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Title:
ELECTRICAL CRIMP TERMINAL
Document Type and Number:
WIPO Patent Application WO/2017/191524
Kind Code:
A1
Abstract:
An electrical terminal (100) includes a crimp barrel (104) having an interior side (138) and an exterior side (150). The interior side of the crimp barrel defines a channel (132) that extends along a longitudinal axis. The crimp barrel is configured to mechanically hold and electrically connect to one or more electrical conductors (106) of an electrical device (102) received in the channel. The crimp barrel includes multiple primary serrations (146) spaced apart along the longitudinal axis. The primary serrations are groove-shaped recesses formed along the interior side. Adjacent primary serrations are separated from one another by a band. The crimp barrel further includes at least one micro-serration (148) on the band. Each micro-serration is a groove-shaped recess formed along the interior side that has a smaller size relative to the primary serrations.

Inventors:
MYER JOHN MARK (US)
YANCEY RODNEY TIMOTHY (US)
BUSHEY JOHN G (US)
LEIGHT RICKY S (US)
Application Number:
PCT/IB2017/052320
Publication Date:
November 09, 2017
Filing Date:
April 21, 2017
Export Citation:
Click for automatic bibliography generation   Help
Assignee:
TE CONNECTIVITY CORP (US)
International Classes:
H01R4/18
Foreign References:
NL7217871A1974-07-02
Other References:
None
Attorney, Agent or Firm:
VACCARELLI, Lisa Burgin (US)
Download PDF:
Claims:
WHAT IS CLAIMED IS:

1. An electrical terminal (100) comprising: a crimp barrel (104) having an interior side (138) and an exterior side (150), the interior side of the crimp barrel defining a channel (132) that extends along a longitudinal axis (191), the crimp barrel configured to mechanically hold and electrically connect to one or more electrical conductors (106) of an electrical device (102) received in the channel, the crimp barrel including multiple primary serrations (146) spaced apart along the longitudinal axis, the primary serrations being groove-shaped recesses formed along the interior side, adjacent primary serrations being separated from one another by a band (176), the crimp barrel further including at least one micro-serration (148) on the band, each micro-serration being a groove-shaped recess formed along the interior side that has a smaller size relative to the primary serrations.

2. The electrical terminal (100) of claim 1, wherein each primary serration (146) has a width (152) along the longitudinal axis (191) that is greater than a width (154) of each micro-serration (148) along the longitudinal axis.

3. The electrical terminal (100) of claim 1, wherein the primary serrations (146) and the at least one micro-serration (148) have respective depths (156, 158) that extend from the interior side (138) of the crimp barrel (104) towards the exterior side (150), the depths of the primary serrations being greater than the depth of each micro- serration.

4. The electrical terminal (100) of claim 1, wherein a cross-sectional area (162) of the recess of each micro-serration (148) along the longitudinal axis (191) is less than a cross-sectional area (160) of the recess of each primary serration (146) along the longitudinal axis.

5. The electrical terminal (100) of claim 4, wherein the cross-sectional area (162) of the recess of each micro-serration (148) is less than one-fifth of the cross- sectional area (160) of the recess of each primary serration (146).

6. The electrical terminal (100) of claim 1, wherein the band (176) between adjacent primary serrations (146) includes multiple micro-serrations (148) spaced apart along the longitudinal axis (191).

7. The electrical terminal (100) of claim 1, wherein the primary serrations (146) and the at least one micro- serration (148) are elongated laterally along the interior side (138) of the crimp barrel (104) to at least partially surround the one or more electrical conductors (106) in the crimp barrel, the primary serrations extending parallel to one another and to the at least one micro-serration.

8. The electrical terminal (100) of claim 1, wherein each micro-serration (148) on the band (176) extends between and partially defines two adjacent barrel teeth (180), each barrel tooth having a top surface (182) that faces the channel (132) and two tapered sides (166, 170) extending from corresponding edges (184) of the top surface, the edges of the barrel teeth configured to engage and scrape against the one or more electrical conductors (106) during a crimping operation to form metal-to-metal contacts.

9. The electrical terminal (100) of claim 8, wherein the top surfaces (182) of the barrel teeth (180) are concave such that the top surface of a respective barrel tooth bows between the edges (184) towards the exterior side (150).

