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Publication numberUS3167624 A
Publication typeGrant
Publication dateJan 26, 1965
Filing dateFeb 27, 1962
Priority dateFeb 27, 1962
Publication numberUS 3167624 A, US 3167624A, US-A-3167624, US3167624 A, US3167624A
InventorsJr John Paul Jones
Original AssigneeNavigation Computer Corp
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Permanent magnetic switch
US 3167624 A
Abstract  available in
Images(1)
Previous page
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Claims  available in
Description  (OCR text may contain errors)

Jan. 26, 1965 J. P. JONES, JR 3,167,624

PERMANENT MAGNETIC SWITCH Filed Feb. 27, 1962 FIG. I

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FIG. 3. FIG. 4.

INVENTOR. JOHN PAUL JONES,JR.

United States Patent 3,167,624 PERMANENT MAGNETIC SWITCH John Paul Jones, Jr., Wynnewood, Pa., assignor to Navigation Computer Corporation, a corporation of Pennsylvania Filed Feb. 27, 1962, Ser. No. 175,942 8 Claims. (Cl. 20087) This invention relates to electrical switches and in particular to simple and reliable switches of the magnetic detent type.

Most electrical switches are constructed so they operate with snap action. Snap action swithches have a fast make and break which prevents arcing when high voltages are switched. Moreover, snap action switches have a certain initial resistance which releases suddenly to produce a positive switching action. This latter feature decreases the chance for human error during operation. There are many different switches of the snap action type. Many of these bounce after making initial contact, an undesirable characteristic, particularly in low voltage level electronic circuitry. In addition, most are complicated and therefore expensive to manufacture, particularly if a high packing density is desirable, as in a keyboard or multiswitch panel for operating transistor circuitry.

t is therefore an object of the present invention to provide an improved switch which is simple to construct and reliable in operation.

It is another object of the present invention to provide an improved switch of the magnetic detent type which provides positive switching action in a small amount of space.

It is yet another object of the present invention to provide an improved, simple, and reliable switch which is particularly adaptable for use with printed circuits and transistor circuitry.

A magnetic detent switch embodying the invention comprises a push-button which is fastened to a permanent bar magnet through an aperture in a metallic keyboard panel. The contact portion of the switch comprises two fiat metallic contacts which are mounted in place on, or are part of, a printed circuit board. A leaf spring contact is permanently mounted in engagement with one of the flat contacts and is moved in engagement, by a wiping action, with the other flat contact when the push-button is depressed. In a momentary contact embodiment of the invention, the magnet is attracted to the metallic keyboard panel when the push-button is released, thus disengaging the leaf spring from the one contact. In another embodiment of the invention, the push-button is held in the on position by a metallic member which holds the magnet in place until a current is passed through the metallic member. In still another embodiment, a pair of leaf springs are employed and the push-button and magnet assembly are arranged to alternately engage and disengage the two springs from their contacts.

The novel features that are considered characteristic of this invention are set forth with particularity in the appended claims. The invention itself, however, both as to its organization and method of operation, as well as additional objects and advantages thereof, will best be understood from the following description when read in connection with the accompanying drawing, in which:

FIGURES l and 2 are side elevational views, partially in section, of a magnetic detent switch embodying the invention;

FIGURE 3 is a side elevational view, partially in section, of another embodiment of a magnetic detent switch in accordance with the invention; and

FIGURE 4 is a side elevational view, partially in section, of a magnetic detent switch employing two contacts and embodying the invention.

Referring now to the drawing wherein like parts are indicated by like reference numerals throughout the figurea, and referring particularly to FIG. 1, the push-button 8 of a magnetic detent switch embodying the invention is mounted above an opening in a metallic panel 10. The panel 10, for example, is a keyboard panel of a piece of multiswitch electronic equipment. It would be constructed typically of steel. The push-button is mounted on an angle to the plane of the panel 10 as illustrated. The push-button 8 has retaining grooves on both ends which extend beyond the opening in the panel. The remaining portion of the push-button 8 extends through the opening in the panel 10. A flat, substantially square, permanent bar magnet 12 is attached to the bottom of the push-button assembly. Normally, therefore, the magnet 12 is attracted to the steel panel 10 and remains in the position shown in FIG. I.

The contact portion of the switch includes a semicircular leaf spring 14 which is constructed of a conducting material. One end of the leaf spring 14 is riveted (as shown) or soldered to a printed circuit board 16. The rivet passes through a first printed circuit element 18 which is located between the printed circuit board 16 and the under surface of the leaf spring. The printed circuit element 18 and a second printed circuit element 20, mounted on the board 18 beneath the other end of the leaf spring 14 form the contacts of the switch.

The operation of the switch is more clearly illustrated in FIG. 2, reference to which is now made. Normally, the bar magnet 12 is attracted to the steel panel 10 and stays firmly in the position shown in FIG. 1. When the push-button 8 is manually depressed, however, the magnet 12 is moved downwardly and strikes the leaf spring 14. This action causes the leaf spring 14 to make contact with the printed circuit element 20 with a wiping action, thus closing the switch. When pressure is removed from the push-button 8, the bar magnet 12 is attracted to the steel panel 10 and returns to its original position. The leaf spring 14 at this time also returns to its original position and the switch is opened.

