Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
  • B66F11/00—Lifting devices specially adapted for particular uses not otherwise provided for
  • B66F11/04—Lifting devices specially adapted for particular uses not otherwise provided for for movable platforms or cabins, e.g. on vehicles, permitting workmen to place themselves in any desired position for carrying out required operations
  • B66F11/044—Working platforms suspended from booms
  • B66F11/046—Working platforms suspended from booms of the telescoping type
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/18—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes
  • B66C23/36—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes mounted on road or rail vehicles; Manually-movable jib-cranes for use in workshops; Floating cranes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/18—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes
  • B66C23/36—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes mounted on road or rail vehicles; Manually-movable jib-cranes for use in workshops; Floating cranes
  • B66C23/42—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes mounted on road or rail vehicles; Manually-movable jib-cranes for use in workshops; Floating cranes with jibs of adjustable configuration, e.g. foldable
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66F—HOISTING, LIFTING, HAULING OR PUSHING, NOT OTHERWISE PROVIDED FOR, e.g. DEVICES WHICH APPLY A LIFTING OR PUSHING FORCE DIRECTLY TO THE SURFACE OF A LOAD
  • B66F17/00—Safety devices, e.g. for limiting or indicating lifting force
  • B66F17/006—Safety devices, e.g. for limiting or indicating lifting force for working platforms
• • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
  • F15—FLUID-PRESSURE ACTUATORS; HYDRAULICS OR PNEUMATICS IN GENERAL
  • F15B—SYSTEMS ACTING BY MEANS OF FLUIDS IN GENERAL; FLUID-PRESSURE ACTUATORS, e.g. SERVOMOTORS; DETAILS OF FLUID-PRESSURE SYSTEMS, NOT OTHERWISE PROVIDED FOR
  • F15B15/00—Fluid-actuated devices for displacing a member from one position to another; Gearing associated therewith
  • F15B15/20—Other details, e.g. assembly with regulating devices
  • F15B15/26—Locking mechanisms
  • F15B15/261—Locking mechanisms using positive interengagement, e.g. balls and grooves, for locking in the end positions

Definitions

• the invention relates to a method for locking a boom into a desired operating position.
• a lift cylinder used for raising the boom is locked mechanically to prevent the cylinder from retracting.
• At least one of the boom lift cylinders is provided with a locking device to perform the locking.
• the invention further relates to a personnel hoist and a boom lift cylinder.
• the field of the invention is described in greater detail in the preambles of the independent claims of the application.
• a personnel hoist is used e.g. in fire fighting and rescue operations as well as in building construction works and different maintenance duties.
• a personnel hoist comprises a boom that is raised from a transport position to a vertical position by one or more lift cylinders. If the boom is long, also a lift cylinder with relatively long dimensions is to be provided. In that case a hydraulic lift cylinder also has fluid spaces of a large volume. Although the compressibility of fluid is small, a long lift cylinder has flexibility due to its large fluid volumes. It is also to be noted that since the lift cylinder is at the bottom end of a long boom, even minor flexibility in the lift cylinder causes large movements at the top of the long boom. Such flexibility impairs significantly the positioning of the boom.
• a locking device fastened to the cylinder body of the lift cylinder has been designed to mechanically lock the piston rod.
• a prior art locking device wedges the piston rod to lock it immovable.
• a disadvantage of this solution is that the wedge members are pressed at an extremely great force against the piston rod, which may damage the rod surface and thus cause leakage in the lift cylinder.
• An object of the invention is to provide a novel and improved method for locking the operating position of a boom, a personnel hoist, and, further, a novel and improved lift cylinder.
• the method of the invention is characterized by providing a first locking member and a second locking member with a matching, rotational- ly non-symmetric shape in the longitudinal direction of the lift cylinder; and selecting the operation of the locking device between a released position and a locking position by changing the respective positions of the locking members about the longitudinal axis of the lift cylinder, the rotationally non-symmetric shapes of the locking members thus occupying a matching or a non-matching position, respectively.
