EP0828584A1

EP0828584A1 - Abrasive sheet array and dispenser

Info

Publication number: EP0828584A1
Application number: EP96916693A
Authority: EP
Inventors: William B. King; Darrell R. Degeus; Richard Francis
Original assignee: Minnesota Mining and Manufacturing Co
Current assignee: 3M Co
Priority date: 1995-05-30
Filing date: 1996-05-29
Publication date: 1998-03-18
Also published as: WO1996038264A1; GB9510865D0; CA2220028A1

Abstract

Abrasive sheet arrays comprising a plurality of abrasive sheets joined together and readily detachable from each other. The array is cut from abrasive sheet material and may be cut simultaneously with one or more other arrays. One particular array is generally hexagonal in shape and comprises six generally triangular sheets which are joined together at isolated locations so that they may easily be detached from each other. Also disclosed is a dispenser for storing an array and for dispensing abrasive sheets from the array.

Description

ABRASIVE SHEET ARRAY AND DISPENSER

TECHNICAL FIELD The present invention relates generally to abrasive sheets, methods of producing such sheets, and a dispenser for such sheets, and more particularly to arrays of abrasive sheets, methods of producing such arrays of sheets, and a dispenser for dispensing individual sheets from such an array.

BACKGROUND OF THE INVENTION

Abrasive sheets are available in many shapes and sizes, depending on the use for which they are intended. Some abrasive sheets are intended specifically for use with powered tools, for example rotary or orbital tools and, in that case, the shape of a sheet is determined by the particular tool with which it is to be used. Abrasive sheets in a range of standard shapes and sizes, suited to most standard powered tools, are readily available and are produced by die cutting continuous abrasive sheet material. Because large quantities of the standard shaped sheets are required, the die cutting operation can be carried out on a continuous basis using a rotary die cutter, and the subsequent handling and packing of the shaped sheets can be automated.

Disc-shaped sheets, for example, are very commonly used for powered tools, and it is known to use a rotary die cutter to cut a plurality of individual discs or, alternatively, to cut chains of connected discs which can be wound onto a roll or folded up and packaged. See, for example, U.S. Patent No. 4,893,438. It is also known to provide dispensers for chains of connected abrasive articles and for non- connected abrasive articles provided on a continuous backing. See, for example, U.S. Patent Nos. 3,267,623 (Block); 3,849,949 (Steinhauser et al.); and 4,294,357 (Stevens et al.). Additionally, U.S. Patent No. 5,183,479 (Grimes) discloses a method for manufacturing heavy duty grinding discs by stamping a plurality of interconnected disc shapes. The shapes are notched or weakened for separation. The interconnected shapes are then covered with abrasive embedded in adhesive. While Grimes is primarily concerned with methods of making circular discs, it also discloses that that abrasives may be hexagonal, octagonal, or any form for which coated abrasive on a backing is required. U.S. Patent No. 5,197,998 (Germain) discloses an aligned row of connected abrasive sheets, each sheet having a main portion, an aperture formed in the main portion, and a plurality of arm portions perimetrically spaced about the main portion. The arm portion of each abrasive sheet are angularly offset with respect to the arm portions of each immediately adjacent sheet by one-half of the angle between each of the arm portions.

At times, however, a limited quantity of sheets of a particular, non-standard, shape and size may be required and that may not justify investment in a rotary die. Moreover, automated handling and packing of the sheets may be difficult or impractical. In that case, the manufacturer might use a flat-bed die cutter, which is less costly, to cut the shaped sheets which might then be collated and packed by hand. As a result, the production of limited quantities of such non-standard abrasive sheets will be comparatively slow and expensive.

A problem with which the present invention is concerned is that of enabling limited quantities of abrasive sheets, especially in non-standard shapes or sizes, to be produced more quickly and less expensively than at present. A further problem with which the invention is concerned is that of enabling limited quantities of non-standard abrasive sheets to be packaged and handled more easily than at present.

SUMMARY OF THE INVENTION

One aspect of the present invention provides an abrasive sheet array. The array comprises a plurality of abrasive sheets joined together and readily detachable from each other. Each of the abrasive sheets is generally triangular and includes a narrow end and a wide end opposite the narrow end, and the array is generally polygonal.

In one preferred arrangement of the above inventive array, the abrasive sheets are joined together by the material from which the sheets are formed. In another preferred arrangement of the above array each abrasive sheet comprises a substrate material having a first side and a second side, the substrate having abrasive material on the first side and means for releasably attaching the abrasive sheet to a drive member on the second side. In another preferred arrangement of the above array, the abrasive sheets are joined to each other at discrete locations on the edges of the sheets.

