Abstract: A method for testing a lightning protection system in a wind turbine rotor blade is provided. The lightning protection system is contacted in the region of a rotor blade root. A measuring line having an electrically conductive tip is positioned in the interior of the rotor blade or outside on the rotor blade until the conductive tip is in contact with an element of the lightning protection system. A signal is fed via the measuring line and the signal arriving at the lightning protection system in the region of the rotor blade root is measured in order to check the mode of operation of the lightning protection system in the rotor blade.

Abstract: Power lines are installed with a rope brake apparatus that enables a rope to be suspended above the ground during installation and that thereby eliminates the need to block off the ground between power poles. The rope brake apparatus has a pair of opposed cam cleats mounted on a base adjacent each other for allowing movement of a rope between them in one direction and for preventing movement of a rope between them in an opposite direction.

Abstract: A system and method for performing a task on a LPS of a wind turbine includes a robotic testing device having a plurality of clamping arms and a LPS test probe coupled to a robotic end effector. The robotic testing device can be positioned around an outer perimeter of a rotor blade of the wind turbine. A cable, coupled to an up-tower anchor point, is attached to the robotic testing device and extends between the anchor point and a support surface. A lightning receptor of the LPS is between the up-tower anchor point and the tower support surface. As the cable is displaced, the robotic testing device moves to a position at which it is clamped to the rotor blade, adjacent the lightning receptor. The end effector moves to position the test probe in contact with the lightning receptor to conduct the test on the LPS.

Abstract: The Vertebral Osteotomy Saw Guide allows precise osteotomies to be performed through the vertebral column in conjunction with a thread-wire saw. The guide is designed so that it can mount to rods commonly used during spinal surgery for spinal stabilization. The mount of the guide is a polyaxial mount, allowing the angle of the guide mount to be adjusted and locked to create a desired cutting plane to produce a precise osteotomy. The guide itself consists of two interdigitated pulley wheels that allow the thread-wire saw to pass smoothly through the guide. The simple, but unique design of the guide allows a surgeon to perform an osteotomy through the vertebral column cutting from one side of the vertebral column to the other. This unique orientation allows the osteotomy to be performed away from critical structures in the region (the spinal cord, aorta, and inferior vena cava).

Abstract: A method for controlling an actuator of a hinged segment including the steps of: estimating an inertia J of the segment and a minimum viscous hinge friction f; estimating or measuring a traveling speed {dot over (X)} of the segment and an internal deformation ?X of the actuator; synthesizing a control law H? generating a control current (or torque) from the estimates or measurements and meeting a performance objective pertaining to a transfer function (I) between an acceleration {umlaut over (X)} of the segment and an external force F to which the segment is subjected: (II) with (III), ? being a mathematical artifact and s being the Laplace variable; and controlling the actuation of the hinged segment according to the control law thus synthesized.

Abstract: A support bearing, for example for straighteners, having an outer ring, an inner ring and rolling bodies that roll between the outer and inner ring on raceways. A bending moment prevails between the rings as a result of a load with a fixed direction of action. To compensate for the bending moment, an outer raceway of the inner ring and/or an inner raceway of the outer ring includes a profiling with a variable diameter in the axial direction. The profiling is adapted or approximated to a non-cylindrical bending line caused by the bending moment in the rolling contact, and the bending line is defined by a line, on which bending forces which are transmitted from the inner ring to the rolling bodies and are caused by the bending moment lie substantially perpendicularly. As a result, the disadvantageous edge loading in a given load direction is suppressed, with the result that more rolling bodies can transmit load between the rings at the same time.

Abstract: A positioning device (12), especially for a vehicle seat belt feeder, comprises a flexible load-bearing element (16) and a molded part (18) comprising a plurality of molded elements (20) each of which annularly surrounds the elastic load-bearing element (16) and includes axial bearing surfaces. The axial bearing surfaces of the molded elements (20) include a surface structure which is configured so that two neighboring molded elements (20) loaded against each other contact each other with their axial bearing surfaces, are in positive engagement and are orientated in the radial direction at a defined position relative to each other, A belt buckle device (10) comprises an afore-described positioning device (12) as well as a belt buckle (14) that is fastened to the load-bearing element (16).

