JP2013106868A - Chair and gas cylinder device for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rocking control gas cylinder device readily mounted to a back frame and readily adjusted.SOLUTION: A gas cylinder device 23 includes a gas cylinder 25, a supporting bracket 31 fixed to a piston rod 25b, an operation member 34 connected to the supporting bracket 31 by a support shaft 32, a case 35 for covering the supporting bracket 31 from outside, and an operation lever 36 rotatably mounted to the case 35. In the operation lever 36, a branch portion 36b provided at the operation member 34 is fitted to a cylindrical portion 34c provided at the operation member 34, and the operation lever 36 is rotationally operated to turn the operation member 34. The gas cylinder device is formed into a unit as a whole with the case 35 as a core member, and thus, assembly thereof is facilitated and adjustment of abutment between a push valve and the operation member 34 is also facilitated.

Description

  The present invention relates to a chair and a gas cylinder device used therefor.

  In a rocking chair in which the backrest tilts backward against the spring means, a gas cylinder is used to control the back tilt of the backrest. The locking control gas cylinder may be built in the base or may be disposed between the base and the back frame.

  As an example of the latter, in Patent Document 1, a rod for a gas cylinder is connected to a downward bracket provided on the back frame by a support shaft, and a cam for operating a push valve of the gas cylinder is connected to the support shaft, It is described that an operating lever is rotatably mounted on the back frame, a crank portion in which the tip of the operating lever is eccentric from the rotational axis is formed, and the crank portion is connected to a cam. In Patent Document 1, when the operation lever is rotated, the cam is switched between a free posture in which the push valve is pushed and a lock posture in which the push valve is not pushed.

Japanese Patent No. 4524094

  In Patent Document 1, the gas cylinder is attached by inserting the support shaft into the bracket while holding the gas cylinder and the cam by hand in a predetermined position, and then the crank portion of the operation lever is camped. Then, the procedure of fixing the pressing member, which becomes the bearing of the operation lever, to the back frame with screws is taken, and there is a problem that the assembly work of the gas cylinder is troublesome.

  In addition, a U-shaped metal fitting is fixed to the rod of the gas cylinder with a nut. By changing the front and rear position of this metal fitting, the push valve is properly adjusted by the cam. In Document 1, since the cam is connected to a bracket provided on the back frame, it is necessary to adjust the position of the metal fitting after assembling each member such as the gas cylinder and the cam, and this adjustment work is also troublesome. .

  The present invention has been made in view of such a current situation, and an object thereof is to provide a gas cylinder device that can be easily assembled and adjusted.

  The present invention includes a gas cylinder of a chair and a chair provided with the same, and the gas cylinder is specified in claims 1 and 2. Of these, the invention according to claim 1 is a gas cylinder device according to the present invention in which the operation portion is incorporated in the gas cylinder and is unitized as a whole. The gas cylinder has a cylinder main body and a piston rod slidably fitted in the cylinder. A push valve for unlocking the rod protrudes from the tip of the rod. A support bracket fixed to the piston rod; an operating lever that is rotated by a person; an operating member that directly or indirectly pushes and retracts the push valve in conjunction with movement of the operating lever; and the bracket And a case attached to the case.

  And in said basic structure, in invention of Claim 1, the said support bracket is a U-shape which has a back plate and a left-right side plate, Comprising: The said back plate is being fixed to the said piston rod. On the other hand, the actuating member is connected to the left and right side plates of the support bracket so as to be pivotable by a support shaft, and is free to push the push valve of the piston rod by rotating about the axis of the support shaft. The posture can be freely changed to a locked posture for holding the push valve in the return state.

  Furthermore, in the invention of claim 1, the case is held so as not to be detached from the left and right side plates of the support bracket in a state of covering the operation member, and the operation lever is rotatably held by the case. The operating lever is provided with a drive unit that switches the operating member between a free posture and a locked posture by rotation thereof.

  The invention of claim 2 embodies the invention of claim 1, and the present invention includes a relay piece interposed between the operation member and the push valve inside the case, and the rotation of the operation member. So as to bend and deform.

