EP4212671B1 - Self-propelled device for cleaning sand - Google Patents

Description

The present invention relates to a self-propelled device for cleaning sand. "Sand" here means granular, mineral materials made of quartz, lime, dolomite or granite in particular, with a typical grain size of about 1 to 6 mm. "Cleaning" includes in particular the loosening, aeration and removal of impurities, whereby the sand is raised above its surface and passes through a sieve that separates the impurities. Typical applications of the invention relate to the cleaning of sand in sandpits and on fall protection areas beneath play and climbing equipment, as well as the sand areas at jumping pits and shot put facilities in schools and sports facilities, and also sand areas on beaches and leisure facilities.

Sand cleaning at playgrounds and sports and leisure facilities is carried out to a large extent by specialised commercial companies that are commissioned by local authorities such as towns and communities. The surface layers of contaminated sand typically contain animal excrement, broken glass, bottle caps, cigarette butts and the like. Aerobic microflora predominates up to a distance of around 15 to 20 cm from the sand surface. This is followed by anaerobic microflora at a depth of around 25 to 40 cm, depending on the type, quality and compaction of the sand. The bacteria and microorganisms cause the typical musty smell that can occur on sand surfaces that have not been maintained for a long time. The sand on the fall protection areas below play and climbing equipment must also be regularly loosened to a depth of at least 40 cm to ensure effective fall protection.

Commercial sand cleaning at play and sports facilities is typically carried out using mobile sand cleaning devices, which have as their essential components a chassis, a drive motor, a sand elevator, a sieve, a container for collecting contaminants and mechanical control and regulation devices. The sand elevator was designed in accordance with the state of the art ( EP 1 108 816 A2 ) is provided with a plurality of sand conveying elements (slats, shovels, buckets) which are attached to a motor-driven, endless conveyor device (parallel and spaced-apart chains or belts or a single, wide, rotating belt made of rubber material) which rotates between a digging position immersed in the sand to be cleaned and a preferably overhead discharge position from which the sand lifted with the aid of the sand conveying elements is thrown onto a sieve which allows the sand to pass through and which separates off impurities which end up in the receiving container. The sieve can be an inclined vibrating sieve and the sand which has passed through the sieve automatically falls back onto the sand surface behind the receiving point. The frame (chassis) running on wheels, crawlers and/or chains is typically equipped with at least one motor-driven shaft in order to create a mobile, self-propelled sand cleaning device. The engine on the chassis, typically an internal combustion engine, is expediently coupled to a hydraulic pump, which supplies the various consumers (drive, conveyor device of the sand elevator) with hydraulic fluid via hydraulic lines. Furthermore, a cover and housing is typically provided at least for the sand elevator.

"Digging section" refers - depending on the adjustment/lowering of the sand elevator - to the section of the conveyor system with conveyor elements that is immersed in the sand to be cleaned so that the moving conveyor elements dig into the sand and pick up sand.

"Digging position" refers to a position of the conveyor in which the digging piece is immersed in the sand to be cleaned.

"Digging depth" refers to the distance between the middle sand surface and the lower edge of the lowest conveyor element within the sand to be cleaned when the digging piece is in its digging position. The solid, heavy frame of the sand cleaning device can serve as a reference point for the sand surface when it is standing or moving on the sand surface.

The sand elevator is used to pick up the sand using a digging piece that can be adjusted between a selectable working position (digging position) that is immersed to different depths in the sand to be cleaned and a rest position above the sand surface. The digging piece assumes this rest position, for example, when the mobile sand cleaning device automatically moves from its transport vehicle to the site of use, or when the sand cleaning device is reset during the sand cleaning process. Starting from this rest position, the digging piece must be lowered until it is immersed sufficiently deeply in the sand to be cleaned so that the sand elevator can pick up and circulate sand. This type of digging piece lowering is achieved by adjusting the sand elevator in relation to a frame (chassis) of the sand cleaning device that holds the sand elevator. To carry out this type of adjustment, the entire sand elevator can, for example, be pivotably attached to the chassis. The pivoting is carried out by a hydraulically operated piston/cylinder arrangement, the piston rod of which adjusts the sand elevator so that its excavation piece is immersed more or less deeply into the sand. According to an alternative embodiment, the entire sand elevator can be moved along two rails that are parallel and spaced apart from each other and almost vertically aligned and fixed to the chassis (downwards) onto the sand surface or away from the sand surface (upwards). upwards). The downward adjustment (lowering) is typically carried out solely under the influence of gravity. The upward adjustment (raising) is provided by at least one hydraulically operated piston/cylinder arrangement, which is inserted between a support on the chassis and an abutment on the sand elevator.