• the personnel hoist of the invention is characterized in that the first locking member comprises a tubular part and an end piece arranged around the lift cylinder; that the end piece comprises a locking aperture having a rotationally non-symmetric shape; that the second locking member is fastened to the outermost end portion of the cylinder body and the shape of the outer surface of the second locking member substantially corresponds to the shape of the locking aperture, whereby the second locking member and the locking aperture match in the direction of the longitudinal axis of the lift cylinder; and that the locking device comprises at least one turning device allowing the first locking member to be rotated about its longitudinal axis so that in the released position the locking aperture is placeable to match the second locking member and, on the other hand, in the locking position the locking aperture is placeable to a non-matching position in relation to the second locking member.
• the lift cylinder of the invention is characterized in that the first locking member and the second locking member comprise matching rotationally non-symmetric shapes in the longitudinal direction of the lift cylinder; and that the locking device comprises at least one turning device allowing the relative position of the locking members to be rotated in relation to the longitudinal axis of the lift cylinder so that in the released position the rotationally non- symmetric shapes of the locking members are placeable to match each other and, on the other hand, in the locking position they are placeable to non- matching positions.
• At least one of the boom lift cylinders comprises a locking device provided with at least one first locking member and at least one second locking member which are independent of the basic structure of the lift cylinder.
• the first locking member is an elongated piece arranged to move with the piston rod and in relation to the cylinder body and to a second locking member fastened thereto.
• the locking device further comprises means for coupling the first and the second locking member to be immovable in relation to each other in the longitudinal direction at least in the return direction of the lift cylinder. In the released position of the locking device the lift cylinder may be freely extended and retracted.
• the basic idea of the locking is that when seen in the longitudinal direction of the lift cylinder, the locking members are provided with rotationally non-symmetric yet matching shapes or shaped surfaces and therefore rotating the locking members in relation to one another allows a locking position and a released position to be selected.
• the locking reflects the rotating positions and compatibility of the locking members in relation to each other in the longitudinal direction of the lift cylinder.
• An advantage of this is that locking forces caused by the operation of the locking device act on the locking members, which are independent of the basic structure of the lift cylinder and therefore locking does not damage the lift cylinder in any way.
• the locking causes no forces that could damage the piston rod and its sealing surfaces.
• the locking device is strong and both its structure and operation are simple.
• the first locking member and the second locking member are locked in a shape-locked manner in relation to each other in at least one pre-determined locking position.
• the shape-locking is firm and allows the boom to be locked to a pre-determined position with precision.
• the shape-locking may have a simple structure.
• the first locking member is a tubular piece, and the second locking piece is arranged to act on the tubular first locking member.
• the tubular first locking member is arranged to surround the piston rod of the lift cylinder, thus protecting the piston rod against damages.
• the tubular locking member may have an outer surface which is impermeable and has no openings and therefore it is capable of protecting the piston rod also against impurities.
• the first locking member is a tubular piece with a rectangular, preferably square, cross-section. This embodiment facilitates the manufacturing of the locking device.
• the first locking member is a tubular piece with an impermeable outer casing.
• the top end of the tubular locking member is sealed with sealing members. This prevents impurities, dust and water, such as fire fighting water, from entering the locking device from above.
• the bottom end may be sealed, the locking device being thus protected also against impurities entering from below.
• the bottom end may be open, whereby an aired structure is provided and no humidity due to condensation, for example, forms inside.
• the first locking member serves as a security lock and protection for the piston rod of the lift cylinder.
• the first locking member is arranged to support the structure of the lift cylinder, which is a feature that may be taken into account in the design of the structural parts of the lift cylinder.
• the tubular first locking member is arranged around the lift cylinder and moved together with the piston rod in relation to the cylinder body.
• the second locking member is immovably arranged on the outermost end portion of the cylinder body.
• the first locking member and the second locking member have matching, rotationally non- symmetric shapes when seen in the longitudinal direction of the lift cylinder.
• the tubular first locking member may be rotated about its longitudinal axis with respect to the second locking member to select a released position or a locking position.
• both cylinders being provided with a tubular first locking member with one common rotating device provided between them.