Abstract: An apparatus for raising and lowering a vehicle cover is provided. The apparatus includes a flexible member having a first end and a second end, the flexible member configured to flex so that, with the first end positioned adjacent to a vehicle and the second and positioned generally higher than the vehicle, the second end raises the vehicle cover up from the vehicle and lowers the vehicle cover down towards the vehicle. The second end of the flexible member is configured to retain the vehicle cover.

Abstract: A line guiding structure comprises a round guiding shaft, a fixing unit, an elastic element, a linear bearing and a wheel set. The round guiding shaft comprises a fixing and an open end. The fixing unit is used for fixing the round guiding shaft and comprises a fixing base and a bearing. The fixing base is disposed on mechanical equipment, and the bearing is disposed in the fixing base. The elastic element is sleeved on the round guiding shaft and comprises a first end and a second end. The linear bearing is sleeved on the round guiding shaft. A connecting piece is disposed on the linear bearing. The wheel set comprises a fixing plate, a supporting frame and two pulleys. The fixing plate is connected on the connecting piece. A slide hole is formed between two opposite pulley surfaces of the two pulleys for a line to pass through.

Abstract: A serial robot includes a base, first and second segments, a proximal joint joining the base to the first segment, and a distal joint. The distal joint that joins the segments is serially arranged and distal with respect to the proximal joint. The robot includes first and second actuators. A first tendon extends from the first actuator to the proximal joint and is selectively moveable via the first actuator. A second tendon extends from the second actuator to the distal joint and is selectively moveable via the second actuator. The robot includes a transmission having at least one gear element which assists rotation of the distal joint when an input force is applied to the proximal and/or distal joints by the first and/or second actuators. A robotic hand having the above robot is also disclosed, as is a robotic system having a torso, arm, and the above-described hand.

Abstract: Disclosed is an impact-reduction box through which the hoisting ropes of a mining shovel or other machine pass. The impact-reduction box includes a roller frame subassembly and spring box subassemblies attached thereto on either side. The impact-reduction box is configured so that when the hoisting cables impact the box during undesirable whipping, the roller frame subassembly will move in reaction while the spring box subassemblies will remain essentially motionless. The mining shovel will feel less of the impact of the jolting hoisting rope, and the rope will not suffer the wear and tear of frequent slapping against the machine such that the rope will be less likely to completely break.

Abstract: An apparatus comprising a receptacle defining therethrough a central bore and a pair of opposed slots extending from the central bore. The apparatus has a support surface surrounding in part the central bore and slots. The appartus further has a stud assembly comprising a stud and an engagement pin extending orthogonally to the stud. The stud is removably inserted into the central bore and raised such that the pin passes through the slots. The stud is then rotated such that the pin rests on the support surface. The apparatus also has a pulley assembly attached to the stud assembly.

Abstract: An improved crown pulley assembly attached to an upper end of a vertical drilling rig derrick mast used in conjunction with an improved top drive assembly which is used within the drilling rig derrick for the drilling of a well, the improved crown pulley assembly having a crown frame supporting a plurality of pulleys with the top drive providing two sets of paired top drive pulleys, the pulleys suspending a single drive cable through the plurality of pulleys with an anchor end of the single drive cable affixed below the derrick and the winch end of the cable attached to a winch to raise and lower the improved top drive assembly within the drilling rig derrick.

Abstract: A motorized improved winch for raising and lowering, for example, theater scenery by means of cables and which incorporates a tubular support enclosure for supporting and housing a moving drum and the required components for emergency braking and for moving the drum in synchronization with relation to the cable guiding means, preferably mounted on the tubular support enclosure, and for driving the electrical sensors (limit switches and encoder) if desired. The winding and unwinding of the cables on or off the drum does not change the cable runs relative to the cable guiding means. The improved winch can be used in theaters and can be installed at the sides of the stage, up at the stage gridiron, or above the gridiron. With this improved winch counterweights are unnecessary. The improved winch is compact and can be easily manufactured.

