TECHNICAL FIELD OF THE INVENTION

[0001] The present invention generally relates to a device for sanding, removing rough edges and leveling surfaces. More specifically, the invention is a handheld, reusable blade holder.

BACKGROUND

[0002] Little progress has been made in the art and technology of preparing surfaces by sanding. Sanding is defined as converting a surface from rough to smooth with products that range from rough to relatively smooth, starting with the roughest grade of sandpaper. Sanding also can be used to roughen very shiny surfaces to better hold paint.

[0003] Sandpaper has been around for hundreds of years. An early version featured bonded crushed shells, sand, etc., stuck to parchment with natural gum. Later, glass particles were used. Initially "dry" sandpaper was provided bonded with water-soluble glue and has been widely used because it is inexpensive. In the past century, a sandpaper with a waterproof backing was invented to be used with water to wash sanded-off particles from automobiles.

[0004] Sanding is important in a wide variety of industries, including automotive/vehicular, building (both new and remodeling), aeronautics, furniture (new and refinishing), as well as light industrial and heavy industrial industries. Because sanding creates very small particles, some industries are regulated to avoid inhalation by workers.

[0005] In some cases, initial sanding can be performed with an electrically powered sander. However, in uses where a fine finish is required, hand sanding is widely required. A very smooth finish is required to decrease friction and drag of vehicles, including autos, trucks and airborne craft of all types. A very smooth finish is also required for aesthetics in homes and furniture. Hand sanding is still a labor-intensive task. For example, many hours and many sheets of sandpaper are required to prepare a car body surface for repainting.

SUMMARY OF INVENTION

[0006] In one embodiment, the inventive sanding blade includes a blade with two ends and a top and a bottom surface, the bottom surface having teeth, the teeth being so spaced and dimensioned as to provide a variable sanding surface; and a hardened material to hold in place the top surface of the blade with the teeth protruding from the hardened material.

[0007] In other embodiments, the blade is bent and the two ends are attached. The blade ends can be attached with a bolt to form a circle. The ends can be attached with hot metal solder and the blade assumes a tear drop shape. The blade can be molded in the tear drop shape. The sanding blade can have a flat surface on top. The hardened material can be car body bond into which the top surface of the blade was placed when it was soft. The blade holder's upper surface can be sized and rounded for handling by a professional sander. The blade holder can have a perimeter that is round, square or oval. The blade holder' s perimeter extends outward from the blade providing self-leveling. The blade holder further has a skirt around the perimeter. The blade holder skirt extends from the perimeter to be even with the teeth of the blade. The blade holder has holes through the hardened material suitable for attachment to a vacuum hose. The blade holder holes are positioned inside and outside the blade.

BRIEF DESCRIPTION OF THE DRAWINGS [0008] FIG. 1 illustrates an embodiment of the bottom surface of the blade holder.

[0009] FIG. 2 is a close up of FIG. 1 , showing more detail of the blade teeth.

[0010] FIG. 3 shows a sanding blade with a dotted line for removal of hardened material permitting the blade holder access to corners.

[0011] FIG. 4 shows the bottom surface of the blade holder with exemplary holes to draw sanded particles up into the tool to be emptied into the vacuum hose.

[0012] FIGS. 5A and 5B show the blade holder with a removable handle. FIG. 5A is a profile view of the removable handle. FIG. 5B is a lateral view of the removable handle.

[0013] FIG. 6 shows a different design of the blade holder with a coarse blade positioned close to the edge of its holder.

[0014] FIG. 7 shows a different design of the blade holder with a fine blade positioned close to the edge of its holder.

DETAILED DESCRIPTION

[0015] I have been involved in restoring automobiles and in wood working for decades. One of the most time-consuming tasks of either of these activities is sanding. Sanding is also an important part of residential and commercial dry wall installation and painting and repainting. Sanding also requires large quantities of materials; each piece of sandpaper is used for only a few minutes and only a part of each piece actually contacts the object to be sanded. Sand (or other abrasives) accumulates on the floor of the activity, abrading the floor; all the sandpaper is discarded because none can be reused. All of this contributes to sandpaper being a major cost for small restoration and woodworking shops, estimated at $800 per employee per month. Moreover, the shop pays for the discarded sandpaper to be hauled away and dumped in a landfill. I have thought about alternatives and searched far and wide but have not located any alternative.

