Abstract: A work machine includes: an actuator that extends and retracts a telescopic boom; an electric drive source that is provided in the actuator and drives using power supplied from a power source; an operating unit that operates based on power of the electric drive source; and a joint that has a drive-side element fixed to a first transmission shaft that rotates on the basis of the power of the electric drive source and a driven-side element fixed to a second transmission shaft connected to the operating unit, the joint being able to take a transmission state in which both the drive-side element and the driven-side element rotate and a non-transmission state in which only either the drive-side element or the driven-side element rotates.

Abstract: A hydraulic actuator for a mobile crane, in particular for a locking device of a telescoping device. The hydraulic actuator has a double chamber cylinder with a first cylinder chamber and a second cylinder chamber oriented in an opposite direction to the first cylinder chamber, a first piston rod for the first cylinder chamber, and a second piston rod for the second cylinder chamber. A first restoring spring restores the first piston rod to its main position and a second restoring spring restores the second piston rod to its main position. The main position of the first piston rod is its pushed-in position and the main position of the second piston rod is its extended position.

Abstract: A telescoping jib of a mobile crane having a basic box and a plurality of inner boxes that can each be extended from a retraction position to an extension position and that can be locked and unlocked together in the respective retraction position or extension positions by means of bolting holes, which are arranged in the basic and inner boxes, and associated locking bolts. In order to provide a telescoping jib of a mobile crane which can be easily unlocked in an emergency, it is proposed that, in the retraction position of the basic and inner boxes, the bolting holes for the extension positions are aligned with one another.

Abstract: A locking device for a telescopic boom, in particular of a mobile crane, has an actuator for generating an actuating force, a driver that is reversibly coupled, during a telescoping movement of the telescopic boom, to a locking bolt, which is secured at a boom extension segment of the telescopic boom, and to be moved under the action of the actuating force for adjusting the locking bolt between at least one locking position and a release position. A driver bolt can be moved reversibly by the actuating force between a carry-along position gripping an inner boom extension segment and an empty running position not gripping a boom extension segment. A slotted actuating link is configured for a joint movement of the locking bolt and the driver bolt. A movement plane of the slotted actuating link is oriented perpendicularly to the telescoping direction of the telescopic boom.

Abstract: A telescoping jib system of a mobile crane having a basic telescoping jib and an additional telescoping jib that can be retracted and extended via a telescoping cylinder with a securing and locking unit. In order to improve the telescoping jib system, it is proposed that a securing unit is arranged on a tip of the telescoping cylinder, the securing unit comprises exclusively at least one driving bolt, via which an additional telescoping jib separate from the basic telescoping jib can be retracted into the basic telescoping jib. The invention also relates to a method for lengthening a basic telescoping jib of a mobile crane by means of an additional telescoping jib to form a telescoping jib system.

Abstract: There is provided a crane including: a telescopic boom having an inner boom element and an outer boom element; a telescoping actuator that displaces the inner boom element or the outer boom element in the telescoping direction; a first coupling member that releasably couples the telescoping actuator to one of the boom elements; a second coupling member that releasably couples the pair of boom elements to each other; an electric drive source provided at the telescoping actuator; a first coupling mechanism that displaces the first coupling member or the second coupling member on the basis of motive power of the electric drive source, thereby switching a coupled state and a non-coupled state of the members that are releasably coupled by one of the coupling members; and a position information detection device that detects information relating to the position of one of the coupling members on the basis of output from the electric drive source.

Abstract: A crane telescope locking device includes a control device which is hydraulically in contact with a telescoping cylinder of a crane telescope and, for the purpose of actuating, with at least one cylinder lock hydraulic cylinder and includes a valve which is open in its inactivated resting state and thus opens a fluidic connection between the telescoping cylinder and the at least one cylinder lock hydraulic cylinder. A telescoping cylinder (6) of a crane includes such a crane telescope locking device.

Abstract: Example aspects of a fenestration-lowering device and a method for using a fenestration-lowering device are disclosed. The fenestration-lowering device can include a frame; a support platform configured to move relative to the frame; and a hydraulic lowering mechanism configured to move the support platform. The method for using the fenestration-lowering device can include providing a hydraulic lowering mechanism for moving a support platform of the fenestration-lowering device from a raised orientation to a lowered orientation; setting a fenestration product on the support platform in the raised orientation; activating the hydraulic lowering mechanism to move the support platform from the raised orientation to the lowered orientation; and removing the fenestration product from the support platform.

