Step-by-step key switch

Abstract

The invention relates to a step-by-step key switch comprising a transmission unit having a first end and a second end opposite to the first end, an operating unit arranged at the first end, and an on-unit arranged at the second end and axially guided in a first guide portion, wherein the operating unit and / or the on-unit are configured to be axially movable relative to the transmission unit, wherein in a use condition an operating stroke relative to the first guide portion differs from an on-stroke relative to the first guide portion achieved by an intermediate transmission, wherein the ratio of the operating stroke to the on-stroke is greater than 1:1, in particular equal to 2:1, wherein the operating stroke is ≥ 2 mm.

Description

Technical Field

[0001] This invention relates to a step-by-step key switch (Stufenhubtaster) comprising a transmission unit, an operating unit, and an activation unit guided on a first guide portion, wherein the operating unit and / or the activation unit is configured to be axially movable relative to the transmission unit, particularly for use in vehicles and work equipment in the fields of construction and agricultural technology. Background Technology

[0002] Control of such equipment and vehicles is often achieved through a multi-function joystick and key switches (tasters) located on or beside it, used to select and control specific movements of the equipment or vehicle. Because operators are typically in noisy and vibrating environments, correctly and error-proofly operating these key switches, especially identifying the actions taken and successfully performed, becomes increasingly difficult. This very difficulty is fundamental to preventing errors during equipment and vehicle operation.

[0003] One possible solution for signaling successful operation is to use a long key switch travel, allowing the operator to receive clear tactile feedback even under vibration or through their gloves. However, a long travel requires increasing the structural space of the key switch. In typical applications, such space is often unavailable, and many key switches are mounted on control panels, making it impossible to enlarge the control panel by the same extent.

[0004] Furthermore, these key switches should be designed with ergonomics in mind to avoid large operational movements, which is not always feasible when the structural space is increased. Finally, a long operating stroke will also shorten the lifespan of the key switch because there are more / larger areas of wear and contamination. Summary of the Invention

[0005] Therefore, the purpose of this invention is to provide a step-by-step key switch with tactile feedback that can be operated safely and reliably.

[0006] This objective is achieved by a step-type key switch comprising: a transmission unit having a first end and a second end opposite to the first end; an operation unit disposed at the first end; and an axially guided turn-on unit disposed at the second end and in a first guide portion, wherein the operation unit and / or the turn-on unit is configured to be axially movable relative to the transmission unit, wherein the operation stroke occurring relative to the first guide portion in the operating condition is different from the turn-on stroke achieved by intermediate transmission relative to the first guide portion in the operating condition, wherein the ratio of the operation stroke to the turn-on stroke is greater than 1:1.

[0007] According to the invention, the operation and switching units are configured on the transmission unit as point contact, line contact, or surface contact. Since the contact plane is perpendicular to the axial lifting axis, line contact or surface contact advantageously reduces the influence of lateral forces. This allows for sliding with minimal loss between the operation unit, transmission unit, switching unit, and first guide portion. According to the invention, the transmission unit is constructed as a rigid unit, where the term "rigid" in the context of the invention means that the unit does not deform or only undergoes very small deformation when an operating force is applied to it. According to the invention, the operation unit transmits the operator's action to the switching unit via the transmission unit, which then opens or closes an electrical contact. It is particularly advantageous that the ratio between the operation stroke and the switching stroke is greater than 1. According to the invention, the stroke change is achieved through the initial idle stroke of the operation unit, during which the operation unit does not exert any action on the switching unit, which is in its stationary position. Only when the idle stroke is exceeded is the movement of the operation unit transmitted to the switching unit via the transmission unit, thereby producing the same and unidirectional movement of the operation unit and the switching unit. This provides the operator with sufficient tactile feedback without simultaneously affecting or altering the effective travel of the key switch.

[0008] A significant advantage is that this stroke length ratio allows for maintaining the structural dimensions previously used in key switches, without requiring adjustments to the external dimensions of the key switch itself due to the increased operating stroke. Another significant advantage is that, according to the invention, the operating unit, transmission unit, and activation unit are coaxially arranged, allowing the idle stroke of the operating unit to be accommodated within the structure of each corresponding unit. In this way, hinges or other components with radial motion assemblies are advantageously eliminated, thus minimizing motion transmission losses.

