Handle device of furniture and chair

Abstract

To allow an adjustment device including a rotary handle to be idled when an excessive torque is actuated while stabilizing quality of a torque transmission function or the like.SOLUTION: A handle device includes: a ratchet rotor 61 to be integrally rotating with a function member; and a handle 60 fitted to the ratchet rotor 61. The ratchet rotor 61 includes projection parts 90 to be deformed in a radial direction. Irregularity parts 88 to be engaged with the projection parts 90 are formed in the handle 60. When an excessive load is applied, the projection parts 90 are rotated by escaping in an axial direction against its own elasticity and the elasticity of elastic bodies 91. The handle device has a circumferential face cam structure, thereby to stabilize quality compared with an end face cam method.SELECTED DRAWING: Figure 11

Description

Technical Field

[0001] The present invention relates to a rotary handle device for adjusting a movable member in furniture and a chair provided with the handle device.

Background Art

[0002] For example, in a chair, providing a rotary handle has been conventionally done. The most popular one is a handle for adjusting the strength of the resistance (elastic force) against the backward tilt of the backrest in a reclining chair. A male screw is integrally provided on the handle, and by deforming a spring according to the screwing amount, the elastic force against reclining is adjusted (for example, Patent Document 1).

[0003] As a technique for adjusting the front-rear length (depth of the front end) of the seat, there is a method of winding the front part of the seat downward. In this type, it has also been proposed to adjust the winding amount by rotating the handle.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Now, in a rotary handle, there is a rotation limit, and the rotation stops when the forward rotation is completed or the reverse rotation is completed. In the type where a spring is compressed by screwing a male screw, the resistance to rotation increases as the screwing amount increases. When the resistance reaches the maximum, the rotation of the handle stops. When unscrewing, the resistance gradually decreases, and the resistance is the smallest when the unscrewing is completed.

[0006] For example, in an adjustment mechanism consisting of a rack and a pinion, there is also a type that moves the rack by rotating a handle assembled to the pinion. In this case, the resistance to the rotation of the handle may not change. It is also possible to rotate a cam as an adjustment member, but in this case as well, the resistance to the rotation of the handle may not change.

[0007] In this way, rotary handles are widely used as adjustment means in furniture such as chairs. However, the problem is that when the handle is rotated forward or backward completely, the rotation of the handle may suddenly stop, and an impact may act on the handle or the member to which it is attached, and there has been concern that damage may occur due to the impact.

[0008] Also, there was a problem in that an impact may act on a person's hand due to the sudden stop of the rotation of the handle. In particular, when the resistance differs depending on the rotation direction, since a person tends to increase the rotation speed as the resistance decreases, the impact acting on the hand tends to increase due to the sudden stop.

[0009] Regarding these points, a structure has been proposed in which an end face cam biased by a spring is used to idle the handle when the torque becomes excessive. However, since the end face cam meshes in the axial direction, variations in meshing are likely to occur due to machining errors and assembly errors, and there is a problem in that the quality stability is lacking. Also, since the distance from the rotation axis of the handle to the cam portion cannot be increased, there is a concern that a strong spring is required and the operability deteriorates.

[0010] The present invention has been made to improve such a current situation.

Means for Solving the Problems

[0011] The present invention includes various configurations, and its typical examples are specified in each claim. Among these, the invention of claim 1 is in a handle device for furniture, 「A rotary drive body that rotates within a specified range to perform adjustment work, and a manual handle for rotating the rotary drive body forward and backward are provided. Between the rotary drive body and the handle, there is a torque relief element that allows the handle to rotate freely against the elastic force when a load equal to or greater than the set value is applied to the handle. The torque relief element is composed of a protrusion and an uneven portion that mesh in the radial direction perpendicular to the rotation axis of the handle, and the uneven portion is formed over the entire circumference.」 It has such a configuration.

[0012] The invention of claim 2 is a development example of claim 1. 「The torque relief element is set to allow the handle to rotate freely in either the forward or reverse direction.」 It has such a configuration.

[0013] The invention of claim 3 is a development example of claim 1 or 2. 「A recess is formed on one end face of the handle, and the uneven portion is formed over the entire circumference on the inner circumference of the recess. On the other hand, The rotary drive body is provided with a boss portion that fits into the recess of the handle integrally or via a rotation axis, and the protrusion is provided on the boss portion so as to be able to elastically move radially inward.」 It has such a configuration.

[0014] The invention of claim 4 is a development example of claim 3. 「The boss portion is made of synthetic resin, and the mountain-shaped protrusion is integrally formed with one end as a free end when viewed from the axial direction.」 It has such a configuration.

[0015] The invention of claim 5 is a development example of claim 4. 「The protrusion is formed in a case shape that opens to the handle side, and an elastic member is arranged inside it.」 It has such a configuration.

