the detailed description set forth below in connection with the appended drawings is intended as a description of the presently preferred embodiments of the invention , and is not intended to represent the only form in which the present devices may be developed or utilized . it is to be understood , however , that the same or equivalent functions may be accomplished by different embodiments that are also intended to be encompassed within the spirit and scope of the invention . it is further understood that the use of relational terms such as first , second , and the like are used solely to distinguish one from another entity without necessarily requiring or implying any actual such relationship or order between such entities . referring now to the drawings , wherein the showings are for purposes of illustrating preferred embodiments of the present invention only , and not for purposes of limiting the same , there is shown a sleeper sofa 30 which includes a sofa frame 20 , a main support frame 17 coupled to the sofa frame 20 , and a bed frame 1 moveably connected to the main support frame 17 . the bed frame 1 generally includes two pivotal sections 32 , 34 ( see fig5 - 7 ) which pivot about a hinge 9 between a retracted position ( see fig6 ), and an extended position ( see fig7 ). as will be explained in more detail below , in the retracted position , the two sections 32 , 34 of the bed frame 1 assume an angled configuration relative to each other , whereas in the extended position , the two sections 32 , 34 assume a generally co - planar position relative to each other . the sofa frame 20 , main support frame 17 , and bed frame 1 are all configured to allow for quick and easy transition of the bed frame 1 from the retracted position to the extended position , and vice versa . the pivotal movement of bed frame 1 about a single pivotal axis ( e . g ., defined by hinge 9 ) allows the bed frame 1 to easily transition between the retracted and extended positions , simply by pulling the bed frame 1 away from the sofa frame 20 ( for extension ) or pushing the bed frame 1 toward the sofa frame 20 ( for retraction ). the drawings depict an exemplary embodiment of the sofa frame 20 and the main support frame 17 . the sofa frame 20 includes a first arm portion 36 , an opposing second arm portion 38 , and a backrest portion 40 extending between the first and second arm portions 36 , 38 . seat cushions 25 and back cushions 27 may be placed between the first and second arm portions 36 , 38 . the main support frame 17 includes a rear support member 42 and a pair of arm support members 44 , 46 connected to opposed end portions of the rear support member 42 . the rear support member 42 is positioned adjacent the backrest portion 40 of the sofa frame 20 , while the pair of arm support members 44 , 46 are connected to respective ones of the pair of first and second arm portions 36 , 38 . the pair of arm support members 44 , 46 may be similarly configured to include a bracket 23 having apertures , slots or the like to accommodate nails , screws , rivets or other mechanical fasteners for securing the arm support members 44 , 46 to the first and second arm portions 36 , 38 . the main support frame 17 further includes a forward support member 48 and a pair of lateral support members 50 , 52 extending from opposed end portions of the forward support member 48 to the rear support member 42 . a pair of connector members 10 extend between respective ones of the lateral support members 50 , 52 and the first and second arm support members 46 , 44 . a plurality of legs 15 are connected to the main support frame 17 to elevate the main support frame 17 above a lower support surface , such as a floor . the plurality of legs 15 are preferably spaced about the main support frame 17 to provide balanced support to the main support frame 17 . furthermore , the exemplary embodiment shows four ( 4 ) legs 15 , although fewer than four or more than four support legs 15 may be used , depending on the size , shape and configuration of the sleeper sofa 30 . one or more bed frame supports 5 is connected to the main support frame 17 to support the bed frame 1 when the bed frame 1 is in the extended position . the bed frame supports 5 are preferably positioned over the legs 15 to efficiently transfer the load from the bed frame supports 5 to the legs 15 , and thereby mitigate load transfer through the main support frame 17 . referring now to fig5 , there is shown a partial view of the sofa frame 20 , with the main support frame 17 being connected to the sofa frame 20 . the bed frame 1 is also shown detached from the main support frame 17 and the sofa frame 20 . with the particulars of the main support frame 17 and sofa frame 20 being described above , the following discussion will focus on the features of the bed frame 1 . the bed frame 1 includes the first section 32 and second section 34 pivotal relative to each other about the hinge 9 . each section 32 , 34 is defined by a generally quadrangular frame having generally rounded corners . in the exemplary embodiment , the first section 32 includes a larger frame which defines a depth that is larger than the frame of the second section 34 . according to one embodiment , the first and second sections 32 , 34 are pivotable relative to each other between a retracted position and an extended position . due to the size and configuration of the first and second sections 32 , 34 , the bed frame 1 is pivotable about a single axis as the bed frame 1 pivots between the retracted and extended positions . furthermore , the bed frame 1 is preferably configured and adapted such that the first and second sections 32 , 34 pivot less than ninety degrees relative to each other as the bed frame 1 transitions between the retracted and extended positions . in this regard , the bed frame 1 does not fold with one section overlapping the other as the bed frame 1 transitions to the retracted position , which is distinct from conventional , “ accordion - type ” sleeper sofas . the first and second sections 32 , 34 also include a plurality of slats 7 which collectively form a deck and