Patent Grant
9198269
The present disclosure relates to grounding means, and in particular, to a grounding apparatus, system and method for use in electrostatic coating processes and the like.
Electrostatic coating processes are well known in the art for providing efficient surface coatings. For instance, paint in the form of powdered particles or atomized liquid can be projected towards an object to be coated and accelerated toward this object via an electrostatic charge applied thereto. By keeping the surface of the object to be coated charge-neutral, for example via one or more grounding mechanisms, the charged paint particles can adhere to this surface via electrostatic bonding. The bonded paint/coating can then be dried/cured, for example via conveyance of the coated object from a painting enclosure to a drying/curing enclosure in a manufacturing process.
In general, electrostatic coating processes are applied to metallic surfaces; however, non-conductive objects can also be subject to electrostatic coating. For example, plastic trim components utilized in automobile manufacturing plants, or the like, are routinely coated via electrostatic coating, namely in some examples, via preprocessing of the surface(s) to be coated to render such surfaces conductive. These and other such techniques will be readily known and understood by the person of ordinary skill in the art.
While offering certain advantages over conventional coating processes, such as generally providing greater transfer efficiencies, electrostatic coating processes also provide certain challenges. For example, to avoid charge buildup on the coated object and/or surrounding articles, which can pose a significant workshop hazard and also reduce the efficiency and quality of the coating process, efficient grounding must be maintained during the coating process, both for the object/surface to be coated and surrounding equipment, such as object support racks and/or conveyor systems. To ensure satisfactory grounding, regular cleaning is required to reduce paint buildup, for example, and allow for equipment reuse (e.g. multiple production runs and/or multiple coatings for a same object). Accordingly, there is a constant need or desire to improve grounding techniques and equipment to increase or at least maintain grounding efficiency and resiliency while promoting reusability and/or a reduction in operator intervention, which can translate in significant productivity increases, particularly in the context of a manufacturing process and system.
Therefore, there remains a need for a grounding apparatus, system and method that overcome some of the drawbacks of known technologies, or at least, provides the public with a useful alternative.
This background information is provided to reveal information believed by the applicant to be of possible relevance to the present invention. No admission is necessarily intended, nor should be construed, that any of the preceding information constitutes prior art against the present invention.
An object of the invention is to provide a grounding apparatus, system and method that overcome some of the drawbacks of known technologies, or at least, provide the public with a useful alternative. In accordance with an embodiment of the invention, there is provided an apparatus for grounding an object to be coated via an electrostatic coating process, the object having a grounding conductor coupled thereto, the apparatus comprising: a grounding element; and a ground cover structurally coupled to said grounding element; said ground cover and said grounding element being moveable relative to one another between a receiving position for receiving the grounding element for conductive coupling between said grounding element and said cover, and a covering position for at least partially covering said conductive coupling.
In accordance with another embodiment of the invention, there is provided a system for grounding an object to be coated via an electrostatic coating process, the object having a grounding conductor coupled thereto, the system comprising: a grounded support for supporting the object during the electrostatic coating process; and a grounding apparatus as described above; wherein said grounding apparatus is conductively coupled to said grounded support.
In accordance with another embodiment of the invention, there is provided an apparatus for grounding an object to be coated via an electrostatic coating process, the object having a flexible grounding conductor coupled thereto, the apparatus comprising: a structure and a correspondingly sized cover structurally coupled together and moveable relative to one another between a receiving position for receiving the flexible grounding conductor between said structure and said cover, and a covered position in which said cover at least partially encases said structure such that the flexible conductor is at least partially wrapped around said structure within said cover, at least one of said structure and said cover providing a grounding surface such that the conductor is grounded via contact with said grounding surface when in the apparatus in said covered position.
In accordance with another embodiment of the invention, there is provided a method for grounding an object to be coated via electrostatic coating, using a grounding conductor, the method comprising the steps of: supporting the object on a grounded support; removably mounting a grounding apparatus on the support proximate a selected grounding location on the object; conductively coupling a first portion of the grounding conductor and the object at said selected grounding location; and conductively coupling a second portion of the grounding conductor and said grounding apparatus.
In accordance with another embodiment, the above method further comprises the step of at least partially covering said conductive coupling of said second portion and said grounding apparatus.
