Floor cleaning machine with a pivotable suction foot

Abstract

A floor cleaning machine (1) is shown and described, comprising a frame (3), a suction foot (25) designed to be guided over a floor surface (7) to be cleaned and to collect cleaning fluid from the floor surface (7), the suction foot (25) being attached to a support arm (39) pivotably connected to the frame (3) about a first pivot axis (41), the support arm (39) being pivotable between a suction position in which the suction foot (25) is in contact with the floor surface (7) to be cleaned, so that it can collect cleaning fluid from the floor surface (7), and a raised position in which the suction foot (25) is spaced away from the floor surface (7), a preloading element (43) being arranged between the frame (3) and the support arm (39), which is configured to apply a first preload force (73) to the support arm (39) in the suction position. to exercise,which pushes the suction foot (25) towards the floor surface (7) to be cleaned, in the raised position exerts a second preload force (75) on the holding arm (39), which pushes the suction foot (25) towards the floor surface (7) to be cleaned, and wherein the first preload force (73) is less in magnitude than the second preload force (75).

Description

[0001] The present invention relates to a floor cleaning machine comprising a frame, a chassis arranged on the frame for moving the floor cleaning machine over a floor surface to be cleaned, and a suction foot designed to be guided over the floor surface to be cleaned and to pick up cleaning fluid from the floor surface to be cleaned, wherein the floor cleaning machine is designed to be moved in a forward direction over the floor surface to be cleaned during cleaning operation, wherein the suction foot is arranged in a forward direction at a rear end of the floor cleaning machine.

[0002] Floor cleaning machines with a suction foot, which can be moved across a floor surface to be cleaned, are known from the prior art. These machines include a cleaning unit with one or more driven brush elements designed to engage the floor surface and loosen dirt. Furthermore, an application device is provided for delivering cleaning fluid to the brush elements, thus improving dirt removal. The dirt loosened from the floor surface, as well as the cleaning fluid, can be sucked up by a suction foot attached to the floor cleaning machine by means of a vacuum and conveyed into a dirty water container. To maximize the amount of dirty water the suction foot can collect, it is wider than the floor cleaning machine itself.

[0003] With these types of floor cleaning machines, it has proven problematic to reliably guide the suction foot across the floor surface to be cleaned, ensuring the dirty liquid is effectively vacuumed up. It is particularly important to ensure that the suction foot is always pressed firmly against the floor surface with sufficient pressure, as insufficient pressure or excessive distance from the floor surface can prevent the dirty liquid from being reliably collected. Excessive pressure can prevent the dirty liquid from entering the suction foot and instead displace it. Furthermore, excessive pressure leads to significant wear on the sealing lips that define the suction foot's collection area and rest against the floor surface.

[0004] Typically, the suction foot of conventional floor cleaning machines can be raised from the floor surface via a swivel mechanism. This allows the suction foot to be pivoted between a suction position, where it is in contact with the floor surface to pick up cleaning fluid, and a raised position, where it is detached from the floor surface. Swiveling the suction foot is particularly necessary when transporting the floor cleaning machine. Raising the suction foot is also necessary when it is not in use to prevent unnecessary wear, for example, on the sealing lips of the suction foot that are in contact with the floor surface.

[0005] In known swivel mechanisms, the suction foot is pre-tensioned in both the suction position and the raised position by a pre-tensioning element. The pre-tensioning element is intended to ensure that the suction foot remains in the respective position without swiveling back on its own, thus eliminating the need for additional locking elements to hold the suction foot in place. A disadvantage of these swivel mechanisms is that either only one pre-tensioning element is used for the raised position, meaning the suction foot is pressed onto the floor surface to be cleaned solely by gravity, or two pre-tensioning elements are required to apply the desired contact pressure to the floor surface.

[0006] Based on the prior art, the object of the present invention is therefore to provide a floor cleaning machine of the type mentioned at the outset in which the suction foot can be pivoted in a particularly simple and reliable manner, wherein the suction foot is held in the raised position and in the suction position with a predetermined preload.

[0007] According to a first aspect of the invention, the aforementioned problem is solved by a floor cleaning machine with the features of claim 1. The floor cleaning machine has a frame and a chassis arranged on the frame for moving the floor cleaning machine over a floor surface to be cleaned. Furthermore, the floor cleaning machine has a cleaning element arrangement with at least one, preferably driven, cleaning element configured to engage with the floor surface to be cleaned, and means for applying cleaning fluid to the floor surface to be cleaned. The floor cleaning machine has a suction foot configured to be guided over the floor surface to be cleaned and to pick up cleaning fluid from the floor surface to be cleaned.The floor cleaning machine is designed to be moved forward across the floor surface during cleaning, with the suction foot positioned at the rear end of the machine. The suction foot is attached to a support arm that is pivotally connected to the frame about a first pivot axis. The support arm can be pivoted between a suction position, in which the suction foot is in contact with the floor surface so that it can pick up cleaning fluid, and a raised position, in which the suction foot is detached from the floor surface.A preloading element is arranged between the frame and the support arm. In the suction position, this element is designed to exert a first preload force on the support arm, pushing the suction foot towards the floor surface to be cleaned. In the raised position, it exerts a second preload force on the support arm, pushing the suction foot away from the floor surface to be cleaned. The first preload force is less than the second preload force.

