Torsion coil spring and its manufacturing method, fastener for jewelry, assembly set for fastener for jewelry and jewelry

Abstract

To provide a torsion coil spring that can handle larger loads even when miniaturized. [Solution] The arm portion (13A, 13B) has a first bent portion (141A, 141B) when viewed from a first direction D1 parallel to the center line L1, and a second bent portion (142A, 142B) when viewed from a reference direction (D2A, D2B) perpendicular to the center line L1. When viewed from the first direction D1, the second portion (132A, 132B) from the first bent portion (141A, 141B) to the tip (135A, 135B) bends to the opposite side of the tangent line (L2A, L2B) from the side where the hole 121 is located. When viewed from the reference direction (D2A, D2B), the fourth section (134A, 134B), from the second bend (142A, 142B) to the tip (135A, 135B), bends toward the side where the coil section 12 is located relative to the perpendicular line (L3A, L3B).

Description

[Technical Field]

[0001] The present invention relates to a torsion coil spring, a method for manufacturing the same, a fastener for an accessory, an assembly kit for an accessory fastener, and an accessory. [Background Art]

[0002] Various types of fasteners (also called clasps) used for connecting chains in accessories such as necklaces are known, including pull-ring type, plug-in type, screw type and the like. There is also a known fastener provided with a rotary structure that realizes an open state and a closed state by two rotatably connected members (see, for example, Patent Document 1). [Prior Art Document] [Patent Document]

[0003] [Patent Document 1] Japanese Unexamined Patent Publication No. 09-299117 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the case of a fastener having a rotary structure, a torsion coil spring is sometimes used as an urging means for maintaining the closed state. However, when the torsion coil spring is miniaturized for application to a fastener, for example, it may be difficult to obtain a target elastic force. Further, for example, when the torsion coil spring is enlarged to obtain a target elastic force, it may be difficult to accommodate the spring in the fastener.

[0005] The present invention has been made in view of such circumstances, and an object of the present invention is to provide a torsion coil spring that can apply a larger load even when miniaturized, a method for manufacturing the same, and a fastener for an accessory, an assembly kit for an accessory fastener, and an accessory using such a torsion coil spring. [Means for Solving the Problem]

[0006] A first aspect of the present invention comprises a coil portion in which a wire is wound in a spiral shape, and two arm portions extending toward the tip from both ends of the coil portion, wherein the central hole of the coil portion is circular when viewed from a first direction parallel to the center line of the spiral shape, the two arm portions are defined by different reference directions perpendicular to the center line, different tangents of the circular shape, and different perpendiculars perpendicular to the center line when viewed from the reference directions, each end of the coil portion is in contact with the tangent defining one of the arm portions extending from each end, is located behind the center line when viewed from the reference direction defining the one arm portion, and is in contact with the perpendicular defining the one arm portion at its edge in the first direction when viewed from the reference direction defining the one arm portion, and each arm portion when viewed from the first direction has a first bend The torsion coil spring is such that each arm portion has a first portion from one of the ends extending from it to the first bent portion, which extends in a direction along the tangent line defining each arm portion, and the second portion from the first bent portion to the tip forms an obtuse angle with respect to the tangent line defining each arm portion, and the second portion is bent on the opposite side of the side where the hole is located relative to the tangent line defining each arm portion, and each arm portion viewed from the reference direction has a second bent portion, and the third portion from one of the ends extending from it to the second bent portion extends in a direction along the perpendicular line defining each arm portion, and the fourth portion from the second bent portion to the tip forms an obtuse angle with respect to the third portion, and the fourth portion is bent on the side where the coil portion is located relative to the perpendicular line defining each arm portion.

[0007] A second aspect of the present invention comprises the steps of forming a coil by winding a wire in a spiral shape, and forming two arm portions extending from both ends of the coil portion toward the tip, wherein the central hole of the coil portion is circular when viewed from a first direction parallel to the center line of the spiral shape, the two arm portions are defined by different reference directions perpendicular to the center line, different tangents to the circular shape, and different perpendiculars perpendicular to the center line when viewed from the reference directions, and each end of the coil portion is defined by one of the portions extending from each end. The process of forming each arm portion involves extending the wire extending from one of the ends corresponding to each arm portion in a direction along the tangent that defines each arm portion, as viewed from the first direction, and extending the wire extending from one of the ends corresponding to each arm portion in a direction along the tangent that defines each arm portion, as viewed from the first direction, and as viewed from the reference direction that defines each arm portion, The process includes a first step of extending the wire in a direction along the perpendicular line defining the arm, a second step of bending the wire extending from one end at a first bend after the first step, and a third step of bending the wire extending from one end at a second bend after the first step, wherein the second step makes the angle between the first portion from the one end to the first bend and the second portion from the first bend to the tip obtuse when viewed from the first direction, and the second portion when viewed from the first direction, A method for manufacturing a torsion coil spring, comprising bending each arm portion toward the opposite side of the side on which the hole is located with respect to the tangent line defining each arm portion, the third step comprising making the angle between the third portion from one end to the second bent portion and the fourth portion from the second bent portion to the tip obtuse when viewed from the reference direction defining each arm portion, and bending the fourth portion when viewed from the reference direction defining each arm portion toward the side on which the coil portion is located with respect to the perpendicular line defining each arm portion.

[0008] A third aspect of the present invention is a fastener for jewelry comprising a first member, a second member rotatably connected to the first member, and a torsion coil spring of the first aspect that provides a biasing force for rotating the first member and the second member.

[0009] A fourth aspect of the present invention is an assembly set for a fastener for jewelry, comprising a first member, a second member rotatably connected to the first member, and a torsion coil spring of the first aspect that provides a biasing force for rotating the first member and the second member.

[0010] A fifth aspect of the present invention is an accessory comprising the accessory fastener of the third aspect described above. [Effects of the Invention]

[0011] According to the present invention, it is possible to provide a torsion coil spring that can withstand a larger load even when miniaturized, and a method for manufacturing the same, as well as a fastener for jewelry using such a torsion coil spring, an assembly set for the fastener for jewelry, and jewelry. [Brief explanation of the drawing]

[0012] [Figure 1] Figures 1A to 1C show an example of a torsion coil spring according to this embodiment. [Figure 2] Figure 2A is a diagram illustrating the torsional force acting on the wire in the arm portion of the torsion coil spring shown in Figures 1A to 1C. Figure 2B is a diagram illustrating a comparative example corresponding to Figure 2A. [Figure 3] Figures 3A to 3C show another example of a torsion coil spring according to this embodiment. [Figure 4] Figures 4A and 4B show an example of a fastener using a torsion coil spring according to this embodiment. [Figure 5] Figure 5A is a side view of the fastener, and Figure 5B is a cross-sectional view showing the internal structure of the fastener. [Figure 6]Figure 6A is a flowchart illustrating an example of a method for manufacturing a torsion coil spring according to this embodiment. Figure 6B is a flowchart illustrating an example of a procedure for forming the arm portion. [Modes for carrying out the invention]

[0013] Conventional torsion coil springs consist of a coil section and an arm section without a bend. In such conventional torsion coil springs, when a load is applied to the point of application and the fixed point, a certain amount of deflection (so-called "play") occurs before the applied load acts on the torsion coil spring. For this reason, conventional torsion coil springs have a low load capacity. In particular, when reducing the number of turns of a torsion coil spring to house it inside devices where miniaturization is required, the spring power of the torsion coil spring decreases, resulting in a lower load capacity.

[0014] In contrast, the torsion coil spring according to this embodiment has a bent portion in each arm, and the portion from the coil portion to the bent portion and the portion from the bent portion to the tip of the arm form an obtuse angle. Furthermore, the torsion coil spring according to this embodiment has a structure in which the portion from the bent portion to the tip of the arm in each arm is inclined toward the opposite side of the coil portion when viewed from a side view from a direction parallel to the center line of the spiral shape of the coil portion (first direction), and also has a structure in which the portion is inclined toward the coil portion when viewed from a side view from a direction perpendicular to the center line and from the direction in which the beginning or end of the winding of the coil portion is viewed (reference direction).

[0015] In the case where only the first bending structure that inclines the arm portion toward the side opposite to the coil portion in a side view from the first direction is provided, although "play" of the arm portion can be reduced, it may be necessary to reduce the number of windings, for example, to downsize the torsion coil spring. On the other hand, in the case where only the second bending structure that inclines the arm portion toward the coil portion side in a side view from the reference direction is provided, "play" cannot be reduced, and it is difficult to apply a larger load. Therefore, in the torsion coil spring according to the present embodiment, since each arm portion has the first bending structure and the second bending structure, a larger load can be applied even when the torsion coil spring is downsized, compared to a conventional torsion coil spring in which each arm portion has no bent portion.

[0016] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIGS. 1A to 1C are diagrams showing an example of the torsion coil spring according to the present embodiment. The torsion coil spring 1 shown in FIGS. 1A to 1C includes a coil portion 12 formed by spirally winding a wire 10, and two arm portions (13A, 13B) respectively extending from ends (122A, 122B) on both sides of the coil portion 12 toward tips (135A, 135B). The arm portion 13A extends from one end 122A of the coil portion 12 toward the tip 135A, and the arm portion 13B extends from the other end 122B of the coil portion 12 toward the tip 135B.

