JP2012135398A - Chair - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a chair which obtains a rocking mechanism and a lock mechanism of rocking motion with a simple and compact configuration.SOLUTION: The chair includes: a support frame 4 supported by a column; a back frame 5 which can rise and fall; a seat frame 6 which moves along the rising/falling motion of the back frame, interlocking with the back frame 5; a reaction force mechanism 7 which accumulates a spring force against the interlocking motion; and a lock mechanism to restrain the interlocking motion. The reaction force mechanism 7 includes a spring case 71 and a spring 72 which can move in a longitudinal direction relatively to the seat frame 6. The spring case 71 is connected to move relatively to the seat frame 6 tilting together while the front end and the rear end are partially restricted to the seat frame 6 during the interlocking motion. The lock mechanism restricts the interlocking motion of the seat frame 6 and the back frame 5 with respect to the support frame 4 by fixing a relative position of the spring case 71 and the seat frame 6.

Description

  The present invention relates to a so-called synchro-rocking mechanism in which a lowering operation on the rear side of a seating surface and a rearward tilting operation are interlocked, and a chair provided with a lock mechanism for fixing these operations at a desired position.

  Various types of chairs having such a mechanism have been proposed. For example, in Patent Document 1, as a structure for realizing a synchro-rocking mechanism, a structure for connecting a seat and a back to a main frame is shown, and a support structure for a reaction force mechanism in which a reaction force is increased or decreased according to a tilt angle of the back I have made a proposal about. Moreover, as a structure which implement | achieves the locking mechanism of locking operation, what locks and cancels | releases by opening and closing of the valve | bulb of a gas spring is shown by patent document 2. FIG. Further, in Patent Document 3, a member that moves with a back tilt of the back is locked by bringing a member that regulates the member into contact with the back. A member having a gear surface that moves or rotates in contact with a member having a gear surface that meshes with the member is shown.

US Patent No. 6,696,611 JP-B-2-24527 JP 2001-128774 A JP 2003-189967 A

  However, in the prior art disclosed in Patent Document 1, the configuration for realizing the synchro-rocking mechanism is complicated, and the position where the lock mechanism for restricting the locking operation can be provided is restricted.

  If a lock mechanism as described in Patent Documents 2 to 4 is further added based on such a configuration, the configuration becomes more complicated and the number of parts becomes larger, which makes it difficult to reduce the size and cost and to cause a malfunction. Is likely to occur. Further, there may be cases where the operability is poor and it is impossible to quickly lock the locking position, or the locking position is displaced even after locking.

  The present invention has been made paying attention to such a problem, and has a simple configuration with a small number of parts, a compact, high operational stability, low cost and good operability. The purpose is to provide a chair equipped.

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

  That is, the chair of the present invention moves in a direction along the tilting motion of the back frame in conjunction with the back frame, the back frame that can be tilted up and down with respect to the support frame. A seat frame associated with the support frame and the back frame, a reaction force mechanism for accumulating spring force against the interlocking operation of the seat frame and the back frame with respect to the support frame, and A locking mechanism for restraining the interlocking movement of the seat frame and the back frame, and a spring case provided in the seat frame by the reaction force mechanism, and a spring associated with the spring case and the seat frame. The spring case is abutted while the front end and the rear end are partially restrained by the seat frame during the interlocking operation. The support frame is associated with the seat frame so as to perform an interlocking operation that moves relative to the seat frame in the front-rear direction while tilting, and the lock mechanism fixes the relative position of the spring case and the seat frame in the front-rear direction. The interlocking operation of the seat frame and the back frame with respect to is restricted.

  In this way, the synchro-rocking mechanism can be realized with a simple configuration, and the locking mechanism for fixing the locking position can be realized by only a seat frame and a spring case in which relative movement is restricted by a part of the member whose position should be restricted. Therefore, there are few restrictions on the installation location, and it can be realized with a simple configuration with a small number of parts. For this reason, it is possible to reduce costs and improve operational stability at the same time as downsizing. Further, since the seat frame and the spring case are always kept close to each other, the operability for fixing these positions is improved, and the positional deviation after the fixing can be reduced.

  In order to further improve the operability and ensure that the locking position can be securely fixed without causing a shift, the spring case is restrained from relative movement in the vertical direction with respect to the seat frame at the front end portion and the rear end portion. Preferably, the front end portion and the rear end portion are provided in the seat frame so as to restrain the relative movement in the left-right direction with respect to the seat frame.

  Further, in order to further enhance the above effect, the lock mechanism includes a stopper member configured to be movable back and forth in a direction orthogonal to the front-rear direction, an advance / retreat mechanism for moving the stopper member back and forth, and a mechanism into which the stopper member is inserted. Preferably, the stopper member and the advance / retreat mechanism are provided on one of the seat frame and the spring case, and the engagement hole is provided on the other.

  Furthermore, in order to further reduce the size, it is preferable that the spring case, the stopper member, and the advance / retract mechanism are configured to be accommodated within the height dimension of the seat frame, and the portion where the engagement hole is provided is a plate. More preferably, the stopper member is configured to fit within the height of the seat frame within a stroke range in which the stopper member advances and retreats.

  Further, in order to make it possible to finely change the locking position of the locking and to further enhance the basic function of not causing positional deviation after locking, the engagement hole is a slit extending in a direction perpendicular to the front-rear direction. The stopper member is formed in a plate shape at a predetermined pitch, and has a protruding portion that fits into the engagement hole, and one surface of the stopper member is It is preferable that the stopper member is advanced and retracted while being guided by the inner surface of the stopper case that houses the stopper member.

  Furthermore, in order to reduce the load on the stopper member and increase the operational stability, the stopper case is fixed to the seat frame, the engagement hole is provided in the spring case, and the protruding portion of the stopper member It is preferable that an auxiliary engagement hole capable of tightly moving back and forth is provided in the seat frame so that the protruding portion of the stopper member is inserted simultaneously at a position where the engagement hole and the auxiliary engagement hole overlap.

  Furthermore, in order to achieve a more compact configuration, the advance / retreat mechanism includes a stopper case that houses the stopper member, an operation lever that operates the stopper member to advance and retract, and a forward / backward movement of the stopper member due to the displacement of the operation lever. It is preferable that the spring member is arranged so that the urging direction is switched between the release position and the lock position.

  According to the present invention described above, it is possible to improve the operability while satisfying the basic function of having a synchro-rocking mechanism and a lock mechanism for restricting the operation thereof, and that the position does not shift after being locked. It becomes. Furthermore, since the lock mechanism can be realized with a simple configuration, it is possible to reduce the size, reduce the number of parts, reduce the manufacturing cost, and improve the operational stability.

