EP0184652B1 - Switch with fuse - Google Patents

Abstract

1. A manually operated fuse switch (1) with a switch rocker (16) and a duct (4) accommodating the fuse link (5), whose switch rocker (16) covers the duct (4) for the fuse link (5) when the switch (1) is in the switched on position, - the switch rocker (16) - having a lever type design, - comprising an actuating arm (46) and a drive arm (45) and - the drive arm (45) being locked in the open position of the switch rocker (16) by a catch (56) when the fuse link (5) has been removed or incorrectly inserted, characterized in that the actuating arm (46) of the switch rocker (16) comprises a knee joint (49) subdividing the actuating arm (46) into an inner arm (47) and outer arm (48), which knee joint is spring loaded against the switching on direction (41) of the rocker.

Description

The invention relates to a manually operated safety switch with the features listed in the preamble of claim 1. Fuse switches of this type are used in a row, in particular for household fuses in the low-voltage range.

Such switches, for example known from DE-A-29 34 149 or DE-A-26 18360, have a flap-shaped switching rocker on the top of their housing, with which a switch located in the housing is operated by hand. In the closed position of the switch, the shaft for the fuse link is covered by the switching arm. As a result, the switching rocker must first be brought into the open position for the fuse exchange, the supply-side contact for the fuse link being disconnected from the power supply. At the same time, if the fuse link is not or not correctly inserted, a locking mechanism is actuated which blocks the shift rocker in its open position. This ensures a high degree of safety for the user.

The invention is based on the experience that in practice the locking arm can be destroyed by a violent actuation. This either leads to the inoperability of the switch or, in the worst case, to a closing of the circuit breaker, whereby the supply-side foot contact of the fuse base is energized despite the missing or improperly used fuse link. In particular, if an electrical consumer is protected several times by fuse switches placed side by side in blocks, parts of the consumer can be energized via the parallel fuse switches with a properly inserted fuse link, although there is obviously an error in the circuit of the consumer.

The invention has for its object to provide a safety switch of the type mentioned in such a way that the locking of the safety switch is effectively protected against destruction by violent manual operation of the rocker arm.

This is ensured by an embodiment of a manually operated safety switch in accordance with the characterizing feature of claim 1.

Advantageous further developments and design features of the invention are described in the further claims.

The knee joint according to the invention in the actuating arm of the switching rocker ensures that it is not rigid in itself. When the fuse link is removed and the shift rocker is blocked, the knee joint bends from its extended position against the spring load to its kink position when the switch is pressed violently. The latching action is thus not subjected to the full actuating force — which is multiplied by the lever ratios in conventional safety switches — but only to a fraction thereof depending on the spring load.

The characterizing features of claims 2-4 describe a constructionally particularly useful solution to the problem. The knee joint is acted upon in the extension direction by a torsion spring arranged coaxially with its rotating sleeve. This torsion spring can be virtually integrated into the joint, which results in a particularly compact and space-saving structure. The special selection of the spring constant ensures problem-free functioning of the fuse switch according to the invention. Since the transferable forces are greater than the switch-on forces to be overcome, a safe closing of the switch is possible at any time if the fuse is used properly. If the shift rocker is blocked, only a fraction of the actuating force is transferred to the catch by the spring. By designing the spring, this force is so low that there is no risk of destruction for the latching components of the switch. In addition, the switch arm behaves like a conventional fuse switch when the fuse link is inserted correctly. For untrained personnel, there are no changes in operation. The special, technically advantageous behavior of the safety switch according to the invention only becomes apparent when the device is operated incorrectly.

Since the knee joint is arranged in the inner region of the actuating arm in the vicinity of the pivot point of the switching arm, the switch can only be actuated via the kink-proof outer leg of the actuating arm. Since the inner leg is very short, it does not offer a contact surface for actuating the switch. In addition, due to the arrangement of the knee joint in the vicinity of the fulcrum with respect to the latching point, there are approximately equal lever ratios. This facilitates the selection of the torsion spring, since its spring constant only has to be selected so that the maximum transferable force is less than the breaking force for the locking point. There is no need for complex calculations based on different leverage ratios.

