EP1746619B1 - Clamping auxiliary element - Google Patents

Abstract

The lifting clamp (1) has a rectangular frame (14) and a rectangular box (15) with an upper section (150) positioned between the upper and lower sections (140,141) of the frame and displaced relative to the latter against a resistance provided by the friction between the box and the frame. A clamp screw (16) fits through an opening (142) in the upper section of the frame for engaging a screw thread (152) in the upper section of the box.

Description

The invention relates to a lift clamp for installation in a housing of an electrical appliance, such as e.g. a circuit breaker comprising a rectangular frame and a rectangular box, the upper portion of which is disposed between the upper portion and the lower portion of the frame, whereby the box is slidably supported in the frame, further comprising a clamping screw passing through one in the upper frame. Section incorporated aperture freely rotatably guided therethrough and engages in an incorporated into the upper portion of the box thread, further comprising a fixed tab on the box extending away from the lower portion of the box in the space below the box and parallel to the plane adjacent to the Lift terminal lying opening in the housing, wherein the flap is formed parallel to the lower box portion extending plate, by means of which the flap is connected to the box and wherein the Plättcben a normal to this as well as normal to the flap extending Montageplättch is integrally formed, which is firmly connected to a side wall of the box.

Such lift clamps with fixed to the box lobes or shutters are for example from the EP 0 559 585 A and the US 5 580 285 A known. A disadvantage of the EP 0 559 585 A proves that the tab shown there is integrally formed with the metallic box and thus does not provide an electrically insulating protection. The US 5 580 285 A whereas, in a particular embodiment, shows a removable shutter. However, this shutter is attached only with small hooks on the box, so that the resulting low composite surface ensures no secure connection.

The DE 83 12 142 Ul describes a lift clamp which is movably supported in a housing of an electrical appliance, and wherein the chest has a flap-shaped enlargement which closes the space behind it when the clamp is closed. The EP 772 256 A2 describes a clamp to which a shutter made of insulating material engages, which is designed as a cuboid, on which two mounting plates are formed, which engage by means of so-called. Noses in open-edged recesses on the terminal. The US 3,539,977 A describes a clamp with a movable box, in which a spring is mounted, which is bent when the clamp is closed by the contact pressure, and thus conceals the space behind the clamp.

The object of the invention is therefore to securely connect a cloth to cover the lower receiving space with the box.

This is inventively achieved in that in the mounting plate an opening is incorporated, in which a fixed Abscherzapfen in the housing is engageable.

By this disposition of the shear bolt, in addition to its main function of providing resistance to displacement of the box, it can fulfill the auxiliary function of holding mounting plates, plates and lobes in the housing. When the components of the switch are installed in the housing, mounting plates, plates and lobes can be mechanically inserted into the lower shell. The section of the opening below the lower box section is covered thereby, thus avoiding erroneous insertion of ladders under the lower box section. The plate allows a relatively large-area contact with the box, thus ensuring a secure connection.

In a further embodiment of the invention may be provided in this connection, that on the mounting plate, a pin is formed, which engages in an incorporated in the box-side wall opening. Thus, the box on particularly simple, with little technical effort associated type, namely by merely placing the box on the mounting plate, this will be fixed.

• Fig.1 die Draufsicht auf einen mit Liftklemmen 1 ausgestatteten Leitungsschutzschalter bei abgenommener Oberschale;
• Fig.2 die lediglich mit einer Liftklemme 1 bestückte Unterschale des Leitungsschutzschalters gemäß Fig. 1 im Schrägriß, wobei die zweite Liftklemme 1 außerhalb der Unterschale liegend dargestellt ist;
• Fig.3 eine Draufsicht auf eine lediglich mit der rechten Liftklemme 1 bestückte Unterschale des Leitungsschutzschalters gemäß Fig.1, wobei im Bereich der linken Liftklemme ein am Kasten 15 der Liftklemme 1 festlegbarer Lappen 24 vorgesehen ist;
• Fig.4 das in Fig.3 Gezeigte im Schrägriß;
• Fig.5 eine Draufsicht auf eine in einem Gehäuse eingebaute Liftklemme 1, wobei der Widerstand, gegen welchen der Kasten 15 der Klemme 1 verschiebbar ist, durch eine Schrauben-Druckfeder 32 gebildet ist und
• Fig.6 das in Fig.5 Gezeigte, wobei zur Realisierung des Widerstandes anstelle der Schrauben-Druckfeder 32 ein an die Gehäuse-Innenwandung angeformter Abscherbolzen 33 vorgesehen ist.

