Patent Description:
Further, the present invention relates to a desiccant cartridge comprising an interface as mentioned above.

And additionally, the present intention relates to an air control device for a vehicle, especially a utility vehicle, comprising a desiccant cartridge as mentioned above.

In practice, it is known that in the field of vehicles and especially utility or commercial vehicles, usually pneumatic systems are used for brakes, suspension and other auxiliary systems, wherein the distribution of the air is handled by an electronic air control device or a multi-circuit protection valve that can divide the air provided by a compressor or the like, and handles the different opening and closing pressures, the pressure limitation of each circuits, and the circuit protection.

Before the pressurized air may be controlled this way, an important measure is to dry this air (as it still contains humidity of the atmosphere) provided by the compressor. This drying procedure is established by a desiccant or air dryer cartridge being arranged between the compressor and the air control device such that dried and de-oiled air is provided to the multi-circuit protection valve.

Such conventional desiccant cartridges are already known in the prior art.

<CIT> shows an air-drying device having a connection housing on which a cap-shaped container is mounted, which accommodates a drying agent cartridge. For ease of changing the drying agent cartridge, a clamping bracket is used, which is swivellably mounted on the housing and can be swivelled over the container and fixed there.

<CIT> discloses an air dryer control system in which the compressed air output of a compressor is dried by one of two air dryers connected in parallel. The purging and drying cycles of the air dryers are alternated by a timing and relay device.

<CIT> discloses a shuttle valve for a gas drying system that cleans and dries a stream of unpurified pressurized gas received from a source thereof and supplied to a pneumatic system that uses such a purified pressurized air. The valve includes a housing that connects a drying assembly to a structure that conveys the unpurified pressurized air to the drying assembly.

<CIT> shows an air dryer cartridge for a compressed air treatment system of a vehicle, in particular of a commercial vehicle, comprising a spring cover and a carrier element, which together define a volume of the air dryer cartridge in the assembled state of the air dryer cartridge, wherein a desiccant box arranged inside the volume and filled with a desiccant is provided.

<CIT> relates to a twin tower air drying system for cleaning and drying a stream of unpurified pressurized air including a centrifugal separator having a baffle horizontally disposed therein to generally separate the centrifugal chamber into an upper sub-chamber and a lower sub-chamber; a pair of cavities each containing desiccant media and a purge tube with a flapper valve thereover to close and restrict flow of air through the purge tube when air is flowing upwardly through the cavity, and to open and promote air flow through the purge tube when air is flowing downwardly through the cavity.

<CIT> discloses a twin tower gas drying system for cleaning and drying a stream of unpurified pressurized gas received from a source thereof for use of a pneumatic system. The drying system includes a manifold block provided with the plurality of ports. A separator and sump are connected to such a block and to one of the ports for initially separating moisture and particulates from such stream of unpurified gas, and for directing the remainder of the stream to the one port in the block.

<CIT> discloses a bayonet fixation mechanism for an air dryer cartridge.

<CIT> discloses a depressurization screw with an axial bore hole and a radial bore hole, which a connected to each other a where the bore holes as depressurization channel.

<CIT> discloses a fixation and securing element for a pressurized air system.

<CIT> and <CIT> describe a radial sealing element for an air dryer cartridge of a depressurization system. <CIT> describes a fuel filter bayonet-style cartridge attachment.

Basically, according to the prior art, the fixing between the desiccant cartridge and air control device accommodating said cartridge is often solved by one central threaded portion in combination with a bayonet locking. Thus, a large number of components and construction space together with a high assembling effort are necessary.

It is therefore an object of the present invention to improve a positioning and mounting interface between a desiccant cartridge and an air control device as mentioned above, in particular in that this interface is simplified in structural and functional terms and that the desiccant cartridge is easier to mount to the air control device.

This object is solved according to the present invention with a positioning and mounting interface according to the features of claim <NUM>. Accordingly, a positioning and mounting interface for positioning a desiccant cartridge in and mounting to an air control device of a vehicle, especially a utility vehicle, is provided. The interface comprises an annular portion having at least one recess for engaging with at least one pin of a receiving portion of the air control device.

The invention is based on the basic idea that a positioning and mounting interface for positioning a desiccant cartridge in and mounting to an air control device of a vehicle, especially a utility vehicle, is provided which allows for an easy tactile assembly in which the correct or proper positioning and (final) engagement for the mounting of the cartridge into the air control device is controlled by means of haptic feedback. Since neither the interface nor the pins of the receiving portion of the air control device are visible to the user after the cartridge has been placed onto the receiving portion, it is necessary to rotate the cartridge around its vertical axis to reach the correct mounting position. The structure of the interface, comprising inter alia a special rib geometry, and the arrangement of the pins ensure that the mounting position is reached within a maximum of <NUM> degrees of rotation and that there is only one possible mounting position. Once this mounting position is reached, the pins of the receiving portion engage into the recesses formed in the annular portion and the user can push down the cartridge into its final assembly position within the receiving portion. In a subsequent assembly step, the cartridge is then secured with a bayonet ring at its outer circumference to the air control device.

