US3582588A

US3582588A - Motion translating means

Info

Publication number: US3582588A
Application number: US830347A
Authority: US
Inventors: Charles Andre Cichocki; Edouard Mancini; Gustave Sutter
Original assignee: Societe dAppareillage Electrique Gardy SAS
Current assignee: Societe dAppareillage Electrique Gardy SAS
Priority date: 1968-06-13
Filing date: 1969-06-04
Publication date: 1971-06-01
Anticipated expiration: 1988-06-01
Also published as: FR1591354A; CH477081A

Abstract

The invention relates to actuating mechanism for moving switch contacts to thereby open and close a circuit in a vacuum envelope. The actuating mechanism includes an oscillatable lobe associated with pivotal lever means which when motivated cause the contacts in the vacuum envelope to open and close.

Description

United States Patent lnventors Charles Andre Cichockie Edouard Mancini; Gustave Sutter, all of Petit-Lancy, Switzerland [51] Int. Cl ..l-l01h 33/66 [50] Field of Search ZOO/144.2, 153.13,153.7

[56] References Cited UNITED STATES PATENTS 3,214,557 10/1965 Pflanz 200/144(.2) 3,467,800 9/1969 Barr 200/144(12)X Primary ExaminerRobert S. Macon AttorntyEdwin E. Greigg ABSTRACT: The invention relates to actuating mechanism for moving switch contacts to thereby open and close a circuit in a vacuum envelope. The actuating mechanism includes an oscillatable lobe associated with pivotal lever means which when motivated cause the contacts in the vacuum envelope to open and close.

Appl. No. 830,347 Filed June 4, 1969 Patented June 1, 1971 Assignee Societe Anonyme de Participations Appareillage Gardy Neuchatel, Switzerland Priority June 13, 1968 Switzerland 8803/68 MOTION TRANSLATING MEANS 11 Claims, 2 Drawing Figs.

US. Cl ZOO/144b, 200/ 153LB PATENIEU JUN 1 l97| MOTION TRANSLATING MEANS This invention relates to improvements in switches and, more particularly, to a lobe construction and actuating means therefor for opening and closing contacts in vacuum envelopes.

In electric switches there is now a tendency to use envelopes for contact in vacuum. These envelopes comprise generally a hollow ceramic body in which is positioned a stationary contact member and a movable contact member. A high vacuum exists inside the envelope, and to ensure complete sealing of the inside of the envelope and of the movable contact member against the outside, use if made of an extensible metal tube, called a boa, a bellows-type breathing tube. The path of movement of the movable piece is relatively short, generally less than mm.

Devices of this general type are well known and by way of example, see the disclosure in the US. Pat. to Peek et al. No. 3,209,101, issued Sept. 28, 1965, which clearly shows means for operation of the circuit breakers in vacuum envelope-type switches on which this invention is a further improvement.

These vacuum envelopes are very advantageous because of their ability to maintain excellent closure of the electric circuit. However, they are very delicate and their lifetime is limited by the lifetime of the bellows-type breathing tube. These envelopes also become defective by impact of the contacting surfaces against each other.

The invention has for its principal object a circuit breaking device comprising at least one envelope for making contact in vacuum comprising a movable contact control piece and an actuating mechanism for such piece. The device is characterized in that the actuating mechanism for control of the movable piece operates in two phases, the first phase assuring the displacement of the mobile piece to form the contact, and the second phase applying to such piece a predetermined force to assure the pressure necessary to provide good contact and to eliminate rebounding of the movable contact.

Another object of the invention is to provide an improved actuating lobe means which is rotatably mounted and arranged so as to transmit pressure through a lever means to open and close the contact elements.

A further object of the invention is to provide an organization of elements, the assembly of which achieves a unique apparatus capable of actuating a multiplicity of envelopes in series.

A still further object of the invention is to provide a construction which enables the contact members to be brought into engagement at such a finely controlled speed that rebounding of the contact members is eliminated.

Yet another object of the invention is to provide a construction which will prolong the mechanical life of the vacuum envelopes as well as be more economical to produce.

Further objects and advantages of the invention will become more apparent upon a reading of the following detailed specification taken in conjunction with the drawing, in which:

FIG. 1 is a horizontal elevation of the new switch, partly broken away, comprising two vacuum envelopes connected in series and FIG. 2 is an enlarged view of the control mechanism for actuating the circuit breakers within the vacuum envelopes of the electric switch mechanism.

Turning now to the drawing, the electric switch shown in FIG. 1 includes a base 1 on which is mounted a housing 2 of insulation material which is adapted to support two horizontally disposed vacuum envelopes 3, 3. These ampules are positioned in longitudinal alignment with each other and are attached by means of their proximate ends to a bracket 4 which is, in turn, mounted on top of the housing 2.

Each vacuum envelope carries a fixed contact member 5, 5' arranged to extend through the bottom of the envelope for purposes which will be known to those skilled in the art. The movable members which carry the circuit breakers (not shown) provided within the envelopes terminate in

headed stems

6,6 positioned in alignment with each other.

