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Title:
LEVELLING DEVICE WITH SCRAPER BLADE
Document Type and Number:
WIPO Patent Application WO/2021/235935
Kind Code:
A1
Abstract:
Levelling device with a scraper blade (3) and a sliding shoe (5). The scraper blade is connected on the left-hand side and on the right-hand side to a hydraulic cylinder (9), which is connected to a control system arranged to ensure that the scraper blade remains fixed in the same horizontal or tilted orientation to the left or to the right with respect to the sliding shoe when performing an upward/downward movement, and also to ensure that the centre of the scraper blade remains fixed at the same height with respect to sliding shoe when tilting the scraper blade anticlockwise or clockwise.

Inventors:
RIJNEN, Martinus Wilhelmus Maria (NL)
Application Number:
PCT/NL2021/050321
Publication Date:
November 25, 2021
Filing Date:
May 20, 2021
Export Citation:
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Assignee:
RIJNEN GRONDVERZET B.V. (NL)
International Classes:
E02F3/76; E02F3/84
Attorney, Agent or Firm:
ALGEMEEN OCTROOI- EN MERKENBUREAU B.V. (NL)
Download PDF:
Claims:
CLAIMS

1. Device (1) for levelling and/or bringing a sand bed or other subsurface to the correct height (2), which device comprises a scraper blade (3), arranged for scraping or rough levelling and/or heightening a top layer of the subsurface, and furthermore comprises a sliding shoe (5), arranged to be dragged over the subsurface, wherein the scraper blade is connected on both its left (L) side and its right (R) side to a hydraulic cylinder (9L, 9R), which cylinders are connected with, and/or engage with, the left and the right side of the sliding shoe, respectively, while the scraper blade is bearing-mounted in such a way that the cylinders can independently move the scraper blade up and down or tilt the scraper blade to the left and to the right, with respect to the sliding shoe, wherein the cylinders are connected to a hydraulic control system arranged to ensure that during an upward or downward movement the scraper blade remains fixed in the same horizontal orientation, or tilted orientation to the left or to the right, with respect to the sliding shoe, and/or to ensure that during a left/right movement of the scraper blade the centre of the scraper blade remains fixed at the same height with respect to the sliding shoe.

2. Device according to claim 1, wherein both cylinders are controlled from two hydraulic valves, each having two inlet ports (A/B) and two outlet ports (X/Y) which valves, by actuating the valves, are able to separate the inlet ports and outlet ports, and are able to interconnect the inlet ports and outlet ports either directly (A-X/B-Y) or crosswise (A-Y/B-X), wherein the first and second outlet ports (X and Y, respectively) of the first valve (10L) are connected to the first and second hydraulic connections (U and V, respectively) of the first cylinder (9L), wherein the first outlet port (X) of the first valve is connected to the first hydraulic connections (U) of both cylinders (9) by means of two outlet ports of a first flow divider, and wherein the second outlet port (Y) of the first valve is connected to the second hydraulic connections (V) of both cylinders (9) by means of two outlet ports of a second flow divider, whereby the first and second outlet ports (X and Y, respectively) of the second valve (10R) are connected to the first and second hydraulic connections (U and V, respectively) of the second cylinder (9R), wherein the first outlet port (X) of the second valve is connected to the second hydraulic connection (V) of the first cylinder (9L) and to the first hydraulic connection (U) of the second cylinder (9R) by means of two outlet ports of a third flow divider, and wherein the second outlet port (Y) of the second valve is connected to the first hydraulic connection (U) of the first cylinder (9L) and to the second hydraulic connection (V) of the second cylinder (9R) by means of two outlet ports of a fourth flow divider.

Description:
Title: Levelling device with scraper blade

DESCRIPTION

The invention relates to a device for levelling and/or bringing a sand bed or other subsurface to the correct height, which device comprises a scraper blade, arranged for scraping or rough levelling and/or heightening a top layer of the subsurface in a direction of motion, and furthermore comprises a sliding shoe (or drag shoe), arranged to be dragged over the subsurface and thereby compacting and/or more accurately levelling the subsurface. Such equipment is commonly known as a levelling device or leveller.