The side view of the chair which concerns on one Embodiment of this invention. The exploded perspective view of the chair. The principal part perspective view explaining the link mechanism between the frames of the chair. The perspective view of the support frame which comprises the chair. The centerline longitudinal cross-section perspective view of the seat frame which comprises the chair. The disassembled perspective view of the reaction force mechanism and lock mechanism of the chair. The cross-sectional perspective view of the reaction force mechanism of the chair. Sectional perspective view of the reaction force mechanism when the back frame of the chair tilts backward. Sectional drawing explaining operation | movement of the reaction force mechanism at the time of engaging the seat frame and reaction force mechanism of the chair with a support frame and a back frame. The principal part perspective view which shows the assembly state of the stopper mechanism of the chair. The principal part perspective view which shows the decomposition | disassembly state of the stopper mechanism of the chair. Sectional drawing which shows the positional relationship of the stopper member of the same chair, a stopper case, a spring case, and the movable plate of a seat frame. Sectional drawing which shows the principal part explaining the operating mechanism of the locking stopper of the chair. The principal part perspective view explaining the height adjustment mechanism of the seat surface of the chair. Sectional drawing which shows the principal part explaining the assembly method of the height adjustment mechanism of the seat surface of the chair. The principal part perspective view of the state which incorporated the gas spring lever in the support frame of the chair. The principal part perspective view of the state before incorporating a gas spring lever in the support frame of the chair. The principal part perspective view explaining operation | movement of the reaction force adjustment part of the chair. Sectional drawing which shows the principal part explaining the bearing area | region in each engaging part of the chair. The principal part perspective view which shows the engagement state of the bearing member with respect to the front horizontal axis of the chair and a slide hole. Sectional drawing of the principal part at the time of operating the gas spring lever of the chair. The schematic diagram explaining the insertion and removal angle of the gas spring lever of the chair.

  Embodiments of the present invention will be described below with reference to the drawings.

  As shown in FIGS. 1 and 2, the chair according to this embodiment is a rotary chair in which a chair body 3 is rotatably attached to a leg blade 11 via a support 12, and a support frame 4 supported by the support 12 and A back frame 5 and a seat frame 6 are provided, and as shown in FIG. 3, a link mechanism is configured by engaging each other.

  Here, in the present invention, the direction from the center of the chair toward the back 31 is the rear direction, and the opposite direction is the front direction. That is, the left direction in FIG. 1 is the front direction, and the right direction is the rear direction. The vertical direction is referred to as the up-down direction or the vertical direction, and the direction orthogonal to the front-rear direction and the up-down direction is defined as the horizontal direction or the left-right direction.

  As shown in FIG. 4, the support frame 4 is integrally molded using a material such as aluminum die-casting or resin, and has a boat shape including left and right side walls 411, a rear wall 412, a front wall 413 and a bottom wall 414. The main frame 41 is a main body, the boss hole 42 which is an attachment hole for attaching the column 12 to the main frame 41, the lateral rib 415 connecting the left and right side walls 411 and 411, the front wall 413 and the rear wall 412. The vertical ribs 416 and the diagonal ribs 417 for connecting the horizontal ribs 413 or supporting the boss holes 42 to the main frame 41 are at least integrally formed. Further, in the vicinity of the upper portion of the boss hole 42, a gas spring lever mounting portion 43 having a mounting hole 431 for mounting a gas spring lever described later is provided. A front horizontal shaft 44 is integrally formed on the upper portion of the front wall 413 of the main frame 41, with protrusions protruding left and right connected together. The front horizontal axis 44 is functionally divided into three areas, and an area protruding left and right from the main frame 41 has an engaging portion 441 as a second horizontal axis for engaging the seat frame 6, The formed region is set to an engaging portion 442 as a fourth horizontal axis for engaging a spring case, which will be described later, and these are configured to be coaxial. In addition, a rear horizontal shaft 45 as a first horizontal shaft protruding left and right is integrally formed on the left and right side walls 411 of the main frame 41.

  As shown in FIG. 2, the back frame 5 is integrally molded using a material such as aluminum die-casting or resin, and the middle part of the pair of left and right frame members 51 is a protrusion as a third horizontal axis. The intermediate horizontal shaft 52 is connected to each other, and a forward opening concave portion 53 having a shape in which a part of the cylinder is notched is formed at the lower end portion. The frame member 51 is integrally formed with a gentle mountain-shaped raised portion 511 extending in a direction different from the extending direction, that is, the standing direction of the back frame 5, and the intermediate horizontal shaft 52 is a position connecting the inner surfaces of the left and right raised portions 511. Is arranged.

  As shown in FIGS. 5 and 6, the seat frame 6 is integrally molded using a resin material, and a pair of left and right main frames 61 formed so as to extend in the front-rear direction are replaced with a front wall 611 and a bottom wall 616. The main frame 61 is formed in a shape in which an inner wall 612 and an outer wall 613 formed in a plate shape are connected by a lateral rib 614. The seat frame 6 is provided with a cavity 65 for containing a spring case, which will be described later, on the upper side, with the rear end serving as an open end 69 and at a position across the front of the inner wall 612 and the front wall 611. Is provided with an upper lid 615. Further, the bottom wall 616 and the inner side wall 612 end at the bottom of the upper lid 615, a connecting space 63 is formed below the upper lid 615, and the inner side wall 612 has a long slide-like rotary slide hole 62 in a side view. However, it is opened downward with a part cut away.

  As described above, the seat frame 6 according to the present embodiment includes the cavity portion 65 having an upper opening. However, the seat frame 6 does not necessarily have a shape in which the upper portion of the cavity 65 is opened. It is good also as a shape which closes an upper part, or a shape which opened the lower part.

  Further, the inner side wall 612 and the outer side wall 613 of the seat frame 6 extend rearward from the bottom wall 616, and a downward opening recess 64 having a shape in which a part of the cylinder is cut is formed below the extension. is doing. The downward opening concave portion 64 has an inner depth as a bearing surface along the partial cylindrical surface, and an opening end faces obliquely forward and downward.

  4, 5, and 7, the front wall 413 of the support frame 4 is inserted into the connection space 63 of the seat frame 6, and is provided near both ends of the front horizontal shaft 44 on the upper portion thereof. By engaging the seat frame engagement portion 441 thus formed with the rotation slide holes 62 provided on the left and right inner walls 612 of the seat frame 6, the front horizontal shaft 44 and the rotation slide hole 62 cause the rotation slide engagement portion 91 to move. It is composed. Then, as shown in FIG. 3, the forward opening recessed portion 53 of the back frame 5 is engaged with the rear horizontal shaft 45 of the support frame 4 so as to be able to move up and down, and further, the seat frame 6 is attached to the intermediate horizontal shaft 52 of the back frame 5. By engaging the downward opening recess 64, the engagement portion 92 of the back frame 5 and the support frame 4 and the engagement of the seat frame 6 and the back frame 5 as shown in FIGS. 3, 7 and 8. The seat frame 6 is configured to move to the rear while the rear part sinks in conjunction with the backward tilting motion of the back frame 5 and moves to the front while the rear portion is lifted in conjunction with the standing motion of the back frame 5. Synchro-rocking operation is realized.

