US2727390A - Sampler - Google Patents

Description

Dec. 20, 1955 Filed Dec. 12, 1951 FIG. 1.

J. B. HOUSTON ET AL SAMPLER 4 Sheets-Sheet l INVENTORS mamas BJ'KOUSTON Dec. 20, 1955 J. B. HOUSTON ET AL SAMPLER 4 Sheets-Sheet 2 Filed Dec. 12, 1951 FIG. 2.

INVENTORS JRCQUES B.HOU$TON R g- PH v- H PPER 3TI RNEY De c. 20, 1955 J. B. HOUSTON ETAL SAMPLER 4 Sheets-Sheet 5 Filed Dec. 12, 1951 INVENTORS JfiCiQUES B.HOUESTON R ES LP? ,H PPER 52% ETTORNEY Dec. 20, 1955 Filed Dec. 12, 1951 J. B. HOUSTON ET AL. 2,727,390

SAMPLER 4 Sheets-Sheet 4 FICiS.

;.-2 WEIGHTOMIETBR INVENTORS JFSCQUES B. 3 3C) USTON mama v. fi PP/ R EITOR E United States Patent SAMPLER Jacques B. Houston and Ralph V. Hopper, Baton Rouge,

La., assignors to Kaiser Aluminum 8; Chemical Corporation, Oakland, Calif., a corporation of Deiaware Application December 12, 1951, serial No. 261,256

8 Claims. (Cl. 73-423) This invention relates to devices for collecting samples of ore or other granular and pulverulent material.

More particularly, it concerns apparatus for obtaining a sample of ore or other like material, wherein a sampling bucket or receptacle is moved into and out of a moving stream of the material to be sampled, together with novel means for actuating the sampling receptacle.

Many sampling devices have been developed in the past for taking samples from a continuous moving stream of ore material. These sampling devices were so constructed that they would first move into the moving stream of material and then out, while carrying a sample of the material collected. Various timing devices were used for actuating such samplers at a predetermined time.

However, these sampling devices ordinarily delivered a representative portion or cut collected or taken from the moving stream to points well below the elevation of the initial sampling point. This necessitated the use of further auxiliary equipment for elevating the cut or sample so that it could be treated later by means of rifiles or other secondary samplers, if it was desired to have primary rejects flow by gravity back into the main stream of material.

Also, the samplers of the past generally moved horizontally through the falling stream of material, thereby collecting one side of the stream of material at an earlier period of time than the other side with the result that a truly representative cross section of material was not obtained. in the case of ore material falling ofi an endless conveyor belt, ore material of difierent coarseness or density generally moves along the belt and there are times, when at one section of the moving belt there is material, while at other sections there is no material. In taking samples of such material, it is highly desirable to get a representative portion of the whole. For this purpose, a simple timer operated sampling device is ordinarily unsatisfactory. In addition, a more representative analysis may be obtained, if samples are taken from weighed portions of the whole.

The sampling device of the instant invention overcomes the above disadvantages of other samplers. This sampler is generally comprised of an open-top container that is adapted to be moved vertically down into the falling stream of a material to be sampled, then upwardly and out of the moving stream to an elevated position. Whereas other samplers deliver representative portions or cuts of material at points considerably below the elevation of the sampling point, the sampler of the instant invention delivers its cuts to a point that can be any convenient number of feet above the elevation of the sampling point. This feature allows convenient treatment of each cut by means of rifiles or other secondary samplers at any suitable elevation from which all rejects can be made to flow by gravity back into the main stream of material. There is, therefore, no need for accessory equipment to elevate primary rejects for disposal. This feature also allows ample head room for appropriate treatment of the cuts or fractions thereof by a crusher and secondary sampler, such as rifiles or other forms of splitters, all of which are well known in the art.

