Self-retaining springs for flat wiping contacts

Abstract

A leaf spring for a flat wipe connector includes a front segment having a first surface corresponding to a plane, the front segment further including a front edge configured to connect the leaf spring to the flat wipe connector. The leaf spring further includes a rear segment having a second surface angled relative to the plane corresponding to the first surface of the front segment. The rear segment further includes a third surface connected to the second surface and oriented at an angle relative to the second surface. At least a portion of the edge of the rear segment is configured to interact with a positive stop of a connector housing to lock the leaf spring within the connector housing when the leaf spring is inserted into the connector housing.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 068,848, filed on August 21, 2020, the contents of which are incorporated herein by reference in their entirety. Technical Field

[0003] The present invention relates generally to electrical connectors, methods for assembling electrical connectors, and more particularly to self-retaining springs for flat wipe type electrical contacts. Background Art

[0004] Generally, electrical connectors including flat wipe contact connectors are known in the art. For example, flat wipe contact technology can be used in applications such as power connections for material handling trucks, and single-pole and double-pole flat wipe contact connectors can be used for storage battery connections.

[0005] In one embodiment, U.S. Patent Application Publication No. 2009 / 0093149, which is incorporated herein by reference in its entirety, describes a flat wiping contact and a method for producing the same. For example, a plastic housing can be molded with a channel or groove through the housing that has a large backside opening for the conductor and a more defined front opening for making an electrical connection with a mating connector. The channel is configured with sidewall slots for positioning and retaining a leaf spring that, in turn, retains the contact and provides the necessary wiping pressure when mated with another connector.

[0006] The method for assembling this connector can include inserting the spring into the housing through the large back opening. After the spring is inserted, the spring is locked in place in its slot by cold forming (riveting) a portion of the plastic housing behind the rear end of the spring. On the outside of the housing, a flat wiping contact is mated to the appropriate conductor. The contact is then installed in the housing through the large rear end opening and slid forward until it latches onto the front end of the spring.

[0007] While the noted electrical connectors may be suitable for their intended purpose, there remains a strong desire for improved flat wipe connectors that require easier assembly but still function as flat wipe connectors. Summary of the Invention

[0008] An exemplary embodiment of a leaf spring for a flat wipe connector includes a front segment having a first surface corresponding to a plane, the front segment further including a front edge configured to connect the leaf spring to the flat wipe connector. The leaf spring further includes a rear segment having a second surface angled relative to the plane corresponding to the first surface of the front segment. The rear segment further includes a third surface connected to the second surface and oriented at an angle relative to the second surface. At least a portion of the edge of the rear segment is configured to interact with a positive stop of a connector housing to lock the leaf spring within the connector housing when the leaf spring is inserted into the connector housing.

[0009] An example system for accommodating a flat wipe connector includes a connector housing including a first opening configured to accommodate the flat wipe connector. The system further includes a leaf spring secured within the connector housing and further configured to secure the flat wipe connector within the connector housing. The connector housing further includes a positive stop feature abutting a jog feature of the leaf spring.

[0010] A method for assembling a flat wipe connector includes forming a connector housing configured to receive a leaf spring through a first opening, the connector housing including an integrally formed positive stop. The method further includes inserting a leaf spring having a transition feature into the first opening of the connector housing and into a locked position within the connector housing. The transition feature of the leaf spring abuts the positive stop of the connector housing to lock the leaf spring into the connector housing. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1A is a cross-sectional perspective view of an example electrical connector housing for a flat wipe contact having a cold-formed rivet.

[0012] Figure 1B yes Figure 1A A cross-sectional perspective view of an exemplary electrical connector housing with flat wiping contacts installed therein.

[0013] Figure 2 is a top right perspective view of an exemplary leaf spring according to the teachings of the present disclosure.

[0014] Figure 3 According to the teachings of this disclosure Figure 8 The cross section line Z in Figure 2 A right top perspective view of a cross section of a leaf spring,

[0015] Figure 4 According to the teachings of this disclosure Figure 2 Front view of the leaf spring.

