Torsion coil spring and method of manufacturing the same, accessory fastener, method of manufacturing the same, and accessory

Abstract

To provide a torsion coil spring that can suppress reduction of rotational energization forces applied to two members which are rotatably connected to each other.SOLUTION: A torsion coil spring 1 includes: a coil part 12; and a first arm part 13 and a second arm part 14 extending from a first end part 121 and a second end part 122 of the coil part 12. The first arm part 13 includes an insertion part 132 to be inserted into a hole 315 in a first member 31, a first middle part 131, and a first folded part 133. The second arm part 14 includes an engagement part 142 to engage with a step part of a recess 325 provided in the second member 32, a second middle part 141, and a second folded part 134. When viewed from a direction perpendicular to a center line Lc of the coil part 12, the insertion part 132 is folded to the side on which the coil part 12 is located, and the engagement part 142 is folded to the side on which the coil part 12 is located and extends in parallel with the center line Lc.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present invention relates to a torsion coil spring and a manufacturing method thereof, a manufacturing method for a fastener for jewelry, and an jewelry. [Background technology]

[0002] There are various types of fasteners (also called clasps) used to connect linear members (such as chains) in accessories such as necklaces, including pull-ring types, plug-in types, screw types, etc. Also known are fasteners with a rotating structure that realizes an open state and a closed state by two rotatably connected members (see Patent Document 1). [Prior art documents] [Patent documents]

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

[0004] Leaf springs are generally used as a simple elastic means for biasing two rotatably connected members. However, because the fasteners used in accessories are small in size, it is difficult for leaf springs to generate sufficient biasing force. On the other hand, torsion coil springs can generate a larger elastic force than leaf springs of the same size, so torsion coil springs are sometimes used as the elastic means of fasteners.

[0005] When a torsion coil spring is used as a fastener, a rotating shaft (shaft) is usually inserted into a hole in a coil portion formed by winding a wire material into a coil shape. FIG. 10 is a diagram showing a case where a general torsion coil spring is used as a fastener. The fastener shown in FIG. 10 has two members 701, 702 rotatably connected via a shaft 800, and a torsion coil spring 600. The torsion coil spring 600 has a coil portion 603 through which the shaft 800 is inserted, and two arm portions 601, 602 extending from both ends of the coil portion 603. The tip of the arm portion 601 presses against the right end of the inner surface of the member 701, and the tip of the arm portion 602 presses against the left end of the inner surface of the member 702.

[0006] 10, the force F of the two arm parts 601, 602 pushing the two members 701, 702 generates a wasted force that acts to rotate the shaft 800 counterclockwise when viewed from a direction perpendicular to the rotation center line Lr passing through the center of rotation of the shaft 800. While this wasted force does not contribute to the rotation of the members 701, 702 around the rotation center line Lr, it increases friction in the sliding portion between the member 701 or the member 702 and the shaft 800, which reduces the biasing force and reduces the durability of the mechanism related to the rotation.

[0007] The present invention has been made in consideration of the above circumstances, and its objects are to provide a torsion coil spring and a manufacturing method thereof that can suppress a reduction in the rotational biasing force applied to two rotatably connected members, to provide a fastener for jewelry using such a torsion coil spring and a manufacturing method thereof, and to provide jewelry equipped with such a fastener for jewelry. [Means for solving the problem]

[0008] A first aspect of the present invention is a torsion coil spring that generates a biasing force that rotates a first member and a second member that are rotatably connected relative to each other, the torsion coil spring having a coil portion in which wire is wound in a spiral shape, a first arm portion extending from a first end of the coil portion, and a second arm portion extending from a second end of the coil portion, the first arm portion including an insertion portion that is inserted into a hole provided in the first member, a first intermediate portion that connects the first end and the insertion portion, and a first bent portion that is bent between the insertion portion and the first intermediate portion, The arm portion includes an engaging portion that engages with a step portion provided on the second member, a second intermediate portion that connects the second end portion and the engaging portion, and a second bent portion that is bent between the second intermediate portion and the engaging portion, and a coil hole in the center of the coil portion has a circular shape when viewed from a center line direction that is parallel to the center line of the spiral shape, the first end portion is located behind the center line when viewed from a first direction perpendicular to the center line, the second end portion is located behind the center line when viewed from a second direction perpendicular to the center line, and the first intermediate portion is located behind the circular shape of the coil hole when viewed from the center line direction. The insertion portion extends along a first tangent line having a shape similar to that of the first bent portion, and is tangent to a first perpendicular line perpendicular to the center line when viewed from the first direction, and extends in a direction away from the center line as it moves away from the first end portion. When viewed from the center line direction, the insertion portion extends in a direction away from the first tangent line as it moves away from the first bent portion, and in a direction toward an opposite side to the side where the coil hole is located with respect to the first tangent line. When viewed from the first direction, the insertion portion extends in a direction away from the first perpendicular line as it moves away from the first bent portion, and the coil portion is positioned relative to the first perpendicular line. the second intermediate portion extends in a direction toward the side where the coil portion is placed, along a second tangent to the circular shape of the coil hole when viewed from the center line direction, and is tangent to a second perpendicular line perpendicular to the center line when viewed from the second direction, and extends in a direction away from the center line as it moves away from the second end portion; and the engagement portion, when viewed from the second direction, extends in a direction away from the second perpendicular line as it moves away from the second bent portion, and extends parallel to the center line in a direction toward the side where the coil portion is located with respect to the second perpendicular line.

