Patent Application
20080149469
The present invention relates to the field of electronic controls and more particularly concerns an easily configurable keypad assembly adapted for vehicular controls. The present invention also concerns a kit for assembling such a configurable keypad.
Buttons and switches are essential components of dashboards of boats, industrial equipment, or land vehicles such as RVs, trucks, buses, tractors, etc. With the advent of multiplexing technology, the possibilities for designing and configuring the look and functionality of such dashboards have become practically endless.
Vehicle manufacturers require control components which are practical and versatile. Keypads, in particular, can advantageously provide several controls grouped on a single control component. The particular combination of functions required on a single component may vary depending on the application. For example, a boat manufacturer may offer several possible control configurations for one or different boat models. It is tedious for such a manufacturer to order different keypads, each with its own part number, for each configuration, which implies managing and keeping track of a complex inventory. It is therefore highly preferred to purchase template keypads, each having the same part number, which can then be configured as desired and then provided with markings identifying the function associated with each control.
Different types of configurable keypads are known in the art, but each presents its own drawbacks.
Mechanical switch keypads generally take the shape of individual rubber buttons projecting out of a plastic housing. Identification is provided on the plastic housing, through an adhesive overlay affixed thereon which is provided with appropriate pictograms and may be back lighted. In this case, the pictogram identifying a given control is not on the button itself but besides it, which can lead to confusion.
Membrane keypads are also known in the art. A flexible membrane is directly provided with carbon contacts or integrated dome switches. The membrane is permanently held within a rigid frame. Pictograms or other identification markings may be silk-screened or pad printed on the flexible membrane. One drawback of membrane keypads is that they are not reusable, as the functions are integral to the membrane and the identification markings cannot be changed once made.
For typical silicone rubber keypads, a full silicone rubber skin defining the switching surface is provided over a switching printed circuit board (PCB). Generally, the silicone skin is transparent and provided with a white coat of paint to promote light diffusion, and an opaque overcoat. Customization may be provided by laser etching the pictograms directly into the opaque top coat, which can be an expensive process and the required equipment may not be readily available. Alternatively, identification may be provided through labels insertable into pockets positioned either over or besides each button. The result of this embodiment does not however give a fully professional and aesthetically pleasing appearance.
There is therefore a need for a configurable keypad assembly which alleviates the above-mentioned drawbacks.
According to a first aspect of the invention, there is provided a configurable keypad assembly for use in combination with a rigid fascia overlay. The overlay is provided with identification markings. The keypad assembly includes a configurable keypad circuit provided with a plurality of switches responsive to pressure thereon. The keypad circuit is encased in a flexible sleeve that is shaped to fit over the circuit. The top surface of the sleeve has a number of independently pressable button areas in alignment with the switches, such that any pressure exerted on a given button area activates the switch under it. The assembly also includes securing means for securing the rigid fascia overlay over the button areas. The identification markings on the overlay, once installed, are in alignment with the button areas.
Such an assembly can be easily reconfigured with a different fascia overlay. Consequently, inventories for keypad assemblies can be rationalized as a same basic keypad circuit can be used in several different applications and sold to different clients. A customized overlay can then be installed on the keypad assembly for a specific application or according to a specific client requirement.
In accordance with another embodiment of the present invention, there is also provided a kit for assembling a configurable keypad assembly with a fascia overlay as defined above.
Consequently, the configurable keypad assembly has the flexibility of being distributed to customers with or without the fascia overlay. Furthermore, the keypad assembly is designed in a manner that makes it suitable for environments that require waterproof electronic controls, such as in marine applications.
Other features and advantages of the present invention will be better understood upon reading of preferred embodiments thereof with reference to the appended drawings.
Referring to
The keypad assembly 20 may be used in any context where traditional keypads, such as of the mechanical switching, membrane and rubber types mentioned above are found useful. It is an advantageous aspect of the keypad assembly of the present invention that it may be easily made waterproof, making it particularly adapted for marine applications. Its usefulness is not however limited to such applications and its use could also be contemplated for industrial equipment, or land vehicles such as RVs, trucks, buses, tractors, etc.
