Spray unit with variable disc diameter

1 . A spray unit, comprising:

an axle;

a disc;

a disc shape modifying assembly; and

a liquid applicator;

wherein, the disc is configured to spin about the axle centered on the center of the disc;

wherein, the liquid applicator is configured to apply liquid to a surface of the disc;

wherein the disc shape modifying assembly is configured to modify a trajectory of liquid droplets that leave the spray unit by way of varying a diameter of the disc while the disc spins about the axle centered on the center of the disc.

2 . The spray unit according to claim 1 , wherein the disc shape modifying assembly comprises at least one movable geometry defining component configured to vary the diameter of the disc or a second disc by way of change of at least a part of the geometry defining component's position, and wherein the disc shape modifying assembly comprises at least one actuator configured to move the at least one geometry defining component.

3 . The spray unit according to claim 2 , wherein the disc shape modifying assembly comprises at least one geometry defining component selected from the group of a blade, an elastic film, and/or a slotted circular disc.

4 . The spray unit according to claim 3 , wherein the disc shape modifying assembly comprises at least two blades, each connected to the disc or the second disc by way of at least one blade pivot point, wherein the at least one actuator is configured to be connected to at least one of the two blades by way of a blade actuator linkage and wherein the at least two blades are configured to be connected by at least one inter-blade linkage.

5 . The spray unit according to claim 3 , wherein the disc shape modifying assembly comprises a concentric elastic film attached to the edge of the disc or the second disc, wherein the disc shape modifying assembly further comprises at least two extendable rods each connected to the disc or a second disc by way of at least one rod pivot point and to the elastic film wherein the at least two rods are configured to stretch or relax the elastic film equally in all radial directions wherein the at least one actuator is configured to be connected to at least one of the two extendable rods by way of a rod actuator linkage and wherein the at least two rods are configured to be connected by at least one inter-rod linkage.

6 . The spray unit according to claim 5 , wherein the at least two extendable rods of the disc shape modifying assembly comprise at least four extendable rods each connected to the disc or the second disc by way of the at least one rod pivot point and to the elastic film, wherein the at least two rods are configured to stretch or relax the elastic film equally in all radial directions wherein the at least one actuator is configured to be connected to at least one of the at least four extendable rods by way of the rod actuator linkage and wherein the at least four rods are configured to be connected by the at least one inter-rod linkage.

7 . The spray unit according to claim 5 , wherein the at least two rods are arranged in a substantially radial symmetrical disposition underneath the disc or underneath the second disc.

8 . The spray unit according to claim 2 , wherein the second disc is located axially spaced underneath the disc.

9 . The spray unit according to claim 3 , wherein the disc shape modifying assembly comprises at least one slotted circular disc configured to laterally surround the disc and thereby extend the diameter of the disc, wherein the at least one actuator is configured to control a position of the at least one slotted circular disc relative to the disc.

10 . The spray unit according to claim 9 , wherein the disc shape modifying assembly comprises at least two slotted circular discs, wherein the second slotted circular disc is configured to laterally surround the first slotted circular disc and wherein the at least one actuator is configured to control a position of the second slotted circular disc relative to the first slotted circular disc and/or the disc.

11 . The spray unit according to claim 1 , wherein the disc shape modifying assembly is configured to spin about the axle or a second axle.

12 . The spray unit according to claim 1 , wherein the disc shape modifying assembly is non-rotating.

13 . The spray unit according to claim 1 , wherein at least a part of a surface of the disc shape modifying assembly on which the liquid droplets impinge when leaving the outer edge of the disc has a low friction surface.

14 . A spray unit, comprising:

an axle;

a disc;

a disc shape modifying assembly, including:

at least one movable geometry defining component configured to vary a diameter of the disc or a second disc by way of change of at least a part of the geometry defining component's position; and

at least one actuator configured to move the at least one geometry defining component; and

a liquid applicator;

wherein the disc is configured to spin about the axle centered on the center of the disc;

wherein the liquid applicator is configured to apply liquid to a surface of the disc; and

wherein the disc shape modifying assembly is configured to modify a trajectory of liquid droplets that leave the spray unit by way of varying a diameter of the disc.

15 . A spray unit, comprising:

an axle;

a disc;

a disc shape modifying assembly; and

a liquid applicator;

wherein the disc is configured to spin about the axle centered on the center of the disc;

wherein the liquid applicator is configured to apply liquid to a surface of the disc;

wherein the disc shape modifying assembly is configured to modify a trajectory of liquid droplets that leave the spray unit by way of varying a diameter of the disc; and

wherein the disc shape modifying assembly is non-rotating.

16 . A spray unit, comprising:

an axle;

a disc;

a disc shape modifying assembly; and

a liquid applicator;

wherein the disc is configured to spin about the axle centered on the center of the disc;

wherein the liquid applicator is configured to apply liquid to a surface of the disc;

wherein the disc shape modifying assembly is configured to modify a trajectory of liquid droplets that leave the spray unit by way of varying a diameter of the disc; and

wherein at least a part of a surface of the disc shape modifying assembly on which the liquid droplets impinge when leaving the outer edge of the disc has a low friction surface.