Touch plate assembly

• US 4,056,699 A
• Filed: 11/13/1975
• Issued: 11/01/1977
• Est. Priority Date: 11/13/1975
• Status: Expired due to Term

• Current Assignee: D & M Liquidating Trust
• Original Assignee: Essex International, Inc. (LS Corporation)
• Inventors: Jordan, Leslie S.
• Primary Examiner(s): Schaefer, Robert K.
• Assistant Examiner(s): Indyk, Eugene S.
• Application Number:
  US05/631,596
• Time in Patent Office: 719 Days
• Field of Search: 200/52 R, 200/292, 200/310, 200/311, 200/312, 200/313, 200/314, 200/317, 200/DIG. 1, 200/159 B, 200/5 A, 200/5 D, 200/159 A, 317/DIG. 2, 317/101 CC, 317/101 CE, 317/101 CM, 340/365 C
• US Class Current: 200/5.00A
• CPC Class Codes: H01H 13/70 having a plurality of operating members associated with different sets of contacts, e.g. keyboard mounting together a plurality of independent switches H02B
• CPC Class Codes: H01H 2239/004 High frequency adaptation or shielding
• CPC Class Codes: H01H 2239/006 Containing a capacitive switch or usable as such
• CPC Class Codes: H03K 17/962 Capacitive touch switches
• CPC Class Codes: H03K 2217/96023 Details of electro-mechanic connections between different elements, e.g.: sensing plate and integrated circuit containing electronics
• CPC Class Codes: H03K 2217/96076 with spring electrode

Abstract

A touch plate assembly for a digital control device. The touch plate is sectioned off into a plurality of touch switch areas, each of which represents certain information to be entered into the control circuit. The touch plate and a printed circuit board, carrying the detection circuitry are held in place by a housing which may carry other circuitry as well. Electrical connections between the detection circuitry and the touch switches are made by resilient spring contact members rigidly mounted on the circuit board and soldered in place as a component. A combination shield-filter assembly is bonded to the back of the touch plate. The shield-filter assembly includes a metal-polyester laminate having windows therein, through which the spring contact members make electrical contact to contact areas on the touch plate. In addition, certain portions of the metal layer are removed so that light from a light source located on the printed circuit board may be seen by the user of the control.

Claims

1. A touch plate assembly for entering information into a digital control circuit, comprising:

a flat dielectric plate having front and back faces;

a plurality of touch switches on said plate, each said touch switch including a first electrically conductive area on the front face of said dielectric plate representing certain information to be entered into said control circuit, and spaced apart input and output electrically conductive contact areas on the back face of said plate, said input and output contact areas underlying said first electrically conductive area;

a printed circuit board containing circuitry for detecting the activation of said touch switches;

housing means for holding said dielectric plate and said printed circuit board substantially parallel to one another;

resilient electrical contact means for making electrical contact from the circuitry on said printed circuit board to each input and output conductive contact area, said resilient electrical contact means comprising a plurality of resilient bifurcated contacts extending from said printed circuit board toward said dielectric plate, each said bifurcated contact abutting against one of said contact areas to make electrical contact thereto.

2. The touch plate assembly as claimed in claim 1, further comprising:

a laminate bonded to the back face of said dielectric plate, said laminate having a plurality of apertures therein through which said bifurcated contacts extend.

3. The assembly as claimed in claim 2, wherein said laminate is comprised of a metal layer and a polyester layer.

7. The touch plate assembly as claimed in claim 2 wherein said dielectric plate is constructed of relatively rigid breakable material.

4. In a touch plate assembly including an imperforate glass plate having a plurality of touch switches thereon, circuit means located behind said touch plate exposing a potential shock hazard should the touch plate be broken and generating spurious electrical signals, resilient electrical contact means for making electrical contact from said circuit means to said touch switches, and display means located behind said touch plate to be seen by a touch plate operator through windows in a coating on a touch plate, means for minimizing the shock hazard if the touch plate is broken, comprising:

a combination electrical shield-optical filter subassembly comprising a metal-plastic laminate bonded to the backside of the touch plate, the metal layer of said laminate having portions thereof selectively removed so as to provide windows therein aligned with the windows in the coating on the touch plate through which the operator views said displays.

5. A touch plate assembly for entering information into a digital control circuit, comprising:

a flat dielectric plate having front and back faces;

a plurality of touch switches on said dielectric plate;

contact areas on said back face, said contact areas being electrically connected to said touch switches;

a printed circuit board containing circuitry for detecting the activation of said touch switches;

a plurality of bifurcated contacts extending from said printed circuit board toward said dielectric plate, said bifurcated contacts being electrically connected to said circuitry and abutting against said contact areas to electrically connect said circuitry and said touch switches;

housing means for holding said dielectric plate and said printed circuit board substantially parallel to one another, said housing means including first means for engaging a first edge of said flat dielectric plate and a first edge of said printed circuit board, and second means for engaging the opposite edge of said flat dielectric plate and the opposite edge of said printed circuit board.

6. The touch plate assembly as claimed in claim 5, further comprising:

resilient means for normally urging first and second engaging means toward one another.