Abstract: In a scaffolding at least one tower anchor to secure the tower to a wall, a sleeve surrounding the tower and guided for up and down movement along the same, a support frame releasably secured to the sleeve in vertical position and normal to the wall, a shiftable frame moveably supported by and parallel to the support frame, replace ("the wall supported by the sleeve not ",) by and releasably secured to the shiftable frame at one end a work platform parallel to for horizontal shifting movement transversely of the tower towards and away from the wall and an actuator carried by the support frame and acting on the work platform through the intermediary of the shiftable frame to effect said shifting movement.

Abstract: A personnel lift (20) having adjustable side-to-side shim assemblies (38a-d) used in conjunction with a series of slide blocks (39, 40) in the mast of the personnel lift. The mast of the personnel lift includes a number of nested columns (24a-e) that extend to lift a person and an aerial work platform (22) to a desired height. The shim assemblies (38a-d) and slide blocks (39, 40) are used to maintain the nested columns (24a-e) in proper alignment, and the shim assemblies (38a-d) are adjustable to account for wear. The adjustable features of the shim assemblies (38a-d) are accessible when the columns are fully assembled, which allows the shim assemblies (38a-d) to be adjusted without requiring that the mast be disassembled.

Abstract: A scaffolding mast with at least two profile bars (1, 2, 3) which are attached to the edges of a triangle or square forming the cross section of the scaffolding mast. Two of the profiles (1, 2, 3) are connected to one or two of three connecting plates (10, 17, 18) forming the side of the triangle or square. Two grooves (4-9) are provided on the inner area of each of the profile bars (1, 2, 3) in which 90.degree. offset edges (13, 14) of the connecting plate (10, 17, 18) are inserted and fastened at the place of insertion (FIG. 1).

Abstract: A scissors-type work platform lift machine includes a chassis, a work platform, a scissors lift mechanism, and a telescopable electro-mechanical actuation arrangement. The work platform is disposed above the chassis. The scissors lift mechanism has a plurality of portions pivotally movable relative to one another, an upper end portion pivotally mounting the work platform above the chassis, and a lower end portion pivotally mounted on the chassis. The pivotally movable portions are movable vertically between retracted and expanded conditions so as to move the work platform between lowered and raised positions relative to the chassis. The actuation arrangement extends and is mounted to selected upper and lower ones of the pivotally movable portions of the lift mechanism and is adapted to operate the lift mechanism between the retracted and expanded conditions.

Abstract: A collapsible hunting stand for supporting a user above a ground surface. The collapsible hunting stand includes a top plate with upper ends of a plurality poles pivotally coupled thereto. A platform is positioned between the poles beneath the top plate. A pulley system connecting the platform to the top plate to permit raising and lowering of the platform.

Abstract: A lift apparatus includes a superstructure frame support, a riser, and an articulated parallelogram boom assembly operatively connected between the superstructure frame support and the riser. The articulated parallelogram boom assembly includes a floating frame, a lower parallelogram boom assembly operationally connected between the superstructure frame support and the floating frame, an upper parallelogram boom assembly operationally connected between the floating frame and the riser, and a lift mechanism for raising and lowering the articulated parallelogram boom assembly. The lower parallelogram boom assembly, the upper parallelogram boom assembly, and the lift mechanism are formed such that the maximum extension height of the articulated parallelogram boom assembly is increased without an increase in the height of the articulated parallelogram boom assembly when lowered.

Abstract: A lifting scalfold assembly with several scaffolding poles which stand on a base and which are extendable in length and, between which mobile platforms are situated such that they can be adjusted in height, whereby the scaffolding poles are attached to a building by means of holding supports each scaffolding pole includes at least a girder section housing which at least a gear rack on an inside and a gear rack on an outside thereof. On the mobile platforms cogwheels and drives for the cogwheels running on the outer gear racks are provided. A sliding module or carriage includes cogwheels and drives for the cogwheels running on the inner gear connected to the girder section. Conduction rails are included on the scaffolding pole, and current collectors are positioned on the connectable mobile platforms and the sliding modules.

