US2072747A - Carrier system - Google Patents

Description

March 2, 1937. c. H. FREESE CARRIER SYSTEM FiledJan. as, 1932.

2 Sheets-Sheet 1 Inv e'ribov: CLqde H. Ffeese.

His AtbOYHGH.

March 2, 1937. Q sg 2,072,747

CARRIER SYSTEII Filed Jan. 23, 1932 2 Sheets-Sheet 2 Inventor": Clyde H. Freese,

His Attorney.

Patented Mar. 2, 1937 UNITED STATES PATENT OFFICE CARRIER SYSTEM Application January 28, 1982, Serial No. 588,368

My invention relates to carrier systems and has for an object the provision of a simple and reliable control system which may automatically or under manual control repeatedly carry out a predetermined cycle of operation.

My invention has general 899110861011 to systerns wherein a carrier is adapted to be set in operation. as for example at a loading station and thereafter travel to another station such as a dumping station where it is automatically reversed and brought back to the loading station. In coal handling systems of this type, it is the usual practice to have a plurality of storage silos arranged on either side of a loading pit into which the coal is first dumped from the railroad cars.

Heretofore track limit switches have been used to .control the energization of the trolley and hoisting motors. The problem of wiring in limit switches of this type is difllcult due to the relatively small space available on the track. Furthermore, every installation requires the large amount of field work necessary to the installation and to the wiring oi the switches.

An important ieature of my invention is its adaptability to existing installations, a minimum amount of wiring and initial adjustment being required. This feature of my invention is obtained by the use of geared limit switches so that duplicate control equipment may be used regardless of the number of silos or their location with respect to the loading pit.

In carrying out my invention in one form I provide a plurality of interlocking control circuits so that when one of the driving motors is energized for a, particular movement of the carrier, the

other motor may not be energized until the carrier has completed that particular movement. For example, when the hoisting motor is energized to hoist the bucket from the loading pit,

0 the trolley motor cannot be energized. However, as soon as the bucket has been hoisted to the proper elevation above the silos or unloading stations, a position responsive switch serves to deenergize the hoisting motor and to energize the 5 trolley motor. I further provide a geared limit switch having a group of contacts for stopping the bucket over the loading pit and a group of contacts for stopping the bucket over a silo. An adjustable connection between the respective 5,0 groups of contacts varies the operation of the group of contacts for the silo with respect to the contacts for the pit so that any particular silo may be selected for the carrying out of the cycle irrespective of the number oi silos or the distance '55 between them.

In the form of my invention shown the system may be operated continuously, the establishment and interruption of the control circuits being entirely automatic. The transfer from one control circuit to a second control circuit always depends upon the establishment of the prior control circuit and upon the positionof the bucket with respect to the material handling apparatus. The system may also be operated manually. But for the manual control I retain the advantages of the interlocked circuits so that the operation is semi-automatic, that is to say, each movement of the bucket is initiated by the operation of a push button, but the bucket is automatically stopped as soon as the movement is completed.

For a more complete understanding of my invention, reference should now he had to the drawings, in which Fig. 1 shows a perspective view of a plurality of silos together with the driving motors controlled in accordance with my invention; Fig. 2 is a perspective view partly in section of an adjustable limit switch used for the selection of a particular silo which is to be filled; and Fig. 3 diagrammatically illustrates a control circuit embodying my invention as applied to the material handling apparatus shown in Fig. 1.

Referring now to Fig. 1, I have shown my invention in one form as applied to the control of a hoisting motor l0 and of a trolley motor II which motors serve to drive a material carrying bucket l2 through the predetermined cycle of operation. The bucket I2 is supported by a cable I! and a carriage l4 mounted on a track or I- beam l5.

' To provide for the hoisting and lowering of the bucket, the cable It, secured at one end to the I- beam as indicated by the reference numeral I8, is threaded over a pulley H on the carriage, under a pulley it carried by the bucket, over a pulley l8 on the carriage, and over a pulley 20, suitably mounted on the supporting frame (not shown) of the carriage track l5, and thence to the cable drum 2| driven by the hoisting motor Ill through the gear 22.

To provide for traverse of the bucket l2 over the silos 23, 24, 25 and 26, an extension 28 of the carriage i4 is secured to the cable 21. This cable is wound over a cable drum 29 driven by the trolley motor II by means of the gear 30 and is threaded over pulleys 3i and 32 carried by the track support (not shown) and a pulley 88 mounted on the track or I-beam It. It will be observed that the silos 23 and 24 are on the left hand side of the track 34 leading through the hatchway 35 to the loading pit (not shown) while the silos 25 and 26 are on the right hand side of the pit 35.

A hoisting limit switch 36 having normally open and normally closed contacts is geared to the hoisting cable drum 2|; and similarly trolley limit switch 31 is geared to the cable drum 29. It will be observed that the trolley limit switch 31 shown in Fig. 2 consists of a plurality of lug carrying disks 38, 39, 48, 4|, 42 and 43. Each disk, as for example, the disk 38, is provided with holes 44 distributed about its periphery so that the lugs 45, 46 and 41 secured thereto may be adjusted to the desired angular position. The lug 45 serves to close the switch It will be observed that the contact carrying member 58 is pivotally mounted on a shaft 59 so that when the lug 45 engages a small metal wheel 60 carried on the lower part of the armature, the armature is forced outwardly against a compression spring 6| closing the switch. The contacts 5| are latched to their closed position by means of a member 82 pivotally carried by a shaft 63 and biased upwardly against the notched lower end 58a of the armature 58 by means of a compression spring 64. The contacts are opened by either the lug 46 or the lug 41 engaging the small wheel 65 carried by the member 62. The engagement of the small wheel with a lug causes the member 62 to disengage itself from the notched end 58a of the armature 58 so that the compression spring 6| operates the switch to its open position. It will of course be understood that the remaining contacts are similarly constructed and operated.

