Claims
- 1. A drum sander accessory for radial arm saws of the type having a vertical adjustable column supporting a horizontal saw arm which is parallel to a horizontal work table and having a motor with a drive shaft, comprising:
- (a) a sanding cylinder substantially parallel to and spaced above said work table, having an inside and outside, and having a first end proximate said vertical column and an opposite second end, the outside of said cylinder having an abrasive strip thereon and the inside of said cylinder having a central shaft extending therethrough and beyond each end of said sanding cylinder;
- (b) two vertical carriage legs attached to and extending above each end of said sanding cylinder, said vertical carriage legs each having an aperture to accommodate said central shaft;
- (c) a substantially horizontal carriage arm spaced above said sanding cylinder, having a first and second end corresponding to said first and second end on said sanding cylinder, connected on each end to said vertical carriage legs;
- (d) a clamp rigidly connected to said first end of said carriage arm which is clamped onto said vertical column for vertical adjustment and tightening of said sanding cylinder;
- (e) a driven pulley having a central bore through which said first end of said central shaft is inserted; and
- (f) an arbor drive pulley connected to said drive shaft of said radial arm saw and connected to said driven pulley by means of a belt, whereby said sanding cylinder is rotated and wood is sanded when inserted beneath said sanding cylinder.
- 2. A drum sander according to claim 1, wherein said sanding cylinder, carriage arm, carriage legs, and clamp are made of aluminum.
- 3. A drum sander according to claim 1, wherein the inside of said sanding cylinder has a plurality of spokes therein, said sanding cylinder being formed from an extrusion process.
- 4. A drum sander according to claim 1, wherein said clamp has a first end proximate said carriage arm and an opposite second end, comprising:
- (a) a clamp support piece integral with said carriage arm, said clamp support piece having a substantially semicircular clamping surface disposed porximate said second end;
- (b) a clamp screw inserted through said threaded bore, one end of said clamp screw having a clamp screw handle; and
- (c) a clamp jaw having a substantially semicircular clamping surface oppositely facing said clamping surface of said clamp support piece, said first end of said clamp jaw having a transverse threaded bore through which said clamp screw is inserted, wherein the rotation of said clamp screw handle causes said clamp jaw to move relative to said clamp support piece to allow vertical adjustment and tightening of said clamp and attached drum sander.
- 5. A drum sander according to claim 1, wherein said sanding cylinder is about twenty-two (22) inches in length.
- 6. A drum sander according to claim 1, further comprising a substantially semicylindrical dust collector, each longitudinal end of said dust collector having tabs which attach to each vertical carriage leg, said dust cover having a longitudinal vacuum slot which attaches to a vacuum hose proximate said vertical support, said dust collector covering the upper portion of said sanding cylinder.
- 7. A drum sander according to claim 6, wherein said dust collector is made of plastic.
- 8. A drum sander according to claim 6, wherein said dust collector is made of aluminum.
- 9. A drum sander accessory for radial arm saws of the type having a vertical adjustable column supporting a horizontal saw arm which is parallel to a horizontal work table and having a motor with a drive shaft, comprising:
- (a) a sanding cylinder substantially parallel to and spaced above said work table, having a first end proximate said vertical colummn of said radial arm saw and an opposite second end, said cylinder having an abrasive strip thereon and a central shaft extending therethrough and beyond each end of said sanding cylinder;
- (b) a U-shaped carrier bracket having a first and second vertical end corresponding to said first and second ends on said sanding cylinder, with an integral horizontal member between said vertical ends, each vertical end of said bracket having an aperture to accommodate said central shaft;
- (c) a column support rigidly attached to said work table and connected to said second vertical end of said carrier bracket for support thereof, said column support having an annular collar with a locking knob and set screw which surrounds said column support, whereby said second end of said sanding cylinder can be adjusted vertically and tightened into the desired position by said locking knob;
- (d) a sleeve member connected to said first end of said carrier bracket proximate said horizontal member which is clamped onto said vertical adjustable saw column for vertical adjustment of said first end of said sanding cylinder;
- (e) a driven pulley having a central bore through which said frist end of said central shaft is inserted; and
- (f) an arbor drive pulley connected to said drive shaft of said radial arm saw and connected to said driven pulley by means of a belt, whereby said sanding cylinder is rotated and wood is sanded when inserted beneath said sanding cylinder.
