Title of Invention

FORCE STORAGE DEVICE FOR A TAP CHANGER

Abstract The invention relates to a force storage device for a tap changer with a pull-up slide which can be drawn up and a switching slide which is lockable and after release abruptly follows the movement of the pull-up slide. The pull-up slide and switching, slide are each guided in a respective guide rod to be longitudinally displaceable; not only the pull-up slide, but also the switching slide each have a guide roller at one side and a guide profile at the opposite side, the guide roller of the pull-up slide being guided in the guide profile of the switching slide and vice versa.
Full Text

Force storage device for a tap changer
The invention relates to a force storage device for a tap changer. Such force storage , devices are known from DE-PS 19 56 369.
Tap changers serve for uninterrupted changeover between different winding taps of a tapped transformer and thus for voltage regulation. The actual load changeover must, in that case, happen as quickly as possible, for which reason tap changers and the load diverter switches thereof are usually provided with a force storage device. The force storage device is in that case pulled up by a continuously and slowly rotating drive shaft and biased, and abruptly liberates a kinetic energy after its subsequent release.
A force storage device of the category in question is known from DE-PS 19 56 369. This comprises a pull-up slide and a lockable tensioning slide; springs formed as compression springs are arranged between these two slides. The pull-up slide and the tensioning slide are provided with flanges and bear against one another by their inner sides in such a manner that the compression springs are biased between, respectively, a flange of the pull-up slide and a flange of the tensioning slide. The pull-up slide and tensioning slide are displaceably mounted on parallelly extending guide rods. The pull-up slide in that case is actuated by an eccentric disc at the drive shaft, i.e. moved relative to the tensioning slide in the direction thereof. The compression springs disposed therebetween are thereby biased. When the pull-up slide has reached its end position, i.e. the springs are biased to a maximum extent, the locking of the tensioning slide is cancelled and this executes a rapid movement. This rapid longitudinal movement is converted by way of a roller pin, which is guided in a groove of the tensioning slide, into an equally rapid rotational movement of a switching crank, i.e. a switching shaft, which in turn actuates the load diverter switch.
A quite similar further force storage device, which is equipped with additional means for more reliable switching even when it is cold, is known from DE-PS 28 06 282.
Finally, there is known from DE-PS 39 19 596 a force storage device in which the^. eccentric at the drive shaft and the compression springs for energy storage lie in substantially the same horizontal plane in order to avoid an asymmetrical action of force.

However, all these known force storage devices have a number of disadvantages. In the first instance, they are of relatively complicated construction and consist of numerous individual components. In particular, the longitudinal guidance of the longitudinally , displaceable pull-up slide and tensioning slide at both sides by means of parallelly disposed guide rods imposes high and extreme demands on accuracy, and these demands are not only on the parallelism and the adherence to dimensions of the guide rods themselves, but also on the mounting of the two slides on these guide rods. Moreover, conversion of the direction of movement takes place twice in the case of the known force storage devices; a rotational movement of the drive shaft is converted into a longitudinal movement of the force storage device and the longitudinal movement thereof is converted back, after release, into a rotational movement of the switching shaft for actuation of the tap changer. This is complicated and moreover unsuitable and superfluous for tap changers and the load diverter switches thereof, which are in any case linearly movable. In addition, it is to be noted that the known force storage devices are conceived for operation in the switching oil of the tap changer. In that connection it has to be realised that the known tap changers are usually filled with oil, wherein the switching oil in the interior not only acts as an insulating medium, but also has a lubricating function with respect to the moved mechanical components. In more recent times, however, tap changers have also become known which operate with air or gas as insulating medium and in which, therefore, lubrication in this manner is not possible. The described longitudinal guides and mountings, which are required to be highly accurate, according to the state of the art are unsuitable for such applications.
The object of the invention is indicate a force storage device of the category stated in the introduction, which is of simple construction, consists of components which are as few in number as possible and are simple to produce, and also operates safely and reliably with air or gas.
This object is met by a force storage device with the features of the first patent claim. The subclaims relate to particularly advantageous developments of the invention.
Of particular advantage with the force storage device according to the invention is, in the ^ first instance, the substantially simplified mechanical construction of the entire subassembly. The core elements of this force storage device are only three flat components, namely a base plate, the pull-up slide and a switching slide - corresponding

