Key assembly

Claim 2

A key assembly comprising a base; a manually operable key secured to, and mounted above said base by, a resilient key mat having an upstanding wall, the key having a depending neck and being moveable against the resilience of said upstanding wall towards said base; a guide assembly extending between said base and said key to guide movement of said key; a membrane supported on said base and carrying a pair of electrically insulated first contacts, each of said first contacts of the pair being connected to a respective electrical track supported on said membrane and extending to a connection location; and a second contact provided on an underside of one of said depending neck and a portion of said key mat in contact with said depending neck and having a size and position such that movement of said key towards said base causes said second contact to engage both of said first contacts and thereby electrically connect said first contacts.

Claim 3

An assembly according to claim 1, wherein said first contacts are spaced about an arc, said second contact extending along said arc.

Claim 4

An assembly according to claim 2, wherein said second contact forms a closed curve.

Claim 5

An assembly according to claim 3, wherein said closed curve is a circle.

Claim 6

An assembly according to claim 2, wherein said first contacts are positioned about said guide assembly.

Claim 7

An assembly according to claim 1, wherein said tracks are provided on both sides of said membrane.

Claim 8

An assembly according to claim 1, wherein said resilient key mat has an upper, cylindrical section integrally formed with said upstanding wall and fitted to said depending neck, said depending neck being positioned on an underside of said key.

Claim 9

An assembly according to claim 1, wherein a part of said membrane carrying said first contacts overlies a recess in said base whereby movement of the key towards the base causes the membrane to be pushed against said resilient key mat into the recess.

Claim 10

An assembly according to claim 8, wherein said recess extends around said guide assembly.

Claim 11

An assembly according to claim 1, wherein said guide assembly comprises a cooperating finger and socket, one on said base and the other on said key.

Claim 12

An assembly according to claim 10, wherein said finger is mounted on an underside of said key and said socket is provided in said base.

Claim 13

An assembly according to claim 10, wherein said finger and socket each have a cruciform cross-section.

Claim 14

An assembly according to claim 10, wherein one of said finger and said socket has a laterally extending lug and the other a resilient tab such that, on insertion of said finger into said socket, said lug snaps over said tab to retain the key on said guide assembly.

Claim 15

An assembly according to claim 1, wherein said second contact is provided on an underside of said depending neck.

Claim 16

A key pad having a plurality of key assemblies, each key assembly comprising a base; a manually operable key secured to, and mounted above said base by, a resilient key mat having an upstanding wall, the key having a depending neck and being moveable against the resilience of said upstanding wall towards said base; a guide assembly extending between said base and said key to guide movement of said key; a membrane supported on said base and carrying a pair of electrically insulated first contacts, each of said first contacts of the pair being connected to a respective electrical track supported on said membrane and extending to a connection location; and a second contact provided on an underside of one of said depending neck and a portion of said key mat in contact with said depending neck and having a size and position such that movement of said key towards said base causes said second contact to engage both of said first contacts and thereby electrically connected said first contacts.

Claim 17

A key pad having a plurality of key assemblies, each key assembly comprising a base; a manually operable key secured to, and mounted above said base by, a resilient key mat having an upstanding wall, the key having a depending neck and being moveable against the resilience of said upstanding wall towards said base; a guide assembly extending between said base and said key to guide movement of said key; a membrane supported on said base and carrying a pair of electrically insulated first contacts, each of said first contacts of the pair being connected to a respective electrical track supported on said membrane and extending to a connection location; and a second contact provided on an underside of one of said depending neck and a portion of said key mat in contact with said depending neck and having a size and position such that movement of said key towards said base causes said second contact to engage both of said first contacts and thereby electrically connected said first contacts.

Claim 18

A key pad according to claim 15, wherein said first contacts of each of said keys are provided on a common membrane.

Claim 19

A key pad according to claim 15, wherein said resilient key mats of each key are formed from a common resilient key mat.

Claim 20

A key pad according to claim 15, wherein said second contact is provided on an underside of said depending neck.

Claim 21

Computing equipment including a processor and a key pad, the key pad having a plurality of key assemblies, each key assembly comprising a base; a manually operable key secured to, and mounted above said base by, a resilient key mat having an upstanding wall, the key having a depending neck and being moveable against the resilience of said upstanding wall towards said base; a guide assembly extending between said base and said key to guide movement of said key; a membrane supported on said base and carrying a pair of electrically insulated first contacts, each of said first contacts of the pair being connected to a respective electrical track supported on said membrane and extending to a connection location; and a second contact provided on an underside of one of said depending neck and a portion of said key mat in contact with said depending neck and having a size and position such that movement of said key towards said base causes said second contact to engage both of said first contacts and thereby electrically connect said first contacts, said key pad being coupled via the tracks to said processor.

Claim 22

Computing equipment including a processor and a key pad, the key pad having a plurality of key assemblies, each key assembly comprising a base; a manually operable key secured to, and mounted above said base by, a resilient key mat having an upstanding wall, the key having a depending neck and being moveable against the resilience of said upstanding wall towards said base; a guide assembly extending between said base and said key to guide movement of said key; a membrane supported on said base and carrying a pair of electrically insulated first contacts, each of said first contacts of the pair being connected to a respective electrical track supported on said membrane and extending to a connection location; and a second contact provided on an underside of one of said depending neck and a portion of said key mat in contact with said depending neck and having a size and position such that movement of said key towards said base causes said second contact to engage both of said first contacts and thereby electrically connect said first contacts, said key pad being coupled via the tracks to said processor.

Claim 23

Computing equipment according to claim 19, wherein said second contact is provided on an underside of said depending neck.