Known mobile sand cleaning devices of this type are in use and are described, for example, in the documents DE-C2-32 09 134 , DE-C2-34 37 926 , DE-A1-35 13 454 , DE-A1-40 07 409 or in the German patent application 198 53 351.9 described. In all of these known sand cleaning devices, the digging depth is determined solely and exclusively by appropriate adjustment and locking of levers, rods or lifting cylinders, which fix the sand elevator in a certain position with respect to the chassis, so that the digging piece is immersed in the sand to be cleaned up to a certain digging depth according to this sand elevator position.

The document EP 0 319 420 B1 discloses a self-propelled machine for cleaning beaches. The known self-propelled device has a tipping container into which the collected waste is conveyed. Furthermore, at the front of the device in the direction of travel there is a pivoting conveyor which ends at its inlet in a scraper plate which slides over the beach to be cleaned in order to collect waste which is then conveyed into the tipping container by means of the two-stage conveyor.

The document DE 36 27 015 A1 discloses an earth-clearing device, for example in the form of a bucket wheel excavator, with a chassis on which an elevator is located, the inclination of which can be changed relative to the chassis. To change the inclination of the elevator, an actuating cylinder is used, to which a sensor is assigned, which detects the respective inclination of the elevator and in converts electrical signals that are fed to a signal processing device.

Based on this, the technical field of the present invention is to specify or provide a device for sand cleaning, in particular for commercial purposes.

The closest state of the art in this regard is derived from the DE 199 60 209 C1 and the EP 1 108 816 A2 This prior art already shows a method for cleaning sand, in particular for cleaning sand in sandpits, playgrounds and sports facilities, with the aid of a mobile sand cleaning device which has a frame which can be moved on the sand surface and on which a sand elevator is held in an adjustable manner, in particular so as to be lowered and raised, which is equipped with a rotating conveyor device designed as an endless belt which is provided with a large number of conveyor elements which rotate between a digging position immersed in the sand to be cleaned and a discharge position from which the sand transported in the conveyor elements is thrown onto a sieve located on the sand cleaning device which allows the sand to pass through and which separates impurities which end up in a collecting container, the frame standing or moving on the original surface of the layer of sand to be cleaned; the adjustment/lowering of the sand elevator in relation to the frame causes the lower edge of the lowest conveyor element to sink more or less deeply into the sand layer below the sand surface on which the frame stands or moves.

This prior art further describes a mobile sand cleaning device, with a frame that can be moved on the original surface of the sand layer to be cleaned, on which a sand elevator is adjustable, in particular lowerable and raiseable, which is connected to a motor-driven, circulating belt designed as an endless belt. Conveying device provided with a plurality of conveyor elements which rotate between a digging position immersed in the sand to be cleaned and a discharge position from which the sand transported in the conveyor elements is thrown onto a sieve located on the sand cleaning device, which allows the sand to pass through and separates impurities which end up in a collecting container, the respective digging depth depending on the extent of the respective adjustment/lowering of the sand elevator with respect to the frame.

Further related state of the art results from the DE 10 2019 2017 807 A1 The sand cleaning device described there is also self-propelled, which means that it has a drive to move it forward. It is guided by an operator who has to walk behind the machine and controls the machine using two longitudinally extending beams to the rear.

