JP2011193927A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a new chair having a simple structure to achieve a reaction force-transmitting portion for associating a back with a reaction force mechanism to avoid the damage of appearance when viewed from the front.SOLUTION: The chair includes a reaction force mechanism 4 for accumulating a reaction force by being compressed, a reaction force-transmitting portion 63 for compressing the reaction force mechanism 4 as the back 3 tilts backward, and transmitting for the reaction force generated by the compression, to the back, and a reaction force-adjusting mechanism 7 for changing the reaction force applied to the back by the reaction force mechanism 4 through the reaction force-transmitting portion 63. In the reaction force-adjusting mechanism 7, the reaction force mechanism 4 is configured such that the rear end side 4b is rotated to be moved to change the attitude thereof with the front end 4a as the fulcrum in association with the reaction force-transmitting portion 63. The attitude of the reaction force mechanism 4 is changed to change the correspondence relationship between the backward tilting angle of the back and the magnitude of a reaction force applied to the back.

Description

  The present invention relates to a chair in which reaction force adjustment of a reaction force mechanism that supports a back load is optimized.

  As one aspect of the reaction force mechanism that supports the backrest load, for example, the one shown in Patent Document 1 is known. In this type, a grip that also serves as a retainer is screwed into an elastic member such as a compression coil spring having a rear end supported by a support base and a front end as a free end. Then, by screwing the grip, the initial compression amount of the elastic member that gives the reaction force to the backrest is changed via the reaction force transmission unit, thereby adjusting the magnitude of the backrest reaction force, Locking hardness etc. can be realized.

JP 2004-166927 A

  By the way, in addition to the above configuration, as a configuration for changing the reaction force applied to the back by the reaction force mechanism, the reaction force mechanism is configured to be rotatable, and the reaction force mechanism is rotated to change the angle of the reaction force mechanism. It is conceivable as one effective means to change the reaction force applied to the back by the above. In order to realize this, when a reaction force mechanism is provided based on the above-described conventional example so that the rear end is a fulcrum and the front end is a free end, the rear back and the front end of the reaction force mechanism must be associated with each other. In addition, the transmission path becomes longer and the positional relationship with other component parts makes the reaction force transmission part complex, and if the reaction force transmission part is arranged in front of the reaction force mechanism, it is below the front end side of the seat. In addition, since the component parts and the elastic members constituting the reaction force transmission part droop greatly, there is a risk of deteriorating the appearance from the front.

  The present invention has been made paying attention to such a problem, and in realizing a chair having a function of changing the reaction force of the reaction force mechanism that supports the back, the reaction between the back and the reaction force mechanism is related. An object of the present invention is to provide a chair having a new configuration in which the force transmission unit can be configured in a simple manner and the appearance from the front is not impaired.

  In order to achieve this object, the present invention takes the following measures.

  That is, the chair of the present invention includes a reaction force mechanism that accumulates a reaction force by compression, a reaction force transmission unit that compresses the reaction force mechanism with a backward tilting operation and simultaneously transmits the reaction force due to compression to the back, The reaction force mechanism includes a reaction force adjustment mechanism that changes a reaction force applied to the back via the reaction force transmission unit, and the reaction force adjustment mechanism uses the reaction force mechanism as a fulcrum at its front end. The rear end side is associated with the reaction force transmission unit so as to be able to perform a posture change operation by rotation, and is applied to the back tilt angle and the back by changing the posture of the reaction force mechanism. The correspondence relationship with the magnitude of the reaction force is changed.

  According to this configuration, since the front end of the reaction force mechanism is the rotation fulcrum and the rear end side is associated with the reaction force transmission unit, the reaction force applied to the back by adjusting the posture by rotation is adjusted. Compared with adjusting the reaction force as the reaction force output end associated with the reaction force transmission part, the reaction force output end of the reaction force mechanism is closer to the back and the load due to the back tilting action is applied to the reaction force mechanism. It becomes easy to input and the reaction force transmission part can be made into a simple structure. In addition, since it is not necessary to dispose the reaction force transmission portion in front of the reaction force mechanism, the appearance from the front is not impaired.

  In order to realize a large adjustment amount by a slight displacement, the reaction force mechanism includes an elastic member that accumulates the reaction force by compression, and the elastic member that is pressed by the reaction force transmission unit with a back tilting operation. An arm that performs a compression operation by compressing the reaction force, and the reaction force adjustment mechanism is configured so that the elastic member and the arm can integrally perform a posture change operation by rotation, It is preferable that the contact point between the arm and the reaction force transmission unit is moved along the perspective direction with respect to the rotation axis of the arm by changing the posture of the elastic member and the arm.

  In order to facilitate assembly, the reaction force mechanism includes a frame having a rotation fulcrum of the elastic member attached to one end side and a rotation axis of the arm attached to the other end side. It is effective that the free end is held in a portion of the arm displaced from the rotation axis.

  As a specific configuration that realizes a large adjustment amount by a slight displacement, a support base that supports the reaction force mechanism so that the posture can be changed, and a wedge member interposed between the reaction force mechanism and the support base, And operating means for moving the wedge member along an advancing and retreating direction with respect to the rotation center of the reaction force mechanism.

