EP1720666A1

EP1720666A1 - Surface cleaning head

Info

Publication number: EP1720666A1
Application number: EP05707682A
Authority: EP
Inventors: Felix Treitz
Original assignee: Alfred Kaercher SE and Co KG
Current assignee: Alfred Kaercher SE and Co KG
Priority date: 2004-03-05
Filing date: 2005-03-02
Publication date: 2006-11-15
Anticipated expiration: 2025-03-02
Also published as: DE102004013057B3; ATE486671T1; DK1720666T3; WO2005084828A1; EP1720666B1

Abstract

The invention relates to a surface cleaning head (10) comprising a hood-shaped housing (12) which is provided with a fluid outlet (19) and wherein at least one spray arm (40,41, 42) is mounted such that it is freely rotatable about an axis of rotation (35), wherein said arm bears a nozzle (47,48,49) which rotates around the axis of rotation, together with the spray arm (40,41, 42) when impinged upon with pressurized cleaning fluid. The aim of the invention is to further develop the surface cleaning head (10) such that a surface (22) can be cleaned with an even cleaning effect even in corner and edge areas. According to the invention, the fluid outlet (19) is arranged in a region of the housing (12) which is oriented in a slanted or perpendicular manner in relation to the axis of rotation (35), wherein the jet of cleaning liquid can be discharged from the nozzle (47,48,49) through the liquid outlet (19), covering the surface that is to be cleaned (22) in a strip-like manner.

Description

Surface cleaning head

The invention relates to a surface cleaning head with a hood-shaped housing which has a liquid discharge opening and in which at least one spray arm is freely rotatable about an axis of rotation and carries a nozzle which rotates around the axis of rotation together with the spray arm when subjected to pressurized cleaning liquid.

Surface cleaning heads of this type can be connected to a source of cleaning fluid under pressure, for example to a high-pressure cleaning device. A surface cleaning head is known from DE 102 06 013 C1, in which the axis of rotation of the spray arm is oriented perpendicular to the surface to be cleaned, which is acted upon by all nozzles simultaneously with liquid jets circulating on a circular path. A good cleaning effect can thus be achieved, but it has been shown that in particular corner and edge regions of a surface to be cleaned cannot be completely covered by the cleaning liquid jets in all cases. In addition, the circular action on the surface to be cleaned leads to surface overlaps of the liquid jets when the surface cleaning head is moved along a working direction. This in turn results in a non-uniform cleaning effect.

The object of the present invention is to develop a surface cleaning head of the type mentioned at the outset in such a way that a surface with a uniform cleaning action can also be cleaned in corner and edge regions.

- 2nd

This object is achieved according to the invention in a surface cleaning head of the generic type in that the liquid discharge opening is arranged in a region of the housing which is oriented obliquely or perpendicular to the axis of rotation, a cleaning liquid jet covering the surface to be cleaned being able to be stripped through the liquid discharge opening through the rotating nozzle.

According to the invention, the axis of rotation of the spray arm and the nozzle is oriented obliquely or perpendicularly to the liquid discharge opening of the housing, so that the nozzle rotating around the axis of rotation only faces the liquid discharge opening along part of its orbital movement, while in the remaining region of its circulating movement it faces away from the liquid discharge opening. During its orbital movement, it therefore sweeps over the liquid discharge opening and through it can act on the surface to be cleaned in a strip shape with a cleaning liquid jet. This has the advantage that the surface is cleaned in a strip shape when the surface cleaning head is moved along a working direction. The distance between the nozzle and the surface to be cleaned can be kept very small, so that an intensive jet of cleaning liquid can be directed onto the surface.

The configuration according to the invention also has the advantage that a large working width can be achieved by means of the surface cleaning head with a small distance between the nozzle and the surface to be cleaned. Surface overlaps of the cleaning liquid jet, as cannot be avoided in the construction known from DE 102 06 013 Cl, can be contemporary design can be avoided. The surface to be cleaned can be cleaned uniformly, the strongest cleaning effect being obtained in a central region of the surface cleaning head, while in the construction known from DE 102 06 013 Cl the strongest cleaning effect occurs in an edge region of the surface cleaning head.

