US3749859A - Keyboard switch assembly with improved hermetically sealed diaphragm contact structure - Google Patents

Keyboard switch assembly with improved hermetically sealed diaphragm contact structure Download PDF

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Publication number
US3749859A
US3749859A US00245577A US3749859DA US3749859A US 3749859 A US3749859 A US 3749859A US 00245577 A US00245577 A US 00245577A US 3749859D A US3749859D A US 3749859DA US 3749859 A US3749859 A US 3749859A
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contact
circuit board
contacts
support
center
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US00245577A
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R Webb
J Webb
T Tyler
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DECISION DATA Inc A CORP OF
Colorado Instruments Inc
NationsBank of Texas NA
Mohawk Systems Corp
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Colorado Instruments Inc
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Assigned to MOHAWK SYSTEMS CORPORATION, A DE CORP reassignment MOHAWK SYSTEMS CORPORATION, A DE CORP ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: MOHAWK DATA SCIENCES CORP., A NY CORP
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Assigned to DECISION DATA INC., A CORP. OF DE reassignment DECISION DATA INC., A CORP. OF DE CHANGE OF NAME (SEE DOCUMENT FOR DETAILS). Assignors: MOMENTUM SYSTEMS CORPORATION, A CORP. OF DE
Assigned to NATIONSBANK OF TEXAS, N.A., AS AGENT reassignment NATIONSBANK OF TEXAS, N.A., AS AGENT ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: FIRST NATIONAL BANK OF BOSTON, AS AGENT
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    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/70Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard
    • H01H13/7006Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch having a plurality of operating members associated with different sets of contacts, e.g. keyboard comprising a separate movable contact element for each switch site, all other elements being integrated in layers
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J5/00Devices or arrangements for controlling character selection
    • B41J5/08Character or syllable selected by means of keys or keyboards of the typewriter type
    • B41J5/12Construction of key buttons
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B41PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
    • B41JTYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
    • B41J5/00Devices or arrangements for controlling character selection
    • B41J5/08Character or syllable selected by means of keys or keyboards of the typewriter type
    • B41J5/16Mounting or connecting key buttons on or to key levers
    • HELECTRICITY
    • H01ELECTRIC ELEMENTS
    • H01HELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H2207/00Connections
    • H01H2207/012Connections via underside of substrate
    • H01H2207/014Plated through holes

