Patent US2703770A successfully refreshed from Google Patents.
US4078458A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Screw extractor
Assignee: BERENDZEN RAY
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Filing: 1976-10-13
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Granted: 1978-03-14
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Expires: 1996-10-13
Abstract
Abstract A screw extractor utilizes a twist drill affixed to one end of an extractor bit having a shank portion suitable for grasping by the chuck end of an electric drill. In use, the drill causes a hole to be formed along the length of the body of the screw to be extracted. Continued rotation in a selected direction of the assembly causes the extractor bit to grasp the walls of the hole. The screw is easily removed without requiring the user to first drill a hole and then manually remove the screw utilizing a separate extractor bit.
Inventors
- 👤 Ray Berendzen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 14:22
CPC Classifications
B; B23; B23B; B23B51/00; B23B51/08; B25; B25B; B25B27/00; B25B27/14; B25B27/18; Y; Y10; Y10T; Y10T29/00; Y10T29/53; Y10T29/53687; Y10T408/00; Y10T408/89; Y10T408/909; Y10T408/9095; Y10T408/9097
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
180 words
A screw extractor comprising a rod, a twist drill having metal cutting surfaces disposed at one end thereof, the twist drill having at least one spirally wound flute extending from the metal cutting surfaces, said flute having the external portion of the exterior surfaces thereof defining a cylindrical surface, said cylindrical surface being parallel to the longitudinal axis of said twist drill, an elongated rod having a truncated conical exterior surface co-axially aligned with the longitudinal axis thereof, said conical exterior surface having at least one spirally wound groove disposed extending longitudinally from the apex of said conical exterior surface, said groove forming work engaging ribs extending in a continuous spiral path along said conical exterior surface, the other end of the twist drill being disposed fixedly secured to said apex of said conical exterior surface, one end of said rod being disposed fixedly secured to the base of said conical exterior surface, said longitudinal axis of said elongated rod and said longitudinal axis of said twist drill and the longitudinal axis of said rod being disposed in coaxial alignment.
Claim 2
Dependent Claim
180 words
A screw extractor comprising a rod, a twist drill having metal cutting surfaces disposed at one end thereof, the twist drill having at least one spirally wound flute extending from the metal cutting surfaces, said flute having the external portion of the exterior surfaces thereof defining a cylindrical surface, said cylindrical surface being parallel to the longitudinal axis of said twist drill, an elongated rod having a truncated conical exterior surface co-axially aligned with the longitudinal axis thereof, said conical exterior surface having at least one spirally wound groove disposed extending longitudinally from the apex of said conical exterior surface, said groove forming work engaging ribs extending in a continuous spiral path along said conical exterior surface, the other end of the twist drill being disposed fixedly secured to said apex of said conical exterior surface, one end of said rod being disposed fixedly secured to the base of said conical exterior surface, said longitudinal axis of said elongated rod and said longitudinal axis of said twist drill and the longitudinal axis of said rod being disposed in coaxial alignment.
Claim 3
Dependent Claim
27 words
The screw extractor as claimed in claim 1 wherein the direction of twist of said flute is the same as the direction of twist of said groove.
Claim 4
Dependent Claim
26 words
The screw extractor as claimed in claim 1 wherein the direction of twist of said flute is opposed to the direction of twist of said groove.
Claim 5
Dependent Claim
44 words
The screw extractor as claimed in claim 1 further comprising at least one elongated groove being disposed in said conical exterior surface of said elongated rod, the elongated groove being disposed residing in a plane passing through said longitudinal axis of said elongated rod.
Claim 6
Dependent Claim
30 words
The screw extractor as claimed in claim 1 wherein the outside diameter of said twist drill is substantially equal to the diameter of said conical exterior surface at said apex.
Claim 7
Dependent Claim
29 words
The screw extractor as claimed in claim 1 wherein the outside diameter of said rod is substantially equal of the diameter of said conical exterior surface at said base.
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) | 1981-03-13 | 1981-09-12 | 1982-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-03-13 | 1985-09-12 | 1986-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-03-13 | 1989-09-12 | 1990-03-14 | $7700.00 | Window Closed / Lapsed |