The selection of a silo into which coal or a like material is to be transported is accomplished by the adjustment of the operating means for the two sets of contacts. For example, the relative angular position of the disks 38, 39 and 48 with respect to the disks 4|, 42 and 43 is varied to change the time of operation of one group with respect to the other. The latter group of contact operating disks serves to stop the traverse or trolley motion of the bucket whenever it reaches a position above the hatchway 35, while the former group of disks serves to stop the bucket over a selected silo. During normal operation, the disks are driven directly by the shaft 66, rotated with the cable drum 29. It will be observed that the disks 38, 39 and 48 are rotated by reason of an adjustable driving connection which connection comprises meshing gears 61, 68, 69 and 10. The gear 68 is secured to a shaft 1| supported in a tubular housing 12 which housing carries the gear 69. The shaft and housing are locked together by means of a Wedge 13, the latter being provided with a threaded bore for engagement with the end of the shaft 1|. Therefore, it will be observed that if the wedge is released the housing 12 may be rotated to drive the gears 69 and consequently varying the relative position of the disks 38, 39 and 40 with respect to disks 4|, 42 and 43. As shown, the indicator 14 indicates that the second. silo 23 on the left of the pit (2L) is to receive coal. If the silo 24 is to be filled, the wedge 13 is rotated in a direction so that the housing 12 may be rotated independently of the shaft 1|. The indicating dial formed by the outwardly flaring extension of the housing 12 is then rotated until the indicator 14 coincides with the position marked IL. The relative adjustment of the contact operating disks causes the bucket |2 to stop over the silo 24 instead of the silo 23.

Actually there are eight contacts on the trolley limit switch, additional contacts being provided on each extremity of the assembly shown in Fig. 2,

For the purpose of simplifying the drawings the additional contacts have been omitted from this figure. The contacts 50, 5|, 52 and 53 (Fig. 3) are adjustable with respect to the contacts 54, 55, 56 and 51.

As shown in Fig. 3, the hoisting motor I8 is of the slip ring type while the trolley-motor II is of the squirrel cage type. However, it is to be understood that the principles embodied in my motor control circuit are flexible enough to apply to any type of motor drive and to d. 0. motor drive as well as to a. 0. motor drive. It is also to be understood that while I have discussed my invention in connection with a certain type of coal handling or storage equipment, it can also be applied for any application having a similar duty cycle requirement.

The energization of the hoisting motor I8 is controlled by a hoisting switch 88 and lowering switch 8| together with a hoisting relay 83 and a lowering relay 82. The latter relays serve to energize the first and second accelerating contactors 84 and 85. Similarly, the energization of the trolley motor H is determined by the direction controlling switches 86 and 81. The latched in sequence interlocking relays 88, 89 and 90 insure the continuance of the predetermined cycle by providing interlocking control circuits.

A slack cable switch 9| is arranged to open a pair of contacts 92 to deenergize the hoisting motor l0 whenever the bucket is lowered into engagement with the material within the silo or into the loading position in the pit. As the switch contacts 92 are opened, a second pair of contacts 93 are closed to initiate a reversal of the hoisting motor so that the bucket is hoisted out of the silo. After being hoisted out of the silo, the bucket is trolleyed towards the loading hatchway 35. After the bucket is centered over the hatchway a time delay switch 94 delays the energization of the lowering circuit until the oscillations of the bucket have greatly diminished or stopped entirely. A time switch 95 delays the energization of the hoisting motor when the bucket reaches its loading position in the pit, so that it remains in the loading position a sufficient time for the bucket to take on a load of coal. The time switch 96 serves to introduce a short interval of time after the bucket is stopped over a silo and before the lowering switch is energized so that the bucket will not be oscillating to any great extent as it is lowered into a silo. For manual operation the four pole single throw switch 91 is left open and for automatic operation it is closed. A four pole double throw switch 98 is provided to reverse the relative energization of the trolley direction switches 86 and 81 depending on whether the bucket is to carry material to a right or left hand silo.

With the above understanding of the elements and their organization with respect to each other in the system, the operation of the system itself and the function of the sequence relays 88, 89 and 98 with the hoisting limit switch 36 and the trolley limit switch 31 and the manner in which they cooperate to provide interdependent circuits will be readily understood from the description which follows:

It will be assumed that the bucket I2 is in the loading position in the pit and that it is desired to automatic-ally operate the bucket l2 to transfer coal from the pit to the second left hand silo 23. Accordingly the four pole single throw switch 91 will be operated to its left hand position for the automatic operation of the system.

it will also be assumed that the supply lines Ill and I02 are connected by the line switches I and I00 to a suitable source, of supply as indicated by the conductors I00 and Ill. It will also be assumed that the hoisting motor I0 and the trolley motor II may be energized from a suitable source of three phase alternating current supply as is indicated by the supply lines I00. Inasmuch as it is desired to carry coal to the left hand silo .20, the four pole switch 00 is moved to its left hand position so that the bucket I2 will be driven to the left after it is hoisted from the pit instead of to the right, as would be the case it the switch 00 had been moved to its right hand position.

