US3471975A - Surfacing wheel - Google Patents

Description

Oct. 14, 1969 c. w. HIGHBERG 3,471,975

SURFACING WHEEL Filed Jan. 12, 1967 2 Sheets-Sheet 1 CARLE w. HB

his ATTORNEYS oct. 14, 1969 c. w. HIGHBERG 8,411,915

SURFACING WHEEL 2 Sheets-Sheet 2 Filed Jan. 12 1967 E? 1 m FIG. 4 MQW LM his ATTORNEYS United States Patent SURFACING WHEEL Carle W. Highberg, Murray Hill, N.J., assignor to Engelhard Hanovia, Inc., Newark, N.J., a corporation of New Jersey Filed Jan. 12, 1967, Ser. No. 608,826 Int. Cl. B24d 7/06 US. Cl. 51204 19 Claims ABSTRACT OF THE DISCLOSURE A surfacing wheel having substantially coplanar, radially disposed, fixed abrasive contact areas for abrasively engaging fiat materials, such as sheets of plate glass, the configuration, relative size and arrangement of contact areas being of a predetermined manner and size to effect controlled successive surfacing operations.

The present invention relates to a surfacing wheel for surfacing flat materials such as sheets of glass and, more particularly, to novel and improved construction, configuration and arrangement of fixed abrasive contact areas therein for providing substantially improved surface quality and stability of operation.

As described in detail in my copending application, Ser. No. 417,065, filed Dec. 9, 1964, and my other earlier copending applications and patents referred to therein, much work has been ,done in recent years with respect to the surfacing of hard materials, such as flat sheets of glass and the like, to effect substantial reductions in capital equipment and operating costs, and substantial improvement in production quality through the use of surfacing apparatus employing bonded abrasive particles, such as I diamonds, of predetermined concentration and particle size, in accordance with the various methods, systems and techniques disclosed therein.

The continually increasing requirements and standards of competitive commercial production have necessitated a continued development and improvement of the surfacing techniques and apparatus, in particular the surfacing wheel, in order to obtain requisite improvement in surface quality and stability of operation, minimization of depth of fracture, and an increase in the production selection percentages of the product output of the surfacing operation.

Multi-section fixed abrasive grinding wheels have been developed having either fixed abrasive particles disposed in matrices of uniform concentration and particle size for specific grinding operations, or of progressively varying concentration and particle size in different annular portions of the contact surface of the grinding wheel. Such grinding wheels have the fixed abrasive contact areas positioned in annular zones about the axis of rotation of a substantially flat unitary surfacing wheel or disc, or have incorporated a plurality of distinct radial elements or smaller wheels in the form of a spider for grinding and polishing purposes.

The fine surfacing of materials conventionally involves a series of successive surfacing steps which may utilize abrasive materials of different particle sizes, concentrations or even different types. Surfacing apparatus and techniques satisfactory for one stage of the surfacing operation are not necessarily satisfactory for some other stage of the operation.

It has been found in actual practice with some types of broad rim wheels that while the surfacing wheels may be initially formed with substantially coplanar contact areas, the contact surfaces may naturally form during the breaking-in process an outer annular zone and an inner annular zone each diverging outwardly at a slight angle from the original plane of the wheel surface from a generally annular high point or ridge lying within the general contact zone and disposed radially about the axis of rotation. In the surfacing of sheets of plate glass, for example, as the glass is fed through the surfacing station in surfacing relation to the wheel, a first surfacing operation may be accomplished by the outer portion of the grinding wheel (the divergent inner portion not being in contact with the sheet of glass being surfaced). As the glass progresses past the axis of rotation of the surfacing wheel, it comes in contact with the inner portion of the surfacing wheel (the divergent outer portion not being in contact with the sheet of glass being surfaced). For certain surfacing operations, such as the later grinding or polishing stages, earlier forms of multi-section wheels having uniform concentrations and size of abrasive particles within each of the respective annular zones, and spider wheels having contact areas with uniform concentration and size of abrasive particles, were found to have insufficient glass removal (irrespective of the pressure on the wheel), to be very unstable from a production point of view in that there would be occasional excessive glass removal, or subject to periodic wheel burning which would render the glass unuseable.

In accordance with the invention, a novel and improved surfacing or grinding wheel is provided, comprising a plurality of satellite surfacing means (either the contact surfaces or radially disposed spider elements or radially disposed distinct sectors in a solid wheel), the contact element of each of the satellite surfacing means having a predetermined outer portion and a predetermined inner portion lying respectively in concentric outer and inner annular zones about the axis of rotation.

