ZA200202139B - Supporting structure for a continuous conveyng installation. - Google Patents

Description

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Description

Support Frame for a Continuous Conveyor

The inventions relates to a support frame for a continuous conveyor with a driven belt

Continuous conveyors with a continuous roller-supported belt of steel cables or a textile imbedded in an elastomer are intended for transporting loose and particulate materials that are moved by such a system horizontally or at an angle upward or downward. When the transport path is short a drive is provided at one end of the belt. Longer conveyors have drives at both ends and in some cases there are also additional intermediate drives between the ends, so-called support/drive belt systems. The number of these latter drives is normally limited in the prior art to a maximum of five. The strength of the belt is dependent mainly on the length of the transport path, the center spacing of the support or drive rollers, the type of conveyor, as well as the capacity of the drives. The transport capacity and speed of the conveyor determine the belt width.

According to the prior art, such systems are known where the belt is provided on its underside with a throughgoing rib engaged at short spacings by small drives. Such drives can increase the capacity of the belt according to need, but the overall height of the conveyor is increased in order to make enough room between the outgoing and returning belt stretches to provide enough space for these drives. In addition the support and drive

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AMENDED SHEET v " v 2 rollers must be designed to provide room for the rib. In practice the drives must grip the rib in order to have enough traction. This produces a high load-creating resistance.

The strength limits of the belt and different path topographies mean that in practice the conveyor must be in sections, that is several conveyors are arranged in a row and the material being conveyed must be passed from the one belt to the next one.

In US 3 625 339 a conveyor in a framework construction is described in which even the drive units are integrated in the framework. The conveyor is separated in several conveying section which are connected by flexible couplings which consist in a detachable bolt connection preventing a horizontal displacement of the single framework sections to each other but allows adjustments of the heights.

US 4 880 109 relates to a chain-hauled conveyor belt with a frame in which supporting rollers are integrated. With the conveyor belt a chain is connected about which the conveyor belt can be moved by a drive unit located at the end and one or more intermediate drive units. The respective drive units are connected rigidly with the frame.

Starting from this state of the art, a need exists to provide a modularly constructed conveyor system comprising prefabricated units that can be used as drive-region components and also as a support frame and that as a result

AMENDED SHEET

2a of their construction can be put together to any desired transport length with a single endless interconnected belt without division into individual sections.

This need is fulfilled by the support frame according to claim 1. This frame is formed as a self-supporting three-dimensional truss. The advantage of such a support frame is that all loads that are created by the drives and that are reactions to belt tension and deflection forces are carried internally by the framework so that only the weight of the conveyor is passed outside. The three-dimensional framework can be made in any desired length and if necessary can be extended. If one uses

. - we Cy # 2 1 3 G @ framework parts where the upright struts have a common length, the length of the support frame is a whole-number multiple of this spacing. The three-dimensional framework has the shape of a rectangular tube that can be loaded greatly in all directions.

The appropriate endless belt is thus formed by a plurality of individual belt sections connected together by coupling elements. Such belt sections can be about 100 m long and have on their ends a releasable coupling. e.g. belt-joining hooks, or can be joined together by vulcanization into an endless belt. The technical limits are only limited by the standard drive techniques and the belt strength. With only a single drive all the acceleration, braking, or stationary loads must be carried by the belt that must have a corresponding breaking strength. In order to split up this load, several drives are used, e.g. a head drive and a footdrive and/or intermediate drives. According to the state of the art individual drive loads are substantially greater than 100 kW.

This leads with the use of intermediate drives to considerable axle lengths of e.g. 150 m for each intermediate drive so that the load that is transmitted per meter by each intermediate drive is about 1 kW. If on the contrary smaller intermediate drive loads are selected and one uses several more closely spaced intermediate drives, with e.g. loads of e.g. 11 kW or 22 kW, the transmitted load per meter of each intermediate drive drops to about 2 kW. If one uses the same part on which the forces must be transmitted by only a single drive, instead of a number n intermediate drives, it follows that each intermediate drive must only carry 1/n of the overall load.

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As a result the strength of the belt need only be 1/n as great. Generally the spacing difference between two adjacent intermediate drives is determined by the topography, that is with a horizontal run the intermediate-drive spacing can be greater than when on an incline.

