Linear selector

Abstract

The invention relates to a linear selector (1) for power-free preselection of tap contacts for a tapped transformer (100). The linear selector (1) according to the invention is cost-effective, simple and compactly constructed. The functions of a selector and a reverser are thus better connected. The linear selector (1) is constructed from a fine selector (2) and a reversing switch (3). The fine selector (2) and the reversing switch (3) are directly driven via a common gear unit (6).

Claims

1. A linear selector for power-free preselection of tap contacts of a tapped transformer comprising: a fine selector comprising uneven-numbered tap contacts in a first row and even-numbered tap contacts in a second row, a reversing switch having a switch shaft carrying a first contact fan and a second contact fan; and a transmission that directly actuates a single contact slide to contact the uneven-numbered tap contacts and the even-numbered tap contacts of the fine selector and the first and second contact fans on the switch shaft of the reversing switch.

2. The linear selector according to claim 1, wherein the transmission comprises: a Geneva wheel, a first bevel gear, a second bevel gear drivable by the first bevel gear, a transmission shaft fixedly connecting the Geneva wheel and the first bevel gear for joint rotation, and traction means carrying the second bevel gear.

3. The linear selector according to claim 2, wherein the Geneva wheel consists of a Maltese cross that is fixedly seated against relative rotation on a disk that carries at the circumference at a side remote from the Maltese cross a cam that co-operates with a groove of a fork of the switch shaft of the first contact fan and the second contact fan of the reversing switch.

4. The linear selector according to claim 3, wherein the switch shaft is pivoted by the cam on engagement in the groove of the fork of the switch shaft of the first contact fan and the second contact fan of the reversing switch.

5. The linear selector according to claim 2, further comprising: a continuously rotating driver that carries a plurality of rollers that so co-operate with the Maltese cross of the Geneva wheel such that a stepped movement of the Geneva wheel can be produced.

6. The linear selector according to claim 5, wherein the stepped movement of the Geneva wheel is transmissible by the transmission shaft to the first bevel gear and the second bevel gear and the traction means of the contact slide is linearly actuatable in steps by the traction means shaft.

7. The linear selector according to claim 6, wherein the traction means has an entraining pin that is so mechanically fixedly connected with the contact slide that the contact slide is movable vertically by the traction means.

8. The linear selector claim 1, wherein the contact slide has a first contact arm with a sliding contact pair and a second contact arm with a sliding contact pair such that an electrically conductive connection between the vertically spaced uneven-numbered tap contacts and a first diverter contact is producible by the first contact arm and the sliding contact pair thereof and an electrically conductive connection between the vertically spaced even-numbered tap contacts and a second diverter contact is producible by the second contact arm by the sliding contact pair thereof.

9. The linear selector according to claim 8, wherein an electrically conductive connection between one of the uneven-numbered tap contacts and the first diverter contact and/or between one of the even-numbered tap contacts and the second diverter contact is producible by stepped vertical movement of the contact slide via the traction means.

10. The linear selector according to claim 1, wherein the first contact fan and the second contact fan of the reversing switch are axially offset on the switch shaft, the first contact fan and the second contact fan each having a respective sliding contact pair, the selector further comprising: three reversing contacts in a horizontal plane of a first arcuate curve and associated with the first contact fan, and three reversing contacts in a horizontal plane of a second arcuate curve and associated with the second contact fan.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) These and other features and advantages of the various forms of embodiment disclosed here are more readily understandable with reference to the accompanying description and drawings, in which the same reference numerals throughout denote the same elements and in which:

(2) FIG. 1 is a perspective exploded view of a linear selector according to the invention;

(3) FIG. 2 is a large-scale sectional view of the contact slide of the linear selector;

(4) FIG. 3 is a perspective detail view of the transmission for connecting the contacts of the linear selector;

(5) FIGS. 4a-4c are diagrammatic views showing the switching sequence of the reversing switch; and

(6) FIG. 5 is a schematic view of the tapped transformer with the linear selector.