In a preferred embodiment, the total engageable area of all of the contact element inner portions relative to the total area of the inner annular zone is of a greater proportion than the total engageable area of all of the contact element outer portions relative to the total area of the outer annular zone, the total engageable area of all the contact element inner portions being greater than the total engageable area of all of the contact element outer portions.

In accordance with a further feature of the invention, at least one of the inner and outer contact element portions of each of the satellite surfacing means may have a plurality of distinct adjacent contact areas of different abrasive characteristics disposed at least in part at equal radial distances from the axis of rotation for sequentially engaging the material to be surfaced to provide interplay of the adjacent contact areas in the surfacing operation.

For a more complete understanding of the invention, reference may be had to the following detailed description taken in conjunction with the figures of the accompanying drawings, in which:

FIGURE 1 is a schematic representation of an exemplary embodiment of a surfacing wheel having a plurality of satellite surfacing means in engagement with a sheet of flat material, in accordance with the invention;

FIG. 2 is an exaggerated side elevation in cross section of the surfacing wheel and sheet of flat material of FIG. 1, taken along the lines 22 and looking in the ,direction of the arrows;

FIG. 3 is a schematic representation of the contact area surface of one of the satellite surfacing means of FIG. 1;

FIG. 4 is a partial broken-away side elevation of the satellite surfacing means of FIG. 3 disclosing the spaced apart discrete pellets forming the contact elements of the surfacing wheel; and

FIG. 5 is a perspective view of an alternate embodiment of a substantially flat, unitary surfacing wheel hav- 3 ing a plurality of radially disposed satellite means, in accordance with the invention.

In FIGS. 1 and 2, a surfacing Wheel 10, including five separate satellite surfacing means 11 adapted to be rotatahly driven about an axis of rotaton 12 and disposed in different respective sectors in the form of a spider wheel, is suitably positioned in surfacing engagement with the surface of a flat sheet of material 14, such as a sheet of plate glass, which may be relatively and cooperatively moved in a predetermined directional sense through the surfacing station including the surfacing Wheel 10 in a plane transverse to the axis of rotation 12. The satellite surfacing means 11 are each suitably mounted on the conventional support structure of the surfacing wheel 10 in a relatively nonrotatable manner, i.e. not rotatable about their own centers but adapted as a composite unit to rotate about the axis of rotation 12.

When the surfacing wheel 10 is broken-in, an annular high point or ridge 15 is formed on the otherwise substantially coplanar contact element surfaces of each of the satellite surfacing means 11 to divide the contact element of each of the satellite surfacing means 11 into a predetermined outer portion 16 and an inner portion 17 lying respectively in concentric inner and outer annular zones 18 and 19 about the axis of rotation 12. The contact element of each of the satellite surfacing means 11 (as shown in FIG. 3) comprises a generally circular arrangement of pie-shaped sections 2127, inelusive, disposed radially about a center point 28, the center points 28 of all of the satellite surfacing means 11 being equidistantly spaced apart from each other and also radially equidistantly spaced from the axis of rotation 12 of the surfacing wheel 10.

The engageable area of the contact elements of the satellite surface means 11 are formed by the substantially coplanar exposed outer surfaces 30 of a plurality of spaced-apart discrete pellets 31 (FIGS. 3 and 4) which may be any type of suitable metallic or resinoid matrix in which abrasive particles such as diamond particles may be fixedly bonded in respective predetermined concentrations, the diamond particles being of predetermined particle size or within a predetermined range of particle sizes. The discrete pellets 31 are suitably mounted on or attached to a backplate 32 of the satellite surfacing means 11. The spacing between the pellets 31 (which may be of any suitable configuration, but preferably cylindrical) is of a magnitude such as to facilitate the distribution of conventional coolant flow generally radially outward across the contact element of the satellite surfacing means 11 from any suitable conventional source, preferably located in the center portion of the surfacing wheel 10.

Each of the six pie-shaped sections 21-26 are preferably 45 sections, with the section 27 being a 90 section. The contact surface area of the 90 section 27 is arcuately truncated along the line 34 relative to the axis of rotation 12. As shown in FIG. 3, the backplate 32 of the 90 section 27 extends inwardly toward the axis of rotation 12 to form a pocket between the line 34 and the generally circular boundary of the satellite surfacing means 11, which does not contain pellets 31, but which serves to collect and facilitate the distribution of lubricant or coolant across the face of the contact area.

