DESCRIPTION

Pneumatic Control Unit

The present invention relates to a pneumatic control unit, a component of a pneumatic vehicle brake and/or air suspension system and such a system.

Pneumatic systems especially installed on trailer vehicles are used for realizing several functions of the trailer. One function is the raising and lowering of the vehicle body of the trailer to adjust its height with respect to, for example, a loading bay. These systems can be controlled by manually operated actuators. To avoid that an operator has to hold the actuator in a position causing e.g. raising of the trailer, there is a need for an actuator which can be locked in at least one position.

In some situations e.g. when the trailer is moved away from the loading bay, the pneumatic system has to execute a reset so that the height of the trailer is adjusted to a predetermined height level. If the system comprises actuators for the raising and lowering operation which can be locked or which remain in an operating position, the reset of these actuators has to be done manually. Thus, there is a need for self resetting actuators.

It is an object of the present invention to provide a possibility for locking an actuator of a system as described above.

This object is solved by the subject matters of the independent patent claims.

Advantageous embodiments are given by the subject matters of the dependent claims.

According to the invention, a pneumatic control unit is provided for controlling a pneumatic pressure comprising:

- a housing,

- at least one actuator configured to be, especially manually, moved along a total distance within the housing and configured to control a pneumatic pressure depending on its position on the total distance, and - a locking mechanism configured to lock the at least one actuator in at least one locking position along the total distance.

The housing is preferably comprising at least one output port preferably configured to supply the pneumatic pressure controlled by the at least one actuator to other devices which are connected to the at least one output port.

The pneumatic control unit is preferably comprising at least one supply port configured to receive a pneumatic pressure.

The pneumatic control unit is preferably comprising an exhaust port configured to exhaust the output port which is configured to supply the pneumatic pressure.

Preferably, the pneumatic control unit is configured that controlling operation of the pneumatic pressure comprises supplying the pneumatic pressure from the supply port to the output port in at least one position of the actuator along the total distance and connecting the output port to the exhaust port in order to exhaust the output port in at least another position of the actuator along the total distance.

The locking mechanism allows an operator to move the actuator into the locking position, wherein the actuator is preferably configured to supply the pneumatic pressure to the output port of the pneumatic control unit.

The at least one locking position is preferably an end position on the total distance. Additionally or alternatively, the locking mechanism is configured to release the locking of the at least one actuator if at least one release condition is met.

Preferably, the pneumatic control unit comprises an operating element configured to be manually moved along a second total distance into at least one position along the second total distance and configured, when the operating element is in an operating position, to transmit its manual movement to the at least one actuator to cause the manual movement of the at least one actuator along the total distance into a

predetermined position, especially the locking position along the total distance. The operating position of the operating element is preferably a position wherein the operating element can transmit its movement along the second total distance to the at least one actuator.

If the operating element is configured to be moved along a straight line, the distance covered by the movement of the operating element defines the second total distance. If the operating element is configured to rotate around an axis, the angle range which the operating element covers defines the second total distance.

The operating element is preferably provided rotatable, in particular around an axis extending in parallel to the total distance.

The operating element is preferably configured to transmit its movement to several actuators depending on the position of the operating element along the second total distance. For example, when the operating element is moved to a first position along the second total distance, it transmits its movement to at least one first actuator, wherein when the operating element is moved to a second position along the second total distance, it transmits its movement to at least one second actuator.

Preferably between the operating element and the at least one actuator a transmission means is provided configured to transmit the movement of the operating element onto the at least one actuator. The transmission means can be configured to transmit the movement of the operating element by a ratio of 1 : 1 onto the at least one actuator or by another ratio. For example, a movement of the operating element can cause a smaller movement of the at least one actuator or vice versa. The transmission means can further be configured to transmit a rotational movement into a translational movement or vice versa.

Preferably, the transmission means comprises at least one transmission surface and at least one transmission counterpart, preferably comprising a second transmission surface, which are configured, while abutting to each other, to transmit the movement of the operating element onto the at least one actuator. The transmission surface is preferably provided on a cam and/or the transmission counterpart is preferably comprising a cam. For example, the transmission surface is provided on the operating element and the transmission counterpart is provided on the at least one actuator or vice versa. As mentioned above, the operating element can be configured to be moved translationally or rotationally along the second total distance. The transmission surface and the transmission counterpart are configured to slide against each other, whereby the movement of the operating element is transmitted to the at least one actuator.

Preferably, the transmission surface and/or the transmission counterpart comprise a slope whereby the movement of the operating element which is not oriented in parallel to the total distance, can be transmitted into a translational movement of the at least one actuator along the total distance. In particular, both transmission surfaces correspond to a kind of a cam pair whereby the rotation of the operating element is transformed in a translational movement of the at least one actuator. Preferably, the transmission surface or the transmission counterpart preferably comprise a rolling element, especially a ball, to unroll on the transmission surface or on the transmission counterpart. Thereby friction between the transmission surface and the transmission counterpart can be reduced.

Preferably, the operating element comprising the transmission surface which is abutting on the transmission counterpart provided on the at least one actuator or vice versa.

Preferably, the locking mechanism comprises two locking parts configured to lock the operating element in the at least one position on the second total distance when interacting, in particular engaging, with each other. Preferably, the locking mechanism is configured to release the locking of the operating element on the second total distance when the operating element is moved, especially in parallel to the total distance, into a release position wherein the locking parts are to be released from each other. The release position is preferably a position of the operating element wherein the operating element has a bigger distance to the housing compared with the operating position of the operating element. If the operating element is a rotating element, the release position of the operating element can be reached by moving the operating element away from the housing along its rotational axis. Preferably, when the operating element is in its release position, the at least one release condition to unlock the at least one actuator is met. Preferably, the locking parts comprise a protrusion and a corresponding protrusion or pocket so as to form a releasable connection, in particular a snap-fit connection, and/or the locking parts are configured to attract themselves magnetically.

