socket

Abstract

The present invention provides a socket with substantially a one-piece structure wherein elastic engaging parts are not susceptible to external forces. The socket (1, 1A) is made of metal and capable of engaging with and disengaging from a stud (60). The socket (1, 1A) is provided with: a circular bottom part (10); a circumferential side part (30) that extends continuously from the radially outward edge of the bottom part (10) in one axial direction; multiple elastic engaging parts (20, 20A) that extend continuously from the bottom part (10); and a cover part (40) that extends continuously from the circumferential side part (30) in the radially inward direction and, with a radially inward edge (41), delimits an opening (42) for accepting the engaging protrusion (62) of the stud (60). A portion of each of the multiple elastic engaging parts (20, 20A) is radially to the outside of the radially inward edge (41) of the cover part (40) and the rest of each of the multiple elastic engaging parts (20, 20A) other than the aforementioned portion is radially to the inside of the radially inward edge (41) of the cover part (40). The bottom part (10), the circumferential side part (30), the multiple elastic engaging parts (20, 20A) and the cover part (40) are formed from a single metal member.

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention relates to sockets, and more particularly to metallic sockets adapted for engaging and disengaging with studs. [Background technology]

[0002] Snap buttons consist of a socket (female snap button) and a stud (male snap button) that can be engaged and disengaged with each other, and are widely used in clothing, bags, and the like. While metal sockets typically have a two-component configuration consisting of a socket shell and a ring, one-piece metal sockets such as the one shown below are also known. Japanese Patent Publication No. 4989520 (Patent Document 1) and Japanese Patent Publication No. 5959515 (Patent Document 2) disclose one-piece sockets formed by drawing a single metal plate. These sockets have multiple elastic engagement portions (spring portions) formed by cutting and bending portions of the socket body. These elastic engagement portions are temporarily deflected radially outward by the engaging protrusions of the stud when the stud is engaged with or disengaged from the socket. One-piece metal sockets have the advantage of reducing material and assembly costs compared to two-component sockets.

[0003] However, in the sockets described in Patent Documents 1 and 2, the elastic engagement portion, particularly the tip end, is substantially exposed to the outside, and therefore the elastic engagement portion is susceptible to external forces when it comes into contact with external objects when the socket is stored, transported, attached to fabric such as clothing, or used, which may result in deformation and loss of flexibility.

[0004] In contrast to the sockets described in Patent Documents 1 and 2, the socket described in Japanese Utility Model Laid-Open Publication No. 59-174015 (Patent Document 3) has a configuration in which a portion of the elastic engagement portion is covered by a cover member, making the elastic engagement portion less susceptible to external forces. However, the socket in Patent Document 3 has a two-component configuration, combining a stud body and a cover member, which results in higher material and assembly costs compared to a one-piece socket. Furthermore, with a two-component configuration, the components may disintegrate over time, and foreign matter may get into the gaps between the components. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 4989520 [Patent Document 2] Patent No. 5959515 [Patent Document 3] Japanese Utility Model Application Publication No. 59-174015 Summary of the Invention [Problem to be solved by the invention]

[0006] SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a socket that is substantially of a one-piece construction and in which the elastic engagement portion is less susceptible to external forces. [Means for solving the problem]

[0007] In order to solve the above problems, according to the present invention, there is provided a metal socket that can engage and disengage with a stud, comprising a circular bottom, a peripheral side portion that extends continuously in one axial direction from the radially outer end of the bottom, a plurality of elastic engagement portions that extend continuously from the bottom, and a cover portion that extends continuously radially inward from the peripheral side portion and defines an opening at its radially inner end that receives an engagement protrusion of the stud, wherein a portion of each of the plurality of elastic engagement portions is radially outer than the radially inner end of the cover portion, and the remaining portions of each of the plurality of elastic engagement portions are radially inner than the radially inner end of the cover portion.

[0008] According to the present invention, a portion of each elastic engagement portion is located radially outward of the radially inner end of the cover portion and is substantially covered by the cover portion, making each elastic engagement portion less susceptible to external forces. Furthermore, in the present invention, "continuously extending" means that the metal material of a certain portion (e.g., the bottom portion) continues to extend to form another portion (e.g., the elastic engagement portions or the circumferential side portion), and does not mean that another portion is formed by adding a separate member to a certain portion. Therefore, in the present invention, the metal material forming the bottom portion and the metal material forming the circumferential side portion and each elastic engagement portion are continuous and integrated, and the circumferential side portion and each elastic engagement portion are not formed by adding a separate member to the bottom portion. Similarly, the metal material forming the circumferential side portion and the metal material forming the cover portion are continuous and integrated, and the cover portion is not formed by adding a separate member to the circumferential side portion. Furthermore, in the present invention, the bottom portion, the circumferential side portion, the multiple elastic engagement portions, and the cover portion are formed from a single metal part. Therefore, the socket itself is a one-piece structure, and the socket itself is not formed by combining two or more parts.