[0009] A second aspect of the present invention is a manufacturing method of the torsion coil spring according to the first aspect, comprising a coil portion forming step of forming a coil portion by spirally winding a wire rod, a first arm portion forming step of forming a first arm portion, and a second arm portion forming step of forming a second arm portion, the first arm portion forming step including a first bending step of bending the wire rod extending from the first end portion at a first bent portion, the second arm portion forming step including a second bending step of bending the wire rod extending from the second end portion at a second bent portion, the first bending step including a step of bending the wire rod extending from the second end portion at a second bent portion, the first bending step including a step of bending the wire rod extending from the second end portion at a second bent portion, the first bending step including a step of bending the wire rod extending from the first ... second end portion at a second bent portion, the first bending step including a step of bending the wire rod extending from the second end portion at a second bent portion, the first bending step including a step of bending the wire rod extending from the second end portion at a second bent portion, the first bending step including a step of bending the wire rod extending from the a second bending step includes bending the wire extending from the second end at the second bend portion so that a portion which becomes an engagement portion extends parallel to the center line in a direction away from the second perpendicular line as it moves away from the second bend portion when viewed from the second direction, and in a direction away from the second perpendicular line as it moves away from the second bend portion when viewed from the second direction, and in a direction toward the side where the coil portion is located relative to the second perpendicular line.

[0010] A third aspect of the present invention is a fastener for jewelry having a first member and a second member rotatably connected, and a torsion coil spring according to the first aspect that generates a biasing force that rotates the first member and the second member relative to one another.

[0011] A fourth aspect of the present invention is a method for manufacturing a fastener for a body ornament, the fastener for the body ornament having a first member and a second member rotatably connected, and a torsion coil spring according to the first aspect described above that generates a biasing force that rotates the first member and the second member relatively, the method comprising the steps of: preparing the torsion coil spring; preparing the first member and the second member rotatably connected; and, while abutting the insertion portion against the first member and the engagement portion against the second member, pushing the torsion coil spring between the first member and the second member until the insertion portion enters the hole of the first member and the engagement portion engages with the stepped portion of the second member.

[0012] A fifth aspect of the present invention is an ornament comprising the fastener for an ornament according to the third aspect. Effect of the Invention

[0013] According to the present invention, it is possible to provide a torsion coil spring and a manufacturing method thereof that can suppress a reduction in the rotational biasing force applied to two rotatably connected components, a fastener for jewelry using such a torsion coil spring and a manufacturing method thereof, and an ornament equipped with such a fastener for jewelry. [Brief description of the drawings]

[0014] [Figure 1] 1A and 1B are diagrams showing an example of a torsion coil spring according to this embodiment. [Diagram 2] 2A to 2C are diagrams showing an example of a torsion coil spring according to this embodiment. [Diagram 3] FIG. 3 is a diagram showing an example in which two rotatably connected members are biased by a torsion coil spring. [Figure 4] Fig. 4A is a diagram showing an example of a piece of jewelry including a fastener according to a second embodiment, and Fig. 4B is a perspective view showing an example of the fastener in an open state. [Diagram 5] Figures 5A and 5B are diagrams showing an example of a first member, and Figures 5C and 5D are diagrams showing an example of a second member. [Figure 6]FIG. 6A is a side view of the fastener, and FIG. 6B is a top view of the fastener. [Figure 7] FIG. 7A is a cross-sectional view showing the internal structure of the fastener, and FIG. 7B is a rear view of the fastener. [Figure 8] Fig. 8A is a flow chart for explaining an example of a method for manufacturing the torsion coil spring according to this embodiment, and Fig. 8B is a flow chart for explaining an example of a procedure for forming the arm portion. [Figure 9] 9A and 9B are diagrams for explaining an example of a method for manufacturing the fastener according to this embodiment. [Figure 10] FIG. 10 is a diagram showing a conventional fastener for jewelry using a torsion coil spring. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0015] <First embodiment> 1A to 1B and 2A to 2C are diagrams showing an example of a torsion coil spring according to this embodiment. The torsion coil spring 1 according to this embodiment is used to generate a biasing force that rotates two rotatably connected members (a first member 21 and a second member 22 described below) relative to one another. As shown in FIGS. 1A and 1B, the torsion coil spring 1 has a coil portion 12 in which a wire 10 is wound in a spiral shape, a first arm portion 13 extending from a first end portion 121 which is one end portion of the coil portion 12, and a second arm portion 14 extending from a second end portion 122 which is the other end portion of the coil portion 12.

[0016] "Dc" in Fig. 1B indicates a direction parallel to the center line Lc of the spiral shape of the coil portion 12 (hereinafter, referred to as "center line direction Dc"). "D1", "D2", and "D3" in Fig. 1A and Fig. 2A respectively indicate directions perpendicular to the center line Lc (hereinafter, "D1", "D2", and "D3" will be referred to as "first direction D1", "second direction D2", and "third direction D3", respectively).

[0017] Fig. 1A and Fig. 2A are views of the torsion coil spring 1 as viewed from the center line direction Dc. Fig. 1B is a view of the torsion coil spring 1 as viewed from a third direction D3. Fig. 2B is a view of the torsion coil spring 1 as viewed from a first direction D1. Fig. 2C is a view of the torsion coil spring 1 as viewed from a second direction D2.

[0018] (Coil section 12) 1B, 2B, and 2C, the coil portion 12 is formed by winding the wire 10 in a spiral shape about three and a half times. In this example, the coil portion 12 is formed by tight winding, but it may be formed by other winding methods that do not tightly wind the wires 10. The central hole of the coil portion 12 (hereinafter, referred to as "coil hole 120") as viewed from the center line direction Dc is substantially circular, as shown in FIG. 1B etc. The center line Lc passes through the center of this circle.

[0019] "Lt1" and "Lt2" in Figs. 1A and 2A indicate tangents to the circular shape of the coil hole 120 when viewed from the center line direction Dc (hereinafter, referred to as "first tangent Lt1" and "second tangent Lt2", respectively).

