EP0849749B1 - Detent mechanism for push button switch - Google Patents

Abstract

The ratchet mechanism has a ratchet cam (18) attached to the push-button slider (12) cooperating with the bent guidance end of a wire hoop (24), which is moved along the cam surface upon operation of the push-button slider, for sidewards and subsequent location in a ratchet notch for holding the push-button slider in a defined position. The push-button slider has a shaped spring element for biasing the wire hoop on a direction transverse to the push-button axis.

Description

The invention relates to a locking mechanism in the Preamble of claim 1 specified genus. Such Locking mechanisms have become known in various designs. In all versions, the slides in the Backdrop guide rotating guide pin, which in general is formed by the angled end of a wire bracket along a locking profile and becomes in the course of its movement deflected to both sides of the key axis. When moving between the off position and the on position the guide pin must be at a deflection point of the Locking profile of the locking heart are passed. To a to ensure safe crossing of this deflection point, the deflection point is usually designed as a tip, so the bracket after a short deflection phase and a short return stroke by the force of the key return spring in the on position snaps into a recess. However, it has shown that by incorrect operation of the key slide the guide pin on the deflecting tip of the locking profile stop can. In this position the switch remains on, however, the key slide switches on the second Don't print, the wire bracket slides with his angled end in the ON position. Only after another Pressing the key slide switches off. This can lead to incorrect switching and to a device unintentionally remains in the switch-on position.

To avoid this dangerous operating condition three-dimensional rest hearts became known, in which still a flow curve is provided in the base of the resting heart.

It is necessary that the wire bracket by an additional Spring, generally by a leaf spring, on the Reason of the resting heart is pressed, or the wire bracket is given a complicated shape in such a way that the Back pressure spring the wire bracket to the bottom of the locking heart presses. These known designs have only a limited one Lifespan because of the wire hanger that is not always burr-free can be produced, buried in the raster heart. If the wire bracket must avoid this wear from the ridge burr-free, which is not insignificant in the manufacture more expensive.

DE 36 38 834 A1 describes a push lock device with a pivoted wire bracket, the Leader in a heart curve is running. Over the wire bracket a leaf spring is arranged so that it the free End of the guide pin against the bottom surface of the control surface groove the heart curve presses.

However, this leaf spring is not able to relate to one the guide groove of the heart curve lateral force on the Exercise leading end of the wire bracket.

The invention has for its object a simple, two-dimensional locking mechanism to create the avoids the described incorrect operations with certainty and the switching sequence OFF-ON-OFF with certainty when repeated Guaranteed key press.

The task is solved by the in the labeling part of claim 1 specified features.

The positioning force exerted on the side of the bracket prevents that the leading end remains on the deflection tip, even when the pivoting movement of the guide bracket deliberately by special Action is slowed down, causing a random movement prevented by its own weight in an unfavorable installation position shall be. In general, it will be enough Guide pin or wire bracket during the switching movement between the off position and the on position to suspend the lateral preload in such a way that the Wire bracket only from one side to the middle position is transferred or its transfer is supported.

With special designs of the locking mechanism, however, it can also be useful, the switching bracket from both sides pre-tension in the middle position or a pre-tension in a one-sided position.

A particularly simple and functional construction of a Push button switch with locking mechanism results from the Features of claim 3. Accordingly, for support of the wire bracket and plastic hook to prevent it from falling out are provided, which are molded onto the key slide are and overlap the wire bracket, one of the hooks retracts under self-elasticity when deflecting and a Force on the wire bracket.

Further refinements of the invention result from the Dependent claims.

Fig. 1   eine Teilansicht eines Drucktastenschalters mit dem erfindungsgemäßen Rastmechanismus, wobei der Drucktastenschalter in der 'Ein'-Stellung befindlich ist;

Fig. 2   eine Ansicht in Richtung der Tastenschieberachse;

Fig. 3   eine der Fig. 1 entsprechende Ansicht in einer Stellung kurz vor Erreichen der Einschalt-Stellung;

Fig. 4   eine der Fig. 2 entsprechende Ansicht in der Schaltstellung gemäß Fig. 3;

Fig. 5   eine Seitenansicht des Rastmechnismus im Schnitt;

Fig. 6   ein weiteres Ausführungsbeispiel eines Drucktastenschalters mit Rastmechanismus.