Abstract: A motorized improved winch for raising and lowering, for example, theater scenery by means of cables and which incorporates a tubular support enclosure for supporting and housing a moving drum and the required components for driving, emergency braking and for moving the drum in synchronization with relation to the cable guiding means, preferably mounted on the tubular support enclosure, and for driving the electrical sensors if desired. A new feature of this improved winch includes alternate means for supporting the winch unit from the tubular support enclosure through rollers, mounted to the inside of the tubular support enclosure and engaging the support means part of the movable winch unit. Another new feature is an option to use more than one driving means for increased capacity. The improved winch can be installed at the sides of the stage, up at the stage gridiron, or above the gridiron.

Abstract: A curtain cable maintaining device includes a cable maintaining unit having a bottom board with a guide hole defined therethrough. A pulley set is connected on the bottom board and has a first pulley and a second pulley. The cable is wrapped to the scrolling unit, the mandrel unit, the first pulley and the second pulley, and extends through the guide hole. The cable does not contact the periphery of the guide hole so as to reduce the friction with the guide hole and the cable does not hook with the mandrel unit when moving.

Abstract: A lift system is provided. The lift system includes a lift mechanism with a jamming cleat and a guide bracket that urges a tensile member toward the jamming cleat.

Abstract: A lift assembly system and method can include: a funnel-shaped drum having a constant diameter portion and a gradually increasing diameter portion; a cable management system adapted to position a cable in a single layer in a tray; a beam clamp tube receiver adapted to allow a tube to slide relative to a beam and be secured to the beam; a cable keeper and a slack line detector adapted to maintain cables in position about a drum upon loss of cable tension; a horizontally oriented low profile cable adjuster adapted to adjust the length of a cable; an overspeed braking mechanism; a fleet pivot arm pivotable on the end of a tube so as to guide cables along a desired fleet angle; and/or a pull-type load sensor connected between a tube and a drum adapted to sense changes in a load force and adjust movement of a load.

Abstract: A power winch for retrieving a load using a strap comprising: a motor, where the motor includes a drive shaft, where the drive shaft extends from the motor and a gear coupling at the end of the drive shaft; at least one gear reducer; at least one drive shaft, where said drive shaft engages the at least one gear reducer; a gear extension in each drive shaft; and four rollers that engage the gears of the at least one drive shaft where the rollers are designated as a first top roller, the second top roller, a first bottom roller, and a second bottom roller, where the first top roller and first bottom roller are aligned in a first vertical plane and a second top roller and second bottom roller are aligned in a second vertical plane. The four rollers are positioned at four different respective vertical heights. A strap interweaves through the four rollers that allows for the movement of the strap through the rollers powered by the motor.

Abstract: A pulley apparatus (10), includes a dram (12) having a central axis mounted between two side plates (14, 16) for receiving a rope (120) passing around the drum. The dram (12) defines a cylindrical surface for receiving a rope or line. The pulley apparatus includes holes (14a, 16a) for hanging or supporting the pulley from a hook karabiner or the like. A rope guide means (30, 32) is defined on the underside of the pulley adjacent the dram and passing over the cylindrical surface of the dram for guiding the line to wrap around the central part of the dram and inhibiting overran of ropes. The guide means comprise two curved blades (30, 32) which extend from the side plates and bow out towards the center of the dram to define a convergent-divergent wasp-waisted passage for the line to pass through. A second single, freely rotatable sheave (40) is mounted to the apparatus between the lower ends of two plates (42, 44) whose upper ends are pivotally mounted to the side plates, and hangs below the guide means in use.

