JP4486352B2 - Operation device for gas spring in chair - Google Patents

Description

  The present invention relates to a gas spring operating device that adjusts, for example, the tilt angle of the backrest of a chair or adjusts the height of a seat.

  As a means for applying an urging force when the chair back is tilted backward or locking the chair at an arbitrary tilt angle, there is one using a gas spring (see, for example, Patent Document 1).

  When using such a gas spring, the lower end of the cylinder is pivotally attached to the rear upper end of the leg rod, and the upper end of the piston rod is pinned to a bracket fixed to the back frame via a connecting bracket or the like. In general, the pivots are connected so as to be pivotable.

In addition, a push rod of a control valve that freely expands and contracts the gas spring or locks it at an arbitrary expansion / contraction position is projected from the upper end of the piston rod, and this push rod is pressed by the operating device.
JP 2003-245153 A

  As described above, when the upper end of the piston rod of the gas spring is connected to the bracket fixed to the back frame with a pin, an annular groove is usually formed on the outer peripheral surface of the tip of the pin and snapped into this annular groove. A ring is inserted to prevent the pin from coming off.

  However, in this method, since it is necessary to process an annular groove on the pin or to fit a snap ring, there is a problem that the number of processing and assembling steps and the number of parts increase.

  In order to solve this problem, as described in the above-mentioned patent document, a pair of support plates having upward pieces on the opposite end edges are fixed to the mounting portions of the left and right side brackets in the back frame. The bracket is attached to the back frame between the upper pieces of both support plates, and the upper end of the gas spring and the bracket are simply connected by straight pins, and the side ends of the pins are connected to the upper pieces of the support plates. It is also conceivable to prevent contact by coming into contact.

  However, if this is done, the structure of the spine frame becomes complicated and there is also a profound feeling, so that the appearance is deteriorated.

  The present invention has been made in view of the above-described problems, and is provided with a stopper for attaching a retaining member by processing the pivot for connecting a gas spring, or by providing a retaining member for a pivot on a movable part such as a back frame. It is an object of the present invention to provide a gas spring operating device for a chair that can prevent the pivot from coming off by simple means.

According to the present invention, the above problem is solved as follows.
(1) One end portion of the gas spring from which the push rod of the control valve protrudes is connected to the movable portion of the chair by a pivot orthogonal to the axis of the gas spring, and the other end portion of the gas spring is connected to the chair. A gas spring in a chair that is supported by a fixed portion and that adjusts the position of the movable portion by pushing the push rod with a pressing member that is linked to an operation lever and rotates about the pivot. In the operating device, the enlarged head is formed at one end of the pivot, and the operating lever can be rotated around an axis parallel to the extension line of the pivot on the side of the enlarged head. in provided on a side end portion of the linkage portion side of the pressing member in said operating lever, bent approximately at right angles to the direction coming close to the end surface of the enlarged diameter head portion of said pivot as Further tip form a substantially crank-shaped bent portion which is bent substantially at right angles to the direction in which extends parallel with the pivot axis, the distal portion forming a parallel to the pivot axis of the crank-shaped bent portion, the pressing The pressing member can be rotated by a rotation operation of the operation lever by being rotatably fitted at a position away from the pivot of the member, and the enlarged head of the crank-shaped bent portion can be rotated. The pivot is prevented from coming off by always restricting the rotation region of the side portion to a range facing and close to a part of the end face of the enlarged head.

(2) In the above item (1), the base of the crank-shaped bent portion of the operation lever is rotatably held by a holding member provided with a stopper piece that prevents the operation lever from moving in a direction away from the pivot.

  According to the first aspect of the present invention, the enlarged head is formed on the pivot connecting the one end of the gas spring to the movable portion, and the crank-shaped bent portion of the operation lever is formed on the end surface of the enlarged head. Because the pivot is prevented from coming off by simple means that always make a part of each face close to each other, as in the past, the pivot is subjected to troublesome processing, and a retaining member such as a spring is attached, There is no need to provide a pivot-preventing member on the movable part side, the number of processes, assembly man-hours, and the number of parts are reduced, and the structure of the movable part is simplified and the appearance is improved.

