US1803689A - Conveyer control - Google Patents

Description

W. H. BERNADT CONVEYER CONTROL May 5, 1931.

Filed Dec. 27, 1929 Z0617 fer 7i: Bernadi Famed May 5, 1931 UNITED... stares. OFFICE WALTER n. tsi srgatqgm ou Appllcationl ill ed w 27; 192's." seriariwo. 418,806.

grading apparatus upon a succession of belt conveyers and in some instances it is discharged from one conveyer directly onto another. It sometimes happens that the path of travel of the coke from its starting point to the point where it is discharged for final disposal is broken as a result of the stopping or slowing up in speed of one of the conveyers or the choking of the crushers or 2 grizzlies. When this occurs, unless the conveyers which are delivering the coke to the disabled mechanism are stopped, an accumulation of the coke develops which increases to a point where its overflow occurs. This 7 requires an interruption in the operation of the entire line of conveyers, crushers and graders until the material has been cleared away by hand shoveling, the time required to do this depending upon the elapsed time be- $9 tween the breakdown of the conveyer or other mechanism andthe stopping of the line of feed conveyers. 4

The principal object of the present invention is to provide a device to be used in conjunction with conveyers, crushers, grizzlies and other mechanisms which will become efl'ective immediately, upon the accumulation of material in the path of travel beyond a predetermined height, to sto the conveyer or conveyers which are feed ng the material to that point where the excessive accumulation has commenced.

The device is designed to stop the feed conveyers before the accumulation referred to has reached a point where overflow occurs and as a result therefore, no hand shoveling, with the resultant loss of time, is necessary and immediately upon the repair of the defective mechanism the entire line of mechanisms may be started at once.

one application of my invention.

s The invention is illustrated in the accompanym'g drawings in which Figure ,I-i's. a vertical section of a grizzly and feeding mechanism therefor showing Figure12is an end elevation of the same. Figure3Ishows the control mechanism in conjunction with a. ho per which is arranged to facilitate the transt dr of the material from one conveyer to another. While the invention is described in connection with treating and conveying of coke it is to be understood that such description is merely for purposes of illustration and that in fact the invention is available for other mechanisms and purposes so long as the electrical conductivity ofthe material being acted upon is suitable for the purposes in view.

The control mechanism is illustrated in Figures 1 and 2 in connection with a grizzly 4 and a feed conveyer 5 therefor, only the essential parts of the apparatus being shown for purposes of clarity. The feed conveyer 5 may be driven by an electric motor 5a. The grizzly 4 includes spaced bars 6 which provide screening openings 7. The coke orother material is discharged from the feed conveyer 5 onto the grizzly 4- down which it rolls to a chute 8 from whence it may be carried away in any suitable manner. In the passage of the material from the feed conveyer to the discharge chute 8, however, the smaller particles are separated therefrom by the grizzly 4, the finer particles of the material 35 passing through the openings 7 and dropping upon a conveyer 9 which is positioned beneath the grizzly and which is adapted to convey them to a dilferent point of discharge. The construction described to this point is 90 representative of apparatus for grading coke and is standard equipment.

In the grading of the coke it may ha' pen 1 that the screening openings in the grid become choked or one of the conveyers 8 and 9 breaks down or slows up appreciably. Upon such an occurrence if the conveyer 5 continues to deliver its usual flow of material, the material accumulates and rapidly reaches a point where it overflows its path.

This requires its subsequent handling by hand and also chokes up parts of the apparatus. The amount of material accumulating in the path of flow and overflowing the same depends, of course, upon the time that the feeding conveyers continue in operation after a mechanism in the path of flow has become disabled.

In order to avoid such occurrences, I propose to employ a switch mechanism which is controlled by contact members positioned a-djacent the path of flow of the material being acted upon and in such relation therewith that if for any reason the material accunuilates in the path beyond a certain height a circuit is closed to operate the switch mechanism and break the circuit through the motor which is driving the conveyer or other mechanism feeding that portion of the apparatus where the accumulation has commenced.

The switch and automatic operating mechanism therefor which are indicated as a whole at C (Fig. 1) may be positioned wherever desired but are preferably located in the switch box containing the switches employed in connection with the other motors of the apparatus.

