Balancing Weight System for Hand-Held Surface Angle Grinders

Abstract

This invention is a device and method for weighting and balancing ar hand-held electric angle grinder. A weight shaft is mounted on the frame of the angle grinder coaxially with the axis of rotation of the angle grinder motor. A selection of weights can be mounted on the weight shaft to provide extra downward pressure, through the motor and frame, to the grinding disc of the angle grinder. The weights are also selected to suppress vibration that is produced by the interaction between the grinding disc and the surface. As a result, the present invention provides an angle grinder that is easier and less exhaustingI to use, is less likely to have any harmful effects on the user, is able to provide a more effective functioning of the angle grinder, and is able to provide a treated work surface of better quality and less expense.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit under 35 U.S.C. § 119(e) of U.S. Provisional Application No. 63/173,495 filed Apr. 11, 2021, which is hereby incorporated by reference.

FEDERALLY SPONSORED RESEARCH

This invention has been created without the sponsorship or funding of any federally sponsored research or development program.

FIELD OF INVENTION

The present invention is a weighting and balancing system for hand-held electric angle grinders.

BACKGROUND OF THE INVENTION

Prior systems for hand-held electric angle grinders, are frequently used for polishing or otherwise treating large surfaces, and particularly for polishing and treating concrete floors. In the case of concrete floors, the operation, particularly the edging work adjacent the walls, involves long hours of exhausting hands and knees operation. Because the angle grinders must be portable and relatively small in size, they are generally lightweight and therefore achieve the grinding operation very slowly.

Furthermore, the way that the rotating grinding surface interacts with the concrete and the angle grinder causes a great deal of vibration which is conveyed to the user's hands and arms, and makes the work not only exhausting, but also potentially physically stressfull and potentially harmful to the user. In addition, the vibration interferes with the affective polishing operation, and therefore requires a great deal of skill on the part of the operator to achieve the desired polished surface.

These and other difficulties experienced with the prior art devices have been obviated in a novel manner by the present invention.

It is, therefore, an outstanding object of some embodiments of the present invention to provide a system for temporarily and adjustably increase the weight of the angle grinder, so that the angle grinder can be set up to provide the optimum performance in polishing surfaces while still maintaining its light weightp in situations where additional weight is not necessary and its portability is maintained when transporting the product .

Another object of some embodiments of the present invention is to provide a system for reducing the vibration of the angle grinder when it is being used to polished surfaces.

A further object of some embodiments of present invention is to provide a system for making the of the angle grinder less exhausting for the user when it is being used to polished surfaces.

It is another object of some embodiments of the present invention is to provide a system for minimizing the adverse health effects of using angle guide grinders to polished surfaces over long periods of time.

It is a further object of some embodiments of the present invention to provide a system for maximizing the effectiveness of using an angle grinder for polishing surfaces while also minimizing any adverse effects to the user.

With these and other objects in view, as will be apparent to those skilled in the art, the invention resides in the combination of parts set forth in the specification and covered by the claims appended hereto, it being understood that changes in the precise embodiment of the invention herein disclosed may be made within the scope of what is claimed without departing from the spirit of the invention.

SUMMARY OF THE INVENTION

The present invention is a weighting and balancing system for hand-held electric angle grinders. A weight shaft is mounted on the frame of the angle grinder coaxially with the axis of rotation of the angle grinder motor. A selection of weights can be mounted on the weight shaft to provide extra downward pressure, through the motor and frame, to the grinding disc of the angle grinder. The weights are also selected to suppress vibration that is produced by the interaction between the grinding disc and the surface.

BRIEF DESCRIPTION OF THE DRAWINGS

The character of the invention, however, may best be understood by reference to one of its structural forms, as illustrated by the accompanying drawings, in which:

FIG. 1 is a perspective view of the front top of an angle grinder with the general features, including two weight discs mounted on the weight shaft, of one embodiment of the present invention.

FIG. 2 is a perspective view of the front top of an angle grinder with the general features, including one weight disc mounted on the weight shaft, of one embodiment of the present invention.

FIG. 3 is a perspective view of the front top of an angle grinder with the general features, without any weight discs mounted on the weight shaft, of one embodiment of the present invention.

FIG. 4 is a perspective view of the front top of an angle grinder with the general features, without any weight discs mounted and without the weight shaft and showing the weight shaft bracket, of one embodiment of the present invention.

