EP0786787B1 - Self-adjusting tappet-switch - Google Patents

Description

The invention relates to a self-adjusting plunger switch with the features of the preamble of claim 1.

Self-adjusting plunger switches are already in many different types Embodiments known in the art. she are used, for example, in vehicles as brake light switches. Switches designed in this way serve the purpose of Tolerances when installing the switch or changes in the actuation path of the actuator, e.g. of the brake pedal. For this purpose, self-adjusting plunger switches have a Housing of the switch slidably guided actuator to actuate at least one contact, which consists of a in the housing guided slide and with this in the direction of actuation adjustably connected plunger. The pestle is usually snapped connected to the slide, so that the desired switching point of the switch by adjusting the Ram can be achieved in the slide.

The self-adjusting switch is initially in the desired position Position installed in the vehicle, with the plunger in the am farthest position from the slider with this is locked. After installing the switch, the actuator, e.g. the brake pedal, powerful in the direction of actuation moves, which initially moves the slide to its end position and then the plunger with its locking area accordingly is pushed far into the slide. This will Tolerances when installing the switch or in the actuation path of the brake pedal balanced. This also results from this the advantage that with a sufficiently large rest area between Plunger and slide damage the switch in the In the event of a change in the actuation path, e.g. the pedal travel, is safely avoided.

DE 35 27 874 A1 describes a self-adjusting plunger switch with a hollow cylindrical shaft part, which in a Hole of a plate can be used. At one end that points Shaft part on its inner surface at least one inwards protruding locking lug on a thread Engages shaft. The shaft is part of the Switching device and has a switch button on one side and on the other side a switch housing in which the Contact elements are located. For adjusting the switching device the switch button is actuated by an actuator, e.g. a Brake pedal, applied, the shaft in the shaft part so is pushed back far until the switch button in relation to the Actuating element has the desired distance.

From DE 29 21 439 A1 a plunger switch is known, the can be used in particular as a brake light switch, the Tappet switch through a sleeve that is used to attach the Switch is used in an assembly opening as long as pushed until the tappet touches the brake pedal and the End surface of the shaft rests against the pedal. The desk is then rotated through a limited angle with respect to the sleeve, ribs and grooves of the switch with corresponding Ribs and grooves of the sleeve are engaged. On in this way the switch is fixed axially with respect to the sleeve.

However, the known self-adjusting plunger switches have the disadvantage that under certain circumstances an unwanted Adjustment of the desired locking position between the plunger and Slider can occur, in particular the thermal expansion of switch components or wear of the rest areas can contribute. Also fiddling around Switch can lead to an unintentional adjustment of the desired Guide the rest position (after self-adjustment). This results in a shift of the switching point, so that for example, the brake light only from a certain position of the brake pedal is switched on, in which one considerable braking effect is achieved. Before this switching point the vehicle following this vehicle receives no information on the braking process already started.

The present invention is therefore based on the object to create a self-adjusting plunger switch in which after self-adjustment of the ram self-adjustment the relative position between the plunger and slide is securely fixed is.

The invention solves this problem with the features of the claim 1.

By providing the first locking means on the plunger, which in one that allows the adjustment between the plunger and slide Angular position (adjustment position) out of engagement with am Slider provided second locking means are at the self-adjusting plunger switch according to the invention guaranteed before a simple self-adjustment.

After self-adjustment, the first on the ram provided locking means, however, by rotation about one predetermined angular amount with that provided on the slide second locking means are engaged, whereby the position between the plunger and slide can be locked is. No adjustment can be made in this locking position of the plunger more relative to the slide, so that a unintentional adjustment of this position safely excluded is.

In addition, this locking option has the advantage that a new rotation of the plunger into the adjustment position another adjustment process can be carried out. For example, this is then necessary if the braking device has to be readjusted and thus a change in the pedal travel took place.

In the preferred embodiment of the invention, the Ram in a known manner in an axial recess of the slide a, the first locking means on this in the Slide engaging area of the plunger and the second locking means on the corresponding part of the slide are provided.

Of course, it is also conceivable that in reverse Way of the plunger has an axial recess in which a Extension of the slide engages accordingly. The first and second locking means are then to be provided accordingly.