[0016] Figure 5 According to the teachings of this disclosure Figure 2 Rear view of the leaf spring.

[0017] Figure 6 According to the teachings of this disclosure Figure 2 Left side view of the leaf spring.

[0018] Figure 7 According to the teachings of this disclosure Figure 2 Right side view of the leaf spring.

[0019] Figure 8 According to the teachings of this disclosure Figure 2 Top view of the leaf spring.

[0020] Figure 9 According to the teachings of this disclosure Figure 2 Bottom view of the leaf spring.

[0021] Figure 10 is a perspective view of an example connector housing having two leaf springs and two electrical connectors inserted therein.

[0022] Figure 11 is a diagram showing cross-sectional cutting lines according to the teachings of the present disclosure Figure 10 A perspective view of an example connector housing.

[0023] Figure 12 According to the teachings of this disclosure Figure 11 The cross section line A in Figure 10 2 is a cross-sectional perspective view of an example connector housing.

[0024] Figure 13 According to the teachings of this disclosure Figure 12 Close-up view of a cross-sectional perspective view of a .

[0025] Figure 14 According to the teachings of this disclosure Figure 12 An alternative close-up view of the cross-sectional perspective.

[0026] Figure 15 Shown along the teachings of the present disclosure Figure 11 The cross section line A in Figure 10 Another cross-sectional perspective view of the connector housing.

[0027] Figure 16 According to the teachings of this disclosure Figure 11 The cross section line B in Figure 10 A cross-sectional perspective view of the connector housing.

[0028] Figure 17 is a top right perspective view of a first alternative leaf spring in accordance with the teachings of the present disclosure.

[0029] Figure 18 is a right top perspective view of a second alternative leaf spring in accordance with the teachings of the present disclosure.

[0030] Figure 19 is a top right perspective view of a third alternative leaf spring in accordance with the teachings of the present disclosure.

[0031] Figure 20 is a right top perspective view of a fourth alternative leaf spring in accordance with the teachings of the present disclosure. DETAILED DESCRIPTION

[0032] The following description of example methods and apparatus is not intended to limit the scope of the description to the precise form or format detailed herein. Rather, the following description is intended to be illustrative so that others may follow its teachings.

[0033] A self-retaining spring for a flat wipe contact electrical connector is described herein and can be inserted into a flat wipe contact housing. The self-retaining spring and housing are advantageously shaped so that the spring is retained within the housing when inserted. Thus, the housings of various embodiments described herein do not require cold forming (riveting) to retain the spring within the housing.

[0034] Reference Figure 1A and Figure 1B , shows an example of a housing and a non-self-retaining spring. In particular, Figure 1A and Figure 1B Shown is a perspective view of a single pole housing 10 for a flat wipe connector, cut away to reveal internal details.

[0035] The rear opening 12 and the front opening 14 define a passage or recess through the housing 10. In this case, the front end is configured as a hermaphroditic or genderless connector, having a complementary jaw 15 and U-shaped shroud 17 structure that can be connected to another identical connector rotated 180 degrees so that the contact surfaces properly engage. The opposing offset jaws 15 align upon connection to enclose the engaged contacts 32, and the U-shaped shroud 17 on each mating connector acts to longitudinally and rotationally align and accommodate the opposing connector jaws 15 during a straight-in connection motion. The U-shaped shroud limits this type of connector to a straight-in connection motion.