Abstract: A guide roller supporting apparatus for an elevator car includes a guide roller supporting apparatus comprising guide rollers making contact with surfaces of a guide rail, respectively, each guide roller being rotatably mounted on an upper end of a carrying member, a lower end of the carrying member being pivotably mounted on a frame secured to a top or a bottom plate of an elevator car; a spring mechanism resiliently urging the guide roller against the corresponding surfaces of the guide rail to absorb a lateral force of an impact transferred through the guide roller; and a support secured to the frame and having a spring seat, whereby the vertical force supports the carrying member, an external impact through the guide rollers is divided into vertical and lateral forces, and the lateral force is absorbed to decrease a shaking of the elevator car.

Abstract: A scaffold having a platform, support legs, support beams supporting the platform, side rails connecting the legs, guard rails, and spring-biased slidable pins securing the support legs to the support beams. Each slidable pin is at an acute angle to the plane of the support platform and axis of its associated support leg and support beam (preferably at 56. degrees to the axis of the associated support leg). This acute-angle pin structure renders that scaffold more rigid and secure while preserving the ability to easily assemble, adjust, and dis-assemble the scaffold. The platform also includes spacers inserted between the platform and support legs to force the legs away from the platform, eliminate play in the structure, and make the scaffold more rigid and secure.

Abstract: In accordance with one embodiment of the present invention, the mobile lift system includes a 3 ft..times.3 ft. rack and pinion platform lift providing a cage able to lift at least one man and gear up a pole of a billboard sign or any advertising sign and to detach the platform from the rack so access can be achieved at many different pole/rack sites with a single platform lift. The mobile hoist or lift is practical because it eliminates ladders from tall poles and provides safer route access. This will save time for the worker because his harness has been eliminated and the hardship of climbing the ladders has also been eliminated. Another point of interest will be the saved money and reduced liability because the ladders have been removed so that unauthorized individuals cannot climb up the poles. Mobilizing the lift saves money in material cost and maintenance because there may be one platform for 150 racks (poles) or more.

Abstract: Rescue apparatus including a track mounted vertically on an outside surface of a building, a pulley mounted on the building above the track, a non-rescue-grade guide cable arranged for moving along the track, an upper end of the guide cable engaging the pulley, and release apparatus for arresting downward movement of the upper end of the guide cable and for selectively releasing the upper end of the guide cable so as to permit downward movement of the upper end of the guide cable.

Abstract: Novel motorized scaffold hoisting units are provided that are intended to be used in pairs with two jack poles. Each unit comprises a carriage that is adapted to be slidably disposed on a jack pole and has guide means that restrain the carriage from moving laterally while allowing it to be raised or lowered along the length of the pole. Each unit also comprises a hoist or winch that is mounted on a platform carried by the carriage and comprises a cable-carrying drum and a power transmission for rotating the drum in response to rotative power supplied by an auxiliary electrically powered driver. The outer end of the cable carried by the drum is adapted to be releasably attached to the upper end of a jack pole on which the unit is mounted. Each carriage also carries at least two fail-safe brake means for releasably gripping the pole on which the carriage is mounted, and means in the form of a laterally-projecting arm for supporting a scaffold, e.g., a wooden or aluminum plank.

Abstract: An improved hydraulic drive mechanism for a vertical conveyor. The conveyor comprises a pair of upright supports or columns and a carriage to support a load or cargo is guided for vertical movement on the columns. The drive mechanism includes a pair of first hydraulic cylinder units and a pair of second hydraulic cylinder units that preferably have twice the length of the first cylinder units. The first or shorter cylinder units are connected between a movable cross beam and the carriage, while the second cylinder units are connected between the movable beam and the upper end of the frame. At a lower level both the first and second cylinder units are in an extended condition, while at an upper level both cylinder units are retracted.