[0016] The invention according to claim 6 relates to a chair, and this chair is a chair provided with at least one of a backrest that can recline against spring means and a seat whose depth can be adjusted by enclosing the front part, wherein, as one or both of the means for adjusting the elastic resistance against the reclining movement of the backrest and the means for adjusting the depth of the seat, the handle device described in claim 1 or 2 is provided. It has such a configuration.

Advantages of the Invention

[0017] As adjustment means for furniture such as chairs, there are rotary levers in addition to rotary handles. However, levers have problems such as being difficult to apply a large force and difficult to adjust the amount of force applied. On the other hand, a rotary handle has the advantages that a person can firmly grip it and apply a strong rotational torque, so it is easy to operate even when there is a large resistance, and the amount of force applied can be arbitrarily controlled.

[0018] And in the invention of the present application, when a large load acts at the position where the handle has been rotated to the end, the handle will rotate freely, so it is possible to prevent an impact from acting on the handle and the members to which it is attached. That is, it is possible to prevent an overload from being applied to the handle and damaging the members. Therefore, it can contribute to improving durability. Also, since the handle rotates freely while being held by a person's hand, a phenomenon such as the handle suddenly stopping and strongly rubbing the person's hand does not occur, and the burden on the person's hand can also be reduced.

[0019] And the engagement between the protrusion and the uneven portion is a kind of cam - type automatic clutch means. However, when adopting a kind of circumferential surface cam method as in the invention of the present application, there is no axial slide of members such as the handle, so the engagement can be accurately maintained and it has excellent stability. Also, it is easy to process. Furthermore, since the outer diameter is large and the load per unit area on the protrusion and the uneven portion is small, it is also excellent in torque transmission performance and durability.

[0020] For example, in the case of a handle that compresses a spring by screwing in a male screw, as the amount of compression of the spring increases, the rotational resistance of the handle increases, so the rotational speed of the handle in the direction of compressing the spring tends to decrease. Therefore, even when the rotation is completed, an impact that poses no problem may not act. On the other hand, when rotating in the direction of extending the spring, since the rotational resistance decreases, it may be in a state where there is inertia in the rotation. Then, the impact in the state where the rotation is completed also increases.

[0021] Thus, when the resistance is different between forward rotation and reverse rotation of the handle, it is possible to set it to idle during rotation in the direction in which an excessive impact acts. However, when there is not much difference in resistance between forward rotation and reverse rotation, or when high safety is required, it is preferable to adopt a configuration that idles during rotation in any direction as in claim 2.

[0022] In the configuration of claim 3, since the inside of the handle can be effectively utilized to form a clutch mechanism, it can be made compact.

[0023] Synthetic resins such as polypropylene exhibit high spring properties when formed into a plate shape. In claim 4, by utilizing the spring action of the synthetic resin, the protrusion can be engaged with and disengaged from the uneven portion. In particular, since one end of the protrusion is a free end, it can be greatly elastically deformed, and the clutch function of interrupting torque transmission can be firmly maintained.

[0024] In this case, when an elastic member is used in combination as in claim 5, the burden on the protrusion can be significantly reduced, so the durability can be improved. As the elastic member, rubber (or rubber-like material) such as synthetic rubber or natural rubber is suitable, but a spring can also be used.

[0025] As described above, it has long been common practice to use a rotary handle for adjusting the resistance to backward tilting in a reclining chair, and it is also suitable to use a rotary handle for adjusting the depth of the seat. And these handles are often arranged on the sides of the seat. Since the seated person usually rotates the handle without visual confirmation, there is a possibility of applying a strong rotational torque by inertia without knowing the position of the rotation limit. However, the chair according to claim 6 can prevent an overload from being applied to the handle and is excellent in durability and reliability. That is, when the present invention is applied to a chair, its effect is strongly exhibited.

Brief Description of the Drawings

[0026]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Mode for Carrying Out the Invention

[0027] Next, embodiments of the present invention will be described with reference to the drawings. This embodiment is applied to the seat of a rotary rocking chair frequently used for office work. In this application, terms such as "front and back" and "left and right" are used to specify directions, which are based on the orientation of a person sitting in a normal posture. The front view is the direction facing the person sitting. The inside and outside are defined such that the side of the middle part between the left and right is the inside, and the sides of the left and right side parts are the outside.

[0028] In FIGS. 1 to 6, an embodiment (First Embodiment) in which the present invention is applied to a handle device for adjusting the depth of the seat is shown, and in FIGS. 7 to 11, an embodiment (Second Embodiment) in which the present invention is applied to a handle device for adjusting the elasticity of the reclining resistance is shown.

[0029] (1). Basic Structure of Chair and Seat First, the outline of the chair will be described mainly with reference to FIGS. 1 to 3. As shown in FIG. 1, the chair to which this embodiment is applied is a swivel chair frequently used for office work, and the chair includes a leg device 1, a seat 2, and a backrest 3 as basic elements. The leg device 1 has a structure in which a leg support 4 made of a gas cylinder is erected at the center of a base having five leg blades, and casters are provided at the tips of each leg blade.

