Abstract: An output gear is on an elongate sheath capable of withstanding torsion between its ends. The sheath is equipped with a device for measuring the torque borne by the gear. The device for measuring the torque comprises a bar which extends through the sheath, fixed to the sheath at one end and equipped at the other end with a lever in contact with at least one linear displacement sensor, preferably of the inductive coupling type. The sensor can supply data to a central unit for collecting all data gathered from each output gear. The central unit comprises a computer for determining a mean torque value, and optionally, the weight of the platform to be established, and a controller for automatically controlling the plurality of maneuvering mechanisms.

Abstract: A system and method are provided to facilitate disengagement of two mechanisms engaged with one another with a high stress therebetween, such as in rack locking arrangements used on offshore platforms. The first mechanism (e.g., a rack) is mobile in relation to the second mechanism (e.g., a pair of locking jaws) which serves as a locking mechanism for the first mechanism. The level of stress between the first and second mechanisms is measured, and the measurement is converted into an electrical control signal. This signal is used to control motor-driven force applying elements (e.g., pinions) in engagement with the first mechanism. The force applying elements are controlled in such a manner as to apply force to the first mechanism sufficient to offset the aforementioned stress between the first and second mechanisms, thereby permitting friction-free disengagement of the mechanisms.

Abstract: An automatic gripper, useful especially for gripping and holding drilling rods on a drilling rig, has a chassis with a front end in the form of a fork equipped with retractable jaws (50). The jaws are retracted by pushing contact with a drilling rod (40) when the rod enters the fork, whereupon a return mechanism (72) automatically restores the jaws to a closed position. The chassis is held fixed on a horizontal pivot axis by rupturable pins or the like. The pins rupture to permit the chassis to pivot when subjected to a predetermined torque, with friction members being provided to frictionally limit the pivotal movement of the chassis. The gripper is thus protected against damage from impacts with the rod lifting mechanism of the drilling rig, for example.

Abstract: The invention concerns a process and an installation for vertical racking of drill shafts on a drilling tower. The installation comprises mechanisms (34, 36, 38, 40) to grasp an upper intermediate portion of an assembly (26) of shaft sections removed from the well bore, and to incline this shaft assembly with respect to vertical below lifting mechanisms (16, 18). The installation further includes mechanisms (42, 44, 46, 48, 50) to receive and support the lower end of the shaft assembly and then displace the assembly in synchronization with the first mentioned mechanisms to transport the assembly to racks for vertical storage.

Abstract: A machine applies screwing and unscrewing torque between successive drill pipes with an essentially vertical axis extending through a tapered opening in a turntable for a well bore. The machine includes a mechanism for applying a high initial unthreading torque and a high final threading torque between successive drill pipes and a mechanism for rapid screwing and unscrewing of successive drill pipes. The machine also includes a clamping mechanism having a bolster and a plurality of shims. The shims have outer portions tapered to fit into the opening of the turntable and have inner portions with a shape corresponding to the shape of the drill pipes. Each shim is supported individually on the bolster by a device that moves the shim into engagement with a drill pipe to grip the same and with sufficient freedom to permit the shims to center the pipe between them automatically. The bolster is lowered to cause the shims to enter the opening in the turntable.

Abstract: Apparatus and method for the locking and releasing of a train of drilling shafts having an essentially vertical axis employ wedges adapted to penetrate an opening in a rotation table of a wellhole in order to lock upon a shaft projecting from the opening while another shaft is screwed to or unscrewed from the upper end of the first-mentioned shaft. The wedges have a tapered external shape complementary to the shape of the opening and an internal shape complementary to the external shape of the shafts. Each wedge is individually attached to an associated arm connected to a vertically movable plate by means of an articulation and a jack that applies the wedge to a shaft. The attachment of the wedges to the arms has sufficient freedom to permit the wedges to engage a shaft and center the shaft between the wedges automatically before the wedges are lowered into the opening of the rotation table to lock the engaged shaft therebetween.

Abstract: A machine to apply screwing and unscrewing torque to successive drilling shafts employs upper and lower claws, one of which is fixed and the other of which rotates through a limited angular range. Each claw comprises a pair of right-angle branches extending oppositely from a base and terminating in spaced relation to provide a permanent opening at one side of the claw opposite to the base. Each claw has a jaw comprising three gripping elements positioned essentially at the vertices of an equilateral triangle, one gripping element being fixed to the base and the other gripping elements being movably mounted on the branches at opposite sides of the opening. One claw comprises a pair of parts relatively movable vertically to form a viewing opening when the machine is not applying torque.

Abstract: The arrangement to which the invention pertains consists of a combination of calibrated compressible components (15), such as washers arranged in stacks, situated between an element (13) secured to the platform and another element (11) secured to a mounting which provides support for jacking mechanisms, accompanied by a sensor device (24) positioned according to the same conditions. The movable core (25) for the aforementioned sensor (24) is attached to a sliding element (21), which, in turn, is attached to the element identified as (13). Under these circumstances, the movable core (25), according to the positions which it may occupy, can modify connections for windings within the sensor. Data obtained in this manner is transmitted by a cable (28) to recording devices, as well as to direct reading devices or to indicators. Application for ocean platforms, notably for offshore drilling platforms.

Abstract: The present invention pertains to self-raising ocean platforms which possess multiple legs and multiple jacking mechanisms of the double rack and pinion type with opposite sets of teeth. In accordance with the invention, each double rack 4 contains sets of obliquely cut teeth, with at least one rigid component constituting a lateral thrust-block 7 being situated between the platform structure 2 and each platform leg 1, in such a manner that this arrangement provides force, c, which tends to press one portion of the platform leg 1 against the thrust-block 7, thereby ensuring constant positioning of the pinion teeth 5 in relation to the set of teeth located upon the rack 4.

Abstract: The present invention applies to those auto-elevating marine platforms, as for deep-sea drilling and the like, outfitted with a number of legs and a number of associated jacking mechanisms of the rack and pinion type set with the rack's teeth in opposition, wherein a flexible coupling (5), the axis of compression of which is inclined, is placed between the support-framework (2), where the pinions (3) are mounted, and the main structure (1) of the platform in such a way that a relative freedom of movement between the support-framework (2) and the structure (1) is permitted. The intention is that the axis of compression of the flexible coupling (5) passes substantially directly through the instantaneous center of rotation of the upper part of the leg.

Abstract: This level detector comprises a tubular body closed at each of its ends and displaying a planar or slightly concave roller track, a ball suited to roll on the said roller track toward one or the other of the said closed ends of the body as a function of the inclination of the detector to the horizontal, and two receptors to detect the presence of the ball respectively at one and the other of the said ends and to emit a signal in response to this detection. This level detector can be installed on a grabbing apparatus in order to remember and preserve during hoisting the initial attitude of a load seized by the grabbing apparatus.