[0008] The floor cleaning machine comprises a cleaning element arrangement with at least one, preferably driven, cleaning element. The cleaning element is designed to engage with the floor surface to be cleaned. For example, the cleaning element can be a rotating, driven brush, in which case the engagement elements are bristles whose free ends engage with the floor surface to be cleaned. However, it is equally conceivable that the cleaning element is a so-called pad, in which the engagement element is formed by a flat material provided on the pad, the surface of which comes into contact with the floor surface to be cleaned. The present invention is not limited to these two examples, however, and any other form of cleaning element can also be used.

[0009] In a preferred embodiment, the suction foot has a base from which a front and a rear sealing lip extend downwards, running essentially parallel to each other and, during suction operation when the suction foot is moved over the floor surface to be cleaned, essentially perpendicular to them, so that a suction chamber is formed between the sealing lips and below the base. The base has a connection through which the suction chamber can be connected to the vacuumed dirty water tank of the floor cleaning machine, so that dirty water present on the floor surface to be cleaned can be suctioned out.

[0010] The suction foot is attached to a support arm that is pivotably connected to the frame about a first pivot axis. The term "frame" refers to the stationary part of the floor cleaning machine that is connected to the chassis. The frame can be made of steel, aluminum, or a composite material. Additional components, in particular a housing, covers, cross and longitudinal struts, and electronic components, can be attached to the frame. The support arm can be integral with the suction foot or a separate component connected to the suction foot via fasteners. Preferably, the support arm is made of the same material as the frame of the floor cleaning machine.

[0011] Preferably, the first pivot axis is arranged perpendicular to a longitudinal axis of the floor cleaning machine. Because the suction foot is pivotally connected to the frame, it can adapt to the floor surface, particularly when the floor cleaning machine is moved over an inclined or curved floor. The first pivot axis being parallel to the floor surface ensures particularly good contact between the suction foot and the floor, resulting in improved cleaning performance and reliable removal of dirty water from the floor.

[0012] The support arm can be swivelled between a suction position, in which the suction foot is in contact with the floor surface to be cleaned, allowing it to pick up cleaning fluid, and a raised position, in which the suction foot is detached from the floor surface. In the suction position, the suction foot is moved across the floor surface to extract the dirty fluid, resulting in a more even cleaning. In the raised position, the suction foot is positioned so that no dirty fluid is drawn from the floor surface. The raised position makes transporting the floor cleaning machine particularly easy and minimizes the risk of damage to the suction foot as well as increased wear and tear.

[0013] A pre-tensioning element is positioned between the frame and the support arm. In the suction position, this element applies a first pre-tensioning force to the support arm, pressing the suction foot towards the floor surface to be cleaned. In the raised position, it applies a second pre-tensioning force to the support arm, pressing the suction foot away from the floor surface. This pre-tensioning element allows the suction foot to be held in the respective position without the need for separate locking mechanisms, thus enabling particularly easy pivoting of the suction foot between the raised and suction positions. Specifically, the suction foot can be held under the pre-tensioning force. A defined pre-tensioning force allows the suction foot to be pressed against the floor surface with a desired force, resulting in a reliable and even cleaning outcome.Because the pretensioning element can exert a first and a second pretensioning force on the holding arm, the suction foot can be held in both positions by a single pretensioning element. This allows for a simpler design and a reduction in the number of components of the floor cleaning machine.

[0014] The first pre-tensioning force is lower in magnitude than the second. This ensures that, with the same pre-tensioning element, the suction foot is pressed against the floor surface to be cleaned with less force in the suction position than in the raised position, where it is pressed away from the floor surface with greater force. The higher second pre-tensioning force reliably holds the suction foot in the raised position, reducing the risk of it swinging into the suction position on its own. Simultaneously, the lower first pre-tensioning force allows the suction foot to be pressed against the floor surface with the desired force, resulting in a reliable and even cleaning performance.

[0015] In summary, it can be stated that a floor cleaning machine is provided in which the suction foot can be pivoted in a particularly simple and reliable manner, with the suction foot being held in the raised position and in the suction position with a predetermined preload.

[0016] In one embodiment, the preload element is designed as a compression spring element extending along a longitudinal axis between a first end and a second end, with the first end supported on the support arm and the second end supported on the frame. In both the suction position and the raised position, the longitudinal axis runs at an angle to the floor surface, so that the preload force is divided into two components. A first component acts parallel to the floor surface, and a second component acts perpendicular to the floor surface, the second component representing the preload force exerted by the preload element on the support arm. The compression spring element defines the first and second preload forces acting between the support arm and the frame. This allows a sufficiently large preload force to be generated within the relatively small installation space between the support arm and the frame.This results in a particularly compact design.

[0017] In a preferred embodiment, the first end is pivotably mounted on the support arm about a second pivot axis parallel to the first pivot axis. A pivot arm is provided which is pivotably mounted on the frame about a third pivot axis parallel to the first pivot axis. The second end is pivotally mounted on the pivot arm about a fourth pivot axis spaced apart from the third pivot axis, the fourth pivot axis being parallel to the first pivot axis. The pivot arm allows the pretensioning element to pivot about a dead center, enabling the pretensioning element to exert the first pretensioning force on the first end, acting in the direction of the floor surface to be cleaned, and the second pretensioning force, acting in the opposite direction to the floor surface to be cleaned.The dead center is defined as the point in the pivot range of the retaining arm where the first and second preload forces cancel each other out. Preferably, the first and second preload forces are zero at the dead center. Furthermore, the dead center is defined as the point where the longitudinal axis of the spring element is parallel to a plane passing through the first and second pivot axes. This increases the flexibility and adaptability of the preload element in application by allowing different preload forces to be applied to the suction cup.