SPECIFIC DESCRIPTION OF THE INVENTION

(7) A linear selector 1 according to the invention having a fine selector 2 and a reversing switch 3 is depicted in FIG. 1. The fine selector 2 has two rows of vertically spaced tap contacts 4.sub.1, 4.sub.3, 4.sub.5, . . . ; 5.sub.0, 5.sub.2, 5.sub.4, . . . . A first row 40 carries the uneven-numbered tap contacts 4.sub.1, 4.sub.3, 4.sub.5, . . . and a second row 50 carries the even-numbered tap contacts 5.sub.0, 5.sub.2, 5.sub.4, . . . that are all inserted into a wall 37 of the linear selector 1. This wall 37 is constructed as a segment of a cylinder, but can also consist of a plurality of rods arranged in a semicircle. Those contacts that are connected with the uneven-numbered winding taps N.sub.1, N.sub.3, N.sub.5, . . . of a tapped transformer 100 are regarded as uneven-numbered tap contacts 4.sub.1, 4.sub.3, 4.sub.5, . . . . Those contacts that are connected with the even-numbered winding taps N.sub.0, N.sub.2, N.sub.4, . . . of the tapped transformer 100 are regarded as even-numbered tap contacts 5.sub.0, 5.sub.2, 5.sub.4, . . . (see FIG. 5). A transmission 6 is above the fine selector 2. In the illustration shown here it can be seen that the transmission 6 has a Geneva wheel 7, in which a Maltese cross 8 is seated on a disk 35 and connected therewith to be secure against relative rotation. The Maltese cross 8 is driven by a driver 9. The drive for the driver 9 is an electric motor (not illustrated here) that can be designed in the form of a three-phase alternating-current motor. In addition, the linear selector 1 has a first diverter contact 10 and a second diverter contact 11. The diverter contacts 10 and 11 run parallel to one another to a load changeover switch (not illustrated here).

(8) A further component of the fine selector 2 is a traction means 12 that is mechanically coupled with a contact slide 13. The traction means 12 can be a chain, a cogged belt or similar. A detailed depiction of the contact slide 13 is illustrated in section in FIG. 2.

(9) As can be seen in FIGS. 1 and 2, the contact slide 13 carries a first contact arm 14 and a second contact arm 15. Each contact arm 14, 15 has a sliding contact pair 16. The contact slide 13 can be moved up and down in a vertical direction V in the linear selector 1 by the traction means 12. When movement of the contact slide 13 takes place the first contact arm 14 contacts the uneven-numbered tap contacts 4.sub.1, 4.sub.3, 4.sub.5, . . . of the linear selector 1 by the sliding contact pair 16 and the second contact arm 15 contacts the even-numbered tap contacts 5.sub.0, 5.sub.2, 5.sub.4, . . . of the linear selector 1 by its sliding contact pair 16. As can be seen from FIG. 2, an entraining pin 18 by which the contact slide 13 is moved or entrained is at the traction means 12. In addition, the fine selector 2 has a guide 19 with the help of which the contact slide 13 is guided in the case of movement in vertical direction V.

(10) As can be further seen in FIG. 1, the linear selector 1 also consists of a reversing switch 3 that co-operates with the transmission 6 by a shaft 20. A first contact fan 21 and a second contact fan 22 are at the shaft 20. The first and second contact fans 21, 22 are mounted one above the other at a mutual spacing in axial direction on the shaft 20. The first contact fan 21 has a sliding contact pair 24 and the second contact fan 22 similarly has a sliding contact pair 24. The first contact fan 21 and the second contact fan 22 each have the shape of a segment of a circle, wherein each sliding contact pair 24 is provided at the respective segment curve. Three reversing contacts A, B, D are associated with the first contact fan 21 and are so arranged along an arcuate curve K.sub.BAD that they are contacted by the sliding contact pair 24 of the first contact fan 21 in the case of pivot movement thereof. Similarly, three reversing contacts B, C, D are associated with the second contact fan 22 and are so arranged along an arcuate curve K.sub.DCB that they are contacted by the sliding contact pair 24 of the second contact fan 22 in the case of pivot movement thereof. During operation of the linear selector 1 always at least two of the reversing contacts B, A, D and two of the reversing contacts D, C, B are electrically conductively connected together by the sliding contact pair 24 of the first contact fan 21 or the second contact fan 22. The reversing contacts A, B, C, C are similarly mounted in the wall 37.

(11) A detail view of the transmission 6 of the linear selector 1 is depicted in FIG. 3. The transmission 6 essentially consists of a Geneva wheel 7, a first bevel gear 30 and a second bevel gear 31. The Geneva wheel 7 is connected with the first bevel gear 30 by a connecting shaft 29 to be secure against relative rotation. The second bevel gear 31 is mechanically connected with the first bevel gear 30 by meshing engagement, wherein the second bevel gear 31 is seated on a traction means shaft 32. The Geneva wheel 7 consists of a Maltese cross 8 that is seated on a disk 35 to be secure against relative rotation. The disk 35 carries a cam 25 at the circumference at a side remote from the Maltese cross 8. The cam 25 co-operates with a groove 26 of a fork 27 of the shaft 20 of the first contact fan 21 and the second contact fan 22 of the reversing switch 3. The cam 25 temporarily engages in the groove 26 of the fork 27 in dependence on the rotational movement of the Geneva wheel 7. This takes place when the Geneva wheel 7 reaches a specific setting when rotating. During this process pivot movement of the fork 27 takes place and thereby pivot movement of the shaft 20 connected therewith, the pivot movement of which in turn results in pivoting of the first contact fan 21 and the second contact fan 22.

