Patent US2427850A successfully refreshed from Google Patents.
US5065647A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bit for drilling cast iron
Assignee: NATIONAL INSTITUTE FOR STRATEGIC TECHNOLOGY
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Filing: 1990-08-27
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Granted: 1991-11-19
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Expires: 2010-08-27
Abstract
Abstract Method of making and tool bit construction; the bit has a diametrical blade implant of a two-phase material: a main phase of cemented carbine with diffusion bonded cubic boron nitride insert phases placed at high stress corners of such blade, limited strictly to the radial cutting zone of the bit without penetrating the centering zone.
Inventors
- 👤 Jonathon S. Johnson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:04
CPC Classifications
B; B23; B23P; B23P15/00; B23P15/28; B23P15/32; B23B; B23B51/00; B23B51/0006; B23B51/02; B23B2226/00; B23B2226/12; B23B2226/125; B23B2240/00; B23B2240/08; B23B2251/00; B23B2251/18; B23B2251/50; Y; Y10; Y10T; Y10T408/00; Y10T408/78; Y10T408/81; Y10T408/89; Y10T408/909; Y10T408/9095; Y10T408/9097
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
156 words
A method of adapting a fluted drill bit for more effective drilling of cast iron workpieces, comprising: (a) providing, across the pointed end of said fluted drill bit, a diametrically extending slot; (b) forming a blade of a matrix phase of cemented carbide particles which are hot pressed at a temperature of about 2500° F. and at a pressure in the range of 800,000-1,000,000 psi, said blade being effective to snugly fit within the contours of said slot, said blade being comprised of cemented carbide powder within which is diffusion bonded a pair of insert phases constituted of cubic boron nitride, said insert phases being located at opposite outside corners of said blade and extending radially inwardly no greater than the cutting zone of said pointed end of the fluted drill bit; and (c) after seating said blade within said slot, fixedly securing the carbide surfaces of said blade exposed to the walls of said slot.
Claim 2
Independent Claim
156 words
A method of adapting a fluted drill bit for more effective drilling of cast iron workpieces, comprising: (a) providing, across the pointed end of said fluted drill bit, a diametrically extending slot; (b) forming a blade of a matrix phase of cemented carbide particles which are hot pressed at a temperature of about 2500° F. and at a pressure in the range of 800,000-1,000,000 psi, said blade being effective to snugly fit within the contours of said slot, said blade being comprised of cemented carbide powder within which is diffusion bonded a pair of insert phases constituted of cubic boron nitride, said insert phases being located at opposite outside corners of said blade and extending radially inwardly no greater than the cutting zone of said pointed end of the fluted drill bit; and (c) after seating said blade within said slot, fixedly securing the carbide surfaces of said blade exposed to the walls of said slot.
Claim 3
Independent Claim
151 words
A method of adapting a fluted drill bit for more effective drilling of cast iron workpieces, comprising: (a) providing, across the pointed end of said fluted drill bit, a diametrically extending slot; (b) forming a blade effective to snugly fit within the contours of said slot, said blade being comprised of cemented carbide powder within which is diffusion bonded a pair of insert phases constituted of cubic boron nitride, said insert phases being located at opposite outside corners of said blade and extending radially inwardly no greater than the cutting zone of said pointed end of the fluted drill bit; and (c) after seating said blade within said slot, fixedly securing the carbide surfaces of said blade exposed to the walls of said slot, the interface between said drill bit and cubic boron nitride being 2% or less of the total fixed area of said carbide surfaces to the slot walls.
Claim 4
Independent Claim
151 words
A method of adapting a fluted drill bit for more effective drilling of cast iron workpieces, comprising: (a) providing, across the pointed end of said fluted drill bit, a diametrically extending slot; (b) forming a blade effective to snugly fit within the contours of said slot, said blade being comprised of cemented carbide powder within which is diffusion bonded a pair of insert phases constituted of cubic boron nitride, said insert phases being located at opposite outside corners of said blade and extending radially inwardly no greater than the cutting zone of said pointed end of the fluted drill bit; and (c) after seating said blade within said slot, fixedly securing the carbide surfaces of said blade exposed to the walls of said slot, the interface between said drill bit and cubic boron nitride being 2% or less of the total fixed area of said carbide surfaces to the slot walls.
Claim 5
Dependent Claim
32 words
The method as in claim 2, in which each of said inserts are shaped to fit the contour of said slot as well as the contours of said cutting edges and shank.
Claim 6
Dependent Claim
24 words
The method as in claim 2, in which said cemented carbide powders and cubic boron nitride powder are diffusion bonded independent of said slot.
Claim 7
Dependent Claim
24 words
The method as in claim 2, in which the blade thickness is in the range of 25-35% of the diameter of said tool bit.
Claim 8
Dependent Claim
53 words
The method as in claim 2, in which said pointed end is defined by frontal cutting edges on said conical end face and lateral helical edges along the shank of said tool bit separated by a helical flute and the intersection of said frontal and lateral cutting edges defining two opposed cutting corners.
Claim 9
Dependent Claim
17 words
The method as in claim 6, in which the slot extends to include said two intersecting corners.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1994-11-18 | 1995-05-20 | 1995-11-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-11-18 | 1999-05-20 | 1999-11-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-11-18 | 2003-05-20 | 2003-11-19 | $7700.00 | Window Closed / Lapsed |