US4231247A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dent straightening tool
Assignee: Individual
•
Filing: 1979-05-07
•
Granted: 1980-11-04
•
Expires: 1999-05-07
Abstract
Abstract A dent straightening tool having a manually graspable handle affixed to one end of an elongate shaft and a work piece engaging, helically threaded member affixed to the opposite end of the shaft. The threaded member has a substantially constant radius root with a blunt tip provided at the distal end of the root. The thread begins from a minimum radius at the blunt tip and then progressively increases in radius along the length of the root to attain a size substantially larger than the radius of the root so that the depth of the thread is substantially deeper than the radius of the root. Also, the flat length of the thread, as measured along the root, is at least one-half of the pitch length of the thread.
Inventors
- 👤 Charles R. Haydon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:57
CPC Classifications
B; B21; B21D; B21D1/00; B21D1/06; Y; Y10; Y10S; Y10S72/00; Y10S72/705
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
218 words
A tool for use in straightening a dent in a sheet metal skin, comprising: (a) an elongate shaft; (b) an integral handle at one end of said shaft; and (c) work piece engaging, helical threads integrally formed in the opposite end of said shaft, said threads comprising, (1) a substantial constant diameter root portion; (2) a tapered thread portion disposed along the length of said root; (3) a blunt tip at the distal end of said thread portion opposite said handle; and (4) said thread portion beginning from a minimum radius at said tip and progressively increasing in radius along the length of said root to a depth substantially greater than the radius of said root portion to thereby provide a thread with a relatively large anvil surface area disposed substantially perpendicular to the length of said root, so that when the tool is threadably engaged within an initial hole provided in the dented sheet metal of a diameter slightly larger than the root diameter, only a narrow slit is formed in the dented sheet metal extending radially from the initial hole for a distance corresponding to the maximum radius of said threads to thereby provide a substantial anvil contacting surface against which the dented sheet metal can bear when the tool is pulled in an outwardly direction.
Claim 2
Dependent Claim
218 words
A tool for use in straightening a dent in a sheet metal skin, comprising: (a) an elongate shaft; (b) an integral handle at one end of said shaft; and (c) work piece engaging, helical threads integrally formed in the opposite end of said shaft, said threads comprising, (1) a substantial constant diameter root portion; (2) a tapered thread portion disposed along the length of said root; (3) a blunt tip at the distal end of said thread portion opposite said handle; and (4) said thread portion beginning from a minimum radius at said tip and progressively increasing in radius along the length of said root to a depth substantially greater than the radius of said root portion to thereby provide a thread with a relatively large anvil surface area disposed substantially perpendicular to the length of said root, so that when the tool is threadably engaged within an initial hole provided in the dented sheet metal of a diameter slightly larger than the root diameter, only a narrow slit is formed in the dented sheet metal extending radially from the initial hole for a distance corresponding to the maximum radius of said threads to thereby provide a substantial anvil contacting surface against which the dented sheet metal can bear when the tool is pulled in an outwardly direction.
Claim 3
Dependent Claim
51 words
A dent straightening tool according to claim 1, wherein the maximum depth of said thread is at least three times the radius of the root, and the distance separating adjacent thread convolutions as measured longitudinally along the circumference of the root is at least one-half the pitch length of said thread.
Claim 4
Dependent Claim
33 words
A dent straightening tool according to claim 2, wherein said thread tapers from said root through the full depth of said thread to form a sharp edge at the crest of said thread.
Claim 5
Dependent Claim
16 words
A dent straightening tool according to claim 3, wherein said thread is formed from tempered steel.
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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) | 1983-11-04 | 1984-05-05 | 1984-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-04 | 1988-05-05 | 1988-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-04 | 1992-05-05 | 1992-11-04 | $7700.00 | Window Closed / Lapsed |