[0016] Short of sandpaper one day, I picked up a hack saw blade and toyed with the idea of using it for removing hardened filler from a car body. I came up with the idea of connecting the two ends of the hacksaw blade (each usually equipped with a hole to attach to the hacksaw holder) with a bolt to form a circle. I mixed car body filler with some hardening agent, continuing to mix it until the mixture had a uniform color. Car body filler was useful because it is not only hard and rapidly cured, but it also bonds well to the metal of the blade. I next invented a new use for a large used cap by placing it topside down on a surface and filling it almost to its edge with the mixed, still soft car body filler. While the filler in the cap was still soft, I inserted the non-toothed edge of the fastened hacksaw blade into the filler only until the sharp teeth protruded with a couple of extra millimeters. See FIG. 1. 1 let that harden and then returned to my project of removing excess body filler with my rudimentary tool.

[0017] Besides car body filler, I have found that other hard materials can be used and may include metal, polyester, fiberglass, epoxy resin, casting resin and various other resins. Many other similarly hardening resins are believed to be useful herein. In fact, I have found that any holder of the blade that is comfortable in the hand can be used.

[0018] The hacksaw blade had long, in-line teeth that are approximately parallel. The handled blade was immediately useful for initial removal of newly applied car body filler. I grasped the handled blade so that the heel of my palm rested on the side opposite the hacksaw attachment; when I pressed hard on the heel of my palm and less on the opposite side, filler removal went quickly. Later and more intensive use has shown that the tool does not actually require downward pressure ("into" the filler), just lateral pressure to move along the surface and literally shave off excess filler. [0019] As an added benefit, when I simply rotated the tool 20 to 50 degrees, I continued to remove filler with the same tool, resulting in both angles of rotation removing filler with increasing fineness to obtain a smoother and smoother finish. Moreover, I found that applying less pressure permitted even finer sanding. FIG. 2 shows details of the teeth arrangement that afforded the new function.

[0020] The blade teeth are quite sharp when new. With use, the blade teeth may wear down gradually; however, even the worn teeth are still effective in removing uneven product and producing a smoother surface. Excited as I was with this breakthrough, I knew my new blade holder needed more work before I could share it with professionals who spend many hours a day sanding. Alternately, the blade can have different configurations, with teeth sized, positioned and angled variably. The blade surface can include but is not limited to a

TEFLON® finish, carbide composition and dusting of the blade with diamonds and other hard materials.

[0021] FIG. 1 shows the under or working side of the oval-sided blade holder 10. Most of the exposed surface is a hardened material 20 that encases much of the blade 30. The two ends of the blade have been affixed in a corner 40. Opposite the corner 40 is the roughest part of the sanding blade 30 because there is more space between the teeth when the blade holder 10 is properly grasped. Tilting the blade holder to one side or the other to use the blade at an angle of 20-45 degrees utilizes the blade 30 so that the teeth are closer together for smoother finishing sanding.

[0022] The sanding blade 30 has been constructed from a hacksaw blade that has several advantages. FIG. 2 shows details of the teeth of the hacksaw blade with rough and long teeth. Though the teeth are the same for the length of the hacksaw blade, using the rounded blade at an angle makes the teeth closer together to perform smoother and finer sanding. Applying force differently to the blade holder enables the professional removing product to efficiently use my blade holder in the hand and obtain both rough and finer finishes.

[0023] Notably, use of my new blade holder eliminates a whole series of normal sanding activities:

[0024] obtaining a sheet of the appropriate rough sandpaper,

[0025] attaching rough sandpaper to the hand-held device before the professional starts sanding,

[0026] obtaining a finer sandpaper, [0027] removing the rough sandpaper, and

[0028] replacing it with the finer sandpaper in the hand-held device before sanding even begins again.

[0029] This routine set of activities can take several minutes, as opposed to the few seconds needed to rotate my blade holder in the palm of the hand. Multiply this by a hundred times a day, and it is clear that the personnel savings are considerable. Owners of car body shops who have been instructed in the use of the blade holder have estimated they could increase shop throughput by at least 10% with no significant increase in outlay, labor or overhead.

