GB2550607A

GB2550607A - Spraying a liquid

Info

Publication number: GB2550607A
Application number: GB1609210.8A
Authority: GB
Inventors: Phillip Ingram Daniel; West John
Original assignee: S T L Trading Co Ltd
Current assignee: S T L Trading Co Ltd
Priority date: 2016-05-25
Filing date: 2016-05-25
Publication date: 2017-11-29
Also published as: GB201609210D0

Abstract

An apparatus for spraying a liquid comprising: a metal canister 301 containing the liquid pressurised propellant: a manually operable valve; and electrical insulation 201 applied to outer surface of the metal canister. Preferably, insulation is transparent plastic or elastomeric pre-formed moulding, with a lubricant or adhesive between the insulation and canister. Preferably, valve is covered by insulating cap, which is rotatable to expose or obscure the valve. A method of constructing a spraying apparatus comprising: forming a pressurised canister with a vale; and deploying electrical insulation over the canister. Preferably, insulation has side wall, an open end and a closed end, and the canister slides in 302 and down to the bottom. A method of applying paint with an insulated canister. Preferably, indications are visible through the translucent/transparent elastomer.

Description

Spraying a Liquid CROSS REFERENCE TO RELATED APPLICATIONS This application represents the first application for a patent directed towards the invention and the subject matter. BACKGROUND OF THE INVENTION The present invention relates to an apparatus for spraying a liquid, a method of constructing an apparatus for spraying a liquid, and a method of applying marking paint in an environment having an energised electric conductor.

It is known to provide apparatus for spraying a liquid in which the liquid is retained within a metal canister. Metal canisters are useful for this application because they are capable of withstanding relatively high pressures, such that a single unit can provide a substantial volume of output material at a required operating pressure. Attempts have been made to use other materials and, in particular, electrically insulating materials. However, materials of this type are either highly specialised, and therefore expensive, or are incapable of withstanding the required operating pressures. BRIEF SUMMARY OF THE INVENTION According to an aspect of the present invention, there is provided an apparatus for spraying a liquid, comprising; a metal canister for retaining said liquid; a pressurised propellant for expelling said liquid from said canister; a manually operable valve for manually controlling the expelling of liquid from said canister; and electrical insulation means applied to an outer surface of said metal canister.

In an embodiment, the electrical insulating means comprises a rubber end and may be in the form of a pre-formed moulding.

According to a second aspect of the present invention, there is provided a method of constructing an apparatus for spraying a liquid. comprising the steps of: forming a metal canister with said liquid retained therein, along with a pressurised propellant for expelling said liquid from said canister in response to manual operation of a valve; and deploying electrical insulation means over an outer surface of said metal canister.

In an embodiment, an insulating top-cover is applied over said valve.

According to a third aspect of the present invention, there is provided a method of applying marking paint in an environment having an energised electric conductor, comprising the steps of: removing a pressurised canister of marking paint from a canister supporting means; activating a manually operable valve to release paint onto a designated area; and returning said canister to said canister supporting means, wherein: an electrical insulating means has been applied over an outer surface of said metal canister, such that said canister is rendered electrically non-conductive and will not conduct electricity if brought into contact with said electrical conductor.

In an embodiment, a further step is performed of checking indications printed on said canister, prior to activating said manually operable valve, that are visible through the electrical insulating means.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

Figure 1 illustrates a metal canister;

Figure 2 shows the formation of a rubber moulding;

Figure 3 shows the insertion of the moulding of Figure 2 over the canister of Figure 1;

Figure 4 shows the attachment of an insulating top-cover;

Figure 5 shows the removal of a canister from a supporting bag;

Figure 6 illustrates the possibility of a canister falling and bridging a gap between onto energised railway lines;

Figure 7 illustrates the transparent nature of an insulating cover;

Figure 8 illustrates the movement of a top-cover;

Figure 9 shows access to a valve; and

Figure 10 illustrates activation of the valve identified in Figure 9.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 A metal canister 101 is shown in Figure 1, that has an outer surface 102. The metal canister 101 has been formed with a iiquid 103 retained therein. In addition, there is provided a pressurised propeilant 104 for expelling liquid 103 from the canister in response to manual operation of a valve 105.

In an embodiment, the liquid is paint and in a particuiar embodiment, the paint is of the type used for semi-permanent marking on construction and surveying sites. In an embodiment, as described with respect to Figure 6, the marking paint may be used for marking designated areas of railway infrastructure. In this environment, one or more energised electrical conductors may be present and dangerous situations may arise if the metallic conducting canister came into direct contact with electrical conductors of this type.

