US3186503A

US3186503A - Weigh feeder system

Info

Publication number: US3186503A
Application number: US257389A
Authority: US
Inventors: James R Moore
Original assignee: Minerals and Chemicals Philipp Corp
Current assignee: Minerals and Chemicals Philipp Corp; Phibro Corp
Priority date: 1963-02-11
Filing date: 1963-02-11
Publication date: 1965-06-01
Anticipated expiration: 1982-06-01

Description

,318 Claims. (Cl. 17 5-422) The present invention relates to an improved method and apparatus for planting geophysical prospecting means at considerable depths in the earth, preferably near the base of a weathered layer thereof. More particularly, the invention is directed to an apparatus and method whereby a single operation forms a hole in the earth and deposits geophysical prospecting means therein.

The conventional method of planting geophysical pros pecting means, such as seismometers and explosive charges, consists of drilling a hole in the earth with a drilling tool, removing the drilling tool from the hole, and then lowering the prospecting means into the hole. A drawback to this method is that the planting of the prospecting means in the earth involves everal eparate and successive operations, namely, drilling a hole, removing the drilling apparatus from the hole, lowering the prospecting means into the hole, and removing the lowering apparatus if so desired.

Therefore, an object of the present invention is to decrease the number of operations necessary to plant geophysical prospecting means.

Another object of the invention is to decrease the time required to plant geophysical prospecting means, thereby lowering the cost of the operation.

A further object of this invention is to obviate the difiiculties that arise when prospecting mean are lowered into an open hole, such as guiding or forcing the prospecting means into the hole.

Still another object of the present invention is to disconnect geophysical prospecting means from planting apparatus when the prospecting means is in planted position. This is advantageous since the planting apparatus may be removed from the planted position and used to plant successive prospecting means. Furthermore, if the apparatus i used to plant explosive charges, removal is essential to prevent destruction of the apparatus upon detonation of the explosive charge.

The method of the present invention comprises, broadly, releasably securing geophysical prospecting means to a jet pipe, planting said pipe by guiding it toward and into the earth as fluid is forced through the pipe and jetted against the earth, releasing the prospecting means from the pipe at a desired depth and removing the jet pipe from the earth.

Basically, the apparatus of the present invention comprises a jet pipe adapted to flush its way into the earth, said pipe having a relatively large bore wherein prospecting means may be releasably secured without completely restricting flow through the pipe. When a jet pipe has flushed its way to a desired depth, the prospecting means may be released therefrom by inserting a plug into fluid being supplied to the pipe; which plug is adapted to transmit the fluid pressure to the prospecting means, thereby forcing it from the pipe.

T he invention will now be illustrated in greater detail with reference to the drawings, in which:

FIGURE 1 is a longitudinal section of a preferred embodiment of the invention.

FIGURE 2 is a cross-sectional view taken on line 22 I of FIGURE 1.

United States Patent 0 ice FIGURE 4 is a cross-sectional view on line 44 of FIGURE 3.

FIGURE 5 is a longitudinal section of an apparatus adapted to be used in combination with the apparatuses shown in FIGURES 1-4.

Referring to FIGURE 1, a seismometer 1th is coaxially arranged in the lower end of a pipe tring such a a jet pipe 11. The upper end of the jet pipe 11 is provided with a hose coupling (not shown) for supplying water or another suitable liquid to the jet pipe through a flexible hose. Peripheral teeth 12 are disposed around the lower end of the jet pipe 11. The seismometer 10 is centered relative to the jet pipe 11 by means of a number of ribs 13 running axially along the inner wall of the jet pipe so as to leave an annular space 14 between the seismometer and the inner wall of the jet pipe, which space forms a narrow slot 16 at the lower end of the jet pipe (see FIGURE 2).

One of the ribs 13 is provided with a longitudinal groove 17 through which a seism-ometer cable 18 is led to the outside of the pipe. A shear pin 19, adapted to be fitted in an opening in the jet pipe wall, prevents the seismometer 10 from dropping out of the jet pipe 11. Other detent members, such as spring clamps, may be used in place of the shear pin.

An inner pipe 21 is arranged in the jet pipe 11 above the seismometer 10. The pipe 21 is tightly disposed in the jet pipe 11 and is axially movable therein. The upper end of the inner pipe 21 is provided with a guide 22 for directing to the entrance thereof a ball 23 introduced upstream into the liquid supplied to the jet pipe, which entrance is designed as a seat 24 for said ball. The seat 24 is so designed that when the ball 23 rests thereon, the entrance to the inner pipe is closed.