An embodiment of the invention is described below with reference to the drawing. The drawing shows:

Figure 1 is a partial view of a push button switch with the locking mechanism according to the invention, wherein the push button switch is in the 'on' position.

Figure 2 is a view in the direction of the key slide axis.

3 shows a view corresponding to FIG. 1 in a position shortly before reaching the switch-on position;

FIG. 4 shows a view corresponding to FIG. 2 in the switching position according to FIG. 3;

Fig. 5 is a side view of the locking mechanism in section;

Fig. 6 shows another embodiment of a push button switch with a locking mechanism.

In the drawing are only those for the locking mechanism according to the invention important parts of the push button switch shown, the push button switch itself can be arbitrary and in be known manner.

The push button switch has a slidable in a housing 10 stored key slide 12 on a plate 14 wearing. This plate forms the locking heart for the locking mechanism. This has a heart-shaped recess 16 in the plate 14 and one in the middle of the recess up to plate height protruding locking profile 18. The recess 16 forms its edge and in cooperation with the locking profile 18 one Link guide 20 for the angled guide end 22 of a Wire bracket 24, the other angled end 26 one opposite the leading end 22 has increased leg length and protrudes into a bore 28 of a bearing block 30 fixed to the housing and against which the key return spring 32 is supported.

When pressing the key slide 12 when pressed on the one hand and by the return movement of the return spring on the other is caused that the angled guide end 22nd of wire bracket 24 in the guide 20 of the dashed Line follows in the direction of the arrow. The angled forms End 26 a pivot pin for the bracket, which in Is pivoted to both sides in the course of its movement. The spring 32 loaded on the pivot pin 26 brakes the Swivel movement from, so that the wire bracket in the given The rest position remains, regardless of the installation position of the switch so that it is not by its own weight can fall into another position. In the fully awarded in Fig. 1 In the on position, the leading end 22 is in the switch-on position in a locking recess 34 of the locking profile 18, and in the Aysschalt position (dashed lines in Fig. 1 shown) the leading end is in the position 22 '. Both in the on position and in the Switch-off position, the wire bracket 24 is in the direction of Key slide axis.

On the plastic slide switch 12 are at right angles above two hooks 36 and 37 above molded a stem 38 and 39. Stems 38 and 39 can dodge elastically across the key slide axis. As can be seen from Fig. 2, the overlapping one another Hooks 36 and 37 over the wire bracket 24 and prevent one This bracket falls out.

To prevent the wire bracket 24 in the position according to Fig. 3 remains in the guide end 22 on the deflection tip 40 of the locking profile 18 comes to rest, the Handle 38 of the hook 36 an inwardly projecting extension 42 on. As can be seen from Fig. 4, the wire bracket lifts 24 during its lateral deflection between the off position and the on position the hook 36 over the 4 to the right, so that the stem 38th is resiliently biased inward towards the key axis, and this spring bias causes the leading end 22nd of the wire bracket 24 securely lifted over the deflection tip 40 is and under the action of the return spring 32 in the locking recess 34 (switch-on position) occurs. During the switching movement between the on position and the off position the leading end 22 to the other side after the Handle 39 deflected, but this handle is not deformed, because here the extension 42 is missing and the wire bracket 24 can dodge under the hook 37.

