Sofa convertible into bunk bed

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.

In accordance with the invention it is claimed: 
     
         1 . A sofa bed convertible into a bunk bed has a base frame assembly formed with side frames interconnecting a rear transverse frame and a front transverse frame, said base frame having a front and a back thereby respectively defining a front and rear of said frame assembly;
 said side frames have lower rear pivot mounting members positioned near the rear and lower front pivot mounting members positioned near the front of said side frames;   an upper bunk including a perimetrical frame has a bunk side frames and a top rear guardrail assembly projecting upwardly from said perimetrical frame and interconnecting said rear and top side frames,   thereby forming a bunk enclosed on the sides and rear, but with the front open when in a lowered, seating, position;   said lower front pivot mounting members pivotally connect to a front link and said lower rear pivot mounting members pivotally connect to a rear link at the respective bottom link pivots of each front and rear link; said bottom link pivots lie in different horizontal planes;   said upper bunk frame having placed thereon a front pivot mounting strut with an upper front pivot mount thereon and a rear pivot mount said upper pivot being pivotally connected to said front link and said rear pivot being pivotally connected to said rear link; said upper link pivots lie in different horizontal planes;   each of said front and rear links having a timing arm depending from said links proximate said bottom link pivots, such that said arms depend substantially vertically downwardly when said sofa has said bunk in a lowered position;   a timing link pivotally interconnecting said arms to one another;   said bunk being movable from said lowered position to an upper bunk bed position through movement controlled by said front, rear and timing links such that said bunk remains in a substantially horizontal position through its range of motion.   
     
     
         2 . The sofa of  claim 1  further comprising:
 movement of said bunk through operative interconnection of said links is controlled as said bunk moves from said lower position, slightly frontwardly and upwardly and then after passing a crest of forward movement, slightly rearwardly into a substantially vertically inline location above said frame at said upper position, through said front links rotating around said front link top pivot and said front link bottom pivot in time with said rear links rotating around said rear link top pivot and said rear link bottom pivot, said timing being additionally controlled by said front and rear links having said respective front and rear timing arms projecting downwardly, and generally perpendicularly at a slightly obtuse angle to said front and rear links, said arms being themselves interconnected by said timing links to coordinate the rotation of said front and rear links as said bunk is raised or lowered. 
 
     
     
         3 . The sofa of  claim 2  further comprising:
 said pivotally connected front, rear and timing links and arms, comprising a linkage in which a cylinder is connected at a cylinder upper to said rear link and a cylinder lower pivot at said lower side frame so as to urge said bunk upwardly and permit downward movement for stowing in a seating position said urging exerted by directly urging the rear link upward as the bunk is moved in that direction while resisting closing from a bunk position to a seating position by weight or imparted force, whereby said timing link and pivot arrangement transfers forces to the entire linkage. 
 
     
     
         4 . The sofa of  claim 2  further comprising:
 mechanical advantage is deploying said bunk from a sitting position to a bunk bed position, and resisting forces tending to impart lowering from said bunk bed position to said sitting position is accomplished by a mechanical apparatus bearing on said linkage comprising one of pneumatic cylinders, electric motors and power transmission; hydraulic motors and power transmission; cable operation. 
 
     
     
         5 . The sofa of  claim 2  further comprising:
 a pivoting brace and ladder assembly being mounted so as to substantially span said side frames and rest in a folded position when said bunk is in a sofa position and to deploy upwardly to support said bunk in a bunk bed position. 
 
     
     
         6 . The sofa of  claim 2  further comprising:
 said front link is connected to a front strut depending downwardly from a bunk frame; said strut being mounted to permit cooperation with components enabling both upward locking of said bunk frame by said brace and ladder assembly at a latching mechanism and incorporating downward locking such as lock plate which engages a lock plunger in a downward locking position; 
 said plunger is manually or automatically engageable and disengageable. 
 
     
     
         7 . The sofa of  claim 1  further comprising:
 front and rear timing connection arms are interconnected by a timing link; said side frames support a lower portion of a linkage mechanism with rear and front links pivotally mounted at a front link bottom pivot and a rear link bottom pivot respectively; said rear links are formed and arranged to permit gas cylinders to be recess mounted within the link structure; said timing arms are formed and arranged so as to permit a first member to abut said timing link and a second member to permit spacing for timing link pivots thereby providing clearance for operation while providing a more broad bearing arrangement for said pivots; pivot mounts being formed and arranged so as to provide spaced bearing surfaces for the respective pivots they receive; a crossbar interconnecting the ends of left and right rear links. 
 
