US2892534A - Conveyor belt training assembly - Google Patents

Description

June 30, 1959 c. T. OGDEN CONVEYOR BELT TRAINING ASSEMBLY 3 Sheets-Sheet 1 INVENTOR. Charles T Ogden AT ORNEY Filed June 27, 1957 June 30, 1959 c. T. OGDEN 2,892,534

conve or; BELT TRAINING ASSEMBLY Filed June 27, 1957 3 Sheets-Sheet 2 IN V EN TOR.

- Charles T Ogden 4 m A ORNEV June 30,1959 T, 'Q D N 2,892,534

CONVEYOR BELT TRAINING ASSEMBLY Filed June 2'7, 195'? 3 Sheets-Sheet 3 IN VE N TOR BY Charles T Ogd A ORNE V United States Patent 9 CONVEYOR BELT TRAINING ASSEMBLY Charles T. Ogden, Chicago, 111., assign'or to Goodman Manufacturing Company, Chicago, 111., a corporation of Illinois Application June 27, 1957, Serial No. 668,445

12 Claims. (Cl. 198-202) This invention relates to belt conveyors and particularly to an improved belt training troughing assembly for a flexible strand sideframe conveyor.

A conveyor belt will run off-center under certain load conditions and, where the load condition varies, it may continually hunt from side to side. Improper installation may cause a belt to run off to one side. This is serious enough sometimes to actually dump the load. To correct such a condition, where the service warrants it, belt training roller assemblies are installed at intervals in the line and these automatically train or steer the belt back toward center when it becomes too far off. Customarily it is only the upper, or load-carrying reach, which is provided with these automatic re-training assemblies.

Now, flexible strand sideframe conveyors, such as disclosed in Craggs and McCann Patent No. 2,773,257, dated December 4, 1956, normally do not require as many training assemblies as conventional rigid sideframe conveyors. Where needed however they pose a special set of problems because the load-carrying reach is in a state of constant vertical motion, bobbing up and down under varying loads and as a result the training roller assemblies developed for rigid sideframe conveyors do not work satisfactorily. Attempts have been made to mount the conventional assemblies on springs, beneath the loadcarrying reach, so they will follow the up and down motion of the load-carrying reach, but these have not been successful because of the inherently different load-deflection rates of springs and flexible strands.

Accordingly, a primary object of the present invention is the provision of a training assembly for a flexible strand sideframe conveyor which is entirely supported on the flexible strand sideframes themselves and is thus free to deflect up and down with the strands under varying loads and at exactly the same rates as the strands themselves. Another object in such an assembly is elimination of a vertical rock shaft often employed for rigid side frame conveyors and which detract from useable head room.

Other objects and advantages will be apparent from the following description taken in connection with the drawings in which:

Figure l is a plan view of a rope or flexible strand sideframe conveyor employing one preferred form of automatic belt training roller assembly according to the present invention;

Figure 2 is an enlarged fragmentary view of Figure 1;

Figure 3 is a fragmentary cross sectional view of Figure 2, taken along line 33; I

Figure 4 is a plan view, similar to Figure l, of the training roller assembly showing effective cooperation with the flexible strands in automatically re-training the belt when off-center;

Figure 5 is a view similar to Figure 2 of a modified form of the invention with built-in time delay means;

i and Figure 6 is a fragmentary sectional view of Figure 5 taken along the line 6-6.

Like parts are referred to by like reference characters throughout the figures of the drawings.

Referring now more particularly to the drawings, a pair of flexible strands 11, 12 are trained in generally parallel relation along a course and suitably tensioned at their ends to effectively support a conveyor and load. The tensioning means is not specifically disclosed here because it forms no part of the present invention. For suitable tensio-ning means, together with a detailed description of flexible strand sideframe conveyors, reference should be made to the above-mentioned Craggs and Mc- Cann Patent No. 2,773,257.

