Title:
Convertible sofa-bed and method therefore
Kind Code:
A1


Abstract:
The present invention is a simple convertible futon sofa-bed. In particular the convertible futon sofa-bed is comprised of a pair of armrest sub-assemblies, a front stretcher rail and a back stretcher rail connecting the pair of armrest assemblies, a seat-deck, a back-deck and a ratchet connecting means to convert the convertible futon sofa-bed from a sofa position to a bed position.



Inventors:
Tan, Tony Harsono (Medan, ID)
Application Number:
11/438521
Publication Date:
11/29/2007
Filing Date:
05/23/2006
Primary Class:
International Classes:
A47C17/16
View Patent Images:
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Primary Examiner:
TRETTEL, MICHAEL
Attorney, Agent or Firm:
Tony Harsono Tan (Medan, ID)
Claims:
I claim:

1. An improved convertible futon sofa-bed assembly comprising: a pair of armrest sub-assemblies; a front stretcher rail; a back stretcher rail, said back stretcher rail and said front stretcher rail connecting said pair of armrest sub-assemblies; a seat-deck; a back-deck, and; a pair of ratchet connecting means attached to said back-deck and said seat-deck, said back-deck and said seat-deck dimensioned so that the width of said back-deck and the width of said seat-deck are substantially identical, said ratchet connecting means operationally configured such that when said convertible sofa-bed is in the sofa position, said seat-deck is urgeable towards the front of said back-deck until said back-deck rests on said back stretcher rail whereupon said back-deck is lockable onto a pair of grooves on said armrest sub-assemblies, said seat-deck then being further urgeable forward to unlock said ratchet connecting means whereafter said seat-deck is further urgeable downwards until said seat-deck rests on the front stretcher rail in a bed position wherein said seat-deck and said back-deck are in an essentially uniplanar position.

2. The improved convertible futon sofa-bed assembly of claim 1 wherein the edges of the side rails of the back-deck and the seat deck are secured to the ratchet connecting means by a plurality of nuts and bolts such that the arms of said ratchet connecting means is mounted to at least three inches (0.0762 meter) of said side rails such that the force created during conversion is spread across a significant area of said side rails.

3. The improved convertible futon sofa-bed as claimed in claim 1, wherein the angle of inclination of the back-deck (65) to the seat-deck (40) is determined by position of the pawl on the ratchet teeth.

4. The improved convertible futon sofa-bed as in claim 1 wherein the arms of the ratchet connecting means are introduced into slits at the terminal ends of the side rails of the back-deck and seat-deck and secured by a plurality of nuts and bolts.

5. The improved convertible futon sofa-bed as claimed in claim 1 wherein the edge of the side rails of the back-deck and the seat-deck are recessed and contoured to accommodate the arms of the ratchet connecting means.

6. The improved convertible futon sofa-bed as claimed in claim 1 wherein the seat-deck is urgeable toward the back-deck by applying a force at any point along front rail of the seat-deck.

7. The improved convertible futon sofa-bed as claimed in claim 1 wherein the ratchet connecting means is independent and spatially separated from the pair of armrest sub-assemblies.

8. The improved convertible futon sofa-bed as claimed in claim 1 wherein the pair of armrest sub-assemblies, the front stretcher rail, the back stretcher rail, seat-deck and back-deck are of wood, wood based material or wood composite.

9. A method of converting an improved convertible futon sofa-bed consisting of a pair of armrest sub-assemblies, a front stretcher rail, a back stretcher rail, a seat-deck, a back-deck and a ratchet connecting means pivotally connecting said seat-deck and said back-deck from a sofa position to a bed position comprising the steps of: lifting said seat-deck towards said back-deck until said back-deck rests upon said back stretcher rail; urging said seat-deck further to unlock and to release said ratchet connecting means, and; further urging said seat-deck back to said front stretcher rail whereupon said back-deck and said seat-deck are in a essentially uniplanar position.

10. A method of converting an improved convertible sofa-bed consisting of a pair of armrest sub-assemblies, a front stretcher rail, a back stretcher rail, a seat-deck, a back-deck and a ratchet connecting means pivotally connecting said seat-deck and said back-deck from a bed position to a lounge position comprising the steps of: lifting said seat-deck upward to reach the position in said ratchet connecting means where a locking sound is heard confirming registration of position, and; urging said seat-deck back to said front stretcher rail whereupon said back-deck and said seat-deck are in a lounge position.