10. The electrical terminal (100) of claim 1, wherein the primary serrations (146) include two outer primary serrations (146A, 146C), each outer primary serration defining a side (166) of a corresponding band (176) on only an inner side of the outer primary serration, the crimp barrel (104) further including at least one micro-serration (148) along the interior side (138) of the crimp barrel on an opposite outer side of each outer primary serration such that micro-serrations are located on both sides of each primary serration.

Description:
ELECTRICAL CRIMP TERMINAL

BACKGROUND OF THE INVENTION

[0001] The subject matter described and/or illustrated herein relates generally to electrical crimp terminals configured to be crimped to electrical devices, such as cables or wires. Electrical crimp terminals are often used to terminate the ends of wires or other electrical devices. Some electrical terminals include a crimp barrel and an electrical contact. The crimp barrel is crimped around the end of the wire to establish an electrical connection between electrical conductors in the wire and the terminal as well as to mechanically hold the electrical terminal on the wire. When crimped over the wire, the crimp barrel establishes an electrical and mechanical connection between the conductors of the wire and the electrical contact of the terminal, such that the terminal carries current from the wire to the mating component connected to the electrical contact.

[0002] Conductors of wires are often fabricated from metal materials, such as copper and aluminum, which may form poorly conductive oxide layers on the exterior surface of the wire conductors when exposed to air. Furthermore, build-up of surface contaminants from processing steps may further inhibit surface conductivity. Such exterior conductor surface oxide layers must be penetrated in order to form reliable metal-to-metal connections between the metal material of the wire and the metal material of the electrical crimp terminal. For example, some crimp barrels include one or more serrations that, during a crimping operation, are configured to scrape or wipe against the conductors of the wire to displace the oxide layer and expose fresh metal of the conductors for establishing a metal-to-metal connection.

[0003] But, it may be difficult to displace enough of the oxide layer during the crimping operation to achieve a sufficient electrical and mechanical bond, and thereby establish a reliable electrical connection, especially for electrical terminals formed of metal materials that are similar in strength to the materials of the wire conductors. For example, some electrical terminals are formed of lower-strength metals than traditional terminals in order to reduce cost and improve electrical conductivity of the terminals relative to higher-strength metals. But, during a crimping operation, when the terminal has a similar strength or elasticity as the wire conductors, both the terminal and the wire conductors may extrude or flow with similar characteristics such that there may be little differential or relative flow between the terminal and the wire conductors. The reduced differential flow inhibits the ability for the existing serrations to wipe and scrape against the conductors to displace the oxide layer, resulting in a poor electrical connection between the terminal and the wire.

[0004] A need remains for an electrical crimp terminal that is able to displace the oxide layer on electrical conductors in the crimp barrel during a crimping operation to provide a reliable electrical connection between the terminal and the electrical conductors, even when there is limited differential flow between the metal of the terminal and the metal of the conductors during the crimping operation.

[0005] The solution is provided by an electrical terminal as described herein that includes a crimp barrel having an interior side and an exterior side. The interior side of the crimp barrel defines a channel that extends along a longitudinal axis. The crimp barrel is configured to mechanically hold and electrically connect to one or more electrical conductors of an electrical device received in the channel. The crimp barrel includes multiple primary serrations spaced apart along the longitudinal axis. The primary serrations are groove-shaped recesses formed along the interior side. Adjacent primary serrations are separated from one another by a band. The crimp barrel further includes at least one micro-serration on the band. Each micro-serration is a groove- shaped recess formed along the interior side that has a smaller size relative to the primary serrations.

[0006] The invention will now be described by way of example with reference to the accompanying drawings in which: [0007] Figure 1 is a perspective view of an electrical crimp terminal and an electrical device according to an embodiment.

[0008] Figure 2 is a bottom perspective view of a punching die and a portion of the electrical crimp terminal according to an embodiment.

[0009] Figure 3 is a cross-sectional view showing the punching die in contact with a crimp barrel of the electrical crimp terminal.

[0010] Figure 4 is a close-up portion of the punching die and the crimp barrel shown in Figure 3.

[0011] Figure 5 is a cross-sectional view of a serration array on the crimp barrel of the electrical crimp terminal taken along line 5-5 shown in Figure 1.

[0012] Figure 6 is a close-up portion of the serration array on the crimp barrel shown in Figure 5.

