A system comprising a movable work platform, as well as an apparatus and a crane device

Abstract

 A system comprising a mast or rail structure (1,24), a movable work platform (2) which is connected to the mast or rail structure; a lifting and lowering device (7), under whose control the work platform can be moved along the mast or rail structure; a movable frame structure (12) which is connected to the mast or rail structure; and an upper support (14) and a lower support (13) which are positioned at a distance from each other in the vertical direction and by means of which the frame structure is connected to the mast or rail structure. Said frame structure extends past the work platform in such a way that the upper support is placed above the work platform and the lower support is placed below the work platform. It also comprises a crane device (11) for manipulating loads and weights, connected to the frame structure.

Description

Field of the invention

[0001] The invention relates to a system comprising a movable work platform and a lifting device for the manipulation of loads and weights. The invention also relates to an apparatus. The invention also relates to crane device.

Background of the invention

[0002] Aerial access platforms, such as elevating work platforms supported by a mast, and structures of them, are known and applied, for example, at various sites of construction and renovation of buildings, as well as when performing various maintenance or repair operations. Work platforms normally comprise a horizontal frame structure, by means of which workers, tools and other equipment and materials needed can be elevated to a desired height for performing work. The work platform is typically solid and elongated, but the work platform may also have a deflected shape, it may comprise protrusions or even have a circular shape, depending on the needs of the worksite. Normally, the work platform has a rectangular shape and the flooring belonging to its frame structure is delimited by safety rails. The workers move on the flooring.

[0003] The work platform is moved along a vertical mast structure comprising of, for example, a lattice structure which normally has a square cross-section. The mast structure remains stationary and it may be free standing, but typically, the mast structure is supported in place by means of fasteners. The mast structure may also be supported at several different points, for example, to a building, by means of fasteners. Yet, the fasteners make it possible that the work platform can move past them up and down along the mast structure. The bottom end of the mast structure may be supported to a particular footing or the like, but the work platform may also be movable, in which case the mast structure stands on a movable base. The movable base is formed, for example, by a carriage on wheels, which can be connected to a hauling vehicle. The bottom part of the mast structure and the work platform are placed on the movable base. The rest of the mast structure can be dismounted and transported separately. Part of the frame structure can also be folded up or even removed, in which case the length of the base to be transported can be reduced. Typically, the movable base comprises several supporting feet whose position can be changed and which support the mast structure when the work platform is in use.

[0004] There may also be several mast structures for a single work platform. It is also possible to connect two work platforms, each comprising one mast structure. In this way, it is possible to provide a larger work area or a greater loading capacity.

[0005] The work platform is moved along the mast structure by means of a lifting and lowering device provided between the mast structure and the work platform, connected to both of them or integrated in the frame structure of the work platform, for example its lifting frame. The lifting and lowering device comprises actuators, for example an electric motor and a transmission that is coupled by means of one or more drive pinions to a gear rack in the mast structure. The pinion ascends along the gear rack, and simultaneously the whole work platform moves along the mast structure. Furthermore, the lifting and lowering device comprises a control system which is also provided with the necessary control means for controlling its operation, for example manually. The control means are normally placed in such a way that a person on the work platform can move the work platform to a desired height or all the way down, wherein it is possible to exit the work platform or load goods.

[0006] If necessary, a single control system can be used for controlling several lifting and lowering devices and for keeping the work platform in balance.

[0007] At construction and renovation sites, it is often necessary to lift and lower various weights or loads. Said weights and loads may be on work platforms or elsewhere, for example on the ground, from where they are lifted and transferred to a desired location. For this reason, the mast structures or movable work platforms are provided with cranes or pivotable boom structures with the necessary equipment for lifting and lowering loads, for example by means of a hoisting wire rope and a hook.

