JPH07140U - Chair direction restoration device - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention enhances cushioning performance by allowing a fixed cam member to receive a load applied at the time of seating, without using a fixed cam member, and to improve the cushioning property of a cam surface or a protrusion guided by this. An object of the present invention is to provide a chair direction restoring device that prevents damage and enhances reliability. [Structure] A fixed cam member 4 having an inclined cam surface 41 formed on the bottom is fixed in a cylindrical support pipe 1 supported on a floor surface, and is slidable up and down at the center of the fixed cam member 4. A shaft rod 5 is provided which penetrates and is connected to the seat portion of the chair. The shaft rod 5 is provided with a stopper 52 that regulates downward sliding at a predetermined position, and a protrusion 6 that abuts against the cam surface 41 to regulate upward sliding and is guided. The stem 6
The mounting position is set at a position where the protrusion 6 does not abut against the cam surface 41 even if the shaft rod 5 rotates when the shaft rod 5 slides downward. Since the shaft rod 5 is biased upward by the recoil spring 3, the shaft rod 5 is automatically returned by being guided by the protrusion 6.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a rotary chair directional restoring device that improves strength and durability without receiving a load applied when seated on a fixed cam member and has excellent cushioning properties.

[0002]

[Prior art]

 Conventionally, as the direction restoring device of this type of chair, there have been known, for example, Japanese Utility Model Publication No. 43-10011, Japanese Utility Model Publication No. 60-145844, and Japanese Utility Model Application No. Sho 63-38846 proposed by the applicant. In both cases, since the cam surface and the part guided by the cam face always abut against each other, the load applied during seating is applied to all the guided parts through the guide surface. Further, if the portion guided by the cam surface abuts against each other even during rotation, it becomes a resistance and the rotation cannot be performed smoothly.

[0003]

[Problems to be solved by the device]

 This device was created as a result of earnest research in view of the above circumstances, and its main problem is to increase the cushioning property by allowing the biasing means to receive the load applied at the time of sitting without the fixed cam member receiving it. At the same time, the purpose of the present invention is to provide a chair direction restoration device which prevents damage to the cam surface and the protrusion guided by the cam surface and improves reliability.

[0004]

[Means for Solving the Problems]

 In order to solve the above problems, in the present invention, in a chair direction restoration device that automatically rotates and rotates a rotated chair in the original direction, an inclined cam surface is formed on the bottom surface inside a cylindrical support pipe. The fixed cam member is fixed, a shaft rod is slidably penetrated vertically in the center of the fixed cam member, and a shaft rod connected to the seat portion of the chair is provided. The shaft rod is slid downward at a predetermined position. Is provided with a stopper that is regulated by a.A protrusion is provided at an intermediate position of the shaft rod that is guided when it abuts against the cam surface and regulates sliding upward. When the shaft rod slides downward, the protrusion is set to a position where it does not collide with the cam surface even if the shaft rod rotates. The urging means for urging the shaft rod upward is provided in the support pipe. The technical means of establishing it in

[0005]

[Action]

 At the time of seating, the shaft rod slides downward and descends to a position where the protrusion does not abut the guide surface, and the stopper stops the descending of the shaft rod. At that position, the stem separates from the guide surface, so the shaft rod can be rotated freely with almost no resistance. Further, when the load is not applied to the shaft rod, the shaft rod slides upward by the biasing means, and the protrusion abuts against an arbitrary cam surface. Here, the cam surface is an inclined surface, and since the projecting member is biased upward through the shaft rod, the projecting member is guided by the cam surface and moves in the circumferential direction to rotate the shaft rod. While moving to the upper end position of the cam surface. As a result, the seat of the chair, which is connected to the upper part of the axle, automatically rotates and returns to its original position.

[0006]

【Example】

 A preferred embodiment of the chair direction restoring device of the present invention will be described below with reference to the drawings. In the chair direction restoring device shown in FIG. 1, a cylindrical support pipe 1 is fixed and supported on a leg stand 2 fixed to an installation surface such as a floor.

A lower pedestal 33 is fixed or held in a fixed position in the supporting leg pipe 1, and a recoil spring 3 is vertically mounted on the lower pedestal 33. Although one recoil spring 3 is used in the illustrated example, a small-diameter recoil spring 3 may be inserted inside to be used in duplicate.

A cup-shaped upper pedestal 31 is fitted on the recoil spring 3. A protrusion 32 is formed at the center (center position) of the upper pedestal 31. On the other hand, a fixed cam member 4 is fixed to the upper opening side of the supporting leg pipe 1 so as to cover the opening. An inclined cam surface 41 is formed on the bottom surface of the fixed cam member 4.

In the present embodiment, the cam surface 41 is formed in an annular shape in the circumferential direction along the outer peripheral edge of the bottom surface of the fixed cam member 4 with a predetermined width (a width with which a protrusion 6 described later abuts). Here, the highest portion of the cam surface 41 may be formed with an abutting portion on the flat surface 41a so that the protrusion 6 is stabilized at that position.

