US2962172A - Material handling control system - Google Patents

Description

Nov. 29, 1960 Filed March 10, 1958 D. W. FATH ET AL MATERIAL HANDLING CONTROL SYSTEM NUT COKE BIN 2 Sheets-Sheet 1 Nov. 29, 1960 D. W. FATH ETAL MATERIAL HANDLING CONTROL SYSTEM Filed March 10, 1958 2 Sheets-Sheet 2 O MANUAL z OPEN WIL COK E ELECTFZODE -q@ CLOSED AM coke ml.

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MATERIAL HANDLING "CONTROL SYSTEM Douglas W. Fa'th, Brookfield, and Charles E. Smith, Milwaukee, Wis, assignorsto Cutler-Hammer, Inc., Milwaukee, Wis, a corporation of Delaware Filed Mar. 10, 1968, Ser. No. 720,399

20 Claims. (Cl. 1214-417 This invention relates to material handling control systems and more particularly to electrical systems for controlling filling and discharging of material such as coke and the like.

While not limited thereto, the inventionis especially applicable to charging control systems for blast furnaces and the like.

In the processing of ore in a blast furnace, it is the usual practice to employ a skip hoist mechanism for charging the furnace. The usual skip hoist mechanism of this type comprises a pair of inclined tracks extending between a skip charging pit at the base of the furnace and a distributor hopper at the top of the furnace, and a pair of skip cars traveling on these tracks for conveying charging material from the pit and dumping the same into the distributor hopper. The skip cars are connected together through their operating mechanisms in counterbalancing relation and arranged so that when one skip car is traveling upwardly along its track toward the top of the furnace the other skip car is traveling downwardly along its track toward the charging pit. Each time the left skip car enters the charging pit, the right skip car enters its dump position at the top of the furnace and vice versa. At such times, the skip hoist is stopped for a predetermined time interval to permit dumping of a skip load into the distributor hopper and to permit filling of the other skip car from a weigh hopper over the charging pit. The skip hoist is then restarted in the reverse direction to hoist another load.

The Weigh hoppers located over the charging pit are provided with discharge gates selectively operable for discharging predetermined quantities of charging material such as coke into the left and right skip cars when the latter enter the charging pit.

Furnace coke is screened before being discharged into the left and right weigh hoppers. Each furnace coke storage bin is provided with a discharge chute having a restricted opening normally bridged by the coke and a vibrating mechanism effective when operating for feeding coke from the bin onto a traveling conveyor belt. The conveyor belt carries the coke onto a motor-operated screen whereby the fine dust or breeze is removed onto a breeze conveyor and thus carried away, the larger, desirable particles of coke being discharged from the screen into the weigh hopper.

When the left and right weigh hoppers are filled with nut coke, screening is not required, and the coke is drawn directly from the nut coke storage bin into the weigh hopper.

A general object of the invention is to provide an improved material handling control system whereby to reduce the operating time and to increase the capacity of material handling apparatus.

A more specific object of the invention is to provide such control system with improved means coordinated with a blast furnace charging controller for controlling loading of predetermined, measured quantities of charging material such as coke and the like into skip cars.

2,962,172 Patented Nov. 29, 1960 Another specific object of the invention is to provide selective automatic and manual coke control systems for filling hoppers with selected charging materials and for discharging the same into the skip cars when the latter enter the charging pit.

Another specific object of the invention is to provide such control system with improved means for presetting the control system for automatic operation or manual operation or for transferring selected portions of the control system for manual operation while other portions thereof are preset for automatic operation, as desired.

Another specific object of the invention is to provide improved presettable control means for automatically measuring a predetermined quantity of charging material discharged into the hoppers either by Weight or by volume.

Another specific object of the invention is to provide safety means whereby such volume control means is rendered effective in the event of failure of such weight control means.

Another object of the invention is to provide a pair of improved material loading control systems for alternately controlling discharge of material loads into respectively associated conveyor receptacles combined with means for obtaining each load under the control of one of the control systems when the other control system is turned off.

Other objects and advantages of the invention will hereinafter appear.

While the apparatus hereinafter described is effectively adapted to fulfill the object stated, it is to be understood that we do not intend to confine our invention to the particular preferred embodiment of control system disclosed, inasmuch as it is susceptible of various modifications without departing from the scope of the appended claims. a

In the drawings which diagrammatically depict a material handling control system constructed in accordance with the present invention, Figure 1 schematically shows the general arrangement of the material handling apparatus; and p Fig. 2 diagrammatically shows a circuit for controlling the apparatus of Fig. 1.

In the circuit diagram, the relays have been given reference characters indicative of the functions thereof, and the numeral within the operating coil indicates the total number of contacts for the corresponding device. For example, in the upper right-hand portion of Fig. 2 of the drawings, a left coke starting relay has an operating coil identified as LCSR (hereinafter referred to as relay LCSR) and three contacts characterized as LCSRl, LCSRZ and LCSR3. 7

Referring to Figure 1, there is shown a coke handling apparatus whereby furnace coke or nut coke is selectively drawn from storage bins in measured amounts and discharged into a skip car. Fig. 1 schematically shows the apparatus for loading the left skip car. The apparatus for loading the right skip car is similar thereto and has been omitted to avoid complicating the drawing.