In another preferred arrangement of the above inventive array the array comprises a plurality of abrasive sheets arranged so as to have the narrow end of each sheet adjacent the narrow end of each adjacent abrasive sheet and so as to have the wide end of each sheet adjacent to the wide end of each adjacent sheet. In one preferred aspect of this arrangement, the array comprises four abrasive sheets forming a generally square array. In another preferred aspect of this arrangement, the array comprising five abrasive sheets forming a generally pentagonal array. In still another preferred embodiment of this arrangement, the array comprises six abrasive sheets forming a generally hexagonal array.

In another preferred arrangement of the above inventive array, the array comprises a plurality of abrasive sheets arranged so as to have the narrow end of each abrasive sheet adjacent the wide end of each adjacent abrasive sheet. In one preferred embodiment, the array is spirally wound so as to form a roll of abrasive sheets. In anther preferred embodiment of this arrangement, the array has a first end and a second end opposite the first end, a longitudinal axis extending in the direction from the first end to the second end and a transverse axis perpendicular to the longitudinal axis, each abrasive sheet has at least one line of symmetry, and each abrasive sheet is arranged so as to have its line of symmetry parallel to the transverse axis of the array. In another preferred embodiment of this arrangement, adjacent first and second abrasive sheets are joined along a first line forming a first angle relative to the transverse axis of the array, and a third abrasive sheet is joined to the second abrasive sheet along a second line opposite the first line, the second line forming a second angle relative to the transverse axis of the array. In still another preferred embodiment of this arrangement the first and second angles are of substantially equally magnitude and are of opposite orientation relative to the transverse axis of the array. Another aspect of the present invention provides a dispenser for storing an array of abrasive sheets and for separating abrasive sheets from the array. The dispenser comprises: a box configured to store the array of sheets, the box including a first wall having an opening therein for dispensing the array from inside the box to outside the box, the opening bounded by first and second opening edges; and abrasive sheet separating means mounted on the first wall, the separating means comprising a first separator edge oriented at a first edge angle relative to the first wall and a second separator edge oriented at a second edge angle relative to the first wall.

In one preferred embodiment of the above inventive dispenser, the separator means comprises: a first abrasive sheet separator mounted on the first wall proximate the first edge of the opening, the first separator including the first separator edge; and a second abrasive sheet separator mounted on the first wall proximate the second edge of the opening, the second separator including the second separator edge.

In another preferred embodiment of the above dispenser, the first edge angle and the second edge angle are of substantially the same magnitude and of opposite orientation relative to the first wall of the dispenser. In a more preferred embodiment, the first edge angle is substantially equal to +30° relative to the first wall and the second edge angle is substantially equal to -30° relative to the second wall.

A further aspect of the present invention provides a separator for separating individual abrasive sheets from an array of abrasive sheets. The separator is for use with an array including a plurality of abrasive sheets arranged along the longitudinal axis of the array, with the individual sheets each joined on a first side to a first respective adjacent sheet generally along a first line at a first angle relative to the transverse axis of the array and joined on a second side to a second respective adjacent sheet generally along a second line at a second angle relative to the transverse axis of the array. The inventive separator comprises: separator means configured to receive the array in a direction along the first axis of the separator means, the separator means having a second axis perpendicular to the first axis and lying in the plane defined by the abrasive sheets as they pass through the separator means; the separator means including a first separator edge oriented at a first edge angle relative to the second axis and a second separator edge oriented at a second edge angle relative to the second axis.

In one preferred embodiment, the separator means comprises: a first abrasive sheet separator including the first separator edge; and a second abrasive sheet separator including the second separator edge. The first and second separators are provided opposite to one another and are configured to receive the array between the first and second separators.

In another preferred embodiment of the above inventive separator the first edge angle and the second edge angle are of substantially the same magnitude and of opposite orientation relative to the second axis. In a more preferred embodiment, the first edge angle is substantially equal to +30° relative to the second axis and the second edge angle is substantially equal to -30° relative to the second axis of the array.

A still further aspect of the present invention provides a method of producing an array of abrasive sheets, comprising the step of cutting, from abrasive sheet material, an inventive array as described above. In one preferred embodiment, the method further comprises the step of cutting simultaneously, from the abrasive sheet material, a plurality of arrays. In another preferred embodiment, the method further comprising the step of collating the arrays into sets.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be further explained with reference to the appended

Figures, wherein like structure is referred to by like numerals throughout the several views, and wherein: Figure 1 shows an abrasive sheet; Figure 2 shows an array of the sheets shown in Figure 1 according to one embodiment of the present invention;

Figure 3 shows, diagrammatically, an apparatus for producing arrays as shown in Figure 2; Figure 4 shows, diagrammatically, the cutting face of the die cutter of the apparatus shown in Figure 3;