[0017] “D1” in FIGS. 1A and 1C indicates a direction parallel to the spiral center line L1 of the coil portion 12 (hereinafter referred to as "first direction D1"). Further, "D2A" and "D2B" in FIG. 1B respectively indicate directions perpendicular to the center line L1 (hereinafter respectively referred to as "reference direction D2A" and "reference direction D2B").

[0018] FIG. 1A is a view of the torsion coil spring 1 seen from a direction parallel to the reference direction D2A. FIG. 1B is a view of the torsion coil spring 1 seen from a direction parallel to the first direction D1 (a direction parallel to the center line L1). FIG. 1C is a view of the torsion coil spring 1 seen from a direction parallel to the reference direction D2B.

[0019] In the examples of FIGS. 1A and 1C, the coil portion 12 is formed by winding the wire rod 10 three times in a spiral shape, and then winding an additional 105° in the same direction. The coil portion 12 is also formed by so-called close winding, in which the wire rod 10 is wound with the individual rod portions substantially in close contact with each other. As shown in FIG. 1B, a central hole 121 of the coil portion 12 as viewed from the first direction D1 is substantially circular. A center line L1 passes through the center of this circular shape.

[0020] "L2A" and "L2B" in FIG. 1B indicate tangents to the circular shape of the hole 121 as viewed from the first direction D1 (hereinafter referred to as "tangent L2A" and "tangent L2B", respectively).

[0021] "L3A" in FIG. 1A indicates a perpendicular line perpendicular to the center line L1 as viewed from the reference direction D2A (hereinafter referred to as "perpendicular line L3A"). "L3B" in FIG. 1C indicates a perpendicular line perpendicular to the center line L1 as viewed from the reference direction D2B (hereinafter referred to as "perpendicular line L3B").

[0022] In the torsion coil spring 1 according to the present embodiment, the arm portion 13A and the arm portion 13B are respectively defined by different reference directions (D2A, D2B), different tangents (L2A, L2B), and different perpendicular lines (L3A, L3B). That is, the arm portion 13A is defined by the reference direction D2A, the tangent L2A, and the perpendicular line L3A, and the arm portion 13B is defined by the reference direction D2B, the tangent L2B, and the perpendicular line L3B.

[0023] As shown in FIG. 1B, the end portion 122A of the coil portion 12 is in contact with the tangent L2A that defines the arm portion 13A extending from the end portion 122A. Also, as shown in FIG. 1A, the end portion 122A is located behind the center line L1 when viewed from the reference direction D2A that defines the arm portion 13A. Furthermore, as shown in FIG. 1A, the end portion 122A is in contact with the perpendicular line L3A that defines the arm portion 13A at an end edge in the first direction D1 (the lower end edge in FIG. 1A) when viewed from the reference direction D2A that defines the arm portion 13A.

[0024] As shown in Figure 1B, the end 122B of the coil portion 12 is in contact with the tangent line L2B that defines the arm portion 13B extending from this end 122B. Also, as shown in Figure 1C, the end 122B is located behind the center line L1 when viewed from the reference direction D2B that defines the arm portion 13B. Furthermore, as shown in Figure 1C, the end 122B is in contact with the perpendicular line L3B that defines the arm portion 13B when viewed from the reference direction D2B that defines the arm portion 13B, at the edge of the first direction D1 (the right edge in Figure 1C).

[0025] (Arm sections 13A and 13B as viewed from the first direction D1) As viewed from the first direction D1, the arm portion 13A has a first bent portion 141A, as shown in Figure 1B. In the arm portion 13A as viewed from the first direction D1, the first portion 131A from the end 122A extending from the arm portion 13A to the first bent portion 141A extends in a direction along the tangent L2A defining the arm portion 13A, as shown in Figure 1B. Also, in the arm portion 13A as viewed from the first direction D1, the second portion 132A from the first bent portion 141A to the tip 135A and the first portion 131A form an obtuse angle, as shown in Figure 1B. Furthermore, in the arm portion 13A as viewed from the first direction D1, the second portion 132A is bent toward the opposite side (lower side in Figure 1B) from the tangent L2A defining the arm portion 13A, where the hole 121 of the coil portion 12 is located.

[0026] As shown in Figure 1B, in the arm portion 13A viewed from the first direction D1, the length of the first portion 131A from the end portion 122A to the first bent portion 141A is shorter than the length of the second portion 132A from the first bent portion 141A to the tip portion 135A. In other words, in the arm portion 13A viewed from the first direction D1, the position of the first bent portion 141A is closer to the end portion 122A than to the tip portion 135A.

[0027] As viewed from the first direction D1, the arm portion 13B has a first bent portion 141B, as shown in Figure 1B. In the arm portion 13B as viewed from the first direction D1, the first portion 131B from the end portion 122B extending from the arm portion 13B to the first bent portion 141B extends in a direction along the tangent L2B that defines the arm portion 13B, as shown in Figure 1B. Also, in the arm portion 13B as viewed from the first direction D1, the second portion 132B from the first bent portion 141B to the tip 135B and the first portion 131B form an obtuse angle, as shown in Figure 1B. Furthermore, in the arm portion 13B as viewed from the first direction D1, the second portion 132B is bent on the opposite side (left side in Figure 1B) from the tangent L2B that defines the arm portion 13B, to the side where the hole 121 of the coil portion 12 is located.

[0028] As shown in Figure 1B, in the arm portion 13B viewed from the first direction D1, the length of the first portion 131B from the end portion 122B to the first bent portion 141B is longer than the length of the second portion 132B from the first bent portion 141B to the tip portion 135B. In other words, in the arm portion 13B viewed from the first direction D1, the position of the first bent portion 141B is closer to the tip portion 135B than to the end portion 122B.

[0029] As shown in Figure 1B, the angle β1 between the extension direction of the second portion 132A and the tangent L2A, as viewed from the first direction D1, is approximately the same as the angle β2 between the extension direction of the second portion 132B and the tangent L2B, as viewed from the first direction D1. That is, the obtuse angle (180°-β1) between the first portion 131A and the second portion 132A of the arm portion 13A, as viewed from the first direction D1, is approximately equal to the obtuse angle (180°-β2) between the first portion 131B and the second portion 132B of the arm portion 13B, as viewed from the first direction D1. In the example in Figure 1B, angles β1 and β2 are approximately 20° (±5°). Also, in the example in Figure 1B, the angle α between the tangent L2A and the tangent L2B is approximately 75° (±5°).

[0030] (Arm sections 13A and 13B as viewed from reference directions D2A and D2B) As viewed from the reference direction D2A, the arm portion 13A has a second bent portion 142A, as shown in Figure 1A. In the arm portion 13A as viewed from the reference direction D2A, the third portion 133A, from the end portion 122A extending from the arm portion 13A to the second bent portion 142A, extends in a direction along the perpendicular L3A defining the arm portion 13A, as shown in Figure 1A. Furthermore, in the arm portion 13A as viewed from the reference direction D2A, the fourth portion 134A, from the second bent portion 142A to the tip 135A, and the third portion 133A form an obtuse angle, as shown in Figure 1A. Moreover, in the arm portion 13A as viewed from the reference direction D2A, the fourth portion 134A is bent toward the side where the coil portion 12 is located (upper side of Figure 1A) with respect to the perpendicular L3A defining the arm portion 13A.

[0031] As shown in Figure 1A, in the arm portion 13A viewed from the reference direction D2A, the length of the third portion 133A from the end portion 122A to the second bent portion 142A is shorter than the length of the fourth portion 134A from the second bent portion 142A to the tip portion 135A. In other words, in the arm portion 13A viewed from the reference direction D2A, the position of the second bent portion 142A is closer to the end portion 122A than to the tip portion 135A.

[0032] In Figure 1A, the dashed line "L4A" represents a virtual straight line (hereinafter referred to as "virtual straight line L4A") that defines the arm portion 13A. When viewed from the reference direction D2A that defines the arm portion 13A (Figure 1A), this virtual straight line L4A is parallel to the extension direction of the wire 10 of the coil portion 12, which is located in front of the center line L1, passes through the center in the width direction of the wire 10, and is the straight line closest to the end portion 122A to which the arm portion 13A extends. In the arm portion 13A as viewed from the reference direction D2A, the fourth portion 134A, from the second bent portion 142A to the tip 135A, is located between the perpendicular line L3A that defines the arm portion 13A and the virtual straight line L4A that defines the arm portion 13A, as shown in Figure 1A. As shown in Figure 1A, the virtual straight line L4A passes through the center P1 in the width direction of the wire 10 at a position half a turn from the end 122A of the coil portion 12.

[0033] As viewed from the reference direction D2B, the arm portion 13B has a second bent portion 142B, as shown in Figure 1C. In the arm portion 13B as viewed from the reference direction D2B, the third portion 133B, from the end portion 122B extending from the arm portion 13B to the second bent portion 142B, extends in a direction along the perpendicular L3B that defines the arm portion 13B, as shown in Figure 1C. Also, in the arm portion 13B as viewed from the reference direction D2B, the fourth portion 134B, from the second bent portion 142B to the tip 135B, and the third portion 133B form an obtuse angle, as shown in Figure 1C. Furthermore, in the arm portion 13B as viewed from the reference direction D2B, the fourth portion 134B is bent toward the side where the coil portion 12 is located (left side in Figure 1C) with respect to the perpendicular L3B that defines the arm portion 13B.

