Convertible sofa

Abstract

The present invention is for a method of converting a standard jack knife hinge into a new hinge, which allows access to a storage area underneath the seat bottom while retaining the ability to be used as a sofa and a bed. The new hinge is created by removing the seat bottom frame from the seat bottom bracket, fixably attaching a first attachment bracket to the seat bottom frame, pivotally attaching the first attachment bracket to a second attachment bracket, and fixably attaching the seat bottom bracket and the second attachment bracket to the seat base frame. The present invention also claims the finished combined hinge as well as a convertible sofa utilizing the new hinge.

Description

FIELD OF THE INVENTION

[0001] This invention relates to a convertible sofa and, more particularly, to a convertible sofa or seat for use on recreational vehicles which can be converted from a seat to a bed.

BACKGROUND OF THE INVENTION

[0002] In many recreational vehicles today, it is common to have a convertible sofa or seat bed, which can function as a seat, a sofa, or a bed. Such seats are typically employed on recreational vehicles, but can also be used in extended cab pickups, vans, and minivans. The seat is often configured to fold into a flat, planar configuration for use as a bed, and then fold at a juncture between the seat bottom and the seat back so as to form a seat or sofa. The prior art seats have accomplished this versatility by the use of a standard jack knife hinge, which is shown in FIGS. 1 and 2 and will be discussed in detail below.

[0003] It is also common in recreational vehicles today to optimize the available space therein for maximum possible usage. Given the economic and fuel efficiency drawbacks of increasing the size of the vehicle, manufacturers are continually redesigning vehicle ergonomics to take maximum advantage of available interior space. One prior art device comprises a seat wherein the seat bottom can be folded parallel to the seat back to increase the storage space of the vehicle and to access a space provided below the seat. However, this prior art design has several limitations. It does not allow the seat back to fold over the seat bottom to allow greater access behind the seat back or to allow more room for storage. This prior art design also requires the use of a hinge plate between the seat and the seat back making the construction relatively complex and, possibly, allowing accidental insertion of fingers, which can cause serious injury. This prior art design also cannot be easily retrofitted, as it requires replacement of the standard jack knife design.

SUMMARY OF THE INVENTION

[0004] The convertible sofa of this invention provides a simple seat bottom hinge and seat back hinge, which are designed to be used in combination with a standard jack knife hinge. The new invention will allow the seat bottom to be rotated upwards and generally parallel to the seat back in order to increase the storage space of the vehicle and to provide access to a space provided below the seat. The new invention will also allow normal operation of the standard jack knife hinge, which allows the sofa to be converted into a bed when the seat bottom is down.

[0005] These and other advantages are provided by a method of making an improved convertible sofa hinge from a standard convertible sofa jack knife hinge. The jack knife hinge connects a seat back frame and a seat bottom frame to a seat base frame including a side rail. The jack knife hinge has a seat back bracket fixably connected to the seat back frame, a seat bottom bracket fixably connected to the seat bottom frame, the seat back bracket pivotally connected to the seat bottom bracket, a first pivot arm pivotally connected to the side rail and the seat back bracket, a second pivot arm pivotally connected to the side rail and the seat bottom bracket, and the cross bar arm pivotally attached to the first pivot arm and the second pivot arm. The method of making the an improved convertible sofa hinge comprises the steps of: a) removing the seat bottom frame from the seat bottom bracket; b) fixably attaching a first attachment bracket to the seat bottom frame; c) pivotally attaching the first attachment bracket to a second attachment bracket; and d) fixably attaching the seat bottom bracket and the second attachment bracket to the seat base frame.

[0006] These and other advantages are also provided by a hinge assembly for a convertible sofa, wherein the hinge connects a seat back frame and a seat bottom frame to a seat base frame including a side rail. The hinge for a convertible sofa comprises a seat back bracket fixably connected to the seat back frame, a seat bottom bracket pivotally connected to the seat back bracket, a first pivot arm pivotally connected to the side rail and the seat back bracket, a second pivot arm pivotally connected to the side rail and the seat bottom bracket, a cross bar arm pivotally attached to the first pivot arm and the second pivot arm, a first attachment bracket fixably attached to the seat bottom frame, and a second attachment bracket pivotally attached the first attachment bracket. The seat bottom bracket and the second attachment bracket are fixably attached to the seat base frame.