[0030] A base 5 is fixed to the upper end of the leg support 4, and the left and right first tilting frames 6 and a single second tilting frame 7 are connected to the base 5, and an upper back frame 8 is attached to these tilting frames 6 and 7. The first tilting frame 6 also serves as a lower back frame, and a back plate 3a is attached to the upper and lower back frames 8 to form the backrest 3. The back plate 3a is covered with a stretching ground 3b from the front.

[0031] As shown in Fig. 1(B), the front end of the first tilting frame 6 is connected to the base 5 by a main shaft 9. Therefore, the backrest 3 tilts backward with the main shaft 9 as a fulcrum. As shown in Fig. 2(B) and Fig. 3(A), above the base 5, as an example of a seat receiving member, a synthetic resin seat outer shell 10 is arranged. The seat outer shell 10 has a shallow downward concave shell structure.

[0032] And, for example, as shown in Fig. 3, a laterally protruding arm 11 located below the rear part of the seat outer shell 10 is integrally formed on the first tilting frame 6, and a rear bearing portion 12 provided on the seat outer shell 10 is connected to the tip of the laterally protruding arm 11 by a left - right longitudinal pin 13.

[0033] On the other hand, as shown in Fig. 3(A), left and right joint mounts 14 are protrudingly provided at the front - side part of the base 5, and left and right front receiving portions 15 provided at the front part of the seat outer shell 10 are supported and connected to these joint mounts 14. The upper surface of the joint mount 14 is curved upward in a side view, and the front receiving portion 15 is supported in a state where it can slide smoothly. Therefore, when the first tilting frame 6 tilts backward and the backrest 3 reclines, the seat outer shell 10 and the seat 2 supported thereby tilt backward while the rear end is lowered.

[0034] As shown in Fig. 2, the seat 2 has a synthetic resin seat inner shell 16 and a seat cushion material 17 stretched thereon, and the seat cushion material 17 is attached to the seat outer shell 10. The seat cushion material 17 is covered from above with a stretching ground (skin material) not shown.

[0035] (2). Seat and Seat Outer Shell As shown clearly in Fig. 4, a plurality of (five) horizontally long slits 20 are formed in the area of the front-protruding part of the seat inner shell 16. Therefore, the area of the seat inner shell 16 having the horizontally long slits 20 has become a deformation allowance part 16a that can be wound downward. The part behind the deformation allowance part 16a of the seat inner shell 16 has become a wide base part 16b that does not deform, and the part in front of the deformation allowance part 16a has become a narrow front rigid part 16c that does not deform.

[0036] When a pair of left and right joint brackets 21 protruding downward from the front rigid part 16c are pulled backward, the deformation allowance part 16a is wound downward together with the front part of the seat cushion material 17. Thereby, the front-rear position of the front end of the seat 2 can be adjusted. Therefore, the area of the seat 2 having the horizontally long slits 20 has become a deformation allowance part 2a.

[0037] The horizontally long slits 20 of the seat cushion material 17 extend across the entire left and right lengths, and the part between adjacent horizontally long slits 20 has become a strip-shaped part 22 having a U-shaped form that opens downward in a side view. Adjacent strip-shaped parts 22 have their left and right end-side parts connected by a lower bridge 23.

[0038] The strip-shaped part 22 at the rear end is connected to the base part 16b by the lower bridge 23, and the strip-shaped part 22 at the front end is connected to the front rigid part 16c by the lower bridge 23. Therefore, the deformation allowance part 9a is composed of the group of strip-shaped parts 22 and the group of lower bridges 23. As shown in Fig. 4(A), notches 24 are formed in the left and right outer side parts of the lower bridge 23 in a plan view of the strip-shaped part 22. Therefore, the deformation of each strip-shaped part 22 is facilitated.

[0039] As shown in Fig. 4(A) and Fig. 6(B), a group of downward engaging claws 25 for fixing the ground fabric are formed on the lower surface of the outer periphery of the inner shell. Although only a part is shown in Fig. 9, an edge member 26 made of a resin tape is sewn or welded to the periphery of the ground fabric, and the edge member 26 is fitted and attached to the engaging claws 25. Therefore, the edge member 26 has engaging holes.

[0040] For example, as shown in Fig. 4, the seat outer shell 10 has a bottom portion 10a, left and right inclined wall portions 10b, and a rear wall portion 10c, and forms a tray-like shape that is open upward and forward. Inside this seat outer shell 10, a resin operating body 27 is overlapped from above. The operating body 27 is in the form of a plate with reinforcing ribs, and is basically the left-right width that overlaps the bottom portion 10a of the seat outer shell 10. However, wing portions 29 that overlap the inclined guide portions 28 of the seat outer shell 10 are provided on both left and right sides of the front half.

