CHAIR
An object of this invention is to provide a chair having less sliding resistance, less abrasion and less noise with prevention of partially contacting each component while the chair is making a rocking movement. The chair comprises a support frame 4 supported by a support rod 12, a back frame 5 that can make an inclining movement relative to the support frame 4, a seat frame 6 that is related to the support frame 4 and the back frame 5 so as to make a movement in conjunction with the back frame 5 toward a direction along the inclining movement of the back frame 5, and a spring case 71 arranged along the seat frame 6 in a state that a proximal point part of the spring case 71 is supported by the support frame 4 so as to introduce a spring force against a force of an interlocking movement of the seat frame 6 and the back frame 5 to the support frame 4, wherein a spring 72 is so arranged to be compressed by a movement of the seat frame 6 relative to the spring case 71, and a slide guide part 66 to make the spring case 71 and the seat frame 6 line-contact in a direction orthogonal to the back and forth direction is arranged between the spring case 71 and the seat frame 6.
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This invention relates to a chair used in an office or the like, and more specifically to a chair wherein a sliding resistance between a seat frame and a spring case is reduced.
BACKGROUND ARTConventionally, as a chair provided with a so-called synchronized rocking function wherein a seat sinks while making a sliding movement backward in conjunction with a backward inclining movement of the back, a chair has been known as shown in, for example, the patent document 1.
The chair comprises a support frame supported by a support rod, a back frame that can make a standing and inclining movement relative to the support frame, a seat frame related to the support frame and the back frame so as to make a movement in conjunction with the back frame along the standing and inclining movement of the back frame, and a spring case arranged along the seat frame in a state that a proximal point part of the spring case is supported by the seat frame so as to introduce a spring force against the coupled movement of the seat frame and the back frame to the support frame, and the spring is so arranged to compress due to a movement of the seat frame relative to the spring case.
The spring case comprises a contact surface arranged on the outside of the spring and extending in the back and forth direction, and it is so arranged that the contact surface can make a sliding movement with a corresponding contact surface that extends in the back and forth direction of the seat frame. As mentioned, if the contact area between the spring case and the seat frame is increased, it is possible to reduce the pressure applied to the seat frame and the spring case each other while the seat frame and the back frame are making a synchronized movement, resulting in enabling to reduce abrasion and noise on the contact surface.
PRIOR ART DOCUMENT Patent Document
- Patent document 1: Japanese Unexamined Patent Application Publication Number 2010-507399
However, if the seat frame and the spring case make a proximal contact, a sliding resistance tends to increase as a whole although the pressure between them decreases. In addition, since a direction of the back and forth movement of the seat frame is determined by a link mechanism making use of the support frame, the seat frame and the back frame, a guide such as the above-mentioned contact surface is required to form in parallel to a moving direction of the seat frame in order to reduce abrasion or noise generated by a partial contact. As a result, there is a problem that it requires a high accuracy in processing and assembling the chair.
The present claimed invention intends to solve all of the problems effectively.
Means to Solve the ProblemsIn order to attain this object, the following means are provided.
More specifically, the chair in accordance with this invention comprises a support frame supported by a support rod, a back frame that can make an inclining movement relative to the support frame, a seat frame that is related to the support frame and the back frame so as to make a movement in conjunction with the back frame toward a direction along the inclining movement of the back frame, and a spring case arranged along the seat frame in a state that a proximal point part is supported by the support frame so as to introduce a spring force against a force of an interlocking movement of the seat frame and the back frame to the support frame, and is so arranged that the spring is compressed by a movement of the seat frame relative to the spring case, and is characterized by that a slide guide part to make the spring case and the seat frame line-contact in a direction orthogonal to a back and forth direction or point-contact is arranged between the spring case and the seat frame.
