JP5191756B2 - Chair reaction force device - Google Patents

Description

  The present invention relates to a chair reaction force device. More specifically, the present invention relates to a chair reaction force device capable of adjusting reaction force in multiple stages.

  An example of a reaction device for a chair that includes a rod-like spring and generates a reaction force by using elastic deformation of the spring is disclosed in Japanese Patent Application Laid-Open No. 9-56520. This reaction force device is shown in FIG. This reaction force device is provided with a torsion bar 101 as a rod-shaped spring. A central bar 102 of the torsion bar 101 is attached to the bottom surface of the seating seat 104 by a bracket 103. Further, the side bar 105 of the torsion bar 101 is bent rearward and is in contact with and supports the bottom surface of the backrest member 106. When the backrest member 106 is tilted back as shown in FIG. 15B from the state of FIG. 15A, the left and right side bars 105 are tilted downward, causing the central bar 102 to twist, and the backrest member 106 Generates reaction force against backward tilt.

  The magnitude of the reaction force is adjusted by rotating the adjustment bolt 108 of the reaction force adjusting means 107. That is, when the adjusting bolt 108 is rotated to change the screwing amount of the locking plate 109, the locking plate moves up and down. When the locking plate 109 is lowered and the protruding portion 110 is lowered, the amount of twist of the central bar 102 increases and the reaction force generated increases. On the other hand, when the locking plate 109 is raised and the protruding portion 110 is raised, the twisting amount of the central bar 102 is reduced, and the generated reaction force is reduced.

  Further, as a reaction force device that adjusts the magnitude of the reaction force step by step, for example, there is one described in Japanese Patent Application Laid-Open No. 2004-49713. This reaction force device is shown in FIGS. This reaction force device includes three unit urging means 111, 112, 113, and the magnitude of the reaction force generated by switching the unit urging means 111, 113 operated by the switching means 114 is switched. The unit urging means 111, 112, and 113 are provided between the inner cylinder 116 that rotates in conjunction with the swinging of the backrest support rod 115, the outer cylinder 118 having the protrusion 117, and the inner cylinder 116 and the outer cylinder 118. The elastic body 119 is provided. The switching means 114 includes a pair of cylindrical cams 121 and 122 that are rotated by rotating the operation lever 120, a pair of operating members 124 that are moved on the shaft 123 by the cylindrical cams 121 and 122, and the operating member 124 that is A compression coil spring 125 is provided to press against 122.

  The protrusion 117 of the central unit biasing means 112 is always in contact with the stop piece 127 of the support base 126, and when the backrest support rod 115 swings, the elastic body 119 is elastically deformed to generate a reaction force. On the other hand, the protrusions 117 of the unit urging means 111 and 113 on both sides abut against the stop piece 128 when the stop piece 128 has moved to the operating position, but the stop piece 128 has moved to the non-operating position. If it is, it does not contact the stop piece 128. Therefore, only when the stop piece 128 is moved to the operating position, when the backrest support rod 115 swings, the elastic body 119 is elastically deformed to generate a reaction force.

  FIG. 19 is a development view of the cam surfaces of the cylindrical cams 121 and 122. The stop piece 128 to be moved to the operating position is switched according to the rotation angle of the cylindrical cams 121 and 122. Accordingly, by operating the operation lever 120 and changing the rotation angle of the cylindrical cams 121 and 122, the combination of the unit urging means 111, 112, and 113 for generating the reaction force changes, and the magnitude of the reaction force to be generated is changed. be able to.

JP-A-9-56520 JP 2004-49713 A

  However, in the reaction force device using the above-described torsion bar 101, the reaction force is adjusted by changing the screwing amount of the locking plate 109 with respect to the adjustment bolt 108. Therefore, in order to greatly change the reaction force, the adjustment bolt It is necessary to rotate 108 repeatedly. Further, as the reaction force to be generated increases, the force for pushing down the locking plate 109 also increases, so that the force (operation force) required to rotate the adjustment bolt 108 also gradually increases. For these reasons, the reaction force adjustment work is troublesome and the reaction force device is not easy to use. In addition, since the operating force increases with an increase in the reaction force to be generated, the reaction force adjustment is particularly difficult for a person having a small gripping force such as a woman or an elderly person.

  In the reaction device using the unit urging means 111, 112, 113, the elastic body 119 is fixed between the inner cylinder 116 and the outer cylinder 118, and the unit urging means having such a structure is used. Since three of 111, 112, and 113 are provided, the manufacturing cost of the reaction device increases. The operation of the unit urging means 111 and 113 is switched by moving the stop piece 128 on the shaft 123 by the rotation of the cylindrical cams 121 and 122, and it is difficult to downsize the reaction force device. The number of unit urging means 111, 112, 113 cannot be increased so much, and it is difficult to increase the number of stages of reaction force adjustment.