[0013] Figure 7 is a cross-sectional view of a portion of a terminal assembly including one or more conductors of the electrical device in the crimp barrel of the electrical crimp terminal.

[0014] Figure 8 shows the terminal assembly in a post-crimped state according to an embodiment, such that the crimp barrel is compressed into mechanical engagement and electrical contact with the one or more conductors of the electrical device.

[0015] One or more embodiments described herein disclose an electrical terminal configured to be crimped to an electrical device, such as a wire or a cable, to form a terminal assembly (or contact lead). The electrical terminal may provide an improved electrical connection with the electrical device to which the terminal is crimped relative to known terminals. For example, the electrical terminal includes a serration array that includes serrations of multiple different sizes along an interior side of the terminal that engages the conductors of the electrical device. The serration array may provide enhanced scraping to remove or displace the poorly-conductive oxide layer on the conductors relative to the serrations on known terminals. For example, the serration array of the terminal disclosed herein may take advantage a limited differential flow or extrusion of the conductors relative to the terminal during the crimping process, which occurs when metal material of the conductors flows towards and at least partially fills the recesses formed by larger serrations of the serration array. As the metal material of the conductors flows towards the larger serrations, edges of the smaller serrations (which are proximate to the larger serrations) scrape against the metal material to remove and/or displace the oxide layer, creating a reliable metal-to-metal electrical connection. Since the serration array takes advantage of a limited differential flow between the conductors and the terminal, the terminal may be formed of a metal material that has a similar strength or elasticity as the metal material of the conductors. The metal material of the terminal may be preferable over metal materials used for known terminals because, for example, the metal material of the terminal disclosed herein may have a higher conductivity and a lower cost than the materials of known terminals.

[0016] Figure 1 is a perspective view of an electrical crimp terminal 100 and an electrical device 102 according to an embodiment. The electrical device 102 may be a wire, a cable, or another structure with current-carrying conductors 106. The electrical device 102 is configured to be crimped to the terminal 100. The terminal 100 includes a crimp barrel 104 that receives a portion of the electrical device 102 therein. In Figure 1, the electrical device 102 is poised for loading into the crimp barrel 104 prior to a crimping operation. During the crimping operation, the crimp barrel 104 is pressed into engagement with one or more electrical conductors 106 of the electrical device 102 to electrically connect the terminal 100 to the electrical device 102. The one or more electrical conductors 106 may be one or more metal wires, strands, or the like. The crimping operation also mechanically secures the terminal 100 to the electrical device 102, forming a terminal assembly (or electrical lead). [0017] The terminal 100 is oriented with respect to a longitudinal axis 191, a lateral axis 192, and a vertical or elevation axis 193. The axes 191-193 are mutually perpendicular. Although the elevation axis 193 appears to extend generally parallel to gravity, it is understood that the axes 191-193 are not required to have any particular orientation with respect to gravity. The terminal 100 extends a length along the longitudinal axis 191 between a front end 108 and a rear end 110. The terminal 100 has a crimp segment 114, a contact segment 116, and a transition segment 118 that are spaced apart along the longitudinal axis 191. The crimp segment 114 defines the rear end 110, the contact segment 116 defines the front end 108, and the transition segment 118 is disposed between the crimp and contact segments 114, 116. As used herein, relative or spatial terms such as "front," "rear," "left," "right," "top," and "bottom" are only used to identify and distinguish the referenced elements and do not necessarily require particular positions or orientations relative to the surrounding environment of the terminal 100.

[0018] The contact segment 116 includes an electrical contact 120. In the illustrated embodiment, the electrical contact 120 is a pin or beam that is configured to be received in a socket or receptacle of a mating contact (not shown). But, the electrical contact 120 may have other shapes in other embodiments, such as, but not limited to a cage-shaped receptacle, a spring contact, a tab, a pole shoe, or the like. The transition segment 118 may provide structural support for the terminal 100 and/or a means for retaining the terminal 100 in a housing (not shown). For example, the transition segment 118 may include a protrusion 119 that is configured to engage a latch or shoulder of the housing. The crimp segment 114 includes the crimp barrel 104. In the illustrated embodiment, the crimp segment 114 also includes an insulation crimp barrel 122 that is disposed rearward of the crimp barrel 104 (which is a conductor crimp barrel). The insulation crimp barrel 122 is configured to be crimped into engagement with an insulation layer 124 of the electrical device 102. The insulation layer 124 surrounds the one or more electrical conductors 106. An exposed portion 126 of the one or more electrical conductors 106 protrudes from the insulation layer 124. The exposed portion 126 is received in the crimp barrel 104, unlike the insulation layer 124. In an alternative embodiment, the terminal 100 does not include the contact 120 and/or the transition segment 118. For example, the terminal 100 may only include the crimp barrel 104 and may be configured to join two electrical devices 102 end-to-end.

