Electrical terminal with inner ferrule with reinforced retention feature

Abstract

An electrical terminal (200) includes a cylindrical inner ferrule (208) having a first portion (212) and a second portion (214) separated by at least one seam (216) therebetween. The inner surface of the first portion (212) and / or the second portion (214) defines a clamping feature (220) configured to deform a cylindrical dielectric layer (222) surrounding an electrical conductor (224) of the cable. The electrical terminal (200) also includes a cylindrical outer ferrule (210) surrounding the inner ferrule (208). A method (300) of assembling a cable is also presented.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to U.S. Patent Application No. 18 / 380,975, filed on October 17, 2023, entitled “Electrical Terminal with an InnerFerrule Having Enhanced Retention Features,” the entire disclosure of which is incorporated herein by reference. Technical Field

[0002] The present invention relates generally to electrical terminals and, more particularly, to an electrical terminal having an inner ferrule with enhanced retention features. Background Art

[0003] An electrical terminal, such as one attached to a coaxial cable, has an inner ferrule knurled on its outer surface to provide a high friction interface between the inner ferrule and a shielded conductor of the coaxial cable surrounding the inner ferrule, thereby increasing the axial retention of the coaxial cable by the inner ferrule. Figure 1 As shown, the inner surface of the inner ferrule is smooth and does not significantly increase the axial retention force of the inner ferrule on the coaxial cable.

[0004] Other electrical terminal designs have an inner ferrule folded under the shield conductor to increase the axial retention of the inner ferrule to the coaxial cable. This second inner ferrule design requires a more complex manufacturing process to assemble the electrical terminal. Summary of the invention

[0005] In some aspects, the technology described herein relates to an electrical terminal, comprising: a cylindrical inner ferrule having a first portion and a second portion, the first portion and the second portion separated by a seam therebetween. An inner surface of the first portion and / or the second portion defines a clamping feature configured to deform a cylindrical dielectric layer surrounding an electrical conductor of a cable. The electrical terminal also includes a cylindrical outer ferrule surrounding the inner ferrule.

[0006] In some aspects, the technology described herein relates to a method of assembling a cable, comprising the steps of: · forming gripping features on the surface of the sheet metal preform; forming a cylindrical inner ferrule from a sheet metal preform, the cylindrical inner ferrule having a first portion and a second portion separated by a seam such that the gripping feature is defined by an inner surface of the inner ferrule; Placing an inner ferrule over a cylindrical dielectric layer surrounding the electrical conductor of the cable; closing the seam so that each portion of the seam has a width less than or equal to 0.1 mm, thereby forming two seams between the first portion and the second portion; deforming the cylindrical dielectric layer using a clamping feature when the seams are closed; and • Place a cylindrical outer ring around the inner ring. BRIEF DESCRIPTION OF THE DRAWINGS

[0007] The present invention will now be described by way of example with reference to the accompanying drawings, in which:

[0008] Figure 1 is a cross-sectional view of an electrical terminal according to the prior art.

[0009] Figure 2 is an isometric view of an electrical terminal according to some embodiments of the present invention.

[0010] Figure 3 According to some embodiments of the present invention Figure 2 Isometric view of the shield terminal of the electrical terminal.

[0011] Figure 4 According to some embodiments of the present invention Figure 3 Cross-sectional view of the shield terminal.

[0012] Figure 5 is in an open state according to some embodiments of the present invention Figure 3 End view of the shield terminal.

[0013] Figure 6 is in a closed state according to some embodiments of the present invention Figure 3 End view of the shield terminal.

[0014] Figure 7 According to some embodiments of the present invention Figure 2 A cross-sectional view of an electrical terminal.

[0015] Figure 8 According to some embodiments of the present invention Figure 7 An enlarged view of a portion of.

[0016] Fig. 9 is a flow chart of a method of assembling a cable according to some embodiments of the present invention.

