ES2290273T3 - AUXILIARY FASTENING ELEMENT. - Google Patents

Abstract

Support clip (1) to be mounted in a housing of an electrical appliance, such as a duct 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), also comprising a clamping screw (16) , which is guided in a freely rotating manner through a perforation (142) made in the upper frame segment (140) and which engages in a thread (152) practiced in the upper segment (150) of the box (15), wherein the box (15) is held against a resistor in a movable way in the frame (14), characterized in that the resistance is formed by a shear pivot (33), fixed in the housing, preferably formed integrally with the housing and which is connected together Tiva form the box (15).

Description

Auxiliary clamping element.

The invention relates to a clamp of lift to mount in a housing of an electrical appliance, such as a duct protection switch, which It comprises a rectangular frame and a rectangular box, whose upper segment is arranged between the upper segment and the lower segment of the frame, so that the box is held by movable shape in the frame, also comprising a clamping screw, which is guided freely rotatable to through a perforation in the frame segment superior and that gears in a thread practiced in the segment top of the box, where the box is held against a resistance movable in the frame.

In the case of support clamps of this type can be tightened electrical conduits in two points, precisely between the lower segments of the frame and the box (lower housing chamber) as well as between the segment upper frame and tightening screw head (chamber of superior accommodation).

When turning the tightening screw in the direction of opening the box is first moved down and with it opens The lower housing chamber. Only when the box has reached its lowest position, in which it makes contact with a part of housing, the tightening screw is moved up as the opening movement continues and with it the chamber of superior accommodation.

When tightening the tightening screw, it must turn first until the lower case segment makes contact  with the lower frame segment, and only after it is transformed the rotating movement of the tightening screw in the direction of closure in an application with screw head tightening on the upper segment of the frame, or on an electrical conduit located between this upper segment and the screw head.

If the camera is used exclusively upper housing, to open this frame or to tighten a electrical conduit in this chamber it is necessary to turn the tightening screw, so that the time consumption to connect electrical conduits to the lift clamp is relatively high. A connection clamp of this type with tightening boxes is know for example of document EP 0 168 596 A. Also of EP 0 905 839 a support clamp can be deduced from this type.

Now we also know support clamps, in which a resistance against which you can move one of the tightening boxes, in order to reduce the time consumption to connect electrical conduits to lifting clamps. In the case of documents DE 195 13 281 A, DE 2 107 218 A and EP1 028 489 A are known for example connection or lift, in which the resistance, with which Holds a scrollable box in the frame, it materializes in each case by a spring. In EP 0 280 672 A, executes a resistance of this type by rubbing the box on parts of the housing.

In this state of the art there is the inconvenience that resistance, against which it can move the box in the rack, it could expire in a non- intentional, and with it the chamber of prematurely lower housing.

The mission of the present invention is to avoid this inconvenience and indicate a clamp of tightening of the class cited at the beginning, in which when turning the tightening screw in the opening direction firstly the camera remains open accommodation located between the upper segment and the head of screw, but the lower housing chamber closed provisionally. The lower housing chamber should only be able to open by taking special measures, such as by example exerting a greater force on the screw, for this way to avoid displacement especially safely unnoticed from the box.

This is solved according to the invention by means that the resistance is formed by a pivot of shear, fixed on the housing, configured with preference of integral form with the housing and which is connected in positive union of Shape to the box.

If during the turning of the tightening screw it is not apply a great force, that is to say no more force than essential to turn a screw, this resistance prevents First a shift of the box. The movement of screw opening is completely transformed into an elevation of The screw head from the upper frame segment, is that is, in an opening of the upper housing chamber. This allows, even after an insignificant turn of the screw tighten in the opening direction, insert a connection terminal of a channeling system in the upper housing chamber and tighten it there reliably, by turning insignificant tightening screw in the closing direction.

In the case of overcoming the resistance, by example by applying a pressure on the screw tighten, the resistance can be overcome, the box can move towards below and thereby open the lower housing chamber. In special by means of the shear pivot is avoided first place any type of displacement of the box against the frame, which avoids a particularly safe inadvertent displacement of the box. However, after shear bolt shearing can take place a displacement of the box and with it an opening of the chamber of lower housing.

It would also be possible for resistance it was configured by a spring located below the box, such as a coil spring, which pretends the box in the frame address.

The force of a spring is reduced only in a way very insignificant over time or if compressed with frequency, especially less than the friction forces that prevail between two construction pieces that make mutual contact with friction in the case of frequent friction movements. This resistance execution variant presents with it, respect to the variants that are based on the friction of two pieces constructive, the advantage of a longer life.