  In order to provide the reaction force adjusting mechanism with a function for holding the wedge member at the adjusted position, at least one of the reaction force mechanism or the support base and the wedge member are temporarily set in a predetermined relative positional relationship. It is desirable to provide a temporary holding unit for holding.

  In order to stabilize the initial compression amount of the reaction force mechanism, an arc surface having a substantially constant distance from the rotation center of the reaction force mechanism is formed in a portion of the arm that contacts the reaction force transmission unit. It is preferable.

  In order to simplify the incorporation of the elastic member and prevent the elastic member from falling off during use, the rotation restriction restricts the arm from rotating from a predetermined limit position in a direction to release the compression of the elastic member. It is effective that a section is provided.

  In order to smoothly input the load caused by the tilting motion of the back from the reaction force transmitting portion to the arm, a part of the reaction force transmitting portion is parallel to the rotational axis of the arm along with the back tilting motion. It is preferable that the arm is rotated around an axis and the arm is pressed at a portion displaced from the center of rotation.

  In order to simplify the assembly work and reduce the manufacturing cost, a convex portion is provided on one of the arm or the elastic member, and a concave portion is provided on the other of the arm or the elastic member. It is preferable that a portion of the arm displaced from the rotational axis is connected to the free end of the elastic member by engaging the convex portion and the concave portion.

  In order to prevent the elastic member from being in an inappropriate posture for compression and impairing the function of the elastic member with a simple configuration, the contact surface of the convex portion and the concave portion is parallel to the rotational axis of the arm. It is desirable to form along the outer peripheral surface of the cylinder centering on the axis.

  As described above, the present invention enables the reaction force mechanism to change its posture by rotation with its front end as a rotation fulcrum, and associates the rear end side with the reaction force transmission unit. The reaction force output end of the reaction force mechanism is closer to the back than when the reaction force is adjusted using the front end side of the reaction force as the reaction force output end associated with the reaction force transmission section, and the load caused by the back tilting action is counteracted. It becomes easy to input to the force mechanism, and the reaction force transmission unit can be configured simply. In addition, since it is not necessary to dispose the reaction force transmission portion in front of the reaction force mechanism, it is possible to provide a new and useful chair that avoids impairing the appearance from the front.

The partial exploded perspective view of the chair of one embodiment of the present invention. The partial exploded perspective view of the support base periphery of the embodiment. The side view of the reaction force mechanism periphery of the embodiment. FIG. 5 is an operation explanatory diagram of a reaction force mechanism corresponding to FIG. 4. The side view corresponding to FIG. 3 after reaction force adjustment. FIG. 6 is an operation explanatory diagram of a reaction force mechanism corresponding to FIG. 5. Sectional drawing which shows the structure and effect | action of the arm periphery of the embodiment. The perspective view which shows the movement switching mechanism of the embodiment. Action | operation explanatory drawing of the lock mechanism of the embodiment. Action | operation explanatory drawing of the restriction | limiting means of the embodiment. Action | operation explanatory drawing of the restriction | limiting means of the embodiment. Action | operation explanatory drawing of the movement switching mechanism of the embodiment.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

  As shown in FIG. 1, the chair of the present embodiment includes a support base 2 supported by the legs 1, a back 3 attached to the support base 2 via a back frame 31 so as to be tiltable, and the back 3. The rotary chair has a reaction force mechanism 4 (see FIG. 2) that supports a load, a seat frame 51 that tilts integrally with the back frame 31, and a seat 5 that is supported by the support base 2.

  More specifically, the leg 1 is a leg blade 12 having a caster (not shown) at its lower end and extending radially from a leg 12a, and the column 11 is protruded from its center by a gas spring (not shown) so as to be lifted and lowered. Therefore, the center of the backrest load is configured to be within the stable support range of the leg blades 12 at any position of the rocking operation of the back 3. The support base 2 is rotatably attached to the column 11 via a connection portion 21.

  The support base 2 is configured by a rigid body such as an aluminum die cast, and includes a top wall 22 and side walls 23 located on both sides of the top wall 22, and a back frame 31 and a seat frame 51 are attached to the side wall 23. And a reaction force adjusting mechanism 7 for adjusting a reaction force applied to the spine 3 by the reaction force mechanism 4 and a lock for restricting the tilting of the back. The mechanism 8 and the like are incorporated. The seat 5 is supported at two points on the side wall 23 of the support base 2 via the shaft 5a on the front end side, and supported at two points on the seat frame 51 via the shaft 5b on the rear end side. Then, it is configured to perform a synchro-rocking operation that sinks backward.

  As shown in FIG. 2, the reaction force mechanism 4 includes a frame 41 having a front end side 41a attached to the side wall 23 of the support base 2 via a shaft 4a, and a front end 42a attached to the side wall 23 of the support base 2 via a shaft 4a. An elastic member 42 such as a compression spring that is attached and accumulates reaction force by compression, and a portion that is rotatably attached to the rear end side 41b of the frame 41 and displaced from the rotation axis 43a to the front end side 43b is elastic. And an arm 43 connected to the rear end 42b, which is a free end of the member 42. By applying a backrest load to the arm 43, the arm 43 rotates around the rotation axis 43a and compresses the elastic member 42. The structure is such that a compression operation can be performed (see FIG. 4). A pressure receiving surface 43 c is formed on the side surface between the base end 43 a and the tip end 43 b of the arm 43. Of course, the reaction force mechanism 4 may be configured using other members that generate a reaction force, such as a gas spring, instead of the elastic member 42.

