EP1590989A1

EP1590989A1 - Soft heating device

Info

Publication number: EP1590989A1
Application number: EP04701296A
Authority: EP
Inventors: Reinhold Wanner; Hans-Georg Gingl; Ernst Merk; Ralf KÖHLER; Ingolf Rathbeg; Werner Bader
Original assignee: Beurer GmbH and Co
Current assignee: Beurer GmbH
Priority date: 2003-01-23
Filing date: 2004-01-10
Publication date: 2005-11-02

Abstract

The invention relates to a soft heating device (1) such as a heat blanket, heat cushion or heat feather-bed, comprising at least one heating cord (3,3') arranged on a base heating element (2); a connection cable (5) for an energy supply, connected thereto by means of an externally insulated connecting means (10); and a control circuit (6). The heating device has a robust structure by virtue of the fact that the connecting means are grouped together (10) in a connecting unit (4) comprising a common carrier plate (4.1) and/or a common encapsulating element (4.3).

Description

Supple arming device

The invention relates to a flexible heating device, such as a warming blanket, heating cushion or heating underblanket, with at least one heating cord arranged on a heating element, a connecting cable connected to it via externally insulated connecting means for power supply and a control circuit.

Such a heating device is specified, for example, in DE 101 26 066 A1, a connection between a heating cord and a connecting cable in the edge region of a basic heating element, for example a ceiling, being shown. In addition to the heating cord with the heating wires contained therein, further components of the electrical circuit can be arranged in particular in the edge region of the ceiling, such as a fuse and a display element, for example with circuitry. In one embodiment, the A rectifier arrangement can also be provided from the ends of the two heating wires of the heating cord remote from the connecting cable. A control circuit has at least one on / off switch, but in one embodiment has a multi-stage switch and can also include other components.

Another heating device of this type is shown in EP 0 562 850 A2, in which the heating cord, which also has, for example, two coaxial heating conductors, is connected via two connection points to a connecting cable, in the course of which a control circuit is arranged. The control circuit here has a special security system which has a rectifier device in the form of a diode which is arranged between the heating wires on the end remote from the connection-side end of the heating cord and in the control circuit has a thermally triggerable fuse. In normal operation, the diodes arranged in series between the heating wires only allow a half-wave of the supply current to pass through, but if the heating wires are short-circuited, the negative half-wave of the heating current is also let through, which is then fed via a further rectifier device in the control circuit to a resistor arrangement which is connected to a fuse responding to temperature increase is thermally coupled and triggers when the heating wires are short-circuited. The control circuit further comprises a control element in the form of a thyristor for temperature control.

With such heating devices, safe installation and function are of particular importance.

The invention has for its object to develop a flexible heating device of the type mentioned in such a way that safe assembly and function are achieved or at least favored. This object is achieved with the features of claim 1. According to this, it is provided that the connecting means are combined in a connecting unit which has a common carrier plate and / or a common encapsulation.

With these measures, simple, clear training of critical connection points contributes to increased reliability.

An embodiment which is advantageous for use is that the connection unit is arranged on the heating element and is fixed with holding means.

A reliable, unambiguous assembly benefits from the features that the carrier plate is designed as a circuit board with printed conductor tracks, which carries several connecting elements of the connecting means, some with an associated heating conductor and some with an associated wire of the connecting cable and - if provided - for Manufacture relevant current paths are interconnected by means of conductor tracks.

If it is provided that the heating cord has two heating conductors which are connected to one another at one end of the cord with associated wires of the connecting cable and at the other end of the cord either directly or via a rectifier arrangement incorporated in the connecting unit, then both ends of the cord can be easily connected and connected.

A construction which is advantageous for the assembly and the mode of operation is achieved in that a current fuse arranged in the supply circuit is accommodated in the connection unit. The measures that the encapsulation is formed by casting or by means of two joined shell elements also contribute to safety. The insulating material is matched to the special safety requirements for a cast or injection-molded encapsulation on the one hand and a shell version on the other, the insulation properties and measures for plug-in, or clamp or crimp connections being adapted to the higher requirements than, for example, solder connections due to the higher contact resistance are.

