US2457156A

US2457156A - Method of manufacturing diamond studded tools

Info

Publication number: US2457156A
Application number: US640939A
Authority: US
Inventors: Jones John Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 1946-01-12
Filing date: 1946-01-12
Publication date: 1948-12-28
Anticipated expiration: 1965-12-28

Description

Dec. 28, 1948. p JONES METHOD OF MANUFACTURING DIAMOND STUDDED TOOLS F iledJan. 12, 1946 Patented Dec. 28, 1948 UNITED STATES PATENT OFFICE METHOD OF MANUFACTURING DIAMOND STUDDED TOOLS John Paul Jones, Toronto, Ontario, Canada Application January 12, 1946, Serial No. 640,939 3 Claims. (Cl. 51-309) This invention relates particularly to the method by means of which the small diamond particles are embedded in the metal tool body and the principal object of the invention is to effectively hold the diamond particles within the small placement cavities in the surface of a ceramic mould while the metal of which the tool body is formed is being cast in said mould to imbed the diamond particles from subsequent displacement in the operative use of the tool.

A further object is to accomplish the desired result in a simple and inexpensive manner.

The principal feature of the invention consists in the novel method of securing diamond particles partly' embedded within placing cavities in the surface of a mould by efiecting adhesion of the particles to the mould through the fusion of a medium which will adhere to the mould surface and the surface of the diamond and will withstand the eiiort of a body of molten metal poured into the mould to displace the diamond particles from their placing cavities in the mould and hold such particles embedded in the metal poured into the mould until such molten metal will have securely and permanently embraced a portion of each of the diamond particles.

In the manufacture of diamond studded tools it has been the practice to form moulds, for the casting of molten metal to form a tool head, of a ceramic material and the particles of diamond have been partly embedded in the ceramic.

Owing to the fact that it is undesirable to subject the diamond to the temperature required for firing the ceramic to efiectively mould a molten metal, such moulds have been formed with placing cavities and the diamond particles have been secured in these cavities by adhesives of various kinds but it has been found that the heat of the molten metal poured into the mould destroys or renders these adhesives ineflective and the wash or flow of the molten metal displaces the diamond particles with the result that an undesirable percentage of the diamonds are lost in the cast metal, that is, they are not held on the surface in an effective cutting position.

The method herein set forth is illustrated in the accompanying drawings in which Figure 1 is an underside perspective view of a diamond drill for coring.

Figure 2 is a perspective view of the mould for forming the diamond studded end of the core drill.

view through the mould.

Figure 4 is a magnified sectional view of a portion of a mould showing a diamond coated and Figure 3 is an enlarged vertical mid-sectional ready to be embedded in an adhesive-coated positioning cavity.

Figure 5 shows the coated diamond inserted into an adhesive coated positioning cavity.

Figure 6 is a magnified sectional view of a portion of a mould showing a diamond secured in I its positioning cavities with the melted adhesive.

Figure 7 is a view similar to Figure 6 showing the metal of the tool head moulded around the portion of the diamond projecting beyond the mould cavity.

In carrying this invention into effect a mould of the desired shape and size is fashioned from a plastic ceramic which will withstand firing at a temperature higher than the melting tempera ture of the metal to be moulded therein to form the desired tool.

Such a mould l is illustrated in Figure 2 with an annular recess 2 formed therein when an annular type of bit is to be made. The inner walls of this recess 2 are provided with a multiplicity of small placing cavities 3 which may be formed by pressing or cutting the plastic ceramic material. The mould thus formed is then fired at a temperature preferably several hundred degrees above the temperature of the molten metal to be poured therein, say approximately 2150 F.

When the mould has cooled the surface of the cavities 3 is preferably brushed or otherwise coated with a thin coating l of a suitable ad hesive to provide a tacky surface.

The diamond particles ii which are to be used in the tool are then preferably dipped to coat a portion of the surface with a suitable tacky adhesive e and while the adhesive is tacky the diamond is dipped in a fine frit or powdered glass, thus applying a coating ll of such frit to a portion of the surface of the diamond. &

The frit covered portion of the diamond is then pressed into the adhesive coated placing cavity 3 and it is thus temporarily secured therein,

When all the placing cavities have been thus filled the mould is placed in a furnace and its temperature raised to a point which will dis sipate the temporary adhesive and fuse the int and bring it to a tacky state so that it will adhere strongly to the diamond surface and to the mould surface. Such temperature will be approximately 1550 F. which is sufliciently low to prevent reaction with the diamonds.

The heated mould is withdrawn from the furnace and the molten metal, which is to form the tool head, is poured into the mould at a temperature of approximately 1750 F.

