JP4441329B2 - Armrest height adjustment device - Google Patents

Description

  The present invention relates to an armrest height adjusting device.

Conventionally, it is known that the height of an armrest provided on a side portion of a dorsal seat is adjusted using friction of a coil spring. (Patent Document 1).
A lock spring comprising a coil portion that fits on the outer periphery of the shaft, a moving end portion that always rotates integrally with the armrest, and a free end that is connected to and disengaged from the fitting groove for movement of the armrest; and provided on the shaft side There has been proposed a structure provided with an unlocking actuating member for engaging the free end with the moving fitting groove and an unlocking portion for releasing the free end engaged with the moving fitting groove (Patent Document 2). .
Japanese Utility Model Publication No. 5-53547 JP 2003-299547 A

In the known example, the downward movement of the armrest is locked by a frictional force, but there is a problem that the tip of the armrest swings up and down after the tilt adjustment.
One of the causes was found to be a problem with the method of fixing the end of the lock spring.
In other words, the lock spring is fixed at its fixed end, so that the coil portion can be tightened and locked even if the other end is a free end, but the armrest base can be slightly rotated after tilt adjustment. Thus, when the fixed portion of the fixed side end portion is deformed, this deformation is propagated to the coil portion, and as a result, the coil portion is loosened. Then, the amount of deformation of the fixed portion of the fixed side end portion affects the vertical amplitude of the tip of the armrest after the tilt adjustment.
In the present application, the fixing means at the fixed side end is specially devised, and the tip of the armrest reduces the vertical amount after adjusting the inclination, thereby improving the commercial value.

In the present invention, the coil portion 12 of the lock spring 11 is fitted to the outer periphery of the lateral collar 10 on the side portion of the back sheet 3 of the seat 1, and the height can be adjusted by friction between the coil portion 12 and the collar 10. An armrest having a locking device L is provided, and the locking device L has a switching cam groove of a spring mounting bracket 13 in which the free end 20 of the coil portion 12 is provided on the back bracket 6 or the armrest bracket 9 by the contact member 30. The fixed side end 15 of the coil portion 12 is changed by the stay 14 fixed to the spring mounting bracket 13 so that the diameter of the coil portion 12 is changed. The stay 14 is substantially parallel to the side plate 50 of the spring mounting bracket 13 and is fixed so as to prevent deformation of the fixed side end 15. A pair of plate portions 51 fixed to the plate 50 is provided, and a fitting groove 53 is formed between the pair of plate portions 51 for fitting and inserting the fixed side end portion 15. The fitting groove 53 is formed between the convex portions 54 provided between the pair of plate portions 51, the end portions of the convex portions 54 are brought into contact with the coil portion 12, A pair of plate portions 51 of the stay 14 are formed with tongue-shaped guide portions 58 extending vertically, and the collar portions 10 side of the plate portions 51 and the guide portions 58 are arcuate surfaces that match the outer shape of the coil portion 12. formed in 52, upper and lower edge of the counter-collar 10 side of the guide portion 58 is formed on the outer arcuate surface 59 of arcuate shape centered on the axis of the respective collar 10, the guide pin 60 and the outer arcuate surface 59 abutting Is an armrest height adjusting device provided on the side plate 50 of the spring mounting bracket 13. It is.
In the present invention, the fitting groove 53 of the stay 14 is formed by providing a convex portion 54 between a pair of plate portions 51, and an upright surface 56 on the insertion side of the fixed side end portion 15 of the convex portion 54. Is formed by cutting out in accordance with the shape of the bent portion 57 at the boundary between the fixed-side end portion 15 and the coil portion 12, and the height adjustment device of the armrest is configured such that the bent portion 57 is in close contact with the standing surface 56. It is what.
In the present invention, the height of the armrest is adjusted so that the inner width of the fitting groove 53 matches the width of the fixed side end 15.