As can be best seen in FIG. 2, the stems 6, 6', which are associated with the circuit breakers (not shown), are acted upon by springs 7, 7 seated with one end against the adjacent envelope and with the other end against a collar 8, 8' provided adjacent the end of each stem. The springs 7, 7' urge the mobile contact pieces into circuit breaking positions, namely by keeping the movable circuit breaker contact pieces away from the fixed contact pieces therefore.

The control apparatus which effects the movements of the mobile pieces comprises for each envelope a lever l0, l0 pivoted at one of its ends to a perforated piece ll, 11'. These two last-mentioned perforated pieces are slidably mounted on a rod 12 which is fixed at its opposite ends to the bracket 4. A spring element 13 composed of a collection of resilient rings, well known as Belleville springs, urges the pieces II and 11 away from each other and toward stop collars l4, 14' on the rod 12.

Each lever l0, 10' carries a roller l5, 15' which is posi tioned so as to engage the head of a plunger 16, 16 screwed into the

control stem

6, 6 of the movable member of each vacuum envelope.

The lower extremity of each lever 10, 10' carries a roller l7, 17 for cooperation with two other rollers l8, 18' which are mounted on a lobe-shaped member 19 which is rotatable about an axis shown schematically at 20 with the supporting shaft forming the axis being mounted in bore holes (not shown) in housing 2. The lobelike piece 19 be displaced angularly about by means of a control member 21 which extends up into the housing 2, said member being connected to any kind of an actuator means.

When the lobe-shaped member 19 is rotated, the rollers l8, l8 displace the rollers 17, 17' and with them the lower ends oflevers I0, 10. After the member 19 has turned 90, the centers of the rollers l7, l7, l8 and 18' are in substantial horizontal alignment with one another and the lower ends of levers 10, 10 are thereby separated a maximum distance from each other.

The expansive force of the Belleville spring component 13 is greater than the force that is required for displacing each of the stems 6, 6' and to compress the springs 7, 7. The result will be that during rotation of the member 19, the upper ends of levers l0, 10 will remain in the same position shown in FIG. 2, while the

stems

6, 6 are moved farther away from each other to bring the movable circuit breaker members of the vacuum envelopes into engagement with their respective fixed contact members. Closure of the movable contact pieces of the circuit breaker is obtained slightly before the end of the rotation of member 1?. From the instant when circuit closure occurs, the stems 6 and 6' are not longer able to move still farther away from each other. Since the member 19 terminates its rotation and increases slightly farther the separation of rollers l7, 17' from each other, the final degree of increment of such rotation will compress the spring 13. It will be apparent that the force which the spring 13 exerts upon the ends of arms l0, I0 is transmitted to the heads provided on stems 6 and 6'. The force of spring 13 is indeed increased in proportion to the relative lengths of the lever arms to rollers 17, 17.

When the circuit making contacts are to be opened within the envelope, the member 19 is moved in the opposite direction to return to the position indicated in FIG. 2, and the stems 6, 6' are returned by their springs 7 and 7 to their initial positions to ensure opening of the contacts. A slot 9 is provided in the control member 21 in such a position that the speed of opening of the contacts will not depend on the speed of movement of the member 21. The circuit can therefore be interrupted manually without any special precautions.

It should be stated that the mechanism described above works in two phases. The first phase includes the rotation of the member 19 up to the instant when the circuit making contacts are closed inside the vacuum envelopes. During this first phase the displacement of

stems

6, 6 is effected at a controlled rate which slows down until closure is effected since the movement of rollers l7, 17 is limited by the rotation of the member 19 in accordance with a pseudo sinusoidal function. During this first phase the circuit making contact pieces are moved toward each other by relatively weak forces until they come into actual closed contact.

In the second phase, which commences at the instant when the contacts close, the contact pressure is applied progressive ly to the vacuum envelopes during the last portion of the rotation of member 19. Since the spring 13 is very strong, the contact pressure provided for the vacuum envelopes is already obtained after only a slight movement of the pieces 11 and ll toward each other. This means that the application of the contact pressure commences almost immediately after the control members move out of their dead center positions. The result will be that at the instant of closure of the contacts, the speed at which the contact members approach each other is very slow and is in phase with the retardation. In this manner all rebounding of the contact members from each other will be avoided and there will be a minimum accumulation of metallic powder. This arrangement makes it possible to avoid all hammering of the contacting circuit making and breaking members and all premature separation of metallic dust as a result of arcing of the contacts. Experiments have shown that the control mechanism described greatly prolongs the mechanical life of the vacuum envelopes.

As far as insulation from the ground is concerned, it can be realized very simply by using a control member 21 of insulating material. insulation can also be obtained by forming the levers l0, of reinforced epoxy resin. Such a construction is very advantageous because the shaft could then be grounded and could carry several actuator members 19 to actuate several circuit breakers, each comprising one or two vacuum envelopes. These circuit breakers can then be used to open simultaneously the different phases of a polyphasc circuit, or can be connected in series to break in one phase a higher voltage than that which corresponds to the maximum voltage to be broken by two envelopes in series. It is therefore possible to combine these two possibilities and to obtain a unique apparatus comprising, for example, six envelopes in series for each phase of a three-phase circuit, by providing on the shaft 20 nine members such as that illustrated at 19, each controlling two envelopes of the kind described above.

