Abstract
The disclosure relates to an electromagnetic switch, comprising: an armature; a slider configured to manually move to actuate the armature; and a deformable force transfer element positioned between the slider and the armature, wherein the slider is configured to be pressed against the deformable force transfer element to actuate the armature with a press force, and wherein the deformable force transfer element is configured to deform when a press force threshold value is exceeded to limit a transferable force from the slider onto the armature.
Claims
1. An electromagnetic switch, comprising: an armature; a slider configured to manually move to actuate the armature; and a deformable force transfer element positioned between the slider and the armature, wherein the slider is configured to be pressed against the deformable force transfer element to actuate the armature with a press force, and wherein the deformable force transfer element is configured to deform when a press force threshold value is exceeded to limit a transferable force from the slider onto the armature; wherein the deformable force transfer element comprises a deformable tongue, wherein the slider is configured to be pressed against the deformable tongue, and wherein the deformable tongue is configured to deform when the press force threshold value is exceeded to absorb the press force of the slider; wherein the deformable force transfer element is surrounded by a circumferential frame that is fixed to the armature, wherein a window is formed in the circumferential frame, and wherein the deformable tongue is mounted on one side on the circumferential frame and a deformation of the deformable force transfer element is absorbed at least partially by the window.
2. The electromagnetic switch according to claim 1, wherein the deformable force transfer element is connected to the armature.
3. The electromagnetic switch according to claim 1, wherein the deformable force transfer element is plastically or elastically deformed.
4. The electromagnetic switch according to claim 1, wherein the deformable tongue is formed by a partial surrounding slit from a piece of material, wherein the circumferential frame surrounds the partial surrounding slit, and wherein the deformable tongue is cut free from the piece of material by the partial surrounding slit and protrudes from a plane of the piece of material.
5. The electromagnetic switch according to claim 1, wherein the deformable tongue comprises a wave form, and wherein a wave flank of the deformable tongue is configured to be impinged by the slider.
6. The electromagnetic switch according to claim 1, wherein the press force threshold value is based at least in part on a geometrical form of the deformable tongue.
7. The electromagnetic switch according to claim 1, wherein the deformable force transfer element is configured to transfer the press force from the slider to the armature to actuate the armature when the press force does not exceed the press force threshold value.
8. The electromagnetic switch according to claim 1, further comprising: an electromechanical contact configured to freely release in a non-locked contact state, wherein the electromechanical contact is released by the armature by a releasing force applied by the slider on the deformable force transfer element, and wherein the press force threshold value is greater than the releasing force.
9. The electromagnetic switch according to claim 8, wherein the electromechanical contact in a locked state is not released by the releasing force, and wherein the deformable force transfer element is configured to prevent a release of the electromechanical contact in the locked state by using deformation.
10. The electromagnetic switch according to claim 9, wherein the deformable force transfer element is configured to prevent a plastic deformation of electromagnetic switch components by limiting a contact force to a contact force threshold.
11. The electromagnetic switch according to claim 1, wherein the deformable force transfer element is configured to prevent a break of the slider due to mechanical overload by using deformation.
12. The electromagnetic switch according to claim 1, wherein the deformable force transfer element is formed as a single piece.
13. The electromagnetic switch according to claim 1, wherein the electromagnetic switch is a relay.
14. The electromagnetic switch according to claim 1, further comprising a plurality of contacts configured such that opening a contact of the plurality of contacts causes another contact of the plurality of contacts to close.
15. The electromagnetic switch according to claim 2, wherein the deformable force transfer element is materially or frictionally connected to the armature.
16. The electromagnetic switch according to claim 9, wherein the locked state comprises an overcurrent-induced welding of the electromechanical contact in a closed position.
17. The electromagnetic switch according to claim 10, wherein the electromagnetic switch components comprise contact springs.
18. The electromagnetic switch according to claim 12, wherein the deformable force transfer element is formed from metal.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1) Examples of the present disclosure are described in the following with the help of the accompanying drawings.
(2) FIG. 1 shows an electromagnetic switch with non-actuated slider implemented as a relay;
(3) FIG. 2 shows the electromagnetic switch from FIG. 1 designed as a relay in fault-free condition with actuated slider;
(4) FIG. 3 shows the electromagnetic switch from FIG. 1 designed as a relay with actuated slider with welded normally closed contact;
(5) FIG. 4 shows a deformable force transfer element; and
(6) FIG. 5 shows the deformable force transfer element from FIG. 4 after a first manufacturing step.