11. A method of converting an improved convertible sofa-bed consisting of a pair of armrest sub-assemblies, a front stretcher rail, a back stretcher rail, a seat-deck, a back-deck and a ratchet connecting means pivotally connecting said seat-deck and said back-deck from a lounge position to a sofa position comprising the steps of: lifting said seat-deck towards said back-deck until said back-deck rests upon said back stretcher rail; urging said seat-deck further to unlock and to release said ratchet connecting means; further lifting said seat-deck toward said back-deck until said back-deck rests upon said back stretcher rail; further urging said seat-deck to reach the next desired position in said ratchet connecting means where a locking sound is heard confirming registration of position, and; still further urging said seat-deck back to said front stretcher rail whereupon said back-deck and said seat-deck are in a sofa position.

Description:

BRIEF DESCRIPTION

The present invention relates to convertible furniture. More particularly, the invention relates to an improvement of a convertible futon sofa-bed which enables a quick, easy and secure conversion from bed to a lounge to sofa position and from sofa to bed to lounge position.

BACKGROUND OF INVENTION

The convertible sofa-bed industry has grown from a relatively small business to a much larger business. Further convertible futon sofa-beds now come with a greater variety of styles, functions and appeals. Along with growth in this industry, many similar convertible furniture products have increasingly enhanced the reliability and attractiveness with a reasonable price. Moreover, many conventional convertible futon sofa-beds provide better quality finishes and are more user friendly.

Nevertheless conventional futon sofa-beds suffer operational and structural setbacks and disadvantages. The applicant believes substantial improvements to the sofa-bed can be made to correct a number of these disadvantages. The improvements include, among others:

i) improvements in sofa-bed structural configuration;

ii) improvement in the method of conversion; and

iii) reduction of manufacturing costs.

A convertible futon sofa-bed (hereinafter referred as futon sofa-bed or futon frame) is convertible from a bed position to a seating position and back again. Accordingly, the futon sofa-bed requires a series of specific movements and mechanical parts to achieve the conversions. In one prior art apparatus described in U.S. Pat. No. 6,357,062 B1, the futon sofa-bed has a seat-deck and back-deck pivotably joined to one another. The sofa-bed can be substantially flat (bed position) or angled (seating position). The joined seat-deck and back-deck of the futon sofa-bed slide in rollers in appropriately positioned slots in side arms and legs of the armrest assembly. Each flat or angled configuration of the decks is held stable for use by rollers that become lodged in the ends of respective guide slots.

The futon frame of this prior art apparatus is workable and suitable for its intended purpose. However, it still requires significant physical effort by a person to convert it from the bed position to the seating position or vice versa. As example, during conversion of the sofa-bed, care is needed when pulling the seat-deck forward (from the back-deck) so that the back-deck does not fall down quickly and slam hard into its bed position by its own weight. When converting back from the bed to seating position, the user is required to stand at the front of the seat-deck to pull the seat-deck out of its locked position and then move to the back of frame to lift the back-deck up into the seating position. In addition, during the assembly of the sofa-bed, the pivot joint must fit through a hole in the seat-deck frame and align correctly with a hole in the back-deck frame. The fitting of these pivot joins is awkward and alignment of these holes can be difficult.

In the later development of the conventional futon sofa-bed, improvements in converting mechanisms have been made. These mechanisms are commonly known as front converting systems. This solution uses a system of two points on the seat-deck or back-deck forming a lock onto a platform so as to lock and lever up or down the back-deck into the desired position by moving the seat-deck thereby operating only from the front. Although these systems allow users to convert from the front with more ease and control, they still present a number of flaws. These flaws include breakage due to metal pins extending from the seat-deck into wood slots, which are used both as the pivot and locking points to a futon frame. These metal pins often cause breakage of the frame components due to the great stress on the contact point between the metal pins and the wood slots. Since the length of the wood slots runs parallel to the wood grain, the stress often splits the wood. Moreover, the metal pins can leave indentations in the wooden chamber of the slot when it is used under stress. These indentations make smooth movement of the metal pins in the slots increasingly difficult over time. Additional stoppers are required to attach at the bottom part of the seat-deck in the side rail to prevent the seat-deck from sliding forward under the tension of futon mattress.

