Abstract:
A device that is usable to change the direction of a transport assembly, on which feed roller may be transported, includes a lower section and an upper section. The upper section is pivotally mounted on the lower section. The transport assembly is arranged on the side or on the top of the upper section and the upper section can be pivoted by an angular amount, relative to the lower section, by use of a drive unit. A drive motor of the drive unit has its output transmitted to the upper section by a drive belt. A positive drive exists between the motor and belt and a friction drive exists between the belt and the upper section.

Description:
FIELD OF THE INVENTION 
   The present invention is directed to devices for changing the direction of conveying or transport devices. The device includes an upper element and a lower element. The two elements are connected and are relatively movable. 
   BACKGROUND OF THE INVENTION 
   Turntables are known from DE 39 10 444 C2. These turntables can be rotated by 180° for coordinating the roll-off or discharge direction of horizontally stored supply rolls. 
   Rotatable turntables are also known from WO 98/12133 A1. These turntables have guides crossing each other and are provided with sets of track for receiving supply roll conveying carts. These turntables are rotatable over at least 90° and up to preferably 360°, so that the supply roll conveying carts can be shifted between crossing sets of track. 
   DE 41 19 407 A1 discloses turntables which are driven by the use of a belt via an interspersed friction clutch. 
   DE 40 06 486 A1 shows a turntable for moving gears, which turntable is driven by a drive motor, that is positively connected to the turntable by a toothed belt. 
   DE 43 45 090 A1 describes a turntable which is frictionally driven by the use of a cable. 
   DE 197 08 389 A1 describes a rail switch for a rail-operated floor conveying system. A pivotable support for a rail is frictionally connected with a belt. 
   A device for direction changing of rail-guided conveying carts is known from U.S. Pat. No. 1,800,722. A pivotable element can be uncoupled from a drive mechanism by the use of a coupling device. 
   SUMMARY OF THE INVENTION 
   The object of the present invention is directed to providing devices for changing the direction of conveying devices. 
   In accordance with the present invention, the object is achieved by the use of a direction changing device which includes an upper element, that receives the material being conveyed, and a lower element. The upper element is supported by the lower element and can be swiveled with respect to it by a drive assembly. The drive assembly is connected to the upper element by a drive belt. A frictional connection exists between one of the drive assembly and the belt or the belt and the upper element. 
   The advantages which can be achieved by the present invention reside, in particular, in that an effective overload protection is achieved by the frictional force transfer from drive belt or belts to the horizontally swivelable upper element of the device. Since drive forces can be transferred only by friction between the drive belt and the upper element and only up to a defined maximum value, this maximum value will not be exceeded. This means that if forces greater than this defined maximum value act between the drive belt and the upper element, the upper element will slip with respect to the drive belt. Any damage to other components, for example to the motor or to certain gear elements, is thus impossible. An adjustable tensioning roller, which can be brought into contact with the drive belt in various positions, can be employed for setting the forces which can be maximally transferred between the drive belt and the upper element. The tension of the drive belt can be changed by changing the position of the tensioning roller. Correspondingly higher or lower values of the forces transferred by the frictional connection result from changing of the tension of the drive belt by use of the adjustable tensioning roller. 
   A further advantage of the present invention rests, in particular, in that the force transfer between the drive mechanism and the upper element can be selectively interrupted by the inclusion of a coupling device. The drive mechanism and the upper element are kinematically coupled with each other in a first operational state of the coupling device, so that every positional change of the drive mechanism causes a positional change of the upper element, and each positional change of the upper element causes a positional change of the drive mechanism. In a second operational state of the coupling device, the upper element and the drive mechanism are kinematically decoupled from each other, so that the drive mechanism and the upper element can be moved independently of each other. By use of this coupling, it is made possible, in particular when the drive mechanism fails, to decouple the upper element from the drive mechanism by activating the coupling device, so that the upper element can be manually horizontally swiveled by the operator. 
   So that a decoupling of the drive mechanism from the upper element can be performed as quickly as possible in connection with devices arranged under the floor, it is preferable to be able to operate the coupling device from the top of the device. 
