US3571980A - Abrasive structures having a compression-producing reinforcing ring - Google Patents

Abrasive structures having a compression-producing reinforcing ring Download PDF

Info

Publication number
US3571980A
US3571980A US829950A US3571980DA US3571980A US 3571980 A US3571980 A US 3571980A US 829950 A US829950 A US 829950A US 3571980D A US3571980D A US 3571980DA US 3571980 A US3571980 A US 3571980A
Authority
US
United States
Prior art keywords
ring
grinding wheel
tension
central aperture
aperture
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.)
Expired - Lifetime
Application number
US829950A
Other languages
English (en)
Inventor
Robert C Fisher
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Milacron Inc
Original Assignee
Milacron Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Milacron Inc filed Critical Milacron Inc
Application granted granted Critical
Publication of US3571980A publication Critical patent/US3571980A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
    • B24D5/16—Bushings; Mountings
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B24—GRINDING; POLISHING
    • B24D—TOOLS FOR GRINDING, BUFFING OR SHARPENING
    • B24D5/00—Bonded abrasive wheels, or wheels with inserted abrasive blocks, designed for acting only by their periphery; Bushings or mountings therefor
    • B24D5/02—Wheels in one piece
    • B24D5/04—Wheels in one piece with reinforcing means

Definitions

  • ABSTRACT As an article and a method for making a reinforced grinding wheel wherein either (a) an in-tension ring is inserted into the grinding wheel central aperture or (b) an untensioned ring is inserted into the grinding wheel central aperture. and tensioned or (c) an annular disc formed of abrasive grains and a binder is molded around the periphery of an intension ring, with maintenance of the ring in its in-tension state until at least full attachment thereof to the peripheral surface of the grinding wheel central aperture. Reducing the tension induces a compressive stress on the peripheral surface of the grinding wheel central aperture which offsets a certain amount of the tensile stresses of rotation, thus allowing operation at higher speed and in greater safety.
  • Radial and tangential stresses in a rotating grinding wheel are necessary values in attaining the resistance against rupture or destructive disintegration at high speeds.
  • the tangential stress is very high at the peripheral wall of the hold and readily acts on the notches and crevices of the rough grinding wheel material.
  • the tangential stress equals the strength of the grinding wheel material and rupture may occur. The bigger the hole, the lower is the circumferential speed which leads to rupture.
  • Wheels without center holes can be used at higher speeds than wheels with center holes. It is known that a ring glued into the inner periphery of the grinding wheel central aperture reduces its tangential stress by exercising radial tensile stresses on the wheel glue or wheel-adhesive layer.
  • both the wheel and reinforcing ring materials have to be considered separately.
  • the radial tensile stress in the joint between the two materials is quite critical because it is supported by the glue or adhesive which in turn is also influenced by the thickness of its layer.
  • the tangential stress drops from the inner to the outer peripheral surface of the steel ring and changes to a noticeably smaller value at thehole of the grinding wheel.
  • this drop is due to the differences of Youngs modulus of elasticity (E) of the two materials (for steel, E---30 10 p,s.i.; for a vitrified grinding wheel body, E approximately 8 l0 psi).
  • E Youngs modulus of elasticity
  • the radial stress in the glue layer increases, however, a small amount when a bigger reinforcing ring is used, this being explainable by the fact that under a higher centrifugal force, the steel ring is strained less than the grinding wheel due to the differences in Youngs modulus.
  • the ratio of the reinforcing interior ring may be chosen in a manner that at a surface speed normally leading to rupture, the tangential stresses in the central bore peripheral surface become generally equal to the ulti mate tensile strength of the grinding wheel and to the radial stress in the glue or adhesive layer.
  • This invention allows even higher speeds and greater safety by disclosing a design, structure and process for tensioning or expanding a reinforcing ring means and maintaining it in an intension state with an expanding means at least until full attachment thereof to the periphery of the grinding wheel cen tral aperture. Subsequent removal of the expansion means reduces the tension in the rings, thereby inducing a compressive force on the periphery of the grinding wheel central aperture. This induced compressive stress will then offset a certain amount of tensile stresses of rotation and allow operation at higher speeds and in greater safety.