Abstract: One aspect of the invention relates to a device that efficiently folds and organizes tubing and cords while not compromising their function. In certain embodiments, the device provides dynamic length adjustment in the form to reducing line length, and the device organizes the lines in parallel, making it easier to identify their connections.

Abstract: An assembly (20) for controlling movement of an elevator car (12), which includes a sheave (18), a first mass (32a, 48a), a second mass (32b, 48b), and a coupler (54) that provides a releasable non-elastic connection between the masses. The sheave (18) is configured to rotate about an axis of rotation (30) at a velocity related to a velocity of the elevator car (12). The first (32a, 48a) and second (32b, 48b) masses are attached to the sheave (18) at first and second pivot points (42a, 42b) radially spaced from the sheave axis of rotation (30). The coupler (54) that provides the releasable non-elastic connection between the first (32a, 48a) and second (32b, 48b) masses is configured to prevent pivotal movement of the masses at sheave angular velocities less than a first velocity and to permit pivotal movement of the masses at velocities greater than the first velocity.

Abstract: A positioning device has a deformable load-bearing element (10), a shaped part (12) coupled to the load-bearing element (10), and a holder (24). The load-bearing element (10) is adapted to be shifted from a first position in which the shaped part (12) is held in a first shape by the holder (24), into a second position in which the shaped part (12) is at least partially no longer held by the holder (24) and takes a second shape which is transmitted to the load-bearing element (10).

Abstract: A lift assembly system and method can include a substantially rectangular tube, a motor operably connected to first and second traction drives and a rotatable drum and structurally connected to one end of the tube, a head block fixed to the opposite end of the tube, and a plurality of loft blocks positionable at an infinite number of locations within the tube. An elongate member attached on one end to the drum can be routed through a generally horizontal path from the drum to the first and second traction drives, the head block, and the loft blocks, and then through a generally vertical path from the loft block to an attached article. The elongate member can be wound about the drum to raise the article, and unwound from the drum to lower the article. The system can further include a load-side braking mechanism. The tube can include a compressible material adapted to absorb at least a portion of a horizontal load placed on the lift system.

Abstract: Disclosed is an impact-reduction box through which the hoisting ropes of a mining shovel or other machine pass. The impact-reduction box includes a roller frame subassembly and spring box subassemblies attached thereto on either side. The impact-reduction box is configured so that when the hoisting cables impact the box during undesirable whipping, the roller frame subassembly will move in reaction while the spring box subassemblies will remain essentially motionless. The mining shovel will feel less of the impact of the jolting hoisting rope, and the rope will not suffer the wear and tear of frequent slapping against the machine such that the rope will be less likely to completely break.

Abstract: A winching apparatus includes a fairlead mounted to a vehicle and a fifth roller mounted below the fairlead that is positioned and sized such that the cable does not contact any portion of the vehicle between the fairlead and the fifth roller when the cable passes from the winch and under the vehicle.

Abstract: A system and method are disclosed for locating a maintenance device approximate an area of interest of a wind turbine. The system generally includes a carriage configured to support the maintenance device and a cable having first and second ends attached to the carriage. Additionally, the system includes first and second anchor points, with the first anchor point being disposed adjacent to a component of the wind turbine. The second anchor point is spaced apart from the first anchor point such that the area of interest is generally disposed between the first and second anchor points. The cable may be coupled along its length between the first and second anchor points such that, as the cable is displaced, the carriage is moved to a position at which the area of interest is accessible to the maintenance device.

Abstract: A pulley apparatus (10), includes a dram (12) having a central axis mounted between two side plates (14, 16) for receiving a rope (120) passing around the drum. The dram (12) defines a cylindrical surface for receiving a rope or line. The pulley apparatus includes holes (14a, 16a) for hanging or supporting the pulley from a hook karabiner or the like. A rope guide means (30, 32) is defined on the underside of the pulley adjacent the dram and passing over the cylindrical surface of the dram for guiding the line to wrap around the central part of the dram and inhibiting overran of ropes. The guide means comprise two curved blades (30, 32) which extend from the side plates and bow out towards the centre of the dram to define a convergent-divergent wasp-waisted passage for the line to pass through. A second single, freely rotatable sheave (40) is mounted to the apparatus between the lower ends of two plates (42, 44) whose upper ends are pivotally mounted to the side plates, and hangs below the guide means in use.

