Abstract
The present invention refers to a switch device with at least one contact point, the contact point having a first contact and a second contact, the first and second contacts being spaced apart from one another in an open position and electrically contacting one another in a closed position, the contact point being assigned an arc blowout device for generating a magnetic blowing field, the blowout field being such that an arc produced when the contact point is opened is blown away from the contact point. In accordance with the invention, at least one of the two contacts is provided with a non-conductive cover on a non-contact-facing side which faces away from the other contact, which cover prevents a base point of the arc from crossing the non-contact-facing side.
Claims
1. A switch device comprising at least one contact point, the contact point having a first contact and a second contact, the first and second contacts being spaced apart from one another in an open position and electrically contacting one another in a closed position, the contact point being assigned an arc blowout device for generating a magnetic blowout field, the blowout field being such that an arc produced when the contact point is opened is blown away from the contact point, wherein at least one of the two contacts has a non-conductive cover on a non-contact-facing side which faces away from the respective other contact, which cover prevents a base point of the arc from crossing the non-contact-facing side, wherein the cover has, on a longitudinal side of the contact with the cover which runs substantially parallel to magnetic field lines of the blowout field, a recess which is arranged and formed in such a way that the base point of the arc runs into the recess when the arc is blown away from the contact point.
2. The switch device according to claim 1, wherein that the switch device has a double interruption with two contact points, the first contact of each of the two contact points being designed as a fixed contact, and the second contact of each of the two contact points being part of a common contact bridge which is aligned parallel to magnetic field lines of the blowout field.
3. The switch device according to claim 2, wherein each contact point is assigned an arc extinguishing device.
4. The switch device according to claim 3, wherein the switch device is designed for bidirectional operation, the arc extinguishing device having extinguishing elements which are arranged on both sides of the common contact bridge.
5. The switch device according to claim 4, wherein the extinguishing elements are also arranged on the non-contact-facing side of the common contact bridge.
6. The switch device according to claim 4, wherein the switch device furthermore has an arcing chamber cover which is designed such that plasma which is generated by the arc and exits between the extinguishing elements arranged on the non-contact-facing side of the common contact bridge is deflected laterally.
7. The switch device according to claim 6, wherein the arcing chamber cover can be fastened without tools by means of snap-in hooks to the assembly consisting of arc extinguishing device and arc blowout device.
8. The switch device according to claim 3, wherein the fixed contacts are wider than the common contact bridge in a direction orthogonal to the magnetic field lines of the blowout field.
9. The switch device according to claim 8, wherein the fixed contacts extend as far as the arc extinguishing device and simultaneously serve as arc guide plates.
10. The switch device according to claim 3, wherein arc extinguishing device, together with the arc blowout device, forms an assembly which can be removed without tools and which can be fastened to a housing of the switch device by means of snap-in hooks.
11. The switch device according to claim 1, wherein the cover extends from the non-contact-facing side of the respective contact via an edge of the respective contact which extends essentially orthogonally to magnetic field lines of the blowout field, to a free end face of the respective contact, so that the end face is also at least partially covered by the cover.
12. The switch device according to claim 1, wherein the recess is of arcuate design.
13. The switch device according to claim 1, wherein the cover consists of plastic.
Description
(1) An embodiment of the present invention is explained in more detail below using drawings.
(2) FIG. 1: shows an oblique view of a switch device according to the invention,
(3) FIG. 2: shows a perspective longitudinal section through the switch device according to the invention from FIG. 1 along the section line II drawn in FIG. 1,
(4) FIG. 3: shows a cross-section of the switch device according to the invention from FIGS. 1 and 2 along the section line III shown in FIG. 1,
(5) FIG. 4: shows a top view of the switch device according to the invention from FIGS. 1 to 3 without arc extinguishing means,
(6) FIG. 5: shows the representation from FIG. 1 with an additional arcing chamber cover attached to the switch device according to the invention, and
(7) FIG. 6: shows a side view of the switch device according to the invention from FIGS. 1 to 5 with arcing chamber cover.
(8) For the following embodiments, identical parts are designated by identical reference numerals. If a Figure contains reference numerals which are not described in detail in the corresponding Figure description, reference is made to preceding or subsequent Figure descriptions.
(9) FIG. 1 shows a perspective view of a switch device 1 according to the invention, showing the housing 20, the two connecting contacts 25 of the switch device and an arc extinguishing means 16 located in the upper part of the switch device according to the invention, the components of which are described in more detail below.