[0019] The crimp barrel 104 extends along the longitudinal axis 191 between a contact end 128 and a device end 130. The device end 130 is rearward of the contact end 128. The crimp barrel 104 defines a channel 132 that receives the exposed portion 126 of the one or more conductors 106 therein in preparation for a crimping operation. In the pre-crimped state of the terminal 100 shown in Figure 1, the crimp barrel 104 has a U- or V-shaped cross-section taken along the lateral axis 192. The crimp barrel 104 includes a base 134 and two wings or tabs 136 that extend from laterally opposite lateral sides of the base 134. The channel 132 is defined by an interior side 138 of the barrel 104. The channel 132 is open along a top 140 of the terminal 100 between distal ends 142 of the wings 136. During the crimping operation, the wings 136 are bent towards one another into the channel 132 to engage the one or more conductors 106 of the electrical device 102. The terminal 100 is an "F" type terminal in an embodiment, but in other embodiments the terminal 100 may be an "O" type terminal that has a closed cylindrical barrel instead of an open, U-shaped barrel.

[0020] The crimp barrel 104 includes a serration array 144 along the interior side 138. The serration array 144, as shown and described in more detail herein, includes at least one primary serration 146 and at least one micro-serration 148 spaced apart along the longitudinal axis 191. Multiple primary serrations 146 and multiple micro-serrations 148 are shown in Figure 1. The primary serrations 146 and micro- serrations 148 are recesses along the interior side 138 in the shape of grooves. The micro-serrations 148 have a smaller size than the primary serrations 146. As used herein, the term "micro-serrations" merely identifies a type of serration that is smaller in at least one size dimension than the primary serrations 146, and is not used to signify a specific size range or scale. [0021] In the illustrated embodiment, the primary serrations 146 and the micro-serrations 148 are elongated laterally along the interior side 138 of the crimp barrel 104. For example, the serrations 146, 148 extend along the base 134 and along the wings 136 towards the distal ends 142 of the wings 136. Each serration 146, 148 may extend continuously from one wing 136 to the other wing 136, or may be divided into multiple segments along the lateral length of the respective serration 146, 148. In an embodiment, the primary serrations 146 extend parallel to one another. The micro-serrations 148 extend parallel to one another and parallel to the primary serrations 146. The primary serrations 146 and the micro-serrations 148 extend transverse to the longitudinal axis 191, such as perpendicular to the longitudinal axis 191.

[0022] During a crimping operation, the exposed portion 126 of the one or more conductors 106 is received in the channel 132 of the crimp barrel 104, and the electrical device 102 extends from the device end 130 of the crimp barrel 104. The one or more conductors 106 are held generally coaxial with the longitudinal axis 191. The serrations 146, 148 of the serration array 144 extend around a perimeter of the one or more conductors 106. The terminal 100 is located on an anvil (not shown) of a crimping apparatus. A crimp tooling member (not shown) of the crimping apparatus descends from above the terminal 100. The crimp tooling member engages an exterior side 150 of the crimp barrel 104 and bends the wings 136 to engage and surround the one or more conductors 106 in the channel 132. The serration array 144, as described herein, is configured to wipe and/or scrape an exterior surface of the one or more conductors 106 as the crimp barrel 104 is compressed around the conductors 106 to remove and/or displace an oxide layer on the conductors 106, creating metal-to-metal bonds via cold welding.

[0023] Figure 2 is a bottom perspective view of a punching die 200 and a portion of the terminal 100 according to an embodiment. In Figure 2, a bottom side 202 of the punching die 200 engages the interior side 138 of the crimp barrel 104 to form the serration array 144 (shown in Figure 1). Figure 3 is a cross-sectional view showing the punching die 200 in contact with the crimp barrel 104. Figure 4 is a close-up portion of the punching die 200 and the crimp barrel 104 shown in Figure 3.