Figure 5 shows another abrasive sheet;

Figure 6 shows an array of the sheets shown in Figure 5 according to another embodiment of the present invention; Figures 7 to 13 show other embodiments of abrasive sheet arrays according to the present invention;

Figure 14 shows a chain of the arrays shown in Figure 2 according to the present invention;

Figure 15 shows yet another abrasive sheet; Figure 16 shows still another abrasive sheet;

Figure 17 shows a continuous array of abrasive sheets according to a further embodiment of the present invention;

Figure 18 shows the array of Figure 17 in a spiral-wound roll;

Figure 19 shows a side elevational view of a first embodiment of a dispenser according to the present invention for the array of Figure 17;

Figure 20 is a partial isometric view of the dispenser of Figure 19;

Figures 21 A and 21B are partial top plan views of the dispenser of Figure 19,

Figure 22 is a partial isometric view of an alternate embodiment of a dispenser according to the present invention; and Figure 23 is a top plan view of the dispenser of Figure 22.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows an abrasive sheet 1 which is generally triangular in shape. The sheet is a conventional coated abrasive comprising a substrate sheet which has abrasive grit particles bonded to it on one side. The other side of the substrate sheet is coated with a pressure-sensitive adhesive which is covered by a release liner. The release liner is optional and can be omitted, if appropriate.

Coated abrasive sheets of the type shown in Figure 1 are known. The substrate sheet may be any suitable material including, for example, paper, polymeric film and cloth. Likewise, the abrasive grit particles may be of any suitable type including, for example, fused aluminum oxide, boron carbide, silicon carbide, boron nitride, silicon nitride, diamond, flint, silica, iron oxide, garnet, fused alumina zirconia, ceramic aluminum oxides, and combinations of those materials. The abrasive sheet could also comprise a structured abrasive, such as of the type described in U.S. Patent No. 5,152,917 (Pieper).

The pressure-sensitive adhesive on the substrate sheet is provided to enable the abrasive sheet 1 to be mounted on a backing pad (the release liner having first been removed). The backing pad can then be connected to the output shaft of a powered tool for imparting a suitable movement to the abrasive sheet so that it can be used to sand or abrade a workpiece. The use of a pressure-sensitive adhesive for that purpose is not essential and any suitable alternative arrangement can be used to mount the abrasive sheet on a backing pad including, for example, a hook-and-loop fastening in which case one part of the fastening (i.e. either the hooks or the loops) would be carried by the abrasive sheet.

As an alternative, the sheet 1 need not be a coated abrasive but could be a nonwoven abrasive comprising a substrate of a porous, fibrous, nonwoven construction and an abrasive comprising individual abrasive particles on one side of the substrate. Such nonwoven abrasives are also known.

The abrasive sheet 1 shown in Figure 1 has sides which are approximately 65 mm long and, due to its shape and size, is particularly useful in areas such as corners which might be difficult to reach with a disc-shaped sheet. Sheets as shown in Figure 1 can be cut from a roll of abrasive sheet material using either a rotary die cutter or a flat bed die cutter but the comparatively small size of the sheets can result in a high amount of the sheet material being wasted and can also make the individual sheets difficult to handle. To reduce the wastage and the handling problems, in accordance with the present invention, the sheets 1 are not cut individually from the roll of abrasive sheet material but are cut as part of a generally polygonal array 2 of six sheets illustrated in Figure 2. The array 2 has a maximum cross-wise dimension of about 15.5 mm.

The array 2 comprises the six individual sheets 1 arranged to form a hexagon, with adjacent sheets being joined to each other by narrow connecting portions of the abrasive sheet material, which extend between the adjacent edges of the sheets 1.

Those connecting portions are simply locations at which one triangular sheet 1 has not been severed completely from the adjacent sheet and they are so small that they do not show in Figure 2 although the locations themselves are indicated schematically by the circles 3. It will be seen that there are two connecting locations 3 between the adjacent edges of each pair of adjacent sheets 1, at approximately 15 mm from the ends of the sides. Typically, the connecting portions have a width of from 1 to 2 mm, although the width, location and number of the connecting portions will depend on the size and shape of the abrasive sheets 1 and of the array 2.

Alternatively, instead of being joined by discrete connecting portions, adjacent sheets 1 of the array 2 could be joined through a line of weakness, for example a perforated or scored line. That line of weakness could extend the whole length of the joined edges of the adjacent sheets, or only part of that length.

The method of producing the array 2 is illustrated in Figure 3. Abrasive sheet material 4 (as described above for the triangular sheet 1) is pulled from a roll 5 onto the support frame 6 of a flat-bed die cutter 7. The sheet material is brought to a halt temporarily; the cutter 7 descends and cuts the material beneath it into a batch of arrays (each array being as shown in Figure 3); and the cutter then lifts again. The sheet material 4 is then pulled forward, until a new length is located beneath the cutter 7, whereupon it is brought to a halt again and the cutter 7 descends to cut a further batch of the arrays 2. The cutting process continues in that way until the required number of arrays has been cut. It should be noted that, in Figure 3, the arrays 2 are not depicted accurately for the sake of clarity: as will be clear from the description below, a much greater number of arrays is cut in the sheet material than is illustrated in Figure 3.

The cut sheet material is pulled forward from the support frame 6 towards a collecting surface 8 where the arrays 2 are separated from the remainder of the sheet material (i.e. the weed 9) by pulling the latter down below the collecting surface while the arrays 2 continue to move forwards and onto the collecting surface. The weed 9 is then wound, for subsequent disposal, onto a drum (not shown) which is located below the collecting surface 8. That drum also serves to exert the force that pulls the weed 9 forwards and, through it, the sheet material 4. The arrays 2 are collected by hand from the surface 8 and stacked, and they may then be packed in that form or they may be broken up into the individual sheets 1 and then packed. The star-shaped center part 2 A of each array (see Figure 2) is not joined to the remainder of the array and may remain in place when the array is collected, or it may fall out (or even be deliberately removed).

The type of apparatus illustrated in Figure 3 is well known for use in the production of cut abrasive sheets and it is believed that no further description of the apparatus is required.

The cutting face of the die cutter 7 is shown, diagrammatically, in Figure 4. The die cutter extends the full width of the sheet material 4 and is conventional except for the pattern in which the metal cutters 121 are arranged. Accordingly, only that pattern will be described here. As shown in Figure 4, the metal cutters define seventeen hexagonal shapes 122 (each corresponding to an array 2 as shown in Figure 2) arranged in two staggered rows of, respectively, eight and nine hexagonal shapes. Notches (not shown) are formed in the metal cutters 121 at the desired locations 3 of the connecting portions between the sheets so that the sheet material 4 will not be cut through at those locations. Neither the number nor the arrangement of the hexagonal shapes 122 defined by the metal cutters 121 is restricted to that shown in Figure 4. The cutters 121 could define a larger or smaller number of hexagonal shapes, arranged in any appropriate manner.

It is not essential for the die cutter 7 to extend for the full width of the sheet material 4. It could, for example, extend for only part of the width and be moved sideways after one cutting action so that one or more batches of arrays 2 can be cut from the remainder of the width of the sheet material. Alternatively, two die cutters could be provided side-by-side, each extending across half the width of the sheet material. It will be appreciated that, when a die cutter extends across part only of the width of the sheet material, a smaller number of arrays 2 will be cut in one operation.

When a user requires an individual triangular sheet 1, the hexagonal arrays 2 are readily separated by tearing the connecting portions that hold the triangular sheets together. The hexagonal arrays are, however, much easier to handle during production and much easier to pack than individual triangular sheets. They are also easier for the user to handle because the triangular sheets do not have to be separated until they are required. In addition, the amount of the abrasive sheet material 4 that is wasted during the cutting operation (Figure 3) can be reduced because it is possible to pack the hexagonal arrays 2 more effectively on the surface of the sheet material than individual triangular sheets.

Although Figure 3 shows only one layer of sheet material 4 being fed under the die cutter 7, it is well known that several layers of material can be fed onto the support frame 6 and cut at one time. It is also well known that the weed 9 can be pulled away from the cut arrays 2 in an upwards direction at the collecting surface 8, rather than downwards as shown in Figure 3. Moreover, although the above description has referred to sheet material which is provided with some means (e.g. a pressure sensitive adhesive) for attaching abrasive sheets to backing pads of powered tools, it would apply also to abrasive sheet material without such attachment means. The collection of the cut arrays 2 at the surface 8 need not be done manually. As one alternative, collecting cans may be provided at the end of the surface 8 in suitable locations to catch the arrays as they arrive. As yet another alternative, the arrays could be picked up pneumatically and transferred to a stacking location. It is, moreover, possible to use a rotary die cutter, rather than the flat bed cutter 7, to cut the sheet material 4, in which case the material 4 would move under the cutter continuously rather than in steps. It is also possible to laser cut the abrasive sheet array.

It will be appreciated that sheets of other shapes could also be cut from sheet material 4 in the form of arrays to facilitate handling. Figure 6, for example, shows an array 10 of six sheets 11 (one of which is shown in Figure 5) which are also generally triangular but which have rounded sides. The locations at which the sheets 10 are joined together are indicated schematically, as in Figure 2, by circles 3 and it will be seen that, in this array, there is only one connecting location between the adjacent edges of each pair of adjacent sheets 1. However, it will be seen that there is also a connecting location between the star-shaped center part 10A of the array and the adjacent apex of each sheet: in other words, in this array (unlike the array shown in Figure 2) the star-shaped center part 10A is not loose and is intended to remain in place until the sheets 10 are separated. Figs 5 and 6 also illustrate that the abrasive sheets 11 may be formed with apertures 12 through which dust can be removed from a workpiece when a sheet is in use on a powered tool. Those apertures 12 can, of course, be cut by the die cutter 7 at the same time as the array 10 is cut.

Some further abrasive sheet arrays are illustrated in Figures 7 to 13. The array 13 shown in Figure 7 is another array of generally triangular sheets (in this case, ten sheets) of the type shown in Figure 1. Figure 8 shows an array 15 of seven circular sheets 16, and Figures 9 and 10 show arrays 17, 18 respectively of rectangular sheets 19, 20 respectively. Figures 11 and 12 show further, generally polygonal, arrays 21, 23 of triangular sheets 22, 24 respectively, the array of Figure 11 being generally square and that of Figure 12 being generally pentagonal. Figure 13 shows an array 25 similar to that of Figure 6 except that the sheets 26 have a more elongated form. In each of the arrays, the connecting locations between adjacent sheets are indicated schematically by the circles 3 (as in Figures 2 and 6), and the size, number and location of those connections can be altered as appropriate.

In general, the advantages of cutting arrays of abrasive sheets, rather than individual sheets, will probably be most apparent for sheets that have sides smaller than 120 mm (or, in the case of circular sheets, a diameter of less than 120 mm). However, arrays of larger sheets could be cut if required. It is, moreover, not essential that the arrays always be cut with other arrays of the same shape: it would, for example, be possible for arrays of the type shown in Figure 8 to be cut from the same length of sheet material as arrays of the type shown in Figure 2.

In each of the arrays described above, the adjacent sheets in an array could be spaced apart slightly instead of being contiguous although that would generally result in a greater waste of sheet material 4. It is also possible for adjacent arrays to be joined together, for example in a line (as shown in Figure 14 for arrays of the type shown in Figure 2). As already mentioned, it is known to cut abrasive discs in a chain with adjacent discs being joined by tabs, and the adjacent arrays 2 in Figure 14 could be joined in a similar manner.

Figure 15 shows another embodiment of a generally triangular abrasive sheet 31 useful with the present invention. Abrasive sheet 31 includes three faceted corners 32 formed by edges 33 and 34 which meet at an included angle larger than the angle ordinarily formed by the sides of a triangle. For example, for an equilateral triangle, the corners would form an included angle of 60°, whereas edges 33 and 34 meet at any included angle larger than 60°. In one embodiment, the edges 33 and 34 meet at approximately 90°. Abrasive sheet 31 can be formed into any of the arrays described above with respect to the other generally triangular sheets described herein. Figure 16 shows illustrative triangle 40, which is convenient for describing the inventive arrays described herein. As discussed further below, it is understood that when an array is described as including a generally triangular abrasive sheet, this is meant to include not only sheet 40 as illustrated in Figure 16, but also the other generally triangular sheets illustrated herein, such as sheet 1, 11, 22, 24, 26, and 31, and any other form of a generally triangular abrasive sheet. Triangular sheet 40 includes first edge 41, second edge 42, and third edge 43. Sheet 40 also includes first corner 44 between edges 41 and 43, second corner 45 between edges 41 and 42, and third corner 49 between edges 43 and 41. When triangular sheet 40 is a generally isosceles triangle, it includes first line of symmetry 47. The term generally isosceles triangle is understood to include generally triangular shapes having a single line of symmetry, such as sheet 26 of Figure 13. Such generally isosceles triangles can include rounded corners as illustrated in Figure 1, rounded edges as illustrated in Figures 5 and 13, and faceted corners as illustrated in Figure 15. When abrasive sheet 40 is a generally equilateral triangle, it also includes second and third lines of symmetry 48 and 49. The term generally equilateral triangle is understood to include generally triangular shapes having a three lines of symmetry. Such generally equilateral triangles can include rounded corners as illustrated in Figure 1, rounded edges as illustrated in Figures 5 and 13, and faceted corners as illustrated in Figure 15. Abrasive sheet 40 also includes a narrow end 50 and a wide end 51 opposite from the narrow end. For a generally triangular abrasive sheet, three opposed pairs of narrow and wide ends can be defined.

Figure 17 shows continuous array 60 of abrasive sheets 40. While array 60 is illustrated as including triangular abrasive sheets 40, it is understood that array 60 can be formed with any generally triangular abrasive sheets, including any of the generally abrasive triangular sheets illustrated and described herein. Continuous array 60 includes longitudinal axis 61 and transverse axis 62. Array 60 also includes first end 63 and second end 64. The array 60 is characterized in that adjacent sheets 40 are arranged such that any individual sheet 40 has its narrow end 50 adjacent the wide ends 51 of the abrasive sheets immediately on either side. In this manner, the generally triangular abrasive sheets can be efficiently packaged so as to minimize waste material in continuous sheet 4 (described above) between the adjacent abrasive sheets 40. When abrasive sheets 40 are generally equilateral triangles, they are preferably oriented so as to have any of the three lines of symmetry 47, 48, 49 along the transverse axis 62 of the array 60. When abrasive sheets 40 are generally isosceles triangles, they are preferably oriented so as to have the single line of symmetry 47 along the transverse axis 62 of array 60.

The edges of adjacent sheets 40 can be configured as described above to provide for convenient separation of the individual sheets from the array. For example, the adjacent sheets can be connected by connecting locations 3 as described above, or by any weakened line such as a score line or perforated line.

As shown in Figure 18, continuous array 60 can be provided in a spirally wound roll 65. In the embodiment illustrated, first end of the array 63 is exposed at the outside of roll 65, while second end 64 of the array 60 is at the center of the roll 65.

As each individual sheet 40 is removed from the array 60, the next adjacent sheet 40 then becomes available at the first end 63. As shown in Figure 17, the edge of the abrasive sheet at the first end 63 is oriented such that exposed edge (a) is at an angle β relative to the transverse axis 62 of the array 60. To remove the end sheet B, it is necessary to separate the end sheet B from adjacent sheet C along edge (b). It is seen that edge (b) between adjacent sheets B and C is at angle α relative to the transverse axis 62. To remove the next abrasive sheet C from the array 60, it is necessary to separate it from sheet D along edge (c). The next sheet D then separated along edge (d), and so on. When the abrasive sheets 40 are generally equilateral triangles, angle β is at an angle of -30° relative to the transverse axis 62, while angle α is at an angle of +30° relative to the transverse axis 62. If the abrasive sheets are generally isosceles triangles, then angles α and β will be of some angle different than 30°, and will be of substantially equal magnitude and opposite orientation. It is thus seen that as each successive abrasive sheet 40 is removed from the array 60, it is necessary to separate successive sheets along a first angle α relative to the transverse axis 62 and then the next sheet along opposite and equal second angle β relative to the transverse axis.

Figure 19 shows a dispenser 66 which is particularly useful for dispensing abrasive sheets 40 from array 60 described above. Dispenser 66 includes box 67 which is configured to hold roll 65 within the box 67, such as on a spindle (not illustrated) placed through the core of roll 65. Alternatively, the roll 65 can sit loose in the box 67, or can be supported by any other suitable means as is well known in the art. In another embodiment, the array 60 is "z-folded" to lay in the box 67, rather than being wound into a roll. Box 67 is shown as being generally rectangular and being closed on each side, although other box configurations are within the scope of the invention.

As seen in greater detail in Figure 20, box 67 includes a first wall 68 which has therethrough an opening 69 defined by opposed first and second opening edges 70a and 70b. Opening 69 is provided for feeding the abrasive sheet array 60 out of the dispenser 66. Mounted along edge 70a of the opening 69 is first abrasive sheet separator 71 and mounted along second edge 70b of opening 69 is second abrasive sheet separator 81. First and second separators 71, 81 provide a convenient means for separating each abrasive sheet 40 from the first end 63 of the array 60. As explained below, the first and second separators are configured to separate alternating ones of the successive abrasive sheets 40 from the array 60.

First separator 71 includes first separating edge 72 extending from first end 73 to second end 74. First end 73 of first separating edge 72 is closer to wall 68 than is second end 74. Therefore, first separating edge 72 is at an oblique angle relative to the plane of first wall 68. Likewise, second separator 81 includes second separating edge 82 extending from first end 83 to second end 84. First end 83 of second separating edge 82 is closer to wall 68 than is second end 84. Therefore, second separating edge 82 is at an oblique angle relative to the plane of first wall 68. The separators 71, 81 together define a separating means configured to receive the array 60 in direction X, the first axis of the separator means.

In a preferred embodiment, the first and second separating edges 72, 82 are at equal and opposite angles relative to the plane of the wall 68. Figure 21 A is a top view of dispenser 66, showing first separator 71 (second separator 81 is omitted from Figure 21 A for clarity). First separating edge 72 is at an angle α relative to the plane of wall 68, with angle α of the separating edge 72 corresponding to angle α at edges (b) and (d) of the array 60 illustrated in Figure 17. Thus, to separate the end abrasive sheet B from the array 60, the end abrasive sheet can be pulled upward against the first separator 71, with edge (b) of the abrasive sheet aligned along first separating edge 72. Second separator 81 is illustrated in Figure 2 IB (from which first separator 71 has been omitted for clarity). Second separating edge 82 is at angle β relative to the plane of wall 68, with angle β of the separating edge 82 corresponding to angle β at edges (a) and (c) of the array 60 of Figure 17. The separator means has a second axis Y perpendicular to the first axis X, and parallel to the plane defined by the abrasive sheets in the array 60 as they pass through the separators. To separate abrasive sheet C from the array 60, sheet C is pulled downward against second separator 81, with abrasive sheet edge (c) aligned along second separating edge 82. Abrasive sheet D can then be separated from the array 60 by pulling sheet D upward against the first separator 71 , with edge (d) of the abrasive sheet aligned with first separating edge 72, and so on. In a preferred embodiment, when generally equilateral triangle abrasive sheets 40 are used, angle α is +30° relative to wall 68 while angle β is -30° relative to wall 68. When the abrasive sheets of the array 60 are generally isosceles triangles, angles α and β of first and second separating edges 72, 82, respectively, are of some magnitude other than 30°, and are of equal magnitude and opposite orientation. Whatever the configuration of the abrasive sheets 40, the orientations of the first and second separating edges 72, 82 are chosen to correspond to the respective alternating orientation of the edges between adjacent sheets of the array 60. Figures 22 and 23 show an alternate embodiment of the abrasive sheet separator 91 mounted on first wall 68 of box 67. Separator 91 is mounted proximate the second opening edge 70b of opening 69. Separator 91 includes a first separating edge 92 and a second separating edge 93. First separating edge 92 extends from first end 94 to apex 95, and is orientated at first angle α relative to the plane of the wall 68. Second separator edge 93 extends form apex 95 to second end 96, and is oriented at second angle β relative to the plane of the wall 68. The separator receives the array in direction A, the first axis of the separator. The separator also has axis Y, perpendicular to the first axis X and lying in the plane defined by the abrasive sheets as they pass by the separator. In this embodiment, abrasive sheet B is separated from array 60 of Figure 17 by pressing sheet B down against the separator 91 with edge (b) aligned with first separator edge 92. Abrasive sheet C is then separated form the array 60 by pressing sheet C down against separator 91 with edge (c) aligned with second separating edge 93. Abrasive sheet D is then separated form array 60 by pressing sheet D down against the separator 91 with edge (d) aligned with first separating edge 92, and so on. Opening 69 and separator 91 are wide enough to allow the abrasive sheet array 60 to be shifted back and forth so as to engage either separator edge 92, 93. In one preferred embodiment, slot 69 and separator 91 are approximately twice as wide as array 60.

Box 67 can be of any material conventionally used for such boxes, such as cardboard, paperboard, plastic, or the like. Separators 71, 81, and 91 can be of any suitable material such as plastic or metal, and must be strong enough to allow the abrasive sheets to be separated. First and second separators 71, 81 are illustrated as separate pieces; however it is understood that separators 71, 81 can be a single unit, if desired. Separators 71, 81, and 91 can be a separate piece from the box 67, or can be unitary with wall 68 of box 67. Separating edges 72, 82, 92, 93 can be sharp edges, serrated edges, or any other suitable configuration.

It is also possible to use the separators 71, 81, 91 with arrangements other than the box 67 described above. For example, an array can be mounted or stored on a spool without a box 67, with the separator mounted an a suitable support to receive the array from the spool. In one such arrangement, the dispenser is attached to the spool by a suitable framework as is within the knowledge of those skilled in the art. In another such arrangement, the separator is mounted on a shelf or work surface with a means for storing the array also mounted on the shelf behind the separator. It is understood that many such arrangements are possible and are within the knowledge of one skilled in the art. What is common to these arrangements is that the separator 71, 81, 91 be provided in a suitable location to receive the array 60, regardless of the particular means chosen to store or support the array, or the particular form of the array (i.e., roll, z-fold, etc.).

The present invention has now been described with reference to several embodiments thereof. The foregoing detailed description and examples have been given for clarity of understanding only. No unnecessary limitations are to be understood therefrom. It will be apparent to those skilled in the art that many changes can be made in the embodiments described without departing from the scope of the invention. Thus, the scope of the present invention should not be limited to the exact details and structures described herein, but rather by the structures described by the language of the claims, and the equivalents of those structures.

Claims

CLAIMS;

1. An abrasive sheet array comprising: a plurality of abrasive sheets joined together and readily detachable from each other, wherein each of the abrasive sheets is generally triangular and includes a narrow end and a wide end opposite the narrow end, and wherein the array is generally polygonal.

