Abstract:
A sofa bed is convertible to a bunk bed using front and rear links coacting with gas cylinders to lift a bunk frame from the sofa position, in which it is used for seating, to a bunk bed position where seat cushions are used on the bunk and a mattress is available for a lower bunk, being lockable in a down, or seating position and lockable in and up, or bunk bed position with a brace and ladder deployable to secure the bunk.

Description:
CLAIM OF PRIORITY 
       [0001]    This application claims priority on Provisional application Ser. No. 62/259,956 filed Nov. 26, 2015, having the same title and inventor as the present application and having attorney docket No. CU-72546. This application claims priority on copending application Ser. No. 15/360,791 filed Nov. 23, 2016. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    Field of the Invention 
         [0003]    The present invention relates generally to a furniture assembly, and more particularly, to a sofa bed convertible into a bunk bed having a mechanism being compact and particularly adaptable to placement in vehicles or dimensionally limited locations. 
         [0004]    Background 
         [0005]    A sofa usually has a seating surface, a back surface, and arms, while a bunk bed has a plurality of sleeping surfaces oriented with at least a portion of a top sleeping surface vertically displaced above a lower sleeping surface. The convertible bunk bed stores the bed in the area above the seating surface. In the prior art EP2110054 (A1) “Mechanism for bunk beds and sofa-bed comprising this mechanism” appears to use curved links to enable a bunk bed to be moved vertically to a position above the lower bed. In the prior art CN202553068 (U) “Novel dual-use sofa” the arms of the sofa are pivoted so that the top bunk is inverted when the sofa is in the seating position and when rotated 180 degrees upwardly so that the frame inverts to present the opposite surface for sleeping. 
         [0006]    The former utilizes a mechanism of some complexity for ease of deployment, but lacks a desirable level of rigidity and support when in the bunk bed position. The latter requires a substantial range of motion for movement of significant mass in directions atypical to the user. 
         [0007]    In the prior art U.S. Pat. No. 405,495 “Foldable Bunk Bed Assembly” a hinged outer portion of a seat back converts to upper bunk but requires mounting on a wall or bulkhead. U.S. Pat. No. 7,360,261 “Sofa” hinges the seat back to the seat back frame pivoting upward to a bunk bed position. U.S. Pat. No. 4,592,101, “Sofa-bunk bed combination with pivotable cushion” pivots and elevates the seat back to be used as the top bunk. Published application CN202553068U “Novel dual-use sofa” has a hinged front and rear portion with overlapping platforms in which the front portion rotates forwardly and upwardly and inverts, the upper inverted platform forming the bunk bed and the lower platform forming the lower bed. Published application EP2110054 (A1) “Mechanism for bunk beds and sofa-bed comprising this mechanism” uses complex linkage to raise and invert a lower seat platform so that when inverted and fully raised it forms a top bed in a bunk bed. 
         [0008]    The present invention solves problems in the prior art described above. The sofa convertible to a bunk bed described herein provides superior sleeping surfaces in a more compact footprint and range of motion, while additionally providing structure for mounting in vehicles and clearance for mounting such securement apparatus as seat belts and harnesses over that of the prior art sofa bunk beds. Links acting in combination with pneumatic cylinders or other telescoping struts provide mechanical advantage and locking for a trussile support mechanism. The frame design additionally incorporates guards and ladders in a unitary assemblage. 
         [0009]    Two main embodiments are shown, one with a front link having a pivot carried in a track and a second having fixed pivot for the front link. Each embodiment may have alternative embodiments within the teaching of the main embodiment. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0010]      FIG. 1  is a front elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position. 
           [0011]      FIG. 2  is a side elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position. 
           [0012]      FIG. 3  a perspective view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position. 
           [0013]      FIG. 4  is a front elevational view of an embodiment of the sofa convertible to a bunk bed in the sofa position. 
           [0014]      FIG. 5  is a side elevational view of an embodiment of the sofa convertible to a bunk bed in the sofa position. 
           [0015]      FIG. 6  is a top plan view of an embodiment of the sofa convertible to a bunk bed with the front guard undeployed. 
           [0016]      FIG. 7  is a perspective view of an embodiment of the sofa convertible to a bunk bed in the sofa position. 
           [0017]      FIG. 8  is a perspective view of an embodiment of the sofa convertible to a bunk bed in the mid-position. 
           [0018]      FIG. 9  is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the sofa position. 
