CN108568144B

CN108568144B - Back flushing filter

Info

Publication number: CN108568144B
Application number: CN201710136940.7A
Authority: CN
Inventors: W.黑金
Original assignee: Hans Sasserath GmbH and Co KG
Current assignee: Hans Sasserath GmbH and Co KG
Priority date: 2017-03-09
Filing date: 2017-03-09
Publication date: 2021-11-19
Anticipated expiration: 2037-03-09
Also published as: CN108568144A

Abstract

The invention relates to a back flush filter, in particular to a back flush filter assembly, comprising: a fitting having an inlet and an outlet; a filter cup connected to the fitting and having a discharge end; a substantially cylindrical filter element arranged in flow relation between the inlet and the outlet, which filter element is arranged in the filter cup in such a way that an annular space is formed between the filter element and the filter cup; a discharge end-closing member fixedly connected to the filter element; and channel walls extending in the axial direction, which channel walls are molded in pairs to the inner wall section of the filter cup and extend over the entire height of the filter element and form one or more channels, which channels are closed upwards and in the peripheral direction, open downwards towards the discharge end and inwards in the radial direction.

Description

Back flushing filter

Technical Field

The invention relates to a back flush filter assembly comprising:

(a) a fitting having an inlet and an outlet;

(b) a filter cup connected to the fitting having a discharge end;

(c) a substantially cylindrical filter element arranged in flow relation between an inlet and an outlet, the filter element being arranged in the filter cup such that an annular space is formed between the filter element and the filter cup;

(d) a discharge end-closure member fixedly connected to the filter element; and

(e) channel walls extending in the axial direction, which channel walls are molded (angelformer) in pairs at the inner wall portion of the filter cup and extend over the entire height of the filter element and form one or more channels, which channels are closed upwards and in the peripheral direction, open downwards towards the discharge end and inwards in the radial direction;

wherein the content of the first and second substances,

(f) the filter assembly is switchable from a first state (in which water flows from the inlet through the filter element to the outlet) into at least one second state in which the water flows from the inlet through the filter element in the opposite direction to the discharge end with the discharge valve open.

Such a filter assembly is known as a back flush filter. The flow flows through the filter in the operating state. Where the dirt particles are trapped. Over time, the filter becomes clogged. And then reversing the flow through the filter. The water flows in the opposite direction through the filter to the discharge end and carries the dirt particles away there. In this way the filter is cleaned by back flushing.

Such assemblies are used in domestic water installation devices. The drinking water provided by a supply line for a building or a single water tap (Zapfstelle) is filtered.

Background

Back-flush filter assemblies are known in a variety of ways. For maintenance of the filter, a barrier is provided before the assembly. For back flushing, the water flow is guided through the filter in the opposite direction by means of a suitable valve switching (Ventilschaltung). In this case, the particles adhering to the filter are separated and removed via the discharge end.

DE 10200500009 a1 discloses a filter assembly with an integrated leakage protection. The assembly uses a back flush filter and a turbine disposed immediately before the back flush filter. Each water flow through the filter is detected (erfasst) and evaluated with the turbine.

DE 102009006443 a1 discloses a pressure reducer filter assembly. The pressure reducer is completely enclosed in the inner space of the filter without an access opening from the outside. The filter includes a filter element in a filter sleeve disposed in a filter cup. A rotatable channel element is arranged between the pressure reducer and the filter element. The channel element is provided with wings. A discharge end is provided at the bottom of the filter cup. If the discharge end is opened for back flushing, the flow is directed to the wing (angelstr mt) and the channel element is rotated. The assembly is complex in construction and susceptible to impact (anf ä llig).

Chinese patent application with publication number CN 102068519 discloses a filter assembly in which channels are provided, which are connected at the lower end with a discharge end. If the discharge end is opened, the water flows down and creates an attractive force in the channel. The channel is moved along the filter element by rotation of the channel element, thereby sucking particles away from the filter surface. The known assemblies are complex in construction and expensive to manufacture.

CN 106178647 a discloses a filter assembly with a filter cup having a channel extending in axial direction at an inner wall portion of the filter cup. The ring at the bottom of the filter element interacts with the channel wall in such a way that the ring follows the rotational movement of the filter cup. An asymmetric protrusion is provided on an inner wall portion of the ring. The spindle with the guide part closing the discharge end and with the projection extending in the radial direction forms a ratchet mechanism with an asymmetrical projection on the inner wall section of the ring. The asymmetrical projections are configured such that, if the spindle is in the upper region, the projections at the spindle ride over the asymmetrical projections when the filter cup and the ring are rotated in a first direction and the projections at the spindle entrain the asymmetrical projections when the filter cup and the ring are rotated in a second, opposite direction. In the lower region, it makes the described sweeping or entrainment in the opposite direction. Instead of a ball valve (Kugelhahns), the assembly uses a lead screw (gewendespin) in the bottom of the filter element. By rotation of the filter cup, the ring also rotates. In this case, the projection strikes against a projection at the spindle. The protrusions and lugs act as a ratchet mechanism; rotating the spindle in one direction and the spindle remaining in its angular position in the other direction, irrespective of whether the filter cup is manipulated or not. The assembly is complex in construction and requires a large number of structural components.