To insure catching no more of the material from the upper part of the stream than is proper, the velocity of downward travel of the top edge of the container part of the sampling device can be advantgeously adjusted so that it will be slightly faster than the greatest velocity of a free falling particle of material to be sampled. When the container is moved at the proper minimum velocity, no material falls into it until the sampling point is reached, then the entire stream may be caught and the container filled. The open top of the container may also be made larger than the horizontal cross section of the falling stream at the sampling point, so that a truly representative cross section of the stream may be collected.

The sampler may be actuated by any suitable means, such as an air cylinder, said air cylinder being actuated in response to one of a series of electrical impulses from a weighing device, such as Weightometer, which continousiy weighs the material to be sampled as it is moved past a designated weighing point by the conveyor. In this way, samples may be taken directly from weighed portions of the whole, thereby remedying the defects .of other timer operated samplers.

Accordingly, one object of this invention is to provide a novel sampling device, which is adapted to discharge the representative portions or cuts collected at a point well above the elevation of the sampling point.

Another object of this invention is to provide a novel open-top sampling container or receptacle that is moved vertically down into a falling stream of material, the containers top opening being larger than the horizontal cross section of the falling stream at the sampling point and with the velocity of downward travel of the top edge of the container through the falling material being adjusted so that it is made slightly faster than the greatest velocity of a free falling particle of the material, thereby preventing material from falling into the container until the sampling point is reached, and obtaining a truly representative cross section of the entire stream being sampled.

Another object of this invention is to provide novel means for actuating the sampling receptacle of a sampler device so that it will collect samples of material directly from previously weighed portions of the material as these portions are ejected oif the end of an endless conveyor belt.

Another object of this invention is the provision of a novel sampling receptacle having an end member or gate pivotally mounted at the bottom thereof, along with external guide means for keeping the gate member closed until the receptacle has been properly elevated to the dumping point, at which time the guide means terminate and the weight of the loose material inside the receptacle is then allowed to force the pivotally mounted end member open, whereby the contents of the receptacle can be discharged therefrom.

A further object of this invention is to provide a novel sampling receptacle, which is adapted to move into and out of a falling stream of material, together with novel means for automatically operating the sampling receptacle at predetermined times.

Other objects and advantages of the invention will become more apparent from the following detailed description, when taken in conjunction with the accompanying drawing wherein:

Figure 1 is a side elevational view partially broken of the sampling device located at the head end of an endless belt conveyor;

Figure 2 is an end elevational view partially broken of the sampling device, when taken along-the line 22 of Figure 1, and with parts removed for the sake of clarity;

Figure 3 is a side elevational view of the container or receptacle for the sampling device;

Figure 4 is a plan view of the sampling device and conveyor of Figure 1, when taken along line 4-4 thereof; and

Figure 5 is a schematic diagram of one type of electrical circuit which may be employed for making the operation of the sampling receptacle automatic.

Referring more particularly to the drawings in which the same reference numerals have been applied to the like parts in the various views, it will be observed that the sampling device of the instant invention is generally comprised of a suitable upstanding framework 1. This framework in turn may be comprised of a plurality of upstanding spaced frame members 4, 5, 6 and 7 and horizontal frame members 4, 5', 6', 7 and 8'. These frame members are so arranged as to form a suitable vertical shaft 8 for the container 9 of the sampling device. The upstanding frame members may be connected by suitable bridging and reinforcing members 10 and 10 located therebetween.

By referring to Figure 1, it will be noted that these frame members are advantageously located near the head pulley 2 of an endless conveyor belt 3 at the point where the conveyor discharges into a main delivery chute 11. This main chute 11 is in turn provided with a main auxiliary chute 13 and secondary chutes 14 and 15. Chutes 14 and 15 are connected to a suitable primary sampling splitter 16, well known in the art, in such a way that the material ultimately to be sampled can be carried off by chute 14 to a suitable sampling point and the primary rejects of the sample taken may be returned by auxiliary chute 15 to the main stream flowing through chute 13 to another conveyor, secondary auxiliary chute 15 being in open communication with main auxiliary chute 13.