[0009] In the present invention, the socket is made of a metal such as aluminum, an aluminum alloy, copper, a copper alloy, or stainless steel.

[0010] In one embodiment of the present invention, the plurality of elastic engagement portions include a base portion connected to the bottom portion and a bulging portion extending from the base portion in one axial direction and bulging radially inward, the bulging portion including an engagement end located at the radially innermost position of the bulging portion and a tip end located at the end opposite the base portion, the portion of each of the plurality of elastic engagement portions including the tip end, and the other portion of each of the plurality of elastic engagement portions including the engagement end. In this embodiment, the tip end of each elastic engagement portion is located radially outward from the radially inner end of the cover portion and is substantially covered by the cover portion. This reduces or eliminates the risk of the tip end of each elastic engagement portion being subjected to external force from an external object, etc.

[0011] In one embodiment of the present invention, the portion of each of the plurality of elastic engagement portions includes the base. In this embodiment, the base of each elastic engagement portion is located radially outward from the radially inner end of the cover portion and is substantially covered by the cover portion. This reduces or eliminates the possibility of the base of each elastic engagement portion being subjected to external force from an external object or the like.

[0012] In one embodiment of the present invention, the bases of the plurality of elastic engagement parts include thinned portions formed by partially compressing the thickness of the bases of the elastic engagement parts. By forming the thinned portions at the bases of the elastic engagement parts, the metal material of the bases hardens at the thinned portions, increasing the strength of the bases and thereby enabling the flexibility of the elastic engagement parts to be maintained over the medium to long term.

[0013] In one embodiment of the present invention, the multiple elastic engagement portions are formed by partially cutting and bending the bottom portion, and the bottom portion includes a cutout portion corresponding to each of the multiple elastic engagement portions. In another embodiment, the bottom portion includes a rib portion provided between each pair of circumferentially adjacent cutout portions. In this embodiment, the rib portion can compensate for the reduction in strength of the bottom portion due to the cutout portions. Furthermore, because the rib portion digs into the fabric when the socket is attached to the fabric, it is possible to reduce or eliminate, over the medium to long term, rotation of the socket relative to the shaft portion of the attachment member. [Effects of the Invention]