Another advantage of the surface cleaning head according to the invention is that it can be made very flat. This is of great advantage in particular for cleaning edge and corner areas of a surface, for example for cleaning stairs.

It is expedient if the nozzle held on the spray arm is designed as a point jet nozzle, because this allows an intensive jet of cleaning liquid to be generated which covers the surface to be cleaned in a strip shape.

In a preferred embodiment of the surface cleaning head according to the invention, cleaning liquid can be applied to the nozzle non-uniformly during its orbital movement about the axis of rotation, the greatest amount of cleaning liquid being applied when the nozzle is oriented in the direction of the liquid discharge opening. As already explained, the nozzle is aligned along a partial region of its orbital movement in the direction of the liquid discharge opening, while in the remaining region of the circulatory movement it faces away from the liquid discharge opening. It is expedient for the nozzle to be acted upon with cleaning liquid practically only during its partial region of the circulating movement which faces the liquid discharge opening

4 -

is, while it experiences practically no exposure to cleaning liquid during its remaining orbital movement.

Thus, it can be provided, for example, that the nozzle can be acted upon with a maximum amount of cleaning liquid over a first portion of the circulation movement facing the liquid discharge opening, while it can be acted upon with a minimal amount of cleaning liquid over a second portion of its circulation movement facing away from the liquid discharge opening. In particular, it can be provided that cleaning liquid cannot be applied to it at all during its second partial area, that is to say a cleaning liquid supply to the nozzle is interrupted during the second partial area of the circulating movement.

It is particularly advantageous if the surface cleaning head has a plurality of spray arms arranged distributed in the circumferential direction, on each of which a nozzle is held, the nozzles being able to be acted upon by more cleaning liquid during their circulating movement if they face the liquid discharge opening than if they face away from the liquid discharge opening are. The nozzles rotating around the axis of rotation are always supplied with a larger amount of cleaning liquid when they face the liquid discharge opening. Thus, the cleaning liquid is supplied to the nozzles sequentially, in each case the nozzle is supplied with a larger amount of cleaning liquid which is currently facing the liquid discharge opening, while the nozzles facing away from the liquid discharge opening at this moment are supplied with a smaller amount of cleaning liquid, in particular for the last mentioned nozzles the cleaning liquid supply must be completely interrupted.

It has proven to be advantageous if the surface cleaning head has three spray arms arranged uniformly distributed in the circumferential direction with one nozzle, the nozzles being able to be acted upon with more cleaning fluid over a partial region of approximately at least 120 ° of their circulating movement than over the remaining region of their circulating movement.

It is particularly advantageous here if more of the cleaning fluid can be applied to the nozzles over a partial region of their orbital movement from approximately 130 ° to approximately 150 °, in particular approximately 140 °, than over the remaining region of their orbital movement. Such an embodiment has the result that the cleaning liquid is supplied to the rotating nozzles in an overlap area of approximately 10 ° to approximately 30 °, in particular approximately 20 °, simultaneously to two nozzles. This is the case when a first nozzle just leaves its part of the circulating movement facing the liquid discharge opening, while a second nozzle following in the circulating direction enters this part.

In a preferred embodiment, the at least one spray arm is rotatably held on a hollow shaft, the hollow shaft having an axial bore which can be brought into flow connection with a through bore of the spray arm via a connecting groove running only over a partial area in the circumferential direction of the hollow shaft. If the spray arm is arranged in the area of the connecting groove of the hollow shaft, there is a flow - 6th

Connection between the axial bore of the hollow shaft and the through bore of the spray arm. However, the connecting groove extends in the circumferential direction only over a portion of the hollow shaft, so that the flow connection between the axial bore and the through bore is interrupted when the spray arm assumes a position outside the connecting groove. The spray arm rotating around the hollow shaft is thus supplied with cleaning liquid unevenly during a rotating movement, namely whenever there is a flow connection between the axial bore and the through bore via the connecting groove. The nozzle arranged on the spray arm is consequently supplied with cleaning liquid unevenly during its orbital movement.

