Earth borer
Patent 6637521 Issued on October 28, 2003. Estimated Expiration Date: 
July 11, 2021. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.
July 11, 2021. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.Patent References 1657368 Core bit having axial conical core breaker Core drill and method of removing a core therefrom Hollow drill for fabric and the like Portable core sampler Coring bit and method for obtaining a material core sample Patent #: 6412575 InventorAssigneeApplicationNo. 09/902677 filed on 07/11/2001US Classes:175/19, BORING WITHOUT EARTH REMOVAL (I.E., COMPACTING EARTH FORMATION)175/320, WITH TOOL SHAFT DETAIL175/404, With core-breaking means408/204, Having axial, core-receiving central portion408/227Having peripherally spaced cutting edgesExaminersPrimary: Bagnell, DavidAssistant: Halford, Brian Attorney, Agent or FirmInternational ClassesE21B 17/046 (20060101)E21B 17/02 (20060101) E21B 11/00 (20060101) E21B 10/02 (20060101) E21B 10/00 (20060101) AbstractAn earth borer includes a thin-walled tubular shaft (4), a shank (2) provided at one end of the tubular shaft (4), and a drilling head (5) provided at another, opposite end of the tubular shaft, projecting radially beyond the tubular shaft (4), and having at least one cutter for breaking the bore core and (6, 6a, 6b, 6c, 6d) extending, at least partially, radially inward and at least one internal groove (7, 7a, 7b) associated with the at least one cutter, and a releasable tubular connection member (8) for drivingly connecting the shank (2) with tubular shaft (4) for joint rotation with each other. | |