A guide plate 26 extends through an axial slot 27 in the inner pipe 21 and is attached .by screws 28 to the jet pipe 11. The plate 26 has a rectangular upper part, which widens via a curved edge into a broad lower part. The wall of the jet pipe opposite the curved edge of the guide plate 26 has an opening 29 therein which is sufficiently large to allow the ball 23 to pass therethrough.

The inner pipe 21 rests on the top of the seismometer 10 through an intermediate pipe 31, the wall of which is provided with

recesses

32 and 33. The recess 33 extends to the lower end at the intermediate pipe 31 and provides a passage through which seismometer cable 13 is led to the outside of the jet pipe. Instead of using the intermediate pipe 31, the lower end of the inner pipe 21 can be designed in the form of the intermediate pipe so that the inner pipe 21 is then supported directly by the seismometer.

The above-described apparatus operates as follows: Water is supplied under pressure to the upper end of the jet pipe 11 (the ball 23 being not yet introduced therein) and flows downward successively through the inside of the jet pipe 11, the inner pipe 21, the intermediate pipe 31, the

recesses

32 and 33 of the intermediate pipe 31, the space between the intermediate pipe and the jet pipe, and finally leaves the apparatus 'at a high velocity throughsthe annular space 14 and the narrow slot 16.

When the apparatus is erected vertically above the ground, the efHuent water jet will erode the earth thereunder and form a hole therein. Theapparatus is then steadily lowered into the hole until the desired depth is reached. This depth is generally below the'weathered layer of the earth in order to avoid disturbing influences therefrom on the observation results. Upon passing through the relatively soft-weathered layer of the earth, downward movement of the apparatus is generally stopped. The point at which the apparatus passes through the weathered layer can be determined by the increased resistance afforded by the layers therebelow. After stopping downward movement of the apparatus the seismom- June 1, 1965 Y J. R. MOORE 3,186,503

WEIGH FEEDER SYSTEM Y Filed Feb. 11, 1963 s Sheets-Sheet 2 INVENTOR.

JAMES R. MOORE ATTORNEY June 1, 1965 J. R. MOORE 3,186,503

WEIGH FEEDER SYSTEM Filed Feb. 11, 1963 3 Sheets-Sheet 3 FIG. 6

INVENTOR.

JAMES R. MOORE ATTORNEY United States Patent 3,186,563 WElGH FEEDER SYSTEM James R. Moore, Strasburg, Va, assignor to Minerals & Chemicals Philipp Corporation, Menlo Park, N.J., a corporation of Maryland Filed Feb. 11, 1963, Ser. No. 257,38h 9 Claims. (Cl. 177-71) In many continuous industrial processes it is essential to discharge solid materialof varying particle size at a very uniform and predetermined weight rate of discharge. An example is in the operation of a vertical lime kiln which operates on a. continuous basis. The lime must i be continuously Withdrawn from a plurality of legs in the kiln and to achieve satisfactory operation of the kiln the weight rate of lime withdrawal from each of the legs must be very uniform and subject to control. Electrically operated feeders, such as vibrating feeders, g-ate feeders, belt conveyors and screw feeders can provide a fairly uniform and continuous Weight rate of discharge from outlets in kilns or other vessels. However, none of these feeders can, per se, insure the discharge of solids at the desired uniform and predictable weight rate. For example, with most of these feeders, changes in specific gravity of the material that is discharged alter the weight of material discharged in a unit time. With vibrating feeders, changes in the amplitudeof the supply current preclude the attainment of .a uniform and predictable weight rate of discharge. Priorart systems for smoothving out the operation of such feeders are very complex and expensive.

' Accordingly, an object of this invention is the provisionof a simple and inexpensive system for assuring the discharge of particulate solid material from an outlet provided with an electrically operated feeder at a uniform and predictable weight rate basis.

Another object is the provision of a system including a simple weigh beam element for controlling the electrical operation of a feeder which discharges material from a vessel.

Another object is the provision of such a system which can operate with feed of a rather wide variation of particle SIZB.

