FR2704629A1 - Heating film of modular structure, for heating by radiation, and device for its connection - Google Patents

Abstract

This heating film is of the type formed by a support sheet which holds captive heating metal bands. According to the invention, it comprises on the one hand two lateral conducting bands (5), at least one of which forms regular loops (6), that is to say successively moves away from and draws close to the other band (5), delimiting, between the loops (6), portions (7) of film (2) where the bands (5) are close to one another and are parallel, and on the other hand heating bands (8) in a zig-zag shape which are connected by their ends to these two lateral bands (5), which occupy the greater part of the surface delimited by said loops (6).

Description

HEATING FILX WITH NODULAR STRUCTURE,
FOR RADIANT HEATING, AND
DEVICE FOR ITS CONNECTION
The present invention relates to a heating film with a modular structure, for radiant heating, in particular of radiant ceilings or cassettes, and a device for the connection of this film to the power supply and to other neighboring films.

 It is known to produce a heating ceiling by means of panels each comprising a heating film of dimensions corresponding to those of the panel, sandwiched between a facing plate and a block of thermal insulating material, the panels being placed side by side and supported by the supporting structure of a suspended ceiling.

 The connection of the films of the various panels to each other and to the general supply has the disadvantage of being very long, very tedious to produce and unreliable over time. In addition, the bypassing of unforeseen obstacles that may occur on either side of the heated ceiling (fallout from structural beams, lights, cupboards, etc.) is problematic given the defined dimensions of the various panels.

 It is known to use films of considerable length, which can extend over several adjacent panels. Some films have a single zigzag heating tape that spans their entire length.

 These films have the drawback of not being able to be cut to the desired length, depending on the various obstacles that may arise and the dimensions of the panels used. These films must, therefore, be made to the desired length, which is expensive, not very practical, and frequently causes a significant delay in the production of ceilings, when their length is not suitable.

 There is also known a heating film comprising a resistor constituted by a coating of carbon black taken between two lateral copper electrodes; on a variant of this film, the resistance is interrupted step by step for the achievement of the crossing of the framework of the ceiling or of the various abovementioned obstacles.

 This film can actually be cut to the desired length, depending on the obstacles included in the ceiling or the dimensions of the panels used.

However, by design, it has the disadvantage of involving a twisting of the electrodes and of the resistance when bypassing an obstacle, which results in a risk of heating and delamination of the resistance and the electrode. This delamination generates electric arcs and, consequently, the production of sparks, as well as the destruction of the insulating plastic envelope.

 Furthermore, the connection of existing films to each other and to the electrical source is carried out by means of copper conductive elements added by soldering to the film at the ends of the heating tape or side electrodes, which lead to a connection terminal. .

 The realization of the connection has the drawback of being complex and long, since it involves fixing these conductive elements to the film by welding them, on the one hand, to the ends of the heating tape or of the electrodes and, on the other hand , at the terminals of the connection terminal. These welds also have the disadvantage of oxidizing due to condensation, thereby affecting the flow of electric current and causing mechanical stresses related to differential elongations of materials (bimetallic strip effects).

 The existing connection devices themselves have the disadvantage of being complex, delicate to manufacture, fragile, and impractical to use.

 The present invention aims to remedy all of these drawbacks.

 To this end, the heating film which it concerns, of the type formed by a support sheet trapping heating metallic ribbons, comprises, on the one hand, two lateral conductive ribbons, at least one of which forms regular loops, i.e. -dire moves away and approaches successively the other ribbon by delimiting, between the loops, portions of film where the ribbons are close to each other and are parallel, and, on the other hand, ribbons zigzag heaters connected at their ends to these two lateral ribbons, which occupy most of the surface delimited by said loops.

 The film according to the invention thus has a modular structure, each module of which is delimited by the loop formed by at least one of the lateral ribbons. The film can be cut to the desired length at its portions where the ribbons are close to each other and according to the different obstacles presented by the ceiling to be fitted or the dimensions of the panels used.

These portions can, after cutting the film, directly receive the housing of the connection device by a simple and rapid installation, which will be described below, the approximation and the parallel nature of the ribbons between the loops facilitating the connection to the housing of the two ends of the ribbon, which are individualized by cutting the film to the desired length. At the end of the film opposite to that receiving the connection terminal, the ends of the tape are isolated or connected to another film by an appropriate extension.

 Advantageously, the film comprises slots or precuts arranged in its portions where the ribbons are close to each other, along the outer edges of the ribbons.

 Thus, the two ends of the ribbons can be individualized with respect to the film and in particular be folded upwards to facilitate the making of the connection, without adding foreign conductors which are a source of problems in current heating films.

 The connection device according to the invention comprises two claw clips made of conductive material, crimped onto the ends of the film tapes so that the claws pierce the insulating support film and come into contact with the metallic material constituting the tapes, the ends of these clamps being intended to be connected to a connection block also receiving the wires of the power cable, the block, after connection, being able to be engaged and retained by engagement in a housing constituting its support, itself fixed to the film by rapid means, in particular by adhesive material with which its base is filled.