[0008] Some known examples are disclosed, among other things, in document JP 6336823-A, in which the crane is connected to a particular lifting and lowering device, as well as in document WO 03/097509 A1, in which the crane can also be provided with a work platform for the operator of the crane. In addition to this, the same mast structure may be provided with a separate work platform, such as in WO 03/097509 A1, in which the work platform is placed lower than the crane. The crane can also be placed directly on top of the work platform, or connected to the frame structure or integrated in the lifting and lowering device of the work platform, as in documents JP 8208155 A, US 4498556 A and DE 4033492 C2. In FR 2528815 A1, the crane is mounted on top of the lifting and lowering device, and said lifting and lowering device elevates a lift cage which is used for the transportation of workers. The crane is mounted to the mast structure in a movable manner, and it is connected to the lifting and lowering device.

[0009] The weights to be elevated and transferred exert loads on the lifting and lowering device which is also subjected to the load caused by the work platform. In a corresponding manner, by means of the lifting and lowering device, the loads are effective on the mast structure which must bear the loads caused by the crane, the load in the crane, and the loads caused by the work platform, among other things. For example, the structure disclosed in said FR document is supported to the mast structure by means of three supports on top of each other, consisting of rollers. It is obvious that at the middlemost support, a load force is effective that tends to bend both the lifting and lowering device and the mast structure. Reinforcing the structures and increasing the strength often lead to an unnecessary increase in the size of the structure, an excessive weight and extra costs as well as more complex manufacture.

Summary of the invention

[0010] The system according to the invention is presented in claim 1. The apparatus according to the invention is presented in claim 9. The crane device according to the invention is presented in claim 12.

[0011] By means of the presented apparatus, the loads of the mast structure are influenced in such a way that particularly the bending load forces can be reduced. Said apparatus makes it possible that the loads caused by the work platform and particularly the crane are effective at different points of the mast structure and not at the same point, which would be disadvantageous. In particular, it is possible to reduce considerably the load forces transmitted from the apparatus to the work platform, which facilitates the design of the work platform and improves its strength to a great extent. Said load forces are caused by said apparatus, crane, or other weights and loads. The possibilities of varying the work platform remain good, because the apparatus and, for example, the crane can be constructed separately and placed as a system structurally separate from the work platform. It may also be possible to replace the work platform or the apparatus irrespective of each other, if necessary. It is even possible to remove the apparatus totally, if it is unnecessary at the work site, but it is not necessary to remove or replace the work platform. By means of the apparatus, it is even possible to add a crane in old mast structures, and the replacement of the work platform will not be necessary.

[0012] By means of the presented apparatus construction, the support, which consists of, for example, rollers, can be placed as low as possible in relation to the work platform. This has not been possible earlier. The support, mounted far below the work platform, has prevented the lowering of the work platform as low as possible.

[0013] The frame structure utilized in the apparatus is suitable for use not only for cranes but also for other lifting and transfer devices as well as for other purposes, such as merely the transportation and carrying of weights. The weights and loads can also be connected directly to the frame structure. Instead of the crane, it is alternatively possible to connect machines, devices and structures, for example according to the needs at the worksite, even other working levels or work platforms, to the presented frame structure. The frame structure can also be provided with aerial work platforms equipped with a boom. By means of the presented solution, the loads of these are not effective on the work platform but on the mast structure.

[0014] By means of said frame structure, it is even possible to improve work platforms of prior art in such a way that the work platform is supported not only to the mast structure but also to the frame structure. The frame structure transmits load forces to the mast structure by means of its own structure. The connection between the frame structure and the work platform is floating, which enables a sufficient support but also their movement in relation to each other.

Brief description of the drawings

[0015] In the following, the invention will be described in more detail by means of some examples and with reference to the appended drawings, in which

Fig. 1

shows a system of prior art, which comprises a mast structure and in which the presented apparatus can be applied,

Fig. 2

shows an example of an apparatus provided with a crane,

Fig. 3

shows a system comprising the apparatus and crane shown in Fig. 2,

Figs. 4 and 5

illustrate the operation of the system shown in Fig. 3, where the frame structure and the work platform move in relation to each other,

Fig. 6

shows another example of an apparatus provided with a work platform,

Fig. 7

shows a system comprising a work cage, and

Figs. 8a, 8b and 8c

show some rail structures.

