Patent Description:
Pneumatic valves of the aforementioned type are widely used in the vehicle industry. In particular, pneumatic valves of the aforementioned type are used as brake valves providing braking pressure for brake mechanisms. Under commercial vehicle, in particular busses, cargo vehicles such as trucks and other heavy duty vehicles are to be understood. The pneumatic valves receive pressurized fluid from a pressure source and provide pressurized fluid at a working pressure to a vehicle system or actuator, such as a brake actuator, brake caliper of a disk brake or a drum brake or the like. By sliding the valve member to the open position, pressurized air provided to the supply connection at the supply pressure is transmitted to the working connection at a working pressure that corresponds to the position of the valve member between the exhaust position and the open position. When the valve member is in the exhaust position, the working connection is vented and no fluid at working pressure is supplied. When the valve member is in the fully open position a working pressure substantially equal to the supply pressure will be supplied to the actuator. The valve member is movable between the exhaust position and the fully open position by an operator of the vehicle or based on electronic signals. For example, the valve member may be biased in the exhaust position and is movable from the exhaust position via a foot brake pedal attached to the valve member. When a user pushes the brake pedal, the valve member is moved. As soon as the user releases the brake pedal, the valve member returns to the exhaust position.

Conventional pneumatic valves comprise an exhaust silencer that reduces noise when an actuator or system connected to the pneumatic valve is vented via the pneumatic valve. Due to various reasons, for example to allow for foot actuation of a pneumatic valve functioning as brake valve, pneumatic valves are often installed close to a base of the vehicle (e.g. close to a cabin floor of the vehicle). However, a maximum fording depth of the vehicle is thereby limited. If a water level rises to the exhaust silencer while the vehicle drives through a stream or puddle, water ingresses into the brake valve and adversely affects the pneumatic valve. Therefore, fording versions of pneumatic valves have been developed. Instead of an exhaust silencer, the exhaust portion of such pneumatic valves is connected to a venting guide, which is then connected to an exhaust located at the top of the vehicle via a hose or pipe. It is further desirable to locate the exhaust outside of the vehicle cabin in order to reduce a noise for passengers of the vehicle. However, fording versions of pneumatic valves are prone to damage. During operation and/or assembly of the pneumatic valve, forces may be exerted on the venting guide that can result in the pneumatic valve being damaged. For example, the venting guide may be broken of the pneumatic valve, if excessive forces are exerted on the venting guide. An example of pneumatic valve is disclosed in <CIT>.

It is therefore an object of the invention to provide a pneumatic valve having increased resistance to damage.

The invention solves the above mentioned problem with a pneumatic valve according to claim <NUM>, in particular with a pneumatic valve of the aforementioned type, wherein the venting guide comprises a spout and a support projection, wherein the support projection is positioned adjacent to a contact region of the housing provided on the first housing side and configured to abut the contact region to prevent tilting of the venting guide relative to the housing. The inventors have found that most damages to pneumatic valves of the aforementioned type result from excessive forces on a spout of the venting guide. These forces are provided on the spout during assembly and/or during operation, for example by a hose connecting the venting guide to a high spot of a vehicle. In particular, vibrations of the hose may exert eccentric forces to the spout during operation of the vehicle. The forces provided on the spout lead to tilting of the venting guide relative to the engagement portion. Once the relative movement or tilt of the venting guide with respect to the engagement portion is too large, the connection elements may be damaged. Such damages to the connection elements may also result from continuous or alternating loads provided thereon which may lead to fatigue fractures or the like. Moreover, tilting of the venting guide can result in leakages and/or allow water to be ingressed into the pneumatic valve.

The solution found by the inventors is that tilting of the venting guide can be prevented by a support projection. The support projection preferably extends from a main venting guide body of the venting guide separately of the spout. However, the venting guide preferably is a one-piece construction. The support projection is positioned adjacent to a contact region of the housing, which is provided on the first housing side. The contact region is located proximate to the exhaust portion such that positioning of the support projection adjacent to the contact region is facilitated. The contact region preferably is a flat surface of the housing. The support projection preferably contacts the contact region when the complementary connection elements engage the attachment portion. Tilting of the venting guide relative to the housing is prevented by the support projection of the venting guide. It shall be understood that, the support projection inhibits not all movement of the venting guide relative to the housing. The support projection rather prevents excessive loads on the venting guide resulting from large deformations (excessive tilting). The support projection may allow for a slight tilt of the venting guide relative to the housing out of its neutral position. Such a slight tilt may be a tilt of less than <NUM>°, preferably less than <NUM>°, preferably less than <NUM>°. The venting guide prevents tilting relative to the housing, which may lead to damages during assembly or operation. In order to prevent excessive tilting of the venting guide relative to the housing, the support projection abuts the contact region such that forces provided on the venting guide, in particular on the spout of the venting guide, are transferred to the housing. The forces then need not be transferred by the complementary connection elements connecting the venting guide to the attachment portion. Damages to the complementary connection elements as well as leaks at the connection between the venting guide and the attachment portion are prevented. Naturally, extreme forces may still damage the venting guide. Preferably, the support projection is a lug. Disturbances of the attachment portion and any elements of the pneumatic valve connected thereto are reduced or prevented, since such disturbances may be transferred from the venting guide to the contact region instead of the attachment portion. Preferably, the venting guide comprises multiple support projections.

The support projection preferably comprises a support surface corresponding to a first contact surface of the contact region. For example and preferably, the support surface and the first contact surface may be flat surfaces. The support surface may also be a convex surface while the first contact surface is a corresponding concave surface or vice versa. Preferably, the support surface and/or the first contact surface are machined surfaces (i.e. no rough cast surfaces).

The spout is configured for connecting a hose or pipe thereto. The term spout does not imply a specific form. Preferably, the spout has the form of a cylindrical, rectangular or conical pipe. The spout may comprise elements that facilitate securing of a hose or pipe. Preferably, the spout may comprise a zigzag or saw tooth shaped outer surface or may comprise one or more projections on its outer surface.

The venting guide is configured to discharge pressurized air received from the brake valve to the environment. The attachment portion is preferably formed on or part of the exhaust portion. During operation and when the working connection of the pneumatic valve is vented, air passes from the working connection to the exhaust portion of the pneumatic valve. At the exhaust portion the air passes to the venting guide which then discharges the pressurized air from the pneumatic valve, for example via a hose or pipe attached to the spout. For example, the venting guide may be connected to a hose that transfers the pressurized air to an exhaust silencer spaced apart from the pneumatic valve when the pneumatic valve is installed in a vehicle. Preferably, the pneumatic valve is a brake valve and/or part of a brake system. Particularly preferred, the pneumatic valve is a brake valve suited for providing a brake pressure to a pneumatic vehicle brake system of a commercial vehicle.

The attachment portion preferably comprises connection elements. The connection elements of the venting guide and the connection elements of the attachment portion are preferably formed compatible to each other. The connection elements and/or the complementary connection elements may comprise slots for receiving hooks, one or more threaded portions, one or more hooks and/or one or more protrusions. Preferably, the connection elements and the complementary connection elements each form a respective bayonet connector half. It shall be understood that the connection elements and/or the complementary connections elements may also be formed by one element, only. For example, a single threaded portion may form the connection elements.

