Patent Application
20240321528
The present invention relates to a snap-action switching element described herein.
A number of snap-action switching elements are known from the prior art. DE 43 16 068 A1 uses a one-piece round wire as a snap-action switching element, which can be transferred from one switching position to the other switching position via an actuating element guided in the housing of the snap-action switch, whereby this switching position is held.
Another snap-action switching element is known from EP 3 312 861 A1, in which the actuating element engages in a spring with which a rocker switch is actuated. A return spring provided inside the actuating element returns the actuating element to its starting position.
DE 43 03 589 A1 discloses a cascaded snap-action switching element with normally closed or normally open contact with a bistable behavior with two spring-actuated rockers connected in series, whereby the first spring is pressed through as an actuating spring by pressing down the actuating element, whereby an actuating rocker is then pivoted, with which the second stage is then triggered.
JP2008047317A shows a snap-action switching element with the features described herein.
A similar system is known from the JPS60134245U, in which the plunger as actuating element presses directly on an L-shaped actuating rocker, which acts on a rocker switch via a spring and switches the movable contact between two fixed contacts.
CN207542118U discloses a microswitch with forced disconnection. A button triggers an elastic element and a movable contact piece. After the switch has reached the switching position, the release is forced, whereby a separating piece ensures the separation of the normally closed contact from the movable contact.
U.S. Pat. No. 2,509,194 A shows a changeover switch with a stop for the actuating rocker formed by a screw-in screw.
The snap-action switching elements of the state of the art have the disadvantage that the user does not have an optimum haptic switching experience. In most cases, annoying bouncing of the switch contact cannot be ruled out. An automatic, safe release of the switch back into the rest position once it has been brought into the switching position can usually only be reliably achieved using complex designs and additional elements.
Based on this state of the art, the invention is based on the task of providing an improved snap-action switching element with normally closed or normally open contact, which eliminates the disadvantages of the prior art.
A snap-action switching element with normally closed or normally open contact according to the invention comprises a housing, a first and a second contact point fixed to the housing, a contact arm movable between a rest position and a switching position, and an actuating member guided in the housing, with which the contact arm is movable between the rest position and the switching position. A rocker switch is arranged at one end so that it can be rotated about a rocker pivot axis extending transversely to the longitudinal axis of the housing, with a tension spring being hooked onto a spring hook-in section at the other free end of the rocker switch. The actuating member is guided perpendicular to the longitudinal axis of the housing and engages with the rocker switch between the two ends. The second contact point fixed to the housing represents a contact arm axis of rotation parallel to the rocker axis of rotation, against which one free end of the contact arm is pressed by the tension spring suspended in the contact arm, whereby the other end of the contact arm makes contact with the first contact point in the rest position in the case of a normally closed contact and is arranged at a distance from the first contact point in the rest position in the case of a normally open contact. The actuating member has a rocker bearing opening which is provided transversely to its direction of movement, in which a rocker bearing actuating section provided transversely to a main plane of the rocker switch engages, which allows a compact design of the rocker switch and actuating element next to each other in the housing. Side by side means that the pivoting movement of the rocker switch is achieved via an essentially horizontally aligned rocker bearing actuating section, the longitudinal axis of which is perpendicular to the main axis of the actuating element.
In a preferred embodiment, the rocker switch has a driver which, in the rest position, projects from below over the contact arm in such a way that, when the rocker switch is moved into its switching position, it engages with the contact arm from above before the switching position is reached, in particular at the switch actuating position, and swivels it downwards in an actively guided manner in the event that the contact arm does not move between the rest position of the actuating member and the engagement by adhesion of the contact point of the contact arm to the first contact point.
The length of the tension spring, the distance between the hook-in opening in the contact arm and the contact arm axis of rotation, and the distance between the spring hook-in section and the rocker axis of rotation are advantageously predetermined so that the torque acting on the rocker switch is always directed upwards in the rest position, in the switching position and in the positions in between of the actuating element, so that the actuating member moves back to the rest position without being actuated.
These above-mentioned features can be realized with a normally closed switching element as well as with a normally open switching element. In both cases, the linear movement of the actuating shaft is transmitted approximately centrally to the rocker switch between its ends. These are sometimes also referred to as free ends, even if they are mounted.