[0020] (First arm portion 13) 1B and other figures, the first arm portion 13 has an insertion portion 132, a first intermediate portion 131, and a first bent portion 133. The insertion portion 132 is inserted into a hole 215 (FIG. 3) of the first member 21 described below. The first intermediate portion 131 connects the first end portion 121 of the coil portion 12 and the insertion portion 132. The first bent portion 133 is a bent portion between the first intermediate portion 131 and the insertion portion 132.

[0021] The first end 121 of the coil portion 12 connected to the first intermediate portion 131 is located behind the center line Lc when viewed from the first direction D1 as shown in Fig. 2B. The first direction D1 is a direction perpendicular to the center line Lc and is also a direction approximately perpendicular to the first tangent line Lt1 as shown in Fig. 2A.

[0022] 2A, when viewed from the center line direction Dc, the first intermediate portion 131 extends along a first tangent line Lt1 of the circle shape of the coil hole 120. Also, when viewed from the first direction D1, as shown in Fig. 2B, the first intermediate portion 131 is tangent to a perpendicular line Lp1 (hereinafter referred to as "first perpendicular line Lp1") perpendicular to the center line Lc, and extends in a direction away from the center line Lc (upward in Fig. 2A) as it moves away from the first end portion 121.

[0023] As shown in Fig. 2A, the insertion portion 132 extends in a direction away from the first tangent line Lt1 as it moves away from the first bent portion 133, and in a direction toward the opposite side of the first tangent line Lt1 from the side where the coil hole 120 is located (the upper side of the first tangent line Lt1 in Fig. 2A) as viewed from the center line direction Dc. In the example of Fig. 2A, the insertion portion 132 extends along a straight line L1 as viewed from the center line direction Dc.

[0024] 2B, the insertion portion 132 extends in a direction away from the first perpendicular line Lp1 as it moves away from the first bent portion 133, and toward the side of the first perpendicular line Lp1 where the coil portion 12 is located (the left side of the first perpendicular line Lp1 in FIG. 2B) as viewed from the first direction D1. In the example of FIG. 2B, the insertion portion 132 extends along a straight line L2 as viewed from the first direction D1.

[0025] 2A, the first arm portion 13 is bent at the first bent portion 133 so that the first intermediate portion 131 and the insertion portion 132 form an obtuse angle when viewed from the center line direction Dc. That is, when viewed from the center line direction Dc, the angle θ1 (FIG. 2A) between the straight line L1 indicating the extension direction of the insertion portion 132 and the first tangent Lt1 is within a range of approximately greater than 90° and less than 180°.

[0026] 2B, the first arm portion 13 is bent at the first bent portion 133 such that the first intermediate portion 131 and the insertion portion 132 form an obtuse angle when viewed from the first direction D1. That is, when viewed from the first direction D1, the angle θ2 (FIG. 2B) between the straight line L2 indicating the extension direction of the insertion portion 132 and the first perpendicular line Lp1 is within a range of approximately greater than 90° and less than 180°.

[0027] (Second arm portion 14) As shown in FIG. 1B etc., the second arm portion 14 has an engaging portion 142, a second intermediate portion 141, and a second bent portion 134. The engaging portion 142 engages with a step (FIG. 3) of a recess 225 provided in the second member 22 described later. The second intermediate portion 141 connects the second end portion 122 of the coil portion 12 and the engaging portion 142. The second bent portion 134 is a bent portion between the second intermediate portion 141 and the engaging portion 142.

[0028] The second end 122 of the coil portion 12 connected to the second intermediate portion 141 is located behind the center line Lc when viewed from the second direction D2 as shown in Fig. 2C. The second direction D2 is a direction perpendicular to the center line Lc and is also a direction approximately perpendicular to the second tangent line Lt2 as shown in Fig. 2A.

[0029] 2A, when viewed from the center line direction Dc, the second intermediate portion 141 extends along a second tangent line Lt2 of the circle shape of the coil hole 120. Also, when viewed from the second direction D2, as shown in Fig. 2C, the second intermediate portion 141 is tangent to a perpendicular line Lp2 (hereinafter referred to as "second perpendicular line Lp2") perpendicular to the center line Lc, and extends in a direction away from the center line Lc (downward in Fig. 2C) as it moves away from the second end portion 122.

[0030] As shown in FIG. 2C, when viewed from the second direction D2, the engagement portion 142 extends in a direction away from the second perpendicular line Lp2 as it moves away from the second bend portion 134, and extends generally parallel to the center line Lc in a direction toward the side of the second perpendicular line Lp2 where the coil portion 12 is located (to the right of the second perpendicular line Lp2 in FIG. 2C).

[0031] As shown in FIG. 2C, the engagement portion 142 has a length that reaches a perpendicular line Lp3 (hereinafter referred to as a "third perpendicular line Lp3") that passes through the center of the coil portion 12 and is perpendicular to the center line Lc when viewed from the second direction D2.

[0032] As shown in FIG. 2C, the second arm portion 14 is bent at the second bent portion 134 so that the second intermediate portion 141 and the engagement portion 142 form a substantially right angle when viewed in the second direction D2.

[0033] As shown in FIG. 2A, the angle θc between the first tangent Lt1 and the second tangent Lt2 toward the coil hole 120 is an acute angle.

[0034] Fig. 3 is a diagram showing an example in which two rotatably connected members (first member 21, second member 22) are biased by the above-mentioned torsion coil spring 1. The first member 21 and the second member 22 are rotatably connected by two connecting parts 23, and can rotate relatively around the rotation center line Lr. Fig. 3 is a diagram seen from a direction perpendicular to the rotation center line Lr.

