GB2159438A - Support frame - Google Patents

Abstract

A support frame for supporting an article during electrostatic powder spray coating comprises a border (10) having along two opposite sides (12a, 12b) thereof, a pair of aligned abutments (17-21), the pairs of abutments (17-21), in use, receiving a support element (22) with which an article (26) to be supported is engaged, and the border (10) having means (14) to engage the frame with a conveyor. <IMAGE>

Description

SPECIFICATION Support frame This invention relates to a support frame for supporting an article, and more particularly but not exclusively, to a support frame for supporting an article during a powder coating process in which an electric current is passed through an article to be coated, whilst the article is subjected to a spray or mist of powder whereby the powder is attracted to the article. Thereafter, the article and coating is usually baked in an oven to fix the powder.

At present, support frames are provided which are relatively expensive to produce and which, in the case of a powder coating process, require frequent cleaning, so as to permit good electrical contact between the frame and the article to be coated. Such frames comprise a wire mesh which may have a border, the frame having a plurality of hooks provided by cutting the mesh and bending the wire into hook formations, or alternatively welding or brazing hooks to the mesh frame. The articles to be supported each have a receiving formation, such as an aperture, and are hung on the hooks of the frame, electrical continuity being obtained by virtue of the direct contact between the hanging articles and the frame.

A support frame on which an article is hung is engaged with a conveyor which conveys the frame and may provide electrical current thereto. A loaded frame can be heavy but in any case known frames once loaded are difficult to handle and engage with the conveyor.

It is an object of the present invention to provide a new or improved support frame which overcomes or reduces these problems.

According to one aspect of this invention, we provide a support frame for supporting an article comprising a border having along two opposite sides thereof, a pair of aligned abutments, the pair of abutments, in use, receiving a support element with which the article to be supported is engaged, and the border having means to engage the frame with a conveyor.

Thus a support frame in accordance with the invention may be made more economically than known support frames because there is no need to provide hooks by cutting and bending the wire of a mesh, which is a labour intensive operation, but the article to be supported can be simply threaded onto the support element, or otherwise directly engaged therewith.

Further, the article may be hung on the support element before the support element is received by the pair of abutments of the border, so that the border can be engaged with the conveyor prior to the support element being received thereby to facilitate loading of the support frame.

Preferably, at least said two opposite sides of the border comprise lengths of wire, and the abutments are provided by bends in the wire, for example loops formed in the wire. Particularly where the support frame is, in use, disposed generally upright so that the axes of the support elements lie in a vertical or upwardly inclined plane, the loops or other abutments may each have an upper part on which the support element is in use received, which slopes towards an adjacent part of the side of the border, so as to retain the support element in position during handling of the loaded frame.

The border is preferably of generally rectangular configuration, said two opposite sides extending parallel or nearly parallel to one another, and the border having upper and lower cross bars which are integral with or connected, by welding or brazing for examples, to said opposite sides.

Alternatively, the frame could be of other configurations. For example, said two opposite sides need not extend parallel to one another provided that the abutments of the pair of apertures are aligned with one another.

It will be appreciated that such a support frame is very easily and inexpensively made. Thus, particularly in a powder coating application, rather than having to clean the frame frequently to ensure electrical continuity, which is a time consuming and expensive operation, the frame can simply be discarded when no longer serviceable. Further, should only the support element become unserviceable, e.g. coated with powder to such an extent that an article can no longer be received thereon, and/or electrical continuity maintained, the support element can be discarded and the border retained.

Preferably, a plurality of pairs of abutments are provided by said two opposite sides so that a plurality of support elements, each having an article or articles engaged therewith, can be received by the border, to enable a plurality of articles to be supported.

It will be appreciated that the points of contact between the support element or elements and the abutments will be shielded during a powder coating process sq that when the support element or elements is/are subsequently removed to permit articles to be disengaged from the support element or elements, there will be a clean area on the abutments and on the support elements, so that during subsequent processes, electrical continuity can again be achieved without having to clean the abutments and/or the support elements.Of course, the points of contact between the articles and the support elements will also be shielded during the powder coating process, and thus provided that fresh articles to be supported are located in similar positions along the support elements to the articles coated in a previous process, electrical continuity will again be attained between the articles and the support element or elements.

Particularly in a powder coating process, the means to engage the conveyor preferably comprises a hook at the upper end of each of the opposite sides of the border, the hooks engaging an electrical conductor of the conveyor which carries electrical current, so that the current is conducted through the frame to the articles to be powder coated.

The support elements may comprise, preferably straight, wires, which are engaged with the abutments of the border at or adjacent their ends, al though the support element or elements could be bent if required, to provide separating members between two or more articles supported on the support elements, or otherwise provided with separating members.

The surface of the support element, or at least one of the support elements, may have a plurality of formations spaced along its length to resist movement of an article supported on the support element longitudinally thereof. This is particularly important during conveying where otherwise articles to be powder coated, for example, could be easily dislodged.

