Abstract:
A hinge assembly is mounted on a rail supported above a floor by two legs to support one end of a sofa/bed. A like hinge assembly is mounted the same way at the other end of the sofa/bed. The hinge assemblies include side rails supporting front and rear sofa frame members. Each hinge assembly combines front and rear pivot arms supporting a seat bracket, a backrest bracket and an intermediate hinge plate. A latch arm is pivoted to the seat bracket and received through a loop fastened on the intermediate hinge plate and on which a stop is provided. The latch arm is spring biased against the stop and includes a notch receivable in the stop to latch the arm. A latch dog is provided in the arm and which can be toggled between a position enabling latching of the arm against the stop, and a position enabling release of the arm from the stop. The organization of the components enables conversion of the sofa from a forward facing backrest configuration to a bed configuration to a rearward facing backresting configuration by merely handling the front edge of the seat in various movements upward and downward and without separate pull handles, knobs, cables, and without simultaneously or separately handling the backrest along with the seat.

Description:
BACKGROUND OF THE INVENTION  
         [0001]    1. Field of the Invention  
           [0002]    This invention relates generally to sofa-bed assemblies, and more particularly to such assemblies having particular versatility for use where available space is limited, such as in vehicles, for example.  
           [0003]    2. Description of the Prior Art  
           [0004]    Sofa-beds of various construction have been used for many years in mobile homes, recreational vehicles and other environments. Early examples enabled conversion of a unit between a seat configuration such as a sofa, and a flat configuration such as a bed. Typically, when in a seat configuration, they faced in one direction. Some have provided for easy access to storage space below the unit. An example is U.S. Pat. No. 5,787,522 issued to me on Oct. 4, 1998.  
           [0005]    More recently, an assembly has been developed which enables the conversion of a unit between a configuration of a seat facing in one direction, to a bed, to a seat facing in the opposite direction, with ability to access storage space beneath the assembly. Such arrangement is disclosed in U.S. Pat. No. 6,082,805 issued to me and Larry E. Gray on Jul. 4, 2000. While that assembly is very effective for its intended purpose, operation of it involves use of manually operated knobs or tabs, and associated cabling, to change configurations. It is an object of my present invention to provide similar versatility but without the use of cabling and associated manipulators.  
         SUMMARY OF THE INVENTION  
         [0006]    One aspect of the present invention is a method of converting a seating device from a seat with a forward facing backrest, to a bed and back to a seat by simply manually raising and moving the seat, without manual attention to any other features of the seating assembly and without knobs and cabling or the like. Another aspect of the invention is reconfiguring the seat assembly from a bed configuration to a rearward-facing backrest, and doing so without handling any portion of the assembly except for the seat, and without any cables or knobs or the like. A still further aspect of the invention is to enable access to storage space under the seat by simply raising the front edge of the seat and permitting it to latch in a storage access position, following which return to original position is again accomplished by simply manipulating the seat itself.  
           [0007]    A further aspect of the invention is a hinge assembly incorporating a seat carrier, a backrest carrier, a hinge carrier intermediate the seat and backrest carriers with pivotal connections to each, in combination with a latching arm on one of the carriers and a stop on the other carrier, and a linkage, the combination enabling the latching arm and stop to cooperate for enabling the locking of components in certain relationships and intentionally releasing the locking feature, all by moving the seat brackets in various ways.  
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0008]    [0008]FIG. 1 is a front perspective view of a multi-purpose seat assembly according to a typical embodiment of the present invention.  
         [0009]    [0009]FIG. 2 is an elevational view of the hinge assembly according to a typical embodiment of the present invention and in its configuration when the seat assembly is in the forward-facing sofa configuration shown in FIG. 1.  
         [0010]    [0010]FIG. 2A is an enlarged fragmentary elevational view of a portion of FIG. 2 and showing the latch arm and guide/stop.  
         [0011]    [0011]FIG. 2B is a section through the latch arm and stop taken at line  2 B- 2 B in FIG. 2A and viewed in the direction of the arrows.  
         [0012]    [0012]FIG. 3 is an elevational view of the hinge assembly when the front edge of the seat is raised for access to storage under the seat.  
         [0013]    [0013]FIG. 3A is an enlarged fragmentary elevational view of a latch arm and stop with the latch arm in position with the front end of a latch notch engaged with the stop.  
         [0014]    [0014]FIG. 4 is an elevational view of the hinge assembly as the front end of the seat is lifted and pulled forward to move the backrest forward toward a bed configuration.  
