Angle-adjustable armrest

Abstract

To provide an angle-adjustable armrest which can securely switch fastening and loosening of a lock spring.SOLUTION: An angle-adjustable armrest has: a cylindrical drum, which has an opening with an oblique part and is fixed on a sheet frame; an armrest frame, which has a hole through which the drum penetrates and can turn, about the drum, in a first turning direction and in a second turning direction opposite the first direction; a lock spring, wound in a close contact state on the outer peripheral surface of the drum, to keep a fixed end at one end, and a free end at the other end; and a bracket fixed to the armrest frame. The drum opening extends in a direction along the turning direction of the armrest, makes an edge of a direction vertical to that direction form a ramp, and has a first part the fixed end of which is fixed on the bracket, and the free end of which extends from outside of the drum to the inside through the opening and a second part extending in an opposite direction, and the bracket has an opening through which the second part passes.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to an armrest that is attached to a seat frame and can be adjusted to any angle. [Background technology]

[0002] There are some models that have a function that allows the armrest attached to the seat frame to be continuously adjusted (Patent Documents 1, 2, and 3).

[0003] The armrest of the prior art (Patent Document 1) is capable of continuously adjusting the angle and utilizes two cams with special shapes. By bringing these cams into contact with each other, the armrest, which is attached rotatably, is restricted to turning in one direction, but can be freely reversed, allowing the armrest to be positioned at a predetermined angle in a continuous manner.

[0004] Another prior art armrest (Patent Document 2) is a so-called storable type armrest (see Figures 1 and 2 of Patent Document 2), in which a coil spring is wound around a lock drum (12) to rotate it. The free end (13a) of the coil spring is pushed down by an auxiliary cam on the cover plate, maintaining the coil spring in a loosening direction, thereby releasing the locked state. When the free end returns to its initial position by the return cam of the lock drum, the armrest returns to the locked state.

[0005] Another prior art armrest device (Patent Document 3) also has a coil spring (7) wound around a fixed body (6), and when the armrest exceeds the angle adjustment range, the coil spring is held in a certain relaxed state, allowing the armrest to rotate downward, and when the armrest returns to its initial position, the coil spring is guided by a spring guide and returned to its original state.

[0006] Some large trucks are equipped with sleeping spaces. The sleeping space is located at the top rear of the driver's seat, so the armrest may be used as a step to move up to the sleeping space. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2004-345374 [Patent Document 2] WO2014 / 024709 [Patent Document 3] Patent No. 4446442 Summary of the Invention [Problem to be solved by the invention]

[0008] In the armrest of Patent Document 1, the angle can be adjusted steplessly by using two cams, and the overall design is compact, but the shape of the two cams must be special.

[0009] The armrest in Patent Document 2 (Figure 1) has a locking spring wound around a locking drum and adjusted to a specified angle. However, because it has a large number of parts, such as a spring retainer and a base plate, it requires more assembly work. In addition, to release the lock, it is necessary to provide a large clearance to ensure a clearance when loosening the spring. Furthermore, a force in the pulling direction is easily applied to the fixed part of the spring, making it difficult to ensure sufficient angle retention of the armrest.

[0010] The armrest device of Cited Document 3 also has a coil spring (7) wound around a fixed body (6), but the contact between the free end (7a) of the coil spring and the first acting surface (6a) is not strong, allowing the winding to slide smoothly when tightening or loosening, resulting in an excellent operating feel. However, when used in a vehicle, the maintenance of the tightened state may remain uncertain due to vehicle vibrations.

[0011] When an angle-adjustable armrest is installed in a large truck and used as a step to move to a sleeping area, excessive force may act on the coil spring installed in the armrest, causing the fixed end to fail.

[0012] Therefore, an object of the present invention is to provide an angle-adjustable armrest that can be locked and unlocked without using two cams with special shapes.

[0013] Another object of the present invention is to provide an angle-adjustable armrest that can reduce the number of parts, make it compact, and simplify the assembly process.