The formations preferably extend at least partially around the surface of the support element in a plane generally transverse to the longitudinal axis of the support element.

The formations may be provided by deforming the surface of the support element, for example, using one or more rollers which impress said surface formations.

According to a second aspect of the invention, we provide a support element for use in a support frame according to the first aspect of the invention, the surface of the support element or at least one of the support elements having a plurality of formations spaced along its length, to resist movement of an article supported on the support element longitudinally thereof.

According to a third aspect of the invention, we provide a method of powder coating utilising a frame according to the first aspect of the invention, said method including the steps of engaging an article to be coated on a support element, receiving the support element by said abutments of the border, engaging the frame with a conveyor, passing an electrical current through said support frame and hence through the article which is supported, subjecting the article to a spray or mist of powder.

The invention will now be described with the aid of the accompanying drawings in which: Figure 1 is a perspective view, partly exploded, of a support frame in accordance with the invention, with articles supported on the frame; Figure 2 is an enlarged view of part of the support frame of Figure 1.

Referring to the drawings, there is shown a support frame 10 comprising a border 11 of generally rectangular configuration, having two opposite sides 12a and 12b, an upper cross bar 13a and a lower cross bar 13b. Each of the sides 12a and 12b, and the bars 13a, 13b are made of thin wire and are spot welded together, as shown at W at each corner of the frame. Of course, if desired, the border may be made with one or more of the cross bars 13a, 13b integral with one or more of the opposite sides 12a, 12h, although the present arrangement is preferred as the upper end of each of the sides 12a and 12b which project beyond the upper cross bar 13a, can be bent as shown to provide a hook 14 to engage with a conveyor, shown at 15 in dotted lines, which is moved in the direction of arrow A.

The conveyor 15 comprises an electrical conductor and conducts electrical current to the frame 10 by virtue of the direct contact between the hooks 14 and the conveyor 15.

Each of the opposite sides 12a and 12b have pairs of aligned loops 17, 18, 19, 20, 21, formed therein, providing abutments, each pair of abutments receiving a support element 22.

The loops 17 to 21 each have an upper surface 23 indicated clearly on abutments 18 where the corresponding support element 22 is shown removed, for clarity. The surface 23 slopes downwardly towards an adjacent straight part 24 of the respective sides 12a or 12b so that the ends of support elements 23 are received at the lowest points 25 of the surfaces 23, as shown, to prevent the elements 22 being dislodged during handling of the frame 10.

In the example shown, five pairs of abutments are provided, and hence five support elements 22 are provided. Of course, in another example, more or less than five support elements 22 may be provided, received by a corresponding number of pairs of abutments.

Further, in the example shown, the frame 10 is, in use, disposed generally upright, with each of the longitudinal axes of the five support elements 22 lying in a generally vertical plane, although in another embodiment, the frame 10 may, in use, not extend vertically but could extend, for example, with the plane in which the axes of the support elements 22 lie, being generally inclined to the horizontal and vertical.

Each of the support elements 22 may have articles 26 engaged therewith, although, for clarity, articles 26 are only shown engaged with one of the support elements 22, i.e. that received by abutments 20. As shown, each of the articles 26 have an opening 27 and are threaded onto the support elements 22 before the support elements 22 are received by their corresponding abutments by the sides 12a, 12b.

in use, with the frame 10 fully loaded, the conveyor 15 conveys the frame 10, and hence the articles 26, to a powder coating station where powder is coated onto the articles 26 due to the attraction of the powder caused by the electrical current flowing through the articles 26. Thereafter, the conveyor 15 conveyes the frame 10 and the thus coated articles 26 to an oven where heat is applied to bake and harden the coating.

It will be appreciated that during the entire process, electrical continuity between the conductor of the conveyor 15 and the articles 26 will be provided first by the direct engagement of the hooks 14 with the conveyor 15, then by the direct engagement of each of the support elements 22 with their respective abutments provided by the loops 17 to 21, and due to the direct engagement between the articles 26 and the support elements 22 on which the articles 26 are threaded.

At the end of a powder coating process, the support elements 22 are removed from the border 11, which may require some force as powder may have set around the points of contact between the support elements 22 and the sides 12a and 2b, and the articles are disengaged from the support ele ments 20.

However, the points of contact between the sides 12a, 12b, and the support elements 22, and between the support elements 22 and the articles 26 will be shielded from being coated with powder by virtue of their contact. Hence, once the articles 26 are removed from the support elements 22, and the support elements 22 from the abutments, fresh articles to be coated may be threaded onto the support elements 22 and the support elements received by the frame, and electrical continuity will again be ensured between the previously directly contacting points of contact, so that the frame 10 can be re-used.

After a plurality of cycles of use, the build-up of powder on the frame 10 may be such as to prevent articles 26 being received on their support elements 22, or the support elements 22 being received by the abutments provided by the loops 17 to 21, and electric continuity maintained.