The sampling container 9, which is adapted to be lowered and raised in the shaft 8 into and out of the moving stream of material 17, being discharged from the con-' veyor 3, is comprised of a sloping end wall 18, upstanding side walls 19 and 20 and a second end wall 21 which also serves as a discharge gate. This gate 21 is advantageously pivotally attached at the bottom thereof between the side walls 19 and 20. Carrier arms 22 and 23 are connected to and project upwardly from the side walls 19 and 20. The arms are also connected to a cross bar 24 and the intermediate part of this cross bar is aflixed to a piston rod 25 adapted to reciprocate in the pneumatic cylinder 26 attached by suitable means to the frame members 5 and 7. A pair of short guide members 28 and 29 also disposed within the shaft 8 extend along the path taken by the container 9 being located on the same side of the shaft as the pivoted end or gate 21 of the container 9. These guide members can be attached if desired to the cross braces 10. It will be observed by referring to Figure 1 that the upper extremities of guides 28 and 29 terminate approximately at the point where it is desirable to discharge the sample collected from the moving stream of material into the splitter 16.

The sloping end member 18 of the sample container 9, whose top opening is larger than the horizontal cross section of the falling stream at the sampling point, is positioned at an angle to the horizontal plane, which angle is substantially steeper than the angle of repose of the material to be sampled which collected in the receptacle, thereby facilitating the flow of material out of the container at the time it is discharged into the splitter 16.

From the above discussion, it will be seen that sample container 18 travels up and down in shaft 8 and into and out of the moving stream of material 17, being actuated by the pneumatic cylinder and piston 26 and 25 in a manner to be more fully described later. During the time the sample is being taken, guides 28 and 29 prevent the gate 21 from opening until the container is elevated to the point where the splitter 16 is located. At this point the guides 28 and 29 terminate, and the force of sampling A material within the container which presses against the gate 21 is no longer restrained. The gate then flops down, thereby discharging the sample cut of material into the splitter 16.

In the preferred embodiment of the invention, the sampling container 9 is actuated and moved down into the moving stream of ore material, which is discharged in a trajectory and falls into the space or shaft 8, by means of a pneumatic cylinder 26, and piston rod 25. Cylinder 26 is advantageously electrically connected to a conventional Weightometer 30 associated with conveyor belt 3. By the electrical connections, which will be more fully discussed later, between the air cylinder 26 and Weightometer 30, the sample container can be brought to the low or sampling point position and held there for a longer time than is required for filling. The holding time can be made adjustable to suit any rate of delivery by the conveyor.

As the container is moved into the sampling position, the open top of the container passes through horizons 56 and 51. If it were held at horizon 50, the upper part of the falling stream would barely begin to be caugfi in the container. If it were held at horizon 51, the container would barely begin to catch the lowest part of the falling stream. To insure catching the sample from all parts of the stream at once, the downward stroke of piston rod 25 can be adjusted so that the sampling will take place a little below horizon 51. To insure catching no more of the material from the upper part of the stream than is proper, the downward stroke of piston rod 25 can also be adjusted so that the velocity of downward travel of the top edge of the container l through the distance from horizon 50 to horizon 51 will be slightly faster than the greatest velocity of a free falling particle of material past horizon 51. When the container is moved at the proper minimum velocity, no material falls into it until the sampling point is reached, then the entire stream is caught and the container 9 is filled.

After the preselected holding time, the air cylinder operates to draw the filled container to its high or dumping point. As stated above, the pivotally mounted end member 21 is prevented from opening by the guides 23 and 29 until the container passes the upper end of those guides immediately below the dumping point. After those guides have been passed, the pivotally mounted end member is forced outward by pressure of the loose material inside. End member 21 then falls by gravity to a sloping position within the delivery chute and the sample cut flows out of the container by gravity. End member 21 remains open until the next descent of the container when movement past guides 28 and 29 forces it to close.