Yet another flaw is that when converting the futon sofa-bed from the seating position to the bed position, there exists the possibility that the user pulls the seat-deck too hard or too gently forward. This causes the lock points of a futon frame to unlock and causes the back-deck to fall down hardly. In addition, any uneven forward pulling of the seat-deck sometimes causes the frame to jam because one side of the lock points is released and other remains locked. This also causes damage or breakage of the futon frame during the conversion. The metal pins are in a fixed position on the back-deck and in the slots in the seat-deck for sliding over. The nature of this design requires the seat-deck to move deeper into, or in towards and under the back-deck when pushed into the seating position; in other words, the parts of the seat-deck and back-deck are telescopically engaged. The sliding of the seat-deck towards and under the back-deck results in the shortening of the seat-deck in the seating position by several centimeters. Alternatively, the lengthening of the seat-deck to compensate for the shorter portion makes the platform too wide in the bed position.

Additionally, the futon mattresses used on the frame have become increasingly heavier. The increasing weight of the futon mattress amplifies the problems mentioned above. Moreover, the conventional futon sofa-bed requires the seat-deck to bend toward the back-deck so as to unlock the metal pins from the lock point between the seat-deck and beck-deck to allow free movement. The conversion of the futon sofa-bed is awkward when the conversion is done by a user with low physical strength.

There is also a tendency of the futon mattress to spring away from the sofa-bed frame when the seat-deck is bent toward the back-deck. One prior art apparatus described in U.S. Pat. No. 5,083,333 has been used to overcome these problems by using a metal plate. The prior art apparatus metal plate is stamped with slots and notches to take the force exerted by the metals pins and thereby relieve the stress on the wooden components. Although the use of a metal plate can reduce breakage, the metal against metal causes an uncomfortable sound during the conversion. Operating the prior art sofa-bed includes a series of short, separate movements of the sofa-bed frame instead of a preferred smooth continuous movement.

SUMMARY OF THE INVENTION

The present invention is a simple convertible futon sofa-bed. In particular the convertible futon sofa-bed is comprised of a pair of armrest sub-assemblies, a front stretcher rail and a back stretcher rail connecting the pair of armrest assemblies, a seat-deck, a back-deck and a ratchet connecting means to convert the convertible futon sofa-bed from a sofa position to a bed position.

A unique characteristic of the convertible sofa-bed of the present invention is that the width of the back-deck and the seat-deck are substantially identical in length. The edge of the side rails of the back-deck and the seat deck are secured to the ratchet connecting means such that the arms of the ratchet connecting means is mounted over at least a three inch span of the side rails so that the force created during conversion is spread across the side rails. A plurality of bolts and nuts is used to secure the ratchet connecting means to the back-deck and seat-deck. When the convertible sofa-bed is in the first sofa position, the seat-deck is urgeable towards the front of the back-deck until the back-deck rests on the back stretcher rail whereupon the back-deck is lockable onto a pair of grooves on the armrest sub-assemblies. The seat-deck is further urgeable forward to unlock the ratchet connecting means. Thereafter the seat-deck is urgeable downwards until it rests on the front stretcher rail in its second bed position such that the seat-deck and the back-deck are in a uniplanar position.

The convertible sofa-bed of the present invention also enables conversion from the bed position (wherein the seat-deck and the back-deck are in a single planar position) to the lounge position (wherein the seat-deck is in planar position wherein the back-deck is inclined at an obtuse angle in relation to the seat-deck) by two simple steps. The conversion begins with lifting the seat-deck upwards to reach the desired lock of the ratchet connecting means at the correct lounge position angle. In the locking position, the back-deck is capable of being oriented in relation to the seat-deck when the seat-deck is pushed downwards. The seat-deck is then urged back until it rests on the front stretcher rail whereupon the conversion of the convertible sofa-bed from bed position to lounge position is completed.

In addition, the convertible sofa-bed of the present invention is also further convertible from the lounge position to the sofa position (wherein the seat-deck is in a planar position and the back-deck is inclined substantially vertical in relation to the seat-deck) by two simple steps. Similar to the above conversion, the seat-deck is lifted towards the back-deck until the back-deck rests on the back stretcher rail. The seat-deck is further urged forward to reach the next desired position in the lock of the ratchet connecting means to form the proper angle of the sofa position. In the locked sofa position, the back-deck is capable of being oriented in relation to the seat-deck when seat-deck is pushed downwards. The seat-deck is then urged back to the front stretcher rail whereupon the back-deck and the seat-deck are converted to the sofa position.