Disclosure of Invention

The object of the invention is to provide a backflush filter of the type mentioned at the outset, which is of relatively simple construction and for which a relatively large stroke is achieved with a relatively small angle of rotation.

According to the invention, this object is achieved by an assembly of the type mentioned at the outset, which is characterized in that:

(g) the filter cup is internally provided with a profile (Profile) having a profile with different heights along the axial direction; and is

(h) The filter element or the discharge end closure part rests at least partially against the contour, so that a rotation of the filter cup causes an axial movement of the filter element and of the discharge end closure part.

The filter element and the discharge end-closing member form a common axially movable, non-rotatable structural assembly. The components of the assembly, i.e. the filter element or the discharge end closure part, rest on the bottom of the filter cup or rest against the inner wall of the filter cup. In this region, the filter cup is shaped (profilert). The profile of the profile varies with the angle in height, that is to say in the axial direction. If the filter cup is now rotated, the structural assembly with the filter element and the discharge end-closing member follows the contour. The filter cup can in particular be injected from a cost-effective synthetic material. The profiled section is then particularly easily produced on the inner side.

In one embodiment of the invention, the molding is arranged at the bottom of the filter cup. The bottom has "peaks" and "valleys", for example in a recess, along a ring, by which a part of the discharge end-closing member works if the filter cup is rotated (l ä uft). However, it is also possible to shape the inner wall of the filter cup, for example, with a corrugated ring projection on which the projection at the structural assembly consisting of filter element and discharge end closure part works.

If the profile is arranged at the bottom of the filter cup, it is advantageous if the discharge end closure element has at least one projection on the side facing the bottom of the filter cup, which projection rests on an angular range (winkelbeich) of the profile. The projection can then be worked by the forming section.

In an advantageous embodiment of the invention, it is provided that the discharge end closure part has a disk-shaped central part with a circumferential seal, which is screwed into a recess in the bottom of the filter element with an upwardly projecting threaded pin and that at the underside of the central part at least two projections are provided, which are formed by elongate (langestreckten) projections extending in the radial direction. However, it is of course also possible to connect the discharge end closure element to the filter element in other ways, for example by means of clips, tabs or by molding. The number of bumps can also vary. It can therefore be sufficient to use only one projection. The extension of the cam over a limited angular range enables a sensitive scanning (abdasten) of the profile.

In a further embodiment of the invention, an elongated guide element is provided, which is molded in the middle to the underside of the discharge end closure element, extends into the discharge end and is provided with longitudinal grooves. The discharge end closure member is guided in the discharge end so as to be axially movable with the guide member. The channel effects water flow through the open discharge end.

A particularly preferred embodiment of the invention provides a spring which presses the filter element against the profile. In addition to the system pressure, the spring presses the filter element and the outlet end closure element downward, so that the projection rests fixedly on the profiled contour. Furthermore, the combination of system pressure and spring force causes the circumferential seal to press against the filter cup. This prevents leakage of the fitting in the operating position, which is described in the following paragraphs.

Two positions can be realized with the forming section: the run position (in which the lug is in the "valley" and the discharge valve is closed) and a flush down position in which the lug is on the "peak" and the discharge valve is open. However, it is also possible for the contour of the profile to have three different heights in the axial direction, which are configured such that the discharge end is closed by the discharge end closure element at a first height, a gap is formed at a second height, through which water can flow from the channel to the discharge end, and a gap is formed at a third height, which is greater than the gap at the second height, for which gap water can additionally flow from the annular space to the discharge end. In the intermediate position with the slit being relatively narrow, all the water flows through the channel. Thereby achieving a large suction effect in the back flushing direction. In the final position, water also flows from the annular space through the slits. The dirt which has settled in the annular space can then likewise be removed, although the greatest attraction is not achieved.

In a further embodiment of the invention, it is provided that the transition between the regions of different heights is flattened (abgeflacht) in one direction and has sharp edges from opposite sides. Thereby achieving only one direction of rotation. If the sharp edge of the profile strikes against the projection, the rotation is prevented as in the case of a ratchet mechanism.

