Patent Publication Number: US-6904628-B2

Title: Convertible sofa-bed

Description:
This application claims the benefit of provisional application 60/329,021 filed on Oct. 12, 2001. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to a sofa that is convertible into a bed, and relates more specifically to a sofa that has backrest and seat sections that form portions of the bed. 
     BACKGROUND OF THE INVENTION 
     Convertible sofa beds are popular with consumers because of their multifunctionality. Many consumers find it very convenient to have a sofa that can provide a bed for a guest, as such a sofa can eliminate the need for an additional, separate bed. One popular sofa-bed design includes its own complete mattress that is folded within the cavity of the sofa during periods of non-use. One such example is illustrated in U.S. Pat. No. 4,200,941 to Gill et al. This type of sofa-bed can be quite heavy, and typically requires not only the separate mattress, but also a relatively intricate mechanism to control the unfolding and folding of the mattress. 
     Other sofa beds lack a complete mattress, instead being constructed of separate sections that serve as support surfaces of the sofa and unfold to form a flat, mattress-like sleeping surface. An example of a convertible sofa of this type is illustrated in U.S. Pat. No. 4,737,996 to Tiffany. The Tiffany sofa-bed includes a backrest, a seat and a “subseat” that unfold to form the horizontal sleeping surface. In the folded “sofa” configuration, the backrest is generally upright, and the seat and “subseat” fold upon each other (with the subseat in an inverted position). The backrest is guided between positions by preformed slots in the arms of the sofa that receive posts that extend laterally from the backrest. The backrest is coupled to the seat and subseat via an angled link. The subseat is pivotally attached at one end to the arms and is hinged at the other end to the seat. This arrangement is described in Tiffany as being particularly economical and having relatively few moving parts. It would be desirable to provide an improved version of this configuration (particularly one that provides a bed at a “standard” height of between about 18 and 26 inches) to capitalize on these advantages. 
     In addition, the Tiffany-style sofa-bed employs the backrest of the sofa-bed as the head end of the unfolded bed. Because the backrest section is required to pivot when moving between positions, it is not fixed to the arms of the sofa. As such, there are typically small gaps between the outer edges of the backrest and the arms that can be unsightly. It would be desirable to provide a Tiffany-style sofa-bed that lacks these gaps between the backrest and the arms. 
     Moreover, the Tiffany-style sofa employs sections of cushions and panels that can be rather heavy and, therefore, difficult to move between positions. It would be desirable to provide a Tiffany-style sofa-bed that moves easily between the unfolded and folded positions. 
     SUMMARY OF THE INVENTION 
     The present invention is directed to a sofa-bed having a movable backrest, seat and subseat that can unfold to form a bed of conventional bed height. The sofa-bed comprises: a frame with opposing arms, a backrest operatively connected with the frame such that the backrest can pivot and slide relative to the frame; a seat; a subseat hinged to the seat; a connecting rod that pivotally interconnects the subseat and the backrest; pairs of center legs and end legs pivotally attached to, respectively, the subseat and seat; and mechanisms for folding and unfolding the center and end legs. The sofa-bed is movable between a folded position, in which the backrest is generally upright, the seat is generally horizontal, and the subseat is generally horizontal and positioned beneath the seat in a first inverted orientation, and an unfolded position, in which the backrest, subseat and seat are generally horizontal, and the subseat is positioned between the backrest and the seat in a second non-inverted orientation. The mechanisms for the center legs and the end legs are configured to move the legs from a generally horizontal folded position between the seat and subseat when the sofa-bed is in the folded position to a generally upright position beneath, respectively, the subseat and seat when the bed is in the unfolded position. In this configuration, the sofa-bed, when unfolded, can provide a bed of conventional height. 
     The sofa-bed of the present invention may optionally include, in some embodiments, a balance mechanism that assists the user in folding and unfolding the sofa-bed. In one embodiment, the balance mechanism is attached to the subseat and the arm and includes a spring that can supply tension to the mechanism such that the both unfolding and folding are facilitated. 
     The sofa-bed of the present invention may also include, in other embodiments, a back panel that is fixed to and extends between the arms. In these embodiments, the backrest, seat and subseat move and are connected in the manner described above. In certain embodiments, the back panel includes a recess within which the backrest nests in the folded position. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         FIG. 1  is a cutaway side view of the sofa-bed of the present invention shown in its folded position. 