The strands are supported above the ground and spaced a preferred distance apart by spreader- stands 13, 13 at regular intervals along the line.

Transversely flexible troughing assemblies 14, 14 are connected across the strands, at regular intervals, and Where needed, one of the troughing assemblies 14 will be substituted by a training roller assembly 16 which will automatically bring the load-carrying reach 17 of a belt 13 back into train whenever it attempts to deviate more than a certain amount beyond center. The belt has a return reach 19 which is supported on return rollers 21 carried by the spreader-stands 13. It will be obvious as this description proceeds that the self-training feature of the training assembly 16 may be employed in the return rollers 21 where desired.

The training assembly 16 comprises a pair of laterally spaced generally parallel slide shafts 22, 22, each having a slide block 23 slideably mounted for longitudinal forward and backward reciprocation thereon. A sleeve bushing 24, as for example bronze, may be employed to minimize wear. Each shaft 22 has a pair of connecting brackets or clamps 26, 27 connected to the ends thereof, as by means of rivets or pins 28. Each clamp 26, 27 is curved, as shown in Figure 3, for embracing one of the ropes, and is locked in place by wedge-shaped drift pins 2? driven through holes in the upper and lower segments of the clamps.

Each slide block 23 is biased to a position on its corresponding slide shaft 22 by means including coil springs 31, 32 encircling the shaft, and bearing respectively against opposite faces of the slide block. The springs are seated on their other ends on washers 33, 34 held in place by snap rings 36, 37 engaged in suitable grooves formed in the shaft.

A troughing assembly generally designated 38 may be similar to that disclosed in Craggs and McCann Patent No. 2,773,257 and is here shown as a transversely flexible series of three rollers 39 rotatable on shafts 41. The shafts are interconnected between rollers, for relative pivotal movement in a vertical plane, about links 42, each of which provides a pair of axes 43, 44, note Fig. 5, extending longitudinally of the conveyor. Each end shaft is connected to a corresponding one of the slide blocks 23 by a pivot pin 4-6.. As will be seen, other types of troughi-ng roller assemblies may be employed such for instance as that disclosed in co-pending Smith application Serial No. 655,594, filed April 29, 1957, for Flexible Troughing Roller Assembly for Belt Conveyor.

At each end of the troughing assembly 38 there is pro vided an upstanding belt engaging member such as a curved shoe 47 positioned to engage the edge of the loadcarrying reach 17 when the latter is off-center far enough to rub against it.

In operation, assuming the load-carrying reach of the beit passes from right to left according to the arrow in Figure 4, and assuming further that the belt reach detrains (upward in Figures 1 and 4) against the shoe 47, the frictional engagement will shift the block 23 to the left against the compressive bias of the spring 31; this will cause the entire troughing assembly 38 to pivot as a unit about the opposite pin 46, that is from the broken line to the solid line positions shown in Figure 4, thereby steering the load-carrying reach toward the center, away from the upper shoe 4'].

Now considering the condition where the belt is reversed, spring 32 comes into action and permits the roller assembly to be re-oriented in the opposite direction.

Similar corrective re-orientations of the roller assembly occur automatically when the belt becomes de-trained in the other direction, that is against the bottom shoe in in Figures 1 and 4.

Obviously, if the belt were to be run from right to left all the time, only springs 31 would be needed.

Note that, in Figure 4, when the roller assembly swings, the flexible strands likewise swing inwardly to enable free shifting of the block along the slide shaft.

As will be seen in Figures and 6, the troughing roller assembly 38 may be connected to a mounting on each end which provides somewhat of a time delay in the shifting of the troughing assembly from an angular or corrective position to a normal transverse position. This is similar to the embodiment described for Figures 1-4 except that the slide shaft 22 is replaced by a shaft 52 having a rack or toothed portion 52a facing the inner portion of the conveyor. A pinion 53 meshes with the rack and is keyed onto a shaft 54 rotatably mounted in bearings 56, 56 in upper and lower legs of U-cross section slide member 57. -The member 57 has fixed, as by welding at each end, an annular washer 58 encircling the shaft 52. Each end shaft 41 of the troughing roller assembly 38 is pivotally connected to the slide member 57 by a generally vertical pivot pin 59. Atop the shaft 54 is mounted a belt engaging member such as a friction roller 61.

