Classifications

• • E—FIXED CONSTRUCTIONS
  • E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
  • E01D—CONSTRUCTION OF BRIDGES, ELEVATED ROADWAYS OR VIADUCTS; ASSEMBLY OF BRIDGES
  • E01D19/00—Structural or constructional details of bridges
  • E01D19/10—Railings; Protectors against smoke or gases, e.g. of locomotives; Maintenance travellers; Fastening of pipes or cables to bridges
  • E01D19/106—Movable inspection or maintenance platforms, e.g. travelling scaffolding or vehicles specially designed to provide access to the undersides of bridges
• • 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

Definitions

• the invention relates to a person lifting device comprising an articulated boom mounted at its one end to an underframe turnably about a first horizontal axis, the articulated boom being formed by a lifting boom and an extension boom which is connected to form an extension of the lifting boom and to turn about a second horizontal axis parallel with the first hori- zontal axis; a working platform connected to one end of the extension boom turnably about a third hori ⁇ zontal axis parallel with the other horizontal axes; and control means for maintaining the working platform automatically substantially horizontal when the lift- ing boom and the extension boom are turned about the horizontal axes.
• Person lifting devices are required to perform various tasks at great heights or when there is no other working platform or space or it is unreasonably expensive and difficult to build one for temporary use.
• Person lifting devices presently in use typically comprise an underframe which may be a separate trailer as well as a vehicle, such as a truck.
• So-called self- propelled devices having a motor-driven underframe with steering means may also be used as underframes in person lifting devices.
• Person lifting devices typically comprise a boom attached to the underframe rotatably about a vertical axis and arranged to be turned about a horizontal axis into different posi- tions in the vertical direction.
• the boom may also comprise one or more boom portions interconnected by means of horizontal shafts so that the location and position of the boom can be altered in different ways.
• the boom may also be telescopically extensible and retractable.
• a working platform is attached hori- zontally to the end of the outermost boom portion, and the articulations between the boom portions as well as the structure of the boom portions are such that the bottom of the working platform will always remain horizontal irrespective of the turning of the boom portions with respect to each other.
• Such parallel automatism is typically realized either by mechanical supporting bars on a so-called rhombus principle or by a sprocket-and-chain structure or hydraulic control means.
• DE Patent Specification 1 007 043 discloses a working carriage for use in docks. It comprises a vertical mast to which working platforms are attached rotatably about the mast. It also comprises one tele- scopically extensible mast portion to which a working platform is also attached so as to be vertically dis- placeable with respect to the other platforms.
• the solution is usable in certain kind of structures where the dimensions and mutual position of the platforms as well as the working conditions are fully known in advance. However, the solution cannot usually be applied when working at great heights in varying conditions.
• DE Patent Specification 1 907 408 in turn discloses a similar working platform structure where three vertically movable telescopic masts are attached to the same underframe, and a single platform or alternatively a lifting device is attached to the masts. This solution is usable when working at relat ⁇ ively small heights in connection with fully vertical walls, whereas it cannot be used when working at greater heights or when the surface is inclined or the persons positioned on the platforms should be able to reach to different heights.
• the object of the present invention is to provide a person lifting device which avoids the restrictions of the prior art solutions and allows working in widely varying conditions.
• the person lifting device according to the invention is char ⁇ acterized in that a second working platform is con ⁇ nected to the articulated boom at a distance from the first working platform turnably about a horizontal axis parallel with the other horizontal axes, and control means are provided for maintaining the second working platform substantially horizontal when the lifting boom and the extension boom are turned about the horizontal axes.
• the articulated boom of the person lifting device comprises two working platforms which can be posi ⁇ tioned either vertically on top of each other, or vertically out of line with each other for an inclined surface, so that the work can be done from both work- ing platforms.
• An essential feature of the preferred embodiment of the invention is that the articulated boom and its portions are telescopically adjustable in length, so that the position and distance of the work ⁇ ing platforms can be adjusted as desired, and the working conditions will always be optimal.
• An advantage of the person lifting device according to the invention is that the work can be done by persons positioned at two different heights and in such a way in the vertical direction and in the direction of inclination that any work can be done or that the work can be done by utilizing a single person lifting device.
• Another advantage of the solution according to the invention is that, if required, it is possible to use only one of the working platforms when the platform positioned at the articulation is made easily detachable and attachable; in cases where the platform is attached more fixedly, preferably the outermost platform only is used.
• the person lifting device according to the invention is also advantageous to manufacture and versatile in use.
• Figure 1 is a schematic view of a person lifting device according to the invention and its articulated boom in two positions;
• Figure 2 is a partial schematic view of another embodiment of the person lifting device according to the invention and the articulated boom.
• FIG 1 shows schematically a person lifting device according to the invention and its underframe and articulated boom in two different positions.
• the person lifting device comprises an articulated boom 1 including a lifting boom 2 and an extension boom 3 attached to it.
• a first working platform 4 is attached in a manner known per se to the end of the extension boom 3.
• the lifting boom 2 comprises boom portions 2a to 2c telescopically movable with respect to each other, and so the length of the lifting boom 2 can be adjusted in a desired manner.
• the extension boom comprises boom portions 3a and 3b telescopically movable with respect to each other in a manner known per se.
• the lifting boom 2 is attached to a stand 5 turnably about a horizontal axis 6 so that it can be turned in the vertical direction by power means known per se and therefore not shown.