[0018] In one embodiment, in the raised position, the fourth pivot axis, viewed perpendicular to the floor surface to be cleaned, is arranged below a first plane extending through the first and second pivot axes. In the suction position, the fourth pivot axis, viewed perpendicular to the floor surface to be cleaned, is arranged above the first plane extending through the first and second pivot axes. In other words, the first plane extends through the first and second pivot axes, with the fourth pivot axis, viewed perpendicular to the floor surface to be cleaned, being arranged below the first plane in the raised position. In the suction position, however, the fourth pivot axis is arranged above the first plane. The dead center can be defined by the first plane such that the longitudinal axis at the dead center extends parallel to the first plane.The longitudinal axis of the preload element and the first plane correspond to each other at the dead center. By arranging the fourth pivot axis above and below the first plane, the preload force acting on the holding arm can be reversed, so that the first preload force in the extraction position and the second preload force in the raised position can act on the holding arm in different directions.

[0019] In one embodiment, the angle between the first plane and a second plane extending through the second and fourth pivot axes is greater in the raised position than in the lowered position. The second plane runs at an angle to the floor surface in both the lowered and raised positions. As already explained regarding the pretensioning element, the pretensioning force is divided into two components: one parallel to the floor surface and one perpendicular to it. With respect to the first and second planes, the component of the pretensioning force acting perpendicular to the floor surface, the first and second pretensioning forces, can be determined by trigonometry using the angle between the first and second planes. Due to the smaller angle in the lowered position, a smaller force component perpendicular to the floor surface is achieved. This results in a lower overall force acting perpendicular to the floor surface.If the angle is determined with reference to the first plane, the angle between the first and second planes in the suction position can become negative with reference to the first plane after the dead center point has been overcome, since the two planes move in opposite directions and are therefore oriented in opposite directions after the dead center point. This allows for a reversal of the perpendicular component of the preload force, enabling effective adjustment of the force direction and magnitude according to the requirements of the respective position of the suction foot.

[0020] In one embodiment, a first stop element is arranged on the frame. This stop element is designed to make contact with the swivel arm in the suction position and prevent the fourth pivot axis of the swivel arm from pivoting away from the floor surface to be cleaned. In the suction position, the first stop element limits the swivel range of the swivel arm so that it does not pivot further upwards away from the floor surface to be cleaned. This ensures that the initial preload force with which the suction foot is pressed against the floor surface to be cleaned remains limited, as the first stop element prevents the angle between the aforementioned first plane and the aforementioned second plane from increasing arbitrarily, which would otherwise lead to an increase in the initial preload force.

[0021] In one embodiment, a second stop element is arranged on the frame. This stop element is designed to make contact with the support arm in the raised position and prevent the support arm from pivoting beyond the raised position and away from the floor surface to be cleaned. The second stop element allows the pivoting range to the raised position to be limited to a predetermined area, preventing the suction foot from pivoting beyond this predefined range. This ensures that the suction foot is held in the raised position with a predetermined second preload force, and the second stop element prevents this force from increasing due to further pivoting. Furthermore, this reduces the risk of damage to the suction foot or the floor cleaning machine caused by excessive pivoting of the suction foot.

[0022] In one embodiment, the support arm is pivotably connected to the frame at a first end section and has an actuating element at an end section opposite the first end section. The actuating element can be designed such that a user can actuate it with a foot. For example, the actuating element can have a pedal for this purpose. The actuating element can be made of a material that has a higher coefficient of friction than the material of the support arm, thus providing the actuating element with greater grip or adhesion.

[0023] In one embodiment, a first support bolt extending along the second pivot axis is provided on the support arm, wherein the pivot arm has a second support bolt extending along the fourth pivot axis, and wherein the compression spring element is supported at its first end on the first support bolt and at its second end on the second support bolt. A support bolt can be a component that serves to hold or guide the compression spring element in a defined position, while allowing rotation or positioning about the second and fourth pivot axes. On the one hand, the support bolts enable precise and stable fastening and guidance of the compression spring element, thereby ensuring correct alignment and function of the spring. On the other hand, the support bolts help to distribute mechanical loads evenly across the support arm and the frame, which increases durability and reliability.

[0024] In one embodiment, the swivel arm has a first leg and a second leg, with the second support bolt extending between the first and second legs. This arrangement allows the support bolt to serve as a pivot point around which the two legs can perform an opposing rotational movement. The two legs enable one of them to be used as abutments against the first stop element, which defines and controls the movement limits of the swivel arm.

[0025] In one embodiment, the compression spring element comprises a compression spring and a first stop piece arranged at the first end of the compression spring element, and a second stop piece arranged at the second end of the compression element. The compression spring extends between and is supported by the first and second stop pieces, with the first stop piece bearing against the first support bolt and the second stop piece bearing against the second support bolt. A stop piece can be understood as a mechanical component that serves to limit the movement of the compression spring.The stop pieces act as holding points, preventing the compression spring from detaching from the support bolts. The stop pieces at both ends of the compression spring ensure optimal support. They effectively absorb and transfer the forces acting during compression and expansion. This results in a longer service life for the compression spring and increased safety and efficiency of the support arm.