[0035] The first member 21 has a hole 215 into which the insertion portion 132 is inserted, and the second member 22 has a recess 225 with a stepped portion formed therein that engages with the engagement portion 142. The torsion coil spring 1 is held between the first member 21 and the second member 22 with the insertion portion 132 inserted and the engagement portion 142 engaged with the stepped portion of the recess 225. In this state, the center line Lc and the rotation center line Lr of the torsion coil spring 1 are approximately parallel to each other.

[0036] The first member 21 has an upper plate portion 210 in which a hole 215 is formed, and two first side plate portions 212 provided at both ends of the upper plate portion 210. The second member 22 has a bottom plate portion 220 in which a recess 225 forming a step portion is provided, and two second side plate portions 222 provided at both ends of the bottom plate portion 220. One first side plate portion 212 and one second side plate portion 222 are connected by one connecting portion 23, and the other first side plate portion 212 and the other second side plate portion 222 are connected by another connecting portion 23. In the example of FIG. 3, the connecting portion 23 includes a protrusion portion 224 provided on the second side plate portion 222 and a connecting hole 214 provided on the first side plate portion 212. The protrusion portion 224 is inserted into the connecting hole 214, and the protrusion portion 224 is rotatable in the connecting hole 214.

[0037] According to this embodiment, as shown in Fig. 2B, when viewed from the first direction D1, the insertion portion 132 extends in a direction away from the first perpendicular line Lp1 as it moves away from the first bent portion 133, and in a direction toward the side where the coil portion 12 is located with respect to the first perpendicular line Lp1. Also, as shown in Fig. 2C, when viewed from the second direction D2, the engagement portion 142 extends in a direction away from the second perpendicular line Lp2 as it moves away from the second bent portion 134, and in a direction toward the side where the coil portion 12 is located with respect to the second perpendicular line Lp2. That is, as shown in Fig. 1B, the positions of the insertion portion 132 and the engagement portion 142 are closer to the center of the coil portion 12 as viewed from a direction perpendicular to the center line Lc, compared to the arm portions 601 and 602 in the conventional torsion coil spring 600 shown in Fig. 10. As a result, when the torsion coil spring 1 is disposed between the first member 21 and the first member 21 so that the center line Lc of the coil portion 12 and the rotation center line Lr are parallel, the direction of the urging force acting on the first member 21 and the first member 21 by the insertion portion 132 and the engagement portion 142 approaches a direction perpendicular to the rotation center line Lr, compared to the conventional torsion coil spring 600 shown in FIG. 10. As the urging force of the torsion coil spring 1 approaches a direction perpendicular to the rotation center line Lr, the unnecessary force (the force that does not contribute to the rotation of the first member 21 and the second member 22 around the rotation center line Lr) that acts to shift the rotation center of the two connecting portions 23 from the rotation center line Lr becomes smaller, and the friction in the sliding portion of the connecting portion 23 (the sliding portion between the protrusion portion 224 and the connecting hole 214) becomes smaller. Therefore, it is possible to effectively suppress the reduction in the rotation urging force applied to the first member 21 and the second member 22. Furthermore, since unnecessary force applied to the connecting portion 23 is reduced, deterioration in durability can be suppressed.

[0038] According to this embodiment, as shown in FIG. 3, the insertion portion 132 of the first arm portion 13 is inserted into the hole 215 of the first member 21, and the engagement portion 142 of the second arm portion 14 engages with a step portion formed in the recess 225 of the second member 22. Therefore, even if the shaft of the rotating shaft is not inserted into the coil portion 12 as shown in FIG. 10, the torsion coil spring 1 is unlikely to come off the first member 21 and the second member 22. In addition, since the second arm portion 14 is held on the second member 22 by the engagement between the engagement portion 142 of the second arm portion 14 and the step portion of the second member 22, the second arm portion 14 becomes easy to attach to the second member 22. This makes it possible to easily attach each arm portion of the torsion coil spring 1 to the first member 21 and the second member 22.

[0039] 2A, when viewed from the center line direction Dc, the insertion portion 132 extends in a direction away from the first tangent line Lt1 as it moves away from the first bent portion 133, and in a direction toward the opposite side of the first tangent line Lt1 to the side where the coil hole 120 is located. This makes it possible to easily insert the insertion portion 132 into the hole 215 of the first member 21 when the torsion coil spring 1 is disposed between the first member 21 and the first member 21. Furthermore, at the first bent portion 133 of the first arm portion 13, the first intermediate portion 131 and the insertion portion 132 are bent so as to form an obtuse angle when viewed from both the center line direction Dc and the first direction D1 (FIGS. 2A and 2B). Therefore, compared to when these angles are acute angles, it is possible to make it easier to insert the insertion portion 132 into the hole 215 of the first member 21.

[0040] According to this embodiment, as shown in Fig. 2C, the engaging portion 142 extends parallel to the center line Lc when viewed from the second direction D2. Therefore, when the torsion coil spring 1 is disposed between the second member 22 and the first member 21, in which the step portion of the recess 225 extends parallel to the rotation center line Lr, so that the center line Lc and the rotation center line Lr are parallel, the engaging portion 142 extending parallel to the center line Lc engages with the step portion of the recess 225 extending parallel to the rotation center line Lr. As a result, when the first member 21 and the second member 22 rotate around the rotation center line Lr, the step portion of the recess 225 and the engaging portion 142 are kept parallel to each other, so that the engagement between them is unlikely to be released.

[0041] According to this embodiment, as shown in Fig. 2C, when viewed from the second direction D2, the second intermediate portion 141 and the engagement portion 142 are bent at a right angle at the second bent portion 134. This makes it possible to reduce the width of the torsion coil spring 1 in the center line direction Dc, compared to a conventional torsion coil spring as shown in Fig. 10.