[0036] Refer again Figure 1AThe leaf spring 16 is retained by a spring base extension 18, which is held in two opposing spring seats or slots 20 (only one shown) adjacent to and parallel to the base plate 24. The spring slots 20 are clearly configured to open to or be accessible from the rearward opening 12 for spring insertion. The leaf spring 16 is inserted through the rearward opening 12 such that the extension 18 slides into the slots 20. The spring is retained in its final position in the slots 20 by a spring rivet 26, which is driven upward by external pressure through the base plate 24, just aft of the base of the spring. After the leaf spring 16 is inserted into the housing 10, the rivet 26 is cold-formed into the base plate 24 of the housing 10. Thus, the leaf spring 16 is locked in place because the leading edge of the extension 18 is restricted from moving past the leading edge of the slots 20, and the trailing edge of the leaf spring 16 is restricted from moving by the rivet 26. The cantilevered front end of the leaf spring 16 extends past the barrier wall 22 and is biased upwardly away from the base plate 24 .

[0037] refer to Figure 1B To describe the assembly; the contact 30 includes a front wiping surface 32 terminated by a spring hook 34 and a rear conductor receiver 36 (conductor not shown). The contact 30 is installed by inserting it into the rear opening 12 so that the front wiping surface 32 passes under the barrier wall 22, traveling along the upwardly biased leaf spring 16 until the spring hook 34 latches or snaps onto the front edge or end of the leaf spring 16. The housing is sized so that the front end of the conductor receiver 36 abuts the barrier wall 22 at this point, thereby locking the contact 30 in place, restricting its further forward or rearward movement, and limiting its vertical movement only by compression of the leaf spring 16.

[0038] Thereafter, in operation, the floating action provided by the spring 16 enables the contact 30 to be depressed sufficiently when mated with another opposing connector to accommodate the slight vertical displacement caused by the wiping motion which brings the two opposing contacts into compressive engagement of their respective wiping surfaces 32 through which current is passed.

[0039] However, if the number of manufacturing steps is reduced, the time required to manufacture Figure 1A and Figure 1B The cost and time of installing the connector shown in FIG. Specifically, after inserting the leaf spring 16, the connector must be riveted by deforming the material of the housing 10. The embodiments disclosed herein include an improved connector housing and an improved leaf spring that can be inserted into the improved connector housing so that the leaf spring is automatically retained in the connector housing without riveting the connector housing. Thus, the connector and leaf spring described herein can be used to eliminate the manufacturing step of riveting the connector housing.

[0040] Other connectors use a two-part housing design so that the two parts can be fastened around the leaf spring to secure the leaf spring within the housing. However, such processes also use additional steps that can be avoided by using the embodiments disclosed herein. That is, the two-part housing design requires multiple housing parts to be molded, and the spring connector must be placed in the first housing part, and then the second housing part is fastened to the first housing part. In addition, the two-part housing can be less durable than a one-piece connector housing. Using the embodiments disclosed herein, only a single connector housing needs to be molded, and there is no need to fasten the two connector housing pieces together, thereby reducing the time, cost, and effort of assembly.

[0041] In addition, a connector housing that can accommodate multiple leaf springs and connectors can be advantageously formed and assembled according to the methods described herein. In particular, because the connector housing does not require riveting after the leaf springs are inserted, the housing connector can be more varied in terms of connector shape, size, number, etc., because it does not require any riveting to assemble the connector.

[0042] Figure 2 is a perspective view of an exemplary leaf spring 200 that may be used in various embodiments as disclosed herein. The leaf spring includes a front section 216 and a middle section 212, which together may be similar to Figure 1A and Figure 1B The middle section includes extensions 218 on both sides that can slide into slots in the connector housing, similar to the Figure 1A and Figure 1B The extension 18 of the leaf spring 16 slides into the slot 20 of the connector housing 10.

[0043] The leaf spring 200 also includes a rear section 202 that advantageously enables the leaf spring 200 to be inserted into a connector housing and automatically retained therein, as described with respect to FIG. Figures 10 to 16 In particular, various features of the rear section 202 of the leaf spring interact with the connector housing such that the leaf spring 200 is retained therein without having to rivet the connector housing, having a two-part housing, or the like.

[0044] The rear section 202 of the leaf spring 200 includes two edges 204 and 206 that are as wide as the extension 218. Therefore, when the leaf spring 200 is inserted into the connector housing, the edges 204 and 206 can be received by the slot of the connector housing similar to the extension 218. The leaf spring 200 also includes an opening 208 so that the transition 210 can be formed in the rear section 202, but the two edges 204 and 206 can remain in the rear section 202.

