Patent Description:
In such a system, in order to exchange the filter cartridge of a filter, it is necessary to isolate the filter from the filtration system, i. from the fluid line in which the filter is arranged.

For this purpose, it is known from filtration systems having two filters operating in parallel to provide an operating element movable from a default position where both filters operate in parallel to a first or to a second isolating position for isolating the first filter or the second filter from the filtration system, respectively.

A filtration system according to the preamble of claim <NUM>, where separate operating elements are provided for the two filters, which are interconnected by a mechanical blocking mechanism, is known from <CIT>.

A further filtration system with two filters is known from <CIT>.

Thereby, the filter cartridge of one filter can be exchanged while the other filter is still operative, such that the exchange can be done during the operation of the system, with the other filter doing all the filtering for the time that is required for the exchange.

If two such filter systems are used in parallel, each filter system may still be provided with an operating element to be able to exchange a filter cartridge of one filter while the other is operable.

The inventor of the present invention has however realized that simply duplicating existing filtration systems will lead to an increased risk of failure.

The object of the present invention is therefore to provide an improved filtration system.

This object is solved by a filtration system according to claim <NUM>. Preferred embodiments of the present invention are the subject matter of the dependent claims.

The present invention provides a filtration system comprising a plurality of filters, in particular oil or fuel filters, a first operating element movable from a default position to a least one isolating position for isolating at least one filter of a first group of filters from the filtration system and a second operating element movable from a default position to at least one isolating position for isolating at least one filter of a second group of filters from the filtration system. At least two filters are associated to each operating element, the operating element being configured to selectively isolate at least one first filter out of the at least two filters from the filtration system in a first isolating position and at least one second filter out of the at least two filters in a second isolating position. Further, the system comprises a mechanical blocking mechanism that is actuated by a movement of the first operating element out of its default position to block the second operating element in its default position and actuated by a movement of the second operating element out of its default position to block the first operating element in its default position.

Using two parallel filtration systems without the present invention, there is the risk that the operator is switching off two filters at the same time, with the risk to get too much flow through the remaining filters and then damage them and pollute the circuit.

Risk analysis has shown that the oil circuit could be polluted followed by a major engine failure in this case, i.e. if the operator is not respecting a correct sequence during filter cartridge replacement.

The safety when using two filtration systems would, without the present invention, therefore only rely on the operating manual and/or training of the operators, teaching them to respect some sequence during filter cartridge replacement that will avoid a parallel isolation of several filters.

The present invention therefore uses a mechanical blocking mechanism to eliminate this risk. The blocking mechanism is in particular designed to avoid a situation where both operating elements are moved to an isolating position, and therefore avoids a situation where two filters are isolated at the same time.

This system can be applied for different media, such as fuel or oil, and is not restricted to engines but can be used in any filtration system as soon as a plurality of filters are used.

In an embodiment of the present invention, in a default state of the filtration system, both operating elements are arranged in their respective default position.

According to the present invention, in the default position of an operating element, all the filters of the respective group of filters are connected to the filtration system.

Preferably, the operating element is configured to selectively isolate in each isolating position at least one out of the two filters associated to the operating element from the filtration system while keeping the at least one other filter out of the at least two filters operative and connected to the filtration system.

In an embodiment of the present invention, each filter is at least a duplex filter comprising two filter elements or filters arranged in parallel. In particular, the two filter elements or filters may be isolated from and connected to the filtration system by the operating element in parallel.

In particular, in such an embodiment, whenever the previous or the following definitions relate to at least one filter, the at least one filter may be formed by two filter elements or filters arranged in parallel. Further, whenever the previous or the following definitions relate to at least two filters, each of these at least two filters may be formed by two filter elements or filters arranged in parallel.

In an embodiment of the present invention, all the filters are arranged in parallel in a fluid duct of the filtration system when connected by the respective operating element to the filtration system.

In an embodiment of the present invention, the mechanical blocking mechanism comprises a blocking element operated by the first operating element to block the second operating element and a second blocking element operated by the second operating element to block the first operating element. In particular, the two blocking elements may be separate elements and/or can be moved independently from each other.

In an embodiment of the present invention, the blocking elements are slidably arranged on the filtration system to be moved from a default position to a blocking position.

In an embodiment of the present invention, the blocking elements may be plates, bars and/or rods extending longitudinally between the two operating elements.

