Abstract: A telescoping workover rig is characterized by a derrick having a bottom mast section mounted on a base or carrier and a top mast section telescopically fitted in the bottom mast section. In functional configuration a system of tram sheaves mounted on movable trams and connected to opposite fixed stationary sheaves by a continuous cable, serve to raise and lower a travelling block suspended by the cable from travelling block sheaves and crown sheaves in the extended top mast section. The trams that mount the tram sheaves are fitted to the ends of one or a pair of cylinder rods extending from a corresponding tram drive cylinder or cylinders.

Abstract: A line tensioning system for regulating tension on a line having a proximal end and a distal end, where the proximal end is operatively connected to a drum. The line tensioning system comprises a frame, a first and second sets of rollers, and first and second sets of displacement assemblies. The frame defines first and second side edges. Each first and second displacement assembly is arranged to displace at least one of the first and second rollers relative to the first and second side edges of the frame, respectively. The line is arranged such that the line contacts the first and second rollers. The first and second displacement assemblies displace the first and second rollers relative to the first and second edges based on a tension on the line.

Abstract: A retractable load support system for effectively lifting a load in a controlled manner. The retractable load support system includes a frame, a gerotor attached to a main shaft within said frame, a first spool attached to the gerotor, a biasing device connected to the first spool applying a biasing force to the first spool and an elongated member attached to the first spool. The main shaft is rotatably supported within the frame by a one way bearing allowing the main shaft to rotate when the elongated member is drawn downwardly to reduce the resistance of the gerotor. The main shaft is supported substantially stationary within the frame by the one way bearing preventing the main shaft from rotating when the elongated member is drawn upwardly onto the first spool thereby lifting the load in a controlled manner.

Abstract: A method of damping the oscillations during an emergency stop of an ascending single drum hoist system in a shaft having a conveyance, the mechanical brakes applying a braking force to the drum and the drum rotating in a first direction having a speed, comprising applying a first brake force when the drum speed reaches close to zero enabling the drum to roll back in an opposite direction to the first direction by a force generated from a first conveyance downward swing, and controlling the brake force during the first conveyance downward swing to dissipate the energy of the swing.

Abstract: A system or apparatus and method for retrieving cable from water during marine operations is provided that reduces damage to the cable from pulling forces during the retrieval. A pulling device distributes the forces and stresses all along the cable components. In one embodiment, the pulling drive comprises a pulling drum powered by a clutching system or by a hydraulic torque conversion system set to slip or stall at a selectable force value. The apparatus may use a see-saw action to maintain the forces below damaging levels. The system may be adapted for deploying cable in marine operations as well.

Abstract: The invention is a hoist system for use on a drilling rig made of a tubular mast with a front, back, and top side, a splittable block connected to the mast top side, a trolley with a trolley top and bottom side, wherein the trolley's top side is connected to the splittable block and wherein the trolley is removably secured on the mast's front side, a gripper connected to the trolley bottom side for gripping a load, a hoist cable passing through the splittable block and connected on one end to a hoist cable winch, and a hoist cable winch adapted to pull the hoist cable over the mast top side and through the splittable block to move the trolley relative to the tubular mast and lift the load.

Abstract: The invention is a hoisting device for a vessel a base structure provided with fixed cable blocks with pulleys; a trolley connected to a cable pulley block and a mechanism for gripping a load; a compensator a hoisting mechanism with a hoisting cable and a winch, wherein the hoisting cable is guided over the cable pulleys connected to the base structure and is adapted to move the trolley relative to the base structure with the aid of the winch; a secondary compensator with fixed cable blocks and pulleys connected to the base; a cable pulley set connected to the compensator end; a connection cable connected to a stationary section and a movable cable block with pulleys; a hoist connected to the vessel; a connecting cable guided over pulleys; and movable cable block and is adapted to move the compensator second end with the aid of the secondary hoisting mechanism.

Abstract: Apparatus comprising a tensing element connected at one end thereof to a supporting structure and at another end thereof to a cover, wherein movement of the cover imparts a force on the tensing element, an actuator adapted to move the tensing element, and a sensing device adapted to sense an equilibrium force position of the tensing element, wherein if the force changes the equilibrium force position the sensing device instructs the actuator to change a tension imparted by the tensing element on the cover.

