ES2372759T3 - LIFT TERMINAL. - Google Patents

Abstract

Lifting terminal (1) for installation in a housing of an electrical device, such as a line protection switch, comprising a rectangular frame (14) and a rectangular box (15), whose upper segment (150 ) is disposed between the upper segment (140) and the lower segment (141) of the frame (14), whereby the box (15) is movably held in the frame (14), further comprising a clamping screw ( 16) that, through a perforation (142) practiced in the upper frame segment (140), it is guided through freely rotating form and engages in a thread (152) practiced in the upper segment (150) of the box (15), also a flap (24) immobilized on the box (15), which extends away from the lower segment (151) of the box (15) in the space below the box (15) and runs in parallel to the plane of an opening (19) in the housing adjacent to the lifting terminal (1), where s The flap (24) is formed by a insert (25) that runs parallel to the lower box segment (151), by means of which the flap (24) is attached to the box (15) and where on the insert (25) a mounting plate (26) is formed, which runs both perpendicularly to it and perpendicularly to the flap (24) and which is fixedly attached to a side wall of the box (15), characterized in that in the insert The mounting (26) has been drilled (35), in which a shear pin (33) can be engaged, which can be immobilized in the housing.

Description

Draw terminal

The invention relates to a lifting terminal for installation in a housing of an electrical apparatus, such as a line protection switch, comprising a rectangular frame and a rectangular box, whose upper segment is arranged between the segment upper and lower segment of the frame, whereby the box is movable in the frame, which further comprises a clamping screw which, through a perforation in the upper frame segment, is guided freely through rotating and gears in a thread made in the upper segment of the box, also a flap immobilized on the box, which extends away from the lower segment of the box in the space below the box and runs parallel to the plane of a opening in the housing located adjacent to the lifting terminal, a insert being formed on the flap that runs parallel to the inflow box segment below, by means of which the flap is attached to the box and where a mounting plate is formed on the insert, which runs both perpendicularly to it and perpendicularly to the flap and which is fixedly attached to a side wall of the box.

The lifting terminals of this type with flaps or closing visors immobilized on the box are known for example from EP 0 559 585 A and US 5 580 285 A. In the case of EP 0 559 585 A it has proved to be an inconvenience the fact that the flange shown there is fully configured with the box and, thus, does not offer electrically insulating protection. US 5 580 285 A, on the other hand, shows in a special embodiment a removable closure visor. This closing visor is fixed, however, only with small hooks to the box, so that the resulting small intimate joint surface does not guarantee a secure connection.

Document DE 83 12 142 U1 describes a lifting terminal, which is movably held in a housing of an electrical apparatus, the box presenting a flap-shaped widening, which closes the space behind when closing the terminal. EP 772 256 A2 describes a terminal in which an insulating closure visor meshes, which is executed as a parallelepiped on which two mounting plates are formed, which engage in open recesses by the edge over the terminal by called heels. Document US 3 539 977 A describes a terminal with a moving box, from which a spring is suspended which, with the terminal closed, is raised by contact pressure and thus covers the space behind the terminal.

The mission of the invention is therefore to securely attach a flap to the box, to cover the lower housing space.

In accordance with the invention this is solved by means of a perforation made in the mounting plate, in which a shear pin which is immobilized in the housing can engage.

Through this arrangement of the shear bolt it can fulfill, apart from its main function of offering a resistance against a displacement of the box, the secondary function of holding mounting plates, plates and flaps in the housing. If the switch components are installed in the housing, mounting inserts, inserts and flaps can be inserted mechanically into the lower half-housing. The segment of the opening located below the lower box segment is covered by this, thereby preventing a wrong insertion of lines below the lower box segment. The insert makes possible a relatively large surface contact with the box and, thus, ensures a secure connection.

In a further configuration of the invention it can be provided, in this regard, that a pin that engages the perforation in the side box wall is formed on the mounting plate. In this way the box can be immobilized on the mounting plate in a very simple way, linked to a reduced technical complexity, precisely by simply placing the box on it.