The embodiment of the invention illustrated in FIG. 3, reference to which is now made, provides a hold position for the switch. This is accomplished by providing a metallic strip 22 on the circuit board 16. The strip 22 would be constructed of a magnetic material such as iron. Accordingly, when the push-button S is depressed as shown in FIG. 3, one end of the bar magnet 12 is attracted to the iron strip 22 and is held in the position shown, which is the closed position. In this position, the leaf spring 14 contacts the contact 20 by a wiping action, as in FIG. 2. The bar magnet 12 can be released from this position and the switch opened by passing a current through the iron strip 22 as by a battery 23. A magnetic field is thus created around the strip 22 which repels the magnet 12. This bucking field is sufiicient in magnitude to release the magnet 12 from the strip 22. The magnet 12 is then attracted to the sheet keyboard panel 10 and returns to its original position, similar to the position illustrated in FIG. 1. In this position, the switch is opened.

The switch illustrated in FIG. 4 is arranged so that either one of two switch contacts can be closed by depressing a push-button 24. The push-button 24 is V- shaped and is attached, as in FIGS. 1, 2, and 3, to a permanent bar magnet 12, which in this embodiment of the invention could be slightly longer than the magnets used in the switches of the embodiments previously described. The push-button and magnet assembly is pivoted by means of pivot pin 26. The switch illustrated in FIG. 4 includes two substantially identical contact assemblies 28 and 30 which are attached to the printed circuit board 16 in the same manner as was described for the prior figures.

In operation, when the right hand portion (as viewed in the drawing) of the V-shaped push-button 24 is depressed, the right end of the bar magnet 12 is moved downwardly and strikes the leaf spring of the right-hand contact assembly 30. The spring thus contacts, with a wiping action, the contact on the printed circuit board 16. When the left hand portion of the push-button 24 is depressed the left end of the bar magnet 12 (which had been previously in contact with the steel panel 10) is moved downwardly, thus releasing the right hand contact assembly to the off position and causing the leaf spring of the left hand contact assembly to contact the contact on the printed circuit board.

The embodiment of the invention illustrated in FIG. 4 thus permits two separate circuits to be alternately opened and closed with one push-button. Such a switch would be useful, for example, in changing the binary output of a flip flop circuit from a 1 to a and vice versa.

The switches embodying this invention are simple to construct. Close tolerances are not needed, making the switches economical to manufacture. The switches operate by a snap action and provide an initial resistance to their manual operation, thereby reducing human errors in their operation. A Wiping contact is provided. The initial wiping action absorbs the initial contact energy through friction. This feature avoids the undesirable bounce of many of the prior art switches. In addition, the switches are especially adaptable to Printed Circuit type wiring configurations, which are economical, and are being used in an increasing percentage of all electronic equipment. Thus, reliability, simplicity, economy of manufacture, and ease of operation characterize the switches embodying the invention.

What is claimed is:

1. A magnetic switch comprising, in combination, a panel, a pushbutton having a bottom surface which engages the top surface of said panel when said pushbutton is depressed and said switch is closed, means connecting said pushbutton to a permanent magnet through an aperture in said panel, said magnet being normally attracted to said panel and in fixed engagement thereto when said switch is open, and normally open contact means including a spring-like member arranged to be flexed in response to the downward movement of said pushbutton.

2. A magnetic switch comprising, in combination, a metallic push-button panel, a tapered push-button, the underside of which engages the top surface of said panel when said push-button is depressed and said switch is closed, means connecting said push-button to an elongated permanent magnet through an aperture in said panel, said magnet being normally attracted to the underside of said metallic panel and in fixed engagement thereto when said switch is open, and normally opencontact means including a spring-like member mounted below said magnet and arranged to be flexed in response to the downward movement of said push-button and magnet to close said switch and to provide upward pressure on said magnet when said push-button is released and said switch is open.

3. A magnetic switch comprising, in combination, an apertured push-button panel, a tapered push-button mounted above the aperture in said panel, the underside of said push-button engaging said panel when said push-button is depressed and'said switch is closed, a permanent bar magnet located below the aperture in said panel, means connecting said push-button and said magnet through said aperture to provide an integral push-button assembly, a circuit board mounted in a plane parallel to said push-button panel and below said magnet, a pair of electrical contacts mounted in spaced relationship on said circuit board, a spring-like member, means connecting one end of said spring-like member to one of said contacts, the other end of said spring-like member being arranged in spaced and close relationship to said other contact above said other contact, said spring-like member being arranged to be flexed in response to the downward movement of said pushbutton assembly toprovide a wiping contact of said other end with said other contact to close said switch.

4. A magnetic switch as defined in claim 3, wherein said push-button panel is metallic and said bar magnet is attracted to said panel when said switch is opened to release said spring-like member.