[0009] In the design of this invention, the ratio of operating travel to activation travel is specified to be between 1.0001:1 and 2:1, preferably 1.5:1, and particularly preferably equal to 2:1, and / or the operating travel is ≥1.5 mm, particularly ≥2 mm. These switching ratios or travel lengths represent the best trade-off between the smallest possible structural size of the step-type key switch and optimal operational reliability for the user. However, a ratio greater than 2:1 is also consistent with this invention, as are operating travels greater than or equal to 5 mm, up to 20 mm.

[0010] In the structural design of this invention, it is specified that the axial force applied by the operator to the operating unit during use is at least partially transmitted to the switching unit through the transmission unit. This structural design makes it possible to include a reset unit, the reset force of which is selected according to the invention in such a way that the operator can easily overcome the reset force to move the step-by-step key switch (button) axially to operate it. The typical axial operating force is between 2 and 10 N, and the reaction force of the reset unit is accordingly designed such that the total reaction force does not exceed 10 N. Similarly, according to the invention, the transmission unit itself is constructed as an elastic unit, particularly as a pressure spring unit. Depending on the selection of the elastic constant, the switching stroke is delayed and / or shortened compared to the operating stroke. According to the invention, the elastic constant is chosen to be so soft in this operating environment that the ratio of the operating stroke to the switching stroke is greater than 1:1; in particular, the elastic constant according to the invention is between 2,000 and 10,000 N / m.

[0011] In the design of this invention, it is specified that at least one first reset unit acts at least indirectly on the switching unit and the operating unit, and in particular, at least one second reset unit acts at least indirectly on the operating unit. It is highly advantageous that the first reset unit acts directly on the switching unit and indirectly on the operating unit, while the second reset unit acts directly on the operating unit. Since the operating stroke, which is larger than the switching stroke, cannot fully reset the operating unit by resetting the switching stroke, a second reset unit is provided, which moves the operating unit back to its initial position through an idle stroke.

[0012] According to the invention, a first reset unit is disposed between the first guide portion and the switching unit, and between the transmission unit and the housing. For this arrangement of the first reset unit, a rigid connection between the transmission unit and the switching unit is advantageous, as this allows the first reset unit to also reset the transmission unit. According to the invention, this rigid connection is achieved by bonding, brazing, or screwing. This rigid connection is also consistent with the invention when the first reset unit directly acts on the switching unit. According to the invention, a second reset unit is disposed between the operating unit and the housing, between the operating unit and the transmission unit, between the transmission unit and the switching unit, or between the transmission unit and the housing. Since the second reset unit acts at least indirectly on the operating unit, a loose connection exists between the unit where the second reset unit is disposed and the switching unit. Preferably, the first reset unit is advantageously constructed as a leaf spring, disposed below the switching unit (preferably a microswitch). This achieves high reliability of the components and avoids the need for an otherwise necessary operating unit, thus advantageously minimizing complexity and size. According to the present invention, the first and second reset units are configured as helical springs, electromechanical or electromagnetic actuators, or as pneumatic or hydraulic units.

[0013] In the structural design of this invention, the step-type key switch is specified to have a housing, wherein the housing preferably has first and second housing parts, wherein a first guide, a switching unit, a first reset unit, a transmission unit, and an operating unit are received in the first housing part, and a second reset unit is received in the second housing part. To reduce the complexity of the housing and thus lower manufacturing costs and save materials, the housing is advantageously designed to consist of multiple parts. According to the invention, the second and / or first housing parts are also configured to accommodate multiple side-by-side step-type key switches. It is advantageous to divide the housing into two parts, as this allows for the placement of seals on and between the housing parts and eliminates the need for additional fixing mechanisms.

[0014] In the design of this invention, the second reset unit is specified as an elastic plenum, particularly disposed between the operating unit and the housing, and preferably constructed as a pressure spring unit. This elastic plenum can be easily matched to the geometry of the operating unit and the housing, and it is preferably made of a rubber-based material, such as NBR (nitrile butadiene rubber), EPDM (ethylene propylene diene monomer rubber), or especially silicone rubber. With these materials, deformation results in a reset force that allows the plenum to return to its initial position.