As shown in Figure 1, there are provided three fumace coke storage bins No. 1, No. 2 and No. 3 each having a restricted opening 4 at the lower portion thereof. Vibrators V1, V2 and V3 are located below the restricted openings 4 of the respective furnace coke storage bins. Vibrators V1, V2 and V3 are actuated by magnets M1, M2 and M3, respectively, as hereinafter described. A coke conveyor 6 of the belt type is positioned below the vibrators for carrying the coke which is drawn from the bins onto a vibrating screen 8, and contacts LCB-M shown adjacent conveyor 6 are provided for controlling the circuit of Fig. 2. A weigh hopper 10 is provided for receiving the screened cok Weigh hopper 10 is provided with a pair of electrodes E1 and E2 also shown in:

Fig. 2 and a zero weight scale contact ZWSC and a full weight scale contact FWSC for operation thereby. Zero weight scale contact ZWSC is normally closed and full weight scale contact FWSC is normally open when the weigh hopper is empty. Weigh hopper is also provided with a discharge gate 12 shown in its closed condition. Discharge gate 12 is arranged for operation by an air cylinder 14 connected through a pair of conduits to an air valve 16, the latter being operable by a left discharge gate solenoid LDGS, as hereinafter described. There are also provided three discharge gate limit switches DGLSI, DGLS2 and DGLS3 arranged for operation by air cylinder 14., Limit switches DGLSI and DGLS3 are normally closed and limit switch DGLS2 is normally open when gate 12 is closed. Skip car-18 is arranged for travel on a track 20 and arranged for stopping in a skip pit 22 to receive the coke discharged from weigh hopper 10. Nut coke storage bin 24 is positioned above the weigh hopper. Nut coke storage bin 24 is provided with a fill gate 26 arranged for operation by an air cylinder 28.

Air cylinder 28 is connected through a pair of conduits to an air valve 30 and the latter is arranged for operation by a left fill gate solenoid LFGS also shown in Figure 2.

Contacts LCS-M shown adjacent coke screen 8 are provided for controlling the system shown in Fig. 2. There is also provided a breeze conveyor 32 of the belt type positioned below coke screen 8 for conveying away the fine particles of coke, and contacts LBC-M shown adjacent screen 8 for controlling the system of Fig. 2. Contacts LCS-M and LBC-M are normally open and are closed where the coke screen and breeze conveyor motors are started. Skip car 18 is provided with a controller including contacts HL1, HL2 and HL3 which are normally open and are closed when the skip car is hoisted from the pit. Left skip-in-pit relay contacts LSP shown adjacent skip car 18 are normally open as shown in Fig. 2 and are closed when the left skip car enters the charging pit as shown in Fig. 1.

Referring to Fig. 2 of the drawing, there is shown a left coke control system connected to power supply lines L1 and L2 for controlling filling of left weigh hopper 10 and for discharging the coke therefrom into the left skip car 18. Another coke control system similar to that shown would ordinarily be provided for controlling filling of the right weigh hopper and for discharging the coke therefrom into the right skip car.

The control system shown in Fig. 2 comprises (1) a fill control network and (2) a discharge control network.

The fill control network is shown primarily in the lefthand and upper portions of the drawing, and the discharge control network is shown primarily in the mid-portion of the drawing, the extreme lower left-hand portion of the drawing showing certain control elements of both the fill and discharge control networks.

The fill control network is provided with control devices operable either automatically in response to the aforementioned charging control system or manually,

'as selected, for filling the weigh hopper with a predetermined quantity of so-called furnace coke or nut coke regardless of the preselected mode of operation of the discharge control network. When the fill control network is preset for automatic operation, additional control devices are rendered operable to preselect either furnace coke or nut coke and to preselect measurement thereof in the weigh hopper either by weight or by volume. When the fill control network is preset for manual operation, the aforementioned control devices are rendered operable to preselect either furnace coke or not coke but the automatic measuring control devices are rendered ineffective so that the filling operation is entirely under manual control. 1

The discharge control network is provided with control devices operable either automatically in response to the charging control system or manually, as selected, for discharging the coke from the weigh hopper into the skip car regardless of the preselected mode of operation of the fill control network. Whether preset for automatic or manual operation, the discharge control network is provided with interlocking control devices to prevent discharge of the coke from the weigh hopper until a skip car enters the charging pit and to prevent automatic starting of the skip hoist until the discharge control operating cycle has been completed.

The fill control network portion of the coke control system is provided with a fill selector switch F8 for presetting the weigh hopper fill control apparatus for automatic or manual control and for turning the fill control apparatus off, a weight-volume selector switch WV for preselecting automatic measurement of the coke in weigh hopper 10 either by weight or by volume, a manual fill switch MP for manually controlling filling of the weigh hopper when the fill selector switch is preset in its manual operating position, and a furnace-nut coke selector switchFN forpreselecting the rye of coke with which the weigh hopper is to be filled. h

The fill control network is furtherprovided with a plurality of relays including a left. coke starting relay LCSR of the. latched type for initiating the weigh hopper filling operation, a left screen control relayLSCR for starting the left coke screen. motor, a left screen acceleration timing relayLSAT for delaying operation of the coke belt feeder motor to afford the screen motor time to accelerate, a left belt acceleration timing relay LBAT for delaying operation, of vibrating mechanisms V1, V2 and V3 to afford the coke belt feeder motor time to accelerate, and a left vibrator start relay LVR for initiating operation of magnets M1, M2 and M3 of preselected vibrating feeders. For a disclosure of. program control apparatus for preselecting the vibrating feeders and thereby the bin or combination of bins from which furnace coke is drawn to fill the weigh hopper, reference may be had to Douglas W. Path and Charles E. Smith copending application Serial No. 721,717, filed March 17, 1958.

There is also provided a left nut coke gate relay LNG for operating nut coke bin gate 26. and in circuit therewith a normally closed jog-close switch JC for clearing a jam of coke at the nut coke bin gate. A left full weight relay LFWR and in circuit therewith the aforementioned normally open full weight scale contact FWSC are provided for detecting completion of filling of the weigh hopper when the coke is measured by weight. A left full volume detector relay LFV is provided for detecting completion of filling of the weigh hopper when the coke is measured by volume. To this end, relay LFV isprovided with a two branch core C having .a first winding W1 wound on one branch and connected across power supply lines L1 and L2 and a second winding W2 wound on the other branch and connected at its ends to a pair of spaced electrodes E1 and E2, the latter being arranged to be bridged by the coke when the weigh hopper is'filled to full volume as shown in Fig. 1, thereby to short'circuit winding W2. Relay LFV is also provided with an armature A operable to close its contacts LVFl 'as'hereinafter described. A left full volume relay LFVR is provided for stopping filling of weigh hopper 10 when a full volume is detected. The fill control network is also provided with the aforementioned left fill gate solenoid LFGS for controlling operation of nut coke bin gate 26.