Further embodiments of the invention are described in the dependent claims.

Thus the trusses each have right- and left-hand vertically oriented frame subassemblies that are each formed by a horizontal upper chord, an also horizontal lower chord, vertical struts, and diagonal struts that form a flat frame subassembly for carrying all the vertical loads in the support frame. In order to be statically in tune, the structure has a number n of connections and a number s of bars to satisfy the equation 2n = s + 3.

The two adjacent vertical frame subassemblies are interconnected either by spacer struts or roller supports, the spacer struts or roller supports being mounted by stirrup wedge connectors that engage eye plates on the support frames and that are connected solidly together by inserted wedges.

The spacer struts and roller supports are arranged perpendicular to the lateral parallel frame subassemblies (except in curves as described below). The employed wedge connection has the advantage of simple assembly and disassembly. At base however other connections of the individual frame modules are possible.

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In addition each lower chord is connected by holders to rollers supporting the lower belt stretch.

According to a preferred embodiment of the invention the upper chord and the lower chord of a support frame are provided at their ends with stirrup wedge connectors that engage eye plates on upright struts so that inserted wedges can solidly interconnect them. In this manner the eye plates at the end can be used to connect to a further support frame so that the two support frames form a single extended unit. The described eye plates each have a central hole of the same cross- sectional shape as a strut and four 90° offset slots through which wedges are insertable. According to a particular embodiment of the invention the eye plates are of square shape with the slots in the corners. A strut can be passed through the central hole of an eye plate or an eye plate can be slid over a strut so that the eye plate itself forms a perpendicularly projecting ring around the strut. The slots serve for receiving a wedge that forms the connection means of the eye plate with the stirrup wedge connectors. The stirrup wedge connectors each preferably have a head with a groove whose width corresponds to the thickness of an eye plate. The head further has holes opening into both sides of the groove that when fitted with the plate align with the eye-plate slot so that the stirrup wedge connector can be solidly connected to the eye plate via an inserted wedge. Angles of the wedge, of the holes of the eye plate, and of the stirrup wedge connector

@ are smaller than the friction angle of the employed materials.

In this manner a self-locking wedge connection is formed.

According to a further embodiment a plurality of upright connector elements have eyes at their upper ends by means of which the support frame can be suspended clear of the ground.

Such hanger eyes must be able to support the full weight of the conveyor (support frame with drives and conveyor belt) including any load being conveyed but need carry no further load. In order to be able if necessary to stand the frame on the ground, preferably a plurality of upright connector elements are insertable at their lower ends in supports.

According to a further embodiment upper-belt-reach support rollers are journaled at each end in a respective holder that has a recess for receiving a support-roller shaft of which at least one support piece end, preferably both support piece ends, are connected with a spacer strut. Preferably the journals for the support rollers are recessed relative to the roller support plane so that, on disconnection of the roller, the belt is supported by the roller support itself. In this manner damage to the conveyor belt is effectively avoided.

The above-described embodiments relate to support frames that are mainly set up for straight transport. This is because the greatest resistance moment of the support frame only permits bending inside the elastic bend line with a very large radius of curvature. In order to make curves of smaller radius of curvature, one-piece angle connectors are used that comprise two eye plates that have axes inclined at an acute angle to

@ each other. The angle connectors have two holes corresponding to the cross-sectional shape of the vertical struts and can be . slid over adjacent struts that are set relative to each other at the angle and spacing of the holes. Such angle connectors are then used in opposite points of the upright frame subassemblies. The actual angle defined by the axes of the two joined parts of the plate can be for example 5°. If a greater curvature is desired, a plurality of pairs of struts connected by such angle connectors can be used. The minimal radius of curvature in the vertical or horizontal direction that if exceeded will lose contact with the belt at corners is determined at this location by the force applied to the belt and its stiffness. The general use of intermediate drives as described above holds forces in the belts correspondingly low so that loss of the belt on curves is countered and in curves a horizontal guiding of the belt is possible without increasing the curve inner radius. One can also take into account that the intermediate drives are not too close to the curved region of the support frame and that a belt of correspondingly low stiffness and strength can be used.