[0045] The turning portion 210 bends downward away from the rest of the leaf spring 200. Figures 10 to 16 As shown and described, the deflection portion 210 interacts with a positive stop formed in the connector housing while inserting the leaf spring 200 into the connector and interferes with the positive stop after full insertion to lock the leaf spring 200 in the connector.

[0046] Figure 3 It is along Figure 8 The cross section line Z in Figure 2 FIG2 is a right-side perspective view of a cross-section of the leaf spring 200. Specifically, the cross-section is taken along a plane passing through the opening 208 to better illustrate the transition portion 210 of the leaf spring 200. The transition portion 210 includes an angled portion 220 and a flat portion 222. The flat portion 222 forms an edge 224 that can advantageously interfere with a positive stop of the connector housing to secure the leaf spring 200 within the housing. The flat edge can advantageously increase the force required to forcibly separate the connector housing and the leaf spring 200 if a force is applied along the leaf spring 200 in a direction opposite to the direction in which the leaf spring 200 was initially inserted into the housing.

[0047] The angled portion 220 and the flat portion 222 can be formed by bending a portion of the rear section 202 to form the transition portion 210. For example, the transition portion 210 can be formed by bends 226 and 228. The bends 226 and 228 can have the same or different bend radii, and can also have different radii in different embodiments. A method for forming the leaf spring 200 can include cutting the opening 208, bending the rear section 202 to form the bend 226, and then bending the rear section 202 to form the bend 228, thereby forming the transition portion 210.

[0048] Figure 4 yes Figure 2 A front view of the leaf spring 200. Figure 5 This is its rear view. Figure 6 It is its left view. Figure 7 This is its right side view. Figure 8 This is its top view. Figure 9 This is its bottom view.

[0049] Figure 10 is a perspective view of an exemplary connector housing 1000 having two leaf springs 216 and two electrical connectors 30 inserted therein. Figure 11 is a diagram showing the cross-section line A. Figure 10 A perspective view of an exemplary connector housing 1000 is shown. Figure 12 It is along Figure 11 The cross section line A in Figure 10 FIG. 1 is a cross-sectional perspective view of an exemplary connector housing 1000 . Figure 13 yes Figure 12 Close-up view 1300 of a cross-sectional perspective view. Figure 14 is an exemplary connector housing 1000 Figure 12 An alternative close-up view 1400 of a cross-sectional perspective view.

[0050] like Figure 13 and Figure 14 As shown, the leaf spring or self-retaining spring 1306 is in its fully installed position within the connector housing 1304. The deflection feature 1406 of the leaf spring has moved past the positive stop 1404. The middle section of the leaf spring is slightly curved (eg, Figure 2 、 4 5 ), the extensions can thus create a resistance fit within the slots of connector housing 1304. When leaf spring 1306 is inserted into connector housing 1304, the slots bias the mid-segment, and thus the entire leaf spring 1306, toward the bottom of the connector housing. Consequently, once the end of leaf spring 1306 slides past positive stop 1404, deflection feature 1406 is biased downward to abut positive stop 1404. Thus, once fully inserted, deflection feature 1406 interferes with positive stop 1404 to secure leaf spring 1306 within connector housing 1304 and position flat wiping contact 1302 within connector housing 1304 so that it can contact another flat wiping contact within another connector housing. The entire rear segment 1402 further supports deflection feature 1406 of leaf spring 1306.

[0051] Figure 15 Shown along Figure 11 The cross section line A in Figure 10 1000 is a cross-sectional perspective view of the connector housing 1000. In particular, Figure 15 A slot 230 is shown which may accommodate an edge (e.g., Figure 2 The extension 218 of the leaf spring 2 and one of the edges 204). Figure 16 As further shown, the shape of the slot 230 is similar to Figure 1A and Figure 1B The shape of the slot 20 of the connector housing 10 is different. Figure 16 It is along Figure 11 The cross section line B in Figure 10 1 is a cross-sectional perspective view of the connector housing 1000.