In an exemplary embodiment of the invention, the pellets 31 forming the 90 section 27 contain abrasive particles such as diamonds of predetermined particle size (e.g. in the order of to 30 microns) in a first predetermined concentration C (e.g. 2.1 carats per cubic inch). The pellets 31 of the sections 25 and 26 contain abrasive particles in a second and lesser predetermined concentration C (e.g. 1.7 carats per cubic inch). The pellets 31 in the remaining sections 21-24, inclusive,

contain abrasive particles in a third and still lower concentration C (e.g. 1.3 carats per cubic inch).

Since the satellite surfacing means 11 are relatively non-rotatable about their center points 28, a plurality of concentric annular zones I (including only parts of sections 21 through 24), II (portions of sections 21 and 24, as well as sections 25 and 26), III (portions of sections 25 and 26), IV (portions of sections 25, 26 and 27), and V (only portions of section 27) are determinable as being radially located about the axis of rotation 12. From an ispection of FIG. 3, it is readily apparent that the portions of the contact element of each of the satellite surfacing means 11 by lying within the respec tive annular zones I-V are in a predetermined progressively varying concentraton relation, as seen in the table.

TABLE Concentric annular zone: Effective concentration I C II C -i-C III C IV C +C V C In the alternate embodiment of FIG. 5, a substantially flat, unitary surfacing wheel 40 adapted to be rotatably driven in any conventional manner about an axis of rotation contains a plurality of integral satellite surfacing means 41 constituting raised portions having coplanar contact elements, which function in the same manner as the spider wheel 10 of FIGS. 1 and 2.

In operation, with the sheet of fiat material 14 being fed in the direction of the arrows in FIGS. 1 and 2, the flat material first comes into abrasive engagement with the outer portion 16 of each of the respective satellite surfacing means 11 as they pass transversely across the surface of the material 14 (see FIG. 2.). At that point of engagement, the inner portion 17 of the contact element of the satellite surfacing means 11 is not in engagement with the material 14. Thus a first surfacing operation is performed by the abrasive particles in pellets 31 lying in zone I, of a concentration C The sheet of material 14 then passes through the axis of rotation 12 and comes into abrasive contact with the inner portion 17 of the contact element of the satellite surfacing means 11 as it traverses the sheet of material 14. As the material first comes in contact with the inner portion 17 approximately at the arcuate line 34, it is engaged by the abrasive particles in zone V of the highest concentration. As it continues to move in the direction of the arrows in FIGS. 1 and 2, the material 14 comes under the influence of the pellets 31 lying in zone IV and is sequentially moved across the radial extent of zone IV. In this manner the material 14 comes into contact with more and more pellets 31 of the sections 25 and 26 (concentration C and progressively less of the pellets 31 in the section 27 (concentration C The material 14 then progressively passes through zones III, II and probably a part of I before losing contact with the satellite surfacing means 11 at the annular ridge or high point 15. Thus a second surfacing operation of a substantially different character is accomplished by the inner portion 17 of each of the satellite surfacing means 11.

During the first surfacing operation, the surfacing wheel 10 primarily provides a cutting function, progressively bringing more abrasive material of uniform concentration and particle size into play as the material 14 moves across the outer portion 16.

In the second surfacing operation, in addition to a cutting action, i.e. glass removal, the surface quality is improved by equal or greater abrasive particle (diamond) impingement on the material being surfaced as it advances across the inner portion 17. Such abrasive particle impingement is produced by the interplay of pellets having abrasive particles of materially different concentration in adjacent sections at equal radial distances from the axis of rotation 12. As the effective concentration decreases, the number of pellets engaged increases.

Thus there is provided in accordance with the invention a novel and substantially improved construction of surfacing wheel having a plurality of distinct surfacing contact areas which are progressively brought into abrasive contact with the material to be surfaced in a unique predetermined manner.

It will be understood by those skilled in the art that the above described embodiments are meant to be merely exemplary and that they are susceptible of modification and variation without departing from the spirit and scope of the invention. For example, instead of the exemplary pieshaped areas of the contact element of the satellite surfacing means, the abrasive contact areas may be of any other suitable shape whereby a controlled variable surfacing operation is accomplished. The spider elements while relatively non-rotatable with respect to the axis of rotation of the overall surfacing wheel may be either rigid or individually tiltable, so as to conform more readily to the work surface. Therefore, the invention is not deemed to be limited except as defined in the appended claims.