   So that the coupling device can be manually decoupled, in particular in case of an electrical failure, it should preferably also be at least manually operable. 
   An adjustable tensioning roller, in particular, can be employed as a coupling device, which adjustable tensioning roller can be brought into contact with the drive belt in at least two positions. In the first position, the tensioning roller tensions the drive belt at least sufficiently strongly so that a driving force can be frictionally transferred from the drive belt to the upper element. In the second position of the tensioning roller, the belt is relaxed at least sufficiently for the upper element to be rotated with respect to the lower element substantially without having to overcome frictional forces acting between the drive belt and the upper element. The drive mechanism can be coupled in or out by displacing the tensioning roller between its first and second positions. 

   
     BRIEF DESCRIPTION OF THE INVENTION 
     A preferred embodiment of the present invention is represented in the drawings and will be described in greater detail in what follows. 
     Shown are in: 
       FIG. 1 , a schematic top plan view of a device for changing the direction of a transport device in accordance with the present invention, 
       FIG. 2 , a belt drive portion of the device shown in  FIG. 1 , also in a top plan view, and in 
       FIG. 3 , the belt drive shown in  FIG. 2  in a cross-sectional view along the section line III—III of FIG.  2 . 
   

   DESCRIPTION OF THE PREFERRED EMBODIMENT 
   Referring initially to  FIG. 1 , there may be seen a device  01  for changing the direction of travel of a conveying device or of a transport device, for example the travel direction of rail-guided conveying carts  02 , on which horizontally placed supply rolls of paper or the like can be placed and thus conveyed. The direction changing device  01  is arranged in a recess  32  of a base body  31 , as shown in  FIGS. 1 and 3 , in a crossing area between first and second crossing sets of tracks  03  and  04 . The conveying carts  02 , on each of which a horizontally placed supply roll can be conveyed, can be displaced in the longitudinal direction on the sets of tracks  03  and  04 , as indicated by the directional arrow  06  in FIG.  1 . 
   A rotatably supported upper element  07  of the direction changing device  01 , on which a section of track  08  for receiving the conveying carts  02  is provided, can be horizontally swiveled, in the direction shown by the directional arrow  09 , until the track section  08  is aligned with either of the sets of tracks  03  or  04 . Then the conveying cart  02  is displaced until is completely arranged on the upper element  07  of the direction changing device  01 . Thereafter, the upper element  07  can be swiveled by 90° or, if required for aligning the supply rolls in a different defined longitudinal direction, by 180° or 270°. By this positional change, the track section  08  is aligned with a selected one of the sets of tracks  03  or  04 , and can be further conveyed in the direction of the set of tracks  03  or  04 . 
   A drive motor  12 , as shown in  FIG. 1 , can be employed for driving the upper element  07 , which upper element  07  is seated, rotatable around a central axis  11 , on a lower element, which is not specifically represented in  FIG. 1 , which lower element is fixedly connected with the base body  31 . A gear  13  and a driving pinion gear  14  are provided on the power take-off side of the drive motor  12 , which drive motor  12  may be, for example an electric motor  12 . A driving disk  16  is fastened on the underside of the upper element  07  and is opposite the driving pinion gear  14 , as seen in  FIG. 2. A  belt  17 , for example a toothed belt  17 , is brought into positive engagement with the driving pinion gear  14  for transferring the torque provided by the drive motor  12  on the power take-off side. The belt  17  itself is carried on a smooth-faced circumferential surface  22  of the driving disk  16  and transfers the drive output from the driving pinion gear  14  to the driving disk  16  in a non-positive way by the frictional forces acting between the circumferential surface  22  of the driving disk  16  and the belt  17 . 
   For setting the tension of the belt  17 , with which tension the belt  17  is stretched over the driving pinion gear  14  and over the circumferential surface  22  of the driving disk  16 , it is possible to push a pivotably seated tensioning roller assembly, generally at  18 , against the belt  17 . Pivotable tensioning roller assembly  18  is depicted generally in FIG.  1 . 
