Patent Application
20170250477
Embodiments of the subject matter described herein relate generally to electrical connectors and terminals. More particularly, embodiments of the subject matter relate to an electrical terminal having an integrated feature that facilitates automated confirmation of proper installation of the electrical terminal.
The prior art is replete with electrical connectors, conductive terminals, wire designs, and cable designs. An eyelet or spade terminal can be physically and electrically coupled to the end of conductive wire or cable, wherein the terminal is designed to mate with a conductive mounting post or similar feature. For example, a vehicle may have one or more threaded mounting posts that correspond to chassis ground (or to any designated voltage level). A threaded mounting post is shaped and sized to receive a conductive terminal and a threaded fastener, which is tightened overlying the terminal. When properly installed, the terminal remains clamped between a base/shoulder of the mounting post and the threaded fastener. The fastener is threaded onto the terminal to achieve a secure physical and electrical connection.
In accordance with a typical installation process, the amount of torque applied to the threaded fastener is measured as the fastener is tightened onto the threaded mounting post, and the automated tool is stopped when a threshold torque measurement is reached. There may be situations, however, when the threshold torque measurement is achieved even though the electrical terminal is not properly installed and secured to the mounting post. For example, if the threads of the fastener or the mounting post are stripped, then the threshold torque measurement can be reached prematurely. As another example, if the terminal is improperly placed onto the mounting post, or if the fastener is threaded onto the mounting post without installing the terminal first, then the threshold torque measurement can be reached when the fastener reaches the bottom of the mounting post.
Accordingly, it is desirable to have an electrical terminal design and a related installation methodology that addresses the situations mentioned above. In addition, it is desirable to have an electrical terminal design that facilitates an automated and self-checking installation process. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.
Disclosed herein is a terminal for an electrical conductor. An exemplary embodiment of the terminal includes a primary base structure formed of an electrically conductive material, and a deformable feature extending above the primary base structure. The primary base structure includes a coupling feature to receive a mounting post. The deformable feature is compressible in response to installation of a fastener that clamps the terminal between a shoulder of the mounting post and the fastener. The deformable feature has mechanical properties and characteristics such that force required to compress the deformable feature varies as a function of height of the deformable feature.
Also disclosed herein is an electrical assembly. An exemplary embodiment of the electrical assembly includes an electrically conductive threaded mounting post having a contact surface, a threaded fastener that mates with the threaded mounting post, and a terminal for an electrical conductor. The terminal has a deformable feature that compresses when the threaded fastener is installed to clamp the terminal between the contact surface and the threaded fastener. The deformable feature has mechanical properties and characteristics such that torque required to compress the deformable feature increases during installation of the threaded fastener.
Also disclosed herein is a method of checking an installation of a terminal for an electrical conductor on an electrically conductive threaded mounting post having a contact surface for the terminal. An exemplary embodiment of the method involves coupling the terminal to the threaded mounting post, wherein the terminal has a deformable feature that compresses when a threaded fastener is installed to clamp the terminal between the contact surface and the threaded fastener, and wherein the deformable feature has mechanical properties and characteristics such that torque required to tighten the threaded fastener increases as the deformable feature compresses. The method continues by installing the threaded fastener onto the threaded mounting post and overlying the terminal, and by measuring, with a computer-based torque measurement tool, torque associated with installation of the threaded fastener onto the threaded mounting post until a final torque value is reached. The final torque value represents a tightened state of the fastener. The method continues by analyzing, with the computer-based torque measurement tool, the measured torque to confirm presence of the terminal between the threaded fastener and the contact surface.
This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the detailed description. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.
A more complete understanding of the subject matter may be derived by referring to the detailed description and claims when considered in conjunction with the following figures, wherein like reference numbers refer to similar elements throughout the figures.
The following detailed description is merely illustrative in nature and is not intended to limit the embodiments of the subject matter or the application and uses of such embodiments. As used herein, the word “exemplary” means “serving as an example, instance, or illustration.” Any implementation described herein as exemplary is not necessarily to be construed as preferred or advantageous over other implementations. Furthermore, there is no intention to be bound by any expressed or implied theory presented in the preceding technical field, background, brief summary or the following detailed description.
