04004 . 034

SANDING DISC, APPARATUS AND METHOD

TECHNICAL FIELD

This invention relates to sanding and grinding, and more particularly to abrasive discs, apparatus and methods for sanding and grinding floor surfaces .

BACKGROUND OF THE INVENTION

It is known in the art related to sanding and grinding to use conventional abrasive pads or discs, such as resin paper, resin cloth, or similar for coarse and fine sanding or grinding of a surface . Conventional sanding and grinding methods are both time consuming and costly. ■ Multiple sanding steps result in a greater expenditure of time and require the use of multiple sanding pads or discs. Further, conventional abrasive pads and discs wear out quickly and must be frequently replaced.

Further, conventional abrasive pads and discs create swirl marks in the support surface that must be later removed. Further, conventional abrasive pads and discs may gouge the support surface or unevenly sand/grind the support surface.

It is also known in the art relating to sanders that conventional sanders have many shortcomings. First, when sanding or grinding a

surface, especially when using a coarse and/or a wide disc, conventional sanding machines undesirably pull away from the operator and move across the surface. The rotational speed of the sanding/grinding disc combined with the friction between the sanding/grinding disc and the surface cause a conventional sanding machine to forcedly move in a sideways direction. This effect has a negative impact on operator control of the sanding machine and therefore leads to longer task completion times and poorer sanding quality.

Second, when sanding a floor, sanders are generally not capable of sanding close to walls without causing damage to the walls. Usually a drum sander is used to sand a floor and it cannot be brought close to a wall during operation. This undesirably makes it necessary to use a separate tool to sand the edges of the floor.

Third, sanding waste particles generated by a sanding apparatus may be propelled away from the area underneath the sanding apparatus by the rotational action of the sanding disc. Since a conventional sanding apparatus sucks up waste from the area underneath itself, this may lead to some of the sanding waste not .being sucked away from the sanding surface. Therefore, conventional sanding apparatus may not be able to completely remove all of the sanding waste from the sanding surface, undesirably leaving a film of sanding waste on the sanding surface .

It is further known that when a floor or other surface must be wet sanded, water must be manually spread over the surface prior to beginning the sanding operation. This procedure is time consuming and is an inefficient use of water. Also, this procedure may result in a messy work area because the water is not contained within the boundaries of the sanding machine itself.

SUMMARY OF THE INVENTION

The present invention provides a sanding/grinding disc mounting a plurality of independent abrasive elements for use in sanding or grinding a surface such as a hardwood floor, a marble floor, a concrete floor, a metal surface, or similar. The sanding/grinding disc reduces the formation of swirl marks in the working surface and reduces the generation of heat during the sanding and grinding processes. The sanding/grinding disc also reduces the amount bf waste material that remains on the surface after sanding and grinding processes . The sanding/grinding disc leaves the surface smooth and virtually free of waste material.

The present sanding/grinding disc may be used in combination with a sanding apparatus that solves the aforementioned disadvantages of conventional sanders and that can be used to sand or grind a variety of surfaces ^' . The sanding apparatus does not walk or pull away from the operator. The sanding apparatus is also capable of sanding surfaces adjacent to walls without damaging the walls.

Further, the sanding apparatus prevents sanding waste particles generated by the sanding apparatus from being propelled outside of the suction zone of the sanding apparatus. Moreover, the sanding apparatus may include a water supply that dispenses water onto the surface being sanded in a controlled manner and within the boundaries of the sanding apparatus.

More particularly, a sanding disc in accordance with the invention includes a generally circular plate having a mounting surface. A plurality of independent abrasive elements are removably mountable on the mounting surface of the plate. The independent abrasive elements may be blades having an abrasive edge. The blades are operatively disposed at an acute angle relative to the surface of the plate. The blades are coated with diamond material or are impregnated with diamond material. Alternatively, the independent abrasive elements may be abrasive stones.

A sanding apparatus for sanding a surface includes the sanding disc described hereinabove . The sanding disc is mountable on a working device including a housing. A suction ring is operatively connected to the housing and adjustable relative to the housing. The suction ring surrounds the sanding disc. The suction ring includes an annular edge. During operation of the sanding apparatus, both the annular edge of the suction ring and the sanding disc contact the surface.