[0026] In one embodiment, the first stop piece has first arms extending along the longitudinal axis towards the second stop piece, and the second stop piece has second arms extending along the longitudinal axis towards the first stop piece. The first and second arms are spaced apart around the longitudinal axis, such that a first arm is positioned between two second arms. The stop pieces and arms thus serve as guides for the compression spring element, interlocking with one another. The arms extend within the cross-section of the compression spring, i.e., inside the spring. This arrangement provides effective guidance for the compression spring element, ensuring that it can pivot about the second and fourth pivot axes without disengaging from the support bolts.By positioning the first arm between the second arms, the arms interlock along their extension direction, thus providing a guide that can compensate for differences in the length of the compression spring, even if the two stop pieces move apart. This prevents the compression spring element from slipping or twisting during actuation and contributes to the stability and accuracy of the movements.

[0027] The present invention will now be explained with reference to a drawing showing only one preferred embodiment, in which Figures 1 and 2 show schematic views of an embodiment of a floor cleaning machine according to the invention, Figure 3 shows a schematic partial view of the suction foot of the floor cleaning machine according to the invention. Figure 1In the suction position, Figure 4 shows a schematic partial view of the suction foot of the floor cleaning machine according to the invention. Figure 2 In the raised position, Figures 5a and 5b show schematic partial views of the holding arm of the exemplary embodiment of the floor cleaning machine according to the invention. Figures 1 to 4 Figures 6 and 7 show schematic partial views of the holding arm of the exemplary embodiment of the floor cleaning machine from the Figures 1 to 4 , 5a and 5b show.

[0028] Figure 1 and 2Figure 1 shows a schematic view of an embodiment of a floor cleaning machine 1 according to the invention. The floor cleaning machine 1 has a frame 3 and a chassis 5 arranged on the frame 3 for moving the floor cleaning machine 1 over a floor surface 7 to be cleaned. The frame 3 is understood to be the stationary part of the floor cleaning machine 1 that is connected to the chassis 5. The frame 3 can, for example, be made of a steel or aluminum construction or of a composite material.

[0029] Furthermore, the floor cleaning machine 1 has a cleaning element arrangement 9 with a cleaning element 11, wherein the cleaning element 11 is designed to engage with the floor surface 7 to be cleaned. For example, the cleaning element 11 can be a brush, in which case the engagement elements are bristles whose free ends engage with the floor surface 7 to be cleaned. However, it is equally conceivable that the cleaning element 11 is a so-called pad, in which the engagement element is formed by a flat material provided on the pad, the surface of which comes into contact with the floor surface 7 to be cleaned.

[0030] The floor cleaning machine 1 has a housing 13 for enclosing the floor cleaning machine 1. The housing 13 can accommodate, among other things, a fresh water tank for receiving fresh water and a dirty water tank for receiving dirty water.

[0031] The floor cleaning machine 1 has a guide handle assembly 15, which allows the user to guide the floor cleaning machine 1 and which, viewed in the forward direction, is located at the rear of the floor cleaning machine 1. The guide handle assembly 15 serves as a support by which the user can hold, control, and steer the floor cleaning machine 1. The placement of the guide handle assembly 15 at the rear contributes to more precise steering with less effort. The guide handle assembly 15 can be ergonomically shaped, resulting in improved comfort and reduced physical strain during operation, which is particularly advantageous during prolonged use of the floor cleaning machine 1.

[0032] The chassis 5 has a first chassis axle 17 and a second chassis axle 19, wherein a first roller unit 21 in the form of two rollers spaced apart along the first chassis axle 17 is arranged on the first chassis axle 17 and a second roller unit 23 in the form of a swivel roller is arranged on the second chassis axle 19. The rollers of the first roller unit 21 and the second roller unit 23 are configured to roll over the floor surface 7 to be cleaned.

[0033] The floor cleaning machine 1 has a suction foot 25. In the present embodiment, the suction foot 25 has first and second wheels 27, 27', with the first wheels 27 being arranged at the front end of the suction foot 25 as viewed in the forward direction of travel of the floor cleaning machine 1, while the second wheels 27' are mounted at its rear end. The wheels 27, 27' are designed to roll over the floor surface 7 to be cleaned, and their contact points with the floor surface 7 define a wheel plane 29. During cleaning operation of the floor cleaning machine 1, the wheel plane 29 runs parallel to the floor surface 7 to be cleaned, so that a predefined and uniform distance between the suction foot 25 and the floor surface 7 to be cleaned and a uniform cleaning result can be achieved.

[0034] The floor cleaning machine 1 is designed to be moved forward in a cleaning direction over the floor surface 7 to be cleaned, with the suction foot 25 being arranged at a rear end of the floor cleaning machine 1 when viewed in the forward direction. The suction foot 25 is designed to be guided over the floor surface 7 to be cleaned and to collect dirty liquid from the floor surface 7.

