US3165608A - Magnetic switching apparatus for reducing contact bounce - Google Patents

Magnetic switching apparatus for reducing contact bounce Download PDF

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Publication number
US3165608A
US3165608A US246604A US24660462A US3165608A US 3165608 A US3165608 A US 3165608A US 246604 A US246604 A US 246604A US 24660462 A US24660462 A US 24660462A US 3165608 A US3165608 A US 3165608A
Authority
US
United States
Prior art keywords
reed
contact
elements
reeds
bounce
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
US246604A
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English (en)
Inventor
Joseph E Wallace
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.)
International Business Machines Corp
Original Assignee
International Business Machines 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
Priority to NL301314D priority Critical patent/NL301314A/xx
Priority to NL136806D priority patent/NL136806C/xx
Application filed by International Business Machines Corp filed Critical International Business Machines Corp
Priority to US246604A priority patent/US3165608A/en
Priority to GB45927/63A priority patent/GB987207A/en
Priority to DEJ24875A priority patent/DE1188720B/de
Priority to AT984763A priority patent/AT246838B/de
Priority to CH1541363A priority patent/CH415795A/de
Priority to DK590763AA priority patent/DK105422C/da
Priority to FI251263A priority patent/FI40020C/fi
Priority to FR957733A priority patent/FR1377825A/fr
Priority to BE641541A priority patent/BE641541A/xx
Priority to ES0294709A priority patent/ES294709A1/es
Application granted granted Critical
Publication of US3165608A publication Critical patent/US3165608A/en
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
    • H01H51/00—Electromagnetic relays
    • H01H51/28—Relays having both armature and contacts within a sealed casing outside which the operating coil is located, e.g. contact carried by a magnetic leaf spring or reed
    • H01H51/287—Details of the shape of the contact springs