[0015] Furthermore, the structural design of this invention specifies that the second reset unit is configured as a seal between the operating unit and the housing, specifically a labyrinth seal on the second housing component. Such a seal advantageously integrates two important functions into one unit: firstly, this configuration protects the components located within the housing cavity from contaminants, water intrusion, and other external environmental influences. Secondly, it improves the sealing performance of the switch or keypad, enabling the keypad switch of this invention to be cleaned without problems using a large volume of water at high speed, i.e., using a high-pressure jet / steam jet. According to the invention, the seal between the second reset unit and the housing has a protection rating of at least IP69K.

[0016] According to the invention, the first housing member has at least one first limiting stop for the transfer unit, and the transfer unit has at least one second limiting stop for the operating unit, wherein, in particular, the first limiting stop is configured as a radially fully encircling limiting stop. The first and second limiting stops advantageously restrict the movement of the operating unit or the transfer unit (generated by the reset unit). The greater the distance between the first and second limiting stops, the greater the axial travel length and idle distance that can move independently of each other.

[0017] In the development design of this invention, it is specified that: the first housing member has a second guide portion, wherein the transmission unit is guided by the second guide portion, and the transmission unit has a third guide portion, wherein the operating unit is guided by the third guide portion. According to the invention, the first and second guide portions are respectively formed by molding portions, particularly by vertically extending ribs, thereby advantageously reducing frictional losses due to line contact. According to the invention, shape and position tolerances are smaller in the guide region than in regions that do not affect guidance, to ensure reliable guidance and keep manufacturing costs as low as possible.

[0018] According to the present invention, the step-type key switch also has a display unit, wherein at least one of the operation unit or transmission unit is configured as a photoconductor unit. The display unit is configured as an LED according to the present invention and is continuously activated. LEDs are efficient, have a long lifespan, and are small in size. However, all types of light-emitting devices are suitable for the present invention. According to the present invention, the display unit and the switching unit are disposed on the same circuit board to avoid additional wiring that would otherwise be necessary. According to the present invention, materials such as completely transparent or translucent plastics and fiberglass are suitable as photoconductors. It is particularly advantageous that the photoconductor is constantly near the light source due to the idle travel, thus making the display unit particularly bright under the same light source illuminance. In other words, the distance between the photoconductor and the light source is no greater than or only slightly greater than the switching travel. Attached Figure Description

[0019] The invention will now be described in detail with reference to the accompanying drawings, using one embodiment, in which:

[0020] Figure 1 A first cross-sectional view of a step key switch in its initial position is shown.

[0021] Figure 2 A second cross-sectional view of a step key switch in its initial position is shown.

[0022] Figure 3 A first cross-sectional view of a step key switch in its intermediate position is shown.

[0023] Figure 4 A first cross-sectional view of a step key switch in the operating position is shown;

[0024] Figure 5 An exploded view of the operation unit 5, the transmission unit 2, and the first housing 11 is shown, with partial cross-section representation. Detailed Implementation

