US3809838A - Modular push button switch assembly mounted on printed circuit board - Google Patents

Modular push button switch assembly mounted on printed circuit board Download PDF

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Publication number
US3809838A
US3809838A US00194741A US19474171A US3809838A US 3809838 A US3809838 A US 3809838A US 00194741 A US00194741 A US 00194741A US 19474171 A US19474171 A US 19474171A US 3809838 A US3809838 A US 3809838A
Authority
US
United States
Prior art keywords
plunger
housing
contact
circuit board
switch
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US00194741A
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English (en)
Inventor
J Coppola
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Bunker Ramo Corp
Honeywell International Inc
Original Assignee
Bunker Ramo Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Bunker Ramo Corp filed Critical Bunker Ramo Corp
Priority to US00194741A priority Critical patent/US3809838A/en
Priority to CA150,286A priority patent/CA982203A/en
Priority to JP47091882A priority patent/JPS4857174A/ja
Priority to DE2245751A priority patent/DE2245751A1/de
Priority to GB4338172A priority patent/GB1401316A/en
Application granted granted Critical
Publication of US3809838A publication Critical patent/US3809838A/en
Assigned to ALLIED CORPORATION A CORP. OF NY reassignment ALLIED CORPORATION A CORP. OF NY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: BUNKER RAMO CORPORATION A CORP. OF DE
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/02—Details
    • H01H13/12—Movable parts; Contacts mounted thereon
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
    • H01H13/00—Switches having rectilinearly-movable operating part or parts adapted for pushing or pulling in one direction only, e.g. push-button switch
    • H01H13/02—Details
    • H01H13/10—Bases; Stationary contacts mounted thereon