  According to the second aspect of the present invention, since the crank-shaped bent portion is prevented from moving outward by the stopper piece of the holding member, the pivot is reliably prevented from coming off.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments that are considered to be the best of the present invention will be described below with reference to the drawings.
FIG. 1 is a side view of a chair provided with an embodiment of the present invention, and is composed mainly of a leg (1), a seat (2), a back frame (3), and a backrest (4). .

  The leg body (1) is composed of five radial legs (6) to which casters (5) are attached and leg rods (7) erected at the center thereof, at the upper end of the leg rod (7). The rear end of the support base (8), which has a generally rectangular shape in plan view, is mounted so that the height can be adjusted by a gas spring (not shown) accommodated in the leg rod (7) so that it can be rotated horizontally. It has been.

  The seat body (2) is mounted on a seat frame (9) having a substantially rectangular frame shape in plan view, a seat shell (10) attached to the upper portion thereof, and an inner shell (not shown) on the upper surface thereof. The center part of the front and rear ends of the seat frame (9) is a pair of left and right L-shapes on the front end of the support base (8) and the back frame (3), respectively. Are attached to the upper surfaces of the front end portions of the side rods (12) and (12).

  The backrest (4) is composed of a back shell (13) attached to an upright portion of the back frame (3) and a back cushion (14) attached to the front surface thereof.

  The front end of the side frame (12) of the back frame (3) is connected by a support shaft (15) facing in the left-right direction, and this support shaft (15) is slightly forward of the leg rod (7) on the support base (8). The back frame (3) and the backrest (4) can be tilted back and forth about the support shaft (15).

(12a) is a cover member that covers the vicinity of the bent portion of the outer side surface of the side rod (12).
As shown in FIG. 2, the opposing surfaces of the back frame (3) near the bent portion of the both side collars (12) and the upper end portion are joined by connecting members (16) and (17).

  A gas spring (18) is attached between the back surface of the connecting member (16) and the rear end of the support base (8) as follows.

  As shown in FIGS. 3 and 4 (in FIG. 4, the side bars and the connecting members are not shown), the back surface of the central portion of the inclined plate (16a) facing the oblique vertical direction in the connecting member (16) is viewed from the front. The front surface of the base piece (19a) of the substantially downward U-shaped bracket (19) has a projecting piece (19c) projecting from the upper rear end of the left and right side pieces (19b) (19b), and an inclined plate (16a ) And are fixed by welding.

Between the both side pieces (19b) of the bracket (19), there is a backward U-shaped connecting bracket (21) attached to the upper end of the piston rod (18a) of the gas spring (18), and both side pieces (19b). It is possible to turn by inserting a pivot shaft with an enlarged head (24a), that is, a pivot pin (24) from the side into the left and right through holes (22) and (23). It is pivotally attached to.

  The pivot pin (24) also serves as a pivot shaft of a cam member (30) (details will be described later) sandwiched between the two rear pieces (21a) of the connecting fitting (21).

  The lower end of the cylinder (18b) of the gas spring (18) is pivotally attached to a pair of left and right support pieces (25) projecting from the rear end of the support base (8) by a pivot (26) facing in the left-right direction. (See FIG. 1).

  (27) is an operating device for the gas spring (18), which is a round bar-shaped operating lever (28) having a crank-shaped bent portion (28a) facing left and right and having a rearward-facing crank shape at the left end, and its right end A pivot part (24) is rotatably supported by a pivot pin (24) between a handle part (29) facing forward and fixed to the two rear pieces (21a) of the connecting bracket (21), and an operation lever (28 ) And a cam member made of a hard synthetic resin that is rotated by the above-described method.

The operating lever (28) has a bent portion (28a) in the vicinity of the right end of the horizontal piece (16b) of the connecting member (16) with a screw (31) (see FIG. 3). The U-shaped holding bracket (32) can be rotated, and the bent portion (28a) is inserted through the opening (33) formed in the connecting member (16) and is held on the back side. Has been.

