Title of Invention

POLISHING DISC APPARATUS AND A METHOD FOR POLISHING STONES

Abstract The polishing apparatus of the present invention comprises a stone polishing disc with a pair of base plates disposed in a hollow housing means. These base plates are operably connected to each other to form central and peripheral base plates. Each of these base plates is provided with a plurality of polishing means like bricks or abrasive pads. A hollow circular member disposed in the middle area of the central base plate, said member lock-integrated with the rotating shaft of said apparatus. An adjustable and replaceable hard bed disposed underneath the polishing disc to act as surface area for the selected stone. The smooth polishing of stones is performed placing the selected rough stone of suitable size on the soft bed for rough polishing, followed by edge-cutting. Subsequently, the edge-cut and roughpolished stone is placed on the hard bed for medium-polishing. Finally, soft-polishing is performed to . obtain smooth, planar and polished stone with sharp edges.
Full Text

AN APPARATUS AND A METHOD FOR POLISHING STONES Technical field
The present invention relates to an apparatus and a method for polishing stones. The present invention particularly relates to an apparatus with a polishing disc equipped with central and peripheral polishing bricks for polishing stones and a hard bed to act as surface for said stones while polishing. The present invention also relates to a method of polishing stones having stepped portions and perforated edges to provide smooth, planar and polished stones with sharp edges. Background and prior art
Any commercial, industrial or residential buildings have floors that are made up of stones or some other similar hard surface. Stones such as marble, Cuddapah Stones (Cuddapah is a name of a place in the State of Andhra Pradesh in India, which is famous for this type of slab stones) and granite are some examples of hard material that are commonly used for flooring. The stones used for flooring is polished either before or after laying of the stones.
In a conventional way of polishing stones, a rotary abrasive tool is used to polish a rough stone by placing the stone on a polishing bed. The polishing bed basically is a sand bed made of ordinary sand and covered by a gunny bag. The polishing machine having a polishing disc is placed on the stone for polishing. The polishing discs are of smaller diameters (approximately 10 Vi inches) with lesser number of polishing surfaces or pads or bricks embedded on them. The polishing disc of a polishing machined generally comprises five polishing bricks and the diameter of the polishing disc is approximately 10.5 inches. In order to obtain polished stones, generally three types of polishing abrasive pads or bricks are used depending upon the various stages of polishing. The first type polishing bricks or pads is used for the application of rough or initial polishing coat, a second type for the application of medium polishing coat and the third type for the application of final polishing coat. Once the polishing disc is placed on the rough stone to be polished, the first stage polishing or initial stage of polishing is performed which is referred to as rough coat. After the first rough coat is performed the polishing stones or bricks or pads are changed to apply the second polish, which is generally referred to as medium coat. Thereafter, the polishing stones are changed to provide a final coat which results in a smooth surface of the stone. Subsequent to the completion of all the three coats of polishing; finally the stone is edge-cut to the required size using an edge cutting machine.

However, by adopting the above known methods or machines it is not possible to obtain a polished stone with a perfectly levelled surface due to the uneven surface of the polishing bed, since the polishing bed is made of ordinary loose sand, which fails to maintain a perfectly levelled or planar surface not only due to the weight of the stone but also due to the continuous vibration of the machine. It is also difficult to obtain perfectly planar surfaces during polishing as resuh of the existence of unlevelled and stepped up regions on the back surface of the stones. In known methods, loose sand is used in the making of a polishing bed because loose sand held in gunny bag fills the gap of the unleveled stone back face, and thus helps to hold the stone firmly and prevents the breakage of the stone. However, the limitation is that the soft bed cannot stop the vibration of the stone. In order to prevent this vibration, if a harder plain or levelled surface is used instead of loose sand, the gap-filling on the back side of the stone will not occur and as a result the stone will vibrate even more than when used in bed made of loose sand resulting in breakage of the stone.
Therefore, laying of the stones (on site) the floor is not perfectly levelled resulting in the edges of the individual stones undulating. To overcome this disadvantage, the floor has to be repolished thereby increasing the expenses. The edges of the stone after edge-cutting using the conventional method are perforated edges and are not sharp edges. This results in a wide joint, which decreases the aesthetic look of the floor.
US5605493 depicts "Stone polishing apparatus and method" with a self-propelled battery operated stone floor polishing machine having dual rotating heads with detachable stone grinding, honing, and polishing pads. Objects of the invention
The primary object of the present invention is to provide an apparatus with central and peripheral polishing bricks or pads for polishing of stones.
An object of the present invention is to provide an apparatus with a hard bed disposed underneath the polishing disc to act as a hard surface area for the stones to be polished.
Another object of the present invention is to provide a method for polishing stones resulting in perfectly smooth, levelled and polished stones with sharp edges. Yet another object of the present invention is to provide an apparatus and a method to obtain polished stones ready for laying without requirement of additional polishing.