Critical points of the heating cord and the connecting cable are reliably protected with a simple construction in that the encapsulation has at least one cord guide molded onto it for the heating cord and one molded cable guide for the connecting cable.

Further advantageous measures that contribute to safety are that the encapsulation consists of elastic plastic material at least in the area of the cord guide (s) and / or the cable guide and is melt-resistant up to 150 ° C. as well as flame-retardant and tension-proof.

For simple assembly and reliable contacting, the measures contribute that the connecting means for inserting and clamping are designed with electrical contacting of one or both heating cord ends and that a cover part on its side facing the connecting means has formations which interact with the connecting means in such a way that the clamping during The shell elements are joined together. A stable, tension-resistant arrangement is supported in that the connection unit is fixed on the heating element by fixing the assigned connection cable end and / or at least one cord end.

The invention is explained in more detail below using exemplary embodiments with reference to the drawings. Show it:

1 is a flexible heating device with a connecting unit between the heating cord and the connecting cable in a schematic representation,

2 shows a schematic representation of a carrier plate of a connecting unit,

3 shows an exemplary embodiment of a connecting section of a heating cord,

4A and 4B two different embodiments of encapsulated connection units in a schematic representation,

5 shows a perspective, open view of a further exemplary embodiment for a connecting unit,

Fig. 6 different connecting means and Fig. 7a), b) and c) different closing states of connecting means in cross section.

1 schematically shows a flexible heating device 1 with a meandering heating element 3, for example a blanket, a pillow or a lower bed, a heating cord 3, a connecting cable 5 that can be connected to a supply voltage by means of a plug 7, in the course of which a control circuit 6 is arranged, as well as a connecting unit 4 arranged between the heating cord 3 and the connecting cable 5 in an edge region of the base element 2. As FIG. 4B shows, different heat zones can be formed on the base element 2 by means of at least one further heating cord 3 ', which is suitably on the Basic element 2 is laid.

As is customary per se, the heating cord 3, 3 'advantageously has two heating conductors made of resistance wire, which are arranged in the heating cord 3, 3' insulated from one another, as can be seen, for example, from FIG. 2. An advantageous embodiment known per se is that the one heating wire as the outer conductor 3.2 and the other heating conductor as the inner conductor 3.4 coaxially separated from one another and electrically isolated from one another by means of intermediate insulation 3.3 and insulated from the outside by means of outer insulation 3.1 and wound in a coil shape in the heating cord 3 , 3 'run. When current flows through the two heating conductors 3.2, 3.4 in the opposite direction, a compensation of their electromagnetic fields is achieved. The inner conductor 3.4 is wound on an insulating core. It can also exist as a so-called lantern with multiple threads and is then particularly flexible and uninterruptible. As further shown in FIG. 2, the cord end 3.5 and the cord end 3.6 facing away from it are both electrically connected and mechanically fixed on a carrier plate 4.1 of the connecting unit 4, connections in particular also being made to the inner conductor 3.4j and the outer conductor 3.2. A direct contact can be made between the outer conductor 3.2 and the inner conductor 3.4, in particular at the cord end 3.6 facing away from the connecting cable 5 or, as shown in FIG. 2, a rectifier device in the form of one or more semiconductor diodes 8 can be arranged. Other or further electrical components, such as those shown in the two documents mentioned at the beginning, can also be connected between the outer conductor 3.2 and the inner conductor 3.4 on the carrier plate 4.1.