FIG. 5 is a perspective view of the front top of an angle grinder with the general features, without any weight discs mounted and without the weight shaft and without the weight shaft bracket, of one embodiment of the present invention.

FIG. 6 is a perspective view of the front top of an angle grinder with the general features, without any weight discs mounted and without the weight shaft and showing the weight shaft bracket, of one embodiment of the present invention.

FIG. 7 is a another perspective view of the front top of an angle grinder with the general features, without any weight discs mounted and without the weight shaft and showing the weight shaft bracket, of one embodiment of the present invention.

FIG. 8 is a perspective view of the weight shaft bracket of one embodiment of the present invention.

FIG. 9 is a perspective view of the weight shaft of one embodiment of the present invention.

FIG. 10 is a perspective view of the weight shaft bracket of one embodiment of the present invention.

FIG. 11 is a perspective view of the weight shaft of one embodiment of the present invention.

FIG. 12 is a perspective view of the weight shaft bracket of one embodiment of the present invention.

FIG. 13 is a perspective view of the weight shaft of one embodiment of the present invention.

FIG. 14 is a side elevation view of a second grinder with the general features, without any weight discs, but with the weight shaft bracket and weight shaft, of a second embodiment of the present invention.

FIG. 15 is a front elevation view of a second grinder with the general features, without any weight discs, but with the weight shaft bracket and weight shaft, of a second embodiment of the present invention.

FIG. 16 is a top view of a second grinder with the general features, without any weight discs, but with the weight shaft bracket and weight shaft, of a second embodiment of the present invention.

FIG. 17 is a side elevation view of a third grinder with the general features, without any weight discs, but with the weight shaft bracket and weight shaft, of a third second embodiment of the present invention.

FIG. 18 is a side elevation view of a third grinder with the general features, without any weight discs, without the weight shaft bracket and without the weight shaft, of a third second embodiment of the present invention.

FIG. 19 is a top view of a third grinder with the general features, without any weight discs, without the weight shaft bracket and without the weight shaft, of a third second embodiment of the present invention.

FIG. 20 Is a top view of a dust collector embodying some of principles the present invention.

FIG. 21 is a side elevation view of a third grinder with the general features, without any weight discs, without the weight shaft bracket and without the weight shaft, of a third second embodiment of the present invention.

FIG. 22 is a side elvation view of the dust collector shown in FIG. 20, and embodying some of principles the present invention.

FIG. 23 is is a perspective view of the front top of a fourth angle grinder with the general features, without any weight discs mounted and without the weight shaft and but showing the weight shaft bracket, of a fourth embodiment of the present invention.

FIG. 24 is a perspective view of the weight shaft bracket shown in FIG. 23.

FIG. 25 is a perspective view of the fourth angle grinder shown in FIG. 23, but without weight shaft bracket attached.

FIG. 26 is a perspective view of the fourth angle grinder shown in FIG. 23, but with the weight shaft bracket attached, and the weight shaft attached.

FIG. 27 is a perspective view of the weight shaft bracket, with weight shaft attached, shown in FIG. 26.

FIG. 28 is a perspective view of the weight shaft bracket, with weight shaft attached shown in FIG. 26, and a palm rest/disk lock mounted on the top of the weight shaft.

FIG. 29 is a another perspective view of the weight shaft bracket, with weight shaft attached shown in FIG. 26, and a palm rest/disk lock mounted on the top of the weight shaft.

FIG. 30 is a another perspective view of the weight shaft bracket, mounted on the angle grinder, with weight shaft attached shown and a palm rest/disk lock mounted on the top of the weight shaft, and a weight disc mounted on the weight shaft.

FIG. 31 is a another perspective view of the weight shaft bracket, not mounted on the angle grinder, with weight shaft attached shown and a palm rest/disk lock mounted on the top of the weight shaft, and a weight disc mounted on the weight shaft.

FIG. 32 is a bottom view of a first grinding tool suitable for use with and part of the present invention.

FIG. 33 is a bottom view of a second grinding tool suitable for use with and part of the present invention.

FIG. 34 is a bottom view of a third grinding tool suitable for use with and part of the present invention.

FIG. 35 is a bottom view of a fourth grinding tool suitable for use with and part of the present invention.

FIG. 36 is a bottom view of a fifth grinding tool suitable for use with and part of the present invention.

FIG. 37 is a front elevation view of a cart for storing and transporting the equipment involved in using the angle grinders embodying the priciples of the present invention.