In one embodiment of the invention, six channel walls are provided on the inside of the filter cup, which form three channels. The channels are each angularly offset by 120 degrees and are evenly distributed along the inner wall portion of the filter cup. The entire filter surface is cleaned with a small rotation of at least 120 degrees. To ensure that the angle of rotation is sufficient, the profile is repeated only twice along the entire angular range of 360 degrees. Upon rotation, the installer gets tactile feedback if the profile is stroked at maximum height and back into the "valley". Alternatively, four channels and three profile cycles can also be provided.

The invention can be provided in particular with a channel element which opens with an upper end into an outlet channel in the fitting housing, which is connected to the outlet, and on the lower end of which the filter element is guided axially movably and which has a projection at the upper end, which engages in a groove in the inner wall of the fitting housing. In this way, it is ensured that the filter elements do not rotate simultaneously. It goes without saying that the channel element can also be formed in one piece with the filter element.

The assembly according to the invention uses the channel wall for forming a channel in which a suction force is generated when opening the discharge end. The channel wall is part of the filter cup. By rotating the filter cup, the channel moves past the filter element with the open side located inside. In this case, the dirt particles are sucked off over the entire height in each angular range and are removed via the discharge end. The back flush is triggered and performed by rotation of the filter cup. In an operating state, water flows from the inlet into the annular space. From the annular space, the water flows through the cylindrical filter element into the central region and from there in the filtered state to the outlet.

The assembly uses a discharge end-closing member instead of a ball valve. The back flush position is achieved by opening the discharge end. The lugs and the formations act as a ratchet mechanism: the filter cup can be rotated in one direction and prevented from rotating in the other direction. Inversion is neither possible nor required. The assembly can also be rotated without excessive rotation. The rotation can be performed until the filter is sufficiently back-flushed.

The filter cup is preferably fixed to an adapter which is connected to the fitting in a rotatable manner in such a way that the adapter and the filter cup form a rotatable assembly. In particular, grooves or projections can be provided at the adapter and/or at the filter cup in order to increase the roughness.

The filter element is preferably formed by a filter element arranged coaxially in the filter cup, which has a plurality of annular ribs arranged axially one above the other and connected to one another by connecting struts. Such a filter element can be flushed down well. The filter element can be made of a durable synthetic material, as can many of the other components.

In a further embodiment of the invention, a cover ring for closing the channels is provided at the upper end, wherein the angular range of the cover ring between the channels is uncovered. Instead of a cover ring, the channel can also be closed in other ways.

In one embodiment of the invention, the fitting has a barrier for blocking the inlet. The barrier enables easy maintenance of the assembly.

The design of the invention is the subject of the dependent claims. The embodiments are further explained below with reference to the drawings.

Definition of

In the present description and in the appended claims, all concepts have the meaning familiar to the person skilled in the art, which are set forth in the specialist literature, standards, in particular DIN EN 806-1 and DIN EN 1717, and in particular dictionary-type, such as www.Wikipedia.de, www.wissen.de or www.techniklexikon.net, competitors, institutes, universities and associations, such as the registered association german gas and water industry association or the german engineer association, related web pages and publications. In particular, the concepts used do not have the reverse meaning as would occur to one skilled in the art from the above disclosure.

In addition, the following meanings for the concepts used are based here:

a barrier member: are each type of mechanism that completely or partially blocks fluid flow. Typical barriers are ball valves or valves.

Accessories: are structural components for installing in or at ductwork or other fluid-handling equipment for baffling, conditioning or influencing a material flow (stoffstrnmen). The fitting can be constructed in one piece or in multiple pieces and is mounted at a location in or at the pipe line. The accessories are for example and not decisively: coupling device, hookup accessory, main separation accessory, maintenance accessory, throttle accessory, get material position, get material accessory, evacuation accessory, insurance accessory, safety accessory and timing accessory.

And (4) outlet: is an opening in the housing on the discharge side, through which the material flow can flow out. The opening can in particular be coupled to a pipe line or another fitting or be open to the atmosphere in a vented manner.

Axial direction: is the direction of the axis of rotation of a fully or partially rotationally symmetrical structural component, such as, for example, a pipe or an elongated housing. For structural components without rotational symmetry, this is the main flow direction in the structural component section.

Opening a hole: is a connection of each type of two hollow spaces, and a blind hole.

An inlet: is an opening in the housing on the entry side into which the material flow can flow. The opening can in particular be coupled to a pipe line or another fitting or be open to the atmosphere in a vented manner.

A spring: a resilient structural member which is capable of deforming, but in particular not only a metallic coil spring.