In the preferred embodiment of the switch according to the invention have at least the first and second locking means a rest and a counter-rest interacting with it, the one Form ratchet.

The second locking means can be a resilient arm include, which in the recesses of the first locking means engaging rest. This results in a special one simple and inexpensive construction as well as a simple Assembly of the individual switch elements.

At least the steepness of those pointing in the direction of actuation Flanks of the wells of the at least one rest must be so be chosen that the latch and the resilient arm at least in the Actuating direction of the plunger act as a lock. To this Way is an adjustment of the plunger in the locking position excluded relative to the slide in the actuation direction. On the other hand, the plunger can be made by applying a sufficient amount Traction against the direction of actuation from the slide be pulled out. This way, in cases, in which are the actuating part for the plunger / slide system its starting position further from the outer end of the plunger has moved away, the plunger also readjusted in its locking position become.

However, preferably both sides of the at least one rest chosen in its steepness so that the rest and the resilient arm act as a ratchet in both directions.

In the preferred embodiment of the invention, the radius is of the plunger in the area of the at least one rest of the first Locking means selected so that plunger or latch and inner wall the axial recess of the slide, the radial movement of the limit at least one resilient arm in the locking position so that a locking effect in the direction of the longitudinal axis of the Ram enters. In other words, even if the slope the flanks of the rest is chosen so that together with the resilient Arm a latching shift between ram and Slider would be possible by limiting the radial Movement of the resilient arm in the locking position has a locking effect reached.

Furthermore, the preferred embodiment of the invention Switch the ram radius in the area of at least one long side of the plunger, which is in the adjustment position of the plunger with the at least one resilient arm interacts, chosen so that the plunger and inner wall of the axial Recess of the slide the radial movement of the least ensure a resilient arm so far that an adjustment of the plunger is made possible relative to the slide.

In this way, at least one long side of the Tappet in the adjustment position with the at least one interacts with the resilient arm, an adjustment catch can be provided, the one in connection with the at least one resilient arm latching adjustment between ram and slide allows.

In the preferred embodiment of the invention, the Ram a substantially circular cross section with at least a flattening, with the flattened long side in the adjustment position with the at least one resilient arm cooperates. In this case, the recess of the slide, in which the plunger engages, for example also one have circular cross-section, its diameter in essentially corresponds to the maximum diameter of the ram. In this way it is ensured that the resilient arm in the Locking position practically completely from a deepening of the the first locking means forming catch is received or limited at least in this way in its radial direction of movement is that locking of the plunger is ensured.

In the preferred embodiment of the invention, the spring is designed as a U-spring and the plunger has one essentially circular cylindrical shape with flattened opposite one another Pages on. The adjustment position is in this case then when the plunger is in that angular position is located, in which the flattened long sides essentially lie parallel to the two spring arms. In this position the two spring arms can go as far in the radial direction be bent out that a latching adjustment of the plunger relative to the slide is possible.

By rotating the plunger through 90 °, the two remain resilient arms in the same circumferential recess, however this due to the enlarged diameter in this position moved so far in the radial direction that another radial resilient movement of the arms is prevented. this leads to for a secure locking of the ram.

In the preferred embodiment of the invention that is at least a resilient arm angled slightly in its front area such that this angled area the at least engages behind a flattened side of the plunger, so that this the spring is prevented from falling out. So it will the spring pops out when the plunger rotates prevents and also snagging the plunger with the slide avoided.

In the preferred embodiment of the invention, the plunger has at least one longitudinal groove, which with at least one Projection on the inner wall of the axial recess of the slide cooperates so that a locking of the rotational movement of the Slider in the locking position and / or the adjustment position he follows. The at least one projection can be on a partial area the wall of the slide can be provided, which as resilient tongue is formed.

In the preferred embodiment, the at least one Projection at the same time as a stop to limit movement of the plunger relative to the slide in the direction of actuation serve the plunger opposite direction of the plunger and To do this, cooperate with a stop surface provided on the plunger.

Further embodiments of the invention result from the Subclaims.

