Screw lock type hinge mechanism

Abstract

To provide a hinge mechanism which can provide a difference in torque by a rotation direction and in which an operator can optionally switch the torque of rotation.SOLUTION: A hinge mechanism includes a shaft member 10, a plurality of lock screws 20, a fixing member 30, a rotation member 40, and a holding member 50. When torque in a fastening direction is applied to the rotation member, and if the torque is a specified value or less, the rotation member does not rotate in the fastening direction. When the torque exceeds the specified value, the rotation member rotates in the fastening direction, and if torque in a loosening direction is applied to the rotation member, the rotation member rotates in the loosening direction. A free-end locking part 52 which can lock a free end 22 of each of the lock screws on a loosening side is provided on the holding member. Torque of rotation of the rotation member is adjusted by switching between a lock state where the free end 22 is not locked with the free-end locking part 52 and a lock release state where the free end 22 is locked with the free-end locking part.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a spring lock hinge mechanism that uses a spring lock mechanism to adjust the torque. [Background technology]

[0002] A hinge mechanism is known as a mechanism that connects two members in a state where they can rotate relative to each other. Some hinge mechanisms have a variable torque when rotating.

[0003] For example, Figure 1 of Patent Document 1 describes a hinge mechanism including a shaft 10, a first bracket 13 attached to one end of the shaft 10, and a second bracket 17 fixed to the other end of the shaft 10. Flat portions 11 and 12 are provided on the outer circumferential surface of the one end side of the shaft 10, and first bracket 13 is provided with a spring portion 16 that is rotatably attached to the one end of the shaft 10 and that corresponds to the flat portions 11 and 12 so as to be able to elastically contact the flat portions 11 and 12.

[0004] In the hinge mechanism of Patent Document 1, as shown in Figures 2(a) and (b) of the same document, when the spring portion 16 overlaps either the flat portion 11 or 12, the torque required to rotate the second bracket 17 relative to the first bracket 13 is small. On the other hand, as shown in Figures 2(b) and (c) of the same document, when the spring portion 16 does not overlap either the flat portion 11 or 12, the elastic force of the spring portion 16 is applied to the shaft 10, so that the torque required to rotate the second bracket 17 relative to the first bracket 13 is large.

[0005] FIG. 10 of Patent Document 2 describes a damper device for a hinge mechanism, which includes a case 12, a shaft 13 rotatably accommodated in the case 12, a valve element 15 disposed between the case 12 and the shaft 13, and a viscous fluid filled inside the case 12. The case 12 has a pair of support portions 12a, 12a, and the shaft 13 has a pair of blade portions 13a, 13b. The blade portions 13a, 13b have generally V-shaped grooves 13c, 13c formed at their tips. The valve element 15 has generally V-shaped protrusions 15a, 15a. The protrusions 15a, 15a are recessed into the grooves 13c, 13c. A recess 15c is formed on an inclined surface 15b on one side of the protrusion 15a, but no recess is formed on an inclined surface 15b' on the opposite side.

[0006] In the damper device (hinge mechanism) of Patent Document 2, as shown in FIG. 10(a) of the same document, when the shaft 13 rotates clockwise (direction B) relative to the case 12, the inclined surface 15b' and the inclined surface 13d' come into contact with each other. However, because the inclined surface 15b' does not have a recess, a flow path through which the viscous fluid can freely pass is not formed between the chambers A and B. Therefore, the minute gap between the support portion 12a and the shaft 13 acts as an orifice, and a damping function is exerted (torque is increased). On the other hand, as shown in FIG. 10(b) of the same document, when the shaft 13 rotates counterclockwise (direction A) relative to the case 12, the inclined surface 15b and the inclined surface 13d come into contact with each other. At this time, the inclined surface 15b has a recess 15c, so a flow path through which the viscous fluid can freely pass is formed between the chambers A and B. Therefore, a damping function is not exerted (torque is reduced) for rotation in the direction A. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Utility Model Application Publication No. 06-058231 [Patent Document 2] Japanese Patent Application Laid-Open No. 2009-185846 Summary of the Invention [Problem to be solved by the invention]

[0008] However, with the hinge mechanism of Patent Document 1, the torque does not change unless the second bracket 17 is rotated relative to the first bracket 13 within a specific range. In other words, in order to change the torque, the second bracket 17 needs to be rotated relative to the first bracket 13 within a specific range. The hinge function of Patent Document 1 does not allow the operator of the hinge mechanism to arbitrarily switch the torque. In addition, with the hinge mechanism of Patent Document 1, it is not possible to create a difference between the torque when rotating the second bracket 17 to one side relative to the first bracket 13 and the torque when rotating it to the other side.

