Abstract: Techniques facilitating increased operational reliability for jib cranes are provided. In one example, a jib crane can comprise a mast, a shaft mechanism, and a rod. The mast can extend vertically from a base structure. The shaft mechanism can be disposed within the mast. The rod can be coupled to a boom arm and can be disposed within the shaft mechanism. Rotation of the rod can facilitate continuous rotation of the boom arm about a longitudinal axis of the rod with respect to the base structure.

Abstract: A center pintle hub to be affixed to a base of a machine. The center pintle hub includes a base portion and a support portion. The base portion is formed to be affixed to the base. The support portion extends from the base portion and has a frusto-conical shape that can receive a center pintle shaft. The center pintle shaft can support a frame of the machine and provide rotation of the frame with respect to the base.

Abstract: A portable davit includes a base having a mounting portion and a housing. The housing defines a cavity. An end of a mast is positioned within the cavity. A jib is coupled to another end of the mast. A connector is coupled to the jib. A hoist is coupled to a platform and includes a drive and a rope. An end of the rope is wound about the drive. Another end of the rope is coupled to the connector. The drive is configured to rotate relative to the platform in a first direction to decrease a distance between the platform and an end of the jib and to rotate relative to the platform in an opposite second direction to increase the distance between the platform and an end of the jib. Systems and methods of use are provided.

Abstract: A jib crane assembly having a vertical pole and a boom for lifting a load. The pole has a length and cylindrical outer surface. A pivot structure is arranged at an upper segment of the pole such that the boom is rotatably secured at a pivot point, thereby dividing the boom into first and second portions. A compression support extends from the first portion of the boom to a compression roller engagement assembly, and a tension roller engagement assembly is secured to the second portion of the boom, opposite the compression roller assembly. The tension roller assembly is attached to a tension frame, wherein said compression support, compression roller assembly, tension frame, and second portion of the boom provide structural support and counter-balance when lifting the load, and the pivot structure and roller assemblies facilitate rotation of the load around the pole.

Abstract: The invention provides a loader having a boom, a hydraulic motor, a slewing ring, and a boom swing control assembly. The boom is configured to rotate in response to operation of the hydraulic motor. The boom swing control assembly comprises a control gear, a first valve, and a first hydraulic line. The control gear is engaged with a slew gear of the slewing ring such that the control gear rotates in response to rotation of the boom. The hydraulic line is in fluid communication with the first valve and the hydraulic motor. Depending on whether the first valve is in an open or a closed configuration, hydraulic fluid is either free to pass, or is restrained from passing, through the first hydraulic line to the hydraulic motor.

Abstract: A crane includes a base, an upperstructure rotationally mounted on the base, a boom, and a gantry. The boom is pivotally attached to the upperstructure at a front attachment location and supports a load line operable to raise a payload. The gantry is mounted on the upperstructure and supports a boom line coupled to the boom. The gantry includes at least one front leg mechanically coupled to the front attachment location and inclined away from the boom to apply, to the front attachment location, a horizontal force component towards the boom opposed by a horizontal force component applied by the boom towards the front leg. The upperstructure includes a frustoconical turret forming an upper circle and a lower circle. The front attachment location is aligned over the upper circle of the frustoconical turret.

Abstract: The invention relates to a mobile crane having an undercarriage and a superstructure rotatable with respect to the undercarriage about an axis of rotation and having a ballast receiving apparatus arranged at the superstructure and having at least one ballasting cylinder for receiving ballast. In accordance with the invention, the position of the ballasting cylinders receiving the ballast is varied in the ballast receiving apparatus such that the ballast can be received in positions of different distances from the axis of rotation of the superstructure.

Abstract: A track-supporting roller assembly, according to the disclosure, for supporting a crawler track of a crawler chassis includes a bearing unit and a track-supporting roller rotatably coupled to the bearing unit. The track-supporting roller includes at least one supporting body made of plastic. The supporting body serves as a damper and prevents a metal-on-metal contact between track chain links of the crawler track and the track-supporting roller. The track-supporting roller assembly according to the disclosure ensures a reduced noise development in the crawler chassis. At the same time, it is possible to also reduce the wear of the track-supporting rollers to a considerable extent.

Abstract: A loading/unloading apparatus includes a cage configured to accommodate an electric appliance stored or to be stored in one of storage compartments provided within a cubicle; and a hoist configured to vertically move and hang the cage. The hoist includes a boom arranged on the cubicle to extend above the storage compartments and a hoisting winch attached to the boom. The cage includes a frame body provided with a seat for supporting the electric appliance, and a connector unit connected to the hoisting winch.

