Abstract: A computer terminal keyboard is sealed by a molded elastomeric top cover, shaped to conform to the housing and keys of the keyboard, and a bottom cover shaped to enclose the base of and secure the top cover around its periphery to the keyboard housing. The top cover is shaped to provide a substantially planar surface on the top plate with elevated individual key covers integrally formed in the top cover. Portitons of the top cover extending over the top face and sides of the keyboard housing are formed in a first thickness sufficient to provide a durable covering. Portions of the top cover immediately adjacent and between the individual key covers, and the sides of the key covers, are formed in a reduced, second thickness to allow for flexure as the keys are depressed. The top surface of the top cover is planar so that spilled liquid and debris are easily wiped or brushed away from around and between the key covers.

Abstract: A protective cover or boot for a keyboard array is provided which prevents entry of contaminants, such as water, dust and the like into the interior of the keyboard assembly. A membrane of a resilient material, such as a silicone rubber, is used to form a one-piece cover which extends over the keyboard array as well as the obverse face of the keyboard assembly and, in cooperation with a plate, acts as a seal to totally encapsulate the keyboard assembly. The elastomeric cover is formed as a low-cost material of generally uniform thickness and is molded to a shape so as to cover the top portion of the individual keys as well as extend partially down the side walls thereof so as to be spaced from the deck of the keyboard assembly by a distance which is equal to or greater than the length of travel of the key when actuated.

Abstract: A membrane keyboard is comprised of a dielectric substrate and an overlying deflectable membrane layer separated by a spacer. A plurality of contact poles are located on the dielectric substrate with an electrically conductive common contact area located on the flexible membrane. A portion of the flexible membrane is locally stiffened and, in a preferred embodiment, provided with a ridge extending away from a portion of the membrane towards the contact poles. Upon actuation of the switch, the stiffened portion of the membrane ensures simultaneity of contact between the common contact area on the membrane and the contact poles on the substrate. Preferred embodiments utilize a generally circular ridge in the deflectable membrane cooperating with interdigitated contact poles.

Abstract: Novel composite products formed by bonding a flowable elastomer, such as silicone rubber, to a transparent or translucent silicone rubber preform are described. These products have utility in the field of electromechanical devices such as an illuminated switch or key or as a transparent rubber window permitting view of an underlying display device. The bond between the preformed elastomer and the flowable elastomeric material is improved by post-curing the preform for about 4 hours at about 200.degree. C. prior to contact of the flowable material with the preform. Methods of fabrication of the novel composites are also disclosed.