[0009] In contrast, the hinge mechanism of Patent Document 2 makes it possible to provide a difference between the torque when rotating shaft 13 to one side (direction B) relative to case 12 and the torque when rotating shaft 13 to the other side (direction A). However, even with the hinge mechanism of Patent Document 2, it is impossible for an operator of the hinge mechanism to arbitrarily switch the torque. In addition, the hinge mechanism of Patent Document 2 is a precision part that requires high dimensional accuracy, which presents the problem of high manufacturing costs.

[0010] The present invention has been made to solve the above problems, and provides a hinge mechanism that allows a difference in torque depending on the rotation direction and allows an operator to arbitrarily switch the torque during rotation. Another object of the present invention is to provide such a hinge mechanism with a simple and low-cost structure. [Means for solving the problem]

[0011] The above issues are: A shaft member; a plurality of lock springs each made of a coil spring having an inner diameter smaller than the outer diameter of the shaft member, the lock springs being wound around the outer periphery of the shaft member in an elastically expanded state; a fixed member that is fixed so as not to move relative to the shaft member; a rotating member attached to the shaft member in a state that allows it to rotate relatively; a holding member having a fixed end holding portion for holding the fixed end of the lock spring and fixed in a state where it does not move relative to the rotating member; Equipped with When torque is applied to the rotating member in a direction in which the lock spring winds up (hereinafter referred to as the "tightening direction"), if the torque is below a specified value, the rotating member will not rotate in the tightening direction. If the torque exceeds the specified value, the lock spring will slip relative to the shaft member, and the rotating member will rotate in the tightening direction. When torque is applied to the rotating member in the direction opposite to the tightening direction (hereinafter referred to as the "loosening direction"), the lock spring slips relative to the shaft member, causing the rotating member to rotate in the loosening direction. The holding member is provided with a free end locking portion that can forcibly displace the free ends of the lock springs toward the loosened side for each lock spring to lock them, By switching between a locked state in which the free end is not locked to the free end locking part and an unlocked state in which the free end is locked to the free end locking part, it is possible to adjust the torque when rotating the rotating member relative to the fixed member. A spring lock hinge mechanism characterized by This is solved by providing

[0012] In the hinge mechanism of the present invention, when the free end of the lock spring is engaged with the free end engagement portion (when the free end is in the unlocked position), the lock spring expands in diameter and becomes loose (unlocked state) relative to the shaft member, so that the rotating member can be rotated in either direction relative to the fixed member with a small torque.

[0013] In contrast, when the free end of the lock spring is not engaged with the free end engagement portion (when the free end is in the locked position), the lock spring tightens the shaft member (locked state). Even in this locked state, as described below, if the lock spring is displaced in the loosening direction (i.e., if torque in the loosening direction is applied to the rotating member), even a relatively small torque will cause the lock spring to slip relative to the shaft member, allowing the rotating member to rotate in that direction (loosening direction). However, if the lock spring is displaced in the tightening direction (i.e., if torque in the tightening direction is applied to the rotating member), a torque exceeding a significantly large specified value must be applied in order for the lock spring to slip relative to the shaft member, and the rotating member cannot be rotated in that direction (tightening direction).

[0014] In this way, the hinge mechanism of the present invention can provide a difference in torque depending on the rotation direction. Hereinafter, among the rotation directions of the hinge mechanism, the direction in which the torque becomes large (high) may be referred to as the "high torque direction," and the direction in which the torque becomes small (low) may be referred to as the "low torque direction."

