SANDING DEVICE

Abstract

A sanding device comprising a core and with a surface having a plurality of bristles and pieces of abrasive cloth secured to it. According to the invention said pieces of abrasive cloth being secured to said surface by use of fastening elements extending through said abrasive cloth and into said core.

Description

The invention relates to a device for performing sanding operations, the sanding device comprising; a core having a surface; a plurality of bristles being secured to said core and extending from said surface; and a plurality of pieces of abrasive cloth extending from the surface.

BACKGROUND OF THE INVENTION

Sanding devices are used among others within the woodworking, metal, plastic and furniture industries and may be used for surface treatment or sanding of plane and curved surfaces for providing smooth surfaces. Sanding devices usually comprise a combination of brushes and sanding means. The function of the brushes is to ensure a certain application pressure between the sanding means and the items to be sanded.

U.S. Patent application No. 2003/0092370 discloses a sanding strip for use with a sanding wheel. The sanding strips are anchored in undercut grooves in a sanding wheel thereby comprising a sanding device. The disclosed sanding strip comprises a profiled rail wherein a line of bracing elements or brushes is secured. Sanding means are secured to one side of the line of brushes by means of glue.

In a sanding device the expected life time of the sanding means is usually way below the life time of the brushes. When the sanding means have been worn down either the entire sanding device or only the sanding means have to be replaced. When the uptime of a production line is crucial, it is undesirable to waste valuable time on changing sanding means one by one. Changing and discarding of known sanding device may be both economically and environmentally undesirable.

SUMMARY OF THE INVENTION

The present invention seeks to provide an inexpensive alternative to existing sanding devices.

This is achieved by the device comprising: a core having a surface; a plurality of bristles being secured to the core and extending from the surface; a plurality of pieces of abrasive cloth extending from the surface; wherein the pieces of abrasive cloth are secured to the surface by use of fastening elements extending through the abrasive cloth and into the core. Hereby the pieces of abrasive cloth are secured to the core by simple and inexpensive means. The core may be solid or it may be a cylindrical shell.

In one embodiment staples are used as fastening elements. An advantage in this respect is that the pieces of abrasive cloth may be easily fastened and changed without the use of advanced tools.

In another embodiment, reinforcement strips are arranged on top of the pieces of abrasive cloth, and the staples extend through the reinforcement strip, the abrasive cloth and into the core. An advantage in this respect is that the reinforcement strip prevents tearing of the abrasive cloth by the staples, when forces are applied to the cloth.

In another embodiment the pieces of abrasive cloth are secured to the surface or to the bristles by use of glue. Hereby staples may be applied only for securing the abrasive cloth during curing of the glue. If staples are used in a combination with glue, the construction may be strengthened, tear of the abrasive cloth may be prevented, and the number of staples may be reduced.

In a still further embodiment, the abrasive cloth is secured to the sanding device 1 by gluing and/or stapling of the abrasive cloth to the bristles. In this embodiment the abrasive cloth need not be secured to the surface of the cylindrical core.

In another embodiment, the sanding device comprises different pieces of abrasive cloth with different grit sizes. Hereby the sanding device has one grit size when it is rotated in one direction and another or the same grit size when it is rotated in the opposite direction.

Instead of a single layer of abrasive paper, it is an option according to one embodiment that two or more layers of abrasive paper are provided, like a sandwich. When the outermost layer is worn, the layer behind will overtake the sanding.

According to another embodiment, several rows of bristles may also be provided between two pieces or two sandwiches of abrasive paper, to the effect that two or three bristles, seen in the peripheral direction, support the abrasive paper.

In another embodiment, the core is made from a material comprising a filler material and a binding material. An advantage in this respect is that the properties of the core material may be varied according to the specific construction of the sanding device. By using different types of filler material, binding material and combinations thereof, the core may be of lighter weight, less expensive to produce, easier to dispose of, etc. The core may also be designed in accordance with means for securing bristles and/or pieces of abrasive cloth to the core. E.g. when staples are used as fastening means, the core may be designed with properties especially suitable for receiving staples.

In one embodiment the filler material comprises a recycled material. Hereby the sanding device, particularly the core, may be less expensive to produce, and the sanding device may de disposed of in an environmental-friendly way.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following, the invention will be described in greater detail with reference to embodiments shown by the enclosed figures. It should be emphasized that the embodiments shown are used for exemplary purposes only and should not be used to limit the scope of the invention.

FIGS. 1a, b, c illustrate different ways of securing abrasive cloth to a sanding device.

FIGS. 2a, b are perspective views of cylindrical cores with differently arranged holes.