[0034] As shown in Figure 1C, in the arm portion 13B viewed from the reference direction D2B, the length of the third portion 133B from the end portion 122B to the second bent portion 142B is shorter than the length of the fourth portion 134B from the second bent portion 142B to the tip portion 135B. In other words, in the arm portion 13B viewed from the reference direction D2B, the position of the second bent portion 142B is closer to the end portion 122B than to the tip portion 135B.

[0035] In Figure 1C, the dashed line "L4B" represents a virtual straight line (hereinafter referred to as "virtual straight line L4B") that defines the arm portion 13B. When viewed from the reference direction D2B that defines the arm portion 13B (Figure 1C), this virtual straight line L4B is parallel to the extension direction of the wire 10 of the coil portion 12, which is located in front of the center line L1, passes through the center in the width direction of the wire 10, and is the straight line closest to the end portion 122B to which the arm portion 13B extends. In the arm portion 13B viewed from the reference direction D2B, the fourth portion 134B from the second bend 142B to the tip 135B is located between the perpendicular line L3B that defines the arm portion 13B and the first virtual straight line L4B that defines the arm portion 13B, as shown in Figure 1C. As shown in Figure 1C, the virtual straight line L4B passes through the center P2 in the width direction of the wire 10 at a position half a turn from the end 122B of the coil portion 12.

[0036] The angle θ1 (Figure 1A) between the extension direction of the fourth section 134A and the perpendicular L3A, as viewed from the reference direction D2A, is approximately the same as the angle θ2 (Figure 1C) between the extension direction of the fourth section 134B and the perpendicular L3B, as viewed from the reference direction D2B. That is, the obtuse angle (180°-θ1) between the third section 133A and the fourth section 134A of the arm section 13A (Figure 1A), as viewed from the reference direction D2A, is approximately equal to the obtuse angle (180°-θ2) between the third section 133B and the fourth section 134B of the arm section 13B (Figure 1C), as viewed from the reference direction D2B. In the examples in Figures 1A and 1C, angles θ1 and θ2 are approximately 10° (±5°).

[0037] (Bending positions of arm sections 13A and 13B) As shown in Figures 1A and 1B, in the arm portion 13A, the length of the first portion 131A as viewed from the first direction D1 is approximately equal to the length of the third portion 133A as viewed from the reference direction D2A. That is, the first bent portion 141A of the arm portion 13A as viewed from the first direction D1 and the second bent portion 142A of the arm portion 13A as viewed from the reference direction D2A are located at approximately the same position on the wire 10. As shown in Figures 1A and 1B, in the arm portion 13A, the wire 10 corresponding to the second portion 132A and the fourth portion 134A is longer than the wire 10 corresponding to the first portion 131A and the third portion 133A.

[0038] On the other hand, as shown in Figures 1B and 1C, in the arm portion 13B, the length of the third portion 133B as viewed from the reference direction D2B is shorter than the length of the first portion 131B as viewed from the first direction D1. That is, the second bent portion 142B of the arm portion 13B as viewed from the reference direction D2B is closer to the end portion 122B of the coil portion 12 (and further away from the tip portion 135B of the arm portion 13B) than the first bent portion 141B of the arm portion 13B as viewed from the first direction D1.

[0039] A torsion coil spring 1 having the above configuration has, for example, the following characteristics.

[0040] In the torsion coil spring 1 according to this embodiment, as shown in Figure 1B, the second portion 132A of the arm portion 13A, from the first bent portion 141A to the tip 135A as viewed from the first direction D1, is bent on the opposite side of the tangent L2A from the side where the hole 121 of the coil portion 12 is located. Also, as shown in Figure 1B, the second portion 132B of the arm portion 13B, from the first bent portion 141B to the tip 135B as viewed from the first direction D1, is bent on the opposite side of the tangent L2B from the side where the hole 121 of the coil portion 12 is located. Therefore, in the torsion coil spring 1, the elastic force acting between the arm portions 13A and 13B is greater than in the case where there is no such bending of the arm portions 13A and 13B. For example, when comparing the case where the distance between the tip 135A of arm portion 13A and the tip 135B of arm portion 13B as viewed from the first direction D1 is the same, the state in which the arms 13A and 13B as viewed from the first direction D1 have the aforementioned bend, compared to the state without the bend (the state in which angles β1 and β2 shown in Figure 1B are zero), the angle α (angle between tangents L2A and L2B) shown in Figure 1B becomes smaller. The smaller the angle α becomes, the greater the elastic force due to the tightening of the wire material 10 in the coil portion 12, and therefore the greater the elastic force acting between arm portions 13A and 13B. Thus, with the torsion coil spring 1 according to this embodiment, the elastic force is greater when comparing the case where the distance between the tips 135A and 135B as viewed from the first direction D1 is the same, so a larger load can be applied even when the size is reduced.

[0041] In the torsion coil spring 1 according to this embodiment, the arm portions 13A and 13B, as viewed from the first direction D1, are bent at obtuse angles. As a result, the range of motion of the arm portions 13A and 13B around the center line L1 is reduced as viewed from the first direction D1, making it easier to incorporate the torsion coil spring 1 into small devices (such as fasteners for jewelry).

[0042] In the torsion coil spring 1 according to this embodiment, as shown in Figure 1A, in the arm portion 13A viewed from the reference direction D2A, the fourth portion 134A from the second bent portion 142A to the tip 135A is bent toward the side where the coil portion 12 is located relative to the perpendicular L3A. Also, in the torsion coil spring 1 according to this embodiment, as shown in Figure 1C, in the arm portion 13B viewed from the reference direction D2B, the fourth portion 134B from the second bent portion 142B to the tip 135B is bent toward the side where the coil portion 12 is located relative to the perpendicular L3B. Therefore, in the torsion coil spring 1 according to this embodiment, the width of the torsion coil spring 1 viewed from a direction perpendicular to the center line L1 (width in the direction parallel to the center line L1) can be reduced compared to a case where there is no bending of the arm portions 13A and 13B. Furthermore, even if deformation occurs in the arm portions 13A and 13B, the narrow spacing between the arm portions 13A and 13B in the width direction makes it difficult for the arm portions 13A and 13B to come into contact with other members. This suppresses the deterioration of durability due to wear of the wire material 10 of the arm portions 13A and 13B.

[0043] In the torsion coil spring 1 according to this embodiment, when a load is applied to the arm portions 13A and 13B, torsional forces are easily applied to each wire 10 of the arm portions 13A and 13B due to the bending of the arm portion 13A as viewed from the first direction D1 (bending of the first portion 131A and the second portion 132A), the bending of the arm portion 13B as viewed from the first direction D1 (bending of the first portion 131B and the second portion 132B), the bending of the arm portion 13A as viewed from the reference direction D2A (bending of the third portion 133A and the fourth portion 134A), and the bending of the arm portion 13B as viewed from the reference direction D2B (bending of the third portion 133B and the fourth portion 134B).

[0044] Figure 2A is a diagram illustrating the torsional force acting on the wires 10 of arm sections 13A and 13B in the torsion coil spring 1 shown in Figures 1A to 1C. When an external force F is applied to narrow the distance between arm sections 13A and 13B, as shown in Figure 2A, opposing forces act on arm sections 13A and 13B, and the torsion coil spring 1 as a whole becomes susceptible to a rotational force in the direction of arrow R in Figure 2A. However, since the wires 10 of arm sections 13A and 13B are bent as described above (bending of arm sections 13A and 13B as seen from the first direction D1, bending of arm section 13A as seen from the reference direction D2A, and bending of arm section 13B as seen from the reference direction D2B), torsional forces tend to act on the wires 10 at these bent portions in the directions indicated by arrows T1 and T2 in Figure 2A. When a torsional force acts in the directions indicated by arrows T1 and T2, the rotational force in the direction of arrow R is canceled out and reduced, making it easier to suppress the overall rotation of the torsion coil spring 1. When the rotation of the torsion coil spring 1 is suppressed, the friction between the coil portion 12 and the member such as the guide rod inserted through the hole 121 in the coil portion 12 is reduced. Therefore, wear of the wire material 10 of the coil portion 12 is suppressed, and deterioration of durability can be suppressed.

[0045] Figure 2B is a diagram illustrating a comparative example corresponding to Figure 2A. The torsion coil spring of the comparative example shown in Figure 2B does not have the arm portion bent as in the torsion coil spring 1 of Figure 2A. Therefore, when an external force F is applied to narrow the distance between the two arm portions, the torsional force shown by arrows T1 and T2 in Figure 2A is not generated. Consequently, the rotational force acting on the torsion coil spring of the comparative example in the direction of arrow R is greater than that of the torsion coil spring 1 according to this embodiment.

[0046] As can be seen by comparing Figure 2A and Figure 2B, the torsion coil spring 1 in Figure 2A, in which the arm portions 13A and 13B are bent, has a narrower distance between the arm portions 13A and 13B in the direction parallel to the center line L1 (first direction D1) compared to the comparative example torsion coil spring shown in Figure 2B. Therefore, when comparing the case when the same external force F is applied, the torsion coil spring 1 shown in Figure 2A generates a smaller moment that causes rotation in the direction of arrow R compared to the comparative example torsion coil spring shown in Figure 2B. Accordingly, from this point of view as well, the torsion coil spring 1 according to this embodiment can effectively suppress wear of the wire 10 on the inner surface of the hole 121 of the coil portion 12.