[0042] 2C, when viewed from the second direction D2, the engagement portion 142 has a length that reaches the third perpendicular line Lp3 (a perpendicular line that passes through the center of the coil portion 12 and is perpendicular to the center line Lc). This allows the force pressing the second member 22 by the engagement portion 142 to be applied up to the position of the third perpendicular line Lp3 (near the center of the coil portion 12), so that the direction of the biasing force acting on the first member 21 and the first member 21 can be made closer to a direction perpendicular to the rotation center line Lr.

[0043] 2A , the angle between the first tangent Lt1 and the second tangent Lt2 toward the coil hole 120 is an acute angle. As a result, when inserting the torsion coil spring 1 between the first member 21 and the second member 22, the first arm portion 13 and the first arm portion 13 are less likely to get in the way, making it easier to perform the assembly work of attaching the arms of the torsion coil spring 1 to the first member 21 and the second member 22.

[0044] 3, one first side plate portion 212 and one second side plate portion 222 are connected by one connecting portion 23, and the other first side plate portion 212 and the other second side plate portion 222 are connected by another connecting portion 23. Furthermore, at least a part of the torsion coil spring 1 is located between the two first side plate portions 212 of the first member 21 and is also located between the two second side plate portions 222 of the second member 22. This makes it easier to combine the first member 21 and the second member 22 with the torsion coil spring 1 than in the structure shown in FIG. 10 in which the shaft 800 is inserted into the coil portion 603.

[0045] <Second embodiment> Next, a second embodiment of the present invention will be described. The second embodiment relates to a fastener for an ornament that uses the above-mentioned torsion coil spring 1 (FIGS. 1A to 1B, 2A to 2C) as biasing means.

[0046] Fig. 4A is a diagram showing an example of an accessory 5 including a fastener 3 using the torsion coil spring 1 according to this embodiment. The accessory 5 shown in Fig. 4A is, for example, a necklace or a bracelet, and includes separate linear members 4A and 4B and a fastener 3 that connects them in a ring shape. Fig. 4B shows the fastener 3 in an open state.

[0047] As shown in Figures 4A and 4B, the fastener 3 has a first member 31 and a second member 32 that are rotatably connected, two connecting portions 33 that connect the first member 31 and the second member 32, and an operating portion 313 used to rotate the first member 31 and the second member 32.

[0048] 5A shows a side view of the first member 31, and FIG. 5B shows a plan view of the first member 31. As shown in FIGS. 5A and 5B, the first member 31 has a front end 311 bent like a hook when viewed from the side, an upper plate 310 extending from the upper surface side of the front end 311 to the rear side, and two first side plate portions 312 extending from the side surfaces of the front end 311 to the rear side. The two first side plate portions 312 extend downward from the left and right side ends of the upper plate portion 310. A hole 315 into which the insertion portion 132 of the torsion coil spring 1 is inserted is formed at the end on the rear side of the upper plate portion 310.

[0049] The operation unit 313 is provided on the rear side of the outer surface of the upper plate portion 310. As shown in FIG. 5B, on the outer surface of the upper plate portion 310 seen along the penetration direction of the hole 315, the operation unit 313 covers an area including the hole 315. In addition, as shown in FIG. 7A and FIG. 7B described later, the operation unit 313 can also cover an area including the insertion portion 132 protruding from the hole 315. In the example of FIG. 5A, the operation unit 313 extends from the end on the rear side of the upper plate portion 310 and is formed of a plate-like member that is curved toward the front side. The operation unit 313 is curved into a ring shape when viewed from the side, and covers the upper side of the hole 315 formed in the upper plate portion 310.

[0050] A connection hole 314 is formed in each of the two first side plate portions 312 of the first member 31. A protrusion 324 of the second member 32, which will be described later, is inserted into the connection hole 314.

[0051] 5C shows a side view of the second member 32, and FIG. 5D shows a plan view of the second member 32. As shown in FIG. 5C and FIG. 5D, the second member 32 has a front end 321 bent like a hook when viewed from the side, a bottom plate portion 320 extending from the bottom side of the front end 321 to the rear side, two second side plate portions 322 extending from the side sides of the front end 321 to the rear side, and an attachment portion 323 provided at the end of the rear side of the bottom plate portion 320. The two second side plate portions 322 extend upward from the left and right side ends of the bottom plate portion 320. The attachment portion 323 has an attachment hole 326 for attaching the ring member 42 at the end of the linear member 4B.

[0052] The two second side plate portions 322 of the second member 32 each have a protrusion 324 protruding outward. The two protrusions 324 are each inserted into a connecting hole 314 of the first side plate portion 312. One connecting hole 314 and one protrusion 324 inserted therein constitute one connecting portion 33. The first member 31 and the second member 32 are connected by the two connecting portions 33 (connecting holes 314, protrusions 324) to be rotatable around the rotation center line Lr (FIG. 6B).

[0053] 5D, a recess 325 is formed on the inner surface (the surface facing the first member 31) of the bottom plate portion 320 of the second member 32. The recess 325 has steps 325a and 325b extending parallel to the rotation center line Lr (FIG. 6B) of the two connecting portions 33. The steps 325a and 325b engage with the engaging portion 142 of the torsion coil spring 1.

[0054] FIG. 6A shows a side view of the fastener 3, and FIG. 6B shows a plan view of the fastener 3. FIG. 7A shows a cross-sectional view showing the internal structure of the fastener 3, and FIG. 7B shows a rear view of the fastener 3. When the fastener 3 is closed, the front end 311 of the first member 31 and the front end 321 of the second member 32 come into contact with each other, and as shown in FIG. 6A, a closed space 30 surrounded by the first member 31 and the second member 32 is formed. When the fastener 3 is opened, as shown in FIG. 4B, a gap is formed between the front end 311 and the front end 321, and the ring member 41 can enter and exit the closed space 30 through this gap. When the fastener 3 is connected to the ring member 41 of the linear member 4A as shown in FIG. 4A, the fastener 3 is opened, and the ring member 41 is hooked on the front end 321 bent like a hook, and the fastener 3 is closed. As a result, the ring member 41 is inserted into the closed space 30 and cannot escape from the closed space. To remove the fastener 3 from the ring member 41, the fastener 3 is opened, and the ring member 41 is removed from the gap between the front end 311 and the front end 321, and the fastener 3 is closed.