Abstract: A portable winch and method of use is shown. One advantage of winches shown includes an ability to lower a boom or boom sections into limited access exit pit for winching operations such as pipe bursting. Sectional boom designs shown provide the ability to easily raise and lower a boom large distances without the need for a single long boom. Selected winch designs shown include flexible inserts between the boom and the winch frame that help resist damage from unforeseen shifting of the device during operation. Designs and methods shown also include multiple pulleys on a boom end unit. Fasteners are shown that reduce build up of debris.

Abstract: A pulley actuator implements a motor to drive a screw and a guide rod to relatively expand or retract while utilizing one flexible rope and two pulleys to drive three telescoped tubes to relatively expand or retract move correspondingly. The pulley actuator has a simplified structure as compared with the known devices and is easy to fabricate.

Abstract: A modular lift assembly configured for attachment between two substantially parallel support beams includes a chassis, at least one lift component attached to the chassis, a telescoping or other adjustable stiffener, and at least one attachment assembly. The chassis has a plurality of grooves formed in one surface thereof. The telescoping or other adjustable stiffener is disposed in at least one of the grooves and engages facing surfaces of adjacent parallel support beams. The attachment assembly is disposed in another of the grooves formed in the chassis for engaging at least one of the adjacent support beams.

Abstract: A load balancing hoist constructed to combine the power module and the travel module of the hoist into a single unit to substantially reduce the cost and the length of the hoist without effecting its operation and application.

Abstract: A lift assembly system and method can include a substantially rectangular tube, a motor operably connected to first and second traction drives and a rotatable drum and structurally connected to one end of the tube, a head block fixed to the opposite end of the tube, and a plurality of loft blocks positionable at an infinite number of locations within the tube. An elongate member attached on one end to the drum can be routed through a generally horizontal path from the drum to the first and second traction drives, the head block, and the loft blocks, and then through a generally vertical path from the loft block to an attached article. The elongate member can be wound about the drum to raise the article, and unwound from the drum to lower the article. The system can further include a load-side braking mechanism. The tube can include a compressible material adapted to absorb at least a portion of a horizontal load placed on the lift system.

Abstract: A theater rigging assembly having a beam, which is attached to structural support members of a theater or other performing arts venue. The assembly further includes a winch assembly and head block that can be positioned at any point along the beam and selectively fixed in position. The winch portion includes cables for raising and lowering battens or other loads. The head block includes head sheaves, which redirect the cables to loft sheaves that are selectively attached to the beam. The head sheaves are diagonally displaced to separate the cables. The winch portion includes a motor, a gear box, a drum and a brake. The brake includes a ratchet and two brake disks. It uses at least one friction surface that contacts at least one of the brake disks to cause a pawl to engage or disengage from the ratchet.

Abstract: A system is described for handling a wire, a chain, a cable, etc. (12) onboard a vessel, comprising a number of winches (10) to pull in and let out said wire, chain, etc. (12), and also a number of tow pins (14) and shark jaws (16), mounted in an area at the stern of the vessel, and which is arranged to guide and/or to hold said wire, chain, etc. (12) that runs from or to said winches (10). The system further comprises at least one centering device (18) arranged between said tow pins (14) and shark jaws (16) and winches (10), preferably adjoining said tow pins (14) and shark jaws (16), where the centering device (18) comprises at least two guiding plates (20) that can be raised and lowered and which are arranged to guide and possibly to hold said wire, chain, etc. (12).

