WO2007034244A1

WO2007034244A1 - Surface cleaning apparatus

Info

Publication number: WO2007034244A1
Application number: PCT/GB2006/050301
Authority: WO
Inventors: Charles Jonathan Kennett; Sheila Hamilton
Original assignee: Teknek Holdings Limited
Priority date: 2005-09-21
Filing date: 2006-09-21
Publication date: 2007-03-29
Also published as: GB0519263D0

Abstract

The invention relates to surface cleaning apparatus of the type used to clean surfaces of a travelling work piece. The apparatus comprises cleaning units (comprising cleaning and adhesive rollers 10, 12) which are mounted on a supporting framework (14) for pivotable movement about a pivot axis such that the rollers (10, 12) are pivotable into an orientation wherein their direction of rotation coincides with the direction of travel of the work piece (18) to be cleaned. The pivoting movement can be passive (i.e. influenced only by the direction of travel of the work piece 18) or active (i.e. by means of a piston arrangement (32) which oscillates the supporting framework (14) laterally with respect to the width of the work piece (18) to be cleaned. The apparatus prevents localised accumulation of debris on the rollers (10, 12), particularly when cleaning trimmed edges of a work piece (18).

Description

Surface Cleaning Apparatus

This invention relates to surface cleaning apparatus, and particularly, but not exclusively, to surface cleaning apparatus employing a cleaning roller and an adhesive roller for removing contamination and/or debris from a surface to be cleaned.

Surface cleaning apparatus employing cleaning and adhesive rollers is known. Such apparatus operates by providing the cleaning roller with a surface of relatively low tackiness that contacts an adhesive roller of relatively high tackiness, the respective rollers being arranged parallel to one another and contacting each other over substantially their entire length. As a web or sheet material (hereinafter referred to as a work piece) is conveyed over the surface of the cleaning roller, debris on the work piece is removed. In order that the cleaning roller remains effective over a period of time, the removed debris is transferred to, and retained by, the adhesive roller during rotation of the respective rollers. Commonly, the work piece to be cleaned is conveyed through the nip of at least two opposed rollers, at least one of which is a cleaning roller. If pairs of cleaning rollers are used, particulate material can be simultaneously removed from the opposing surfaces of the work piece.

An important factor in improving production line efficiency is the minimising of downtime. A feature of surface cleaning apparatus of the type described above is that periodic removal of the cleaning and adhesive rollers is necessary. For example, the adhesive rollers need to be removed in order to remove saturated exterior layers and expose fresh areas of adhesive. A particular problem arises when there is localised heavy saturation of the adhesive roller around its circumference. Such problems are particularly prevalent when cleaning the trimmed edge or edges of a work piece. In doing so, the excess particulate material along the edges of the work piece tends to accumulate in a linear fashion around the circumference of the adhesive roller. The resulting non-uniform distribution of particulate material along the adhesive roller's width reduces its overall cleaning efficiency and necessitates its premature replacement. The accumulation of particulate material arises because: (i) both the cleaning and adhesive rollers extend beyond the lateral edge or edges of the work piece; and (ii) each lateral edge continuously and repetitiously contacts the cleaning roller along the same line of contact which is then transferred to the adhesive roller.

According to a first aspect of the present invention there is provided surface cleaning apparatus for cleaning a surface of a travelling work piece, the apparatus comprising a cleaning roller having an axis of rotation and a supporting framework, the cleaning roller being supportable on the framework and pivotable about a pivot axis into an orientation wherein a radial component of the cleaning roller aligns with the direction of travel of a work piece to be cleaned

Preferably, the pivot axis is substantially normal to the surface of the work piece to be cleaned.

Optionally, the pivoting motion is passive such that the orientation of the roller is influenced only by the direction of travel of the work piece to be cleaned. Preferably, the apparatus is further provided with means for oscillating the supporting framework in a direction which is perpendicular to the direction of travel of the work piece to be cleaned such that the lateral position of the cleaning roller with respect to the work piece can be continuously varied; and wherein the pivoting motion is influenced both by the direction of travel of the work piece to be cleaned and by said oscillating movement.