It is expedient if the spray arm is attached to a bearing element surrounding the hollow shaft. The bearing element can form a sliding bearing that bears against the hollow shaft, at least the sliding surface of which can be made, for example, of plastic, in particular based on a PEEK (polyether ether ketone) material. Alternatively, it can be provided that the bearing element is held on the hollow shaft by means of ball or roller bearings.

The hollow shaft is preferably made of brass, bronze or stainless steel.

To operate the surface cleaning head, it is connected to a source of pressurized cleaning liquid, for example to a supply line of a pressurized water supply system or to a pump, in particular a high-pressure pump, and with

- 7th

The pressurized cleaning liquid is supplied. The latter is led to the nozzle via the spray arm. A pressure field builds up on one side, namely in the circumferential area of the connecting groove, which pushes the bearing element away from the hollow shaft in this area, the bearing element being pressed against the hollow shaft on the diametrically opposite side at the same time. This can affect the uniformity of the rotational movement of the bearing element. In a preferred embodiment, the hollow shaft is therefore axially offset from the connecting groove by at least one annular groove. The annular groove enables pressure compensation in the circumferential direction of the hollow shaft and at the same time serves to axially limit the unilaterally acting pressure field. The annular groove can be arranged at a short distance from the connecting groove, preferably at a distance of less than approximately 3 mm, in particular at a distance of approximately 0.5 mm to approximately 3 mm.

An annular groove is preferably arranged in the axial direction on both sides of the connecting groove. It has been shown that a particularly stable orbital movement of the spray arm can be achieved by such a configuration.

In order to ensure a flow-tight connection between the hollow shaft and the surrounding bearing element, it is advantageous if the hollow shaft is surrounded axially offset from the connecting groove in the circumferential direction by a sealing element, preferably a piston ring.

It is advantageous here if the hollow shaft is surrounded on both sides of the connecting groove by a piston ring.

8th -

In a preferred embodiment, the at least one piston ring is made of a plastic on the basis of a PEEK material, because this enables the bearing element to rotate particularly smoothly.

To achieve a circular movement, the nozzle of the surface cleaning head according to the invention is oriented obliquely to the spray arm, so that a recoil impulse is exerted on the nozzle and the spray arm by the dispensed cleaning liquid, due to which the spray arm is rotated together with the nozzle. Depending on the pressure of the cleaning liquid, speeds of approximately 500 revolutions per minute to approximately 6,000 revolutions per minute can be achieved, preferably the speeds lie in a range from approximately 1,500 revolutions per minute to approximately 3,000 revolutions per minute.

In order to limit the speeds of the at least one spray arm, it is provided in an advantageous embodiment that a brake wing is arranged on at least one spray arm, which increases the air friction of the spray arm and thereby brakes the rotating movement of the spray arm.

It is advantageous here if at least one air supply opening is arranged on the housing adjacent to the brake wing. This allows an "air cushion effect" to be achieved, which facilitates guiding the surface cleaning head along the surface to be cleaned, in that air flows into the housing via the air supply opening and in the direction of the liquid discharge opening surface to be cleaned emerges from the housing. In addition, the braking effect of the brake blades can be increased.

In an advantageous embodiment it is provided that the at least one air supply opening can be optionally opened and closed. In particular, it can be provided that the air supply opening can be released continuously, so that the speed of the spray arm and the buoyancy of the surface cleaning head achieved by the "air cushion effect" can be changed continuously by the user.

In order to increase the cleaning effect, in a particularly preferred embodiment the surface cleaning head comprises a mechanical cleaning element which runs around the at least one spray arm and passes through the liquid discharge opening. The surface to be cleaned can be mechanically cleaned by means of the mechanical cleaning element. For example, cleaning bristles that penetrate the liquid discharge opening can be used. It has been shown that the combined use of a cleaning liquid jet and a mechanical cleaning element enables particularly good cleaning of a surface, in particular a hard surface.

