Technical Field
The present invention relates to an electric switch provided with a multi-part housing.
Background Art
Certain electrical switches--in particular those using the Hall effect--are provided in order precisely to switch on and off an electric circuit with the lowest possible switching hysteresis. Such switches are provided, for example, for the most widely differing operational regions in motor vehicles and are, for example, used as brake light switches, gear switches etc.
DE 33 33 497 A1 discloses electric switch, wherein two permanently magnetized components are disposed in a housing comprised of a plurality of parts, their poles comprising the same polarization, are disposed oppositely and spaced apart. Between these poles of the two permanently magnetized components, a Hall effect switching component is disposed. The first permanently magnetized component is thus fixed to the actuating member of the switch, while the second permanently magnetized component is held in an adjustable manner on the housing. The spacing between the second permanently magnetized component and the Hall effect switching component is set in this electric switch by means of an adjusting means, wherein the second permanent magnet is fixed directly on the adjusting means. In a device formed in this way the two permanently magnetized components, the Hall effect switching component, and the holding means provided therefor are subjected to all the environmental conditions prevailing in the housing. Under aggressive environmental influences the Hall effect switching component and the associated holding means may deteriorate with respect to their operational capability. This can eventually lead to the failure of the electric switch.
DE 33 37 122 C2 also discloses an electric switch which consists of an actuating member formed as a push button and held in a longitudinally adjustable manner in an upper housing part and of a movable switching member disposed in a lower housing part and formed from a switching mat. A nonmovable switching member is disposed on an insulating material plate held on the lower part of the housing. The switching members are formed from different electrode layers. By the division of the housing into an upper housing part and a lower housing part and the arrangement of the switching mat and of the actuating member a spatial separation of the actuating member and switching members is produced.
DE 41 19 316 C1 also discloses an electric switch in which in a housing consisting of a number of parts, two housing chambers are provided hermetically separated from each other and formed by a separating wall provided on the housing. A permanently magnetized component is thus allocated to the actuating member of the switch disposed in one housing chamber, while in the other housing chamber, a Hall effect switching component which can be influenced by the permanently magnetized component is provided. The permanently magnetized component and the switching component are thus allocated to the two sides of the separating wall and arranged opposite each other.
In all the aforementioned embodiments the problem exists that only one electric switching function (on/off) is possible.
Summary of the Invention
It is therefore the aim of the present invention to develop an electric switch that provides a number of associated switching functions.
This object is achieved by the features stated in the characterizing part of the main claim. An electric switch formed in this way is particularly advantageous in that it comprises only relatively few mechanically operated parts. Such a product is particularly resistant to wear so that high numbers of position changes can be reliably achieved.
Brief Description of the Drawings
Further particularly favorable embodiments of the subject matter in accordance with the invention are given in the sub claims and described in more detail with the aid of an embodiment illustrated in the drawings, in which:
FIG. 1 illustrates a longitudinal sectional view along the line A--A of FIG. 2 of the electric switch;
FIG. 2 illustrates a longitudinal sectional view along the line B--B of FIG. 3 of the electric switch in accordance with FIG. 1; and
FIG. 3 illustrates a transverse sectional view along line C--C of FIG. 2 of the electric switch in accordance with FIGS. 1 and 2.
Best Mode for Carrying Out the Invention
As is evident from the drawings, an electric switch in accordance with the invention comprises a substantially rotationally symmetrical multi-part housing 1 consisting of an upper housing part 1a and a lower housing part 1b. In the upper housing part 1a are disposed two actuating members 3a.sub.1, 3a.sub.2 in two housing chambers 2a.sub.2, 2a.sub.2 provided there. These actuating members 3a.sub.1, 3a.sub.2 are each supported against the chamber floor with one of their end regions 3a.sub.1 ", 3a.sub.2 " by a resilient element 4a.sub.1, 4a.sub.2 formed as a helical compression spring, while they protrude with their other (free) end region 3a.sub.1 ', 3a.sub.2 ' out of the associated housing chamber 2a.sub.1, 2a.sub.2 on the side of the upper housing part 1a remote from the lower housing part 1b. In order that the actuating members 3a.sub.1, 3a.sub.2 which can be influenced, for example, by a cam-shaped operating means, do not fall out of the associated housing chamber 2a.sub.1, 2a.sub.2 holding element 6 is allocated to them and partially closes the housing chambers in such a way that only the narrowed free end regions 3a.sub.1, 3a.sub.2 of the actuating members protrude out of the associated housing chamber, while the other end regions 3a.sub.1 ", 3a.sub.2 " the actuating members located in each housing chamber is supported against the holding element by a shoulder-like projection 3a.sub.1 **, 3a.sub.2 ** by reason of the force applied by each associated resilient element 4a.sub.1, 4a.sub.2.
At the outermost end of the end regions 3a.sub.1 ', 3a.sub.2 ' of each of the two actuating members protruding out of the housing chambers 2a.sub.1, 2a.sub.2 is attached a roller-shaped displacement element 5a.sub.1, 5a.sub.2 in order to render possible problem-free actuation of the actuating members 3a.sub.1, 3a.sub.2 by the associated cam-shaped operating means.
