US3907371A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drop center truck rim and method of forming same
Assignee: CM-MACK INVESTMENTS Inc A CORP OF DE N/K/A GROTNES METALFORMING SYSTEMS Inc
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Filing: 1974-12-23
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Granted: 1975-09-23
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Expires: 1994-12-23
Abstract
Abstract A method of forming a drop center truck rim from a flat steel strip rolled into the form of a smooth cylinder and welded together along the abutting axial edges. The weld flash build-up on the smooth cylinder is removed before the cylinder is formed into the desired rim profile. The cylinder is then simultaneously subjected to an axial load and external fluid pressure to force the cylinder radially against an internal die to form a circumferential well in the central portion of the cylinder, while flaring the end portions of the cylinder. Next, the low stress areas of the desired rim profile, which are the end portions of the rim, are shear formed to reduce the thickness of the steel cylinder in the end portions, while retaining the original thickness of the flat strip in the central well. The final rim profile is then produced by roll forming, after which the rim is sized.
Inventors
- 👤 Hans Luedi
- 👤 Vernon Fencl
- 👤 Johann T Hess
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 18:09
CPC Classifications
B; B60; B60B; B60B21/00; B60B21/02; B21; B21D; B21D26/00; B21D26/02; B21D26/033; B21D26/043; B21D26/047; B21D53/00; B21D53/26; B21D53/30; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49481; Y10T29/49492; Y10T29/49524; Y10T29/49529
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
104 words
A method of forming a drop center truck rim from a flat steel strip rolled into the form of a smooth cylinder and welded together along the abutting axial edges, said method comprising the steps of positioning a die along the internal surface of the cylinder, said die forming a circumferential well adjacent the central portion of the cylinder, applying fluid pressure to the external surface of the cylinder while applying a compressIve axial load to the ends of the cylinder to deform the cylinder radially inwardly against the internal die and thereby form a circumferential well in the central portion of the cylinder.
Claim 2
Independent Claim
104 words
A method of forming a drop center truck rim from a flat steel strip rolled into the form of a smooth cylinder and welded together along the abutting axial edges, said method comprising the steps of positioning a die along the internal surface of the cylinder, said die forming a circumferential well adjacent the central portion of the cylinder, applying fluid pressure to the external surface of the cylinder while applying a compressIve axial load to the ends of the cylinder to deform the cylinder radially inwardly against the internal die and thereby form a circumferential well in the central portion of the cylinder.
Claim 3
Dependent Claim
49 words
A method of forming a drop center truck rim as set forth in claim 1 wherein the end portions of the cylinder are flexed radially outwardly during the application of said fluid pressure and compressive axial load to facilitate the inward deformation of the central portion of the cylinder.
Claim 4
Dependent Claim
33 words
A method of forming a drop center truck rim as set forth in claim 1 wherein the end portions of the cylinder are flared radially outwardly prior to application of the fluid pressure.
Claim 5
Dependent Claim
37 words
A method of forming a drop center truck rim as set forth in claim 1 wherein weld flash is removed from the rolled and welded strip before the smooth cylinder is formed into the desired rim profile.
Claim 6
Dependent Claim
37 words
A method of forming a drop center truck rim as set forth in claim 1 wherein the low stress areas of the rim are shear formed to reduce the thickness of the steel cylinder in such areas.
Claim 7
Independent Claim
131 words
A method of forming a drop center truck rim from a flat steel strip rolled into the form of a smooth cylinder and welded together along the abutting axial edges, said method comprising the steps of a. applying external fluid pressure to the smooth cylinder while applying a compressive axial load to the ends of the cylinder to force the cylinder radially inward against an internal die and thereby form a circumferential well in the central portion of the cylinder, b. shear forming the low stress areas of the desired rim profile so as to reduce the thickness of the steel cylinder in such areas, c. and roll forming the other areas of the desired rim profile so as to retain the original thickness of the steel strip in such areas.
Claim 8
Independent Claim
131 words
A method of forming a drop center truck rim from a flat steel strip rolled into the form of a smooth cylinder and welded together along the abutting axial edges, said method comprising the steps of a. applying external fluid pressure to the smooth cylinder while applying a compressive axial load to the ends of the cylinder to force the cylinder radially inward against an internal die and thereby form a circumferential well in the central portion of the cylinder, b. shear forming the low stress areas of the desired rim profile so as to reduce the thickness of the steel cylinder in such areas, c. and roll forming the other areas of the desired rim profile so as to retain the original thickness of the steel strip in such areas.
Claim 9
Dependent Claim
50 words
A method of forming a drop center truck rim as set forth in claim 6 wherein the low stress areas that are shear formed are the end portions of the rim so that the original strip thickness is retained in the circumferential well in the central portion of the rim.
Claim 10
Dependent Claim
38 words
A method of forming a drop center truck rim as set forth in claim 6 wherein weld flash is removed from the rolled and welded strip before the resulting smooth cylinder is formed into the desired rim profile.
Claim 11
Dependent Claim
31 words
A method of forming a drop center truck rim as set forth in claim 6 wherein the ends of said cylinder are flared prior to application of said external fluid pressure.
Claim 12
Dependent Claim
25 words
A method of forming a drop center truck rim as set forth in claim 6 which includes the step of sizing the final formed rim.
Claim 13
Dependent Claim
30 words
A method of forming a drop center truck rim as set forth in claim 1 wherein the original rolled flat steel strip has a uniform thickness along its entire length.
Claim 14
Dependent Claim
128 words
A drop center truck rim formed by rolling a flat steel strip into the form of a smooth cylinder and welded together along the abutting axial edges of the strip, removing weld flash from the smooth cylinder, applying external fluid pressure to the smooth cylinder while applying a compressive axial load to the ends of the cylinder to force the cylinder radially against an internal die and thereby form a circumferential well in the central portion of the cylinder, shear forming the low stress areas of the desired rim profile so as to reduce the thickness of the steel cylinder in such areas, and roll forming the other areas of the desired rim profile so as to retain the original thickness of the steel strip in such areas.
Claim 15
Dependent Claim
128 words
A drop center truck rim formed by rolling a flat steel strip into the form of a smooth cylinder and welded together along the abutting axial edges of the strip, removing weld flash from the smooth cylinder, applying external fluid pressure to the smooth cylinder while applying a compressive axial load to the ends of the cylinder to force the cylinder radially against an internal die and thereby form a circumferential well in the central portion of the cylinder, shear forming the low stress areas of the desired rim profile so as to reduce the thickness of the steel cylinder in such areas, and roll forming the other areas of the desired rim profile so as to retain the original thickness of the steel strip in such areas.
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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) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |