Keyswitch assembly

A keyswitch assembly comprising:

• a key having four upper guide groove portions;
• a holding member comprising a plate with a central opening therein and four lower guide portions corresponding to said upper guide groove portions;
• a support supporting said key in a first rest position and a second depressed position, comprising four elongated support members with upper and lower ends and a pressure plate, each of said four support members being pivotally secured to a different side of said pressure plate, wherein each of said upper ends is slidingly engaged with one of said upper guide groove portions and each of said lower ends is slidingly engaged with one of said lower guide groove portions;
• and
• a switch causing switching action comprising an electrical contact disposed over said opening of said holding member and under said support, wherein said pressure plate contacts said switch in said first rest position and bears on and compresses said switch in said second depressed position to cause said electrical contact to make an electrical connection.

A keyswitch assembly comprising:

• a key with a front and back surface, said back surface having four upper guide groove portions, each upper guide groove portion comprising a flange spaced from said back surface and defining a groove having an open end and a closed end, each said flange having an inner side surface and extending in a direction approximately 90.degree. from an adjacent flange;
• a holding member comprising a plate with a central opening therein and four lower guide portions
• corresponding to said upper guide portions, each lower guide groove portion comprising a flange spaced from said plate and defining a groove having an open end and a closed end, each said flange having a inner side surface and extending in a direction approximately 90.degree. from an adjacent flange;
• a support mechanism for supporting said key in a first rest position and a second depressed position, comprising four elongated support members, each support member having a body with a hole therein, an outer side surface, an upper end and a lower end, each end having an end pin extending outwardly therefrom, and a quadrilateral pressure plate with outwardly extending pivot pins on each side thereof, wherein each of said pivot pins on said quadrilateral pressure plate is pivotally secured in said holes of said elongated support members, and wherein each upper end is slidingly engaged with an upper guide groove portion, each lower end is slidingly engaged with a lower guide groove portion, and each outer side surface is closely adjacent to each inner side surface of each respective flange;
• and
• a switching member comprising a resilient spring with an electrical contact disposed in said opening of said holding member and below said quadrilateral pressure plate, wherein said quadrilateral pressure plate rests on said resilient spring in said first rest position and compresses said switching member to cause said electrical contact to make an electrical connection in said second depressed position and wherein each of upper ends and said lower ends contacts said closed end of each respective groove in said second depressed position.