[0024] The terminal 100 is shown in Figures 2-4 having a flat, planar shape. For example, the terminal 100 may be produced by stamping and forming a metal panel or sheet. As shown in Figure 2, the terminal 100 has already been stamped prior to contacting the punching die 200, but the terminal 100 has not yet been formed. The crimp barrel 104 is formed into the U-shape shown in Figure 1 subsequent to forming the serration array 144. Although not shown in Figure 2, the terminal 100 may be placed on a die plate 204 for the punching operation shown in Figures 2-4. As show in Figure 3, the exterior side 150 of the crimp barrel 104 engages the die plate 204, and the punching die 200 is moved in a punching direction 206 vertically towards the terminal 100 from above the terminal 100.

[0025] The punching die 200 includes multiple elongated ridges 208 that protrude from the bottom side 202 thereof. The ridges 208 engage the interior side 138 of the crimp barrel 104 to form the serration array 144 (shown in Figure 1). In an embodiment, the ridges 208 include primary ridges 208A and micro-ridges 208B. The primary ridges 208A have a larger size than the micro-ridges 208B. The primary ridges 208A form the primary serrations 146 (shown in Figure 1), and the micro-ridges 208B form the micro-serrations 148 (Figure 1). As shown in Figure 2, the primary ridges 208A extend parallel to the micro-ridges 208B. The ridges 208 may be formed by machining the bottom side 202 of the punching die 200 to define the protruding ridges 208. As shown in Figure 2, the punching die 200 includes multiple micro-ridges 208B on either side of each primary ridge 208A such that multiple micro-ridges 208B are disposed between each pair of adjacent primary ridges 208 A. The ridges 208 A, 208B may be configured in other arrangements in other embodiments.

[0026] Figures 3 and 4 show the punching die 200 at a bottom dead position relative to the die plate 204 and the terminal 100 thereon. The bottom dead position represents the end of a punch stroke. Therefore, the punching die 200 does not move closer to the die plate 204 than the position shown in Figures 3 and 4. At the bottom dead position, the ridges 208 engage the terminal 100 and protrude into the interior side 138. The portions of the bottom side 202 of the punching die 200 surrounding the ridges 208 and between the ridges 208 are spaced apart from and do not engage the terminal 100. The terminal 100 is compressed between the ridges 208 of the punching die 200 and the die plate 204. As the ridges 208 compress the terminal 100 along the crimp barrel 104, the ridges 208 displace some of the metal material of the terminal 100. For example, the ridges 208 force the metal material to flow to areas of reduced pressure, such as into the cavities 210 between adjacent ridges 208. As shown in Figure 4, the interior side 138 of the terminal 100 between adjacent ridges 208 defines concave surfaces 182. The concave surfaces 182 are bowed between outer edges 184 such that a middle portion 186 of each concave surface 182 is more proximate to the exterior side 150 (shown in Figure 3) of the crimp barrel 104 than a proximity of the outer edges 184 to the exterior side 150. Thus, the outer edges 184 are raised relative to the middle portion 186. The concave surfaces 182 are formed from the displacement of metal material of the terminal 100 as the ridges 208 penetrate the crimp barrel 104.

[0027] Figure 5 is a cross-sectional view of the serration array 144 on the crimp barrel 104 of the terminal 100 (shown in Figure 1) taken along line 5-5 shown in Figure 1. Figure 6 is a close-up portion of the serration array 144 on the crimp barrel 104 shown in Figure 5. The serration array 144 in the illustrated embodiment extends a majority of the length of the crimp barrel 104 along the longitudinal axis 191 between the contact end 128 and the device end 130. In an alternative embodiment, the serration array 144 may extend less than half of the length of the crimp barrel 104, and the crimp barrel 104 optionally may include multiple serration arrays 144. The serration array 144 includes multiple primary serrations 146 and multiple micro-serrations 148. The primary serrations 146 and the micro-serrations 148 are both recesses defined along the interior side 138 of the crimp barrel 104. The primary serrations 146 are formed by the primary ridges 208A (shown in Figure 3), and the micro-serrations 148 are formed by the micro- ridges 208B (Figure 3). Thus, the primary serrations 146 and the micro-serrations 148 are recesses that have generally the same shapes as the primary ridges 208A and micro- ridges 208B, respectively. The primary serrations 146 have larger sizes than the micro- serrations 148, such that the primary serrations 146 are larger cavities than the micro- serrations 148.

