JP2007325689A - Backrest structure of chair - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve the convenience of a chair by easily adjusting the degree of pressure on the hips of a seated person and the angle of backward inclination of a back panel on the whole. <P>SOLUTION: A backrest frame 2 which is formed in substantially an L-shape as seen from a side, is supported in such a way that the angle of backward inclination can be adjusted by pivotally attaching the lower end of the backrest frame 2 to a support base 5 located on the lower side of a seat panel 1. The back panel is composed of an upper chest part 16 and a lower waist part 17. A chest part support member 18 for supporting the chest part is pivotally attached to the backrest frame in such a way as can slide in the vertical direction, and the upper end of a waist support member 19 for supporting the waist part is pivotally attached to the lower end of the chest support member in such a way as can bend forward/backward. The waist support member is formed in the S-shape as seen from a side, and the lower end of the waist support member is pivotally attached to the backrest frame in the front of an L-shaped bending part of the backrest frame. The backrest structure also has a gap adjusting member 35 for connecting the region around the pivotally attached part of the chest support member and the waist support member to the backrest frame. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a chair backrest structure mainly used for office work.

As shown in FIG. 8, the chair backrest structure shown in Patent Document 1 below is supported so that the back frame a can be tilted rearward with a support shaft j provided on the seat base portion b as a fulcrum. The lower part c of the back plate is fixed to the upper part of the frame, and the lower end part of the control link e which is provided with a connection point d on the back frame and extends upward is pivotally connected to the connection point d. a displacement such as an adjusting screw that can be refracted in the front-rear direction with respect to c, and that connects the upper part f to the upper end of the control link e by connecting means g and changes the distance between the back frame a and the control link e. Means h were provided.
JP 2004-434 A Japanese Patent Laid-Open No. 10-179314 Japanese National Patent Publication No. 9-503144

By the way, the chair backrest structure shown in the above-mentioned Patent Document 1 is such that when the inclination angle of the back frame a is adjusted, not only the lower part c of the backboard but also the upper part f of the backboard moves in the front-rear direction. Therefore, when only the lower part c is to be adjusted, the position of the upper part f needs to be readjusted by the displacement means h. For this reason, there is a problem that it is difficult to adjust the position of only the lower part c while keeping the upper part f as it is, and it becomes difficult to adjust, and it takes time and effort to adjust to a desired state.
Further, the chair shown in Patent Document 2 also has the same problem as the chair shown in Patent Document 1 because of its structure.
On the other hand, the split back chair shown in Patent Document 3 divides a flexibly formed back plate into an upper ribcage and a lower waist, and each is supported on a seat plate by a support device independently. However, in this structure, if the entire back plate is tilted, the support devices for both the rib cage and the lumbar region must be adjusted, which makes the operation troublesome.

  The backrest structure of the chair according to the present invention is intended to solve the above-mentioned problem, and the lower frame is formed by pivotally attaching the lower end of the back frame formed in a substantially L-shaped side surface to the support base located below the seat plate. The back plate is composed of an upper ribcage and a lower waist, and the rib support member that supports the rib is pivoted so that the back frame can be slid vertically. The upper end of the lumbar support member that supports the lumbar part is pivotally attached to the lower end of the thorax support member so that it can be bent in the front-rear direction, and the lumbar support member is formed in a substantially S-shaped side surface, The lower end portion of the member is pivotally attached to the back frame at the front portion of the L-shaped refracting portion of the back frame, and further, the interval connecting the vicinity of the pivot portion between the ribcage support member and the waist support member and the back frame. An adjustment member is provided.

  Since the degree to which the seated person's waist is pressed and the rearward inclination angle of the entire back plate can be easily adjusted, the usability of the chair is remarkably improved.

  FIG. 1 is a side view showing a configuration of a chair according to the present invention. In the figure, reference numeral 1 denotes a seat plate having a cushion material stretched on its upper surface, and 2 denotes a back frame formed in a substantially L-shaped side surface. As shown in the rear view of FIG. 2, the back frame 2 is formed by connecting a connecting member 3 to the upper ends of two frame members obtained by bending, for example, an iron pipe or the like into a substantially L-shape, and welding the L-shaped bend. Even in the vicinity of the frame portion, the connecting material 4 is fixed between the frame materials by welding or the like to form a frame shape, and the lower end of the back frame 2 is supported on the support base 5 positioned below the seat plate 1. By pivoting with 6, the back frame 2 is supported so that it can be tilted backward with the support shaft 6 as a fulcrum.

  The support base 5 is provided at the upper end of the column 8 supported by the legs 7 so as to be rotatable in a horizontal plane, and the seat plate 1 is supported on the support base. Reference numeral 9 denotes a support frame fixedly provided on the lower surface of the seat plate 1. The horizontal shaft 10 is installed near the lower front edge of the support frame, and the horizontal shaft 11 is installed near the lower rear edge of the support frame. Horizontally, the horizontal shaft 10 is loosely fitted in the long holes 12 formed in both side walls of the support base 5, and the horizontal shaft 11 is inserted into the shaft support piece 13 protruding from the back frame 2. Thus, the seat plate 1 is supported on the support base.

