JP4877936B2 - Headrest device - Google Patents

Description

  The present invention relates to a headrest device in which, for example, a headrest is attached to a frame extending upward from a backrest of a chair or the like so that the front-rear position can be adjusted.

A headrest device provided with a headrest whose front and rear positions can be adjusted is described in, for example, Patent Documents 1 to 3, and is well known.
JP-A-5-176825 JP 2003-102585 A JP 2004-202062 A

  In the headrest device described in Patent Document 1, when adjusting the front / rear position of the headrest, each time the operation handle is rotated, the lock mechanism is temporarily unlocked, and the operation handle is again turned on. Since it is necessary to rotate and lock, adjustment of the front-rear position of the headrest is troublesome.

  In addition, the structure of the front / rear position adjusting mechanism and the lock mechanism is complicated and the number of parts is large, which increases the cost and increases the number of assembly steps.

  In both the headrest devices described in Patent Documents 2 and 3, since the headrest is attached to the headrest frame so as to be wearable and rotatable, there is little possibility that the above-described problems will occur.

  However, a flat washer-like friction material is inserted into the pivot part of the headrest frame and the headrest, and this is tightened with bolts and nuts to give friction resistance to each pivot part. Therefore, it is difficult to moderately adjust the friction force by adjusting the bolt tightening force.

  That is, since the friction material is a flat washer and the frictional contact area is small, if the bolt tightening force is too weak, the frictional force will also be small and the headrest will easily rotate back and forth, or the headrest will wobble. There is a fear.

  In order to prevent this, if the bolt is tightened too much, the frictional force becomes too large and it becomes difficult to rotate the headrest back and forth.

  The present invention has been made in view of the above problems, and has a simple structure, a small number of parts, and an appropriate frictional force to stably rotate the headrest back and forth so that the front and rear positions thereof can be obtained. An object of the present invention is to provide a headrest device that can be easily adjusted.

According to the present invention, the above problem is solved as follows.
(1) In a headrest device in which a headrest is attached to a frame extending upward from the backrest so that the headrest can be pivoted back and forth with a pivot axis facing in the left-right direction, either the frame or the headrest has a left-right direction A frictional force imparting member having a shaft hole facing the surface is provided in a relatively non-rotatable manner. Similarly, a frictional force imparting member having a shaft hole facing in the left-right direction cannot be rotated relative to the frictional force imparting member. And a conical portion that complements the tapered hole provided in the other of the opposing portions in the tapered hole provided in one of the opposing portions of the frictional force applying member and the frictional force applying member. And the pivot shaft is inserted into shaft holes of the frictional force applying member and the frictional force applying member, and the frictional force applying member and the frictional force applying member are connected to a tapered hole and a conical portion. of As surface touch can be relatively friction rotating, together by clamping means.

(2) In the above item (1), the frictional force applying member is formed of a hard material, and the frictional force applying member is formed of a softer material than the frictional force applying member.

(3) In the above item (1), the frictional force imparting member is formed of a hard material, and only the contact surface of the frictional force imparting member with the frictional force imparting member is softer than the frictional force imparting member. It is made of a new material.

(4) In the above item (2) or (3), the frictional force imparting member or the contact surface with the frictional force imparting member is made of an elastomer, and the frictional force imparting member is made of a hard synthetic resin.

(5) In any one of the above items (1) to (4), the tightening means has a pivot that faces in the left-right direction, an enlarged head on one end side, and the pivot on the other end from the pivot. A stepped bolt having a small-diameter male thread part connected thereto, and a side end face of either the frictional force imparting member or the frictional force imparting member screwed into the male threaded part and fitted to the pivot. It shall consist of a pressing nut which can be pressed.

(6) In any one of the above items (1) to (5), a support cylinder facing in the left-right direction and having both ends opened is provided on the front surface of the frame, and a frictional force is applied in the hollow hole of the support cylinder. The member, the frictional force applying member, and the tightening means are accommodated so as to prevent rotation of one of the frictional force applying member and the frictional force applying member and allow the other rotation.

(7) In the above item (6), on the inner surface of the hollow hole of the support cylinder and the outer peripheral surface of the frictional force imparting member or the frictional force imparting member, protrusions and concave grooves facing each other in the axial direction are provided.