The function of the normally closed (NC) switching element in particular is ensured if the rocker switch has a driver. This driver can comprise at least one horn, preferably two horns to the left and right of the contact arm. A continuous bar or bridge can also be provided so that the contact arm protrudes through the passage formed by the bar. This contour then protrudes from below over the contact arm in the rest position in such a way that it can engage with the contact arm from above when the rocker switch is moved into the switching position before this switching position is reached, in particular already when or shortly after the switching position is reached, and can pivot it downwards in an actively guided manner if the contact arm does not move between the rest position of the actuating element and the engagement due to the contact point of the contact arm adhering to the first contact point. This ensures the switching in all cases and functionally means a forced disconnection.
The rocker bearing actuating section can therefore be a transversely arranged bolt which is inserted in a corresponding receptacle of the rocker switch. It can also be a rocker bearing actuating section integrally connected to the rocker switch, which engages with the actuating member via a rocker bearing opening, in particular through a substantially horizontally aligned slot with two opposing parallel central areas in the actuating member. The bolt can be cylindrical but can also be connected in one piece with either the rocker or the plunger or be in a form fit with them. There must be sufficient play in the complementary element to combine the vertical movement of the plunger with the pivoting movement of the rocker.
An upper rest position stop can then be provided between the rocker bearing actuating section and the spring catch section. And/or a support section for the contact arm can be provided between the rocker pivot axis and the rocker bearing actuating section, in particular against which the underside of the contact arm leans once the switching position has been exceeded, thereby preventing mechanical bouncing against the stop.
Starting from the free end with the contact arm's axis of rotation, the contact arm can have a rocker switch mounting opening and a separate spring end mounting opening adjoining it. Such a central articulation to the contact arm avoids undesirable lateral forces.
The contact arm can then advantageously have a U-shaped cross-section in the longitudinal direction, at least in the area of the rocker switch mounting opening and the spring end mounting opening, so that it is torsionally rigid and only rotates around the axle groove.
The rocker switch can have a receiving opening and a rocker bearing actuating section inserted into this receiving opening, with which the actuating member engages with the rocker switch between the two ends of the rocker switch.
The rocker switch can also have two transverse upper and lower mounting openings. In this case, the rocker switch actuating section is a bolt or cylinder inserted into one of the openings, for example the upper opening. This has particular advantages when a double switching element is provided, whereby as many components as possible should be standardized. In this case, the other, in this case lower, mounting opening optionally already has a partition in the middle. This design forms a laterally designed double switching element.
Such a double-jump switching element is based on a single-jump switching element in which the side wall of the housing has a substantially vertically aligned housing groove in the area of the lower mounting opening of the rocker switch in the side wall, so that a connecting shaft is inserted into the other, in this case lower, mounting opening. The aforementioned partition wall is then advantageous, as the connecting shaft cannot move transversely. Then a further pair of housing-fixed contact points, a further contact arm, a further rocker switch and a further tension spring are provided in a housing attachment, each of which is arranged in the direction of the longitudinal axis of the housing parallel to the first housing-fixed contact points, the first contact arm, the first rocker switch and the first tension spring behind the said side wall, the movement of the two rocker switches being synchronized by the connecting shaft. Only one actuating element is therefore required for the safe actuation of two separate switching circuits.
It can also be a single receiving opening and the connecting shaft can then either be integrated in one piece into the rocker bearing actuating section or the rocker bearing actuating section and connecting shaft are arranged one behind the other in the single receiving opening as seen from the side of the actuating member.
Further embodiments are given in the dependent claims.
The terms Fig., Figs., Figure, and Figures are used interchangeably in the specification to refer to the corresponding figures in the drawings.
Preferred embodiments of the invention are described below with reference to the drawings, which are for explanatory purposes only and are not to be construed restrictively. The drawings show:
The housing 10 has an upper housing opening 11 at the top and another lower housing opening 11′ at the bottom. The openings 11 and 11′ are located one above the other and define an actuating axis along which the actuating member 20 can be moved as an actuating shaft in the longitudinal direction of this axis. The actuating shaft 20 has an upper head section 23 and a lower guided section 24 between which a rocker bearing opening 22 is located. The rocker bearing opening 22 is in particular an aperture in the form of a substantially horizontally aligned slot in the actuating member 20. The horizontal alignment of the slot takes account of the slight transverse pivoting movement of the rocker switch 30 during its movement. Instead of such an elongated hole, the rocker bearing opening 22 can also have a different shape that allows horizontal play for the movement of the rocker bearing actuating section 33. The rocker bearing opening 22 may have a vertical height to allow movement of the rocker bearing operating portion 33 toward the operating member 20 during the shifting operation. The upper head portion 23 has an actuating head that is T-shaped in plan view. The T-shaped flanks are widened and chamfered in the direction of the actuating axis. The housing 10 has guide ribs for the actuating element 20, which are not shown in
A first conductive contact 41 is arranged in the housing 10. The contact 41 is a multi-bent flat metal component, which essentially has a C-shape in the side view. One free end of the first contact 41 is accessible from outside the housing 10 and is protected between two housing side wall sections 13 in the embodiment shown in
A second conductive contact 42 is arranged in the longitudinal direction of the housing 10 on the opposite side of the actuating element 20. Here too, a free end of the second contact 42 can be connected to an external cable using clamping plate 51 and screw 52. The second conductive contact 42 is also inserted in the housing 10 near the inner wall of the housing in an approximate C-shape with contact support ribs 15 and counter-ribs 16. However, it has a bearing groove 62 in the upper area at its opposite second free end in the side view. The orientation of the bearing groove 62 is horizontal with respect to the vertically oriented actuating member 20. In other words, the bearing groove 62 is oriented transversely or transversely with respect to the longitudinal direction of the housing 10.