Definitions

  • ABSTRACT A key switch consisting of a switch mounted on a circuit .board.
  • the switch has at least three contact elements mounted on a plunger which is normally biased away from the circuit board.
  • the contact elements are lowered into engagement with corresponding contact points on the circuit board permitting a coded output to be generated. If one of the contact points on the board is a common point and the contact element on the-plunger adapted to engage the common point is recessed, a simple and effective means is provided for preventing spurious outputs from the switch.
  • This invention relates to a switch adapted for use with a circuit board and more particularly to a key switch or keyboard element including a switch and circuit board, the element generating a coded character output.
  • switches are used extensively in electronic keyboards of processor terminal devices and other related applications. Switches presently used in these applications have, however, suffered from a number of serious deficiencies.
  • these switches which normally include a reed switch and a magnet or other switch activating device, have proved to be the most trouble prone portion of the terminal device.
  • the relatively high profile of these switches has led to alignment problems and this and other factors has contributed to a high incidence of switch sticking.
  • Reliability has also been handicapped by the fact that the switch terminals, and frequently the switch mounting posts, have been soldered to the circuit board on which the switch is mounted. Poor solder joints have resulted in difficultto-detect intermittent problems.
  • a limiting factor in reducing the cost of existing switches is the cost of the reed switch elements.
  • the sealed reed switches are eliminated, the resulting unsealed contacts are subject to contamination problems.
  • a built in wiping action of the contacts as they make and break may overcome this problem.
  • a more specific object of this invention is to provide a switch of the type indicated above which has significantly higher potential reliability than existing switches.
  • a still more specific object of this invention is to provide a switch of the type indicated above which does not require solder joints to physically or electrically connect the switch to a circuit board.
  • Another object of this invention is to provide a switch of the type indicated above which is easier and signifi cantly less expensive to manufacture, assemble into a keyboard, and maintain in the field.
  • a further object of this invention is to provide a keyboard switch with a built-in encoding capability, eliminating the need of a separate encoding circuit.
  • Still another object of this invention is to provide a keyboard switch with a low profile and to thus significantly reduce switch alignment problems.
  • a still further object of this invention is to provide a switch of the type indicated above which provides, in a simple and inexpensive manner, relative immunity to spurious outputs resulting from improper or incomplete (i.e., teasing) closure of the switch.
  • a feature of this invention is the provisions of an inherent wiping action in the switch contacts thereby eliminating potential contamination problems in an unsealed switch.
  • this invention provides a switch adapted for use with a circuit board to form a keyboard element.
  • the circuit board has a plurality of contact points at least one of which is common.
  • the switch is removably mounted on the circuit board by use of a suitable resilient means.
  • the major element of the switch is a plunger having at least three resilient contact elements on the side thereof adjacent the circuit board. The plunger contact elements are aligned to make physical and electrical contact with corresponding contact points on the board when the plunger is depressed.
  • the plunger is, however, normally biased by a suitable means away from the board.
  • Each contact element on the plunger is connected electrically to a contact element adapted to engage a common contact point of the board and the common contact element on the plunger is recessed slightly from the remaining contact elements. This later feature assures that all contacts are engaged before an output is generated, thus preventing spurious outputs.
  • the contact points on the board are coded so as to provide an encoded output representing the character of the keyboard element.
  • FIG. 1 is a partially cutaway, partially exploded, front view of a keyboard element of the invention.
  • FIG. 2 is a top view of the keyboard element shown in FIG. 1.
  • FIG. 4 is a partial, cutaway, side view of a slightly modified version of the element shown in FIG. 1 with the switch in a partially closed position.
  • FIG. Si is a partial, cutaway, side view of the element shown in FIG. 4 with the switch in a fully closed position.
  • FIG. 6 is a perspective view of a switch contact assembly suitable for use with the elements shown in FIGS. 1 5.
  • FIG. 7 is an exemplary semi-schematic top view of a circuit board and related electrical circuitry suitable for use with a preferred embodiment of the invention.
  • FIG. 8 is a view similar to FIG. 2, showing a form of the invention'in which proper plunger orientation is assured.
  • a piston 26 is mounted for vertical movement in housing 14 and consists of an upper portion 28 positioned in bore 18 and a lower portion of enlarged diameter 30 positioned in counterbore 22.