  Further, a reaction force mechanism 7 is configured to accumulate a spring force that resists the interlocking operation of the seat frame 6 and the back frame 5 with respect to the support frame 4.

  As shown in FIGS. 6, 7 and 8, the reaction force mechanism 7 houses a spring 72 and a movable spring receiver 73 in a downwardly opening spring case 71 configured as a spring support portion of the present invention. 71 is engaged with the front horizontal shaft 44 of the support frame 4, and the movable spring receiver 73 is displaced by the sliding operation of the seat frame 6 relative to the spring case 71 when the back frame 5 is tilted backward, thereby compressing the spring 72. Configured to happen.

  As will be described later in detail, the spring case 71 engages with the support frame 4 at the front end and is regulated in the vertical and horizontal directions by the seat frame 6, and further constitutes a lock mechanism 8 described later. Thus, the rear end portion is also regulated in the vertical direction and the horizontal direction by the seat frame 6. As a result, the spring case 71 moves up and down integrally with the seat frame 6 and can only perform relative movement in the front-rear direction.

  The specific configuration will be described below.

  As shown in FIGS. 6 and 7, the spring case 71 is formed in a rectangular parallelepiped shape including a top wall 711, left and right side walls 712, and a rear wall 713 using a steel material or the like, and has an extension portion. A movable plate portion 714 as a rear end portion of the spring case 71 is extended from a lower portion of a certain rear wall 713 in a rear direction orthogonal to the rear wall 713. Further, the spring case 71 forms a downward opening concave portion 742 by a partial cylindrical surface serving as a bearing surface having a convex portion 741 corresponding to a base point portion 716 formed of a concave portion set on the front end side of the upper wall 711. A bearing member 74 is attached, and a reference spring receiver 75 is provided in the vicinity of the center portion of the rear wall 713 which is an extended portion by being displaced rearward from the base point. The reference spring receiver 75 is provided with a through hole 751.

  The spring case 71 is configured to be engaged with the support frame 4 via the bearing member 74 at the base point portion 716 at the front end portion, and the upper cover 615 of the seat frame 6 is disposed above the upper wall 711. Movement in the direction is restricted. Further, in the vicinity of the front end portion, the left and right side walls 712 are restricted from relative movement in the left and right direction by the inner side walls 612 of the seat frame 6. Here, as described above, since the front horizontal shaft 44 of the support frame 4 and the rotary slide hole 62 are engaged with each other to form the rotary slide engaging portion 91, the seat frame 6 is moved up and down by the support frame 4 at that location. Constrained in direction. Therefore, the front end portion of the spring case 71 is regulated in the vertical direction so as to be sandwiched between the upper lid 615 of the seat frame and the front horizontal shaft 44 of the support frame 4. In this manner, relative movement of the front end portion of the spring case with respect to the seat frame 6 in other than the front-rear direction is restricted.

  Further, the movable plate portion 714, which is the rear end portion of the spring case 71, constitutes a lock mechanism as will be described in detail later together with the seat frame 6, so that relative movement in the vertical and horizontal directions with respect to the seat frame 6 is possible. It is regulated. As a result, the spring case 71 can only perform relative movement in the front-rear direction with respect to the seat frame 6 as a whole.

  The spring case 71 can be inserted / removed from an opening end 69 located behind the cavity 65 of the seat frame 6, and is almost the same height as the seat frame 6 while being accommodated in the cavity 65 of the seat frame 6. The left and right side walls 712 of the spring case 71 are accommodated between the left and right inner side walls 612 of the seat frame 6. As shown in FIG. 20, the bearing member 74 is engaged with the front horizontal shaft 44 of the support frame 4 so as to be able to rotate to constitute the engaging portion 94, whereas the seat frame 6 is as described above. In addition, the sliding movement of the seat frame 6 with respect to the spring case 71 occurs because the rotary slide engaging portion 91 slides back and forth. The spring case 71 rotates from the assembly position shown in FIG. 9 (a) to the use position shown in FIG. 9 (c) from the assembly position shown in FIG. 9 (a) while compressing the spring 72. It acts in a direction to return 71 to the assembly position. Further, the spring case 71 restricts relative movement with respect to the seat frame except in the front-rear direction. As the restricting means, for example, as shown in FIG. 5, first and second slide guide portions 66 and 67 for smoothly sliding the two on the portion of the spring case 71 in contact with the seat frame 6 are provided. Provided.

  The first slide guide portion 66 is a protrusion that is integrally provided on the upper edge of the inner wall 612 of the seat frame 6 and extends in parallel with the bottom wall 616 of the seat frame 6. When the spring case 71 is assembled as shown in FIG. 7, the spring case 71 comes into line contact with the upper surface of the spring case 71 in the lateral direction perpendicular to the front-rear direction. Is pressed downward. Further, as shown in FIG. 5, the second slide guide portion 67 is a protrusion that is provided integrally with the left and right inner walls 612 of the seat frame 6 and extends in the vertical direction. Are curved so as to form a convex shape, and are in line contact with the left and right side walls 712 of the spring case 71 shown in FIG. Yes. In the present embodiment, the first slide guide portion 66 and the second slide guide portion 67 are located at the same place in the front-rear direction from the viewpoint of setting the reference position of the spring case 71 and the ease of manufacturing the seat frame 6. It is provided.

  Further, as shown in FIG. 5, a third slide guide portion 68 is supplementarily provided behind the seat frame 6 at a position different from the first slide guide portion 66 in the front-rear direction. The third slide guide portion 68 is a convex portion integrally provided in a curved shape so as to form a gentle convex on the inside of the bottom wall 616 of the seat frame 6, as shown in FIGS. 6 and 7. The spring case 71 to be assembled is provided at a position slidable with the lower surface of the movable plate portion 714 of the spring case 71, and can be in line contact with the lower surface of the movable plate portion 714 of the spring case 71 in the lateral direction perpendicular to the front-rear direction. By configuring in this way, in addition to the third slide guide portion 68, the bottom wall 616 does not require a particularly high accuracy, and the processing of the seat frame 6 is further facilitated.

  As shown in FIG. 5, the first, second, and third slide guide portions 66, 67, and 68 are provided only at one location along the front-rear direction.

  As shown in FIGS. 6 and 7, the spring 72 in the reaction force mechanism 7 is a helical compression coil spring.

