EP1141986A1

EP1141986A1 - Disconnect switch

Info

Publication number: EP1141986A1
Application number: EP99963274A
Authority: EP
Inventors: Matthias Kroeker; Thomas HÄHNEL
Original assignee: Siemens Electromechanical Components GmbH and Co KG
Current assignee: TE Connectivity Solutions GmbH
Priority date: 1998-12-11
Filing date: 1999-12-01
Publication date: 2001-10-10
Anticipated expiration: 2019-12-01
Also published as: WO2000036622A1; EP1141986B1; DE59902702D1

Abstract

The invention relates to a disconnect switch for the load circuit of a battery of a motor vehicle. Said disconnect switch has a movable contact element (81, 126, 205) and a stationary contact element (64, 121, 204). The movable contact element is fixed in a locked position by a locking mechanism. A shape-memory alloy thermoelement (4, 104, 215) is used as a means for opening the locking mechanism, said element contracting itself upon being heated.

Description

description

Disconnector

The invention relates to a disconnector for the load circuit of a vehicle battery with the following features:

- a housing,

- an input conductor that can be connected to a pole terminal,

an output conductor that can be connected to the load circuit, a fixed and a movable contact for establishing a switching connection between the input conductor and the output conductor,

a contact carrier which carries a movable contact and can be switched between an open position and a closed position and is spring-biased into the open position,

- A locking mechanism that fixes the contact carrier in the closed position, and

- A means for opening the locking mechanism.

Such a circuit breaker has already been described in DE 197 01 933 Cl. This known disconnector has a contact rocker as a contact carrier, which is rotatably mounted in the housing and carries the movable contact indirectly via a contact spring acting as a lever arm. A tear spring is provided to return the contact rocker to the open position. The locking mechanism consists of an actuating arm and a pawl, the pawl locking the actuating arm on the contact rocker and the actuating arm biasing the contact rocker in its closed position.

An electromagnet system with an armature, which is coupled to the pawl, is used as a means for opening the locking mechanism. The magnetic system is energized to open, whereby the pawl unlocks the actuating arm and the contact rocker is brought into the open position by the tear spring. From the not yet published applications with the office ^¬ union file reference 198 32 573.8 and 197 41 919.4 additional battery disconnect switches are known in which a Elektromangetsystem is used to open the locking mechanism.

In the first-mentioned application, the locking mechanism consists of a toggle lever tensioning device, the armature of the electromagnet system acting on the central knee joint to open the locking mechanism.

In the second-mentioned application, the movable contact is arranged on a contact rocker and one as a locking mechanism between the contact rocker and a fixed bearing

Buckle spring clamped. In the switched-on state, the articulated spring is almost stretched and biases the contact rocker into its switched-on position. A magnet system is also used as the means for opening the locking mechanism, the armature of which acts on the central region of the buckling spring. If the locking mechanism is to be released, the electromagnet system is actuated and the armature moves the buckling spring past its dead center, so that it bends sideways and the contact rocker jumps into the open position.

In all of the above-mentioned disconnectors, the locking mechanism is released via the armature of an electromagnetic system. When used in a vehicle battery, the electromagnet system has the disadvantage that the armature of the electromagnet system can also move without excitation in the event of strong impacts and there is therefore a risk that the load circuit can be switched off unintentionally. Furthermore, the electromagnetic system takes up a high proportion of the weight and the total manufacturing costs of the disconnector. In motor vehicle construction in particular, efforts are being made to keep the weight as low as possible and to reduce the costs of small components due to the large number of items. From DE 32 32 466 AI a switching arrangement in motor vehicles is known in which a relay contact is designed as an overcurrent protection. The fuse consists of a fixed and a movable contact, the latter being arranged at the end of a cantilevered hot wire and pressed against the fixed contact by a spring. The spring is arcuate and fixed on one side with the hot wire in a holder and on the other side with its free end of the hot wire so that it presses the movable contact against the fixed contact. In the event of overcurrent, the hot wire heats up and contracts. Due to the contraction of the hot wire, the arcuate spring jumps into the opposite deflection and thereby opens the contact.

This type of overcurrent protection is unsuitable for a battery isolating switch, since the contacts are only pressed together by the spring force of the arc-shaped spring and, at high currents, such as those that occur when the engine is started, sparking and thus welding of the contacts would occur.

Starting from DE 197 01 933 Cl, the invention has for its object to provide a disconnect switch for the load circuit of a vehicle battery, which is inexpensive to manufacture, has a low weight and is less prone to shock than the electromagnetic systems.

This object is achieved in that the

Means for opening the locking mechanism is a thermocouple made of a shape memory alloy, which contracts when heated.

