Patent Publication Number: US-6712337-B1

Title: Hoist system

Description:
This application is the U.S. national phase of international application PCT/SE00/002146 filed Nov. 1, 2000, which designated the U.S. 
    
    
     The present invention relates to a hoist system, comprising at least one mast, a hoist trolley moveable externally along the mast, and a platform, which is articulately coupled to the hoist trolley so that it is horizontally pivoting about a substantially vertical axis between two end positions relative to the hoist trolley. The vertical axis is situated between the hoist trolley and the platform, as seen horizontally. 
     When renovating or constructing buildings, a hoist system of this kind provides transport of personnel and materials to and from the various landings of the building. The hoist system may also be utilised for work on the facade of the building by allowing building workers to stand on the platform when working. To make the entire facade of the building accessible from the platforms often a great number of masts with intermediate mediate platforms has to be placed in a row along the facade of the building, since for strength and security reasons each platform has a limited length. The hoist system may also be utilised in permanent installations for the maintenance of larger machines. 
     One type of platform typically used for work on building facades comprises smaller sections which can be interconnected to form an assembled rectangular platform with a suitable length. The assembled platform is coupled with its two short ends to two hoist trolleys running along two adjacent masts between which the platform extends. 
     In a known hoist system several masts can be arranged in a straight row along a straight building facade with platforms coupled between hoist trolleys of adjacent masts. This results in the advantage that the number of masts required along the building facade are minimised, since each mast, except the first and last mast in said row of masts, is utilised for carrying two platforms at mutual sides of the mast. In the known hoist system it is also possible to form a right-angled mast arrangement, in which the last mast in a straight mast row constitute the first mast in another mast row running perpendicular from the first mentioned mast row, i.e. said first and last mast constitute a mast common to both mast rows. Thus, the mast rows form one single continuous row of masts interconnected by the platforms. 
     In the known hoist system described above the common mast may have only one hoist trolley, which is coupled to a platform extending along the first mentioned mast row and to another platform extending along the last mentioned mast row. Alternatively the common mast may have two hoist trolleys, one of which is coupled to the platform which extends along the first mentioned mast row and the other hoist trolley of which is coupled to a platform extending along the last mentioned mast row. The described right-angled mast arrangement is suited for such ordinary facade sections which extend perpendicularly to each other and end in a corner. The common mast of course is placed at such a corner. 
     However, there are buildings with facade sections that form non-right-angled corners between adjacent facade sections, usually obtuse-angled corners, i.e. having angles between 90 and 180°. In contrast to the case described above with only one mast at each right-angled corner, in a building of this kind two masts, one in each mast row, must be placed closed to each other at the non-right-angled corner to be coupled to two adjacent platforms extending along respective facade sections. 
     The reason for this is that known hoist systems currently available on the market do not admit that one platform is carried by two adjacent masts which are turned relative to each other with an angle corresponding to the obtuse angle between adjacent facade sections. If the building has many such non-right-angled corners the costs for installation of twin masts at the corners may be significant, in particular when considering that each mast has to be equipped with a hoist trolley and a drive unit for driving the latter along the mast. 
