Abstract: A pendant assembly for a rescue hoist may comprise a pendant, an interface box discrete from the pendant, and a display screen discrete from the pendant. The pendant may include a hoist input. The interface box may be configured to receive a control input from the pendant. The display screen may be configured to receive a display command from the interface box.

Abstract: Methods and systems are provided for adjusting operation of a motor of a winch. In one example, a system for a winch includes a controller adapted to adjust operation of a motor of the winch based on one or more of and/or each of a winch load limit, a motor temperature, a distance of a hook coupled to an end of a rope of the winch to a winch fairlead, and an amount of rope wound onto a drum of the winch.

Abstract: The present disclosure relates to a control unit for controlling operation of a hoist in a load slip condition. The hoist may include a motor coupled to a winding drum for lifting and lowering a load. The control unit may include a processor and a memory communicatively coupled to the processor. The memory may store processor executable instructions, which, on execution, cause the processor to operate the hoist for selectively lifting and lowering a load between a first position and a second position upon detecting a load slip condition. The processor may operate the hoist based on parameters pertaining to transport of the load. The control unit may be configured to reciprocate the load in a load slip condition to prevent overheating and failure of a motor, thereby preventing a fall of the load in a work area.

Abstract: The invention relates to a motor-operated crane drive in which a more rapidly rotating motor (1) drives a more slowly rotating cable drum (3) via a transmission (3). A safety brake (5) is arranged on the more slowly rotating side of the transmission (2). A signal that is used for actuating the safety brake (5) is utilized for initiating an electrical deceleration of the motor (1).

Abstract: A system to transfer people and/or cargo during offshore operations includes a base with a stationary part and a moveable part that is rotatable relative to the stationary part about a substantially vertical first axis; a support arm having a first free end and a second free end opposite the first free end of the support arm; a boom having a first free end and a second free end opposite the first free end of the boom; a load support element; a measurement system; an actuator system; and a control system. The support arm at a location in between the first and second free end of the support arm is mounted to the moveable part of the base such that the support arm is rotatable relative to the moveable part about a substantially horizontal second axis.

Abstract: A system is disclosed including but not limited to a processor; a hybrid power source for servicing a system load, the hybrid power source comprising a natural gas engine, a diesel engine and a battery; a linear computer program comprising, instructions determining a current system load serviced by power provided from the hybrid power source; instructions to determine a current operating state for the natural gas engine, the diesel engine and the battery; instructions to use linear programming to determine a new operating state for the natural gas engine, the diesel engine and the battery to reduce for power consumption servicing the current system load the natural gas engine, the diesel engine and the battery; and instructions to replace the current operating state for the natural gas engine, the diesel engine and the battery to the new operating state for the natural gas engine, the diesel engine and the battery.

Abstract: Embodiments described herein may help to provide medical support via a fleet of unmanned aerial vehicles (UAVs). An illustrative UAV may include a housing, a payload, a line-deployment mechanism coupled to the housing and a line, and a payload-release mechanism that couples the line to the payload, wherein the payload-release mechanism is configured to release the payload from the line. The UAV may further include a control system configured to determine that the UAV is located at or near a delivery location and responsively: operate the line-deployment mechanism according to a variable deployment-rate profile to lower the payload to or near to the ground, determine that the payload is touching or is within a threshold distance from the ground, and responsively operate the payload-release mechanism to release the payload from the line.

Abstract: A hybrid winch system is disclosed, including but not limited to an electric winch; an electric generator for providing generator power to the electric winch; a battery for providing stored power to the electric winch; an anchor cable wound around a roller drum for the electric winch; an anchor attached to a distal end of the anchor cable; and a controller for applying the generator power and the stored power to the electric winch. A method for controlling the hybrid winch is also disclosed.

Abstract: A lighting system is provided having a movement system, a light source repositionable via the movement system, a sensor, a controller, and a communication system. The controller may control characteristics of the light emitted by the light source, rotation of the panel by the movement system, and receiving signal information from the sensor. The communication system exchange data between the controller and an external device, the light source and the movement system being remotely controllable by logic received using the controller via the communication system. The light source, the movement system, the controller, the sensor, and the communication system are installable in a drone. Wearable apparatus may be used with the system. Objects may be tracked and illuminated.

