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Publication numberUS3921342 A
Publication typeGrant
Publication dateNov 25, 1975
Filing dateDec 17, 1973
Priority dateDec 17, 1973
Also published asCA977970A, CA977970A1
Publication numberUS 3921342 A, US 3921342A, US-A-3921342, US3921342 A, US3921342A
InventorsLawrence Day
Original AssigneeSpitfire Tool & Machine Co Inc
Export CitationBiBTeX, EndNote, RefMan
External Links: USPTO, USPTO Assignment, Espacenet
Lap plate
US 3921342 A
Abstract
A lap plate for a lapping machine, the working surface of which is provided with a pattern of troughs through which an abrasive liquid centrifugally flows during a lapping operation, wherein the depth of the troughs can be varied in ratio to the wear of the surface of the lap plate.
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Description  (OCR text may contain errors)

United States Patent Day 51 Nov. 25, 1975 [54] LAP PLATE 3,128,580 4/1964 Davis 51/209 R 3,324,607 6/1967 Niemiec... [75] Lawrence Mount Prospect m 3,745,645 7/1973 Kurth 241/294 [73] Assignee: Spitfire Tool & Machine Co., Inc.,

Chicago, 11L Primary Examiner-Al Lawrence Smith Assistant Examiner-Margaret M. Joyce 22 Fl (1. D 17, 1973 1 l 8 cc Attorney, Agent, or Firm-Edward C. Threedy [21] Appl. N0.: 425,328

[57] ABSTRACT [52] US. Cl. 51/209 DL [51] Int. Cl 824d 7/06 A lap plate for a lappmg machmei the workmg Surface S 5 1 6 29 DL Of which is provided With a pattern Of troughs through 3 5 209 R which an abrasive liquid centrifugally flows during a lapping operation, wherein the depth of the troughs [56] Reerences Cited can be varied in ratio to the wear of the surface of the UNITED STATES PATENTS 10/1962 Johnson 241/294 lap plate.

2 Claims, 5 Drawing Figures U,S. Patfint Nov. 25, 1975 3,921,342

LAP PLATE SUMMARY OF THE OPERATION In lapping operations, it is important to provide a suitable abrasive grit carried by a lubricating material, such as oil, evenly distributed upon the surface of the rotating lap plate. The removal of stock from the workpieces and the finishing of their lapped surfaces, as well as the resulting wear of the lap plate, are dependent not only on the extent of operation of the lap plate, but also on the uniformity of the abrading operation resulting from the continuous presence of an abrasive liquid over the entire surface of the lap plate.

Thus, it is conventional practice to feed a liquid carrier, such as light oil with abrasive material pollutions in suspension onto the surface of the lap plate during its rotational lapping operation.

In order to be effective it is necessary that the abrasive material be continuously maintained and evenly distributed upon the surface of the lap plate during its active period of abrading and then centrifugally removed beyond the periphery of the lap plate. To effect centrifugal removal of spent abrasive material (material containing the stock removed from the workpieces as well as from the surface of the lap itself), heretofore the surfaces of prior lap plates were provided with a pattern of troughs through which the abrasive material flowed. However, the depth of the troughs was such that they effected removal of all of the abrasive liquid from the lap surface.

It is the purpose of the invention to provide a lap plate having its lapping surface provided with a pattern of troughs, the depth of which can be maintained so as to effectively remove only spent abrasive fluids while maintaining continuously a usable amount of abrasive fluid adjacent the surface of the rotating lap plate.

DESCRIPTION OF THE INVENTION The invention will be best understood by reference to the accompanying drawings showing one form of the invention, and in which:

FIG. 1 is a fragmentary perspective view of a lapping machine containing the invention;

FIG. 2 is a top plan view of the lap plate of the invention;

FIG. 3 is a fragmentary side elevational detailed sectional view of the lap plate of the invention;

FIG. 4 is fragmentary sectional view of one form of the invention; and

FIG. 5 is a fragmentary detailed sectional view of another form of the invention.