Abstract: A load compensator is disclosed for use in connection with a pipe running tool. The load compensator includes an outer housing connected to the portion of the pipe running tool that holds the pipe segment. A piston is disposed within the housing, and is connected to a top drive system of the pipe running tool. The housing is formed with a first port through which pressurized air is delivered inside the housing to drive the piston within the housing. A second port is disposed at a selected location on the housing, such that when the piston is advanced past the second port, pressurized air passes through the port, and causes the control circuit to stop delivering air through the first port. Once pressurized air no longer flows through the second port, the control circuit causes air to be delivered to the first port.

Abstract: The invention is a hoisting device for a vessel with a mast in the form of a tube or sleeve with fixed cable blocks on the top side, a trolley with moveable pulleys, a feature on the bottom side for gripping a load, a hoisting system with at least a hoisting cable and a winch, wherein the hoisting cable is guided over the cable blocks and pulleys of both the mast and the trolley in order to move the trolley relative to the mast with the aid of the hoisting system, and a compensator located in the mast in the form of a pneumatic or hydraulic cylinder for damping movements of the vessel as a result of heave and beating of the waves characterized in that the hoisting cable is guided over cable pulleys that are connected to the ends of the compensator.

Abstract: A chain hoist, includes a chain which is trained over first and second sprockets defining a movement path for the chain, with the first sprocket being connected to a load-bearing member, and with the second sprocket being part of a drive unit for operating the chain. In order to effectively prevent chain vibrations caused by the so-called polygon effect, the chain hoist includes a damping unit which is positioned in the movement path of the chain for damping vibration.

Abstract: A method and apparatus for regulating a load compensator device for a handling gear. The load compensation device includes: a stationary internal bell housing; a mobile external bell housing which is secured at one of the ends of a handling member, from the other end of which the load is hung; and an overload pneumatic cylinder and an underload pneumatic cylinder connected to a pressure source and/or exhausted by a series of electric directional control valves. The pressure is controlled within the cylinders continuously to alter the datum position of the external bell housing that corresponds to the state of equilibrium, function of the variations in pressure which are measured at the cylinders. Changes in pressure cancels out any overload or underload effect on the load and returns the load compensator to its state of equilibrium that corresponds to the handling gear in its initial state of equilibrium.

Abstract: A hydraulic drag fly reel for creating drag resistance on fishing line when playing a hooked fish to prevent backlash, wherein the hydraulic drag fly reel comprises a crank plate, a fishing line storage spool connected or mounted to the crank plate by way of a hub extending from the interior of the crank plate, a crank handle connected to the outside of the crank plate for rotating the spool, and a hydraulic drag system including an oil chamber, a turbine disposed in the oil chamber and a gearing system for rotating the turbine within the chamber when releasing line so as to automatically create drag on the fishing line in proportion to the resistance of the fluid in the chamber. The resistive drag automatically adjust in proportion to the force exerted by the hooked fish, especially with accelerated movements.

Abstract: A device (1) for equalizing the weight of a suspended load, for example a tool to be operated by hand, includes a cable drum (2) and at least two parallel or substantially parallel suspension cables (3), which can be evenly wound up and unwound on a corresponding number of grooves (9) of matching diameter arranged parallel alongside one another on the cable drum (2). Each of the suspension cables (3) has for this purpose a resistance to tear corresponding to or exceeding the nominal load to be accommodated, so that considerably larger safety reserves are present, and even if one cable tears, the remaining cable can continue to carry the load. By distributing the load on two cables, the danger of a cable tear is, however, at the same time diminished.

Abstract: A cable foul sensor device for winches includes a flapper plate extending from a cover for the cable drum, and a sensing finger extending along the edge of the flapper plate to terminate above an upper layer of cable wound on the drum. The flapper plate is connected to a pivot member through which an adjustable set screw is mounted. A stationary housing for spring loaded switches is mounted on the cover and includes a contact plate which is depressed downward by the set screw of the pivot member to force the switches to the closed position to provide power for the drum. Upon fouling of the cable at the drum, the cable foul will displace the sensing finger and the flapper plate which will cause the pivot member to pivot away from the actuator plate, thereby permitting the spring loaded switches to bias in the open position to interrupt power to and lock the drum. An audio and/or visual signal is provided to indicate that a cable foul at the drum has occurred.

