Abstract: A jarring tool uses a button member to control the jarring sequence used to free an object lodged in a well bore. A preferred tool includes an anvil having a sleeve portion adapted to enter a bore of a hammer. The button member allows selective entry of the anvil sleeve into the hammer bore. A preferred telemetry link includes two or more at least partially conductive members in a telescopic relationship for exchanging electrical signals with the object. The members extend and retract to accommodate length changes of the jarring tool. An exemplary jarring sequence includes a loading phase, a release phase, and a reset phase. In the loading phase, the button member prevents hammer movement toward the anvil. During the release phase, the button member allows the hammer to be propelled against the anvil. In the reset phase, the hammer and button returns to their initial positions.

Abstract: A jarring tool uses a button member to control the jarring sequence used to free an object lodged in a well bore. A preferred tool includes an anvil having a sleeve portion adapted to enter a bore of a hammer. The button member allows selective entry of the anvil sleeve into the hammer bore. A preferred telemetry link includes two or more at least partially conductive members in a telescopic relationship for exchanging electrical signals with the object. The members extend and retract to accommodate length changes of the jarring tool. An exemplary jarring sequence includes a loading phase, a release phase, and a reset phase. In the loading phase, the button member prevents hammer movement toward the anvil. During the release phase, the button member allows the hammer to be propelled against the anvil. In the reset phase, the hammer and button returns to their initial positions.