EP2805645A1

EP2805645A1 - Sofa

Info

Publication number: EP2805645A1
Application number: EP13179549.4A
Authority: EP
Inventors: Tadanobu Yamashita
Original assignee: Koyo Giken KK
Current assignee: Koyo Giken KK
Priority date: 2013-05-20
Filing date: 2013-08-07
Publication date: 2014-11-26
Also published as: JP5498608B1; CN203662361U; CN104172787A; JP2014226207A

Abstract

A sofa provided with an armrest portion (49), connected to a sofa fixation portion (45) with an angle-adjustable hinge (3) and freely angle-adjusted, and switched between a locked state in which the armrest portion (49) is oscillatable to a standing direction (A) and oscillation in an inclining direction (B) of the armrest portion (49) is restricted, and a free state in which the oscillation in the inclining direction (B) is made possible by nullifying the restriction with a standing lock-releasing posture (To) of the armrest portion (49). The posture of the armrest portion (49) in a random middle inclination posture (T₁) in the free state, on way of oscillation in the inclining direction (B) from the lock-releasing posture (To) to a lowest laid posture (T₂) for recovering the lock, is kept by recovering the locked state with a return action (M₂) of a predetermined small angle (θ) in the standing direction (A).

Description

This invention relates to a sofa.
Conventionally, a sofa to which an armrest portion is attached to be reclined (freely angle-adjustable) is disclosed (refer to Japanese utility model publication No. H3-30054 ).
The conventional sofa is constructed as that lock is released when the armrest portion is raised to a vertical posture (lock-releasing position) to make an oscillation in inclining direction possible, then, the lock is recovered when the armrest portion is oscillated (inclined) to a horizontal posture (lock recovery position). With the recovery of the locked state, the inclined posture can be held with a desired inclination angle when the armrest portion is gradually oscillated to the raising direction.
However, when the lock is once released, the lock can't be recovered until the armrest portion is made to have the horizontal posture (lock recovery position). That is to say, there is a disadvantage that angle adjustment of the armrest portion can't be started on a middle inclined position between the lock-releasing position and the lock recovery position.
For example, when excessive load is on the armrest portion under the locked state, a frame of the armrest portion is bent (in the inclining direction), or an arm of an angle-adjustable hinge is plastically deformed, the lock may not be recovered without further inclination beyond the horizontal posture. In case that the sofa is placed on the floor, the armrest can' t be inclined lower than the horizontal posture, the entire sofa needs to be raised up when the angle adjustment of the armrest portion is conducted, and this causes much labor. And, when the sofa is placed along a wall, the armrest portion may interfere (contact) with the wall and may not oscillate to the lock recovery position, and, the lock may not be recovered in case that the armrest portion interferes with obstacles such as a wall before reaching for the lock recovery position.
Therefore, it is an object of the present invention to provide a sofa with which the locked state is easily recovered on a middle inclination posture on way of inclination of the rest portion from the lock-releasing posture, and angle adjustment is conducted on random middle inclination postures to keep the posture of the rest portion.
This object is solved according to the present invention by sofa including features of claim 1.