[0007] These and other advantages are also provided by a convertible sofa comprising a seat back frame, a seat bottom frame, and a seat base frame including a side rail on opposite sides of the seat base frame wherein the seat base frame encloses a storage area. The sofa further comprises a pair of hinges connecting the seat back frame and the seat bottom frame to the seat base frame. Each hinge comprises a seat back bracket fixably connected to the seat back frame, a seat bottom bracket pivotally connected to the seat back bracket, a first pivot arm pivotally connected to the side rail and the seat back bracket, a second pivot arm pivotally connected to the side rail and the seat bottom bracket, a cross bar arm pivotally attached to the first pivot arm and the second pivot arm, a first attachment bracket fixably attached to the seat bottom frame, and a second attachment bracket pivotally attached the first attachment bracket. The seat bottom bracket and the second attachment bracket are fixably attached to the seat base.

[0008] These and other advantages of this invention will become apparent upon a reading of the following description.

BRIEF DESCRIPTION OF THE DRAWING

[0009] A preferred embodiment of the invention has been depicted for illustrative purposes wherein:

[0010] FIG. 1 is a side elevational view of a prior art convertible sofa utilizing a standard jack knife hinge assembly shown in the seat position with portions shown in section and the cushions shown in broken lines for purposes of illustration.

[0011] FIG. 2 is a perspective view of the prior art convertible sofa of FIG. 1 shown in the bed position;

[0012] FIG. 3 is an exploded perspective view of a seat bottom hinge assembly of the present invention;

[0013] FIG. 4 is an assembled perspective view of the seat bottom hinge assembly shown in FIG. 3;

[0014] FIG. 5 is a partially exploded perspective view of the seat bottom hinge assembly attached to the seat bottom frame assembly over top of a seat frame assembly including a jack knife hinge assembly;

[0015] FIG. 6 is a perspective view of the seat bottom hinge assembly attached to the seat bottom frame assembly;

[0016] FIG. 7 is a perspective view of an embodiment of the convertible sofa utilizing the seat bottom hinge assembly of the present invention shown in a sofa or seat configuration;

[0017] FIG. 8 is a perspective view of an embodiment of the convertible sofa utilizing the seat bottom hinge assembly of the present invention shown in a lifted seat bottom configuration;

[0018] FIG. 9 is an exploded perspective view of a seat back hinge assembly of an embodiment of the present invention;

[0019] FIG. 10 is an assembled perspective view of the seat back hinge assembly shown in FIG. 9;

[0020] FIG. 11 is a perspective view of the seat back hinge assembly as shown in FIG. 9 attached to a seat back frame assembly;

[0021] FIG. 12 is a partially exploded perspective view of the seat back hinge assembly attached to the seat bottom frame assembly displaced over a seat frame assembly including a jack knife hinge assembly;

[0022] FIG. 13 is a perspective view of an embodiment of the convertible sofa utilizing the seat bottom hinge assembly and utilizing the seat back hinge assembly of the present invention in a sofa or seat configuration;

[0023] FIG. 14 is a perspective view of an embodiment of the convertible sofa utilizing the seat bottom hinge assembly and the seat back hinge assembly of the present invention shown in a lowered seat back configuration;

[0024] FIG. 15 is an exploded perspective view of an alternate embodiment of a seat bottom hinge assembly of the present invention;

[0025] FIG. 16 is a perspective view of the seat bottom hinge assembly of FIG. 15 attached to the seat bottom frame assembly;

[0026] FIG. 17 is a partially exploded perspective view of the seat bottom hinge assembly of FIG. 15 attached to the seat bottom frame assembly over top of a seat frame assembly including a jack knife hinge assembly;

[0027] FIG. 18 is an exploded perspective view of another alternate embodiment of a seat bottom hinge assembly of the present invention;

[0028] FIG. 19 is a perspective view of the seat bottom hinge assembly of FIG. 18 attached to the seat bottom frame assembly;

[0029] FIG. 20 is a partially exploded perspective view of the seat bottom hinge assembly of FIG. 18 attached to the seat bottom frame assembly over top of a seat frame assembly including a jack knife hinge assembly;

[0030] FIG. 21 is a perspective view of an embodiment of the convertible sofa utilizing the seat bottom hinge assembly shown in FIG. 18 of the present invention shown in a sofa or seat configuration;

[0031] FIG. 22 is a perspective view of an embodiment of the convertible sofa utilizing the seat bottom hinge assembly shown in FIG. 18 of the present invention shown in a lifted seat bottom configuration;

[0032] FIG. 23 is a perspective view of an unlocking strap assembly of the present invention used with a convertible sofa utilizing the seat bottom hinge assembly shown in FIG. 18 of the present invention shown in a lifted seat bottom configuration;

[0033] FIG. 24 is a perspective view of the actuator strap loop of the unlocking strap assembly of FIG. 23 extending from a convertible sofa utilizing the seat bottom hinge assembly shown in FIG. 18 of the present invention shown in a lifted seat bottom configuration;

[0034] FIG. 25 is an exploded perspective view of another alternate embodiment of a seat bottom hinge assembly of the present invention;

[0035] FIG. 26 is a perspective view of the seat bottom hinge assembly of FIG. 25 attached to the seat bottom frame assembly; and

[0036] FIG. 27 is a perspective view of an embodiment of the convertible sofa utilizing the seat bottom hinge assembly shown in FIG. 25 of the present invention shown in a lifted seat bottom configuration.

