Patent Publication Number: US-3875803-A

Title: Equipment for sampling bulk material

Description:
United States Patent 11 1 Clewlow l l EQUIPMENT FOR SAMPLING BULK MATERIAL l75| Inventor: William Michael Clewlow, Walton.  
 England [73] Assignee: Birtley Engineering Limited.  
 Chesterfield. Dcrhyshire. England [22} Filed: Sept. 5, I973 [211 App]. No.: 394,529  
 [30] Foreign Application Priority Data Sept. 20. 1972 United Kingdom 43470/71 [52] US. Cl .4 73/423 R [51] Int. Cl. G0ln 1/20 [58] Field of Search 73/421 R, 423 R [56] References Cited UNITED STATES PATENTS 2.727.390 l2/l955 Houston 73/423 Apr. 8, 1975 2.977.800 4/196! Jordison 73/423 Primary ExaminerS. Clement Swisher Attorney, Agent or Firm-Norris &amp; Bateman [57] ABSTRACT The invention relates to equipment for sampling bulk material as it falls in a stream and comprises a sample container adapted to be moved through the stream and to collect a sample therefrom, a discharge door in the sample container normally held in a closed position by resilient means. and a sample collection chute movable to and from a position in which it may collect a sample from the sample container, the chute being adapted to engage and open the discharge door as it moves to the position in which it may collect a sample from the sample container.  
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  1 EQUIPMENT FOR SAMPLING BULK MATERIAL This invention relates to equipment for taking sam ples of bulk material falling in a stream and relates in particular to equipment of the kind in which a sample container is caused to make sampling runs through the falling stream of bulk particulate material, such as, for example, minerals or any material in granular form, and to discharge the material collected therefrom.  
  In US. Pat. No. 3,54l,862 equipment of the kind referred to is described comprising a sample container mounted on a pair of spaced arms, which arms are mounted on a framework for pivotal movement about a pivot axis, the sample container and the arms being pivoted about the axis by means of one or more movable flexible transmission members. The described preferred embodiment of the above mentioned Patent utilises a sample container which has a discharge door which is held closed by a latch which is released automatically at the end of the sampling run to allow the discharge door to swing open and discharge the sample into a fixed sample collection chute. The discharge door is closed automatically during the initial part of the following sampling run by a suitably disposed abutment fixed to the framework of the equipment.  
  It is an object of the present invention to provide an improved or alternative means of effecting the opening and closing of the discharge door of a sample container of equipment of the kind referred to.  
  According to the invention equipment for sampling bulk material as it falls in a stream comprises a sample container movable through the stream in such a manner as to collect a sample therefrom, a discharge door in the sample container, resilient means carried by the sample container acting to hold the discharge door in a closed position, and a sample collection chute movable to and from a position in which it may collect a sample from the sample container, the chute being adapted to engage and open the discharge door against the action of the resilient means as it moves to the position in which it may collect a sample from the sample container.  
  The sample container will preferably be of trough form, with a pivotally attached bottom closure forming the discharge door. The resilient means, which are preferably torsion springs, must, of course, be strong enough to keep the discharge door closed against the weight of the sample collected within the sample container.  
  The sample collection chute is preferably pivotally mounted and may be moved pivotally to and from its sample collection position by any suitable means but we prefer to use a linear actuator for this purpose. The engagement between the chute and the discharge door is preferably by means ofa cam and cam follower roller carried by the chute and discharge door respectively.  
  In a preferred sequence of operations the sample container moves from a first, parked position and travels through the stream of falling bulk material to a second position and is then reversed to travel back from the second to the first position passing again through the stream of bulk material (the sample container thus collects a sample increment in each of its two runs through the stream). With the sample container back in the first position the sample collection chute is moved pivotally to its sample collection position and in so doing engages and opens the discharge door to allow the sample to be discharged into the chute, and the chute is then moved pivotally away from its sample collection position allowing the discharge door to close under the action of the resilient means in readiness for the next sampling run.  
  Whilst any suitable means may be utilised to cause the sample container to move through, and collect a sample from the stream of bulk material without departing from the scope of the invention, we prefer to locate the container at the end of a pair of pivoted arms, means being provided to move the arm pivotally and to swing the sample container through the stream of bulk material. In particular we prefer to use an arrangement whereby the arms are mounted on a shaft which has a driving wheel secured thereto. motion being imparted to the shaft by means of a flexible transmission member engaging the periphery of the driving wheel.  
  A preferred embodiment ofthe invention will now be described, by way of example, with reference to the accompanying drawings in which:  
  FIG. I is a plan view of equipment according to the invention,  
 FIG. 2 is a side elevation of the equipment,  
  FIG. 3 is a part side elevation showing the discharge chute in an inoperative position and FIG. 4 is a part side elevation showing the discharge chute in an operative, sample discharge position.  
  Referring firstly to FIGSv I and 2 the equipment has a base frame I of substantially rectangular shape. A shaft 2 is transversely mounted in the base frame 1 by bearings 3 and has a pair of spaced parallel arms 4 and an end pulley 5 mounted thereon. A sample collecting container 6 is mounted between the ends of the pair of arms 4 and the base frame is so positioned relative to the head drum 7 of a conveyor belt 8 by any suitable framework (not shown) that the arms in swinging from a parked position, as shown, to a position shown by the broken lines in FIG. 2 carry the container 6 through the bulk material stream 9 discharged from the end of the conveyor 8 thereby collecting a sample increment therefrom. To return the container 6 back to the parked position the arms are swung in the opposite direction and the container therefore passes twice through the bulk material stream 9, thereby collecting a sample increment in each of its passages in opposite directions through the bulk material stream 9. The sampling cycle may comprise one movement of the arms from and to the parked position whereby the collected sample consists of two sample increments or alternatively may comprise a plurality of such movements.  
