Line marker

Abstract

A line marking machine includes: at least two wheels 12 for movably supporting the line marking machine on the ground; a spray nozzle 18 connected to a paint supply, for spraying paint onto the ground; and a line former, the line former including a disc 30 on either side of the spray nozzle 18, the plane of the disc being substantially perpendicular to the ground and each disc being rotatable on a substantially horizontal axis, characterised in that the line former is mounted for rotation on a substantially vertical axis C-C, and adapted to rotate about the vertical axis as the line marking machine turns in an arc.

Description

[0001] LINE MARKER

[0002] The present invention relates to a line marker, for marking lines for example on sports pitches, playgrounds, roads and car parks.

[0003] BACKGROUND TO THE INVENTION

[0004] Line marking machines are used, for example, to mark out sports pitches, courts, and car parks. The machines can be used on a range of surfaces, typically with the line marking paint being selected to suit the surface, for example different paints are used for turf, artificial grass, rubber, tarmac etc.

[0005] Some line markers work by transferring paint from a transfer wheel, whereas others spray the paint onto the surface. The spray can be a wet or a dry powder spray.

[0006] Marking machines range from simple “push along” manually controlled machines, to ride on machines which are typically powered by electric motors or for example a petrol engine. Automatic machines which are laser and / or GPS guided are also known. However these are sophisticated and expensive, and it is envisaged that many linemarking jobs will be done by a user-guided machine for the foreseeable future.

[0007] Spray marking machines often include a “line former”. This is essentially a shield at either side of the spray nozzle, to mask off the surface at either side of the line being painted and improve the definition of the line at its edges. The line former typically comprises a pair of discs, which may be rotatable, with the spray nozzle being disposed between the discs. Other types of line formers, including shaped stationary shields, are also available. In some known machines, the line former is in contact with the surface being marked. In others, the line former sits slightly above the surface.

[0008] Occasionally, line formers include only one shield, to one side of the spray nozzle. For example, a “single sided” line former may be used for marking a line at the edge of a railway platform.

[0009] Putting the line former in contact with the surface better masks off any overspray to either side of the line and so should provide a line with better definition. In these cases, the line former is typically in the form of a pair of rotatable discs which can trail along the surface just like wheels. However, there is a problem with line formers particularly when they are in contact with the ground, which is that when turning the marking machine in an arc or around a corner, the line formers tend to “scrub” the surface. This can produce badly defined lines with variable width and can also stress and / or damage the line formers.

[0010] This effect can be mitigated to some extent by placing the line former in between the wheels of the line marking machine. However, for user-guided machines this presents a problem because it makes it difficult to see the exact position of the line marking nozzle. Some line marking machines put the nozzle to the side of the machine, in line with the axle, but this is still not the optimal position from the point of view of a user who needs to look ahead while driving, while also accurately positioning the marking nozzle to paint an accurate line.

[0011] It is an object of the present invention to reduce or substantially obviate the aforementioned problems.

[0012] STATEMENT OF INVENTION

[0013] According to the present invention, there is provided a line marking machine, the line marking machine comprising: at least one wheel for movably supporting the line marking machine on the ground; a spray nozzle connected to a paint supply, for spraying paint onto the ground; and a line former, the line former including a disc at least on one side of the spray nozzle, the plane of the disc being substantially perpendicular to the ground and the or each disc being rotatable on a substantially horizontal axis, characterised in that the line former is mounted for rotation on a substantially vertical axis, and adapted to rotate about the vertical axis as the line marking machine turns in an arc.

[0014] By mounting the line former to allow it to rotate on a vertical axis, the discs of the line former can turn as the line marking machine turns. In other words, the discs of the line former act like a pair of steered wheels, and so do not scrub or drag when turning the corner. This avoids damage, and results in better line definition and consistent line width. As the line marking machine turns on its wheels, the line former also turns, following the line of the forward movement of the line marking machine.