Abstract: A heave compensator for a drill ship with a derrick and hoist system with a dead line provides a line reservoir on the dead line. The dead line is reciprocated to move the hook load relative to the vessel to control it relative to the sea bed. The line reservoir is expanded or contracted by changes in ballast pressure to counterbalance the hook load. To compensate for heave and friction in the hoist system a pressure source is provided to augment the ballast pressure for hook load and position control. Sensors and controls are provided to anticipate and compensate for oncoming heave excursions. The dead line being flexible permits latitude in selecting and orienting the compensator machinery. As an option, the vertical movement sensor is placed on the hook related structure for more responsiveness to hook load movements.

Abstract: A method and device for withdrawing an element fastened to a mobile installation from the influence of the movements of this installation. The device comprises at least one actuating cylinder, at least one accumulator and several pulleys, are determined so that the mechanical and hydro-pneumatic forces are substantially equal.

Abstract: A hoist for loads that includes an elongated upright support assembly and an elongated extending support assembly pivotally mounted to the upper end of the former. The free end of the elongated radially extending assembly being able to follow a curved path in a horizontal plane. An elastic cable is attached to a non-elastic cable that is wound in a spool assembly so that the equilibrium point for the tool or equipment load can be adjusted at a vertical point. The spool is driven by an electric motor that in turn is activated by the wireless transmission of signals for winding and unwinding. These signals are produced when the tension at the end of the elastic cable attached to the load falls outside a predetermined range.

Abstract: A lifting appliance, especially for a patient lifting device, comprises a telescopic column (10) having a carriage (22) which is reciprocable in the longitudinal direction of the column under the action of the telescopic extension and retraction motions of the column. The appliance comprises safety means (37) which are adapted to stop the telescopic motions of the column, in case of defects in the power transmission between a driving motor (15) producing the telescopic motions of the column, and the carriage (22), or if the carriage (22) or a lifting means connected therewith should be stopped by some object in its downward motion.

Abstract: A motion compensation and tension control system (MCATS) for a surface vessel overboarding, umbilical cable supported, submersible payload is provided with a housing containing a pair of spaced parallel guide rods attached to oppositely disposed housing end plates. Two identical carriages, slidably disposed on the pair of guide rods, each include two parallel slide tubes rigidly attached by a cross plate and by an axle, with a plurality of sheaves rotatably supported by each axle. Motion of each carriage as a rigid body along the guide rods is elastically restrained by, either extension or compression springs. The surface vessel umbilical cable is received through an opening in one of the end plates, reeved around the two sets of sheaves, and mechanically connected to the other end plate. Wave induced surface vessel motion is transmitted through the umbilical cable and absorbed, or compensated for, by the spring restrained carriage motion before it reaches the submersible payload.

Abstract: A system which limits the intensity of a snap load imposed in a tether or cable, used, for example, in the recovery of an object at sea, includes a floating plate for connection to the cable and a support housing for connection to the object being recovered. The system also includes an actuatable mechanism extending between and connected to the plate and housing. The actuatable mechanism is movable from an initial position toward a deflected position in response to the introduction of a snap load in the cable caused by the occurrence of the sudden removal of a slack condition in the cable.

Abstract: The present invention is an improved platform-mounted apparatus for holding and rapidly releasing a flexible load line having the properties of a wire rope. The invention comprises wedge gripper means for holding the line up to a tensile force substantially equal to the breaking strength of the line, with the gripper means comprising a grip frame for mounting to the platform and a pair of opposed grip wedges, the wedges having opposed internal gripping surfaces for engaging the line and external wedging surfaces that taper toward each other in the direction of the tensile force in a gripped line, each grip wedge having a wide end and a narrow end. Grip connection means connect the wide end of each grip wedge to the grip frame, said grip connection means defining a lower travel limit for each grip wedge in the direction of the tensile force in a gripped line.