Preferably, the rate of oscillation is controllable by varying the stroke length and/or stroke speed of the oscillation means.

Preferably, the oscillation means is a piston.

Preferably, the apparatus further comprises a fixed framework, the supporting framework being moveable thereon to effect its oscillation.

Optionally, the apparatus further comprises lockable means for selectively preventing pivoting of the cleaning roller by locking it in position relative to the supporting frame.

Preferably, at least one pair of opposed cleaning rollers are pivotably supportable on said supporting framework, said rollers being orientated to clean opposite surfaces of a work piece to be cleaned.

Preferably, at least one of each pair of cleaning rollers is moveable between a first non-operating position in which it is spaced from the work piece to be cleaned and a second operating position in which it contacts the work piece to be cleaned.

Preferably, the apparatus further comprises an adhesive roller which is co- operable with each cleaning roller. According to a second aspect of the present invention there is provided a surface cleaning system comprising surface cleaning apparatus according to the first aspect, the system being adapted such that the apparatus is used in conjunction with one or more additional cleaning rollers positioned downstream with respect to the direction of travel of the work piece to be cleaned.

Embodiments of the invention will now be described, by way of example only, with reference to the following drawings, in which:

Fig. 1 is a perspective schematic view of a work piece to be cleaned and illustrating the tendency for contamination to accumulate in a non-linear fashion on the adhesive roller;

Figs. 2a-c show a side, front and plan view respectively of a cleaning unit;

Fig. 3 shows a side view of a pair of cleaning units having their cleaning rollers adapted to clean opposite surfaces of a work piece, the cleaning units being in a fully retracted state where the respective rollers are spaced from each other and spaced from the work piece;

Fig. 4 shows a side view of a pair of cleaning units having their cleaning rollers adapted to clean opposite surfaces of a work piece, the cleaning units being in an intermediate state where the respective rollers are spaced from each other and the cleaning rollers are in contact with the work piece;

Fig. 5 shows a side view of a pair of cleaning units having their cleaning rollers adapted to clean opposite surfaces of a work piece, the cleaning units being in a fully engaged state where the respective rollers are in contact with each other and the cleaning rollers are in contact with the work piece;

Figs. 6a and 6b show front and side views respectively of two pairs of cleaning units supported by a supporting framework in an intermediate state as shown in Fig. 4, the apparatus being positioned at the extremity of its oscillation to the left;

Figs. 7a and 7b show front and side views respectively of a two pairs of cleaning units supported by a supporting framework in an intermediate state as shown in Fig. 4, the apparatus being positioned at the extremity of its oscillation to the right; and

Figs. 8a-e show perspective, rear, cross-sectional, front and plan views respectively of cantilevered cleaning units for cleaning narrow work pieces.

Fig. 1 illustrates the problem inherent in known surface cleaning apparatus whereby the trimmed edges of a work piece 18 result in the localised accumulation of excess particulate material. The localised excess particulate material is transferred from the work piece 18 to the adhesive roller 12 (via the cleaning roller 10) and tends to accumulate in a linear fashion around the circumference of the adhesive roller 12. The resulting non-uniform distribution of particulate material along the adhesive roller's width reduces its overall cleaning efficiency and necessitates its premature replacement.

Figs. 2a-c show three views of a roller assembly according to the present invention comprising a cleaning roller 10 and an adhesive roller 12 each roller being rotatably mounted via its axis of rotation in bearings of the roller assembly. Although the respective rollers are shown in a spaced non-operating arrangement, it will be appreciated that the adhesive roller 12 may be moved into contact with the cleaning roller by means of a piston arrangement 13 shown in Fig 2c.

The cleaning and adhesive rollers 10, 12 are connected to a supporting frame 14 (shown in Figs. 6-8) at a pivot point 16 and the cleaning roller 10 contacts a work piece 18 (shown most clearly in Figs. 4 and 5). The pivot axis is perpendicular to the plane of the work piece 18 and its function is described in detail below.

