Patent Publication Number: US-6668395-B1

Title: Roll-in futon bed

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates to an article of furniture that is useful as a futon and which may also be easily converted into a bed or a chaise lounge. 
     2. Description of the Prior Art 
     A futon is generally considered to be an article of furniture that may be used as a bed, but which may be configured so as to have a back and bench shaped as a couch for occupancy, usually by a single person. Unlike a couch, a futon does not have arms on its sides. 
     Various articles of furniture have been constructed with a feature of convertibility whereby a futon can be converted to a bed. In such an arrangement the back of the futon is constructed so as to be alternatively oriented in a flat disposition relative to the seat bench, so as to form a flat bed. Alternatively, the back support section can be oriented to an upright, slightly inclined disposition relative to the seat bench so that the article of furniture becomes a futon. 
     Some prior devices have been constructed so that the seat bench portion of the furniture article slides or rolls into a frame, or is alternatively extended from a frame, depending upon whether the article of furniture is to serve as a futon or as a bed. However, all prior devices of this type are somewhat cumbersome to operate or inordinately expensive to build. 
     SUMMARY OF THE INVENTION 
     One object of the present invention is to provide an article of furniture that is convertible as between a bed and a futon in which the movable seat bench portion can be easily rolled into a stationary frame in such a manner as to easily, but releaseably latch in position relative to the outer, stationary frame. In addition, the article of furniture is constructed so that the seat bench latch will not readily become disengaged in an unexpected manner, but which can easily be purposefully disengaged to draw the seat bench out away from the outer frame, if desired. 
     A related object is the provision of a convertible futon bed in which the futon seat bench can be easily disengaged from the outer frame and rolled out away from the head frame of the outer support to collapse the portions of the base frame assembly into a flat bed frame. The seat bench can also easily rolled back in toward the head frame to create a futon seat back located behind the futon seat bench. The article of furniture of the invention is provided with cam latches that firmly, but releaseably secure the futon seat bench in front of the seat back frame for use as a seating support. 
     Another object of the invention is to provide a roll-in futon that can alternatively be deployed as either a flat bed or a chaise lounge. 
     In one broad aspect the invention may be described as a convertible article of furniture comprising a stationary outer support and a movable base frame assembly. The outer support is formed with a central, transverse head frame from both ends of which mutually parallel side frames extend longitudinally in spaced separation from each other. The movable base frame assembly is supported on rolling members such as wheels, rollers, or casters, for longitudinally reciprocal movement relative to the stationary outer support and between the side frames. The movable base frame assembly has a longitudinally distal seat bench frame remote from the head frame and an intermediate back frame located between the seat bench frame and the head frame. The seat bench frame and the intermediate back frame are hinged to each other. The side frames of the stationary outer support are each provided with a roller located remote from the heat frame. The rollers are oriented for rotation about horizontal roller axes that are perpendicular to the side frames. The seat bench frame has a distal portion longitudinally remote from the head frame. The seat bench frame also has cam latches with arcuate, downwardly facing concave seating recesses defined therein projecting downwardly from its distal portion. 
     The cam latches include longitudinally oriented cam surfaces inclined in a direction downwardly and away from the head frame and toward the seating recesses. As a result, as the seat bench frame approaches the head frame, the cam surfaces ride up the rollers to elevate the longitudinally distal portion of the seat bench frame and then releaseably lodge the concave seating recesses upon the rollers. The seat bench frame and intermediate seat back frame are typically provided with a conventional cushioning pad so as to afford a measure of comfort to the user or users. 
     In another broad aspect the invention may be considered to be an improvement in an article of furniture having a stationary support with upright, mutually parallel opposing sides and a base frame assembly movable between the opposing sides and parallel thereto, and in which the base frame assembly includes a seat bench frame and at least an intermediate seat back frame hinged to the seat bench frame for rotational movement relative thereto. The seat bench frame is provided with supporting rolling members. The improvement of the invention is comprised of a roller on each of the sides of the stationary support. The rollers are oriented for rotation about axes perpendicular to the sides of the stationary supports. Also, cam latches are provided on opposing sides of the seat frame in longitudinal alignment with the rollers. The cam latches include concave downwardly facing seating recesses and cam surfaces inclined longitudinally and upwardly therefrom and toward the intermediate seat back frame. Consequently, when the seat bench frame is moved to engage the cam latches with the rollers, the cam surfaces of the cam latches ride up the rollers and the seating recesses lodge on the rollers in releaseable latching engagement therewith when moved into registration with the rollers. 