The invention is described in more detail with reference to the accompanying drawings, in which especially preferred embodiments are shown. With this they show:

fig. 1 the plan view on a line protection switch equipped with lifting terminals 1, with the

upper half-shell removed;

fig. 2 the lower half housing of the line protection switch according to fig. 1, equipped only

with a draw terminal 1, in an oblique plane, where the second draw terminal 1 is represented

C located outside the lower half housing;

fig. 3 a plan view of a lower half housing of the line protection switch according to the

fig. 1, equipped only with the right lifting terminal 1, where in the region of the lifting terminal

on the left there is a flap 24 that can be immobilized on the housing 15 of the lifting terminal 1;

fig. 4 shown in fig. 3 on an oblique plane;

fig. 5 a plan view on a lifting terminal 1 installed in a housing, where the resistance, with

After which the box 15 of terminal 1 can move, it is formed by a compression spring heli

coidal 32 and

fig. 6 shown in fig. 5, where a shear bolt 33 formed on the inner housing wall is provided instead of the helical compression spring 32, in order to materialize the resistance.

The line protection switch shown in fig. 1 comprises two threaded terminals, executed as so-called "draw terminals", by means of which line wires as well as the comb-type connection terminals of bus systems can be connected to the protection switch.

The protection switch further comprises an overload trip element 2 as well as a short-circuit trip device 3, apart from this a ratchet mechanism 4 that can move the mobile contact 5 from a closed position, in which the mobile contact 5 makes contact with the fixed contact 8, to the open position shown in fig. one.

The current to be monitored flows in this protection switch, starting from the right threaded terminal 1, firstly through the overload trip element 2, arrives through a line cable 6 and the connection bridge 7 to the mobile contact 5, then through the fixed contact 8 to the short-circuit trip device 3 and finally to the connection terminal 1. The ratchet mechanism 4 can be operated both from the short-circuit trip device 3 and from the trip element by overload 2. The short-circuit trip device 3 is formed in a manner known per se by a magnetic coil with mobile armature, induced that in the case of correspondingly high short-circuit currents impacts on the connection bridge 7 of the ratchet mechanism Four.

The overload trip element 1 is composed of a bimetallic strip, which is heated by the current to be monitored. The first end 21 of the bimetallic strip is immobilized in the housing of the protection switch, the second end 22 is held with free movement. The flexing of the bimetal caused by the heating thereof therefore leads to a movement of the second end 22 in the direction of the arrow 23. In the case of sufficiently intense heating, the free end 22 of the bimetallic strip comes into contact during this movement with the stirrup 9 acting on the ratchet support 36, dragging it in the direction of movement and thereby triggering a response of the ratchet mechanism 4.

The connection bridge 7 is prestressed by a spring 10 in the direction of the open position of the movable contact 5. The insignificant explained deviations of the ratchet support 36 by the armature of the short-circuit trip device 3 or by the overload trip element 2, through the stirrup 9, are intensified by this spring 10 for the complete tilting of the connecting bridge 7 to the open position of the movable contact 5.

To connect the protection switch, that is to say to swing the contact support 7 backwards to the closed position of the movable contact 5, a lever 11 accessible from the outside and hand-operated is provided.

The housing of the protection switch is formed in a manner known per se by two parts, being composed of the lower half housing 12 which can be seen in each case in the drawing figures and by an upper half housing not shown in the drawings, symmetrical in relation to to its constructive execution.

The present invention relates to the lifting terminals 1 and is not limited to the use of these lifting terminals 1 in line protection switches. In the drawings, only a line protection switch or the lower half housing 12 of one of this type has been represented, because here there is an especially preferred application field of the lifting terminal 1. However, independently of this it can be applied to devices electrical of any type, that is, for example, to FI protection switches, disconnector disconnector switches, staircase circuit breakers, etc.

The lifting terminal 1 therefore has, like the threaded terminals known to date of this type, a frame 14 which is rectangular in the position shown in fig. 1. It is normally composed of a strip of whole copper layered three times in 90º. This frame 14 is held without the possibility of movement in the housing, which for example can be achieved by tightening between conformations on the inner wall of the lower half-shell.