[0025] Figure 1A first cross-sectional view of the step key switch 1 in its initial position is shown, wherein the energizing unit (i.e., the "contact energizing unit") 7 is axially movably supported by a first guide portion 6 and is spaced apart from the circuit board 17. A first reset unit 8 is disposed between the energizing unit 7 and the circuit board 17. Furthermore, a transfer unit 2 is disposed above the energizing unit 7. The transfer unit 2 has a first end 3 and a second end 4, wherein the first end 3 is a polygonal hollow body, and the second end 4 is cylindrical. The shaped bodies of the first and second ends 3 and 4 are coaxially arranged with each other. The transfer unit 2 has a hollow frame 18 extending in the same direction as the second end 4, wherein the wall thickness of the frame 18 increases significantly, particularly at least doubles, in a portion region 19. This portion region 19 also has a large axial length; in particular, the length of this portion region 19 is at least 1.5 times the length of the frame 18 and is designed as an eccentric structure. The portion region 19 is spaced apart from the display unit 16 in the initial position. The display unit 16 is disposed adjacent to the first guide portion 6 on the circuit board 17. An operation unit 5 is disposed above the transmission unit 2. This operation unit also has a single-sided closed, polygonal hollow body. One open end face 22 of the operation unit 5 is designed to be parallel to a stop surface 23 perpendicular to the first end face 3, and is disposed at a distance from the stop surface. The first end face 3 is also disposed at a distance from an inner end face 24 of the operation unit 5. The first guide portion 6, the connection unit 7, the first reset unit 8, the transmission unit 2, and the operation unit 5 are at least partially housed in the first housing member 11. The first housing member 11 has a shape that particularly matches the external contours of the transmission unit 2 and the operation unit 5, wherein the side peripheral surface 25 of the frame 18 is configured to be spaced from the inner surface 26 of the housing member. The stop surface 23 contacts a first limiting stop 15, wherein the first limiting stop 15 is configured as a surface of the first housing member 11 extending parallel to the stop surface 23, and restricts the upward axial movement of the transmission unit 2. A tapered region 28 of the first housing member 11 is constructed above the first limiting stop 15, and the operating unit 5 is disposed within this tapered region 28. An edge 33 is constructed on the outer end face 32 of the operating unit 5, which is specifically made of elastic rubber. The first end of the second reset unit 9 is disposed between the operating unit 5 and the edge 33. The second reset unit 9 is also constructed of elastic material to form an elastic pleated 13. The second reset unit 9 is disposed between the first housing member 11 and the second housing member 12 at its second end opposite to the first end. Here, the second reset unit 9 is configured to wrap around the second housing member 12 in an L-shape and has a generally triangular rib 34 that contacts the upper side surface 27 of the housing member. The first and second housing members 11 and 12 constitute the housing 10 of the step key switch 1.Furthermore, the long side 29 of the "L" is specifically designed with multiple protrusions and grooves, which together create a labyrinth seal 14. The "L" design, the labyrinth seal 14, and the ribs 34 are all designed to reliably seal the internal housing cavity 35 from external intrusion.

[0026] Figure 2 A second cross-sectional view of the step key switch 1 in its initial position is shown, wherein the second cross-sectional view is oriented perpendicular to the first cross-sectional view. The transmission unit 2 has two opposing, mirror-image-shaped, ski jump-like components at its first end 3. The protruding head 20 has a second inclined surface 37 in the shape of a platform facing upwards. The protruding head 20 is configured as a second limiting stop 30 for the operating unit 5, wherein the two protruding heads 20 are respectively disposed in one of the two opposing openings 31 of the operating unit 5. The protruding head 20 contacts the operating unit 5 and restricts the upward axial movement of the operating unit 5. Furthermore, the first housing member 11 is constructed in a trapezoidal shape within the conical region 28. The open end face 22 has two converging inclined surfaces, wherein the first inclined surface 36 is configured to be parallel to the second inclined surface 37 of the protruding head 20.

[0027] Figure 3 A first cross-sectional view of the step key switch 1 in its intermediate position during operation is shown, wherein the operating unit 5 moves toward the transmission unit 2 by an axial force F, causing the stop surface 23 to contact the open end face 22. The first end 3 remains spaced from the inner end face 24. The axial movement of the operating unit 5 causes the second reset unit 9 to elastically deform and generate a second reaction force F opposite to the axial force F, acting directly on the operating unit 5. G2 .and Figure 1 Compared to the diagram in the figure, the transmission unit 2 and the connection unit 7 did not move, which constitutes a dead stroke for the operation unit 5.

