EP2984026A1

EP2984026A1 - Boom and personnel hoist

Info

Publication number: EP2984026A1
Application number: EP14782843.8A
Authority: EP
Inventors: Kari Raitmaa; Jarmo Niemi; Juho LEHTINEN; Pertti TAPIAINEN
Original assignee: Bronto Skylift Oy AB
Current assignee: Bronto Skylift Oy AB
Priority date: 2013-04-11
Filing date: 2014-04-10
Publication date: 2016-02-17
Anticipated expiration: 2034-04-10
Also published as: EP2984026A4; FI20135363A; FI126628B; ES2699577T3; PL2984026T3; WO2014167188A1; EP2984026B1

Abstract

The invention relates to a boom and personnel hoist. The boom (3) comprises at least one elongated boom part (9), the cross-sectional profile of which comprises a top (10), two sides (11), and a bottom (12). The sides comprise at least three sections (20, 21, 22) and corners (N) between them. The bottom parts of the sides are wider than the top parts. The bottom comprises at least five sections (23 to 26) and corners between them. This type of boom and boom part may be in a personnel hoist (1).

Description

Boom and personnel hoist

Background of the invention

[0001] The invention relates to a boom that is an elongated piece and comprises at least one elongated boom part. The cross-sectional profile of the boom part comprises a top, two opposite sides, a bottom, and corners between these.

[0002] The invention further relates to a personnel hoist.

[0003] The field of the invention is described in more detail in the preambles of the independent claims of the patent application.

[0004] Elongated booms are used in various work machines and movable devices. The boom is movably connected to a carrier and its outermost end usually has a work device. The boom may be quite long, which is why the deadweight of the boom may be great. Typically the cross-sectional profile of the boom is substantially a rectangle, often an oblong. A drawback in the present booms is that the ratio between stiffness and weight is unsatisfactory.

Brief description of the invention

[0005] It is an object of the present invention to provide a novel and improved boom and a personnel hoist equipped with a boom.

[0006] The boom of the invention is characterised in that the cross- sectional profile of the boom part comprises at least three profile components that are fastened to each other by longitudinal seams, and the seams between the profile components are at a distance from the corners of the boom part.

[0007] The personnel hoist of the invention is characterised in that the boom of the personnel hoist is in accordance with claim 1.

[0008] The idea of the present solution is that, the boom comprises at least one boom part, the cross-sectional profile of which has a top, two opposite sides, and a bottom opposite the top. The sides are at a greater distance from each other and the centre line of the boom part at the bottom-side end than at the top-side end. In addition, the sides comprise at least three planar surfaces and corners between them. Further, the bottom of the boom part cross-section is trough-shaped in such a manner that it has at least five planar surfaces and corners between them. In the middle of the bottom, there is a centre part and, on both sides thereof, obliquely upward directed planar sec- tions as well as sections that are parallel to the centre part and connect with the sides of the cross-sectional profile.

[0009] An advantage of the present solution is that the cross-section of the boom part has a large number of corners that stiffen the structure. In addition, the corners divide at least the sides and bottom into sections so they have relatively small uniform surface areas. This way, it is possible to prevent the surfaces from buckling. When the bottom parts of the sides widen outward, the sideward stiffness of the boom part as well as the rotational stiffness can be increased. All in all, the present solution provides good stiffness in relation to the mass.

[0010] The idea of an embodiment is that, in the operational position of the boom part, the sides move on the vertical plane. The top of the boom part forms the top part of the cross-sectional profile and the bottom forms the bottom part of the profile. The upward direction then means toward the top and the downward direction means toward the bottom.

[0011] The idea of an embodiment is that both sides of the boom part comprise three planar surfaces and corners between them. Highest up, i.e. closest to the top, there is a vertical top part. Lowest down, i.e. closest to the bottom, there is a vertical bottom part. The top and bottom parts may be parallel. The bottom part is at a greater horizontal distance away from the centre line of the boom part. The profile is then wider at the bottom. Between the top and bottom parts of the side, there is an oblique section.

[0012] The idea of an embodiment is that the bottom of the boom part is trough-shaped in such a manner that the inner surface side of the bottom is concave and its outer surface side is convex. The bottom comprises several planar surfaces that are connected to each other by longitudinal corners. Instead of large surfaces, the bottom then has several smaller surfaces with a smaller buckling susceptibility than that of large surfaces. In addition, the bottom has several corners that stiffen the structure. Compression stress is directed to the bottom of the boom part during use and tries to bend the bottom and its parts toward the inside of the profile. This buckling of surfaces can be effectively avoided with the disclosed structure.