(10) FIG. 2 shows a perspective longitudinal section through the switch device according to the invention along the section line II drawn in FIG. 1. This illustration shows that switch device 1 has a double interruption with two contact points 14 and 15. Each contact point consists of a fixed contact 2 and a moving contact, whereby the two moving contacts are combined to form a common contact bridge 3. The two fixed contacts 2 are led out of the housing of the switch device and thus simultaneously form the two connection contacts 25 of the switch device. Each of the two fixed contacts 2 has a corresponding contact surface 4, which can be brought into contact with an opposite contact surface 5 of contact bridge 3. When the switch device is closed, an electrical contact is established between the fixed contact 2 and contact bridge 3 via the contact surfaces 4 and 5. The electromagnetic drive of contact bridge 3 is shown in the lower part of the Figure and is not relevant for the invention.
(11) FIG. 3 shows a cross-section of the switch device according to the invention along the section line III drawn in FIG. 1. The section was laid through the first contact point 14. The illustration also applies to the second contact point 15. The switch device comprises an arc blowout device consisting essentially of the permanent magnets 6 shown in FIG. 3 and the corresponding pole plates 7 shown in FIGS. 1 and 2. The arc blowout device generates a magnetic blowout field which is aligned parallel to the longitudinal extension of the contact bridge 3, the longitudinal extension of the contact bridge being defined by a mental connection of the two contact points 14 and 15.
(12) When the contact point is opened, a switching arc 24 is created between the contact surfaces 4 and 5, which is blown away from the contact point by the magnetic blowout field transverse to the longitudinal extension of the contact bridge. Depending on the current direction, the switching arc 24 is blown either to the left or to the right as shown in FIG. 3. FIG. 3 shows several positions of the switching arc 24. It can be clearly seen that the switching arc 24 is more strongly bent and thus stretched the further it is blown away from the contact point. The lower base point 10 of the switching arc moves outwards along the fixed contact 2. The fixed contact 2 is considerably wider than the contact bridge 3 and thus also serves as an arc guide plate. The other base point 9 moves from the contact surface 5 via the long side of the contact bridge 3 to the upper side of the contact bridge, which faces away from the fixed contact 2. In order to prevent the base point 9 from moving further and virtually encircling the contact bridge, the non-contact-facing upper side of contact bridge 3 has a non-conductive, insulating cover 8 made of a high-temperature-resistant plastic, e.g. polyetherimide.
(13) The cover 8 is best shown in the plan view from FIG. 4, in which the arc extinguishing device 16 is not shown for the sake of clarity. The cover 8 extends from the non-contact-facing side of the contact bridge via an edge at the free end of the contact bridge which is substantially orthogonal to the magnetic field lines of the blowout field, to the free end face 11 of the contact bridge, so that the end face is also covered by the cover at least in the upper region. This prevents the arc 24 from moving along the end face 11 of the contact bridge. The front cover is provided on both ends 11 of the contact bridge. On the long sides 12 of the contact bridge 3, the cover 8 has two recesses 13 per contact point, which are arranged and designed in such a way that the base point 9 of the switching arc 24 runs into the recess 13 when the arc is blown away from the contact point. The base point 9 of the arc 24 is captured, so to speak, in the recess, effectively preventing the base point from breaking in an undesirable direction. As shown in FIG. 4, the recess is circular in shape.
(14) As FIG. 3 shows, the arc extinguishing device 16 has several extinguishing elements 17 at both sides of the contact bridge and at the non-contact-facing upper side of the contact bridge, which extinguish the switching arc 24. The extinguishing elements 17 are made of plastic and are designed in one piece with a holder for the arc extinguishing device 16. The extinguishing elements can of course also be made of ceramic. Together with the arc blowout device, consisting of the permanent magnets 6 and the pole plates 7, the arc extinguishing device forms a removable assembly without tools, which is attached to the housing 20 of the switch device according to the invention by means of snap-in hooks 18. The snap-in hooks 18 are designed as resilient tongues, the ends of which snap into place with corresponding latching elements 19 of the housing 20. The snap-in connection is secured against overloading of the material caused by overstretching when the snap-in is released by a bracket 21 on the housing side and against unintentional release by attaching a locking device, e.g. by means of a sealing.
(15) As FIGS. 5 and 6 show, the switch device according to the invention can optionally be equipped with an arcing chamber cover 22, which can also be attached to the arc extinguishing device without tools by means of snap-in hooks 23. The arcing chamber cover 22 is arranged on the upper side of the switch device according to the invention and causes a deflection of the plasma, which is generated by the arc and which passes outwards through the extinguishing elements 17 arranged above the non-contact-facing upper side of the contact bridge. The deflection takes place from the side to the outside. As a result, no safety distance must be maintained between the top of the switch device according to the invention and other components or parts. In many cases, the arcing chamber cover 22 facilitates the installation of the switch device 1 according to the invention.
