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[0001]     This application is a continuation application of International Patent Application No. PCTEP2002/007764 having an international filing date of Jul. 12, 2002, the entire disclosure of which is incorporated by reference herein. 
     
    
       [0002]     The present invention relates to a work stage or working gantry, for receiving and/or positioning a work platform.  
       BACKGROUND  
       [0003]     French patent specification FR 2 641 018 relates to an assembly device for elevator shafts. It is attached to the door threshold and has two parallel bars that rest against the opposite wall. In addition, a supporting ladder element is provided as the mode of access to a horizontal work platform. The bars are configured as telescopic rods with locking pins and they enclose an angle of 25° relative to the horizontal. This assembly device is very complex and configured with numerous parts. A rapid and simple assembly is not possible.  
         [0004]     Moreover, a work stage is known that has the following features (DE 199 28 574 C2). The work stage comprises a device for receiving and/or positioning a work platform. The device serves to position the work platform and is equipped with a holder or a support part on which the work platform is adjustably arranged and that serves as a bracing part. For this purpose, the holder has an arrangement by means of which the work platform can be supported on one side against a counter-support or against a wall. Moreover, on an opposing side, the work platform has a second arrangement that can likewise be supported against a counter-support or a wall by means of the support part. Facing the opposing side, the holder has a safety mechanism for the work platform that consists of a holding means and of a beam as a supporting device and that has a second support part that can be laid against the wall. The holding means is configured as a tie rod whose one end is connected to the work platform and whose other end is movably connected to the beam. In order for the work platform to be supported, it has to have at least two side walls that are opposite from each other and provided in a shaft section.  
         [0005]     German patent specification DE 803 075 C as well as world patent application WO 00/70169 A both describe a work stage with a vertical strut that is rigid with respect to the door opening, whereby a crossbeam for receiving a work platform is bearing-mounted so as to swivel on said vertical strut. The crossbeam is affixed on its side opposite to the vertical strut by means of a tie rod that is attached to the vertical strut above the crossbeam. The tie rod can be articulated so that the work platform can be folded open and closed.  
       SUMMARY OF THE INVENTION  
       [0006]     An object of the present invention is to provide a simply constructed work stage for shafts of elevators or for other shafts that can be installed in the area of the wall opening or door opening by a single person within a short period of time.  
         [0007]     The present invention provides a work stage including a device for receiving and/or positioning a work platform, the device for the work platform has a support part to which the work platform is attached by means of a first holder and which supports the entire device. The work platform can rest against a counter-support or a wall in the area of a first side by means of the first holder. The work platform is connected by means of the first holder to a vertical strut that is arranged essentially at a right angle to a crossbeam of the work platform. On a second side opposite from the first side, the work platform has a second holder by means of which the work platform can be held. The second holder is connected to a tie rod that is rigidly and/or movably connected with its one end to the work platform and with its other end to the vertical strut. On the work platform, parallel to and at a distance from the first vertical strut, at least one additional vertical strut can be installed that serves to receive one or more transverse struts.  
         [0008]     The vertical strut and the crossbeam of the work platform that are connected to the vertical strut by means of the tie rod are bearing-mounted by means of the first holder so as to pivot simultaneously around a shared bolt on the support part.  
         [0009]     Due to the advantageous configuration and arrangement of the work stage, it can also be placed against just one vertical wall that is provided with an opening and it can easily be clamped into this opening without there being a need for a wall element opposite from the wall opening or door opening for this purpose. The work stage is placed in a simple manner with its vertical strut into the wall opening, whereby the lower part rests on a floor or cover section of the floor while the upper part of the vertical strut pivots against the inside of the wall and comes to rest against this wall, from where the assembly is carried out.  
         [0010]     With an eye towards simple assembly, it is advantageous for the crossbeam and the vertical strut to be placed into the first holder and subsequently secured by means of a bolt.  
         [0011]     For this purpose, it is advantageous for the work platform to be formed by the crossbeam and by a baseplate that lies on the crossbeam, whereby the crossbeam is connected to the tie rod by means of the second holder.  
         [0012]     Regarding an adaptation to the shaft size, it is advantageous for the tie rod to be connected to the second holder by means of an articulated joint connection.  
         [0013]     It is also advantageous for the first vertical strut to be connected to the second vertical strut by means of three transverse struts that are arranged essentially horizontally.  