Abstract: A mechanism for preventing tipping of a lifting device having a main frame supported by a plurality of ground engaging support elements and a lifting element raisable and lowerable with respect to the main frame, the mechanism comprising a subframe mounted on the main frame and extending thereunder and intermediately disposed between all of the support members, and a parallel linkage mechanism for raising and lowering the subframe with respect to the ground in response to the lowering and raising of the lifting element respectively.

Abstract: A method and apparatus for applying ceiling panels to a light tunnel is provided. The applicator hereof includes a gantry, a frame, and a shifter for vertically shifting said frame relative to said gantry. The frame is presents a pair of generally arcuate spaced-apart rails each having a pair of terminal feet, with a bridge interconnecting the feet. The gantry includes a plurality of towers each having a pair of upright tower legs. The tower legs are attached to a base and preferably further supported by braces to maintain an upright configuration. A shifter is provided to operatively interconnect the gantry and the frame for raising the latter and the panel placed thereon into juxtaposition with a framework of the light tunnel. In accordance with the method, the applicator is placed within the framework of the light tunnel, a panel is placed on the platform, and the platform is shifted to place the panel in position for attachment to the framework.

Abstract: A personnel lift (20) having adjustable side-to-side shim assemblies (38a-d) used in conjunction with a series of slide blocks (39, 40) in the mast of the personnel lift. The mast of the personnel lift includes a number of nested columns (24a-e) that extend to lift a person and an aerial work platform (22) to a desired height. The shim assemblies (38a-d) and slide blocks (39, 40) are used to maintain the nested columns (24a-e) in proper alignment, and the shim assemblies (38a-d) are adjustable to account for wear. The adjustable features of the shim assemblies (38a-d) are accessible when the columns are fully assembled, which allows the shim assemblies (38a-d) to be adjusted without requiring that the mast be disassembled.

Abstract: The self-contained device for cleaning and coating hold surfaces in a bulk carrier includes four major components, namely a horizontally mobile vertical tower (e.g., with walking beams for permitting the device to move into the four corners of the hold into which it has been lowered), a vertical trolley for permitting the workers to reach with their equipment all elevations within the hold, a horizontal trolley for permitting the workers to achieve optimum proximity to a wall surface, and cleaning and coating support equipment and systems.

Abstract: The invention consists of an active scaffolding system adapted to hold a payload, said active scaffolding system comprising: (a) a plurality of adjustable links and rigid links connected by joints; (b) a plurality of actuator devices associated with the adjustable links so as to change to length of the adjustable links; (c) a microprocessor to determine how the lengths of each of the adjustable links throughout a number of time steps; the microprocessor being provided with computer program instructions to resolve the Cartesian end point translational and rotational motions; and (d) the adjustable links, rigid links, and actuator devices forming an active scaffolding adapted to move a payload around environmental obstacles while supporting said payload against the force of gravity.

Abstract: A compact, lightweight, power lifting unit assists the operator of a mobile patient transporter in raising or lowering the patient bed to the desired height required in transporting or transferring a patient. The power lifting unit may also be used to "collapse" the transporter. The power lifting unit uses a ball screw and ball nut to convert the rotary motion of an electric motor to the linear motion necessary to drive a tension arm and raise or lower the transporter. The power lifting unit is adaptable and may be installed on virtually any existing transporter.

Abstract: A platform which is raised and lowered evenly in a vertical direction only by a pair of piston activated four-bar linkages which are linked together through an endless cable or belt which will not allow one four-bar linkage to act independently of the other.

Abstract: A push up expansion floor for providing a work floor is adjustable and mounted on vertical square shafts. The floor can move up and down on the shafts, can be locked in place on the shafts, and has adjustable extension members for increasing floor area above vertical shafts. The floor is moved up and down on the vertical shafts by means of a wire rope and is locked in place by means of bolts. Rising above the moving work floor is an expansion floor. The expansion floor raises up on the vertical shaft 17 while the moving work floor rolls on rollers at the bottom of separate floor supports.