Corresponding sand cleaning devices according to this state of the art have proven themselves. These sand cleaning devices of the state of the art are usually guided by an operator on two longitudinally protruding rearward handles like similar small agricultural devices such as scarifiers, motor plows or snow blowers. The operator thus determines both the direction of travel and the immersion depth (digging depth) of the sand cleaning device. This has the disadvantage that the operator must constantly walk behind the machine and is exposed to the noise and exhaust fumes of the drive motor, which is usually designed as an internal combustion engine. In addition, the operator must bend down when working under trees or playground equipment. Furthermore, the operator is exposed to strong vibrations via the handles and has to endure the noise of the internal combustion engine. Finally, it often happens that the drive force of the machine, the is only transferred to the ground via the two drive wheels, is not sufficient, for example because the machine is working in particularly loose and deep sand in which the wheels spin. The operators then try to push the machine with their hips on the handlebars, which often causes hip injuries.

Based on this prior art, it is therefore the object of the present invention to further develop such a sand cleaning device in such a way that the physical effort for the operator and the strain on the operator are reduced and the operating comfort is significantly increased.

According to the invention, this object is achieved with a device according to claim 1 or 11.

Advantageous embodiments and further developments of the invention emerge from the subclaims.

According to the invention, the above-mentioned object is achieved with a sand cleaning device which comprises a chassis with chains and a sand elevator which is adjustable, in particular lowerable and raiseable, on the chassis and is equipped with a motor-driven, rotating conveyor device, which is provided with a plurality of conveyor elements which rotate between a digging position immersed in the sand to be cleaned and a discharge position from which the sand transported in the conveyor elements is thrown onto a sieve which allows the sand to pass through and which separates impurities which end up in a collecting container, the chains and the conveyor device being driven by an electric motor each, while the sand elevator is moved by means of hydraulic cylinders whose pressure is supplied by an electrically driven pump, and accumulators serving to supply the electric motors are also on the chassis As a result, the operator is not exposed to the noise and exhaust fumes of an internal combustion engine, and the sand cleaning device according to the invention can also be used in noise-sensitive areas.

According to the invention, the accumulators are mounted in the rear third of the chassis, as seen in the direction of travel. This prevents the sand cleaning device according to the invention from getting stuck in the loose, cleaned sand, since the center of gravity located far back compensates for the forces resulting from the digging action of the sand elevator.

Furthermore, it is particularly preferred if the batteries are provided with at least one handle and are inserted into the chassis so that they can be replaced in just a few steps. In this way, empty batteries can be quickly replaced with full ones without the machine being out of action while the batteries are charging.

It is particularly preferred if the batteries can be attached and removed from the chassis using snap fasteners. This prevents moderators from coming loose from the chassis when driving uphill, but still allows the batteries to be replaced quickly.

It is further preferred if the tracks of the chassis are each guided over 3 wheels with parallel axes in one plane, with 2 wheels arranged in such a way that they press the tracks onto the ground, while the 3rd wheel is arranged offset to the front above the rear wheel and is driven by the electric motor. In this way, sufficient ground clearance of the sand cleaning device can be ensured, even if the electric drive motors are significantly larger than the hydraulic motors that have been used up to now.

Preferably, the front wheel has a larger diameter than the other two wheels. This also prevents the machine from getting stuck in loose sand

According to the invention, the sand elevator can be moved sideways relative to the chassis by means of hydraulic cylinders.

The above-mentioned object is also achieved with a mobile sand cleaning device with a chassis on which a sand elevator is adjustable, in particular lowerable and raiseable, which is equipped with an endless, motor-driven, rotating conveyor device, which is provided with a plurality of conveyor elements that rotate between a digging position immersed in the sand to be cleaned and a discharge position, from which the sand transported in the conveyor elements is thrown onto a sieve located on the sand cleaning device, which allows the sand to pass through and separates impurities, which end up in a collecting container, wherein the sand cleaning device is additionally provided with a remote control for the functions of direction of travel, travel speed, lowering and raising as well as tilting the sand elevator. This also makes the work considerably easier for the operator. They no longer have to run behind the machine the entire time, and the machine, which can be built relatively flat, can then also be used under trees or playground equipment without the operator having to squeeze under these obstacles.