In another embodiment , a sanding apparatus for sanding a support surface includes an elongated frame having a handle end and a work end. The handle end is arranged for operator control . The work end is operatively connectable to a working device. A stabilizer assembly is adapted to contact and grip the support surface. The stabilizer assembly is disposed between the handle end and the work end and is operatively connected to the frame. The stabilizer assembly includes at least one circular, weighted rotating member mounted thereon. The sanding disc described hereinabove is mounted on the working device. A support may be removably mountable on the frame. A vacuum device or a water dispensing device may be supported in the support.

A method of sanding a support surface includes the step of providing a sanding apparatus including an elongated frame having a handle end and a work end. The handle end is arranged for operator control and the work end is operatively connected to a working device including a housing . A support is removably mountable on the elongated frame . A water dispensing device is supported in the support and is in fluid communication the housing of the working device. A sanding disc is mounted on the working device. The sanding disc includes a generally circular plate having a mounting surface, and a plurality of independent abrasive elements are removably mountable on the mounting surface of the plate. Water flow is regulated from the water dispenser to the housing such that the water drips onto the support surface. The sanding apparatus is

operated such that the sanding disc wet sands the support surface .

In another embodiment , a method of sanding a support surface includes the step of providing a sanding apparatus including a working device including a housing. A sanding disc is mounted on the working device. The sanding disc includes a generally circular plate having a mounting surface, and a plurality of independent abrasive elements are removably mountable on the mounting surface of the plate. A suction ring is operatively connected to the housing and adjustable relative to the housing. The suction ring surrounds the sanding disc and includes an annular edge. The sanding apparatus is operated on the support surface such that the annular edge of the suction ring and the sanding disc simultaneously contact the support surface.

These and other features and advantages of the invention will be more fully understood from the following detailed description of the invention taken together with the accompanying drawings .

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings :

FIG. 1 is a perspective view of a sanding apparatus in accordance with the invention in fluid communication with a vacuum device;

FIG. 2 is a partial sectional view of a sanding disc and suction ring in accordance with the invention;

FIG. 3 is a perspective view of another embodiment of the sanding apparatus including a support for supporting a vacuum device or water dispensing device;

FIG. 4 is partially exploded perspective view of the sanding disc and suction ring of FIG. 2;

FIG. 5 is partial sectional view of the sanding disc illustrating a blade mounted on the disc;

FIG. 6 is a cross-sectional view of the sanding disc taken along the line 6-6 in FIG. 5;

FIG. 7 is partial view of the sanding apparatus illustrating mounting of a working device to a frame of the sanding apparatus;

FIG. 8 is a partial view of the sanding apparatus illustrating mounting of the support on the frame of the sanding apparatus;

FIG. 9 is plan view of an alternative embodiment of a sanding disc in accordance with the invention; and

FIG. 10 is a perspective of the sanding disc of FIG. 9 and the suction ring.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings in detail, numeral 20 generally indicates a sanding/grinding disc in accordance with the present invention. The sanding/grinding disc 20 may be used in combination with a suction ring 22 and/or a sanding apparatus 24.

The sanding/grinding disc 20 includes a generally circular plate 26 having a first surface and a second, mounting surface 28 opposite the first surface. The first surface is adapted for mounting on a sanding or grinding apparatus. A plurality of independent abrasive elements 30 are mountable on the mounting surface 28. When the sanding disc 20 is in use, the mounting surface 28 of the circular plate 26 faces a surface being sanded.

As shown in FIGS. 2 and 4 - 6, in one embodiment a plurality of blades 32 having an abrasive edge 34 are supported by the circular plate

26 on the mounting surface 28 and spacedly disposed about the mounting surface 28. Each blade 32 is generally disposed closer to an outer edge of the circular plate 26 than to the center of the plate.

Further, each blade 32 is disposed at an angle relative to a radius of the circular plate 26. Each blade 32 is also disposed at an angle relative to the circular plate mounting surface 28 such that each blade operatively extends at an acute angle relative to the mounting surface. The invention is not limited to a specific number of blades, nor is the invention limited to one specific size of blade.