(8) In the above item (6) or (7), a mounting piece extending toward the support cylinder is provided on the rear surface of the headrest, and the rear end portion of the mounting piece is provided on the outer peripheral surface of the support cylinder. In addition, the mounting hole that is loosely fitted in the mounting hole that communicates with the hollow hole and that is provided at the rear end of the mounting piece is attached to the frictional force imparting member or the frictional force imparting member accommodated in the support cylinder so as not to be relatively rotatable. Fit.

(9) In the above item (8), axially projecting protrusions and concave grooves that are fitted to each other are provided on the inner surface of the mounting hole and the outer peripheral surface of the frictional force imparting member or the frictional force imparting member.

  According to the first aspect of the present invention, the tapered portion and the conical portion are provided in the opposing portion between the frictional force applying member and the frictional force applying member provided in the frame and the headrest so as not to rotate relative to each other, and these are fitted to each other. Thus, the frictional contact areas are relatively large, and the conical portion comes into strong contact with the inner surface of the tapered hole by the wedge action.

Therefore, it is relatively easy to adjust the frictional force of the contact surface between the tapered hole and the conical portion by the tightening means, and a large frictional force can be obtained even with a small tightening force. Therefore, the front and rear positions can be easily and continuously adjusted, and after the adjustment, the headrest does not wobble or rotate unnaturally.
Further, since the structure is simple and the number of parts is extremely small, the cost and the number of assembly steps can be reduced.

According to the second aspect of the present invention, when the tightening means is tightened, the frictional force applying member side is strongly pressed against the frictional force applying member while elastically deforming in the direction of diameter expansion or contraction. The frictional resistance of the headrest increases, and the headrest is more stably held after the front-rear position adjustment.
Moreover, since the impact at the time of rotation of a headrest and the use is absorbed by the elastic deformation of a frictional force provision member, comfortable usability is obtained.

  According to the third aspect of the present invention, only the contact surface of the frictional force imparting member with the frictional force imparting member is made of a softer material than the frictional force imparting member. Even if the force applying member rotates relative to each other and the contact surface between the tapered hole and the conical portion frictionally rotates, the frictional resistance prevents the entire frictional force applying member from being twisted.

  According to the invention of claim 4, the frictional force imparting member and the frictional force imparting member can be easily formed integrally, and the hardness of the contact surface with the frictional force imparting member or the frictional force imparting member is It can be easily changed by appropriately selecting an elastomer material according to the purpose of use.

According to the fifth aspect of the present invention, since the pivot is formed on the stepped bolt of the tightening means and they are shared, the number of parts is reduced and the assembly is facilitated.
Further, the stepped bolt is inserted into the shaft hole of the frictional force applying member and the frictional force applying member and is tightened in the axial direction by the flanged nut, so that the contact surface between the tapered hole and the conical portion is pressed uniformly. become.

  According to the sixth aspect of the present invention, the frictional force applying member, the frictional force applying member, and the fastening means are concealed by the support tube and are not exposed to the outside, so that the appearance is improved.

  According to the seventh aspect of the present invention, the frictional force imparting member or the frictional force imparting member is fitted into the support cylinder so that the protrusions and the concave grooves are aligned with each other from the opening at the side end. Only by this, the rotation of the frictional force applying member or the frictional force applying member with respect to the support cylinder can be easily prevented.

  According to the eighth aspect of the invention, the headrest can be easily and well attached to the frame-side support cylinder via the attachment piece.

  According to the ninth aspect of the present invention, the frictional force can be applied to the frictional force applying member or the frictional force applying member by simply fitting the mounting holes of the mounting pieces so that the protrusions and the concave grooves are aligned with each other. The rotation of the applying member or the frictional force applying member with respect to the mounting piece can be easily prevented.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of a chair to which the present invention is applied, FIG. 2 is a rear view of the chair, and the chair includes a leg (2) with casters (1) and a pedestal (3) standing up from the center. The support base (5), which is attached to the upper end of the support base (5), and the lower end of the support base (5) is pivotally attached to both sides of the support base (5). Is a back support frame (6) that is standing in the rear of the seat body (4) and has a substantially vertically downward U shape, and left and right 1 attached to the lower ends of both sides of the back support frame (6). It has a pair of armrests (7) and (7).

  A mesh-like backrest plate (9) on the rear surface of the backrest (8) is attached to the front surface of the backrest support frame (6).