         FIG. 2  is a cutaway side view of the sofa-bed of  FIG. 1  shown in an intermediate position between the folded and unfolded positions. 
         FIG. 3  is a cutaway side view of the sofa-bed of  FIG. 1  in the unfolded position. 
         FIG. 4  is a partial top view of the center and end leg mechanisms of the sofa-bed of  FIG. 1  in their folded positions. 
         FIG. 5  is a partial side view of the center and end leg mechanisms of the sofa-bed of  FIG. 1  in their folded positions. 
         FIG. 6  is a cutaway perspective view of the center and end leg mechanisms of the sofa-bed of  FIG. 1  in their unfolded positions. 
         FIG. 7A  is a cutaway perspective view of the balancing mechanism (without the spring) and the connecting link of the sofa-bed of  FIG. 1  in their unfolded positions. 
         FIG. 7B  is a side view of the balancing mechanism of  FIG. 7A  shown in its folded position. 
         FIG. 7C  is a side view of the balancing mechanism of  FIG. 7A  shown in its unfolded position. 
         FIG. 8  is a rear perspective view of an alternative embodiment of a sofa-bed of the present invention. 
         FIG. 9  is a front perspective view of the sofa-bed of  FIG. 8  with the backrest cushion removed and the bed in the folded position. 
         FIGS. 10-13  are front perspective views of the sofa-bed of  FIG. 8  as it moves from the folded position to the unfolded position. 
         FIGS. 14A-14D  are side views of the sofa-bed of  FIG. 8  moving from a partially unfolded position to the folded position, wherein the draping of a sheet covering the mattress can be seen. 
         FIG. 15A  is a side view of another embodiment of a sofa-bed of the present invention, with the sofa-bed shown in the unfolded position. 
         FIG. 15B  is a partial side view of the sofa-bed of  FIG. 15A  showing the backrest in the folded position. 
         FIG. 16  is a schematic side view of another embodiment of a sofa-bed of the present invention shown in the folded position. 
         FIG. 17  is a schematic side view of the sofa-bed of  FIG. 16  in an intermediate position between the folded and unfolded positions. 
         FIG. 18  is a schematic side view of the sofa-bed of  FIG. 16  in the unfolded position, with the subseat and seat cushions in a stacked relationship. 
         FIG. 19  is a schematic side view of the sofa-bed of  FIG. 16  in the unfolded position with the subseat and seat cushions in an outspread relationship. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention will be described more particularly hereinafter with reference to the accompanying drawings. The invention is not intended to be limited to the illustrated embodiments; rather, these embodiments are intended to fully and completely disclose the invention to those skilled in this art. Like numbers refer to like components throughout, and certain dimensions and thicknesses may be exaggerated for clarity. 
     Referring now to  FIGS. 1-3 , a convertible sofa-bed, designated broadly at  20 , is illustrated herein. The sofa-bed  20  includes a pair of generally upright rectangular arms  22 , a backrest  40 , a subseat  62 , and a seat  90 . Each of the backrest  40 , subseat  62  and seat  90  includes a flat panel (designated at  40   a ,  62   a  and  90   a , respectively) and an upholstered cushion (designated at  41 ,  63  and  91 , respectively, and usually formed of a medium to high density foam) releasably (via a zipper or the like) or permanently fixed thereto (in many embodiments, a removable cushion (not shown) overlies the seat cushion  91  and is removed prior to the unfolding of the sofa-bed  20 ). These parts are interconnected with a pair of connecting links  54  and a hinge  92  such that they can be converted from the sofa configuration illustrated in  FIG. 1  to the bed configuration illustrated in FIG.  3 . 
     The sofa bed  20  is essentially a pair of mirror images about a vertical plane P (see  FIGS. 6 and 7 ) that extends through the center of the backrest  40 , the subseat  62 , and the seat  90  equidistant between the arms  22 . As such, except where indicated, only the structures on one side of the sofa-bed  20  is described herein in detail; those skilled in this art will understand that this description is equally applicable to the mirror image structures on the opposite side of the sofa-bed  20 . 
