JP2020022726A - Chair and chair manufacturing method - Google Patents

Abstract

To provide a chair whose seat part is inclined in every direction and whose sitting comfort is stable.SOLUTION: A chair has: a seat part 10; and four leg parts 11 which are connected to the seat part 10 below the seat part 10 and in contact with the ground surface. The seat part 10 has an upper side seat part 13 and a lower side seat part 14 positioned below the upper side seat part with intervals. Between the upper side seat part 13 and the lower side seat part 14, four unequal pitch springs 15 and constant pitch springs 16 are provided. Property of the unequal pitch springs 15 is that there are a narrow pitch area to be a first spring constant and a wide pitch area to be a second spring constant greater than the first spring constant. In the state that a person is seated without tilting the upper side seat part 13, setting is performed so that for an assumed user of lowest body weight, balance is achieved in the narrow pitch area and for an assumed user of heaviest body weight, balance is achieved in the wide pitch area.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a chair whose seat surface is inclined in all directions and a method of manufacturing the chair.

  Patent Literature 1 discloses a chair in which a seating surface is inclined in all directions in order to suppress a burden on a waist or the like due to the same posture continuing for a long time. Patent Literature 1 discloses a chair provided with a seating portion on which a seated person sits and a seating receiving portion for supporting the seating portion from below, and a waveform coil spring is provided between the seating portion and the seating receiving portion, and a waveform is provided. The seating surface is inclined in an arbitrary direction by inclining the seating portion by bending of the coil spring. Further, a tilting range restricting means is provided so that the seating portion is not tilted excessively, so that the seating portion does not tilt beyond a predetermined angle.

  Patent Literature 2 discloses a chair having a seat and a column connected to the seat, in which the column is tilted in an arbitrary direction so that the seat is tilted. ing. It is described that the support is tilted by a link mechanism, and an equal pitch spring disposed around the support is used to return the tilt. In the chair of Patent Literature 2, the range of inclination is regulated by the link mechanism.

JP 2007-268118 A JP 2015-192825 A

  However, in the conventional chair in which the seat tilts, it is necessary to provide a means for suppressing the seat from being tilted too much, and there has been a problem that the cost increases. In addition, there is a problem that the inclination of the seat portion varies depending on the weight of the seated person, and the sitting comfort varies depending on the person.

  Therefore, an object of the present invention is to reduce the cost of a chair in which a seat tilts in all directions and stabilize the sitting comfort.

  The present invention provides an upper seat portion having an upper portion serving as a seat, a lower seat portion located below the upper seat portion, and three or more coaxially arranged between the upper seat portion and the lower seat portion. An unequal-pitch spring, and a leg connected to the lower seat below the lower seat, wherein the unequal-pitch spring is disposed at a vertex position of a polygon, and has a first spring constant. , And a wide pitch region having a second spring constant larger in pitch than the narrow pitch region and having a larger spring constant than the first spring constant. Is set so that it does not extend beyond the installation length, with the uncompressed state as the installation length, and is narrow for the minimum weight person who is supposed to use it when the person is seated without tilting the upper seat. Balance in the pitch area, and use the wide pitch area for those who are Fit as have been set, the minimum weight, 25～35Kg, best weight is 100～120Kg, a chair, characterized in that.

  Further, the present invention includes a seat portion having an upper portion as a seating surface, a pedestal portion located below the seating portion, and a support portion connecting the seat portion and the pedestal portion, and the pedestal portion has a supporting portion. An upper pedestal to be connected, a lower pedestal located below the upper pedestal, and three or more unequal pitch springs coaxially arranged between the upper pedestal and the lower pedestal. The unequal-pitch springs are arranged so as to be located at the vertices of the polygon, and have a narrow pitch region as a first spring constant, a pitch wider than the narrow pitch region, and a spring constant larger than the first spring constant. A wide pitch region having a second spring constant is set, the narrow pitch region is compressed, and the wide pitch region is set so that the uncompressed state is set as an attachment length so as not to extend beyond the attachment length, and the support portion is inclined. When the person sits down without using it, a narrow pitch It is set to be balanced in a wide pitch area for a person with the highest weight that is assumed to be balanced and used in the area, the minimum weight is 25 to 35 kg, and the maximum weight is 100 to 120 kg. It is a chair.

  The present invention also provides an upper seat having an upper portion as a seat, a lower seat located below the upper seat, and three or more coaxially arranged between the upper seat and the lower seat. And a leg connected to the lower seat below the lower seat, a method for manufacturing a chair, wherein the unequal pitch spring is located at a vertex position of a polygon. A narrow pitch region having a narrow pitch region as a first spring constant, and a wide pitch region as a second spring constant having a wider pitch than the narrow pitch region and a higher spring constant than the first spring constant. Compressed, set the uncompressed state of the wide pitch area as the installation length, so that it does not extend beyond the installation length, and in a state where a person is seated without tilting the upper seat, the minimum weight assumed to be used For those who are balanced in a narrow pitch area, Is to be set so as to balance a wide pitch region is a method of manufacturing a chair, characterized in that.