   The main components of the belt drive of the direction changing device  01  can be seen in the top a view shown in FIG.  2 . The inner surface of the drive belt  17  comes into positive contact with the circumferential surface  22  of the driving pinion gear  14 , so that it is possible by the provision of a rotatory drive of the driving pinion gear  14 , in accordance with the directional arrow  19 , to cause a forwardly or rearwardly directed control movement of the belt  17 , which belt movement direction is indicated by the directional arrow  21 . The inner surface of the belt  17  itself rests against the smooth-faced outer circumferential surface  22  of the driving disk  16 . The driving disk  16  is thus frictionally driven by its contact with the inside of the belt  17 , so that, as a result, a swiveling or rotational movement of the driving disk  16  and of the upper element  07 , which is arranged above the driving disk  16 , in accordance with a directional arrow  23 , again as seen in  FIG. 2 , can be provided. The drive arrangement  12 ,  13 ,  14  can alternatively be frictionally connected and the driving disk  16  can be positively connected with the belt  17 . 
   The belt  17  is deflected by a deflection roller  24  and by a tensioning roller  26 , which rollers  24  and  26  are situated between the driving pinion gear  14  and the driving disk  16 , as shown most clearly in FIG.  2 . The tensioning roller  26  is rotatably supported on a first or outboard end  37  of a pivot arm  27 . The pivot arm  27  can be pivoted at its second or inner end  38  around a pivot shaft  29  in accordance with a directional arrow  28 . Depending on the engagement position of the pivot arm  27 , the tensioning roller  26 , which is part of the tensioning roller assembly  18 , is pressed against the belt  17  with a higher or lower pressure, so that the tension of the belt  17  can be changed by use of this tensioning roller. 
   The frictional forces which can be transferred from the belt  17  to the driving disk  16  are directly correlated with the tension of the belt  17 , which belt tension can be affected by the tensioning roller  26 . It follows from this that, with an appropriate relaxation of the belt  17 , by swiveling the tensioning roller  26  outward, the drive output which can be maximally transferred between the belt  17  and the driving disk  16  can be changed. As soon as the belt  17  is relaxed to the extent that it essentially rests without contact pressure on the smooth, outer circumferential surface  22  of the driving disk  16 , no drive output can be transferred from the driving pinion gear  14  to the driving disk  16 . 
   As a result, it is therefore possible to use the tensioning roller  26  in the manner of a coupling device by pivoting the pivot arm  27 . By using the tensioning roller  26  to exert an appropriate tension on the belt  17 , the belt  17  will now be forced against the circumferential outer surface  22  of the driving disk  16  with such a high contact pressure that the upper element  07  can only be swiveled while the driving pinion gear  14  is simultaneously rotating. If the tensioning roller  26  is displaced by pivoting the pivot arm  27 , so that the belt  17  is essentially no longer under tension, the driving disk  16  can slide with respect to the belt  17  essentially without resistance, so that, for example, the upper element  07  can be manually swiveled without the driving pinion gear  14  or the drive belt  17  having to rotate together with the upper element  07 . 
   The mechanism which is operable for the adjustment of the tension roller  26  is represented in FIG.  3 . So that the direction changing device  01  can be arranged under the floor, a recess  32 , for example a bed, which is only partially shown in  FIG. 3 , is provided in the base body  31 . The direction changing device  01  can be arranged in recess  32  in such a way that the top of the upper element  07  essentially extends in the horizontal plane  33  that is defined by the top of the base body  31 . In the preferred embodiment of the present invention, the drive mechanism of the direction changing device  01 , which essentially consists of the drive motor  12 , the gear  13  and the driving pinion gear  17 , is also arranged in the recess  32 , wherein the drive motor  12  is fastened to the bottom  34  of the recess  32 . The bottom  34  of the recess  32  forms the lower, fixed element of the device  01  for changing a direction of travel of a conveying device. 
