EP0056624A2 - Switch assembly - Google Patents
Switch assembly Download PDFInfo
- Publication number
- EP0056624A2 EP0056624A2 EP82100243A EP82100243A EP0056624A2 EP 0056624 A2 EP0056624 A2 EP 0056624A2 EP 82100243 A EP82100243 A EP 82100243A EP 82100243 A EP82100243 A EP 82100243A EP 0056624 A2 EP0056624 A2 EP 0056624A2
- Authority
- EP
- European Patent Office
- Prior art keywords
- contact
- switch assembly
- magnetic body
- elongated
- contact member
- 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.)
- Granted
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Classifications
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H50/00—Details of electromagnetic relays
- H01H50/54—Contact arrangements
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/12—Contacts characterised by the manner in which co-operating contacts engage
- H01H1/14—Contacts characterised by the manner in which co-operating contacts engage by abutting
- H01H1/20—Bridging contacts
- H01H1/2041—Rotating bridge
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H1/00—Contacts
- H01H1/50—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position
- H01H1/54—Means for increasing contact pressure, preventing vibration of contacts, holding contacts together after engagement, or biasing contacts to the open position by magnetic force
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H50/00—Details of electromagnetic relays
- H01H50/02—Bases; Casings; Covers
- H01H50/023—Details concerning sealing, e.g. sealing casing with resin
- H01H2050/025—Details concerning sealing, e.g. sealing casing with resin containing inert or dielectric gasses, e.g. SF6, for arc prevention or arc extinction
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H59/00—Electrostatic relays; Electro-adhesion relays
- H01H2059/009—Electrostatic relays; Electro-adhesion relays using permanently polarised dielectric layers
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H57/00—Electrostrictive relays; Piezo-electric relays
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- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H59/00—Electrostatic relays; Electro-adhesion relays
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01H—ELECTRIC SWITCHES; RELAYS; SELECTORS; EMERGENCY PROTECTIVE DEVICES
- H01H7/00—Devices for introducing a predetermined time delay between the initiation of the switching operation and the opening or closing of the contacts
- H01H7/16—Devices for ensuring operation of the switch at a predetermined point in the ac cycle
Definitions
- the present invention relates to a switch assembly and, more particularly, to an improved switch assembly capable of being used for cutting and supplying high a.c. power.
- a switch assembly having at least one pair of contacts transmits a high a.c. power
- the current flowing through the switch assembly varies from positive maximum point through a zero crossing point to a negative maximum point and vice versa as in a sinusoidal waveform.
- the switch assembly cuts, or breaks, the current at the zero crossing point
- the contacts may separate away from each other without producing any arc.
- an arc may be produced between the contacts, and this possibility is high as the cutting is effected closer to the maximum point of the a.c. current. If the arc is once produced, it continues until the next zero crossing point comes.
- phase detector in combination with a switch assembly to effecting the cutting of the switch assembly in synchronized relation to the detection of zero crossing point by the phase detector.
- a switch assembly comprises first and second contact means provided operatively to take one of two positions, a break-position in which the first and second contact means are electrically separated from each other, and a make-position in which the first and second contact means are electrically connected with each other to define a current path therethrough, first and second magnetic bodies provdied operatively in association with said first and second contact means such that said first and second magnetic bodies define at least one closed magnetic loop with at least one of said first and second contact means passing through said closed magnetic loop when said first and second contact means are turned to said make-position, and said magnetic loop opens when said first and second contact means are turned to said break-position, biasing means for biasing said first and second contact means towards said break-position, and actuating means for actuating said first and second contact means towards said make-position against said biasing means.
- the switch assembly of the first embodiment comprises a framework 2 made of electrically non-conductive material, such as synthetic resin, a yoke 4 made of magnetic material, such as iron, and rigidly supported by the frame 2, a see-saw plate 6 made of magnetic material, such as iron, and rotatably supported by the frame 2, a coil 8 mounted on the yoke 4, and first and second contact members 10 and 12 which are electrically insulated from each other and from the yoke 4 and see-saw plate 6.
- the structure of the switch assembly of the first embodiment is described in detail below with reference to Fig. 2 schematically showing the switch assembly without the framework 2 and Fig. 3 showing a cross-sectional view taken along a line III-III shown in Fig. 2.
- the yoke 4 as best shown in Fig. 2, has an "S" shape configuration defined by three horizontal bars 4a, 4b and 4c aligned parallelly to each other and two vertical bars 4d and 4e. As apparent from Figs. 2 and 3, the bars 4b, 4c, 4d and 4e extend in the same plane, whereas the bar 4a extends above said plane.
- the coil 8 is mounted on the bar 4d of the yoke 4 and is electrically connected to a switch 14 and a power source 16 in series.
- the power source 16 shown in Fig. 2 is a d.c. power source, such as a battery, but it can be an a.c. power source.
- the coil 8 is provided for magnetizing particularly the bars 4a and 4b of the yoke 4 when the switch 14 is closed.
- the see-saw plate 6 is so long that its one end locates under the bar 4a and the other end locates above the bar 4c of the yoke 4.
- a pair of pins 6a and 6b are provided approximately at the center of the see-saw plate 6 for the engagement with corresponding recesses or openings (not shown) formed in the framework 2 so that the see-saw plate 6 may rotate about the pins 6a and 6b.
- the clockwise rotation of the see-saw plate 6 is restricted by the framework 2 to terminate in a position shown in Fig. 3.
- the counterclockwise rotation of the see-saw plate 6 is restricted by the contact members 10 and 12 as will become apparent from the description below.
- the first contact member 10 has a "T" shaped portion, as shown in Fig. 1, defined by arms 10a and 10b such that the arm 10b extends perpendicularly from the center of the arm 10a.
- the opposite ends of the arm 10a of the contact member 10 are rigidly supported by the framework 2 and the arm 10b extends over the see-saw plate 6.
- the arm lOb serving as a leaf spring, is slightly bent downwardly with respect to the arm 10a so that the end of the arm 10b remote from the arm 10a contacts and pushes the see-saw plate 6 to the position shown in Fig. 3.
- a contact point 10c is mounted on the end portion of the arm lOb, as best shown in Fig. 3. Since there is no framework 2 shown in Figs. 2 and 3, the arm 10a of the contact member 10 is not apparently shown in these Figs. 2 and 3.
- the first contact member further includes an arm 10d connected to the arm 10a and extends in a space between the see-saw plate 6 and bar 4e of the yoke 4 and further extends in the direction away from the bar 4e under the see-saw plate 6, and terminates to a terminal leg 10e for the external connection.
- the second contact member 12 has an "L" shaped portion, as shown in Figs. 1 and 2, defined by arms 12a and 12b.
- a contact point 12c is mounted on the end portion of the arm 12a in face-to-face relation with the contact point 10c. Since the arms 12a and 12b are made of hard metallic plate and are rigidly supported by the frame 2, the arm 12a stops the rotation of see-saw plate 6 upon contact of the contact points 10c and 12c with a very small degree of bending of the arms 12a and 12b.
- the contact member 12 further includes an arm 12d connected to the arm 12b and extends, as best shown in Fig. 2, towards the bar 4e of the yoke 4 under the see-saw plate 6.
- the arm 12d further extends upwardly in a space between the see-saw plate 6 and the bar 4e and yet further extends above and across the bar 4e towards a terminal leg 12e for the external connection.
