Abstract:
A futon frame features the use of a cam and journal system to move and to secure the back and the seat of the futon in a desired position. The cam and journal system provide the means to move the futon from a seat position to a bed position, and also provide the support mechanism to maintain the seat and back platforms in either position without the aid of any other locking mechanism or support arms. The cam and journal system consists of strategically placed cam and journals. The seat and back move in the cams by means of journals in predefined paths.

Description:
BACKGROUND OF THE INVENTION  
       [0001]     This invention relates generally to folding furniture. More specifically, this invention relates to futons that may be selectively positioned to function as a couch and a bed.  
       BACKGROUND OF THE INVENTION  
       [0002]     Recently, the demand for foldable futons has increased due to the flexibility of use in that these futons may function as either a sofa or a bed. The dual functionality of the foldable futons makes them both cost effective and space saving. Foldable futons abrogate the need to have a separate seat and bed.  
         [0003]     Currently, foldable futon frames are available in a variety of designs. For example, U.S. Pat. No. 5,303,432 to Fitts discloses a convertible futon frame that includes opposed end frames interconnected by front and back rails to define a rigid rectangular frame. Seat and back members are movably connected to the rectangular frame and to each other so that an individual can convert the frame between sitting and sleeping positions.  
         [0004]     U.S. Pat. No. 5,664,268 to Stoler et al. discloses a convertible futon frame which acts as both couch and bed, that includes two pad support members attached in a pivotal and displaceable fashion wherein the members allow for temporary locking and unlocking of the two pad support members to enable one of the pad support members to be temporarily used as a lever arm to move the other pad support member from a bed position to a back rest position.  
         [0005]     Convertible frames of the prior art often suffered from slipping of the seat with respect to the back during conversion of the futon from the bed position to the sitting position. This would then result in the need to exert the extra pushing force on the seat to firmly put the seat into a final seating place when the futon is placed in the sitting position.  
         [0006]     What is needed, therefore, is a convertible futon that requires less physical effort to convert between sitting and bed positions.  
       SUMMARY OF THE INVENTION  
       [0007]     A futon frame features the use of a detent that allows the seat and back platform to be rotated from the bed position to the sitting position at a predetermined angle without the need to exert an extra pushing force on the seat to firmly put the seat into a final seating place. The detent is mounted onto a force spreading mortise plate to make the conversion of the frame from the bed position to the sitting position much less physically demanding than in the comparable convertible frames of the prior art.  
         [0008]     The futon frame also employs the use of a cam and journal system to guide the movement of the seat and the back platforms when converting between sitting and bed positions and to secure the back and the seat platforms in a desired position. The cam and journal system provide the support mechanism to maintain the seat and back platforms in either position without the aid of any other locking mechanism or support arms.  
         [0009]     In a further embodiment, the cam and journal system may include low friction surfaces that reduces the physical effort required to move between the bed and sitting positions. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0010]      FIG. 1  is a perspective view of a futon frame in accordance with the present invention;  
         [0011]      FIG. 2  is an exploded perspective view of the futon frame shown in  FIG. 1 ;  
         [0012]      FIG. 3  is a plan view showing the cam and journal system contained within the frame;  
         [0013]      FIG. 4  is a plan view showing the side plank of the back platform;  
         [0014]      FIG. 5  is a plan view showing the side plank of the back platform, rotated 180°;  
         [0015]      FIG. 6  is a plan view showing the side plank of the seat platform;  
         [0016]      FIG. 7  is a plan view showing the complete cam and journal system;  
         [0017]      FIG. 8  is a plan view in which seat and folding platforms, shown in  FIG. 1 , are placed in an intermediate position to allow the futon frame to function as a seat;  
         [0018]      FIG. 9  is a plan view of a force spreading mortise plate with detent;  
         [0019]      FIG. 10  is a plan view showing the futon frame in the bed position;  
         [0020]      FIG. 11  is a plan view showing the seat platform and the back platform extending from each other in an unlocked position to initiate the process of converting the bed into a couch;  
         [0021]      FIG. 12  is a plan view showing the seat platform pivoted upward;  
         [0022]      FIG. 13  is a plan view showing the seat platform pivoted upward sufficiently high so as to form a lever type engagement with the bed platform;  
         [0023]      FIG. 14  is a plan view showing the seat platform being used as a lever to move the bed platform; and  
         [0024]      FIG. 15  is a plan view showing the futon frame in the sitting position. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0025]     Referring to  FIGS. 1 and 2 , a futon frame  10  includes a first and a second end frame  12  and  13 , respectively, and a pair of spaced-apart and parallel cross-members  14  extending along a width-wise direction, W, between the end frames  12  and  13 . End frame  12  contains one pair of legs  16   a  and  16   b.  End frame  13  contains one pair of legs  16   c  and  16   d.  End frames  12  and  13  are identical although mirror images. As such, the same reference numerals apply to the components of both, and only one will be described in detail.  
