which the seat is disposed in a first position relative to the base link and the backrest defines a first angle relative to the seat, and a reclined position in which the seat is disposed in a second position forward of the first position relative to the base link and the backrest defines a second angle greater than the first angle relative to the seat, and wherein the position of the second pivot is shifted relative to the base link as the mechanism shifts between the first position and the second position. 
         [0012]    In an embodiment, the means for defining a second pivot about which the front swing link is selectively pivotable may include a follower post on the front swing link, and the means for shifting a position of the second pivot may include a slot defined in the base link, the follower post received and slidably shiftable in the slot. In a further embodiment, the means for defining a second pivot about which the front swing link is selectively pivotable and the means for shifting a position of the second pivot may include a crank or other linkage pivotally coupled to the base link and the front swing link. 
         [0013]    A zero-clearance mechanism for a reclining chair according to an embodiment of the invention includes a ground engaging base link, a seat link, a backrest linkage comprising a backrest bracket, a rear swing link operably coupled to the base link at a first pivot, and a front swing link operably coupled to the base link with a shiftable pivot mechanism defining a second pivot. The rear swing link and the front swing link are operably coupled to the seat link and the backrest linkage, wherein the rear swing link and the front swing link are selectively pivotable about the first and second pivots respectively to enable the mechanism to be selectively shifted between an upright position in which the seat link is disposed in a first position relative to the base link and the backrest bracket defines a first angle relative to the seat, and a reclined position in which the seat link is disposed in a second position forward of the first position relative to the base link and the backrest bracket defines a second angle greater than the first angle relative to the seat link, The shiftable pivot mechanism shifts a position of the second pivot relative to the base link as the mechanism shifts between the first position and the second position. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0014]      FIG. 1  is a perspective view of a recliner mechanism according to an embodiment of the invention; 
           [0015]      FIG. 1   a  is a perspective view of a recliner chair according to an embodiment of the invention; 
           [0016]      FIG. 2  is a top plan view of the recliner mechanism of  FIG. 1 ; 
           [0017]      FIG. 3  is a front elevation view of the recliner mechanism of  FIG. 1 ; 
           [0018]      FIG. 4  is a side elevation view of the recliner mechanism of  FIG. 1 ; 
           [0019]      FIG. 5  is an inside elevation view of a linkage of the recliner mechanism of  FIG. 1 , positioned in an upright position; 
           [0020]      FIG. 6  is an outside elevation view of a linkage of the recliner mechanism of  FIG. 1 , positioned in an upright position; 
           [0021]      FIG. 7  is an inside elevation view of a linkage of the recliner mechanism of  FIG. 1 , positioned in a TV position; 
           [0022]      FIG. 8  is an outside elevation view of a linkage of the recliner mechanism of  FIG. 1 , positioned in a TV position; 
           [0023]      FIG. 9  is an inside elevation view of a linkage of the recliner mechanism of  FIG. 1 , positioned in a fully reclined position; 
           [0024]      FIG. 10  is an outside elevation view of a linkage of the recliner mechanism of  FIG. 1 , positioned in a fully reclined position; 
           [0025]      FIG. 11  is an elevation view of the ottoman mechanism of the recliner mechanism; 
           [0026]      FIG. 12  is a fragmentary inside view of the bottom end of the front swing link of a linkage of the recliner mechanism of  FIG. 1 , positioned in an upright position; 
           [0027]      FIG. 13  is a fragmentary outside view of the bottom end of the front swing link of a linkage of the recliner mechanism of  FIG. 1 , positioned in an upright position; 
           [0028]      FIG. 14  is a fragmentary inside view of the bottom end of the front swing link of a linkage of the recliner mechanism of  FIG. 1 , positioned in a TV position; 
           [0029]      FIG. 15  is a fragmentary outside view of the bottom end of the front swing link of a linkage of the recliner mechanism of  FIG. 1 , positioned in a TV position; 
           [0030]      FIG. 16  is a fragmentary inside view of the bottom end of the front swing link of a linkage of the recliner mechanism of  FIG. 1 , positioned in a fully reclined position; 
           [0031]      FIG. 17  is a fragmentary outside view of the bottom end of the front swing link of a linkage of the recliner mechanism of  FIG. 1 , positioned in a fully reclined position; 
           [0032]      FIG. 18  is a fragmentary inside view of the bottom end of a front swing link of a linkage of a recliner mechanism according to an alternative embodiment of the invention, positioned in an upright position; 
           [0033]      FIG. 19  is a fragmentary inside view of the bottom end of the front swing link of the embodiment of  FIG. 18 , positioned in a TV position; 
           [0034]      FIG. 20  is a fragmentary inside view of the bottom end of the front swing link of the embodiment of  FIG. 18 , positioned in a fully reclined position; and 
           [0035]      FIG. 21  is an top view of the linkage coupling the base link and front swing link of the embodiment of  FIG. 18 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0036]    As depicted in  FIGS. 1 and 1   a , zero-clearance recliner chair  38  generally includes seat  40 , backrest  42 , arms  44 ,  46 , and ottoman  48 , all operably coupled with mechanism  50 . Mechanism  50  generally includes a pair of linkages  52 ,  54 , seat box  56 , cross-bracing  58 , and crankshaft  60 . Linkages  52 ,  54 , are mirror images of each other and have identical structure and function. As a result, the description provided herein below for linkage  52  should be assumed to apply also to linkage  54 . 
