GB2189411A - Paint stripe or road marking apparatus - Google Patents

Abstract

Apparatus for applying a sharp-edged paint stripe to a motor vehicle side moulding (3) or to effect road marking comprises a liquid spray dispenser (8); rotary discs (10), (11) positioned such that a length of the disc circumference, short with respect to its diameter, is disposed across the spray path from the liquid spray dispenser (8) to the substrate surface thereby partially masking the surface to produce a discrete liquid edge. Excess liquid is removed from the discs by pads or blades, <IMAGE>

Description

SPECIFICATION An apparatus for, and a method of, dispensing a liquid onto the surface of a body This invention relates to an apparatus and a method for dispensing a liquid, for example paint or an adhesive, onto the surface of a body and is more particularly, but not exclusively, concerned with an apparatus and a method for providing a stripe of paint or other liquid on an elongate body side moulding for a motor vehicle.

Until now, the only method whereby a coloured stripe may be applied to a vehicle body side moulding has been by co-extrusion of the body side moulding with a coloured element Although this technique has shown promising results in the past, it is a sophisti cated and rather costly technique in production.

Co-extrusion, therefore, is not attractive com mer cially.

Notwithstanding that, it is the case that co-extrusion has the advantage that it produces a product having a high quality appearance.lfthis high quality appearancecould be achieved bysimplyapplying painttothe body side moulding, this would considerably simplify the manufacturing process, thus significantly reducing the cost ofthe end product. The main problem is applying paint directly to a body side moulding or, indeed, the surface of any body, is in providing a stripe having sharp, discrete edges. To achieve this, it is necessary accuratelyto spray paint onto the surface of the body.

According to a first aspect ofthe present invention, there is provided an apparatusfordispensing a liquid onto the surface of a body, the apparatus comprising i) a liquid spray dispenser; ii) a disc which is capable of rotating about its axis and which is positioned such that a length of its circumference, short with respect to its diameter, is disposed across the spray path from the liquid spray dispenser to the surface thereby partially masking the surface to produce a discrete liquid edge; iii) means for rotating the disc about its axis; iv) means for removing from regions adjacentthe circumference ofthe disc any liquid which has accumulated thereon; and v) means for causing relative movement between the body and the apparatustherebyto present a continuously changing surface of the body to which liquid isto be applied.

According to a second aspect ofthe present invention there is provided a method for dispensing a liquid from a liquid spray dispenser onto the surface of a body to produce a layer of liquid having at least one discrete edge, which method comprises causing relative movement between the body and the liquid spraydispenserand interposing a length ofthe circumference of a rotating disc across the spray path, wherein the interposing length of circumference of the disc masks the surface to produce the discrete liquid edge and wherein the interposing length is short relative to the diameter of the disc.

The apparatus and method ofthe present invention enable paint, adhesive or any other sprayable liquid to be sprayed onto the surface of a body. As the application of paint to a body side moulding is of particular interest, much ofthefollowing description will refertothis particular application although it isto be appreciated that the apparatus and method are of much broader appiicability. Moreover, the painting of the decorative stripe in accordance with the present invention enables quick interchanging between col oursbysimplychangingthesupplyofpainttobe applied. The edge ofthe paint which has been masked by the rotating disc is very sharp and does not suffer from undesirable drawbacks such as a gradual thinning of paint atthe region ofthe edge.It is believed thatthistechniquewill match, or even improve, the finish of products produced in the past by coextrusion.

In preferred embodiments of the present invention, the apparatus for dispensing paint onto the surface of the body will includetwo discs, each disc being capable of rotating about its own axis and each being positioned on opposite sides ofthe spray path from the paint spray dispenser to the surface ofthe body to be painted. The length of circumference of each disc disposed in the spray path should be short with respectto the diameter of the disc. This ensures an essentially straight masking edge to produce a sharp, discrete paint edge on each side ofthe stripe of paint.