It is also an object of the present invention to provide an apparatus and method to
prevent breakage of stones during polishing.
Summary of the invention
The present invention provides an apparatus and a method of polishing stones
resulting in perfectly smooth, planar and polished stone with sharp edges. The
apparatus of the present invention comprises a stone polishing disc with a pair of base
plates disposed in a hollow housing means. These base plates are operably connected
to each other to form central and peripheral base plates. Each of these base plates is
provided with a plurality of polishing means in the form of stones, bricks or abrasive
pads. A hollow circular member disposed in the middle area of the central base plate
to act locking means with a rotating shaft of said apparatus. A variable size, adjustable
and replaceable hard bed or soft bed disposed underneath the polishing disc to act as
surface area for the selected stone. The present invention also provides a method for
smooth polishing of stones by using the apparatus of the present invention, wherein
the selected rough stone of suitable size is placed on the soft bed for rough polishing.
The rough-polished stone is edge-cut by means of an edge-cutting machine.
Subsequently, the edge-cut and rough-polished stone is placed on the hard bed for
medium-polishing. Finally, soft-polishing of the medium-polished stone is performed
to obtain smooth, planar and polished stone with sharp edges.
Brief description of the diagrams
Fig 1 depicts a polishing apparatus fitted with polishing disc of the present invention.
Fig 2 depicts the bottom view of the base plate unit having a plurality of polishing
stones or abrasive pads.
Fig 3 depicts a top view of the base plate.
Fig 4 depicts an adjustable hard bed to hold the stone during polishing.
Detailed description of the invention
The description of the invention is now made by referring to the accompanied
diagrams. It is noted, however that the appended drawings illustrate only typical
embodiment of this invention and is therefore not to be considered limiting of its
scope, for the invention may admit to other equally effective embodiments.
Referring initially to Fig 1, which depicts polishing apparatus of the present
invention. The polishing apparatus is run by an electrical motor (2). The rotary motion
of the electrical motor (2) is transmitted to the rotating shaft (8) through a pulley (3)
and a V-belt (4). The height of the polishing end of the machine is adjusted by means

of a screw (1) provided to adjust the height of the polishing apparatus. A power switch (5) is provided to control the turn-on or turn-off modes of the polishing apparatus. A handle (6) is provided to manoeuvre the polishing apparatus, to change the polishing disc and to hold the apparatus while polishing is in progress. The bottom end of the rotating shaft (8) with a hole at the center is provided for an easy flow of water and also the place to attach polishing disc. A water supply pipe (7) is provided to the apparatus to provide a constant water supply that is needed during the polishing process. A hook (9) is provided to hold the handle (6) of the polishing apparatus when the apparatus is not in use.
Now by specifically referring to Figs 2 & 3 in addition to Fig 1, the polishing apparatus of the present invention comprises a pair of base plates (10 & 12) equipped with a plurality of housing means. The housing means are in the form of hollow cavities. Said base plates (10 & 12) are operably connected to each other to form central (12) and peripheral base plates (10). A plurality of abrasive pads acting as polishing means (11) disposed within the hollow cavities of the peripheral and central base plates (10 & 12). In the present invention a suitable abrasive pads or stones used are for various stages of polishing (rough and smooth). The polishing means used in the apparatus of the present invention are polishing stones selected from emery coated bricks. The polishing means (11) are in the form of polishing stones that are substantially bean-shaped. However, it is within the purview of this invention to use any such compatible shapes such as triangle-shaped polishing stones. By adopting the apparatus of the present invention, stones of type natural stone, mosaic tiles (Mosaic tiles are made of cement and pieces of natural stones) can be used for polishing. The polishing means (11) of the peripheral base plate (10) are disposed with intervening gaps. A plurality of central polishing means, similar to that of the peripheral disposed inside the hollow housing of the central base plate (12). However, the central polishing means (13) are disposed without any intervening gaps among them. The size of the base plates can be adjusted according to the size of the stone to be polished. The diameter of the base plate (10) is about 17 inches, which can be varied subject to the size of a stone. The size of the base plate depends on the required size of the stone. If the size of the stone for instance is 10" x 10", a base having plate diameter of lO'^-lOVi" is used. For a bigger size of a stone, for example, between ir'xH" to 30x30*', a base plate of diameter ranging between 10-22" is used. A hollow circular member is disposed in the middle area of the central base plate (12) to