  • Plunger 26 has a pair of flanges 32 which ride in tracks 24 to prevent rotation of plunger 26 in housing 14. Point contact of plunger 26 with housing 14 is provided by a pair of dimples 34 formed on the upper surface of each of the flanges 32.
  • Plunger 26 has an upper counterbore 36 and a lower counterbore 38.
  • a key-head supporting insert 40 is pressure fitted in bore 36. Insert 40 has a discshaped flange 42 and a key-head supporting stem 44.
  • a key-head 46 is pressure fitted on stem 44. It should be noted that while in FIG.
  • Stem 44 is shown as a narrow rectangular-shape post, stem 44 may be hexangular in shape as shown in FIG. 4, may be in the shape of a cross, or may have any other desired shape to accommodate different types of standard key-heads to be fitted thereon.
  • Plunger 26 is normally maintained in the position shown in FIGS. 1 and 3 by a spring 48 which is fitted over portion 16 of body l4 and has flange 42 resting thereon.
  • a contact assembly 50 is staked or otherwise secured to the under side of plunger 26. Holes 51 (FIG. 6) are provided in assembly 50 for this purpose.
  • contact assembly 50 consists of three contact fingers. As may be best seen in FIGS. 3 and 6, the two outer ones of these fingers 52 are facing in one direction while the center finger 54 is facing in the opposite direction. As may be bestseen in FIGS. 1 and 3, center contact 54 is slightly recessed from contacts 52. The reason for this recessing of contact 54 will be described shortly. Also from FIGS. 1, 3, and 6, it can be seen that each of the contact fingers 52 and 54 has a bifurcated end with a projection or radius being formed in each end fork to assure good electrical contact. Dimples 56 formed on the underside of each flange 32 limit the movement of plunger 26 toward board 12. The limited point contact of the plunger with the board reduces the possibility of the key sticking.
  • each of the switches 10 is a pair of mounting posts 60, each of which has a push nut fastener or toggle spring 62 mounted thereon.
  • Springs 62 are adapted to becompressed as posts are passed through openings 64 in board 12 and to expand as shown in FIG. 3 when the switch is mounted on the board to hold the switch in place. Since the upper half 66 of each of the springs 62 is also angled, upward pressure appliedto a mounted switch is effective to cause springs 62 to again be compressed, permitting a switch 10 to be removed. from board 12.
  • the portion of board 12 associated with each keyboard element also includes a pair of outer printed circuitcontacts 68 (FIGS.
  • a center or common printed circuit contact 70 a center or common printed circuit contact 70, a printed circuit spacing dot72 adjacent to each hole 64, and a pair of printed circuit spacing rings 74 at the two corners of the switch which do not contain holes 64.
  • a switch 10 maybe positioned over printed circuit wiring on board 12, in the absence of spacing dots and rings 72 and 74, the switch might not be resting securely on the board and might have a tendency to rock.
  • Printed circuit material 72 and 74 is of the same depth as the printed circuit wiring and assures that rocking of the switch does not occur.
  • the material for spacers 72 and, 74 may be either conductive or nonconductive.
  • each character may be fully characterized by his row and column position in a matrix. Character A is in row 1 column 4 and character B in row 2 column 4. Characters Q and R are in rows 1 and 2 of column 5. It is therefore seen that the left hand contact points 68 for the A and B characters are tied together with printed circuit wiring 78. This line is schematically shown connected as the column 4 (C4) input to character coder 80.
  • C4 column 4
  • the left-hand contact points 68 for the Q and R characters are tied together with a printed circuit line 82, this line being schematically shown as the column 5 (C5) input to coder 80. Since characters A and Q are both in row 1 of the ASCII matrix, the right hand contact points 68 for the characters A and Q are tied together by a common line 84 which is schematically shown as the row 1 (R1) input to coder 80. Similarly, the right hand contact points 68 for the B and R characters are connected together by a printed circuit line 86 whichis shown schematically connected as the row 2 (R2) input to coder 80. The common center contacts 70 for all four characters are shown tied together by a printed circuit line 88 which is schematipression into the seven or eight bit ASCII code for the character.
  • printed circuit lines such as 82 and 84 are schematically shown as crossing, such crossings would not occur on an actual board.
  • the posts 60 of the switch are inserted in corresponding holes 64 of board 12, and the switch is pushed down until the elbow of toggle spring 62 passes the bottom of the board and expands to lock the switch in place. It is apparent that the switch must be inserted with the proper orientation so that contacts 52 are over contacts 68 and contact 54 over contact 70. This may be accomplished by providing a key on one of the posts 60 or springs 62 with a mating groove in a hole 64. However, for the preferred embodiment of the invention shown in the figures, proper orientation is obtained by making one post (post 60A) larger then the other, i
  • Orientationarrows 90 are provided on the top of housing 14 to assist in making the proper orientation decision when assembling the element.
  • the plunger In assembling the switch it is also important that the plunger be properly oriented in housing 14 for the same reason indicated above. As shown in FIG. 8, the flanges 32 and tracks 24 may also be of different size so as to assure proper plunger orientation.