The cord end 3.5 on the connecting cable side is connected with the outer conductor 3.2 and the inner conductor 3.4 to assigned wires 5.1, 5.2 of the connecting cable. A fuse element 9, for example a current fuse, can be arranged on the carrier plate 4.1 between a wire, for example 5.1, and a heating conductor, for example the outer conductor 3.2. The connection between the wires 5.1, 5.2 of the connecting cable 5 and the outer conductor 3.2 and inner conductor 3.4 is established via conductor tracks 4.12 of the carrier plate 4.1 arranged on the side facing away from the component side. Wire pins, retaining lugs, retaining tabs or crimp connectors or the like can be arranged and connected as connecting means 10 (cf. also FIGS. 5, 6 and 7) for establishing an electrical connection between the outer conductor 3.2 and the inner conductor 3.4 on one side of the carrier plate 4.1 the opposite side of the carrier plate 4.1 be connected to the conductor tracks 4.12. Correspondingly, the components 8, 9 and also the contacting of the wires 5.1, 5.2 of the connecting cable 5 with the outer conductor 3.2 or inner conductor 3.4 can be made, as known per se from the PCB assembly. Clamping, crimping, soldering or welding connections can be used for contacting. The connecting cable 5 is secured to the base element 2 with tensile strength by means of fixations 2.1, for example sewn or welded, in order to avoid tearing off the connecting cable 5 or the connecting unit 4. In addition, the heating cords 3, 3 'can also be fastened on the base element 2 and the connecting unit 4 can also be additionally fixed on the base element 2. Another design option is that the mechanical connection between the base element 2 and the connection unit 4 is made with a clip.

The clip has several functions, namely that it can relieve the strain on the connecting cable 5, fix the connection unit 4 and thus also relieve the strain on the heating cord (s) 3, 3 ', kink protection of the connecting cable 5 with various embodiments, for example a trumpet-shaped outlet opening. Cable grommet or the like., A cover of the cable outlet from the base element 2 or as a carrier for user information, logos, technical data, type plate or the like. The clip can be made of different materials, for example plastic, metal or a combination thereof. In its design of the clip, latching hooks are provided which simultaneously serve as push-through tools through at least one cover layer of the base element 2 and can also cause the connecting unit 4 to latch. To save tool costs, the clip is designed, for example, so that self-locking can take place by means of two identical parts, which are arranged rotated by 180 ° to one another. Alternatively, the clip can consist of one or more parts, which include, for example, a kind of film hinge that allows kinking. The rectifier elements 8 and possibly further electrical components can cooperate with further electrical circuit components of the control circuit 6 to form a temperature control circuit and / or a safety system, for example as set out in the documents mentioned at the beginning.

Fig. 3 shows a special embodiment of a connecting section of the heating cord 3, 3 '. In this case, a coupling element 3.7 is placed on the heating cord end 3.5, 3.6, for example by a type of screw connection or clamping, which has windows cut free on one side, one of which has the outer conductor 3.2 while the outer insulation 3.1 is omitted and the other with the outer conductor 3.1 being omitted, the outer conductor. 3.2 and the intermediate insulation 3.3 releases the inner conductor 3.4. With the coupling element 3.7, an electrical contact in the manner of a coaxial connector can be produced on a complementarily designed counterpart (not shown). The coupling element 3.7 can be accommodated in a connecting unit 4, specifically in an encapsulation 4.3 thereof, as is shown in FIGS. 4A, 4B and 5. With such a connection, an embodiment is possible in which the coupling element 3.7 or plug element of the heating cord 3 is inserted once into the counterpart or connecting element and (not detachably) latched, or in which the connecting cable 5 is equipped with one or more corresponding counter elements can be removed in order to wash the heating device, for example in a machine. In one embodiment variant, one side of the plug element could already short-circuit the heating cords! 3 form between the inner conductor 3.4 and the outer conductor 3.2. The connecting element then acts as a strain relief for the heating cord 3, 3 '. The encapsulation 4.2 shown in FIGS. 4A and 4B is produced by means of casting technology, the carrier plate 4.1 with the mounting parts arranged thereon, ie components, connecting cable ends and cord ends 3.5, 3.6, being completely encapsulated by means of a heat-resistant, voltage-resistant and fire-resistant, flame-retardant insulating compound , which is advantageously also washable and waterproof. The melt resistance is at least 150 ° C, advantageously above 160 ° C or 170 ° C, so that it can withstand the temperatures that occur. Resistance to melting over 100 ° C is guaranteed. If, despite the reliable contacting measures, contact resistance occurs and leads to heating, a hazard is avoided by means of the encapsulation 4.2. On the encapsulation 4.2, which preferably consists of elastic insulating compound, sealing cord guides 4.21 or a cable guide 4.22 for the cord ends 3.5, 3.6 and the connecting cable 5 are integrally formed, which provide secure kink protection for the heating cord 3, 3 'or the connecting cable 5 result.