[0028] Figure 4 A first cross-sectional view of the step-type key switch 1 in the operated position is shown, wherein an axial force F acts on the switching unit 7 via the operating unit 5 and the transmission unit 2, causing the switching unit to move in such a way that it indirectly contacts the circuit board 17, particularly via the first reset unit 8. The operating unit 5, the transmission unit 2, and the switching unit 7 move as if within the intermediate and operated positions of the step-type key switch 1. The elastic plenum 13 deforms to its maximum extent, thus possessing a maximum second reaction force F relative to the axial force F. G2 The first reset unit 8, constructed as a leaf spring, also has a maximum first reaction force F relative to the axial force F in this position. G1The distance between the partial area 19 and the display unit 16 is reduced compared to the initial or intermediate positions. In this embodiment, the transmission unit 2 is configured as a photoconductor unit that directs the light emitted from the display unit 16 to the operation unit 5. Due to the proportional relationship between the operating stroke and the connection stroke proposed in this invention, the distance between the display unit 16 and the partial area 19 is effectively shortened in all positions, allowing the emitted light to be received into the photoconductor unit over a very short distance, thus advantageously reducing losses, for example, caused by scattering. According to the invention, the operation unit 5 is made of a completely transparent or translucent material, thereby allowing the operator to identify the emitted light guided by the photoconductor unit through the operation unit 5. According to the invention, a label 38 is provided on the operation unit 5, which is opaque. During reset, between the operating position and the intermediate position, both the first and second reset units 8 and 9 act on the operation unit 5. Between the intermediate position and the initial position, only the second reset unit 9 acts on the operation unit 5 because the upward movement of the transmission unit 2 and the connection unit 7 is restricted by the first limit stop 15.

[0029] Figure 5An exploded view, partially cut away, is shown of the operating unit 5, the transmission unit 2, and the first housing 11. The first housing 11 has a second guide portion 39, which is constructed as a vertically extending rib. Two ribs are formed on each side of the inner surface 26 of the housing, and these ribs contact the frame 18 in the assembled position. The transmission unit 2 has a third guide portion 40, which is also constructed as a vertically extending rib. One rib is formed in each outer edge 41 of the transmission unit 2, and these ribs contact the inner peripheral surface 21 of the operating unit in the assembled position. The operating unit 5 is assembled into the first housing 11 from above, with the first and second inclined surfaces 36 and 37 facing each other before assembly. The operating unit 5 has two vertically extending through slots 43 in an opening region 42, thus creating the elasticity of the opposing opening regions 42. During assembly, the opening region 42 is pressed from above against the protrusion 20, wherein the first and second inclined surfaces 36, 37 are configured to contact each other and influence (control) the direction of the force in such a way that the resulting lateral force causes the opening region 42 of the operating unit 5 to deform reversibly outward, so that each protrusion 20 slides into an opening 31, and the opening region 42 subsequently returns to its initial position. The tapered region 28 is advantageously constructed to be partially trapezoidal in order to allow space for the reversible deformation of the opening region 42 during assembly. At the end of assembly, the axial movement freedom of the operating unit 5 is restricted by form locking, particularly by the hook connection with the transfer unit 2. Other reasons for this design of the first and second inclined surfaces 36, 37 are that this structural form approximates the force distribution / direction present in the region during loading, and achieves the draft angle required for reliable demolding of the molded part from the mold. The draft angle is particularly important for the production of molded parts using injection molding. The transfer unit 2 is assembled into the first housing part 11 from below.