Definitions

  • ABSTRACT A contact key for use in a keyboard arrangement is disclosed wherein one contact extends through a circuit 7 board and a second contact comprises a curved plate or dome spring is positioned on one side of the circuit board and is depressable so that the center thereof can come in contact with the first contact to complete a circuit.
  • the first contact comrp'sies a rivet while in another form it comprises a plated-through hole to the back of the circuit board.
  • the second contact can include a dimple at the center thereof which comes in contact with the first contact when the plate is depressed.
  • a plurality ,of these first, I contact members are placed in a circuit board and the second contacts can be supported by a conductive support, such as a shim or plated support having apertures corresponding to the position of the first contacts.
  • the contact support is in the form of the shim, it can comprise a plurality of sections interconnected by frangible tabs which are broken during assembly to separate the sections, the tabs being bent through holes in the circuit board and crimped against the back side to hold the shim in place and to provide connections for the respective sections to appropriate'circuitry.
  • the support can be provided with one or more raised bosses to support the contact plate above the first contact.
  • This-invention relates to an electric signal device, and more particularly to a contact switch for use in a keyboard arrangement, including alpha-numeric keyboard arrangements, to cause the generation of binary signals that are suitable for direct entry into digital data transmission systems,'displays and/or computers.
  • keyboards form the machine/man interface in the data processing system. That is, the operator of the machine depresses keys on the keyboard to form binary or coded binary signals which are fed into the data processing machine.
  • interface equipment is formed by such devices as teletype machines, card keypunch units,,electric typewriters, adding machines, and the like. However, these devices are not entirely satisfactory for various reasons.
  • the most common prior art apparatus for generating data from an array of keys is an electric switch that closes when a key is depressed. This is, each time the key in the keyboard array is depressed an associated switch closes. Closure of the switch causes a coded signal to be generated which uniquely defines the key that was depressed. The data bit pattern thus generated is fed into the data processing system. While apparatus of this nature is generally satisfactory, there are several disadvantages, the complexity of the keys and cost thereof being one significant factor.
  • keyboards generally have several other undesirable features.
  • -many keyboards are thick and not compact and have a relatively high profile, thus making them inconvenient and tiresome to reach.
  • a relatively large keyboard increases the size of the data processing system beyond what is necessary for miniaturized circuitry now available.
  • the action of the keys is frequently less rapid than desirable.
  • simultaneous key depressions may not be detectable.
  • the keys are rugged and not sealed so as to be immune from dust and dirt.
  • an electrical normally open contact switch which includes a first electrical contact, and a second contact formed as a resilient curved plate of electrically conductive material spaced from the first contact in a normally openedpositionand having a peripheral edge along at least a portion of which the second contact is supported and further includes means for connecting the first and second contacts in an electrical circuit, the switch completing the circuit upon deflection of the center of the plate from the normally open position to the closed position against the first contact when presto different sections of the contact support sothat difsure is exerted against the center, the center snapping back to thenormally open position upon removal of the pressure.
  • the switch may be provided in a keyboard array and be mounted on a circuit board which has a plurality of spaced first electrical contacts which extend through the circuit board from a first side of the circuit board to a second side thereof and are electrically connected to selective circuits on the second side.
  • a plurality of second contacts each formed as a curved resilient plate or dome spring are mounted on a contact support on the firstside'of the circuit board which contact support surrounds each .of the first con-. tacts arid has an openingcorresponding'to the position of the first contact.
  • the contact support is formed, in
  • each switch completes a circuit upon deflection of the center of the plate from the normally open position to the closed position against the corresponding first contact when pressure is exerted against the center, the center snapping back to the normally open position upon removal of the pressure.
  • the contact support is formed by electroplating the keyboard and includes a layerof flexible material extending over the side of the circuit board on which the dome springs are supported, completely covering that side of the circuit board to keep moisture and foreign material out of the contacts but permitting deflection of the plate or dome spring contact.
  • a plurality of depressable keys are positioned with one key above each of the second contacts, which keys are held in position with a grid or frame connected to the circuit board.
  • the first contact is formed by a rivet extending through the circuit board from the first side to the second side and connected to selective circuits on the second side. whereas in an altemative embodiment the first contact is formed as a plated through hole in the circuit board which plated through hole is also connected to selective circuits on the second side of the circuit board.
  • the contactsupport in one form of the invention is forrnedas a shim which is made up of separate sections connected together by frangible tabs which tabs may'be' broken during assembly so that they may be forced through holes in the circuit board and clenched to the back side to be soldered or otherwise connected into the circuits on the second side of the circuit'board.
  • This arrangement permits connection of different potentials ferent keys may be used to perform different functions.
  • the contact support is formed, as by electroplating, as a plated support on the circuit board which has a plurality of openings corresponding to the position of the respective first contacts and includes in one embodiment one or more bosses spaced around each opening for supporting the second BRIEF DESCRIPTION OF THE DRAWINGS
  • FIG. 1 is an exploded, fragmentary, perspective view of a keyboard which illustrates a key comprising one form of the invention
  • FIG. 2 is an enlarged vertical section, taken along line 22 of FIG. 1, showing an assembled key in normally open position;
  • FIG. 3 is an exploded, perspective view of a circuit board and contact support showing how the contact support is positioned on the circuit board and attached thereto;
  • FIG. 4 is an exploded, perspective view, similar to FIG. 1, but showing an alternative keyboard for a minicomputer;
  • FIG. 5 is an enlarged vertical section taken along line 55 of FIG. 4, showing an assembled key in normally open position
  • FIG. 6 is a vertical section, similar to FIG. 5, but showing an alternative plate contact
  • FIG. 7 is a fragmentary, perspective view of an alternative contact support having raised bosses
  • FIG. 8 is a fragmentary, vertical section, showing the 7 DESCRIPTION OF THE PREFERRED EMBODIMENTS
  • the keyboard B of FIG. 1 is of the type used for desk calculators or computer keyboards wherein numeric or alpha-numeric function controls are necessary.
  • a series of keys K are mounted as shown on a conventional glass epoxy circuit board 2 which has a printed circuit on the lower side thereof.
  • a first contact 4 extends through the circuit board from the top side to the lower side where it is connected, as by soldering, to a circuit (not shown) as by a lead as shown in FIG. 2.
  • the contact 4 may take the form of a rivet as shown which extends about 0.013 inches above the circuit board.
  • frangible tabs 9 can be broken-by a tool (not shown) which separates shim 7 into separate segments and pushes the ends of tabs 9 through holes punched in circuit board 2 and crimps them against the lower side thereof so that the segments can be soldered or connected to circuitry on the lower side of the circuit board.
  • tabs 9' can be bent through holes in the circuit board to make connections to the other side thereof.
  • Each switch K includes a second contact 10 in the fonn of a plate or curved dome spring which in FIG. 1 is illustrated as being generally triangular shaped with depending legs.
  • This dome spring is more fully described in commonly assigned co-pending U. S. application Ser. No. 175,941 to Wray C. Hansen, filed Aug. 30, 1971.
  • Spring 10 can be deflected downwardly into contact with contact 4 by depressing the key K associated therewith.
  • Thekey includes a cylinder 12 which is conveniently made of polyurethane and rests on top of spring 10 and is surrounded by a coil spring 14. The upper end of coil spring 14 is received in an actuator 16 which has a central recess 18 therefore.
  • the actuator includes a body 20 with an upwardly projecting neck 22, the body having a plurality of semi-cylindrical legs 24 spaced therearound.
  • the actuator is received in a generally cubic housing 26 having a body 28 with downwardly projecting legs 30 thereon which are adapted to be received in openings (not shown) in circuit board 2.
  • the housing includes a lid 32 which has an open cylindrical collar 34 through which neck 22 of actuator 16 is adapted to project.
  • the actuator is slidably mounted within body 28 whereby legs 24 are received in semi-cylindrical recesses 36 within the body.
  • lid 32 is attached to body 28 by means of pins 38 which are received in openings 40 on the body of the housing.
  • Neck 22 of actuator 16 includes an X-shaped element 42 at the upper end thereof adapted to receive a button of key element 44.
  • button 44 When button 44 is depressed, it forces actuator 16 downwardly against coil spring 14 and cylinder 12 and when a sufficient amount of pressure is applied the dome or curved spring 10 rapidly collapses bringing the center thereof into contact with rivet 4 to complete a circuit connection.
  • the spring 10 Upon release of finger pressure-on button 44, the spring 10 quickly snaps back to its arched position over rivet 4.
  • this key K is non-teasable and provides finger touch feedback.
  • the arrangement provides a relatively low profile and is rugged and consumes low power and is readily manufactured at. low cost.