- the portions 10d and 12d of the contact members 10 and 12 pass through said space between the see-saw plate 6 and the bar 4e in such a manner that, when the contact points 10c and 12c contact, the currents in said portions 10d and 12d direct simultaneously in the same direction.
- the switch assembly described above is particularly designed for use in switching a high power load actuated by an a.c. power source.
- Fig. 2 shows a load and an a.c. power source externally connected in series between the terminal legs 10e and 12e.
- FIG. 4 A waveform of a.c. power is shown in Fig. 4.
- a magnetic flux appears in the closed magnetic loop proportionally to the current flowing through the contact members 10 and 12.
- a waveform of the current flowing through the contact members 10 and 12 is shown in F ig. 4.
- an attractive force F2 appears between the see-saw plate 6 and the yoke 4, particularly the bars 4b and 4c.
- the magnetic force F2 will be maximum at the peaks of the a.c. current and will be zero at the zero crossing point of the a. c. current.
- a waveform of the magnetic force F2 is shown in Fig. 4.
- This magnetic force F2 aids the above mentioned magnetic force Fl, thus, the contact pressure between the contact points 10c and 12c is further reinforced.
- the contact pressure is effected by the sum of the forces Fl and F2.
- a waveform of the forces Fl and F2 added with each other is shown in Fig. 4.
- This reinforcement has such an advantage that the contact pressure required between the contact points 10c and 12c is obtained by the sum of the forces Fl and F2, and accordingly, the force Fl can be presented less than that needed to produce the required contact pressure, resulting in compact size of the coil 8.
- the switch 14 is turned off at a moment t3. Accordingly, the magnetic force Fl disappears at the moment t3, and only the magnetic force F2 is present thereafter. If, at the moment t3, a.c. current from the a.c. power is relatively high either in positive or negative region, the magnetic force F2 is also relatively high, thus maintaining the see-saw plate 6 in contact with the bars 4b and 4c of the yoke 4, that is,maintaining the contact points 10c and 12c in contact with each other. Then, within the half cycle of the a.c. current, the current level becomes as small as zero level, and accordingly, the magnetic force F2 also becomes zero.
- the switch assembly according to the present invention breaks the contact approximately at the zero crossing point of the a.c. current,no arc is produced, and accordingly, 'various disadvantages caused by the arc producing can be avoided, For example, the increase of temperature, generation of poisonous gas, and dissolution of contact points can be avoided.
- contact points 10c and 12c may abrade for some degree after numbers of operations, this results merely in the reduction of narrow gap produced between the see-saw plate 6 and the bar 4a of the yoke 4 when the switch assembly is in the operative position.
- the coil 8 defining an electromagnet together with the bars 4a and 4d for producing the force Fl may be replaced with any other means for actuating the see-saw plate 6, such as a push button or a device using piezoelectric effect as employed in the embodiments described later.
- the switch assembly of the second embodiment comprises a base 16 on which an electromagnet 18 is rigidly mounted.
- the electromagnet 18 includes a core 18a, a coil 18b and a frame 18c.
- Operatively provided to the electromagnet 18 is an "L" shaped lever 20 made of iron and pivotally supported at 20a.
- the lever 20 has one end portion provided with an electrically insulating material 20b and the other end portion located in a position capable of being affected by the magnetic force Fl of the electromagnet 18.
- a leaf spring 23 is mounted on the base 16 for pushing the corner of the "L" shaped lever 20.
- the lever 20 is normally rotated clockwise by the leaf spring 23 and is held in a position as shown in Fig. 5.
- the switch assembly of the second embodiment further comprises a first contact member 22 made of rigid conductive material, such as iron, and fixedly mounted on the base 16.
- the first contact member 22 has a contact point 22a rigidly mounted at its one end remote from the base 16.
- a first magnetic member 24 made of magnetic material and having a "U" shape cross section, as best shown in Figs. 6 and 7, is rigidly attached to an intermediate portion of the first contact member 22 through a suitable insulator, such as epoxy synthetic resin.
- the second contact member 26 has a contact point 26a rigidly mounted at its one end remote from the base 16 in such a manner that the contact point 26a faces the contact point 22a.
- the contact points 22a and 26a are spaced apart from each other, as shown in Fig. 5.
- a second magnetic member 28 made of magnetic material is attached to an intermediate portion of the second contact member 26, preferably through an insulator.
- first and second magnetic members 24 and 28 are so arranged that, when the second contact member 26 is pushed towards the first contact member 22 against the resiliency of the second contact member 26 to make contact between contact points 22a and 26a, the first and second magnetic members ' 24 and 28 contact with each other to define a tubular member in which the first contact member 22 passes through.
- the base 16 is further mounted with terminal legs 30a, 30b, 32a and 32b, in which the terminal legs 30a and 30b are connected to the coil 18b of the electromagnet 18, and the terminal legs 32a and 32b are connected, respectively, to the first and second contact members 22 and 26.
- terminal legs 30a and 30b are provided for the connection with switch and d.c. or a.c. source in series
- the terminal legs 32a and 32b are provided for the connection with a load and a.c. source of high power.
- the magnetic flux ⁇ gives rise to attractive force F2 between the magnetic members 24 and 28 in such a manner as to aid the contact pressure between the contact points 22a and 26a. Accordingly, the contact pressure exerting on the contact member 26 is effected by the sum of forces Fl and F2.
- the electromagnet 18 is deenergized by the opening of the switch, and accordingly, the force Fl disappears, and thereafter, the second contact member 26 is biased only by the force F2,
- the force F2 is reduced to about zero (moment t4), i.e., when the a.c. current reaches closed to the zero crossing point, the second contact member 26 separates away from the first contact member 22 by the force of leaf spring 22 and the resiliency of the contact member 26. Since a.c. current flow through the contact members 22 and 26 at the moment t4 is very low, no arc will be produced during the separation of the contact points 22a and 26a.
- FIG. 8 there is shown a modification of the switch assembly of the second embodiment.
- the modification shown employs a push button which is diagrammatically depicted by an arrow 34.
- the contact member 26' shown is a snap action type capable of producing a predetermined contact pressure when the push button 34 is depressed.
- the switch assembly according to the third embodiment is a double make-and-break switch and it comprises an "L" shaped wall defined by an upright wall 36 and base wall 38 which are connected in right angle to each other.
- a "U” shaped magnetic member 40 is fixedly mounted on the upright wall 36 such that the opposite side faces or walls of the "U” shaped magnetic member 40 extend away from the upright wall 36 and a groove defined in the "U” shaped magnetic member 40 extends parallelly to the corner between the upright and base walls 36 and 38.
- a first contact member 42 having contact points 42a and 42b at its opposite ends, respectively, is fixedly connected to the "U" shaped magnetic member 40 through a suitable insulator such that the elongated first contact member 42 extends through the groove of the "U” shaped magnetic member 40.
- a pair of second contact members 44 and 46 made of resilient conductive material are rigidly mounted on the base plate 38.
- the second contact members 44 and 46 have at their respective free ends contact points 44a and 46a which are in face-to-face relation with the contact points 42a and 42b, respectively, of the first contact member 42. It is to be noted that the contact points 44a and 46a are normally held away from the contact points 42a and 42b, respectively.
- the base wall 38 is formed with an elongated recess 38a which is located between the second contact members 44 and 46 and extends parallelly to the corner between the upright and base walls 36 and 38.
- the elongated recess 38a is provided for pivotally receiving a plate 48 made of magnetic material.
- the plate 48 is so long that its free end remote from the base wall 38 can contact the free end of the "U" shaped magnetic member 40.