Abstract: A crane includes i) a lower structure comprising ground engaging members ii) an upper structure rotatably connected to the lower structure such that the upper structure can swing with respect to the lower structure, wherein one of the lower structure and upper structure comprises a first structure having a ring gear having teeth on a surface thereof, and the other of the lower structure and upper structure comprises a second structure; and iii) a boom pivotally mounted on the upper structure. The crane further includes a drive system comprising at least two pinion gears mounted on a common frame and in driving contact with the ring gear teeth; and a link connecting the frame to the second structure with two pivot axes between the frame and the second structure.

Abstract: A ring derrick includes a carriage which moves on a fixed circular track around a stationary counterweight. A tension and compression column assembled from transportable tubular segments is affixed to the counterweight by a universal swivel joint. The back mast of the derrick is secured at its upper end to the tension column, while the main boom of the derrick extends radially away from the tension column. The main boom and back mast are hinged directly together at the carriage by massive hinge pins which pass through spherical bearings mounted on the carriage. The carriage's suspension distributes the load from the boom and mast to an array of trucks and has an automatic stabilizing system that compensates for uneven track.

Abstract: This invention relates to a hoisting crane comprising a column, a jib and a jib connection member which is disposed on the column and to which the jib is connected pivotably. The crane further comprises an annular bearing structure extending around the column guiding and carrying the jib connection member rotatable about the column. The annular bearing structure comprises one or more column bearing parts connected to the column, comprising column bearing surfaces associated with the vertical column and one or more jib bearing parts connected to the jib connection member, comprising jib bearing surfaces associated with the jib connection member. A first column bearing surface is oriented substantially vertically and is arranged in a radial direction more inwards than a first jib bearing surface arranged opposite the first column bearing surfaces, to support radially inwards directed horizontal loads from the jib connection member to the column.

Abstract: A slewing actuator system for rotating a boom structure comprises a cylindrical support member having lower and upper ends; a drive mounting member; gearing means comprising a gear assembly and at least one gear drive fixable to the drive mounting member and operatively connected to the gear assembly; and a boom support means to releasably secure the boom structure and operatively connectable to the gearing means. In an operating position, the boom support means is mounted proximate the upper end of the cylindrical support member and is rotatable about a substantially vertical axis; the gear assembly is substantially horizontal; and the gearing means imparts rotational movement to the boom support means. The system can include a pedestal surrounding at least part of the cylindrical support member, which can be a tube or kingpin. The compact modular system can be secured to various surfaces including ship decks and land surfaces.

Abstract: The present invention, in one embodiment, is a system for receiving and delivering into a base the radial loads imposed on a crane where the crane has a center post operably connected to the base with a generally cylindrical outer bearing surface and the crane rotates in at least a partial circle around the axis of the center post. The system comprises three or more radial load rollers arranged in a linked sequence in an arc at the outer bearing surface of the center post. Each radial load roller includes an axle and an axis of rotation that is generally parallel to the axis of the center post. The system also comprises a means for anchoring a first radial load roller at one end of the arc and anchoring a second radial load roller at the other end of the arc. The system also comprises links connecting each roller between the first and the second radial rollers to its adjacent rollers to form a flexible chain of said rollers.

Abstract: The present disclosure relates to a lifting assembly such as a jib crane or similar apparatus having an articulated arm assembly and a flexible means for connecting a load to an actuator. The lift arm assembly forms an articulated cantilever boom, which is extensible so as to traverse a suspended load within a work cell area. The lift arm assembly further includes a first and second member pivotally connected to one another whereby an inclined plane (e.g., a cam) at the pivot point of the articulating arms provides a vertical displacement of the secondary arms thereby moving the distal end of the secondary arm to counterbalance inherent forces acting thereon.

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: The present disclosure relates to a rotary joint for rotatable connection of the uppercarriage with the undercarriage of a crane, wherein they can each be connected with the uppercarriage on the one hand and the undercarriage on the other hand via a quick-release coupling.