A filter: is a mechanism by which solid material from a fluid stream is trapped.

A housing: outward restraints for materials, structural components, instruments and gauges. The housing can be designed as a single piece or as multiple pieces from a plurality of connected housing parts and made of one or more materials (materialies).

Nut: a machine element for establishing a releasable connection. The nut is a hollow body with an internal thread.

Radial: perpendicular to the axial direction.

Pipeline: a hollow body consisting of a cylindrical section. Typically as a pipeline.

Back flushing: through the flow member or filter material in the opposite direction and discharge the flushing medium outwards.

Back flushing the filter: the filter was cleaned by back flushing.

Shoulder: transition of sections of different diameter or thickness.

Taking over: a rim or transition at the opening.

A valve: structural components for blocking or regulating the flow of fluid.

Drawings

FIG. 1 is a longitudinal section through a backflush filter in an operating position along a section plane A-A;

FIG. 2 is a longitudinal section through the backflush filter from FIG. 1 along a section plane B-B which is rotated at an angle relative to the section plane A-A;

FIG. 3 is a detail from FIG. 1 with the discharge end at the end below the backflush filter in the operating position;

fig. 4 shows the backflush filter similar to fig. 2 in an intermediate position between the operating position and the backflush final position;

FIG. 5 is a detail similar to FIG. 3 in the intermediate position;

FIG. 6 shows a backflush filter similar to FIG. 2 in a backflush-final position;

FIG. 7 is a detail similar to FIG. 3 in the back flush-final position;

FIG. 8 is a perspective view from above into the lower portion of the filter cup from the backflush filter of FIG. 1 taken along section line D-D in FIG. 9;

FIG. 9 shows a cut line D-D of the view in FIG. 8;

figure 10 shows a portion of the contour extension of the bottom of the filter cup in the peripheral direction;

FIG. 11 shows a section line C-C of FIG. 12;

FIG. 12 is a horizontal section through the backflush filter from FIG. 1 taken along section line C-C in FIG. 11;

FIG. 13 is a perspective view, partially in section, of a filter element from the back flush filter of FIG. 1;

FIG. 14 shows a detail from FIG. 13;

FIG. 15 is a perspective view of a tubular middle section having nubs for the back flush filter from FIG. 1;

FIG. 16 is a longitudinal section through the middle section from FIG. 15;

FIG. 17 is a perspective view, partially in section, of a filter element from the back flush filter of FIG. 1;

FIG. 18 is a longitudinal section through the filter element from FIG. 17 along section line A-A;

FIG. 19 is a perspective view of a discharge end-closure member for the backflush filter from FIG. 1;

FIG. 20 is a side view of the discharge end-closure member from FIG. 19;

FIG. 21 is an exploded view of the back flush filter from FIG. 1;

FIG. 22 is a cut-away perspective view of the filter from FIG. 1 without the filter bowl; and

fig. 23 is a cut-away perspective view of the bottom of a filter cup with an associated discharge end for the filter from fig. 1.

Detailed Description

Fig. 1 shows a filter fitting for drinking water, generally designated 10. The fitting 10 has a fitting housing 12 with an inlet 14 and with an outlet 16 arranged coaxially with the inlet. The fitting housing 12 can be fitted into a pipe line (not shown). For blocking the inlet 14, a conventional ball valve can be provided. The inlet 14 connects the fitting 10 to a drinking water supply, not shown. The water flowing out of the outlet 16 is directed further to a tap in the building.

The filter assembly 10 has a filter cup 18 made of a synthetic material. The fitting housing 12 has a coupling socket 22. The filter cup 18 is provided with an external thread 20. The filter cup 18 is screwed into an adapter 21 made of synthetic material by means of the external thread 20. On the outside of the adapter 21, a rib 19 is molded, which can be seen well in fig. 9, 11 and 21. The ribs 19 allow the user to easily perform the rotation described below.

A sealing ring 23 is arranged in an annular groove at the upper end of the filter cup and seals against the adapter 21. The upper end 27 of the adapter 21 is inserted into the connecting stub 22, which has two annular grooves in this region, each with a sealing ring 25. The two sealing rings 25 seal against the upper end 27 of the adapter 21. The coupling nipple 22 has a groove at the lower end. In the axial direction, the adapter 21 is held by a clip 29. The clip is shown in figure 21. The clip 29 is clipped into a slot in the area below the adapter, as this is shown in fig. 21. The clip engages in the groove at the lower end of the coupling stub 22. The adapter 21 is seated on the coupling socket 22, i.e. in an axially immovable and sealed manner, but together with the filter cup 18 can rotate freely relative to the fitting housing 12.