  • the switch In operation, the switch is initially in the position shown in FIGS. 1 and 3 being biased to that position by the action of the spirng 48.
  • plunger 26 When pressure is applied to a key top 46, plunger 26 is depressed to the position shown in FIG. 4. In this position, contacts 52 on plunger 26 are in contact with contacts 68 on board 12, but contact 54 is not yet touching contact 70. Since contact 70 is the common contact, an open circuit condition still exists at this time. Contact 54 being recessed from contacts 58 thus prevents spurious outputs from being generated as a result of the partial depression of plunger 26.
  • FIG. 5 shows the switch in its fully closed condition.
  • a switch and keyboard element has thus been provided which is capable of directly generating coded outputs, eliminating the need for a diode matrix or other character encoding circuit. Further, since the switch has a minimum of parts, not requiring either a reed switch or a magnet, the materials cost for the 6. switch are minimal. The cost of the switch 10 has been found to be roughly 30 percent of the cost of existing reed keyboard switches. Similarly, since there are no soldering operations involved in the assembly operation, and encoding circuitry may be eliminated, the cost of assembling the switch into a keyboard element has also been found to be roughly 20 to 30 percent of the cost for existing reed switches. The resulting keyboard element may thus be obtained for roughly 25 percent of the cost of existing keyboard elements.
  • this switch may provide a relatively low profile, thereby significantly reducing switch alignment problems. The lower profile also reduces the likelihood of switch sticking and related problems. Further, since electrical contact is made through contact assembly 50 mounted directly on the plunger and mechanical securing of the switch is achieved through a toggle spring 62, soldering, with the numerous problems incident thereto mentioned above is totally eliminated. A switch which may be easily installed or removed in the field for maintenance or other purposes is thus provided. Other advantages which have been indicated above include an inherent wiping action which improves reliability by removing contaminants from the contacts and an anti-teasing action achievedby the recessing of center contact 54 to prevent spurious outputs from being generated. Since the anti-teasing mechanism introduces no additional parts into the switch, this desirable feature is achieved with minimal if any effect on switch cost. Insert 40 also permits the key tops.
  • each contact finger 52' which is not adapted to make contact with a common contact on the board be electrically connected to a finger 54 which is to make contact with a common contact 70.
  • the key switch element of this invention is thus adapted to prokey switch to be easily modified to accept a variety of -vide a wide variety of coded'outputs.
  • a modular contact unit for cooperating with conductive contact pads on a circuit board to form a switch mechanism, said contact unit comprising a housing of electrically insulating material, externally substantially polygonal in plan shape, having a centrally located circular sleeve extending upwardly therefrom, a plunger extending through said sleeve from the inside of said housing, the inside of said housing having a bore of generally circular shape, open at the bottom, with a pair of axially extending grooves formed in the sides of said bore adjacent to diagonally opposite corners of the outside of said housing, said plunger having a lower portion of enlarged diameter freely movable axially in said bore, said lower portion having flanges fitting in said I grooves to prevent rotation of said lower portion in said bore, there being a shoulder between the inner end of said sleeve and said bore, spring means tending to move said plunger to a raised position, a multiple leaf spring contact carried on said lower portion, adapted for engagement with contact pads
  • detent spring retainers consist of split rings frictionally fitted on said posts, said rings each carrying a plurality of axially extending outwardly bowed leaf springs, the ends of said springs opposite said rings bearing against said posts adjacent to said housing.
  • a modular contact unit for cooperating with conductive contact pads on a circuit board to form a switch mechanism, said contact unit comprising a housing of electrically insulating material having an axially extending bore therein, a spring-biased plunger slidably carried in said bore, a portion of said plunger extending externally of said housing and adapted for connection to a key head, a multiple finger spring contact carried on said plunger.within said bore, said contact having two fingers extending toward one side of said housing and at least one finger extending toward the opposite side of said housing, keying means on said housing and said'plunger controlling the rotational orientation of said plunger and said contact with respect to said housing, and means for mounting said contact unit on a circuit board having contact pads and receiving holes appropriately located with reference to said pads, said mounting means consisting of a plurality of posts extending from the bottom of said housing, en gageable in said receiving holes in said circuit board, and detent means retaining said posts in said holes, being receivable in said holes only in a predetermined orientation