FIG. 4B shows a connection unit 4 for a heating device 1 with two heating cords 3, 3 ', it being possible for the connections, as shown in FIG. 2, to be designed in duplicate. Different connection types can also be selected for the two heating cords 3, 3 ', as described in connection with FIG. 2. For example, it is conceivable to operate a heating cord via a temperature control circuit with a safety system, such as in the prior art mentioned above or related developments known per se, and to operate the other heating cord via a simpler control circuit. In any case, the connection unit 4 permits a secure, unambiguous connection of the heating cords 3, 3 'to the connecting cable 5, if necessary via the components used. Fig. 5 shows a further embodiment of a connecting unit 4. Here, the encapsulation 4.3 is composed of two shell parts which can be connected tightly to one another, namely a lower part 4.31 and a cover part 4.38 (see FIG. 7), the holding elements 4.33, for example in the form of Have blind holes and cooperating holding counter-elements in the form of projections adapted to them. Clamping or snap-in connections or sealing adhesive or welded connections are also suitable. The structure can advantageously also be formed from a two-component plastic with a harder core section and a softer, sealing coating. A middle section of the encapsulation 4.3 accommodates the carrier plate 4.1, while a cord guide 4.34 molded onto the middle part with strain reliefs 4.35 serves for feeding the heating cords 3, 3 'and a cable guide 4.32 molded onto the middle part results in a secure feeding of the connecting cable 5. To uniquely position the carrier plate 4.1, it has laterally positioning elements 4.1 1 in the form of recesses, into which adapted positioning counter-elements 4.36 arranged in the middle part of the encapsulation 4.3 engage. In order to obtain strain relief and sealing, the cable guide 4.32 for the connecting cable 5 has a clamping part 4.37. Clamping contacting connecting means 10 are also provided on the carrier plate 4.1 for the cord ends 3.5, 3.6 or their outer conductors 3.2 and inner conductors 3.4. A securing element 9 and / or a rectifier device 8 can also be arranged on the carrier plate 4.1 according to the previous exemplary embodiments.

6 and 7 show different examples of configurations of the connecting means 10 and their contacting. According to FIG. 6, punched and bent sheet metal parts are the first connecting element 10.1 on the inner conductor 3.4 of the Heating cord 3, 3 ', as a second connection element 10.2 on the outer conductor 3.2 and as a further connection element 10.3 contacted with a component, for example the fuse element 9 or the semiconductor device in the form of a diode 8, the second connection element 10.2 and the further connection element 10.3 on the same Sheet metal part are arranged. In order to establish a direct connection or a short circuit between the inner conductor 3.4 and outer conductor 3.2 at a cord end 3.6, the first connecting element 10.1 and the second connecting element 10.2 can be integrally connected to one another via a conductive bridge 10.4. 6, the outer conductor 3.2 and the inner conductor 3.4 are inserted into an initially open clamp connection, which is then bent while the connections of the component 8 or 9 are clamped in a kind of cutting connection on the further connecting element 10.3.