Abstract: A method and apparatus for increasing the load handling capacity of a system, having at least one fluid driven compensating means, incorporates a booster fluid actuated piston cylinder assembly interconnecting portions of the compensating system so as to substantially affect the force reacting characteristics thereof, whereby greater loads will produce lesser movement of the compensating means.

Abstract: A novel rope tension damper device is adapted to be installed, for example, on the deck of a ship at a location between the winch that controls the effective length of the rope and the fairlead that guides the rope so that it does not snag or tangle as it is wound and unwound from the winch. The device comprises a co-planar pair of sheaves respectively mounted at opposite ends of a rotatable arm.

Abstract: A tensioner unit (12) comprising an inner cylinder (22), filled partially with hydraulic fluid, with a piston (26) and piston rod (28) reciprocal therein (sometimes referred to as a hydraulic cylinder) surrounded by a cylindrical chamber (40) (sometimes referred to as an accumulator) for hydraulic fluid and gas. The gas in accumulator (40) is pressurized to maintain the hydraulic fluid under pressure against the piston (26) placing the piston rod (28) under tension to provide the necessary tension force on a marine riser (14) and to compensate for the rise and fall of a floating platform. This is a self-contained integral unit with one end of the piston rod (28) connected to the riser (14), and the other end connected to a frame (16) supported on a platform of a TLP. A plurality of such tensioner units (12) on this frame (16) and connected to said riser (14) form a complete riser tensioner (10) without external accumulators.

Abstract: An improved compensating winch (10, 200) is disclosed which incorporates elastomeric elements (20, 118, 202, 204) which are deformable in torsional shear about the rotational axis of the drum of the winch to absorb shock loading of the cable (22) to increase the service life of the cable and winch and resist catastrophic failure. The elastomeric element can comprise a series of alternating elastomeric rings and rigid rings bonded together to form a unitary structure. Concentric elastomeric elements (202, 204) can be connected in a series relationship to provide for greater annular deflection of a drum versus a drive element.

Abstract: A traction sheave in particular for a lift moving machinery, by which the torque is transmitted from the machinery shaft to the ropes supporting the lift cage. The problem in lift traction sheaves of prior art with rigid construction is their objectionably strong tangential vibration, due to the machinery. In the invention this problem has been solved in that the outer rim of the traction sheave is connected to a flange on a hub by the aid of at least one elastic element, and that the outer rim is rotatably carried on the hub.

Abstract: A novel rope tension damper device is adapted to be installed, for example, at a location between a winch and the fairlead that guides the rope. The device comprises a co-planar pair of sheaves respectively mounted at opposite ends of a rotatable arm.

Abstract: Apparatus for controlling fluid communication with a fluid pressure system includes parallel flow paths connected to the system. A first flow path includes first valve apparatus for selectively closing the flow path. The second flow path includes relief valve apparatus responsive to fluid pressure in the second flow path to move from a closed configuration to an open configuration. Switching apparatus, including sensors for detecting the condition of the system, operate to close the first valve apparatus in response to pre-determined threshold values of such condition. Fluid communication from the system may thereafter occur along the second flow path at the relief valve apparatus opens in response to pressure buildup in the flow path. A third flow path, parallel to the first two flow paths, may be provided with throttling apparatus for controlled communication of fluid along such third flow path.

Abstract: A compensating device for avoiding swell-generated relative movements between a load suspended on a crane and a load placing surface, or between a crane hook and a load to be carried thereby, the compensating device comprises a hydraulic cylinder-piston unit including a cylinder with an inner space, a piston sealingly displaceable in the cylinder and subdividing the inner space into a load supporting chamber which is to be filled in operation with hydraulic liquid and a second chamber, a piston rod connected with the piston, and a hydraulic accumulator connected with the supporting chamber and accommodating a pretensioned gas cushion, the second chamber being filled in operation with hydraulic liquid, the hydraulic accumulator including at least one hydraulic accumulating element which is connected with the second chamber and accommodating a gas cushion with a low pressure, the piston rod extending through both the load supporting chamber and the second chamber and extending outwardly beyond end surfaces of t