     In addition, as used herein the terms “lateral”, “outward” and derivatives thereof indicate the directions defined by a vector beginning at the aforementioned plane P and extending normal thereto. Conversely, the terms “inward”, “inboard” and derivatives thereof indicate the direction opposite the “outward” direction. Together, the “inward” and “outward” directions comprise the “transverse” axis of the sofa-bed  20 . The “rear” of the unfolded sofa-bed  20  is located at the end of the sofa-bed  20  nearest the backrest  40 , and the “front” of the sofa-bed  20  is located at the end opposite the backrest  40 . The “front” and “rear” directions comprise the “longitudinal” axis of the sofa-bed  20 . The “head” of the unfolded sofa-bed  20  is the end formed by the backrest  40 , and the “foot” of the unfolded sofa-bed  20  is the end formed by the seat  90 . 
     In addition, some components of the sofa-bed  20  are illustrated herein as a series of pivotally interconnected links. Those skilled in this art will appreciate that the pivots between links can take a variety of configurations, such as pivot pins, rivets, bolt and nut combinations, and the like, any of which may be suitable for use with the present invention. Also, the shapes and configurations of the links themselves may vary as understood by those skilled in this art. 
     Returning to the drawings, and referring again to  FIGS. 1-3 , the arms  22  are interconnected with a transversely-extending rear rail  24  and a transversely-extending front rail  26 . With these rails  24 ,  26 , the arms  22  form a box-like frame  21  for the sofa  20 . Each arm  22  includes a lower slot  28 , which extends from a lower rear corner of the arm  22  and extends forwardly and upwardly in a smoothly curving manner to terminate in an upper forward portion of the arm  22 . The lower slot  28  includes a generally horizontal segment  28   a , an upwardly and forwardly extending segment  28   b , and a short forwardly and slightly upwardly extending segment  28   c . The segments  28   a ,  28   b ,  28   c  merge smoothly to form of the lower slot  28 . Each arm  22  also includes an upper slot  30  that extends between the upper rear corner of the arm  22  forwardly to terminate at a generally central, upper location in the arm  22 . The upper slot  30  comprises a horizontal segment  30   a  and a slightly upwardly sloping segment  30   b  that merges smoothly with the horizontal segment  30   a . The lower and upper slots  28 ,  30  may be lined with protective components, such as plastic shields (not shown). 
     Referring again to  FIGS. 1-3 , the backrest  40  includes a backrest bracket  42  at each of its lateral edges. An upper post  44  extends laterally from each backrest bracket  42  and fits within the upper slot  30  of its respective arm  22 . Similarly, a lower post  46  extends laterally from each backrest bracket  42  to fit within the slot  28  of its respective arm  22 . The upper and lower posts  44 ,  46  are sized and configured to slide within and pivot relative to, respectively, the upper and lower slots  30 ,  28 . An optional elastic strap  43  or other biasing member extends between the rear rail  24  and the lower portion of the backrest panel  40   a.    
     In the interest of clarity, the interconnection of the backrest  40 , subseat  62  and seat  90  will be described in the unfolded position shown in FIG.  3 . As shown in  FIG. 3 , a subseat bracket  58  is mounted to the panel  62   a  of the subseat  62  opposite the cushion  63 . The subseat bracket  58  is then pivotally mounted to the inboard surface of the arm  22  via a subseat mounting bracket  64  at a pivot  66  located on a downwardly-extending tab  59  on the subseat bracket  58 . The subseat bracket  58  includes a stop pin  58   a  that extends inwardly therefrom. The subset mounting bracket  64  also has an inwardly extending tab  64   a . The subseat  62  is directly connected to the backrest  40  with a generally straight connecting link  54 . The connecting link  54  is pivotally connected with the backrest bracket  42  at a pivot  56  located between the upper and lower posts  44 ,  46  and at its opposite end to the subseat bracket  58  at a pivot  60  located at a front portion of the subseat bracket  58 . 
     Still referring to FIG.  3  and also referring to  FIG. 6 , the seat  90  is pivotally interconnected with the subseat  62  at a hinge  92 . The hinge  92  includes three pairs of subseat plates  94  and seat plates  100  that are spaced transversely across the sofa-bed  20 . Each subseat plate  94  includes a horizontal panel  96  and a vertical panel  98 ; similarly, the seat plates  100  include a horizontal panel  102 , and a vertical panel  104 . Each of the subseat plates  94  is pivotally interconnected with its respective seat plate  100  at a pivot  106  that is located in and attaches the vertical panels  98 ,  104 . 