The thermocouple is connected to a sensor system which, for example in the event of a short circuit or a vehicle impact, applies current to it. The current warms up the thermocouple and opens by its contraction the United ^¬ latching mechanism.

The thermocouple is inexpensive to buy has a low weight and is therefore not stoßanfäl ^¬ lig.

It is only through the locking mechanism that it is possible to use the thermocouple in a disconnector for the load circuit of a vehicle battery. By fixing the movable contact in the closed position via the locking mechanism, the contacts are pressed together so strongly that even high currents, such as during the starting process, can flow.

A preferred locking mechanism has a tensioning element which in its extended position presses the movable contact against the fixed contact, the thermocouple acting on the tensioning element in such a way that the locking element opens out laterally to open the locking mechanism.

In one embodiment, the locking mechanism is designed as a toggle lever tensioning device, the tensioning element consisting of a first lever engaging the contact carrier and a second lever mounted in the housing, which are connected via a middle knee joint to form a toggle lever which, in an approximately stretched state, the contact carrier locked in its closed position.

In an alternative embodiment, the movable contact is arranged on a contact rocker which can be pivoted between a closed position and an open position and is biased in the open position by a tear spring. In this locking mechanism, a buckling spring is clamped as a tensioning element between the contact rocker and a fixed bearing, the central region of which acts on the thermocouple. The buckling spring points against the effective direction of the A preferred deflection on the thermocouple, this deflection by the thermocouple being limited to a dimension that is smaller than the change in length of the thermocouple. In the switched-on state, the almost elongated buckling spring biases the contact rocker into its switched-on position, while when the thermocouple responds, the buckling spring is moved past its dead center by the contraction of the thermocouple and is bent back into the off position by the pull-open spring while simultaneously moving the contact rocker.

The thermocouple advantageously engages via an actuating arm on the tensioning element designed as a toggle lever or as an articulated spring, in a preferred embodiment the actuating arm is also simultaneously designed as a return spring for the thermocouple.

In a further embodiment, the locking mechanism has a displaceable pin and a pivotable lever, the pin pressing the contact carrier with the movable contact into its closed position. The pivotable lever locks the pin in its closed position and is pivoted to open the isolating switch by the contraction of a thermocouple that engages this lever so that it releases the displaceable pin, whereupon the pretensioned contact carrier pivots into the open position and the Pen moves.

The unlocking force can be greatly reduced by the length of the sliding lever. If the contraction of the thermocouple is not sufficient to deflect the lever, it is advantageously deflected several times via deflection rollers, so that a longer length of the thermocouple and thus a greater change in length is available during the contraction. In this embodiment, the provision conveniently takes place of the thermocouple, i.e., the stretching of the Ther ^¬ moelements after contraction, by manually operable means and not as approximately shapes in the above-described execution, by a return spring, so that it is not in the contraction of the thermocouple the force of the return spring must be overcome and thus the entire contraction force is available.

The use of a thermocouple as a means for opening the locking mechanism has the advantage that it takes up much less space than the electromagnet system and thus the entire isolating switch can be arranged much more easily in a housing which is adapted to a pole terminal of the vehicle battery and saves the pole terminal itself . The space saving enables that additional components, such as. B. sensors or an electrical evaluation circuit can be arranged.

Further advantageous embodiments of the invention result from the subclaims.

The invention is explained in more detail below on the basis of exemplary embodiments illustrated in the drawings. Show it

1 shows the individual assemblies of a first embodiment of a disconnector designed according to the invention in a perspective view,

FIG. 2 shows the clamping mechanism assembly with thermocouple of the disconnector from FIG. 1 in a partially assembled state,

FIG. 3 shows the pole terminal assembly from FIG. 1 in the semi-assembled state,

FIG. 4 shows a plan view of the disconnector from FIG. 1, 5 shows the disconnector from FIG. 1 in the assembled state, but with the cover open,

FIG. 6 shows an alternative embodiment of a disconnector in a housing, only the base of which is shown,

FIG. 7 shows the disconnector from FIG. 6 in an exploded view,

FIG. 8 the clamping mechanism of the disconnector from FIG. 6 in an exploded view,

FIG. 9 shows the isolating switch from FIG. 6 in a top view with a simplified illustration in the area of the tensioning mechanism,

FIG. 10 shows a simplified sketch of the isolating switch of FIG. 6 after manual switch-off,

FIG. 11 shows a simplified sketch of the disconnector from FIG. 6 after automatic switch-off,

FIG. 12 shows a third embodiment of a disconnector in a schematic illustration,

13 shows a disconnector according to FIG. 12 in the open state and

FIG. 14 shows a part of the disconnector according to FIG. 12 in one position during the closing movement.