[0035] The suction foot 25 has a base 31, from which, as in the Figures 3 and 4As shown, a front sealing lip 33 and a rear sealing lip 35 extend downwards, essentially parallel to each other and, in suction operation when the suction foot 25 is moved over the floor surface 7 to be cleaned, essentially perpendicular to them, so that a suction chamber 37 is formed between the sealing lips 33, 35 and below the base 31. The base 31 has a connection through which the suction chamber 37 can be connected to the vacuumed dirty water tank of the floor cleaning machine 1, so that dirty water located on the floor surface 7 to be cleaned can be suctioned out.

[0036] The suction foot 25 is attached to a support arm 39, which is pivotably connected to the frame 3 about a first pivot axis 41. The support arm 39 can be integral with the suction foot 25 or, as in the present embodiment, designed as a separate component that is connected to the suction foot 25 via fasteners. Preferably, the support arm 39 is made of the same material as the frame 3 of the floor cleaning machine 1.

[0037] The first pivot axis 41 is arranged perpendicular to a longitudinal axis of the floor cleaning machine 1. Because the suction foot 25 is pivotably connected to the frame 3, it can adapt to the floor surface 7, particularly when the floor cleaning machine 1 is moved over an inclined or curved floor surface 7. The first pivot axis 41, which is parallel to the floor surface 7, ensures particularly good contact between the suction foot 25 and the floor surface 7, resulting in improved cleaning performance and reliable removal of dirty water from the floor surface 7.

[0038] The support arm 39 can be pivoted between a suction position, in which the suction foot 25 is in contact with the floor surface 7 to be cleaned, so that it can pick up dirty liquid from the floor surface 7, and a raised position, in which the suction foot 25 is spaced away from the floor surface 7 to be cleaned. In the suction position, the suction foot 25 is, as in Figure 1 The wheels 27, 27' are shown moving across the floor surface 7 to be cleaned, allowing the dirty liquid to be suctioned from the floor surface 7, resulting in a uniform cleaning outcome. The raised position of the suction foot 25 is shown below. Figure 2 explained in more detail.

[0039] Figure 2Figure 1 shows a schematic view of an embodiment of a floor cleaning machine 1 according to the invention in the raised position. In the raised position, the suction foot 25 is spaced from the floor surface 7 in such a way that the wheels 27, 27' are spaced from the floor surface 7 to be cleaned, so that no dirty liquid is sucked up from the floor surface 7. The raised position allows the floor cleaning machine 1 to be transported while minimizing the risk of damage to the suction foot 25 and increased wear of the suction foot 25. The construction of the support arm 39 is described below with reference to the Figure 3 described.

[0040] Figure 3 shows a schematic partial view of the suction foot 25 in the suction position of the floor cleaning machine 1 according to the invention. Figure 1A preload element 43 is arranged between the frame 3 and the support arm 39, and is configured to exert a preload force on the support arm 39. The preload element 43 is designed as a compression spring element that extends along a longitudinal axis 49 between a first end 45 and a second end 47, with the first end 45 bearing against the support arm 39 and the second end 47 bearing against the frame 3. In the extraction position, the longitudinal axis 49 runs at an angle to the base surface 7, so that the preload force is divided into two components. A first force component acts parallel to the base surface 7, and a second force component acts perpendicular to the base surface 7, the second force component being the preload force exerted by the preload element on the support arm 39. The compression spring element defines the preload force acting between the support arm 39 and the frame 3.The compression spring element allows a sufficiently large preload force to be generated in the relatively small installation space between the retaining arm 39 and the frame 3. This results in a particularly compact design.

[0041] The retaining arm 39 is connected to the frame 3 at a first end section and has an actuating element 51 at a second end section opposite the first end section. The actuating element 51 can be designed such that a user can actuate it with a foot. For example, the actuating element 51 can have a pedal for this purpose. The actuating element 51 can be made of a material that has a higher coefficient of friction than the material of the retaining arm 39, thus giving the actuating element 51 greater grip or adhesion.

[0042] In the suction position of the suction foot 25, the holding arm 39 is pivoted about the first pivot axis 41 such that the wheel plane 29 and the base surface 7 correspond to each other, or the wheel plane 29 is in contact with the base surface 7 and the wheels 27, 27' roll over the base surface 7. A first stop element 53 is arranged on the frame 3, the function of which will be explained below.

[0043] Figure 4 shows a schematic partial view of the suction foot 25 of the floor cleaning machine 1 according to the invention. Figure 2 in the raised position. In the raised position of the suction foot 25, the retaining arm 39 is pivoted about the first pivot axis 41 such that the wheel plane 29 is spaced away from the floor surface 7, so that no dirty liquid can be suctioned from the floor surface 7.

[0044] A second stop element 55 is arranged on the frame 3. This stop element is designed to contact the holding arm 39 in the raised position and prevent the holding arm 39 from pivoting beyond the raised position and away from the floor surface 7 to be cleaned. The second stop element 55 limits the pivot range to a predetermined area, preventing the suction foot 25 from pivoting beyond the raised position. This ensures that the suction foot 25 is held in the raised position with a predetermined preload force, and the second stop element 55 prevents this preload force from increasing due to further pivoting. Furthermore, this reduces the risk of damage to the suction foot 25 or the floor cleaning machine 1 caused by excessive pivoting of the suction foot 25.

[0045] The swivel mechanism of the support arm 39 is described below using the Figures 5a to 7 explained.