Abstract: A compact, lightweight, power lifting unit assists the operator of a mobile patient transporter in raising or lowering the patient bed to the desired height required in transporting or transferring a patient. The power lifting unit may also be used to "collapse" the transporter to its lowest height. The power lifting unit uses a ball screw and ball nut to convert the rotary motion of an electric motor to the linear motion necessary to drive a tension arm and raise or lower the transporter. The power lifting unit is adaptable and may be installed on virtually any existing "X" frame transporter. Electronic controls allow a single operator to raise or lower the patient bed or allow the patient bed to coast gently to a rest position.

Abstract: A powered lift platform apparatus is disclosed having a fixed support structure and two independently operable platforms which move in both the vertical and horizontal direction, for use with transport containers, such as trailers, shipping containers or rail cars. Each platform comprises an extended work surface or walkway and two moveable end platforms which extend perpendicularly to the extended work surface. Each platform may be independently raised and lowered, and each may be moved laterally toward the opposite platform. The distance between the two platforms and the length of the end platforms, coupled with the range of lateral movement of each platform, are such that the free ends of opposing end platforms can be juxtapositioned to create a rectangular pathway for workers to completely circle the transport container.

Abstract: The scaffolding comprises a post having a plurality of vertically aligned and equally spaced studs protruding on one of its surfaces. A frame supporting a work platform can move along the post, a sleeve being attached to the frame for guiding it along the post. The sleeve, the frame and the work platform partially surround the post. A lifting apparatus, installed on the sleeve, comprises a rotatable endless screw which is parallel to the post and which has a peripheral and helical flange which bears on the studs. An engine, an electric power drill or a manual handle will rotate the endless screw via one or two speed reducers. The rotation movement of the endless screw will result in the axial displacement thereof along the post, carrying the frame and work platform along with it. Another embodiment of the invention comprises a work platform which is supported at both of its ends by a lifting apparatus movable along a post.

Abstract: A lifting platform for motor vehicles has at least one scissor-type framework with at least two lower scissor levers that cross each other and two upper scissor levers that cross each other. Either the upper or lower of two pivotably connected scissor levers is configured with a slot shape of a type which opens toward the other scissor lever, and this other scissor lever sinks at least most of the way into this slot when the platform lift is in its lowered position. Instead of a U-shaped slot configuration, the upper or lower of two pivotably connected scissor levers may have an L-shaped profile opening toward the other scissor lever and permitting it to sink into the crook of the L.

Abstract: A self-climbing device, in particular for a climbing scaffolding, with at least one linear drive which produces a relative motion between at least one moving console and at least one mounting rail running in the displacement direction, in particular when the linear drive alternately displaces a scaffolding section and, following attachment of same to the wall and loosening of the attachment of the mounting rail, the mounting rail by a working section, is characterized in that the connection between the linear drive (13) and the mounting rail (6) is established by climbing heads (14, 15) arranged at separations from each other which exhibit at least one pivotable locking member (24) functioning in the manner of a detent pawl and locking cams (29) are provided for on the mounting rail (6) along the path of the locking member (24) during relative motion between the mounting rail and the climbing head which cooperate with same and the locking member (24) is lifted over the locking cams (29) by relative motion in

Abstract: An bi-directional, adjustable elevating and support mechanism to assist in the removal, installation and repair of rack-mounted items such as electronic telecommunications modules by supporting and aligning such modules during the removal, installation and repair of such modules from support racks.

Abstract: A scaffolding floor is provided on the upper ends of four expandable and contractible struts. A support frame protrudes downward from the scaffolding floor. An end of a line is connected to the lower end of the support frame and the other end of the line is connected to the fixed part of a hydraulic jack which is provided in the lower part of the struts, so that the scaffolding floor can be elevated or lowered through the line in accordance with the raising or lowering of the hydraulic jack.