Preferably, the locking of the operating element by the locking mechanism can be overcome by an operator, who applies a force or torque on the operating element to move it along the second total distance against the locking force of the locking mechanism. Therefore, the locking parts which are engaging with each other to generate the locking force are preferably elastically deformable if they are pressed against each other by the operator. Further preferably, if a magnetic attraction force is acting between the locking parts, this force must be configured so as to be overcome by an operator.

Preferably, one locking part is provided on the operating element and the other locking part is provided on the at least one actuator. This configuration has the advantage that, when the locking parts are engaged with each other, the locking of the operating element along the second total distance is realised exclusively by the corresponding actuator and the operating element. Thereby the operating element cannot move back into its neutral position because the corresponding actuator is blocking this movement. Further, the corresponding actuator cannot move out of its locking position, since it is kept in this position by the operating element. Therefore, the locking mechanism according to this embodiment has no need for other separate parts as springs, pins etc. to realise the locking mechanism, wherein the locking mechanism is very reliable and has no need for extensive maintenance.

Additionally or alternatively, the locking mechanism is preferably configured to lock the at least one actuator on the total distance by applying a magnetic locking force. This embodiment of the locking mechanism can be used when no extra locking parts between the at least one actuator and the operating element are provided. But also in addition to such a locking mechanism, a magnetic locking force can be used to support the locking of the at least one actuator. Preferably, the operating element is provided with a resilient bias, configured to reset the operating element into a position along the second total distance which is a neutral position. Preferably, in the neutral position the operating element does not cause any movement of any actuator of the pneumatic control unit.

Preferably, the operating element is provided with a resilient bias, configured to move the operating element into the operating position. When the operating element is in the release position, this resilient bias causes the operating element to return to the operating position, wherein it can cause a movement of the at least one actuator by moving along the second total distance.

If a magnetic locking fore is used in particular to lock the at least one actuator along the total distance, the magnetic locking force is preferably applied on the at least one actuator. Preferably, when the at least one actuator is moved to the at least one locking position, the magnetic locking force is configured to lock the actuator in this position. Further preferably, when the at least one actuator is moved near the at least one locking position, the magnetic force is configured to move or to support the move of the at least one actuator into the locking position. This configuration has the advantage that especially manual operation of the at least one actuator becomes safer. Due to the magnetic attraction, the risk of stopping in an incorrect position of the at least one actuator along the entire distance is reduced. Preferably, the magnetic attraction force near the locking position is appropriately adjusted strong enough to move the at least one actuator into the locking position from a distance of 10% or less of the total distance, especially preferred 20% or less of the total distance, in particular 30% or less of the total distance.

Preferably, the magnitude of the magnetic attraction force in the locking position determines the predetermined release value.

Preferably, the locking mechanism is further comprising a locking element and a locking counterpart which are configured to generate the magnetic locking force, if the actuator is moved into the at least one locking position. The locking element and/or the locking counterpart are/is preferably comprising a magnet and/or a magnetic material. Additionally or alternatively the locking element and/or the locking counterpart are/is provided on the at least one actuator and/or in the housing.

Preferably, the pneumatic control unit is further comprising a reset mechanism

configured to reset the at least one actuator into a position along the total distance if at least one predetermined reset condition is met. Therefore, the at least one actuator can be reset by the reset mechanism. Additionally or alternatively, the reset mechanism is configured to move the operating element into the release position if at least one predetermined reset condition is met.

Depending on the embodiment of the pneumatic control unit, the predetermined release condition of the locking mechanism and the predetermined reset condition of the reset mechanism can be the same condition or separate conditions.

The predetermined reset condition is preferably the appearance of a pneumatic confirmation pressure and/or of an electric or electronic confirmation signal and/or a mechanical confirmation signal. The confirmation pressure can be supported to the pneumatic control unit by a system the pneumatic control unit is attached to. For example, if the pneumatic control unit is configured to control the raising and lowering of a body of a trailer, by the confirmation pressure and/or by the confirmation signal, a return-to-ride-function can be triggered. This pressure or signal is preferably supplied to the pneumatic control unit when the trailer is moved above a predetermined speed. Further, a reset condition can also be the dropping of the confirmation pressure or of the confirmation signal. For example, if the reset mechanism is configured to release the locking of the at least one actuator by moving the operating element into its release position, whereby this movement is caused by the pneumatic confirmation pressure, the reset of the operating element is completed when the confirmation pressure drops and the operating element is reset into its operating position which is for example caused by a resilient bias which is provided in the operating element. Preferably, the reset mechanism is comprising a reset element configured to transmit a reset force or a reset torque to the at least one actuator and/or to the operating element, wherein the reset force or the reset torque is further preferably configured to move the at least one actuator into a position, preferably into an end position along the total distance, and/or to move the operating element into its release positon. The reset force or the reset torque is preferably transmitted from the reset element to the at least one actuator wherein the reset element gets into contact with the at least one actuator. The reset element can be configured as a separate element or one actuator which is not locked by the locking mechanism can work as a reset element.

The pneumatic control unit preferably comprises a solenoid valve to control the pneumatic confirmation pressure, which is supplied to the pneumatic control unit in reaction to an electric confirmation signal acting on the solenoid valve.

The pneumatic control unit preferably comprises a solenoid actuator as a reset element, which is configured to reset the pneumatic control unit in reaction to an electric confirmation signal. For example the solenoid actuator is configured to move the operating element into its release position and/or to reset the at least one actuator.

An electric or electronic confirmation signal can be generated by a control unit.

The pneumatic confirmation pressure is preferably configured to unlock a reset element or to generate a force which is applied to the reset element. The pneumatic confirmation pressure is preferably supplied to the pneumatic control unit via a reset port.

Preferably, the reset element is configured to transmit the reset force or the reset torque by converting the pneumatic confirmation pressure into the reset force and/or by generating the reset force or the reset torque in an electric and/or electromagnetic way.

Additionally or alternatively, the reset element is provided on the at least one actuator. If the reset element is provided on an actuator, the reset element is preferably configured as a rod, which is configured to get into contact with at least another actuator to transmit the reset force or the reset torque to this actuator. Preferably, if the pneumatic control unit comprises at least two actuators wherein one actuator is locking the operating element on the second total distance as described above, the other actuator can be used as a reset element. Therefore, this actuator can transmit the operating element into its release position by moving this actuator in parallel to the total distance so as to abut at the operating element and to move it into its release position.

