The present invention relates generally to finishing devices, and more particularly to belt-sanders for sanding molded columns and other elongated members.
Columns used in housing construction serve both functional and aesthetic purposes. Functionally, columns are weight-bearing members that support the weight of a structure. Aesthetically, columns give structures an aesthetically pleasing and classical appearance. Most columns used in residential construction are made of wood or wood composites. Wood columns, however, are vulnerable to water damage and rot, and typically require a great deal of maintenance. Molded columns provide an alternative to wood columns. Molded columns also are not vulnerable to water damage or rot, and require much less maintenance than wood columns.
Molded columns are produced using a molding process. The molding process leaves a seam or ridge where the mold separates, which must be removed to provide a smooth outer surface. Typically, the seam line or ridge is removed by manually sanding the column. However, manual sanding of molded columns process is time consuming and labor intensive. The time and labor needed to sand the columns translates into higher costs and lower production.
The present invention relates to a sanding apparatus and method of smoothing the exterior surface of an elongated work piece, such as a column. The sanding apparatus comprises a support structure, a belt-sander having an abrasive surface on the belt, and a mounting bracket to movably mount the belt-sander to the support structure. In operation, a user moves the belt-sander along the length of the elongated work piece so that the abrasive surface removes unwanted material from the exterior surface of the work piece, such as a residual seam line left over from a molding process, for example.
The support structure comprises a pair of guide rails that suspend the belt-sander above the elongated work piece. One of the guide rails is disposed above the belt-sander, while the other of the guide rails is disposed to the rear of the belt-sander. The belt-sander movably mounts to the guide rails via a mounting bracket. In one embodiment, for example, the mounting bracket comprises a pair of hingedly attached plates. One of the plates fixedly attaches to the belt-sander, while the other of the plates includes a guide mechanism that movably mounts to the guide rails. The guide mechanism may be, for example, guide wheels that roll along the length of the guide rails. Moving the belt-sander along the guide rails allows a user to move the abrasive surface along the length of the elongated work piece.
The mounting bracket plates are hingedly attached with a hinge. The hinge allows the user to pivot the belt-sander between a first position and a second position to bring the abrasive surface of the belt-sander into and out of contact with the work piece. In one embodiment, for example, the user may raise and lower the belt-sander using a handle connected to the belt-sander or to the mounting bracket. In the first position, the abrasive surface of the belt-sander remains away from the work piece, and thus, does not contact the exterior surface of the elongated work piece. In the second position, the abrasive surface is in contact with the exterior surface of the elongated work piece. When the abrasive surface contacts the exterior surface of the work piece, it does so in a direction that is transverse to a longitudinal axis of the work piece.
The belt-sander includes a drive motor, and therefore, is generally a heavy object. Therefore, the mounting bracket may also include one or more counter-balancing members connected to the belt-sander to counter-balance the weight of the belt-sander. This arrangement facilitates the delicate and precise smoothing of the exterior surface of the work piece with the relatively heavy belt-sander by preventing the weight of the belt-sander from resting upon the work piece.
The present invention provides a sanding apparatus and method for finishing an elongated work piece to remove unwanted material from the exterior surface of the work piece. By way of example, a user may remove a seam line on an exterior surface of a molded column or post by sanding the seam line with a belt-sander. In the present invention, a belt-sander is movably mounted so that the belt is generally perpendicular to the longitudinal axis of the column and the belt sander moves longitudinally along the length of the column. To remove the seam line along the length of the column, the user simply brings the belt in contact with the surface of the columns and moves the belt-sander longitudinally along the column. Finishing the exterior surface in this manner is generally faster than sanding the seam line manually. In addition, the belt-sander generally conforms to the curvature of the column to prevent damaging the column.
Referring now to
The support structure 20 comprises a pair of guide rails 22, 24, which in the embodiment of
Support structure 20 includes a support frame comprising one or more vertical or horizontal members 26 to support the guide rails 22, 24. Alternatively, guide rails 22, 24 may be secured to a surrounding support structure, such as a ceiling and wall of a building (not shown). Support structure 20 supports the weight of belt-sander 30 away from the work piece 12, and allows a user to move the belt-sander 30 back and forth along a longitudinal axis of work piece 12 to finish the exterior surface of work piece 12.
