WO2023156334A1

WO2023156334A1 - Line marking apparatus with a spray fan width adjustable spray tool

Info

Publication number: WO2023156334A1
Application number: PCT/EP2023/053477
Authority: WO
Inventors: Lasse Thorfinn JAGD; Jens Peder Kvols KRISTENSEN
Original assignee: Tinymobilerobots Aps
Priority date: 2022-02-16
Filing date: 2023-02-13
Publication date: 2023-08-24
Also published as: DK181453B1; DK202200128A1

Abstract

The present invention relates to a line marking apparatus with a spray nozzle system that is easy adjust and which is less prone to get stuck in paint smear and splatter. The spray nozzle system comprises an adjusting mechanism adapted for adjusting the spray fan width of the paint exiting the tip of said spray nozzle. The adjusting mechanism comprises a pair of plates pivotably mounted on each side of the spray nozzle and each with a free end extending below the tip of said spray nozzle.

Description

Line marking apparatus with a spray fan width adjustable spray tool

Technical field of the invention

The present invention relates to line marking apparatuses adapted for marking or painting a surface.

Background of the invention

Mobile robots are now used as line marking apparatuses for marking surfaces. The mobile robot replaces tedious and hard manual marking operations done today e.g., at construction sites or sports fields, using strings and measurement tapes combined with aerosol cans and handheld markers.

The marking operation, and hence the formed mark(s), is used in construction for many purposes. It is used to mark the position and/or circumferences of geometrical figures, such as lines or symbols. It is also used for marking construction work to be done like paving, mounting of pillars and walls, and for installations for sewers, water, and electricity. As marking can be lines and symbols of varying width, the mobile robot needs to be able to handle such tasks. Line marking apparatuses with width adjustable and parallel spray shields do exist, but these solutions are difficult to adjust and, due to paint smear and splatter, often gets stuck.

It is an objective of the present invention to provide a line marking apparatus, preferably a mobile marking robot, that solves or at least minimizes the above- mentioned problems.

Description of the invention

One aspect relates to a line marking apparatus, such as a mobile marking robot, comprising:

- a chassis;

- a spray means comprising a spray nozzle with a tip;

- a paint reservoir operably connected to said spray means, thereby allowing paint from the paint reservoir to exit the tip of said spray nozzle; and

- an adjusting mechanism adapted for adjusting the spray fan width of the paint exiting the tip of said spray nozzle; wherein said adjusting mechanism comprises:

- a pair of plates pivotably mounted on each side of said spray nozzle and each with a free end extending below the tip of said spray nozzle; wherein said pair of plates are adapted for being pivoted between a first position with a first distance between their free ends to a second position with a second distance between their free ends.

This configuration result in a line marking apparatus with a spray nozzle system that is easy adjust and which is less prone to get stuck in paint smear and splatter.

The first and second distances are obviously different from one another. As an example, the plates’ free ends extend towards each other in the first position, while in the second position their free ends extend away from each other, including the position where the plates are positioned in parallel. In another example, the plates’ free ends extend towards each other in the first position, while in the second position their free ends still extend towards each other. In a further example, the plates’ free ends extend away from each other in the first position, while in the second position their free ends extend away from each other.

The line marking apparatus is preferably wheeled, such as a mobile marking robot, or a wheeled cart, such as e.g., a wheeled line marker. A line marker is a device or machine with which lines or markings are drawn on a sports field or pitch.

The term “chassis” is used herein to refer to at least a part of the main framework of the line marking apparatus, such as the main framework of a mobile marking robot.

The term “spray nozzle” is defined to be a nozzle, an orifice, a spray valve, a pressure reducing tubing section, and any combination thereof.

The adjusting mechanism comprises a pair of plates pivotably mounted on each side of said spray nozzle and each with a free end extending below the tip of said spray nozzle. The pair of plates are adapted for being pivoted between a first position with their free ends extending towards each other to a second position with their free ends extending away from each other. Different types of adjusting mechanisms for tilting the plates relative to one another may be suitable for the present invention, and a few non-limiting, but preferred, examples are mentioned in the following.

The adjusting mechanism may comprise two turn knob units each unit comprising a turn knob or the like, and wherein each plate is operably connected to each of said turn knob units. This configuration is less preferred as it is more difficult to adjust the position of the plates relative to one another, i.e. , to obtain the same angle.