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  • Push-Button Switches (AREA)
US00194741A 1971-11-01 1971-11-01 Modular push button switch assembly mounted on printed circuit board Expired - Lifetime US3809838A (en)

Priority Applications (5)

Application Number Priority Date Filing Date Title
US00194741A US3809838A (en) 1971-11-01 1971-11-01 Modular push button switch assembly mounted on printed circuit board
CA150,286A CA982203A (en) 1971-11-01 1972-08-23 Circuit board switch
JP47091882A JPS4857174A (enrdf_load_stackoverflow) 1971-11-01 1972-09-14
DE2245751A DE2245751A1 (de) 1971-11-01 1972-09-18 Schalter
GB4338172A GB1401316A (en) 1971-11-01 1972-09-19 Modular contact unit for circuit board

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US00194741A US3809838A (en) 1971-11-01 1971-11-01 Modular push button switch assembly mounted on printed circuit board

Publications (1)

Publication Number Publication Date
US3809838A true US3809838A (en) 1974-05-07

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ID=22718740

Family Applications (1)

Application Number Title Priority Date Filing Date
US00194741A Expired - Lifetime US3809838A (en) 1971-11-01 1971-11-01 Modular push button switch assembly mounted on printed circuit board

Country Status (5)

Country Link
US (1) US3809838A (enrdf_load_stackoverflow)
JP (1) JPS4857174A (enrdf_load_stackoverflow)
CA (1) CA982203A (enrdf_load_stackoverflow)
DE (1) DE2245751A1 (enrdf_load_stackoverflow)
GB (1) GB1401316A (enrdf_load_stackoverflow)

Cited By (22)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5167379U (enrdf_load_stackoverflow) * 1974-11-25 1976-05-27
US4122319A (en) * 1976-02-11 1978-10-24 Euratom Electrical switch and its use for the control of machines
US4450332A (en) * 1982-08-25 1984-05-22 General Instrument Corporation Keyswitch design
US4496803A (en) * 1983-05-04 1985-01-29 Key Concepts, Incorporated Data entry switch
GB2177849A (en) * 1985-07-04 1987-01-28 George Brian Todd Push button control unit for valve or switch
US4709128A (en) * 1983-05-17 1987-11-24 Canon Kabushiki Kaisha Easily positionable keyboard
US4845320A (en) * 1986-10-01 1989-07-04 Metro Denso Kabushiki Kaisha Time difference switch
US4894499A (en) * 1987-09-30 1990-01-16 Contraves Ag Electric push-button switch
US5422448A (en) * 1992-11-17 1995-06-06 Smk Corp. Contact piece for use in a rotary encoder and method of constructing same
US5744766A (en) * 1996-07-24 1998-04-28 Allen-Bradley Company, Inc. Slide or reciprocating switch with s-shaped bridging-or spanner contact
US6107586A (en) * 1997-11-13 2000-08-22 Matsushita Electric Industrial Co., Ltd. Push-on switch
EP1221517A3 (en) * 2001-01-03 2003-11-12 Emerson Electric Co. Door unlatch switch assembly
US20040045494A1 (en) * 2001-10-31 2004-03-11 Hideto Baba Vehicle meter
US20040112730A1 (en) * 2002-12-16 2004-06-17 Trw Inc. Electrical switch assembly
US20040154907A1 (en) * 2002-12-16 2004-08-12 Trw Automotive U.S. Llc Electrical switch assembly
US20050087429A1 (en) * 2003-10-24 2005-04-28 Trw Automotive U.S. Llc Rocker switch
EP1528583A1 (en) * 2003-10-28 2005-05-04 SMK Korea Co., Ltd. Key-top
US7083434B1 (en) * 2005-03-10 2006-08-01 Trw Automotive Us Llc Electrical apparatus with compliant pins
US20090042453A1 (en) * 2007-08-10 2009-02-12 Chi Mei Communication Systems, Inc. Contact spring assembly for electronic devices
US7498538B1 (en) * 2007-07-20 2009-03-03 Judco Manufacturing, Inc. Sliding contact switch
US20100276267A1 (en) * 2009-05-01 2010-11-04 King Enterprises Switch assembly
US20150144466A1 (en) * 2013-11-27 2015-05-28 The Eastern Company Electrical switch operated by lockable push button actuator, and retrofit method and kit