[0013] The idea of an embodiment is that the bottom of the boom part comprises at least five planar surfaces and corners between them. There are five planar surfaces on both the outer surface side and the inner surface side of the bottom. A centre part is in the middle of the bottom and on both sides thereof, there are two obliquely upward directed oblique sections with edge sections extending from them. The centre part of the bottom may be horizontal like the edge sections on the edges of the bottom.

[0014] The idea of an embodiment is that the bottom of the boom part comprises at least seven planar surfaces and corners between them. There are seven planar surfaces on both the outer surface side and the inner surface side of the bottom. A centre part is in the middle of the bottom and on both sides thereof, there are two obliquely upward directed oblique sections at different angles and edge sections extending from them. The centre part of the bottom may be horizontal like the edge sections on the edges of the bottom.

[0015] The idea of an embodiment is that the edges of the boom part bottom have the above-mentioned edge sections with horizontal planar surfaces on the inner surface side and the outer surface side of the boom part. These planar surfaces of the edge sections are utilised as support surfaces that may receive loads from other boom parts on the outer side and inner side of the boom part. The support surface can be equipped with a slide piece, such as a slide block or rod, that may be made of a suitable slide bearing material.

[0016] The idea of an embodiment is that the horizontal edge section of the boom part bottom connects through a rectangular corner to the vertical bottom part of the profile side. The profile then comprises two orthogonal corners that are at the greatest possible horizontal distance from each other on the profile. These corners act as efficient stiffeners in the structure.

[0017] The idea of an embodiment is that the boom part comprises several elongated profile components fastened to each other. The boom part is formed of more than two profile components that have differing cross-sectional profiles. The profile components that are fastened to each other by longitudinal seams form together the cross-sectional profile of the boom part. The length of each profile component corresponds to the length of the boom part. When the boom part is formed of several profile components, it is easier to manufacture. The structure also permits diverse modification of the boom part for different applications.

[0018] The idea of an embodiment is that the boom part comprises at least four profile components fastened to each other by longitudinal seams. The cross-sectional profile of the boom part may then have one top profile component, two side profile components and one bottom profile component. [0019] The idea of an embodiment is that the boom part comprises at least four profile components fastened to each other by longitudinal seams. The seams between the profile components are at a distance from the two top corners and the two bottom corners of the boom part. The corners between the top and sides as well as the corners between the bottom and sides are without seams. Slide pieces can be arranged at the top and bottom corners of the boom part, in which case it is advantageous not to have seams in the corners. The side surfaces of the corners may act as slide surfaces on both the inner surface and outer surface side of the boom.

[0020] The idea of an embodiment is that the boom part comprises six longitudinal profile components fastened to each other. The cross-sectional profile of the boom part may then have one top profile component, two side profile components, two corner profile components and one bottom profile component. This embodiment makes it possible to vary the boom part in many ways,

[0021] The idea of an embodiment is that the boom part comprises several profile components fastened to each other. The properties of the boom part can be influenced by the selection of the profile components without changing the basic shape of the boom part cross-section. For instance, it is then possible to increase or decrease the wall thickness of each profile component. Further, it is possible to influence the strength and other properties of the boom part by the selection of the material of the profile component. For instance, it is then possible to select structural steels having different strength classes for use in different profile components. This embodiment permits the tailoring of the boom part for each device.

[0022] The idea of an embodiment is that the boom part comprises two or more profile components, the materials of which have different strength properties. The materials may be of the same basic material, such as steel, but their strengths may be different due to alloying, thermal treatment, deformation or some other matter. The cross-sectional profile of a boom part made of steel, for instance, may comprise two or more sections having different strength classes.

[0023] The idea of an embodiment is that the boom part comprises two or more profile components that are made of different basic materials. For instance, the cross-sectional profile of the boom part may then have a section made of steel and a section made of aluminium or composite metal. Between the profile components made of different basic materials, there are longitudinal seam surfaces that may be fastened to each other by gluing, screws or rivets, for instance, if they cannot be welded together.

[0024] The idea of an embodiment is that the boom part comprises two or more profile components, the wall thicknesses of which differ from each other.

[0025] The idea of an embodiment is that the boom part comprises several profile components connected to each other by seams. The boom part then has at least a top profile, two side profile components and a bottom profile component, each having a wall thickness. The wall thickness of the bottom profile component is larger than those of the side and top profile components. When loading the boom part, compression stress is directed to the bottom profile component, which is why its walls are made thicker than in the other profile components of the boom part.