         [0026]     Futon frame  10  comprises four sides, shown as side  10   a,  side  10   b,  side  10   c,  and side  10   d.  Side  10   a  is disposed opposite to side  10   c  and side  10   b  is disposed opposite to side  10   d.  Side  10   a  and side  10   c  are disposed transversely to side  10   b  and side  10   d.    
         [0027]     Leg  16   a  extends from an arm-rest  18 , terminating in a foot member  20 , and positioned proximate to side  10   c.  Leg  16   b  extends from an arm-rest  18 , terminating in a foot member  20 , and positioned proximate to side  10   a.  The legs  16   a  and  16   b  of end frame  12  are spaced apart along a depth-wise direction, D, with the depth-wise direction, D, extending transverse to the width-wise direction, W. A support beam  22  is associated with end frame  12  and extends between the legs  16   a  and  16   b,  parallel to the depth-wise direction, D.  
         [0028]     Referring to  FIG. 3 , support beam  22  comprises four sides, three of which are shown as side  22   a,  side  22   b,  and side  22   c.  Side  22   b  is disposed opposite to side  22   c  and side  22   a  extends therebetween. Leg  16   a  comprises four sides, three of which are shown as side  17   a,  side  17   b  and side  17   c.  Side  17   b  is disposed opposite to side  17   c  and side  17   a  is disposed therebetween.  
         [0029]     Leg  16   a  comprises a recess disposed on side  17   a  defining a cam  220 . Cam  220  is arcuate in shape and concave with respect to leg  16   b.  Support beam  22  comprises a recess disposed on side  22   a  defining a cam  222 . Cam  222  has a linear slope and extends obliquely with respect to the horizontal axis h. Cam  222  extends from a region on side  22   a  proximate to side  22   c  away from leg  16   a  and terminates proximate to side  22   b.  Boundary  30 , shown in  FIG. 6 , comprises a recess defining a cam  224  facing support beam  22 . Cam  224  is oval in shape and is disposed proximate to leg  16   a.    
         [0030]     Referring to  FIGS. 3, 4 ,  5 , and  6 , journal  200  is disposed within cam  220 . Journal  200  is permanently attached to perimeter  44  but is allowed to roll within the recessed surface of cam  220 . Journal  202  is disposed within cam  222 . Journal  202  is permanently attached to perimeter  44  but is allowed to roll within the recessed surface of cam  222 . Journal  204  is disposed within cam  224 . Journal  204  is permanently attached to perimeter  44  but is allowed to roll within the recessed surface of cam  224 .  
         [0031]     Cam  220  is lined with a low friction surface to facilitate movement of journal  200 . Cam  222  is lined with a low friction surface to facilitate movement of journal  202 . Cam  224  is lined with a low friction surface to facilitate movement of journal  204 .  
         [0032]     Referring to  FIG. 3 , cam  220  contains a throughway  230  for ingress and egress of journal  200  within cam  220  for use of assembly and disassembly. Throughway  230  is located proximate to side  17   b  of leg  16   a  and extends from cam  220  to side  17   b  of leg  16   a.  Cam  222  contains a throughway  232  for ingress and egress of journal  202  within cam  222  for use of initial instillation and setup, as well as disassembly. Throughway  232  is located proximate to side  22   b  of support beam  22  and extends from cam  222  to side  22   b  of support beam  22 .  FIG. 7  shows the complete cam and journal system.  