[0014] Furthermore, another object of the present invention is to provide an angle-adjustable armrest that can securely hold a lock spring even when the lock spring is arranged around a drum, and can sufficiently maintain the angle of the armrest.

[0015] Furthermore, another object of the present invention is to provide an angle-adjustable armrest in which the lock spring can be reliably switched between tightening and loosening.

[0016] Furthermore, another object of the present invention is to provide an angle-adjustable armrest that can reliably lock the fixed end of the lock spring even when excessive weight is applied to the armrest. [Means for solving the problem]

[0017] The armrest that achieves the above object is an angle-adjustable armrest that is attached to a seat frame, a cylindrical drum having an opening with an inclined portion and fixed to the seat frame; an armrest frame having a hole through which the drum passes and rotatable about the drum in a first rotation direction and a second rotation direction opposite to the first direction; a lock spring that is wound tightly around the outer circumferential surface of the drum, one end of which is a fixed end and the other end of which is a free end; a bracket positioned near the lock spring, having an opening through which the free end of the drum passes, and fixing the fixed end of the drum to the armrest frame; The present invention is configured as follows.

[0018] The opening of the drum extends from one edge to the other edge in a direction along the rotation direction of the armrest frame, the other edge having the inclined portion in a direction perpendicular to that direction, and the opening of the drum having a step portion.

[0019] The fixed end of the lock spring has an extension portion that extends radially outward from the drum and a bent portion whose tip is bent in a direction parallel to the surface of the armrest frame, and the bracket fixes the extension portion and bent portion of the fixed end to the armrest frame.

[0020] The free end has a first portion that passes through the opening in the drum and enters the interior of the drum, and a second portion that extends from the first portion through the opening and outwardly through the opening in the bracket.

[0021] The opening of the bracket comprises a first opening extending from one end to the other end along the rotation direction of the armrest frame, and a second opening extending from the other end of the first opening along a direction perpendicular to the rotation direction, and it is preferable that the first opening is connected to the second opening via an inclined portion.

[0022] Preferably, the direction of the second portion of the free end and the direction of extension of the fixed end are the same.

[0023] The lock spring is wound around the drum so that when the armrest frame is rotated in the second direction to rotate the bracket, the lock spring tightens, and conversely, when the armrest frame is rotated in the first direction to rotate the bracket, the lock spring loosens its tightening.

[0024] When the armrest frame rotates in a first rotation direction, the bracket rotates relative to the drum, and the second part of the free end passing through the first opening moves to the other end of the first opening and then to the second opening, which releases the lock spring from tightening against the drum and allows the armrest frame to rotate freely.

[0025] When the second portion of the free end is positioned in the second opening of the bracket portion and the armrest frame is rotated in the second rotation direction, the first portion of the free end is pushed down by the inclined portion of the drum, and when the second portion of the free end moves to the first opening, the lock spring tightens the drum, preventing the rotation.

[0026] When a first portion of the free end abuts against the inclined portion of the drum and a second portion of the free end passing through the first opening is positioned at one end of the first opening of the bracket, rotation of the armrest frame in the second direction increases the tightening of the lock spring and is prevented.

[0027] When the second portion of the free end abuts against the step of the drum and the second portion of the free end protruding from the first opening is positioned at the other end of the first opening of the bracket portion, rotation of the armrest frame in the first direction weakens the tightening of the lock spring, so that the second portion of the free end moves into the second opening of the bracket and climbs over the step of the drum, the tightening of the lock spring is released, and the armrest frame becomes free to rotate in the first direction.

[0028] The bracket may comprise a horizontal portion fixed to the armrest frame and a vertical portion perpendicular to the armrest frame, a plate being fixed to the vertical portion, and the plate having the first opening and the second opening.

[0029] The horizontal portion preferably has a groove for receiving the extension of the fixed end.

[0030] It is preferable that a fixing portion is provided for fixing the horizontal portion to the armrest frame from above, and that the fixing portion has a claw portion on the opposite side to the vertical portion.

[0031] The claw portion fits into an opening formed in the armrest frame, and can firmly fix the horizontal portion of the bracket portion to the armrest frame.