In the invention of claim 1, the product value can be improved by reducing the vertical amount of the tip of the armrest 4 after adjusting the inclination.
According to the second aspect of the present invention, the fixed-side end portion 15 is closely fitted in the fitting groove 53 of the stay 14 and is not deformed, and the coil portion 12 can be prevented from loosening .
According to the third aspect of the invention, the deformation of the fixed side end 15 can be prevented with a simple configuration, and the cost can be reduced.
In the invention of claim 4 , since the bent portion 57 at the boundary between the fixed side end 15 and the coil portion 12 is brought into close contact with the upright surface 56, the deformation amount of the fixed side end 15 and the coil portion 12 can be further reduced.
In the fifth aspect of the invention, the fixed side end 15 can be set so that the free end 20 is positioned at a predetermined position, and mounting (assembly) is facilitated, and mounting accuracy is improved.

An embodiment of the present invention will be described with reference to the drawings. 1 is a vehicle seat, 2 is a seat seat, 3 is a back seat provided on the seat seat 2 so that the inclination angle can be adjusted, and 4 is a side portion of the back seat 3. It is the armrest provided in.
The armrest 4 is attached to a dorsal bracket 6 provided on the side of the dorsal skeleton frame 5 of the dorsal seat 3 so as to be pivotable up and down around a shaft 7 in the left-right direction. The attachment configuration 5 is optional.
Although the configuration of the armrest 4 is also arbitrary, in the embodiment, in the originally used use range A, the lower rotation of the armrest 4 is locked to support the load, and only the upward rotation is freely adjustable. The storage range B that is the same as the upper limit position of the usage range A or spaced apart from the upper limit position is unlocked and can be turned up and down, and temporarily lower from the storage range B to the lowest position of the usage range A Although it can be rotated, it is configured to return to the lockable state at the lowest position so that only upward rotation is possible in the use range A (FIG. 1).

Therefore, the armrest 4 is provided with a lock device L between the base portion of the armrest frame 8 and the dorsal bracket 6. The locking device L can be adjusted by adjusting the inclination by fitting the coil portion 12 of the lock spring 11 to the outer periphery of the collar 10 provided on the outer periphery of the shaft 7, locking it by the friction of the lock spring 11, and unlocking it by releasing the friction. Other configurations are arbitrary as long as they are configured.
That is, the spring mounting bracket 13 is fixed to either the back bracket 6 or the armrest bracket 9 of the armrest 4, the stay 14 is fixed to the spring mounting bracket 13, and one end of the lock spring 11 is engaged with the stay 14. And the other end of the lock spring 11 is formed at the free end 20, and the coil portion 12 is set in a winding direction to be tightened when the collar 10 rotates with the downward movement of the armrest 4. Thus, if the arm rest 4 is rotated downward even if the other end is the free end 20, the diameter of the coil portion 12 is reduced by the frictional resistance between the collar 10 and the inner periphery of the coil portion 12. The frictional resistance acts to prevent the armrest 4 from rotating downward and lock it.
Therefore, the fixed side end 15 is expressed as “fixed side”, but this is an expression for distinguishing the free end 20 for easy understanding, and does not mean position immobility, As will be described later, when the spring mounting bracket 13 and the stay 14 are mounted on the moving side (armrest 4), the fixed side end 15 moves to the center of the shaft 7.

By the way, when the coil portion 12 exhibits normal frictional resistance, the tip of the armrest 4 does not move downward, but when the fixed side end portion 15 engaged with the stay 14 moves, the coil portion 12 loosens, After the coil portion 12 is locked by adjusting the inclination, the tip of the armrest 4 may be lowered.
The stay 14 is configured to suppress the deformation of the fixed-side end 15 as much as possible when the diameter of the coil portion 12 of the lock spring 11 is changed. To prevent.
The stay 14 fixes a pair of plate portions 51 parallel to the side plate 50 of the spring mounting bracket 13 to the side plate 50 (FIGS. 3 and 19). The collar portion 10 side of the plate portion 51 is formed on an arc surface 52 that matches the outer shape of the coil portion 12. A convex portion 54 for forming a fitting groove 53 into which the fixed side end portion 15 is fitted and inserted is formed between the pair of plate portions 51. The convex portion 54 is formed as narrow as possible within a range in which the inner width of the inner fitting groove 53 is substantially coincident with the width of the fixed-side end portion 15 and can be fitted.

