CA2112479A1 - Coated abrasives dressed by a multiple point cutting tool - Google Patents
Coated abrasives dressed by a multiple point cutting toolInfo
- Publication number
- CA2112479A1 CA2112479A1 CA 2112479 CA2112479A CA2112479A1 CA 2112479 A1 CA2112479 A1 CA 2112479A1 CA 2112479 CA2112479 CA 2112479 CA 2112479 A CA2112479 A CA 2112479A CA 2112479 A1 CA2112479 A1 CA 2112479A1
- Authority
- CA
- Canada
- Prior art keywords
- abrasive
- cutting
- coated
- belt
- dressing
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24B—MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING; DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS
- B24B53/00—Devices or means for dressing or conditioning abrasive surfaces
- B24B53/10—Devices or means for dressing or conditioning abrasive surfaces of travelling flexible backings coated with abrasives; Cleaning of abrasive belts
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B24—GRINDING; POLISHING
- B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
- B24D3/00—Physical features of abrasive bodies, or sheets, e.g. abrasive surfaces of special nature; Abrasive bodies or sheets characterised by their constituents
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Polishing Bodies And Polishing Tools (AREA)
Abstract
A dressing tool for use in methods for ''dressing'' coated abrasives (e.g. such as an endless belt) is disclosed. The tool has peripheral surfaces with abrasives that are generally as wide as the coated abrasives. The tool affords simultaneous dressing of multiple abrasive belts. Several methods for dressing a coated abrasive are also disclosed.
Description
2112l179 Coated Abrasives Dressed By A
Multiple Point Cutting Tool Technical Field 5The present invention relates generally to continuous coated abrasive articles of the typ~ having flexible backings with front and rear surfaces and abrasive particles including abrasive graîns attached ~
along their front surfaces. ~`
Backaround of the Invention The art is replete with abrasive articles used to create new surfaces on objects. Examples of such abrasîve articles are the endless abrasive belts 15 used în conjunction with the camshaft grinder disclosed in U.S. Patent No. 4,833,834. Such endless abrasive belts may be constructed using the abrasîve agglomerates described în Bloecher et al. U.S. Patent nu~ber 4,799,939 which may contain abrasîve graîns made -~
20 for~example according to the teachings in Schwabel U.S.
Patent Number 4,744,802. U.S. Patent 4,215,516 to Huschle et al. discloses a splicing system for butt splicing flexible abrasive belts to form a~ endless abrasive belt.
Abrasive agglomerates may include a plurality of ~brasive grains bonded together by a phenolic resin (e.g. a phenolic based make and size coat) or any other suitable binder to form a shaped mass, and the abrasive ~`
grains may be constructed from cerami aluminum oxide, -`
30 commercially available from the Minnesota Mining and Manufacturing Company (3M) of St. Paul, ~innesota under the tradejdesignation grade 120 "Cubitron" ceramic aluminum oxide abrasive grains, and may have a particle fiize of approximately 116 micrometers. As used in this 35 application, the phrase "abrasive agglomerate" is defined as a plurality of abrasive grains bonded together by a binder.
Figures 1 and 2 illustrate a coated abrasive belt 10 (e.g., the abrasive belt sold by Minnesota W093/0~837 ~g PCT/~S92/~5827 Mining and Manufacturing, St. Paul Minnesota, under the trade designation 3M "Multicut" T.M. Resin Bond cloth coated abrasive belts) after it is constructed but before it is used to abrade a workpiece. Such an 5 abrasive belt may be used, for example, in conjunction with the camshaft grinder disclosed in U.S. Patent No.
4,833,834 to grind pieces of metal stock having generally cylindrical portions into camshafts.
The coated abrasive belt 10 includes a 10 flexible backing 11 (e.g. cloth or polymeric film, ~
vulcanized fiber, paper, combinations thereof and ~`
treated versions thereof) with front and rear or "back"
surfaces, and a mound or mountain-shaped abrasive `
coating 12 which includes abrasive agglomerates 15 attached along the front surface of the backing ll.
The mountain-shaped surface of the abrasive belt ~-includes numerous peaks and valleys. The "height" of a peak is defined in this specification as the shortest distance between the back surface of the backing and 20 the top of the peak along the surface of the abrasive belt.
These and other existing abrasive belts encounter problems during "start up" or during their initial use. Initially, before the belt is used to 25 grind a workpiece/ the heights of the mountains along the mountain-shaped surface of the abrasive belt vary widely, as much as forty (40~ percent. The uneven thickness of the belt may be due to a variety of factors such as, but not limited to coating variations, 30 backing variations, or splices. The tallest peaks tend to cause undesirable results such as "wild scratches"
OF a coarse surface finish on the workpieces (e.g.
camshafts) which are ground during thP initial uses of the abrasive belt. It is believed that pressure is 35 initially concentrated at the tallest peaks until they break or shear from the remaining abrasive agglomerate attached to the abrasive belt. The breakage or shearing of the tallest peaks of the abrasive agglomerate ultimately leads to a more uniform belt -~
W093/02837 2 1 1 2 ~ 7 g PCT/US92/05827 thickness or caliper, but only after the end user risks leaving deep or "wild" scratches or risks creating an undesirably coarse finish on the workpiece.
The endless abrasive belts used with the 5 camshaft grinder disclosed in U.S. Patent 4,~33,834 should produce a consistent finish on the surface of camshafts. A coated abrasive belt such as the belt shown in Figures 1 and 2 may not leave the desirable -finish on the workpiece until the mountain shaped 10 abrasive is sufficiently worn. Another problem associated with the initial uses of the prior art endless abrasive belts on a camshaft grinder such as the camshaft grinder shown in U.S. Patent 4,833,834 is that the caliper or "thicknessl' of the belt initially 15 changes rapidly as the mountain-shaped portions are broken and worn away. The camshaft grinder is required ~-to continually adjust for this rapid change of belt ~`
caliper until the wear characteristics of the belt stabilizes~
Additionaily, existing abrasive belts encounter problem$ even after their "start up" or initial use. For example, when an abrasive belt is used to abrade a metal workpiece (e.g. a camshaft) the metal pieces which are abraded from the workpiece tend 25 to become welded over the surface of the abrasive.
This prematurely ends the useful life of a belt.
Some existing endless coated abrasive belts encounter pro~lems due to th ir lack of uniform thickness. Rnown butt splices are used to con5truct 30 some endless abrasive belts. In a butt splice, two `
edges of the backing of an abrasive sheet are abutted, and thereafter joined together with a reinforcing strip which i# bonded to the underside of the abrasive belt.
Coated abrasive belts which incorporate butt 35 splices may have a thickness which is greater at the splice than elsewhere along the belt. The height of the peaks of the agglomerate at the splice area will ~`
generally tend to be greater than the heights of the peaks along the remainder of the endless belt due to .~
.
Minnesota Mining 8~ :
Manufacturing Company .~; . M- 7061 . ~ c~ ~ rt~ PCr/US32/05827 ~ r~
':
the presence of the reinEorcing strip. Thls additional thickness or "height" in the splice area tends to leave "splice marks" or undes~rab~y deep "wild" scratches 1 the abraded workpiece.
Another known method of constructing an endless belt is ~nown as a "lap splice" whereln two ends of an abrasive belt sheet are overlapped to ~orm an endless abrasive belt. The thicknes-~ of the belt ~t the ~oint may be greater than the thickne~s o~ the belt 10 elsewhere due to the overlapped ends. Again, the dlfference in thickness or caliper of the bel~ at the lap splice tends to result in undesirable consequences such as marks or deeper "wild" scratches in the abraded ~
workpiece. -lS A known treatment of an abraslve product i8 dlsclosed in U.S. Patent No. 1,944,898 to McKee. McKee discloses prov~ding a pair of rolls constructed from a materl~l that i8 tougher than the abrasive material o~
the coated abrasive product (Figure 3). The mineral 20 particles of the abrasive article are "bro~en" down by -~
the touqher rolls. ~ -Known methods for dressing a grinding wheel are described by Kenneth B. Lewis and William F.
Schleicher in Chapter 14, pages ~49 to 164 o~ "The 25 Grinding Wheel" ~ Textbook o Modern Grinding Practice, - The Grlnding Wheel Xnstitute, Cleveland, Ohio (1976).
5rinding wheels are generally dressed to sharpen the wheel by exposing abrasive grains and are sometimes dressed to `'true" the wheel.
~, SU~ST~ T~: StlEET
21~2479 - `
Minnesota Mining &
Manufacturing Company Other prior arts of interest are the following three documents that were considered during the natent application stage of the present invention.
:
Soviet Patent Abstracts Section PQ, Week 9027 15.08.1990, Derwent Publications Ltd., London, GB; Class P, AN
90-208040/27 & SU-A-1 511 098. This prior art is concerned with a method of dressing abrasive cloth. The method comprises passing the cloth through a calibrating slit. The calibrating slit is formed by a suPport and a clamping element in the form of an abrasive drum. The hardness of the abrasive drum grains has to be equal to, or more than, the hardness of the abrasive cloth grains. The grains size of the abrasive drum has to be less or equal to the size of the abrasive cloth grains. As the grains of the cloth pass through the slit they engage with the grains of the drum and the apexes of the cloth grains are broken off.
Patent Abstracts of Japan, vol. 13, no. 163 (M-816) ~35111, 19.04.1989~ & JP-A-64-002 865.
This prior art discloses a method for dressing a polishing belt wherein an endless abrasive polishing belt driven b~ a roll is dressed b~ rubbing the belt with an abrasive cloth whereby the ends of the abrasive grains on the polishing belt are broken and fine grains of a desired mesh are said to be produced on the polishing belt.