  As shown in FIG. 3, the back support frame (6) is formed in a rearward convex arc shape by a pair of left and right side frames (10), (10) formed of aluminum alloy or the like, and also of aluminum alloy or the like. The upper frame (11) is made of.

  On the opposing surface at the upper end of both side frames (10), there are connecting pieces (10a) (10a) whose upper and lower dimensions are equal to those of the upper frame (11). It protrudes diagonally rearward and inward with a curvature almost equal to that of the two side ends.

  Bolt insertion grooves (12) that open to the front are formed on the front surfaces of both end portions of the upper frame (11), and the bolts (13) inserted into the bolt insertion grooves (12) are connected to the upper frame (11). The upper frame (11) is inserted into the upper ends of the left and right side frames (10) by inserting the side ends and screwing into the screw holes (not shown) to be provided on the inner surface of the coupling piece (10a). It looks nicely combined to give a sense of unity.

  (14) and (14) are a pair of left and right projections for attaching the upper end of the backrest plate (9) to the front of the backrest support frame (6), and the front of the upper end of both side frames (10). The upper and lower female screw holes (15) are formed in both protrusions (14) (see FIG. 4).

The headrest device (16) of the present invention is provided at the upper end of the back support frame (6).
The headrest device (16) includes a headrest frame (17) made of aluminum alloy or the like having a U-shape when viewed from the front, and a headrest (18) attached to the front surface thereof.

  As shown in FIG. 3, the headrest frame (17) has a pair of left and right downside ridges (17a) and (17a) whose left and right spacing dimensions are substantially equal to the spacing dimensions between the side frames (10) and (10). A horizontal bar (17b) that curves backward in a convex arc shape is integrally formed on the upper end of the upper and lower ends.

The front and rear and left and right dimensions of the lower end portion of the downward side flange (17a) are substantially equal to the front and rear and left and right dimensions of the upper end portion of the side frame (10) so that they have a sense of unity after mounting.
The headrest frame (17) is connected to the upper end of the backrest support frame (6) as follows.

  As shown in FIG. 4, at the upper ends of the left and right side frames (10) in the back support frame (6), there are bottomed recesses (19) that open upward in a short vertical dimension. Also, a female screw hole (20) having a small diameter and a long vertical dimension is formed so as to communicate with each other.

  At the lower end of the left and right downward flanges (17a) of the headrest frame (17), a stepped hole that opens downward, i.e., an upward concave hole (21) with a short vertical dimension, and a smaller diameter than that A connecting hole (22) having a long vertical dimension is formed in communication with each other.

(23) is a connecting member made of hard metal facing in the vertical direction, the screw shaft (24) at the lower end, the intermediate connecting shaft (25) having a diameter larger than that, and the intermediate connecting shaft (25). It has a small-diameter upper connecting shaft (26) and a short hexagonal shaft (27) connected to the upper end thereof.
The vertical dimension of the upper connecting shaft (26) and the hexagonal shaft (27) is slightly shorter than the connecting hole (22).

The screw shaft (24) is screwed into the female screw hole (20) of the side frame (10), and the lower half and the upper half of the intermediate connecting shaft (25) are recessed portions of the side frame (10), respectively. (19) is fitted into the recessed hole (21) of the downward side flange (17a), and the upper connection shaft (26) and the hexagonal shaft (27) are connected to the connection hole (22) of the downward side flange (17a). To be fitted.
An annular groove (28) is formed on the outer peripheral surface of the intermediate portion of the upper connecting shaft (26).

  In order to attach the headrest frame (17) to the backrest support frame (6), the screw shaft (24) at the lower end of the connecting member (23) is first inserted into the female screw holes (20) of the left and right side frames (10). Is screwed until the lower end of the intermediate connecting shaft (25) contacts the bottom surface of the recess (19), so that the connecting member (23) is connected to the upper half of the intermediate connecting shaft (25) at the side portion. Install so that it protrudes above the upper end of the frame (10).

  At this time, by rotating the hexagonal shaft (27) at the upper end of the connecting member (23) with a tool such as a spanner, the screw shaft (24) can be easily screwed into the female screw hole (20). Further, since the lower end of the intermediate connecting shaft (25) can be brought into strong contact with the bottom surface of the recess (19) by tightening firmly, the connecting member (23) can be firmly attached to the side frame (10).