Abstract: This invention relates to a hoisting crane comprising a column, a jib and a jib connection member which is disposed on the column and to which the jib is connected pivotably. The crane further comprises an annular bearing structure extending around the column guiding and carrying the jib connection member rotatable about the column. The annular bearing structure comprises one or more column bearing parts connected to the column, comprising column bearing surfaces associated with the vertical column and one or more jib bearing parts connected to the jib connection member, comprising jib bearing surfaces associated with the jib connection member. A first column bearing surface is oriented substantially vertically and is arranged in a radial direction more inwards than a first jib bearing surface arranged opposite the first column bearing surfaces, to support radially inwards directed horizontal loads from the jib connection member to the column.

Abstract: The invention relates to the bearing system of a luffing cylinder (1) of a crane, in particular a mobile crane, and the luffing cylinder (1) is connected to a bearing point on the crane by at least one of its ends by means of a spherical calotte-shaped bearing (2, 3).

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: At an inner circumference side of a lower ring and an upper ring, flange pars are formed respectively, and a ring-shaped clamp device is arranged at the inner circumference side, and separated at four points, into a front side, back side, left side, and right side, and divided into four divided clamps. At the separation points of front and back sides, the left and right divided clamps are rotatably connected with each other, and at the separation points of left and right sides, the front and back divided clamps are connected to cylinders respectively. By the extension/contraction operation, the front and back clamps move between joint and separation positions, and if the front and back clamps position at the joint points, predetermined spaces are formed between the divided clamps. Lock blocks to be inserted into the spaces for regulating return of the divided clamps to the separation positions are provided.

Abstract: A construction machine includes a vertical separating/connecting device interposed between a lower traveling body and a swing bearing that supports an upper rotating body. The device includes an externally toothed ring member fixed to the swing bearing with a first attaching unit, a rotating unit that rotates the externally toothed ring member, an internally toothed ring member fixed to the lower traveling body with a second attaching unit positioned on an attachment pitch circle having the same diameter and center as an attachment pitch circle of the first attaching unit, and a fixing unit that fixes the externally toothed ring member or the internally toothed ring member. Internal teeth of the internally toothed ring member and external teeth of the externally toothed ring member are positioned so as to allow the movement of the external teeth or to engage with each other when the externally toothed ring member is rotated.

Abstract: This invention relates to a hoisting crane comprising a jib, a jib connection member which is disposed on the column and to which the jib is connected pivotably. The crane further comprises an annular bearing structure extending around the column guiding and carrying the jib connection member rotatable about the column. The annular bearing structure comprises one or more column bearing parts comprising column bearing surfaces associated with the vertical column and one or more jib bearing parts comprising jib bearing surfaces associated with the jib connection member, whereby the column bearing surfaces and the jib bearing surfaces are arranged opposite from each other. A first column bearing surface is oriented substantially vertically and is arranged in a radial direction more inwards than the opposed first jib bearing surface, to support radially inwards directed horizontal loads from the jib connection member to the column.

Abstract: The present invention is a rotatable work machine that includes a lower frame assembly having a recessed area in which the operator portion of an upper frame assembly and power source are at least partially positioned. Further, a method of manufacturing and assembling the lower frame assembly enables various size configurations for the work machine. The method of manufacturing and assembling the work machine, along with the specific design and positioning of the various components therein, enhances stability, clearance, and operator visibility with reduced costs and complexity.

Abstract: A hoist system can be used to raise articles. The hoist system can include a mounting structure attachable to a billboard structure, a pole member fastenable to a mounting structure and a winch assembly. The winch assembly has at least one component coupled to the pole. The winch assembly is capable of winding a flexible line. The hoist system can be utilized to raise and lower vinyls, other signage equipment or tools to billboard structures. The pole can be a single piece unit having a bend.

Abstract: An upper bearing assembly for a pedestal crane comprises a partially dome-shaped kingpost head operably engaged by a bearing having a concave bearing face shaped to conform to a segment of said kingpost head, the bearing enclosed within a bearing retainer, the bearing retainer attached to the crane upper works.

Abstract: The invention relates to a device dedicated for slewing a crane column, which device comprises a fastenable crane base formed by a house which is open at the top and at the bottom and in which a lower tubular part of the crane column is rotatably journalled by means of a number of bearings, which have the abilities of absorbing the bending moment as well as the axial and-/or transversal forces. A power source is connected to the crane column via a power slewing in order to provide for a powered rotation of the crane column around a vertical axis of rotation. Characterizing for the invention is that the power transmission comprises an eccentric gear, which is integrated with the house by being seated in an annular space between the outside of the crane column and the inside of the house.

