CLIAMS:I Claim,
1. An abrasive wire saw bead comprising;
a metal matrix (2) configured for anchoring an abrasive diamond grits (1) and a plurality of the abrasive diamond grits (1) each firmly anchored in the metal matrix.
2. The abrasive wire saw bead as claimed in claim 1, wherein the abrasive diamond grits (1) impregnated on the surface of the metal matrix (2) in which the maximum diamond grits (1) positioned in a way that flat portion of the diamond grits (1) maintains a leading edge of 60° angle with work piece configured to provide fast and efficient cutting.
3. An apparatus for manufacturing wire saw beads mainly comprises a fixed copper shaft (11), a horizontally movable copper shaft (12), a pair of pressure rolls (14) rotatable by the adjacent shafts (15), a diamonds grits flow unit (19) and an resistance heating unit (17) through which heat is passed to both copper shaft (11, 12) to tungsten tip (13);
wherein said each copper shaft (11,12) has a tungsten tip (13) attached at one end and are placed horizontally to face the tungsten tip ends (13) each other;
wherein each said tungsten tip (13) has tapered point (20) for locking the matrix cylinder (2) during the operation;
wherein each copper shaft (11,12) with tungsten tip (13) works as an electrode;
wherein said pressure rolls (14) are placed facing each other and rotatable with help of adjacent shafts (15) and makes contact with periphery of the matrix cylinder (2) which is mounted on the tapered point (20) on the tungsten tips (13);
wherein said diamond grits flow unit (19) carries industrial synthetic diamond grits (1).
4. A method for preparing abrasive wire saw beads comprising steps of;
a. placing and locking the matrix cylinder (2) between the tungsten tips (13) of copper shafts (11,12);
b. heating the matrix cylinder (2) at 600-900°C temperature;
c. flowing of diamond grits (1) from the diamond grits flow unit (19) on the matrix cylinder (2),
d. forming a layer on the metal matrix having an abrasive diamond grits (1) distributed on the matrix cylinder (2);
e. pressing the abrasive diamond grits (1) on the periphery of the matrix cylinder (2) by the pressure rolls (14).
5. The method for preparing abrasive wire saw beads as claimed in claim 4, wherein further rolling is done by pressure rolls (14) to fill the space left around the grits (1).

Dated this on 21st April, 2014
,TagSPECI: FORM 2
THE PATENT ACT 1970
(39 of 1970)
&
The Patents Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

1. TITLE OF THE INVENTION:
An abrasive wire saw bead and apparatus for manufacturing the same
2. APPLICANT:
1. (a) NAME : Dobariya Rajesh Manubhai
(b) NATIONALITY : An Indian
(c) ADDRESS : Village: Gigasan, Nishalpara
Taluka: Dhari,
District:Amreli
Pincode: 365640
Gujarat, India

3. PREMABLE TO THE DESCRIPTION
þ COMPLETE

The following specification particularly describes the invention and the manner in which it is to be performed.

The present invention relates to an abrasive wire saw bead having an abrasive impregnated segment and apparatus for manufacturing the same. More particularly, the present invention relates to a wire saw bead wherein the diamond particles are distributed in a metal matrix by using pressured rolling in order to provide efficient cutting, high wear resistance and long life for a bead.

BACKGROUND OF INVENTION:

The digging of natural work pieces like marble, lime work piece or granite as well as the processing of concrete or masonry requires diamond beads, which match the interaction of the bead and work piece, however, it is very difficult procedure. Mining industries commonly use a wire saw to cut hard work piece into large blocks that can then be shipped to processing plants to be further refined. These wire saws contain diamond-impregnated beads positioned on a cable.
Diamond beads are indispensable while other material lacks strength and durability to be substitute. Despite the tremendous improvements which diamond has provided for cutting, drilling and grinding beads, there are still several disadvantages which, if overcome, would greatly improve performance of the beads, and/or reduce their cost. For example, the abrasive diamond particles are not distributed uniformly in the matrix that holds them in place. As a result, the abrasive diamond particles are not positioned to maximize efficiency for cutting, drilling, etc. Despite of this also engraving of diamond particles in metal bead is also a critical technique and also diamond may not be positioned properly.
For coating of such diamond particles there are different techniques available that include sintering and electroplating. Sintering is the most frequent technique used for making wire saw beads. In sintering metal powder (iron, bronze, copper, nickel, chromium, cobalt tungsten etc.) are mixed with diamond grits. After that granulation of such powder has been made and then that mixture is coated on a metal bead first by cold pressing by using die or punch and then sintering hot pressing. This process needs high men power as well as this is very costly because of use of different metal powders and graphite blocks.
Drawback of sintered diamond beads is that the abrasive diamond particles or "grits" are inadequately attached to the bead substrate, or matrix support material due to which the cutting, drilling, polishing, etc., is affected. In fact, in most cases, diamond grits are merely mechanically coated in the matrix support material. As a result, diamond grits are often knocked off or pulled out prematurely. Hence, the diamond particles may be shattered by the impact of the bead when used to cut the work piece. Also due to high temperature and long heating time or with other relevant reasons in some cases diamond grits gets oxidized and will no longer useful.
JP2000176737 discloses wire saw beads and manufacturing method to firmly stick an ultra abrasive grain layer to a sleeve by sticking the ring like ultra abrasive grain layer to the outer periphery of the cylindrical sleeve having multiple holes on the side face.
JP20040117457 discloses wire saw, wire saw beads and method of manufacturing again for cutting of reinforced concrete and a steel material wherein beads are provided by sintering temporary molds becoming a source of the abrasive grain annular bodies in its state.
None of above prior art solves the aforesaid problems and hence there is an instant need to provide such beads which firmly anchor diamond grits in the support matrix to provide efficient cutting, high wear resistance and long life for a bead.

OBJECT OF THE INVENTION

The main object of the present invention is to provide abrasive wire saw bead and apparatus for manufacturing the same.
Another object of the present invention is to provide improved cutting, sawing, or grinding characteristics without requiring an extra amount of abrasive grit to form the bead.
Yet another object of the present invention is to provide apparatus by which the diamond grits are anchored in the metal matrix in a way that provides efficient cutting edge, high wear resistance and long life for a bead.
Another object of the invention is to provide a wire saw bead having higher speed cutting and requires less energy and less manpower as compared to available conventional methods.

SUMMARY OF INVENTION

The present invention discloses a wire saw bead and apparatus for manufacturing the same wherein the bead comprises a firmly anchored abrasive diamond grits to provide efficient cutting edge. Particularly the present invention discloses a wire saw bead manufactured by pressured rolling. The apparatus for manufacturing wire saw beads mainly comprises a fixed copper shaft, a horizontally movable copper shaft, a pair of pressure rolls rotatable by the adjacent shafts, diamonds grits flow unit and an resistance heating unit. The wire saw beads give efficient cutting edge, high wear resistance, higher cutting speed, long life for a bead and requires less energy and manpower.

BRIEF DESCRIPTION OF DRAWING

Fig. 1 (a) shows perspective cross section diagram of wire saw cutting bead.
Fig. 1 (b) shows perspective cross sectional diagram of wire saw bead with slue.
Fig. 2 (a) shows perspective side view of wire saw cutting bead.
Fig.2 (b) shows perspective side view of wire saw bead with slue.
Fig. 3 (a) and Fig 3 (b) show stages of engraving of abrasive in a matrix material respectively.
Fig. 4 (a) shows side view of prior art wire saw bead included for comparison only and does not depict the present invention.
Fig. 4 (b) shows side view of present invention wire saw bead.
Fig. 4 (c) and Fig. 4 (d) shows sectional view and side view of the present invention respectively.
Fig. 5 (a) side view of prior art coated abrasive on metal matrix included for comparison only and does not depict the present invention.
Fig. 5 (b) side view of present invention engraved abrasive on metal matrix.
Fig. 6 (a) and Fig. 6 (b) shows prior art abrasive wire saw bead and present invention bead with respect to cutting edge angle respectively.
Fig. 7 (a) shows prior art abrasive wire saw bead and Fig. 7 (b) present invention bead with respect to exposed abrasive material edge for cutting.
Fig. 8 represents perspective view wire saw with bead.
Fig. 9 shows cross sectional view of apparatus for manufacturing the wire saw bead.
Fig. 10 cross sectional view of pressured rolling of abrasive material on a bead.
Hereinafter, an exemplary embodiment of the present invention will be described with reference to the accompanying drawings. In the following description, the same elements will be designated by the same reference numerals although they may be shown different in drawings. Further, in the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