     An object of the present invention is to provide a hoist system that allows installation of one single mast at a non-right-angled corner of for instance a building or a larger machine and installation of platforms extending from one or two hoist trolleys on the mast substantially in parallel with the facade sections forming the non-right-angled corner. 
     Another object of the invention is to provide a versatile hoist system allowing installation of a continuous row of masts and platforms along a facade including facade sections forming non-right-angled as well as right-angled corners. 
     These objects are achieved by means of a hoist system of the kind stated initially, which is characterised in that the position of the vertical axis is adjustable for adjusting the distance between the hoist trolley and the platform. Hereby the mast may be placed at a non-right-angled corner of a building and be anchored in a traditional manner at one of the two facade sections extending from the non-right-angled corner, and the platform can be angled horizontally relative to the hoist trolley so that it extends substantially in parallel with the second facade section. 
     Advantageously, the platform is pivoting 180° between the end positions, in such a manner that when the platform is at any of the end positions it can extend in parallel with a facade section extending from a right-angled corner of a building or a larger machine. In other words the platform may extend in a traditional manner out from the hoist trolley when it is adjusted in a central position, half way between the end positions, for enabling installation at a right-angled corner as well. 
     Furthermore, the advantage is achieved that the distance between the hoist trolley and the platform can be minimised when the platform is in said central position, which facilitates for a building worker on the platform to work on a building facade close to a mast. When the platform is to be turned from the central position to a position between the central position and any of the end positions, in accordance with the invention the position of the vertical axis first is adjusted so that the distance between the hoist trolley and the platform is increased. The required increase in distance depends on how broad the platform is. 
     The vertical axis is preferably adjustable at different distances from the hoist trolley and/or at different distances from the platform, as seen horizontally. 
     According to a preferred embodiment of the invention, the hoist system comprises a first coupling element coupled to the hoist trolley, and a second coupling element coupled to the platform, the second coupling element being articulately coupled to the first coupling element so that it is pivoting about said vertical axis. 
     To enable coupling of the platform to another hoist trolley on an adjacent mast by means of a further coupling element of the same kind as said first and second coupling elements, the platform is suitably articulately coupled to the second coupling element so that the platform is pivoting about a substantially horizontal axis. Since the hoist trolleys on two adjacent masts normally cannot be moved exactly synchronously with each other along the masts, the horizontal axis between the platform and the second coupling element at the respective masts allows that the platform can be tilted somewhat relative to the horizontal plane during hoisting or lowering, so that damaging stresses in the hoist system are avoided. 
     Preferably the first coupling element is articulately coupled to the hoist trolley so that it is pivoting about a further substantially horizontal axis, which further reduces the risk of damaging stresses arising in the hoist system, when a platform is moved along two adjacent masts. 
     The first coupling element may have at least two vertical bores situated at different distances from the hoist trolley, while the second coupling element may have at least one vertical bore spaced from the platform. Furthermore, an axle pin may releasably extend from any of the bores of the first coupling element and through the bore of the second coupling element, whereby the axle pin is coaxial with said vertical axis. Suitably, the bores of the first coupling element form a row of bores extending centrally out of the hoist trolley. 
    