           [0019]      FIG. 10  is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the mid-position. 
           [0020]      FIG. 11  is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position taken on line A-A of  FIG. 1 . 
           [0021]      FIG. 12  is a perspective view of an embodiment of the sofa with mattress and cushions shown. 
           [0022]      FIG. 13  is a perspective view of an embodiment of the sofa with mattress and cushions shown with the bunk configured for sleeping. 
           [0023]      FIG. 14  is a perspective view of an embodiment of the sofa back cushion.  FIG. 1  is a front elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position. 
           [0024]      FIG. 15  is a side sectional view of an embodiment of the sofa taken on line A-A of  FIG. 1  having a first alternative track and gas cylinder pivot location. 
           [0025]      FIG. 16  is a side sectional view of an embodiment of the sofa taken on line A-A of  FIG. 1  having a second alternative track and gas cylinder pivot location. 
           [0026]      FIG. 17  is a side elevational view of an embodiment of the sofa taken on line A-A of  FIG. 1  having a third alternative track and gas cylinder pivot location. 
           [0027]      FIG. 18  is a side elevational view of an embodiment of the sofa taken on line A-A of  FIG. 1  having a fourth alternative track and gas cylinder pivot location. 
           [0028]      FIG. 19  is a front elevational view of another embodiment of the sofa convertible to a bunk bed in the bunk bed position. 
           [0029]      FIG. 20  is a side elevational view of another embodiment of the sofa convertible to a bunk bed in the bunk bed position. 
           [0030]      FIG. 21  a perspective view of another embodiment of the sofa convertible to a bunk bed in the bunk bed position. 
           [0031]      FIG. 22  is a front elevational view of another embodiment of the sofa convertible to a bunk bed in the sofa position. 
           [0032]      FIG. 23  is a side elevational view of another embodiment of the sofa convertible to a bunk bed in the sofa position. 
           [0033]      FIG. 24  is a top plan view of an embodiment of the sofa convertible to a bunk bed with the front guard undeployed. 
           [0034]      FIG. 25  is a perspective view of an embodiment of the sofa convertible to a bunk bed in the sofa position. 
           [0035]      FIG. 26  is a perspective view of an embodiment of the sofa convertible to a bunk bed in the mid-position. 
           [0036]      FIG. 27  is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the sofa position, taken on line A-A of  FIG. 19 . 
           [0037]      FIG. 28  is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the mid-position. 
           [0038]      FIG. 29  is a sectional elevational view of an embodiment of the sofa convertible to a bunk bed in the bunk bed position taken on line B-B of  FIG. 19 . 
           [0039]      FIG. 30  is a fragmentary perspective view of the left side linkage assembly, looking from the rear towards the front. 
           [0040]      FIG. 31  is a fragmentary perspective view of the right side linkage assembly, looking from the rear towards the front. 
           [0041]      FIG. 32  is a sectional view of a powered variation on an alternative embodiment. 
           [0042]      FIG. 33  is a fragmentary sectional view of a lock mechanism 
           [0043]      FIG. 34  is a perspective view of an embodiment in the bunk bed position. 
       
    
    
       [0044]    Terms such as front, side, rear, left and right as may be used herein are relative terms referring to the sofa convertible to a bunk bed and are not limited to its mounting, installation or arrangement to any particular position or space in a room or vehicle or to which direction a person is oriented on the sofa or bed. Unless otherwise qualified left and right refer to the point of view of a person sitting on the sofa. 
       DETAILED DESCRIPTION 
       [0045]    Referring to the drawings, the sofa bed  10  of this invention is generally shown. The sofa bed  10  includes base frame assembly  12  with side frames  14  and  16  interconnected by rear transverse frame  18  and front transverse frame  20 . Side frames  14  and  16  may be formed of perimetrical frame members, solid plates  22 ,  24 , or a combination. Each plate  22 ,  24  is formed and arranged so as to have an angled, straight tracks or guide slots  26 ,  28 . 
         [0046]    Advantages to using solid sheet or plate could include the substantial elimination of components requiring assembly; the ability to be formed through automated manufacturing means such as laser cutting or other appropriate machining, and the elimination of braces between the tracks or guide slots  26 ,  28  which can be more easily maintained in position by the presence of the solid web between them. 
         [0047]    The upper bunk frame  30  is formed with a lower perimetrical frame  32  and a rear guardrail assembly  34 . On each side is a side guard  36 ,  38 . 