[0055] The first member 31 and the second member 32 are biased by the elastic force of the torsion coil spring 1 so as to rotate relatively in the direction toward the closed state. When the first member 31 and the second member 32 are changed from the closed state to the open state, a force is applied by placing a finger or the like on an operating portion 313 provided on the first member 31, and the first member 31 and the second member 32 are rotated relatively against the biasing force of the torsion coil spring 1. When the force applied to the operating portion 313 is released, the first member 31 and the second member 32 automatically return to the closed state.

[0056] 7A and 7B, the torsion coil spring 1 is disposed in the space inside the fastener 3 (the space surrounded by the first member 31 and the second member 32) with the insertion portion 132 inserted into the hole 315 of the first member 31 and the engagement portion 142 engaged with the steps 325a, 325b of the recess 325 of the second member 32. At least a portion of the torsion coil spring 1 (a portion including the coil portion 12 in the illustrated example) is located between the two first side plate portions 312 and between the two second side plate portions 322. The center line Lc of the coil portion 12 of the torsion coil spring 1 is approximately parallel to the rotation center line Lr (FIG. 6B).

[0057] According to this embodiment, similarly to the first embodiment (FIG. 3), the torsion coil spring 1 is disposed inside the first member 31 and the second member 32 so that the center line Lc of the coil portion 12 and the rotation center line Lr are parallel (FIG. 7B), and the direction of the biasing force acting on the first member 31 and the second member 32 by the insertion portion 132 and the engagement portion 142 approaches a direction perpendicular to the rotation center line Lr compared to the conventional torsion coil spring 600 shown in FIG. 10. Therefore, it is possible to effectively prevent the rotational biasing force applied to the first member 31 and the second member 32 from being reduced. In addition, since the unnecessary force acting on the connecting portion 33 is reduced, it is possible to prevent a decrease in durability.

[0058] According to this embodiment, on the outer surface of the first member 31 seen along the penetration direction of the hole 315, a range including the hole 315 and a range including the insertion portion 132 protruding from the hole 315 are covered by the operation portion 313 (FIGS. 7A and 7B). As a result, the operation portion 313 can perform the function of preventing the insertion portion 132 protruding from the hole 315 from coming into contact with a finger or other object, in addition to the original function of making it easier to rotate the first member 31 and the second member 32 with a finger or the like. Therefore, the configuration of the fastener 3 can be simplified compared to the case where a separate member for preventing contact with the insertion portion 132 is provided.

[0059] 7A and 7B, the insertion portion 132 of the first arm portion 13 is inserted into the hole 315 of the first member 31, and the engagement portion 142 of the second arm portion 14 engages with the stepped portions 325a, 325b formed in the recess 325 of the second member 32. Therefore, even if the shaft of the rotating shaft is not inserted into the coil portion 12 as shown in FIG. 10, the torsion coil spring 1 is unlikely to come off the first member 31 and the second member 32. In addition, the second arm portion 14 is held by the second member 32 by the engagement between the engagement portion 142 of the second arm portion 14 and the stepped portions 325a, 325b of the second member 32, so that each arm portion of the torsion coil spring 1 can be easily attached to the first member 31 and the second member 32.

[0060] According to this embodiment, as shown in Fig. 5D and Fig. 6B, the step portions 325a, 325b of the second member 32 extend parallel to the rotation center line Lr, and as shown in Fig. 7A and Fig. 7B, the torsion coil spring 1 is disposed between the first member 31 and the second member 32 so that the center line Lc and the rotation center line Lr are parallel to each other. Also, as shown in Fig. 2C, the engagement portion 142 extends parallel to the center line Lc when viewed from the second direction D2. Therefore, when the first member 21 and the second member 22 rotate around the rotation center line Lr, the step portions 325a, 325b of the second member 32 and the engagement portion 142 are kept parallel to each other, so that the engagement between them is unlikely to be released.

[0061] 6B and 7B, one first side plate portion 312 and one second side plate portion 322 are connected by one connecting portion 33, and the other first side plate portion 312 and the other second side plate portion 322 are connected by another connecting portion 33. Furthermore, at least a part of the torsion coil spring 1 is located between the two first side plate portions 212 of the first member 21 and is also located between the two second side plate portions 222 of the second member 22. This makes it easier to combine the first member 31 and the second member 32 with the torsion coil spring 1 than the structure shown in FIG. 10 in which the shaft 800 is inserted into the coil portion 603.

[0062] Next, a method for manufacturing the above-described torsion coil spring 1 according to this embodiment will be described.

[0063] Fig. 8A is a flow chart for explaining an example of a manufacturing method of the torsion coil spring 1. In the manufacturing method shown in Fig. 8A, first, the coil portion 12 is formed by spirally winding the wire 10 (ST100). Next, the first arm portion 13 and the second arm portion 14 extending from the first end portion 121 and the second end portion 122 of the coil portion 12 are formed, respectively (ST105).

[0064] FIG. 8B is a flow chart for illustrating an example of the step of forming first arm portion 13 and second arm portion 14 (ST105: FIG. 8A).