  Further, the frame 41 and the elastic member 42 constituting the reaction force mechanism 4 are attached to the side wall 23 of the support base 2 so as to be rotatable around the shaft 4 a, and thereby the elastic member 42 constituting the reaction force mechanism 4. The arm 43 is integrally supported by the support base 2 so that the posture can be changed, and constitutes a part of a reaction force adjusting mechanism 7 described later.

  On the other hand, in order to apply the load of the back 3 to the reaction force mechanism 4, as shown in FIG. 1, a locking operation member 6 that rotates according to the locking of the back 3 is rotatably attached to the support shaft 60. . By attaching the idler shaft 62 to a portion of the rocking operation member 6 displaced from the support shaft 60 and attaching the idler shaft 62 to a portion of the back frame 31 displaced from the support shaft 60, the tilting operation of the back frame 31 is achieved. The rocking actuating member 6 rotates in conjunction with the rotation, and the idler shaft 62 moves freely with the rotation. Specifically, the rocking operation member 6 allows the support shaft 60 to pass between the pair of opposing walls 61a and 61a of the channel-shaped bracket 61, and at the portion displaced from the support shaft 60, the pair of opposing walls 61a and 61a. The floating shaft 62 is made to penetrate between 61a. Needless to say, the locking actuating member 6 is interlocked with the rotation of the support shaft 60 not only when the back frame 31 is tilted rearward but also when it is raised.

  As shown in FIGS. 3 and 4, the floating shaft 62 has a structure that advances and retreats toward the pressure receiving surface 43 c of the arm 43 along with the movement, and the floating shaft 62 moves along with the backward tilting motion of the back 3. 62 presses the pressure receiving surface 43c of the arm 43, rotates the arm 43 in the direction in which the reaction force mechanism 4 compresses, and simultaneously receives the reaction force received from the reaction force mechanism 4 through the arm 43 via the back frame 31. The reaction force transmission part 63 which transmits is comprised. The support shaft 60, which is the rotation center of the reaction force transmission portion 63, and the rotation axis 43a of the arm 43 are set in parallel, and smooth load transmission is performed between the floating shaft 62 and the arm 43 constituting the reaction force transmission portion 63. It is possible. Further, as shown in FIG. 3, the pressure receiving surface 43c of the arm 43 is formed in a circular arc shape in which the distance O from the rotation center 4a of the reaction force mechanism 4 is substantially constant when the spine 3 stands up (0 °). The reaction force mechanism 4 is always supported at two locations of the rotation fulcrum 4a and the reaction force transmission portion 63, and the posture is maintained.

  The reaction force adjusting mechanism 7 in FIG. 2 is configured such that the contact point between the floating shaft 62 and the arm 43 constituting the reaction force transmitting portion 63 is along the perspective direction E with respect to the rotation axis 43a of the arm 43 as shown in FIGS. The reaction force mechanism 4 is supported by the support base 2 so that the rear end side 4b can be associated with the reaction force transmission portion 63 and the posture can be changed by rotation with the shaft 4a located at the front end as a fulcrum. Further, as shown in FIG. 2, the wedge member 71 interposed between the reaction force mechanism 4 and the support base 2 and the wedge member 71 are moved along the advancing / retreating direction S with respect to the rotation center 4 a of the reaction force mechanism 4. A reaction force adjusting lever 72 as an operation means is provided.

  As shown in FIG. 2, the reaction force adjusting lever 72 is supported by the support base 2 so as to be rotatable around a shaft 72c, and is associated with a wedge member 71 on the rotation end 72b side. Is slid along the forward / backward direction S.

  2 and 3, the wedge member 71 includes a ceiling wall 71a associated with the reaction force adjusting lever 72, and side walls 71b located on both sides of the ceiling wall 71a. It is configured to be slidable along the forward / backward direction S. The wedge member 71 is slidably held without being dropped from the frame 41 and the like by the wedge guide member 24 disposed at a position sandwiching the upper and both sides thereof, and the wedge guide member 24 and the ceiling wall 71a are brought into contact with each other. The sliding is performed along the advancing / retreating direction S with the lower end of the side wall 71b of the wedge member 71 and the frame 41 being in contact with each other. The distance L between the wedge guide member 24 and the frame 41 in the sliding range of the wedge member 71 is set to be shorter as it approaches the rotation center 4a and longer as it moves away from the rotation center 4a. The distance L between the support base 2 and the frame 41 is changed by sliding the.

  A plurality of arc-shaped protrusions 41 c 1 having the same pitch and the same shape are formed on the contact surface 41 c of the frame 41 that contacts the wedge member 71 along the sliding direction (advancing and retracting direction S) of the wedge member 71. On the other hand, on the contact surface 71c of the wedge member 71 that contacts the frame 41, a plurality of groove portions 71c1 that fit into the protrusions 41c1 are formed at the same pitch as the pitch. Of course, the groove 71c1 may be formed on the contact surface 41c of the frame 41, and the arc protrusion 41c1 may be provided on the wedge member 71. The arc protrusion 41c1 and the groove 71c1 are provided at the contact portion between the support base 2 and the wedge member 71. The shape of the protrusion 41c1 is not limited to the arc shape.