In an embodiment of the present invention, the first blocking element and the second blocking element are arranged on top of each other and are preferably guided by one or more guide pins extending through linear slots in the blocking elements.

In an embodiment of the present invention, the first blocking element is operatively connected to a drive element of the first operating element and the second blocking element in operatively connected to a driving element of the second operating element.

In an embodiment of the present invention, each blocking element is operatively connected to the respective drive element in one of its end sections.

In an embodiment of the present invention, the drive elements of the operating elements each comprise a guide interacting with a pin of the respective blocking element, wherein the guide is preferably configured as a slot.

In an embodiment of the present invention, the drive elements are cut from a plate material.

In an embodiment of the present invention, the drive elements are fixedly connected to an axis of the operating element.

In an embodiment of the present invention, the operating elements are rotatable from the default position to the isolating position or positions.

In an embodiment of the present invention, the operating elements are rotatable from the default position in two opposite directions into the respective isolating positions.

In an embodiment of the present invention, a drive element for driving a blocking element is rotated by the rotation of the operating element.

In an embodiment of the present invention, a guide of the drive element is located at a first radial distance with respect to a rotation axis of the drive element in a default section and extends from the default section to an arcuate section where it extends at a second radial distance to the rotation axis of the drive element.

In an embodiment of the present invention, a pin of the blocking element is arranged in the default section of the guide when the operating element is in the default position and moves from the default section to the arcuate section once the operating element is rotated away from the default position to an isolating position, such that the blocking element is displaced by the difference in the radius of the guide in the default section to the arcuate section.

In an embodiment of the present invention, the guide has arcuate sections on both sides of the default section corresponding to the two isolating positions.

In an embodiment of the present invention, the operating elements comprise and/or operate a valve element that is rotated in a valve body for establishing at least one fluid communication through a fluid passage of the valve element in the default position and blocking the fluid communication in the isolating position.

In an embodiment of the present invention, the valve element establishes a first and a second fluid communication to an entry port and an exit port of each filter associated to the operating element in the default position and blocks the first and the second fluid communication to at least one filter in an isolating position.

In an embodiment of the present invention, the valve element is provided in or fixedly connected to a rotation axis of the operating element. In particular, the valve element may be provided by cut-outs provided in a rotation axis of the operating element.

In an embodiment of the present invention, a first blocking element has a blocking section that is movable into blocking engagement with a blocking section of the first operating element and a second blocking element has a blocking section that is movable into blocking engagement with a blocking section of the second operating element.

In an embodiment of the present invention, the blocking sections of the blocking elements are formed by respective end sections of the blocking elements.

In an embodiment of the present invention, the blocking sections of the operating elements are formed by respective recesses.

In an embodiment of the present invention, the blocking sections block rotational movement of the respective operating element when engaged with each other.

In an embodiment of the present invention, the blocking sections of the operating elements are formed in a plate element fixedly connected to the rotation axis of the operating element.

In an embodiment of the present invention, each operating element comprises a handle, in particular a lever, connected to the rotational axis of the operating element.

In an embodiment of the present invention, each filter or filter element comprises at least one filtration head housing and a replaceable filter cartridge.

In an embodiment of the present invention, the filtration system arranged in a fluid duct of an engine, in particular in an oil or fuel duct of the engine.

The present invention further comprises a machine comprising a fluid duct and a filtration system as described herein arranged in the fluid duct.

In an embodiment of the present invention, the machine is an engine, in particular an internal combustion engine.

In an embodiment of the present invention, the fluid duct is an oil or fuel duct.

In an embodiment of the present invention, the filtration system is arranged in a cooling and/or lubrication circuit of the machine, in particular of the engine.

The present invention will now be described in more detail with reference to figures and embodiments.

<FIG> shows an embodiment of a filtration system of the present invention. The filtration system comprises two groups A and B of filters arranged in parallel in a fluid pathway of the filtration system. Each group comprises at least a first filter <NUM>-<NUM>, <NUM>-<NUM> and a second filter <NUM>-<NUM>, <NUM>-<NUM>. In the embodiment, duplex filters are used. Each duplex filter comprises two filters or filter elements arranged and operated in parallel.

The first group A therefore comprises the first filter elements <NUM>-<NUM> forming a first duplex filter, and the second filters <NUM>-<NUM> forming a second duplex filter. The second group B comprises the first filters <NUM>-<NUM> forming a first duplex filter and the second filters <NUM>-<NUM> forming a second duplex filter. Instead of using duplex filters, the present invention could also be use single filters or filters having more than two filters arranged and operated in parallel.