  The invention of claim 3 relates to a chair, the chair comprising a base provided at the upper end of the leg support, a back frame connected to the base so as to be tiltable rearwardly, and a backrest supported by the back frame. Or the gas cylinder apparatus described in 2 is provided. The base end of the cylinder body is pivotally connected to the base, the gas cylinder case is fitted in a recess in the back frame, and the support shaft is connected to the left and right sides of the case. A bearing hole that is exposed to the outside and in which the left and right exposed portions of the support shaft are fitted is provided in the back frame, and a resin receiving member that supports the support shaft is disposed in the bearing hole.

  In the present invention, since the gas cylinder, the operating lever, and the operating member are unitized through the case, it is not possible to insert the support shaft while holding the member by hand when assembling to the chair or the like. It is not necessary and can be assembled very easily. In addition, since the relationship between the rod and the operating member can be set in advance in a place where it is easy to perform work such as on a table, the workability is markedly improved compared to adjustment after assembling the chair as in Patent Document 1. It can be improved and the burden on the operator can be reduced. In the case of this second aspect, it is more preferable that the relay piece is provided with a function of maintaining the posture of the operating member as in the embodiment.

  In the case of Patent Document 1, since the push valve is directly pushed by the cam, the bending force is strongly applied to the push valve when moving to the cam surface of the cam, and the smoothness of operation is lacking or the gas cylinder breaks down. May be easier. On the other hand, when the configuration of claim 2 of the present application is adopted, the force due to the rotation of the actuating member can be applied in the axial direction of the push valve by utilizing the bending rotation of the relay piece, so that the operation can be performed smoothly. In addition, the durability of the gas cylinder can be improved.

  If the structure of Claim 3 is employ | adopted, since a case and a spindle will be set only by fitting in a back frame, the assembly | attachment of a gas cylinder can be performed very easily. The support shaft is preferably made of metal such as steel from the viewpoint of strength. However, even if the support shaft is made of metal and the back frame is made of metal such as aluminum die-cast, the support shaft is made of resin. Since it is supported by the receiving member, it is possible to prevent or remarkably suppress the rubbing noise and collision noise between metals.

It is a figure which shows the external appearance of the chair which concerns on embodiment, (A) is a perspective view, (B) is a side view. It is a separation perspective view of a chair. (A) is a perspective view of the periphery of a gas cylinder device, and (B) is a partially separated perspective view seen from below. (A) is the perspective view which looked at the gas cylinder and the base from the lower part, (B) is the isolation | separation perspective view of a gas cylinder and a base, (B) is the fragmentary perspective view of a gas cylinder apparatus. (A) is a perspective view in a state where a gas cylinder is attached, and (B) is an exploded perspective view of a back frame and a gas cylinder device. (A) is the partial isolation | separation perspective view of a receiving stopper and a back frame, (B) is the perspective view which looked at the back frame from back lower direction. (A) is a separated perspective view of the gas cylinder device, and (B) is a sectional view taken along the line VIIB-VIIB in FIG. 6 (A). The perspective view in the unfolded state of the case, (B) is a perspective view in a state in which the case is closed. (A) (B) is the isolation | separation perspective view of the principal part. (A) is a separated side view, (B) is a perspective view of an operation member, and (C) is a perspective view of a case. (A) is a vertical cross-sectional side view of the central part of the main part in the locked state, (B) is a vertical side view of the central part of the main part in the free state, and (C) is a view showing the relay piece. (A) is the perspective view which shows the attachment structure of an operation lever, (B) is the perspective view which looked at the bearing cover from the downward direction. It is a perspective view which shows 2nd Embodiment. It is a perspective view which shows 3rd Embodiment. It is a fragmentary perspective view of the lower cover which covers a base from the bottom.

  Next, an embodiment of the present invention will be described with reference to the drawings. In the following description, the words “front and rear” and “left and right” are used to specify the direction, but the words on the front and rear and right and left are based on the person who is seated. The front view direction is the direction facing the seated person, and therefore the left and right in the front view are opposite to the left and right viewed from the seated person.

(1). Outline of Chair First, an outline of a chair will be described mainly with reference to FIGS. This embodiment is applied to a swivel chair often used for office work or the like. As shown in FIG. It has a base 3, a seat 4 arranged on the base 3, and a backrest 5 on which a seated person can lean.