[0015] Furthermore, in the hinge mechanism of the present invention, the operator can select whether or not to lock the free end of the lock spring with the free end locking portion, allowing the operator to freely switch the torque during rotation regardless of the rotation angle, etc. Multiple lock springs are provided (multiple lock springs are arranged at predetermined intervals along the longitudinal direction of the shaft member), and a free end locking portion is provided for each lock spring. This allows the number of lock springs whose free ends are locked with the free end locking portion to be adjusted in multiple stages, and also allows the torque during rotation to be adjusted in multiple stages. Furthermore, the hinge mechanism of the present invention, which uses lock springs, does not require the precision required for the hinge mechanism of Patent Document 2. Additionally, the hinge mechanism of the present invention allows the number of parts to be reduced, thereby reducing the manufacturing cost of the hinge mechanism.

[0016] In the hinge mechanism of the present invention, the terms "fixed" in relation to the fixed member and "rotating" in relation to the rotating member are used for convenience only, and the fixed member and the rotating member may rotate in any manner as long as they rotate relative to each other. In other words, the technical scope of the hinge mechanism of the present invention includes all manners in which the rotating member rotates relative to a stationary fixed member, in which the fixed member rotates relative to a stationary rotating member, and in which the rotating member rotates relative to a rotating fixed member.

[0017] However, in this case, if adjacent lock springs come into contact (interfere) with each other, the operation of the lock springs may become unstable, and the hinge mechanism may not be able to perform the desired operation. For this reason, if the hinge mechanism of the present invention is equipped with multiple lock springs, it is preferable to provide a partition between adjacent lock springs. This prevents adjacent lock springs from interfering with each other.

[0018] Furthermore, when the hinge mechanism of the present invention includes multiple lock springs, it is preferable that some of the multiple lock springs be right-handed springs and the rest be left-handed springs. This makes it possible to reverse the high torque direction (low torque direction) itself. For example, if an even number of lock springs are used, with half of them being right-handed springs and the other half being left-handed springs, it becomes possible to reverse the high torque direction (low torque direction) by setting all right-handed springs in a locked state and all left-handed springs in an unlocked state, or by setting all right-handed springs in an unlocked state and all left-handed springs in a locked state.

[0019] Furthermore, when the hinge mechanism of the present invention includes multiple locking springs, it is also preferable to provide a free-end connecting member that integrally connects the free ends of the multiple locking springs and a connecting member moving mechanism that moves the free-end connecting member relative to the retaining member. This allows the free ends of the multiple locking springs to be moved simultaneously, making it easier to operate the hinge mechanism. It also allows the free ends of the locking springs to be held at an intermediate position between the locked and unlocked positions, allowing for more precise torque adjustment. In addition, it also allows the free ends of the locking springs to be held at a position displaced toward the tightening side from the locked position, further increasing the torque (slip torque) when rotating the hinge mechanism. [Effects of the Invention]

[0020] As described above, the present invention makes it possible to provide a hinge mechanism that allows the torque to be varied depending on the rotation direction and that allows the operator to freely switch the torque during rotation.Furthermore, it is also possible to provide such a hinge mechanism with a simple and low-cost structure. [Brief explanation of the drawings]

[0021] [Figure 1] FIG. 2 is a perspective view showing the spring lock hinge mechanism of the first embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the spring lock hinge mechanism of the first embodiment. [Figure 3] FIG. 1 is a plan view showing a spring lock hinge according to a first embodiment. [Figure 4] 4A and 4B are cross-sectional views of the spring lock hinge mechanism of the first embodiment taken along line X1-X1 in FIG. 3, showing (a) a state in which the free end of the lock spring is in a locked position, and (b) a state in which the free end of the lock spring is in an unlocked position. [Figure 5]10A and 10B are plan views of a spring lock hinge mechanism of a second embodiment, each showing (a) a state in which the free ends of all lock springs are in the locked position, (b) a state in which the free ends of two lock springs are in the unlocked position, and (c) a state in which the free ends of four lock springs are in the unlocked position. [Figure 6] FIG. 10 is a plan view showing the inside of a spring lock hinge mechanism according to a third embodiment. [Figure 7] FIG. 10 is a plan view showing a spring lock hinge mechanism according to a fourth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0022] The spring lock hinge mechanism of the present invention will be specifically described with reference to the drawings. Below, the hinge mechanism of the present invention will be described using four embodiments (first to fourth embodiments) as examples. However, these embodiments are merely preferred embodiments, and the technical scope of the hinge mechanism of the present invention is not limited to these embodiments. The hinge mechanism of the present invention can be modified as appropriate within the scope of the invention.

