| 摘要 |
<p>LONG STROKE JAR BUMPER SUB WITH SAFETY SLEEVE Patterned generally on the Downen Jar disclosed in U. S. Patent No. 2,989,132, the invention retains the ruggedness of its antecedent in enduring down spudding while expanding the range of jarring pressures endured from 40,000 pounds to 90,000 pounds. This radical improvement followed replacing the keyed spline with a hex spline section and excluding this from the hydraulic jarring control oil chamber and also locating the impact jar faces externally from said chamber, for lubrication entirely by ambient fluid, and transmitting the jarring up blow of the tool directly from the lower end of the external sleeve of the jar to the upper end of the male hexagonal spline sub. Opposed internal female splined sub and external short collar screwed into and onto said sleeve and sub, respectively, and readily replaceable, provide the juxtaposed jar impact faces, thus greatly strengthening the jar and simplifying its servicing. A separate metering sub heavily reinforces the midsection of the outer protective draft sleeve of the tool and protects the metering sleeve and its hydraulic chamber from damage, besides lessening machining costs. A safety sleeve supported by the metering sub through matching ground end faces retards "down bumper" movements when resetting the tool for a jarring operation to prevent these damaging the tool, due to spudding the tool. Docket K-3051</p> |