It is particularly preferred that the remote control also includes the functions of operation and speed of the sand elevator and/or operation and speed of beaters for the sieve and/or the collecting container.

Furthermore, it is particularly preferred that the remote control also includes the functions of drift correction and/or horizontal adjustment of the sand elevator relative to the chassis.

It is particularly preferred if the remote control works by means of electromagnetic waves, preferably radio waves or infrared.

Furthermore, it is particularly preferred that the remote control comprises a display on which the current operating states of the sand elevator are shown

• Fig. 1 eine 3-dimensionale Darstellung einer erfindungsgemäßen Sandreinigungsvorrichtung von seitlich hinten;
• Fig. 2 eine 3-dimensionale Darstellung der Sandreinigungsvorrichtung der Fig. 1 von der anderen Seite;
• Fig. 3 die erfindungsgemäße Sandreinigungsvorrichtung der Fig. 1 von der Seite;
• Fig. 4 die Sandreinigungsvorrichtung der Fig. 1 von vorne;
• Fig. 5 die Sandreinigungsvorrichtung der Fig. 1 von hinten;
• Fig. 6 eine 3-dimensionale Darstellung der Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators schräg von vorne-oben;
• Fig. 7 eine 3-dimensionale Darstellung der Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators schräg von hinten-oben;
• Fig. 8 die Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators von der Seite;
• Fig. 9 die Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators von vorn;
• Fig. 10 die Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators von hinten;
• Fig. 11. die Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators und aller Verkleidungen von oben;
• Fig. 12 die Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators und aller Verkleidungen von der Seite;
• Fig. 13 die Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators und aller Verkleidungen von der anderen Seite;
• Fig. 14 die Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators und aller Verkleidungen von vorn;
• Fig. 15 die Sandreinigungsvorrichtung der Fig. 1 nach Demontage des Sandelevators und aller Verkleidungen von hinten;
• Fig. 16 einen Akkumulator für die erfindungsgemäße Sandreinigungsvorrichtung von oben;
• Fig. 17 eine Fernsteuerung für die Sandreinigungsvorrichtung der Fig. 1 von oben;
• Fig. 18 eine 3-dimensionale Darstellung der Fernsteuerung der Fig. 17;
• Fig. 19 die Fernsteuerung der Fig. 17 von der Schmalseite; und
• Fig. 20 die Fernsteuerung der Fig. 17 von der Längsseite;

In the following, the present invention is explained in more detail using an exemplary embodiment with reference to the accompanying drawings. It shows:

• Fig. 1 a 3-dimensional representation of a sand cleaning device according to the invention from the rear side;
• Fig. 2 a 3-dimensional representation of the sand cleaning device of the Fig. 1 from the other side;
• Fig. 3 the sand cleaning device according to the invention of Fig. 1 from the side;
• Fig. 4 the sand cleaning device of the Fig. 1 from the front;
• Fig. 5 the sand cleaning device of the Fig. 1 from behind;
• Fig. 6 a 3-dimensional representation of the sand cleaning device of the Fig. 1 after dismantling the sand elevator diagonally from the front-top;
• Fig. 7 a 3-dimensional representation of the sand cleaning device of the Fig. 1 after dismantling the sand elevator diagonally from behind and above;
• Fig. 8 the sand cleaning device of the Fig. 1 after dismantling the sand elevator from the side;
• Fig. 9 the sand cleaning device of the Fig. 1 after dismantling the sand elevator from the front;
• Fig. 10 the sand cleaning device of the Fig. 1 after dismantling the sand elevator from behind;
• Fig. 11 . the sand cleaning device of the Fig. 1 after dismantling the sand elevator and all panels from above;
• Fig. 12 the sand cleaning device of the Fig. 1 after dismantling the sand elevator and all panels from the side;
• Fig. 13 the sand cleaning device of the Fig. 1 after dismantling the sand elevator and all panels from the other side;
• Fig. 14 the sand cleaning device of the Fig. 1 after dismantling the sand elevator and all panels from the front;
• Fig. 15 the sand cleaning device of the Fig. 1 after dismantling the sand elevator and all panels from the rear;
• Fig. 16 an accumulator for the sand cleaning device according to the invention from above;
• Fig. 17 a remote control for the sand cleaning device of the Fig. 1 from above;
• Fig. 18 a 3-dimensional representation of the remote control of the Fig. 17 ;
• Fig. 19 the remote control of the Fig. 17 from the narrow side; and
• Fig. 20 the remote control of the Fig. 17 from the long side;