[0032] A second portion of the free end is sandwiched between the second opening of the bracket and the step of the opening of the drum, thereby restricting the position of the armrest in the stored state. [Effects of the Invention]

[0033] The angle-adjustable armrest of the present invention is made up of a drum, a lock spring wound around the drum, and a bracket, and therefore has a small number of parts, making it easy to manufacture and assemble.

[0034] The shape of the opening in the drum through which the free end of the lock spring passes and the shape of the opening in the bracket make it possible to prevent or release the rotation of the armrest, and furthermore, the shape of the bracket only needs to cover the free end and fixed end of the lock spring, which simplifies the parts.

[0035] Furthermore, by fixing the fixed end of the lock spring to the bracket, the lock spring is securely held in place and the angle of the armrest is sufficiently maintained. This means that the fixed end of the lock spring can be securely fixed even in large trucks where the armrest is used as a step and a strong pulling force is generated on the fixed end of the lock spring.

[0036] Furthermore, because there is an inclined portion between the first opening and the second opening of the bracket, the second portion of the lock spring located at the first opening of the bracket can move smoothly to the second opening, and conversely, the second portion of the lock spring located at the second opening of the bracket can move smoothly to the first opening, ensuring reliable switching between tightening and loosening of the lock spring. [Brief explanation of the drawings]

[0037] [Figure 1] Figure 1(a) is a perspective view showing a state in which a conventional armrest mechanism unit is attached to an armrest frame, and Figure 1(b) is a perspective view showing a state in which the armrest mechanism unit of Figure 1(a) is attached to an armrest frame. [Figure 2] FIG. 2(a) is a perspective view of the armrest of the present invention attached to a seat frame, and FIG. 2(b) is a perspective view of the armrest of the present invention with the outer cover removed. [Figure 3] FIG. 3 is an exploded view of the armrest of the present invention attached to the seat frame. [Figure 4] FIG. 4 is a perspective view of the drum constituting the present invention. [Figure 5] FIG. 5 is a front view of the drum constituting the present invention. [Figure 6] FIG. 6 is a perspective view of the drum and bracket with the lock spring attached to the armrest frame. [Figure 7] FIG. 7 is a perspective view of the drum and bracket to which the lock spring is attached, as viewed from below. [Figure 8] FIG. 8 shows a bracket with a plate attached to the armrest frame. [Figure 9] FIG. 9 is a perspective view of the drum and bracket with the lock spring attached to the armrest frame. [Figure 10] FIG. 10 is a partial plan view of the drum and bracket to which the lock spring is attached, which are attached to the armrest frame. [Figure 11]Figure 11(a) shows a state in which a base plate is attached to a drum with a lock spring attached to the armrest frame, and Figure 11(b) shows a state in which the armrest frame in Figure 11(a) has been rotated to a limit position relative to the base plate. [Figure 12] FIG. 12 is a partial cross-sectional view of the armrest frame taken along line AA in FIG. [Figure 13] 12 is a partial cross-sectional view of the armrest frame taken along line CC in FIG. [Figure 14] 14 is a partial cross-sectional view of the armrest frame taken along line BB in FIG. [Figure 15] FIG. 15 is a development view showing the relative positions of the drum, the end of the lock spring, and the bracket as the armrest frame rotates. DETAILED DESCRIPTION OF THE INVENTION

[0038] FIG. 2(a) shows a perspective view of the angle-adjustable armrest 10 (hereinafter simply referred to as "armrest") of the present invention attached to a seat frame, and FIG. 2(b) shows a perspective view with the outer skin O removed.

[0039] The armrest 10 is rotatably attached to a seat frame material S (not shown) and is normally arranged to be positioned along the seat frame material S. When used by a person sitting in the seat, the armrest 10 can be rotated in the direction indicated by the arrow and held in a predetermined position.

[0040] In large trucks with sleeping spaces, the armrests are used as steps to move into the sleeping space, which means that more weight is placed on the armrests than if they were simply placed on the floor.