The switching connection between the first conductive contact 41 and the second conductive contact 42 is established with the mounted contact arm 43. Like the first-mentioned contacts 41 and 42, the contact arm 43 is a metal component which, however, has some further features. The end projecting into the bearing groove 62 can have a taper and in particular be rounded. Preferably, this end projecting into the bearing groove 62 is held laterally against transverse displacement by ribs 16 of the housing 10. Adjacent to the end of the contact arm 43 projecting into the bearing groove 62 is a rocker receiving opening 45, which is adjoined by a separate spring receiving opening 44. The contact point 63 of the mounted contact arm 43 is provided at the opposite free end, which can be designed in particular as a contact bead inserted into a further opening.
The length of the contact arm 43 in the housing is selected in such a way that the contact point 63 can be brought into conductive contact with the first contact point 61 when one free end engages in the bearing groove 62. In this rest position shown in
When viewed in the longitudinal direction of the contact arm 43, it is advantageously U-shaped in the areas with the openings 44 and 45, for example having lateral wings in the original shape, which are then folded into this U-shape in order to reinforce the structure of the contact arm 43.
A transverse rocker switch bearing 12 is provided in the housing 10, which protrudes from the side wall and on which a rocker switch 30 is placed with its bearing opening 31. For short switching distances, the rocker bearing actuating section 33 on the rocker switch 30 is advantageously provided at approximately the same height as the rocker switch bearing 12. The rocker bearing actuating section 33 is a transversely aligned pin, in particular a cylindrical section, in short a cylindrical pin, which is inserted into the rocker bearing opening 22 of the actuating member 20.
This divides the rocker switch 30 into two sections, namely the bearing-side section 35 located between the rocker switch bearing 12 and the actuating section 33 and the spring-side section 36 located on the other side. Two laterally raised horns 32 are provided on the bearing-side section 35, which rise above the contact arm 43 to the left and right of the latter and, as can be seen in
The spring-side section 36 has a spring-engaging section 34, in particular a short transverse shaft with a circumferential groove for receiving a spring end. The spring-side section 36 can also have a stop which, in the rest position, strikes against the inner wall of the housing 10 from below. The spring hook-in section 34 is narrow enough in the transverse direction to be able to pass through the rocker receiving opening 45; the aforementioned optional stop can, like the horns 32, be guided next to the contact arm 43 or also through the opening 45.
A tension spring 70 is suspended with its one free end on the spring suspension section 34 and with its other free end in the spring receiving opening 44 of the contact arm 43, so that with its spring force it pulls the contact arm 43 with its free end designed as a bearing into the bearing groove 62 and holds it in this groove. As can be seen in
This description thus leads to the sequence of the switching operation, in which the actuating element 20 is pressed down in the rest position of
When the actuating member 20 is pressed down further in the direction of the switching position according to
The stroke to be triggered by the actuating element 20 for this movement is less than 0.3 millimeters for standard sizes of the snap-action switching element 100. This application of force also prevents bouncing. If the contact points 61 and 63 have stuck together, the horns 32 come into contact with the contact arm 42 from above during the downward movement of the rocker switch 30 and pull it downwards in a forced separation, whereby any sticking together of the contact points 61 and 63 is reliably released.