[0023] 1. First embodiment of spring lock hinge mechanism First, a spring lock hinge mechanism of a first embodiment will be described. FIG. 1 is a perspective view showing the spring lock hinge mechanism of the first embodiment. FIG. 2 is a perspective view showing the spring lock hinge mechanism of the first embodiment in an exploded state. FIG. 3 is a plan view showing the spring lock hinge of the first embodiment. FIG. 4 is a cross-sectional view of the spring lock hinge mechanism of the first embodiment taken along line X1-X1 in FIG. 3. FIG. 4(a) shows a state in which the free end 22 of the lock spring 20 is in a locked position, and FIG. 4(b) shows a state in which the free end 22 of the lock spring 20 is in an unlocked position.

[0024] 2, the hinge mechanism of the first embodiment includes an axis member 10, a lock spring 20, a fixed member 30, a rotating member 40, and a holding member 50, and connects the rotating member 40 to the fixed member 30 in a state where the rotating member 40 can rotate relatively to the fixed member 30. As already mentioned, in the hinge mechanism of the present invention, the manner in which the fixed member 30 and the rotating member 40 rotate is not limited, but for the sake of convenience, the following description will be given taking as an example a case in which the rotating member 40 rotates relative to the immovable fixed member 30.

[0025] The shaft member 10 is a cylindrical or columnar member that defines the rotation center of the hinge mechanism. The rotation member 40 rotates relative to the fixed member 30 around the shaft member 10.

[0026] The lock spring 20 is a coil spring with an inner diameter that is several percent (for example, about 2 to 5%) smaller than the outer diameter of the shaft member 10. This lock spring 20 is wound (fitted) around the outer periphery of the shaft member 10 in a state in which it is elastically expanded in diameter. Although only one lock spring 20 may be fitted around the shaft member 10, in the hinge mechanism of the first embodiment, four lock springs 20 are fitted around the shaft member 10 at predetermined intervals in the longitudinal direction.

[0027] The fixing member 30 is fixed so as not to move relative to the shaft member 10. In the hinge mechanism of the first embodiment, the fixing member 30 has a configuration in which a pair of left and right side plate portions 31, 31 are connected by a band-shaped portion 32. Each of the side plate portions 31, 31 is provided with a through hole for passing the shaft member 10 therethrough, and is fixed to the shaft member 10 at the through hole. The fixing member 30 and the shaft member 10 are integrated by caulking, but other joining methods such as welding or bolting may also be used. The band-shaped portion 32 is provided with a bolt hole for passing a bolt 60 therethrough.

[0028] The rotating member 40 is attached in a state where it can rotate relatively to the shaft member 10. In the hinge mechanism of the first embodiment, the rotating member 40 has a configuration in which a pair of left and right side plate portions 41, 41 are connected by a band-shaped portion 42. Each of the side plate portions 41, 41 is provided with a through hole for passing the shaft member 10 therethrough, and is pivotally supported by the shaft member 10 at the through hole portion. The band-shaped portion 42 is provided with a bolt hole for passing a bolt 60 therethrough.