SUE~STITUTE SH~ET
Minnesota Mining &
Manufacturing Company M 7061 ~ 4B - PCT~US92/05827 Soviet Patent Abstracts Section PQ, Week 9029, 29.08.1990, Derwent Publications Ltd; London, GB; Class P, AN 90-223 266/ 29 & SU-A-1 516 325. This prior art discloses a method of dressing a grinding belt by feeding the belt via a contact roller positioned above a dressing disc~ The contact line defined between the belt and the disc is offset from the center of the disc. To provide a uniform wearing out of the dressing disc a relative reciDrocal to-and-fro motion across the disc is created between said contact roller and said disc. The effect on the belt is described with reference to a Fig. 4 of this prior art document which sho~s that an initial profile with high peaks is reduced to a profile in which the peaks no longer exist and the remaining stumps that result from the removal of said peaks have a rough top face.
Disclosure of the Invention .
The present invention is as defined in the accompanying claims.
The invention provides a coated abrasive comprising a flexible backing with front and rear or "back" surfaces, a generally uniform width, and mounds of abrasive particles including abrasive grains attached along the front surface.
Initially, the mounds of abrasive particles project different distances in a predetermined range from the front surface of the bac~ing. A multiple point cutting means Fr W093/0~37 2 1 1 2 4 ~ ~3 PCT/US92/0~27 _ 5 ~
having a width at least substantially equal to the ;~
width of the backing and having a cutting surface constructed from a material harder than the abrasive grains i8 used to cut the mounds of the abrasive S particles to form generally coplanar surfaces generally parallel to the back surface. ~-In a preferred embodiment of the coated -abrasive, the mounds have heights measured from the -~
back surface of the Slexible backing, and the coplanar `.
10 surfaces have heights measured from the back surface of the flexible backing such that the heights of the mounds before cutting and the height of the coplanar surfaces~after cutting are described by the equation: `
15; P1 ~ X (P2); ;~
wherein~
X is between 1.1 and 2; and ~ ~`
Pl~-~the~height of~the tallest mound of the 20~ a~ra&ive~ particles~before cutting, and -~
P2- = the height of the tallest co-planar `surf~ce of the abrasive~particles after cutting by the cùtting means. In one embodiment, X i8 equal to 1.35. "~
The present invention may be characterized as 25~ a~method of quickly and conveniently "dressing" a coated~abrasive article that may be used in conjunction with automatic dressing mechanisms, which provides a more consistent uniform finish, which significantly reduces the tendency of the resultant coated abrasive `
30 article to create wild scratches or an otherwise deficient finish on a workpiece during the initial use of the ~brasive` article, and which provides a coated abrasive with more predictable wear characteristics and `
a more uniform caliper or thickness.
The coated abrasive of the present invention may be prepared by the process comprising the steps of: ~
; (1) provlding~a~fleYible bàcking with front and rear ;`
surfaces~and~having~a generàlly uniform width, and attàchlng~discrete mounds of~abrasive particles ~, :
WO g3/02837 ~ PCr/USg2/05827 including abrasive grains along the front surface, the mounds of abrasive particles projecting different distances in a predetermined range measured fro~ the rear or back surface of the backing, (2) providing a S multiple point cutting means having a width at least substantially equal to the width of the backing and having cutting surfaces constructed from a material h_rder than the abrasive grains, and then (3) cutting the mounds of the abrasive particles projecting more 10 than a predetermined distance within the range with the cutting means to form generally coplanar surfaces generally parallel to the back surface. The cutting means may have surfaces constructed from diamonds, boron~nitride or any other suitable cutting material so 15 long as the material is harder than the abrasive grains.
AdditionaIly, the present invention may be descr~ibed as~a m~thod of grinding workpieces using ~ endless coated~abrasive belts each comprising a ;~ 20~ flexible~backing with front and rear surfaces and mounds of abrasive particles including abrasive grains attached along the front surface. The endless coated abrasive belts may be mounted on a means for driving the endless abrasive belt, such as the camshaft grinder 25 described in U~S. Patent No. 4,833,~34. A multiple ; point cutting means having cutting surfaces harder than the abrasive grains is provided.
Next, the abrasive belts are driven past a grinding station and the belts are used to grind 30 several workpieces until the abrasive belt becomes dull, and then the endless abrasive belt is dressed while remaining mounted on the means for driving the endless abrasive belt by cutting the abrasive particles with the cutting means to remove debris and to 35 resharpen the belt. Additionally, each of the coated abrasive belts may be simultaneously dressed while they -~ are mounted on the camshaft grinder described in U.S.
Patent No. 4,833,834 and before they are used to grind a~workpiece.
W093/02837 2 1 1 2 4 7 9 PCT/US92/OS827 :~
7 ~
Brief Description of the Drawing i~
The present invention will be further :
described with reference to the accompanying drawing ~-wherein like reference numerals refer to like parts in .
5 the several views, and wherein:
Figure 1 is a cross~sectional phatographic view of a prior art coated abrasive before it is used :
to abrade a workpiece; :--Figure 2 is a photograph at a magnification 10 of twenty-five (25) of another portion of the coated i;
abrasive of Figure l; `.
~igure 3 is a cross-sectional photographic ~-view of coated abrasive after it has been dressed by the~method according to the present invention;
Figure 4 is a photograph at a magnification of twenty-five (25) of another portion of the abrasive ~`~
of Figure 3; -~
Figure S is a cross-sectional photographic view o~f a:coated abrasive belt after it has been used ~20 to grind 19 camshafts on a camshaft grinder; ~:~
Figure 6 is a photograph at a magnification ~`
of forty (40) of another portion of the coated a~rasive : belt shown in Figure 5;
Figure 7 is a schematic illustration of a 25 f irct embodiment of the method of making or "dressing" -a coated abrasiv~ according to the present invention;
Figure 8 is a perspective view of one embodiment of cutting means according to the present invention;
Figure 9 is a top view of a means for simultaneously driving a plurality of belts past a dressing/grinding station and the cutting means of Figure 8, which ilIustrates a technique for simultaneouæly dressing a plurality of abrasive belts;
Figure 10 is a schematic illustration of a second embodiment of the method of making or "dressing"
a coated abrasive according to the present invention;
, ~
, ~ :,``.' ,:
.
W 0 93/02837 ~ ~ P~r/US92/05827 Figure 11 is a schematic illustration of a third embodiment of the method of making or "dressing"
a coated abrasive according to the present invention;
Figure 12 is a cross-sectional photographic 5 view of a coated abrasive such as the coated abrasive of Figure 5 after it has been dressed subsequent to the grinding of (19) camshafts; and Figure 13 is a photograph at a magnification of forty (40) of another portion of the coated abrasive 10 belt of Figure 12.
Detailed Description Referrinq now to Figures 3 and 4 of the drawing, there is shown a coated abrasive according to 15 the present invention generally designated by the `~
reference number 20. The coated abrasive 20 comprises a flexible backing 21 with front and rear surfaces, and mounds of abrasive agglomerates 22 including abrasive grain# 23 (e.g. ceramic aluminum oxide, commercially ~; 20 available from the Minnesota Mining and Manufacturing ~-Company (3M) of St. Paul, Minnesota under the trade designation grade 120 "Cubitron" ceramic aluminum oxide abrasive grains with a particle size of approximately 116 micrometers) attached along the front surface (e.g.
Multiple Point Cutting Tool Technical Field 5The present invention relates generally to continuous coated abrasive articles of the typ~ having flexible backings with front and rear surfaces and abrasive particles including abrasive graîns attached ~
along their front surfaces. ~`
Backaround of the Invention The art is replete with abrasive articles used to create new surfaces on objects. Examples of such abrasîve articles are the endless abrasive belts 15 used în conjunction with the camshaft grinder disclosed in U.S. Patent No. 4,833,834. Such endless abrasive belts may be constructed using the abrasîve agglomerates described în Bloecher et al. U.S. Patent nu~ber 4,799,939 which may contain abrasîve graîns made -~
20 for~example according to the teachings in Schwabel U.S.
Patent Number 4,744,802. U.S. Patent 4,215,516 to Huschle et al. discloses a splicing system for butt splicing flexible abrasive belts to form a~ endless abrasive belt.
Abrasive agglomerates may include a plurality of ~brasive grains bonded together by a phenolic resin (e.g. a phenolic based make and size coat) or any other suitable binder to form a shaped mass, and the abrasive ~`
grains may be constructed from cerami aluminum oxide, -`
30 commercially available from the Minnesota Mining and Manufacturing Company (3M) of St. Paul, ~innesota under the tradejdesignation grade 120 "Cubitron" ceramic aluminum oxide abrasive grains, and may have a particle fiize of approximately 116 micrometers. As used in this 35 application, the phrase "abrasive agglomerate" is defined as a plurality of abrasive grains bonded together by a binder.
Figures 1 and 2 illustrate a coated abrasive belt 10 (e.g., the abrasive belt sold by Minnesota W093/0~837 ~g PCT/~S92/~5827 Mining and Manufacturing, St. Paul Minnesota, under the trade designation 3M "Multicut" T.M. Resin Bond cloth coated abrasive belts) after it is constructed but before it is used to abrade a workpiece. Such an 5 abrasive belt may be used, for example, in conjunction with the camshaft grinder disclosed in U.S. Patent No.
4,833,834 to grind pieces of metal stock having generally cylindrical portions into camshafts.
The coated abrasive belt 10 includes a 10 flexible backing 11 (e.g. cloth or polymeric film, ~
vulcanized fiber, paper, combinations thereof and ~`
treated versions thereof) with front and rear or "back"
surfaces, and a mound or mountain-shaped abrasive `
coating 12 which includes abrasive agglomerates 15 attached along the front surface of the backing ll.
The mountain-shaped surface of the abrasive belt ~-includes numerous peaks and valleys. The "height" of a peak is defined in this specification as the shortest distance between the back surface of the backing and 20 the top of the peak along the surface of the abrasive belt.
