Sander attachment for a drill

Abstract

The present invention is a sanding bit for use with an electric drill. The bit consists of an elongated member having a drill shaft formed on a first end of the member and a slot formed on a second end of the member. The slot is dimensioned and configured to receive an elongated strip of flexible sandpaper. The sandpaper strip is wound around the second end of the member to form a plurality of layers around the second end of the member. A barrel portion is formed on the second end of the member, the barrel portion having a greater cross-sectional diameter than the shaft. The slot may bifurcate the barrel member. The barrel portion may be cylindrical or conical.

Description

FIELD OF THE INVENTION

The invention relates generally to drill attachments for use in sanding.

BACKGROUND OF THE INVENTION

There are numerous attachments and bits for use with electric drills. In addition to drill bits, electric drills can be used with grinding, cutting and sanding attachments. Drill bits which are designed for use as sanders are well known in the market. These sanding attachments generally come in two different forms. The first form consists of a circular pad mounted to a drill shaft. The drill shaft is inserted into the chuck of the drill and a circular piece of sandpaper is attached to the circular pad. The sandpaper is usually attached to the pad by means of either an adhesive or by means of a recessed flanged bolt at the center of the pad. When the drill is activated, the circular pad spins allowing the user to sand down an item by applying the sandpaper covered pad to the item. After extensive use, the grit on the sandpaper will either wear away or become clogged and will have to be replaced. This type of sanding device is very popular; however, it can only be used on large flat surfaces because of the size of the circular pad.

Another common sander attachment for drills consists of a cylindrical abrasive stone coaxially attached to a drill shaft. The drill shaft is attached to the chuck of the drill before use. When the drill is activated, the cylindrical abrasive stone spins about its axis and can be used to sand or grind. This type of sanding attachment is also popular and is suitable for use in tight corners. The abrasive stones come in a variety of different grits, thereby allowing the user to change from one abrasive stone to another as required. Once the grit on the surface of the stone wears off, the stone must be replaced. Unfortunately, these stones have a relatively small surface area, which in turn means that they wear out relatively quickly. An improved sanding attachment which is more durable and less expensive than a traditional cylindrical grinding stone would be more extensively used in the market.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a sanding bit for use with an electric drill. The bit consists of an elongated member having a drill shaft formed on a first end of the member and a slot formed on a second end of the member. The slot is dimensioned and configured to receive an elongated strip of flexible sandpaper. The sandpaper strip is wound around the second end of the member to form a plurality of layers around the second end of the member.

With the foregoing in view, and other advantages as will become apparent to those skilled in the art to which this invention relates as this specification proceeds, the invention is herein described by reference to the accompanying drawings forming a part hereof, which includes a description of the preferred typical embodiment of the principles of the present invention.

DESCRIPTION OF THE DRAWINGS

FIG. 1. is a perspective view of a sander attachment made in accordance with the invention.

FIG. 2. is a top view of a strip of sandpaper for use with the invention.

FIG. 3. is a side view of the sander attachment shown in FIG. 1 in combination with an electric drill.

FIG. 4. is an end view of the sander attachment made in accordance with the invention.

FIG. 5. is an end view of the sander attachment with a strip of sandpaper being attached thereto.

FIG. 6. is an end view of the sander attachment with a strip of sandpaper wound about the attachment.

FIG. 7a. is a perspective view of the preferred embodiment of the present invention.

FIG. 7b. is a perspective view of another embodiment of the present invention.

FIG. 7c. is a perspective view of another embodiment of the present invention.

In the drawings like characters of reference indicate corresponding parts in the different figures.

DETAILED DESCRIPTION OF THE INVENTION

Referring firstly to FIGS. 1, 2 and 3, the sander attachment, shown generally as item 10 consists of a barrel member 12 coaxially mounted to a drill shaft 14. Shaft 14 is dimensioned and configured to releasably mount to chuck 16 of electric drill 18. Barrel 12 has slot 20 which bifurcates the barrel. Slot 20 is dimensioned and configured to receive elongated sandpaper strip 22. Sandpaper strip 22 is preferably rectangular and has ends 24 and 26 and has abrasive surface 28. Sandpaper strip 22 is suitably flexible to permit it to be wound around barrel 12. Slot 20 is dimensioned and configured to snugly receive end 24 of sandpaper strip 22. Sandpaper strip 22 is wound around barrel 12 with abrasive side 28 oriented away from the barrel member. Barrel member 12 and drill shaft 14 are preferably made from a strong material such as steel or brass. Preferably, drill bit 10 may be made from a single piece of metal such that barrel 12 and shaft 14 are contiguous.

Referring now to FIGS. 4, 5 and 6, sandpaper strip 22 is wound around barrel 12 in a spiral as illustrated in FIGS. 5 and 6. End 24 is first inserted into slot 20 of barrel 12 and then strip 22 is wound around the barrel in a spiral with abrasive surface 28 oriented on the outside of the spiral. Preferably, strip 22 is tightly wound around the barrel to form at least three layers of sandpaper, namely layers 30, 32 and 34. Of course, the number of layers will be determined by the diameter of barrel 12 and the length of strip 22. When the sandpaper is fully wound onto the barrel, the finished bit can be attached to the drill's chuck (see FIG. 3). In operation, the bit should be rotated in the direction indicated by arrow 36 in order to ensure that the sandpaper remains tightly wound onto the barrel. Since the slot bifurcates barrel 12, the sandpaper strip can be positioned such that portion 25 of end 24 extends beyond the slot. The rest of the strip may be wound over portion 25 to ensure that the sandpaper is securely retained onto the barrel.

