DE4302185C1 - Two-pole electric switch - with dead-time coupling path for switch cams between sliding operating element and each switch wiper - Google Patents

Abstract

The switch has a sliding operating element (2) cooperating with two switch wipers (3, 4). Their pivot bearings (5, 6) are located at the same height within the switch housing. Each switch wiper carries a respective movable contact (9, 10) cooperating with a counter-contact (7, 8) carried by the switch housing. A switch cam (15, 16) is provided between the operating element and each switch wiper. Both cams are coupled together in the operating direction via a dead-time path (22) providing a required offset between the operation of the switch cams. ADVANTAGE - Ensures even wear of both switch contact sets.

Description

The invention relates to an electrical switch for two-pole opening and closing of a circuit with one slidably mounted in a switch housing Actuator located between two paddles, in particular with tilt bearings arranged at the same height, each rocker switch one with a housing-fixed Counter contact cooperating, movable contact carries and the two movable counter contacts in the switch-on position or the switch-off position or a switch position are feasible. Such switches are both as On-off switch also known as a switch. In the Such switches are generally used as mains switches. Due to the tolerances for bulk items, which ones switches are generally inevitable is an exact simultaneous opening and closing in not possible in practice. One achieves that the two Normally open contacts with a delay of less than 1 ms close so that switching on both contacts, which takes about 1 to 3 ms, occurs almost simultaneously. At the Switching off is a clear time shift shift between the two contacts. This leads to one uneven contact wear, being the worst Always trap only one pair of contacts the entire electrical Function. Opening and closing the contacts under load causes contact erosion and consequently  leads to the aforementioned uneven contact wear or that constant opening and closing of only one of the two contacts under load to a quasi halved lifespan of this Switch.

DE 34 39 469 A1 is a generic switch known. Because of the inevitable as I said Manufacturing tolerances cannot be ruled out that the two rocker switches when pressing this switch tilt with a time delay, for example with a switch with work contacts these in short succession Switch position, although one is from the construction can assume that a simultaneous opening and It is intended to close the contact pairs. Act accordingly it is an electrical switch with the disadvantages mentioned above.

A similar to the switch of DE 34 39 469 A1 and equivalent switch describes the DE 37 13 775 A1. At the illustrated and described two-pole version this switch can vary depending on the particular Tolerances of the contacts at the same time or with a short time delay be opened and closed. In terms of shifted switching and reset points can Conditions when opening and closing the contacts also turn out differently. So are also at this electrical switch the disadvantages mentioned available.  

DE 36 17 049 A1 is a safety interrupter became known with the forced opening of his normally closed contacts. He has two in the longitudinal direction in an insulating housing separate pairs of fixed contacts as well as a normally closed contact bridge and a normally open contact bridge. Each of these bridges works with a fixed contact pair together. Here too is the actuation of the plunger basically a simultaneous two-pole opening and The aim is to close the contact pairs. Due to the complicated formation of this switch is still one given a higher probability that the contact pairs not be opened or closed at the same time, but briefly staggered, so that this switch too a contact erosion on one and the same pair of contacts, both when opening and when closing. No special precautions are required for this switch either met this unfavorable perspective regarding the To prevent contact erosion.

Finally, DE 35 46 060 A1 Switching device in the form of an electrical breaker with successive closings and simultaneous Known openings of the contacts of his two switches become. It is used, for example, to stop one fast running electric motor. This is targeted aimed that by pressing the button the two  Switches, the construction of which is not shown in detail, can be actuated one after the other by the plunger by pressing in on Direction of offset staggered bevels the switch plunger are attached. Through a special one Construction can be achieved at least approximately simultaneous closing of the switch contacts of both Circuit breaker.

The problem with this switch is different from that of the switches discussed above and also that according to the invention. In this respect, he could not be a role model for the form switch according to the invention.

The object of the invention is now a switch of the type mentioned in such a way that with Security an even contact wear of both Contact pairs is achieved, for example, by one always closes under load, while the other always under Load opens or vice versa.