  Further, the present invention includes a seat portion having an upper portion serving as a seating surface, a pedestal portion located below the seating portion, and a support portion connecting the seat portion to the pedestal portion, and the pedestal portion is connected to the supporting portion. A chair having an upper pedestal portion, a lower pedestal portion located below the upper pedestal portion, and three or more unequal pitch springs coaxially arranged between the upper pedestal portion and the lower pedestal portion. Wherein the unequal pitch springs are arranged at the vertices of the polygon, and the first spring constant is a narrow pitch region, and the pitch is wider than the narrow pitch region, and the first spring constant is higher than the first spring constant. And a wide pitch region having a large spring constant as a second spring constant, wherein the narrow pitch region is compressed, and the wide pitch region is set so that the uncompressed state is the mounting length and does not extend beyond the mounting length. , In a state where a person is seated without tilting the support, Set so as to balance a wide pitch regions for human highest weight to assume the balance, use a narrow pitch region for a chair manufacturing method characterized by.

  In the present invention, the first spring constant of the unequal-pitch spring arranged behind the chair is set to be larger than the first spring constant of the unequal-pitch spring arranged in front and smaller than the second spring constant. The second spring constant of the unequal pitch spring disposed behind the chair may be set to be larger than the second spring constant of the unequal pitch spring disposed in front of the chair. The seat surface is less likely to tilt rearward, and safety can be improved.

  In the present invention, the deflection from the first spring constant of the unequal pitch spring disposed at the rear of the chair to the second spring constant changes from the first spring constant of the unequal pitch spring disposed at the front of the chair. The seating surface, which is set to be smaller than the deflection before changing to the two spring constants, is less likely to tilt rearward, and safety can be improved.

  ADVANTAGE OF THE INVENTION According to this invention, the chair which a seat part inclines in every direction can be implement | achieved at low cost, and also a sitting comfort can be stabilized.

The figure which showed the structure of the chair of Example 1. The figure which showed the structure of the seat part 10. The figure which showed the structure of the seat part 10. 4 is a graph showing spring characteristics. The figure which showed the operation | movement at the time of sitting without inclining the seat surface S. 4 is a graph showing spring characteristics. 4 is a graph showing spring characteristics. The figure which showed the operation | movement at the time of inclining with the seat surface S inclined. 7 is a graph showing the spring characteristics when inclined. 7 is a graph showing the spring characteristics when inclined. 7 is a graph showing the spring characteristics when inclined. The figure which showed the structure of the chair of Example 2. The figure which showed the structure of the pedestal part 21. The figure which showed the structure of the pedestal part 21.

  Hereinafter, specific embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments.

  FIG. 1 is a diagram illustrating a configuration of the chair according to the first embodiment. As shown in FIG. 1, the chair according to the first embodiment includes a seat 10 having a seat S that contacts a person, and four legs that are connected to the seat 10 below the seat 10 and that contact the floor. 11 and a backrest 12 connected to the seat 10.

  As shown in FIG. 2, the seat 10 has an upper seat 13 and a lower seat 14 positioned below the upper seat 13 with an interval therebetween. The upper seat portion 13 and the lower seat portion 14 have a substantially square plate shape, and are arranged such that their main surfaces are parallel to each other. A seat surface S is connected to an upper portion of the upper seat portion 13. The backrest 12 is connected to one side of the square of the upper seat 13 at an angle. Also, four legs 11 are connected to the lower surface of the lower seat 14. In addition, between the upper seat 13 and the lower seat 14, four unequal pitch springs 15 and an equal pitch spring 16 are provided, so that the upper seat 13 and the lower seat 14 are connected. It is connected.

  The unequal-pitch springs 15 and the equal-pitch springs 16 are arranged coaxially so that their axes are perpendicular to the main surfaces of the upper seat 13 and the lower seat 14. Further, as shown in FIG. 3, the four unequal-pitch springs 15 are arranged so as to be located at the vertices of a square. Also, two unequal pitch springs 15 are arranged on each of the front side and the back side. The equal pitch springs 16 are arranged at the center of the circumference formed by the four unequal pitch springs 15. Of the four unequal pitch springs 15, the unequal pitch spring 15 disposed in front of the chair (the side opposite to the backrest 12 side) is referred to as 15A, and the unequal pitch spring 15 disposed behind is referred to as 15B. I do.

  The unequal-pitch spring 15 is a coil spring having a non-linear characteristic in which the pitch is not constant but changes while keeping the coil diameter and the wire diameter constant. In two stages of a wide and wide pitch region. The characteristics of the unequal pitch spring 15 include a small spring constant (first spring constant) in a narrow pitch region and a spring constant (second spring constant) larger than the first spring constant in a wide pitch region.

  A shaft 17 is passed through the center of the unequal pitch spring 15, and the shaft 17 passes through the upper seat portion 13 and the lower seat portion 14, respectively. One end of the shaft 17 on the upper seat 13 side is fixed to the upper seat 13 by a bolt 18. One end of the shaft 17 on the lower seat portion 14 side is not fixed to the lower seat portion 14 but protrudes from a hole provided in the lower seat portion 14. A ring 19 is connected to the protruding end. With the shaft 17, the bolt 18, and the ring 19, when a person is not seated, the unequal pitch spring 15 is set in a state of being compressed in a region of the first spring constant. That is, the mounting length of the unequal pitch spring 15 is set in this manner. Further, since one end of the shaft 17 on the lower seat portion 14 side is not fixed, the upper seat portion 13 can be inclined by compression and expansion of the unequal pitch spring 15. The ring 19 prevents the unequal-pitch spring 15 from extending beyond its installation length. In this manner, the unequal-pitch spring 15 is compressed in the region of the first spring constant (narrow pitch region), and the region of the second spring constant (wide pitch region) is uncompressed as the mounting length. By setting the spring so that it does not stretch more, the rattling of the seat surface S is prevented.