According to a first preferred embodiment, the spout is an essentially L-shaped spout having a first leg and a second leg. The second leg is proximate to the exhaust portion while the first leg extends from the second leg at a leg angle. The first leg is configured for attaching a further element such as a hose or pipe. The leg angle preferably lies in a range of <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, particularly preferred in a range of <NUM>° to <NUM>°. An L-shaped spout therefore does not necessarily comprise a <NUM>° leg angle. Pneumatic valves usually have an elongate shape with the exhaust portion located at first housing side transverse to a longitudinal axis. A straight type spout having a leg angle of <NUM>° would extend far from the housing and would further increase the length of the pneumatic valve. An L-shaped spout allows for a compact design of the pneumatic valve, since a hose or pipe may be laterally connected to the pneumatic valve. The L-shaped spout therefore facilitates assembly and/or integration of the pneumatic valve into a vehicle. Preferably, the complementary connection elements are formed on the second leg of the spout. The first leg preferably has a first leg length greater that a corresponding second leg length of the second leg. Preferably, the first leg length is twice as large as the second leg length or larger. Particularly preferred the leg length is in relation to a housing size of the housing.

In a further preferred embodiment, the support projection extends opposite the first leg of the L-shaped spout. The second leg and/or the complementary connection elements are preferably located between the first leg and the support projection in a first direction. The first direction is preferably parallel to the first contact surface of the housing. A support projection extending opposite of the first leg is particularly suited for supporting loads provided on the first leg, since leverage of the support projection is maximized. Forces provided on the first leg, for example by a hose or pipe connected thereto, are effectively transferred to the contact region of the housing. Opposite means that the first leg and the support projection are arranged on opposite sides of the venting guide. Preferably, the first leg and the support projection enclose an angle in a range of <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, particularly preferred <NUM>°.

Preferably, the venting guide comprises a venting channel having a first venting channel portion extending in the first leg and a second venting channel portion extending in the second leg of the L-shaped spout, wherein a tapered end portion of the first venting channel portion extends beyond an intersection between the first venting channel portion and the second venting channel portion. The venting channel directs pressurized fluid from the exhaust portion to a further discharge element (e.g. hose or pipe) connected to the spout. Preferably, the first venting channel portion and the second venting channel portions are straight channels. Preferably, the tapered end portion has a conical shape, particularly preferred a circle cone shape. A cone formed by the conical shape preferably has an opening angle in a range of <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, particularly preferred <NUM>° to <NUM>°. During operation, pressurized air is discharged from the pneumatic valve to the environment or another element via the venting channel. The air exerts forces on the venting guide, in particular at the intersection between the first venting channel portion and the second venting channel portion, since a flow direction of the air changes at the intersection. Moreover, a pressure gradient between the pneumatic valve and the environment may result in further loads or forces. The tapered end portion evenly distributes those forces. The tapered end portion may thus reduce a moment acting on the venting guide due to pressure in the venting channel. The venting channel may also have a first venting channel portion and a second venting channel portion without having a tapered end portion. For example, the first venting channel portion and the second venting channel portion may be connected by a bend and/or a corner. Preferably, a first internal cross section of the first venting channel portion is identical to a second internal cross section of the second venting channel portion.

The attachment portion and the complementary connection elements preferably allow rotation of the venting guide around a rotational axis when engaging each other. According to this embodiment, the complementary connection elements and the attachment portion allow movement around the rotational axis while the venting guide is fixed along the rotational axis. The complementary connection elements, the attachment portion and/or connection elements of the attachment portion may be formed rotationally symmetrical and/or point symmetrical. Preferably, the complementary connection elements are formed as hooks engaging a corresponding rim or groove of the attachment portion. The hooks may then slide in the groove or on the rim when the venting guide rotates around the rotational axis. The complementary connection elements and attachment portion allow rotation of the venting guide around a rotational axis which enables use of a single design of the pneumatic valve in multiple applications. This has a positive effect of cost associated to the pneumatic valve. For example, manufacturing cost of the pneumatic valve may be decreased. The rotational axis is preferably parallel, particularly preferred congruent, with a longitudinal axis of the pneumatic valve and/or of the housing. Preferably, the rotational axis is a central axis of the housing. The first direction preferably extends transverse to the rotational axis and/or the central axis.

In a further preferred embodiment, the venting guide engages a corresponding slot to prevent rotation of the venting guide around the rotational axis. As described above, forming the complementary connection elements and the attachment portion such that the venting guide is rotatable around a rotational axis allows for use of a single valve design for multiple applications. For example, the valve may be used in an application (e.g. in a first vehicle model) in that the spout is directed to a second side to the housing as well as another application (e.g. an alternative second vehicle model) that requires that the spout is directed to a third side of the housing opposite the second side. However, in certain applications a rotatable venting guide may not be desirable. This may be the case if a flexible hose is connected to the spout instead of a stiff pipe. Such a hose may twist when the venting guide rotates such that a flow passage inside the hose is blocked. The venting guide engaging the slot prevents rotation of the venting guide. This anti-rotation feature provided by the slot and the venting guide is formed separately of the complementary connection elements and the attachment portion. A slot is simple to manufacture such that the pneumatic valve may be easily adapted to specific applications. Preferably, the slot is formed in an external surface of the pneumatic valve. Preferably, the slot is formed in the housing. This allows for a stable anti-rotation feature provided by the protrusion and the slot, since the housing is already configured to receive loads. Preferably, the slot is formed in the first contact surface of the contact region of the housing. A housing configured for use in multiple applications may then be adapted to a specific application requiring a specific orientation of the spout with regard to the housing by machining the slot at a predefined location of the housing. Preferably, the slot is formed in an adapter connected to the housing. Preferably, the slot is exclusively formed in the adapter. The adapter is fixed to the housing in a rotationally free manner. That is, the adapter may not rotate around the rotational axis relative to the housing. With the help of the adapter, a housing that can be used for various applications can be adapted for an application requiring a specific orientation of the spout with regard to the housing. The adapter is preferably formed from a plastic material and/or metal. Preferably, the adapter is snap fitted, welded, screwed and/or glued to the housing. Use of an adapter allows for an economic adaption of the pneumatic valve to a specific application.

Preferably, a protrusion of the venting guide extends from the support projection towards the contact region. Preferably, the protrusion extends transverse to the first contact surface of the contact region of the housing and/or transverse to the support surface of the support projection.

In a preferred further development, the protrusion of the venting guide engages the slot. The protrusion then is an element at least partially dedicated to engaging the slot to prevent rotation of the venting guide. By forming the protrusion such that it extends from the support projection, the support projection and the protrusion prevent tilting as well as rotation.

Preferably, the contact region of the housing comprises a first contact surface and a second contact surface transverse to the contact surface, wherein the support projection is positioned adjacent to the first contact surface and configured to abut the first contact surface to prevent tilting of the venting guide relative to the housing in a first tilt direction, and wherein the protrusion is positioned adjacent to the second contact surface and configured to abut the second contact surface to prevent tilting of the venting guide relative to the housing in a second tilt direction opposite the first tilt direction. The support projection and its protrusion then prevent tilting of the venting guide in two opposing directions. For example, the support projection may contact the first contact surface to prevent tilting of the venting guide relative to the housing in a clockwise direction while the support projection abutting the second contact surface may prevent tilting of the venting guide relative to the housing in a counter-clockwise direction. The second contact surface preferably is a circumferential surface of the housing, particularly preferred an inner circumferential surface of the housing.

