Patent US3757474A successfully refreshed from Google Patents.
US3757474A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Curved surface generator
Assignee: Gleason Works
•
Filing: 1971-09-15
•
Granted: 1973-09-11
•
Expires: 1991-09-15
Abstract
Abstract Apparatus for generating complex curved surfaces such as the epitrochoidal bores of rotary combustion engines, e.g., ''''Wankel'''' engines. A workpiece is, in effect, fixed to a first imaginary cylinder which is rolled about the inner circumference of a larger second cylinder. A cylindrical cutting tool is positioned to contact the workpiece along a predetermined machining line which is parallel to the axes of the two imaginary cylinders, the machining line also being fixed relative to the larger of the two cylinders and outside of its outer circumference. The relative movement of the tool and workpiece causes the machining line to generate an eiptrochoidal surface on the workpiece, and this generated surface is maintained theroretically exact by maintaining the axis for the cylindrical cutting surface of the tool in a plane passing through the machining line and through the line of instantaneous tangency between the two imaginary cylinders as the smaller cylinder rolls relatively about the inner circumference of the larger cylinder. This combination of complex relative movements is provided by a relatively simple machine format which includes a drive mechanism utilizing three separately driven rotating gear members. The two members which simulate the rotation of the ''''imaginary'''' generating gears are concentrically mounted and do not intermesh or otherwise run relatively around the circumferences of each other, and all three drive gears rotate about axes which remain substantially fixed relative to each other at all times during machine operation.
Inventors
- 👤 Harry Pedersen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 09:09
CPC Classifications
B; B24; B24B; B24B19/00; B24B19/08; B24B19/09; Y; Y10; Y10S; Y10S451/00; Y10S451/919
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
155 words
Apparatus for generating epitrochoidal and other curved surfaces on a workpiece comprising: frame means; crank means mounted to said frame means for rotation about a crank axis; adjustable bearing means carried by said crank means; work-support means, for holding said workpiece, mounted for rotation about a work-support axis passing through said bearing means parallel to said crank axis for movement with said crank means about said crank axis, the distance between said crank and work-support axes varying in accordance with the adjustment of said bearing means; tool-support means for holding a tool having a cylindrical cutting surface so that said cutting surface passes in proximity to a predetermined stationary machining line parallel to said crank axis, said tool-support means being mounted for oscillation about a tool-support axis which is coincident with said machining line, and drive means for rotating said crank means and work-support means and for oscillating said tool-support means, respectively, in timed relationships.
Claim 2
Dependent Claim
155 words
Apparatus for generating epitrochoidal and other curved surfaces on a workpiece comprising: frame means; crank means mounted to said frame means for rotation about a crank axis; adjustable bearing means carried by said crank means; work-support means, for holding said workpiece, mounted for rotation about a work-support axis passing through said bearing means parallel to said crank axis for movement with said crank means about said crank axis, the distance between said crank and work-support axes varying in accordance with the adjustment of said bearing means; tool-support means for holding a tool having a cylindrical cutting surface so that said cutting surface passes in proximity to a predetermined stationary machining line parallel to said crank axis, said tool-support means being mounted for oscillation about a tool-support axis which is coincident with said machining line, and drive means for rotating said crank means and work-support means and for oscillating said tool-support means, respectively, in timed relationships.
Claim 3
Dependent Claim
36 words
Apparatus according to claim 1 wherein said drive means comprises separately driven first and second members rotatable about axes fixed respective to each other and drivingly engaged respectively to said work-support means and said crank means.
Claim 4
Dependent Claim
23 words
Apparatus according to claim 2 wherein the axes of said first and second rotatable drive members are both coincident with said crank axis.
Claim 5
Dependent Claim
39 words
Apparatus according to claim 2 wherein the axes of said first and second rotatable drive members remain fixed relative to each other when the distance between said crank and work-support axes is varied by adjustment of said bearing means.
Claim 6
Dependent Claim
19 words
Apparatus according to claim 4 wherein Oldham coupling means drivingly engage said first rotating member and said work-support means.
Claim 7
Dependent Claim
20 words
The apparatus of claim 1 further comprising second adjusting means for varying the distance between said crank and tool-support axes.
Claim 8
Dependent Claim
20 words
The apparatus of claim 1 wherein said drive means rotates said crank means and work-support means, respectively, in opposite directions.
Claim 9
Dependent Claim
26 words
The apparatus of claim 1 wherein said tool-support means comprises a second crank means rotatable about a second crank axis parallel to said first crank axis.
Claim 10
Dependent Claim
29 words
The apparatus of claim 8 wherein the distance between said first and second crank axes is greater than the distance between said first crank axis and said work-support axis.
Claim 11
Dependent Claim
20 words
The apparatus of claim 8 wherein said drive means rotates said first and second crank means at the same rate.
Claim 12
Dependent Claim
39 words
Apparatus of claim 1 wherein said drive means includes means for varying the rate of rotation of said crank means and said work-support means and the rate of oscillation of said tool-support means in accordance with their relative positions.