[0017] Fig.10 According to some embodiments of the present invention, Figure 3 Top view of the sheet metal preform of the shield terminal. DETAILED DESCRIPTION

[0018] Figures 2 to 8A non-limiting example of an electrical terminal configured to terminate an electrical cable is shown. In some embodiments, the electrical terminal is a coaxial cable terminal 200 .

[0019] like Figure 2 As shown, the coaxial cable terminal 200 is configured to terminate a cable 206. Figure 2 In the illustrated embodiment, the electrical cable 206 is a coaxial cable, but in other embodiments, the electrical terminal can be configured to terminate other types of cables. In some embodiments, the coaxial cable terminal 200 includes a shield terminal 202 and a separate cylindrical outer ferrule 210, the shield terminal 202 being attached to the shield conductor 204 of the coaxial cable 206 by a cylindrical inner ferrule 208 that is part of the shield terminal 202. The outer ferrule 210 surrounds the inner ferrule 208 and is crimped onto the coaxial cable 206 over the inner ferrule 208 to secure the coaxial cable terminal 200 to the coaxial cable 206. As described in more detail below, it is expected that the interaction of the shield terminal 202 and the coaxial cable 206 provides an axial retention force F that must be overcome if the coaxial cable terminal 200 is to be separated from the coaxial cable 206.

[0020] like Figure 3 As shown, the cylindrical outer ferrule 210 has been removed to make the cylindrical inner ferrule 208 of the coaxial cable terminal 200 visible. Figure 3 As shown, the inner ferrule 208 has a first portion 212 and a second portion 214 separated by at least one seam 216. In the illustrated embodiment, the inner ferrule 208 includes two seams 216 that are approximately 180 degrees apart. The inner surface 218 of the first portion 212 and / or the second portion 214 defines one or more gripping features 220 (at Figure 4 The cylindrical dielectric layer 222 surrounding the center conductor 224 of the coaxial cable 206 is deformed, thereby increasing the axial retention force F, which must be overcome if the coaxial cable terminal 200 is to be separated from the coaxial cable 206.

[0021] Figure 4 is a cross-sectional view of the coaxial cable terminal 200 showing the clamping feature 220 located on the inner surface 218 of the cylindrical inner ferrule 208. Figure 4 In the cross-sectional view shown, the coaxial cable 206 is not shown, thereby allowing the clamping feature 220 to be visible in this view. Figure 4 The clamping features 220 of the illustrated example are a plurality of negative radial grooves that are offset from one another in the circumferential and axial directions. The clamping features 220 provide a displaced dielectric layer 222 (e.g., as shown) when the inner ferrule 208 is attached to the coaxial cable 206 to create a retaining interaction. Figure 7In some embodiments, when the dielectric layer 222 of the inner ferrule 208 is compressed around the coaxial cable 206, the clamping feature 220 will act as a release recess into which the dielectric material of the dielectric layer 220 flows. The clamping feature 220 provides a geometry for the inner ferrule 208 that causes the axial retention force F to be overcome to pull the coaxial cable terminal 200 from the coaxial cable 206 to be higher than when there is a Figure 1 Axial retention force is shown for two smooth mating surfaces on the inner ferrule 108 and the dielectric layer 120 of the coaxial cable. By adding the clamping feature 220 at the interface between the inner surface 218 of the inner ferrule 208 and the dielectric layer 222, the shield conductor 204 / inner ferrule 208 interface is no longer the sole source of mechanical retention strength.

[0022] In some embodiments, the gripping feature 220 is a negative (negative) gripping feature formed in the inner surface 218 of the inner ferrule 208, which may include one or more radial grooves, depressions, dimples, notches, serrations, recesses, and / or knurls formed in the inner wall of the inner ferrule. In some embodiments, the gripping feature 220 is a positive (positive) gripping feature formed in the inner surface 218 of the inner ferrule 208, which may include one or more radial ribs, protrusions, projections, bulges, bumps, and / or barbs formed in the inner wall of the inner ferrule. These lists of negative and positive gripping features are not exhaustive.