In accordance with another embodiment of the invention, there is provided a removable grounding apparatus for grounding an object to be coated via an electrostatic coating process, the object supported by a grounded support and having a first portion of a grounding conductor coupled to a selected location on the object, the apparatus comprising: a conductive clamping mechanism for coupling the apparatus to the support proximate the selected location; and a grounding mechanism for conductive coupling with a second portion of the conductor and for at least partially covering said conductive coupling with said second portion of the conductor.
Other aims, objects, advantages and features of the invention will become more apparent upon reading of the following non-restrictive description of specific embodiments thereof, given by way of example only with reference to the accompanying drawings.
Several embodiments of the present disclosure will be provided, by way of examples only, with reference to the appended drawings, wherein:
It should be understood that the disclosure is not limited in its application to the details of construction and the arrangement of components set forth in the following description or illustrated in the drawings. The disclosure is capable of other embodiments and of being practiced or of being carried out in various ways. Also, it is to be understood that the phraseology and terminology used herein is for the purpose of description and should not be regarded as limiting. The use of “including,” “comprising,” or “having” and variations thereof herein is meant to encompass the items listed thereafter and equivalents thereof as well as additional items. Unless limited otherwise, the terms “connected,” “coupled,” and “mounted,” and variations thereof herein are used broadly and encompass direct and indirect connections, couplings, and mountings. In addition, the terms “connected” and “coupled” and variations thereof are not restricted to physical or mechanical or electrical connections or couplings. Furthermore, and as described in subsequent paragraphs, the specific mechanical or electrical configurations illustrated in the drawings are intended to exemplify embodiments of the disclosure. However, other alternative mechanical or electrical configurations are possible which are considered to be within the teachings of the instant disclosure. Furthermore, unless otherwise indicated, the term “or” is to be considered inclusive.
With reference to the disclosure herein and the appended figures, a grounding apparatus, system and method will now be described, in accordance with different embodiments of the invention. In particular, various embodiments of a grounding apparatus, system and method are described herein for the grounding of an object to be coated by an electrostatic coating process, or the like.
In some embodiments, the grounding apparatus comprises a structure and a correspondingly sized cover coupled together and moveable relative to one another between a receiving position for receiving a grounding conductor therebetween, and a covered position in which the cover at least partially covers a conductive coupling between the conductor and the grounding apparatus. In such embodiments, at least one of the structure and cover provide a grounding surface such that the conductor is grounded via contact with this grounding surface when in the apparatus in the covered position. For example, either or both of the structure and cover may be manufactured of a conductive material, such as metal or steal, or again manufactured so to comprise a conductive surface or coating material, such that the grounding conductor may be conductively coupled to the grounding apparatus by maintaining contact with this material. For instance, the structure may comprise a grounded or groundable structure, otherwise and interchangeably described herein as a grounding element, and/or the cover may comprise a grounded or groundable cover, whereby conductive coupling of the grounding conductor between the cover and structure in the covered position allows for effective grounding of the object to which the grounding conductor is coupled.
As will be discussed in greater detail below, during operation, the grounding apparatus will also be grounded, either directly or via a support provided to both support the object and ground same via the provided grounding apparatus. In the latter case, the grounding apparatus may either be fixedly coupled and/or integral to the support, or removably coupled thereto, for example via one or more clamping mechanisms or the like, as will be described in greater detail below.
For example, in one embodiment, one or more removable grounding apparatus may be provided to be conductively mounted to a grounded support at a location thereon proximate to a grounding location on the object to be coated. Namely, where the object is positioned on the support and where a grounding conductor is coupled to a selected location on the object to be coated, the removable grounding apparatus may be positioned on and conductively coupled to the grounded support proximate this selected location so to facilitate conductive coupling of the object to the grounding apparatus via this grounding conductor. These and other examples will be further discussed below with reference to different embodiments of the invention, some of which depicted in the accompanying figures.