         [0014]     Regarding a flexible use, it is advantageous that, above the work platform, there is a second work platform with a baseplate that is connected to the first vertical strut and to the second vertical strut by means of a crossbeam.  
         [0015]     For this purpose, it is also advantageous for a vertical strut and a vertical rear strut to be associated with the second work platform, whereby the vertical strut is attached to the crossbeam and the rear strut is inserted into the vertical strut.  
         [0016]     It is especially advantageous for the vertical strut and the rear strut to be connected by means of three essentially horizontal transverse struts.  
         [0017]     For this purpose, it is advantageous for the work platform to have an opening as a passage and for a ladder.  
         [0018]     For this purpose, it is advantageous for the first vertical strut to receive or support the entire work platform.  
         [0019]     An additional possibility according to an embodiment is that the support part for supporting or receiving the work platform is configured as a mating element and/or as a form-fitting element.  
         [0020]     Furthermore, it is advantageous for the support part to be configured as a bracket that can rest against the corner part of a wall or of a door threshold. Through the use of a bracket, the vertical strut can easily rest on and be clamped onto the corner area of the floor, so that the floor bears the main load of the entire work platform, whereby the upper part of the vertical strut merely absorbs the tensile load of the work platform.  
         [0021]     It is also advantageous for the first holder to have a vertical receiving part to receive the vertical strut in a form-fitting manner and/or a second horizontal receiving part to receive the horizontal crossbeam to which the baseplate can be connected, and a U-shaped receiving part to receive the vertical and the horizontal receiving parts.  
         [0022]     Since horizontal receiving parts are used, side parts or grate fasteners or else additional struts that serve to receive the work platform can be readily mounted on the work platform so that the height can easily be changed within the device in this manner. In the embodiment, only the right-hand part of the work stage is shown. The work stage consists of two similar or identical receiving parts between which the work platform or the baseplate is suspended or attached. Laterally, the baseplate or the work stage is secured by lateral delimitations which are configured as transverse struts.  
         [0023]     According to a preferred embodiment of the solution according to the invention, it is finally provided that at least the horizontal receiving part and the vertical receiving part form a one-piece component.  
         [0024]     An especially significant aspect for the present invention is the fact that the U-shaped receiving part can be permanently connected to the support part configured as a bracket.  
         [0025]     In conjunction with the configuration and arrangement according to the invention, it is advantageous for the tie rod to be connected to the vertical strut by means of an upper holder in the area of the upper part of said vertical strut.  
         [0026]     It is also advantageous for the holders and/or the vertical struts to each have at least one connecting means that serves to receive horizontal or approximately horizontal or slanted additional transverse struts and/or baseplates.  
         [0027]     Moreover, it is advantageous that the connecting means are adjustably mounted on the vertical struts and can be attached to the vertical struts by means of safety elements or bolts.  
         [0028]     Moreover, it is advantageous for some of the receiving parts to be configured as a tube and some as a bracket, L-shaped part or U-shaped part.  
         [0029]     It is also advantageous that the receiving parts, which are connected to each other, can be connected to each other in an articulated manner.  
         [0030]     It is also advantageous for the work platform or the baseplate to be of such a width and/or length that it can be pivoted through the door opening. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0031]     Additional advantages and details of the invention are explained in the claims and in the description and depicted in the figures, which show:  
         [0032]      FIG. 1   a  a schematic depiction of a work stage that can be used in elevator shafts or placed in wall openings of buildings;  
         [0033]      FIG. 1   b  various positions of the pivotable work stage;  
         [0034]      FIG. 2  another embodiment of the work stage with a double frame, which is attached to the upper end of the work stage;  
         [0035]      FIGS. 3 and 4  various arrangements for connecting the struts of the work stage.  
     
    
     DETAILED DESCRIPTION  
       [0036]     In the drawing, the reference numeral  1  designates a device for receiving and/or for positioning a work platform which can be placed and attached either between two opposing walls  10 . 1 ,  10 . 2  of an elevator shaft or, in a simple manner, in the opening of a vertical wall  10 . 1 , in the area of a door threshold  7 . The device  1  for securing the work platform has a foot that is configured as a support part  4  and, in this embodiment, consists of a bracket. In an advantageous manner, the support part  4  or the bracket can be placed onto a corner edge at the bottom of a wall  10 . 1  or of a door threshold  7  and, in this way, it can hold the entire device  1  for receiving and/or positioning the work platform  2 . A first holder  12  is securely attached to the support part or to the bracket  4 .  