with the bucket in the loading pit, as soon as the supply lines III and I02 are energized by the closing of the line switches I00 and I00. the sequence relay 00 is operated to its latched position by reason of an energizing circuit which may be traced from supply line IIiI, conductor IIO, contacts 00 of the slack cable switch 0|, conductors III and H2, trolley limit switch contacts l0, conductor III, operating coil Ill of the sequence relay 00, and by conductor IIO to the other supply line I02. The sequence switch 00 is thereupon operated to open its contacts I I0 and Ill and to close its contacts III, III and I20. It will be observed that as the relay 00 closes, a latching member I2I pivoted at I22 engages a shoulder I20 provided on the switch 00 so as to latch the relay 00 into position.

A second energizing circuit may be traced for the operating coil of the time relay 00 which relay controls the energization of the sequence relay 00. The former circuit may be traced from the supply line III, conductor IIO. contacts 00 oi the slack cable switch 0|, conductors III and I20 operating coil of time relay 00 and by conductor I20 to the other supply line I02. After a predetermined interval of time, corresponding to the time required for loading the bucket in the pit, the time relay 00 closes its contacts establishing an energizing circuit for the operating coil of the sequence relay 00 which circuit may be traced from supply line IOI, conductor IIO, contacts 00 of slack cable switch 0|, conductors I and I20,, contacts of the time relay 00. conductor I20, operating coil I21 of relay 00 and by conductor I20 to the other supply line I02. The sequence relay 00 is thereupon-operated to open its contacts I20 and I00 and to close its con- :iacts III and I02. This relay is latched into position in the same manner as described in connection with the sequence relay 00.

The closing of the contacts IOI of relay 00 completed an energizing circuit for the hoisting switch 00 which circuit may be traced from supply line "I, conductor I00, contacts I04 of switch 01, conductors I00, I00 and I01, hoisting limit switch I 00, conductor I00, contacts IOI, conductor I00, operating coil oi the direction switch 00, and by conductors Ill and I02 to the other supply line I02.

It should here be observed that the completion of the latter circuit depends upon the relay 00 being in its latched position. It will also be observed that the circuit for the relay 00 was traced through the non-adjustable trolley limit switch contacts 00 and that the control circuit for the i hoisting switch 00 was completed through the hoisting limit switch I00 and the contacts IOI of the sequence relay 00. This interlocking of circuits is an important feature of my invention and insures at all times the carrying out of the desired 5 cycle of operations.

Continuing with the operation of my invention, the hoisting switch 00 is operated to its closed position to energize the hoisting motor I0 in a direction to hoist the bucket from the pit. Inasmuch as the resistances I00 and I are connected in the rotor circuit of the hoisting motor I0, the motor first rotates at low speed. However the operating coil of the time delay hoisting relay 00 is connected by means of conductors I00 and I00 in parallel with the operating coil of the direction switch 00, so that the hoisting relay 00 is energized simultaneously with the direction switch 00. The contacts I01 of the hoisting relay 00 are immediately closed but the closing of the contacts I00 is delayed by reason of a time delay I00. After a short interval of time the contacts I00 close to complete an energizing circuit for the first accelerating contactor 00. This circuit may be traced from the supply line IOI, conductor I00; contacts I00, conductor I 0|, operating coil of the accelcrating contactor 00 and by conductor I02 to the other supply line I02. The first accelerating contactor 00 thereupon closes to short circuit the resistors I00 from the rotor circuit of the motor I0 thereby causing the motor I0 to be accelerated to a higher speed. After a predetermined interval of time, the time delay contacts I00 of the contactor 00 are closed to complete a circuit for the second accelerating contactor 00. 'This circuit may be traced from supply line IOI, conductor I00, contacts I00, conductor IOI, contacts I00, operating coil of the accelerating contactor 00 and by conductor I02 to the other supply line I02. The second accelerating contactor 00 thereupon closes short circuiting the resistors I thereby causing the hoisting motor I0 to be accelerated to its high speed.

As the bucket I2 is hoisted to its trolleying position above the silos, the hoisting switch contacts I00 are operated to their open position while the hoisting limit switch contacts I00 are operated to their closed position. The opening of the hoisting limit switch contacts I00 deenergizes the hoisting switch 00, the hoisting motor I0, the hoisting relay 00, and the accelerating contactors 00 and 00.

The closing of the hoisting limit switch contacts I00 establishes an energizing circuit for the trolley direction switch 01, which circuit may be traced from supply line IOI, conductor I00, hoisting limit switch contacts I00, conductors I01 and I00, contacts I00, conductors I00, IN and I02, contacts I00 of the sequence relay 00, conductor I00, contacts IIO of the sequence relay 00, conductor I00,

adjustable trolley limit switch contacts 02, conductor I00, switch 00, conductor I00, operating coil of the direction switch 01, and by conductors I00 and I02 to the other supply line I02. The direction switch 01 is thereupon operated to its closed position to energize the trolley motor II in a direction to drive the bucket over the left hand silo. It will again be observed that this control circuit depends on the positions of the sequence relays 00 and 00, the hoisting limit switch I00, and the adjustable trolley limit switch 50.