with the tensioning slide of the state of the art - which can all be constructed in particularly advantageous manner as simple sheet metal parts. The requisite abutments, against which the springs are supported, are formed in simple manner as bent-over sheet metal \ tongues or straps directly at the relevant components. A further advantage of the force storage device according to the invention is that both the pull-up slide and the tensioning slide are guided in each instance only at one side at fixed guide rods and otherwise are supported and guided against one another. Compensation for tolerances is thereby possible in simple manner. Moreover, the entire arrangement does not impose any particular demands on lubrication. Finally, in this force storage device the longitudinal movement of the tensioning slide is taken off in quite uncomplicated manner by a switch coupling directly as a movement for actuation of the load diverter switch or tap changer.
The invention will be explained in more detail in the following by reference to drawings, in which:
Fig. 1 shows a force storage device according to the invention in perspective
illustration,
Fig. 2 shows a base plate of this force storage device by itself, in particular a)
from above and b) from below.
Fig. 3 shows a pull-up slide of this force storage device by itself, in particular
again a) from above and b) from below, and
Fig. 4 shows a switching slide of this force storage device by itself, in particular
similarly a) from above and b) frothy below.
Before the construction of the force storage device according to the invention is described in detail, it may be noted that in Fig. 1, which shows the complete management, not all details are provided with reference numerals, so as not to adversely influence the clarity and ease of understanding of the illustration. However, all subsequently mentioned reference symbols are found without exception in Figures 2 to 4, i.e. the corresponding ^ partial illustrations.

The force storage device according to the invention consists of three main subassemblies, namely a base plate 1, a pull-up slide 7 and a switching slide 14. The switching slide 14 in that case con-responds with the component termed tensioning slide in the state of the art.
The base plate 1 consists of a thin material, for example sheet steel 1. Straps 1.1 and 1.2 or 1.5 and 1.6, which are bent over in pairs, are respectively fumed at two opposite sides. The associated straps 1.1 and 1.2 each have a respective receiving bore 1.3 or 1.4; equally, the associated straps 1.5 and 1.6 each have a respective receiving bore 1.7 or 1.8. These receiving bores each serve for reception of a respective guide rod 5 or 6 in such a manner that the two guide rods 5 and 6 extend parallel to one another, but at different heights, longitudinally through the entire base plate 1. The longitudinal direction of the individual components in the sense of this description is represented in the figures in each case by a double arrow. The guide rods 5 and 6 are closed at the ends by respective locks 5.1, 5.2 or 6.1, 6.2. The function of these guide rods 5 and 6 will be described in more detail later. In addition, a respective bearing protrusion 1.9 or 1.10, which in turn is bent over, is fomied at each strap of one pair of integrally formed straps 1.5 and 1.6. This bearing protrusion 1.9 or 1.10 has a respective bearing point 1.11 or 1.12, in which a respective latching lever 3 or 4 is pivotably mounted. Each of the two latching levers 3 and 4 has at its other free end a roller pin 3.1 or 4.1 at which a respective actuating roller 3.2 or 4.2 is arranged. The function of the actuating rollers 3.2 and 4.2 is explained in more detail later. Arranged between each of the latching levers 3 and 4 and the base plate 1 is a respective spring 3.3 or 4.3 which is supported against a spring receptacle 1.13 or 1.14 and thereby guided. Each of the two latching levers 3 and 4 has a special region which is constructed as an actuating path 3.4 or 4.4 and at which a respective release roller 7.13 or 7.14, which will be explained in detail more later, can engage and can thus deflect the respective latching lever 3 or 4 out of its rest position. The entire base plate can be fastened to further components of the tap changer, to which the force storage device construction ally belongs, by screws 1.15, which are represented only schematically. A drive shaft spigot 2 is led from the underside through the base plate 1 to the upper side thereof. Disposed at that location on the drive shaft spigot 2 is a drive crank 2.1 with an eccentrically acting drive roller 2.2 disposed thereon. This subassembly is fixedly connected with the base plate by a screw-mounted bearing 2.3.
A pull-up slide 7, which is constructed to be longitudinally displaceable and which is to be explained in more detail in the following, is arranged above the base plate 1. The pull-up