provide locking means. The locking means comprises a key way on the on the central base plate (12) which is lock-integrated with rotating shaft (8) of the polishing machine. Fig 3 shows the top view of the base plate (16) which is lock-integrated with the rotating shaft (8) of the polishing apparatus.
Fig 4 depicts a hard bed (14) that is used in the present invention to place the stone for polishing. The hard bed (14) is a metallic frame supported by vertical legs. This hard bed (14) is of a variable size and is adjustable. The hard bed (14) disposed in proximity to the polishing disc is used to place on it the selected stone for polishing. The size and shape of the variable hard bed (14) corresponds to the size and shape of the stone to be polished. The hard bed (14) consists of height-adjusting devices (15), such as air pressure devices and screw devices. These height-adjusting devices (15) are disposed on the four comers of the hard bed (14) to suitably adjust the height of the stone so that the surface level of the stone is even. In the present invention as an exemplary embodiment screw devices are used as height adjusting devices. However, it is within the purview of this invention to use any compatible height adjusting devices including air pressure devices for the adjusting the height of the hard bed (14). However, a conventional soft bed is used for initial polishing of the stone. In another embodiment of the present invention, a hard bed for polishing stones with uneven surfaces is adopted, said hard bed comprising; a metallic frame as means for disposing the stone to be polished, a plurality of vertical legs to support the metallic frame and a plurality of height adjusting members in the form of screw devices and air pressure devices disposed on said legs to adjust the height and the surface level of the stones.
The present invention also provides a method of smooth polishing of stones by using the apparatus of the present invention is disclosed. According to the method of the present invention, initially a rough stone of suitable size is selected which needs polishing. This stone (17) is first placed on the soft bed, which is a sand covered by a gunny bag (18). Most of the rough stone slabs (17) are generally not fully leveled in either the front or the back side, due to their natural occurrence. If the upper surface of the stone needs to be approximately leveled, an adjustment has to be provided at the back of the stone. Therefore a soft bed (19) is used. After placing on the soft bed initial rough polishing of the stone is done by selectively using the abrasive pads of the polishing apparatus.

In an embodiment of the present invention the peripheral and central polishing bricks
are emery coated.
In another embodiment of the present invention said emery coated bricks are bean-shaped or triangle-shaped, preferably bean-shaped.
In yet another embodiment of the present invention said peripheral polishing bricks are disposed with intervening gaps. In further embodiment of the present invention the soft bed is a sand covered with a
gunny bag.
In yet another embodiment of the present invention, the size and shape of the variable hard bed corresponds to the size and shape of the stone.
In still another embodiment of the present invention the hard bed consists of high-adjusting apparatus, preferably screws, disposed on the four comers of the hard bed to suitably adjust the height of the stone.
In yet another embodiment of the present invention, the size of the stone for polishing is in the range of IO"xlO"-30"x30".
The present invention also provides for a method of polishing stones using the apparatus of the present invention. Initially the edge-cutting of the rough-polished stones is performed using a conventional edge-cutting machine. This edge-cutting of the rough-polished stones results in razor-sharp edges of the stone. After edge-cutting, the edge-cut and rough polished stone is placed on the hard bed (14) of the apparatus of the present invention. The hard bed (14) has height adjusting devices (15) which are preferably screws are disposed to adjust the surface level of the stone and ensure vibration free polishing of the stone. A suitable air pressure device can also used in place of screws as height adjustment devices. The hard bed (14) is a metallic frame. The size and shape of the hard bed (14) is variable and corresponds to the size and shape of the stone. After placing the stone on the hard bed (14), a medium-polishing is performed on the edge-cut and rough-polished stone. This medium-polishing results in an edge-cut and medium polished stone. Thereafter a soft-polishing is performed on the edge-cut and medium-polished stone. This soft-polishing ultimately results in a smooth, even and polished stone with sharp edges.
While the above description constitutes the preferred embodiments of the present invention, it is to be appreciated that the invention is susceptible to modification, variation and change without departing from the proper scope and fair meaning of the accompanying claims.

Advantages
1. No further polishing of stones is required after the laying of the stones on the surface.
2. The edges of the stone by adopting the method of the present invention are sharp and as a result of that the joints between adjacent slabs will be very thin.
3. The method of the present invention prevents the breakage of stones during polishing.