Alternatively, the adjusting mechanism may preferably comprise a turn knob unit comprising a turn knob, or the like, and wherein each plate is operably connected to the turn knob unit. In this configuration, the turn knob unit is configured to, preferably synchronously, operate both plates. Preferably, the turn knob unit is configured to tilt the plates with the same angle of rotation, preferably synchronously. The turn knob or the like may e.g., be configured as a traditional turn knob, a handle that can be turned, a gear, or a belt pulley.

The distance between the free ends of the plates may preferably be varied between 5-200 mm, and if the line marking apparatus is for marking of sports fields preferably between 30-150 mm, such as 50-100 mm.

The below embodiments are in principle applicable to both above-described alternatives.

In one or more embodiments, the adjusting mechanism further comprises two guide arms, and wherein the plates are operably connected to the turn knob unit via their respective guide arm. If two turn knob units are present, the guide arms are operably connected to each (i.e. , their respective) turn knob unit.

The adjusting mechanism may further comprise a guide unit operably connected to the guide arms. Preferably, each guide arm comprises a guide pin, and wherein said guide unit comprises a guide slot adapted for receiving said guide pin. If two turn knob units are present, two guide units may preferably also be present.

In one or more embodiments, the guide slot is configured with closed ends (end stops), preferably thereby allowing the pair of plates to pivot/tilt a predefined number of degrees around their axis of rotation.

In one or more embodiments, the guide unit is adapted for either a) rotating right or left, b) moving vertically up or down, or c) moving horizontally back and forth, as the turn knob or the like of the turn knob unit is turned, respectively, in one direction or the other.

In one or more embodiments, the guide unit is adapted for rotating right or left as the turn knob or the like of the turn knob unit is turned, respectively, in one direction or the other.

In one or more embodiments, the guide unit is adapted for moving vertically up or down as the turn knob or the like of the turn knob unit is turned, respectively, in one direction or the other.

In one or more embodiments, the guide unit is adapted for moving horizontally back and forth as the turn knob or the like of the turn knob unit is turned, respectively, in one direction or the other.

In one or more embodiments, the guide unit is adapted for a) moving vertically up or down, or b) moving horizontally back and forth, as the turn knob of the turn knob unit is turned, respectively, in one direction or the other, wherein said guide unit comprises a first guide part and a second guide part slidably connected to one another, wherein the second guide part is, directly or indirectly, mounted to the chassis, and wherein the first guide part comprises said guide slots.

In one or more embodiments, the turn knob unit further comprises a threaded rod operably connected to the turn knob or the like, thereby allowing the turn knob or the like to rotate the threaded rod.

In one or more embodiments, the turn knob unit further comprises a motor unit adapted for turning the turn knob or the like.

When the line marking apparatus is a mobile marking robot, it will need to have a localization system telling the robot where it is, and how it is orientated, to be able to mark the data in an area. Furthermore, the data needs to be aligned to the locations system used by the robot. Most common used technologies for positioning are total stations and GNSS, but some solutions use advanced localization technologies together with cameras or lidars. The orientation of the mobile marking robot can be determined by having two independent location systems placed apart with enough distance to allow the robot to calculate its orientation. Another method of orientation is to let the robot drive a certain distance with one location system, and by driving, it can calculate its orientation. Aligning the robot’s localization with the digital data provided requires a shared coordinate system.

If the location system is global, like the GNSS, the global coordinates are sufficient for aligning the data and letting the robot start working.

In one or more embodiments, the positioning system is configured for continuously receiving a positioning signal from a Global Navigation Satellite System (GNSS). Global Navigation Satellite Systems (GNSS) is a collective term for a variety of satellite navigation systems, which use orbiting satellites as navigation reference points to determine position fixes on the ground. GNSS includes the Global Positioning System (GPS), the Global Navigation Satellite System (GLONASS), the Compass system, Galileo, and several Satellite based augmentation systems (SBAS). In typical civilian applications, a single GNSS receiver can measure a ground position with a precision of about ten meters. This is, in part, due to various error contributions, which often reduce the precision of determining a position fix. For example, as the GNSS signals pass through the ionosphere and troposphere, propagation delays may occur. Other factors, which may reduce the precision of determining a position fix, may include satellite clock errors, GNSS receiver clock errors, and satellite position errors. One method for improving the precision for determining a position fix is Real- Time Kinematic (RTK) GNSS. Real Time Kinematic (RTK) satellite navigation is a technique using the phase of the signal's carrier wave, rather than the information content of the signal, and relies on a single reference station or interpolated virtual station to provide real-time corrections. In one or more embodiments, the positioning system is configured for continuously receiving a positioning signal from a total station. The total station needs to use fix points to calculate its own position as well as the position of the mobile robot. The fix points can be reflectors placed beforehand at known coordinates or it can be fixed points in the construction like corners of walls or windows, that has known coordinates and can be used to localize the total station. The mobile marking robot may comprise a retroreflector. Any retroreflector with retroreflectors, generally known within the art of land surveying, may be used. In one or more embodiments, the retroreflector is a 360- degree all-around retroreflector.