The cleaning and adhesive rollers 10, 12 are co-operable with each other and can be arranged in pairs proximate the opposing surfaces of a work piece 18 to be cleaned. Three sequential configurations are possible as outlined in Figs. 3-5.

In Fig. 3, the respective rollers 10, 12 (which define a cleaning unit) are spaced from each other and the cleaning roller 10 is spaced from the work piece 18 to be cleaned. The cleaning unit is therefore in a fully retracted state which: (i) prevents 'wetting' of the cleaning roller 10 by the adhesive roller 12 when the apparatus is inoperative; and (ii) facilitates the initial feeding of the work piece 18 between the cleaning rollers 10. A tilting mechanism 34 (described further below in relation to Fig. 8a) may be used to increase the spacing of the upper cleaning unit from the lower cleaning unit.

In Fig. 4, the respective rollers 10, 12 remain spaced from each other as shown in Fig. 3 but the opposing cleaning rollers are in contact with the work piece 18 to be cleaned. The cleaning units are therefore in an intermediate state.

The fully engaged state of the cleaning units is shown in Fig. 5 whereby the respective rollers 10, 12 are brought into contact with each other whilst maintaining the cleaning rollers 10 in contact with the work piece 18. The cleaning units shown in Fig. 5 are therefore ready for operation.

Figs. 6a and 6b show surface cleaning apparatus according to the present invention comprising two pairs of cleaning rollers 10 contacting opposing surfaces of the work piece 18 to be cleaned at positions corresponding to the opposite lateral edges of the work piece 18. The cleaning units are shown in their intermediate state (as shown in Fig. 4) before the adhesive rollers 12 are moved into contact with the cleaning rollers 10. The work piece 18 travels out of the plane of the paper in Fig. 6a. Each cleaning unit is mounted on the supporting framework 14 which is itself mounted on a fixed framework 24. An upper portion of the fixed framework 24 defines a track upon which the supporting framework 14 is slidably moveable. In Fig. 6a it can be seen that the supporting framework 14 is at the full extent of its oscillation to the left on the fixed framework 24 with the result that only a small portion of the cleaning rollers 10 are in contact with the surface of the work piece 18 proximate its left lateral edge whilst, at the right lateral edge, the cleaning rollers 10 are in contact with the work piece 18 over substantially their entire width.

Figs. 7a and 7b are similar to Figs. 6a and 6b, however, the supporting framework 14 is at the full extent of its oscillation to the right on the fixed framework 24. In this position, the cleaning rollers 10 are in contact with the work piece 18 proximate its left lateral edge over substantially their entire width whilst, at its right lateral edge, only a small portion of the cleaning rollers 10 are in contact with the surface of the work piece 18.

The lateral spacing of the cleaning units shown in Figs. 6a and 7a on the supporting framework 14 is adapted to be less than the width of the work piece 18. Therefore, only a small portion of the width of the left cleaning rollers 10 are in contact with the surface of the work piece 18 proximate its left lateral edge whilst the right cleaning rollers 10 are in contact with the work piece 18 over substantially their entire width and vice versa.

Fig. 8a shows a single pair of cleaning units mounted on a supporting framework 14 which is itself mounted on a fixed framework 24. It should be noted that only a portion of the frameworks 14, 24 are shown for clarity. Each cleaning unit comprises a fixed portion 26a which is fixed to the supporting framework 14, and a pivotable portion 26b in which the rollers 10, 12 are mounted within their bearings. The pivotable portion is pivotable relative to the fixed portion 26a about a pivot connection 28, the axis of which is perpendicular to the rotational axis of the rollers 10, 12 and perpendicular to the plane of the work piece to be cleaned (not shown). A locking mechanism is provided on each cleaning unit which selectively locks the fixed portion 26a in position relative to the pivotable portion 26b.

Fig. 8d shows a piston 32 in communication with the supporting framework 14 such that the reciprocal motion of the piston 32 is transferred to the supporting framework 14.