According to a preferred embodiment, the pneumatic valve further comprises a guide element, wherein the valve member is slidably arranged on the guide element, the guide element comprising an internal channel, wherein the internal channel forms part of an exhaust flow path between the working connection and the exhaust portion when the valve member is in the exhaust position.

Preferably, the venting guide is formed separately from the guide element and the attachment portion is formed on the guide element. The venting guide is then attached to the guide element by the complementary connection elements engaging the attachment portion.

Preferably, the pneumatic valve further comprises a valve sealing member provided at a transition between the internal channel and the venting channel for establishing a sealing connection between the venting guide and the guide element. Leaks of pressurized air from the exhaust flow channel. Preferably, the venting guide is sealingly connected to the internal channel of the guide element. Preferably, a valve sealing surface is provided on the guide element. The valve sealing member may be provided at the connection between the venting guide and the guide element. The guide element comprises a sliding surface on which the valve member is slidably arranged. This sliding surface needs to be precise. The guide element is preferably machined and/or (injection-molded. Preferably, the guide element is made from plastic material. During manufacturing and/or molding of the precise sliding surface, the attachment portion and preferably also the valve sealing surface may be formed at a high precision with little additional effort. Manufacturing time and cost of the brake valve as a whole can be reduced. Moreover, a spatial relation of the internal channel, the connection elements and/or the valve sealing surface is ensured which prevents assembly errors. In other embodiments, the guide element is preferably formed by additive manufacturing (3D-printing).

In a preferred embodiment, the venting guide is snap fitted to the attachment portion. Preferably, the snap fit is releasable. A releasable snap fit may be disengaged without destroying a connection element. The snap fit may also be inseparable, such that the venting guide may only be disengaged from the attachment portion by braking a corresponding connection element and/or a connection element of the attachment portion. A snap fit is an assembly method used to attach (partially) flexible parts to form the final product by pushing interlocking components together. The snap fit may be a cantilever, torsional and/or annular type snap fit. The snap fit facilitates assembly and requires no loose parts such as circular springs.

In a preferred embodiment, the venting guide comprises one or more reinforcement ribs extending from the support projection towards a main venting guide body of the venting guide. The second leg of the spout may be formed by the main body. The complementary connection elements are preferably formed on the main body or preferably extend therefrom. The reinforcement ribs preferably extend at a rib angle in a range of <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, preferably <NUM>° to <NUM>°, from the support projection. By providing reinforcement ribs, deformation of the support projection is effectively prevented without requiring a thick support projection. The reinforcement ribs are particularly useful for strengthening the support projection, when the protrusion engaging the slot extends from the support projection. Rotational forces provided on the venting guide may be transferred to the housing via the protrusion while the reinforcement ribs prevent bending of the support projection. However, it shall be noted that the reinforcement ribs are not essential to a support projection comprising a protrusion engaging a slot.

Preferably, a gap is formed between the contact region and the support projection when the venting guide is in a neutral position. The gap allows for facilitated assembly and manufacturing of the pneumatic valve, since the individual subparts of the pneumatic valve may be manufactured with less precision. The venting guide tilts slightly when a tilting force is applied to the venting guide such that the gap between the support projection and the contact region is closed in a loaded position. The venting guide is in its neutral position, when no external forces are applied to the venting guide. It shall be understood, that the gap is a small free space between two regions or surfaces configured to be brought into contact with each other (the contact region and the support projection). A gap is a small space having a gap width that allows compensation of manufacturing tolerances. The gap preferably has a gap width in a range of larger than <NUM> to <NUM>, preferably <NUM> to <NUM>, preferably <NUM> to <NUM>, preferably <NUM> to <NUM>, particularly preferred <NUM> to <NUM>, when the venting guide is in the neutral position. Preferably, the support surface and the first contact surface are parallel when the venting guide is in the neutral position.

Preferably, the contact region forms an end stop for the venting guide preventing excessive loads on the attachment portion when the venting guide is assembled on the attachment portion. In particular, when the venting guide is attached to the attachment portion via a snap fit, assembly forces need to be provided on the venting guide during its assembly on the attachment portion. The end stop may prevent overloading the attachment portion, since excessive assembly loads may be transferred from the support projection to the housing.

According to a second aspect of the invention, the above stated problem is solved by a vehicle comprising a brake system comprising a pneumatic valve according to the first aspect of the invention. The vehicle preferably is a commercial vehicle. The brake system preferably is a pneumatic brake system. In a particularly preferred embodiment, the pneumatic valve is a brake signal transmitter and/or a foot brake valve of the brake system. The brake system may comprises one or more brake circuits, one or more brake actuators, one or more pressurized air supplies and/or one or more brake modulators. The vehicle preferably comprises at least two axles.

It should be understood that the pneumatic valve according to the first aspect of the invention and the vehicle according to the second aspect of the invention preferably have similar or equal aspects, in particular as they are described in the dependent claims. Thus, reference is made to the above description of the pneumatic valve according to the first aspect of the invention.

For a more complete understanding of the invention, the invention will now be described in detail with reference to the accompanying drawings. The detailed description will illustrate and describe what is considered as preferred embodiments of the invention. It should of course be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention may not be limited to the exact form and detail shown and described herein, nor to anything less than the whole of the invention disclosed herein and as claimed herein after. Further, the features described in the description, the drawings and the claims disclosing the invention may be essential for the invention considered alone or in combination. In particular, any reference signs in the claims shall not be construed as limiting the scope of the invention. The wording "comprising" or "including" does not exclude other elements or steps. The word "a" or "an" does not exclude the plurality. The wording "a number of" items comprising also the number <NUM>, i.e. a single item, and further numbers like <NUM>, <NUM>, <NUM> and so forth.

A vehicle <NUM>, in particular a commercial vehicle <NUM>, comprises a front axle <NUM> and a rear axle <NUM>. For braking front wheels <NUM>, <NUM> of the front axle <NUM> and rear wheels <NUM>, <NUM> of the rear axle <NUM> the vehicle <NUM> comprises a brake system <NUM> having a front axle brake circuit <NUM> for braking the front wheels <NUM>, <NUM> and a rear axle brake circuit <NUM> for braking the rear wheels <NUM>, <NUM>. For braking the wheels <NUM>, <NUM>, <NUM>, <NUM>, the brake system <NUM> comprises front axle brake actuators <NUM>, <NUM> and rear axle brake actuators <NUM>, <NUM>. The front axle brake actuators <NUM>, <NUM> are connected to a front axle brake modulator <NUM> while the rear axle brake actuators <NUM>, <NUM> are connected to a rear axle brake modulator <NUM>. For providing compressed air at a supply pressure pS, the brake system <NUM> comprises a compressed air supply <NUM>. Of course, it may comprise more than one air supply.