The at least one actuator is preferably configured as a slider. This actuator, especially the slider, is preferably configured to control at least one pneumatic pressure in at least one position on the total distance.

In an advantageous embodiment, the actuator is configured to control two pneumatic pressures, wherein in a first position on the total distance a first pressure is supplied to a first output port and in a second position on the total distance a second pressure or the first pressure is supplied to a second output port.

In another advantageous embodiment, the actuator is configured to control one pneumatic pressure, wherein in one position on the total distance a pressure is supplied to the output port. Preferably, the actuator is further configured to exhaust the output port in another position on the total distance.

The pneumatic control unit is preferably comprising at least one sealing element, which is configured to interact with the at least one actuator to connect or disconnect the ports of the pneumatic control unit. The at least one sealing element is preferably configured as an O-ring. The at least one sealing element is further preferably provided on the actuator or in the housing.

Further, the total distance preferably comprises a shape of a straight line or of at least a part of a circle line.

The reset element is preferably configured as a slider. Additionally or alternatively, the reset element is configured to be movable along at least one part of the total distance. Further preferably, the reset element is configured to be moved in parallel to the at least one actuator.

Preferably, the at least one actuator and/or the reset element are/is comprising an axle which is oriented in parallel to at least a part of the total distance.

The reset element is preferably not provided coaxially to the at least one actuator.

Preferably, the reset element is provided in the middle of two actuators. Preferably, the reset element is provided in a middle of a configuration of at least two actuators.

Preferably, the reset element, especially the axle of the reset element, comprises an equal distance from at least two actuators, especially from the axles of these actuators.

The at least one release condition is preferably met if a force or torque acting on the at least one actuator and/or on the operating element, especially along the total distance, exceeds a predetermined release value.

Preferably, the pneumatic control unit, especially the locking mechanism, is configured to apply an inhibit force or an inhibit torque on the at least one actuator while the at least one actuator is moved along the total distance. The inhibit force or the inhibit torque is preferably causing a resistance which has to be overcome by an operator while manually moving the at least one actuator. The resistance is preferably configured to ensure that the operator will move the at least one actuator into the at least one locking position.

The resistance, especially the inhibit force or the inhibit torque, is preferably generated by a magnetic mechanism. The magnetic mechanism is preferably comprising the locking element or the locking counterpart of the locking mechanism which is configured to interact with an element of the magnetic mechanism while the at least one actuator is moved along at least a part of the total distance.

Additionally or alternatively, the pneumatic control unit, especially the locking

mechanism, is comprising a guidance extending along the total distance, and a counterpart guided by the guidance. The counterpart and the guidance are configured to be relatively movable against each other when the at least one actuator is moved along the total distance and the guidance is configured to apply an inhibit force or inhibit torque on the at least one actuator and/or to lock the counterpart in the at least one locking position on the total distance. The inhibit force or inhibit torque is preferably acting as a peak force or peak torque against the movement of the at least one actuator along the total distance. This peak force or torque can give a haptic feedback to an operator moving the at least one actuator directly or via the operating element. For example, if the peak force or peak torque is applied to the at least one actuator, while the at least one actuator is reaching its locking position, the operator can feel this haptic feedback and thereby get the information that the locking position is reached.

The guidance is preferably comprising a tapered portion with a smaller aperture than the maximal extension of the counterpart guided in the guidance, and the tapered portion and/or the counterpart are/is configured to deform elastically, when the tapered portion and the counterpart are in contact by a force or torque which exceeds the predetermined release value.

The guidance is preferably located on the at least one actuator or in the housing, or the counterpart is preferably located on the at least one actuator or in the housing.

Preferably, the at least one actuator is configured to be moved against an elastic counterforce or countertorque while the at least one actuator is moved along at least one part of the total distance.

The elastic counterforce or countertorque is preferably generated by a spring.

Preferably, the elastic counterforce or countertorque is configured to act on the actuator in such way that the actuator is moved away from the at least one locking position.

Preferably, the reset element is provided with a resilient bias which is configured to generate the reset force or the reset torque if the reset condition is met, wherein preferably the resilient bias is configured to be released when the reset condition is met. Preferably, a pin can be provided which is configured to lock the reset element in a locked position. Further preferably, if the reset condition is met, the pin is configured to release the locking of the reset element while it is moved by the spring element. For example, the pin is configured to be moved by a force which is generated by the pneumatic confirmation pressure.

The reset force or the reset torque generated by the spring element is preferably configured to meet the release condition of the locking mechanism to unlock the at least one actuator and/or to reset the at least one actuator preferably to an end position and/or to move the operating element to its release position.

Preferably, the pneumatic pressure controlled by the at least one actuator is a pneumatic control pressure configured to control a pneumatic device.

According to the invention, a component for a pneumatic system is provided comprising a pneumatic control unit according to the invention.

The component is preferably configured as a park and/or shunt valve, a raising/lowering valve, or another pneumatic valve.

Additionally or alternatively, the pneumatic control unit is configured to control a pneumatic control pressure to control a park and shunt valve, a raising/lowering valve, or another pneumatic valve.

Additionally or alternatively, the system is configured as an air suspension system which is preferably configured for a trailer.

In a special embodiment of the invention, the pneumatic control unit is configured to control raising and/or lowering of a vehicle body especially of a vehicle body of a trailer. The at least one actuator is further preferably configured to be locked by the locking mechanism in a position along the total distance wherein a pneumatic pressure is supplied from the pneumatic control unit which causes raising or lowering of the vehicle body.

According to the invention, a trailer air suspension system is provided comprising a pneumatic control unit according to the invention, or a component according to the invention, wherein the trailer air suspension system is preferably configured to raise and lower a vehicle body especially of a trailer in response to the pneumatic pressure controlled by the pneumatic control unit. The trailer air suspension system is preferably comprising air bellows, wherein the air suspension system is configured to control the amount of air within the air bellows raise or lower the trailer. The amount of air is preferably controlled in reaction to the pneumatic control pressure controlled by the pneumatic control unit.