  It is an object of the present invention to provide a chair reaction force device that is easy to adjust reaction force, does not require a large operating force, is suitable for multistage adjustment, and can suppress an increase in manufacturing cost.

  In order to achieve the above object, a chair reaction force device according to claim 1 is provided for each of a plurality of rod or plate springs provided between a base body and a rocking body connected to the base body. An operation switching cam that is displaceable between a projecting position where the cam surface abuts the corresponding spring and a retreat position where the cam surface is located farther from the corresponding spring than the projecting position, and an operation for displacing the operation switching cam The operation switching cam has a cam surface on the outer peripheral surface, and the operating device has a plurality of reaction force adjustment positions with different combinations of the operation switching cam displaced to the protruding position and the operation switching cam displaced to the retracted position. The operation switching cam that is displaced to the projecting position generates a reaction force against the swinging by bending the corresponding spring according to the swinging of the swinging body.

  Therefore, when the rocking body swings with respect to the base body in a state where the bar or plate-shaped spring is in contact with the operation switching cam, that is, in a state where the corresponding operation switching cam is rotationally displaced to the protruding position, the spring Bends and generates a reaction force against swinging. On the other hand, when the spring is separated from the operation switching cam, that is, when the corresponding operation switching cam is rotationally displaced to the retracted position, the spring is bent by the operation switching cam even if the swinging body swings with respect to the base. It does not generate reaction force. The operating device has a plurality of reaction force adjustment positions in which the combination of the operation switching cam at the protruding position and the operation switching cam at the retracted position has different reaction force adjustment positions by switching the reaction force adjustment position by operating the operation device. The number of springs that generate the pressure changes, and the magnitude of the reaction force is switched stepwise.

  In the chair reaction force device according to the second aspect, the operation device is provided with a position display indicating the reaction force adjustment position. Therefore, the operating device can be operated while confirming the position display.

  The chair reaction device according to claim 3 has a plurality of springs having different lengths. When the length of the spring is different, the magnitude of the reaction force generated by the curvature is different. Therefore, variations of reaction force values that can be set can be increased.

  Furthermore, the chair reaction force device according to claim 4 has a plurality of springs having different thicknesses. When the thickness of the spring is different, the magnitude of the reaction force generated by the curvature is different. Therefore, variations of reaction force values that can be set can be increased.

  In the reaction device for a chair according to claim 1, the reaction force is adjusted by rotating the operation switching cam and changing the combination of the operation switching cam at the protruding position and the operation switching cam at the retracted position. The operation can be facilitated, and the operation force required for adjusting the reaction force can be reduced. That is, unlike the case where the reaction force is adjusted by compressing the coil spring, the force necessary for the operation does not increase as the reaction force to be generated is increased. In addition, the springs are thin and easy to install, and by increasing the number of springs installed, multistage reaction force adjustment is possible. Therefore, a reaction force device suitable for performing fine reaction force adjustment can be provided. Furthermore, the structure is simple for the multi-stage adjustment, and an increase in manufacturing cost can be suppressed, and the weight of the chair can be reduced.

  In the chair reaction force device according to the second aspect, since the position display is provided on the operation device, the reaction force can be adjusted while confirming the position display. In addition, since the user of the chair remembers his / her favorite position, it is easy to set the reaction force value to his / her favorite when he / she uses a chair used by another person.

  In the chair reaction force device according to the third aspect, since the plurality of springs have different lengths, the variation of reaction force values that can be set can be increased.

  Furthermore, in the chair reaction force device according to the fourth aspect, since the plurality of springs have different thicknesses, the variation of reaction force values that can be set can be increased.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  1 to 4 show an example of an embodiment of the chair reaction force device of the present invention. The chair reaction force device is provided with a plurality of rods or plate-like springs 3 provided between the base 1 and the rocking body 2 connected to the base 1, and is provided for each spring 3. The operation switching cam 6 which can be rotationally displaced between the protruding position 4 where the surface 6b abuts and the retracted position 5 where the cam surface 6b is located farther from the spring 3 corresponding to the protruding position 4 and the operation switching cam 6 are rotated. An operating device 7 for displacement is provided.

  The reaction force device generates a reaction force that causes the backrest 8 when the backrest 8 is tilted later. In the present embodiment, a case will be described in which the reaction force device is applied to a synchro-type rocking chair that sinks the seat 9 later in conjunction with the backward tilting of the backrest 8. However, the applicable chair is not limited to the synchro-type rocking chair, and may be applied to, for example, a chair that tilts the backrest 8 backward without being interlocked with the seat 9.