Detailed description of the invention

[0016] Figure 1 shows a system of prior art comprising a mast structure 1, a work platform 2 which can be lifted and lowered and which comprises a frame structure 3 with a flooring. The railings 4 bordering the flooring also comprise gates 5 and steps 6 for climbing to the work platform when the work platform is in the lowered position. The work platform 2 is mounted to the mast structure 1 by means of a lifting and lowering device 7. The lifting and lowering device 7 comprises the necessary control devices for lifting and lowering the work platform 2 together with the lifting and lowering device 7 in such a way that the work platform 2 moves along the mast structure 1. In this example, the control devices comprise a drive pinion which functionally engages a toothing provided in the mast structure 1.

[0017] In the example of Fig. 1, the mast structure 1 is placed on top of a movable base 8. The base 8 constitutes a haulable carriage, and it comprises several adjustable supporting feet 9. The mast structure 1 can be extended by means of module structures to a desired height, and furthermore, it can be mounted to a building or other structures, if necessary, by applying fasteners to support and brace the mast structure 1. The system of Fig. 1 is also well described by the features which have already been presented earlier.

[0018] Figure 2 shows an example of a novel apparatus 10, in this case particularly for the lifting and transfer of loads, which apparatus can be connected e.g. to the mast structure 1 of Fig. 1 in such a way that it can move along the mast structure 1. Said apparatus makes the above-presented advantages possible. In combination with the work platform 2, the apparatus 10 constitutes a system with very versatile uses at various worksites.

[0019] In the example of Fig. 2, the apparatus 10 comprises a crane 11 whose principle of operation is based on a knuckle boom crane which also has a rotary movement around a vertical axis of rotation. The crane 11 comprises two boom parts which are movable in the vertical direction and are connected to each other by a joint. One boom part is connected by a joint to the frame 12 of the apparatus. In this example, the outermost boom part is telescopic, wherein its length is changeable. The telescopic structure or the joints of the boom parts are not necessary, but by means of them, the reach and the operating range of the crane 11 can be increased significantly, as well as by means of said rotary movement.

[0020] With respect to the structure of the crane 11, it is possible to apply components, actuators, control systems and control means which are known as such from the structures of cranes applied in, for example, vehicles or various working machines. In this example, the boom parts and the rotary movement of the crane 11 are controlled by means of cylinders and pressurized medium. The control system used for controlling the crane 11 applies, for example, control valves known as such, which are operated electrically or manually and which control the pressure in the cylinders and the flow of pressurized medium.

[0021] If necessary, the control system produces the volume flow and the pressure of the pressurized medium by means of a pump, or the pressurized medium required by the apparatus 10 is obtained from an external source. In some examples, the pressurized medium is produced by means of a pump at the apparatus 10, at the work platform 2 or even at the movable base 8, from where the pressurized medium is led by hoses or pipes via the control valves to cylinders or other actuators, such as motors. The control system comprises the necessary manual control means for the control of the crane 11, and they are normally placed within the reach of the operator, for example at the work platform 2. The control system can be primarily based, for example, in connection with the frame 12. The control system can also be operated by remote control, so that the necessary manual control means can also be placed in the remote control which can be carried with the work platform 2, or elsewhere.