The pair of armrest sub-assemblies, the front stretcher rail, the back stretcher rail, seat-deck and back-deck are of wood, wood based material or wood composite. The angle of inclination between the back-deck and the seat-deck of the convertible futon sofa-bed is determined by position of the pawl on the ratchet teeth. The arms of the ratchet connecting means is introduced into slits at the terminal ends of the side rails of the back-deck and seat-deck and secured by nuts and bolts. The edge of the side rails of back-deck and the seat-deck are recessed and contoured to accommodate the arms of the ratchet connecting means. The ratchet connecting means is independent and spatially separated from the pair of armrest sub-assemblies. The seat-deck is urgeable toward the back-deck by applying force at any point along front rail of the seat-deck.

The method of converting the convertible futon sofa-bed of the present invention consisting of a pair of armrest sub-assemblies, a front stretcher rail, a back stretcher rail, a seat-deck, a back-deck and a ratchet connecting means pivotally connecting the seat-deck and back-deck from a first sofa position to a second bed position comprises the steps of lifting the seat-deck towards the back-deck until the back-deck rests upon the back stretcher rail, urging the seat-deck further to unlock and to release the ratchet connecting means, and then urging the seat-deck back to the front stretcher rail whereupon the back-deck and the seat-deck are in a uniplanar position to form a bed.

Similarly, the method of converting the convertible sofa-bed of the present invention from a bed position to a lounge position comprises the steps of lifting the seat-deck upward to reach the desired position in the ratchet connecting means until a locking sound is heard to confirm registration of position and then urging the seat-deck back to the front stretcher rail whereupon the back-deck and the seat-deck are locked in a lounge position.

The method of converting the convertible sofa-bed of the present invention from a lounge position to a sofa position comprises the steps of first repeating the first two steps as described above in converting the convertible sofa-bed from a bed position to a lounge position, then lifting the seat-deck towards the back-deck until the back-deck rests upon the back stretcher rail, urging the seat-deck further to reach the next desired position in the ratchet connecting means until a sound is heard to confirm registration of position, and urging the seat-deck back to the front stretcher rail whereupon the back-deck and the seat-deck are in a sofa position.

One advantage of the present invention is the ability to lock the seat deck and back deck into more than just the simple sofa or bed positions of the conventional art. This and other features and advantages of the present invention are discussed in detail below in conjunction with the drawings and figures.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1: shows a perspective view of the convertible sofa-bed frame of the present invention in a sofa position.

FIG. 2A: shows a side view of the convertible sofa-bed frame of the present invention in the sofa position.

FIG. 2B: shows an enlarged portion of one terminal end of a side rail that may be used in the frame of the convertible sofa-bed of the present invention.

FIGS. 3A-3E: show the steps of the convertible futon sofa-bed of the present invention converting from a sofa position to a bed position.

FIGS. 4A-4C: show the steps of the convertible futon sofa-bed of the present invention converting from a bed position to a lounge position.

FIGS. 5A-5C: show the steps of the convertible futon sofa-bed of the present invention converting from a lounge position to a sofa position.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to the figures, the preferred embodiment of the present invention is shown. FIG. 1 shows the convertible futon sofa-bed frame (5) of the present invention in a sofa position. The convertible futon sofa-bed frame (5) is preferably made of wood, wood based material or wooden composites. Said convertible futon sofa-bed frame (5) includes a pair of spaced apart stationary armrest sub-assemblies (10) and a pair of spaced apart and parallel stretcher rails, front stretcher rail (15) and back stretcher rail (20) extending along a width-wise direction between the armrest sub-assemblies (10). Each armrest sub-assembly (10) includes a pair of legs (25) and (30) which extends from an armrest (35) to the floor. The legs (25) and (30) of each armrest sub-assembly (10) are spaced apart along the width-wise direction. The front stretcher rail (15) and back stretcher rail (20) are associated with each armrest sub-assembly (10) and they extend between the legs (25) and (30). The stretchers are parallel to the width-wise direction of the sofa-bed.

A seat-deck (40) includes a pair of side rails (45), a front rail (50) and a back rail (55) which are coupled at the ends forming a substantially rectangular shape. The side rails (45) are spaced apart and extend parallel to each other and with the front rail (50) and back rail (55) extending transverse thereto. A plurality of slats (60) extends between the front rail (50) and back rail (55) and are spaced apart arrange along the width-wise direction of the front rail (50).