The discharge control network portion of the coke control system is provided with a discharge selector switch DS for presetting the weigh hopper discharge control an paratus for automatic or manual control and for turning the discharge control apparatus off, and a manual discharge switch MD for manually controlling discharge of the material from the weigh hopper into skip car 18 when the discharge selector switch is preset in its manual operating position.

The' control system is further provided with a left coke system switch LCS for turning the control system on and oil. The aforementioned'switches may be of the manually operable type or the like. The control system is also provided with a left coke system off relay LOR forinterlocki'ng the coke control apparatus with the charging control system as hereinafter described.

Aleft zero weight relay LZWR and in circuit therewith the aforementioned normally closed zero weight scale contact ZWSC are provided in the discharge control network for detecting discharge of coke from the weigh hopper. A normally open zero weight switch ZW of the manual pushbutton type or the like is provided in shunt of the zero weight scale contact to insure operation of relay LZWR. A left discharge hopper gate relay LHR is provided for controlling the aforementioned left discharge gate solenoid LDGS thereby to discharge coke in the skip car as hereinafter described. A left discharge hopper gate timing relay LDT is provided for timing the open interval of the weigh hopper gate. Relays LZWR and LHR also interlock with the skip hoist control as hereinafter described.

Suitable visual indicator lamps 1L1 and IL2 are provided for indicating application of power to the coke control system and for indicating the open condition of the nut coke bin gate, respectively. Indicator lamps 1L3 and IL4 are provided for indicating the open and closed conditions of weigh hopper discharge gate 12-. There are also provided the aforementioned weigh hopper discharge gate limit switches shown in Fig. 1. Interlocking limit switch DGLSl prevents operation of the fill control apparatus until the weigh hopper discharge gate is closed and is normally tripped to its closed condition when the discharge gate is closed. Limit switch DGLSZ is normally reset to its open condition to extinguish lamp IL-3 when the discharge gate is closed and limit switch DGLS3 is normally tripped to its closed condition to energize lamp 1L4 when the discharge gate is closed.

The operation of the coke control system will now be described.

Let it be assumed that suitable alternating current power is connected to supply lines L1 and L2, thus to energize coke system power on indicator lamp 1L1.

Automatic filling To preset the control system for automatically filling the weigh hopper with either furnace coke or nut coke, fill selector switch FS is left in its Auto designating operating position as shown. The left coke system selector switch LCS is turned to its On operating position. Assuming that discharge selector switch DS is in either its Auto or Manual designating operating position, relay LOR is energized in a circuit extending from line L1 through fill selector switch contact PS3, switch LCS, discharge selector switch contacts DSl and the operating coil of relay LOR to line L2. Relay LOR opens contacts LORI and LOR3 and closes contacts LORZ and LOR4 for reasons hereinafter described. Assuming that weigh hopper is empty and its discharge gate 12 is closed, zero weight scale contact ZWSC and discharge gate limit switches DGLSl and DGLS3 are closed. Limit switch DGLSI partially completes an energizing circuit for closing coil C of relay LCSR. Limit switch DGLS3 energizes lamp 1L4 to indicate that the discharge gate is closed. Scale contact ZWSC completes an energizing circuit for zero weight relay LZWR in a circuit extending through contacts ZWSC, LNG3, LSCRZ, LFWR3 and LFVR3, and the operating coil of relay LZWR. The latter energizes and closes contacts LZWRl in the skip hoist control circuit for reasons hereinafter described, closes contacts LZWR2 to complete another point in the energizing circuit of closing coil C of relay LCSR, closes contacts LZWRS to complete a holding circuit for its operating coil in shunt of scale contact ZWSC, and closes contacts LZWR4 to partially complete an energizing circuit for timing relay LDT.

B Furnace coke by weight Assuming that weigh hopper 10 is to be filled auto matically with furnace coke by weight, selector switch FN is left in its Furnace designating operating position and selector switch WV is left in its Weight designating operating position, as shown. The aforementioned breeze conveyors 32 are started in a manner well-known in the art and, as a result, contacts LBC-M shown in Figs. 1 and 2 are closed, the latter being operable by a left breeze conveyor motor main contactor or the like (not shown).

When the skip hoist is energized to hoist left skip car 18 from charging pit 22, hoist left relay contacts HLl, HL2 and HL3 close. For a disclosure of the skip hoist operating control circuits, reference may be had to Douglas W. Path and Charles E. Smith copending application Serial No. 720,400 filed March 10, 1958. As a result of closure fo contacts HLl, the closing coil C of left coke starting relay LCSR energizes in a circuit extending through fill selector switch contacts FSI, contacts I-ILl, LZWRZ, LFWRl and LFVRI, limit switch DGLSl and contacts LCSR3. Relay LCSR is latched in its closed position and closes contacts LCSRl to partially complete an energizing circuit for its tripping coil T, closes contacts LCSRZ to energize relay LSCR, and opens timed opening contacts LCSR3 to deenergize closing coil C after a predetermined time interval. The energizing circuit of relay LSCR may be traced through fill selector switch contact PS3, switch LCS, contacts LCSR2, switch FN, contacts LBC-M and the operating coil of relay LSCR. Relay LSCR being thus energized, closes contacts LSCRl to energize the coke screen motor main contactor (not shown) thereby to start the coke screen motor. Relay LSCR also opens'contacts LSCR2 to interrupt energization of zero weight relay LZWR, and opens contacts LSCR3 to prevent opening of weigh hopper discharge gate 12.

As a result of energization of the left coke screen main contactor, contacts LCSM shown in Figs. 1 and 2 complete an energizing circuit for relay LSAT. After a predetermined time interval for acceleration of the left coke screen motor, timed closing contacts LSATl complete an energizing circuit for the coke belt motor main contactor (not shown) thereby to start the cokeconveyor belt motor and to close contacts LCB-M. The latter complete an energizing circuit for relay LBAT. After another time interval for acceleration of the left belt motor, timed closing contacts LBATl complete an energizing circuit for left vibrator start relay LVR. The latter closes contacts LVRl to apply power to the furnace coke bin chute vibrators V1, V2 and V3 that have been preselected by the aforementioned coke bin program control.