  The movable spring receiver 73 is obtained by integrally extending a spring support extension arm 731 from a spring contact surface 733, and the tip end 734 of the spring support extension arm 731 passes through the inside of the spring 72 and the reference spring support. The movable spring receiver 73 is disposed so as to be inserted through the 75 through holes 751, and the movable spring receiver 73 faces the reference spring receiver 75. The spring contact surface 733 is a part of a channel-shaped displacement transmission member 732, and this displacement transmission member 732 causes the sliding displacement of the seat frame 6 accompanying the rearward tilt of the back frame 5 to the spring via the reaction force adjustment unit 76. It plays a role to tell 72. As shown in FIG. 18, the reaction force adjusting unit 76 abuts the slopes 767 and 768 of the adjustment amount input member 761 and the adjustment amount output member 762, and moves the adjustment amount input member 761 in the left-right direction. 6 to change the position of the displacement transmitting member 732, that is, the position of the spring contact surface 733 to the direction in which the spring 72 shown in FIG. 7 compresses or vice versa. As shown in FIGS. 5 and 7, an adjustment amount input member 761 shown in FIG. In the combined state, the seat frame 6 moves back and forth following the back and forth movement. Then, as shown in FIGS. 18A and 18B, a reaction force adjustment lever 764 is screwed into a screw hole 763 provided in the adjustment amount input member 761, and the reaction force adjustment lever 764 is fitted to the outer end of the reaction force adjustment lever 764. The adjustment amount input member 761 can be screw-fed by operating the provided grip portion 765. Further, as shown in FIGS. 3 and 6, a part of the reaction force adjusting lever 764 is provided with a collar portion 766 that is rotatable on an appropriate position of the seat frame 6 and provided on the shaft in the axial direction. It is engaged and attached so as not to move. Since the reaction force adjusting lever 764 moves in the front-rear direction integrally with the seat frame 6, the relative position with the seated person is kept constant.

  Here, the assembly procedure of the support frame 4, the seat frame 6, the back frame 5, and the spring case 71 will be described with reference to FIG.

  The bearing member 74 of the spring case 71 has a shape of the downward opening recess 742, as shown in FIG. 9A, from the direction intersecting the front horizontal axis 44 of the support frame 4 at least at an assembly angle that is higher than the use angle. Similarly, the rotary slide hole 62 of the seat frame 6 also has the reaction angle mechanism 7 including the spring case 71 inside the seat frame 6 at the assembly angle. The support frame 4 can be attached and detached through an opening from a direction intersecting the front horizontal axis 44. Therefore, at the time of assembly, the reaction force mechanism 7 including the spring case 71 is first assembled in the seat frame 6, and the spring case 71 and the seat frame 6 are simultaneously moved to the front horizontal axis of the support frame 4 with a predetermined assembly angle. 44 can be engaged.

  Then, as shown in FIGS. 9B and 9C, the seat frame 6 is moved from the assembly angle to the use angle in a state where the seat frame 6 is engaged with the front horizontal shaft 44 together with the spring case 71. The force mechanism 7 and the force mechanism 7 can rotate together. At this time, the support frame 4 is provided with a cam surface 46 that urges the movable spring receiver 73 in the spring compression direction as the spring case 71 moves from the assembly angle to the use angle. The cam surface 46 extends rearward and downward substantially along the tangential direction from the front horizontal shaft 44 and turns downward via the R portion. The bottom wall of the seat frame 6 shown in FIG. It is configured to slide with the front surface of an upright portion 617 provided in front of 616. 9A, 9B, and 9C, the spring case 71 rotates about the front horizontal shaft 44 in the bearing member 74, whereas the seat frame 6 has the rotary slide hole 62. While sliding the front horizontal shaft 44 inward, it slides backward and accumulates the initial reaction force during this time. As shown in FIG. 4, the cam surface 46 also serves as a rib that reinforces the front horizontal shaft 44.

  Then, as shown in FIGS. 9A, 9B, and 9C, the forward opening recessed portion 53 of the back frame 5 is engaged with the rear horizontal shaft 45 of the support frame 4 from the orthogonal direction, and the back frame 5 By fitting the downward opening concave portion 64 of the seat frame 6 to the intermediate horizontal shaft 52, the seat frame 6 is fitted between the support frame 4 and the back frame 5, the support frame 4 and the seat frame 6, and the seat frame. 6 and the back frame 5, and the support frame 4 and the spring case 71 accommodated in the seat frame, as shown in FIG. 7, engaging and disengaging fitting portions (engaging portions) 92, 91, 93 and 94 are configured. These engaging portions 91, 94, 93, and 92 are each composed of a combination of a shaft and a concave portion as shown in FIGS. 19A, 19B, 19C, and 19D, and are generally indicated by diagonal lines in the same drawing. Since the shown locations 951, 961, 952, 962, 953, 963, 954, and 964 slide, respectively, these locations are processed to have a smooth surface as a bearing region.

  The initial reaction force of the spring 72 in the state shown in FIG. 7 and FIG. 9C is the direction of the intermediate horizontal shaft 52 of the back frame 5 through the downward opening recess 64 of the seat frame 6 in the direction of the front horizontal shaft 44 of the support frame 4. Therefore, the forward opening recess 53 of the back frame 5 is pressed against the rear horizontal shaft 45 of the support frame 4 to support the back frame 5 in a direction in which the seat frame 6 and the back frame 5 are strongly fitted. The fitting of the frame 4 acts in a direction in which the fitting is increased, and the fitting between the bearing member 74 of the spring case 71 incorporated in the seat frame 6 and the front horizontal shaft 44 of the support frame 4 is also strengthened. As a result, these fitting portions maintain the fitting state with each other using the initial reaction force of the reaction force mechanism 7. Further, as shown in FIGS. 7 to 8, a reaction force exceeding the initial reaction force of the reaction force mechanism 7 is generated in conjunction with the interlocking operation of the back frame 5 and the seat frame 6, and the seat frame 6 and the back frame 5 , The force acting in the direction of deepening the fitting of the back frame 5 and the support frame 4, and the fitting of the support frame 4 and the seat frame 6, respectively.

  In particular, as shown in FIGS. 7, 8, and 19, while the backrest is locked between the standing position and the rearward tilting position, the bearing member 74 is placed on the spring case engaging portion 442 in the vicinity of the center portion of the front horizontal shaft 44. While sliding, it slides on a predetermined bearing region 952 of the front horizontal shaft 44, and the rotation engagement hole 618 of the seat frame 6 has a predetermined bearing of the seat frame engagement portion 441 near both ends of the front horizontal shaft 44. Slide in region 951. Further, the bearing region in which the forward opening concave portion 53 of the back frame 5 has a positional relationship shown in FIG. 9 and in which the fitting force acts on the rear horizontal shaft 45 in a state of being fitted to the rear horizontal shaft 45 of the support frame 4. 954, and the downward opening concave portion 64 of the seat frame 6 is fitted to the intermediate horizontal shaft 52 of the back frame 5, and the bearing region 953 along the surface of the intermediate horizontal shaft 52 on which the fitting force acts particularly. Slide. Therefore, at least the bearing regions of the horizontal shafts 44, 45, 52 are illustrated as an example in FIG. 4 and are parallel to each other as horizontal axes passing through the centers of the horizontal shafts 44, 45, 52. Each of the opening recesses 742, 618, 53, and 64 is similarly configured as a smooth concave sliding surface around the horizontal axis m parallel to each other. The rotary slide hole 62 is also configured according to this.

