Patent Application
20080073119
The invention will be described hereinafter in greater detail using embodiments and with reference to the enclosed drawings, in which:
The invention will now be described in greater detail with reference to a flexible, flat electrical cable 1, hereinafter referred to as a flat cable 1, for a motor vehicle coil spring. However, is not to be restricted to a flat cable of this type but rather relates to electrical cables in general requiring correctly orientated installation or correctly oriented assembly/manufacture.
In the case of flexible flat cables (FFCs), a distinction is drawn between extruded flexible flat cables (exFCs) and flexible laminated cables (FLCs). Also included in this field are what are known as flexible printed circuits (FPCs).
Flexible laminated cables consist of preferably a plurality of electrical flat conductors 20 which are arranged parallel to one another between two electrically insulating cover sheets. These cover sheets are conventionally joined together using an adhesive and enclose between them the flat conductors 20 of the flat cable 1. The flat conductors 20 are set apart from one another and electrically insulated from one another by the adhesive and/or the insulating cover sheets.
Extruded flexible flat cables 1 consist preferably of foil-like copper strips which are electrically insulated from one another using a thin, adhesive-free plastics material layer and are joined together in an extrusion process to form a single strip. The advantage of extruded flat cables 1 is that they contain no adhesive, allowing flat cables 1 to be stripped without residue in the window 40. The absence of an adhesive also means that such cables are more environmentally friendly to manufacture and dispose of.
Flexible flat cables 1 are used as connection cables in a large number of applications, especially in applications in which little overall space is available. In addition, flexible flat cables 1 are preferably used in applications in which two elements which can be moved in opposing directions are electrically connected to each other, such as is the case, for example, with an electrical rotational transmitter, such as a coil spring on a motor vehicle steering system, or a movable print head.
As flat cables 1 are used for transmitting power and, preferably in another electrical conductor of the cable, also for transmitting signals (higher electrical currents being required for transmitting power, with lower transmission quality), the flat cable 1 has to be installed, fitted or manufactured correctly oriented or in a correct position in a component.
According to the invention, an orientation marker is incorporated for this purpose in an electrical cable 1, shown in
The orientation marker according to the invention has at least one recess 50. A recess 50 of this type is a molding (indicated in broken lines at the bottom of
The term “recess 50”, as used hereinafter, refers to any kind of removal of material from a flat cable 1. This is, in particular, removal of any kind of initial contour of the flat cable 1, for example that of a flat conductor 20, hereinafter referred to as flat conductor 20, and/or an electrical insulating material 30, or an indentation or else a contour, produced by the removal of material, on the flat cable 1 (shown in the top left-hand corner of
In addition, it is possible to provide the orientation marker according to the invention by adding material to the flat cable 1, as may be seen in
The orientation marker according to the invention is preferably located on/in or in proximity to a stripped region 40, herein referred to as a window 40, of the flat cable 1. This window 40 is used for electrically connecting the flat cable 1.
Furthermore, the orientation marker according to the invention is generally to be provided in or on the flat cable 1 so as to be positioned not completely symmetrically with respect to an axis L, Q of the flat cable 1, said axes mapping onto one another at least two regions and/or outer edges of the flat cable 1.
The orientation marker according to the invention has at least one recess 50. Three recesses 50 in the form of indentations are thus provided, for example, in a lower longitudinal edge region 16 of the flat cable 1. Each one of these three indentations may be regarded as a single orientation marker according to the invention. An exemplary embodiment of the invention has a recess 50 on a transverse end 11 of the flat cable 1. In this case the recess 50 is also located in a transverse edge region 19 of the flat cable 1 (shown in the bottom right-hand corner of
It is also possible to form the orientation marker according to the invention by a recess 50 in the flat conductor 20. This is possible either in the electrical insulating material 30 of the flat cable 1 (elliptical recess 50 on the right-hand side, next to the window 40 of
In addition, it is possible to provide an orientation marker according to the invention in a region of the electrical insulating material 30 and/or in a region of a flat conductor 20. This may be, for example, a recess 50 which is in the form, for example, of a slot in a longitudinal central region of the flat cable 1 and is shown in
The orientation marker used may also, for example, be a recess 50 in the form of a punched ellipse shown in
In addition, it is possible to form the orientation marker from a plurality of recesses 50. A large number of embodiments of the invention are possible in this case. Thus, for example, it is possible to provide punched holes asymmetrically with respect to a surface center point M of a longitudinal side 12, a transverse axis Q and/or the longitudinal axis L of the flat cable 1. This is illustrated, for example, in the right-hand region of
Obviously, the above-mentioned possibilities may be combined with one another.
Generally, for all embodiments of the invention, a molding, a recess 50 or a through recess 50 may be of any desired shape provided that its respective position and/or other shape allows a flat cable 1 to be positioned in all cases with correct orientation (for a predetermined assembly rule).
According to the invention, the orientation marker is preferably located on/in or in proximity to the window 40 of the flat cable 1. According to the invention, this allows the orientation marker to be provided immediately during manufacture of the flat cable 1. This is carried out, for example, using what is known as the window 40 method which punches a window 40 into one or both cover sheets of a flat cable 1 to be produced by lamination. There is provided in this case, in addition to the window 40 stamp or stamps, at least one further stamp which punches the orientation marker into one or both cover sheets. This may also be provided using a single punching stamp having at least two stamped elevations.
In addition, other methods for stripping the window 40 are also suitable for providing the orientation marker according to the invention. For example, during scraping, grinding and milling, this is possible because of an additional machining step or by omitting a corresponding machining region. Thus, during stripping, it is, for example, possible, as shown on the window 40 at the top of
Furthermore, one or more recesses 50 in the orientation marker may be used as positioning recesses 50 for receiving pins for guiding a counterpart component. According to the invention, this allows the flat cable 1, on the one hand, to be correctly positioned and, on the other hand, to be provided with correct orientation, for example in a connector or during electrical connection to a component.
For the sake of optimally simple visual and/or tactile positioning of the flat cable 1, the orientation marker may be provided, for example, on an edge region 16, 19 remote from an axis L, Q or a center point M of the flat cable 1. Furthermore, the orientation marker according to the invention is may provided in/on or in proximity to the window 40 of the flat cable 1.
The invention is advantageous in the case of cables subjected to a punching or cutting process during manufacture thereof. This is the case, in particular, with flat cables 1 which are cut or punched, for example on cutting-to-length or during manufacture thereof. A punching process of this type is carried out, for example, during manufacture of a flat cable 1 using what is known as a window 40 method in which a flat cable 1 to be laminated is subjected to a punching process prior to adhesion of two insulating layers using at least one window 40 stamp. In this case, one or both insulation films to be adhered is/are punched, the flat cable 1 subsequently not being electrically insulated in the punched region. The invention therefore allows the provision of a recess 50 according to the invention on/in the flat cable 1 using an additional punching tool as well as a window stamp or an otherwise configured window stamp. A laminated flat cable 1 gives rise merely to one-off additional costs resulting from minimal additional expenditure in the production of a new punching tool. According to the invention, it is thus possible to convert an existing cable production line so as to allow the orientation marker according to the invention to be provided in/on the cable. Instead of imprinting or affixing a sticker, recesses or through-recesses, the shape, number or position of the recesses on/in the cable being variable, provide correctly oriented installation of the cable.
The foregoing illustrates some of the possibilities for practicing the invention. Many other embodiments are possible within the scope and spirit of the invention. It is, therefore, intended that the forgoing description be regarded as illustrative rather than limiting, and that the scope of the invention is given by the appended claims together with their full range of equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102006044939.8 | Sep 2006 | DE | national |