The disconnector shown in Figures 1 to 5 has a particularly simple structure. It is housed in a plastic housing 1, which is connected to a pole terminal assembly 2 is bound. From above in the plastic housing 1 an _S clamping assembly 3 is used, which interacts with an integrated thermocouple 4. In addition, an input conductor 5 and an output conductor 6 are inserted into the housing. Finally, the housing can 1 from the upper side with egg ^¬ nem lid 7 sealed (Figure 5).

The plastic housing 1 has a switching space 11 which is delimited by a base plate and side walls and which accommodates the functional parts of the disconnector. A space for receiving a pole terminal 21 is also recessed within the plastic housing by means of a curved partition wall 12. Since the cover 7 also has a corresponding recess 71, the closed and sealed housing with the isolating switch can be placed on the battery terminal with the pole terminal 21 in such a way that the pole terminal or a corresponding clamping screw 22 remain accessible from the outside. The pole terminal 21 interacts with a terminal shoe 27 which is riveted to a base plate 24 made of sheet metal. At the front end, this lies with a U-bend 25 on the pole clamp 21, where it is fixed via the clamping screw 22. The plastic housing 1 is placed on the base plate 24 and hot stamped, as a result of which the entire battery isolating switch is supported on both sides on the pole terminal. The base plate also has a continuous, vertical bend on the front for better transverse reinforcement.

A round pin 26 is cast onto the pole terminal shoe 27 and protrudes upward through the plastic housing 1 into the switch compartment 11. About this pin 26 is the

Battery power on the inside riveted input conductor 5 into the interior of the disconnector. This input conductor 5 consists of copper sheet and is bent in a U-shape. A leg 51 is plugged with a round hole 52 on the pin 26 and riveted. The round cross section of the pin 26 is sealed against the bottom of the housing 1 by an O-ring 53 in a wash-tight manner. On the leg 51 _d is input conductor 5 is also a ferrite ring 54 angeord ^¬ net in whose slot is a current sensor, preferably a Hall sensor, is inserted for monitoring of the battery current (not shown). This can be used, for example, to detect a short circuit that is used as a pulse to switch off the isolating switch. The current sensor can be soldered directly onto a (not shown) vertically installed circuit board. The electronics of such a circuit board are used, for example, to evaluate the short-circuit signal or to display the battery current detected by the current sensor for battery management.

A strand 10 for forwarding the current to a movable contact 81 is welded onto a leg of the input conductor 5 which is bent vertically. This movable contact 81 is fastened in a contact spring 8 which is clamped fixed to the housing. The strand 10 is two superimposed flat strands, which ensures good flexibility with large conductor cross sections in the actuation direction of the contact 81. The contact spring 8 is designed as a flat spring clamped on one side; the contact tearing force, the contact path and the contact force and the overstroke are applied via this spring; this part thus takes over the functions of a contact spring, a return spring and a contact rocker. The movable contact 81 is fastened approximately in the middle of the free spring length of the contact spring 8. The free spring end 82 is bent and formed into a hook 83 with which the contact spring is in engagement with the tensioning mechanism.

The tensioning mechanism assembly 3 consists of a toggle lever tensioning mechanism which is arranged on a carrier plate 31. The contact spring 8 is fastened to a tab 38 of the carrier plate 31 which is bent vertically upward. Furthermore, a square pin 39 is bent vertically upward from the support plate 31 and serves as a fixed pivot point for the clamping mechanism. The toggle lever of the tensioning mechanism is accordingly bent sheet metal parts, namely a first lever 32 and a second lever 33 are formed. On the first lever 32, two hinge pins 32a are cut free, which lie in the hinge holes of the U-shaped second toggle lever 33 and form a middle knee joint 37 with them. The second toggle lever 33 has further articulated holes 33b, with which this second lever is mounted on the square pin 39 mentioned. The first lever 32 has at its outer end, ie the end facing away from the middle knee joint, an eyelet-shaped recess 32b which engages with the hook-shaped end section 83 of the contact spring 8. In the articulated holes 33a and 33b of the second lever 33 and in the hook-shaped end section 83 of the contact spring, the respective hinge pins or the eyelet edge of the first lever rest with their edges when the knee joint is in a tensioned state. At the moment of release, when the middle knee joint is moved over the dead center, these act like a cutting edge bearing, as a result of which the bearing friction at the time of release is very low and requires only a small release force.