     In still another aspect, the invention may be considered to be a roll-in futon comprising: a stationary outer support and a movable base frame assembly. The stationary outer support is formed with a laterally extending head frame having opposing ends and a pair of mutually parallel side frames at the opposing ends of the head frame. The side frames extend in a footward direction from the head frame. Rollers are rotatably mounted on the side frames for rotation about axes perpendicular thereto. The movable base frame assembly includes a seat bench frame located in a footward direction from the head frame and at least an intermediate back support frame located between the head frame and the seat bench frame and joined by a footward hinge for movement relative to the seat bench frame. The movable base frame assembly also includes cam latches that project downwardly from the seat bench frame and include concave downwardly facing seating recesses and cam surfaces inclined upwardly therefrom and toward the head frame. The rollers engage the cam latches as the intermediate back support frame approaches the head frame, and the rollers lift at least a portion of the seat frame as the cam surfaces ride up the rollers. The seat frame is releaseably lodged relative to the stationary support when the rollers engage the concave seating surfaces of the cam latches. 
     Preferably, base frame assembly further includes a proximal back frame hinged to the intermediate back frame and located between the intermediate back frame and the head frame. The seat bench frame, the intermediate seat back frame, and the proximal seat back frame are joined together in articulated fashion. The proximal back frame is rotatably secured to the side frames at back frame axle pins located proximate the head frame for rotation relative to the side frames about a proximal back frame axis of rotation perpendicular to the side frames. When the article of furniture is converted to a bed, the proximal back frame lies immediately adjacent to the head frame with the intermediate back frame and the seat bench frame extending longitudinally therefrom in that order in a footward direction. 
     The cam latching mechanism of the convertible futon is an extremely important aspect of the invention. The cam surfaces of the cam latches are preferably formed on vertical cam plates and are inclined at an angle of between about twenty-five degrees and about forty-five degrees relative to the seat bench frame at the time the rollers first contact the cam surfaces. In the preferred embodiment this angle of inclination is about thirty-three degrees relative to the horizontal orientation of the seat bench frame. 
     Also, a proper selection of the size and configuration of the rollers and the seating recesses improves the smoothness of latching and unlatching the cam latching mechanism. The rollers have a contact surface diameter typically between about one-half inch and about one and one-half inches, preferably about seven-eighths of an inch. The concave recesses are both preferably shaped with a circular arc at a diameter of between about one and two inches. The arc of the seating recesses can vary somewhat, but normally is between about thirty and ninety degrees. In the preferred embodiment the circular arc of the concave seating recesses is formed at a diameter of about one and three-eighths inches and extends over a circular arc of about sixty degrees. 
    
    
     The invention may be described with greater clarity and particularity by reference to the accompanying drawings. 
     DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of an article of furniture according to the invention with the base frame assembly extended from the stationary support to form a bed. 
     FIG. 2 is a side elevational view illustrating the article of furniture of FIG. 1 while the base frame assembly is being pushed toward the head frame to convert the bed of FIG. 1 to a futon. 
     FIG. 3 illustrates the article of furniture of FIGS. 1 and 2 when converted to a chaise lounge. 
     FIG. 4 illustrates the manner in which the angle of inclination of the portion of the base frame may be adjusted when the article of furniture is utilized as a chaise lounge. 
     FIG. 5 is a side elevational view illustrating the article of furniture with the base frame assembly completely rolled into the stationary support to convert the article of furniture to a futon. 
     FIG. 6 is a top plan view of the article of furniture converted to a futon as shown in FIG. 5, but with the padding omitted for clarity of illustration. 
     FIG. 7 is a sectional elevational detail illustrating the seat bench frame of the article of furniture as it approaches the futon position shown in FIG.  5 . 
     FIG. 8 illustrates the initial engagement of the roller with the cam surface as the base frame assembly is rolled into the stationary outer support. 
     FIG. 9 illustrates the engagement of the roller (shown partially broken away) at about the middle of the inclined cam surface of the cam latch plate. 
     FIG. 10 is a bottom plan detail taken along the lines  10 — 10  of FIG.  1 . 
