EP0048811B1 - Stepping switch - Google Patents

Description

The invention relates to tap changers with a plurality of switch planes which can be actuated by means of a one-piece common shaft or by means of a common shaft formed from mutually coupled shaft sections, with contact bridges which can be switched by the shaft or the shaft sections between fixed contacts of each switch level and are arranged on a switching rotor, with each switch level having two identical configurations , in the longitudinal direction of the shaft one behind the other arranged contact carrier plates with the fixed, arranged on a circular line contacts and associated externally arranged connections, which are connected to the contacts via lines on the contact carrier plates, whereby in a breakthrough of the contact carrier plates in an existing space between the contacts Switching rotor with contact bridges is rotatably supported by means of a hub part carrying the switching rotor in bearing eyes arranged on the contact carrier plates.

DE-A-1665161 shows switch levels suitable for such switches, each with a sealed housing, with a crank-shaped insulating body lying between the contact carrier plates. The contacts and their connecting parts are each arranged between the crank-shaped insulating body and one of the end-face contact carrier plates in corresponding depressions on the insulating body and the contact carrier plates. The contact carrier plates, the insulating body and the switching rotor are designed and arranged in such a way that each Schlater level has a separately sealed housing. This means that there is no possibility of internal ventilation of the sleep levels, so that any condensed water or the like which has formed cannot dry out.

The US-A-3 754 106 shows tap changers that can be assembled from several switch levels, in which each switch level has a separate sealed housing, which consists of two different end parts, a frame-like spacer arranged between them and a contact carrier plate for the arranged between the spacer and one of the end parts fixed contacts is established. The switching rotor carrying the contact bridges is rotatably mounted in the bearing eyes on the end face parts by means of pin parts arranged on it and forming the switch shaft.

Here, too, each switch level has a sealed housing, so that condensation water formation within the switch levels must be expected when the switch is used under strongly changing temperature conditions. Due to the sealed housing, drying out or ventilation is not possible.

The object of the invention is to provide a tap changer which, with a similarly simple structure to the known switch on the one hand - also be at a spaced switch level - permits washing of the circuit boards carrying the switch after assembly and on the other hand ventilation of the switch housing or the Switch housing parts after washing is carried out to prevent condensation and the like. to prevent during later operation of the circuit.

This object is achieved in that, in the case of a switch of the type specified at the outset, the lines are each embedded in the contact carrier plates and the contact carrier plates of each slat plane are placed directly next to one another with the formation of parting lines, the parting lines being sealed by means of sealing profiles which can be used and removed from the outside when the step switch is mounted that ring grooves are formed between the bearing eyes and the hub part towards the ends of the hub part, and that for sealing free end faces of contact carrier plates on these either end plates with openings that are coaxial with the hub part, or a closed end plate or a locking mechanism under pressure from into the ring grooves inserted sealing rings are placed.

The invention is based on the knowledge that sealed Schlater housings are generally necessary or desirable only with regard to cleaning or washing processes after the circuits carrying the Schlater have been completed. For the operation of the switch, however, a ventilated switch housing is generally advantageous, because then there is no risk of condensation and the like. consists. The invention leaves the view, which is set out in the documents mentioned at the outset, that sealing switch housings are advantageous under all circumstances.

An advantage of the design according to the invention is that the parts which are used according to the invention for the construction of the switch levels can also be used for the construction of such switches whose housings or housing parts permit ventilation of the interiors from the start, for example if the respective circuit boards are not washed is required. According to the invention, a modular system is thus created, the individual elements of which can be installed both for the construction of conventional switches and for the construction of slats with more or less large, sealed housing units with the possibility of subsequently removing the seal.

To avoid incorrect assembly, it is advantageous if the two or more contact carrier plates of one or more switch levels, which are arranged adjacent to one another between end plates, have complementary profile pieces on both sides, so that the contact carrier plates are non-rotatable relative to one another.

The complementary profile pieces are expediently at a distance from the outer edge of the contact carrier plates on their sides arranged surfaces so that the parting line between adjacent contact carrier plates can run straight.

In addition, the contact carrier plates preferably have bevelled or grooved edges on the parting lines to form a circumferential annular groove for receiving the seals accessible from the outside, so that the seals receive a secure fit.

In order to ensure that the seals rest on the flanks of the joints with approximately the same sealing pressure, the contact carrier plates on the joints preferably have an essentially circular cross section, so that the joints can be sealed by means of tensioned O-rings.