• the stand 5 in turn is connected to an underframe 7 rotatably about a vertical axis 8 indicated by a broken line so that the direction of movement of the entire articu- lated boom can be changed in a desired manner.
• the underframe 7 in turn stands on the ground on support feet 9 in a working situation so that the underframe will remain in a fully horizontal position, and its support points will be positioned at the greatest possible distance from the turning axis 8.
• the extension boom 3 is attached at its end to the end of the lifting boom 2 turnably about a second horizontal axis 10 parallel with the first horizontal axis 6, and it can be turned with respect to the lift- ing boom 2 by power means known per se (not shown) .
• a third horizontal axis 11 runs in parallel with the horizontal axis 6, and the working platform 4, drawn as a lifting cage in the figure, is connected with respect to the lifting boom 2 and the stand 5 by parallel means, i.e. control means known per se, so that when the extension boom 3 is turned with respect to the lifting boom 2, or the lifting boom 2 is turned with respect to the stand 5, the working platform 4 will always remain in the hori ⁇ zontal position.
• a second working platform 12 is further connected to the boom portion 3a of the extension boom 3, that is, to the boom portion on the side of the lifting boom 2, in the figure the upper boom portion, turnably about a fourth horizontal axis 13 parallel with the axes 6 and 10.
• the second plat ⁇ form is connected to the boom portion 3a of the extension boom 3 in a known manner by utilizing control means such that the platform 12 will always remain horizontal within the area defined by the range of movement of the lifting boom 2 and that of the extension boom 3 irrespective of the movements of the booms.
• Horizontal displacing means 14 are further provided between the second working platform 12 and the extension boom 3. They comprise a track structure and transmission power means known per se, by means of which the second working platform 12 can be displaced outwards to some extent with respect to the extension boom 3 so that the working platform 12 will reach farther outward than the first working platform 4, to the left in the figure.
• Figure 1 also shows the second position of the articulated boom 1 of the person lifting device according to the invention, i.e. a position in which the articulated boom 1 has been turned to the lowest possible position.
• the first working platform 4 will reach considerably below the under ⁇ frame 7 so as to enable working in pits and excavat- ions.
• the numerals indicating this position of the articulated boom 1 are furnished with an apostrophe, i.e. 1', etc., and they indicate the same components as the numerals without an apostrophe.
• extension boom 3 is shown in a substantially vertical position, but a suitable shap ⁇ ing allows it to be turned into different positions with respect to the lifting boom 2. For instance, the extension boom 3 can be turned farther to the right from the position shown in the figure, i.e. such that it will slant inwards, provided that the position of the upper working platform and its connection to the articulated boom are such that the protective rail of the working platform will not hit the articulated boom.
• Figure 2 shows schematically the second embodi ⁇ ment of the invention, in which the range of movement of the extension boom 3 is such that, if required, the extension boom 3 can be turned so that it forms an extension of the lifting boom 2 in order that higher places could be reached by one working platform; cor ⁇ respondingly, when the extension boom 3 has been turned downward, the two working platforms can be used simultaneously.
• the second working platform 12 is mounted at the end of the lifting boom 2 rotatably about a fourth hori ⁇ zontal axis 13" so that it will remain in the hori ⁇ zontal position irrespective of the position of the lifting boom 2.
• the second working platform 12 which is displaceable by horizontal dis- placing track means 14, can be displaced backward above the lifting boom 2 when the extension boom 3 is to be turned upward.
• the first working platform 4 can thereby be lifted above the lifting boom 2 so that it forms an extension of the extension boom 3, and so the entire length of the boom can be utilized while using one platform.
• a separate auxiliary boom 3" is provided between the lifting boom 2 and the dis ⁇ placing means 14 of the second working platform, and a fifth horizontal axis 15 parallel with the fourth horizontal axis 13" runs through one end of the boom 3". This, however, is not necessary, but the second working platform 12 may as well be mounted turnably about a single horizontal axis.
• the invention has been described above and shown in the drawings only by way of example, and it is not in any way limited to the example.
• An essential feature of the invention is that the first working platform is mounted to the outer end of the extension boom 3 forming an extension of the lifting boom 2, and the second working platform 12 is attached to the extension boom or the lifting boom close to the turn ⁇ ing axis between the lifting boom 2 and the extension boom 3 in such a manner that the two working platforms that always remain horizontal can be positioned on top of each other in the vertical direction. Persons posi ⁇ tioned on the working platforms will be able to work together in difficult conditions.
• the length of the extension boom 3 is telescopically adjustable so that the distance between the working platforms can be varied in accordance with the working conditions in the best possible way.
• the lifting boom 2 may be a telescopic boom or any other suitable boom structure, such as an articulated boom or a combination of dif ⁇ ferent structures.
• the second working platform 12 is connected to the end of the lifting boom 2 such that it can be displaced aside to allow the first working platform to be lifted by means of the extension boom 3 so that it forms an extension of the lifting boom 2 in order to provide the largest possible operating range in difficult conditions.

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• Engineering & Computer Science (AREA)
• Structural Engineering (AREA)
• Life Sciences & Earth Sciences (AREA)
• Geology (AREA)
• Mechanical Engineering (AREA)
• Architecture (AREA)
• Civil Engineering (AREA)
• Forklifts And Lifting Vehicles (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8538934

Family Applications (1)

Country Status (5)

Cited By (4)

Families Citing this family (2)

Citations (5)

• 1993
  • 1993-11-11 FI FI934984A patent/FI92813C/fi not_active IP Right Cessation
• 1994
  • 1994-04-19 DE DE4498649T patent/DE4498649T1/de not_active Ceased
  • 1994-04-19 WO PCT/FI1994/000147 patent/WO1995013242A1/en active Application Filing
  • 1994-04-19 GB GB9608529A patent/GB2298184B/en not_active Expired - Lifetime
  • 1994-04-19 AU AU64316/94A patent/AU6431694A/en not_active Abandoned

Patent Citations (5)

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