As the bucket I2 moves toward the selected silo, 20, the non-adjustable contacts 0|, of the trolley limit switch 01 are operated and latched into their closed position while the contacts 04, 00 and 01 of this switch are opened. When the bucket I2 has been driven to a position over the selected silo 22, the contacts 00, 03 and 00 of the limit switch 01 are operated and latched into their closed circuit positions while the contacts 02 of this limit switch are opened. Inasmuch as the energizing circuit for the direction switch 81 was completed through the adjustable limit switch contacts 52, the opening 01' these contacts immediately deenergizes the direction switch 81 thereby deenergizing the trolley motor I I.

The closing of the adjustable trolley limit switch contacts 50 completed a trip circuit for the sequence relay 88. This circuit may be traced from supply line IOI, conductor I10, limit switch contacts 50, conductor I1I, contacts II8, conductor I12, contacts I32, trip coil I13 and by conductor I28 to the other supply line I02. The trip coil thereupon withdraws the latching member I14 from its. engagement with the shoulder provided on the relay armature so that this relay is operated to its unlatched position. After the relay 88 has been tripped the trip coil oi. the sequence relay (:9 is energized through a circuit which may be traced from supply line IOI, conductor I10, limit switch contacts 50, conductor I1I, conductor I15, contacts I29, conductor I16, contacts I20, trip coil I11 oi the sequence relay 88 and by conductor II5 to the other supply line I02. The sequence relay 89 is thereupon operated to open its contacts H8, H9 and I20 and to close its contacts II 6 and H1.

The closing of the adjustable trolley limit switch contacts 53 completes an energizing circuit for the time delay relay 96 which may be traced from supply line IOI, conductor I10, limit switch contacts 53, conductor I18, operating coil of the time relay 96, and by conductor I19 to the other supply line I02. After a short interval of time which permits the bucket I2 to come to a standstill, the contacts I are closed to complete an energizing circuit for the operating coil of the lowering switch 8I. This circuit may be traced from supply line IOI, conductor I33, contacts I8I, conductors I82 and I83, contacts I80, conductor I84, contacts 92 of the slack cable switch 8I (which it will be remembered were closed when the bucket was hoisted from the pit), conductors I and I86, the operating coil of the lowering switch 8I, conductors I81 and I88, contacts I 30,

. and by conductor I89 to the other supply line I02.

The lowering switch 8| is thereupon operated to energize the hoisting motor I0 in a direction to lower the bucket into the selected silo 23. The operating coil of the lowering relay 82 is connected in parallel with the operating coil of direction switch 8| by conductors I and I9I. Consequently after a predetermined interval of time the relay 82 closes its contacts I 92 to energizethe first accelerating contactor 84, which in turn after a lapse of a predetermined interval 01' time, energizes the accelerating contactor 85 so that the motor I0 is accelerated from its low speed to its full speed.

As soon as the bucket I2 strikes the coal within the silo the slack cable switch 9I operates to open its contacts 92 and to close its contacts 93. The opening of this former contact serves to deenergize the lowering switch 8I which is operated to its open position to deenergize the hoisting motor I0.

The closing of the contacts 93 of the slack cable switch 9i completes an energizing circuit for the sequence relay 88. This circuit may be traced from the supply line IOI, conductor IIO, con tacts 93, conductors III, I24 and I95, contacts Ib of the time switch 96, conductors I95c and I26, operating coil I21 of the sequence switch 88, and by conductor I 28 to the other supply line I02. The sequence relay 88 is thereupon operated and latched into position. A circuit is completed for the hoisting switch 80 by the closing of the contacts I3I oi the relay 88 which circuit may be traced from supply line IOI, conductor I33, contacts I34, conductors I35, I36 and I31, limit switch I38, conductor I39, contacts I II, conductor I 40, the operating coil of hoisting switch 80 and by conductors HI and I42 to the other supply line I02. Consequent to the closing 01 the direction switch 80, the hoisting motor I0 is energized in a direction to hoist the bucket from the silo. As before the motor will first rotate at low speed and then be accelerated to its intermediate and full speeds due to the successive operation of relay 82 and the accelerating contactors 84 and 85.

As soon as the bucket I2 reaches a. position above the silos, the limit switch contacts I38 are operated to their open position while the limit switch contacts I54 are closed. As beiore, the opening of the contacts I38 deenergizes the hoist ing switch 80. The closing of the hoisting limit switch contacts I54 serves to complete an energizing circuit for the trolley direction switch 86 which circuit may be traced from supply line I0 I, conductor I56, limit switch I 54, conductors I51 and I58, contacts I95, conductors I86, I91 and I98, contacts I99 of sequence relay 90, conductor 200, contacts II6 oi sequence relay 89, conductor 20I, trolley limit switch 5I, conductors 202 and 203, conductor 204, operating coil of the direction switch 86, and by conductor I42 to the other supply line I02. The direction switch 86 is thereupon closed to energize the trolley motor II in a direction to move the bucket towards the loading pit.

As the bucket moves toward the pit 35, the trolley limit switch contacts 50, 53 and 55 are operated to their open positions while the adjustable contacts 52'are operated to their closed positions. When the bucket reaches a position directly over the pin, the trolley limit switch contacts 5| are operated to their open positions and the trolley limit switch contacts 54, 56 and 51 are operated to their closed positions. The opening of the non-adjustable contacts 5I deenergizes the direction switch 86 which switch opens to deenergize the trolley motor II thereby stopping the travel of the bucket. The closing of the nonadjustable contacts 51 completes an energizing circuit for the trip coil of the sequence relay 90 which circuit may be traced from supply line I0 I, conductor I10, limit switch 51, conductor 205, contacts 206, trip coil 201 of relay 90 and by conductor I94 to the other supply line I02.