The annular portion, which preferably comprises said special rib geometry, protrudes or projects from the plane of the interface, as do the pins from the receiving portion of the air control device, whereby the annular portion rests on the pins after the cartridge is placed onto the receiving portion. The cartridge is additionally supported on the inner circumference of the receiving portion. As a result, the cartridge is initially inclined or tilted relative to the receiving portion, i.e. after placement but before full rotation, unless the final assembly position is not reached directly with placement.

The shape of the interface according to the present invention requires less material than the previously used interfaces having a fully formed and flat surface and is easier to manufacture.

In a possible embodiment of the present invention, the annular portion has at least two recesses for engaging with at least two pins of the receiving portion of the air control device.

It may be further provided that the interface further comprises a central annular bushing for engaging with a central nozzle of the receiving portion of the air control device, wherein the central annular bushing is arranged inside the annular portion.

The engaging or connection between the central annular bushing and the central nozzle, which is preferably sealed on the outside by an O-ring, ensures that the compressed air to be dried is conducted exclusively through the desiccant.

It is also conceivable that the annular portion and the annular bushing are spaced apart.

In order to be able to manufacture the annular portion and the central annular bushing in a more material-optimised way, it is advantageous if they are formed separately on the positioning and mounting interface.

Moreover, it is conceivable that the interface further comprises at least two pairs of supporting pins arranged radially outside the annular portion.

By this pairs of supporting pins the cartridge is supported against the inner circumference of the receiving portion during rotating. In addition, as the supporting pins may stay visible when the cartridge is placed onto the receiving portion, they may be used as additional positioning markers.

Furthermore, it is possible that each two recesses and/or each two pins enclose an angle less than <NUM> degrees.

If e.g. the angle between two pins is less than <NUM> degrees in relation to the centre of the receiving portion, it is ensured that the corresponding pins engage stably in the corresponding recesses when the mounting position is reached, i.e. in particular without any tilting of the cartridge around a shared axis formed by the pins and recesses in case these are arranged along this shared axis. Thus, a most likely unstable mounting position occurs if exactly two recesses and correspondingly two pins enclose a degree of <NUM> degrees.

It is also possible that a cross section of the at least one recess is formed at least partially as circular ring sector.

It should be understood that a ring sector is a cut from a ring, which is bordered by two straight lines from its centre. However, other recess shapes are possible and the shape of each recess may be different to the others.

It also conceivable that an inside radius of a first recess is greater than an inside radius of a second recess.

The offset of the recesses in relation to each other in the radial direction ensures that there is only one position for the corresponding pins of the receiving portion to engage in the recesses.

Moreover, it is possible that the first recess is open at the radially outward edge and the second recess has a fully closed edge.

This allows the corresponding pin to slide radially inwards into the first recess once the proper mounting position has been reached by rotation, thereby raising the cartridge from the tilted state relative to a plane of the receiving portion. At the same time, the other pin engages in the second recess with a fully closed edge in an approximately perpendicular engaging direction thereto.

It may further be provided that the annular portion comprises a plurality of ribs arranged transversely to the circumferential direction of the annular portion, wherein the plurality of ribs is preferably spaced equidistantly from each other.

In general, a corresponding part of the ribs of the annular ring rests on the pins when the desiccant cartridge is placed. During rotation, the heads or upper portions of the pins slide over the plurality of ribs, providing the user with tactile feedback regarding the progress of rotation. In addition, a rib geometry requires less material compared to a full body geometry.

It is further conceivable that the at least two pairs of supporting pins are arranged at the outer circumference of the interface contacting the inner circumference of the receiving portion of the air control device until the desiccant cartridge is positioned, wherein the supporting pins of each pair are spaced from each other enclosing an angle.

The desiccant cartridge is thus supported laterally during positioning, in particular rotating, into the receiving portion. Preferably, there is no contact between the supporting pins and the inner circumference of the receiving portion when the cartridge is fully mounted.

It may further be provided that the angle enclosed by a pair of first supporting pins is greater than the angle enclosed by a pair of second supporting pins, wherein preferably both angles are less than <NUM> degrees.

It is also possible that the first supporting pins and the second supporting pins are each symmetrical to the same axis, wherein the first supporting pins and the second supporting pins are arranged at opposite portions of the outer circumference of the interface.