These and other existing abrasive belts encounter problems during "start up" or during their initial use. Initially, before the belt is used to 25 grind a workpiece/ the heights of the mountains along the mountain-shaped surface of the abrasive belt vary widely, as much as forty (40~ percent. The uneven thickness of the belt may be due to a variety of factors such as, but not limited to coating variations, 30 backing variations, or splices. The tallest peaks tend to cause undesirable results such as "wild scratches"
OF a coarse surface finish on the workpieces (e.g.
camshafts) which are ground during thP initial uses of the abrasive belt. It is believed that pressure is 35 initially concentrated at the tallest peaks until they break or shear from the remaining abrasive agglomerate attached to the abrasive belt. The breakage or shearing of the tallest peaks of the abrasive agglomerate ultimately leads to a more uniform belt -~
W093/02837 2 1 1 2 ~ 7 g PCT/US92/05827 thickness or caliper, but only after the end user risks leaving deep or "wild" scratches or risks creating an undesirably coarse finish on the workpiece.
The endless abrasive belts used with the 5 camshaft grinder disclosed in U.S. Patent 4,~33,834 should produce a consistent finish on the surface of camshafts. A coated abrasive belt such as the belt shown in Figures 1 and 2 may not leave the desirable -finish on the workpiece until the mountain shaped 10 abrasive is sufficiently worn. Another problem associated with the initial uses of the prior art endless abrasive belts on a camshaft grinder such as the camshaft grinder shown in U.S. Patent 4,833,834 is that the caliper or "thicknessl' of the belt initially 15 changes rapidly as the mountain-shaped portions are broken and worn away. The camshaft grinder is required ~-to continually adjust for this rapid change of belt ~`
caliper until the wear characteristics of the belt stabilizes~
Additionaily, existing abrasive belts encounter problem$ even after their "start up" or initial use. For example, when an abrasive belt is used to abrade a metal workpiece (e.g. a camshaft) the metal pieces which are abraded from the workpiece tend 25 to become welded over the surface of the abrasive.
This prematurely ends the useful life of a belt.
Some existing endless coated abrasive belts encounter pro~lems due to th ir lack of uniform thickness. Rnown butt splices are used to con5truct 30 some endless abrasive belts. In a butt splice, two `
edges of the backing of an abrasive sheet are abutted, and thereafter joined together with a reinforcing strip which i# bonded to the underside of the abrasive belt.
Coated abrasive belts which incorporate butt 35 splices may have a thickness which is greater at the splice than elsewhere along the belt. The height of the peaks of the agglomerate at the splice area will ~`
generally tend to be greater than the heights of the peaks along the remainder of the endless belt due to .~
.
Minnesota Mining 8~ :
Manufacturing Company .~; . M- 7061 . ~ c~ ~ rt~ PCr/US32/05827 ~ r~
':
the presence of the reinEorcing strip. Thls additional thickness or "height" in the splice area tends to leave "splice marks" or undes~rab~y deep "wild" scratches 1 the abraded workpiece.
Another known method of constructing an endless belt is ~nown as a "lap splice" whereln two ends of an abrasive belt sheet are overlapped to ~orm an endless abrasive belt. The thicknes-~ of the belt ~t the ~oint may be greater than the thickne~s o~ the belt 10 elsewhere due to the overlapped ends. Again, the dlfference in thickness or caliper of the bel~ at the lap splice tends to result in undesirable consequences such as marks or deeper "wild" scratches in the abraded ~
workpiece. -lS A known treatment of an abraslve product i8 dlsclosed in U.S. Patent No. 1,944,898 to McKee. McKee discloses prov~ding a pair of rolls constructed from a materl~l that i8 tougher than the abrasive material o~
the coated abrasive product (Figure 3). The mineral 20 particles of the abrasive article are "bro~en" down by -~
the touqher rolls. ~ -Known methods for dressing a grinding wheel are described by Kenneth B. Lewis and William F.
Schleicher in Chapter 14, pages ~49 to 164 o~ "The 25 Grinding Wheel" ~ Textbook o Modern Grinding Practice, - The Grlnding Wheel Xnstitute, Cleveland, Ohio (1976).
5rinding wheels are generally dressed to sharpen the wheel by exposing abrasive grains and are sometimes dressed to `'true" the wheel.
~, SU~ST~ T~: StlEET
21~2479 - `
Minnesota Mining &
Manufacturing Company Other prior arts of interest are the following three documents that were considered during the natent application stage of the present invention.
:
Soviet Patent Abstracts Section PQ, Week 9027 15.08.1990, Derwent Publications Ltd., London, GB; Class P, AN
90-208040/27 & SU-A-1 511 098. This prior art is concerned with a method of dressing abrasive cloth. The method comprises passing the cloth through a calibrating slit. The calibrating slit is formed by a suPport and a clamping element in the form of an abrasive drum. The hardness of the abrasive drum grains has to be equal to, or more than, the hardness of the abrasive cloth grains. The grains size of the abrasive drum has to be less or equal to the size of the abrasive cloth grains. As the grains of the cloth pass through the slit they engage with the grains of the drum and the apexes of the cloth grains are broken off.
Patent Abstracts of Japan, vol. 13, no. 163 (M-816) ~35111, 19.04.1989~ & JP-A-64-002 865.
This prior art discloses a method for dressing a polishing belt wherein an endless abrasive polishing belt driven b~ a roll is dressed b~ rubbing the belt with an abrasive cloth whereby the ends of the abrasive grains on the polishing belt are broken and fine grains of a desired mesh are said to be produced on the polishing belt.
SUE~STITUTE SH~ET
Minnesota Mining &
Manufacturing Company M 7061 ~ 4B - PCT~US92/05827 Soviet Patent Abstracts Section PQ, Week 9029, 29.08.1990, Derwent Publications Ltd; London, GB; Class P, AN 90-223 266/ 29 & SU-A-1 516 325. This prior art discloses a method of dressing a grinding belt by feeding the belt via a contact roller positioned above a dressing disc~ The contact line defined between the belt and the disc is offset from the center of the disc. To provide a uniform wearing out of the dressing disc a relative reciDrocal to-and-fro motion across the disc is created between said contact roller and said disc. The effect on the belt is described with reference to a Fig. 4 of this prior art document which sho~s that an initial profile with high peaks is reduced to a profile in which the peaks no longer exist and the remaining stumps that result from the removal of said peaks have a rough top face.
Disclosure of the Invention .
The present invention is as defined in the accompanying claims.
The invention provides a coated abrasive comprising a flexible backing with front and rear or "back" surfaces, a generally uniform width, and mounds of abrasive particles including abrasive grains attached along the front surface.
Initially, the mounds of abrasive particles project different distances in a predetermined range from the front surface of the bac~ing. A multiple point cutting means Fr W093/0~37 2 1 1 2 4 ~ ~3 PCT/US92/0~27 _ 5 ~
having a width at least substantially equal to the ;~
width of the backing and having a cutting surface constructed from a material harder than the abrasive grains i8 used to cut the mounds of the abrasive S particles to form generally coplanar surfaces generally parallel to the back surface. ~-In a preferred embodiment of the coated -abrasive, the mounds have heights measured from the -~
back surface of the Slexible backing, and the coplanar `.
10 surfaces have heights measured from the back surface of the flexible backing such that the heights of the mounds before cutting and the height of the coplanar surfaces~after cutting are described by the equation: `
15; P1 ~ X (P2); ;~
wherein~
X is between 1.1 and 2; and ~ ~`
Pl~-~the~height of~the tallest mound of the 20~ a~ra&ive~ particles~before cutting, and -~
P2- = the height of the tallest co-planar `surf~ce of the abrasive~particles after cutting by the cùtting means. In one embodiment, X i8 equal to 1.35. "~
The present invention may be characterized as 25~ a~method of quickly and conveniently "dressing" a coated~abrasive article that may be used in conjunction with automatic dressing mechanisms, which provides a more consistent uniform finish, which significantly reduces the tendency of the resultant coated abrasive `
30 article to create wild scratches or an otherwise deficient finish on a workpiece during the initial use of the ~brasive` article, and which provides a coated abrasive with more predictable wear characteristics and `
a more uniform caliper or thickness.
The coated abrasive of the present invention may be prepared by the process comprising the steps of: ~
; (1) provlding~a~fleYible bàcking with front and rear ;`
surfaces~and~having~a generàlly uniform width, and attàchlng~discrete mounds of~abrasive particles ~, :
WO g3/02837 ~ PCr/USg2/05827 including abrasive grains along the front surface, the mounds of abrasive particles projecting different distances in a predetermined range measured fro~ the rear or back surface of the backing, (2) providing a S multiple point cutting means having a width at least substantially equal to the width of the backing and having cutting surfaces constructed from a material h_rder than the abrasive grains, and then (3) cutting the mounds of the abrasive particles projecting more 10 than a predetermined distance within the range with the cutting means to form generally coplanar surfaces generally parallel to the back surface. The cutting means may have surfaces constructed from diamonds, boron~nitride or any other suitable cutting material so 15 long as the material is harder than the abrasive grains.
AdditionaIly, the present invention may be descr~ibed as~a m~thod of grinding workpieces using ~ endless coated~abrasive belts each comprising a ;~ 20~ flexible~backing with front and rear surfaces and mounds of abrasive particles including abrasive grains attached along the front surface. The endless coated abrasive belts may be mounted on a means for driving the endless abrasive belt, such as the camshaft grinder 25 described in U~S. Patent No. 4,833,~34. A multiple ; point cutting means having cutting surfaces harder than the abrasive grains is provided.
Next, the abrasive belts are driven past a grinding station and the belts are used to grind 30 several workpieces until the abrasive belt becomes dull, and then the endless abrasive belt is dressed while remaining mounted on the means for driving the endless abrasive belt by cutting the abrasive particles with the cutting means to remove debris and to 35 resharpen the belt. Additionally, each of the coated abrasive belts may be simultaneously dressed while they -~ are mounted on the camshaft grinder described in U.S.