The second main construction part of a lifting terminal 1 is box 15, which is also configured as a frame (see fig. 2). The box 15 is rotated 90 ° in relation to the frame 14 and suspended therein, that is, the upper segment 150 of the box 15 is located between the upper segment 140 and the lower segment 141 of the frame 14. The box 15 is guided therefrom. scrollable mode in the frame 14.

The third main construction piece is the clamping screw 16. The upper segment 140 of the frame 14 has a bore 142, through which the clamping screw 16 is freely rotatable guided. In the upper segment 150 of the case 15, a thread 152 has been made, in which the clamping screw 16 engages. If the clamping screw 16 is turned in the closing direction (ie clockwise, if the clamping screw 16 is executed as a right-hand screw), the box 15 is raised, that is to say it moves in the direction of the upper frame segment 140. This displacement is verified because the clamping screw 16, with its lower end, sits on the segment of lower frame 141 or with its head 160 on the upper frame segment

rior 140. A further progressive screwing of the clamping screw 16 on the housing thread 152 cannot therefore lead to displacements of the clamping screw 16 downwards, but only to an elevation of the box 15.

If the clamping screw 16 is turned in the opening direction (ie counterclockwise in the execution of the clamping screw 16 as a right-hand screw), the box 15 is lowered, that is, it moves in the direction of the segment of lower frame 141.

A lifting terminal 1 of this type has two positions in which power lines can be embedded. On the one hand, feeding lines can be introduced in the space 17 located between the lower frame segment 141 and the lower case segment 151 and, on the other hand, in the space 18 located between the upper frame segment 140 and the screw head 160 (see fig. 2). When the clamping screw 16 is pressed, both the lower segments 141 and 151 of the frame 14 and of the box 15 are pressed against each other, as well as the screw head 16 against the upper frame segment 140 and thereby the lines introduced are inserted in spaces 17 and 18.

In general, line wires are inserted in the space 17 located between the lower frame segment 141 and the lower box segment 151 and in the space 18, located between the upper frame segment 140 and the screw head 16, Insert a connection terminal of a bus system. To keep these two spaces 17, 18 accessible for the insertion of these power lines, openings 19 and 20 are provided in the housing at the height of these spaces 17, 18.

Regarding the insertion of a line wire in the lower space 17, the problem arises - especially if the terminal is not sufficiently open, that is, the lower segment 150 of the box 15 is located too close to the lower segment 141 of the frame 14 - that this thread, even though it is guided through the opening 19, is then not mistakenly placed in the space 17, but under the box 15. Afterwards, it is no longer possible to properly embed this thread.

In order to prevent a failed insertion of this type of line thread, a flap 24 is immobilized on the box 15 which runs perpendicularly to the lower segment 151 of the box 15 and extends away from it, that is, in the space below the box 15. This flap 24 then runs parallel to the plane of the opening 19 and is arranged directly next to it.

Because of its attachment to the box 15, the flap 24 travels together with the box 15 and, thus, covers the segment of the opening 19 located below the box 15. A wire plugged through this opening 19 it can only be inserted with it only in the space 17, located between the lower frame segment 151 and the lower box segment 141, thereby reliably preventing a previously described erroneous insertion of a thread under the box 15.

The flap 24 can be constructed constructively in any way: it can be formed in this way of an insulating material, such as synthetic material, which implies the additional advantage that the flap 24 itself can be touched later without danger if tension is applied to its terminal, which is for example the case if a conductive voltage line is already connected to the other terminal.

In the case of the embodiment shown in Figures 1-4, a plate 25 is formed on the flap 24 which runs parallel to the lower box segment 151 and through which the flap 24 is attached to the box

15. The insert 25 may be, for example, glued or welded to the lower case segment 151.

According to the embodiment of Figures 1-4, the connection between the insert 25 and the lower case segment 151 is achieved by means of a mounting insert 26, which is formed on the insert 25 and runs perpendicularly to both this insert 25 and to the flap 24. This mounting plate 26 is fixedly attached to a side wall of the box 15, which in turn could be materialized by gluing or welding these two pieces.