Abstract: One embodiment of the present invention relates to an assisted braking belay system with a housing, camming mechanism, and clutch mechanism. The housing may include a substantially enclosed rope channel through which a rope may extend to the climber. The camming mechanism is moveably coupled to the housing and configured to automatically engage a camming surface upon the rope across the rope channel if the rope translates through the channel at a particular acceleration rate. The clutch mechanism may function as a secondary locking mechanism to engage the camming surface of the camming mechanism upon the rope across the rope channel.

Abstract: The invention relates to an assembly system for a mobile crane auxiliary lifting unit comprising auxiliary lifting unit assembly fastenings which are coupled to the auxiliary lifting unit and serve to fasten the auxiliary lifting unit to the crane, and comprising an assembly unit which can move the auxiliary lifting unit assembly fastenings into an assembly position. It also relates to an assembly installation for a mobile crane auxiliary lifting unit, comprising such an assembly system and comprising a sub-structure. A footing support for a mobile crane auxiliary lifting unit and a method for assembling a mobile crane auxiliary lifting unit are also disclosed.

Abstract: A hybrid winch system for use with an anchor handling vessel comprises an electric winch mountable on the anchor handling vessel, an electric generator for providing generated power to the electric winch, a battery for providing stored power to the electric winch, an anchor cable wound around the electric winch and passing over a roller drum for guiding the anchor cable, an anchor attached to a distal end of the anchor cable and a winch controller for selectively applying the generated power and the stored power to the electric winch. The winch controller is configured to provide the stored power to the electric winch for controlled release of the anchor cable in case of loss of the generated power.

Abstract: Methods of optimized video transfer are described in which display data is divided into a plurality of portions, each portion corresponding to a class of image data, and the different portions are encoded for transmission to a remote display device using different encoding schemes. In an embodiment, the composite display data is never rendered at the source device and instead portions of display data are generated by an application based on an advertised set of classes of image data. In other embodiments, the composite display data is stored in a framebuffer at the source device and is split into portions according to a classification of the display data. In various embodiments the classification may be performed based on sniffing graphics commands used to generate the composite display data and in other embodiments, the classification may be performed based on a rate of change of pixels in the composite display data.

Abstract: A pulling tool is provided with a rotatable drum having a cable wound thereon. A motor is drivingly connected to the rotatable drum and the rotatable drum and motor are disposed within a unique housing structure. The rotatable drum is driven by a planetary gear system that is disposed within the rotatable drum to provide a compact assembly. A belt and pulley system is provided for delivering torque from the motor to the planetary gear system. The rotatable drum is provided with a two-piece stepped construction that allows the planetary gear system to be assembled within the drum and allows for the initial wraps of a cable around the smaller diameter portion of the stepped drum.

Abstract: Illustrative embodiments of apparatus and methods for braking a hoist system are disclosed. In one illustrative embodiment, a hoist system includes a winch drum and an air motor coupled to the winch drum. The hoist system further includes a brake coupled to the winch drum and operable to stop rotation of the winch drum and an over-speed sensing device configured to sense a speed of the winch drum. The over-speed sensing device includes a pneumatic switch operable to disconnect an air supply from the air motor and engage the brake to stop rotation of the winch drum and a centrifugal clutch coupled to the winch drum and configured to rotate at a rotational speed proportional to the speed of the winch drum. The centrifugal clutch operates the pneumatic switch when the rotational speed of the centrifugal clutch reaches or exceeds a threshold rotational speed.

Abstract: The present invention provides techniques relating to an operating device exhibiting superior dust resistance and water resistance, and more particularly to an operating device exhibiting few design restrictions and a small assembly operation load, and to a moving apparatus including the operating device. In an operating device having, in a casing, a detection unit for detecting input relating to an instruction to operate a driving device that drives movement of an object, a plurality of the detection units are arranged over a partial or entire range of a circumference of the casing in accordance with movement directions of the object.

Abstract: A cable hoist having an emergency braking arrangement comprising a dual toothed wheel assembly driven via a cable drum of the hoist. One of two toothed wheels of the toothed wheel assembly is sensed by a sensing lever of an anchor and an opposite end of the anchor interacts with a ratchet wheel of the toothed wheel assembly. As soon as an over speed occurs, the anchor engages in the ratchet wheel and causes a rotary movement of a carrier on which the anchor is mounted. This rotary motion is used to trigger a mechanical braking arrangement coupled to the cable drum.