It is an object of the present invention to provide such a levelling device wherein, in particular when used in combination with a tachymeter or total station control system, the functions of raising/lowering and tilting of the scraper blade are automatically performed in such a way that the transverse (straight or tilted) orientation of the scraper blade remains fixed with respect to the transverse orientation of the sliding shoe during raising or lowering of the scraper blade, and in such a way that the height of (the centre of) the scraper blade with respect to the height of the sliding shoe remains fixed during the variation of the transverse orientation (the tilting angle/tilting) of the scraper blade.

For this purpose, according to the invention, a device of the type indicated above is provided, wherein the scraper blade is connected on both its left side and its right side to a hydraulic cylinder, which cylinders are connected with, and/or engage with, the left and the right side of the sliding shoe, respectively, while the scraper blade is bearing- mounted in such a way that the cylinders can independently move the scraper blade up and down or tilt the scraper blade to the left and to the right. The cylinders are connected to a hydraulic control system arranged to ensure that during an upward or downward movement the scraper blade remains fixed in the same horizontal orientation or tilted orientation (transversely) to the left or to the right with respect to the sliding shoe, and to ensure that during a left/right (anticlockwise/clockwise) movement of the scraper blade, the centre of the scraper blade remains fixed at the same height with respect to the sliding shoe.

The invention will now be discussed in more detail with reference to the figure description below. Figure 1 schematically shows an embodiment of a levelling device according to the invention in front view and side view;

Figure 2a-d schematically show a preferred embodiment of the hydraulic control system of the scraper blade with respect to the sliding shoe of the levelling device shown in Figure 1.

Figure 1 schematically shows an exemplary embodiment of a levelling device 1 according to the invention, intended and arranged for coupling the coupling frame 7 with a propulsion vehicle (not shown) for the purpose of levelling and/or bringing a sand bed or other subsurface (subsoil) 2 to the correct height. The device 1 comprises a scraper blade 3, arranged for scraping or rough levelling and/or heightening a top layer of the subsurface 2 in a direction of motion 4, and comprises a sliding shoe 5, arranged to be dragged behind the scraping blade 3 over the subsurface 2 in the direction of motion 4 during use of the device 1, thereby compacting and/or levelling the subsurface 2 more accurately.

The scraper blade 3 and the sliding shoe 5 are connected to the chassis 8 of the levelling device 1, and are passively rotatable in transverse direction by means of a turntable 6.

The scraper blade 3 is connected on both its left-hand side L and right-hand side R to a hydraulic cylinder 9L and 9R, respectively. Furthermore, the hydraulic cylinders are connected to (and/or are supported on or engage with) the sliding shoe 5, which is dragged (pulled) over the subsurface (subsoil or ground) 2 during use. The scraper blade 3 is bearing-mounted in such a way that the scraper blade 3 can be moved independently by the cylinders 9 upward and downward (up/down) or to the left and to the right (anticlockwise/clockwise tilting) with respect to the gliding shoe (and therefore with respect to the subsurface 2 over which the sliding shoe 5 is dragged/towed).

In order to be able to control the position of the scraper blade 3 with a device control system during use, both in the height position and in the transverse orientation (tilting), with respect to the gliding shoe 5, the cylinders 9 are connected to a hydraulic control system (see figure 2) that is arranged to ensure that the scraper blade 3, during movement up or down, remains fixed in the same horizontal orientation or tilted orientation to the left or right (tilting orientation/transverse orientation) with respect to (the orientation of) the gliding shoe 5. The hydraulic control system is also able to ensure, when performing a left/right movement (tilting) of the scraper blade, that the centre of the scraper blade 3 remains fixed at the same height with respect to the height of the gliding shoe 5.