[0046] Figures 5a and 5b schematic partial views of the holding arm 39 of the exemplary embodiment of the floor cleaning machine 1 according to the invention are shown in the Figures 1 to 4 , wherein the retaining arm 39 in Figure 5a in the extraction position and in Figure 5b shown in the raised position. As in, among others, Figures 5a and 5bAs shown, the first end 45 is pivotably mounted on the support arm 39 about a second pivot axis 57, which runs parallel to the first pivot axis 41. A pivot arm 59 is provided, which is pivotably mounted on the frame 3 about a third pivot axis 61, which runs parallel to the first pivot axis 41. The second end 47 is pivotally mounted on the pivot arm 59 about a fourth pivot axis 63, spaced apart from the third pivot axis 61. The fourth pivot axis 63 runs parallel to the first pivot axis 41. The pivot arm 59 allows the pretensioning element 43 to pivot about a dead center, so that the pretensioning element 43 assumes a position as shown in Figure 6 shown, first preload force on the first end 45, which is in the direction of the floor surface to be cleaned 7, and one, as in Figure 7As shown, a second preload force can be exerted, acting in the opposite direction to the floor surface 7 to be cleaned. The dead center is defined as the point in the pivot range of the retaining arm 39 where the first and second preload forces cancel each other out. Preferably, the first and second preload forces are equal to zero at the dead center. Furthermore, the dead center is defined as the point where the longitudinal axis 49 of the compression spring element is parallel to a plane passing through the first pivot axis 41 and the second pivot axis 57. This increases the flexibility and adaptability of the preload element 43 in application by allowing different preload forces to be exerted on the suction foot 25.The retaining arm 39 is provided with a first support bolt 65 extending along the second pivot axis 55, the pivot arm 59 having a second support bolt 67 extending along the fourth pivot axis 63, and the preload element 43 being supported at its first end 45 on the first support bolt 65 and at its second end 47 on the second support bolt 67. A support bolt 65, 67 can be a component that serves to hold or guide the preload element 43 in a defined position, while allowing rotation or positioning about the second and fourth pivot axes 57, 63. The support bolts 65, 67 enable precise and stable fastening and guidance of the preload element 43, thereby ensuring correct alignment and function of the spring.Secondly, the support bolts 65, 67 help to distribute mechanical load evenly on the support arm 39 and the frame 3, which increases durability and reliability.

[0047] The swivel arm 59 has a first leg 69 and a second leg 71, with the second support bolt 67 extending between the first and second legs 69, 71. This arrangement allows the second support bolt 67 to serve as a pivot point around which the two legs 69, 71 can perform an opposing rotational movement. The two legs 69, 71 enable one of them to come into contact with the first stop element 53, which defines the movement limits of the swivel arm. The arrangement of the swivel arm 59 and the preload element 43 is described below. Figure 6 and 7 explained in more detail.

[0048] Figure 6 and 7schematic partial views of the holding arm 39 of the exemplary embodiment of the floor cleaning machine 1 are shown from the Figures 1 to 4 , 5a and 5b The pre-tensioning element 43 is set up in the extraction position, as in Figure 6 shown to exert a first preload force 73 on the holding arm 39, which pushes the suction foot 25 towards the floor surface 7 to be cleaned, and in the raised position, as in Figure 7As shown, a second preload force 75 is applied to the holding arm 39, which pushes the suction foot 25 away from the floor surface 7 to be cleaned. The preload element 43 allows the suction foot 25 to be held in the respective position without the need for separate locking elements, thus enabling particularly easy pivoting of the suction foot 25 between the raised position and the suction position. In particular, the suction foot 25 can be held under the preload force 73, 75. A defined preload force allows the suction foot 25 to be pressed against the floor surface 7 to be cleaned with a desired force, resulting in a reliable and uniform cleaning outcome. Because the preload element 43 can exert a first preload force 73 and a second preload force 75 on the holding arm 39, the suction foot 25 can be held in both positions by a single preload element 43.This allows for a simpler design and a reduction in the number of components of the floor cleaning machine 1.

[0049] The first preload force 73 is lower in magnitude than the second preload force 75. This ensures that the suction foot 25, with the same preload element 43, is pressed against the floor surface 7 to be cleaned with a lower preload force in the suction position than in the raised position, where the suction foot 25 is pressed away from the floor surface 7 with a greater preload force. The higher second preload force 75 ensures that the suction foot 25 can be reliably held in the raised position, reducing the risk of it pivoting into the suction position on its own. Simultaneously, the lower first preload force 73 allows the suction foot 25 to be pressed against the floor surface 7 with the desired force, resulting in a reliable and uniform cleaning outcome and ensuring that the suction foot 25 remains in contact with the floor surface 7.

[0050] The preload element 43 has a first stop piece 77 arranged at the first end 45 and a second stop piece 79 arranged at the second end 47, wherein the preload element 43 extends between the first stop piece 77 and the second stop piece 79 and is supported by them, and wherein the first stop piece 77 bears against the first support bolt 65 and the second stop piece 79 bears against the second support bolt 67. The preload element 43 extends between the first and second stop pieces 77, 79 and is supported by them. A stop piece can be understood as a mechanical component that serves to limit the movement of the preload element 43. The stop pieces 77, 79 can act as restraint points that prevent the preload element 43 from being released from the support bolts 65, 67.The stop pieces 77, 79 at both ends 45, 47 of the preload element 43 provide optimal support for the preload element 43. The stop pieces 77, 79 ensure that the forces acting during the compression and expansion of the preload element 43 are effectively absorbed and transmitted. This results in a longer service life for the preload element 43 and increased safety and efficiency of the retaining arm 39.