[0030] List of reference numerals

[0031] 1. Stepped key switch

[0032] 2. Transfer Unit

[0033] 3 First end

[0034] 4 Second end

[0035] 5. Operation Unit

[0036] 6 First Guiding Section

[0037] 7 Connecting Unit

[0038] 8 First Reset Unit

[0039] 9 Second Reset Unit

[0040] 10. Shell

[0041] 11 First housing component

[0042] 12 Second housing component

[0043] 13. Elastic commissure

[0044] 14. Labyrinth seal

[0045] 15 First limit stop

[0046] 16 display units

[0047] 17 Circuit Boards

[0048] 18 Frames

[0049] 19 Partial Areas

[0050] 20 Convex head

[0051] 21. Inner circumferential surface of the operating unit

[0052] 22 Open end face

[0053] 23 Stop surface

[0054] 24 Internal end face

[0055] 25 Side circumferential surface

[0056] 26. Inner surface of housing component

[0057] 27. Upper side of housing component

[0058] 28 Conical region

[0059] 29 Long side

[0060] 30 Second limit stop

[0061] 31 Opening

[0062] 32 External end face

[0063] 33 Edge

[0064] 34 ribs

[0065] 35. Shell cavity

[0066] 36 First inclined plane

[0067] 37 second slope

[0068] 38 tags

[0069] 39 Second Guide Section

[0070] 40 Third Guiding Section

[0071] 41 Outer edge

[0072] 42 Opening area

[0073] 43 Through slot

[0074] F G1 first reaction force

[0075] F G2 second reaction force

[0076] F Axial force

Claims

1. A step-type key switch (1), comprising: The transmission unit (2) has a first end (3) and a second end (4) opposite to the first end. An operating unit (5) is provided at the first end (3); and a switching unit (7) is provided at the second end (4) and axially guided in the first guide (6), wherein the operating unit (5) and / or the switching unit (7) are configured to move axially relative to the transmission unit (2), characterized in that the operating stroke occurring relative to the first guide (6) in the use condition is different from the switching stroke occurring relative to the first guide in the use condition and achieved through intermediate transmission, wherein the ratio of the operating stroke to the switching stroke is greater than 1:1; and at least one first reset unit (8) acts at least indirectly on the switching unit (7) and the operating unit (5), and at least one second reset unit (9) acts at least indirectly on the operating unit (5).

2. The step-type key switch (1) according to claim 1, characterized in that, The ratio of the operating stroke to the connection stroke is between 1.0001:1 and 2:1; and / or, the operating stroke is ≥ 1.5mm.

3. The step-type key switch (1) according to claim 2, characterized in that, The ratio of the operating stroke to the connection stroke is 1.5:

1.

4. The step-type key switch (1) according to claim 2, characterized in that, The ratio of the operating stroke to the connection stroke is 2:

1.

5. The step-type key switch (1) according to claim 2, characterized in that, The operating stroke is ≥ 2mm.

6. The step-type key switch (1) according to claim 1, characterized in that, The axial force (F) applied by the operator to the operating unit (5) during operation is at least partially transmitted to the switching unit (7) through the transmission unit (2).

7. The step-type key switch (1) according to any one of claims 1 to 6, characterized in that, The step key switch has a housing (10), wherein the housing (10) has a first housing part (11) and a second housing part (12), wherein a first guide part (6), a switching unit (7), a first reset unit (8), a transmission unit (2) and an operation unit (5) are received in the first housing part (11), and a second reset unit (9) is received in the second housing part (12).

8. The step-type key switch (1) according to claim 7, characterized in that, The second reset unit (9) is constructed as an elastic fold (13), which is disposed between the operating unit (5) and the housing (10), wherein the elastic fold (13) is constructed as a pressure spring unit.

9. The step-type key switch (1) according to claim 7, characterized in that, The second reset unit (9) is configured as a seal between the operating unit (5) and the housing (10).

10. The step-type key switch (1) according to claim 9, characterized in that, The second reset unit (9) is configured as a labyrinth seal (14) disposed on the second housing part (12).

11. The step-type key switch (1) according to claim 7, characterized in that, The first housing component (11) has at least one first limiting stop (15) for the transfer unit (2), and the transfer unit (2) has at least one second limiting stop (30) for the operation unit (5).

12. The step-type key switch (1) according to claim 11, characterized in that, The first limiting stop (15) is constructed as a radially completely enclosed limiting stop.

13. The step-type key switch (1) according to claim 7, characterized in that, The first housing part (11) has a second guide (39), wherein the transfer unit (2) is guided by the second guide (39), and the transfer unit (2) has a third guide (40), wherein the operation unit (5) is guided by the third guide (40).

14. The step-type key switch (1) according to any one of claims 1 to 6, characterized in that, The step key switch includes a display unit (16), wherein at least one of the operation unit (5) or the transmission unit (2) is configured as a photoconductor unit, wherein the maximum distance between the photoconductor unit and the light source is only slightly greater than the turn-on stroke.

15. The step-type key switch (1) according to claim 7, characterized in that, The step key switch includes a display unit (16), wherein at least one of the operation unit (5) or the transmission unit (2) is configured as a photoconductor unit, wherein the maximum distance between the photoconductor unit and the light source is only slightly greater than the turn-on stroke.

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