In the embodiment, the fixed-side end 15 and the fitting groove 53 are formed in a square shape (FIGS. 3 and 19), and are further brought into close contact with each other to prevent the fixed-side end 15 from being deformed.
The raised surface 56 on the collar 10 side of the convex portion 54 is formed by cutting out in accordance with the shape of the bent portion 57 at the boundary between the fixed-side end portion 15 and the coil portion 12 when viewed from the side, and the bent portion 57 is the raised surface 56 ( If it is configured so as to be in close contact with FIG. 19) (FIG. 23), it is possible to prevent further deformation of the fixed-side end 15.

Accordingly, tongue-shaped guide portions 58 extending vertically are formed at the tips of the pair of plate portions 51 (FIG. 19). The guide portion 58 is formed on the collar 10 side as an arc surface 52 by extending the arc surface 52 as it is, and the upper and lower edges on the opposite side are formed on the outer arc surface 59 that is concentric with the axis of the collar 10. To do. A guide pin 60 provided on the side plate 50 of the spring mounting bracket 13 is brought into contact with the outer circular arc surface 59.
In the stay 14, the arc surface 52 is guided by the outer periphery of the coil portion 12 on the inside, and the outside arc surface 59 of the guide portion 58 is guided by the guide pin 60 on the outside and moves (FIG. 19). Therefore, the fixed side end portion 15 always moves in a circle toward the center of the collar 10, so that the deformation of the fixed side end portion 15 with respect to the coil portion 12 is prevented.

  That is, the position of the stay 14 (fixed side end 15) is shifted due to manufacturing tolerances. However, the stay 14 is moved in a circle around the axis of the collar 10 by the guide portion 58 and the guide pin 60, and the coil portion. In this state, the stay 14 is welded and fixed to the side plate 50 of the spring mounting bracket 13 so that the coil portion 12 can be accurately mounted. On the other hand, deformation of the fixed side end 15 is prevented.

Thus, the configuration to hold the free end 20 of the locking device L in the unlocked position and the lockable state are arbitrary, but an example will be shown below.
The spring mounting bracket 13 is fixed to the dorsal bracket 6, and the spring mounting bracket 13 has an unlocking cam surface 22 that holds the free end 20 of the locking device L in the unlocked position, and the unlocking cam surface. A switching cam groove 24 having a guide cam surface 23 that guides the engagement with the cam 22 is formed.
The switching cam groove 24 is formed in a bent plate portion 25 bent substantially parallel to the axis of the collar 10, and the bent plate portion 25 is formed in the spring mounting bracket 13. The switching cam groove 24 is basically formed in a U shape in which the distal end side (left side) of the bent plate portion 25 is opened parallel to the axial direction (left and right direction) of the collar 10.
In the embodiment, the bent plate portion 25 is formed on the lower side of the spring mounting bracket 13, and FIGS. 5, 7, 9, 11, 13, 15, 15, 17, and 18 are viewed from the lower side. However, the installation position of the bent plate portion 25 is not limited to the illustration.

The unlocking cam surface 22 is formed substantially parallel to the axial direction of the collar 10 on the lower rotation direction side (rear side) of the armrest 4 of the switching cam groove 24, and the upper camrest 22 of the switching cam groove 24 rotates upward. On the moving direction side (front side), a guide cam surface 23 is formed by being inclined so as to approach the unlocking cam surface 22 (rear side) in the opening direction (left direction) of the switching cam groove 24.
A gap 26 through which the free end 20 can pass is provided between the tip of the guide cam surface 23 and the outer edge of the unlock cam surface 22.
The bent plate portion 25 following the unlock cam surface 22 is formed on an inclined surface 27 that approaches the base side (right side) of the bent plate portion 25 as it reaches the rear side.
On the other hand, the shaft 7 and the collar 10 are provided with a contact member 30 that rotates and moves by the rotation of the armrest 4 and contacts the free end 20. The abutting member 30 fixes a plate member 31 in a direction intersecting the collar 10 to an end portion of the collar 10, and the plate member 31 is an abutment for unlocking in which the free end 20 is fitted in the switching cam groove 24. A portion 32 is provided. The unlocking contact portion 32 contacts the free end 20 in the locked state, moves the free end 20 in the loosening direction of the coil portion 12, and the free end 20 pushed by the unlocking contact portion 32 is the guide cam surface. 23, and is fitted into the switching cam groove 24.

