DE3020593A1 - ELECTRIC SWITCH - Google Patents

Description

The invention relates to electrical switches and in particular to but not limited to limit switches, which are normally associated with movable covers or fenders used for machines.

It is known to have such machines, which are classified as dangerous, with movable covers or guards to prevent the operating personnel from having access to the machine while it is in operation. the Power supply for such a machine is controlled by an electrical control, which has a stop switch which is actuated by the movable cover or the fender. The arrangement is made in such a way that that when the cover is in its closed position, the switch from the cover is in its Connection or closed position is held and the machine receives its operating current. The switch is activated by the Opening of the cover brought into its interruption position, so that the supply of the operating current is interrupted and the machine is stopped. This stop and the subsequent one Delay in reaching full production speed when restarting causes a production downtime, which in a disadvantageous way, the payment of the operating staff, if they are based on numbers of items or allowances on the Basis of productivity. Accordingly, there is a tendency to tamper with the switches or to wedge them in such a way that that they remain in the closed position even when the cover is open, so that the operating personnel is exposed to considerable risk.

The object of the invention is therefore to specify electrical switches for machines that effectively interrupt of the circuit, so that when the cover is open there is no danger to the operating personnel.

According to the invention, the electrical switch has electrical

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Contacts that can be brought into interruption positions and ■ connection positions, as well as a lock that between a first position in which they prevent the connection of the contacts and a second position is movable in which it enables the connection of the contacts, whereby the lock is made by the magnetic action of one magnet on another is movable.

In an embodiment according to the invention are at least first and second electrical contacts are provided, at least one being movable relative to the other, so that a Connection can be established or interrupted by bringing them into contact or separating them from each other. The barrier is placed between the contacts to prevent their mutual contact until the lock is out of position has been brought into a release position between them. Until the movement has taken place in the release position maintaining the lock in the locked position ensures the force of magnetic repulsion or attraction between the first and second magnets. The second magnet is arranged stationary or fixed relative to the first magnet, which in turn is between first and second positions is movable. The lock is arranged to follow the movement of the first magnet, the first position the first magnet of the locking position of the lock and the second Position corresponds to the release position of the lock.

A third magnet can be moved in the vicinity of the first magnet, with the effect that the magnetic field between the first and third magnets exerts a repulsive force or attractive force of sufficient magnitude on the first magnet, which moves it from the first position to the second position and thus brings the lock into its release position. If the third magnet is moved away so that its influence on the first magnet decreases to a sufficient extent, the effect of the magnetic field between the first and second magnets is in the position © _? You can exercise control over the first magnate, among other things, in the first position

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bring back, taking part in the movement the movement of the Lock connects, which returns to the locked position, provided the contacts are separated.

The barrier is preferably made of electrically insulating material.

The lock can be formed on a lever arrangement which is acted upon by the movement of the first magnet will.

The third magnet is preferably arranged and designed in such a way that it repels the first magnet relatively strongly while the second magnet exerts a weaker repulsive or attractive force on the first magnet. Accordingly, it holds the second magnet the first magnet in the first position and thus the lock in the locked position until the point in time where the first magnet with the stronger attraction or repulsion force of the third magnet is applied.

The movable contact or contacts can be moved as desired. However, to have a synchronous To ensure operation, it is preferable when the contact movement for establishing the connection from the movement of the third magnet in the vicinity of the first magnet and the interruption s movement to break the contacts is accompanied by the withdrawal of the third magnet. This can be done by can be achieved that the third magnet is moved depending on the movement of an actuating part, that causes the contact movement.

The invention is therefore particularly suitable for stop switches and circuit breakers, since the contacts are not simple can be connected using the actuating part, since the third magnet is required to move the lock is.

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The invention is explained below with reference to the description of FIG Embodiments and explained in more detail with reference to the accompanying drawing. The drawing shows in

Pig. 1 is a partial plan view of a conventional circuit breaker;

2 and 3 partial side views, partly in section, of the switch according to FIG. Liaison positions;

4- a schematic partial view of a first according to the invention Embodiment of the switch, wherein the lock is in the locked position;

Fig. 5 is a view similar to Fig. 4- showing the lock shows in their release position;

6 shows a side view of a component for actuating the switch according to FIG. 4; and in

7 is a partial perspective view of another embodiment of the switch according to the invention.

In the description below, the same reference symbols are used for the same or corresponding parts.