Abstract: A construction machine where an operating load is transferred to a location having good rigidity, thereby ensuring the strength of a vehicle body and increasing the load-withstanding strength in relation to running loads. The frame of the lower traveling body of the construction machine comprising a hollow center frame having an upper plate with an attachment ring, a lower plate, and side plates that surrounding sides of the frame and that jut out from the attachment ring, and reinforcing ribs which connect the upper plate to the lower plate in the interior of the center frame beneath the attachment ring.

Abstract: A construction machine where a load acting on a vehicle body during an operation is transferred to ensure the strength of the vehicle body, thereby improving reliability including welding reliability. In the construction machine, at least one of the height differences between an upper face or a lower face of the center frame at a joining portion between the center frame and the connecting member and an upper face or a lower face of a center joining portion of the connecting member is set respectively at a dimension that is approximately equal to or less than the thickness of an upper face plate or a lower face plate of the center frame.

Abstract: A crane mount assembly having a mounting base and tower, the base having a pair of longitudinal members in parallel spaced alignment with transverse members positioned therebetween, and a top and bottom plate secured between the longitudinal members and the transverse members to create a torsion cell. The tower includes a base plate with a plurality of side panels that extend vertically from the base plate, and a mounting plate that is secured to the top of the side panels to create a hollow chamber.

Abstract: A hoist system can be used to raise articles. The hoist system can include a composite pole member having a bend, a mounting structure attachable to the composite pole member and a winch assembly. The winch assembly has at least one component attached to the pole. The winch assembly is capable of winding a flexible line. The hoist system can be utilized to raise and lower vinyls, other signage equipment or tools to billboard structures. The composite pole can be a single piece unit having a bend.

Abstract: The present invention discloses a portable crane having an elongated boom which attaches at one end to a lower end of a base frame member wherein the upper end of the boom has a stabilizer member attached thereto which stabilizer attached to the upper end of the base frame member. The base frame member is pivotally attached using removable clamps to an upstanding member, for example, a door frame. The boom has a roller pulley attached to its upper end over which a line passes and a means for a motor having a winch mounted thereon attached to the lower end of the boom so that the user can attached one end of the rope to an object to be lifted and run the other end of the rope over the windlass so as to provide a hoist means to lift the object. The crane of the present invention is portable in that it can be moved from one frame member to another frame member so that it can be used at multiple locations internal a building.

Abstract: The present invention, in one embodiment, is a system for receiving and delivering into a base the radial loads imposed on a crane where the crane has a center post operably connected to the base with a generally cylindrical outer bearing surface and the crane rotates in at least a partial circle around the axis of the center post. The system comprises three or more radial load rollers arranged in a linked sequence in an arc at the outer bearing surface of the center post. Each radial load roller includes an axle and an axis of rotation that is generally parallel to the axis of the center post. The system also comprises a means for anchoring a first radial load roller at one end of the arc and anchoring a second radial load roller at the other end of the arc. The system also comprises links connecting each roller between the first and the second radial rollers to its adjacent rollers to form a flexible chain of said rollers.

Abstract: The foregoing invention concerns a rotary crane, especially an offshore crane of the king post type. The rotary crane has a pylon that can be permanently anchored on a floor plate, platform, or similar equipment, a turntable mounted to revolve on the longitudinal axis of the pylon, and rotating gear for rotating the turntable on the pylon, the rotating gear having a ring gear positioned on the pylon and a pinion drive that is connected with the turntable and meshes with the ring gear. According to the invention, the pinion drive is mounted on the turntable so that it can move radially relative to the ring gear, and is linked with the ring gear by means of coupling equipment. Tipping movements of the turntable relative to the pylon as a consequence of support clearance can thereby be equalized, and damage to the rotating gear can be prevented. Preferably the ring gear is multi-sectional and consists of several toothed segments attached to the pylon in such manner that they can be detached.

Abstract: The present invention concerns a turntable of a rotary crane of the king post type having a pylon anchored to a base plate, platform, or similar base. The turntable has a support frame that can slide above and is suspended from the pylon, coupling devices connected to the support frame to permit the coupling of a crane boom, and support devices to allow the support frame to revolve around the longitudinal axis of the pylon. The support devices have an upper support for the suspension of the support frame on an upper end section of the pylon, and a lower support for the suspension of the support frame on a lower section of the pylon, with the lower support having a bearing journal that encircles the pylon. According to the invention, the bearing journal of the lower support is designed to be divided. The support frame has an open longitudinal side through which the support frame with divided bearing journal can slide radially along the pylon.