  • the dome spring 10 is approximately 0.005 inches in thickness and is spaced from rivet 4 approximately0.0025 inches. It will be further understood that body 28 may be so dimensioned as to constrain dome 10 from lateral movement. The relative differences in diameter of the dome and body have been exaggerated for clarity of illustration.
  • FIG. 4 An alternative keyboard B is disclosed in FIG. 4 which has particular application in pocket-size or minicalculators of the battery-operated type which can be carried in the pocket or alternatively can be connected to a conventional power source.
  • This keyboard in cludes a'circuit board 46 made of conventional materi-' als which has a plurality of plated-through-holes 48, one of which can be seen in FIG. 5, each of which serves as a first contact for the switch in key K andis connected by a lead 50 to suitable portions of a printed circuit on the bottom side of the circuit board.
  • a contact support 52 is formed on the top side of circuit board 46 as shown in FIGS.
  • a second contact such as a dome spring or plate 54 is mounted as in the previous embodiment the contacts 48 extending through holes or perforations 53 therein.
  • the plated-through holes and the contact support can be formed at the same time to a thickness of say 0.004 inches and a portion of the contact surface of the plated-through hole can be etched away, such as 0.002 inches to provide sufficient clearance for the dome spring to snap through when it makes contact.
  • a spacer or cage 56 is provided having a plurality of openings 58 corresponding to the position of dome spring 54 and is adapted to hold the dome spring in proper orientation with respect to the plated-through holes 48.
  • a thin plastic sheet 60 such as Mylar, is placed over the spacer 56 and the dome spring 54 and conveniently has an adhesive on the contacting side.
  • each dome spring and above sheet 60 is an actuating key, such as key 62 which has a depending finger 63 for depressing dome spring 54, the keys being held in position by a frame or grid 64 which extends thereover as shown in FIG. 4 and is attached to the mini-calculator to hold the same in place.
  • key 62 which has a depending finger 63 for depressing dome spring 54, the keys being held in position by a frame or grid 64 which extends thereover as shown in FIG. 4 and is attached to the mini-calculator to hold the same in place.
  • FIG. 6 An alternative embodiment is shown in FIG. 6 wherein a circuit board 46' has a plated-through hole 48' therein which is connected to selective circuits (not shown) by means of a lead 50'.
  • a dome spring 66 is supported on a contact support 52' and is held in position by a spacer or cage 56', a plastic sheet 60' extending across the spacer and the dome spring 66 to provide a sealed unit.
  • the dome spring 66 is provided with a dimple 68 at the center thereof which provides a downwardly extending projection to providepoint contact the edge of a plated-through hole 48 when the spring is depressed, as by finger 63 of key 62', the latter being held in position by a frame 64'.
  • the platedthrough holesand the contact supports are formed by electroplating, but then the top of the plated-through hole must be etched away so that it is spaced below the contact space a distance on the order of 0.002 inches. In the alternative embodiments shown in FIGS. 7-10 this additional etching procedure is not required.
  • a plated support 52" which is formed on circuit board 46 is provided with a plurality of raised bosses 70, such as three, for supporting a dome spring 72 above a plated hole contact 48".
  • these bosses can be approximately 0.002 inches above the surface of support 52" and thereby support dome spring 72 at a suitable height to allow sufficient deflection of the center thereof to bring it into contact with contact 48".
  • the raised bosses may be formed in the contact support 52" by positioning an embossing die 74 over the contact support and striking the bottom of the circuit board with an embossing punch 76, as shown in FIG. 8. Thus, the etching step can be omitted.
  • FIGS. 9 and -l0 A further alternative embodiment is shown in FIGS. 9 and -l0 wherein a circuit board 46' has acontact support 52" plated thereon which includes a single boss 70 which boss is twice as'high as boss 70 atFIGS. 7 and 8.
  • a dome spring 72' is supported. at one edge by the contact support 52" and at the other edge by raised boss 70' to position dome spring 72 a sufficient distance above plated hole 48" which is connected to suitable circuitry, as by welding,,by means of lead 50".
  • the dome springs 72' are held in position by spacer or cage 56" and are covered by flexible layer 6 60". Each dome spring is deflected by a finger 63" on a key 62" to make contact with plated-through hole 48.
  • the contact support 52" and at the other edge by raised boss 70' to position dome spring 72 a sufficient distance above plated hole 48" which is connected to suitable circuitry, as by welding,,by means of lead 50".
  • the dome springs 72' are held
  • a keyboard for use with calculators is shown in one embodiment wherein the printed circuit board has a shim with openings surrounding contacts in the circuit board which shim is divided into portions that are connected by frangible tabs that are broken during assembly to attach the shim to the circuit board and provide electrical connections thereto.
  • a dome or curve spring is provided above each contact which is supported by the shim and which is depressable to deflect the center thereof into engagement with its associated contact to complete a circuit.
  • the first contact is formed as a rivet in one embodiment.
  • a keyboard for a mini-calculator wherein the contacts extending through the circuit board are formed as plated-through holes which are surrounded by a contact support on the side of the circuit board opposite the circuit and supports curved or dome spring contacts which are posi tioned by means of a spacer, the entire contact assembly being sealed against moisture and foreign matter by means 'of a plastic adhesive layer, such as Mylar, which extends, across the spacer and the, dome springs.
  • the dome springs are deflected selectively by keys position'e'd thereabove within a frame.
  • the dome spring in a further alternative embodiment includes a dimple at the center thereof which is engageable with the platedthrough hole.
  • the contact support is formed with one or more bosses which support the dome spring above the contact to avoid the necessity of etching the plated-through hole so that in its position below the contact hole the contact support a sufficient distance to provide suitable deflection of the dome springs.
  • An electrical normally-open contact switch comprising:
  • a second contact formed as a curved resilient plate of electrically conductive material spaced from said first contact in a normally open position and having a peripheral edge along at leasta portion of which said second contact is supported;
  • circuit board in which said first contact is mounted and having said second contact supported on a first side thereof, said first contact extending through said circuit board and being electrically connected to a circuit on a second side of said circuit board opposite said first side;
  • a keyboard having a plurality of normally ope contact switches, said keyboard comprising:
  • a circuit board having first and second sides; a plurality of spaced first electrical contacts, each tact, said switch completing said circuit upon decontact extending through said circuit board from flection 0f the Center Of Sa plate from Said n0 said first side of said circuit boardto said second mally Open position to a c os d p i i n against side thereof and being electrically connected to sesaid first contact when pressure is exerted against l i i it on id second id said center, said center snapping back to said nora l li of second contacts, h f d as a p position p removal of Said pressure- 10 curved resilient plate of electrically conductive ma- An electrical y- P Contact Switch terial spaced from said first contact in a normally prising! open position and having a peripheral edge along a first elfictrlcal Contact; at least a portion of which said second contact is,
  • a second contact formed as a curved resilient plate of Supported
  • fiifiiTfofiiali ifi a a circuit board in which said first contact is mounted S being conngctagle to a pitemial each of g v and having said second contact supported on a first Switches completing a circuit upon deflection of Srrre h f Said first Contact P through the center of said plate from said normally open f2;121E1212111223 ?ZZSfEFZZEZT'ZLZSTESZZfl P a pp Said first Side; 7 ingdfirsttcontacc: when pressure is) exlfited against means for connecting said first and second contacts :1 5225;;2; gi ggz ggigli :F g 31 2:; l z fy zfg zgi 2: :23: $232332 an insulative element covering said first side of said circuit board for supporting said second concfrculibqard to hold siild second contacts m p05]- tact,
  • a keyboard as claimed in claim 4, wherein said a first electrical contact; contact support i a second contact formed as a curved resilient plate of clash-cally mater'al plated first electrically conductive material spaced from said Srcle of Sard c'rcurt board andrurrormdmg each or first contact in a normally open position andhaving Sard first contacts for supporrmg sard second a peripheral edge along at least a portion of which racrs' Said second Contact is supported; 6.
  • a keyboard as claimed in claim 4, wherein said a circuit board in which said first contact is mounted Contact suplforr rrrcruderi I and having said second contact supported on a first a conducrweflhlm havmg Perfomtlons correspondlilg side thereof, said first contact extending through Posltlons of Sald first contacts that 531d said circuit board and being electrically connected 5hrm surrcfmds each of said first contacts for P to a circuit on a second side of said circuit board Porting Sald second contactsopposite Said fi Side; 7.
  • said means for connecting said first and second contacts Shim Comprises:
  • said first contact when pressure is exerted against each of Said plates has a projection at said center said center, said center snapping back to said northereof extending toward said first contact and mally open position upon removal of said pressure; adapted to engage said first contact upon deflecand tion of each of said plates.
  • each of said first contacts' is a rivet.
  • each of said first contacts is a plated hole through spacer means positioned about the periphery of said said circuit board from said first side of said second second contacts to hold said second contacts so side. that the centers thereof are in substantial alignment 11.
  • a keyboard, as claimed in claim 4, wherein said with said first contacts. insulative element further includes:

Abstract

A contact key for use in a keyboard arrangement is disclosed wherein one contact extends through a circuit board and a second contact comprises a curved plate or dome spring is positioned on one side of the circuit board and is depressable so that the center thereof can come in contact with the first contact to complete a circuit. In one form of the invention the first contact comrpsies a rivet while in another form it comprises a plated-through hole to the back of the circuit board. The second contact can include a dimple at the center thereof which comes in contact with the first contact when the plate is depressed. A plurality of these first contact members are placed in a circuit board and the second contacts can be supported by a conductive support, such as a shim or plated support having apertures corresponding to the position of the first contacts. If the contact support is in the form of the shim, it can comprise a plurality of sections interconnected by frangible tabs which are broken during assembly to separate the sections, the tabs being bent through holes in the circuit board and crimped against the back side to hold the shim in place and to provide connections for the respective sections to appropriate circuitry. In an embodiment having a plated contact support, the support can be provided with one or more raised bosses to support the contact plate above the first contact.

Description

United States Patent 1191 Webb et al.
11] 3,749,859 [451 July 31,1973
[75] Inventors: Richard C. Webb; James R. Webb,
both of Boulder; Tommy N. Tyler, Broomfield, all of C010.
[73] Assignee: Colorado Instruments, Inc.,
' Broomfield, Colo.
221. Filed: Apr. 19, 1972 [21] Appl. No.: 245,577 1 [52] 0.8. 200/5 R, 200/5 A, 200/159 B, 200/166 BI-I, ZOO/168 G [51] Int. Cl. H01h 5/04, IIOlh 13/52 [58] Field of Search '....'.."200/159 R, 159 B, 200/166 BH, 167 R, 168 G, 5 R, 5 A, 16 A [56] References Cited V UNITED STATES PATENTS 3,684,842 8/1972 Boulanger zoo/159 B x 3,643,041 2/1972 Jackson ZOO/159 B X 3,591,749 t 7/1971 Comstock.. ZOO/167 R 2,262,777 11/1941 Roper 200/159 B 3,641,286 2/1972 Berezowski.... 200/159 R 3,657,492 4/1972 Arndt et al; 200/159 B X 1/1949 -Great Britain 200/159 B Primary Examiner-.1. R. 'Scott Attorney-Sheridan, Ross & Fields [5 7] ABSTRACT A contact key for use in a keyboard arrangement is disclosed wherein one contact extends through a circuit 7 board and a second contact comprises a curved plate or dome spring is positioned on one side of the circuit board and is depressable so that the center thereof can come in contact with the first contact to complete a circuit. In one form of the invention the first contact comrp'sies a rivet while in another form it comprises a plated-through hole to the back of the circuit board. The second contact can include a dimple at the center thereof which comes in contact with the first contact when the plate is depressed. A plurality ,of these first, I contact members are placed in a circuit board and the second contacts can be supported by a conductive support, such as a shim or plated support having apertures corresponding to the position of the first contacts. If the contact support is in the form of the shim, it can comprise a plurality of sections interconnected by frangible tabs which are broken during assembly to separate the sections, the tabs being bent through holes in the circuit board and crimped against the back side to hold the shim in place and to provide connections for the respective sections to appropriate'circuitry. In an embodiment having a plated contact support, the support can be provided with one or more raised bosses to support the contact plate above the first contact.
ll Claims, l0'Drawing Figures KEYBOARD SWITCH ASSEMBLY WITH IMPROVED HERMETICALLY SEALED DIAPHRAGM CONTACT STRUCTURE BACKGROUND OF THE INVENTION 1. Field of the Invention v This-invention relates to an electric signal device, and more particularly to a contact switch for use in a keyboard arrangement, including alpha-numeric keyboard arrangements, to cause the generation of binary signals that are suitable for direct entry into digital data transmission systems,'displays and/or computers.
2. Description of the Prior Art With the advent of the widespread use of electronic data processing systems, commonly known as computers, there is a need for a simpler, smaller, low cost and generally more satisfactory keyboard data entry system since keyboards form the machine/man interface in the data processing system. That is, the operator of the machine depresses keys on the keyboard to form binary or coded binary signals which are fed into the data processing machine. Currently, such interface equipment is formed by such devices as teletype machines, card keypunch units,,electric typewriters, adding machines, and the like. However, these devices are not entirely satisfactory for various reasons.
The most common prior art apparatus for generating data from an array of keys is an electric switch that closes when a key is depressed. This is, each time the key in the keyboard array is depressed an associated switch closes. Closure of the switch causes a coded signal to be generated which uniquely defines the key that was depressed. The data bit pattern thus generated is fed into the data processing system. While apparatus of this nature is generally satisfactory, there are several disadvantages, the complexity of the keys and cost thereof being one significant factor.
It will be appreciated by those who have used them that prior art keyboards generally have several other undesirable features. For example,-many keyboards are thick and not compact and have a relatively high profile, thus making them inconvenient and tiresome to reach. Furthermore, a relatively large keyboard increases the size of the data processing system beyond what is necessary for miniaturized circuitry now available. In addition, the action of the keys is frequently less rapid than desirable. Furthermore, simultaneous key depressions may not be detectable. Often the keys are rugged and not sealed so as to be immune from dust and dirt. Some keyboard systems are adversely subject to changes in temperature. Furthermore, many systems use more than a minimal amount of power, making them unuseful in battery operated environments.
sulwvmnv 0 THEINYENTION,
In accordance with the present invention, an electrical normally open contact switch is provided which includes a first electrical contact, and a second contact formed as a resilient curved plate of electrically conductive material spaced from the first contact in a normally openedpositionand having a peripheral edge along at least a portion of which the second contact is supported and further includes means for connecting the first and second contacts in an electrical circuit, the switch completing the circuit upon deflection of the center of the plate from the normally open position to the closed position against the first contact when presto different sections of the contact support sothat difsure is exerted against the center, the center snapping back to thenormally open position upon removal of the pressure.
More particularly, the switch may be provided in a keyboard array and be mounted on a circuit board which has a plurality of spaced first electrical contacts which extend through the circuit board from a first side of the circuit board to a second side thereof and are electrically connected to selective circuits on the second side. A plurality of second contacts each formed as a curved resilient plate or dome spring are mounted on a contact support on the firstside'of the circuit board which contact support surrounds each .of the first con-. tacts arid has an openingcorresponding'to the position of the first contact. The contact support is formed, in
one embodiment, in separate sections interconnected by frangible tabs which are broken during assembly and crimped through appropriate holes in the circuit board and crimped against the other side. The selective sections can be connected, as by soldering to selective circuitry on the other side and each section is connectable to a separate potential to provide different circuit capabilities with different keys. It is understood that each switch completes a circuit upon deflection of the center of the plate from the normally open position to the closed position against the corresponding first contact when pressure is exerted against the center, the center snapping back to the normally open position upon removal of the pressure. In another embodiment, the contact supportis formed by electroplating the keyboard and includes a layerof flexible material extending over the side of the circuit board on which the dome springs are supported, completely covering that side of the circuit board to keep moisture and foreign material out of the contacts but permitting deflection of the plate or dome spring contact. In addition, a plurality of depressable keys are positioned with one key above each of the second contacts, which keys are held in position with a grid or frame connected to the circuit board.
In one form of the invention the first contact is formed by a rivet extending through the circuit board from the first side to the second side and connected to selective circuits on the second side. whereas in an altemative embodiment the first contact is formed as a plated through hole in the circuit board which plated through hole is also connected to selective circuits on the second side of the circuit board.
The contactsupport in one form of the invention is forrnedas a shim which is made up of separate sections connected together by frangible tabs which tabs may'be' broken during assembly so that they may be forced through holes in the circuit board and clenched to the back side to be soldered or otherwise connected into the circuits on the second side of the circuit'board. This arrangement permits connection of different potentials ferent keys may be used to perform different functions.