With reference to
In this particular embodiment, each grounding mechanism 104 is configured to allow conductive coupling of a grounding conductor, for example a flexible conductor such as foil tape 108 or the like (otherwise known as a ground strap), operatively coupled to the object to be coated, and the grounded support 102. As will be appreciated by the skilled artisan, the object may be coated via various electrostatic coating processes, which may include piece-by-piece coatings, for example by an operator working on a single object at a time, or in a chain manufacturing environment where successive objects are conveyed through an electrostatic coating chamber to be coated automatically. In any respect, to provide a safe work environment, the person of ordinary skill in the art will appreciate that the various components supporting the object, or otherwise provided in the context of a manufacturing process, should also be adequately grounded. Accordingly, while the support 102 is shown generally in
With added reference to
In this illustrative embodiment, the grounding element 110 generally consists of an elongate member such as a steel or metal bar/cylinder fixedly coupled to the clamping mechanism 106 so to provide and maintain a conductive coupling therewith, which conductive coupling thus effectively grounding the grounding element 110 upon conductive clamping of the apparatus 104 to a grounded support, such as support 102, via clamping mechanism 106. Examples of appropriate couplings may include, but are not limited to, welding, pressure fitted couplings, integrally molded or cast components and the like, as will be readily appreciated by the skilled artisan.
Again within the context of this illustrative embodiment, the ground cover 112 is generally structurally coupled to the grounding element 110, for example via pivot peg or bar 114, to pivot relative thereto and thus move between the conductor receiving position and covering position. In particular, the cover 112 generally consists of an elongate sleeve or cover shaped and sized to correspond and cooperate (e.g. for mating engagement) with the shape and size of the grounding element 110 so to at least partially encase the grounding element 110 in the covering position. In this embodiment, the cover is also manufactured of a conductive material such as metal or steel and is conductively coupled to the grounding element via pivot pin 114, whereby a conductor received and at least partially covered between the grounding element 110 and cover 112 is effectively grounded through all surface contacts with the grounding apparatus 104. The cover further comprises a handle, depicted herein as an L-shaped projection 116 to facilitate movement of the cover 112 to the conductor receiving position, which may be controllably returned to the covering position via this handle, or again moved under gravity upon releasing the cover 112.
Still in the context of this illustrative embodiment, the grounding apparatus 104 further comprises clamping mechanism 106, which generally consists of a fitted U-shaped structure 118 shaped and sized to fittingly engage a portion of the support 102, and a securing mechanism, such as bolt 120 extending through corresponding bores 122 provided at respective distal ends 124 of the U-shaped structure 118 and positioned so to secure the U-shaped structure 118 on the support 102. For example, bolt 120 may be fastened through bores 122 so to compress the distal ends 124 of the U-shaped structure 118 toward one another and against the support 102, thereby securing the clamping mechanism 106 thereto. Other securing mechanisms will be readily apparent to the person of ordinary skill in the art, as will other clamping mechanisms in general, without departing from the general scope and nature of the present disclosure. For example, while a specific example of a clamping mechanism is described herein, it will be appreciated that the term “clamping mechanism” is broadly used herein to encompass different mechanisms for clamping or otherwise removably and conductively securing the grounding mechanism to a given support.
Referring now to
In this illustrative embodiment, the ground cover 212 generally consists of an elongate box or case manufactured of a conductive material such as steel or metal and fixedly coupled to the structure 202 to permanently provide and maintain a conductive coupling therewith, which conductive coupling thus effectively grounding the cover 212 and components conductively coupled therewith when the support 202 is effectively grounded.
In this embodiment, the structure 210 is generally structurally coupled to the cover 212, for example via pivot peg or bar 214 installed at an extremity thereof, to pivot relative thereto and thus move between the conductor receiving position and covering position. In this particular embodiment, the structure 210 generally consists of an elongate cylindrical member 230 welded or otherwise fixedly coupled to a substantially flat bar 232, whereby the cylindrical member 220 is shaped and sized to correspond with the shape and size of the cover 212 for mating engagement therewith in the covering position, thus at least partially covering or encasing a grounding conductor received therebetween. In this embodiment the structure 210 is also manufactured of a conductive material such as metal or steel and is conductively coupled to the grounded cover 212 via pivot pin 214 to further enhance grounding of a grounding conductor received therebetween in the covering position. As best shown in
Referring now to
In this illustrative embodiment, the element 310 generally consists of an elongate bar or member manufactured of a conductive material such as steel or metal and fixedly coupled to the structure 302 to permanently provide and maintain a conductive coupling therewith, which conductive coupling thus effectively grounding the element 310 and components conductively coupled therewith when the support 302 is effectively grounded. It will be appreciated that while a substantially cylindrical grounding element 310 is shown, other shapes and sizes may be readily considered herein without departing from the general scope and nature of the present disclosure.