     To move the sofa bed  20  from the unfolded position of  FIG. 3  to the folded position of  FIG. 1 , the operator lifts the foot end of the seat  90 . This action causes the seat  90  to rise, which in turn causes the subseat  62  to rotate upwardly and rearwardly about the pivot  66  (counterclockwise from the vantage point of FIG.  3 ). This action also causes the seat  90  and subseat  62  to rotate relative to one another about the pivot  106 . This action continues (see  FIG. 2  for an intermediate position) until the subseat  62  is inverted and underlies the seat  90  in the manner shown in FIG.  1 . 
     Moreover, as the subseat  62  rotates, its rotation drives the connecting link  54  rearwardly. This motion forces the backrest  40  rearwardly (in the unfolded position, both the upper and lower posts  44 ,  46  are completely forward in their respective slots  30 ,  28 ) and causes it to rotate (clockwise from the vantage point of FIG.  3 ), with its motion defined by the movement of the upper and lower posts  44 ,  46  within the upper and lower slots  30 ,  28 . The elastic strap  43  remains in tension, with the result that the lower portion of the backrest  40  is biased toward the folded position (this biasing can help to provide smooth movement of the backrest  40  within the slots  28 ,  30 ). Movement of the sofa-bed  20  to the folded position ceases when the upper and lower posts  44 ,  46  reach the rearwardmost points of the upper and lower slots  30 ,  28 . At this point, the subseat  62  is completely inverted and underlies the seat  90  with the cushion  63  facing downwardly. The seat  90  remains generally horizontal, with its cushion  91  facing upwardly. 
     To move the folded sofa-bed  20  back to the unfolded position of  FIG. 3 , the operator can lift on the front edge of the seat  90 . Doing so causes the subseat  62  to rotate about the pivot  66  and to move forwardly. The movement of the subseat  62  draws the connecting link  54 , and in turn the backrest  40 , forwardly, with the backrest  40  also rotating as allowed by the upper and lower slots  30 ,  28 . 
     Those skilled in this art will appreciate that, although the illustrated slots and posts are preferred for controlling the movement of the backrest  40 , other mechanisms and structures for operatively connecting the backrest  40  and the frame  22 , such as pivoting four-bar linkage mechanisms and the like, may also be employed with sofa-beds of the present invention. Also, the interconnection between the backrest  40 , subseat  62  and seat  90  may take forms other than the direct interconnection provided by the connecting link  54 . 
     Referring again to FIG.  3  and also to  FIGS. 7A-7C , a balance mechanism  70  is interconnected with the subseat  62  to provide assistance in the folding and unfolding of the sofa bed  20 , as some of the components can be quite heavy. The balance mechanism  70  includes an L-shaped drawing link  72 , which is pivotally interconnected at one end to the subseat bracket  58  at a pivot  74  near the subseat mounting bracket  64 ; at its opposite end, the drawing link  72  is pivotally interconnected to one end of a L-shaped crank  76  at a pivot  78 . At its vertex, the drawing link  72  has an inwardly-extending stop pin  72   a . The crank  76  is pivotally interconnected at its vertex to the subseat mounting bracket  64  at a pivot  80 . The opposite end of the crank  76  includes a transversely-extending pin  84 . A spring  82  is attached at one end to the pin  84  and is mounted to the arm  22  via a spring bracket  86  which includes a pin  88  that the spring  82  engages. 
     In the unfolded position illustrated in  FIGS. 3 ,  7 A and  7 C, the drawing link  72  extends rearwardly and slightly upwardly from the pivot  74  to its vertex, then downwardly and slightly rearwardly to the pivot  78 . The crank  76  extends downwardly from the pivot  78  to the pivot  80 , then rearwardly to attach to the forward end of the spring  82 . The spring  82  extends rearwardly and downwardly from the pin  84  to the pin  88  and is slightly in tension (preferably about 10 pounds of tension is provided by the combination of the springs  82  on each side of the sofa-bed  20 ). Notably, the pin  84 , the pivot  66 , and the pivot  74  form an “over-center” configuration, with the pivot  66  being positioned below a longitudinal axis defined by the spring  82 , such that the tension in the spring  82  urges the sofa-bed  20  to remain in the unfolded position and “locks” it therein. 