In accordance with this arrangement, since the area of the part where the spring case makes contact with the seat frame is limited, it is possible to expect to reduce a siding resistance effectively as a whole. In addition, since the spring case and the seat frame only make a line-contact each other in the direction orthogonal to the direction of the relative movement of the spring case and the seat frame or a point-contact each other, even though the spring case is not arranged in parallel with the seat frame, it is possible for the spring case and the seat frame to contact each other so that it does not require a higher accuracy in processing and assembling the spring case and the set frame compared with a case wherein the spring case and the seat frame make a proximal contact.
Furthermore, in case that the slide guide part is so arranged that the proximal point part of the spring case is supported by the support frame rotatably around a transversal shaft and a base spring bearing is formed on an extending part locating at a distal end side of the spring case, a movable spring bearing is arranged at the seat frame side to face the base spring bearing and a spring is arranged between the base spring bearing and the movable spring bearing, it is possible to use the slide guide part more preferably.
In addition, also in case that the support frame and the spring case can be mounted and dismounted at an assembled angle at least more upright than the used angle, and a cam surface is arranged for the support frame to urge the movable spring bearing toward a direction that the spring is compressed in accordance with a movement of the spring case from the assembled angle to the used angle, it is possible to use the above-mentioned arrangement more preferably.
Furthermore, in order to make the chair compact as a whole, it is more preferable that a void part is formed on a part of the seat frame, the spring case is housed in the void part at generally the same height as that of the seat frame and a first slide guide part extending in the lateral direction is integrally formed with the seat frame at a position to press the top surface of the spring case.
In addition, even though the spring case and the seat frame are not arranged strictly in parallel, in order to keep a positional relationship between the spring case and the seat frame appropriately it is more preferable that the first slide guide part is arranged only at one position along the back and forth direction.
Furthermore, in order to support the distal end of the spring case appropriately without less resistance in the lateral direction, it is preferable that the spring case is housed between the right and left walls of the seat frame, and a second slide guide part extending in the vertical direction is arranged on either the right and left walls of the seat frame or the right and left walls of the spring case facing the right and left walls of the seat frame.
In addition, even though the spring case and the seat frame are not arranged strictly in parallel, in order to make it possible to keep a positional relationship between the spring case and the seat frame appropriately, it is more preferable that the second slide guide part is arranged only at one position along the back and forth direction.
Furthermore, in order to make it easier to incorporate the spring case into the seat frame, it is preferable that the void part opens rearward of the seat frame and the spring case can be mounted on and dismounted from the void part of the seat frame from the rearward.
In addition, in order to form the slide guide part easily and appropriately, it is preferable that the slide guide part is a projecting part whose distal end is curved to form a convex and is integrally formed with the spring case or the seat frame.
Effect of the InventionIn accordance with the above-mentioned presently claimed invention, it is possible to provide a chair that can reduce a sliding resistance due to a synchronized movement between the seat frame and the spring case without requiring high accuracy in processing and assembling the chair.
One embodiment of this invention will be described with reference drawings.
A chair of this embodiment is, as shown in
In the specification of this invention, a direction from a center of the chair to a back 31 is set as a rear direction, and the opposite direction is set as a front direction. In other words, the left side in
The support frame 4 is, as shown in
The back frame 5 is, as shown in
The seat frame 6 is, as shown in
The seat frame 6 of this embodiment comprises the void part 65 as mentioned above, however, it is not necessarily the case that the void part 65 is in a shape of opening upward, and may be in a shape of closing upward or opening downward.
In addition, the inside wall 612 and the outside wall 613 of the seat frame 6 extend further rearward from the bottom wall 616, and a downward facing opening concave part 64 in a shape of a cylinder from which a part is cut is formed on the downward of the extending part. An innermost recess of the downward facing opening concave part 64 is a bearing surface along a partial cylindrical surface, and its opening end faces front downward.
As shown in
In addition, a reactive force mechanism 7 is formed so as to accumulate a spring force against an interlocking movement of the seat frame 6 and the back frame 5 to the support frame 4.