DETAILED DESCRIPTION

Before explaining the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the construction and arrangement of parts illustrated in the accompany drawing. The invention is capable of other embodiments, as depicted in figure as described above and of being practiced or carried out in a variety of ways. It is to be understood that the phraseology and terminology employed herein is for the purpose of description and not of limitation.
A metal matrix configured for anchoring abrasive diamond grits (1) is prepared by using any of the conventional methods know in the art. There is no particular limitation of size and shape of metal matrix. For example, it can be cylindrical or cone shaped etc. A metal matrix preferably molded in cylindrical shape. Different metal compositions are used to make said metal matrix cylinder (2) by any of conventional method. Selection of metals is depended on the material which is required to be cut. The material is selected for matrix cylinder (2) is barring steel, carbon tool steel, high speed steel, hot work steel, non- shrinking dye steel, pneumatic steel, spring steel, constructional steel, alloy steel, high strength steel and stainless steel. This material mainly includes carbon, cobalt, manganese, tungsten, chromium and nickel to provide high wear resistant. However, there is no particular limitation on selection of material. Matrix cylinder optionally made from metal powder mixture such as iron, copper, copper alloys, cobalt, nickel, cobalt, tungsten etc. Also, different size of cylinder is selected. Generally 11 mm OD x 11 mm L size cylinder is preferable. There is no particular limitation to the method of manufacturing a cylinder (2) for use in the present invention, for example, can be cut to a suitable length or tubing metal in appropriate cylindrical shape and size. In accordance of the present invention in a cutting bead optionally slue (3) of other material is prepared in the inner radius of the metal cylinder (2) as per requirement.
Fig. 1 (a), shows perspective side view and cross sectional view of matrix cylinder (2) while Fig. 1 (b) shows side view and cross sectional view of the matrix cylinder (2) with slue (3). Same way Fig 2 (a) and (b) represents three dimensional front view of matrix cylinder (2) and matrix cylinder (2) with slue (3) respectively.
In the present invention industrial synthetic diamond grits that are available in the market are used. 0.25-0.5 mm hexagonal diamond grits (1) are generally used to make wire saw beads. Also size of the diamond grits (1) can be varying as per requirements. Anchored diamonds grits (1) gradually gets exposed over the surface thereby providing efficient cutting edges. To avoid oxidation of diamond grits (1) optionally titanium coated diamond grits are used. It is also known that because of high temperature and long time heating diamond grits get oxidized while in present invention heating is done for minimum time to overcome such difficulties.
Fig. 3 (a) shows perspective view of present invention diamond grit (1) in a primary stage of anchoring in to the matrix cylinder (2) for comparison. When the diamond grits (1) get settled on the outer periphery of matrix cylinder (2) about 0.06 mm- 0.12 mm space has been left. After pressured rolling and because of high temperature the matrix material become soft and rolling is done by pressure rolls (14) to fill the space resulted in to perfectly anchor diamond grit (1) as shown in Fig. 3 (b).
Fig. 4 (a) shows prior art coating of diamond grits (1) on the periphery of matrix cylinder (2) as metal powder bonded layer. The distribution and anchoring of diamond grits (1) on the periphery of matrix cylinder (2) determines the work performed by the wire saw bead. In Fig. 4 (a) of prior art diamond grits (2) are not positioned properly and because desired speed and cutting efficiency is not achieved. The anchoring achieved by the present invention process as shown in Fig 4 (b) the wire saw bead gives even anchoring of diamond grits into matrix cylinder (2). Fig. 4 (c) sectional view and Fig. 4 (d) shows top view showing engraved and anchored diamond grits (1) on the outer periphery of the cylinder (2).
In the present invention the periphery of the matrix cylinder (2) is engraved with diamond grit particles (1). In accordance with the present invention, a cutting surface is formed to resist premature wear to the sides of the bead, thereby extending the cutting bead’s useful life. Also chipping of the work piece is avoided.
As shown in Fig. 6 (a) diamond grits (1) engraved by prior art when to cut the work piece, the exposure maximum of grit make about 30° angle with cutting work piece (10). It is known in the art that for cutting, narrow angle results in slipping of work pieces which results in low speed. While in the present invention as shown in Fig. 6 (b) because of pressurized rolling and reference of pressure rolls diamond grits (1) are anchored in a way that create about angle 60° with work piece to provide high speed cutting.
Fig. 7 (a) and Fig. 7 (b) represent working of wire saw beads and particularly represent perspective use of wire saw bead. Fig. 7 (a) shows exposure of prior art coated diamond grits (1) on the bead after being used. In the prior art due to uneven coating positions, diamond grits (1) get exposed with random angle for cutting. While as shown in Fig. 7 (b) present invention anchoring provides firm impregnation that provides better exposure of diamond grits (1) to make better angle for cutting.
