Patent Application
20250176720
The present invention relates to a chair.
Priority is claimed on Japanese Patent Application No. 2022-038415, filed Mar. 11, 2022, the content of which is incorporated herein by reference.
In the related art, as a chair used for office work or the like, there is known a chair that includes a backrest that is supported on a support structure that supports the backrest or a seat so that it can be rotated around an axis in a widthwise direction of the chair. Such a chair includes a regulating part configured to regulate the above-mentioned rotation of the backrest, a biasing part configured to store a force that returns the backrest rotated around the axis to an initial state, and an adjustment portion configured to adjust the biasing part (for example, see Patent Document 1).
Patent Document 1: Japanese Patent No. 4848099
In the chair disclosed in Patent Document 1, an operating lever configured to operate the regulating part and a knob of the adjustment portion are disposed at positions separated in a forward/rearward direction. For this reason, when an operation of the regulating part and an operation of the adjustment portion are continuously performed, a seated person needs to change posture, and operability is poor. In addition, during assembly, the operating lever for operating the regulating part and the knob of the adjustment portion cannot be assembled together, making it difficult to unitize them and resulting in poor workability during assembly.
Here, the present invention is directed to providing a chair having good operability and workability upon assembly.
In order to achieve the aforementioned objects, a chair according to an aspect of the present invention has a support structure; a backrest that is supported rotatably with respect to the support structure around a first axis extending in a widthwise direction of the support structure and that is displaceable to an inclined state tilted rearward from an initial state; a regulating part configured to regulate rotation of the backrest around the first axis; a return part configured to return the backrest in the inclined state to the initial state; a first operation member configured to allow a seated person to operate the regulating part; a second operation member configured to allow the seated person to operate the return part; and a base member configured to support the first operation member and the second operation member, the base member extends in the widthwise direction, the first operation member is supported by a first support part provided on one end side of the base member in the widthwise direction, and the second operation member is supported by a second support part provided on other end side of the base member in the widthwise direction.
In the aspect of the present invention, the first operation member is supported on one side of the base member in the widthwise direction, and the second operation member is supported on the other side of the base member in the widthwise direction. Accordingly, the seated person can operate the regulating part with one hand in the widthwise direction while sitting, and operate the return part with the other hand in the widthwise direction without changing a posture, which provides good operability. In addition, it is possible to prevent interference between the first operation member and the second operation member. Further, since the first operation member and the second operation member can be integrated via the base member, they can be easily unitized and workability during assembly is good.
In addition, in the chair according to the aspect of the present invention, the base member may have a rod shape extending in the widthwise direction.
According to this configuration, a space occupied by the base member can be reduced, and it is possible to secure a wider space for disposing other members such as the regulating part, the return part, and the like.
In addition, in the chair according to the aspect of the present invention, the base member may be a shaft portion having a second axis extending in the widthwise direction, and the first operation member and the second operation member may be coaxially disposed on the second axis.
According to this configuration, since the base member, the first operation member and the second operation member are arranged in the widthwise direction, a space occupied by these members can be reduced.
In addition, in the chair according to the aspect of the present invention, the return part may have a spring configured to bias the backrest in the inclined state in a direction of returning to the initial state; and an adjustment portion that is linked to the second operation member and that is configured to adjust a biasing force of the spring, the base member may be rotatable around the second axis, the first operation member may be rotatable around the second axis relative to the base member, and the second operation member may be fixed to the base member not to be rotatable around the second axis relative to the base member.
According to this configuration, the operating force of the second operation member can be directly transmitted to the spring.
In addition, in the chair according to the aspect of the present invention, the regulating part and the return part may be disposed with the base member sandwiched therebetween when seen in the widthwise direction.
According to this configuration, the regulating part and the return part can be positioned so that they do not interfere with each other.
In addition, in the chair according to the aspect of the present invention, the backrest may have two sidewalls disposed at an interval in the widthwise direction, the first operation member may be supported by the sidewall disposed on one side in the widthwise direction, and the second operation member may be supported by the sidewall disposed on the other side in the widthwise direction.
According to this configuration, since the first operation member and the second operation member are distributed in the widthwise direction, compared to the case in which both the first operation member and the second operation member are disposed on any one side in the widthwise direction, it is possible to prevent a seated person from mistakenly operating the first operation member and the second operation member.
In addition, in the chair according to the aspect of the present invention, the base member may have an intermediate portion between the first support part and the second support part, and both end portions of the intermediate portion in the widthwise direction may be supported by two flange portions provided on the chair.
According to this configuration, the base member can be reliably supported by the chair, and the first operation member and the second operation member can be operated in a stable state.
According to the present invention, it is possible to provide a chair having good operability and workability upon assembly.
Hereinafter, a chair according to an embodiment of the present invention will be described with reference to
In the following description, for convenience of explanation, a direction in which a seated person sitting in a regular posture on a seat 17 (described below) faces forward is referred to as “forward” and the opposite direction is referred to as “rearward.” In addition, directions of upward, downward, leftward and rightward in the following description mean directions that coincide with directions from the perspective of the seated person when the seated person sits on the seat 17 in a regular posture. A side where leg parts 10 (described below) are located is referred to as a lower side of the chair, a side where a backrest 20 (described below) is located is referred to as an upper side of the chair, a right side of the seated person sitting on the seat 17 in a regular posture is referred to as a right side of the chair, and a left side of the seated person is referred to as a left side of the chair. In the following description, a leftward/rightward direction at this time is also referred to as a widthwise direction. Further, in appropriate places in the drawings, an arrow FR indicates the forward direction, an arrow UP indicates the upward direction, and an arrow LH indicates the leftward direction.
