EP2355248A1 - Wire clamp - Google Patents

Abstract

The clamp has a body (10) with a tapped cylindrical cavity opened at an end of the body. Another end of the body is closed by a bottom part (12) having a hole (13) for passage of a screw (20) e.g. self-tapping or self-drilling screw. A threaded plug (30) is adapted to be helicoidally engaged in the tapping of the cavity to clamp a core of an electrical wire against bottom of through-slots of the body. The plug has a central through-hole (32) to allow passage of a tool (40) e.g. flat or cruciform screwdriver, for rotationally driving the screw to fasten the body onto a metal structure. An independent claim is also included for a method of placing a wire clamp.

Description

The present invention generally relates to wire clamps.

More particularly, the present invention relates to clamps suitable for grounding metal structures.

Wire clamps for grounding metal structures are adapted to be fixed to metal profiles in a conductive manner. They have clamping means for electrical connection to grounding wires. Such clamps are especially used for the grounding of metal structures such as, for example, modules of aluminum photovoltaic panels and their support frames.

To this end, wire clamps are known for grounding a metal structure comprising a body having a threaded cylindrical cavity opening at a first end of the body, the other end being closed by a bottom pierced with a hole for the passage for a screw or a bolt fixing the body to the metal structure.

The body has on a portion of the threaded cavity two through slots facing one another made according to two generatrices of the cylindrical cavity and opening at said first end. A threaded plug having a rotational drive footprint is engaged helically in the tapping of the cylindrical cavity to clamp a core of an electrical wire against the bottom of the slots.

This structure requires first inserting the screw or stud in the body of the clamp and then insert the body of the screw in a hole of the metal structure and tighten the screw against the metal structure, using , if necessary, a nut and possibly a washer. In the case of metal structures covered, for example, with an anti-rust layer, it is necessary to provide a fan-type washer to cross this layer to tighten to ensure good electrical contact.

In a second step, an electric wire is inserted into the slots and the screw cap screwed over.

The establishment of such a wire clamp requires handling and assembly of many parts, which is a waste of time for the installer, and increases the risk of losing items during handling.

The present invention aims to overcome these disadvantages. In a more general manner, the present invention aims to improve and make reliable the known wire clamps.

The present invention proposes for this purpose a wire clamp for grounding a metal structure having a body having a threaded cylindrical cavity opening at a first end of the body, the other end being closed by a bottom pierced with a hole for the passage of a fastening screw of the body on the metal structure, the body having on at least part of the threaded cavity two through slots facing each other formed along two generatrices of the cylindrical cavity and opening at said first end and a threaded plug having a rotational drive cavity and adapted to engage helically in the tapping of the cylindrical cavity for clamping a core of an electrical wire against the bottom of the slots, the plug having a central opening hole adapted to allow a rotating drive tool to pass for the body fixing screw on the structure m étallique.

Thus, advantageously, the wire clamp can be fixed on the metal structure by tightening the fixing screw without having to disassemble the plug. Thus, the plug will not be lost during the installation of the cable clamp. In addition, the central hole makes it easier to guide the clamping tool to a corresponding cavity in the screw head.

Thus, the screw is captive when the plug is in place. Advantageously, the screw being previously inserted into the corresponding hole and the cap screwed into the body, the latter can be fixed on the metal structure without having to remove the cap, which contributes to the reliability of the assembly and the ease of set up. In practice, the risk of losing an element of the cable clamp according to the invention during its installation is zero, since the screw is trapped in the body and the plug.

• le trou du fond du corps de serre-fil présente une forme conique s'élargissant vers l'extrémité débouchante du corps de serre-fil et la tête de vis présente une forme conique complémentaire.

According to an advantageous characteristic:

• the bottom hole of the clamp body has a conical shape widening toward the open end of the clamp body and the screw head has a complementary conical shape.

Thus, advantageously, the screw is centered and guided in rotation during its tightening on the metal structure to be connected.

• ladite vis est une vis auto-forante ou une vis auto-taraudante ;
• le bouchon présente deux encoches diamétralement opposées formant empreintes d'entraînement en rotation pour un tournevis plat ;
• au moins un des éléments suivants est réalisé en acier inoxydable : corps de serre-fil, bouchon, vis de fixation ;
• le corps de serre-fil présente une forme extérieure adaptée à coopérer avec un outil de blocage en rotation du corps du serre-fil ;
• ladite forme extérieure est une forme hexagonale sur une partie au moins de la hauteur du corps de serre-fil ;

According to advantageous characteristics, possibly combined:

• said screw is a self-drilling screw or a self-tapping screw;
• the plug has two diametrically opposed notches forming rotational drive cavities for a flat screwdriver;
• at least one of the following is made of stainless steel: clamp body, plug, fixing screw;
• the clamp body has an outer shape adapted to cooperate with a locking tool in rotation of the body of the clamp;
• said outer shape is a hexagonal shape over at least part of the height of the wire clamp body;

• présenter le serre-fil à une structure métallique à raccorder ;
• insérer un outil d'entraînement en rotation pour la vis de fixation du corps dans le trou central du bouchon ;
• visser la vis de fixation dans la structure métallique afin de fixer le serre-fil à la structure métallique à raccorder ;
• insérer un fil de mise à la terre dans les encoches ;
• serrer le bouchon fileté contre le fil à l'aide d'un outil d'entraînement en rotation adapté à engager le bouchon fileté.