The keypad assembly 20 first includes a configurable keypad circuit 22 (see
As shown in
As mentioned above, the flexible sleeve 24 is preferably made of silicone and of a construction similar to that of traditional rubber-type keypad membranes, Alternatively, the sleeve 24 may be made of any other appropriate flexible material such as rubber or any rubber-like material, such as thermoplastic lassoers (TYPE), thermoplastic polyolefins (TPO), and thermoplastic vulcanizates (TPV). In the preferred embodiment, the flexible sleeve 24 is transparent, and is covered with a light diffusing layer such as a coat of white or light paint. An opaque overcoat is further provided over the light diffusing layer. At least a portion of each button area 26, as well as regions of the sleeve 24 dedicated to status indicators, is left free of the opaque overcoat. The overcoat-free regions may either be provided by masking these regions when applying the opaque overcoat, or by applying the overcoat uniformly over the sleeve and subsequently removing portions thereof.
In the preferred embodiment, the flexible sleeve fits snugly around the keypad circuit 22 and its support 44, and silicone joints are provided at their edges for waterproofing the assembly. Waterproofing may be further completed by pouring urethane inside the assembly to surround the PCB.
As shown in
Preferably, the fascia overlay 34 is made of polycarbonate, a combination of polycarbonate and polyester, or any other suitable material or combination of materials. Such fascias are well known and readily available. The identification markings 36 can be silk-screened or pad printed on the fascia overlay 34, such processes being well known and easily accessible to vehicle manufacturers or the like. The identification markings 36 may be pictograms, lettering or any symbol generally allowing the identification of the function of a given switch by its user.
The fascia overlay 34 and flexible sleeve 24 are preferably designed so that the former snugly fits onto the latter. In one embodiment of the securing means mentioned above, the flexible sleeve 24 preferably has a ridge 38 on its top surface following the shape of the fascia overlay 34 to help retain it in place. The ridge 38 is made integral to the sleeve 24. The ridge 38 and the button areas thus define a space for receiving the overlay through a pressfit connection. The fascia overlay is however preferably also secured to the flexible sleeve through an appropriate adhesive. In a particularly advantageous embodiment, an adhering strip 40 is provided on the flexible sleeve 24, preferably in proximity of the button areas 26. The adhering strip 40 can for example be made of acrylic and polycarbonate. In this embodiment, the adhering strip provides a better adherence for traditional fascia materials and adhesives, which can be difficult to retain on the some materials such as silicone.
In the embodiment of
In alternative embodiments, the fascia overlay may be attached to the flexible sleeve through a number of different techniques. For example, one or more small pins, or any other type of fasteners for mechanically fastening the overlay to the sleeve, may be used. In another case, if thermoplastic materials are used for making the sleeve, the overlay may be overmolded onto the sleeve.
It is one advantage of the present invention that the resulting keypad combines the advantages of both rigid and flexible materials. The flexible sleeve is highly deformable and provides a lot of travel, more than traditional membrane keypads. The fascia overlay however provides rigidity in the button areas to increase the effective activation surface. This opens the way to various button geometries and allows to provide three-dimensional contours without limiting the activation surface. The end result is a product which is versatile and provides more freedom of design than either types of traditional keypads.
As mentioned above, as shown in
According to other embodiments of the invention, each button area 26 may have its own fascia overlay 34. In a first such embodiment, the identification markings 36 are directly formed into the fascia overlays 34. In a second such embodiment, the identification markings 36 are masked on the fascia overlay 34, making the entire button areas 26 appear lighted except in regions where the marking are made.
As mentioned previously, in accordance with another embodiment of the present invention, there is also provided a kit for assembling one of the above-mentioned configurable keypad assemblies with a fascia overlay. Kits can be provided for keypad assemblies requiring either a single fascia overlay to be installed over the whole keypad or a plurality of smaller overlays to be installed over corresponding button areas. Therefore, the keypad assembly has the flexibility of being kept in inventory or eventually distributed to customers without the overlays or as kits with different overlays. It will be understood that in this context the customer is not necessarily the end user but may for example be a vehicle manufacturer wishing to incorporate such keypads in its own products.
Of course, numerous modifications could be made to the embodiments above without departing from the scope of the present invention.
This application claims priority to U.S. provisional patent application Ser. No. 60/855,402, titled, “Configurable Keypad with Fascia Overlay,” filed Oct. 31, 2006, the disclosure of which is hereby incorporated by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 60855402 | Oct 2006 | US |