[0047] In the torsion coil spring 1 according to this embodiment, the fourth portion 134A of the arm portion 13A, as viewed from the reference direction D2A, is located between a virtual straight line L4A and a perpendicular line L3A (Figure 1A), and the fourth portion 134B of the arm portion 13B, as viewed from the reference direction D2B, is located between a virtual straight line L4B and a perpendicular line L3B (Figure 1C). The virtual straight line L4A (Figure 1A), as viewed from the reference direction D2A, is parallel to the extension direction of the wire 10 of the coil portion 12 located in front of the center line L1, passes through the center of the wire 10 in the width direction, and is the straight line closest to the end portion 122A. The virtual straight line L4B, as viewed from the reference direction D2B, is parallel to the extension direction of the wire 10 of the coil portion 12 located in front of the center line L1, passes through the center of the wire 10 in the width direction, and is the straight line closest to the end portion 122B. This effectively suppresses deformation of the coil section 12 when force is applied to the arm section 13 (a state in which the spacing between the wires 10 widens on one side of the coil section 12 and narrows on the other side of the coil section 12). By suppressing such deformation of the coil section 12, wear of the wires 10 due to friction between the wires 10 in the coil section 12 can be suppressed.

[0048] In the torsion coil spring 1 according to this embodiment, the length of the first portion 131A as viewed from the first direction D1 and the length of the third portion 133A as viewed from the reference direction D2A are approximately equal in the arm portion 13A. This makes it possible to form the arm portion 13A by bending the wire 10, and to bend the first portion 131A and the second portion 132A as viewed from the first direction D1, and the third portion 133A and the fourth portion 134A as viewed from the reference direction D2A, in a single bending process. Therefore, the manufacturing process of the torsion coil spring 1 can be simplified.

[0049] In the torsion coil spring 1 according to this embodiment, the length of the third portion 133B as viewed from the reference direction D2B is shorter than the length of the first portion 131B as viewed from the first direction D1 in the arm portion 13B. That is, in the arm portion 13B, the position of the second bent portion 142B is closer to the end portion 122B than the position of the first bent portion 141B. As a result, the bending of the fourth portion 134B relative to the third portion 133B occurs at a location relatively close to the end portion 122B. Therefore, even if deformation occurs in the arm portion 13B due to a load, it becomes less likely to come into contact with adjacent members in the width direction parallel to the center line L1. Accordingly, deterioration of durability due to wear caused by friction between the wire material 10 of the arm portion 13B and other members can be suppressed.

[0050] According to the torsion coil spring 1 of this embodiment, by adjusting the bending position and angle of the arm portions 13A and 13B, it is possible to appropriately set the relationship between the elastic force acting on the arm portions 13A and 13B and the distance between the arm portions 13A and 13B (deflection angle). Therefore, when used, for example, as a fastener for jewelry, by adjusting the bending position and angle of the arm portions 13A and 13B, it is possible to set an elastic force that provides a comfortable operating feel in addition to the functionally necessary elastic force.

[0051] In the torsion coil spring 1 according to this embodiment, the angle between the first portion 131A and the second portion 132A of the arm portion 13A, as viewed from the first direction D1, is equal to the angle between the first portion 131B and the second portion 132B of the arm portion 13B, as viewed from the first direction D1. Also, in the torsion coil spring 1 according to this embodiment, the angle between the third portion 133A and the fourth portion 134A of the arm portion 13A, as viewed from the reference direction D2A, is equal to the angle between the third portion 133B and the fourth portion 134B of the arm portion 13B, as viewed from the reference direction D2B. As a result, the deflection and twisting of the wire material 10 caused by the load are more easily aligned in the arm portions 13A and 13B, and durability can be improved compared to the case where the deflection and twisting are concentrated in one of the arm portions 13A and 13B.

[0052] Next, another example of the torsion coil spring according to this embodiment is shown in Figures 3A to 3C. Figure 3A is a view of the torsion coil spring 2 from a direction parallel to the reference direction D2A. Figure 3B is a view of the torsion coil spring 2 from a direction parallel to the first direction D1 (a direction parallel to the center line L1). Figure 3C is a view of the torsion coil spring 2 from a direction parallel to the reference direction D2B.

[0053] The torsion coil spring 2 shown in Figures 3A to 3C, like the torsion coil spring 1 already described, has a coil section 22 in which a wire 20 is wound spirally, and two arm sections (23A, 23B) extending from both ends (222A, 222B) of the coil section 22. Each component of the torsion coil spring 2 shown in Figures 3A to 3C generally corresponds to each component of the torsion coil spring 1 shown in Figures 1A to 1C. Replacing the most significant digit of the code assigned to the components of the torsion coil spring 1 from "1" to "2" indicates the code of the component of the coil spring 2 that corresponds to the component of the torsion coil spring 1. For example, the first part 131B of the torsion coil spring 1 corresponds to the first part 231B of the torsion coil spring 2. Below, the coil spring 2 shown in Figures 3A to 3C will be explained, focusing on the differences from the torsion coil spring 1.

[0054] In the torsion coil spring 2 shown in Figures 3A and 3C, the coil portion 22 is formed by winding the wire 20 spirally three times and then winding it 100° in the same direction. The coil portion 22 is also formed by a so-called pitch winding method, in which gaps are left between the wires 20.

[0055] In the arm portion 23B of the torsion coil spring 2 shown in Figures 3B and 3C, the length from the end portion 222B to the first bent portion 241B when viewed from the first direction D1 is approximately the same as the length from the end portion 222B to the second bent portion 242B when viewed from the reference direction D2B.

[0056] In the torsion coil spring 2 shown in Figure 3B, the angle β1 between the extension direction of the second portion 232A and the tangent L2A, as viewed from the first direction D1, is approximately 25° (±5°), and the angle β2 between the extension direction of the second portion 232B and the tangent L2B, as viewed from the first direction D1, is approximately 45° (±5°). Also, the angle α between the tangent L2A and the tangent L2B is approximately 80° (±5°). Furthermore, in the torsion coil spring 2 shown in Figures 3A and 3C, the angle θ1 between the extension direction of the third portion 233A and the perpendicular L3A, as viewed from the reference direction D2A, and the angle θ2 between the extension direction of the third portion 233B and the perpendicular L3B, as viewed from the reference direction D2B, are both approximately 10° (±5°).

[0057] The torsion coil spring 2 shown in Figures 3A to 3C above also has the same characteristics as the torsion coil spring 1 that has already been explained.

[0058] Next, an example of applying the torsion coil spring 1 according to this embodiment to a clasp for jewelry will be described with reference to Figures 4A to 4B and 5A to 5B. Figures 4A and 4B are perspective views showing an example of a clasp 3 using the torsion coil spring 1 according to this embodiment. Figure 4A is a perspective view showing an example of jewelry 5 having the clasp 3. The jewelry 5 shown in Figure 4A connects separate linear members 4A and 4B, such as a necklace, with the clasp 3. Figure 4B shows the clasp 3 in the open state. Figure 5A is a side view of the clasp 3. Figure 5B is a cross-sectional view showing the internal structure of the clasp 3.

[0059] The fastener 3 has a first member 31 and a second member 32 that are rotatably connected by a connecting shaft 33 (Figure 5B). The end 311 of the first member 31 and the end 321 of the second member 32 are bent into a hook shape when viewed from the side, as shown in Figures 5A and 5B. A mounting portion 312 for attaching the linear member 4B by brazing or the like is provided at a position away from the end 311 of the first member 31. The first member 31 and the second member 32 can be opened, as shown in Figure 4B. In this open state, a gap is formed between the end 311 of the first member 31 and the end 321 of the second member 32. Through this gap, the ring member 41 of the linear member 4A can be introduced to the end 311 of the first member 31, and the end 311 can be hooked into the hole in the ring member 41.

[0060] When the end 311 of the first member 31 is hooked into the hole of the ring member 41, and the first member 31 and the second member 32 are closed, as shown in Figure 4A, the aforementioned gap between the end 311 and the end 321 is closed, and the tip of the end 321 of the second member 32 is inserted into the hole of the ring member 41. At this time, the ring member 41 hooked onto the end 311 is inserted into the closed space 30 surrounded by the first member 31 and the second member 32, and cannot escape from the closed space 30. As a result, the ring member 41 and the fastener 3 are connected.

[0061] As shown in Figure 5B, the connecting shaft 33 is inserted into the hole 121 of the coil portion 12 of the torsion coil spring 1. The torsion coil spring 1 biases the first member 31 and the second member 32 so as to apply a rotational force in the direction that maintains the closed state described above. The tip of one arm portion 13 (for example, arm portion 13B) of the torsion coil spring 1 contacts the inner wall of the first member 31, and the tip of the other arm portion 13 (for example, arm portion 13A) contacts the inner wall of the second member 32.

[0062] To open the first member 31 and the second member 32 from a closed position, a finger or the like is hooked onto the operating part 323 protruding from the outer surface of the first member 31, and the first member 31 and the second member 32 are rotated against the biasing force of the torsion coil spring 1.

[0063] The torsion coil spring 1 is housed inside the fastener 3 in a narrow space sandwiched between the two side walls 313 of the first member 31. However, since the torsion coil spring 1 can generate a relatively large elastic force even in a small size, it can bias the first member 31 and the second member 32 with an appropriate elastic force even when used in a small fastener 3.