As in Fig. 1 to 5 As shown, a sand cleaning device 1 according to the invention comprises a chassis 10 which is provided with crawler tracks 12. The tracks 12 are arranged on the outside of the sides of the chassis 10 and extend over the entire length of the chassis 10. According to the invention, the tracks 12 are deflected via three wheels 14, 16 and 18 which lie in one plane with parallel axes. The wheels 14, 16 deflect the track 12 to the front and rear and simultaneously press the track 12 onto the ground. The wheel 18 is arranged slightly offset to the front above the rear wheel 16 and is driven by an electric motor. It serves to drive the track 12. The front wheel 14 has a significantly larger diameter than the other two wheels 16, 18. This is intended to prevent the machine from getting stuck in the sand that it loosens up during cleaning. Furthermore, the tracked chassis of the chassis 10 is designed in the usual way, for example it has running support wheels 20 which distribute the weight of the chassis 10 evenly over the length of the chain 12 resting on the ground. As in Figure 2 As can be seen, the arrangement of the crawler track on the other side of the chassis 10 is mirrored.

At its front end, the chassis 10 carries the sand elevator 36, which can be moved up and down relative to the chassis 10 by means of hydraulic cylinders and its inclination can be adjusted relative to the vertical. This additional adjustment of the inclination angle of the sand elevator 36 allows better adaptation to different hard surfaces to be processed and also enables greater ground clearance during transport and, if necessary, when loading the sand cleaning device 1 onto a transport vehicle. In addition, it can be provided that the sand elevator 36 can also be moved by means of further Hydraulic cylinder can be moved laterally relative to the chassis 10.

Next is in Fig. 1 It can be seen that the sand elevator 36 comprises a conveyor device 37 enclosed by a housing 38. This conveyor capacity 7 and 30 is designed as a wide belt, which is deflected at the top and bottom over two rollers 39 arranged horizontally and with axes parallel to one another. One of the rollers 39, preferably the upper one, is driven by an electric motor. The belt 37 extends over the entire working width of the sand elevator 36. Conveyor elements 76 are arranged on the belt 37 at equal distances and projecting radially outwards.

These conveyor elements 76 comprise an L-profile with two legs at an angle of approximately 90° to one another, the shorter leg of which is arranged parallel to the surface of the belt 36, while the other, longer leg projects radially outwards and is bent in its outer region against the intended direction of rotation of the conveyor device 37. The conveyor elements 76 are closed off on the outside by a pentagonal sheet 78 so that sand captured by the conveyor elements 76 can no longer flow off to the side.

The Sandelevator 36 works as follows:
By rotating one of the rollers 39, the conveyor device 37 rotates clockwise, ie in such a way that the conveyor elements 76 are moved forwards at the bottom. The conveyor elements 76 are thus filled with the sand into which the conveyor device 37 is immersed. This is conveyed upwards on the distal side of the housing 38, and the sheets 78 prevent it from escaping laterally from the conveyor elements 76.

In the housing 38 at the top, the sand is then ejected backwards through the opening of the housing 38 by centrifugal force and gravity and hits a collecting sieve 48. This can have an appropriate mesh diameter so that only sand components of a corresponding fineness pass through the collecting sieve 48 and are deposited again on the bottom.