[0026] The idea of an embodiment is that the boom part comprises several profile components connected to each other by seams. The boom part then has at least a top profile, two side profile components and a bottom profile component. Each profile component is a uniform piece made of one material. The profile components then have no seams. The profile components comprise planar surfaces with corners between them, the corners being without seams.

[0027] The idea of an embodiment is that the boom part comprises two or more profile components. The cross-sectional profile of the boom part is asymmetric in such a manner that the side profile components forming the opposite sides of the profile differ from each other. The wall thickness or material properties, such as strength values, of the side profile components may be different. This embodiment may be used when an uneven load is directed to the boom. For instance, in a personnel hoist, a personnel cage and its auxiliary boom may be fastened by turning members to one side of the boom, in which case an asymmetric load is directed to the boom. Due to the component structure of the boom part, there is no need to use separate additional stiffeners fastened to the sides of the boom part.

[0028] The idea of an embodiment is that the profile components of the boom part are formed by roll forming. When using several profile components that are fastened to each other in the assembly, the shape of an individual profile component may be relatively simple and open. Manufacturing profile components of this type by roll forming is fast and cost-efficient. In addition, roll forming produces dimensionally accurate and good-quality elongated pieces that comprise bends.

[0029] The idea of an embodiment is that the profile components of the boom part are formed by roll forming of one material, and they comprise several planar surfaces and corners between them. The roll-formed profile component is then one uniform piece without seams.

[0030] The idea of an embodiment is that the side view of the boom part differs on one planar surface. When examining the boom part from the side, there are at least six longitudinal corners or bends visible. The corners stiffen the structure and divide the surface into smaller sections to avoid buckling. The side view comprises several smaller buckling fields, the buckling susceptibility of which is smaller than that of a large surface or area.

[0031] The idea of an embodiment is that the bottom view of the boom part differs on one planar surface. When examining the boom part from the bottom, there are at least eight longitudinal corners or bends visible. The corners stiffen the structure and divide the surface into smaller sections to avoid buckling.

[0032] The idea of an embodiment is that the top of the boom part comprises at least three planar surfaces and longitudinal corners between them. In the middle of the top, there is a horizontal planar surface, and on the sides, oblique sections directed downward at a small angle. In comparison with the bottom, the angles of the oblique surfaces of the top are clearly smaller than those of the oblique surfaces of the bottom.

[0033] The idea of an embodiment is that the boom is a telescope boom that can be extended and shortened. The boom then has a fixed boom part and at least one movable boom part arranged at least partly inside the fixed boom part. The movable boom part can also be moved in relation to the fixed boom part, when the boom is loaded.

[0034] The idea of an embodiment is that between at least two nested boom parts, there is at least one longitudinal device space. Mechanisms required to move the boom parts, for instance, can be arranged in the device space. Further, hydraulic pipes or channels, electric cables or other means intended for transmitting energy or medium can be arranged in the device space. The profile shape described above makes it possible to provide sufficiently large device spaces into the structure. [0035] The idea of an embodiment is that the length of the boom part is over 8 metres, typically 8 to 14 metres.

[0036] The idea of an embodiment is that the boom is the boom of a personnel hoist. The lower end of the personnel hoist boom is fastened to a turning frame or corresponding fastening point on a movable carrier. The upper end of the boom has a personnel cage. The boom of a personnel hoist should be movable under load, which is why the cross-section of the boom part must also retain its shape under load.

[0037] The above embodiments and the related features can be combined to provide desired embodiment and feature combinations as necessary.

Brief description of the drawings

[0038] Some embodiments are explained in more detail in the accompanying drawings, in which

Figure 1 is a schematic side view of a personnel hoist that comprises a movable carrier and a boom connected to it,

Figure 2 is a schematic side view of a boom provided with a personnel cage,

Figure 3 is a schematic view of the cross-section of a boom part, Figure 4 is a schematic and perspective view of the boom part of

Figure 3,

Figure 5 is a schematic view of the cross-section of a boom part with several profile components,

Figure 6 is a schematic view of the cross-section of a boom part, in which the bottom is made of material with a greater wall thickness than those of the other sections,

Figure 7 is a schematic view of the cross-section of a boom part, in which the wall thicknesses of the sides differ from each other, and

Figure 8 is a schematic view of a boom with several boom parts arranged inside each other to provide a telescopic boom.