Further objects and advantages Will :be apparent from the description of the invention which follows taken with the accompanying drawings 'in which:

FIGURE 1 is a diagrammatic plan viewofthe weigh scale and associated electrical elementof the weigh feeder system of this invention;

FIGURE 2 is a diagrammatic side View of the system of FIGURE 1;

FIGURE 3 is a fragmentary rear View of the system of'F'IGURE l;

FIGURE 4 is a cross-sectional view of the loading bucket of the system of FIGURE 1;

FIGURE 5 is a fragmentary front view of the system of FIGURE 1; I,

FIGURE 6 is a diagram of the electrical operating circuit for a feeder together with the electrical circuit associated with the weigh scale system of FIGURE 1, as adapted to control the electrical energyinput into the circuit for the feeder.

Stated briefly, the weigh scale system of this invention, which is adapted to control the supply of electrical energy to a feeder which normally operates in response to electrical energy to discharge a continuous and relatively steady stream of particulate solid material from an opening in a vessel, comprises a beam type scale including a weigh beam, means for balancing the weigh beam for a preselected weight load and, supported on the weigh beam, a normally stationary load receiving element adapted for receiving and supporting solid material that is discharged by gravity from the feeder, the load receiving element being supported on the weigh t earn in a manner such that the contents thereof are dumped only when the scale tips. The scale is provided with switch means automatically responsive to the tipping movement of the scale for controlling the energy input into an electrical circuit which controls the operation of the feeder, especially by immediately breaking the electrical circuit when the weigh beam is tipped and by immediately closing the circuit when the weigh beam is in normal position, whereby solid material can flow from the outlet'in the vessel to the electrically operated feeder and then to the load receiving element onthe weigh beam only when the weigh beam is in equilibrium.

In operation, the weigh feed system of this invention provides for semi-continuous discharge of solid from an outlet in a vessel at a predetermined and steady weight rate. The weigh scale operates to interrupt the normal continuity of feed from the outlet by successive intervals of feed weighing. These intervals are controllable by a timer in the circuit. The weight rate of feed discharge is controlled by batches'of feed which are weighed by the scale which is controlled by the timer in the circuit. The effects of any variations in the feeder discharge rate are minimized since the weight of material required to trip the scale and cut off the flow of feed from the feeder is relatively unaffected by changes in feeder discharge rate.

It is also within the sope of this invention to include a counter in the circuit associated with the switch on the weigh scale to record each time the scale dumps. The use of the counter permits calculation of thetotal amount'of solids discharge from the vessel in a given period of time. Lights can be included in the circuit controlled by the weigh scale switch to indicate that the lo-ad receiving element is being loaded. Push button controls will normally be included in the'circuit to permit hand operation of the weigh scale.

This invention will be described in detail especially in connection with its adaptation to adjusting the operation of a vibrating feeder which feeds material from an outlet in a kiln. 1

Referring to FIGURES l to 5, the numeral 1 generally indicates a weigh scale. The scale, which is an evenarm, first-class lever,'includes parallel weigh beams, indicated by 2 and 2', joined at their butt end by a rigid cross member 3 and fulcrumed to pivot about beam bearings .4 and 4', respectively. The weigh scale 1 is supported overhead by

scale hangers

5 and 5 which maintain the scale assembly in fixed position. Removable weights 6 and 6' are passed through the stems of removable stemmed hangers 7 and 7' which are hung on cross member 3. A beam stop 8, located a short distance above the weigh beam 2 at the butt end, prevents the Weigh beam from tipping too far. Beam supports 9 and 9' are fastened on the bottoms of

brackets

10 and 1 1, respectively, which in turn are fastened to rigid cross member 12 of

support brackets

13 and 13.

A bucket, generally indicated by the numeral 14, is mounted at the load end of the weigh beam to pivot eccentrically about

bucket bearings

15 and 15. As shown.

Fatented June 1, 1965 inches.

in FIGURE 4, the bucket is divided lengthwise into congruent tapered

compartments

16 and 17, with the open top of compartment 16 being adjacent theclosed base of compartment 17 and the closed base of compartment .16 being adjacent the open top of compartment 17. 18 and center of gravity of the loaded compartment will be at a position whereby the bucket Will swing uniformly when loaded.

