US3102428A

US3102428A - Automatic sampling machine

Info

Publication number: US3102428A
Application number: US103283A
Authority: US
Inventors: William M Pyle
Original assignee: RHOANGLO MINE SERVICES Ltd
Current assignee: RHOANGLO MINE SERVICES Ltd
Priority date: 1960-04-21
Filing date: 1961-04-17
Publication date: 1963-09-03
Anticipated expiration: 1980-09-03
Also published as: DE1208917B; GB930410A

Description

Sept. 3, 1963 w. M. PYLE 3,

AUTOMATIC SAMPLING MACHINE Filed April 17, 1961 I 2 Sheets-Sheet 1 W/M/AM M Pl Lf P 3, 1963 w. M. PYLE 3,102,428

AUTOMATIC SAMPLING MACHINE Filed April 17, 1961 2 Sheets-Sheet 2 .box 16 and motor 17.

United States Patent Office 3 ,102,428 Patented Sept. 3, 1963 3,102,428 AUTOMATIC SAMPLING MACHINE William M. Pyle, Salisbury, Federation of Rhodesia and Nyasaland, assignor to Rhoanglo Mine Services Limited, Salisbury, Federation of Rhodesia and Nyasaland Filed Apr. 17, 1961, Ser. No. 103,283

Claims priority, application Federation of Rhodesia and Nyasaland Apr. 21, 1960 3 Claims. (Cl. 73-421) This invention relates to automatic sampling machines.

An object of the invention is to provide a machine that is adapted to provide a relatively accurate sample of a stream of comminuted ore or other granular or pulverulent material. Such a stream may, for example, be the stream at the discharge end of a conveyor belt.

A machine according to the invention comprises a primary scoop arranged to move in a path intersecting the stream and arranged to deposit its contents at a station remote from the stream, stream forming means arranged to receive the deposited contents and to form a secondary stream and a secondary scoop arranged to move in a path that intersects the secondary stream, the two scoops being so phased that the secondary scoop intersects the secondary stream after the secondary stream has been formed and for a portion of the time that the secondary stream flows. Usually the period of intersection of the secondary scoop will be a fraction of the duration of the secondary stream and phased to occur over a period including the midpoint of such duration.

Further according to the invention the machine comprises a primary scoop mounted for movement in a substantially circular orbit in a vertical plane which orbit is arranged to intersect the stream, means to move the scoop along the orbit, a receiving conveyor below a high level in the orbit of the scoop, means to cause the scoop to discharge its contents on to the receiving conveyor at such high level, the receiving conveyor being arranged to discharge material received by it in a secondary stream which preferably terminates in the primary stream, a secondary scoop mounted for movement in a substantially circular orbit in a vertical plane, which orbit is arranged to intersect the secondary stream, and means to move the secondary scoop along its orbit, the movement of the primary scoop and the secondary scoop and the rate of discharge of the receiving conveyor being so arranged that the secondary scoop intersects the secondary stream at the earliest after a full discharge from the receiving conveyor has commenced and the scoops being so mounted as to retain their charges at all positions along their orbits excepting for the discharge position of the primary scoop.

In the preferred form of the invention the two scoops are carried on a common rotary structure and so phased on the structure in the direction of rotation that the secondary scoop intersects the secondary stream after the primary scoop has discharged on the receiving conveyor.

An embodiment of the invention is described hereunder with reference to the accompanying drawings, in which FIGURE 1 is a side view of an automatic sampling machine according to the invention,

FIGURE 2 is a plan view of the machine, and

FIGURE 3 is a section along the line 3-3 of FIG URE 2.

In the figures a conveyor belt discharges material through chute 11.

The machine has a circular sampler scoop carrier 12 mounted on a horizontal shaft 13 which is in line with the longitudinal centre line of conveyor belt 10. The shaft 13 is driven by spur gear 14, through pinion 15, gear In order to accommodate conditions where intermittent operation of the machine is required a high speed shaft 18 between the motor 17 and gear box 16 is fitted with a magnetic clutch 19 and magnetic brakes 20 which are electrically interlocked. This arrangement allows the motor to run continuously and the clutch 19 and brake 20 are brought into their on positions by means of a time switch (not shown), which can be adjusted to give the frequency of sample cuts required. The clutch and brake are switched off by means of a trip switch (not shown) mounted on the drive unit bed plate and actuated by an arm (not shown) on the sample scoop carrier 12. This ensures that the sample scoops 21 and 22 come to rest in the same stationary position after each revolution during the intermittent operation.