DESCRIPTION OF THE PREFERRED EMBODIMENT

[0037] Referring to FIGS. 1 and 2 of the drawings, a prior art convertible sofa bed 10 utilizing a standard jack knife hinge 25 is shown. The convertible sofa bed 10 comprises generally a seat back cushion 24 attached to a seat back frame 22 and a seat bottom cushion 20 attached to a seat bottom frame 18, both supported by seat frame 12 through a jack knife hinge 25. The prior art jack knife hinge 25 comprises a seat bottom mounting bracket 26 secured to the rear of seat bottom frame 18 by bolts 29 and a seat back mounting bracket 28 secured to the lower end of seat back frame 22 by bolts 31. Mounting brackets 26, 28 are secured to one another by a pivot bolt 27. A first pivot arm 30 is connected at one end to seat bottom mounting bracket 26 by a fastener 16 and, at its other end, to frame 21 by a pivot pin 34. A second pivot arm 36 is connected at one end to seat back mounting bracket 28 by fastener 38 and, at its other end, to frame 21 by pivot pin 40. A cross pivot arm 42 is connected to first pivot arm 30 between its ends by fastener 44 and to second pivot arm 36 between its ends by fastener 46. The jack knife hinge 25 allows the convertible sofa bed 10 to be configured in a sofa or seat configuration as shown in FIG. 1 or in a bed configuration as shown in FIG. 2.

[0038] A first embodiment of the present invention utilizes a seat bottom hinge assembly 41 shown in an exploded and assembled view in FIGS. 3 and 4, respectively. Seat bottom hinge assembly 41 comprises first attachment bracket 43 and a rotatable second inner attachment bracket 45. First attachment bracket 43 comprises a generally vertical portion 47 having a first and a second generally horizontally projecting fastener 48 and 50, respectively. First attachment bracket 43 also comprises a generally horizontal portion 52 having a first and second generally vertically projecting fastener 54 and 56, respectively. Second inner attachment bracket 45 comprises a generally horizontal portion 59 adapted for securing second inner attachment bracket 45 to a bottom seat frame assembly 80. Second inner attachment bracket 45 also comprises a generally vertical portion 57 having a first slot 58 and second slot 60 through which first and second fasteners 48 and 50 extend through when second inner attachment bracket 45 is assembled onto first attachment bracket 43 and secured thereto by nuts 62. First slot 58 is generally horizontal and provides a pivot point about which second inner attachment bracket 45 rotates with respect to first attachment bracket 43. Rotation is controlled by second slot 60, which generally comprises an arcuate portion 64 terminating into a horizontal portion 66. Second inner attachment bracket 45 may also include a spring-loaded lock pin assembly 68, which will prevent second inner attachment bracket 45 from rotating with respect to first attachment bracket 43, as will be discussed in greater detail below.

[0039] Referring now to FIG. 6, seat bottom hinge assembly 41 is shown attached to seat bottom frame assembly 80. This attachment may be accomplished by utilizing fasteners, welding, or any other appropriate fastening means. In FIG. 5, seat bottom frame assembly 80 with attached seat bottom hinge assembly 41 is shown in a partially exploded view over top a seat frame assembly 90 including a jack knife hinge 100. First and second vertically projecting fasteners 54 and 56 extend through apertures 102 in a seat bottom mounting bracket 104 of jack knife hinge 100 and attached thereto by nuts 62. This attachment may be also be accomplished by welding, or any other appropriate fastening means.