The mechanical cleaning element is preferably held on at least one spray arm. Alternatively or additionally, it can be provided that a mechanical cleaning element is rotatably mounted on the hollow shaft so as to be axially offset from the spray arm. The mechanical cleaning element can be rotated together with the spray arm.

- 10th

It is advantageous if the liquid discharge opening is at least partially surrounded by a flexible splash protection element in the circumferential direction. In this way it can be ensured in a structurally simple manner that only the area of a surface covered by the liquid discharge opening is acted upon by cleaning liquid.

A bristle strip surrounding the liquid discharge opening or a rubber lip is preferably used as the splash protection element. The use of a flexible splash guard also has the advantage that it can be used to mechanically clean the surface.

The above-described hollow shaft can be mounted in such a way that it is held on a housing wall, preferably the rear wall of the housing, which can be oriented obliquely or perpendicularly to the surface to be cleaned in the position of use of the surface cleaning head. The hollow shaft can preferably be aligned parallel or at an angle of at most approximately 45 ° to the surface to be cleaned. In a particularly preferred embodiment, the hollow shaft is aligned perpendicular to the housing wall. It can be provided that the hollow shaft extends through the housing and is held both on a rear wall and on a front wall of the housing aligned parallel to this. Preferably, the housing comprises an arcuate ceiling wall, via which the front wall is connected to the rear wall. 11

In order to be able to absorb the cleaning liquid applied by the at least one nozzle onto the surface to be cleaned, it is provided in an advantageous embodiment that the surface cleaning head has a wiping lip that can be applied to the surface to be cleaned. The cleaning liquid can be moved along the surface by means of the wiper lip. It is advantageous if the wiper lip can be placed on the surface by tilting the housing about a tilt axis that can be aligned parallel to the surface to be cleaned. In a first tilt position, this makes it possible to keep the wiper lip at a distance from the surface in order to first move the surface cleaning head back and forth along the surface, and then the housing with the wiper lip can be moved into the second tilt position to apply the cleaning liquid applied to move along the surface.

In order to simplify the handling of the surface cleaning head, it is advantageous if the surface cleaning head has at least one rolling element, for example two running wheels, for supporting the surface cleaning head on the surface to be cleaned. It is advantageous if the at least one rolling element is arranged behind or laterally next to the housing of the surface cleaning head in the working direction, because cleaning of corner areas of a surface is hardly hindered by the rolling element.

In order to simplify the absorption of cleaning liquid applied to the surface, it is advantageous if the surface cleaning head has a suction channel that can be connected to a vacuum source. This enables the surface cleaning head to be designed as a spray extraction device with - 12 -

whose help a surface to be cleaned can be acted upon with cleaning liquid and this can then be suctioned off again.

The following description of preferred embodiments of the invention serves in conjunction with the drawing for a more detailed explanation. Show it:

Figure 1 is a sectional view taken along line 1-1 in Figure 2 of a first embodiment of a surface cleaning head;

Figure 2 is a sectional view of the first embodiment taken along line 2-2 in Figure 1;

Figure 3 is a sectional view corresponding to Figure 2 of a second embodiment of a surface cleaning head;

Figure 4 is an enlarged view of a hollow shaft of the surface cleaning head according to Figure 3;

Figure 5 is a sectional view taken along line 5-5 in Figure 4;

Figure 6 is a schematic representation of a third embodiment of a surface cleaning head in a first tilt position and

Figure 7 is a schematic representation of the third embodiment of the surface cleaning head in a second tilt position. 13

1 and 2 schematically show a first embodiment of a surface cleaning head according to the invention, generally designated by reference number 10. This comprises a plastic-made, hood-like housing 12 with a flat rear wall 13, a flat front wall 14 arranged at a distance from this and an arcuate ceiling wall 15 connecting the rear wall 13 to the front wall 14. The ceiling wall 15 forms a closed, semi-cylindrical upper side of the housing 12, and to the ceiling wall 15 there are flat side walls 16, 17, which also form a connection between the rear wall 13 and the front wall 14. Facing away from the top wall 15, the side walls 16 and 17, together with the front wall 14 and rear wall 13, delimit a liquid discharge opening 19 of the housing 12, which is surrounded by a bristle ring 20 in the circumferential direction. The bristle ring 20 can be placed against a surface 22 to be cleaned, enables this surface to be mechanically cleaned and at the same time serves as a splash guard.