[0023] In some embodiments, the inner ferrule 208 and the clamping feature 220 are sized, shaped, and configured such that when the edges 226 of the first portion 212 and the second portion 214 are drawn together, the smallest diameter of the inner surface 218 of the first portion 212 and the second portion 214 is less than the diameter of the dielectric layer 222 of the coaxial cable 206, thereby closing or minimizing the seam 216, as shown in FIG. Figure 6 This causes portions of the dielectric layer 222 to deform or compress, thereby increasing the friction between the inner ferrule 208 and the dielectric layer 222 and, therefore, increasing the axial retention force F that needs to be overcome to separate the inner ferrule 208 from the coaxial cable 206 .

[0024] like Figure 5 and Figure 6 As shown, in some embodiments, the first portion 212 and the second portion 214 of the inner ferrule 208 are integrally formed with each other and with the shield terminal 202 of the coaxial cable terminal 200. When the inner ferrule 208 is placed on the dielectric layer 222 of the coaxial cable 206, the two seams 216 can be as shown in FIG. Figure 5 Open as shown. Figure 6As shown, when the seams 216 are closed or minimized, as the first portion 212 and the second portion 214 are pulled together, the width of the two seams 216 between the first portion 212 and the second portion 214 of the inner ferrule 208 is less than or equal to 0.1 mm, thereby clamping the dielectric layer 222. When the outer ferrule 210 is crimped around the inner ferrule 208, the outer ferrule 210 holds the two seams 216 in place. Figure 6 Shown in closed condition.

[0025] like Figure 6 As best shown in FIG. 1 , in some embodiments, the shapes of the edges 226 of the first portion 212 and the second portion 214 are mirror images and are identical. The edges 226 of the first portion 212 and the second portion 214 follow complementary serpentine paths. In some embodiments, after the first portion 212 and the second portion 214 are drawn together and secured by the outer ferrule 210, the distance between portions of the edges 226 of the first portion 212 and the second portion 214 is less than or equal to 0.1 millimeters. In some embodiments, these serpentine edges 226 form teeth and indentations that contact each other to limit compression of the dielectric layer 222, thereby reducing impedance irregularities in the coaxial cable terminal 200, which would negatively affect its high frequency electrical performance.

[0026] In some embodiments, the inner ferrule 208 has two seams 216 that allow the inner ferrule 208 to open to easily receive the dielectric layer 222, but also allow the inner ferrule 208 to be closed to a smaller constant diameter. Figure 8 As shown, the soft material around the dielectric layer 222 such as the coaxial cable 206 compresses the inner ferrule 208 with two seams 216 so that the dielectric layer 22 is more evenly squeezed into the negative clamping feature 220, thereby increasing the friction between the inner ferrule 208 and the dielectric layer 220. In other embodiments, the soft material around the dielectric layer 222 such as the coaxial cable 206 compresses the inner ferrule 208 with two seams 216 so that the positive clamping feature 220 deforms the dielectric layer 222 more evenly, thereby also increasing the friction between the inner ferrule 208 and the dielectric layer 220. Alternative embodiments of the inner ferrule are contemplated to have a single seam instead of two seams 216.

[0027] In some embodiments, Figure 3 As shown, the outer surface 230 of the inner ferrule 208 is knurled 228 to improve conductivity between the inner ferrule 208 and the shielded conductor 204 of the coaxial cable 206 and to further increase the axial retention force F.

[0028] Fig. 9 A flow chart of a method 300 for assembling a cable is shown. At step 302, a gripping feature 220 is formed in a surface of a sheet metal preform 400. For example, Fig.10A sheet metal preform 400 is shown that will form the cylindrical inner ferrule 208. In some embodiments, the gripping features 220 are formed by negative gripping features in the inner surface 218 of the inner ferrule 208, which negative (female) gripping features may include one or more radial grooves, depressions, dimples, notches, serrations, recesses, and / or knurls formed in the inner wall of the inner ferrule 208. In some embodiments, the gripping features 220 are positive (male) gripping features formed in the inner surface 218 of the inner ferrule 208, which may include one or more radial ribs, protrusions, projections, convexities, bumps, and / or barbs formed in the inner wall of the inner ferrule. The list of these negative and positive gripping features is not exhaustive.