  Next, the lower end of both the downward side ridges (17a) of the headrest frame (17) is opposed to the upper ends of the left and right side frames (10), and a concave hole provided at the lower end of the downward side ridge (17a) ( 21) and the connecting hole (22) are fitted into the protruding portion of the connecting member (23), that is, the upper half of the intermediate connecting shaft (25) and the upper connecting shaft (26), respectively.

  Next, it faces the front-rear direction communicating with the connection hole (22), which is formed in advance on the front surface of the lower end portion of the downward side flange (17a) so as to correspond to the annular groove (28) of the connection member (23). A slotted set screw (30) is inserted into the female screw hole (29) through a through hole (33) drilled in a guide rail (31) described later and screwed into the annular groove (28). Press.

  Thereby, the downward side ridge (17a) is secured to the connecting member (23), and the lower end of the headrest frame (17) is attached to the upper end of the backrest support frame (6).

  As shown in FIG. 3 and FIG. 4, the front surface of the left and right downward side ridges (17 a) in the headrest frame (17) is slightly shorter than the vertical dimension, and the left and right dimensions are substantially equal. A pair of synthetic resin guide rails (31) and (31) that support the headrest (18) and guide it up and down are attached by fixing the upper and lower ends with bolts (32).

A through hole (33) for inserting the set screw (30) is formed at the lower end of both guide rails (31).
On both side surfaces of both guide rails (31), a pair of left and right first guide grooves (34) and (34) having an inward concave shape whose lower end opens downward are formed to the vicinity of the upper end (see FIG. 5).

  Also, in the center of the front of both guide rails (31), there is a second concave guide groove (35) that opens to the front and faces backwards and concaves, and the upper and lower sides that face slightly to the left and right. The plurality of engaging grooves (36) are formed orthogonal to each other such that the second guide groove (35) is located at the center.

  On the left and right guide rails (31), a pair of elevating brackets (37) and (37) for supporting the headrest (18) and elevating are attached as follows.

  As shown in FIGS. 3 to 5, both the lifting brackets (37) are composed of, for example, a hard bracket body (38) formed of a fiber reinforced synthetic resin material and a softer synthetic resin material (for example, polyacetal resin). And an engaging member (39) formed by

  The bracket body (38) has a pair of left and right side pieces (38a) (38a) whose front-to-rear surface dimensions are approximately equal to the left-right dimensions of the guide rail (31), and a front piece having a square hole (40). 38b), a support cylinder (41) is formed integrally with the front upper end of both side pieces (38a) so as to face in the left-right direction.

  The center part of the opposing surface of both side pieces (38a) is a pair of first guide projecting pieces facing in the vertical direction that can be slidably fitted into the left and right first guide grooves (34) of the guide rail (31). (42) and (42) are integrally projected.

  As shown in an enlarged view in FIG. 6, the engaging member (39) can be fitted into the square hole (40) of the front piece (38b), and has a horizontal portion at the upper end and a base piece (39a facing upward). ) And an elastic piece (39b) standing up from the rear surface of the lower end thereof, and the upper end of the elastic piece (39b) is formed in a second guide groove (35) provided on the front surface of the guide rail (31). A second guide protrusion (43) facing vertically that can be slidably fitted in the vertical direction, and a plurality of upper and lower engagement grooves (36) provided on both sides of the guide rail (31). Engaging protrusions (44) and (44) that are selectively engageable and have a protruding dimension smaller than the second guide protrusion (43) and face in the left-right direction are integrally projected rearward. ing.

  At the upper and lower edges of the base piece (39a), it is rearward in the locking step (45) (45) formed at the upper and lower opening edges of the square hole (40) on the rear surface side of the front piece (38b). Retaining pieces (46) and (46) that prevent the forward removal from the square hole (40) by being further fitted are projected in the opposite directions.

  To attach the lifting bracket (37) to the guide rail (31), after fitting the engagement member (39) into the square hole (40) of the front piece (38b) in the bracket body (38), The first guide protrusions (42) and (42) on the inner surface of both side pieces (38a) are fitted into the first guide grooves (34) and (34) on both side surfaces of the guide rail (31) from the opening end at the lower end. Let At the same time, the upper end of the elastic piece (39b) of the engaging member (39) is pressed against the lower front surface of the guide rail (31) and bent forward, and the entire lifting bracket (37) is moved upward. The second guide protrusion (43) of the elastic piece (39b) is fitted into the second guide groove (35) on the front surface of the guide rail (31).