The characteristics of claims 6-8 protect the knee joint particularly well from outside access and improper manipulation. Since the torsion spring does not protrude beyond the outline of the shift rocker, its pointed ends cannot cause injuries to the operating personnel.

Due to the kink direction side behind the Abutment surfaces arranged on the knee joint for mutual abutment of the inner and outer legs against one another effectively prevent the knee joint from overstretching when the switching rocker is actuated in the opening direction. A stable construction of the knee joint is achieved in particular by the angular design of the stop surfaces. Since the abutment surfaces are essentially interlocking, the surface pressure acting on them is evenly distributed. This characteristic is further supported by the characterizing feature of claim 11, since a particularly large amount of "meat" is created for the abutment of the knee joint and the two stop surfaces. The invention therefore proposes a circuit breaker which, combined with its advantages, is very reliable and largely protected against damage.

The fuse switch has particular advantages when several of its type, as described in claims 12-14, are combined to form a switch block.

If only one fuse element is not inserted or is not inserted correctly, all of the fuse switches are blocked by the locking device fitted in this fuse switch and the rigid connection of the drive arms. Since all the actuating arms of the switching rockers are secured by a knee joint, it is not possible to destroy the latching and to energize the consumer, which is connected to the fuse block, in whole or in part. This brings with it a significant safety advantage over the switch blocks according to the prior art. A particularly advantageous, since simple construction for the shift rocker is described in claims 13 and 14. The entire block is operated by a single rocker arm, which is secured by a knee joint.

• Fig. 1 eine Draufsicht auf eine geöffnete Gehäusehälfte des Sicherungsschalters bei vorschriftsmäßig eingesetztem Sicherungseinsatz und in Einschalt-Stellung befindlichem Lastschalter,
• Fig. 2 eine Draufsicht entsprechend Fig. 1 bei entnommenem Schmelzsicherungseinsatz und in Ausschalt-Stellung befindlicher Schaltwippe und Lastschalter,
• Fig. 3 eine Draufsicht entsprechend Fig. 1 und 2, bei entnommenem Schmelzsicherungseinsatz bei angedeuteter Betätigung der Schaltwippe trotz Blockierung.

The invention is explained in more detail using an exemplary embodiment shown in the figures. Show it:

• 1 is a plan view of an open housing half of the fuse switch when the fuse link is used correctly and the load switch is in the switch-on position,
• 2 is a plan view corresponding to FIG. 1 with the fuse insert removed and the rocker switch and load switch in the off position,
• Fig. 3 is a plan view corresponding to FIGS. 1 and 2, with the fuse insert removed with indicated operation of the rocker switch despite blocking.

The fuse switch, designated overall by 1, is composed of two housing halves 2 made of insulating material, only one of which is shown in the figures. The parting line between the housing halves 2 runs in the drawing plane of the figures. The two housing halves 2 are riveted together in the final state. The rivets extend through the through holes 3. The safety switch 1 contains a shaft 4 for receiving the fuse link 5. For the power connection of the fuse link 5, the terminals 6, 7 are used. The terminal 7 is electrically conductively connected via the lead 10 to the threaded goggles 8, in which those firmly connected to the retaining cap 9 Screw cap 11 can be screwed in with its thread.

The fuse link 5 is provided at its head and foot ends with one end contact, namely the head contact cap 12 and the foot contact cap 13. When the screw cap 11 is screwed in according to the regulations, there is a conductive contact between the screw cap 11 and the head contact cap 12 of the fuse link 5. The foot contact 13 of the fuse link 5 rests against a counter contact 14 which is movable within the housing in the plane of the drawing. The counter contact 14 leads laterally from the area of the shaft 4 to a contact bridge 15 of a load switch which can be actuated by the switching rocker 16. When the load switch (FIG. 1) is switched on, the contact bridge 15 rests with its two contact ends 17, 18 on the mating contact ends 19, 20 of the mating contact 14 of the fuse link 5 or the contact tab 21 connected to the connecting terminal 6.

The contact bridge 15 is acted upon by the pressure of the closing springs 22, 23 in the direction of the mating contact ends 19, 20 or in the direction of the switch-on position. The lower ends of the closing springs 22, 23 are supported on the housing wall 24.