- a card, or bar, 50 has its intermediate portion connected or rigidly secured to the plate 48 with its opposite end portions aligned respectively with the contact members 44 and 46 on one side thereof opposite to the side provided with the contact points 44a and 46a such that, when the external pushing force Fl indicated by an arrow is applied to the plate 48 through a suitable member 52 (Fig. 10) against the force of a spring 54, the plate 48 pivots about the elongated recess 38a towards the "U" shaped magnetic member 40, and by the bar 50, the contact members 44 and 46 can be pushed towards the first contact member 42.
- the resultant is such that the contact points 44a and 46a make contact with contact points 42a and 42b, respectively, and at the same time, the plate 48 contacts the "U" shaped magnetic member 40, as best shown in Fig. 11. Accordingly, when the contact is made, a closed magnetic loop is formed between the "U" shaped magnetic member 40 and the plate 48.
- the member 52 connected to the plate 48 is provided operatively in association with a suitable actuating means, such as a push button, electromagnet or the like for applying the pushing force Fl to the plate 48.
- a suitable actuating means such as a push button, electromagnet or the like for applying the pushing force Fl to the plate 48.
- the contact members 44 and 46 are electrically connected with a load and an a.c. power source in series.
- the operation of the switch assembly of the third embodiment is as follows.
- the switch assembly according to the third embodiment of the present invention is a double make-and-break switch, the sum of gaps between contact points 44a and 42a and between contact points 46a and 42b would be the required contact gap, and therefore, the stroke length of the contact members 44 and 46 can be shortened, resulting in compact size of the switch assembly.
- first contact member 42 can be connected to the "U" shaped magnetic member 40 through a suitable biasing means, such as a spring 56 as shown in Fig. 12, for increasing the contact pressure between the contact points 44a and 42a and between contact points 46a and 42b.
- a suitable biasing means such as a spring 56 as shown in Fig. 12, for increasing the contact pressure between the contact points 44a and 42a and between contact points 46a and 42b.
- FIG. 13 there is shown a modification of the switch assembly of the third embodiment.
- the switch assembly shown employs an electromagnet 58 as the actuating means for applying the biasing force Fl to the plate 48.
- the electromagnet 58 includes a coil 58a and a core 58b formed in a shape of "U". Instead of being pivotally supported in the elongated recess 38a, the lower end of the plate 48 is hinged to the edge of the core 58b.
- FIG. 14 there is shown another modification of the switch assembly of the third embodiment.
- the first contact member 42' is rigidly secured to the plate 48. Accordingly, the first contact member 42 is placed inside the groove of the "U" shaped magnetic member 40 only when the contacts are made.
- the switch assembly shown is a double make-and-break switch and it includes an air tight casing 60 made of, e.g., glass or synthetic resin, and a base 62 made of electrically non-conductive material, such as synthetic resin.
- the base 62 is secured inside and at the bottom portion of the casing 60.
- the base 62 has an upright wall 62a standing approximately at the center of the base 62 and a projection 62b extending from the upright wall 62a.
- the base 62 further has a hook 62c formed, when viewed in Fig. 15, at right-hand side thereof.
- a first magnetic member 64 made of magnetic material and having a "U" shaped configuration defined by upper and lower arm portions is fixedly mounted on the base 62 with the upper and lower arm portions directing towards the upright wall 62a.
- a second magnetic member 66 having a recess 66a formed in its one end portion is positioned operatively in association with the first magnetic member 64 such that the recess 66a loosely engages with the projection 62b.
- the second magnetic member 66 may pivot about the projection 62b between a first pivoted position in which the second magnetic member 66 separates away from the first magnetic member 64, particularly from the upper arm portion of the magnetic member 64, as shown in Fig. 15, and a second pivoted position in which the second magnetic member 66'abuts against the first magnetic member 64 to define a closed magnetic loop.
- a pair of first contact members 68 and 70 are fixedly mounted on the base 62 adjacent and on opposite sides, respectively, of the base 62. As best shown in Fig. 16, the contact member 68 extends through the groove of the "U” shaped magnetic member 64 and appears on the other side of the "U” shaped magnetic member 64. Similarly, the other contact member 70 passes through the groove of the "U” shaped magnetic member 64. In other words, the contact members 68 and 70 intersect with each other in the groove of the "U” shaped magnetic member 64.
- an insulation plate 71 is positioned between the contact members 68 and 70. At the ends of the contact members 68 and 70 remote from the base 62, contact points 68a and 70a are fixedly mounted.
- a second contact member 72 is rigidly secured to the second magnetic member 66 with opposite end portions aligned respectively with the contact points 68a and 70a. Accordingly, a pair of contact points 72a and 72b fixedly mounted at opposite end portions of the second contact member 72 align in face-to-face relation with contact points 68a and 70a, respectively.
- An electret 74 deposited with a first electrode 76 is fixedly attached to the upright wall 62a on a side opposite to the side provided with the projection 62b with said first electrode 76 being on a side touching the upright wall 62a.
- a second electrode 78 made of rigid but thin film plate, such as an aluminum plate, is operatively provided in association with the electret 74 in such a manner that the lower end of the second electrode 78 is pivotally engaged to the hook 62c of the base 62 and its upper end is linked with the second magnetic member 66 through a suitable arm 80 made of non-magnetic and non-conductive material.
- a biasing means, such as a leaf spring 82 is connected to the second electrode 78 for urging the second electrode 78 away from the electret 74.
- the switch assembly of the fourth embodiment further includes terminal legs 84a, 84b, 86a and 86b in which the terminal legs 84a and 84b are connected to the first and second electrodes 76 and 78, respectively, and the terminal legs 86a and 86b to the contact members 68 and 70, respectively.
- the terminal legs 84a and 84b are externally connected with a switch and a d.c. or a.c. source in series and the terminal legs 86a and 86b are externally connected with a load and an a.c, power source in series, in a similar manner to that shown in Fig. 2.
- the terminal legs 84a and 84b may be further connected with a discharging resistance 88, as shown in Fig. 18.
- the casing 60 is made vacuum or is filled with inactive gas, such as SF 6 (sulfur hexafluoride).
- inactive gas such as SF 6 (sulfur hexafluoride).
- the second electrode 78 When the switch is closed to supply d.c. voltage between the terminal legs 84a and 84b, the second electrode 78 receives attractive force Fl (Fig. 18) towards the electret 74 by the electrostatic charge appearing on the electret 74. Accordingly, the second electrode 78 pivots leftwardly about the hook 62c, and thus, it pushes the second magnetic member 66 leftwardly towards the second pivoted position mentioned above.
- the second magnetic member 66 When the second magnetic member 66 is turned to the second pivoted position, it not only contacts with the first magnetic member 64 to define a closed magnetic loop but also makes a contact between contact points 68a and 72a and between contact points 70a and 72b. Accordingly, a.c. current flows through the contact members 68, 72 and 70 to supply a.c.
- the contact members 68 and 70 passes through the closed magnetic loop defined by the magnetic members 64 and 66, and since the direction of currents flowing through the contact members 68 and 70 at the closed magnetic loop is the same, such currents give rise to magnetic flux ⁇ through the closed magnetic loop. Accordingly, the first and second magnetic members 64 and 66 attract each other by a magnetic force F2, as indicated in Fig. 15.
- the electret 74 and its associated parts serve as an actuating means for actuating the contact members.