The resistance could also be formed by the friction of the flap on parts of the housing. Also here it turns out to be advantageous that to configure the resistance only use constructive parts available anyway and, in this mode, separate construction pieces and the technical complexity linked to its manufacture and assembly.

In an improvement of the invention it can be provided that the support clip comprises a flap immobilized on the box, which extends from the segment bottom of the box to the chamber below the box and runs parallel to the plane of an opening in the housing located adjacent to the support clip, and that on the flap is formed a insert that runs parallel to the lower case segment, by means of which the flap is attached to the box. The drilling segment located below the cash segment is thus covered, thereby avoiding wrong insertion of ducts under the box segment lower. The insert makes a relatively large contact possible  surface with the box and thus ensures a secure bond. Tightening clamps with flaps or closing screens are known for example, EP 0 559 585 A and US 5 580 285 A. Ha proved to be negative in EP 0 559 585 A that the flange shown there is fully configured with the box metallic, and thus do not offer electrically protection insulating. US 5 580 285 A, on the other hand, shows in a special form of execution a removable closure screen. This closing screen is however fixed at will with small hooks to the box, so that the reduced joint surface resulting does not guarantee a secure union.

In relation to this can be planned also that on the plaquita is formed a plaquita of assembly, which runs both perpendicularly with respect to it and perpendicular to the flap, which is fixedly attached to a side wall of the box.

In a further configuration of the invention it can be provided that the mounting plate is formed a pin, which engages in a perforation practiced in the side box wall.

In this way the box of a especially simple way, linked to technical complexity reduced, precisely by simple placement of the box on the mounting plate, on it.

In relation to this, it can also be provided that a hole is drilled in the mounting plate, in which meshes an immobilized shear bolt in the Case.

By this arrangement of the bolt of shearing it can fulfill, apart from its main function of the provision of a resistance against displacement of the box, the auxiliary function of clamping plates assembly, inserts and flaps in the housing. In the case of mounting the switch components in the housing can be inserted with this mechanically mounting plates, inserts and flaps in the bottom wrap.

The invention is described in more detail. referring to the attached drawings, in which they have been described especially preferred embodiments. With that show:

fig. 1 the plan view on a duct protection switch equipped with tweezers lift 1 according to the invention, with the upper envelope extracted;

fig. 2 the bottom switch wrapper duct protection equipped only with a clamp lift 1 according to fig. 1, on the ground floor, where the second lift clip 1 has been shown located outside the bottom wrap;

fig. 3 a plan view on a bottom wrap of duct protection switch equipped only with the right 1 lifting clamp to fig. 1, where in the region of the support clamp on the left there is a flap 24 that can be immobilized on the case 15 of the support clip 1;

fig. 4 shown in fig. 3 in one plane oblique;

fig. 5 a plan view on a clamp lift 1 according to the invention mounted in a housing, in where the resistance, against which the box can move 15 of the clamp 1, is formed by a compression spring helical 32 and

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

Duct protection switch depicted in fig. 1 comprises two threaded clamps 1 conforming to the invention, executed as so-called "tweezers of lift ", by means of which cables can be connected duct as well as the comb-type connection terminals of channeling systems to the protection switch.

The protection switch further comprises a overload activation element 2 as well as a device short circuit activation 3, together with a control mechanism 4 that you can move the mobile contact 5, from a closed position in the that the mobile contact 5 makes contact with the fixed contact 8, until the open position shown in fig. one.

The current to be monitored crosses in this protection switch, starting from the right threaded clamp 1, First, the overload activation element 2 reaches via a mobile conductor cable 6 and the switching bridge 7, to mobile contact 5, then through fixed contact 8 to short circuit activation device 3 and then to the second connection clamp 1.

The control mechanism 4 can be operated by means of the short-circuit activation device 3 or by the overload activation element 2. The device short circuit activation 3 is formed in a manner known in itself by an electromagnet coil with mobile induced, induced which impacts on the switching bridge 7 of the control mechanism 4 in the case of short circuit currents correspondingly high.

The overload activation element 2 is It consists of a bimetallic strip, which is heated by the current to watch. The first end 21 of the bimetallic strip it is immobilized in the protection switch housing, and the second end 22 is held with free movement. The flexing of bimetal caused by heating it 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 stirrup 9 acting on the seat of jack 36, drag it in the direction of movement and activate by means of this a response of the control mechanism 4.

Switching bridge 7 is prestressed by a spring 10 in the direction of the open position of the mobile contact 5. The insignificant detours explained from the seat of jack 36 because of the armature of the activation device of short circuit 3 or because of the overload activation element 2, through stirrup 9, are intensified by this spring 10 for the complete tilting of the switching bridge 7 to the open position of the mobile contact 5.