The closing of the non-adjustable contacts 54 causes the energization of the trip coil of the sequence relay 88 through a circuit which may be traced from supply line IOI, conductor I10, limit switch contacts 54, conductor 208, contacts II1, conductor I12, contacts I32, trip coil I13 of sequence switch 88 and by conductor I28 to the other supply line I02.

The tripping of the sequence relay 88 causes the contacts I30 to close thereby completing an energizing circuit for the operating coil of the time switch 94. This circuit may be traced from supply line IOI, conductor I33, contacts I 8i, conductors I 82, I83 and 209, operating coil of time switch 94, conductors 2I0 and I 88, contacts I30 of sequence relay 88 and by conductor I89 to the other side of the supply line I 02. After a predetermined interval of time has elapsed, the contacts of the time delay switch 94 close to energize the lowering switch 8I.

This interval of time is introduced in order that the bucket I2 may its oscillations thereby insuring the verticallowering of the .bucket. The guide members 2II secured to the bucket may then accurately engage the guide rail 34 leading through the hatchway 38 to the pit.

The energizing circuit for the lowering switch 8I may be traced from supply line IOI conductor I88, contacts I8I, conductors I82, I83 and 288, contacts or time switch 84, conductors 2I2 and I84, contacts 82 of the slack cable switch, conductors I88 and I88 operating coil of the lowering switch 8i, conductor I81 and I88, contacts I and by conductor I88 to the other supply line I02. As soon as the lowering switch 8i closes, the hoisting motor I8 is energized to lower the bucket into the pit. the lowering relay 82 and the accelerating contactors 84 and 88 are successively operated to short circuit the motor secondary resistors I48 and I44. As the bucket reaches the loading position in the pit, the slack cable switch 8| is operated to open its contacts 82 and to close its contacts 88. The opening oi! the former contacts deenergizes the direction switch 8| while the closing of the latter contacts completes an energizing circuit for the time delay relay 88. This circuit may be traced from the supply line IOI, conductor IIO, contacts 88. conductor III and I24, operating coil of time switch 88 and by conductor I28 to the other supply line I02. As was mentioned above, this time interval is interposed to insure sufilcient time for the loading of the bucket within the pit.

It will be remembered that at this point the present description of the operation was begun. It will therefore be understood that the operations described above are again carried out, and that this cycle of operation will automatically continue as long as may be desired.

By releasing the wedge I3 and by rotating the hand wheel 15 until the pointer 14 indicates IL or the first left-hand silo 24, the cycle of operation will be carried out as described above and the bucket I2 will serve to transport coal or like material into the silo 24. The difierence in the relative adjustment of the trolley limit switches 50, 52,v 83 and 88 with respect to the limit switches BI, 84, 58 and 81 serves merely to cause each switch of the first group to be operated when the bucket reaches the position over the silo 24.

If either of the right- hand silos 28 or 28 should be selected, it becomes necessary to operate the four pole double throw switch 88 to its righthand position. The switch 88 serves to reverse the relative energization of the direction switches 88 and 81 with respect to their former operation so that the bucket I2 will be moved to the right after it comes up from the pit and will be returned to the pit after it has unloaded into one or the other or the selected silos 28 or 28.

Under certain conditions of operation it may be desirable to control the motors I0 and II manually. The transfer from automatic operation to manual control is accomplished by opening the four pole switch 81. The manual operation of my control system is semi-automatic, that is to say, each motion which is carried out by the bucket I2 is controlled by a push button. However, the bucket is stopped automatically at the end of each particular movement or the bucket so that the operator is only required to press a button to initiate the carrying out or a certain fraction of the cycle 01' operation. The sequence relays as before serve to establish the As before, however,

interdependent control circuits so that the bucket l2 may be safely operated through the predetermined cycle.

It will again be assumed that the bucket I2 is at the loading position within the pit and that the control supply lines IOI and I82 are energized as well as the supply lines I88 tor the motors I0 and II. It will also be assumed that the right hand silo 28 has been selected for the cycle of operation. Consequently, the four pole switch 88 will be operated to its right hand position.

with the bucket in the loading position an energizing circuit is completed for the sequence relay 88, which circuit may be traced from the supply line I0 I, conductor IIO, contacts 83 of the slack cable limit switch 8I, conductors III and I I2, trolley limit switch 88, conductor I I3, operating coil I I4 of sequence relay 88, and by conductor III to the other supply line I 02. The sequence relay 88 is thereupon operated to its latched position.

It will be observed that the time relay 8! is energized through a circuit which may be traced from supply line IOI, conductor IIO, contacts 83 o! the slack cable switch 8|, conductors III and I24, operating coil of the time relay 88 and by conductor I28 to the other supply line I02. After a predetermined interval of time the contacts of the time relay 88 are closed, serving to energize the operating coil of the sequence relay 88 through a circuit which may be traced from supply line IOI, conductor IIO, contacts 83 of the slack cable switch, conductors III, I24 and I88, contacts of the time relay 88, conductor I28, operating coil I21 01 the sequence relay 88, and by conductor I28 to the other supply line I02. The sequence relay 88 is thereupon operated to its latched position.

