IL149239A

IL149239A - Switch with fuse unit

Info

Publication number: IL149239A
Application number: IL149239A
Authority: IL
Original assignee: Eti Elektroelement Dd
Priority date: 1999-10-30
Filing date: 2002-04-21
Publication date: 2006-12-10
Also published as: EP1224677A1; SK5592002A3; DE29919140U1; EP1224677B1; HUP0203858A2; WO2001033592A1; CZ20021398A3; CN1384969A; AU1543601A; CN1216389C; ES2211645T3; HRP20020374A2; ATE257273T1; DE50004945D1; SK287388B6; YU31802A; PL354603A1; DK1224677T3; PL192475B1; IL149239A0

Abstract

The invention relates to a switch, comprising a housing (10), a switch lever (18), mounted in the housing, which can be pivoted between an on-position and an off-position and a detachable fuse unit (40), which may be mounted in the housing (10). The invention is further characterised by a lock mechanism (58, 60), which senses the position of the fuse unit (40) and impedes the movement of the switch lever (18) into the on-position when the fuse unit (40) is not in the correct position.

Description

SWITCH WITH FUSE UNIT The Invention relates to a switch comprising a housing, a switch lever mounted to the housing and plvotable between an on-position and an off-position, and a fuse unit adapted to be detachably inserted into the housing.

The fuse unit of such a switch is formed for example by a melt fuse and has the purpose, to interrupt the current circuit that has been closed by means of the switch, when the current intensity exceeds, an admissible value. In known swlt- ches of this type, the fuse unit consists of a fuse insert formed as a cartridge and provided with electric contacts at its both ends, and a holder associated with the fuse insert. When the fuse is exchanged, the new fuse insert is placed into the holder and is then inserted into the switch housing by means of this holder, such that its electric contracts are clampingly held between contacts of the switch housing. Then, malfunctions may occur, when the fuse unit has not correctly been inserted into the housing.

It is an object of the invention to improve the functional reliability of such a switch.

For a switch of the type indicated above, this object is achieved by a lock mechanism which senses the position of the fuse unit and impedes the movement of the switch lever Into the on-position when the fuse unit is not in the correct position.

If the fuse unit has not correctly been Inserted into the housing and, accordingly, is not in the intended end position between the contacts of the switch housing, the lock mechanism prevents the switch lever from being pivoted into the on-position. Thus, the mistake can readily be recognised by a user who may then correct the position of the fuse unit.

Consequently, the switch can only be switched on when the fuse unit has been inserted correctly and its electric contacts correctly engage the corresponding counter-contacts of the switch housing. In this way, it can reliably be prevented that, due to the incorrect position of the fuse unit, there remains an arc gap between the contacts of the fuse unit and the counter-contacts and, as a result, an arc is generated when the switch is closed. In addition, it is assured that, when the switch is" closed, the fuse unit Is In its correct position and, consequently, no interruptions of the current due to contact falls of the faults unit may occur once the corresponding electric equipment has been put Into operation.

Useful details of the invention are Indicated in the dependant claims.

Preferably, the lock mechanism Is formed by a nose which is provided on the switch lever and, when the fuse unit Is Ln the correct position and the switch lever Is pivoted Into the on-position, engages into a recess that has been provided for this purpose in the holder of the fuse unit, and which, if the fuse unit has not been Inserted correctly, abuts at the holder and prevents the switch lever from being pivoted.

The fuse unit is preferably secured in the switch housing by means of a spring which biases a contact, that is movably held in the switch housing, against an electrode of the fuse insert and thereby also provides the necessary contact pressure. The recess for the nose of the switch lever is then preferably formed at the end of the fuse unit which is opposite to the end engaged by the spring, so that the fuse unit may not retreat and then return into the wrong position after the switch has been closed. Optionally, the arrangement can however be made such that the fuse unit is pushed by the nose of the switch lever into its correct position.

An embodiment example will now be explained in detail in conjunction with the drawing, in which: Figure 1 is a view of the switch, with the housing being open, ln a state in which the switch is partly open and the fuse unit Is Inserted correctly: Figure 2 shows the switch according to figure 1 in the closed state; and Figure 3 shows the switch according to figure 1 , when the fuse unit has been inserted wrongly.

The switch has a housing 10 which is made of an electrically Insulating resin, and, in a known manner, is formed as a clamping rail housing and Is to this end provided with a snap mechanism 12. shown at the lower edge In the drawing, for snap-fastening the switch to a clamping rail (not shown) of a fuse and distributor box or the like. Cable terminals 1 and 16 at opposite ends of the housing 10 serve for clamplngly securing connection cables which have not been shown and between which an electric contact can be established or interrupted by means of the switch.

A switch lever 18 is mounted in the housing 10 to be plvotable about an axis 20 and acts via a switching cam 22 and an articulated link 24 onto a contact bridge 26 that Is slidably guided between ribs formed at the housing 10. The cable terminal 14 Is electrically connected to a contact sheet 28 which forms an electric contact 30 opposed to the contact bridge 26. An Intermediate contact sheet 32 is held in the housing 10 such that its one end is flush with the contact sheet 28. but is separated therefrom by a substantial clearance, and another electric con- tact 34 of the intermediate contact sheet 32 is opposed to the contact bridge 26. The contact bridge 26 is biased towards the contacts 30 and 34 by a compression spring 36. but In the condition shown in figure 1 , It Is still held away from the contacts 30 and 34 by the link 24, so that the switch is not yet closed.