Fig. 8 represents a wire saw having plurality of wire saw beads in which beads are mounted in spaced apart from each other on the wire. The wire passes through the centre hole of each bead so that each bead completely surrounds the wire. Wire is selected as known in the art. Wire includes rubber plastic molding (22), inner wire rope with spring (21) and similar thereof wire.
Fig. 9 shows a cross sectional diagram of apparatus for manufacturing wire saw bead. An apparatus for manufacturing wire saw bead consists of a fixed rotatable copper shaft (11) having a tungsten tip (13) attached at one end, a horizontally movable rotatable copper shaft (12) having a tungsten tip (13) attached at one end, a pair of pressure rolls (14) each rotatable by the adjacent shaft (15), a diamonds grits flow unit (19) (not shown in figure) and an resistance heating unit (17) through which power is passed to both copper shaft (11, 12) to tungsten tip (13).
Said fixed copper shaft (11) and movable copper shaft (12) are placed so as to facing the tungsten tip ends (13) and rotates during the operation. The fixed copper shaft (11) tungsten tip (13) and movable copper shaft (12) tungsten tip (13) are arranged to place the matrix cylinder (2). The each copper shaft (11, 12) also works as an electrode. Each said copper shafts (11, 12) has centre hole (16) for cooling of the shaft during the operation. The copper shafts (11, 12) are connected with resistance heating unit (17). Each said tungsten tip (13) has tapered point (20) for locking the matrix cylinder (2) during the operation. The pressure rolls (14) are also placed facing each other and makes contact with periphery of matrix cylinder (2). The rotatable pressure rolls (14) are rotatable with help of adjacent shafts (15). Each said pressure rolls (14) are further processed to achieve required hardness by using any of conventional methods. The diamond grits flow unit (19) is filled with industrial synthetic diamond grits (1).
Fig. 10 shows side view of pressured engraving wherein said pair of pressure rolls (14) is rotated in clockwise direction and constant flow of diamond grits (1) are made on rotatable cylinder matrix (2).
In the working of the apparatus the matrix cylinder (2) is fixed between centre points of each tungsten tips (13). Current is passed from the resistance heating unit (17) through which due to electric resistance cylinder is heated up to 600-900 °C. Because of high temperature diameter of cylinder get increased and pressed between the pressure rolls (14). During the pressured rolling on heated matrix cylinder (2), diamond grits (1) are simultaneously drawn from diamond grits flow unit (19). The adjacent pressure rolls (14) press the diamond grits (1) on the outer surface on heated cylinder (2). Because of pressure flat portion of the grits get evenly anchored in the cylinder thereby providing constant engraving of diamond grits (1).
The present invention is intended for making metal bond abrasive beads containing evenly distributed diamond grits, which provides significant improvement over the beads that contains random and non-uniform distribution of grits. Because of single layer engraving of present invention bead gets longer life and high cutting speed. The present invention also provides easier and cost effective method for making wire saw beads.
Example 1
Wire saw beads for cutting marble were prepared by the present invention embodiment. Industrial synthetic diamond grits were used to form an abrasive layer on the wire saw beads. Where EN 31 barring steel was used to make metal matrix which contain composition as follows;
Type C % SI % Mn % Cr % W % V % Co %
Barring Steel (EN 31) (AISI 52100) 0.95/
1.20 0.10/ 3.35 0.30/ 0.75 1.00/ 1.60 S&P Each
(max) 0.025
Table 1: Composition of EN-31 AISI 52100
The matrix cylinder was heated and diamond grits were flowed on matrix cylinder. Pressured rolling was done to firmly anchor the diamond.
The engraved anchored diamonds grits (1) in the cylinder (2) was calculated by using below formula.
Total area of cylinder (2): OD x ? x L
11 x 3.14 x 11 = 379.94 ~ 380 mm2
Grit size= 45 mesh = 0.354 mm
Total are of a grit= L x W X H
0.354 x 0.354 x 0.354
Hence, only 0.354 L x 0.354 W area will be on outer surface of the cylinder (2).
Area of diamond grits on outer periphery = L x W x Pieces
= 0.354 x 0.354 x 1000
= 125 mm2
Total supporting area of cylinder= Total area of cylinder – area of Diamond
grits on outer periphery
= 380 – 125
= 255 mm2
Hence totally in 33% outer area of the cylinder (2) diamond grits (1) were engraved, where remaining 67% of matrix material holds the diamond grits (1).
Vision Inspection:
The vision inspection was performed to observe the coating done by prior art and present invention method engraving.
Result:
As shown in Fig 5 (a) prior art coating provides uneven engraving of the diamond grits (1) on matrix cylinder (2). While in the present invention as shown in Fig. 5 (b) flat portion of maximum diamond grits (1) is observed. Each of flat portions results providing better cutting edge over work piece.
While, the invention has been described with respect to the given embodiment, it will be appreciated that many variations, modifications and other applications of the invention may be made. However, it is to be expressly understood that such modifications and adaptations are within the scope of the present invention, as set forth in the following claims.