Definitions

  • FIG. 1 is a diagrammatic representation of the first figure.
  • the usual magnetic reed switch comprises a pair of spaced, overlapping, magnetic reeds supported in cantilever fashion in the opposite ends of a sealed glass tube about which is provided an exciter or energizing coil. Current flowing through the coil produces a magnetic flux field which attracts the free ends of the reeds toward each other and completes the conduction path from one reed to the other.
  • the reeds are made of thin, relatively flexible magnetic material with an air gap of a few thousandths of an inch between the free ends to permit high speed switch operation.
  • the reed contacts are sealed free of contaminants to provide excellent operational reliability.
  • Another object of this invention is to provide a relatively simple and inexpensive reed switch having little or no contact bounce.
  • Still another object of this invention is to provide a magnetically operated reed switch in which the kinetic energy of approaching reeds is significantly reduced at the instant of impact.
  • a further object of this invention is to provide a magnetically operated reed switch which includes a fixed limit stop for one of the two approaching reeds operable to arrest or reverse the motion of one of the reeds prior to imp-act of the reeds.
  • this invention provides a fixed stop secured in the switch enclosure adjacent one of the magnetic reed cantilevers and spaced therefrom less than half the gap between the overlapping cantilever contacts when the latter are in a d e-energized position.
  • a magnetic fiux field When a magnetic fiux field is applied, each reed moves toward the other to minimize reluctance.
  • One reed is arrested by the stop, however, before impact with the remaining reed so that its approach velocity reaches zero and then becomes a negative value as it rebounds from the stop while being overtaken by the remaining moving reed.
  • This arrangement eliminates special forming or shaping of the reeds and avoids the addition of auxiliary reeds or electrical contact areas of the principal reeds. Less kinetic energy at impact time also prolongs the life of the contact area.
  • PEG. 1 is a sectional side elevation view of an electromagnetic reed switch constructed in accordance with the invention.
  • FIGS. 2a and 2b are comparative oscillographic diagrams illustrating the contact action in reed switches which respectively do not and do embody the invention.
  • reeds l0 and 11 of a suitable ferromagnetic material are supported in substantially parallel planes as cantilever beams in the opposite ends of a sealed glass enclosure 12 encircled by an energizing electromagnetic coil 13 (shown in phantom).
  • Reeds 10 and 11 each have approximately equal movable lengths from hinge points 14, and their respective free ends 15 and 16 overlap and are spaced from each other a predetermined distance to provide a gap which is usually a few thous-andths of an inch. The spacing depends on the current requirement, voltage and operating time of the particular circuit in which the reed switch is used.
  • the reed ends may each be plated with a suitable material at the contact area to improve the electrical connection.
  • a member 17 having an upturned end 18 which serves as a stop to limit the downward movement of reed 10.
  • End 13 is preferably positioned near the contact area to minimize the whipping action upon impact between reed 10 and end 18.
  • the end of the stop member has a substantially flat surface which is spaced from reed 10 at a distance less than half the gap between ends 15 and 16. This spacing will vary according to the distance end 18 is located from the reed gap.
  • the Stop Member 17 has a relatively large mass compared to reed 10 so that it presents a substantially rigid stop for the reed.
  • the stop member 17 is preferably a hardened non-magnetic material to reduce wear and to avoid any effect upon the make or break time of the reeds.
  • coil 13 is supplied with current which establishes magnetic flux lines passing through reeds 10 and 11.
  • the reeds move toward each other with approximately equal acceleration and velocity to decrease the magnetic reluctance of gap. While reed 11 continues moving toward reed 10, reed 10 strikes the stop surface of end 18 so that its movement is arrested. Because of the kinetic energy of reed 10 and relative inflexibility of member 17, the reed rebounds and moves away from approaching reed 11. The latter reed, however, is moving at a higher velocity and overtakes reed 10. The result is that ends 15 and 16 make contact at low relative velocity with a low impact energy because they are traveling in the same direction when impact occurs.
  • FIGS. 2a and 2b show the contact action of the reed switch described above.
  • FIGS. 2a and 2b show the voltage drop across a load resistor in series with the switch contacts.
  • FIG. 2a represents the reed switch action without a stop
  • FIG. 2b represents the switch closure using stop member 17 positioned as shown in FIG. 1.
  • coil 13 having a winding of 10,000 turns of No. 42 wire and 1600 ohms resistance was energized with twelve volts D.C. Free ends 15 and 16 of the reeds were spaced .003 inch and the stop surface of end 18 was spaced .001 inch from the underside of reed 10.
  • the switch contacts first closed after approximately 560 microseconds (,uS.) after coil energization and then opened again approximately ,uS. later because of bounce.
  • switch closure occurred approximately 700 s. after coil energization with no subsequent bounce.
  • stop member 17 eliminated contact bounce and prevented the production of extraneous pulses in the switch circuit. This permits the immediate utilization of the switch circuit without the necessity of a delay to let the switch contacts stabilize.
  • End 18 of he stop member is preferably positioned from reed It at less than half the gap between the free ends of the reeds. This assures that, when the coil is energized, reed it) will start its rebound from the stop before the reeds seal. If the stop is positioned too close to reed it the reed will have become stationary before impact by end 16 of reed 11 so that operating time will increase and bounce will occur.
  • An electrical switching device comprising:
  • An electromlagnetically controlled switching device comprising: a
  • a switching device wherein the stop surface is disposed adjacent the unsupported end of said other element, and both said elements and the stop surface-providing means are sealed within a common:
  • a switching device wherein said elements are substantially parallel in the absence of said magnetic field and are supported to have substantially equal movable lengths.

Landscapes

  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Switches That Are Operated By Magnetic Or Electric Fields (AREA)
  • Switches Operated By Changes In Physical Conditions (AREA)
  • Mechanisms For Operating Contacts (AREA)
  • Manufacture Of Switches (AREA)
US246604A 1962-12-21 1962-12-21 Magnetic switching apparatus for reducing contact bounce Expired - Lifetime US3165608A (en)

Priority Applications (12)

Application Number Priority Date Filing Date Title
NL301314D NL301314A (cs) 1962-12-21
NL136806D NL136806C (cs) 1962-12-21
US246604A US3165608A (en) 1962-12-21 1962-12-21 Magnetic switching apparatus for reducing contact bounce
GB45927/63A GB987207A (en) 1962-12-21 1963-11-21 Electrical switching device
DEJ24875A DE1188720B (de) 1962-12-21 1963-12-07 Schutzrohr-Relaiskontakt
AT984763A AT246838B (de) 1962-12-21 1963-12-09 Schutzrohr-Relaiskontakt
CH1541363A CH415795A (de) 1962-12-21 1963-12-16 Schutzrohr-Relaiskontakt
DK590763AA DK105422C (da) 1962-12-21 1963-12-18 Elektromagnetisk koblingsorgan.
FI251263A FI40020C (fi) 1962-12-21 1963-12-18 Elektromagnetisk kopplingsanordning
FR957733A FR1377825A (fr) 1962-12-21 1963-12-19 Appareil de commutation magnétique
BE641541A BE641541A (cs) 1962-12-21 1963-12-19
ES0294709A ES294709A1 (es) 1962-12-21 1963-12-20 Un dispositivo de distribuciën electrico