  A resin seat outer shell (seat receiving member) 6 that supports the seat 4 is disposed on the base 3, and the seat outer shell 6 is attached thereto. The seat 4 has a resin seat inner shell (seat plate) and a seat cushion material arranged on the upper surface thereof.

  As shown in FIG. 2, a back frame 7 is connected to the base 3 by a left and right horizontally long pipe-made first shaft 8 so as to be tiltable rearwardly, and a back outer shell 9 is attached to the back frame 7. As can be seen from FIG. 2, the back frame 7 includes left and right side arms 10 that extend substantially in the front-rear direction, a laterally long rear portion 11 that is integrally connected to the rear end, and a back support that rises from the rear end of the rear portion 11. The back outer shell 9 is attached to the back strut portion 12. A backrest 5 is attached to the back outer shell 9 and the back column portion 12. In FIG. 2A, the back inner shell 13 which is a main element of the backrest 5 is displayed.

  As can be understood from FIGS. 2 and 3, the front portion of the seat outer shell 6 is connected to the base 3 by a pipe-made second shaft 14, and the rear portion of the seat outer shell 6 is a third shaft provided on the back frame 7. 15 is connected. As shown in FIG. 2B, the base 3 is covered with an upper cover 16 and a lower cover 17 from above and below. As shown in FIG. 3 (B), a column support cylinder 18 is welded to the rear portion of the base 3, and the leg column 1 is fitted to the column support cylinder 18 from below.

  As shown in FIG. 3 (B), the first shaft 8 is fixed to the front side of the column receiving cylinder 19 on the lower surface of the rear portion of the base 3 by welding. On the other hand, the front end portion 10 a of the left and right side arms 10 constituting the back frame 7 is a bearing portion connected to the first shaft 8. As shown in FIG. 3, the second shaft 14 is slidably fitted back and forth on a bush 20 attached to the front portion of the base 3. The backward movement of the second shaft 14 is elastically supported by the coil-type rocking spring 21.

  As clearly shown in FIG. 4 (B), a base bracket 21 is formed in the base 3 by bending the front portion downward and forming a front plate. While being welded, the front end of the base bracket 21 supports the rear spring receiver 22 and the elastic strength adjusting wedge member 23.

  In the chair of this embodiment, when a person leans against the backrest 5, the seat outer shell 6 (and thus the seat 4) tilts backward while pulling back by the third shaft 15. The locking of the backrest 5 is controlled by a gas cylinder device 23 disposed between the base 3 and the back frame 7. That is, by the gas cylinder device 23, the backrest 5 is switched between a free state in which the backrest 5 freely tilts and a locked state in which the backrest 5 is held at an arbitrary rearward tilt angle. Hereinafter, the gas cylinder device 23 will be described.

(2). Overall Configuration of Gas Cylinder Device Next, the gas cylinder device 23 will be described with reference to FIGS. For example, as shown in FIG. 4, the gas cylinder device 23 includes a gas cylinder 25 and an operation unit 26. The gas cylinder 25 is conventionally known, and includes a cylinder body 25a and a stone rod 25b slidably fitted on the cylinder body 25a. A horizontally long pivot pin 27 is connected to the base bracket 21. Therefore, the gas cylinder 25 rotates up and down around the pivot pin 27. A downwardly facing piece 21a is provided at the rear end of the base bracket 21, and a U-shaped bearing plate 28 is welded thereto.

  A resin stopper 29 against which the seat outer shell 6 hits from above is provided at the rear end of the base bracket 21. The stopper 29 causes the seat outer shell 6 to hit the stopper 29, so that the maximum back of the backrest 5 can be obtained. Tilt angle is specified.

  As shown in FIG. 3, the left and right side frames 10 constituting the back frame 7 are connected to each other by a horizontally long joint portion 7 a at the front and rear middle portions, and a third shaft 15 is integrally provided on the joint portion 7 a. However, as shown in FIG. 3B, the lower surface portion of the joint portion 7a is composed of left and right laterally long ribs 7b protruding downward so that the gas cylinder 25 does not hit the group of ribs 7b. An escape groove 7c opened downward is formed.