[0030] While FIGS. 1 and 2 show the blade holder 10 with an oval outline. The sides can be any shape, including but not limited to square, rectangular, and round. As shown in FIG. 3, which shows the blade holder 10 from the inside looking down on the blade 30. One portion of the edge of the blade holder 10 can have a tapered V 70 that is close to the sanding blade 30, as shown with dotted lines. In this view, the teeth 60 of the blade 30 are farther away. This configuration enables the professional to sand in corners that could not be reached with the blade holder 10 as shown in FIG. 1. [0031] My next breakthrough came when I created a handle for the blade holder to provide an easy-to-use, but specialized holder because people perform sanding for hours at a time!

[0032] Because not all objects to be sanded are within arm's length, I also invented a holder to sand at more distance from the professional's hand.

[0033] In use, my new blade holder has lasted many times longer than sandpaper. I have used the new blade holder extensively and have estimated that it replaces at least $450 worth of sandpaper during its useful life.

[0034] In dry wall use, I have found my blade holder to be as fast as an electric sander, which is used initially to prepare the surface for painting. In new construction, dry wall goes up and must be sanded even before the electricity is turn on. Therefore, an electric sander cannot be used on these extensive dry wall surfaces and my blade holder operates nearly as fast, without the need for electricity. Applying a fluorescent paint or tape to the exterior makes my product even more beneficial in new construction because it is easier to find in unlit rooms.

[0035] Another important feature is that my new blade holder is very effective at sanding gummy body filler that would ordinarily destroy sandpaper whose crevices quickly fill with soft body filler and interfere with sanding. Unlike sandpaper that merely removes car body filler, I have found that my blade holder also fills in voids that are untouched or even accentuated by sandpaper. With my new blade holder, I can wash it with soapy water or other solvents and shake it dry or blot it dry so it is ready for continued use.

[0036] Moreover, I consider my new blade holder to be a three-in-one tool, because it effectively sands at the equivalent of sandpaper labeled rough, and upon tilting 80 grit and 120 grit. In addition, my design of a wide blade holder enables more level work, which is essential to keeping surfaces even; an inconvenient block would need to be coated with sandpaper.

[0037] I can cover the whole gamut of sanding products from coarse to very fine, etc. For example, I can offer one blade holder with the equivalent of 40-120 grits, another with the equivalent of 130-240 grits and another with the equivalent of 250-420 grits. When that set of blade holders is provided, I can also provide color-coding, such as on the handles, so that they can be easily distinguished at a glance and at a distance. For example, I can provide orange handles for 40-120 grits, green handles for 130-240 grits and purple handles for 250- 420 grits

[0038] In yet another embodiment, I provide the blade holder with the grit values imprinted and/or embedded in the bottom of the blade holder, which is particularly helpful for colorblind workers. This contrasts with sandpaper which is difficult to identify after the first piece is torn off and no more printed identification appears on the back. Trying to discern different but similar grits by feel is difficult when the professional works his way through sandpapers with close grit numbers; the professional often discards the unidentified piece and obtains a new labeled sheet, further adding to sandpaper waste.

[0039] We have made prototypes of molded plastic to hold the blade. Because of concerns that the plastic might not adequately retain the blade after extended use (not yet observed), we also modified the design to incorporate into the molten plastic a metal grid (not shown) to stabilize the blade.

[0040] In addition, I show in FIG. 4 a partial view of a soft skirt 80 for the blade holder 10. Such a skirt 80 limits abrasions to adjacent walls and serves other uses. In one embodiment, the skirt 80 affords a furry edge around the blade holder perimeter and can be fabricated of polystyrene, nylon, microfiber, sheep hide or other materials having similar properties. Preferred are resilient materials such as polystyrene. Alternately, a resilient surface of rubberlike or soft plastic can be applied to the edge of the blade holder 10.