Abstract: This invention concerns a rotary crane, especially an offshore crane of the king post type. The rotary crane has a pylon which can be anchored on a floor plate, platform, or similar equipment, a turntable housed to revolve around the longitudinal axis of the pylon by means of an upper support and a lower support, a crane boom supported by the turntable, and rotating gear for rotating the turntable around the pylon. The upper support has a mount which is positioned on the peak of the pylon and which can rotate, which mount has an axial support surface for axial support on the pylon as well as a radial support surface for radial support on the pylon, and suspension equipment for suspending the turntable.

Abstract: A mounting of the bottom bearing ring of a rotating deck or a truck of a crane on a mast comprises bearing slides, which are spaced apart and connected to the inside of the bearing ring and which support the bearing bodies, which are made of a high quality sliding material and are braced against an annular peripheral surface of the mast. Each bearing slide comprises a steel plate with a flat rearside, whose entire area rests without tilting against a flat support surface of the bearing ring, and that the bearing slide is connected to the ring so as not to rotate or move.

Abstract: A rotatably mounted ring having external teeth which mesh with a drive pinion of a fixedly mounted slewing gear, has distributed over the circumference, alternately portions of the same length with recesses and portions of the same length with radially directed webs and can be coupled to a complementary ring in the manner of a bayonet fastening. The complementary ring has, both on the inside and on the outside, portions of the same length with recesses and portions of the same length with radially directed webs. The ring provided with the external toothing is provided with complementary recesses and webs.

Abstract: An inverted pedestal crane has a base mountable to an underside of a horizontal support structure, such as for example a rig floor. A crane pedestal extends downwardly from the base, and a boom connects pivotally to the pedestal. The pedestal and the crane base rotate about a vertical axis, while the boom moves pivotally in relation to the pedestal. The crane has one main and a pair of auxiliary hydraulic rams for moving the boom during load handling operations. A robust slew bearing assembly mounted above the crane pedestal allows rotation of the base and the pedestal. The slew bearing assembly has a pair of parallel plates, a plurality of centering rollers and a plurality of stabilizing rollers mounted adjacent to an outer circumference of the parallel plates, between the plates. A winch assembly is mounted on top of the base, the winch assembly carrying a cable that extends over a pulley secured to a free end of the boom.

Abstract: A crawler traveling type working machine, comprising: a lower traveling body provided with crawlers on left and right sides; an upper rotating body mounted on the lower traveling body through a rotating means, the upper rotating body having a first counter weight; and a second counter weight interposed between an upper part of the lower traveling body and the rotating means. With this constitution, the stability of the working machine is excellent, the obstacle avoiding function when the upper rotating body rotates is excellent, and the rear rotating radius is smaller than the normal working machine of an upper class. Therefore, the working machine can be used as a working machine of an upper class.

Abstract: A seismic isolation system is provided with a swing bearing ring consisting of an upper ring and a lower ring, which are rotatable relatively, between a crane body and a traveling means. A lower vertical shaft of a block pivotally supported on saddles of the crane body is supported by a swing bearing provided at an eccentric position on the upper ring. An automatic restoring mechanism is provided which restores the swing of a horizontal lever, whose proximal end is installed to the upper ring of the swing bearing ring, around the centerline C2.

Abstract: An excavator undercarriage frame is made to reduce the amount of machining necessary for supporting a swing bearing and ring gear on which an upper swing platform including the cab and operator's platform are mounted. The frame is made in two separate frame sections having top plates and formed peripheral skirts that nest together to form a planar support on which the base ring of a swing bearing and ring gear are mounted. The frame section plates are thin enough so that they will flex to conform to the base ring of the swing bearing, so it is not necessary to provide a machined surface for the swing bearing. The frame sections are welded together only around the peripheral edges and skirts, so that the distortion in the plates is substantially eliminated.

Abstract: Disclosed is a novel jib crane for panel trucks, or vans wherein the crane pivots along a common axis between opposing fixed bearing mounts. In practice, one attaches a lifting apparatus ratus to a trolley of the jib. A payload is hoisted off the floor of the vehicle, and after pulling the locking pin, the jib/mast is manually rotated until the payload is clear of the vehicle. The payload is then lowered to the ground.