         [0015]    [0015]FIG. 5 is an elevational view of the hinge assembly as the backrest pivots down and the back return spring is nearing a low leverage, nearly neutral, position.  
         [0016]    [0016]FIG. 6 is an elevational view of the spring assembly when the backrest is down on a rear support on the side rail of the hinge assembly, and the return spring is in a low leverage position.  
         [0017]    [0017]FIG. 7 is an elevational view of the hinge assembly in which the front edge of the seat is raised further to further pivot the latch arm and to force a latch dog in the latch arm to ride over the top of the stop and enable the arm to receive the stop into a rear end of the notch, enabling the seat to be pushed down to bed position.  
         [0018]    [0018]FIG. 7A is an enlarged fragmentary elevational view of the condition of FIG. 7 with the latch dog riding over the stop as the latch arm moves upward.  
         [0019]    [0019]FIG. 8 is an elevational view showing the stop in the rear end of the notch.  
         [0020]    [0020]FIG. 8A is an enlarged fragmentary elevational view showing the stop in the rear end of the notch.  
         [0021]    [0021]FIG. 9 shows the assembly with the seat being lowered, reversing the latch dog to enable the latch arm to ride over the stop and avoid latching.  
         [0022]    [0022]FIG. 9A is an enlarged fragmentary elevational view of the latch arm as it has moved rearward and toggled the latch dog in a forward, notch-closing direction as the arm moved rearward over the stop in response to the seat being lowered.  
         [0023]    [0023]FIG. 10 shows is an elevational view of the hinge assembly showing the seat lowered all the way down onto the rest position supported by a front support on the side rail of the hinge assembly.  
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT  
       [0024]    For the purposes of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated device, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.  
         [0025]    Referring now to the drawings in detail, the FIG. 1 perspective view of the sofa assembly shows a seat  11 , backrest  12 , and legs  13 , four of which support the sofa above the floor  16 . The legs support two end members,  17  at one end of the sofa and  18  at the other end. These end members support side rails  19  and  21  on flanges  19 F and  21 F at opposite ends of the sofa. Each of the side rails has front and rear channels  22  and  23 , respectively, which receive front  24  and rear  26  sofa frame members. This configuration of the sofa assembly will be referred to hereinafter as the forward configuration, to distinguish it from an alternate configuration in which the backrest  12  is flat and the seat  11  is upright to serve as a backrest in a rear facing position.  
         [0026]    Many of the components of the hinge assembly according to the present invention, are most easily seen in the bed-forming configuration of FIG. 10. Each of the side rails serves as the base of a novel hinge assembly according to my present invention. This hinge assembly enables use of the sofa in the forward configuration, a bed configuration, or a rearward (backward) configuration. It also enables access to space below the seat by simply raising the seat to a storage access position, which is particularly advantageous if the sofa is provided with an enclosure around the storage space as in my U.S. Pat. No. 5,787,522 and suggested in U.S. Pat. No. 6,082,805 issued Jul. 4, 2000 to Larry E. Gray and me. The disclosures of those patents are incorporated herein to any extent which may be helpful.  
         [0027]    To facilitate understanding of the invention, the following description will focus on the hinge assembly at the far end of the sofa and will maintain the orientation of the side rail itself consistent in all views of the drawings. The hinge assembly at the near end of the sofa is a mirror image of that at the far end, so a separate description of it will not be needed.  
         [0028]    Referring to FIGS. 1, 2 and  10 , the seat  11  and backrest  12  can be of any of a variety of types of construction which are well known and widely used. Typically, they will include a generally rectangular tubular frame such as  31  with springing (not shown), which may be of a serpentine nature or some other well known type and covered with suitable padding and upholstery. In the case of the seat, the seat frame  31  is supported at its ends on seat carriers of the hinge assemblies. In the illustrated example the seat frame is attached to an inwardly projecting horizontal flange  32  of seat bracket  33  of the hinge assembly of this invention. Screws or bolts (not shown) are typically provided for this purpose. In the case of the backrest, it is typically constructed in the same manner as the seat, although usually (but not necessarily) of smaller height, and has less padding, and the frame  34  thereof is supported on backrest carriers of the hinge assembly. For the illustrated example, the frame  34  of the backrest is secured to an inwardly projecting flange  36  of backrest bracket  37  of the hinge assembly. As in the case of the seat, the attachment may be by screws, bolts or other means.  