At the top of the contact bridge 15 is a pressure ram 25 made of insulating material with its front end. The plunger 25 is mounted in the pressure switch of the closing springs 22, 23 or at right angles to the longitudinal extent of the contact bridge between the housing walls 27 within the fuse switch 1. Because it rests on the contact bridge 15, it lies in the intermediate space between the mating contact ends 19, 20 which are electrically conductively connected to one another by the contact bridge 15 when in use.

The rocker switch 16 is pivotally mounted on the safety switch 1 about the axis of rotation 28 running perpendicular to the plane of the drawing. It is provided at its end 29 facing the pressure tappet 25 with a recess 30 for receiving the rocker arm-side link - hereinafter called rocker arm link 31 - one formed from the link arm 31 and the further link 32 and designated 33 as a whole. The free end of the rocker arm 31 is pivotally mounted about the axis of rotation 28 of the rocker arm 16. The handlebar 32 serves as a pressure transmission part and rests with its free end 34 on the rear side of the pressure ram 25 facing away from the contact bridge 15. The free end 34 of the link 32 rests in a notch 35 arranged on the rear of the pressure ram 25 in such a way that that it can be pivoted about a certain angular amount around the gusset of the notch 35 in the plane of the drawing of the figures. Due to the action of the contact bridge 15 and the pressure plunger 25 by the closing springs 22, 23, the handlebar 32 is permanently in the notch 35 with its free end 34.

When the switching rocker 16 is transferred from the switched-on position (FIG. 1) to the switched-off position (FIG. 2), the toggle lever 33 is pressed through its extended position (not shown) by the lower end of the recess 30 in the switching rocker 16. The articulation axis 37 of the toggle lever 33 moves downwards in the direction of the contact bridge 15. The push rod 25 is pressed downward via the link 32 (arrow direction 26) and the contact bridge 15 is lifted off the mating contact ends 19, 20 (FIG. 2).

The structure and mode of operation of the locking device for the shift rocker 16 will be briefly described below. It essentially contains a locking bracket 37 running in the direction of the arrow 26, which is fastened with its contact-side end 38 to the mating contact 14 in the edge region of the shaft 4 on the contact bridge side. The free end 39 of the locking bracket 37 is located around the circumferential area of the end 29 of the rocker arm 16. In the switched-off position of the rocker arm 16, the recess 30 is opposite this free end 39 of the locking bracket. The counter contact 14 of the fuse link 5 is acted upon from its underside by the contact spring 40, which is supported with its foot on the housing wall 24. In the switched-off position (FIG. 2) of the rocker arm 16, the recess 30 is opposite the free end 39 of the locking bracket 37. If the fusible link insert 5 is now removed, the counter spring 14 is acted upon by the contact spring 40 and the free end 39 of the locking bracket is moved into the recess 30. When actuating the rocker arm 16 in the switch-on direction 41, the free end 39 of the locking bracket 37 comes into contact with the edge 42 of the recess 30, as a result of which the rocker arm 16 is blocked. This situation is shown in Fig. 3.

The structure and function of the rocker arm 16 will be explained below with reference to this figure: The rocker arm 16 is designed as a lever and is mounted on the safety switch 1 so that it can pivot about the axis of rotation 28. It is essentially L-shaped, the L horizontal leg 43 merging at its free end into a cylindrical roller 44 arranged concentrically about the axis of rotation 28. In its peripheral region on the contact side, this cylindrical roller 44 has the recess 30, into which the locking bracket 36 engages when the fuse link 5 is not or not correctly inserted and in which the switching rocker arm 31 lies. The contact-side part of the cylindrical roller 44 thus serves as the drive arm 45 for the toggle lever 33 and thus for the actuation of the contact bridge 15 via the pressure tappet 25. The contact-side part of the cylindrical roller 44 together with the L-shaped part is referred to as the actuating arm 46. This actuating arm 46 is divided into an inner leg 47 and outer leg 48 by the knee joint 49 arranged in the transition region between the cylindrical roller 44 and the L horizontal leg 43. fas knee joint 49 is acted upon by a torsion spring 51 mounted concentrically with its hinge axis 50 against the switch-on direction 41 of the switching rocker 16. The loading force is transmitted through the free ends 53, 54 of the torsion spring 51 by the fact that they abut on the side of the inner leg 47 or outer leg 48 facing the folding direction 55. The torsion spring has such a spring constant that the forces that can be transmitted through it are greater than the switch-on forces to be overcome, but less than the locking force of the latching device 56 produced by the locking bracket 37. As a result, the knee joint 49 remains essentially in its extended position during the actuation process when the shift rocker 16 is not blocked (FIG. 1) due to the spring load. When the rocker arm is blocked (FIG. 3), the knee joint 49 is moved into its kink position.