  As shown in FIG. 4, the operation portion 26 is inserted into a U-shaped support bracket 31 fixed to the front end portion of the piston rod 25 b of the gas cylinder 25 with front and rear nuts 30, and the left and right side plates 31 a of the support bracket 31. A support shaft 32, an actuating member 34 for pushing the push valve 33 protruding from the tip of the piston rod 25b, a case 35 for covering the support bracket 31 from behind, and an operating lever 36 for rotating manually by a person. It has. The case 35 has a substantially side trapezoidal shape in which the vertical width slightly decreases as it goes backward (thus, it is easy to fit into the back frame 7). Further, the operation lever 36 is provided with a handle portion 36a to which a person touches.

  The support shaft 32 is exposed to the left and right outer sides of the support bracket 31. On both the left and right sides of the support bracket 31, resin receiving stoppers 37 that support the exposed portion of the support shaft 32 from substantially below and have a retaining function. It is arranged. The receiving stopper 37 can be configured as a part of the gas cylinder device 23 by being integrally attached to the case 35, or may be configured as a separate member from the gas cylinder device 23. In the present embodiment, the receiving stopper 37 is a separate member from the gas cylinder device 23 and is not part of the unit.

  As shown in FIGS. 5 and 6, the rear portion 11 of the back frame 7 is formed with a center recess 39 into which the case 35 is fitted from the front, and a side recess 40 into which the support shaft 32 and the receiving stopper 37 are fitted. ing. Both recesses 49 and 40 communicate with each other. Although the case 35 is not in contact with the inner surface of the center recess 39, as shown in FIG. 7B, the support shaft 32 is in contact with the inner surface of the side recess 40 and the receiving stopper 37 from below. It is supported by. Accordingly, the back load caused by the locking acts on the support shaft 32.

  As clearly shown in FIG. 6 (A), the receiving stopper has a dogleg shape in a side view, and therefore, the lower surface of the side recess 40 has a dogleg shape. A protrusion 37a is provided on the lower surface of the receiving stopper 37, while a groove 40a into which the protrusion 37a is fitted is formed in the side recess 40. The receiving stopper 37 is held in the side recess 40 so as not to be laterally displaced by the fitting of the protrusion 37a and the groove 40a.

  In addition, a hook-like engagement claw 41 that protrudes downward from the rear end of the receiving stopper 37 is provided rearwardly, while an engagement hole 42 into which the engagement claw 41 is fitted is provided at the back of the side recess 40. An engagement step 42a is formed in the engagement hole 42 so that the engagement claw 41 is hooked and engaged to hold the receiving stopper 37 so that it cannot be removed forward. The engaging claw 41 is open on the rear surface of the back frame 7.

  As shown in FIG. 9, the operation member 34 is disposed inside the support bracket 31 in a state of being fitted to the support shaft 32. On the other hand, the operating lever 36 is positioned obliquely above the operating member 34, and the operating lever 36 is formed with a branch portion (backward projecting portion) 36b extending obliquely rearward and downward as the drive portion recited in the claims, The branch part 36 a is fitted into a cylindrical part 34 c formed on the operating member 34. Accordingly, by rotating the operation lever 36, the operating member 34 can be changed between a free posture and a locked posture.

(3). Case and Actuating Member The case 35 includes a first portion 35a that covers most of the support bracket 31 from behind, and a second portion 35b that is located on the left side of the first portion 35a in a front view of the chair. As shown in FIG. 8, both are integrally connected by a hinge part 35c connected to the rear end thereof. The case 35 is molded in the unfolded state as shown in FIG. 8 (A). In use, as shown in FIG. 8 (B), the two portions 354a, 35b is overlapped. In FIG. 9, both parts 35a and 35b are displayed in a separated state.

  As can be understood from FIG. 9A, a first recess 35 in which one side plate 31a of the support bracket 31 is fitted in a portion of the first portion 35a constituting the case 35 on the side opposite to the second portion 35b. 43, and a cylindrical portion 44 into which the support shaft 32 is fitted is formed inside the first portion 35a. In addition, a first projecting portion 45 that protrudes to the right in front view is formed on the upper portion of the first portion 35a, and one receiving stopper 37 is set to be positioned below the first projecting portion 45. In addition, a bearing recess 46 that supports the tip of the operation lever 36 is formed in the first projecting portion 45 (see also FIG. 8A). The second portion 35b is provided with a hole 35 'through which the support shaft 32 passes.