[0014] In the present invention, a portion of each elastic engagement portion is located radially outward of the radially inner end of the cover portion and is substantially covered by the cover portion, making each elastic engagement portion less susceptible to external forces. Furthermore, the metal material forming the bottom portion is continuous and integral with the metal material forming the peripheral side portion and each elastic engagement portion, and similarly, the metal material forming the peripheral side portion is continuous and integral with the metal material forming the cover portion. Therefore, the socket itself has a one-piece structure in which the bottom portion, peripheral side portion, multiple elastic engagement portions, and cover portion are formed from a single metal component. This reduces material and assembly costs compared to sockets consisting of two components, while reducing or eliminating the risk of loss of flexibility of the elastic engagement portions. Furthermore, there is no risk of the components disintegrating over time or foreign matter entering the gaps between the components, as occurs with sockets consisting of two components. In particular, the one-piece structure including the cover portion in the present invention is extremely advantageous, as the cover portion protects each elastic engagement portion from external forces while preventing the cover portion, which is susceptible to external forces, from separating from the peripheral side portion. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a top view of a socket according to a first embodiment of the present invention. [Figure 2] FIG. 2 is a bottom view of the socket of FIG. [Figure 3] FIG. 3 is a side view of the socket of FIG. [Figure 4] 4 is a cross-sectional view of the socket taken along line AA in FIG. [Figure 5] FIG. 5 is a perspective view of the socket taken along line AA in FIG. [Figure 6] FIG. 6 is a cross-sectional view showing a state in which the socket is attached to the fabric of clothing or the like by the attachment member. [Figure 7] FIG. 7 is a cross-sectional view showing a state in which a stud (male snap button) is attached to a fabric by an attachment member. [Figure 8] FIG. 8 is a cross-sectional view showing the connection state between the socket and the stud. [Figure 9]FIG. 9 is a bottom view showing a modified example of the socket of the first embodiment. [Figure 10] 10 is a cross-sectional view of the socket of FIG. 9 taken along the arrows similar to FIG. [Figure 11] 11 is a cutaway perspective view similar to FIG. 5 of the socket of FIG. [Figure 12] FIG. 12 is a top view of a socket according to a second embodiment of the present invention. [Figure 13] FIG. 13 is a bottom view of the socket of FIG. [Figure 14] 14 is a cross-sectional view of the socket taken along line BB in FIG. 12. FIG. [Figure 15] 15 is a perspective view of the socket taken along line BB in FIG. 12. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Several embodiments of the present invention will be described below with reference to the drawings. However, the present invention is not limited to such embodiments and can be modified as appropriate within the scope of the claims and their equivalents. Figures 1, 2, and 3 are top, bottom, and side views of a socket (female snap button) 1 according to a first embodiment of the present invention. Figure 4 is a cross-sectional view of the socket 1 taken along line AA in Figure 1. Figure 5 is a perspective view of the socket 1 cut along line AA in Figure 1. In the following description of the socket 1 (1A, 101), the up-down direction will be based on the paper plane of Figures 4, 10, and 14 unless otherwise specified. The socket 1 is a one-piece structure formed by drawing a single metal plate, and is not formed by combining two or more parts. The socket 1 includes a circular plate-shaped bottom portion 10, five elastic engagement portions 20 (for example) extending continuously upward from the bottom portion 10, a peripheral side portion 30 extending continuously upward from the radially outer end of the bottom portion 10, and a cover portion 40 extending continuously upward and radially inward from the peripheral side portion 30 in a curved shape. Each elastic engagement portion 20 is formed by partially cutting open the bottom portion 10 and bending it upward. A space (2) on the bottom portion 10 of the socket 1 and radially inward of each elastic engagement portion 20 is an engagement space 2 that removably receives an engagement protrusion 62 of a stud 60 shown in FIGS. 7 and 8. The peripheral side portion 30 extends upward from the radially outer end of the bottom portion 10 substantially parallel to the axis of the socket 1. In this specification, the axial direction of the socket 1 is essentially synonymous with the up-down direction. The cover portion 40 defines an opening 42 at its radially inner end 41 for receiving an engaging convex shaft 62 of a stud 60 (see FIG. 7 etc.) into the engaging space 2 of the socket 1.

[0017] The bottom portion 10 has a circular bottom opening 11 in its center. The bottom opening 11 is for passing the shaft portion 52 of the attachment member 50 (see Figure 6, etc.) through when attaching the socket 1 to fabric f1 (see Figure 6, etc.) such as clothing. The bottom opening 11 is smaller than the upper opening 42. Around the bottom opening 11 in the bottom portion 10, there is provided a downwardly recessed annular recess 12 and an upwardly protruding annular protrusion 13 adjacent to the radially inner side of the annular recess 12. The radially inner end of the annular protrusion 13 defines the bottom opening 11. The annular protrusion 13 has a step 13a in its vertically intermediate portion, where the diameter is slightly reduced in a stepped manner.

[0018] In the area of the bottom portion 10 radially outward from the annular recess 12, there are five cutouts 14, each corresponding to one of the elastic engagement portions 20, spaced at 72-degree intervals in the circumferential direction. Each cutout 14 is an opening that penetrates the bottom portion 10 from top to bottom. Each cutout 14 is defined by a roughly semi-elliptical cut edge 14a that is separated from the elastic engagement portion 20 and a connecting end edge 14b that connects to the elastic engagement portion 20 between the two radially outer ends of the cut edge 14a. The connecting end edge 14b is located radially inward from the radially outer end of the bottom portion 10. Each elastic engagement portion 20 is bent upward from the connecting end edge 14b of each cutout 14 to nearly 90 degrees and stands up relative to the bottom portion 10. The connecting end edge 14b of each cutout 14 is also the base end edge 14b of each elastic engagement portion 20.