     FIG. 11 illustrates the cam latch mechanism engaged with the base frame assembly completely rolled into the stationary outer support, taken along the lines  11 — 11  of FIG. 6, and with the roller partially broken away. 
    
    
     DESCRIPTION OF THE EMBODIMENT 
     FIG. 1 illustrates an article of furniture indicated generally at  10  that is comprised of a stationary support  12  and a base frame assembly  14  that is movable in a longitudinal direction relative to the stationary support  12 . The stationary outer support  12  is formed with a central, transverse head frame  16  from both ends of which mutually parallel side frames  18  and  20  extend longitudinally in uniform spaced separation from each other, as shown in FIG.  6 . The movable base frame assembly  14  is supported on rolling members, which preferably are wheels  22 , as shown in FIGS. 1-5. The wheels  22  allow the base frame assembly  14  to be longitudinally moved in reciprocal fashion relative to the stationary outer support  12  and between the side frames  18  and  20 . The base frame assembly  14  has a seat bench frame  24 , an intermediate back frame  26 , and a proximal back frame  28 . The terms proximal and distal as utilized herein refer to relative proximity to the head frame  16 . The direction “footward”, as utilized herein refers to the direction away from the head frame  16  and between and parallel to the side frames  18  and  20 , indicated by the directional arrow  115  in FIG.  6 . 
     The seat bench frame  24  is located in a longitudinally distal relationship with respect to the head frame  16  and the intermediate back frame  26  is located between the seat bench frame  24  and the head frame  16 . The proximal back frame  28  is located between the intermediate back frame  26  and the head frame  16 . As shown in FIG. 1, the seat bench frame  24  and the intermediate back frame  26  are joined to each other by hinges  30  on their top sides, while the intermediate back frame  26  and the proximal back frame  28  are joined together by hinges  32  on their bottom sides, as illustrated in FIG.  2 . The seat bench frame  24 , the intermediate back frame  26 , and the proximal back frame  28  are thereby hinged together in articulated fashion for rotation relative to each other about axes of rotation perpendicular to the side frames  18  and  20 . 
     As illustrated in FIGS. 7 through 11, the side frames  18  and  20  are each provided with a roller  34  located remote from the head frame  16  and oriented for rotation about horizontal roller axes  36  and  38 , which are in coaxial, transverse alignment with each other, as illustrated in FIG.  6 . The rollers  34  have cylindrical rolling contact surfaces  35  and are flared outwardly at their extremities to form generally frustoconical-shaped retaining guards  37 , as illustrated in FIG.  10 . The roller axes  36  and  38  are perpendicular to the side frames  18  and  20 . 
     The seat bench frame  24  has a longitudinally distal or footward portion  40  located remote from the head frame  16  and a longitudinally proximal portion  42  which is joined by the hinges  30  to the intermediate back frame  26 . 
     A pair of cam latches  44  are located on the underside of the longitudinally distal portion  40  of the seat bench frame  24  near the transverse outboard extremities of the seat bench frame  24 . As illustrated in FIGS. 7-11, the cam latches  44  are formed of angle sections of steel, the horizontal portion of each of which is welded to the underside of the seat bench frame  24 . The vertical portions of the cam latches  44  are formed as plates that extend downwardly and are configured with arcuate, downwardly facing concave seating recesses  46  and longitudinally oriented cam surfaces  48 . The cam surfaces  48  are inclined in a direction downwardly and away from the head frame  16  and toward the seating recesses  46 , which are located at the distal extremities of the inclined cam surfaces  48 . As can be seen in FIGS. 7-11, as the seat bench frame  24  approaches the head frame  16 , the cam surfaces  48  ride up the rollers  34  to elevate the longitudinally distal portion  40  of the seat bench frame  24  slightly, and then releaseably lodge the concave seating recesses  46  upon the contact surfaces  35  of the rollers  34 , as illustrated in FIG.  11 . 
     Together, the rollers  34  and cam latches  44  form releaseable cam latch assemblies between the opposing sides of the seat bench frame  24  and the side frames  18  and  20 . When the seating recesses  46  of the cam latches  44  are engaged with the rollers  34 , the article of furniture  10  is configured as a futon for seating, as illustrated in FIGS. 5 and 6. 