The conventional lapping machine, such as shown in U.S. Pat. No. 3,032,937 dated May 8, 1962, and one which may include the present invention, includes a base havng a circular top wall 11 within which is rotatably mounted a circular lap plate 12. Mounted upon the surface of the lap plate 12 are one or more work 'holders or wear rings 13, which are adapted to be radially positioned upon the lap plate 12. A pressure plate 14 is positioned within the wear ring 13 and bears upon the work therein which is to be lapped. So that the work may be placed in and removed from the work holder 13, the pressure plate 14 is supported for vertical movement relative thereto by a unit 15 constructed and operated in accordance with the aforesaid patent. The functional lapping machine is provided with a structure by which a liquid abrasive may be dispensed upon a surface of the lap plate 12. Such a liquid abrasive dispenser is indicated at 16 and may be of the construction and operation described and shown in U.S. Pat. No. 3,261,510 dated July 19, 1966. This abrasive dispenser includes a delivery chute 17 through which the abrasive material is caused to flow onto a conically shaped dispensing cup 18 removably positioned in a centrally formed well 19 in the lap plate 12.

By the use of the foregoing structure, an abrasive liquid may be dispensed onto the cup 18 and from thence over the lapping surface of the lap plate 12. This dispensing action is caused not only by centrifugal force created by the rotational movement of the lap plate 12, but also through the presence of the work holder 13 which is caused to rotate as a reaction to the rotation of the lap plate 12. The work holder 13 is caused to overlie a portion of the cup 18 so as to interrupt the overflow of the abrasive liquid therefrom and by capillary action created by rotation of the work holder 13, the liquid is evenly spread in a uniform film over the working surface of the lap plate 12.

The lap plate 12 may have its surface deformed by a pattern of troughs. This pattern may take the form of radially extending troughs such as that shown in the aforementioned patents, or it may spirally extend from the well 19 to the outer edge of the lap or, as shown in FIGS. 1 and 2 of the drawings, it may be formed in a cross-hatched pattern.

These troughs 20 are formed so as to intersect substantially at right angles with respect to each other so as to extend completely across the lap plate 12 and so as to provide certain of the troughs, such as 21-22-23 as well as 24-25-26, with open communication to the well 19 formed in the center of the lap plate 12.

It is desirable to have the troughs 20 formed of a depth of 2.250 inches and of a width of 0.125 inch, although the depth and width may vary according to the material from which the lap plate 12 is constructed. Each of the troughs 20 is filled with a non-abrasive, non-soluble material 27 up to 0.0625 to 0.1875 inch of the top surface 28 of the lap plate 12, as shown in FIG. 4

As the lapping machine is operated, metal stock from the workpieces as well as from the surface of the lap plate 12, is, through the presence of the abrasive liquid, removed and suspended in the abrasive liquid. It is desirable to remove the spent abrasive liquid upon the introduction of fresh abrasive fluid onto the surface 28 of the lap plate 12. This is accomplished by causing the abrasive material to move not only over the lap surface 28 of the lap plate 12, but also through the troughs 20 formed therein. Because of the cross-hatched pattern of arranging the troughs 20, the centrifugal flow of the abrasive fluid toward the peripheral edge 29 of the lap plate 12, is through a tortious path by reason of the fact that the centrifugal force resulting from rotation of the lap plate 12 will extend through different lengths of troughs. For example, as shown in FIG. 2, when the lap plate 12 rotates counterclockwise, the centrifugal force will follow the trough in the direction of the arrow A and, as the lap plate 12 continues to rotate, that directional force will change and follow the direction of the arrow B, causing the abrasive liquid to follow such a changing path until it reaches the periphery 29 of the lap plate 12 where it is dispensed off the lap surface 28.

By filling the troughs 20 with the non-abrasive, nonsoluble filler material 27, the unspent abrasive liquid is maintained adjacent the working surface 28 of the lap plate 12 and by its continuous presence continuously functions in the manner hereinbefore noted.

As the surface 28 of the lap plate 12 wears and approaches the upper surface 30 of the filler material 27, such material through the use of a simple gauged tool may be routed out to the depth desired. Consequently, as the depth of the troughs may be maintained at the most efficient level in ratio to the work surface of the lap plate, the lapping machine does not have to be shut down for any material length of time for resurfacing of the lap surface or replacement of the lap plate.

