Steep angle conveyor with articulated frames
BACKGROUND OF THE INVENTION 
     The present invention is directed to a steep angle conveyor for conveying bulk material or the like from one level to a higher level. The apparatus includes a lower conveyor frame which is supported on a lower surface by means of a lower drive mechanism and an upper conveyor frame which is supported on an upper surface by means of an upper drive mechanism, the lower and upper conveyor frames being connected by means of an intermediate frame. The frames accommodating a conveyor belt, one end of which is associated with a feeding device and the other end of which is associated with a discharging device. 
     German Utility Model No. 1,692,620 discloses a steep angle conveyor in which the conveyor belt is accommodated in a rigid conveyor frame which is able to operate only at an unchanging steep slope, with the vertical distance between the lower level and the upper level being fixed. 
     To compensate for irregular differences in height between the surfaces, it is also known to manufacture the conveyor frame of two telescoping parts. German Patent No. 942,079 discloses a configuration in which the conveyor is equipped with a vertical tower on which an adjustable-height bridge is disposed. However, these conveyors are very complicated in structure and, additionally, the vertical transport of material is very difficult. 
     To compensate for the differences in height between the lower and upper surfaces, it is further known (German Patent No. 3,217,745) to support a steep angle conveyor on only one drive mechanism, which is movable on the lower surface. The upper conveyor frame is designed as a pivotal cantilever which is held by a supporting frame having a counterbalancing cantilever and a cable winch device. This again involves high expenditures. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a steep angle conveyor of the above-mentioned type in which differences in height between the lower and upper drive mechanisms can be accommodated with simple means. 
     In the present invention this object is attained by using hinges to connect lower and upper conveyor frames to an intermediate frame, with the hinges having horizontal axes which are oriented transversely to the conveyor frames. The conveyor belt guided by the frames is an endless belt. 
     With an apparatus according to the invention, the intermediate frame can be brought to any position between the vertical and the horizontal. That is, the slope or inclination of the intermediate frame can be varied as desired between the vertical position and the horizontal position, without the horizontal or almost horizontal orientation of the lower and upper conveyor frames having to be changed. A further advantage is that an apparatus according to the invention is a bridge device which can be independently moved from one location to another. Particularly in pit operations, this device is able to move out of the pit on its own. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side view of a steep angle conveyor in accordance with the present invention. 
     FIG. 2 is a side view illustrating the lower point of articulation of the steep angle conveyor in enlarged detail. 
     FIG. 3 is a side view illustrating the upper point of articulation of the steep angle conveyor in enlarged detail. 
     FIG. 4 is a side view of the upper conveyor frame disposed at an angle with respect to the intermediate frame. 
     FIG. 5 is a side view of the upper conveyor frame disposed in a common horizontal plane with respect to the intermediate frame. 
     FIG. 6 is a side view illustrating, in enlarged detail, the support for the lower conveyor frame on the lower drive mechanism. 
     FIG. 7 is a side view illustrating, in enlarged detail, the support for the upper conveyor frame on the upper drive mechanism. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     With initial reference to FIG. 1, the steep angle conveyor 1 operates at a slope 3 between a lower surface 2 and an upper surface 4. Lower surface 2 may, for example, be the floor of an open pit mine. Essentially, the steep angle conveyor 1 is composed of a lower conveyor frame 5, an intermediate frame 13, and an upper conveyor frame 14, with an endless conveyor belt 10 being disposed in the conveyor frames. Conveyor belt 10, as described in more detail in the periodical &#34;bulk solids handling,&#34; Volume 4, No. 1, March 1984, pages 105-112 (published by Transtech Publications, P.O. Box 266, D-3392 Clausthal-Zellerfeld, Federal Republic of Germany), is provided with corrugated edge strips 10&#39; (FIG. 3) and with transverse cleats 10&#34; (FIG. 3) disposed therebetween to form pockets which permit material to be carried up a steep incline. Belt 10 is guided over a lower reversal roller 11 and an upper reversal roller 12, thus forming an upper belt segment 10a and a lower belt segment 10b. Belt 10 is moved by engines (not illustrated) that are coupled to rollers 11 and/or 12. 