  In particular, as shown in FIGS. 4 and 2, the rear horizontal shaft 45 that is a protrusion of the support frame 4 is provided with a circumferential groove 451 in a part of the outer peripheral surface, and the circumference that is the outer periphery of the protrusion. At the groove bottom of the groove 451, a meat steal 452 is provided as a deformed portion along the circumferential direction, and an outer peripheral surface other than the meat steal 452 is an intermittent convex sliding surface 453. In the side of the forward opening recessed portion 53 of the back frame 5 to be fitted with this, the rear horizontal shaft 45 protrudes when engaged with the rear horizontal shaft 45 which is a protruding portion of the support frame 4 shown in FIG. A cover portion 54 is provided integrally with the end surface 454. The meat steal 452 can also be used as a grease reservoir, and if used in this manner, the sliding resistance can be further reduced. In addition, a flange-shaped large-diameter portion is formed as a deformed portion on each of the horizontal shafts 44, 45, and 52, which are protruding portions, and the axial displacement of each of the opening recesses 742, 618, 53, and 64 to be fitted is prevented. It is also possible to do. Furthermore, if the relative movement with each of the opening recesses 742, 618, 53, 64 is not hindered, a deformed portion having a shape suitable for assembly may be provided on a part of each horizontal shaft 44, 45, 52.

  Furthermore, this embodiment has a locking mechanism 8 as shown in FIGS. 10 and 11 that restrains the locking operation of the back frame 5 and the seat frame 6 at a predetermined position as shown in FIGS. .

  The lock mechanism 8 includes a stopper case 81 mounted in the seat frame 6, a plate-like stopper member 82 housed therein, and an engagement hole 715 provided behind the spring case 71 and into which the stopper member 82 is inserted. The movable plate portion 714 having the above and the advance / retreat mechanism 85 for moving the stopper member 82 up and down. By configuring the lock mechanism 8 in this way, the movable plate portion 714 as the rear end portion of the spring case 71 is sandwiched between the stopper case 81 and the seat frame 6 so as to be regulated in the vertical direction. Become. Further, as described above, the left and right side walls 712 of the spring case 71 are accommodated between the left and right inner side walls 612 of the seat frame, and are relatively moved in the left and right directions by the second slide guide portion 67 in the vicinity of the rear end portion. Is regulated. Accordingly, the rear end portion of the spring case 71 cannot be moved relative to the seat frame 6 in the vertical direction and the horizontal direction, and can be relatively moved only in the front-rear direction. The relative movement in the front-rear direction is also fixed at a predetermined position by the operation of the lock mechanism 8.

  The advancing / retracting mechanism 85 includes a torsion coil spring 83 that is a spring for applying an operating force in the vertical direction to the stopper member 82 and an operating lever 84. The stopper member 82 is integrally formed of steel or a resin material so as to form a plate shape having two rectangular protruding portions 821 at the lower portion, and is used for attaching the end portion 831 of the torsion coil spring 83 in the vicinity of the upper portion. An insertion hole 822 is provided. The stopper case 81 is integrally formed of steel or a resin material so as to form a channel formed by three planes in which a front wall 811 and a rear wall 812 which are a pair of opposing walls are connected by a bottom wall 813 which is a fixed plate portion. Alternatively, it is bent, and a slit-like engagement hole 814 having substantially the same shape as the protruding portion 821 at the bottom of the stopper member 82 is opened in the bottom wall 813 as shown in FIG.

  In addition, the engagement holes 715 in the movable plate portion 714 at the rear of the spring case 71 are slits having substantially the same shape as the protrusions 821 below the stopper member 82, and are provided at a plurality of positions at a predetermined pitch in the front-rear direction. Note that the bottom wall 616 of the seat frame 6 is also provided with a slit-like engagement hole 618 having substantially the same shape at a position corresponding to the protruding portion 821 of the stopper member 82.

  As shown in FIGS. 10 and 11, the operation lever 84 is formed in a rod shape having a substantially rectangular cross section, the operation end 841 on which a person operates is formed in a flat shape, and the stopper member 82 at the other end is formed. On the side of the action end 842 to be moved up and down, an insertion hole 843 for inserting the end portion 831 of the torsion coil spring is provided on the side surface, and a clearance is formed so that a part is cut out so that the torsion coil spring 83 is accommodated therein. A portion 845 is provided. A pair of attachment shafts 844 for attaching the operation lever 84 to the seat frame 6 is provided between the operation end 841 and the action end 842 in a direction orthogonal to the longitudinal direction of the operation lever 84.

  The stopper case 81 is fixed in the vicinity of the rear of the seat frame 6, and a stopper member 82 is provided inside the stopper case 81 so as to be movable back and forth in the vertical direction while being guided with one side thereof in contact with the front wall 811. The operating end 842 of the operating lever 84 for operating the operating lever 84 is inserted from the lateral direction of the stopper case 81 so that the stopper member 82 and the operating end 842 of the operating lever 84 are closely arranged in the front-rear direction in the stopper case 81. It is configured. The reason why the one surface is brought into contact with the front wall 811 of the stopper case 81 is that the position of the stopper member 82 is stabilized by using the front wall 811 as a guide by closely fitting together with the operating end of the operation lever 84. Even if this is configured to abut against the rear wall 812 of the stopper case 81, the same effect can be obtained, and there is no problem.

  Further, a torsion coil spring 83 is attached between the stopper member 82 and the operation lever 84 so as to be accommodated in a relief portion 845 provided in the vicinity of the action end 842 of the operation lever 84, and a direction orthogonal to the winding direction of the spring. The two spring ends 831 protruding in the opposite directions are inserted into insertion holes 822 and 843 provided in the stopper member 82 and the operation lever 84, respectively. Further, the operation end 841 of the operation lever 84 passes through a lever insertion hole 691 provided in the side wall of the seat frame 6 and protrudes to a position where it can be operated by a person, and the mounting shaft 844 is attached to the outer wall 613 of the seat frame 6. A lever mounting portion 692 provided on the outer surface and configured to grip the mounting shaft 844 is rotatably engaged.

  Therefore, by operating the operation end 841 of the operation lever 84 in the vertical direction, the action end 842 of the operation lever 84 moves up and down in the stopper case 81, which drives the stopper member 82 up and down via the torsion coil spring 83. The stopper member 82 comes into contact with the front wall 811 of the stopper case 81 and moves up and down while being guided by the front wall, and the stopper member 82 protrudes from the engagement hole 815 provided in the bottom wall 813 of the stopper case 81. The part 821 moves forward and backward.

  Then, the protruding portion 821 of the stopper member 82 protrudes from the engaging hole 815 of the stopper case 81 and is inserted into a slit-like engaging hole 715 provided on the movable plate portion 714 of the spring case 71 located below the protruding portion 821. When this happens, the relative movement between the seat frame 6 and the spring case 71 is restricted, and the locking operation is locked.

  Specifically, each unit operates and locks as follows.