slide 7 has at its side surfaces, as seen in the direction of movement, an integrally formed and upwardly bent-over strap 7.1 to which a guide roller 7.2 is fastened by means of a fastening screw 7.3. A guide strap 7.4. which extends over the entire length and has a , guide profile 7.5 extending in longitudinal direction, i.e. in movement direction, is integrally formed at the opposite side. This direction is, as already explained further above, illustrated by a double arrow. In addition, mutually opposite fastening straps 7.6 and 7.7 are arranged at the ends of the pull-up slide 7 and, moreover, a respective strap acting as an abutment 7.8 or 7.9 is integrally formed in opposite position. Furthermore, a respective further abutment 7.10 or 7.17 is formed at each of the fastening straps 7.6 and 7.7. In other words, two abutments are disposed at each end: 7.8 and 7.10 at one end and 7.9 and 7.17 at the other end. Inserted at both ends in the pull-up slide are spring supports 11 and 12, which are supported against the above-described abutments 7.8 and 7.10 at one end and 7.9 and 7.17 at the other end. The abutment 7.17 is drawn only schematically in Fig. 3; it is constructed in the same manner as the abutment 7.10 and integrally formed at the fastening strap 7.7. Compression springs 13 are disposed between the spring supports 11 and 12. One of them is guided by a spring guide rod 10, the spring guide rod 10 being fastened at both ends to the fastening straps 7.6 and 7.7. Disposed at the underside of the pull-up slide 7 are further, downwardly directed straps 7.11 and 7.12, at each of which a respective release roller 7.13 or 7.14, the function of which is explained in more detail further below, is arranged by means of a respective fastening screw 7.15 or 7.16. At one side the entire pull-up slide 7 is guided to be longitudinally displaceable on the one guide rod 5 via two longitudinal guides 8 and 9, which are each screw-mounted by means of a respective fastening screw 8.1 or 9.1. The already-mentioned guide strap 7.4 with the guide profile 7.5 is disposed on the side opposite this guide rod 5. The pull-up slide 7 has at the underside a transverse guide 7.18 in which the drive roller 2.2 of the drive crank 2.1 is guided in the mounted state.
A further component - the switching slide 14 - is guided in the guide profile 7.5 and arranged thereabove. This switching slide 14 has, in turn, at one of its ends a strap 14.1 which is bent over downwardly and cames a guide roller 14.2, which is screw-mounted by means of a fastening screw 14.3. This guide roller 14.2 runs in the already-mentioned guide profile 7.5 of the pull-up slide. This strap 14.1 additionally comprises lateral locking ^ protrusions 14.4 and 14.5. Moreover, fastening straps 14.6 and 14.7. between which a further spring guide rod 17 is fastened, are provided at the two ends. Fastened to the side of the switching slide 14, at which the mentioned strap 14.1 is disposed, by means of

fastening screws 15.1 and 16.1 are further longitudinal guides 15 and 16, by means of which the switching slide 14 is similarly guided on the second guide rod 6 to be longitudinally displaceable. All longitudinal guides 15 and 16 are constructed as linear bearings, which are known as such. On the other side it has, entirely analogously to the pull-up slide 7, in turn a guide strap 14.8, which extends over the entire width, with a guide profile 14.9. The guide roller 7.2, already described further above, of the pull-up slide 7 runs in this guide profile 14.9. Here, too, respective abutments 14.10. 14.12 and 14.11, 14.13 are provided on the other side at both ends. Finally, brackets 14.14 to 14.17, between which a U-shaped support 18 is arranged, are disposed in pairs at the upper side. The connection between the switching slide 14 and the U-shaped support 18 is produced, by way of the above-described brackets 14.14 to 14.17, by means of damping means 20 to 23. A coupling element 19 is pivotably mounted at the U-shaped support 18 at a bearing point 18.1 and transmits the abrupt movement of the released switching slide to the respective switching means of the load diverter switch or tap changer, the switching means not being illustrated here.
It is evident from the explanations that the pull-up slide 7 and switching slide 14, which face one another by their open ends, are constructed to be interengaged. Not only the pull-up slide 7, but also the switching slide 14 is longitudinally guided at its outer side on a respective guide rod 5 or 6. Moreover, the two slides are mutually supported one against the other. This happens in the manner that each of the two slides has a guide profile 7.5 or 14.9 in which a guide roller 14.2 or 7.2 of the respective other slide runs. More specifically: the pull-up slide 7 has a guide roller 7.2 which runs in the guide profile 14.9 of the switching slide 14.9 and the switching slide 14 has a guide roller 14.2 which runs in the guide profile 7.5 of the pull-up slide 7. By virtue of this mechanism, the pull-up slide 7 and switching slide 14 are fixed in their position relative to one another and, in addition, are longitudinally displaceable individually and independently of one another.
The mode of operation of this force storage device is as follows: At the start of each actuation of the tap changer, the drive shaft, which comes from the motor drive and is connected with the drive shaft spigot 2, rotates through an angle of 180 degrees. The drive roller 2.2 thereby also rotates through this angle. The drive roller 2.2 runs in the transverse guide 7.18 of the pull-up slide 7 and thus displaces this by a certain amount in longitudinal direction. The compression springs 13 are thereby biased. The biasing takes place in the manner that the abutments on the end, which is rearward as seen in