The reactive force mechanism 7 is so arranged, as shown in
As its detail is described later, a front end part of the spring case 71 makes an engagement with the support frame 4 and the spring case 71 is restricted from moving in a vertical direction and a lateral direction by the seat frame 6, and furthermore a rear end part of the spring case 71 is also restricted from moving in the vertical direction and the lateral direction by the seat frame 6 with forming a lock mechanism 8, to be described later. As a result, the spring case 71 makes a vertical movement integrally with the seat frame 6 and only a movement in the back and forth direction relative to the seat frame 6 is allowed to make for the spring case 71.
Concrete structure will be described.
The spring case 71 is, as shown in
The spring case 71 is restricted from moving upward by making an engagement with the support frame 4 through the bearing member 74 at the base point part 716 of the front end part of the spring case 71 and by placing the top lid 615 of the seat frame 6 on top of the top wall 711. In addition, near the front end part of the spring case 71, the right and left side walls 712 are restricted from making a relative movement in the right and left directions by the inside wall 612 of the seat frame 6. Since the rotation slide engaging part 91 is formed by engaging the rotation slide bore 62 of the seat frame 6 with the front transversal shaft 44 of the support frame 4, the seat frame 6 is restricted from making a vertical movement at this point by the support frame 4. As a result, the front end part of the spring case 71 is restricted from making a vertical movement by being sandwiched between the top lid 615 of the seat frame 6 and the front transversal shaft 44 of the support frame 4. With this arrangement, the front end part of the spring case 71 is restricted from making a movement in a direction except for the back and forth direction relative to the seat frame 6.
Furthermore, with the arrangement that the movable plate part 714 as being the rear end part of the spring case 71 forms a lock mechanism, to be described later, together with the seat frame 6, the movable plate part 714 is restricted from making a movement vertically and laterally relative to the seat frame 6. As a result of this, it is possible for the spring case 71 as a whole to make only a movement in the back and forth direction relative to the seat frame 6.
The spring case 71 can be inserted into or dismounted from the opening end 69 locating at a rear side of the void part 65 of the seat frame 6, and is in the same height as that of the seat frame 6 in a state that the spring case 71 is housed in the void part 65 of the seat frame 6 and the right and left side walls 712 of the spring case 71 are housed between the right and left inside walls 612 of the seat frame 6. While the bearing member 74 forms an engaging part 94, as shown in
The first slide guide part 66 is a projecting part that is integrally formed on a top edge of the inside wall 612 of the seat frame 6 and that extends in parallel to the bottom wall 616 of the seat frame 6, and the projecting part is curved to form a gentle convex. In a state that the spring case 71 is incorporated into the seat frame 6 as shown in
In addition, as shown in
As shown in
As shown in
The movable spring bearing 73 is a spring bearing extension arm 731 integrally extending from a spring abutting surface 733, and the movable spring bearing 73 faces the base spring bearing 75 in a state wherein a distal end 734 of the spring bearing extension arm 731 passes inside of the spring 72 and then is inserted into a through bore 751 of the base spring bearing 75. The spring abutting surface 733 is a part of a channel-shaped displacement transmission member 732 and plays a role to transmit a slide displacement of the seat frame 6 in accordance with a backward inclining movement of the back frame 5 to the spring 72 through a reactive force adjusting part 76. The reactive force adjusting part 76 transforms, as shown in
A procedure to assemble the support frame 4, the seat frame 6, the back frame 5 and the spring case 71 will be explained by the use of
The bearing member 74 of the spring case 71 is mountable on and dismountable from a direction crossing to the front transversal shaft 44 of the support frame 4 at an assembled angle at least more upright than a used angle as shown in
As shown in
As shown in
Since the initial reactive force of the spring 72 in a state shown in
Especially, as shown in
Especially, as shown in
Furthermore, this embodiment is provided with a lock mechanism 8, as shown in
The lock mechanism 8 comprises a stopper case 81 mounted inside of the seat frame 6, a stopper member 82 having a plate shape housed in the stopper case 81, a movable plate part 714 having an engaging bore 715 that is arranged in the rearward of the spring case 71 and into which the stopper member 82 is inserted, and a reciprocatory moving mechanism 85 that reciprocates the stopper member 82 vertically. With the arrangement of the lock mechanism 8, since the movable plate part 714 as being a rear end part of the spring case 71 is inserted between the stopper case 81 and the seat frame 6, the movable plate part 714 is restricted from making a vertical movement. In addition, as mentioned above, the right and left side walls 712 of the spring case 71 is housed between the right and left inside walls 612 of the seat frame 6, and the spring case 71 is restricted from making a relative movement also in the right and left directions by the second slide guide part 67 near the rear end part of the spring case 71. As a result, the rear end part of the spring case 71 is incapable of making a movement both vertically and right and left relative to the seat frame 6, and is allowed to make a movement in the back and forth directions only. The movement of the spring case 71 in the back and forth directions can be fixed at a predetermined position by the behavior of the lock mechanism 8.