The front wall 14 is covered by an end wall 24 which is arranged at a distance from the front wall 14 and carries a rubber wiping lip 25 at its end facing the surface 22 to be cleaned. The end wall 24 and the front wall 14 delimit a suction channel 27, at the end of which is facing away from the surface 22 to be cleaned is connected a suction nozzle 28 which can be connected to a suction line which is known per se and is therefore not shown in the drawing.

14

The housing 12 surrounds a hollow shaft 30 which is held on the rear wall 13 and has an axial bore 31. The hollow shaft 30 carries outside the housing 12 a connecting piece 33 for connection to a known and therefore not shown in the drawing supply line of a supply system for pressurized cleaning fluid, for example to the drinking water supply network or to the pressure line of a pump, in particular to the high pressure line of a high-pressure cleaner. The hollow shaft 30 is held in a rotationally fixed manner on the rear wall 13, and a rotor 36 is mounted on the hollow shaft 30 within the housing 12 so as to be freely rotatable about the axis of rotation 35 defined by the longitudinal axis of the hollow shaft 30, with a bearing bush 38 abutting the hollow shaft 30 and by this radially protruding spray arms 40, 41 and 42 arranged at a uniform distance from one another in the circumferential direction. The bearing bush 38 forms a slide bearing for the rotor 36 and is made of plastic on the basis of a PEEK material. Alternatively, a carbon material can be used to manufacture the bearing bush 38.

The spray arms 40, 41 and 42 each have a through hole 43, 44 and 45 and carry at their free end a nozzle 47, 48 and 49, which is preferably detachably connected to the respective spray arm 40, 41 and 42 and can be configured, for example, as a point jet nozzle. The nozzles 47, 48, 49 are oriented obliquely to the longitudinal axis of the respective spray arm 40, 41 and 42, preferably at an angle of approximately 5 ° to approximately 80 °. The angular arrangement of the nozzles has the result that the rotor 36 is set in rotation as soon as cleaning nozzles 47, 48, 49 are acted upon by the cleaning nozzles 47, 48, 49 along a partial area thereof.

15

rer orbital movement can be directed to the liquid discharge opening 19.

The flow connection between the axial bore 31 of the hollow shaft 30 and the through bores 43, 44, 45 of the spray arms 40, 41, 42 takes place via a radial bore 51 of the hollow shaft 30 and a connecting groove 52 which adjoins this in the flow direction and which is related to the circumferential direction Axis of rotation 35 extends only over a partial area, namely an angular area of approximately 120 °. This is particularly clear from Figure 1.

Pressurized cleaning liquid can be supplied to the surface cleaning head 10 via the connecting piece 33. The cleaning liquid flows through the axial bore 31, the radial bore 51 and the connecting groove 52 to the through bore 43, 44, 45 of the spray arms 40, 41, 42 and is then discharged from the nozzles 47, 48, 49. The nozzles 47, 48, 49 are only supplied with cleaning fluid when the respective spray arm 40, 41 or 42 is arranged in the region of the connecting groove 52. With such an alignment of the spray arm, the respective nozzle 47, 48 or 49 is aligned in the direction of the liquid discharge opening 19, so that a cleaning liquid jet can pass through the liquid discharge opening 19 and consequently the surface 22 to be cleaned is streaked by the cleaning liquid jet. If the respective spray arm 40, 41, 42 assumes a position outside the connecting groove 52, the cleaning liquid supply to the respective nozzle 47, 48, 49 is interrupted. This is the case when the respective nozzle 47, 48, 49 faces away from the liquid discharge opening 19. The cleaning liquid supply to the nozzles 47, 16 -

48, 49 thus only occurs non-uniformly when the nozzles are rotated, namely that nozzle is supplied with cleaning liquid in each case which is just facing the liquid discharge opening 19.