If it is assumed that the surface to be sprayed is horizontal, the discs may, in one embodiment, be mounted at an angle, preferably of about 100, inclined to the horizontal in such a way that the discs slope down towards the surface to be painted to reduce or prevent paint dusting and paint bouncing. The edges of the disc may also be bevelled to reduce or prevent the afore-mentioned paint dusting or bouncing. Typically, but not necessarily, the discs for the apparatus for applying a stripe of paint to a body side moulding will be in the range offrom 100 to 500 mm, preferably 300 mmindiameter butthey may be of any reasonable size which will depend on the scale of operation.

The discs may be rotated at any suitable rate although a presently preferred rate of rotation would be up to 75 rpm, preferably 30 rpm or 50 rpm, dependent in the disc diameter. In the apparatus comprising two discs,the rate of rotation need not be the same for both discs.

The spray dispenser may be any suitable paint spray gun although one particularly preferred spray gun is the pneumatic DeVilbiss spray gun developed and manufactured by the DeVilbiss Company Limited, of Bournemouth, Dorset, United Kingdom. The paint spray gun may, in one embodiment, be mounted such that its spray paint is sprayed onto the surface ofthe body in a direction perpendicularto the surface.

Alternatively, the paint spray gun may be mounted at an angle of, for example, 5"to the vertical; this may be of advantage if the paint isto be sprayed into an asymmetric recess.

The means for removing accumulated paint from The drawing(s) originally filed were informal and the print here reproduced is taken from a later filed formal copy.

regions adjacent the circumference ofthe disc may comprise a small soft pad disposed such that it cleans the edge region of the disc at some stage, preferably immediately downstream of where the edge ofthe disc has been in the spray path. Alternatively, the means for removing accumulated paint may comprise a sharp blade which scrapes or deflects the accumu lated paint away.

When the apparatus is stationary (apartfrom the rotation ofthe discs) and when the body is to be moved relatively to the apparatus, the means for removing the body relatively to the apparatus is preferably a conveyor belt. In the apparatus compris ing two discs, the conveyor belt is arranged to move the body symmetrically below the space between the discs. Of course, the means for moving the body relative to the apparatus will only be a conveyor in the situation where the body is an article such as a body side moulding of a car.It is envisaged thatthe body maybe a road, in which case the apparatus of the present invention can be used for dispensing paintfor road markings onto the surface of the road; in such an instance, the apparatus is likelyto include road wheels and the means for moving the body relative to the apparatus may be a motor driving one or more ofthe wheels.

In a preferred embodiment ofthe present invention, the apparatus comprises an adjustable frame, which may be made of steel, which carries the spray gun,the rotating discs and the means for driving the rotating discs. The frame may be mounted over the conveyor belt and is preferably rigidly locked overthe conveyor beltforaccuratespraying ontothemoving body.

The conveyor preferably includes guides to steer the strip (i.e. the body side moulding) along an accurate path belowthe space between the rotating discs. Moreover, a spring-loaded roller is preferably included to press down on the body moving on the conveyor belt in order to ensure thatthe body is driven along the conveyor belt ata constant speed. In the situation where the body is a body side mouldingfora car, including a recess to be painted, the roller may travel in the recess thereby assisting the guides in keeping the bodyto be sprayed in a straight line.

The roller may be on a small bridge overthe conveyor. The roller support may also include a revolving peg either side ofthe conveyor belt to restrain unwanted movement in the conveyor belt.

In the method of the present invention, using the apparatus as described above, it may be necessary to have more than one application of paint to obtain a reasonable finish. At present, it is believed thatthree applications of paint are sufficient. Thus three paintspraying stations, each with the associated pair of rotating discs, may be required, disposed in series along the conveyor belt.

When the apparatus is used to apply a stripe of paint onto an extruded body, the apparatus may be positioned immediately downstream ofthe extrusion die from which the extrudate emerges at a temperature of, for example, approximately 160"C. The painted extrudatethen passes through all the remaining processing steps to the finished product. Alternatively, the apparatus may be positioned downstream ofthe refrigerated coolingtankwhich cools the extrudate after emerging from the die. The extrudate may be at a temperature of about 1 5"C downstream of the cooling tank in which case there may need to be means for removing condensation from the surface of the extrudate before the paint is applied.