In order to brake the vehicle <NUM> a brake pressure pB needs to be supplied to the front axle brake modulator <NUM> and the rear axle brake modulator <NUM>. For providing the brake pressure pB, the brake system <NUM> comprises a brake valve <NUM>. In this embodiment, a pneumatic valve <NUM> forms the brake valve <NUM>. The pneumatic valve <NUM> comprises a housing <NUM>, having a supply connection <NUM>, a working connection <NUM>, and an exhaust portion <NUM>. The supply connection <NUM> is conected to the compressed air supply <NUM> via supply line <NUM> for receiving pressurized air at the supply pressure pS.

In this embodiment the pneumatic valve <NUM> is configured for manual actuation by a user. However, the pneumatic valve <NUM> may also be formed as an electronically actuated pneumatic valve <NUM>. Upon actuation by a user the pneumatic valve <NUM> forming the brake valve <NUM> provides a brake pressure pB corresponding to the degree of actuation provided by the user. To allow an actuation, the pneumatic valve <NUM> comprises an actuation element <NUM>, which is formed as a brake pedal <NUM> in this embodiment. The brake valve <NUM> is configured to modulate the brake pressure pB supplied to the working connection <NUM> dependent on a degree of actuation of the actuation element <NUM>. If the brake pedal <NUM> is only slightly actuated, a low brake pressure pB is supplied to the working connection <NUM> while a high brake pressure pB is supplied to the working connection <NUM> when the brake pedal <NUM> is fully actuated.

The pneumatic valve <NUM> is connected to the front axle brake modulator <NUM> and the rear axle brake modulator <NUM> via connecting lines <NUM>, <NUM>. In this embodiment, the pneumatic valves <NUM> is formed as a single circuit brake valve <NUM> having only one working connection <NUM> for providing brake pressure pB. Both, the front axle connecting line <NUM> connecting the brake valve <NUM> to the front axle brake modulator <NUM> as well as the rear axle connecting line <NUM> connecting the brake valve <NUM> to the rear axle brake modulator <NUM> are connected to the same working connection <NUM> of the brake valve <NUM>. In other embodiments, the pneumatic valve <NUM> could also be formed as a multi circuit pneumatic valve <NUM> having multiple working connections <NUM> for providing the same and/or different pressures.

The brake modulators <NUM>, <NUM> receive the brake pressure pB provided by the brake valve <NUM> and provide pressurized air at the same brake pressure pB but at a higher volume to the respective brake actuators <NUM>, <NUM>, <NUM>, <NUM>. Therefore, the brake modulators <NUM>, <NUM> are also connected to the compressed air supply via supply lines <NUM>, <NUM>. It shall be noted that the front axle brake modulator <NUM> and/or the rear axle brake modulator <NUM> may also be configured to further modify the brake pressure pB. For example, the front axle brake modulator <NUM> could comprise ABS-modules (not shown) for providing an ABS-function. Moreover, the brake actuators <NUM>, <NUM>, <NUM>, <NUM> may also be directly connected to the brake valve <NUM>.

For releasing the brake of the vehicle <NUM>, the break pressure pB needs to be released from the brake actuators <NUM>, <NUM>, <NUM><NUM>. The pneumatic valve <NUM> is therefore configured to exhaust the brake actuators <NUM>, <NUM>, <NUM><NUM> by connecting the working connection <NUM> to the exhaust portion <NUM>. In order to exhaust pressurized air, the air needs to be released to the environment through an opening. Such an opening, however, allows water to enter the brake system <NUM>. Brake valves, in particular brake valves having a brake pedal, are usually located in a low position of the vehicle <NUM>. A maximum fording depth of the vehicle <NUM> is thereby limited, since water could ingress in the brake system <NUM> via the exhaust portion <NUM> when the vehicle <NUM> drives through water and the water level reaches to the exhaust portion. In regular vehicles, the available maximum fording depth is sufficient and pneumatic valves <NUM> of a standard type may be used as the brake valve <NUM>. If however, increased fording depths are needed, special measures need to be taken. Therefore, fording versions of pneumatic valves <NUM>, in particular pneumatic brake valves <NUM>, are provided.

In <FIG>, the brake valve <NUM> is a fording version, since the pneumatic valve <NUM> forming the brake valve <NUM> comprises a venting guide <NUM>. The venting guide <NUM> is connected to an exhaust line <NUM>, which is connected to a remote exhaust silencer <NUM>. For releasing the brakes of the vehicle <NUM>, the brake pressure pB is released from the brake actuators <NUM>, <NUM>, <NUM><NUM> via the connecting lines <NUM>, <NUM>, the brake valve <NUM> and its venting guide <NUM>, the exhaust line <NUM>, and the remote exhaust silencer <NUM>.

The venting guide <NUM> is sealingly connected to an attachment portion <NUM> of the pneumatic valve <NUM> and thereby enables a sealing connection between the pneumatic valve <NUM> and the exhaust line <NUM>. The remote exhaust silencer <NUM> is spaced apart from the brake valve <NUM> and placed at a high position on the vehicle <NUM>. By placing the exhaust silencer <NUM> at a high position of the vehicle <NUM>, ingress of water into the brake system <NUM> is prevented when the vehicle <NUM> drives through water. Providing the exhaust silencer <NUM> remote of the pneumatic valve <NUM> may be desirable for noise protection in other applications. For example, passengers may be protected from excessive noise by placing the exhaust silencer <NUM> at a location remote from a passenger cabin, when the commercial vehicle <NUM> is a bus.

<FIG> shows the pneumatic valve <NUM> forming the brake valve <NUM> depicted in <FIG> in more detail. The housing <NUM> defines a first valve cavity <NUM> and a second valve cavity <NUM>. A piston <NUM> of the actuation element <NUM> is slidably arranged in the first valve cavity <NUM>. A valve member <NUM> and a guide element <NUM> are arranged in the second valve cavity <NUM>. The valve member <NUM> is slidably arranged on the guide element <NUM> such that it is movable between an exhaust position <NUM> shown in <FIG> and a fully open position <NUM>. In the exhaust position <NUM> a fist valve member side <NUM> of a valve member head <NUM> of the valve member <NUM> abuts a first valve seat <NUM> arranged on a transition <NUM> between the first valve cavity <NUM> and the second valve cavity <NUM>. As will be explained in more detail below, movement of valve member <NUM> is possible due to contact between a piston head <NUM> and valve member head <NUM>. In the fully open position <NUM> the piston <NUM> abuts a hard stop <NUM> formed by the housing on the transition <NUM> between the first valve cavity <NUM> and the second valve cavity <NUM>. The hard stop <NUM> limits the pistons <NUM> range of movement such that the valve member <NUM> reaches the fully open position <NUM> when the piston <NUM> contacts the hard stop <NUM>. In the fully open position <NUM>, a second valve member side <NUM> of the valve member head <NUM> and the guide element <NUM> are preferably spaced apart to prevent damages on the valve member <NUM>. A distance between valve member <NUM> and valve seat <NUM> reaches its maximum, when the piston <NUM> reaches the fully open position <NUM> (i.e. abuts the hard stop <NUM>). Since the stop function is already provided by the hard stop <NUM>, no physical contact is required between the second valve member side <NUM> and the guide element <NUM>. Thus, the valve member <NUM> is prevented from damages. The valve member <NUM> is biased into the exhaust position <NUM> by a return spring <NUM> arranged between the second valve member side <NUM> and a bottom section <NUM> of the guide element <NUM>.

