Apparatus and process for wrapping and securing edge flaps of flexible cover sheet to panel structure
A process for wrapping an edge flap of a workpiece having a covering sheet extending over a front face thereof and edge flaps protruding outwardly beyond the front face. The workpiece is positioned on a table, with one edge and the protruding flap overhanging and protruding outwardly beyond the table. The workpiece is disposed in proper location by positioning elements and clamps fix it to the table. adhesive is applied to the edge flap. A wrapping arrangement is provided with wiping blades so that upward movement of the wiping arrangement causes a first wiping blade to engage the edge flap and wipe it upwardly into engagement with an edge face, following which the wiping arrangement moves the second blade over the workpiece so that a second wiping blade engages the end part of the flap and wipes it downwardly into engagement with the back face of the workpiece.
1. A process for wrapping an edge of a panel-shaped substrate, comprising the steps of:
providing a workpiece defined by a panel-shaped substrate having first and second pairs of generally parallel edge faces which extend generally perpendicular to one another, and a thin flexible cover sheet positioned in overlying relationship to a front face of said substrate and having a flexible edge flap associated with each of said edge faces and extending along and protruding outwardly beyond the respective edge face;
providing a support defining an upwardly-facing top surface adapted for supporting said workpiece thereon;
positioning said workpiece on said support so that the flexible cover sheet thereof faces downwardly and is disposed in overlying relationship to said top surface;
locating said workpiece on the support in cooperating engagement with a positioning arrangement associated with the support so that said workpiece along a first one if the edge faces extending lenthwise thereof horizontally overhangs a respective adjacent first edge of the top surface and a first one of the edge flaps protrudes generally horizontally outwardly from said first one of the edge faces;
clamping said workpiece fixedly on the support in a position determined by the positioning arrangement;
applying adhesive to an upwardly-facing back side of said first one of the edge flaps throughout a length thereof;
providing an edge flap wrapping arrangement positioned adjacent said first edge of said top support and including first and second stiff but resilient wiping blades which extend lengthwise along said first edge, said first wiping blade projecting generally horizontally toward said first edge and terminating at a tip end, and said second wiping blade projecting generally vertically downwardly and terminating at a lower tip end;
moving said edge flap wrapping arrangement upwardly adjacent said first edge of said top surface so that said first wiping blade contacts and deflects said first one of the edge flaps upwardly and the tip end of said first wiping blade wipes upwardly of the first one of the edge flaps and presses the first one of the edge flaps into contact with the first one of the edge faces of the workpiece;
continuing upward movement of said first wiping blade until the first wiping blade moves upwardly out of engagement with the first one of the edge flaps;
then moving the second wiping blade generally horizontally inwardly so that the second wiping blade contacts an upwardly protruding upper edge part of the first one of the edge flaps and deflects the first one of the edge flaps downwardly over an upwardly-facing back face of said workpiece and the lower tip end presses the edge part of the first one of the edge flaps into contact with the back face;
then returning the edge flap wrapping arrangement back to a retracted position spaced from said workpiece.
2. A process according to claim 1 , including the steps of:
providing a roller unit having roller surfaces positioned for lengthwise rolling engagement with both the first one of the edge faces and the back face of said workpiece; and
after the edge flap wrapping arrangement has been moved to the retracted position, engaging said roller unit with said first one of the edge faces and the back face of said workpiece, and rollingly moving the roller unit lengthwise along the first one of the edge faces and the back face of said workpiece to effect pressing of the first one of the edge flaps against the first one of the edge faces and the back face.
3. A process according to claim 1 , including the steps of:
providing a workpiece positioning structure movable between a raised retracted position relative to the support and a lowered active position wherein the positioning arrangement is disposed sidewardly adjacent and spaced outwardly a small horizontal distance from the first edge of the top surface to permit said workpiece to be abutted thereagainst so that the first one of the edge faces thereof horizontally overhangs the first edge of the top surface, said workpiece positioning structure when in said lowered active position being at an elevation at least slightly above the top surface of the support so that the first one of the edge flaps projects outwardly below the positioning arrangement; and
moving said workpiece positioning structure into said raised retracted position after said workpiece has been clamped to said support.
4. A process according to claim 3 , including the steps of:
providing a roller unit having roller surfaces positioned for lengthwise rolling engagement with both the first one of the edge faces and the back face of said workpiece; and
after the edge flap wrapping arrangement has been moved to the retracted position, engaging said roller unit with said first one of the edge faces and the back face of said workpiece, and rollingly moving the roller unit lengthwise along the first one of the edge faces and the back face of said workpiece to effect pressing of the first one of the edge flaps against the first one of the edge faces and the back face.
5. A process according to claim 3 , including the steps of:
providing the positioning arrangement with first and second positioning elements which, in said lowered active position, are disposed adjacent and outwardly from respective first and second perpendicular edges of the support so that edge faces of said workpiece that are perpendicular overhang the perpendicular of the support when said workpiece is engaged with the first and second positioning elements;
applying adhesive to a back side of a second one of the edge flaps associated with the second perpendicular edge of the support; and
providing a second wrapping arrangement positioned adjacent and extending along the second perpendicular edge of the support and including first and second wiping blades corresponding to the first and second wiping blades associated with said edge flap wrapping arrangement; and
after said edge flap wrapping arrangement retracts from said workpiece, moving said second wrapping arrangement upwardly adjacent said second perpendicular edge of the support so that the first wiping blade thereof deflects and presses the second one of the edge flaps associated with the second perpendicular edge into contact with second one of the edge faces, and then moving the second wiping blade horizontally inwardly to deflect and wipe an edge part of the second one of the edge flaps associated with the second perpendicular edge downwardly into engagement with the back face of said workpiece.
6. A process according to claim 5 , including the steps of:
following completion of the edge wrapping of the first and second edge flaps on said workpiece as defined above, then releasing said workpiece from the support, rotating said workpiece horizontally 180 degrees relative to the support, then repositioning said workpiece in engagement with the positioning elements and clamping said workpiece to the support, and then applying adhesive to the back surfaces of remaining ones of the flaps and then wrapping remaining ones of the edges of said workpiece following the same process steps defined above.