  The characteristics of the unequal pitch spring 15 are set as follows. In a state where a person is seated without tilting the upper seat portion 13, that is, in a case where the upper seat portion 13 and the lower seat portion 14 are seated in parallel with each other, a person having the minimum weight to use is considered The balance is set so as to be balanced in the region of one spring constant (narrow pitch region) and to be balanced in the region of the second spring constant (wide pitch region) for the person with the highest weight to be used. Here, the minimum weight is, for example, 25 to 35 kg, and the maximum weight is, for example, 100 to 120 kg. The load at the change point where the first spring constant changes to the second spring constant may be between the minimum weight and the maximum weight, and is set to, for example, a load of 40 to 60 kg.

  The equal-pitch spring 16 is a coil spring having linear characteristics in which the coil diameter, wire diameter, and pitch are all constant. When a person is seated, the equal pitch spring 16 is compressed or bent vertically depending on the load position. Thereby, it is possible to adjust the load applied to the unequal pitch spring 15 when a person is seated, adjust the load required for tilting the seat surface S, adjust the maximum tilt angle, and adjust the sitting comfort. it can.

  The characteristics of the entire spring including the unequal pitch spring 15 and the equal pitch spring 16 are, for example, a first spring constant of 3 to 8 kgf / mm and a second spring constant of 12 to 17 kgf / mm.

  FIG. 4 is a graph showing an example of the characteristics of the unequal pitch spring 15 and the equal pitch spring 16. The graph shows three characteristics of the combined characteristics of the four unequal-pitch springs 15, the characteristics of the equal-pitch springs 16, and the combined characteristics of the four unequal-pitch springs 15 and the equal-pitch springs 16 as a whole. I have. The horizontal axis of the graph is the length (mm) of the spring, and the vertical axis is the load (kg). The natural lengths of the unequal pitch springs 15 and 16 are 65 mm, the attachment length is 62 mm, and the close contact length is 43 mm. The overall characteristics of the four unequal pitch springs 15 and the equal pitch springs 16 include a first spring constant of 6 kgf / mm, a second spring constant of 15 kgf / mm, and a load at a change point of the spring constant. 55 kg.

  Next, the operation of the chair according to the first embodiment will be described. First, a case where a person sits down without tilting the seating surface S will be described. In this case, as shown in FIG. 5, the interval between the upper seat portion 13 and the lower seat portion 14 is reduced by compressing the unequal pitch springs 15 and the equal pitch springs 16 according to the load at the time of seating, The seat S sinks.

  Here, the characteristics of the unequal pitch spring 15 are balanced in the region of the first spring constant (narrow pitch region) for a person having the lowest weight to be used, and for a person having the highest weight to be used. It is set so as to be balanced in the region of the second spring constant (wide pitch region). That is, in the case of a person having the minimum weight, the narrow pitch region of the unequal pitch spring 15 is compressed, and the wide pitch region is hardly compressed. In the case of a person having the highest weight, the narrow pitch region of the unequal pitch spring 15 is in close contact, and the wide pitch region is compressed. With this setting, even a person with a light weight sinks the seating surface S to give a cushioning property, and gives an impression of comfortable sitting. Further, even in the case of a person with a heavy weight, the sink width of the seat surface S is relatively small, giving an impression that the sitting comfort is good. That is, sitting comfort is good regardless of weight.

  The case where the overall spring characteristic of the unequal pitch spring 15 and the equal pitch spring 16 together is the characteristic shown in the graph of FIG. 4 will be specifically described by way of example. As shown in the graph of FIG. 4, when a person weighing 50 kg sits, the spring is compressed by 4 mm, and when a person weighing 100 kg sits, the spring is compressed by 8 mm. The difference in compression length is 6 mm. As described above, by using the unequal pitch spring 15, the difference in the compression length is reduced, and a comfortable chair can be realized regardless of the weight.

  FIG. 6 is a graph showing characteristics in a case where an equal pitch spring is used instead of the unequal pitch spring 15 and the spring constant of the entire spring is constant at a first spring constant value of 6 kgf / mm. As shown in FIG. 6, when a person weighing 50 kg is seated, the spring is compressed by 4 mm, and when a person weighing 100 kg is seated, the spring is compressed by 11.5 mm. The difference in compression length is 9.5 mm. In this way, the difference in the compression length is larger than in the case of FIG. 4, and a person with a heavy weight has a larger sinking width of the seating surface S. Therefore, the sitting comfort changes depending on the weight.