Means for starting the automatic switch operation mechanism is, as stated, positioned adjacent the path of flow of the material being acted upon at any number of points desired. As illustrated in Figuresl and 2 each of said means comprises pairs of depending contact arms 10 which are pivotally supported at their upper ends between brackets 11 secured to cross members 12. The cross members 12 may be supported by the side walls of the grizzly at such a distance from the bottom thereof that the contact arms are held-above the screening surface of the grizzly at such a height that in the normal operation of the apparatus the material passes beneath the said arms without touching them. The cross members 12 are, of course, insulated from the depending arms 10 and their supporting brackets. I

As illustrated in-Figure 1, the feed conveyer may be started by closing a circuit through the motor 5a. The circuit is closed by operating the hand switch 13 of the control 'mechanism C. A circuit is thereupon established through the A side of the power line, contacts 14 and 15, which are normally held closed by the spring 16a, switch 13, solenoid 16 and out the B side of the power line. The solenoid 16, upon being energized closes the switch 17 and the motor circuit is closed. The closing of the switch 17 however, also closes a circuit by means of wires 18 and 19 through the primary winding of a transformer 21. The secondary winding of the transformer forms part of a normally open circuit which includes wire 21grounded to the frame of the grizzly as at 22 and wire 23 which is connected to electric magnets 21. The circuit through wire 23 and magnets 24 continues through wires 25 to the binding posts 26 which are electrically connected through the brackets 11 to the arms 10.

It will thus be obvious that during the normal operation of the apparatus the secondary circuit will be open and the spring 16a will hold the contacts 14 and 15 closed to maintain the encrgization of the motor 5a. However, should the coke or other conductive material which is being treated back up against any one of the fingers 10, a closed circuit is established from that linger through the coke which has backed up beneath it, the frame of the grizzly, wire 21, magnets 24, wire 25 and the electric magnets 24 are therebyenergized to attract the armature 27 which opens the contacts 1 1 and 15 to break the motor circuit and stop the feed conveyer 5. Upon the clearing away of the material beneath the arms 10, the secondary circuit will be broken and a circuit will again be closed through the motor 511. It will thus be apparent that by utilizing the invention in the manner described a feed conveyer will be automatically stopped when the material beyond the discharge end thereof has reached a predetermined level and that any overflow of the material may, therefore, be effectually prevented.

In Figure 3 the invention is illustrated in connection with two conveyers with a hopper arranged between the two and adapted to facilitate the transfer of the material from one of the conveyersto the other. The feed conveyer 28 which is driven by motor 29 delivers the material into the hopper 30. The discharge mouth 31 of the hopper is arranged to deliver the material received from the feed conveyer 28 to a second conveyor 32 which is driven by the motor 33.

In connection with this modification of the invention it is to be noted that in grading and crushing coke, it is the practice to utilize such an arrangement of conveyers to receive the liner particles of coke from the grizzly and carry them to the ultimate point of discharge. In such an arrangement the hopper 30 would be positioned beneath the upper end of the conveyer 9 (illustrated in Iigure 1). In

other words the said conveyer 9 would be utilized to feed material to the hopper 30 instead of the conveyer 28 shown in Figure 3. In any event it is preferred that the motors for driving the various conveyers be adapted for independent starting, that is to say, have independent switches which permit them to be started preferably in sequence from the end of the line toward the beginning of the line. In such a construction the automatic control mechanisms are preferably arranged so as not only to stop the conveyer feeding directly to the point where the accumulation has commenced but also all of the conveyers in the line which precede it, the conveyers beyondthe point of accumulation continuing in operation-to clear that portion of the apparatus.

To this end, therefore, the motor 33 (Fi ure 3) is started first by closing the switcv 36. After the switch 36 has been closed, the

utilized in the first embodiment illustrated,

. I propose to employ contact fingers 34 which are preferably suspended by a support 35 from the inner wall of the hopper and over the discharge mouth of the same, the fingers 34 being insulated from the support 35 as at 35a. The secondary circuit of the transformer 20 includes wire 21 which may be grounded to the hopper 30, magnets 24 for operating'the armature 27 and wire 25 connected to the fingers 34. If for any reason the conveyer 32 should stop or, slacken its normal speed and the coke backup in the hopper to such a height as to contact with the fingers 34 the secondary circuit will be closed, utilizing the coke and hop 'er as part of the circuit, to break the circuit throu h the motor 28 as described in the first emb iment of the invention. While the circuit through motor 28 is broken the circuit through motor 33 will, of course, not be effected and the conveyer 32 willcontinue in operation. a

In both embodiments of the invention the relation between the primary and secondary windings of the transformers is preferably such that the voltage in the secondary circuits is not high enough to be dangerous to workmen. However, the current, voltage and frequency may be varied in order to meet different conditions such as, for exam le, materialsofiering different resistances to t e passage of current.