The immediate application of this temperature from the molten metal to the mould, which is already heated to approximately 1550 F., efiects I the positioning cavities.

a further fusion of the glass and it acts as a tenacious temperature controlled adhesive to prevent the wash of the metal pouredv into the mould from displacing the diamond particles from The molten metal flows around the portions 8 of the diamonds protruding from the cavities 3 of the mould and it may partly enter the cavities but will not displace the fused frit adhesive from around the portion of the diamond embedded in the cavities.

Immediately the metal begins to cool it shrinks around the diamond particles which it has surrounded and thus permanently embeds such particles in the metal casting.

, In the process described each particle will be a high melting point and capable of assuming a firmly held in its proper position in the mould by the fused frit and be instantaneously embedded and sealed in the cast metal tool.

It will be readily understood that a process such as described may be put into effect without the use of special expensive tools and equipment.

The diamond particles have to be handled and placed in positioning cavities in any of the known methods and in the present method it is merely necessary for the operator to dip the diamond first in the adhesive then in the frit and then insert it in the positioning cavity which will have been adhesively coated separately.

Nothing further is required to hold the particles in the cavities. The original adhesive merely holds until the frit is fused to form the active adhesive and the taclw glass effectively resists the "was of the molten metal and as the metal cools insertingthe portions of the diamond particles it simultaneously forms the tool head and seals the cutting diamonds therein in proper operating location.

After the tool head is cast in the manner described the mould is simply broken away from the cast metal and it is then machined and fitted to the operative drilling tube, rod or other implement.

In the manufacture of certain classes of tools it may be found desirable to dispense with the use of the temporary adhesive by dusting or otherwise placing frit or powdered glass in the cavities and applying a temperature to the mould sufilcient to fuse the glass particles and insert the diamond particles into the cavities to be adhered to the fused material.

It may also be found feasible to use powdered metal as a fusible binder to hold the diamond particles in the mould.

In the use of any of the powdered fusible adhesives it may be found practical to spray or otherwise coat the mould surfaces with a temporary adhesive, then dust or otherwise apply the frit or other fusible adhesive to the adhesive surface and then the diamond particles may be inserted into the coated mould cavities.

What I claim as my invention is:

1. A method of manufacturing diamond studded tools consisting in preparing a mould with diamond placing cavities in its surface, positioning diamond particles in the cavities in said mould, packing powdered glass in said cavities around said diamonds, said diamond particles being arranged in the desired orientation in said I cavities to provide the correct cutting angles desired in the completed tool and being temporarily held in position by said powdered glass packing, raising the temperature of said mould to bring said glass to a tacky state to bond said diamonds in oriented position in said cavities, then moulding metal to form the tool around the exposed portion of the diamond particles to form a direct bond between the tool metal and the diamonds, then finally breaking away the mould and the glass.

2. A method of manufacturing diamond studded toolsconsisting in preparing a mould of a ceramic material and forming placing cavities in its surfaces, firing the mould, embedding diamond particles within said cavities and surround- .ing the embedded portions with a material having tacky condition in the transition from the solid to the liquid state, and leaving the unembedded portion of the diamonds free of said material, applying heat to the mould to raise said high melting point material to its tacky condition to adhere to the mould and to the diamonds, to hold same firmly embedded in oriented positions in said cavities, then moulding the tool forming metal around the unembedded portionsof the 'diamonds' to provide a direct bond between the diamonds and the tool metal, and finally breakin'g away the ceramic mould and the high melting point material.

. 3. A method of manufacturing diamond studded tools consisting in preparing a mould of a "ceramic material and forming placing cavities in its surfaces, applying a temporary tacky adhesive to the surface of the cavities, applying a temporary tacky adhesive to the diamond partito which said high melting point material has been applied into said cavities to contact the tacky adhesive therein, applying heat to dissipate the temporary adhesive. and raise said high melting point material to its tacky condition to adhere to the diamond particles and the mould, to hold same firmly embedded in oriented position in said mould cavities, moulding the tool forming metal in the mould to surround and embrace the portions of the diamond particles protruding from the cavities to provide a direct bond between the diamonds and the tool metal, and finally breaking away the ceramic mould.

7 JOHN PAUL JONES.

REFERENCES CITED The following references are UNITED STATES PATENTS Number Name Date 2,147,175 Rolland Feb. 14, 1939 2,147,843 Jamar et al Feb.' 21, 1939 2,187,384 Maier Jan. 16, 1940 2,299,207 Bevillard Oct. 20, 1942 2,319,331 Kurtz May 18, 1943 2,363,272 Taeyaerts et a1 Nov, 21, 1944 2,368,473 Keeleric Jan. 30, 1945 2,410,512 Lindquist et al. Nov. 5, 1946 FOREIGN PATENTS Number Country Date 526,241 Great Britain Sept. 13, 1940 556,007 Great Britain Sept. 16, 1943 JTHER REFERENCES