In the axial direction offset from the spray arms 40, 41, 42, the bearing bush 38, adjacent to the front wall 14, carries a mechanical cleaning element in the form of radially projecting cleaning bristles 54, which are held on the bearing bush 38 in a rotationally fixed manner and with their free-standing end regions reach through the liquid discharge opening 19 , so that by means of the cleaning bristles 54, which can be rotated together with the spray arms 40, 41, 42, the surface 22 to be cleaned can be machined to enhance the cleaning effect.

The cleaning liquid applied by the nozzles 47, 48, 49 to the surface 22 to be cleaned can be sucked off via the suction channel 27, that is to say the surface cleaning head 10 can be used as a spray extraction device, by removing the surface 22 to be cleaned by means of the nozzle 47, 48, 49 emitted cleaning liquid jet and the mechanical cleaning action of the bristle ring 20 and the cleaning bristles 54 can be cleaned, and then the liquid applied to the surface 22 can be sucked off again via the suction channel 27.

FIGS. 3, 4 and 5 schematically show a second embodiment of a surface cleaning head, which is denoted overall by reference numeral 60 and is largely identical in construction to the surface cleaning head 10 explained above with reference to FIGS. 1 and 2 Identical components are therefore used the same reference numerals as in Figures 1 and 2, in this regard reference is made to the above explanations to avoid repetition.

The surface cleaning head 60 comprises a hollow shaft 62 which is held in a rotationally fixed manner both on the rear wall 13 and on the front wall 14 and projects beyond the front wall 14. In its projecting end region, the hollow shaft 62 carries a cover plate 64 which can be rotated about the axis of rotation 35. The latter has a recess 65 which, by rotating the cover plate 34, can be aligned to an air supply opening 67 of the front wall 14. Air can enter the interior of the housing 12 via the recess 65 and the air supply opening 67. By rotating the cover plate 64, the air supply opening 67 can be covered in order to prevent the air supply.

Within the housing 12, the hollow shaft 62 of the surface cleaning head 60 carries a rotor 69 which, in accordance with the rotor 36 of the surface cleaning head 10 explained above, comprises three radially projecting spray arms 40, 41, 42, only the spray arms 40 and 42 being recognizable in FIG. The spray arms each carry two brake vanes 73, 74, which are fixed in a rotationally fixed manner on the respective spray arm and considerably increase the air resistance of the rotating spray arms, in particular when the air supply opening 67 is cleared from the cover plate 64. At the same time, an air cushion effect is achieved by means of the brake vanes 73, 74 when the air supply opening 67 is open, in such a way that an air flow is formed by air flowing into the housing 12 via the air supply opening 67 and via the liquid discharge opening 19 in the direction of the surface 22 to be cleaned from the housing 18

12 flows out. This air flow makes it easier to guide the surface cleaning head 60 along the surface to be cleaned.

4 and 5, the hollow shaft 62 is shown enlarged. It is particularly clear from this that an annular groove 76, 77 extends in the axial direction on both sides of the radial bore 51 and the connecting groove 52. The ring grooves 76, 77 are arranged at a small distance next to the connecting groove 52, preferably at a distance of about 0.5 mm to about 3 mm. Starting from the area of the connecting groove 52, pressurized cleaning liquid can spread over the entire circumference of the hollow shaft 62 via the annular grooves 76, 77, so that the pressure prevailing in the area of the connecting groove 52 is evenly distributed in the circumferential direction. The annular grooves 76, 77 thus enable pressure relief, by means of which a one-sided pressure load which prevails only in the area of the connecting groove 52 is avoided. A one-sided pressure load would result in increased stress on the slide bearing of the rotor 69.

At an axial distance from the annular grooves 76 and 77, the hollow shaft 62 each has an annular sealing groove 79, 80. A sealing element, preferably a piston ring 81, 82, is arranged on each of the sealing grooves 79, 80. The piston ring is preferably made of PEEK-based plastic, which enables the rotor 69 to rotate particularly smoothly.