Abstract: A ceiling-mounted bicycle storage hoist including a first elongated structural member (36) and a second elongated structural member (38). The first elongated structural member is connected to the second elongated structural member, forming a V-shaped structural assembly spanning at least 1220 mm in one direction, to enable attachment to ceilings comprising wooden joists spaced at 305 mm, 406 mm, 488 mm, or 610 mm intervals. A first, second, and third rope and pulley system are attached to the first and second elongated structural members. The first, second, and third rope and pulley systems converge at a location near the connection between the first and second elongated structural members, enabling a user to control the first, second, and third rope and pulley systems simultaneously. A bicycle may be attached to the first, second, and third rope and pulley systems and hoisted in a horizontal orientation.

Abstract: The invention comprises an anchor, rope and pulley system to load and unload cargo into and out of passenger vehicles. The anchor system comprises two load bearing straps and a means to attach the straps together. The straps are looped around the vehicle's side handle grips. The looped straps attach to each other near the center of the cargo area. The rope and pulley system comprises a rope, a large pulley, a small pulley, a means to attach the rope and pulley system to the anchor system, a means to attach the cargo to the rope and pulley system, and a means to clamp the rope to create a handle. Cargo can be lifted into a vehicle by pulling the handle with one hand and guiding the cargo with the other hand. A durable guard material over the cargo area's point of entry protects the vehicle and cargo from damage.

Abstract: A theater rigging assembly having a beam, which is attached to structural support members of a theater or other performing arts venue. The assembly further includes a winch assembly and head block that can be positioned at any point along the beam and selectively fixed in position. The winch portion includes cables for raising and lowering battens or other loads. The head block includes head sheaves, which redirect the cables to loft sheaves that are selectively attached to the beam. The head sheaves are diagonally displaced to separate the cables. The winch portion includes a motor, a gear box, a drum and a brake. The brake includes a ratchet and two brake disks. It uses at least one friction surface that contacts at least one of the brake disks to cause a pawl to engage or disengage from the ratchet.

Abstract: A device for lifting and lowering a cover from a lower surface of a roof includes four lines connected to the ends of a top panel of the cover. The lines pass through eyes on the cover at the midsection of the top panel, then through pulleys on the lower surface of the roof, then to a cleat on a wall. Pulling the lines lifts the cover off the vehicle.

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 pulley is provided having a first plate and a second plate arranged adjacent to the first plate and connected to the first plate by an axle. An eccentrically mounted sheave is located between the first plate and the second plate and is adapted to freewheel in one direction only. The eccentrically mounted sheave is mounted eccentrically with respect to the axle. A fixed block is mounted between the first plate and the second plate and is adapted to fixedly lock a line between the fixed block and the eccentrically mounted sheave.

Abstract: A range of mixed support and compression sheave assemblies is formed from standard 2S2C modules each comprising: two compression sheaves (11) and two support sheaves (12) respectively mounted rotating freely on the ends of two pairs of holding arms (15,16; 18,19) articulated on one another by a first upper joint pin (17) and a second lower joint pin (20), a first damping element (24) inserted between two bearing edges (22,23) securedly fixed to the two holding arms (15,16) of the compression sheaves (11), a second damping element (27) inserted between two bearing edges (25,26) of the two holding arms (18,19) of the support sheaves (12), and a frame (28) connecting the first and second joint pins (17,20), said frame being arranged to be connected to the end of a beam (14) with a swivel-pin (21).

Abstract: A screw, nut and cable transmission device (6, 7, 12, 13, 20 and 21) between a motor (5) and a device (1, 2) which is to be moved and which is made up of at least one double pulley (14), which amplifies the movement of the cable line (20) which is close to the device, relative to that of the cable line (12) which is close to the screw (7). By sacrificing part of the usual advantage of reduction of movement provided by the screw, (7) a greater movement travel for the device (1) is obtained for the same size constraints or constraints due to the length of the screw (7).