Each group of filters A, B comprises an operating element <NUM>, <NUM> for selectively isolating either the first or the second filters from the filtration system. In a default position of the operating element, both the first and second filters are connected to the filtration system.

Therefore, in a first isolating position <NUM>, <NUM>, the respective first filters <NUM>-<NUM>, <NUM>-<NUM> are isolated. In a second isolating position <NUM>, <NUM>, the respective second filters <NUM>-<NUM>, <NUM>-<NUM> are isolated. In the default position <NUM>, <NUM>, all filters <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM> are connected.

Once a filter is isolated from the filtration system, the filter cartridge of the filter can be exchanged. The filtration system can be operated using the filters which are still connected.

Each of the operating elements is configured such that it only isolates, in each isolating position, either the first or the second filters from the filtration system, while the remaining second or first filters are still connected to the filtration system. This principle allows replacing a filter cartridge while the filtration system is working, because for each group of filters, at least one out of the first and the second filters will be connected to the filtration system and therefore working.

However, if the two operating elements operate independently from each other and both operating elements are in an isolating position, half of all the filters may be isolated. The remaining filtration power may therefore not be sufficient for maintaining a safe operation of the system.

The filtration system of the present invention therefore comprises a mechanical blocking mechanism that will avoid such a situation, because moving the one operating element out of its default position will actuate the blocking mechanism to block the other operating element in its default position.

<FIG> shows the five possible switching positions of the operating elements <NUM> and <NUM>. In situation a), both operating elements <NUM>, <NUM> are in their default position, such that all filters are connected to the filtration system. In situation b), the first operating element <NUM> is in its first isolating position <NUM>, isolating the first filters <NUM>-<NUM>. In situation c), the first operating element <NUM> is in its second isolating position <NUM>, isolating the second filters <NUM>-<NUM>. In situation d), the second operating element <NUM> is in its first isolating position <NUM>, isolating the first filters <NUM>-<NUM>. In situation e), the second operating element <NUM> is in its second isolating position <NUM>, isolating the second filters <NUM>-<NUM>. In situations b) and c), the second operating element <NUM> is in its default position <NUM>, while in situations d) and e), the first operating element <NUM> is in its default position <NUM>. Situations where both operating elements are in an isolating position are avoided by the mechanical blocking mechanism.

<FIG> shows some of the main components of an embodiment of the mechanical blocking mechanism. These components of the mechanical blocking mechanism also shown in <FIG> separately for groups A and B.

In particular, the mechanical blocking mechanism comprises a first blocking element <NUM> operated by the first operating element <NUM> to block the second operating element <NUM>, and a second blocking element <NUM> operated by the second operating element <NUM> to block the first operating element <NUM>.

The blocking elements <NUM>, <NUM> are respectively operated by a driving element <NUM>, <NUM>, fixedly connected to the respective operating element <NUM>, <NUM>. Each driving element <NUM>, <NUM> comprises a guide <NUM>, <NUM> cooperating with a respective pin <NUM>, <NUM> connected to the respective blocking element <NUM>, <NUM>.

The operating elements each have an axis of rotation <NUM>, <NUM>, and can be rotated from the default position <NUM>, <NUM> to the two isolating positions <NUM>, <NUM> and <NUM>, <NUM> respectively. In the embodiment, the isolating positions are arranged on opposite sides of the default position.

As can be seen from <FIG>, each operating element <NUM>, <NUM> operates, by this rotation, a valve element <NUM>, <NUM> to either open fluid passages or close fluid passages in a valve. In the embodiment, the valve element <NUM> is integrated into the axis of each operating element. Section <NUM>, <NUM> separates an inlet passage of the valve from an outlet passage of the valve, which are both closed and opened by each valve element <NUM>, <NUM>.

Once an operating element <NUM>, <NUM> is rotated, the corresponding drive element <NUM>, <NUM> will equally rotate, such that the guide will be displaced in a rotational movement. Because the distance of the guide <NUM>, <NUM> to the axis of the respective operating element varies along the extension of the guide, the respective pin <NUM>, <NUM> slidably engaged within the respective guide <NUM>, <NUM> will be displaced by such a rotation.