As shown in
The leg parts 10 have multi-pronged legs 11 equipped with casters 11a, and a leg pillar 12 in which a gas spring (not shown) that is a lifting mechanism standing up from a central portion of the multi-pronged legs 11 is installed. The leg pillar 12 has an outer tube 13 and an inner tube 14. The outer tube 13 is supported by the multi-pronged legs 11 in a non-rotatable manner. A lower portion of the inner tube 14 is rotatably supported in the outer tube 13 in a horizontal direction (rotatable around a shaft that extends vertically). An upper portion of the inner tube 14 is fixed to the support base 40. A height adjustment mechanism of the leg pillar 12 and a tilting mechanism of the backrest 20 are installed in the support base 40.
The backrest 20 has a backrest structure 20A (see
The backrest support body 21 supports the back of the seated person. The backrest support body 21 has a backrest support member 30, and a rear extension member 22.
As shown in
The outer member 32 has an outer upward/downward extension part 35, and an outer upward extension part 36. The outer upward/downward extension part 35 has an outer curved upper portion 351, an outer curved lower portion 352, and an outer lower portion 353. The inner member 31 and the outer member 32 are connected by a screw.
A pivoting member 38 fixed to the inner member 31 and the outer member 32 and pivotable via a pivoting shaft 42 extending in an axial direction along a widthwise direction (leftward/rightward direction) at a rear portion of the support base 40 is provided on the backrest support member 30. An axis 42a of the pivoting shaft 42 corresponds to a first axis of the present invention. As shown in
As shown in
As shown in
As shown in
The seat supporting member 50 includes the above-mentioned seat shell 51, a main body portion 52 having a rectangular shape when seen in a plan view and configured to attach the seat shell 51 to an upper edge, a rear attachment portion 53 extending obliquely downward and rearward from a rear end portion 52a of the main body portion 52, two slots 54 extending in the forward/rearward direction on both sides of a front lower surface 52b of the main body portion 52 in the leftward/rightward direction, and a spring front end receiving portion 55 fixed to a front portion of the main body portion 52. The seat supporting member 50 is a strengthening member made of a metal material such as drawn sheet metal, aluminum die-cast, or the like, and has a receiver shape that is open upward in the upward/downward direction.
The seat supporting member 50 has a bottom wall portion 501, and a sidewall portion 502 standing up from a circumferential portion of the bottom wall portion 501. The above-mentioned seat shell 51 is attached to an upper end portion of the sidewall portion 502. A concave portion 503 that is recessed upward is formed in the bottom wall portion 501 in a shape along an external form of the compression coil spring 61 not to interfere with a compression coil spring 61, which will be described below.
The rear attachment portion 53 is provided on the pivoting member 38 of the backrest support member 30, and is rotatably connected to a secondary shaft 39 of an operating part 80 (a second operation member) extending in the leftward/rightward direction, which will be described below. The rear attachment portion 53 (i.e., the seat supporting member 50) is pivotable about the secondary shaft 39 relative to the pivoting member 38. That is, the seat supporting member 50 moves rearward with respect to the support base 40 when the backrest 20 moves from the initial state to the inclined state.
As shown in
As shown in
The fixing portions 551 are provided at positions that do not interfere with the compression coil spring 61, which is supported by the front spring reaction force receiving shaft 553 and will be described below.
The front spring reaction force receiving shaft 553 is a rod member with a circular cross section. The front spring reaction force receiving shaft 553 has both ends in the axial direction that are inserted and fixed into the through-holes 551a of the fixing portions 551, and is provided not to move in the leftward/rightward direction relative to the two fixing portions 551. Front end portions of the two compression coil springs 61 biased in a compression direction from behind are supported by the front spring reaction force receiving shaft 553.
The support base 40 includes a support base main body portion 41 fixed to an upper portion of the leg pillar 12 (see
The support base main body portion 41 has a bottom plate 411 and side plates 412 extending upward from both left and right sides of the bottom plate 411, and the support base main body portion 41 is formed in a bowl shape that opens upward as a whole. The two compression coil springs 61 are accommodated in a first internal space S1 above the support base main body portion 41. As shown in
As shown in
The slide engaging portion 43 is provided while protruding above front upper ends 412b of the side plates 412 on both left and right sides of the support base main body portion 41. The slide engaging portion 43 has a protrusion 431, and a sliding portion 432 provided on an upper end of the protrusion 431 and having a diameter greater than that of the protrusion 431. The protrusion 431 is formed in a circular cross-section that forms a diameter dimension substantially equal to a width dimension of the slots 54 (see
As shown in
The return part 92 has a biasing part 60 having the compression coil spring 61 (spring) configured to bias the backrest 20 in the inclined state in a direction in which it returns to the initial state, an adjustment portion 70 configured to adjust a biasing force of the compression coil spring 61, and the operating part 80 connected to the adjustment portion 70 and configured to operate the adjustment portion 70.
The pivoting member 38 has a rear wall 381, and two sidewalls 382a and 382b extending from both left and right ends of the rear wall 381 in a perpendicular direction and separated from each other in the widthwise direction. The adjustment portion 70 and the operating part 80 are accommodated in a second internal space S2 in front of the pivoting member 38. In addition, a rear end portion of the compression coil spring 61 is supported by a front portion of the second internal space S2.