To solve this problem, the invention proposed that the electrical switch according to the Preamble of claim 1 according to the characterizing Part of this  Claim is formed. Because now on purely mechanical Forced way opening the two contacts as well is like the closing, but with the Provided that, for example, the first movable contact constantly closes under load while the second movable Contact opens constantly under load, one reaches uniform loading of both contact pairs and therefore also an equal contact erosion of the latter. this leads to a substantial increase or doubling of the service life this two-pole switch. It is irrelevant whether it is an on-off switch or a toggle switch acts.

The contacts are opened and closed of course in the manner mentioned above, only delayed by milliseconds. this is not ultimately also depends on the speed at which the switch actuator is moved. The size of the Lost motion depends on the design of the switch in the individual from. Tolerance fluctuations no longer play this way great role as with the previously known electrical switches of the generic type.

A further development of the invention provides that each Tilt bearing electrically conductive with a switch Connection element is connected, d. H. the electric current flows from the tilting bearing via the rocker switch and its movable contact to fixed contact or vice versa.  

Each movable contact is expediently on one resilient arm attached, and this forms part of the Rocker switch. There is another in this context Embodiment of the invention in that each rocker switch a has approximately U-shaped shape, with an inner U-leg is applied to the assigned switching cam while an outer one U-leg the movable contact, especially on his free end, carries.

A preferred variant of the invention is thereby characterized in that each switching cam on one in Switch housing mounted sliding element attached, is molded in particular and the two sliding elements are displaceable by means of a common actuator. Your Shifting movement lead them in the invention Partially staggered due to the lost motion.

A further development of the invention results from claim 6. If you move the actuator with the sliding element of the first Nockens, seen in the direction of displacement, with little play hitched, so this is particularly beneficial for assembly. With regard to shifting, there is no play-free coupling further possible. The actuator is preferred with two lateral approaches or a common one, after both Provided sides approach, the one the backlash-free or almost backlash-free coupling causes while the other intervenes in the lost motion.  

Another embodiment of the invention results from Claim 7. Because of its lower number of parts, it is cheaper to manufacture and, above all, requires one less installation effort. Above all, this results also from the further developments according to claims 8 and 9.

The configuration according to FIG Claim 10, which results in a very compact switch.

Two exemplary embodiments are described below with reference to the drawings explained in more detail.

Here represent:

Figs. 1 to 4 are successively schematic representation of four reached positions of the switching mechanism of a two-pole switch with normally open contacts of a first embodiment;

Fig. 5 to 8 is a corresponding view of a second variant;

Figure 9 is a simple schematic diagram of a two-pole power switch with working contacts.

Fig. 10 shows a further circuit diagram of a two-pole, formed as a toggle switch.

A two-pole electrical switch with two normally open contacts, i.e. two normally open contacts, has an actuator 2 , which can be moved in a conventional switch housing ( not shown) in the sense of the double arrow 1, and two at approximately the same height, also arranged opposite one another, in the drawing only schematically indicated, known rocker switches 3 and 4 . The rocker switch 3 is mounted on a rocker bearing 5 of a known type, while the rocker bearing of the rocker switch 4 is designated by 6 . Both tilt bearings are live, ie the current is supplied, for example, via the tilt bearing 5 and derived via the fixed contact 7 when the left contact pair is closed. The fixed contact of the right contact pair is designated 8 . The associated movable contacts have the reference numbers 9 and 10 . They have a distance from their fixed contacts in FIGS . 1 and 5, ie the two-pole switches are open in the starting position in both exemplary embodiments.

In both variants of the invention, the movable contacts are located on the rocker switches 3 and 4 . The latter have, for example, a U-shaped shape, with the respective outer U-leg carrying the movable contact 9 or 10 relative to the center of the switch, in particular at its free end. This U-leg is tiltably mounted on the associated tilt bearing 5 or 6 in the sense of the double arrow 11 or 12 . The respective inner U-leg 13 or 14 of the rocker switch 3 or 4 abuts a switching cam 15 or 16 . A line of contact 17 or 18 placed through the respective contact point is at a distance in the direction of actuation 1 from a tilting plane 19 or 20 placed through the tilting bearing. This leads to the fact that, due to the spring elasticity of the rocker switches 3 and 4, the rocker switch 3 is spring-loaded in the clockwise direction, while the rocker switch 4 is exposed to a torque in the counterclockwise direction. As a result, both movable contacts are kept in their open position. In both exemplary embodiments, it is provided that the tilting planes 19 and 20 extend from one another.