[0041] On the bottom portion 10a of the seat outer shell 10, a pair of left and right side guide ribs 31 that sandwich the rear portion of the operating body 27 from left and right are formed, and on the side guide ribs 31, retaining pieces 32 that overlap the rear side edges of the operating body 27 from above are provided. Therefore, the rear portion of the operating body 27 is held by the side guide ribs 31 so as not to be laterally displaced and not to come off upward.

[0042] Also, on the front portion of the bottom portion 10a of the seat outer shell 10, a front guide rib 33 having an L-shape in a front view with an upper end forming an inward horizontal piece is formed. On the other hand, on the lower surface of the operating body 27, a longitudinal groove hole (not shown) in the front-rear direction into which the front guide rib 33 enters is formed, and the operating body 27 is attached to the seat outer shell 10 so as to be movable back and forth and not to come off.

[0043] A link 36 described later is arranged at the right side portion of the seat outer shell 10. A link insertion space (not shown) is formed in the operating body 27. As shown in Fig. 4, the front end (inner end) of the link 36 is connected to the operating body 27 via a screw 38, a washer 39, and a bearing ring 40.

[0044] Furthermore, as shown in FIG. 4(B), a two-stage rectangular pedestal 44 having upper and lower two-stage outward pieces 43a and 43b is provided at the left and right outer portions of the front guide rib 33 at the bottom 10a of the seat outer shell 10. On the other hand, as shown in FIG. 3(B), guide long holes 42 extending longitudinally in the front and rear are provided on both the left and right sides of the actuator 27, and as shown in FIG. 4(B), the lower outward piece 43b of the rectangular pedestal 44 is positioned above the upper edge of the guide long hole 42.

[0045] Therefore, the actuator 27 is guided in its forward and backward movement by the rectangular pedestal 44, and the lower outward piece 43b prevents the actuator 27 from detaching from the seat outer shell 10.

[0046] The actuator 27 is biased backward by a tension spring 46 (see FIG. 4) disposed on its right side. For this reason, as shown in FIG. 4(B), a rear spring hook portion 47 for locking the rear end of the tension spring 46 is formed at the rear portion of the bottom 10a of the seat outer shell 10, and a front spring hook portion 48 for hanging the front end of the tension spring 46 is formed on the lower surface of the front end portion of the actuator 27.

[0047] The portion of the seat inner shell 16 behind the deformation allowance portion 16a is fixed to the seat outer shell 10. Therefore, first, as shown in FIG. 2(A), on the bottom 10a of the seat outer shell 10, a side downward boss 49 for mounting on the seat outer shell 10 and left and right longitudinal front downward bosses 50 that engage upwardly in a non-removable manner while being placed on the aforementioned rectangular pedestal 44 are formed. The front downward boss 50 in FIG. 2(B) engages with the upper outward piece 43a in FIG. 4(B) while resting on the lower portion of the rectangular pedestal 44.

[0048] Furthermore, as shown in Fig. 2(B), a pair of downward bosses 50 that abut against the bottom 10a of the seat outer shell 10 are formed on the left and right at the rear of the seat inner shell 16, and screws 38 inserted into the seat outer shell 10 from below are screwed into the downward bosses 50. Therefore, the base of the seat inner shell 16 is held in a state where its front part is held immovable left and right and unable to come out upward by the square pedestal 44 of the seat outer shell 10, and the rear part is fixed to the seat outer shell 10 by the screws 38.

[0049] As can be understood from Fig. 4, a pair of left and right joint members 52 provided at the front end of the actuator 27 are connected to a joint bracket 21 (see Fig. 2(B)) provided on the seat inner shell 16. That is, while the joint bracket 21 is formed in a gable shape in front view having an opening, the joint member 52 has a recess 54 into which the lower part of the joint bracket 21 enters and a hook portion 55 that engages with the opening of the joint bracket 21. The joint bracket 21 is held immovable up and down in the recess 54 of the joint member 52 with the hook portion 55 engaged with its opening.

[0050] For this reason, when the joint member 52 and the actuator 27 move back and forth, the joint bracket 21 moves back and forth, and the deformation allowance portion 16a of the seat inner shell 16 and the seat cushion material 17 are involved or returned. The back-and-forth movement of the actuator 27 is performed by the rotation operation of the handle 60 shown in Fig. 2.

[0051] The seat cushion material 17 is composed of a three-dimensional network formed by entangling and binding a large number of resin fibers that are rich in elasticity and bend like polyester fibers. Therefore, it has a ventilation structure similar to that of a non-woven fabric.

[0052] (3). Seat depth adjustment mechanism Next, the depth adjustment mechanism (device) of the seat will be described. In FIGS. 6(B) and 6(C), the entire depth adjustment mechanism is separately shown. As shown in these figures, the depth adjustment device includes a handle 60 that a seated person rotates, a ratchet rotor 61 that is partially inserted into the handle 60 from the inside, a bearing bracket 62 that the ratchet rotor 61 is partially inserted into from the outside, an intermediate member 63 that is partially inserted into the bearing bracket 62 from the inside, an inner member 64 that completely enters the intermediate member 63 from the inside, a screw shaft 65 disposed inside the intermediate member 63, and a nut-type slider 66 that is screwed onto the screw shaft 65. The outer end of the link 36 is connected to the slider 66. A recessed portion 10d for disposing the bearing bracket 62 is formed in the seat outer shell 10.