FIG. 3 is a perspective view of a cylindrical core with holes and only one row of extending bristles.

FIG. 4 is a perspective view of a cylindrical core with only one section of abrasive cloth secured to the surface of the core.

FIG. 5 illustrates end pieces for the sanding device.

FIG. 6 illustrates a disc-shaped sanding device according to one embodiment of the invention.

DESCRIPTION

With reference to the drawings a sanding device 1 comprising an elongated cylindrical core 10, a plurality of bristles 12 and pieces of abrasive cloth 11 will be described in the following.

The cylindrical core 10 has a surface 20 with a plurality of holes 21. In the embodiments shown the cylindrical core 10 is hollow with an appropriate wall thickness. The cylindrical core may be manufactured from a material comprising a filler material and a binding material.

The filler material may be paper, recycled paper, paperboard, fibreboard, cardboard, wood chips, plastic, recycled material, etc., but it is not limited hereto. The filler material may have many different configurations such as, but not limited to, granulate, chips, sheets, layers, film, etc.

The binding material may be some kind of glue, such as polyvinyl acetate glue, but not limited hereto, preferably chosen in accordance with other constructional parameters of the sanding device 1 as described below.

A plurality of bristles 12 are arranged in the holes 21 and secured therein preferably by staples and/or glue. The bristles 12 may be arranged in different patterns along the cylindrical core 10, preferably in straight lines parallel to an axis of rotation 22 or in lines twisting around the cylindrical core 10 creating a spiral-like pattern. The axis of rotation 22 is defined as a line in space extending through the centre of the cylindreical core 10 in the longitudinal direction. The bristles 12 extend substantially radially from the surface 20 of the core 10.

Referring to FIG. 1a, sections of abrasive cloth 11 are arranged between the bristles 12. In the shown embodiment, the abrasive cloth 11 is in the form of bent, elongated pieces of cloth secured to the surface of the core 10 by fastening means 13 such as, but not limited to, staples. Staples 13 are placed along a middle section of the abrasive cloth 11 in the longitudinal direction. The abrasive cloth 11 thus has a shape resembling a U with the staples placed in the bottom part.

Referring to FIG. 1b, an embodiment of the inventions is shown where the abrasive cloth 11 is secured to the surface of the cylindrical core 10 by staples arranged along a longitudinal edges of the pieces of abrasive cloth 11. In a still further embodiment as shown in FIG. 1c, two pieces of abrasive cloth 11 are secured to the surface of the cylindrical core 10 by staples arranged in an overlapping section between the two pieces of abrasive cloth 11. By utilizing two separate pieces of abrasive cloth 11, it is possible to have a sanding device 1 with abrasive cloth having different grit sizes. Hereby the sanding device has one grit size when it is rotated in one direction and another grit size when it is rotated in the opposite direction. The abrasive cloth 11 extends substantially radially from the surface of the cylindrical core 10 and may be in abutment with the bristles.

When securing the abrasive cloth by using staples 13 it may be advantageous to use a reinforcement strip, e.g. a piece of cardboard, arranged on top of the pieces of abrasive cloth in the region where the staples are applied. By inserting the staples through both the reinforcement strip and the abrasive cloth, the tear resistance of the construction is improved.

In an alternative embodiment, the pieces of abrasive cloth 11 may be secured to the surface for the core 10 by use of some kind of Velcro. By having mating pieces of Velcro on the pieces of abrasive cloth 11 and the core 10, respectively, the abrasive cloth 11 may be removably secured to the core 10.

The cylindrical core described above may be used in many different types of sanding devices. Abrasive cloth and/or bristles may alternatively be secured in grooves in the core 10. By utilizing grooves, the abrasive cloth and/or bristles may be arranged in fastening strips adapted to be inserted in the grooves. A fastening strip may comprise several bristles 12 or pieces of abrasive cloth 11 arranged side by side. Fastening strips are widely used in known sanding devices.

The binder used in the core material and the staples and/or glue used for securing the abrasive cloth 11 to the core 10 may be chosen in accordance with each other. It is desirable that the hardness and consistency of the core material are suitable for the utilized fastening means.

FIG. 5 shows end pieces 30 for the sanding device 1. Different types of end pieces 30 can be mounted on the sanding device 1. The end pieces 30 can be standard end pieces or custom-made according to the specific use. The end pieces 30 may preferably have a hole diameter ranging from 6 mm to 80 mm. In the shown embodiment, the end pieces 30 have hexagonal-shaped holes 31. The sanding device 1 may be mounted in a sanding apparatus by insertion of a shaft (not shown) through the hexagonal-shaped holes 31 in each of the end pieces 31. In an alternative embodiment, the sanding device 1 may be mounted by only inserting a shaft through a hole 31 in one of the end pieces 30.