In another aspect, the present invention relates to the implementation of a wire clamp comprising the steps of:

• present the wire clamp to a metal structure to be connected;
• insert a rotational drive tool for the body securing screw into the center hole of the plug;
• screw the fixing screw into the metal structure to fix the clamp to the metal structure to be connected;
• insert a ground wire into the notches;
• tighten the threaded plug against the wire using a rotating drive to fit the threaded plug.

• présenter le serre-fil à une structure métallique à raccorder ;
• mettre un outil de blocage en rotation sur la forme extérieure adaptée du corps du serre-fil ;
• insérer un outil d'entraînement en rotation pour la vis de fixation du corps dans le trou central du bouchon ;
• visser la vis de fixation dans la structure métallique afin de fixer le serre-fil à la structure métallique à raccorder ;
• insérer un fil de mise à la terre dans les encoches ;
• serrer le bouchon fileté contre le fil à l'aide d'un outil d'entraînement en rotation adapté à engager le bouchon fileté.

In another aspect, the invention relates to a method of setting up a wire clamp having the steps of:

• present the wire clamp to a metal structure to be connected;
• putting a rotational locking tool on the suitable outer shape of the clamp body;
• insert a rotational drive tool for the body securing screw into the center hole of the plug;
• screw the fixing screw into the metal structure to fix the clamp to the metal structure to be connected;
• insert a ground wire into the notches;
• tighten the threaded plug against the wire using a rotating drive to fit the threaded plug.

• la figure 1 est une vue en perspective éclatée d'un serre-fil selon l'invention ;
• les figures 2 et 3 sont deux vues en perspective assemblées du même serre-fil ;
• la figure 4 est une vue en coupe du même serre-fil avec un outil de serrage inséré dans le trou central du bouchon ;
• la figure 5 est une vue en perspective éclatée du même serre-fil utilisant un type de vis différent.

The presentation of the invention will now be continued by the detailed description of an exemplary embodiment, given below by way of illustration and not limitation, with reference to the accompanying drawings. On these:

• the figure 1 is an exploded perspective view of a wire clamp according to the invention;
• the Figures 2 and 3 are two perspective views assembled from the same wire clamp;
• the figure 4 is a sectional view of the same wire clamp with a clamping tool inserted into the central hole of the plug;
• the figure 5 is an exploded perspective view of the same wire clamp using a different type of screw.

As visible in figure 1 , a wire clamp 1 for grounding a metal structure (not shown) comprises a body 10 having a threaded cylindrical cavity 11 opening at the upper end of the body and closed by a bottom 12 pierced with a hole 13 for the passage of a fastening screw 20 of the body 10 on the metal structure. The body 10 has, according to two generatrices of the cylindrical cavity 11, two slots 14 opposite each other and intended to receive a grounding wire (not shown).

A threaded cap is adapted to engage helically in the tapping of the cylindrical cavity 11. The plug has two diametrically opposed notches 31 forming rotational drive cavities for a flat screwdriver to tighten the cap against the electric wire placed against the bottom of the slots 14.

The screw 20 has a head 21 with a cruciform drive 22 and a threaded screw body 23.

The plug 30 further has a central hole 32 opening.

As seen more particularly in Figures 2 and 3 , the outside diameter of the screw head 21 is greater than the diameter of the central hole 32 of the Thus, once the screw inserted in the hole 13 and the cap 30 screwed into the body 10, the screw 20 is trapped in the clamp and therefore captive during its installation.

As seen more particularly in figure 4 however, the hole 32 is sufficient to allow a rotating drive tool 40 to come and screw the fastening screw of the body 10 onto the metal structure (not shown) through the plug. In the example illustrated here, it is a Phillips screwdriver 40 whose end corresponds to the footprint 22 of the screw.

In the example shown in Figures 1 to 4 it is a self-tapping screw. Thus, advantageously, it is sufficient to present the assembled wire clamp as visible in Figures 2 to 4 in front of a pre-drilled hole for this purpose on a metal structure to be connected to the earth, then to screw the self-tapping screw in the material of the metal structure by passing the screwing tool in the hole 32 of the plug 30. It is then a question of inserting laterally, radially, a wire of grounding in the slots 14 then to come to tighten the stopper by driving it in rotation with the aid of a flat screwdriver via the notches 31 provided in this effect in the plug 30. Thus, the core of the electric wire is tight against the bottom of the slots 14 thereby establishing an electrical contact between the body of the wire clamp 10 and the core of the wire.

As seen more particularly in figure 4 , in the example illustrated, the bottom 12 of the clamp body has a conical surface 15 making contact with the lower surface itself conical of the screw head 21. This structure contributes on one hand, to a good contact electrical connection between the screw 20 and the body of the wire clamp 10 and, secondly, a centering and guiding of the rotating screw during its tightening.