In an alternative embodiment the contact support is formed, as by electroplating, as a plated support on the circuit board which has a plurality of openings corresponding to the position of the respective first contacts and includes in one embodiment one or more bosses spaced around each opening for supporting the second BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an exploded, fragmentary, perspective view of a keyboard which illustrates a key comprising one form of the invention;
FIG. 2 is an enlarged vertical section, taken along line 22 of FIG. 1, showing an assembled key in normally open position;
FIG. 3 is an exploded, perspective view of a circuit board and contact support showing how the contact support is positioned on the circuit board and attached thereto;
FIG. 4 is an exploded, perspective view, similar to FIG. 1, but showing an alternative keyboard for a minicomputer;
FIG. 5 is an enlarged vertical section taken along line 55 of FIG. 4, showing an assembled key in normally open position,
FIG. 6 is a vertical section, similar to FIG. 5, but showing an alternative plate contact;
FIG. 7 is a fragmentary, perspective view of an alternative contact support having raised bosses;
FIG. 8 is a fragmentary, vertical section, showing the 7 DESCRIPTION OF THE PREFERRED EMBODIMENTS In accordance with this invention, the keyboard B of FIG. 1 is of the type used for desk calculators or computer keyboards wherein numeric or alpha-numeric function controls are necessary. A series of keys K are mounted as shown on a conventional glass epoxy circuit board 2 which has a printed circuit on the lower side thereof. At the center of each key position a first contact 4 extends through the circuit board from the top side to the lower side where it is connected, as by soldering, to a circuit (not shown) as by a lead as shown in FIG. 2. Conveniently, the contact 4 may take the form of a rivet as shown which extends about 0.013 inches above the circuit board.
g A shim 7, which I has a thickness of about 0.010 inches, extends over substantially the entire upper surface of the circuit board and is provided with a series of openings or perforations 8 which are adapted to be received over the respective contacts 4. Conveniently, during assembly frangible tabs 9 can be broken-by a tool (not shown) which separates shim 7 into separate segments and pushes the ends of tabs 9 through holes punched in circuit board 2 and crimps them against the lower side thereof so that the segments can be soldered or connected to circuitry on the lower side of the circuit board. Similarly, tabs 9' can be bent through holes in the circuit board to make connections to the other side thereof.
Each switch K includes a second contact 10 in the fonn of a plate or curved dome spring which in FIG. 1 is illustrated as being generally triangular shaped with depending legs. This dome spring is more fully described in commonly assigned co-pending U. S. application Ser. No. 175,941 to Wray C. Hansen, filed Aug. 30, 1971. Spring 10 can be deflected downwardly into contact with contact 4 by depressing the key K associated therewith. Thekey includes a cylinder 12 which is conveniently made of polyurethane and rests on top of spring 10 and is surrounded by a coil spring 14. The upper end of coil spring 14 is received in an actuator 16 which has a central recess 18 therefore. The actuator includes a body 20 with an upwardly projecting neck 22, the body having a plurality of semi-cylindrical legs 24 spaced therearound. The actuator is received in a generally cubic housing 26 having a body 28 with downwardly projecting legs 30 thereon which are adapted to be received in openings (not shown) in circuit board 2. The housing includes a lid 32 which has an open cylindrical collar 34 through which neck 22 of actuator 16 is adapted to project. The actuator is slidably mounted within body 28 whereby legs 24 are received in semi-cylindrical recesses 36 within the body. Conveniently, lid 32 is attached to body 28 by means of pins 38 which are received in openings 40 on the body of the housing.
Neck 22 of actuator 16 includes an X-shaped element 42 at the upper end thereof adapted to receive a button of key element 44. In operation, when button 44 is depressed, it forces actuator 16 downwardly against coil spring 14 and cylinder 12 and when a sufficient amount of pressure is applied the dome or curved spring 10 rapidly collapses bringing the center thereof into contact with rivet 4 to complete a circuit connection. Upon release of finger pressure-on button 44, the spring 10 quickly snaps back to its arched position over rivet 4. Advantageously, this key K is non-teasable and provides finger touch feedback. Also, the arrangement provides a relatively low profile and is rugged and consumes low power and is readily manufactured at. low cost. Advantageously, the dome spring 10 is approximately 0.005 inches in thickness and is spaced from rivet 4 approximately0.0025 inches. It will be further understood that body 28 may be so dimensioned as to constrain dome 10 from lateral movement. The relative differences in diameter of the dome and body have been exaggerated for clarity of illustration.
An alternative keyboard B is disclosed in FIG. 4 which has particular application in pocket-size or minicalculators of the battery-operated type which can be carried in the pocket or alternatively can be connected to a conventional power source. This keyboard in cludes a'circuit board 46 made of conventional materi-' als which has a plurality of plated-through-holes 48, one of which can be seen in FIG. 5, each of which serves as a first contact for the switch in key K andis connected by a lead 50 to suitable portions of a printed circuit on the bottom side of the circuit board. A contact support 52 is formed on the top side of circuit board 46 as shown in FIGS. 4 and 5, as by electroplating, upon which a second contact such as a dome spring or plate 54 is mounted as in the previous embodiment the contacts 48 extending through holes or perforations 53 therein. Advantageously, the plated-through holes and the contact support can be formed at the same time to a thickness of say 0.004 inches and a portion of the contact surface of the plated-through hole can be etched away, such as 0.002 inches to provide sufficient clearance for the dome spring to snap through when it makes contact. In this embodiment, a spacer or cage 56 is provided having a plurality of openings 58 corresponding to the position of dome spring 54 and is adapted to hold the dome spring in proper orientation with respect to the plated-through holes 48. To protect the contacts from moisture, dirt and other foreign matter, a thin plastic sheet 60, such as Mylar, is placed over the spacer 56 and the dome spring 54 and conveniently has an adhesive on the contacting side.
Above each dome spring and above sheet 60 is an actuating key, such as key 62 which has a depending finger 63 for depressing dome spring 54, the keys being held in position by a frame or grid 64 which extends thereover as shown in FIG. 4 and is attached to the mini-calculator to hold the same in place.
An alternative embodiment is shown in FIG. 6 wherein a circuit board 46' has a plated-through hole 48' therein which is connected to selective circuits (not shown) by means of a lead 50'. A dome spring 66 is supported on a contact support 52' and is held in position by a spacer or cage 56', a plastic sheet 60' extending across the spacer and the dome spring 66 to provide a sealed unit. In this embodiment, the dome spring 66 is provided with a dimple 68 at the center thereof which provides a downwardly extending projection to providepoint contact the edge of a plated-through hole 48 when the spring is depressed, as by finger 63 of key 62', the latter being held in position by a frame 64'.
In the embodiments of FIGS. 5 and 6 the platedthrough holesand the contact supports are formed by electroplating, but then the top of the plated-through hole must be etched away so that it is spaced below the contact space a distance on the order of 0.002 inches. In the alternative embodiments shown in FIGS. 7-10 this additional etching procedure is not required. To avoid this, a plated support 52" which is formed on circuit board 46 is provided with a plurality of raised bosses 70, such as three, for supporting a dome spring 72 above a plated hole contact 48". Conveniently, these bosses can be approximately 0.002 inches above the surface of support 52" and thereby support dome spring 72 at a suitable height to allow sufficient deflection of the center thereof to bring it into contact with contact 48". The raised bosses may be formed in the contact support 52" by positioning an embossing die 74 over the contact support and striking the bottom of the circuit board with an embossing punch 76, as shown in FIG. 8. Thus, the etching step can be omitted.
A further alternative embodiment is shown in FIGS. 9 and -l0 wherein a circuit board 46' has acontact support 52" plated thereon which includes a single boss 70 which boss is twice as'high as boss 70 atFIGS. 7 and 8. Thus a dome spring 72' is supported. at one edge by the contact support 52" and at the other edge by raised boss 70' to position dome spring 72 a sufficient distance above plated hole 48" which is connected to suitable circuitry, as by welding,,by means of lead 50". The dome springs 72' are held in position by spacer or cage 56" and are covered by flexible layer 6 60". Each dome spring is deflected by a finger 63" on a key 62" to make contact with plated-through hole 48. Conveniently, as in previous embodiments, the
