SOWING DEVICE FOR LAWNS

SOWING DEVICE FOR LAWNS

The invention pertains to a device for sowing new seed, fertilizer or other products in an existing lawn, comprising: - a chassis, a movement system, fitted to the chassis, to move the device across the ground in a certain direction, a bearing-mounted pin disk in the chassis, fitted around a horizontal axis, a seed dosing device which doses the seed to be sown accurately and according to an adjustable amount,

- a guiding plate which at the bottom pushes the existing grass in the direction of flow and at the top distributes the dosed seed in rows and sends it to the pin disk, with the characteristic that the pin disk collects the dosed seed from the guiding plate and plants it in the soil underneath the lawn during rotation. Lawns are damaged by being used and as a result of environmental factors. Furthermore, an existing lawn ages, which means that new grass (seeds), fertilizer or other products are needed to recover the old lawn.

To maximize germination of the new grass seed, this grass seed must come into contact with the (fertile) soil underneath the existing lawn. Devices that can handle this process already exist. There are machines that make holes in the lawn, after which seed is sown across the entire width of the lawn and a brush is used to try and brush the grass seed into the prepared holes. However, the percentage of seed that ends up in the holes and comes into contact with the soil is small, as a result of which a lot of seed is lost and the desired result cannot be achieved. There are also devices on the market that cut or mill trenches in the soil, which are filled with grass seed, whether or not by opening these trenches. One disadvantage of this method is that the existing lawn is damaged and that ultimately, the grass comes up in a line pattern.

Also, the existing sowing devices have to deal with the grass stalks that stick out in all directions. These grass stalks often prevent the falling grass seeds to actually come into contact with the soil.

The invention claims to improve the germination percentage, reduce damage to the existing lawn and reduce the nuisance of the grass stalks. This is realised by first guiding the seed to the correct position by means of a funnel and by subsequently lifting it up with a rotating pen disk and pushing it into the soil. The seed is set into the soil as it were. The grass stalks of the existing lawn are pushed forward into the direction of flow, so as to reduce their interference with the sowing process to a minimum. Apart from the fact that the seed is set into the soil at the correct depth, the seed is actually pushed against the soil. This direct contact with the soil improves germination of the seed. After all, if the seed is sown into a prepared hole or trench, contact with the soil will be small. It is important for the seed to be pushed against the soil so that it can absorb moisture from the soil, germinate and take root.

As it is not always easy to press a pin disk into the soil due to its dead weight, the device is fitted with various pin disk combinations which have been bearing-mounted around cams that are attached - in a certain order - to the drive shaft in the horizontal plane. The pen disk rolls across the soil and is moved eccentrically in the vertical plane by means of the drive from the drive shaft with cams. This forward and backward eccentric movement will considerably improve the level of penetration of the pin disk, push the grass seed into the ground and bring it into contact with the soil.

The invention is to be described by means of the non-exhaustive operation example, represented in the following figures, where: figure 1 is a perspective, partly cut-away side view of the sowing device, according to a preliminary operation model of the invention, figure 2 is a side view, figure 3 is a schematic cross section of figure 1, figure 4 shows a schematic detail B of the pen disk which puts the seed into the soil through eccentric movement, figure 5 shows a schematic bird's eye cross section A-A from figure 3, Figure 1 gives a perspective view of the sowing device. The device comprises a main chassis (1) with a non-limitative mounting clamp (2), which is used to attach the device to a driving vehicle. The sowing device is available in different models, making it possible to attach it to a host of different driving vehicles.

The sowing tray (3) is filled with seed (4). The dosing roll (5) distributes the seed equally across the entire width. The dosing roll (5) is driven by means of a supporting roller (8). By changing the transmission ratio of the drive (7), the extent of the grass seed dose can be changed. The seed (9) which has been dosed across the entire width then slides down along the guiding plate (10) and is distributed in rows by the funnel plates (11). A number of cams (14) have been fixed solid and into a certain order onto the driven main shaft (15). Bearings (13) have been mounted around these cams. The pin disk (12) is linked to these bearings. The pin disk (12) can roll across the ground freely. In other words, if the device moves forward across the ground at a certain speed (6), the peripheral velocity (18) of the pen disk (12) will assume a similar speed. However, as soon as the main shaft (15) is driven (17), the pen disk (12) will also move eccentrically backwards and forwards (16) in the vertical plane. This eccentric movement causes the pin disk to vibrate, resulting in better penetration and the seed being pushed into the soil.

The pen disk (12) that vibrates in the vertical plane and rotates around the horizontal shaft collects the seed (9) which has been distributed in rows by the funnel plates (11). If the speed of rotation (18) of the pen disk exceeds the fall velocity of the seed (9), the seed (9) will be picked up by one of the pins of the pin disk (12). The pin disk continues to rotate, and both the pin and the seed are pushed into the soil. When the pin disk rolls along, the pins come out of the soil, leaving the seed in the soil (19), pressed against one side of the hole. An optional brush (20) can finish things off. A supporting roller (23) adjusts the device to the ground at the back. This supporting roller also closes up the prepared holes (21) so that one can hardly tell that seed has been sown on the lawn (22). Figure 2 gives a side view. The self-supporting sowing device can be attached to a driving vehicle by means of the mounting clamp (2). The supporting roller (8) drives the dosing roll (5) by means of gear transmission. Gear wheels 25, 25a, 25b, 25c, 25d and 25e are easily exchangeable, thus making it possible to change 1he amount of seed per metre covered. Figure 3 shows a cross section. The supporting rollers (8 and 23) adjust the device to the ground. The insertion depth D, figure 3, of the pin disk (12) can be changed by adjusting the supporting rollers (8 and/or 23).

Figure 4 gives a blown up version of detail B from figure 3. It also includes the vibrating movement of the pin disk (12). The driven cam (14) (figure 13) eccentrically moves the pin disk (12) backwards and forwards in the vertical plane between the outer ends (12a and 12c). When the pin (12d) goes in, the eccentric movement (26) will exert a force (27 and 28) on the seed. Force 27 ensures that the seed comes into contact with the soil, while force 28 pushes the seed into the soil, as angle C is larger than 90 degrees. Ultimately, the seed will become "stuck" at depth D. Depth D depends on the soil conditions, the positions of the supporting rollers (8 and 23) and the size and shape of the seed (9). When driving forward at speed (6), the peripheral velocity (18) of the pen disk (12) will assume the same value. After all, the bearing-mounted pin disk (12) is "driven" by the ground. It is important for the peripheral velocity (18) of the pin disk (12) to exceed the seed's fall velocity (29). To change the fall velocity (29) of the seed, angle E can be changed. This setting is important, because the size, shape and weight of the seed can differ and ultimately determine the fall velocity (29). The grass stalks (30) of the existing lawn are first pressed forwards by the supporting roller (18). Then the guiding plate (10) will press and hold the grass stalks forwards, so that the seed (9) is not obstructed by these upright grass stalks when the seed is pushed into the soil by the pin disk (12). Figure 5 shows a bird's eye cross section according to line A-A from figure 3. This shows, six pin disk combinations (34a-f) on the drive shaft (15). The six cams (14) have been fixed onto this drive shaft in a fixed order. This ensures an even run and regular penetration of the different pin disk combinations. The drive shaft (15) in the horizontal plane is bearing- mounted (33) in the main chassis (1) and is driven by the engine (32). It can be electrically or hydraulically driven, or by means of an external mechanical coupling spindle. One can also see that the seed (9) which has been dosed along the full width is distributed exactly in line with the pin disk (12) by means of the funnel plates (11).