         [0037]    Linkage  52  generally includes ground-engaging base link  62 , front swing link  64 , rear swing link  66 , seat link  68 , lower coordinating linkage  70 , ottoman linkage  72 , upper coordinating linkage  74 , drive linkage  76 , and backrest linkage  78 . Rear swing link  66  is pivotally connected to base link  62  at pivot  80  and to bell crank  82  of lower coordinating linkage  70  at pivot  84 . Front swing link  64  is pivotally connected to upper link  86  of upper coordinating linkage  74  at pivot  88 . Front swing link  64  is coupled to base link  62  with follower post  90  slidably disposed in slot  92 . Bottom end  94  of front swing link  64  has offset portions  96 ,  98 , on either side of longitudinal axis  100 , with follower post  90  disposed on offset portion  96  so as to be offset from longitudinal axis  100 . Bottom edge  102  of front swing link  64  has rounded corner  104  at the rear. 
         [0038]    Lower coordinating linkage  70 , in addition to bell crank  82 , generally includes front link  106  and tie bar  108 . Bell crank  82  is pivotally connected to lower extension  110  of seat link  68  at pivot  112 . Rear end  114  of tie bar  108  is pivotally connected to bell crank  82  at pivot  116 . Front link  106  is pivotally connected to seat link  68  at pivot  118  and to front swing link  64  at pivot  120 . Front end  122  of tie bar  108  is pivotally connected at pivot  124  to front link  106  intermediate pivots  118 ,  120 . 
         [0039]    Upper coordinating linkage  74 , in addition to upper link  86 , generally includes crank  126  and tie bar  128 . Crank  126  is pivotally connected to seat link  68  at pivot  130 . Rear end  132  of upper link  86  is pivotally connected to crank  126  at pivot  134 . Rear end  135  of tie bar  128  is pivotally connected to crank  126  at pivot  136 , while front end  138  is connected to lower inside ottoman link  139  at pivot  140 . 
         [0040]    Ottoman linkage  72 , which links ottoman cushion  72   a  to the chair, in addition to lower inside ottoman link  139 , generally includes upper inside ottoman link  142 , lower intermediate link  144 , upper intermediate link  146 , lower outside link  148 , outer ottoman flange  150 , and inner ottoman link  152 . Lower inside ottoman link  139  is pivotally coupled to seat link  68  at pivot  154  and to upper intermediate link  146  at pivot  156 . Upper inside ottoman link  142  is pivotally connected to seat link  68  at pivot  158 , to upper intermediate link  146  at pivot  160 , and to lower intermediate link  144  at pivot  162 . Upper intermediate link  146  is pivotally connected to outer ottoman flange  150  at pivot  164  and lower intermediate link  144  is pivotally connected to outer ottoman flange  150  at pivot  166 . Lower outside link  148  is pivotally connected to outer ottoman flange  150  at pivot  168  and to inner ottoman link  152  at pivot  170 . Inner ottoman link  152  is pivotally connected to upper intermediate link  144  at pivot  172 . 
         [0041]    Backrest linkage  78 , which links backrest cushion assembly  78   a  to the chair, generally includes yolk  174  and connecting link  176 . Yolk  174  is pivotally connected to upper projecting portion  178  of seat link  68  at pivot  180 , and to connecting link  176  at pivot  182 . Lower end  184  of connecting link  176  is pivotally connected to bell crank  82  at pivot  186 . 
         [0042]    Drive linkage  76  generally includes crank  188  and connecting rod  190 . Connecting rod  190  is pivotally connected to lower inside ottoman link  139  at pivot  192  and to crank  188  at pivot  194 . Crank  188  defines aperture  196  for receiving crankshaft  60  therethough, and is rotationally fixed to crankshaft  60  with fastener  198 . Bushing  199  extends through seat link  68  and rotationally receives crankshaft  60 . Drive spring  200  extends between flange  202  on seat link  68  and slot  204  on connecting rod  190 . 
         [0043]    Seat box  56 , which supports seat cushion assembly  56   a , generally includes outer frame  250  which has a plurality of support wires  252  extending between front and back rails  254 ,  256 , and side rails,  258 ,  260 . Seat box  56  is fastened to seat link  68  at flanges  262 ,  264 . Cross-bracing  58  extends between opposing flanges  266  on front swing links  64  of each linkage  52 ,  54 , and opposing flanges  268  on rear swing links  66  of each linkage  52 ,  54 , to complete the assembly of recliner mechanism  50 . 