In this embodiment, the sanding/grinding disc 20 may include a plurality of blade assemblies mounted on the mounting surface 28 of the circular plate 26. Each blade assembly includes a support member integral with or mounted on the mounting surface 28 of the circular plate 26 by fasteners or other similar mounting means. One of the blades 32 is angularly disposed relative to the support member by being integral therewith or fastened or secured by other similar mounting means. The blade assemblies are disposed integrally or mounted proximate the outer edge of the circular plate 26 and are angled relative to radii of the circular plate extending from the center of the plate to the outer edge.

The abrasive edge 34 of each blade 32 may include a plurality of abrasives 36 coated thereon or impregnated therein. These abrasives 36 may be tiny diamond bits or similar impregnated or coated on an outer edge of the blade 32 for contact with a support surface during sanding or grinding. Alternatively, each blade 32 may include another similar abrasive- type material other than diamond bits. The invention is not limited to blades having diamond bits. Further, the diamond bits may be mounted over a majority of the outer surface of the blade, and not just on an outer edge of the blade.

The circular plate 26 also includes a plurality of apertures disposed along arcs and/or rings that are concentric with the outer edge of the plate. One of the arcs may be closer to the center

of the circular plate 26 than the blade assemblies. The apertures allow for the suction of sanding/grinding waste from the working surface by a vacuum source .

In operation, the sanding/grinding disc 20 may be mounted to a sanding/grinding apparatus 24 such as a rotary sander, an orbital sander, a random orbital sander, or similar. When mounted to a sanding or grinding apparatus 24 in a use position, the sanding/grinding disc 20 is contactable with a working surface to be sanded or ground. The sanding/grinding apparatus 24 rotates the sanding/grinding disc 20 at conventional rotational speeds up to 1200 rpm and above. As the sanding/grinding disc 20 rotates, the blades 32 skim along the working surface without forming grooves or swirls in the support surface. The circular plate 26 is rotated in a direction such that the blades 32 are dragged across the working surface, i.e., the leading edge 34 of each blade 32 forms an acute angle with the working surface. The angular position of the blades 32 relative to the working surface allows the blades to scrape the working surface while simultaneously saw cutting the surface. The blades 32 evenly and equally sand/grind the working surface. This leaves the working surface smooth and straight without gouges or swirl marks .

The sanding/abrasive disc 20 is self- cleaning and does not become clogged with waste material generated during sanding/grinding the working surface. The angle of the blades 32 relative

to radii of the circular plate 26 drives sanding waste towards the center of the plate as the sanding/abrasive disc 20 rotates. The sanding waste is then sucked away from the working surface through the apertures in the circular plate 26. The arrangement of the blades 32 prevents sanding waste from escaping beyond the outer edge of the circular plate 26 and forces sanding waste away from the blades 32 towards the center of the circular plate, cleaning the blades and preventing clogging.

The sanding/abrasive disc 20 also dissipates heat generated from sanding/grinding the support surface by functioning like a fan. While sanding/grinding a working surface, the blades 32 simultaneously function as fan blades to blow air over the working surface. This cools both the working surface and the blades themselves .

The blades 32 may have a useful life of between five and ten years. When the blades 32 are worn, they may be removed from the support member and replaced with new blades. The rest of the sanding/abrasive disc 20 does not need to be disposed of.

Turning to FIGS. 9 and 10, in an alternative embodiment of the sanding/grinding disc 120, the independent abrasive elements may be abrasive stones 138 or similar. A mounting assembly mounts each abrasive stone to the mounting surface 128 of the circular plate 126. Each mounting assembly includes a fixed mounting member, an

adjustable mounting member, and at least one retention post. The fixed mounting member and adjustable mounting member both include a groove that engages an ^' outwardly projecting surface of the abrasive stone 138. The grooves and the abrasive stone 138 are angled such that the abrasive stone is prevented from moving outwardly away from the circular plate 126. The retention post (s) prevent the abrasive stone 138 from moving inwardly towards the center of the circular plate 126.

When an abrasive stone 138 has become worn beyond its usefulness and must be replaced, the adjustable mounting member is loosened and moved to the side.. This releases the abrasive stone 138 from the grooves in the adjustable mounting member and the fixed mounting member. The fixed mounting member remains in place. A new abrasive stone 138 is then engaged with the groove of the fixed mounting member and is also supported by the retention post (s) . The groove of the adjustable mounting member may then be reengaged with the abrasive stone 138 and tightened into place.