The present invention will be described with reference to the accompanying drawings, in which:

Figure 1 is perspective view of an embodiment of the present invention;
Figure 2 is a perspective view of an embodiment of the present invention;
Figure 3 is a perspective view of a sofa of the present invention with partial see-through;
Figure 4 is a perspective view of the sofa of the present invention with partial see-through;
Figure 5 is an exploded perspective view showing an embodiment of an angle-adjustable hinge;
Figure 6 is a perspective view of a half product before assembly of the angle-adjustable hinge is completed;
Figure 7 is a cross-sectional view of figure 6;
Figure 8 is a perspective view of an assembled and used state of the angle-adjustable hinge;
Figure 9 is a cross-sectional view of figure 8;
Figure 10A is a whole cross-sectional view of the angle-adjustable hinge;
Figure 10B is an enlarged cross-sectional view of a principal portion of the angle-adjustable hinge;
Figure 11A is a whole cross-sectional view of the angle-adjustable hinge;
Figure 11B is an enlarged cross-sectional view of the principal portion of the angle-adjustable hinge;
Figure 12A is a whole cross-sectional view of the angle-adjustable hinge;
Figure 12B is an enlarged cross-sectional view of the principal portion of the angle-adjustable hinge;
Figure 13A is a whole cross-sectional view of the angle-adjustable hinge;
Figure 13B is an enlarged cross-sectional view of the principal portion of the angle-adjustable hinge;
Figure 14A is a whole cross-sectional view of the angle-adjustable hinge;
Figure 14B is an enlarged cross-sectional view of the principal portion of the angle-adjustable hinge;
Figure 15A is a whole cross-sectional view of the angle-adjustable hinge;
Figure 15B is an enlarged cross-sectional view of the principal portion of the angle-adjustable hinge;
Figure 16A is a whole cross-sectional view of the angle-adjustable hinge;
Figure 16B is an enlarged cross-sectional view of the principal portion of the angle-adjustable hinge;
Figure 17A is a front view showing an elastic portion;
Figure 17B is a cross-sectional side view showing the elastic portion under non-compressed state;
Figure 17C is a cross-sectional side view showing the elastic portion under compressed state;
Figure 18 is an enlarged view of a principal portion of the sofa; and
Figure 19 is an enlarged view of the principal portion of the sofa.

Preferred embodiments of the present invention will now be described with reference to the accompanying drawings.
As shown in figure 1 through figure 4, a sofa of the present invention is provided with a sofa fixation portion 45 having 4 legs, and seat portions 47 and back portions 46 are set to the sofa fixation portion 45. An armrest portion 49, connected to the sofa fixation portion 45 with an angle-adjustable hinge 3 and freely angle-adjusted, is disposed on a side of the seat portion 47 and the back portion 46. The sofa is switched between a locked state in which the armrest portion 49 is oscillatable to a standing direction A and oscillation in an inclining direction B of the armrest portion 49 is restricted, and a free state in which the oscillation in the inclining direction B is made possible by nullifying the restriction with a standing lock-releasing posture T₀ (refer to figure 18) of the armrest portion 49. Although the lock-releasing posture T₀ is shown in figure 18 as to have vertical standing posture, it is also preferable to modify that the lock is released with an inclined standing posture.
As shown in figure 18, in the free state, the posture of the armrest portion 49 in a random middle inclination posture T₁, on way of oscillation in the inclining direction B from the standing lock-releasing posture T₀ to a lowest laid posture T₂ for recovering the lock, is kept by recovering the locked state with a return action M₂ of a predetermined small angle θ in the standing direction A. Although a case that the lowest laid posture T₂ is horizontal is shown in figure 18, the lowest laid posture T₂ may be 30° , 40° , etc.
As shown in figure 3 and figure 4, the armrest portion 49 is including an armrest supporting frame 49B and composed by covering the armrest supporting frame 49B with cushion and cover. The armrest supporting frame 49B is connected to the sofa fixation portion 45 with 2 angle-adjustable hinges 3.
As shown in figure 19, even if excessive load is on the armrest portion 49 under the locked state and a lock-releasing posture T₀' is slightly inclined further in the inclining direction B beyond the normal lock-releasing posture T₀ (refer to figure 18), the armrest portion 49, under the free state, is made locked state by recovering the restriction on random middle inclination posture T₁ or T₁', on way of inclination in the inclining direction B from the standing lock-releasing posture T₀' with the return action M₂ of a predetermined small angle θ in the standing direction A, and angle adjustment of the armrest portion 49 is started by the recovery of the locked state to keep the posture of the armrest portion 49. That is to say, in a case that plastic deformation and shear on fixed portions of the angle-adjustable hinge 3 are generated, the lock-releasing posture T₀' of the armrest portion 49 is slightly inclined further in the inclining direction B beyond the normal lock-releasing posture T₀ (refer to figure 18) and lowest oscillation position of the armrest portion 49 is lower than the lowest laid posture, the lock is recovered and angle adjustment of the armrest portion 49 can be started on random middle inclination posture T₁ and under a state not inclined further than the lowest oscillation position (mark T₁').
And, the sofa of the present invention is provided with a headrest portion 48 connected to an upper end of the back portion 46 with an angle-adjustable hinge 3 and freely angle-adjusted. The sofa is switched between a locked state in which the headrest portion 48 is oscillatable to a standing direction A and oscillation in an inclining direction B of the headrest portion 48 is restricted, and a free state in which the oscillation in the inclining direction B is made possible by nullifying the restriction with a standing lock-releasing posture T₀ of the headrest portion 48. As shown in figure 3 and figure 4, the headrest portion 48 is including a headrest supporting frame 48B and composed by covering the headrest supporting frame 48B with cushion and cover. The headrest supporting frame 48B is connected to the upper end of the back portion 46 with 2 angle-adjustable hinges 3.
In the sofa of the present invention, in the free state, the posture of the headrest portion 48 in a random middle inclination posture T₁, on way of oscillation in the inclining direction B from the standing lock-releasing posture T₀ to a lowest laid posture T₂ for recovering the lock, is kept by recovering the locked state with a return action M₂ of a predetermined small angle θ in the standing direction A. Although a case that the lowest laid posture T₂ is horizontal is mainly explained below, the lowest laid posture T₂ , not restricted to being horizontal, may be set at a desired angle.
Especially, in a case that plastic deformation and shear on fixed portions of the angle-adjustable hinge 3 are generated, the lock-releasing posture T₀' of the headrest portion 48 is slightly inclined further in the inclining direction B beyond the normal lock-releasing posture T₀ and lowest oscillation position of the headrest portion 48 is lower than the horizontal laid posture, the lock is recovered and angle adjustment of the headrest portion 48 can be started on random middle inclination posture T₁ and under a state not inclined further than the lowest oscillation position (mark T₁' ).
The sofa of the present invention can be also used as a sofa bed with reclining of the back portion 46.
The angle-adjustable hinge 3 is hereby described in detail.
As shown in figures 5 through 9, the angle-adjustable hinge 3 is provided with a first member 1 in which a disc body 16 having a non-circular through hole 23 is held as to freely rotate around an oscillation axis C and a second member 2 from which a non-circular shaft portion 20, may be inserted to the through hole 23 on any of both sides in the axis direction. The first member 1 and the second member 2 are connected to be relatively oscillatable by insertion of the shaft portion 20 to the through hole 23. A gear portion 4 is formed on a peripheral edge of the disc body 16, and a floating wedge member 6, of which one side is toothed face 7 engaging with the gear portion 4 and another side is a contact face 9 which contacts a wedge face 8 formed on the first member 1 side, is provided.
The first member 1 is provided with a pair of facing plate portions 13 to hold the disc body 16 and an attachment portion 17 to be fixed to the armrest portion 49 or the headrest portion 48. A circular supporting hole 21 and a (wedge-shaped) window portion 5 for forming a wedge-shaped space to hold the floating wedge member 6 are formed through each of the facing plate portions 13. Further, a hitching small protrusion 33 and a pivot shaft portion 27 of small diameter are protruding from an outer side of the facing plate portion 13. The (wedge-shaped) window portion 5 has the wedge face 8 of arc shape to form a retreat space 25 to store the floating wedge member 6 as to part from the gear portion 4. Circular low protrusions 24, insertable to the circular supporting holes 21, are protruding from left and right sides of the disc body 16. The gear portion 4 is formed for a range of 1/3 to 1/4 of the peripheral edge of the disc body 16 (a range of center angle of 90° to 120° ), and a protruding portion (timing protrusion) 28 is formed on 2 points, namely, a beginning portion and an end portion of the gear portion 4. The disc body 16 is held as to freely rotate by the pair of facing plate portions 13 with the circular low protrusions 24 inserted to the circular supporting holes 21, and the facing plate portions 13 are disposed mutually parallel and fixed (riveted) to the attachment portion 17 with rivets 42..