The two sidewalls 382a and 382b of the pivoting member 38 are supported by the pivoting shaft 42 to be pivotable relative to the rear upper portions 412a of the side plates 412 of the support base main body portion 41. The adjustment portion 70 and the operating part 80 are disposed in the second internal space S2 located behind the pivoting shaft 42 in the pivoting member 38. The pivoting member 38 supports the pivoting shaft 42 on the front portion. In addition, the pivoting member 38 includes the secondary shaft 39, a rear portion of which is attached to the rear attachment portion 53 (see
The secondary shaft 39 extends in the leftward/rightward direction, and is supported by the sidewalls 382a and 382b on both left and right sides. A connecting piece 532 (see
The biasing part 60 is configured to provide a returning force for returning the backrest 20, which has been tilted by the biasing force, to its original position (initial state). The biasing part 60 has the compression coil spring 61, a spring front end support part 62 provided on one end portion (front end portion) of the compression coil spring 61, and a spring rear end support part 63 provided on the other end portion (rear end portion).
The compression coil spring 61 has a front end compressed rearward, and a rear end compressed forward. The first internal space S1 of the support base main body portion 41 contains the two compression coil springs 61 arranged in the leftward/rightward direction with the biasing directions of the springs facing the forward/rearward directions. The two compression coil springs 61 are installed in a state where they are always compressed and generate a biasing force, regardless of whether the backrest 20 is in the initial state or the inclined state.
The spring front end support part 62 and the spring rear end support part 63 are connected by a telescopic joint shaft 64 inserted through the inside of the compression coil spring 61. In the biasing part 60, the telescopic joint shaft 64 extends and contracts due to a change in distance between the spring front end support part 62 and the spring rear end support part 63 depending on compression and elongation of the compression coil spring 61.
The spring front end support part 62 abuts the front end of the compression coil spring 61 from the front. The spring front end support part 62 is formed in a U shape that opens forward when seen in the leftward/rightward direction. A concave portion 62a (see
The spring rear end support part 63 abuts the rear end of the compression coil spring 61 from behind. The spring rear end support part 63 has a through-hole 631 (see
The spring rear end support part 63 is in a state where a spring force is applied from the front to the working shaft 71. That is, the working shaft 71 receives the reaction force from the compression coil spring 61 regardless of whether the backrest 20 is in the initial state or the inclined state.
The adjustment portion 70 has a function of adjusting a biasing force of the compression coil spring 61 of the biasing part 60 and adjusting a returning force of the backrest 20 in the inclined state. The adjustment portion 70 is accommodated in the second internal space S2 between the sidewalls 382a and 382b of the pivoting member 38 of the backrest 20.
The adjustment portion 70 includes the working shaft 71 operated by a biasing force of the biasing part 60 (the compression coil spring 61), an adjusting shaft 72 configured to movably support the working shaft 71, and a support member 73 configured to rotatably support the adjusting shaft 72 with respect to the operating part 80.
The adjusting shaft 72 is integrated with a second transmission gear 721 having a bevel gear on an upper end thereof. The second transmission gear 721 meshes with a first transmission gear 83 of the operating part 80 described below, and by operating the operating shaft 81 of the operating part 80, a rotational force is transmitted from the first transmission gear 83 to the second transmission gear 721, and the adjusting shaft 72 rotates in both forward and reverse directions. The adjusting shaft 72 has a male thread formed thereon over the entire axial direction, into which the working shaft 71 screws. The adjustment portion 70 is coordinated with the operation of the operating part 80.
In the initial state, the adjusting shaft 72 is arranged with the axial direction angled diagonally from front to rear as it moves from a shaft lower end portion 72b to a shaft upper end portion 72a when seen in a side view. The shaft lower end portion 72b is located below the pivoting shaft 42. The shaft upper end portion 72a is located above and behind the pivoting shaft 42. That is, the working shaft 71 that moves along the adjusting shaft 72, i.e., the spring rear end support part 63 provided on the rear end of the compression coil spring 61 connected to the working shaft 71 is configured to move between a position below the pivoting shaft 42 and a position above and behind the pivoting shaft 42.
In the adjustment portion 70, as the adjusting shaft 72 rotates, the working shaft 71 that screws onto the male thread moves in the axial direction of the adjusting shaft 72 according to the rotation position of the adjusting shaft 72. That is, in the adjustment portion 70, as the working shaft 71 moves along the adjusting shaft 72, the position of the working shaft 71 can be adjusted. When the working shaft 71 moves on the adjusting shaft 72, since the compression coil spring 61 rotates around the spring front end support part 62, only the angle seen from the leftward/rightward direction changes.
The support member 73 has a fixing plate 731 extending in the upward/downward direction and fixed to the rear wall 381 of the pivoting member 38 by a screw (not shown), an upper support plate 732 and a lower support plate 733 extending forward from upper and lower ends of the fixing plate 731, and two side support plates 734 and 735 (two flange portions) extending upward from both sides of the upper support plate 732 in the leftward/rightward direction. The left side support plate 734 in the two side support plates 734 and 735 is expressed as a first side support plate 34, and the right side support plate 735 is expressed as a second side support plate 735. The adjusting shaft 72 is disposed between the upper support plate 732 and the lower support plate 733. The adjusting shaft 72 has the shaft upper end portion 72a rotatably supported by the upper support plate 732, and the shaft lower end portion 72b rotatably supported by the lower support plate 733.