[0052] In particular, the slot 230 has a wider portion that narrows further into the connector housing 1000 until eventually the slot 230 has a constant width at portion 232. Once the leaf spring 200 is fully inserted into the connector housing 1000, the constant width portion 232 can accommodate Figure 2 The middle section 212 of the leaf spring 200 is shown in FIG. As disclosed herein, the constant width portion 232 can interact with the slightly curved middle section 212 to bias the leaf spring's corner feature toward the bottom of the connector housing. Thus, once the leaf spring is fully inserted, it will automatically lock into place within the connector housing because the constant width portion 232 of the connector housing will interact with the middle section 212 to prevent the leaf spring from moving upward, downward, or forward, while the positive stop of the connector housing will interact with the corner feature of the leaf spring to prevent the leaf spring from moving backward.

[0053] Furthermore, the slot 230 starts out wide and gradually leads the middle section 212 to the constant width portion 232. This configuration allows the edge and extension of the leaf spring to more easily enter the slot 230 (e.g., as opposed to the connector housing, where the slot 230 is entirely the width of the constant width portion 232). Thus, the slot 230 is shaped and configured to make it easier and faster to insert the leaf spring into the connector housing.

[0054] The leaf spring 200 disclosed herein has other advantages. Riveting, as described above, can compromise the sealing requirements of a connector because the riveting process can weaken the connector and / or thin the walls of the connector where the riveting occurs. Additionally, riveting can require that a connector having multiple contacts be laterally positioned and oriented in the same direction in order to properly rivet the connector housing. Because riveting does not restrict how the contacts are oriented, removing riveting from the process allows the contacts in the housing to be oriented in different ways.

[0055] In another advantage, the leaf spring includes a transition feature (e.g., transition feature 210 of leaf spring 200) that is positioned separate or spaced apart from the middle section of the leaf spring, which secures the leaf spring within the connector housing. By spacing the transition feature sufficiently far from the other sections of the leaf spring, the entire rear section of the leaf spring can deflect during insertion into the insulator housing. This can reduce stress on the transition feature during insertion. The reduced stress during insertion allows for a rigid geometry and material to be used for the transition feature itself, thereby increasing the spring retention force of the leaf spring. In other words, the transition feature can remain rigid while allowing the rear section to deflect as a whole due to the interaction of the transition feature with the positive stop feature during insertion of the leaf spring.

[0056] The deflection feature can also be placed approximately in the middle of the rear section of the leaf spring. In this way, any force acting on the leaf spring causing it to press against the positive stop will be distributed approximately evenly across the leaf spring, rather than causing the leaf spring to develop a moment or otherwise have uneven forces applied to it from the positive stop.

[0057] Apart from Figure 2-16Other configurations of connector housings and leaf springs besides those shown in FIG. 1 may also be used to implement self-retaining springs for flat wiping contacts. Figure 17-20 Various examples of other leaf springs that may be used in various embodiments of the present disclosure are shown.

[0058] Figure 17 is a right side perspective view of the first alternative leaf spring. Figure 17 The leaf spring is similar to Figure 2 The leaf spring 200, except that the bend forming the turning feature has a smaller radius than the bends 226 and 228. Figure 2 and Figure 17 Other smaller or larger radii outside of those shown in . In addition, leaf springs without circular bends can be formed that still have a turning feature as disclosed herein or similar to locking into a connector housing.

[0059] Figure 18 is a right side perspective view of the second alternative leaf spring. Figure 18 The leaf spring of has only a single bend in the rear section to form a turning feature.

[0060] Figure 19 is a right side perspective view of the third alternative leaf spring. Figure 19 The leaf spring can be bent completely downward to function similarly to the hinge feature disclosed herein. Figure 19 The rear section of the leaf spring in does not have an edge that fits within the slot of the connector housing, but still has a middle section with an extension that fits into the slot of the connector housing as disclosed herein.

