Key pad with foam maintained contact gap - has underside contact on top pressure layer separated from base contact by collapsible foam sides

摘要

Keypad press switches use a top cover elasticised material, (PETP), metallised on the underside and with foam spacers between each switch contact area. The press buttons(D) are marked and spaced along the top cover (1) which is overall coated on the underside with the metal contact material (2). The base (4) is a rigid material with various switch contacts (5) on its upper side. The top (1) and base (4) are spaced apart by a foam material (3) which can partially collapse when an individual button is pressed. Switch contact is made across an insulating gap (6) maintained by the foam material (3) so that the underside contact (2) of the top makes with the base contact (5). The foam material (3) has cutout sections to align with the press button positions (D), and is an insulator material.