- 10. The drum sander according to claim 9, wherein said column support is attached to said work table by means of a plate, one end of which is rigidly secured to the bottom of said column support, the opposite end of said plate being fastened to the bottom of said work table.
- 11. A drum sander according to claim 9, wherein said sleeve member comprises two, facingly disposed half-cylindrical pieces interconnected by a bolt and an intermediate connector piece having a plurality of bolts, which is disposed between and connects said first end of said carrier bracket to said sleeve member, whereby said carrier bracket can be removed from said saw and said sleeve member and connector piece remain attached thereto.
- 12. A drum sander according to claim 9, wherein said sanding cylinder, said carrier bracket, and said sleeve member are made of aluminum.
- 13. An attachment mechanism for attaching sandpaper to a sanding cylinder, comprising:
- (a) a sandpaper feed groove formed in an end of said sanding cylinder parallel to the axis of said sanding cylinder;
- (b) a rivet disposed proximate said sandpaper feed groove having a rivet head on said inside of said sanding cylinder;
- (c) a slide fastener having a longitudinal slot, held against said inside wall of said sanding cylinder by said rivet head, said longitudinal slot being substantially perpendicular to the axis of said sanding cylinder, wherein said slide fastener slides along said rivet head for the length of said slot, so that when said rivet head is at one end of said slot, said slide fastener covers said sandpaper feed groove and is in its holding position, and when said rivet head is at the opposite end of said slot, said slide fastener does not cover said sandpaper feed groove and is in its release position.
- 14. The attachment mechanism according to claim 13, wherein said slide fastener is made of plastic.
- 15. The attachment mechanism according to claim 13, further comprising:
- (a) a switch integral with said slide fastener and extending therefrom at a substantially perpendicular angle to facilitate movement of said slide fastener by the user; and
- (b) a guide positioned along one longitudinal edge of said slide fastener and integral therewith, said guide extending along the edge of said sanding cylinder to maintain proper position of said slide fastener.
- 16. A drum sander accessory for radial arm saws of the type having a vertical adjustable column supporting a horizontal saw arm which is parallel to a horizontal work table and having a motor with a drive shaft, comprising:
- (a) an aluminum sanding cylinder substantially parallel to and spaced above said work table, having an inside and outside, and having a first end proximate said vertical column and an opposite second end, the outside of said cylinder having an abrasive sandpaper strip spiralled thereon and the inside of said cylinder having a central shaft extending therethrough and beyond each end of said sanding cylinder;
- (b) two aluminum vertical carriage legs attached to and extending above each end of said sanding cylinder, said vertical carriage legs each having an aperture to accommodate said central shaft;
- (c) an aluminum, substantially horizontal carriage arm spaced above said sanding cylinder, having a first and second end corresponding to said first and second end on said sanding cylinder, connected on each end to said vertical carriage legs;
- (d) a clamp rigidly connected to said carriage arm and clamped onto said vertical column for vertical adjustment and tightening of said sanding cylinder, having a first end proximate said carriage arm and an opposite second end, comprising:
- (i) a clamp support piece integral with said carriage arm, said clamp support piece having a substantially semicircular clamping surface disposed proximate said second end;
- (ii) a clamp screw having a clamp screw handle; and
- (iii) a clamp jaw having a substantially semicircular clamping surface oppositely facing said clamping surface of said clamp support piece, said first end of said clamp jaw having a transverse threaded bore through which said clamp screw is inserted, wherein the rotation of said clamp screw handle causes said clamp jaw to move relative to said clamp support piece to allow vertical adjustment and tightening of said clamp and attached drum sander;
- (e) an attachment mechanism for attaching sandpaper to said sanding cylinder, comprising:
- (i) a sandpaper feed groove formed in an end of said sanding cylinder parallel to the axis of said sanding cylinder;
- (ii) a rivet disposes proximate said sandpaper feed groove having a rivet head on said inside of said sanding cylinder;
- (iii) a slide fastener having a longitudinal slot, held against said inside wall of said sanding cylinder by said rivet head, said longitudinal slot being substantially perpendicular to the axis of said sanding cylinder, wherein said slide fastener slides along said rivet head for the length of said slot, so that when said rivet head is at one end of said slot, said slide fastener covers said sandpaper feed groove and is in its holding position, and when said rivet head is at the opposite end of said slot, said slide fastener does not cover said sandpaper feed groove and is in its release position;
- (f) a driven pulley having a central bore through which said first end of said central shaft is inserted; and
- (g) an arbor drive pulley connected to said drive shaft of said radial arm saw and connected to said driven pulley by means of a belt, whereby said sanding cylinder is rotated and wood is sanded when inserted beneath said sanding cylinder.