keys are positioned by a frame 64".With this arrangement, it is necessary only to make one boss, and this is advantageous because it is some times difficult to find three equally spaced positions around a contact support which can be engaged by the embossing punch without disturbing the printed circuitry on the bottom side of the circuit board. I I
The dimensions described are exemplary only and may be varied for particular applications as required. In this regard, a spacingbetween the center contact and the dome spring of 0.010 and 0.020 inches has been found'to be satisfactory.
From the foregoing, the advantages of this invention are readily apparent. A keyboard for use with calculators is shown in one embodiment wherein the printed circuit board has a shim with openings surrounding contacts in the circuit board which shim is divided into portions that are connected by frangible tabs that are broken during assembly to attach the shim to the circuit board and provide electrical connections thereto. In addition, a dome or curve spring is provided above each contact which is supported by the shim and which is depressable to deflect the center thereof into engagement with its associated contact to complete a circuit. The first contact is formed as a rivet in one embodiment.
In an alternative embodiment a keyboard is provided for a mini-calculator wherein the contacts extending through the circuit board are formed as plated-through holes which are surrounded by a contact support on the side of the circuit board opposite the circuit and supports curved or dome spring contacts which are posi tioned by means of a spacer, the entire contact assembly being sealed against moisture and foreign matter by means 'of a plastic adhesive layer, such as Mylar, which extends, across the spacer and the, dome springs. The dome springs are deflected selectively by keys position'e'd thereabove within a frame. The dome spring in a further alternative embodiment includes a dimple at the center thereof which is engageable with the platedthrough hole. In a still further alternative embodiment the contact support is formed with one or more bosses which support the dome spring above the contact to avoid the necessity of etching the plated-through hole so that in its position below the contact hole the contact support a sufficient distance to provide suitable deflection of the dome springs.
The invention has been described in detail with particular reference to preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the field and scope of this invention.
What is claimed is: 1. An electrical normally-open contact switch comprising:
a first electrical contact;
1 a second contact formed as a curved resilient plate of electrically conductive material spaced from said first contact in a normally open position and having a peripheral edge along at leasta portion of which said second contact is supported;
a circuit board in which said first contact is mounted and having said second contact supported on a first side thereof, said first contact extending through said circuit board and being electrically connected to a circuit on a second side of said circuit board opposite said first side; and
means for connecting said first and second contacts in an electrical circuit which includes an electrically conductive support plated on said first side of said circuit board for supporting said second con- 8 4. A keyboard having a plurality of normally ope contact switches, said keyboard comprising:
a circuit board having first and second sides; a plurality of spaced first electrical contacts, each tact, said switch completing said circuit upon decontact extending through said circuit board from flection 0f the Center Of Sa plate from Said n0 said first side of said circuit boardto said second mally Open position to a c os d p i i n against side thereof and being electrically connected to sesaid first contact when pressure is exerted against l i i it on id second id said center, said center snapping back to said nora l li of second contacts, h f d as a p position p removal of Said pressure- 10 curved resilient plate of electrically conductive ma- An electrical y- P Contact Switch terial spaced from said first contact in a normally prising! open position and having a peripheral edge along a first elfictrlcal Contact; at least a portion of which said second contact is,
a second contact formed as a curved resilient plate of Supported;
electrically conductive material spaced from said a Contact Support on Said fi side f Said circuit fi Contact in a normauy'open posirro"l board spaced from each of said first contacts and 135k;iiil iiiiltiii nfllffi ifi lfiiiiei Of ZiZZL ZEtZZl? fiifiiTfofiiali ifi a a circuit board in which said first contact is mounted S being conngctagle to a pitemial each of g v and having said second contact supported on a first Switches completing a circuit upon deflection of Srrre h f Said first Contact P through the center of said plate from said normally open f2;121E1212111223 ?ZZSfEFZZEZT'ZLZSTESZZfl P a pp Said first Side; 7 ingdfirsttcontacc: when pressure is) exlfited against means for connecting said first and second contacts :1 5225;;2; gi ggz ggigli :F g 31 2:; l z fy zfg zgi 2: :23: $232332 an insulative element covering said first side of said circuit board for supporting said second concfrculibqard to hold siild second contacts m p05]- tact, said switch completing said circuit upon deuon.wlth respect to said fi contacts i to keep flection of the center of said plate from said norf r s f i j pi g mally open position to a closed position against i mg a .ayer .2 m :2 ena 9. said first contact when pressure is exerted against fg i i c said center, said center snapping back to said nora p um lty o i i f k mally open position upon removal of said pressure; 35 for posmonmg keys with one o y and ad acent each of said second contacts with said at least one boss projecting from said plated support, of fleiflble mat,ena] thereberween' each of said boss supporting a portion of said peripheral sald y bemg selecuveiy depresslble to deflgqt a edge above Said plated support. respective plate from said normally open position 3. An electrical normally-open contact switch com- 40 to a closed prising: 5. A keyboard, as claimed in claim 4, wherein said a first electrical contact; contact support i a second contact formed as a curved resilient plate of clash-cally mater'al plated first electrically conductive material spaced from said Srcle of Sard c'rcurt board andrurrormdmg each or first contact in a normally open position andhaving Sard first contacts for supporrmg sard second a peripheral edge along at least a portion of which racrs' Said second Contact is supported; 6. A keyboard, as claimed in claim 4, wherein said a circuit board in which said first contact is mounted Contact suplforr rrrcruderi I and having said second contact supported on a first a conducrweflhlm havmg Perfomtlons correspondlilg side thereof, said first contact extending through Posltlons of Sald first contacts that 531d said circuit board and being electrically connected 5hrm surrcfmds each of said first contacts for P to a circuit on a second side of said circuit board Porting Sald second contactsopposite Said fi Side; 7. A keyboard, as claimed in claim 6, wherein said means for connecting said first and second contacts Shim Comprises:
in an electrical circuit which includes an electriatleast twosectionsinterconnectedtby;frangible tabs cally conductive support'plated on said first sideof which can be fractured during assembly and bent said circuit board for supporting said second conrough Openings in said circu t board for ttact, said switch completing said circuit upon deing said respective sections to selective circuits on flection of the center of said plate from said nor- Said Second S d O Sa Circuit bOard. mally open position to a closed position against A keyboard, as Claimed in claim 4, wherein: said first contact when pressure is exerted against each of Said plates has a projection at said center said center, said center snapping back to said northereof extending toward said first contact and mally open position upon removal of said pressure; adapted to engage said first contact upon deflecand tion of each of said plates.
9. A keyboard, as claimed in claim 4, wherein: each of said first contacts'is a rivet. 10. A keyboard, as claimed in claim 4, wherein:
three bosses projecting from said plated support, said bosses supporting said peripheral edge above said plated support.
9 a 10 each of said first contacts is a plated hole through spacer means positioned about the periphery of said said circuit board from said first side of said second second contacts to hold said second contacts so side. that the centers thereof are in substantial alignment 11. A keyboard, as claimed in claim 4, wherein said with said first contacts. insulative element further includes:
I I UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATEVNT N0; 3,749,859 I DATED 1 July 31, 1973 INVENTOHS) I Richard C. Webb, Iames R Webb and TommyN. Tyler It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:
Column 1', line 23 delete teletype and insert before machines the following: telecommunications devices, such as Teletype Signed and scaled this v Twentieth Day or Noveniberl979 [SEAL] RUT MASON LUTRELLE F. PARKER UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION PATENT NO. 3,749,859 I DATE-D I111 31, 1973 INVENTOR(S) Richard C. Webb; James R. Webb and Tommy N. Tyler It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below: v
Column 1, line 23 delete teletype and insert before machines the following: telecommunications devices, such as Teletype Signed and Salad this Twentieth D a y of November I 979 [SEAL] Anm:
RUT MASON LUTRELLE F. PARKER Arresting Oflicer Acting Commissioner of Patents and Trademarks