Patent No. 4,833,834 and before they are used to grind a~workpiece.
W093/02837 2 1 1 2 4 7 9 PCT/US92/OS827 :~
7 ~
Brief Description of the Drawing i~
The present invention will be further :
described with reference to the accompanying drawing ~-wherein like reference numerals refer to like parts in .
5 the several views, and wherein:
Figure 1 is a cross~sectional phatographic view of a prior art coated abrasive before it is used :
to abrade a workpiece; :--Figure 2 is a photograph at a magnification 10 of twenty-five (25) of another portion of the coated i;
abrasive of Figure l; `.
~igure 3 is a cross-sectional photographic ~-view of coated abrasive after it has been dressed by the~method according to the present invention;
Figure 4 is a photograph at a magnification of twenty-five (25) of another portion of the abrasive ~`~
of Figure 3; -~
Figure S is a cross-sectional photographic view o~f a:coated abrasive belt after it has been used ~20 to grind 19 camshafts on a camshaft grinder; ~:~
Figure 6 is a photograph at a magnification ~`
of forty (40) of another portion of the coated a~rasive : belt shown in Figure 5;
Figure 7 is a schematic illustration of a 25 f irct embodiment of the method of making or "dressing" -a coated abrasiv~ according to the present invention;
Figure 8 is a perspective view of one embodiment of cutting means according to the present invention;
Figure 9 is a top view of a means for simultaneously driving a plurality of belts past a dressing/grinding station and the cutting means of Figure 8, which ilIustrates a technique for simultaneouæly dressing a plurality of abrasive belts;
Figure 10 is a schematic illustration of a second embodiment of the method of making or "dressing"
a coated abrasive according to the present invention;
, ~
, ~ :,``.' ,:
.
W 0 93/02837 ~ ~ P~r/US92/05827 Figure 11 is a schematic illustration of a third embodiment of the method of making or "dressing"
a coated abrasive according to the present invention;
Figure 12 is a cross-sectional photographic 5 view of a coated abrasive such as the coated abrasive of Figure 5 after it has been dressed subsequent to the grinding of (19) camshafts; and Figure 13 is a photograph at a magnification of forty (40) of another portion of the coated abrasive 10 belt of Figure 12.
Detailed Description Referrinq now to Figures 3 and 4 of the drawing, there is shown a coated abrasive according to 15 the present invention generally designated by the `~
reference number 20. The coated abrasive 20 comprises a flexible backing 21 with front and rear surfaces, and mounds of abrasive agglomerates 22 including abrasive grain# 23 (e.g. ceramic aluminum oxide, commercially ~; 20 available from the Minnesota Mining and Manufacturing ~-Company (3M) of St. Paul, Minnesota under the trade designation grade 120 "Cubitron" ceramic aluminum oxide abrasive grains with a particle size of approximately 116 micrometers) attached along the front surface (e.g.
2~ by phenolic based make and size coats). The mounds of abrasive agglomerates 22 initially project different distances in a predetermined range measured from the rear or back surface of the backing 21.
To begin constructing the coated abrasive 20, 30 the csated abrasive 10 shown in Figures 1 and 2 (e.g., the abrasive belt sold by Minnesota Mining and Manufacturing, St. Paul Minnesota, under the trade designation 3M "Multicut" T.M Resin Bond Cloth coated abrasive belts) may be selected. The coated abrasive 35 10 may be constructed using the abrasive agglomerates described in Bloecher et al~ ~.S. ~atent number 4,799,939 which may contain abrasive grains made for example according to the teachings in Schwabel U.S.
Patent Number 4,744,802.
21~2~ 79 g ..
Referring now to Figures 7 and 9 there is shown a schematic illustration of a first embodiment of the method of making or "dressing" a coated abrasive according to the present invention generally designated 5 by the reference number 40. The coated abrasives shown in Figure 7 are endless coated abrasive belts 41 which may be formed by utilizing a lap or butt splice. As mentioned above, endless belts having lap or butt splices may be thicker in some portions than others and 10 may tend to leave undesirable marks or wild scratches in the workpiece.
Figures 7 and 9 illustrate the prior art coated abrasives shown in Figures 1 and 2 after they are formed into the endless belts 41 and after they are 15 mounted on a means for driving the endless abrasive belt 41, such as the camshaft grinder described in U.S.
Patent No. 4,833,834 schematically illustrated as reference character 42.
Figure 8 illustrates a multiple point cutting `
20 means which is preferably constructed from a generally cylindrical piece of metal stock 50 which is similar to the pieces of metal stock which are ultimately ground into the asymmetrical cross-sections of the camshafts.
The use of a multiple point cutting means 25 substantially r~duces the time required to dress a coated abrasive when compared with the time required to dress a coated abrasive with a single point cutting tool. ~`
The cutting means is used to cut material `"
30 from the mountain-shaped surfaces (Figure 1) to form coplanar surfaces 25. The metal ætock 50 has cutting ~urfaces 53 harder than the abrasive grains 23 attached thereto on surfaces which are generally spaced the same as the spacings of the lobes on the camshafts.
35 Alternatively the cutting means may be continuously coated with cutting surfaces 53.
The cutting surfaces 53 may be attached to the periphery of the metal stock by any known method, such as but not limited to flame spraying or plating.
W093/02837 ~ PCI`/US92/05827 For example, the cutting means may comprise a piece of metal stock S0 having generally cylindrical periphery ^~
portions and a metal binder coated (e.g. electroplated or brazed) to selected portions of its generally S cylindrical periphery and with cutting surfaces 53 (e.g. diamonds or cubic boron nitride) applied to the metal binder. Another method of making a suitable ~
cutting means comprises the steps of providing a ;
generally cylindrical piece of metal stock and lO adhesively applying a strip of "DIAPAD" T.M. abrasive (commercially available from Minnesota Mining and Manufacturing, 3M, St. Paul, Minnesota) to the periphery of the metal stock with, for example pressure and a hot~melt adhesive.
~ Additionally, the cutting means may be constructed by laminating (e.g. adhesively) or plating a coated abrasîve containing the cutting surfaces 33 "~
birder~than the~abrasi~ve grain to the cylindrical piece ~-of~ et~l~stock~30. Also, U.S. Patent Gorsuch 4,256,467 20~discloses;another method of making a cutting means for use in~the method of the present invention by ~-~
electroplating a metal binder;and abrasive grains to a ~mesh~material.
, ~ .
- ~ In a preferred embodiment of the coated 25 abrasive 20, the mounds or mountain-shaped portions `
have heights measured from the back surface of the ~
flexible ~acking 21, and the coplanar surfaces 25 have heights also measured from the back surface of the flexible backing such that the heights of the mounds 30 before cuttinq (e.g. 12 of Figure 1) and the height of the coplanar surfaces after cutting are described by the equation:
,, , P1 ~ X tP2);
wherein:
Pl - the height of the tallest mound or mountain-shaped portion of the abrasive particles ~before cutting, and ;
.-:
l~linn~s~ta i~in ~-lg &
Manufacturing Company M 7061 2112 ~ 79 PC~/U~2/05~7 ~-P2 = the height of the tallest co-pl~nar surfacQ of the abrasive partlcles after cuttlng by the cutting m~ans.
When "Multicut" T.M. Resin Bond cloth coatQd 5 abrasive belt~ are used as th~ abra~lve, X ~
preferably within the range of between 1.1 and 2, since if X becomes less than 1.1 then the resultant abra~ive i5 underdressed and the attendant problem~ of scratching and rapid belt cal~par change are 10 encountered, and if X becomes greater than 2, then the belts tend to be overdressed which prematurely ~nds the useful llfe of thè belt.
For example, ~he~"Multicut" T.M. coated ~v abraslve may initially have a height of the tallest 15 mound of.the abrasive agglomerate 12 of approximately 1 (0.066 inche~. Such coated abrasives are useful for a variety of grinding operation~ and may be used, ror example, as an endless coated abrasive belt used to grind camshaft~ using a camshaft grinder such as the 20 camshaft grinder described ~n U.S. Patent No.
4,833,834. When using such coated abra~ives to grind `~
camshafts, ~t has been determined that dressing or cutting the height of the tallest co-planar surface 25 of the abras~ve particles 22 to abo~t~70.049 inches) 25 provides an abrasive belt with a more unlform caliper or thickness, and which significantly reduces the tendency of the resultant coated abrasive article to create wild scratching, damaging or an otherwise def~cient ~inlsh on a workpiece durlng the initial use 30 o~ the abrasive article particularly when using an endles~ belt which may have a raised abrasi~Q portion prox1mate its seam. In this example X i8 equal to 1.3S.
Dressing of an abrasive belt also provides a 35 coated abrasive with more predictable wear characteristics in that the useful life of a dressed belt 1s more readily predicted than a belt that i8 not drQssed. It i~ believed that the pressures at the abrad~ng interface of a dressed belt are more evenly SUBSTITUTE SHEET
W093/02837 2 ~ PCT/US92/05827 . - 12 -distributed over the abrasive surface once the mountain-shaped portions are cut into the plateau shapes.
The width of the periphery of a portion of 5 the metal stock 50 having the individual cutting surfaces 53 attached thereto is approximately the width of a single belt. The total area of the periphery of the metal stock 50 which has cutting surfaces 53 attached thereto is substantially egual to or greater 10 than the total of the widths of each of the endless abrasive belts 41. Such a cutting means affords the user the opportunity to dress multiple belts at the same time which substantially reduces the time required to dress the plurality of abrasive belts 41 when 15 compared with the time required to individually dress individual belts. Optionally a plurality of single-point diamond dressing tools may be used as the cutting means.