The thermocouple 4 is stretched in the form of a wire within the tensioning assembly between a suspension 41 and an actuating arm 42. The suspension 41 is a tab that projects perpendicular to the carrier plate 31 of the tensioning mechanism assembly. The actuating arm 42 is arranged on the opposite side of the toggle lever system on a tab 34 which is bent upwards perpendicularly to the carrier plate 31 and acts on the toggle lever system in the direction of buckling. In the tab 34 there is a recess 34a, through which the end of the cranked actuating arm acts on the knee joint 37 and through which the thermocouple is guided from the suspension 41 to the actuating arm 42. An additional bracket 43 is provided on the actuating arm 42 for fastening the thermocouple. The actuating arm 42 is resilient so that it always biases the thermocouple with a certain spring force. The tab 34 serves on the opposite ü _b succumbing side of the actuating arm 42 as a contact edge of the toggle lever clamping station in the tensioned state.

To trigger the tensioning mechanism, the thermocouple 4 is energized via two lines, not shown. As a result of the current, the thermocouple heats up and contracts. By contraction of the thermocouple, the end face of the cranked actuating arm 42 is pressed onto the second lever 33 at the level of the knee joint 37. The actuating arm 42 pushes the knee joint 37 past its dead center and is then completely pushed through due to the restoring force of the contact spring 8.

On the second lever 33, a switching lug 35 is bent upwards behind the frame-fixed swivel joint on the pin 39, which protrudes upwards through a hole 72 in the cover 7 or is accessible from the outside and thus serves for manual switching on and off. With the help of a screwdriver or a similar tool, the switching flag 35 can be flipped over in order to tension the toggle lever again and to close the contact spring again (manual reclosure after electrical triggering). Conversely, manual shutdown is also possible. The switching flag 35 is located in a recessed area in the cover, which can be sealed to the outside with a sealing plug 73. This plug 73 can also be sealed to prevent restarting when a short circuit persists; in this case it is ensured that not the user of a vehicle, but only the workshop personnel can switch the load circuit on again after the short circuit has been eliminated or the circuit has been checked.

The already mentioned output conductor 6 is attached to the outside of the housing 1. This is L-shaped, one leg 61 being fastened via a sawtooth contour in a corresponding pocket on the outside of the housing 1, while one leg 62 is hot stamped on the housing is fixed. This fixation absorbs the forces of a battery ^cable screwed to the output conductor 6 via a bolt 63; at the same time, the entire housing is stiffened by the L-shaped bend of the output conductor. A fixed contact 64 is fastened to the leg 62 from the inside and protrudes through a round opening 15 into the interior of the housing. The bushing 15 for this fixed contact 64 is sealed with an O-ring 16, so that the housing is closed in a wash-tight manner also at this point. The fixed contact 64 consists, for example, of a round copper part with a plated or welded contact material.

An additional emergency power connection 9 is also arranged on the housing 1 and connected to the input conductor 5. It is used to maintain emergency power circuits, for example for a hazard warning system, even after the disconnector has been triggered.

The function of the circuit breaker will be briefly described again below. In the idle state, the toggle lever is tensioned, the middle knee joint 37 being pushed out slightly beyond the dead center and the first lever 32 resting on the tab 34. This state is shown in Figure 4. The contact spring 8 is against its bias in the

Closed position pressed, the movable contact 81 lies on the fixed contact 6. When the thermocouple 4 is excited, the actuating arm 42 is pulled in the direction of the toggle lever system and, with its cranked end face, pushes the middle knee joint 37 over the dead center. Beyond the dead center position, the toggle lever is deflected with the now released contact and tear force of the contact spring 8, and the spring contact is opened. The contact spring 8 and the toggle lever 32, 33 then assume the dashed position shown in FIG. 4. By the _UE translation on the toggle clamping mechanism to the high contact and opening forces of the contact spring with a relatively small trigger forces and are thus connected with a thermocouple from ^¬; the proportion of frictional force is low. Switched on again manually the toggle lever must ge ^¬ be tensioned again, the lever 33 is moved by means of the switching plate 35, as described above, in the rest position.

The thermocouple 4 is stretched again by the restoring force of the resilient actuating arm 42.

An alternative embodiment of the invention is shown in FIGS. 6 to 11.