A back-deck (65) is identical to the seat-deck (40) and includes a pair of side rails (70), a front rail (75) and a back rail (80) each coupled at the ends forming a substantially identical rectangular shape with seat-deck (40). Similarly, the side rails (70) of back-deck are spaced apart and extend parallel to each other and with the front rail (75) and back rail (80) extending transverse thereto. A plurality of slats (60) extend between the front rail (75) and back rail (80) and spaced apart arrange along the width-wise direction of the front rail (75). It is to be noted that the width of the back-deck (65) and the seat-deck (40) are substantially identical in dimension. The seat-deck (40) and back-deck (65) are hingeably attached by a pair of ratchet mechanisms (85) as discussed in greater detail below.

Referring to FIG. 2A, a side view of the convertible sofa-bed frame (5) of the present invention in sofa position is shown. The side rail (70) of the back-deck (65) includes runners (70a) and (70b) which is set in between armrest sub-assembly (10) at grooves (10a) and (10b) respectively. The edge of the side rails (70, 45) of the back-deck (65) and the seat-deck (40) are recessed and contoured to accommodate the arms (85a) of ratchet connecting means (85). The ratchet connecting means can be of any ratchet device in the market provided it can be securably mounted to the edge of the side rails to ensure rigid connection between the back-deck (65) and seat-deck (40).

Referring to FIG. 2B, there is shown an enlarged portion of one terminal end of a side rail. Note that this could be any side rail, but for purposes of this detailed discussion, this is side rail (45) of the seat-deck (40). The structure of wood, including annual rings (46) and rays (47), produces the characteristic of grain patterns in different species of trees. The grain pattern is also determined by the plane in which the logs are cut at the saw mill. FIG. 2B illustrates the wood having annual rings (46) and rays (47) along section planes A, B, and C. Section plane A is known as transverse plane or cross-section of the annual rings (46) appears like concentric bands, with rays (47) extending outward like the spokes of a wheel. Section Plane B is known as tangential plane. The tangential plane are made perpendicular to the rays (47) and tangential to the annual rings (46) and face of the log. The annual rings appear in irregular, wavy patterns. Section plane C is known as the radial plane. Radial planes are made along the rays (47) or radius of the log, at right angles to the annual rings (46). This plane is more wear-resistant because dense, dark summer bands (annual rings) are closely spaced. The arm (85a) of the ratchet connecting means (85) is preferably mounted on the section plane B to avoid split of the wood due to the nature of wood grain patterns.

The edge of the side rails (70, 45) of the back-deck (65) and the seat deck (40) are secured to the ratchet connecting means (85) such that the arms of the ratchet connecting means (85) is mounted over at least a three inch span of the side rails (70, 45). By this means, the force created during conversion is spread across the side rails (70, 45). Alternatively, the edge of the side rails (70, 45) of back-deck (65) and the seat-deck (40) are recessed and contoured to accommodate the arms (85a) of the ratchet connecting means (85). Bolts and nuts are use to secure the arms of the ratchet connecting means (85) preferably fastened though section plane B to provide a stronger structure as well as avoid wood splitting.

The seat-deck (40) and the back-deck (65) are secured to rotatably move as a single unit related to one another when the ratchet connecting means (85) is in the lock position. Therefore, when the seat-deck (40) is lifted toward the back-deck (65), the runner (70a) disposed at the side rail (70) of the back-deck (65) slidably moves along the groove (10a) at the armrest sub-assembly (10). Meanwhile, the back-deck (65) is lowered until the runner (70b) comes to sit and locked into a slot of the groove (10b) and thereby rests on the back stretcher rail (20 of FIG. 1).

In a conventional convertible sofa-bed, the conversion of the convertible sofa-bed from the sofa position to the bed position and back again is made difficult by the weight of the heavy mattress. Moreover, the weight of the sofa-bed frame members and its conversion mechanism require substantial physical effort by a person to convert it from the bed position to the sofa position or vice versa. The conversion of the sofa-bed also requires the user to move around the frame, front and back, lifting or pulling, as the user converts the frame through the various converting steps. To provide ease and convenience to the user, it is preferred that the user stand only at the front of the convertible sofa-bed when converting between any and all positions. To further provide ease and convenience to the user the use of the ratchet mechanism to assist the user with the conversion is also preferred that, providing the user with more control and giving more balance to the frame parts by locking the seat-deck (40) and back-deck (65) in a balanced locked position relative to each other.

In use, the methods of converting the convertible sofa-bed (5) of the present invention from a first sofa position to a second bed position is shown in FIGS. 3A, 3B, 3C, 3D and 3E. The present invention allows the user to convert the convertible sofa-bed (5 of FIG. 1) standing only at the front, while advantageously providing more control and ease than the conventional sofa-bed.

