Membrane dome switch with tactile feel regulator shim

Abstract

A membrane dome switch is disclosed which includes a tactile feel regulator shim to provide an enhanced and consistent tactile feedback in response to fingertip switch depression. The membrane dome switch includes a conductive domed spring member mounted in a sandwich or laminant array between an underlying circuit layer having a conductive circuit pattern thereon and an overlying shield layer. Fingertip pressure applied to the shield layer is effective to deform the spring member to momentarily close a circuit path on the circuit layer. The tactile feel shim is interposed between the spring member and the overlying shield layer, and functions to provide improved tactile feedback sensation during switch operation. In the preferred form, a plurality of domed spring members are provided for selective fingertip depression to control and/or program an electronic device such as a medication infusion pump, and the regulator shim comprises a multi-legged web having individual legs defining a plurality of foot pads positioned for respectively overlying the domed spring members.