According to a further embodiment of the invention in order to accommodate intermediate drives for receiving drive or deflecting drums, side plates are provided that are formed of an upper cord, a lower chord, and an intermediate middle chord and that carry, preferably between the middle chord and the upper cord, a holder for one end of the drive or deflecting roller. Such side plates are mounted on opposite side of the vertical planar frame subassemblies. The two opposite side plates are connected together by spacer struts and a roller support.

These intermediate drives are integrated in accordance with the local tension or load needs at a spacing of the overall conveyor length in the support frame. To this end it is advantageous that each intermediate drive has the same capacity. In a horizontally oriented conveyor the spacing of the individual intermediate drives is the same. When the conveyor for topographical reasons is horizontal and has rising and falling sections, the spacing of the intermediate drives is shorter in the angled sections.

Instead of the normal triangular tension curve present in a conveyor belt with only one drive with a very high maximum force, here there is a sawtooth-shaped force curve with the same "tooth height" along the belt with the maximum force substantially reduced.

The modular construction of the support frame according to the invention permits preferably the connection of a plurality of individual interconnected support frames to a corresponding extended support frame.

Further description and embodiments of the invention are described with reference to the drawing. Therein:

FIG. la is a schematic representation of a frame subassembly;

FIG. 1b is a schematic representation of a spacer strut with end-mounted stirrup wedge connectors;

FIG. 1c is a schematic representation of a roller support for securing on an upper chord;

FIG. 1d is a spacer strut with end-mounted stirrup wedge connectors and holders for the support-roller socket at a lower chord;

FIG. 2a is a section of a double spacer strut for holding the support rollers at the upper chord;

FIG. 2b is a section of a one-ended spacer strut for holding the support rollers at the upper chord;

FIGS. 3a, 3b are side views of a vertical strut carrying eye plates;

FIG. 3c is a side view of a stirrup wedge connector;

FIG. 3d is a top view between a stirrup wedge connector and an eye plate;

FIG. 4a is a side view of a horizontal angle connector;

FIG. 4b is a stop view of this angle connector with two vertical struts;

FIG. 4c is a top view of an upwardly deflected angle connector;

FIG. 4d is a side view of this angle connector with two vertical struts;

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FIG. 4e is a top view of an angle connector bent downward;

FIG. 5 is a side view of a side plate for supporting a deflecting or drive roller;

FIGS. 6a, b are cross sections through the support frame of FIG. 1a;

FIG. 7 is a side view of an intermediate drive; and

FIGS. 8a through c are schematic side views of a complete support frame with drive, deflecting, and intermediate drives (FIGS. 8b and 8c).

Trusses and the connection of the individual truss chords are known in construction so that in this regard standard engineering knowledge is relied on. What is new is the use of such a truss in support frames and integrated drives for continuous conveyors. The support frame 100 in FIG. 1 is comprised of an upper chord 101, a lower chord 102, vertical struts 103 to 112 perpendicular to the chords 101 and 102, and diagonal struts 113 to 117 that together form a planar frame subassembly that even when quite long can support substantial vertical loads. The ends of the upper chord 101 and of the lower chord 10 have stirrup wedge connectors 118 to 121 that are connected with the struts shown in FIGS. 3a and 3b. In addition the lower chord 102 is provided between the vertical struts 104 to 112 with holders 122 to 125 which can receive the ends of rollers carrying the lower belt stretch. The vertical struts 101 to 112 as well as the lower chord have eye plates 126 to 134 that are more closely described with reference to FIG. 3d. The length of the

® frame subassembly 100 as support frame is limited by the load applied to it which it must statically carry. To the right _ and left of the belt is one such planar support frame 100.

These support frames 100 are maintained vertical either with spacer struts 150 (See FIG. 1b) or with roller supports 160 (See FIG. 1c) by means of stirrup wedge connectors 151, 152, 161, and 162 on eye plates 126 to 1134 by means of a fastening wedge.