[0040] In FIG. 7, a convertible sofa bed 110 is shown including seat bottom hinge assembly 41 of the present invention attached to seat bottom frame assembly 80, including a jack knife hinge 100 configured in a seat configuration. In FIG. 8, the convertible sofa bed 110 is shown with seat bottom frame assembly 80 in a raised configuration providing access to the area below seat frame assembly 90. In order to move seat bottom frame assembly 80 into a raised position, seat bottom frame assembly 80 must be pulled generally horizontally in a direction away from seat back frame assembly 180 such that second fastener 50 of first attachment bracket 43 slides from the horizontal portion 66 of second slot 60 and into the arcuate portion 64 of second slot 60 as best shown in FIG. 6. This enables seat bottom frame assembly 80 to be lifted upwards about the pivot point 57 formed by first fastener 48 of the first attachment bracket 43 and the end of the generally horizontal first slot 58. Attempting to lift seat bottom frame assembly 80 without first pulling outward horizontally away from seat back frame assembly 180 will not result in the seat bottom frame assembly 80 moving upward as the horizontal portion 66 of second slot 60 will prevent this movement. Once the seat bottom frame assembly 80 has been completely rotated upward, spring-loaded lock pin assembly 68 will engage an aperture 88 on first attachment bracket 43, thereby locking seat bottom frame assembly 80 in an upright position. In order to return the convertible sofa bed 110 to the seat position configuration, the spring-loaded lock pin assembly 68 is disengaged, allowing seat bottom frame assembly 80 to rotate downward to its initial generally horizontal position. Returning seat bottom frame assembly 80 to the seat configuration will allow the convertible sofa bed 110 to work as a standard jack knife hinged sofa bed.

[0041] A second embodiment of the present invention utilizes a seat back hinge assembly 141 shown in an exploded and assembled view in FIGS. 9 and 10, respectively. Seat back hinge assembly 141 comprises first attachment bracket 143 and a rotatable second attachment bracket 145. First attachment bracket 143 comprises a first generally planar portion 146 having a first and a second generally perpendicularly projecting fastener 148 and 150, respectively, and an aperture 188. First attachment bracket 143 also comprises a second generally planar portion 152, generally perpendicular to first planar portion 146, including a first and a second projecting fastener 154 and 156, respectively. Second attachment bracket 145 comprises a first planar portion 159 adapted for securing second attachment bracket 145 to a bottom seat frame assembly 180. Second attachment bracket 145 also comprises a second generally planar portion 157 having a slot 158 and an aperture 160 through which first and second fasteners 148 and 150 extend through when second attachment bracket 145 is assembled onto first attachment bracket 143 and secured thereto by nuts 62. Aperture 160 provides a pivot point about which second attachment bracket 145 rotates with respect to first attachment bracket 143. Rotation is controlled by slot 158, which is generally arcuate. Second attachment bracket 145 may also include a spring-loaded lock pin assembly 168, which mates with aperture 188 in the first attachment bracket 143, as best shown in FIG. 9. Spring-loaded lock pin assembly 168 engages aperture 188 to prevent second attachment bracket 145 from rotating with respect to first attachment bracket 143 when the seat back frame assembly 180 is in an upright position in a seat configuration. When the spring-loaded lock pin assembly 168 is disengaged, the seat back frame assembly 180 is free to rotate downward toward the seat bottom frame assembly 80.

[0042] Referring now to FIG. 11, seat back hinge assembly 141 is shown attached to seat back frame assembly 180. This attachment may be accomplished by utilizing fasteners, welding, or any other appropriate fastening means. In FIG. 12, seat back frame assembly 180, with attached seat back hinge assembly 141, is shown in a partially exploded view displaced over a seat frame assembly 190, including a jack knife hinge 100. First and second perpendicularly projecting fasteners 154 and 156 extend through apertures 106 in a seat back mounting bracket 108 of jack knife hinge 100 and attached thereto by nuts 62. This attachment may be also be accomplished by welding, or any other appropriate fastening means.

[0043] In FIG. 13, a convertible sofa bed 210 is shown, including seat back hinge assembly 141 of the present invention, attached to seat back frame assembly 180 including a jack knife hinge 100, configured in a seat configuration. In FIG. 14, the convertible sofa bed 210 is shown with seat back frame assembly 180 in a lowered configuration, providing access to the area behind seat frame assembly 90. In order to move seat back frame assembly 180 into a lowered position, spring-loaded lock pin assembly 168 must be disengaged from aperture 188 such that the seat back frame assembly 180 is free to rotate downward toward the seat bottom frame assembly 80. In order to return the convertible sofa bed 210 to the seat position configuration, seat back frame assembly 180 is rotated upward until the spring-loaded lock pin assembly 168 engages aperture 188, locking the seat back frame assembly 180 into position.

[0044] A third embodiment of the present invention utilizes a seat bottom hinge assembly 241 shown in an exploded view in FIG. 15, shown attached to a seat bottom frame assembly 280 in FIG. 16, and shown attached to a seat assembly 290 in FIG. 17. This embodiment is similar to the first embodiment except that the bottom seat frame assembly 280 is pushed inwards, then lifted, instead of pulled outward, then lifted.