I claim:

1. A surfacing wheel for surfacing flat materials adapted to be rotatably driven about an axis of rotation, the surfacing wheel and the material to be surfaced being relatively and cooperatively movable in a predetermined directional sense in a plane transverse to the axis of rotation to facilitate surfacing of the material, comprising a plurality of satellite surfacing means having substantially coplanar contact elements adapted to abrasively engage the material to be surfaced and being radially disposed about the axis of rotation in different respective sectors and spaced apart from each other and the axis of rotation, said contact element of each of said satellite surfacing means having a predetermined outer portion and a predetermined inner portion lying respectively in concentric outer and inner annular zones about the axis of rotation, the total engageable area of all of said contact element inner portions relative to the total area of said inner annular zone being of a greater proportion than the total engageable area of all of said contact element outer portions relative to the total area of said outer annular zone, the total engageable area of all of said contact element inner portions being greater than the total engageable area of all of said contact element outer portions, said satellite surfacing means outer portions being adapted to abrasively engage the material to be surfaced as that material first passes under the surfacing wheel for performing a first surfacing operation upon the material, said satellite surfacing means inner portions being adapted to abrasively engage the material to be surfaced after that material successively passes through the axis of rotation for performing a further surfacing operation upon the material.

2. A surfacing wheel as claimed in claim 1, each of said satellite contact elements having abrasive particles of predetermined particle size fixedly bonded therein in respective predetermined concentrations.

3. A surfacing wheel as claimed in claim 2, wherein said abrasive particles are diamond particles.

4. A surfacing wheel as claimed in claim 1, each of said satellite contact elements comprising a plurality of spacedapart discrete pellets composed of diamond particles of predetermined concentration and particle size fixedly bonded in a matrix.

5. A surfacing wheel as claimed in claim 1, said satellite surfacing means being relatively non-rotationally mounted on a common carrier means.

6. A surfacing wheel as claimed in claim 1, said satellite surfacing means comprising relatively non-rotatable radial elements in the form of a spider wheel.

7. A surfacing wheel as claimed in claim 1, said satellite surfacing means constituting predetermined portions of a substantially flat, unitary surfacing wheel.

8. A surfacing wheel as claimed in claim 1, wherein each of said satellite surfacing means contact elements is a generally circular arrangement of relatively nonrotatable generally pie-shaped sections disposed about a respective center point radially spaced equidistant from the axis of rotation of the surfacing wheel.

9. A surfacing wheel as claimed in claim 8, wherein at least the radially innermost one of said pie-shaped sections of each of said satellite contact elements is arcuately truncated relative to the axis of rotation.

10. A surfacing wheel for surfacing flat materials adapted to be rotatably driven about an axis of rotation, the surfacing wheel and the material to be surfaced being relatively and cooperatively movable in a predetermined directional sense in a plane transverse to the axis of rotation to facilitate surfacing of the material, comprising a plurality of satellite surfacing means having substantially coplanar contact elements adapted to abrasively engage the material to be surfaced and being radially disposed about the axis of rotation in different respective sectors and spaced apart from each other and the axis of rotation, said contact element of each of said satellite surfacing means having a predetermined outer portion and a predetermined inner portion lying respectively in concentric outer and inner annular zones about the axis of rotation, at least one of said inner and outer contact element portions of each of said satellite surfacing means having a plurality of distinct adjacent contact areas of different abrasive characteristics disposed at least in part at equal radial distances from the axis of rotation for sequentially engaging the material to be surfaced to provide interplay of said adjacent contact areas in the surfacing operation.

11. A surfacing wheel as claimed in claim 10, wherein said distinct adjacent contact areas respectively have materially different concentrations of abrasive particles.

12. A surfacing Wheel as claimed in claim 10, wherein each of said satellite surfacing means contact elements is a generally circular arrangement of relatively non-rotatable generally pie-shaped sections disposed about a respective center point radially spaced equidistant from the axis of rotation of the surfacing wheel.

13. A surfacing wheel as claimed in claim 12, wherein at least the radially innermost one of said pie-shaped sections of each of said satellite contact elements is arcuately truncated.