In particular, both blocking elements <NUM>, <NUM> are linearly movable from a default position to a blocking position. In particular, guide pins <NUM> engage with long holes <NUM>, <NUM> of the blocking elements to allow a sliding movement of each blocking element along a linear path.

Therefore, the guide pins <NUM>, <NUM> connected to the blocking elements <NUM>, <NUM> will displace the blocking elements, depending on the position of the drive element <NUM>, <NUM>, along this linear direction.

The blocking elements are arranged to extend from the respective drive element that will operate the blocking element to a counter element of the other operating element to engage with the counter element in their blocking position.

In the embodiment, the blocking elements are plate elements or bars extending between the two operating elements.

In the embodiment, the two blocking elements are placed on top of each other, with the same guiding pins <NUM> reaching through guide holes <NUM>, <NUM> in both blocking elements.

Further, the blocking elements are arranged to extend along a line connecting the two axes <NUM>, <NUM> of the two operating elements, <NUM>, <NUM>.

At least one of the blocking elements <NUM>, <NUM> has a slot <NUM> arranged in the end section opposite the pin <NUM>, in order to allow the pin <NUM> of the other blocking element to extend through the blocking element <NUM> in order to engage with the respective drive element <NUM>.

As shown in <FIG>, each guide <NUM>, <NUM> has a first guide section <NUM>', <NUM>' in which the respective pin <NUM>, <NUM> is arranged if the operating element in in its default position. Further, second guide sections <NUM>", <NUM>" extend on both sides of the first guide section <NUM>', <NUM>'. Once the operating element is moved from its default position in the directions of one of its isolating positions, the pin <NUM>, <NUM> will move from the first guide section <NUM>', <NUM>' into one of the second guide sections <NUM>", <NUM>".

The second guide sections <NUM>", <NUM>" are arcuate sections extending at a radius with respect to the axis of the respective operating element which is larger than the distance of the first guide sections <NUM>', <NUM>' to the respective axis. Thereby, once the respective operating element is moved from the default position in the direction of an isolating position, the respective pin <NUM>, <NUM> and therefore the blocking element <NUM>, <NUM> will be moved away from the axis of rotation of the operating element <NUM>, <NUM> and therefore in the direction of the other operating element to engage with the counter element.

The above described configuration of the two blocking elements arranged on top of each other, with the pin <NUM> of the first blocking element <NUM> reaching trough a slit <NUM> in the end section of the second blocking element <NUM> to engage with the guide <NUM> of the drive element <NUM> of the first operating element, is shown in <FIG> also shows the valve elements <NUM> in the respective default positions opening flow channels to the respective filters.

Each operating element <NUM>, <NUM> has a handle <NUM>, <NUM> for rotating the operating element. In the embodiment, the handle is a lever.

<FIG> shows the two possible configurations between a blocking element and its respective counter element.

In particular, the ends of the blocking elements <NUM>, <NUM> opposite the respective pins <NUM>, <NUM> have blocking edges <NUM>, <NUM> that can be engaged with a recess <NUM>, <NUM> of the respective counter element <NUM>, <NUM>. The recess <NUM>, <NUM> therefore forms a blocking section engaging with the blocking element.

<FIG> shows on the left hand side a situation where group A, i.e. the first operating element <NUM>, is free to rotate because the second blocking element <NUM> comprising the blocking edges <NUM> is not engaged with the recess <NUM> of the counter element <NUM>, with a distance d remaining between the sides <NUM> of the recess <NUM> and the blocking edges <NUM>. On the right hand side, <FIG> shows the situation where group B, i.e. the second operating element <NUM>, is blocked from rotating because the first blocking element <NUM> engages with the corresponding counter element <NUM>. In particular, the blocking edges <NUM> of the first blocking element <NUM> are engaged into the recess <NUM>, with an interference e between the blocking edges <NUM> and the sides <NUM> of the recess <NUM> blocking a rotational movement. The sides <NUM>, <NUM> of the recesses <NUM>, <NUM> therefore form counter-blocking edges cooperating with the blocking edges of the blocking elements.

The respective counter elements <NUM>, <NUM> are fixedly attached to the respective operating elements <NUM>, <NUM> to block the rotational movement of the respective operating element <NUM>, <NUM> when engaged with the blocking element.

<FIG> now shows different switching positions of the filtration system and the respective positions of the blocking elements and their counter elements.