Abstract: Synchronization assembly and plant for laying cables such as electric conductors, optical fibers, ropes or suchlike. The machines of the assembly and plant are distinct and independent with respect to each other and each includes unwinding members having at least a pair of capstans to unwind the cables, and corresponding traction/collection members having at least a pair of capstans to wind the cables fed from the relative unwinding members. The synchronization assembly and plant includes automatic adjustment members that adjust the speed of rotation of the capstans of at least two unwinding members or two traction/collection members of the laying machines, so as to maintain the winding/unwinding speed of the cables stretched by each machine substantially equal.

Abstract: The invention is directed to a process for making a golf ball having a multi-layered cover including a very thin outermost cover layer, the process comprising for example: forming first and second substantially hemispherical half shells having a thickness and comprising a thermoplastic composition, each half shell further having an outer surface and an inner surface, the inner surface forming an hemispherical cavity; dispensing an uncured liquid thermoset composition into the hemispherical cavity of the first half shell; inserting a first half of the core subassembly into the hemispherical cavity of the first half shell and displacing an amount of the uncured liquid thermoset composition such that the uncured liquid thermoset composition forms an inner cover layer having a thickness; inserting a second half of the core subassembly into the hemispherical cavity of the second half shell and displacing an amount of the uncured liquid thermoset composition such that the uncured liquid thermoset composition forms

Abstract: An endless cable winch or hoist which is particularly suited for a service lift comprises a working cable and a safety cable, further comprises a driving cable pulley around at least a part of which the working cable is wrapped, further comprises a drive for driving the driving cable pulley, further comprises a non-driven safety cable pulley, which is rotatably mounted in a housing and around at least a part of which the safety cable is wrapped, and further comprises an arresting device which is coupled via a brake to the cable pulley and which blocks and brakes the safety cable by means of the brake when the safety cable moves with a predetermined speed at least in one direction.

Abstract: An endless cable winch includes a working cable, a housing, in which is mounted a driving cable pulley around at least a part of which the working cable is wrapped, and further includes a drive for driving the driving cable pulley, wherein the housing is mounted so as to be pivotable about a pivot axis, and a sensor is provided for detecting a pivoting movement of the housing for detecting an overload state of the working cable.

Abstract: An electrically driven mooring winch is provided. The mooring winch includes a winding drum, an AC motor configured to drive the winding drum, a frequency conversion unit connected to the AC motor, and a control unit configured to control the frequency conversion unit on the basis of an indicator for tension of the mooring rope. The control unit is configured to set a reference value of rotational speed of the AC motor to a predetermined value, drive the AC motor in one direction for a predetermined time interval, define a first value of a torque of the AC motor, drive the AC motor in an opposite direction for the predetermined interval, define a second value of the torque of the AC motor, and compute a torque estimate using the first and second values of the torque.

Abstract: A modular lift assembly includes a frame, at least one head block connected to the frame, a drum rotatably connected to the frame about an axis of rotation and having at least one winding section, and a drive mechanism operatively connected to the drum for rotating the drum. In various examples, the lift assembly includes at least one loft block internal or external relative to the frame. The loft block is configured to guide a cable from the at least one head block to a load. The lift assembly can further include a load brake positioned along the axis of drum rotation to reduce risks associated with a drive or motor failure.

Abstract: Controlling the orientation of a load suspended from a bearing wire employs one master winch, one slave winch and a winch control. Each of the winches has a motor and a bi-directional rotational spool with a tagline. The winches are on the ground, the crane or the load. Each tagline is attached to the load for applying a controlled torque to the load about the bearing wire. The control system comprises tagline tension sensors and spool rotation sensors. The control system is connected to each winch motor for simultaneously rotating the winch spools, until preset tagline tensions are sensed during horizontal and/or vertical movement of the load. If necessary, the spools are rotated with rotation speeds for maintaining a desired orientation of the load, based on the determined tagline tensions. After relieving tagline tensions, the taglines are disconnected from the load.