[0051] The first stop piece 77 has first arms 81 extending along the longitudinal axis 49 towards the second stop piece 79, and the second stop piece 79 has second arms 83 extending along the longitudinal axis 49 towards the first stop piece 77, wherein the first and second arms 81, 83 are spaced apart about the longitudinal axis 49, such that a first arm 81 is arranged between two second arms 83.

[0052] The stop pieces 77, 79 and the arms 81, 83 therefore serve as guides for the pretensioning element 43, which interlock.

[0053] The arms 81, 83 extend within the cross-section of the preload element 43, i.e., inside the compression spring. This arrangement provides effective guidance for the preload element 43, ensuring that it can pivot about the second and fourth pivot axes 57, 63 without disengaging from the support bolts 65, 67. Because the first arm 81 is positioned between the second arms 83, and vice versa, the arms 81, 83 interlock along their extension direction, thus providing guidance that can compensate for differences in the compression spring's length, even when the two stop pieces 81, 83 move apart. This prevents the preload element 43 from slipping or twisting during actuation and contributes to the stability and accuracy of the movements.

[0054] In the raised position, the fourth pivot axis 63, viewed perpendicular to the floor surface 7 to be cleaned, is arranged below a first plane 85 extending through the first and second pivot axes 41, 57 (see Fig. 7 ), and in the suction position the fourth pivot axis 63 is arranged perpendicular to the floor surface 7 to be cleaned above the first level 85 (see Fig. 6), which extends through the first and second pivot axes 41, 57. In other words, the first plane 85 extends through the first and second pivot axes 41, 57, with the fourth pivot axis 63, viewed perpendicular to the floor surface 7 to be cleaned, being located below the first plane 85 in the raised position. In the suction position, however, the fourth pivot axis 63 is located above the first plane 85. The dead center can be defined by the first plane 85 such that the longitudinal axis 49 extends parallel to the first plane 85 at the dead center. By arranging the fourth pivot axis 63 above and below the first plane 85, the preload force acting on the holding arm 39 can be reversed, so that the first preload force 73 in the suction position and the second preload force 75 in the raised position can act on the holding arm 39 in different directions.

[0055] Between the first plane 85 and a second plane 87 extending through the second pivot axis 57 and the fourth pivot axis 63, the angle is larger in the raised position than in the lowered position. The second plane 87 runs at an angle to the base surface 7 in both the lowered and raised positions. As already explained for the prestressing element 43, the prestressing force is divided into two components: one parallel to the base surface 7 and one perpendicular to it. With reference to the first and second planes 85, 87, the component of the prestressing force acting perpendicular to the base surface 7, the first and second prestressing forces 73, 75, can be determined by trigonometry using the angle between the first and second planes 85, 87. The smaller angle in the lowered position results in a smaller force component perpendicular to the base surface 7. This leads to a lower overall force acting perpendicular to the base surface 7.When the angle is determined with reference to the first plane 85, after the dead center point has been overcome, the angle between the first plane 85 and the second plane 87 in the suction position with reference to the first plane 85 can become negative, since the two planes 85 and 87 move in opposite directions and are thus oriented in opposite directions after the dead center point. This allows a reversal of the perpendicular component of the preload force, so that an effective adjustment of the force direction and magnitude can be achieved according to the requirements of the respective position of the suction foot 25.

[0056] As explained, the first stop element 53 is arranged on the frame 3, which is designed to come into contact with the swivel arm 59 in the extraction position and to prevent the fourth swivel axis 63 on the swivel arm 59 from pivoting away from the floor surface 7 to be cleaned (see Figure 6This ensures that the initial preload force with which the suction foot 25 is pressed onto the floor surface 7 to be cleaned remains limited. This is because the first stop element 53 prevents the angle between the aforementioned first plane 85 and the aforementioned second plane 87 from increasing arbitrarily, which would otherwise lead to an increase in the initial preload force.

[0057] In summary, it can be stated that a floor cleaning machine 1 is provided in which the suction foot 25 can be pivoted in a particularly simple and reliable manner, with the suction foot 25 being held in the raised position and in the suction position with a predetermined preload. Reference symbol list:

[0058] 1 Floor cleaning machine 3 Frame 5 Chassis 7 Floor surface 9 Cleaning element arrangement 11 Cleaning element 13 Housing 15 Guide handle arrangement 17 First chassis axle 19 Second chassis axle 21 First roller unit 23 Second roller unit 25 Suction foot 27 Wheel 29 Wheel plane 31 Base 33 Front sealing lip 35 Rear sealing lip 37 Suction chamber 39 Holding arm 41 First swivel axis 43 Preload element 45 First end 47 Second end 49 Longitudinal axis 51 Actuating element 53 First stop element 55 Second stop element 57 Second swivel axis 59, 59' Swivel arm 61 Third swivel axis 63 Fourth swivel axis 65 First support bolt 67 Second support bolt 69 First leg 71 Second leg 73 first preload force 75 second preload force 77 first stop piece 79 second stop piece 81 first arm 83 second arm 85 first level 87 second level