The primary scoop 21 and the secondary scoop 22 are attached to the carrier plate 12 by means of horizontal swivel shafts 23 at their mouths to cause them to be in the vertical position at :all stations. The primary scoop 21 is an open-ended rectangular box with one side wall adjustable (not shown) to adjust the width (in the direction of movement) of the scoop. Its bottom is formed by an arc gate 24. The side walls 25 have negative slopes.

The secondary scoop 22 is formed as an elongated cylinder so that its charge presents a small surface area to the atmosphere to prevent excessive evaporation of moisture from the sample.

The primary scoop 21 is attached to the carrier plate 12 at a larger radius than the secondary scoop 22 and the two radii are so angularly displaced (see FIGURE 3) that the secondary scoop lags behind the primary scoop at the top of their orbits.

Directly above the conveyor belt 10" is a final sample feeder belt 26 running in the same direction as the conveyor belt 10. The feeder belt 26 is surmounted by a receiving hopper 27 which has formations 28 that are arranged to engage on the arc gate 24 of the primary scoop 21 to open it and cause the primary scoop to deposit its contents. The feeder belt 26 runs continuously and is driven by means of a motor 29.

The cycle of operations of the machine starts in that the primary scoop 21 passes through the falling stream of material issuing from chute 11, and collects a primary sample. This sample, as a percentage of the main feed, may be varied by changing the width of the primary scoop 21 or by changing the speed of rotation of the carrier plate 12.

The primary scoop 21 continues on its upward orbit and on engagement with the formations 28 of the receiving hopper 27, the arc gate 24 opens to deposit the primary sample in the hopper 27 and thence on to the feeder belt 26. The latter then commences to discharge a secondary stream of material. The primary scoop 21 passes over and the arc gate 24 closes under gravity.

Atfer the secondary stream has commenced the secondary scoop 22 passes through that stream to collect and retain the final sample. The size of the final sample may be varied by varying the opening of the secondary scoop 22 and also by varying the speed of rotation of the carrier plate 12. Of course, the latter variation affects both scoops.

In this cycle a sample is taken once per revolution of the carrier plate 12, but it will be understood that the clutch 19 and brake 20 will provide the taking of samples at lesser intervals.

The reject material from the secondary stream is arranged to rejoin the main stream and where the carrier plate 12 runs continuously the speeds of the feeder belt 26 and the carrier plate 12 are so arranged that the primary sample is completely discharged before the primary scoop 21 deposits a further primary sample.

The provision of a machine according to the invention may necessitate a rearrangement of the drive mechanism of the head pulley 29 of the conveyor belt 16.

I claim:

1. A machine for automatically sampling from a stream of granular or pulverulent material comprising a primary scoop adapted for movement in a substantially circular orbit in a vertical plane, the orbit intersecting the stream, and including means to move the scoop along the orbit, a receiving conveyor below a high level in the orbit of the scoop, means to cause the scoop to discharge its contents on to the receiving conveyor at such high level, the receiving conveyor being adapted to discharge material received by it in a secondary stream which terminates in the primary stream, a secondary scoop adapted for movement in substantially circular orbit in a vertical plane, which orbit intersects the secondary stream, and means to move the secondary scoop along its orbit, the movement of the primary scoop and the secondary scoop and the rate of discharge of the receiving conveyor being so arranged that the secondary scoop intersects the secondary stream at the earliest after a full discharge from the receiving conveyor has commenced, the scoops being swivelably mounted.

2. The machine of claim 1 in which the period of intersection of the secondary scoop is a fraction of the duration of the secondary stream and is phased to occur over a period including the mid-point of such duration.

3. The machine of claim 1 in which the two scoops are carried on a common rotary structure and phased on the structure in the direction of rotation that the secondary scoop intersects the secondary stream after the primary scoop has discharged on the receiving conveyor.

References Cited in the file of this patent UNITED STATES PATENTS 949,284 McCone Feb. 15, 1910 1,860,107 Lien May 24, 1932 2,534,656 Bond Dec. 19, 1950 FOREIGN PATENTS 588,766 Great Britain June 3, 1947