14. A surfacing wheel as claimed in claim 10, wherein the surfacing wheel is in the form of a spider wheel and each of said satellite surfacing means comprises a relatively non-rotatable radial element thereof, said satellite surfacing means contact element having a plurality of non-rotatable generally pie-shaped sections disposed in a generally circular arrangement about a center point radially spaced from the surfacing wheel axis of rotation, at least the radially innermost one of said pieshaped sections being arcuately truncated on an are spaced a predetermined radial distance from and about the axis of rotation, all of the remaining ones of said pie-shaped sections being radially spaced from the axis of rotation by at least a distance equal to said predetermined radial distance, at least the radially innermost one of said arcuately truncated sections having diamond particles fixedly bonded therein of a first predetermined concentration, adjacent ones of said pie-shaped sections having portions radially equidistant from the axis of rotation with portions of said arcuately truncated sections with diamond particles of said first predetermined concentration having diamond particles fixedly bonded therein of a second predetermined concentration materially different from said first predetermined concentration.

15. A surfacing wheel as claimed in claim 14, wherein said first predetermined concentration is greater than said second predetermined concentration.

16. A surfacing wheel as claimed in claim 15, wherein at least the radially outermost pie-shaped sections have diamond particles fixedly bonded therein of a third predetermined concentration of an amount less than said second predetermined concentration.

17. A surfacing wheel as claimed in claim 14, wherein said first predetermined concentration is of an amount so proportioned to said second predetermined concentration as to provide equal diamond impingement on the material being surfaced within an annular working zone conjointly including said arcuately truncated section and said adjacent pie-shaped sections.

18. A surfacing wheel for surfacing fiat sheets of glass and the like adapted to be rotatably driven about an axis of rotation, the surfacing wheel and the glass sheet to be surfaced being relatively and cooperatively movable in a predetermined directional sense in a plane transverse to the axis of rotation to facilitate surfacing of the glass sheet, comprising a plurality of satellite surfacing means having substantially coplanar contact elements formed of diamond particles of predetermined particle size and concentration fixedly bonded in supporting matrices to abrasively engage the surface of the glass sheet and being radially disposed about the axis of rotation in different respective sectors and spaced apart from each other and the axis of rotation, said contact element of each of said satellite surfacing means having a predetermined outer portion and a predetermined inner portion lying respectively in concentric outer and inner annular zones about the axis of rotation, the total engageable area of all of said contact element inner portions relative to the total area of said inner annular zone being of a greater proportion than the total engageable area of all of said contact element outer portions relative to the total area of said outer annular zone, the total engageable area of all of said contact element inner portions being greater than the total engageable area of all of said contact element outer portions, said satellite surfacing means outer portions being adapted to abrasively engage the glass sheet as it first passes under the surfacing wheel for performing a first surfacing operation, said satellite surfacing means inner portions being adapted to abrasively engage the glass sheet after it successively passes through the axis of rotation for performing a further surfacing operation, said satellite surfacing means contact element having a plurality of non-rotatable generally pieshaped sections disposed in a generally circular arrangement about a central point radially spaced from the surfacing wheel axis of rotation, said satellite surfacing means inner portions including at least the radially innermost one of said pie-shaped sections having diamond particles fixedly bonded therein of a first predetermined concentration and adjacent ones of said pie-shaped sections having portions radially equidistant from the axis of rotation with portions of said radially innermost sections with diamond particles of said first predetermined concentrations having diamond particles fixedly bonded therein of a second predetermined concentration materially less than said first predetermined concentration, said satellite surfacing means outer portions including at least the radially outermost pie-shaped sections having diamond particles fixedly bonded therein of a third predetermined concentration of an amount less than said second predetermined concentration.

19. A surfacing wheel as claimed in claim 18, wherein at least the radially innermost one of said pie-shaped sections is arcuately truncated on an arc spaced a predetermined radial distance from and about the axis of rotation, and all of the remaining ones of said pie-shaped sections being radially spaced from the axis of rotation by at least a distance equal to said predetermined radial distance.

References Cited UNITED STATES PATENTS 2,439,662 4/ 1948 Kidd 51-209 2,451,295 10/ 1948 Metzger 51-209 2,867,063 1/ 1959 Metzger 51-209 3,026,655 3/ 1962 Osenberg 51--209 3,121,982 2/1964 Miller 51-209 3,299,579 1/1967 Jacobson 5l--327 ROBERT C. RIORDON, Primary Examiner D. G. KELLY, Assistant Examiner

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