The guide element <NUM> is inserted into the second valve cavity <NUM> from a first housing side <NUM> and held in place by a lock ring <NUM>. For leak prevention between an outer circumferential face <NUM> of the guide element <NUM> and an inner wall <NUM> of the housing <NUM> defining the second valve cavity <NUM>, an O-ring <NUM> is provided between the guide element <NUM> and the inner wall <NUM>.

The piston <NUM> is inserted into the first valve cavity <NUM> from a second housing side <NUM>. Another O-ring <NUM> is provided between the piston <NUM> and a second inner wall <NUM> of the housing <NUM> defining the first valve cavity <NUM>. The piston <NUM> sealingly closes off the first valve cavity <NUM> and is movable between a released position <NUM> shown in <FIG> and a fully actuated position. In the fully actuated position the piston head <NUM> of the piston <NUM> abuts the valve member head <NUM> on the first valve member side <NUM> and the piston <NUM> abuts the hard stop <NUM> formed by the housing on the transition <NUM> between the first valve cavity <NUM> and the second valve cavity <NUM>.

The piston <NUM> is biased towards the released position <NUM> (in <FIG> upwards) by a piston spring <NUM> such that the piston <NUM> remains in the released position <NUM> as long as no force larger than a corresponding force provided by the piston spring <NUM> is provided to the brake pedal <NUM>. A pressure piece <NUM>, a set spring <NUM> and a spring seat <NUM> functionally connect the brake pedal <NUM> to the piston <NUM>. A push rod <NUM> of the brake pedal <NUM> is received in the pressure piece <NUM>, which is in turn slidably received in a cover <NUM> closing the housing <NUM> on the second housing side <NUM>. The spring seat <NUM> is received in a transfer cavity <NUM> of the piston <NUM>. A connector <NUM> is screwed on a threaded portion <NUM> of the pressure piece <NUM> and extends through the spring seat <NUM>. The cover <NUM> is fixed to the housing <NUM> and limits movement of the pressure piece <NUM> away from the piston <NUM> (in <FIG> upwards). The set spring <NUM> is arranged between the pressure piece <NUM> and the spring seat <NUM> and around the connector <NUM> for biasing the spring seat <NUM> away from the pressure piece <NUM>. The connector <NUM> is slidably received in the spring seat <NUM>. However, a screw head of a screw <NUM> limits movement of the pressure piece <NUM> together with connector <NUM> away from the spring seat <NUM> such that a maximum distance between the pressure piece <NUM> and the spring seat <NUM> is reached when the screw head of the screw <NUM> abuts the spring seat <NUM>. The set spring <NUM> between pressure piece <NUM> and spring seat <NUM> creates the pneumatic characteristic of the pneumatic valve <NUM>. A maximum stroke of set spring <NUM> is reached when the pressure piece <NUM> touches the piston <NUM>. During assembly spring seat <NUM>, pressure piece <NUM>, set spring <NUM> and connector <NUM> are assembled together, wherein the screw <NUM> connects spring seat <NUM> to connector <NUM>. This preassembly is then assembled in piston <NUM>. Moreover, the piston spring <NUM> pushes the piston <NUM> and the spring seat <NUM> towards the second housing side <NUM> (upwards in <FIG>). The screw <NUM> sets dependent on its position a "<NUM> position" between spring seat <NUM> and connector <NUM> attached to pressure piece <NUM>. When the screw <NUM> is loosened, a space between the pressure piece <NUM> and the spring seat <NUM> is increased such that the pre-tension of the set spring <NUM> is decreased.

Upon actuation of the brake pedal <NUM>, the pressure piece <NUM> moves towards the first housing side <NUM> (in <FIG> downwards). This movement compresses the set spring <NUM> and the pressure piece <NUM> moves towards the spring seat <NUM>. The set spring <NUM> provides a compression counter force to the spring seat <NUM> and the piston <NUM>, which in turn moves the piston <NUM> downwards against the piston spring <NUM> arranged between the piston <NUM> and the housing <NUM>. Hence, actuation of the brake pedal <NUM> leads to compression of the piston spring <NUM> as well as the set spring <NUM>. An extent by which the pressure piece <NUM> and the piston <NUM> move, depends on the compression counter forces (or biasing forces) provided by the set spring <NUM> and the piston spring <NUM>, since the forces provided by the set spring <NUM> and the piston spring <NUM> need to be in equilibrium as long as the pressure piece <NUM> is spaced apart from the piston <NUM>. Once the set spring <NUM> has been compressed such that the pressure piece <NUM> abuts the piston <NUM>, the pressure piece <NUM> and the piston <NUM> move in unison. Further actuation of the brake pedal <NUM> moves the piston <NUM> towards the fully open position <NUM> (in <FIG> downwards), since a direct connection is established between the brake pedal <NUM> and the piston <NUM> via the push rod <NUM> and the pressure piece <NUM>.

The set spring <NUM>, the spring seat <NUM> and the screw <NUM> provide means for setting a pedal feedback of the brake pedal <NUM>. When the set spring <NUM> is pretensioned to a high degree, the piston <NUM> is moved at a light actuation of the brake pedal <NUM>, since large forces are required for further compressing the set spring <NUM>. When, on the other hand, pre-tensioning of the set spring <NUM> is low, the pressure piece <NUM> performs a free stroke (or empty stroke) towards the piston <NUM> upon initial actuation of the brake pedal <NUM>, since almost no force is required for compressing the set spring <NUM>. In this case, when the brake pedal <NUM> is initially moved, only the pressure piece <NUM> moves towards the piston <NUM> while the piston <NUM> itself substantially maintains its position. The valve member <NUM> substantially maintains its position as well and consequently no brake pressure pB is provided to the working connection <NUM>.

After a potential free stroke of the pressure piece <NUM>, the piston <NUM> is moved from the released position <NUM> towards the fully open position (in <FIG> downwards) against the biasing force provided by the piston spring <NUM>. In between the released position <NUM> and the fully open position, the piston head <NUM> abuts the valve member <NUM> whereby a sealing contact is formed between the piston head <NUM> and the valve member head <NUM>. When the piston <NUM> is further actuated by the brake pedal <NUM>, it pushes the valve member <NUM> from the exhaust position <NUM> towards the fully open position <NUM>. The piston <NUM> is biased towards the released position <NUM> by the piston spring <NUM> arranged between the piston <NUM> and the housing <NUM> such that the piston <NUM> returns to the released position <NUM> when no actuation force is applied to the brake pedal <NUM>.

The guide element <NUM> comprises an internal channel <NUM> and a through hole <NUM> is provided in the valve member head <NUM> such that the first inner cavity <NUM> is in fluid communication with the exhaust portion <NUM> of the brake valve <NUM>, when the piston head <NUM> is separated from the valve member head <NUM> (when the piston <NUM> is in the released position <NUM>). When the actuation element <NUM> is at least partly actuated, the piston head <NUM> sealingly contacts the valve member head <NUM> and thereby separates the exhaust portion <NUM> from the fist valve cavity <NUM>. However, the valve member <NUM> is then in an at least partially open position wherein the valve member head <NUM> is separated from the valve seat <NUM> such that the second valve cavity <NUM> is in fluid communication with the first valve cavity <NUM>.