As a result, furnace coke flows from the preselected storage bins onto coke feeder belt 6 wherebyit is conveyed to coke screen 8. The screen removes the fine coke dust to be carried away by breeze conveyor 32 and the remaining screened coke particles are discharged into weigh hopper 10. When a predetermined full weight of coke has been accumulated in weigh hopper 10, full weight scale contact-FWSC closes to complete an energizing circuit for left full weight relay LFWR in a cricuit extending through fill selector switch contact PS4, scale contact FWSC and the operating coil of relay LFWR. As a result, contacts LFWRI open to prevent energization of closing coil C and contacts LFWR2 complete an energizing circuit for tripping coil T of relay LCSR, the lat-. ter circuit extending through fill selector switch contact F51, switch WV, contacts LFWRZ and LCSRl and trip: ping coil T. Relay LFWR also opens contacts LFWR3 to further interrupt the energizing circuit of relay LZWR, and closes contacts LFWR4 to partially complete an energizing circuit for left coke hopper discharge gate relay LHR to prepare the discharge control network for operation.

Relay LCSR thus being tripped back to its normal position shown, opens contacts LCSR2 to interrupt energization of relays LSCR, LSAT, LBAT and LVR thereby to stop coke screen 8, coke feeder belt 6 and'coke vibrators V1, V2 and V3. The breeze conveyor 32, however, continues to run until manually stopped. Relay LCSR also closes contacts LCSR3 and after a time interval opens contacts LCSRl to deenergize its tripping coil T; the relay, however, being latched in its tripped position as shown.

The left weigh hopper is thus filled with furnace coke by weight and the control system is ready to discharge the same into left skip car 18 when a signal is received indicating that the left skip car has re'entered the charging pit as hereinafter described.

Furnace coke by volume Assuming that the weigh hopper is to be filled automatically with furnace coke by volume, selector switch FN is left in its Furnace designating operating position as before, and selector switch WV is turned to .its Volume designating operating opsition. Let it be assumed that the breeze conveyor 32 is running and, therefore, contacts LBC-M are closed.

When the skip hoist is energized to hoist the left skip car from the charging pit, hoist left relay contacts HLl close to initiate the filling operation as hereinbefore described. The sequence of operations for filling the weigh hopper by volume is the same as hereinbefore described for filling the weigh hopper by weight, except that contacts LFWR2 of left full weight relay LFWR are not effective to trip relay LCSR to its normal position to stop the filling operation. Instead, furnace coke flows into weigh hopper 10 until it bridges coke electrodes E1 and E2. As a result, the coke short-circuits winding W2 of left full volume detector relay LFV, and winding W1 of relay LFV being connected across lines L1 and L2, relay LFV actuates armature A thereby closing contacts LFVL Closure of contacts LFVI effects energization of left full volume relay LFVR in a circuit extending through fill selector switch contact PS4, contacts LFV1 and the operating coil of relay LFVR. Contacts LFVRI interrupt a point in the energizing circuit of closing coil C of relay LCSR, the latter having been deenergized by opening of its contacts LCSR3 a predetermined time interval after energization thereof as hereinbefore described. Relay LFVR also closes contacts LFVR2 to complete an energizing circuit for tripping coil T of relay LCSR in a circuit extending through fill selector switch contact PS1, contacts LFVRZ and LCSRl, and tripping coil T to trip relay LCSR back to its normal position shown. Relay LFVR in addition opens contacts LFVR3 to prevent energization of zero weight relay LZWR, and closes contacts LFVR4 to partially complete an energizing circuit for Weigh hopper discharge gate relay LHR.

Tripping of relay LCSR back to its normal position effects stopping of the filling operations as hereinbefore described.

Full volume relay LFVR is arranged to provide a safety feature effective when filling by weight to always stop the filling operation even if full weight scale contact FWSC fails to function. Thus, when filling by weight, if scale contact FWSC fails to energize relay LFWR and thereby trip relay LCSR to stop the filling operation, relay LCSR is always tripped by full volume relay LFVR when the coke bridges electrodes E1 and E2 to prevent an overflow from weigh hopper 10. To this end, relay LFVR is provided with the aforementioned contacts LFVR2 connected in shunt of both selector switch WV and full weight relay contacts LFWR2.

Nut cake by weight or by volume Assuming that weigh hopper 10 is to be filled automatically with nut coke, selector switch FN is turned to its Nut designating operating position. As nut coke is not screened but rather is drawn directly from nut coke storage bin 24 into weigh hopper 10, operation of breeze conveyor 32, vibrating mechanisms V1, V2 and V3, coke screen 8 and coke feeder belt 6 is not required.

When the skip hoist is energized to hoist left skip car 18 from the charging pit, hoist left relay contacts HLl complete an energizing circuit for closing coil C of relay LCSR as hereinbefore described. Contacts LCSRI close to partially complete an energizing circuit for tripping coil T of relay LCSR, and contacts LCSR2 complete an energizing circuit for nut coke bin gate relay LNG in a circuit extending through fill selector switch contact PS3, switch LCS, contacts LCSR2, switch FN, switch 10 and the operating coil of relay LNG. Relay LCSR also opens contacts LCSR3 after a time interval to deenergize closing coil C. Relay LNG being thus energized opens contacts LNG3 and LNG4 to deenergize relay LZWR and to open a point in the energizing circuit of relay LHR, respectively, and closes contacts LNG1 and LNG2 to energize left nut coke bin fill gate solenoid LFGS and indicator lamp 1L2 across lines L1 and L2. The fill gate operator may be of the well-known fluid type or the like as shown in Fig. 1 having a solenoid operated valve 30 for admitting compressed air into cylinder 28. Energization of solenoid LFGS effects operation of valve 30 to admit compressed air into the opening end of gate cylinder 28 thereby to open gate 26. Nut coke then flows from storage bin 24 into weigh hopper 10.