[0019] 2, cutting edge 14a is composed of two straight edges 14ab extending radially inward from both ends of connecting end side 14b in a generally parallel linear fashion, and a semicircular edge 14aa projecting radially inward from the radially inner ends of two straight edges 14ab in a generally semicircular shape. The midpoint of semicircular edge 14aa is the radially innermost end of cutting edge 14a. The radially inner end of cutting edge 14a and its vicinity, i.e., the midpoint of semicircular edge 14aa and its vicinity, slightly extend into the region of annular recess 12 in bottom portion 10. The incision 14, excluding the radially inner end portion that extends into the region of annular recess 12, is formed in the main region of bottom portion 10 (the region of bottom portion 10 excluding annular recess 12, annular protrusion 13, and rib portion 15, described below), which protrudes upward relative to annular recess 12. The upper and lower surfaces of the step 13a of the annular protrusion 13 are at the same level as the upper and lower surfaces of the main region of the bottom 10, and the upper end of the annular protrusion 13 protrudes slightly above the main region of the bottom 10.

[0020] In the region between two circumferentially adjacent cutouts 14 in the bottom portion 10, there are provided rib portions 15 that are elongated in the radial direction and recessed downward. Each rib portion 15 can also be said to be convex toward the underside of the bottom portion 10. The radially inner end of each rib portion 15 is connected to the annular recess 12. The radially outer end of each rib portion 15 is at approximately the same radial position as the connecting end edge 14b of each cutout 14. The degree to which each rib portion 15 recesses downward from the main region of the bottom portion 10 is the same as the degree to which the annular recess 12 recesses. The rib portions 15 play a role in compensating for the reduction in strength of the bottom portion 10 caused by the provision of the cutouts 14.

[0021] Each elastic engagement portion 20 includes a base portion 20a extending upward from the base end side (connecting end side) 14b, and a bulge portion 20b bent upward from the base portion 20a to protrude radially inward, forming a generally C-shaped cross section. The base portion 20a curves radially inward and upward from the base end side 14b at its lower end, then extends linearly in cross section to the bulge portion 20b above. The bulge portion 20b gradually narrows in width along the circumferential direction from its lower end to its upper end (tip) 20d. The upper end 20d of the elastic engagement portion 20 is close to the cover portion 40 but does not contact the cover portion 40. The bulge portion 20b includes an engagement end 20c, which is the radially innermost end of the elastic engagement portion 20.

[0022] The symbol L shown in FIG. 4 is an imaginary line that passes through the radially inner end 41 of the cover portion 40 and runs along the vertical direction (shown only on the left side in FIG. 4). The imaginary line L is parallel to the axis of the socket 1. The imaginary line L in FIG. 4 is represented as a circular imaginary line L in FIG. 2. The imaginary line L in FIG. 2 coincides with the upper opening 42. It can be said that the imaginary line L represents the range over which the cover portion 40 covers the elastic engagement portion 20. In the socket 1 of the first embodiment, the base 20a and the upper and lower ends of the bulge portion 20b of the elastic engagement portion 20 in the initial state are located radially outward from the imaginary line L, and these portions are the "part" of the elastic engagement portion 20 located radially outward from the radially inner end 41 of the cover portion 40 as defined in the claims. Furthermore, the vertically intermediate portion of the bulging portion 20b, including the engaging end 20c, is located radially inward from the imaginary line L, and these portions are the "other portion" of the elastic engaging portion 20 located radially inward from the radially inner end 41 of the cover portion 40 in the claims. In this way, the cover portion 40 covers the elastic engaging portion 20 except for the vertically intermediate portion of the bulging portion 20b, thereby reducing or eliminating situations in which the elastic engaging portion 20 comes into contact with an external object or the like and is subjected to external force. Furthermore, since the socket 1 has a one-piece configuration including the cover portion 40, the cover portion 40 protects each elastic engaging portion 20 from external force while preventing the cover portion 40, which is susceptible to external force, from separating from the peripheral portion 30, which is extremely advantageous.

[0023] FIG. 6 is a cross-sectional view showing the socket 1 attached to fabric f1, such as clothing, by an attachment member 50. The attachment member 50 includes a substantially disk-shaped base portion 51 and a cylindrical shaft portion 52 that protrudes concentrically from the base portion 51. The shaft portion 52 is shown in a crimped state in FIG. 6. The attachment member 50 is composed of two parts: a main body 50A and a cap 50B. The main body 50A includes the shaft portion 52 and a base core 51a. The cap 50B is attached to the radially outer end of the base core 51a of the main body 50A, and the cap 50B and the base core 51a form the base portion 51. To attach the socket 1 to fabric f1, the attachment member 50 is placed on a lower support die of a button attachment machine (not shown), the socket 1 is held by an upper punch die, and the fabric f1 is positioned between the attachment member 50 and the socket 1. The punch die is then lowered. As a result, the shank 52 of the mounting member 50 penetrates upward through the fabric f1, then passes upward through the bottom opening 11 of the socket 1, and is then crimped by the punch die. The end of the crimped shank 52 is received on the step 13a of the annular protrusion 13 of the socket 1. In this way, the socket 1 is attached to the fabric f1. Because the rib portion 15 bites into the fabric f1 when the socket 1 is attached to the fabric f1, it is possible to reduce or eliminate, in the medium to long term, the occurrence of the socket 1 rotating relative to the shank 52 of the mounting member 50.

