Core drill and method of removing a core therefrom
Patent 4657445 Issued on April 14, 1987. Estimated Expiration Date: 
April 14, 2004. 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.
April 14, 2004. 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 ReferencesInventorApplicationNo. 06/588230 filed on 03/12/1984US Classes:408/1R, PROCESSES175/404, With core-breaking means175/405.1, Includes diamond175/58, Sampling of earth formations279/20, Fluid-conduit drill holding408/207, Having product-receiving chamber408/239R, With tool-retaining means408/68EjectorExaminersPrimary: Weidenfeld, GilAssistant: Webb, Glenn L. Attorney, Agent or FirmInternational ClassesB23B 31/11 (20060101)B23B 31/10 (20060101) E21B 17/042 (20060101) E21B 25/00 (20060101) E21B 17/02 (20060101) AbstractDisclosed is an improved core drill and a method of detachably coupling the same to a power driving unit to expedite the removal of a core therefrom. This is achieved by equipping the rear end of the drill stem with a fixedly attached externally threaded bushing. A coupling sleeve has internal threads at either end matable respectively with the bushing threads and the threaded drive shank of a power driving unit. This sleeve and the core drill are readily detached as a unit from the power drive thereby permitting the rapid removal of the core from the rear end of the drill rather than past the cutting ring at its front end. | |