  That is, when the wedge member 71 is moved to the position of FIG. 3 → FIG. 5 by rotating the reaction force adjusting lever 72, the groove 71c1 formed in the contact surface 71c of the wedge member 71 is formed in the contact surface 41c of the frame 41. Since the wedge member 71 moves relative to the support base 2 and the frame 41 while moving the fitting position with respect to the projection 41c1 at a predetermined pitch, the distance L between the support base 2 and the frame 41 is stepwise. And the posture of the reaction force mechanism 4 with respect to the support base 2 is changed stepwise. As shown in FIGS. 3 and 5, the projection 41c1 and the groove 71c1 formed on the frame 41 and the wedge member 71 constitute a temporary locking portion 7X by fitting one recess and the other projection into a wedge. The relative positional relationship between the member 71 and the frame 41 is temporarily held with a constant holding force. The temporary holding portion 7X is set in such a relationship that the fitting position cannot be changed unless the wedge member 71 and the frame 41 are once separated along the rotation direction around the rotation fulcrum 4a. Temporarily held in two relative positions. Of course, the relative positional relationship is not limited to five, and the temporary locking portion 7X may be provided between the wedge member 71 and the support base 2, and the temporary locking portion 7X may not be provided in some cases. Then, the idle shaft 62 constituting the reaction force transmission portion 63 is moved along the pressure receiving surface 43c of the arm 43, so that the contact point between the reaction force transmission portion 63 and the arm 43 to the rotation axis 43a of the arm 43 is reached. The arm length M of the moment changes. When the arm length M of this moment is increased as shown in FIG. 3, the amount by which the elastic member 42 is compressed becomes smaller even when the back is tilted backward (18 °) as shown in FIG. 3 → FIG. Accordingly, when the arm length M is shortened as shown in FIG. 5 as shown in FIG. 5, the elastic member 42 is moved even when the back is inclined backward (18 °) as shown in FIGS. 5 to 6. The reaction force increases as the amount of compression increases. Therefore, changing the posture of the reaction force mechanism 4 changes the correspondence between the rearward tilt angle of the spine 3 and the magnitude of the reaction force applied to the spine 3, that is, the reaction force is adjusted.

  In addition, as shown in FIG. 7, a convex portion 43 d is provided at a portion of the arm 43 that holds the elastic member 42, and a concave portion 42 c is provided at the rear end 42 b (free end) of the elastic member 42. The arm 43 and the elastic member 42 are connected without using a coupling tool by fitting the 43d and the recess 42c. The contact surfaces of the convex portions 43 d and the concave portions 42 c are formed along the outer peripheral surface of a cylinder centering on an axis parallel to the rotation axis 43 a of the arm 43. Of course, the arm 43 may be provided with a concave portion 42c and the elastic member may be provided with a convex portion 43d to connect them. Further, as shown in FIG. 7, a stationary surface 41d is provided in a portion of the frame 41 that is displaced to the side opposite to the elastic member 43a from the rotational axis 43a, and the arm 43 is at a predetermined limit position po1 shown in FIG. At a certain time, a portion of the arm 43 displaced from the rotational axis 43a toward the antielastic member side is brought into contact with the stationary surface 41d, and the arm 43 shown in FIG. The rotation restricting portion 44 is configured to allow only the compression operation and prohibit the operation of the elastic member 42 in the direction of releasing the compression.

  By the way, in a chair having a lock mechanism that restrains the locking of the back, if the restraint of the back is released when the seated person is away from the back, there is a possibility that the back will rise suddenly and shock the seated person. In the present embodiment, in order to prevent such a shock without impairing the feeling of use of the back locking, the following locking device is provided.

  As shown in FIG. 2, the locking device includes a lock mechanism 8 having a function of restricting the tilting of the spine 3 and releasing the restraint of the spine 3 when the lock operation lever 83 is released. Limiting means 8X for restricting the release function of the mechanism 8, and this restriction means 8X restricts the release function when the backrest load is not applied, and releases the restriction when the backrest load is applied. It is configured to do.

  Specifically, as shown in FIGS. 2 and 8, the lock mechanism 8 is provided with an interlocking member 81 that is provided on the support shaft 60 and interlocks with the tilt of the spine 3, and is relatively in contact with the interlocking member 81. A separable regulating member 82 and a movement switching mechanism 85 having a lock operating lever 83 for switching the moving direction of the regulating member 82 are provided, and the interlocking member 81 and the regulating member 82 are operated by the operation performed on the lock operating lever 83. Is engaged so as to restrain the tilt of the spine 3, and when not engaged, the restraint is released.

  As shown in FIGS. 2, 8 and 9, the interlocking member 81 is supported so as to be rotatable around the support shaft 60, and forms a partial sector shape in which the floating shaft 62 is attached to a portion displaced from the support shaft 60. The back frame 31 is configured to drive the idle shaft 62 to interlock the interlocking member 81 with the tilt of the spine 3 when rotating around the support shaft 60. And it has the gear part 81a which arranged the several tooth | gear 81a1 along the circular arc at fixed intervals on the one end side extended in radial direction.