To connect the protection switch, it is that is, to swing the contact support 7 back to the closed position of the mobile contact 5 a lever 11 is provided, It can be handled by hand and is accessible from outside.

The protection switch housing has in two ways known in itself, and it consists of the bottom wrap 12, visible in each case in the figures of the drawing, and of a top envelope not represented in the drawings, symmetrical in its constructive execution to the lower envelope 12.

The present invention relates to the tweezers of lift 1 and is not limited to the use of these clamps lift 1 in conduit protection switches. In the drawings has only been represented by a switch of duct protection or bottom wrap 12 of one of them, since there is an especially preferred field of application here of the support clip 1 according to the invention. This can be used however, regardless of that, in appliances electric of any kind, that is for example in switches FI protection, shunt disconnectors, automatic box of stairs, etc.

The lifting clamp 1 according to the invention thus presents, like the threaded tweezers of this type known so far, a frame 14 that is rectangular according to it is contemplated in the position represented in fig. 1. It is composed almost always a strip of whole copper, layered three times in 90º. This frame 14 is immovably held in the housing, what can be achieved for example by pressing between conformations on the inner wall of lower wrap.

The second main constructive piece of a lift clip 1 is box 15, which is also configured as a frame (see also fig. 2). Box 15 is rotated 90º with respect to the frame 14 and suspended from it, that is, the upper segment 150 of the box 15 is located between the upper segment 140 and lower segment 141 of frame 14. The box 15 is thus guided in a movable way in the frame 14.

The third main constructive piece of the support clamp is the clamping screw 16. The segment upper 140 of the frame 14 has a perforation 142, through from which the tightening screw 16 is guided freely swivel In the upper segment 150 of box 15, made a thread 152, in which the tightening screw engages 16. If the clamping screw 16 is turned in the closing direction (that is, clockwise in the case of the execution of the clamping screw 16 as a right hand screw), the box is raised 15, that is, moves in the direction of the frame segment superior 140. This displacement is verified by it, because the clamping screw 16 with its lower end becomes seated on the lower frame segment 141 or with its head 160 over the upper frame segment 140. A progressive turn additional of the clamping screw 16 into the thread of box 152 cannot lead to a displacement of the Tightening screw 16 down, but only at an elevation of the box 15.

If the tightening screw 16 is turned on the sense of openness (that is, against the clockwise direction in the case of an execution of the tightening screw 16 as screw a right), box 15 sinks, that is, it moves in the direction of the lower frame segment 141.

A support clip 1 of this type It has two points where ducts can be tightened electric On the one hand, ducts of power in chamber 17, located between the frame segment lower 141 and lower case segment 151, and on the other hand in the chamber 18 located between the upper frame segment 140 and screw head 160 (see fig. 2). When tightening the screw of tightening 16 the segments are pressed both mutually lower 141 and 151 of frame 14 and box 15 as the head screw 160 against the upper frame segment 140 and, with this, the conduits introduced in the chambers 17 are tightened and 18.

Cable ducts are almost always inserted into the chamber 17 located between the lower frame segment 141 and the lower case segment 151 and, in the chamber 18 located between the upper frame segment 140 and screw head 160, a connection terminal of a pipeline system. To maintain accessible these two cameras 17, 18 for an insertion of these electrical conduits, openings 19 and 20 are provided in the housing at the height of these cameras 17, 18.

Regarding the insertion of a cable duct in the lower chamber 17 there is the problem - in especially if the clamp is not open enough, that is, the lower segment 151 of box 15 is located too close of the lower segment 141 of the frame 14 - that this cable, although it is guided through the opening 19, it is then placed by error not in camera 17, but under box 15. Then it is no longer proper tightening of this cable is possible.

To prevent such an incorrect insertion a flap has been immobilized in the box 15 with a flap 24, which runs perpendicular to the lower segment 151 of the box 15 and runs away from it, that is, in the chamber located below box 15. This flap 24 runs along it. parallel to the plane of the opening 19 and is arranged directly next to it.

Because of its connection to the box 15, the flap 24 together with box 15 and thereby cover the segment of the opening 19 located below the box 15. A cable plugged through this opening 19 can only be inserted from this mode in chamber 17, located between the frame segment lower 151 and lower case segment 141, avoiding reliably a previously described erroneous insertion of a cable under the box 15.

The flap 24 may be executed constructively in any way: it could be executed by example in full with box 15, for example by means of which curves from the same strip of conductive sheet that is box 15. However, it can also be a constructive piece separated from box 15 and fixedly attached to box 15 - for example welded or glued This can also be formed by a insulating material, such as synthetic material, which provides the additional advantage that contact can be made without problems with flap 24 itself, if tension is applied to your clamp, which is for example the case if the other clamp has already been connected A conductor that conducts tension.