  A leg-side fixing member (hereinafter referred to as a leg-side fixing member 1) as a base 1 is attached to the upper end of the chair pillar 10. To the leg-side fixing member 1, a seat receiving member (hereinafter referred to as a seat receiving member 2) as a swinging body 2 and a back support rod 11 are swingably connected by shafts 12 and 13, respectively. Further, the seat receiving member 2 and the back support rod 11 are swingably connected by a shaft 14. The hole of the leg-side fixing member 1 through which the shaft 13 connecting the leg-side fixing member 1 and the back support rod 11 passes is a long hole 1a. The seat receiving member 2 and the back support rod 11 are connected by a synchro link 15, and a gas spring 16 with a lock mechanism is provided between the lower end of the synchro link 15 and the leg-side fixing member 1. A shaft for connecting the synchro link 15 and the gas spring 16 and a shaft 13 for connecting the leg-side fixing member 1 and the back support rod 11 are arranged coaxially. The seat 9 is attached to the seat receiving member 2, and the backrest 8 is attached to the back support rod 11.

  The oscillating body 2 is a member that oscillates with respect to the base body 1 in conjunction with the backward tilting operation and the standing up operation of the backrest 8, and is a seat receiving member 2 in this embodiment. However, it is not limited to the seat receiving member 2, and for example, the back support rod 11 or the like may be used. Further, in other types of chairs, members other than the seat receiving member 2 and the back support rod 11 may be used as long as the members swing with respect to the base body 1 in conjunction with the backward tilting operation and the standing up motion of the backrest 8.

  The base body 1 is a member that supports the rocking body 2 in a swingable manner, and is the leg-side fixing member 1 in this embodiment. However, the leg side fixing member 1 is not limited. In addition, in other types of chairs, members other than the leg-side fixing member 1 may be used as long as the swinging body 2 is swingably supported.

  The spring 3 is a rod-like or plate-like spring, and in this embodiment, a rod-like spring (hereinafter referred to as a bar spring) is used. The bar spring may be a round bar or a square bar. In this embodiment, a round bar is used. For example, four bar springs 3 are provided. However, the number of the bar springs 3 is not limited to four, and may be two, three, or five or more as long as it is plural. The magnitude of the reaction force to be generated may be the same for all the bar springs 3, or may be changed for some or all of the bar springs 3. Examples of means for changing the magnitude of the reaction force to be generated include changing the material of the bar spring 3, changing the thickness, changing the length, changing the shape, and the like. In this embodiment, the length of all the bar springs 3 is made the same, and the magnitude of the reaction force generated for each bar spring 3 is changed by changing the thickness.

  The front end of the bar spring 3 is passed through a hole 17 a in a support wall 17 provided in the leg-side fixing member 1. The diameter of the hole 17a is slightly larger than the diameter of the bar spring 3, and can be shifted forward or backward as the seat receiving member 2 swings. In the present embodiment, a pair of left and right support walls 17 are provided in the leg-side fixing member 1, and the left and right support walls 17 each support two bar springs 3. A wall 18 is provided in front of the bar spring 3 to prevent the bar spring 3 from moving too far forward and coming off from the hole 17a. The rear end of the bar spring 3 is inserted into a hole 19 a of a spring receiver 19 attached to the seat receiving member 2. The diameter of the hole 19a is formed slightly larger than the diameter of the bar spring 3, and the angle can be changed as the seat receiving member 2 swings. The spring receiver 19 is, for example, screwed to the seat receiving member 2. In this embodiment, the four springs 19 are provided with four holes 19a to support the bar springs 3 together. However, it is not necessary to support all four bar springs 3 by one spring receiver 19, and a plurality of spring receivers 19 may be provided to support the four bar springs 3 in groups.

  The operation switching cam 6 is disposed between the support wall 17 and the spring receiver 19 so as to face the bar spring 3. In the present embodiment, the operation switching cam 6 is disposed in the vicinity of the support wall 17, and the operation switching cam 6 can be brought into contact with the vicinity of the support position on the front side of the bar spring 3. However, the position where the operation switching cam 6 abuts is not limited to the vicinity of the support position on the front side of the bar spring 3, and may be another position. The operation switching cam 6 is a rotating cam whose outer peripheral surface is a cam surface 6b. The operation switching cam 6 is attached to the operating device 7. A non-circular hole 6 a is provided at the center of the operation switching cam 6. By making the shape of the hole 6a non-circular, that is, a shape other than circular, the hole 6a rotates integrally with the pipe shaft 20 of the operating device 7 as described later.