Abstract: In a preferred embodiment, a restraint system is described for restraining a standing occupant in a vehicle such as a plane or helicopter. The restraint system includes a webbing strap that winds and unwinds from a spool assembly. The spool assembly includes a trigger assembly that locks a spool from rotation, a manual release assembly for manually releasing the trigger assembly and lock, and an adjustable payout assembly that determines the maximum length that the webbing strap can be pulled out before stopping (i.e., the number of rotations of the spool). The trigger assembly can trigger the lock assembly from one or more sensors. Further, the trigger assembly can be arranged to automatically unlock after a triggering event, manually unlocked after a triggering event or a combination of the two for different sensors.

Abstract: A hoist system with an overspeed detection sub-system for detecting overspeed by comparing an actual drum assembly speed with a target value. For example, the rotation of a motor may be determined by a first rotary encoder and the rotation of a drum may be determined by a second rotary encoder. The output of the first rotary encoder (the basis of a target value) is compared with the output of the second rotary encoder (corresponding to actual motion of the drum). If the difference between the target value and the actual motion is too large, then a problem, such as a broken hoist hardware component may exist, and appropriate remedial action is taken, such as braking the motor and/or the drum.

Abstract: A hoisting device or crane can be operated with at least two different maximum loads. The maximum load that can be hoisted in each case is correlated with the hoisting speed in order to prevent the dynamically developed peak load from exceeding the predetermined allowed load limiting values of the components of the crane or the hoisting device.

Abstract: A draw-works (10) is for maneuvering drilling devices that includes a winder (11) for winding at least one rope (12), which is centered on a shaft (13) having one first end and one second end and rotating in one first direction and in one second direction opposite to the first. The winder (11) is at least partially substantially cylindrical in shape. One or more supports (14) rotatably support the shaft (13). Motors (19) are designed to enable rotation in the first direction and in the second direction of the shaft (13) and of the winder (11). The supports (14) and the motors (19) are fixed to a frame base (16). The motors (19) are set on both sides of the winder (11) and connect to them without speed-reducing elements, with direct drive on the shaft (13).

Abstract: A method according to the invention of controlling a rotation speed of a motor of a speed-controllable hoist drive comprises receiving a lift speed instruction; forming a final speed instruction by using initial information containing the lift speed instruction; and using the final speed instruction as a speed instruction for the rotation speed of the motor of the speed-controllable hoist drive. The method further comprises monitoring a position derivative of an actual value of a cable force. The initial information for forming the final speed instruction comprises the position derivative of the actual value of the cable force.

Abstract: Two incremental shaft encoders are mounted on the two extreme ends of a mechanical drive train. The encoders generate data which is representative of the rotational speed of the drive train component proximate to where the encoder is mounted. The data from the encoders is communicated to a logic unit associated with operation of the drive train, such as a variable frequency motor drive (VFD). Software in the logic unit monitors and compares the speed of both encoders. An encoder resolution setting and a gear ratio are entered into the software parameters. If a difference in speeds (as monitored and indicated by the encoders) is greater than a preset value for a period longer than a preset time period, the logic unit displays an error message and a programmed action (such as motor shutdown and load braking) is executed.

Abstract: A task input is received at a well service rig. The maximum allowable speed is determined for the task. Current block speed inputs are received. The throttle position for the engine controlling the block is evaluated to determine if the block is to be sped up or slowed down. When the throttle position indicates the operator is attempting to speed up the block, the current block speed is compared to the maximum allowable speed and the engine is only allowed to speed up the block up to the maximum allowable speed, at which point the operators control of block speed is limited to reducing block speed. Each task can have multiple maximum allowable speeds, which can vary based on specified conditions. When the hookload is light or the remaining equipment in the well is small, the lock-up feature for the transmission can be disengaged in addition to the block speed governing feature.

Abstract: According to the present disclosure, a projector lift is provided to raise and lower a projector from the ceiling. The projector lift includes a first mount normally coupled to the ceiling, a second mount supporting the projector, a driver configured to raise and lower the second mount and projector, and a stabilizer extending between the first and second mounts.