  First, the operation lever 84 is operated, and as shown in FIG. 12A, when a spring force is applied to the stopper member 82 that is initially positioned on the upper side in the direction of moving the stopper member 82 downward, the stopper case The protrusion 821 of the stopper member 82 protrudes from the engagement hole 814 provided in the bottom wall 813 of 81 and contacts the spring case 71 on the lower side. At this time, when the slit-like engagement hole 715 provided in the movable plate portion 714 of the spring case 71 is in the corresponding position, the protrusion 821 of the stopper member is inserted therein as shown in FIG. Is done. Even when the slit-like engagement hole 715 provided in the movable plate portion 714 is not located at a position corresponding to the protruding portion 821 of the stopper member 82, the inclination of the back frame 5 can be changed as shown in FIGS. As a result, the relative position between the seat frame 6 and the spring case 71 is changed, so that the engagement hole 715 of the movable plate portion 714 is formed at a position corresponding to the stopper member 82 as shown in FIG. 12B or 12C. If they match, the protrusion 821 of the stopper member is inserted. Further, the stopper member 82 is simultaneously inserted into the slit-like engagement hole 618 of the bottom wall 616 of the seat frame 6.

  Thus, the protruding portion 821 of the stopper member 82 that is regulated in the front-rear direction with respect to the seat frame 6 via the stopper case 81 is fitted into the slit-like engagement hole 715 provided in the movable plate portion 714 of the spring case 71. As a result, the relative movement between the seat frame 6 and the spring case 71 is restricted, and the locking position is locked. At this time, by setting the dimensions so that the protruding portion 821 of the stopper member 82 and the engagement hole 715 of the movable plate portion 714 fit tightly in the front-rear direction, the positional deviation after locking can be reduced. Is possible. Further, in the present embodiment, since the stopper member 82 is simultaneously inserted into the slit-like engagement hole 618 of the bottom wall 616 of the seat frame 6, the shearing force acting on the stopper member 82 is near the protruding portion 821 at the tip. Therefore, the deformation of the stopper member 82 is suppressed.

  Further, as described above, the movable plate portion 714 which is the rear end portion of the spring case 71 is restricted in relative movement in the vertical direction with respect to the seat frame 6, and the engagement hole 715 of the movable plate portion 714 and the seat frame are always provided. Since the position of the slit-like engagement hole 618 of the bottom wall 616 of the No. 6 is close to each other in the vertical direction, the positional deviation is less likely to occur, and it is easy to fit the stopper member 82 into them at the same time. Further, since the movable plate portion 714 which is the rear end portion of the spring case 71 is also restricted in relative movement in the left-right direction with respect to the seat frame 6, the engagement hole 715 of the movable plate portion 714 and the slit shape of the seat frame 6 are provided. It is easy to keep parallel to the engagement hole 618, and the stopper member 82 is more easily fitted. As a result, the operability of the stopper member 82 is improved, and the dimensional difference between the protruding portion 821 of the stopper member 82, the engagement hole 715, and the slit-like engagement hole 618 is reduced to reduce backlash. It is possible.

  When releasing the lock, the operation lever 84 shown in FIG. 10 is operated to lift the stopper member 82 upward as shown in FIG. 12A, and the protrusion 821 is engaged with the engagement hole 618 of the seat frame 6. Further, by removing from the engagement hole 715 of the spring case 71, the restriction of the relative movement between the seat frame 6 and the spring case 71 is released, and the locking operation can be performed again. By performing such an operation, the locking position can be changed to a desired position as shown in FIGS.

  Further, in the present embodiment, as shown in FIGS. 11 and 13, the operation lever 84 and the stopper member 82 are connected by a torsion coil spring 83, and only the one spring member is directed upward with respect to the stopper member 82. It is configured to be able to apply forces in different downward directions.

  That is, as shown in FIGS. 11 and 13, the insertion hole 843 of the torsion coil spring end 831 provided in the vicinity of the action end 842 of the operation lever 84 and the insertion hole 822 of the torsion coil spring end 831 provided in the stopper member 82. The positional relationship is shifted in the left-right direction, and when the ends 831 of the torsion coil spring 83 are respectively attached to the two, the expansion force is always applied between both ends 831 and 831 of the spring. is there. Since the torsion coil spring 83 is supported so as to be able to rotate in the respective insertion holes, the direction is automatically changed to the most balanced position depending on the positional relationship between the two insertion holes 843 and 822. ing.

  Specifically, the operation is performed as follows.

  First, as shown in the left diagram of FIG. 13A, when the operation lever 84 is in the lock-off position, the working end 842 is on the lower side, and the stopper member 82 is lifted upward, As shown in the figure, the torsion coil spring 83 is located in the right direction of the figure with respect to the insertion holes 843 and 822 and is located above the operation lever action end 842. In such a positional relationship, the expanding force by the torsion coil spring 83 gives a force that further moves the operating end 842 of the operation lever 84 downward and the stopper member 82 further upward, and further improves the current state. Stabilize. When the operation lever 84 is displaced to the lock-on position, the positional relationship follows the process of FIG. 13 (b) left figure, (c) left figure, (d) left figure, and (e) left figure. The operating end 842 of the control lever 84 is on the lower side, and the stopper member 82 settles in the positional relationship moved downward. In the process of such an operation, the torsion coil spring 83 moves to the left in the drawing as shown in the right diagram of (b), (c) right diagram, (d) right diagram, and (e) right diagram. Further, the expanding force of the torsion coil spring provides a force that makes the action end 842 of the operation lever 84 further upward and the stopper member 82 further downward, contrary to the lock OFF position. Maintain state. From this state, when the operating lever 84 is changed to the lock OFF position again, it returns to the state shown in FIG. 13G, that is, the same state as FIG. Become.

  Moreover, in the chair of this embodiment, as shown in FIG.2 and FIG.14, the height adjustment mechanism 2 with respect to the seat surface 32 is integrated, and this is the gas spring 21 integrated in the support | pillar 12, and the upper part. It comprises a gas spring lever 22 for pressing a certain projecting element 211. The operating end 221 of the gas spring lever 22 is pulled upward to move the operating end 222 downward with the engaging portion 223 as a fulcrum, and the projecting element 211 of the gas spring 21 is pressed to support the support frame 4. The height of the seating surface 32 can be adjusted via this.

  As shown in FIGS. 14 and 15, the column 12 incorporating the gas spring 21 has a substantially cylindrical shape having a convex portion 121 in a part of its axial direction, and the lower end is inserted into the upper portion of the leg blade 11. A boss hole 42 as a support mounting hole of the support frame 4 is fitted into the upper end, and the support frame 4 is rotatably supported while receiving weight by the convex portion 121. At this time, the projecting element 211 on the upper part of the gas spring lever 22 protrudes from the upper part of the boss hole 42.

  The gas spring lever 22 has a substantially rod-like shape, and an operation end 221 for operating the gas spring lever 22 and an action end 222 for pressing the projecting element 211 have a flat shape that is substantially parallel to the horizontal plane at the non-operation position. Further, the lower surface of the gas spring lever 22 is engaged with the support frame 4 from below between the operation end 221 and the action end 222 at a position closer to the action end 222 than to the center of gravity in the longitudinal direction of the gas spring lever 22. An engaging portion 223 is provided. The engaging portion 223 is an L-shaped hook-like protruding portion that extends slightly below the lower surface of the main body of the gas spring lever 22 and extends toward the working end 222, and is integrated with the main body of the gas spring lever 22. Are molded.