Abstract: Disclosed is a compensator applicable for use with a traveling block supported from a mast, derrick or the like by means of a crown block wherein the traveling block may be utilized for supporting objects. Two fluid pressure piston-and-cylinder assemblies are arrayed on opposite sides of a line of travel of the traveling block relative to the crown block so that a flexible line positioned about the sheaves of both blocks passes over a pulley supported by one fluid pressure assembly to one side of the line of travel and, on the other side, the flexible line passes over a pulley supported by the other fluid pressure assembly. One end of the flexible line may be anchored relative to the mast as a deadline while the line at its other end may be selectively retracted or payed out by a drawworks or the like fixed relative to the mast. In one embodiment, the pulleys are carried by a carriage which is carried by the fluid pressure assemblies.

Abstract: An overload prevention apparatus includes a geared member with a number of teeth formed thereon, an engagement member including an engagement portion of which dimensions are determined so as to allow the latter to enter the valley on the geared member, a supporting member for turnably supporting the engagement member so as to allow the latter to turn toward and away from the geared member and a resilient member disposed between the engagement member and the supporting member to thrust the engagement portion on the engagement member toward the geared member. Either the geared member or the supporting member is arranged to move relative to the other. The direction of movement of the movable member is determined by the direction of extension of the teeth on the geared member. When hoisting ropes pull the movable member with excessively high force, the geared member is caused to move against thrusting force of the engagement member generated by the resilient member whereby the hoisting ropes are unreeled further.

Abstract: A transport system (10) for transporting a litter carrier (40) from one location onboard a first ship to a second location onboard another ship includes a retractable boom (12) having a stationary member (16) and a telescoping member (18) slidably engaged therein. Boom (12) also includes a hoist unit (28) which is operatively connected through a hoist cable (34) to carrier (40) to cause movement thereof. Carrier (40) includes acoustic rangefinders (50) and contact detectors (52) which are electrically coupled to a control circuit (60) located onboard one of the vessels through internal electrical conductors in hoist cable (34). Rangefinders (50) generate signals indicative of the distance between carrier (40) and a selected one of the ships. Contact detectors (52) provide signals which indicate whether carrier (40) is in transit or has landed onto a ship.

Abstract: A hydropneumatic cable tensioner is comprised of an enclosed cylinder featuring a plurality of annular chambers. A fixed cable sheave is mounted to one end of the cylinder. A movable cable sheave is mounted to a piston rod connected to a piston which reciprocates in a piston bore chamber of the cylinder. Regulated compressed gas is connected to the outer accumulator chamber of the cylinder thereby exerting high pressure forces on oil found in the middle or high pressure oil chamber of the cylinder. Pressurized oil forces a piston to move outwardly thereby increasing the distance between the two sheaves and tensioning a cable and containment chamber within the piston rod. Restriction ports between the piston bore chamber and the containment chamber within the piston rod regulate movement of the piston and prevent uncontrolled acceleration should a cable failure occur.

Abstract: The nacelle (3) is characterized in that it includes at least one cable (6) having a top end that leaves the nacelle upwardly and a bottom end that leaves the nacelle downwardly, and a mechanism (11) enabling the nacelle to move up and down the cable when the top end of the cable is hooked to a hook unit (4). A mechanism enables the top portion of the cable to be subjected to a tension greater than the weight of the nacelle while the bottom portion (7) of the cable is fixed to an anchor point, said tensioning mechanism serving to vary the distance between the nacelle (3) and said hook unit at the top end of the cable. Further, mechanism (12, 14) acts on command, on said tensioning mechanism in such a manner as to prevent the distance between the nacelle (3) and the hook unit (4) at the top end of the cable from shortening while not preventing it from lengthening.

