Patent Application
20050048822
The present invention relates to modular clocksprings used in automobiles that allow rotating members to maintain a continuous electrical connection to stationary members. In particular, the modular clockspring comprises multiple modules that may be individually modified without affecting the function of the other modules, so that specific modules may be modified to be used within different automobiles without having to redesign the entire clockspring.
While the present invention may have multiple applications, the most prevalent is for use in automobiles. An increasing number of automobiles have airbag crash systems. An airbag is typically located on the steering wheel facing the driver. The airbag must be in continuous electrical connection with sensors in the car body which provide an electrical signal to the airbag crash assembly which instantly inflates the airbag in the event of a crash. Clocksprings are found in virtually every vehicle to electrically connect rotating devices in the steering column to stationary components in other parts of the vehicle.
Because of the large number of types and models of vehicles, oftentimes, minor modifications are necessary to the clockspring so that it matches the requirements of the corresponding vehicle. Usually, these differences are in mounting styles, connector styles, or the number of circuits within the clockspring. Differences in any one of these features up to now has required a complete redesign of the entire clockspring, resulting in higher costs and longer lead times for the production of the clockspring.
The present invention provides a modular clockspring that may be used in different vehicles, by changing any one of the modules on the clockspring to meet the particular vehicle requirements. Clocksprings having multiple modules are not new in the art. U.S. Pat. Nos. 5,226,831 to Horiuchi and 5,286,219 to Ueno et al. disclose such clocksprings. However, these clocksprings have multiple modules to facilitate their assembly, and have generally been designed to limit the number of modules in order to keep the assembly process simple. For example, Horiuchi states in the Summary of the Invention, that an object of the invention is to “permit easy installation of the flat cable connecting portions to cases and which has [a] minimized number of required parts.” The prior art clocksprings were not designed with the intent of having modules capable of being easily modified to accommodate specific functional and design needs of multiple vehicles.
The present invention is directed to a modular clockspring to be used in automobile steering columns that allow modular parts of the clockspring to be modified without the need to alter the design of the entire clockspring. The clockspring is made up of at least six modules, a cover module, a housing module, an inner diameter (ID) connector module, an outer diameter (OD) connector module, a locking module, and a flat electrical cable module.
The housing module and cover module are mated to form an enclosure for the flat cable module, with the flat cable module being wound around a hub located on the cover module. The inner and outer ends of the flat electrical cable are secured to the ID connector module and the OD connector module, respectively. The ID connector module extends through an opening in the cover module for attachment to electrical components within a steering column. The OD connector module is positioned around an outside circumferential edge of the housing for connection to other stationary components in the vehicle. The locking module engages the OD connector module to lock the OD connector module to the housing module.
The modular nature of the clockspring allows a single generic clockspring to be used in various steering columns. Minor differences in mounting styles, connector styles or the number of circuits within the differing steering columns can be accommodated with changes to the relevant modules without having to redesign the entire clockspring. For example, variations in the type of connector used in vehicles can be accommodated by modifying either the ID or OD connector module, without altering the remaining modules of the clockspring.
Therefore, it is an object of the invention to provide a modular clockspring which allows various modules thereon to be modified to meet the specific requirements of a vehicle, without having to modify the remaining modules of the clockspring. It is further an object of the invention to identify those modules which vary most frequently between systems and isolate those modules in the clockspring so that they may be modified without affecting the other modules of the clockspring. It is yet a further object of the invention to provide a modular clockspring that may be redesigned in a simple and efficient manner, thereby reducing the overall cost of producing the clockspring.
With these and other objects, advantages and features of the invention that may become hereinafter apparent, the nature of the invention may be more clearly understood by reference to the following detailed description of the invention, the appended claims and to the several drawings attached herein.
Referring now in detail to the drawings,
The flat cable 6 is of the type that is well know in the art to be used with clocksprings. The flat cable 6 has an inner end 7 and an outer end 9 attached to the ID connector module 8 and the OD connector module 10, respectively. Although connection to the ID and OD connector modules 8 and 10 can be accomplished in one of any number of ways, a preferred method, as shown in
The several modules of the clockspring and how they fit with one another will now be explained. The ID connector module 8 is inserted through an opening 18 in the cover 4. The cover 4 has a hub 20, as best shown in
Referring now to
After the hub 20 is inserted though the outer section 26 of the slot, it is slid towards the center of the housing 2, into the inner section 28. The flanges 22 engage the circular edge 23 of the housing inner section 28, thus preventing the cover 4 from separating from the housing 2. The cover plate 4 rests on top of the housing walls 5 and seals the interior of the housing 2.
Reference is now made to
Now, referring to
The modular clockspring of the present invention has several independent modules, in particular the ID connector module 8, the OD connector module 10, the cover 4, the housing 2, the flat electrical cable 6 and the locking module 12, so that typical changes in system requirements do not necessitate a complete redesign of the clockspring 1. For example, a change in the mounting style would only require a change in the housing structure, or a change in the number of circuits would require only changing the type of flat cable used or the ID and OD connector modules.
The clockspring of the present invention has been designed so that specific modules thereon may be altered without affecting the remaining modules of the clockspring. This allows manufacturers the flexibility to vary specific modules to meet the needs of different systems without costly redesigns. Furthermore, this clockspring can serve as the base for a line of clocksprings to serve a variety of different vehicle models because various clocksprings would have several common modules. This would reduce the manufacturing and inventory costs as there are less parts to design, manufacture and store.
Although only preferred embodiments are specifically illustrated and described herein, it will be appreciated that many modifications and variations of the present invention are possible in light of the above teachings and within the purview of the appended claims without departing from the spirit and intended scope of the invention.