Should the bin gate opening become jammed with coke to retard or halt the fiow, pushbutton switch JC may be pressed momentarily to close and open gate 26 thereby to dislodge the coke bridging the gate opening. Pressing of switch I C effects deenergization of relay LNG to open contacts LNG1 and LNG2 thereby to denergize solenoid LFGS. As a result, valve 30 is operated to admit com pressed air into the closing end of gate cylinder 28 thereby to initiate closing of gate 26. As will be apparent, release of switch JC to permit the same to close effects re-opening of the bin gate. In this way, momentary operation of switch JC aifords jogging" of gate 26 to clear the opening and permit continuous flow of nut coke from When full weight scale contact FWSC closes or when coke electrodes E1 and E2 are bridged by the coke in weigh hopper 10, depending upon whether fill measurement has been preselected by weight or by volume on switch WV, tripping coil T is energized as hereinbefore described to latch relay LCSR in its normal trip position. Contacts LCSR2 open to deenergize relay LNG, the latter in turn opening contacts LNG1 and LNG2 to deenergize solenoid LFGS to close bin gate 26 as hereinbefore described.

The weigh hopper is ,thus filled with nut coke and the control system is ready to discharge the same into skip car 18 as hereinafter described.

Automatic discharge of weigh hopper To preset the control system for automatically discharging the coke from full weigh hopper 10 into skip car 18, discharge selector switch DS is left in its Auto designating operating position as shown. Selector switch LCS is turned to its On operating position. Assuming that fill selector switch FS is in its Auto designating operating position as shown, relay LOR is energized in the circuit hereinbefore described. Contacts LORI interrupt the shunt across interlocking contacts LHR4 and LZWRI in the skip hoist control circuit, and contacts LOR2 close to partially complete an energizing circuit for weigh hopper discharge gate relay LHR. The weigh hopper 10 being full of coke, relay LFWR is energized, completing at contacts LFWR4 another point in the circult of relay LHR. Relay LZWR is deenergized, its circuitbeing interrupted by scale contact ZWSC and contacts FLWR3.

assent Assuming further that alo'a'd summary program device in the 'char'gingcontr'oller is signaling 'for an autotnatic coke load for the next charge, normally open automatic coke relay contacts ACR are closed. An extra charging loadnot having been initiated, normally closed extra load relay contacts EL are closed and normally open extra coke relay contacts EC are open. For a disclosure of the operating means for the aforementioned contacts ACR, EL and EC, reference may be had to the aforementioned copending application of Douglas W. Path and Charles E. Smith, Serial No. 720,400, filed March 10, 1958.

When left skip car 18 enters charging pit 22, left skipin-pit relay contacts LSP close to complete an energizing circuit for weigh hopper discharge gate relay LHR through discharge selector switch contact D82, contacts LFWR4, ACR, EL LSP, LSCR3, LNG4, LOR2 and LDTI, and the operating coil of relay LHR. As a result, contacts LHRI and LHRZ effect energization of left discharge gate solenoid LDGS across lines L1 and L2. Contacts LHR3 complete a holding circuit for the operating 'coil of relay LHR in shunt of contacts LFWR4 in order "to main tain the relay after coke starts to discharge from Weigh hopper and energization of relay LFWR is interrupted by scale contact FWSC. Relay LHR also opens contacts LHR4 to prevent operation of the skip hoist when coke is being discharged into skip car 18, and closes contacts LHRS to partially complete an energizing circuit for timing relay LDT.

The weigh hopper discharge gate operator may be similar to the hereinbefore described nut coke bin gate operator both of which are shown in Fig. 1. Thus, energization of solenoid LDGS effects operation of valve 16 to admit compressed air into gate cylinder 14 thereby to open gate 12. When discharge gate 12 opens, limit switch DGLSI is reset to its open position 'to prevent filling the weigh hopper, limit switch DGLS3 opens and limit switch DGLS2 closes thereby energizing lamp 1L3 to indicate that gate 12 is open. The coke is discharged from weigh hopper 10 into skip car 18. Full weight scale contact FWSC opens to deener'gize relay LFWR and complete at contacts LFWR3 a point in the energizing circuit of zero weight relay LZ r I When all the coke is discharged from weigh hopper 10, zero weight scale contact ZWSC elfects energization of relay LZWR in the circuit hereinbefore described. Should contact ZWSC, which is scale operated, fail "to close due to some coke sticking in weighhopperlt), zero weight 'pushbut'ton switch ZW may be manually pressed to energize relay LZWR. As a result, contacts LZWRI close to partially complete the skip hoist control circuit, contacts LZWR3 complete a holding circuit for its operating coil in shunt of parallel connected scale contact ZWSC and switch ZW, and contacts LZW-R4 complete an energizing circuit for weigh hopper gate timing relay LDT.

After a predetermined time interval sufficient to permit all the coke to be discharged from weigh hopper 10, relay LDT times out and opens contacts LDTl to interrupt energization of relay LHR. Contacts LHRl and LHR2 interrupt energization of solenoid LDGS whereupon gate valve 16 is operated to admit compressed air into the closing end of cylinder 14 and hopper gate 12 closes. Relay LHR also interrupts its holding circuit at contacts LHR3, closes contacts LHR4 to permit skip hoist operation, and opens contacts LHRS to interrupt energization of timing relay LDT. When hopper gate 12 completely closes, limit switch DGLSI trips to its closed position to partially complete anenergizing circuit for closing coil C,

limitswitch DGLS'Z resets to its open position and limit switch DGLS3 trips to its closed position thereby energizing lamp 1L4 to indicate that gate 12 is closed. When loaded skip car 18 leaves charging pit 22, contacts LSP open.

Assuming that fill selector switch FS is in its Manual designating operating position when automatic discharge it). bfceke from the weigh ho per is initiated, c ontac't'Fsq disconnects relays LFWR and LFVR to render the same ineifective. It will be apparent, however, that although' contacts LFWR4 and LFVR4 in the energizing circuit of relay LHR cannot now be closed, fill selector switch contact PS5 shunts these contacts to enable automaticoperation of the discharge control network.

