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Title:
FLAME-SPRAYER FOR SPRAYING CURBS
Document Type and Number:
WIPO Patent Application WO/2001/071097
Kind Code:
A1
Abstract:
The present disclosure relates to examples of improved flame sprayers that are suitable for painting curbs. The flame sprayer includes a body portion having rollers, for example wheels, such that the flame sprayer can roll along a pavement or curb. The flame sprayer also includes a spray nozzle that can be coupled to a thermal powder reservoir. The powder is discharged along an imaginary axis, or the discharge axis, which extends from the spray nozzle. The spray nozzle is connected to the body portion such that the discharge axis is angled outwardly and away from the side of the flame sprayer so that the nozzle is directed at the curb.

Inventors:
Kusilek, Thomas V. (P.O. Box 33427 Saint Paul, MN, 55133-3427, US)
Mcauley, James P. (P.O. Box 33427 Saint Paul, MN, 55133-3427, US)
Application Number:
PCT/US2000/024331
Publication Date:
September 27, 2001
Filing Date:
August 31, 2000
Export Citation:
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Assignee:
3M INNOVATIVE PROPERTIES COMPANY (3m Center P.O. Box 33427 Saint Paul, MN, 55133-3427, US)
International Classes:
E01C23/20; (IPC1-7): E01C23/20
Foreign References:
US3393615A1968-07-23
US2815983A1957-12-10
US3874801A1975-04-01
US2401431A1946-06-04
Attorney, Agent or Firm:
Hofmann Jr., Rudolph P. (Office of Intellectual Property Counsel P.O. Box 33427 Saint Paul, MN, 55133-3427, US)
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Claims:
What is claimed is:
1. A flame sprayer for spraying a curb, the flame sprayer comprising: a body portion, the body portion having rollers such that the flame-sprayer is adapted for travel along a direction, the body portion having an associated longitudinal side wherein the longitudinal side is generally along the direction of travel; and a spray nozzle suitable for attachment to a thermal powder reservoir, the spray nozzle having an associated discharge axis ; wherein the spray nozzle is connected to the body portion such that the discharge axis is angled to intersect the longitudinal side.
2. The flame sprayer of claim 1 wherein the rollers include three wheels.
3. The flame sprayer of claim 1 wherein the body portion includes the thermal powder reservoir.
4. The flame sprayer of claim 1 and further comprising a wind screen generally surrounding the spray nozzle.
5. The flame sprayer of claim 4 wherein the wind screen includes a generally planar and open end, wherein the generally planar and open end is adapted to be proximate the curb.
6. The flame sprayer of claim 1 wherein the discharge axis is angled downward at 26 degrees.
7. A flame sprayer suitable for spraying a pavement and curb, the flame sprayer comprising: a body portion having a set of wheels such that the flame sprayer is adapted for travel along a direction, the body portion having an associated longitudinal side wherein the longitudinal side is generally along the direction of travel; a flame spray assembly, including: a spray nozzle coupled to a thermal powder reservoir, the spay nozzle having an associated axis of discharge, and a wind screen generally surrounding the spray nozzle, the wind screen having an open end; a frame connected to the body portion, the frame having a leading member; and an angled bracket attached to the leading member and connected to the flame spray assembly at the windshield; wherein the spray nozzle is oriented such that the axis of discharge intersects the longitudinal side and wherein the open end of the wind screen is adapted to be proximate the curb.
Description:
FLAME-SPRAYER FOR SPRAYING CURBS Background The present disclosure relates to flame sprayer devices for use in spraying or painting roadways. More specifically, the present disclosure relates to flame sprayers that are particularly suited to spraying or painting curbs.

Pavement and curb markings alert drivers to road changes, and are used as delineators to facilitate the orderly flow of traffic. Pavement markings include lane separation lines, edge lines, turn lane lines, school zones, parking lots, crosswalks, and many others. Curb markings, painted on the side and top of curbs, indicate bus stops, no parking zones, loading zones, fire lanes, fire hydrants, parking zones for the disabled, and many others. These markings, which often appear to be paint, are subject to environmental conditions, oil, grease, dirt, and wear, and the markings tend to lose their effectiveness over time. Accordingly, municipalities or other entities must maintain and frequently reapply markings.

One common device for applying or reapplying markings is known in the art as a"flame-sprayer."The flame-sprayer ignites a fuel such as propane to heat a thermal powder sprayed from a nozzle. The thermal powder is thus converted into a"paint" that readily adheres to a pavement surface. Flame-sprayers have been used for decades as pavement markers. Flame-sprayers are easy to use and maintain, and are inexpensive to operate. The nozzle is fixed so as to be directed downward and toward the pavement surface. An operator rolls the flame sprayer along the pavement as the flame sprayer sprays the pavement.