The embodiments and features described above can be combined with one another in any desired manner, wherein all embodiments that can be formed thereby are representing embodiments according to the invention.

Hereinafter, preferred embodiments of the invention are described by means of the attached drawings.

In detail,

Fig. 1 shows a sectional view of a part of a pneumatic control unit according to the present invention in a released end position, wherein the pneumatic control unit comprises a locking mechanism with a counterpart and a tapered portion,

Fig. 2 shows a sectional view of a part of the pneumatic control unit according to

Fig. 1 in a position wherein the counterpart and the tapered portion are in contact,

Fig. 3 shows a sectional view of the pneumatic control unit according to Fig. 1 and 2, wherein the locking mechanism is in a locked end position, Fig. 4 shows a sectional view of a pneumatic control unit according to the present invention wherein two actuators are in a locking position,

Fig. 5 shows a sectional view of the pneumatic control unit according to Fig. 4, wherein the two actuators are in a released position,

Fig. 6 shows a sectional view of a pneumatic control unit according to the

present invention comprising a magnetic locking mechanism,

Fig. 7 shows a pneumatic control unit comprising an operating element for

manual actuation,

Fig. 8 shows the pneumatic control unit according to Fig. 7, wherein the

operating element was rotated and thereby one actuator has been moved along the total distance, and

Fig. 9 shows the pneumatic control unit according to Fig. 7 and Fig. 8, wherein the operating element is in the release position.

Fig. 1 shows a sectional view of a part of a pneumatic control unit 15 according to the present invention in a released end position.

An actuator 1 is shown which is configured as a slider and provided slideable in a housing 6. The actuator 1 can be manually moved parallel to the shown direction 13 along a total distance 14 by a button 7 wherefore an operator can apply a force parallel to the direction 13 on the actuator 1.

The actuator 1 further comprises sealing elements 5 which are in contact to the housing 6 and configured to control a pneumatic pressure according to the position of the actuator 1 on the total distance 14. The actuator 1 is further configured to control a supply of a pneumatic pressure to an output port 16 which is configured to be connected to other pneumatic devices (not shown). The actuator 1 comprises a locking mechanism 2 which is marked up by a dotted frame. The locking mechanism 2 is configured to lock the actuator 1 in an end position. The locking mechanism 2 comprises a guidance 4 configured as a long hole extending along the total distance 14. The guidance 4 is located on the actuator 1. Further, the locking mechanism 2 comprises a counterpart 3 which is located in the housing 6 and which is configured as a pin which is guided in the guidance 4. The guidance 4 and the counterpart 3 are configured to be relatively movable to each other. Thereby, the extension dimension of the guidance parallel to the direction 13 defines the total distance 14 because if the counterpart 3 is in contact with the left or right end of the guidance 4, the actuator 1 can only be moved back so that the counterpart 3 and the end of the guidance 4 separate from each other again.

The guidance 4 is further provided with a tapered portion 4a. The tapered portion 4a comprises an aperture transverse to the direction 13 which is smaller than the maximum diameter of the counterpart 3. Further the tapered portion 4a is configured to deform elastically to increase the size of its aperture so that the counterpart 3 can be moved through the aperture.

The tapered portion 4a and the counterpart 3 have to be in contact under a force acting in parallel to the direction 13. The value of the force which is needed to deform the tapered portion 4a defines a release condition. If the release condition is met the locking of the locking mechanism 2 is released and the actuator can be moved parallel to the direction 13.

The working of the locking mechanism is described below. Therefore, reference is made in addition to Fig. 1 to Fig. 2 and Fig. 3.

Fig. 2 shows a sectional view of a part of the pneumatic control unit 15 according to Fig. 1 in a position wherein the counterpart 3 and the tapered portion 4a are in contact.

Fig. 3 shows a sectional view of a part of the pneumatic control unit 15 according to Fig. 1 and 2 in a locked end position. If the actuator 1 is moved by an operator along the direction 13, whereby the counterpart 3 and the tapered portion 4a get into contact, as shown in Fig. 2, the operator has to apply a force by pressing the button 7 into the direction 13. The force applied on the button 7 has to be higher than a predetermined release value. Since, the tapered portion 4a configured to be deformable elastically, as described above, the predetermined release value is essentially defined by the stiffness of the guidance, especially of the tapered portion 4a. Further, it is defined by the geometry of the tapered portion 4a and of the counterpart 3.

The counterpart 3 acting on the tapered portion 4a by the force of the operator causes the tapered portion 4a to increase the size of its aperture so that the counterpart 3 can be relatively moved with respect to the guidance 4.

Finally, the counterpart 3 has reached a left end position on the total distance 14 within the guidance, as shown in Fig. 3.

The counterpart 3 is now located on a left side of the tapered portion 4a in an end position and abutting against the end of the guidance 4. Therefore, the counterpart 3 cannot move to the left with respect to the guidance 4 and if no force comprising a value higher than the predetermined release value is acting on the actuator 1 contrary to the direction 13, the counterpart 3 can also not move to the right with respect to the guidance 4.

Therefore, the locking mechanism 2 is in a locked state and the actuator 1 is in a locking position.

In an alternative embodiment, the mechanism 2 shown in Fig. 1 to 3 is not configured as a locking mechanism 2. Instead, the guidance 4 and the counterpart 3 are configured in such way that only an inhibit force is applied to the actuator 1. An operator will realise the force generated between the tapered portion 4a and the counterpart 3 but the force is only configured to give a haptic feedback and to inform the operator that the locking position is nearly reached. The locking itself can here e.g. be realized by a locking mechanism 2 shown in Fig. 6.

Next, a pneumatic control unit according to the present invention will be described with respect to Fig. 4 and Fig. 5.

Fig. 4 shows a sectional view of a pneumatic control unit 15 according to the present invention wherein two actuators 1 , 1 a are in a locking position and Fig. 5 shows a sectional view of the pneumatic control unit 15 according to Fig. 4 wherein the actuators 1 , 1 a are in a released position.