Techniques and technologies may be described herein in terms of functional and/or logical block components, and with reference to symbolic representations of operations, processing tasks, and functions that may be performed by various computing components or devices. Such operations, tasks, and functions are sometimes referred to as being computer-executed, computerized, software-implemented, or computer-implemented. When implemented in software or firmware, various elements of the systems described herein are essentially the code segments or instructions that perform the various tasks. In certain embodiments, the program or code segments are stored in a tangible processor-readable medium, which may include any medium that can store or transfer information. Examples of a non-transitory and processor-readable medium include an electronic circuit, a semiconductor memory device, a ROM, a flash memory, an erasable ROM (EROM), a floppy diskette, a CD-ROM, an optical disk, a hard disk, or the like.
The mounting post 100 extends above a support structure 110, which may be an electrically conductive panel, bar, bus, frame, or the like. In certain non-limiting embodiments, the support structure 110 is an electrically conductive part of a vehicle having a chassis ground voltage potential. The primary section of the mounting post 100 is threaded to mate with and receive the fastener 104. A lower section of the mounting post 100 includes an electrically conductive shoulder 112, base, or contact surface that is shaped, sized, and configured to provide a good platform to receive the electrical terminal 102. In certain embodiments, the mounting post 100 is formed from an electrically conductive material, such as steel.
For the exemplary embodiment shown throughout the figures, the electrical terminal 102 includes an eyelet structure having a hole that receives the mounting post 100. In alternative embodiments, the electrical terminal 102 can include a spade structure, a prong structure, a U-shaped structure, a C-shaped structure, or the like, wherein the structure is shaped and sized to accommodate the mounting post 100.
The somewhat flat initial portion 202 of the plot 200 corresponds to the period of time before the threaded fastener experiences any clamping resistance. In other words, the threaded fastener is freely spinning with little to no resistance during the initial portion 202 of the plot 200. The abrupt spike 204 in the plot 200 corresponds to the very brief period of time during which the threaded fastener clamps the electrical terminal against the shoulder or contact surface of the mounting post. Notably, the measured torque quickly rises to almost 10 N-m at this point. Thereafter, the plot 200 exhibits a dip before rising again; this behavior is caused by a change in the rotational speed of the tool. Although not always required, the rotational speed of the tool can be reduced after the measured torque reaches a threshold value, such that the desired final torque value (which is about 10 N-m for this example) can be reached in a gradual and accurate manner.
The plot 200 demonstrates why it can be difficult to detect an improperly installed electrical terminal in certain situations. For example, if the threads of the mounting post and/or the fastener are stripped or are otherwise compromised, then the measured torque can rapidly increase or spike up (as shown in
An electrical terminal of the type described below includes one or more deformable, compressible, and/or crushable features that allow a torque measurement tool to automatically and reliably detect whether or not the electrical terminal is properly installed and clamped onto the mounting post. In certain embodiments, the deformable feature of the terminal is destructively deformed in response to installing the threaded fastener onto the mounting post. The deformable feature(s) result in measured installation torque values that vary in a detectable and predictable manner as the threaded fastener is tightened atop the terminal. The torque profile of a properly installed terminal is detectably different than the torque profile of an improperly installed terminal. Accordingly, the torque data obtained by the tool can be easily analyzed to determine and report the installation status of the terminal.
The primary base structure 304 includes a major contact surface 312 that is relatively flat and straight. In this regard, the primary base structure 304 resembles a flat donut-shaped washer or an eyelet structure. The coupling feature 308 for this embodiment is realized as a hole formed in the primary base structure 304. The hole is shaped and sized in accordance with the mounting post to which the electrical terminal 300 is coupled.