DETAILED DESCRIPTION
(7) FIG. 1 shows a disclosure-related electromagnetic switch 100 that is realised as a relay. FIG. 1 shows the slider 101 with which the contacts 119, 123 of the relay can be manually actuated, in a non-actuated position. The normally open contact 119 is open here, while the normally closed contact 123 is closed. The normally open contact 119 can be closed manually by moving the slider 101 in the actuation direction 103, wherein the normally closed contact 123 is opened. In the example shown in FIG. 1, the normally open contact 119 and the normally closed contact 123 positively driven so that a closing of the normally open contact 119 always leads to an opening of the normally closed contact 123.
(8) In the non-actuated state of the slider 101, the tongue 107 of the deformable force transfer element 105 lies in a recess 111 in the slider 101 so that no forces are applied to the tongue 107 of the force transfer element 105 via slider 101. This also means that no forces are exerted on the armature 113 by the force transfer element 105 when the slider 101 is not actuated. Forces are therefore also not exercised on the contact spring 121 of the normally open contact by the armature in this condition so that the normally open contact 119 is open. A return spring 127 together with a magnetic restoring torque ensure that the armature 113 is always in a position in which the normally closed contact 123 is closed when no further electromagnetic or manual forces are exerted on the armature.
(9) In the example of the electromagnetic switch shown in FIG. 1, the deformable force transfer element is illustrated as force transfer element with a tongue 107 and a frame 109. The structure of this deformable force transfer element 105 is described below in more detail in the FIGS. 4 and 5.
(10) The deformable force transfer element 105 in FIG. 1 is fixed to the armature 113 using attachment elements 115. In the example of FIG. 1, the deformable force transfer element 105 is attached to the armature 113 using rivets. Other types of joints are however possible, for example bonding, welding or soldering.
(11) The armature 113 in the example of FIG. 1 is designed as a rocker armature. Other examples of an armature can however also be used, e.g. a hinged armature.
(12) In addition to a manual actuation via the slider 101, the electromagnetic switch 100 in the example of FIG. 1 can also be actuated electromagnetically in the known way. However, this should not be gone into further here.
(13) The manual actuation of the electromagnetic switch 100 as relay example from FIG. 1 occurs in that the slider 101 is moved by the operator in the actuation direction 103. This closes the normally open contact 119, while the normally closed contact 123 is opened. In FIG. 2, the electromagnetic switch implemented as relay is shown in a state in which the normally open contact 119 is closed, while the normally closed contact 123 is open. Also shown here, as in FIG. 1, is a fault-free condition, i.e. neither the normally open contact 119 nor the normally closed contact 123 are welded together.
(14) In the state shown in FIG. 2, the slider 101 is moved in the actuation direction 103 to close the normally open contact 119 and open the normally closed contact 123. Forces are applied to the tongue 107 of the deformable force transfer element 105 by a flank in the recess 111 of the slider 101, that can be transferred by the deformable force transfer element 105 to the armature 113. In the state shown in FIG. 2 in which the normally open contact 119 is closed, the slider 101 has not yet been brought to a mechanical end stop in the actuation direction 103. The slider 101 is however already so far moved in the actuation direction that the tongue 107 of the deformable force transfer element 105 has completely left the recess 111 of the slider 101.
(15) In the slider 101 position shown in FIG. 2, the force applied by the operator to the slider 101 is transferred to the armature 113 via the tongue 107. The armature 113 then transfers the force via intermediate elements to the contact spring 121 of the normally open contact 119, the said spring deforming elastically under the effect of the force and leading to a closing of the normally open contact 119. The normally closed contact 123 is opened simultaneously.
(16) As already described above, the deformable force transfer element 105 in the example shown has a tongue 107 via which the force exerted by the user on the slider 101 is transferred to the deformable force transfer element. The deformable force transfer element 105 also has a frame 109. Such an example of a deformable force transfer element 105 is described below in the explanations of FIGS. 4 and 5.
(17) In the state shown in FIG. 2, the frame 109 of the deformable force transfer element 105 lies on a protrusion 117 of the armature 113. The protrusion 117 limits the movement of the frame 109 of the deformable force transfer element 105 relative to the armature 113. On the other hand, the movement of the tongue 107 of the force transfer element 105 relative to the armature 113 is not limited. The tongue 107 and the frame 109 of the deformable transfer element 105 can therefore move relative to each other. In the state shown in FIG. 2 however there is no, or very slight, relative movement of the tongue 107 of the deformable force transfer element 105 relative to the frame 109.
