Patent US3979779A successfully refreshed from Google Patents.
Patent US3584718A successfully refreshed from Google Patents.
US3584718A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Wear surfaces of clutches, flywheels and the like
Assignee: Schiefer Mfg Co
•
Filing: 1969-06-02
•
Granted: 1971-06-15
•
Expires: 1989-06-02
Abstract
Abstract The pressure plate and flywheel of a clutch and flywheel assembly each has a wear surface defined by a coating which acts as a heat barrier to prevent excessive temperature increases in the substrate of the coatings. The coatings are of A1203 applied by flame plating. The coatings are characterized by their hardness of from about 700 to about 950 VPN300, a porosity of about 2 to about 3 percent, a bond strength to each of the substrates of about 6,000 to about 9,000 p.s.i., a density of about 3.40 gm/cc., a modulus of rupture of about 20,000 p.s.i., a coefficient of thermal expansion of about 3.9 in./in./*F. X 10 6, a thermal conductivity of from about 20 to about 40 BTU/(hr.) (ft.2) (*F./in.), and an operational temperature range of from about ambient to about 1,800* F.
Inventors
- 👤 Paul Schiefer
- 👤 James D Mcfarland Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 14:12
CPC Classifications
F; F16; F16D; F16D13/00; F16D13/22; F16D13/38; F16D13/46; F16D13/48; F16D13/50; F16D65/00; F16D65/02; F16D65/12; F16D65/127; F16D69/00; F16D69/02; F16D69/027; Y; Y10; Y10T; Y10T428/00; Y10T428/31
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
62 words
In combination a clutch and flywheel assembly of the type having a selectively axially movable pressure plate for engaging a clutch disc assembly with a flywheel assembly, the pressure plate and the flywheel assembly each having a wear surface for rotational, frictional engagement with the clutch disc assembly, an improvement which comprises a coating of Al2O3 on each of the wear surfaces.
Claim 2
Dependent Claim
62 words
In combination a clutch and flywheel assembly of the type having a selectively axially movable pressure plate for engaging a clutch disc assembly with a flywheel assembly, the pressure plate and the flywheel assembly each having a wear surface for rotational, frictional engagement with the clutch disc assembly, an improvement which comprises a coating of Al2O3 on each of the wear surfaces.
Claim 3
Dependent Claim
36 words
The improvement claimed in claim 1 wherein: each of the coatings is from about 8 to about 10 percent alpha Al2O3, about 88 percent gamma Al2O3, and from about 2 to about 4 percent beta Al2O3.
Claim 4
Dependent Claim
70 words
The improvement claimed in claim 2 wherein: the coatings have a cross-sectional hardness of from about 700 to about 950 VPN300, a bond strength to the pressure plate and the flywheel assembly of from about 6,000 to about 9,000 p.s.i., a density of about 3.38 gm/cc., a coefficient of thermal expansion of about 3.9 in./in./*F. X 10 6, and a thermal conductivity of from about 20 to about 40 BTU/(hr.)(ft.2)(*F./in.).
Claim 5
Dependent Claim
62 words
The improvement claimed iN claim 1 wherein: the smoothness of the wear surfaces is from about 60 to about 120 RMS, the coating''s thickness is from about 0.003 to about 0.006 inch, the circumferential deviation in thickness of each of the coatings is no more than about 0.0005 inch, and the deviation in radial thickness is no more than about 0.001 inch.
Claim 6
Dependent Claim
67 words
The improvement claimed in claim 4 wherein: the clutch disc assembly is of the hub damping type having a hub damping of from about 0.060 to about 0.120 of an inch at about 70 foot-pounds of torque applied at about 7 1/2 inches from the axis of rotation of the clutch disc assembly, the smoothness of the wear surfaces being from about 70 to about 85 RMS.
Claim 7
Dependent Claim
69 words
The improvement claimed in claim 5 wherein: the coatings have a cross-sectional hardness of from about 700 to about 950 VPN300, a bond strength to the pressure plate and the flywheel assembly of from about 6,000 to about 9,000 p.s.i., a density of about 3.38 gm/cc., a coefficient of thermal expansion of about 3.9 in./in./*F. X 10, and a thermal conductivity of from about 20 to about 40 BTU/(hr.)(ft.2)(*F./in.).
Claim 8
Dependent Claim
36 words
The improvement claimed in claim 6 wherein: each of the coatings is from about 8 to about 10 percent alpha Al2O3, about 88 percent gamma Al2O3, and from about 2 to about 4 percent beta Al2O3.
Claim 9
Dependent Claim
28 words
In combination with a pressure plate of the type used in a clutch assembly, said pressure plate having a wear surface, an improved wear surface coating comprising Al2O3.
Claim 10
Dependent Claim
28 words
In combination with a pressure plate of the type used in a clutch assembly, said pressure plate having a wear surface, an improved wear surface coating comprising Al2O3.
Claim 11
Dependent Claim
35 words
The improvement claimed in claim 8 wherein the wear coating is from about 8 to about 10 percent alpha Al2O3, about 88 percent gamma Al2o3, and from about 2 to about 4 percent beta Al2O3.
Claim 12
Dependent Claim
56 words
The improvement claimed in claim 9 wherein the wear coating has a smoothness of from about 60 to about 120 RMS, a thickness of from about 0.003 to about 0.006 inch, a circumferential deviation in thickness of no more than about 0.0005 inch, and a radial deviation in thickness of no more than about 0.001 inch.
Claim 13
Dependent Claim
67 words
The improvement claimed in claim 10 wherein: the wear coating has a cross-sectional hardness of from about 700 to about 950 VPN300, a bond strength to the pressure plate of from about 6,000 to about 9,000 p.s.i., a density of about 3.38 gm/cc., a coefficient of thermal expansion of about 3.9 in./in./*F. X 10 6, and a thermal conductivity of from about 20 to about 40 BTU/(hr.)(ft.2)(*F./in.).
Claim 14
Dependent Claim
33 words
In combination with a flywheel assembly of the type used in a clutch assembly including a pressure plate having a wear surface, the improvement wherein said wear surface has a coating comprising Al2O3.
Claim 15
Dependent Claim
33 words
In combination with a flywheel assembly of the type used in a clutch assembly including a pressure plate having a wear surface, the improvement wherein said wear surface has a coating comprising Al2O3.
Claim 16
Dependent Claim
35 words
The improvement claimed in claim 12 wherein the wear coating is from about 8 to about 10 percent alpha Al2O3, about 88 percent gamma Al2O3, and from about 2 to about 4 percent beta Al2O3.
Claim 17
Dependent Claim
56 words
The improvement claimed in claim 13 wherein the wear coating has a smoothness of from about 60 to about 120 RMS, a thickness of from about 0.003 to about 0.006 inch, a circumferential deviation in thickness of no more than about 0.005 inch, and a radial deviation in thickness of no more than about 0.001 inch.
Claim 18
Dependent Claim
66 words
The improvement claimed in claim 15 wherein: the wear coating has a cross-sectional hardness of from about 700 to about 950 VPN300, a bond strength to the pressure plate of from about 6,000 to about 9,000 p.s.i., a density of about 3.38 gm/cc., a gm/cc., thermal expansion of about 3.9 in./in./*F. X 10 6, and a thermal conductivity of from about 20 to about 40 BTU/(hr.)(ft.2)(*F./in.).
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) | 1974-06-14 | 1974-12-14 | 1975-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-06-14 | 1978-12-14 | 1979-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-06-14 | 1982-12-14 | 1983-06-15 | $7700.00 | Window Closed / Lapsed |