     As the sofa-bed  20  moves to the folded position of  FIGS. 1 and 7B , as described above, the subseat  62  is moving rearwardly and rotating to an inverted position. This movement of the subseat  62  drives the drawing link  72  rearwardly and causes the drawing link  72  to rotate counterclockwise. The movement and rotation of the drawing link  72  drives the crank  76  counterclockwise about the pivot  80 . Once the crank  76  rotates sufficiently that the “over-center” alignment of the pin  84 , the pivot  66 , and the pivot  74  has been overcome, its rotation induces the spring  82  to continue to stretch, thereby providing increasing resistance to the rotation of the subseat  62  (i.e., the spring  82  biases the seat  90  and subseat  62  toward the unfolded position). This resistance can help to control the lowering of the seat  90  and subseat  62  into the frame of the sofa-bed  20 , which may be desirable, as the seat  90  and subseat  62  can be quite heavy. In addition, the considerable tension in the spring  82  (preferably between about 120 and 160 pounds in the folded position, in which the spring  82  is stretched more than in the unfolded position) can also assist the operator in raising the seat  90  and subseat  62  from the frame to move the sofa-bed  20  into the unfolded position of FIG.  3 . Thus, the configuration of the balance mechanism  70  can provide assistance to unfolding while enabling the seat  90  and subseat  62  to remain in the folded position when unfolding is not desired. 
     It can also be seen that in the folded position of  FIG. 7B , the stop pin  72   a  contacts the underside of the subseat bracket  58 , the stop pin  58   a  contacts the upper edge of the drawing link  72 , and the tab  64   a  contacts the forward edge of the subseat bracket  58 . These interactions help to support the seat  90  and subseat  62  in the folded position, which can enable the sofa-bed  20  to operate without one or more lower support rails included in prior sofa-beds of this type. 
     Those skilled in this art will appreciate that the balance mechanism  70  may take other configurations. For example, the shapes of the links comprising the balance mechanism  70  may be modified, as may the number of links or their interconnection relationship. 
     It can also be seen that, in the unfolded position of  FIG. 3 , the subseat  62  and seat  90  are supported from below by legs  112 ,  132 . As can be seen in the folded position of FIG.  1  and in  FIGS. 4-6 , the legs  112 ,  132  fold into positions between the seat  90  and the subseat  62 . The movement of the legs  112 ,  132  is controlled by a center leg mechanism  110  and an end leg mechanism  130 , which together comprise a leg-folding mechanism  111 . These are described in detail below. 
     Referring to  FIGS. 3 and 6 , the center leg mechanism  110  includes a brace  118 , which is pivotally interconnected at one end to the vertical panel  104  of the seat plate  100  at a pivot  122  that is located forwardly of the pivot  106 , and at the other end at a pivot  120  to a flange  114  which extends upwardly from the leg  112 . The flange  114  terminates at a pivot  116  with the vertical panel  98  of the subseat plate  94 . Thus, a four-bar linkage is defined between the brace  118 , the flange  114 , the subseat plate  94 , and the seat plate  100 . The pivots  116 ,  106  and  122  are generally horizontally aligned when the sofa-bed  20  is in the unfolded position. 
     Still referring to  FIGS. 3 and 6 , the end leg mechanism  130  includes a flange  134  that extends upwardly from the leg  132 , a seat bracket  136  having a vertical panel  138  and a horizontal panel  140 , and a crank  150 . The horizontal panel  140  of the seat bracket supports the panel  90   a  of the seat  90  from underneath. The flange  134  is connected to the vertical panel  138  of the seat bracket  136  at a pivot  144 . The flange  134  includes an upwardly and rearwardly extending tab  146 , at which point it is interconnected with an upwardly and forwardly extending tab  152  of the crank  150  at a pivot  154  that is located just upwardly and rearwardly of the pivot  144 . The vertical panel  138  of the seat bracket  136  also includes a transversely-extending pin  142  that is positioned just forwardly of the front end of the flange  134 . A connecting tube  148  is fixed to the rearward end of the crank  150  and also is pivotally connected to the vertical panel  98  of the subseat plate  94  between the pivots  116 ,  106  at a pivot  168 . 