To cut the mountain shapes shown in Figure 1 20 into the shapes shown in Figure 3, the cylindrical piece of metal stock 50 may be rotated clockwise (alternatively the stock 50 may remain stationary) relative to the frame 45 of the grinding means 42 (Figure ~) by any suitable drive means as the belts 41 25 are driven by the grinding means 42, and then moved toward the abrasive belts 41 in a direction generaliy perpendicular to the axis of the cylindrical piece ~f stock 50 into contact with the abrasive until the desired amount of ~aterial is removed from the 30 abrasive.
When the abrasive belts 41 become dull or loverly contaminated with grinding debris (e.g. after they are used to grind several camshafts), the endless abrasive belts 41 may also be redressed while remaining 35 mounted on the means 42 for driving the endless abrasive belt by simply cutting the abrasive agglomerate with the cutting means 50, 53.
Figures 5 and 6 illustrate a coated abrasive after it is used to grind nineteen (19) camshafts on a ~`
-~
W093/02837 2 1 1 2 4 7 ~ PCT~US92/05827 camshaft grinder. At this point, the "Multicut"
abrasives tend to begin to become dull. Also, metal particles tend to become welded over the front surface of the abrasive.
Figures 12 and 13 illustrate the coated abrasive of Figures 5 and 6 after it has been redressed to resharpen and to clean the abrasive. Redressing or cutting the abrasive belts with the cutting means after ;
the belts are used to a~brade several workpieces is 10 believed to "clean" the abrasive belt by, for example, removing the metal particles which tend to weld themselves to the surface of the abrasive during grinding. Also, redressing the belts at this time provides a belt with a more uniform thickness and thus `
15 restricts the likelihood of wild scratches. Also, particularly when the abrasive comprises an abrasive belt with an agglomerate that includes abrasive grains, redressing the abrasive at this time is believed to expo e additional grains to thereby sharpen and extend 20 the life of the abrasive belts.
While the present invention has been described in conjunction with a camshaft grinder 42, it should be noted that the present invention may be practiced with any suitable grinding assembly which 2S utilizes a coated abrasive. For example, th~ formed wheel grinding assembly, conveyorized grinding assembly, centerless grinding assembly, surface grind ing assembly, flexible bed shaet grinding asse~bly, rotary table surface grinding assembly, and 30 swing grinding assembly described on pages 19-21 of Metalworking, Reference Manual, published by the Industrial Abrasives Division of Minnesota Mining and Manufacturing, ISBN #60-4400-0366-7 ~1294)JR may utilize the abrasive belts and the dressing methods of 35 the present invention. Also, the backstands, polishing jacks or vertical slack belt machines sold by KLX
Industries, Crystal, Minnesota, or G & P Industries, Indianapolis, Indiana may also utilize the abrasive belts and dressing methods of the presen~ invention.
W093/02837 PCT/US92/0~27 ~?, ~ 14 -Moreover, it is possible to dress an abrasive before it is mounted on the machine used to grind a workpiece. Figure 10 illustrates a second method of dressing coated abrasives according to the present 5 invention, generally designatèd by the reference character 18. A multiple point cutting means having a cutting surface 33 constructed from a material harder than the abrasive grains 23 is again used to cut the mounds of the abrasive particles 22 from the front 10 surface to form generally coplanar surfaces 25 (Figures 3 and 4) generally parallel to the front surface.
While Figures 7 and 9 illustrate coated abrasive belts dressed on a grinding machine, Figure 10 illustrates an example of a method of dressing coated 15 abrasives at a location remote from the location of their ultimate use. For example, the coated abrasives 20 may be dressed before they are shipped to the end ; user. ~;~
The coated abrasive 20 of the present 20 invention may be prepared by the process comprising the steps of: (1) providing a flexible backing 21 with front and rear surfaces, and attaching discrete mounds of abrasive particles which includes abrasive grains 23 ; along the front surface, the mounds of abrasive 25 particles projecting different distances in a predetermined range measured from the back surface of the backing tsee Figure 1), t2) providin~ multiple point cutting means (e.g. 30) having cutting surfaces 33 constructed from a material harder than the abrasive 30 grains 23, and then (3) cutting the mounds of the abrasive particles 12 projecting more than a predetermined distance within the range with the cutting means to form generally coplanar surfaces 25 generally parallel to the back surface.
Tbe cuttinq means has cutting surfaces 33 ; constructed from "super abrasives" such as diamonds, cubic boron nitride, metal carbides, metal nitrides or any other suitable cutting material as long as the material is harder than the abrasive grains 23. In : , , W093/02837 ~ 7 9 PCT/US92/OS827 : :
Figure 10, the entire periphery of the cutting means includes cutting surfaces 33, unlike the metal stock 50 which only has selected portions coated with the cutting surfaces.
The width of the metal stock 30 ~hould be at least substantially equal to the width of the coated abrasive 20 to afford efficient, effective dressing of :
the entire width of the abrasive 20. The method of making a coated abrasive 20 shown in Figure 10 is lO particularly suitable for dressing large sheets or rolls of an abrasive belt prior to shipment to the ultimate user.
In the embodiment shown in Figure 10, the :
dressing tool or multiple point cutting means comprises 15 a cylindrical piece of metal stock 30. The stock 30 may be rotated clockwise as the coated abrasive 20 is moved relative to the metal stoc~ 30 from left to right in the figure. Back-up means (not shown) are provided to support the coated abrasive 20. The cutting means 20 may be located proximate the coated abrasive then moved :
in a direction perpendicular to the axis of the oylindrical stock 30 toward the co3ted abraæive 20 into contact with the abrasive until the desired amount of ~aterial is cut from the coated abrasive 20. The 25 back-up means may comprise a hard flat surface or may comprise a hard cylindrical member adapted fsr clockwise rotation. Optionally, the cutting means may remain stationery or it ~ay be oscillated.
Referring now to Figure 11 there is shown a 30 schematic illustration of a third embodiment of the method of making or dr~ssing a coated abrasi~e according to the present invention generally designated by reference character 70.
The method illustrated in Figure ll is 3S particularly suitable for dressing a wound abrasive from any suitable, known workpiece feed mechanism. The workpiece feed mechanism may somprise an unwind wheel or drum 87 having a sheet of coated abrasives 71 wound z ~ PCTtUS92/05827 and journaled thereon, a back-up wheel 72, and a take-up wheel 73.
A multiple point cutting means 82 te.g. a generally cylindrical piece of metal stock) having 5 cutting surfaces 53 harder than the abrasive grains 23 i8 provided. Like the cutting means shown in Figure 10, the cutting means shown in Figure il may comprise a generally cylindrical piece of metal stock 82 having a periphery and a metal binder coated (e.g. electroplated 10 or brazed) to its periphery and with cutting surfaces 83 (e.g. diamonds or boron nitride) applied to the metal binder. Alternatively the cutting means may be constructed by laminating (e.g. adhesively) a coated abrasive containing the cutting sur~aces 83 harder than ~.
15 the abrasive grains to the cylindrical piece of metal tock 50.
The width of the metal stock 82 (not shown) should be at least substantially the same as the width of the coated abrasive roll 71. When a cutting means 20 having a width substantially equal to the total of the widths of the ~oated abrasive 71 is used, a large stock roll of coated abrasives ~ay be quickly, conveniently and efficiently d~essed in a relatively short period of time.
In the embodiment shown in Figure 11, the cylindrical piece of metal stock 82 may be rotated counterclockwise as the coated abrasive 71 is moved relative to the metal stock 82 by the take-up wheel 73 in the direct.ion 5hown by the arrows in the figure.
30 For example, the cutting means 82, 83 is moved in toward the back up wheel 72 into contact with the abrasive to efficiently cut the mounds of abrasive particles 22 until the desired amount of material is cut from the coated abrasive. Optionally, the cutting 35 means may be oscillated while in contact with the a~rasive.
The present invention has now been described with reference to several embodiments thereof. It will be apparent to those skilled in the art that many Minnea~ta ,~ining & .
Manufacturing Company 91 ~ ~ ~ 7n M 706~ ~ p~ 9~/058?7 - changes can be made in the embodiment described w~thout ;
departing from the scope of the present invention. For example, while the method o dressing a coated abrasiYe of the present invention has been described using the S abrasive belt sold by Minnesota Mining and Manufacturing, St. Paul, Minnesota, under the trade designation 3M "Multicut" T.M. Resin Bond Cloth Coated Abrasive Belts as exemplary, the method of the presQnt inventlon may be described with respect to ~ny suitable 10 abrasive such as, but not }imited to the abrasive -belts sold by Minnesota Mining and Manufacturing~ St.
Paul, Minnesota, under the trade designation 3M "Regal" ;~
T~.M. Resin Bond Cloth Belts, or the abrasive belt also sold by~Minnesota~Mining and Manufacturing Company, St.
- 15 Paul, Minnesota, under~the trade designation 3M ~31D
"Three-M-lte" T.M. Resin Bond Cloth Belts, or other ahraQ~i~ve-be~lts that are not agglomerates. Also, the me;hod~of the present invention is particularly suitable~for~use with automatic dressing mechanisms ;~
20~which~control the interference between the dressing tool/cuttlnq means and the coated abra~lve.
Additlonally, while the cutting means ha~ been descr~lbed as a cylindrical piece of metal 6toak, the cuttlng means may comprise any suitable shape, such as, 25 but not limited to flat, arcuate, trianqular, hexa~o~al or combinations thereof, as lonq as the cutting means ;~ 1ncludes cutting surfaces h~rder than the abrasive gralns 23. For example, the cutting mean~ may compri6e Diamond Impregnated Dresser Style No. 5S6, available ~0 from Carter Diamond Tool of Willoughby, Ohio that i~
intended for use with bonded wheels.