The invention will be described in more detail with reference to the accompanying drawings, in which particularly preferred embodiments are shown. Showing:

• Fig.1 the top view of a equipped with Liftklemmen 1 circuit breaker with the upper shell removed;
• Fig.2 the only equipped with a lift clamp 1 lower shell of the circuit breaker according to Fig. 1 in oblique view, wherein the second lift clamp 1 is shown lying outside of the lower shell;
• Figure 3 a plan view of a equipped only with the right lift clamp 1 lower shell of the circuit breaker according to Fig.1 , wherein in the region of the left lift clamp a fixable on the box 15 of the lift clamp 1 lobe 24 is provided;
• Figure 4 this in Figure 3 Shown in the oblique view;
• Figure 5 a plan view of a built-in a housing lift clamp 1, wherein the resistance against which the box 15 of the terminal 1 is displaceable, is formed by a helical compression spring 32 and
• Figure 6 this in Figure 5 Shown, wherein for realizing the resistance instead of the coil compression spring 32, an integrally formed on the housing inner wall shear pin 33 is provided.

The in Fig.1 illustrated circuit breaker comprises two, designed as so-called. "Lift terminals" screw terminals 1, by means of which lead wires and the comb-like terminal lugs of busbar systems can be connected to the circuit breaker.

The circuit breaker further comprises an overload trip element 2 and a short circuit tripping device 3, next to a switching mechanism 4, the movable contact 5 from a closed position in which the movable contact 5 is applied to the fixed contact 8, in the in Fig.1 can move shown opened position.

The current to be monitored flows through in this circuit breaker starting from the right screw 1, first the overload trip element 2, passes through a movable conductor 6 and the jumper 7 to the movable contact 5, then via the fixed contact 8 to the short tripping device 3 and finally to the second terminal. 1 The switching mechanism 4 can be actuated both by the short-circuit tripping device 3 and by the overload tripping element 2. The short-circuit tripping device 3 is formed in a conventional manner by a magnetic coil with a movable armature, which beats anchor at correspondingly high short-circuit currents on the switching bridge 7 of the switching mechanism 4.

The overload release element 1 consists of a bimetallic strip which is heated by the current to be monitored. The first end 21 of the bimetallic strip is fixed in the housing of the circuit breaker, the second end 22 is held freely movable. The bending thereof caused by the heating of the bimetal therefore leads to a movement of the second end 22 in the direction of the arrow 23. With sufficient heating, the free end 22 of the bimetallic strip in this movement comes into contact with the bracket 9 acting on the pawl support 36. takes this in the direction of motion and thereby triggers a response of the rear derailleur 4.

The switching bridge 7 is biased by a spring 10 in the direction of the open position of the movable contact 5. The explained minor deflections of the pawl support 36 by the armature of the short-circuit release device 3 and by the overload release element 2 via the bracket 9 are reinforced by means of this spring 10 for complete pivoting of the switching bridge 7 in the open position of the movable contact 5.

To turn on the circuit breaker, i. for swiveling the contact carrier 7 back into the closed position of the movable contact 5, an externally accessible, manually operable lever 11 is provided.

The housing of the circuit breaker is in a conventional manner in two parts, consisting of the respectively apparent in the drawing figures lower shell 12 and not shown in the drawings, with respect to its structural design to the lower shell 12 mirror image of the upper shell executed.

The present invention relates to the lift clamps 1 and is not limited to the use of these lift clamps 1 in circuit breakers. In the drawings, only a line protection switch or the lower shell 12 of such was shown, because herein is a particularly preferred application of the lift clamp 1. However, it can nevertheless be used in electrical appliances of any type, that is to say, for example, in the case of a residual current circuit breaker, arrester isolating switch, staircase automaton, etc.