The roller support shown in FIG. lc has all the holding points 163 to 166 for the rollers supporting and guiding the upper belt stretch, FIG. 6a showing three rollers of which the two outer rollers form an angle to the middle roller. These rollers form the channel for a belt. If necessary the channel angle can be changed by the adjustable holder struts 167 and 168. The roller support 160 has at both ends stirrup wedge connectors 161 and 162. The three-dimensional truss assembly is shown in FIGS. 6a and 6b. In this three-dimensional truss all the loads in the system are accounted for so that even loads that for example result from the drive forces and reactions thereto and that are conducted out of the system can be taken care of. Only the weight of the system is actually transmitted outside the system and it can be carried by hangers or supports.

FIG. 1d shows a spacer strut 170 that preferably connects the side plates 500 shown in FIG. 5. n order tc hold the ends of the rollers carrying the lower belt stretch the spacer strut 170 is provided with holders 173, 174, 176, and 177.

Preferably the center of the spacer strut 170 is provided with an eye plate 175 level

N with the eye plate 130 of the support frame 100 shown in

FIG.la. The spacer strut 150 of FIG. 1b ensures a bend-free - connection by the stirrup wedge connectors 151 and 152. The connection with the side plates of FIG. 5 is effective by means of the stirrup wedge connectors 171 and 172.

FIG. 2a shows the roller support 160 as a double spacer strut 212 with the central roller 204 between the spacer struts 203 and 205. FIG. 2b shows an embodiment with a one-ended spacer strut 211 where the central roller 204 is arranged in the transport direction upstream or downstream of the spacer strut 208. In connections with vertical struts, e.g. 126 and 127, of the support frame 100, the arrangement of FIG. 2b allows a reduced roller spacing with the same construction of the support frame that for the same reasons is desired or necessary in parts of the overall system. Reduction of the spacing between adjacent rollers in the transport direction is often desired in the region where the bulk and/or particulate material is loaded on. The connection points 207 and 212 for the support rollers 204 of the upper belt stretch are recessed or outside the reach of the belt. This has the advantage that if one or more rollers are dropped by the roller support 160 the moving belt will contact no sharp edges that could longitudinally slit or destroy it. In case of a loss of one or more rollers of the roller support the belt engages the surface of the roller support 160.

FIG. 3a shows a connector element 300 for connecting adjacent support frames 100. In the illustrated case two eye plates 301 and 301 surrounding connector elements 300 are fixed with the support frames 100. As shown in FIG. 3d the eye plate is of square

@ shape. The eye plate has a central, in this case circular, hole 300 whose radius corresponds to the radius of the

So connector. element 300 or is slightly larger to provide a : necessary play. It has four holes 311 to 314 so that one eye plate can join up to four stirrup-connectors 320 extending at right angles to one another. The stirrup wedge connector 320 has a head with a groove whose width corresponds to the thickness of the eye plate 301. In addition this head has throughgoing holes through which a wedge 325 can be inserted .

If the eye plate is fitted as shown in FIG. 3d to the groove of the head of a stirrup supporter 320, the hole 313 is aligned with the described hole in the stirrup wedge connector so that an inserted wedge 325 ensures a solid connection of a stirrup wedge connector with the eye plate and thus with the connector element 300. The embodiment shown in FIGS. 3a, 3c,and 3d provides a right-angle connection of the connector element 300 with a spacer strut, a support frame 100, or a roller support. The shape of the stirrup wedge connectors 320 ensures a good fit while the wedge 325 creates a force- transmitting connection. The angle of the wedge is selected such that it is smaller than the friction angle of the employed materials. This creates self-locking so that overall a high-load fitted force-transmitting connection is created.

The upper end of the connector element 300 can have a hanger point 303 constituted as an eye by means of which the entire conveyor can be supported above the floor at the connectors 300. The lower end of the connector elements 300 can be constructed such that it can be inserted in industry-standard support feet so that if necessary the conveyor can stand on the ground.

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FIG. 3b shows a connector element 330 that carries three eye plates 331, 332, and 333 that can serve to connect two spacer struts. 150, two support frames 100 and/or a side plate 500 as : shown in FIG. 5.

