1. Field of the Invention
The invention relates to an apparatus for remotely actuating a circuit breaker with two stable positions corresponding to a switch-on position and a switch-off position. The apparatus has a drive mechanism with an electric motor, a first and a second switch for switching the electric motor on and off, a transmission, a coupling mechanism, which is provided for mechanically coupling the drive mechanism to the breaker and a lever. The transmission is capable of being positioned in two basic positions, and the lever is capable of being positioned in two end positions. The lever is capable of being moved from its one end position into the other end position with the aid of the drive mechanism in a remotely actuable fashion.
Circuit breakers are used for disconnecting circuits in the event of excess current. A circuit breaker isolates the circuit as soon as its rated current level has been exceeded by a specific factor. This protects the load or the line from damage or destruction owing to the thermal influence of the current. In general, there are thermal, thermal-magnetic, magnetic and hydraulic-magnetic circuit breakers and line circuit breakers.
Switches are known, including circuit breakers, which are mechanically coupled to an apparatus for remote actuation. Such apparatuses make it possible to actuate a switch remotely. In this case, a switching mechanism of the circuit breaker is acted upon in particular via a manual actuator or switching button which can be actuated manually. An apparatus for remotely actuating a switch makes it possible to switch a circuit breaker both off and on remotely. In this case, auxiliary electrical energy is required for the electric motor of the apparatus.
Such an apparatus is specified, for example, in U.S. Pat. No. 5,838,219. Therein, a circuit breaker with a remote drive fitted thereto is described, the movements of the manual actuator, which is, in the form of a switching rocker, of the circuit breaker are controlled via a switching rocker of the remote drive. The switching rocker of the remote drive is capable of being actuated with the aid of a drive mechanism. For this purpose, an actuating member moves between two positions. In the case of manual actuation of the switching rocker of the circuit breaker or of the remote drive, the actuating member needs to be changed over in order to make future remote actuation possible.
It is accordingly an object of the invention to provide an apparatus for remotely actuating a manual actuator of a circuit breaker, which overcomes the herein-mentioned disadvantages of the heretofore-known devices of this general type, which makes safe and reliable remote actuation of a manual actuator of a circuit breaker possible even in the event of manual actuation of the manual actuator, in the meantime.
With the foregoing and other objects in view there is provided, in accordance with the invention, an apparatus for remotely actuating a circuit breaker having two stable positions including a switch-on position and a switch-off position. The apparatus contains a drive mechanism. The drive mechanism has an electric motor, switches, including a first switch and a second switch, for switching the electric motor on and off, and a transmission capable of being positioned in two basic positions, including a first basic position and a second basic position. A coupling mechanism having a lever is provided for mechanically coupling the drive mechanism to the circuit breaker. The lever has two end positions and are capable of being moved from a first end position into a second end position with an aid of the drive mechanism. The drive mechanism is configured such that, in an event of the lever being moved over manually from the first end position into the second end position, one of the first and second switches is actuated, resulting in the transmission moving over from the first basic position into the second basic position.
Accordingly, the apparatus has a drive mechanism, which is configured such that, in the event of the lever being moved over manually from one end position into the other end position, one of the switches is actuated such that the transmission is moved over from one basic position into the other basic position.
A decisive advantage of the configuration can be considered to be that synchronization of the manual and remote-controlled changeover of the manual actuator is achieved, i.e., in the event of manual actuation of the manual actuator, the drive mechanism is automatically followed. Simple and reliable operation of the apparatus is made possible by two basic positions of the transmission being defined, depending on the actuation of one of the two switches. With the aid of the drive mechanism having such a configuration, the transmission is automatically moved over from one of the two basic positions into the other, which two basic positions are correlated with the two end positions of the lever or with the switch-on and switch-off position of the manual actuator, irrespective of whether the manual actuator is switched on or off manually or by remote control. Since one of the two switches is used for the process of the drive mechanism automatically being followed, no additional switch or tripping mechanism is required, which makes a compact and simple configuration possible.
Automatic synchronization takes place even after electric tripping of the circuit breaker. In the event of there being no operating voltage available to the drive, the circuit breaker remains ready for operation in an unrestricted fashion. Synchronization of the drive with respect to the respective switching state of the circuit breaker automatically takes place once the operating voltage has been applied.