     The lower conveyor frame 5 is connected with the intermediate frame 13 by means of a lower hinge 15 and the intermediate frame 13 is connected with the upper conveyor frame 14 by means of an upper hinge 16. The lower conveyor frame 5 is supported on the lower floor 2 by means of a lower drive mechanism 6 and the upper conveyor frame 14 is supported by an upper drive mechanism 17. Intermediate frame 13, lacking its own independent support, is indirectly supported by drive mechanisms 6 and 17 by virtue of its articulated connection to frames 5 and 6. Drive mechanisms 6 and 17, in addition to supporting conveyor 1, are vehicles which can move conveyor 1 as a unit from one place to another. For example, it may be possible to move conveyor 1 to a new location in an open pit mine, depending on the mine&#39;s layout, while lower drive mechanism 6 remains on surface 2 and upper drive mechanism 17 remains on surface 4. On the other hand it may be necessary to remove conveyor 1 from the mine, and FIG. 5 illustrates a portion of conveyor 1 when drive mechanisms 6 and 17 are disposed on a common horizontal plane so that conveyor 1 can be moved across either surface 2 or 4. At any rate, after conveyor 1 has been moved to the desired location the drive mechanisms 6 and 17 permit frames 5 and 14 to be positioned as necessary in view of the vertical distance between the surfaces 2 and 4. For example if lower surface 2 in FIG. 1 were illustrated one inch higher in the drawing, this change in height could be accommodated by moving frame 5 outward from the foot of slope 3. Thus while length of intermediate frame 13 is fixed, the angle α is not, and this variability permits frame 13 to span different heights as the need arises. 
     Turning next to FIG. 6, the connection between the lower conveyor frame 5 and the lower drive mechanism 6 is configured as a displaceable device 28 so that longitudinal displacements are possible between frame 5 and drive mechanism 6. For this purpose, device 28 is provided at drive mechanism 6 with a support frame 32 equipped with rollers 31. Frame 5 is supported on rollers 31 by means of rails 33 fastened to frame 32. Stops 39 are fastened to frame 5 at the ends of rails 33 to prevent frame 32 from rolling beyond rails 33. Support frame 32 is supported on an auxiliary frame 35 by means of a ball bearing turntable 34, and auxiliary frame 35 is in turn supported on drive mechanism 6 by means of a cardan or universal joint arrangement 36. It is desirable for frame 5 to be level even if the surface 2 on which drive mechanism 6 rests is not. To set or correct the angular position of frame 5 with respect to drive mechanism 6, two hydraulic cylinders 37 and 38 are disposed between auxiliary frame 35 and drive mechanism 6, one in the longitudinal plane and the other in the transverse plane of drive mechanism 6. With the aid of cylinders 37 and 38, different ground slopes can be accommodated. 
     Referring next to FIG. 7, the upper conveyor frame 14 is likewise connected with upper drive mechanism 17 so as to be pivotal about a vertical axis and about horizontal axes in the longitudinal and transverse directions. However a single displaceable device 28 (FIG. 6) is sufficient for protecting conveyor 1 from strains that would otherwise arise should drive mechanisms 6 and 17 be slightly too close together or too far apart, so a further displaceable device is not needed at drive mechanism 17. Frame 14 is supported on an auxiliary frame 35&#39; by a ball bearing turntable 34&#39; and auxiliary frame 35&#39; is supported on drive mechanism 17 by means of a cardan or universal joint arrangement 36&#39;. Between auxiliary frame 35&#39;0 and drive mechanism 17 there are provided two hydraulic cylinders 37&#39; and 38&#39;. 
     Returning to FIG. 1, in the region of lower conveyor frame 5, a feeding device 7 is provided which is composed of a feed funnel 8 and a feed belt 9. Feed belt 9 is provided for the purpose of reducing the height of the drop of the material to be transported when it is transferred to conveyor belt 10. 
     In the region of upper conveyor frame 14, a discharge device 18 is provided which has an associated discharge belt 19 placed on upper floor 4. 
     Referring next to FIGS. 2 and 4, in the region of hinge connections 15 and 16, between conveyor frames 5 and 14 and intermediate frame 13, a lower roller conveyor 20 and an upper roller conveyor 21 are provided to support the upper segment or run 10a of conveyor belt 10. Lower guide rollers 22 and upper guide rollers 23 are provided in the above-stated regions to support the lower segment or run 10b of conveyor belt 10. 
     As can be seen in FIG. 2, guide rollers 22a and 22b are provided in the connection region between frames 5 and 13. Depending on the angular position of intermediate frame 13, the upper run 10a of conveyor belt 10 rests on the two guide rollers 22a and possibly on the two guide rollers 22b. These rollers are arranged in such a manner that they participate in the pivoting movement of the frame sections. 
     Hinges 15 and 16 (see FIGS. 2 and 3) may be provided with hinge members 24 which are attached at cross beams 5a, 13a and 14a of frames 5, 13 and 14, each connected to the other by means of bolts 25. 
     While conveyor frames 5 and 14 hold the entire steep angle conveyor 1 in balance by suitably distributing its weight, it may be of advantage, in order to better stabilize the entire conveyor framework, to provide hydraulic cylinders 26 and 27 between lower conveyor frame 5 and intermediate frame 13 and/or between upper conveyor frame 14 and intermediate frame 13. 
     It will be understood that the above description of the present invention is susceptible to various modifications, changes and adaptations, and the same are intended to be comprehended within the meaning and range of equivalents of the appended claims.