     The head frame  16  is formed of a pair of vertically spaced, mutually parallel tubular steel head rails  50  that extend transversely across the width of the article of furniture  10 . The head rails  50  terminate at hollow, cylindrical, upright proximal headboard posts  52  at the longitudinally proximal extremities of the side frames  18  and  20 . The head frame  16  also includes a head frame backing structure  56  formed of a pair of upright standards  58  the upper portions of which are inclined slightly away from the side frames  18  and  20 . The lower ends of the standards  58  are fastened to the rails  50  by bolts  54 . A transverse, tubular, cylindrical upper head guard  60  is welded to the upper extremities of the upright head frame standards  58  so that the head guard  60  is held in a horizontal, transverse orientation. A stiffening rod  62  is located about four inches beneath the head guard  60  and is oriented parallel thereto. The ends of the stiffening rod  62  are welded to the upright standards  58 . 
     Each of the side frames  18  and  20  is comprised of a pair of longitudinally extending rails, including an upper rail  64  and a lower rail  66 . The rails  64  and  66  extend longitudinally, parallel to each other and terminate at distal, upright, stationary support posts  68 , to which they are welded. The longitudinal rails  64  and  66  of the side frames  18  and  20  are also welded to the proximal support posts  52 . A U-shaped center reinforcing frame (not visible) spans the distance between the lower rails  66 . The legs of the reinforcing center frame are fastened to the side rails  66  by bolts  70  at a spaced distance of separation from the plane of the transverse head frame rails  50 . 
     As illustrated in FIGS. 7-11, the rollers  34  are mounted for rotation on steel spindles  72  having hexagonal retaining heads that project transversely and inwardly toward each other from upright, square, tubular mounting posts  74 . The mounting posts  74  are welded to the inside surfaces of the lower longitudinal rails  66  of the side frames  18  and  20 . The rollers  34  have generally cylindrical contact rolling surfaces  50  formed at a diameter of about seven-eighths of an inch. The inboard ends of each of the rollers  34  are flared radially outwardly so as to form guards  37  that are larger in diameter than the rolling surfaces  35  to limit any transverse movement of the cam latches  44  relative thereto. 
     The seat bench frame  24  and the intermediate back frame  26  are both formed with square tubular steel, peripheral members that are joined together in a configuration that is generally rectangular, but with rounded ends at two corners to form a peripheral framework. The seat bench frame  24  has a peripheral framework  76  while the intermediate back frame  26  has a peripheral frame  77 . The frameworks  76  and  77  are stiffened by tubular, longitudinally extending stiffening members  78 , the ends of which are welded to the interior surfaces of the peripheral frameworks  76  and  77 . Wires forming a tight steel mesh  80  are secured across the upper surfaces of the peripheral rims  76  and  77  and the stiffening members  78  and are firmly secured thereto to provide support for a cushioning pad  110  thereon. The mesh opening size of the meshes  80  is preferably about two and three-eighths inches in a transverse direction and about two and five-eighths inches in a longitudinal direction. The term transverse direction, as utilized herein, is a direction parallel to the alignment of the rails  50  of the head frame  16  and perpendicular to the side frames  18  and  20 . The term longitudinal direction, as utilized herein, is a direction parallel to the alignment of the rails  64  and  66  of the side frames  18  and  20 . 
     The construction of the proximal back frame  28  differs somewhat from the construction of the seat bench frame  24  and intermediate back frame  26 . The proximal back frame  28  also has a peripheral framework  82  formed of tubular steel having a square cross section and shaped generally in the form of a rectangle, rounded at two corners. However, the peripheral framework  82  includes a transverse stiffening rail  84  near its distal end. The proximal back frame  28  is further comprised of an interior backrest  85  having an outer backrest framework  86  located within the confines of the peripheral framework  82 . The backrest framework  86  is formed of tubular steel having a circular cross section and is reinforced by longitudinal stiffening ribs  88 , also formed of tubular steel having a circular cross section of three-quarter inches in diameter. The wire mesh  80  of the proximal back frame  28  is stretched across and fastened to the backrest framework  86 . 
     The rounded corners of the backrest framework  86  are directed proximally toward the head frame  16 , while the opposite ends of the backrest framework  86  terminate in feet  89  that extend into and form part of unidirectional ratchet and pawl backrest inclination adjustment devices  90 . The unidirectional ratchet and pawl backrest inclination adjustment devices  90  are conventional mechanisms that may be purchased commercially. 