  Thus, the lifting bracket (37) is attached so as to be movable up and down so as to sandwich the guide rail (31) from the front, and the second guide protrusion (43) is the lower end of the second guide groove (35). Is prevented from falling off and the maximum downward movement amount is restricted. The maximum amount of upward movement of the lifting bracket (37) is regulated by the first guide protrusion (42) coming into contact with the upper end of the first guide groove (34).

  When the elevating bracket (37) is moved in the vertical direction, the elastic piece (39b) is elastically deformed in the front-rear direction, so that the engaging protrusions (44) provided on the elastic piece (39b) have a plurality of front surfaces of the guide rail (31). The vertical position (height) of the headrest (18) that is selectively engaged with any one of the engagement grooves (36) and attached to the lifting bracket (37) can be adjusted.

  As shown in FIGS. 3 and 4, a pair of mounting pieces (48) and (48) having mounting holes (47) facing in the left-right direction are provided at the lower ends of the left and right sides of the rear surface of the headrest (18). The cover (49) is inserted and protrudes backward.

  As shown in FIG. 8, the rear end of the mounting piece (48) is rotatably fitted on the front surface of the center portion of the support cylinder (41) in the left and right lifting brackets (37). A rearward concave mounting groove (50) is formed.

  As shown in FIG. 3 and FIG. 8, the mounting hole (47) of the mounting piece (48) loosely fitted in the mounting groove (50) has one side portion (right side in FIG. 8) communicating with the mounting groove (50). The cylindrical portion (52a) of the frictional force applying member (52) inserted from the stepped hole (51) in the half portion is fitted. At the right end of the cylindrical portion (52a) of the frictional force imparting member (52), the outer diameter of the inner end is larger than the outer diameter of the cylindrical portion (52a), and the outer diameter gradually decreases toward the outer end. Thus, the conical portion (52b) whose outer peripheral surface is tapered is integrally connected, and the whole is integrally formed of a hard synthetic resin (for example, polyacetal resin).

  As shown in FIG. 7, a protrusion (53) is connected to a part of the outer peripheral surface of the cylindrical portion (52a), and this protrusion (53) is attached to the mounting piece (48) as shown in FIG. ), The frictional force applying member (52) is fitted in such a manner that it cannot rotate relative to the mounting piece (48). Are combined.

  (55) is a substantially cylindrical frictional force imparting member, which is fitted into the inner small diameter part (51a) of the stepped hole (51) in the support cylinder (41) as shown in FIGS. A small-diameter cylindrical portion (55a), a short large-diameter flange portion (55b) that is fitted to the outer large-diameter portion (51b) of the stepped hole (51), and the large-diameter flange portion ( 55b) is provided with three projecting strips (55c) continuously provided at intervals of 120 ° in the circumferential direction on the outer peripheral surface of the intermediate portion of the small diameter cylindrical portion (55a).

  In addition, a tapered hole that complements the tapered outer peripheral surface of the small-diameter cylindrical portion (55a) is fitted with the conical portion (52b) of the frictional force applying member (52). (56) is formed.

  The three protruding strips (55c) are formed in three concave grooves (57) that are formed on the inner peripheral surface of the small-diameter portion (51a) of the stepped hole (51) and open outward and inward. It is fitted and cannot rotate relative to the support tube (41).

  The frictional force applying member (55) is integrally formed of a synthetic resin material that is softer and slightly elastic than the frictional force applying member (52), for example, a polyurethane-based elastomer.

  The mounting piece (48), the frictional force imparting member (52), and the frictional force imparting member (55) are stepped holes formed at the side end of the support tube (41) opposite to the stepped hole (51). The shaft hole (59a) of the stepped bolt (59) inserted from (58) is connected to the shaft hole (60) (60) having the same diameter as the frictional force applying member (52) and the frictional force applying member (55). ), And by screwing the barbed nut (61) into the male thread portion (59b) protruding into the stepped hole (51), it is attached to the support cylinder (41), that is, the lifting bracket (37), In addition, after the mounting, the side end of the cylindrical portion (52a) of the frictional force applying member (52) contacts the inner surface of the mounting groove (50), and the outer peripheral surface of the conical portion (52b) and the frictional force applying member. The inner surface of the tapered hole (56) of (55) is in contact with each other so as to be relatively rotatable.