[0041] FIG. 3 is an exploded view of the armrest 10 attached to the seat frame S.

[0042] The armrest 10 has an armrest frame 12, a drum 20 around which a lock spring 30 having a free end 31 and a fixed end 32 is wound in a tightened state, and a bracket part 40 that houses the free end of the lock spring 30 and fixes the fixed end.

[0043] As shown in FIG. 3, an attachment A is fixed to a seat frame S. A base plate 11, to which a drum 20 is attached, is fixed to the attachment A. The base plate 11 is provided with a protrusion 11a. As described below, the protrusion 11a fits into a recess 22' at the bottom of the drum 20, and when the base plate 11 is attached to the attachment A, the drum 20 is fixed to the attachment A, i.e., the seat frame S.

[0044] The armrest frame 12 has a hole 13 through which a drum 20 passes. The drum 20 passes through the hole 13 and is attached to the base plate 11 by a screw 14 (see FIG. 12).

[0045] Covers O1, O2, and O3 are arranged and fixed to the armrest frame 12, and an outer skin O is further fixed thereto, thereby forming the appearance of the armrest.

[0046] The armrest frame 12 to which the various members are attached is rotatable about the drum 20 in a first rotation direction from a horizontal position to a vertical position and in a second rotation direction from the vertical position to a horizontal position.

[0047] Next, each member will be described in detail.

[0048] A perspective view of drum 20 is shown in Fig. 4, and its front view is shown in Fig. 5. Drum 20 is cylindrical and has an opening 21. Opening 21 has a step 23 on an edge 22 that is aligned with the rotation direction of the armrest frame. Furthermore, opening 21 has an inclined portion 24 in a direction perpendicular to the rotation direction. This inclined portion 24 is inclined at an acute angle with respect to edge 22.

[0049] A lock spring 30 is tightly wound around the outer circumferential surface of the drum 20. Figure 6 shows the drum 20 with the lock spring 30 wound around it attached to the armrest frame 12. As shown in Figure 6, a bracket 40 is fixed near the drum 20.

[0050] As shown in Figures 6 and 10, the free end 31 of the lock spring 30, which is wound tightly around the outer circumferential surface of the drum 20, has a shape in which it passes through opening 21 of the drum 20, extending from the outside to the inside of the drum 20 (the portion extending inward through opening 21 is referred to as "portion A"), then changes direction and passes through opening 21 (the portion passing through opening 21 is referred to as "portion B"), and further extends through an opening 44 formed in a plate 43 fixed to a bracket 40, which will be described below (the portion passing through opening 44 is referred to as "portion C").

[0051] 7, the fixed end 32 has an extension 32a that extends radially outward from the cylindrical drum and a bent portion 32b that bends to be parallel to the surface of the armrest frame 12. The extension 32a and the bent portion 32b are fixed to the armrest frame 12 as described below.

[0052] It is desirable that the extension direction of the fixed end 32 is the same as the direction of the free end portion C. This is because, since these are in the same direction, the free end and the fixed end can be accommodated within the area of ​​the armrest frame, thereby making the entire armrest smaller.

[0053] 7, a plurality of recesses are provided on the bottom surface 21 of the drum 20. When the drum 20 passes through the opening 13 of the armrest frame 12, the recesses 22' on the bottom engage with the protrusions 11a of the base plate 11, forming a single unit.

[0054] As shown in Figures 9 and 11, the base plate 11 has a foot 11b extending opposite to the protrusion 11a, and this foot 11b is inserted into a hole in the attachment A. This makes the drum 20 one piece with the seat frame material S. As described above, the armrest frame 12 is free to rotate about the drum 20 in a first rotation direction from a horizontal position to a vertical position and in a second rotation direction from the vertical position to a horizontal position, but to prevent this rotation from exceeding a predetermined limit, as shown in Figure 11, a protrusion 11c is provided on the base plate 11 on the armrest frame 12 side, and a protrusion 12' that abuts against this is provided on the armrest frame 12, thereby preventing excessive rotation.