     Referring still to  FIGS. 3 and 6 , the legs  112  on either side of the sofa bed  20  are interconnected via a cross tube  160  (which extends between brackets  115  mounted to and extending transversely from an upper portion of each leg  112 ) and the legs  132  on either side of the bed are connected via a cross tube  162  (which extends between brackets  145  mounted to and extending transversely from an upper portion of each leg  132 ). The cross tubes  160 ,  162  assist in synchronizing the motion of the legs and in providing stability to the sofa-bed  20  when it is in the unfolded position. Also, the cross tube  160  and legs  112  may be formed as a unitary member from a single length of tubing; similarly, the cross tube  162  and legs  132  can be formed as a unitary member. 
     As noted above, to move the sofa bed  20  from the unfolded position of  FIG. 3  to the folded position of  FIG. 1 , the operator lifts on the foot end of the seat  90 . This action causes the seat  90  to rise, which in turn causes the subseat  62  to rotate upwardly and rearwardly about the pivot  66  and causes the seat  90  and subseat  62  to rotate relative to one another about the pivot  106 . As the relative rotation of the seat  90  and subseat  62  continues, the subseat plate  94  rotates with the subseat  62 . The action of the subseat plate  94  drives the lower end of the flange  114  forwardly and upwardly; also, the lower end of the brace  118  is driven upwardly and forwardly. The movement of the flange  114  draws the leg  112  from its generally upright orientation toward the underside of the seat  90 . This action is completed when the leg  112  folds completely under the seat  90  and is generally horizontally disposed and sandwiched between the seat  90  and subseat  62  (see FIGS.  4  and  5 ). 
     In addition, the pivoting of the subseat  62  relative to the seat  90  drives the connecting tube  148  and crank  150  forwardly toward the foot end of the seat  90 . This action causes the flange  134  to rotate about the pivot  144  such that the leg  132  moves from its generally upright orientation to collapse below the seat  90  in a generally horizontal disposition. This action continues until the subseat  62  is inverted and positioned below the seat  90  (see  FIGS. 1 ,  4  and  5 ). The center legs  112  and the end legs  132  define a substantially horizontal plane, with the end legs  132  being positioned inboard of the center legs  112 . 
     When the sofa-bed  20  is returned to the unfolded position, the movements described herein for the center leg mechanism  110  and the end leg mechanism  130  are reversed. Movement of the legs  112 ,  132  ceases when the forward edge of the flange  134  strikes the pin  142  (which should coincide with the upper and lower posts  44 ,  46  of the backrest  40  reaching the forward ends of the upper and lower slots  30 ,  28 . 
     Those skilled in this art will recognize that other leg mechanisms may also be suitable for use with sofa-beds of the present invention. For example, the shapes and pivot points of members thereof may be modified, or links may be added or omitted as desired. 
     Another embodiment of a sofa-bed of the present invention, designated broadly at  200 , is illustrated in  FIGS. 8-14D . The sofa-bed  200  includes a seat  290  and a subseat  262  that are substantially identical to the seat  90  and subseat  62  of the embodiment illustrated in  FIGS. 1-7 ; however, the sofa-bed  200  has a frame  202  that includes a back panel  203  that is fixed to the arms  204  and extends upwardly above the height of the arms  204  (typically at least 1 to 15 inches from the underlying surface). The back panel  203 , which typically has an upper edge that is higher than the arms  204 , includes a recess  206  in which the backrest  240  resides when the sofa-bed  200  is in the folded position (see FIG.  9 ). The sofa-bed  200  moves between the folded and unfolded positions in much the same manner as the sofa-bed  20  of  FIGS. 1-7  (see FIGS.  9 - 13 ). 
     Referring now to  FIGS. 14A-14D , the movement of the backrest  240  between the folded and unfolded positions is controlled by the movement of upper and lower posts  244 ,  246  within, respectively, upper and lower slots  230 ,  228  in the arms  204 . It should also be noted that, in the folded position (see FIG.  14 D), the backrest  240  is substantially vertical. Notably, the backrest cushion  241  includes a wedge-shaped section  241  a that is hinged (preferably with a cloth hinge) at its lower end to the remainder of the backrest cushion  241 . The wedge-shaped section  241   a  can pivot about its hinge from the position shown in  FIGS. 14A-C , in which it overlies the end of the backrest cushion  41  and forms a flat surface with the remainder of the backrest cushion  241 , to the position shown in  FIG. 14D , in which it has rotated approximately 180 degrees and forms a supporting lumbar structure just above and rearwardly of the seat  290 . 