  At this time, the tightening allowance and the tightening force of the frictional force applying member (55) by the brazing nut (61) are set so that the inner surface of the tapered hole (56) is slightly elastically deformed in the diameter increasing direction. It is preferable that the inner surface of 56) be in strong pressure contact with the outer peripheral surface of the conical portion (52b). By doing so, the frictional resistance between the contact surfaces becomes large, and the frictional force applying member (52) is applied to the frictional force applying member (55) in a state where a relatively large frictional force is applied. It will turn.

  Therefore, the rotational resistance of the mounting piece (48) and the headrest (18) which are substantially integrated with the frictional force applying member (52) is also increased, and the position of the headrest (18) in the front-rear direction relative to the backrest (8) is increased. The tilt angle can be adjusted steplessly, and it is prevented that the tilt angle is rotated even after the adjustment.

  Since the frictional force imparting member (55) is formed of a hard synthetic resin, even if it is relatively rotated with respect to the frictional force imparting member (55), the cone portion ( 52b) etc. will not be twisted.

  As described above, in the headrest device (16) of the above-described embodiment, the pair of right and left lifting brackets (37) that support the headrest (18) have a U-shape in a plan view, and the headrest frame ( 17) Hold both side surfaces of the guide rail (31) attached to the front of both downward facing rods (17a) from the front, and the inner side surface (opposite surface) of both side pieces (38a) of the left and right bracket bodies (38) The first guide protrusions (42) facing each other in the vertical direction are slidably fitted in the first guide grooves (34) on both sides of the left and right guide rails (31). Therefore, the headrest (18) can be moved up and down along the downwardly facing sides (17a) of the headrest frame (17) while stably supporting the headrest (18).

  In addition, a second guide groove (35) is provided in the center of the front surface of the left and right guide rails (31), and the second guide groove (35) is engaged between the both side pieces (38a) of the lifting bracket (37). The headrest (18) is more stable because the second guide projecting piece (43) facing the up and down direction protruding from the elastic piece (39b) of the joint member (39) is slidably fitted. Can move up and down.

  Furthermore, the headrest (18) is only supported via the lifting bracket (37) on the guide rail (31) provided on the front surface of the left and right side rods (17a) of the headrest frame (17), The degree of freedom in designing the entire headrest device (16) including the lifting bracket (37) and the headrest frame (17) is increased.

  Since the lower end of the first guide groove (34) opens downward, the first guide protrusion (42) can be easily fitted from the lower end, and the guide rail (37) of the lifting bracket (37) Installation to 31) becomes extremely easy.

  Further, since the second guide protrusion (43) protrudes from the rear surface of the upper end of the elastic piece (39b) which can be elastically deformed in the front-rear direction, it can be easily fitted into the second guide groove (35). After the fitting, the second guide protrusion (43) comes into contact with the lower end of the second guide groove (35), so that the lifting bracket (37) and the headrest supported by the lifting bracket (37) can be obtained by simple means. The dropout from the guide rail (31) of (18) is prevented.

  On the front surface of the guide rail (31), a second guide groove (35) and a plurality of upper and lower engaging grooves (36) facing in the left-right direction are perpendicular to each other with the second guide groove (35) positioned at the center. The second guide groove (35) is fitted with the second guide protrusion (43) at the center of the elastic piece (39b), and the engaging protrusions (44) on both sides sandwiching the second guide groove (35). Is engaged with the engagement groove (36), the engagement protrusion (44) is reliably and stably engaged with the engagement groove (36).

  Further, when the engagement protrusion (44) is detached from the engagement groove (36), the elastic piece (39b) bends forward, so that when the headrest (18) is raised and lowered, the headrest frame (17) No bending load or the like is applied to the left and right downward side rods (17a), and the vertical position of the headrest (18) can be easily adjusted with a light force.