act as a support for a mattress disposed thereon . as shown , the slats 7 extend in a transverse direction across the respective frame . each section 32 , 34 include a plurality of slat supports 24 for connecting the slats 7 to the respective frame . the slats 7 may be connected to the slat supports 24 via rivets 16 or other mechanical fasteners known by those skilled in the art . the bed frame 1 further includes a plurality of wheels 13 connected thereto to allow the bed frame 1 to be easily transitioned between the extended and retracted positions . according to one embodiment , the wheels 13 are connected to the first section 32 via respective metal wheel supports 14 . the wheels 13 may define various sizes , although in a preferred embodiment , the wheels are approximately 5 inches in diameter . the wheels 13 are preferably grouped in pairs , wherein the wheels 13 in a given pair are aligned along a common axis ( i . e ., roll along a common axis ) which extends generally transverse to the first section 32 . furthermore , the wheels 13 in a given pair are connected via a wheel cart frame 4 which extends between the wheels 13 in the respective pair . each wheel cart frame 4 connects a pair of wheels 13 together to facilitate steering of the bed frame 1 in and out of the sofa frame 20 . furthermore , the wheel cart frame 4 supports the weight of an individual sitting bed frame 1 when the bed frame 1 is in the retracted position , or lying on the bed frame 1 , when the bed frame 1 is in the extended position . the wheels 13 allow the bed frame 1 to easily glide between the retracted and extended positions . the underside of the bed frame 1 includes a frame support 18 and lock members 11 connected to the frame support 18 . the lock members 11 lock the bed frame 1 in place relative to the main support frame 17 to mitigate unwanted movement of the bed frame 1 . when the bed frame 1 is in the retracted position , at least one of the lock members 11 engaged with the forward support bar 48 of the main support frame 17 . in this regard , the lock member 11 defines a contact surface which rests on the main support frame 17 when in the locked position and prevents transverse movement of the bed frame 1 relative to the main support frame 17 . to unlock the bed frame 1 from the main support frame 17 , the user lifts the front end portion of the first section 32 , which causes disengagement of the lock member 11 from the main support frame 17 . one or more restriction bars 3 may be connected to the first section 32 to keep the bed frame 1 in the generally horizontal position , i . e ., to prevent a user from lifting the first section 32 too much when unlocking the bed frame 1 from the main support frame 17 . the sofa 30 further includes a movement assembly which aids in the movement of the bed frame 1 between the extended and retracted positions relative to the sofa frame 20 and main support frame 17 . the movement assembly includes a guide post 2 and a guide wheel 29 connected to the guide post 2 via a fastener 27 . the guide post 2 is connected to the second section 34 of the bed frame 1 and extends slightly outward therefrom in a lateral direction . referring now to fig8 - 9 , the movement assembly further includes a guide plate 8 having a guide slot 56 formed therein . the guide post 2 extends within the guide slot 56 and guides the guide post 2 , and in turn , the second section 34 of the bed frame 1 during movement of the bed frame 1 between the retracted position and extended position . the guide slot 56 defines a generally arcuate configuration , which corresponds to the raising / lowering of the end portion of the second section 34 as the bed frame 1 transitions between the retracted and extended positions . more specifically , when the bed frame 1 moves from the retracted position to the extended position , the end portion 58 of the second section 34 is lowered . conversely , when the bed frame 1 moves from the extended position to the retracted position , the end portion 58 of the second section 34 is raised . fig6 and 7 further show a front panel 60 to the sofa frame 20 . the front panel 60 generally extends between the first and second arms portions 36 , 38 . the front panel 60 is connected to the bed frame 1 via front panel connectors . with the basic structural features of the sleeper sofa 30 being described above , the following section offers a more detailed discussion of the transition of the sofa 30 between the retracted and extended position . fig8 shows the sleeper sofa 30 in the retracted position , which is typically used for sitting on the sleeper sofa 30 . when in the retracted position , the first and second sections 32 , 34 of the bed frame 1 are angularly disposed relative to each other . the second section 34 extends upwardly into a cavity 62 in the sofa frame 20 behind the backrest portion 40 thereof . in particular , the cavity 62 may be at least partially defined by backrest wall 65 , top wall 67 and rear wall 69 . furthermore , in the exemplary embodiment , the front panel 60 is substantially flush with the end faces of the first and second arm portions 36 , 38 . at least one lock member 11 is also engaged with the forward support member 48 of the main support frame 17 to prevent unwanted movement of the bed frame 1 when the bed frame 1 is in the retracted position ( i . e ., to keep the bed frame 1 from sliding forward ). to unlock the bed frame 1 , the user lifts on the forward end thereof to disengage the lock member 11 from the main support frame 17 . the fig2 shows a strap 64 which may be disposed adjacent the forward end 66 to aid in lifting the forward end portion 66 . the bed frame 11 is pulled forward slightly and then the user lowers the forward end portion 66 so all of the wheels 13 are engaged with the floor surface . the user may then pull out the forward end portion 66 until the bed frame 1 is in the extended position . in the completely extended position , the first and second sections 32 , 34 of the bed frame 1 are generally coplanar relative to each other . furthermore , the guide post 2 reaches a terminal end of the guide slot 