[0015] In most embodiments, two discs are provided, a disc being provided on either side of the spray nozzle. The line marking machine according to the invention may advantageously have the spray nozzle and line former mounted at the front of the machine, in front of the wheel(s). For a user-guided machine this is a much more visible location than, for example, between the wheels or to the side but in line with the axle. The user is therefore able to better control the machine, mark a pitch more quickly and easily, and get a better result. Preferably, the spray nozzle and line former are mounted on an extension from the front of the machine. The spray nozzle and line former may be for example more than 200mm, more than 300mm, or even more than 500mm in front of the wheel(s) of the machine. In some embodiments, the extension from the front of the machine may be retractable by, for example, pivoting or telescoping. Therefore the spray nozzle and line former can be retracted towards the machine when not in use, making for compact storage and protecting the components from accidental damage, but can be deployed for use by extending them out to the front of the machine, to a position where their position can easily be seen by an operator who is standing behind the machine pushing it along, or sitting on the machine riding it, depending on the type of machine.

[0016] In one embodiment, the vertical axis about which the line former rotates is displaced forwards from the horizontal axis about which each disc rotates. The forward direction is defined as the direction in which the line marking machine is propelled when in use to mark a line. By displacing the vertical axis on which the line former is mounted forwards of the horizontal axis about which the discs rotate, the disc(s) act in a similar way to the casters on a shopping trolley, and will turn to follow the line of the turn of the line marking machine.

[0017] The discs are preferably independently rotatable on the horizontal axis and so the discs will turn as the line marking machine turns, with no scrub.

[0018] It will be appreciated that the axis on which the line former is mounted need not be exactly vertical. It is a vertical axis in the sense that it is a steering axis of the disc(s), and it is well known that a steering axis does not have to be, and often is not, exactly vertical. In other words there may be a caster angle. In some embodiments the caster angle may actually be variable, if the line former is mounted on a pivot to travel over uneven ground, as described in more detail below.

[0019] In some embodiments the disc(s) are “steered” only in the sense that they are free to track around to follow the line of the line marking machine, as described above where the vertical axis is displaced forwards of the horizontal axis. In other embodiments, the disc(s) could be truly steered for example by means of tie rods connected to the steering mechanism of the line marking machine. This may provide an advantage for example when working with uneven surfaces where the discs may sometimes not be in contact with the ground.

[0020] Preferably the disc(s) may be mounted to a framework, the framework for example including a crossbar and a pair of disc mounts extending from either end of the crossbar. In other words, the framework may be roughly U-shaped, or as three sides of a rectangle. The crossbar of the framework may be rotatably mounted on the vertical (steering) axis so that the two disc mounts rotate exactly together. A disc is then preferably rotatably mounted on a substantially horizontal axle at a distal end of each disc mount. Each axle is preferably a stub axle and the rotation of each axle is preferably independent, as the discs will rotate at different speeds as they turn a corner (the disc on the outside of the corner will rotate faster, as is well known). The two axles are preferably in line with each other along the same horizontal axis about which the discs rotate.

[0021] In some embodiments the spray nozzle rotates on the same vertical axis as the line former. The spray nozzle may for example be mounted under the crossbar of the framework, between the discs where there are two discs, or to one side of a single disc.

[0022] Preferably, the line formerand spray nozzle are mounted on a pivotable extension from the line marking machine. The extension may be pivotable on an axis which is substantially parallel with the ground, and perpendicular to the forward direction of travel of the line marking machine. The pivoting axis may be at one end of the extension, for example close to the (front) wheel(s) of the line marking machine, and the line former and spray nozzle may be mounted to the other end of the extension, the distal end from the machine. In this way, the line former and spray nozzle can be raised and lowered by pivoting. This allows the line former discs to be brought upwards so that they do not contact the ground when a line is not being marked. It also allows for a certain amount of movement over uneven terrain, so that the line former can remain in contact with the ground even if the ground directly under the line former is a slightly different height from the height of the ground directly under the wheel(s) of the line marking machine.