[0045] Seat bottom hinge assembly 241 comprises a first or lower attachment bracket 243 and a rotatable second or upper attachment bracket 245. Lower attachment bracket 243 comprises a first planar portion 247 having a perpendicularly projecting front travel pin 248, a main pivot pin 250, a rear travel slot 270 and a locking aperture 272. Lower attachment bracket 243 also comprises a second planar portion 252 generally perpendicular to first planar portion 247 having a first and second generally vertically projecting fastener 254 and 256, respectively. Upper attachment bracket 245 comprises a first planar portion 259 adapted for securing upper attachment bracket 245 to a bottom seat frame assembly 280. Upper attachment bracket 245 also comprises a second portion 257 generally perpendicular to first planar portion 259 having a first slot 258 and second slot 260 through which front travel pin 248 and main pivot pin 250 extend through when upper attachment bracket 245 is assembled onto lower attachment bracket 243 and secured thereto by nuts 62 (not shown). Second portion 257 of upper attachment bracket 245 also comprises a rear travel pin 274 which mates with rear travel slot 270, and an aperture 260 (not shown) for mounting spring-loaded lock pin assembly 168.

[0046] First slot 258 is generally horizontal and provides a pivot point about which upper attachment bracket 245 rotates with respect to lower attachment bracket 243. Rotation is controlled by front travel slot 260, which generally comprises an arcuate portion 264 terminating into a horizontal portion 266 and rear travel slot 261, which generally comprises an arcuate portion 263 terminating into a horizontal portion 265. Upper attachment bracket 245 may also include a spring-loaded lock pin assembly 168, which will prevent upper attachment bracket 245 from rotating with respect to lower attachment bracket 243, similar to that discussed in relation to the first embodiment.

[0047] Referring now to FIG. 16, seat bottom hinge assembly 241 is shown attached to seat bottom frame assembly 280. This attachment may be accomplished by utilizing fasteners, welding, or any other appropriate fastening means. In FIG. 17, seat bottom frame assembly 280 with attached seat bottom hinge assembly 241 is shown in a partially exploded view over top a seat frame assembly 290 including a jack knife hinge 100. First and second vertically projecting fasteners 254 and 256 extend through apertures 102 in a seat bottom mounting bracket 104 of jack knife hinge 100 and attached thereto by nuts 62. This attachment may be also be accomplished by welding, or any other appropriate fastening means.

[0048] In order to move seat bottom frame assembly 280 into a raised position, seat bottom frame assembly 280 must be pushed generally horizontally in a direction toward seat back frame assembly 180 such that front travel pin 250 of lower attachment bracket 243 slides from the horizontal portion 266 of front travel slot 260 and into the arcuate portion 264. Similarly, rear travel pin 274 of upper attachment bracket 245 slides from the horizontal portion 265 of rear travel slot 270 and into the arcuate portion 264. This enables seat bottom frame assembly 280 to be lifted upwards about the pivot point formed by main pivot pin 248 of the lower attachment bracket 243 and the end of the generally horizontal first slot 258. Attempting to lift seat bottom frame assembly 280 without first pushing inward horizontally toward seat back frame assembly 180 will not result in the seat bottom frame assembly 280 moving upward as the horizontal portion 266 of front travel slot 260 and the horizontal portion 265 of rear travel slot 270 will prevent this movement. Once the seat bottom frame assembly 280 has been completely rotated upward, spring-loaded lock pin assembly 168 will engage aperture 272 on lower attachment bracket 243, thereby locking seat bottom frame assembly 280 in an upright position. In order to return to the seat position configuration, the spring-loaded lock pin assembly 168 is disengaged, allowing seat bottom frame assembly 280 to rotate downward to its initial generally horizontal position.