In the case of the form of execution represented in figures 1-4 it has been shaped on the flap 24 a insert 25 that runs parallel to the box segment bottom 151, through which the flap 24 is attached to the box 15. Insert 25 may be glued or welded for this, by example, to the lower case segment 151.

According to the form of execution of the figures 1-4 the union between insert 25 and the segment of lower case 151 by means of a mounting plate 26, which is formed on insert 25 and that runs perpendicularly both this insert 25 and the flap 24. This insert assembly 26 is fixedly attached to a side wall of the box 15, what could be materialized again by gluing or welding These two pieces.

A variant preferably used and therefore also represented in figures 1-4 for immobilizing the mounting plate 26 on the box 15 provides a pin 27, which is formed on the mounting plate 26. In the side wall of the box has been perforated 28, in the that gears this pin 27, whereby a fixation is achieved in positive connection of the mounting plate shape 26 and with it flap 24 to box 15.

As already explained, the clamp 1 in question it has two points, precisely cameras 17 and 18, for tightening electrical conduits, where normally insert 17 conduit cables into the lower chamber and into the chamber upper 18 the connection terminal of a system canalization.

It almost always occurs with it that at one and the same clamp only one type of conduit is connected, it is that is, a pipeline system connection terminal or a cable of driver

When opening the clamp, with the screwdriver used for this not only the tightening screw 16 is turned, but which is also pressed down. This leads, in the case of support clamps that have only the characteristics constructive treated so far, that the screw head 160 is always pressed against the upper frame segment 140 and the rotation of the clamping screw 16 is transformed exclusively into a shift down from box 15, that is, in a camera opening 17. Only when case 15 has moved totally down comes to make contact in this position with the housing part 29 located below it, can no longer there is a further downward movement of the box 15. A opening movement of the clamping screw 16 which follows exercising becomes an upward displacement of the clamping screw 16, so that the screw head 160 is lifts from the upper frame part 140 and the chamber is opened top 18.

By turning the clamping screw 16 in the direction the chamber 18 is closed first, then the box is raised 15 until its lower segment 151 comes into contact with the lower segment 141 of frame 14 and only if followed later with the progressive rotation of the clamping screw 16 in the direction of closure screw head 160 is pressed, with tightening, against the upper frame segment 140.

Through this mode of operation it is forced that later, when a support clamp 1 only wants connect a pipeline system connection terminal, in First, the clamping screw 16 must be fully opened and, after inserting the connection terminal into chamber 18, close again completely.

In accordance with the invention it is intended to eliminate this circumstance, which requires an assembly process that it consumes time, that the case 15 of the support clip 1 is hold on frame 14, not freely without scrollable Against a resistance. This resistance can materialize from different ways.

In this way for example the box 15 can make friction contact with frame 14 or parts of the Case. The adhesive friction obtained with it between the box 15 and the frame 14 or the housing parts prevents first place the previously treated displacement of the box 15 with with respect to the frame 14, whereby the tightening screw 16 to turn in the opening direction moves out of the box 15 and of the frame 14 or, when turning in the direction of closing, towards inside box 15 and frame 14. The resistance (of friction) is sized so that it can be overcome, by example by exerting a pressure on the screw head 160. This allows, when turning the tightening screw 16 - whenever desired - the lower chamber 17 can be opened immediately.

In the case of the execution example of the housing shown in fig. 1 is above the head screw 160 a rib 30, in which a drill has been made 31. This drill 31, which serves to guide through it the screwdriver needed to turn the tightening screw 16, has a smaller diameter than head 160 of the clamp 16.

During the upward movement of the clamping screw 16, which occurs when turning in the direction of opening when there is no pressure on the tightening screw 16, screw head 160 gets to do contact with the rib 30. If the clamping screw 16 is turned now also in the direction of opening the box 15 - since the tightening screw 16 cannot move further upwards. The resistance is overcome with this and the box 15 is scroll down.

The resistance may be materialized - as It has been represented in fig. 5 - by means of a spring 32 which press box 15 in the direction of frame 14. This pier 32 it can be formed for this by a leaf spring or - as has been explicitly represented in fig. 5 - by a dock of helical compression, which is located below box 15 and it rests on one end on the housing part 29 and on the other extreme - through insertion of insert 25, provided that it is planned one - in the lower segment 151 of box 15.