[0064] In the above explanation, an example was given in which torsion coil spring 1 (Figures 1A to 1C) is applied to fastener 3, but it is also possible to apply torsion coil spring 2 (Figures 3A to 3C) to fastener 3.

[0065] Next, a method for manufacturing the torsion coil spring 1 according to this embodiment will be described.

[0066] Figure 6A is a flowchart illustrating an example of a manufacturing method for the torsion coil spring 1. In the manufacturing method shown in Figure 6A, first, a coil portion 12 is formed by winding the wire 10 in a spiral shape (ST100). Next, arm portions 13A and 13B are formed, respectively, extending from the ends 122A and 122B on both sides of the coil portion 12 toward the tips 135A and 135B (ST105).

[0067] Figure 6B is a flowchart illustrating an example of the procedure (ST105: Figure 6A) for forming the arm sections (13A, 13B).

[0068] ST200: In the procedure for forming the arm sections (13A, 13B) shown in Figure 6B, first, the wires 10 extending from both ends 122A and 122B of the coil section 12 are extended in a certain direction. That is, the wire 10 extending from end 122A is extended in a direction along the tangent line L2A when viewed from the first direction D1, and in a direction along the perpendicular line L3A when viewed from the reference direction D2A. Also, the wire 10 extending from end 122B is extended in a direction along the tangent line L2B when viewed from the first direction D1, and in a direction along the perpendicular line L3B when viewed from the reference direction D2B (ST200). This forms the basis for the first section 131A and the third section 133A in arm section 13A, and the basis for the first section 131B and the third section 133B in arm section 13B.

[0069] ST205: Next, the wires 10 at ends 122A and 122B, which were extended in a certain direction in step ST200, are bent in a certain direction when viewed from the first direction D1. That is, the wire 10 extending from end 122A is bent at the first bend 141A. Also, the wire 10 extending from end 122B is bent at the first bend 141B (ST205).

[0070] In the process of bending the wire 10 at the first bending portion 141A, the angle between the first portion 131A from the end 122A to the first bending portion 141A and the second portion 132A from the first bending portion 141A to the tip 135A is made obtuse when viewed from the first direction D1, and the second portion 132A when viewed from the first direction D1 is bent to the opposite side of the tangent L2A from the side where the hole 121 is located. In the process of bending the wire 10 at the first bending portion 141B, the angle between the first portion 131B from the end portion 122B to the first bending portion 141B and the second portion 132B from the first bending portion 141B to the tip portion 135B is made obtuse when viewed from the first direction D1, and the second portion 132B when viewed from the first direction D1 is bent to the opposite side of the tangent L2B from the side where the hole 121 is located.

[0071] ST210: Furthermore, in step ST200, the wires 10 at ends 122A and 122B, which are extended in a certain direction, are bent in a certain direction when viewed from the reference direction D2A and D2B, respectively. That is, the wire 10 extending from end 122A is bent at the second bending portion 142A. Also, the wire 10 extending from end 122B is bent at the second bending portion 142B (ST210).

[0072] In the process of bending the wire 10 at the second bending portion 142A, the angle between the third portion 133A from the end portion 122A to the second bending portion 142A and the fourth portion 134A from the second bending portion 142A to the tip portion 135A is made obtuse when viewed from the reference direction D2A, and the fourth portion 134A when viewed from the reference direction D2A is bent toward the side where the coil portion 12 is located relative to the perpendicular line L3A. In the process of bending the wire 10 at the second bending portion 142B, the angle between the third portion 133B from the end portion 122B to the second bending portion 142B and the fourth portion 134B from the second bending portion 142B to the tip portion 135B is made obtuse when viewed from the reference direction D2B, and the fourth portion 134B when viewed from the reference direction D2B is bent toward the side where the coil portion 12 is located relative to the perpendicular L3B.

[0073] Note that the order of the folding process in step ST205 and the folding process in step ST210 may be reversed.

[0074] Furthermore, as shown in Figures 1A and 1B, the length of the first portion 131A of the arm portion 13A as viewed from the first direction D1 is equal to the length of the third portion 133A as viewed from the reference direction D2A. Therefore, the position of the first bend portion 141A where the wire 10 is bent in step ST205 is equal to the position of the second bend portion 142A where the wire 10 is bent in step ST210. In such cases, the bending of the wire 10 in step ST205 and the bending of the wire 10 in step ST210 may be performed simultaneously at the same position on the wire 10. That is, the bending process in step ST205 and the bending process in step ST210 may be combined into a single bending process in which the wire 10 is bent only once in a predetermined direction. This simplifies the manufacturing process.

[0075] Each step in the manufacturing method of the torsion coil spring 1 described above may be performed manually, or at least some of the steps may be performed using machine tools.

[0076] The method for manufacturing the torsion coil spring 1 described above is applicable to the method for manufacturing the torsion coil spring 2 shown in Figures 3A to 3C, and is also applicable to other methods for manufacturing torsion coil springs according to this embodiment.

[0077] The above-described embodiment of the torsion coil spring and its manufacturing method is an example, and this embodiment may include various further modifications.

[0078] For example, the number of turns of the wire in the coil portion of a torsion coil spring, the thickness of the wire, the cross-sectional shape of the wire 10, the ratio of the outer diameter to the inner diameter of the coil portion, the bending position of the arm portion as viewed from each direction, the length of each straight portion of the arm portion as viewed from each direction, the bending angle of each straight portion of the arm portion as viewed from each direction, and the angle between the straight portions of two arm portions are not limited to the examples shown in Figures 1A to 1C and Figures 3A to 3C.

[0079] In this embodiment, the torsion coil spring may have two arms with the same configuration. That is, in the two arms, the lengths of the first part as viewed from the first direction may be equal, the lengths of the second part as viewed from the first direction may be equal, the lengths of the third part as viewed from the reference direction may be equal, the lengths of the fourth part as viewed from the reference direction may be equal, the angles between the first and second parts as viewed from the first direction may be equal, and the angles between the third and fourth parts as viewed from the reference direction may be equal. With such a torsion coil spring, when incorporating it into fasteners for jewelry, etc., there is no need to distinguish between the two arms, thus simplifying the manufacturing process.

[0080] In the torsion coil spring of this embodiment, β1 and β2 (Figures 1B and 3B) can each be changed within a range of 5° to 50°. Also, θ1 and θ2 (Figures 1B and 3B) can each be changed within a range of more than 0° and up to 10°. β1 and β2 may be the same or different. θ1 and θ2 may be the same or different.

[0081] In the embodiments shown in Figures 4A-4B and 5A-5B, the accessory fastener 3 is a pre-assembled finished product, but the present invention is not limited to these embodiments. That is, embodiments of the present invention also include assembly sets for assembling the accessory fastener. For example, the assembly set of the accessory fastener 3 shown in Figures 4A-4B and 5A-5B includes a first member 31 and a second member 32, and a torsion coil spring 1 (or torsion coil spring 2) as a biasing member. The assembly set of the accessory fastener 3 may also include a connecting shaft 33.

[0082] Furthermore, the torsion coil spring according to this embodiment is not limited to fasteners for jewelry, but can be applied to various devices and other equipment, and is particularly useful for devices that require miniaturization.

[0083] The following are appendices A1 to A12 relating to one aspect of the present invention.

