Abstract: An apparatus for printing keyboard keycaps includes a fixture for holding multiple keycaps in an essentially keyboard profile. The fixture supports the keycaps in separately movable segments, each having multiple keycaps. The spearately movable segments are movable from an essentially keyboard profile into an essentially planar printing profile. The printing apparatus includes an air inflatable heated bladder positioned to apply heat and pressure to a legend carrying medium positioned upon the keycaps to transfer the legends from the medium to the individual keycaps.

Abstract: An auxiliary bearing for use in a keyboard to prevent binding of keys having irregularly-shaped keycaps. The irregular keycap is mounted on a plunger which reciprocates in a main switch housing. The switch housing is attached to the keyboard. The keycap also has a coupler attached to its underside. The coupler engages a bearing in the form of a sleeve which supports the coupler along a portion of its length sufficient to preclude the coupler from tilting in the sleeve. The bearing member is mounted on an auxiliary housing which in turn is attached to the keyboard. The connection of the bearing to the auxiliary housing permits the bearing to shift laterally on the housing to permit alignment of the coupler and sleeve despite variations in the auxiliary housing location and the keycap location. But the bearing is prevented from tilting or skewing in the auxiliary housing by a set of cooperating hooks on the housing and bearing.

Abstract: A keyboard switch which is used in combination with a membrane switch array includes a housing adapted to be positioned on the membrane switch array. There is an upright opening in the housing and a plunger is reciprocal in the housing opening. There is a spring urging said plunger outwardly in said opening and there is an actuator lever pivotally mounted on said housing and positioned for engagement by said plunger. Inward movement of said plunger through a given distance causes the application of a switch closing force by said lever on the underlying switch array. The geometry of the actuator lever-plunger interface can be arranged for linear application of the switch closing force or sudden application of said force. Sudden application of the switch closing force provides a tactile feedback.

Abstract: A switch for use in keyboards and the like has a housing mounted on a baseplate, with a set of electrical contacts associated with the housing. There is a reciprocative plunger mounted in the housing. An actuator is operatively connected to the electrical contacts for closing them in response to movement of the plunger. A first spring is located between the plunger and the actuator biasing these components apart. A reciprocative coupler is mounted in the housing, and is engageable with the plunger during a first portion of the plunger stroke. The coupler includes a blocking tang which engages the actuator during the first portion of the plunger stroke to prevent movement of the actuator. A second spring is located between the coupler and the housing to bias the coupler upwardly, this force being also transferred to the plunger when the coupler and plunger are engaged.

Abstract: A keyboard has a space bar centrally mounted on a plunger and supported at its ends by a torsion rod. The torsion rod has crank arms at its ends which are connected to the space bar and serve to distribute the actuating force on the space bar so that the plunger will move smoothly up and down and not bind. An attachment element in the nature of a yoke is provided for connecting the crank arms of the torsion rod to the space bar. A spring connected to the space bar flexibly engages the crank arm. The attachment element accommodates the natural, arcuate motion of the crank arm while simultaneously maintaining engagement with the crank arm to secure the space bar to the torsion rod and prevent the space bar from rattling or vibrating.

Abstract: A membrane switch has a substrate, a flexible membrane and an intervening spacer. Switch contacts are formed on the top surface of the substrate and the underside of the membrane in spaced, facing relation. A hole in the spacer in register with the switch contacts allows the contacts to move together in response to pressure exerted on the membrane. An auxiliary electrical device can be incorporated into the membrane switch through an opening in the membrane which provides access to a current supply circuit which is formed on the top surface of the spacer. The auxiliary device is held in place in electrical contact with the current supply circuit on the spacer. A pair of current supply leads provide electrical power to the current supply circuit. In a preferred embodiment at least one of the current supply leads is formed on the underside of the membrane, in contact with the current supply circuit and also connected to the switch contact on the membrane.

Abstract: This invention relates to a method of fabricating a membrane switch of the type having a substrate, a flexible membrane, electrical conductors formed on the membrane and substrate, and an intervening spacer between the sets of conductors. The conductors include a plurality of switch sites which are in facing relation to define a specific switch. The spacer means comprises a plurality of individual spacer areas which are located remote from the switch sites. The manufacturing method uses a multiple pass screen printing operation. During the first pass a set of conductors is formed from conductive ink on either the membrane or substrate. Also, during the first screening pass a first layer of the spacer areas is formed from the same conductive material as the set of conductors. On subsequent screening passes additional layers are deposited on the spacer areas to build up the thickness of the areas so that the spacer thickness is greater than that of the conductors.

Abstract: A keyboard has a space bar centrally mounted on a plunger and supported at its ends by a torsion rod. The torsion rod has crank arms at its ends which are connected to the space bar and serve to distribute the actuating force on the space bar so that the plunger will move smoothly up and down and not bind. An attachment element in the nature of a yoke is provided for connecting the crank arms of the torsion rod to the space bar. A spring connected to the space bar flexibly engages the crank arm. The attachment element accommodates the natural, arcuate motion of the crank arm while simultaneously maintaining engagement with the crank arm to secure the space bar to the torsion rod and prevent the space bar from rattling or vibrating.