Abstract:
A multiple switch includes a pair of switch units arranged in a row and forming a common actuating surface. The switch units are provided with uniform module housings ( 12 ). The adjoining module housings ( 12 ) are mechanically rigidly coupled to each other by a connecting element ( 14 ).

Description:
The present invention relates to an electrical multiple switch, comprising two or more switch units arranged in a row and defining a common actuating surface. 
     BACKGROUND OF THE INVENTION 
     Multiple switches are used in motor vehicles for the electrical control of various devices when related control functions are rendered visualized by packaged switch arrays in accordance with ergonomic and also design criteria, e.g. on the dashboard. By making use of discrete switch modules for inserting in suitable openings of a facial panel, optional arrays of switches can be combined; however, fitting and wiring the discrete switch modules is highly complicated. This is why such multiple switches are fabricated in uniform modules which ensure not only a perfect alignment of the switch units for a neat appearance but also rationally and functionally correct wiring of the discrete switch units. 
     The production of such multiple switches having housings made mostly of plastics necessitates complex, additional molds and production lines which due to the resulting extra expense involved bloat the production costs. 
     BRIEF SUMMARY OF THE INVENTION 
     The invention provides a multiple switch which, whilst having no disadvantages as regards its visualization and rationally and functionally correct wiring, is considerably more cost-effective in production. 
     In accordance with the invention the switch units are provided with uniform separate module housings, and two adjoining module housings are mechanically rigidly coupled to each other by a connecting element, thus enabling the module housings for optionally complex multiple switches to be produced with the same relatively simple mold. The connecting element is a component simple in shape whose production likewise involves little expense. The adjoining switch units may be configured in a uniform geometry and provided with symbols to distinguish them from each other. 
     It is particularly expedient to produce the module housings as well as the connecting element by injection molding from plastics. 
     The module housings of the multiple switch are coupled preferably both with an interlocking fit and by welding to the connecting element and thus also to each other. Perfect alignment of the module housings relative to the common switch facial panel is achievable by making use of a template and subsequent welding to make the final location. 
     The positive connection elements on the two terminal sides for mechanically coupling and prelocating the module housings having the necessary number of connecting parts are preferably polarized, i.e. differing by at least one property such as shape, size and arrangement so as to ensure an unmistakable orientation of the module housings within a switch array. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Further features and advantages of the invention read from the following description of an advantageous embodiment and with reference to the attached drawings in which: 
     FIG. 1 is a view in perspective of a multiple switch including two switch units; 
     FIG. 2 is a detail section through the multiple switch; and 
     FIG. 3 is a view in perspective of a connecting element on a magnified scale. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIG. 1 there is illustrated the multiple switch identified in general by the reference numeral  10 , it comprising two switch units each including a module housing  11 ,  12  and a connecting element  14  connecting the adjoining module housings. The uniform module housings  11 ,  12  are in general cylindrical, have a cross-sectional shape corresponding to the desired appearance and are designed for insertion in a common switch facial panel on a dashboard mount in the vehicle. They are produced by being injection molding from plastics using a uniform mold, the same as for the connecting element  14 . For their alignment in a common switch facial panel the module housings  11 ,  12  have a peripheral support collar  16 ,  17  and are provided with latching elements  18 ,  19  which when inserted into an opening in the switch facial panel clasp the rim of this opening. Each switch unit is provided with a key  20 ,  21  slidingly guided in the corresponding module housing  11 ,  12 , whereby the key may be provided with an illuminatable symbol. 
     The connecting element  14  consists of a generally cuboidal (generally parallelepipedal) base body  22  comprising two parallel main surface areas capable of being joined to the side surface areas of the module housing  11 ,  12 , a base surface area, an upper side parallel to the base surface area and two narrow face surface areas. Molded to the narrow sides of these face surface areas remote from the base surface area is a vertically projecting flange  24 . The flanges  24  comprise two connecting surface areas  24   a  capable of being brought in snug contact with the sidewalls of the module housing. Molded to the base surface area are two tabs  26  protruding beyond the main surface areas. The arrangement of the tabs  26  on both sides of the base body  22  is unsymmetrical. The tabs  26  each comprise at least one pin  28  projecting toward the upper side. The two centering pins  28  of each connecting element  14  differ in size and/or shape. 
     On each of the base surface areas lying opposite to the keys  20 ,  21 , respectively, recesses  32 ,  33  are formed juxtaposed to centrally arranged shafts  30 ,  31 , respectively, the recesses  32 ,  33  each corresponding in size, shape and arrangement to the tabs  26  with the centering pins  28 . 
     In fitting the multiple switch  10  first the adjoining module housing  11 ,  12  is prelocated by inserting the tabs  26  with the centering pin  28  of a connecting element  14  into the corresponding recesses  32 ,  33  of the module housing  11 ,  12 , the connecting surface areas  24   a  of the flanges  24  thereby engaging below the support collar  16 ,  17 . The polarization afforded by the differing sizes of the centering pins  28  prevents the switch units from being oriented the wrong way round, i.e. turned through 180°, in the multiple switch  10 . The module housings  11 ,  12  are then precisely aligned in a template. Subsequently a final location is achieved by welding, preferably ultrasonic welding, in the region of the connecting surface areas  24   a , as indicated by the reference numeral  36 ,  37  in FIG.  1 .