A discharge end 26 is provided in the bottom region of the filter cup 18. In the operating position, the outlet end 26 is closed by an outlet end closure element 28 and a surrounding valve seal 32. The operating position is shown in fig. 1 to 3. A guide element 30 arranged at the discharge end closure element 28 is guided in the discharge end 26 so as to be axially movable.

A filter element 48, which is shown separately in fig. 17 and 18 again, is arranged coaxially in the filter cup 18. The filter element 48 is a composite material part. The filter element 48 has a plurality of annular ribs 52, which are arranged axially one above the other. The ribs 52 form a columnar shape. The ribs 52 are connected to each other by vertical connecting struts 60. The connecting struts 60 form a support body and can be seen well in fig. 18.

The upper part 24 of the filter element is designed to be continuous. No water can flow through the section in the radial direction. At the lower end, the filter element 48 forms a closed bottom 42. An internal thread 43 is provided in the upwardly projecting recess of the base 42. The discharge end closure member 28, which is explained further below, is screwed into this internal thread 43 with a threaded pin 45 projecting upwards. The discharge end closure member 28 is shown in isolation in fig. 19 and 20. In this way, the filter element 48 is fixedly connected to the discharge end closure element 28.

The discharge end-closing member has a disc-shaped intermediate portion 47. The threaded pin 45 extends upwardly from the intermediate portion 47. A further pin 49 is placed on the threaded pin 45. In the assembled state, the pin 49 projects into an associated recess in the base 42 of the filter element 48. An elongated guide member 30 is molded in the middle at the lower side of said middle portion 47. The guide member 30 has a cross-shaped cross-section in the horizontal direction. This can be seen well in fig. 19. The longitudinal grooves formed by the cross shape allow a flow of water along the guide member if water flows by the intermediate portion 47. Below the intermediate portion 47, two opposing projections 51 are molded onto the guide element 30, the projections 51 extending in the radial direction almost as far as the rim of the intermediate portion 47.

Between the inner wall of the filter cup 18 and the filter element 48, an annular space 38 is formed, which is formed by three ring-mounted segments, which are separated from the channel 82 as described below. The annular space 38 opens into the inlet 14 at the upper end. The lower end of the annular space 38 opens into the region 36 above the ring shoulder 39 formed above the bottom 34 of the filter cup 18. The bottom 34 is provided with a discharge opening which opens into the discharge end 26. The guide element 30 of the discharge end closure element 28 extends into a discharge opening in the bottom 34 of the filter cup 18.

The rim of the intermediate portion 47 is provided with a surrounding valve seal 32. The valve seal 32 can be seen well in fig. 3 and 5. The valve seal 32 has a cross section of a flat L and has a lip 53 in the region of the base 34. The lip 53 extends obliquely outward and downward as far as the bottom 34. An improved sealing action is thereby achieved.

The bottom 34 of the filter cup 18 is shaped in a deepened axial region (Achsbereich) 63. This can be seen well in fig. 8. A rim 65 is formed around the recess 63. The profile 55 of the profile and the rim 65 are shown in fig. 10 and 23. The profile 55 has two opposite raised areas 57. Two deepened regions 61 are located next to the raised regions 57 in the clockwise direction. Between the deepened region and the raised region, two opposite intermediate regions 59 are respectively present, which intermediate regions 59 are only slightly raised. In the assembled state, the projection 51 rests on the contour 55. If the projection 51 is placed in the deepened region 61, the valve seal 32 is placed on the rim 65. The discharge end 26 is then closed. No water can flow down. This is the operating position shown in fig. 1 to 3.

The discharge end closure element 28 is moved in the axial direction by rotation of the adapter 21 or of the filter cup 18 connected to the adapter 21. Where the contour 55 moves along the cam 51. The axial movement of the discharge end closure part 28 can be achieved by means of an anti-rotation bearing of an internal component at the fitting housing 12, which is described below. The discharge end 26 is opened if the discharge end closure element 28 is moved upward out of the discharge end 26. If the central region 59 is located below the cam 51, the discharge end closure element 28 is first moved from the operating position in the deepened region 61 into a central position corresponding to the contour 55 shown in fig. 10. The intermediate position is shown in fig. 4 and 5. As the filter cup 18 continues to rotate, the raised area 57 is below the tab 51. The discharge end 26 is then fully open. This is the final position of the back flush, which is explained further below with reference to fig. 6 and 7.