This battery isolating switch has a housing with a housing base 111 and a housing cap 112, which is adapted to the free space of a car battery in the area of a connection terminal. Accordingly, the housing has a recess 113 for the battery terminal 114, which has a known structure and can be clamped by means of a screw 115 on a battery pole, normally the positive pole of a vehicle battery. Via an extension 116, the battery terminal 114 is connected to an input conductor 117, which is made in the form of a rail from a highly conductive material and can be inserted in one piece with a base plate 117a into a switching space 119 formed by the housing base 111. An emergency power connection 117b is also formed on this input conductor, via which a supply of the safety-relevant functions, for example hazard warning lights, car telephones, etc., can be ensured with a low current requirement even after the battery isolating switch has responded. An output conductor 120 is arranged beneath the housing base 111, which is separated from the input conductor 117 by the insulating base 111 and in the present example has two connections 120a and 120b for load circuits. Furthermore, a contact carrier 120c is integrally attached to the output conductor. forms, which is guided through an opening in the housing base 111 into the control room and carries a fixed contact 121.

The base plate 117a is fastened to the housing base 111 by means of various screws 122 and insulating washers 123

(Figure 7) and also has a bent support plate 124 to which a strand 125 is welded, which is connected at its other end to a movable contact 126. This movable contact 126 is carried by a contact spring 127a, which is formed in one piece with a tear-open spring 127b by a flat form spring 127 and is fastened to a contact rocker 128. The contact rocker 128 is pivotally mounted on a journal 148. The tear spring 127b is biased towards a contact opening and its free end is supported on the support plate 124.

The actual release system is arranged in the control room 119. It consists of a thermocouple 104 in the form of a wire, which is stretched between a holder 129 and an actuating arm 130. The bracket 129 is designed as a pin which is attached to the base plate 117a via a flat bracket 134. The console 134 is preferably made of insulating material and has on one side a vertically raised contact wall 135 which extends essentially perpendicular to the thermocouple. A recess 135a is formed in the contact wall 135, through which the thermocouple passes. Between the contact wall 135 and the holder 129, a deflection 131 is arranged on the bracket 134, which is positioned such that the thermocouple 104 extends essentially perpendicularly through the recess 135a in the contact wall 135.

A guide pin 136 for a slide 137 and a bearing axis 138 for a switch button 139 are also fastened on the base plate 117a. The slide 137, which is bent in a U-shape from sheet metal, forms with its front edges a vertical notch 137a which is parallel to a corresponding notch 128a is opposite a rocker switch 128. Between the at ^¬ the notches 137a and 128a is a buckling spring 141 is longitudinally biased ^¬; it is pressed against the slide 137 by the force of the contact spring 127a and the tear spring 127b. The buckling spring 141 is arranged between the deflection 131 and the contact wall 135 and has an opening 141a, through which the thermocouple 104 is passed. The buckling spring 141 is slightly bent toward the abutment wall 135 and thus has a preferred deflection towards it, so that it resets in this direction after relaxation. The deflection in its preferred direction is only a few tenths of a millimeter in the middle section in the switch-on position shown in FIG. 9. In this almost extended state, the buckling spring can also transmit the force exerted by the slide 137 to the contact rocker 128 and keep the contact closed against the restoring force of the tear spring 127b. On the other hand, a slight contraction of the thermocouple is sufficient to pull the buckling spring 141 away from the abutment wall 135 and to move it past the dead center or its stretched length so that it can bend to the opposite side. The deflection is not limited on this opposite side.

The aforementioned rotary switch 139, which is mounted on the bearing axis 138, serves to actuate the slide. It has an eccentric driver pin 142 which slides along a driver edge 143 of the slide 137. The bearing axis 138 of the rotary switch is located in the extension of the elongated articulated spring 141, and the slide 137 is guided via an elongated hole 144 on the guide pin 136 parallel to the elongated articulated spring 141, while the driving edge 143 extends approximately perpendicularly thereto. However, this driving edge 143 is differently limited on both sides of the extension line to the buckling spring 141, so that there is an asymmetrical pivoting range. When the rotary switch 139 is turned clockwise, the driver pin 142 reaches the limit 143a according to FIGS. 10 and enables the slide 137 to be returned to a retracted switch-off position under the action of the tear spring 127b. During a pivoting movement of the rotary scarf ^¬ ters 139 counter-clockwise the driving pin 142 assumes a position at a boundary 143b of FIG 9, which is only slightly determined with respect to the dead center, the line formed by the by the buckling spring 141, the axis of rotation and 138, offset is, so that in this position the slide is locked in an advanced switch-on position.

To trip the isolating switch, the thermocouple 104 is supplied with a trip signal in the form of current, which in the example shown is generated by an electronic evaluation circuit 150 which is accommodated in an electronics room 151 of the housing 111, 112. It is connected to the thermocouple 104 via lines (not shown) and receives, for example, sensor signals from an acceleration sensor which is present in the vehicle for triggering an airbag. In addition, the disconnector can also be triggered in the event of an overload. For this purpose, a current sensor in the form of a Hall element 152 is accommodated in the housing of the disconnector, which measures the load current emitted by the battery using a ferrite ring 153 which surrounds the input conductor 117. If a specified one is exceeded

In the evaluation circuit 150, a corresponding excitation pulse is given to the thermocouple 104, which triggers the isolating switch.