When the end of the unlocking contact portion 32 coincides with the edge of the unlocking cam surface 22 and the free end 20 is guided and moved by the guide cam surface 23 to the end of the unlocking contact portion 32, The free end 20 comes off the unlock contact portion 32 and abuts on the unlock cam surface 22 by the elasticity of the free end 20 itself.
Further, if the unlocking contact portion 32 is arranged so that the armrest 4 is positioned between the upper limit position of the use range A and the storage range B, the unlocking portion 32 can be unlocked without moving the armrest 4 up to the upper limit of the storage range B. The armrest 4 can be turned downward in the locked state, and the operability is remarkably improved.
Further, a disengagement preventing surface 34 in the crossing direction is provided on the rear peripheral edge of the plate member 31 following the unlock holding surface 33. The disengagement prevention surface 34 prevents the free end 20 from being disengaged from both the switching cam groove 24 and the peripheral edge of the plate member 31 and becoming inoperable.

In other words, if the disengagement prevention surface 34 is not provided, the free end 20 engages with the switching cam groove 24 and is in contact with the unlock holding surface 33 so that it can be rotated excessively from the retracted position. However, the armrest 4 is prevented from excessively rotating by the disengagement preventing surface 34 to prevent the mechanical lock.
In this case, the armrest 4 is set so that the free end 20 is fitted in the switching cam groove 24 when the armrest 4 is rotated upward to the upper limit position of the use range A that is originally used as the armrest 4. In the storage range B beyond, the free end 20 is always fitted in the switching cam groove 24 and held by the unlock holding surface 33.

Accordingly, the free end 20 engaged with the unlocking cam surface 22 of the switching cam groove 24 is detached from the unlocking cam surface 22 at the front portion of the plate member 31 to make the free end 20 free. An unlock release unit 37 for returning is provided. The unlocking portion 37 bends the front end portion of the plate member 31 toward the spring mounting bracket 13 to form a bent portion 38, and inclines forward (upward rotational direction side) from the tip of the bent portion 38 to the base portion. The tilt release surface 39 is formed, and the tilt release surface 39 is positioned outside the edge of the unlock cam surface 22 so that the unlock cam surface 22 and the contact member 30 move relative to each other. The free end 20 is guided by the inclination release surface 39 of the unlock release portion 37 and is separated from the unlock cam surface 22 (switching cam groove 24), thereby bringing the unlocked state into a lockable state.
In the embodiment, the spring mounting bracket 13 is fixed to the dorsal bracket 6. However, as described above, the spring mounting bracket 13 may be fixed to the armrest bracket 9. The position is fixed.
That is, one of the spring mounting bracket 13 and the contact member 30 is relatively rotated about the shaft 7 with respect to the other, and the fixed side end 15 and the free end 20 are relatively rotated to reduce the diameter. What is necessary is just to fix the position of either the spring mounting bracket 13 or the contact member 30. Further, the locking device L is established regardless of whether the collar 10 rotates with the lock spring 11 or not.

Next, the operation of the embodiment will be described.
The armrest 4 is in a use state within a use range A including a substantially horizontal position. In the use range A, once the armrest 4 is rotated downward to the lowest position, the lock device L is in an activated state and can be rotated upward. The downward rotation is locked to support the load.
Therefore, the armrest 4 is once rotated downward to the lowest position in the use range A, and then the armrest 4 is rotated upward as necessary to adjust the height of the armrest 4.
Next, when the armrest 4 is rotated upward to the uppermost position of the use range A, this position is the upper limit position that locks the downward rotation of the armrest 4 and supports the load. The range is B, and the storage range B is unlocked in any direction.