[0023] The line marking machine typically includes a tank for storing paint, a pump (typically battery-operated) for pumping the paint from the tank to the spray nozzle, and tubing to deliver the paint to the spray nozzle. The line marking machine has at least one wheel but preferably has at least two or at least four wheels. The line marking machine is essentially a vehicle which transports the tank of paint while allowing precise control of the position of the spray nozzle over the ground. The line marking machine may be a push-along machine or a ride-on machine. Either type of machine may be propelled manually (for example, by pushing along in the case of the push-along or by pedals in the case of the ride-on machine). In some embodiments machines may be powered, i.e. the wheels may be driven by for example an electric motor or internal combustion engine. Even a push-along machine may be power-assisted, similar to power-assisted lawnmowers.

[0024] Some embodiments of line marking machines according to the invention may be fully or partially autonomous guided machines, which drive themselves guided by, for example, embedded cables, GPS, or other guide technology. In these cases the visibility of the position of the spray nozzle to the user is less critical. However, the invention still brings advantages in terms of less scrub and better line definition when marking arcs.

[0025] According to a second aspect of the invention, there is provided an attachment for a trolley or vehicle, the attachment comprising: a spray nozzle connected to a paint supply, for spraying paint onto the ground; and a line former, the line former including a disc at least on one side of the spray nozzle, the plane of the disc being substantially perpendicular to the ground and the or each disc being rotatable on a substantially horizontal axis, characterised in that the line former is mounted for rotation on a substantially vertical axis, and adapted to rotate about the vertical axis as the line marking machine turns in an arc.

[0026] In most embodiments, two discs are provided, a disc being provided on either side of the spray nozzle.

[0027] The attachment can be mounted to any suitable vehicle or trolley which can be pushed or ridden along. A paint supply can be provided on the vehicle I trolley and suitably connected to the spray nozzle. The vehicle or trolley is hence effectively converted into a line marking machine suitable for marking out, for example, a sports pitch. Preferable I optional aspects of the first aspect of the invention are set out in claims 2 to 17.

[0028] Preferable I optional aspects of the second aspect of the invention are set out in claims 19 to 23.

[0029] It will be appreciated that any feature or independently selected combination of features presented with respect to one aspect of the invention may be provided in the other aspect of the invention.

[0030] BRIEF DESCRIPTION OF THE DRAWINGS

[0031] For a better understanding of the present invention, and to show more clearly how it may be carried into effect, reference will now be made by way of example only to the accompanying drawings, in which:

[0032] Figure 1 is a perspective view from in front of a line marking machine according to the invention;

[0033] Figure 2 is a detailed view of an attachment including a line former, which forms part of the line marking machine of Figure 1 , pivoted so that discs of the line former contact the ground in an operational position; and

[0034] Figure 3 is a detailed view of the attachment of Figure 2, pivoted so that discs of the line former are spaced from the ground in a non-operational position.

[0035] DESCRIPTION OF PREFERRED EMBODIMENTS

[0036] Referring firstly to Figure 1 , a line marking machine is indicated generally at 10. In this embodiment, the line-marking machine is in the form of a ride-on quadricycle, having a pair of front wheels 12 and a pair of rear wheels 14. The front wheels 12 are steered by handlebars (not visible in Figure 1) in a conventional way.

[0037] Extending from the front of the line marking machine 10, a pivoting extension 20 is provided. The extension pivots about pivot axis A-A which is parallel with the ground and perpendicular to the line of travel of the line marking machine. In other words, the axis A-A runs across the width of the line marking machine, from one lateral side to the other. By pivoting the extension 20 about axis A-A, at the end of the extension which is proximal to the line marking machine 10, the distal end of the extension is moved up and down, as indicated by arrow B. The distal end of the extension can therefore be brought closer to the ground, or further away from the ground. Preferably, the pivoting of the extension can be controlled for example by a lever mounted on the handlebars via cables, linkages, and the like.

[0038] A framework 22 is mounted to a distal end of the pivoting extension 20. The framework 22 is mounted on a pivot 24 so that the framework may pivot about axis C-C. Axis C- C is substantially vertical when the extension is pivoted to a lowered position as shown in Figure 1. However, it will be appreciated that since the extension 20 can pivot on a horizontal axis, the angle of the axis C-C from the vertical will vary. When the extension is in a lowered position axis C-C is substantially vertical in the sense that it is a workable steering axis, but the “lowered position” may in fact not be one specific angle of the extension 20 with respect to the frame of the line marking machine, because when used on uneven ground the ground may be at different heights under front wheels 12 and under the distal end of extension 20.