FIG. 4a shows an angle connector 403 by means of which two struts 401 and 402 (see FIG. 4b) can be connected. This angle connector is comprised mainly of two eye plates and has two spaced adjacent circular holes 401 and 411 whose radius is the same size as the radius of the struts 401 and 402. In addition the angle connector 403 has slits 404 to 409 for receiving a wedge 325. The axes 412 and 413 are inclined at an angle to each other so that two support frames with end struts 401 and 402 with appropriate wedge connectors at the slots 406 and 409 can be connected with each other at an angle a. The respective slots 405 and 407 or 404 and 408 are at right angles to the slots 406 and 409 so that at each of the adjacent support frames 100 a right-angle connection to horizontal spacer struts is possible. If the illustrated angle is insufficient for the desired bend in the transport path, if necessary several angle connectors 403 with respective struts 401 and 402 can be set one after the other so that the desired arc can be produced by a corresponding partial polygon.

FIG. 4c shows an angle connector 423 whose individual eye plates are connected together at a bend line 426 so that the respective axes 424 and 425 extend at an angle to each other so that with such an angle connector that allows a relative canting of the struts 401 it is possible to upwardly deflect the support frame (from left to right). Correspondingly

AMENDED SHEET o there is also the angle connector 433 that is formed of two eye plates joined at a bend line 436 so that the corresponding canting of the axes 434 and 435 creates a downward deflection of the support frame.

FIG. 5 shows a side view of a side plate 500 that serves for holding a drive or deflecting roller. The side plate has an upper chord 501, a center chord 502, and a lower chord 503.

Between the upper chord 501 and the center chord S02 there is a holder 504 for an end of a schematically illustrated drive or idler roller 505. The chords 501 to 503 as well as the holder 504 are connected by vertical struts 506 and 507 such that the ends of the individual chords project as stirrup wedge connectors 508 to 513. The side plate 500 is arranged at the same level as the transport device to the right and left on the ends or between two planar support frames 100. Opposite side plates 500 are connected by means of spacer struts 150 corresponding to the embodiment shown in FIG. 3. The cord connector 512 is shown schematically. The securing means and other accessories known in the art are not shown.

FIG. 6a shows a rectangular tubular truss assembly that is formed by two vertical planar trusses 100 according to FIG. 1 as well as spacer struts 150 and roller supports 160 that are connected as described above. In this case the belt is guided by the angled rollers 601 to 603.

FIG. 6b shows a section through the truss assembly 630 in a section at the side plates 500 where in

_ addition an extra spacer strut 150 is provided to connect the side plate in the region of the central belt plane.

Side plates 500 that are provided within the support frame serve for carrying an intermediate drive 520 shown in FIG. 7 which has extra spacer struts 150 and stiffeners 170. The belt hangs down between the employed roller spacer struts (without the intermediate drive), the extent of the downward hanging being determined by the spacing of the roller spacer struts. This downward hanging can be used as a normal force component to the support belt of an intermediate drive that delivers a corresponding force to the belt.

FIGS. 8a to 8c show side views of different continuous conveyors that are formed of the individually above-described elements. The length of the conveyor is formed by the concatenation of several, here three, trusses 100 that are connected together via respective fitting 300. At the ends of the truss assembly there are side plates 500 for holding a drive and a deflecting drum that drive and support the endless belt.

In the embodiment of FIG. 8b there are additional side plate 500 with intermediate drives 520 according to FIG. 7.

In the embodiment according to FIG. 8c there are several three-dimensional trusses between the end drive 730 and reverser 720 as well as several intermediate drives 721. The number of intermediate drives used serves to minimize the maximal forces effective on the endless conveyor belt.

AMENDED SHEET o& l6a

The claims which follow are to be considered an integral part of the present disclosure. Reference numbers (directed to the ~~ ._ drawings) shown in the claims serve to facilitate the correlation of integers of the claims with illustrated features of the preferred embodiment (s), but are not intended to restrict in any way the language of the claims to what is shown in the drawings, unless the contrary is clearly apparent from the context.

