Title of Invention

LOW VOLTAGE CIRCUIT BREAKER

Abstract

A low-voltage circuit-breaker contains a contact arrangement (19), a drive apparatus (20) for actuating the contact arrangement (19) and also a switching shaft (2) , which serves to transmit a drive force from the drive apparatus (20) to the contact arrangement (19). A bearing arrangement for the switching shaft (2) has at least one bearing body (1) which is connected to a pole assembly (4) accommodating the contact arrangement (19). As a result of this, a unit is formed which can be tested independently of the other assemblies of the circuit-breaker. In the case of multipole: circuit-breakers, a common switching shaft (2) is used for all of the contact arrangements (19) and/or pole assemblies (4), which common switching shaft is mounted approximately centrally in a main bearing body (1) and near to the ends in auxiliary bearing bodies (8, 9).

Full Text

1591/cl98 Description Low-voltage circuit-breaker having a switching shaft The invention relates to a low-voltage circuit- breaker having a switching shaft a contact arrangement, and a drive apparatus for actuating the contact arrangement, and a switching shaft for transmitting a drive force from the drive apparatus to the contact arrangement, and a bearing arrangement that accommodates the switching shaft. Low-voltage circuit-breakers comprise a plurality of assemblies which are matched to the various sub-objectives and are connected to one another in the course of production of the circuit-breakers. The largest assemblies, or units, in this case form the switching poles, that is to say the contact systems, comprising stationary and moveable switching contacts, with their supporting insulation and components for connection to a drive apparatus which is common to a plurality of such switching poles. In this case, the movement sequences provided by the drive apparatus are transmitted via a fixedly mounted switching shaft to all of the contact systems that are present. Hitherto the switching shaft has been handled constructionally as part of the drive apparatus. An example of this is shown in DE-C 44 16 08 8, which shows a lever arrangement for transmitting a drive force with a conventional structure. This arrangement has parallel supporting plates and bounding parts which are fastened thereto and by which the distance between the supporting plates is locally reduced to a suitable distance for guiding articulated levers. The joint bolts of the levers are guided in a sliding manner on the bounding parts. DE-C 4 4 16 0 90 shows a bearing arrangement for a switching shaft of a multipole electrical switching device having a supporting mechanism formed from parallel walls, which has shaft bearings with half- - 2 - shells. DE-A 42 27 352 illustrates a switching shaft which is common to the pole units formed from the switching chambers and is composed of shaft sections corresponding to the pole units. The pole units rest on a support which is dimensioned in accordance with the largest width of the pole units. Further illustrations of force transmission systems for the actuation of switching contacts are described in DE-C 28 35 879 and DE-A 27 26 489. All these designs described have proven to be thoroughly worthwhile for the production of the individual assemblies, but they have the disadvantage that functional testing is possible only in the fully assembled state of the switch. This means that from the mechanical point of view, a completely assembled switch is present. If a fault is then ascertained, the assembly which is defective cannot immediately be identified. Ultimately, the assemblies that have already been finally assembled have to be separated again in order to replace the defective assembly. Consequently, the invention is based on the object of facilitating testing and reducing the time taken by rectifying faults. In particular, it is intended to test whether the path made available by the drive effects proper closing of the contact arrangements with the required contact force. According to the invention, this object is achieved by virtue of the fact that the bearing arrangement for the switching shaft has at least one bearing body connected to a pole assembly, which accommodates the contact arrangement. The "switching pole" assembly thereby becomes intrinsically fully functional and, consequently, can be tested in a simple manner before the switch is completely assembled. On the other hand, no disadvantages at all arise for the independent testability of the drive apparatus. According to a preferred embodiment of the invention, the switching shaft is integrated into the - 3 - "switching pole" assembly by the use of at least three bearing bodies, of which the central or middle main bearing body has additional elements known per se, in particular springs for providing a retaining force, end stops, a bouncing inhibiting device, and elements for taking up residual energy. This central main bearing body is advantageously connected to a wall of the pole assembly by a combination of positively locking and force-locking elements. That may expediently be two or more insertion feet in conjunction with corresponding accommodating pockets in the wall of the pole assembly and centring pins having an internal thread which align the central main bearing body relative to the wall of the pole assembly and relative to the drive apparatus. Near to its ends, the switching shaft is supported by two auxiliary bearing bodies which are expediently fastened in an identical or similar manner, but have no or only a portion of the additional functions mentioned. The production and assembly of the switching shaft can be facilitated by a subdivision of the switching shaft into two symmetrical portions Synchronous driving of the portions is ensured by a coupling bolt which passes through levers seated on both portions of the switching shaft. The advantage of the divided switching shaft is that the portions are supported in two respective bearing points. The nature of the bearing arrangement is thus determined statically and, consequently, can be designed with little play. A possible alignment error is compensated for with no influence on the friction ratios by the coupling. The main bearing body is provided with an abutment for retaining springs which is preferably integrally formed in one piece on the main bearing body. The retaining springs - may already be fitted before the mounting of the bearing arrangement on the main bearing body. The retaining springs are thereby accommodated in a space-saving manner and advantageously act after the manner of a dead centre or - 4 - beyond dead centre system on the switching shaft lever. That reduces the feedback effect on the main energy store of the switch drive. The invention is explained in more detail below using a preferred exemplary , embodiment which is illustrated in the accompanying figures Figure 1 diagrammatically shows the arrangement of the switching shaft in the "switching pole" assembly, in side view, with the contact arrangement closed. Figure 2 diagrammatically shows the arrangement according to Figure 1, with the contact arrangement open. Figure 3 diagrammatically shows a front view of the arrangement according to Figure 1. The arrangement of the central or middle main bearing body 1 with the switching shaft 2 is illustrated in Figures 1 and 2. This central main bearing body 1 is connected to a wall 3 of the pole assembly 4 by two insertion feet 5 in conjunction with corresponding accommodating pockets 6 in the wall 3 of the pole assembly 4 and centring pins 7 having an internal thread which align the main bearing body 1 relative to the wall 3 of the pole assembly 4 and relative to the drive apparatus 20 indicated in Figure 1. As is shown in Figure 3, the switching shaft 2 is supported near its ends by two auxiliary bearing bodies 8 and 9, which are likewise fastened by means of insertion feet 10 and 11. As is shown in more detail in Figure 3, the switching shaft 2 is designed in the form of two symmetrical portions 2a and 2b, which are provided, at their coupling ends, with levers 13 and 14 connected to one another by a coupling bolt 12, which passes through these levers 13 and 14 seated on the two portions 2a and 2b of the switching shaft 2. The main bearing body 1 is provided with an abutment 15 for the retaining springs 16 which is integrally formed in one piece on the main bearing body 1. Catch hooks 17 which can be - 5 - pivoted by means of the coupling bolt 12 are arranged on the levers 13 and 14, which hooks interlock behind catch elements 18 during the switch-off operation and thus prevent bouncing of the contact arrangement 19. The arrangement of a switching shaft 2 as described is particularly suitable for multipole circuit-breakers, in which the pole assemblies 4, as are shown in Figures 1. and 2, are arranged next to one another and are jointly actuated by the switching shaft 2. Instead of single-pole pole assemblies, it is also possible to provide an interconnected three-pole, four-pole or multipole pole assembly. The advantages of the invention are that testing of the interaction between drive, switching shaft and switch pole is made possible prior to final assembly of the switch. If a fault is ascertained, then it is not necessary for the assemblies that have already been finally assembled to be separated again in order to replace the' defective assembly. The time required for rectifying faults is thus significantly reduced. This is advantageous particularly in the case of multipole circuit-breakers. WE CLAIM; 1. Low-voltage circuit-breaker having a switching shaft (2), a contact arrangement (19) and a drive apparatus (20) for actuating the contact arrangement (19); said switching shaft (2) for transmitting a drive force from the drive apparatus (20) to the contact arrangement (19); and a bearing arrangement that accommodates the switching shaft (2); characterized in that, the bearing arrangement for the switching shaft (2) has at least one bearing body (1) connected to a pole assembly (4) which accommodates the contact arrangement (19), 2. Low-voltage circuit-breaker according to claim 1 wherein the bearing arrangement comprises at least three bearing bodies connected in a positively locking and force-locking manner to a wall (3) of (he pole assembly (4),comprising a centrally arranged main bearing body (1), which has additional elements (16;17;18) known per se, and two auxiliary bearing bodies (8;9) near to the ends of the switching shaft (2), which have no or not all of the additional elements of the main bearing body(l). 3. Low-voltage circuit-breaker according to claim 2, wherein the main bearing body (1) has two or more insertion feet (5) for connection to corresponding accommodating pockets (6) in the wall (3) of the pole assembly (4) and centring pins (7) for alignment of the main bearing body (1). 4. Low-voltage circuit-breaker according to claim 2, wherein the auxiliary bearing bodies (8;9) each have one or more insertion feet (10;11) for connection to corresponding accommodating pockets (6) in the wall (3) of the pole assembly (4) and centring pins (7) for alignment of the auxiliary bearing bodies (8;9). 5. Low-voltage circuit-breaker according to one of claims 2 to 4, wherein the centring pins (7) are provided with an internal thread. - 7 - 6. Low-voltage circuit-breaker according to Claim 2, wherein the additional elements (16; 17; 18) known per se are end stops, a bouncing inhibiting device {17; 18), apparatuses for taking up residual energy and retaining springs (16), 7. Low-voltage circuit-breaker according to one of Claims 2 to 6, wherein the centrally arranged main bearing body (1) has an abutment (15) for the retaining springs (16), which act after the manner of a dead centre or beyond dead centre. 8. Low-voltage circuit-breaker according to Claim 7, wherein the abutment (15) is integrally formed in one piece on the main bearing body (1) . 9. Low-voltage circuit-breaker according to one of Claims 1 to 8, wherein the switching shaft (2) consists of two parts (2a; 2b) , which are provided with levers (13; 14) at their coupling ends. 10. Low-voltage circuit-breaker according to Claim 9, wherein the parts (2a; 2b) of the switching shaft {2) are of symmetrical design. 11. Low-voltage circuit-breaker according to Claims 9 and 10, characterized in that the parts (2a; 2b) of the switching shaft (2) are connected to one another for the purpose of ensuring synchronous actuation. 12. Low-voltage circuit-breaker according to Claims 9 to 11, wherein in order to connect the parts {2a; 2b) of the switching shaft (2), a coupling bolt (12) is provided which passes through the levers (13; 14) present on the parts (2a; 2b) of the shaft (2) . Dated this 4th day of SEPTEMBER, 1998. B, BSEN OF L.S. DAVAR A CO., APPLICANTS' ATTORNEY. A low-voltage circuit-breaker contains a contact arrangement (19), a drive apparatus (20) for actuating the contact arrangement (19) and also a switching shaft (2) , which serves to transmit a drive force from the drive apparatus (20) to the contact arrangement (19). A bearing arrangement for the switching shaft (2) has at least one bearing body (1) which is connected to a pole assembly (4) accommodating the contact arrangement (19). As a result of this, a unit is formed which can be tested independently of the other assemblies of the circuit-breaker. In the case of multipole: circuit-breakers, a common switching shaft (2) is used for all of the contact arrangements (19) and/or pole assemblies (4), which common switching shaft is mounted approximately centrally in a main bearing body (1) and near to the ends in auxiliary bearing bodies (8, 9).