[0039] The framework 22 comprises a crossbar 26, which is substantially horizontal (or at least, substantially perpendicular to axis C-C). It is the crossbar 26 which is mounted to the distal end of the extension 20 on the pivot 24. The framework 22 further comprises a pair of disc mounts 28. Each disc mount extends downwardly and slightly backwardly from an end of the crossbar 26, one disc mount 28 extending from each end of the crossbar. Accordingly the framework is shaped as three sides of a rectangle.

[0040] A pair of discs 30 are mounted to the framework 22. Each disc 30 is mounted to a respective disc mount 28. Each disc 30 is mounted to its associated disc mount on a stub axle, so that the discs 30 can rotate independently of each other. The stub axles are in-line, so that the two discs 30 rotate on a common axis. The axis about which the discs rotate is substantially horizontal (i.e. parallel with the ground). The axis of the rotation of the discs moves as the framework 22 pivots with respect to the extension 20 on the substantially vertical axis C-C. However it remains substantially in a horizontal plane.

[0041] The stub axles extend outwardly from their respective discs, so that there is a space in between the two discs 30. A nozzle 18 is mounted between the discs. Preferably, the nozzle is mounted on the framework 22 so that the nozzle 18 and discs rotate about axis C-C together. The nozzle is adapted to deliver paint to a ground surface (e.g. grass, tarmac, etc.) in a known manner. The line marking machine carries a paint supply in a tank, and a pump (preferably a battery-powered electric pump). The user can control the pump to deliver paint through a tube 16 to the nozzle 18 by, for example, a switch mounted on the handlebars.

[0042] Note that in other embodiments, the line marking machine may be a push-along machine (i.e. without a seat for riding on). Either a push-along machine or a ride-on machine may be powered, for example by an electric motor or a petrol engine. Whether powered or not, for a user guided machine it is preferable for the nozzle 18 to be clearly visible by being spaced on the extension in front of the machine. Other embodiments may be fully or partly automated, for example using GPS to guide the machine to mark out a sports pitch automatically.

[0043] Referring now to Figure 2 and Figure 3, it can be seen more clearly how the disc mounts 28 extend not only downwardly, but backwardly, from either end of the crossbar 26 of the framework 22. This means that the stub axles on which the discs 30 rotate are displaced backwardly from axis C-C. In other words, the axis of rotation is displaced horizontally from the steering axis, just like a castor on a shopping trolley. The effect of this is that the discs 30 will steer themselves to follow the line of travel of the line marking machine. Figure 2 shows the position of the discs when the line marking machine is travelling in a straight line; Figure 1 shows the position of the discs when the line marking machine is turning a corner. This avoids any “scrub” and results in a better definition of the line being marked.

[0044] Because of the way the discs 30 are mounted, with a displaced axle, i.e. as a caster, no tie rods or steering mechanism are required associated with the discs 30. The nozzle 18 is positioned between the discs to deliver paint between the discs, and the discs mask off spray to either side to ensure a sharp line, including when marking an arc.

[0045] Because the discs 30 and nozzle 18 are mounted on an extension, in front of the line marking machine, they are easily visible to the user. In this particular embodiment the user is riding on the machine which is in the form of a quadricycle, and is looking forward as he or she rides the vehicle. The position of the nozzle 18 on the extension 20 is very convenient and allows the user to easily and accurately guide the line marking machine. In prior art machines, such a position would lead to an unacceptable level of disc scrub, but this problem is mitigated by allowing the discs to pivot on axis C-C as described. Figure 3 shows the extension 20 pivoted upwards into the out-of-use position. In this position the discs 30 are not in contact with the ground. This position is therefore useful when not marking, to ensure that paint from the discs is not transferred to the ground when no mark is to be made. In some embodiments, the pivoting extension may also provide some suspension for the discs 30. For example, the pivoting extension may be spring-loaded to urge the discs towards the ground, but allow them to move on the pivot where the terrain is uneven, i.e. where the ground level may be different below the front wheels 12 of the line marker compare with below the discs 30. This advantageously ensures that the discs 30 remain in contact with the ground, so that they will be steered by the caster effect as described.