After the operation of the relays 88, 88 and 88 and not before this time, the normally open hoisting push button 220 becomes eflective to complete an energizing circuit for the hoisting switch 80.

It will be assumed that the push button 220 is momentarily depressed to complete an energizing circuit which may be traced from supply line IOI, conductor 22 I, push button switch 220, conductors I38, I31, hoisting switch I38, conductor I88, contacts I3I of the sequence relay 88, conductor I40, operating coil of the hoisting switch 80 and by conductors HI and I42 to the other supply line I02. The hoisting switch 80 is thereupon operated to energize the hoisting motor I0. The relay 83 whose operating coil is connected in parallel with the operating coil of the direction switch is also operated to close its contacts I" to complete a holding circuit for the direction switch 80, which circuit may be traced from supply line IOI, conductor I50, contacts I41 01' relay 83, conductors 222 and I31, hoisting limit switch I38, conductor I38, contacts I3I, conductors I40 and I45, operating coil of the relay 83 and by conductor I48 to the other supply line I02. As before the time delay contacts I48 01 the relay 83 serve to energize the first accelerating contactor 84 which in turn through its time delay contact I88 energizes the second accelerating contactor 88. Consequently, the motor I0 is progressively accelerated from its low speed to its full speed. As soon as the bucket I2 is hoisted to a position above the silos, the limit switch I38 is opened and the limit switch I84 is closed. The opening oi the former switch deenergizes direction switch 80, stoppi the hoisting motor III. The closing of the hoisting limit switch I54 renders the push button 225 eiTective to complete an energizing circuit for the direction switch 86 so that the trolley motor II may be energized in a direction to drive the bucket to the right and towards the selected silo 26. This circuit may be traced from supply line IOI, conductor I56, hoisting limit switch I54, conductor I51, conductor 226, push button 225, conductors I6I and I62, contacts I63 of the sequence relay 90, conductor I64, contacts II8 of sequence relay 89, conductor I65, trolley limit switch 52, conductors I66 and I61, conductor 204, operating coil of direction switch 86 and by conductor I42 to the other supply line I02. A holding circuit for the operating coil of the direction switch 86 is completed by the closing of the contacts 221 operated with the direction switch 86, which circuit may be traced from supply line I0 I, conductor I56, hoisting limit switch I54, conductor I51, contacts 221, conductor 228, switch 98, conductors 229 and I62, contacts I63, conductor I64, contacts I|8, conductor I65, trolley limit switch 52, conductors I66 and I61, switch 98, conductors 204, operating coil of direction switch 86, and by conductor I42 to the other supply line I02.

As soon as the bucket I2 moves toward the silo 26 the trolley limit switch 5| is operated and latched into its closed positions while limit switches 54, 56 and 51 are operated to their open positions. When the bucket I2 has been driven to a position over the selected silo 26, the contacts 50, 53 and 55 of the trolley limit switch 31 are operated and latched'into their closed positions while the switch 52 is opened. The opening of the limit switch 52 deenergizes the direction switch 86 consequently stopping the trolley motor II. As described for the automatic operation of my system, the closing of the trolley limit switch 50'serves to energize the trip coil I13 of the se quence relay 88 which relay is operated to. its unlatched position. After the sequence relay 88 has been tripped, the trip coil I11 of the sequence relay 89 is energized so that this relay is operated to its unlatched position.

The closing of the trolley limit switch 53 completes an energizing circuit for the time delay relay 96 which may be traced from supply line IOI, conductor I10, limit switch 53, conductor I18, operating coil of the time relay 96 and by conductor I19 to the other supply line I02. After a short interval of time the contacts I of the time switch are closed.

The push button 234 is now effective to complete an energizing circuit for the lowering switch 8 I, which circuit may be traced from sup ply line IOI, ,conductor 233, push button 234, conductor I83, contacts I80 of the time relay 96, conductor I84, contacts 92 of the slack cable switch 9|, conductors I and I86, operating coil of the lowering switch 8|, conductors I81 and I88, contacts I30 of sequence relay 88, and by conductor I89 to the other supply line I02. It will be remembered that the operating coil of lowering relay 82 is connected in parallel with the operating coil of the lowering switch 8| by conductors I and I9I. Consequently, the lowering switch 8| and the lowering relay 82 are both operated to their closed positions. The contacts 23I of the relay 82 immediately close to complete the holding circuit for the lowering switch 8|, which circuit may be traced from supply line IOI, conductor I50, contacts 23I, conductors 232 and I83, contacts I80, conductor I84, contacts 92 of the slack cable switch, conductors I85 and I86, operating coil of lowering switch 8|, conductors I81 and I88, contacts I30 and by conductor I89 to the other supply line I02.

After a short interval of time the contacts I92 of the hoisting relay 82 close to'energize the first accelerating contactor 84 which in turn after a short interval of time, energizes by means of its contacts I53 the second accelerating contactor 85. The hoisting motor I0 therefore is accelerated to its full speed.

As soon as the bucket I2 strikes the coal with in the silo, the slack cable switch 9| operates to open its contacts 92 and to close its contacts 93. The opening of the former contacts serve to deenergize the lowering switch 8| and the lowering relay 82, which switches are thereupon operated to their open positions to deenergize the hoisting motor I0.