The second member 2 has an attachment portion 18 to be fixed to the sofa fixation portion 45 or the back portion 46, and the non-circular shaft portion 20 is protruding from one end of the attachment portion 18. The shaft portion 20 has a female screw hole 44. Plural small holes 29 for bolts and screws are formed on the attachment portions 17 and 18.
The floating wedge member 6 is held within the wedge-shaped space formed with the pair of facing plate portions 13 (the window portions 5) and the gear portion 4, and both side end portions are protruding (left and right) from the window portions 5. Preferably, 13 to 20 gear teeth are formed on the toothed face 7, and, 40 or more (of small pitch) gear teeth, further preferably 45 to 65 gear teeth, are formed on the gear portion 4 of the disc body 16. Therefore, the number of stages of angle adjustment can be more than 40. A spring (elastic) member 26 to elastically push the floating wedge member 6 to the gear portion 4 is provided on the contact face 9 side (the attachment portion 17 side) of the floating wedge member 6.
As shown in figures 10A and 10B, in an engaged state in which the contact face 9 of the floating wedge member 6 and the toothed face 7 and the gear portion 4 engage, the relative oscillation of the first member 1 and the second member 2 in the direction B is restricted (stopped). And, as shown in figures 13A and 13B, the first member 1 and the second member 2 are relatively oscillated in another direction A to set a lock-releasing position P₀, and the floating wedge member 6 is moved and parted from the gear portion 4 to make a retreat state in which the engagement of the gear portion 4 and the toothed face 7 is released thereby. Under the retreat state shown in figures 14A and 14B, the first member 1 and the second member 2 can be relatively oscillated in the direction B. In the present invention, it is called "free oscillation (M₁)" that the lock (restriction on oscillation) of the first member 1 and the second member 2 is released and the first member 1 and the second member 2 (relatively) oscillate in the direction B.
The angle-adjustable hinge 3 is provided with a recovery means 10 which recovers the floating wedge member 6 in the retreat state to the engaged state with the gear portion 4 by the return action M₂ of the predetermined small angle θ in the direction A during the free oscillation M₁ in which the first member 1 and the second member 2 in the lock-releasing position P₀ are relatively oscillated in the direction B as shown in figures 15A and 15B.
The recovery means 10 is provided with a ring member 12 which rotates against the facing plate portion 13 within a range of the predetermined small angle θ , an oscillating member 11, of which one end 11a is interlockingly connected to the ring member 12 and freely oscillating within a predetermined angle range with a middle portion as a fulcrum and another end 11b is disposed as to be pressed to the floating wedge member 6 in the retreat state, and a press-fit frictional member 15, having a non-circular fitting hole 19 fit to the shaft portion 20 to rotate unitedly with the shaft portion 20, and having an elastic portion 14 elastically pushing the ring member 12 in an axial inner direction and sliding on the ring member 12.
Under the retreat state shown in figures 14A and 14B, the floating wedge member 6 keeps the retreat state (kept on a first position V₁ on which the end 11b of the oscillating member 11 does not press the floating wedge member 6) during the free oscillation M₁ of the first member 1 and the second member 2 in the direction B. By the return action M₂ in the direction A as shown in figures 15A and 15B, the ring member 12 is rotated by frictional force with the elastic portion 14 for the predetermined small angle θ , and the oscillating member 11 (moving to a second position V₂ on which the end 11b presses the floating wedge member 6) moves the floating wedge member 6 (as to push out of the retreat space 25) to make the gear portion 4 and the toothed face 7 engaged.
As shown in figure 5, the ring member 12 is formed as a ring having a circular hole portion 22 to which the shaft portion 20 is inserted, and, a hitching concave portion 34 corresponding to the small protrusion 33 and an arc-shaped notched portion 32 are formed on the peripheral edge portion. The ring member 12 is hitching the small protrusion 33 to the hitching concave portion 34 movably (with backlash), and rotatable within the range of the predetermined small angle θ around the oscillation axis C as the center.