Flame sprayers, however, are not effective at painting curbs. The flame sprayer can paint the pavement proximate a curb, but is not designed to paint the curb itself, which is raised above the pavement surface. In order to paint curbs, municipalities or others use common painting techniques such as paint buckets and brushes, paint rollers, or handheld power-painter devices. The techniques used to paint curbs are not as efficient as the flame sprayer for painting pavement surfaces. For example, the actual cost of painting a length of curb can be over twice the cost of spraying the same length of pavement. Municipalities have long recognized the benefits of painting curbs, but have also long sought a way to reduce the high cost painting curbs. Money saved in

applying and reapplying curb markings can then be put to use in other state and municipal programs or returned to the taxpayer as a tax cut.

Summary The present disclosure relates to examples of improved flame sprayers that are suitable for painting curbs. The improved flame sprayers are easy and inexpensive to operate and maintain. The cost of painting a length of curb with the improved sprayers can be up to half of the cost per same length of curb painted with prior art techniques.

Accordingly, municipalities using the improved flame sprayers can realize substantial savings while maintaining traffic markings.

The flame sprayer includes a body portion having rollers, for example wheels, such that the flame sprayer can roll along a pavement or curb. The flame sprayer also includes a spray nozzle that can be coupled to a thermal powder reservoir. The powder is discharged along an imaginary axis, or the discharge axis, which extends from the spray nozzle. The spray nozzle is connected to the body portion such that the discharge axis is angled outwardly and away from the side of the flame sprayer so that the nozzle is directed at the curb.

Brief Description of the Figures Fig. 1 shows a perspective view of an example of a flame sprayer constructed in accordance with the present invention.

Fig. 2 shows a plan view of the flame sprayer of Fig. 1.

Fig. 3 shows an elevation view of the flame sprayer of Fig. 1.

Detailed Description The disclosure relates to a flame sprayer for spraying curbs. The disclosure, including the figures, describes the raised pavement markers with reference to a few examples. The scope of the invention is not limited to the few examples, i. e., the described embodiments of the invention. Rather, the scope of the invention is defined by the appended claims. Changes can be made to the examples, including alternative designs not disclosed, so as to still fall within the scope of the claims.

Fig. 1 shows an application of one example of a flame sprayer 10. The flame sprayer 10 rolls along the surface of a pavement 12 and proximate a curb 14 and

deposits a film or paint on the top and sides of the curb 14. The flame sprayer includes a body portion 16, a frame 18 attached to the body portion 16, and a flame spray assembly 20 connected to the framel8, the body portion 16, or both. In an example of operation of the flame sprayer 10, the flame spray assembly 20 mixes a fuel such as propane with compressed air to make a high velocity combustible gas stream. A thermal powder, often premixed with reflective glass spheres, is aspirated into the gas stream where the fuel mixture is ignited. The fuel mixture is directed outwardly toward the curb 14 and not downwardly and directly at the pavement surface 12. The resulting flame preheats the curb 14 and pavement 12 surface and deposits a film of molten thermal powder that hardens on the curb 14. This example describes in general the operation, those skilled in the art will recognize that modifications can be made to this example.

The flame sprayer 10 includes a body portion 16 attached to rollers 22. The rollers 22 in the example are carriage wheels or semi-pneumatic rubber, ball bearing wheels. Other examples of rollers, such as tracks, or the like, are contemplated. The wheels 22 in the example permit the flame sprayer 10 to roll along the pavement surface 12 in a selected direction of travel. The operator stands proximate the backside 24 which is opposite the front side 26. Also identified on the figure is a longitudinal side 28 and body sides 29,30. In the example, an operator will stand proximate the back side 24, grasp the handles 32, and push or pull the flame sprayer 10. The flame sprayer 10 can also be self-propelled. The body portion 16 of the example includes controls 34 that can include gauges, levers, valves, or the like, so the flame sprayer 10 can deposit the film on the curb 14. The body portion 16 is also adapted to hold a propane gas tank, such as a typical twenty-pound tank. The body portion is also adapted to be coupled to an air supply, such as an air hose connected to a remote air compressor.

The flame sprayer can travel forward, backward or turn, or the like, and the longitudinal side 28, and body sides 29,30 in the example are generally along the direction of travel, or (approximately) tangential to the direction of travel (for descriptive purposes). In the example, the body portion 16 is rectangular such that body side 29 is generally planar. Other examples are contemplated where the body portion 16 is not rectangular or that the actual side 29 of the body portion 16 is not oriented to be tangential to or along the direction of travel. Examples of this are if the

body portion was triangular, trapezoidal, rounded, and many others. In these cases, the longitudinal side is"associated"with the body portion. That is, an associated longitudinal side is a conceptual plane that is tangential to or along the direction of travel where that plane contacts the body portion, intersects the body portion, is coplanar with the body side or is merely proximate the body portion. In the example shown, the longitudinal side 28 is proximate to the body portion 16.

In the example shown, the frame 18 is connected to the body portion 16.