The closing of the contacts 93 of the slack cable switch 9I completes an energizing circuit for the sequence relay 88 which circuit may be traced from supply line IOI, conductor IIO, contacts 93 of the slack cable switch, conductors III, I24 and I95, contacts I95b of the time switch 96 and by conductors I95c, I26, operating coil I21 of the sequence relay 88 and by conductor I28 to the other supply line I02. The sequence relay 88 is thereby operated and latched into position. The sequence relay 90 is also operated and latched into position by reason of an energizing circuit which may be traced from supply line IOI, conductor IIO, contacts 93 the slack cable switch, conductor III, limit switch 55, conductor I93, operating coil of relay 90 and by conductor I94 to the other supply line I02.

The push button 220 is now effective to complete an energizing circuit for the hoisting switch 80, which circuit may be traced from supply line IOI, conductor 22I, push button 220, conductors I36 and I31, hoisting limit switch I38, conductor I39, contacts I3I, sequence relay 88, conductor I40, operating coil of hoisting switch 80 and by conductors MI and I42 to the other supply line I02. As before the hoisting relay 83 immediately closes its contacts I41, establishing a holding circuit for the operating coil of the hoisting switch 80. After an interval of time the contacts I48 of the hoisting relay close to cause the successive energization of the first and second accelerating contactors 84 and 85 so that the hoisting motor I0 is accelerated to its full speed.

As soon as the bucket I2 reaches the position above the silos, the limit switch I38 is operated to its open position while the limit switch I54 is closed. As before, the opening of the limit switch I38 deenergizes the hoisting switch 80. The closing of the hoisting limit switch I54 renders the push button 235 efiectve for the energization of the trolley direction switch 81. Depressing the push button 235 completes an energizing circuit for this switch which may be traced from supply line IOI, conductor 226, push button 235, conductors I91, I98, contacts I99, conductor 200, contactor II 6 of sequence relay 89, conductor 20I, trolley limit switch 5|, conductor 202, switch 98, conductor I68, operating coil of the direction switch 81 and by conductors I69 and I42 to the other supply line I02. A holding circuit is established for the direction switch 81 by closing of the contacts 238 operated with the direction switch 81, which holding circuit may be traced from supply line IOI, ductor I56, hoisting limit switch I 54, conductor I51, contacts 238, conductor 239, switch 98, conductors 240, 24I and I98, contacts I 99, sequence relay 0., conductor 2". contacts Ill, conductor Ill, trolley limit switch ll, conductor III, switch ll, conductor I, operating coil oi direction switch l1, and by conductors I" and it! to the other supply line I02.

As soon as the trolley motor ll drives the bucket towards the loading pit. the trolley switches l0, ll and I are operated to their open positions while the switch I! is operated to its closed position. When the bucket reaches a position directly over the pit. the trolley switch II is operated to its open position while the switches I, II and II are operated to their closed positions.

As in the case of the automatic operation, the closing oi the trolley limit switch It energizes the trip coil I'll oi the sequence relay .8. while the closing oi the limit switch I! energizes the trip coil oi the sequence relay ll so that both sequence relays are operated to their unlatched positions. As soon as the sequence relay ll closes its contacts Ill, an energizing circuit is completed ior the operating coil oi the time switch 04. Aiter a predetermined interval 01' time, this switch closes its contacts rendering the push button ill eiiective ior initiating the lowering operation oi the bucket II. This circuit may be traced irom supply line llll, conductor 2, push button I", conductors ill, 2", contacts oi the time delay switch 94, conductors Iii and I, contacts 82 oi the slack cable switch 8i, conductors ill and I, operating coil oi direction switch ll, conductors Ill and I, contacts llli oi sequence relay N and by conductor Ill to the other supply line I02. A holding circuit ior the lowering switch ll is again completed by the operation oi the lowering relay 8!, and the accelerating contactors are successiully operated to accelerate the motor I to its iull speed.

As the bucket reaches the loading position in the pit, the slack cable switch 9| is operated to open its contacts '2 and to close its contacts SI. It will be remembered that the opening oi the iormer contacts deenergizes the direction switch ll, while the closing oi the latter contacts completes an energizing circuit ior the time delay relay 9!. At the same time the hoist limit switch Ill is operated to its closed position while the hoisting limit switch I is operated to its open position.

The complete cycle oi operation has again been described and the circuits traced ior the semiautomatic operation oi my system. It will beobserved that a control circuit ior an operation cannot be completed until the previous movement oi the bucket has been completely carried out. That is to say, the energization oi each control circuit is dependent upon the previous control circuit which has been energized and also upon the completion oi the movement oi the bucket. This interlocking oi circuits provides a practically ioolprooi system so that even an unskilled operator may safely operate the coal handling system.

While I have shown a particular embodiment oi my invention, it will be understood oi course that I do not wish to be limited thereto, since many modifications may be made, and I thereiore contemplate by the appended claims to cover any such modifications as tall within the true spirit and scope oi my invention.

What I claim as new and desire to secure by Letters Patent oi the United States, is:

1. An electrically operated system ior a device arranged to be driven through a predetermined cycle oi operations between one position and a selected one oi several positions spaced apart irom said one position, comprising driving means ior said device, a group oi contacts ior controlling the operation oi said driving means, operating means ior said group oi contacts ior operating said contacts, a second group oi contacts ior controlling the operation oi said driving means, operating means ior said second group oi contacts, and an adjustable connecting means between said groups oi contacts ior selecting one oi said several positions ior the carrying out oi said cycle.