  In order to actuate pivotal movement of the pair of arms 4 the apparatus has two hydraulic linear actuators l0 and 11, the rams I2 and 13 of which are connected to the ends of a steel rope I4 which engages approximately one half of the periphery of the pulley 5, the rope 14 preferably being anchored at one point to the pulley to prevent relative slip therebetween. With the arms in the parked position shown the ram 12 of actuator I0 is extended and the ram 13 of actuator 11 is retracted. The arms are swung downwardly by the retraction of the ram 12 of the actuator 10 and extension of the ram 13 of the actuator 11 thus causing the pulley 5 and the shaft 2 to rotate in a clockwise direction, as viewed in FIG. 2. On reaching the position shown by the broken lines the arms are brought to rest and the actuator ll will preferably be provided with a cushion head, which may. for example, be a dash pot on air trap, to ensure that the arms are gradually brought to rest. To swing the arms upwardly back to the parked position the ram 12 of the actuator is extended and the ram 13 ofthe actuator 11 is retracted thus rotating the pulley S and the shaft 2 in an anticlockwise direc tion. as viewed in FIG. 2. On reaching the parked position the arms are preferably held there by a directional valve on the actuator I]. The operation of the two actuators l0 and ll should be such that the sample collecting container 6 moves through the bulk material stream 9 with a uniform and equal speed in both directions and therefore collects a fair sample increment from the stream in each passage through the bulk material stream 9.  
  The collected sample is discharged from the sample collection container 6 by the actuation of pivotal discharge chute 15, the arrangement and manner of operation of which can be most clearly seen in FIGS. 3 and 4. The discharge chute 15 is provided with trunnions 16 which are mounted in flange bearings 17 carried by the base frame 1. A hydraulic linear actuator 18 is pivotally mounted at 19 on the base frame 1 and has its ram 20 pivotally connected to a lug 21 on the discharge chute 15. The discharge chute is normally held by the actuator 18 in the inoperative position shown in FIG. 3 in which it lies out of the arcuate path followed by the container 6 during its sample collection run. To remove a sample contained within the sample collecting container 6 the discharge chute is moved pivotally by the actuator 18 to the position shown in FIG. 4 and in so doing two cam surfaces 22 carried by the chute 15 contacts the rollers 23 carried on the two arms 24 disposed at either side of the container discharge door 25, which is hingedly connected to the container 6 at 28, thus opening the discharge door and allowing the sam ple to be discharged into chute 15. The discharge chute 15 is arranged to discharge the sample into a collection chute 26. After discharge of the sample the discharge chute 15 is moved back to the position shown in FIG. 3 and the discharge door 25 moves back to the closed position under the action of a torsion spring (not shown which spring is strong enough to keep the door in the closed position when a sample is contained within the container 6.  
  The linear actuators 10, 11 and 18 will preferably be operated by suitable control means to perform the sample collection and discharge cycle atuomatically but manual control could be used if so desired.  
 I claim:  
 1. Equipment for sampling bulk material as it falls in a stream comprising a sample container movable through the stream in such a manner as to collect a sample therefrom. a discharge door in the sample container. resilient means carried by the sample container acting to hold the discharge door in a closed position, and a sample collection chute movable to and from a position in which it may collect a sample from the sample container, the chute being adapted to engage and open the discharge door against the action of the resilient means as it moves to the position in which it may collect a sample from the sample container.  
  2. Equipment according to claim 1 wherein the sam&#39; ple container is mounted for pivotal movement and is adapted to move pivotally to and from its sample collection position.  
  3. Equipment according to claim 1 wherein the sample container is mounted on a pair of spaced arms, which arms are mounted for pivotal movement about a pivot axis for movement of the sample container along an arcuate path, and the sample collection chute when not in its sample collection position lies clear of the arcuate path of the sample container.  
  4. Equipment according to claim 3 wherein the pair of spaced arms and the sample collection chute are pivotally mounted on a base frame.  
  5. Equipment according to claim 4 wherein the pair of spaced arms are mounted on a shaft rotatably mounted on the base frame.  
  6. Equipment according to claim 5 wherein a driving wheel mounted on the shaft is adapted to impart rotary movement to the shaft and thereby pivotal movement to the pair of spaced arms.  
  7. Equipment according to claim 5 wherein a flexible transmission member engages the periphery of the driving wheel and at least one linear actuator is connected to the flexible transmission member and is adapted to move the flexible transmission member to impart rotary movement to the shaft.  
  8. Equipment according to claim 1 wherein the sample collection chute carries a cam surface and the dis charge door carries a cam follower whereby engagement of the cam follower with the cam surface opens the discharge door as the sample collection chute moves to the position in which it may collect a sample from the sample container.  
  9. Equipment according to claim 1 wherein a hydraulic linear actuator is arranged and adapted to move the sample collection chute.  
  10. Equipment according to claim 1 wherein the discharge door is hingedly connected to the sample container and the resilient means is a torsion spring.