Next, the fixed cam member 4 is provided with a hole vertically passing through the center thereof, and the shaft rod 5 connected to a seat portion of a chair (not shown) can slide vertically in the hole. Has been inserted into. The shaft rod 5 has a split groove 53 formed at its upper end for interlockingly connecting with the mounting portion of the seat portion of the chair, and the stopper 52 is provided in the middle portion protruding above the fixed cam member 4. Are integrally formed. Here, a concave portion 43 into which the stopper 52 is fitted is formed on the upper surface of the fixed cam member 4 to restrict the sliding range of the shaft rod 5 downward.

A protrusion 6 is provided at an intermediate portion of the shaft rod 5 that protrudes downward from the fixed cam member 4. The protrusion 6 may be a member that abuts the guide surface 41 and is guided by the inclined surface, and may be a simple rod-shaped member. Uses rollers. That is, the protrusion 6 has a structure in which a protrusion shaft 61 that horizontally protrudes from the shaft rod 5 is integrally formed, and a roller is rotatably attached to the protrusion shaft.

The lower end of the shaft rod 5 is supported by the upper pedestal 31 and is rotatable. A recess 51 is formed on the lower end surface of the shaft rod 5 so as to be aligned with the projection 32 of the upper pedestal 31, and the projection 32 of the upper pedestal is engaged with the recess 51, and this engaging position With the center as the center, the shaft rod 5 is rotatable.

Next, the operation of the chair direction restoring device will be described. When the chair is not used, the rod 5 is raised by the urging force of the recoil spring 3 through the upper pedestal 32, and the protrusion 6 abuts the bottom surface of the fixed cam member 4 and is guided to the inclined surface. It moves to the highest position 41a and stops there (see FIG. 1). Then, the position in this state is the frontal normal position.

When a person now sits on the seat of the chair, the rod 5 slides downward against the urging force of the recoil spring 3 and moves down to a position where the stopper 52 shown in FIG. Suru In this state, since the protrusion 6 does not collide with the guide surface 41, the shaft rod 5 is rotatable, so that the seated person can rotate in any direction.

When the seated person stands up, the load applied to the shaft rod 5 disappears. Therefore, as described above, the shaft rod 5 is moved upward by the urging force of the recoil spring 3, and the protrusion 6 is moved to any position on the cam surface 41. Ascend to the position where you hit. When the protrusion 6 collides with the cam surface 41, the protrusion 6 is guided by the cam surface 41 and is displaced to the highest position 41a, so that the seat portion rotates in conjunction with this and the seat portion rotates to the original normal position. Can be restored.

In the above-described embodiment, an example in which a recoil spring is used as the urging means has been shown, but the urging means may be another spring or a structure utilizing gas pressure, and is not limited to the above-mentioned embodiment. In addition, it goes without saying that various design changes can be made without departing from the spirit of the present invention.

[0017]

[Effect of device]

 In the chair automatic restoration device of the present invention, the load applied at the time of sitting can be received by the biasing means without being received by the fixed cam member, and the cushioning property can be enhanced to make the sitting comfort. Further, since the load of the seated person is not applied to the cam surface and the protrusion guided by this, damage to these members can be prevented and reliability can be improved.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a chair direction restoring device of the present invention.

FIG. 2 is a cross-sectional view showing a chair direction restoring device in a sitting state.

FIG. 3 is a cross-sectional view showing a chair direction restoring device in which a seated person stands up.

[Explanation of symbols]

 1 Support pipe 2 Leg base 3 Recoil spring 4 Fixed cam member 5 Axle rod 6 Protrusion

Claims (4)

[Scope of utility model registration request] 1. A chair direction restoring device for automatically returning and rotating a rotated chair in the original direction, wherein a fixed cam member having an inclined cam surface formed on the bottom surface is fixed in a cylindrical support pipe, A shaft rod that slidably penetrates vertically in the center of the fixed cam member and that is connected to the seat portion of the chair is provided, and a stopper that restricts downward sliding at a predetermined position is provided on the shaft rod, A protrusion is provided at an intermediate position of the shaft rod so as to restrict the sliding in the upward direction by abutting the cam surface and to be guided, and the mounting position of the protrusion causes the shaft to slide when the shaft rod slides downward. The chair is characterized in that the protrusion is set at a position where it does not abut against the cam surface even if the rod rotates, and the urging means for urging the shaft rod upward is provided in the support leg pipe. Direction restoration device. 2. The urging means comprises a recoil spring built in the support leg pipe, and an upper pedestal for rotatably receiving the lower end of the shaft rod is placed on the upper portion thereof. Item 1. The chair direction restoration device according to Item 1. 3. The chair direction restoring device according to claim 1, wherein the fixed cam member has an upper surface formed with a recess into which a stopper integrally provided with the shaft rod is fitted. 4. The protrusion comprises a roller that rotates in abutment with a rotatable cam surface.
The chair direction restoration device described in.