Abstract: A modular scaffolding assembly in which the platform may move up or down in a continuous motion. A platform carriage is engaged with a tower by spring loaded friction blocks and climbs or descends the tower along a pair of stepped racks. Platform modules may be removably connected to the platform carriage.

Abstract: A platform is equipped with a chair, which chair is displaceable along a mast, and to which chair platform components can be affixed, whereby, force indication means are incorporated between the chair and the platform components so that an indication can be provided concerning the differences in the mechanical loading of the platform components located at opposite sides of the chair.A simple embodiment arises through the application of a beam which is freely-spanned with respect to the chair and which is connected in a hinged manner with the platform components, within which beam force indication means are incorporated.

Abstract: A scaffolding system which is attached to a prime mover such as a front end loader or forklift and has "Wings" or platforms extending outward from a "Center Frame" or platform and rotating in relation to it. The surface of the "Wings" upon which workmen stand is made up of individual steps. The tread of each step remains in a horizontal position during "Wing" rotation by using the principle of parallel arms. The "Center Frame" or platform can rotate in relation to a "Base Frame" to level the working surface despite the prime mover sitting on a sloping surface. All working surfaces are equipped with necessary guard rails. Hydraulic controls and emergency shut down switches are located for safe operation by all workmen.

Abstract: A stepladder for positioning equipment and material. The stepladder includes a head step assembly with one or two openings, and a lifting mechanism mounted to the head step assembly. The lifting mechanism removably receives a shaft at one end and the other end passing through one of the openings and removably receiving the equipment and/or material load. The stepladder is mounted over a wheeled platform. The shaft may include a tubular extension and a spring member for dividing the load weight between the stepladder and the shaft, when the latter is in contact with the supporting hole through the pulley housing that removably holds it. An additional shaft can be removably mounted to one of the openings to provide further stability to the structure.

Abstract: A lift apparatus includes a lift device and a hitch and mounting assembly for connection to the three point hitch of a conventional tractor. The lift device includes a lower boom and an upper boom pivotally connected together and connected to an occupant bucket. The boom arm is connected to a turntable mounted on a base. The base is secured to and support on a support frame of the hitch and mounting assembly. A vertically disposed hitch frame is rigidly secured to the support frame and is provided with hitch members for connection to the three point hitch of a conventional tractor.

Abstract: A mechanical device that supports a variable height tray (20) which is removable or may be swiveled out of the way for storage. It is connected to the cross bar support (24) by it's tray arms (42) at the tray pivots (40) which protrude as studs from the cross bar support (24). The cross bar support (24) is attached to steel threaded shafts (26) with shaft nuts (22). The shafts (26) are inserted into the retraction tubes (38) that provide support. Engagement windows (30) allow the spring loaded clamps (32) to engage against the threaded edges of the shafts (26) thus allowing them to lock into place at the desired height. The spring loaded clamps (32) are attached to the retraction tubes (38) with pipe clamps (34) and their leverage ends are tied together in tandem fashion with a release bar (36) that permits simultaneous operation. The entire mechanism is mounted to a step ladder with screws and standard electro mechanical tubing clamps.

Abstract: A circular robotic device has retractable extendible surface engaging drives controlled by linear actuators. A pressure transducer indicates the pressure exerted by one such drive on the surface if the pressure is to high the drives are retracted, if the pressure is too low the drives are extended. A more sophisticated version controls the pressure exerted by each drive independently. In a pole centering version this providing a tight clamp allows the device to climb and descend the typically tapered poles. The device can prime and paint poles to predetermined thickness, as well as sandblast the poles. In a pipe cleaning version the drive engage the internal surface of a pipe. The pipe cleaning version carries pipe cleaning and/or X-ray equipment. A microprocessor monitors the device and provides status information to a remote control unit.