As shown in
As shown in
The operating shaft 81 is rotatably supported by the right sidewall 382a of the pivoting member 38. The hole portion 382c through which the operating shaft 81 is inserted is formed in the right sidewall 382a on the side of the upper portion. The operating shaft 81 is disposed above the adjusting shaft 72, and disposed such that an axial center of the operating shaft 81 and an axial center of the adjusting shaft 72 are located in the same plane. The operating shaft 81 is supported by a base member 91 supported on the support member 73. The support member 73 and the base member 91 will be described below.
The first transmission gear 83 provided in an intermediate portion of the operating shaft 81 in the axial direction is meshed with the second transmission gear 721 provided on the adjusting shaft 72. That is, in rotation of the operating shaft 81, i.e., rotation around an axial center of the first transmission gear 83 in the leftward/rightward direction, a rotation direction is converted into rotation around the axial center of the adjusting shaft 72 of the second transmission gear 721.
In the chair 1 configured in this way, when the reaction force (returning force) of the backrest 20 is adjusted, first, if the operating lever 82 of the operating part 80 is rotated, the working shaft 71 located at a position of the spring rear end support part 63 of the compression coil spring 61 is vertically moved along the adjusting shaft 72. For example, as the operating lever 82 is rotated in one direction, the adjusting shaft 72 is rotated in one direction via the first transmission gear 83 and the second transmission gear 721, and the nut portion 711 that screws into the adjusting shaft 72, i.e., the working shaft 71 moves upward along the adjusting shaft 72.
In this way, as the working shaft 71 moves on the adjusting shaft 72, a distance between the spring front end support part 62 and the spring rear end support part 63 of the biasing part 60 is changed, and thus, a compression amount of the compression coil spring 61, i.e., a biasing force (reaction force) of the compression coil spring 61 can be adjusted. That is, the returning force when the backrest 20 returns from the inclined state to the initial state can be adjusted.
Further, in the adjustment portion 70 of the embodiment, as the working shaft 71 moves on the adjusting shaft 72, a position of the working shaft 71, i.e., a position of the spring rear end support part 63 of the compression coil spring 61 can be changed to adjust a biasing force of the compression coil spring 61 (a returning force of the backrest 20). Then, in the embodiment, as shown in
As shown in
The base member 91 is inserted through the first hole portion 734a and the second hole portion 735a. The base member 91 supports the operating part 80 (second operation member) of the return part 92 and an operation member 95 (first operation member) of the regulating part 93, which will be described below.
As shown in
An intermediate portion of the base member 91 in the lengthwise direction (leftward/rightward direction) is expressed as an intermediate portion 911, a left side of the intermediate portion 911 is expressed as a first support part 912, and a right side of the intermediate portion 911 is expressed as a second support part 913.
A cross-sectional shape of the intermediate portion 911 is a circular shape. A cross-sectional shape of the first support part 912 is a circular shape smaller than the cross-sectional shape of the intermediate portion 911. At a boundary between the intermediate portion 911 and the first support part 912, a first stepped portion 914 is formed, where the outer circumference of the intermediate portion 911 protrudes in the radial direction more than the outer circumference of the first support part 912. An end surface 911b of the intermediate portion 911 on the right side (the side of the first support part 912) and a circumferential surface of the first support part 912 form the first stepped portion 914.
A cross-sectional shape of the second support part 913 is a rectangle, corners of which are rounded. The rectangular cross-sectional shape of the second support part 913 has a size inscribed in the circular cross-sectional shape of the intermediate portion 911. For this reason, at the boundary between the intermediate portion 911 and the second support part 913, a second stepped portion 915 is formed, where the outer circumference of the intermediate portion 911 protrudes further outward in the radial direction than the outer circumference of the second support part 913. An end surface 911c of the intermediate portion 911 on the left side (the side of the second support part 913) and a circumferential surface of the second support part 913 form the second stepped portion 915.
A left end portion 911a of the intermediate portion 911 in the base member 91 is inserted into the hole portion 734a of the first side support plate 734. A left end surface 911b of the intermediate portion 911 slightly protrudes leftward from a left surface 734b of the first side support plate 734. That is, a right end surface 911b of the intermediate portion 911 is located on slightly a left side of the left surface 734b of the first side support plate 734.
The first hole portion 734a is a round hole. An inner diameter of the first hole portion 734a is equal to or slightly greater than an external form of the intermediate portion 911. The intermediate portion 911 inserted into the first hole portion 734a is rotatable about the axis 91a of the base member 91 relative to the first side support plate 734. The first support part 912 is disposed on a left side of the first side support plate 734.
A portion of the base member 91 on a slightly right side of a left end portion 913a of the second support part 913 is inserted into the second hole portion 735a of the second side support plate 735. A boundary between the second support part 913 and the intermediate portion 911 is disposed on a left side of the second side support plate 735, i.e., on the side of the first side support plate 734. The second hole portion 735a is a round hole. An inner diameter of the second hole portion 735a is greater than an outer diameter of the second support part 913. The second support part 913 inserted into the second hole portion 735a is rotatable around the axis 91a of the base member 91 relative to the second side support plate 735.
The base member 91 is rotatable around the axis 91a of the base member 91 relative to the support member 73 while being inserted into the first hole portion 734a of the first side support plate 734 and the second hole portion 735a of the second side support plate 735.
A first concave portion 736 and a second concave portion 737 are formed in the upper edge portion of the first side support plate 734 in parallel in the circumferential direction (a direction around the axis 91a of the base member 91). The first concave portion 736 is disposed in front of the second concave portion 737. A convex portion 738 is formed between the first concave portion 736 and the second concave portion 737. A convex portion of a connecting member 94, which will be described below, is configured to enter the first concave portion 736 and the second concave portion 737.