As can be seen from the sequence of figures 7a) and b), the clamp connection can be produced in that, for example, the cover part 4.38 of the encapsulation 4.3 has recesses which interact with the free ends of the connecting elements 10.1, 10.2 and which narrow and with their flanks when the cover part is pressed on 4.38 compress the free ends of the connecting elements 10.1, 10.2. 7a) shows the still open and FIG. 7b) shows the pressed-on state of the cover part 4.38, while FIG. 7c) shows the pressed-on state without the connecting means 10 being inserted. The connecting means 10 can be placed on a carrier plate 4.1 or without such directly in the encapsulation 4.3. Soldered or welded connections generally place less demands on the constructive solutions of the contact connections. In the simplest case, all components of the connection unit can be soldered or welded onto a circuit board or metallically conductive parts. For example, this eliminates the crimping of the heating cord contact; Solder pins can be provided in different configurations for wrapping and soldering only for fastening the resistance wires. For example, the winding pins (soldering nails) could be rectangular or pre-assembled in another form in a circuit board or in plastic. The advantage of rectangular soldering pins compared to round pins is that the resistance wire digs in at the sharp edges and can therefore slip less until the connection is soldered.

The connecting unit 4 can also be designed to accommodate further or other components, for example it can include further circuit parts of a safety device (for example described in more detail in DE 102 1 1 142 A1) (further diodes, temperature fuse, these resistance elements which are triggered by heat), temperature control elements, Timers, temperature monitoring elements or a switching unit or combination of such parts included.

Claims

Expectations

1 . Supple heating device (1), such as a warming blanket, heating cushion or underblanket, with at least one heating cord (3, 3 ') arranged on a basic heating element (2), a connecting cable (5) connected to it via externally insulated connecting means (10) for energy supply and one Control circuit (6), characterized in that the connecting means (10) are combined in a connecting unit (4) which has a common carrier plate (4.1) and / or a common encapsulation (4.3).

2. Device according to claim 1, characterized in that the connecting unit (4) on the heating element (2) is arranged and fixed with holding means (2.1).

3. Device according to claim 1 or 2, characterized in that the carrier plate (4.1) is designed as a circuit board with printed conductor tracks, the plurality of connecting elements (10.1, 10.2, 10.3) Connection means (10) carries, which are partly connected to an associated heating conductor (3.2, 3.4) and partly to an associated wire (5.1, 5.2) of the connecting cable (5) and - where provided - for the production of current paths in question by means of conductor tracks (4.12) ,

4. Device according to one of the preceding claims, characterized in that the heating cord (3, 3 ') has two heating conductors (3.2, 3.4) which on one cord end (3.5) with assigned wires (5.1, 5.2) of the connecting cable (5) and at the other cord end (3.6) are electrically connected to one another directly or via a rectifier arrangement (8) accommodated in the connecting unit (4).

5. Device according to one of the preceding claims, characterized in that a current fuse (9) arranged in the supply circuit is accommodated in the connection unit (4).

6. Device according to one of the preceding claims, characterized in that the encapsulation (4.3) is formed by casting or by means of two joined shell elements (4.31, 4.38).

7. The device according to claim 6, characterized in that the encapsulation (4.3) has at least one cord guide (4.21) molded thereon for the heating cord (3, 3 ') and a cable guide (4.22) molded thereon for the connecting cable (5).

8. Device according to one of the preceding claims, characterized in that the encapsulation (4.3) at least in the region of the cord guide (s) (4.21) and / or the cable guide (4.22) consists of elastic plastic material and at least up to 150 ° C melt-resistant and heavy is flammable and tension-proof.

9. Device according to one of claims 6 to 8, characterized in that the connecting means (10) for inserting and clamping with electrical contacting one or both heating cord ends (3.5, 3.6) are formed and that a cover part (4.38) on the connecting means ( 10) facing side with the connecting means (10) has such interacting shapes that the clamping takes place when the shell elements (4.31, 4.38) are joined together.

10. Device according to one of the preceding claims, characterized in that the connecting unit (4) is fixed by fixing the associated connecting cable end and / or at least one cord end (3.5, 3.6) to the basic heating element (2).