Claim 13
Dependent Claim
246 words
In a machine for generating epitrochoidal and other curved surfaces on a workpiece, said machine having crank means mounted for rotation about a first axis, work-holding means mounted for movement with said crank means about said first axis, said work-holding means also being rotatable simultaneously about a second axis offset from said first axis, and tool-holding means for receiving a tool having an effectively cylindrical cutting surface and positioning said cutting surface in proximity to a stationary machining line parallel to said first axis and located at a predetermined distance from said first axis, the axis of said tool also being substantially parallel to said first axis, the improvement comprising: movable support means for mounting said tool-holding means, for oscillatory movement about a third axis coincident with said machining line, and drive means for separately rotating, respectively, said crank means and said work-holding means, foR timing said separately driven rotations in a relationship predetermined to simulate the relative rotation of a first imaginary cylinder fixed to said work-holding means about the inner circumference of a larger second imaginary cylinder having an axis coincident with said first axis, the distance between said machining line and said first axis being greater than the radius of said second imaginary cylinder, and for oscillating said movable support means to maintain said tool axis at all times so that it lies in an imaginary plane passing through said machining line and through the instantaneous point of tangency between said imaginary cylinders.
Claim 14
Dependent Claim
246 words
In a machine for generating epitrochoidal and other curved surfaces on a workpiece, said machine having crank means mounted for rotation about a first axis, work-holding means mounted for movement with said crank means about said first axis, said work-holding means also being rotatable simultaneously about a second axis offset from said first axis, and tool-holding means for receiving a tool having an effectively cylindrical cutting surface and positioning said cutting surface in proximity to a stationary machining line parallel to said first axis and located at a predetermined distance from said first axis, the axis of said tool also being substantially parallel to said first axis, the improvement comprising: movable support means for mounting said tool-holding means, for oscillatory movement about a third axis coincident with said machining line, and drive means for separately rotating, respectively, said crank means and said work-holding means, foR timing said separately driven rotations in a relationship predetermined to simulate the relative rotation of a first imaginary cylinder fixed to said work-holding means about the inner circumference of a larger second imaginary cylinder having an axis coincident with said first axis, the distance between said machining line and said first axis being greater than the radius of said second imaginary cylinder, and for oscillating said movable support means to maintain said tool axis at all times so that it lies in an imaginary plane passing through said machining line and through the instantaneous point of tangency between said imaginary cylinders.
Claim 15
Dependent Claim
50 words
A machine according to claim 12 wherein said drive means comprises first and second drive members connected for movement, respectively, with said work-holding means and said crank means, each member being separately driven and rotatable according to said predetermined timed relationship about respective axes fixed in relation to each other.
Claim 16
Dependent Claim
21 words
A machine according to claim 13 wherein said first and second drive members rotate about axes coincident with said first axis.
Claim 17
Dependent Claim
48 words
A machine according to claim 12 wherein said crank means includes adjustable bearing means and said work-holding means is mounted so that said second axis passes through said bearing means, the distance between said first and second axes varying in accordance with the adjustment of said bearing means.
Claim 18
Dependent Claim
65 words
A machine according to claim 15 wherein said drive means comprises two separately driven members connected for movement with said crank means and said work-holding means and rotatable about axes coincident with said first axis, the axes of said driven members remaining coincident with said first axis regardless of the distance between said first and second axes as determined by adjustment of said bearing means.
Claim 19
Dependent Claim
21 words
A machine according to claim 16 wherein Oldham coupling means drivingly engage one of said driven members and said work-holding means.
Claim 20
Dependent Claim
53 words
A machine according to claim 12 wherein said drive means comprises two separately driven cylindrical members connected for movement, respectively, with said crank means and said work-holding means, each said cylindrical member being rotatable according to said predetermined timed relationship and each being larger in circumference than the larger of said imaginary cylinders.
Claim 21
Dependent Claim
54 words
The machine according to claim 12 wherein said movable support means is effectively pivoted at said third axis, and wherein said machines further comprises a second crank means operatively engaging said support means and rotatable about a fourth axis, said drive means rotating both said first and second crank means at the same speed.
Claim 22
Dependent Claim
30 words
The machine according to claim 19 wherein the distance between said fourth axis and said first axis is greater than the distance between said first axis and said machining line.
Claim 23
Dependent Claim
23 words
The machine according to claim 1 wherein said tool is a cylindrical grinding wheel having a tool axis parallel to said machine line.
Claim 24
Dependent Claim
49 words
The machine according to claim 21 further comprising wheel dressing means movable relative to said grinding wheel for dressing the surface thereof, said dressing means being positioned to contact the cutting surface of said grinding wheel along a predetermined dressing line which is substantially parallel to said tool axis.
Claim 25
Dependent Claim
16 words
The machine according to claim 22 wherein said dressing line is coincident with said machining line.
Claim 26
Dependent Claim
30 words
The machine according to claim 23 wherein the distance between said dressing line and said crank axis is less than the distance between said crank axis and said machining line.
Claim 27
Dependent Claim
23 words
The machine according to claim 12 further comprising means for moving said tool axis along said imaginary plane relative to said machining line.
Claim 28
Dependent Claim
28 words
The machine according to claim 19 comprising further means carried by said support means for moving said tool axis relative to said machining line along said imaginary plane.
Claim 29
Dependent Claim
35 words
Th machinE according to claim 12 wherein said drive means rotates said crank means about said first axis in a first direction while rotating said work-holding means about the second axis in the opposite direction.
References Cited (Backward Citations)
US2870578A
Cited
GB914981A
Cited
GB1117569A
Cited
US3494388A
Cited
US3595108A
Cited
US3693297A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-09-10 | 1977-03-12 | 1977-09-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-09-10 | 1981-03-12 | 1981-09-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-09-10 | 1985-03-12 | 1985-09-11 | $7700.00 | Window Closed / Lapsed |