The reciprocatory moving mechanism 85 comprises a torsion coil spring 83 to give a vertical operational force to the stopper member 82 and an operation lever 84. The stopper member 82 is integrally made of a steel or resin material into a plate shape having two rectangular projecting parts 821 on its bottom part, and is provided with an insertion bore 822 near its top part to mount an end part 831 of the torsion coil spring 83. The stopper case 81 is made of a steel or resin material integrally formed or by a folding process into a channel shape comprising three flat surfaces, namely a front wall 811 and a rear wall 812 as being a pair of facing walls connected by a bottom wall 813 as being a fixing plate part, and a slit-shaped engaging bore 814 having almost the same shape as that of the projecting part 821 locating on the bottom part of the stopper member 82 opens on the bottom wall 813 as shown in
In addition, the engaging bore 715 on the movable plate part 714 locating at the rear side of the spring case 71 is also a slit having almost the same shape as that of the projecting part 821 locating on the bottom part of the stopper member 82, and a plurality of engaging bores 715 are arranged at a predetermined pitch in the back and forth direction. The slit-shaped engaging bore 618 having almost the same as that of the projecting part 821 is arranged at a position corresponding to the projecting part 821 of the stopper member 82.
As shown in
The stopper case 81 is fixed near a rear side of the seat frame 6, the stopper member 82 is arranged inside of the stopper case 81 in a state of being able to make a vertical movement while being guided by one surface of the stopper member 82 that makes an abutting contact with the front wall 811, and the working end 842 of the operation lever 84 to operate the stopper member 82 is inserted into the stopper case 81 from its lateral direction so that the stopper member 82 and the working end 842 of the operation lever 84 is tightly arranged in the stopper case 81. A reason why one surface of the stopper member 82 makes an abutting contact with the front wall 811 of the stopper case 81 is to stabilize a position of the stopper member 82 by making use of the front wall 811 as a guide together with the working end 842 tightly arranged. The stopper member 82 may be arranged to make an abutting contact with the rear wall 812 of the stopper case 81. With this arrangement, the same effect can be obtained.
In addition, the torsion coil spring 83 is mounted between the stopper member 82 and the operation lever 84 to be housed in the recess part 845 arranged near the working end 842 of the operation lever 84, and two spring ends 831 each projecting opposite direction each other in a direction orthogonal to the coil direction of the spring are inserted into the insertion bore 822 of the stopper member 82 and the insertion bore 843 of the operation lever 84 respectively. Furthermore, the operation end 841 of the operation lever 84 passes the lever insertion bore 691 arranged on the side wall of the seat frame 6 so as to extend to a position accessible for a person, and the mounting shaft 844 makes an engagement in a rotatable manner with the lever mounting part 692 that grips the mounting shaft 844 and that is arranged on the outer surface of the outside wall 613 of the seat frame 6.