56 to prevent further advancement of the bed frame 1 . with the bed frame 1 in the extended position , a user ( s ) may lie on the sleeper sofa in a manner similar to a bed . the specific size and configuration of the sleeper sofa may allow the user ( s ) to lie on the bed in several different positions . for instance , the user may lie in a direction substantially perpendicular to the direction of extension of the bed frame 1 ( i . e ., with the user &# 39 ; s head and feet disposed adjacent the first and second arm rest portions 36 , 38 ). in this regard , the bed frame 1 may not require a great deal of extension from the retracted position to accommodate the user . this may be desirable for hotels and cruise ships , where excess space in front of the sleeper sofa may not be readily available . alternatively , it is understood that various embodiments of the sleeper sofa 30 may allow the user to lie in a direction substantially parallel to the direction of extension of the bed frame 1 from the retracted position to the extended position ( i . e ., with lying in a position wherein the user &# 39 ; s head or feet extends away from the sofa frame 20 ). to move the bed frame 1 back to the retracted position from the extended position , the user simply pushes the bed frame 1 back toward the sofa frame 20 . as this occurs , the guide post 2 moves back through the guide slot 56 , thereby lifting the end portion 58 of the second section 34 of the bed frame 1 . to complete the transition to the retracted position , the user lifts the forward end portion 66 of the first section 32 to engage the lock member 11 with the forward bar of the main support frame 17 . thus , the bed frame 1 easily transitions between the retracted and extended positions via a smooth gliding motion which is facilitated by the wheels 13 . unlike conventional sleeper sofas , which generally include a complex , folded , articulating skeleton , the sleeper sofa 30 described herein is simple and easy - to - use . the only articulating motion is the present sleeper sofa 30 is the pivoting movement of the second section 34 relative to the first section 32 as the bed frame 1 moves between the retracted and extended positions . such pivotal movement is typically concealed within the sofa frame 20 . indeed , the first section 32 of the bed frame 1 remains substantially in a common plane as it transitions between the retracted and extended positions . in this regard , the bed frame 1 is not folded to overlap with itself , as is common in conventional sleeper sofas . therefore , the sleeper sofa 30 is very simple and easy - to - use . the ease in transitioning the sleeper sofa 30 between the retracted and extended positions may facilitate cleaning of the sleeper sofa , as the bed portion may be easily accessed through the simple transition of the sofa from the retracted position to the extended position . after the portion is cleaned , the sleeper sofa may be easily transitioned from the extended position back to the retracted position . thus , the ease in cleaning the sleeper sofa 30 may make various implementations of the sleeper sofa 30 suitable for the hotel industry and cruise industry , where sleeper sofas are readily used and cleaned on a regular basis . furthermore , the likelihood of injury associated with operation of the sleeper sofa 30 is significantly reduced as compared to conventional sleeper sofas due to substantially concealed nature of the pivotal movement , and the simple transitional movement of the bed frame between the retracted and extended positions . moreover , the weight of the bed frame 1 is substantially supported throughout the transition between the retracted and extended positions , as the wheels 13 remain on the floor during most of the transition . the only lifting that occurs is the minimal lifting of the forward end portion 66 to unlock the bed frame 1 from the main support frame 17 . otherwise , the bed frame 1 is supported by the wheels 17 and not by the user . fig1 depicts an exemplary embodiment of a three cushion sleeper sofa incorporating the features described herein . those skilled in the art will readily understand that the dimensional information presented in the figures are exemplary in nature only and are not intended to limit the scope of the present invention . along these lines , other furniture pieces defining different dimensional characteristics may be fabricated which incorporate one or more aspects of the present invention described herein . fig1 - 17 are photographs of a sleeper sofa defining a chaise - like configuration , which is adapter to include the features described herein . the primary distinction between the sofa depicted in fig1 - 17 and the sofa shown in fig1 is that the height of one of the arm sections has been reduced such that is it flush with the top surface of the mattress pad . additional modifications and improvements of the present invention may also be apparent to those of ordinary skill in the art . thus , the particular combination of components and steps described and illustrated herein is intended to represent only certain embodiments of the present invention , and is not intended to serve as limitations of alternative devices and methods within the spirit and scope of the invention .
there is provided a sleeper sofa including a sofa frame , a main support frame , and a bed frame engageable with the sofa frame and main support frame . the sofa frame includes first and second arm portions , and a backrest portion extending therebetween . the main support frame is connected to at least one of the first and second arm portions to fixedly connect the main support frame to the sofa frame . the bed frame includes a first section and a second section pivotally connected to the first section via a hinge . the sleeper sofa further includes a guide plate defining an arcuate guide slot , which communicates with a guide post connected to the second section of the bed frame . the guide post travels in the guide slot to lower and raise the second section of the bed frame as the bed frame moves between the retracted and extended positions .