[0065] ST200: The step of forming the first arm portion 13 includes a step of bending the wire 10 extending from the first end portion 121 of the coil portion 12 at a first bent portion 133 (a first bending step). In this first bending process, the wire 10 extending from the first end 121 is bent at the first bent portion 133 so that the portion that becomes the insertion portion 132 extends in a direction away from the first tangent Lt1 as it moves away from the first bent portion 133, as viewed from the center line direction Dc, and in a direction toward the opposite side of the side where the coil hole 120 is located with respect to the first tangent Lt1, as shown in Fig. 2A. Also, in the first bending process, the wire 10 extending from the first end 121 is bent at the first bent portion 133 so that the portion that becomes the insertion portion 132 extends in a direction away from the first perpendicular line Lp1 as it moves away from the first bent portion 133, as viewed from the first direction D1, and in a direction toward the side where the coil portion 12 is located with respect to the first perpendicular line Lp1, as shown in Fig. 2B.

[0066] ST205: The step of forming the second arm portion 14 includes a step of bending the wire 10 extending from the second end 122 of the coil portion 12 at the second bent portion 134 (a second bending step). In this second bending process, the wire 10 extending from the second end 122 is bent at the second bending portion 134 so that the portion that becomes the engagement portion 142 extends parallel to the center line Lc in a direction away from the second perpendicular line Lp2 as it moves away from the second bending portion 134, as shown in FIG. 2C, and in a direction toward the side where the coil portion 12 is located relative to the second perpendicular line Lp2.

[0067] The order of the first bending step in step ST200 and the second bending step in step ST205 may be reversed, or these steps may be performed in parallel. Furthermore, each step of the above-described method for manufacturing the torsion coil spring 1 may be performed manually, or at least some of the steps may be performed using a machine tool.

[0068] Next, a method for manufacturing the fastener 3 using the above-described torsion coil spring 1 according to this embodiment will be described.

[0069] In the manufacturing method of this fastener 3, first, the above-mentioned torsion coil spring 1 is prepared. The torsion coil spring 1 can be produced, for example, by the method shown in Figures 8A and 8B.

[0070] In this manufacturing method, a first member 31 and a second member 32 that are rotatably connected are prepared. For example, the first member 31 (FIGS. 5A and 5B) and the second member 32 (FIGS. 5C and 5D) are produced by press working or the like. The first member 31 and the second member 32 are assembled in a rotatably connected state by inserting two protrusions 324 of the second member 32 into two connecting holes 314 of the first member 31, respectively, as shown in FIG. 9A.

[0071] Next, the torsion coil spring 1 is attached to the first member 31 and the second member 32 which are rotatably connected. That is, while the insertion portion 132 is abutted against the first member 31 and the engagement portion 142 is abutted against the second member 32, the torsion coil spring 1 is pushed between the first member 31 and the second member 32 until the insertion portion 132 enters the hole 315 of the first member 31 and the engagement portion 142 engages with the stepped portions 325a, 325b of the second member 32. For example, as shown in FIG. 9B, the torsion coil spring 1 is pushed from an opening formed on the back side of the connected first member 31 and second member 32 toward the inside of the first member 31 and the second member 32. The elastic force of the torsion coil spring 1 generates a strong force that inserts the insertion portion 132 into the hole 315 of the first member 31, and a strong force that engages the engagement portion 142 with the step portions 325a, 325b of the second member 32, so that the torsion coil spring 1 becomes firmly attached to the first member 31 and the second member 32 and does not easily come off.

[0072] The above-described embodiment is merely an example, and the present embodiment further includes various modifications.

[0073] For example, in the torsion coil spring of this embodiment, the number of turns of the wire in the coil portion, the thickness of the wire, the cross-sectional shape of the wire, the ratio of the outer diameter to the inner diameter of the coil portion, the bending positions of the arm portion as viewed from each direction, the lengths of each straight portion of the arm portion as viewed from each direction, the bending angles of each straight portion of the arm portion as viewed from each direction, the angles formed by the straight portions of the two arm portions, etc. are not limited to the examples shown in Figures 1A to 1B and Figures 2A to 2C, etc.

[0074] The fastener 3 for the ornament shown in Figures 6A to 6B and 7A to 7B is a finished assembled product, but this embodiment is not limited to these examples. That is, this embodiment also includes an assembly set for assembling the fastener for the ornament. The assembly set for the fastener 3 for the ornament shown in Figures 6A to 6B and 7A to 7B has a first member 31 and a second member 32, and a torsion coil spring 1 as a biasing member.

[0075] Furthermore, the torsion coil spring according to the present embodiment is not limited to fasteners for accessories, but can be applied to various instruments and the like, and is particularly useful for instruments and the like that require miniaturization. [Explanation of symbols]

[0076] 1...torsion coil spring, 10...wire rod, 12...coil portion, 120...coil hole, 121...first end portion, 122...second end portion, 13...first arm portion, 131...first intermediate portion, 132...insertion portion, 133...first bent portion, 14...second arm portion, 141...second intermediate portion, 142...engagement portion, 143...second bent portion, 21...first member, 210...upper plate portion, 212...first side plate portion, 214...connection hole, 215...hole, 22...second member, 220...bottom plate portion, 222...second side plate portion, 224...projection portion, 225...recess, 23...connection portion, 3...fastener, 31...first member, 310...upper plate portion, 31 1...front end, 312...first side plate portion, 313...operation portion, 314...connection hole, 315...hole, 32...second member, 320...bottom plate portion, 321...front end, 322...second side plate portion, 323...mounting portion, 324...projection portion, 325...recessed portion, 325a, 325b...step portion, 33...connection portion, 4A...linear member, 4B...linear member, 41, 41...ring member, 5...accessory, Dc...center line direction, D1...first direction, D2...second direction, D3...third direction, Lc...center line, Lt1...first tangent, Lt2...second tangent, Lp1...first perpendicular line, Lp2...second perpendicular line, Lp3...third perpendicular line, Lr...rotation center line