Fig. 1

einen Längsschnitt durch eine Ausführungsform des Schalters nach der Erfindung;

Fig. 2a

eine teilweise aufgebrochene Seitenansicht des Schiebers mit darin montiertem Stößel gemäß Fig. 1;

Fig. 2b

einen Längsschnitt durch Fig. 2a in einer Ebene senkrecht zur Zeichenebene;

Fig. 2c

einen Querschnitt entlang der Linie I-I in Fig. 2b;

Fig. 2d

eine Darstellung gemäß Fig. 2c bei 90 ° gedrehtem Stößel;

Fig. 3a

eine Seitenansicht des Stößels;

Fig. 3b

eine Seitenansicht des um 90° um seine Längsachse gedrehten Stößels;

Fig. 3c

einen Schnitt durch den Stößel entlang der Linie I-I in Fig. 3a und

Fig. 3d

einen Schnitt durch den Stößel entlang der Linie II-II in Fig. 3b.

The invention is explained in more detail below with reference to an embodiment shown in the drawing. The drawing shows:

Fig. 1

a longitudinal section through an embodiment of the switch according to the invention;

Fig. 2a

a partially broken side view of the slide with the plunger mounted therein according to FIG. 1;

Fig. 2b

a longitudinal section through Figure 2a in a plane perpendicular to the plane of the drawing.

Fig. 2c

a cross section along the line II in Fig. 2b;

Fig. 2d

a representation of Figure 2c with 90 ° rotated plunger.

Fig. 3a

a side view of the plunger;

Fig. 3b

a side view of the plunger rotated by 90 ° about its longitudinal axis;

Fig. 3c

a section through the plunger along the line II in Fig. 3a and

Fig. 3d

a section through the plunger along the line II-II in Fig. 3b.

The embodiment of a self-locking shown in Fig. 1 Tappet switch 1 according to the invention consists essentially from a housing 3 in which a slide 5 is longitudinally displaceable is led. Contacts 7 are arranged in the housing, whose connecting ends 7a in a socket part la of the housing 3rd are guided to the outside, so that these connection ends 7a by means a suitably designed connector (not shown) contacted can be.

The slide 5 has a recess 9 on its underside Recording the end of a coil spring 11. The other end the coil spring 11 is supported on the bottom 13 of the housing 3, so that the slide 5 is acted upon by the coil spring 11 is that it is held in its rest position, which by the stop surfaces 15, 17 of the slide 5 or the housing 3 is set. A moving contact 19 is provided on the slide 5, which is in a direction perpendicular to the longitudinal axis of the Switch is resiliently mounted. This contact has two spherical sections 19a, each on the surface of a of the two fixed contacts 7 slides. In the starting position the slide 5 is therefore the contact between the two stationary contacts 7 and thus between the two connection ends 7a closed.

Is the slide against the force of the coil spring 11 with pressurized, the slide is in as long this direction until it hits the two stop ends 21 abuts the bottom 13 of the housing 3.

With this movement, the moving contact becomes from a certain point Position lifted from the fixed contacts 7 because between an elevation 23 is formed in the two stationary contacts is. From this predetermined position of the slide 5 is therefore the contact between the two fixed contacts 7 and so open between the two connection ends 7a.

Of course, the contacts can also be any be trained differently. For example, the contacts can be used as NO contacts function or multiple contacts can be provided.

In an axial, essentially circular cylindrical recess 25 in the slide 5, a plunger 27 is arranged, which one Has longitudinal region 27a, on which a catch is formed. The Recesses and projections of the rest are preferred provided all around. By means of this rest and one interacting with it The spring (Fig. 2) of the plunger 27 can be locked in place Recess 25 in the slider 5 adjustable. This will make the desired function of self-adjustability guaranteed.

For the sake of completeness it should be mentioned that between a head 31 of the plunger 27 and the housing 3, a bellows 33 as protection against contamination can be provided. This made of elastic Material existing bellows 33 engages at both ends provided beads in corresponding grooves on the head 31 of the plunger 27 or at the top of the housing 3.

The lockability of the plunger 27 according to the invention in the slide 5 is explained in more detail below with reference to FIGS. 2 and 3. Of the The plunger 27 shown in FIG. 3 consists of a shaft 35 which the aforementioned longitudinal region 27a with a catch is formed as well as from the head 31 and a foot 37. The head 31 and the foot 37 each have a circular cylindrical shape Cross section on.