Manual operation Manual fill To preset the control system for manual fill control, -fill selector switch FS is turned to its Manual designating operating position. Contact PS1 connects power supply line L1 to manual fill switch MF and disconnects the weight-volume automatic stop-filling apparatus. Assuming switch LCS is closed and switch DS is in either its Auto or Manual designating operating position, contact PS3 energizes relay LOR as hereinbefore described. Contact PS4 disconnects relays LFWR and LFVR to render the same ineffective. Contact FSS shunts parellelconnected contacts LFWR4, LFVR4, and LHR3 in the "energizing circuit of relay LHR. The type of coke -is selected on selector switch FN and weigh hopper 10 is filled by turning switch MP to its Start position. To this end, switch MF completes an energizing circuit for closing coil C of relay LCSR through fill selector switch contact FSI, switch MF, limit switch D6181, contacts LCSR3 and closing coil C 'of relay LCSR. As a result, the fill control apparatus operates as hereinbefore described to fill weigh hopper 10 with either furnace coke or nut coke as selected.

It will be apparent that when the fill control network is under manual operation, the full weight and full volume automatic turn-oif circuits are ineifective. Therefore, the operator must stop the filling operation manually when the desired amount of coke has been deposited in weigh hopper 10. This is accomplished by turning switch MF back to its Stop position. As a result, tripping coil T of relay LCSR is energized in a circuit extending through fill selector switch contact FSl, switch MF, contacts LCSRl and tripping coil T, whereupon the filling operation is stopped as hereinbefore described.

Manual discharge To preset the control system for manual dis'chargecontrol, discharge selector switch DS is turned to its Manual designating operating position. Assuming switch LCS is closed and fill selector switch FS is in either its Auto or Manual designating operating position, contact DSl energizes relay LOR as hereinbefore described. Contact DSZ connects power supply line L1 to manual discharge switch MD, and contact DS3 disconnects timing relay LDT to render the same ineffective.

Assuming that skip car 18 is in pit 22 and, therefore, contacts LSP are closed, as shown in Fig. l, the coke in weigh hopper 10 may be discharged into skip car 18 by turning switch MD to its Open designating operating position. To this end, relay LHR is energized in a circuit extending through contact D82, switch MD, contacts LSP, =LSCR3, LNG4, LOR2 and LDTl and the operating coil of relay LHR. Asa result, relay LHR eflects opening of weigh hopper discharge gate 12 as hereinbefore described to discharge the coke into the skipcar and opens contacts LHR4 to prevent operation of the skip hoist until the coke has been discharged into the skip car. When all the coke has been discharged from the weigh hopper, zero weight scale 'contact ZWSC closes to complete the aforementioned energizing circuit for relay LZWR whereupon the latter closes contacts LZWRI to partially complete the skip hoist control circuit.

The weigh hopper discharge gate is closed by turning switch MD back to its Close position. As a result, relay LHR is restored and the gate is closed as hereinbefore described. Contacts LHR4 close to permit skip hoist operation.

Lockout If the left fill control apparatus becomes inoperative, the filling operation can be locked out by turning fill selector switch PS to its Off position. Relay LOR is deenergized to prevent discharging of the coke from the left weigh hopper into the skip car, contacts LOR2 being open. Contacts LORI close to permit skip hoist operation.

Relay LOR also signals the charging control system to by-pass the left coke system and obtain each coke charge from the right coke system. To this end, the fragmentary load summary program control circuit shown in the left-hand portion of the drawing is operated as hereinafter described.

Under normal automatic operating conditions, left coke system off relay LOR and a similar right coke system off relay are energized thereby closing contacts LOR4 and RORl and opening contacts LOR3 and ROR2. Therefore, each time the left skip car is hoisted and contacts HLZ close, a load summary program control device LSPC is energized in a circuit extending from line L through contacts HLZ and LOR4 to program device LSPC and closes automatic coke relay contacts ACR and corresponding contacts in the right coke system if coke has been preselected for the next load. Similarly, each time the right skip car is hoisted and contacts HRI close, device LSPC is energized in a circuit extending from line R through contacts HRI and RORl to device LSPC and closes contacts ACR and corresponding automatic coke relay contacts in the right coke system. In this way, each skip load is registered in the load summary program device LSPC, the latter preparing the left and right discharge control networks for operation and comprising apparatus which controls the charging program as more fully described in the aforementioned Douglas W. Path and Charles E. Smith copending application Serial No. 720,400 filed March 10, 1958.

Assuming now that the left filling operation is locked out by turning fill selector switch PS to its off position to restore relay LOR. Alternatively, relay LOR can be restored by turning switch LCS to its off position. Restoration of relay LOR effects not only closure of contacts LORI and opening of contacts LOR2 as hereinbefore described but also closure of contacts LOR3 and opening of contacts LOR4. Now, when the empty left skip car is hoisted and contacts HL2 and HL3 close, an energizing circuit cannot be established from line L to device LSPC for the reason that contacts LOR4 and ROR2 are open. The empty skip car, therefore, is not registered and the left coke system is by-passed. Consequently, the scheduled coke load is charged by the right skip car.

If the left discharge control mechanism becomes inoperative, the discharging operation can be locked out by turning discharge selector switch DS to its Off position. This will permit automatic or manual filling of the weigh hopper but will prevent discharge of coke from the weigh hopper into the skip car by virtue of relay LOR being restored and contacts LOR2 open. As before, closure of contacts LORl permits skip hoist operation and the charging control system is signaled to send the left skip carup empty and to obtain the coke charge from the right weigh hopper.

In the event a failure occurs in both the left and right coke systems so that either the fill or discharge control apparatus in each of these systems must be locked out by turning the corresponding selector switches to their ofi positions and hence restoring relay LOR and the corresponding right coke system off relay, emergency override apparatus may be provided for dumping nut coke into the skip car. To this end, the nut coke bin fill gate solenoid LFGS and the weigh hopper discharge gate solenoid LDGS may be provided with mechanical push-rod type override levers (not shown) for manually operating the gate valves. Operation of these levers affords opening of nut coke storage bin gate 26 to fill the weigh hopper and opening of weigh hopper gate 12 to discharge the nut coke into the skip car. Under these conditions, contacts LOR3 and ROR2 are closed so that when each skip load is hoisted, the latter is registered in the load summary program device LSPC.