movement direction, of the pull-up slide 7, thus the abutments 7.8 and 7.10 at one end or the abutments 7.9 and 7.17 at the other end, entrain the corresponding rear spring support 11 or 12, whilst at the same time the abutments 14.10 and 14.12 or 14.11 and 14.13, . which remain in their rest position, of the switching slide 14 fix the respective front spring support 11 or 12. The pull-up slide 7 is thus displaced in longitudinal direction, whilst the switching slide 14 remains in its former position. The switching slide 14 remains in its former position, because it is locked by the actuating rollers 3.2 and 4.2 of the described latching levers 3 and 4, which are supported against the corresponding locking protrusions 14.4 and 14.5. When the pull-up slide 7 reaches, after its longitudinal movement, the end position, one of the two release rollers 7.13 and 7.14 then runs - depending on the respective direction of movement - against the corresponding actuating path 3.4 or 4.4 of the corresponding latching lever 3 or 4 and presses this downwardly against the force of the respective spring 3.3 or 4.3. As a consequence, the respective actuating roller 3.2 or 4.2 comes out of engagement with the respective locking protrusion 14.4 or 14.5. The locking of the switching slide 14 is thus cancelled and the switching slide 14 abruptly follows the movement of the pull-up slide 7, the compression springs 13 are thereby relieved and the actuating rollers 3.2 and 4.2 go, in the new end position of the switching slide 14, back into engagement with the respective locking protrusions 14.4 and 14.5, the locking being produced again. In the next actuation of the tap changer the same process takes place in opposite direction. The pull-up slide 7 is thus always moved alternately to the left or to the right and the switching slide 14 then follows this movement each time after cancellation of its locking which fixes it at the outset. This abrupt longitudinal movement of the switching slide 14 is then transmitted by the coupling element 19 directly to the switching means to be linearly actuated.
Overall, a number of advantages result with the force storage device according to the invention by comparison with the state of the art. On the one hand, as already explained further above, virtually only three essential components, which can be produced in simple manner from sheet metal, are present: the base plate, the pull-up slide 7 and the switching slide 14. All necessary means for reception of guide rollers, for reception of the guide profiles and for the abutments against which the spring supports 11 and 12 are supported at both ends, are realised in entirely simple manner by bent, i.e. angled over, sheet metal straps. A further advantage consists in that notwithstanding relatively low demands on accuracy of the described components, an ideal compensation for tolerances is given. As described, both the pull-up slide 7 and the switching slides 14 are each directly

longitudinally guided only at a respective one of the two guide rods 5 and 6 and otherwise are mutually supported against one another and virtually guide themselves. Finally, a compact mode of construction is possible by virtue of the interleaved arrangement of the pull-up slide 7 and switching slide 14. It may also be noted that the force storage device according to the invention is particularly well suited for use in air or other gaseous Insulating media, as the described guides each consisting of a respective guide roller 7.2 or 14.2 in a respective guide profile 14.9 or 7.5 impose no special demands on, for instance, lubrication.