Preferably, the first switch is a normally open contact, and the second switch, which is connected in series therewith, is a normally closed contact. The normally open contact is defined as being a switch which, in its normal, unactuated position, is open (NO contact). The normally closed contact is defined, in contrast, as being a switch which is closed in its normal position (NC contact). The electric motor is therefore at a standstill if both switches are actuated at the same time or both are not actuated at the same time. In the first basic position of the transmission, preferably both switches are not actuated, i.e. the circuit for supplying the electric motor is opened by the normally open contact. Moving the manual actuator over closes the first switch, and the transmission runs until the second switch is actuated and thereby opened. This corresponds to the second basic position of the transmission. Irrespective of whether the manual actuator is moved over by remote actuation or manually, in both cases the transmission is moved from one basic position into the other basic position by use of the two switches being closed or opened in combined fashion. Owing to this configuration, which is simple in terms of circuitry, and interaction of the components, reliable operation of the apparatus is ensured.
Preferably, the lever has an axis of rotation, about which it can be rotated when switching over from one end position to the other end position along an arc of a circle. The rotary movement of the lever is correlated with the rotary movement of the manual actuator; in particular it corresponds to the rotary movement of the manual actuator. Owing to the rotary movement of the manual actuator being reproduced by the rotary movement of the lever, a simple mechanical connection between the circuit breaker and the apparatus is made possible. In this case, only a correlation of the end positions of the lever with the basic positions of the transmission is required, which is achieved by simple mechanical measures.
Further preferably, the drive mechanism has a cam disk, the two basic positions of the transmission being defined via the cam disk and, for example, being offset by half a revolution of the cam disk. Therefore, starting from one of the basic positions of the transmission and one of the end positions of the lever, which are related to one another, after half a revolution of the cam disk the other basic position of the transmission is reached at the same time as the other end position of the lever, and the electrical supply to the electric motor is switched on or off.
In accordance with one preferred embodiment of the apparatus, the cam disk is capable of rotation only in one direction. The drive mechanism therefore only needs to be configured for one direction of rotation and polarity reversal of the electric motor for the purpose of changing the direction of rotation is not required.
Advantageously, the cam disk actuates the first switch via a direct contact. The switch is in particular positioned such that it is in touching contact with the circumferential side of the cam disk, and the switch is actuated by this touching contact. In order to switch the switch off, a cutout is expediently introduced at at least one point along the circumferential side of the cam disk.
It is furthermore advantageous if the lever is connected to the cam disk via a coupling element, which is disposed on the cam disk such that it can rotate at an articulation point, the articulation point being spaced apart from an axis of rotation of the cam disk. The articulation point is therefore displaced along a circular path when the cam disk rotates and, with it, also one side of the coupling element. The rotatable connection between the coupling element and the cam disk ensures a high degree of flexibility of the movements of the coupling element along the entire circular path.
Preferably, the coupling element has a slot in the form of a slotted link, in which slot a pin of the lever runs. The slot likewise provides a high degree of flexibility of the connection between the coupling element and the lever. The pin of the lever can therefore move freely along the slot during the circular movement of the coupling element.
Furthermore, the coupling element preferably has an attachment, which is provided for the mechanical contact with the second switch. The attachment is configured such that the contact with the switch is only produced at one point or in one region of the path described by the coupling element during its movement. Owing to the series circuit containing the two switches, which are in the form of a normally closed contact and a normally open contact, the energy supply to the electric motor is interrupted by this measure in a predetermined transmission position. The contact between the attachment and the second switch is therefore provided for the purpose of interrupting the circuit as soon as the cam disk is located in one of the basic positions.
Preferably, the first switch is capable of being actuated by the coupling element or by the cam disk via direct mechanical contact. In the event of remote-controlled actuation of the manual actuator of the circuit breaker, the electric motor is started up with a short current pulse, the cam disk rotates and actuates, with its circumferential side, the first switch, with the result that the circuit is closed. In the event of a manual change in the end position of the lever, in contrast the first switch is actuated via a mechanical contact with the coupling element. The change in position of the lever therefore also automatically moves the coupling element, with the result that the first switch is actuated, the electric motor is started, and the transmission is brought automatically into its other basic position.