Thus, in order to change the storage position to the use state, the armrest 4 is once rotated downward to the lowest position of the use range A as described above, and the lock device L is activated. The operation (operation) is repeated.
The operation of the locking device L will be described in detail. The base portion of the collar 10 in the left-right direction is fixed to the bracket 6 of the dorsal skeleton frame 5, and the coil portion 12 of the lock spring 11 is fitted to the outer periphery of the collar 10. One end of the lock spring 11 is engaged with a stay 14 provided on the spring mounting bracket 13, the other end of the lock spring 11 is formed at the free end 20, and the coil portion 12 is rotated with the upward movement of the armrest 4. Since the winding direction is set so as to be loosened when the collar 10 is rotated, when the armrest 4 is rotated downward in the use range A, the frictional resistance between the inner periphery of the coil portion 12 and the outer periphery of the collar 10 is caused by the rotation of the collar 10. This resistance acts to reduce the diameter of the coil portion 12, and this resistance prevents the armrest 4 from rotating downward and locks it.

Therefore, the height adjustment for rotating the armrest 4 upward is free, and the load applied to the armrest 4 is locked by restricting the downward rotation.
Thus, when the armrest 4 is rotated upward to the uppermost position in the use range A, the unlocking contact portion 32 on the rear side of the plate member 31 of the contact member 30 that rotates together with the armrest 4 contacts the free end 20. The unlocking contact portion 32 moves the free end 20 forward (in the loosening direction).
Therefore, the free end 20 is pressed by the unlocking contact portion 32 to contact the guide cam surface 23 of the spring mounting bracket 13, and the free end 20 pressed by the unlocking contact portion 32 is further guided to the guide cam surface. When the free end 20 moves to the edge of the unlocking contact portion 32, the free end 20 is disengaged from the unlocking contact portion 32, and the free end 20 itself is moved. When the free end 20 is engaged with the switching cam groove 24 by moving toward the unlocking cam surface 22 by elasticity, both the fixed side end 15 and the free end 20 of the lock spring 11 are in an immobile state. Thus, the diameter of the coil portion 12 does not change, the locking device L is unlocked, and the armrest 4 can be rotated in any direction up and down (of course, upward rotation is also free).
Accordingly, the position where the free end 20 is fitted in the switching cam groove 24 is set to the upper limit position of the use range A where the armrest 4 is originally used as the armrest 4, and therefore the storage range B beyond the use range A. As a result, the free end 20 is always engaged with the switching cam groove 24 and unlocked.

  Thus, the collar 10 is fixed to the armrest frame 8, the contact member 30 is fixed to the collar 10, and the contact member 30 is free by releasing the free end 20 fitted in the switching cam groove 24. Since the unlocking portion 37 for returning to the state is provided, when the locking device L is once unlocked and the armrest 4 is rotated downward to the lowest position in the use range A, the unlocking portion 37 The tilt release surface 39 hits the free end 20, and the tilt release surface 39 causes the free end 20 to move in the axial direction of the collar 10 while hitting the unlock cam surface 22. The elastic force of the end 20 leaves the switching cam groove 24 through the gap 26, and the lock device L is activated to lock the downward rotation of the armrest 4.

In this case, the unlocking cam surface 22 is formed at the rear portion in the switching cam groove 24 in a surface shape intersecting the axial direction of the collar 10, and the free end 20 is an unlocking cam so that the coil portion 12 is loosened. Since it is pushed by the surface 22, when it passes the edge of the unlocking cam surface 22, it is released from the switching cam groove 24 through the gap 26 due to the elasticity of the free end 20, whereby the diameter of the coil portion 12 is increased. The original small diameter state is restored, the lock device L is activated, and the downward rotation of the armrest 4 is locked.
As described above, the configuration in which the free end 20 is connected to and detached from the switching cam groove 24 is only required to provide the shape of the switching cam groove 24 and the contact member 30 that contacts the free end 20, so that the operation is reliable and inexpensive. Can be.
In addition, the setting of the use range A and the storage range B can be changed simply by replacing the contact member 30 with the position (distance) between the unlock contact portion 32 and the inclination release surface 39 changed.