In the fitting housing 12, a wall 46 is molded between the inlet 14 and the outlet 16. An upwardly tapering channel element 50 is provided opposite the outlet side of the wall portion 46. The channel element 50 extends coaxially with the filter element 48, with the filter cup 18 and with the coupling socket 22 over the length of the coupling socket 22 into the filter cup 18. The channel elements are again shown separately in fig. 15 and 16. The channel element 50 has a substantially cylindrical through-opening in the longitudinal direction, which opens at the upper end into an outlet channel 54 in the fitting housing 12, which is connected to the outlet 16.

Two projections at the ends above the channel element 50 on the outside engage in suitable grooves 41 in the inner wall of the fitting housing 12. The protrusion can be seen well in fig. 11. The groove can be seen in fig. 22. The channel element 50 is held in position in the channel element 50 by the projection in a rotationally fixed manner and fixed to the housing. Two

ring projections

79 and 81 are provided in the lower region of the channel element 50. A seal 56 is arranged between the

ring projections

79 and 81. The channel element 50 is inserted with the seal 56 into the filter element 48. This can be seen well in fig. 14.

The channel element 50 is fixedly connected to the fitting part 12. The filter element 48 is inserted in a rotationally fixed but axially movable manner onto the channel element 50. A stop 85 at the filter element 48 limits movement of the filter element 48 relative to the channel element 50. Above the seal 56, four projections 55 are molded to the channel element 50, the four projections 55 extending externally along the periphery (Mantels) in the axial direction. The projection 55 can be seen well in fig. 15 and 16. The channel element 50 is centered in the upper socket 67 of the adapter 21 by means of the projection 55.

In the region of the lower rim of the channel element 50, the channel element has four notches 87. The notch 87 can be seen well in fig. 15 and 16. The notch 87 is open downward and extends up to just below the ring projection 81 and the seal 56. Between the indentations, a buttress-like corner section 69 with a slightly smaller wall thickness is placed. On the corner section 69, the filter element 48 is guided in an axially movable manner in the region between the struts 60.

The filter element 48 defines a central passage 64. The connecting strut 60 has a plurality of regions of different thicknesses in the radial direction. This can be seen well in fig. 17 and 18. In the upper part 24, the connecting strut 60 has a large size. The intermediate region 31 has a slightly smaller dimension in the radial direction. The shoulder thus formed forms the stop 85. At the lower end 35, the connecting struts 60 have a smallest dimension in the radial direction. Thereby forming an additional lower shoulder 37. The region 35 terminates downwardly with the bottom 42 of the filter element 48.

A spring 89 is supported on the shoulder 37 formed at the connecting strut 60. The spring seat 91 of the spring 89 is formed above the castellated projection by the underside of the channel element 50 and of the ring projection 81. The spring 89 presses the filter element 48 and the discharge end closure part 28, which is fixedly connected to the filter element 48, downward. The projection 51 is in permanent contact with the contoured bottom 63 of the filter cup 18 due to the spring force of the spring 89.

On the inside of the filter cup 18, 6

channel wall sections

78, 80 are molded in pairs. The channel walls can be seen well in fig. 12. Respective pairs of channel walls, such as

channel walls

78 and 80 in fig. 12, form channels 82. The channels 82 formed by the channel walls 78 and 80 (in the present embodiment, these are three channels 82) extend towards the bottom over the entire height of the filter cup 18. The lower end of the channel 82 opens into the region 40 above the bottom 34 of the filter cup 18. The area below the channel 82 can be seen in fig. 8. Where the filter element 48 is supported. At the upper end of the channel 82, a cover ring 83 is provided, with which the channel 82 is closed off upwards. The covering ring 83 can be seen well in fig. 21. The angular extent of the covering ring 83 between the channels 82 is uncovered. Accordingly, water can pass through the angular extent of the annular space between the channels 82. The arrows 92 on the fitting housing 12 on the outside show the flow direction of the water fitted to the fitting, as can be seen in fig. 10.

In the operating position shown in fig. 1 to 3, water flows through the inlet 14 into the fitting housing 12 in the direction of the arrow 44. Where the water flows outwardly past the channel element 50 in the direction of the arrow 58 and down into the annular space 38. Water flows inwardly from the annular space 38 through the filter element 48 in the direction of arrow 62. The filter element 48 is hollow on the inside in the present exemplary embodiment and forms a central channel 64 for the filtered water. From the central passage 64, the water flows internally through the passage element 50 to the outlet passage 54. This is represented by arrow 66. The water is then available for further use at the outlet 16.

The filter formed by the filter element 48 becomes clogged over time. The dirty particles are here on the outside of the filter. For cleaning, the filter is back-flushed, i.e. water flows in the opposite direction through the filter and the dirt particles are detached there.

For current filters, two backwash positions can be achieved: intermediate positions and final positions. The intermediate position is shown in fig. 4 and 5 and the final position is shown in fig. 6 and 7.