Belt-sander 30 may comprise any conventional belt-sander known in the art. The belt sander 30 comprises a housing 32, a drive motor 34, and a belt 38 (see
Mounting bracket 40 movably mounts the belt sander 30 to the support structure 20 such that the belt 38 extends generally perpendicular to the longitudinal axis of the work piece, and such that the belt sander 30 moves longitudinally along the length of the column. In one embodiment, mounting bracket 40 comprises a pair of support plates 42, 44 pivotally connected with a hinge 46. A first support plate 42 includes guide mechanisms 50, 52, that movably mount the mounting bracket 40 to guide rails 22, 24, respectively. The second support plate 44 fixedly attaches to the belt-sander 30. Hinge 46 pivotally connects the first and second support plates 42, 44. Hinge 46 allows the belt sander 30 to move in a vertical plane between raised and lowered positions. The exemplary embodiment includes a single hinge 46, however, those skilled in the art will readily appreciate that more than one hinge 46 may be used to pivotally connect plates 42, 44.
The weight of the belt sander 30 causes the belt sander 30 to rotate downward about the axis of hinge 46. One or more counterbalance springs 48 are provided to counterbalance the weight of the belt sander 20. One end of each spring 48 is secured to the first support plate 42. The opposite end of each spring 48 is secured to the second support plate 44, or to the belt sander 20. The counterbalance springs 48 oppose the weight of the belt sander 30 so that the user can more easily raise and lower the belt-sander 30, and to keep the weight of the belt-sander 30 from bearing down too hard on the work piece 12.
The first and second guide mechanisms 50 and 52 engage the first and second guide rails 22, and 24 respectively. The guide mechanisms 50, 52 permit the user to move the heavy belt-sander 30 with little effort.
The first guide mechanism 50 suspends the belt sander 30 from guide rail 22. Guide mechanism 50 comprises four guide wheels 54 mounted to a carriage 51. The carriage suspends the belt sander 30 from the guide rail 22. The carriage 51 is connected to the first support plate by a pivot plate 53. The pivot plate 53 is connected at its top end to the carriage by a first pivot member 56, and at its lower end to the first support plate by a second pivot member 58. The additional pivot members 56, 58 provide further freedom of movement. In one embodiment, pivot members 56 and 58 comprise single bolts that connect the guide mechanism 50 to the mounting bracket 40. The pivot members 56, 58 allow the belt-sander 30 to pivot side-to-side and front-to-back with respect to the guide rail 22.
A second guide mechanism 52 helps maintain the belt sander 30 in a generally horizontal orientation. Guide mechanism 52 comprises a pair of guide wheels 55 mounted to the back of the first support plate 42 and in contact with guide rail 24. The weight of the belt sander 30 rotates the belt sander 30 about pivot member 58 so that the guide wheels 55 contact the guide rail 24. The guide wheels 55 roll along the guide rail 24 as the user moves the belt-sander 30 back and forth along the work piece 12.
In operation, the user raises and lowers the belt-sander 30 using a handle 36 fixedly attached to belt-sander 30 or mounting bracket 40. The column or other work piece is placed in a holder. The belt sander 30 is then lifted, moved into position above the work piece, and then lowered to bring the belt 38 into contact with the work piece. The tension of the counterbalance springs 48 prevents the belt sander 30 from bearing too hard on the column or work piece. The belt 38 extends transversely across the column or work piece. The motor 34 drives belt 38 so that the abrasive surface 39 removes unwanted matter (e.g., seam line 14) from the exterior of the work piece 12. The unwanted matter is vacuumed from the work area via discharge hose 18.
The counterbalance springs 48 and the ability of the belt 38 to conform to the curvature of the column facilitate the ability of the belt-sander 30 to follow the curvature of the work piece 12 during the sanding or finishing process. The curvature of columns is typically not uniform along the length. That is, the diameter of the work piece 12 will change slightly over the length of the work piece 12. Columns are typically designed to have a slight outward curvature near the center of the column, called entasis. This outward bulge provides an appearance of substantially parallel sides. The ability of the belt 38 to conform to the changing curvature of the column and the counterbalancing of the springs ensures that the belt 38 will produce a smooth finish without gouging or marring the surface.
The present invention may, of course, be carried out in other ways than those specifically set forth herein without departing from essential characteristics of the invention. The present embodiments are to be considered in all respects as illustrative and not restrictive, and all changes coming within the meaning and equivalency range of the appended claims are intended to be embraced therein.
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