Core Lifter Assembly
AssigneeCT Tech Pty Ltd
InventorShayne Beach
Life of this patent
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Abstract
A core lifter assembly includes a combination of a core lifter ring and a core lifter case. The ring has an axially extending portion of an outer generally frusto-conical configuration having an included taper angle β. The included taper angle β is also the taper angle of the outer circumferential surface of the ring. The included taper angle β may in alternate embodiments be ≧6°; ≧7°; ≧8°; or ≧10°. In one embodiment an upper limit of the included taper angle β may be about 30°. Thus in one embodiment the included taper angle β may be expressed by the relationship: 30°≧β≧6°. Further, the angle β may comprise any sub range within the aforementioned range of 6-30°. However in other embodiments the taper angle may exceed 30°.
Claims21
1-39. (canceled)
A core lifter for a core drill comprising:
- at least one core lifter ring having at least one axially extending portion having an outer generally frusto-conical configuration formed with an included taper angle β≧6°.
A core lifter for a core drill comprising a core lifter ring having opposite downhole and uphole ends spaced by an axial distance X, an interior circumferential surface having a substantially constant major diameter for the axial distance X, and an outer circumferential surface, wherein the interior circumferential surface and outer circumferential surface are configured to form a half angle θ≧3° for at least a portion of the distance X in at least two circumferentially spaced locations and wherein at the locations a wall of the ring decreases in thickness in a direction from the uphole end to the downhole end.
A core lifter for a core drill comprising a core lifter ring having opposite downhole and uphole ends spaced by an axial distance X, an interior circumferential surface having a substantially constant major diameter for the axial distance X, and an outer circumferential surface, wherein the interior circumferential surface and outer circumferential surface are configured to provide the ring with a half angle θ≧3° for at least a portion of the distance X wherein a wall of the ring decreases in thickness in a direction from the uphole end to the downhole end for the corresponding portion of the distance X.
Dependencies are inferred from the claim text.