  In the support frame 4, the gas spring lever mounting portion 43 including the mounting hole 431 is provided near the upper portion of the boss hole 42 as described above with reference to FIG. 4. As shown in FIGS. 14 and 15, the gas spring lever 22 is supported in such a manner that its engaging portion 223 is inserted into a mounting hole 431 provided in the support frame 4, and rotates within a certain range around this portion. The operation end 221 overhangs to the side of the chair, and the action end 222 is positioned above the projecting element 211 of the gas spring 21 in the center of the chair.

  Since the center of gravity of the gas spring lever 22 is closer to the operation end 221 than the engaging portion 223, the engaging portion 223 is simply hooked into the mounting hole 431 in the gas spring lever mounting portion 43 of the support frame 4. The lower end 224 behind the engaging portion 223 is stabilized at a position where it abuts on the upper surface of the gas spring lever mounting portion 43. Therefore, in this state, the support column 12 can be easily incorporated into the support frame 4.

  Furthermore, in the present embodiment, as shown in FIGS. 16 and 17, the mounting hole of the engaging portion 223 is only provided when the working end 222 side of the gas spring lever 22 is at a certain angle from the horizontal plane. Further, as shown in FIG. 15, the working end 222 side of the gas spring lever 22 can enter the boss hole 42 of the support frame 4 as shown in FIG. It is composed. Further, after the column 12 is assembled in the boss hole 42 of the support frame 4 with respect to the position of the working end 222 of the gas spring lever 22 during the assembly, the upper portion of the column 12 interferes, and the gas spring lever 22 is inserted. It is configured so that a detachable angle cannot be taken. Therefore, after the support column 12 is assembled, it is impossible to remove the gas spring lever 22 from the support frame 4 without detaching the support column 12 from the support frame 4.

  Specifically, as shown in FIG. 15, in order to allow the hook-like engagement portion 223 provided on the lower surface of the gas spring lever 22 to be inserted into and removed from the mounting hole 431 of the support frame 4, It is necessary to make the angle formed by the spring lever 22 with the horizontal plane greater than or equal to α.

  Here, the limit angle α at which the gas spring lever 22 can be inserted and removed is, as schematically shown in FIG. 22, the thickness t1 of the gas spring lever mounting portion and the tip of the engaging portion 223 of the gas spring lever 22. The angle is uniquely determined by the thickness t2 and the width B of the mounting hole 431 as an angle having a relationship of B × sin α−t1 × cos α = t2.

  As shown in FIG. 15, when the support column 12 is removed, the working end of the gas spring lever 22 can be set to an angle of α or more without interfering with other members, and the gas spring lever 22 is supported by the support frame. 4 can be inserted into and removed from

  However, as shown in FIG. 21, when the support column 12 is incorporated in the support frame 4, even when the gas spring lever 22 is operated and the protrusion 211 of the gas spring 21 is pushed to the maximum extent, The working end 222 interferes with the main body of the gas spring 21 and the angle formed with the horizontal plane can only be up to β. Since β is configured to be sufficiently smaller than α, the gas spring lever 22 once attached cannot be removed at this angle.

  Further, as shown in FIG. 4, the mounting hole 431 of the support frame 4 has a substantially rectangular shape with a long side as a side perpendicular to the longitudinal direction of the gas spring lever 22 engaged therewith. And the engaging part 223 provided in the lower surface of the gas spring lever 22 is comprised so that a cross section may become a substantially rectangular shape so that it may have the contact surface matched with the shape of the said attachment hole 431. FIG. Therefore, the gas spring lever 22 can be stably rotated in the vertical plane during the operation, so that the gas spring lever 22 is not displaced from above the projecting element 211.

  With this arrangement, when the operating end 221 of the gas spring lever 22 is pulled upward, the working end 222 moves downward with the engaging portion 223 as a fulcrum, and the projecting element 211 of the gas spring 21 is pressed. And the height of the seating surface can be adjusted.

  As described above, the chair according to the present embodiment includes the support frame 4 supported by the support column 12, the back frame 5 capable of moving up and down with respect to the support frame 4, and the back frame in conjunction with the back frame 5. A seat frame 6 associated with the support frame 4 and the back frame 5 so as to move in a direction along the up-and-down motion of 5, and an interlocking operation of the seat frame 6 and the back frame 5 with respect to the support frame 4. The reaction mechanism 7 includes a reaction force mechanism 7 that accumulates a spring force to resist, and a lock mechanism 8 that restrains the interlocking operation of the seat frame 6 and the back frame 5 with respect to the support frame 4. A spring case 71 provided in the seat frame 6; and a spring 83 associated with the spring case 71 and the seat frame 6; While the front end portion and the rear end portion are partially restrained by the seat frame 6 during the moving operation, they are associated with each other so as to perform an interlocking operation that moves relative to the seat frame 6 in the front-rear direction while tilting together with the seat frame 6. The lock mechanism 8 is configured to restrain the interlocking operation of the seat frame 6 and the back frame 5 with respect to the support frame 4 by fixing the relative positions of the spring case 71 and the seat frame 6 in the front-rear direction. It is.

  In this way, the synchro-rocking mechanism can be realized with a simple configuration, and the locking mechanism 8 for fixing the locking position also includes a seat frame 6 and a spring case in which relative movement is restricted by a part of the member whose position should be restricted. Since it is only 71, there are few restrictions about an installation place, and it can implement | achieve by the structure with a simple and few number of parts. For this reason, it is possible to reduce costs and improve operational stability at the same time as downsizing. Furthermore, since the seat frame 6 and the spring case 71 are always kept close to each other, the operability for fixing these positions can be improved, and the positional deviation after fixing can be reduced.

  Further, since the spring case 71 is configured such that the relative movement in the vertical direction with respect to the seat frame 6 is restricted at the front end portion and the rear end portion, the operability related to locking at the locking position is improved. Thus, the locking position after locking can be securely fixed without causing a shift.

  Furthermore, since the spring case 71 is provided in the seat frame 6 at the front end portion and the rear end portion so as to restrain the relative movement in the left-right direction with respect to the seat frame 6, the operability is improved. It is still advantageous in terms of improvement and reduction of locking position deviation.

  Further, the locking mechanism 8 is configured to be movable back and forth in a direction orthogonal to the front-rear direction, an advancing / retracting mechanism 85 for moving the stopper member 82 back and forth, and an engagement hole 715 into which the stopper member 82 is inserted. The stopper member 82 and the advance / retreat mechanism 85 are provided on one of the seat frame 6 and the spring case 71, and the engagement hole 715 is provided on the other. It is possible to increase.

  Furthermore, the spring case 71, the stopper member 82, and the advance / retreat mechanism 85 are configured so as to be accommodated within the height dimension of the seat frame 6, respectively, thereby further reducing the size.

