Sanding apparatus

Abstract: A sanding apparatus (1) has a sanding platen (2) to which motion is applied. The platen (2) has a flat surface (9) to which an abrasive sheet (22) is applied. The peripheral edge (3) of the platen (2) has a point (4) which can be used for detailed sanding. The surface (9) has a detachable portion (14) adjacent the point (4). The detachable portion (14) can be removed from the remainder of the platen (2) and rotated through 180°. The abrasive sheet (22) can have an area corresponding to the detachable portion (14) of the surface (9) which is removable from the remainder of the abrasive sheet (22) by means of a perforated line (24).

Description: This invention relates to a sanding apparatus, particularly a sanding apparatus with a detail sanding point. Sanding apparatus are known which have platens with a body on which is mounted a foam pad which has a surface to which abrasive sanding sheets are attached. An orbital or random motion is applied to the platen by a central drive from a motor. The platen moves in relation to a head of the apparatus. The platen body and the foam pad can be held against the surface to be sanded and the motion applied to the platen results in a sanding of the surface. A carrier layer can be disposed between the platen body, which is generally formed of a hard plastics material, and the foam pad. The foam pad can be attached to the carrier layer by means of a Velcro (registered trade mark) attachment means. The term platen is used herein to denote the combination of the platen body and foam pad and any intermediate layer. The platens can be of varying shapes, known examples include circular and rectangular platens. Sanding apparatus suitable for detailed sanding have platens which are generally triangular in shape with outwardly curved edges. Iron shaped platens have also been developed in which a single point tip is provided for accessing corners and providing detailed sanding whilst a large surface is provided for general flat sanding, as is the case of the one disclosed by DE-U-94 10 754. Sanding platens with pointed tips often result in the tip of the foam pad becoming worn due to the sanding platen being used at an angle and thereby wearing the foam at the tip of the foam pad. According to the present invention there is provided a sanding apparatus comprising a platen to which motion is applied, the platen having a surface to which an abrasive sheet can be applied, the peripheral edge of the platen having a tip for detailed sanding, wherein the surface has a portion including the tip of the surface to which the abrasive sheet can be applied which is detachable from the remainder of the platen. Preferably, the platen is formed of a base layer, a carrier layer and a surface layer. The surface layer may be formed of a foam material. Preferably, the detachable portion is in the shape of a parallelogram with two adjacent sides of the parallelogram forming the tip of the peripheral edge of the platen. Most preferably, the parallelogram has equal sides. The sides of the parallelogram may be slightly curved outwardly. The detachable portion may be attached to the platen by means of a nut and bolt attachment. Alternatively, the detachable portion may be attached to the platen by Velcro attachment means. Preferably, the detachable portion can be rotated through 180° such that the tip at the peripheral edge of the platen is changed. An abrasive sheet can be attached to the surface by means of a Velcro attachment means. Preferably, the abrasive sheet has a corresponding detachable portion which is defined by a perforated line. A preferred embodiment of a sanding apparatus in accordance with the present invention is now described by means of example only, with reference to the accompanying drawings, in which: Figure 1 is an exploded perspective view of the sanding apparatus; and Figure 2 is a perspective view of the assembled sanding apparatus of Figure 1 with an abrasive sheet shown separately. Referring to the drawings, a sanding apparatus 1 has a platen 2 with a base layer 11, a carrier layer 12 and a foam surface layer 10. The sanding platen 2 has a peripheral edge 3 with a tip 4 forming an iron-shape surface 9 of the platen 2. The tip 4 is used for sanding corners and other detailed areas. Motion is applied to the sanding platen 2 by a motor through a central drive 6. Location holes 8 restrict the motion of the sanding platen 2 to a random, non-rotating motion. An abrasive sheet 22 is applied to the surface 9 of the surface layer 10. The abrasive sheet 22 can be attached to the surface 9 by means of a Velcro attachment. A Velcro attachment enables the abrasive sheet 22 to be applied to an irregular shape of surface 9. The underside 23 of the abrasive sheet 22 has a first Velcro surface which is attachable to a second Velcro surface provided on the surface 9 of the surface layer 10. A portion 14 of the foam surface layer 10 adjacent to the detail tip 4 of the peripheral edge 3 is detachable from the remainder of the sanding platen 2. The detachable portion 14 can be loosened or completely detached from the sanding platen 2 and rotated through 180°, or even replaced, as the edges 28, 30 on either side of the tip 4 become worn. The detachable portion 14 is an equal sided parallelogram with two first sides 28, 30 which form an acute angle 36 at the tip 4. Second sides 32, 34 form the opposing acute angle 38. The two edges 40, 42 of the remaining portion of the foam surface layer 10 of the sanding platen 2, which correspond to the second edges 32, 34 of the detachable portion 14, form a corresponding acute angle on the surface 9. The two angled sides 40, 42 of the remaining portion of the foam surface layer 10 provide a wedge which prevents excessive movement of the detachable portion 14 during the sanding movement of the platen 2. The detachable portion 14 can be attached to the sanding platen 2 by an attachment means in the form of a nut 20 and bolt 18. The bolt 18 is inserted through the sanding platen 2 from the opposite side to the surface 9. The bolt 18 passes through a hole 17 in the base layer 11 of the sanding platen 2. The bolt 18 also passes through a portion 16 of the carrier layer 12 and a nut 20 is provided on the far side of this layer 12. The detachable portion 14 of the foam surface layer 10 is attached to the carrier portion 16. The detachable portion 14 of the foam surface layer 10 has a recess 15 in which the nut 20 is contained. In use, an abrasive sheet 22 is applied to the surface 9 of the sanding platen 2, the motor can be started and the sanding operation commenced. During sanding, the platen 2 is often tilted with excessive sanding taking place at the tip 4. The tip 4 of the foam surface layer 10 of the sanding platen 2 therefore becomes worn. The detachable portion 14 can be detached from the sanding platen 2, after first breaking the perforated line 24 on the abrasive sheet 22. The detachable portion 14 can be rotated through 180° thereby providing a new unworn tip. The detachable portion 14 is reattached to the sanding platen 2 and sanding can be recommenced. As an alternative to the bolt attachment means, the detachable portion 14 can be attached to the sanding platen 2 by Velcro attachment means. In such an embodiment, the wedge shape of the sides 40, 42 which prevents movement of the detachable portion 14 is beneficial. The components of the detachable portion 14 can be replaced as these become worn, providing a longer life for the sanding apparatus. Modifications and improvements can be made to the above without departing from the scope of the present invention.