[0041] I consider ways to deal with workplace rules that require vacuuming of sanding particles to avoid pulmonary problems in personnel who sand. For the most part my blade tool does not create the type of particles that typically result from sanding; my tool actually carves, as can be seen from the small curls of car body filler shaved off the car with the roughest grade of my tool. In yet another embodiment, I attach a perimeter skirt 80 to be long enough to touch the surface to be abraded. This skirt 80 keeps the blade-carved shavings near the blade holder and away from the professional's nose and lungs.

[0042] Optionally, I can affix a vacuum hose to the blade holder 10. For example, I can affix the hose to the edge of the blade holder 10 (at the location of the skirt 80) or provide at least one canal through the blade holder, so that a vacuum hose end (not shown) resides on the blade holder 10. FIG. 4 shows the bottom of the blade holder 10 with an exemplary pattern of numerous holes 90 to draw fine particles into the blade holder and the vacuum hose. Note that the holes 90 appear both inside the blade circle and on the outsides, the better to catch particles regardless of the direction of movement of the blade holder 10. A sufficiently powerful vacuum pulls particles outside the skirt 80 into the skirt 80 and the holes 90.

[0043] For more convenient use of the vacuum, the vacuum hose is preferably equipped with a means for maintaining hose contact with the professional sander's arm. Such a means includes but is not limited to a clip to a shirt and an arm-encircling band attached with VELCRO®, a buckle, etc. For convenient movement around a shop, the vacuum blower unit is carried on the professional sander's back in a backpack. Preferably such a vacuum is battery powered. [0044] Professional sanders also choose "wet" or "dry" sandpaper, depending on the job. Thus, a shop needs to maintain inventories of both sets of sandpaper; if the wet or dry sandpaper is missing, that impedes the workflow. "Dry" sandpaper has the cheaper water- based adhesive to hold the sand or other particles. "Wet" sandpaper has a waterproof adhesive to enable sanding of wet surfaces where sanding would clog the spaces among the sand particles spaces of dry sandpaper that either gums up or disintegrates upon exposure to water. In contrast, our new sanding blade can be used in wet or dry conditions.

[0045] I have found my blade holder to be self-cleaning, in that when I move it back and forth, shavings and other material easily come off. I simply rinse it off between uses or as abraded material accumulates around the blade. Of course, a TEFLON® coating eases cleaning, too. Even if personnel do not regularly dry off the new blade holder and the blade starts to rust, rust too can help abrade surfaces and aids to product removal activity.

Historically, rust in coconut or palm oil was a preferred sanding compound.

[0046] Unlike sandpaper or electrical sanders, my blade holder can be used underwater to remove barnacles, clean swimming pools, prepare rusty bridges, clean wet plumbing at nuclear power plants, etc. In the embodiment where my invention utilizes a hacksaw blade, such a blade holder can even remove concrete slag slop that is found around concrete applications.

Example 1

[0047] To illustrate the improvements, I will use the example of restoring a car. A typical, older, rusted car requires car body filler in numerous locations and sanding with about 45-80 sheets of sandpaper. All the car body filler must be first rough sanded, and then increasingly finer sanding paper is used as each area is sanded and re-sanded for a smoother finish before applying paint. For each restored area, the sandpaper is cut into usable pieces and applied to the manual holder. Sandpaper is removed and replaced numerous times. Each piece of sandpaper is then discarded. The professional sander progresses from coarse (24, 30, 40, 50 grit) to medium (60, 80 grit) to fine (100, 120 grit) and very fine (150, 180, 220 grit), obtaining a new piece of sandpaper, cutting and fitting the sandpaper to the manual holder, sanding, removing and discarding the used paper, cutting, fitting, sanding, etc. all day long. At the end of the day, the barrel of used sandpaper is emptied, and the work area covered with sand is swept up. With my new blade holder, we provide the equivalent of hundreds of pieces of sandpaper in three or more grits in one tool; in actual use in restoring cars, I estimate a savings of at least $450 worth of sandpaper.

[0048] For a typical used car, about 40 pieces of superfine sandpaper are needed just to roughen paint surfaces to accept the new paint. If an average car restoration requires 60-80 sheets, the blade holder replaces other sandpaper, about 20-40 sheets. Assuming a sheet of sandpaper costs $1.25, the blade holder obviates the sandpaper expenditure of $25-50 per car. Repeated daily and across multiple cars, the savings add up rapidly.