  On the other hand, as shown in FIG. 9B, a second recess 47 that fits into the other side plate 31a of the support bracket 31 is formed on the opposite side of the second portion 35b to the first portion 35a. Further, the second portion 35 b is formed with a second overhang portion 48 extending so as to be continuous with the first overhang portion 45 of the first portion 35 a, and the operation lever 36 is provided in a portion including the second overhang portion 48. Is formed with a lever support groove 49 that fits against the elasticity.

  As shown in FIG. 8, a protrusion 50 and a fitting hole 51 into which the protrusion 50 fits are formed as positioning means at the front lower end of the first portion 35a and the second portion 35b. Although the protrusion 50 is formed in the first portion 35a and the fitting hole 51 is formed in the second portion 35b, the arrangement can be reversed. It is also possible to employ other positioning means.

  As can be understood from FIG. 8A, a superposition portion 52 that covers the front corner portion of the upper portion of the second portion 35b from the front is formed at the front portion and the top portion of the first portion 35a. An inward claw 53 is formed on the inner surface of the first portion, and a step portion 543 into which the claw 53 is fitted is formed in the second portion 35b. A recessed portion 55 is formed at the base portion of the overlapping portion 52 in the first portion 35a, and a protrusion 56 that fits into the recessed portion 55 is formed in the second portion 35b. The claw 53 and the stepped portion, and the recessed portion 55 and the projection 56 are positioning means (connecting means).

  As shown in FIG. 11, a relay piece 57 interposed between the push valve 33 and the actuating member 34 is integrally formed in the first portion 35a so as to extend upward from the bottom surface of the first portion 35a. ing. For example, as shown in FIG. 10A, in order to facilitate the die cutting of the relay piece 57, the side plate of the first portion 35a has a die cutting hole 57 '.

  The relay piece 57 rises in a direction perpendicular to the axis O of the gas cylinder 25, but from the middle of the relay piece 57 is an inclined portion 57a inclined backward, and the tip of the inclined portion 57 is the push valve 33 and the actuating member 34. The relay portion 57b is sandwiched between the two. The front surface of the relay portion 57b is flat so as to be in surface contact with the tip surface of the push valve 33, and the rear surface of the relay portion 57b is recessed in a backward-facing concave shape. Even if the push valve 33 moves back and forth, the relay portion 57b of the relay piece 57 is always in contact with the front end surface of the push valve 33.

  On the other hand, the first projecting portion 34a into which the relay portion 57 of the relay piece 57 is fitted in the state where the push valve 33 is freely extended as shown in FIG. The second protrusion 34c into which the relay portion 57 of the relay piece 57 is fitted, the intermediate surface 34b continuous to both the protrusions 34a and 34c, and the relief surface continuous to the lower side of the second protrusion 34b. 34d. In addition, the operating member 34 is formed with a receiving tube portion 34e into which the branch portion 36b of the operation lever 36 is fitted, and a stopper wall 34f against which the relay piece 57 comes into contact when the relay piece 57 falls down.

(4) Operation As shown in FIG. 11A, in the locked state in which the gas cylinder 25 freely extends the push valve 33, the relay piece 57 does not bend and deform, and the relay portion 57b has the first protrusion 34a. And the inclined portion 57a overlaps the intermediate surface 34b. Therefore, the operating member 34 is held in a locked state in a stable state.

  That is, since the push valve 33 is urged forward by the elastic force of the gas (or spring) to the gas cylinder 25, the actuating member 34 cannot be rotated to a free posture without applying a certain amount of force. Since the first protrusion 34a is fitted in the recess on the rear surface of the relay portion 57b of the relay piece 57, the actuating member 34 cannot be rotated in the free posture and the main body direction (in the direction opposite to the free posture). Is also regulated by the operation member 34 hitting the lower inner surface of the first portion 35a).

  On the other hand, when the operation lever 36 is rotated to rotate (rotate) the operating member 34 in a free posture, the push valve 33 moves backward by the relay piece 57 being pushed forward by the second protrusion 34c, and The second protrusion 34 b is fitted in the recess of the relay portion 57 b in the relay piece 57. Thereby, the operation member 34 is stably held in a free posture.