The work piece is conveyed substantially tangentially through the nip of the cleaning rollers 10. A tilting mechanism 34 is provided on the upper part of the supporting framework 14. In use, the tilting mechanism 34 referred to above is used to retract the upper cleaning unit to allow a work piece 18 to be 'threaded' between the cleaning rollers 10. When in position, the work piece 18 will be under tension and its lower surface will rest on the lower cleaning roller 10 which is fixed in position thus providing a reference point. The tilting mechanism 34 is then used to lower the upper cleaning unit until the upper cleaning roller 10 contacts the upper surface of the work piece 18. The work piece 18 is thus positioned between the nip of the two cleaning rollers 10 and is set in motion such that it is conveyed substantially tangentially with respect to the rollers 10.

Upon actuation of the apparatus, the piston 32 moves in a reciprocal motion. The stroke speed and stroke length of the oscillating motion is variable and controllable by pneumatic means. In one non-limiting example, the stroke speed is 0.5mm per second and the stroke length is 50mm. Such motion is communicated to the supporting framework 14 which slides back and forth along the fixed framework 24. The fixed portions 26a of the cleaning units are fixed relative to, and oscillate with, the supporting framework 14.

Assuming that the locking mechanisms of the pivot connections are deactivated, the inertial resistance of the pivotable portions 26b of the cleaning units means that the cleaning rollers 10 will not immediately follow the oscillating motion of the fixed portions 26a such that a radial component of the rollers (i.e. that which is perpendicular to the axes of rotation of the rollers) will be out of alignment with the direction of travel of the work piece 18. However, the movement of the work piece 18 and its frictional engagement with the cleaning rollers 10 influences the cleaning rollers 10 which continually attempt to align a radial component of the rollers with the direction of movement of the work piece 18. The effect of the inertial resistance of the pivotable portions 26b is that there is a time lag between the movement of the fixed portions and the corresponding lateral movement of the cleaning rollers 10 over the work piece 18.

The continuous nature of the oscillating movement of the supporting framework 14 means that a radial component of the cleaning rollers 10 and the direction of travel of the work piece 18 are only momentarily in perfect alignment during each oscillation. Accordingly, there is effectively a continual effort on behalf of the cleaning rollers 10 to achieve such alignment which ensures that the cleaning rollers 10 continually move laterally along the work piece 18. This continuous lateral movement of the cleaning rollers 10 ensures that the collection of debris by the cleaning roller is spread more evenly over its width. More importantly, debris which is transferred to each adhesive roller 12 is distributed more evenly across its entire width. It will be appreciated that the passive nature of the pivotable connection allows free movement of the cleaning rollers and prevents them from applying any excessive shear loads to the work piece 18 which would influence its tracking by 'steering' it in a new direction.

Whilst the foregoing describes a preferred arrangement of the present invention, in its simplest form, the oscillating motion of the supporting frame could be dispensed with. In doing so, the pivotable portion 26b of each cleaning unit would pivot only in response to any misalignment or incorrect tracking of the work piece 18. Whilst this arrangement would not facilitate a more even distribution of debris over the width of the rollers 10, 12 it would serve to minimise wear of the cleaning rollers 10 and/or the work piece 18 due to their inadvertent misalignment. By activating the locking mechanism, the pivoting of the pivotable portions 26b relative to the fixed portions 26a is prevented. This may be implemented in situations where it is desired to influence the tracking or alignment of the work piece by 'steering' it in a new direction (i.e. perhaps to correct any minor misalignment of the work piece without the need for separate tracking correction apparatus).

It will be appreciated that the rollers 10, 12 may be provided in varying widths to accommodate differing requirements. For example, in circumstances where two pairs of cleaning units according to the present invention are employed to clean the respective lateral edges of a relatively wide work piece (i.e. where other cleaning units are employed to clean its central portion) then a typical roller width might be approximately 100mm.

Such lateral cleaning units will be positioned up stream of the central cleaning units in order to protect the central cleaning units from the worst of the edge contamination. It is to be understood that the phrase 'central cleaning unit' includes conventional cleaning units whose cleaning roller's span the entire width of a work piece. Alternatively, the central cleaning units may not extend to all the way to the lateral edges of the work piece.