In the arrangement according to FIGS. 1 to 3, the conventional switch has a housing 2 with an inner partition 4. The housing 2 is covered with a cover 6 which has a slot 8 at one end. The housing 2 contains stationary electrical contacts 10a and 10b, each provided with a bump or projection. These electrical contacts 10a and 10b are mounted on an insulating support 12 and are used to connect electrical lines in an external electrical circuit by means of devices not shown. The "partition or partition 4 supports a slidable tubular arm 14 which carries a fixed insulating strip 16 which carries a circuit board 18 with movable conductive contacts 20a and 20b in the form of bumps or projections. One end of the arm 14 is in engagement with a compression spring 22, which is in a tubular

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shaped bore 24 in the carrier 12 is seated. The other end of the Arm 14 is slidably held in a stationary tube 26, which extends in the longitudinal direction, diametrically opposite slots 28 through which opposite ends of a pin 30 extend and are in engagement with the arm 14. At these ends, arms 32 are attached to joints 34 on radial side parts 36 of recesses hinged into opposite ends of a cylinder 38 are incorporated, which is provided with a groove 40 running in the longitudinal direction. The cylinder 38 is about an axis 42 rotatably mounted in a stationary or fixed support 44.

To close the switch and establish the connection, an L-shaped actuator or tongue 46 is inserted through the slot 8. This pushes the foot 48 of the L-shaped Actuating part 46 on the side part 40a of the slot 40, so that the cylinder 38 in the arrangement according to Fig. 3 rotates counterclockwise, the arms 32 after moves to the right and forces the arm 14 to move in the same direction, so that \ the movable contacts 20a and 20b come into contact with the stationary contacts 10a and 10b and the circuit with the stationary contacts is closed.

The insulating strip 16 is attached to the arm 14 with corresponding standard parts on the lower part of the insulating strip 16, engaging longitudinally extending slots in opposite side portions of the arm 14 of FIG only one of which is indicated at 17. This lower part of the In the arrangement according to FIGS. 2 and 3, the insulating strip 16 is constantly pressed in the direction of the right-hand end of the slots 17, and . although under the action of a compression spring 17a within the arm 14, one end of the compression spring 17a acts on the insulating strip 16 and presses the other end against a stop 17b fastened inside the arm 14.

This arrangement enables the arm 14, in the arrangement according to FIG. 3, its movement to the right relative to the

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ORIGINAL INSPECTiQ

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Insulating strip 16 continues for a short distance under the action of actuator 46 after the contacts 20a and 20b have come to rest against the contacts 10a and 10b, thus placing excessive stress on the insulating strip to avoid during the end of the insertion movement of the actuating part 46 into the slot 8.

In order to interrupt the switch, the actuating part 46 is withdrawn from the slot 8. In doing so, the foot 48 exercises one Pulling movement against the side part 40b of the slot or groove 40 and rotates the cylinder 38 clockwise. In order to the arms 32 in the arrangement according to FIG. 3 to the left and the arm 4V 'is also pulled to the left. In this case press in the arrangement according to FIGS. 2 and 3, the right Ends of the slots 17 the insulating strip 16 to the left, wherein the arm 14 ensures that the movable contacts 20a and 20b separate from the stationary contacts 10a and 10b, with whom they may have entered into an intimate connection through the heat of the electric current.

The housing 2 can be stationary and the actuating part 46 on a movable cover or a guard plate of a machine be mounted to make the connection of the switch when the cover is closed and the switch interrupt when the cover is open. Unfortunately, it is the case that the slot 8 has been tampered with Metal wedges, which press on the side part 40a of the groove 40, can hold the switch in the closed position, when the movable cover is open.

In the embodiment according to the invention shown in FIGS. 4 to 6, there is an obstacle or a barrier 50 made of insulating material at one end of a lever arm 54 free hinged, the with a hinge 56 on an upper extension 12a of the carrier 12 is articulated. A magnetic disk 58 is on other end of the lever arm 54 and is, as in Fig. 4, attracted by a holding magnet 60,

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so that the lock 50 is in the way of the moving contact 20a is located and is arranged between the movable contact 20a and the corresponding stationary contact 10a. Of the Holding magnet 60 is mounted on a stationary partition or partition 4a made of non-magnetic material, in which it is an extended embodiment of the subdivision 4 in the arrangements according to FIGS. 1 to 3, and the Switch is covered with a cover 6, which is in Pig. 4 is indicated by dash-dotted lines.

Until the lock 50 is moved out of the way of the contact 20a there are two options. Either (i) none of the moving contacts can match the corresponding stationary ones Contacts come into contact, or (ii) the contact 20a is prevented by the lock 50 from coming into contact with the contact 10a To come into contact, and thus the circuit between the contacts 10a and 10b is not closed via the circuit board 18, even if the arrangement of the insulating strip 16 on the arm 14 causes a certain twisting of the insulating strip should allow relative to the arm so that the contact 20b can touch the contact 10b. To prevent damage to the To avoid lock 50 and arm 54- is hinge 56 preferably shorter than shown in the drawing, so that the barrier is located closely along the contact 10a. In order to the pressure of the contact 20a on the lock 50 is substantially transferred from there to the contact 10a, but not to the joint 52 or the arm 54-.