Protruding from a side of the bucket at a location near the open top of

compartments

16 and 17 are stop lugs 20 and 20', respectively, each being adapted to be engaged by'and retained, by an adjustable tapered stop 21 which is located adjacent a side of the bucket. Stop 21 is mounted on stop arm holder 22 which is secured to the scale hanger 5. Latch lugs 23 and 23' are provided adjacent the bottom of

compartments

16 and 1 7, respectively, for engaging a latch 24. secured to the upper surface of weigh beam 2. A microswitch 25' is mounted on bracket 16 and an adjustable switch operator 26" is mounted at't he end of weigh beam 2 and cross meme her 3.

i As shown in FIGURE 6, the microswitch has, one set of normally open contacts adapted to closev a circuit including a power supply, a starter coil 27 and a contact point 23 which is part of a triple contact system includ-' ing contact points 29 and 3% which are included in the feeder circuit to control feeder 31.

by movement of mercury in the switch in response to the movement of weigh beam 2; The circuit illustrated in FIGURE 6 also includes a control contact 33 adapted to supply line power to starter coil. 27 when the normally 'openset of contacts of microswitch 25 is closed. Also included in the circuit are push button controls (stop button 34 and start button 35), and indicator light 36'.

The circ'uit for the feeder includes a high voltage power:

supply, means for energizing feeder 31 (which is an induction coil in the case that the feeder is "a vibrating feeder) and two contact points, 29 and 3%, which .as mentioned are part of a triple contact system including contact 28 which is in series with starter coil 27 and the nor-; mally open setof contacts in microswitch 25.

In operating 'the weigh beam scale, weights 6 and 6', sufficient to give the required weight per dump, are placed on'the weight hangers 7 jand7'. started and maintained by automatic control, typically a pulse timer. When the timer closes contact 33 (momentary inthe case that a vibratory feeder'is used), starter coil 27 is. energized and closes contact 28. This closes the'other contacts 29 and 3b in the triple contact systems, therebyclosing the circuit supplying power to feeder 31 which thenoperates and causes lime to flow from theleg of the kiln. to the feeder. Aii Of the lime fed from the leg of the kiln to feeder 31 is immediately gravity fed;

into the open end of compartment 16 of weigh bucket 14.

This feed may vary during operation in size from lumps;

as small as about one inch to lumps as large as about four When the weight of solid inicompartment, 16 equals the weight placed on theholders, the weigh beams 2 and 2 will'rotate on beambearings 4 and 4' and tip.

The rotation of the beam will cause stop lug26 on compartment 16 to slip below stop 21. When bucket 14 is T he other set of contacts in microswitch 25, which is in a normally closed The Weigh cycle is.

the bucket rapidiydump out of the bucket as the bucket rotates. Afterthe bucket dumps. and has traveled about weigh beams 2 and 2' begin to return to their normal horizontal position carryingbucket 14 with them. As stop .lug 29 on compartment lo of bucket 1% approachesadjustable stop 21'for engaging the stop, latch lug 23 near thebase of compartment 17fgoes past and engages latch 24 ,onrweigh beam 2, thereby preventing bucket 14 from rebounding 'ofi stop 21 and'spinning back out of position. Compartment of the bucket, which was inverted in the previous weighing, is now ready to 'revceive solid discharged frorn'the feeder when contact 33 is 7 closed by the pulse timer automatically set at apredeten mined timed cycle.

If desired, a single compartment bucket can be used. In this case the bucket is designedto rotate through 360 with each weighing.

- v When the Weigh beam trips, the normally open contact of microswitch 25 ,is in open position; allowing starter coil 27 to de-energizeand open the triplecontact system comprising contacts. 28,23 andfiti, therebyj shutting off the supply of high voltage to feeder 31. The feeder then stops feeding from the leg ojfthe kiln; Simultaneously the normally closed set of contacts in microswitch 25is.

closed, bringing the counter 32 into the circuitto'indicatc a dump. The indicator light 36 is on whilethe. bucket is w being loaded. Push button controls 34 and 35' can beused to operate the weighscale manually. I

To control simultaneously discharge from 'afkiln having a plurality of discharge outlets,.ea c h outlet is'supplied with a feeder, weigh scale, microswitch and associated circuit as described above.

Iclaim: I

1. A weigh scale system for continuously controlling the weight rate of flow'of particulate solid material from an electrical circuit including means for supplying elec-' trical energyto said feeder, and timer means for auto matically controlling the, electrical'energy input into said feeder in accordance. with apredetermined timed cycle, a V e a weigh scale comprising a weight beam, means for balancing said Weigh beam for a p'reselected weight load andva load receiving element supported on said weigh beam for receiving particulate solid material passing from the outlet inthe' vessel to the feeder, said load receiving element being rotatably supported on said weigh beam ina manner such that said load receiving element can rotate and dump its loadonly when the weight of the-load therein balances the preselected weight, g 1 g and switch means associated with and responsive to I the tippingmovement ofsaid weigh beam for controlling the supply of energy to. the-feeder that controls the discharge of material from the outlet to the vessel, whereby the weight, of particulate material 7 discharged through the outlet in the .vessel is con- 1 trolled. by the movement of the weigh beam.