In one or more embodiments, the positioning system is positioned on an elongate member extending upward from the chassis. In one or more embodiments, the elongate member is height adjustable, e.g., comprising telescoping elongate members, or the like.

If the localization system is cameras or lidars, several methods can be used. A common method is to let the robot move around and generate a map of the area. This map can then be used for positioning the robot.

In one or more embodiments, the spray means comprises an airbrush-based spray tool.

In one or more embodiments, the spray means comprises an inkjet-based spray tool, preferably based on a drop-on-demand technology.

In one or more embodiments, the spray means comprises a tool comprising an array of spray nozzles, such as 2-100 spray nozzles, preferably arranged either in a direction along the length of said chassis, or in a direction along the width of said chassis. In one or more embodiments, said tool is adapted for rotating said array of spray nozzles around a common pivot axis, preferably parallel to one or more pivot axes of said robot arm.

In one or more embodiments, the chassis comprises two differentially driven wheel in a fixed orientation and arranged on the same first axis line in parallel; and one off-centered orientable wheel arranged along a second axis line perpendicular to the first axis line, and in front or behind the first axis line.

The term “off-centered wheel” (castor wheel) is defined to be a wheel, where the vertical axis does not pass through the center of the wheel but is slightly off- centered. Some designs include a swivel joint (orientable) between the wheel and the fork so that it can rotate freely with 360° of freedom. The advantage with an off-centered orientable wheel compared to a centered orientable wheel is that the centered orientable wheel tends to lock in specific positions.

The mobile marking robot comprises a paint reservoir. The paint reservoir may be configured as a bag-in-box type reservoir, or simply as a replaceable bag reservoir, or a replaceable box reservoir.

In one or more embodiments, the spray means further comprises a return line through which paint can recirculate from a position upstream to the spray nozzle outlet and back to the paint reservoir. This configuration removes air from the paint and tubing, such that the spray nozzle will not splutter when painting a line.

In one or more embodiments, the spray means comprises means adapted for adjusting the drive mechanism and/or spray nozzle position in the vertical direction relative to the ground surface on which the mobile marking is robot moving.

In one or more embodiments, the spray means comprises a mechanism, such as a telescopic arm or the like, adapted for lowering and raising said spray nozzle(s) relative to the surface on which the mobile marking robot is moving. In one or more embodiments, the mobile marking robot further comprises a sensor configured for continuously determining the distance between said spray nozzle(s) and said surface, and wherein said control unit is configured to receive data about said distance from said sensor and in response thereto, change said distance by activating said mechanism to move said spray nozzle(s) relative to said surface. Distance sensors are well-known within the art and will thus not receive further attention.

In one or more embodiments, the control unit, in response to line width information about said geometric figure to be marked, is configured to continuously or periodically alter said line width by activating, i.e. , turning the .

In one or more embodiments, the differentially driven wheels are positioned near the rear end of the chassis, and wherein the off-centered orientable wheel is positioned near the front end of the chassis. Preferably, the off-centered orientable wheel is positioned equally distanced from each of the drive wheels.