With this arrangement, the working end 842 of the operation lever 84 makes a vertical movement inside of the stopper case 81 by operating the operation end 841 of the operation lever 84 vertically. This movement drives the stopper member 82 to make a vertical movement through the torsion coil spring 83 so that the stopper member 82 makes an abutting contact with the front wall 811 of the stopper case 81 and makes a vertical movement in a state of being guided by the front wall 811 and the projecting part 821 of the stopper member 82 makes a movement of being inserted into or taken out from an engaging bore 815 arranged on the bottom wall 813 of the stopper case 81.
Then a relative movement of the frame 6 and the spring case 71 is restricted and a rocking movement is locked at a time when the projecting part 821 of the stopper member 82 projects downward from the engaging bore 815 of the stopper case 81 and then the projecting part 821 is inserted into a slit-shaped engaging bore 715 that locates below the engaging bore 815 and that is arranged on the movable plate part 714 of the spring case 71.
Concretely, each part acts as follows and then rocking movement is locked.
As shown in
The rocking position is locked because the relative movement between the seat frame 6 and the spring case 71 is restricted by restricting the projecting part 821 of the stopper member 82 that is restricted from moving back and forth to the seat frame 6 through the stopper case 81 is fittingly inserted into the slit-shaped engaging bore 715 of the movable plate part 714 of the spring case 71. At this time, if each size of the projecting part 821 of the stopper member 82 and the engaging bore 715 of the movable plate part 714 is set so as to be tightly fit each other in the back and forth direction, it is possible to lessen positional misalignment of the stopper member 82 and the movable plate part 714 after locked. Furthermore, in this embodiment, since the stopper member 82 is also inserted into the slit-shaped engaging bore 618 of the bottom wall 616 of the seat frame 6 simultaneously and a sharing force applied to the stopper member 82 concentrates only on the projecting part 821 locating at a distal end of the stopper member 82, it is possible to prevent deformation of the stopper member 82.
In addition, as mentioned, since the movable plate part 714 as being the rear end part of the spring case 71 is restricted from making a vertical movement relative to the seat frame 6 and the engaging bore 715 of the movable plate part 714 locates at a position vertically near the slit-shaped engaging bore 618 of the bottom wall 616 of the seat frame 6 on a constant basis, the positional misalignment is difficult to generate and it becomes easy to fittingly insert the stopper member 82 into the engaging bore 715 and the slit-shaped engaging bore 618 simultaneously. Furthermore, the movable plate part 714 as being the rear end part of the spring case 71 is restricted from making a movement also in the right and left directions relative to the seat frame 6, it is easy for the engaging bore 715 of the movable plate part 714 to keep in parallel with the slit-shaped engaging bore 618 of the seat frame 6 so that it becomes easier to insert the stopper member 82. As a result of this, it is possible to improve operationality of the stopper member 82 and also possible to lessen clearance by diminishing a dimensional difference between the projecting part 821 of the stopper member 82 and the engaging bore 715 and the slit-shaped engaging bore 618.
At a time of releasing a locked state, the operation lever 84 shown in
In addition, in this embodiment, as shown in
Specifically, as shown in
Concretely, an operation will be conducted as follows.
First, as shown in the left view of
In addition, as shown in
As shown in
The gas spring lever 22 is generally of a stick shape, and each of the operating end 221 to operate the gas spring lever 22 and a working end 222 to push the projecting and sinking member 211 is of a flat shape generally in parallel to a horizontal surface at a non-operated position. The engaging part 223 to engage the support frame 4 from downward at a position near the working end 222 from the gravity point in a longitudinal direction of the gas spring lever 22 is arranged between the operating end 221 and the working end 222 on the bottom surface of the gas spring lever 22. The engaging part 223 is a hook-shaped projecting part of an “L” character extending in the working end 222 side from the bottom surface of a body of the gas spring lever 22 toward a little further downward, and is integrally formed with the body of the gas spring lever 22.