The abrasive/sanding disc 20 may be used in combination with a self-adjusting suction ring assembly 40. The suction ring assembly 40 may include a holding plate that allow for connection of the suction ring 40 to a gear housing or similar housing 42 of a working device 44 of the sanding apparatus 24. The holding plate may be an O-shaped disc having an inner portion and an outer portion. An inner annular edge is adjacent to the inner

portion and an outer annular edge is adjacent to the outer portion. The inner annular edge and the outer annular edge may be concentric circles. The inner portion of the holding plate mounts to the gear housing 42. The suction ring assembly 40 further includes a tubular-like ring. The outer portion of the holding plate is mounted to the ring. Hence, the holding plate extends radially from the gear housing 42 to the ring. In an alternative embodiment, the holding plate may be integral with the gear housing 42 such that the holding plate and the gear housing are one piece.

The holding plate includes an aperture therethrough sized to fit a suction tube. A suction tube in communication with a vacuum source may thereby be detachably secured to the holding plate. This allows sanding waste (sanding particles generated by the sanding apparatus) to be sucked from underneath the area bounded by the gear housing, the holding plate, and the ring. The aperture may be located in the outer portion of the holding plate. In an alternative embodiment, a source of water may be connected to the aperture to allow for flow of water from the water supply to the area within the suction ring assembly 40. This is useful when it is desired to wet sand a surface. Advantageously, the water is released into the area circumscribed by the ring and is kept within the suction ring assembly 40 when the ring is in contact with a working surface. A flow control valve may control the amount of flow of water from the water supply.

The tubular-like ring includes a ledge and an annular wall extending from the ledge to an outer annular edge 46. When the suction ring assembly 40 is in use, the outer edge 46 of the annular wall contacts the working surface, such as a floor or similar. The outer edge 46 may include a layer of rubber or other similar material to prevent the outer edge from scratching the working surface . The suction ring assembly 40 prevents sanding waste from escaping beyond the area underneath the working device 44 of the sanding apparatus 24. The annular wall is slightly larger in diameter than the sanding disc 20 so that there is a gap between the inside of the annular wall and the sanding disc. The ledge of the ring may have a notch aligned with the aperture in the holding plate to provide clearance for the suction tube to be inserted into the holding plate aperture. The ring is mounted to the holding plate through the ledge . The ring may be mounted to the holding plate by fasteners such as a bolts, pins, or similar. In a specific embodiment, the ring is secured to the holding plate by three fasteners, each having a head and an elongated shaft . The heads may be greater in diameter than the shafts. A resilient member, such as a spring or similar, may be disposed along the shaft between the head and the ledge of the ring.

The combination of the fasteners and the resilient members allow the ring to automatically adjust its height or float so that the edge 46 of the annular wall contacts the working surface no matter how thick (i.e., tall) the sanding/abrasive disc 20

applied thereto is. As the height of the sanding disc 20 varies, the resilient members are compressed or decompressed, allowing the edge 46 of the annular wall to maintain contact with the working surface while the sanding disc 20 also contacts the working surface. If the suction ring assembly 40 could not adjust its height, then the suction ring assembly 40 could not align its edge with the working surface when the thickness of the sanding disc 20 is varied. If the edge 46 of the ring is above the working surface, then the vacuum source undesirably sucks false air through the space between the edge 46 of the ring and the working surface, thereby decreasing the suction power of the working device 44. Also, if the speed of the working device 44 is sufficiently high, sanding waste could escape through the space between the edge 46 of the ring and the sanding surface. The suction ring assembly 40 prevents this from occurring.