[0084] [Note A1] A coil section (12, 22) in which wire (10, 20) is wound in a spiral shape, Two arm sections (13A, 13B, 23A, 23B) extend from both ends (122A, 122B, 222A, 222B) of the coil section (12, 22) toward the respective tip (135A, 135B, 235A, 235B), Equipped with, The central holes (121, 221) of the coil sections (12, 22) are circular when viewed from a first direction (D1) parallel to the center line (L1) of the spiral shape. The two arm sections (13A, 13B, 23A, 23B) are defined by different reference directions (D2A, D2B) perpendicular to the center line (L1), different circular tangent lines (L2A, L2B), and different perpendicular lines (L3A, L3B) perpendicular to the center line (L1) when viewed from the reference directions (D2A, D2B). Each of the aforementioned ends (122A, 122B, 222A, 222B) of the coil section (12, 22) is, It is in contact with the tangents (L2A, L2B) that define one of the arm portions (13A, 13B, 23A, 23B) extending from one of the ends (122A, 122B, 222A, 222B), When viewed from the reference direction (D2A, D2B) that defines one of the arm portions (13A, 13B, 23A, 23B), it is located behind the center line (L1), and With respect to the reference direction (D2A, D2B) defining one of the arm portions (13A, 13B, 23A, 23B), the perpendicular line (L3A, L3B) defining one of the arm portions (13A, 13B, 23A, 23B) is in contact with the edge in the first direction (D1), Each of the arm portions (13A, 13B, 23A, 23B) as viewed from the first direction (D1) is, It has a first bent section (141A, 141B, 241A, 241B), A first portion (131A, 131B, 231A, 231B) from one of the ends (122A, 122B, 222A, 222B) of one of the arm portions (13A, 13B, 23A, 23B) to the first bent portion (141A, 141B, 241A, 241B) extends in a direction along the tangent lines (L2A, L2B) that define the one arm portion (13A, 13B, 23A, 23B), The second portion (132A, 132B, 232A, 232B) from the first bent portion (141A, 141B, 241A, 241B) to the tip (135A, 135B, 235A, 235B) and the first portion (131A, 131B, 231A, 231B) form an obtuse angle, and, The second portion (132A, 132B, 232A, 232B) is bent on the opposite side of the side where the holes (121, 221) are located, with respect to the tangents (L2A, L2B) that define one of the arm portions (13A, 13B, 23A, 23B). Each of the arm portions (13A, 13B, 23A, 23B) as viewed from the aforementioned reference direction (D2A, D2B) is, It has a second bending section (142A, 142B, 242A, 242B), A third portion (133A, 133B, 233A, 233B) from one of the ends (122A, 122B, 222A, 222B) extending from one of the arm portions (13A, 13B, 23A, 23B) to the second bent portion (142A, 142B, 242A, 242B) extends in a direction along the perpendicular line (L3A, L3B) that defines the one arm portion (13A, 13B, 23A, 23B), The fourth portion (134A, 134B, 234A, 234B) from the second bent portion (142A, 142B, 242A, 242B) to the tip (135A, 135B, 235A, 235B) and the third portion (133A, 133B, 233A, 233B) form an obtuse angle, and, The fourth portion (134A, 134B, 234A, 234B) is bent toward the side where the coil portion (12, 22) is located relative to the perpendicular line (L3A, L3B) that defines one of the arm portions (13A, 13B, 23A, 23B). Torsion coil spring. [Appendix A2] The two arm sections (13A, 13B, 23A, 23B) are defined by different virtual lines (L4A, L4B), respectively. The virtual straight lines (L4A, L4B) defining each of the arm portions (13A, 13B, 23A, 23B) are, when viewed from the reference direction (D2A, D2B) defining one of the arm portions (13A, 13B, 23A, 23B), parallel to the extension direction of the wire material (10, 20) of the coil portion (12, 22) located in front of the center line (L1), passing through the center of the wire material (10, 20) in the width direction, and being the straight line closest to the end portion (122A, 122B, 222A, 222B) to which the one arm portion (13A, 13B, 23A, 23B) extends. Each of the arm portions (13A, 13B, 23A, 23B) viewed from the aforementioned reference direction (D2A, D2B) is such that the fourth portion (134A, 134B, 234A, 234B) is located between the perpendicular line (L3A, L3B) defining one of the arm portions (13A, 13B, 23A, 23B) and the virtual straight line (L4A, L4B) defining that one of the arm portions (13A, 13B, 23A, 23B). Torsion coil springs (1, 2) as described in Appendix A1. [Note A3] At least one of the arm portions (13A, 23A, 23B) has a length equal to the length of the first portion (131A, 231A, 231B) as viewed from the first direction (D1) and the length of the third portion (133A, 233A, 233B) as viewed from the reference direction (D2A, D2B). Torsion coil springs (1, 2) as described in Appendix A1 or A2. [Note A4] At least one of the arm portions (13A, 23A, 23B) is such that, when viewed from the first direction (D1), the length of the first portion (131A, 231A, 231B) is less than or equal to the length of the second portion (132A, 232A, 232B), and when viewed from the reference direction (D2A, D2B), the length of the third portion (133A, 233A, 233B) is less than or equal to the length of the fourth portion (134A, 234A, 234B). Torsion coil springs (1, 2) as described in one of the appendices A1 to A3. [Note A5] The angle between the first portion (131A, 231A) and the second portion (132A, 232A) of one of the arm portions (13A, 23A) as viewed from the first direction (D1) is equal to the angle between the first portion (131B, 231B) and the second portion (132B, 232B) of the other arm portion (13B, 23B) as viewed from the first direction (D1). Torsion coil springs (1, 2) as described in one of the appendices A1 to A4. [Note A6] The angle between the third portion (133A, 233A) and the fourth portion (134A, 234A) of one arm portion (13A, 23A), as viewed from the reference direction (D2A) defining one arm portion (13A, 23A), is equal to the angle between the third portion (133B, 233B) and the fourth portion (134B, 234B) of the other arm portion (13B, 23B), as viewed from the reference direction (D2B) defining the other arm portion (13B, 23B). Torsion coil springs (1, 2) as described in one of the appendices A1 to A5. [Note A7] A torsion coil spring (1, 2) described in one of the appendices A1 to A6, used for fastening (3) of an ornament (5). [Note A8] The process (ST100) involves winding wire (10, 20) in a spiral shape to form a coil section (12, 22), The process includes (ST105) of forming two arm portions (13A, 13B, 23A, 23B) that extend from both ends (122A, 122B, 222A, 222B) of the coil portion (12, 22) toward the respective tip (135A, 135B, 235A, 235B), The central holes (121, 221) of the coil sections (12, 22) are circular when viewed from a first direction (D1) parallel to the center line (L1) of the spiral shape. The two arm sections (13A, 13B, 23A, 23B) are defined by different reference directions (D2A, D2B) perpendicular to the center line (L1), different circular tangent lines (L2A, L2B), and different perpendicular lines (L3A, L3B) perpendicular to the center line (L1) when viewed from the reference directions (D2A, D2B). Each of the aforementioned ends (122A, 122B, 222A, 222B) of the coil section (12, 22) is, It is in contact with the tangents (L2A, L2B) that define one of the arm portions (13A, 13B, 23A, 23B) extending from one of the ends (122A, 122B, 222A, 222B), When viewed from the reference direction (D2A, D2B) that defines one of the arm portions (13A, 13B, 23A, 23B), it is located behind the center line (L1), and With respect to the reference direction (D2A, D2B) defining one of the arm portions (13A, 13B, 23A, 23B), the perpendicular line (L3A, L3B) defining one of the arm portions (13A, 13B, 23A, 23B) is in contact with the edge in the first direction (D1), The step (ST105) of forming each of the aforementioned arm portions (13A, 13B, 23A, 23B) is as follows: A first process (ST200) involves extending the wire (10, 20) extending from one of the ends (122A, 122B, 222A, 222B) corresponding to one of the arm portions (13A, 13B, 23A, 23B) in a direction along the tangent lines (L2A, L2B) defining the one arm portion (13A, 13B, 23A, 23B) when viewed from the first direction (D1), and extending it in a direction along the perpendicular lines (L3A, L3B) defining the one arm portion (13A, 13B, 23A, 23B) when viewed from the reference direction (D2A, D2B) defining the one arm portion (13A, 13B, 23A, 23B), After the first process (ST200), a second process (ST205) is performed in which the wire (10,20) extending from one end (122A, 122B, 222A, 222B) is bent at the first bending portion (141A, 141B, 241A, 241B), The process includes, after the first process (ST200), a third process (ST210) in which the wire (10, 20) extending from one end (122A, 122B, 222A, 222B) is bent at a second bending portion (142A, 142B, 242A, 242B), The second process (ST205) is, The angle between the first portion (131A, 131B, 231A, 231B) from one end (122A, 122B, 222A, 222B) to the first bent portion (141A, 141B, 241A, 241B) and the second portion (132A, 132B, 232A, 232B) from the first bent portion (141A, 141B, 241A, 241B) to the tip (135A, 135B, 235A, 235B) is made obtuse when viewed from the first direction (D1). This includes bending the second portion (132A, 132B, 232A, 232B) as viewed from the first direction (D1) toward the opposite side of the side where the holes (121, 221) are located, with respect to the tangents (L2A, L2B) that define the one arm portion (13A, 13B, 23A, 23B), The third process (ST210) is, With respect to the reference direction (D2A, D2B) defining one arm portion (13A, 13B, 23A, 23B), the angle between the third portion (133A, 133B, 233A, 233B) from one end portion (122A, 122B, 222A, 222B) to the second bent portion (142A, 142B, 242A, 242B) and the fourth portion (134A, 134B, 234A, 234B) from the second bent portion (142A, 142B, 242A, 242B) to the tip (135A, 135B, 235A, 235B) is made obtuse. This includes bending the fourth portion (134A, 134B, 234A, 234B) as viewed from the reference direction (D2A, D2B) defining one of the arm portions (13A, 13B, 23A, 23B) toward the side where the coil portion (12, 22) is located, with respect to the perpendicular line (L3A, L3B) defining one of the arm portions (13A, 13B, 23A, 23B), A method for manufacturing torsion coil springs (1, 2). [Note A9] The step (ST105) of forming at least one of the arm portions (13A, 23A, 23B) is to perform the bending in the second step (ST205) at the first bent portion (141A, 241A, 241B) and the bending in the third step (ST210) at the second bent portion (142A, 242A, 242B) simultaneously at the same position on the wire (10, 20). The method for manufacturing the torsion coil springs (1, 2) described in Appendix A8. [Note A10] First member (31) and A second member (32) is rotatably connected to the first member (31), Torsion coil springs (1, 2) as described in any one of the appendices A1 to A6, which provide a biasing force to rotate the first member (31) and the second member (32), and A fastener (3) for jewelry, comprising: [Note A11] First member (31) and A second member (32) is rotatably connected to the first member (31), Torsion coil springs (1, 2) as described in any one of the appendices A1 to A6, which provide a biasing force to rotate the first member (31) and the second member (32), and An assembly set of fasteners (3) for jewelry, which are equipped with the following. [Note A12] An accessory (5) equipped with the accessory fastener (3) described in Appendix A10.

[0085] The following are appendices B1 to B12 relating to another aspect of the present invention.