As an example, an in order for the mobile robot to operate, the control unit may comprise a computing system including a processor, a memory, a communication unit, an output device, an input device, and a data store, which may be communicatively coupled by a communication bus. The mentioned computing system should be understood as an example and that it may take other forms and include additional or fewer components without departing from the scope of the present disclosure. For instance, various components of the computing device may be coupled for communication using a variety of communication protocols and/or technologies including, for instance, communication buses, software communication mechanisms, computer networks, etc. The computing system may include various operating systems, sensors, additional processors, and other physical configurations. The processor, memory, communication unit, etc., are representative of one or more of these components. The processor may execute software instructions by performing various input, logical, and/or mathematical operations. The processor may have various computing architectures to method data signals (e.g., CISC, RISC, etc.). The processor may be physical and/or virtual and may include a single core or plurality of processing units and/or cores. The processor may be coupled to the memory via the bus to access data and instructions therefrom and store data therein. The bus may couple the processor to the other components of the computing system including, for example, the memory, the communication unit, the input device, the output device, and the data store. The memory may store and provide data access to the other components of the computing system. The memory may be included in a single computing device or a plurality of computing devices. The memory may store instructions and/or data that may be executed by the processor. For example, the memory may store instructions and data, including, for example, an operating system, hardware drivers, other software applications, databases, etc., which may implement the techniques described herein. The memory may be coupled to the bus for communication with the processor and the other components of computing system. The memory may include a non-transitory computer-usable (e.g., readable, writeable, etc.) medium, which can be any non-transitory apparatus or device that can contain, store, communicate, propagate, or transport instructions, data, computer programs, software, code, routines, etc., for processing by or in connection with the processor. In some implementations, the memory may include one or more of volatile memory and non-volatile memory (e.g., RAM, ROM, hard disk, optical disk, etc.). It should be understood that the memory may be a single device or may include multiple types of devices and configurations. The input device may include any device for inputting information into the computing system. In some implementations, the input device may include one or more peripheral devices. For example, the input device may include the display unit comprising a touchscreen integrated with the output device, etc. The output device may be any device capable of outputting information from the computing system. The output device may be the display unit, which display electronic images and data output by a processor of the computing system for presentation to a user, such as the processor or another dedicated processor. The data store may include information sources for storing and providing access to data. In some implementations, the data store may store data associated with a database management system (DBMS) operable on the computing system. For example, the DBMS could include a structured query language (SQL) DBMS, a NoSQL DMBS, various combinations thereof, etc. In some instances, the DBMS may store data in multi-dimensional tables comprised of rows and columns, and manipulate, e.g., insert, query, update and/or delete, rows of data using programmatic operations. The data stored by the data store may be organized and queried using various criteria including any type of data stored by them. The data store may include data tables, databases, or other organized collections of data. The data store may be included in the computing system or in another computing system and/or storage system distinct from but coupled to or accessible by the computing system. The data stores can include one or more non-transitory computer-readable mediums for storing the data. In some implementations, the data stores may be incorporated with the memory or may be distinct therefrom. The components may be communicatively coupled by the bus and/or the processor to one another and/or the other components of the computing system. In some implementations, the components may include computer logic (e.g., software logic, hardware logic, etc.) executable by the processor to provide their acts and/or functionality. These components may be adapted for cooperation and communication with the processor and the other components of the computing system.

It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

Brief description of the figures

Figures 1 A and 1 B are schematic views of the general scheme of the invention. Figure 2 shows a perspective view of an adjusting mechanism in accordance with various embodiments of the invention.

Figure 3 shows a perspective view of an adjusting mechanism in accordance with various embodiments of the invention, where a front plate has been removed.

Figure 4 shows a perspective view of an adjusting mechanism in accordance with various embodiments of the invention, where the housing has been removed.

Figure 5 shows a front view of an adjusting mechanism in accordance with various embodiments of the invention, where a front plate has been removed.

Figure 6 shows a front view of an adjusting mechanism in accordance with various embodiments of the invention, where a front plate has been removed.

Figure 7 shows a perspective view of an adjusting mechanism in accordance with various embodiments of the invention, where the housing and a cover plate have been removed.

Figure 8 shows a perspective view of an adjusting mechanism in accordance with various embodiments of the invention.