Thus, when the coil portion 12 of the lock spring 11 exhibits a normal frictional resistance against the collar 10, the tip of the armrest 4 does not move downward, but the portion of the fixed side end 15 engaged with the stay 14 is slightly. However, if the coil portion 12 is loosened by movement, the tip of the armrest 4 may be lowered, and in particular, after the inclination angle adjustment that is stopped by moving the armrest 4 upward in the unlocked state, the portion of the fixed side end portion 15 The tip of the armrest 4 may be lowered due to deformation.
In the present application, the stay 14 that locks the fixed-side end portion 15 is configured to suppress deformation of the fixed-side end portion 15 as much as possible even when the diameter of the coil portion 12 changes. The downward movement of the tip of the armrest 4 after tilt adjustment is prevented.

That is, the stay 14 is provided with a pair of plate portions 51 parallel to the side plate 50 of the spring mounting bracket 13, and a fitting groove 53 for fitting and inserting the fixed side end portion 15 is formed between the pair of plate portions 51. And the inner width of the fitting groove 53 is substantially the same as the width of the fixed-side end 15, so that the fixed-side end 15 is deformed in the fitting groove 53 of the stay 14. The coil portion 12 is prevented from loosening.
Further, the standing surface 56 at the entrance (collar 10 side) of the convex portion 54 (fitting groove 53) is cut out in accordance with the shape of the bent portion 57 at the boundary between the fixed side end portion 15 and the coil portion 12 in side view. Since the bent portion 57 is formed so as to be in close contact with the upright surface 56, deformation of the base portion of the fixed side end portion 15 can be prevented.

  Thus, tongue-shaped guide portions 58 extending vertically are formed at the tips of the pair of plate portions 51, and the collar portion 10 side of the plate portion 51 and the guide portion 58 is an arcuate surface 52 that matches the outer shape of the coil portion 12. In addition, the upper and lower edges of the guide portion 58 on the side opposite to the collar 10 are formed on the outer arc surface 59 that is concentric with the axis of the collar 10, so that the spring is attached to the outer arc surface 59. The stay 14 is moved and fixed so that the fixed side end 15 is positioned at a predetermined position while the guide pin 60 provided on the bracket 13 is in contact.

That is, the position of the stay 14 (fixed side end 15) differs depending on each locking device L due to manufacturing tolerances. When the stay 14 is fixed while being shifted, the coil portion 12 is loosened and the fixed side end 15 is deformed. Although the stay 14 is moved while the guide pin 60 provided on the side plate 50 of the spring mounting bracket 13 is in contact with the outer circular arc surface 59, the stay 14 moves the axis of the collar 10. The fixed side end 15 always faces the radial direction from the center of the collar 10 regardless of the position where the circle moves around the center and is fixed. At this point, the deformation of the fixed side end 15 with respect to the coil part 12 To prevent.
In addition, although the above-mentioned embodiment is described individually and concretely for easy understanding, it is limited in selecting the requirements of the configuration, operation, etc. because it is not explicit from any description. Not.