The supply connection <NUM> is in direct fluid communication with the second valve cavity <NUM> such that pressurized air at the supply pressure pS is provided thereto. When the valve member <NUM> is in the exhaust position <NUM> the second valve cavity <NUM> is closed off from the first valve cavity <NUM> and the exhaust so that the supply connection <NUM> is not directly connected to the exhaust. When a brake pressure shall be applied to the working connection <NUM> while the valve member <NUM> is in the exhaust position <NUM>, the brake pedal <NUM> needs to be actuated (pushed downwards with respect to <FIG>). The piston <NUM> then moves against the biasing force of the piston spring <NUM> and abuts the valve member head <NUM> with its piston head <NUM>. The valve member head <NUM> is moved out of the exhaust position and a free space is formed between the valve seat <NUM> and the first valve member side <NUM> of the valve member head <NUM>. Pressurized air provided to the second valve cavity <NUM> via the supply connection <NUM> may then flow from the second valve cavity <NUM> to the first valve cavity <NUM>. The working connection <NUM> is in direct fluid communication with the first valve cavity <NUM> such that pressurized air at the brake pressure pB is supplied to the working connection <NUM> when the valve member <NUM> is an at least partially open position. The pressure level of the brake pressure pB depends on the size of the free space formed between the valve seat <NUM> and the valve member head <NUM>. If the free space is small, a high pressure drop occurs and the brake pressure pB supplied to the working connection <NUM> is much smaller than the supply pressure pS. When the valve member <NUM> is in the fully open position <NUM>, a large free space is formed between the valve seat <NUM> and the valve member head <NUM> such that the brake pressure pB is substantially equal to the supply pressure pS. In this case, the brake actuators <NUM>, <NUM>, <NUM>, <NUM> connected to the working connection <NUM> are fully actuated and a maximum braking force is applied.

It shall be noted, that movement of the piston <NUM> depends on actuation of brake pedal <NUM> and deflection of set spring <NUM> as well as additional factors like friction and a force supplied by return spring <NUM>. The set spring <NUM> deflects, since the brake pressure pB established in the first valve cavity <NUM> acts on the exposed area of the piston <NUM> facing towards the first valve cavity <NUM>. As the free space between the valve member head <NUM> and the valve seat <NUM> increases, the brake pressure pB also increases. The set spring <NUM> is deflected (compressed) such that part of a movement of the pressure piece <NUM> towards the first housing side <NUM> is compensated by set spring <NUM>. Movement of the piston <NUM> is therefore not necessarily uniform to a movement of push rod <NUM> and pressure piece <NUM>. A partial braking characteristic of the brake valve <NUM> is configurable via set spring <NUM>. When the set spring <NUM> is fully compressed, the pressure piece <NUM> contacts piston <NUM> and a uniform movement of piston <NUM> and push rod <NUM> is established. Preferably, contact of piston <NUM> and pressure piece <NUM> results in a sudden increase of the free space between the valve seat <NUM> and valve member head <NUM> resulting in a jump of the pressure level of the brake pressure pB supplied to the first valve cavity <NUM> and working connection <NUM>. Further preferred, a pressure level of brake pressure pB substantially equal to the supply pressure pS is established when the pressure piece <NUM> abuts piston <NUM>.

When the brake pedal <NUM> is released, the piston <NUM> and the valve member <NUM> are returned to the released position <NUM> and the exhaust position <NUM> respectively by the springs <NUM>, <NUM>. The valve member head <NUM> abuts the valve seat <NUM> and separates the first valve cavity <NUM> from the second valve cavity <NUM>. Once the valve member <NUM> has reached the exhaust position <NUM>, further movement of valve member <NUM> is stopped by the valve seat <NUM>. The piston <NUM>, however, moves on such that the piston head <NUM> separates from the valve member head <NUM>. The first valve cavity <NUM> is then once again in fluid communication with the exhaust portion <NUM> via the through hole <NUM> and the internal channel <NUM>. Pressurized air at the brake pressure pB may then flow along an exhaust flow path <NUM> from the working connection <NUM> to the exhaust portion <NUM> via the first valve cavity <NUM>, the free space formed between the piston head <NUM> and the valve member head <NUM>, the through hole <NUM> and the internal channel <NUM> formed in the guide element <NUM>.

The exhaust portion <NUM> is configured for exhausting air from the pneumatic valve <NUM>. While regular pneumatic valves directly exhaust the air to the environment via an exhaust silencer connected to the exhaust portion <NUM>, the exhaust portion <NUM> of the pneumatic valve <NUM> shown in <FIG> does not directly exhaust the pressurized air to the environment. Instead, the pressurized air is provided to the venting guide <NUM>. The exhaust portion <NUM> and the venting guide <NUM> are further described with relation to <FIG> showing a detail of the pneumatic valve <NUM> depicted in <FIG>.

The exhaust portion <NUM> comprises an exhaust cavity <NUM> formed by the housing <NUM>. The exhaust cavity <NUM> is arranged between the second valve cavity <NUM> and an outer opening <NUM> of the housing <NUM>. The internal channel <NUM> opens into the exhaust cavity <NUM>. If the venting guide <NUM> were not part of the pneumatic valve <NUM>, the outer opening <NUM> would form an opening of the pneumatic valve <NUM> to the environment. However, as shown in <FIG>, the venting guide <NUM> is connected to the guide element <NUM> of the pneumatic valve <NUM>. An attachment portion <NUM> having connection elements <NUM> is provided on the guide element <NUM> at an end portion of the internal channel <NUM>. In this embodiment, the connection elements <NUM> are formed as circumferential saw tooth shaped ridges, which are engaged by complementary connection elements <NUM> of the venting guide <NUM> formed as snap hooks <NUM>.

The pneumatic valve <NUM> comprises a valve sealing surface <NUM>, which is formed on the guide element <NUM> in the depicted embodiment. In particular, the valve sealing surface <NUM> is an inner sealing face <NUM> formed on the internal channel <NUM>. To ensure the sealing connection between the venting guide <NUM> and the attachment portion <NUM>, a sealing element in the form of an O-ring <NUM> is arranged between the venting guide <NUM> and the sealing surface <NUM>. In this embodiment, the first sealing face <NUM> is formed by a step <NUM> of the internal channel <NUM>. When the complementary connection elements <NUM> engage the connection elements <NUM> of the attachment portion <NUM>, the venting guide <NUM> presses the O-ring <NUM> against the step <NUM> and thereby ensures a sealing connection of the venting guide <NUM> to the guide element <NUM>.

The venting guide <NUM> comprises a spout <NUM> and a support projection <NUM>. It partially extends out of the exhaust cavity <NUM> and away from the pneumatic valve <NUM>. The spout <NUM> is L-shaped. A first leg <NUM> of the spout <NUM> is adapted to be inserted in a hose (not shown) which can be clamped onto the spout <NUM> with a hose clamp (not shown). A spout end <NUM> on the first leg <NUM> comprises a circumferential ridge <NUM> preventing a hose clamp from sliding of the spout <NUM>. A first leg length L1 of the first leg <NUM> is greater than a corresponding second leg length L2 of the second leg <NUM>.