  • One embodiment of this invention includes an in-tension ring which is inserted into the periphery of the grinding wheel aperture.
  • the ring may be coated with adhesive either before or after tensioning.
  • either the periphery of the grinding wheel central aperture only, or both the periphery and the ring may be coated prior to the insertion of the in-tension ring.
  • Another embodimentof this invention utilizes an untensioned ring which is inserted into the grinding wheel central aperture prior to putting it in tension.
  • the ring may be coated with adhesive prior to insertion, or only the periphery of the grinding wheel aperture may be coated, with the alternative that both the ring andthe. periphery of the grinding wheel aperture may be coated prior to insertion and subsequent tensioning of the ring.
  • this invention includes an in-tension ring around and in contact with the outer periphery to which there is molded an annular disc formed of abrasive grains held by a curable binder.
  • the ring is maintained in tension until the binder of the in-tension ring and molded disc assembly is fully cured by the application of heat, thereby providing retention of the abrasive grains and attachment of the ring to the inner periphery of the disc.
  • this invention discloses the manufacture of a ring-reinforced grinding wheel including the method steps of applying a curable adhesive means on at least one surface of the interface existing between the outer periphery of the ring and the periphery defining the central aperture of the grinding wheel, and expanding the ring as of its'insertion thereof into the grinding wheel central aperture, this expansion being cluding a ring-shaped reinforcing means around the central axis of rotation of the article concentric to the axis as well as being attached to the periphery defining the central aperture of the article, the improvement therewith which comprises expansion of the reinforcing means as of the insertion thereof into the central aperture, with maintenance of the expansion at least until the full attachment thereof to the abrasive article.
  • FIG. 1 is a perspective view of a grinding wheel, composed of abrasive grains held by a curable binder, molded around the outer periphery of a reinforcing ring, which in accordance with the present invention, is maintained in an intension state at least until full adherence of the ring to the grinding wheel.
  • FIG. 2 is a fragmentary end view of a centrally apertured grinding wheel showing an in-tension ring maintained in that state in accordance with the present invention by an expanding means until full adherence of the ring to the peripheral surface of the grinding wheel central aperture.
  • FIG. 3 is a sectional view taken along line 3-3 of FIG. 2 showing the details of one type of expanding means.
  • FIG. 1 is a perspective view of a disc-type grinding wheel 10, composed of abrasive grains 12 held by curable binder 14 and having sides 16, outer peripheral surface 18, centrally aperture and aperture peripheral surface 22.
  • a reinforcing ring 24 Located within aperture 20 and in intimate contact with peripheral surface 22 is a reinforcing ring 24 having outer peripheral surface 26, central aperture 28, inner peripheral surface 30 and sides 32.
  • Numeral ll denotes the ring-reinforced grinding wheel assembly.
  • FIG. 2 is a fragmentary end view of the same type of grinding wheel 10 and reinforcing ring 24 shown in FIG. 1 with the addition of curable adhesive means 34 located in interface 36, the latter defining the space between grinding wheel aperture peripheral surface 22 and outer peripheral surface 26 of reinforcing ring 24.
  • FIG. 3 which is a sectional view taken along line 3-3 of FIG. 2, best shows expanding mandrel assembly 40 located within central aperture 28 or ring 24.
  • Expanding mandrel assembly 40 is composed of split expander ring 42 having a substantially cylindrical and concentric or coaxial outer surface 44 abutting inner peripheral surface 30 or ring 24 and a tapered inner surface 46 engaging tapered outer surface 50 of centrally apertured and threaded collet 48; apertured retainer plate 52 abutting one side 16 of wheel [0, one side 32 of ring 24 and large end 47 of ring 42; and a bolt 56 having a head 58 restrained by plate 52 with threaded portion 60 retained in collet 48. Clockwise turning of bolt 56 forces tapered outer surface 50 of collet 48 to slide inside split ring 42 on its tapered inner surface 46 thereby expanding split ring 42 and consequently causing expansion or tensioning of reinforcing ring 24.