  That is, in the state where the push valve 33 is retracted, the second protrusion 34c of the operating member 34 is fitted into the relay portion 57b of the relay piece 57. In this state, the relay portion 57b of the relay piece 57 is the push valve. 33 is in close contact with the front end surface of the gas cylinder 25 and the relay portion 57b and the second protrusion 3b of the relay piece 57 are located behind the front end surface of the push valve 33 when viewed from the direction of the axis O of the gas cylinder 25. The operating member 34 is held in a stable state.

  More specifically, in order to rotate the actuating member 34 from the free position to the locked position, the second protrusion 34c of the actuating member 34 has to get over the relay part 57b of the relay piece 57, so that a certain amount of force is not applied. On the contrary, when the operation member 34 is rotated from the free posture to the opposite direction to the lock posture, the relay portion 57b of the relay piece 57 is supported by the relief surface 34d of the operation member 34. Therefore, the state in which the relay piece 57 is supported by the operation member 34 is maintained (the rotation from the free posture to the side opposite to the lock posture causes the operation member 34 to hit the upper inner surface of the first portion 35a. It is regulated by.)

  Now, there is a considerable difference between the distance from the axial center of the actuating member 34 to the first projecting portion 34a and the distance to the second projecting portion 34c. In other words, when the push valve 33 is pushed by the intermediate surface 34b, a large bending force acts on the push valve 33. Therefore, a large force is required for the operation and the durability of the gas cylinder 25 is lowered. In order to avoid this, it is necessary to increase the circumferential distance between the first protrusion 34a and the second protrusion 34c to loosen the inclination angle of the intermediate surface 34b. As a whole, the cylinder device is increased in size.

  On the other hand, when the push valve 33 is operated via the relay piece 57 as in the present embodiment, the rotation of the operating member 34 with the first protrusion 34a and the second protrusion 34c approaching in the circumferential direction. Therefore, the push valve 33 can be smoothly pushed and returned while being a compact actuating member 34. The relay piece 57 can be manufactured as a separate member from the first portion 35 a (case) and can be attached to the case 35 or the support shaft 32. However, if the first portion 35a (case) is integrally formed as in the present embodiment, there is an advantage that the structure can be simplified and the labor of member management can be reduced.

(5) Operation lever / others The operation lever 36 is rotatably held at both left and right end portions of the rear portion 11 of the back frame 7 and cannot be detached, and its mounting structure is shown in FIG. That is, as shown in FIG. 12, the end of the operating lever 36 is covered from above with a semicircular bearing cover 59 having a front and rear flange portion 59a at the lower end, and the bearing cover 59 is provided at both front and rear ends. By fitting the horizontal engaging claw 60 into the dovetail groove portion 61 formed in the rear portion 11 of the back frame 7 from the left and right inner sides, it is held so as not to be detached.

  More precisely, the engaging claw 60 is formed in a cantilever state extending toward the outside of the back frame 7, and has an upward flange 60 a formed at the tip thereof, while the front side of the dovetail groove 61 is formed. A lip 61a is formed on the opening edge, and the bearing cover 59 is held in a non-detachable manner by fitting the upward flange portion 60a into a notch hole 62 formed in the lip 61a. In addition, a forward projection 61b is provided on the back side of the dovetail 61, and the engagement claw 60 on the back side is engaged with the forward projection 61b from below.

  On the outer back of the dovetail groove 61, left and right longitudinal ribs 61c are provided, and on the lower surface of the bearing cover 59, grooves 59b that fit into the ribs 61c are formed. A groove 63 in which the operation lever 36 is fitted is formed in the back frame 7, and a flange portion 59 a of the bearing cover 59 is fitted in the dovetail 61. For this reason, the operation lever 36 is held so as not to be loose.

  As described above, the gas cylinder device 23 is unitized as a whole with the case 35 as a core member. For this reason, the attachment to the back frame 7 is very simple. When the operation lever 36 is attached to the back frame 7 with a fitting-type bearing cover 59 as in the present embodiment, the assembly becomes easier.

  As shown in FIG. 7, a trapezoidal stopper protrusion 36 c that protrudes upward is provided at a portion of the operation lever 36 that is covered with the bearing cover 59, while the stopper protrusion 36 c is provided inside the bearing cover 59. A stopper groove (bearing groove) 59d into which 36c is fitted is formed. A pair of stopper grooves 59d are provided so that the side surfaces of the stopper projections 36c selectively come into contact with each other regardless of whether the operation lever 36 is in the locked position or in the free position. The dynamic posture is regulated.