  Here, the projecting position 4 is a rotational angle position (position of the operation switching cam 6 indicated by a two-dot chain line in FIG. 1) in contact with the bar spring 3 in a state where the seat receiving member 2 is not swinging, and a retracted position. Reference numeral 5 denotes a rotational angle position (position of the operation switching cam 6 shown by a solid line in FIG. 1) that does not contact the bar spring 3 unless the swing angle of the seat receiving member 2 is maximized. In the present embodiment, as shown in FIG. 5, the protruding position 4 or the retracted position 5 is set every 45 degrees of rotation, and has a total of eight switching angles P1 to P8. However, the number of switching angles is not limited to eight and may be other numbers. Further, the combination pattern of the protruding position 4 and the retracted position 5, that is, the shape of the cam surface 6b may be the same for all the operation switching cams 6, but may be different for all or some of the operation switching cams 6. In this embodiment, the shape of the cam surface 6b is made different in all the operation switching cams 6.

  The operating device 7 rotates the operation switching cam 6 to the protruding position 4 or the retracted position 5. In this embodiment, all the operation switching cams 6 are operated together by one operating device 7. However, it is not necessary to operate all the operation switching cams 6 together, and the operation switching cams 6 may be selected in order and operated separately. The number of operation devices 7 is not limited to one, and a plurality of operation devices 7 may be provided, and the grouped operation switching cams 6 may be operated by a dedicated operation device 7 for each group.

  For example, as shown in FIGS. 6 and 7, the operating device 7 is attached to the pipe shaft 20 into which the operation switching cam 6 is fitted, a center bolt 21 penetrating the pipe shaft 20, and the outer periphery of the pipe shaft 20. It comprises four collars 22, 23, 24, 25 for positioning the operation switching cam 6 and the cam index 26, and a grip 27 attached to the proximal end of the pipe shaft 20. The bolt head 21a of the center bolt 21 is provided with a reference mark 28 that serves as a mark for adjusting the reaction force adjustment position.

  The pipe shaft 20 is rotatable relative to the center bolt 21. The cross-sectional shape of the range in which the operation switching cam 6 of the pipe shaft 20 is fitted is a shape that matches the shape of the hole 6 a of the operation switching cam 6. In the present embodiment, two flat portions 20 a are formed on the outer peripheral surface so that the cross-sectional shape of the pipe shaft 20 matches the shape of the hole 6 a of the operation switching cam 6. Therefore, the operation switching cam 6 cannot rotate relative to the pipe shaft 20, and the rotation angles of the operation switching cam 6 and the pipe shaft 20 coincide. On the other hand, since the operation switching cam 6 can move in the axial direction of the pipe shaft 20 in the range where the flat portion 20a is formed, the operation switching cam 6 is fitted from the tip side of the pipe shaft 20 to a predetermined position. Can be moved. All the operation switching cams 6 are fitted into the pipe shaft 20 in a combined body with switching angles P1 to P8.

  The collars 22 to 25 are spacers that are positioned so that the operation switching cam 6 faces the corresponding bar spring 3. In the present embodiment, the four bar springs 3 are arranged in two on the left and right, so that the collars 22 to 25 are arranged so that the operation switching cam 6 is also arranged on the left and right in accordance with this. Is provided.

  The grip 27 is fitted into the proximal end of the pipe shaft 20 and is fixed by, for example, a set screw (not shown). Therefore, when the grip 27 is rotated, the pipe shaft 20 and the four operation switching cams 6 are rotated by the same angle with respect to the center bolt 21, and the operation switching cam 6 at the protruding position 4 and the operation switching cam 6 at the retracted position 5 are rotated. The reaction force adjustment position as a combination is switched. The grip 27 is disposed inside the bolt head 21 a of the center bolt 21. A position display 29 indicating a reaction force adjustment position is provided on the outer peripheral surface at the tip of the grip 27.

  The operating device 7 is attached to the base body 1. In the present embodiment, the right and left side plates 1b and 1c of the leg-side fixing member 1 as the base body 1 are inserted so as to bridge the operating device 7 with the holes, and the thread portion at the tip of the center bolt 21 protruding from the side plate 1c. The center bolt 21 is fixed to the base body 1 by screwing a round nut 30 and a hexagonal nut 31 into 21b. The collar 25 on the side plate 1c side has a larger diameter than the hole of the side plate 1c. Accordingly, the end face of the collar 25 comes into contact with the side plate 1b, and the operation switching cam 6 and the index 26 are positioned by the collars 22 to 25 with reference to the side plate 1b. The collar 22 on the grip 27 side contacts the end face of the grip 27.