We claim:

1. In a material handling control system for filling a hopper with a predetermined quantity of selected material from preselected storage bins and for thereafter discharging the material from the hopper into a material conveying receptacle, in combination, control means responsive to initiation of movement of the receptacle away from the hopper for filling the hopper with a predetermined quantity of material, control means responsive to movement of the receptacle to a predetermined position relative to the hopper for discharging the material from the latter into the receptacle, and means interlocking said filling control means and said discharging control means to prevent discharging material from the hopper when the latter is being filled and to prevent filling the hopper with additional material when the full hopper is being discharged.

2. In a material handling control system for filling a hopper with a predetermined quantity of selected material from preselected storage bins and for thereafter discharging the material from the hopper into a material conveying receptacle, in combination, control means responsive to initiation of movement of the receptacle away from its stopping position at the hopper for filling the latter with a predetermined quantity of material, hopper discharging control means, measuring means responsive to said hopper receiving said predetermined quantity of material for preparing said discharging control means for operation, and means responsive to return of the receptacle to its stopping position at the hopper for effecting operation of said discharging control means to discharge the material from the hopper into the receptacle.

3. The invention defined in claim 2, together with presettable means for affording automatic operation of said filling control means in response to initiation of receptacle movement when set therefor and for affording manual operation of said filling control means when set for the latter, said presettable means comprising means effective when set for manual operation for rendering said measuring means ineffective and for preparing said discharging control means for operation.

4. The invention defined in claim 3, together with additional presettable means for affording automatic operation of said discharging control means in response to return of the receptacle to said stopping position when set therefor and for affording manual operation of said discharging control means after said receptacle has re turned to said stopping position when set for the latter, and manual control means selectively operable to control said discharging control means independently of said measuring means and the first mentioned presettable means when said additional presettable means is set for manual operation.

5. In a material handling control system for filling a hopper with a predetermined quantity of preselected material from storage bins and for thereafter discharging the material from the hopper into a conveyor car, hopper filling control means comprising presettable means for selecting one of a plurality of different materials for filling the hopper, means responsive to operation of the conveyor car when said presettable means is set for initiating deposit of said selected material in the hopper, means associated with the hopper for measuring a predetermined quantity of material, and means responsive to said measuring means for stopping the filling of said hopper when said predetermined quantity of material has been deposited therein.

6. The invention defined in claim 5, together with additional presettable means for conditioning said filling control means for manual operation, and manual control means effective when said additional presettable means is set for selectively operating said filling control means to deposit a desired amount of said selected material in the hopper.

7. In a material handling apparatus having a pair of material handling systems and a pair of interconnected conveyor receptacles respectively associated therewith for alternately conveying material loads from one point to another and a pair of loading mechanisms respectively associated with the systems and the receptacles for loading material into each receptacle when it is moved to its stopping position adjacent the associated loading mechanism, in combination, a pair of material control networks alternately operable for controlling the loading mechanisms to discharge material into the associated receptacles when the latterenter their stopping positions, switch means operable to render one of said material control networks ineffective, and means operable in response to rendering said one material control network ineffective for conditioning the apparatus to by-pass the ineffective material control system to prevent loading of the associated receptacle and to obtain each material load under the control of the effective control network and the other receptacle.

8. In a coke charging apparatus for a blast furnace having left and right coke control systems and left and right skip cars respectively associated therewith and arranged in counterbalancing relation for alternately conveying coke loads from a charging pit to a distributor hopper at the furnace top, in combination, left and right coke control networks alternately operable in response to skip car operation for controlling discharge of coke into the corresponding skip car when the latter enters the charging pit, switch means operable for rendering one of said coke control networks ineffective, and means operable when one of said coke control networks is rendered ineffective for by-passing the ineffective coke control system and the corresponding skip car and obtaining each coke load under the control of the effective coke control network and the other skip car.

9. The invention defined in claim 8, wherein the last mentioned means comprises load summary programcontrol means normally responsive when each skip car is moved from the charging pit for preparing said coke control networks for operation to be effected when the next skip car enters the charging pit, and means responsive to operation of said switch means in said one coke control network for rendering said load summary program control means ineffective to prepare said one coke control network for operation when the skip car corresponding to the other effective coke control network is moved from the charging pit, said load summary program control means remaining effective to prepare said other coke control network for operation when the skip car corresponding to the latter is moved from the charging pit whereby the ineffective coke control system is by-passed and each coke load is obtained under the control of the effective coke control system.

10. In a material handling system having left and right hoppers for receiving and discharging material and left and right conveyors respectively associated therewith for alternately conveying the material discharged therein from the hoppers, in combination, a left control system 7 1'4 comprising means normally operable to control filling of the left hopper each time the left conveyor is moved away from the left hopper and means normally operable to control discharging of the material from the left hopper into the left conveyor each time the latter is returned to its stopping position below the left hopper, a right control system comprising means normally operable to control filling of the right hopper each time the right conveyor is moved away from the right hopper and means normally operable to control discharging of the material from the right hopper into the right conveyor each time the latter is returned to its stopping position below the right hopper, a load summary program device comprising first means normally responsive to initiation of movement of the left conveyor away from the left hopper for preparing said discharging control means of the left and right control systems for operation to be effected when the associated conveyor is returned to its stopping position and second means normally responsive to initiation of movement of the right conveyor away from the right hopper for preparing said discharging control means of the left and right control system for operation to be effected when the associated conveyor is returned to its stopping position, means for rendering a selected one of said left and right control systems ineffective, and means responsive to the last mentioned means for rendering the associated one of said first and second means ineffective thereby to by-pass said ineffective control system and obtain each load of material under the control of the effective control system.