Example 2

[0049] FIGS. 5A and 5B show an example of an ergonomic blade holder 10 with a smaller handle 100 for grasping and more ergonomic use and a removable handle 110. The removable handle 110 can be any convenient shape; however, having an arch 120 connecting the two sides 130 of the handle tends to make the handle 110 stronger. Opposite sides of the blade holder 10 have at least one notch or depression 140 into which is inserted a short pin (not shown) on the inside of the handle side arm 130. FIG. 5A shows the removable handle 110 in profile. FIG. 5B shows the removable handle 110 from the side. Here are shown multiple notches 140 so that the removable handle 110 can be repositioned to take advantage of the different areas of the blade.

Example 3

[0050] FIGS. 6 and 7 show new designs of the blade holder 210. FIG. 6 shows a blade 220 with larger teeth that are equivalent to coarse sandpaper. FIG. 7 shows a blade with smaller teeth that are equivalent of fine sandpaper. The new designs position the blade 220 just inside the edge of the holder 230. 1 found I could simply hold the two ends of the blade 220 together with a clamp (not shown), fix the blade 220 into the soft car body filler that comprises the bulk of the blade holder 230. The car body filler dries in minutes and the clamp is removed. In spite of the blade 220 being close to the edge of the holder, the blade 220 was maintained in place permanently. Not wishing to be bound by any theory, I propose that the car body filler which normally bonds very tightly to metal on a car body, also bonds tightly to the metal blade and does not require a large margin to keep the blade in place.

Example 4

[0051] In another embodiment, a block of metal is machined to the desired shape to accommodate a worker's hand on the outside and the blade assembly on the inside. The blade assembly typically consists of a blade pinned in a circular or almost circular shape by welding, a screw or bolt, etc. Optionally, the block is machined to leave a plurality of posts arising from the block on the blade assembly side. A metal insert is machined to fit the cavity on the metal block and mate with the protruding posts. Such as metal insert also secures the blade assembly in place. This one-piece or two-piece assembly construction can be varied so long as the blade assembly is fixed in place and does not move independently from the metal block. Such movement would interfere with providing a smooth surface of the car or other base.

Example 5

[0052] The blade holder is easy and highly efficient to use. The tool produces a smooth level surface with less energy and time than is possible with coarse grit sandpaper. In contrast to sandpaper that abrades a surface, the blade holder cuts and shaves the surface. It is three tools in one, depending on how the professional holds it. FIGS. 8A, 8B and 8C illustrate the different angles at which to use the blade holder. FIG. 8A shows a prototype blade holder positioned to effect the fastest, most effective product removal. It removes materials quickly like a knife or razor. One simply pushes it up and down to level the surface by removing chips that are relatively big and coarse, comparable to 40 grit sandpaper.

[0053] FIG. 8B shows the blade holder at an intermediate angle (about half way between FIGS. 8A and 8C). This is the medium cut, similar to 80 grit sandpaper. FIG. 8C shows the blade holder positioned at about 90 degrees off the position in FIG. 8A. This produces a slightly finer grade of smoothness, similar to that of 120 grit sandpaper. This is often sufficient to create a surface ready for painting; however, 200 grit sandpaper can be used to finish. It is easy to even the surface and feather to the edges of the repair.

[0054] In contrast to sandpaper that abrades the surface and needs finer and finer grits for make smaller abrasions, the blade holder is better at smoothing the surface.

[0055] While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alterations, modifications, and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, it is intended to embrace all such alterations, modifications, and variations in the appended claims. [0056] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprise" and/or "comprising", when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one of more other features, integers, steps, operations, elements, components, and/or groups thereof.

[0057] The corresponding structures, materials, acts, and equivalents of all means or step plus function elements in the claims below are intended to include any structure, material, or act for performing the function in combination with other claimed elements as specifically claimed. The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variation will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated.

[0058] While the preferred embodiment to the invention has been described in an illustrative manner, it is to be understood that the terminology which has been used is intended to be in the nature of words of description rather than words of limitation. Many modifications and variations of the invention are possible in light of the above teachings. Therefore, within the scope of the appended claims, the invention may be practiced other than as specifically described.