  Further, the portion where the engagement hole 715 is provided is formed in a plate shape, the stroke required for inserting / removing the corresponding stopper member 82 is reduced, and the seat frame 6 is moved within the stroke range in which the stopper member 82 advances / retreats. By making it so as to be within the height dimension, it becomes possible to further reduce the size.

  The engagement holes 715 are slits extending in a direction orthogonal to the front-rear direction, and a plurality of the engagement holes 715 are provided in the front-rear direction at a predetermined pitch, while the stopper member 82 is formed in a plate shape and the engagement A protrusion 821 that fits into the hole 715 is provided in a part thereof, and the stopper member 82 is advanced and retracted while one surface of the stopper member 82 is guided by the inner surface of the stopper case 81 that houses the stopper member 82. Since it is configured, it is possible to finely change the locking position of the locking, and it is possible to further enhance the basic function of not causing positional deviation after locking.

  Further, the stopper case 81 is fixed to the seat frame 6, the engagement hole 715 is provided in the spring case 71, and the auxiliary engagement hole 618 in which the protruding portion 821 of the stopper member 82 can advance and retract tightly is provided in the seat frame. 6 and the protruding portion 821 of the stopper member 82 is inserted at the same time at the position where the engagement hole 715 and the auxiliary engagement hole 618 overlap with each other. Can be concentrated only in the vicinity of the projecting portion 821, it is possible to prevent breakage and facilitate the upward and backward movement of the stopper member 82 without applying an excessive force to the stopper member 82. It has become.

  Further, the advance / retreat mechanism 85 has a stopper case 81 that houses the stopper member 82, an operation lever 84 that operates the advance / retreat of the stopper member 82, and a force that moves the stopper member 82 forward / backward due to the displacement of the operation lever 84. The spring member 83 is provided, and the spring member 83 is arranged so that the urging direction is switched between the release position and the lock position, so that the number of parts can be reduced and a more compact configuration can be achieved. .

  The specific configuration of each unit is not limited to the above-described embodiment.

  For example, in the above-described embodiment, as shown in FIG. 10, the stopper case 81 is fixed to the seat frame 6, and the stopper member 82 is configured to be movable back and forth while being restricted in the front-rear direction with respect to the seat frame 6. The stopper member 82 is configured to be inserted into the engagement hole 715 provided on the spring case 71 side. However, in order to simply lock the locking operation, the stopper case 81 and the advance / retreat mechanism 85 are provided on the spring case 71 side. An engagement hole 715 that is fixed and corresponding to the stopper member 82 may be on the seat frame 6 side. However, in order for the seated person to perform the locking operation, it is preferable that the seat frame 6 to which the seat surface is fixed and the operation lever 84 move together in the front-rear direction. For this purpose, a stopper member is provided on the seat frame 6 side. 82 and an advance / retreat mechanism 85 are provided, and the engagement hole 715 is preferably provided in the spring case 71. 6

  Moreover, it is not essential that the direction in which the stopper member 82 is advanced and retracted as in the above-described embodiment is a vertical direction, and any direction that is orthogonal to the front-rear direction may be used. For example, engagement holes 618 and 715 are provided in the side walls 612 and 712 of the seat frame 6 and the spring case 71, and the relative movement in the front-rear direction is restricted by fitting the stopper member 82 into the engagement holes from the left-right direction. It is also possible to constitute so.

DESCRIPTION OF SYMBOLS 4 ... Support frame 5 ... Back frame 6 ... Seat frame 7 ... Reaction force mechanism 8 ... Lock mechanism 71 ... Spring case 72 ... Compression coil spring 73 ... Movable spring receiver 81 ... Stopper case 82 ... Stopper member 83 ... Torsion coil spring 84 ... Operation lever 85 ... Advance / retreat mechanism 714 ... Movable plate part 715 ... engagement hole 821 ... projection part

Claims (9)

A support frame supported by a support; a back frame capable of moving up and down with respect to the support frame; and the support frame and the support frame so as to move in a direction along the back and forth operation of the back frame in conjunction with the back frame A seat frame associated with the back frame, a reaction force mechanism for accumulating a spring force against the interlocking operation of the seat frame and the back frame with respect to the support frame, and the seat frame and the back frame with respect to the support frame. And a lock mechanism for restraining the interlocking operation, the reaction force mechanism includes a spring case provided in the seat frame, and a spring associated with the spring case and the seat frame, the spring case being While the front end and the rear end are partly restrained by the seat frame during the interlocking operation, the seat frame is tilted together. The seat frame is related to the seat frame so as to perform an interlocking movement that moves relative to the seat frame in the front-rear direction, and the lock mechanism fixes the relative position of the spring case and the seat frame in the front-rear direction. And a chair that restrains the interlocking movement of the back frame. 2. The chair according to claim 1, wherein the spring case is restrained from relative movement in a vertical direction with respect to the seat frame at a front end portion and a rear end portion. The chair according to claim 1 or 2, wherein the spring case is provided in the seat frame at a front end portion and a rear end portion, and a relative movement in the left-right direction with respect to the seat frame is restricted. The locking mechanism includes a stopper member configured to be movable back and forth in a direction orthogonal to the front-rear direction, an advance / retreat mechanism for moving the stopper member forward and backward, and an engagement hole into which the stopper member is inserted, and the seat frame or the The chair according to any one of claims 1 to 3, wherein the stopper member and the advance / retreat mechanism are provided in one of the spring cases, and the engagement hole is provided in the other. The chair according to claim 4, wherein the spring case, the stopper member, and the advance / retreat mechanism are each accommodated within a height dimension of a seat frame. 6. The chair according to claim 4, wherein the portion in which the engagement hole is provided is plate-shaped and fits within the height of the seat frame within a stroke range in which the stopper member advances and retreats. The engagement holes are slits extending in a direction perpendicular to the front-rear direction, and a plurality of slits are provided in the front-rear direction at a predetermined pitch, while the stopper member is formed in a plate shape and fits with the engagement holes. A protruding part is provided in a part of the stopper member, and the stopper member is configured to advance and retreat while being guided by an inner surface of a stopper case that houses the stopper member. Item 7. The chair according to any one of Items 4 to 6. The stopper case is fixed to the seat frame, the engagement hole is provided in the spring case, and an auxiliary engagement hole in which the protrusion of the stopper member can be advanced and retracted closely is provided in the seat frame, and the protrusion of the stopper member The chair according to claim 7, wherein the engagement hole and the auxiliary engagement hole are simultaneously inserted at a position where the engagement hole and the auxiliary engagement hole overlap each other. The advance / retreat mechanism includes a stopper case that houses the stopper member, an operation lever that operates the advancement / retraction of the stopper member, and a spring member that applies a force to advance / retreat the stopper member by displacement of the operation lever, The chair according to any one of claims 4 to 8, wherein the spring member is arranged so that a biasing direction is switched between a release position and a lock position.

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