   The tensioning roller  26  is rotatably seated, by the use of a rolling bearing  35  on a bolt  36 . The bolt  36  itself has been screwed into the pivot arm  27  on the first or outboard end  37  of the pivot arm  27 . The second or inner end  38  of the pivot arm  27  has a cutout or aperture, in which a sleeve  39 , for example embodied as an elongated tube, can be fastened. A shaft  41  extends along the length of the interior of the sleeve  39 . A lower end  42  of the shaft  41  has been glued, by the use of an adhesive, into a cutout of the base body  31  and is used as an anchoring element. A tensioning element  44  which, in the preferred embodiment, is provided in the manner of a tensioning screw  44 , can be actuated by screwing the tensioning screw  44  in. Starting at a defined screw insertion depth, the tensioning element  44  engages indirectly through an intermediate washer  46 , the upper end  47  of the elongated sleeve  39 . By further screwing in of the tensioning element  44 , the distance between the bottom  34  of the recess  32  and the underside of the washer  46  is further shortened, so that, as a result, the elongated sleeve  39  can be clamped between the washer  46  and the base body  31  by screwing in the tensioning element  44 . So that the tensioning force exerted through the increasing screwing in of the tensioning element  44  rises as continuously and as linearly as possible, and not suddenly, an elastic element  48 , for example a rubber washer  48 , is positioned between the lower end  45  of the sleeve  39  and the bottom  34  of the recess  32 , which rubber washer  48  is elastically compressed when the sleeve  39  is clamped down by screwing in of the tensioning element or screw or bolt  44 . 
   To change the tension imparted to the belt  17  by the tensioning roller  26 , the tensioning element  44  is released or screwed out sufficiently far, so that the elongated sleeve  39  can be turned on the shaft  41 . Because of this, the position of the tensioning roller  26  relative to the belt  17  changes, so that a desired belt tension can be set. For actuating the coupling device, which is substantially constituted by the tensioning roller  26 , the pivot arm  27 , the sleeve  39  and the shaft  41 , simply and essentially without having to disassemble other components, a cutout  49  is provided above the tensioning element  44  in a cover plate  51 , by use of which cover plate  51  the recess  32  can be covered. A tool, for example a socket wrench, can be passed through the cutout  49  and the tensioning element  44  can be actuated in this manner. 
   For setting the tension of the belt  17  it is advantageous that the tensioning element  44  does not need to be completely released for resetting the pivot arm  27 . Otherwise it would be necessary, during the adjustment of the pivot arm  27 , to simultaneously hold the sleeve  39  in place and to tighten the tensioning element  44 . For this reason, surfaces  53 , on which tools can act, are provided at the upper end  47  of the elongated sleeve  39 , for example in the shape of a hexagon  53 , with which hexagonal surfaces  53  a tool for rotating the sleeve  39  can be brought into engagement. In that case, to adjust the pivot arm  27 , the tensioning element  44  is only sufficiently loosened or screwed out so that the sleeve  39  can be rotated with the aid of a tool, for example a tool in the form of a hexagon sprocket. Following the adjustment of the pivot arm  27 , the tensioning element  44  is again sufficiently tightened so that the sleeve  39  is clamped with a sufficient holding force. Thereafter, the cutout  49  in the cover plate  51  can be closed by the use of an appropriately shaped cover element  52 . 
   As a result, the coupling device constituted by the tensioning roller  26 , the pivot arm  27 , the elongated sleeve  39  and the shaft  41  can therefore be manually actuated by loosening, or screwing in of the tensioning element  44  and by subsequent rotation of the sleeve  39 . It is thus assured that the drive mechanism, constituted by the drive motor  12 , the gear  13  and the driving pinion gear  14 , can be decoupled at any time, in particular in case of a possible failure of the drive mechanism, from the upper element  07  of the device  01 , so that the upper element  07  can be manually swiveled by the operators. 
   Since the sleeve  39  and the shaft  41  extend upward to a location close to the underside of the cover plate  51 , it is possible to operate the coupling device without having to disassemble other components, except for the removal of the cover plate  52 . 
   The conveying cart  02  is primarily configured as a rail-guided conveying cart  02  for receiving paper rolls for conveyance to a roll changer of a rotary printing press. 
   While a preferred embodiment of a device for changing a direction of travel of a conveying or a transport device, in accordance with the present invention has been set forth fully and completely hereinabove, it will be apparent to one of skill in the art that a number of changes in, for example the sizes of the conveying carts, the type of rotary printing press used with the device, and the like could be made without departing from the true spirit and scope of the present invention which is accordingly to be limited only by the following claims.