  As shown in FIGS. 2, 8, and 9, the restricting member 82 is a plate having a concave shape corresponding to the fan shape in a part, and at a position facing the interlocking member 81, in the vertical direction A pair of linear sliding surfaces 82b and 82b provided on both sides are slidably disposed on a sliding surface 84a set on a guide member 84 disposed at a position sandwiching the regulating member 82 from above and below. . The regulating member 82 includes a plurality of teeth 82a1 arranged at a constant interval in a concave shape along the arc of the interlocking member 81 at the same pitch as the gear portion 81a of the interlocking member 81 at the end extending to the interlocking member 81 side. The gear member 82a has a gear portion 82a and can slide in the contact / separation direction within a predetermined range so as to be in a meshed state or a non-engaged state with the interlocking member 81. The interlocking operation in the standing direction and the backward tilting direction is prohibited (see FIGS. 9A and 9B). The directions of the teeth 81a1 and 82a1 formed on the interlocking member 81 and the regulating member 82 are set so as to receive a load in a direction perpendicular to the plate thickness direction by meshing. Specifically, as shown in FIGS. 11A and 11B, among the tooth surfaces constituting the teeth 82a1 formed on the regulating member 82, the tooth surfaces on the standing direction side are in contact with the teeth 81a1. Is set to the standing motion regulating surface 82a3 that regulates the interlocking motion toward the standing side of the interlocking member 81, and the interlocking motion toward the backward tilting side of the interlocking member 81 by the contact of the tooth surface on the backward tilting direction side with the tooth 81a1. It is set to the rearward tilting movement regulating surface 82a4 to be regulated.

  However, the gear portions 81a and 82a are provided with a slight backlash-like gap in their meshing, and as shown schematically in FIG. 10 (a) with only the teeth on both sides in the rotational direction exaggerated, A slight interlocking angle range A <b> 1 is set in which the interlocking member 81 can rotate in the meshing state even at the rearward tilt angle. Then, as shown in FIG. 5B, contact / separation prohibition angle ranges A2 and A3 are set on the rising side and the rearward tilt side of the interlocking angle range A1, respectively, and the contact angle between the prohibition angle ranges A2 and A3 is set. A separation allowable angle range A4 is set. In the contact / separation prohibited angle ranges A2 and A3, as shown in FIG. 5A, the standing motion restricting surface 82a3 and the backward tilting motion restricting surface 82a4 are inclined with respect to the contact / separation direction. 82a1 is in a positional relationship in which the two contact directions in the contact / separation direction interfere with each other, and in the contact / separation allowable angle range A4, as shown in FIG. In order to establish the relationship, the shape of the teeth 81a1 and 82a1 and the positional relationship between the standing motion regulating surface 82a3 and the backward tilting regulating surface 82a4 constituting the tooth 81a1 are defined or set. Specifically, as shown in FIG. 11A, between the opening direction op of the two tooth surfaces 81a3 constituting the tooth gap 81a2, the regulating member 82 interlocks with the escape direction esc of the tooth 82a1 (the contact / separation direction). When there is a direction away from the member 81), the tooth 82a1 can be detached from the tooth groove 81a2, and the engagement state between the interlocking member 81 and the regulating member 82 is released, but as shown in FIG. When there is no escape direction esc of the tooth 82a1 between the opening directions op of the two tooth surfaces 81a3, that is, when the tooth 82a1 is in a state of wrapping around the back surface of the tooth surface 81a3, the tooth 82a1 interferes with the tooth space 81a2. The interlocking member 81 and the restricting member 82 are maintained in the engaged state. In particular, as shown in FIGS. 9 and 11 (c), since the teeth 81a1 are arranged along an arc, the opening direction op of the tooth surface 81a3 constituting the tooth groove 81a2 is a tooth groove located from the center. 81a2 is closer to the slide direction (the escape direction esc of the tooth 82a1), and the tooth gap 81a2 located at a position away from the center has an angular difference with respect to the slide direction (the escape direction esc of the tooth 82a1). Therefore, in this embodiment, the contact / separation prohibited state occurs at two locations that mesh with each other on the outermost side along the arc.

  As shown in FIGS. 2, 8, and 9, the movement switching mechanism 85 moves the regulating member 82 that is a moving member toward and away from the urging member 86. A locking operation lever 83 associated with the member 86, and the movement direction of the regulating member 82 is set to a direction approaching the interlocking member 81 (first movement direction) and a direction away from the interlocking member 81 (second movement direction). ) And reciprocating operation.

  As shown in FIGS. 2 and 8, the lock operation lever 83 is rotatably attached to the plate-shaped side wall 23 of the support base 2 via a rotation shaft 83a orthogonal to the plate surface. Alternatively, the release operation is transmitted to the urging member 86. The rotation shaft 83a passes through the elongated hole 82c of the regulating member 82, and a plate-like operation amount transmission member 87 that rotates integrally with the rotation shaft 83a and interlocks with the lock operation lever 83 is attached to the distal end portion thereof. ing. As shown in FIG. 9, the long hole 82 c of the restricting member 82 restricts the sliding range of the restricting member 82 by engaging with the rotating shaft 83 a. As shown in FIG. 8, the regulating member 82 and the operation amount transmitting member 87 are disposed at a position that is substantially parallel to the plate surface of the support base 2 and sandwiches the urging member 86, and are installed close to each other. Has been.