[0053] In this embodiment, the ratchet rotor 61, the intermediate member 63, the inner member 64, the screw shaft 65, the slider 66, and the link 36 constitute an interlocking mechanism portion.

[0054] A hexagonal head 67 is fixed to the outer end of the screw shaft 65, and the head 67 is fitted into a hexagonal frame portion 63a formed at the inner end of the intermediate member 63. Therefore, the intermediate member 63 and the screw shaft 65 rotate integrally. A pocket portion 69 for holding a nut 68 is formed at the upper end of the hexagonal frame portion 63a. A worm screw 70 inserted through the pocket portion 69 is screwed into the nut 68, and further, the worm screw 70 is fitted into the head 67 of the screw shaft 65. Therefore, the screw shaft 65 is held so as not to come out of the intermediate member 63. The inner end of the screw shaft 65 is rotatably held by a bearing portion 71 provided at the front end of a side guide rib 31 formed on the seat outer shell 10 (see FIG. 5 for example).

[0055] The slider 66 has a forward projecting portion 66a that is circular in plan view, and the forward projecting portion 66a and the outer end of the link 36 are connected by a screw 38, a washer 39, and a bearing ring 40. The bearing ring 40 is for smooth rotation, and a positioning projection 90 provided on the lower surface is fitted into an engagement hole 76 formed in the link 36.

[0056] The screw 38 is screwed into the link 36. The washer 39 abuts against the upper end of the bearing ring 40, and the height of the cylindrical portion of the bearing ring 40 is slightly larger than the thickness of the forward projecting portion 66a of the slider 66. Therefore, the slider 66 and the link 36 rotate smoothly relative to each other around the vertical axis. The relationship between the inner end of the link 36 and the front end portion 27a of the operating body 27 is the same. As shown in Fig. 4(B), the inner end of the link 36 is connected to the front end portion and the left and right middle portion 27a of the operating body 27.

[0057] As shown in Figs. 6(B) and (C), the inner member 64 has a hollow structure with a flange 64a, and a single-character cut-out hole 77 is formed in its cylindrical portion. The inward-facing surface of the intermediate member 63 has an intermediate diameter portion 63b with a smaller diameter than the hexagonal frame portion 63a, and a stepped hole 78 into which the intermediate diameter portion 63b fits is formed in the bearing bracket 62.

[0058] A pressing rod 79 is inserted through the handle 60 from the outside. A flange 80 is fixed to the outer end of the pressing rod 79, while a recess 81 into which the flange 80 fits is formed in the outer end face of the handle 60, and the flange 80 is fixed to the bottom surface of the recess 81. Therefore, the rod 79 rotates integrally with the handle 60.

[0059] The rod 79 passes through the ratchet rotor 61 and the intermediate member 63, and its tip is fitted into the inner member 64. A pair of fin pieces 82 are formed at the tip of the rod 79, and the fin pieces 82 are fitted into the cut-out hole 77 of the inner member 64. In this state, the inner member 64 is fixed to the rod 79 with a screw 83. Therefore, the inner member 64 rotates integrally with the handle 60. Also, the ratchet rotor 61, the bearing bracket 62, and the intermediate member 63 are held inseparably left and right by the handle 60 and the inner member 64.

[0060] The ratchet rotor 61 has a portion that fits into the intermediate member 63. A pair of fin pieces 84 are provided on this portion, while the intermediate member 63 is formed with a slit groove 85 into which the fin pieces 84 fit. Therefore, the ratchet rotor 61, the intermediate member 63, and the screw shaft 65 rotate integrally.

[0061] As shown in FIGS. 5(A) and 5(D), the handle 60 is formed with a circular hollow hole 87 into which the ratchet rotor 61 partially fits. The inner peripheral surface thereof is an uneven portion 88 in which triangular ridges and valleys are continuous when viewed in the axial direction. On the other hand, in the portion of the ratchet rotor 61 that fits into the handle 60, a pair of guide portions 89 that are in sliding contact with the uneven portion 88 and a pair of protruding portions (engagement spring portions) 90 that fit into and disengage from the uneven portion 88 against elasticity are formed. The protruding portions 90 are pocket-shaped with free ends at their tips, and an elastic shaft 91 made of rubber or the like is mounted inside thereof.