[0055] A bracket 40 is fixed to the armrest frame 12 by a fixing portion rivet 15 via a fixing plate 47, adjacent to the lock spring 30 wound around the drum 20 (see Figures 6, 13, and 14). The bracket 40 is composed of a vertical portion 41 facing the lock spring 30 and a horizontal portion 42 fixed to the armrest frame 12 (Figures 3 and 7).

[0056] A plate 43 is fixed to the vertical portion 41. As shown in Figures 6 and 8, this plate 43 has an opening through which the free end 31 of the lock spring protrudes. This opening consists of a first opening 44 extending from one end 44a to the other end 44b along the rotation direction of the armrest frame, and a second opening 45 extending from the other end 44b in a direction perpendicular to the rotation direction of the armrest frame. The first opening 44 is connected to the second opening 45 via an inclined portion 46 (see Figure 8).

[0057] Additionally, the plate 43 has a groove 43' that receives the fixed end 32 of the locking spring.

[0058] The plate and bracket may be integrated, which has the effect of reducing the number of parts.

[0059] The free end 31 of the lock spring 30 protruding outward from the opening 21 protrudes from an opening 44 of the bracket 40 (see FIGS. 6 and 8).

[0060] 7, the extension 32a of the fixed end 32 fits into a groove 42' provided in the center of the horizontal portion 42 of the bracket 40. The bent portion 32b of the fixed end 32 is positioned along the rear end of the horizontal portion 42.

[0061] The fixing plate 47 is positioned to cover the horizontal portion 42 of the bracket 40 from above, and the horizontal portion 42, i.e., the bracket 40, is fixed to the armrest frame 12 by the bolts 15 (see FIGS. 6, 13, and 14).

[0062] The fixing plate 47 has two claws 47' on the side opposite to the vertical portion 41. The two claws are provided to accommodate the case where the bending portion 32b is bent so as to extend in the opposite direction.

[0063] As shown in Figure 7, the claw portion 47' is curved to grip the bent portion 32b of the fixing portion 32, and is inserted into a hole 12' provided in the armrest frame 12, as described below (see Figure 10).

[0064] The claws 47' of the fixing portion plate 47 ensure that the fixing end 32 is held securely even if a force that would cause the fixing portion of the lock spring to come off is applied.

[0065] In this way, by making the tip of the fixed end of the lock spring a bent part and fixing it with a fixed part plate, the function of the lock spring is not impaired even if excessive load is applied to the lock spring when the armrest is used as a step stool, making it impossible to fix the fixed end.

[0066] In addition to the above example, the lock spring 30 may have a shape that extends from the lock spring 30 side through the opening 44 of the bracket 40, then extends in the opposite direction to the first direction, passes through the opening 44, and further extends through the opening 21 of the drum 20. Alternatively, the free end 31 may be bifurcated, one of which passes through the opening 21 of the drum 20 and the other of which passes through the opening 44 of the plate 43 of the bracket 40.

[0067] The operation of the armrest 10 of the present invention will now be described with reference to FIG.

[0068] When the armrest frame 12 is rotated in a direction that tightens the lock spring 30, the bracket 40 (plate 43) fixed to the armrest frame 12 moves relative to the drum 20 and the lock spring 30. As a result, portion C of the free end 31 of the lock spring 30 is positioned at one end 44a of the opening 44 (Figure 15(2)). When portion A of the free end 31 abuts against the inclined portion 24 of the drum 20 (see Figure 15(1)), the free end 31 is fixed. Therefore, even if an attempt is made to rotate the armrest frame 12 (bracket 40) in a direction that tightens the lock spring 30, it cannot be rotated, and the armrest frame 12 is in a locked state.

[0069] Next, the armrest frame 12 is rotated in the direction opposite to the direction tightening the lock spring 30, that is, in the direction to release the tightening of the lock spring 30. At this time, although the lock spring 30 tightens the drum 20, the armrest frame 12 can still rotate.