REFERENCE NUMERALS
Angle grinder 10  Frame 12
Power cord 14     Motor 16
Motor Shaft 18    Grinding disc 20
Weight bracket 22 Weight shaft 24
Weight disc 26

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the invention in more detail, in FIG. 1 there is shown a perspective view of the front top of an angle grinder with the general features, including two weight discs mounted on the weight shaft.

FIG. 2 is a perspective view of the front top of an angle grinder including one weight disc mounted on the weight shaft.

FIG. 3 is a perspective view of the front top of an angle grinder without any weight discs mounted on the weight shaft.

FIG. 4 is a perspective view of the front top of an angle grinder without any weight discs mounted and without the weight shaft and showing the weight shaft bracket.

FIG. 5 is a perspective view of the front top of an angle grinder without any weight discs mounted and without the weight shaft and without the weight shaft bracket.

FIG. 6 is a perspective view of the front top of an angle grinder without any weight discs mounted and without the weight shaft and showing the weight shaft bracket.

FIG. 7 is a another perspective view of the front top of an angle grinder without any weight discs mounted and without the weight shaft and showing the weight shaft bracket.

FIG. 8 is a perspective view of the weight shaft bracket of one embodiment of the present invention.

FIG. 9 is a perspective view of the weight shaft of one embodiment of the present invention.

FIG. 10 is a perspective view of the weight shaft bracket of one embodiment of the present invention.

FIG. 11 is a perspective view of the weight shaft of one embodiment of the present invention.

FIG. 12 is a perspective view of the weight shaft bracket of one embodiment of the present invention.

FIG. 13 is a perspective view of the weight shaft of one embodiment of the present invention.

FIG. 14 is a side elevation view of a second grinder with the general features, without any weight discs, but with the weight shaft bracket and weight shaft, of a second embodiment of the present invention.

FIG. 15 is a front elevation view of a second grinder without any weight discs, but with the weight shaft bracket and weight shaft, of a second embodiment of the present invention.

FIG. 16 is a top view of a second grinder with the general features, without any weight discs, but with the weight shaft bracket and weight shaft, of a second embodiment of the present invention.

FIG. 17 is a side elevation view of a third grinder without any weight discs, but with the weight shaft bracket and weight shaft, of a third second embodiment of the present invention.

FIG. 18 is a side elevation view of a third grinder with the general features, without any weight discs, without the weight shaft bracket and without the weight shaft, of a third second embodiment of the present invention.

FIG. 19 is a top view of a third grinder without any weight discs, without the weight shaft bracket and without the weight shaft, of a third second embodiment of the present invention.

FIG. 20 Is a top view of a dust collector embodying some of principles the present invention.

FIG. 21 is a side elevation view of a third grinder with the general features, without any weight discs, without the weight shaft bracket and without the weight shaft, of a third second embodiment of the present invention.

FIG. 22 is a side elvation view of the dust collector shown in FIG. 20, and embodying some of principles the present invention.

FIG. 23 is is a perspective view of the front top of a fourth angle grinder without any weight discs mounted and without the weight shaft and but showing the weight shaft bracket, of a fourth embodiment of the present invention.

FIG. 24 is a perspective view of the weight shaft bracket shown in FIG. 23.

FIG. 25 is a perspective view of the fourth angle grinder shown in FIG. 23, but without weight shaft bracket attached.

FIG. 26 is a perspective view of the fourth angle grinder shown in FIG. 23, but with the weight shaft bracket attached, and the weight shaft attached.

FIG. 27 is a perspective view of the weight shaft bracket, with weight shaft attached, shown in FIG. 26.

FIG. 28 is a perspective view of the weight shaft bracket, with weight shaft attached shown in FIG. 26, and a palm rest/disk lock mounted on the top of the weight shaft.

FIG. 29 is a another perspective view of the weight shaft bracket, with weight shaft attached shown in FIG. 26, and a palm rest/disk lock mounted on the top of the weight shaft.

FIG. 30 is a another perspective view of the weight shaft bracket, mounted on the angle grinder, with weight shaft attached shown and a palm rest/disk lock mounted on the top of the weight shaft, and a weight disc mounted on the weight shaft.

FIG. 31 is a another perspective view of the weight shaft bracket, not mounted on the angle grinder, with weight shaft attached shown and a palm rest/disk lock mounted on the top of the weight shaft, and a weight disc mounted on the weight shaft.

FIG. 32 is a bottom view of a first grinding tool suitable for use with and part of the present invention.