  The elevating bracket (37) is a member that engages with the rear bracket-shaped rigid bracket body (38) that clamps the guide rail (31) from the front, and the engagement groove (36) of the guide rail (31). The engagement member (39) is composed of two members including an engagement member (39) having a mating protrusion (44), and the engagement member (39) is formed in a square hole (40) provided in the front piece (38b) of the bracket body (38). Since the engagement protrusion (44) is worn and held, it can be inserted and removed from the rear so that the lifting bracket (37) can be moved together with the headrest (18) from the lower end of the guide rail (31). It can be removed and only the engagement member (39) can be easily replaced.

  The engaging member (39) is held by the square hole (40) of the hard bracket body (38), and can be moved up and down stably integrally with the bracket body (38).

  In the above embodiment, the guide rail (31) is provided separately from the headrest frame (17) so that it can be replaced when it is worn, etc. And the front side thereof may be the same guide rail (31) as described above.

  Moreover, in the said embodiment, although the 1st guide groove (34) is provided in the both sides | surfaces of the left and right guide rail (31), while providing these guide grooves (34) only in an outer surface or an inner surface, Correspondingly, the first guide protrusion (42) of the lifting bracket (37) may be only one. Further, the backrest support frame (6) may be extended above the backrest (8) without using the headrest frame (17) as a separate body, and its upper end may be used as a headrest frame.

  In the above-described embodiment, the headrest (18) is attached to the pair of lifting brackets (37) by the guide rails (31) provided on the left and right side rods (17a) of the headrest frame (17) having a downward U shape when viewed from the front. For example, a slightly wider headrest frame is erected from the center upper end of the back support frame (6), and a guide rail having the same structure as the above is provided on the front surface. The headrest (18) may be supported by one lifting bracket similar to the above attached to the rail.

  In the above embodiment, the conical portion (52b) is provided on the frictional force applying member (52) side, and this conical portion (52b) is fitted into the tapered hole (56) of the frictional force applying member (55). The inner surface is pressed against the inner surface, but conversely, a conical portion may be provided on the frictional force applying member (55) side, and a tapered hole may be provided on the frictional force applying member (52) so as to face each other.

  Contrary to the above embodiment, the frictional force imparting member (52) is provided on the support cylinder (41) of the lifting bracket (37) so as not to be relatively rotatable, and the frictional force imparting member (55) is provided with the headrest. The mounting piece (48) of (18) may be provided in a relatively non-rotatable manner.

  In the above embodiment, the entire frictional force applying member (55) is formed of an elastomer or the like, but the contact surface with the conical portion (52b) is fixed by fixing the elastomer or the like to the inner surface of the tapered hole (56). Only a soft material may be used. In this way, twisting of the frictional force applying member (55) can also be prevented.

  In the above embodiment, in order to increase the frictional resistance between the contact surfaces, the frictional force imparting member (55) is formed of a softer elastomer or the like than the frictional force imparting member (52). The material of the member (55) is the same material as the frictional force imparting member (52), and the required friction is applied to the contact surface by adjusting the tightening force of the step bolt (59) and nut (61). Sometimes resistance is obtained.

  The means for preventing the lifting bracket (37) from falling off from the guide rail (31) may be a pin or the like penetrating the lower end of the first guide groove (34) and facing in the left-right direction.

  Of course, the present invention can be applied to a headrest device of an automobile or other vehicles in addition to the chair.

It is a side view of the chair to which this invention is applied. Similarly, it is a rear view. It is a disassembled perspective view of a headrest device. Similarly, it is a partially cutaway enlarged side view. FIG. 5 is an enlarged cross-sectional plan view taken along line VV in FIG. 4. It is an expansion perspective view of an engaging member. It is an expansion front perspective view of a frictional force provision member and a to-be-frictioned force provision member. It is the VIII-VIII line enlarged vertical end view of FIG. It is the IX-IX line vertical side view of FIG.