Abstract: A swing lock mechanism for machines having an upper works rotatably mounted on a lower works by a swing bearing is connected to the drive shaft of a swing bearing drive assembly and comprises a swing lock plate, an annular pin support, and a plurality of locking pins. The swing lock plate is affixed to the drive shaft and has at least one hole disposed about the axis of the drive shaft. The annular pin support is fixed against rotation relative to the drive shaft is disposed about the axis of the drive shaft. The locking pins are supported by the annular pin support and are also disposed about the axis of the drive shaft. The locking pins are arranged in such a manner so as at least one pin may engage a hole in the swing lock plate irrespective of the angular orientation of the swing lock plate relative to the annular pin support.

Abstract: A gantry lift includes one or more pairs of vertically extendible lift columns and one or more horizontal lift beams supported across the upper ends of the lift columns. The lift beams are supported on header plates that permit slight pivoting or rocking motion between the lift beams and the lift columns. This helps counteract potentially destructive twisting or other forces that can result as the gantry operates and slight misalignments unavoidably occur. A half bearing between the header plate and the upper end of the lift column supports the weight of the lift beam and load and provides the desired pivoting action. The header plate and half bearing are secured to the top of the lift column by means of a full bearing positioned within the half bearing and secured to the lift column by a bolt or other fastener. Both the half bearing and the full bearing pivot around a common center.

Abstract: A hoist for raising and lowering objects may be attached to a vehicle. The hoist includes a support column and a boom attached thereto; the boom can be raised and lowered by a hydraulic double action cylinder or otherwise. Both the support column and cylinder attach to a bracket, the bracket in turn being rotatably connected to a base unit so that the boom can be rotated as well as raised and lowered. The support column and boom can be adjusted with respect to one another and to the bracket, to balance loads and to adjust the reach of the hoist. Critical sections of the hoist, such as the portion of the boom that attaches to the support column, are reinforced with plates welded to the exterior of a rectangular tube. The connection between the support column and the bracket includes a nut to tension the column to the bracket. The base unit includes outriggers to support and stabilize the hoist, preferably three outriggers in a triangular configuration.

Abstract: A movable pedestal or kingpost type luffing crane that includes an upperworks, having a crane boom, rotatably mounted on a crane support. The crane support extends below the upperworks. The movable crane is constructed to be selectively maintained in or removed from a receiving socket. Movement prevention means prevents the radial and vertical movement of the crane support in the receiving socket. Anti-rotation means prevents the rotation of the crane support in the receiving socket. A centering means is also provided which facilitates the centering of the crane support means within the receiving socket. Providing a plurality of receiving sockets located at predetermined locations provides a system wherein the movable crane may be moved from socket to socket and from location to location.

Abstract: A roll bar and crane device for use with vehicles such as a truck is adapted to be mounted to the truck bed. The device includes left and right leg members and a central beam extending therebetween and being selectively detachable thereto. A U-shaped boom extends over the left and right leg members when used as a roll bar. The boom, at one end, is pivotally connected to a pivot member about a horizontal axis of rotation and the pivot member is pivotally connected to one of the leg members and is pivotable about a vertical axis of rotation. A hydraulic jack selectively lifts and lowers the boom when used as a crane. Covers are provided on the boom left and right legs and hide from plain view working components including the hydraulic jack.

Abstract: A boom and mast apparatus includes a transverse support member which has a proximal portion and a distal portion. A longitudinal mast assembly is connected to the distal portion of the transverse support member. The longitudinal mast assembly includes a support-member-connected end and a boom-member-connected end. The longitudinal mast assembly also includes a lower segment connected to the transverse support member, an upper segment, and a connector assembly for selectively connecting the upper segment to the lower segment. A first bearing ring is connected transversely to a topmost portion of the lower segment. A second bearing ring is connected transversely to a bottommost portion of the upper segment. The second bearing ring is placed in registration with the first bearing ring when the boom and mast apparatus is assembled. A boom member is connected to the boom-member-connected end of the longitudinal mast assembly. A winch assembly is connected to the upper segment of the longitudinal mast assembly.

Abstract: A boom hoist is disclosed having top and bottom mast sections joined together midway of an upstanding mast at a swivel joint defined by mating flange faces where the top mast section rotates about a central core extending into each mast section. A boom arm is pivotally carried by the top mast section and a universal attachment base is carried by the bottom mast section having a tongue connection for connecting the hoist to a plurality of associated structures for hoist operation. Advantageously, a side mount assembly for mounting the hoist near a side of a vehicle, a three-point hitch mount assembly for mounting the hoist to a farm tractor, a fork lift mount assembly, a floor mount assembly, and a roller frame mount assembly are provided for the hoist.