Claims

1. Floor cleaning machine (1) comprising a frame (3), a chassis (5) arranged on the frame (3) for moving the floor cleaning machine (1) over a floor surface (7) to be cleaned, a cleaning element arrangement (9) with at least one, preferably driven, cleaning element (11) designed to engage with the floor surface (7) to be cleaned, and means for applying cleaning fluid to the floor surface (7) to be cleaned, a suction foot (25) designed to be guided over the floor surface (7) to be cleaned and to pick up cleaning fluid from the floor surface (7), wherein the floor cleaning machine (1) is designed to be moved in a forward direction over the floor surface (7) to be cleaned during cleaning operation, wherein the suction foot (25) is arranged in the forward direction at a rear end of the floor cleaning machine (1), and wherein the suction foot (25) is attached to a support arm (39).which is pivotably connected to the frame (3) about a first pivot axis (41), wherein the support arm (39) can be pivoted between a suction position in which the suction foot (25) is in contact with the floor surface (7) to be cleaned, so that it can draw cleaning fluid from the floor surface (7) to be cleaned, and a raised position in which the suction foot (25) is spaced away from the floor surface (7) to be cleaned, wherein a preloading element (43) is arranged between the frame (3) and the support arm (39), which is configured to exert a first preloading force (73) on the support arm (39) in the suction position, which pushes the suction foot (25) towards the floor surface (7) to be cleaned, and to exert a second preloading force (75) on the support arm (39) in the raised position, which pushes the suction foot (25) away from the floor surface (7) to be cleaned, and wherein the first The preload force (73) is less in magnitude than the second preload force (75).

2. Floor cleaning machine (1) according to claim 1, wherein the preload element (43) is designed as a compression spring element extending between a first end (45) and a second end (47) along a longitudinal axis (49), wherein the first end (45) is supported on the retaining arm (39) and the second end (47) is supported on the frame (3).

3. Floor cleaning machine (1) according to claim 2, wherein the first end (45) is pivotably mounted on the support arm (39) about a second pivot axis (57) which runs parallel to the first pivot axis (41), wherein a pivot arm (59, 59') is provided which is pivotably mounted on the frame (3) about a third pivot axis (61) which runs parallel to the first pivot axis (41), and wherein the second end (47) is pivotably mounted on the pivot arm (59, 59') spaced apart from the third pivot axis (61) about a fourth pivot axis (63), wherein the fourth pivot axis (63) runs parallel to the first pivot axis (41).

4. Floor cleaning machine (1) according to claim 2 or 3, wherein in the raised position the fourth pivot axis (63) is arranged perpendicular to the floor surface (7) to be cleaned below a first plane (85) extending through the first and the second pivot axes (41, 57), and wherein in the suction position the fourth pivot axis (63) is arranged perpendicular to the floor surface (7) to be cleaned above the first plane (85) extending through the first and the second pivot axes (41, 57).

5. Floor cleaning machine (1) according to claim 4, wherein an angle between the first plane (85) and a second plane (87) extending through the second pivot axis (57) and the fourth pivot axis (63) is greater in the raised position than in the suction position.

6. Floor cleaning machine (1) according to one of claims 3 to 5, wherein a first stop element (53) is arranged on the frame (3), which is designed to come into contact with the swivel arm (59, 59') in the suction position and to prevent the fourth pivot axis (63) on the swivel arm (59, 59') from pivoting away from the floor surface (7) to be cleaned.

7. Floor cleaning machine (1) according to one of the preceding claims, wherein a second stop element (55) is arranged on the frame (3) which is designed to come into contact with the holding arm (39) in the raised position and to prevent the holding arm (39) from pivoting beyond the raised position away from the floor surface (7) to be cleaned.

8. Floor cleaning machine (1) according to one of the preceding claims, wherein the holding arm (39) is connected to the frame (3) at a first end section and has an actuating element (51) at an end section opposite the first end section.

9. Floor cleaning machine (1) according to one of claims 2 to 8, wherein a first support bolt (65) extending along the second pivot axis (57) is provided on the support arm (39), wherein the pivot arm (59, 59') has a second support bolt (67) extending along the fourth pivot axis (63) and wherein the compression spring element is supported with its first end (45) on the first support bolt (65) and with its second end (47) on the second support bolt (67).

10. Floor cleaning machine (1) according to claim 9, wherein the swivel arm (59, 59') has a first leg (69) and a second leg (71), wherein the second support bolt (67) extends between the first and the second leg (69, 71).

11. Floor cleaning machine (1) according to claim 9 or 10, wherein the compression spring element comprises a compression spring and a first stop piece (77) arranged at the first end (45) of the compression spring element and a second stop piece (79) arranged at the second end (47) of the compression element, wherein the compression spring extends between the first stop piece (77) and the second stop piece (79) and is supported on them, and wherein the first stop piece (77) rests against the first support bolt (65) and the second stop piece (79) rests against the second support bolt (67).

12. Floor cleaning machine (1) according to claim 11, wherein the first stop piece (77) has first arms (81) extending along the longitudinal axis (49) towards the second stop piece (79) and the second stop piece (79) has second arms (83) extending along the longitudinal axis (49) towards the first stop piece (77) and wherein the first and second arms (81, 83) are spaced apart about the longitudinal axis (49) such that a first arm (81) is arranged between two second arms (83).

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