In one advantageous embodiment of the apparatus, the lever has a driver, in particular in the form of an aperture, which is provided for accommodating a coupling member in interlocking fashion, which connects the apparatus to the manual actuator. Owing to the coupling element, the correlation of the lever with the manual actuator takes place by the rotary movement of the lever being transmitted to the manual actuator. If the circuit breaker and the apparatus for remotely actuating the circuit breaker are disposed next to one another, the coupling element may be in the form of a pin. The pin conducts the torque of the manual actuator to the lever, and vice versa.
In one preferred configuration, the electric motor is capable of being switched on and off by a pushbutton. The pushbutton triggers the current pulse to the electric motor, the electric motor actuates the transmission and brings it into its other basic position, in which the circuit is interrupted. At the same time, the lever is brought into its other end position, and its rotary movement is in the process transmitted to the manual actuator.
Advantageously, the apparatus has separate ON and OFF pushbuttons or a changeover switch, on whose actuation the transmission is capable of being moved over from its first basic position into the second basic position, and vice versa.
In another advantageous embodiment of the apparatus, only one OFF pushbutton is provided, on whose actuation the transmission is moved into a basic position, which is correlated with the switch-off position of the manual actuator.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an apparatus for remotely actuating a manual actuator of a circuit breaker, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings.
Functionally identical parts are provided with the same reference symbols in the figures. Referring now to the figures of the drawing in detail and first, particularly, to
The first switch 15 of the two series-connected switches 15, 17 is a normally open contact (NO contact) and the second switch 17 is a normally closed contact (NC contact). The second switch 17 is closed in its normal position, but the first switch 15 is not. The circuit is open. The circuit is closed by the first switch 15 being actuated. In the event of a subsequent actuation of the second switch 17, it is opened again and the electrical supply to the electric motor 13 is interrupted. Therefore, the electric motor 13 is only running when the first switch 15 has been actuated and the second switch 17 has not been actuated. On the other hand, if only the second switch 17 is actuated, it is opened and the circuit is also opened.
The manner in which the apparatus 1 functions will be explained in more detail with reference to
In the event of a remote actuation of the apparatus, the cam disk 29 is brought into the ON basic position illustrated in
In order to move the cam disk 29 over from the basic position shown in
Owing to renewed actuation of the pushbutton T, the electric motor 13 again receives a current pulse and sets the transmission 9 in motion. The pushbutton T needs to be pressed until the attachment 41 on the coupling element 31 releases the actuator 17a at the second switch 17 and the electrical supply to the electric motor 13 is taken over by the NC contact of the second switch 17 together with the first switch 15, which is connected in series. Owing to the rotary movement of the cam disk 29, the coupling element 31 draws the pin 43 via the slot 39, and therefore the lever 7, into the OFF end position (see
If the circuit breaker 5 is switched on manually by the manual actuator 3, the drive mechanism 11 therefore automatically follows into its associated basic position. The actuator 15a, first actuated by the edge of the coupling element 31 and then by the cam disk 29, closes the circuit.
If the circuit breaker 5 is switched off manually by the manual actuator 3, the drive mechanism 11 follows automatically again. The lever 7, as shown in
An exploded illustration of the individual components of the apparatus 1 is illustrated in
The circuit breaker 5 with the manual actuator 3 in the form of a switching rocker and the apparatus 1 for remotely actuating the manual actuator 3 are shown in
In the embodiment of the apparatus 1 shown in
In
The exemplary embodiment in
In accordance with the variant embodiment in
For all subsequent variants which are shown in
Number | Date | Country | Kind |
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10 2005 024 270 | May 2005 | DE | national |
This is a continuing application, under 35 U.S.C. §120, of copending international application No. PCT/EP2006/003187, filed Apr. 7, 2006, which designated the United States; this application also claims the priority, under 35 U.S.C. §119, of German patent application No. DE 10 2005 024 270.7, filed May 27, 2005; the prior applications are herewith incorporated by reference in their entirety.
Number | Name | Date | Kind |
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3332043 | Camp | Jul 1967 | A |
5838219 | Du et al. | Nov 1998 | A |
Number | Date | Country |
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37 11 138 | Oct 1988 | DE |
0 872 867 | Oct 1998 | EP |
0 883 150 | Dec 1998 | EP |
Number | Date | Country | |
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20070222543 A1 | Sep 2007 | US |
Number | Date | Country | |
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Parent | PCT/EP2006/003187 | Apr 2006 | US |
Child | 11804681 | US |