For guiding the pressurized air received from the exhaust portion <NUM> of the pneumatic valve <NUM>, the venting guide <NUM> comprises a venting channel <NUM>. A first venting channel portion <NUM> of the venting channel <NUM> extends in the first leg <NUM> while a second venting channel portion <NUM> intersecting the first venting channel portion <NUM> at an intersection <NUM> extends in the second leg <NUM> of the L-shaped spout <NUM>. In the shown embodiment and preferably the L-shape is bent in a single plane. A central axis of the first venting channel portion <NUM> and a central axis of the second venting channel portion <NUM> lie in a common plane.

In the embodiment shown in <FIG>, the first venting channel portion <NUM> intersects the second venting channel portion <NUM> at a <NUM>° leg angle α such that the venting channel portions <NUM>, <NUM> of the venting channel <NUM> extend perpendicular to each other from the intersection <NUM>. The venting channel portions <NUM>, <NUM> are formed as cylindrical bores in the spout <NUM>. One or both venting channel portions <NUM>, <NUM> may also have a non-cylindrical shape. For example the first venting channel portion <NUM> and/or the second venting channel portion <NUM> may have a rectangular, octagonal and/or oval cross-section.

A tapered end portion <NUM> of the first venting channel portion <NUM> extends beyond the intersection <NUM>. In this embodiment, only the tapered end portion <NUM> extends beyond intersection <NUM>. However, part of the first venting channel portion <NUM> may preferably extend beyond the intersection <NUM> as well. The tapered end portion <NUM> has a conical shape, in particular a circle cone shape. An opening angle ε of the tapered end portion <NUM> has a value of <NUM>°. The tapered end portion <NUM> is preferably formed by the tip of a drill bit, when the first venting channel portion <NUM> is drilled during manufacturing of the venting guide <NUM>. Manufacturing of the venting channel <NUM> is facilitated since no flat-bottomed hole needs to be provided for forming the first venting channel portion <NUM>.

Moreover, the tapered end portion <NUM> improves stability of the pneumatic valve <NUM>. During operation, pressurized air is discharged from the pneumatic valve <NUM> via the venting channel <NUM> of the venting guide <NUM>. Air flows from the internal channel <NUM> of the guide element <NUM> to the second venting channel portion <NUM>. At the intersection <NUM>, the air flow is redirected into the first venting channel portion <NUM> and towards the spout end <NUM>. A momentum of the airflow changes and the air exerts forces on the venting guide <NUM> at the intersection <NUM>. Moreover, a pressure drop occurs between the environment and the pneumatic valve <NUM> such that a pressure level in the venting channel <NUM> differs from a pressure level of the environment. This pressure differential also exerts forces on the venting guide <NUM>. The tapered end portion <NUM> evenly distributes the forces resulting from the pressure differential and from the momentum change of the airflow, such that non-symmetrical loads on the venting guide <NUM> are prevented. Thereby less stress is put on the complementary connection elements <NUM> of the venting guide <NUM> as well as the attachment portion <NUM>.

<FIG> depicts the venting guide <NUM> in a neutral position <NUM>. The first leg <NUM> of the L-shaped spout <NUM> laterally extends from the housing <NUM>. No external loads are provided on the spout <NUM> in the neutral position <NUM>. However, during assembly and or operation, loads are provided on the venting guide <NUM>, in particular on the spout <NUM>. During assembly, the venting guide <NUM> is pushed onto the guide element <NUM> such that the complementary connection elements <NUM> engage the attachment portion <NUM>. For engaging the connection elements <NUM> of the attachment portion <NUM>, the snap hooks <NUM> are pushed over the ridges of the attachment portion <NUM> (upwards with respect to <FIG>). While being pushed over the ridges of the attachment portion <NUM>, the snap hooks <NUM> are laterally deformed (horizontally with respect to <FIG>). For pushing the venting guide <NUM> onto the attachment portion <NUM>, a first assembly force F _A <NUM> is provided onto the venting guide <NUM>. The first assembly force F_A1 required for pushing the complementary connection elements <NUM> onto the attachment portion <NUM> is further increased by an annular spring <NUM>, biasing the snap hooks <NUM> inwards. A person assembling the pneumatic valve <NUM> or an assembly apparatus may provide the first assembly force F_A1 unevenly to the venting guide <NUM>, such that the venting guide <NUM> tilts relative to the guide element <NUM> (e.g. counter-clockwise with respect to <FIG>). Moreover, a hose or pipe (not shown in <FIG>) is pushed over the spout end <NUM> of spout <NUM> when the pneumatic valve <NUM> is installed in the vehicle <NUM>. This exerts a second assembly force F_A2 on the spout <NUM>. Due to the L-shape of the spout <NUM>, a tilting momentum results from the second assembly force F_A2. Moreover, during operation the hose or pipe may exert additional forces on the first leg <NUM> of the spout <NUM>. An exemplary operational force F_O is illustrated in <FIG>.

If those forces F_A1, F_A2, F_0 were not compensated as explained below, the venting guide <NUM> would excessively tilt relative to the attachment portion <NUM> which could lead to damages on the complementary connection elements <NUM> and/or the connection elements <NUM>. Moreover, a sealing connection between the venting guide <NUM> and the guide element <NUM> would not be ensured.

To prevent tilting of the venting guide <NUM> relative to the housing <NUM>, the venting guide <NUM> comprises a support projection <NUM>. The support projection <NUM> extends opposite the first leg <NUM> from a main venting guide body <NUM> of the venting guide <NUM>. The second leg <NUM> and the complementary connection elements <NUM> are located between the first leg <NUM> and the support projection <NUM> in a first direction D1. A central axis of the support projection <NUM> is substantially parallel to a central axis of the first leg <NUM>, which is particularly conceivable from <FIG>. In this embodiment, the support projection <NUM> and the first leg <NUM> of the spout <NUM> have a common central axis A_C. In the top view of <FIG>, the venting guide <NUM> is symmetrical with respect to this central axis A_C. The top view furthers shows, that the venting guide <NUM> comprises a total of ten snap hooks <NUM>. However, the venting guide may also comprise less than ten snap hooks <NUM>, preferably two, three, four, five, six, seven, eight, or nine, or more than ten snap hooks <NUM>, preferably eleven, twelve, thirteen, fourteen or fifteen.

In the embodiment shown in <FIG>, the support projection <NUM> has the shape of a shark fin. The shark fin shape facilitates assembly, since no sharp edges are projecting towards a person pushing the venting guide <NUM> onto the guide element <NUM>. The support projection <NUM> may also have any other shape. Preferably, the support projection <NUM> may have a rectangular cross-section in a side view (as shown in <FIG>). The support projection <NUM> is positioned adjacent to a contact region <NUM> of the housing <NUM>. The contact region <NUM> is preferably formed on the housing <NUM>. However, the contact region <NUM> may also be formed on other elements of the pneumatic valve <NUM>, for example on an adapter <NUM> described later with respect to <FIG>. The contact region <NUM> is provided on the housing <NUM> on the first housing side <NUM>. Since, the exhaust cavity <NUM> opens towards the first housing side <NUM>, the contact region <NUM> is adjacent to the exhaust cavity <NUM>. In this embodiment, a flat first contact surface <NUM> of the housing <NUM> forms the contact region <NUM>. A corresponding flat support surface <NUM> is arranged opposite the first contact surface <NUM> on the support projection <NUM>.

