US3851560A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Self-drilling expansion roof bolt
Assignee: Individual
•
Filing: 1972-10-02
•
Granted: 1974-12-03
•
Expires: 1992-10-02
Abstract
Abstract A self-drilling expansion roof bolt having a drill rod with spaced ends. A cutting head provided with cutting edges is mounted on one end of the drill rod, and an end cap nut adapted for engaging in the drill head chuck of a roof bolting machine and the like is arranged at the other end. Rotation of the drill rod in a one direction will drill a hole in a mine roof and the like. The cutting head is circular in cross section and flared outwardly toward the cutting edges to form a wedge portion. An expansion shell in the form of a sleeve is arranged about the cutting head, and an arrangement including screw threads on the cutting head will cause engagement of the wedge portion with the expansion shell and expand the latter by a rotation of the drill rod in the reverse direction to that for drilling the hole. The expansion will anchor the cutting head and drill rod in the hole.
Inventors
- 👤 J Yago
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 00:51
CPC Classifications
F; F16; F16B; F16B13/00; F16B13/002; F16B13/004
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
173 words
A self-drilling expansion roof bolt, comprising, in combination: a. a member; b. means mounted on the member for making a hole; and c. means for anchoring the member in a hole, the hole making means making a hole when the member is rotated about an axis of rotation in a one direction, and the anchoring means anchoring the member in a hole when the member is rotated about the axis of rotation in a reverse direction to the one direction, the anchoring means including an expansion shell, a wedge portion arranged for selective engagement with the expansion shell, and means for engaging the wedge portion with the expansion shell and expanding the latter by a rotation of the member in the reverse direction, tHe engaging means including external screw threads, and a drive nut having internal screw threads threadingly engaged with the external screw threads and jaw elements provided on an outer periphery of the nut for engaging only in the reverse direction of rotation of the member with walls defining the hole.
Claim 2
Dependent Claim
173 words
A self-drilling expansion roof bolt, comprising, in combination: a. a member; b. means mounted on the member for making a hole; and c. means for anchoring the member in a hole, the hole making means making a hole when the member is rotated about an axis of rotation in a one direction, and the anchoring means anchoring the member in a hole when the member is rotated about the axis of rotation in a reverse direction to the one direction, the anchoring means including an expansion shell, a wedge portion arranged for selective engagement with the expansion shell, and means for engaging the wedge portion with the expansion shell and expanding the latter by a rotation of the member in the reverse direction, tHe engaging means including external screw threads, and a drive nut having internal screw threads threadingly engaged with the external screw threads and jaw elements provided on an outer periphery of the nut for engaging only in the reverse direction of rotation of the member with walls defining the hole.
Claim 3
Dependent Claim
25 words
A structure as defined in claim 1, wherein the hole making means includes a cutting head provided with cutting edges arranged for drilling a hole.
Claim 4
Dependent Claim
21 words
A structure as defined in claim 2, wherein the wedge portion and external screw threads are arranged on the cutting head.
Claim 5
Dependent Claim
46 words
A structure as defined in claim 3, wherein the cutting head is circular in cross section and flared outwardly toward the cutting edges to form the wedge portion, and the expansion shell is a sleeve provided with slots and projections and arranged about the cutting head.
Claim 6
Dependent Claim
20 words
A structure as defined in claim 4, wherein the member further includes means for attaching the member to a chuck.
Claim 7
Dependent Claim
61 words
A structure as defined in claim 5, wherein the member is a longitudinal drill rod and has spaced ends, with the cutting head arranged at one end and the attaching means at the other end, and a bore provided through the cutting head and drill rod for forming a removal passageway for particulate matter produced by the making of a hole.
Claim 8
Dependent Claim
20 words
A structure as defined in claim 2, wherein the member further includes means for attaching the member to a chuck.
Claim 9
Dependent Claim
61 words
A structure as defined in claim 7, wherein the member is a longitudinal drill rod and has spaced ends, with the cutting head arranged at one end and the attaching means at the other end, and a bore provided through the cutting head and drill rod for forming a removal passageway for particulate matter produced by the making of a hole.
Claim 10
Dependent Claim
58 words
A structure as defined in claim 2, wherein the cutting head is circular in cross section and flared outwardly toward the cutting edges to form a wedge portion, and the anchoring means includes an expansion shell in the form of a sleeve provided with projections and arranged about the cutting head for being expanded by the wedge portion.
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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) | 1977-12-02 | 1978-06-03 | 1978-12-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-02 | 1982-06-03 | 1982-12-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-02 | 1986-06-03 | 1986-12-03 | $7700.00 | Window Closed / Lapsed |