Figure 4 is a schematic electrical diagram showing one way in which an electrical impulse from a weighing device, such as a Weightometer, associated with the conveyor belt may be used to actuate the sampling receptacle 9. The type of weighing device or Weightometer employed sends out electrical impulses, each impulse representing a fixed unit of weight. In using a conventional Weightometer, the weight of material passing the Weighing point is determined by the speed of the conveyor and the relative deflection of the belt downward toward the Weightometer under the weight of the material on the belt. The term Weightometer is a registered trade-mark of the Merrick Scale Company, Passaic, New Jersey, and is illustrative of the type of apparatus which may be employed in association with our conveyor belt for the purposes of carrying out this invention. A Weightometer Model No. E may be employed with satisfactory results. The operation of such a device is fully disclosed and described in Patent 2,367,775. While the use of a Weightometer of the type aforesaid is preferred, it is to be understood that other suitable devices possessing the functions of a Weightometer may be employed in lieu thereof. The circuit of Figure 4 is merely an illustration of one means of accomplishing the automatic operation of the sampling receptacle or bucket 9.

In one mode of operation the Weightometer can be set so that it sends out one impulse for every ton of material which passes the weighing point. The circuit disclosed may be used where it is desired to take a sample of material for a specific number of tons, for example, a sample from every 20 tons, passing the weighing point, and in particular to take a sample of the material which was weighed on the weighing device or Weightometer, i. e. the 20th ton. To do this, some means is necessary for taking the desired impulse and holding the same signal for the length of time necessary for the sample to travel the length of the belt from the weighing point to the head of the conveyor Where the sample is taken.

Accordingly, the Weightometer 3% is set so that every time a ton of material passes the weighing point cam 30a of the Weightometer is actuated so as to momentarily close switch 3% whereby an impulse is sent out which momentarily closes the circuit from line L2 through terminals C and M on a motor driven ratchet type counter 70 of conventional design, terminal C being connected to line L2 and terminal M in turn ieading to line L1, thereby moving the ratchet R of the counter one count. Each of these impulses is thus registered on the counter and at a predetermined setting, for example, 20, a cam 80 aflixed to the ratchet R of the counter is adapted to close the spring-type switch 31 long enough to close the circuit between terminal N and terminal P of the counter and cause the energization of relay 83. When relay 33 is energized, it acts to close its normally open switch 83a and to open normally closed switch 83b, thereby causing the energization of relay 84, whereupon relay 84 acts to close normally open switches 84a and 84c and to open normally closed switch 84b, switch 8442 being a holding type of switch. Relay 84 maintains itself through the normally closed switch 86a and through the normally open switch 84a, which is now closed. When relay 84 is energized, it closes normally open switch 840, thereby starting the timer 90 while opening normally closed switch 34b, thus opening the circuit to terminal S on the counter 70 which releases a suitable magnetic clutch A between the ratchet counter and the motor for operating the ratchet, thereby stopping the counter, which then resets itself: In the meantime relay 83 has been de-energized, as cam 80 on the ratchet R loses contact with switch 81, thereby opening the circuit to relay 33. As relay 83 becomes deenergized it causes normally closed switch 83b to close again impressing line L2 voltage on terminal S. The counter is again made ready to receive impulses from the Weightometer.

In the meantime, the timer 9'9, which was initially actuated by the closing of switch 84c and is adjusted so that it is synchronized with the speed of the conveyor belt, delays the action of the sampling receptacle until the material which caused the counter 70 to indicate the predetermined weight (in this case, the weight of the 20th ton) has reached the point where it is discharged from the conveyor belt. The timer then oper tes to close a contact, whereby voltage is impressed on relay 85 through terminals E or F of the timer, thereby energizing the same. When relay 85 is energized, it closes switch 85a, thereby causing action of a suitable solenoid-operated valve 95 on the air cylinder 25, thereby actuating piston 26 and the sampling bucket. Relay 35 is energized for a sufficient time to allow the sampling bucket to move downward to the sampling position.