The frame 10 could be cleaned, by immersing in acid for example, but because the frame 10 is so easily and inexpensively made, the frame 10 can be discarded and a new frame used.

Of course, the individual support elements 22 can be replaced individually at any time as soon as they become unserviceable.

Further, as shown, three articles 26 only are received on each support element 22, but in another embodiment, more or less articles may be received on each support element 22.

Of course, instead of providing abutments 17 to 21 by bending the sides 12a and 12b to provide the loops, pairs of aligned abutments could otherwise be provided. For example, abutments may be welded onto the sides 12a, 12b although this would obviously increase the cost of production.

As shown, the support elements 22 comprise straight wires, although could in another arrangement have bends to provide separating members to separate articles engaged thereon or separating members could otherwise be provided if required.

Preferably however, the surface of each of the support elements 22 is impressed, as shown in Figure 2, with a plurality of formations 30 spaced along the length of the support elements 22. For example, the formations could be provided by passing the elements 22 between a pair of rollers or passing a single roller over the elements.

As shown, each of the formations 30 extend around the circumference of the generally cylindrical support element wire 22 in a direction so as to be in a plane transverse to the longitudinal axis L of the support element 22. The formations 30 resist articles engaged with the support element, moving longitudinally of the support element as can occur as the frame 10 is conveyed, and during engagement of the article laden support elements with the border.

As shown, the formations 30 extend throughout the length of the support elements but may extend over only part of the length if required, and the formations 30 may be provided by any desired alternative method to that described.

Referring again to Figure 1, part of a further sim ilar frame 10' is shown secured to the support frame 10, hooks 14' of the frame 10' engaging over the lower cross bar 13b of frame 10. To permit of this, the frame 10 is slightly wider at the bottom than at the top to permit the hooks 14' to be received between the sides 12a, 12b of frame 10. Of course, any number of such frames 10, 10' could be engaged with conveyor 15 and with each other provided that conveyor 15 and frames 10, 10' are sufficiently strong.

Although as described, the support frame 10 has been used in a powder coating process, a support frame in accordance with the invention may be used in many other applications where it is required to support articles for spraying or other processing.

The features disclosed in the foregoing description, or in the following claims, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, as appropriate, may, separately or any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims (15)

1. A support frame for supporting an article comprising a border having along two opposite sides thereof, a pair of aligned abutments, the pair of abutments, in use, receiving a support element with which the article to be supported is engaged, and the border having means to engage the frame with a conveyor.

2. A frame according to Claim 1 wherein at least said two opposite sides of the border comprise lengths of wire, the abutments being provided by bends in the wire.

3. A frame according to Claim 2 wherein the bends comprise loops formed in the wire.

4. A frame according to Claim 2 or Claim 3 wherein the abutments each have an upper part on which the support element is in use received, which slopes towards an adjacent part of the side of the border, so as to retain the support element in position during handling of the loaded frame.

5. A frame according to any one of the preceding claims wherein the border is of generally rectangular configuration, said two opposite sides extending parallel or nearly parallel to one another, and the border having upper and lower cross bars which are integral with or connected to said opposite sides.

6. A frame according to any one of the preceding claims wherein a plurality of pairs of abutments are provided by said two opposite sides so that a plurality of support elements, each having an article or articles engaged therewith, can be received by the border, to enable a plurality of articles to be supported.

7. A frame according to any one of the preceding claims wherein the means to engage the conveyor comprises a hook at the upper end of each of the opposite sides of the border, the hooks engaging an electrical conductor of the conveyor which carries electrical current, so that the current is conducted through the frame to the articles.

8. A frame according to any one of the preceding claims wherein the support elements comprise wires, which are engaged with the abutments of the border at or adjacent their ends.

9. A frame according to any one of the preceding claims wherein the surface of the support element, or at least one of the support elements, has a plurality of formations spaced along its length to resist movement of an article supported on the support elements longitudinally thereof.

10. A frame according to Claim 9 wherein the formations extend at least partially around the surface of the support element in a plane generally transverse to the longitudinal axis of the support element.

11. A frame according to Claim 9 or Claim 10 wherein said formations are provided by deforming the surface of the support element, using one or more rollers which impress said surface formations.

12. A support frame substantially as hereinbefore described with reference to and as shown in the accompanying drawings.

13. A support element for use in a support frame according to any one of the preceding claims, the surface of the support element or at least one of the support elements having a plurality of formations spaced along its length, to resist movement of an article supported on the support element longitudinally thereof.

14. A method of powder coating utilising a frame according to any one of Claims 1 to 12, said method including the steps of engaging an article to be supported with a support element, receiving the support element by said abutments of the border, engaging the frame with a conveyor, passing an electrical current through said support frame and hence through the article which is supported, subjecting the article to a spray or mist of powder.

15. Any novel feature or novel combination of features disclosed herein and/or shown in the accompanying drawings.