Abstract: A mobile work and servicing platform trailer is disclosed. The platform trailer can include a roof section that is formed from a metal grate with openings therethrough. A first level of storage hoppers located beneath the roof section catch debris passing through the grates. Screw-augers located beneath the first level of storage hoppers can pass debris passing through spigots on the undersurface of these augers to troughs with screw-auger inside the troughs. Rotation of the screw auger causes the debris to move to other spigots which pass the debris to a second level of storage hoppers. The roof is vertically raisable from an initial low position to various heights. Winged side panels on the platform trailer rotate along hinges on opposite sides of the roof section. The outer edges of side-panels are raisable to the same height as the outer edges of the roof section and up to approximately thirty to forty degrees angled above the roof section.

Abstract: A mobile lifter including a cylindrical casing supported on a stand, a plurality of inner tubes that slide one inside another and received in the cylindrical casing, a set of pulleys respectively mounted on the inner tubes at different elevations, a winch wound round with a cable, the cable having one end fixed to and wound round the winch and an opposite end inserted in pulleys and then fixed to the bottom end of said fourth inner tube, and a driving mechanism mounted on the cylindrical casing on the outside and controlled to turn the winch, causing it to take up or let off the cable so as to lift or lower the mobile lifter.

Abstract: A mobile self-propelled aircraft loading bridge adaptor for bridging between small aircraft and the conventional bridge entry ways provided at airports for use with standard size jets and similar aircraft. In one embodiment, the bridge is supported by spaced apart adjustable lifts that provide independent elevation and lowering of portions connected to the lifts. In another embodiment, a pivot is positioned at a predetermined location near one end of the bridge, and it is operative in combination with a hydraulic lift located near the other end of the bridge to provide desired adjustment. In still another embodiment, the bridge is deployed between a small aircraft and a bus.

Abstract: A lightweight, compact power lifting unit has one or more tension arms for applying the force required to adjust the height of a "gurney" or mobile patient transporter. In one embodiment, a ball screw and nut are used to drive the tension arms, reducing both the weight and the power requirements of the power lifting unit. The power lifting unit is adaptable to being installed on existing transporters.

Abstract: A work platform assembly and trailer system for transporting and vertically positioning the work platform assembly adjacent bridge deck surfaces to be treated. The trailer includes front and rear lifting assemblies for supporting, and being removably attached to, an end of the work platform assembly. The lifting assemblies include vertically oriented lifting cylinders for vertically positioning the work platform assembly immediately adjacent the bridge deck surfaces to be treated. The trailer includes wheels and a hitch to facilitate the transport of the work platform assembly to the site of the bridge deck. The work platform assembly is modular in construction so as to be configurable according to the configuration and size, particularly width, requirements of each bridge and to metal surfaces thereof which are to be reconditioned by abrasive stripping and recoating.

Abstract: A portable hydraulic lift step stool for raising handicapped patients to an elevated location comprising of a lower base positionable upon a floor, the lower base having parallel corner walls extending upwardly therefrom. An upper base having a planar surface, the upper surface of which is adapted to support a patient to be lifted and transported, the lower surface of which faces the lower base, the upper base having front and rear edges with a downwardly extending plate adapted to be positioned between the upwardly extending corner walls of the lower base. And a hydraulic jack having an upper end secured to the lower surface of the upper base and having a lower end secured to the upper surface of the lower base, the hydraulic jack including a handle extending outwardly from the upper base and lower base in a space between the corner walls of the lower base, the handle adapted to be pumped to raise and lower the hydraulic jack, the jack also having a switch for reversing the direction of movement of the jack.

Abstract: A lifting apparatus capable of lifting operators or materials upward and capable of lifting a platform on which heavy materials are placed to an elevated spot. The lifting apparatus comprises a pair of middle booms which are rotatably coupled to each other at the center thereof in an X-shape, a lower boom which is extended from or contracted in the middle boom and is connected to a chassis, an upper boom which is extended from and contracted in the middle boom and is connected to the platform, and an operating mechanism which is disposed between the chassis and the middle booms and is movable from a folded position into a vertically straight position for lifting the middle booms.

