US4895551A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dynamically balanced drive shaft
Assignee: AO Smith Corp
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Filing: 1987-09-24
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Granted: 1990-01-23
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Expires: 2007-09-24
Abstract
Abstract A dynamically balanced drive shaft. The shaft is preferably formed of fiber reinforced resin and is designed to operate at speeds below the first critical speed. To balance the shaft, a mass or patch of resin containing high density particles, such as metal particles, is applied to one or more locations on the shaft. The patch extends only a portion of the circumference of the shaft and generally has an area less than 10 sq. inches, and generally has a thickness less than 1/16th inch.
Inventors
- 👤 Peter J. Fritz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 18:57
CPC Classifications
F; F16; F16F; F16F15/00; F16F15/32; F16F15/322; F16C; F16C3/00; F16C3/02; F16C3/026
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
83 words
A balanced shaft assembly, comprising a shaft, and at least one patch applied to said shaft, said patch comprising a matrix of resin bonded to the shaft and extending only a portion of the circumference and axial length of said shaft, said patch having a thickness less than 1/16 inch, said particles comprising from 25% to 75% by weight of said patch, said patch having a relatively large surface area in comparison with said thickness whereby stress concentrations around the patch are minimized.
Claim 2
Dependent Claim
83 words
A balanced shaft assembly, comprising a shaft, and at least one patch applied to said shaft, said patch comprising a matrix of resin bonded to the shaft and extending only a portion of the circumference and axial length of said shaft, said patch having a thickness less than 1/16 inch, said particles comprising from 25% to 75% by weight of said patch, said patch having a relatively large surface area in comparison with said thickness whereby stress concentrations around the patch are minimized.
Claim 3
Dependent Claim
20 words
The assembly of claim 1, and including a pair of patches, each patch disposed adjacent an end of said shaft.
Claim 4
Dependent Claim
22 words
the assembly of claim 2, and including a third patch disposed between said pair of patches adjacent the center of said shaft.
Claim 5
Dependent Claim
23 words
The assembly of claim 1, wherein said patch has a composite density in the range of 0.1 to 0.3 lbs per cu. inch.
Claim 6
Dependent Claim
28 words
The assembly of claim 1, wherein said particles are metal and said matrix is selected from the group consisting of a cured thermosetting resin and a thermoplastic resin.
Claim 7
Dependent Claim
14 words
The assembly of claim 1, wherein said shaft is composed of fiber reinforced resin.
Claim 8
Dependent Claim
103 words
A balanced shaft assembly comprising a fiber reinforced resin tubular shaft, at least one mass applied to the shaft at a location to dynamically balance the shaft, said mass including a matrix of a substance capable of adhering to said shaft and containing a multiplicity of finely divided high density particles having a density greater than 0.25 lbs. per cu. inch, said mass having a thickness less than 1/16 inch, said particles comprise from 25% to 75% by weight of said patch, said mass having a relatively large surface area in comparison with said thickness whereby stress concentrations around the mass are minimized.
Claim 9
Dependent Claim
103 words
A balanced shaft assembly comprising a fiber reinforced resin tubular shaft, at least one mass applied to the shaft at a location to dynamically balance the shaft, said mass including a matrix of a substance capable of adhering to said shaft and containing a multiplicity of finely divided high density particles having a density greater than 0.25 lbs. per cu. inch, said mass having a thickness less than 1/16 inch, said particles comprise from 25% to 75% by weight of said patch, said mass having a relatively large surface area in comparison with said thickness whereby stress concentrations around the mass are minimized.
Claim 10
Dependent Claim
29 words
The assembly of claim 7, wherein said particles are composed of metal and said matrix is selected from the group consisting of a thermosetting resin and a thermoplastic resin.
Claim 11
Dependent Claim
18 words
The assembly of claim 8, wherein said metal is iron and said thermosetting resin is an epoxy resin.
Claim 12
Dependent Claim
15 words
The assembly of claim 7, wherein said particles have a size less than 200 mesh.
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) | 1993-01-22 | 1993-07-24 | 1994-01-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-01-22 | 1997-07-24 | 1998-01-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-01-22 | 2001-07-24 | 2002-01-23 | $7700.00 | Window Closed / Lapsed |