For the back flushing, the rotationally movable assembly of adapter 21 and filter cup 18 is rotated in the clockwise direction. For better handling, the adapter 21 has a rib 19 for this purpose, which rib 19 can be seen in fig. 9. As the rotationally movable assembly rotates, a contoured axial region 63 of the bottom 34 of the filter cup rides over the nub 51.

The contour 55 is flattened on the left-hand side of the raised area 57 in fig. 10 and has a sharp edge 90 on the other side of the raised area 57. If the filter cup 18 is moved in a clockwise direction in fig. 8, this movement is prevented at the edge 90 by the projection 51. Movement in the opposite direction, i.e. counter to the clockwise direction, is maintained possible by the flattened side 88. That is to say that the profile 55 acts like a ratchet for the projection 51. Movement in one direction is allowed wherein the characteristic ratcheting sound is audible and perceptible. The discharge end closure element 28 is then moved in the axial direction at the projection 51. The movement is prevented in the opposite direction.

Since the filter element 48 is fixedly connected to the discharge end closure part 28, the combination of filter element 48 and discharge end closure part 28 moves upward in the axial direction during the rotational movement of the filter cup 18. The position shown in fig. 4 and 5 in the intermediate position is reached first. In this case, the projection 51 rests on a region 59 of the contour 55. In the intermediate position, the contour 55 and the cam 51 have an angular position in which the region 40 of the channel 82 is just open, but the annular space 38 is not open. The valve seal 32 is moved slightly upwards in the intermediate position and the discharge end 26 is already slightly open. An elongated slit is formed below the region 40 in the channel 82, so that water can flow past the seal 32 through the discharge end. Water is directed from the inlet 14 into the annulus 38. Water flows from the annulus 38 through the filter in the direction of arrow 96 in fig. 12. The annular space 38 ends downwards by an annular shoulder 39 of the filter cup 18. Water flows from the interior space through the filter in the opposite direction into the channel 82. This is illustrated by arrow 96 in fig. 12. The channel 82 is connected to the region 40 at the bottom of the filter cup. Through the open discharge end 26, the water is caused to flow downwardly from the region 40 and to create a suction effect in the channel 82. The suction causes water to flow from the interior region of the filter in the opposite direction through the filter into the channel 82 and from there to the discharge end 26. Dirt particles are carried away from the outside of the filter and are removed together with the backflushing water via the discharge end 26. The passage 82 successively runs through a large angular range of the filter when the assembly of adapter 21 and filter cup 18 is rotated. In this way, the filter is cleaned well.

In the region 36 above the ring shoulder 39 at the lower end of the ring space 38, coarse dirt, such as small stones, can accumulate. These small stones may not be flushed down into the discharge end 26 in the intermediate position. As can be seen well in fig. 10, the contour 55 is therefore provided with a further raised region 57, which region 57 lifts the seal 32 into the final position of the back flush. The final position is shown in fig. 6 and 7. In this position, the filter element 48 is moved in the axial direction to such an extent that a connection is established between the region 36 and the discharge end 26. Coarse dirt is also flushed out of the annular space 38 through the connecting channel 98. The connecting channel 98 laterally to the

channel walls

78 and 80 can be seen in fig. 7, 8 and 12.

In the intermediate position, the entire water flow is guided through the channel 82. Thereby achieving a high pumping action. The particles adhering to the filter element on the outside fall off well. The end position is reached if each channel 82 runs through the angular range to which it belongs, i.e. approximately one third of the circumference of the filter element in the present exemplary embodiment. In the final position, a portion of the water flows through the annular space 38 to the discharge end 26. Accordingly, the suction effect becomes smaller, but coarse particles at the lower end of the annular space 38 are removed.

The assembly has the advantage that the installer is able to apply no excessive force. Excessive rotation of the assembly and the resulting damage is not possible. If necessary, a further rotation (umdrehunen) can be carried out for the filter cleaning. With the assembly the back flush is already achieved with a small rotation. The assembly requires only few structural components. The contour 55 can be easily molded at the bottom of the filter cup 18.

The present embodiment uses two projections together with two opposing raised areas 57 and the associated profile, and three channels 82. It goes without saying that three or more projections and four or more channels can also be used. It is only important that the cam 51 moves the filter at least through an angular range on its way through the contour section, so that the filter is completely cleaned.

In the present exemplary embodiment, the axial movement of the filter element 48 is caused by a contour 55, the contour 55 being provided in three states. However, it is also possible to use other contours which achieve two or more than three states.