         [0029]    The above-mentioned brackets are connected to the frame side rail  21  by a front pivot arm  38  and a rear pivot arm  39 . The front pivot arm is pivotally pinned to the side rail at  41  and to the seat bracket  33  at  42 . The rear pivot arm  39  is pivotally pinned to the side rail  21  at  43  and to the backrest bracket  37  at  44 . The pivot arms are connected to each other by a cross link  46 , which is pivotally pinned to the front pivot arm at  47  and to the rear pivot arm at  48 . An intermediate hinge carrier shown in the form of hinge plate  49  is pivotally pinned to the backrest bracket at  51  and to the seat bracket and front pivot arm at  52 . A latch arm  53  is pivotally pinned to the seat bracket at  54 . It is received through a guide  56  which is affixed to the hinge plate  49  and, as best shown in FIGS. 2A and 2B, has somewhat the appearance of a staple although, of course, without any prongs. In addition to serving as part of the guide  56 , the bottom portion  56 A thereof also serves as a stop for a latch, as will be described here.  
         [0030]    The latch arm is shown in the form of a generally channel-shaped stamping having a downwardly opening latch notch  57  near its rear or distal end  58 . The notch has a front end  59  of semi-circular configuration and a rear end  61  of semi-circular configuration. The latch arm also has a latch dog  62  pivotally pinned to it at  63 .  
         [0031]    Referring to FIG. 2A, the arm  53  is spring loaded by a spring  54  wound around pin  64  and having one end  64 A bearing down on the top of top flange  53 T of the arm. The other end  64 B of the spring bears on the rear edge  33 R of the seat bracket  33 . The spring  54  is stressed such that it is trying to open up, which results in the end  64 A bearing down in the direction of arrow  66  (FIG. 2A). The counterclockwise movement of the latch arm about the pivot pin  54  which would otherwise be imparted by the unwinding of spring  64 , is stopped by the bottom flange  53 B of the arm bearing on the top of the stop portion  56 A of the guide  56 . The spring biases the arm in the counterclockwise direction at all times, so that whenever the position of the arm on the stop has moved to a position of registry of the notch  57  with the stop  56 A, the arm will tend to pivot counter clockwise and receive the stop  56 A somewhere in the notch  57 .  
         [0032]    As mentioned above, the latch dog  62  is pinned at  63  in the arm  53 . The latch dog is free to move about the pivot pin  63  with its clockwise limit relative to the arm shown in the dashed line in FIG. 2A and its counterclockwise limit shown by the solid line in FIGS. 2, 2A,  9 ,  9 A and  10 .  
         [0033]    A backrest return spring  67 , with a rear end connected to the side rail  21  at  68 , and a front end connected to the front pivot arm  38  at  69 , is always in tension, tending to hold the backrest in the forward facing position. The amount of tension depends on the relative positions of the hinge assembly components as they affect the position of the front pivot arm about pin  41 .  
       Procedure  
       [0034]    The hinge assembly at the far end of the sofa has been described, and with the understanding that the assembly at the near end of the sofa is a mirror image thereof and operates in the same way, the procedure for converting a forward facing sofa to a bed and to a sofa with a rearward facing backrest and back to original sofa condition, will be described now.  
       Sofa Condition—Forward Facing Backrest, Converting to Bed  
       [0035]    To make the sofa into a bed, lift the front edge  1 F of the seat up. The latch arm  53  is pulled forward and upward and, being spring-loaded counterclockwise, the latch arm slides along the stop  56 A until the front end  59  of the latch notch  57  gets to the stop  56 A. Meanwhile, latch dog  62 , being pinned at a location remote from the tip  62 T, and hanging from it, may turn clockwise relative to the arm, due to the weight of the latch dog itself, virtually all of which is below the pivot pin  63 . In any event, when the projecting tip  62 T of the latch dog reaches the stop  56 A, the stop will push the latch dog clockwise, while the counterclockwise spring bias on the arm will force it downward and, with the latch dog tip  62 T pointed down, the front end of latch notch drops onto stop  56 A and arm  53  is thereby latched in its first position relative to the latch plate (FIG. 3). As the seat continues to be pulled upward and forward, the combination of the hinged connection of the seat bracket to the hinge plate at  42 , and the latch arm latched to the stop  56 A, causes the front pivot arm  38  to be pulled forward (FIG. 4). This action, through the connection of the hinge plate to the backrest bracket at  51 , causes the backrest bracket to be pulled forward (FIG. 4) against the resistance of the return spring  67 , which is being stretched during this operation. Further forward pulling of the front edge of the seat, and the relationship of the pivot arms and pivot pins  42  and  44  thereof to the