Abstract: A torsional spring 10 includes an outer cylinder 12 connected to a central hub 14 through a series of elastomeric spokes 16-30. The elastomeric spokes 16-30 extend from the inner periphery of the cylinder 12 to the hub 14 substantially along a line tangential to the central hub 14. Further, each of the elastomeric spokes 16-30 includes first and second radial segments wherein the first radial segment is adjacent the hub 14 and has an elastic modulus that is lower than the second radial segment.

Abstract: A number of riser tensioner systems which use passive energy storage devices, such as springs, are disclosed. The geometrical construction of these systems, along with the selection of proper spring rates for the individual springs, produces systems that have a total spring rate which varies in proportion to the stroke of the riser. Thus, the tensioning force exerted by the systems on the riser remains substantially constant throughout the range of motion of the riser.

Abstract: A flexible joint 13 is employed to sealingly connect a pair of tubular members 16, 18 while still permitting limited articulated movement therebetween. The flexible joint 13 includes a housing 26 with upper and lower ring-like plates 32, 34 coaxially arranged about the tubular members 16, 18. A pair of annular elastomeric bearings 40, 42 are positioned within the housing 26 and act against shoulders 44, 46 of the tubular members 16, 18 to flexibly retain the tubular members 16, 18 within the housing 26. A bellows 20 sealingly couples the tubular members 16, 18 together while permitting movement therebetween. An annular chamber 56 formed between the bellows 20 and housing 26 is filled with a fluid, such as silicon or oil. Means is provided for adjusting the volume of the chamber 56 or volume of fluid in the chamber 56 to maintain an approximately zero pressure differential across the bellows 20.

Abstract: A riser tensioner system 10 includes a pair of supports 14, 16 affixed to an offshore platform in spaced apart relation to one another. A shaft 24 extends between the supports 14, 16 and is pivotally coupled thereto by an elastomeric bearing 26. A central support 22 is pivotally coupled to the shaft 24 at about the midpoint between the supports 14, 16 and fixedly coupled to coil springs 30 or elastomeric springs 100 coaxially arranged about the shaft 24 and extending between the central support 22 and each of the supports 14, 16. The central support 22 is also coupled to a riser 12 so that relative movement between the offshore platform and the riser 12 causes the central support 22 to pivot on the shaft 24 and wind or unwind the coil springs 30 or elastomeric springs 100 for relative upward and downward movement thereof. A pretensioner mechanism 42 increases the force exerted by the springs 30 or elastomeric springs 100 to increase the upward force applied to the riser 12.

Abstract: A brake system for a drawworks includes a hydraulically actuated band brake system having a backup spring actuator for emergency stops. The system also includes a caliper disc brake system for emergency stops. The disc brake system includes a rotor directly mounted to the drum barrel and a pair of spring actuated caliper assemblies.

Abstract: Disclosed is a flooding system for uprighting and setting marine structures into and above bodies of water. The structures include a surface platform and at least one hollow support leg. Each leg includes at least one port that when closed will seal the leg. The system includes a valve attached to each port. The valve serves as a closure that regulates the flow of water from the body of water through the port to flood the structure. An operator is coupled to each valve by a low friction remote control cable. The operator is located above the surface of the body of water and usually attached to the platform. The cable translates the relative motion of the operator to open and close the valve. The cable comprises a flexible member encased in a flexible casing. The flexible member is isolated from the casing by a bearing means that allows the member to move axially within the casing to translate the motion of the operation to control the valve.

Abstract: An improved reinforcement cage assembly for use in the manufacture of a load lifting swab cup wherein the swab cup includes an elastomeric material bonded to the reinforcement cage assembly. The reinforcement cage assembly includes a metal base assembly and a plurality of axially disposed reinforcing wire members. In addition, an improved load lifting swab cup is disclosed having as an integral part thereof the improved reinforcement cage assembly.

Abstract: There is disclosed a compression loaded torsional coupling device for use in drive shafts to provide a resilient interface between input and output portions of the shaft. Elastomeric cushions between fins extending in alternating fashion from opposed coupling members provide the resiliency. The coupling is produced by a unique process. Elastomer is first inserted into alternating gaps between adjacent fins. This elastomer is then compressed by applying a torque to rotate the coupling members with respect to each other. Elastomer is then placed in the remaining gaps. The torque is then released, permitting the compressive forces to redistribute in the elastomeric material around the circumference of the coupling.

Abstract: This invention provides for an assembly of elements for conducting fluids where such fluids subject the interior of this assembly to a pressure greater than the pressure exerted on the exterior of the assembly by an ambient fluid. The assembly comprises a plurality of elements connected end-to-end by connecting means and at least one pair of such elements being connected by a flexible connector means. The flexible connector means includes a cylindrical housing that has a greater internal diameter than the external diameter of the elements that it is to connect, and is positioned such that these elements extend inwardly into said housing. A retainer means is employed at each end of the housing and it is adapted for retaining the elements in a fixed position relative to the housing and the flexible connector means.

Abstract: A closure for a chain entry aperture in which two or more seal blocks of a suitable elastomeric material are slidable between a position in which the aperture is open, and a position in which the seal blocks cooperate to close the aperture and seal around a chain extending through the aperture. Contact surfaces of the seal blocks are shaped to accommodate the chain passing through the aperture when the seal blocks are in the closed position.