[0028] The primary serrations 146 have two side walls 166 and a bottom wall 168 between the side walls 166. The side walls 166 may be tapered towards each other from the interior side 138 to the bottom wall 168 such that a width 152 of the primary serration 146 along the longitudinal axis 191 at the interior side 138 is greater than the width of the bottom wall 168. In the illustrated embodiment, the primary serrations 146 have a trapezoidal cross-sectional shape, but the primary serrations 146 may have other shapes in other embodiments, such as rectangular, triangular, pentagonal, or the like. The micro-serrations 148 have two side walls 170 that taper towards each other with depth from the interior side 138 toward the exterior side 150. In the illustrated embodiment, the micro-serrations 148 have a generally triangular shape such that the two side walls 170 meet at a point 172 of the micro-serration 148. Alternatively, the side walls 170 may connect to a narrow bottom wall similar to the bottom wall 168 of the primary serrations 146 instead of meeting at the point 172.

[0029] The width 152 of the primary serrations 146 along the longitudinal axis 191 at the interior side 138 is greater than a width 154 of the micro- serrations 148. For example, the width 152 of the primary serrations 146 may be between two and ten times as wide as the width 154 of the micro-serrations 148. The primary serrations 146 and the micro-serrations 148 have respective depths 156, 158 that extend from the interior side 138 towards the exterior side 150 of the crimp barrel 104. The depth 156 of the primary serrations 146 is greater than the depth of the micro- serrations 148. For example, the depth 156 of the primary serrations 146 may be two times as deep as the depth 158 of the micro-serrations 148. The primary serrations 146 have a cross-sectional area 160 along the longitudinal axis 191 that is greater than a cross-sectional area 162 of the micro-serrations 148. The cross-sectional areas 160, 162 are defined between the walls of the respective serrations 146, 148 and a plane 163 of the interior side 138. For example, in an embodiment, the cross-sectional area 162 of a micro-serration 148 may be less than half, less than one-third, less than one-fourth, and/or less than one-fifth of the cross-sectional area 160 of a primary serration 146. In an alternative embodiment, the depth 156 of the primary serrations 146 may be equal to or less than the depth 158 of the micro-serrations 148, although the width 152 of the primary serrations 146 is greater than the width 154 of the micro-serrations 148 such that the cross-sectional area 160 of the primary serrations 146 is greater than the cross-sectional area 162 of the micro-serrations 148.

[0030] In an embodiment, the primary serrations 146 and micro- serrations 148 in the serration array 144 are arranged with at least one micro-serration 148 between two adjacent primary serrations 146. As used herein, adjacent primary serrations 146 refers to two primary serrations 146 that do not have any intervening primary serrations 146 therebetween, although there are intervening micro- serrations 148 between the adjacent primary serrations 146. The serration array 144 may have an alternating sequence of primary serrations 146 and groups 174 of micro-serrations 148. Each group 174 of micro-serrations 148 includes at least one micro-serration 148. In the illustrated embodiment, each group 174 has at least two micro-serrations 148, and some groups 174 have three micro-serrations 148. The groups 174 and the primary serrations 146 alternate along the length of the array 144 between the contact end 128 and the device end 130 of the crimp barrel 104. The array 144 in the illustrated embodiment includes three primary serrations 146 and four groups 174 of micro-serrations 148. Each primary serration 146 is surrounded on each side (for example, on both a contact end-side and a device end-side) by a corresponding group 174 of micro-serrations 148. In the illustrated embodiment, the serration array 144 includes a first primary serration 146A, a second primary serration 146B, and a third primary serration 146C. The serration array 144 further includes a first group 174A of multiple micro-serrations 148 that is disposed between the contact end 128 and the first primary serration 146 A, a second group 174B of micro-serrations 148 that is disposed between the first and second primary serrations 146A, 146B, a third group 174C of micro-serrations 148 that is disposed between the second and third primary serrations 146B, 146C, and a fourth group 174D of micro- serrations 148 that is disposed between the third primary serration 146C and the device end 130. The array 144 may include different numbers and/or arrangements of the primary serrations 146 and the micro-serrations 148 in other embodiments. For example, in one alternative embodiment, one or both axial ends of the array 144 (most proximate to the contact end 128 and the device end 130) may be defined by a primary serration 146 instead of by a micro-serration 148.