The shaft 35 has opposite one another in its longitudinal region 27a flattened long sides 39. The ones in this area all around trained rest, as will become clear later 39, therefore, on the flattened long sides 39 adjustment latches 41 and on the remaining partially circular cylindrical outer surfaces 43 first locking means or locking catches 45 arise (Fig. 2a and Fig. 2c).

The plunger 27 has in the remaining part 27b of the shaft 35 an approximately oval cross-section, with the narrow Longitudinal longitudinal grooves 47 are formed.

As can be seen from Fig. 2a, the one with a circular cylindrical Wall-formed part of the plunger 5, in which the Recess 9 is provided for receiving the plunger 27, one Area 49 for receiving the spring 29. The spring 29 is as U-spring formed and engages with angled arms 29a corresponding openings in the cylindrical wall of the slide 5 into the recess 9. For better guidance of the arms 29 a can 9 guide grooves on the inner wall of the recess be trained. Because preferably on opposite sides an area 49 of the cylindrical wall of the slide 5 is designed to receive a spring 29, the result in 2c and 2d shown cross section along the line I-I in Fig. 2b. The wedge-shaped shown in FIGS. 2c and 2d Crosspieces 49a serve for easier insertion of the Ends of the spring arms 29a in the recesses 49b.

Although on opposite sides of the slide 5 each one Area 49 for receiving a spring 29 is provided for Locking the plunger 27, of course, only one Spring needed, however, received by each of the areas 49 can be.

The formation of the spring 29 as an angled U-spring gives the Advantage of simple assembly and a simple bracket in the Slider 5, with an additional long training the spring arms, i.e. the angled arms 29a and connected with it extending parallel to the longitudinal axis of the slide Arm pieces setting virtually any setting you want Spring constant is possible.

The function of the switch according to the invention thus arises is as follows:

To install the switch, for example as a brake switch first the plunger only so far in the slide 5 when inserted Spring 29 inserted until the plunger 5 with the first recess the adjustment latch 41 is latched with the arms 29a of the spring 29. Of course, the plunger 27 must be in this position Recess 9 of the slide 5 are used that the flattened Long sides 39 of the longitudinal region 27a parallel to the Poor 29a run. The complete with one in this adjustment position located system from plunger 27 and slider 5 is then mounted in the desired position in the vehicle.

After installation is complete, the actuator for the switch, for example, the brake pedal, pressed hard, so that in self-adjustment in the manner already described above of the plunger relative to the slide.

After self-adjustment, the plunger 27 is moved around manually rotated about 90 °, in the lower region of the recess 9 of the Slider 5 provided locking lugs 51 (Fig. 2a) in the longitudinal grooves engage on the narrow sides of area 27e of plunger 27. The cross section of the shaft 35 in the region 27b is designed such that that for the rotary movement of the plunger and the locking with the locking lugs 51 the desired force curve is created. Of course, the spring force of the spring arms is also used for this 29a and their interaction with area 27a is decisive. In this position there is a locking between the plunger and Slider, since the diameter of the plunger in the area according to FIG. 2c the partially circular cylindrical outer surface 43 or the locking catches 45 is selected so that the spring arms 29a on the inner wall the recess 9 of the slide 5 or in the provided therein Guide grooves are pressed.

The locking between the longitudinal grooves 47 and the locking lugs 51st is preferably designed so that a rotational movement of the Tappet by 90 ° from the locking position to the adjustment position or vice versa possible in any direction is.

As can be seen from Fig. 2a, the detents 51 also meet the Abandon a stop, since this with the stop surfaces 37a of the foot 37 in the region of the broad sides of the region 27b of the Shaft 35 in the adjustment position of the plunger 27 pulling it out prevent from the recess 9 of the shaft 5.