As shown in
The operating shaft 81 is inserted through the hole portion 382c of the right sidewall 382a of the pivoting member 38 from the right side. An outer diameter of the left end portion 81a of the operating shaft 81 is smaller than a diameter of the hole portion 382c. The operating shaft 81 has an expanded diameter portion 812 formed at a position on a right side of the left end portion 81a and protruding in the radial direction. An outer diameter of the expanded diameter portion 812 is greater than a diameter of the hole portion 382c. The expanded diameter portion 812 regulates leftward displacement of the operating shaft 81 when coming in contact with a right surface of a sidewall 382a in a state in which the operating shaft 81 is inserted through the hole portion 382c.
A groove portion 813 is formed in the operating shaft 81 at a position on a right side of the left end portion 81a and a position on a left side of the expanded diameter portion 812 throughout the circumferential direction. A bearing member 814 is fitted into the groove portion 813. The bearing member 814 is a C-shaped member formed by removing a part of the annular member, and can be fitted into the groove portion 813 of the operating shaft 81 from the outer circumferential side of the operating shaft 81. In the embodiment, the bearing member 814 can be fitted into the groove portion 813 of the operating shaft 81 from above. The bearing member 814 has a flange 814a protruding outward from a right end portion in the radial direction.
The bearing member 814 is fitted into the groove portion 813 of the operating shaft 81 in a state in which the operating shaft 81 is inserted through the hole portion 382c of the right sidewall 382a of the pivoting member 38 from the right side and the expanded diameter portion 812 comes into contact with or is spaced apart a small gap from a right surface of the sidewall 382a. In the embodiment, the right surface of sidewall 382a has a rib that protrudes rightward from an edge portion of the hole portion 382c, and the expanded diameter portion 812 comes into contact with or spaced apart a small gap from the rib. When the bearing member 814 is fitted into the groove portion 813 in this way, the flange 814a is disposed in contact with or spaced apart a small gap from a left surface of the sidewall 382a. The bearing member 814 regulates rightward displacement of the operating shaft 81 when coming into contact with the left surface of the sidewall 382a.
Further, even when at least one of the expanded diameter portion 812 and the bearing member 814 comes into contact with the sidewall 382a, the operating shaft 81 is rotatable around the axis relative to the sidewall 382a.
The operating part 80 regulates displacement with respect to the pivoting member 38 in the leftward/rightward direction by the expanded diameter portion 812 and the flange 814a of the operating shaft 81.
As shown in
The base member 91 is inserted through the hole portion 833 of the first transmission gear 83. A portion in the second support part 913 of the base member 91 on the left side of the second side support plate 735 is fitted into the first hole portion 833a. A cross-sectional shape of the first hole portion 833a is the same rectangle with rounded corners as the cross-sectional shape of the second support part 913. A right end portion of the intermediate portion 911 of the base member 91 is fitted into the second hole portion 833b. A cross-sectional shape of the second hole portion 833b is the same circle as the cross-sectional shape of the intermediate portion 911.
The second support part 913 of the base member 91 is inserted through the hole portion 833 of the first transmission gear 83. The first transmission gear 83 and the base member 91 are fixed not to relatively rotate around the axis 91a of the base member 91. The first transmission gear 83 has an end portion on the left side (on the side of the intermediate portion 911) of the second support part 913 inserted therethrough. As shown in
When the operating shaft 81 rotates around the axis 91a of the base member 91, the base member 91 also rotates integrally. When the base member 91 rotates around the axis 91a of the base member 91, it rotates integrally with the first transmission gear 83. That is, when the operating shaft 81 rotates around the axis 91a of the base member 91, the first transmission gear 83 also rotates integrally.
Since the base member 91 is rotatable around the axis 91a of the base member 91 relative to the support member 73, the support member 73 does not rotate even when the base member 91 rotates.
As described above, the regulating part 93 shown in
As shown in
The operating shaft 951 is rotatably supported by the left sidewall 382b of the pivoting member 38. The hole portion 382d through which the operating shaft 951 is inserted is formed on an upper side of the left sidewall 382b.
The operating shaft 951 has a concave portion 953 formed in a right end portion 951a and extending in the leftward/rightward direction to open rightward. The first support part 912 of the base member 91 is inserted into the concave portion 953. A right end surface 951b of the operating shaft 951 is adjacent to the end surface 911b on the right side (the side of the first support part 912) of the intermediate portion 911 of the base member 91 with a small gap. Accordingly, when the base member 91 is to be displaced leftward relative to the operating shaft 951, i.e., the operation member 95, the right end surface 911b of the intermediate portion 911 of the base member 91 abuts the right end surface 951b of the operating shaft 951, and the displacement is regulated. Leftward displacement of the base member 91 with respect to the operation member 95 is regulated.
As described above, the right end surface 911b of the intermediate portion 911 is located slightly to the left of the left surface 734b of the first side support plate 734. For this reason, a small gap is formed between the right end surface 951b of the operating shaft 951 and the right end surface 911b of the intermediate portion 911.
A cross-sectional shape of the concave portion 953 is a circular shape equal to or slightly greater than the cross-sectional shape of the first support part 912. The relative rotation of the operating shaft 951 and the first support part 912 around the axis 91a of the base member 91 is not constrained. That is, the operating shaft 951 is rotatably supported by the base member 91 around the axis 91a of the base member 91.