FIG. 33 is a bottom view of a second grinding tool suitable for use with and part of the present invention.

FIG. 34 is a bottom view of a third grinding tool suitable for use with and part of the present invention.

FIG. 35 is a bottom view of a fourth grinding tool suitable for use with and part of the present invention.

FIG. 36 is a bottom view of a fifth grinding tool suitable for use with and part of the present invention.

FIG. 37 is a front elevation view of a cart for storing and transporting the equipment involved in using the angle grinders embodying the priciples of the present invention.

Details: This invention is a balancing weight kit to effectively apply increased downward pressure that in turn increases productivity, reduces worker fatigue and results in safer of operation of the hand-held grinding system. In addition, this kit stabilizes and minimizes the oscillations and vibrations that often occur when rotary angle grinders are used to grind and polish surfaces, especially horizontal surfaces such as concrete floors. This oscillations and vibrations, when not stabilized and minimized, may represent a substantial danger to the users.

The Balancing Weight System is used to modify an existing angle grinder. An angle grinder with the BTS attachment is used in the concrete and stone preparation and finishing industry. Concrete/Stone preparation is a vital step in many areas of construction and finish work. These areas include: 1) Epoxy and Resinous Flooring, 2) Polished Concrete, 3) Terrazzo Flooring, 4) Decorative marble and granite stone industry, 5) Commercial and industrial flooring contractors.

The Balancing Weight system is used within the above-mentioned industries to enhance the concrete preparation process for the application of coatings. Larger machines can be used in open areas of the floor, but the edges of the floor, where the wall meets the floor, is too tight of a space for these larger walk-behind machines. A hand tool, such as an angle grinder, is needed to properly prepare these areas. Proper preparation consists of grinding to remove the existing top layers of concrete to create the required profile for adhesion of the product being installed. When used in finish work, the same concept applies. A grinder is used to slowly remove the top layers of the concrete or stone to create a smooth, dense surface.

The Balancing Weight System allows the user to safely and effectively weigh down the angle grinder. Thus, balancing the tool on its center axis and creating downward pressure on the effected material.

The Balancing Weight System can be used in the following areas of construction and finishing: 1) Epoxy Flooring—to grind the concrete substrate as preparation for the application of coating—especially the edges at walls and smaller areas where larger equipment cannot access.

Another area is 2) Polished Concrete—to hone and finish the edges and smaller areas where the larger equipment cannot access. This generally follows a multi-step grinding process to achieve the desired finished product.

Another area is 3) Terrazzo flooring—to hone and finish the edges and smaller areas where the larger equipment cannot access. This generally follows a multi-step grinding process to achieve the desired finished product.

Another area is 4) Decorative Marble and Granite Stone Industry—to hone and finish the edges and smaller areas where the larger equipment cannot access. This generally follows a multi-step grinding process to achieve the desired finished product. 5) Commercial and Industrial Flooring Contractors—To grind to remove old glue and mastic from prior flooring applications along edges, in corners and detail work. Also used to prepare cementitious underlayment prior to new flooring installation. The tool is needed for detail work at transitions and edges, hallways and small rooms where larger equipment cannot fit or finer detail is needed.

Most often concrete slabs and stone work require edge and detail work due to the nature of their location and usage. A larger stand-behind or ride-on grinder requires a minimum area of floor space to use. Hand held grinders, such as an angle grinder, is needed for the areas where the larger grinders cannot access. Often, these areas are uneven which, in turn, makes the grinder hard to maneuver, keep level and maintain consistent and even downward pressure on all areas of the floor. By modifying the angle grinder through the installation of the Balancing Weight System, the grinder becomes easier to control resulting in a more consistent finished product. Additionally, the Balancing Weight System reduces the need for user produced downward pressure. Thus, resulting in less worker fatigue which in turn creates a safer work environment with increased productivity and efficiency.

Currently, there are no safe alternative solutions to this issue. In the past, operators have piled sandbags and other weighted devices on the grinder—but this creates an unbalanced dangerous situation. Also, without a device to contain the weighted material, the motor vents on the grinder can be blocked and in turn suffocates the motor and burns the unit out prematurely. This also creates a new avenue for a potentially dangerous and unsafe working condition to arise.

With the Balancing Weight System installed on the hand-held grinder the user is less likely to lift the grinder off the floor while it is running, creating an extremely dangerous situation.