 The connection of the ends of the tapes is thus particularly simple and quick to perform, without having to resort to soldering.

 Advantageously, the housing has a parallelepiped shape, is open on the top and the bottom, has a height substantially equal to that of the insulating material covering the film and includes a closure cover protruding beyond its side wall opposite to that comprising the hinge of articulation of this cover, the housing being intended to be fixed to the film after introduction of the connection block by its lower end, so that the projecting part of its cover is turned towards the insulating material.

 The housing, with this cover, makes it possible to constitute, in a very simple manner, a means of wedging the insulating material relative to the film and to the facing plate to which it is fixed.

 Advantageously, the means for locking the cover in the closed position are shaped so that they can only be released following a voluntary action by a person intervening on the heating ceiling. According to a preferred embodiment of these means, the cover comprises a well giving access to the upper part of a latching tooth locking the cover in the closed position, in order to be able to manually erase this tooth and release the opening of the cover.

 Preferably, the entire housing is molded in one piece, the articulation of the cover being constituted by a film hinge and the means for engaging the connection block being constituted by latching teeth arranged in its side walls. .

 In any case, the invention will be better understood with the aid of the description which follows, with reference to the appended diagrammatic drawing representing, by way of nonlimiting example, a preferred embodiment of the heating film with modular structure and of the casing connection of it it concerns.

Figure 1 is a perspective view of a portion of the heating film;
Figure 2 is a top view of a cut portion of the heating film, constituting a module thereof;
Figure 3 is a perspective view of the film, its electrical connection box and the insulating material intended to cover the film, with partial section of the latter two in two perpendicular, vertical and median planes; and
FIG. 4 is a sectional view of the connection box along the line IV-IV of FIG. 3.

 FIGS. 1 and 2 represent a heating film 2 with a modular structure, for radiant heating, in particular of ceilings. Such a heating ceiling is produced by means of panels each comprising a heating film 2 sandwiched between a facing plate supporting the heating film and a block 3 of thermal insulating material (FIG. 3), the panels being fixed side by side to a load-bearing framework suspended from the building ceiling.

 The heating film 2 is constituted by a support sheet 4 of electrically insulating material, trapping, on the one hand, two lateral strips 5 conductors forming regular loops 6, that is to say moving away and successively approaching the one of the other by delimiting, between the loops 6, portions of film 7 where the tapes 5 are close to one another and are parallel, and, on the other hand, heating tapes 8 in zigzag, connected by their ends 8a to the lateral ribbons 5 and occupying most of the surface delimited by said loops 6.

 The film 2 thus has a modular structure, each module of which is delimited by the loops 6 and by the portions 7 of film which separate them. The film 2 can thus be cut to the desired length at its portions 7 where the ribbons 5 are close to each other and according to the different obstacles presented by the ceiling to be fitted or the dimensions of the panels commonly used.

 Thus, each film module 2 represented in FIG. 2 has a substantially square shape with a side of 60 centimeters, which corresponds to the dimensions of the panels commonly used, which are generally 60 X 60 or 120 X 60. This shape and the dimensions may however change depending on the destination of this heating film.

 The film 2 further comprises slots 10 arranged in its portions 7 where the ribbons 5 are close to each other, along the outer edges of the ribbons 5.

 FIG. 3 represents the device 11 for connecting the film 2 to the cables 12 connected to the supply circuit and to the other heating films of the ceiling.

 It comprises a housing 13 housing a connection block 14 of the ends 5a of the strips 5 which have been individualized by cutting the film 2 to the desired length.

 The housing 13 is made in one piece, by molding a synthetic material.

 It has a parallelepiped shape, is open on the top and the bottom, has a height substantially equal to that of the insulating material 3 covering the film 2 and includes a closure cover 15 protruding beyond its side wall opposite to that comprising the hinge-film 16 for articulation of this cover 15.

 Its lower edge is extended by a rim 17 projecting outwards, coated with adhesive material by simple pressure, for its fixing on the film 2. Its side walls have two U-shaped notches opening into their upper edge for engagement of the cables 12, bordered by pairs of claws 18 capable of being erased when cables 12 are introduced into the notches and penetrating into the insulating sheath of these cables 12 when these cables are pulled towards the outside of the housing 13.

 In addition, its two closest walls have projections 20 for fixing by engagement of the connection block 14, and at least one latching tooth 21, visible in FIG. 4, for locking the cover 15 in the closed position. tooth 21 is supported, when the cover 15 is in the closed position, against the wall 15a of the cover 15 delimiting the bottom of a well 22 arranged therein.