All larger foreign bodies in the excavated sand get caught on the collecting sieve 48 and slide down along it due to the effect of gravity into the collecting container 50, where they accumulate. The collecting container 50 must then be emptied occasionally by the operator. The collecting sieve 48 and the collecting container 50 preferably consist of metal grids with a corresponding mesh size. The collecting sieve 48 and/or the collecting container 50 can each be provided with a knocking device 51 so that the sand falls through better. These are preferably also driven by an electric motor, but a hydraulic drive is also conceivable.

At the other, rear end of the chassis 10, there is a control panel 60 at the top with the controls required to control the sand cleaning device 1, for example when a remote control cannot be used. The control panel 60 also includes a plug for connecting a charging cable for charging the accumulators 80 when installed. In front of this control panel there is a box 62 which contains all the control electronics. An emergency stop switch 64 and, if necessary, an antenna for the remote control and, if necessary, for a satellite navigation system can be arranged on this.

Under the control panel 60, three accumulators 80 are arranged one above the other at the rear end of the chassis 10. To the left of the control panel 60, a filler neck 66 for hydraulic oil is provided. Although Since an electric drive is provided according to the invention, it has proven advantageous not to use electric motors with worm gears for adjustment functions such as raising and lowering or tilting the sand elevator 36, but rather hydraulic cylinders, since these are much less sensitive to contamination by the sand. Therefore, a tank for hydraulic oil and an electrically driven hydraulic oil pump are also provided under the cover 68.

How particularly good in Figure 5 As can be seen, the accumulators 80 are cuboid-shaped (70 cm long, 30 cm wide, 20 cm high). For better handling, the accumulators 80 are provided with a handle 82 arranged centrally on their rear-facing surface. This handle 82 can, as shown, be folded flat so that it does not get in the way. This arrangement of the accumulators 80 ensures that the center of gravity of the sand cleaning machine 1 according to the invention is shifted as far back as possible. This successfully prevents the machine according to the invention from getting stuck in the sand that it loosens up during cleaning.

The Fig. 6-10 show the chassis 10 of the sand cleaning device 1 alone, ie after dismantling the sand elevator 36. This shows a carrier plate 22, which normally carries the sand elevator 36, and which can be moved up and down along rails 26 by means of a hydraulic cylinder 24. The rails 26 can also be moved together at the top forwards and backwards by means of a hydraulic cylinder (not shown), whereby the inclination of the sand elevator 36 can be adjusted. In Figure 6 you can also see the main electrical control cabinet 28, i.e. the main electrical distribution

Figure 10 still shows fender systems 30 right and left above the chains 12.

The Fig. 11-15 show the chassis 10 of the sand cleaning device 1 after removing all panels. Here you can see in Figure 11 very good the hydraulic pump 90 with the tank 92 arranged above it for the hydraulic oil and the electric drive motor 94, which is arranged in front of the pump 90 in such a way that the common axis of rotation extends along the direction of travel of the chassis 10. As shown, this assembly is arranged on the left side of the chassis 10 in the rear half. 96 designates hydraulic valves on the left side of the chassis 10 for actuating the knocking device 51. 98 designates a valve assembly on the right side of the chassis 10 for adjusting the sand elevator 36.

A charger 84 for the accumulators 80 is arranged opposite the tank 92 on the other side of the chassis 10. This allows the sand cleaning device 1 according to the invention to be charged using normal mains plugs. The sand cleaning device 1 is therefore independent of a special charging infrastructure.

The chassis 10 according to the invention also has a 12 volt network in order to be able to supply and use normal electrical consumers for motor vehicles.

On Figure 15 the hydraulic oil filter 91 arranged below the hydraulic oil tank 92 can be seen.

Figure 16 shows one of the accumulators 80 from the side. On its right side, the handle 82 for easier handling of the accumulators 80 can be seen and on its left side, a protective cover 88 for the plug device for electrically connecting the accumulator 80.

The sand cleaning device 1 according to the invention can also be operated for the first time by means of a remote control 100. Figures 17-20 show the remote control 100 for the sand cleaning device 1. The control commands of the remote control 100 are preferably transmitted via radio or infrared.