    
     The invention is explained in more detail in the following with reference to the accompanying drawings in which 
     FIG. 1 is a side view of a hoist trolley in the hoist system according to the invention, 
     FIG. 2 is a view from above of the hoist trolley in FIG. 1 coupled to a platform by a coupling element of the hoist trolley and another coupling element of the platform, the platform being adjusted in an end position, so that it extends perpendicular to the front side of the hoist trolley, 
     FIG. 3 shows a perspective view askew from above of the coupling elements of the hoist trolley and platform adjusted in a second end position opposite the end position illustrated in FIG. 2, 
     FIG. 4 shows a perspective view askew from above of the coupling elements of the hoist trolley and platform adjusted in a central position, and 
     FIG. 5 shows a perspective view askew from above of the coupling elements of the hoist trolley and platform adjusted in a position situated between the positions of the coupling elements shown in FIGS.  2  and  4 . 
    
    
     In FIGS. 1 and 2 there is shown a hoist system according to the invention comprising a mast  2 , and a hoist trolley  4 , which by guide rollers  6  is moveable along vertical tubes  8  on the mast  2 . The hoist trolley  4  is provided with a motor  10 , which by a pinion  12  is in mesh with a rack  14  on the mast  2 . A coupling element  16  is articulately coupled to the hoist trolley  4 , so that it is pivoting about a horizontal axis  18 , and extends out of the hoist trolley  4  and mast  2 . A further coupling element  20  is articulately coupled to the coupling element  16 , so that it is pivoting about a substantially vertical axis  22 . A generally rectangular platform  24  is articulately coupled to the coupling element  20 , so that it is pivoting about a substantially horizontal axis  26  at a short end of the platform  24 . 
     The coupling element  16  and  20 , respectively, is designed as a framework with a generally triangular shape as seen from above. The coupling element  16  comprises an upper horizontal crossbeam  28 , which at its ends is journalled on the hoist trolley  4  to make the coupling elements  16  pivoting about the horizontal axis  18 , and a lower crossbeam  30 , which extends in parallel with the upper crossbeam  28  and which by fixing members  32  is yieldingly fixed to the hoist trolley  4 . Thus, the fixing members  32  allow a certain limited pivoting of the coupling element  16  about the horizontal axis  18  from a normal position, in which the coupling element  16  is directed horizontally out of the hoist trolley  4  and mast  2 . An upper centre beam  34  and a lower centre beam  36  extend in parallel with each other perpendicular out of the upper crossbeam  28  and the lower crossbeam  30 , respectively. The centre beams  34 ,  36  are provided with bores  38 , here five bores  38  in each centre beams  34  and  36 , respectively, each bore  38  in the upper centre beam  34  being situated vertically aligned with a corresponding bore  38  in the lower centre beam  36 . 
     The coupling element  20  comprises a horizontal crossbeam  40 , which at its ends is journalled on the platform  24  at the short end thereof to make the platform  24  pivoting about the horizontal axis  26 . An upper centre beam  42  extends perpendicular out of the crossbeam  40  to a free end. A lower centre beam  44  is attached to the upper centre beam  42  and extends in parallel with and under the latter to a free end situated under the crossbeam  40 . The lower centre beam  44  is provided with fixing members  46  at its free end for fixing the platform  24  to a coupling element  20  in case the platform  24  only is to be carried by one single hoist trolley  4 . 
     Also the centre beams  42  and  44  are provided with bores  48 , here two bores in each centre beam  42  and  44 , respectively, each bore  48  in the upper centre beam  42  being situated vertically aligned with a corresponding bore  48  in the lower centre beam  44 . The centre beams  42  and  44  of the coupling element  20  of the platform  24  are located at somewhat shorter distance from each other than the centre beams  34  and  36  of the coupling element  16  of the hoist trolley  4 , whereby the centre beams  42  and  44  are insertable between the centre beams  34  an  36 . An axle pin  50  is insertable through any of the two pairs of bores  48  in the centre beams  42 ,  44  and any of the five pairs of bores  38  in the centre beams  34 ,  36 , whereby said vertical axis  22  is formed coaxial with the axle pin  50 . The axle pin  50  and the five pairs of bores  38  thus allow that the axis  22  may be arranged at five different distances from the hoist trolley  4 . In the corresponding manner the axle pin  50  and the two pairs of bores  48  allow that the axis  22  is arranged at two different distances from the platform  24 . 
     FIG. 3 illustrates how the axle pin So is inserted into the outermost pair of bores  38  on the centre beams  34 ,  36  and the outermost pair of bores  48  in the centre beams  42 ,  44 , which allows pivoting of the platform  24  to an end position in which the platform  24  extends in parallel with the front side of the hoist trolley  4 , i.e. opposite the side of the hoist trolley  4  facing the mast  2 . The arrangement illustrated in FIG. 3 fits a straight-angled building corner. 
     FIG. 4 illustrates how the axle pin So is inserted into the innermost but one pair of bores  38  on the centre beams  34 ,  36  and the outermost but one pair of bores  48  in the centre beams  42 ,  44 , which reduces the distance between the hoist trolley  4  and the platform  24  when the platform  24  is in the centre position shown in FIG. 4 in which the platform  24  extends perpendicular to the front side of the hoist trolley  4 . The arrangement illustrated in FIG. 4 is suitable to install at a straight facade section that lacks corners. 
     FIG. 5 illustrates how the axle pin  50  is inserted in the central pair of bores  38  on the centre beams  34 ,  36  and in the innermost pair of bores  48  in the centre beams  42 ,  44 , and how the platform is pivoted to a position in which it extends about 45° to the front side of the hoist trolley  4 . The arrangement illustrated in FIG. 5 fits a building corner formed by facade sections that form an angle of 135° to each other. 
     For the sake of clarity certain details in the coupling element  16  are shown transparent in FIGS. 3-5. In reality these details are formed of plate material. 
     Of course, the platform  24  may be adjusted in any position relative to the hoist trolley  4  between the two end positions. With the aid of the bores  38  and  48 , the distance between the hoist trolley  4  and the platform  24  can be made as small as possible for every adjusted position.