ELECTRIC SWITCH

Description

[0001] The invention is based on an electrical switch according to the preamble of patent claim 1.

[0002] Such an electrical switch, which can be operated like a rotary switch, can be used in electrical and household appliances such as washing machines, dishwashers, etc. For example, the switch in these devices serves as a power and / or program selector.

[0003] Such an electrical switch, designed as a rotary switch, has a rotatable actuating element. A locking mechanism interacts with the actuating element, allowing the actuating element to be rotated into locking positions. The locking mechanism consists of a locking wheel, in particular one with an approximately star-shaped design, and at least one locking element that exerts an elastic force and interacts with the locking wheel. Conventionally, the locking element consists of a compression spring and a ball and / or a sleeve that engages with the locking wheel. Such a locking mechanism therefore comprises a large number of individual parts that are expensive to manufacture and assemble. In addition, the locking element in the switch often has to be greased before being inserted, which incurs additional costs and permanently contaminates the assembly areas.

[0004] Printed prior art in the present technical field is contained in the documents US 5 589 671 A, US 3 196 237 A, DE 20 2008 002 959 U1,

[0005] DE 26 42 887 A1 and DE 10 2007 013 383 B3.

[0006] The invention is based on the object of further developing the electrical switch in such a way that the locking mechanism is simpler and more cost-effective.

[0007] This object is achieved in a generic electrical switch by the characterizing features of claim 1.

[0008] In the electrical switch according to the invention, the locking element consists of a spring frame, with at least one cam engaging the locking wheel being arranged on the spring frame. The spring frame advantageously achieves cost savings in material and / or assembly effort. Further embodiments of the invention are the subject of the dependent claims.

[0009] In a further embodiment, a housing can be provided for the electrical switch. The ratchet wheel can be arranged in a simple manner on a shaft operatively connected to the actuating element. The shaft can expediently be rotatably mounted in the housing. Furthermore, an electrical contact system can be located in the housing in the usual manner, wherein the contact system can be switched into switching positions corresponding to the ratchet positions by means of a switching cam arranged on the shaft.

[0010] To achieve a particularly good tactile feel when operating the switch, two cams, each engaging the ratchet wheel, can be arranged opposite each other on the spring frame. However, it may also be sufficient to arrange just a single cam on the spring frame.

[0011] A spring frame not according to the invention can be designed to be closed in a manner that is simple to manufacture. Furthermore, the spring frame can be mounted in a floating manner in the housing in a manner that is simple to assemble. The cam can expediently be integrated into the spring frame.

[0012] According to the invention, the spring frame is not designed to be closed. Furthermore, two webs are arranged on the spring frame, approximately perpendicular to the spring frame. These webs can also deflect laterally when the shaft rotates, so that forces occurring between the cam and the ratchet wheel are absorbed by the resilient webs. This effectively prevents the spring frame from twisting in an undefined manner.

[0013] The spring frame can be manufactured cost-effectively from plastic, particularly from a thermoplastic. The spring frame can expediently operate in the linear-elastic range of the material. Furthermore, it may also be advantageous for the housing to be made of plastic, particularly from a thermoplastic. In this case, the spring frame can be integrated into the housing in an even more cost-effective manner. The spring frame can be injected into the housing during production.

[0014] The following can be stated for a particularly preferred embodiment of the invention.

[0015] Haptic feedback is often required for rotary switches. This is usually achieved using a compression spring combined with a ball and / or sleeve that engages with some kind of gearing or a special cam. These systems are complex to assemble and, due to the number of individual parts and their materials and / or manufacturing, are usually expensive. Furthermore, this system often has to be "greased" before being installed in the switch, which incurs additional costs and permanently contaminates the assembly areas. This spring arrangement should be replaced with a more economical solution, especially for cost-sensitive applications.