[0039] For the sake of clarity, the figures show some embodiments in a simplified manner. In the figures, like reference numerals identify like elements. Detailed description of some embodiments

[0040] Figure 1 shows a personnel hoist 1 that comprises a movable carrier 2 and a boom 3 arranged on it. The boom has several boom parts 9, that are partly inside each other and that may be moved in relation to each other so that the boom 3 can be extended and shortened. One end of the boom 3 is connected to the carrier 2 with a turning frame 5. The other end of the boom 3 has a personnel cage 6. The boom 3 can be moved in a versatile manner up, down and to the side so that the personnel cage can be positioned in a desired place. The length of the boom 3 can be altered while the personnel cage 6 is loaded. The boom 3 may be extendable to be very long, so it should have good stiffness in relation to weight. The boom 3 and boom part 9 described in this patent application can be utilised in a personnel hoist 1 similar to that in Figure 1 , for example.

[0041] Figure 2 shows that the boom 3 may comprise a lower boom 3a and an upper boom 3b that are coupled together with a joint 7. At the lower end of the boom 3, there is also a joint 8 for lifting and lowering the boom 3. The boom 3 can be turned sideways by means of the turning frame 5. The lower boom 3a and the upper boom 3b comprise at least two boom parts 9, of which at least one is a fixed boom part 9a and at least one is a telescopically movable boom part 9b. The boom parts 9 are generally quite long, typically 10 to 12 metres in length. The boom parts 9a, 9b may be as described in this patent application.

[0042] Figure 3 shows the cross-sectional profile of a boom part 9 that comprises a top 10, two opposite sides 11 and a bottom 12 with corners NU and NL between them. Sides 11 comprise three planar surfaces T with corners N between them. The sides 11 widen outward at the bottom 12 side end, in other words, the bottom parts of the sides on the bottom side are at a longer horizontal distance L2 from the centre axis 13 than the top parts of the sides 11. The bottom 12 is, in turn, trough-shaped. The bottom 12 may have seven planar surfaces T with corners N between them. Thus, the structures of the sides 11 and bottom 12 have a large number of corners N that stiffen the structure. In addition, the planar surfaces T in them are small to prevent buckling. The bottom 12 has external horizontal planar surfaces T1 and corresponding internal planar surfaces T2 that may act as support surfaces between the boom parts that are arranged inside each other. Slide pieces can be ar- ranged against these support surfaces T1 , T2, as illustrated later on in Figure 8.

[0043] Figure 3 also shows that the top 10 may comprise several planar surfaces T and corners N between them.

[0044] Figure 4 is a perspective view of the boom part 9. Each side 11 of the boom part 9 comprises three planar surfaces and corners between them. Highest up is a vertical top part 20. Lowest down is a vertical bottom part

21. The top part 20 and bottom part 21 may be parallel. In some cases, the top part 20 and the bottom part 21 may be at a slight angle to the vertical. The bottom part 21 is at a greater horizontal distance from the centre line of the boom part. Between the top 20 and bottom 21 parts, there is then an oblique section

22. The bottom 12 of the boom part 9 is trough-shaped in such a manner that the inner surface side of the bottom is concave and the outer surface side is convex. In the middle of the bottom 12, there is a centre part 23 and on both sides thereof, there are two obliquely upward directed oblique parts 24 and 25 and edge sections 26 extending from them. The centre part 23 of the bottom may be horizontal like the edge sections 26. In the middle of the top 10 of the boom part 9, there is a horizontal planar surface 27 and, on the sides, oblique sections 28 directed downward at a small angle.

[0045] Figure 5 shows that the cross-section of the boom part 9 may comprise several profile components 14 that may be fastened to each other by seams S. The seams S are longitudinally to the boom part 9. The seams S may be welds, for instance. Further, the seams S may be butt seams. The top 10 of the boom part 9 may be formed of a top profile component 14a. The sides 11 may be formed of side profile components 14b and 14c. The bottom 12 may be formed of a bottom profile component 14d. Further, there may be corner profile components 14e and 14f between the sides 11 and bottom 12. All in all, the profile of the boom part 9 may comprise six profile components 14a to 14f joined together. In such a case, there are also six seams S. As can be seen in Figure 5, the seams S are positioned at a distance from the corners NU and NL, which is advantageous for strength. The top profile component 14a may then have vertical sections 29 that extend to the side 11. Further, the corner profile components 14e and 14f may have sections 30 that extend toward the oblique sections 25 of the bottom profile component 14d. At the top corners NU and bottom corners NL, there may be slide surfaces GS on both the inner surface side and the outer surface side of the profile. Slide pieces may be positioned against these slide surfaces.