When in use, the self-adjusting, floating suction ring assembly 40 prevents sanding waste from escaping the suction of a vacuum source. Specifically, as described above, as the height of the sanding disc 20 varies, the suction ring assembly 40 adjusts itself so that its outer edge 46 contacts the working surface when the sanding disc 20 contacts the working surface. The suction ring assembly 40 thereby creates a barrier around the sanding disc 20. When the working device 44 is turned on, the sanding disc 20 begins to sand the working surface, generating sanding waste. The fast, circular motion of the sanding disc 20 may propel the sanding waste

outside of the circumference of the sanding disc. The sanding waste, however, cannot escape past the barrier created by the suction ring assembly 40 and begins to accumulate in the space between the outer edge of the sanding disc 20 and the outer edge 46 of the suction ring assembly 40. The suction tube, being disposed adjacent the ring and being in communication with a vacuum source, easily sucks the sanding waste away from the working surface . Therefore, no sanding waste escapes from the suction of the vacuum source communicated through the suction tube, and the working surface is completely cleaned of sanding waste .

Furthermore, the suction ring assembly 40 allows the sanding disc 20 to be brought close to a wall adjacent a support surface without the sanding disc damaging the wall. Since the sanding disc 20 is disposed within the suction ring 40, the suction ring may travel along a wall without the sanding disc 20 ever contacting the wall .

With reference to FIGS. 1 through 3, the abrasive/sanding disc 20 and the suction ring assembly 40 may be used in combination with the sanding apparatus 24. The sanding apparatus 24 includes an elongated frame 48 and weighted stabilizer rollers. The elongated frame 48 has a handle end 50 and a work end 52. The handle end 50 is arranged for operator control and the work end 52 is adapted for connection to the working device 44. The working device 44 may be a sanding device, a grinding device, or similar abrasive device capable

of sanding and/or grinding a surface, such as an orbital sander, a circular sander, or a rotary sander. The working device 44 may use the abrasive disc 20 or 120, may or may not use water, and may be driven by electricity or pressurized air. The sanding apparatus 24 also includes a stabilizer assembly 54 adapted to contact and grip a support surface. The support surface may be a floor, marble, stone, or similar. The stabilizer assembly 54 is disposed between the handle end 50 and the work end 52 and prevents the sanding apparatus 24 from pulling away from an operator during use. Preferably, the stabilizer assembly 54 may be disposed closer to the work end 52 than the handle end 50.

The stabilizer assembly 54 includes a plurality of circular, weighted rotating member 56 mounted thereon. The use of a plurality of adjacent circular rotating members allows for differential rotation of the circular rotating members, enabling easier turning of the sanding apparatus by an operator. The circular rotating members 56 may be mounted on the stabilizer assembly 54 by an axle, opposing pins, or other similar suitable mount. The circular rotating members 56 may be wheels, rollers, or similar, may have any suitable diameter and width, and may be aided in rotation by bearings or similar. The circular rotating members 56 may include a peripheral friction layer. The friction layer may be a rubber-like material or similar material that aids the circular rotating member 56 in gripping the support surface without damaging the surface. The circular rotating members 56 may slide from side to

side as well as rotate to allow an operator to move the sanding apparatus 24 in any desired direction. The circular rotating members 56 also allow the sanding apparatus 24 to partially move off an edge of a support surface without the sanding apparatus tilting towards one of its sides.

The circular rotating members 56 are weighted. For example, the circular rotating members 56 may be weighted to a total weight of 10 pounds, which is suitable for light sanding applications, or the circular rotating members may be weighted to a total weight of 125 pounds, which is suitable for heavy grinding applications. Generally, the lighter the sanding/grinding application, the less weight that is needed and the heavier the sanding/grinding application, the more weight that is needed. In any event, the circular rotating members 56 may be weighted to any desired weight.

Further, the stabilizer assembly 54 may include anti-friction washers separating the circular rotating members 56. The anti-friction washers may be constructed of a polycarbon material, Teflon ^® , or similar. The anti-friction washers enhance the differential rotation of the circular rotating members 56.

In a specific embodiment, the stabilizer assembly 54 of the sanding apparatus 24 includes three circular rotating members 56. Two of the circular rotating members may be wider than the third circular rotating member. The wider circular

rotating members are disposed on either side of the narrower circular rotating member. The anti -friction washers are disposed between the circular rotating members 56. In this embodiment, when an operator turns the sanding apparatus to the left or right, the wider, outer circular rotating members rotate in opposite directions (i.e., one clockwise, the other counter-clockwise) and the narrower, inner circular rotating member rotates only a small amount relative to the outer rotating members. This allows the operator to easily move and turn the sanding apparatus 24 while at the same time assures that the movement of the sanding apparatus is controlled and that the sanding apparatus does not pull or walk away from the operator.