The gas spring lever mounting part 43 comprising the mounting bore 431, as described based on
Since the gravity point of the gas spring lever 22 locates nearer the operating end 221 than the engaging part 223, the gas spring lever 22 tries to rotate around the engaging part 223 to locate the operating end 221 at the bottom side just by hooking the engaging part 223 with the mounting bore 431 of the gas spring lever mounting part 43 of the support frame 4, and then the gas spring lever 22 is stabilized at a position where the bottom surface 224 locating rearward of the engaging part 223 makes an abutting contact with the top surface of the gas spring lever mounting part 43. Then with this state kept, it becomes possible to incorporate the support rod 12 into the support frame 4 easily.
Furthermore, in this embodiment, as shown in
Concretely, as shown in
The limit angle α at which the gas spring lever 22 is mountable or dismountable is, as shown in
If the support rod 12 is dismounted as shown in
However, in case that the support rod 12 is incorporated into the support frame 4 as shown in
In addition, the mounting bore 431 of the support frame 4 is, as shown in
With this arrangement, if the operating end 221 of the gas spring lever 22 is pulled upward, the working end 222 moves downward with the engaging part 223 as the fulcrum. This movement enables the working end 222 to push the projecting and sinking member 211 of the gas spring 21 so that the height of the seat surface can be adjusted.
As mentioned, the chair of this embodiment comprises the support frame 4 supported by the support rod 12, the back frame 5 that can make an inclining movement relative to the support frame 4, the seat frame 6 that is related to the support frame 4 and the back frame 5 so as to make a movement in conjunction with the back frame 5 toward the direction in the inclining movement of the back frame 5, and the spring case 71 arranged along the seat frame 6 in a state that the proximal point part 716 is supported by the support frame 4 so as to introduce the spring force against the force of the movement of the seat frame 6 and the back frame 5 in conjunction with the support frame 4, and is so arranged that the spring 72 is compressed by the movement of the seat frame 6 relative to the spring case 71, wherein the slide guide parts 66, 67, 68 to make the spring case 71 and the seat frame 6 line-contact in the direction orthogonal to the back and forth direction are arranged between the spring case 71 and the seat frame 6.
With this arrangement, since the area of the part where the spring case 71 makes contact with the seat frame 6 is limited, it is possible to expect to reduce the sliding resistance effectively as a whole. In addition, since the spring case 71 and the seat frame 6 only make a line-contact each other in the direction orthogonal to the direction of the relative movement of the spring case 71 and the seat frame 6, even though the spring case 71 is not arranged in parallel with the seat frame 6, it is possible for the spring case 71 and the seat frame 6 to contact each other so that it does not require a higher accuracy in processing and assembling the spring case 71 and the set frame 6 compared with a case wherein the spring case 71 and the seat frame 6 make a proximal contact.
Especially, in case that the chair of this embodiment is so arranged that the proximal point part 716 of the spring case 71 is supported by the support frame 4 rotatably around the transversal shaft 44 and the base spring bearing 75 is formed on the extending part locating at the distal end side, the movable spring bearing 73 is arranged at the seat frame 6 side to face the base spring bearing 75 and the spring 72 is arranged between the base spring bearing 75 and the movable spring bearing 73, it is likely that the extending part of the spring case 71 swings in the right and left directions due to the force of the spring 72. In order to prevent this, especially the second slide guide part 67 is more effective.
In addition, also in case that the support frame 4 and the spring case 71 can be mounted and dismounted at the assembled angle at least more upright than the used angle, and the cam surface 46 is arranged for the support frame 4 to urge the movable spring bearing 73 toward the direction that the spring 72 is compressed in accordance with the movement of the spring case 71 from the assembled angle to the used angle, the sliding resistance increases because the spring case 71 is pushed against the seat frame 6 and the spring case 71 tends to be disengaged from the seat frame 6. In order to prevent this, especially the first slide guide part 66 is more effective.
