US4274372A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Lightweight piston for internal combustion engines
Assignee: Karl Schmidt GmbH
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Filing: 1979-09-20
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Granted: 1981-06-23
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Expires: 1999-09-20
Abstract
Abstract In a cast light-alloy piston having a skirt which is recessed adjacent to the piston pin bosses, the two sides of the skirt are unsymmetrical with respect to the piston pin bosses. For an improved adaptation to the different conditions of operation of the engine, the skirt is connected to the piston pin bosses on one side by supporting ribs which extend at an angle of 30 to 60 degrees to the piston pin axis, and on the other side by supporting ribs extending at an angle of 90° to the piston pin axis.
Inventors
- 👤 Walter Kelm
- 👤 Ulrich Landau
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:21
CPC Classifications
F; F16; F16J; F16J1/00; F16J1/04; F16J1/06; F02; F02F; F02F3/00; F02F3/02; F05; F05C; F05C2201/00; F05C2201/04; F05C2201/0433; F05C2201/0448; F05C2251/00; F05C2251/04; F05C2251/042
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
93 words
A cast light-alloy piston comprising a skirt, piston pin bosses, said skirt being recessed adjacent to said bosses, said skirt being non-symmetrical on both sides of the plane of the piston pin, said skirt (a) being connected on one side to said piston pin bosses by first supporting ribs which extend at an angle of 30 to 60 degrees to the piston pin axis, (b) being connected on the other side to the piston pin bosses by second supporting ribs which extend at an angle of 90 degrees to the piston pin axis.
Claim 2
Dependent Claim
93 words
A cast light-alloy piston comprising a skirt, piston pin bosses, said skirt being recessed adjacent to said bosses, said skirt being non-symmetrical on both sides of the plane of the piston pin, said skirt (a) being connected on one side to said piston pin bosses by first supporting ribs which extend at an angle of 30 to 60 degrees to the piston pin axis, (b) being connected on the other side to the piston pin bosses by second supporting ribs which extend at an angle of 90 degrees to the piston pin axis.
Claim 3
Dependent Claim
35 words
A piston according to claim 1 wherein one side of said skirt is connected to the piston pin bosses by first supporting ribs extending at an angle of 45 degrees to the piston pin axis.
Claim 4
Dependent Claim
20 words
A piston according to claim 1 wherein said second supporting ribs extend 65 to 75 percent of the piston diameter.
Claim 5
Dependent Claim
46 words
A piston according to claim 1 wherein at least one side of said skirt is separated on 80 to 90 degrees of the periphery from the head of said piston by a transverse slot, said slot being disposed in the lowermost ring groove of said piston.
Claim 6
Dependent Claim
44 words
A piston according to claim 1 wherein a segment-shaped expansion control member of steel is disposed adjacent to the top edge of said skirt on the inside peripheral surface of at least one load-carrying skirt portion and is locked in said piston pin bosses.
Claim 7
Dependent Claim
38 words
A piston according to claim 5 wherein said segment-shaped expansion control member is supported by a bead which extends as an extension from the inside surface of the head of said piston and between said piston pin bosses.
Claim 8
Dependent Claim
22 words
A piston according to claim 5 wherein said control member is exposed within said lowermost ring groove throughout substantially its entire periphery.
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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) | 1984-06-22 | 1984-12-22 | 1985-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-06-22 | 1988-12-22 | 1989-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-06-22 | 1992-12-22 | 1993-06-23 | $7700.00 | Window Closed / Lapsed |