GB2298154A - Abrasive tool comprising abrasive sheets retained on mounting pin by deforming the pin - Google Patents

Abstract

In an abrasive tool eg. in the form of an abrasive mop 10 including a number of abrasive sheets 12 such as cruciform shaped sheets of resin bonded zinc stearated adhesive cloth, the sheets being cut or slashed to define strips or tails and located on a mounting pin 16 adapted to be held in the drill chuck or collet of a power tool, the sheets 12 are held between two retaining members eg. dished metal discs 18,20, the first disc being retained on the pin 16 by a machined stop 22 and the second disc 20 being retained on the end 26 othe pin by deforming the hollow end of the pin outwardly eg. in a press which also serves to compress the sheets 12 and washers 24.

Description

ABRASIVE TOOL This invention relates to an abrasive tool and in particular, but not exclusively, to an abrasive mop and a method of producing such mops.

Abrasive mops typically comprise a plurality of rectangular sheets of abrasive cloth mounted on a pin or rod for location in the chuck or collet of a power tool.

The outer edges of the sheets are cut to form strips or tails such that the sheets collectively form a soft mop, which will follow the contours of the piece to be abraded.

The mops are assembled by positioning the sheets, and appropriate spacer washers, on one end of the pin and then forming retaining members on the pin from pourable resin material which, when cured, hold the sheets in place. The cured resin is then dressed. This assembly process is relatively time consuming and thus adds disproportionably to the cost of the mops.

It is one of the objects of the present invention to obviate or mitigate this disadvantage.

According to a first aspect of the present invention there is provided an abrasive tool comprising a mounting pin having one end for location in a chuck or collet of a power tool and a plurality of abrasive sheets mounted on the other end of the pin, the abrasive sheets being positioned between first and second retaining members, at least one of the retaining members being fixed on the pin by deformation of a portion of the pin.

According to a second aspect of the present invention there is provided a method of making an abrasive tool comprising the steps: providing i) ,a mounting pin adapted for location in a chuck or collet of a power tool and defining a stop, ii) a plurality of abrasive sheets each defining an aperture, and iii) first and second retaining members each defining an aperture; locating a first retaining member on the pin against the stop; locating the abrasive sheets on the mounting pin, with the pin passing through the sheet apertures, and abutting the first retaining member; locating the second retaining member on the pin and abutting the abrasive sheets; and deforming the end of the pin to hold the second retaining member on the pin.

Preferably the abrasive sheets each define a noncontinuous circumference and are, for example, cruciform or star-shaped or formed of a plurality of strips or fingers, such that the members collectively form an abrasive mop.

Most preferably, the abrasive sheets are of cruciform shape. This provides four circumferentially spaced abrasive portions for each abrasive sheet, in contrast to conventional arrangements in which the rectangular abrasive sheets only provide two abrasive portions, such that twice as many abrasive sheets must be incorporated in the mop to provide the same number of abrasive portions. The use of the cruciform abrasive members thus reduces the area of abrasive material required to form a mop, and thus the thickness and cost of the mop. The cruciform shape also permits large sheets of abrasive material to be cut to form the individual abrasive sheets with little or no waste.

Preferably also, the pin includes a unitary stop for the first retaining member which may be formed or machined on the pin.

Preferably also, the end of the pin to be deformed is hollowed or otherwise weakened to facilitate deformation.

Preferably also, the retaining members are dished, to more firmly compress the central portions of the abrasive members.

Conveniently, the abrasive sheets are formed of flexible paper or cloth carrying abrasive particles on at least one side. Most preferably, a lubricating coating, such as zinc stearate, is provided over the abrasive particles, which assists in preventing clogging of the abrasive surface.

These and other aspects of the present invention will now described, by way of example, with reference to the accompanying drawings, in which: Figure 1 is a side view of the elements of an abrasive tool in accordance with a preferred embodiment of the present invention prior to assembly; Figure 2 is a side view of the tool of Figure 1, show assembled; and Figure 3 is a plan view of a sheet of abrasive cloth cut to provide the individual abrasive sheets of the tool of Figure 1.

Figures 1 and 2 of the drawings illustrate an abrasive tool in the form of an abrasive mop 10 comprising a number of cruciform shaped sheets of resin bonded zinc stearated adhesive cloth 12, the cloth being cut or slashed to define strips or tails 14. The soft mop formed by the tails 14 follows the contours of the piece to be sanded and can be used, depending on the grade of abrasive cloth, for a wide variety of sanding operations such as removing old paint, varnish, or rust, sanding wood and between coat denibbing wood.

The abrasive cloth sheets 12 are located on a mounting pin 16 adapted to be held in the drill chuck or collet of a power tool. The sheets 12 are held between two retaining members in the form of dished metal discs 18, 20. The first disc 18 is retained on the pin 16 by a machined stop 22. The abrasive sheets 12 are positioned on the end of the pin, below the stop 22 and the disc 18, together with a number of fibre spacer washers 24. The second disc 20 is retained on the end of the pin 26 by "mushrooming" or otherwise deforming the hollow end of the pin outwardly in a press, which also serves to compress the sheets 12 and washers 24. The discs 18, 20 are dished slightly such that the central portions of the sheets 12 are subject to a greater degree of compression.

The cruciform shape of the sheets 12 is more clearly shown in Figure 3 of the drawings, which illustrates a large sheet of abrasive cloth 30 following die cutting to form the sheets 12. It will be noted that there is very little waste of the expensive abrasive cloth and also that each individual sheet 12 provides four circumferentially spaced abrasive portions 32.

Conventional mops are formed of rectangular sheets, such that each sheet provides only two abrasive portions.

Thus, to provide a comparable mop, only half as many cruciform-shaped sheets 12 are necessary, with corresponding savings in material, and'the thickness of the mop may be reduced by a half.

It will be clear to those of skill in the art that the above-described embodiment is merely exemplary of the present invention and that various modifications and improvements may be made thereto without departing from the scope of the invention.

Claims (10)

1. An abrasive tool comprising a mounting pin having one end for location in a chuck or collet of a power tool and a plurality of abrasive sheets mounted on the other end of the pin, the abrasive sheets being positioned between first and second retaining members, at least one of the retaining members being fixed on the pin by deformation of a portion of the pin.

2. The tool of claim 1 in which the abrasive sheets each define a non-continuous circumference.

3. The tool of claim 2 in which the abrasive sheets are of cruciform shape.

4. The tool of any of the preceding claims in which the pin includes a unitary stop for the first retaining member.

5. The tool of any of the preceding claims in which the retaining members are dished, to more firmly compress the central portions of the abrasive members.

6. The tool of any of the preceding claims in which the abrasive sheets are formed of flexible paper or cloth carrying abrasive particles on at least one side.

7. The tool of claim 6 in which a lubricating coating is provided over the abrasive particles.

8. A method of making an abrasive tool comprising the steps: providing i) a mounting pin adapted for location in a chuck or collet of a power tool and defining a stop, ii) a plurality of abrasive sheets each defining an aperture, and iii) first and second retaining members each defining an aperture; locating a first retaining member on the pin against the stop; locating the abrasive sheets on the mounting pin, with the pin passing through the sheet apertures, and abutting the first retaining member; locating the second retaining member on the pin and abutting the abrasive sheets; and deforming the end of the pin to hold the second retaining member on the pin.

9. The method of claim 8 in which the end of the pin to be deformed is hollowed or otherwise weakened to facilitate deformation.

10. An abrasive tool substantially and as described herein and as illustrated in Figures 1 and 2 of the accompanying drawings.