:
:
, `
STITUTE SHEET
To begin constructing the coated abrasive 20, 30 the csated abrasive 10 shown in Figures 1 and 2 (e.g., the abrasive belt sold by Minnesota Mining and Manufacturing, St. Paul Minnesota, under the trade designation 3M "Multicut" T.M Resin Bond Cloth coated abrasive belts) may be selected. The coated abrasive 35 10 may be constructed using the abrasive agglomerates described in Bloecher et al~ ~.S. ~atent number 4,799,939 which may contain abrasive grains made for example according to the teachings in Schwabel U.S.
Patent Number 4,744,802.
21~2~ 79 g ..
Referring now to Figures 7 and 9 there is shown a schematic illustration of a first embodiment of the method of making or "dressing" a coated abrasive according to the present invention generally designated 5 by the reference number 40. The coated abrasives shown in Figure 7 are endless coated abrasive belts 41 which may be formed by utilizing a lap or butt splice. As mentioned above, endless belts having lap or butt splices may be thicker in some portions than others and 10 may tend to leave undesirable marks or wild scratches in the workpiece.
Figures 7 and 9 illustrate the prior art coated abrasives shown in Figures 1 and 2 after they are formed into the endless belts 41 and after they are 15 mounted on a means for driving the endless abrasive belt 41, such as the camshaft grinder described in U.S.
Patent No. 4,833,834 schematically illustrated as reference character 42.
Figure 8 illustrates a multiple point cutting `
20 means which is preferably constructed from a generally cylindrical piece of metal stock 50 which is similar to the pieces of metal stock which are ultimately ground into the asymmetrical cross-sections of the camshafts.
The use of a multiple point cutting means 25 substantially r~duces the time required to dress a coated abrasive when compared with the time required to dress a coated abrasive with a single point cutting tool. ~`
The cutting means is used to cut material `"
30 from the mountain-shaped surfaces (Figure 1) to form coplanar surfaces 25. The metal ætock 50 has cutting ~urfaces 53 harder than the abrasive grains 23 attached thereto on surfaces which are generally spaced the same as the spacings of the lobes on the camshafts.
35 Alternatively the cutting means may be continuously coated with cutting surfaces 53.
The cutting surfaces 53 may be attached to the periphery of the metal stock by any known method, such as but not limited to flame spraying or plating.
W093/02837 ~ PCI`/US92/05827 For example, the cutting means may comprise a piece of metal stock S0 having generally cylindrical periphery ^~
portions and a metal binder coated (e.g. electroplated or brazed) to selected portions of its generally S cylindrical periphery and with cutting surfaces 53 (e.g. diamonds or cubic boron nitride) applied to the metal binder. Another method of making a suitable ~
cutting means comprises the steps of providing a ;
generally cylindrical piece of metal stock and lO adhesively applying a strip of "DIAPAD" T.M. abrasive (commercially available from Minnesota Mining and Manufacturing, 3M, St. Paul, Minnesota) to the periphery of the metal stock with, for example pressure and a hot~melt adhesive.
~ Additionally, the cutting means may be constructed by laminating (e.g. adhesively) or plating a coated abrasîve containing the cutting surfaces 33 "~
birder~than the~abrasi~ve grain to the cylindrical piece ~-of~ et~l~stock~30. Also, U.S. Patent Gorsuch 4,256,467 20~discloses;another method of making a cutting means for use in~the method of the present invention by ~-~
electroplating a metal binder;and abrasive grains to a ~mesh~material.
, ~ .
- ~ In a preferred embodiment of the coated 25 abrasive 20, the mounds or mountain-shaped portions `
have heights measured from the back surface of the ~
flexible ~acking 21, and the coplanar surfaces 25 have heights also measured from the back surface of the flexible backing such that the heights of the mounds 30 before cuttinq (e.g. 12 of Figure 1) and the height of the coplanar surfaces after cutting are described by the equation:
,, , P1 ~ X tP2);
wherein:
Pl - the height of the tallest mound or mountain-shaped portion of the abrasive particles ~before cutting, and ;
.-:
l~linn~s~ta i~in ~-lg &
Manufacturing Company M 7061 2112 ~ 79 PC~/U~2/05~7 ~-P2 = the height of the tallest co-pl~nar surfacQ of the abrasive partlcles after cuttlng by the cutting m~ans.
When "Multicut" T.M. Resin Bond cloth coatQd 5 abrasive belt~ are used as th~ abra~lve, X ~
preferably within the range of between 1.1 and 2, since if X becomes less than 1.1 then the resultant abra~ive i5 underdressed and the attendant problem~ of scratching and rapid belt cal~par change are 10 encountered, and if X becomes greater than 2, then the belts tend to be overdressed which prematurely ~nds the useful llfe of thè belt.
For example, ~he~"Multicut" T.M. coated ~v abraslve may initially have a height of the tallest 15 mound of.the abrasive agglomerate 12 of approximately 1 (0.066 inche~. Such coated abrasives are useful for a variety of grinding operation~ and may be used, ror example, as an endless coated abrasive belt used to grind camshaft~ using a camshaft grinder such as the 20 camshaft grinder described ~n U.S. Patent No.
4,833,834. When using such coated abra~ives to grind `~
camshafts, ~t has been determined that dressing or cutting the height of the tallest co-planar surface 25 of the abras~ve particles 22 to abo~t~70.049 inches) 25 provides an abrasive belt with a more unlform caliper or thickness, and which significantly reduces the tendency of the resultant coated abrasive article to create wild scratching, damaging or an otherwise def~cient ~inlsh on a workpiece durlng the initial use 30 o~ the abrasive article particularly when using an endles~ belt which may have a raised abrasi~Q portion prox1mate its seam. In this example X i8 equal to 1.3S.
Dressing of an abrasive belt also provides a 35 coated abrasive with more predictable wear characteristics in that the useful life of a dressed belt 1s more readily predicted than a belt that i8 not drQssed. It i~ believed that the pressures at the abrad~ng interface of a dressed belt are more evenly SUBSTITUTE SHEET
W093/02837 2 ~ PCT/US92/05827 . - 12 -distributed over the abrasive surface once the mountain-shaped portions are cut into the plateau shapes.
The width of the periphery of a portion of 5 the metal stock 50 having the individual cutting surfaces 53 attached thereto is approximately the width of a single belt. The total area of the periphery of the metal stock 50 which has cutting surfaces 53 attached thereto is substantially egual to or greater 10 than the total of the widths of each of the endless abrasive belts 41. Such a cutting means affords the user the opportunity to dress multiple belts at the same time which substantially reduces the time required to dress the plurality of abrasive belts 41 when 15 compared with the time required to individually dress individual belts. Optionally a plurality of single-point diamond dressing tools may be used as the cutting means.
To cut the mountain shapes shown in Figure 1 20 into the shapes shown in Figure 3, the cylindrical piece of metal stock 50 may be rotated clockwise (alternatively the stock 50 may remain stationary) relative to the frame 45 of the grinding means 42 (Figure ~) by any suitable drive means as the belts 41 25 are driven by the grinding means 42, and then moved toward the abrasive belts 41 in a direction generaliy perpendicular to the axis of the cylindrical piece ~f stock 50 into contact with the abrasive until the desired amount of ~aterial is removed from the 30 abrasive.
When the abrasive belts 41 become dull or loverly contaminated with grinding debris (e.g. after they are used to grind several camshafts), the endless abrasive belts 41 may also be redressed while remaining 35 mounted on the means 42 for driving the endless abrasive belt by simply cutting the abrasive agglomerate with the cutting means 50, 53.
Figures 5 and 6 illustrate a coated abrasive after it is used to grind nineteen (19) camshafts on a ~`
-~
W093/02837 2 1 1 2 4 7 ~ PCT~US92/05827 camshaft grinder. At this point, the "Multicut"
abrasives tend to begin to become dull. Also, metal particles tend to become welded over the front surface of the abrasive.
Figures 12 and 13 illustrate the coated abrasive of Figures 5 and 6 after it has been redressed to resharpen and to clean the abrasive. Redressing or cutting the abrasive belts with the cutting means after ;
the belts are used to a~brade several workpieces is 10 believed to "clean" the abrasive belt by, for example, removing the metal particles which tend to weld themselves to the surface of the abrasive during grinding. Also, redressing the belts at this time provides a belt with a more uniform thickness and thus `
15 restricts the likelihood of wild scratches. Also, particularly when the abrasive comprises an abrasive belt with an agglomerate that includes abrasive grains, redressing the abrasive at this time is believed to expo e additional grains to thereby sharpen and extend 20 the life of the abrasive belts.
While the present invention has been described in conjunction with a camshaft grinder 42, it should be noted that the present invention may be practiced with any suitable grinding assembly which 2S utilizes a coated abrasive. For example, th~ formed wheel grinding assembly, conveyorized grinding assembly, centerless grinding assembly, surface grind ing assembly, flexible bed shaet grinding asse~bly, rotary table surface grinding assembly, and 30 swing grinding assembly described on pages 19-21 of Metalworking, Reference Manual, published by the Industrial Abrasives Division of Minnesota Mining and Manufacturing, ISBN #60-4400-0366-7 ~1294)JR may utilize the abrasive belts and the dressing methods of 35 the present invention. Also, the backstands, polishing jacks or vertical slack belt machines sold by KLX
Industries, Crystal, Minnesota, or G & P Industries, Indianapolis, Indiana may also utilize the abrasive belts and dressing methods of the presen~ invention.
W093/02837 PCT/US92/0~27 ~?, ~ 14 -Moreover, it is possible to dress an abrasive before it is mounted on the machine used to grind a workpiece. Figure 10 illustrates a second method of dressing coated abrasives according to the present 5 invention, generally designatèd by the reference character 18. A multiple point cutting means having a cutting surface 33 constructed from a material harder than the abrasive grains 23 is again used to cut the mounds of the abrasive particles 22 from the front 10 surface to form generally coplanar surfaces 25 (Figures 3 and 4) generally parallel to the front surface.