• Fig. 1 eine Vorderansicht einer Schalterebene entsprechend dem Pfeil I in Figur 2 in Achsrichtung der Schalterwelle,
• Fig. 2 ein Schnittbild dieser Schalterebene entsprechend der Schnittlinie 11-11 in Figur 1,
• Fig. 3 ein Schnittbild der Schlaterebene entsprechend der Schnittlinie 111-111 in Figur 2,
• Fig. 4 eine Draufsicht auf einen Stufenschalter mit teilweise im Abstand voneinander angeordneten Schalterebenen und
• Fig. 5 eine Seitenansicht, teilweise geschnitten, eines Schaltergehäuses mit von außen zugänglichen Dichtungen an Trennfugen zwischen Kontaktträgerplatten.

The separating joints provided between the contact carrier plates, which can be sealed by means of the seals accessible from the outside with the possibility of later lifting the seal, can also be arranged in a corresponding manner between one of the end plates and the adjacent contact carrier plate or between the locking mechanism and the adjacent contact carrier plate, so that removable seals can also be arranged here. The invention is explained below with reference to the drawing. It shows

• 1 is a front view of a switch level according to arrow I in Figure 2 in the axial direction of the switch shaft,
• 2 is a sectional view of this switch level according to section line 11-11 in Figure 1,
• 3 is a sectional view of the Schlater plane corresponding to the section line 111-111 in Figure 2,
• Fig. 4 is a plan view of a tap changer with switch levels partially arranged at a distance from one another
• Fig. 5 is a side view, partly in section, of a switch housing with externally accessible seals on joints between contact carrier plates.

The switch level S shown in FIGS. 1 to 3 has a housing 1 which essentially consists of disk-shaped contact carrier plates 2 and 2 'and end plates 3 which are braced against one another by means of hollow rivets 4' arranged laterally in bores 4 '.

In the contact carrier plates there is a longitudinal bore 5 with end regions 5 ′ which are widened like a ring step.

In each of the contact carrier plates 2 and 2 ', radially aligned contact tongues 6 are arranged within the longitudinal bore 5, which are connected via lines 7 embedded in the contact carrier plates to connections 8 arranged on the outside on the contact carrier plates, as can be seen from FIG.

From the end regions 5 ', angular bearing rings or eyes 9 are inserted into the longitudinal bore 5 at their two ends in profile, which have a step-like outer lateral surface corresponding to the ring step at the end regions 5' of the longitudinal bore 5. A non-rotatable arrangement of the bearing lugs 9 in the longitudinal bore 5 can be ensured by means of lugs (not shown) arranged on the lateral surface of the bearing lugs which engage in recesses at the end regions 5 '.

In the bearing eyes 9, a hub rotor 11, which is arranged between the contact tongues 6 of the two contact carrier plates 2 and 2 ', is rotatably supported by means of its hub part 10, which not shown carries contact bridges for the electrical connection of selected contact tongues 6 of two contact carrier plates, the respectively set connection being known in a known manner from that Position of the switching rotor depends.

To drive the switch rotor 11, its hub part 10 has a non-circular longitudinal bore 12 into which a switch shaft (not shown) with a corresponding out-of-roundness can be inserted. In order to facilitate the insertion of the switch shaft in the correct position, a notch mark 13 is attached to one end of the longitudinal bore 12.

For the axial bearing of the hub part 10, its end faces abut edges 14 of openings 15 which are arranged coaxially with the longitudinal bore 5 of the contact carrier plates 2 and 2 'in the end plates 3. In the area of the edge 14, the end plates 3 have an angular profile, such that the edge 14 engages around the bearing eyes 9 somewhat in the manner shown in FIG.

Between the bearing eyes 9, which are angular in profile, and the end parts of the hub part 10, to the edges 14 of the openings 15 in the end plates 3 there remain open annular grooves 16, in which sealing rings 17 are arranged, which lie under tension on the lateral surface of the hub part 12 and between them Edges 14 of the opening 15 of the end plates 3 and the bearing eyes 9 are clamped in with slight deformation by means of the base surface of the annular groove 16 formed thereby, in such a way that the ring slots 18 remaining between the front ends of the hub part 12 and the edge surfaces 14 of the opening 15 are sealed.

FIG. 4 shows how the switch levels shown in FIGS. 1 to 3 are combined with a detent mechanism 20 to form a tap changer.

The housing 1 of the switch planes S are partly arranged directly on the ratchet housing and partly at a distance therefrom, such that the switch shaft 21 is passed through the hub parts of the individual switch planes.