Claims

1. A torsion coil spring that generates a biasing force that relatively rotates a first member and a second member that are rotatably connected to each other, A coil portion in which a wire is wound in a spiral shape; A first arm portion extending from a first end of the coil portion; a second arm portion extending from a second end of the coil portion, The first arm portion is an insertion portion that is inserted into a hole provided in the first member; a first intermediate portion connecting the first end portion and the insertion portion; a first bent portion bent between the insertion portion and the first intermediate portion; Including, The second arm portion is an engaging portion that engages with a stepped portion provided on the second member; a second intermediate portion connecting the second end portion and the engagement portion; a second bent portion bent between the second intermediate portion and the engagement portion; Including, a coil hole at the center of the coil portion has a circular shape when viewed from a center line direction parallel to a center line of the spiral shape, The first end is located behind the center line when viewed in a first direction perpendicular to the center line, the second end is located behind the center line when viewed in a second direction perpendicular to the center line; The first intermediate portion is When viewed from the center line direction, the coil hole extends along a first tangent to the circular shape of the coil hole, When viewed from the first direction, the first end portion is tangent to a first perpendicular line perpendicular to the center line, and extends in a direction away from the center line as it moves away from the first end portion, The insertion portion is as viewed from the center line direction, the direction away from the first tangent line as the direction away from the first bent portion increases, and the direction toward the opposite side to the side where the coil hole is located with respect to the first tangent line, When viewed from the first direction, the direction away from the first perpendicular line as the direction away from the first bent portion and the direction toward the side where the coil portion is located with respect to the first perpendicular line, The second intermediate portion is When viewed from the center line direction, the coil hole extends along a second tangent to the circular shape of the coil hole, When viewed from the second direction, the second end portion is tangent to a second perpendicular line perpendicular to the center line, and extends in a direction away from the center line as it moves away from the second end portion, When viewed from the second direction, the engagement portion extends in a direction away from the second perpendicular line as the engagement portion moves away from the second bent portion, and in a direction toward a side where the coil portion is located with respect to the second perpendicular line, parallel to the center line. Torsion coil spring.

2. The first arm portion is bent at the first bent portion such that the first intermediate portion and the insertion portion form an obtuse angle when viewed from each of the center line direction and the first direction. The torsion coil spring according to claim 1 .

3. The second arm portion is bent at the second bent portion such that the second intermediate portion and the engagement portion form a right angle when viewed from the second direction. The torsion coil spring according to claim 1 .

4. the engagement portion has a length that passes through a center of the coil portion and reaches a third perpendicular line perpendicular to the center line when viewed from the second direction. The torsion coil spring according to claim 1 .

5. an angle between the first tangent line and the second tangent line toward the coil hole is an acute angle; The torsion coil spring according to claim 1 .

6. A method for manufacturing a torsion coil spring according to any one of claims 1 to 5, a coil portion forming step of forming the coil portion by winding the wire in a spiral shape; a first arm portion forming step of forming the first arm portion; and forming the second arm portion. the first arm portion forming step includes a first bending step of bending the wire extending from the first end portion at the first bending portion, the second arm portion forming step includes a second bending step of bending the wire extending from the second end portion at the second bending portion, the first bending process includes bending the wire extending from the first end at the first bent portion so that the portion to become the insertion portion extends in a direction away from the first tangent as it moves away from the first bent portion, toward a side opposite to the side where the coil hole is located with respect to the first tangent, as viewed from the center line direction, and extends in a direction away from the first perpendicular line as it moves away from the first bent portion, toward a side where the coil portion is located with respect to the first perpendicular line, as viewed from the first direction; the second bending step includes bending the wire extending from the second end portion at the second bending portion so that the portion that becomes the engagement portion extends parallel to the center line in a direction that moves away from the second perpendicular line as it moves away from the second bending portion, as viewed from the second direction, and toward a side where the coil portion is located with respect to the second perpendicular line. Manufacturing method of torsion coil springs.

7. A first member and a second member that are rotatably connected to each other; A torsion coil spring according to any one of claims 1 to 5, which generates a biasing force that rotates the first member and the second member relatively. A fastener for jewelry having the following features.

8. The first member and the second member are relatively rotatable around a rotation center line, The center line of the torsion coil spring and the center line of rotation are parallel to each other. The fastener for jewelry according to claim 7.

9. The first member and the second member are rotatably connected to each other via two connecting portions, The first member includes two opposing first side plate portions, The second member includes two opposing second side plate portions, one of the first side plate portions and one of the second side plate portions are connected by one of the connecting portions, the other first side plate portion and the other second side plate portion are connected to each other by another connecting portion, At least a portion of the torsion coil spring is located between the two first side plate portions and between the two second side plate portions. The fastener for jewelry according to claim 7.

10. an operating portion provided on an outer surface of the first member and used for an operation of rotating the first member relatively to the second member; The operation portion covers an area including at least the hole and the insertion portion protruding from the hole on the outer surface of the first member as viewed along the penetrating direction of the hole. The fastener for jewelry according to claim 7.

11. A method for manufacturing a fastener for an ornament, comprising the steps of: The fastener for the accessory is A first member and a second member that are rotatably connected to each other; a torsion coil spring according to any one of claims 1 to 5 that generates a biasing force that rotates the first member and the second member relatively; preparing the torsion coil spring; providing the first member and the second member rotatably coupled; a step of pushing the torsion coil spring between the first member and the second member while bringing the insertion portion into contact with the first member and bringing the engagement portion into contact with the second member, until the insertion portion enters the hole of the first member and the engagement portion engages with the step portion of the second member; A method for manufacturing a fastener for an ornament having the above structure.

12. An ornament comprising the fastener for an ornament according to claim 7.

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