The handle end 50 of the elongated frame 48 may include a handle. The handle may be universally rotatable about the elongated frame, allowing the handle to be rotated 360 degrees about the elongated frame. This is useful, for example, when sanding along an edge of a wall because the handle may contact the wall when in a horizontal orientation but not while in a vertical orientation. An operator therefore can rotate the handle towards a vertical orientation when approaching and sanding along a wall, and then move the handle back to a standard horizontal orientation afterwards. The handle may also be adjusted along the length of the frame to allow the handle to be lengthened and shortened. The handle is therefore fully adjustable for each individual operator.

The handle end 50 may further include controls such as a speed reducer, a master on/off switch, a power trigger, and a safety shutoff device. The speed reducer may be a rheostat and may allow for the adjustment of the speed of the motor of the working device 44. It may be desirable to adjust the speed of the motor depending on the sanding/grinding application, i.e., on the type of surface being sanded/grinded. The speed reducer may allow for a three second delay when the power trigger is pulled into a start position. The delay allows for a smoother start to the motor so that the motor does not abruptly go from being at rest to a high speed.

The working device 44 of the sanding apparatus 24 may be operatively, pivotally connected to the work end 52 of the elongated frame 48. The working device 44 includes a gear housing. Pivot ears extending from the gear housing may allow for the pivotal connection of the working device 44 to the elongated frame 48. The gear housing is rotatable about the pivot ears . The working device 44 may also include a motor mounted on the gear housing and a mount operatively, drivingly connected to the motor through the gear housing. The mount allows for the mounting of a sanding/abrasive disc thereon .

The construction of the elongated frame 48 allows the frame to be disassembled into subcomponents for easier storage and transport.

Further, as shown in FIG. 7, the work end 52 of the frame 48 may be easily connected to the stabilizer 54

of the frame 48. One of the frame members extending from a pivot ear of the working device 44 may be longer than another frame member extending from the other pivot ear of the working device. An operator first engages the longer frame member with the stabilizer 54 and then engages the short frame member with the stabilizer. This prevents the operator from having to align and engage both frame members at the same time, which is difficult.

With reference to FIGS. 3 and 8, the frame 48 may include a support 58 mountable above the stabilizer 54. The support 58 may include a bucket sized to receive and carry a vacuum device 60 or a water supply. For example, a vacuum device 60 and

-accompanying waste receptacle can be placed in the bucket . A vacuum hose can be connected between the vacuum device 60 and the work end 52 of the sanding apparatus 24, and the vacuum can be electrically connected to a master power supply at the handle end 50 of the frame 48. As an operator uses the sanding apparatus 24, the vacuum device 60 is thereby conveniently carried along with the sanding apparatus. In a similar manner, a water source such as a water dispenser or similar may be placed in the bucket . The water dispenser may be connected by a hose to the work end of the sanding apparatus . This arrangement allows an operator to wet sand a working surface without having to separately carry a source of water.

As shown in FIG. 8, the support 58 may also include a plurality of mounting members that extend

from a lower side of the bucket and that are receivable in one or more receivers located above the stabilizer 54 of the frame 48. In one embodiment, the support 58 includes three mounting members and the frame 48 includes two receivers. One of the mounting members may be disposed generally centrally underneath the bucket, while the other two mounting members are spacedly disposed on generally opposite sides of the central mounting member. To mount the support 58, the central mounting . member and one of the side mounting members are inserted into the receivers. This disposes the support 58 to one side of the frame 48 such that the support is within an outer boundary of the frame on one side of the frame. This is useful when the sanding apparatus is moved along a wall on this side of the frame. If it is desired to move the other side of the sanding apparatus 24 along a wall, the support 58 may be lifted out of the receivers, and then the central mounting member and the other side mounting are inserted into the receivers .

Although the invention has been described by reference to specific embodiments, it should be understood that numerous changes may be made within the spirit and scope of the inventive concepts described. Accordingly, it is intended that the invention not be limited to the described embodiments, but that it have the full scope defined by the language of the following claims.