• the turning device allows the first locking members of the adjacent lift cylinders to be rotated to select the released position and the locking position of the lift cylinders.
• the locking device only locks the return movement of the lift cylinder.
• the locking device locks the lift cylinder in both directions, i.e. in the return direction and the impact direction.
• one or more detection members are provided in association with the locking device to allow the locking state and the released position of the locking device to be detected.
• the personnel hoist has a control unit that may comprise a control strategy to prevent a normal use of the boom until the locking position is detected. This embodiment improves safety. When in operation, the boom is always secured by a mechanical locking device as a precaution against hose breaks and other damages.
• Figure 1 is a schematic view of a personnel hoist with its boom raised up to the operating position and its telescoping boom portions extended;
• Figure 2 is a schematic view of a personnel hoist with its boom in transport position supported by a chassis
• Figure 3 is a schematic view of a boom of the invention in the transport position
• Figure 4 is a schematic view of the boom of Figure 3 raised up in its operating position
• Figure 5 is a schematic view of a detail of a locking device in its locking position and its released position
• Figure 6 is a schematic view, seen from the longitudinal direction of the hoist cylinder, of the released position and the locking position of the locking device in the arrangement of Figure 4.
• FIG. 1 shows a personnel hoist 1 comprising a chassis 2 provided with a boom 3.
• the chassis 2 may be a movable chassis, such as a vehicle or a trailer.
• the chassis 2 may be provided with a pivoting frame 4 to which the bottom end of the boom 3 is attached by a first joint 5.
• the top end of the boom 3 may be provided with a man cage 6 accommodating one or more persons to be lifted.
• the man cage 6 may also is provided with tools, such as equipment needed for spraying fire extinction medium.
• the boom 3 may comprise only one boom section or two or more articulated boom sections.
• the boom 3 in Figure 1 comprises a first boom section 3a and a second boom section 3b, with a second joint 7 between them.
• the bottom part of the first boom section 3a is fastened to the pivoting frame 4 by a first joint 5 to allow it to be raised and lowered in relation to the joint 5.
• the second boom section 3b may be raised and lowered in relation to a second joint 7.
• reference numeral 3b' designates the second boom section raised in the top position.
• the length of the first boom section 3a and the second boom section 3b may be changed telescopically, which allows the boom 3 to be retracted for transport position B shown in Figure 2 and extended into a desired length in operating situation A.
• the personnel hoist can have a very long reach. As numbers of high-rise buildings increase, personnel hoists used in rescue operations in particular must allow ever greater heights to be reached. The reach may be as much as 100 meters.
• Figure 2 shows the boom 3 of the personnel hoist driven to the transport position on the chassis 2.
• Figures 1 and 2 further show a lift cylinder 8 with its bottom end fastened to the pivoting frame 4 and its top end to a fastening lug 9, or the like, located at a distance from the bottom end of the first boom section 3a.
• the lift cylinder 8 may be a hydraulic cylinder. Only one lift cylinder 8 may be sufficient to raise the boom 3 from a transport position B to an operating position A, although typically two, three or even more lift cylinders are used.
• the lift cylinder 8 has a long stroke to allow the first boom section 3a to be raised to an almost vertical operating position A.
• the lift cylinder 8 is dimensioned to enable it to move the long boom 3 in a controlled manner to raise and lower it.
• Figure 3 only shows the first boom section 3a, which is in a substantially horizontal transport position B.
• the lift cylinders 8, two for example are driven in their most retracted position where the piston rod is almost entirely inside the cylinder body.
• the outermost end of at least one lift cylinder 8 has fastened thereto a first locking member 10 that may be an elongated tubular piece capable of moving with the piston rod and sliding on the cylinder body.
• the tubular first locking member 10 may cover the lift cylinder 8 substantially entirely.
• the pivoting frame 4 may be pivoted in the direction of arrow C about a vertical joint, and the lift cylinder 8 may be extended and retracted in linear direction D to raise and lower the boom portion 3a in direction G in relation to the joint 5.
• the boom section 3a has been raised to the operating position A, where it points directly upward or diagonally upward at a desired angle. In that case the lift cylinders 8 may be driven to their other extreme positions with the piston rods 13 pushed out of the cylinder bodies 14.