Abstract: A pin actuator assembly for a telescoping boom includes a locking head having a base, an operating plate operably coupled to the base, one or more cylinder pins and/or one or more section lock arms movable in response to movement of the operating plate relative to the base. The pin actuator assembly also includes an actuator operably coupled to the operating plate and configured to move the operating plate relative to the base. The actuator includes an electric motor and a drive arm. The electric motor is configured to drive the drive arm between an extended drive arm position and a retracted drive arm position. The pin actuator assembly further includes a motion mitigator having a housing, a rod movable relative to the housing and operably coupled to the actuator, a first biasing member coupled between the rod and the housing and a second biasing member coupled between the rod and the housing.

Abstract: A crane, in particular a loading crane, includes an arm system that has a plurality of arms. The crane also has a crane controller that is configured, in a coordinate control operating mode, to control the coordinates of the arm system. The crane controller has a user interface, and the user interface has at least one function which can be selected by a user and by way of which at least one of the degrees of freedom of the arm system can be restricted or is restricted in the coordinate control operating mode.

Abstract: This crane is provided with: a telescopic boom that can be extended; an extension device for extending the telescopic boom; a hydraulic pressure source provided in the extension device; a cylinder connection mechanism connected to the hydraulic pressure source and switching between the states of connection and non-connection with the telescopic boom on the basis of the supply and discharge of hydraulic oil; a first oil path for connecting the hydraulic pressure source and the cylinder connection mechanism; a first valve that is provided on the first oil path and switches the supply and discharge state of the hydraulic oil with respect to the cylinder connection mechanism; and a second oil path that bypasses the first valve and connects the hydraulic pressure source and the cylinder connection mechanism.

Abstract: A drive system (46) for a telescoping boom (22) includes an elongated member (48), a locking head (50) configured to be driven on the elongated member, an actuator (52) configured to drive the locking head on the elongated member, and a cabling assembly (54) interconnected between the actuator and the locking head such that the locking head is driven on the elongated member in response to operation of the actuator, the cabling assembly including a cable (64) and a plurality of sheaves (66, 68). The telescoping boom includes a base section (34) and one or more telescoping sections (36, 38, 40) configured for telescoping movement relative to the base section, and the locking head is configured to selectively engage and disengage a telescoping section of the one or more telescoping sections.

Abstract: An expansion/contraction mechanism includes a telescopic cylinder, boom fixing means, cylinder-boom connecting means, and a hydraulic-pressure supply unit, and telescopes a plurality of booms except a base boom by telescoping the telescopic cylinder. The hydraulic-pressure supply unit includes a pneumatic-pressure source, a selector valve which selects a destination of air provided from the pneumatic-pressure source, a first pneumatic path through which first air sent from the selector valve circulates, a second pneumatic path through which second air sent from the selector valve circulates, a first pneumatic-to-hydraulic conversion unit which converts a pneumatic pressure provided by the first air to a hydraulic pressure and supplies the hydraulic pressure to a first hydraulic cylinder, and a second pneumatic-to-hydraulic conversion unit which converts a pneumatic pressure provided by the second air to a hydraulic pressure and supplies the hydraulic pressure to a second hydraulic cylinder.

Abstract: A drive of a sliding connecting member of a locking system of a telescopic system, having a telescopic cylinder (1) with an outer telescopic section (2, 3) and an inner telescopic section (6, 7), which are each provided with a locking hole (5) into which a locking bolt (11) can be entered and withdrawn in a releasable manner via the sliding connecting member (14), provided with a sliding path (12), and a grasper (10), wherein the locking bolt (11) is designed to be moveable by means of an engagement member (9) running in the sliding path (12) in such a way that the locking bolt (11) effects a linear movement and the jib sections (3, 6) can be connected to one another by insertion of the locking bolt (11) into the bolting hole (5) and the sliding connecting member (14) can be driven by an electric linear drive (4).

Abstract: The hoist comprises a crosspiece, an insertion portion, and two folding members. The insertion portion may be inserted into a receiver. The folding members are each positioned near opposite ends of the crosspiece and are pivotally coupled to the crosspiece such that each folding member may be pivoted upward and towards each other. The folding members may be lengthened and shortened. When in a folded position, the folding members are retracted and turned inward so that each folding member aligns parallel to the crosspiece. When in the extended working position, a chain is coupled to a top portion of a vertical extension member to the coupling member such that the folding members are in an upright, lifting position. A winch cable extending from the crosspiece and through a pulley positioned near the coupling member is adapted for lifting an object.