However, it will be appreciated that for narrower work pieces, a single pair of cleaning units will be sufficient to clean both lateral edges. A single pair of cleaning rollers 10 could be supported on a modified supporting framework 14 in a cantilevered fashion as illustrated by Figs. 8a-e. For a 7 inch (177.8mm) web, a typical roller width might be 230mm and for a 10 inch (254.0mm) web, a typical roller width might be 305mm. It will be appreciated that these roller widths are indicative only and any suitable roller width can be used depending upon specific requirements. Modifications and improvements can be made without departing from the scope of the present invention. For example, although in the foregoing description the supporting framework slides along a track on the fixed framework, it could equally move on any other suitable means such as wheels or an airbed.

Also, whilst a piston arrangement is used to effect the oscillating movement of the supporting framework on the fixed framework, a similar effect could be achieved by using a suitable cam arrangement.

Whilst the invention has been described with reference to pairs of rollers arranged to contact opposing sides of a work piece, it will be appreciated that only one of the rollers need be a cleaning roller, the opposing roller being a guide roller.

Finally, although the invention has primarily been described with reference to the cleaning of lateral edges of a work piece, it will be appreciated that the cleaning units may be positioned at any desired point along the supporting framework (i.e. between the lateral edges of the work piece) to correspond with localised contamination.

Claims

1. Surface cleaning apparatus for cleaning a surface of a travelling work piece, the apparatus comprising a cleaning roller having an axis of rotation and a supporting framework, the cleaning roller being supportable on the framework and pivotable about a pivot axis into an orientation wherein a radial component of the cleaning roller aligns with the direction of travel of a work piece to be cleaned.

2. Surface cleaning apparatus as claimed in claim 1 , wherein the pivot axis is substantially normal to the surface of the work piece to be cleaned.

3. Surface cleaning apparatus as claimed in claim 1 or 2, wherein the pivoting motion is passive such that the orientation of the roller is influenced only by the direction of travel of the work piece to be cleaned.

4. Surface cleaning apparatus as claimed in any preceding claim, wherein the apparatus is further provided with means for oscillating the supporting framework in a direction which is perpendicular to the direction of travel of the work piece to be cleaned such that the lateral position of the cleaning roller with respect to the work piece can be continuously varied; and wherein the pivoting motion is influenced both by the direction of travel of the work piece to be cleaned and by said oscillating movement.

5. Surface cleaning apparatus as claimed in claim 4, wherein the rate of oscillation is controllable by varying the stroke length and/or stroke speed of the oscillation means.

6. Surface cleaning apparatus as claimed in claim 4 or 5, wherein the oscillation means is a piston.

7. Surface cleaning apparatus as claimed in any of claims 4 to 6, wherein the apparatus further comprises a fixed framework, the supporting framework being moveable thereon to effect its oscillation.

8. Surface cleaning apparatus as claimed in any preceding claim, wherein the apparatus further comprises lockable means for selectively preventing pivoting of the cleaning roller by locking it in position relative to the supporting frame.

9. Surface cleaning apparatus as claimed in any preceding claim, wherein at least one pair of opposed cleaning rollers are pivotably supportable on said supporting framework, said rollers being orientated to clean opposite surfaces of a work piece to be cleaned.

10. Surface cleaning apparatus as claimed in claim 9, wherein at least one of each pair of cleaning rollers is moveable between a first non- operating position in which it is spaced from the work piece to be cleaned and a second operating position in which it contacts the work piece to be cleaned.

11. Surface cleaning apparatus as claimed in any preceding claim, wherein the apparatus further comprises an adhesive roller which is co- operable with each cleaning roller.

12. A surface cleaning system comprising surface cleaning apparatus according to any one of claims 1 to 11 , the system being adapted such that the apparatus is used in conjunction with one or more additional cleaning rollers positioned downstream with respect to the direction of travel of the work piece to be cleaned.

13. Surface cleaning apparatus as substantially hereinbefore described with reference to Figs. 2 to 8 of the accompanying drawings.