[0062] The protruding portions 90 are mountain-shaped when viewed in the rotational axis direction, and the protruding portions 90 and the uneven portion 88 have a circumferential surface cam structure. Therefore, the protruding portions 90 fit into and disengage from the uneven portion 88 against the combined elastic force of their own elastic restoring force and the elastic shaft 91. Conversely, the handle 60 can be idled in both forward and reverse directions against the elasticity of the protruding portions 90 and the elastic shaft 91.

[0063] Furthermore, since the tips of the protruding portions 90 are free ends, when the handle 60 is moved in either the direction of the solid-line arrow or the dotted-line arrow, the handle 60 idles due to the protruding portions 90 being tilted and deformed.

[0064] As shown in FIGS. 5(A) and 5(B), a bulging portion 92 that bulges downward and enters inward is formed on the left inclined wall portion 10b of the seat outer shell 10. A bearing bracket 62 is overlapped and arranged on the bulging portion 92 from the outside, and the bearing bracket 62 is fixed to the inclined wall portion 10b by two front and rear screws 93.

[0065] For example, as shown in FIG. 11, a nut insertion hole 61a is open on the inner front surface of the bearing bracket 62, and the screw 93 is screwed into the nut attached to the nut insertion hole 61a. As shown in FIG. 8(A), a hole 94 through which the intermediate member 63 can pass is provided in the bulging portion 92. As shown in FIGS. 8(B)(C) and FIGS. 9(B)(C), the inner end portion 60a of the handle 60 is formed to have a slightly smaller diameter so as to partially enter the bearing bracket 62.

[0066] (4). Summary In the above configuration, the screw shaft 65 is held non - movable left - and - right by the intermediate member 63 and the bearing portion 71 and is only rotatable. Thus, since the ratchet rotor 61, the intermediate member 63, and the screw shaft 65 rotate integrally, when the handle 60 is rotated, the screw shaft 65 rotates and the slider 66 moves back and forth. Then, the link 36 rotates horizontally and the actuator 27 moves back and forth. Thereby, the winding and unwinding of the seat inner shell 16 are performed, and the depth of the seat 2 can be adjusted.

[0067] Precisely, when the screw shaft 65 is a right - hand screw, when the handle 60 is rotated counter - clockwise, the slider 66 moves forward toward the inside and the winding of the seat 2 is performed. When the handle 60 is rotated clockwise, the slider 66 moves backward and the unwinding of the seat 2 is performed.

[0068] When a person's foot hits the front end of the seat 2 from the front and a rearward external force acts on the seat 2, an external force that causes the slider 66 to move backward outwardly via the link 36 acts on the slider 66. Conversely, when an external force that causes the actuator 27 to move forward acts due to the elastic restoring force of the seat cushion material 17 and the seat inner shell 16, an external force that causes the slider 66 to move inwardly via the link 36 acts on the slider 66. However, since the actuator 27 hits the screw thread of the screw shaft 65 from the left - and - right direction (axial direction), the screw shaft 65 does not rotate. Therefore, the depth of the seat 2 is held at the desired adjusted position.

[0069] Now, since the deformation allowance portion 2a of the seat 2 is trying to return in the unwinding direction, the handle 60 can be rotated with a light force in the direction of advancing the front end of the seat 2. However, since it is not possible to visually confirm whether the seat 2 has fully advanced, if the handle 60 and the screw shaft 65 cannot rotate relative to each other, the seat 2 may suddenly stop from a state with a bounce where it has fully extended or contracted, and there is a risk of damaging the members due to the impact.

[0070] On the other hand, in the embodiment, when an overload is applied in the state where the handle 60 is turned all the way, it will rotate freely, so the members will not be damaged. Also, when the handle 60 rotates freely and a clicking sound is generated, the user can grasp that the seat 2 has fully advanced. Therefore, the ratchet rotor 61 and the uneven portion 88 function as a safety device for preventing damage to the members.

[0071] The members constituting the depth adjustment mechanism, except for the slider 66 and the link 36, are integrally incorporated with the bearing bracket 62 as the core member. That is, the handle 60, the screw shaft 65, etc. are assembled to the bearing bracket 62 and unitized into one. Therefore, the labor of member management is significantly reduced during transportation, storage, etc., and the quality can be stabilized by eliminating assembly errors.

[0072] (5). Basic Structure of the Elasticity Adjustment Device In the drawings after FIG. 7, an example applied to an elasticity adjustment mechanism for adjusting the magnitude of the elastic resistance against reclining is shown. The elasticity adjustment mechanism includes a spring unit 30 shown in FIGS. 7 and 8. Note that the reference numerals attached after FIG. 7 have no relation to FIGS. 1 to 6 for the basic body, but common reference numerals are used for the handle device.

[0073] For example, as shown in FIG. 7, as a member for rotating the spring unit 30, a cam 40 having a number of cam surfaces formed on its outer periphery is horizontally rotatably held by the center boss 29. The cam 40 has an upward cylindrical portion 40a and a disk 41 fixed by screws 38, and a pair of wires 43 are wound around the upward cylindrical portion 40a from opposite directions. As shown in FIG. 7, a pair of ball holding holes 44 are formed inside the upward cylindrical portion 40a of the cam 40. The wires 43 are drawn out to the outside through notch grooves communicating with the ball holding holes 44. The reference numeral 36 shown in FIG. 7 is the upper cover.