Abstract: When an extension pattern selection device is activated, a normal mode is displayed on a screen of a monitor. An operator presses a manual mode switch key of an operation unit to switch the display mode of the screen from the normal mode to an extension pattern manual rearrangement mode. In the extension pattern manual rearrangement mode, the operator rearranges extension patterns so that frequently selected extension patterns P may be displayed at upper positions. Thus, the frequently selected extension patterns P are more preferentially displayed than the other extension patterns P.

Abstract: A locking head is configured such that it can be moved within and along the longitudinal axis of a telescope, which comprises at least two telescope sections, by means of a telescoping device, comprising a base body, at least one releasing device which is configured to release a telescope section lock and at least one coupling device which is configured to couple a telescope section with the telescoping device. The locking head comprises an operating member which mechanically acts on the releasing device and the coupling device in order to operate the releasing device and the coupling device. The operating member comprises a first link guide for the releasing device and a second link guide for the coupling device, wherein the links for the first and second link guides extend in a single plane or in parallel planes.

Abstract: A device (10) and a method for locking a slewable arm of a machine (70), mountable on a vehicle (80). The device (10) comprises a foot (11), which can be securely connected to the vehicle: a slewing system (12), rotatable in relation to the foot, and drivable by a drive (20) to cause the machine to rotate; and locking means (30, 35) for locking the rotation of the slewing system (12) relative to the foot (11), wherein the locking means (30, 35) are independent of the drive (20).

Abstract: The invention relates to a traction rod (1) for bracing a crane jib, comprising a metallic tubular body (2) and coupling elements (3) which are connected to both ends thereof for an articulated connection of the traction rods among each other by means of bolts (5). According to the invention, the tubular body and the coupling elements consist of a one-piece tube portion, wherein the coupling elements are designed in each case as a thicker zone of the wall of the ends of the tubular body and are dimensioned in such a manner that a weakening of the cross section of the nominal wall thickness of the coupling elements, which has to be considered for calculating the load capacity of the tubular body, is prevented in the region of the bolt connection and the transition regions (7) from the respective thicker zones of the wall in the direction of the tubular body have a transition free of starting points for increasing fatigue strength.

Abstract: Since both a driving means for lifting a work and a driving means for turning operation must have been arranged in a conventional work transfer apparatus, the apparatus has been large in size and heavy in weight. A work transfer apparatus is provided with a holding tool for holding a window, i.e., the work, and a supporting arm for movably supporting the holding tool. The window held by the holding tool is transferred by a supporting arm to window frames to which the window is to be assembled, and the posture of the window is changed to that corresponds to the window frames. Furthermore, the supporting arm is configured to be a closed loop link mechanism wherein a plurality of links are connected to form a closed loop. The posture of the holding tool one link of a pair of links connected to the holding tool of the supporting arm can be fixed.

Abstract: An apparatus generally consisting of a base member mountable on a component of a prime mover which may be pivoted about a transverse axis, a carrier mounted on the base member displaceable along a transverse line of travel between first and second positions and a boom mounted on the carrier, disposable in an inoperative position disposed along such line of travel when the carrier is in its first position and pivotal to an operative position disposed at an angle relative to such line of travel when the carrier is in its second position.

Abstract: A hydraulically operated wedge lock system provides a releasable mechanical lock between telescoping boom segments. Each wedge lock mechanism includes a stationary backing wedge block that defines an angled smooth surface. A stationary shaft and piston is supported generally parallel to the backing wedge block. A slidable wedge block biased by a spring to a locked position is supported for reciprocal movement on the shaft along the angled smooth surface. Hydraulic fluid urges the slidable wedge block against the bias of the spring to an unlocked position.

Abstract: A crane having a telescoping boom whose sections, are arranged in a base boom that can telescope individually, in and out, after disengaging locking pin connections that are secured in the respective moved out or moved in positions by locking pins. A guide profile head is arranged at an end remote of the articulation of the safety locking unit to the inner end of the base boom. To lengthen the boom without substantially changing the telescopic system itself, the guide profile head is detachably fastened to the safety locking unit. An additional guide frame, whose length is dimensioned corresponding to the length of the telescoping boom that has been expanded by additional sections inserted in the telescoping boom, is mounted in place of the guide profile head, and that a guide profile head can be arranged at the free end of the guide frame.