The remote control 100 comprises a substantially elongated, cuboid-shaped housing 110, which can be worn by the operator using a belt (not shown) so that it hangs in front of the operator's stomach at elbow height, where it can be operated in an ergonomically optimal manner. On the upper surface of the housing 110, i.e. the surface facing upwards in this position, all of the control elements required for remote control of the sand cleaning device 1 and a display 120 are arranged as follows:
The display 120 is arranged centrally and offset towards the side of the surface of the housing 110 facing away from the operator, as in Figure 17 clearly visible. A joystick 130 and 140 is attached to both sides of the display 120. The right joystick 140 is used to control the direction of travel and the speed of the sand cleaning device 1. The further the joystick 140 is pushed forward, the faster the sand cleaning device 1 moves forwards; if the joystick 140 is moved backwards, the sand cleaning device 1 moves backwards accordingly. The sand cleaning device 1 can be steered accordingly by moving the joystick 140 to the right and left. By moving the joystick 140 at an angle, the sand cleaning device according to the invention can make a curve. The movement commands from the joystick 140 are converted into control signals for the drive motors of the chains 12 via electronics in the main control cabinet 28.

The left joystick 130 is used to control the sand elevator 36. A forward movement of the joystick 130 leads to a lowering of the sand elevator 36, and a backward movement of the joystick 130 leads to a lifting of the sand elevator 36. The right and Leftward movement of the joystick 130 leads to a flatter or steeper incline of the sand elevator 36.

Between the left joystick 130 and the display 120, a button 150 that can be moved to the right and left is provided, with which the optional right and left movement of the sand elevator 36 relative to the chassis 10 can be controlled.

Between the display 120 and the right joystick 140 there is a rotary knob 160 for setting the drift compensation, i.e. for a stronger chain drive of the downhill chain if the sand cleaning device 1 is travelling at an angle or across a slope. By means of this setting it can be achieved that the sand cleaning device 1 follows a straight line even if it is working at an angle or across a slope by driving the downhill chain more strongly depending on the slope incline.

Diagonally below the display 120, i.e. on the side of the housing 110 facing the operator, an emergency stop switch 170 is provided, with which an immediate complete shutdown of the sand cleaning device 1 can be brought about.

Below the joystick 140, on the right, there is a switch 172 for switching between fast and slow travel (transport and work or off-road travel).

Between this switch 172 and the emergency stop switch 170 there is a controller 174 for adjusting the driving speed.

To the left of the emergency stop switch 170 there is an on/off switch 176 and a speed controller 178 for the knocking device 51.

To the left of the speed controller 178 there is an on/off switch 180 and a speed controller 182 for the conveyor device 37.

All operating parameters of the sand cleaning device 1 that are important for the operator can be shown on the display 120, for example driving speed, charge level of the accumulators 80, rpm, digging depth and angle of inclination of the sand elevator 36 and rpm (or speed) of the knocking device 51.

The design of the remote control 100 is most clearly evident from the Figures 18 and 19 As can be seen there, the housing 110 of the remote control 100 has two side walls 190 which are widened at the bottom end towards the back and the front. The widenings each enclose an opening. At their two upper corners, the side walls 190 run into two arms each which protrude diagonally towards the front and the back, each of which has a round rod 192 at its end, with which it is connected to the other side wall. The rods 192 make it easier to handle the remote control 100 and at the same time prevent the operating elements of the remote control 100 from being inadvertently activated by accidental contact. In the course of the arms between the edges of the housing and the rods, the arms each have oval openings 193 which can be used, for example, to guide the carrying strap for the operator through. The two arms of a side wall are connected at half their height to a bridge-like stabilizing element which is slightly curved downwards. Likewise, the arm projecting away from the operator is connected to the lower widening of the respective side wall 190 by a stabilizing element running straight downwards.

list of reference symbols

1

sand cleaning device

10

chassis

12

caterpillar tracks

14

front wheel

16

rear wheel

18

upper wheel

20

support wheels

22

carrier plate

24

hydraulic cylinders (lifting/lowering)

