Interface device for electrical connections in washing and drying machines the device having rigid plane elements and flexible printed circuits

Abstract: Electrical interface device for washing and drying machines and the like, composed of at least one rigid plane element, to which there are firmly applied one or more flexible printed circuits, electric­ ally connected to one another and to the electromechanical and/or electronic programming component of the machine; the edges of said rigid plane element and of said flexible printed circuits being shaped with alternating slots and teeth, to the last-named of which there are brought the terminals of the electrical paths of the cir­ cuits, forming in this manner zones adapted for the insertion of electrical connectors of low and high power.

Description: The subject of the present invention is an electrical interface device especially for the electrical equipment of washing machines and the like. As is known, the control of the cycle sequences of said machines is realised by an electromechanical and/or electronic programmer, to which there are led all the electrical power and control cables of the various electrically operated components, such as: motors, pumps, heating resistors and the like. All the aforementioned cables are, at present, connected to the programmer by means of connectors of various types, but singly and without a precise logical order of connection, in that the arrangement of the electrical outputs of the programmer is associated with its internal structure and not with the final operating diagram or layout; furthermore, no distinction is made between power outputs and non-power outputs, which necessitates over-dimensioning of those outputs which, being intended for carrying a current less than five amps, could be constructed in a different manner at a much lesser cost. In an attempt to overcome these disadvantages, certain types of centralized units applied in the automobile industry are known, but these are not ideal in so far as the internal cabling of the various contact points, the sizes, the weight and the production costs, are concerned. FR-A-2 557 378 discloses an interface device where circuit boards having contact teeth are sandwiched on a programming unit, thereby forming contacts and interconnections. The objective of the present invention is the overcoming of the aforementioned disadvantages by means of an interface structure particularly for washing machines and the like, which shall be extremely compact, shall reduce to the minimum the number of internal cables necessary, and shall allow the connectors to be arranged in an orderly manner in the sense of affinity of use, at the same time achieving the best orientation possible of the outputs in the direction of the final user device, as well as, when required, the realization of the power outputs in a different manner from that of the non-power outputs. These objectives are achieved by the electrical interface device according to the present invention, which is characterized by the features of claim 1. It realizes the interconnection, arrangement and orientation of the electrical outputs of electromechanical and/or electronic programming components, and the fundamental characteristics of it reside in being composed of at least one base rigid plane element, to which there are firmly applied one or more flexible printed circuits, electrically connected among themselves and to the electromechanical programming component; the edges of said rigid plane and of said flexible printed circuits being profiled with alternating slots and teeth, to the last-named of which there are brought the terminals of the electrical paths of the circuits, in this manner realizing zones adapted for the insertion of electrical connectors of low and high power. It is also provided in embodiments of the device that said rigid plane shall be a printed circuit of the rigid type and that the flexible printed circuits shall be of a larger size than the rigid plane element. The device according to this invention furthermore provides that said rigid plane elements are greater than one in number, and may be disposed below and are disposed above said flexible printed circuits in accordance with a suitable combination of rigid plane elements, rigid printed circuits and supports for power outputs, in such a manner that the rigid elements shall be outside the pack of printed circuits after they have been folded and made electrically and mechanically integral with the programmer and with the flexible printed circuits, which are folded over onto themselves so as to bring the upper rigid elements onto one plane parallel with that of the lower element. The mechanical rigidity of the device constructed in this manner is assured by two plane elements, equipped with openings adapted for receiving corresponding projections for fixing, formed on the edges of said rigid elements. It is also provided that said alternation of slots and teeth shall be geometrically such as to produce zones for insertion of asymmetrical connectors, achieving a polarization which prevents incorrect insertions on said terminals of the electrical paths, which are arranged and grouped on said teeth on the basis of their final functional or practical affinity; such arrangement and grouping may also be achieved on the basis of closer proximity of the insertion zone for the electrical connectors to the destination component for the signals. These and other characteristics will become apparent from the following description, given by way of a non-limiting example, of the interface device, prepared in relation to the drawings, in which there are shown: in Fig.1: a perspective view of the components, the device not being yet connected; in Fig. 2: a perspective view of an assembled device not in accordance with claim 1; in Fig. 3: an enlarged section of the device on the line II-II in Fig. 2; in Fig. 4: an example of a possible variant of construction of the device in accordance with claim 1. With reference to fig. 1, the device is constituted of a plane rigid element 1, the perimeter of which is shaped to possess projections 2, located between slots 3, forming the insertion zone for the connector 4 (fig. 2); on the upper face of said rigid element 1, there are firmly attached by a known technique one or more printed circuits of the flexible type 5, the edge of which is shaped in such a manner that the zones in which the electrical connection strips 6 are formed coincide, although on different planes, with the corresponding zones 2 of the rigid element 1. In this manner, as illustrated in the enlarged section of fig. 3, it is possible to keep the density of paths for each flexible circuit sufficiently low and to optimize the arrangement of the paths and of the electrical interconnections, reducing crossings to a minimum, and forming at the same time a connection zone, generally referenced 7, in which the different contact strips 6a and 6b can be selected from among those that are alike, for example for function or for destination of use (such as all the controls of the pump). Said alternation of projections 2 and slots 3 is, moreover, adapted for making the connection zones 7 asymmetrical among themselves, thereby achieving a polarization, as a result of which it is possible to avoid the frequent errors of insertion of the single connectors. By choosing, at the design stage, the various distributions of connections desired, it will also be possible to choose the sides of the printed circuits upon which specific connections are to be formed, for example on the basis of closest proximity of this side to the final destination of that particular item of cabling. With reference to fig. 2, there is also shown the construction of outputs 21, in this example of the lamellar type known as "fast-on", adapted for receiving power connectors for loads greater than 12 amperes. The interface device constructed in this manner is then applied to the programmer according to the desired arrangement of the holes and of the needles 8a of said programmer and, after this, by flow soldering, made possible by the fact that all the components, including the power outputs 21 appropriately pointing downards, again lie on a single plane, electrically and mechanically connected to it. If the greater complexity of the circuits or the need to contain the final costs of the product demand it, it would be possible to construct the interface device by realizing the rigid plane 1 of a printed circuit of the rigid type, which assures simultaneously the mechanical rigidity and the presence of further electrical paths. One possible variant is illustrated in fig. 4, in which it is shown that there are applied, to said rigid plane element 1, the flexible printed circuits which may have a larger dimension than that of the rigid plane 1; in this manner, two rigid elements, selected according to the requirements, mays be welded onto the free end projecting flexible circuit portions 9a, 9b, 9c; in the example of this figure, a rigid printed circuit 10 and a support for power outputs 11. It is also possible to keep a portion 20 of flexible printed circuit free, with its end carrying suitable conductor zones 20a, and of a length such that it can be directly connected to a final user component instead of a cable. Once the already described flow soldering has been carried out, it will be possible to bend the flexible circuits upwards, causing the ends of the two elements 10 and 11 to fit together and rendering the structure thus obtained mechanically rigid by means of the engagement of the two plane elements 13a and 13b, the apertures 13c of which should be fitted onto the corresponding fixing projections 14, formed respectively on the edges of the rigid elements 1, 10 and 11. The rigid elements 1, 10 and 11 can be preselected in accordance with a suitable combination of rigid plane, rigid printed circuit and support for power outputs. The supporting structure thus formed is adapted for withstanding, under operating conditions, the loads and/or pressures resulting from the insertion and removal of the female connectors without the possibility of accidental contacts taking place between the facing contact points. The application of the interface device to the electromechanical and/ or electronic components as described also enables the or some of the male connectors to be grouped in such a manner as to permit the separate construction of the associated cabling with female terminal connectors already fitted, in such a way as to reduce production costs and to eliminate the possibility of mistakes in connecting up the component with the various items of equipment controlled or operated by it. It will be understood that, for each electromechanical and/or electronic component, to which the interface device according to this invention is to be applied, it is necessary to adapt the dimensions and shape of the profiled members and of the printed circuits to the particular requirements and arrangements of each component, without thereby departing from the scope of the present invention.