Explanation of symbols

(1) Casters
(2) Leg
(3) pedestal
(4) Seat
(5) Support base
(6) Back support frame
(7) Armrest
(8) Backrest
(9) Backrest board
(10) Side frame
(11) Upper frame
(12) Bolt insertion groove
(13) Bolt
(14) Mounting member
(15) Bolt
(16) Headrest device
(17) Headrest frame
(17a) Downward side fence
(17b) Yokohama
(18) Headrest
(19) Recess
(20) Female thread hole
(21) Recessed hole
(22) Connecting hole
(23) Connecting member
(24) Screw shaft
(25) Intermediate connecting shaft
(26) Upper connecting shaft
(27) Hexagon shaft
(28) Annular groove
(29) Female thread hole
(30) Set screw
(31) Guide rail
(32) Bolt
(33) Through hole
(34) 1st guide groove
(35) Second guide groove
(36) Engagement groove
(37) Lift bracket
(38) Bracket body
(38a) side piece
(38b) Front piece
(39) Engagement member
(39a) Base piece
(39b) Elastic piece
(40) Square hole
(41) Support cylinder
(42) 1st guide protrusion
(43) Second guide protrusion
(44) Engagement protrusion
(45) Locking step
(46) retaining piece
(47) Mounting hole
(48) Mounting piece
(49) Back cover
(50) Mounting groove
(51) Stepped hole
(51a) Small diameter part
(51b) Large diameter part
(52) Friction force imparting member
(52a) Cylindrical part
(52b) Conical part
(53) Protrusion
(54) Groove
(55) Friction force imparting member
(55a) Small diameter cylinder
(55b) Large diameter collar
(55c) Projection strip
(56) Taper hole
(57) Groove
(58) Stepped hole
(59) Stepped bolt
(59a) Shaft
(59b) Male thread
(60) Shaft hole
(61) Bracket nut

Claims (9)

  In a headrest device in which a headrest is attached to a frame extending upward from the backrest so as to be pivotable back and forth with a pivot that faces in the left-right direction, a shaft facing in the left-right direction on either the frame or the headrest A frictional force imparting member having a hole is provided so as not to be relatively rotatable. Similarly, a frictional force imparting member having a shaft hole facing in the left-right direction is not rotatable relative to the frictional force imparting member and is opposed to the left and right. The taper hole provided in either one of the opposing parts of the frictional force applying member and the frictional force applying member is fitted with the tapered part provided in the other of the opposing parts and the conical part that forms a complementary shape. The pivot shaft is inserted into the shaft holes of the frictional force applying member and the frictional force applying member, and the frictional force applying member and the frictional force applying member are connected to the contact surface between the tapered hole and the conical portion. As can be relatively friction rotating, the headrest apparatus characterized by bound by clamping means.   The headrest device according to claim 1, wherein the frictional force applying member is formed of a hard material, and the frictional force applying member is formed of a softer material than the frictional force applying member.   The frictional force imparting member is formed of a hard material, and only the contact surface of the frictional force imparting member with the frictional force imparting member is formed of a material softer than the frictional force imparting member. The headrest device described.   4. The headrest device according to claim 2, wherein the frictional force applying member or a contact surface with the frictional force applying member is made of an elastomer, and the frictional force applying member is made of a hard synthetic resin.   The tightening means has a pivot shaft facing in the left-right direction, a stepped bolt having a diameter-expanded head on one end side, and a male screw portion having a smaller diameter than the pivot shaft on the other end side, 5. A hooked nut capable of pressing either one of the side end surfaces of a frictional force applying member and a frictional force applying member that are screwed into a male screw portion and fitted to the pivot. The headrest apparatus in any one of.   Provided on the front surface of the frame is a support cylinder that faces in the left-right direction and is open at both ends. A friction force applying member, a frictional force applying member, and a tightening means are provided in the hollow hole of the support cylinder to apply a friction force. The headrest device according to claim 1, wherein the headrest device is configured to prevent rotation of one of the member and the frictional force imparting member and allow the other rotation.   The headrest device according to claim 6, wherein the inner surface of the hollow hole of the support cylinder and the outer peripheral surface of the frictional force imparting member or the frictional force imparting member are provided with axially protruding ridges and concave grooves that fit together.   A mounting piece extending toward the support tube is projected on the rear surface of the headrest, and the rear end portion of the mounting piece is loosely fitted in a mounting hole provided on the outer peripheral surface of the support tube and communicating with the hollow hole, The headrest device according to claim 6 or 7, wherein a mounting hole provided in a rear end portion of the mounting piece is externally fitted to a frictional force applying member or a frictional force applying member accommodated in the support cylinder so as not to be relatively rotatable.   The headrest device according to claim 8, wherein a projecting portion and a recessed groove facing each other in an axial direction are provided on the inner surface of the mounting hole and the outer peripheral surface of the frictional force imparting member or the frictional force imparting member.

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