While Figures 7 and 9 illustrate coated abrasive belts dressed on a grinding machine, Figure 10 illustrates an example of a method of dressing coated 15 abrasives at a location remote from the location of their ultimate use. For example, the coated abrasives 20 may be dressed before they are shipped to the end ; user. ~;~
The coated abrasive 20 of the present 20 invention may be prepared by the process comprising the steps of: (1) providing a flexible backing 21 with front and rear surfaces, and attaching discrete mounds of abrasive particles which includes abrasive grains 23 ; along the front surface, the mounds of abrasive 25 particles projecting different distances in a predetermined range measured from the back surface of the backing tsee Figure 1), t2) providin~ multiple point cutting means (e.g. 30) having cutting surfaces 33 constructed from a material harder than the abrasive 30 grains 23, and then (3) cutting the mounds of the abrasive particles 12 projecting more than a predetermined distance within the range with the cutting means to form generally coplanar surfaces 25 generally parallel to the back surface.
Tbe cuttinq means has cutting surfaces 33 ; constructed from "super abrasives" such as diamonds, cubic boron nitride, metal carbides, metal nitrides or any other suitable cutting material as long as the material is harder than the abrasive grains 23. In : , , W093/02837 ~ 7 9 PCT/US92/OS827 : :
Figure 10, the entire periphery of the cutting means includes cutting surfaces 33, unlike the metal stock 50 which only has selected portions coated with the cutting surfaces.
The width of the metal stock 30 ~hould be at least substantially equal to the width of the coated abrasive 20 to afford efficient, effective dressing of :
the entire width of the abrasive 20. The method of making a coated abrasive 20 shown in Figure 10 is lO particularly suitable for dressing large sheets or rolls of an abrasive belt prior to shipment to the ultimate user.
In the embodiment shown in Figure 10, the :
dressing tool or multiple point cutting means comprises 15 a cylindrical piece of metal stock 30. The stock 30 may be rotated clockwise as the coated abrasive 20 is moved relative to the metal stoc~ 30 from left to right in the figure. Back-up means (not shown) are provided to support the coated abrasive 20. The cutting means 20 may be located proximate the coated abrasive then moved :
in a direction perpendicular to the axis of the oylindrical stock 30 toward the co3ted abraæive 20 into contact with the abrasive until the desired amount of ~aterial is cut from the coated abrasive 20. The 25 back-up means may comprise a hard flat surface or may comprise a hard cylindrical member adapted fsr clockwise rotation. Optionally, the cutting means may remain stationery or it ~ay be oscillated.
Referring now to Figure 11 there is shown a 30 schematic illustration of a third embodiment of the method of making or dr~ssing a coated abrasi~e according to the present invention generally designated by reference character 70.
The method illustrated in Figure ll is 3S particularly suitable for dressing a wound abrasive from any suitable, known workpiece feed mechanism. The workpiece feed mechanism may somprise an unwind wheel or drum 87 having a sheet of coated abrasives 71 wound z ~ PCTtUS92/05827 and journaled thereon, a back-up wheel 72, and a take-up wheel 73.
A multiple point cutting means 82 te.g. a generally cylindrical piece of metal stock) having 5 cutting surfaces 53 harder than the abrasive grains 23 i8 provided. Like the cutting means shown in Figure 10, the cutting means shown in Figure il may comprise a generally cylindrical piece of metal stock 82 having a periphery and a metal binder coated (e.g. electroplated 10 or brazed) to its periphery and with cutting surfaces 83 (e.g. diamonds or boron nitride) applied to the metal binder. Alternatively the cutting means may be constructed by laminating (e.g. adhesively) a coated abrasive containing the cutting sur~aces 83 harder than ~.
15 the abrasive grains to the cylindrical piece of metal tock 50.
The width of the metal stock 82 (not shown) should be at least substantially the same as the width of the coated abrasive roll 71. When a cutting means 20 having a width substantially equal to the total of the widths of the ~oated abrasive 71 is used, a large stock roll of coated abrasives ~ay be quickly, conveniently and efficiently d~essed in a relatively short period of time.
In the embodiment shown in Figure 11, the cylindrical piece of metal stock 82 may be rotated counterclockwise as the coated abrasive 71 is moved relative to the metal stock 82 by the take-up wheel 73 in the direct.ion 5hown by the arrows in the figure.
30 For example, the cutting means 82, 83 is moved in toward the back up wheel 72 into contact with the abrasive to efficiently cut the mounds of abrasive particles 22 until the desired amount of material is cut from the coated abrasive. Optionally, the cutting 35 means may be oscillated while in contact with the a~rasive.
The present invention has now been described with reference to several embodiments thereof. It will be apparent to those skilled in the art that many Minnea~ta ,~ining & .
Manufacturing Company 91 ~ ~ ~ 7n M 706~ ~ p~ 9~/058?7 - changes can be made in the embodiment described w~thout ;
departing from the scope of the present invention. For example, while the method o dressing a coated abrasiYe of the present invention has been described using the S abrasive belt sold by Minnesota Mining and Manufacturing, St. Paul, Minnesota, under the trade designation 3M "Multicut" T.M. Resin Bond Cloth Coated Abrasive Belts as exemplary, the method of the presQnt inventlon may be described with respect to ~ny suitable 10 abrasive such as, but not }imited to the abrasive -belts sold by Minnesota Mining and Manufacturing~ St.
Paul, Minnesota, under the trade designation 3M "Regal" ;~
T~.M. Resin Bond Cloth Belts, or the abrasive belt also sold by~Minnesota~Mining and Manufacturing Company, St.
- 15 Paul, Minnesota, under~the trade designation 3M ~31D
"Three-M-lte" T.M. Resin Bond Cloth Belts, or other ahraQ~i~ve-be~lts that are not agglomerates. Also, the me;hod~of the present invention is particularly suitable~for~use with automatic dressing mechanisms ;~
20~which~control the interference between the dressing tool/cuttlnq means and the coated abra~lve.
Additlonally, while the cutting means ha~ been descr~lbed as a cylindrical piece of metal 6toak, the cuttlng means may comprise any suitable shape, such as, 25 but not limited to flat, arcuate, trianqular, hexa~o~al or combinations thereof, as lonq as the cutting means ;~ 1ncludes cutting surfaces h~rder than the abrasive gralns 23. For example, the cutting mean~ may compri6e Diamond Impregnated Dresser Style No. 5S6, available ~0 from Carter Diamond Tool of Willoughby, Ohio that i~
intended for use with bonded wheels.
:
:
, `
STITUTE SHEET
Claims (12)
1. A method of manufacturing a coated abrasive comprising the steps of:
providing a flexible backing with front and back surfaces and a generally uniform width, attaching mounds of abrasive particles including abrasive grains along the front surface, the mounds of abrasive particles projecting different distances in a predetermined range measured from the back surface of the backing, providing multiple point cutting means having a cutting surface constructed from a material harder than the abrasive grains and having a width at least substantially equal to the width of the flexible backing, and then cutting the mounds of the abrasive particles including the abrasive grains with the cutting means to form generally coplanar surfaces generally parallel to the back surface.
providing a flexible backing with front and back surfaces and a generally uniform width, attaching mounds of abrasive particles including abrasive grains along the front surface, the mounds of abrasive particles projecting different distances in a predetermined range measured from the back surface of the backing, providing multiple point cutting means having a cutting surface constructed from a material harder than the abrasive grains and having a width at least substantially equal to the width of the flexible backing, and then cutting the mounds of the abrasive particles including the abrasive grains with the cutting means to form generally coplanar surfaces generally parallel to the back surface.
2. A method of manufacturing a coated abrasive according to claim 1 wherein the mounds have heights measured from the back surface of the flexible backing, and the coplanar surfaces have heights measured from the back surface of the flexible backing such that the heights of the mounds before cutting and the height of the coplanar surfaces after cutting are described by the following equation:
P1 ? X (P2);
wherein:
X is between 1.1 and 2; and P1 = the height of the tallest mound of the abrasive particles before cutting, and P2 = the height of the tallest co-planar surface of the abrasive particles after cutting by the cutting means.
P1 ? X (P2);
wherein:
X is between 1.1 and 2; and P1 = the height of the tallest mound of the abrasive particles before cutting, and P2 = the height of the tallest co-planar surface of the abrasive particles after cutting by the cutting means.
3. A method of manufacturing a coated abrasive according to claim 2 wherein X is equal to 1.35.
4. A method of manufacturing a coated abrasive according to claim 1 wherein the step of providing multiple point cutting means having a cutting surface constructed from a material harder than the abrasive grains comprises the steps of:
providing a dressing tool having a generally cylindrical surface and a periphery, coating the periphery of the dressing tool with a metal binder, and attaching a diamond abrasive grain to the periphery of the dressing tool.
providing a dressing tool having a generally cylindrical surface and a periphery, coating the periphery of the dressing tool with a metal binder, and attaching a diamond abrasive grain to the periphery of the dressing tool.
5. A method of manufacturing a coated abrasive according to claim 1 wherein the step of providing multiple point cutting means having a cutting surface constructed from a material harder than the abrasive grains comprises the steps of:
providing a dressing tool having a generally cylindrical surface and having a periphery, coating the periphery of the dressing tool with a metal binder, and attaching a cubic boron nitride abrasive grain to the periphery of the dressing tool.
providing a dressing tool having a generally cylindrical surface and having a periphery, coating the periphery of the dressing tool with a metal binder, and attaching a cubic boron nitride abrasive grain to the periphery of the dressing tool.
6. A method of manufacturing a coated abrasive according to claim 1 wherein the step of cutting the mounds of the abrasive particles comprises the steps of:
rotating the cutting means; and moving the cutting means into contact with the coated abrasive until the desired amount of material is is removed from the coated abrasive.
rotating the cutting means; and moving the cutting means into contact with the coated abrasive until the desired amount of material is is removed from the coated abrasive.