Abstract: Disclosed is a compensator applicable for use with a traveling block supported from a mast, derrick or the like by means of a crown block wherein the traveling block may be utilized for supporting objects. Two fluid pressure piston-and-cylinder assemblies are arrayed on opposite sides of a line of travel of the traveling block relative to the crown block so that a flexible line positioned about the sheaves of both blocks passes over a pulley supported by one fluid pressure assembly to one side of the line of travel and, on the other side, the flexible line passes over a pulley supported by the other fluid pressure assembly. One end of the flexible line may be anchored relative to the mast as a deadline while the line at its other end may be selectively retracted or payed out by a drawworks or the like fixed relative to the mast. The crown block is supported by flexible lines passing over pulleys also supported by the fluid pressure assemblies.

Abstract: A motion compensating device that is installed on a lift line between a crane and an object to be lifted. The device limits dynamic loads on the line by taking up and letting out line by preventing the lift line from going slack and by lengthening acceleration time. The device consists of a hydraulic system and sheave mechanical system arranged in combination together with a balancing system for a given load range. The device is balanced for a given load range to provide a full range of compensation while hanging free. Balance is provided by offsetting a load line a calculated distance Y from a vertical line drawn through a lift point. This offset compensates for turning moments of the apparatus.

Abstract: A self-mobile electrically powered machine is provided with an electric cable for supplying power to the machine. The cable is suspended between a rotatable turret, which may include a reel, on the machine and a portable cable tower spaced from the machine. From the cable tower, the cable extends to a remote power source. Constant cable tension is provided by the turret reel, or by a sheaving arrangement on the cable tower. The cable tower base is provided with a slot whereby the machine is used to move the tower to different locations while still being supplied with electricity therefrom.

Abstract: A vehicle braking apparatus includes a braking mat assembly, a mounting unit for securing the mat assembly to the vehicle chassis, and a shock absorbing unit. The mat assembly includes a drum mounted on a shaft and a braking mat. The braking mat has a first portion secured to and wound around the shaft, an apron portion and a second portion intermediate the apron portion and the first portion. The apron portion forms an extension which has a free end secured by a restraining member to normally maintain the mat in an inoperative position. A release unit enables the retaining unit to release the mat from its inoperative position so that the mat can be unwound from the shaft and moved to its operative position between the vehicle wheels and the road surface. The shock absorbing unit includes a stop member extending parallel to and spaced from the shaft.

Abstract: A hydraulic or pneumatic cylinder supports a pair of non-circular discs and a circular pulley about which a hoisting cable and a carrying cable are trained. The discs are configured such that a constant force is exerted on a load supported by the hoisting cable independent of the variation in pressure in the cylinder due to displacement of the piston supporting the discs. The carrying cable comprises two runs; one having one end fixed to one of the discs and the other end fixed to the supporting base, and the other having one end fixed to the other disc and the other end fixed to a pulley block supporting the load. The hoisting cable extends from a winch, over the circular pulley, to the pulley block. The arrangement compensates for relative motion between the load and the supporting base.

Abstract: Motion compensated load-lifting apparatus for use on marine vessels. Apparatus includes a traveling weight used to maintain tension in the load-lifting member, and a locking mechanism to prevent movement of the traveling weight in one direction. The locking mechanism, such as a ratchet and pawl, can be employed to lift the load from the vessel at optimum periods of wave movement. Load direction sensing devices prevent attempted lift of the load as the vessel falls.

Abstract: A hydropneumatic cable tensioner is comprised of an enclosed cylinder featuring a plurality of annular chambers. A fixed cable sheave is mounted to one end of the cylinder. A movable cable sheave is mounted to a piston rod connected to a piston which reciprocates in the innermost or piston bore chamber of the cylinder. Regulated compressed gas is connected to the outer chamber of the cylinder thereby exerting high pressure forces on oil found in the middle or high pressure oil chamber of the cylinder. Pressurized oil forces a piston to move outwardly thereby increasing the distance between the two sheaves and tensioning a cable. Restriction means within the piston bore chamber regulate movement of the piston and prevent uncontrolled acceleration should a cable failure occur.

Abstract: A system for controlling the vertical movement of a drillstring and which is removably interconnected with a conventional drill rig. The system includes at least one fluidic cylinder and piston assembly removably connected at an upper end to a support, such as the rig's traveling block assembly, and at a lower end to the drillstring. A pump is operatively connected to the cylinder and piston assembly and a control valve device is provided to control the flow of the fluid to and from the cylinder and piston assembly. A computing device is in operative communication with a data measurement system and the control valve device and is used to automatically control the movement of the drillstring in response to data, such as WOB, received from the data measurement system.