2. The array of claim 1, wherein the abrasive sheets are joined together by the material from which the sheets are formed.

3. The array of claim 1, wherein each abrasive sheet comprises a substrate material having a first side and a second side, the substrate having abrasive material on the first side and means for releasably attaching the abrasive sheet to a drive member on the second side.

4. The array of claim 1, wherein the abrasive sheets are joined to each other at discrete locations on the edges of the sheets.

5. The array of claim 1, wherein the array comprises a plurality of abrasive sheets arranged so as to have the narrow end of each sheet adjacent the narrow end of each adjacent abrasive sheet and so as to have the wide end of each sheet adjacent to the wide end of each adjacent sheet.

6. The array of claim 5, comprising four abrasive sheets forming a generally square array.

7. The array of claim 5, comprising five abrasive sheets forming a generally pentagonal array.

8. The array of claim 5, comprising six abrasive sheets forming a generally hexagonal array.

9. The array of claim 1, wherein the array comprises a plurality of abrasive sheets arranged so as to have the narrow end of each abrasive sheet adjacent the wide end of each adjacent abrasive sheet.

10. The array of claim 9, wherein the array has a first end and a second end opposite the first end, a longitudinal axis extending in the direction from the first end to the second end and a transverse axis peφendicular to the longitudinal axis, and wherein each abrasive sheet has at least one line of symmetry, wherein each abrasive sheet is arranged so as to have its line of symmetry parallel to the transverse axis of the array.

11. The array of claim 10, wherein adjacent first and second abrasive sheets are joined along a first line forming a first angle relative to the transverse axis of the array, and wherein a third abrasive sheet is joined to the second abrasive sheet along a second line opposite the first line, the second line forming a second angle relative to the transverse axis of the array.

12. The array of claim 11, wherein the first and second angles are of substantially equally magnitude and are of opposite orientation relative to the transverse axis of the array.

13. The array of claim 9, wherein the array is spirally wound so as to form a roll of abrasive sheets.

14. A dispenser for storing an array of abrasive sheets and for separating abrasive sheets from the array, the dispenser comprising: a box configured to store the array of sheets, the box including a first wall having an opening therein for dispensing the array from inside the box to outside the box, the opening bounded by first and second opening edges; and abrasive sheet separating means mounted on the first wall, the separating means comprising a first separator edge oriented at a first edge angle relative to the first wall and a second separator edge oriented at a second edge angle relative to the first wall.

15. The dispenser of claim 14, wherein the separator means comprises: a first abrasive sheet separator mounted on the first wall proximate the first edge of the opening, the first separator including the first separator edge; and a second abrasive sheet separator mounted on the first wall proximate the second edge of the opening, the second separator including the second separator edge.

16. The dispenser of claim 14, wherein the first edge angle and the second edge angle are of substantially the same magnitude and of opposite orientation relative to the first wall of the dispenser.

17. The dispenser of claim 14, wherein the first edge angle is substantially equal to +30° relative to the first wall and wherein the second edge angle is substantially equal to -30° relative to the second wall.

18. A separator for separating individual abrasive sheets from an array of abrasive sheets, the array including a plurality of abrasive sheets arranged along the longitudinal axis of the array, with the individual sheets each joined on a first side to a first respective adjacent sheet generally along a first line at a first angle relative to the transverse axis of the array and joined on a second side to a second respective adjacent sheet generally along a second line at a second angle relative to the transverse axis of the array, the separator comprising: separator means configured to receive the array in a direction along the first axis of the separator means, the separator means having a second axis peφendicular to the first axis and lying in the plane defined by the abrasive sheets as they pass through the separator means; the separator means including a first separator edge oriented at a first edge angle relative to the second axis and a second separator edge oriented at a second edge angle relative to the second axis.

19. The separator of claim 18, wherein the separator means comprises: a first abrasive sheet separator including the first separator edge; and a second abrasive sheet separator including the second separator edge, wherein the first and second separators are provided opposite to one another and are configured to receive the array between the first and second separators.

20. The separator of claim 18, wherein the first edge angle and the second edge angle are of substantially the same magnitude and of opposite orientation relative to the second axis.

21. The separator of claim 18, wherein the first edge angle is substantially equal to +30° relative to the second axis and wherein the second edge angle is substantially equal to -30° relative to the second axis of the array.

22. A method of producing an array of abrasive sheets, comprising the step of cutting, from abrasive sheet material, an array according to claim 1.

23. The method of claim 22, further comprising the step of cutting simultaneously, from the abrasive sheet material, a plurality of arrays.

24. The method of claim 22, further comprising the step of collating the arrays into sets.