Close to the end regions 3a.sub.1 ", 3a.sub.2 " of the actuating members 3a.sub.1, 3a.sub.2 comprising a rectangular cross section, lying in each housing chamber 2a.sub.1, 2a.sub.2 a permanently magnetized component 7a.sub.1, 7a.sub.2 is inserted at each longitudinal side of the actuating members in such a way that it is disposed with its element of magnetic action (magnetic pole surface) parallel to and very slightly spaced from the one side 1c.sub.1 ', 1c.sub.2 ' of the separating wall 1c.sub.1, 1c.sub.2.
On the other side 1c.sub.1 ", 1c.sub.2 " of the separating wall two switching components 8a.sub.1 ', 8a.sub.1 "; 8a.sub.2 ', 8a.sub.2 " preferably using the Hall effect and which can be influenced by the permanently magnetized components 7a.sub.1, 7a.sub.2 provided on the two actuating members 3a.sub.1, 3a.sub.2 are disposed in a respective housing chamber 2b formed by the assembly of the upper housing part 1a and lower housing part 1b. These switching components 8a.sub.1, 8a.sub.1 "; 8a.sub.2 " are disposed one behind the other in pairs in the displacement direction of each of the two actuating members 3a.sub.1, 3a.sub.2 and therefore with the displacement of each actuating member come into the region of influence of the associated permanently magnetized components 7a.sub.1, 7a.sub.2.
Both switching components 8a.sub.1 ', 8a.sub.1 "; 8a.sub.2 ', 8a.sub.2 " allocated to a respective actuating member 3a.sub.1, 3a.sub.2 are fixed on a printed circuit board 9 which may be fitted with electronic components, the circuit board being held in oppositely lying guide grooves le.sub.1, le.sub.a which are provided on housing wall portions 1d.sub.1, 1d.sub.2 formed on the upper housing part 1a and provided in the housing chamber 2b. The tracks provided on the printed circuit board 9 and electrically connected to the switching components 8a.sub.1 ', 8a.sub.1 "; 8a.sub.2 ', 8a.sub.2 " are connected to connection ends 10* which are provided on contact parts 10 of which the other ends 10** are formed as outwardly directed plug contact elements surrounded by a housing collar 1f.
Because a such switch can be used, for example, as a so-called shifter, the housing 1 must, on the one hand, be formed in such a way that oil located in the transmission cannot penetrate into the housing chamber 2b, i.e. into the inner chamber fitted with the electrical components. To this end a surrounding annular sealing means 11 is disposed between the mutually cooperating hollow cylindrical regions of the upper housing part 1a and the lower housing part 1b. A further sealing means 12 provided on the upper housing part 1a prevents oil moving outward from the inner chamber of a transmission and in particular penetrating between the outer wall of the upper housing part 1a and the inner wall of an aperture provided to receive the housing.
The operation of the above-described switch will now be explained in more detail by reference to the operation of an actuating member.
In the rest position, illustrated in FIG. 1, of (one) actuating member 3a.sub.1 one of the switching components 8a.sub.1 ' is located in the region of influence of the permanently magnetized component 7a.sub.1 provided on the actuating member 3a.sub.1 and is therefore in its conducting state, while the other switching component 8a.sub.1 " removed from the permanently magnetized component 7a.sub.1 is in its blocked state. These two switching states of the two switching components 8a.sub.1 ', 8a.sub.1 " remain throughout a first displacement region of the actuating member 3a.sub.1, dependent upon the formation and arrangement of the permanently magnetized component 7a.sub.1 and its allocation to one of the switching components.
In a further displacement of the actuating member 3a.sub.1 beyond the first displacement region the one switching component 8a.sub.1 ' passes into its blocked state while the other switching component 8a.sub.1 " retains its blocked state.
These switching states of the two switching components 8a.sub.1 ', 8a" are maintained throughout a second (middle) region defined by the distance between the two switching components. Upon leaving the middle region and entering a third region the other switching component 8a.sub.1 " passes into its conducting state, while the one switching component 8a.sub.1 ' retains its blocked switching state. These states of the two switching components 8a.sub.1 ', 8a.sub.1 " then remain until the end 3a.sub.1 " of the actuating member 3a.sub.1 stops against the chamber floor and when the actuating member returns to its rest position corresponding changes of state take place for the two switching functions allocated to the switching components.
If the second actuating member 3a.sub.2 is constructed in exactly the same way with respect to its permanently magnetized component 7a.sub.2 and the switching components 8a.sub.2 ', 8a.sub.2 " are disposed in exactly the same way and therefore allocated accordingly, corresponding dependent control is made possible by different operation of the cam-like operating means cooperating therewith. Even greater degrees of freedom are achieved when the switching components 8a.sub.1 ', 8a.sub.1 "; 8a.sub.2 ', 8a.sub.2 " are differently allocated to the actuating members 3a.sub.1, 3a.sub.2 or when to each actuating member more than two consecutively arranged switching components or permanently magnetized components are allocated.