To move the lock 50 into the release position, like it shown in Fig. 5, a repulsive magnet, the is located outside the housing 2, brought into the vicinity of the magnetic plate 58, the magnet 60 moves away from the holding and thus the lever arm 54 in the arrangement according to FIGS. 4 and 5 rotates clockwise. That repulsive magnet is designated by 62 in FIG. 6 and is mounted in a carrier 64 which carries the actuating part 46. When the operating part 46 is used to make the moving contacts in

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Moving towards the stationary contacts becomes the repulsive one Magnet 62 automatically brought closer to the magnet 58, the pole face 66 of which has the same polarity as the pole face 68 of the repelling magnet 62 has. the The force of repulsion is so great that it is the force of attraction of the holding magnet 60 and the magnet 58 of the holding magnet 60 pushes away so that the lever arm 54 · clockwise rotates before contact 20a reaches the lock.

When removing the actuating part 46, the effect of the repelling magnet 62 automatically degraded, so that when the contacts separate, the holding magnet 60 the magnet 58 pulls back into the position according to FIG. 4, so that the lock 50 resumes its locking position.

The carrier 64 can be mounted on the movable cover be. Since at least contacts 10a and 20a cannot be connected to an unauthorized wedge, if not one unauthorized repulsive magnet is used to move the lock 50, stands with the switch according to the invention another nasty safety feature available that must be overcome by someone hoping that Using machine without a closure of the cover. There Even the unauthorized repelling magnet is also repelled by the magnet 58, it is quite difficult to remove the unauthorized Hold magnets in the correct position to hold the lock 50 in the release position while making the contacts are clamped closed.

A stop 70 can be used, for example, to the To limit the pivoting movement of the lever arm 54.

In order for the switch to be used in any arrangement, it may be preferable to have the lock 50 with a guide which determines the path of movement of the lock 50. This guide can be a channel on a side wall of the lock 50 have so that the contact projection of the contact 10a

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is arranged within the channel, the side walls of which are longitudinal opposite side edges of the contact protrusion.

If desired, the joint can be: 5 between the approach 12a and the subdivision 4a extend or only be mounted on the subdivision 4a, the subdivision or partition 4a is made of insulating material in each case.

The magnets can be ceramic magnets. The lever arm 54 is also preferably made of insulating material Material, and both lever arm 54 and lock 50 can be made of plastic, e.g. B. nylon exist.

The housing 2 and the cover 6 are preferably made of non-magnetic material.

With the switch according to I ¹ Xg. 7, the insulating barrier 50 'is attached to the lever arm 54' or is formed integrally therewith as a cranked end of the lever arm. The other end of the lever arm 54 'carries a permanent magnet 58', the lower pole face 70 'of which has the same polarity as the upper pole face 72 of a stationary permanent magnet 60' which is mounted on the housing 2 below the magnet 58 '. The magnet 60 'repels the magnet 58' so that the end 74 of the lever arm 54 'is rotated around the hinge 56 and the end 74 is pressed against the underside of the housing 2 and the lock 50' is between the contacts 10a and 20a and prevents their contact.

The magnet 58 'has an upper pole face 66' with the same Polarity as the pole face 68 of the magnet 62 in Fig. 6. When the actuating part 46 is inserted into the slot 8, in order to move the contacts 20a and 20b in the direction of the contacts 10a and 10b, the pole face 68 is in the vicinity of the pole face 66 'brought. The repulsion force exerted by the magnet 62 on the magnet 58 'is much greater than that of the magnet

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A force of 60 'is exerted and the lever arm 54-' rotates in Direction of arrow A to move the lock 50 'out of position to move out between the contacts 10a and 20a so that they can come into contact with each other.

This rotary movement is ended in that either the end 76 of the lever arm 54- 'with the underside of the housing 2 comes into contact, or when the magnet 60 'on the approaching magnets 58 'exerted repulsive force equal the force exerted by magnet 62 on magnet 58 '. In any case, the lever arm 54- 'will not rotated so far that it disturbs the contact 20b.

In Fig. 7, the insulating strip 16 carrying the circuit board 18 carrying the contacts 20a and 20b is complete housed in the slots 17 in the arm 14-.