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US246604A US3165608A (en) 1962-12-21 1962-12-21 Magnetic switching apparatus for reducing contact bounce

Publications (1)

Publication Number Publication Date
US3165608A true US3165608A (en) 1965-01-12

Family

ID=22931366

Family Applications (1)

Application Number Title Priority Date Filing Date
US246604A Expired - Lifetime US3165608A (en) 1962-12-21 1962-12-21 Magnetic switching apparatus for reducing contact bounce

Country Status (10)

Country Link
US (1) US3165608A (cs)
AT (1) AT246838B (cs)
BE (1) BE641541A (cs)
CH (1) CH415795A (cs)
DE (1) DE1188720B (cs)
DK (1) DK105422C (cs)
ES (1) ES294709A1 (cs)
FI (1) FI40020C (cs)
GB (1) GB987207A (cs)
NL (2) NL136806C (cs)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3229063A (en) * 1963-12-11 1966-01-11 Gen Reed Company Electromagnetic reed switch
US3315193A (en) * 1964-11-12 1967-04-18 Briggs & Stratton Corp Reed switch adapted for rapid cycling
US3399190A (en) * 1965-05-21 1968-08-27 Olin Mathieson Phosphorous containing starch oxyalkylated polyethers and their preparation
US3426302A (en) * 1966-10-31 1969-02-04 Bell Telephone Labor Inc Sealed reed switch with adjustable reed
US4295024A (en) * 1979-09-24 1981-10-13 A. B. Chance Company Spring biased energy absorber for vacuum switch contact shafts
US4311891A (en) * 1980-04-17 1982-01-19 Abc Auto Alarms, Inc. Vehicle alarm shaker device with spring damper

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2535400A (en) * 1949-08-25 1950-12-26 Bell Telephone Labor Inc Multicontact dry reed relay
FR1237011A (fr) * 1958-10-20 1960-07-22 Siemens Ag Perfectionnement aux contacts sous tube de protection
US3025371A (en) * 1961-05-05 1962-03-13 Medal Einar Shockproof magnetic reed switch

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2535400A (en) * 1949-08-25 1950-12-26 Bell Telephone Labor Inc Multicontact dry reed relay
FR1237011A (fr) * 1958-10-20 1960-07-22 Siemens Ag Perfectionnement aux contacts sous tube de protection
US3025371A (en) * 1961-05-05 1962-03-13 Medal Einar Shockproof magnetic reed switch

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3229063A (en) * 1963-12-11 1966-01-11 Gen Reed Company Electromagnetic reed switch
US3315193A (en) * 1964-11-12 1967-04-18 Briggs & Stratton Corp Reed switch adapted for rapid cycling
US3399190A (en) * 1965-05-21 1968-08-27 Olin Mathieson Phosphorous containing starch oxyalkylated polyethers and their preparation
US3426302A (en) * 1966-10-31 1969-02-04 Bell Telephone Labor Inc Sealed reed switch with adjustable reed
US4295024A (en) * 1979-09-24 1981-10-13 A. B. Chance Company Spring biased energy absorber for vacuum switch contact shafts
US4311891A (en) * 1980-04-17 1982-01-19 Abc Auto Alarms, Inc. Vehicle alarm shaker device with spring damper

Also Published As

Publication number Publication date
ES294709A1 (es) 1964-03-01
CH415795A (de) 1966-06-30
DK105422C (da) 1966-09-26
NL136806C (cs)
FI40020B (cs) 1968-05-31
BE641541A (cs) 1964-04-16
DE1188720B (de) 1965-03-11
FI40020C (fi) 1968-09-10
NL301314A (cs)
GB987207A (en) 1965-03-24
AT246838B (de) 1966-05-10

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