The oscillating member 11 is composed of metal (or resin) of high rigidity formed approximately V-shape, and the end 11a (formed into a short cylindrical column) is fit to the arc-shaped notched portion 32 and interlockingly connected to the ring member 12. A pivot hole portion 31 is formed on a middle portion of the oscillating member 11 to insert the pivot shaft portion 27. For example, the oscillating member 11 is pivoted to (the outer face side of) the facing plate portion 13 as the end 11a of the oscillating member 11 is moved up and down, and the corresponding other end 11b oppositely moves down and up like a seesaw with the pivot shaft portion 27 as a fulcrum.
As shown in figure 17A, the elastic portion 14 is formed as a ring, and plural small convex portions 37 are protruding from one end face. The elastic portion 14 is composed of elastically deformable resin (or metal), and another end face of the elastic portion 14 is a sliding face 39 to slide (elastically push in the axial inner direction in an assembled and used state described later) on the ring member 12.
In figure 5, a press-fit frictional member 15 is formed as a ring, and plural small concave portions 38 are formed corresponding to the small convex portions 37 of the elastic portion 14. The elastic portion 14 is attached with the plural small convex portions 37 inserted to the small concave portions 38 as to rotate (co-rotate) unitedly with the press-fit frictional member 15. It is also preferable to form the elastic portion 14 unitedly with the press-fit frictional member 15.
In a half product state shown in figures 6 and 7, the press-fit frictional member 15 is disposed on an outer side of each ring member 12, and the elastic portion 14 contacts the outer face of the ring member 12. As shown in figure 17B, the sliding face 39 of the elastic portion 14 is arc-shaped under non-compressed state. The press-fit frictional member 15 is held by a cover member 40. The cover member 40 is composed of a pair of (two-piece) cover half bodies 41 of resin. An insertion pin and an insertion hole are formed on the cover half body 41 on assembly corresponding positions (refer to figure 5). The cover member 40 covers and very compactly stores the press-fit frictional members 15, the ring members 12, the oscillating member 11, the facing plate portions 13, the disc body 16, and the floating wedge member 6.
In the assembled and used state shown in figures 8 and 9, the shaft portion 20 of the second member 2 is inserted to the through hole 23 and the fitting hole 19, a bolt 43 is screwed into the female screw hole 44 to insert the first member 1 to the second member 2. The bolt 43 is inserted to a washer 51. In the press-fit frictional members 15, the elastic portions 14 are elastically deformed by compression of fastening force of the bolt 43. As shown in figure 17C, the sliding face 39 of the elastic portion 14 is made flat face under compressed state and press-fit to the ring member 12. That is to say, the press-fit frictional members 15 are elastically pushing the ring members 12 with the elastic portions 14 in the axial inner direction.
Next, function of the angle-adjustable hinge 3 is described.
In the engaged state shown in figures 10A and 10B, the toothed face 7 of the floating wedge member 6 is engaged to the gear portion 4, and the contact face 9 contacts the wedge face 8 to restrict (stop) the relative oscillation of the first member 1 and the second member 2 in the direction B. The explanation below is under a condition that the second member 2 is attached to the sofa fixation portion 45 or the back portion 46, the first member 1 is attached to the armrest portion 49 or the headrest portion 48, and the first member 1 is oscillated against the (fixed) second member 2.
Next, as shown in figures 11A and 11B, when the first member 1 is oscillated in the standing direction A, the floating wedge member 6 slightly moves within the window portion 5, and the contact face 9 is parted from the wedge face 8 to form a slight gap d. When the first member 1 is oscillated in the standing direction A further, the guiding sloped face 35 of the floating wedge member 6 mounts the staged portion 36 of the window portion 5, the toothed face 7 of the floating wedge member 6 is parted from the gear portion 4 by the gap d, and the toothed face 7 goes over the gear portion 4 with click sound. Even if the first member 1 is made oscillate in the inclining direction B against the second member 2, the oscillation is restricted (stopped) by wedge function of the floating wedge member 6, and the posture of the first member 1 is kept (held fixed). Although rotational force works on the ring member 12 in an arrow N direction (anticlockwise direction in figures) against the facing plate portion 13 by frictional force with the elastic portion 14 (the press-fit frictional member 15) in the oscillation in the standing direction A, the ring member 12 is hitched (against the facing plate portion 13) by the small protrusion 33 which contacts the (hitching) concave portion 34.