[0029] The holding member 50 has a fixed end holding portion 51 for holding one end (fixed end 21) of the lock spring 20. The holding member 50 also has a free end locking portion 52 that can lock the free end 22 of the lock spring 20 in a state where it is displaced toward the loosened side. In the hinge mechanism of the first embodiment, the rotating member 40 is formed in a cylindrical shape so that it can encase the shaft member 10 and the lock spring 20. The holding member 50 has a structure that can be separated into two semi-cylindrical members (an upper holding member 50a and a lower holding member 50b). Plate-shaped protrusions 53, 53 are provided on the upper holding member 50a and the lower holding member 50b, respectively. A bolt hole for passing a bolt 60 is provided on each of the protrusions 53, 53. By passing the bolt 60 through the bolt holes of the protrusions 53, 53 of the retaining member 50 and the bolt hole of the strip portion 42 of the rotating member 40, the upper retaining member 50a and the lower retaining member 50b are integrated, and the retaining member 50 is integrated with the rotating member 40.

[0030] The fixed end holding portion 51 is provided in a groove shape at the boundary between the upper holding member 50a and the lower holding member 50b. Because there are four lock springs 20, the fixed end holding portion 51 needs to be provided in four locations, but in the hinge mechanism of the first embodiment, it is provided in eight locations. This is to accommodate cases where the positional relationship between the fixed end 21 and free end 22 of each lock spring 20 is reversed.

[0031] As shown in FIG. 3, the free end locking portion 52 is provided at one end of a free end passage 54, which is an elongated hole formed along the circumferential direction of the cylinder. Because there are four lock springs 20, the free end passages 54 and free end locking portions 52 need only be provided at four locations. However, in the hinge mechanism of the first embodiment, as shown in FIG. 4, the free end passages 54 and free end locking portions 52 are provided at four locations on the upper holding member 50a, as well as at four locations on the lower holding member 50b. The free end passages 54 and free end locking portions 52 of the upper holding member 50a and the free end passages 54 and free end locking portions 52 of the lower holding member 50b are arranged symmetrically from top to bottom. This is to accommodate both right-handed and left-handed winding locking springs, which can be used as lock springs 20.

[0032] As shown in FIG. 4(a), when the lock spring 20 in this hinge mechanism has its free end 22 in the locked position (approximately the middle position of the free end passage 54), the lock spring 20 is in a locked state in which it tightens the shaft member 10. Even in this locked state, if counterclockwise torque (torque in a direction that causes the rotating member 40 to rotate counterclockwise about the center line L1 in FIG. 4(a)) is applied to the rotating member 40, the retaining member 50, which rotates together with the rotating member 40, also displaces the fixed end 21 of the lock spring 20 in the counterclockwise direction (in the direction that pushes the fixed end 21 in), causing the diameter of the lock spring 20 to expand slightly and the lock spring 20 to become loose relative to the shaft member 10. Therefore, even if the torque is relatively small, the lock spring 20 slips relative to the shaft member 10, and the rotating member 40 rotates in that direction. Thus, among the rotation directions of the rotating member 40, the direction in which the lock spring 20 is loosened is called the “loosening direction.” The torque required to rotate the rotating member 40 at this time (a value assuming there is only one lock spring 20; the same applies below) is defined as T1.

[0033] In contrast, if clockwise torque (torque in a direction that rotates the rotating member 40 clockwise around the center line L1 in FIG. 4(a)) is applied to the rotating member 40 when the lock spring 20 is in the locked state, the retaining member 50, which rotates together with the rotating member 40, also displaces the fixed end 21 of the lock spring 20 in the clockwise direction (in a direction that pulls the fixed end 21). As a result, the diameter of the lock spring 20 contracts, and the lock spring 20 tightly tightens the shaft member 10. Therefore, application of torque T1 alone does not cause the lock spring 20 to slip relative to the shaft member 10, and the rotating member 40 cannot be rotated. Only when torque T2 (a value assuming there is only one lock spring 20; the same applies below) exceeding torque T1 is applied does the lock spring 20 slip relative to the shaft member 10, and the rotating member 40 rotates in that direction. In this way, among the rotation directions of the rotating member 40, the direction in which the lock spring 20 tightens the shaft member 10 is called the "tightening direction."

[0034] In this way, when the lock spring 20 is in the locked state, the torque T2 when rotating the rotating member 40 in the tightening direction is greater than the torque T1 when rotating the rotating member 40 in the loosening direction. In other words, the force required to rotate the rotating member 40 in the tightening direction is heavier (the resistance force is greater) than the force required to rotate the rotating member 40 in the loosening direction.