In the end position shown in
The housing half 10 shown on the left in
In the description of
The upper receiving opening 38 has a shoulder narrowing the inner diameter as a stop for the rocker bearing actuating section 33. This can also be replaced by a partition wall, as in the lower receiving opening 138, and conversely the partition wall can be replaced by corresponding oppositely aligned shoulders narrowing the inner diameter. In other embodiments, the arrangement of top and bottom can be reversed accordingly, so that the connecting shaft is inserted in an upper receiving opening 38 and the substantially vertically aligned housing groove 17 is correspondingly designed further up or simply larger. In the case of the embodiment example of the snap-action switching element 200, the connecting shaft 133 projects through the said housing groove 17 of the housing 10 into the lower receiving opening 138 of the rocker switch 130, which is constructed identically to the rocker switch 30. Advantageously, the lower receiving opening 138 is optionally divided into two blind holes by a centrally arranged wall, so that the inserted connecting shaft 133 cannot move transversely. In the case of the rocker switch 130, the upper receiving opening 38 remains empty, because the switching operation is carried out by the single actuating member 20 via the rocker bearing actuating section 33. The identical structure around the rocker switches 30 or 130 results in an identically mounted switching operation, since the springs 70 are suspended in an identical position between the contact arms 43 or 143 and the spring suspension sections 34 of the rocker switches 30 or 130, so that the contact arms 43, 143 are arranged in the bearing grooves 62 of the second contacts 42, 142.
The fully extended line 310 represents the force acting on the rocker switch 30, as it acts on the rocker switch 30, for example, at the spring catch section 34 or at the rocker bearing actuating section 33, i.e. the transversely inserted cylindrical pin. It should be noted that this force always acts in one direction, whereby the positive value shown here corresponds to a force in the direction of the rest position of the actuating shaft 20.
The roughly dashed curve 320 represents the progression of the force acting on the contact point 63 of the mounted contact arm 43.
The fine dashed curve 330 represents a path, namely the distance of the supported contact point 63 from the associated fixed contact point 61.
In the rest position of the actuating shaft 20, a holding force 311 acts on it and holds the actuating shaft 20 in this rest position. Parallel to this, an initial force 321 acts on the contact point 63 of the mounted contact arm 43 and holds it at the fixed contact point 61 assigned to it. This means that it is securely closed. Therefore, the distance 331 between contact point 63 of the supported contact arm 43 and the fixed contact point 61 assigned to it is zero (=0).
When the actuating shaft 20 is actuated, the force acting on the actuating shaft 20 in the opposite direction to its movement increases up to the relative peak value 312 at the start of the opening movement of the switching element. This point is characterized by reaching the value of the force 322 equal to zero (=0), i.e. when no more force acts on the contact point 63 of the mounted contact arm 43 and pulls it to the fixed contact point 61. From this point onwards, the distance between contact point 63 of the mounted contact arm 43 and the fixed contact point 61 assigned to it changes rapidly from zero to an opening value 332 when the rocker switch 30 switches; parallel to this, the force acting on the actuating shaft 20 in the opposite direction to its actuation decreases to a minimum value 313, which corresponds to the force at the end of the opening movement of the switching element.
When the actuating shaft 20 is pressed down further, the restoring force 314 acting on the rocker switch increases again monotonically. At the same time, the distance 334 of the contact point 63 continues to increase until the free end of the contact arm 43 eventually comes into contact with the contact surface 37.
The snap-action switching element 400 is shown in the position in which the actuating shaft 20 (not shown) is in the rest position. However, it is shown indirectly in relation to its height position by the rocker bearing actuating section 33, since this cylindrical pin is arranged in the slotted hole 22 of the actuating shaft 20.
The kinematic reversal of the function between the embodiment examples shown in
The housing half 10 shown on the left in
In all embodiments, a lower housing opening 11′ is provided, which has side walls 111′ in which the actuating section 20 is guided as a plunger. In this case, the underside 120 of the actuating section or actuating shaft 20 ends in the rest position of the actuating shaft 20 between the side walls 111′ of the lower housing opening 11′. Parallel to this, the upper side 110 of the housing 10 is then designed to complement the lower side 110′ of the housing 10, which makes it possible to provide a vertically arranged double snap-action switching element by arranging two versions of the snap-action switching elements 100, 200, 400, 500 one above the other.
| Number | Date | Country | Kind |
|---|---|---|---|
| CH0702732021 | Sep 2021 | CH | national |
This application is the United States national phase of International Patent Application No. PCT/EP2022/075268 filed Sep. 12, 2022, and claims priority to Swiss Application No. CH070273/2021 filed Sep. 15, 2021, the disclosures of which are hereby incorporated by reference in their entireties.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2022/075268 | 9/12/2022 | WO |