In addition, if the void part 65 is formed on a part of the seat frame 6, the spring case 71 is housed in the void 65 at generally the same height as that of the seat frame 6 and the first slide guide part 66 extending in the lateral direction is integrally formed with the seat frame 6 at the position to press the top surface of the spring case 71, it is possible to make the chair compact as a whole.
Furthermore, since the first slide guide part 66 is arranged only at one position along the back and forth direction, it is possible to keep the positional relationship between the spring case 71 and the seat frame 6 appropriate even though the spring case 71 and the seat frame 6 are not arranged strictly in parallel.
In addition, as mentioned above, since the spring case 71 is housed between the right and left walls 612 of the seat frame 6, and the second slide guide part 67 extending in the longitudinal direction is arranged on either the right and left walls 612 of the seat frame 6 or the right and left walls 712 of the spring case 71, it is possible to appropriately support the distal end of the spring case 71 with less resistance in the right and left directions.
Furthermore, since the second slide guide part 67 is arranged only at one position along the back and forth direction, it is possible to keep the positional relationship between the spring case 71 and the seat frame 6 appropriately even though the spring case 71 and the seat frame 6 are not arranged strictly in parallel.
In addition, since the void part 65 opens rearward of the seat frame 6 and the spring case 71 can be mounted on and dismounted from the void part 65 of the seat frame 6 through the opening end 69, it is possible to incorporate the spring case 71 into the seat frame 6 with ease.
Furthermore, since each of the slide guide parts 66, 67, 68 is a projecting part whose distal end is curved to form a convex and is integrally formed with the seat frame 6, it is possible to form the slide guide parts 66, 67, 68 easily and appropriately.
A concrete arrangement of each part is not limited to the above-mentioned embodiment.
For example, in the above-mentioned embodiment the first slide guide part 66, the second slide guide part 67 and the third slide guide part 68 are integrally formed with the seat frame 6 as a convex part to make a line contact with the spring case 71, however, the above-mentioned shape is not indispensable as the shape of the slide guide part 66, 67, 68 as long as the seat frame 6 and the spring case 71 are allowed to make a smooth sliding movement each other while the relative position between the seat frame 6 and the spring case 71 is restricted. The slide guide parts 66, 67, 68 may be of a roller bearing shape wherein a small roller is rotatably mounted on the seat frame 6 as shown in
In addition, in the above-mentioned embodiment, the slide guide parts 66, 67, 68 are integrally formed with the seat frame 6, however, since a main function of the slide guide parts is to keep the positional relationship between the seat frame 6 and the spring case 71 appropriately and to allow a smooth sliding movement by decreasing an area where the seat frame 6 and the spring case 71 contact each other, the slide guide parts 66, 67, 68 may be arranged on the spring case 71. In this case, the same effect can be obtained.
EXPLANATION OF THE CODES
- 4 . . . support frame
- 5 . . . back frame
- 6 . . . seat frame
- 7 . . . reactive force mechanism
- 44 . . . front transversal shaft
- 45 . . . rear transversal shaft
- 46 . . . cam surface
- 52 . . . middle transversal shaft
- 53 . . . frontward facing opening concave part
- 62 . . . rotation slide bore
- 64 . . . downward facing opening concave part
- 66 . . . first slide guide part
- 67 . . . second slide guide part
- 68 . . . third slide guide part
- 71 . . . spring case
- 72 . . . compression coil spring
- 73 . . . movable spring bearing
- 74 . . . bearing member
- 75 . . . base spring bearing
Claims
1. A chair comprising a support frame supported by a support rod, a back frame that can make a inclining movement relative to the support frame, a seat frame that is related to the support frame and the back frame so as to make a movement in conjunction with the back frame toward a direction along the inclining movement of the back frame, and a spring case arranged along the seat frame in a state that a proximal point part of the spring case is supported by the support frame so as to introduce a spring force against a force of the interlocking movement of the seat frame and the back frame to the support frame, and is so arranged that a spring is compressed by a movement of the seat frame relative to the spring case, and is characterized by that
- a slide guide part to make the spring case and the seat frame line-contact in a direction orthogonal to a back and forth direction or point-contact is arranged between the spring case and the seat frame.