  In other words, the rotation posture of the operation lever 36 is also regulated by the branch portion 36b, but the operation lever 36 is made of resin and has a certain length and may be twisted by rotation. In order to restrict the rotation angle, a stopper projection 36d and a stopper groove 59d are formed. Further, the stopper projection 36c hits the inner end face 59c of the stopper groove 59d, thereby causing the operation lever 36 to come out outward. Restriction of the inward movement of the operation lever 36 is performed by the tip of the operation lever 36 coming into contact with the end plate of the first projecting portion 45 in the case 35.

  Now, since the case has a plurality of functions such as a cover function of the actuating member and a support function of the operation lever, the shape may be complicated. Therefore, the case may be preferably composed of a plurality of parts. However, if a plurality of parts are manufactured as separate members, it may take time to manage the members or cause assembly errors.

  In this regard, when the case 35 of the embodiment of the present application is configured by two (plural) members 35a and 35c connected by the hinge portion 35c, the portion having different functions is a single member. While having an excellent case, it is possible to prevent an increase in labor for member management and to prevent assembly errors. Of course, it may be manufactured as a separate member. When separate members are used, the overlapping members can be easily connected by connecting the engaging claws and the engaging holes (or the engaging claws and the engaging claws) with the engaging means.

  The gas cylinder device 23 is attached in the following procedure. That is, first, the case 35 of the gas cylinder device 23 is fitted into the four center recesses of the back frame 7, and then the cylinder main body 25 a is connected to the bearing plate 28 by the pivot pin 27. Next, the receiving stopper 37 is fitted into the side recess 41 of the back frame 7 and attached, and then the bearing cover 59 is attached to the back frame 7 (whichever is first attached to the receiving stopper 37 or the bearing cover 59). You may go.) Thus, the gas cylinder device 23 can be easily assembled.

(6). Modified Example of Bearing Cover FIG. 13 shows a second embodiment which is a modified example of the bearing cover 59. The bearing cover 59 of the second embodiment has many parts in common with those of the first embodiment, and therefore parts having common functions are given the same reference numerals.

  Also in this bearing cover 59, the flange portion 59a is fitted into the dovetail groove 61 of the back frame 7 from the inside, but unlike the first embodiment, the dovetail groove 61 is opened in the left-right direction. In order to prevent the 59 from coming off outwardly, a protruding portion 59e protruding in the front-rear direction is formed at the inner end, and this is applied to the inner end of the lip 61a. Further, the engaging claw 60 is fitted into an engaging hole 61 b formed in the bottom surface of the dovetail 61.

  Similarly to the first embodiment, the operation lever 36 is provided with a trapezoidal stopper projection 36c for restricting the rotation range thereof, while the bearing cover 59 has a stopper groove into which the stopper projection 36c is fitted. 59d is provided so that the stopper projection 36c selectively contacts either inner surface 59d ', 59d "of the stopper groove 59d.

  As shown in FIG. 7B, when the back frame 7 rotates about the pivot pin 27, the gas cylinder device 23 also rotates together. However, the relative position of the support shaft 32 with respect to the back frame 7 However, since the support shaft 32 and the operation lever 36 are spaced apart from each other, the operation lever 36 tends to be separated from the back frame 7 by the rotation of the operation lever 36. That is, while the distance between the operation lever 36 and the support shaft 32 is constant, the distance from the pivot pin 27 to the operation lever 36 is smaller than the distance from the support pin 27 to the support shaft 32, and thus the operation lever 36. In order to rotate around the pivot pin 27, it must escape upward relative to the back frame 7.

  As described above, as a means for allowing the operation lever 36 to relatively move away from the back frame 7 when the back frame 7 is rotated, the clearance between the bearing cover 59 and the operation lever 36 may be increased. However, if the clearance is increased too much, the play in the front direction will occur. When the clearance is small, the distance between the support shaft 32 and the operation lever 36 must be reduced. Then, the length of the branch portion 36b of the operation lever 36 is shortened, and the force required to operate the gas cylinder 25 is increased. growing.