  As shown in FIG. 4, the operation lever (28) has an L-shaped stopper piece (32a) in a plan view in which the right side surface of the base of the bent portion (28a) is connected to the holding metal fitting (32). Movement to the right is restricted by approaching or abutting.

  As shown in the enlarged vertical side view of FIG. 5 and FIG. 7, the cam member (30) has a cylindrical shape with a non-circular cross section in which both left and right side surfaces are opened, and is obliquely forward and upward and rearward from the center in the inside. In the biased position, a cylindrical part (34) having a circular shaft hole (34a) and an elliptical cylindrical part (35) having an elliptical shaft hole (35a) are provided in the cam member (30). It is connected integrally with the peripheral surface.

Inner peripheral surface, and both the cylindrical portion (34) (35) between the outer peripheral surface and the cam member (30) of the cylindrical portion (34) are joined by ribs (36).
The axis on the long axis side of the shaft hole (35a) in the tube portion (35) is aligned with the center of the shaft hole (34a) of the tube portion (34).

  The cam member (30) has the pivot pin (24) rotatably fitted in the circular shaft hole (34a) and the operation lever (28) in the elliptical shaft hole (35a). By loosely fitting the tip (left end) parallel to the pivot pin (24) in the bent portion (28a) of the bent portion (28a) between the two rear pieces (21a) of the connecting bracket (21) It is pivotally mounted.

  An eccentricity that pushes the push rod (37) for operating the control valve by inclining toward the gas spring (18) side obliquely forward and downward of the shaft hole (33) on the outer peripheral surface of the cam member (30). A cam surface (38) is formed, and a lower portion continuous with the cam surface (38) has a concave groove (39) having an arc-shaped cross section into which the top surface of the push rod (37) is fitted, and a stopper step on the counterclockwise side adjacent thereto. A part (40) is formed.

The stopper step (40) is an end protruding from the coupling rod (21) of the piston rod (18a) in the gas spring (18) when the concave groove (39) is fitted to the top surface of the push rod (37). and the outer peripheral edge contact and (41), the maximum rotation amount in the clockwise direction of the cam member (30) is regulated (see FIG. 8).

At this time, the line connecting the center of the shaft hole (35a) and the rotation center of the operation lever (28) is located inward of the center of the pivot pin (24), that is, on the gas spring (18) side. It is supposed to be.
In this way, the operating lever (28) and the grip portion (29) is held in the operation state, and the turning child in opposite directions is eliminated without reason.

  The maximum counterclockwise rotation amount of the cam member (30) is in contact with the stopper piece (42) whose outer peripheral surface faces diagonally backward and downwardly connected to the rear end of the base piece (19a) of the bracket (19). It is regulated by touching.

  This state is the non-operating state shown in FIG. 7, and the upper end portion of the eccentric cam surface (38) of the cam member (30) is slidably contacted or slightly separated from the top end of the push rod (37) and is not pressed. State.

  At this time, the straight line connecting the center of the shaft hole (35a) and the rotation center of the operation lever (28) is opposite to the above, more outward than the center of the pivot pin (24), that is, the gas spring (18 The control lever (28) and the handle (29) are held in the non-operation position.

  In the non-pressed state of the push rod (37) in FIG. 7, the gas spring (18) is locked at an arbitrary expansion / contraction position, so that the tilting of the back frame (3) and the backrest (4) causes the gas spring (18) to tilt. It is performed within the range of the lock position.

  As shown in FIG. 8, when the handle portion (29) is rotated upward, the distal end portion of the bent portion (28a) of the operation lever (28) is rotated downward, so that the cam member (30) is The push rod (37) is gradually pressed by the eccentric cam surface (38).

When the handle portion (29) is rotated to the maximum position where the stopper step portion (40) of the cam member (30) contacts the protruding end portion (41) of the gas spring (18), the cam member (30) is recessed. When the top surface of the push rod (37) is fitted into the groove (39), the push rod (37) is held in a pressed state, and the operation lever (28) and the handle portion (29) are Stopped at the pivot position.

  Thereby, the piston rod (18a) of the gas spring (18) can freely expand and contract, and the backrest (4) can be lightly tilted.