FIGS. 6 and 7 schematically show a third embodiment of a surface cleaning head, which is denoted overall by reference number 90. The presentation is very schematic. To achieve a better one - 19 -

The hollow shaft used and the rotor of the surface cleaning head 90 were not shown in an overview in FIGS. 6 and 7. The surface cleaning head 90 is largely identical to that of the surface cleaning head 60 shown above with reference to FIGS. 3, 4 and 5. For identical components, the same reference numerals are therefore used in FIGS. 6 and 7 as in FIGS. 3 to 5. To avoid repetitions In this regard, reference is made to the above explanations.

In contrast to the surface cleaning heads 10 and 60 explained above, the surface cleaning head 90 has in its rear region two support wheels which are freely rotatable and rigidly connected to one another about a common axis of rotation 92, only one support wheel 93 being shown in FIGS. The support wheels 93 are each mounted on a bearing block 94 which is integrally formed on the rear wall 13 on the outside. The surface cleaning head 90 can be guided along the surface 22 to be cleaned in a simple manner by means of the support wheels 93.

Alternatively, skids can also be used instead of support wheels if, for example, a carpet is to be cleaned by means of the surface cleaning head 90.

The support wheels 93 are overlapped by an extension 96 formed on the outside of the rear wall 13, which carries at its free end a wiper lip 97 which can be applied to the surface 22 to be cleaned by tilting the surface cleaning head 90 about the axis of rotation 92. In a 20

6, the surface cleaning head 90 can be moved back and forth in the working direction 99 in order to clean the surface 22 by means of the bristle ring 20 and the cleaning liquid jet. The surface cleaning head 90 can then be transferred about the axis of rotation 92 into the second tilting position shown in FIG. 7, in which the wiping lip 97 wipes off the surface 22 and thus pushes the cleaning liquid applied to the surface 22 along it.

From the foregoing it is clear that by means of the surface cleaning heads 10, 60 and 90, a surface 22 can be cleaned in strips by the respective surface cleaning heads 10, 60, 90 being felt along the surface 22 to be cleaned, with a jet of cleaning liquid then always using a plurality of nozzles is directed onto the surface 22 when the nozzles face the liquid discharge opening 19 of the housing 12. The liquid discharge opening 19 is arranged in a region of the housing 12 that is positioned obliquely or perpendicular to the axis of rotation 35 of the nozzles.

Claims

- 21 PATENT CLAIMS

1. Surface cleaning head with a hood-shaped housing having a liquid discharge opening, in which at least one spray arm is mounted, freely rotatable about an axis of rotation, which carries a nozzle which rotates around the axis of rotation together with the spray arm when subjected to pressurized cleaning liquid, characterized in that that the liquid discharge opening (19) is arranged in a region of the housing (12) oriented obliquely or perpendicular to the axis of rotation (35), the surface to be cleaned being passed from the rotating nozzle (47, 48, 49) through the liquid discharge opening (19) (22) cleaning liquid jet covering the strip can be dispensed.

2. Surface cleaning head according to claim 1, characterized in that the nozzle (47, 48, 49) during its orbital movement about the axis of rotation (35) can be acted upon nonuniformly with cleaning liquid, the greatest application of cleaning liquid when the nozzle (47, 48, 49) is aligned. in the direction of the liquid discharge opening (19).

3. Surface cleaning head according to claim 2, characterized in that the nozzle via a first, the liquid discharge opening (19) facing portion of its circulating movement can be acted upon with a maximum amount of cleaning liquid, while it has a second portion of the liquid discharge opening (19) facing away from its circulation -

22

movement can be loaded with a minimal amount of cleaning fluid.

4. Surface cleaning head according to one of the preceding claims, characterized in that the surface cleaning head (10; 60; 90) has a plurality of spray arms (40, 41, 42) distributed in the circumferential direction, on each of which a nozzle (47, 48, 49) is held The nozzles (47, 48, 49) can be acted upon with more cleaning liquid during their circulation movement if they face the liquid discharge opening (19) than if they face away from the liquid discharge opening (19).