The first switching cam 16 is located on the actuator 2 , and it is in particular made in one piece with it. In contrast, the second switching cam 15 is attached to a sliding element 21 which is slidably mounted on the actuator 2 . The sliding element 21 cannot be moved as desired on the actuator 2 in the sense of the double arrow 1 , but only within a predetermined range, which at the same time represents a lost motion path 22 . This is achieved in that, for example, there is a recess 23 on the actuator 2 , which is bounded at the bottom by a surface 24 and at the top by the inner surface 25 of an extension 26 projecting perpendicularly from the image plane. The lost motion distance 22 thus results from the distance between the two driver surfaces 24 and 25 minus the thickness of the second switching cam 15 measured in the direction of displacement 1 . Incidentally, it takes Fig. 1 that the two contact lines 17 and 18 are displaced in the actuating direction 1 against each other, wherein the contact line 18 of the common tilting line 19, 20 has a greater distance than the contact line 17.

If the actuator 2 is shifted from the position shown in FIG. 1 in the direction of arrow 27 , this also leads to a relative displacement of the actuator 2 with the first switching cam 16 relative to the sliding element 21 with the second switching cam 15 . When the lost motion path 22 is overcome, the driver surface 24 hits the second switching cam 15 . The switch position shown in FIG. 2 has now been reached. During the passage through the lost motion path 22 , the contact line 18 has come beyond the tilting plane 19 , 20 , which has caused the rocker switch 4 to tilt in the clockwise direction. As a result, the movable contact 10 has come into contact with the fixed contact 8 . However, because it is a two-pole switch, these contacts are closed when de-energized.

If, according to FIG. 3, the actuator 2 is pushed further in the direction of the arrow 27 until the line of contact 17 has also got beyond the tilting plane 19 , 20 , the rocker switch 3 is also pivoted, specifically because of the symmetrical arrangement of the two rocker switches in the Counterclockwise. This leads to contact between contacts 7 and 9 . Because the second pair of contacts is now closed, contacts are made between contacts 7 and 9 under load.

The displaceable and tiltable parts have reached their actuation end position in FIG. 3. If, starting from this, the actuator is moved back by hand or, preferably, by spring force in the direction of arrow 28 , the spring then acting on the actuator, this leads to a relative movement of the actuator 2 with respect to the sliding element 21 . The contact line 18 then crosses the tilt plane 19 , 20 and this results in a torque on the rocker switch 4 in the counterclockwise direction. The movable contact 10 lifts off its fixed contact 8 . This happens under load with contact erosion.

If, starting from the position reached in FIG. 4, the resetting movement of the actuator 2 in the direction of arrow 28 continues, the contact line 17 also crosses the tilting plane 19 , 20 , which is a torque on the rocker switch 3 in the clockwise direction and thus This rocker switch tilts around its tilting bearing. Now contacts 9 and 7 open when de-energized. The circuit is now bipolar ge opens, and thus the starting position of FIG. 1 is reached.

In the desired manner, this switch achieves a distribution of the load or contact erosion when switching on at the contact pair 7 , 9 and when switching off at the contact pair 8 , 10 .

Insofar as there are similarities, the same reference numbers were used in the second exemplary embodiment according to FIGS . 5 to 8 as in the first variant according to FIGS . 1 to 4.

A fundamental difference between the two embodiments (FIGS. 1 through 4 and FIGS. 5 to 8) is that the first switching cam 16 of FIG. 5 second on a to 8 at a first slide member 29 and the second switching cam 15 sliding element 30 located. In this exemplary embodiment, both sliding elements lie directly against one another or are at least relatively close to one another. Each can be moved back and forth in the sense of double arrow 1 . The displacement movement in turn results from an actuation of the actuator 2 in the direction of the arrow 27 or in the opposite direction 28 .