According to a further aspect ofthe present invention, there is provided an elongate body side moulding for a motor vehicle, having an elongate recess in which there is disposed a stripe of paint having sharp discrete edges.

The body side moulding will normally be manufac tured from a rubber or synthetic plastics material and is generally contoured to give an attractive three dimensional appearance. In preferred embodiments, the recess may be undercut into the main body ofthe moulding such that small lips extend along the edges of the recess.

The apparatus ofthe present invention may be employed to spray a stripe of an adhesive onto the surface of a body. The stripe of adhesive may then be covered with a quantity offlock material which will adhere to the adhesive. Because the edges of the stripe of adhesive will be very sharp, the flock material adhering to the adhesive will also have very sharp, discrete edges.

As mentioned above, the apparatus ofthe present invention may be adapted for road marking. Such an apparatus could include a number of wheels attached to a frame and a paint spraying rig supported on the frame. The wheels of the apparatus would enable the apparatusto move overthe road surface. The operation of the spray gun and the separation ofthe discs would preferably be controlled by a microp rocessorwhich could be programmed to spray specific signs or representations ontothe road such face.Moreover, the paint spraying rig could be mounted on the frame such that it would be movable with respect to the frame; in such an embodiment, it is envisaged that the apparatus could be positioned over the surface of a road onto which a representation isto be sprayed and the microprocessor, by controlling the discs and spray gun, and the position of the whole paint spraying rig on the frame, could accurately and quickly enable the representation to be painted on the road surface.

For a better understanding of the present invention and to show how the same may be carried into effect, reference will now be made, by way of example, to the accompanying drawings in which: Figure 1 shows, in plan, one embodiment of an apparatus for applying a stripe of paint onto the surface of a body side moulding for a motorvehicle; Figure 2 shows, schematically in elevation, another embodiment of an apparatus according to the present invention; Figure 3 illustrates a body side moulding for a vehicle, including a stripe of paint; and Figure 4 shows a partial view, in plan, from above the discs ofthe apparatus of Figure 1 towards the body side moulding onto which paint is being sprayed as a stripe.

In Figure 1,an apparatus 1 forapplying a stripe of paint 2to the surface of a body side moulding 3 comprises a paint rig 4 and a conveyor means 5 for moving the body side moulding 3 beneath the paint rig 4. The paint rig 4comprises a steel frame 6which steel frame 6 supports, by a steel limb 7, a paint spray dispenser 8. The steel frame 6 also includes limbs 8,9 which support metal discs 10, 11, each of which is rotatabie about its own axis. The two discs 10, 11 are mounted symmetrically between the conveyor means 5 and the paint spray dispenser 8.The discs 10, 11 are interposed in the spray path from the spray dispenser 8 to the surface of the body side moulding 3 and, because the length of circumference ofthe discs 10,11 which is in the spray path is short relative to the diameter of each disc 10, 11, the said length of circumference is essentially straight and the two discs present effectively parallel edges. These effectively parallel edges maskthe paint coming from the spray dispenser8to produce a very accurate stripe 2 on the body side moulding 3.

The discs 10, 11 are driven by motors (not shown) suchthatthe length of circumference in the spray path is travelling in the direction of movement ofthe conveyor (as shown by arrows 16). The discs may be rotated at any convenient rate but preferred values are 30 rpm or 50 rpm.

The body side moulding 3 emerges from an extruder onto the conveyor means Sand is guided through the paint rig 4 by guides 12,13 and 14,15 which steerthe body side moulding accurately beneath the rotating discs. The body side moulding may be passed through the paint rig 4 at a rate of, up to 150ft per minute (0.78 m/s), preferably about 75fit/ minute (0.39 m/s).