I claim,
1. A polishing disc apparatus of a stone polishing machine, for rendering stones with sharp edges and planar surfaces, said apparatus comprising; a pair of base plates disposed in a housing means, said base plates operably connected to each other to form central and peripheral base plates, a plurality of peripheral polishing bricks, said bricks disposed inside the housing of the peripheral base plates, a plurality of central polishing bricks, said central polishing means disposed inside the housing of the central base plate, a hollow circular member disposed in the middle area of the central base plate, said base plate is lock-integrated with rotating shaft of the apparatus, and a variable size, adjustable and replaceable hard bed disposed in proximity to the said polishing disc to dispose the stone selected for polishing.
2. The apparatus as claimed in claim 1, wherein the housing means are hollow cavities.
3. The apparatus as claimed in claim 1, wherein the peripheral and central polishing bricks are emery coated.
4. The apparatus as claimed in claim 3, wherein said peripheral and central bricks are bean-shaped or triangle-shaped, preferably bean-shaped.
5. The apparatus as claimed in claim 3, wherein said peripheral polishing bricks are disposed with intervening gaps.
6. The apparatus as claimed in claim 3, wherein said central polishing bricks are disposed without any intervening gaps.
7. The apparatus as claimed in claim 1, wherein the hard bed is a metallic frame supported by vertical legs.
8. The apparatus as claimed in claim 7, wherein the size and shape of the variable hard bed corresponds to the size and shape of the stone.
9. The apparatus as claimed in claim 7, wherein said hard bed consists of high-adjusting members, disposed on the four comers of the hard bed to suitably adjust the height of the stone.
10. The apparatus as claimed in claim 9, wherein the height adjusting members are selected from screw devices or air pressure devices, preferably screw devices.
11. The apparatus as claimed in claim 1, wherein the size of the stone for polishing is in the range of 10"xl0"-30"x30".
12. A hard bed for polishing stones with uneven surfaces, said bed comprising; a metallic frame as means for disposing the stone to be polished, a plurality of

vertical legs to support the metallic frame and a plurality of height adjusting members disposed on said legs to adjust the height and the surface level of the stones.
13. The hard bed as claimed in claim 12, wherein the size of the metallic frame is in
the range of 10'xlO"-30"x30"(inches).
14. The hard bed as claimed in claim 12, wherein the height adjusting members are
selected from screw devices or air pressure devices, preferably screw devices.
15. The hard bed as claimed in claim 14, wherein the height adjusting members are
disposed on the four comers of the metallic frame.
16. A method for smooth polishing of stones by using the apparatus as claimed in
claim 1, said method comprising the steps of; selecting and placing a rough stone
of suitable size to be polished, rough-polishing said stone, edge-cutting the rough-
polished stone by means of an edge-cutting machine, placing the edge-cut and
rough-polished stone on the hard bed, medium-polishing rough-polished stone,
and soft-polishing the medium-polished stone to obtain smooth, even and polished
stone with sharp edges.
17. The method as claimed in claim 16, wherein edge-cutting is performed after the step of rough-polishing to obtain razor-sharp edges.
18. The method as claimed in claim 16, wherein the hard bed is a metallic frame.
19. The method as claimed in claim 16, wherein the size and shape of the variable
hard bed corresponds to the size and shape of the stone.
20. The method as claimed in claim 16, wherein said hard bed consists of height -
adjusting means, preferably screws, disposed on the four comers of the hard bed
to suitably adjust the height of the stone.
21. The method as claimed in claim 16, wherein the size of the stone is in the range of
10"xlO""30"x30".


Documents:

918-che-2004-abstract.pdf

918-che-2004-claims faild.pdf

918-che-2004-claims grand.pdf

918-che-2004-correspondnece-others.pdf

918-che-2004-correspondnece-po.pdf

918-che-2004-description(complete) faild.pdf

918-che-2004-description(complete) grand.pdf

918-che-2004-drawings.pdf

918-che-2004-form 1.pdf

918-che-2004-form 26.pdf

918-che-2004-form 3.pdf

918-che-2004-form 5.pdf


Patent Number 209587
Indian Patent Application Number 918/CHE/2004
PG Journal Number 50/2007
Publication Date 14-Dec-2007
Grant Date 05-Sep-2007
Date of Filing 13-Sep-2004
Name of Patentee M/S. NAGRAJ MUNDARGI
Applicant Address C/O Mr. S. B. KUDALGOUDER, H. NO. 41, IDEAL HOUSING SOCIETY, ADHYAPAK NAGAR, VISHWESHWAR NAGAR, HUBLI - 580 032
Inventors:
# Inventor's Name Inventor's Address
1 MR. NAGRAJ MUNDARGI C/O Mr. S. B. KUDALGOUDER, H. NO. 41, IDEAL HOUSING SOCIETY, ADHYAPAK NAGAR, VISHWESHWAR NAGAR, HUBLI - 580 032,
PCT International Classification Number B24 B 7/22
PCT International Application Number N/A
PCT International Filing date
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 NA