In FIG. 5, I show a modified method of filling the troughs 20 formed in the lap plate 12. In this modified form, the filler material 31 is placed in the troughs in layers separated by a readily removable strip 32. Thus, as it becomes necessary to regulate the depth of the troughs, one need only to strip off the separating strip 32, leaving intact a layer of filler material 31 at the prescribed depth desired.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. 1, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations and modifications as come within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire to protect by Letters Patent is:

1. A rotatable lap plate for a lapping machine over which an abrasive liquid is caused to flow during a lapping operation, comprising a. a substantially circular body carried in a horizontal plane by the machine and providing a working surface over which the abrasive liquid flows,

b. means formed in said body interrupting said working surface and into and through which the abrasive liquid flows from said working surface,

. a removable filler in said means below said working surface of said body determining the depth of said means so as to regulate the amount of abrasive liquid flowing therethrough and being gradually removable so as to maintain its relation to said working surface and the depth of said means in relation to the wear of said working surface of said body caused by the lapping operation,

(1. and removable means embedded in said filler separating it into individual readily removable strips.

2. A rotatable lap plate as defined by claim 1, wherein said filler is formed from a non-abrasive nonsoluble material having a hardness less than the hardness of said body so as to be easily removed from said means formed in said body.

Patent Citations
Cited PatentFiling datePublication dateApplicantTitle
US3059863 *Apr 6, 1959Oct 23, 1962Bolton John W & Sons IncSegmental filling for refiner plugs
US3128580 *Jan 30, 1963Apr 14, 1964Super CutComposite lap for grinding and polishing machines
US3324607 *Aug 13, 1964Jun 13, 1967Super CutRotary grinding tool with interrupted abrasive helicoid
US3745645 *Aug 5, 1971Jul 17, 1973Voith Gmbh J MMethod of manufacture and operation of ribbed member for treatment of fibrous suspensions
Referenced by
Citing PatentFiling datePublication dateApplicantTitle
US4019289 *Feb 23, 1976Apr 26, 1977Clayton Paul KorverReplaceable lens surfacing pad with integral wear indicating pattern
US4821461 *Nov 23, 1987Apr 18, 1989Magnetic Peripherals Inc.Textured lapping plate and process for its manufacture
US5022191 *Nov 13, 1989Jun 11, 1991Lam-Plan S.A.Polishing plate
US5131190 *Jan 31, 1991Jul 21, 1992C.I.C.E. S.A.Lapping machine and non-constant pitch grooved bed therefor
US6099390 *Apr 5, 1999Aug 8, 2000Matsushita Electronics CorporationPolishing pad for semiconductor wafer and method for polishing semiconductor wafer
US6135856 *Dec 17, 1997Oct 24, 2000Micron Technology, Inc.Apparatus and method for semiconductor planarization
US6585559Mar 31, 2000Jul 1, 2003Engis CorporationModular controlled platen preparation system and method
US6602108May 17, 2002Aug 5, 2003Engis CorporationModular controlled platen preparation system and method
US7520800Aug 16, 2004Apr 21, 2009Duescher Wayne ORaised island abrasive, lapping apparatus and method of use
US7632434Apr 14, 2004Dec 15, 2009Wayne O. DuescherAbrasive agglomerate coated raised island articles