The lift clamp 1 has, as previously known screw terminals of this type, a frame 14 which is in the in Fig. 1 Viewed position is rectangular. It usually consists of a one-piece, three times 90 ° angled copper strip. This frame 14 is immovably held in the housing, which can be achieved for example by clamping between projections on the lower shell inner wall.

Second main component of a lift clamp 1 is the box 15, which is also frame-like (see also Fig.2 ). The box 15 is rotated by 90 ° relative to the frame 14 and hung in this, ie, the upper portion 150 of the box 15 is located between the upper portion 140 and the lower portion 141 of the frame 14. The box 15 is thus slidably guided in the frame 14 ,

The third main component of the lift clamp is the clamping screw 16. The upper portion 140 of the frame 14 has an opening 142 through which the clamping screw 16 is freely rotatably guided. In the upper portion 150 of the box 15, a thread 152 is incorporated, in which the clamping screw 16 engages. If the clamping screw 16 is rotated in the closing direction (ie clockwise when the clamping screw 16 is designed as a right-hand screw), the box 15 is lifted, ie moved in the direction of the upper frame section 140. This shift is due to the fact that the clamping screw 16 with its foot-side end on the lower frame portion 141 or with its head 160 on the upper frame section 140 comes to rest. Continued inward turning of the clamping screw 16 into the box thread 152 can thus not lead to displacements of the clamping screw 16 downwards, but only to a lifting of the box 15.

If the clamping screw 16 in the opening direction (ie counterclockwise when the clamping screw 16 as a right-hand screw) is rotated, the box 15 is lowered, i. moved toward the lower frame section 141.

Such a lift clamp 1 has two points at which electrical lines can be clamped. On the one hand, feed lines can be introduced into the space 17 lying between the lower frame section 141 and the lower box section 151 and, on the other hand, into the space 18 lying between the upper frame section 140 and the screw head 160 (cf. Fig.2 ). When tightening the clamping screw 16, both the lower portions 141 and 151 of the frame 14 and the box 15 against each other and the screw head 16 pressed against the upper frame portion 140 while the introduced into the spaces 17 and 18 lines clamped.

As a rule, 17 lead wires are inserted into the space lying between the lower frame section 141 and lower box section 151 and inserted into the space 18 located between the upper frame section 140 and screw head 16 a terminal lug of a busbar system. In order to keep these two rooms 17, 18 accessible for insertion of these electrical lines, openings 19 and 20 are provided in the housing at the level of these spaces.

In connection with the insertion of a lead wire in the lower space 17 there is, in particular when the clamp is not opened wide enough, i. the lower portion 150 of the box 15 is too close to the lower portion 141 of the frame 14 - the problem that this wire, although passed through the opening 19, but then mistakenly placed not in the space 17, but under the box 15. A proper pinching this wire is then no longer possible.

In order to prevent such mis-insertion of the lead wire, a tab 24 is fixed to the box 15, which extends normal to the lower portion 151 of the box 15 and extends away from it, that is, in the lying below the box 15 space. This flap 24 thus extends parallel to the plane of the opening 19 and is disposed immediately adjacent thereto.

Due to its connection with the box 15, the flap 24 is displaced together with the box 15 and thus covers the lying below the box 15 portion of the opening 19. A through this opening 19 inserted therethrough wire can only in between the lower frame portion 151th and lower box portion 141 lying space 17 are used, an above-described erroneous insertion of a wire under the box 15 is reliably avoided.

The tab 24 may be structurally arbitrary: it can be made of an insulating material, such as. Be formed plastic, which brings the additional advantage that the flap 24 can be safely touched even when its terminal is energized, which may be the case, for example, if already a live conductor is connected to the other terminal.

In the in the Fig.1-4 illustrated embodiment, a parallel to the lower box section 151 extending plate 25 is formed on the tabs 24, via which the tab 24 is connected to the box 15. The plate 25 may be glued or welded to the lower box section 151, for example.

According to the embodiment of the Fig.1-4 The connection between the plate 25 and the lower box section 151 is achieved by a mounting plate 26, which is integrally formed on the plate 25 and normal to both this plate 25 and the flap 24. This mounting plate 26 is fixedly connected to a side wall of the box 15, which could be realized again by gluing or welding of these two parts.

