Keyboard

• US 4,527,030 A
• Filed: 11/22/1983
• Issued: 07/02/1985
• Est. Priority Date: 11/06/1980
• Status: Expired due to Fees

• Current Assignee: PREH Elektrofeinmechanische Werke Jakob PREH Nachf GmbH & Company
• Original Assignee: PREH Elektrofeinmechanische Werke Jakob PREH Nachf GmbH & Company
• Inventors: Oelsch, Jurgen
• Primary Examiner(s): Marcus, Stephen
• Assistant Examiner(s): CUSICK, ERNEST
• Application Number:
  US06/555,034
• Time in Patent Office: 588 Days
• Field of Search: 200/159 B, 200/306, 200/267, 200/268, 200/5 A, 200/292, 200/340, 200/86 R, 200/86.5, 361/398, 361/409, 361/410
• US Class Current: 200/515
• CPC Class Codes: H01H 1/403 Contacts forming part of a printed circuit multilayer keyboard switches H01H13/702; thumbwheel switches H01H19/001; for rotary switches with axial contact pressure H01H19/585
• CPC Class Codes: H01H 13/702 with contacts carried by or formed from layers in a multilayer structure, e.g. membrane switches
• CPC Class Codes: H01H 13/785 characterised by the material of the contacts, e.g. conductive polymers
• CPC Class Codes: H01H 13/807 characterised by the spatial arrangement of the contact sites, e.g. superimposed sites
• CPC Class Codes: H01H 2201/032 Conductive polymer; Rubber
• CPC Class Codes: H01H 2207/014 Plated through holes
• CPC Class Codes: H01H 2209/07 metallic
• CPC Class Codes: H01H 2213/01 with internal pressure of other switch sites
• CPC Class Codes: H01H 2215/004 Collapsible dome or bubble
• CPC Class Codes: H01H 2215/006 Only mechanical function
• CPC Class Codes: H01H 2215/012 Positioning of individual dome
• CPC Class Codes: H01H 2225/002 superimposed
• CPC Class Codes: H01H 2225/018 Consecutive operations
• CPC Class Codes: H01H 2227/008 Substrate
• CPC Class Codes: H01H 2229/002 Screen printing
• CPC Class Codes: H01H 2229/028 Adhesive
• CPC Class Codes: H01H 2229/038 Folding of flexible printed circuit
• CPC Class Codes: H01H 2229/046 Multi-colour or double shot injection moulding
• CPC Class Codes: H01H 2233/022 with limited freedom
• CPC Class Codes: H01H 2239/01 combined with other elements on the same substrate
• CPC Class Codes: H05K 1/0393 : Flexible materials H05K1/038 takes precedence; specific organic compositions are classified in H05K1/0313 and subgroups
• CPC Class Codes: H05K 1/095 : for polymer thick films, i.e. having a permanent organic polymeric binder
• CPC Class Codes: H05K 1/167 : incorporating printed resistors
• CPC Class Codes: H05K 2201/09981 : Metallised walls
• CPC Class Codes: H05K 2203/1453 : Applying the circuit pattern before another process, e.g. before filling of vias with conductive paste, before making printed resistors
• CPC Class Codes: H05K 2203/1572 : Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides
• CPC Class Codes: H05K 3/1216 : by screen printing or stencil printing
• CPC Class Codes: H05K 3/4069 : for via connections in organic insulating substrates
• CPC Class Codes: H05K 3/42 : Plated through-holes or plated via connections

Abstract

A keyboard comprising a flexible-foil printed circuit in which an insulat foil or sheet substrate is provided with printed conductors and contact surfaces, in which the insulating foil sheet is provided with holes, and which includes a plurality of press buttons or keys associated with the contact surfaces, each key comprising an elastically deformable snap-action element which is adapted to be deformed upon actuation by means of an actuating button in order to bring the contact element into contact with the contact surface.

The flexible-foil printed circuit comprises an insulating foil substrate having a thickness not exceeding 0.6 mm which is provided on both sides with printed conductors and on one side with electrical contact surfaces and/or contact elements. The conductors may be formed in separate printing steps for each side of the foil or sheet. Contacts extending through the holes in the substrate may be produced by means of the printing step itself during the printing of the conductors.

Claims

1. A keyboard assembly comprising a number of movable keys, each of said keys being movably retained in juxtaposition to unitary molded snap-action elements sealed to a metallic support member and to a pair of conductors mounted on flexible substrates in close juxtaposition to one another and aligned with said snap-action elements, such that upon depression of one of said keys, the corresponding snap-action element urges one of the corresponding pair of conductors into contact with the other, said assembly comprising a spacer sheet interposed between said flexible substrates and having holes punched therethrough to permit one of said pair of conductors to contact the other, wherein a hole is formed in said metallic support member in the region under each of said keys, the periphery of each of said keys being open to the atmosphere, whereby air is not confined under said unitary snap-action elements sealed to said metallic plate.

2. The keyboard of claim 1 wherein each of the holes provided in said spacer sheet through which the contact between said conductors on said flexible substrates is made further comprises a passage for air communication.

3. The keyboard of claim 1 wherein said movably retained keys are mounted on a key support member, said key support member comprising pins fitting into additional holes in said metal substrate for retention at locations juxtaposed to said snap-action elements.

4. The keyboard of claim 3 wherein each said key comprises concentric cylinders, the inner of said cylinders interfitting with a tubular support member formed in said key support member for sliding relative thereto along the axis of said cylinders, and the outer of said cylinders being adapted to contact a contact surface on said snap-action member upon depression of said key.

5. The keyboard according to claim 4 wherein said cylinders are molded as one piece with said key member.

6. The keyboard of claim 5 wherein said key member additionally comprises retaining tab means for interaction with retaining detent means formed in said key support member.