A cross-sectional shape (external form) of the right end portion 951a of the operating shaft 951 formed with the concave portion 953 is a rectangle with rounded corners. A cross-sectional shape of a portion 951c of the operating shaft 951 on the left side of the right end portion 951a is a circular shape. A rectangular cross-sectional shape of the operating shaft 951 on the right side of the operating shaft 951 has a size inscribed in a circle of the cross-sectional shape of the portion 951c on the left side.
As shown in
A ridge 954 extending in the leftward/rightward direction is formed on the outer circumferential portion of the right end portion 951a of the operating shaft 951.
The operating shaft 951 is inserted through the hole portion 382d of the left sidewall 382b of the pivoting member 38 from the left side. An outer diameter of the right end portion 951a of the operating shaft 951 is smaller than a diameter of the hole portion 382d. An expanded diameter portion 955 protruding in the radial direction is formed on the operating shaft 951 at a position on the left side of the right end portion 951a. An outer diameter of the expanded diameter portion 955 is greater than a diameter of the hole portion 382d. The expanded diameter portion 955 regulates rightward displacement of the operating shaft 951 when coming into contact with a left surface of a sidewall 382b in a state in which the operating shaft 951 is inserted through the hole portion 382d.
A groove portion 956 is formed in the operating shaft 951 at a position on the left side of the right end portion 951a and a position on the right side of the expanded diameter portion 955 throughout in the circumferential direction. A bearing member 957 (see
The bearing member 957 is fitted into the groove portion 956 of the operating shaft 951 in a state in which the operating shaft 951 is inserted through the hole portion 382d of the left sidewall 382b of the pivoting member 38 from the left side and the expanded diameter portion 955 comes into contact with or is spaced apart a small gap from the left surface of the sidewall 382b. In the embodiment, a rib protruding rightward from an edge portion of the hole portion 382d is provided on the left surface of the sidewall 382b, and the expanded diameter portion 955 is disposed in contact with or spaced apart a small gap from the rib. When the bearing member 957 is fitted into the groove portion 956 in this way, the flange 957a is disposed in contact with or spaced apart a small gap from the right surface of the sidewall 382b. The bearing member 957 regulates leftward displacement of the operating shaft 951 when coming into contact with the right surface of the sidewall 382b.
Further, even when at least one of the expanded diameter portion 955 and the bearing member 957 comes into contact with the sidewall 382b, the operating shaft 951 is rotatable about the axis relative to the sidewall 382b.
Displacement of the operation member 95 in the leftward/rightward direction with respect to the pivoting member 38 is regulated by the expanded diameter portion 955 and the flange 957a of the operating shaft 951.
As shown in
The first connecting portion 941 is cylindrical and has a hole portion 941a disposed therethrough in the widthwise direction. A cross-sectional shape of the hole portion 941a of the first connecting portion 941 is the same rectangle with rounded corners as the external form of the right end portion of the operating shaft 951. A groove portion 941b corresponding to the ridge 954 of the operating shaft 951 is formed in an inner circumferential surface of the hole portion 941a. The right end portion 951a of the operating shaft 951 is fitted into the hole portion 941a of the first connecting portion 941. The ridge 954 of the operating shaft 951 is inserted into the groove portion 941b of the hole portion 941a of the first connecting portion 941. The operating shaft 951 and the first connecting portion 941 do not rotate relative to each other. That is, the connecting member 94 is fixed to the operating shaft 951 and does not rotate around the axis 91a of the base member 91 relative to the operating shaft 951. The first support part 912 of the base member 91 is inserted through the hole portion 941a of the first connecting portion 941. The first connecting portion 941 is rotatable around the axis 91a of the base member 91 relative to the base member 91.
A left end surface 941c of the first connecting portion 941 is disposed at a position of the third stepped portion 951d (see also
The second connecting portion 942 is cylindrical and has a hole portion 942a disposed in a direction passing in the widthwise direction. A cross-sectional shape of the hole portion 942a of the second connecting portion 942 is the same as or slightly greater than the circular cross-sectional shape of the intermediate portion 911 of the base member 91. The intermediate portion 911 is inserted into the hole portion 942a of the second connecting portion 942. The second connecting portion 942 is rotatable around the axis 91a of the base member 91 relative to the base member 91.
The first transmission gear 83 is disposed on the right side of the second connecting portion 942, i.e., the right side of the connecting member 94. As described above, the first transmission gear 83 is fixed to the base member 91. If the connecting member 94 is displaced rightward relative to the base member 91, it will come into contact with the first transmission gear 83, so rightward displacement is regulated. Further, a small gap is provided between the right end surface of the connecting member 94 and the left end surface 83a of the first transmission gear 83 to allow relative rotation between the connecting member 94 and the base member 91.
The third connecting portion 943 is rotatable around the axis 91a of the base member 91 relative to the base member 91. The third connecting portion 943 has a first plate portion 943a disposed on the left side of the first side support plate 734 and connected to the first connecting portion 941, a second plate portion 943b disposed on the right side of the first side support plate 734 and connected to the second connecting portion 942, and a connecting portion 943c configured to connect the first plate portion 943a and the second plate portion 943b.
The connecting portion 943c is disposed above the first side support plate 734. A convex portion 943d protruding downward is formed on a lower surface of the connecting portion 943c (a surface on a side facing the first side support plate 734).
As shown in
When the operation member 95 is operated to rotate around the axis 91a of the base member 91, the connecting member 94 rotates integrally with the operation member 95. The rotation of the operation member 95 stops at either the position where the convex portion 943d of the connecting member 94 is fitted into the first concave portion 736 or the position where it is fitted into the second concave portion 737.