[0046] Figures 6 and 7 illustrate the fact that the wall thicknesses of the boom part 9 top 0, sides 11 and bottom 12 formed of profile components may differ in size from each other, if necessary. In Figure 6, the wall thickness W1 of the bottom 12 has been made larger by means of the bottom profile component. In addition, the wall thickness W2 of the top 10 is dimensioned to be smaller than the wall thickness W3 of the sides 11. Figure 7 shows that the structure may be asymmetrical in relation to the centre line C in such a manner that the wall thicknesses W4 and W5 of the opposite sides 11 differ from each other. It is possible to use not only different wall thicknesses, but also profile components that differ in strength, material and other properties to achieve as good a ratio between stiffness and weight as possible for each requirement. For the sake of clarity, Figures 6 and 7 do not show the seams between the profile components. However, the seams are positioned away from the area of the top corners NU and bottom corners NL of the boom part.

[0047] Figure 8 is a strongly simplified view of the structure of a boom 3. The boom 3 comprises five boom parts 9a to 9e inside each other. Naturally, there may be fewer or even more boom parts, for example 7. The outermost boom part 9a is a fixed boom part, in relation to which the moving boom parts 9b to 9e can move horizontally. A few slide pieces 15 that may be supported against the support surfaces on the bottoms of the boom parts are marked in Figure 8. There may also be slide pieces 16 between the tops of the boom parts. The slide pieces may be corner pieces 15a, 16a, in which case their cross-sectional profile resembles the letter L. These corner parts can be used, when there are no seams in the corners NU and NL of the boom parts. In the boom parts, the seams are positioned away from the slide surfaces that come against the slide pieces. The side profile components can be dimensioned in such a manner that required device spaces 17 for moving mechanisms remain between the boom parts. Further, the bottom profile components can be dimensioned in such a manner that required device spaces 18 are provided for cables, hoses and corresponding energy supply means. When the structure of the boom parts is formed of profile components of the type described above, the device spaces 17 and 18 can be formed relatively easily and without harmfully affecting the stiffness of the structure. In addition, the device spaces 17, 18 can be dimensioned to be sufficiently large, which facilitates the assembly and maintenance of the boom 3.

[0048] In some cases, features disclosed in this application may be used as such, regardless of other features. On the other hand, when necessary, features disclosed in this application may be combined in order to provide different combinations.

[0049] The drawings and the related description are only intended to illustrate the idea of the invention. Details of the invention may vary within the scope of the claims.

Claims

1. A boom that is an elongated piece,

and comprises at least one elongated boom part (9), the cross- sectional profile of which comprises a top (10), two opposite sides (11), a bottom (12), and corners (NU, NL) between them;

and wherein:

the sides (11) of the boom part (9) are at the bottom (12) side end at a greater distance (L2) from each other than at the top (10) side end;

the sides (11) of the boom part (9) comprise at least three planar surfaces (T) and corners (N) between them;

the bottom (12) of the boom part (9) is trough-shaped and comprises a concave inner surface side and a convex outer surface side; and

the bottom (12) comprises at least five planar surfaces (T) and corners (N) between them;

characterised in that

the cross-sectional profile of the boom part (9) comprises at least three profile components (14a to 14f) that are fastened to each other by longitudinal seams (S); and

the seams (S) between the profile components (14a to 14f) are at a distance from the corners (NU, NL) of the boom part.

2. A boom as claimed in claim 1, characterised in that each profile component (14a to 14f) is one uniform piece made of the same material; and

each profile component (14a to 14f) has several planar surfaces, the corners (N) of which do not have seams (S).

3. A boom as claimed in claim 1 or 2, characterised in that the boom part (9) comprises six separately made profile components that are fastened to each other and form the cross-sectional profile of the boom part (9); and

the profile components are: a top profile component (14a), two side profile components (14b, 14c), two corner profile components (14e, 14f) and a bottom profile component (14d).

4. A boom as claimed in any one of preceding claims 1 to 3, characterised in that

the profile components (14a to 14f) are roll-formed pieces.

5. A boom as claimed in any one of preceding claims 1 to 4, characterised in that

the boom part (9) comprises two or more uniform profile components (14) with differing strengths due to different materials.

6. A boom as claimed in any one of preceding claims 1 to 5, characterised in that

the boom part (9) comprises two or more uniform profile components (14) with differing wall thicknesses (W1 to W5).

7. A boom as claimed in claim 6, characterised in that the wall thickness (W1) of the bottom profile component (14d) is greater than the wall thickness (W2) of the side profile components (14b, 14c) and the wall thickness (W3) of the top profile component (14a).

8. A boom as claimed in any one of the preceding claims, characterised in that

the boom (3) comprises two or more boom parts (9a to 9e) inside each other.

9. A personnel hoist,

characterised in that

a boom (3) of the personnel hoist (1 ) is as claimed in claim 1.