Claims (11)

1. An electrical normally-open contact switch comprising: a first electrical contact; a second contact formed as a curved resilient plate of electrically conductive material spaced from said first contact in a normally open position and having a peripheral edge along at least a portion of which said second contact is supported; a circuit board in which said first contact is mounted and having said second contact supported on a first side thereof, said first contact extending through said circuit board and being electrically connected to a circuit on a second side of said circuit board opposite said first side; and means for connecting said first and second contacts in an electrical circuit which includes an electrically conductive support plated on said first side of said circuit board for supporting said second contact, said switch completing said circuit upon deflection of the center of said plate from said normally open position to a closed position against said first contact when pressure is exerted against said center, said center snapping back to said normally open position upon removal of said pressure.
2. An electrical normally-open contact switch comprising: a first electrical contact; a second contact formed as a curved resilient plate of electrically conductive material spaced from said first contact in a normally-open position and having a peripheral edge along at least a portion of which said second contact is supported; a circuit board in which said first contact is mounted and having said second contact supported on a first side thereof, said first contact extending through said circuit board and being electrically connected to a circuit on a second side of said circuit board opposite said first side; means for connecting said first and second contacts in an eLectrical circuit which includes an electrically conductive support plated on said first side of said circuit board for supporting said second contact, said switch completing said circuit upon deflection of the center of said plate from said normally open position to a closed position against said first contact when pressure is exerted against said center, said center snapping back to said normally open position upon removal of said pressure; and at least one boss projecting from said plated support, said boss supporting a portion of said peripheral edge above said plated support.
3. An electrical normally-open contact switch comprising: a first electrical contact; a second contact formed as a curved resilient plate of electrically conductive material spaced from said first contact in a normally open position and having a peripheral edge along at least a portion of which said second contact is supported; a circuit board in which said first contact is mounted and having said second contact supported on a first side thereof, said first contact extending through said circuit board and being electrically connected to a circuit on a second side of said circuit board opposite said first side; means for connecting said first and second contacts in an electrical circuit which includes an electrically conductive support plated on said first side of said circuit board for supporting said second contact, said switch completing said circuit upon deflection of the center of said plate from said normally open position to a closed position against said first contact when pressure is exerted against said center, said center snapping back to said normally open position upon removal of said pressure; and three bosses projecting from said plated support, said bosses supporting said peripheral edge above said plated support.
4. A keyboard having a plurality of normally open contact switches, said keyboard comprising: a circuit board having first and second sides; a plurality of spaced first electrical contacts, each contact extending through said circuit board from said first side of said circuit board to said second side thereof and being electrically connected to selective circuits on said second side; a plurality of second contacts, each formed as a curved resilient plate of electrically conductive material spaced from said first contact in a normally open position and having a peripheral edge along at least a portion of which said second contact is supported; a contact support on said first side of said circuit board spaced from each of said first contacts and supporting said second contacts along at least a portion of their peripheral edges, said contact support being connectable to a potential, each of said switches completing a circuit upon deflection of the center of said plate from said normally open position to a closed position against a corresponding first contact when pressure is exerted against said center, said center snapping back to said normally open position upon removal of said pressure; an insulative element covering said first side of said circuit board to hold said second contacts in position with respect to said first contacts and to keep foreign material out of said contacts, said element including a layer of thin flexible material completely covering said second contacts; a plurality of depressible keys; and means for positioning said keys with one of said keys adjacent each of said second contacts with said layer of flexible material therebetween, each of said keys being selectively depressible to deflect a respective plate from said normally open position to a closed position.
5. A keyboard, as claimed in claim 4, wherein said contact support includes: electrically conductive material plated to said first side of said circuit board and surrounding each of said first contacts for supporting said second contacts.
6. A keyboard, as claimed in claim 4, wherein said contact support includes: a conductive shim having perforations corresponding to the positions of said first contacts so that said shim surrounds each of said first contacts for supporting said second contacts.
7. A keyboard, as claimed in claim 6, wherein said shim comprises: at least two sections interconnected by frangible tabs which can be fractured during assembly and bent through openings in said circuit board for connecting said respective sections to selective circuits on said second side of said circuit board.
8. A keyboard, as claimed in claim 4, wherein: each of said plates has a projection at said center thereof extending toward said first contact and adapted to engage said first contact upon deflection of each of said plates.
9. A keyboard, as claimed in claim 4, wherein: each of said first contacts is a rivet.
10. A keyboard, as claimed in claim 4, wherein: each of said first contacts is a plated hole through said circuit board from said first side of said second side.
11. A keyboard, as claimed in claim 4, wherein said insulative element further includes: spacer means positioned about the periphery of said second contacts to hold said second contacts so that the centers thereof are in substantial alignment with said first contacts.
US00245577A 1972-04-19 1972-04-19 Keyboard switch assembly with improved hermetically sealed diaphragm contact structure Expired - Lifetime US3749859A (en)

