US3854840A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Core drill
Assignee: Individual
•
Filing: 1974-02-15
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Granted: 1974-12-17
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Expires: 1994-02-15
Abstract
Abstract A core drill has a fixed disk and a movable disk within the drilling cylinder. Both disks are tapered at their periphery and a tension ring is placed around the peripheries. The drilling cylinder is driven through the ring and the disks. A center drill is provided in the drilling cylinder for centering prior to the drilling with said cylinder.
Inventors
- 👤 M Miyanaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 19:26
CPC Classifications
B; B23; B23B; B23B31/00; B23B31/02; B23B31/10; B23B31/11; B23B51/00; B23B51/04; B23B51/0473; E; E21; E21B; E21B10/00; E21B10/02; E21B10/26; E21B10/62; Y; Y10; Y10T; Y10T408/00; Y10T408/89; Y10T408/895; Y10T408/896; Y10T408/8967
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
109 words
A core drill comprising a shank having a drill receiving recess in the lower end thereof, a shoulder thereon and a threaded portion between said shoulder and said lower end, a fixed disk around said shank between said shoulder and said threaded portion and against said shoulder, a movable disk threaded on said threaded portion, said disks having tapered edge portions on the peripheral edges thereof which taper toward each other, a split ring having a cross-section with tapered edges engaging said tapered edge portions, and a drilling cylinder around said ring with the inside surface of the drilling cylinder closely fitted to the outer surface of said ring.
Claim 2
Dependent Claim
109 words
A core drill comprising a shank having a drill receiving recess in the lower end thereof, a shoulder thereon and a threaded portion between said shoulder and said lower end, a fixed disk around said shank between said shoulder and said threaded portion and against said shoulder, a movable disk threaded on said threaded portion, said disks having tapered edge portions on the peripheral edges thereof which taper toward each other, a split ring having a cross-section with tapered edges engaging said tapered edge portions, and a drilling cylinder around said ring with the inside surface of the drilling cylinder closely fitted to the outer surface of said ring.
Claim 3
Dependent Claim
33 words
A corE drill as claimed in claim 1 in which said fixed disk has a flange extending radially outwardly from the peripheral edge thereof against which the end of the drilling cylinder abuts.
Claim 4
Dependent Claim
56 words
A core drill as claimed in claim 1 in which said fixed disk has a collar thereon around said shank and abutting said shoulder and a recess in the face thereof toward said movable disk and around said shank, and said movable disk has a collar thereon around said shank which is movable in said recess.
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) | 1977-12-16 | 1978-06-17 | 1978-12-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-16 | 1982-06-17 | 1982-12-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-16 | 1986-06-17 | 1986-12-17 | $7700.00 | Window Closed / Lapsed |