  The back plate 15 is divided into an upper thoracic portion 16 and a lower lumbar portion 17, and cushion members 16a and 17a are stretched on the front surfaces of the thoracic portion 16 and the lumbar portion 17, respectively. Reference numeral 18 denotes a thoracic part support member comprising two flat bars fixed to the back surface of the thoracic part 16 and supporting the thoracic part 16. Reference numeral 19 denotes two thoracic part support members fixed to the back surface of the lumbar part 17 and supporting the lumbar part 17 from the back side. A waist support member made of a flat bar. The thoracic portion 16 is supported by a thoracic support member 18 that is curved slightly rearward so that the front surface has a gentle roundness that fits the back of the seated person, and the upper end of the thoracic support member is the upper end of the back frame 2. Are connected via connecting means 20 pivotally attached so that vertical sliding is allowed. That is, a long hole 21 that is long in the vertical direction is formed in the upper end portion of the rib cage support member, and a pair of protrusions projecting forward from the front surface of the connecting member 3 to the upper end portion of the back frame 2 as shown in FIG. A shaft support piece 22 is formed, and a support shaft 23 supported by the shaft support piece is loosely fitted into the long hole 21 so that the rib support member 18 can be slid in the vertical direction within the range of the long hole. The upper end is connected to the upper end of the back frame 2.

  Further, the waist support member 19 is formed in a gently curved shape above the seat plate 1 so that the waist portion 17 can press the seated person from the pelvis to the waist, and the rear edge of the seat plate 1 By extending to the lower side of the seat plate 1 while avoiding the above, the side surface is formed in an approximately S shape. Then, the upper end portion of the waist support member 19 is pivotally attached to the lower end portion of the rib cage support member 18 so as to be able to bend in the front-rear direction with a pivot 24, and the lower end portion of the waist support member 19 is connected to the L-shaped refraction portion of the back frame 2. Further, it is pivotally attached to the back frame 2 by a pivot 25 at a front portion.

  Reference numeral 30 denotes an inclination angle adjusting member made of a gas spring which makes it possible to adjust the rear inclination angle of the back frame 2, and one end of the gas spring is pivotally attached to a shaft support piece 31 fixed to the connecting member 4 of the back frame 2. In addition, the other telescopic operating rod tip of the gas spring is connected to a support shaft 32 that is horizontally mounted on the support base 5. An operation portion 33 is provided on the lower side of the seat plate 1 so that the tilt angle adjustment member can be manually operated by a seated person, and the operation portion and the gas spring are connected by a control wire (not shown). It is connected.

  Reference numeral 35 denotes a gap adjusting member made of a gas spring that connects the vicinity of the pivot portion between the ribcage support member 18 and the waist support member 19 and the back frame 2, and is placed horizontally near the upper end of the waist support member 19. A shaft support piece 37 protrudes from the connecting member 36, one end of the gas spring is pivotally attached to the shaft support piece, and the other extension operating rod tip of the gas spring is fixed to the connecting member 4. It is connected to the piece 38. An operation portion 39 is provided symmetrically with the operation portion 33 on the lower side of the seat plate 1 so that the distance adjusting member can be manually operated by a seated person, and controls the operation portion and the gas spring. They are connected by a wire (not shown).

  In the chair configured as described above, when the user operates the operation unit 39 while sitting on the seat plate 1, the gas spring of the interval adjusting member 35 extends, so that the thoracic support member 18 and the lumbar support member 19 As shown in FIG. 4, the thorax support member 18 rotates forward with the connecting means 20 as a fulcrum and the lumbar support member 19 rotates forward with the pivot 25 as a fulcrum. 16 and the waist portion 17 are pushed forward like a bow, and the pelvis can be raised by pressing the waist of the seated person. Then, by releasing the hand from the operation unit 39, the interval adjusting member 35 is fixed to the length at that time, so that the rib cage portion 16 and the waist portion 17 can be held in their preferred state.

Further, the gas spring of the tilt angle adjusting member 30 contracts when the seated person operates the operating portion 33 and pushes the back plate 15 backward with the back, so that the back plate 15 is moved as shown in FIG. The tilt angle adjusting member 30 is fixed to the length at that time by releasing the hand from the operation portion 33 when the tilted angle is reached. Can be held. Then, by operating the operation portion 39, as shown in FIG. 6, the gas spring of the interval adjusting member 35 is extended, and the rib cage portion 16 and the waist portion 17 are pushed forward like a bow, The waist of the seated occupant in the desired reclining state can be pressed while maintaining the inclination angle, and the interval adjustment member 35 is fixed to the length at that time by releasing the hand from the operation unit 39, so that the rib cage The bowed state of the part 16 and the waist part 17 can be fixed to a desired level.
In the chair shown in this embodiment, since the rear side of the seat plate 1 is supported on the back frame 2 by the horizontal shaft 11, when the back plate 15 is tilted backward, the seat plate 1 is shown in FIGS. As shown, it is tilted slightly backward to make it difficult for the seated person to slide forward.