[0031] Since the primary serrations 146 are larger recesses than the micro-serrations 148, two adjacent primary serrations 146 define a band 176 therebetween. Each band 176 is a portion of the crimp barrel 104 with sides defined by respective side walls 166 of the adjacent primary serrations 146. The band 176 has a height along the vertical axis 193 that is generally equal to the height of the side walls 166 along the vertical axis 193. At least some of the bands 176 include a group 174 of at least one micro-serration 148 thereon. For example, in an embodiment, each band 176 includes multiple micro-serrations 148 that are spaced apart from one another along the longitudinal axis 191. Since there are three primary serrations 146A-C shown in Figure 5, the primary serrations 146A-C define two bands 176, with one band 176 on each side of the second, or inner, serration 146B. The first and third primary serrations 146A, 146C are outer primary serrations along the length of the array 144. Each of the outer serrations 146 A, 146C defines a side of a corresponding band 176 on only an inner side of the respective outer serration 146 A, 146C which faces towards the inner serration 146B. The portions of the interior side 138 of the crimp barrel 104 along the respective outer sides of the outer serrations 146A, 146C, which face away from the inner serration 146B, include at least one micro-serration 148 in the illustrated embodiment. Thus, micro-serrations 148 may be disposed on both sides of each of the primary serrations 146. [0032] The primary serrations 146 and the micro-serrations 148 define barrel teeth 180 between adjacent serrations 146, 148. Some barrel teeth 180 are defined between two micro-serrations 148, and other barrel teeth 180 are defined between one micro-serration 148 and one primary serration 146. Each barrel tooth 180 has a top surface 182 and two sides extending from corresponding edges 184 of the top surface 182. The sides of each tooth 180 are defined by the side walls 166, 170 of the respective serrations 146, 148 that define the corresponding tooth 180. For example, the sides of a barrel tooth 180A defined between two adjacent micro-serrations 148 are defined by two side walls 170 and may have equal heights along the vertical axis 193. The sides of a barrel tooth 180B defined between one primary serration 146 and one micro-serration 148, on the other hand, may have different heights because one side is defined by a side wall 166 of the primary serration 146 and the other side is defined by a side wall 170 of the micro-serration 148. The sides of the teeth 180 in the illustrated embodiment are tapered or sloped such that the teeth 180 have generally trapezoidal shapes, but the teeth 180 may have other shapes in other embodiments, such as rectangular shapes. The edges 184 of the barrel teeth 180 are configured to engage and scrape against the one or more electrical conductors 106 (shown in Figure 1) of the electrical device 102 (Figure 1) during a crimping operation to remove and/or displace an oxide layer to form metal-to- metal contacts. The serration array 144 in the illustrated embodiment includes 26 discrete edges 184, but other amounts of teeth 180 and edges 184 may be formed in other embodiments.

[0033] In the illustrated embodiment, the top surfaces 182 of at least some of the barrel teeth 180 are concave. For example, the top surface 182 of a respective tooth 180 bows or curves towards the exterior side 150 of the crimp barrel 104 with distance along the width of the tooth 180 between the edges 184. A middle portion 186 of the top surface 182 of a respective tooth 180 is located more proximate to the exterior side 150 than a proximity of each of the edges 184 of the tooth 180 to the exterior side 150. The top surfaces 182 may be concave due to the pressing operation that forms the serrations 146, 148 in the interior side 138 of the crimp barrel 104, as described above with reference to Figure 4. The concave top surfaces 182 of the barrel teeth 180 allow the edges 184 to have relatively sharp angles, which may enhance the scraping of the edges 184 against the one or more electrical conductors 106. The top surfaces 182 of the barrel teeth 180 may be relatively linear in an alternative embodiment.