(12) As already mentioned, the driver 9 is continuously driven. Through the continuous rotational movement of the driver 9 the rollers 28 fastened thereto alternately come into engagement with grooves 38 of the Maltese cross 8. A stepped rotational movement of the Geneva wheel 7 arises due to the alternating engagement in the grooves 38 of the Maltese cross 8.

(13) The Geneva wheel 7 is connected with the first bevel gear 30 by the connecting shaft 29 to be secure against relative rotation, so that the stepped movement of the Geneva wheel 7 is transmitted to the first bevel gear 30. The first bevel gear 30 transmits the stepped movement to the second bevel gear 31. The second bevel gear 31 is in mechanical connection with a traction means shaft 32. Transmission of the stepped movement of the Geneva wheel 7 to the contact slide 13 takes place through a mechanically positive connection between the traction means 12 and the traction means shaft 32.

(14) During the preselection process an uneven-numbered tap contact 4.sub.1, 4.sub.3, 4.sub.5, . . . or an even-numbered tap contact 5.sub.0, 5.sub.2, 5.sub.4, . . . is always connected with one of the diverter contacts 10 or 11 with the help of the contact slide 13. In that case, the contact slide 13 travels in vertical direction from above to below or conversely depending on the rotational direction of the driver 9 and in that event connects the different uneven-numbered tap contacts 4.sub.1, 4.sub.3, 4.sub.5, . . . and/or the even-numbered tap contacts 5.sub.0, 5.sub.2, 5.sub.4, . . . with the respective diverter contact 10 or 11. The electrically conductive connection in that case arises on each occasion through the sliding contact pair 16 of the first contact arm 14 or second contact arm 15 that on the one hand touch or contact the uneven-numbered tap contacts 4.sub.1, 4.sub.3, 4.sub.5, . . . or the even-numbered tap contacts 5.sub.0, 5.sub.2, 5.sub.4, . . . and on the other hand the diverter contact 10, 11. This form of embodiment ensures that at least one electrically conductive connection is present between either an uneven-numbered tap contact 4.sub.1, 4.sub.3, 4.sub.5, . . . and the first diverter contact 10 or an even-numbered tap contact 5.sub.0, 5.sub.2, 5.sub.4, . . . and the second diverter contact 11.

(15) On travel of the uneven-numbered tap contacts 4.sub.1, 4.sub.3, 4.sub.5, . . . and the even-numbered tap contact 5.sub.0, 5.sub.2, 5.sub.4, . . . entirely from the top to entirely the bottom, i.e. from the transmission 6 to the reversing switch 3, the taps (windings) of the tapped transformer 100 are switched on and off depending on the respective wiring. On reaching a lower reversing point 33, the reversing switch 3 is actuated by the shaft 20 connected with the transmission 6 so that before the contact slide 13 continues its movement upwardly in the opposite direction the reversing switch 3 performs the switching and the taps of the tapped transformer 100 are switched on or off again.

(16) By contrast to a simple reverser that connects the regulating winding of a tapped transformer against or toward the regulating winding and in that case electrically separates it from the main winding the reversing switch 3 ensures by the first contact fan 21 and the second contact fan 22 a constant potential coupling of the regulating winding so that this is not separated from the main winding at any point in time. Reversing switches 3 of that kind with reversing contacts on two planes are also termed double reversers.

(17) As illustrated in FIGS. 4a-4c, the first contact fan 21 and the second contact fan 22 are pivoted from the starting position, in which the first contact fan 21 electrically conductively connects the first reversing contacts A and D together and the second contact fan 22 electrically conductively connects the first reversing contact B and C together. When the pivot movement takes place, as is illustrated in FIG. 4b the first contact fan 21 and the second contact fan 22 initially electrically conductively contact all reversing contacts B, A, D of the first arcuate curve K.sub.BAD or all reversing contacts D, C, B of the second arcuate curve K.sub.DCB and connect these together. Subsequently, the first contact fan 21 and the second contact fan 22 are pivoted further until the first contact fan 21 electrically conductively connects the reversing contacts A and B together and the second contact fan 22 electrically conductively connects the reversing contacts C and D together, as can be seen in FIG. 4c.