[0029] In step 304, the sheet metal preform 400 is formed into Figure 3 The cylindrical inner ferrule 208 is shown having a first portion 212 and a second portion 214 separated by a seam such that the gripping feature 220 is defined by the inner surface 218 of the inner ferrule 208. In step 306, as shown Figure 7 As shown, the inner ferrule 208 is placed on the dielectric layer 222 surrounding the electrical conductor 224 of the coaxial cable 206 .

[0030] In step 308, the seam between the first portion 212 and the second portion 214 of the cylindrical inner ferrule 208 is closed so that the width of each portion of the seam is less than or equal to 0.1 mm. Figure 6 Thus, two seams 216 are formed between the first portion 212 and the second portion 214 .

[0031] In step 310, if Figure 8 As shown, when the seam is closed, the dielectric layer 222 is deformed by the application of force. In some embodiments, the dielectric layer 222 is deformed due to the flow of the dielectric layer 22 into the negative clamping features 220 located on the inner surface of the cylindrical inner ferrule 208. In some embodiments, the deformation of the dielectric layer 222 is the result of the positive clamping features 220 located on the inner surface of the cylindrical inner ferrule 208 deforming the dielectric layer 22.

[0032] In step 312, if Figure 8 As shown, a cylindrical outer ferrule 210 is placed around the inner ferrule 208 to compress the inner ferrule 208 .

[0033] Although the illustrated example relates to a coaxial cable terminal 200 for a coaxial cable 206, other embodiments are contemplated where the electrical terminal is configured for other types of cables, such as shielded twisted pair cables, or any other cable type requiring inner and outer ferrules to secure the electrical terminal to the cable.

[0034] In some aspects, the technology described herein relates to an electrical terminal, comprising: a cylindrical inner ferrule having a first portion and a second portion separated by two seams therebetween. An inner surface of the first portion and / or the second portion defines a clamping feature configured to deform a cylindrical dielectric layer surrounding an electrical conductor of a cable. The electrical terminal also includes a cylindrical outer ferrule surrounding the inner ferrule.

[0035] In some aspects, the technology described herein relates to an electrical terminal wherein the clamping feature is a negative clamping feature selected from the list consisting of radial grooves, depressions, indentations, dimples, notches, serrations, recesses, and knurls.

[0036] In some aspects, the technology described herein relates to an electrical terminal wherein the clamping feature is a positive clamping feature selected from the list consisting of a radial rib, a protrusion, a projection, a boss, a bump, and / or a barb.

[0037] In some aspects, the technology described herein relates to an electrical terminal in which a first portion and a second portion are integrally formed with each other.

[0038] In some aspects, the technology described herein relates to an electrical terminal in which a first portion and a second portion are integrally formed with a shield terminal of the electrical terminal.

[0039] In some aspects, the technology described herein relates to an electrical terminal wherein the electrical cable is a coaxial cable.

[0040] In some aspects, the technology described herein relates to an electrical terminal wherein a minimum diameter of a combined inner surface of a first portion and a second portion is smaller than a diameter of a cylindrical dielectric layer.

[0041] In some aspects, the technology described herein relates to an electrical terminal in which edges of a first portion and a second portion are mirror images and coincident.

[0042] In some aspects, the technology described herein relates to an electrical terminal in which edges of a first portion and a second portion follow complementary serpentine paths.

[0043] In some aspects, the technology described herein relates to an electrical terminal in which portions of edges of a first portion and a second portion abut to limit deformation of a dielectric layer.

[0044] In some aspects, the technology described herein relates to an electrical terminal wherein an outer surface of an inner ferrule is knurled.

