GB2150861A - Variable length spray bar shield - Google Patents

Abstract

A variable length spray bar comprises a main spray bar (1) with a shield (2) and an auxiliary spray bar (3) with a shield. For the purpose of bridging the gap which would otherwise appear between the parts of the shield when the auxiliary spray bar (3) is projected outwardly from the main spray bar (1) there is provided a blind (10) which has one end attached to the auxiliary spray bar (3) and its other end coupled to a tensioning device, the blind being guided into a substantially horizontal plane by means of a roller (11). <IMAGE>

Description

SPECIFICATION Improvements relating to variable length spray bars This invention relates to variable length spray bars for spraying binder and other liquid material onto roads, footpaths and other surfaces.

A typical variable length spray bar currently in use and of the kind with which the invention is concerned comprises a main spray bar and an auxiliary spray bar which is parallel and directly adjacent either the front or the rear side of the main bar from which it can be projected to an adjustable extent depending upon the width of the surface which is to be sprayed. The main spray bar and the auxiliary spray bar each have a series of downwardly directed spray nozzles and a spray shield to prevent, so far as possible, the escape of the liquid and any attendant fumes, the shield of the auxiliary bar passes over the top of the shield on the main bar, but the position of the main bar prevents complete enclosure by the shield of the auxiliary bar when the latter is extended.In consequence when the auxiliary bar is extended a rectangular gap of width equivalent to the width of the main spray bar appears at the end of the latter and through the gap the aforesaid liquid and fumes can escape.

With the object of preventing this nuisance in a simple and effective manner it is proposed, in accordance with the present invention, that a variable length spray bar of the kind referred to above should be fitted with a spring-tensioned blind having its free end attached to the outward end of the auxiliary spray bar, and which is guided in a substantially horizontal plane to bridge the gap which appears between shields attached to the spray bars when the auxilliary spray bar is projected wholly or partly beyond the main spray bar.

One particular embodiment of the invention is illustrated in the accompanying drawings and is hereinafter described.

In these drawings: Figure 1 is a plan view of part of a typical variable length spray bar; Figure 2 is a plan perspective view of the spray bar showing the mode of mounting of the blind; and Figure 3 is a side elevation showing the position of the blind when the auxiliary spray bar is retracted.

Referring firstly to Figure 1, there is shown a main spray bar 1 with an associated shield 2 and an auxiliary spray bar 3 mounted beside the spray bar 1 and having its own associated shield 4 which overlaps the shield 2. The auxiliary spray bar 3 is shown in its fully projected position relative to the spray bar 1, as a result of which there has been created a rectangular aperture or gap G through which spray liquid or its fumes can pass.

Referring now to Figures 2 and 3, which illustrate the essence of the invention, there is shown a pedestal 5 mounted above the main spray bar and which carries at the top a jib 6 equipped with a pulley 7. Over the pulley there extends a wire 8 which enters a spring operated roller tensioning device 12 supported by the pedestal. The wire 8 is coupled by a snap hook 9 to one end of a ribbonlike blind 10 which passes behind a guide roller 11 and has its free end connected to the outward end of the auxiliary spray bar thereby bridging the gap G and preventing escape of spray liquid and its fumes. The right hand side of Figure 3 shows the auxiliary spray bar in its retracted position with substantially the whole of the blind 10 drawn into a vertical position by the action of the tensioning device 9.Figure 2 and the left side bottom part of Figure 3 show the auxiliary spray bar fully extended from the main spray bar with the blind 10 bridging the gap which would otherwise exsist from the end of the main spray bar.

Apart from the fact that the roller 11 touches the clean side of the blind it is to be noted that the blind is always held in an horizontal andlor vertical position and is never wrapped around itself. This is a necessary feature because the liquid being sprayed forms a coating on the under surface of the blind and if wrapped around itself the blind could stick as the coating hardens. This in turn could prevent the auxiliary spray bar from being extended or could cause damage to the blind itself.

1. A variable length spray bar comprising a main spray bar and an auxiliary spray bar mounted alongside it and projectable therefrom to an adjustable extend depending upon the width of the surface to be sprayed, characterised by a flexible blind connected at one end to a tensioning device and having its other end attached to the outward end of the auxiliary spray bar, the blind being guided in a substantially horizontal plane to bridge a gap which appears between shields attached to the auxiliary spray bar, when the auxiliary spray bar is projected from the main spray bar.