[0070] The bracket 40 fixed to the armrest frame 12 moves relative to the drum 20 and the lock spring 30, so that the portion C of the free end 31 is positioned at the other end 44b of the opening 44 (see Figure 15(2)). At the same time, the portion B of the free end 31 abuts against the step 23 of the drum 20.

[0071] In this state, if the armrest frame 12 is further rotated in a direction that releases the tightening of the lock spring 30, the tightening of the lock spring 30 weakens, and a force is generated in the lock spring 30 in a direction that separates the free end 31 and the fixed end 32. As a result, the portion C of the free end 31 quickly moves into the opening 44 due to the inclined portion 45, and the portion B of the free end 31 climbs over the step 23.

[0072] The free end 31 is sandwiched between the opening 44 of the bracket 40 and the opening 21 of the drum 20, restricting the position of the armrest in the stowed state (Fig. 15(3)). While restricted, the lock spring 30 continues to release its clamping force on the drum 20, allowing the armrest frame 12 to rotate freely in either direction. In other words, the lock is released.

[0073] In this way, the lock spring 30 tightens the drum 20 until the armrest frame 12 is rotated, but when the lock spring 30 is rotated in the direction to release the tightening, the portion C of the free end 31 quickly moves to the opening 44, loosening the tightening of the lock spring 30 to the drum 20 and immediately releasing the lock. This ensures that the lock spring can be switched between tightening and loosening accurately.

[0074] Next, when the armrest frame 12 in the unlocked state is rotated in the direction of tightening the lock spring 30, the portion A of the free end 31 of the lock spring 20 (which rotates together with the armrest frame 12 because the lock spring is not tightening the drum in this state) comes into contact with the inclined portion 24 of the drum 20 (the angle between the edge 22 and the inclined portion 24 is an acute angle) (Figure 15(4)).

[0075] When the armrest frame 12 is further rotated, the portion A of the free end 31 is pressed downward by the inclined portion 24, so that it returns to the position it was in before climbing over the step portion 23, and the portion C of the free end 31 returns from the opening 45 to the opening 44. At this time, the lock spring 30 tightens the drum 20 again. In this state, the armrest frame 12 cannot rotate and is locked.

[0076] As described above, by providing the opening 21 in the drum 20 through which part of the free end 31 of the lock spring 20 passes, and further providing the openings 44, 45 and the inclined portion 46 in the bracket 40 through which part of the free end 31 passes, it is possible to lock or unlock the rotation of the armrest frame and adjust the angle of the armrest frame.

[0077] In the present invention, the fixed end of the lock spring is bent into an L shape and fixed to a bracket, so that even if excessive force in the pulling direction is generated on the lock spring when the armrest is stepped on like a step, this can be countered and the angle holding force of the armrest can be secured.

[0078] When the lock spring 30 is configured to extend from the lock spring 30 side through the opening 44 in the plate 43 of the bracket 40, then extend in the opposite direction to the first extension direction, through the opening 44, and further extend through the opening 21 of the drum 20, the operation is as follows.

[0079] When the armrest frame 12 is rotated in a direction that tightens the lock spring 30, the bracket 40 fixed to the armrest frame 12 moves relative to the drum 20 and the lock spring 30, as in the above-described embodiment. As a result, the free end 31 of the lock spring 30 (corresponding to the above-described portion C) is positioned at one end 44a of the opening 44. When the free end 31 (corresponding to the above-described portion B) abuts against the inclined portion 24 of the drum 20, the free end 31 is fixed. Therefore, even if an attempt is made to rotate the armrest frame 12 (bracket 40) in a direction that tightens the lock spring 30, it cannot be rotated, and the armrest frame 12 is locked.

[0080] Next, when the armrest frame 12 is rotated in a direction that releases the tightening of the lock spring 30, the bracket 40 fixed to the armrest frame 12 moves relative to the drum 20 and the lock spring 30. As a result, the portion of the free end 31 (corresponding to the portion A described above) is positioned at the other end 44b of the opening 44. At the same time, the portion of the free end 31 (corresponding to the portions B and C described above) abuts against the step 23 of the drum 20.