5. A magnetic switch as defined in claim 3, wherein a strip of magnetic metal is mounted on said circuit board adjacent to said one of said contacts and said magnet contacts said strip of metal when said push-button assembly is moved downwardly to hold said switch in the closed position, and means providing a current through said strip to open said switch.

6. A magnetic switch comprising, in combination, an apertured push-button panel, a tapered push-button mounted above the aperture in said panel, the underside of said push-button engaging said panel when said pushbutton is depressed and said switch is closed, means connecting said push-button to a bar magnet through said aperture, said magnet being normally attracted to said panel when said switch is open, a circuit board mounted below said magnet and said panel in a plane parallel thereto, a pair of electrical contacts mounted on said circuit board, a semicircular metallic spring member, means connecting one end of said spring member to one of said contacts and in such relationship to said other of said contacts that the other end of said spring member contacts the other of said contacts in response to the downward movement of said push-button and magnet to close said switch.

7. A magnetic switch as defined in claim 6, wherein metallic means are provided adjacent said one of said contacts ,tO hold said switch in the closed position and means are provided to pass a current through said metallic means to open said switch. 7

8. A magnetic switch comprising, in combination, an apertured push-button panel, a \l-shaped push-button mounted above the aperture in said panel, pivoted means connecting said push-button to an elongated bar magnet through said aperture, a circuit board mounted below said magnet and said panel in a plane parallel thereto, a first and a second pair of electrical contacts mounted on said circuit board, a first and a second metallic spring member, means connecting one end of said first spring member to one of said first pair of electrical contacts and in such relationship to said other of said first pair of electrical contacts that the other end of said first spring member contacts the other of said first pair of electrical contacts in response to the downward movement of one end of said magnet, and means connecting one end of said second spring member to one of said second pair of electrical contacts and in such relationship to said other of said second pair of contacts that the other end of said second spring member contacts the other of said second pair of electrical contacts in response to the downward movement of the other end of said magnet.

References Cited in the file of this patent UNITED STATES PATENTS 2,770,697 Kellett Nov. 13, 1956 2,816,254 Canepa Dec. 10, 1957 2,962,571 Zanichowsky Nov. 29, 1960 2,971,068 Wegner Feb. 7, 1961 3,052,778 Kathe Sept. 4, 1962

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US2770697 *Apr 1, 1954Nov 13, 1956Kellett Alfred LMagnetic electrical switch
US2816254 *Jan 14, 1955Dec 10, 1957Olivetti Corp Of AmericaMagnetic keyboard
US2962571 *Jun 27, 1958Nov 29, 1960Allied Control CoElectric switch
US2971068 *Sep 17, 1958Feb 7, 1961Wegner ClaudeMagnetic switch
US3052778 *Oct 24, 1955Sep 4, 1962Kathe Edmund AElectric switch
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4203093 *Sep 19, 1978May 13, 1980Texas Instruments IncorporatedSolid state keyswitch arrangement
US5283593 *Jul 25, 1988Feb 1, 1994Mannesmann AgInk reservoir for ink printer means having a means to prevent unauthorized refilling
US5977888 *Dec 25, 1996Nov 2, 1999Idec Izumi CorporationSwitching device of thin type and display device with switch
US6069552 *Jun 2, 1999May 30, 2000Duraswitch Industries, Inc.Directionally sensitive switch
US6262646 *Oct 18, 1999Jul 17, 2001Duraswitch Industries, Inc.Island switch
US6369692 *May 9, 2000Apr 9, 2002Duraswitch Industries, Inc.Directionally sensitive switch
US6392515 *Dec 27, 2000May 21, 2002Duraswitch Industries, Inc.Magnetic switch with multi-wide actuator
US7094981Jan 23, 2004Aug 22, 2006Colgate-Palmolive CompanyPowered toothbrush with test button
US8207805 *Mar 17, 2009Jun 26, 2012W. Gessmann GmbhPush-button
US20040152979 *Oct 30, 2003Aug 5, 2004Nemoto Kyorindo Co., Ltd.Liquid injection system for detecting when piston pusher of liquid injector grips piston flange of liquid syringe
US20050161313 *Jan 23, 2004Jul 28, 2005Sorrentino Alan V.Powered toothbrush with test button
US20100236911 *Sep 23, 2010Jorg WildPush-button
DE1515764B1 *Apr 23, 1965Aug 20, 1970Triumph Werke AgSpringschalter
EP0749138A1 *Dec 25, 1995Dec 18, 1996Idec Izumi CorporationThin switch device and display with switch
WO2000074084A1 *Jun 2, 2000Dec 7, 2000Duraswitch Industries, Inc.Directionally sensitive switch
WO2001029854A1 *Oct 11, 2000Apr 26, 2001Duraswitch Industries, Inc.Island switch
WO2001086677A1 *May 8, 2001Nov 15, 2001Duraswitch Industries, Inc.Directionally sensitive switch
Classifications
U.S. Classification335/205, 335/196
International ClassificationH01H5/02
Cooperative ClassificationH01H5/02
European ClassificationH01H5/02