  The urging member 86 is a spring using a single torsion coil spring, and as shown in FIG. 9, one end 86a is attached to a portion displaced from the rotation center 83a of the operation amount transmitting member 87, and the other end 86b is the above-mentioned. It is attached to the regulating member 82, and the regulating member 82 is moved by applying an urging force to the other end 86b using the one end 86a as a scaffold. In this manner, the regulating member 82 is biased by the torsion coil spring even when the crests of the gear portions 81a and the crests of the gear portion 82a abut when the regulating member 82 approaches the interlocking member 81. This is because if the interlocking member 81 is slightly rotated from there, the meshing state can be realized by spring elasticity.

  When the release operation is performed by rotating the lock operation lever 83, the operation amount transmission member 87 rotates as shown in FIG. 9A → FIG. 9B, and one end 86a of the urging member 86 is relative to the other end 86b. The posture of the urging member 86 is changed by moving. As shown in FIG. 12 (a), the urging member 86 has a boundary posture st0 as a thought point where the urging force acts in a direction orthogonal to the guide direction (contact / separation direction) of the slide surface 84a. By switching between the posture st1 of FIG. 12B in which the biasing force is applied in the first movement direction and the posture st2 of FIG. 12C in which the biasing force is applied in the second movement direction with the boundary posture st0 as a boundary. The direction in which the component forces P1 and P2 act on the urging forces P0 and P2 applied to the restriction member 82 by the urging member 86 is switched to the first or second movement direction, and the movement direction of the restriction member 82 is switched. It is configured.

  Further, if the release operation is performed on the lock operation lever 83 in a state where the tilting of the back 3 is restrained, the urging force acting on the regulating member 82 is switched in a direction away from the interlocking member 81, but a backrest load is applied. When not, the interlocking member 81 moves in the upright direction by the reaction force of the reaction force mechanism 4 so that the regulating member 82 receives the reaction force of the reaction force mechanism 4 from the interlocking member 81, and the angle of the interlocking member 81 is as shown in FIG. It is in the prohibition angle range A2 on the standing side shown in FIG. Further, when the seated person slowly leans against the back 3 in this restricted state, the reaction force by the reaction force mechanism 4 received by the regulating member 82 through the interlocking member 81 is reduced, and the angle of the interlocking member 81 is in the forbidden angle range on the backward tilt side. Moving from A3 to the allowable angle range A4, the restriction is removed and the back restraint is released. On the other hand, if a large backrest load is applied in which the seated person leaves his / her body on the back 3 in the restricted state, even if the angle of the interlocking member 81 reaches the allowable angle range A4 from the prohibited angle range A2 on the standing side. Before the separation operation of the teeth is completed, it moves beyond the allowable angle range A4 to the forbidden angle range A3 on the rearward tilt side, and the restriction member 82 again receives the backrest load from the interlocking member 81, and the above restriction is maintained. Is done. When the backrest load is weakened to such an extent that it is substantially balanced with the reaction force of the reaction force mechanism 4, the angle of the interlocking member 81 moves from the forbidden angle range A3 on the backward tilt side to the allowable angle range A4, and the above limitation is eliminated. The restraint is released. As a result, the chair returns to the normal rocking state.

  As described above, the chair of the present embodiment transmits the reaction force due to the compression to the back simultaneously with the reaction force mechanism 4 that accumulates the reaction force due to the compression and the reaction force mechanism 4 as the back 3 is tilted backward. The reaction force transmission unit 63 and a reaction force adjustment mechanism 7 that changes the reaction force that the reaction force mechanism 4 imparts to the back 3 via the reaction force transmission unit 63 are provided. The force mechanism 4 is configured to be able to perform a posture changing operation by rotation with the front end 4a as a fulcrum and the rear end side 4b linked to the reaction force transmitting portion 63, and changing the posture of the reaction force mechanism 4 Thus, the correspondence relationship between the rearward tilt angle of the back 3 and the magnitude of the reaction force applied to the back 3 is changed.

  In this way, the reaction force applied to the spine 3 due to the posture change by rotation is adjusted by associating the front end 4a of the reaction force mechanism 4 with the rotation fulcrum and the rear end side 4b with the reaction force transmission unit 63, Compared with the case where the reaction force is adjusted by using the front end 4a side of the force mechanism 4 as a reaction force output end associated with the reaction force transmitting portion 63, the reaction force output end of the reaction force mechanism 4 and the spine 3 are closer, and the back 3 It becomes easy to input the load caused by the backward tilting operation to the reaction force mechanism 4, and the reaction force transmission portion 63 can have a simple configuration. Moreover, since it is not necessary to arrange the reaction force transmission part 63 in front of the reaction force mechanism 4, the appearance from the front is not impaired.