[0024] FIG. 7 is a cross-sectional view showing a stud (male snap button) 60, which can be engaged with and disengaged from a socket 1, attached to a material f2 by an attachment member 70. The stud 60 is made by processing a single metal plate and includes a base portion 61 and an annular engagement protrusion 62 protruding from the base portion 61. The attachment member 70 includes a disk-shaped base portion 71 and a cylindrical shank portion 72 protruding from the base portion 71. The shank portion 72 is shown in a crimped state in FIG. 7. The base portion 61 of the stud 60 is provided with a bottom opening 63 for passing the shank portion 72 of the attachment member 70 through. The engagement protrusion 62 includes a large-diameter portion 62a whose outer diameter expands near its tip, and a constricted portion 62b whose outer diameter narrows from the large-diameter portion 62a toward the base portion 61. The diameter of the large diameter portion 62a is set to be slightly smaller than the diameter of the opening 42 of the socket 1 and slightly larger than the engagement end diameter, which is the diameter of a circle connecting the engagement ends 20c of the five elastic engagement portions 20. The outer diameter of the constricted portion 62b is approximately the same as the engagement end diameter of the socket 1.

[0025] FIG. 8 is a cross-sectional view showing the connection state between the socket 1 and the stud 60. The stud 60 in FIG. 8 is shown upside down compared to FIG. 7. When connecting the socket 1 and the stud 60, the engaging protrusion 62 of the stud 60 is inserted into the engagement space 2 through the opening 42 of the socket 1. At this time, the large-diameter portion 62a of the engaging protrusion 62 of the stud 60 contacts the engaging end 20c of each elastic engaging portion 20 of the socket 1, temporarily bending each elastic engaging portion 20 radially outward. Then, as soon as the large-diameter portion 62a passes the engaging end 20c, each elastic engaging portion 20 returns to or near its initial position radially inward. This results in the connection state between the socket 1 and the stud 60 as shown in FIG. 7. In this connected state, the bulging portion 20b of each elastic engaging portion 20 of the socket 1 contacts or is close to the narrowed portion 62b of the engaging protrusion 62 of the stud 60.

[0026] FIG. 9 is a bottom view of a socket 1A, which is a modification of the socket 1 of the first embodiment. FIG. 10 is a cross-sectional view of the socket 1A, similar to FIG. 4. FIG. 11 is a cutaway perspective view of the socket 1A, similar to FIG. 5. The socket 1A has substantially the same configuration as the socket 1 described above, except that the bases 20Aa of the five elastic engagement portions 20A described below are provided with recesses 21 as thin-walled portions. Therefore, the same reference numerals are used for the components other than the elastic engagement portions 20A, and their description will be omitted. The points already described for the socket 1 also apply to the socket 1A. Each elastic engagement portion 20A of the socket 1A includes a base 20Aa and a bulge 20Ab, which is a bulge bent upward from the base 20Aa and has a generally C-shaped cross section so as to protrude radially inward. The bulge 20Ab includes an engagement end 20Ac, which is the radially innermost end of the elastic engagement portion 20A. The base 20Aa of each elastic engagement portion 20A is provided with a recess 21 recessed radially outward from the surface of the base 20Aa facing inward in the radial direction. The recess (thin portion) 21 is formed by pressing the base 20Aa and a portion of the bottom 10 adjacent to the base 20Aa to partially compress and recess the thickness along the radial direction. The recess 21 has an elongated oval shape extending from near the connecting end edge (base end edge 14b) of the bottom 10, through the base end edge 14b of the base 20Aa, to slightly above approximately the center in the vertical direction of the base 20Aa. The recess 21 is provided in the widthwise center of the base 20Aa, and the width of the recess 21 (the length along the circumferential direction of the socket 1) is approximately one-third the width of the base 20Aa. By machining a recess 21 in the base 20Aa of each elastic engagement portion 20A, particularly from its base end edge 14b to the bottom 10 near the base end edge 14b, the metal material in the recess 21 portion hardens, increasing the strength of the area including the base end edge 14b, which is the center portion where the elastic engagement portion 20A bends inward and outward in the radial direction, thereby making it possible to maintain the flexibility of each elastic engagement portion 20A over the medium to long term.