- the contact members 68 and 70 both of which have been described as passing through the groove of the "U" shaped magnetic member 64, may be so arranged as to render only one contact member 68 or 70 pass through said groove. Furthermore, at least one of the contact members 68 and 70 may be so arranged as to pass through the groove for a number of times. This can be accomplished by winding the contact member for a number of times on the "U" shaped magnetic member 64,
- the swtich assembly according to the fourth embodiment of the present invention has an air tight casing for keeping the contact members in a vacuum or in inactive gas, the insulation between contact points can be increased without widening the gap therebetween. Accordingly, the stroke length of the contact member 72 can be arranged very small. This is particularly suitbale for use in a combination with the electret which can provide only a small stroke to the pivotally associated electrode.
- the switch assembly according to the fourth embodiment can be prepared in a compact size and operated with less power.
- the switch assembly shown has a bimorph 90 which moves in a direction indicated by an arrow in Fig. 20 by the piezoelectric effect when d.c. voltage is applied thereto. Such a movement of the bimorph results in termination of the second magnetic member 60 to the second pivoted position.
- the modification shown operates in a similar mamner to the switch assembly of the fourth embodiment and has the same meritorious effect as described above,
- a switch assembly according to a fifth embodiment of the present invention.
- the switch assembly shown is a double make-and-break switch and it includes stationarily provided contact members 92 and 94 having contact points 92a and 94a, respectively, at their end portions.
- the contact point 92a projects upwardly from the contact member 92 and the contact point 94a projects downwardly from the contact members 94.
- Another contact member 96 is fixedly connected to an axle 98 which is rotatably supported and positioned approximately at the center between the contact points 92a and 94a.
- the contact member 96 is so long that its opposite ends provided with contact points 96a and 96b, respectively, align with the contact points 92a and 94a.
- the contact points 96a and 96b are mounted on the opposite faces of the contact member 96, the contact points 96a comes into face-to-face contact with the contact point 92a and the contact point 96b comes into face-to-face contact with the contact point 94a when the contact member 96 is rotated counterclockwise about the axle 98.
- the contact member 96 rigidly carries a "U" shaped magnetic member 100 at intermediate portion between the axle 98 and the contact point 96a such that the contact member 96 extends through the groove defined in the "U” shaped magnetic member 100 and the opposite parallel arms of the "U” shaped magnetic member 100 direct in the same direction as the projecting direction of the contact point 96a, as shown in Fig. 21.
- another "U” shaped magnetic member 102 is rigidly carried by the contact member 96 at intermediate portion between the axle 98 and the contact point 96b.
- the parallel arms of the "U” shaped magnetic member 102 direct in the same direction as the projecting direction of the contact point 96b.
- the mounting of the "U” shaped magnetic members 100 and 102 is effected by the injection of non-conductive and non-magnetic material, such as epoxy resin, in the groove of the "U" shaped magnetic members 100 and 102.
- a stationary magnetic member 104 having bifurcated arms 104a and 104b is provided in association with the "U" shaped magnetic members 100 and 102 such that when the contact plate 96 is rotated counterclockwise to make contacts between the contact points 92a and 96a and between contact points 94a and 96b, the "U" shaped magnetic member 100, particularly the free ends of the opposite parallel arms of the "U” shaped magnetic member 100, abuts against the arm 104a of the bifurcated arms and, at the same time, the "U” shaped magnetic member 102 similarly abuts agsint the arm 104b of the bifurcated arms. Accordingly, one closed magnetic loop is defined by the "U” shaped magnetic member 100 and the arm 104a, and another closed magnetic loop is defined by the "U" shaped magnetic member 102 and the arm 104b.
- the contact member 96 and "U" shaped magnetic members 100 and 102 carried by the member 96 are held in a position shown in Fig. 23 by a suitable biasing means, such as springs 106 and 108. In this position, no closed magnetic loop is formed and facing contact points are separated away from each other.
- the switch assembly according to the fifth embodiment further includes actuating means which exerts rotating force Fl on the contact member 96 or on at least one of "U" shaped magnetic members 100 and 102, as shown by arrows in Fig. 22, for actuating the contact member 96 to rotate couterclockwise about the axle 98 against the biasing force of the springs 106 and 108.
- actuating means which exerts rotating force Fl on the contact member 96 or on at least one of "U" shaped magnetic members 100 and 102, as shown by arrows in Fig. 22, for actuating the contact member 96 to rotate couterclockwise about the axle 98 against the biasing force of the springs 106 and 108.
- the switch assembly of the fifth embodiment is arranged symmetrically and well balanced about the axle 98, resistance against shock and vibration is improved.
- the switch assembly according to the present invention breaks the contact points approximately at the zero crossing point of the a.c. power without employing any electrical detecting means. Accordingly, switch assembly according to the present invention can break the contact points without producing any arc and yet can be assembled compact in size with a simple structure.
Abstract
Description
- The present invention relates to a switch assembly and, more particularly, to an improved switch assembly capable of being used for cutting and supplying high a.c. power.
- When a switch assembly having at least one pair of contacts transmits a high a.c. power, the current flowing through the switch assembly varies from positive maximum point through a zero crossing point to a negative maximum point and vice versa as in a sinusoidal waveform. When the switch assembly cuts, or breaks, the current at the zero crossing point, the contacts may separate away from each other without producing any arc. On the contrary, when the current is cut at a moment other than the zero crossing point, an arc may be produced between the contacts, and this possibility is high as the cutting is effected closer to the maximum point of the a.c. current. If the arc is once produced, it continues until the next zero crossing point comes.
- When the arc is produced, it results in various disadvantages, such as increase of temperature, generation of poisonous gas, and dissolution of contacts.
- In order to avoid the generation of arc, one may use a phase detector in combination with a switch assembly to effecting the cutting of the switch assembly in synchronized relation to the detection of zero crossing point by the phase detector.
- This arrangement, however, results in bulky in size and high manufacturing cost.
- Accordingly, it is a primary object of the present invention to provide an improved switch assembly which substantially breaks the contacts at the zero crossing point without employing any electrical phase detector.
- It is another object of the present invention to provide an improved switch assembly of the above described type which is simple in construction and can be readily manufactured at low cost.
- In accomplishing these and other objects, a switch assembly according to the present invention comprises first and second contact means provided operatively to take one of two positions, a break-position in which the first and second contact means are electrically separated from each other, and a make-position in which the first and second contact means are electrically connected with each other to define a current path therethrough, first and second magnetic bodies provdied operatively in association with said first and second contact means such that said first and second magnetic bodies define at least one closed magnetic loop with at least one of said first and second contact means passing through said closed magnetic loop when said first and second contact means are turned to said make-position, and said magnetic loop opens when said first and second contact means are turned to said break-position, biasing means for biasing said first and second contact means towards said break-position, and actuating means for actuating said first and second contact means towards said make-position against said biasing means.