  In the present embodiment, the reaction force mechanism 4 rotates the elastic member 42 that accumulates the reaction force by compression, and the compression operation that compresses the elastic member 42 by being pressed by the reaction force transmission unit 63 in accordance with the backward tilting operation of the back 3. The reaction force adjusting mechanism 7 is configured so that the elastic member 42 and the arm 43 can integrally perform a posture changing operation by rotation, and the elastic member 42 and the arm 43. Since the contact point between the arm 43 and the reaction force transmission unit 63 is moved along the perspective direction E with respect to the rotation axis 43a of the arm 43 by changing the posture of the contact point, the contact point between the reaction force transmission unit 63 and the arm 43 Is moved in a direction approaching the rotational axis 43a of the arm 43, the reaction force increases as the amount of compression of the elastic member 42 increases even with the back tilt amount of the same back 3, and conversely, the contact point is moved to the arm 43. Rotation Moving in the direction away from the heart 43a, the reaction force by an amount smaller to compress the elastic member 42 in 傾量 after the same back 3 becomes smaller. Then, the reaction force adjusting mechanism 7 changes the posture of the elastic member 42 and the arm 43 as a unit, and moves the contact point between the arm 43 and the reaction force transmitting portion 63 along the perspective direction E with respect to the rotation axis 43a of the arm 43. Therefore, compared with the case where the initial compression amount of the elastic member 42 that gives a reaction force to the backrest is changed by screw feeding or the like, a large adjustment amount can be realized by a slight displacement.

  Further, in the present embodiment, the reaction force mechanism 4 includes a frame 41 in which the rotation fulcrum 4a of the elastic member 42 is attached to the front end side 41a and the rotation axis 43a of the arm 43 is attached to the rear end side 41b. Since the rear end 42b, which is the free end of the member 42, is held in a portion of the arm 43 that is displaced from the rotational axis 43a, the elastic member 42, the arm 43, and the frame 41 are unitized, thus facilitating assembly. It becomes possible.

  Furthermore, in this embodiment, the support base 2 that supports the reaction force mechanism 4 so that the posture can be changed, the wedge member 71 interposed between the reaction force mechanism 4 and the support base 2, and the wedge member 71 include the reaction force mechanism 4. And a reaction force adjusting lever 72 that is an operating means for moving in the advancing and retreating direction S with respect to the rotation center 4a. Therefore, a wedge member interposed between the reaction force mechanism 4 and the support base 2 by the reaction force adjusting lever 72. When 71 is moved in the direction approaching the rotation center 4a of the reaction force mechanism 4, the angle L of the reaction force mechanism 4 with respect to the support base 2 increases due to an increase in the distance L between the reaction force mechanism 4 and the support base 2. Conversely, when the wedge member 71 is moved away from the rotation center 4 a of the reaction force mechanism 4, the distance L between the reaction force mechanism 4 and the support base 2 becomes smaller, whereby the angle of the reaction force mechanism 4 with respect to the support base 2. Becomes smallerA large adjustment amount can be realized by a slight displacement in which the wedge member 71 is moved along the perspective direction E with respect to the rotation center 4 a of the reaction force mechanism 4 by the reaction force adjustment lever 72.

  Furthermore, since the temporary holding portion 7X that temporarily holds the frame 41 and the wedge member 71 constituting the reaction force mechanism 4 in a predetermined relative positional relationship is provided, a function for holding the wedge member at the adjusted position is provided. It becomes possible to grant.

  In addition, a portion of the arm 43 that contacts the reaction force transmission portion 63 is formed with a pressure receiving surface 43c that is an arc surface whose distance M from the rotation center 4a of the reaction force mechanism 4 is substantially constant. Regardless of the posture of the force mechanism 4, the length of the elastic member 42 constituting the reaction force mechanism 4 is substantially constant, and the initial compression amount of the reaction force mechanism 4 can be stabilized.

  Further, in the present embodiment, since the rotation restricting portion 44 that restricts the rotation of the arm 43 from the predetermined limit position po1 toward the direction of releasing the compression of the elastic member 42 is provided, the arm 43 is more than necessary. Does not rotate in the direction of releasing the compression of the elastic member 42, simplifying the incorporation of the elastic member 42 and preventing the elastic member 42 from falling off during use. In particular, when the reaction force mechanism 4 is supported at two locations of the rotation fulcrum 4a and the reaction force transmission portion 63 and maintained in the posture as in the present embodiment, when the arm 43 is at the limit position po1. Depending on the shape of the arm 43, the arm 43 and the reaction force transmission unit 63 may not be in contact with each other in a desired posture, and the desired posture may not be set. On the other hand, when the pressure receiving surface 43c which is an arc surface in which the distance M from the rotation center 4a of the reaction force mechanism 4 is substantially constant is formed in a portion of the arm 43 that comes into contact with the reaction force transmission portion 63, Since the arm 43 and the reaction force transmission portion 63 are in contact with each other regardless of the posture of the reaction force mechanism 4 and the reaction force mechanism 4 is always supported at two points, the reaction force mechanism 4 that can be set to any posture is provided. It becomes possible to do.

  In addition, a part of the reaction force transmission portion 63 is a portion that rotates around the support shaft 60 parallel to the rotation axis 43 a of the arm 43 and is displaced from the rotation center 60 in accordance with the backward tilting motion of the back 3. Since the arm 43 is pressed by the idle shaft 62, it is possible to smoothly input the load due to the tilting motion of the back 3 from the reaction force transmitting portion 63 to the arm 43.