A preferred used and therefore also in the Fig.1-4 illustrated variant for fixing the mounting plate 26 on the box 15 provides a pin 27, which is integrally formed on the mounting plate 26. In the box side wall, an opening 28 is incorporated, in which this pin 27 engages, whereby a positive fastening of the mounting plate 26 and thus of the tab 24 is achieved on the box 15.

As already explained, the lift clamp 1 in question has two points, namely the spaces 17 and 18, for clamping electrical lines, normally in the lower space 17 wires and in the upper space 18, the terminal lug of a busbar system is used.

As a rule, it is so that only one type of line, so either a bus system terminal lug or a wire is connected to one and the same terminal.

When opening the clamp, the clamping screw 16 is not only rotated, but also pressed down with the screwdriver used for this purpose. This results in lift clamps, which have only the design features discussed so far, that the screw head 16 is always pressed against the upper frame portion 141 and the rotation of the clamping screw 16 only in a downward displacement of the box 15, i. is converted into an opening of the space 17. Only when the box 15 is moved completely down and comes in this position on the underlying housing part 29 to the plant, no further downward sliding of the box 15 can be done more. A still then exercised opening movement of the clamping screw 16 is converted into a post-upward displacement of the clamping screw 16, whereby the screw head 160 is lifted from the upper frame part 140 and the upper space 18 is opened.

When turning the clamping screw 16 in the closing direction of the first space 18 is closed, then the box 15 is raised until its lower portion 151 at the lower portion 141 of the frame 14 comes to rest and only then after further continued rotation of the clamping screw 16 in the closing direction of the Screw head 160 clamped pressed against the upper frame portion 140.

By this operation is conditional that then when a lift terminal 1 only a bus system terminal lug is to be connected, first the clamping screw 16 must be opened in its entirety and after insertion of the terminal lug in the room 18 must be fully closed again.

It is intended to remedy this, a time-consuming assembly process-related circumstance that the box 15 of the lift clamp 1 in the frame 14 is not held free, but slidably against a resistance. This resistance can be realized in different ways:

Thus, for example, the box 15 rub against the frame 14 or on parts of the housing. The resulting static friction between the box 15 and the frame 14 or the housing parts initially prevents the above-discussed displacement of the box 15 relative to the frame 14, bringing the clamping screw 16 when rotating in the opening direction Box 15 and frame 14 out or when turning in the closing direction in box 15 and frame 14 moves into it. The (friction) resistance is dimensioned so that it can be overcome, for example by exerting a pressure on the screw head 160. This allows that upon rotation of the clamping screw 16 - if desired - immediately the lower space 17 can be opened.

When in Fig.1 shown embodiment of the housing is above the screw head 160, a rib 30 into which a bore 31 is inserted. This bore 31, which serves for the passage of the screw driver necessary for rotating the clamping screw 16, has a smaller diameter than the head 160 of the clamping screw 16.

When moving upwards the clamping screw 16, which then takes place during rotation in the opening direction, if not at the same time a pressure on the clamping screw 16 is exerted, the screw head 160 comes to rest on the rib 30. If the clamping screw 16 now continues to be rotated in the opening direction, the box 15 is pressed downwards, since the clamping screw 16 can no longer move upwards. The resistance is overcome and moved the box 15 down.

The resistance can - as in Figure 5 shown realized by means of a spring 32 which biases the box 15 in the direction of the frame 14. This spring 32 can do so by a leaf spring or -so as in Figure 5 explicitly represented by a helical compression spring which is located below the box 15 and at one end on the housing part 29 and the other end -unter mediation of the plate 25, if one is provided- at the lower portion 151 of the box 15 is supported.

There may be several variants of the realization of the resistor at the same time, for example, the box 15 may be mounted on both the frame 14 and the housing rubbing or it may be in addition to the frictional mounting of the box 15 on the frame 14, a spring 32 may be present.

As can be seen from these discussions of the function of the resistor, such or necessary for its realization components can be independent of a flap 24, i. even if such a tab 24 is missing, be provided. If there is a tab 24, the resistance can be realized by friction bearing this tab 24 in the housing 12.