[0022] The outermost boom part is provided with the necessary connecting means, to which e.g. a lifting hook or lifting ropes can be connected. In one example, there is only one boom part, and in other examples, there are more than two boom parts. In an example, the rotary movement of the crane 11 is not implemented. In an example, as shown in Fig. 7, a small work platform or work cage 25 is connected to the outermost boom part, wherein the crane 11 is intended for moving the work cage in such a way that a worker in the work cage has access close to the object. In the structures of said work cage and work platform, it is possible to apply solutions which comply with the prior art. In the example of Fig. 2, the frame 12 comprises a cylindrical vertical structure, to which the crane 11 or a corresponding lifting device is connected. According to the example of Fig. 6, it is also possible to apply various girder and lattice systems consisting of a single element or several separate elements in the frame 12. A lower support 13 is mounted to the lower part of the frame 12, by means of which support the frame 12 can be connected to the mast structure 1 in a movable manner. The lower support 13 comprises, for example, a square braced structure with supporting rollers which are placed against the mast structure and roll along the same. The supporting rollers are placed in the braced structure in such a way that they keep the lower part of the frame stationary in the horizontal direction with respect to the mast structure 1. In this example, the lower support 13 is implemented by means of eight supporting rollers which are placed substantially at the same height and are placed against the four sides of the mast structure 1. The braced structure can be dismounted or opened so that the crane 11 and the frame 12 can be installed in their place. In the example of Fig. 2, the braced structure is partly open, but it may also be closed.

[0023] An upper support 14 is mounted to the upper part of the frame 12, by means of which support the frame 12 can be connected to the mast structure 1 in a movable manner. In this example, the upper support 14 and its structure comply with the same principles as the lower support 13. Naturally, the structures of the supports 13, 14 may also differ from each other, but in view of the manufacture, it is simple that they match each other. Typically, the crane 11 is connected to the frame 12 substantially at the same height as the upper support 14, or it is slightly higher than that.

[0024] In the example of Fig. 2, the crane 11 is connected by a rotary pillar 15 to the upper part of the frame 12, as an extension to the frame 12, and an actuator 16 for rotating the crane 11, that is, a cylinder with a changeable length, is connected to the pillar 15 on one hand and to the upper support 14 on the other hand. An actuator 17 for lifting and lowering the first boom part, that is, a cylinder with a changeable length, is connected between the pillar 15 and said boom part.

[0025] The upper support 14 and the lower support 13 are placed at a suitable distance from each other in the vertical direction so that, for example, load forces caused by the weight of the crane 11 or by the manipulation of loads and weights and being effective on the supports 13, 14 and the mast structure 1 would be sufficiently low. The magnitude of the load forces is influenced particularly by the vertical distance between the upper support 14 and the lower support 13. The load in the crane 11 causes a moment of torque whose magnitude depends, among other things, on the horizontal distance between the load and the upper support 14. For example, the lower support 13 must compensate for the moment of torque in such a way that the lower support 13 is supported to the mast structure 1, simultaneously causing a horizontal load force. An increase in the distance between the lower support 13 and the upper support 14 will result in a decrease in the horizontal load force, respectively. At the same time, the load of the frame 12 is also decreased. Thanks to this, the structure of the frame 12 can be made lighter, and its elongation will not excessively increase the weight of the whole apparatus.

[0026] In one example, the distance between the upper and lower supports 13, 14 is also adapted in such a way that the apparatus can be connected to the mast structure 1 of Fig. 1 in such a way that the work platform 2 is placed between said supports. In an example, the supports 13, 14 are placed directly below and above the work platform 2 and the lifting and lowering device 7. In the examples of Figs. 2 and 3, the distance is so great that the work platform 2 in combination with the lifting and lowering device 7 is capable of moving independently in the vertical direction in the area between the supports even when said supports and the frame 12 together do not move. The upper support 14 is placed above the work platform 2, and the lower support 13 is placed below the work platform 2.

[0027] In the example of Fig. 2, as well as in the example of Fig. 6, the apparatus is not equipped with a separate lifting and lowering device, by means of which the apparatus would move along the mast structure 1. In this way, a structure is achieved which is as simple and reliable as possible. Pushed by the work platform 2, or preferably by the lifting and lowering device 7, the apparatus is moved upwards. The apparatus moves downwards with the platform 2, until the lower support 13 encounters the lower part of the mast structure 1 or another corresponding obstacle and stops in place, which situation is illustrated in Fig. 4. When allowed by the distance between the supports 13, 14, even after this the work platform 2 may move down to some extent, which situation is illustrated in Fig. 5. This is possible because the apparatus is structurally separate, for example, from the lifting and lowering device 7. Consequently, the work platform 2 can be driven down without being restricted by said apparatus, wherein climbing to the platform and unloading or loading are easy.