Claims: A sanding apparatus (1) comprising a platen (2) to which motion is applied, the platen (2) having a surface to which an abrasive sheet can be applied, the peripheral edge of the surface having a tip (4) for detailed sanding, characterized by the platen (2) having a portion (14) including the tip (4) of the surface to which the abrasive sheet can be applied which is detachable from the remainder of the platen (2). A sanding apparatus as claimed in claim 1, wherein the platen (2) is formed of a base layer, a carrier layer and a surface layer (10). A sanding apparatus as claimed in claim 2, wherein the surface layer (10) is formed of a foam material (10). A sanding apparatus as claimed in any one of the preceding claims, wherein the detachable portion (14) is in the shape of a parallelogram with two adjacent sides (28, 30) of the parallelogram forming the tip (4) of the peripheral edge of the platen (2). A sanding apparatus as claimed in claim 4, wherein the parallelogram has equal sides (28, 30, 32, 34). A sanding apparatus as claimed in claim 4 or 5, wherein the sides (28, 30, 32, 34) of the parallelogram are slightly curved outwardly. A sanding apparatus as claimed in any one of the preceding claims, wherein the detachable portion (14) may be attached to the platen by means of a nut (18) and bolt (20) attachment. A sanding apparatus as claimed in any one of claims 1 to 7, wherein the detachable portion (14) is attached to the platen by Velcro (registered trade mark) attachment means. A sanding apparatus as claimed in any one of the preceding claims, wherein the detachable portion (14) can be rotated through 180° such that the tip (4) at the peripheral edge of the surface is changed. A sanding apparatus as claimed in any one of the preceding claims, wherein an abrasive sheet (22) can be attached to the surface by means of a Velcro attachment means. A sanding apparatus as claimed in claim 10, wherein the abrasive sheet (22) has a corresponding detachable portion which is defined by a perforated line.

Inventors: COCKBURN ERIC, MARTIN MICHAEL, COCKBURN, ERIC, MARTIN, MICHAEL
Applicants: BLACK & DECKER INC, BLACK & DECKER INC.
Application year: 1996
Main classification: B24B23
IPC codes: B24D9, B24B23