The engaging member 96 shown in
As shown in
The shaft portion 962 is supported by the pivoting member 38. That is, the shaft portion 962 is supported by the backrest 20. The shaft portion 962 is located below the axis 91a of the base member 91 and above the engaging concave portions 44. An upper portion of the engaging member 96 is curved forward. A base support part 965 connected to the second connecting portion 942 of the connecting member 94 is provided on the upper end portion of the engaging member 96 via a link part 963. The engaging convex portion 961 is provided on the lower end portion of the engaging member 96.
The link part 963 protrudes from an outer circumferential surface of the second connecting portion 942 in the radial direction. The link part 963 protrudes from the operation member 95 in the radial direction (a direction crossing the second shaft portion). The link part 963 has a link shaft portion 963a at a tip portion thereof. The link shaft portion 963a is columnar, and an axis thereof extends in the leftward/rightward direction. The link shaft portion 963a is inserted into the base support part 965 of the upper end portion of the engaging member 96 in the leftward/rightward direction. The base support part 965 and the link shaft portion 963a are relatively rotatable around the axis of the link shaft portion 963a.
The link part 963 rotates around the axis 91a of the base member 91 together with the connecting member 94 by operating the operation member 95. The base support part 965 (the engaging member 96) rotates around the axis 91a of the base member 91 together with the link shaft portion 963a. Since the engaging member 96 is rotatably supported by the shaft portion 962, the base support part 965 rotates together with the link shaft portion 963a about the axis 91a of the base member 91, while rotating relatively to the link shaft portion 963a about the axis thereof.
The link part 963 functions as an interlocking part configured to transmit an operating force input to the operation member 95 to the engaging member 96 and interlock the engaging member 96 to the operation member 95.
As shown in
A state in which the convex portion 943d of the connecting member 94 is fitted into the first concave portion 736 and the engaging convex portion 961 is inserted into the engaging concave portions 44 is expressed as a locked state, and a state in which the convex portion 943d of the connecting member 94 is fitted into the second concave portion 737 and the engaging convex portion 961 is removed from the engaging concave portions 44 is expressed as a separated state.
The engaging convex portion 961 is inserted into a hole portion 383 provided in the rear wall 381 of the pivoting member 38. The engaging convex portion 961 never extends beyond the hole portion 383, but is always inserted into the hole portion 383. The hole portion 383 is located in front of and above the engaging concave portions 44. The engaging convex portion 961 is inserted into the engaging concave portions 44 when the rear side protrudes rearward from the hole portion 383 (shown by a solid line in
When a load is applied to the backrest 20 and the pivoting member 38 is displaced, the engaging convex portion 961 displaces in conjunction with this displacement, or an external force acts in the direction in which the pivoting member 38 is displaced.
When the operation member 95 is operated to change the state from the separated state to the locked state, the convex portion 943d of the connecting member 94 moves from the second concave portion 737 to the first concave portion 736. Here, the upper side of the engaging member 96 further than the shaft portion 962 moves forward and becomes a state as shown by the solid lines in
In this state, when the backrest 20 rotates around the axis 42a of the pivoting shaft 42 and the engaging concave portions 44 and the hole portion 383 overlap, the engaging convex portion 961 is inserted into the engaging concave portions 44 and enters a locked state. Here, the elastic deformation of the engaging member 96 is restored and the biasing force is reduced or eliminated.
In the locked state, when the axis of the hole portion 383 and the axis of the engaging concave portions 44 are misaligned, and the external force received from the side surface of the hole portion 383 (the pivoting member 38) and the external force received from the side surface of the engaging concave portions 44 (the support base 40) are in opposite directions, and a shearing force acts on the engaging convex portion 961 as if it is sandwiched between the side surface of the hole portion 383 and the side surface of the engaging concave portions 44, the engaging convex portion 961 becomes unable to come out of the engaging concave portions 44 even if the upper portion of the engaging member 96 moves forward.
When the operation member 95 is operated to be shifted from the locked state to the separated state, the convex portion 943d of the connecting member 94 moves from the first concave portion 736 to the second concave portion 737. Here, the upper side of the engaging member 96 relative to the shaft portion 962 moves rearward, as shown by the two-dotted chain line in
In this state, when the backrest 20 moves so that the engaging concave portions 44 and the hole portion 383 overlap, the engaging convex portion 961 comes out of the engaging concave portions 44 and enters a separated state. Here, the elastic deformation of the engaging member 96 is restored and the biasing force is reduced or eliminated.
As described above, leftward/rightward displacement of the operating part 80 with respect to the pivoting member 38 is regulated. Leftward/rightward displacement of the operation member 95 with respect to the pivoting member 38 is regulated. Rightward displacement of the base member 91 with respect to the operating part 80 is regulated. Leftward displacement of the base member 91 with respect to the operation member 95 is regulated. Leftward displacement of the connecting member 94 with respect to the operating shaft 951 is regulated. Rightward displacement of the connecting member 94 with respect to the base member 91 is regulated.
With the above-mentioned configuration, the engaging member 96 connected to the connecting member 94 regulates displacement in the leftward/rightward direction relative to the pivoting member 38. That is, the above-mentioned configuration functions as a position alignment mechanism in the leftward/rightward direction between the engaging convex portion 961 of the engaging member 96 and the engaging concave portions 44 provided on the pivoting member 38.
Next, effects of the above-mentioned chair will be described with reference to the accompanying drawings.