US7840300 *May 31, 2007Nov 23, 2010Robert Arthur HarkerFull spectrum lapidary 3D image scanner and method
US8062098Jul 7, 2008Nov 22, 2011Duescher Wayne OHigh speed flat lapping platen
US8256091Jul 30, 2008Sep 4, 2012Duescher Wayne OEqual sized spherical beads
US8545583Jan 5, 2005Oct 1, 2013Wayne O. DuescherMethod of forming a flexible abrasive sheet article
US8801497May 21, 2010Aug 12, 2014Rdc Holdings, LlcArray of abrasive members with resilient support
US8808064Oct 18, 2011Aug 19, 2014Roc Holdings, LLCAbrasive article with array of composite polishing pads
US8840447Mar 26, 2012Sep 23, 2014Rdc Holdings, LlcMethod and apparatus for polishing with abrasive charged polymer substrates
US8926411Oct 28, 2011Jan 6, 2015Rdc Holdings, LlcAbrasive article with array of composite polishing pads
US8944886Nov 4, 2011Feb 3, 2015Rdc Holdings, LlcAbrasive slurry and dressing bar for embedding abrasive particles into substrates
US9205530Jul 7, 2010Dec 8, 2015Seagate Technology LlcLapping a workpiece
US9221148Mar 19, 2012Dec 29, 2015Rdc Holdings, LlcMethod and apparatus for processing sliders for disk drives, and to various processing media for the same
US9522454Dec 17, 2012Dec 20, 2016Seagate Technology LlcMethod of patterning a lapping plate, and patterned lapping plates
US20040235406 *Apr 14, 2004Nov 25, 2004Duescher Wayne O.Abrasive agglomerate coated raised island articles
US20080067382 *May 31, 2007Mar 20, 2008Robert Arthur HarkerFull spectrum lapidary 3D image scanner and method
US20100330890 *Apr 2, 2010Dec 30, 2010Zine-Eddine BoutaghouPolishing pad with array of fluidized gimballed abrasive members
EP0370843A1 *Oct 19, 1989May 30, 1990Societe Dite: Lam-Plan S.A.Polishing plate
EP0960693A2 *May 25, 1999Dec 1, 1999Speedfam Co., Ltd.A polishing machine
EP0960693A3 *May 25, 1999Sep 4, 2002Speedfam Co., Ltd.A polishing machine
WO2000059644A1 *Mar 31, 2000Oct 12, 2000Engis CorporationModular controlled platen preparation system and method
WO2011002881A1Jun 30, 2010Jan 6, 2011Zine-Eddine BoutaghouPolishing pad with array of gimballed abrasive segments
Classifications
U.S. Classification451/550
International ClassificationB24B37/04, B24D7/06
Cooperative ClassificationB24D7/06, B24B37/26
European ClassificationB24B37/26, B24D7/06
Legal Events
DateCodeEventDescription
Mar 7, 1991ASAssignment
Owner name: GENERAL SIGNAL CORPORATION, A CORP. OF NY
Free format text: SECURITY INTEREST;ASSIGNOR:SPITFIRE TOOL & MACHINE CO., INC., A CORP. OF DE (MERGED INTO);REEL/FRAME:005642/0064
Effective date: 19831215
Owner name: NEW SPITFIRE, INC., A CORP. OF DE
Free format text: MERGER;ASSIGNORS:SPITFIRE TOOL & MACHINE CO., INC., A CORP. OF IL (MERGED INTO);GENERAL SIGNAL CORPORATION, A CORP. OF NY (CHANGED INTO);REEL/FRAME:005642/0052
Effective date: 19810428
Mar 7, 1991AS03Merger
Owner name: GENERAL SIGNAL
Owner name: NEW SPITFIRE, INC., A CORP. OF DE
Effective date: 19810428
Owner name: SPITFIRE TOOL & MACHINE CO., INC., A CORP. OF IL (
Mar 7, 1991AS06Security interest
Owner name: GENERAL SIGNAL CORPORATION, A CORP. OF NY
Owner name: SPITFIRE TOOL & MACHINE CO., INC., A CORP. OF DE (
Effective date: 19831215
Feb 25, 1991AS02Assignment of assignor's interest
Owner name: GENERAL SIGNAL CORPORATION, A CORP. OF NY
Effective date: 19901019
Owner name: SPEEDFAM CORPORATION, 509 NORTH THIRD AVE., DES PL
Feb 25, 1991ASAssignment
Owner name: SPEEDFAM CORPORATION, 509 NORTH THIRD AVE., DES PL
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNOR:GENERAL SIGNAL CORPORATION, A CORP. OF NY;REEL/FRAME:005610/0752
Effective date: 19901019