Abstract: A measuring device includes a generally tubular, flexible body with opposite ends and a longitudinally-extending bore. The body includes a plurality of measuring indicia at regularly-spaced intervals therealong. It can be selectively mounted on the body ends and have a predetermined length which corresponds to the measuring indicia spacing. An extension connector is also provided for connecting two measuring device bodies together. A centering assembly has a sleeve which receives the body and wings projecting radially outwardly therefrom for generally centering the measuring device within a pipe bore.

Abstract: A free fall stroker for raising and dropping a drop hammer for soils bearing testing or the like includes a housing through which a drop hammer cable extends from one side to the bottom thereof. A pair of guide pulleys guide the cable through the housing and a movable sheave operates within a parallelogram-shaped track with four legs, and is attached to a telescoping arm of a hydraulic stroking cylinder. When the arm is retracted, the sheave is moved in a first leg of the track and engages the cable, pulling it between the guide pulleys. When the sheave reaches the end of the first leg, it moves in a second leg in a second direction away from the guide pulleys. This causes the cable to be released, thus dropping the drop hammer and letting it free fall. Extension of the telescoping arm then returns the sheave to the point of origin via the third and fourth legs of the track. A winch is provided on top of the housing to adjust the cable length and a stroke counter counts the number of hammer strokes.

Abstract: A chuck apparatus including a plurality of radially movable jaws for gripping a drill rod, each jaw being moved radially by an axially movable bowl, each jaw and the corresponding bowl surfaces are provided with two sets of camming surfaces, the first set of camming surface being oriented with a steeper angle than the second set of camming surfaces. In operation, as the bowl moves relative to the jaws with the respective first set of camming surfaces of the jaws and the bowl in contact, the jaw gripping force is relaxed and the jaws release the drill rod. As the bowl and jaws continue to move they transition to interact at their respective second set of camming surfaces whereupon, because the shallow angle of interface, the jaws are moved through a greater distance than if the first set of camming surfaces' steeper angle of interface were employed. As a result, more clearance is provided for freeing the drill rod.