The body side moulding 3 is also pressed into contact with the conveyor means 5 by a spring-loaded roller 17 which engages the recess in the body side moulding 3 into which the paint isto be sprayed. The spring-loaded roller 17 is fixed to the paint rig 4 by a bridge 18.

In Figure 2, the paintspraydispenser8 includes a nozzle 28 through which paint 19 is sprayed onto the surface ofthe body side moulding 3. The rotating discs 10,11 are interposed in the spray path to mask parts of the body side moulding 3.The discs are angled at approximately 1 00to the horizontal. This provides a cleaner edge due to the paint fan angle in relation to the stripe to be painted. Moreover, the paint spray gun 8 is angled atabout5 tothevertical in view ofthe angle of the base ofthe recess.

In Figure 3, a body side moulding 3 includes a sharp edged stripe of paint 2 in a recess 21. The body side moulding 3 has lips 20 which overhang the recess 21.

The stripe of paint 2 in the recess 21 ofthe body side moulding 3 has very sharp, accurate, discrete edges.

In Figure4,the manner in which the paint is accurately sprayed onto the body side moulding 3 is illustrated. The rotating discs 10, 11 interruptthe sprayed paint 22 from the spray dispenser so to mask the areas ofthe body side moulding 3 to which paint is notto be applied. Because the lengths of circumference 23 of each disc 10,11 which are within the area of the spray 22 are short relative to the diameter of each disc 10, 11 ,the lengths ofthe circumference 23 in the spray path are essentially parallel. This ensures a sharp, accurate, discrete edge to the paint strip 2.

Claims (15)

1. An apparatus for dispensing a liquid onto the surface of a body, the apparatus comprising: i) a liquid spray dispenser; ii) a disc which is capable of rotating about its axis and which is positioned such that a length of its circumference, short with respect to its diameter, is disposed across the spray path from the liquid spray dispensertothesurfacethereby partially masking the surfaceto produce a discrete liquid edge; iii) means for rotating the disc about its axis; iv) means for removing from regions adjacent the circumference ofthe disc any liquid which has accumulated thereon; and v) means for causing relative movement between the body and the apparatus thereby to present a continuously changing surface of the body to which liquid isto be applied.

2. An apparatus according to Claim 1, comprising two discs, each capable of rotating about its axis, the discs being arranged to define a gap through which the liquid is sprayed onto the surface.

3. An apparatus according to claim 1 or 2, wherein the or each disc is inclined towards the spray path.

4. An apparatus according to Claim 1,2 or 3, wherein the edges ofthe or each disc is bevelled.

5. An apparatus according to any preceding claim, wherein the means for causing relative movement between the body and the apparatus is a conveyor means which conveys the body under the spray path.

6. An apparatus according to any preceding claim, wherein the body is stationary and the apparatus is movable over the body.

7. An apparatus according to any preceding claim, wherein the liquid is paint.

8. An apparatus according to any one of Claims 1 to 6, wherein the liquid is an adhesive.

9. A method for dispensing a liquid spray dispenser onto the surface of a body to produce a layer of liquid having at least one discrete edge, which method comprises causing relative movement between the body and the liquid spray dispenser and interposing a length of the circumference of a rotating disc across the spray path, wherein the interposing length of circumference of the disc masks the surface to produce the discrete liquid edge and wherein the interposing length is short relative to the diameter of the disc.

10. An elongate body side moulding for a motor vehicle, having an elongate recess in which there is disposed a stripe of paint having sharp discrete edges.

11. An elongate body side moulding according to Claim 10 madefrom rubber.

12. An elongate body side moulding according to Claim 10 made from a synthetic plastics material.

13. An elongate body side moulding according to Claim 10, 11 or 12, wherein the recess is undercut into the main body ofthe moulding.

14. An apparatus substantially as hereinbefore described, with reference to Figures 1 and 2.

15. An elongate body side moulding substantially as hereinbefore described, with reference to Figure 3.