Abstract: A compensating rope sheave tie-down uses a hydraulic control system comprising various valves to control sheave motion. The sheave is permitted by the control system to move up and down slightly at slow rates, but is held in place if a high rate occurs. The control also permits the sheave to drop down to apply tension to the compensating rope.

Abstract: An improved fork lift truck of the type having a telescopic mast assembly whereby proper tension is maintained on a section of hydraulic lines extending from a source of pressurized hydraulic fluid to a carrier member of the mast assembly to which various hydraulic units can be attached. The improvement includes sheave structure for guidingly receiving the section of the hydraulic lines and mounting structure for mounting the sheave structure to the mast assembly in such a manner that the section of hydraulic lines is substantially maintained within the confines of the mast assembly regardless of the position of the mast assembly.

Abstract: A cable tensioning apparatus and method for automatically maintaining and adjusting the tension forces in an endless cable for a ski lift, aerial tramway, etc. is disclosed. The apparatus includes a carriage on which the cable is carried, a pneumatic carriage displacement apparatus in the form of a piston and cylinder, a source of gas under pressure, and a regulator and relief valve connected to establish and maintain a pressure within the cylinder which falls between predetermined minimum and maximum pressures. As the aerial tramway is subject to passenger or cargo loading and ambient conditions which change the tension forces, the pressure in the pneumatic cylinder will vary within the preselected range, and upon a change in the tension force beyond the range, gas is automatically exhausted from or interjected into the pneumatic cylinder to maintain tension forces within the preselected range.

Abstract: A winch arrangement intended for the rapid shifting of aircraft or other wheeled vehicles which incorporate their own braking system and which may be under the control of an occupant during winching, is so constructed as to provide compensation for wide fluctuations in load on the winch due to a possible lack of coordination between operation of the winch drive and the control of the vehicle. The winched arrangement comprises a drive motor, a winch drum assembly coupled to the drive motor by means of a transmission incorporating a reduction gear said transmission being of relatively high inertia, so that it can run on to drive the winch drum and take up slack in the winch rope in the event of stoppage of the drive motor. The transmission preferably includes an eddy current overload coupling.

Abstract: A mooring apparatus for a semi-submersible oil exploration and drilling rig includes eight drum anchor hoists and winches on which are carried eight wire rope mooring lines. Each of these lines extends up over one of eight head sheaves and vertically down the outside face of the oil rig through a fairleader rotatably mounted with respect to the rig at a bottom submerged portion thereof. A linear line pull machine is mounted to the rig in encompassing relation to each of the vertical runs of mooring line between the head sheave and the fairleader. These eight mooring line assemblies are distributed around the periphery of the rig. Two mooring lines extend at 90.degree. from each other at each corner of the rig.

Abstract: A motion compensator for disposition between an offshore support and an offshore well string or the like movable with respect to the support comprises first and second compensator bodies interconnected with the support and the well string such that relative movement between the support and well string causes relative movement between the compensator bodies. The compensator bodies are further interconnected with each other for relative movement in generally vertical directional modes. A compressible fluid or the like is associated with the compensator bodies for resiliently resisting relative movement therebetween in a first directional mode. A position indicator associated with the compensator bodies comprises a flexible vessel having one end connected to one of the compensator bodies and the other end connected to the other compensator body generally below the one end.

Abstract: A carrier adapted to move between a movable vessel, such as a boat, and a stationary platform. The carrier has an extendable and retractable intermediate uphaul line adapted to be connected to a crane on the platform. It also has a downhaul line connected between the carrier and the vessel. When the carrier is being lifted from the vessel, the downhaul line is payed out at a controlled rate with the uphaul line extending and retracting to keep the carrier out of contact with the vessel which may be rising or falling due to wave action of the water. At a predetermined elevation, the tension in the downhaul line is decreased so that the uphaul line retracts to move the carrier out of the area of possible contact with the vessel. The reverse operation is followed to move the carrier from the platform to the vessel.