         [0037]     The first holder  12 , as shown in  FIG. 4 , consists of a horizontal receiving part  12 . 1  whose cross section is U-shaped. A horizontal receiving part  12 . 2  is placed into the U-shaped receiving part  12 . 1  of the holder  12 , and said receiving part is configured as a square or rectangular tube and can be connected to a vertical receiving part  12 . 3  or welded to the wall sections of the vertical receiving part  12 . 3  that is configured as a square or rectangular tube. A horizontal crossbeam  16  is inserted and likewise secured in the horizontal receiving part  12 . 2  of the first holder  12 . One or more bores  24  can be provided in the legs of the U-shaped receiving part  12 . 1  in order to receive a bolt  23  that extends through bores (not shown in the drawing) of the horizontal receiving part  12 . 2 , of the crossbeam  16  and of the vertical receiving part  12 . 3 . There can also be several bores arranged next to each other in the legs of the U-shaped receiving part  12 . 1  and/or in the crossbeam  16 , so that the crossbeam  16  can be moved horizontally in the receiving part  4  and adapted to the different conditions, for example, with respect to  FIGS. 1   a  and  1   b , to the shaft width between the walls  10 . 1 ,  10 . 2 .  
         [0038]     Laterally from the crossbeam  16 , the lower end of a vertically oriented strut or vertical strut  14  can be received in the vertical receiving part  12 . 3 . The vertical strut  14  can likewise be locked by the above-mentioned bolt  23 . The vertical strut  14  can be configured as a simple rectangular tube or as a telescopic tube, so that the length of the vertical strut  14  can be changed and adapted to the varying working conditions.  
         [0039]     The first holder  12 , as already mentioned, is connected to the bracket  4  either permanently or else detachably by means of screw elements (not shown here). The embodiment depicted in  FIG. 4  shows only the right-hand receiving part  12 . However, the work platform  2  requires at least two identical first holders  12  that are at a distance from each other in a direction that is at a right angle to the drawing plane, on each of which a crossbeam  16  is provided. A baseplate  15  is depicted in  FIGS. 1   a  and  1   b  which rests on the two crossbeams  16  that are arranged at a distance from each other and which can be attached to said crossbeams  16 . The first holder  12 , which is offset towards the back at a right angle to the drawing plane, and the appertaining crossbeam  16  are not shown. The baseplate  15  forms the work platform  2  on which the worker can move freely.  
         [0040]     The support part  4  is attached at a first side  6   a  of the work platform  2 . At a second side  6   b  of the work platform  2  opposite from the support part  4 , there is a second holder  9  which is depicted in greater detail in  FIGS. 3 and 4 . The second holder  9  serves to connect a tie rod  11 , which here is connected at one end to the second holder  9  rigidly or movably by means of a bolt or an articulated joint connection  20  respectively, while the other end of the tie rod  11  is connected to another vertical, upper holder  3 , likewise by means of a hinge bolt  21 . The upper holder  3  according to  FIGS. 2 and 4  is connected to the vertical strut  14  rigidly, but in such a way that its height is adjustable.  
         [0041]     The second holder  9 , as shown in  FIGS. 3 and 4 , consists of a vertical receiving part  26  and of a horizontal receiving part  17  that can likewise be configured as rectangular tubes. A vertical strut  33  is held in the receiving part  26  and the horizontal crossbeam  16  is held in the receiving part  17 . The crossbeam  16  and the vertical struts  33  are illustrated in greater detail in  FIGS. 1   a  and  2  and can be secured by means of the bolts  23  shown in  FIG. 4 .  
         [0042]     The receiving part  26  is followed by a slanted receiving part  18  whose cross section consists of a U-shaped section into which the lower end of the tie rod or of the slanted strut  11  is inserted and secured by means of the safety bolt  20 . There can be several bores arranged next to each other in the receiving part  19  and/or in the tie rod  11  so that the safety bolt  20  can be inserted in various positions, thus changing the connection site of the tie rod  11 . The other or upper end of the tie rod  11  is likewise arranged in a slanted receiving part  18 . 1  and locked by means of the safety bolt  21 . The two receiving parts  18  and  18 . 1 , which enclose an angle of 45° relative to the vertical or horizontal, can also be connected to the horizontal receiving part  17  and to the vertical receiving part  26  in such a way that the angular position of the receiving part  18 . 1  or  18  can change with respect to the horizontal.  