[0049] A fourth embodiment of the present invention utilizes a seat bottom hinge assembly 341 shown in a disassembled view in FIG. 18. This embodiment is different from the first and third embodiments in that the seat bottom hinge assembly 341 is locked in both the upright and lowered, or seat configurations such that the seat bottom frame assembly 380 does not need to be either pulled or pushed to allow movement, but rather must be unlocked. Seat bottom hinge assembly 341 comprises first attachment bracket 343 and a rotatable second attachment bracket 345. First attachment bracket 343 comprises a first generally planar portion 347 having a pivot point aperture 388 and a seated locking position aperture 348 and an open locked position aperture 350. First attachment bracket 343 also comprises a second generally planar portion 352, generally perpendicular to first planar portion 346, including a first and a second projecting fastener 354 and 356, respectively. Second attachment bracket 345 comprises a first planar portion 359 adapted for securing second attachment bracket 345 to a bottom seat frame assembly 380. Second attachment bracket 345 also comprises a second generally planar portion 357 having a pivot point aperture 358 and a second aperture 360 for mounting spring-loaded lock pin assembly 168 (not shown). First attachment bracket 343 is attached to second attachment bracket 345 by a bolt 375 extending through pivot point apertures 388 and 358, respectively, and secured thereto by nut 62. Apertures 388 and 358 provide a pivot point about which second attachment bracket 345 rotates with respect to first attachment bracket 343. Second attachment bracket 345 includes a spring-loaded lock pin assembly 168, which mates with seated locking position aperture 348 when seat bottom frame assembly 380 is in a lowered, or seat position. Spring-loaded lock pin assembly 168, also mates with open locked position aperture 350 when seat bottom frame assembly 380 is in a raised or open position. Spring-loaded lock pin assembly 168 engages apertures 350, 388 to prevent second attachment bracket 345 from rotating with respect to first attachment bracket 343 when the seat bottom frame assembly 380 is in an upright position or in a seat configuration. When the spring-loaded lock pin assembly 168 is disengaged, the seat bottom frame assembly 380 is free to rotate downward toward the seat frame assembly 390, or upward to a raised position.

[0050] Referring now to FIG. 19, seat bottom hinge assembly 341 is shown attached to seat bottom frame assembly 380. This attachment may be accomplished by utilizing fasteners, welding, or any other appropriate fastening means. In FIG. 20, seat bottom frame assembly 380, with attached seat bottom hinge assembly 341, is shown in a partially exploded view displaced over a seat frame assembly 390, including a jack knife hinge 100. First and second perpendicularly projecting fasteners 354 and 356 extend through apertures 102 in a seat bottom mounting bracket 104 of jack knife hinge 100 and attached thereto by nuts 62. This attachment may be also be accomplished by welding, or any other appropriate fastening means.

[0051] In FIG. 21, a convertible sofa bed 310 is shown, including seat bottom hinge assembly 341 of the present invention, attached to seat bottom frame assembly 380 including a jack knife hinge 100, configured in a seat configuration. In FIG. 22, the convertible sofa bed 310 is shown with seat bottom frame assembly 380 in a raised configuration, providing access to the area below seat frame assembly 390. In order to move seat bottom frame assembly 380 into a raised or lowered position, spring-loaded lock pin assembly 168 must be disengaged from aperture 350, 348 respectively, such that the seat bottom frame assembly 180 is free to rotate downward toward the seat frame assembly 390. Once seat bottom frame assembly 380 is rotated to the selected position, spring-loaded lock pin assembly 168 automatically engages the corresponding aperture 350, 348 of the new position.

[0052] In another embodiment of the present invention, the spring-loaded lock pin assemblies 168 on either side of convertible sofa bed 310 can be disengaged using an unlocking strap assembly 400 as best shown in FIG. 23. Strap assembly 400 comprises a first strap 402 extending between the spring-loaded lock pin assemblies 168 on either side of convertible sofa bed 310. An actuator strap 404 is attached to a midportion of the first strap and extends from the rear to the front of seat bottom frame 380. A loop 406, or tab portion, extends from underneath seat bottom frame 380 as best shown in FIG. 24. Pulling on loop 406 causes tension on first strap 402 and disengages spring-loaded lock pin assemblies 168. This allows the seat bottom frame 380 to rotate either to a raised position or a lowered seat configuration.

[0053] In another embodiment of the present invention, a seat bottom hinge assembly 441 is shown in FIGS. 25-27. Seat bottom hinge assembly 441 is similar to the first embodiment in that the actuation is identical; pull the seat bottom assembly 480 outward and rotate up until it locks. The difference between these embodiments is that the first attachment bracket 443 and second attachment bracket 445 extend downward instead of upward. FIG. 25 shows first attachment bracket 443 attached to seat bottom assembly 480. FIG. 26 shows second attachment bracket 445 being attached to the first attachment bracket 443 on seat bottom assembly 480. FIG. 27 shows the operation of seat bottom hinge assembly 441 in a raised configuration on a convertible sofa bed 410.

[0054] It is contemplated that any of the seat bottom hinge embodiments can be used with the seat top embodiment, or if appropriate, used in place of a seat top embodiment as well.

[0055] Although the present invention has been described above in detail, the same is by way of illustration and example only and is not to be taken as a limitation on the present invention. Accordingly, the scope and content of the present invention are to be defined only by the terms of the appended claims.