- These and other objects and features of the present invention will become apparent from the following description taken in conjunction with preferred embodiments thereof with reference to the accompanying drawings, in which:
- Fig. 1 is a perspective view of a switch assembly according to a first embodiment of the present invention;
- Fig. 2 is a diagrammatic view of a switch assembly of Fig. 1 with a framework being removed;
- Fig. 3 is a cross-sectional view taken along a line III-III shown in Fig. 2;
- Fig. 4 is a graph showing operating condition of the switch assembly according to the present invention in timed relation;
- Fig. 5 is a side view of a switch assembly according to a second embodiment of the present invention;
- Fig. 6 is an exploded view partly showing first and second contact members and first and second magnetic members;
- Fig. 7 is a cross-sectional view taken along a line VII shown in Fig. 5;
- Fig. 8 is a diagrammatic view of a modification of the second embodiment;
- Fig. 9 is a perspective view showing major parts of a switch assembly according to a third embodiment of the present invention;
- Fig. 10 is a side view of the switch assembly shown in Fig. 9;
- Fig. 11 is a diagrammatic view showing a closed magnetic loop defined in the switch assembly of Fig. 9;
- Fig. 12 is a diagrammatic view of a modification of the third embodiment and particularly showing a modified portion;
- Fig. 13 is a diagrammatic view of another modification of the third embodiment;
- Fig. 14 is a diagrammatic view of a further modification of the third embodiment and particularly showing a modified portion;
- Fig. 15 is a side view of a switch assembly according to the fourth embodiment of the present invention;
- Fig. 16 is a perspective view particularly showing relationship among first and second contact members and first and second magnetic members of the switch assembly of Fig. 15;
- . Fig. 17 is a top view of a switch assembly of Fig. 15;
- Fig. 18 is a diagrammatic view of an electret employed in the switch assembly of Fig. 15;
- Fig. 19 is a view similar to Fig. 15, but particularly showing a modification thereof;
- Fig. 20 is a diagrammatic view of a bimorph employed in the switch assembly of Fig. 19;
- Fig. 21 is a perspective view of a major portion of a switch assembly according to a fifth embodiment of the present invention; and
- Figs. 22 and 23 are diagrammatic views showing different operated positions of the switch assembly of Fig. 21.
- Referring to Fig. 1, there is shown a switch assembly of a first embodiment according to the present invention. The switch assembly of the first embodiment comprises a
framework 2 made of electrically non-conductive material, such as synthetic resin, ayoke 4 made of magnetic material, such as iron, and rigidly supported by theframe 2, a see-saw plate 6 made of magnetic material, such as iron, and rotatably supported by theframe 2, acoil 8 mounted on theyoke 4, and first andsecond contact members yoke 4 and see-saw plate 6. The structure of the switch assembly of the first embodiment is described in detail below with reference to Fig. 2 schematically showing the switch assembly without theframework 2 and Fig. 3 showing a cross-sectional view taken along a line III-III shown in Fig. 2. - The
yoke 4, as best shown in Fig. 2, has an "S" shape configuration defined by threehorizontal bars vertical bars bars bar 4a extends above said plane. - The
coil 8 is mounted on thebar 4d of theyoke 4 and is electrically connected to aswitch 14 and apower source 16 in series. Thepower source 16 shown in Fig. 2 is a d.c. power source, such as a battery, but it can be an a.c. power source. Thecoil 8 is provided for magnetizing particularly thebars yoke 4 when theswitch 14 is closed. - The see-
saw plate 6 is so long that its one end locates under thebar 4a and the other end locates above thebar 4c of theyoke 4. A pair ofpins saw plate 6 for the engagement with corresponding recesses or openings (not shown) formed in theframework 2 so that the see-saw plate 6 may rotate about thepins saw plate 6 is restricted by theframework 2 to terminate in a position shown in Fig. 3. On the other hand, the counterclockwise rotation of the see-saw plate 6 is restricted by thecontact members - The
first contact member 10 has a "T" shaped portion, as shown in Fig. 1, defined byarms 10a and 10b such that the arm 10b extends perpendicularly from the center of thearm 10a. The opposite ends of thearm 10a of thecontact member 10 are rigidly supported by theframework 2 and the arm 10b extends over the see-saw plate 6. The arm lOb, serving as a leaf spring, is slightly bent downwardly with respect to thearm 10a so that the end of the arm 10b remote from thearm 10a contacts and pushes the see-saw plate 6 to the position shown in Fig. 3. Acontact point 10c is mounted on the end portion of the arm lOb, as best shown in Fig. 3. Since there is noframework 2 shown in Figs. 2 and 3, thearm 10a of thecontact member 10 is not apparently shown in these Figs. 2 and 3. - The first contact member further includes an
arm 10d connected to thearm 10a and extends in a space between the see-saw plate 6 andbar 4e of theyoke 4 and further extends in the direction away from thebar 4e under the see-saw plate 6, and terminates to aterminal leg 10e for the external connection. - The
second contact member 12 has an "L" shaped portion, as shown in Figs. 1 and 2, defined byarms contact point 12c is mounted on the end portion of thearm 12a in face-to-face relation with thecontact point 10c. Since thearms frame 2, thearm 12a stops the rotation of see-saw plate 6 upon contact of thecontact points arms - The
contact member 12 further includes anarm 12d connected to thearm 12b and extends, as best shown in Fig. 2, towards thebar 4e of theyoke 4 under the see-saw plate 6. Thearm 12d further extends upwardly in a space between the see-saw plate 6 and thebar 4e and yet further extends above and across thebar 4e towards aterminal leg 12e for the external connection. - It is to be noted that the
portions contact members saw plate 6 and thebar 4e in such a manner that, when thecontact points portions - It is to be noted that, when the switch assembly described above is in an inoperative position as shown in Fig. 3, a gap Gl between
contact points saw plate 6 andbar 4a of theyoke 4. Thus, when the above described switch assembly of the first embodiment is turned. to an operative position to establish a contact between the contact points 10c and 12c, the see-saw plate 6 and thebar 4a of theyoke 4 are maintained apart from each other, e.g., by 0.2 to 0.3 mm. - The switch assembly described above is particularly designed for use in switching a high power load actuated by an a.c. power source. Fig. 2 shows a load and an a.c. power source externally connected in series between the
terminal legs - Next, the operation of the switch assembly of the first embodiment is described with reference to a time chart shown in Fig. 4.
- When the
switch 14 is turned on at a moment tl, thecoil 8 is excited to magnetize theyoke 4, particularly thebar 4a. Thus, a magnetic force Fl (Fig. 3) appears in thebar 4a attracting the see-saw plate 6. Therefore, the see-saw plate 6, which has been in the position shown in Fig. 3, starts to turn counterclockwise until the contact points 10c and 12c contact with each other, i.e., at a moment t2. Even after the contact points 10c and 12c contact, a narrow gap is present between the see-saw plate 6 and thebar 4a of theyoke 4 with the attractive force Fl exerting on the see-saw plate 6. Thus, a predetermined contact pressure between the contact points 10c and 12c can be obtained by the attractive force Fl. - The counterclockwise rotation of the see-
saw plate 6 not only results in contact between the contact points 10c and 12c, but also in contact between see-saw plate 6 and each ofbars yoke 4, establishing a closed magnetic loop through thebars saw plate 6. - Thus, when the see-
saw plate 6 is rotated counterclockwise to make contact between the contact points 10c and 12c and to establish the closed magnetic loop at the moment t2, a.c. current flows through thecontact members - (A waveform of a.c. power is shown in Fig. 4.) Since the
portions contact members contact members contact members saw plate 6 and theyoke 4, particularly thebars - This reinforcement has such an advantage that the contact pressure required between the contact points 10c and 12c is obtained by the sum of the forces Fl and F2, and accordingly, the force Fl can be presented less than that needed to produce the required contact pressure, resulting in compact size of the
coil 8. - Thereafter, when it is required to break the
contacts switch 14 is turned off at a moment t3. Accordingly, the magnetic force Fl disappears at the moment t3, and only the magnetic force F2 is present thereafter. If, at the moment t3, a.c. current from the a.c. power is relatively high either in positive or negative region, the magnetic force F2 is also relatively high, thus maintaining the see-saw plate 6 in contact with thebars yoke 4, that is,maintaining the contact points 10c and 12c in contact with each other. Then, within the half cycle of the a.c. current, the current level becomes as small as zero level, and accordingly, the magnetic force F2 also becomes zero. During this half cycle, the biasing force of the leaf spring or arm 10b urging the see-saw plate 6 clockwise exceeds the force F2 for effecting the clockwise rotation of the see-saw plate 6 towards inoperative position, and thus substantially breaking thecontacts contacts contacts contacts contact 10c and its associated parts that move together with thecontact 10c further delays the separation, reaching closer to the zero crossing point of the a.c. current. - Since the switch assembly according to the present invention breaks the contact approximately at the zero crossing point of the a.c. current,no arc is produced, and accordingly, 'various disadvantages caused by the arc producing can be avoided, For example, the increase of temperature, generation of poisonous gas, and dissolution of contact points can be avoided.