         [0033]     Referring to  FIGS. 1 and 2 , the seat platform  24  includes a plurality of billets, the ends of which are coupled together, forming a boundary  30  enclosing a region  32 , and a plurality of slats  34 . Although the boundary  30  may be of any shape desired, it is preferred that boundary  30  have a rectangular region. To that end, the seat platform  24  includes four billets  36   a,    36   b,    36   c  and  36   d,  each of which includes opposed tip portions  38   a,    38   b,    38   c  and  38   d,  respectively. Billets  36   a  and  36   c  are spaced-apart and extend parallel to each other, with billets  36   b  and  36   d  extending transverse thereto. Billets  36   b  and  36   d  are spaced-apart and extend parallel to each other. The slats  34  extend between billets  36   b  and  36   d.  In this fashion, one of the opposed tip portions  38   a  of billet  36   a  is attached, using fasteners  45 , to a tip portion  38   b  of billet  36   b,  defining a union  40   a.  Although any type of fasteners may be employed, typically, fasteners  45  are wood screws. The remaining tip portion  38   a  of billet  36   a  is attached, using fasteners  45 , to a tip portion  38   d  of billet  36   d,  defining a union  40   d.  The tip portion  38   b,  disposed opposite to billet  36   a,  is attached, using fasteners  45 , to one of the opposed tip portions  38   c  of billet  36   c,  defining a union  40   b.  The remaining tip portion  38   c  of billet  36   c  is attached, using fasteners  45 , to one of the opposed tip portions  38   d,  disposed opposite to billet  36   a,  of billet  36   d,  defining a union  40   c.    
         [0034]     The back platform  26  includes a plurality of planks, which are attached together in a fashion similar to the billets,  36   a - 36   d  of the seat platform  24 , discussed above. Specifically, the ends of the planks are coupled together, forming a perimeter  44  enclosing an area  46 , and a plurality of panel-boards  48 . Although the area  46  may be of any shape desired, it is preferred that area  46  have a rectangular shape. To that end, the seat platform  24  includes four planks  50   a,    50   b,    50   c  and  50   d,  each of which includes opposed tip portions  52   a,    52   b,    52   c  and  52   d,  respectively. Planks  50   a  and  50   c  are spaced-apart and extend parallel to each other, with planks  50   b  and  50   d  extending transverse thereto. Planks  50   b  and  50   d  are spaced-apart and extend parallel to each other, with the panel-boards  48  extending therebetween. In this fashion, one of the opposed tip portions  52   a  of plank  50   a  is attached, using fasteners  45 , to a tip portion  52   b  of plank  50   b,  defining a junction  54   a.  The remaining tip portion  52   a  of plank  50   a  is attached, using fasteners  45 , to a tip portion  52   d  of plank  50   d,  defining a junction  54   d.  The tip portion  52   b,  disposed opposite to plank  50   a,  is attached, using fasteners  45 , to one of the opposed tip portions  52   c  of plank  50   c,  defining a junction  54   b.  The remaining tip portion  52   c  of plank  50   c  is attached, using fasteners  45 , to one of the opposed tip portions  52   d,  disposed opposite to plank  50   a,  of plank  50   d,  defining a junction  54   c.    
         [0035]     Referring to  FIGS. 1, 2 , and  8 , in the fully open position, seat and back platforms  24  and  26  lie in a common plane, with the angle therebetween, θ, measuring 180°. The back platform  26  rests against one of the pairs of cross-members  14 , and the seat platform  24  lies against the remaining cross-member  14 .  