The pneumatic control unit 15 is marked up by a dotted frame and provided in a housing 6 of a park and shunt valve 8 for a pneumatic brake control system of a trailer.

Further, the control unit 15 comprises two actuators 1 , 1 a which correspond to the actuator 1 shown in the Figures 1 to 3 but which are shown rotated about 90° around the direction 13. For a detailed description of these actuators 1 , 1 a, reference is therefore made to Figures 1 to 3.

Both actuators 1 , 1 a are configured to be manually operated by an operator applying a force to the buttons 7, 7a and are each comprising an output port 16, 16a configured to be connected to a pneumatic device, e.g. to a raising and lowering valve (not shown) of the trailer. By the output ports 16, 16a a pneumatic control pressure can be supplied to the raising and lowering valve, to trigger raising or lowering of a vehicle body of the trailer. For example, the lower actuator 1 is configured to supply the pneumatic control pressure which is configured to trigger the lowering and the upper actuator, the second actuator 1a, is configured to supply the pneumatic control pressure which is configured to trigger the raising of the vehicle body of the trailer.

Both actuators 1 , 1 a are configured to be moved parallel to the direction 13 over a total distance 14 which is defined according to the total distance 14 as shown in Fig. 1 to Fig. 3. The pneumatic control unit 15 further comprises a reset mechanism 9 which is marked up by a dotted frame in the drawings. The reset mechanism 9 is comprising a reset element 10 configured as a slider which is provided movable parallel to the direction 13. The reset element 10 further comprises a contact portion 12 provided on a left end of the reset element 10. The reset portion 12 is configured to abut to the button 7 and to the button 7a, if the reset element 10 is moved against the direction 13.

Further, the reset element 10 is configured to be moved in reaction to a pneumatic pressure which can be supplied to a reset port 11 of the reset mechanism 9. If the reset element 10 is not in the left end position and a pneumatic pressure is supplied to the reset port 11 , the reset element 10 is configured to move to the left, especially to the left end position. Therefore, the reset port 11 is connected to a chamber 17 located on a right end of the reset element 10, wherein the reset element 10 is configured to seal the chamber 17 by its right end and by a sealing element 18 located on the reset element 10 and which is in contact to the housing 6. The pneumatic pressure supplied to the chamber 17, therefore generates a force acting on the right end of the reset element 10. The pneumatic pressure supplied to the reset port 11 therefore acts as a pneumatic conformation pressure.

Since the actuators 1 , 1a are configured to be locked in their locking position by the locking mechanism 2, the reset element 10 is configured to release the locking and to move the actuators 1 , 1 a from the locking position to an end position. Therefore, the reset element 10 is configured to generate a force which corresponds at least to the predetermined release value. This force is applied to the actuator 1 , to the second actuator 1 a or to both actuators 1 , 1 a when the reset element 10 is moved to the left and the contact portion 12 abuts to a right side of the button 7, of the button 7a or of both buttons 7, 7a.

The reset function of the pneumatic control unit 15 works as follows. For simplification, the reset function is only described with reference to the lower actuator 7. The upper actuator 7a is reset in the same way. If an operator has pressed the button 7 and has moved the actuator 1 into the locking position as shown in Fig. 4, the right side of the button 7 abuts to the contact portion 12 of the reset element 10 and a pneumatic pressure is supplied via the port 16 to other devices of the system.

If the actuator 1 shall be reset, a pneumatic pressure has to be supplied to the reset port 11 wherein a force is generated in the chamber 17 acting on the right end of the reset element 10. If this force exceeds the predetermined release value, the reset element 10 abutting to the right side of the button 7 by the contact portion 12, moves to the left and therefore moves the actuator 1 out of the locking position.

Therefore, the reset element 10 is configured to reset the actuator 1 to a left end position as shown on Fig. 5.

In this case, the release condition defined by the predetermined release value of this force and the reset condition are identical.

Fig. 6 shows a sectional view of a pneumatic control unit 15 according to the present invention comprising a magnetic locking mechanism.

The pneumatic control unit 15 is marked up by a dotted frame and is comprising an actuator 1 configured as a slider which can be manually moved along the total distance 14 in parallel to the horizontal direction 13 which is heading to the left in the drawing. The actuator 1 is provided in a housing 6 and is shown in its locking position wherein the actuator 1 is moved to the left. The actuator 1 is essentially configured like the actuator 1 shown in the Figures above.

The right end of the actuator 1 is configured for manual operation and therefore comprising a button 7 on its right end. Further, the pneumatic control unit 15 is comprising a counterpart 3 and a guidance 4 as described in the Figures 1 to 3. Finally the actuator is comprising a sealing element 5 as described in the Figures 1 to 3. The actuator 1 comprises a locking mechanism 2 comprising a locking counterpart 20 provided on a left end of the actuator 1 in the drawing which abuts at a locking element 19 of the locking mechanism 2 in the shown position of the actuator 1. The locking mechanism 2 is marked up by a dotted frame. The locking element 19 is provided in the housing 6 and is comprising a magnet. The locking counterpart 20 comprises a magnetic material. Therefore, between the locking element 19 and the locking counterpart 20 a magnetic attraction force can be generated, if both elements 19, 20 approach to each other. The magnetic attraction force is further configured to move the actuator 1 into its locking position from a distance of 10% or less of the total distance, especially preferred 20% or less of the total distance, in particular 30% or less of the total distance.

Due to the magnetic attraction force between the locking element 19 and the locking counterpart 20, the actuator 1 is locked in the shown position on the total distance 14. The magnetic attraction force between the locking element 19 and the locking counterpart 20 is defining a release condition. If a force is acting on the actuator 1 against the direction 13 and if this force has a higher value than the value of the magnetic attraction force, the actuator 1 can be released from the locking position and moved to the right.

The release of the actuator 1 and further the reset of the actuator 1 to a predetermined position along the total distance 14 can be carried out by a reset mechanism as described in Fig. 4 and Fig. 5.

The invention is not limited to the embodiments described above. Each of the features of the embodiments shown in Fig. 1 to 6 can be combined with each other.