7. A method of grinding workpieces using a endless coated abrasive belt comprising a flexible backing with front and back surfaces, a substantially uniform width and mounds of abrasive particles including abrasive grains, the abrasive particles having generally coplanar surfaces generally parallel to the back surface attached along the front surface, the method of grinding a workpiece comprising the steps of:
providing a means for driving the endless abrasive belt, providing multiple point cutting means having cutting surfaces harder than the abrasive grains and having a width at least substantially equal to the width of the backing, mounting the endless abrasive belt on the means for driving the endless abrasive belt, grinding the workpiece with the endless abrasive belt until the abrasive belt becomes dull, and then dressing the endless abrasive belt on the means for driving the endless abrasive belt by cutting the abrasive particles with the multiple point cutting means to resharpen the belt.
providing a means for driving the endless abrasive belt, providing multiple point cutting means having cutting surfaces harder than the abrasive grains and having a width at least substantially equal to the width of the backing, mounting the endless abrasive belt on the means for driving the endless abrasive belt, grinding the workpiece with the endless abrasive belt until the abrasive belt becomes dull, and then dressing the endless abrasive belt on the means for driving the endless abrasive belt by cutting the abrasive particles with the multiple point cutting means to resharpen the belt.
8. A method of dressing a coated abrasive comprising a flexible backing with front and back surfaces and mounds of abrasive particles including abrasive grains, the coated abrasive having a generally uniform width, the method of dressing a coated abrasive comprising the steps of:
providing a means for driving the coated abrasive during abrasion of a workpiece, providing multiple point cutting means having cutting surfaces harder than the abrasive grains and having a width at least substantially equal to the width of the backing, mounting the coated abrasive on the means for driving the coated abrasive, driving the coated abrasive past a dressing station, and then dressing the coated abrasive on the means for driving the coated abrasive by cutting the abrasive particles with the cutting means to provide uniform belt caliper.
providing a means for driving the coated abrasive during abrasion of a workpiece, providing multiple point cutting means having cutting surfaces harder than the abrasive grains and having a width at least substantially equal to the width of the backing, mounting the coated abrasive on the means for driving the coated abrasive, driving the coated abrasive past a dressing station, and then dressing the coated abrasive on the means for driving the coated abrasive by cutting the abrasive particles with the cutting means to provide uniform belt caliper.
9. A method of dressing a coated abrasive according to Claim 8 wherein the step of dressing the coated abrasive comprises the steps of:
rotating the cutting means; and moving the cutting means into contact with the coated abasive until the desires amount of material is removed from the coated abrasive.
rotating the cutting means; and moving the cutting means into contact with the coated abasive until the desires amount of material is removed from the coated abrasive.
10. A method of dressing coated abrasives comprising the steps of:
providing a plurality of endless coated abrasive belts each comprising a flexible backing with front and back surfaces, a width, and mounds of abasive particles including abrasive grains, providing means for driving the endless abrasive belts, mounting the endless coated abrasive belts on the means for driving the endless abrasive belts, providing a plurality of cutting means having a cutting surface harder than the abrasive grains, and then similtaneously dressing each of the endless abrasive belts by cutting the abrasive particles with the cutting means.
providing a plurality of endless coated abrasive belts each comprising a flexible backing with front and back surfaces, a width, and mounds of abasive particles including abrasive grains, providing means for driving the endless abrasive belts, mounting the endless coated abrasive belts on the means for driving the endless abrasive belts, providing a plurality of cutting means having a cutting surface harder than the abrasive grains, and then similtaneously dressing each of the endless abrasive belts by cutting the abrasive particles with the cutting means.
11. The method of dressing coated abrasives according to Claim 10 wherein:
the endless coated abrasive belts have generally coplanar surfaces generally parallel to the back surface attached along the front surface, said plurality of cutting means having cutting surfaces harder than the abrasive grains are multiple point cutting means having a width at least substantially equal to or greater than the total of the widths of each of the endless abrasive belts, and said simultaneous dressing of each of the endless abrasive belts is carried out on the means of driving the endless abrasive belt by cutting the abrasive particles with said multiple point cutting means.
the endless coated abrasive belts have generally coplanar surfaces generally parallel to the back surface attached along the front surface, said plurality of cutting means having cutting surfaces harder than the abrasive grains are multiple point cutting means having a width at least substantially equal to or greater than the total of the widths of each of the endless abrasive belts, and said simultaneous dressing of each of the endless abrasive belts is carried out on the means of driving the endless abrasive belt by cutting the abrasive particles with said multiple point cutting means.
12. In combination, a grinding apparatus having a plurality of spaced coated abrasive belts, each abrasive belt comprising a flexible backing with front and back surfaces, a width, and mounds of abrasive particles including abrasive grains, which abrasive belt is adapted to grind camshafts having spaced lobes, means for driving the coated abrasive belts, and a dressing tool adapted to simultaneously dress the plurality of abrasive belts comprising:
a periphery portion including:
a first portion having multiple point cutting surfaces attached along the periphery portion that are constructed from a material harder than the abrasive grains, said first portion having a width generally equal to the width of an abrasive belt on the grinding apparatus, a second portion being free of cutting surfaces and having a width generally equal to the spacing between abrasive belts on the grinding apparatus, and a third portion having multiple point cutting surfaces attached along the periphery portion that are constructed from a material harder than the abrasive grains, said third portion having a width generally equal to the width of an abrasive belt on the grinding apparatus.
a periphery portion including:
a first portion having multiple point cutting surfaces attached along the periphery portion that are constructed from a material harder than the abrasive grains, said first portion having a width generally equal to the width of an abrasive belt on the grinding apparatus, a second portion being free of cutting surfaces and having a width generally equal to the spacing between abrasive belts on the grinding apparatus, and a third portion having multiple point cutting surfaces attached along the periphery portion that are constructed from a material harder than the abrasive grains, said third portion having a width generally equal to the width of an abrasive belt on the grinding apparatus.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US73824991A | 1991-07-30 | 1991-07-30 | |
| US07/738,249 | 1991-07-30 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2112479A1 true CA2112479A1 (en) | 1993-02-18 |
Family
ID=24967214
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2112479 Abandoned CA2112479A1 (en) | 1991-07-30 | 1992-07-13 | Coated abrasives dressed by a multiple point cutting tool |
Country Status (6)
| Country | Link |
|---|---|
| EP (1) | EP0596999B1 (en) |
| JP (1) | JPH06509519A (en) |
| CA (1) | CA2112479A1 (en) |
| DE (1) | DE69211137T2 (en) |
| ES (1) | ES2087550T3 (en) |
| WO (1) | WO1993002837A1 (en) |
Families Citing this family (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| BR9206806A (en) * | 1991-12-20 | 1995-10-31 | Minnesota Mining & Mfg | Abrasive coated and abrasive coated |
| US6406577B1 (en) | 1991-12-20 | 2002-06-18 | 3M Innovative Properties Company | Method of making abrasive belt with an endless, seamless backing |
| US6406576B1 (en) | 1991-12-20 | 2002-06-18 | 3M Innovative Properties Company | Method of making coated abrasive belt with an endless, seamless backing |
| WO1995022438A1 (en) * | 1994-02-22 | 1995-08-24 | Minnesota Mining And Manufacturing Company | Method for making an endless coated abrasive article and the product thereof |
| CN1060110C (en) * | 1995-05-26 | 2001-01-03 | 清华大学 | Soft-elastic dressing method for diamond grinding wheel |
| US5578096A (en) * | 1995-08-10 | 1996-11-26 | Minnesota Mining And Manufacturing Company | Method for making a spliceless coated abrasive belt and the product thereof |
| JPH106218A (en) * | 1996-06-27 | 1998-01-13 | Minnesota Mining & Mfg Co <3M> | Abrasive product for dressing |
| KR20010005993A (en) | 1997-04-04 | 2001-01-15 | 오브시디안 인코포레이티드 | Polishing media magazine for improved polishing |
| US6517414B1 (en) | 2000-03-10 | 2003-02-11 | Appied Materials, Inc. | Method and apparatus for controlling a pad conditioning process of a chemical-mechanical polishing apparatus |
| US6561884B1 (en) | 2000-08-29 | 2003-05-13 | Applied Materials, Inc. | Web lift system for chemical mechanical planarization |
| CN109623659B (en) * | 2018-12-05 | 2019-12-20 | 郑州磨料磨具磨削研究所有限公司 | Friction driving dressing device and friction driving dressing method for superhard grinding wheel |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4833834A (en) * | 1987-10-30 | 1989-05-30 | General Motors Corporation | Camshaft belt grinder |
| US4954139A (en) * | 1989-03-31 | 1990-09-04 | The General Electric Company | Method for producing polycrystalline compact tool blanks with flat carbide support/diamond or CBN interfaces |
| JP2994404B2 (en) * | 1989-07-06 | 1999-12-27 | ハイ・コントロール・リミテッド | Method for producing abrasive sheet for applying binder in foam form |
-
1992
- 1992-07-13 ES ES92916764T patent/ES2087550T3/en not_active Expired - Lifetime
- 1992-07-13 CA CA 2112479 patent/CA2112479A1/en not_active Abandoned
- 1992-07-13 EP EP92916764A patent/EP0596999B1/en not_active Expired - Lifetime
- 1992-07-13 WO PCT/US1992/005827 patent/WO1993002837A1/en active IP Right Grant
- 1992-07-13 JP JP5503576A patent/JPH06509519A/en active Pending
- 1992-07-13 DE DE69211137T patent/DE69211137T2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| WO1993002837A1 (en) | 1993-02-18 |
| DE69211137T2 (en) | 1997-01-23 |
| DE69211137D1 (en) | 1996-07-04 |
| JPH06509519A (en) | 1994-10-27 |
| EP0596999B1 (en) | 1996-05-29 |
| ES2087550T3 (en) | 1996-07-16 |
| EP0596999A1 (en) | 1994-05-18 |
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