- Although the contact points 10c and 12c may abrade for some degree after numbers of operations, this results merely in the reduction of narrow gap produced between the see-
saw plate 6 and thebar 4a of theyoke 4 when the switch assembly is in the operative position. - It is to be noted that the
coil 8 defining an electromagnet together with thebars saw plate 6, such as a push button or a device using piezoelectric effect as employed in the embodiments described later. - Referring to Fig. 5, there is shown a switch assembly according to a second embodiment of the present invention. The switch assembly of the second embodiment comprises a base 16 on which an
electromagnet 18 is rigidly mounted. Theelectromagnet 18 includes a core 18a, acoil 18b and aframe 18c. Operatively provided to theelectromagnet 18 is an "L" shapedlever 20 made of iron and pivotally supported at 20a. Thelever 20 has one end portion provided with an electrically insulatingmaterial 20b and the other end portion located in a position capable of being affected by the magnetic force Fl of theelectromagnet 18. A leaf spring 23 is mounted on thebase 16 for pushing the corner of the "L" shapedlever 20. Thus, thelever 20 is normally rotated clockwise by the leaf spring 23 and is held in a position as shown in Fig. 5. - The switch assembly of the second embodiment further comprises a
first contact member 22 made of rigid conductive material, such as iron, and fixedly mounted on thebase 16. Thefirst contact member 22 has acontact point 22a rigidly mounted at its one end remote from thebase 16. A firstmagnetic member 24 made of magnetic material and having a "U" shape cross section, as best shown in Figs. 6 and 7, is rigidly attached to an intermediate portion of thefirst contact member 22 through a suitable insulator, such as epoxy synthetic resin. - A
second contact member 26 made of resilient conductive material, such as a thin iron plate, is fixedly mounted on the base 16 at a position between thefirst contact member 22 and thelever 20. Thesecond contact member 26 has acontact point 26a rigidly mounted at its one end remote from the base 16 in such a manner that thecontact point 26a faces thecontact point 22a. Normally, thecontact points magnetic member 28 made of magnetic material is attached to an intermediate portion of thesecond contact member 26, preferably through an insulator. - It is to be noted that the first and second
magnetic members second contact member 26 is pushed towards thefirst contact member 22 against the resiliency of thesecond contact member 26 to make contact betweencontact points magnetic members first contact member 22 passes through. - The
base 16 is further mounted withterminal legs coil 18b of theelectromagnet 18, and theterminal legs second contact members terminal legs - Next, the operation of the switch assembly of the second embodiment is described with reference to Fig. 4.
- When the switch is turned on at the moment tl to excite the
electromagnet 18, the "L" shapedlever 20 is turned counterclockwise against the force of leaf spring 23 and resiliency of thecontact member 26 by the magnetic force Fl exerting on thelever 20. Thus, at the moment t2, thecontact points magnetic members contact members contact member 22, a magnetic flux φ appears in a closed magnetic loop defined in the tube, as shown in Fig. 7. The magnetic flux φ gives rise to attractive force F2 between themagnetic members contact points contact member 26 is effected by the sum of forces Fl and F2. - Then, at the moment t3, the
electromagnet 18 is deenergized by the opening of the switch, and accordingly, the force Fl disappears, and thereafter, thesecond contact member 26 is biased only by the force F2, When the force F2 is reduced to about zero (moment t4), i.e., when the a.c. current reaches closed to the zero crossing point, thesecond contact member 26 separates away from thefirst contact member 22 by the force ofleaf spring 22 and the resiliency of thecontact member 26. Since a.c. current flow through thecontact members contact points - Referring to Fig. 8, there is shown a modification of the switch assembly of the second embodiment. Instead of the electromagnet, the modification shown employs a push button which is diagrammatically depicted by an
arrow 34. Furthermore, the contact member 26' shown is a snap action type capable of producing a predetermined contact pressure when thepush button 34 is depressed. - Referring to Fig. 9, there is shown a switch assembly according to the third embodiment of the present invention. The switch assembly according to the third embodiment is a double make-and-break switch and it comprises an "L" shaped wall defined by an
upright wall 36 andbase wall 38 which are connected in right angle to each other. A "U" shapedmagnetic member 40 is fixedly mounted on theupright wall 36 such that the opposite side faces or walls of the "U" shapedmagnetic member 40 extend away from theupright wall 36 and a groove defined in the "U" shapedmagnetic member 40 extends parallelly to the corner between the upright andbase walls first contact member 42 havingcontact points magnetic member 40 through a suitable insulator such that the elongatedfirst contact member 42 extends through the groove of the "U" shapedmagnetic member 40. A pair ofsecond contact members base plate 38. Thesecond contact members ends contact points contact points first contact member 42. It is to be noted that thecontact points contact points base wall 38 is formed with anelongated recess 38a which is located between thesecond contact members base walls elongated recess 38a is provided for pivotally receiving aplate 48 made of magnetic material. Theplate 48 is so long that its free end remote from thebase wall 38 can contact the free end of the "U" shapedmagnetic member 40. - A card, or bar, 50 has its intermediate portion connected or rigidly secured to the
plate 48 with its opposite end portions aligned respectively with thecontact members contact points plate 48 through a suitable member 52 (Fig. 10) against the force of aspring 54, theplate 48 pivots about theelongated recess 38a towards the "U" shapedmagnetic member 40, and by thebar 50, thecontact members first contact member 42. The resultant is such that thecontact points contact points plate 48 contacts the "U" shapedmagnetic member 40, as best shown in Fig. 11. Accordingly, when the contact is made, a closed magnetic loop is formed between the "U" shapedmagnetic member 40 and theplate 48. - It is to be noted that the
member 52 connected to theplate 48 is provided operatively in association with a suitable actuating means, such as a push button, electromagnet or the like for applying the pushing force Fl to theplate 48. - As diagrammatically shown in Fig. 9, the
contact members - The operation of the switch assembly of the third embodiment is as follows.
- When the
plate 48 is pushed by the force Fl, thecontact points contact points contact members magnetic member 40 and theplate 48, as shown in Fig. ll. Accordingly, themember 40 and theplate 48 are attracted with each other by a magnetic force F2, as shown in Fig. 11. - Then, when the biasing force Fl is removed, e.g., by stopping the depression of a push button (not shown), only the magnetic force F2 is present. This magnetic force F2 decreases to zero within a half cycle of a.c. power, and accordingly, the contact points break in a similar manner described above, without producing any arc.