BACKGROUND OF THE INVENTION
This is a continuation-in-part application of U.S. patent application Ser. No. 778,712, filed Sept. 23, 1985 and now abandoned.
This invention pertains to a drum sander accessory for woodworking and more particularly to such a device which can be adapted for use with radial arm type saws.
Sanding machines are currently available, but they are expensive and require significant space. Also, the attachment of the sandpaper to a conventional sanding machine is difficult and time-consuming, because either adhesive or tape must be used. This is particularly important when the operator must change the sandpaper several times during a single woodworking project to produce various degrees of abrasion or coarseness.
Further, the adjustment of the sanding cylinder relative to the work table is often complex when the table, rather than the sanding cylinder, must be adjusted vertically an even, uniform distance. The table adjustment is typically accomplished by means of a screw and sprocket at each corner of the table, with the screws being interconnected with a chain. This assembly tends to be relatively expensive and complicated. In addition, conventional drum sanders usually contain a hollow, metal shaft in the center with closed metal ends. The varying degree of metal along the length of the sanding cylinder, and the high heats under which the sander is operated, cause the cylinder to warp after extended use, instead of maintaining a straight horizontal configuration. Finally, a conventional sanding machine is able to sand only a relatively narrow piece of wood, because of obstructions or supports on each end of the sanding cylinder.
Radial arm saws have become commonplace in both commercial and home woodworking workshops. It is therefore, desirable to provide a drum sander which is convenient to operate, able to sand wide pieces of wood, and able to be attached to radial arm saws.
One object of the invention is to provide a sanding attachment that is simple, durable, and economical.
Another object of the invention is to provide a quick, convenient and secure attachment of the sandpaper to the sanding cylinder. A slide fastener is provided for each end of the sanding cylinder to carry out this objective.
Another object of the invention is to provide a sanding cylinder with a constant rate of thermal expansion throughout its length, so that the sanding drum maintains a straight horizontal configuration and does not warp or sag in the central portion after extended use. This objective is accomplished by forming the sanding cylinder from extrusion processes so that there is a constant amount of metal throughout the length of the sanding cylinder.
A further object of the invention is to provide a sanding cylinder which is supported on only one of its ends above the work table. This design feature enables the wood to be inserted without being hindered by a support at both ends, and thereby enables a much wider piece of wood to be sanded.
Another object of the invention is to provide a sanding device that can attach to an ordinary radial arm saw. Consequently, the invention utilizes the features of a radial arm saw in order to provide the sanding device of the present invention with a power source, a work table, and an adjustable vertical column.
A further object of the invention is to provide a device that is readily adjustable to provide parallel alignment of the sanding cylinder relative to the work table. The device is lightweight and is provided with a convenient clamp attachment for adjustment and removal purposes.
These and other objects of the invention will become apparent from a consideration of the following specification and accompanying drawings which form a part of this application.
US Referenced Citations (4)
Continuation in Parts (1)
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778712 |
Sep 1985 |
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Patent Grant
4720940