  The operating device 7 has a plurality of reaction force adjustment positions in which the combination of the operation switching cam 6 displaced to the protruding position 4 and the operation switching cam 6 displaced to the retracted position 5 are different. The reaction force adjustment position is determined by the switching angles P1 to P8 of the operation switching cam 6. In this embodiment, since a total of eight switching angles P1 to P8 are provided for every 45 degrees of rotation angle, a total of eight reaction force adjustment positions A1 to A8 are also provided for every 45 degrees of rotation angle. That is, the rotation angle of the operating device 7 that sets the switching member 6 to the first switching angle P1 is the first reaction force adjustment position A1, and the rotation angle of the operating device 7 that sets the switching member 6 to the second switching angle P2 is. It becomes 2nd reaction force adjustment position A2. The same applies to the other reaction force adjustment positions A3 to A8. In the present embodiment, the protruding position 4 is such that the magnitude of the generated reaction force is such that the first reaction force adjustment position A1 <the second reaction force adjustment position A2 <... <the eighth reaction force adjustment position A8. The combination of the operation switching cam 6 and the operation switching cam 6 at the retracted position 5 is determined. However, it is not necessary to determine the magnitude of the reaction force in this way. For example, the first reaction force adjustment position A1> the second reaction force adjustment position A2> ...> the eighth reaction force adjustment position A8 may be used. Other orders may be used.

  Further, a position display 29 is attached so that the position display 29 representing the reaction force adjustment positions A1 to A8 matches the reference mark 28 when the operating device 7 is moved to each reaction force adjustment position A1 to A8. . The position display 29 may simply indicate the reaction force adjustment positions A1 to A8, but may simultaneously indicate the magnitude relationship of the reaction force. In the present embodiment, the reaction force adjustment positions A1 to A8 At the same time, the magnitude of reaction force is shown. The position display 29 includes, for example, characters such as numerals and alphabets, patterns representing the magnitude of reaction force in terms of number and size, and the like. In the present embodiment, numerals “1” to “8” are used as the position display 29, and “1” is opposed to the reference mark when the operating device 7 is moved to the first reaction force adjustment position A1, Each position display 29 is attached such that “2” faces the reference mark when moved to the reaction force adjustment position A2. The same applies to the other position indications 29.

  In the present embodiment, an alignment device 32 is provided to make it easier to align the operating device 7 with each of the reaction force adjustment positions A1 to A8. However, the alignment device 32 may be omitted. For example, as shown in FIGS. 8 and 9, the alignment device 32 includes a cam index 26 fitted into the pipe shaft 20 and rotated integrally therewith, and a ball plunger 33 attached to the side plate 1 b of the leg-side fixing member 1. It is configured.

  At the center of the cam index 26, a hole 26a having the same shape as the hole 6a of the operation switching cam 6 is provided. It is supposed to be. The cam index 26 is provided with recesses 26b corresponding to the reaction force adjustment positions A1 to A8. In the present embodiment, since eight reaction force adjustment positions A1 to A8 are set, eight concave portions 26b are formed on the same circumference. The ball plunger 33 is attached to a position that can be opposed to the recess 26b. When the recess 26b is positioned in front by the rotation of the cam index 26, the ball of the ball plunger 33 enters the recess 26b. That is, when the rotation angle of the cam index 26 coincides with the reaction force adjustment positions A1 to A8, the ball of the ball plunger 33 enters the recess 26b. Accordingly, a light force for stopping the rotation of the cam index 26 is generated, and it becomes easy to accurately adjust the operating device 7 to the reaction force adjustment positions A1 to A8.

  When the seat occupant tilts the backrest 8 in a state where the lock of the gas spring 16 is released, the back support rod 11 lowers the rear portion of the seat receiving member 2 while rotating around the shaft 14 (FIG. 1B). Thereby, the backrest 8 and the seat 9 are interlocked to change the angle. Further, since the seat receiving member 2 swings with respect to the leg-side fixing member 1, the reaction force device operates to generate a reaction force against the swing.

  The synchro link 15 is rotated by the swing of the seat receiving member 2, and the gas spring 16 is pressed and contracted. If the seated person locks the gas spring 16 and cannot expand or contract in a state where the backrest 8 is tilted to a desired angle, the seat receiving member 2 cannot swing with respect to the leg-side fixing member 1, and the back support rod Since 11 cannot rotate, the backrest 8 and the seat 9 are fixed at that angle.

  When the backrest 8 is raised, the gas spring 16 is unlocked while the seated person is not leaning against the backrest 8. The gas spring 16 can be expanded and contracted by the unlocking operation, and the seat receiving member 2 and the back support rod 11 can swing with respect to the leg-side fixing member 1, so that the seat receiving member is generated by the reaction force generated by the reaction force device. 2 and the back support rod 11 are interlocked and returned to their original positions, the backrest 8 is raised, and the seat 9 returns to the original position.