In order to increase grinder efficiency and operator productivity, the user must push down on the unit using their upper body and torso muscles. This unsustainable working condition rapidly creates worker fatigue resulting in inconsistencies in the final product. In the all-fours position needed to operate a hand-held grinder on a floor, back injuries are common. Relieving the operator of the additional force they must produce may, in turn, minimize the potential for related injuries.

Controlled down pressure created by the Balancing Weight System means minimizing worker fatigue, maximizing the life of the hand-held grinder and more consistent and controlled finishing.

Although there is not a similar product on the market, using the Balancing Weight System is superior the alternative because it is safer, allows for a more efficient and controlled production, and creates a better product.

I have discovered that highly effective downward weighting pressure on the conventional hand-held surface angle grinder can be achieved and the danmping and elimination of undesired oscillations and vibrations can be achieved by installing and using the balancing kit I have invented.

Essentially, the benefits on this invention are achieved by attaching easliy removeable, and variable weights to the grinder so that the center of gravity of the weights is positioned on and symstrical with the axis of the rotating grinding disk or cap of the grinder, and above the the rotating grinding disk or cap of the grinder.

The optimum way to accomplish that positioning is the, first, mount a bracket on the top of the grinder, ideally using the treaded bore that are normally available on the grinder to attach various handles. Then, a weight-bearing cylindrical shaft is mounted to the bracket, so that the shaft extends upward from the bracket and is co-axial with the axis of revolution of the grinding disk or cup. Then a series of round weight plates, with a bore through their center, just like bar bell plates, are mounted on the shaft, to form a weight stack. The weight plates are mounted to achieve a downward weight pressure and vibration stabilization optimized for a specific surface grinding application.

FIGS. 1 through 37 show various views of the preferred embodiment of the invention installed on an angle grinder, and subassemblies thereof.

Balancing Weight System takes away the need for the operator to use torso/arms to apply pressure on the grinder. The Balancing Weight System is centered over the axis of the grinding disc allowing the operator to steer the unit through the work, rather than muscle through it. With the installation of the Balancing Weight System the grinder can maneuver over various types of surfaces with ease.

Angle grinders come in many sizes and versions . Custom Grinders both 7 and 5 inch diameter grinding disk models , heavy duty variable speed motors built exclusively for this horizontal surface grinding technology. There are also 9- or 10-inch grinders that should be considered as a very heavy duty option.

Dust Shrouds can be custom designed for low profile smallest possible diameter to access the work area, even when a wall or other perpendicular surface abuts the work area. A 2 inch receiver for standard vacuum hose for the 7 inch and smaller hose mount for the 5 inch. would be appropriate .

Ideally, there would be a palm rest that is mounted and slides in above the weight stem; one that swivels and a second design option that could be a tee-type to help steer the whole unit.

The weight stem itself could be a low-profile shaft of rectangular stock with the same cut-out in the center of the weights, so that the weights cannot rotate while operating the grinders.

The weights ideally will be built to be a tight fit to the shaft, or have a damping or resilient element between the weight and shaft, so as not to move or vibrate. The weights should have the smallest possible outer diameter diameter, so as not to impede the ability of the grinder to get as close as possible to the edge of the work. Likewise, the weights might be sculpted out at 9 o'clock and 3 o'clock, so that the operator can get their fingers inbetween the wieghts to remove each weight easily. Ideally, the weights would be 2.5 lbs, 5 lbs, and 10 lbs units.

The Frame itself would be custom built for each grinder that it can to receive a weighted system—each frame will have flush mounted bolts and be designed to be low profile so that the weight stack rides as low as possible . The frame will be designed so as not to block the motors on the grinders therefore allowing the units to vent properly and run at proper temperature. Also the frame will be fitted with the weight stem so that the stem is mounted on center over the axis of the motor which will, in turn, make the system run in balance, smooth and efficient .

Special tooling could be provided for sanding , grinding, and polishing, that can run at variable speeds, and work faster under the weighted system. This could include sanding paper or screens, diamond impregnated metal tooling for hard surface, and diamond impregnated resin bonded tooling for polishing hard surfaces.

Cases built custom to each different sized grinder, to include a place for the grinder the weights and the special tooling with any wrenches necessary to change out the tools. The cae might also include wheels and a dolly type handle to move the system around the jobsite. Ideally, the cases would be lockable, both to encloses the contents and to secure the whole case and contents from being stolen.

Also some type of a wheel or wheel might be provides to support the frame of the grinder and stability and agility, and reduce user fatigue.