seat bracket  33  and backrest bracket  37 , respectively, and the cross link  46  to the two pivot arms, has initially depressed the backrest pivot point  51  but is now causing it to rise as in FIG. 5, which has begun to move the backrest toward a horizontal position. Further forward pulling of the front edge of the seat pulls the backrest further forward and down to a horizontal position shown in FIG. 6, whereupon the frame  34  of the backrest comes to rest on top of a support shelf  71  on the frame side rail  21 . At this point and, as shown in FIG. 6, the return spring  67  is virtually horizontal and at an extremely low leverage position on the front pivot arm  38 . The weight of the backrest will thus keep the assembly in this configuration. Then, to move the seat portion downward to finish the bed, the front edge of the seat is lifted to move it upward slightly. The latch dog  62  cannot turn farther clockwise relative to the latch arm  53  because it is abutting the undersurface of the top flange of the latch arm. Therefore, the latch dog  62 , being forced upward against the spring loading of the arm as it passes stop  56 A (FIGS. 7, 7A), pushes the arm clockwise slightly against the loading of spring  64  until the latch dog tip  62 T rides over (FIGS. 7, 7A) stop  56 A and exposes the rear end  61  of the latch notch to the stop  56 A, whereupon the arm snaps down to receive the stop  56 A in the rear end of the notch (FIGS. 8, 8A). As this occurs, the cam surface  62 C of latch dog  62  bearing on the stop  56 A, is turned counterclockwise relative to the arm  53 , whereby it closes the front end of the notch as it did initially in FIG. 2, and tip  62 T projects slightly below the bottom surface  53 B of latch arm  53 . Then, upon pushing the front edge of the seat down, cam surface  62 C of the latch dog engaging stop  56 A cams the arm against loading of spring  64  in clockwise direction relative to pivot  54  and seat bracket  33 . Thereby the cam surface cams the arm outward from the stop  56 A and enables the latch arm (FIG. 9) to slide over the latch dog tip  62 T and rearwardly through the guide as the front edge of the seat is lowered to place the seat frame on top of the support shelf  72  to support the seat. Now the assembly is in the bed configuration.  
       Bed Configuration to Rearward Facing Sofa Configuration  
       [0036]    For this procedure, it is only necessary to start with a sofa configuration and pull up the front edge of the seat portion until the latch arm sliding along the stop  56 A gets the front end of the notch  57  to the stop  56 A, whereupon the arm will drop and latch the seat, now in the generally upright position to serve as a backrest. Note that this position happens to be the same as the seat position before the last step converting to the bed configuration.  
       Backward Sofa Configuration to Forward Sofa Configuration  
       [0037]    To return from the backward facing sofa configuration, it is only necessary to return first to the sofa configuration by simply pushing or pulling up on the front edge of the seat to allow the latch arm to receive the stop in the rear end of the notch and continue to raise and move backward on the front edge of the seat and allow it to return under the urging of the return spring so the backrest is automatically moved up to the forward facing position aided by the return spring  67 . Then the front edge of the seat is moved downward, the downward force pivoting the latch counterclockwise, as discussed above, enabling the arm  53  to move rearward through the guide, whereby the seat can be lowered to its original sofa position (FIGS. 1 and 2).  
       Sofa Condition—Forward Facing Backrest—Access to Storage  
       [0038]    For access to storage under the sofa seat  11 , the same procedure is followed as the first step to convert to a bed. However, the seat is raised no further than necessary to have the latch arm latch in the forward end of the notch. To close, the front edge of the seat is lifted slightly upward and rearward, enough to cause the latch dog tip  62 T to ride over the stop  56 A which turns the latch dog counterclockwise, and enables the rear end  61  of the latch notch to engage the stop. Then the seat can be pushed down, whereupon the arm is cammed outward and rides over the stop  56 A and slides rearward through the guide, thereby enabling the seat to be lowered to the sofa position.  
         [0039]    It may be seen from the foregoing description that the present invention enables construction of a seating assembly having great versatility but requiring no pull handles, knobs, cables, cords, or rods. It is not necessarily limited to a use in various types of land, water or airborne vehicles, as it may find use in space craft or in stationary settings. Also, it is not limited to a sofa size, as it could be used for a seat or bed for one person.  
         [0040]    While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only the preferred embodiment has been shown and described and that all changes and modifications that come within the spirit of the invention are desired to be protected.