Figure 9 shows a perspective view of an adjusting mechanism in accordance with various embodiments of the invention, where the housing has been removed. Detailed description of the invention

Referring to Figure 1 , the general scheme of the invention is shown. In general, a line marking apparatus, such as a mobile marking robot, comprises a chassis, a spray means comprising a spray nozzle with a tip, and a paint reservoir operably connected to the spray means, thereby allowing paint from the paint reservoir to exit the tip of the spray nozzle. In Figure 1 , the line marking apparatus is only represented by said spray nozzle 110 with a tip 112. A spray fan 120 is shown exiting the tip 112. The present invention is a new adjusting mechanism 200 adapted for adjusting the spray fan 120 width of the paint exiting the tip 112 of the spray nozzle 110. In Figure 1 , only the core component of the adjusting mechanism 200 is shown in the form of a pair of plates 210 pivotably mounted on each side of the spray nozzle 110 and each with a free end 212 extending below the tip 112 of the spray nozzle 110 and a hinged end 214 opposite to the free end 212. In Figure 1A, the pair of plates 210 are markedly pivoted/tilted towards each other to provide a relatively narrow spray fan 120. In Figure 1 B, the pair of plates 210 are almost positioned in vertical, thereby providing a relatively wide spray fan 120.

Different types of adjusting mechanisms 200 for tilting/pivoting the plates 210 relative to one another may be suitable for the present invention, and two nonlimiting, but preferred, examples are shown in Figures 3 (the first adjusting mechanism) and 8 (the second adjusting mechanism), where a protective front plate 290 (see Figure 2) has been removed to better show the individual components of the adjusting mechanism 200. Embodiments of the first adjusting mechanism is shown in Figures 2-7, and embodiments of the second adjusting mechanism is shown in Figures 8-9.

In general, both exemplified adjusting mechanisms comprises a turn knob unit comprising a turn knob 222 (only shown for the first adjusting mechanism), and wherein each plate 210 is operably connected to the turn knob unit. The turn knob unit is configured to synchronously tilt or pivot the plates 210 with the same angle of rotation. In order to do so, the adjusting mechanism further comprises two guide arms 230. Each of the plates 210 are operably connected to the turn knob unit via their respective guide arm 230. The adjusting mechanism further comprises a guide unit 240 operably connected to the guide arms 230. The guide unit 240 and the guide arms 230 are configured differently in the first and second adjusting mechanisms. The first adjusting mechanism functions by moving the guide unit 240 (here, a first part 242 of the guide unit) vertically up, or down (here, relative to the ground surface on which the paint is directed). If the same mechanism is used on a vertical wall, the apparatus, or a part thereof, including the first adjusting mechanism and spray nozzle 110, will be turned 90 degrees to direct the spray nozzle 110 towards the wall. In this situation, the guide unit 240 is moved horizontally back and forth, relative to the ground surface. Figure 6 shows how the different components move in response to turning the turn knob. The first adjusting mechanism functions such that a user can adjust the plates 210 limiting the spray fan width (hence, the line width on the surface) by turning the turn knob 222. The guide unit 240 is here shown comprising a first guide part 242 and a second guide part 244. The first guide part 242 is slidably connected to the second guide part 244, which is indirectly mounted to the chassis via a housing 250 also holding the plates 210. The turn knob unit also comprises a threaded rod 224 connected to the turn knob 222 and operably connected to a threaded channel in a part of the first guide part 242. By turning the turn knob 222, the threaded rod 224 will move the first guide part 242 along the threaded rod’s 224 longitudinal axis. Rotation is thereby converted to linear motion. The first guide part’s 242 movement is guided by the second guide part 244. The second guide part 244 is here shown as a guide rail, while the first guide part 242 is configured with a recess adapted for receiving the guide rail. The first guide part 242 is configured with guide slots/timing slots 243 guiding the arms 230 by a guide pin 236 at the end of each arm 230. The base of each arm 230 is attached to one of the plates 210, thereby converting the linear movement back to rotation of the plate 210. The plates 210 are thereby tilted by rotation. The threaded rod 224 and first guide part 242 also work as gearing and prevention of unintentional movement of the plates 210 if forces are applied to them. The gearing and self-locking mechanism is determined by the pitch of the threaded rod 224. In Figure 6, the pair of plates 210 are markedly pivoted/tilted towards each other to provide a relatively narrow spray fan 120. In Figure 5, the pair of plates 210 are pivoted/tilted away from each other, thereby providing a relatively wide spray fan 120. In Figures 4 and 7, the housing 250 has been removed to better show the plates 210. In Figure 7, a cover plate 252 has been removed to better show the connection between the arm 230 and the plate 210. The cover plate 252 is curved and attached to the upper part 214 (see Figure 1) of the plate 210, i.e. , opposite to the free end 212 (see Figure 1) of the plate 210. The cover plate 252 is present to avoid paint from escaping between the housing 250 wall and the plate 210.