         [0036]     Referring to  FIGS. 1, 2  and  9 , a force spreading mortise plate  250  is attached to futon frame  10  at desired locations to enhance the durability and functionality of futon frame  10 . For example, U.S. Pat. No. 6,108,833 to Grossman et al. discloses the use and placement of a force spreading mortise plate. The force spreading mortise plate  250  located on perimeter  44  contains a detent  252  used to help the user convert the futon frame  10  from the bed position to the sitting position. Detent  250  allows for rotation of the seat platform  24  coupled to back platform  26  when changing the futon from the bed position to the sitting position at a predetermined angle without the slipping of seat platform  24  with respect to back platform  26 . This slipping of seat platform  24  will cause seat platform  24  to extend past cross-member  14  when the futon is placed in the sitting position more than what is designed for. This will then necessitate the need to exert an extra pushing force to seat platform  24  to place seat platform  24  in the properly designed position when the futon is placed in the sitting position. Detent  252  allows for the absence of the need to exert an extra pushing force onto seat platform  24  to firmly put seat platform  24  into place.  
         [0037]     Referring to  FIG. 10 , when futon frame  10 , shown in  FIG. 1 , is disposed in the bed position, seat platform  24  and back platform  26  are placed horizontally next to each other with respect to the horizontal axis. Journal  200  is placed at the bottom of cam  220 . As a result of the fixed space relation of journal  200  with respect to journal  202 , journal  202  is placed at the front of cam  222 . For optimum comfort, seat platform  24  and back platform  26  should be placed touching next to each other. As a result of this, journal  204  is placed at the front of cam  224 .  
         [0038]     Referring to  FIG. 11 , when converting from the bed position to the seating position, a pulling force must be applied to the seat platform  24  to cause separation of seat platform  24  from back platform  26 . This will in turn cause journal  204  to be moved to the back of cam  224 . Referring to  FIG. 12 , an upward force then must be applied to seat platform  24  to lift it in the air about the axis as determined from the placement of journal  204  within cam  224 . Referring to  FIG. 13 , once seat platform  24  has been lifted in the air sufficiently high enough, seat platform  24  must be given a pushing force to cause seat platform  24  to be properly disposed underneath detent  252  located on the force spreading mortise plate  250 , which is in turn, located on back platform  26 . Referring to  FIG. 14 , after proper placement of seat platform  24  underneath back platform  26  and contact of seat platform  24  with detent  252 , a downward force must be applied to seat platform  24  causing seat platform  24  and back platform  26  to be positioned in the seating position.  
         [0039]     Referring to  FIG. 15 , when futon frame  10 , shown in  FIG. 1 , is positioned in the seating position, seat platform  24  and back platform  26  are positioned at a predefined angle therebetween,  6 , to each other. Journal  200  is placed at the top of cam  220 . As a result of the fixed space relation of journal  200  with respect to journal  202 , journal  202  is placed at the back of cam  222 . For locking of seat platform  24  and back platform  26 , journal  204  is placed at the front of cam  224 .  
         [0040]     If conversion of the futon frame  10  from the sitting position to the bed position is desired, a lifting force must be applied to seat platform  24  to cause rotation of seat platform in conjunction with back platform  26 , until back platform  26  is in the horizontal position. A pulling force must be applied to seat platform  24  to cause disengagement of seat platform  24  from back platform  26 . Seat platform  24  then can be rotated downward until seat platform  24  is in the horizontal position. A pushing force must then be applied to seat platform  24  to cause seat platform  24  to be placed horizontally next to back platform  26  for optimum comfort.  
         [0041]     To summarize, when futon frame  10  is positioned in the bed position, journal  200  is positioned at the bottom of cam  220 , journal  202  is positioned at the front of cam  222  and journal  204  is positioned at the front of cam  224 . When futon frame  10  is positioned in the seating position, journal  200  is positioned at the top of cam  220 , journal  202  is positioned at the back of cam  222  and journal  204  is positioned at the front of cam  224 .  
         [0042]     While this invention has been described with references to various illustrative embodiments, the description is not intended to be construed in a limiting sense. Various modifications and combinations of the illustrative embodiments, as well as other embodiments of the invention, will be apparent to persons skilled in the art upon reference to the description. It is, therefore, intended that the appended claims encompass any such modifications or embodiments.