In this embodiment, the cover 312 is generally structurally coupled to the element 310, for example via pivot peg or bar 314 installed at an extremity thereof, to pivot relative thereto and thus move between the conductor receiving position and covering position. In this particular embodiment, the cover 312 generally consists of an elongate box whereby the cylindrical grounding element 310 is shaped and sized to correspond with the shape and size of this box for mating engagement therewith in the covering position, thus at least partially covering or encasing a grounding conductor received therebetween. In this embodiment the cover is also manufactured of a conductive material such as metal or steel and is conductively coupled to the grounded structure 310 via pivot pin 314 to further enhance grounding of a grounding conductor received therebetween in the covering position. As best shown in
As will be appreciated by the skilled artisan, while the above embodiments describe a combination of a conductive structure and cover in forming an effective grounding connection with an associated grounding conductor, other material combinations may be considered herein to provide a similar effect. Namely, a non-conductive structure or element could be used to urge a grounding conductor against the interior of a conductive and grounded cover, just as a non-conductive cover could be used to urge such grounding conductor against and/or around a conductive and grounded structure or element. The person of ordinary skill in the art will note however that in order to ensure grounding of all exposed materials, the provision of a conductive cover and grounding element may provide some advantages over non-conductive combinations.
Furthermore, the skilled artisan will appreciate the potential advantages of a removable grounding apparatus, as described above in relation to
As will also be appreciated by the skilled artisan, the provision of a cover that is structurally coupled to the grounding element or structure may provide various advantages over similar designs where the cover is fully removable. For example, one fully removable implementation may involve the positioning of a grounding conductor over a protrusion, such as a bolt or the like, extending outwardly from a grounded support, which bolt and conductor may then be covered by a rubber grommet or plug to both secure and cover the grounding connection. In such an example, however, there may be increased risk of the cover being dislodged or falling, or again of the installation of such a cover on a flexible grounding conductor such as a foil tape or the like resulting in a sheering or tearing of the grounding conductor. Accordingly, lesser groundings may ensue as can risks of injury increase from tripping or slipping on a heavily coated and dislodged grommet, for example. Accordingly, the provision of a structurally coupled cover, as described above in accordance with some embodiments of the invention, reduces the likelihood of such covers being dislodged, lost or otherwise removed before, during or after processing, and thus promotes greater grounding consistency, effectiveness, and safety.
As will be readily appreciated by the skilled artisan, the above described embodiments and their equivalents can provide various additional or alternative advantages and benefits. For example, some embodiments may provide for a reduction in paint or coating buildup on the grounding connection, and/or provide for an increased stability of the grounding connection. By improving the ground effectiveness and reliability, associated advantages may include, but are not limited to, an improved coating consistency, appearance, and/or a reduction in drips, thins, sags and/or colour shifts; a reduction in overspray and/or greater control on coating material delivery, which may result in a reduction in paint use, VOCs and/or in the use of chemicals to assist in overspray control; and other such advantages as will be readily apparent to the skilled artisan.
It will also be appreciated that some embodiments may be readily manufactured from few parts to comprise few moving parts, thus making the manufacture of such embodiments readily achievable at low cost while remaining easy to use and sufficiently robust to withstand various implementation environments.
Furthermore, in some embodiments, for example those including a cylindrical grounding element engaging a correspondingly shaped and sized cover, the conductive coupling between the grounding conductor and grounding apparatus may be achieved without, of with reduced likelihood of forming a pinch point. It will be appreciated that different structure and cover shapes and sizes may lend themselves to different advantages, either in promoting enhanced ground couplings, for example where a grounding conductor is effectively wrapped, smoothed or urged between the structure and corresponding cover, or again in promoting greater ease of use and/or user operation, to name a few.
These and other advantages of the above described and other related embodiments will be readily apparent to the person of ordinary skill in the art, as will alternative apparatus shapes, sizes, structures, materials, manufactures and component couplings, which alternatives are thus considered to fall within the general scope and nature of the present disclosure.
While the present disclosure describes various exemplary embodiments, the disclosure is not so limited. To the contrary, the disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
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