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5431909Y2 (enrdf_load_stackoverflow) * 1975-03-24 1979-10-04
JPS5810985Y2 (ja) * 1976-03-22 1983-03-01 松下電工株式会社 押釦開閉器
JPS528175U (enrdf_load_stackoverflow) * 1976-06-28 1977-01-20
JPS5852578Y2 (ja) * 1977-06-21 1983-11-30 富士通株式会社 キ−ボ−ド装置
JPH055623Y2 (enrdf_load_stackoverflow) * 1988-04-08 1993-02-15
TW201501155A (zh) 2013-06-28 2015-01-01 Giga Byte Tech Co Ltd 鍵帽、按鍵結構及具有此按鍵結構之鍵盤

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US2383735A (en) * 1943-04-02 1945-08-28 William A Ray Rectifier
US2568535A (en) * 1945-04-10 1951-09-18 Charles E Ballard Board for demonstrating electric circuits
US2619215A (en) * 1950-08-22 1952-11-25 Toledo Scale Co Mounting for key buttons
US2752580A (en) * 1953-04-27 1956-06-26 Charles A Shewmaker Printed circuit board and terminal connections
US2885602A (en) * 1955-04-04 1959-05-05 Ncr Co Modular circuit fabrication
US3210484A (en) * 1962-04-20 1965-10-05 Automatic Elect Lab Push button device
US3240885A (en) * 1963-05-07 1966-03-15 Western Electric Co Multiple switching apparatus
US3499515A (en) * 1967-12-11 1970-03-10 Synergistics Inc Modular electrical keyboard
US3506795A (en) * 1967-10-24 1970-04-14 Raymond F Schmidt Electrical switch device
US3586806A (en) * 1969-05-02 1971-06-22 Essex International Inc Bistable reciprocable switch construction
US3641286A (en) * 1970-10-05 1972-02-08 Selectro Corp Electromechanical keyboard independently operated switch mechanism with improved conductive resilient actuating means
US3696408A (en) * 1970-11-23 1972-10-03 Sanders Associates Inc Keyboard encoder
US3696908A (en) * 1970-11-09 1972-10-10 Sperry Rand Corp Capacitive key
US3707611A (en) * 1969-10-15 1972-12-26 Mechanical Enterprises Inc Coding keyboard and electrical switch therefor
US3710060A (en) * 1971-07-01 1973-01-09 Bunker Ramo Push-button switch for mounting on printed circuit board
US3749872A (en) * 1970-04-01 1973-07-31 Sumlock Anita Electronics Ltd Switch mounted on printed circuit board

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2383735A (en) * 1943-04-02 1945-08-28 William A Ray Rectifier
US2568535A (en) * 1945-04-10 1951-09-18 Charles E Ballard Board for demonstrating electric circuits
US2619215A (en) * 1950-08-22 1952-11-25 Toledo Scale Co Mounting for key buttons
US2752580A (en) * 1953-04-27 1956-06-26 Charles A Shewmaker Printed circuit board and terminal connections
US2885602A (en) * 1955-04-04 1959-05-05 Ncr Co Modular circuit fabrication
US3210484A (en) * 1962-04-20 1965-10-05 Automatic Elect Lab Push button device
US3240885A (en) * 1963-05-07 1966-03-15 Western Electric Co Multiple switching apparatus
US3506795A (en) * 1967-10-24 1970-04-14 Raymond F Schmidt Electrical switch device
US3499515A (en) * 1967-12-11 1970-03-10 Synergistics Inc Modular electrical keyboard
US3586806A (en) * 1969-05-02 1971-06-22 Essex International Inc Bistable reciprocable switch construction
US3707611A (en) * 1969-10-15 1972-12-26 Mechanical Enterprises Inc Coding keyboard and electrical switch therefor
US3749872A (en) * 1970-04-01 1973-07-31 Sumlock Anita Electronics Ltd Switch mounted on printed circuit board
US3641286A (en) * 1970-10-05 1972-02-08 Selectro Corp Electromechanical keyboard independently operated switch mechanism with improved conductive resilient actuating means
US3696908A (en) * 1970-11-09 1972-10-10 Sperry Rand Corp Capacitive key
US3696408A (en) * 1970-11-23 1972-10-03 Sanders Associates Inc Keyboard encoder
US3710060A (en) * 1971-07-01 1973-01-09 Bunker Ramo Push-button switch for mounting on printed circuit board