2:. A weigh scale system foricontinuously' controlling the weight rate-of'flew ofparticulate solid material1 from 1 'a vessel having an outlet, said system comprising:

- a'continuous feeder for controlling the flow of material.

from an outlet in a vessel iwhich allows materialto flow from saidi'outlet onlywhen electrical energy is supplied thereto,

an electrical circuit including means for supplying e1ec V a weigh scale comprising a weigh beam, means for balancing said weigh beam for a preselected weight load and a load receiving element supported on said Weight beam for receiving particulate solid material passing from the outlet in the vessel to the feeder, said load receiving element being rotatably supported on said weigh beam in a manner such that said load receiving element can rotate and dump its load only when the weight of the load balances the preselected weight,

and a switch containing a contact which can be opened and closed associated with said weigh beam and motivated thereby in a manner such that said contact opens when the weigh beam tips and is closed when the weigh beam is being balanced, and means connecting said switch to the electrical circuit supplying electrical energy to the feeder, whereby the feeder is energized and the feeder can discharge material from the vessel only when the weigh beam is being balanced and said contact on said switch is closed.

3. The system of claim 2 in which said load receiving element on said weigh beam is associated with lock means for preventing said load receiving element from rotating when the weigh beam is being balanced and which is automatically released when the weigh beam tips'and is automatically engaged after the load receiving element rotates and the beam rises.

4. The system of claim 1 in which said load receiving element is'a bucket containing adjacent compartments, an open top of the first compartment being adjacent a closed bottom of the other compartment and a closed bottom of the first compartment being adjacent the open top of the other compartment, and said bucket is mounted for rotation in a manner such that it rotates through an angle of 180 when its load balances the preselected weight, whereby the'compartments in said bucket are alternately in position for receiving a load of particulate material.

5. The system of claim 2 in which said weigh scale is in the form of an even-arm, first-class lever.

6. A system for discharging particulate solid material at a predetermined and steady weight rate from a vessel having an outlet, said system comprising:

a continuous feeder for controlling the flow of material from an outlet in a vessel and which feeds mate- I rial only when electrical energy is supplied to the feeder,

an electrical circuit including means for supplying electrical energy to the feeder and timer means for automatically controlling the electrical energy input into said feeder in accordance with a predetermined timed cycle,

a weigh scale in the form of an even-arm, first-class lever and comprising a weigh beam, means for balancing said weigh beam for a preselected weight load and a bucket adapted to be loaded with particulate solid from the feeder,

said bucket being mounted for rotation about said weigh beam in a manner such as to discharge its load and through an angle such that after rotation it is in a position to be loaded, said bucket being provided with lock means for preventing the bucket from rotating while the beam is being balanced and which is automatically disengaged when the beam tips and is automatically engaged when the beam returns to balancing position, whereby the bucket rotates and discharges its load only after the load balances the preselected weight,

and a switch containing a contact which can be opened and closed associated with said weigh beam and motivated thereby in a manner such that said contact is open when the weigh beam tips and is closed when the weigh beam is being balanced, and means connecting said switch to the electrical circuit supplying electrical energy to the feeder, whereby the feeder is energized and material is discharged from the vessel only when the weigh beam is being balanced and said contact on said switch is closed.

7. The system of claim 6 in which said lock means comprises a lug on a side of the bucket adjacent the top of the bucket and stop means for engaging said lug when said lug rotates against said stop in a manner such that the lug is released when the lug moves downward from the stop means.

8. The system of claim 7 in which said bucket is provided with means for preventing the bucket from rotating in the opposite direction when said bucket rotates and the lug hits the stop.