         [0044]    In use, recliner mechanism  50  is selectively positionable in three discrete positions: (1) an upright position with ottoman retracted at depicted in  FIGS. 1-6 ; (2) a “TV” position in which the ottoman is extended but the backrest remains upright at depicted in  FIGS. 7-8 ; and (3) a fully reclined position in which the backrest is folded down and the ottoman is raised as depicted in  FIGS. 9-10 . In the upright position as depicted in  FIGS. 1-6 , crank  188  extends rearwardly on a line from crankshaft  60  that is slightly above a line extending along drive spring  200  such that drive linkage  76  is slightly “overcenter” and is held in position by the tension of drive spring  200 . Trigger release mechanism  206  is operably coupled to a release lever located between an arm of the recliner and the seat cushion, or to any other release control as may be known in the recliner art. In the upright position, as depicted in  FIGS. 12-13 , follower post  90  is disposed in the upper end of slot  92  and bottom edge  102  of front swing link  64  proximate rounded corner  104  rests on bottom flange  208  of base link  62 . A pad  209  made from elastomeric material may be interposed between bottom edge  102  and bottom flange  208  to prevent metal-to-metal contact. 
         [0045]    Upon activation of the release lever, crank  188  and crankshaft  60  rotate in the direction of the arrow as depicted in  FIG. 7 . Once crank  188  passes through center, drive spring  200  pulls connecting rod  190  forward, driving ottoman linkage  72  to extend. Front swing link  64  and rear swing link  66  rotate forward slightly, causing bottom edge  102  of front swing link  64  to rock on bottom flange  208  so that rounded front edge  210  is resting on bottom flange  208  is depicted in  FIGS. 14-15 . Follower  90 , in turn, slides upwardly in slot  92 . The rocking motion of bottom edge  102  of front swing link  64  enables the lower pivot point about which front swing link rotates relative to base link  62  to shift forward slightly, thereby enabling the backrest to shift forward slightly in turn. 
         [0046]    In the embodiment depicted in  FIGS. 1-17 , slot  92  enables about 3/16 inch of vertical sliding movement of follower post  90 . It will, however, be appreciated that the range of movement of follower post  90  may range between about 1/32 inch to 2 or more inches in embodiments of the invention. 
         [0047]    As the recliner is shifted from the “TV” position depicted in  FIGS. 7-8  and  FIGS. 14-15 , to the fully reclined position depicted in  FIGS. 9-10  and  FIGS. 16-17 , seat link  68  shifts forwardly as enabled by lower coordinating linkage  70  and upper coordinating linkage  74 . Bottom edge  102  rocks further forward along rounded front edge  210  as front swing link  64  pivots about follower post  90 . 
         [0048]    From the above description, it will be appreciated that the rocking motion of bottom edge  102  of front swing link  64  on bottom flange  208  enables the mechanism to shift forwardly by a greater degree with less user effort than prior zero-clearance mechanisms upon reclining, thereby reducing or eliminating any rearward movement of the top edge of the backrest and enabling the chair to be placed nearer the wall. It will be appreciated by those of ordinary skill that, in accordance with the invention, follower post  90  and slot  92  may be replaced by other mechanism elements enabling similar movement such as a bell crank or other linkage. 
         [0049]    For instance, in an embodiment depicted in  FIGS. 18-21 , front swing link  64  is pivotally coupled to intermediate link  300  at pivot  302 . Intermediate link  300  is, in turn, pivotally coupled to base link  62  at pivot  304 . Again, bottom end  94  of front swing link  64  has offset portions  96 ,  98 , on either side of longitudinal axis  100 , with pivot  302  disposed on offset portion  96  so as to be offset from longitudinal axis  100 . Bottom edge  102  of front swing link  64  has rounded corner  104  at the rear. 
         [0050]    In use, rounded corner  104  rests bottom flange  208  when the chair is positioned in the upright position. As the chair is shifted from the upright position toward the reclined position, front swing link  64  pivots about pivot  302  relative to intermediate link  300 . Bottom edge  102  of front swing link  64  rocks on bottom flange  208 , shifting rounded corner  104  upward. Intermediate link  300  pivots about pivot  304  enabling pivot  302  to shift vertically as front swing link  64  rocks. 
         [0051]    It will be appreciated by those of skill in the art that shifting of the pivotal coupling point between front swing link  64  and base link  62  may also be accomplished by mechanical linkages and connections of a variety of other configurations, all within the scope of the present invention. Accordingly, since the present invention may be embodied in other specific forms without departing from the spirit of the essential attributes thereof; the depicted embodiments should be considered in all respects as illustrative and not restrictive, reference being made to the appended claims rather than to the foregoing description to indicate the scope of the invention.