     The feet  89  at the distal end of the backrest framework  86  terminate in disc-shaped appendages lying in vertical, longitudinal planes and are provided with ratchet teeth about their outer peripheries. A spring-loaded pawl within a surrounding housing for the ratchet and pawl mechanisms in the backrest inclination adjustment devices  90  is biased to engage the teeth on the ends of the feet  89  and allow stepwise counterclockwise motion of the backrest framework  86  relative to the peripheral boundary framework  82 . The inner peripheral backrest framework  86  may be moved in incremental, counterclockwise steps of rotation, as viewed in FIGS. 3 and 4, relative to the outer peripheral boundary framework  82  to allow the backrest inclination adjustment devices  90  to support the backrest framework  86  at a selected acute angle of inclination relative to the outer peripheral framework  82 . That is, with reference to FIGS. 3 and 4, the backrest  85  may be rotated in a counterclockwise direction stepwise, to increase the acute angle between the backrest framework  86  and the outer peripheral framework  82 . However, the pawl engagement system prevents clockwise rotation of the backrest framework  86  relative to the peripheral framework  82  when the backrest  86  is at an acute angle relative thereto, as illustrated in FIG.  3 . 
     However, to completely release the ratchet and pawl mechanism within the backrest inclination adjustment devices  90 , the backrest framework  86  can be moved all the way forward in a counterclockwise direction to the position indicated in solid lines in FIG.  4 . At this point, the catch mechanisms of the backrest inclination adjustment devices  90  are disengaged and the backrest  85  can be freely rotated all the way down into a flat, coplanar relationship relative to the peripheral framework  82 , as illustrated in FIG.  1 . 
     The backrest inclination adjustment devices  90  connect the backrest framework  86  of the interior backrest  85  to the peripheral framework  82  of the proximal back frame  28  at a backrest axis of rotation  92 , which extends transversely across the article of furniture  10 , as illustrated in FIG.  1 . The backrest inclination adjustment devices  90  include catch mechanisms for holding the backrest  85  at a selected acute angle relative to the peripheral framework  82  of the proximal back frame  28 . However, the catch mechanisms are releaseable to allow the backrest  85  to reside in coplanar relationship with the peripheral framework  82 , as illustrated in FIG.  6 . 
     The proximal back frame  28  is rotatably secured to the side frames  18  and  20  by transverse back frame axle pins  94  that are located proximate the head frame  16 . That is, the back frame axle pins  94  extend through the upper side rails  64  of the side frames  18  and  20  and into the outer peripheral framework  82  of the proximal back frame  28 . The proximal back frame  28  is thereby rotatably mounted within the side frames  18  and  20  for rotation relative thereto about the proximal back frame axis of rotation  96 , which is perpendicular to the side frames  18  and  20 . The back frame axle pins  94  join the proximal back frame  28  to the side frames  18  and  20  at a spaced distance of separation from the head frame  16 . This distance may, for example, be between about six inches and twenty-four inches, depending upon the size of the article of furniture  10 . 
     The peripheral framework  82  of the proximal back frame  28  is thereby rotatably joined by the back frame axle pins  94  to the side frames  18  and  20 , while the interior backrest  85  is mounted within the peripheral framework  82  for rotation about the backrest axis of rotation  92  that is parallel to the proximal back frame axis of rotation  94 . The backrest axis of rotation  92  is located at the distal portion of the proximal back frame  28  near its hinged connection with the intermediate back frame  26  to which it is coupled by the hinges  32 . The proximal back frame  28  includes a proximal portion  97  and a distal portion  99 , which may be considered to be delineated from each other by the back frame axis of rotation  94 . The proximal back frame portion  97  fits within the spaced distance of separation of the back frame axle pins  94  from the transverse rails  50  of the head frame  16 . 
     The cam latch mechanism, which forms a very important aspect of the invention, is illustrated in FIGS. 7 through 11. As illustrated in FIG. 1, the article of furniture  10  may be utilized as a bed in which the seat bench frame  24 , the intermediate back frame  26 , and the proximal back frame  28  all lie in coplanar alignment with each other. When the article of furniture  10  is deployed for use as a bed, the seat bench frame  24  resides at the location must remote from the head frame  16 , while the proximal back frame  28  is closest to the head frame  16 . 