Fig. 6 shows a further embodiment of a push button switch with locking mechanism, in which the wire bracket 24a supported laterally by a plastic part 43 is. This plastic part is such on the key slide 12 attached that the wire bracket 24a in its deflection in Locking profile 18 is biased laterally by self-suspension. As soon as the bent end of the wire bracket 24a, which in the Locking profile runs, arrives at the top of the locking heart, the locking bracket jumps over the tip and snaps securely in the on position. Even with this push button switch a lateral force acts on the locking bracket, which through the pre-tensioning of the elastic wire bracket is produced. 1 to 5 the push button switch differs according to FIG. 6 by a much longer training of the wire bracket 24a, which in in this case by a bridging the key slide 12 Web 44 is secured against falling out. The plastic part 43 is integrally formed on the key slide and preferably has a spherical design. The return spring also presses here 32 on one end of the locking bracket. As from Fig. 6 can be seen, the key slide 12 has a central recess 46 between two side strips 48 in which the wire bracket 24a lies and by bridging the strips 48 Web 44 is secured against falling out. 6 right-hand bar, the spherical plastic part 43 is formed, which extends approximately so far inwards that the wire bracket is just touched in a stretched position and during movement its cranked end biased laterally in the raster heart becomes.

Reference list

10th

casing

12th

Key slider

14

plate

16

heart-shaped recess

18th

Locking profile

20th

Scenery tour

22

Leaders

24th

Wire bracket

26

The End

28

drilling

30th

Bearing block

32

Return spring

34

Rest recess

36, 37

hook

38, 39

stalk

40

Deflection tip

42

Continuation

43

Plastic part

44

web

46

Central recess

48

Afford

Claims (7)

1. Locking mechanism for a push-button switch, with a key shifter (12) which is operated upon by a return spring (32), with a heart-shaped latch (16, 18) for the elbow-shaped guiding end (22) of a wire bow (24), which end (22) passes along the heart-shaped curve upon actuation of the key shifter (12), making a lateral excursion, and after negotiating a reversing point (40) latches in a latching well (34) on the heart-shaped latch, with the result that the key shifter (12) is held in a defined shift position,
   characterised in that means (38, 42, 43) are provided which during the negotiation of the reversing point (40) operate on the guiding end (22) of the wire bow (24) at a right angle to the axis of the key shifter (12) and support the lateral excursion thereof.
2. Locking mechanism having the following features:

   a key shifter (12) is adapted to be displaced in a housing (18) against the force of a return spring (32);

   the key shifter (12) incorporates a heart-shaped latch (28);

   a wire bow (24) is inserted by an elbow-shaped anchoring end (26) as a pivot pin into a bore (28) of a pillow block (30) integral with the housing, and engages in the heart-shaped latch by its other, elbow-shaped guiding end (22);

   the swivelling movement of the pivot pin (26) is braked by the return spring (32) resting thereon;

   moulded laterally on the key shifter (12) are two flexible stalks (38, 39);

   the stalks (38, 39) carry hooks (36, 37) which engage over the wire bow (24) from both sides and stop it falling out;

   during a lateral excursion of the wire bow (24), at least one of the hooks (36) operates resiliently at a right angle to the key's axis on said wire bow and centres it.
3. Locking mechanism according to claims 1 or 2,
   characterised in that the key shifter (12) has a mouldedon spring element (38) which biases the wire bow (24) at a right angle to the key's axis onto the wire bow's middle position, in which it is situated parallel to the key's axis.
4. Locking mechanism according to claim 2,
   characterised in that the not less than one hook (36) has a continuation piece (42) which protrudes laterally from the stalk (38) and which operates laterally on the wire bow (24).
5. Locking mechanism according to claims 2 to 4,
   characterised in that the continuation piece (42) is situated in the plane of the hook (36).
6. Locking mechanism according to claim 1,
   characterised in that the wire bow (24a) is of resilient construction and cooperates with a rigid shoulder part (43) of the key shifter (12).
7. Locking mechanism according to claim 6,
   characterised in that the key shifter (12) incorporates a central recess in which the wire bow (24a) enjoys limited lateral mobility and that moulded laterally in the central recess (46) is a plastics part (43) which extends inwards and operates laterally on the wire bow (24a).

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