[0086] [Note B1] A coil section (12, 22) in which wire (10, 20) is wound in a spiral shape, First arm portions (13A, 23A) extending from the first ends (122A, 222A) of the coil portions (12, 22), The second arm portions (13B, 23B) extend from the second ends (122B, 222B) of the coil portions (12, 22) and Equipped with, The central holes (121, 221) of the coil sections (12, 22) are circular when viewed from a first direction (D1) parallel to the center line (L1) of the spiral shape. The first end (122A, 222A) is tangent to the first tangent (L2A), which is the circular tangent, and is located behind the center line (L1) when viewed from the first reference direction (D2A), which is perpendicular to the center line (L1), and is tangent to the first perpendicular (L3A), which is perpendicular to the center line (L1), at its edge in the first direction (D1) when viewed from the first reference direction (D2A). The second end (122B, 222B) is tangent to the second tangent (L2B), which is the circular tangent, and is located behind the center line (L1) when viewed from the second reference direction (D2B), which is perpendicular to the center line (L1), and is tangent to the second perpendicular (L3B), which is perpendicular to the center line (L1), when viewed from the second reference direction (D2B), at its edge in the first direction (D1). The first arm portion (13A, 23A), as viewed from the first direction (D1), has a first bent portion (141A, 241A), and the first portion (131A, 231A) from the first end (122A, 222A) to the first bent portion (141A, 241A) extends in a direction along the first tangent (L2A), and the second portion (132A, 232A) from the first bent portion (141A, 241A) to the tip (135A, 235A) of the first arm portion (13A, 23A) and the first portion (131A, 231A) form an obtuse angle, and the second portion (132A, 232A) is bent on the opposite side of the first tangent (L2A) from the side where the holes (121, 221) are located. The second arm portion (13B, 23B) as viewed from the first direction (D1) has a second bent portion (141B, 241B), and the third portion (131B, 231B) from the second end (122B, 222B) to the second bent portion (141B, 241B) extends in a direction along the second tangent (L2B), and the fourth portion (132B, 232B) from the second bent portion (141B, 241B) to the tip (135B, 235B) of the second arm portion (13B, 23B) and the third portion (131B, 231B) form an obtuse angle, and the fourth portion (132B, 232B) is bent on the opposite side of the second tangent (L2B) from the side where the holes (121, 221) are located. The first arm portion (13A, 23A), as viewed from the first reference direction (D2A), has a third bent portion (142A, 242A), and the fifth portion (133A, 233A) from the first end (122A, 222A) to the third bent portion (142A, 242A) extends in a direction along the first perpendicular (L3A), and the sixth portion (134A, 234A) from the third bent portion (142A, 242A) to the tip (135A, 235A) of the first arm portion (13A, 23A) and the fifth portion (133A, 233A) form an obtuse angle, and the sixth portion (134A, 234A) is bent with respect to the first perpendicular (L3A) toward the coil portion (12, 22). The second arm portion (13B, 23B), as viewed from the second reference direction (D2B), has a fourth bent portion (142B, 242B), and the seventh portion (133B, 233B), from the second end portion (122B, 222B) to the fourth bent portion (142B, 242B), extends in a direction along the second perpendicular (L3B), and the eighth portion (134B, 234B), from the fourth bent portion (142B, 242B) to the tip (135B, 235B) of the second arm portion (13B, 23B), forms an obtuse angle with respect to the seventh portion (133B, 233B), and the eighth portion (134B, 234B) is bent toward the side where the coil portion (12, 22) is located relative to the second perpendicular (L3B). Torsion coil springs (1, 2). [Note B2] As viewed from the first reference direction (D2A), the first arm portion (13A, 23A) has the sixth portion (134A, 234A) located between the first perpendicular (L3A) and the first virtual straight line (L4A). The first virtual straight line (L4A), as viewed from the first reference direction (D2A), is parallel to the extension direction of the wire material (10, 20) of the coil portion (12, 22) located in front of the center line (L1), passes through the center of the wire material (10, 20) in the width direction, and is the straight line closest to the first end (122A, 222A). As viewed from the second reference direction (D2B), the second arm portion (13B, 23B) has the eighth portion (134B, 234B) located between the second perpendicular (L3B) and the second virtual straight line (L4B). The second virtual straight line (L4B), as viewed from the second reference direction (D2B), is parallel to the extension direction of the wire material (10, 20) of the coil section (12, 22) located in front of the center line (L1), passes through the center of the wire material (10, 20) in the width direction, and is the straight line closest to the second end (122B, 222B). Torsion coil springs (1, 2) as described in Appendix B1. [Note B3] The first arm portion (13A, 23A) has a length equal to the length of the first part (131A, 231A) as viewed from the first direction (D1) and the length of the fifth part (133A, 233A) as viewed from the first reference direction (D2A). and / or, The second arm portion (13B, 23B) has a length equal to the length of the third portion (131B, 231B) as viewed from the first direction (D1) and the length of the seventh portion (133B, 233B) as viewed from the second reference direction (D2B). Torsion coil springs (1, 2) as described in Appendix B1 or B2. [Note B4] The first arm portion (13A, 23A) is such that, when viewed from the first direction (D1), the length of the first portion (131A, 231A) is less than or equal to the length of the second portion (132A, 232A), and when viewed from the first reference direction (D2A), the length of the fifth portion (133A, 233A) is less than or equal to the length of the sixth portion (134A, 234A). and / or, The second arm portion (13B, 23B) is such that, when viewed from the first direction (D1), the length of the third portion (131B, 231B) is less than or equal to the length of the fourth portion (132B, 232B), and when viewed from the second reference direction (D2B), the length of the seventh portion (133B, 233B) is less than or equal to the length of the eighth portion (134B, 234B). Torsion coil springs (1, 2) as described in one of the appendices B1 to B3. [Note B5] The angle between the first portion (131A, 231A) and the second portion (132A, 232A) of the first arm portion (13A, 23A) as viewed from the first direction (D1) is equal to the angle between the third portion (131B, 231B) and the fourth portion (132B, 232B) of the second arm portion (13B, 23B) as viewed from the first direction (D1). Torsion coil springs (1, 2) as described in one of the appendices B1 to B4. [Note B6] The angle between the fifth portion (133A, 233A) and the sixth portion (134A, 234A) of the first arm portion (13A, 23A) as viewed from the first reference direction (D2A) is equal to the angle between the seventh portion (133B, 233B) and the eighth portion (134B, 234B) of the second arm portion (13B, 23B) as viewed from the second reference direction (D2B). Torsion coil springs (1, 2) as described in one of the appendices B1 to B5. [Note B7] A torsion coil spring (1, 2) described in one of the appendices B1 to B6, used in the fastener (3) of the jewelry (5). [Note B8] The process (ST100) involves winding wire (10, 20) in a spiral shape to form a coil section (12, 22), Step (ST105) of forming first arm portions (13A, 23A) extending from the first ends (122A, 222A) of the coil portions (12, 22), The process includes (ST105) forming second arm portions (13B, 23B) extending from the second ends (122B, 222B) of the coil portions (12, 22), The central holes (121, 221) of the coil sections (12, 22) are circular when viewed from a first direction (D1) parallel to the center line (L1) of the spiral shape. The first end (122A, 222A) is tangent to the first tangent (L2A), which is the circular tangent, and is located behind the center line (L1) when viewed from the first reference direction (D2A), which is perpendicular to the center line (L1), and is tangent to the first perpendicular (L3A), which is perpendicular to the center line (L1), at its edge in the first direction (D1) when viewed from the first reference direction (D2A). The second end (122B, 222B) is tangent to the second tangent (L2B), which is the circular tangent, and is located behind the center line (L1) when viewed from the second reference direction (D2B), which is perpendicular to the center line (L1), and is tangent to the second perpendicular (L3B), which is perpendicular to the center line (L1), when viewed from the second reference direction (D2B), at its edge in the first direction (D1). The step (ST105) of forming the first arm portion (13A, 23A) is, A first process (ST200) involves extending the wires (10, 20) extending from the first ends (122A, 222A) in a direction along the first tangent line (L2A) when viewed from the first direction (D1), and also in a direction along the first perpendicular line (L3A) when viewed from the first reference direction (D2A), After the first process (ST200), the wires (10, 20) extending from the first ends (122A, 222A) are bent at the first bent portions (141A, 241A) in a second process (ST205), The process includes a third step (ST210) in which, after the first step (ST200), the wires (10, 20) extending from the first ends (122A, 222A) are bent at the third bends (142A, 242A), The second process (ST205) is, The angle between the first portion (131A, 231A) from the first end (122A, 222A) to the first bent portion (141A, 241A) and the second portion (132A, 232A) from the first bent portion (141A, 241A) to the tip (135A, 235A) of the first arm portion (13A, 23A) is made obtuse when viewed from the first direction (D1), This includes bending the second portion (132A, 232A) as viewed from the first direction (D1) toward the opposite side of the first tangent (L2A) from the side where the holes (121, 221) are located, The third process (ST210) is, The angle between the fifth portion (133A, 233A) from the first end (122A, 222A) to the third bent portion (142A, 242A) and the sixth portion (134A, 234A) from the third bent portion (142A, 242A) to the tip (135A, 235A) of the first arm portion (13A, 23A) is made obtuse when viewed from the first reference direction (D2A), This includes bending the sixth portion (134A, 234A) as viewed from the first reference direction (D2A) toward the side where the coil portion (12, 22) is located relative to the first perpendicular (L3A), The step (ST105) of forming the second arm portion (13B, 23B) is as follows: A fourth process (ST200) involves extending the wires (10, 20) extending from the second ends (122B, 222B) in a direction along the second tangent line (L2B) when viewed from the first direction (D1), and also in a direction along the second perpendicular line (L3B) when viewed from the second reference direction (D2B), Following the fourth process (ST200), the fifth process (ST205) involves bending the wires (10, 20) extending from the second ends (122B, 222B) at the second bends (141B, 241B), The process includes a sixth step (ST210) in which, after the fourth step (ST200), the wires (10, 20) extending from the second ends (122B, 222B) are bent at the fourth bends (142B, 242B), The fifth process (ST205) is, The angle between the third portion (131B, 231B) from the second end (122B, 222B) to the second bent portion (141B, 241B) and the fourth portion (132B, 232B) from the second bent portion (141B, 241B) to the tip (135B, 235B) of the second arm portion (13B, 23B) is made obtuse when viewed from the first direction (D1), This includes bending the fourth portion (132B, 232B) as viewed from the first direction (D1) toward the opposite side of the second tangent (L2B) from the side where the holes (121, 221) are located, The sixth process (ST210) is, The angle between the seventh section (133B, 233B) from the second end (122B, 222B) to the fourth bent section (142B, 242B) and the eighth section (134B, 234B) from the fourth bent section (142B, 242B) to the tip (135B, 235B) of the second arm section (13B, 23B) is made obtuse when viewed from the second reference direction (D2B). This includes bending the eighth portion (134B, 234B) as viewed from the second reference direction (D2B) toward the side where the coil portion (12, 22) is located relative to the second perpendicular (L3B), A method for manufacturing torsion coil springs (1, 2). [Note B9] The step (ST105) of forming the first arm portion (13A, 23A) is to perform the bending in the second step (ST205) at the first bent portion (141A, 241A) and the bending in the third step (ST210) at the third bent portion (142A, 242A) simultaneously at the same position on the wire (10, 20). and / or, The step (ST105) of forming the second arm portion (13B, 23B) is to perform the bending in the fifth step (ST205) at the second bent portion (141B, 241B) and the bending in the sixth step (ST210) at the fourth bent portion (142B, 242B) simultaneously at the same position on the wire (10, 20). A method for manufacturing the torsion coil springs (1, 2) described in Appendix B8. [Note B10] First member (31) and A second member (32) is rotatably connected to the first member (31), Torsion coil springs (1, 2) described in any one of the appendices B1 to B6 provide a biasing force to rotate the first member (31) and the second member (32), and A fastener (3) for jewelry, comprising: [Note B11] First member (31) and A second member (32) is rotatably connected to the first member (31), Torsion coil springs (1, 2) described in any one of the appendices B1 to B6 provide a biasing force to rotate the first member (31) and the second member (32), and An assembly set of fasteners (3) for jewelry, which are equipped with the following. [Note B12] An accessory (5) equipped with the accessory fastener (3) described in Appendix B10. [Explanation of symbols]