After a su1table time interval has elapsed, the timer then operates to cause the energization of relay 86 by closing a contact between terminals F and B. When relay 86 is energized it opens normally closed switch 86a, thereby breaking the circuit on relay 84 and de-energizing relay 84. When relay 84 drops out, it opens switch 84c, breaks the circuit to the timer, and allows the timer to reset itself automatically, thereby clearing the way for the next operation. In the meantime as the timer is deenergized, relays 85 and 86 also become de-energized and switch 85a is opened, whereby valve is then operated to cause the retraction of piston rod 26 which then moves the sampling container upward to its discharge position.

While the form of apparatus herein described and the circuits for controlling said apparatus constitute preferred embodiments of the invention, it is to be understood that the invention is not limited thereto and that various changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

1. In a sampling device, the combination of a plurality of frame members, so arranged as to form an open shaft, short guide members located on one side of said shaft, means for discharging a moving stream of material to be sampled into the said shaft, and an opentopped sampling bucket adapted to reciprocate in the said shaft between the said frame members and to move into and out of said moving stream of material so as to collect a sample thereof, cylinder and piston means for actuating said bucket, said bucket including spaced side members, a sloping and fixed end member, and a gate member pivotally attached at the bottom thereof and forming the other end of said bucket, said bucket being so disposed between the frame members defining the said shaft that the gate member is on the same side of the shaft as the guide members of short length, whereby said gate member will contact said short guide members and remain closed when said bucket is moved along said shaft into the moving stream of material, and whereby said gate member will open to discharge the contents of the bucket when the said bucket is moved away from said stream of material along said shaft to a predetermined point, and contact between the said gate member and said short guide members is lost.

2. In a sampling device, the combination of a plurality of frame members so arranged as to form an open vertical shaft therebetween, short guide members on one side of said shaft, means for discharging a stream of material to be sampled into the said shaft at a point below the tops of said short guide members, and an open-topped sampling bucket adapted to move up and down in the said shaft between the said frame members and into and out of said stream of material, so as to collect a sample thereof, cylinder and piston means for actuating said bucket, said bucket having spaced side members, a fixed end member and a gate member pivotally attached at the bottom thereof and forming the other end of said bucket, said bucket being so disposed between the frame members defining the said shaft that the gate member thereof is on the same side of the shaft as the guide members of short length, whereby said gate member will be in contact with said short guide members and remain closed when said bucket is moved along said shaft into a sampling position and whereby said gate member will automatically open to allow the discharge of the contents of the bucket when the bucket is moved upward and away from said moving stream of material for a predetermined distance and contact is lost between the said gate member and said short guide members.

3. The combination of claim 2, wherein the fixed end member of said bucket is positioned at an angle to a horizontal plane, said angle being substantially steeper than the angle of repose of the material being sampled, where-' by the flow of material out of said bucket is facilitated when said gate member is opened.

4. In a sampling device, the combination of a plurality of frame members so arranged as to form an open vertical shaft, short guide members on the one side of said shaft, a conveyor for discharging a stream of material to be sampled into the said shaft at a point below the tops of said short guide members, a Weightometer, means for attaching said Weightometer to said conveyor for weighing said material on said conveyor prior to discharging said material in a stream into the said shaft, an opentopped sampling bucket adapted to move up and down in the said shaft between the said frame members and into and out of said stream of material so as to collect a sample therefrom, said bucket having spaced side members, a fixed end member and a gate member pivotally mounted at the bottom thereof and forming the other end of said bucket, said bucket being so disposed between said frame members defining the said shaft that the gate member thereof is located on the same side of the shaft as the guide members of short length, whereby said gate member will be in contact with said short guide members and remain closed when said bucket is moved along said shaft into a sampling position and whereby said gate member will automatically open to allow the discharge of the contents of the bucket when the bucket is elevated away from said stream of material to a point where contact is lost between the said gate member and said short guide members, air cylinder means for operating said bucket, and electrical means for connecting said air cylinder to said Weightometer whereby said bucket may be raised and lowered in said shaft at predetermined intervals of time.