11. In a material handling control system for filling a hopper with a predetermined quantity of selected material from storage bins and for discharging the material from the hopper into a conveyor receptacle, in combination, presettable means for selecting one of a plurality of different materials, filling means operable when the receptacle is moving away from the hopper, means responsive to operation of said filling means when said presettable means is set for depositing the selected material into the hopper, means operable when the receptacle again moves to a predetermined position relative to the hopper for discharging the selected material from the latter into the receptacle, and means interlocking said filling and discharging means to prevent filling of additional material into the hopper while the material in the latter is being discharged and to prevent discharging of material from the hopper when the latter is being filled.

12. In a material handling control system for filling a hopper with a predetermined quantity of selected material from storage bins and for discharging the material from the hopper into a conveyor receptacle, in combination, means for filling a predetermined quantity of material into the hopper, means to effect automatic operation of said filling means concurrently with movement of the receptacle, means to preset said filling means for manual operation, manual control means effective when said presetting means is set for selectively operating said filling means thereby to deposit a desired amount of material in the hopper, means operable when the receptacle again moves to a predetermined position relative to the hopper for discharging the material from the latter into the receptacle, and means interlocking said filling and discharging means to prevent filling of additional material into the hopper while the material in the latter is being discharged and to prevent discharging of material from the hopper when the latter is being filled.

13. In a material handling control system for filling a hopper with a predetermined quantity of selected material from storage bins and for discharging the material from the hopper into a conveyor receptacle, in combination, means operable when the receptacle is moving away from the hopper for filling a predetermined quantity of material into the hopper, means operable when the receptacle again moves to a predetermined position relative to the hopper for discharging the material from the latter into the receptacle, means associated with the hopper for measuring a predetermined quantity of material comprising presettable means for effecting measurement of the material by weight when set therefor and for effecting measurement of the material by volume when set for the latter, and means responsive to said measuring means for stopping said filling means when said predetermined qu antity of material has been deposited in the hopper.

14. The invention defined in claim 13, together with means operative when said presettable means is set for measurement of material by weight for rendering said volume measuring means operative in the event of failure of said weight measuring means.

15. In a material handling control system for filling a hopper with a predetermined quantity of selected material from storage bins and for discharging the material from the hopper into a conveyor receptacle, in combination, means operable when the receptacle is moving away from the hopper for filling a predetermined quantity of material into the hopper, means for discharging the material from the hopper into the receptacle, means to effect operation of said discharging means automatically in response to movement of the receptacle to a predetermined position relative to the hopper, means to preset said discharging means for manual operation, and manual control means effective when said presetting means is set for operating said discharging means.

16. In a material handling control system for filling a hopper with a predetermined quantity of selected material from storage bins and for discharging the material from the hopper into a conveyor receptacle, in combination, means responsive to initiation of movement of the receptacle away from the hopper for filling the hopper with a predetermined quantity of material, means for discharging said material from the hopper into the receptacle,

means to effect operation of said discharging means automatically in response to movement of the receptacle to a predetermined position relative to the hopper, timing means for maintaining operation of said discharging means for a predetermined time interval, and electroresponsive means operable in response to discharge of the material from said hopper for initiating operation of said timing means, and said timing means operating at the end of said time interval to terminate the discharging cycle.

17. The invention defined in claim 16, wherein said electroresponsive means comprises means responsive to discharge of substantially all the material from the hopper for energizing the same, and manual control means for insuring energization of said electroresponsive means in the event of failure of the last mentioned means to energize said electroresponsive means.

18. In a material handling control system for filling a hopper with a predetermined quantity of selected material from storage bins and for discharging the material from the hopper into a conveyor receptacle, in combination, means operable when the receptacle is moving away from the hopper for filling a predetermined quantity of material into the hopper, means operable when the receptacle again moves to a predetermined position relative to the hopper for discharging the material from the latter into the receptacle, first presettable means for efiecting automatic operation of said filling means when set therefor and for affording manual control of the operation of said filling means when set for the latter, second presettable means for effecting automatic operation of said discharging means when settherefor and for affording manual control of the operation of said discharging means when set for the latter, first manual control means selectively operable to control said filling means when said first presettable means is set for manual operation regardless of the setting of said second presettable means, and second manual control means selectively operable to control said discharging means when said second presettable means is set for manual operation regardless of the setting of said first presettable means.

19. In a material handling control system for filling a hopper with a predetermined quantity of selected material from storage bins and for discharging the material from the hopper into a conveyor receptacle, in combination, means operable when the receptacle is moving away from the hopper for filling a predetermined quantity of material into the hopper, means operable when the receptacle again moves to a predetermined position relative to the hopper for discharging the material from the latter into the receptacle, first presettable means for effecting automatic operation of said filling means when set therefor and for affording manual control of the operation of said filling means when set for the latter, second presettable means for effecting automatic operation of said discharging means when set therefor and for affording manual control of the operation of said discharging means when set for the latter, first manual control means selectively operable to control said filling means when said first presettable means is set for manual operation and said second presettable means is set for automatic operation, and second manual control means selectively operable to control said discharging means when said second presettable means is set for manual operation and said first presettable means is set for automatic operation.

20. In a material handling control system for filling a hopper with a predetermined quantity of preselected material from storage bins and for thereafter discharging the material from the hopper into a conveyor car, the latter having a normal stopping position below the hopper, the combination with a hopper discharge gate operable to discharge material from the hopper into the conveyor car, of hopper discharge control means comprising means responsive to operation of the conveyor car to its stopping position when the hopper is full of material for opening said gate and means responsive to discharge of the material from the hopper for closing said gate, conveyor car control means, interlocking means responsive to said gate opening means for preventing operation of said conveyor car control means until said gate closing means has operated, presettable means for conditioning said discharge control means for manual operation, and manual control means effective when said presettable means is set for selectively operating said discharge control means to open and close said gate, said interlocking means being effective to prevent operation of said conveyor car control means until said manual control means has been operated to initiate closing of said gate.

References Cited in the file of this patent UNITED STATES PATENTS "new

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