Abstract: A crane jib system having a main jib, an auxiliary jib, and a telescoping cylinder. The main jib is comprised of main telescoping portions and the auxiliary jib is attached to the main jib and comprises auxiliary telescoping portions. The telescoping cylinder has a first telescopic part locking unit disposed on a base portion of the telescoping cylinder. The first telescopic locking unit is adapted to selectively engage the main telescoping portions. A second telescopic part locking unit is disposed on the telescoping cylinder above the first telescopic part locking unit. The second telescopic part locking unit is adapted to selectively engage the auxiliary telescoping portions.

Abstract: The crane includes a rotating part composed of a jib and of a counterjib, and a mechanism for slewing the rotating part that has at least one geared motor unit with a motor and reduction gear, and an internal main brake which is deactivated when the crane is placed out of service, in order to allow the rotating part to slew freely according to the direction of the wind. The geared motor unit also includes an internal auxiliary brake which is interposed between the motor and the reduction gear and which is activated when the crane is placed out of service in order to exert on the rotating part a braking torque which avoids uncontrolled rotation of said part when placed in weathervaning mode. The auxiliary brake can be designed to exert an adjustable braking torque.

Abstract: A boom assembly comprising: a base anchored to a structure/ground. A boom is rotatably mounted to the base at a connected end so as to be rotatable about a generally vertical axis, the boom having a device to support loads at a free end. An orientation clutch is provided between the base and the boom. The orientation clutch has a mechanism for locking a rotation of the boom with respect to the generally vertical axis so as to selectively adjust an orientation of the boom. The orientation clutch has a release configuration to allow the boom to self-adjust its orientation to align with a load pulled by the device.

Abstract: An all terrain vehicle having a vehicle frame with a boom frame attached to the vehicle frame, a saddle nest attached to the boom frame, a pivot saddle respectively secured to the boom frame, a telescoping boom secured in the pivot saddle, the pivot saddle comprising a post disposed adjacent and parallel to the telescoping boom, a locking sleeve slidably mounted on the post, and a latch formed on the vehicle frame with the locking sleeve and latch adapted to interlock to maintain the telescoping boom in an upright position.

Abstract: A locking and bolting unit for sections telescoping out of a basic element, in particular sections of a telescoping boom of a mobile crane. The invention involves a locking and bolting unit for sections telescoping out of a basic element, in particular sections of a telescoping boom of a mobile crane, comprising two safety bolts (3) arranged displaceably relative to each other, and an interlocking bolt (5) interacting with a grasper (4). Moreover, the safety bolts (3) and an extension of the grasper (4) constructed as a piston rod (5) are positioned together in a lower housing section vertically displaceable in relation to each other and the piston (6) for the piston rod (5) of the grasper (4) is located in an upper housing part (2) placed on a lower housing part (1).

Abstract: The invention relates to a controller for an adjustable jib extension of a mobile crane, comprising a telescoping main jib and a jib extension placed thereon, the luffing angle of the extension being adjustable by way of a luffing winch or a piston-cylinder unit. For this purpose, the actuation of the winch moving the luffer or of the piston-cylinder unit is carried out via a control circuit such that during the extension and/or retraction of the telescoping jib, or when changing the angle of the main jib with respect to the horizontal, the angle of the luffer with respect to the telescoping main jib and/or the horizontal remains constant or changes to a predefined extent.

Abstract: The invention relates to a locking system for a telescopic crane jib, in particular for a mobile crane, in which a lock is established between a telescoping cylinder (10, 20) and a telescopic part (1-4) by means of a locking unit (21) in order to extract and retract the telescopic parts, and the locking unit (21) is disposed on the telescoping cylinder (10, 20) in such a way that it can be moved longitudinally.

Abstract: An apparatus which enables the user to transition the location of a load contained within vessels or cavities which are accessed by means of a manhole, manway, or other similar openings which provides for limiting peripheral interference, the establishment of a high center point in both horizontal and vertical applications, and limiting the weight and bulk of such an apparatus.

Abstract: An improvement for a railroad tie crane utilizes a movable stop mounted on an elongated member between a pair of cushioned terminals to reduce impact stress on equipment and personnel in situations where the tie crane must be prevented from fouling an adjacent track. The movable stop is selectively engaged by a retractable bar mounted on the rotatable platform carrying the crane boom.