As shown in figures 12A and 12B, when the first member 1 is oscillated in the standing direction A further, the toothed face 7 repeatedly goes over the gear portion 4, a protruding portion 28 disposed on an end portion of the gear portion 4 contacts the floating wedge member 6.
As shown in figures 13A and 13B, when the first member 1 is oscillated in the standing direction A further to a standing lock-releasing position P₀ under the state in which the protruding portion 28 contacts the floating wedge member 6, the floating wedge member 6 is pushed by the protruding portion 28 and moved to the retreat space 25 to be stored, and the toothed face 7 is parted from the gear portion 4 (retreat state is made). In this case, the other end 11b of the oscillating member 11 is pushed by the floating wedge member 6 and oscillated. This position is the first position V₁. The oscillating member 11 oscillates to the first position V₁, the end 11a pushes the ring member 12, and the ring member 12 rotates in an arrow R direction (clockwise direction in figures) only for the small angle θ .
Under the retreat state, the floating wedge member 6 is stored within the retreat space 25, and the engagement of the toothed face 7 and the gear portion 4 is released. Therefore, the lock (restriction on oscillation) in the inclining direction B is released, and the free oscillation of the first member 1 in the inclining direction B is made possible.
Next, as shown in figures 14A and 14B, the ring member 12, although receiving rotational force in the arrow R direction by frictional force of the elastic portion 14, is stopped by the small protrusion 33 which contacts the (hitching) concave portion 34. That is to say, during the free oscillation M₁ of the first member 1 in the inclining direction B, the oscillating member 11 is held on the first position V₁ and keeping the posture without oscillation, and the floating wedge member 6 is kept under the retreat state.
In figures 15A and 15B, when the return action M₂ in the direction A for the predetermined small angle θ is conducted during the free oscillation M₁ of the first member 1 in the inclining direction B, the ring member 12, receiving rotational force in the arrow N direction (anticlockwise direction in figures) by frictional force of the elastic portion 14, is rotated. The oscillating member 11, of which end 11a is pushed by the rotating ring member 12, is oscillated. This position is the second position V₂. The oscillating member 11 pushes out the floating wedge member 6 with the other end 11b to move out of the retreat space 25. The floating wedge member 6 pushed out of the retreat space 25 is pressed to the gear portion 4 by the spring member 26, and the engaged state, in which the toothed face 7 is engaged to the gear portion 4, is made (returning to the locked state).
In figures 16A and 16B, the engaged state, in which the toothed face 7 of the floating wedge member 6 is engaged to the gear portion 4 and the contact face 9 contacts the wedge face 8, is made, the wedge function of the floating wedge member 6 is recovered to stop the oscillation of the first member 1 in the inclining direction B. As described above, the locked state is easily recovered on random positions during the free oscillation of the first member 1 from the lock-releasing position P₀ to the inclining direction B, the oscillation of the first member 1 is restricted on a desired middle inclining position to hold the posture, and angle adjustment is started by oscillation from the middle inclining position to the standing direction A.
The angle-adjustable hinge 3 can be modified. For example, not having the (wedge-shaped) window portion 5, a plate piece member, etc. may be used instead to press the contact face 9 of the floating wedge member 6. And, design and dimensions of the cover member 40 may be changed.
And, the number of the gear teeth of the toothed face 7 and the gear portion 4 may be more than or less than the above-described numbers depending on cases. And, forming method of the gear teeth may be freely selected from various plastic (press) works, die casting, roulette work, etc.
Especially, the oscillating member 11 may be freely modified as far as the member 11 is interlocking to move the floating wedge member 6 in opposite direction (clockwise direction) to push out (take out or draw out) of the retreat state along with the rotation of the ring member 12 (in anticlockwise direction) for the small angle θ from figures 14A and 14B to figures 15A and 15B.
And, the shaft portion 20 is formed as a regular hexagonal column, and the through hole 23 is also regular hexagonal as to correspond to the shaft portion 20. The shaft portion 20 and the through hole 23 may be various polygonal or other configurations as far as non-circular and mutually fitting.