  Therefore, in the second embodiment, as shown in FIG. 13, the stopper groove 59 d of the bearing cover 59 is formed in an elongated hole that is deepened along the thawing locus drawn by the operation lever 36 during locking. . As a result, the operation lever 36 can be rotated easily while suppressing the backlash of the operation lever 36 in the front-rear direction.

(7). Other Embodiments Next, another embodiment shown in FIG. 14 will be described. This embodiment is also basically the same as the first embodiment, and the gas cylinder device 23 includes a case 35. Although not shown, a support bracket 31 similar to that of the first embodiment is fixed to the tip of the piston rod 25b, and a case 35 is attached to the support bracket 31. The support shaft 32 is inserted into the case 35. Further, an operating member 34 through which the support shaft 32 is inserted is disposed inside the case 35, and the operating member 34 has a pressing portion 34a and a relief surface 34d.

  On the other hand, the operation lever 36 is rotatably held in a bearing hole 65 provided at the upper end of the case 35, and the tip end portion of the support shaft 32 is bent into a U shape having a drive portion 32 c parallel to the support shaft 32. The drive portion 32c is fitted into the elongated hole 66 provided in the operating member 34 from the side. Accordingly, when the operation lever 36 is rotated, the operation member 34 is rotated, and the gas cylinder 25 is switched between the lock posture and the free posture. Although not shown, a pressing member that holds the operation lever 36 so as not to be detached is attached to the upper surface of the case 35. Receiving stoppers 37 are disposed on the left and right sides of the case 35.

(8) Supplement Now, oil is sealed in the gas cylinder 25, but the oil may leak down along the cylinder body and stain the floor. As shown in FIG. 15, this point can be dealt with by providing an oil receiving portion 17a located below the rear end portion of the cylinder body 25a at the rear portion of the lower cover 17 that covers the base 3 from below.

  The gas cylinder device of the present invention can be arranged on the base.

  The present invention can be embodied in a chair. Therefore, it can be used industrially.

3 Base 4 Seats 7 Back Frame 10 Back Frame Side Arm 11 Rear Frame Rear Part 21 Base Bracket 23 Gas Cylinder Device 24 Operation Unit 25 Gas Cylinder 25a Cylinder Body 25b Piston Rod 31 Support Bracket 31a Side Plate 32 Support Shaft 33 Push Valve 34 Actuating member 35 Case 35a First part 35b Second part 35c Hinge part 36 Operation lever 36a Branch part as drive part 37 Receiving stopper 39 Center recess 40 Side recess 57 Relay piece

Claims (3)

A configuration in which an operation unit is incorporated in a gas cylinder,
The gas cylinder has a cylinder main body and a piston rod slidably fitted thereto, and a push valve for unlocking projects from the tip of the rod,
The operation unit includes a support bracket fixed to the piston rod, an operation lever that is rotated by a person, and an operation that pushes or retracts the push valve directly or indirectly in conjunction with movement of the operation lever. A member and a case attached to the support bracket;
The support bracket has a U shape having a back plate and left and right side plates, and the back plate is fixed to the piston rod,
The actuating member is connected to the left and right side plates of the support bracket so as to be rotatable about a support shaft, and is rotated around the axis of the support shaft to push the push valve of the piston rod and push the free posture. The posture can be freely changed to the locked posture that holds the valve in the return state,
Further, the case is held so as not to be detached from the left and right side plates of the support bracket in a state of covering the operation member, the operation lever is rotatably held in the case, and the operation lever A drive unit that switches the operating member between a free posture and a locked posture by the rotation;
Chair gas cylinder device. Inside the case, a relay piece interposed between the operating member and the push valve is provided so as to bend and deform by the rotation of the operating member.
A gas cylinder device for a chair according to claim 1. A base provided at an upper end of the leg support, a back frame connected to the base so as to be tiltable rearwardly, a backrest supported by the back frame, and the gas cylinder device according to claim 1 or 2. ,
A base end portion of the cylinder body is rotatably connected to the base, a case of the gas cylinder is fitted in a recess of the back frame, and the support shaft is disposed on the left and right outer sides of the case. It is exposed, the back frame is provided with a bearing hole into which the left and right exposed portions of the support shaft are fitted, and a resin receiving member that supports the support shaft is disposed in the bearing hole.
Chair.

Images