9. A weigh feed system for controlling the weight rate of flow of particulate solid material from a vessel having an outlet, said system comprising:

a vibrating feeder adapted to feed material from an outlet in a vessel which feeds material when electrical energy is supplied to said feeder,

an electrical circuit for supplying energy to said vibrating feeder including timer means for automatically controlling the electrical energy input into said feeder in accordance with a predetermined timed cycle and a contact which can be opened and closed,

a second electrical circuit including a microswitch having a contact which can be opened and closed, a

coil and contact means adapted to close the contact in said first-mentioned electrical circuit when said contact in said microswitch is closed and said coil is energized and open the contact in said first-mentioned circuit when said contact in said microswitch is opened and said coil is de-energized,

and weigh scale means associated with said microswitch for automatically controlling the opening and closing of said contact in said microswitch in a manner such as to automatically open the contact in the first-mentioned circuit and stop flow of material from the outlet in the vessel when a preselected weight of particulate solid has been discharged from said outlet to said feeder, said weigh scale means being in the form of an even-arm, first-class lever and comprising a Weigh beam, the tipping of which opens the normally open contact of said microswitch, means for balancing said weigh beam for a preselected weight load and a bucket supported on said beam for receiving a load of particulate solid material that has been discharged from said outlet to said feeder,

said bucket being mounted for rotation about said weigh beam in a manner such as to discharge its load when rotated and through an angle such that after rotation it is in a position to be loaded, said bucket being provided with latch means for preventing the bucket from rotating while the beam is being balanced and which is automatically disengaged when the beam tips and is automatically re-engaged when the beam returns to balancing position, whereby the weigh beam tips when the load in the bucket load balances the preselected weight load, thereby causing said contact in said microswitch to open and to stop the flow of material from the outlet in said vessel.

References Cited by the Examiner UNITEDSTATES PATENTS 471,034 3/92 Sprague 177-83 876,603 1/08 Staude 177-83 X 1,188,215 6/16 Staaf 177-83 2,833,506 5/58 Gunderson H-. --120 LEO SMILOW, Primary Examiner.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent No. 3,186,503 June 1, 1965 James R, Moore It is hereby certified that error appears in the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Coumn 5 line 28, for the claim reference numeral "1" read 2 t Signed and sealed this 2nd day of November 1965 (SEAL) Allest:

ERNEST W. SWIDER Attesting Officer EDWARD J. BRENNER Commissioner of Patents

Claims

1. A WEIGH SCALE SYSTEM FOR CONTINUOUSLY CONTROLLING THE WEIGHT RATE OF FLOW OF PARTICULATE SOLID MATERIAL FROM A VESSEL HAVING AN OUTLET, SAID SYSTEM COMPRISING: A CONTINUOUS FEEDER WHICH OPERATES IN RESPONSE TO ELECTRICAL ENERGY TO DISCHARGE MATERIAL FROM AN OUTLET IN A VESSEL WHICH FEEDS MATERIAL WHEN ELECTRICAL ENERGY IS SUPPLIED TO SAID FEEDER, AN ELECTRICAL CIRCUIT INCLUDING MEANS FOR SUPPLYING ELECTRICAL ENERGY TO SAID FEEDER, AND TIMER MEANS FOR AUTOMATICALLY CONTROLLING THE ELECTRICAL ENERGY INPUT INTO SAID FEEDER IN ACCORDANCE WITH A PREDETERMINED TIMED CYCLE, A WEIGH SCALE COMPRISING A WEIGHT BEAM, MEANS FOR BALANCING SAID WEIGH BEAM FOR A PRESELECTED WEIGHT LOAD AND A LOAD RECEIVING ELEMENT SUPPORTED ON SAID WEIGH BEAM FOR RECEIVING PARTICULATE SOLID MATERIAL PASSING FROM THE OUTLET IN THE VESSEL TO THE FEEDER, SAID LOAD RECEIVING ELEMENT BEING ROTATABLY SUPPORTED ON SAID WEIGH BEAM IN A MANNER SUCH THAT SAID LOAD RECEIVING ELEMENT CAN ROTATE AND DUMP ITS LOAD ONLY WHEN THE WEIGHT OF THE LOAD THEREIN BALANCES THE PRESELECTED WEIGHT, AND SWITCH MEANS ASSOCIATED WITH AND RESPONSIVE TO THE TIPPING MOVEMENT OF SAID WEIGH BEAM FOR CONTROLLING THE SUPPLY OF ENERGY TO THE FEEDER THAT CONTROLS THE DISCHARGE OF MATERIAL FROM THE OUTLET TO THE VESSEL, WHEREBY THE WEIGHT OF PARTICULATE MATERIAL DISCHARGED THROUGH THE OUTLET IN THE VESSEL IS CONTROLLED BY THE MOVEMENT OF THE WEIGH BEAM.