  FIG. 7 is a graph showing characteristics in a case where an equal pitch spring is used in place of the unequal pitch spring 15 and the spring constant of the entire spring is constant at a second spring constant value of 15 kgf / mm. As shown in FIG. 7, when a person weighing 50 kg sits, the spring is compressed by 0.2 mm, and when a person weighing 100 kg sits, the spring is compressed by 3.7 mm. The difference in compression length is 3.5 mm. Thus, in the case of FIG. 7, although the difference in the compression length is small, the compression of the spring when the person weighing 50 kg is seated is 0.2 mm, and there is almost no cushioning. That is, the sitting comfort of a person with a light weight deteriorates.

  Next, a case where the seat surface S is inclined will be described. In the chair of the first embodiment, by shifting the position of the center of gravity when a person is seated in a direction in which the load is to be inclined, the seat surface S can be inclined in the direction in which the load is shifted. As shown in FIG. 8, the unequal-pitch spring 15 on the side in which the load is shifted is compressed, and the upper seat portion 13 is inclined, whereby the seat surface S is inclined. The unequal pitch spring 15 on the side opposite to the direction in which the load is applied returns to the mounting length, but does not extend beyond the mounting length because the shaft 17, the bolt 18, and the ring 19 are provided.

  Here, the characteristics of the unequal pitch spring 15 are balanced in the region of the first spring constant (narrow pitch region) for a person with the lowest weight that is assumed to be used, and for a person with the highest weight that is assumed to be used. It is set so as to be balanced in the region of the second spring constant (wide pitch region). Therefore, even for a person of any weight, the load required to incline as the inclination angle of the seating surface S increases as the inclination angle of the seat surface S increases, and at a predetermined inclination angle, the load applied by the seated person increases. The inclination of the seat surface S is stopped in balance. Therefore, it is easy to set the inclination angle of the seat surface S to a desired state. Further, when the inclination angle of the seating surface S is small, the range in which the unequal pitch spring 15 is compressed without a load is narrow, and the wobble at the start of the inclination is reduced.

  The reason for such an operation will be described more specifically with reference to the graphs in FIGS. FIG. 9 shows a case where the characteristics of the unequal pitch springs 15 and the equal pitch springs 16 are set as shown in FIG. 4, and the compression is performed when the seat surface S is inclined forward of the chair (see FIG. 3). 6 is a graph showing the relationship between the length of the unequal pitch spring 15A and the load applied to the bearing surface S. FIG. 10 shows a case where the unequal pitch spring 15 is replaced with an equal pitch spring and the spring constant is set as shown in FIG. 6 (that is, the case where the spring constant is the equal pitch spring having the first spring constant). It is the graph which showed the relationship between the length of a spring, and the load at the time of compressing the equal pitch spring arrange | positioned in front of a chair. FIG. 11 shows a case where the unequal-pitch spring 15 is replaced with an equal-pitch spring, and when the spring constant is set as shown in FIG. 5 is a graph showing the relationship of FIG. The weight of the seated person was 35 kg and 102 kg.

  First, a case where a person lighter in weight than the load (55 kg) at the changing point of the unequal pitch spring 15 is seated will be described. When a person with a light weight sits, the unequal pitch spring 15 compresses the narrow pitch region and does not compress the wide pitch region. Therefore, when a light weight person tilts the seating surface S, when the tilt angle is small, the unequal pitch spring 15A on the tilt side (front of the chair) is compressed by the load, but the unequal pitch spring 15A on the opposite side to the tilt side is compressed. The pitch spring 15B generates a restoring force when trying to return to the mounting length. Since the restoring force is a force for returning the narrow pitch region to the original position, the restoring force is equal to the force required to compress the unequal pitch spring 15A on the inclined side. Therefore, the unequal pitch spring 15A on the inclined side is compressed with almost no load.

  When the inclination increases and the inclination angle reaches a certain value, the unequal-pitch spring 15B returns to the installation length and does not extend any further, so that the restoring force is lost. Therefore, since the unequal pitch spring 15A is compressed only by the load, the compression length of the unequal pitch spring 15A on the inclined side with respect to the load becomes linear. As shown in FIG. 9, when the body weight is 35 kg, the spring is compressed without load in a section of 2 mm in which the spring length of the unequal pitch spring 15A is from 60 mm to 58 mm. Is approximately linear. That is, as the inclination angle of the seat surface S increases, the load required to incline the seat surface S also increases. In this state, the inclination of the seat surface S stops when the load is balanced. Therefore, the inclination angle of the seat surface S can be easily controlled based on the shift amount of the center of gravity of the seated person.

  Further, since the weight of the seated person is light, the compression length of the unequal pitch spring 15B is also short. Therefore, the section where the restoring force of the unequal pitch spring 15B is lost is also short, and the section compressed without load is also short, so that the wobble feeling when the inclination angle of the seat surface S is small is reduced.

  Next, a case where a person whose weight is heavier than the load (55 kg) at the changing point of the unequal pitch spring 15 will be described. When a person with a heavy weight is seated, the unequal pitch spring 15 is compressed until the narrow pitch region comes into close contact, and the wide pitch region is also compressed. Therefore, when a person with a heavy weight tilts the seating surface S, the following operation is performed according to the tilt angle.