5. Surface cleaning head according to claim 4, characterized in that the surface cleaning head (10; 60; 90) has three spray arms (40, 41, 42) arranged uniformly distributed in the circumferential direction with a nozzle (47, 48, 49), the nozzles ( 47, 48, 49) can each be acted upon with more cleaning fluid over a partial area of at least about 120 ° of their orbital motion than over the remaining area of their orbital motion.

6. Surface cleaning head according to claim 5, characterized in that the nozzles (47, 48, 49) can each be acted upon over a partial area of their orbital movement of approximately 140 ° with more cleaning liquid than over the remaining area of their orbital movement.

23 -

7. Surface cleaning head according to one of the preceding claims, characterized in that the at least one spray arm (40, 41, 42) is rotatably held on a hollow shaft (30; 62), the hollow shaft (30; 62) having an axial bore (31) which can be brought into flow connection with a through hole (43, 44, 45) of the spray arm (40, 41, 42) via a connecting groove (52) running in the circumferential direction only over a partial area.

8. Surface cleaning head according to claim 7, characterized in that the spray arm (40, 41, 42) on a the hollow shaft (30; 62) surrounding the bearing element (38) is fixed.

9. Surface cleaning head according to claim 8, characterized in that the bearing element (38) forms a plain bearing.

10. Surface cleaning head according to claim 9, characterized in that at least the sliding surface of the bearing element (38) consists of plastic based on a PEEK material.

11. Surface cleaning head according to claim 7, 8, 9 or 10, characterized in that the hollow shaft (62) is axially offset from the connecting groove (52) by at least one annular groove (76, 77).

12. Surface cleaning head according to claim 11, characterized in that the distance of the at least one annular groove (76, 77) to the connecting groove (52) is about 0.5 mm to about 3 mm.

13. Surface cleaning head according to claim 11 or 12, characterized in that an annular groove (76, 77) is arranged in the axial direction on both sides of the connecting groove (52).

14. Surface cleaning head according to one of claims 7 to 13, characterized in that the hollow shaft (62) axially offset to the connecting groove (52) carries at least one piston ring (81, 82).

15. Surface cleaning head according to claim 14, characterized in that the at least one piston ring (81, 82) is made of plastic based on a PEEK material.

16. Surface cleaning head according to one of the preceding claims, characterized in that a brake wing (73, 74) is arranged on at least one spray arm (40, 41, 42).

17. Surface cleaning head according to claim 16, characterized in that the housing (12) adjacent to the brake wing (73, 74) has at least one air supply opening (67).

18. Surface cleaning head according to claim 17, characterized in that the at least one air supply opening (67) can be optionally released and closed.

- 25th

19. Surface cleaning head according to one of the preceding claims, characterized in that the surface cleaning head (10) comprises a mechanical cleaning element which extends around the at least one spray arm (40, 41, 42) and passes through the liquid discharge opening (19).

20. Surface cleaning head according to one of the preceding claims, characterized in that the liquid discharge opening (19) is at least partially surrounded in the circumferential direction by a flexible splash protection element (20).

21. A surface cleaning head according to claim 20, characterized in that the splash protection element is designed as a bristle strip (20) surrounding the liquid discharge opening (19) or as a rubber lip.

22. Surface cleaning head according to one of claims 7 to 21, characterized in that the hollow shaft (30; 62) on an in the use position of the surface cleaning head (10; 60; 90) obliquely or perpendicular to the surface to be cleaned (22) alignable housing wall (13 ) is held.

23. Surface cleaning head according to claim 22, characterized in that the hollow shaft (30; 62) is aligned perpendicular to the housing wall (13).

24. Surface cleaning head according to one of the preceding claims, characterized in that the surface cleaning head (10; 60; 90) one

26

has wiping lip (25; 97) which can be placed on the surface (22) to be cleaned.

25. Surface cleaning head according to one of the preceding claims, characterized in that the surface cleaning head (90) has at least one rolling element (93) for supporting the surface cleaning head (90) on the surface to be cleaned (22).

26. Surface cleaning head according to one of the preceding claims, characterized in that the surface cleaning head (10) has a suction channel (27) which can be connected to a vacuum source for receiving cleaning liquid.