[0028] The apparatus, for example its upper support 14, can also be temporarily connected or locked to other structures, such as the lifting and lowering device 7. In spite of the locking, the structures and their operation may comply with the principles presented in this description. It is also possible to lock e.g. the upper support 14 or the lower support 13 or both of them by means of a brake, whereby in the situation of Fig. 2 the work platform 2 can be lowered down to some extent so that said apparatus remains stationary. The apparatus may thus, if necessary, comprise the necessary brake devices for keeping it in position.

[0029] Figure 3 illustrates the operation of the apparatus of Fig. 2 in the system of Fig. 1. The structure of the lifting and lowering device 7, which in this example extends some distance above the work platform 2, is supported to the upper support 14 and pushes it upwards. In the example of Fig. 2, the upper support 14 or any other structure of the apparatus is not connected by fastenings to the structure of the work platform 2 or the lifting and lowering device 7. The lifting and lowering device 7 carries the apparatus of Fig. 2. In the example of Fig. 3, a weight 17 has been transported with the work platform 2 to the upper part of the mast structure 1. The lower support 13 remains at a distance from the work platform 2 and its frame structure 3. The frame 12 connecting the supports 13, 14 passes the work platform and is also placed outside the work platform 2, adjacent to it, wherein it is not necessary to make changes in the work platform 2 because of the frame 12. As already noted earlier, the frame 12 can be a girder and lattice structure consisting of a single element or several separate elements. The work platform 2 and the frame 12 move along the mast structure 1 by means of the lifting and lowering device 7. The moments of torque effective on the frame 12 and the supports 13, 14 cannot affect the work platform 2 or the lifting and lowering device 7 which is only subjected to the vertical load force caused by the weight 17 and the total mass of the apparatus shown in Fig. 2.

[0030] According to the apparatus example shown in Fig. 6, the frame 12 that connects the supports 13, 14 passes the work platform and extends through the work platform 2. The work platform 2 is supplemented with a connecting part 18, by which the load forces of the work platform 2 can be transmitted to the frame 12 and further via it to the mast structure 1. In this way it is possible to provide work platforms which are longer than normal, and their protrusions, because the loads can also be distributed by means of the supports 13, 14. In this way, the loads are not transmitted to the mast structure merely by means of the lifting and lowering device 7. In this example, the frame 12 is a vertical beam structure placed next to the mast structure 1. The work platform 2 and the frame 12, which are also separate in this example, move along the mast structure 1 by means of the lifting and lowering device 7. The frame 12 is capable of moving in relation to the connecting part 18 which comprises, for example, supporting rollers rolling along the frame 12.

[0031] To achieve the above-presented advantages, the mast structure can in some examples also be replaced by a rail structure, to which the work platform is connected, for example by means of the lifting and lowering device, or to which the apparatus according to the example of Fig. 2 or 6 is connected. The lifting and lowering device 7 comprises the necessary actuators for lifting and lowering the work platform together with the lifting and lowering device in such a way that the work platform moves along the rail structure. According to an alternative, the lifting and lowering device is separate from the work platform and is arranged in connection with the rail structure, for example at its upper end. The lifting and lowering device is connected to the work platform by means of, for example, one or more coilable wire ropes. Figures 8a-8c show some examples of a rail structure 19 which is connected to a building. The rail structure 19 consists of, for example, one or more I-beams. A dash-and-dot line depicts the connection of the work platform or said apparatus to the rail structure.

[0032] The invention is not limited solely to the above-described examples and the alternative shown in the drawings, but it can also be applied in the scope defined by the appended claims.