Claims

1. A method of making an improved convertible sofa hinge from a standard convertible sofa jack knife hinge, the jack knife hinge connecting a seat back frame and a seat bottom frame to a seat base frame including a side rail, the jack knife hinge having a seat back bracket fixably connected to the seat back frame, a seat bottom bracket fixably connected to the seat bottom frame, the seat back bracket pivotally connected to the seat bottom bracket, a first pivot arm pivotally connected to the side rail and the seat back bracket, a second pivot arm pivotally connected to the side rail and the seat bottom bracket, the cross bar arm pivotally attached to the first pivot arm and the second pivot arm, the method comprising the following steps:

a) removing the seat bottom frame from the seat bottom bracket;

b) fixably attaching a first attachment bracket to the seat bottom frame;

c) pivotally attaching the first attachment bracket to a second attachment bracket; and

d) fixably attaching the seat bottom bracket and the second attachment bracket to the seat base frame.

2. The method of claim 1 further comprising the following steps:

e) removing the seat back frame from the seat back bracket;

f) fixably attaching a third attachment bracket to the seat back frame;

g) pivotally attaching the third attachment bracket to a fourth attachment bracket; and

h) fixably attaching the fourth attachment bracket to the seat back bracket.

3. The method of claim 1 further comprising the following steps:

e) attaching a locking pin to the first attachment bracket;

f) providing an aperture in the second attachment bracket such that the locking pin engages the aperture when the seat bottom frame is in a seat configuration.

4. The method of claim 1 further comprising the following steps:

e) attaching a locking pin to the first attachment bracket;

f) providing an aperture in the second attachment bracket such that the locking pin engages the aperture when the seat bottom frame is raised to a storage access configuration.

5. A method of making an improved convertible sofa hinge from a standard convertible sofa jack knife hinge, the jack knife hinge connecting a seat back frame and a seat bottom frame to a seat base frame including a side rail, the jack knife hinge having a seat back bracket fixably connected to the seat back frame, a seat bottom bracket fixably connected to the seat bottom frame, the seat back bracket pivotally connected to the seat bottom bracket, a first pivot arm pivotally connected to the side rail and the seat back bracket, a second pivot arm pivotally connected to the side rail and the seat bottom bracket, the cross bar arm pivotally attached to the first pivot arm and the second pivot arm, the method comprising the following steps:

a) removing the seat back frame from the seat back bracket;

b) fixably attaching a first attachment bracket to the seat back frame;

c) pivotally attaching the first attachment bracket to a second attachment bracket; and

d) fixably attaching the second attachment bracket to the seat back bracket.

6. The method of claim 1 further comprising the following steps:

e) attaching a locking pin to the first attachment bracket;

f) providing an aperture in the second attachment bracket such that the locking pin engages the aperture when the seat back frame is in a seat configuration.

7. The method of claim 1 further comprising the following steps:

e) attaching a locking pin to the first attachment bracket;

f) providing an aperture in the second attachment bracket such that the locking pin engages the aperture when the seat back frame is lowered to an access configuration.

8. A hinge assembly for a convertible sofa, the hinge connecting a seat back frame and a seat bottom frame to a seat base frame including a side rail, the hinge for a convertible sofa comprising:

a seat back bracket fixably connected to the seat back frame,

a seat bottom bracket pivotally connected to the seat back bracket,

a first pivot arm pivotally connected to the side rail and the seat back bracket,

a second pivot arm pivotally connected to the side rail and the seat bottom bracket,

a cross bar arm pivotally attached to the first pivot arm and the second pivot arm,

a first attachment bracket fixably attached to the seat bottom frame,

a second attachment bracket pivotally attached the first attachment bracket, and

wherein the seat bottom bracket and the second attachment bracket are fixably attached to the seat base frame.

9. The hinge assembly of claim 8 further comprising:

a third attachment bracket fixably attached to the seat back frame,

a fourth attachment bracket pivotally attached the third attachment bracket, and

wherein the fourth attachment bracket is fixably attached to the seat back bracket.

10. The hinge assembly of claim 8 further comprising:

a locking pin attached to the first attachment bracket;

an aperture formed in the second attachment bracket;

wherein the locking pin engages the aperture in the second attachment bracket when the seat bottom frame is in a seat configuration, preventing movement of the seat bottom frame.

11. The hinge assembly of claim 8 further comprising:

a locking pin attached to the first attachment bracket;

an aperture formed in the second attachment bracket;

wherein the locking pin engages the aperture in the second attachment bracket when the seat bottom frame is raised to a storage access configuration.

12. The hinge assembly of claim 8 further comprising:

a slot formed in the first attachment bracket;

a pin projecting from the second attachment bracket through the slot formed in the first attachment bracket;

wherein the slot controls the movement of the first attachment bracket with respect to the second attachment bracket.