  When the handle portion (29) is turned up and down to the maximum position, the enlarged head (24a) of the pivot pin (24) is bent backwards at the bent portion (28a) of the operating lever (28). In the rotation area of the part (28b), it always faces and is close to it so that the pivot pin (24) is prevented from coming off from the bracket (19) or the connecting bracket (21). (See FIGS. 4 and 6).

  In this way, it is not necessary to fit a snap ring or the like for retaining at the tip of the pivot pin (24), so that the work efficiency during assembly is improved and the number of parts is reduced.

  In the above embodiment, the present invention is applied to the gas snap ring (18) for tilting the backrest (4), but the seat (2) housed in the leg rod (7) is shown. It can also be applied as an operating device for a gas spring for height adjustment.

It is a side view of a chair provided with one embodiment of the present invention. Similarly, it is a disassembled perspective view of a back frame, a gas spring attached to it, and its operating device. Similarly, it is the vertical side view of the principal part of FIG. 2 after an assembly | attachment. It is a top view of an operating device similarly. It is an expansion vertical side view of a cam member. It is the perspective view which looked at the gas spring and the operating device from the right side. It is a center vertical side view at the time of the push rod non-pressing of a gas spring. Similarly, it is a central longitudinal side view when the push rod is pressed.

(1) Leg (fixed part)
(2) Seat
(3) Back frame (movable part)
(4) Backrest
(5) Casters
(6) Leg
(7) Legs
(8) Support base
(9) Seat frame
(10) seat shell
(11) Cushion body
(12) Side rod
(12a) Cover member
(13) Back shell
(14) Back cushion
(15) Spindle
(16) (17) Connecting member
(16a) Inclined plate
(16b) Horizontal piece
(18) Gas spring
(18a) Piston rod
(18b) Cylinder
(19) Bracket
(19a) Base piece
(19b) Side piece
(19c) Projection
(20) Engagement hole
(21) Connecting bracket
(21a) Rear piece
(22) (23) Through hole
(24) Pivot pin (Axis)
(24a) Expanded head
(25) Support piece
(26) Axis
(27) Operating device
(28) Control lever
(28a) Bending part
(28b) Backward bending
(29) Handle part
(30) Cam member (pressing member)
(31) Screw
(32) Retaining bracket
(32a) Stopper piece
(33) Opening
(34) Tube
(34a) Shaft hole
(35) Elliptical cylinder
(35a) Shaft hole
(36) Rib
(37) Push rod
(38) Eccentric cam surface
(39) Groove
(40) Stopper step
(41) Protruding end
(42) Stopper piece

Claims (2)

One end of the control spring push rod protruding from the gas spring is connected to the movable part of the chair by a pivot perpendicular to the axis of the gas spring, and the other end of the gas spring is connected to the chair fixing part. An apparatus for operating a gas spring in a chair that supports and pushes the push rod by a pressing member that is linked to an operating lever and that rotates about the pivot, thereby adjusting the position of the movable part. In
Forming an enlarged head at one end of the pivot, and providing the operation lever so as to be rotatable about an axis parallel to an extension line of the pivot at a side of the enlarged head; the side end portion of the linkage portion side of the pressing member in the operating lever, the pivot is bent substantially at right angles to the direction coming close to the end surface of the enlarged diameter head of a direction to be parallel and further tip the pivot A substantially crank-shaped bent portion bent substantially at a right angle is formed, and a tip portion parallel to the pivot axis in the crank-shaped bent portion is rotatably fitted at a position away from the pivot axis in the pressing member. By combining, it is possible to rotate the pressing member by the rotation operation of the operation lever, and the rotation region of the portion located on the side of the enlarged head at the crank-shaped bent portion is always Close to a part of the end face of the enlarged head By limiting the range of direction, the operating device of the gas spring in the chair, characterized in that it has retained the pivot.   The operation of the gas spring in the chair according to claim 1, wherein the base of the crank-shaped bent portion of the operation lever is rotatably held by a holding member having a stopper piece that prevents the operation lever from moving in a direction away from the pivot axis. apparatus.

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