     The seat bench frame  24  is supported from beneath by a pair of longitudinally aligned, transversely separated, U-shaped mounting leg structures  100  which are equipped with central, longitudinal portions  102 . The linear portions  102  are bolted to the two outboard longitudinal stiffening members  78  that are located closest to the longitudinal sides of the peripheral framework  76 . The mounting leg structure  100  also has depending distal legs  104  and proximal legs  106  that extend downwardly from the linear portions  102 . The wheels  22  are mounted on the lower extremities of the leg portions  104  and  106 . The wheels  22  are mounted for rotation about transverse axes of rotation relative to the legs  104  and  106 . It is to be understood that rollers or casters could be substituted for the wheels  22 , if desired. 
     When the article of furniture  10  is deployed in the condition of a bed, as illustrated in FIG. 1, the back rest  85  resides in coplanar relationship within the peripheral framework  82  of the proximal back frame  28 . The peripheral framework  82  of the proximal back frame  28  rests upon proximal and distal flat, horizontal flanges  108 , which are welded to and extend inwardly from the inside surfaces of the upper longitudinal rails  64  of the side frames  18  and  20 . Normally the weight of a person or any other weight lying atop the article of furniture  10  employed in the bed position of FIG. 1 is transmitted to the floor surface supporting the article of furniture  10  through the legs  104  and  106  and the wheels  22  beneath the seat bench frame  24  and through disc-shaped rubber pads (not visible) located on the undersides of the outboard longitudinal members of the peripheral framework  82  of the proximal back frame  28 , which rest upon the flanges  108 . 
     When a user desires to convert the article of furniture  10  from a bed, as illustrated in FIG. 1, to a chaise lounge, as illustrated in FIG. 3, the user lifts upwardly upon the transverse member of the backrest framework  86  located closest to the end frame  16  to raise the backrest  85 , as illustrated in FIG.  3 . In this drawing figure an elongated, rectangular cushioning pad  110  is shown resting atop the frames  24 ,  26 , and  28  of the movable base frame assembly  14 . The cushioning pad  110  is normally formed of foam rubber or some other soft, cushioning material, encapsulated within an outer protective cover. To hold the pad  110  in position on the movable base frame assembly  14 , the pad  110  is provided with a flap forming a pocket  112  on its underside at its proximal end. The pocket flap  112  fits over the backrest framework  86  to aid in holding the pad  110  in position on the movable base frame assembly  14 . When the article of furniture  10  is utilized as a chaise lounge, the natural resiliency of the pad  110  may cause the proximal portion of the pad  110  to pull away from the backrest  85  slightly, as illustrated in FIG.  3 . However, if the chaise lounge is occupied by a person, the proximal portion of the pad  110  will be pressed back against the backrest  85 . 
     The article of furniture  10  may also be utilized as a roll-in futon. To transform the article of furniture  10  for this use, the intermediate back frame  26  is provided with a pair of knobs  113 , projecting transversely outwardly in front of the distal support posts  68 . To deploy the article of furniture  10  as a futon, the back rest  86  is first moved all the way in a counterclockwise direction to release the ratchet and pawl catch mechanism, as shown in FIG. 4, and then lowered all the way back down in a clockwise direction as illustrated at  85 ′ into the plane of the surrounding peripheral framework  82 . The article of furniture  10  is thereupon in the condition illustrated in FIG. 1 for use as a bed. 
     To continue conversion of the device to use as a futon, a user lifts the proximal portion of the intermediate back frame  26  upwardly utilizing the knobs  113 , as illustrated in FIG.  2 . The proximal back frame  28  thereupon rotates about the back frame axle pins  94  as the seat bench frame  24  rolls in toward the stationary outer support  12 , as illustrated by the directional arrow  114  indicated in FIG.  2 . Since the proximal back frame  28  and the intermediate back frame  26  are hinged together on the undersides of their respective peripheral frameworks  82  and  77  by the hinges  32 , the proximal back frame  28  will rotate upwardly in a clockwise direction about the back frame axle pins  94 , while the intermediate back frame  26  rotates in a counterclockwise direction relative to the proximal back frame  28  by virtue of its articulated, hinged connection to the distal end of the proximal back frame  28 . Meanwhile, the seat bench frame  24  remains in a horizontal orientation and moves inwardly in between the side frames  18  and  20 , as indicated by the directional arrow  114  in FIG.  2 . The hinges  30  allow relative rotation to occur between the intermediate back frame  26  and the seat bench frame  24 . 