5. In a sampling device, the combination of a plurality of frame members so arranged as to form an open vertical shaft, short guide members located on the one side of said shaft, a conveyor for discharging a stream of material to be sampled into the said shaft at a point below the tops of said short guide members, a Weightometer, means for attaching said Weightometer to said conveyor for weighing said material on said conveyor prior to the discharging of said material in a stream into the said shaft, an open-topped sampling bucket adapted to move up and down in the said shaft between the said frame members and into and out of said stream of material so as to collect a sample therefrom, said bucket having spaced side members, a fixed end member and a gate member pivotally mounted at the bottom thereof and forming the other end of said bucket, said bucket being so disposed between the said frame members defining said shaft that the gate member is located on the same side of the shaft as the guide members of short lengths, whereby said gate member will be in contact with said short guide members and remain closed, when said bucket is moved along said shaft into a sampling position and whereby said gate member will automatically open to allow the contents of the bucket to be discharged therefrom, when the bucket is elevated away from said stream of material to a point where contact is lost between the gate member and the said short guide members, air cylinder means for operating said bucket, and means including a counter and a timer for electrically connecting said Weightometer to said cylinder whereby said bucket may be alternately raised and lowered in said shaft at predetermined intervals so as to collect a sample of the material directly weighed on the said conveyor by said Weightometer and thereafter ejected into the said shaft.

6. In a sampling device the combination of a plurality of frame members so arranged as to form an open shaft, a conveyor for discharging a moving stream of material to be sampled into the said shaft at one portion thereof, an open-topped sampling bucket adapted to move back and forth in the said shaft into and out of said stream of material discharged into the said shaft so as to collect a sample therefrom and thereafter remove the sample collected to a discharge station, air cylinder means for actuating said bucket, a Weightometer, means for attaching said Weightometer to said conveyor for weighing said material on said conveyor prior to the discharge thereof into the said shaft, and electrical means for connecting said Weightometer to said cylinder, and for actuating said cylinder whereby said bucket may be a1- ternately moved back and forth into and out of said stream of material in said shaft at predetermined intervals of time.

7. In a sampling device, the combination of a plurality of frame members so arranged as to form an open shaft, a conveyor for discharging a moving stream of material to be sampled into the said shaft at one portion thereof, an open topped sampling bucket adapted to move back and forth in the said shaft and into and out of said stream of material discharged into the shaft so as to collect a sample therefrom and thereafter convey it to a discharge station spaced from said moving stream, air cylinder means for operating said bucket, a Weightometer, means for attaching said Weightometer to said conveyor for weighing said material on said conveyor prior to the discharge thereof into the said shaft, and means including a counter and timer for electrically connecting said Weightometer to said cylinder means and for actuating said cylinder, whereby said bucket may be ternately raised and lowered in said shaft at predetermined intervals so as to collect a sample of the material directly weighed on the said conveyor by the said Weightometer.

8. in a sampling device, the combination of a plurality of frame members so arranged as to form an open shaft, short guide members located on one side of said shaft, means for discharging a moving stream of material to be sampled into said shaft, and an open-topped sampling bucket adapted to reciprocate in the said shaft between the said frame members and to move into and out of said moving stream of material so as to collect a sample thereof, electromechanical means for operating said bucket, said bucket including spaced side members, a sloping and fixed end member, and a gate member pivotally attached at the bottom thereof and forming the other end of said bucket, said bucket being so disposed between the frame members defining the said shaft that the gate member is on the same side of the shaft as the guide members of short length, whereby said gate member will contact said short guide members and remain closed when said bucket is moved along said shaft into the moving stream of material and whereby said gate member will open to discharge the contents of the bucket when the said bucket is moved away from the said stream of material on said shaft to a predetermined point and contact is lost between the said gate member and said short guide members, and the sloping fixed end member of said bucket being arranged at an angle substantially steeper than the angle of repose of the material being sampled, whereby the flow of material out of the bucket is facilitated when said gate member is opened.

References Cited in the file of this patent UNITED STATES PATENTS

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