Abstract: The invention relates to a crane (10) for handling of chains, wires, shackles, messengers, etc., onboard a vessel, where one or more cranes (10) is arranged on or adjoining the deck of the vessel, and where each crane comprises a base part (12) with an associated main jib (14) that is arranged to be driven by a number of pressure cylinders (26). At least two rotary work jibs (16,18) arranged to be driven separately by associated pressure cylinders (28,30) are arranged to the outwardly extending end (15) of the main jib (14), and tools (34,22,24) are arranged to the outwardly extending ends (17,19) of said work jibs (16,18), for the mutual handling of said chains, wires, shackles, messengers, etc.

Abstract: Embodiments of a recoverably installable portable lift are disclosed. A novel feature of the present invention is the ability to retract to a stored position that does not interfere with other features or functions of the host apparatus. The disclosed invention further mitigates the need for disassembly between uses.

Abstract: Boom of a laying mechanism of a bridge laying vehicle, the laying mechanism being composed of a placement arm and the boom. The boom includes a base member that can be fixedly secured to the vehicle by at least one securement device. A jib, especially with locking elements for locking a bridge element in place, is moveable relative to the base member. A pivot member is pivotably disposed on the base member, and the jib is pivotably disposed on the pivot member. Pursuant to the method for moving the boom into a vehicle transport position, the jib is pivoted about a pivot axis in the forward direction of travel by raising the pivot axis of the jib.

Abstract: A foldable portable hoist system includes a foldable portable hoist assembly and a mounting base. The foldable portable hoist assembly includes a substantially vertical support, an upper support arm, and a diagonal brace assembly. Hinged attachment of slidable collars on either end of the diagonal brace enables the foldable portable hoist assembly to be folded up for ease of transport and storage.

Abstract: A crane has a boom with a boom segment connection system. The boom includes at least a first and second boom segment each with a longitudinal axis and a first and second end, the second end of the first segment being coupled to the first end of the second segment, and at least one first connector on the second end of the first segment respectively mating with at least one second connector on the first end of the second segment. The first and second connectors each include at least one extension having an aperture there through. The aperture has an axis perpendicular to the longitudinal axis and positioned in the extensions such that all apertures of mating first and second connectors are aligned when the boom segments are aligned.

Abstract: Boom uplock arrangement for a loader, said loader comprising a least one movable boom arm (20) and a support means (70), wherein the boom arm (20) is provided with a horizontal, transversal through going hole (21), and a locking pin (42) movably arranged in the hole (21), the locking pin (42) is elongated, and having a first (421) and a second (422) end the locking pin (42) is movable in its longitudinal direction between a passive and an active position; wherein the passive position of the locking pin (42) enables movement of the boom arm (20) past the support means (70), and the active position of the locking pin (42) prevents movement of the boom arm (20) past the support means (70). The invention is characterized in that the locking pin (42) is provided with a protruding manoeuvre stick (48) arranged in the vicinity of the first end (421) of the locking pin (42), enabling manoeuvring of the locking pin (42) between the passive and active positions.

Abstract: A hoist for retrieving, lifting and positioning a light load of up to about 1000 lbs, is described. The hoist comprises a boom support column having an attaching lower end and a boom support upper end. The boom support upper end has a boom assembly connector and a transverse support surface. The boom assembly has a connecting support wall and a lower projecting connector for rotational connection with the boom assembly connector for maintaining the boom at an upward angular position. A releasable locking mechanism locks the boom at the upward angular position. A boom actuating brake arrests rotational displacement between the connecting support wall and the transverse support surface when the boom is at a substantially horizontal load retrieving position. A pulley is rotatably secured to an axle secured at a free end of the boom. The pulley is adapted to guide a cable thereon through a cable guide linkage to align and maintain the cable on the pulley.

Abstract: A mobile hydraulic hoist unit which is readily maneuverable to a position straddling a load and then conveniently operated to lift and securely transport such load over a variety of terrains and surfaces and to safely and accurately deposit that load at a specific location. The hoist unit comprises a generally “U” shaped base frame having spaced side members provided with multi-terrain wheel assemblies, a closed forward end having a hitch member for releasable attachment to a towing vehicle, a rearwardly open center section adapted to receive and straddle the load, a power cylinder, a boom operated by the power cylinder for lifting and securely holding the load in a transport position during movement of the hoist unit and for accurately depositing the load at the desired destination.