[0027] 12 and 13 are top and bottom views of a socket 101 according to a second embodiment of the present invention. FIG. 14 is a cross-sectional view of the socket 101 taken along line BB in FIG. 12. FIG. 15 is a perspective view of the socket 101 broken along line BB in FIG. 12. The socket 101 is a one-piece structure formed by drawing a single metal plate. The socket 101 includes a bottom portion 110, six elastic engagement portions 120 extending continuously from the bottom portion 110, a peripheral side portion 130 extending continuously upward from the radially outer end of the bottom portion 110, and a cover portion 140 extending continuously radially inward from the upper end of the peripheral side portion 130. Each elastic engagement portion 120 is formed by partially cutting open the bottom portion 110, bending it radially inward, and raising it upward. The space (102) on the bottom 110 of the socket 101 and radially inward of each elastic engagement portion 120 is an engagement space 102 that detachably receives the engagement protrusion 62 of the stud 60 shown in Figures 7 and 8. The peripheral side portion 130 extends upward from the radially outer end of the bottom portion 110, substantially parallel to the axis of the socket 101. The cover portion 140 defines, at its radially inner end 141, an opening 142 for receiving the engagement protrusion 62 of the stud 60 (see Figure 7, etc.) in the engagement space 102 of the socket 101.

[0028] The bottom portion 110 includes a substantially horizontal central bottom portion 111 in which a bottom opening 113 is provided, and a peripheral bottom portion 112 that connects the radially outer end of the central bottom portion 111 to the lower end of the peripheral side portion 130. A downwardly recessed annular recess 115 is provided in the central bottom portion 111 between the bottom opening 113 and the radially outer end of the central bottom portion 111.

[0029] The peripheral bottom portion 112 has an inclined portion 112a that slopes radially outward and upward from its radially inner end, a curved portion 112b that curves convexly upward from the upper end of the inclined portion 112a, and a peripheral end portion 112c that extends radially outward from the radially outer end of the curved portion 112b and connects to the lower end of the peripheral side portion 130. The inclined portion 112a and the curved portion 112b of the peripheral bottom portion 112 have six cutouts 114, spaced at 60-degree intervals in the circumferential direction, corresponding to each elastic engagement portion 120. Each cutout 114 is an opening that penetrates the peripheral bottom portion 112 from top to bottom. Each cutout 114 is defined by a roughly U-shaped cut edge 114a that is separated from the elastic engagement portion 120 and a connecting end edge 114b that connects to the elastic engagement portion 120 between the two radially inner ends of the cut edge 114a. The connecting end edge 114b is located at the boundary between the central bottom portion 111 and the peripheral bottom portion 112. Each elastic engagement portion 120 is bent radially inward from the connecting end edge 114b of each cutout portion 114 and protrudes radially inward and upward relative to the peripheral bottom portion 112. The connecting end edge 114b of each cutout portion 114 also serves as the base end edge 114b of each elastic engagement portion 120. Referring to FIG. 13 , the cut edge 114a consists of two side edges 114ab that extend radially outward in a straight line and substantially parallel to each other from both ends of the connecting end edge 114b, and a peripheral edge 114aa that extends substantially circumferentially and connects the radially outer ends of the two side edges 114ab.

[0030] Each elastic engagement portion 120 includes a base portion 120a extending upward from the base end edge (connection end edge) 114b, and a bulge portion 120b bent upward from the base end edge 114b to protrude radially inward, forming a generally C-shaped cross section. The base portion 120a extends obliquely upward and radially outward from the base end edge 114b to the bulge portion 120b in a generally linear cross section. The circumferential width of each elastic engagement portion 120 is generally constant from the base end edge 114b to the upper end (tip of the bulge portion 120b) 120d. The upper end 120d of the elastic engagement portion 120 is adjacent to the cover portion 140 but does not contact the cover portion 140. The bulge portion 120b includes an engagement end 120c, which is the radially innermost end of the bulge portion 120b.