In operation, when the edge 62 of the belt de-trains sufficiently to engage the upstanding roller 61, the frictional engagement will rotate the roller and the pinion 53 in a direction to shift the slide member 57 and the end of the roller assembly 38 to an angular disposition which will train the belt back toward center. In some cases it is desirable that the roller assembly 38 remain in the corrective, angular position (broken lines in Figure 5) long enough to urge the belt substantially back to the center. This is achieved in the Figures 5 and 6 embodiment by the arrangement shown. For instance, assume the frictional engagement of the edge 62 of the belt with the roller 61 shifts the slide member 57 to the left in Figure 5. As soon as the belt moves away from the roller 61, the spring 31 will begin to shift the slide 57 back to its normal, centered position. To do so, in the Figures 5 and 6 embodiment, requires that the pinion 53 be backdriven through the rack 52a. This takes some time and provides suflicient delay to get the belt substantially back to the middle of the conveyor.

While forms in which the present invention may be embodied have been shown and described, it will be understood that various modifications and variations thereof may be effected without departing from the spirit and scope of the invention as defined by the appended claims.

I claim:

1. A training assembly for a belt conveyor comprising a pair of laterally spaced generally parallel shafts, connecting means carried by said shafts for mounting the shafts to flexible strand means, a movable member mounted for reciprocable movement on each of said shafts, an elongated troughing assembly extending laterally between said shafts, means connecting each end portion of said troughing assembly to a corresponding one of said movable members, means biasing both of said members in at least one direction on their respective shafts, and a belt engaging member connected to each one of said movable members and being effective, responsive to engagement with a belt moving across said troughing assembly in a direction opposite said one direction, to move the engaged member in said opposite direction against said biasing means along said shaft for reorienting said troughing assembly to train such belt away from said engaged member.

2. A training assembly according to claim 1 in which said troughing assembly is flexible transversely of its length to facilitate re-orientation thereof to a position to train a belt away from the engaged member.

3. A training assembly according to claim 1 in which said troughing assembly is pivoted to each of said movable members about an axis which is substantially normal to a plane common to both of said shafts to facilitate reorientation of said troughing assembly in a position to train a belt away from the engaged member.

4. A training assembly according to claim 1 in which said biasing means comprises a spring carried by each of said shafts and seated against the respective movable member.

5. A training assembly for a belt conveyor comprising a pair of laterally spaced generally parallel shafts, connecting means carried by said shafts for mounting the shafts to flexible strand means, a movable member mounted for reciprocable movement on each of said shafts, an elongated troughing assembly extending laterally between said shafts, means connecting each end portion of said troughing assembly to a corresponding one of said movable members, means biasing each of said members toward an intermediate position on the respective shaft so the movable member is movable in either longitudinal direction against said biasing means, and a friction shoe at each end of said troughing assembly operably connected with a corresponding one of said movable members and being effective, responsive to engagement with a belt moving across said troughing assembly to move the engaged shoe in the same direction against the bias of said biasing means for re-orienting said troughing assembly to train such belt away from said engaged shoe.