The deformable feature 310 can be realized as a tab or a flap that is integrally formed in the primary base structure 304. As shown in
The deformable feature 310 is compressible in response to the installation of the fastener, which clamps the terminal 300 between the shoulder or contact surface of the mounting post and the fastener. More specifically, the deformable feature 310 is designed to have certain predictable mechanical properties and characteristics such that the amount of force (or torque) required to compress the deformable feature 310 varies as a function of the height of the deformable feature 310, relative to the major contact surface 312. In certain embodiments, the amount of force or torque required to compress the deformable feature 310 increases as the height of the deformable feature 310 decreases. Accordingly, the force or torque required to compress the deformable feature can be applied by threading the fastener onto the mounting post. Moreover, the amount of force/torque applied and measured by the installation tool increases as the threaded fastener crushes the deformable feature, until a final threshold torque value has been reached. For this reason, the output of the torque measurement tool indicates whether or not the terminal is present between the contact surface of the mounting post and the fastener during installation of the fastener onto the mounting post.
It should be appreciated that other deformable or compressible features can be implemented in an electrical terminal, and that the variations described in detail herein are not exhaustive or limiting. For example, the electrical terminal can be fabricated with a relatively flat base structure that can be compressed by the fastener. This behavior can be achieved using multiple layers of different materials, a composite structure, or the like. As another implementation, the base structure of the electrical terminal can be manufactured with a “waffle” structure having support members with adjacent cavities. As yet another example, the base structure of the electrical terminal can be fabricated with a wavy or curved profile that bends up and down relative to the direction of force as applied by the fastener.
The somewhat flat initial portion 702 of the plot 700 corresponds to the period of time before the threaded fastener makes contact with the protruding deformable feature(s) of the terminal. In other words, the threaded fastener is freely spinning with little to no resistance during the initial portion 702 of the plot 700. Thereafter, the measured torque increases over time as the fastener continues to be threaded onto the mounting post. The sloped region 704 of the plot 700 is discernable from about 300 milliseconds to about 1050 milliseconds. Notably, the measured torque rises in a somewhat gradual and consistent manner until it reaches the endpoint 706 of about 10 N-m. In contrast to the spike 204 shown in
The process 800 may begin by coupling a deformable electrical terminal to a threaded mounting post (task 802), wherein the terminal has the mechanical properties and characteristics described above.
The torque measurement tool and/or a suitably configured computer-based system analyzes the measured torque data to confirm whether or not the terminal was properly installed (task 808). For the exemplary embodiment described here, task 808 confirms the presence or absence of the terminal between the threaded fastener and the contact surface of the mounting post. As explained above with reference to
If the process 800 determines that the electrical terminal was properly installed (the “Yes” branch of query task 810), then it proceeds by generating an output that indicates proper installation of the terminal (task 812). The output can be provided in any suitable format, such as a displayed or printed report, chart, graph, message, alert, or the like. As another example, the output can be associated with the activation of an indicator light or sound. In some implementations, task 812 can be optional such that no action is taken and no output is generated in response to a proper and successful installation.
If, however, the process 800 determines that the electrical terminal was not properly installed (the “No” branch of query task 810), then it continues by generating an output that indicates a potentially improper installation of the terminal (task 814). As explained above, task 814 can be performed when the measured torque data is inconsistent with an expected torque profile that corresponds to a properly installed terminal. The output generated at task 814 can be provided in any suitable format, such as a displayed or printed report, chart, graph, message, alert, or the like. For example, the process 800 can generate an alarm or alert message (task 816) when the measured torque data is inconsistent with the expected torque profile. In some situations, the process 800 halts the assembly process (task 818) if it determines that the electrical terminal was not properly installed. Halting the assembly process may be desirable in certain situations to allow inspection of the electrical terminal, mounting post, and/or fastener before continuing the assembly of the particular system, device, vehicle, or product. In this regard, task 818 can be automatically initiated by the process 800 or it can be executed by a human operator.
While at least one exemplary embodiment has been presented in the foregoing detailed description, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or embodiments described herein are not intended to limit the scope, applicability, or configuration of the claimed subject matter in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing the described embodiment or embodiments. It should be understood that various changes can be made in the function and arrangement of elements without departing from the scope defined by the claims, which includes known equivalents and foreseeable equivalents at the time of filing this patent application.