In an alternative embodiment as shown in FIG. 6 the cylindrical core 10 is substituted with a disc-shaped core 10b having a top surface 20b with a plurality of holes. In this embodiment, the plurality of bristles 12 and the pieces of abrasive cloth 11 extend in a direction perpendicular to the top surface 20b of the disc 10b. This direction corresponds to the direction of the axis of rotation of the disc. The bristles 12 and the pieces of abrasive cloth 11 are secured to the disc-shaped core 10b with means similar to the means used for securing bristles and the pieces of abrasive cloth to the cylindrical core. The disc-shaped core may have a shaft 20 extending from the centre of the disc and from a side opposite the top surface. The shaft thus extends in a direction opposite to the bristles and the pieces of abrasive cloth and parallel to the axis of rotation. Alternatively the shaft may be arranged excentrically and the disc core may be weighted to the effect that the abrasive paper entails an excentric movement.

The base plate may be manufactured from a material comprising a filler and a binding material. The filler may be paper, recycled paper, paperboard, fibreboard, cardboard, wood chips, plastic, recycled material, etc., but is not limited hereto. The binding material may be some kind of glue, such as polyvinyl acetate glue, but not limited hereto.

The embodiment comprising as disc shaped core may be used in both a commercial sanding apparatus and in connection with power tools, such as, but not limited to, a hand-held drilling machine. The sanding device may be mounted on a drilling machine by connecting the shaft 20 of the sanding device with the drill chuck or other means for securing equipment to a drilling machine.

Use of the Invention

Having described the sanding device in detail, its use and operation will be described in further detail below.

A sanding device 1 according to the invention is mounted in a sanding apparatus as described above. When the shaft is rotated, the sanding device 1 rotates accordingly. Depending on the specific embodiment, the sanding device may be rotated either clockwise, counter-clockwise or a combination of the two. Thus, when the abrasive cloth 11 has been worn sufficiently on one side, the rotation may be reversed to utilize the opposite side of the abrasive cloth 11. When the abrasive cloth 11 has been worn sufficiently, either the entire sanding device 1 or only the abrasive cloth 11 may be replaced. The abrasive cloth 11 may be replaced by removal of the used abrasive cloth 11 and securing of new pieces of abrasive cloth to the sanding device 1. This may be done by stapling of new pieces of abrasive cloth to the surface of the cylindrical core 10 or by securing of pieces of abrasive cloth to the sanding device 1 according to any one of the above-mentioned embodiments.

Claims

1. A sanding device for performing sanding operations, said sanding device comprising:

a core having a surface;

a plurality of bristles being secured to said core and extending from said surface;

a plurality of pieces of abrasive cloth extending from said surface;

characterized in said pieces of abrasive cloth being secured to said surface by use of fastening elements extending through said abrasive cloth and into said core.

2. A sanding device according to claim 1, wherein said fastening elements are staples.

3. A sanding device according to claim 1, wherein reinforcement strips are arranged on top of said pieces of abrasive cloth, and said staples extend through said reinforcement strip and said abrasive cloth and into said core.

4. A sanding device according to claim 1, wherein said pieces of abrasive cloth are secured to said surface by use of glue.

5. A sanding device according to claim 1, wherein said pieces of abrasive cloth are glued to said bristles.

6. A sanding device according to claim 1, comprising different pieces of abrasive cloth with different grit sizes.

7. A sanding device according to claim 1, wherein a piece of abrasive paper comprises a sandwich of two or more layers of abrasive paper.

8. A sanding device according to claim 1, wherein several layers of bristles are provided behind a piece of abrasive paper.

9. A sanding device according to claim 1, wherein said core is made of a material comprising a filler material and a binding material.

10. A sanding device according to claim 8, wherein said filler material comprises a recycled material

11. A sanding device according to claim 8, wherein said filler material comprises paper.

12. A sanding device according to claim 8, wherein said filler material comprises wood fibers.

13. A sanding device according to claim 1, wherein said core is a cylindrical core, and said plurality of bristles and said pieces of abrasive cloth extend substantially radially from said surface of said cylindrical core.

14. A sanding device according to claim 1, wherein said core is a disc-shaped core, and said surface is a top surface of said disc, and said plurality of bristles and said pieces of abrasive cloth extend in a direction perpendicular to said top surface of said disc.

15. A sanding device according to claim 1, wherein said core is solid.