Referring to FIGS. 3A and 3B, the method of converting the convertible sofa-bed of the present invention starts with lifting the seat-deck (40) (wherein the seat-deck initially rests on the front stretcher rail (15) of FIG. 3A)) towards the back-deck (65) until the back-deck (65) rests upon the back stretcher rail (20) of FIG. 3B. In the locked sofa position, the back-deck (65) is capable of being oriented in relation to the seat-deck (40) when the seat-deck (40) is lifted up.

Looking now at FIGS. 3C and 3D, the seat-deck is then further urged forward to unlock and to release the ratchet connecting means (85) whereupon the seat-deck (40) can be freely pulled back and pushed downward until it rests on the front stretcher rail (15) of the convertible sofa-bed (5) as shown in FIG. 3D. FIG. 3E shows the complete conversion of the convertible sofa-bed (5) of the present invention from the sofa position to the bed position wherein the back-deck (65) and seat-deck (40) are in uniplanar orientation with each deck is resting on the back stretcher rail (20) and front stretcher rail (15) respectively to form the bed.

Referring to FIGS. 4A, 4B and 4C, the method of converting the convertible sofa-bed (5) of the present invention from the bed position to the lounge position is shown. The conversion starts with lifting the seat-deck (40) upwards to reach the desired lock of the ratchet connecting means (85) (FIG. 4A and 4B). The seat-deck (40) is then urged back so that it is rests on the front stretcher rail (15) whereupon the back-deck (65) and the seat-deck (40) are now in the lounge position. Again, in the locked lounge position, the back-deck (65) is capable of being oriented in relation to the seat-deck (40) when the seat-deck (40) is pushed downward. The movement from pushing the seat-deck (40) downwards until its rests on the front stretcher rail (15) is shown in FIG. 4B and 4C. The complete conversion from bed position to lounge position of the convertible sofa-bed is shown in FIG. 4C.

Referring to FIGS. 5A, 5B and 5C the conversion of the convertible sofa-bed (5) of the present invention from the lounge position to the sofa position is shown. Similar to the above conversion just discussed, the seat-deck (40) starts with lifting toward the back-deck (65) until the back-deck (65) rests on the back stretcher rail (20) (FIG. 5A). Referring to FIG. 5B, the seat-deck (40) is further urged forward to reach the next desired position in the lock of the ratchet connecting means (85) to form an angle of the sofa position. In the locked sofa position, the back-deck (65) is capable of being oriented in relation to the seat-deck (40) when the seat-deck (40) is pushed downward. The seat-deck (40) is then urged back to the front stretcher rail (15) whereupon the back-deck (65) and the seat-deck (40) are in complete conversion in sofa position.

A first advantage of the present invention is that it provides easier conversion of the futon sofa-bed from one position to another. In particular it eliminates the unnecessary steps found in the conversion of prior art futon sofa-bed, such as the series of short paced apart movement. Now desirable smooth continuous movements are adopted. This not only reduces the time taken to convert the futon sofa-bed from one position to another, but is also very user friendly. Moreover, the seat-deck (40) and back-deck (65) being of identical length enables standardization of parts, thus reducing manufacturing costs.

A second advantage of the convertible futon sofa-bed of the present invention is that it provides a user with three possible positions. Not only does the present invention allow conversion from a sofa position to a bed position, but also allows the conversion from a sofa position to a lounge position, and then from a lounge position to a bed position, and back to lounge and sofa positions with simple movement steps.

A third advantage of the present invention is that the conventional metal pins have been replaced by runners. The runners substantially reduce the stress forces acting on the groove slots which provides for smoother movement. Further, the runners help prevent the groove slots from being damaged due to wear and tear caused by the sliding movement during the conversion. As the seat-deck and the back-deck are connected by means of the ratchet connecting means to form a sub-assembly, a more rigid sofa-bed frame assembly is obtained.

A fourth advantage of the present invention is that the force required to do the conversion between positions is reduced and is more uniform than in prior art apparatuses. A user can exert a lifting force anywhere along the front of the sofa bed to accomplish the conversion steps. This is enabled by the ratchet connecting means instead of the convention pins. Conventional pins tend to jam due to off-center application of any lifting force. The ratchet connecting means, because it provides a stiffer frame mounting member, allows off center forces to be used thereby easing the user conversion process.