         [0048]    Upper bunk frame  30 , when deployed in the bunk bed position is primarily supported by right and left front links  40 ,  42  and right and left rear links  44 ,  46 . The right and left front links  40 ,  42  are dynamically actuated and statically fixed (when locked) by right and left front cylinders,  48 ,  50 . The right and left rear links  44 ,  46  are dynamically actuated and statically fixed (when locked) by right and left rear cylinders,  52 ,  54 . Cylinders  48 ,  50 ,  52 ,  54  are preferably pneumatic cylinders but equivalents such as hydraulic cylinders, or spring, screw or rack and pinion mechanisms could be used to perform the function of assisting in raising bunk bed frame  30  and maintaining it in the bunk bed position  56 . 
         [0049]    Front brace and ladder assembly  60  is pivotally mounted to the front frame In the bunk bed position  56  ladder  58  is rotated to a vertical position and locked, front brace  60  is rotated to a vertical position and locked with locking mechanism  64 . Front guard  62  is rotated to a vertical position and locked with locking mechanism  64 . Extending upwardly from side frames  14  and  16  are tabs  66 ,  68 . These may be formed with frame members or plate or a combination. 
         [0050]    In an embodiment, here described with reference to left links  42 ,  46  and cylinders  50 ,  54 , which are shown in the sectional views of  FIG. 10, 11 and 12 , left front link  42  has a top pivot  70  and bottom pivot  72 . Left rear link  46  has a top pivot  74  and a bottom pivot  76 . Left front cylinder  48  has an upper pivot which is connected to the corresponding link and a lower cylinder pivot  82 . Left rear cylinder  54  has an upper pivot  84  and a lower pivot  84 . The relative terms top, bottom, upper and lower refer to the orientation of the components when in the bunk bed position. 
         [0051]    Front link bottom pivot  72  is formed and arranged to slide in guide slot  28  thereby providing the range of motion needed to permit the upper bunk frame  30  to move vertically, while also remaining in a substantially horizontal orientation. Rear link bottom pivot  76  is mounted to tab  68  in a fixed location so as to permit link  46  to rotate about pivot  76 . Front link top pivot  70  and rear link top pivot  74  are mounted in fixed front and rear locations on upper bunk frame  30 . 
         [0052]    Left front cylinder  48  is mounted with front cylinder lower pivot  82  in a fixed location on plate  22  and the front cylinder upper pivot connected at front link bottom pivot  72 . As pivot  72  slides in angled slot  28 , pivot  82  causes compression of cylinder  48 . However, as bunk frame  30  is moved first upwardly and frontwardly and then continuing upwardly and rearwardly, cylinder  48  extends to aid in raising frame  30  to the bunk bed position  56 . This movement works together with rear cylinder  52  and rear link  44  through mounting rear cylinder lower pivot  86  on tab  66  with rear cylinder upper pivot  84  mounted to the median portion of rear link  44 . These references refer to the sectional views and the opposite side will be a mirror image of that shown and described. 
         [0053]    As frame  30  is moved from the sofa position toward the mid position, left rear cylinder  54  compresses slightly, but as link  46  passes the axis of cylinder  54 , then cylinder  54  urges link  46  upward toward bunk bed position  56 . In bunk bed position  56  each of right and left front cylinders,  48 ,  50  and right and left rear cylinders,  52 , and  54  may be locked. At this time the ladder  58  and brace  60  are also locked at lock mechanisms  64 . The bed is converted to a sofa in substantially the reverse manner. 
         [0054]    The geometry of links right and left front links  40 ,  42 , right and left rear links  44 ,  46  and their respective front link top pivot  70  front link bottom pivot  72 , rear link top pivot  74  , rear link bottom pivot  76 , front cylinder upper pivot  80 , front cylinder lower pivot  82 , rear cylinder upper pivot  84  and rear cylinder lower pivot  86  is such that manual deployment may be accomplished as described, while alternative cylinders and other actuators and controls could be utilized for automatic deployment. 
         [0055]    The mattress  90  shown in  FIGS. 3, 11, 12 and 13  and the cushions shown in  FIGS. 12 and 13  can advantageously be arranged so that the mattress  90  remains in the same position, either under the frame  30  when in the sofa position or available for sleeping in the bunk bed position  56 . Seat cushion  92  may be thick enough to serve as a top mattress on the top bunk, or seat back cushion  94  could be formed in a foldable manner and unfolded from the sofa seat back configuration to a sleeping configuration. Cushion  92  could remain and be combined with cushion  94  for double the thickness. 
