Keypad assembly

An assembly for a keypad, comprising:

• a substrate having a plurality of electrical-contact regions, each of the electrical-contact regions being defined by a first electrical terminal and a second electrical terminal wherein at least one of said electrical-contact regions has a first electrical terminal having at least first and second electrically connected portions and a second electrical terminal having at least first and second electrically connected portions;
• an array of domed contact elements, each of the domed contact elements being mounted to confront a corresponding one of said electrical-contact regions and overlie a corresponding one of a plurality of apertures;
• an insulating layer disposed between the substrate and the domed contact elements and including plural ones of said apertures arranged in one of the plurality of possible configurations, each of said apertures corresponding to one of said electrical-contact regions and exposing portions of the first and second electrical terminals of corresponding ones of said electrical-contact regions,
• each of said domed contact elements being depressible from a first natural bias position to a second distorted position in which a summit portion of said domed contact element passes through said corresponding one of said apertures to contact said corresponding one of said electrical-contact regions, thereby to establish electrical connection between the first and second electrical terminals of the corresponding one of said electrical-contact regions,
• wherein the first and second electrical terminals of the electrical-contact regions are arranged, so that for a first configuration of said apertures, the first electrically connected portions of the first and second electrical terminals of each of said electrical-contact regions are electrically connected on depression of a corresponding one of said domed elements and so that for a second configuration of said apertures in which at least one of said apertures and corresponding domed contact element have been re-positioned, the second electrically connected portions of the first and second electrical terminals of the electrical-contact regions corresponding to the re-positioned domed contact element are electrically connected on depression of the repositioned domed contact element.

Apparatus comprising:

• first and second assemblies for a keypad, using first and second substrates of a common design,
• wherein each of the substrates has a plurality of electrical-contact regions, each of the regions being defined by a first electrical terminal and a second electrical terminal where at least one of the electrical-contact regions has an area greater than an area enclosed by a footprint of a corresponding one of a plurality of domed contact elements in the first and second assemblies,
• wherein said first assembly comprises:
• the first substrate,
• an array of said domed contact elements in a first configuration, each of the domed contact elements being mounted to confront a corresponding one of the electrical-contact regions of the first substrate and overlie a corresponding one of a plurality of apertures,
• an insulating layer disposed between the first substrate and the domed contact elements and including a plurality of said apertures arranged in the first configuration, each of said apertures corresponding to one of the electrical-contact regions,
• each of the domed contact element being depressible from a first natural bias position to a second distorted position in which a summit portion of each of the dome contact elements passes through a corresponding one of the apertures to contact a corresponding one of the electrical-contact regions, thereby to establish electrical connection between the first and second electrical terminals of the corresponding one of the electrical-contact regions, and
• wherein said second assembly comprises:
• the second substrate,
• an array of said domed contact elements in a second configuration, each of the domed contact elements being mounted to confront a corresponding one of the electrical-contact regions of the second substrate and overlie a corresponding one of a plurality of apertures,
• an insulating layer disposed between the second substrate and the domed contact elements and including a plurality of said apertures arranged in the second configuration, each of said apertures corresponding to one of the electrical-contact regions,
• each of the domed contact elements being depressible from a first natural bias position to a second distorted position in which a summit portion of the domed contact element passes through a corresponding one of the apertures to contact a corresponding one of the electrical-contact regions, thereby to establish electrical connection between the first and second electrical terminals of the corresponding one of the electrical-contact regions.

A method of constructing assemblies for keypads with different key layouts using substrates each having a same pattern of electrical-contact regions formed thereon and domed contact elements, the method comprising the steps of:

• (i) selecting a first design of the key layouts;
• (ii) providing a first insulating layer having a plurality of apertures dependent on the first design of the key layouts;
• (iii) mounting the domed contact elements to confront corresponding ones of said electrical-contact regions of a first of said substrates with the first insulating layer disposed therebetween, each of said plurality of apertures being in register with one of said domed contact elements, thereby to produce an assembly having the first design of the key layouts;
• (iv) selecting a second design of the key layouts, the second design of the key layouts being different from the first design of the key layouts;
• (v) providing a second insulating layer having a plurality of apertures dependent on the second design of the key layouts;
• and
• (vi) mounting the domed contact elements to confront corresponding ones of said electrical-contact regions of a second of said substrates with the second insulating layer disposed therebetween, each of said apertures of said second layer being in register with one of said domed contact elements, thereby to produce an assembly having the second design of the key layouts.

An assembly for a keypad, comprising:

• a substrate having a plurality of electrical-contact regions, each being defined by a first electrical terminal and a second electrical terminal;
• an array of domed contact elements, the domed contact elements being mounted to confront a corresponding one of said electrical-contact regions and overlie only a portion thereof;
• and
• an insulating layer disposed between the substrate and the domed contact elements and including a plurality of apertures, each of said apertures corresponding to one of said electrical-contact regions,
• wherein each of the domed contact elements being depressible from a first natural bias position to a second distorted position in which a summit portion of each of the domed contact elements passes through a corresponding one of the apertures to contact a corresponding one of the electrical-contact regions, thereby to establish electrical connection between the first and second electrical terminals of the corresponding one of the electrical-contact regions.