Abstract: The present invention provides a frame constructing method for constructing frames for reducing the cost for assembling frames, for making it possible to execute the construction works under any weather conditions, further for shortening the term of works, and for enabling to improve safety in the executions, to automate the executions and to save labor.

Abstract: In a dock for carrying out work on an aircraft (18), support slides (34) which are carried by support frameworks (20-24, 28) are provided and are adjustable in a horizontal and a vertical direction. The support slides (34) each have guide rails (36, 38), running in which is a bottom section (40) to which a work platform (30) is fastened via two scissor-type linkages. The support slides (34) may be moved into an aligned position so that a work platform support section (40) is movable from one support slide to the other.

Abstract: A climbing vehicle comprising a rigid frame which is provided with a loading platform and is carried by a pair of drive wheels which, in working position, rest against the pole-like element to be climbed. The frame supports a motor element actuating the drive wheels. A pair of arms is articulated at the front of the frame and supports a pair of counteracting wheels which are freely rotatable about a horizontal axis, whereat the counteracting wheels are arranged to be clamped, during work, against the pole-like element to be climbed, in a position opposite to the drive wheels.

Abstract: In a screw lift the lift cage is carried by a drive nut rotatably provided on an essentially upright screw, the lift cage carrying a bearing means and a drive means for the nut. The screw is supported by several supporting braces attached thereto along the length thereof. The nut has the shape of a spiral having turns, the pitch and axial thickness of which are adapted to the distance between the braces and the dimensions of these in the length direction of the screw so as to enable the nut to pass freely past the braces by passing between the turns of the nut during the passage.

Abstract: An improved scaffold of the lift type having a base and a working platform on top of the base. Vertical support posts are provided at the corners of the base passing through guide means at the corners of the platform. Cooperating drive means on the platform and posts are used to raise or lower the platform on the posts relative to the base. A motor on the platform selectively operates the drive means.

Abstract: Disclosed is an apparatus having a work platform comprised of an expandingly extendable basket mounted on an underframe. The basket has a relatively mobile portion that translates out from the underframe and out from a relatively stationary portion of the basket fix to underframe. Mounted to the underframe are rollers engaging beams supporting the relatively mobile portion of the basket, the beams translating on the rollers when the basket expands. The basket is raised and lowered on pivot arms which are connected between the underframe and a base of the apparatus. The position and movement of the arms are controlled by a screw jack fixed to the work platform. An adjustable position stairway is connected between a second, fixed work platform and the first, expandable work platform.

Abstract: A stable lift apparatus for a pickup truck includes a base which is supported on the sidewalls of the cargo compartment. Each of a pair of scissor assemblies has two lifting arms having the front ends pivotably attached to one of the base and a raisable platform. A pair of hydraulic cylinders moves a central pivot shaft upward to raise the platform. A portable stabilizer has a ground engaging foot adjustable in distance from the stabilizer's pivotable attachment to the lift apparatus or pickup truck. Prior to setting the stabilizer, its length is greater than the distance to the ground. Movement of the truck a short distance sets the stabilizer in a stabilizing mode.

Abstract: A vertical conveyor for lifting materials between different vertical levels. The conveyor comprises a pair of spaced upright supports or beams and a carriage to support a load or cargo is guided for vertical movement on the beams. A hydraulic cylinder unit is associated with each beam and the ram or piston rod of each cylinder unit carries a first sheave, while a second sheave is located at the upper end of each beam. A link chain formed of a plurality of interconnected loops is trained over each first and second sheave, and one end of each chain is dead-ended on the respective beam, while the opposite end of the chain is connected to the carriage. Retraction of the piston rod will move the carriage upwardly to a second vertical level. The axes of the first sheaves are located at 90.degree. with respect to the axes of the second sheaves, so that the cylinder can be mounted tight against the beams to minimize the bending moment.