US4855927A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Complex curved surface creation method
Assignee: Fanuc Corp
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Filing: 1986-07-18
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Granted: 1989-08-08
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Expires: 2006-07-18
Abstract
Abstract The invention relates to a method of creating a complex curved surface (CPS) comprising at least two three-dimensional curved surfaces (10a, 10b), particularly a method of creating a complex curved surface in which roundness is provided at a portion where first and second curved surfaces intersect. In the curved surface creation method, rounding is performed by obtaining normal vectors V 1 , V 2 of first and second curved surfaces (10a, 10b) at a point of intersection P 0 of first and second section curves (11, 12) obtained when the first and second curved surfaces are cut by a section (13) perpendicular to the XY plane, calculating an angle θ defined by V 1 ×V 2 and a normal vector V of the section (13), calculating R' in accordance with the equation R'=(1+1/|cosθ|)·R/2 when roundness of radius R is commanded, and inserting a circular arc of radius R' at the portion where the first and second curved surfaces intersect. R' is the average value of the major axis (=R/|cosθ|) and minor axis (=R) of an ellipse.
Inventors
- 👤 Masaki Seki
- 👤 Norihisa Amano
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 16:28
CPC Classifications
G; G05; G05B; G05B19/00; G05B19/02; G05B19/18; G05B19/402; G05B19/41; G05B2219/00; G05B2219/30; G05B2219/35; G05B2219/35151
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
164 words
A method of creating a complex curved machining surface in which a rounded section curve is provided where first and second curved machining surfaces intersect, comprising the steps of: obtaining normal vectors V 1 , V 2 of the first and second curved machining surfaces at a point of intersection P 0 of first and second section curves obtained when said first and second curved machining surfaces are cut by a section perpendicular to the XY plane, when the normal vectors originate at the point of intersection P 0 of the first section curve, the second section curve and the perpendicular section; calculating an angle θ defined by V 1 ×V 2 and a normal vector V of said perpendicular section; calculating R' in accordance with the equation R'=(1+1/|cos θ|) R/2 when a rounded section curve of radius R is desired; inserting a circular arc of radius R' where the first and second curved machining surfaces intersect; and machining the complex curved machining surface.
Claim 2
Independent Claim
164 words
A method of creating a complex curved machining surface in which a rounded section curve is provided where first and second curved machining surfaces intersect, comprising the steps of: obtaining normal vectors V 1 , V 2 of the first and second curved machining surfaces at a point of intersection P 0 of first and second section curves obtained when said first and second curved machining surfaces are cut by a section perpendicular to the XY plane, when the normal vectors originate at the point of intersection P 0 of the first section curve, the second section curve and the perpendicular section; calculating an angle θ defined by V 1 ×V 2 and a normal vector V of said perpendicular section; calculating R' in accordance with the equation R'=(1+1/|cos θ|) R/2 when a rounded section curve of radius R is desired; inserting a circular arc of radius R' where the first and second curved machining surfaces intersect; and machining the complex curved machining surface.
Claim 3
Dependent Claim
294 words
A complex curved machining surface creation method according to claim 1, wherein a point of intersection of the first and second curves is denoted by P 0 , straight line approximation points located one after another from the point of intersection P 0 to a starting point of the first curve are denoted by P i (i=0, -1, -2, . . . ) straight line approximation points located one after another from the point of intersection P 0 to an end point of the second curve are denoted by P j (j=0, 1, 2, . . . ), and said step of inserting comprises: performing operations of setting P -S =P i , P -E =P i-1 , P S =P j and P E =P j+1 (where i, j each have an initial value of 0), and obtaining points of tangency P -T , P T at which two straight lines P -S P -E and P S P E are tangent to a circle of radius R, where P S , P E , P -S and P -E are end points of the straight lines; determining whether the points of tangency P -T , P T lie between P -E -P 0 and P 0 -P E , respectively; designating a circular arc P -T P T as the rounded section curve inserted at the intersection if the points of tangency P -T , P T lie between P -E -P 0 , and executing the steps of performing, determining and designating, with the operation of setting i=i-1 being performed if P -T does not lie between P -E -P 0 and the operation of setting j=j+1 being performed if P T does not lie between P 0 -P E .
Claim 4
Dependent Claim
56 words
A complex curved machining surface creation method according to claim 2, wherein said step of executing includes: calculating a distance D between P -S and P S ; and determining whether said distance D is greater than 2·R' and, if D is greater than 2·R', indicating that rounding having the radius R is impossible to perform.
Claim 5
Dependent Claim
287 words
A complex curved machining surface creation method according to claim 3, wherein said step of designating includes: determining whether the point of tangency P -T lies between P -E `P -S and whether the point of tangency P T lies between P S -P E ; designating line segment P i-1 P -T , arc P -T P T and line segment P T P j+1 as the complex curved machining surface if the points of tangency P -T , P T lie between P -E -P -S and between P E -P S , respectively; designating line segment P i-1 P -T , arc P -T P T , line segment P T P j and line segment P j P j+1 as the complex curved machining surface if the point of tangency P -T lies between P -E -P -S and the point of tangency P T does not lie between P E -P S ; designating line segment P i-1 P i , line segment P i P -T , arc P -T P T and line segment P T P j+1 as the complex curved machining surface if the point of tangency P -T does not lie between P -E -P -S and the point of tangency P T lies between P E -P S ; and designating line segment P i-1 P i , line segment P i P -T , arc P -T P T , line segment P T P j and line segment P j P j+1 as the complex curved machining surface if the points are tangency P -T , P T do not lie between P -E -P -S and between P E -P S , respectively.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-07 | 1993-02-06 | 1993-08-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-07 | 1997-02-06 | 1997-08-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-07 | 2001-02-06 | 2001-08-08 | $7700.00 | Window Closed / Lapsed |