Having described my invention I claim 1. In a paratus for transferring electrically con uctive material from one point to another, a conveyer for delivering the material to a point of discharge, a motor operatively connected to said conveyer, a normally closed circuit through the motor, means arranged to provide a path of flow for the material discharged from said conveyer, contact means arranged adjacent the said means and electrically controlled means operable to break the circuit through said motor when the material in the path of flow has reached a height sufiicient to contact with said contact means, the said material providing a conductor between said contact means and said electrically controlled means.

2. In apparatus for transferring elec-.

trically conductive material from one point to another, a conveyer for delivering the material to a point of discharge, a motor operatively'connected to said conveyer, a normally closed circuitthrough the motor, means. arranged to provide a path of flow for the material discharged from said conveyer a contact member ivotall mounted adjacent said means an electrically controlled means operable to break the circuit .through said motor when :the material in the path. of flow has reached a height suflicient to contactwith said contact member, the

said material providing a conductor between said contact member and said electrically controlled means.

3. In apparatus for transferring material from one point to another, a conveyer for delivering the material to a point of dis-- charge, a motor'operatively connected to said conveyer, a' normally closed circuit through said motor, means arranged to provide a path of flow for the material discharged from said conveyer, automatic means for breaking the circuit throu h said motor said means including a trans ormer having its prlmary winding in the motor circuit, the

secondary winding of said transformer being included in a normally open secondary circuit and means adjacent the path of flow and adapted when the material in the path of flow has reached a predetermined height to close said secondary circuit.

4. In apparatus for transferring material from one point to another, a conveyer for delivering the material to apoint of .dis charge, a motor operatively connected to said conveyer, a normally closed circuit through said motor,-means arranged to provide a path of flow for the material discharged from said conveyer, automatic means for breaking the circuit through said motor comprising a transformer having its primary winding in the motor circuit, the secondary windingof said transformer be ing included in a normally open secondary circuit and means adjacent the path of flow and adapted when the material in the path of flow has reached a predetermined height to close the secondary circuit and effect the operation of said automatic means, said ma-' terial constituting a part of the said secondary circuit.

5. In apparatus for transferring electrically conductive materials from one point to another, a conveyer for delivering the materials to a point of discharge, a motor operatively connected to said conveyer, a normally closed circuit through said motor and automatic means for breaking the circuit through said motor comprising a transformer hating its primary winding in the motor circuit, a normally open secondary circuit including the secondary winding of said transformer, an electric magnet in said secondary circuit, means in said circuit arranged adjacent the path of flow of the materials and. ada ted when the materials therein have reached a predetermined height to cooperate 5 with said materials to close said secondary circuit, thereby to operate said magnet and break said motor circuit.

6. In apparatus for transferring electrically conductive materials from one point to another, a conveyer for delivering the materials to a point of discharge, a motor operatively connected to said conveyer, a normally closed circuit through said motor, a second conveyer for carryin oil the materials discharged from the rst mentioned conveyer, means arranged between the two conveyers for facilitating the transfer of the materials, contact means carried by said means, and electrically controlled means operable to break the motor circuit when the materials being transferred back up beyond their normal height to contact with said contact means, the said materials providing a conductor between said contact means and said electrically 25 controlled means.

' 7. In apparatus-for transferring electrically conductive materials from one point to another, a conveyer for delivering the materials to a point of discharge, a motor operatively connected to said conveyer, a normally closed circuit through said motor, a second conveyer for carrying oil. the materials discharged from said first mentioned conveyer, intermediate means arranged between the two conveyers for facilitating the transfer of the materials from one to the other, automatic means for breaking the circuit through said motor comprising an armature carrying a contact, a magnet for operating said armature, said magnet being included in a normally open circuit and contact means as a part of said circuit carried by said intermediate means and adapted to contact with the materials being conveyed should the materials back up in the intermediate means beyond a predetermined height, said materials being utilized in such case as a conductor to close the'normally open circuit through said magnet.

50 In testimony whereof I ailix my signature.

WALTER H. BERNADT.

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