Claims

1. A system comprising:

- a mast or rail structure (1, 24) which is substantially vertical;

- a movable work platform (2) which is connected to the mast or rail structure in such a way that the work platform is capable of moving up and down along the mast or rail structure;

- a lifting and lowering device (7), under whose control the work platform can be moved along the mast or rail structure;

characterized in that the system further comprises:

- a movable frame structure (12) which is connected to the mast or rail structure in such a way that the frame structure is capable of moving up and down along the mast or rail structure; and

- an upper support (14) and a lower support (13) which are positioned at a distance from each other in the vertical direction and by means of which the frame structure is connected to the mast or rail structure;

- wherein said frame structure extends past the work platform in such a way that the upper support is placed above the work platform and the lower support is placed below the work platform.

2. The system according to claim 1, characterized in that said distance is so great that the work platform can be moved between the upper support and the lower support also when the frame structure and said supports are immovable in place.

3. The system according to claim 1 or 2, characterized in that a first partial system which comprises at least the work platform (2) is structurally separated from a second partial system which comprises the frame structure (12) and said supports (13, 14), and the second partial system is supported to the first partial system in such a way that the second partial system moves up and down with the first partial system.

4. The system according to claim 3, characterized in that when the second partial system stops during its movement down, the first partial system is capable of releasing itself from the second partial system and continuing its movement down.

5. The system according to any of the claims 1 to 4, characterized in that the lifting and lowering device or the work platform carries the upper support during the movement up and down.

6. The system according to any of the claims 1 to 5, characterized in that the partial system formed by the frame structure and said supports is not equipped with a separate lifting and lowering device.

7. The system according to any of the claims 1 to 6, characterized in that the frame structure connects said supports and is placed structurally separately from the work platform, or alternatively, the frame structure connects said supports and the work platform is supported to the frame structure during the movement up and down.

8. The system according to any of the claims 1 to 7, characterized in that the system also comprises a crane (11) connected to the frame structure (12), for manipulating loads and weights.

9. An apparatus comprising:

- a movable frame structure (12) which is arranged to be connected to a substantially vertical mast or rail structure (1, 24) in such a way that the frame structure is capable of moving up and down along the mast or rail structure; and

- an upper support (14) and a lower support (13) which are positioned at a distance from each other in the vertical direction and by means of which the frame structure is arranged to be connected to the mast or rail structure;

- wherein said frame structure connects said supports which are positioned in the vertical direction at such a distance from each other that makes it possible to connect a movable work platform (2) to the mast or rail structure in such a way that said work platform is placed between said supports.

10. The apparatus according to claim 9, characterized in that said apparatus is not equipped with a lifting and lowering device, under whose control the apparatus could be moved along the mast or rail structure.

11. The apparatus according to any of the claims 9 to 10, characterized in that the apparatus also comprises a crane (11) for manipulating loads and weights, or a work platform (2) connected to the frame structure (12).

12. A crane device comprising:

- a movable frame structure (12) which is arranged to be connected to a substantially vertical mast or rail structure (1, 24) in such a way that the frame structure is capable of moving up and down along the mast or rail structure;

- a crane device (11) for manipulating loads and weights, connected to the frame structure; and

- an upper support (14) and a lower support (13) which are positioned at a distance from each other in the vertical direction and by means of which the frame structure is arranged to be connected to the mast or rail structure;

- wherein said frame structure connects said supports which are positioned in the vertical direction at such a distance from each other that makes it possible to connect a movable work platform (2) to the mast or rail structure in such a way that said work platform is placed between said supports.

13. The crane device according to claim 12, characterized in that the frame structure also passes said work platform and is placed structurally separately from the work platform, and that said distance is also such that the work platform is capable of moving up and down along the mast or rail structure and simultaneously moving in relation to said supports.

14. The crane device according to claim 12 or 13, characterized in that said crane device is not equipped with a lifting and lowering device, under whose control the crane device could be moved along the mast or rail structure.

Drawing