  When the inclination angle is small, the unequal pitch spring 15A on the inclined side (front of the chair) is compressed by the load, but the unequal pitch spring 15B on the opposite side to the inclined side attempts to return to the mounting length, and a restoring force is generated. This restoring force is a force for returning the wide pitch region to the original position, and is therefore equal to the force required to compress the wide pitch region of the unequal pitch spring 15A on the inclined side. Therefore, the unequal pitch spring 15A on the inclined side is compressed with almost no load. As shown in FIG. 9, when the weight is 102 kg, the unequal pitch spring 15A is compressed without a load because the unequal pitch spring 15A has a spring length of 3 mm from 54 mm to 51 mm (section in FIG. 9). A).

  When the inclination angle becomes larger, the wide pitch area of the unequal pitch spring 15B returns to the original length, and then the narrow pitch area attempts to return to the original. Since the restoring force is a force for returning the narrow pitch region to the original position, the restoring force is smaller than the force required for compressing the wide pitch region of the unequal pitch spring 15A. Therefore, the load on the unequal pitch spring 15A is not canceled out by the restoring force of the unequal pitch spring 15B, and the compression length of the unequal pitch spring 15A on the inclined side becomes linear with respect to the load. As shown in FIG. 9, when the weight is 102 kg, such a linear section is a section in which the spring length of the unequal pitch spring 15A is from 51 mm to 46 mm (section B in FIG. 9). In this section, the load required for inclining as the inclination angle of the seat surface S increases becomes large. In this state, the inclination of the seat surface S stops when the load is balanced. Therefore, the inclination angle of the seat surface S can be easily controlled based on the shift amount of the center of gravity of the seated person.

  When the inclination angle is further increased, the unequal-pitch spring 15B returns to the mounting length and does not extend any further, so that the restoring force is lost. Since the unequal pitch spring 15A is compressed only by the load, the unequal pitch spring 15A on the inclined side is also compressed as the load increases. As shown in FIG. 9, when the weight is 102 kg, the unequal pitch spring 15A is a section in which the spring length is 46 mm or less (section C in FIG. 9). In this section C, similarly to the section B, the inclination of the seat surface S is stopped when the load is balanced, so that the inclination angle of the seat surface S can be easily controlled by the shift amount of the center of gravity of the seated person. In this section C, the load required for tilting is larger than in section B. Therefore, in the section C, the seating surface S is less likely to be inclined than in the section B, and the seating surface S is also prevented from being excessively inclined.

  FIG. 10 shows a case where the unequal-pitch spring 15 is replaced with an equal-pitch spring, and when the spring constant is set as shown in FIG. 6 is a graph showing the relationship between the load and the load. The weight of the seated person was 35 kg and 102 kg.

  As shown in FIG. 10, when the weight of the seated person is 35 kg, the length compressed without load is 2 mm, which is the same as that in FIG. On the other hand, when the weight of the seated person is 102 kg, the section compressed without load is longer than that in the case of FIG. Therefore, wobbling when the seating surface S is tilted is large, and it is difficult to set the tilting angle of the seating surface S to a desired state. The section that is compressed without a load becomes longer than that in the case of FIG. 9 because the constant-pitch spring is used instead of the unequal-pitch spring, so that the restoring force becomes constant.

  FIG. 11 shows a case where the unequal-pitch spring 15 is replaced with an equal-pitch spring, and when the spring constant is set as shown in FIG. 5 is a graph showing the relationship of FIG. The weight of the seated person was 35 kg and 102 kg.

  As shown in FIG. 11, when the weight of the seated person is 35 kg, the length compressed without a load is 2 mm, which is the same as that in FIG. On the other hand, when the weight of the seated person is 102 kg, the length of compression without load is longer than in the case of FIG. Therefore, when the seating surface S is tilted, the wobbling feeling is large, and it is difficult to set the tilting angle of the seating surface S to a desired state. The section that is compressed without a load becomes longer than that in the case of FIG. 9 because the constant-pitch spring is used instead of the unequal-pitch spring, so that the restoring force becomes constant.

  As shown in FIGS. 9 to 11, the use of the unequal-pitch spring 15 changes the restoring force of the unequal-pitch spring 15B on the side opposite to the inclined side. It is no longer countered. As a result, the section compressed without load when a person with a heavy weight sits can be shortened, and the section in which the unequal pitch spring 15A is also compressed as the load increases can be lengthened instead.

  In the first embodiment, the pitch of the unequal pitch spring 15 is changed in two steps. However, the pitch may be changed in three or more steps or may be changed continuously. It is possible to realize an appropriate inclination angle of the seating surface S and a comfortable sitting according to the weight. However, in order to make the seated person more clearly recognize that the seating surface S is inclined, the pitch change is preferably stepwise, and preferably not more than three steps.

  In the first embodiment, the seat 10 is supported by the legs 11, but any structure conventionally used as long as the structure supports the seat 10 upward can be adopted. For example, a structure having a support such as one gas cylinder and a plurality of legs with casters radially extending from one end below the support may be employed.

  As described above, in the chair according to the first embodiment, the unequal-pitch spring 15 set to a predetermined characteristic is used to tilt the seating surface S. Therefore, stable sitting comfort can be realized regardless of the weight. Further, since the load required to incline as the inclination angle of the seating surface S increases, the seating surface S is prevented from wobbling and becoming unstable, and the inclination angle of the seating surface S is set to a desired value. It is easy to be in a state. In the chair according to the first embodiment, the maximum inclination angle of the seat surface S is determined by the characteristics of the unequal pitch spring 15, and it is not necessary to provide any other inclination angle limiting means. Therefore, the cost of the chair in which the seating surface S is inclined in all directions can be reduced.