The latching mechanism 20 and the housings 1 of the switch planes S are held together by means of clamping bolts 22 and sleeve-shaped spacers 23, which are arranged between the two housings 1 arranged at a distance from one another. The clamping bolts 22 can be through the rivets 5 of the housing 1 or through additional bores 24 (see FIG. 2), which are arranged outside the sealed part of the housing.

In order to be able to put the switch planes together more easily, only depressions 25 visible in FIG. 1 and matching projections 26 can be arranged on the end plates, which cooperate with corresponding projections and depressions of an adjacent housing and ensure a non-rotatable connection between the housings.

Such projections and depressions can also be arranged on the end faces of the contact carrier plates 2 and 2 ', so that, on the one hand, the assembly of these contact carrier plates and, on the other hand, the placement of the end plates, which have such projections and depressions on their front and rear sides, on the contact carrier plates becomes.

FIG. 5 shows a switch in which the contact carrier plates 2 and 2 'are assembled with a detent mechanism 20 and an end plate 3' to form a tap changer with two switch levels S.

At this switch, the joints 27 between the contact carrier plates are sealed by means of O-rings 28 accessible from the outside, so that removal of these rings 28 is possible after washing the circuit carrying this switch. It is thereby achieved that an air exchange can take place between the interior of the housing and the outside atmosphere and any condensate formed in the interior of the housing evaporates. To securely fix the O-rings 28, the edges 29 of the joints 27 are chamfered to form a V-groove in which the O-rings are clamped.

Rectangular profile pieces 30 and corresponding rectangular cutouts 31 are arranged on the inner edge of the parting line 27, which ensure that the contact carrier plates 2 and 2 'are correctly positioned and their undrotatable connection.

Due to the arrangement of the profile pieces 30 and recesses 31 at a radial distance from the edges 29 of the contact carrier plates 2 and 2 ', the parting line 27, seen in a side view, runs in a straight line, so that simple sealing rings are sufficient for sealing.

For bracing the contact carrier plates 2 and 2 'as well as the end plate 3' and the locking mechanism 20, ears 32 having openings in which the clamping bolts 22 are arranged are arranged on these parts.

Claims (5)

1. A stepping switch comprising a plurality of switch tiers (S) which can be actuated by means of a one-piece common shaft (21) or by means of a common shaft formed by shaft elements which can be coupled together; contact bridges which are arranged on a switch rotor (11) which can be switched over between fixed contacts (6) of each switch tier (S) by the shaft (21) or by the shaft elements; wherein each switch tier (S) has two contact carrier plates (2, 2') of similar construction which are arranged behind one another in the longitudinal direction of the shaft with the fixed contacts (6) arranged on a circle, and associated externally disposed terminals (8) which are connected with the contacts (6) via lines (7) at the contact carrier plates (2, 2'); wherein the switch rotor (11) with the contact bridges is rotatably journalled in an opening of the contact carrier plates (2, 2') in a free space present between the contacts (6) in bearing eyes (9) arranged at the contact carrier plates (2, 2') by means of a hub part (10) which carries the switch rotor (11); characterized in that the lines (7) are each embedded in the contact carrier plates (2, 2'); in that the contact carrier plates (2, 2') of each switch tier are directly placed against one another forming parting joints (27), wherein the parting joints (27) are sealed by profiled seals (28) which can be set in place from the outside with the stepping switch assembled and removed again; in that ring grooves (16) which are respectively open towards the end faces of the hub part (10) are formed between the bearing eyes (9) and the hub part (10); and in that for sealing the free end faces of the contact carrier plates (2, 2') either end plates (3) having openings (15) coaxial with the hub part (10), or a closed end plate (3'), or a latch mechanism (20) are placed thereon while pressing on seal rings (17) laid into the ring grooves (16).

2. A stepping switch in accordance with claim 1, characterized in that two or more contact carrier plates (2, 2') of one or more switch tiers (S), which are arranged in contact with one another between end plates (3) are provided with complementary profiled elements (25, 26) at both sides so that the contact carrier plates (2, 2') are not rotatable relative to one another.

3. A stepping switch in accordance with claim 2, characterized in that the complementary profiled elements (25, 26) are arranged spaced from the outer edge of the contact carrier plates (2, 2') on their end faces.

4. A stepping switch in accordance with one of the claims 1 to 3, characterized in that the contact carrier plates (2, 2') have chamfered or grooved edges at the parting joints (27) in order to form a peripheral ring groove for accommodating the seals (28) accessible from the outside.

5. A stepping switch in accordance with one of the claims 1 to 4, characterized in that the contact carrier plates (2, 2') have a substantially circular cross-section at the parting joints (27) so that the parting joints (27) can be sealed by means of tensioned 0-rings (28).

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