[0074] The wires 43 are respectively inserted into tubes (not shown), and the ends of the tubes are held in a non-displaceable manner by a receiving seat 45 provided on the base 5. As shown in FIG. 9, on the right side of the seat cushion material 17, an elastic force adjusting handle 60 is rotatably arranged. When the elastic force adjusting handle 60 is rotated, the pair of wires 43 are pulled in opposite directions to each other and the cam 40 rotates horizontally.

[0075] The horizontal rotation of the cam 40 is converted into the rotation of the spring unit 30 by a slidable 46 that can move back and forth and an inclined guide frame 47 in a rearwardly inclined posture provided on the spring unit 30. As can be understood from FIG. 7 for example, the slider 46 is made of synthetic resin and is rectangular in plan view, and is held by an enclosure member 48 made of a metal plate covering the slider 46 from above so as not to be able to move upward and left and right and to be able to move back and forth.

[0076] The enclosure member 48 has flanges 48a on the left and right, and the flanges 48a are fixed to the base 5 by screws 38. For this reason, the base 5 is provided with an inward step portion 5f where the flanges 48a overlap at the same height as the middle top plate 5d. Further, the enclosure member 48 is formed with a cut-open groove 50 for exposing the inclined guide frame 47 upward.

[0077] As shown in FIG. 8, the spring unit 30 includes a compression coil spring 51 that expands and contracts in a substantially front-rear direction, a fixed-side spring receiver (front spring receiver) 53 that supports the compression coil spring 51 from the front, a movable-side spring receiver (rear spring receiver) 53 that supports the compression coil spring 51 from the rear and against which the arm member 33 abuts, an auxiliary plate 54 that overlaps in front of the movable-side spring receiver 53, left and right side plates 55 made of a metal plate, and an upper lid member 56 that covers the compression coil spring 51 from above.

[0078] The fixed-side spring receiver 52 is made of synthetic resin (it may be an aluminum die-cast product) and is formed in a block shape, and a front support shaft 31 in the left-right longitudinal direction is inserted therethrough. Accordingly, a bearing hole 52a through which the front support shaft 31 passes is formed in the fixed-side spring receiver 52. The front end of the side plate 55 is fixed to the fixed-side spring receiver 52 with a bolt 57. In this case, a cylindrical boss 58 is projected from the fixed-side spring receiver 52, and a fitting hole 59 at the front end of the side plate 55 is fitted into the cylindrical boss 58.

[0079] The upper lid member 56 is made of synthetic resin and is arranged to partially cover the compression coil spring 51 from above, and the side plates provided on the left and right are fixed to the side plates 55 with two front-rear screws 38. On both left and right sides of the upper lid member 56, the above-described inclined guide frames 47 having oblong holes in an inclined posture are integrally formed. The spring unit 30 is inclined so as to descend rearward as a whole. Accordingly, the inclined guide frame 47 is also inclined so as to descend rearward. A cutout groove 77 into which the inclined guide frame 47 is fitted from below is formed in the slider 46, and the slider 46 and the inclined guide frame 47 are connected with a left-right longitudinal slide pin 72.

[0080] For example, as shown in FIG. 7, the cam 40 generally has a D-shaped form, and a plurality (nine cams from the first to the ninth) of cam surfaces are formed on its outer peripheral surface. A support projection (not shown) that selectively abuts against one of the cam surfaces projects rearward from the rear end of the slider 46.

[0081] For example, the arm member 33 is shown in Fig. 8. The arm member 33 is a metal die-cast product and is fixed to the inward-facing hexagonal portion 7b of the first support shaft 7 with screws. On the other hand, the movable-side spring receiver 53 is a molded product of synthetic resin (or a metal die-cast product) and is formed in a triangular shape in side view.

[0082] As shown in Fig. 8, a stopper shaft 73 is inserted into the movable-side spring receiver 53 and held in a non-removable manner. The stopper shaft 73 protrudes from both the left and right sides of the movable-side spring receiver 53, and this protruding portion is inserted through a frame body 75 fixed to the side plate 55 with screws 74. The frame body 75 is made of a metal plate (steel plate), and the exposed portion of the stopper shaft 73 is slidably inserted into a long hole.

[0083] (5). Structure of the Elasticity Adjusting Device As described above, the two wires 43 are in a tension and relaxation relationship with each other. When the cam 40 is rotated by the two wires 43, the arm member 33 rotates, and the contact position between the movable-side spring receiver 53 and the arm member 33 changes in the vertical direction, and the moment acting on the arm member 33 changes, so that the resistance to reclining changes. The pulling operation of the wire 43 is performed by the handle device shown in Figs. 9 to 11.