(18) For the position of the slider 101 shown in FIG. 2, forces are applied on the one hand to the armature 113, which are transferred from the slider 101 via the tongue 107 of the force transfer element 105 onto the armature. These forces lead to closing of the normally open contact 119 and to opening of the normally closed contact 123. The return spring 127 deforms and exercises a restoring force on the armature 113 simultaneously due to the movement of the armature 113, which in turn leads to resetting of the armature 113 by moving the slider 101 against the actuation direction 103 and with that to an opening of the normally open contact 119 and to closing of the normally closed contact 123.
(19) FIG. 3 shows switch 100 of FIG. 1 implemented as a relay in a faulty condition. In the condition shown in FIG. 3, the normally closed contact 123 is welded, caused for example by overcurrents. This causes the normally open contact 119 to open and cannot be closed by electromagnetic actuation. The armature 113 is correspondingly located at a position that corresponds largely to the position of the non-actuated electromagnetic switch 100.
(20) In the condition shown in FIG. 3, the slider 101 has been moved in the actuation direction 103 by the operator till it has almost reached a mechanical stop, as it has attempted to actuate the faulty relay in order to close the normally open contact 119 and open the normally closed contact 123. In this state, there is a danger that the user exerts force on the slider 101 which results in the contact spring 125 of the normally closed contact being plastically deformed and permanently damaged if the user attempts to loosen the welded, normally closed contact. This would damage the relay and the positively driven operation between normally closed contact 123 and normally open contact 119 would be eliminated. This is prevented however by the disclosure-related example of the electromagnetic switch 100 due to the deformation of the deformable force transfer element 105.
(21) In the condition shown in FIG. 3, the movement of the frame 109 of the deformable force transfer element 105 relative to the armature 113, already explained with FIG. 2, is limited by the protrusion 117 of the armature 113. The movement of the frame 109 of the deformable force transfer element 105 relative to the armature 113 is therefore limited, regardless of how great the force exerted by the user on the slider 101 is. The force exerted by the user on the slider 101 leads however to the tongue 107 of the deformable force transfer element 105 moving relative to the frame 109 of the force transfer element 105. The tongue 107 moves relative to the armature 113 and then still further, when the movement of the frame 109 is already limited by the protrusion 117. The force transferred by the deformable force transfer element 105 on the armature 113 is limited by the relative movement or bending between frame 109 and tongue 107 of the deformable force transfer element 105. The force exerted here on the armature 113 via the tongue 107 and the frame 109 is determined by the relative bending between the tongue 107 and frame 109 as well as the spring constant. i.e. the elasticity at the joint between frame 109 and tongue 107. With increasing relative bending g between frame 109 and tongue 107 of the deformable force transfer element 105, the force exerted on the armature 113 via the tongue 107 and the frame 109 increases. It reaches its limit value when the slider 101 is so moved in the actuation direction that the tongue 107 contacts outside the recess 111, i.e. the tip of the tongue 107 contacts the underside of the slider 101 outside the recess 111 and the tongue 107 has so reached the state of its maximum bending relative to the further sections of the deformable force transfer element 105, especially relative to the frame 109. The maximum transferable force via the tongue 107 onto the armature 113 is therefore limited by the bending of the tongue 107 relative to the frame 109 and the bending of the tongue 107 relative to the armature 113 together with the elasticities, i.e. the spring constants of the connection between tongue 107 and frame 109 and between tongue 107 and the further sections of the deformable force transfer element 105. In the example of FIGS. 1 to 3, a movement of the slider 101 in the actuation direction 103 on the other hand does not lead to significant deformation of the tongue 107. The tongue 107 is only deformed in the section in which it has a connection to frame 109 and to the remaining section of the deformable force transfer element 105. There are however examples conceivable with which a deformation of the tongue 107 itself also takes place, for example a flattening of a triangular tongue, so that the deformation of the tongue 107 itself effects a limiting of the forces transferred via the tongue 107 to the armature 113. This can be achieved for example by reducing the stiffness of the tongue (107).
(22) The deformable force transfer element 105 is so designed in its geometry and elasticities that the maximum force transferred from slider 101 via the deformable force transfer element 105 to the armature 113 is smaller than the force that would lead to a plastic, i.e. permanent, deformation of the contact spring 125 of the normally closed contact 123. In other words, before a plastic deformation of the contact spring 125 of the normally closed contact 123 occurs, the forces that would be necessary for this are limited by an elastic deformation of the tongue 107 relative to the frame 109 of the deformable force transfer element 105. The deformable force transfer element 105 and especially its frame 109, is itself prestressed in the example shown in FIGS. 1 to 3 in that it has been bent. The pre-stressing also influences the press force threshold value and sets a defined value of the force limiting.