  • I reinforcing ring 24 which may be made of any suitable material such as steel, fiber glass, or even exotic hightemperature alloys for example, having greater tensile strength than grinding wheel 10 itself, is tensioned or expanded by any expanding means, such as expanding mandrel assembly 40 shown in FIGS. 2 and 3.
  • expanding mandrel assembly 40 shown in FIGS. 2 and 3.
  • wheel 10 composed of abrasive grains I2 suspended in for instance, a curable binder 14 of a type generally used for resinoid-bonded grinding wheels, is molded around in-tension ring 24.
  • a curable binder 14 which could be utilized here, are disclosed in US. Pat. No. 3,098,730 issued to Rowse on Jul. 23, I963.
  • This in-tension ring and disc assembly 11 is then inserted into a kiln or furnace wherein binder 14 is fully cured by the application of heat, thereby providing both for the retention of abrasive grains l2 and for the attachment of ring 24 to aperture peripheral surface 22 of grinding wheel 10.
  • the reinforcing ring expanding means such as expanding mandrel assembly 40, is removed, which reduces the 'ension in reinforcing ring 24, thereby inducing a compressive stress or force on aperture peripheral surface 22 now joined 1y cured binder 14 to outer peripheral surface 26 of reinforcng ring 24.
  • the induced compressive stress or force will then offset a certain amount of the tensile stresses of rotation and pennit operation both at higher speeds and in greater safety.
  • the induced compressive stress or force depends on the degree of tension or expansion initially imparted to reinforcing ring 24, with this degree of tension being determined by both the amount of resultant compressive force tesired and the ultimate tensile strength of binder 14.
  • the a mount of tension of the in-tension reinforcing ring 24 may i :adily be calculated by using the values obtained by measuring ring 24 in both its untensioned (free) and subsequent intmsion states.
  • the amount or ext :nt of tensioning and the ratio of the reinforcing ring 24 may be chosen in a manner that at a surface speed normally leading to rupture, the tangential stresses in grinding wheel aperture peripheral surface 22 become generally equal to the ultimate tensile strength of grinding wheel I0 and to the radial stresses in binder 14 at the junction of grinding wheel aperture peripheral surface 22 and outer peripheral surface 26 of ring 24.
  • this invention is not restricted in use to resin-bonded (resinoid) grinding wheels, but may also be utilized for grinding wheels using other bonding media such as, for example, porcelain-bonded (vitrified) grinding wheels.
  • high firing temperatures generally around 2.300" F.
  • binder 14 will properly wet and adhere to both abrasive grains [2 and outer peripheral surface 26 of ring 24.
  • An example only, of a binder 14, which could be utilized here, is disclosed in US. Pat. No. 2,680,895 issued to Sjogren on Jun. I5, 1954. Suitable nonoxidizing protective furnace atmospheres should also be considered.
  • FIGS. 2 and 3 disclose other embodiments of this invention different from that shown in FIG. 1 in that in FIGS. 2 and 3 reinforcing ring 24 is attached to grinding wheel aperture peripheral surface 22 of an already molded-and-fired grinding wheel 10.
  • grinding wheel 10 may be made of any type of abrasive grains [2 suspended in any of the curable binders 14 as previously noted and reinforcing ring 24 may again be made of any suitable material, such as steel, for example, having greater tensile strength than grinding wheel 10 itself.
  • ring 24 is put in tension with tensioning or expanding means, such as expanding mandrel assembly 40, prior to being inserted into grinding wheel aperture peripheral surface 22.
  • tensioning or expanding means such as expanding mandrel assembly 40
  • the amount of tension is commensurate with values obtained by measuring ring 24 in both its free and in-tension states.
  • the outer peripheral surface 26 of ring 24 may be coated with curable adhesive means 34 either before or after tensioning.
  • either aperture peripheral surface 22 only, or both aperture peripheral surface 22 of grinding wheel [0 and outer peripheral surface 26 of reinforcing ring 24 may be coated with adhesive means 34 prior to the insertion of ring 24 into aperture 20 of grinding wheel [0.
  • Adhesive means 34 after the insertion of ring 24 into aperture 20 of grinding wheel [0, occupies interface 36 located between outer peripheral surface 26 of ring 24 and aperture peripheral surface 22 of grinding wheel [0.