[0035] 4(b), when the free end 22 of the lock spring 20 is displaced in the direction of arrow A1 and engaged with the free end engaging portion 52 (held in the unlocked position), the diameter of the lock spring 20 expands and the lock spring 20 is loosened (unlocked) relative to the shaft member 10. Therefore, the rotating member 40 can rotate approximately freely in both the tightening and loosening directions simply by applying a torque T3 that is significantly smaller than the torque T1 described above.

[0036] In this regard, the hinge mechanism of the first embodiment is provided with four lock springs 20, and the free ends 22 of each lock spring 20 can be operated separately (the free ends 22 can be individually selected to be in the locked position or the unlocked position).

[0037] For this reason, as shown in Figure 3, when the free ends 22 of all four lock springs 20 are in the locked position (all four lock springs 20 are in the locked state), a torque of 4 x T1 must be applied to rotate them in the loosening direction, and a torque of 4 x T2 must be applied to rotate them in the tightening direction. In contrast, when three lock springs 20 are in the locked state but the free end 22 of one lock spring 20 is in the unlocked position (one lock spring 20 is in the unlocked state), a torque of 3 x T1 must be applied to rotate them in the loosening direction, and a torque of 3 x T2 must be applied to rotate them in the tightening direction. By further increasing the number of lock springs 20 in the unlocked state, the above torque can be gradually reduced.

[0038] Incidentally, when multiple lock springs 20 are used, as in the hinge mechanism of the first embodiment, if adjacent lock springs 20 come into contact (interfere) with each other, the operation of the lock springs 20 may become unstable. For this reason, in the hinge mechanism of the first embodiment, as shown in FIG. 2, an inner flange-shaped partition 55 is provided on the inner periphery of the holding member 50. This partition 55 is provided not only on the lower holding member 50b but also on the upper holding member 50a, approximately symmetrically in the vertical direction. This prevents adjacent lock springs 20 from interfering with each other, thereby stabilizing the operation of the lock springs 20.

[0039] 2. Second embodiment of spring lock hinge mechanism Next, a spring lock hinge mechanism of a second embodiment will be described. The hinge mechanism of the second embodiment will be described focusing on the configuration that is different from the hinge mechanism of the first embodiment. Configurations of the hinge mechanism of the second embodiment that are not specifically mentioned can be substantially the same as those described for the hinge mechanism of the first embodiment.

[0040] Figure 5 is a plan view of a spring lock hinge mechanism of the second embodiment. While the hinge mechanism of the first embodiment (Figure 2) uses four lock springs 20, the hinge mechanism of the second embodiment uses five lock springs 20, as shown in Figure 5. Therefore, free end passages 54 and free end engaging portions 52 are also provided in five locations on the upper holding member 50a. This makes it possible to adjust the torque when rotating the hinge mechanism in multiple stages over a wider range.

[0041] For example, in FIG. 5( a), all five lock springs 20 are in the locked state. In this state, the hinge mechanism is in a "maximum torque" state in which the rotational torque is large. In FIG. 5( b), three of the five lock springs 20 are in the locked state, and the remaining two lock springs 20 are in the unlocked state. In this state, the hinge mechanism is in a "medium torque" state in which the rotational torque is medium. In FIG. 5( c), only one of the five lock springs 20 is in the locked state, and the remaining four lock springs 20 are in the unlocked state. In this state, the hinge mechanism is in a "low torque" state in which the rotational torque is small. In addition to this, the hinge mechanism can also be in a "high torque" state in which four lock springs 20 are in the locked state and one lock spring 20 is in the unlocked state, or a "minimum torque" state (free state) in which all five lock springs 20 are in the unlocked state.