CONCLUSION

This invention is a device and method for weighting and balancing ar hand-held electric angle grinder. A weight shaft is mounted on the frame of the angle grinder coaxially with the axis of rotation of the angle grinder motor. A selection of weights can be mounted on the weight shaft to provide extra downward pressure, through the motor and frame, to the grinding disc of the angle grinder. The weights are also selected to suppress vibration that is produced by the interaction between the grinding disc and the surface. As a result, the present invention provides an angle grinder that is easier and less exhaustingI to use, is less likely to have any harmful effects on the user, is able to provide a more effective functioning of the angle grinder, and is able to provide a treated work surface of better quality and less expense.

While the foregoing written description of the invention enables one of ordinary skill to make and use what is considered presently to be the best mode thereof, those of ordinary skill will understand and appreciate the existence of variations, combinations, and equivalents of the specific embodiment, method, and examples herein. The invention should therefore not be limited by the above described embodiment, method, and examples, but by all embodiments and methods within the scope and spirit of the invention.

It is obvious that minor changes may be made in the form and construction of the invention without departing from the material spirit thereof. It is not, however, desired to confine the invention to the exact form herein shown and described, but it is desired to include all such as properly come within the scope claimed.

The invention having been thus described, what is claimed as new and desire to secure by Letters Patent is:

Claims

1. An angle grinder, comprising:

a. an motor having a working end and an upper end, and having an axis of rotation, and

b. a removable weight mounted adjacent the upper end of the motor and around the axis of rotation.

2. An angle grinder as recited in claim 1, wherein the center of mass is on the axis of rotation to suppress vibration of the angle grinder when the angle grinder is is in use.

3. An angle grinder as recited in claim 1, wherein the center of mass is sufficiently close to the axis of rotation to suppress vibration of the angle grinder when the angel grinder is is in use.

4. An angle grinder as recited in claim 1, wherein the position of the weight on the grinder is adapted to apply downward pressure to the motor.

5. An angle grinder as recited in claim 1, wherein the position of the weight on the grinder is adapted to suppress vibration of the angle grinder during operation.

6. An angle grinder, as recited in claim 1, wherein the position of the weight on the grinder is adapted to apply downward pressure to the motor, and adapted to suppress vibration of the angle grinder during operation.

7. An angle grinder as recited in claim 1, wherein the removable weight has a center of mass, and when mounted on the angle grinder, has its center of mass adjacent the axis of rotation of the motor.

8. An angle grinder as recited in claim 1, wherein the removable weight has a center of mass, and when mounted on the angle grinder, has its center of mass adjacent the axis of rotation of the motor, and the weight is symmetrical about the axis of rotation.

9. An angle grinder as recited in claim 1, wherein the grinder has a weight shaft and the removable weight can be mounted on the weight shaft.

10. An angle grinder as recited in claim 1, wherein the grinder has a bracket removably mounted it and a weight shaft mounted on the weight bracket.

11. An angle grinder as recited in claim 1, wherein the grinder has a bracket removably mounted it, a weight shaft mounted on the weight bracket, and a removable weight mounted on the weight shaft.

12. An angle grinder as recited in claim 1, wherein the grinder has a weight shaft co-axial to the axis of rotation, and the removable weight can be mounted on the weight shaft.

13. A weight having a center of mass, the weight being removably mounted on an angle grinder, said angle grinder having an electric motor with an axis of rotation, so that the center of mass of the weight is located adjacent the axis of rotation of the motor, thereby selectively adding weight through the axis of rotation and suppressing vibration of the angle grinder.

14. A weight as recited in claim 13, wherein the center of mass is on the the axis of rotation to suppress vibration of the angle grinder when the angel grinder is is in use.

15. A weight as recited in claim 13, wherein the center of mass is sufficiently close to the axis of rotation to suppress vibration of the angle grinder when the angel grinder is is in use.

16. An accessory for an angle grinder for treating surfaces, the angle grinder including a frame elongated along a frame axis, a motor mounted in the frame, and having a rotatable motor shaft that rotates about a motor axis that is perpendicular to the frame axis, the accessory comprising,

a. weight bracket, mountable to the frame of the angle grinder,

b. a weight shaft mountable on the weight bracket, and coaxial with the motor axis, and

c. a weight mountable on the weight shaft, and adapted to provide downward pressure on the frame.

17. An accessory for an angle grinder, as recited in claim 12, wherein the weight is adapted to suppress vibration of the angle grinder.