Furthermore, the actuator 1 can comprise a spring element configured to act against a movement of the actuator 1 in the direction 13. This causes a reset of the actuator 1 if it is not in the locking position at the right end of the total distance 14. This ensures that the actuator 1 is not accidentally placed in an intermediate position. The spring element is configured to generate a force while the actuator 1 is in the locking position which does not exceed the predetermined release value. Therefore, the actuator 1 can be locked despite of the spring element.

Furthermore, the actuation of the reset element 10 can be configured in a different way. For example the reset mechanism 9 comprises a spring element configured to act against the direction 13 on the reset element 10. Further, the reset mechanism 9 is comprising a locking mechanism configured to lock the reset element 10 when it is moved to a right end position as shown in Fig. 4, for example by the button 7 on which a force of an operator is applied. The locking mechanism of the reset mechanism 9 is further configured to release the locking of the reset element 10, if a pneumatic pressure, especially a pneumatic confirmation pressure, is supplied to the reset port 11. After releasing the reset element 10, it is moved to the left by the force of the spring element and since the right side of the button 7 abuts to the contact portion 12, the actuator 1 is also moved to the left into the left end position on the total distance 14. The spring element has further to be configured to generate a force which is at least the predetermined release value. This embodiment has the advantage that only a small pneumatic pressure is needed to release the reset element 10.

In the embodiments shown in the Figures, each actuator 1 , 1 a is only configured to control one pneumatic pressure via one port 16, 16a. Furthermore, such a pneumatic control unit 15 can also comprise actuators which are configured to control at least two control pressures depending on the position of the actuator on the total distance 14.

The total distance can further be configured as a circle or as a part of a circle, wherein the actuator is than operated by rotation. Therefore, the actuator can further comprise a lever configured for manual rotation of the actuator.

Further, the counterpart 3 can be configured to deform elastically, wherein the tapered portion 4a is configured to be stiff. Furthermore, the counterpart 3 as well as the tapered portion 4a can be configured to deform elastically.

Furthermore, the locking element 19 shown in Fig. 6 can also be provided on the actuator 1 wherein the locking counterpart 20 is provided in the housing. Further, the locking element 19 or the locking counterpart 20 do not necessarily have to be provided at the end of the actuator 1. Furthermore, every suitable position on the actuator 1 can be chosen. The other element 19, 20 which is provided in the housing 6 or at least fixed with respect to the actuator 1 , must be provided in such way that the magnetic attraction force between the elements 19, 20 can be increased to its maximum in the locking position.

Fig. 7 shows a pneumatic control unit comprising an operating element for manual actuation.

The upper part of Fig. 7 shows an operating element 30 configured as a rotating lever rotatable along a second total distance 35, which is defined by the angle range covered by the rotating lever. The operating element 30 can be rotated around an axis which is oriented in parallel to a direction 13, along to the total distance 14. The lower part of the drawing shows a sectional view of the pneumatic control unit 15 turned by 90°. The embodiment is described below using both drawings. The operating element 30 is provided with a resilient bias, generated by a reset spring (not shown) and acting on the operating element 30 to rotate the operating element 30 along the second total distance 35 back into the shown position, which is called neutral position.

The pneumatic control unit 15 comprises two actuators 1 , 1 a which are released and in an end position along the total distance 14.

Both actuators 1 , 1 a are configured to be manually moved by an operator applying a torque to the operating element 30. The pneumatic control unit 15 comprising output ports 16, 16a configured to be connected to a pneumatic device, e.g. to a raising and lowering valve (not shown) of the trailer. By the output ports 16, 16a a pneumatic control pressure can be supplied to the raising and lowering valve, to trigger raising or lowering of a vehicle body of the trailer. For example, the lower actuator 1 is configured to supply the pneumatic control pressure which is configured to trigger the lowering and the upper actuator, the second actuator 1 a, is configured to supply the pneumatic control pressure which is configured to trigger the raising of the vehicle body of the trailer. Both actuators 1 , 1 a are configured to be moved in parallel to the direction 13 over a total distance 14 which corresponds to the total distance 14 as shown in Fig. 1 to Fig. 3. On each actuators 1 , 1 a springs 37, 37a are acting which are pushing the actuators 1 , 1 a back into the shown positions over the total distance 14.

Between the operating element 30 and the actuators 1 , 1 a there is provided a

transmission surface 31 and a transmission counterpart 32, which are configured as corresponding surfaces. The transmission surface 31 is provided on the operating element 30 and the transmission counterpart 32 is provided on the left end of the actuator 1. On the left end of the other actuator 1 a there is provided a transmission counterpart 32a as well corresponding with another transmission surface (not shown) of the operating element 30. There are slopes provided on both surfaces 31 , 32 which are configured such that a rotary movement of the operating element 30 causes a movement of the actuator 1 along the total distance 14.

Further, a first locking part 33 is provided on the operating element 30 and a second locking part 34 is provided on the left end of the actuator 1. The locking parts 33, 34 are configured as protrusions. Next to the first locking part 33 there is provided a first blocking surface 38 on the operating element 30 and next to the second locking part 34 there is provided a second blocking surface 39 on the actuator 1. On the other actuator 1 a there is provided another blocking surface (not shown) as well, corresponding to another blocking surface of the operating element 30.

The pneumatic control unit 15 further comprises a reset mechanism 9 which is marked up by a dotted frame in the drawings. The reset mechanism 9 is comprising a reset element 10 configured as a slider or piston which is provided movable within the housing 6 and in parallel to the direction 13. The reset element 10 is connected to the operating element 30 so as the operating element 30 can be moved in parallel to the direction 13 by the reset element 10. As the reset element 10 has a circular cross section, it does not block the rotational movement of the operating element 30. Further, the reset element 10 is configured to be moved in reaction to a pneumatic confirmation pressure, as defined above, which can be supplied to a reset port 11 of the reset mechanism 9. If the reset element 10 is in the position shown in Fig. 7 and a pneumatic pressure is supplied to the reset port 11 , the reset element 10 is configured to move to the left direction as shown in Fig. 7. Therefore, the reset port 11 is connected to a chamber 17 located on a right end of the reset element 10, wherein the reset element 10 is configured to seal the chamber 17 by its right end and by a sealing element 18 located on the reset element 10 and which is in contact to the housing 6.