  Next, generation of reaction force of the reaction force device will be described. As shown by a solid line in FIG. 1B, when the operation switching cam 6 is moved to the retracted position 5, the bar spring 3 is not curved even if the swinging body 2 swings with respect to the base 1. Therefore, the bar spring 3 remains in an inoperative state and does not generate a reaction force. On the other hand, as shown by a two-dot chain line in FIG. 1B, when the operation switching cam 6 is moved to the projecting position 4, when the swinging body 2 swings with respect to the base 1, the operation switching cam 6 The bar spring 3 is bent. Therefore, the bar spring 3 is activated and generates a reaction force against swinging.

  The operating device 7 has eight reaction force adjustment positions. By switching the reaction force adjustment position by rotating the grip 27, the combination of the operation switching cams 6 moving to the protruding position 4 is changed. Therefore, the combination of the bar springs 3 that are in the operating state changes, and the magnitude of the reaction force that is generated can be adjusted. In this embodiment, since eight positions are provided as reaction force adjustment positions, the magnitude of the reaction force generated can be adjusted in eight stages.

  Since the reaction force is adjusted by rotating the grip 27 of the operating device 7 in this way, the reaction force adjustment work becomes easy. Further, since the switching cam 6 is rotationally displaced to switch between the protruding position 4 that contacts the bar spring 3 and the retracted position 5 that does not contact, the operating force necessary for adjusting the reaction force can be reduced. it can. For these reasons, the usability of the reaction force device can be improved.

  This reaction force device has a structure in which the operation / non-operation of the bar spring 3 is switched by the rotational displacement of the operation switching cam 6, and the structure can be simplified. Therefore, the manufacturing cost can be reduced and the apparatus can be reduced in size and weight.

  In this reaction force device, the bar spring 3 is thin and can be easily installed in a large number. By increasing the number of bar springs 3 installed, the reaction force can be adjusted in multiple stages. Therefore, a reaction force device suitable for performing fine reaction force adjustment can be provided. Further, since the operation switching cam 6 is not moved in the axial direction, it is easy to install a large number of operation switching cams 6. Therefore, a reaction force device suitable for performing fine reaction force adjustment can be provided.

  Further, since the position display 29 is provided on the operating device 7, the reaction force can be adjusted while confirming the position display 29. In addition, since the user of the chair remembers his / her favorite position, it becomes easy to set the reaction force value to his / her favorite when he / she uses a chair used by another person.

  The above-described embodiment is an example of a preferred embodiment of the present invention, but is not limited thereto, and various modifications can be made without departing from the scope of the present invention. For example, in the above description, when the swing angle of the seat receiving member 2 is maximized, the bar spring 3 is also in contact with the operation switching cam 6 in the retracted position 5, but it may not be in contact. Further, the swinging angle of the seat receiving member 2, that is, the backrest 8 of the seat receiving member 2, is ensured by causing the bar spring 3 to contact the operation switching cam 6 at the retracted position 5 immediately before the swinging angle of the seat receiving member 2 becomes maximum. A reaction force may be generated immediately before the rearward tilt angle is maximized so as to relieve the feeling of bottoming when the backrest 8 is tilted to the maximum.

  In the above description, the rotation cam as the operation switching cam 6 can be rotated one or more times in the same direction, that is, the first reaction force adjustment position → the second reaction force adjustment position →... → the eighth reaction force Adjustment position → First reaction force adjustment position → Second reaction force adjustment position →... Or First reaction force adjustment position → Eighth reaction force adjustment position → Seventh reaction force adjustment position →... → Second The reaction force adjustment position → the first reaction force adjustment position → the eighth reaction force adjustment position →... Can be operated, but the rotatable angle is set to less than 360 degrees, for example, the first reaction force adjustment position. -> Second reaction force adjustment position->-> seventh reaction force adjustment position-> eighth reaction force adjustment position-> seventh reaction force adjustment position->->-> operate to the first reaction force adjustment position May be.

  In the above description, the grip 27 is attached to the tip of the pipe shaft 20 of the operating device 7 and the pipe shaft 20 is directly rotated to switch the reaction force adjustment position. However, the grip 27 is provided at another position. Then, the reaction force adjustment position may be switched by indirectly rotating the pipe shaft 20. An example is shown in FIG. In this example, an operation lever 35 is provided on the armrest 34, and a grip 27 is provided at the tip of the operation lever 35. The rotation of the grip 27 is transmitted to the pipe shaft 20 via the torque wire 36. In this example, the grip 27 can be operated even if the seated person does not reach out. The operation lever 35 is also used for operating the lock mechanism of the gas spring 16. That is, when the operating lever 35 is swung upward, the locking control wire 37 is pulled to release the locking mechanism of the gas spring 16 and the backrest 8 can be locked (backward tilted). Then, when the operation lever 35 is swung downward, the locking control wire 37 is returned, the locking mechanism of the gas spring 16 is locked, and the backrest 8 is fixed.