[0016] In the invention, the locking mechanism is improved in that the spring assembly is replaced by a closed spring frame, preferably made of plastic. The spring operates in the linear-elastic range of the material. Furthermore, the cam contour, which engages the spring, is adapted to the friction pair of the spring. As a result, the achieved service life cycles are at least equivalent to those of the previous system.

[0017] It is also possible to integrate the spring frame directly into the housing using suitable tooling. This solution involves the spring exhibiting linear-elastic behavior not only in its preferred direction. Rather, it is designed so that the force derived from the cam movement can be absorbed by additional spring elements normal to the surface, preventing the spring from twisting in an undefined manner. In this case, this is achieved by an integrated spring with two webs perpendicular to the main spring, which can also deflect laterally. As with the spring frame, this creates a precise and / or reproducible haptic response for a given switching function.

[0018] This creates an improved locking mechanism, made in particular of plastic, for the rotary feel of an electrical switch.

[0019] The advantages achieved with the invention are, in particular, that an exact and / or reproducible haptic can be generated for the electrical switch for a given switching function. Due to the special shape of the spring frame, it is self-centering, in particular due to the floating bearing in the housing, which reduces the influence of individual part tolerances. Likewise, the optimized friction pairing between the cam on the spring frame and the ratchet wheel means that greasing is no longer necessary. With the same force and / or ratchet torque ratio, the previously used number of two spring sleeves is reduced to a single spring frame in the form of a plastic spring, which results in cost savings in material and / or assembly effort. The closed design of the spring frame makes it possible, depending on the switching task, to have just one or both cams in engagement with the switching shaft.In particular, the invention allows smaller switching angles to be achieved than before.

[0020] Embodiments of the invention with various developments and refinements are shown in the drawings and are described in more detail below. Fig. 1 shows an electrical switch not according to the invention in side view, Fig. 2 shows a section along the line 2-2 in Fig. 1 , Fig. 3 an exploded view of the non-inventive switch from Fig. 1 , Fig. 4a section as in Fig. 2 for a further version of the switch and Fig. 5 an exploded view as in Fig. 3 for the further design of the switch.

[0021] In Fig. 1 1 shows a closer look at an electrical switch 1 not according to the invention, designed as a rotary switch. The switch 1 has a housing 2 from which a shaft 3 protrudes. The shaft 3 interacts with a contact system located in the housing 2, not shown in detail, to switch the switch 1. An actuating element 4, which can be rotated by the user, is arranged on the shaft 3, so that the contact system can be switched into its switching positions by means of the actuating element 4.

[0022] How to continue in Fig. 2 As can be seen, a locking mechanism 5 interacts with the actuating member 4 in such a way that the actuating member 4 can be rotated into locking positions, wherein the locking positions correspond to the switching positions of the contact system. The locking mechanism 5 consists of a locking wheel 6, in particular of an approximately star-shaped design, and at least one locking element 7 which exerts an elastic force and interacts with the locking wheel 6. The locking element 7 in this case consists of a spring frame. At least one cam 8 which engages in the locking wheel 6 is arranged on the spring frame 7. In the Fig. 2 In the embodiment of the switch 1 shown, two cams 8, 8', each engaging in the ratchet wheel 6, are arranged opposite one another on the spring frame 7, so that the elastic ratchet force exerted by the spring frame 7 acts approximately symmetrically on the ratchet wheel 6.

[0023] As further in Fig. 3 As shown, the ratchet wheel 6 is arranged on the shaft 3, which is operatively connected to the actuating element 4. The shaft 3 is rotatably mounted in the housing 1. The contact system can be switched into switching positions corresponding to the ratchet positions by means of a switching cam 9 arranged on the shaft 3. Of course, several switching cams 9 for the contact system can also be located on the shaft 3. The spring frame 7 is designed to be closed and is mounted in a floating manner in the housing 2. The housing 2 finally consists of a base 2" and a cover 2'. The cover 2' can be latched to latching hooks 11 of the base 2" by means of tabs 10.