  • adhesive means 34 may be utilized, one example of which is a liquid epoxy glue of the cold-hardening type, commercially available as Agomet Vl made by the Atlas Ago Co. of Wolfgang near Hanan, West Germany.
  • the strength of adhesive means 34 is not only influenced by its composition but also by the thickness of its layer, which should be kept to a minimum.
  • outer peripheral surface 26 of ring 24 is roughened and grinding wheel aperture peripheral surface 22 is solventcleaned prior to coating with adhesive means 34.
  • ring 24 is tensioned or expanded only after its insertion into aperture 20 of grinding wheel 10.
  • the outer peripheral surface 26 of ring 24 may be coated with curable adhesive means 34 prior to the insertion of ring 24 into grinding wheel aperture 20.
  • either aperture peripheral surface 22 only, or both aperture peripheral surface 22 of grinding wheel and outer peripheral surface 26 of reinforcing ring 24 may be coated with adhesive means 34 prior. to the insertion of ring 24 into grinding wheel aperture 20.
  • the amount of tension in ring 24 may be controlled by specifying the amount of torque applied to the expanding means, which amount is initially determined by tests, as previously described, by using the values obtained by measuring ring 24in bothits free and in-tension states prior to insertion.
  • this invention discloses the manufacture of a high-speed annular rotative centrally apertured grinding wheel 11 formed of abrasive grains 12 held together by curable binder l4 and having reinforcing ring 24 attached to grinding wheel aperture peripheral surface 22, including the steps of pretensioning ring 24 and maintaining this tension with an expanding means, such as expanding mandrel assembly 40; molding grinding wheel 10, formed of abrasive grains 12 held by curable binder 14, around and in abutting contact with outer peripheral surface 26 of in-tension ring 24; heating the molded grinding wheel in-tension ring assembly 11 until binder 14 is fully cured, thereby providing both proper retention of abrasive grains l2 and complete attachment of in-tension ring 24 to grinding wheel aperture peripheral surface 22; and removing the expanding means to reduce the tension in ring 24 thereby prestressing or inducing a compressive force on aperture peripheral surface 22 of grinding wheel central aperture 20.
  • a high-speed rotative abrasive article reinforced against destructive disintegration at advanced rotative velocities comprising:
  • annular disc formed of abrasive grains held by a binder and having a central axial aperture
  • an in-tension ring which is inserted into said central aperture and held in the peripheral surface of said aperture by adhesive means, with maintenance of said ring in its intension state until the adhesive means is fully cured.
  • element (c) comprises a ring which is inserted into said central aperture and held on the peripheral surface of said aperture by the adhesive means, said ring immediately upon insertion being tensioned and maintained in a tensioned state until the adhesive means is fully cured.
  • a rotatable annular centrally apertured abrasive article formed of abrasive grains held by a binder including a ringshaped reinforcing means around the central axis of rotation of said article concentric to said axis as well as being attached to the periphery defining the central aperture of said article, the improvement therewith which comprises expansion of said reinforcing means as of the insertion thereof into the central aperture, with maintenance of said expansion at least until the full attachment thereof to said abrasive article.
  • a high-speed rotative abrasive article reinforced against destructive disintegration at advanced rotative velocities comprising:
  • annular disc formed of abrasive grains held by a curable binder which is molded around and in contact with the outer periphery of said ring, with maintenance of said ring in-tension until the binder is fully cured by the application of heat thereby providing proper retention of the abrasive grains and full attachment of said ring to the inner periphery of said disc.
  • step (a) providing a curable adhesive means on at least one surface of the interface located between the outer periphery of said ring and the periphery defining the central aperture of said grinding wheel, is performed after step (b) tensioning said ring and maintaining said tension with an expanding means.
  • step (b) tensioning said ring and maintaining said tension with an expanding means. is performed after step (c) inserting said ring into said central aperture.