In accordance with an aspect of the present invention, eleckrical insulation means has been deployed over the outer surface 102 of the metal canister. In this way, if the canister is dropped, it is not possible for it to provide an electricai short-circuit and thereby create a hazardous situation.

Figure 2

In an embodiment of the invention, the electrical insulation means is deployed by forming a rubber moulding 201, having an open-end 202, a side wall 203 and a closed-end 204.

In an embodiment, moulding 201 is produced by a process of injection moulding, in which liquid rubber is fed into a heated barrel, mixed and then forced into a mould cavity. In the mould cavity, the material cools and hardens to the configuration of the cavity. The mould is then released, to yield the moulding identified in Figure 2.

In an alternative embodiment, it is possible for the moulding of Figure 2 to be produced by a process of extrusion moulding. When produced in this way, the vertical cylindrical portion defining wall 203 is produced by an extrusion process, in a manner substantially similar to that of producing a pipe. The pipe is then cut into sections and bottom portions 204 are then attached, possibly by a welding process. A resulting moulding is placed in the orientation as illustrated in Figure 2. Thereafter, a lubricant, from lubricant container 205, is introduced into the moulding. Alternatively, it is possible for the lubricant to be applied to external surface 102 of the canister.

Figure 3

After forming the rubber moulding 201, with an open-end 202, a closed-end 301 of a canister 101 is inserted into the open end 202 of the moulding. The canister 101 is then slid into the moulding 201 in the direction of arrow 302. In an embodiment, the sliding operation is performed until an outer surface of said closed-end of said canister engages with a bottom inside surface of the moulding.

Figure 4

Having slid the moulding fully over the outer surface of the metal canister, to produce an insulated assembly 401, an insulating top-cover 202 is applied over the valve.

Thus, in this way, it is possible to produce an embodiment of an apparatus for spraying a liquid, such as marking paint. The assembly comprises a metal canister for retaining the liquid, along with a pressurised propellant for expelling the liquid from the canister. A manually operable valve is present, for manually controlling the expelling of liquid from the canister, and an electrical insulation, in the form of the moulding, has been applied to the outer surface of the metal canister.

In this embodiment, the electrical insulation is a rubber and in a particular embodiment, the rubber is a pre-formed moulding. As previously described, it is possible to deploy a lubricant between the outer surface of the canister and an internal surface of the moulding, so as to assist with the operation of combining the two as described with reference to Figure 3. In addition, or as an alternative, it is also possible to deploy an adhesive between the pre-formed moulding and the outer surface of the metal canister such that, after deployment, it is difficult to remove the insulating moulding; thereby ensuring that all assemblies in service retain their insulating characteristics.

To assist with the operation described with respect to Figure 3, the pre-formed moulding may be a rubber. Furthermore, it is preferable for the rubber to be transparent or at least translucent, such that it is possible for printed designations on the canister to be viewed through the translucent material. In this example, the words “line marker” continue to be viewable after the deployment of the insulating means.

In an embodiment, the manually operable valve is restrained within a valve cup, as is known in the art, potentially rendering part of the assembly still conductive, after the deployment of the main insulating means. Consequently, in the embodiment of Figure 4, the manually operable cover is contained within an electrically insulating top-cover.

In the embodiment of Figure 4, the top-cover includes a fixed element attached to a rim formed on the metal canister. In addition, there is provided a rotatable element covering a portion of the fixed element and rotatable around the fixed element, as shown in Figure 8. Thus, in this way, it is possible for the rotatable element to be rotatable between a first position, in which the manually operable valve is obscured, and a second position in which access is facilitated to said manually operable valve.

Figure 5

The apparatus previously described facilitates a method of applying marking paint in an environment having an energised electric conductor. Often, a canister or a plurality of canisters, along with other equipment, are restrained within a canister supporting means, such as a bag 501. To use the apparatus, the pressurised canister 401 is removed from the bag 501.

Figure 6 A problem with removing a pressurised canister from the bag 501 is that it is possible for a can to slip, possibly if it is pulled out of the bag using a cap, and said cap has not been properly restrained upon the canister. Furthermore, it is also possible that when removing a first canister, a further canister is also removed from the bag which may in turn fall between a mechanically supportive earth rail 601 and an electrically conducting centre rail 602 of a railway line. As is known in the art, railway lines of this type are deployed in direct current systems where the total length of the line is relatively modest. However, it should be appreciated that other hazardous environments of this type exist, where it is possible that a non-lnsulated can could introduce a dangerous conducting element Into the environment.