[0046] The embodiments described above are provided by way of example only, and various changes and modifications will be apparent to persons skilled in the art without departing from the scope of the present invention as defined by the appended claims.

Claims

CLAIMS1. A line marking machine, the line marking machine comprising: at least one wheel for movably supporting the line marking machine on the ground; a spray nozzle connected to a paint supply, for spraying paint onto the ground; and a line former, the line former including a disc at least on one side of the spray nozzle, the plane of the disc being substantially perpendicular to the ground and the disc being rotatable on a substantially horizontal axis, characterised in that the line former is mounted for rotation on a substantially vertical axis, and adapted to rotate about the vertical axis as the line marking machine turns in an arc.

2. A line marking machine as claimed in claim 1 , in which the spray nozzle and line former are mounted at the front of the machine, in front of the wheel(s).

3. A line marking machine as claimed in claim 2, in which the spray nozzle and line former are mounted on an extension in front of the machine.

4. A line marking machine as claimed in claim 2 or claim 3, in which the spray nozzle and line former are mounted more than 200mm, preferably more than 300mm, or more preferably more than 500mm, in front of the wheel(s) of the line marking machine.

5. A line marking machine as claimed in any of the preceding claims, in which the substantially vertical axis about which the line former rotates is displaced forwards of the horizontal axis about which each disc rotates.

6. A line marking machine as claimed in any preceding claim, in which there is a second disc provided on the other side of the spray nozzle.

7. A line marking machine as claimed in claim 6, in which each disc is rotatable independently of the other.

8. A line marking machine as claimed in claim 6 or claim 7, in which each disc rotates on the same horizontal axis.

9. A line marking machine as claimed in any of the preceding claims, in which the spray nozzle is mounted for rotation about the same vertical axis as the line former.

10. A line marking machine as claimed in any preceding claim, when dependent on claim 3, in which the extension is pivotable with respect to the line marking machine, on a pivot axis which is substantially parallel with the ground and perpendicular to the forward direction of travel of the line marking machine.

11. A line marking machine as claimed in any of the preceding claims, further comprising a tank for storing paint, a pump for pumping the paint from the tank to the spray nozzle, and tubing to deliver the paint to the spray nozzle.

12. A line marking machine as claimed in any of the preceding claims, having at least four wheels.

13. A line marking machine as claimed in any of the preceding claims, the line marking machine being a user-guided push-along machine.

14. A line marking machine as claimed in any of the preceding claims, the line marking machine being a user-guided ride-on machine.

15. A line marking machine as claimed in any of the preceding claims, the line marking machine being a pedal-powered ride-on machine.

16. A line marking machine as claimed in claim 15, in the form of a ride-on tricycle.

17. A line marking machine as claimed in claim 15, in the form of a ride-on quadricycle.

18. An attachment for a trolley or vehicle, the attachment comprising: a spray nozzle connected to a paint supply, for spraying paint onto the ground; and a line former, the line former including a disc at least on one side of the spray nozzle, the plane of the disc being substantially perpendicular to the ground and the disc being rotatable on a substantially horizontal axis, characterised in that the line former is mounted for rotation on a substantially vertical axis, and adapted to rotate about the vertical axis as the line marking machine turns in an arc.

19. An attachment as claimed in claim 18, in which the substantially vertical axis about which the line former rotates is displaced forwards of the horizontal axis about which the disc rotates.

20. An attachment as claimed in claim 18 or claim 19, in which there is a second disc provided on the other side of the spray nozzle.

21. An attachment as claimed in claim 20, in which each disc is rotatable independently of the other.

22. An attachment as claimed in claim 20 or claim 21, in which each disc rotates on the same horizontal axis.

23. An attachment as claimed in any of claims 18 to 22, in which the spray nozzle is mounted for rotation about the same vertical axis as the line former.

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