     
     
         8 . The sofa of  claim 5  further comprising:
 said bunk bed frame is secured to said base frame through the interaction of said lock assembly in which said lock plate engages said lock plunger by said plunger engaging an aperture in said plate and in which said plate is angled such that engagement of said plunger is essentially perpendicular to plate and to the direction of motion of said bunk as it is raised said interaction accomplishing said release action by, after a release control is actuated, said plunger disengages said aperture thereby permitting said bunk to be lifted with the assistance of a mechanical advantage mechanism to said bunk bed position. 
 
     
     
         9 . The sofa of  claim 8  further comprising:
 said plunger is operated by one of cable actuation being interconnected to a manually operated lock release, cable actuation being interconnected to pedal operated lock release, an electrically actuated lock release, a pneumatically actuated lock release or a hydraulically actuated lock release. 
 
     
     
         10 . The sofa of  claim 5  further comprising:
 a front guard is pivotally mounted to the front of said bunk frame so that said guard can be stowed underneath when said bunk is moved to and is in the sitting position, but can be rotated through substantially 270 degrees so that, in combination with side and rear guards a total of four guards extends around the perimeter of said bunk frame enclosing it on three edges and substantially enclosing on the fourth. 
 
     
     
         11 . A sofa convertible into bunk bed comprising:
 a base frame assembly having a side frame;   an upper bunk frame;   a front link and a rear link rotatably connecting the base frame to the upper bunk frame such that the upper bunk frame elevates between a bunk bed position and a sofa position,   wherein the front link and the rear link rotatably connect the base frame to the upper bunk frame such that the upper bunk frame moves vertically while also remaining in a substantially horizontal orientation when the upper bunk frame elevates between the bunk bed position and the sofa position;   the front link includes a top pivot connected to the upper bunk frame and a bottom pivot connected to the side frame; and the rear link includes a top pivot connected to the upper bunk frame and a bottom pivot connected to the side frame;   a rear cylinder including an upper pivot pivotally connected to a median portion of the rear link and a lower pivot pivotally connected to a fixed location on the side frame.   
     
     
         12 . The sofa convertible into bunk bed of  claim 11 , further comprising:
 a ladder rotatably connected to the base frame and configured to be rotated to a vertical position and locked;   a front brace connected to the ladder and configured to be rotated to a vertical position and in conjunction with said ladder, and being locked with a locking mechanism.   
     
     
         13 . The sofa convertible into bunk bed of  claim 12 , wherein:
 the ladder rests over an upper portion of the base frame when in the sofa position, and rotates in a first direction to the vertical position;   a front guard mounted to said upper bunk frame so as to be stowable underneath said upper bunk frame and deployed outwardly and thence upwardly to lock in a vertical position;   said front guard rotates towards a second direction opposite the first direction.   
     
     
         14 . The sofa convertible into bunk bed of  claim 13 , further comprising
 a mattress positioned on the base frame; and one or more cushions positioned on the upper bunk frame, wherein the mattress and the cushions are arranged such that the mattress remains in the same position when the upper bunk frame is in the bunk bed position and the sofa position.   
     
     
         15 . A sofa convertible into bunk bed comprising:
 a base frame assembly having a side frame, the side frame having a pivot mount;   an upper bunk frame;   a front link and a rear link rotatably connecting the base frame to the upper bunk frame such that the upper bunk frame elevates between a bunk bed position and a sofa position;   wherein the front link includes a top pivot pivotally connected to the upper bunk frame and a bottom pivot pivotally connected to the side frame;   the rear link includes a top pivot pivotally connected to the upper bunk frame and a bottom pivot pivotally connected to the side frame.   
     
     
         16 . The sofa convertible into bunk bed of  claim 15  further comprising:
 a rear cylinder including an upper pivot pivotally connected to a median portion of the rear link and a lower pivot pivotally connected to a fixed location on the side frame. 
 
     
     
         17 . The sofa convertible into bunk bed of  claim 16  further comprising:
 a ladder rotatably connected to the base frame and configured to be rotated to a vertical position and locked; 
 a front brace connected to the ladder and configured to be rotated to a vertical position and locked with a locking mechanism. 
 
     
     
         18 . The sofa convertible into bunk bed of  claim 15  further comprising:
 Force is imparted to move said bunk bed from a sitting position to a bunk bed position and to resist lowering, by one of gas cylinders, electric motor and power transmission; cable actuation. 
 
     
     
         19 . The sofa convertible into bunk bed of  claim 17  further comprising:
 a lock mechanism for positively locking said bunk in a sitting position; 
 a latch mechanism for latching said ladder and brace in a bunk bed position. 
 
     
     
         20 . The sofa convertible into bunk bed of  claim 19  further comprising:
 said lock mechanism can be actuated by one of cable operated manual control, cable operated pedal control, electrical control, pneumatic control or hydraulic control.