Abstract: Load indicating apparatus in which a hydraulic load sensing unit is pivotally connected by coupling pins respectively with opposed members capable of relative movements under applied load forces, one of the coupling pins comprising an electronic load sensing unit in the form of a hollow pivot pin structure with internally mounted electrically interconnected strain gages operative in response to the applied load forces to generate an output signal.

Abstract: A unique variable cable hoisting system utilizing a deadline load indicating apparatus in which the end terminus of the deadline is releasably anchored to a snubbing drum of the load indicating apparatus by quickly releasable hinge members which serve to restrain the end terminus against lateral movements and also to provide an abutment for engaging an abutment on the cable end terminus for opposing its axial movement under load forces and anchoring it to the snubbing drum of the deadline load indicating apparatus, when the cable system is being operatively utilized as a single fastline system. The quickly releasable feature concept, however, permits the terminus end of the deadline to be quickly detached from the snubbing drum and attached to a main hoisting drum as a second fastline to provide a double fastline hoisting system having the capability of doubling the hoisting speed.

Abstract: A load sensing device for connection in load indicating apparatus between a pair of spaced members arranged to move apart under applied load tension forces, the load sensing device having a hydraulic load cell and an electronic load cell mechanically mounted in stacked series relationship and being respectively connected with a load indicator, wherein the applied tension load forces of the apparatus are mechanically converted into compression load forces for the actuation of the load cells. Manual selectors are also provided to permit the selective use of one or the other of the load cells as the sensing medium to energize its associated load indicator, and which includes a split ring for selectively by-passing the load forces with respect to the hydraulic load cell when utilizing the electronic load cell.

Abstract: A load sensing unit for load indicating apparatus, the sensing unit comprising a hydraulic load cell and an electronic load cell connected in stacked relation between opposed members of the apparatus capable of relative movements under applied load forces, and wherein means are provided to operably selectively bypass the load forces with respect to each of said load cells, in order to operatively inactivate one of the load cells, and hold it in reserve as a back-up cell which is susceptible of immediate connection for the active operative other load cell.

Abstract: The following specification discloses an anchor for a cable employed in rotary drilling rigs for oil well derricks. Tension on the anchored cable is measured through a load cell in connected relationship to the anchor. The anchor comprises a drum upon which the cable is wound and snubbed, and is journaled for partial rotative connection around a spindle on a base member. The drum is fabricated from weldments in a unique manner and employs a weigh beam that is triangularly braced to incorporate maximum strength to the welded drum to which it is attached. In addition thereto, the weigh beam is oriented for optimization of the transfer of rotative tension forces on the drum to the weigh beam and then to the load cell in a manner whereby the movement of the weigh beam describes a substantially uniform movement through its operative functions.