• the tubular first locking member 10 When inside the tubular first locking member 10, the piston rods 13 are out of sight but, for the sake of clarity, Figure 4 shows with a broken line the piston rod of the right-hand side lift cylinder.
• the tubular first locking member 10 has its top part fastened to the outermost end of the piston rod 13 and therefore it moves with the piston rod 13 and in relation to the cylinder body 14.
• the first locking member 10 and the cylinder body 14 have suitable guide surfaces between them to allow the first locking member 10 to slide on the cylinder body 14 when the length of the lift cylinder 8 is changed.
• the top part of cylinder body 14 is further provided with a second locking member 15 which may comprise a rotationally non-symmetric outer shape, for example a substantially square shape.
• the second locking member 15 may be immovably fastened to the cylinder body 14.
• the cross-section of the inner surface of the tubular first locking member 10 may have a rotationally non-symmetric shape corresponding to the outer shape of the second locking member 15.
• the bottom part of the first locking member 10 is provided with a separate piece fastened to the tubular part and provided with a shape corresponding to the outer shape of the second locking member 15.
• the first locking member 10 is arranged to rotate about its longitudinal axis in direction E for a predetermined limited angle by means of a turning device 16.
• the turning device 16 may be a hydraulic cylinder, for example, coupled between the first locking members 10 of two adjacent lift cylinders 8, which allows it to rotate both the locking members 10 simultaneously although in opposite directions.
• the first locking member 10 When the boom is raised to the operation position A, the first locking member 10 may be turned from the released position to the locking position, a shape-locking being thus formed between the locking members 10 and 15, and the first locking member 10 is no longer capable of extending onto the second locking member 15.
• This provides a firm mechanical locking between the locking members 10 and 15 belonging to the locking device 17, the locking preventing retraction of the lift cylinder 8 and lowering of the boom.
• the locking device 17 thus forms a security locking, which prevents unintentional lowering of the boom due to faults and damages, for example.
• the lift cylinder 8 When the boom is to be lowered, the lift cylinder 8 may be extended a little to reduce friction between the locking mem- bers 10 and 15.
• the first locking member 10 may again be rotated to the released position so that it sets into a matching position with the second locking member 15. The first locking member 10 is thus able to move again past the second locking member 15 towards the bottom end of the lift cylinder 8.
• the length of the first locking member 10 and the position of the second locking member 15 are selected so that when they are in the locking position, distance L between the fastening members 1 1 and 12 of the lift cylinder 8 matches to the desired operating position A of the boom part 3a. It is also possible to arrange two or more operating positions for the boom part 3a.
• Figure 4 shows with broken lines alternative locking members 15a belonging to the locking device 17, the locking members being located at a distance from the locking members 15 at the top of the cylinder tube 14. This allows the lift cylinder 8 to be locked to an alternative second length with the locking members 15a.
• coupling to the locking position in the second locking position cannot be based on the rotation of the first locking member 10, but the operation of the locking members 15a may be based on some other locking principle.
• Figure 5 shows the lift cylinder 8 in the locked position and in the released position.
• the lift cylinder 8 on the left has been locked to the operating position by rotating the first locking member 10 belonging to the locking device 17 in direction E in relation to the second locking member 15, which is fixedly fastened to the top of the cylinder body 14.
• the first locking member 10 may comprise an elongated tube part 10a that may have a planar end piece 10b, known as a coulisse, at the bottom end thereof.
• the end piece 10b is provided with an opening 10c whose shape substantially corresponds to the shape of the outer surface of the second locking member 15.
• first locking member 10 This allows the first locking member 10 to be rotated about its longitudinal axis to a released position, where the opening 10c and the second locking member 15 fit together, and to a locking position, where the end surfaces of the end piece 10b and the second locking member 15 are against one another.
• the shape of the inner side of the cross-section of the tube part 10a may substantially correspond to the shape of the second locking member 15 to allow it to rest on the second locking member 15 when the tube part 10a has slid onto the cylinder body 14.
