Amp LLC

Kazutoyo Fukukura

William J Lynn

Richard A Martinez

Membrane type circuit comprises an insulating support having terminal sites thereon and circuit conductors extending between and among the terminal sites. A tail extends from the support and the conductors extend onto the tail and have output terminals on the tail. The tail is folded so that the output terminals on each side of the fold line are against each other and are connected to each other. Each pair of conductors which extends from two opposed output terminals are therefore a dual conductor. This arrangement simplifies circuit design and avoids the need for crossovers in many circumstances.

Membrane type circuit having improved tail

Key switch assembly comprises a frame and a plunger in the frame which is movable from an extended position to a depressed position to close a switch. A one piece member is provided which serves as both a return spring for the plunger and an actuator for closing the switch when the plunger is depressed. The one piece member has a force-receiving portion which is against the end of the plunger. The return spring and the actuator are integral with, and extend from, the force-receiving portion.

Key switch having an actuator integral with the return spring

Membrane switch assembly comprises a substrate, a separator, and a flexible membrane which is opposed to the substrate. Pairs of switch electrodes are provided on the substrate and commoning conductors are provided on the membrane so that flexure of the membrane against the substrate electrically commons the switch electrodes and closes the switch. The commoning conductor comprises two separate commoning pads which are connected by a bridging conductor on the membrane that extends circuitously between the commoning pads. There is a passageway between the commoning pads which is opposed to the passageway between the switch electrodes on the substrate. A circuit conductor can be provided on the substrate extending between the switch electrodes and this circuit conductor will not be contacted by the commoning conductor on the membrane when the switch is closed.

Membrane switch having crossing circuit conductors

Keyboard switch assembly comprises first and second insulating supports having opposed spaced-apart first and second surfaces. The first support is a flexible film and has circuit conductors on the first surface thereof which extend to switch sites. Each switch site has a pair of spaced-apart switch electrodes. The second support is a rigid one piece molding having a bezel which surrounds a sunken surface. The first surface of the first support is disposed against the sunken surface. The sunken surface has recesses therein at the switch sites and the floors of the recesses are covered with conductive material such as conductive ink. The floors of the recesses are the second surface. A switch at a switch site is closed by pressing on the first support so that spaced-apart electrodes both contact the conductive material on the floor of the associated recess in the sunken surface of the second support.

Keyboard switch having integral bezel

Encoded keyboard switch comprises a single sheet of flexible film which has switch electrodes and circuit conductors applied to one surface. The sheet of film is folded to form four sections. After folding, the switch electrodes of the two upper sections are opposed to each other and the electrodes of the remaining two sections are opposed to each other so that when the folded film is pressed at a switch site, the two switches formed by the opposed electrodes are sequentially closed. The switch electrodes are interconnected in accordance with an improved encoding scheme which results in a reduced requirement in the number of circuit conductors, the elimination of some switch electrodes, and other advantages.

Encoded keyboard switch

Key switch assembly comprises a frame having a column in which a plunger is contained. The plunger is biased to an extended position by a spring and is movable to its depressed position. A bell crank is mounted adjacent to the column and has a camming arm which extends alongside the plunger and a switch closing arm. The plunger has a stiffly flexible camming rod and the column has a cam which flexes the camming rod during depression of the plunger so that it engages the camming arm and causes the switch closing arm to close the switch associated with the plunger and frame. The switch is closed for only a brief interval during depression of the plunger and the switch closing lever returns to its normal position after the camming rod moves past the cam.

Key switch assembly having momentary closed interval

An encoded keyboard switch comprises a plurality of key positions. Each key position has first and second membrane switches associated therewith. The first switch is immediately beneath the key top and the second switch is beneath the first switch. The first membrane switch has first switch contacts which are commonly connected to a first common external conductor. The second switch contacts of the first membrane switch have output conductors extending therefrom to external signal conductors. The second switch contacts are selectively connected to each other by encoding conductors. Each second associated membrane switch has third switch contacts which are commonly connected to a second common external conductor, and fourth switch contacts which are commonly connected to an internal conductor that is commonly connected to the first contacts of the first associated membrane switches of the key positions. Upon depression of a top key, the first associated membrane switch closes initially and then the second associated membrane switch is closed, thereby ensuring that the proper output signals will be sent out through the external signal conductors.

Membrane switch comprises a substrate having first, second, and third switch contacts thereon. A flexible insulating film extends parallel to the substrate and has a commoning conductor on its underside. The flexible film has first and second contact projections extending towards the substrate, the first contact projection being against the first switch contact and the second contact projection being spaced from the second switch contact. A pair of supporting projections extend from the film and bear against the surface of the substrate at locations adjacent to the switch contacts. The film is supported by the first contact projection and the air of supporting projections. When the film is pressed towards the substrate, the second contact projection sequentially moves against the second switch contact and thereafter the commoning conductor is moved against the third switch contact.

Membrane switch with sequentially closable contacts

A membrane switch device is described which is composed of two membrane switch arrays which are in parallel closely spaced relationship. A first or original array of membrane switches is provided on a sheet of flexible insulating film which has been folded about a medial fold line so that the switch electrodes on the two opposed surfaces are in alignment. The electrodes have conductors extending therefrom which extend onto a tail. A second array is provided on an extension of the sheet of insulating film and this extension also is folded about its own medial fold line. Additional electrodes and conductors are provided on the extension. A slit is formed between the original section of film and the additional section and the tail is inserted through this slit when the first array is produced by folding the first or original section of film. After the second section or extension of the film is folded to produce the second array of switches, the entire second switch array is folded as a unit towards the first array so that both switch arrays are adjacent to each other and are in parallel planes.

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Reading, MA, United States of America

Kazutoyo Fukukura