In summary, an electrical switch is thus specified in which two separate stationary contacts 10a and 10b an external circuit or a circuit are connected, which can be closed by opening the contacts Brings 20a and 20b on the circuit board 18 with the contacts 10a and 10b in touch contact. A lock 50 from insulating material is articulated with a joint 52 on the lever arm 54, which is rotatable about a joint 56 and a permanent magnet 58 carries that of a stationary permanent magnet 60 is attracted to maintain the interlock between contacts 10a and 20a. This prevents that these come into contact with each other before the lock has been moved away, which is dependent on turning the lever can be done by another magnet, which is moved in the vicinity of the magnet 58, to him by the magnet 60 to push away.

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Claims (14)

PATENTANWALTS POPP & SAJDA MARIA-THERESIA-STRASSE 30, 8000 MÜNCHEN 80 POSTAL ADDRESS: POSTFACH 860624, D-8000 MUNICH 86 Patentanwalt Popp & Sajda, Postfach 860624, D-8000 Munich 86 Dr. Eugen Popp Dipl.-Ing., Dipl.-Wirt.-Ing. WoIfE. Sajda Dipl.-Phys. Telephon (089) 9818 Telex 5 22862 Spezd Telegramme Epopat Munich Your reference Our reference Date Yourref. Ourref. 1171 Date 3Π Votreref. Notre ref. \ \ C \ Date JU. EJA Engineering Company Latd. Peel Lane, Astley Manchester 29 England Electrical switch claims 1.} Electrical switch, characterized by contacts (10a, 10b, 20a, 20b) which can be brought into connection positions and interruption positions, and by a lock (50) between a first position (Fig. 4-), in which you close the contacts prevented, and a second position (Fig. 5) is movable in which it closes the contacts allows the lock (50) to be moved towards one another by the magnetic influence of magnets (58, 60, 62) is. 030050/0844 Professional Representatives Professional Representatives Mandataires agrees before the European Patent Offies before the European Patent Office pree l'Office Europeen des Brevets ORIGINAL INSPECTED 3020533 2. Switch according to claim 1, characterized in that the barrier (50) is made of electrically insulating material. 3- switch according to claim 1 or 2, characterized in that that the lock (50) in the first position (Fig. 4) or the second position (Fig. 5) by the magnetic influence is movable. 4. Switch according to one of claims 1 to 3 _5, characterized in that the lock (50) in the first position (Fig. 4) can be moved as a function of a magnetic force of attraction or repulsion. 5. Switch according to one of claims 1 to 4, characterized in that that the switch is in the second position (Fig. 5) is movable. 6. Switch according to one of claims 1 to _v 5, characterized in that the lock (50) in the first position (Fig. 4) in response to movement of a first magnet (58) relative to a second stationary magnet (60 ) is movable that the movement of the first magnet (58) takes place as a function of a force exerted on the first magnet (58) by the magnetic field between the two magnets and that after the movement this force acts in such a way that it closes the lock (50 ) in the first position (Fig. 4). 7- switch according to one of claims 1 to 6, characterized in that that the lock (50) from the first position (Fig. 4) to the second position (Fig. 5) with a movable third magnet (62) which can be brought to a location so that the magnetic field between the first (58) and third magnets (62) exerts a second force on the first magnet (58), which the 030050/0844 _ 3 - from the magnetic field between the first and second magnets (58, 60) on the first magnet (58) overcomes the first force, so that the first magnet (58) moves as a function of the second force and the lock (50) moves as a function thereof into the second position (Fig. 5) moves. 8. Switch according to claim 7? characterized in that the first force is a force of repulsion or a force of attraction is. 9 · Switch according to claim 7> characterized in that the second force is a repulsive force. 10. Switch according to one of claims 1 to 9, characterized in that that the lock (50) is arranged on a pivotable arm (54-) that the first magnet (58) is mounted on the arm (54-) and that the lock (50) is between the first (Fig. 4-) and the second position (Fig. 5) can be moved by a pivoting movement of the arm (54-). 11. Switch according to one of claims 1 to 10, characterized in that that the lock (50) is firmly mounted on the arm (54-). 12. Switch according to one of claims 1 to 10, characterized in that that the lock (50) is rotatably mounted on the arm (54-). 13 · Switch according to one of Claims 1 to 12, characterized in that that a first contact (10a, 10b) and a second contact (20a, 20b) for relative movement are arranged to one another by an amount so that the contacts can be brought into contact with one another when the lock (50) is in the second position (Fig. 5), the movement depending on the Movement of an actuating part (4-6) of the switch takes place. 030050/0844 14. Switch according to one of claims 1 to 13, characterized in that that the third magnet (62) simultaneously with the movement of the actuating part (46) in place is movable. 300 5 0/0 84