     The inclusion of the back panel  203  can provide a more pleasing appearance from the rear of the sofa-bed  200  because no gaps exist between the back panel  203  and the arms  204 . While not only providing an improved appearance, the inclusion of the back panel  203  can also allow a sheet  275  to be left in place as the sofa-bed  200  is in the folded position (see FIGS.  8  and  14 A- 14 D) without detracting from the appearance of the sofa-bed  200 , as the sheet  275  would not be visible. 
     Referring now to  FIGS. 15A and 15B , another embodiment of a sofa-bed of the present invention is illustrated. The sofa-bed, designated broadly at  300 , includes a similar frame, subseat, and seat as the sofa-bed  200 . However, the arms  322  of the sofa-bed  300  include upper and lower slots  328 ,  330  that differ in configuration from the slots  28 ,  30  and  228 ,  230  of the embodiments of  FIGS. 1-14D . The upper slot  328  extends rearwardly relative to the lower slot  330  (the upper and lower slots  228 ,  230  extend rearwardly to approximately the same point); the rearwardmost end of the upper slot  328  is between about 1 and 3 inches rearward of the rearwardmost end of the lower slot  330 . Also, the backrest  340  includes a cushion  341  that is tapered as it extends away from the front of the arm  322 . 
     In the folded position (FIG.  15 A), the upper and lower posts  344 ,  346  attached to the backrest  340  are positioned in their rearwardmost positions in the upper and lower slots  328 ,  330 . As a result, the panel  340   a  of the backrest  340  is generally upright, with a slight rearward tilt relative to vertical. Due to the taper in the backrest cushion  341 , the front surface  340   b  of the backrest cushion  341  has a greater rearward tilt than the panel  340   a . Consequently, the backrest cushion  341  need not have a wedge-shaped section (like that of the sofa-bed  200 ) to provide a comfortable inclined backrest surface. 
     Both of the sofa-bed embodiments  200 ,  300  can be positioned with their respective back panels immediately adjacent a wall and moved between the folded and unfolded positions without striking the wall. As such, these embodiments do not require some space (usually 3 inches or so) between the backrest and the wall to allow the bed to move between positions. 
     Still another embodiment of the present invention is illustrated in  FIGS. 16-19 . A sofa-bed, designated broadly at  400 , includes a backrest  440  of similar configuration to those illustrated in the embodiments described above. The subseat  462 , however, lacks an attached cushion of the type shown in the embodiments of  FIGS. 1-15B . The seat  490  includes a seat cushion  491  of the type shown in the previous embodiments. A subseat cushion  492  is attached via a cloth hinge  493  to the rear edge of the seat cushion  491 . In the folded position, the subseat cushion  492  is in stacked relationship overlying the seat cushion  491 . As such, the subseat cushion  492  can serve as the cushion upon which an occupant sits when the sofa-bed  400  is in the folded position; there is no need to include an additional separate cushion that is removed prior to the unfolding of the sofa-bed  400 . 
     Folding and unfolding of the sofa-bed  400  is carried out in much the same manner as for the embodiments of FIGS.  1 - 15 B: the backrest  440  follows a similar path, typically controlled by posts moving within slots in the arms of the sofa-bed  400 , the seat  490  moves from a horizontal position within the frame to a horizontal position forward of the frame, and the subseat  462  moves from an inverted position to a non-inverted position between the seat  490  and the backrest  440  (see FIGS.  16 - 18 ). Once the sofa-bed  400  is in the unfolded position, the subseat cushion  492  can be inverted by pivoting it about the cloth hinge  493  to an inverted position overlying the subseat  462  (FIG.  19 ). 
     The configuration of the sofa-bed  400  is particularly desirable in environments in which it may be unappealing to have a removable seat cushion. Exemplary environments include hospital rooms or other health care facilities, where it may be desirable to have furniture that converts between a seating unit and a bed (for example, for an individual who chooses to stay with a patient in a hospital room) but may be undesirable to have loose cushions in the room for space or sanitary reasons. 
     The foregoing embodiments are illustrative of the present invention, and are not to be construed as limiting thereof. Although exemplary embodiments of this invention have been described, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of this invention. Accordingly, all such modifications are intended to be included within the scope of this invention as defined in the claims. The invention is defined by the following claims, with equivalents of the claims to be included therein.