  FIG. 12 is a diagram illustrating the configuration of the chair according to the second embodiment. As shown in FIG. 12, the chair according to the second embodiment includes a seat portion 20, a pedestal portion 21 located below the seat portion 20 and in contact with a floor surface, and a support portion connecting the seat portion 20 and the pedestal portion 21. 22.

  The seat portion 20 is a roughly disk-shaped member having a cushioning property, and an upper surface is a seat surface S. A support section 22 is connected to a lower surface of the seat section 20. The support portion 22 has a columnar shape and is supported such that its axis is in a vertical direction. For example, the height of the seat portion 20 may be variable by using a gas cylinder. The support portion is not limited to the shaft shape, and may have any structure as long as it is provided between the seat portion 20 and the pedestal portion 21 and supports the seat portion 20.

  As shown in FIG. 13, the pedestal portion 21 has an upper pedestal portion 23 and a lower pedestal portion 24 located below the upper pedestal portion 23 with a space therebetween. The upper pedestal portion 23 and the lower pedestal portion 24 have a substantially circular plate shape, and are arranged such that their main surfaces are parallel to each other. The support part 22 is connected to the upper part of the upper pedestal part 23. The lower surface of the lower seat portion 14 contacts the floor surface. Further, between the upper pedestal portion 23 and the lower pedestal portion 24, four unequal-pitch springs 25 and an equal-pitch spring 26 are provided, whereby the upper pedestal portion 23 and the lower pedestal portion 24 are connected. It is connected.

  The unequal-pitch spring 25 has a non-linear characteristic in which the pitch changes in two steps to a narrow-pitch region and a wide-pitch region wider than the narrow-pitch region, similarly to the unequal-pitch spring 15 of the first embodiment. It is a spring. The characteristics of the unequal pitch spring 25 include a small spring constant (first spring constant) in a narrow pitch region and a large spring constant (second spring constant) in a wide pitch region.

  A shaft 27 is passed through the center of the unequal pitch spring 25, and the shaft 27 passes through the upper pedestal portion 23 and the lower pedestal portion 24, respectively. One end of the shaft 27 on the lower pedestal portion 24 side is fixed to the lower pedestal portion 24 by a bolt 28. One end of the shaft 27 on the upper pedestal portion 23 side is not fixed to the upper pedestal portion 23 but protrudes from a hole provided in the upper pedestal portion 23. A ring 29 is connected to the protruding end. When the person is not seated, the unequal pitch spring 25 is compressed by the shaft 27, the bolt 28, and the ring 29 in the region of the first spring constant (narrow pitch region) and is compressed in the region of the second spring constant (wide region). Pitch area) is set in an uncompressed state. That is, the mounting length of the unequal pitch spring 25 is set in this manner. Further, since one end of the shaft 27 on the upper pedestal portion 23 side is not fixed, the upper pedestal portion 23 can be inclined by compression and expansion of the unequal pitch spring 25. Also, the ring 29 prevents the unequal pitch spring 25 from extending beyond its mounting length.

  The arrangement of the unequal pitch springs 25 and the equal pitch springs 26 is the same as in the first embodiment. That is, as shown in FIG. 14, the unequal-pitch springs 15 and the equal-pitch springs 16 are coaxially arranged such that their axes are perpendicular to the main surfaces of the upper pedestal portion 23 and the lower pedestal portion 24. In addition, as shown in FIG. 7, the four unequal-pitch springs 25 are arranged at each vertex position of the square. The equal pitch spring 26 is arranged at the center of the circumference formed by the four unequal pitch springs 25.

  The characteristics of the unequal pitch spring 25 are set in the same manner as the unequal pitch spring 15. In other words, in a state where a person is seated without tilting the upper pedestal portion 23, that is, in a case where the upper pedestal portion 23 and the lower pedestal portion 24 are seated parallel to each other, Is set so as to be balanced in the region of the first spring constant, and is balanced in the region of the second spring constant for a person having the highest weight to be used. Here, the minimum weight is, for example, 25 to 35 kg, and the maximum weight is, for example, 100 to 120 kg. The point of change from the first spring constant to the second spring constant may be between the minimum weight and the maximum weight, and is set to, for example, a load of 40 to 60 kg.

  Next, the operation of the second embodiment will be described. First, a case where a person sits down without tilting the seating surface S will be described. In this case, the gap between the upper pedestal portion 23 and the lower pedestal portion 24 is reduced by compressing the unequal-pitch springs 15 and the equal-pitch springs 16 according to the load at the time of sitting, and the upper pedestal portion 23 and the support portion The seat surface S of the seat portion 20 connected via the sink 22 sinks.

  Here, the characteristics of the unequal pitch spring 25 are balanced in the region of the first spring constant (narrow pitch region) for a person with the lowest weight that is assumed to be used, and for a person with the highest weight that is assumed to be used. It is set so as to be balanced in the region of the second spring constant (wide pitch region). Therefore, even if the person is light in weight, the seating surface S sinks down to give cushioning properties, giving an impression of comfortable sitting. Further, even in the case of a person with a heavy weight, the sink width of the seat surface S is relatively small, giving an impression that the sitting comfort is good. That is, sitting comfort is good regardless of weight.