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US6555774B1 (en) * 2000-07-28 2003-04-29 Microsoft Corporation Lever keyswitch
US20110220478A1 (en) * 2008-07-16 2011-09-15 Pietro Rocereto Push button switch with anti-jamming protection device
US20120067711A1 (en) * 2010-09-16 2012-03-22 Hon Hai Precision Industry Co., Ltd. Electronic device having waterproof button
CN103681061A (en) * 2012-09-11 2014-03-26 罗技欧洲公司 Key frame module for flexible keyboard
US20140262715A1 (en) * 2013-03-15 2014-09-18 Logitech Europe S.A. Keyframe modules for a flexible keyboard

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US3973091A (en) * 1975-02-03 1976-08-03 Texas Instruments Incorporated Pushbutton keyboard assembly having pole and inner contacts simultaneously engaged by a bridging contact
US3996428A (en) * 1975-03-17 1976-12-07 Litronix, Inc. Pushbutton keyboard assembly with over center diaphragm contact
US3978297A (en) * 1975-03-31 1976-08-31 Chomerics, Inc. Keyboard switch assembly with improved pushbutton and associated double snap acting actuator/contactor structure
US3988551A (en) * 1975-04-03 1976-10-26 Magic Dot, Inc. Membrane keyboard apparatus having common apertured electrode, aperture inserted electrodes and conductive bubble contactors
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US4021630A (en) * 1975-04-25 1977-05-03 Neomed Incorporated Hermetically sealed resilient contact switch having surgical applications
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US4375017A (en) * 1976-12-06 1983-02-22 Rca Corporation Calculator type keyboard including printed circuit board contacts and method of forming
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US4319099A (en) * 1979-05-03 1982-03-09 Atari, Inc. Dome switch having contacts offering extended wear
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US4439646A (en) * 1981-04-22 1984-03-27 Societe De Telecommunications Electronique Aeronautique Et Maritime T.E.A.M. Keyboard switch assembly
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EP0074315A2 (en) * 1981-09-01 1983-03-16 Telemecanique Hermetically sealed, modular, tactile keyboard
EP0074315A3 (en) * 1981-09-01 1983-10-05 La Telemecanique Electrique Hermetically sealed, modular, tactile keyboard
US4471189A (en) * 1981-09-01 1984-09-11 La Telemecanique Electrique Sealed, modular keyboard providing a tactile feel
US4476355A (en) * 1981-11-09 1984-10-09 Grayhill, Inc. Keyboard assembly
EP0092518A2 (en) * 1982-04-15 1983-10-26 Alcatel STR AG Key element
EP0092518A3 (en) * 1982-04-15 1984-11-28 Standard Telephon Und Radio Ag Key element
EP0100875A2 (en) * 1982-08-06 1984-02-22 PREH, Elektrofeinmechanische Werke Jakob Preh Nachf. GmbH & Co. Contact arrangement
EP0100875A3 (en) * 1982-08-06 1986-11-05 Preh, Elektrofeinmechanische Werke Jakob Preh Nachf. Gmbh & Co. Contact arrangement
US4681987A (en) * 1983-01-11 1987-07-21 Canon Kabushiki Kaisha Electronic equipment having a key input function
US4501937A (en) * 1983-03-14 1985-02-26 Eaton Corporation Integral multiswitch display panel
US4468542A (en) * 1983-05-16 1984-08-28 Kb Denver, Inc. Keyboard assembly
EP0157037A2 (en) * 1984-03-29 1985-10-09 Bowmar Instrument Corporation Long-stroke push-button switch
EP0157037A3 (en) * 1984-03-29 1986-11-05 Bowmar Instrument Corporation Long-stroke push-button switch
FR2615320A1 (en) * 1987-05-12 1988-11-18 Schoeller & Co Elektrotech PUSH BUTTON SWITCH
US5160270A (en) * 1989-06-13 1992-11-03 General Datacomm, Inc. Integrated circuit packages using tapered spring contact leads for direct mounting to circuit boards
US5144104A (en) * 1990-03-30 1992-09-01 Sextant Avionique Miniature switch device with tactile effect
US6555774B1 (en) * 2000-07-28 2003-04-29 Microsoft Corporation Lever keyswitch
EP1207543A3 (en) * 2000-11-15 2004-08-18 Hosiden Corporation Pushbutton switch
EP1207543A2 (en) * 2000-11-15 2002-05-22 Hosiden Corporation Pushbutton switch
EP1239500A2 (en) * 2001-03-06 2002-09-11 Citizen Electronics Co., Ltd. Tactile switch
US20110220478A1 (en) * 2008-07-16 2011-09-15 Pietro Rocereto Push button switch with anti-jamming protection device
US8698026B2 (en) * 2008-07-16 2014-04-15 Bticino S.P.A. Push button switch with anti-jamming protection device
CN102084449B (en) * 2008-07-16 2014-07-02 布蒂克诺公司 Push button switch with anti-jamming protection device
TWI463511B (en) * 2008-07-16 2014-12-01 Bticino Spa Push button switch with anti-jamming protection device
US20120067711A1 (en) * 2010-09-16 2012-03-22 Hon Hai Precision Industry Co., Ltd. Electronic device having waterproof button
CN103681061A (en) * 2012-09-11 2014-03-26 罗技欧洲公司 Key frame module for flexible keyboard
US20140262715A1 (en) * 2013-03-15 2014-09-18 Logitech Europe S.A. Keyframe modules for a flexible keyboard
US9390869B2 (en) * 2013-03-15 2016-07-12 Logitech Europe S.A. Keyframe modules for a flexible keyboard

Also Published As

Publication number Publication date
DE2319042B2 (en) 1976-08-19
JPS4920669A (en) 1974-02-23
DE2319042A1 (en) 1973-10-25
GB1431091A (en) 1976-04-07
JPS5418744B2 (en) 1979-07-10
FR2181098A1 (en) 1973-11-30
FR2181098B1 (en) 1977-04-29
CA1006211A (en) 1977-03-01

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