         [0056]    In the alternative embodiments shown in  FIGS. 15, 16, 17 and 18  sectional views at section A-A of  FIG. 1 , different configurations of tracks and links provide properties that may be tailored to specifically desired performance relative to the movement, compactness, strength and mechanical rigidity, noting sofa bed  10  right side frame  14  solid plates  22  guide slot  28  right front link  40  right rear link  44 , right front cylinders  48  and right rear cylinder,  54  generally formed and arranged as described above but with specific variations controlling the movement of the bunk bed assembly as it is raised and lowered. In  FIG. 15  and  FIG. 16  slot  28  has a lower straight portion, a forwardly curving intermediate portion and an upwardly curving upward portion.  FIG. 16  has increased size component sections and reinforcing members on plate  22 .  FIGS. 17 and 18  have some of the components removed for clarity, but show slot  28  in different configurations.  FIG. 17  shows slot  28  in a nearly vertical orientation, with a generally straight lower portion an intermediate curve and a generally straight upward portion. In  FIG. 18  slot  28  has a near vertical lower portion a forwardly curving intermediate portion and a straight upper portion. 
         [0057]    Two main embodiments are shown, one with a front link having a pivot carried in a track and a second having fixed pivot for the front link. In the second embodiment front and rear links each have a lower pivot fixed on the side frame. 
         [0058]    In the embodiment illustrated in  FIG. 19-22  sofa bed  10  has a base frame assembly  212  formed with side frames  214  and  216  interconnecting rear transverse frame  218  and front transverse frame  220 . Side frames  214 ,  216  have rear pivot mounting members  222 ,  224  positioned near the rear and front pivot mounting members  226 ,  228  positioned near the front. 
         [0059]    Upper bunk assembly  230  including perimetrical frame  232  has top rear guardrail assembly  234  projecting upwardly from the rear and top side frames  236 ,  238  at the side forming a bunk enclosed on the sides and rear, but with the front open when in the lowered, seating, position, 
         [0060]    Pivotally connected to front pivot mounting members  226 ,  228  right and left front links  240 ,  242 . Similarly, pivotally connected to pivot mounting members  222 ,  224  are right and left rear links  244 ,  246 . 
         [0061]    In the down, or seating position, the bunk bed frame  230  is secured to the base frame  212  through the interaction of a lock assembly. In the embodiment show, lock plate  248 , engaged with lock plunger  250  engaging an aperture in plate  248 . Plate  248  is angled such that engagement of plunger  250  is essentially perpendicular to plate  248  and to the direction of motion of the frame  230  as it is raised. Plunger  250  can be cable actuated being interconnected to lock release  251 . Release  251  could be manually operated, pedal operated, electrically, pneumatically or hydraulically operated. Manual operation has advantages in the use of fewer and generally more reliable parts. Electrical operation, such as by a solenoid has advantages in the variable means for control whether by switch or data processing controller. 
         [0062]    After release  251  is actuated, plunger  250  disengages plate  248  thereby permitting upper bunk frame  230  to be lifted with the assistance of right and left gas cylinders,  252 ,  254  to bunk bed position  256 . 
         [0063]    Ladder  258  is, in this embodiment, part of the right side of front brace frame  260 . Frame  260  thus, has one ladder post at the right side and another post at the left side. Frame  260  is pivotally mounted to frame  212  so that it folds flat above mattress  290 . When bunk frame  230  is fully raised, frame  260  is deployed to as to latch to frame  260  thereby providing fixed vertical support. 
         [0064]    Front guard  262  is pivotally mounted to the front of frame  230  so that it can be stowed underneath when frame  230  is moved to and is in the sitting position, but can be rotated through substantially 270 degrees to provide a total of four guards around the perimeter of frame  230 . 
         [0065]    In particular, front link mounting strut  263  depends downwardly from frame  230  and in addition to providing structure to which front links  240 ,  242  are pivotally connected (there is a mounting strut  262  on each side of frame  230 ) additionally is structurally supportive of plate  248  and ladder locking mechanism  264 . Mechanism  264  I the embodiment uses projecting ladder locking tabs  266  which receive frame rod  268 . Other locking or other engagement mechanisms could also be used. 