[0081] In this state, if the armrest frame 12 is further rotated in a direction that releases the tightening of the lock spring 30, the tightening of the lock spring 30 will weaken, and the portion of the free end 31 (corresponding to the above-mentioned portion B) will move over the step portion 23, and the portion of the free end 31 (corresponding to the above-mentioned portion A and portion C) will move to the opening 44. At this time, the lock spring 30 will release its tightening on the drum 20, and the lock will be released.

[0082] Next, when the armrest frame 12, which is in the unlocked state, is rotated in the direction of tightening the lock spring 30, the free end 31 of the lock spring 20 (corresponding to the above-mentioned part B) that rotates together with the armrest frame 12 comes into contact with the inclined portion 24 of the drum 20.

[0083] Furthermore, when the armrest frame 12 is rotated, the portion of the free end 31 (corresponding to the above-mentioned portion B) is pressed downward by the inclined portion 24, and returns to the position it was in before climbing over the step portion 23, and the portion of the free end 31 (corresponding to the above-mentioned portion C) returns from the inclined portion 46 to the opening 44. At this time, the lock spring 30 tightens the drum 20 again, so the portion of the free end 31 (corresponding to the above-mentioned portion C) is positioned in the opening 44. In this state, the armrest frame 12 cannot rotate and is locked.

[0084] When the free end 31 is bifurcated, one of which passes through the opening 21 in the drum 20 and the other of which passes through the opening 44 in the plate 43 of the bracket 40, the operation is as follows.

[0085] When the armrest frame 12 is rotated in the direction that tightens the lock spring 30, the bracket 40 fixed to the armrest frame 12 moves relative to the drum 20 and lock spring 30, as in the above-described embodiment, but one portion of the free end 31 of the lock spring 30 is positioned in the opening 44. When the other portion of the free end 31 abuts against the inclined portion 24 of the drum 20, the free end 31 is fixed, and the armrest frame 12 (bracket 40) cannot be rotated in the direction that tightens the lock spring 30, and the armrest frame 12 is in a locked state.

[0086] Next, when the armrest frame 12 is rotated in a direction that releases the tightening of the lock spring 30, the bracket 40 fixed to the armrest frame 12 moves relative to the drum 20 and the lock spring 30. One portion of the free end 31 is located at the other end 44b of the opening 44, and at the same time, the other portion of the free end 31 abuts against the step 23 of the drum 20.

[0087] In this state, if the armrest frame 12 is further rotated in a direction that releases the tightening of the lock spring 30, the tightening of the lock spring 30 will be weakened, and the other part of the free end 31 will move over the step 23, while one part of the free end 31 will move into the opening 44. At this time, the lock spring 30 will no longer be tightened to the drum 20, and will be unlocked.

[0088] Next, when the armrest frame 12 in the unlocked state is rotated in the direction of tightening the lock spring 30, the other part of the free end 31 of the lock spring 20 that rotates together with the armrest frame 12 comes into contact with the inclined portion 24 of the drum 20.

[0089] When the armrest frame 12 is further rotated, the other portion of the free end 31 is pressed downward by the inclined portion 24, so that it returns to the position it was in before climbing over the step portion 23, and one portion of the free end 31 returns from the opening 44 to the opening 45. At this time, the lock spring 30 tightens the drum 20 again, so that one portion of the free end 31 is positioned at the opening 44. In this state, the armrest frame 12 cannot rotate and is locked.

[0090] The angular positions in the above embodiment are merely examples, and it goes without saying that the shape of the opening in the drum and the shape of the opening in the bracket can be changed as desired depending on the locked and unlocked positions.