A variant for immobilizing the mounting plate 26 on the box 15, used in a preferred manner and therefore also shown in Figures 1-4, provides a pin 27 that is formed on the mounting plate 26. On the side wall of the box a perforation 28 is carried out in which this pin 27 engages, whereby a positive attachment is achieved in the form of the mounting plate 26 and with it from the flap 24 to the box 15.

As already explained, the lifting terminal 1 of which we are talking about has two points, precisely spaces 17 and 18, to embed power lines, where normally in the lower space 17 line wires are inserted and in the upper space 18 the terminal of connection of a bus system.

Normally it occurs with this that only one type of line is connected to one and the same terminal, that is,

or a bus system connection terminal or a line wire.

When opening the terminal with the screwdriver used for this, not only the clamping screw 16 is turned, but it is also pressed down. This leads, in the case of lifting terminals that only present the construction characteristics mentioned so far, to the screw head 16 being pressed continuously against the bast segment

upper dor 141 and the rotation of the clamping screw 16 is transformed only in a downward movement of the box 15, that is, in an opening of the space 17. Only when the box 15 has been completely moved down and in this position sits on the housing part 29 located below it, no further displacement can take place below the housing 15. An opening movement of the clamping screw 16, still exerted later, is transformed into an upward movement of the clamping screw 16, whereby the screw head 160 is raised from the upper frame part 140 and the upper space 18 is opened.

Turning the clamping screw 16 in the closing direction closes first the space 18, then the box 15 is raised until its lower segment 151 sits on the lower segment 141 of the frame 14 and, only if it continues later the rotation of the clamping screw 16 in the closing direction, the screw head 160 is pressed with tightening against the upper frame segment 140.

This mode of operation requires that afterwards, if a bus terminal 1 is only intended to be connected to a bus system connection terminal, the clamping screw 16 must first be opened completely and, after inserting the connection terminal into the space 18, have to close completely again.

In order to remedy this circumstance that requires a long assembly process, it is provided that the housing 15 of the lifting terminal 1 is not freely held in the frame 14, but in a movable way against a resistor. This resistance can materialize in different ways:

In this way, for example, the case 15 can make friction contact with the frame 14 or parts of the housing. The static friction that occurs between the box 15 and the frame 14 or the housing parts first prevents the aforementioned displacement of the box 15 relative to the frame 14, whereby the clamping screw 16 when rotating in the opening direction moves out of the box 15 and the frame 14 or, when turning in the direction of closing, into the box 15 and the frame 14. The friction resistance is sized so that it can be overcome , for example, by exerting pressure on the screw head 160. This allows, by turning the clamping screw 16 - whenever desired - the lower space 17 can be opened immediately.

In the exemplary embodiment shown in fig. 1 of the housing, above the screw head 160 is a rib 30, in which a drill 31 has been made. This drill 31, which serves to guide through it the screwdriver necessary to rotate the clamping screw 16 , has a diameter smaller than the head 160 of the clamping screw 16.

During the upward movement of the clamping screw 16, which occurs when turning in the direction of opening if no pressure is simultaneously exerted on the clamping screw 16, the screw head 160 sits on the rib 30. If the spindle is now rotated clamping screw 16 also in the direction of opening the box 15 is pressed down, because the clamping screw 16 can no longer move upwards. The resistance is overcome with this and the box 15 moves down.

The resistance can be realized by means of a spring 32 - as shown in fig. 5 - which presses the box 15 in the direction of the frame 14. This spring 32 may be formed by a leaf spring or - as explicitly shown in fig. 5 - by a helical compression spring, which is located below the case 15 and is supported by one end in the housing part 29 and the other end - by means of the insert 25, provided that one is provided - in the bottom segment 151 of the box 15.

Several variants of the materialization of the resistance can occur simultaneously, for example the box 15 can be frictionally mounted on both the frame 14 and the housing or, in addition to the friction installation of the box 15 on the frame 14, it can a spring 32 is present.

As can be deduced from the explanation of the operation of the resistance one can be provided in this way or construction pieces necessary for its materialization can be provided, independently of a flap 24, that is, also in the event that a flap 24 of this is missing kind. If a flap 24 is available, the resistance may be materialized by frictionally installing this flap 24 in the housing.