[0042] In this way, by increasing the number of lock springs 20, the torque when rotating the hinge mechanism can be adjusted in multiple stages over a wider range. When multiple lock springs 20 are used, the number of lock springs 20 is typically in the range of 3 to 30, and preferably in the range of 4 to 10. Here, if only the torque when the lock spring 20 is in the locked state (lock torque) is to be increased, this can be achieved by increasing the wire diameter of the lock spring 20 or the number of windings. However, in this case, the outer diameter of the lock spring 20 increases, which increases the dimension around the axis of the hinge mechanism (the radial dimension about the center line L1). In addition, the increased lock torque may be concentrated on the fixed end 21 of the lock spring 20, which may cause damage to the lock spring 20 near the fixed end 21. In this regard, by increasing the number of lock springs 20, it is possible to increase the lock torque while suppressing an increase in the dimension around the shaft diameter of the hinge mechanism and damage to the lock springs 20.

[0043] 3. Third embodiment of spring lock hinge mechanism Next, a spring lock hinge mechanism of a third embodiment will be described. The hinge mechanism of the third embodiment will be described focusing on the configuration that is different from the hinge mechanism of the first embodiment. Configurations of the hinge mechanism of the third embodiment that are not specifically mentioned can be substantially the same as those described for the hinge mechanisms of the first and second embodiments.

[0044] Figure 6 is a plan view showing the interior of a spring lock hinge mechanism of a third embodiment. In the hinge mechanism of the first embodiment (Figure 2), all of the multiple lock springs 20 were of the same type (left-handed springs), but in the hinge mechanism of the third embodiment, as shown in Figure 6, the lock springs 20 are a mixture of left-handed springs 20a and right-handed springs 20b. Specifically, of the four lock springs 20 shown in Figure 6, two lock springs 20 on both the left and right sides are right-handed springs 20b, and two lock springs 20 on the inside (center) are left-handed springs 20a.

[0045] The free end 22 of the left-handed spring 20a passes through the free end passage 54 and free end locking portion 52 on the upper holding member 50a, and the free end 22 of the right-handed spring 20b passes through the free end passage 54 and free end locking portion 52 on the lower holding member 50b (see FIG. 2). The free end passage 54 and free end locking portion 52 on the upper holding member 50a and the free end passage 54 and free end locking portion 52 on the lower holding member 50b are formed symmetrically from top to bottom, so that either the left-handed spring 20a or the right-handed spring 20b can be used. Note that, to accommodate both the left-handed spring 20a and the right-handed spring 20b, it is not necessary to make the free end passage 54 and free end locking portion 52 on the upper holding member 50a and the lower holding member 50b symmetrical from top to bottom. For example, even if the free end passage 54 and the free end locking portion 52 have the same shape in the upper holding member 50a and the lower holding member 50b, they can be used with both the left-handed coil spring 20a and the right-handed coil spring 20b.

[0046] In this way, by mixing the left-handed spring 20a and the right-handed spring 20b as the lock spring 20, it is possible not only to adjust the magnitude of the torque when rotating the hinge mechanism but also to reverse the high-torque direction (the direction in which the torque when rotating becomes large). For example, as shown in Fig. 6(a), when the right-handed spring 20b is in the locked state and the left-handed spring 20a is in the unlocked state, the tightening direction of the right-handed spring 20b (the loosening direction of the left-handed spring 20a) is the high-torque direction, whereas as shown in Fig. 6(b), when the right-handed spring 20b is in the unlocked state and the left-handed spring 20a is in the locked state, the loosening direction of the right-handed spring 20b (the tightening direction of the left-handed spring 20a) is the high-torque direction.

[0047] 4. Spring-locked hinge mechanism of the fourth embodiment Finally, a spring-locked hinge mechanism according to a fourth embodiment will be described. The hinge mechanism according to the fourth embodiment will be described focusing on the configurations that are different from the hinge mechanism according to the first embodiment. Configurations of the hinge mechanism according to the fourth embodiment that are not specifically mentioned can be substantially the same as those described for the hinge mechanisms according to the first, second, and third embodiments.

[0048] 7 is a plan view showing a spring lock hinge mechanism of the fourth embodiment. As shown in FIG. 7, the hinge mechanism of the fourth embodiment includes a free end connecting member 70 and a connecting member moving mechanism 80. The free end connecting member 70 is a plate-shaped member that integrally connects the free ends 22 of multiple lock springs 20. The connecting member moving mechanism 80 moves the free end connecting member 70 relative to the holding member 50.