- Since the switch assembly according to the third embodiment of the present invention is a double make-and-break switch, the sum of gaps between
contact points contact points contact members - It is to be noted that the
first contact member 42 can be connected to the "U" shapedmagnetic member 40 through a suitable biasing means, such as aspring 56 as shown in Fig. 12, for increasing the contact pressure between thecontact points contact points - Referring to Fig. 13, there is shown a modification of the switch assembly of the third embodiment. The switch assembly shown employs an
electromagnet 58 as the actuating means for applying the biasing force Fl to theplate 48. Theelectromagnet 58 includes acoil 58a and a core 58b formed in a shape of "U". Instead of being pivotally supported in theelongated recess 38a, the lower end of theplate 48 is hinged to the edge of the core 58b. - Referring to Fig. 14, there is shown another modification of the switch assembly of the third embodiment. According to the switch assembly shown, the first contact member 42' is rigidly secured to the
plate 48. Accordingly, thefirst contact member 42 is placed inside the groove of the "U" shapedmagnetic member 40 only when the contacts are made. - Referring to Fig. 15, there is shown a switch assembly according to a fourth embodiment of the present invention. The switch assembly shown is a double make-and-break switch and it includes an air
tight casing 60 made of, e.g., glass or synthetic resin, and a base 62 made of electrically non-conductive material, such as synthetic resin. Thebase 62 is secured inside and at the bottom portion of thecasing 60. Thebase 62 has anupright wall 62a standing approximately at the center of thebase 62 and aprojection 62b extending from theupright wall 62a. The base 62 further has ahook 62c formed, when viewed in Fig. 15, at right-hand side thereof. - A first
magnetic member 64 made of magnetic material and having a "U" shaped configuration defined by upper and lower arm portions is fixedly mounted on the base 62 with the upper and lower arm portions directing towards theupright wall 62a. A secondmagnetic member 66 having arecess 66a formed in its one end portion is positioned operatively in association with the firstmagnetic member 64 such that therecess 66a loosely engages with theprojection 62b. Thus, the secondmagnetic member 66 may pivot about theprojection 62b between a first pivoted position in which the secondmagnetic member 66 separates away from the firstmagnetic member 64, particularly from the upper arm portion of themagnetic member 64, as shown in Fig. 15, and a second pivoted position in which the second magnetic member 66'abuts against the firstmagnetic member 64 to define a closed magnetic loop. - A pair of
first contact members base 62. As best shown in Fig. 16, thecontact member 68 extends through the groove of the "U" shapedmagnetic member 64 and appears on the other side of the "U" shapedmagnetic member 64. Similarly, theother contact member 70 passes through the groove of the "U" shapedmagnetic member 64. In other words, thecontact members magnetic member 64. For preventing a contact between the contact members within the groove of the "U" shapedmagnetic member 64, aninsulation plate 71 is positioned between thecontact members contact members base 62,contact points 68a and 70a are fixedly mounted. - A
second contact member 72 is rigidly secured to the secondmagnetic member 66 with opposite end portions aligned respectively with thecontact points 68a and 70a. Accordingly, a pair ofcontact points second contact member 72 align in face-to-face relation withcontact points 68a and 70a, respectively. - An
electret 74 deposited with afirst electrode 76 is fixedly attached to theupright wall 62a on a side opposite to the side provided with theprojection 62b with saidfirst electrode 76 being on a side touching theupright wall 62a. Asecond electrode 78 made of rigid but thin film plate, such as an aluminum plate, is operatively provided in association with theelectret 74 in such a manner that the lower end of thesecond electrode 78 is pivotally engaged to thehook 62c of thebase 62 and its upper end is linked with the secondmagnetic member 66 through asuitable arm 80 made of non-magnetic and non-conductive material. A biasing means, such as aleaf spring 82 is connected to thesecond electrode 78 for urging thesecond electrode 78 away from theelectret 74. - The switch assembly of the fourth embodiment further includes
terminal legs terminal legs second electrodes terminal legs contact members terminal legs terminal legs terminal legs resistance 88, as shown in Fig. 18. - In order to reduce the possibility of producing any arc, the
casing 60 is made vacuum or is filled with inactive gas, such as SF6 (sulfur hexafluoride). - Next, the operation of the switch assembly according to the fourth embodiment is described.
- When the switch is closed to supply d.c. voltage between the
terminal legs second electrode 78 receives attractive force Fl (Fig. 18) towards theelectret 74 by the electrostatic charge appearing on theelectret 74. Accordingly, thesecond electrode 78 pivots leftwardly about thehook 62c, and thus, it pushes the secondmagnetic member 66 leftwardly towards the second pivoted position mentioned above. When the secondmagnetic member 66 is turned to the second pivoted position, it not only contacts with the firstmagnetic member 64 to define a closed magnetic loop but also makes a contact betweencontact points contact points 70a and 72b. Accordingly, a.c. current flows through thecontact members contact members magnetic members contact members magnetic members - Then, when the biasing force Fl is removed by turning the switch off, only the magnetic force F2 is present. This magnetic force F2 decreases to zero within a half cycle of a.c. power, and accordingly, the contact points break in a similar manner described above without producing any arc.
- As will be understood to those skilled in the art, the
electret 74 and its associated parts serve as an actuating means for actuating the contact members. - It is to be noted that the
contact members magnetic member 64, may be so arranged as to render only onecontact member contact members magnetic member 64, - Since the swtich assembly according to the fourth embodiment of the present invention has an air tight casing for keeping the contact members in a vacuum or in inactive gas, the insulation between contact points can be increased without widening the gap therebetween. Accordingly, the stroke length of the
contact member 72 can be arranged very small. This is particularly suitbale for use in a combination with the electret which can provide only a small stroke to the pivotally associated electrode. - Since the electret is small in size and consumes relatively low power, and since the stroke of the movable contact member is relatively short, the switch assembly according to the fourth embodiment can be prepared in a compact size and operated with less power.
- Referring to Figs. 19 and 20, there is shown a modification of the switch assembly of the fourth embodiment, Instead of the electret, the switch assembly shown has a
bimorph 90 which moves in a direction indicated by an arrow in Fig. 20 by the piezoelectric effect when d.c. voltage is applied thereto. Such a movement of the bimorph results in termination of the secondmagnetic member 60 to the second pivoted position. Thus, the modification shown operates in a similar mamner to the switch assembly of the fourth embodiment and has the same meritorious effect as described above, - Referring to Fig. 21, there is shown a switch assembly according to a fifth embodiment of the present invention. The switch assembly shown is a double make-and-break switch and it includes stationarily provided
contact members contact points contact point 92a projects upwardly from thecontact member 92 and thecontact point 94a projects downwardly from thecontact members 94. Anothercontact member 96 is fixedly connected to anaxle 98 which is rotatably supported and positioned approximately at the center between thecontact points contact member 96 is so long that its opposite ends provided withcontact points contact points contact points contact member 96, thecontact points 96a comes into face-to-face contact with thecontact point 92a and thecontact point 96b comes into face-to-face contact with thecontact point 94a when thecontact member 96 is rotated counterclockwise about theaxle 98. - The
contact member 96 rigidly carries a "U" shapedmagnetic member 100 at intermediate portion between theaxle 98 and thecontact point 96a such that thecontact member 96 extends through the groove defined in the "U" shapedmagnetic member 100 and the opposite parallel arms of the "U" shapedmagnetic member 100 direct in the same direction as the projecting direction of thecontact point 96a, as shown in Fig. 21. - Similarly, another "U" shaped
magnetic member 102 is rigidly carried by thecontact member 96 at intermediate portion between theaxle 98 and thecontact point 96b. In this case, the parallel arms of the "U" shapedmagnetic member 102 direct in the same direction as the projecting direction of thecontact point 96b. The mounting of the "U" shapedmagnetic members magnetic members - A stationary
magnetic member 104 having bifurcatedarms magnetic members contact plate 96 is rotated counterclockwise to make contacts between thecontact points contact points magnetic member 100, particularly the free ends of the opposite parallel arms of the "U" shapedmagnetic member 100, abuts against thearm 104a of the bifurcated arms and, at the same time, the "U" shapedmagnetic member 102 similarly abuts agsint thearm 104b of the bifurcated arms. Accordingly, one closed magnetic loop is defined by the "U" shapedmagnetic member 100 and thearm 104a, and another closed magnetic loop is defined by the "U" shapedmagnetic member 102 and thearm 104b. - Normally, the
contact member 96 and "U" shapedmagnetic members member 96 are held in a position shown in Fig. 23 by a suitable biasing means, such assprings - The switch assembly according to the fifth embodiment further includes actuating means which exerts rotating force Fl on the
contact member 96 or on at least one of "U" shapedmagnetic members contact member 96 to rotate couterclockwise about theaxle 98 against the biasing force of thesprings - Next, the operation of the switch assembly according to the fifth embodiment of the present invention is described.