         [0043]     The two holders  9  and  12  are located on both sides of the work stage  2 , which is rectangular in shape in the embodiment according to  FIGS. 1   a ,  1   b  and  2 . In the embodiment, there are two vertical struts  14 ,  33  to which the tie rod  11  is attached. The vertical struts  14 ,  33  are arranged at a distance from each other, whereby the vertical strut  33  is provided in the area of the second side  6   b  on the baseplate  15 . The horizontal crossbeam  16  for receiving the baseplate  15  and the transverse struts  29 ,  30  and  31  or, according to  FIG. 2 , the transverse struts  34 . 2 ,  35  and  36  and the crossbeam  34  for receiving another baseplate  39 , are located between the vertical struts  14  and  33 . According to  FIG. 1   a , the ends of the transverse struts  29  to  31  or  34 . 2  to  36  are each held in connecting means  13 . 1 ,  13 . 2 . The connecting means  13 . 1 ,  13 . 2 , as shown by way of the example of the connecting means  13 . 3  according to  FIG. 4 , are attached to the various holders  12  and  9  or, according to  FIG. 2 , directly to the vertical struts  14  and  33 .  
         [0044]     The connecting means can likewise each be placed with one holder onto the vertical struts  14 ,  33 . The connecting means  13 . 1 ,  13 . 2 , as already mentioned and shown in  FIG. 1   a , serve to receive the horizontal transverse struts  30 ,  31 . According to  FIG. 2 , the transverse strut  34 . 2  is connected to the connecting means  13 . 4 , which is directly attached to the holder  5 . The transverse struts  29  to  31  and  34 . 2  to  36 , including the connecting means  13 . 1  to  13 . 4  and the crossbeams  16 ,  34 , can be locked with the bolts (not shown in the drawing), whereby the transverse strut  36  can be configured as a handrail.  
         [0045]     The transverse struts  29  to  31  and  34 . 2  to  36  serve to laterally delimit the work platforms  2 ,  2 ′ and also to safeguard the worker on the work platforms  2 ,  2 ′. Moreover, however, the crossbeams  16 ,  34  can also to serve to receive baseplates  15  that, depending on the working conditions, can be mounted at different heights so as to accordingly follow the work progress upwards and to provide the operator with one or more work platforms  2 ,  2 ′ at various levels.  
         [0046]     In the embodiment, according to  FIG. 2 , another vertical strut  14 . 2  and a rear strut  37  are provided, whereby the lower end of the vertical strut  14 . 2  can be connected to the transverse strut  34  permanently and/or detachably by means of a connecting means. The vertical strut  14 . 2  likewise has connecting means on which the transverse struts  35 ,  34 . 2  and  36  are placed. This results in two different work platforms  2 ,  2 ′ at different heights. The upper work platform  2 ′ or the baseplate  39  can be accessed via a ladder  38  that stands upright in the area of the lower work platform  2 .  
         [0047]     In an advantageous manner, the vertical strut  14  and/or a vertical strut  14 . 2  are configured in such a way that they can bear the entire weight of one or more work platforms with all of the appertaining individual parts. For this purpose, the vertical strut  14 , as already mentioned, rests with its lower end against the wall section  10 . 1  and with its upper contact part  14 . 1  against the inside  40  of a door lintel  19 . 1  of a door opening  19 . The door lintel  19 . 1  absorbs the entire tilting moment of a work platform  2 . The other parts of the work platform  2  are secured only by the two tie rods  11  situated next to each other. Additional support elements are not necessary.  
         [0048]     The crossbeams  16  and the transverse struts  29  to  31  and  34  to  36  can likewise be configured with a variable length. Therefore, for example, the working area of the work platform  2  can be enlarged or the work platform  2  can be adapted to the depth of the shaft (not shown in the drawing).

Summary:
A work stage includes a work platform having first and second sides and a cross-beam, a first support part supporting the work platform and a counter-support disposed at the first side. In addition, the work stage includes a first holder including a bolt and attaching the work platform to the first support part and enabling the work platform to rest against the counter-support. A first vertical strut is disposed essentially at a right angle to the cross-beam, a second holder is disposed on the second side and configured to hold the work platform, a tie rod is connected at one end to the second holder and at the other end to the vertical strut, and a second vertical strut is disposed parallel to and at a distance from the first vertical strut and configured to receive at least one transverse strut. The first vertical strut and the crossbeam are bearing mounted at the first holder so as to pivot simultaneously around the bolt.