2. A material handling system having a carrier arranged to be operated in a predetermined cycle irom a loading station to and irom one oi a pinrality oi unloading stations, means ior driving said carrier. a trolley limit switch having a plurality oi non-adjustable switches ior stopping said carrier over said loading station and a plurality of adjustable switches ior stopping said carrier over an unloading station, and means ior changing the time oi operation oi said latter switches with respect to said iormer switches so that any one oi said unloading stations may be selected ior the carrying out oi said cycle.

3. In combination with a device arranged to be operated in a predetermined cycle along a restricted path irom one position to and irom a selected one oi several other positions, oi motor means ior driving said device, control means responsive to movements oi said device ior controlling said motor means, the said control means including a control element ior stopping said device at said one position and a control element ior stopping said device at a selected one oi said other positions, and adjustable connecting means between said control elements ior changing the time oi operation oi an element so that any one oi said positions can be selected ior the carrying out oi said cycle.

4. In a carrier system having a device arranged to be operated from a loading station to and irom one oi a plurality oi unloading stations, means ior driving said carrier, a limit switch having a set oi contacts ior stopping said device over said loading station and a second set oi contacts ior stopping said carrier over an unloading station, an operating means ior each oi said sets oi contacts, and means ior changing the time oi operation oi said first set oi contacts with respect to said second set oi contacts comprising a driving shait responsive to movements oi said device connected to one oi said operating means, and gears adjustably connecting said other oi said operating means to said one oi said operating means.

5. A material handling system having a carrier arranged to be operated in a predetermined cycle irom a loading station to and irom one oi a plurality oi unloading stations, a motor ior driving said carrier, a trolley limit switch having a plurality oi non-adjustable contacts operated in response to rotation oi said motor ior stopping said carrier over said loading station, a plurality oi adjustable contacts ior stopping said carrier over an unloading station, and means ior changing the time oi operation oi said latter contacts with respect to said iormer contacts comprising a gear for operating said adjustable contacts, a second gear arranged ior rotation with said non-adjustable contacts, a pair oi gears each oi which is arranged in meshing relation with said first and second gears and iriction means ior connecting said pair oi gears together and for permitting the relative adjust ment of said adjustable contacts with respect to said non-adjustable contacts whereby any one of said unloading stations may be selected for the carrying'out of said cycle.

6. In combination with a control system for a device arranged to be operated in a predetermined cycle from a loading station to and from one of a plurality or unloading stations, a trolley limit switch having a plurality of non-adjustable contacts for stopping said carrier at said loading station and a plurality or adjustable contacts for stopping said carrier at an unloading station, each of said contacts comprising a contact member biased to one position, means for holding said member in another position against its bias, and means for operating said member to said one position upon a predetermined movement of said means in said one direction and upon a predetermined movement of said means in the other direction for releasing said member, and means for changing the time of operation of said latter contacts with respect to said former contacts so that any one of said unloading stations may be selected for the carrying out of said cycle.

'I. A material handling system having a carrier arranged to be operated in a predetermined cycle from a loading station to and from one of a plurality of unloading stations, electrical motor means for driving said carrier, a trolley limit switch having a plurality of contacts for stopping said carrier over said loading station, a plurality of contacts for stopping said carrier over an unloading station, means for relatively adjusting said contacts to change the time of operation of said latter contacts with respect to said former contacts so that any one of said unloading stations may be selected for the carrying out of said cycle, a plurality of sequence relays, latching means for each of said relays, a tripping coil for each of said relays for releasing said latch, and an energizing circuit for each of said tripping coils arranged to be completed by said limit switch contacts.

8. A material handling system having a carrier arranged to be operated in a predetermined cycle from a loading station to and from one of a plurality of unloading stations located to the right and to the left of said loading station, a trolley motor for driving said carrier, a trolley limit switch having a plurality of non-adjustable contacts for stopping said carrier over said loading station and a plurality of adjustable contacts for stopping said carrier over an unloading station, means for changing the time of operation of said latter contacts with respect to said former contacts so that any one 01' said unloading stations may be selected for the carrying out of said cycle, and circuit controlling means associated with said trolley limit switch for selectively determining the movement or said carrier to the right or to the left of said loading station.

9. A control system for a device arranged to be operated in a predetermined cycle from one position to and from a selected one of several other positions, comprising a motor for driving said device, a limit switch having two groups of circuit controlling contacts, operating means for each of said groups, means for mechanically connecting the operating means of one group for operation in response to movements of said device, adjustable connecting means for connecting the operating means or said other group to the operating means of said first group so that the operation of said other group with respect to said first group may be varied to select one of said several positions for the carrying out 0! said cycle.

10. An electrical system for driving a device through a selected one of a plurality of predetermined cycles of operations, comprising driving means for said device, a group of circuit controlling devices for controlling the operation of said driving means during a first portion of said cycle, connecting means between said circuit controlling devices and said driving means whereby said circuit controlling devices are actuated by said driving means, a second group of circuit controlling devices for controlling the operation of said driving means during a second portion of said cycle, a second connecting means connecting said second group of circuit controlling devices to said first group whereby said second group is actuated by said driving means, and adjusting means forming a part of said second connecting means for adjusting said second group of controlling devices independently of said first group to select a different second portion for the cycle of operations.

CLYDE H. FREESE.

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