The function of the battery disconnector according to the invention is explained with reference to FIGS. 9 to 11. Figure 9 shows the switched-on state. The rotary switch 139 is rotated counterclockwise so that the driver pin 142 abuts the limit 143b and locks the slide 137 in its switched-on position. According to the principle of a tilting tensioning mechanism, the buckling spring 141, which rests on the contact wall 135, is tensioned in the longitudinal direction, whereby it the clamping force from the _S chieber transferred to the contact rocker 128 by its almost stretched condition while the restoring forces of the Aufreißfeder 127b and the contact spring 127 overcomes. The contact rocker 128 is thus in the closed position, ie the movable contact 126 is in contact with the fixed contact 121 and closes the load circuit.

If the isolating switch is to be switched off manually, the rotary switch 139 is turned clockwise into the position according to FIG. 10, so that the driving pin 142 in the slide 137 rests on the limit 143a, the articulated spring 141 being subjected to the force of the tear spring 127b and the contact spring 127a 10 is shifted to the left and thereby pushes the slide 137 into its retracted switch-off position. The contact rocker 128 is then in its open position, abutting a stop pin 146. The state according to FIG. 10 shows the contact rocker 128 in an open position, i. that is, the movable contact 126 is separated from the fixed contact 121, so the load circuit is open. Thus, according to FIGS. 9 and 10, the load circuit can be switched on and off manually by turning the rotary switch 139 back and forth.

As soon as the thermocouple receives a trigger signal in the form of current from the electronic evaluation circuit 150, the thermocouple 104 contracts and pulls the articulated spring 141 over the dead center so that it can bend to the opposite side. Since it is not limited in its deflection on this side, it is bent by the tear spring 127b in connection with the contact spring 127a to such an extent that the contact rocker assumes its opening position on the stop pin 146. The buckling spring 141 is then bent as shown in FIG. 11. After termination of the current signal, the thermocouple 104 is stretched again by the actuating arm 130 designed as a return spring. The buckling spring 141 remains deflected, however, and the load circuit remains open, although the rotary switch 139 with the Driving pin 142 remains switched on and holds the slide 137 in its advanced switched-on position.

For _W iedereinschalten the load current, the contact rocker must be tightened again. This is done by resetting the slider 137 in the off position by rotating the scarf ^¬ ter 139 initially in the clockwise direction in figure is twisted 10 degrees. The buckling spring relaxes and rests against the contact wall 135 according to FIG. 10 in its preferred position. As a result of this support of the articulated spring on the contact wall, the slide stroke is transmitted to the contact rocker 128 when the slide moves further into its switch-on position according to FIG. 9, and this is tensioned thereby.

FIGS. 12 to 14 show a third embodiment variant of a battery isolating switch. The figures show only the essential features of the battery isolating switch in a schematic form. This battery isolating switch has a housing 201, shown in part, into which an input conductor 202 connected to a pole terminal, not shown, leads, which is connected via a switch contact to an output conductor 203 leading out of the housing. The switch contact consists of a fixed contact 204 and a movable contact 205, which is arranged on a pivotable contact carrier 206. The pivotable contact carrier 206 is biased in the open position by a spring 207 and fixed in the closed position by means of a locking mechanism. The locking mechanism consists of a displaceable pin 208 which, in the closed position, opposes the contact carrier 206

Force of the spring 207 presses into the closed position. The pin 208 is slidably received in a holder 209 and has a projection 210 and 211 above and below the holder, which are arranged such that the upper projection 210 bears against the holder 209 in the closed position and the lower projection at the open position 211 is pressed against the bracket 209 via the spring 207. In chließposition of _S, the pin is locked 208 via a a Ach ^¬ se 213 pivotable lever 212, the Stirnsei ^¬ te 214 of the pivotable lever 212 to the top of the Prior ^¬ jump 210 is engaged and thus the pin 208 entge- gen of Holds down force of spring 207. The locking mechanism thus consists of the displaceable pin 208 and the pivotable lever 212.