The screw being self-tapping, the electrical contact is established between the threading thereof and the thread that it is machined in the metal structure to be connected. Thus, in a very simple way, by performing two successive screwings without dismantling parts, a metal structure is grounded in a particularly simple and effective manner.

To prevent the body 10 of the wire clamp from rotating during the tightening of the screw 20 and neither during the tightening of the plug 30, or to orient the two through-slots of the clamp in the desired direction, it has a shape hexagonal outer member 16 adapted to cooperate with a flat key allowing the operator to maintain the body 10 immobile in rotation during the two successive tightenings mentioned above. Other embodiments are within the reach of the skilled person, such as two flats on either side of the body to cooperate with a flat key or a radial bore opening to cooperate with a torsion locking pin.

In an embodiment not shown, the body 10 of the wire clamp has a hexagonal outer shape from its base on a height substantially corresponding to the height of a flat key, then has a cylindrical outer shape.

In the exemplary embodiment illustrated, the body of the wire clamp, the plug and the fixing screw 20 are made of a material that is both conductive and resistant to corrosion, such as stainless steel.

The figure 5 is an exploded perspective view of a same wire clamp composed of a body 10 and a plug 30 in which a self-tapping screw 25 has been inserted.

The use of such a screw makes it possible to fix the wire clamp to a metal structure which has no hole prior to this fixing. For this purpose, it is preferable to use a portable screwdriver with a nozzle adapted to pass through the hole 32 of the plug 30 in order to drive the screw 25 in a manner similar to that shown in FIG. Figures 1 to 4 . The electrical contact between the screw 25 and the metal structure is the same as for the screw 20, namely via the thread of the screw 25 and the tapping of the resulting metal structure.

Note that the cruciform recess 22 shown in the example described above can be replaced by any other form of imprint within the reach of the art without departing from the scope of the invention. This may be for example a hexagon socket or an imprint for a flat screwdriver.

Many other variants are possible depending on the circumstances, and it is recalled in this regard that the invention is not limited to the examples described and shown.

Claims (10)

Wire clamp (1) for grounding a metal structure having a body (10) having a threaded cylindrical cavity (11) opening at a first end of the body, the other end being closed by a bottom (12) pierced with a hole (13) for the passage of a screw (20, 25) for fixing the body to the metal structure, the body having on at least part of the threaded cavity two slots (14) passing through the one of the other practiced along two generatrices of the cylindrical cavity and opening at said first end and
a threaded plug (30) having a rotary drive imprint (31) adapted to engage helically in the tapping of the cylindrical cavity for clamping a core of an electrical wire against the bottom of the slots (14) , characterized in that the plug has a central hole (32) opening adapted to let a rotating drive tool for the fastening screw of the body on the metal structure. A clamp according to claim 1, characterized in that it further comprises a fastening screw (20, 25) having a screw body (23) inserted into the hole (13) in the bottom of the clamp body and a screw head (21) having a rotational drive footprint (22) accessible through the central hole (32) of the plug for a corresponding rotational drive tool, and wherein the greatest width of the central hole is smaller than at the smallest outer width of the fastening screw head (21). Clamp according to the preceding claim, characterized in that the bottom (12) of the clamp body has a conical shape (15) widening toward the open end of the clamp body and the head (21). screw has a complementary conical shape. Clamp according to the preceding claim, characterized in that said screw (20) is a self-drilling screw (25) or a self-tapping screw (20). Thread clamp according to any one of claims 2 to 4, characterized in that the plug (30) has two notches (31) diametrically opposed forming rotational drive impressions for a flat screwdriver. Wire clamp according to one of Claims 2 to 5, characterized in that at least one of the following elements is made of stainless steel: wire clamp body (10), plug (30), fixing screw (20). , 25). Clamp according to the preceding claim, characterized in that the body (10) of the wire clamp has an outer shape adapted to cooperate with a locking tool in rotation of the body of the clamp. Clamp according to the preceding claim, characterized in that said outer shape is a hexagonal shape (16) on at least part of the height of the clamp body. Method for installing a wire clamp according to any one of Claims 2 to 5, characterized in that it comprises the steps of: - present the wire clamp (10) to a metal structure to be connected; inserting a rotational driving tool for the body fixing screw into the central hole (32) of the plug (30); - screw the fastening screw (20, 25) into the metal structure in order to fix the clamp to the metal structure to be connected; - insert a grounding wire into the slots (14); - tighten the threaded cap (30) against the thread with a rotating drive suitable for engaging the threaded plug. Method for placing a wire clamp according to claim 7 or 8, characterized in that it has the following steps: - present the wire clamp (10) to a metal structure to be connected; - Put a rotation locking tool in the outer form (16) adapted to the body (10) of the clamp; - insert a rotational driving tool on the screw for fixing the body in the central hole (32) of the plug (30); - screw the fastening screw (20, 25) into the metal structure in order to fix the clamp to the metal structure to be connected; - insert a grounding wire into the slots (14); - tighten the threaded cap (30) against the thread with a rotating drive suitable for engaging the threaded plug.

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