Figures 8 and 9 show embodiments of the second adjusting mechanism. The second adjusting mechanism 200 functions by rotating the guide unit 240 right or left, as the turn knob of the turn knob unit is turned (not shown), respectively, in one direction or the other. The arms 230 comprises a first part 232 connected to the plate 210, and a second part connected to the guide unit 240. The first 232 and second 243 parts are connected in a joint capable of rotating in one dimension. Both arm’s second parts 234 are rotatably connected to the guide unit 240. Hence, as the guide unit 240 is rotated, the second parts 234 may e.g., be moved from a horizontal position along the same longitudinal axis (as shown) to oblique positions with parallel longitudinal axes. Here, rotational movement of the turn knob is transferred to rotational movement of the guide unit 240, which via the arms 230 is converted to rotational movement of the plates 210.

References

110 Spray nozzle

112 Tip

120 Spray fan

200 Adjusting mechanism

210 Plate

212 Free end

214 Hinged end

222 Turn knob

224 Threaded rod

230 Guide arm

232 First part

234 Second part

236 Guide pin

240 Guide unit

242 First guide part

243 Guide slot

244 Second guide part

250 Housing

252 Cover plate

254 Front plate

Claims

1. A line marking apparatus, such as a mobile marking robot, comprising:

- a chassis;

- a spray means comprising a spray nozzle (110) with a tip (112);

- a paint reservoir operably connected to said spray means, thereby allowing paint from the paint reservoir to exit the tip (112) of said spray nozzle (110); and

- an adjusting mechanism (200) adapted for adjusting the spray fan (120) width of the paint exiting the tip (112) of said spray nozzle (110); characterized in that said adjusting mechanism (200) comprises:

- a pair of plates (210) pivotably mounted on each side of said spray nozzle (110) and each with a free end (212) extending below the tip (112) of said spray nozzle (110); wherein said pair of plates (210) are adapted for being pivoted between a first position with a first distance between their free ends (212) to a second position with a second distance between their free ends (212).

2. The line marking apparatus according to claim 1 , wherein said adjusting mechanism (200) further comprises a turn knob unit comprising a turn knob (222), or the like, and wherein each plate (210) is operably connected to said turn knob unit.

3. The line marking apparatus according to claim 2, wherein said turn knob unit is configured to tilt the plates (210) with the same angle of rotation, preferably synchronously.

4. The line marking apparatus according to any one of the claims 2-3, wherein said adjusting mechanism (200) further comprises two guide arms (230), and wherein the plates (210) are operably connected to the turn knob unit via their respective guide arm (230).

5. The line marking apparatus according to claim 4, wherein said adjusting mechanism (200) further comprises a guide unit (240) operably connected to the guide arms (230), wherein each guide arm (230) comprises a guide pin (236), and wherein said guide unit (240) comprises a guide slot (243) adapted for receiving said guide pin (236).

6. The line marking apparatus according to claim 5, wherein said guide slot (243) is configured with closed ends, preferably thereby allowing the pair of plates (210) to pivot a predefined number of degrees around their axis of rotation.

7. The line marking apparatus according to claim 6, wherein the guide unit (240) is adapted for either a) rotating right or left, b) moving vertically up or down, or c) moving horizontally back and forth, as the turn knob (222) of the turn knob unit is turned, respectively, in one direction or the other.

8. The line marking apparatus according to claim 6, wherein the guide unit (240) is adapted for a) moving vertically up or down, or b) moving horizontally back and forth, as the turn knob (222) of the turn knob unit is turned, respectively, in one direction or the other, wherein said guide unit (240) comprises a first guide part (242) and a second guide part (244) slidably connected to one another, wherein the second guide part (244) is, directly or indirectly, mounted to the chassis, and wherein the first guide part (242) comprises said guide slots (243).

9. The line marking apparatus according to any one of the claims 2-8, wherein the turn knob unit further comprises a threaded rod (224) operably connected to the turn knob (222) or the like, thereby allowing the turn knob (222) or the like to rotate the threaded rod (224).

10. The line marking apparatus according to any one of the claims 2-9, wherein the turn knob unit further comprises a motor unit adapted for turning the turn knob (222) or the like.

11 . The line marking apparatus according to claim 1 , wherein said adjusting mechanism (200) further comprises two turn knob units each unit comprising a turn knob or the like, and wherein each plate (210) is operably connected to each of said turn knob units.