[0087] 1,2...torsion coil spring, 10,20...wire, 12,22...coil section, 121,221...hole, 122A,122B,222A,222B...end of coil section, 13A,13B,23A,23B...arm section, 131A,131B,231A,231B...first section, 132A,132B,232A,232B...second section, 133A,133B,233A,233B...third section, 134A,1 34B, 234A, 234B...Fourth part, 3...Fastener, 31...First member, 311...End, 312...Mounting part, 313...Side wall, 32...Second member, 321...End, 323...Operating part, 33...Connecting shaft, 4A, 4B...Linear member, 41...Ring member, 5...Ornament, D1...First direction, D2A, D2B...Reference direction, L1...Centerline, L2A, L2B...Tangential, L3A, L3B...Perpendicular, L4A, L4B...Imaginary straight line

Claims

1. The coil section, in which the wire is wound in a spiral shape, Two arm portions extending from both ends of the coil portion toward the tip, Equipped with, The central hole of the coil portion has a circular shape when viewed from a first direction parallel to the center line of the spiral shape. The two arm portions are defined by different reference directions perpendicular to the center line, different circular tangents, and different perpendiculars perpendicular to the center line when viewed from the reference directions. Each of the ends of the coil portion is It is in contact with the tangent that defines one of the arm portions extending from one of the ends, When viewed from the reference direction defining the one arm portion, it is located behind the center line, and Viewed from the reference direction defining the one arm portion, the perpendicular line defining the one arm portion is in contact with the edge in the first direction, Each of the arm portions viewed from the first direction is, Having a first bend, The first portion of one arm extends from one end to the first bent portion in a direction along the tangent that defines the one arm, The second portion from the first bend to the tip and the first portion form an obtuse angle, and The second portion is bent on the opposite side of the side where the hole is located, with respect to the tangent line defining the one arm portion. Each of the arm portions viewed from the aforementioned reference direction is, It has a second bending section, The third portion from one end of the arm portion to the second bent portion extends in a direction along the perpendicular line defining the arm portion, The fourth portion from the second bend to the tip and the third portion form an obtuse angle, and The fourth portion is bent toward the side where the coil portion is located with respect to the perpendicular line defining the one arm portion. Torsion coil spring.

2. The two arm sections are each defined by different virtual lines, The imaginary straight line defining each arm portion is, when viewed from the reference direction defining one arm portion, parallel to the extension direction of the wire material of the coil portion located in front of the center line, passing through the center of the wire material in the width direction, and being the straight line closest to the end portion to which the arm portion extends. Each of the arm portions viewed from the aforementioned reference direction has the fourth portion located between the perpendicular line defining one of the arm portions and the imaginary straight line defining that one of the arm portions. A torsion coil spring according to claim 1.

3. At least one of the arm portions has a length equal to the length of the first portion as viewed from the first direction and the length of the third portion as viewed from the reference direction. A torsion coil spring according to claim 1 or 2.

4. At least one of the arm portions is such that, when viewed from the first direction, the length of the first portion is less than or equal to the length of the second portion, and when viewed from the reference direction, the length of the third portion is less than or equal to the length of the fourth portion. A torsion coil spring according to any one of claims 1 to 3.

5. The angle formed by the first and second parts of one of the arm portions as viewed from the first direction is equal to the angle formed by the first and second parts of the other arm portion as viewed from the first direction. A torsion coil spring according to any one of claims 1 to 4.

6. The angle between the third and fourth portions of one arm as viewed from the reference direction defining one arm is equal to the angle between the third and fourth portions of the other arm as viewed from the reference direction defining the other arm. A torsion coil spring according to any one of claims 1 to 5.

7. A torsion coil spring according to any one of claims 1 to 6, used as a fastener for jewelry.

8. The process involves forming a coil by winding the wire in a spiral shape, The process includes forming two arm portions that extend from both ends of the coil portion toward the tip, The central hole of the coil portion has a circular shape when viewed from a first direction parallel to the center line of the spiral shape. The two arm portions are defined by different reference directions perpendicular to the center line, different circular tangents, and different perpendiculars perpendicular to the center line when viewed from the reference directions. Each of the ends of the coil portion is It is in contact with the tangent that defines one of the arm portions extending from one of the ends, When viewed from the reference direction defining the one arm portion, it is located behind the center line, and Viewed from the reference direction defining the one arm portion, the perpendicular line defining the one arm portion is in contact with the edge in the first direction, The process of forming each of the aforementioned arm portions is as follows: A first step is to extend the wire extending from one end corresponding to one of the arm portions in a direction along the tangent line defining the one arm portion when viewed from the first direction, and in a direction along the perpendicular line defining the one arm portion when viewed from the reference direction defining the one arm portion, Following the first process, a second process is performed in which the wire extending from one end is bent at the first bend, The process includes, after the first step, a third step of bending the wire extending from one end at a second bending portion, The second process described above is: The angle between the first portion from one end to the first bend and the second portion from the first bend to the tip is made obtuse when viewed from the first direction, This includes bending the second portion, as viewed from the first direction, to the side opposite to the side where the hole is located, with respect to the tangent line defining the one arm portion, The 3rd configuration process is, When viewed from the reference direction defining the one arm portion, the angle between the third portion from the one end to the second bent portion and the fourth portion from the second bent portion to the tip is made obtuse, This includes bending the fourth portion, as viewed from the reference direction defining the one arm portion, toward the side where the coil portion is located, with respect to the perpendicular line defining the one arm portion. A method for manufacturing torsion coil springs.

9. The step of forming at least one of the arm portions involves performing the second bending process at the first bending portion and the third bending process at the second bending portion simultaneously at the same position on the wire. A method for manufacturing a torsion coil spring according to claim 8.

10. First member and A second member rotatably connected to the first member, A torsion coil spring according to any one of claims 1 to 6 that provides a biasing force for rotating the first member and the second member, and A fastener for jewelry that includes the following features.

11. First member and A second member rotatably connected to the first member, A torsion coil spring according to any one of claims 1 to 6 that provides a biasing force for rotating the first member and the second member, and An assembly kit for fasteners for jewelry, equipped with [specific features / features].

12. An accessory comprising the fastener for an accessory as described in claim 10.

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