<FIG> shows situation a) of <FIG>, i.e. where both operating elements are in their default position. Therefore, the pins <NUM> and <NUM> are arranged in the respective default sections <NUM>', <NUM>' of the guides such that the blocking element are in their default positions, with the blocking edges <NUM>, <NUM> arranged with a distance d to the sides <NUM>, <NUM> of the recesses <NUM>, <NUM>, such that both operating elements are free to rotate.

<FIG> shows situation b) of <FIG>, with the first operating element in its first isolation position isolating the first filters <NUM> - <NUM>. Thereby, pin <NUM> of the first blocking element <NUM> is in the isolating section <NUM>" of the guide <NUM>, moving the blocking element <NUM> in the direction of the second operating element <NUM>. Thereby, the blocking edges <NUM> engage into the recess <NUM>, with an interference e between the blocking edges <NUM> of the blocking element <NUM> and the sides <NUM> of the recess <NUM> blocking rotation of the counter element <NUM>. Thereby, group B and therefore the second operating element is blocked from rotating.

<FIG> shows the corresponding situation for group A or the first operating element <NUM> being blocked by the second operating <NUM> being in the first isolating position, corresponding to situation d) of <FIG>.

The configuration of the valve element <NUM> is shown in <FIG> for the first operating element <NUM> or group A. The configuration of the second operating element <NUM> and group B is the same.

The valve has two sections, one for the inlets to the filters, one or the outlets. The sections for the inlets correspond to the dirty oil section <NUM>, the sections for the outlets to the clean oil sections <NUM> shown in <FIG>. The two sections are arranged next to each other along the axial direction of the valve element, and separated by a separating block <NUM>. In each section, the valve element <NUM> will open a respective flow path from a fluid duct <NUM>, <NUM> of the filtration system to the corresponding inlets or outlets of all the filters associated to the respective valve. By rotating the valve element in a first direction, the inlets and the outlets of the first filters will be blocked from the respective fluid paths of the filtration system, while the second filters will still be connected. A rotation in the second direction will block the inlets and outlets of the second filters while leaving the inlets and outlets of the first filters connected.

As can be seen from <FIG>, the filters <NUM> - <NUM> of the first duplex filter are connected in parallel both on the outlet and on the inlet side to the valve. The same is true for the filters <NUM> - <NUM> of the second duplex filter. Instead of using duplex filters, single filters could equally be used.

As shown in <FIG>, each filter has a filter head housing <NUM> comprising the connections to the respective valve, and a filter cartridge housing <NUM> connected to the filter head housing <NUM>. Thereby, if the filter is isolated from the filtration system, the filter cartridge housing <NUM> can be removed, the filter cartridge replaced and the filter cartridge housing installed again.

The filtration system of the present invention can for example be used for internal combustion engines, in particular as a filtration system of the lubricating system.

Claim 1:
A filtration system comprising
a plurality of filters (<NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>), in particular oil or fuel filters,
a first operating element (<NUM>) movable from a default position (<NUM>) to a least one isolating position (<NUM>, <NUM>) for isolating at least one filter (<NUM>-<NUM>, <NUM>-<NUM>) of a first group (A) of filters from the filtration system,
a second operating element (<NUM>) movable from a default position (<NUM>) to at least one isolating position (<NUM>, <NUM>) for isolating at least one filter (<NUM>-<NUM>, <NUM>-<NUM>) of a second group (B) of filters from the filtration system, and
a mechanical blocking mechanism that is actuated by a movement of the first operating element (<NUM>) out of its default position (<NUM>) to block the second operating element (<NUM>) in its default position (<NUM>) and actuated by a movement of the second operating element (<NUM>) out of its default position (<NUM>) to block the first operating element (<NUM>) in its default position (<NUM>),
wherein in the default position (<NUM>, <NUM>) of the first and second operating element (<NUM>, <NUM>), all the filters of the respective group of filters (A,B) are connected to the filtration system,
characterized in that
at least two filters are associated to each operating element (<NUM>, <NUM>), the operating element (<NUM>, <NUM>) being configured to selectively isolate at least one first filter (<NUM>-<NUM>, <NUM>-<NUM>) out of the at least two filters from the filtration system in a first isolating position (<NUM>, <NUM>) and at least one second filter (<NUM>-<NUM>, <NUM>-<NUM>) out of the at least two filters in a second isolating position (<NUM>, <NUM>).