Documents:

01591-cal-1998-abstract.pdf

01591-cal-1998-claims.pdf

01591-cal-1998-correspondence.pdf

01591-cal-1998-description(complete).pdf

01591-cal-1998-drawings.pdf

01591-cal-1998-form-1.pdf

01591-cal-1998-form-2.pdf

01591-cal-1998-form-3.pdf

01591-cal-1998-form-5.pdf

01591-cal-1998-g.p.a.pdf

01591-cal-1998-priority document others.pdf

01591-cal-1998-priority document.pdf

1591-CAL-1998-CORRESPONDENCE 1.1.pdf

1591-cal-1998-granted-abstract.pdf

1591-cal-1998-granted-claims.pdf

1591-cal-1998-granted-correspondence.pdf

1591-cal-1998-granted-description (complete).pdf

1591-cal-1998-granted-drawings.pdf

1591-cal-1998-granted-examination report.pdf

1591-cal-1998-granted-form 1.pdf

1591-cal-1998-granted-form 2.pdf

1591-cal-1998-granted-form 3.pdf

1591-cal-1998-granted-form 5.pdf

1591-cal-1998-granted-gpa.pdf

1591-cal-1998-granted-letter patent.pdf

1591-cal-1998-granted-priority document.pdf

1591-cal-1998-granted-reply to examination report.pdf

1591-cal-1998-granted-specification.pdf

1591-cal-1998-granted-translated copy of priority document.pdf

1591-CAL-1998-PA.pdf