  A reaction force device having four bar springs 3 was prototyped. A round bar-shaped bar spring 3 was used. The diameter of the first bar spring 3 is 6.5 mm, the diameter of the second bar spring 3 is 7.0 mm, the diameter of the third bar spring 3 is 8.0 mm, and the diameter of the fourth bar spring 3 is 5. It was 1 mm. The lengths of the four bar springs 3 were the same. The magnitude of the reaction force generated by each bar spring 3 is as follows: first bar spring 3; 196.1N (20 kgf), second bar spring 3; 294.2N (30 kgf), third bar spring 3; 392 3N (40 kgf), the fourth bar spring 3; 147.1 N (15 kgf). Four of the first bar spring 3, the fourth bar spring 3, the third bar spring 3, and the second bar spring 3 were arranged in this order from the side closer to the side plate 1b of the leg side fixing member 1.

  In addition, eight reaction force adjustment positions were set. A first operation switching cam 6 corresponding to the first bar spring 3 is shown in FIG. In FIG. 5, the switching angles P1 to P8 are indicated by radial two-dot chain lines. The cam shape was designed so that the projecting position 4 was reached at the first and fourth to eighth switching angles P1, P4 to P8, and the retracted position 5 was reached at the second and third switching angles P2 and P3. A second operation switching cam 6 corresponding to the second bar spring 3 is shown in FIG. At the second, fourth, seventh, and eighth switching angles P2, P4, P7, and P8, the projection position 4 is reached, and at the first, third, fifth, and sixth switching angles P1, P3, P5, and P6. The cam shape was designed to be at the retreat position 5. FIG. 5C shows the third operation switching cam 6 corresponding to the third bar spring 3. At the third, fifth, sixth, seventh, and eighth switching angles P3, P5, P6, P7, and P8, the projection position 4 is reached, and at the first, second, and fourth switching angles P1, P2, and P4. The cam shape was designed to be at the retreat position 5. A fourth operation switching cam 6 corresponding to the fourth bar spring 3 is shown in FIG. The cam shape was designed so that the projection position 4 was reached at the sixth and eighth switching angles P6 and P8, and the retracted position 5 was reached at the first to fifth and seventh switching angles P1 to P5 and P7.

  FIG. 11 shows the relationship between the reaction force adjustment positions A1 to A8, the bar spring 3 that is activated, and the magnitude of the reaction force that is generated. As is apparent from this figure, only the first bar spring 3 is operated at the first reaction force adjustment position A1, and a reaction force of 196.1 N (20 kgf) is generated. Further, only the second bar spring 3 is operated at the second reaction force adjustment position A2, and a reaction force of 294.2 N (30 kgf) is generated. Further, at the third reaction force adjustment position A3, only the third bar spring 3 operates, and a reaction force of 392.3N (40 kgf) is generated. In addition, at the fourth reaction force adjustment position A4, the first and second bar springs 3 are operated to generate a total reaction force of 490.3 N (50 kgf). Further, at the fifth reaction force adjustment position A5, the first and third bar springs 3 are operated, and a total reaction force of 588.4 N (60 kgf) is generated. In addition, at the sixth reaction force adjustment position A6, the first, third, and fourth bar springs 3 are operated to generate a total reaction force of 735.5 N (75 kgf). At the seventh reaction force adjustment position A7, the first, second, and third bar springs 3 are operated, and a total reaction force of 882.6 N (90 kgf) is generated. Further, at the eighth reaction force adjustment position A8, all the bar springs 3 are operated, and a total reaction force of 1030 N (105 kgf) is generated.

  By using the four bar springs 3 in this way, it was possible to adjust the reaction force in 8 steps every 98.07 N (10 kgf) or 147.1 N (15 kgf).

  A reaction force device using another bar spring 3 was prototyped with respect to the reaction force device of Example 1. That is, a reaction force device was prototyped using the same combination of the operation switching cams 6 as the reaction force device of Example 1 and the operation device 7. 12 and 13 show the reaction force device. In addition, the same code | symbol is attached | subjected to the member same as the reaction force apparatus of FIG. A bar spring 3 having a square bar shape with a cross-sectional shape of a square having a side of 7.5 mm was used. The lengths from the support wall 17 to the spring receiver 19 were the first bar spring 3; 220 mm, the second bar spring 3; 195 mm, the third bar spring 3; 186 mm, and the fourth bar spring 3; 220 mm. . The magnitude of the reaction force generated by each bar spring 3 is as follows: first bar spring 3; 196.1N (20 kgf), second bar spring 3; 343.2N (35 kgf), third bar spring 3; 392 3N (40 kgf), fourth bar spring 3; 196.1 N (20 kgf). Four of the first bar spring 3, the fourth bar spring 3, the third bar spring 3, and the second bar spring 3 were arranged in this order from the side closer to the side plate 1b of the leg side fixing member 1.