Claims (16)

1. Self-adjusting tappet switch,

   a) having a housing (3) for receiving at least one contact (7, 19) which is to be actuated,

   b) having an actuating element (5, 27) which is guided displaceably in the housing and is intended for actuating the at least one contact (7, 19),

   c) it being the case that the actuating element is retained in a rest position, in which it is pushed out of the housing, by a resilient element (11),

   characterized in that

   d) the actuating element comprises a slide (5), which is guided in the housing, and a tappet (27), which is connected to said slide such that it can be adjusted in the actuating direction, and

   e) in that the tappet (27) has first securing means (45) which, by way of a rotary movement of the tappet (27) by a predetermined angle about its longitudinal axis, can be moved out of an angled position, which allows the adjustment between the tappet (27) and the slide (5) and defines the adjustment position, into engagement with second securing means (29a) of the slide, as a result of which the securing position is defined and it is possible to secure the position between the tappet (27) and slide (5).
2. Switch according to Claim 1, characterized in that the tappet (27) engages, by way of a sub-region (27a), into an axial recess (25) of the slide, and in that the first securing means (45) are provided in this sub-region (27a) of the tappet (27) and the second securing means (29a) are provided on the corresponding sub-region of the slide (5).
3. Switch according to Claim 1 or 2, characterized in that the first securing means (45) and second securing means (29a) are designed in the form of at least one catch and at least one mating catch interacting therewith, the two catches forming a locking mechanism.
4. Switch according to Claim 3, characterized in that the second securing means have at least one resilient arm (29a), which engages in the depressions of the at least one catch, which forms the first securing means (45).
5. Switch according to Claim 4, characterized in that the second securing means are designed as a U-spring (29), of which the arms (29a) interact with in each case one catch (45) on opposite longitudinal sides of the tappet (27).
6. Switch according to Claim 4 or 5, characterized in that at least the gradient of the flanks of the depressions of the at least one catch (45), said flanks being oriented in the actuating direction, is selected such that the catch and the at least one resilient arm (29a) act as a locking mechanism at least in the actuating direction of the tappet (27).
7. Switch according to one of Claims 4 to 6, characterized in that the radius of the tappet (27) in the region of the at least one catch (45) is selected such that the tappet (27) and inner wall of the axial recess (25) of the slide (5) limit the radial movement of the at least one resilient arm (29a) in the securing position such that a blocking action takes place in the direction of the longitudinal axis of the tappet (27).
8. Switch according to one of Claims 4 to 7, characterized in that the radius of the tappet (27) in the region of the at least one longitudinal side (39) of the tappet (27), which in the adjustment position of the tappet interacts with the at least one resilient arm (29a), is selected such that the tappet (27) and inner wall of the axial recess (25) of the slide (5) allow the radial movement of the at least one resilient arm (29a) to the extent that displacement of the tappet (27) relative to the slide (5) is made possible.
9. Switch according to one of Claims 4 to 8, characterized in that provided on the at least one longitudinal side (39) of the tappet (27), which in the adjustment position interacts with the at least one resilient arm (29a), is an adjustment catch (41) which, in conjunction with the at least one resilient arm (29a), allows a latching adjustment between the tappet (27) and slide (5).
10. Switch according to one of Claims 4 to 9, characterized in that the axial recess (25) has an essentially circular-cylindrical cross section.
11. Switch according to Claim 10, characterized in that the tappet (27) has an essentially circular cross section with at least one flattened portion, it being the case that, in the adjustment position, the flattened longitudinal side (39) interacts with the at least one resilient arm (29a).
12. Switch according to Claim 11, characterized in that the end of the at least one resilient arm (29a) is of slightly angled design.
13. Switch according to one of the preceding claims, characterized in that the tappet (27) has first latching means (47) which are intended for fixing the adjustment position and/or the securing position and interact with second latching means (51), which are provided on the slide (5).
14. Switch according to Claim 13, characterized in that the first latching means are designed as at least one longitudinal groove (47) which interacts with at least one protrusion (51), which is designed as the second latching means and is located on the inner wall of the axial recess (25), or vice versa.
15. Switch according to Claim 14, characterized in that the at least one protrusion (51) is provided on a sub-region of the wall of the slide (5) which is designed as a resilient tongue.
16. Switch according to Claim 14 or 15, characterized in that the at least one protrusion (51) serves, at the same time, as a stop for limiting the movement of the tappet (27) relative to the slide (5) in the direction counter to the actuating direction of the tappet, and for this purpose said protrusion interacts with a stop surface (37a) provided on the tappet (27).

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