The pneumatic pressure supplied to the chamber 17, therefore generates a force acting on the reset element 10 against direction 13 as shown in Fig. 7. The pneumatic pressure supplied to the reset port 11 therefore acts as the pneumatic conformation pressure, to confirm that the reset of the pneumatic control unit 15 can be executed.

By the reset element 10 the operating element 30 can be moved to the left in the drawing into a release position wherein especially the locking parts 33, 34 are disengaged.

Further, a spring 36 is provided within the housing 6 acting on the reset element 10 whereby a force is applied onto the reset element 10 in the direction 13.

As the actuator 1 can essentially be locked by the locking parts 33, 34 as described later, the counterpart 3 and the guidance 4 which are provided at each actuator 1 , 1 a can be configured different to the embodiments described above with respect to Fig. 1 to 5. Flere, in the embodiment of Fig. 7, the counterpart 3 and the guidance 4 are configured to generate a peak force acting against the actuators 1 , 1 a when the corresponding actuator 1 , 1 a is moved along the total distance 14 in the direction 13. Thereby the peak force acts back to the operating element 30 so as to give a haptic feedback to an operator moving the operating element 30 that the end position of the corresponding actuator 1 , 1 a is reached.

To generate the peak force, the guidance 4 comprising a tapered portion 4a as described above, wherein the guidance 4 and the counterpart 3 are not strong enough to hold the corresponding actuator 1 , 1 a locked against the corresponding spring 37, 37a.

Further, the pneumatic control unit 15 comprises sealing elements 5 corresponding to the sealing elements 5 shown in the Figures 1 to 6.

The pneumatic control unit 15 works as follows. Additionally, reference is made to the drawings shown in Fig. 8 and 9.

Fig. 8 shows the pneumatic control unit 15 with a locked actuator 1 and Fig. 9 shows the pneumatic control unit 15 with the operating element 30 in a release position. The views of the drawings shown in Fig. 8 and Fig. 9 correspond to the views of Fig. 7.

In Fig. 8 an operator has rotated the operating element 30 into an end position on the second total distance 35. Thereby the actuator 1 was moved along the total distance 14 into its locking position as shown in the lower drawing of Fig. 8. Thereby the actuator 1 compressed the spring 37. The upper drawing of Fig. 8 shows the positions of the transmission surface 31 , the transmission counterpart and of the locking parts 33, 34 to each other. The transmission surface 31 does not abut to the transmission counterpart 32 any more. Instead, the locking parts 33, 34 are engaged with each other, whereby the reset spring acting on the operating element 30 cannot return the operating element 30 along the second total distance 35 into its neutral position. Therefore, the operating element 30 is locked on the second total distance 35 and the operating element 30 is locking the actuator 1 in its locking position as well by the blocking surfaces 38, 39 which are now abutting to each other.

In the position of the actuator 1 shown in Fig. 8, a pneumatic pressure is supplied via the port 16 to other devices of the system the pneumatic control unit is part of.

If the actuator 1 and the operating element 30 shall be reset, a pneumatic pressure has to be supplied to the reset port 11 wherein a force is generated in the chamber 17 acting from the right in the Figures on the reset element 10. If this force exceeds a predetermined release value which is the value of the force of the spring 36 acting on the reset element 30 in the direction 13, the reset element 10 moves the operating element 30 into its release position. This situation is show in Fig. 9. The locking parts 33, 34 are only configured to engage along the second total distance 35 but not to engage along the total distance 14. Therefore, the locking parts 33, 34 do not block the rotational movement of the operating element 30 any more. Therefore, the release condition of the locking mechanism 2 is met.

As shown on both drawings of Fig. 9, the locking parts 33, 34 are separated because the operating element 30 is in the release position. Further, the blocking surfaces 38, 39 are not abutting against each other any more. As the reset spring acting on the operating element 30, the operating element 30 is now moved back along the second total distance 35 into its neutral position on the second total distance 35 which is shown in Fig. 9.

As the operating element 30 was moved to the release position, the actuator 1 is moved to the left into the left end position along the total distance 14 by the spring 37 acting on the actuator 1. Therefore, the actuator 1 is now reset. When the chamber 17 is exhausted, for example by an exhaust port, which is overrun by the sealing element 18 and thereby causing communication from the chamber 17 to the exhaust port, when the reset element 10 is in the position shown on Fig. 9, the spring 36 acting on the reset element 10 moves the reset element 10 and the operating element 30 to the right, so as to reset the operating element 30 from its release position shown in Fig. 9 to its operating position shown in Fig. 7. Therefore, the operating element 30 is reset and the pneumatic control unit 15 can be operated again.

The embodiment shown in Fig. 7 to 9 comprises actuators 1 , 1 a which are provided with a resilient bias caused by springs 37, 37a against the direction 13. These springs 37, 37a cause a movement of the actuators 1 , 1 a against the direction 13, to reset them to the left end of the total distance 14.

In another embodiment, no springs 37, 37a are needed to reset the actuators 1 , 1 a. For example the reset element 10 is configured to transmit its movement to the actuators 1 , 1 a while it is moving to the left by abutting at the actuators 1 , 1 a. Thereby, the reset element 10 must move the operating element 30 over a longer distance to the left than the actuators 1 , 1a, are moved to release the locking parts 33, 34 from each other so that the operating element 30 is in its release position. This can be realized by a transmission means between the reset element 10 and the operating element 30.

In another embodiment the actuators 1 , 1a can be reset for example by a pneumatic force acting on the actuators 1 , 1 a and causing the reset movement of the actuators 1 ,

1 a to the left. If one of the actuators 1 , 1 a is thereby acting as a reset element 10 by abutting to the operating element 30, the corresponding actuator 1 , 1 a moves the operating element 30 into its release position. Therefore, a separate reset element 10 is not needed in this embodiment and the operating element 30 for example can be provided directly within the housing 6 and not within a separate reset element 10.