Connected to the other cable Lermlnal 16 is another contact sheet 38 which, together with the intermediate contact sheet 32, forms a clamping seat for a fuse unit 40. The fuse unit 40 has a generally U-shaped holder 42 Into which a fuse insert 44 can be placed such that electrodes 46 and 48 at opposite ends of the fuse insert are freely accessible.

The intermediate contact sheet 32 forms a rest for the holder 42 as well as a counter-contact for the electrode 46 of the fuse insert. The distal end of the intermediate contact sheet 32 Is supported at the housing 10 by a compression spring 50 such that the intermediate contact sheet is firmly pressed against the electrode 46 and thereby presses the electrode 48 provided at the opposite end of the fuse Insert 44 firmly against the contact sheet 38. The holder 42 is Inserted into the housing 10 in a slight tilting movement and has a locking tab 52 which is provided In the vicinity of the contact 48 and grips around a rib 54 of the housing and thereby secures the holder 42 in its position In the housing 10. The top end of the holder 42 forms a support 56 for the free end of the switch lever 18.

The switching cam 22 which Itself is rigidly connected to the switch lever 18 is formed on the side facing toward the fuse unit 40 with a nose 58. A recess 60 In the opposing outer wall of the holder 42 is associated with this nose 58.

Together with the compression spring 36, the switching cam 22 forms a dead- centre mechanism for the switch lever 18. In the condition shown in figure 1 , the switch lever 18 has already been pivoted so far to the right. In the direction towards its on-position, that the switching cam has exceeded the dead centre and Is tilted further towards the on-position by the link 24 which is engaged by the compression spring 36.

Figure 2 illustrates the condition in which the switch lever has completely been pivoted into the on-position and rests upon the support 56. In this condition, the contact bridge 26 is held in engagement with the contacts 30 and 3 by the compression spring 36, so that the cable terminals 14 and 16 are electrically connected to one another through the contact sheets 28, 32 and 38 and the fuse insert 44. Further, it can be seen in figure 2 that the nose 58 which is rigidly connected to the switch lever 18 Is received In the recess 60 of the holder 42 of the fuse unit.

When the switch lever 18 is completely pivoted to the left into its off-position, the fuse insert 44 can be withdrawn from the housing 10 by means of the holder 42. when fuse is to be exchanged. When a new fuse Insert 44 has been placed into the holder 42, the latter is once again placed against the Intermediate contact sheet 32 and hooked-in at the rib 54 with Its locking tab 52.

Figure 3 shows the switch in a condition in which the holder 52 has not been Inserted correctly. In this case, the locking tab 52 does not grip around the rib 54 but Is lnstably supported at the end of the rib 54. For this reason, the electrode 48 of the fuse insert 44 forms an arc gap with the contact sheet 38. Since, however, the holder 42 assumes a somewhat tilted position in this state, it is upper edge, on the left side In figure 3, interferes with the path of movement of the nose 58 of the switch lever 18. If one attempts to pivot the switch lever 18 into the on-position, the nose 18 will therefore engage the upper edge of the hol-der 42 above the recess 60, so that the switch lever 18 cannot be tilted further, and, as a consequence, the contact bridge 28 cannot be moved into the closed position. Only when the position of the holder 42 has been corrected can the nose 58 enter again Into the recess 60. so that the switch can be cloeed.

Claims

149,239/2 WHAT IS CLAIMED IS:

1. A switch with an enclosure, an actuating arm, which is mounted at the enclosure and can be pivoted between an on position and an off position, a fuse unit, which can be releasably inserted in the enclosure and comprises a holder, which accommodates the actual fuse link, can be inserted in the enclosure in a tilting movement and can be fixed by way of a locking lug to a rib of the enclosure, and with a blocking mechanism, which senses the position of the fuse unit and prevents the actuating arm from pivoting into the on position when the fuse unit is not in the correct position, characterised in that the blocking meehanism is formed by a lug, which is rigidly disposed at the actuating arm and only enters a recess of the holder when the holder is correctly hooked in by way of the locking lug and otherwise strikes against the end of the holder which is adjacent to the locking lug.

2. The switch according to claim 1, characterised in that the fuse unit is retained in clamping fashion in the enclosure and is acted upon at one end indirectly or directly by a spring, and that the blocking mechanism is disposed at the end of the fuse unit which is opposite the spring.

3. The switch according to claim 2, characterised in that the fuse unit is retained in the enclosure so as to be oriented approximately at a right angle to the pivot axis of the actuating arm, that the actuating arm is located in a position lying above one end of the fuse unit in the on position, and that the lug of the blocking mechanism is formed at a cam which is rigidly connected to the actuating arm.

4. The switch according to any one of the preceding claims, characterised in that the fuse link is provided with electrodes at its opposite ends and is retained in clamping fashion between contact plates. 6 149,239/2

5. A switch according to claim 1, substantially as hereinbefore described and with reference to the accompanying drawings. for the Applicant: WOLFF, BREGMAN AND GOLLER