[0024] In Fig. 4 The switch 1 is shown according to a further embodiment, wherein the spring frame 7 is not designed to be closed. At least one web 12 is arranged on the spring frame 7, standing approximately perpendicular to the spring frame 7. The spring frame 7 is provided with two opposing webs 12, 12'. The webs 12, 12' are arranged in the housing 2 in such a way that they can also deflect laterally. Thus, the spring frame 7 not only exhibits linear-elastic behavior in a preferred direction, but rather the force resulting from the movement of the cam 8 normal to the surface of the spring frame 7 is absorbed by the additional resilient webs 12, 12'. This effectively prevents the spring frame 7 from twisting in an undefined manner. As further shown in Fig. 5 As can be seen, there are two

[0025] Ratchet wheels 6 are arranged, each of which interacts with a spring frame 7 as a locking mechanism 5.

[0026] The spring frame 7 is made of plastic, in particular a thermoplastic. The spring frame 7 is operated in the linear-elastic range of the material. The housing 2 can also be made of plastic, in particular a thermoplastic. Thus, the base 2", the cover 2', the spring frame 7, and also the shaft 3 with ratchet wheel 6 and switching cam 9 can be manufactured by injection molding. The cam 8, 8' can be integrated into the spring frame 7 by injection molding during the production of the spring frame 7. As already mentioned, the spring frame 7 is mounted in a floating manner in the housing 2.

[0027] In an embodiment not belonging to the invention, the spring frame 7 can also be integrated in the housing 2, in particular in the base 2", by injecting the spring frame 7 into the housing 2 by means of injection molding during the manufacture of the housing 2.

[0028] The invention is not limited to the described and illustrated embodiment. Rather, it also encompasses all developments within the scope of the invention defined by the patent claims. Thus, such an electrical switch 1 can be used not only as a rotary switch in household appliances, such as washing machines or dishwashers, but also in other electrical devices, such as power tools. Reference symbol list:

[0029] 1:(electrical) switch 2:housing (of switch) 2':cover (of housing) 2":base (of housing) 3:shaft 4:actuator 5:locking mechanism 6:ratchet wheel 7:ratcheting element / spring frame 8,8':cam (on spring frame) 9:switching cam 10:tab 11:ratchet hook 12,12':web (on spring frame)

Claims

1. An electrical switch, in particular a rotary switch, having a housing (2), a rotatable actuating member (4), with a detent (5) which interacts with the actuating member (4) in such a way that the actuating member (4) can be rotated in detent positions, the detent (5) comprising a detent wheel (6), in particular one having an approximately star-shaped design, and at least one detent member (7) which exerts an elastic force and interacts with the detent wheel (6), the detent member (7) consisting of a spring frame, and that at least one cam (8) engaging in the detent wheel (6) is arranged on the spring frame (7), the spring frame (7) having a non-closed design, and that two webs (12, 12') are arranged on the spring frame (7) approximately perpendicular to the spring frame (7), characterized in that the spring frame (7) is floatingly mounted in the housing (2).

2. The electrical switch according to claim 1, characterized in that the detent wheel (6) is arranged on a shaft (3) which is operatively connected to the actuating member (4), that the shaft (3) is preferably rotatably mounted in the housing (2), that an electrical contact system is also preferably located in the housing (2), the contact system being switchable in switching positions corresponding to the detent positions in particular by means of a switching cam (9) that is arranged on the shaft (3).

3. The electrical switch according to claim 1 or 2, characterized in that two cams (8, 8'), each engaging in the detent wheel (6), are arranged opposite one another on the spring frame (7).

4. The electrical switch according to any one of claims 1 to 3, characterized in that the spring frame (7) is made of plastic, in particular of a thermoplastic material, that the spring frame (7) is preferably operated in the linear-elastic range of the material, and that the cam (8, 8') is also preferably integrally formed in the spring frame (7).

5. The electrical switch according to any one of claims 1 to 4, characterized in that the housing (2) is made of plastic, in particular of a thermoplastic material.