  FIG. 14 shows the relationship between the reaction force adjustment positions A1 to A8, the bar spring 3 that is activated, and the magnitude of the reaction force that is generated. As is apparent from this figure, only the first bar spring 3 is operated at the first reaction force adjustment position A1, and a reaction force of 196.1 N (20 kgf) is generated. At the second reaction force adjustment position A2, only the second bar spring 3 operates, and a reaction force of 343.2 N (35 kgf) is generated. Further, at the third reaction force adjustment position A3, only the third bar spring 3 operates, and a reaction force of 392.3N (40 kgf) is generated. In addition, at the fourth reaction force adjustment position A4, the first and second bar springs 3 are operated to generate a total reaction force of 539.4 N (55 kgf). Further, at the fifth reaction force adjustment position A5, the first and third bar springs 3 are operated, and a total reaction force of 588.4 N (60 kgf) is generated. In addition, at the sixth reaction force adjustment position A6, the first, third, and fourth bar springs 3 are operated to generate a total reaction force of 784.5 N (80 kgf). In addition, at the seventh reaction force adjustment position A7, the first, second, and third bar springs 3 are operated to generate a total reaction force of 931.6 N (95 kgf). Further, at the eighth reaction force adjustment position A8, all the bar springs 3 are operated, and a total reaction force of 1128 N (115 kgf) is generated.

  By using the four bar springs 3 in this way, eight stages of reaction force adjustment could be performed.

An example of embodiment of the reaction force device of the chair of the present invention is shown, (A) is a sectional view of a base and an oscillating body which shows the mode of a spring in the state where the oscillating body is not oscillating, and (B). It is sectional drawing of a base | substrate and a rocking | swiveling body which show the mode of the spring in the state where the rocking | swiveling body rock | fluctuated horizontally. It is sectional drawing of the base | substrate and rocking | fluctuation body which shows the same reaction force apparatus and shows the mode of a spring from an upper direction. It is a side view of a chair provided with the reaction force device. It is a front view of a chair provided with the reaction force device. The operation switching cam is shown, (A) is a front view of the first operation switching cam, (B) is a front view of the second operation switching cam, (C) is a front view of the third operation switching cam, (D ) Is a front view of a fourth operation switching cam. It is an exploded view of the operating device. It is sectional drawing which shows the attachment state of the grip of an operating device. It is sectional drawing of an alignment apparatus. It is a front view which shows the cam index of a position alignment apparatus. It is a figure which cuts off and shows other embodiment of an operating device partially. It is a figure which shows the relationship between the reaction force adjustment position of Example 1, the magnitude | size of the reaction force to generate | occur | produce, and the bar spring which becomes an operation state. It is sectional drawing of the base | substrate which shows other embodiment of the reaction force apparatus of this invention, and shows the mode of the spring in the state where the rocking body is not rocking | swiveling from a horizontal direction. It is sectional drawing of the base | substrate and rocking body which show other embodiment of the reaction force apparatus of this invention, and show the mode of a spring from an upper direction. It is a figure which shows the relationship between the reaction force adjustment position of Example 2, the magnitude | size of the reaction force which generate | occur | produces the bar spring which becomes an operation state. A conventional reaction force device is shown, (A) is a cross-sectional view in a state where the backrest is not inclined backward, and (B) is a cross-sectional view in a state where the backrest is inclined backward. It is sectional drawing which shows the other conventional reaction force apparatus. It is sectional drawing which follows the VI-VI line of FIG. It is sectional drawing which follows the VII-VII line of FIG. It is an expanded view of the cam surface of a cylindrical cam.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base body 2 Oscillator 3 Bar spring 4 Projection position 5 Retraction position 6 Operation switching cam 6b Cam surface 7 Operating device 29 Position display A1 to A8 Reaction force adjustment position

Claims (4)

  A plurality of rod or plate springs provided between a base body and a rocking body connected to the base body, and a protruding position where the cam surface abuts on the corresponding spring and the cam surface are provided for each spring. An operation switching cam that can be rotationally displaced between a retracted position that is farther from the corresponding spring than the corresponding projecting position; and an operation device that rotationally displaces the operation switching cam. The cam surface has a plurality of reaction force adjustment positions in which the combination of the operation switching cam displaced to the protruding position and the operation switching cam displaced to the retracted position is different. The chair reaction force device characterized in that the displaced operation switching cam bends a corresponding spring according to the swing of the swinging body to generate a reaction force against the swing.   The chair reaction force device according to claim 1, wherein the operation device is provided with a position display indicating the reaction force adjustment position.   The chair reaction force device according to claim 1, wherein the plurality of springs have different lengths.   The chair reaction force device according to claim 1, wherein the plurality of springs have different thicknesses.

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