Claims (22)

AMENDED SHEET Claims

1. A support frame for a continuous conveyor with a driven belt, the frame being formed as a self-supporting three- dimensional truss (100, 150, 160; 600; 630) having right- and left-hand vertically oriented frame subassemblies (100) that are each formed by a horizontal upper chord (101), an also horizontal lower chord (102), vertical struts (103 to 112), and diagonal struts (113 to 117) wherein the vertical frame subassemblies (100) are interconnected by spacer struts (150) and/or roller supports (160), the spacer struts (150) or roller supports (160) being mounted by stirrup wedge connectors (151, 152; 161, 162) that engage eye plates (301) on the support frames (100) and that are connected solidly together by an inserted wedge (325) that the truss internally carries all loads that are created by the drives and that are reactions to belt tension and deflection forces.

2. The support frame according to claim 1, wherein each lower chord (103) is connected by holders (122 to 125) to rollers supporting the lower belt stretch.

3. The support frame according to one of claims 1 or 2, wherein the upper chord (101) and the lower chord (102) of a support frame (100) are provided at their ends with stirrup wedge connectors (118 to 121) that engage eye plates (301) on upright struts (300) so that inserted wedges (325) can solidly interconnect them.

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4. The support frame according to any one of claims 1 to 3, wherein the eye plates (301) each have a central hole (304) of the same cross-sectional shape as a strut (300 or BN 330) and four 90° offset slots (311 to 314) through which wedges (325) are insertable.

5. The support frame according to claim 4, wherein the eye plates (301) are of generally square shape.

6. The support frame according to any one of claims 1 to 5, wherein the stirrup wedge connectors (320) each have a head with a groove whose width corresponds to the thickness of an eye plate (301), the head having holes opening into both sides of the groove that when fitted with the plate (301) align with the eye-plate slot (313) so that the stirrup wedge connector (320) can be connected sclidly with the eye plate (301) via an inserted wedge (325).

7. The support frame according to claim 6, wherein angles of the wedge (325), of the holes (311 to 314) of the eye plate (301), and of the stirrup wedge connector (320) are smaller than the friction angle of the employed materials.

8. The support frame according to any one of claims 1 to 7, wherein a plurality of upright connector elements (300, 330) have eyes (333, 334) at their upper ends by means of which the support frame can be suspended clear of the ground.

9. The support frame according to any one of claims 1 to 8, wherein a plurality of upright connector elements (300, 330) are insertable at their lower ends in supports.

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10. The support frame according to any one of claims 1 to 9, wherein upper-belt-reach support rollers (204) are journaled at each end in a respective holder (292, 211) oo that has a recess for receiving a support-roller shaft (207, 212) of which at least one support piece end are connected with a spacer strut (203, 205, 208).

11. The support frame according to claim 10, wherein both support piece ends are connected with a spacer strut (203, 205, 208).

12. The support frame according to one of claims 10 or 11, wherein the journals for the support rollers are recessed relative to the roller support plane (160, 167, 168).

13. The support frame according to any one of claims 2 to 10, wherein two eye plates have axes (412, 413; 424, 425; 434, 435) inclined at an acute angle to each other and form a one-piece angle connector (403, 4233, 433) and hold two vertical struts (401, 402) that together form a nonstraight connection of two support frames.

14. The support frame according to any one of claims 1 to 13, wherein, in order to accommodate intermediate drives for receiving drive or deflecting drums (505), side plates (500) are provided that are formed of an upper cord (501), a lower chord (503), and an intermediate middle chord (502) and that carry a holder (504) for one end of the drive or deflecting roller (505).

AMENDED SHEET 1%a

15. The support frame according to claim 14, wherein the side plates (500) carry a holder (504) between the middle chord (502) and the upper chord (501).

16. The support frame according to one of claims 14 or 15, wherein the two opposite side plates (500) are connected together by spacer struts (150) and a roller support

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17. The support frame according to any one of claims 1 to 16, wherein a plurality of intermediate drives (520) are provided.

18. The support frame according to claim 17, wherein the plurality of intermediate drives (520) are supported by means of side plates (500).

19. The support frame according to any one of claims 1 to 18, wherein an elongated support frame is formed by a plurality of individual interconnected support frames (100).

20. The support frame including any new and inventive integer or combination of integers, substantially as herein described.

21. The support frame according to the invention, as hereinbefore generally described.

22. The support frame as specifically described with reference to or as illustrated in the accompanying drawings.