 As shown in Figure 3, the connection device 11 also has two claw clips 25 of conductive material having a connection end 26. These claw clips 25 are crimped on the ends 5a of the strips 5 so that their claws pierce the insulating support of the film 2 and come into contact with the metallic material constituting the tapes 5.

 The connection block 14 has at two of its opposite ends eight connection orifices 30 which open opposite internal claws (not visible) capable of retaining the conducting wires after their engagement through the orifices 30.

 The four external orifices 30 of the block 14 are intended to receive and connect two by two the wires 31 of the cables 12 while two of the four orifices 30 located inwards are intended to receive the ends 26 connected to the claw pliers 25 and to connect them in derivation to wires 31.

 In addition, the housing 13 has a horizontal wall 32, interrupted in the central part to delimit a wedging housing of the block 14. At its ends facing the latter, it comprises a notch for the passage of the wires 26, bordered by an insulating partition. 33 for separating the wires 26 and 31.

Thus, any connection error is impossible and the partition 33 makes it possible to guide the ends 26 of the clamps 25 in the corresponding holes 30.

 In practice, as shown in FIG. 3, the slots 10 allow the ends 5a of the ribbons 5 to be folded upwards. After crimping the claw pliers 25, the ends 26 are engaged in the corresponding orifices 30 then the block 14 is engaged and placed in the housing 13 by engagement between the projections 20, this engagement being made possible by the relative flexibility of the walls of the housing 13. The cables 12 are then introduced into the lateral notches of the housing 13 and the conductive wires 31 engaged in the corresponding holes 30.

 The housing 13 is then fixed to the film 2 by pressing the adhesive material coated on the underside of its rim 17 against the film 2.

 The cover 16 is then brought into the closed position and locked in this position by means of the tooth 21. The part of this cover 15 projecting in the direction of the block of insulating material 3 makes it possible to constitute, very simply, a means of wedging the insulating material 3 with respect to the film 2 and to the facing plate (not shown) to which it is fixed.

 The well 22 and the latching tooth 21 constitute locking means which can only be released following a voluntary action by a person intervening on the heating ceiling, since the well 22 obliges this person to engage his finger in the well 22 in order, by erasing the tooth 21, to unlock the cover 15. Thus, any possibility of unwanted opening of the housing is eliminated.

 Thanks to the device 11, the connection of the ends 5a of the strips 5 is particularly simple and quick to produce, without having to resort to welding or tightening of screws.

Claims (8)

 1 - Heating film with modular structure, for radiant heating, of the type formed by a support sheet enclosing metallic heating tapes, characterized in that it comprises, on the one hand, two lateral conductive tapes (5) of which at least one form regular loops (6), that is to say moves away from and successively approaches the other strip (5) by delimiting, between the loops (6), portions (7) of film (2) where the ribbons (5) are close to each other and are parallel, and, on the other hand, zigzag heating tapes (8) connected by their ends to these two lateral ribbons (5), which occupy the major part of the surface delimited by said loops (6).  2 - Heating film according to claim 1, characterized in that it comprises slots (10) or precuts arranged in its portions (7) where the ribbons (5) are close to each other, along the edges exterior of these ribbons (5).  3 - Heating film according to claim 1 or claim 2, characterized in that each of the modules that it comprises has substantially a square shape of 60 centimeters on a side.  4 - Device for connecting a heating film, characterized in that it comprises two claw clips (25) of conductive material to be crimped on the ends (5a) of the ribbons (5) of the film (2) so that the claws pierce the insulating support film and come into contact with the metallic material constituting the strips (5), the ends (26) of these clips (25) being intended to be connected to a connection block (14) receiving moreover the wires (12) of the power cable, the block (14), after connection, being able to be engaged and retained by engagement in a housing (13) constituting its support, itself fixed to the film (2) by rapid means, in particular by pressure-sensitive adhesive material with which its base (17) is filled.  5 - Device according to claim 4, characterized in that the housing (13) has a parallelepiped shape, is open on the top and the bottom, has a height substantially equal to that of the insulating material (3) covering the film (2 ) and comprises a closure cover (15) projecting beyond its side wall opposite to that comprising the hinge (16) of articulation of this cover, the housing (13) being intended to be fixed to the film (2) after insertion of the connection block (14) through its lower end, so that the projecting part of its cover (15) is turned towards the insulating material (3).  6 - Device according to one of claims 4 or 5, characterized in that the locking means (15a, 21) of the cover (15) of the housing (13) in the closed position are shaped so that they can only be released following a voluntary action by a person working on the heated ceiling.  7 - Device according to claim 6, characterized in that the cover (15) comprises a well (22) giving access to the upper part of a latching tooth (21) locking the cover (15) in the closed position.  8 - Connection device according to one of claims 4 to 7, characterized in that the housing (13) is molded in one piece, the articulation of the cover (15) being constituted by a film hinge (16) and the engagement means of the connection block (14) being constituted by latching teeth (20) arranged in its side walls.