The possibilities so far mentioned of the materialization of the resistance have in common that they exert this resistance constantly, that is to say that this resistance is not essentially modified by the displacement of the box 15.

In the case of a preferred embodiment of the invention, a shear bolt 33 is provided, which is fixed in the housing. The shear bolt 33 is attached to the case 15 in positively shaped connection, when it is in the position shown in Figures 1 and 6. This can be achieved, for example, by means of the shearing bolt 33 engaging in a perforation. made in the side box wall, or by arrangement of the shear bolt 33 just below the lower box segment 151, as shown in fig. 6.

By turning the clamping screw 16 in the opening direction, the shear bolt 33 first prevents any displacement of the housing 15, and the rotating movement becomes only an upward displacement of the clamping screw 16. If it is exerted on the clamping screw 16 a sufficiently large pressure force, which runs in its longitudinal direction (for example by a blow on the clamping screw 16 or by continuing to turn the clamping screw 16, if its head 160 already makes contact with the rib 30), shear the shear bolt 33 and the box 15 can then move completely free from there.

In this variant of the materialization of the resistance it is only exerted temporarily, precisely only before the shearing of the shear bolt 33.

In the case of an intact shear bolt 33, only the space 18 is opened or closed, so that the connection terminal of a bus system can be connected to the lifting terminal 1 with a reduced screw effort.

In the preferred embodiment and shown in more detail in Figures 1-4, a shear bolt 33 of this type is also provided, which is however only indirectly attached to the case 15:

In this embodiment - as already explained in more detail above - a flap 24 is provided on which a insert 25 is formed, with which the mounting plate 26 is configured integrally. This mounting plate 26 is movably mounted in the direction parallel to the direction of travel of the box 15, in a rectangular guide groove 34 in the housing. To connect the mounting plate 26 to the box 15, a pin 27 is provided formed on the mounting plate 26, which engages in a hole 28 made in the side wall of the box.

The shear bolt 33 is thereby formed on the basis of this guide groove 34. The mounting plate 26 has a bore 35, in which the shear bolt 33 engages (see Figures 2, 3). The shear bolt 33 is indirectly connected to the housing 15, precisely by means of the mounting plate 26 and the pin 27.

So that here a pressure force exerted on the clamping screw 16 really only produces a shear of the shear bolt 33, but not of the pin 27, the shear resistance of this pin 27 must be sized correspondingly greater than that of the shear bolt 33.

In this embodiment, the shear bolt 33 has the secondary function of holding the mounting plate 26 in the correct position or with the same flap 24 during the assembly of the switch, that is, when inserting the different construction pieces in the lower half-shell of Case. The mounting plate 26 with shaped insert 25 and flap 24 can thus be mechanically inserted in the lower half-shell, while the frame 14 and the housing 15 of the lifting terminal 1 can then be placed without difficulty on the mounting plate 26.

Claims (2)

1. Lift-off terminal (1) for installation in a housing of an electrical device, such as a line protection switch, comprising a rectangular frame (14) and a rectangular box (15), whose upper segment 5 (150) is disposed between the upper segment (140) and the lower segment (141) of the frame (14), whereby the box (15) is movable in the frame (14), which further comprises a clamping screw (16) which, through a perforation (142) made in the upper frame segment (140), is guided through freely rotating form and engages in a thread (152) practiced in the upper segment (150) of the box (15), also a flap (24) immobilized on the box (15), which extends away from the lower segment (151) of the box (15) in the space below the box (15) and runs parallel to the plane of an opening (19) in the housing adjacent to the lifting terminal (1), in where on the flap (24) a insert (25) is formed that runs parallel to the lower box segment (151), by means of which the flap (24) is attached to the box (15) and where on the insert (25) is formed by a mounting insert (26), which runs both perpendicularly to it and perpendicularly to the flap (24) and which is fixedly attached to a wall 15 side of the box (15), characterized in that a perforation (35) has been made in the mounting plate (26), in which a shear pivot (33) can be engaged which can be immobilized in the housing. 2. Lift-off terminal (1) according to claim 1, characterized in that on the mounting plate (26) it is with formed a pin (27), which engages in a hole (28) in the side wall of the box. twenty