It is indeed possible to provide many variants of the above described apparatus. Especially where only a single vacuum envelope is used, one of the levers 10 or 10 can be omitted. The control mechanism can also assume other forms and in particular articulated mechanisms are especially convenient because they also have a dead center.

It is also not absolutely necessary to use a dead center at all. The movable contact circuit member of the vacuum envelope can also be acted upon by a mechanism exerting an increasing force upon the movable pieces from the beginning of the closure movement, the velocity of closing of this piece being, however, controlled by a suitable mechanism, for example, by a hydraulic shock absorber. in this manner, the displacement of the movable piece occurs at a controlled speed, and the contact pressure would not be applied to the movable piece until after the contact has been closed. The same result could also be produced by a hydraulic mechanism for controlling the movable piece, as by connecting a control piston which actuates the movable piece, with a chamber that is under the required hydraulic pressure. However, this connection should be obtained by means of a passageway that is calibrated to limit the speed of the piston at the time of its closing movement and making it possible then to control the speed of closing of the movable member.

We claim:

1. An electric circuit-making and -breaking apparatus comprising a fixed contact and at least one movable contact for operation in vacuum envelope and having an open and a closed position, a two-step working mechanism for actuation of said movable contact, said mechanism comprising plural lever means and associated rotatable lobe means arranged upon rotation to produce a decrease in the speed of the mova ble contact by limited movement of said lever means in a first direction during said first step, said mechanism further includ ing pressure-limiting means for limiting the pressure applied to said movable contact when it is brought into closed position with the fixed contact at the end of said first step, whereby rebound of said contact is avoided, the second step mechanism also including pressure-increasing means after ini' tial contact is made between the fixed and movable contacts by moving the levers in a second direction to increase the pressure applied to said movable contact until the nominal contact pressure is obtained.

2. An electric circuit-making and -breaking apparatus as claimed in claim 1, wherein plural envelopes are arranged to be operated in series.

3. An electric circuit-making and -breaking apparatus as claimed in claim 1, wherein a plurality of roller means are affixcd to said lever means.

4. An electric circuit-making and -breaking apparatus as claimed in claim 3, wherein at least one of said roller means is arranged to cooperate with said movable contact.

5. An electric circuit-making and -breaking apparatus as claimed in claim 3, wherein the lobe element includes roller means arranged to cooperate with the roller means on said levers, said lobe carried roller means being arranged upon rotation to move said levers in opposite directions.

6. An electric circuit-making and breaking apparatus as claimed in claim I, wherein plural resilient means cooperate with said lever means and the other of said roller means is in constant rolling contact with means on said lobe.

7. An electric circuit-making and -breaking apparatus comprising a fixed contact and a movable contact each of which lies in a fixed plane and is arranged for operation in a vacuum envelope and has an open and closed position, a two step working mechanism for actuation of said movable contact, said mechanism including plural levers a portion of each of which intersects the plane of said contacts and which also include portions extending therebeyond that are relatively fixed in spaced relation while being adjustably interconnected one to the other, the other terminal end portions of said levers including means to cooperate with means carried by a rotatable lobe element, means for rotating said lobe in a first step to initially urge said levers away from each other and to bring said contacts into initial engagement, said last-named means upon movement to its second step of rotation thereby forcibly urging the contacts into tighter engagement.

8. An electric circuit-making and -breaking apparatus as claimed in claimed 7, wherein the portions of the levers that are adjustably interconnected are maintained in spaced relation by resilient means.

9. An electric circuit-making and -breaking apparatus as claimed in claim 7, wherein said vacuum envelope further includes an axially disposed fixed contact member arranged to extend beyond the confines thereof.

10. An electric circuit-making and -breaking apparatus as claimed in claim 8, wherein during the second step of rotation of said lobe element the resilient means which maintains the levers in spaced relation is compressed.

11. An electric circuit-making and -breaking apparatus as claimed in claim 8, wherein the resilient means consists of a Belleville spring.

Claims

1. An electric circuit-making and -breaking apparatus comprising a fixed contact and at least one movable contact for operation in vacuum envelope and having an open and a closed position, a twostep working mechanism for actuation of said movable contact, said mechanism comprising plural lever means and associated rotatable lobe means arranged upon rotation to produce a decrease in the speed of the movable contact by limited movement of said lever means in a first direction during said first step, said mechanism further including pressure-limiting means for limiting the pressure applied to said movable contact when it is brought into closed position with the fixed contact at the end of said first step, whereby rebound of said contact is avoided, the second step mechanism also including pressure-increasing means after initial contact is made between the fixed and movable contacts by moving the levers in a second direction to increase the pressure applied to said movable contact until the nominal contact pressure is obtained.

3. An electric circuit-making and -breaking apparatus as claimed in claim 1, wherein a plurality of roller means are affixed to said lever means.

6. An electric circuit-making and -breaking apparatus as claimed in claim 1, wherein plural resilient means cooperate with said lever means and the other of said roller means is in constant rolling contact with means on said lobe.