2. The chair described in claim 1, wherein
- the spring case is so arranged that the proximal point part is rotatably supported by the support frame around a transversal shaft and a base spring bearing is formed on an extending part locating at a distal end side, a movable spring bearing is arranged at the seat frame side to face the base spring bearing and a spring is arranged between the base spring bearing and the movable spring bearing.
3. The chair described in claim 2, wherein
- the support frame and the spring case can be mounted and dismounted at an assembled angle at least more upright than an used angle, and a cam surface is arranged for the support frame to urge the movable spring bearing toward a direction that the spring is compressed in accordance with a movement of the spring case from the assembled angle to the used angle.
4. The chair described in claim 2, wherein
- a void part is formed on a part of the seat frame, the spring case is housed in the void part at generally the same height as that of the seat frame and a first slide guide part extending in the lateral direction is integrally formed with the seat frame at a position to press the top surface of the spring case.
5. The chair described in claim 3, wherein
- a void part is formed on a part of the seat frame, the spring case is housed in the void part at generally the same height as that of the seat frame and a first slide guide part extending in the lateral direction is integrally formed with the seat frame at a position to press the top surface of the spring case.
6. The chair described in claim 4, wherein
- the first slide guide part is arranged only at one position along the back and forth direction.
7. The chair described in claim 5, wherein
- the first slide guide part is arranged only at one position along the back and forth direction.
8. The chair described in claim 2, wherein
- the spring case is housed between the right and left walls of the seat frame, and a second slide guide part extending in the vertical direction is arranged on either the right and left walls of the seat frame or the right and left walls of the spring case facing the right and left walls of the seat frame.
9. The chair described in claim 3, wherein
- the spring case is housed between the right and left walls of the seat frame, and a second slide guide part extending in the vertical direction is arranged on either the right and left walls of the seat frame or the right and left walls of the spring case facing the right and left walls of the seat frame.
10. The chair described in claim 4, wherein
- the spring case is housed between the right and left walls of the seat frame, and a second slide guide part extending in the vertical direction is arranged on either the right and left walls of the seat frame or the right and left walls of the spring case facing the right and left walls of the seat frame.
11. The chair described in claim 5, wherein
- the spring case is housed between the right and left walls of the seat frame, and a second slide guide part extending in the vertical direction is arranged on either the right and left walls of the seat frame or the right and left walls of the spring case facing the right and left walls of the seat frame.
12. The chair described in claim 6, wherein
- the spring case is housed between the right and left walls of the seat frame, and a second slide guide part extending in the vertical direction is arranged on either the right and left walls of the seat frame or the right and left walls of the spring case facing the right and left walls of the seat frame.
13. The chair described in claim 7, wherein
- the spring case is housed between the right and left walls of the seat frame, and a second slide guide part extending in the vertical direction is arranged on either the right and left walls of the seat frame or the right and left walls of the spring case facing the right and left walls of the seat frame.
14. The chair described in claim 8, wherein
- the second slide guide part is arranged only at one position along the back and forth direction.
15. The chair described in either of claim 4, wherein
- the void part opens rearward of the seat frame and the spring case can be mounted on and dismounted from the void part of the seat frame from the rearward.
16. The chair described in claim 1, wherein
- the slide guide part is a projecting part whose distal end is curved to form a convex and is integrally formed with the spring case or the seat frame.
Type: Application
Filed: Mar 11, 2011
Publication Date: Jun 28, 2012
Applicant: KOKUYO CO., LTD. (Osaka)
Inventor: Katsuaki Hayashi (Osaka)
Application Number: 13/046,078
International Classification: A47C 3/00 (20060101);