[0034] Figure 7 is a cross-sectional view of a portion of a terminal assembly 300 including the one or more conductors 106 of the electrical device 102 (shown in Figure 1) in the channel 132 of the crimp barrel 104 of the terminal 100. In Figure 7, the terminal assembly 300 is in a pre-crimped state. Figure 8 shows the terminal assembly 300 in a post-crimped state according to an embodiment, such that the crimp barrel 104 is compressed into mechanical engagement and electrical contact with the conductors 106. Referring to Figure 7, during a crimping operation a crimping apparatus compresses the crimp barrel 104 along the vertical axis 193 such that opposing portions 302, 304 of the crimp barrel 104 are forced inwardly into the channel 132 towards one another along respective crimping directions 306, 308. The interior side 138 of the crimp barrel 104 engages and compresses the one or more conductors 106, causing the metal of the conductors 106 to extrude (for example, flow, slide, or otherwise move) to regions of reduced pressure. Typically, the primary regions of reduced pressure are at the contact end 128 and the device end 130 (shown in Figure 8) of the crimp barrel 104. Thus, during the crimping operation, the metal of the conductors 106 may flow in expanding directions 310, 311 towards the ends 128, 130.

[0035] In an embodiment, the metal of the crimp barrel 104 may also flow in the expanding directions 310, 311 due to the compressive forces. For example, the crimp barrel 104 may be composed of one or more metals that have a relatively similar strength (or modulus of elasticity) as the one or more metals of the conductors 106. The conductors 106 may be composed of a first metal material including at least one of copper or aluminum, and the terminal 100 may be composed of a second metal material that also include at least one of copper or aluminum. Optionally, the metal materials of the conductors 106 may be the same as the metal materials of the terminal 100. Since the strength of the conductors 106 may be at least similar to the strength of the terminal 100, there may be little differential metal flow between the crimp barrel 104 and the conductors 106 proximate to the interior side 138 of the crimp barrel 104 during the crimping operation, which limits the ability of the crimp barrel 104 to scrape against the conductors 106 to displace oxide layers and establish reliable metal-to-metal contacts. However, the serration array 144 is configured to utilize local areas of differential flow to enhance the scraping, even when the metal material of the terminal 100 is similar in strength to the metal materials of the conductors 106.

[0036] As shown in Figure 7, the primary serrations 146 define areas or pockets of reduced pressure. During the crimping operation, some metal of the conductors 106 proximate to the primary serrations 146 flows axially along opposite first and second directions 312, 314 towards the corresponding primary serrations 146 and at least partially fills the primary serrations 146. As shown in Figure 8, the metal of the conductors 106 fills each of the primary serrations 146 due to the compressive forces during the crimping operation. In an embodiment, as the metal of the conductors 106 proximate to the crimp barrel 104 flows in the first and second directions 312, 314 relative to the crimp barrel 104, the edges 184 of the barrel teeth 180 along the interior side 138 of the crimp barrel 104 engage and scrape against the conductors 106. For example, a segment of one conductor 106 disposed in engagement with the interior side 138 of the crimp barrel 104 along one of the bands 176 may be stretched in both directions 312, 314 towards the primary serrations 146 located on both sides of the band 176. As the metal material of the conductor 106 is stretched, the edges 184 of the barrel teeth 180 along the band 176 (defined by the primary serrations 146 and the micro- serrations 148) scrape and wipe against the flowing metal material to remove and/or displace an oxide layer or other surface contaminants on the conductor 106. The scraping provides a reliable metal-to-metal contact between the crimp barrel 104 and the conductor 106, which supports the electrical conductivity of the resulting terminal assembly 300. [0037] Thus, the serration array 144 is configured to provide reliable metal-to-metal electrical contacts between the crimp barrel 104 and the one or more conductors 106, even when there is little relative extrusion flow between the crimp barrel 104 and the conductors 106 due to a similarity in metal strength characteristics. Experimental testing has demonstrated that terminals 100 having the serration array 144 form terminal assemblies having more desirable electrical conductivity characteristics than some known terminals that do not include the serration array 144 described herein, such as lower initial resistance measurements, lower final resistance measurements after testing, and/or lower delta resistance measurements after testing at various terminal sizes.

[0038] It is to be understood that the above description is intended to be illustrative, and not restrictive. For example, the above-described embodiments (and/or aspects thereof) may be used in combination with each other. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from its scope. Dimensions, types of materials, orientations of the various components, and the number and positions of the various components described herein are intended to define parameters of certain embodiments, and are by no means limiting and are merely exemplary embodiments. Many other embodiments and modifications within the spirit and scope of the claims will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.