The embodiments explained above are intended to explain the invention as claimed in the claims. Features disclosed in connection with other features can also be used in general, either individually or in combination with other features disclosed in the text or in the drawings, explicitly or implicitly in the embodiments. The dimensions (Ma β e) and size are merely exemplary. Suitable areas of knowledge will be available to the person skilled in the art from his expert knowledge and therefore need no further explanation here. The disclosure of a particular design of a feature does not imply that the invention should be limited to this particular design. Rather, such a feature can be realized by numerous other designs familiar to those skilled in the art. The invention can therefore be realized not only in the form of the illustrated design, but also by all designs covered by the scope of protection of the appended claims.

The concepts "up", "down", "right" and "left" are based solely on the drawings. It goes without saying that the claimed device can also adopt other orientations. The concept of "comprising" and "comprises" means that further, unrecited components can be provided. All features which have a property or a content (Gehalt) in the majority, i.e. more than all other mentioned components or properties which have the stated characteristic, i.e. components or properties which have more than 50% of the characteristic for two components, for example, belong to the concepts "substantially", "essentially" and "mostly".

Claims

1. A back flush filter assembly (10) comprising:

(a) a fitting housing (12) having an inlet (14) and an outlet (16);

(b) a filter cup (18) connected to the fitting housing (12) and having a discharge end (26);

(c) a substantially cylindrical filter element (48) arranged in flow relation between the inlet (14) and the outlet (16), which filter element is arranged in the filter cup (18) such that an annular space (38) is formed between the filter element (48) and the filter cup (18);

(d) a discharge end-closing member (28) fixedly connected to the filter element; and

(e) channel walls (78, 80) extending in the axial direction, which are molded in pairs to the inner wall section of the filter cup (18) and extend over the entire height of the filter element (48) and form one or more channels (82) which are closed upwards and in the peripheral direction, open downwards towards the discharge end (26) and inwards in the radial direction;

wherein the content of the first and second substances,

(f) said filter assembly being switchable from a first state, in which water flows from the inlet (14) through the filter element (48) to the outlet (16), into at least one second state, in which the water flows from the inlet (14) through the filter element (48) in the opposite direction to the discharge end (26) with the discharge end-closing member (28) open;

it is characterized in that the preparation method is characterized in that,

(g) the filter cup (18) is internally provided with a profile (55) having different heights in the axial direction; and is

(h) The filter element (48) or the discharge end closure part (28) rests at least partially against the contour, so that a rotation of the filter cup (18) causes an axial movement of the filter element (48) and of the discharge end closure part (28).

2. A backflush filter assembly (10) according to claim 1, wherein the forming section is disposed at the bottom of the filter cup (18).

3. A backflush filter assembly (10) according to claim 2, wherein the discharge end closure element (28) has at least one projection (51) on the side facing the bottom of the filter cup, which projection rests on an angular extent of the profile.

4. A backflush filter assembly (10) according to claim 3, wherein the discharge end closure part (28) has a disk-shaped central part (47) with a circumferential seal, which is screwed with an upwardly projecting threaded pin (45) into a recess in the bottom (42) of the filter element (48), and at the underside of which at least two projections (51) are provided, which are formed by elongate projections extending in the radial direction.

5. A backflush filter assembly (10) according to any one of claims 1 to 4, wherein an elongate guide member (30) is molded centrally to the underside of the discharge end closure member (28), said guide member extending into the discharge end (26) and being provided with longitudinal grooves.

6. Back-flush filter assembly (10) according to any of claims 1 to 4, characterized by a spring pressing said filter element (48) against said formation.

7. Back-flush filter assembly (10) according to one of claims 1 to 4, characterized in that the contour (55) of the profile has three different heights in the axial direction, which heights are configured in such a way that the discharge end (26) is closed by the discharge end closure element (28) at a first height; forming a gap at a second height through which water can flow from the channel (82) to the discharge end (26); and in the case of a third level a gap is formed which is larger than in the case of the second level, in which gap water can additionally flow from the annular space (38) to the discharge end (26).

8. A back flush filter assembly (10) as claimed in claim 7, wherein the transition (88) between the regions (57, 59, 61) of different heights is flattened in one direction and has sharp edges from opposite sides (90).

9. A backflush filter assembly (10) according to claim 1, wherein six channel walls (78, 80) are provided on the inside of the filter cup (18), the six channel walls forming three channels (82).

10. Back-flush filter assembly (10) according to claim 1, characterized by a channel element (50) which opens with an upper end into an outlet channel (54) in the fitting housing (12) which is connected to the outlet (16) and on the lower end of which the filter element (48) is guided axially movably and which has a projection at the upper end which engages in a groove in the inner wall of the fitting housing (12).