In general, if the locking mechanism is configured to lock the actuators 1 , 1 a along the total distance 14 independently from the locking parts 33, 34, for example by a magnetic locking force or by the guidance 4 and the counterpart 3, the reset mechanism 9 must be configured to reset the actuators 1 , 1 a separately. For example this can be realized by pressure supplied by the reset mechanism and acting on the actuators 1 , 1 a as a reset force, or by the reset element 10 configured to abut to the corresponding actuator 1 , 1a and to move it against direction 13 along the total distance 14.

Finally, special aspects of the invention are highlighted below.

According to a first aspect of the invention, a pneumatic control unit 15 for controlling a pneumatic pressure is provided, comprising:

- a housing 6,

- at least one actuator 1 , 1 a configured to be manually moved along a total distance 14 within the housing 6 and configured to control a pneumatic pressure depending on its position on the total distance 14, and

- a reset mechanism 9 configured to reset the at least one actuator 1 , 1 a into a position along the total distance 14 if at least one predetermined reset condition is met. According to a second aspect of the invention, the predetermined reset condition is the appearance of a pneumatic confirmation pressure.

According to a third aspect of the invention according to the first or second aspect, the reset mechanism 9 comprising a reset element 10 configured to transmit a reset force or a reset torque to the at least one actuator 1 , 1a, wherein

the reset force or the reset torque is preferably configured to move the at least one actuator 1 , 1a into an end position.

According to a fourth aspect of the invention according to the third aspect,

the reset element 10 is configured to transmit the reset force or the reset torque by converting the pneumatic confirmation pressure into the reset force, and/or

the reset element 10 is provided on the at least one actuator 1 , 1 a.

According to a fifth aspect of the invention according to any of the foregoing aspects, the pneumatic control unit 15, comprising:

- a locking mechanism 2 configured to lock the at least one actuator 1 , 1 a in at least one locking position along the total distance 14.

According to a sixth aspect of the invention according to the fifth aspect,

the at least one locking position is an end position on the total distance 14, and/or the locking mechanism 2 is configured to release the locking of the at least one actuator 1 , 1 a if at least one release condition is met.

According to a seventh aspect of the invention according to any of the foregoing aspects

the at least one actuator 1 , 1 a is configured as a slider, and/or

the total distance 14 comprises a shape of a straight line or of at least a part of a circle line.

According to an eighth aspect of the invention according to any of the aspects three to seven,

the reset element 10 is configured as a slider, and/or the reset element 10 is configured to be movable along at least one part of the total distance 14.

According to an ninth aspect of the invention according to any of the aspects six to eight,

the at least one release condition is met if a force or torque acting on the at least one actuator 1 , 1a especially along the total distance 14 exceeds a predetermined release value.

According to an tenth aspect of the invention according to any of the aspects five to nine,

the locking mechanism 2 comprising:

- a guidance 4 extending along the total distance 14 and

- a counterpart 3 guided by guidance 4, wherein

the counterpart 3 and the guidance 4 are configured to be relatively movable against each other when the at least one actuator 1 , 1a is moved along the total distance 14, and

the guidance 4 is configured to lock the counterpart 3 in the at least one locking position on the total distance 14.

According to an eleventh aspect of the invention according to the tenth aspect

the guidance 4 comprising a tapered portion 4a with a smaller aperture than the maximal extension of the counterpart 3 guided in the guidance 4, and

the tapered portion 4a and/or the counterpart 3 are/is configured to deform elastically, when the tapered portion 4a and the counterpart 3 are in contact by a force or torque which exceeds the predetermined release value.

According to a twelfth aspect of the invention according to aspect ten or eleven

the guidance 4 is located on the at least one actuator 1 , 1 a or in the housing 6, or the counterpart 3 is located on the at least one actuator 1 , 1a or in the housing 6.

According to a thirteenth aspect of the invention according to any of the foregoing aspects, the at least one actuator 1 , 1a is configured to be moved against an elastic counterforce or countertorque while the at least one actuator 1 , 1 a is moved along at least one part of the total distance 14, wherein

the elastic counterforce or countertorque is preferably generated by a spring.

According to a fourteenth aspect of the invention according to any of the aspects three to thirteen,

the reset element 10 is provided with a resilient bias which is configured to generate the reset force or the reset torque if the reset condition is met, wherein

the resilient bias is preferably configured to be released when the reset condition is met.

According to a fifteenth aspect of the invention according to any of the foregoing aspects,

the pneumatic pressure controlled by the at least one actuator 1 , 1a is a pneumatic control pressure configured to control a pneumatic device.

According to a sixteenth aspect of the invention a component for a pneumatic system is provided, comprising:

- a pneumatic control unit 15 according to one of the foregoing aspects, wherein the component is configured as a park and/or shunt valve, a raising/lowering valve, or another pneumatic valve, and/or

the pneumatic control unit 15 is configured to control a pneumatic control pressure to control a park and shunt valve 8, a raising/lowering valve, or another pneumatic valve, and/or

the system is configured as an air suspension system which is preferably configured for a trailer.

According to a seventeenth aspect of the invention a trailer air suspension system is provided, comprising:

- a pneumatic control unit 15 according to one of the foregoing aspects concerning the pneumatic control unit 15, or

- a component according to the foregoing aspect, wherein the trailer air suspension system is preferably configured to raise and lower a vehicle body especially of a trailer in response to the pneumatic pressure controlled by the pneumatic control unit 15.

LIST OF REFERENCE SIGNS

1 actuator

1 a second actuator

2 locking mechanism

3 counterpart

4 guidance

4a tapered portion

5 sealing element

6 housing

7 button

7a button

8 park and shunt valve

9 reset mechanism

10 reset element

1 1 reset port

12 contact portion

13 direction

14 total distance

15 pneumatic control unit

16 output port

17 chamber

18 sealing element

19 locking element

20 locking counterpart

30 operating element

31 transmission surface

32 transmission counterpart 32a transmission counterpart

33 locking part

34 locking part

35 second total distance

36 spring springa spring

blocking surface blocking surface