The actuator 2 has a lateral extension 31 with which it engages between the two driving surfaces 24 and 25 of the sliding element 30 . In analogy to the first variant, the lost motion path 22 results from a distance between the two driver surfaces 24 and 25 , minus the thickness of the second switching cam 15 , measured in the direction of the double arrow 1 .

Corresponding driver surfaces 32 and 33 are provided on the first sliding element 29 . Their distance corresponds to that of the right side projection 34 of the actuator 2 in FIGS. 5 to 8 or slightly exceeds its thickness, measured in the displacement direction 1 , as provided in the exemplary embodiment. This makes assembly easier, but also results in a minimal lost motion on the right side of the switch, which is greatly exaggerated in the drawing. In reality, it's just a common game. In particular, from FIG. 8 it can be seen that the actuator 2 is provided with a thickened head to form the two side lugs 31 and 34 which are opposite or adjoining one another.

In analogy to the actuation of the first exemplary embodiment according to FIGS. 1 to 4, also in this second variant, starting from the position according to FIG. 5, the right first sliding element 29 is first shifted from bottom to top ( FIGS. 5 and 6), which leads to a tilting of the shift lever 4 in a clockwise direction and thus to a closing of the contacts 9 and 10 . No current is flowing and therefore there is no contact erosion. If the actuator 2 is pushed in the direction of the arrow 27 , starting from FIG. 6, until the position according to FIG. 7 is reached, the rocker switch 3 tilts counterclockwise, as a result of which the contacts 7 and 9 close. However, because contacts 8 and 10 are already closed, this contact is made under load with corresponding contact erosion.

If, starting from the position shown in FIG. 7, the actuator 2 is pulled back again in the direction of arrow 28 or is pressed back by a spring, then the second sliding element 30 remains in the sliding position reached until the lateral extension 31 Has gone through backlash 22 . In the meantime, contacts 8 and 10 have been disconnected under load, which results in a corresponding contact erosion. The position shown in FIG. 8 is now reached. Further retraction of the actuator 2 in the direction of the arrow 28 finally leads to the contacts 7 and 9 opening, but not under load and thus also without contact erosion.

It is thus also achieved in this variant that when this switch with working contacts is switched on, the contact erosion takes place at the contact pair 7 and 9 , while when the circuit is opened, the contact erosion takes place at the contacts 8 and 10 .

The circuit diagram in FIG. 9 corresponds to the exemplary embodiments in FIGS. 1 to 8. In both cases, these are switches with work contacts, that is to say switches whose contacts are open in the rest position. Instead, however, the invention can also be applied to a two-pole electrical switch which is not an on-off switch but a changeover switch. A corresponding circuit diagram is shown in FIG. 10. In the two circuit diagrams, the movable and the fixed contacts are entered analogously to FIGS. 1 to 8. In addition, a consumer 35 is also shown in FIG. 9. When switch of FIG. 10, a second consumer is 36 to see. In the starting position of this switch, the consumer 36 is under current, while the consumer 35 receives current in the switch position of this switch. In addition to contacts 7 to 10 , contacts 37 and 38 are also shown in FIG. 10. In view of the detailed explanation of the two exemplary embodiments according to FIGS. 1 to 8, the circuit diagram according to FIG. 10 certainly does not require any special explanation of the mode of operation of this switch. It can be generally stated that when switching, for example, the contact pair 37 , 9 is disconnected under load, which is why no contact erosion then occurs in the contact pair 38 , 10 . Because in this case contacts 9 and 7 are closed first, this closing does not take place under load and therefore also without contact erosion. The latter takes place when the movable contact 10 strikes the fixed contact 8 of the second circuit with the consumer 35 . Analogously, the switch back to the drawn starting position according to FIG. 10 takes place with a corresponding distribution of the contact erosion over the contact groups 7 , 9 , 37 or 8 , 10 , 38 .