Patent Claims
1. Force storage device for a tap changer, wherein a pull-up slide, which is actuable , along a path by a drive shaft, and a lockable switching slide are provided, between which at least one compression spring is arranged, wherein two parallel guide rods are provided on which the pail-up slide and switching slide are guided to be movable independently of one another, wherein the at least one compression spring can be biased in such a manner by longitudinal movement of the pull-up slide relative to the switching slide that after release of the switching slide, which is locked until then, this abruptly follows the movement of the pull-up slide, characterised in that the pull-up slide (7) is guided only in one guide rod (5) and the switching slide (14) is guided only in the other guide rod (6), that the pull-up slide (7) has at one side a first guide roller (7.2) and at the opposite side a first guide profile (7.5) extending in the direction of movement, that the switching slide (14) similarly has at one side a second guide roller (14.2) and at the opposite side a second guide profile (14.9) extending in the direction of movement and that the first guide roller (7.2) corresponds with and is mechanically positively coupled to the second guide profile (14.9) and the second guide roller (14.2) corresponds with and is mechanically positively coupled to the first guide profile (7.5).
2. Force storage device according to claim 1, characterised in that the two guide rods (5, 6) are fastened to a separate base plate (1).
3. Force storage device according to claim 2, characterised in that the base plate (1) comprises straps (1.1, 1.2; 1.5, 1.6), which are bent over in pairs to each receive a respective one of the guide rods (5, 6).
4. Force storage device according to claim 2 or 3, characterised in that provided on the base plate (1) are two latching levers (3, 4) which are each deflectable out of the rest setting about a respective bearing point (1.11, 1.12) against the force of a respective spring (3.3, 3.4), that the switching slide (14) is lockable by the latching levers (3, 4) and that each of the latching levers (3, 4) is deflectable in such a manner by a respective release roller (7.13, 7.14) arranged at the pull-up slide (7) that the locking of the switching ^ slide (14) can be cancelled when the actuated pull-up slide (7) has reached its new end position.

5. Force storage device according to claim 4, characterised in that the respective release lever (7.13, 7.14) runs in a respective actuating path (3.4, 4.4) of the corresponding latching lever (3, 4).
6. Force storage device according to claim 4 or 5, characterised in that the locking of the switching slide (14) takes place in the manner that a lateral strap (14.1) is integrally formed thereat and has two locking protrusions (14.4, 14.5) in which an actuating roller (3.2, 4.2) of one of the two latching levers (3, 4) engages in dependence on the respective setting.
7. Force storage device according to one of the preceding claims, characterised in that abutments (7.8, 7.10; 7.9, 7.17) are arranged in pairs at each end at the pull-up slide (7) and similarly corresponding abutments (14.10, 14,12; 14.11, 14.13) are arranged in pairs at the switching slide (14), wherein spring supports (11, 12), against which at least one compression spring (13) is supported, are fixed between the abutments.
8. Force storage device according to claim 7, characterised in that the pull-up slide (7) and switching slide (14) are each constructed as a one-piece sheet metal part and that not only the abutments (7.8, 7.10; 7.9, 7.17) of the pull-up slide (7), but also the abutments (14.10, 14.12; 14.11, 14.13) of the switching slide (14) are constructed as bent-over straps.
9. Force storage device according to one of the preceding claims, characterised in that a coupling element (19) is pivoted to the switching slide (14) in such a manner that the abrupt longitudinal movement of the switching slide (14) can be transmitted directly to the tap switch to be actuated.
10. Force storage device according to claim 9, characterised in that the coupling element (19) is connected with the switching slide (14) by way of at least one damping means (20, 21, 22, 23) acting in the direction of movement.




Documents:

in-pct-2001-918-che-abstract.pdf

in-pct-2001-918-che-claims filed.pdf

in-pct-2001-918-che-claims granted.pdf

in-pct-2001-918-che-correspondnece-others.pdf

in-pct-2001-918-che-correspondnece-po.pdf

in-pct-2001-918-che-description(complete)filed.pdf

in-pct-2001-918-che-description(complete)granted.pdf

in-pct-2001-918-che-drawings.pdf

in-pct-2001-918-che-form 1.pdf

in-pct-2001-918-che-form 19.pdf

in-pct-2001-918-che-form 26.pdf

in-pct-2001-918-che-form 3.pdf

in-pct-2001-918-che-form 5.pdf

in-pct-2001-918-che-pct.pdf


Patent Number 210768
Indian Patent Application Number IN/PCT/2001/918/CHE
PG Journal Number 50/2007
Publication Date 14-Dec-2007
Grant Date 08-Oct-2007
Date of Filing 02-Jul-2001
Name of Patentee MASCHINENFABRIK REINHAUSEN GMBH
Applicant Address Falkensteinstrasse 8, D-93059 Regensburg,
Inventors:
# Inventor's Name Inventor's Address
1 DOHNAL, Dieter Stefan-Zweig-Strasse, 1 D-93138 Lappersdorf,
2 WREDE, Silke Iglauer-Strasse 47, D-93197 Zeitlarn,
3 HOEPFL, Klaus Burgermeister-Igl-Strasse, 12 D-93142 Maxhütte-Haidhof,
PCT International Classification Number H01H 9/00
PCT International Application Number PCT/EP1999/006804
PCT International Filing date 1999-09-14
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 198 55 860.0 1998-12-03 Germany