A thermocouple 215 acts on the pivotable lever at its pivotable end, the other end of which is fixed to a holder. In the exemplary embodiment shown, the thermocouple 215 is fixed on the input conductor 202, but is electrically insulated from it. The thermocouple 215 is connected to two power lines 216 and 217, which are supplied with current in the event of a short circuit or a vehicle crash via a sensor system or an electrical evaluation circuit. The thermocouple 215 is guided in a snake-shaped manner over three deflection rollers 218, as a result of which a thermocouple with a relatively large length can be used even in the smallest space. To open the locking mechanism, the thermocouple is supplied with current, as already mentioned, whereupon it contracts and swivels the lever 212 about the axis 213 and thus releases the projection 210 on the pin 208. The pin 208 is pressed upwards via the contact carrier 206 and by the force of the spring 207 and the movable contact 205 also pivots upwards with the contact carrier 206, whereby the closing contact is opened. Due to the deflections 218, the thermocouple 215 is available in a large length, whereby the lever 212 can also be selected to be correspondingly long. Thus, only a small force is required to open the locking mechanism and to swing the lever 212 out. This force can be easily achieved with a thermocouple.

Figure 13 shows the open position of contacts 204 and

205. To close the contacts 204 and 205, a button 219 is arranged in the housing 201, which on the one hand has a Handle 220, when pressed, pushes the displaceable pin 208 into its closed position and which at the same time engages behind the pivotable lever 212 via an L-shaped arm 221 in such a way that it is also pivoted back into its locking position. By pivoting the lever 212 back, the thermocouple 215 is stretched at the same time. The pin 208 protrudes somewhat in the direction of the push button 219 via the upper projection 210, so that the pivotable lever 212 strikes against this protruding part when the push button 219 is pressed. An over-stretching or over-stretching of the thermocouple 215 is therefore not possible. The push button 219 is always pretensioned in its open position via a compression spring 222 which acts on the holder 209 and must therefore be pressed against the spring force of the spring 222. By manually stretching the thermocouple 215, the thermocouple does not have to overcome the force of a return spring during the contraction, whereby the full contraction force of the thermocouple is available.

Claims

claims

1. disconnector for the load current circuit of a Fahrzeugbatte ^¬ rie having the following features: - a housing (1; 111, 112, 201),

- an input conductor (5; 117, 202) which can be connected to a pole terminal (21, 114),

- an output conductor (6; 120, 203) that can be connected to the load circuit, - a fixed one (64, 121, 204) and a movable one

Contact (81, 126, 205) for establishing a switching connection between the input conductor (5, 117, 202) and the output conductor (6, 120, 203),

a contact carrier (8, 128, 206) which bears the movable contact (81, 126, 205) and can be switched between an open position and a closed position and is spring-biased into the open position,

- A locking mechanism that fixes the contact carrier (8, 128) in the closed position - and a means for opening the locking mechanism, characterized in that the means for opening the locking mechanism is a thermocouple (4, 104, 215) from a shape memory -Alloy is that contracts when heated.

2. Disconnector according to claim 1, characterized in that the locking mechanism has a clamping element (32, 33; 141) which, in its extended position, presses the movable contact (81, 126) against the fixed contact (64, 121) and opens it of the locking mechanism, the thermocouple (4, 104) acts on the tensioning element (32, 33; 141), which bends it out laterally.

3. Disconnector according to claim 2, characterized in that the thermocouple (4, 104) acts on the tensioning element (32, 33; 141) via an actuating arm (42, 130).

4. Disconnector according to claim 3, characterized in that the actuating arm (42, 130) is designed as a return spring for the thermocouple (4, 104).

5. Disconnector according to one of claims 2 to 4, characterized in that the locking mechanism is designed as a toggle lever tensioning device and the tensioning element consists of a first lever (32) engaging on the contact carrier (8) and a second lever (33) mounted in the housing, which are connected via a middle knee joint (37) to a toggle lever which, in an approximately stretched state, locks the contact carrier (8) in its closed position.

6. Disconnector according to one of claims 1 to 5, characterized in that the contact carrier is an elongated, one-sided clamped in the housing contact spring (8) which carries the movable contact (81) in the central region of its length and at its free or movable end (82) engages with the outer end of the first knee joint lever (32) to form a first swivel joint.

7. Disconnector according to claim 6, characterized in that the free end (82) of the contact spring (8) and the outer end of the first lever (32) in the form of a hook (83) and an eyelet (32b) interlock.

8. Disconnector according to one of claims 5 to 7, characterized in that the thermocouple via the actuating arm (42) approximately perpendicular to the extension axis of the toggle lever on the middle Knee joint (37) acts and moves in the thermal contraction ^¬ element (4) over the dead center.

9. Disconnector according to one of claims 5 to 8, characterized in that the actuating arm (42) is formed by an offset leaf spring, the offset end of which presses upon contraction of the thermocouple on the knee joint (37).

10. Disconnect switch according to one of claims 5 to 9, characterized in that a shutdown button mounted in the housing (1) engages the middle knee joint (37) and enables the contacts to be opened manually.