  Further, the arm 43 is provided with a convex portion 43d, the elastic member 42 is provided with a concave portion 42c, and the elastic member 42 and a portion of the arm 43 displaced from the rotation axis 43a by engaging the convex portion 43d and the concave portion 42c. Since the rear end 42b, which is a free end, is connected, the arm 43 and the elastic member 42 can be connected without using a special coupling tool, and the assembling work can be simplified and the manufacturing cost can be reduced. .

  Further, the angle of the arm 43 with respect to the elastic member 42 changes with the rotation of the arm 43, but if both are connected in a state where the angle of the arm 43 and the elastic member 42 is fixed, the elastic member is accompanied with the rotation of the arm 43. 42 may be curved to impair the function of the elastic member 42, but in this embodiment, the contact surface of the convex portion 43d and the concave portion 42c is a cylinder centered on an axis parallel to the rotation axis 43a of the arm 43. Since it is formed along the outer peripheral surface, the contact surfaces slide according to the change in the angle of the arm 43 with respect to the elastic member 42 so that the elastic member 42 has an appropriate posture for expansion and contraction, and the elastic member 42 is inappropriate for compression. It becomes possible to prevent the function of the elastic member 42 from being impaired with a simple configuration.

  The specific configuration of each part is not limited to the above-described embodiment, and various modifications can be made without departing from the spirit of the present invention.

  For example, although the chair which implement | achieves the anti-shock which concerns on this invention is applied to the rotation chair which used the leg blade in this embodiment, you may apply to another chair.

  In addition, the movement switching mechanism according to the present invention is applied to the lock mechanism that restrains the back of the chair in the present embodiment, but may be applied to other mechanisms in the chair, and can be applied to other than the chair. is there.

  Furthermore, in this embodiment, a spring is used as the urging member constituting the movement switching mechanism. However, as long as the urging force is expressed, for example, a gas spring or other mechanism is used. Various modifications can be made without departing from the scope.

2 ... support base 3 ... back 4 ... reaction force mechanism 4a ... rotation center (front end) of reaction force mechanism
4b ... Free end (rear end side)
41 ... Frame 42 ... Elastic member 42c ... Recess 43 ... Arm 43a ... Arm rotation axis 43c ... Arc surface (pressure receiving surface)
43d ... convex portion 44 ... rotation restricting portion 63 ... reaction force transmitting portion 7 ... reaction force adjusting mechanism 71 ... wedge member 72 ... operating means (reaction force adjusting lever)
7X: Temporary holding part po1 ... predetermined limit position

Claims (10)

A reaction force mechanism that accumulates reaction force by compression,
A reaction force transmission unit that compresses the reaction force mechanism with a backward tilting operation and simultaneously transmits a reaction force due to the compression to the back;
A reaction force adjusting mechanism for changing a reaction force applied to the back by the reaction force mechanism via the reaction force transmission unit;
The reaction force adjusting mechanism is configured to perform a posture changing operation by rotation with the reaction force mechanism as a fulcrum at a front end thereof and a rear end side associated with the reaction force transmission unit. By changing the posture of the chair, the correspondence relationship between the back tilt angle of the back and the magnitude of the reaction force applied to the back is changed. The reaction force mechanism includes an elastic member that accumulates a reaction force by compression, and an arm that rotates and compresses the elastic member by being pressed by the reaction force transmission unit in accordance with a back tilting operation. And
The reaction force adjusting mechanism is configured such that the elastic member and the arm can be integrated to perform a posture changing operation by rotation, and by changing the posture of the elastic member and the arm, The chair according to claim 1, wherein a contact point with the reaction force transmission unit is moved along a perspective direction with respect to a rotation axis of the arm.   The reaction force mechanism includes a frame having a rotation fulcrum of the elastic member attached to one end side and a rotation axis of the arm attached to the other end side, and the free end of the elastic member is a rotation shaft of the arm. The chair according to claim 2, wherein the chair is held at a portion displaced from the heart. A support base that supports the reaction force mechanism so that the posture can be changed;
A wedge member interposed between the reaction force mechanism and the support base;
4. The chair according to claim 2, further comprising operating means for moving the wedge member along an advancing / retreating direction with respect to a rotation center of the reaction force mechanism.   The chair according to claim 4, further comprising a temporary holding portion that temporarily holds at least one of the reaction force mechanism or the support base and the wedge member in a predetermined relative positional relationship.   The chair according to any one of claims 2 to 5, wherein an arc surface in which a distance from a rotation center of the reaction force mechanism is substantially constant is formed in a portion of the arm that contacts the reaction force transmission unit. .   The chair according to any one of claims 2 to 6, further comprising a rotation restricting portion that restricts the arm from rotating from a predetermined limit position in a direction to release the compression of the elastic member.   A part of the reaction force transmission part rotates around an axis parallel to the rotation axis of the arm with a back tilting operation, and presses the arm at a portion displaced from the rotation center. The chair according to any one of claims 2 to 7.   A convex portion is provided on either the arm or the elastic member, and a concave portion is provided on the other of the arm or the elastic member, and the rotational axis of the arm is associated with the convex portion and the concave portion. The chair in any one of Claims 2-8 which has connected the site | part displaced from and the free end of the said elastic member. The contact surface of the said convex part and the said recessed part is a chair of Claim 9 formed along the outer peripheral surface of the cylinder centering on the axis | shaft parallel to the rotating shaft center of the said arm.

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