13. The hinge assembly of claim 12, wherein the slot has at least one portion formed as an arc.

14. The hinge assembly of claim 12, wherein the slot has at least one portion formed as a straight section.

15. A hinge assembly for a convertible sofa, the hinge connecting a seat back frame and a seat bottom frame to a seat base frame including a side rail, the hinge for a convertible sofa comprising:

a seat back bracket fixably connected to the seat back frame,

a seat bottom bracket pivotally connected to the seat back bracket,

a first pivot arm pivotally connected to the side rail and the seat back bracket,

a second pivot arm pivotally connected to the side rail and the seat bottom bracket,

a cross bar arm pivotally attached to the first pivot arm and the second pivot arm,

a first attachment bracket fixably attached to the seat back frame,

a second attachment bracket pivotally attached the first attachment bracket, and

wherein the second attachment bracket is fixably attached to the seat back bracket.

16. The hinge assembly of claim 15 further comprising:

a locking pin attached to the first attachment bracket;

an aperture formed in the second attachment bracket;

wherein the locking pin engages the aperture in the second attachment bracket when the seat back frame is in a seat configuration, preventing movement of the seat back frame.

17. The hinge assembly of claim 15 further comprising:

a locking pin attached to the first attachment bracket;

an aperture formed in the second attachment bracket;

wherein the locking pin engages the aperture in the second attachment bracket when the seat back frame is rotated downward from a seat configuration.

18. The hinge assembly of claim 8 further comprising:

a slot formed in the first attachment bracket;

a pin projecting from the second attachment bracket through the slot formed in the first attachment bracket;

wherein the slot controls the movement of the first attachment bracket with respect to the second attachment bracket.

19. The hinge assembly of claim 12, wherein the slot has at least one portion formed as an arc.

20. A convertible sofa comprising:

a seat back frame;

a seat bottom frame;

a seat base frame including a side rail on opposite sides of the seat base frame wherein the seat base frame encloses a storage area;

a pair of hinges connecting the seat back frame and the seat bottom frame to the seat base frame, wherein each hinge comprises a seat back bracket fixably connected to the seat back frame, a seat bottom bracket pivotally connected to the seat back bracket, a first pivot arm pivotally connected to the side rail and the seat back bracket, a second pivot arm pivotally connected to the side rail and the seat bottom bracket, a cross bar arm pivotally attached to the first pivot arm and the second pivot arm, a first attachment bracket fixably attached to the seat bottom frame, a second attachment bracket pivotally attached the first attachment bracket;

wherein the seat bottom bracket and the second attachment bracket are fixably attached to the seat base.

21. The convertible sofa of claim 20 further comprising:

a third attachment bracket fixably attached to the seat back frame,

a fourth attachment bracket pivotally attached the third attachment bracket, and

wherein the fourth attachment bracket is fixably attached to the seat back bracket.

22. The convertible sofa of claim 20 further comprising:

a locking pin attached to the first attachment bracket;

an aperture formed in the second attachment bracket;

wherein the locking pin engages the aperture in the second attachment bracket when the seat bottom frame is in a seat configuration, preventing movement of the seat bottom frame.

23. The convertible sofa of claim 20 further comprising:

a locking pin attached to the first attachment bracket;

an aperture formed in the second attachment bracket;

wherein the locking pin engages the aperture in the second attachment bracket when the seat bottom frame is raised to a storage access configuration.

24. The convertible sofa of claim 20 further comprising:

a slot formed in the first attachment bracket;

a pin projecting from the second attachment bracket through the slot formed in the first attachment bracket;

wherein the slot controls the movement of the first attachment bracket with respect to the second attachment bracket.

25. The convertible sofa of claim 24, wherein the slot has at least one portion formed as an arc.

26. A convertible sofa comprising:

a seat back frame;

a seat bottom frame;

a seat base frame including a side rail on opposite sides of the seat base frame wherein the seat base frame encloses a storage area;

a pair of hinges connecting the seat back frame and the seat bottom frame to the seat base frame, wherein each hinge comprises a seat back bracket fixably connected to the seat back frame, a seat bottom bracket pivotally connected to the seat back bracket, a first pivot arm pivotally connected to the side rail and the seat back bracket, a second pivot arm pivotally connected to the side rail and the seat bottom bracket, a cross bar arm pivotally attached to the first pivot arm and the second pivot arm, a first attachment bracket fixably attached to the seat back frame, a second attachment bracket pivotally attached the first attachment bracket, and

wherein the second attachment bracket is fixably attached to the seat back bracket.