Abstract: A balancer hoist has an electric servomotor driving irreversible gearing in turn driving a hoist chain drive. A float mode and a manual mode are provided using two independent load sensors for sensing the load weight and force applied to a control grip. A traversing control is produced by a tractor carriage rolling on an overhead rail connected to a trolley also traveling on the rail and supported on upper hoist assembly. A load sensor interconnects the tractor carriage and upon hoist assembly to sense forces created by an operator pulling on the chain, which are used to control an electric motor on the tractor carriage driving a pinion gear engaged with a gear rack on the overhead rail to positively drive the carriage, trolley and upper hoist assembly along the rail. A stationary dual hoist system is also described in which two hoist assemblies are interconnected by a chain and sprockets to provide synchronized operation.

Abstract: The technology disclosed herein provides a multiple sensor system that prevents crown incursion by a traveling block in an oil rig. This system calculates traveling block position, traveling block velocity and weight supported by the traveling block, and uses this information to calculate emergency stopping positions to prevent crown out by the traveling block. The system takes all these parameters into consideration when slowing and/or stopping the traveling block when it reaches a crown out position. The result is much safer operation of the traveling block on a workover rig, as well as on an oil drilling rig.

Abstract: A winch assembly (10) comprises a winch drum (18) rotatable about a first axis and carrying a spoolable medium, such as wireline (14) for use in deploying and retrieving tooling into and from a well bore. A carriage sheave (30) mounted on a drive screw (34) is positioned adjacent the winch drum (18), wherein the drive screw (34) is rotatable about a second axis substantially parallel to the first axis. In use, the carriage sheave (30) engages the spoolable medium and is translated by the drive screw (34) in reverse directions to follow the fleeting motion of the spoolable medium as the medium is paid out and/or in from the winch drum (18). In a disclosed embodiment, the winch drum (18) is mounted vertically on a tubular body (22), through which tubular body (22) the spoolable medium extends into the well bore. In one embodiment the winch assembly (10) forms part of a subsea well intervention system.

Abstract: A method for monitoring a chain pulley block and a chain pulley block apparatus with an electric actuator motor (2) that is connected at the drive side to a transmission (7) across a sliding clutch (14). In order to achieve a safe operation of the chain pulley block, the speed of the transmission (7) is determined via a sensor (18), the determined speed of the transmission (7) is compared in a control device (19) to the operating speed of the actuator motor (2) as determined from rated duty of the actuator motor (2) and if a deviation is found between the speed of the transmission (7) and the operating speed, allowing for tolerances and any transmission ratio of the transmission (7), the actuator motor (2) is switched off.

Abstract: A dual braking device for a power winch includes a first braking device and a second braking device, which is composed of a transmitting sleeve, a braking lining, an electromagnetic induction coil, a magnetic conduction member, and an elastic member. When the power winch is electrically connected for retracting or releasing steel ropes, the induction coil will produce magnetic force to attract the magnetic conductive member to move and compress the elastic member, and the braking lining cannot perform braking. When the power winch is electrically disconnected, the electromagnetic induction coil cannot produce magnetic force, and the magnetic conduction member will be actuated by the elastic member to contact with and force the braking lining to stop the rotating shaft and the spindle.

Abstract: A hoisting and pulling device has a frame body (13) made by integrally forming a speed reducer side frame (13b) on an outer peripheral edge surface of the frame body, a drive side frame (13a) on the outer peripheral edge surface of the frame body, and a frame connection section (16) on the outer periphery of a load sheave receiving section. The speed reducer side frame (13b) rotatably supports a speed reducer gear (3) and has a speed reducer side cover installation section (15b). The drive side frame (13a) has a drive side cover installation section (15a). The frame connection section (16) has guide grooves (22a, 22b) for guiding a chain (11) run around the load shave. Both frames (13a, 13b) have hook installation holes (24) for rotatably supporting a hook for suspending a body frame on the load side. The structure above reduces the number of parts and assembling man-hour and makes the structure simpler, reducing the size and costs.

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 power assisted winch and method include a control system and method for detecting the amount of turning force or torque supplied by a manual input drive to the winch drum, supplying turning force or torque from a motor to the winch drum and controlling the amount of torque supplied by the motor to the winch drum as a function of the amount of turning force or torque supplied by the manual drive. The function may be a fixed predetermined ratio or it may vary depending upon the level of turning force or torque supplied by the manual input drive. A torque sensor may be utilized to detect the level of input manual torque and control apparatus controls the amount of torque supplied by the motor to gearing or coupling driving the winch drum.