A gap <NUM> is formed between the first contact surface <NUM> of the contact region <NUM> and the support surface <NUM> of the support projection <NUM> when the venting guide <NUM> is in the neutral position <NUM>. The gap <NUM> reduces overall cost of the pneumatic valve <NUM>, since the venting guide <NUM> and the housing <NUM> can be machined with less precision. A gap width <NUM> of the gap <NUM> is small. If the venting guide <NUM> is tilted during assembly and/or operation due to forces F_A1, F_A2, F_O, the venting guide <NUM> slightly tilts with respect to the housing <NUM>. The gap <NUM> is thereby closed (the gap width <NUM> reduced to zero respectively), such that the support projection <NUM> abuts the contact region <NUM>. The support surface <NUM> of the support projection <NUM> then contacts the first contact surface <NUM> of the contact region <NUM>. Tilting forces provided on the venting guide <NUM> are transferred to the housing <NUM> such that excessive tilting of the venting guide <NUM> relative to the housing <NUM> is prevented. It shall be understood, that the support projection <NUM> allows a slight tilt of the venting guide <NUM> relative to the housing <NUM> in the shown embodiment. However, the gap width <NUM> may be chosen such that the relative tilt of the venting guide <NUM> relative to the housing <NUM> does not inhibit a sealing connection and that neither the complementary connection elements <NUM> nor the connection elements <NUM> are damaged. In other embodiments, the support projection <NUM> may abut the contact region <NUM> in the neutral position <NUM>.

The venting guide <NUM> further comprises reinforcement ribs <NUM> shown in <FIG>. The reinforcement ribs <NUM> extend from the support projection <NUM> at a rib angle β of <NUM>°. The ribs <NUM> prevent buckling and/or bending of the support projection <NUM>. The rib angel β is measured in a plane perpendicular to the second venting channel portion <NUM>. In a symmetry plane of the venting channel <NUM> (the plane shown in <FIG>), the ribs <NUM> are inclined at a secondary rib angle δ of about <NUM>°. The ribs <NUM> support the support projection <NUM>. The support projection <NUM> may therefore be formed as a thin rib and less material is required for manufacturing the support projection <NUM>. Preferably, the venting guide <NUM> is made from a plastic material, particularly preferred by injection molding. A preferred material of the venting guide <NUM> is Polyamid <NUM> (PA6 or Polycaprolactam). The support projection <NUM> and the ribs <NUM> are relatively thin, so that imperfections resulting from different solidifications rates during molding are prevented.

The ribs <NUM> are particularly helpful to prevent bending and or buckling of the support projection <NUM> if the venting guide <NUM> comprises an anti-rotation feature as shown in the alternative embodiment depicted in <FIG> showing only part of the housing <NUM>. The support projection <NUM> further comprises a protrusion <NUM> extending towards the contact region <NUM>. The support surface <NUM> of the support projection <NUM> is formed on the protrusion <NUM>. However, the support surface <NUM> may also be formed separate from the protrusion <NUM>. The protrusion <NUM> engages a slot <NUM> such that rotation of the venting guide <NUM> relative to the housing <NUM> of the pneumatic valve <NUM> around a rotational axis A_R is prevented. A rotation force provided to the venting guide <NUM> is transferred to the housing <NUM> via the protrusion <NUM>. The ribs <NUM> help transferring such a rotational load. However, it shall be noted that a venting guide <NUM> comprising an anti-rotation feature may also be formed without ribs <NUM>. In the embodiment shown in <FIG>, the slot <NUM> receiving the protrusion <NUM> is formed in the housing <NUM>. The rotational axis A_R preferably extends centrally through the complementary connection elements <NUM> and/or the second venting channel portion <NUM>. Together the protrusion <NUM> and the slot <NUM> prevent rotation of the venting guide <NUM>. The slot may be easily machined into the housing <NUM> of the pneumatic valve <NUM>. This provides a simple way to ensure a specific orientation of the first leg <NUM> of the spout <NUM> relative to the housing <NUM>.

However, providing the slot <NUM> in the housing <NUM> may not be practical in all cases. Preferably, the slot <NUM> may therefore be formed in an adapter <NUM> as shown in <FIG>. The adapter <NUM> is rotationally fixed to the housing <NUM>. For example, the adapter <NUM> may be glued and or screwed to the housing <NUM>. In the alternative embodiment shown in <FIG>, the support projection <NUM> engages the slot <NUM> such that no protrusion <NUM> is required or the support projection <NUM> in itself forms the protrusion <NUM> respectively. Preferably, also embodiments of the pneumatic valve <NUM> having an adapter <NUM> may comprise a protrusion <NUM> of the venting guide <NUM> extending form the support projection <NUM> into slot <NUM>. The adapter <NUM> may be formed from a plastic material. The functionality of the embodiments shown in <FIG> and <FIG> with regard to the anti-rotation feature are substantially the same. Rotational loads provided on the venting guide <NUM> are transferred to the housing <NUM> via the slot <NUM> such that the slot <NUM> inhibits rotation of the venting guide <NUM> around rotational axis A_R. The adapter <NUM> may be provided for different orientations of the first leg <NUM> of the spout <NUM> with respect to the housing <NUM>. Through this, the pneumatic valve <NUM> may be easily adapted to different vehicles or use cases.

Claim 1:
A pneumatic valve (<NUM>) for providing a working pressure (pB), comprising
a housing (<NUM>) having a first housing side (<NUM>);
a supply connection (<NUM>) for receiving a supply pressure (pS);
a working connection (<NUM>) for providing the working pressure (pB);
an exhaust portion (<NUM>) for discharging pressurized air from the pneumatic valve (<NUM>) located proximate to the first housing side (<NUM>),
an attachment portion (<NUM>);
a valve member (<NUM>) continuously slidable from an exhaust position (<NUM>) to a fully open position (<NUM>), wherein the working connection (<NUM>) is in fluid communication with the exhaust portion (<NUM>) when the valve member (<NUM>) is in the exhaust position (<NUM>), and wherein the working connection (<NUM>) is in fluid communication with the supply connection (<NUM>) and sealed from the exhaust portion (<NUM>) when the valve member (<NUM>) is in an at least partially open position, and
a venting guide (<NUM>), the venting guide (<NUM>) comprising a venting channel (<NUM>) and complementary connection elements (<NUM>) engaging the attachment portion (<NUM>)
the venting guide (<NUM>) comprising a spout (<NUM>) and a support projection (<NUM>), wherein the support projection (<NUM>) is positioned adjacent to a contact region (<NUM>) of the housing (<NUM>) provided on the first housing side (<NUM>) and configured to abut the contact region (<NUM>) to prevent tilting of the venting guide (<NUM>) relative to the housing (<NUM>).