JP3034646U - Chair with protrusions on the backrest - Google Patents

Abstract

(57) Abstract: To provide a backrest having a protrusion that appears only when necessary. SOLUTION: A chair provided with a protrusion on a backrest, which is provided with a protrusion capable of advancing and retracting toward the back of a seated person.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 This invention belongs to the back of a chair, where shiatsu can be applied to the back or waist while sitting.

[0002]

[Prior art]

 Various chairs having a backrest provided with projections for acupressure have been devised in order to relieve stiff shoulders and low back pain while sitting (Japanese Patent Laid-Open Nos. 57-86310, 7-171 034, and Japanese Utility Model Laid-Open 55-55). 56156, 577-123064, 573-133344, 60-74662, 1-126237.

[0003]

[Problems to be solved by the device]

 However, the projections provided on the backs of chairs that have been conventionally devised are fixed without any projections. Therefore, when the acupressure is not necessary, it is painful if the back hits the protrusion and cannot lean back. In addition, a removable backrest device has been devised (actually 5-11863), but since it is not something that can be attached and removed in an instant, it is troublesome to attach and remove. In particular, in order to apply it to chairs that pachinko players sit in while playing, it is essential that the structure is not stolen, but there is no chair with a suitable structure.

Therefore, an object of the present invention is to provide a backrest having a protrusion that appears only when necessary.

[0005]

[Means for Solving the Problems]

 In order to achieve the above-mentioned object, the backrest of this invention is provided with a protrusion capable of moving forward and backward toward the back of a sitting person. Therefore, when acupressure is necessary, the protrusion is advanced toward the back. On the other hand, when acupressure is not needed, the back of the backrest is as smooth as a chair without a protrusion by retracting the protrusion, so that the back does not hurt.

[0006]

[Embodiment of the invention]

 An embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing a chair with a backrest according to an embodiment, and FIG. 2 is a perspective view of a main part of FIG.

This chair is fixed to a backrest 10 on a backrest 10 of a seated person, and a guide member 2 for restricting the forward / backward direction of the projection, and fixed to the rear of the projection so as to intersect the forward / backward direction of the projection. A rotating shaft 3 having an axis in the direction of rotation and a link device 4 are provided.

The protrusion 1 has a rounded tip so as not to hurt the back, and has link attachment shafts 11 on both sides on the diameter line. The guide member 2 has a tubular shape that slides on the outer periphery of the protrusion 1, and has a slit 21 that is long in the axial direction at a position facing the axis of the protrusion. The link mounting shaft 11 is fitted in the slit 21. The engagement between the link mounting shaft 11 and the slit 21 prevents the rotation of the protrusion 1 and allows the protrusion 1 to move only in the axial direction.

The rotating shaft 3 is rotatably fixed to the backrest via a bearing 31, and a lever 32 is attached to one end of the rotating shaft 3. The link device 4 includes a driving side link 41 and a driven side link 42. The drive side link 41 is integrally attached to the rotary shaft 3 and swings as the rotary shaft 3 rotates. The driven side link 42 has one end rotatably fixed to the tip of the driving side link 41 and the other end fixed to the link mounting shaft 11.

In the backrest 10, the lever 32 is normally directed upward and the protrusion 1 is retracted. Therefore, even if the person leans back, the back does not hurt. When the back or waist becomes tired, the lever 32 is tilted forward. Then, the driving-side link 41 falls forward as the rotary shaft 3 rotates, and the driven-side link 42 is pushed forward. At the same time as the driven side link 42, the protrusion 1 moves forward, goes out from the surface of the backrest 10, and presses the back or waist. In the pressed state, the angle formed by both links 41 and 42 is 180 °, and the protrusion 1 does not retract even if weight is applied to the tip of the protrusion 1, but the lever 32 must be rotated to return upward. Thereby, the protrusion 1 easily returns to the original position.

Next, another embodiment of the present invention will be described with reference to FIGS. 3 and 4. FIG. 3 is an enlarged perspective view of an essential part showing a backrest 20 of another embodiment, and FIG. 4 is a horizontal sectional view of the backrest. The rotational force applied from the lever 32 of FIG. 2 is transmitted to the protrusion 1 by the cam device 5 instead of the link device 4.

Therefore, the link mounting shaft 11 becomes the follower mounting shaft 12. The cam 51 has a shape in which the distance from the center of the rotating shaft 3 to the contour changes smoothly and endlessly. A surface of the follower 52 that slides with the cam 51 is curved along the outer peripheral surface of the cam 51 at a constant position, and the opposite surface is a flat surface. The opposite surface is urged by the spring 53 in the direction of pushing the cam 51.

In the backrest 20, the lever 32 is normally directed rearward and the protrusion 1 is retracted. Therefore, even if the person leans back, the back does not hurt. When the back or waist becomes tired, the lever 32 is rotated downward. Then, the cam 51 rotates with the rotation of the rotary shaft 3, the contact point between the center of rotation and the follower 52 is gradually separated, and the follower 52 is pushed forward against the elastic force of the spring 53. Simultaneously with the follower 52, the protrusion 1 moves forward, goes out of the surface of the backrest 10, and presses the back or waist. In the pressed state, the straight line connecting the center of the rotary shaft 3 and the follower 52 overlaps with the advancing / retreating direction of the follower 52, and the protrusion 1 does not retract even if weight is applied to the tip of the protrusion 1, but the lever 32 The support of the cam 51 is released by rotating and returning to the rear, and the protrusion 1 is easily returned to the original position by the restoring force of the spring 53.

In the above example, the simplest human power was used as the drive source for moving the protrusions forward and backward, but the drive source is not limited to this, and hydraulic pressure, pneumatic pressure, an electric motor, or the like may be used.

[Brief description of the drawings]

FIG. 1 is a front view showing a chair with a backrest according to an embodiment.

FIG. 2 is an enlarged perspective view of a main part of the backrest.

FIG. 3 is an enlarged perspective view of a main part of a backrest of another embodiment.

FIG. 4 is a horizontal sectional view of the backrest of FIG.

[Explanation of symbols]

 10, 20 Backrest 1 Protrusion 2 Guide member 3 Rotating shaft 4 Link device 5 Cam device

Claims (3)

[Utility model registration claims] 1. A chair having a protrusion on a backrest, wherein the chair is provided with a protrusion capable of advancing and retracting toward the back of a sitting person. 2. A protrusion that can move forward and backward toward a seated person's back, a guide member that regulates the forward and backward directions of the protrusion, and a rotation that is fixed to the rear of the protrusion and has an axis in a direction intersecting the forward and backward directions of the protrusion. A backrest of a chair, comprising: a shaft; and a link device that connects the rotation shaft and the protrusion and that advances and retracts the protrusion as the rotation shaft rotates. 3. A protrusion that can move forward and backward toward a seated person's back, a guide member that regulates the forward and backward directions of the protrusion, and a rotation that is fixed to the rear of the protrusion and has an axis in a direction intersecting the forward and backward directions of the protrusion. A backrest of a chair characterized by including a shaft and a cam device for converting the rotational movement of the rotary shaft into a linear movement in the forward / backward direction of the protrusion, and the follower being biased by an elastic member in the backward direction of the protrusion. .