2. A variable length spray bar as claimed in Claim 1 including a spring operated tensioning device supported from a pedestal and having a wire which is connected to the other end of the flexible blind, the arrangement being such that when the blind is fully or partly retracted by the wire it is never wrapped around itself.

3. A variable length spray bar constructed and adapted to operate substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (3)

**WARNING** start of CLMS field may overlap end of DESC **. SPECIFICATION Improvements relating to variable length spray bars This invention relates to variable length spray bars for spraying binder and other liquid material onto roads, footpaths and other surfaces. A typical variable length spray bar currently in use and of the kind with which the invention is concerned comprises a main spray bar and an auxiliary spray bar which is parallel and directly adjacent either the front or the rear side of the main bar from which it can be projected to an adjustable extent depending upon the width of the surface which is to be sprayed. The main spray bar and the auxiliary spray bar each have a series of downwardly directed spray nozzles and a spray shield to prevent, so far as possible, the escape of the liquid and any attendant fumes, the shield of the auxiliary bar passes over the top of the shield on the main bar, but the position of the main bar prevents complete enclosure by the shield of the auxiliary bar when the latter is extended.In consequence when the auxiliary bar is extended a rectangular gap of width equivalent to the width of the main spray bar appears at the end of the latter and through the gap the aforesaid liquid and fumes can escape. With the object of preventing this nuisance in a simple and effective manner it is proposed, in accordance with the present invention, that a variable length spray bar of the kind referred to above should be fitted with a spring-tensioned blind having its free end attached to the outward end of the auxiliary spray bar, and which is guided in a substantially horizontal plane to bridge the gap which appears between shields attached to the spray bars when the auxilliary spray bar is projected wholly or partly beyond the main spray bar. One particular embodiment of the invention is illustrated in the accompanying drawings and is hereinafter described. In these drawings: Figure 1 is a plan view of part of a typical variable length spray bar; Figure 2 is a plan perspective view of the spray bar showing the mode of mounting of the blind; and Figure 3 is a side elevation showing the position of the blind when the auxiliary spray bar is retracted. Referring firstly to Figure 1, there is shown a main spray bar 1 with an associated shield 2 and an auxiliary spray bar 3 mounted beside the spray bar 1 and having its own associated shield 4 which overlaps the shield 2. The auxiliary spray bar 3 is shown in its fully projected position relative to the spray bar 1, as a result of which there has been created a rectangular aperture or gap G through which spray liquid or its fumes can pass. Referring now to Figures 2 and 3, which illustrate the essence of the invention, there is shown a pedestal 5 mounted above the main spray bar and which carries at the top a jib 6 equipped with a pulley 7. Over the pulley there extends a wire 8 which enters a spring operated roller tensioning device 12 supported by the pedestal. The wire 8 is coupled by a snap hook 9 to one end of a ribbonlike blind 10 which passes behind a guide roller 11 and has its free end connected to the outward end of the auxiliary spray bar thereby bridging the gap G and preventing escape of spray liquid and its fumes. The right hand side of Figure 3 shows the auxiliary spray bar in its retracted position with substantially the whole of the blind 10 drawn into a vertical position by the action of the tensioning device 9.Figure 2 and the left side bottom part of Figure 3 show the auxiliary spray bar fully extended from the main spray bar with the blind 10 bridging the gap which would otherwise exsist from the end of the main spray bar. Apart from the fact that the roller 11 touches the clean side of the blind it is to be noted that the blind is always held in an horizontal andlor vertical position and is never wrapped around itself. This is a necessary feature because the liquid being sprayed forms a coating on the under surface of the blind and if wrapped around itself the blind could stick as the coating hardens. This in turn could prevent the auxiliary spray bar from being extended or could cause damage to the blind itself. CLAIMS

1. A variable length spray bar comprising a main spray bar and an auxiliary spray bar mounted alongside it and projectable therefrom to an adjustable extend depending upon the width of the surface to be sprayed, characterised by a flexible blind connected at one end to a tensioning device and having its other end attached to the outward end of the auxiliary spray bar, the blind being guided in a substantially horizontal plane to bridge a gap which appears between shields attached to the auxiliary spray bar, when the auxiliary spray bar is projected from the main spray bar.

2. A variable length spray bar as claimed in Claim 1 including a spring operated tensioning device supported from a pedestal and having a wire which is connected to the other end of the flexible blind, the arrangement being such that when the blind is fully or partly retracted by the wire it is never wrapped around itself.

3. A variable length spray bar constructed and adapted to operate substantially as hereinbefore described with reference to, and as shown in, the accompanying drawings.