The present invention has several advantages over the prior art. Firstly, since the barrel portion acts as a holder for sandpaper and does not have any abrasive characteristics itself, the drill bit can be used for a variety of different sanding and grinding applications simply by changing the type of sandpaper wrapped around the barrel. Hence, where the sander is to be used to remove a large amount of material, a relatively coarse grade of sandpaper can be used. Where the application calls for finer work, a fine grained sandpaper or emery cloth may be used. Also, since the bit may be made from a single piece of ordinary steel or brass, the bit may be made very inexpensively. Most significantly, since the sandpaper forms a plurality of layers around the barrel, the bit can be used for an extended period of time before having to change the sandpaper.

As the bit is used, the outermost sandpaper layer is slowly worn away, exposing a fresh layer of sandpaper beneath. In the event that a very durable sandpaper is used, the outermost layers can simply be removed as they become worn down or clogged up. As the worn layers are removed, the underlaying fresh layer is exposed, permitting the sanding bit to be used for a longer period of time. When the last layer of sandpaper is worn away, a new strip can be easily added.

An alternate embodiment of the present invention is shown in FIG. 7b. Bit 40 consists of a conical barrel portion 42 coaxially mounted to a drill shaft 44. Barrel portion 42 has first end 49 and second end 48. Slot 46 bifurcates end 48. Barrel portion 42 tapers away from shaft 44 such that the cross-sectional diameter of end 48 is less than the cross-sectional diameter of end 49. As with the previous embodiment, an elongated strip of sandpaper is inserted into slot 46 and then wound around the barrel in a spiral fashion. Since barrel 42 is conical, the sandpaper may be wrapped around the barrel to form a flared horn as indicated in FIG. 8. This flared horn structure is relatively flexible, allowing to the user to apply more uniform and gentle pressure onto the surface of the item being worked with (not shown).

Another alternate embodiment of the present invention is shown in FIG. 7c. Bit 50 consists of a conical barrel portion 52 coaxially mounted to drill shaft 54. Barrel portion 52 has first end 59 and second end 58. Slot 56 bifurcates end 58. Barrel portion 52 tapers towards shaft 54 such that the cross-sectional diameter of end 58 is greater than the cross-sectional diameter of end 59. As with the previous embodiments, an elongated strip of sandpaper is inserted into slot 56 and then wound around the barrel in a spiral fashion. As in the previous embodiment, since barrel 52 is conical, the sandpaper may be wrapped around the barrel to form a flared horn as indicated in FIG. 9. This flared horn structure is relatively flexible, allowing to the user to apply more uniform and gentle pressure onto the surface of the item being worked with (not shown). The flared horn structure as shown in FIGS. 8 and 9 are suitable for sanding uneven surfaces.

A specific embodiment of the present invention has been disclosed; however, several variations of the disclosed embodiment could be envisioned as within the scope of this invention. It is to be understood that the present invention is not limited to the embodiments described above, but encompasses any and all embodiments within the scope of the following claims.

Claims

1. A sanding bit for use with an electric drill, said bit comprising:

a) a barrel body having opposite first and second ends and a longitudinal axis,

b) an elongated drill shaft coaxially mounted to the first end of the barrel body,

c) the barrel body having a slot passing through the second end of the barrel body,

d) a strip of sandpaper threaded through the slot and wound around the barrel body.

2. The sanding bit of claim 1 wherein the strip of sandpaper has an abrasive surface and wherein the sandpaper is wound around the body such that the abrasive surface of the sand paper is oriented away from the barrel body.

3. The sanding bit of claim 1 wherein the slot is dimensioned to snugly receive the strip of sandpaper.

4. The sanding bit of claim 2 wherein the sandpaper is wound around the barrel body in a spiral to form a plurality of sandpaper layers around the cylindrical member.

5. The sanding bit of claim 1 wherein the barrel body is cylindrical.

6. The sanding bit of claim 5 wherein the sandpaper has an abrasive surface and wherein the sandpaper is wound around the barrel body in a spiral to form a plurality of layers with the abrasive surface of the sand paper oriented away from the barrel body.

7. The sanding bit of claim 1 wherein the barrel body is conical and wherein the second end of the barrel body is broader than the first end of the barrel body.

8. The sanding bit of claim 7 wherein the sandpaper has an abrasive surface and wherein the sandpaper is wound around the barrel body in a spiral to form a plurality of layers with the abrasive surface of the sand paper oriented away from the barrel body.

9. The sanding bit of claim 1 wherein the barrel body is conical and wherein the first end of the barrel body is broader than the second end of the barrel body.

10. The sanding bit of claim 9 wherein the sandpaper has an abrasive surface and wherein the sandpaper is wound around the barrel body in a spiral to form a plurality of layers with the abrasive surface of the sand paper oriented away from the barrel body.

11. A sanding bit for use with an electric drill, said bit comprising an elongated member having a drill shaft formed on a first end of the member and a slot formed on a second end of the member, slot dimensioned and configured to receive an elongated strip of flexible sandpaper, the sandpaper strip being wound around the second end of the member to form a plurality of layers around the second end of the member.

12. The sanding bit of claim 11 wherein the slot bifurcates the second end of the member.

13. The sanding bit of claim 11 wherein the second end forms a barrel member, the barrel member and the drill shaft having cross-sectional diameters, the diameter of the barrel member being greater than that of the shaft.

14. The sanding bit of claim 13 wherein the barrel member is cylindrical.

15. The sanding bit of claim 13 wherein the barrel member is conical and wherein the conical barrel member tapers away from the drill shaft.

16. The sanding bit of claim 13 wherein the barrel member is conical and wherein the conical barrel member tapers towards the drill shaft.