11. Disconnector according to claim 5 to 10, characterized in that the second lever (33) is extended beyond the fixed outer end to a switch lug (35) which is accessible through a housing opening (72) for manual operation.

12. Disconnect switch according to one of claims 1 to 4, characterized in that the contact carrier is a contact rocker (128), the contact rocker (128) between a closed position and an open position pivotable and biased into the open position by a tear spring (127b) and as a clamping element between the contact rocker and an abutment (137), an articulated spring (141) is clamped, on the central area of which the thermocouple (104) acts and which has a preferred deflection against the direction of action of the thermocouple (104), this deflection due to the thermocouple (104) is limited to a size that is smaller than the change in length of the thermocouple, such that the almost elongated buckling spring (141) when the disconnector is switched on

Contact rocker (128) pretensioned into its switch-on position, while when the thermocouple (104) responds, the buckling spring (141) by the contraction of the thermocouple moved (104) ih ^¬ dead center and through the Aufreißfeder (127b) entge ^¬ gen their preferential bending with simultaneous movement of the contact rocker (128) in the switch-off position is flexed.

13. Disconnector according to claim 12, characterized in that the abutment for the buckling spring (141) is formed by a slide (137) movable in the longitudinal direction thereof, which by a manual actuating member (139) between a switch-off position in which the buckling spring (141) in the open position of the contact rocker (128) it can assume its extended position or the preferred deflection and a switch-on position in which the elongated buckling spring (141) prestresses the contact rocker (128) in its closed position.

14. Disconnector according to claim 13, characterized in that the slide (137) is guided by a longitudinal guide (136, 144) approximately parallel to the elongated buckling spring (141) and is biased by the tear spring (127b) via the buckling spring (141) into the switch-off position is.

15. Disconnector according to claim 13 or 14, characterized in that a rotary switch (139) serves as a manual actuator, the axis of rotation (138) of which is perpendicular to an extension line of the elongated buckling spring (141) and which has an eccentric driving pin (142) on a cross engages with the driving edge (143) of the slide (137) extending to the extension line with a pivoting range asymmetrical to the extension line.

16. Disconnector according to one of claims 12 to 15, characterized in that the movable contact piece (126) via a flexible line (125) is connected to the input conductor (117).

17. Disconnector according to one of claims 12 to 16, characterized in that the movable contact piece (126) is connected to the contact rocker (128) via a contact spring (127a) designed as a flat form spring (127).

18. Disconnect switch according to one of claims 12 to 17, characterized in that a tear-open spring (127b) is used with a flat spring (127) connected to the contact rocker (128) and biased against a stationary stop (124).

19. Disconnector according to claim 18, characterized in that the contact spring (127a) and the tear spring (127b) are designed as sections of a one-piece flat spring (127).

20. Disconnector according to one of claims 12 to 19, characterized in that the contact rocker (128) is rotatably mounted on a fixed bearing journal (148).

21. Disconnector according to one of claims 1 to 20, characterized in that the voltage source is a vehicle battery and that the thermocouple (4, 104) can be controlled by a short circuit sensor (152) and / or an acceleration sensor.

22. Disconnector according to one of claims 1 to 21, characterized in that the housing (1; 111, 112) on a pole terminal of the vehicle battery terie, the pole terminal (21, 114) itself is arranged recessed.

23. Disconnector according to one of claims 1 to 22, characterized in that at least one sensor (122) in the housing (1, 111, 112) is arranged on ^¬ .

24. Disconnector according to claim 23, characterized in that a current sensor (152) is arranged in the housing (111, 112), which is coupled to the input conductor (117) and applies a current to the thermocouple (104) when a current threshold is exceeded.

25. Disconnector according to one of claims 1 to 23, characterized in that in the housing (1, 111, 112) an electrical evaluation circuit (150) for controlling the thermocouple (4, 104) is arranged.

26. Disconnector according to claim 1, characterized in that the locking mechanism has a displaceable pin (208) and a pivotable lever (212), the pin (208) pushing the contact carrier (206) into its closed position and the lever (212) locks the pin (208) and, to open the locking mechanism, the thermocouple (215) is connected to the pivotable lever (212) in such a way that when the thermocouple (215) contracts, the pin

(208) releases and the preloaded contact carrier (206) moves into the open position.

27. Disconnector according to claim 1 or 26, characterized in that the thermocouple (215) is deflected via deflection rollers (218).

28. Disconnector according to claim 1 or 26, characterized in that the resetting of the thermocouple (215) is carried out by manually operable means (219, 213, 212).