[0031] The symbol L' in FIG. 14 is a virtual line that passes through the radially inner end 141 of the cover portion 140 and runs along the vertical direction (shown only on the left side in FIG. 14). The virtual line L' in FIG. 14 is represented as a circular virtual line L' in FIG. 13. It can be said that the virtual line L' represents the range over which the cover portion 140 covers the elastic engagement portion 120. In the socket 101 of the second embodiment, a portion of the elastic engagement portion 120 in the initial state is radially outer than the virtual line L', and the remaining portion is radially inner than the virtual line L'. More specifically, the upper end of the bulging portion 120b, including the tip 120d, the radially outer portion of the lower half of the bulging portion 120b, and the radially outer portion of the base portion 120a excluding the lower end thereof are radially outer than the virtual line L'. Furthermore, a radially inner portion of bulging portion 120b including engaging end 120c and a radially inner portion including the lower end of base portion 120a are located radially inward of imaginary line L'. In this way, cover portion 140 covers a portion of elastic engaging portion 120, thereby reducing or eliminating the possibility of elastic engaging portion 120 coming into contact with an external object or the like and being subjected to an external force. [Explanation of symbols]

[0032] 1, 1A, 101 studs 2, 102 engagement space 10, 110 bottom 14, 114 incision 15 Rib section 20, 20A, 120 Elastic engagement part 20a, 20Aa, 120a base 20b, 20Ab, 120b bulge 20c, 20Ac, 120c engagement end 20d, 20Ad, 120d Tip of the bulge 21 Recess (thin part) 30, 130 Side 40, 140 Cover 41, 141 Radial inner end of cover part 42, 142 aperture

Claims

1. A metal socket (1, 1A, 101) that can be engaged and disengaged with a stud (60), a circular bottom portion (10, 110); a peripheral side portion (30, 130) extending continuously in one axial direction from a radially outer end portion of the bottom portion (10, 110); a plurality of elastic engagement portions (20, 20A, 120) extending continuously from the bottom portion (10, 110); and a cover portion (40, 140) extending continuously radially inward from the peripheral side portion (30, 130) and defining an opening (42, 142) at a radially inner end (41, 141) for receiving an engagement protrusion (62) of the stud (60); a portion of each of the plurality of elastic engagement portions (20, 20A, 120) is located radially outward from the radially inner end (41, 141) of the cover portion (40, 140), and the remaining portions of each of the plurality of elastic engagement portions (20, 20A, 120) other than the portion are located radially inward from the radially inner end (41, 141) of the cover portion (40, 140); The plurality of elastic engagement portions (20, 20A, 120) include base portions (20a, 20Aa, 120a) connected to the bottom portion (10, 110), The socket, wherein the portion of each of the plurality of elastic engagement portions (20, 20A, 120) includes the base portion (20a, 20Aa).

2. 2. The socket according to claim 1, wherein the bottom portion (10, 110), the peripheral side portion (30, 130), the plurality of elastic engagement portions (20, 20A, 120), and the cover portion (40, 140) are formed from a single metal member.

3. The plurality of elastic engagement portions (20, 20A, 120) include bulging portions (20b, 20Ab, 120b) extending in one axial direction from the base portion (20a, 20Aa, 120a) and bulging radially inward, The bulging portion (20b, 20Ab, 120b) includes an engagement end (20c, 20Ac, 120c) that is located at the innermost position in the radial direction of the bulging portion (20b, 20Ab, 120b), and a tip (20d, 20Ad, 120d) that is the end opposite to the base portion (20a, 20Aa, 120a), the portion of each of the plurality of elastic engagement portions (20, 20A, 120) includes the tip (20d, 20Ad, 120d), 3. The socket according to claim 1, wherein the other portion of each of the plurality of elastic engagement portions includes the engagement end.

4. 2. The socket according to claim 1, wherein the base portion (20Aa) of each of the plurality of elastic engagement portions (20A) includes a thin portion (21) whose thickness is partially compressed.

5. The socket according to any one of claims 1 to 3, wherein the plurality of elastic engagement portions (20, 20A, 120) are formed by partially cutting and bending the bottom portion (10, 110), and the bottom portion (10, 110) includes cutout portions (14, 114) corresponding to each of the plurality of elastic engagement portions (20, 20A, 120).

6. 6. The socket according to claim 5, wherein the bottom portion (10) includes rib portions (15) provided between each pair of the cutout portions (14) adjacent to each other in the circumferential direction.

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