Figure 7

As previously described with respect to Figure 4, in an embodiment, the insulating means is transparent or at least translucent, such that it is possible for printed indications to be checked, as illustrated in Figure 7, prior to activating the manually operable valve. Thus, in this way, it is possible for different canisters with insulating covers, to be retained within bag 501, given that it is relatively easy to make an appropriate selection and check by viewing the printed material through the insulation. Thus, in this way, substantially conventional canisters may be deployed with the insulation being retro-fitted.

Figure 8

As previously descried, the assembly is provided with an electrically insulating top-cover 402, to allow manual access to the valve.

In an embodiment, the insulating top-cover 502 includes a fixed element 801 attached to a rim 802 of the metal canister. In addition, there is provided a rotatable element 803 covering a portion of the fixed element 801. Thus, in this embodiment, the top-cover is operated by rotating the rotatable element to expose the manually operable valve. In the embodiment shown in Figure 8, the fixed element 801 includes a cut-out 804 defining the shape of an arrow and thereby indicating the direction in which the rotatable element 803 should be rotated.

Figure 9

Having rotated rotatable element 803, it is possible to apply manual pressure in the direction of arrow 901 upon a portion 902 of the manual operable valve.

Figure 10

In this embodiment, when deployed, pressure is applied in the direction of arrow 901, thereby creating a spray 1001 of marking paint onto a designated area 1002.

Claims

CLAIMS The invention claimed is:

1. An apparatus for spraying a liquid, comprising; a metal canister for retaining said liquid; a pressurised propellant for expelling said liquid from said canister; a manually operable valve for manually controlling the expelling of liquid from said canister; and electrical insulation means applied to an outer surface of said metal canister.

2. The apparatus of claim 1, wherein said electrical insulation means comprises a plastic.

3. The apparatus of claim 2, wherein said plastic is a pre-formed plastic moulding.

4. The apparatus of claim 3, wherein a lubricant is included between said pre-formed plastic moulding and said outer surface of said metal canister.

5. The apparatus of claim 3, wherein an adhesive is included between said pre-formed plastic moulding and said outer surface of said metal canister.

6. The apparatus of claim 3, wherein said pre-formed plastic moulding is an elastomer.

7. The apparatus of any of claims 3 to 6, wherein said pre-formed plastic moulding is transparent/translucent.

8. The apparatus of any of claims 1 to 7, wherein said manually operable valve is contained within an electrically insulating top-cover.

9. The apparatus of claim 8, wherein said electrically insulating top-cover includes: a fixed element attached to a rim formed on said metal canister; and a rotatable element covering a portion of said fixed element and rotatable around said fixed element.

10. The apparatus of cteiim 9, wherein said rotatable element is rotatable between: a first position, in which said manually operable valve is obscured; and a second position, in which access is facilitated to said manually operation valve.

11. A method of constructing an apparatus for spraying a liquid, comprising the step of: forming a metal canister with said liquid retained therein, along with a pressurised propellant for expelling said liquid from said canister in response to manual operation of a valve; and deploying electrical insulation means over an outer surface of said metal canister.

12. The method of claim 11, wherein said deploying step includes the steps of: forming an elastomer-plastic moulding, having an open-end, a side-wall and a closed-end; and inserting a closed-end of said canister into said open-end of said moulding; and sliding the canister into the moulding.

13. The method of claim 12, wherein said sliding operation is performed until an outer surface of said closed-end of said engages with a bottom inside surface of the moulding.

14. The method of claim 12 or claim 13, wherein a lubricant is introduced to the canister and/or the moulding prior to said inserting step.

15. The method of any of claims 11 to 14, further comprising the step of applying an insulating top-cover over said valve.

16. A method of applying marking paint in an environment having an energised electric conductor, comprising the steps of: removing a pressurised canister of marking paint from a canister supporting means; activating a manually operable valve to release paint onto a designated area; and returning said canister to said canister supporting means, wherein: an electrical insulating means has been applied over an outer surface of said metal canister, such that said canister is rendered electrically non-conductive and will not conduct electricity if brought into contact with said electrical conductor.

17. The method of claim 16, further comprising the step of checking indications printed on said canister prior to activating said manually operable valve that are visible through said electrical insulating means.

18. The method of claim 17, wherein said electrical insulating means is a translucent/transparent elastomer.

19. The method of any of claims 16 to 18, further comprising the step of operating an electrically insulating top-cover to allow manual access to said valve.

20. The method of claim 20, wherein: said insulating top-cover includes a fixed element attached to a rim of said metal canister and a rotatable element covering a portion of said fixed element: and said step of operating said electrically insulating top-cover includes the step of rotating said rotatable element to expose said manually operable valve.