  Next, a case where the seat surface S is inclined will be described. In the chair of the second embodiment, a load is applied in a direction in which a person wants to incline while seated, whereby the axis of the support portion 22 is inclined in the direction in which the load is applied, and the position of the seat surface S is interlocked with this. And the seating surface S can be inclined. The unequal-pitch spring 25 in the direction to which the load is applied is compressed, the upper pedestal 23 is tilted, the axis of the support 22 connected to the upper pedestal 23 is tilted, and the seat 20 connected to the support 22 is By tilting, the seating surface S tilts.

  Here, the characteristics of the unequal pitch spring 25 are balanced in the region of the first spring constant (narrow pitch region) for a person with the lowest weight that is assumed to be used, and for a person with the highest weight that is assumed to be used. It is set so as to be balanced in the region of the second spring constant (wide pitch region). Therefore, as the inclination angle of the axis of the support portion 22 increases, the load required for inclining increases, and the inclination of the support portion 22 stops in proportion to the load applied by the person seated at the predetermined inclination angle. . Therefore, it is easy to set the inclination angle of the axis of the support portion 22 to a desired state. Further, when the inclination angle of the shaft of the support portion 22 is small, the range in which the unequal pitch spring 15 is compressed without a load is narrow, and the wobble at the start of the inclination is reduced. In particular, in the chair of the second embodiment, since the position of the seat surface S also changes, the reduction of the wobble is reduced, and the risk of falling down from the chair is reduced, and the chair is excellent in safety.

  The chair of the second embodiment also has the same advantages as the first embodiment. That is, since the unequal pitch spring 25 is used to tilt the seat surface, stable sitting comfort can be realized regardless of the weight. Further, since the load required to incline as the angle of inclination of the shaft of the support portion 22 increases, the wobble of the seating surface S is suppressed from becoming unstable, and the support portion 22 is supported at an appropriate inclination angle. The inclination of 22 can be stopped. In the chair of the second embodiment, the maximum inclination angle of the support portion 22 is determined by the characteristics of the unequal pitch spring 25, and it is not necessary to provide any other inclination angle limiting means. Therefore, it is possible to reduce the cost of the chair in which the axis of the support portion 22 is inclined in all directions. In addition, the chair according to the second embodiment is suitable for working while sitting because the position itself of the seat surface S changes in addition to the inclination of the seat surface S. For example, when operating a plurality of PCs (personal computers), if the chair of the second embodiment is used, work can be quickly performed in a comfortable posture.

  The seat 20 of the chair of the second embodiment may have the same structure as the seat 10 of the first embodiment. In the chair of the second embodiment, when the axis of the support portion 22 is inclined, the seat surface S is also inclined. However, if the seat portion 20 has the same structure as the seat portion 10 of the first embodiment, the axis of the support portion 22 is When inclined, the angle formed by the seat portion 20 and the support portion 22 also changes, so that the seat surface S can be kept horizontal or close to it.

  Note that the chairs of the first and second embodiments can be added with various structures employed in conventionally known chairs. For example, although the backrest 12 is provided in the first embodiment and the backrest 12 is not provided in the second embodiment, the presence or absence thereof is optional in the present invention, and the backrest may be omitted from the chair of the first embodiment. A chair may be provided with a backrest. The armrest is also an arbitrary configuration in the present invention. The configuration of the leg 11 and the support 22 may be any conventionally known configuration.

  In the first and second embodiments, the number of the unequal-pitch springs 15 and 25 is four, but any number may be used as long as the number is three or more. However, in order to smoothly incline in any direction, the number is preferably 4 or more. Further, the unequal pitch springs may be arranged so as to be located at the vertices of the polygon. In the first and second embodiments, the equi-pitch springs 16 and 26 are provided at the center, but may be omitted.

  In the first and second embodiments, the characteristics of the four unequal-pitch springs 15 and 25 are all the same, but they may be set as follows. The first spring constant of the unequal pitch springs 15 and 25 disposed on the rear side (back side) of the chair is calculated based on the first spring constant of the unequal pitch springs 15 and 25 disposed on the front side (opposite the back side). Is set to be smaller than the second spring constant, and the second spring constant of the unequal pitch springs 15 and 25 arranged at the back of the chair is changed to the second spring constant of the unequal pitch springs 15 and 25 arranged at the front. It may be set to a larger value. With this setting, the seat surface S is less inclined at the rear of the chair than at the front, and safety can be improved. Alternatively, the deflection (deflection to the change point (compression length)) of the unequal pitch springs 15 and 25 arranged behind the chair until the spring constant changes from the first spring constant to the second spring constant is arranged in front. The deflection may be set smaller than the deflection of the unequal pitch springs 15 and 25 up to the changing point. Similarly, the seat surface S is less likely to be inclined behind the chair than in front, and safety can be improved.

  INDUSTRIAL APPLICABILITY The present invention can be used as a chair or a working chair for avoiding the same posture for a long time.