The previously discussed possibilities of realizing the resistor have in common that they constantly exert this resistance, ie that this resistance is not significantly changed by displacements of the box 15.

In a preferred embodiment of the invention, a shear pin 33 is provided which is secured in the housing. The shear pin 33 is positively connected to the box 15, when this in the in Fig.1 and Figure 6 is shown position. This can be achieved, for example, by engaging the shear pin 33 in an aperture made in the box sidewall, or by placing the shear pin 33 just below the lower box portion 151, as in FIG Figure 6 shown.

Upon rotation of the KJemmschraube 16 in the opening direction of the shear bolt 33 initially any displacement of the box 15 is prevented, the rotational movement is implemented exclusively in an upward-wandering of the clamping screw 16. If a sufficiently large, extending in its longitudinal direction compressive force exerted on the clamping screw 16 (for example, by a blow to the clamping screw 16 or further rotation of the clamping screw 16, when the head 160 is already applied to the rib 30), the shear pin 33 is sheared off and the Box 15 can now be moved completely free.

In this variant of the realization of the resistance of this is only temporarily, namely exercised only before shearing the shear bolt 33.

With intact shear bolt 33 only the space 18 is opened or closed, so that the terminal lug of a busbar system connected with little effort can be connected to the lift clamp 1.

In the preferred and in the drawings Fig.1-4 embodiment shown in more detail is also such a shear pin 33 is provided, which, however, is only indirectly connected to the box 15:

In this embodiment, as already explained in more detail above, a tab 24 is provided, on which a small plate 25 is formed, with which the mounting plate 26 is integrally formed. This mounting plate 26 is slidably mounted in a, recessed into the housing rectangular guide groove 34 in the direction of displacement of the box 15 parallel direction. To connect the mounting plate 26 with the box 15, an integrally formed on the mounting plate 26 pin 27 is provided, which engages in an incorporated in the box side wall opening 28.

The shear pin 33 is integrally formed on the bottom of this guide groove 34. The mounting plate 26 has an opening 35, in which the shear pin 33rd engages (cf. Fig.2 . 3 ). The shear pin 33 is indirectly, namely connected by the intermediary of the mounting plate 26 and the pin 27 with the box 15.

In order for a compressive force exerted on the clamping screw 16 to actually effect only a shearing of the shear pin 33, but not of the pin 27, the shearing strength of this pin 27 is correspondingly greater than that of the shear pin 33.

The shear pin 33 has in this embodiment, the secondary function that he the mounting plate 26 and with this the tab 24 during assembly of the switch, i. when inserting the individual components in the housing lower shell, holds in the correct position. The mounting plate 26 with molded plates 25 and tabs 24 can thus be used by machine in the lower shell, frame 14 and box 15 of the lift clamps 1 can then be placed without difficulty on the mounting plate 26.

Claims (2)

1. A lifting clamp (1) for installation in a housing of an electrical device such as e.g. a circuit breaker, comprising a rectangular frame (14) and a rectangular box (15) whose upper section (150) is arranged between the upper section (140) and the lower section (141) of the frame (14), by means of which the box (15) is held in the frame (14) such that it can be moved; furthermore comprising a clamping screw (16) that is guided through a perforation (142) incorporated in the upper frame section (140) such that it can freely rotate, and engages in a thread (152) incorporated in the upper section (150) of the box (15); furthermore a tab (24) fixed on the box (15), which extends away from the lower section (151) of the box (15) into the space located underneath the box (15) and runs parallel to the plane of an opening (19) in the housing adjacent to the lifting clamp (1), wherein a platelet (25) running parallel to the lower box section (151) is formed on the tab (24), by means of which the tab (24) is connected with the box (15), and wherein a mounting platelet (26), running normal to both the platelet (25) and also the tab (24), is formed on the platelet (25), which mounting platelet (26) is securely connected with a sidewall of the box (15), characterised in that a perforation (35) is incorporated into the mounting platelet (26), into which a shearing pin (33) fixed in the housing can engage.
2. The lifting clamp (1) according to Claim 1, characterised in that a pin (27) is formed on the mounting platelet (26), which engages in a perforation (28) incorporated into the box sidewall.

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