And, the present invention can be modified. For example, the armrest portion 49 may be connected to the seat portion 47.
As described above, the sofa relating to the present invention can recover nullified restriction and locked state by slight return in the standing direction A on a random middle inclination posture T₁ on way of inclination of the armrest portion 49 in the inclining direction B in free state because in a sofa provided with the armrest portion 49, connected to the sofa fixation portion 45 with the angle-adjustable hinge 3 and freely angle-adjusted, and switched between the locked state in which the armrest portion 49 is oscillatable to the standing direction A and oscillation in the inclining direction B of the armrest portion 49 is restricted, and the free state in which the oscillation in the inclining direction B is made possible by nullifying the restriction with the standing lock-releasing posture T₀ of the armrest portion 49, the posture of the armrest portion 49 in the random middle inclination posture T₁ in the free state, on way of oscillation in the inclining direction B from the standing lock-releasing posture T₀ to the horizontal laid posture T₂ for recovering the lock, is kept by recovering the locked state with the return action M₂ of the predetermined small angle θ in the standing direction A. That is to say, after the restriction is nullified by moving the armrest portion 49 to the standing lock-releasing posture T₀, the locked state can be recovered without making the horizontal laid posture T₂, the armrest portion 49 can be held with random middle inclination posture T₁, and angle adjustment can be started with the random middle inclination posture T₁. That is to say, solving the above-described problem that the armrest portion 49 can't recover the locked state by interference (contact) with the obstacles, angle adjustment can be easily and swiftly conducted.
And, the sofa relating to the present invention can recover nullified restriction and locked state by slight return in the standing direction A on a random middle inclination posture T₁ on way of inclination of the headrest portion 48 in the inclining direction B in free state because in a sofa provided with the headrest portion 48 connected to the upper end of the back portion 46 with the angle-adjustable hinge 3 and freely angle-adjusted, switched between the locked state in which the headrest portion 48 is oscillatable to the standing direction A and oscillation in the inclining direction B of the headrest portion 48 is restricted, and the free state in which the oscillation in the inclining direction B is made possible by nullifying the restriction with the standing lock-releasing posture T₀ of the headrest portion 48, in the free state, the posture of the headrest portion 48 in the random middle inclination posture T₁, on way of oscillation in the inclining direction B from the standing lock-releasing posture T₀ to the horizontal laid posture T₂ for recovering the lock, is kept by recovering the locked state with the return action M₂ of the predetermined small angle θ in the standing direction A. That is to say, after the restriction is nullified by moving the headrest portion 48 to the standing lock-releasing posture T₀, the locked state can be recovered without making the horizontal laid posture T₂, the headrest portion 48 can be held with random middle inclination posture T₁, and angle adjustment can be started with the random middle inclination posture T₁. That is to say, solving the above-described problem that the headrest portion 48 can't recover the locked state by interference (contact) with the obstacles, angle adjustment can be easily and swiftly conducted.

Claims

A sofa provided with a rest portion (48, 49), connected to a sofa portion (45, 46) with an angle-adjustable hinge (3) and freely angle-adjusted, and switched between a locked state in which the rest portion (48, 49) is oscillatable to a standing direction (A) and oscillation in an inclining direction (B) of the rest portion (48, 49) is restricted, and a free state in which the oscillation in the inclining direction (B) is made possible by nullifying the restriction with a standing lock-releasing posture (T₀) of the rest portion (48, 49); characterized by that the posture of the rest portion (48, 49) in a random middle inclination posture (T₁) in the free state, on way of oscillation in the inclining direction (B) from the lock-releasing posture (T₀) to a lowest laid posture (T₂) for recovering the lock, is kept by recovering the locked state with a return action (M₂) of a predetermined small angle (θ) in the standing direction (A).
The sofa according to claim 1, wherein the rest portion is an armrest portion (49) and the sofa portion is a sofa fixation portion (45).
The sofa according to claim 1, wherein the rest portion is a headrest portion (48) and the sofa portion is an upper edge of a back portion (46).