Abstract: The device applies to a crane having multiple functions, with a modifiable configuration, which comprises a foldable mast, composed of two elements, and a distributing jib, composed of a plurality of successive elements. This device comprises a double-acting jack connecting a lower rod assembly to an upper rod assembly. The lower rod assembly is connected to the lower part of the upper mast element and to the upper part of the lower mast element. The upper rod assembly is connected to the upper part of the upper mast element and to the jib foot.

Abstract: A locking and latching system for use with a telescoping boom assembly in a crane or other lifting device is provided. The system may include complementary devices for latching and unlocking a selected boom section for telescoping movement relative to a next-adjacent boom section using an extension cylinder. Preferably, the devices are activated in a predetermined sequence using a single motive device. The motive device may include a single cylinder for performing both the locking and latching function. The locking and latching cylinder may be axially aligned with the extension cylinder to create a relatively compact locking and latching system that easily fits within the confines of the innermost boom section in a conventional boom assembly.

Abstract: A digger derrick truck for installing poles into the ground. The digger derrick truck includes a boom on which a pole guide assembly is slidably mounted. The pole guide assembly is operatively associated with a latching mechanism which releasably couples the pole guide assembly and the boom in an operative position and an inoperative position. The latching mechanism includes a latch arm and a release mechanism such that, when the boom is retracted, the release mechanism allows the latch arm to pivot and couple the pole guide assembly and the boom.

Abstract: A locking unit for a telescopic system of a hydraulically actuated telescopic jib of a crane, having a jib box frame and a plurality of telescopic sections which are guided inside one another and can be moved out of a starting position into in each case at least one extended position is provided with a drive for moving at least one driver bolt of a locking unit into and out of a section receptive driver bolt opening, and for moving a coupling device for displacement of at least one locking bolt into and out of a locking bolt receptive opening, the drive being arranged fixedly on the box frame of the jib, there being a mechanical drive connection between the drive and the locking unit.

Abstract: A multi-sectioned, telescopically extending column. This invention includes an extension mechanism to extend the column and support the column sections during extension, and a locking mechanism to lock each column section to the next when the column reaches its extended position. The column is particularly well suited for use as a crane boom, where individual boom sections are nearly fully extended each from within the other to minimize overlap between adjacent sections and reduce dead weight resulting from such overlap.

Abstract: A locking and latching system for use with a telescoping boom assembly in a crane or other lifting device is provided. The system may include complementary devices for latching and unlocking a selected boom section for telescoping movement relative to a next-adjacent boom section using an extension cylinder. Preferably, the devices are activated in a predetermined sequence using a single motive device. The motive device may include a single cylinder for performing both the locking and latching function. The locking and latching cylinder may be axially aligned with the extension cylinder to create a relatively compact locking and latching system that easily fits within the confines of the innermost boom section in a conventional boom assembly.

Abstract: Segments can be telescoped out of the base boom with boom guides of a telescopic boom of a crane, which in either their extended or retracted positions are locked by locking pins. After releasing the locking pin connections, the segments can be moved in and out with a single-stage hydraulic piston-cylinder unit, one end of which is attached to the boom guide through two strokes so that each segment to be moved in or out is coupled either to the inside or the outside end area of the movable part of the piston-cylinder unit. In order to obtain a simpler structure, a movable ring or a movable pipe with a coupling device to couple the segments is placed on the cylinder by the piston rod fastened to the boom guide piece, which can be locked to either the internal or the external end area of the cylinder.

Abstract: A locking mechanism for telescoping sections, in particular for a mobile crane boom, includes a linearly shiftable locking bolt for connecting and releasing an inner telescoping section with respect to an outer telescoping section, said locking bolt being maintain ed biased in its extended position. The locking bolt is shifted by means of a rotary actuator from its extended position into its retracted position.

Abstract: The invention relates an apparatus for hoisting and handling equipment wherein the apparatus includes locking members having a locking block (30) carried by each telescopic element and including clamping member which is clamped in a rest position, an immobilization piece (40) carried by each element outside the element carrying a block configured to cooperate with the clamping member.

Abstract: A locking unit for a telescopic system of a hydraulically actuated telescopic jib of a crane, having a jib box frame and a plurality of telescopic sections which are guided inside one another and can be moved out of a starting position into in each case at least one extended position is provided with a drive for moving at least one driver bolt of a locking unit into and out of a section receptive driver bolt opening, and for moving a coupling device for displacement of at least one locking bolt into and out of a locking bolt receptive opening, the drive being arranged fixedly on the box frame of the jib, there being a mechanical drive connection between the drive and the locking unit.