Alternative flame sprayers need not include a frame. The frame 18 of the example includes a leading member 19 and a trailing member 21, which are both generally perpendicular to the longitudinal side 30 and generally parallel to the pavement surface 12. Other configurations are possible. A third wheel 23 is attached to the frame 18. In one example, the frame is formed of steel welded and bolted together and to the body portion 16 and flame spray assembly 20.

The flame spray assembly 20 includes a spray nozzle 40 (shown in phantom) that is generally surrounded by a wind screen 42. In the example shown, the flame sprayer 10 includes a thermal powder reservoir 44 that is attached to the spray nozzle 40. In other example, the thermal powder reservoir can be remote from the flame prayer 10 but in communication with the spray nozzle 40. In the example shown, the thermal powder reservoir 44 is a hopper 46. The hopper 46 is in communication with a flow control valve 48. The metering valve 50 is also connected to the flow control valve 48 and is operated by controls to provide a selected flow of thermal powder through the flow control valve 48 and into gun block 52. Airline 54 and propane line 56 are connected to the gun block to mix with and aspirate the thermal powder in the gun block 52. The gun block is in direct fluid communication with the spray nozzle 40.

A vibrator 58 connected to a second air line 60 is coupled to the gun block 52 to assist the flow of the aspirated thermal powder into the spray nozzle 40. The spray nozzle 40 in the example terminates within wind screen 42. A pilot 62, in communication with the propane tank via line 64, also terminates within the wind screen 42 (the wind screen includes an aperture 66 to light the pilot 62) and ignites the aspirated thermal powder mixture to form the film or paint.

An axis of discharge 68 is associated with the spray nozzle 40. The axis of discharge, or discharge axis, 68 represents the main direction of the spray of thermal powder film from the spray nozzle 40. Typically, the spray will spread away from the

axis of discharge 68 as the thermal powder moves away from the spray nozzle 40. But the axis of discharge 68 can represent the main intended direction of discharge where the spray was focused, i. e., where the spray is aimed. (By analogy, the axis of discharge is similar to a line extending down the barrel of a shotgun). In the example shown, the axis of discharge 68 follows and extends the line of the spray nozzle 40, but alternatives are contemplated. For example, if the nozzle 40 included a tip or elbow, or the like, that would direct the spray, the associated axis of discharge 68 would correspond to the direction of spray.

The spray nozzle 40 is attached to the sprayer 10 proximate the longitudinal side 28 so that the axis of discharge 68 intersects the longitudinal side 28. In operation, the axis of discharge 68 also intersects the roadway proximate the curb 14. The axis of discharge is considered to intersect the longitudinal side even when the spray nozzle extends through the longitudinal side 28 because the longitudinal axis is considered to be an imaginary line extending in the direction of spray and opposite the direction of spray. In the plan view of the example shown in Fig. 2, the axis of discharge 68 is shown as perpendicular to the longitudinal side 28, i. e.,"directly toward"the longitudinal side. The elevation view of Fig. 3 shows the axis of discharge 68 also pointing at an angle toward the surface 12, i. e., downward, so that the axis 68 also intersects the surface 12. This configuration is referred to here as"directly toward and downward."This configuration provides controlled and efficient spraying of curbs 14.

In the example shown, the angle between the pavement surface 12 and the axis of discharge 68 is approximately 54 degrees. Other examples are contemplated. As one alternative, the spray nozzle can be pointed both forward and downward or also both rearward and downward such that the axis of discharge 68 intersects both the plane of the longitudinal side 28 and the plane of the surface 12.

The windshield 42 is shown as a horn having a first end 70 receiving the spray nozzle 40 and an opposite open end 72. The wind screen 42 is adapted to be proximate the curb 14. In the example shown, the wind screen 42 is an angular horn with a planar open end 72 that is generally perpendicular to the axis of discharge 68. In the example shown, the wind screen shield 42 is attached proximate the longitudinal side 28 and at least a portion of the open end 72 is above the height of the curb 14. In the example shown, the wind screen 42 is oriented to be directly toward and downward, but other configurations are possible, i. e., forward and downward or rearward and downward, or

the like. Also, the open end need not be planar, and the horn can be other than angular.

Alternatives include a formed open end with curved or angular sides to better mate with the curb 14.

An angled bracket 74 is used to connect the windshield 42 to the leading and trailing members 19,21 respectively, of the frame 18 so that the open end 72 of the windshield 42 can be proximate the curb 14. The angled bracket 74 is directly attached to the windshield 42 and to the leading and trailing members 19,21 via spacers 76.

The spacers 76 create additional height to the wind screen 42. If the angled bracket is removed, the wind screen 42 can be attached directly to the leading and trailing members 19,21 so the curb sprayer 10 becomes a pavement-only sprayer. In the example shown, the angled bracket 74 includes side members 78 attached to the wind screen 42 and base members 80 that attach to the frame 18. In the example shown, the side members 78 are angled upwardly from the base members 80 at approximately 26 degrees, although alternatives are contemplated. In another example, the bracket is configured so that this angle is adjustable.