It may further be provided that the interface further comprises a sieve portion arranged inside the annular bushing, wherein the sieve portion is permeable for pressurized air.

Coarser dirt particles can be sieved out of the pressurized air by an upstream sieve before the pressurized air flows through the desiccant.

It is further possible that the interface further comprises at least one outlet for a check valve arranged outside the annular portion.

The object of the present invention can further be solved by a desiccant cartridge comprising a housing and a cartridge insert having a positioning and mounting interface as described above, wherein the housing is attached to the cartridge insert.

The object of the present invention can further be solved by an air control device for a vehicle, especially a utility vehicle, comprising a receiving portion, a bayonet ring, and a desiccant cartridge as mentioned before which is mounted into the receiving portion and secured to the air control device by the bayonet ring.

Further details and advantages of the present invention shall now be disclosed in an embodiment according to the invention in connection with the drawing.

<FIG> shows a sectional perspective view of an embodiment of a desiccant cartridge <NUM> according to the present invention mounted to a receiving portion <NUM> of an embodiment of an air control device <NUM> according to the present invention.

The desiccant cartridge <NUM> comprises a housing <NUM> and a cartridge insert <NUM>.

The desiccant cartridge <NUM> is secured to the receiving portion by a bayonet ring <NUM> which engages the housing <NUM> of the desiccant cartridge <NUM>.

The housing <NUM> comprises a spring cover <NUM> and a spring <NUM>.

The cartridge insert <NUM> comprises a container <NUM> which contains the desiccant <NUM>.

The container <NUM> includes at the top a desiccant cover <NUM> having a top sieve <NUM>, and at the bottom a positioning and mounting interface <NUM>.

The spring <NUM> is arranged between the spring cover <NUM> and the desiccant cover <NUM>.

The cartridge insert <NUM> is laterally surrounded by a coalescing filter <NUM> which is hold in place by filter retainers <NUM>. Accordingly, the coalescing filter <NUM> is arranged between the cartridge insert <NUM> and the housing <NUM>.

A first O-ring <NUM> is placed between the container <NUM> and the upper edge of the receiving portion <NUM> to seal it.

The positioning and mounting interface <NUM> comprises supporting pins <NUM>, which are arranged at the outer circumference of the positioning and mounting interface <NUM>, an annular portion <NUM>, and a central annular bushing <NUM>.

The annular portion <NUM> comprises a first recess <NUM>, which is open at the radially outward edge, and a second recess <NUM> having a fully closed edge.

The receiving portion <NUM> comprises a first pin <NUM>, a second pin <NUM>, and a central nozzle <NUM>.

The first pin <NUM> is partially accommodated in the first recess <NUM>, and the second pin <NUM> is partially accommodated in the second recess <NUM>.

A second O-ring <NUM> is arranged between the central annular bushing <NUM> of the positioning and mounting interface <NUM> and the central nozzle <NUM> of the receiving portion <NUM>.

The fact that the first recess <NUM> does not have an outward boundary allows the first pin <NUM> to slide into the first recess <NUM> from the outside during rotation.

The positioning and mounting interface <NUM> further comprises a bottom sieve portion <NUM> which is arranged centrally and is located above the central nozzle <NUM> in the assembled state of the air control device <NUM>.

The supporting pins <NUM> support the desiccant cartridge <NUM> against the inner circumference of the receiving portion <NUM> during the positioning procedure.

The desiccant <NUM> absorbs the moisture of the compressed air that passes through it in order to dry it.

The coalescing filter <NUM>, which comprises fibrous or wire mesh or fabric, filters oil and/or dirt particles from the air flowing through it.

The spring <NUM> damps the movement of the container <NUM> when the container <NUM> is deflected in the vertical direction referred to <FIG>.

It can further be derived from <FIG> that the pins <NUM>, <NUM> project more upwards from the receiving portion200 than the central nozzle <NUM>. In other words, the pins <NUM>, <NUM> are higher than the central nozzle <NUM>. Hence, the desiccant cartridge <NUM> is slightly tilted to the plane of the receiving portion <NUM>, when put on top of it, since the annular ring <NUM> rests on the pins <NUM>, <NUM> before a sufficient rotation allows them to engage in the recesses <NUM>, <NUM>.

In <FIG>, a partial sectional view in a different section plane of the embodiment of the desiccant cartridge <NUM> of <FIG> is presented.

The cartridge insert <NUM> further comprises at least one check valve <NUM> whose outlet is formed within the positioning and mounting interface <NUM> between the annular portion <NUM> and the outer circumference of the positioning and mounting interface <NUM>.

Furthermore, in the view of <FIG>, a further O-ring <NUM> is visible sealing the space between the housing <NUM> and the cartridge insert <NUM> from the environment.