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS5167379U (enrdf_load_stackoverflow) * 1974-11-25 1976-05-27
US4122319A (en) * 1976-02-11 1978-10-24 Euratom Electrical switch and its use for the control of machines
US4450332A (en) * 1982-08-25 1984-05-22 General Instrument Corporation Keyswitch design
US4496803A (en) * 1983-05-04 1985-01-29 Key Concepts, Incorporated Data entry switch
US4709128A (en) * 1983-05-17 1987-11-24 Canon Kabushiki Kaisha Easily positionable keyboard
GB2177849A (en) * 1985-07-04 1987-01-28 George Brian Todd Push button control unit for valve or switch
US4845320A (en) * 1986-10-01 1989-07-04 Metro Denso Kabushiki Kaisha Time difference switch
US4894499A (en) * 1987-09-30 1990-01-16 Contraves Ag Electric push-button switch
US5422448A (en) * 1992-11-17 1995-06-06 Smk Corp. Contact piece for use in a rotary encoder and method of constructing same
US5744766A (en) * 1996-07-24 1998-04-28 Allen-Bradley Company, Inc. Slide or reciprocating switch with s-shaped bridging-or spanner contact
US6107586A (en) * 1997-11-13 2000-08-22 Matsushita Electric Industrial Co., Ltd. Push-on switch
EP1221517A3 (en) * 2001-01-03 2003-11-12 Emerson Electric Co. Door unlatch switch assembly
US20040045494A1 (en) * 2001-10-31 2004-03-11 Hideto Baba Vehicle meter
US6910439B2 (en) * 2001-10-31 2005-06-28 Nippon Seiki Co., Ltd. Vehicle meter
US20040154907A1 (en) * 2002-12-16 2004-08-12 Trw Automotive U.S. Llc Electrical switch assembly
US20040112730A1 (en) * 2002-12-16 2004-06-17 Trw Inc. Electrical switch assembly
US6984796B2 (en) * 2002-12-16 2006-01-10 Trw Inc. Electrical switch assembly
US7030325B2 (en) 2002-12-16 2006-04-18 Trw Automotive U.S. Llc Electrical switch assembly
US20050087429A1 (en) * 2003-10-24 2005-04-28 Trw Automotive U.S. Llc Rocker switch
US6974918B2 (en) * 2003-10-24 2005-12-13 Trw Automotive U.S. Llc Rocker switch
EP1528583A1 (en) * 2003-10-28 2005-05-04 SMK Korea Co., Ltd. Key-top
US7083434B1 (en) * 2005-03-10 2006-08-01 Trw Automotive Us Llc Electrical apparatus with compliant pins
US7498538B1 (en) * 2007-07-20 2009-03-03 Judco Manufacturing, Inc. Sliding contact switch
US20090042453A1 (en) * 2007-08-10 2009-02-12 Chi Mei Communication Systems, Inc. Contact spring assembly for electronic devices
US7578712B2 (en) * 2007-08-10 2009-08-25 Chi Mei Communication Systems, Inc. Contact spring assembly for electronic devices
US20100276267A1 (en) * 2009-05-01 2010-11-04 King Enterprises Switch assembly
US8203090B2 (en) * 2009-05-01 2012-06-19 King Enterprises Switch assembly
US20150144466A1 (en) * 2013-11-27 2015-05-28 The Eastern Company Electrical switch operated by lockable push button actuator, and retrofit method and kit
US9728351B2 (en) * 2013-11-27 2017-08-08 The Eastern Company Electrical switch operated by lockable push button actuator, and retrofit method and kit

Also Published As

Publication number Publication date
GB1401316A (en) 1975-07-16
JPS4857174A (enrdf_load_stackoverflow) 1973-08-10
DE2245751A1 (de) 1973-05-10
CA982203A (en) 1976-01-20

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