[0084] The handle device for elasticity adjustment is basically the same as the handle device for the seat, and there are also many identical parts. The same parts are denoted by the same reference numerals as in the first embodiment, and the description thereof is omitted, and only the differences will be described.

[0085] The bearing bracket 62 is also provided for elasticity adjustment. The bearing bracket 62 is fixed to the right side portion of the seat outer shell 10 with screws 93. The screw 93 is screwed into a nut 62b fitted into the bearing bracket 62. A ratchet rotor 61 is rotatably fitted into an outward-facing recess 62c formed in the bearing bracket 62.

[0086] As shown in FIG. 11, this embodiment also includes an intermediate member 63 that rotates integrally with the ratchet rotor 61. An annular groove 95 is formed on the outer peripheral surface of the flange 63a formed on the intermediate member 63, and the wire 43 is wound around the annular groove 95 from the reverse direction. A bolt (not shown) is connected to the end of the wire 43, and the ball engages with a hole 95a provided in the flange 63a. Although only one annular groove 95 is formed, two annular grooves may be formed.

[0087] The wire 43 is inserted through a tube, and a fitting 96 is attached to the end of the tube. The fitting 96 has an annular groove 95, and the fitting 96 is fitted into a holder 98 attached to the bearing bracket 62. That is, a tube holding groove 99 into which the fitting 96 enters laterally is open in the holder 98, and a rib 100 that fits into the annular groove 93 of the fitting 96 is formed in the tube holding groove 99.

[0088] A lateral rib 101 is formed on the holder 98, and the lateral rib 101 fits into an engagement groove 102a provided in a boss portion 102 protruding downward from the bearing bracket 62. The holder 98 also has front and rear flaps 103, and the flaps 103 are fixed to the boss portion 102 with screws 104. The screws 104 are screwed into nuts 105, and the nuts 105 are attached to a thread groove 106 formed in the boss portion 102 from below.

[0089] The wire 43 (tube) is drawn out above the base 5 and is drawn out toward the cam 40 from between the side plate 5a of the base 5 and the upper cover 36. The reference numeral 107 shown in FIG. 9 is a reclining adjustment lever.

[0090] In this embodiment, the left and right of the handle device are the same as those in the first embodiment, and when an overload is applied to the handle 60, the handle 60 rotates freely. Therefore, damage to the handle 60, the ratchet rotor 61, etc. can be prevented.

[0091] The embodiments of the present invention have been described above, but the present invention can be embodied in various other ways. For example, the protruding portion and the uneven portion can be arranged inside and outside in reverse. The meshing concept (engagement / detachment structure) does not necessarily require the use of a resin spring. A ball catch or the like can also be used. It is also possible to arrange three or more protruding portions. Further, the present invention is applicable to adjustment devices of other furniture, such as a height adjustment mechanism of a lifting table.

Industrial Applicability

[0092] The present invention can be embodied in a chair. Therefore, it can be used industrially.

Explanation of Reference Numerals

[0093] 43 wire 60 handle 61 ratchet rotor constituting the interlocking mechanism 62 bearing bracket 63 intermediate member constituting the interlocking mechanism 64 inner member constituting the interlocking mechanism 65 screw shaft constituting the interlocking mechanism 66 slider constituting the interlocking mechanism 88 uneven portion 90 protruding portion

Claims

1. A rotary drive body that rotates within a specified range to perform adjustment work, and a manual handle for rotating the rotary drive body forward and backward are provided. A torque relief element is interposed between the rotary drive body and the handle, and when a load equal to or greater than a set value is applied to the handle, the handle is allowed to rotate freely against the elastic force. The torque relief element is composed of a protrusion and an uneven portion that mesh in the radial direction orthogonal to the rotation axis of the handle, and the uneven portion is formed over the entire circumference. A handle device for furniture.

2. The torque relief element is set to allow the handle to rotate freely in either the forward or reverse direction. The handle device for furniture according to Claim 1.

3. A recess is formed on one end face of the handle, and the uneven portion is formed over the entire circumference on the inner circumference of the recess. On the other hand, The rotary drive body is provided with a boss portion that enters the recess of the handle integrally or via a rotating shaft, and the protrusion is provided on the boss portion so as to be able to elastically move radially inward. The handle device for furniture according to Claim 1 or 2.

4. The boss portion is made of synthetic resin, and the protrusion in the shape of a mountain when viewed from the axial direction is integrally formed with one end as a free end. The handle device for furniture according to Claim 3.

5. The protrusion is formed in a case shape that opens to the side of the handle, and an elastic member is disposed inside. The handle device for furniture according to Claim 4.

6. A chair having at least one of a backrest that can recline against spring means and a seat that can adjust its depth by wrapping the front part. The handle device according to Claim 1 or 2 is provided as either one or both of the elastic resistance adjustment means for the reclining movement of the backrest and the depth adjustment means of the seat. Chair.

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