Additionally, the different levels of protruding or projecting of the elements of the positioning and mounting interface <NUM> are shown in the view of <FIG>. Referring to a common starting level SL in <FIG>, the annular ring <NUM> protrudes downwards by a height h<NUM>, the supporting pins <NUM> protrude downwards by a height h<NUM>, and the central annular bushing <NUM> protrudes by a height h<NUM>. In this respect, the following applies to the heights: h<NUM> < h<NUM> < h<NUM>. But it should be understood that other heights including other ratios between the heights are possible.

<FIG> shows a top view of the receiving portion <NUM>, while <FIG> shows a sectional perspective view of the receiving portion <NUM>.

In <FIG>, it can be seen that the first pin <NUM> and the second pin <NUM> are arranged on a common circular ring and enclose an angle of less than <NUM> degrees. Both pins <NUM>, <NUM> are higher than the central nozzle <NUM>, but do not protrude beyond the outer edge of the receiving portion <NUM>, as can be derived from <FIG>.

In <FIG>, a view of the bottom side of a prior art embodiment of a positioning and mounting interface <NUM> is presented.

The prior art positioning and mounting interface <NUM> comprises a protruding circular portion <NUM> having a plane surface <NUM>. Within the plane surface <NUM> a first recess <NUM> and a second recess <NUM> are formed, wherein the first recess <NUM> is slightly offset radially outwards in comparison to the position of the second recess <NUM>. Furthermore, the first recess <NUM> is greater than the second recess <NUM>.

Within the plane surface <NUM> of the circular portion <NUM>, a structure <NUM> of circularly arranged openings is formed to make it easier for a user via a haptic feedback to guide the pins <NUM>, <NUM> of the receiving portion <NUM> into the recesses <NUM>, <NUM> during assembly rotation.

In comparison to the prior art interface <NUM> of <FIG>, <FIG> presents a bottom side view of the positioning and mounting interface <NUM> according to the present invention, wherein the positioning and mounting interface <NUM> comprises three outlets of the corresponding check valves <NUM>.

The annular ring <NUM> is formed by a plurality of ribs <NUM> which are spaced equidistantly to each other. These ribs <NUM> assist the user during the assembly rotation by giving him a tactile response regarding the amount of rotation. The pins <NUM>, <NUM> slide over the ribs <NUM> with the spaces between the ribs <NUM> being perceptible to the user during rotation.

The first recess <NUM> and the second recess <NUM> are formed as circular ring sectors, wherein the inside radius r<NUM> of the first recess <NUM> is greater than the inside radius r<NUM> of the second recess <NUM>.

Because the first recess <NUM> has no outer edge, the first pin <NUM> can slide into the first recess <NUM> during rotation of the desiccant cartridge <NUM>, causing the desiccant cartridge <NUM> to straighten up, i.e. the vertical axis of the desiccant cartridge <NUM> is perpendicular to the base plane of the receiving portion <NUM>.

In <FIG>, a sectional top view of the embodiment of the desiccant cartridge <NUM> mounted to the receiving portion <NUM> of the embodiment of the air control device <NUM> of <FIG> is shown.

Of the desiccant cartridge <NUM> just a lower portion of the positioning and mounting interface <NUM> is presented to better understand the engaging and lateral support.

Until the desiccant cartridge <NUM> is not in the proper mounting position, the ribs <NUM> of the annular portion <NUM> rest on the first and the second pin <NUM>, <NUM> of the receiving portion <NUM>, and the desiccant cartridge <NUM> is laterally supported by the two supporting pin pairs 138a, 138b against the inner circumference of the receiving portion <NUM>.

The first pair of supporting pins 138a encloses an angle α, while the second pair of supporting pins 138b encloses an angle β which is less than the angle α. Both angles α, β are preferably smaller than <NUM> degrees.

The two pairs of supporting pins 138a, 138b are arranged at opposite portions of the positioning and mounting interface <NUM>. Furthermore, the supporting pins of each pair 138a, 138b are symmetrically arranged to a mirror axis MA.

Claim 1:
A positioning and mounting interface (<NUM>) for positioning a desiccant cartridge (<NUM>) in and mounting to an air control device (<NUM>) of a vehicle, especially a utility vehicle, wherein the interface (<NUM>) comprises an annular portion (<NUM>) having at least one recess (<NUM>, <NUM>) for engaging with at least one pin (<NUM>, <NUM>) of a receiving portion (<NUM>) of the air control device (<NUM>), and characterized in that the interface (<NUM>) further comprises a central annular bushing (<NUM>) for engaging with a central nozzle (<NUM>) of the receiving portion (<NUM>) of the air control device (<NUM>), wherein the central annular bushing (<NUM>) is arranged inside the annular portion (<NUM>).