Landscapes

  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Polishing Bodies And Polishing Tools (AREA)
US829950A 1969-06-03 1969-06-03 Abrasive structures having a compression-producing reinforcing ring Expired - Lifetime US3571980A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
US82995069A 1969-06-03 1969-06-03

Publications (1)

Publication Number Publication Date
US3571980A true US3571980A (en) 1971-03-23

Family

ID=25255975

Family Applications (1)

Application Number Title Priority Date Filing Date
US829950A Expired - Lifetime US3571980A (en) 1969-06-03 1969-06-03 Abrasive structures having a compression-producing reinforcing ring

Country Status (5)

Country Link
US (1) US3571980A (enrdf_load_stackoverflow)
DE (1) DE2026266A1 (enrdf_load_stackoverflow)
FR (1) FR2049823A5 (enrdf_load_stackoverflow)
GB (1) GB1238145A (enrdf_load_stackoverflow)
NL (1) NL7007890A (enrdf_load_stackoverflow)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4246728A (en) * 1979-10-01 1981-01-27 Leasher Arthur L Conduit end treating tool
US6206766B1 (en) * 1997-05-13 2001-03-27 August Heinr. Schmidt Gmbh & Co. Kg Maschinenfabrik Grinding wheel
CN105904343A (zh) * 2015-02-19 2016-08-31 通用汽车环球科技运作有限责任公司 用于砂轮的快速更换适配器

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2004630A (en) * 1932-12-06 1935-06-11 Krug Carl Grinding disk
US3210892A (en) * 1963-10-30 1965-10-12 Albertson & Co Inc Safety wheel assembly

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2004630A (en) * 1932-12-06 1935-06-11 Krug Carl Grinding disk
US3210892A (en) * 1963-10-30 1965-10-12 Albertson & Co Inc Safety wheel assembly

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4246728A (en) * 1979-10-01 1981-01-27 Leasher Arthur L Conduit end treating tool
US6206766B1 (en) * 1997-05-13 2001-03-27 August Heinr. Schmidt Gmbh & Co. Kg Maschinenfabrik Grinding wheel
CN105904343A (zh) * 2015-02-19 2016-08-31 通用汽车环球科技运作有限责任公司 用于砂轮的快速更换适配器
CN105904343B (zh) * 2015-02-19 2018-12-07 通用汽车环球科技运作有限责任公司 用于砂轮的快速更换适配器

Also Published As

Publication number Publication date
GB1238145A (enrdf_load_stackoverflow) 1971-07-07
FR2049823A5 (enrdf_load_stackoverflow) 1971-03-26
DE2026266A1 (de) 1971-03-25
NL7007890A (enrdf_load_stackoverflow) 1970-12-07

Similar Documents

Publication Publication Date Title
US4138286A (en) Method of forming a part of revolution having a flat shape
CA1208041A (en) Method for balancing mechanical components
US5753165A (en) Process for producing a hard roll
US3332499A (en) Well casing shoe structure
GB1459918A (en) Apparatus and method for making
US3571980A (en) Abrasive structures having a compression-producing reinforcing ring
US20190352999A1 (en) Filament-Reinforced Composite Material with Load-Aligned Filament Windings
US3795078A (en) Segmental cut-off wheel
GB2178117A (en) Clutch driven plates
US3369879A (en) Method of making a peripheral diamond grinding wheel
GB2142702A (en) Lined pipe
US3427759A (en) Prestressed grinding wheel
US2479078A (en) Diamond abrasive wheel
US2703437A (en) Method of making abrasive articles
US2178835A (en) Grinding wheel
US2279486A (en) Segmental abrasive wheel for pulp grinding
US2418883A (en) Anchoring means for abrasive disks
US2081843A (en) Grinding wheel and method of making the same
US2173461A (en) Grinding wheel and method of grinding
US3487590A (en) Reinforced grinding wheel
US3400497A (en) Abrasive disc
US2397101A (en) Abrasive article and method of manufacturing the same
US6402606B1 (en) Grinding wheel having urethane resin bushing in its center mounting hole
US3519508A (en) Method of making a rubber covered steel mill roller
JPH0143076B2 (enrdf_load_stackoverflow)