Claims: Electrical interface device for electromechanical programming components (8) comprising at least one base rigid plane element (1) having edges profiled with alternating slots (3) and teeth (2), to which plane element (1) there are firmly applied one or more flexible printed circuits (5), electrically connected to one another and being connectable to the programming electromechanical component (8), the terminals (6a, 6b) of the electrical paths of the flexible circuits (5) being brought to said teeth (2), characterized by the fact that it comprises at least a further rigid element (10, 11) electrically and mechanically integral with one end (9a) of the flexible printed circuit (5) and able to be arranged in a plane parallel and above the base rigid element (1) through folding of the flexible circuits (5), two plane elements (13a, 13b) being provided for the mechanical rigidity of the interface device; and by the fact that outputs (21), suitable for the insertion of power connectors, are fitted to the base rigid plane element (1), in this manner realizing an interface device having zones adapted for the insertion of electrical connectors, whether of low power or of high power. Device according to claim 1, characterized by the fact that said base rigid plane element (1) is a printed circuit of the rigid type which possesses, at its free end, zones that are made conducting and adapted for being directly connected to a user device. Device according to claim 1, characterized by the fact that said two plane elements (13a, 13b) are equipped with windows (13c) adapted for receiving corresponding fixing projections (14) formed on the edges of said rigid elements (1, 10, 11), to which they are joined according to a direction orthogonal to the base element (1). Device according to claim 1, characterized by the fact that said outputs (21) for the insertion of power connectors are orientated to the side of connection with the programming components (8) for permitting flow soldering of the device to the programming component.

Inventors: THEPAULT CLAUDE, THEPAULT, CLAUDE
Applicants: CROUZET SPA, CROUZET S.P.A.
Application year: 1988
Main classification: H01R9
IPC codes: H01R12, H05K3, H05K1