[0091] The angle-adjustable armrest of the present invention can be incorporated into a vehicle seat, and can also be applied to an ordinary chair. [Explanation of symbols]

[0092] A Attachment 10 Armrest 11 Base Plate 11' convex part 12 Armrest frame 13 holes 14 volts 15 volts 20 drums 21 Aperture 22 En 22' recess 23 Step section 24 Slope 30 Locking spring 31 Free end 32 Fixed end 32a Extension part 32b Bend part 40 Bracket 41 Vertical section 42 Horizontal part 43 Plate 44 Opening 44a one end 44b other end 45 Opening 46 Slope section 47 Fixing plate 50 Drum bracket

Claims

1. An angle-adjustable armrest attached to a seat frame, a cylindrical drum having an opening with an inclined portion and fixed to the seat frame; an armrest frame having a hole through which the drum passes and rotatable about the drum in a first rotation direction and a second rotation direction opposite to the first direction; a lock spring that is wound tightly around the outer circumferential surface of the drum, one end of which is a fixed end and the other end of which is a free end; a bracket positioned near the lock spring, having an opening through which the free end of the lock spring passes, and fixing the fixed end of the lock spring to the armrest frame; and The opening of the drum extends from one edge to the other edge in a direction along the rotation direction of the armrest frame, and the other edge has the inclined portion in a direction perpendicular to the direction, The opening in the drum has a step, The fixed end of the lock spring has an extension portion that extends radially outward from the drum and a bent portion whose tip is bent in a direction parallel to the surface of the armrest frame, the bracket fixes the extension portion and the bent portion of the fixed end to the armrest frame; The free end has a first portion that passes through the opening in the drum and enters the interior of the drum, and a second portion that extends from the first portion through the opening and outwardly through the opening in the bracket. the opening of the bracket comprises a first opening extending from one end to the other end along the rotation direction of the armrest frame, and a second opening extending from the other end of the first opening along a direction perpendicular to the rotation direction, the first opening is connected to the second opening via an inclined portion; The direction of the second portion of the free end and the direction of extension of the fixed end are the same, the lock spring is wound around the drum so that when the armrest frame is rotated in the second direction to rotate the bracket, the lock spring tightens, and conversely, when the armrest frame is rotated in the first direction to rotate the bracket, the lock spring loosens. When the armrest frame is rotated in a first rotation direction to rotate the bracket relative to the drum, the second portion of the free end passing through the first opening moves to the other end of the first opening and further to the second opening, whereby the lock spring is released from tightening on the drum, and the armrest frame becomes rotatable; When the armrest frame is rotated in the second rotation direction while the second portion of the free end is positioned in the second opening of the bracket portion, the first portion of the free end is pressed down by the inclined portion of the drum, and when the second portion of the free end moves to the first opening, the lock spring tightens the drum, preventing the rotation. Angle adjustable armrests.

2. 2. The angle-adjustable armrest according to claim 1, wherein when a first portion of the free end abuts against the inclined portion of the drum and a second portion of the free end passing through the first opening is positioned at one end of the first opening of the bracket, rotation of the armrest frame in the second direction is prevented by tightening of the lock spring.

3. 2. The angle-adjustable armrest according to claim 1, wherein when the second portion of the free end abuts against the step of the drum and the second portion of the free end protruding from the first opening is located at the other end of the first opening of the bracket portion, rotation of the armrest frame in the first direction weakens the tightening of the lock spring, so that the second portion of the free end moves into the second opening of the bracket and climbs over the step of the drum, the tightening of the lock spring is released, and the armrest frame becomes free to rotate in the first direction.

4. The bracket includes a horizontal portion fixed to the armrest frame and a vertical portion perpendicular to the armrest frame, the plate being fixed to the vertical portion, and the plate having the first opening and the second opening. The angle-adjustable armrest according to claim 1.

5. the horizontal portion has a groove that receives the extension portion of the fixed end; A fixing portion is provided to fix the horizontal portion to the armrest frame from above, The fixing portion has a claw portion on the opposite side to the vertical portion, 5. The angle-adjustable armrest according to claim 4, wherein the claw portion fits into an opening formed in the armrest frame to firmly fix the horizontal portion of the bracket portion to the armrest frame.

6. 2. The angle-adjustable armrest according to claim 1, wherein the second portion of the free end is sandwiched between the second opening of the bracket and the step of the opening of the drum, thereby restricting the position of the armrest in a stored state.

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