- When the biasing force Fl pushes the
contact member 96, thecontact member 96 carrying the "U" shapedmagnetic members contact members magnetic member 100 andarm 104a and also that defined by the "U" shapedmagnetic member 102 andarm 104b. Thus, the "U" shapedmagnetic member 100 andarm 104a are attracted with each other, and the "U" shapedmagnetic member 102 andarm 104b are attracted with each other to aid the biasing force Fl. - Then, when the biasing force Fl is removed, only the above mentioned attractive forces are present. These attractive forces decrease to zero within a half cycle of a.c. power, and accordingly, the contact points break in a similar manner described above without producing any arc to terminate the
contact member 96 in the position shown in Fig. 23. - Since the switch assembly of the fifth embodiment is arranged symmetrically and well balanced about the
axle 98, resistance against shock and vibration is improved. - As has been described in connection with several preferred embodiments, the switch assembly according to the present invention breaks the contact points approximately at the zero crossing point of the a.c. power without employing any electrical detecting means. Accordingly, switch assembly according to the present invention can break the contact points without producing any arc and yet can be assembled compact in size with a simple structure.
- Although the present invention has been fully described with reference to several preferred embodiments, many modifications and variations thereof will now be apparent to those skilled in the art, and the scope of the present invention is therefore to be limited not by the details of the preferred embodiments described above, but only by the terms of the appended claims.
Claims (33)
Applications Claiming Priority (6)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5595/81 | 1981-01-16 | ||
JP56005595A JPS57119419A (en) | 1981-01-16 | 1981-01-16 | Switching device |
JP10990381A JPS5810321A (en) | 1981-07-13 | 1981-07-13 | Switching mechanism |
JP109903/81 | 1981-07-13 | ||
JP119941/81 | 1981-07-30 | ||
JP11994181A JPS5819835A (en) | 1981-07-30 | 1981-07-30 | Relay |
Publications (3)
Publication Number | Publication Date |
---|---|
EP0056624A2 true EP0056624A2 (en) | 1982-07-28 |
EP0056624A3 EP0056624A3 (en) | 1983-04-06 |
EP0056624B1 EP0056624B1 (en) | 1985-05-02 |
Family
ID=27276821
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP82100243A Expired EP0056624B1 (en) | 1981-01-16 | 1982-01-14 | Switch assembly |
Country Status (2)
Country | Link |
---|---|
EP (1) | EP0056624B1 (en) |
DE (1) | DE3263323D1 (en) |
Cited By (4)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0185306A2 (en) * | 1984-12-21 | 1986-06-25 | General Electric Company | Advanced piezoceramic power switching devices employing protective gastight enclosure and method of manufacture |
EP0187300A2 (en) * | 1984-12-21 | 1986-07-16 | General Electric Company | Zero crossing synchronous AC switching circuits employing piezoceramic bender-type switching devices |
EP0189302A2 (en) * | 1985-01-21 | 1986-07-30 | Nec Corporation | Piezoelectric latching actuator having an impact receiving projectile |
US5596260A (en) * | 1994-05-13 | 1997-01-21 | Apple Computer, Inc. | Apparatus and method for determining a charge of a battery |
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DD112546A1 (en) * | 1974-07-03 | 1975-04-12 | ||
DE2615726A1 (en) * | 1976-04-10 | 1977-10-27 | Bbc Brown Boveri & Cie | Contact system for circuit breakers - has moving contact with switching force boosted by directly associated ferromagnetic member |
US4112279A (en) * | 1977-09-02 | 1978-09-05 | Bell Telephone Laboratories, Incorporated | Piezoelectric relay construction |
DE2814533A1 (en) * | 1977-04-05 | 1978-10-12 | Anvar | ELECTRIC RELAY |
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1982
- 1982-01-14 EP EP82100243A patent/EP0056624B1/en not_active Expired
- 1982-01-14 DE DE8282100243T patent/DE3263323D1/en not_active Expired
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DE1539061B1 (en) * | 1965-12-17 | 1970-10-08 | Elektromekhaniki Fil Vnii | Folding armature electromagnet system |
US3621174A (en) * | 1968-10-28 | 1971-11-16 | Gen Electric | Lubricative atmosphere for sealed switches |
DE7037475U (en) * | 1970-10-10 | 1971-05-06 | Bach & Co | Electrical relays, especially small relays |
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Non-Patent Citations (1)
Title |
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Soviet Inventions Illustrated Week C50 28, January 1981 Section X13 * |
Cited By (8)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0185306A2 (en) * | 1984-12-21 | 1986-06-25 | General Electric Company | Advanced piezoceramic power switching devices employing protective gastight enclosure and method of manufacture |
EP0187300A2 (en) * | 1984-12-21 | 1986-07-16 | General Electric Company | Zero crossing synchronous AC switching circuits employing piezoceramic bender-type switching devices |
JPS62154421A (en) * | 1984-12-21 | 1987-07-09 | ゼネラル・エレクトリツク・カンパニイ | Zero cross synchronizing ac switcing circuit using piezoelectric bending switching apparatus |
EP0185306A3 (en) * | 1984-12-21 | 1989-01-25 | General Electric Company | Advanced piezoceramic power switching devices employing protective gastight enclosure and method of manufacture |
EP0187300A3 (en) * | 1984-12-21 | 1989-02-08 | General Electric Company | Zero crossing synchronous ac switching circuits employing piezoceramic bender-type switching devices |
EP0189302A2 (en) * | 1985-01-21 | 1986-07-30 | Nec Corporation | Piezoelectric latching actuator having an impact receiving projectile |
EP0189302A3 (en) * | 1985-01-21 | 1989-03-08 | Nec Corporation | Piezoelectric latching actuator having an impact receiving projectile |
US5596260A (en) * | 1994-05-13 | 1997-01-21 | Apple Computer, Inc. | Apparatus and method for determining a charge of a battery |
Also Published As
Publication number | Publication date |
---|---|
EP0056624A3 (en) | 1983-04-06 |
DE3263323D1 (en) | 1985-06-05 |
EP0056624B1 (en) | 1985-05-02 |
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