6. In a flexible strand sideframe conveyor including, in combination, a pair of flexible strands trained along generally parallel courses and having opposed portions which are transversely flexible toward and away from one another, a pair of slide shafts disposed generally parallel to said strands at said opposed strand portions, clamp means connecting the end portions of each of said shafts to the respective opposed strand portion, a slide member mounted for reciprocable movement on each of said shafts, a troughing roller assembly including a series of roller supporting members having belt-supporting rollers thereon and pivotally interconnected about axes generally parallel to said strands with each of the end roller supporting members of said series being pivotally connected to one of said slide members about an axis generally normal to a plane including the respective opposed strand portion, a belt running in one direction across said rollers, a spring encircling each of said slide shafts and bearing against the corresponding slide member to bias the slide member in a direction opposite the direction of movement of said belt, a belt engaging member carried by each slide member and disposed for engagement by an edge of said belt when running offcenter and effective in response to said engagement to shift said troughing roller assembly as a unit against the bias of the spring to a position to train the belt toward a centered position on the troughing roller assembly with said opposed strand portions flexing toward one another to accommodate such unitary shifting of the troughing roller assembly.

7. A training assembly for a belt conveyor comprising a pair of laterally spaced generally parallel shafts, connecting means carried by said shafts for mounting the shafts to flexible strand means, a movable member mounted for reciprocable movement on each of said shafts, an elongated troughing assembly extending laterally between said shafts, means connecting each end portion of said troughing assembly to a corresponding one of said movable members, means biasing both of said members in at least one direction on their respective shafts, and a belt engaging member at each end of said troughing assembly rotatably connected with a corresponding one of said movable members, a driving connection between each corresponding belt engaging member and movable member for moving the latter along its corresponding shaft responsive to rotation of the belt engaging member, said belt engaging member being effective, responsive to frictional engagement with a belt moving across said troughing assembly in a direction opposite said one direction, to rotate and move said movable member in said opposite direction against said biasing means along said shaft for re-orienting said troughing assembly to train such belt away from said engaged member.

8. The training assembly according to claim 7, wherein each of said driving connections includes a pinion engaged with a rack, said pinion being connected for rotation with the respective rotatable belt engaging member and said rack being fixed relative to the corresponding one of said shafts.

9. In a flexible sideframe conveyor assembly having flexible strand means, a flexible troughing assembly carried by said strand means and connecting means for connecting the troughing assembly to the strand means, the improvement comprising, in combination with the connecting means, a training means for training a movable conveyor belt which is supported by the troughing assembly, said training means including a shaft, clamping means for clamping said shaft to the strand means, a slide member mounted for longitudinal reciprocal movement on said shaft, means for securing an end of the troughing assembly to the slide member, means biasing said slide member in at least one direction along the shaft, belt engaging means connected to the slide member and adapted to engage an edge of a conveyor belt whereby, said slide member and the end of the troughing assembly may be moved in a direction against the biasing means for re-orienting the troughing assembly to train a conveyor belt away from the belt engaging means.

10. A flexible troughing assembly having connector means for connecting the troughing assembly to a flexible strand means, said connecting means including a training means for training an end-less belt which may be supported by the troughing assembly, said training means comprising a pair of spaced generally parallel shafts, a slide member mounted for longitudinal reciprocal movement on each of said shafts, means biasing said slide members in at least one direction along the respective shaft, belt engaging means connected to each slide member and adapted to engage an edge of aconveyor belt, said troughing assembly being connected to and extending between the slide members and securing means for securing each of the shafts to a flexible strand means whereby, either slide member may be moved longitudinally along the respective shaft when the belt engaging means which is connected thereto engages a conveyor belt supported by the troughing assembly and will train such belt relative thereto.

11. The flexible troughing assembly as set forth in claim 10, wherein each of said belt engaging means comprises an anti-friction roller element adapted for rolling engagement with an edge of a conveyor belt.

12. The flexible troughing assembly as set forth in claim 10, wherein each of said belt engaging means comprises an anti-friction roller element having a pinion mounted thereon for common rotation therewith, said roller element being adapted to have rolling engagement with an edge of a conveyor belt and a rack on each of said shafts in operative engagement with the respective pinion.

References Cited in the file of this patent UNITED STATES PATENTS 2,773,257 Craggs et al. Dec. 4, 1956 2,776,044 Lo Presti Ian. 1, 1957 FOREIGN PATENTS 19,953 Great Britain June 10, 1905

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