[0061] Figure 20 is a right side perspective view of the fourth alternative leaf spring. Figure 20 The leaf spring is configured with two wings instead of a rear portion. The wings can, for example, be bent outwards so that they can interact with positive stops formed in the sides of the connector housing. Once Figure 20 With the leaf spring 20 fully inserted, the wings can move past the positive stop so that they interfere with the positive stop to prevent the leaf spring from moving back out of the connector housing.

[0062] Thus, as is apparent from the various leaf spring configurations disclosed herein, many different types, shapes, and configurations of leaf springs can be used to form a self-retaining leaf spring that automatically locks into the connector housing upon insertion. Such leaf springs can be made of any type of material, such as plastic, metal (e.g., stainless steel), or any other material suitable for the desired specifications of the flat wipe connector. The connector housing can be made of an insulating material, such as plastic, rubber, or any other desired insulating material.

[0063] Although certain example methods and apparatus have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers all methods, apparatus, and articles of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.

Claims

1. A leaf spring for a flat wipe connector, comprising: a front segment having a first surface corresponding to a plane, the front segment further comprising a front edge configured to connect the leaf spring to the flat wipe connector; and a rear section having a second surface angled relative to a plane corresponding to the first surface of the front section, wherein the rear section further comprises a third surface connected to the second surface and oriented at an angle relative to the second surface, wherein at least a portion of the edge of the rear section is configured to interact with a positive stop feature of the connector housing to lock the leaf spring within the connector housing when the leaf spring is inserted into the connector housing, and wherein the third surface is part of a transition feature, the transition feature comprising the third surface and a fourth surface connected to the third surface, wherein the fourth surface is substantially parallel to the second surface and angled relative to the third surface, wherein an edge of the rear segment configured to interact with the positive stop feature is positioned at least partially along the fourth surface.

2. The leaf spring of claim 1 , further comprising a middle section between the front section and the rear section, wherein: The front section has a first width, and The middle section and the rear section each have a second width.

3. The leaf spring according to claim 2, wherein The middle section includes opposing edges configured to slide into corresponding slots in the connector housing.

4. The leaf spring according to claim 1, wherein The rear section further includes an opening extending from an edge of the third surface toward the front section. The leaf spring of claim 4 , wherein the opening is adjacent to the third surface.

6. The leaf spring according to claim 5, wherein The rear section further includes opposing edges configured to slide into corresponding slots of the connector housing, wherein the opening is located between the opposing edges.

7. The leaf spring of claim 6, wherein the opposing edges are generally parallel to each other and angled relative to the third surface.

8. The leaf spring of claim 1, wherein the leaf spring comprises metal.

9. A system for accommodating a flat wipe connector, comprising: a connector housing including a first opening configured to receive a flat wipe connector; and a leaf spring secured within the connector housing and further configured to secure the flat wipe connector within the connector housing, wherein the connector housing further comprises a positive stop feature abutting the turning feature of the leaf spring, and wherein the break feature includes an angled portion and a flat portion such that the angled portion is oriented at an angle relative to a rear section of the leaf spring and the flat portion is generally parallel to the rear section, further wherein the flat portion of the break feature abuts the positive stop feature.

10. The system of claim 9, wherein the connector housing further comprises a first slot and a second slot, the first slot and the second slot being configured to receive respective first and second opposing edges of a leaf spring.

11. The system of claim 10, wherein the first and second slots of the connector housing interact with the leaf spring to exert a force on a curved mid-section of the leaf spring.

12. The system of claim 11, wherein when the leaf spring is inserted into the connector housing, the force moves the deflection feature of the leaf spring downwardly toward the bottom of the connector housing and positions the deflection feature abutting the positive stop feature.

13. The system of claim 9, wherein the positive stop feature is integrally formed with the connector housing.

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