Claims (10)

1. An electrical switch for two-pole opening and closing a circuit with a displaceably mounted in a switch housing actuator (2) extending between two switching rockers (3, 4), in particular at the same height (19, 20) arranged tilting bearings (5, 6 ), where each rocker switch ( 3 , 4 ) carries a movable contact ( 9 , 10 ) cooperating with a mating contact ( 7 , 8 ; 37 , 38 ) and the two movable contacts in the switch-on or switch-off position or a switch position can be brought, characterized in that for the targeted minimal time-delayed opening or closing of the contact pairs ( 7 , 8 ; 8 , 9 ; 9 , 37 ; 10 , 38 ) between the actuator ( 2 ) and each rocker switch ( 3,4 ) Switching cams ( 15 , 16 ) is located and the two switching cams are coupled to one another via a lost motion path ( 22 ) which is effective in the actuating direction ( 1 ) such that, based on each of the two Actuator end position, when the actuator ( 2 ) is moved, the second switching cam ( 15 ) is only taken along when the first switching cam ( 16 ) has covered the lost motion distance ( 22 ), and that when the lost motion distance ( 22 ) is passed through, the first switching cam first ( 16 ) actuates its assigned rocker switch ( 4 ) and then, when pushed on, the second switching cam ( 15 ) actuates its assigned rocker switch ( 3 ). 2. Switch according to claim 1, characterized in that each tilt bearing ( 5 , 6 ) is electrically conductively connected to a switch connecting element. 3. Switch according to claim 1 or 2, characterized in that each movable contact ( 9 , 10 ) is attached to a resilient arm and this forms part of the rocker switch ( 3 , 4 ). 4. Switch according to claim 3, characterized in that each rocker switch ( 3 , 4 ) has an approximately U-shaped shape, with an inner U-leg ( 13 , 14 ) on the associated switching cam ( 15 , 16 ), while an outer U-leg carries the movable contact ( 9,10 ). 5. Switch according to one of the preceding claims, characterized in that each switching cam ( 15 , 16 ), mounted on a sliding element mounted in the switch housing ( 29 , 30 ), in particular is formed, and the two sliding elements can be displaced by means of a common actuator ( 2 ) . 6. Switch according to claim 5, characterized in that the two sliding elements ( 29 , 30 ) are directly adjacent to each other and the actuator ( 2 ) with the sliding element ( 29 ) of the first switching cam ( 16 ), seen in the direction of displacement ( 1 ), without play or at most coupled with little play, while the actuator ( 2 ) engages with a lateral shoulder ( 31 ) between two driver surfaces ( 24 , 25 ) of the sliding element ( 30 ) of the second switching cam ( 15 ), the distance between which is the lost motion distance ( 22 ), minus the thickness of the approach ( 31 ). 7. Switch according to one of claims 1 to 4, characterized in that the first switching cam ( 16 ), connected to the actuator ( 2 ), in particular is integrally formed thereon and the second switching cam ( 15 ) is located on a sliding element ( 21 ), which is mounted displaceably on the actuator ( 2 ) by the amount of the lost motion distance ( 22 ). 8. Switch according to claim 7, characterized in that the sliding element ( 21 ) is made in one piece with the second switching cam ( 15 ). 9. Switch according to claim 7 or 8, characterized in that the actuator ( 2 ) has two driving surfaces ( 24 , 25 ) arranged one behind the other in the direction of displacement ( 1 ), between which the second switching cam ( 15 ) is located and the distance of the lost motion distance ( 22 ), minus the thickness of the second switching cam ( 15 ). 10. Switch according to at least one of the preceding claims, characterized in that in the starting position of the actuator ( 2 ) the contact points or lines ( 17 , 18 ) of the two switching cams ( 15 , 16 ) with their rocker switches ( 3 , 4 ) on this side a by the tilting bearing (5, 6) defined imaginary plane (19, 20) and the two fixed contacts (7, 8) and the movable contacts (9, 10) are located beyond this imaginary plane (19, 20) perpendicular to the common plane of movement of the two contact arms ( 3 , 4 ) with the movable contacts ( 9 , 10 ).