[0045] In some aspects, the technology described herein relates to a method of assembling a cable, comprising the steps of: · forming gripping features on the surface of the sheet metal preform; forming a cylindrical inner ferrule from a sheet metal preform, the cylindrical inner ferrule having a first portion and a second portion separated by a seam such that the gripping feature is defined by an inner surface of the inner ferrule; Placing an inner ferrule over a cylindrical dielectric layer surrounding the electrical conductor of the cable; closing the seam so that each portion of the seam has a width less than or equal to 0.1 mm, thereby forming two seams between the first portion and the second portion; deforming the cylindrical dielectric layer using a clamping feature when the seams are closed; and • Place a cylindrical outer ring around the inner ring.

[0046] In some aspects, the technology described herein is directed to a method wherein the gripping feature is a negative gripping feature selected from the list consisting of radial grooves, depressions, dimples, pits, notches, serrations, recesses, and knurls.

[0047] In some aspects, the technology described herein relates to a method wherein the gripping feature is a positive gripping feature selected from the list consisting of radial ribs, protrusions, projections, bosses, bumps, and / or barbs.

[0048] In some aspects, the technology described herein relates to a method in which a first portion is integrally formed with a second portion.

[0049] In some aspects, the technology described herein relates to a method that also includes limiting deformation of the dielectric layer by abutting edges of the first portion and the second portion.

[0050] In some aspects, the technology described herein relates to a method in which the cable is a coaxial cable.

[0051] In some aspects, the technology described herein relates to a method wherein, prior to the step of closing the seam, the diameter of the cylindrical dielectric layer is greater than a smallest diameter of a combined inner surface of the first portion and the second portion.

[0052] In some aspects, the technology described herein relates to a method wherein edges of a first portion and a second portion are mirror images and coincident.

[0053] In some aspects, the technology described herein relates to a method in which edges of a first portion and a second portion follow complementary serpentine paths.

[0054] Although the present invention is described with reference to (one or more) exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and that equivalents may be substituted for the elements of the present invention without departing from the scope of the present invention. In addition, many modifications may be made without departing from the basic scope of the present invention to adapt specific circumstances or materials to the teachings of the present invention. Therefore, the present invention is not limited to the disclosed (one or more) embodiments, but includes all embodiments within the scope of the appended claims.

[0055] As used herein, “one or more” includes a function performed by one element, a function performed by more than one element, such as in a distributed fashion, several functions performed by one element, several functions performed by several elements, or any combination of the above.

[0056] It should also be understood that, although in some cases, the terms first, second, etc. are used to describe various elements in this article, these elements should not be limited by these terms. These terms are only used to distinguish one element from another element. For example, without departing from the scope of the various described embodiments, the first contact can be referred to as the second contact, and similarly, the second contact can be referred to as the first contact. Both the first contact and the second contact are contacts, but they are not identical contacts.

[0057] The terms used in the description of the various embodiments herein are only for the purpose of describing specific embodiments and are not intended to be limiting. As used in the description of the various described embodiments and in the appended claims, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any and all possible combinations of one or more associated listed items. It should also be understood that the terms "comprising", "containing", "including" and / or "comprising" used in this specification specifically refer to the presence of stated features, wholes, steps, operations, elements and / or parts, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, parts and / or their groups.

[0058] As used herein, the term "if" may be alternatively interpreted as "when" or "upon" or "in response to determining" or "in response to detecting," depending on the context. Similarly, the phrase "if it is determined" or "if [the state or event] is detected" may be alternatively interpreted as meaning "upon determining" or "in response to determining" or "upon detecting [the condition or event]" or "in response to detecting [the condition or event]," depending on the context.

[0059] In addition, although the terms of regulations or directions may be used herein, these elements should not be limited by these terms. Unless otherwise specified, all regulations or directions are used to distinguish one element from another element, and unless otherwise specified, do not represent any particular order, order of operation, direction or orientation.