3 shows a particularly advantageous embodiment for the formation of the switching rocker 16 with its knee joint 49. The knee joint 49 lies in the recess 57 which extends in the transition region between the cylindrical roller 44 and the L-horizontal leg 43 without the free ends 53, 54 the torsion spring 51 protrude beyond the contour surface of the rocker arm 16. Starting from this recess 57, the division joint 58 extends in the circumferential area of the cylindrical roller 44. The inner 47 and outer legs 48 have mutually facing stop surfaces 59, 60 which lie one inside the other in the extended position of the knee joint 49 (FIGS. 1, 2). The angled shape of the abutment surfaces 59, 60 is advantageous in such a way that actuating forces occurring virtually in any direction are distributed as well as possible by the positive engagement of the angular surfaces. The special design of the rocker arm 16 as an L-shaped part and cylindrical roller 44 also creates an increase in the mutual abutment surfaces 59, 60, which further reduces the specific surface pressures that occur.

A multiple-pole switch block can be formed by a plurality of fuse switches 1 arranged parallel to one another in accordance with FIGS. 1-3. In such switch blocks, the individual rocker arms 16 are mounted coaxially on an axis of rotation 28. It is advantageous according to the invention if the cylindrical rollers 44 forming the inner leg 47 of the actuating arm 46 or the drive arms 45 are rigidly connected to one another. In practice, this is achieved by using an integral, continuous cylindrical roller 44 for the individual fuse switches 1 of the fuse block. This rigid connection ensures that when a siche is locked tion switch 1 the entire fuse block is locked by engaging the relevant locking bracket 37 in a recess 30. Since the outer legs 48 of the rocker arm 16 can each be bent off by the knee joint 49, the securing block can neither be actuated nor the latch 56 destroyed by violently moving the rocker arm 16 into the switch-on position (FIG. 1).

Due to the rigid connection of the outer legs 48 of the actuating arms 46 of the individual fuse switches 1, these act as a unitary whole as a multi-pole fuse block, the locking function preventing the entire block from starting from a single pole when the fuse link 5 is not or not correctly inserted. In this case, the rigid connection of the cylindrical rollers 44 to a coherent component is unnecessary. If only one drive arm 45 is blocked by the latching, the rigid connection of the outer legs 48 to one another means that only a buckling torque can be transmitted to all of the knee joints, but no starting torque can be transmitted to the unblocked drive arms.

Reference symbol list

• 1 safety switch
• 2 housing half
• 3 through hole
• 4 shaft
• 5 fuse link
• 6 connecting terminal
• 7 connecting terminal
• 8 threaded glasses
• 9 retaining cap
• 10 supply line
• 11 screw cap
• 12 head contact cap
• 13 foot contact cap
• 14 counter contact
• 15 contact bridge
• 16 shift arms
• 17 contact end
• 18 contacts
• 19 mating contact end
• 20 mating contact ends
• 21 contact flag
• 22 closing spring
• 23 closing spring
• 24 housing wall
• 25 plungers
• 26 direction of arrow
• 27 housing wall
• 28 axis of rotation
• 29 end
• 30 recess
• 31 swing arm control
• 32 handlebars
• 33 toggle lever
• 34 freeers
• 35 notch
• 36 joint axis
• 37 locking bracket
• 38 end
• 39 freeers
• 40 contact spring
• 41 Switch-on direction
• 42 margin
• 43 horizontal legs
• 44 cylindrical roller
• 45 drive arm
• 46 operating arm
• 47 inner thighs
• 48 outer legs
• 49 knee joint
• 50 joint axis
• 51 torsion spring
• 53 free users
• 54 offenders
• 55 direction of buckling
• 56 latching
• 57 recess
• 58 dividing line
• 59 stop surface
• 60 stop surface