Abstract: A protective lifting system includes first and second mounting hooks each having, respectively, a line and pulley connection eyelet ring mounted thereon and a mounting bar connection eyelet ring mounted thereon which extends generally perpendicular to the shank section of the mounting hook, a pulley device mounted on the second mounting hook, a lift line having a first end connected to the first mounting hook and a second end which extends through the pulley device, a mounting bar operative to engage the mounting bar connection eyelet ring on the first and second mounting hooks to lift the hooks into an elevated supported position, the lift line being operative to lift an object to a safe elevated position by drawing the second end of the lift line through and away from the pulley device thereby decreasing the length of the lift line extending between the first and second mounting hooks.

Abstract: A lift assembly having a drum rotatably mounted to a frame and linearly translatable with respect to the frame. A plurality of head blocks are connected to the frame along a helical mounting path, wherein linear translation of the drum during takeoff or take-up maintains a predetermined fleet angle between a take off point from the drum and the head block. A loft block is disposed within the frame for defining a vertical cable path from within a footprint of the frame.

Abstract: The invention is a compact drive for a counterweight-assisted winch which can be retrofitted into existing manually operated systems that use counterbalancing weights. The counterbalancing weight will be fixed at a first predetermined percentage of the maximum capacity of the set, preferably about 50%. The winch is rated at a second predetermined percentage of the maximum capacity of the set, preferably about 50%. Together the first and second predetermined percentages sum to at least 100% of the maximum capacity of the set. By using the winch in a closed loop configuration, it will operate the set at any load from 0 to 100% of the set's rated capacity, without the need to adjust the counterbalancing weights. The compact drive system employs two motorized winches positioned along the long axis of two adjacent counterweight rigging systems, each winch engaging a respective chain used to move a counterbalancing weight.

Abstract: A lift assembly having a drum rotatably mounted to a frame and linearly translatable with respect to the frame. A plurality of head blocks are connected to the frame along a helical mounting path, wherein linear translation of the drum during takeoff or take-up maintains a predetermined fleet angle between a take off point from the drum and the head block.

Abstract: A cage in which two pulley wheels are mounted with tangent circumferences so that their circumferential cable grooves surround a cable passing between the wheels. The cage freely rotates about an axis that passes between the wheels. The cage axis is normal to the plane of the parallel wheel axes. The cage extends forward of the wheels and forms two curved edges on opposed sides of the cage axis. Each curve has an apex at its forward-most point. A flexible cable passes through the cage, between the wheels, and forward between the curves. Extending the cable substantially away from the plane of the wheels causes it to contact one of the curves. This rotates the cage so that the wheels are aligned with the cable deflection. This switches the cable to one or the other of the wheels, and provides low friction cable operation for any cable direction.

Abstract: A lifting unit, comprising a frame for supporting a motorized winch, at least one first tackle and one second tackle, the first tackle being interposed between the second tackle and the winch, each tackle being provided with two blocks, a fixed one and a movable one, and each comprising at least one pulley, and a flexible element, with a first end connected to the winch and wound around the pulleys, to form at least one initial loop around the first tackle, an outgoing portion from the first tackle to the second tackle, at least one intermediate loop around the second tackle, a return portion from the second tackle to the first tackle, and at least one end loop around the first tackle, the second end of the flexible element being connected to the frame, and a temporarily locking element for locking sliding of the flexible element.

Abstract: An assembly for felling a segment of a tree trunk in a safe and controlled manner and method of using the same. The assembly comprises a vertical support structure having an elongated base portion, an elongated mast portion connected to the base portion or integrally formed therewith and having at least a portion extending upwardly therefrom, and a horizontal lip extending from the base or integrally formed therewith for contacting engagement with a conventional notch formed in the trunk. The method of felling a tree trunk comprises positioning the tree felling assembly along the trunk, cutting a conventional notch in the trunk below the assembly, the notch having a lower surface, repositioning the assembly along the trunk so that the lip is in contacting engagement with at least a portion of the lower surface, securing the assembly to the trunk below the segment, cutting the segment from the trunk, and lowering the segment from the trunk along a take-away cable operatively engaging the assembly.