In other words, the hydraulic control system shown in Figure 2 is arranged to independently perform the up/down movement of the scraper blade and the left/right movement of the scraper blade. This simplifies the control of the system and increases its accuracy. Furthermore, the same hydraulic control system can be used for control from a (2D) laser control system, for which is referred to Figure 2b, as well as for control from a (3D) "total station" or tachymeter (see for example https://en.wikipedia.org/wiki/Total_station) control system, for which is referred to Figures 2c and 2d.

Figure 2a shows schematically an exemplary embodiment of the control of a levelling device 1 according to the invention, as shown in Figure 1, wherein both cylinders 9 (9L/9R) are controlled from two hydraulic valves 10, controllable from the device control system. Each hydraulic valve is provided with two inlet ports A/B and two outlet ports X/Y, which valves, by actuating the valves, e.g. valve slides, by means of the device control system, are able to separate both inlet ports and outlet ports from each other (centre position), and are able to interconnect the inlet ports and outlet ports either directly A-X/B-Y (slide to the left) or crosswise A-Y/B-X (slide to the right).

The outlet ports X/Y of the valves 10L or 10R are connected directly to the hydraulic connections U and V of the cylinders 9L or 9R, respectively.

The outlet port X of the left-hand valve 10L is connected to the connections U of both cylinders 9 via a flow divider ("fd" or "flow divider valve", see e.g. https://tinyurl.com/ybfmuzu2). The outlet port Y of the left-hand valve 10L is connected to the connections V of both cylinders 9 via a flow divider.

The outlet port X of the right-hand valve 10R is connected via a flow divider to the connection V of cylinder 9L and to the connection U of cylinder 9R. The outlet port Y of the valve 10R is connected via a flow divider to the connection U of cylinder 9L and to the connection V of cylinder 9R. Schematically, the hydraulic connections are as follows:

At the various nodes, the hydraulic conduits are (preferably) connected to each other by means of three-way (ball) valves dkk, which are used for the various operating modes of the levelling device according to the invention, as further indicated below.

The operation in the various operating modes is illustrated in Figures 2b-2d. In the figures, the hydraulic conduit sections provided with hydraulic pressure are indicated by lines with a greater line width than the other hydraulic conduit sections.

Figures 2c and 2d show the embodiment in which the hydraulic control system of the device is used for control from a (3D) tachymeter/total station control system that is coupled to the control valves 10. The tachymeter/total station control system controls the cylinders 9 on the left-hand side and right-hand side dependent on each other, in such a way that the straight or tilted orientation (tilt) of the scraper blade with respect to the (orientation of the sliding surface/drag surface of the) sliding shoe remains entirele fixed during the raising or lowering of the scraper blade; and/or in such a way that the height of (the centre of) the scraper blade with respect to the gliding shoe remains entirely fixed during the changing of the transverse orientation (the tilting) of the scraper blade.

Figure 2c shows the configuration in which the scraper blade 3 under control of the left control valve 10L (controlled from a (3D) tachymeter/total station control system) is moved up or down (raised/lowered) without changing the straight or tilted orientation of the scraper blade 3.

Figure 2d shows the configuration in which the scraper blade 3 under control of the right control valve 10R (controlled from a (3D) tachymeter/total station control system) is moved anticlockwise of clockwise (tilting) without changing the height of the centre of the scraper blade 3. It is noted, that the hydraulic system as shown in Figure 2a is set up either for control from a (2D) laser control system coupled to the control valves 10 (see Figure 2b), or for control from a (3D) tachymeter/total station control system coupled to the control valves 10 (see Figures 2c and 2d) by means of closing or opening the three-way (ball) valves ("dkk") provided at the nodes of the various hydraulic conduits.

Thus, the present invention provides for a levelling device in which - particularly important in the case of control from a (3D) tachymeter/total station control system - the functions of raising/lowering and tilting of the scraper blade are performed in such a way that the straight or tilted orientation of the scraper blade with respect to the gliding shoe remains entirely fixed during raising or lowering of the scraper blade. Furthermore, the height of (the centre of) the scraper blade with respect to the gliding shoe remains fixed during the variation of the transverse orientation (the tilting/tilting angle) of the scraper blade.