     As the seat bench frame  24  is rolled in toward the head frame  16  between the side frames  18  and  20  to approach the head frame  16 , the cam latch  44  approaches the roller  34 , as illustrated in FIG.  7 . As the seat bench frame  24  continues to roll in to approach the head frame  16 , the inclined cam surfaces  48  of the cam latches  44  are brought into contact with the cylindrical roller contact surfaces  35  of the rollers  34 , as shown in FIG.  8 . Continued advancement of the seat bench frame  24  toward the head frame  16  causes the inclined cam surfaces  48  of the cam latches  44  to ride up the rollers  34  in the manner illustrated in FIG.  9 . This causes the wheels  22  on the distal legs  104  to leave the floor surface upon which the article of furniture  10  is placed and for the seat bench frame  24  then to be inclined slightly downwardly toward the head frame  16 . The distal portion  40  of the seat bench frame  24  residing above the distal legs  104  is thereby lifted slightly as the inclined cam surfaces  48  progress across the rolling surfaces  35  of the rollers  34 . 
     The roller  34  has a cylindrical roller surface of contact  35  which has a diameter of about seven-eighths of an inch. The concave recess  46  is shaped with a circular arc centered on a diameter of about one and three-eighths inches and extending over an arc of about sixty degrees. The flanges  108  are located slightly above the rolling surfaces  35  of the rollers  34  and extend horizontally inwardly from the opposing side frames  18  and  20  beneath the movable base frame assembly  14 . The wheels  22  support the movable base frame assembly  14  so that there is a slight clearance between the underside of the peripheral framework  76  of the seat bench frame  24  and the distal flange plates  108  located proximate the upright posts  68 . 
     As the distal extremity of the seat bench frame  24  passes alignment with the distal support posts  68 , the cam surfaces  48  leave contact with the rollers  34 , and the concave, arcuate, downwardly facing seating recesses  46  are brought into contact with the contact surfaces  35  of the rollers  34 . Because of the configuration of the seating recesses  46 , the cam latches  44  drop downwardly slightly, thereby lodging the concave seating recesses  46  of the cam latches  44  onto the rollers  34  while the longitudinally distal extremity  40  of the seat bench frame  26  is elevated slightly, as illustrated in FIG.  11 . When the cam latch mechanisms are engaged as illustrated in FIG. 11, the article of furniture  10  is deployed for use a futon, as illustrated in FIGS. 5 and 6. 
     To disengage the cam latching mechanisms, a user merely grasps the transverse, distal portion of the peripheral framework  76  of the seat bench frame  24  from its underside and pulls slightly upwardly and slightly away from the head frame  16 , in the direction indicated by the directional arrow  115  in FIG.  6 . This will dislodge the seating recesses  46  from the contact surfaces  35  of the rollers  34 . The seat bench frame  24  can then be pulled longitudinally outwardly away from the head frame  16  and rolled on all the wheels  22  out away from the head frame  16  in the longitudinal direction  115  opposite to the direction indicated by the directional arrow  114  in FIG.  2 . The article of furniture  10  can thereafter be deployed as either a bed, in the manner illustrated in FIG. 1, or as a chaise lounge, in the manner illustrated in FIG.  3 . 
     Undoubtedly, numerous variations and modifications of the invention will become readily apparent to those familiar with articles of furniture and their construction. For example, there are many different backrest inclination adjustment devices that may be employed in place of the rachet and pawl mechanisms employed in the backrest inclination adjustment devices  90 . Also, the configuration of the rollers  34  and the cam plates  44  may vary considerably depending upon the dimensions of the different frames of the article of furniture  10 . In addition, the locations of the rollers  34  and the cam latches  44  are equivalent even if they are reversed. That is, the cam laches  44  can be located reversed in orientation and inverted so that the cam surfaces  46  are located further from the head frame  16  than the concave recesses, and the concave recesses  48  then face upwardly. The rollers that extend transversely outwardly from the seat bench frame  24  will then ride up the cam surfaces  46  and lodge in the seating recesses  48  when the article of furniture is to be utilized as a futon. Accordingly, the scope of the invention should not be construed as limited to the specific embodiment depicted and described, but rather is defined in the claims appended hereto and equivalent structures.