• the bottom end of the first locking member 10 may be provided with a guide sleeve 10d or a similar guide surface that may be supported to the outer surface of the cylinder body 14 by slide pieces 10e or similar guide pieces.
• the guide sleeve 10d and its guide pieces 10e may hold the first locking member 10 parallel with the longitudinal axis of the lift cylinder 8 after the lift cylinder 8 has been extended and the end piece 10b has moved above the second locking piece 15. This ensures that the locking members 10 and 15 are parallel with the longitudinal axis of the lift cylinder 8 and one may penetrate into the other when the locking device 17 has been rotated to the released position.
• the second locking member 15 may be a planar piece with a rotationally non- symmetric outer surface presenting a substantially square shape, for example.
• the locking device 17 on the right is in the released position and the first locking member 10 has slid onto the cylinder body 14 because the lift cylinder 8 has been retracted.
• the slide pieces 10e rest against the cylinder body 14 and hold the first locking member 10 parallel with the longitudinal axis of the lift cylinder 8.
• the slide pieces 10e may be of a suitable slide bearing material, such as plastic suitable for the purpose.
• Figure 6 shows the operation of the locking device 17 as seen the direction of the piston rod of the lift cylinder.
• Locking devices 17a and 17b of adjacent lift cylinders are operated with the same rotating device 16, whose linear movement D is transmitted by lugs 18 to a rotating movement of the first locking member 10.
• the opening in the end piece 10a of the first locking member 10 and the second locking member 15 fit together, the locking devices 17a and 17b being in the released position.
• the lugs 18' move outward to the position shown with a broken line and the first locking member 10 rotates to the locking position.
• the rightmost partial figure shows a locking device 17c in the locking position. In that case the second locking member 15 and the end piece 10b are interleaved and the inward movement of the piston rod is prevented.
• the second locking member 15 may be rotated in relation to the cylinder body 14 by a suitable rotating motor, for example, or by some other actuator.
• a suitable rotating motor for example, or by some other actuator.
• the first locking member 10 is coupled to the piston rod 13 and arranged to move in relation to the cylinder body 14 when the lift cylinder 8 is extended or retracted.
• One or more sensors 30 may be provided in association with the locking device 17 to enable the locking position and the released position of the locking device 17 to be detected. This detection data may be transmitted to one or more control units 31 of the personnel hoist. The control unit 31 may prevent the moving and normal use of the boom until data of a detected locking has been received. This embodiment is illustrated in Figure 4.
• the top end of the tubular first locking member 10 may be provided with sealing members 32. Since the structure of the first locking member 10 is an impermeable flange sealed at the top end, entry of dirt and water to the lift cylinder 8 can be effectively prevented. This is advantageous in rescue operations in particular, because it enables to avoid freezing of the cylinder 8 due to extinction water.
• the bottom end of the first locking member 10 may be airing, i.e. the bottom end may be open 33 and comprise a gap or openings to allow impurities that have entered the locking member 10 and water entered or condensed there to leave the structure. This improves the strength and reliability of the construction.
• a further point to be mentioned is that it is possible to arrange a first locking member 10 which is moved with a separate actuator, in which case the locking member is driven to the locking position by means of an actuator after the lift cylinder has be driven to its predetermined position where the locking is to take place.
• the actuator for moving the first locking member may be a pressure medium cylinder or motor, for example.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Physics & Mathematics (AREA)
• Fluid Mechanics (AREA)
• General Engineering & Computer Science (AREA)
• Forklifts And Lifting Vehicles (AREA)
• Actuator (AREA)

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Publications (1)

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Family Applications (1)

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• 2010
  • 2010-04-14 FI FI20105387A patent/FI122539B/fi active IP Right Grant
• 2011
  • 2011-04-14 EP EP11768513.1A patent/EP2558403B1/en active Active
  • 2011-04-14 PL PL11768513T patent/PL2558403T3/pl unknown
  • 2011-04-14 ES ES11768513.1T patent/ES2552434T3/es active Active
  • 2011-04-14 WO PCT/FI2011/050331 patent/WO2011128510A1/en active Application Filing

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