[0049] The mechanism of the connecting member moving mechanism 80 is not particularly limited, but in the hinge mechanism of the fourth embodiment, the bolt threadedly engaged with the free-end connecting member 70 functions as the connecting member moving mechanism 80. When the bolt 80 is rotated to one side, the free-end connecting member 70 moves in the direction of arrow A2 in Figure 7, and the free ends 22 of each lock spring 20 move in the tightening direction. On the other hand, when the bolt 80 is rotated to the other side, the free-end connecting member 70 moves in the direction opposite to arrow A2, and the free ends 22 of each lock spring 20 move in the loosening direction.

[0050] In this way, by providing the free end connecting member 70 and connecting member moving mechanism 80, it is possible to simultaneously move the free ends of multiple lock springs 20, facilitating operation of the hinge mechanism. It is also possible to hold the free ends 22 of the lock springs 20 at an intermediate position between the locked and unlocked positions, enabling more precise torque adjustment. Additionally, it is also possible to hold the free ends 22 of the lock springs 20 at a position displaced further toward the tightening side than the locked position shown in FIG. 7, further increasing the torque (slip torque) when rotating the hinge mechanism.

[0051] 5.Applications The hinge mechanism of the present invention is not particularly limited in its application and can be used in a variety of applications. However, because the hinge mechanism of the present invention has the characteristics described above, it can be suitably employed in applications where it is necessary to provide a difference in torque depending on the rotation direction, or where the operator needs to adjust the torque during rotation. Examples of such applications include furniture such as angle-adjustable beds and chairs. [Explanation of symbols]

[0052] 10 Shaft member 20 Lock spring 20a left-handed spring 20b Right-handed spring 21 Fixed end 22 Free end 30 Fixing member 31 Side plate part 32 Belt 40 Rotating member 41 Side plate part 42 Belt 50 holding member 50a Upper holding member 50b Lower holding member 51 Fixed end holding part 52 Free end locking part 53 Projection piece 54 Free end passage 55 Partition 60 volts 70 Free end connecting member 80 Connecting member movement mechanism

Claims

1. A shaft member; a plurality of lock springs each made of a coil spring having an inner diameter smaller than the outer diameter of the shaft member, the lock springs being wound around the outer periphery of the shaft member in an elastically expanded state; a fixed member that is fixed so as not to move relative to the shaft member; a rotating member attached to the shaft member in a state that allows it to rotate relatively; a holding member having a fixed end holding portion for holding the fixed end of the lock spring and fixed in a state where it does not move relative to the rotating member; Equipped with When torque is applied to the rotating member in a direction in which the lock spring winds up (hereinafter referred to as the "tightening direction"), if the torque is below a specified value, the rotating member will not rotate in the tightening direction, but if the torque exceeds the specified value, the lock spring will slip relative to the shaft member, causing the rotating member to rotate in the tightening direction. When torque is applied to the rotating member in the direction opposite to the tightening direction (hereinafter referred to as the "loosening direction"), the lock spring slips relative to the shaft member, causing the rotating member to rotate in the loosening direction. The holding member is provided with a free end locking portion that can forcibly displace the free ends of the lock springs toward the loosened side for each lock spring to lock them, By switching between a locked state in which the free end is not locked to the free end locking part and an unlocked state in which the free end is locked to the free end locking part, it is possible to adjust the torque when rotating the rotating member relative to the fixed member. A spring-locked hinge mechanism characterized by:

2. A partition is provided between adjacent lock springs.

2. The spring lock hinge mechanism of claim 1.

3. 2. The spring lock hinge mechanism according to claim 1, wherein some of the plurality of lock springs are right-handed springs and the rest are left-handed springs.

4. a free end connecting member that integrally connects the free ends of the plurality of lock springs; a connecting member moving mechanism that moves the free end connecting member relative to the holding member; 2. The locking hinge mechanism of claim 1, comprising:

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