Claims (14)

1. A manually operated fuse switch (1) with a switch rocker (16) and a duct (4) accommodating the fuse link (5), whose switch rocker (16) covers the duct (4) for the fuse link (5) when the switch (1) is in the switched on position,

-the switch rocker (16)

-having a lever type design,

-comprising an actuating arm (46) and a drive arm (45) and

-the drive arm (45) being locked in the open position of the switch rocker (16) by a catch (56) when the fuse link (5) has been removed or incorrectly inserted,

characterized in that the actuating arm (46) of the switch rocker (16) comprises a knee joint (49) subdividing the actuating arm (46) into an inner arm (47) and outer arm (48), which knee joint is spring loaded against the switching on direction (41) of the rocker.

2. A fuse switch according to claim 1, characterized in that the folding direction (55) of the knee joint (49) is the same as the switching on direction (41) of the switch rocker (16).

3. A fuse switch according to claim 1 or 2, characterized in that the spring producing the spring loading in the knee joint (49) is a torsion spring (51) arranged coaxially with the articulation pin (50) of the knee joint (49), the free ends (53, 54) of which spring act, on the one hand, on the inner arm (47) and on the other hand, on the outer arm (48) of the actuating arm (46) on the side facing the folding direction (55).

4. A fuse switch according to claim 4, characterized in that the torsion spring (51) has a spring constant such that the forces it can transmit are greater than the switching on forces to be overcome, but smaller than the locking force of the catch (56), such a way that in the actuation process when the switch rocker (16) is not locked, the knee joint (49) remains substantially in its stretched position because of the spring loading, and when the switch rocker (16) is locked, the knee joint (49) is moved over into its folded position.

5. A fuse switch according to one of the preceding claims, characterized in that the knee joint (49) is arranged in the internal zone of the actuating arm (46) near the axis of rotation (28) of the switch rocker (16).

6. A fuse switch according to one of the preceding claims, characterized in that the actuating arm (46) of the switch rocker (16) has an L-shaped design with the vertical arm of the L covering the duct (4) in the "on" position and uncovering the duct (4) in the "off" position, the knee joint (49) being arranged on the inside on the horizontal arm (43) of the L comprising the articulation pin (50).

7. A fuse switch according to claim 6, characterized in that the horizontal arm (43) of the L has, on its inner side facing the folding direction (55), a recess (57) wherein the knee joint (49) comes to be disposed.

8. A fuse switch according to claim 7, characterized in that the torsion spring (51) is arranged inside the contour area of the L.

9. A fuse switch according to one of the preceding claims, characterized in that the inner arm (47) and outer arm (48) of the actuating arm (46) have, on the side away from the folding direction, bearing surfaces (59, 60) for their mutual bearing contact which face each other and are arranged behind the knee joint (49).

10. A fuse switch according to claim 9, characterized in that the bearing surfaces (59, 60) have an angular design and that in the extended position of the knee joint (49), they fit into each other with a substantially conjugate fit.

11. A fuse switch according to one of the preceding claims, characterized in that the inner arm (47) of the actuating arm (46) and the drive arm (45) are formed together by a cylindrical roll (44) mounted for rotation.

12. A multipole switch block consisting of fuse switches (1), disposed parallel and next to each other and formed according to one of the above mentioned claims, characterized in that the switch rockers (16) are mounted coaxially and in that the drive arms (45) or inner arms (47) of the actuating arms (46) are rigidly interconnected with repsect to the rotational switching on and switching off movements.

13. A multipole switch block consisting of fuse switches (1), disposed parallel and next to each other and formed according to one of claims 1-11, characterized in that the outer arms (48) of the actuating arms (46) are rigidly interconnected with respect to the rotational switching on and switching off movements.

14. A multipole switch block according to claim 13, characterized in that the outer arms (48) are made integrally of a synthetic material.

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