In the chair 1 according to the above-mentioned embodiment, the operation member 95 (first operation member) of the regulating part 93 is supported on the left side of the base member 91, and the operating part 80 (second operation member) of the return part 92 is supported on the right side of the base member 91. Accordingly, a seated person can operate the regulating part 93 with his/her left hand while sitting, and operate the return part 92 with his/her right hand without changing his/her posture, which provides good operability. In particular, since the operating member 95 and the operating part 80 are provided on the backrest 20, the seated person can operate the backrest 20 from a position close to the backrest 20.
In addition, interference between the operation member 95 and the operating part 80 can be prevented. Further, since the operation member 95 and the operating part 80 can be integrated via the base member 91, they can be easily unitized, and the workability during assembly is good.
In addition, in the chair 1 according to the embodiment, the base member 91 has a rod shape extending in the widthwise direction.
With this configuration, the space occupied by the base member 91 can be reduced, and a larger space can be secured for arranging other components such as the regulating part 93, the return part 92, and the like.
In addition, in the chair 1 according to the embodiment, the base member 91 is the shaft portion having the axis 91a (second axis) extending in the widthwise direction, and the operation member 95 and the operating part 80 are coaxially disposed on the axis 91a of the base member 91.
With this configuration, since the base member 91, the operation member 95 and the operating part 80 are arranged in the widthwise direction, a space occupied by these members can be reduced.
In addition, in the chair 1 according to the embodiment, the return part 92 has the compression coil spring 61 configured to bias the backrest 20 in the inclined state in a direction of returning to the initial state, and the adjustment portion 70 linked to the operating part 80 and configured to adjust a biasing force of the compression coil spring 61. The base member 91 is rotatable around the axis 91a of the base member 91, the operation member 95 is rotatable around the axis 91a of the base member 91 relative to the base member 91, and the operating part 80 is fixed to the base member 91 to be unable to rotate relatively to the base member 91 around the axis 91a.
With this configuration, the operating force of the operating part 80 can be directly transmitted to the compression coil spring 61.
In addition, in the chair 1 according to the embodiment, the pivoting member 38 of the backrest 20 has the two sidewalls 382a and 382b disposed at a lateral interval, the operation member 95 of the regulating part 93 is supported by the left sidewall 382a, and the operating part 80 of the return part 92 is supported by the right sidewall 382b.
With this configuration, since the operation member 95 and the operating part 80 are distributed in the widthwise direction, compared to the case in which both the operation member 95 and the operating part 80 are disposed on any one side in the leftward/rightward direction, it is possible to prevent the seated person from mistakenly operating the operation member 95 and the operating part 80.
In addition, in the chair 1 according to the embodiment, the regulating part 93 and the return part 92 are located with the base member 91 sandwiched therebetween when seen in the widthwise direction.
With this configuration, the regulating part 93 and the return part 92 can be positioned so as not to interfere with each other.
In addition, in the chair 1 according to the embodiment, the base member 91 has the intermediate portion 911 between the first support part 912 and the second support part 913, and both end portions of the intermediate portion 911 in the widthwise direction are supported by the first side support plate 734 and the second side support plate 735 (two flange portions) provided on the chair 1.
With this configuration, the base member 91 can be reliably supported by the chair 1, and the operation member 95 and the operating part 80 supported by the base member 91 can be operated in a stable state.
Hereinabove, while the embodiment of the chair according to the present invention has been described, the present invention is not limited to the above-mentioned embodiment and may be appropriately changed without departing from the scope.
For example, in the embodiment, while the base member 91 is provided on the backrest 20, it may be provided on a member of the chair 1 other than the base member 91 such as the support base 40, the seat 17, or the like.
In addition, in the chair 1 according to the embodiment, while the base member has a rod shape extending in the widthwise direction, it may be a plate shape or a block shape or may be a member extending in the forward/rearward direction.
In addition, in the chair 1 according to the embodiment, while the base member is the shaft portion having the axis 91a extending in the widthwise direction and the operation member 95 and the operating part 80 are coaxially disposed on the axis 91a of the base member 91, it may be disposed at a position where axes thereof are shifted. The operation member 95 and the operating part 80 may be configured to be operable by sliding in addition to rotation.
In addition, in the chair according to the embodiment, while the operation member 95 of the regulating part 93 is rotatable around the axis 91a of the base member 91 relative to the base member and the operating part 80 of the return part 92 is fixed to the base member to be relatively non-rotatable around the axis 91a of the base member 91, the operation member 95 may be fixed to the base member to be relatively non-rotatable around the axis 91a of the base member 91 and the operating part 80 may be rotatable around the axis 91a of the base member 91 relative to the base member. Both the operation member and the operating part 80 may be rotatably about the axis 91a of the base member 91 relative to the base member.
In addition, in the chair according to the embodiment, while the regulating part 93 and the return part 92 are disposed with the base member 91 sandwiched therebetween when seen in the widthwise direction, disposition of the regulating part 93 and the return part 92 may be set as appropriate.
In addition, in the chair 1 according to the embodiment, while the operation member 95 of the regulating part 93 is supported by the left sidewall 382a and the operating part 80 of the return part 92 is supported by the right sidewall 382b, the configuration in which the operating member 95 and the operating part 80 are supported by the chair 1 may be other than that described above.
In addition, in the chair according to the embodiment, while the base member 91 is supported by the first side support plate 734 and the second side support plate 735, the aspect by which the base member 91 is supported may be set as appropriate.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2022-038415 | Mar 2022 | JP | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/JP2023/009292 | 3/10/2023 | WO |