         [0066]    The movement of assembly  230  using links  240 ,  242 ,  244  and  245  is controlled as bunk  230  moves slightly frontwardly and upwardly and then slightly rearwardly into a substantially vertically inline location above frame  212 . This is accomplished as links  240 ,  242 , rotate around front link top pivot  270  and front link bottom pivot  272  and links  244 ,  245  rotate around rear link top pivot  274  and rear link bottom pivot  276 . 
         [0067]    Movement is additionally controlled by links  240 ,  242 ,  244  and  245  having front timing arms  278 ,  279  and rear timing arms  280 ,  281  projecting downwardly, and generally perpendicularly although at a slightly obtuse angle. Arms  278 ,  279 ,  280  and  281  are themselves interconnected by timing links  282   283  that coordinate the rotation of links  240 ,  242 ,  244  and  245  as bunk  230  is raised or lowered. 
         [0068]    The interconnection links  240 ,  242 ,  244  and  245 , arms  278 ,  279 ,  280 ,  281  timing links  282   283  and pivots  270 ,  272 ,  274  and  276  enables the use of cylinders  252 ,  254  connected at cylinder upper pivot  284  and cylinder lower pivot  286  (each side having said pivots) so as to urge bunk  230  upwardly and permit downward movement for stowing in the seating position. 
         [0069]    Thus, a single gas cylinder  252 ,  254  on each side directly urges the rear link  244 ,  246  upward while resisting closing from a bunk position  256  to a seating position and the timing link and pivot arrangement transfers those forces to the entire linkage arrangement. Each link  244 ,  246  has a top pivot  274  (hidden in  FIG. 28 ) the rear link top pivot  274  connected directly to the bunk  230  using appropriate reinforcement and mounting members. 
         [0070]    The front link  240 ,  242  is connected to a front strut  260  depending downwardly from the bunk frame  230 . Strut  263  may be advantageously mounted in cooperation with components enabling both upward locking of brace frame  260  at locking mechanism  264  and incorporating downward locking such as lock plate  248 . 
         [0071]    Each of the front  240 ,  242  and rear  244 ,  246  links has a timing connection arm  278 ,  279 ,  280 ,  281  and the front  278 ,  279  and rear  280 ,  281  timing connection arms are interconnected by a timing link  282 ,  283 . As shown in  FIG. 30, 31 , fragmentary perspective views looking from the back toward the front at each back corner. Looking forwardly side frames  216 ,  214  support the lower portion of the linkage mechanism showing left and right rear links  246 ,  244  and left right front links  242 ,  240 , pivotally mounted at front link bottom pivot  272 L,  272 R and rear link bottom pivot  276  L,  276  R respectively. It will be noted that rear links  244 ,  246  can be advantageously formed from channel thereby permitting left right and gas cylinders,  254 ,  252  to be mounted within the flanges of the channel. Additionally, timing arms  278 ,  279 ,  280 ,  281  can be similarly formed, permitting the outer flanges to abut timing link,  283 ,  282  while the inner flanges permit spacing for timing link pivots  283  P,  282  P thereby providing clearance for operation while providing a more broad bearing arrangement for pivots  283  P,  282  P. Pivot mounting members  222 ,  224 ,  226 ,  228  can be configured as generally “U” shaped brackets providing similarly spaced bearing surfaces for the respective pivots they receive. A crossbar  296  interconnects the ends of left and right rear links  246 ,  244 . At the bottom of side frames  214 ,  216  appropriate members could be included such as flanges or braces  299  for mounting to a floor or deck. 
         [0072]    Electric motor actuation could also be used as shown in  FIG. 32 . An electric motor  312  could drive cables  314 ,  316  that operate a threaded thrust assembly  318 ,  320  or a rack arrangement that moves thrust member  322  which bears on arms  278 ,  279 . 
         [0073]      FIG. 34  shows an upholstered sofa  10  in bunk bed configuration. Right and left side frames  214  and  216  are upholstered as are top side frames  236 ,  238 . Top rear guardrail assembly  234  is covered and can receive removable seat back cushions which provide back support when in the seating position, with greater sleep area when removed. Seat cushions  292  can function as a sleep surface or they could be replaced with a stored mattress. The platform which supports the seat cushions and mattress could be formed with grid systems, convoluted springs hybrid grid and coil systems or springs such as are taught in U.S. Pat. No. 9,103,397 the disclosure of which is incorporated by reference as if fully set forth herein.