Claims

1. An electrical terminal (200), comprising: a cylindrical inner ferrule (208) having a first portion (212) and a second portion (214) separated by at least one seam (216) therebetween, wherein an inner surface (218) of the first portion (212) and / or the second portion (214) defines a clamping feature (220) configured to deform a cylindrical dielectric layer (222) surrounding an electrical conductor (224) of a cable (206); and A cylindrical outer ferrule (210) surrounds the inner ferrule (208).

2. The electrical terminal (200) according to claim 1, characterized in that: The gripping feature (220) is a negative gripping feature selected from the list consisting of radial grooves, depressions, dimples, pits, notches, serrations, recesses, and knurls.

3. The electrical terminal (200) according to claim 1, characterized in that: The gripping features (220) are positive gripping features selected from the list consisting of radial ribs, protrusions, projections, ridges, bumps and / or barbs.

4. The electrical terminal (200) according to claim 1, characterized in that: The first portion (212) and the second portion (214) are integrally formed with each other.

5. The electrical terminal (200) according to claim 1, characterized in that: The first portion (212) and the second portion (214) are integrally formed with the shielding terminal (202) of the electrical terminal (200).

6. The electrical terminal (200) according to claim 1, characterized in that: The cable (206) is a coaxial cable.

7. The electrical terminal (200) according to claim 1, characterized in that: The smallest diameter of the combined inner surface of the first portion (212) and the second portion (214) is smaller than the diameter of the cylindrical dielectric layer (222).

8. The electrical terminal (200) according to claim 1, characterized in that: The edges (226) of the first portion (212) and the second portion (214) are mirror images and coincident.

9. The electrical terminal (200) according to claim 1, characterized in that: The edges (226) of the first portion (212) and the second portion (214) follow complementary serpentine paths.

10. The electrical terminal (200) according to claim 1, characterized in that: Portions of the edges (226) of the first portion (212) and the second portion (214) are configured to limit deformation of the dielectric layer (222).

11. The electrical terminal (200) according to claim 1, characterized in that: The outer surface (230) of the inner ferrule (208) is knurled.

12. A method (300) of assembling a cable, comprising: forming a gripping feature (220) in a surface of a sheet metal preform (400); forming a cylindrical inner ferrule (208) from the sheet metal preform (400) having a first portion (212) and a second portion (214) separated by a seam (216) such that the gripping feature (220) is defined by an inner surface (218) of the inner ferrule (208); placing the inner ferrule (208) on a cylindrical dielectric layer (222) surrounding an electrical conductor (224) of a cable (206); Closing the seam so that the width of each portion of the seam (216) is less than or equal to 0.1 mm, thereby forming two seams (216) between the first portion (212) and the second portion (214); When the seam is closed, deforming the cylindrical dielectric layer (222) using a clamping feature (220); as well as A cylindrical outer ferrule (210) is placed around the inner ferrule (208).

13. The method (300) according to claim 12, characterized in that: The gripping feature (220) is a negative gripping feature (220) selected from the list consisting of radial grooves, depressions, dimples, pits, notches, serrations, recesses, and knurls.

14. The method (300) according to claim 12, characterized in that: The gripping feature (220) is a positive gripping feature (220) selected from the list consisting of radial ribs, protrusions, projections, ridges, bumps and / or barbs.

15. The method (300) according to claim 12, characterized in that: The first portion (212) and the second portion (214) are integrally formed.

16. The method (300) according to claim 12, characterized in that: Also includes: The dielectric layer (222) is restricted from deformation by abutting the edges (226) of the first portion (212) and the second portion (214).

17. The method (300) of claim 12, characterized in that: The cable (206) is a coaxial cable.

18. The method (300) of claim 12, characterized in that: Prior to the step (308) of closing the seam, the cylindrical dielectric layer (222) has a diameter that is greater than a minimum diameter of the combined inner surfaces of the first portion (212) and the second portion (214).

19. The method (300) of claim 12, wherein: The edges (226) of the first portion (212) and the second portion (214) are mirror images and coincident.

20. The method (300) of claim 12, characterized in that: The edges (226) of the first portion (212) and the second portion (214) follow complementary serpentine paths.

Images