Several may be available at the same time variants of resistance materialization, for example the box 15 can be mounted with friction on both the frame 14 as on the housing, or a spring 32 may be available in addition to the mounting with friction of the box 15 on the frame 14.

As it follows from these explanations of resistance operation, parts may be provided constructive of this type or necessary for its materialization with independence of a flap 24, that is, also if a missing flap 24 of this type. If a flap 24 is available, the resistance can be materialized by mounting with friction of this flap 24 in the housing 12.

The possibilities discussed so far of the resistance materialization have in common that they exert constantly this resistance, that is, that this resistance does not it is fundamentally modified by moving the box fifteen.

In the case of a preferred embodiment of the invention a shear bolt 33 is provided, which It is fixed to the housing. The shear bolt 33 is attached in positive junction of form to box 15, when it is in the position represented in figures 1 and 6. This may be achieved for example by means of the shear bolt 33 engages in a perforation in the side wall of box or by arrangement of the shear bolt 33 just below the lower case segment 151, as has been depicted in fig. 6.

By turning the clamping screw 16 on the opening direction is prevented by the shear bolt 33 first of all any displacement of the box 15, to then the rotating movement is transformed into a upward movement of the clamping screw 16. If exercised a sufficiently large pressure force, which runs in its longitudinal direction, on the tightening screw 16 (for example by hitting the tightening screw 16 or following turning the clamping screw 16, when the head 160 already does contact with the rib 30), the shear bolt 33 is sheared and the box 15 can now move completely free.

In the case of this variant of the resistance materialization is exercised only temporarily, precisely just before shearing the bolt of shear 33.

In the case of a shear bolt 33 intact only chamber 18 is opened or closed, as soon as the terminal connection of a pipeline system can be connected to the support clamp 1, coupled with a screwed-in complexity reduced

In the case of the preferred embodiment and represented in more detail in the drawings of the figures 1-4 a bolt of shear 33 of this type, but which has been attached to box 15 simply indirectly.

In the case of this form of execution, planned - as explained above - a flap 24 on which a plate 25 was formed, with which it has been fully configured mounting plate 26. This mounting plate 26 is mounted in a guide groove 34 rectangular practiced in the housing, so that it can move in a direction parallel to the direction of displacement of the box 15. To join the mounting plate 25 a the box 15 is provided a pin 27 formed on the mounting plate 26, which engages in a perforation 28 performed on the side wall of the box.

The shear bolt 33 is shaped with this on the bottom of this guide groove 34. The insert of assembly 26 has a bore 35, in which the bolt engages shear 33 (see figures 2, 3). Bolt shear 33 is indirectly linked thereto precisely by means of mounting plate 26 and pin 27, to the box fifteen.

So that here a pressure force exerted on the tightening screw 16 really only produce a shear of shear bolt 33, but not of pin 27, the shear strength of this pin 27 must be designed correspondingly larger than that of the bolt shear 33.

The shear bolt 34 has in this I execute the secondary function of holding the mounting plate  26 or with it the flap 24 during the assembly of the switch, is say, by inserting the different construction pieces in the lower housing wrap, in the correct position. The insert assembly 26 with insert 25 and flap 24 shaped can thereby mechanically inserted into the lower envelope, and the frame 14 and the case 15 of the support clamps 1 can be placed later without difficulty on the mounting plate 26.

Claims (5)

1. Support clip (1) for mounting in a housing of an electrical appliance, such as a duct 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 movable in the frame (14), also comprising a clamping screw ( 16), which is guided in a freely rotating manner through a perforation (142) made in the upper frame segment (140) and which engages in a thread (152) practiced in the upper segment (150) of the box (15) ), wherein the housing (15) is held against a resistance in a movable way in the frame (14), characterized in that the resistance is formed by a shear pivot (33), fixed in the housing, preferably configured as integral form with the housing and which is joined in union p box-shaped ossifying (15). 2. Lift clip (1) according to claim 1, characterized in that the lift clip (1) comprises a flap (24) immobilized on the box (15), which extends from the lower segment (151) of the box ( 15) to the chamber located below the box (15) and runs parallel to the plane of an opening (19) in the housing adjacent to the support clip (1), and because 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). 3. Lift clip (1) according to claim 2, characterized in that a mounting plate (26) is formed on the insert (25), which runs both perpendicularly to it and perpendicularly to the flap (24), which is attached fixedly to a side wall of the box (15). 4. Support clip (1) according to claim 3, characterized in that a pin (27) is formed on the mounting plate (26), which engages in a hole (28) made in the side box wall. 5. Support clamp (1) according to claim 3 or 4, characterized in that a perforation (35) is made in the mounting plate (35), in which a shear bolt (33) immobilized in the housing engages.