Abstract: Apparatus and methods for operating a winch system comprising a wire spooled onto a drum rotatably mounted to a shaft. A permanent magnet is mounted to the drum such that, when an electric current is applied to a coiled winding mounted to the shaft, the drum rotates about the shaft. The winch comprises a first braking system that controls the rotation of the drum about the shaft by controlling the application of the electric current to the coiled winding. The winch also comprises a second braking system that mechanically engages the drum so as to prevent the rotation of the drum about the shaft. The winch is used in conjunction with a control system that facilitates the use of the winch with lifting and supporting personnel working in elevated environments.

Abstract: A snow-trail grooming vehicle has a driving chain or track system and a cable assist pulling system having a cable winch. A method for controlling the cable winch includes the steps of detecting the speed of the driving chain, detecting the speed of the cable, comparing the detected speed of the driving chain and the detected speed of the cable, and determining a desired value for the speed of the cable, then controlling the cable winch to attain the desired value for the speed of the cable.

Abstract: An improved chain motor drive controller is provided for a chain hoist. The system employs a position encoder including a position sensor located within the casing of the chain hoist to producing encoded electrical position signals. A motor pulley is mounted on the chain motor rotary drive shaft and is coupled by a cogged belt to rotate an encoder pulley that is mounted on the same shaft as the position sensor. A mechanical coupling is thereby provided entirely within the casing of the chain hoist to transmit rotary motion from the rotary drive shaft directly to the position sensor. Also, tracking circuitry, likewise located entirely within the chain hoist casing, receives electrically encoded destination signals and compares these to signals from the position sensor.

Abstract: An improved chain motor drive controller is provided for a chain hoist. The system employs a position encoder including a position sensor located within the casing of the chain hoist to producing encoded electrical position signals. A motor pulley is mounted on the chain motor rotary drive shaft and is coupled by a cogged belt to rotate an encoder pulley that is mounted on the same shaft as the position sensor. A mechanical coupling is thereby provided entirely within the casing of the chain hoist to transmit rotary motion from the rotary drive shaft directly to the position sensor. Also, tracking circuitry, likewise located entirely within the chain hoist casing, receives electrically encoded destination signals and compares these to signals from the position sensor.

Abstract: A mobile service rig for wells includes a hoist powered by an internal combustion engine. In response to the hoist exerting a predetermined lifting force, the lifting force is limited by automatically limiting or reducing the speed of the engine.

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: The Escape-Right is an emergency escape system comprising: a passenger harness, a cable, a reel, a shaft fixed to the reel permitting rotation of the reel as the cable is unrolled, a reduction gear assembly, a centrifugal brake assembly, a housing enclosing the brake assembly, and a mounting mechanism. The escape right is a mechanism to escape or descend from the upper floors of a building when the usual exits are unavailable. The Escape-Right may be anchored to prepared points, heavy objects within the building, or a ladder placed near the exit portal. The braking mechanism may be attached to the anchor point or the user. In some configurations of the Escape-Right multiple descents may be accomplished without rewinding the cable.

Abstract: An apparatus and method for controlling the cable winch of a snow-trail vehicle by:

Abstract: In a hoisting device for an elevator, a driving motor is made cylindrical, and a brake system is accommodated radially inwardly of the driving motor. The driving motor and the brake system overlap in a radial direction.

Abstract: The present invention relates to a safety device for an air balancing hoist for braking and finally stopping a reel drum in such a manner that upon fast rotation of the reel drum during a lifting-up operation, a braking pawl attached to the reel drum is locked into a ratchet wheel secured on an end cap due to centrifugal force. The air balancing hoist includes a housing 102 with a chamber 101, which compressed air is introduced into and discharged from, formed therein and with end caps 104, 111 mounted on both ends of the housing, a piston 105 reciprocating along an inner periphery of the housing 102, a ball screw 106 installed in the housing 102 so that it penetrates the piston 105 and is secured to the end caps 104, 111 so as not to rotate, and a reel drum 110 with one end thereof rotatably supported by the piston 105 through a bearing 107 and with the other end thereof secured on a ball nut 108 rotatably engaged with the ball screw 106 so that the reel drum is rotated when moving along the ball screw 106.