The side view of a sheet | seat. The disassembled perspective view of the locking device of one Example. The same part expansion exploded perspective view. The side view which shows the positional relationship of an armrest and a supine frame frame. The perspective view of the locking device of FIG. The side view which shows the positional relationship of an armrest and a supine frame frame. The perspective view of the locking device of FIG. The side view which shows the positional relationship of an armrest and a supine frame frame. The perspective view of the locking device of FIG. The side view which shows the positional relationship of an armrest and a supine frame frame. The perspective view of the locking device of FIG. The side view which shows the positional relationship of an armrest and a supine frame frame. The perspective view of the locking device of FIG. The side view which shows the positional relationship of an armrest and a supine frame frame. The perspective view of the locking device of FIG. The side view which shows the positional relationship of an armrest and a supine frame frame. The perspective view of the locking device of FIG. The positional relationship figure of a switching cam groove and a contact member. The side view of the position adjustment state of a stay. The perspective view of a dorsal bracket. The side view of a locking device. FIG. The top view of the locking device which fractured | ruptured a part of stay.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Seat, 2 ... Seat seat, 3 ... Dorsal seat, 4 ... Armrest, 5 ... Dorsal skeleton frame, 6 ... Dorsal bracket, 7 ... Shaft, 8 ... Armrest frame, 9 ... Armrest bracket, 10 ... Color, DESCRIPTION OF SYMBOLS 11 ... Lock spring, 12 ... Coil part, 13 ... Spring mounting bracket, 14 ... Stay, 15 ... Fixed side end, 20 ... Free end, 22 ... Unlocking cam surface, 23 ... Guide cam surface, 24 ... Switching Cam groove, 25 ... bent plate portion, 26 ... gap, 27 ... inclined surface, 30 ... abutting member, 31 ... plate member, 32 ... unlocking abutting portion, 33 ... unlock holding surface, 34 ... disengagement preventing surface 37 ... Unlocking part, 38 ... Bending part, 39 ... Inclination releasing surface, 50 ... Side plate, 51 ... Plate part, 52 ... Arc surface, 53 ... Fitting groove, 54 ... Convex part, 56 ... Standing surface, 57 ... Bent part, 58 ... Guide part, 5 ... outer arc surface, 60 ... guide pin.

Claims (3)

A locking device in which the coil portion 12 of the lock spring 11 is fitted to the outer periphery of the lateral collar 10 on the side portion of the back sheet 3 of the seat 1 so that the height can be adjusted by friction between the coil portion 12 and the collar 10. An armrest having L is provided, and the locking device L is adapted to connect / disconnect the free end 20 of the coil portion 12 to the switching cam groove 24 of the spring mounting bracket 13 provided on the dorsal bracket 6 or the armrest bracket 9 by the contact member 30. The fixed side end 15 of the coil portion 12 can also be switched between an unlocked state and a locked state, even when the diameter of the coil portion 12 changes due to a stay 14 fixed to the spring mounting bracket 13. The stay 14 is fixed to the side plate 50 so as to be substantially parallel to the side plate 50 of the spring mounting bracket 13. A fitting groove 53 is formed between the pair of plate portions 51, and the fixed-side end portion 15 is fitted and inserted between the pair of plate portions 51, and the fixed-side end portion 15 is inserted into the fitting groove 53. The fitting groove 53 is formed between the convex portions 54 provided between the pair of plate portions 51, the end portions of the convex portions 54 are brought into contact with the coil portion 12, and the stay 14 The pair of plate portions 51 are formed with tongue-shaped guide portions 58 extending vertically, and the collar portion 10 side of the plate portion 51 and the guide portion 58 is formed on an arcuate surface 52 that matches the outer shape of the coil portion 12. and, wherein the upper and lower edge of the counter-collar 10 side of the guide portion 58 is formed on the outer arcuate surface 59 of arcuate shape centered on the axis of the respective collar 10, said outer arcuate surface 59 and the guide pin 60 abuts the spring An armrest height adjusting device provided on the side plate 50 of the mounting bracket 13. In Claim 1, the fitting groove 53 of the stay 14 is formed by providing a convex portion 54 between a pair of plate portions 51, and an upright surface on the insertion side of the fixed side end portion 15 of the convex portion 54. 56 is a notch formed in accordance with the shape of the bent portion 57 at the boundary between the fixed side end portion 15 and the coil portion 12, and the height adjustment of the armrest configured so that the bent portion 57 is in close contact with the standing surface 56. apparatus. 3. The armrest height adjusting device according to claim 1, wherein an inner width of the fitting groove 53 is adjusted to a width of the fixed side end portion 15.

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