  In this backrest structure, the waist support member 19 is formed in a substantially S-shaped side surface, and the lower end portion of the waist support member 19 is pivoted to the back frame 2 by a pivot 25 at a portion forward of the L-shaped refracting portion of the back frame 2. Since the lumbar part 17 is rotated about the pivot 25 as a fulcrum, the lumbar part 17 moves back and forth in a substantially horizontal direction and hardly moves up and down, so that the lumbar part 17 is always reliably moved with respect to the waist of the seated person. Can be fitted.

  As described above, in the chair of the present invention, the rib cage support member 18 is supported on the upper end portion of the back frame 2 that is supported so that the rearward tilt angle can be adjusted, so that the distance can be adjusted without changing the rearward tilt angle of the back frame 2. By simply adjusting the setting of the member 35, the rib cage portion 16 and the waist portion 17 are bowed forward, and the degree to which the seated person's waist is pressed can be easily adjusted. Incidentally, FIG. 7A shows that the seated person is bent slightly forward by sitting on a chair in which the back frame 2 is standing and the rib cage 16 and the waist 17 are retracted. FIG. 4B shows a state in which the back of the back frame 2 is in an upright state, and the waist of the seated person is pressed by the bow 16 and the waist 17 being bowed forward. As can be seen by comparing (A) and (B) in FIG. 7, the height of the thoracic portion and head of the seated person is kept substantially constant, and the keyboard is kept in a state that does not hinder the operation. Thus, only the degree to which the seated person's waist is pressed can be easily adjusted by setting the interval adjusting member 35. For this reason, the seated person's waist is always kept in an appropriate pressing state, and the entire body of the seated person is backed up, so that the degree of fatigue can be remarkably reduced even during long office work.

  Further, if the tilt angle adjusting member 30 is operated to change the rear tilt angle of the back frame 2, the degree of pressing the seated person's waist is maintained in a desired state, as shown in FIGS. The rear tilt angle of the entire back plate can be freely adjusted to be in a reclining state and ready for relaxation. For this reason, the chair of this invention can always be easily set to a user's favorite state, and becomes very easy to use.

In this embodiment, the thoracic portion 16 and the lumbar portion 17 are formed separately from each other. However, the thoracic portion 16 and the lumbar portion 17 and the cushion material 16a and the cushion material 17a are formed integrally and bendable. It may be a thing.
In this embodiment, the thoracic portion 16 and its supporting member 18 are formed separately, and the lumbar portion 17 and its supporting member 19 are also formed separately. However, the thoracic portion 16 is integrated with the thoracic portion 16. Alternatively, the waist support member 19 may be formed integrally with the waist 17. Moreover, these structural members are not limited to the above-described embodiment, and can be formed from an appropriate material such as iron, aluminum, or plastic.
Further, a cover (not shown) may be provided on the back plate 15 or the support base 5 to cover the back frame 2, the connecting means 20, the tilt angle adjusting member 30, the interval adjusting member 35, and the like.
Moreover, although the said connection means 20 was pivotally attached by providing the long hole 21 so that the up-down direction sliding of the thorax part support member 18 was accept | permitted, it connects not only with a long hole but through a slide rail or a link. In other words, the thoracic support member may be slidably pivotally attached to the back frame by the connecting means 20.
In this embodiment, the gas spring is used as the inclination angle adjusting member 30 and the interval adjusting member 35, but other mechanical means such as a screw screw or a cam can be used.

The side view of the chair which shows embodiment of this invention. The rear view of the backrest of the chair which shows embodiment of this invention. The top view of the backrest of the chair which shows embodiment of this invention. The operation state figure of the chair shown in FIG. The operation state figure of the chair shown in FIG. The operation state figure of the chair shown in FIG. The side view which showed the use condition of the chair which concerns on this invention. The longitudinal cross-section side view which shows the backrest structure of the conventional chair.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Seat plate 2 Back frame 5 Support base 6 Support axis 15 Back plate 16 Thorax part 17 Lumbar part 18 Thorax part support member 19 Lumbar support member 20 Connecting means 21 Long hole 23 Support axis 24 Axis 25 Axis 30 Inclination angle adjustment member 33 Operation part 35 Spacing adjustment member 39 Operation section

Claims (1)

  By supporting the lower end of the back frame formed in a substantially L-shaped side surface to the support base located below the seat plate, the back frame is supported so that the rearward tilt angle can be adjusted. A thoracic support member comprising a lumbar part is pivotally attached to the back frame so as to be allowed to slide in the vertical direction, and the upper end part of the lumbar support member supporting the lumbar part is supported by the thoracic part. The waist support member is pivotally attached to the lower end portion of the member so as to be refracted in the front-rear direction, and the waist support member is formed in a substantially S-shape on the side surface. A backrest structure for a chair, characterized in that it is pivotally attached to the back frame and further provided with an interval adjusting member for connecting the vicinity of the pivot portion between the ribcage support member and the waist support member and the back frame.

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