(23) In the example shown in FIGS. 1 to 3, the normally open contact 119 can be closed manually by actuating the slider 101. According to the disclosure, examples are however also possible in which the normally closed contact 123, instead of the normally open contact 119, can be opened by a manual actuation, or an opening and closing of a normally open contact as well as of a normally closed contact by manual actuation is possible. One or more sliders can be provided for this as well as several deformable force transfer elements arranged between sliders and armatures so that for example where only one slider in each slider direction takes effect against the flanks, one of two deformable force transfer elements positioned on an armature takes effect in each case.
(24) FIG. 4 shows a deformable force transfer element 105, as used in the example of the electromagnetic switch 100 according to FIGS. 1 to 3. The deformable force transfer element 105 shown here uses the leaf spring principle. In a rear section 405, the force transfer element 105 can be attached to the armature 113. Fixing holes 407 are provided for this in the example shown, for screwing or riveting the force transfer element 105 to the armature 113. It is however also possible to attach the force transfer element 105 to the armature 113 by bonding, soldering or welding.
(25) A tongue 107 is formed on the force transfer element 105, the former being surrounded by a frame 109. Frame 109 and tongue 107 are joined together at the transition in the rear section 405 of the force transfer element 105. The tongue 107 is so formed that it protrudes from the plane spanned by the force transfer element 105. The tongue in the installed condition thus protrudes in the direction of slider 101 so that when the slider 101 moves in the actuation direction 103 due to the slider 101, forces can be exerted on the flank of the tongue 107.
(26) A slit 401 is formed between frame 109 and tongue 107 that enables the movement of the tongue 107 relative to the frame 109. The slit 401 surrounds a window 409 in which the tongue 107 is positioned and in which the tongue 107 can move relative to frame 109 when forces are applied.
(27) The force transfer element 105 is folded in a front section 403, which reduces the window 409 for the movement of the tongue 107 so that the front section 501 of the tongue 107 (see FIG. 5) lies below the front section 403 of the force transfer element 105, which limits the movement of the tongue 107 relative to the frame 109 in the direction of the slider 101 when installed in the switch 100, i.e. the tongue with its front section 501 cannot move above the frame. This prevents the tongue 107 being able to move on the side of the frame 109 facing the slider 101.
(28) The deformable force transfer element 105 is internally prestressed, i.e. the section of the force transfer element 105 in which the tongue 107 and the frame 109 are arranged is prestressed or bent up in the direction of the slider, protruding from the plane of the section 405 in which the force transfer element 105 is fixed to the armature in the installed condition. The degree of prestressing here influences the amount of the force transferred from slider 101 to the armature 113 via the tongue 107 and the frame 109.
(29) FIG. 5 shows the deformable force transfer element 105 according to FIG. 4 following a first manufacturing step in which a slit 401 has been punched out from a single piece of material resulting in the formation of frame 109 and tongue 107. The tongue 107 has a front, widened section 501 that, as mentioned above, forms the movement of the tongue 107 in the direction of the slider, i.e. upwards limited, in that it forms a stop, that strikes against the front section 403 of the deformable force transfer element 105 when the front section 403 has been folded as shown in FIG. 4 and so that the section of the slit 401 or of window 409, facing the front section 501 of the tongue 107 is covered so that the tongue 107 there cannot move through the slit 401 or the window 409 that is formed by means of the slit 401 in the force transfer element 105.
(30) In the manufacturing step shown in FIG. 5, the holes 407 for attaching the force transfer element 105 to the armature are already made. In the further, subsequent manufacturing steps, the force transfer element 105 is still prestressed by the deforming of the frame 109, the tongue 107 is bent and the front section 403 is folded, as shown in FIG. 4, to form a limit for the movement of the tongue 107. The force transfer element 105, according to FIG. 4, is preferably made of metal, spring steel for example. However, it also can be manufactured from other materials with suitable elastic properties.
LIST OF REFERENCE NUMBERS
(31) 100 Electromagnetic switch 101 Slider 103 Actuation direction 105 Deformable force transfer element 107 Tongue 109 Frame 111 Recess 113 Armature 115 Attachment element 117 Protrusion 119 Normally open contact 121 Contact spring of the normally open contact 123 Normally closed contact 125 Contact spring of the normally closed contact 127 Return spring 401 Slit 403 Front section of the force transfer element 405 Rear section of the force transfer element 407 Attachment holes 409 Window 501 Front section of the tongue