25

hydraulic cylinder (tilting)

26

rails

28

main control cabinet

30

fender systems

36

sand elevator

37

conveyor system

38

Housing

48

collecting sieve

50

collection container

51

knocking device

60

control panel

62

Crate

64

antenna

66

filler neck

68

disguise

76

conveyor elements

78

sheet metal

80

accumulators

81

snap devices

82

handle

84

charger

88

protective cover

90

hydraulic pump

91

hydraulic oil filter

92

hydraulic oil tank

100

remote control

110

Housing

120

display

130

joystick left

140

joystick right

150

button

160

rotary knob

170

emergency stop switch

172

gear selector

174

speed controller

176

on/off switch

178

controller for vibrators

180

switch for sand elevator

182

controller for sand elevator

190

side wall

192

rod

193

opening

Claims (11)

1. Self-propelled sand cleaning device (1),

   which comprises a chassis (10) comprising tracks (12) and a sand elevator (36), which is retained on the chassis (10) so as to be adjustable, in particular such that it can be lowered and raised, and is equipped with a motor-drivable, revolving conveying apparatus (37),

   which is provided with a plurality of conveying elements (76), which revolve between a dug-in position, in which they are immersed in the sand to be cleaned, and a discharge position, from which the sand transported in the conveying elements (76) is dropped onto a screen (48), which lets the sand pass through and separates out any contaminants, which go into a collection container (50),

   characterised in that

   the tracks (12) and the conveying apparatus (37) are each driven by an electric motor, while the sand elevator (36) is moved by means of hydraulic cylinders (24, 25), the oil pressure of which is provided by an electrically driven pump (90), and batteries (80) that power the electric motors are likewise arranged on the chassis (10); and

   the batteries (80) are arranged in the rear third of the chassis (10) when viewed in the travel direction.
2. Self-propelled sand cleaning device (1) according to claim 1, characterised in that the batteries (80) are provided with at least one handle (82) and are inserted into the chassis (10) such that they can be replaced in just a few steps.
3. Self-propelled sand cleaning device (1) according to claim 2, characterised in that the batteries (80) can be locked into and released from the chassis (10) by means of snap-in devices (81).
4. Self-propelled sand cleaning device (1) according to any of claims 1 to 3, characterised in that the tracks (12) of the chassis (10) are each guided by three wheels (14, 16, 18) that are in one plane and have parallel axles, two wheels (14, 16) being arranged such that they press the track (12) onto the ground, while the third wheel (18) is arranged to be offset in the forward direction above the rear wheel (16) and is driven by the electric motor.
5. Self-propelled sand cleaning device (1) according to claim 4, characterised in that the front wheel (14) has a greater diameter than the two other wheels (16, 18).
6. Self-propelled sand cleaning device (1) according to any of claims 1 to 5, characterised in that the sand elevator (36) is also designed to be laterally movable relative to the chassis (10).
7. Self-propelled sand cleaning device (1) according to any of claims 1 to 6, characterised in that the sand cleaning device (1) is provided with a remote control (100) for the functions of travel direction, travel speed, lowering and raising as well as inclining the sand elevator (36).
8. Self-propelled sand cleaning device (1) according to claim 7, characterised in that the remote control (100) also includes the functions of operation and speed of the sand elevator (36) and/or operation and speed of knocking apparatuses (51) for the screen (48) and/or the collection container (50).
9. Self-propelled sand cleaning device (1) according to claim 7 and 8, characterised in that the remote control (100) also includes the functions of drift correction and/or horizontal adjustment of the sand elevator (36).
10. Self-propelled sand cleaning device (1) according to any of claims 7 to 9, characterised in that the remote control (100) operates by means of electromagnetic waves, preferably radio waves or infrared.
11. Self-propelled sand cleaning device (1) according to any of claims 7 to 10, characterised in that the remote control (100) comprises a display (120), on which the current operating states of the sand cleaning device (1) are displayed.

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