10, 20: seat 11: leg 12: backrest 13: upper seat 14: lower seat 15, 25: unequal pitch spring 16, 26: equal pitch spring 21: pedestal 22: support 23: upper Pedestal 24: Lower pedestal

Claims (8)

An upper seat part whose upper part is a seat surface,
A lower seat portion located below the upper seat portion,
Three or more unequal pitch springs coaxially arranged between the upper seat and the lower seat,
A leg connected to the lower seat below the lower seat;
Has,
The unequal pitch spring,
It is arranged to be the vertex position of the polygon,
A narrow-pitch region that is a first spring constant, and a wide-pitch region that is a second spring constant having a larger pitch than the narrow-pitch region and having a larger spring constant than the first spring constant;
The narrow pitch region is compressed, and the wide pitch region is set so that the uncompressed state is a mounting length and does not extend beyond the mounting length,
In a state where a person is seated without inclining the upper seat portion, the narrow pitch region is balanced for a person supposed to use the lowest weight, and a wide pitch region is used for a person supposed to use the highest weight. Is set to balance
The minimum weight is 25 to 35 kg, and the maximum weight is 100 to 120 kg.
A chair characterized by that: A seat part whose upper part is a seat surface,
A pedestal located below the seat;
A support portion connecting the seat portion and the pedestal portion,
Has,
The pedestal,
An upper pedestal portion to which the support portion connects,
A lower pedestal located below the upper pedestal,
Three or more unequal pitch springs coaxially arranged between the upper pedestal and the lower pedestal,
Has,
The unequal pitch spring,
It is arranged to be the vertex position of the polygon,
A narrow-pitch region that is a first spring constant, and a wide-pitch region that is a second spring constant having a larger pitch than the narrow-pitch region and having a larger spring constant than the first spring constant;
The narrow pitch region is compressed, and the wide pitch region is set so that the uncompressed state is a mounting length and does not extend beyond the mounting length,
In a state where the person is seated without tilting the support portion, the person with the lowest weight assuming use is balanced in the narrow pitch area, and the person with the highest weight assuming use in the wide pitch area. Is set to balance,
The minimum weight is 25 to 35 kg, and the maximum weight is 100 to 120 kg.
A chair characterized by that: A first spring constant of the unequal-pitch spring disposed behind the chair is set to be larger than a first spring constant of the unequal-pitch spring disposed in front and smaller than a second spring constant.
A second spring constant of the unequal pitch spring disposed behind the chair is set to be larger than a second spring constant of the unequal pitch spring disposed in front of the chair.
The chair according to claim 1 or claim 2, wherein The deflection from the first spring constant to the second spring constant of the unequal-pitch spring disposed at the back of the chair changes from the first spring constant to the second spring constant of the unequal-pitch spring disposed at the front. Is set smaller than the deflection before
The chair according to claim 1 or claim 2, wherein An upper seat part whose upper part is a seat surface,
A lower seat portion located below the upper seat portion,
Three or more unequal pitch springs coaxially arranged between the upper seat and the lower seat,
Legs connected to the lower seat below the lower seat;
A method for manufacturing a chair having
The unequal-pitch springs are arranged so as to be located at the vertices of a polygon, and have a narrow pitch region as a first spring constant, a pitch wider than the narrow pitch region, and a spring constant higher than the first spring constant. A wide pitch region having a large second spring constant, wherein the narrow pitch region is compressed, and the wide pitch region is set so that the uncompressed state is a mounting length and does not extend beyond the mounting length; In a state where a person is seated without inclining the upper seat portion, for a person having the lowest weight to be used, the narrow pitch area is balanced, and for a person having the highest weight to be used, a wide pitch area is used. Set to balance,
A method for manufacturing a chair, comprising: A seat part whose upper part is a seat surface,
A pedestal located below the seat;
A support portion connecting the seat portion and the pedestal portion,
Has,
The pedestal,
An upper pedestal portion to which the support portion connects,
A lower pedestal located below the upper pedestal,
Three or more unequal pitch springs coaxially arranged between the upper pedestal and the lower pedestal,
A method for manufacturing a chair having
The unequal-pitch springs are arranged so as to be located at the vertices of a polygon, and have a narrow pitch region as a first spring constant, a pitch wider than the narrow pitch region, and a spring constant higher than the first spring constant. A wide pitch region having a large second spring constant, wherein the narrow pitch region is compressed, and the wide pitch region is set so that the uncompressed state is a mounting length and does not extend beyond the mounting length; In a state where the person is seated without tilting the support part, the person weighing the minimum weight to be used is balanced in the narrow pitch area, and the person weighing the maximum weight to be used is balanced in the wide pitch area. Set to
A method for manufacturing a chair, comprising: A first spring constant of the unequal pitch spring disposed behind the chair is set to be larger than a first spring constant of the unequal pitch spring disposed in front and smaller than a second spring constant.
A second spring constant of the unequal pitch spring disposed behind the chair is set to be larger than a second spring constant of the unequal pitch spring disposed in front of the chair.
The method of manufacturing a chair according to claim 5 or 6, wherein The deflection from the first spring constant to the second spring constant of the unequal-pitch spring disposed at the back of the chair changes from the first spring constant to the second spring constant of the unequal-pitch spring disposed at the front. Set smaller than the deflection before
The method for manufacturing a chair according to claim 5 or 6, wherein