USRE20630E - Electrical control mechanism for - Google Patents

Description

Jan. 18, 1938. H. E. HALLENBECK" Re. 20,630

ELECTRICAL CONTROL MECHANISM FOR TROLLEY BUCKET PLANTS OOOOOQOOOO0.0

ATTORNEYS H. E. HALLENBECK ELECTRICAL CONTROL MECHANISM FOR TROLLEY BUCKET PLANTS Original Filed 001:. 27, 1930 8 Sheets-Sheet 5 .OOOOQOOOOOOO mj' o ATTORNEYS Jan. 18, 193 8. E. HALLENBECK 1161207630 ELECTRICAL CONTROL MECHANISM FOR TROLLEY BUCKET PLANTS Original Filed Oct. 27, 1930 8 Shets-Sheet 5 INVENTOR ELECTRICAL CONTROL MECHANISM FOR TR OLLEY BUCKET PL ANTS Origifial Filed Oct. 2?, 1930 8 Sheets-Sheet s ATTORNEYS Jan. 18, 1938. H. E. HALLENBECK 20,630

ELECTRICAL CONTROL MECHANISM FOR TROLLEY BUCKET PLANTS Original Filed Oct. 27, 1930 8 Sheets-Sheet T Jig/ M22 2 BY a Jan. 18, 1938. H. E. HALLENBECK ,6

ELECTRICAL CONTROL MECHANISM FOR TROLLEY,BUGKET PLANTS Original Filed oct. 27, 1930 s Sheets-SheetB IEVENTQ R ATTORNEYS Reiuued Jan. 18, 1938 ELECTRICAL CONTliOL MECHANISMI FOR.

TROLLEY BUCKET PLANTS Harold E. llallenbeck,

Clinton, N. Y., assignmto Gifford-Wood Company, Hudson, N. Y., a corporation of New York Original No. 2,082,393, dated 1,"... 1, 1937, Serial 1 No. 491,534, October 27, 1930. Application for reissue July 22, 1937, Serial-No. 155,149

48 Claims.

This invention relates to electrically driven' trolley bucket systems, and among other objects, aims to provide a relatively simple and inexpensive electrical control means for such systems, making possible completely automatic operation of the trolley bucket or else hand-controlled operation thereof. Additional objects will be explained in connection with the following description of a preferred embodiment of the invention. In the accompanying drawings forming a part of this specification,

Fig. 1 is a part of a wiring diagram for alternating current, showing some of the connections and apparatus by which the improved results are obtained;

Fig. 2 is the remainder of the alternating cur; rent wiring diagram;

Figs. 3 and 4 are respectively like Figs. 1 and 2, but showing together a direct current diagram;

Fig. is a front elevation, with parts in section, of a typical trolley bucket installation;

Fig. 6 is a vertical section online 6--6 of Fig. 5, but showing the bucket down in the loading ni Fig. 7 is an elevation, on an enlarged scale, of the slack cable limit switch and its actuating means; I

Fig. 8 is a top plan view of the installation of Fig. 5, the machinery. house being shown in horizontal section;

Fig. 9 is an elevation. on an enlarged scale, of

the push button control panel; Fig. 10 is a plan view of a sheave provided with a hoist cable overload cut-out switch and with bucket return switches; I

' Fig. 11 is a front elevation and Fig. 12 is a side elevation of the limit switch actuating mechanism governing the traverse of the bucket. Of recent years, trolley bucket systems have been installed in materials-handling plants because of their flexibility and adaptability, the large economies realized by them, particularly in dispensing with labor, and because they make possible the use of tall storage bins, thus economizing in land area, and making possible a lower capital investment per ton of materials stored. Other advantages of trolley bucket plants as compared with open pit plants operated'by'hand labor are greate'rsafety of operation; less degradation and breakage of lump material; protection from the weather-and hence low cost all year handling of materials; rapidity of truck loading for retail delivery; and freedom from.

bucket installation having all the above mentioned and other advantages, electrical control apparatus which makes possible completely automatic operation of the bucket or semi-automatic operation. The invention provides numerous safety devices and other improvements insuring absolutely perfect operation and control of the bucket, and attaining results'which are impossible in known operator-controlled trolley bucket installations. Referring particularly to the drawings, and first to Figs. 5, 6, and 8, there is shown, for simplicity of illustration, 9. small materials-handling plant, having a series'of storage bins or silos l5, discharge chutes l6 leading from each bin to permit gravity loading of trucks, an elevated track or monorail I1 extending over the bins, a trolley l8 which travels along the track, a bucket i9 suspended from the trolley by means of a hoist line 20, and a trolley or traverse line 2| secured to the trolley toefiect horizontal movement of the bucket beneath the track. One

end of the hoist line is dead-ended as at 22 (Fig. 5 and itpasses over sheave 23 journaled on the trolley and under sheave 25 mounted on bail 26 of the bucket, thence over sheave 24 on the trolley around guiding sheaves 21, 28 and down to a hoist drum 29 (Fig. 6) which is driven by a direct-geared motor 30, either alternating or direct current. To counteract the tendency of the bucket (whether loaded or empty) to spin the hoist drum around, a counterweight 3| (Figs.

5 and 8) is supported by a line 32 guidedby sheaves 33, 34 and leading to the hoist drum but wrapped about. said drum in a direction which is the reverse of the direction in which hoist line 20 is wrapped. Line 32 is dead-ended as at 35 (Fig. 5). r

The ends of the trolley or traverse line 2| are secured to the opposite ends of the trolley, and as shown in Figs. 5 and 8, the line is guided by sheaves 36, 31, 38, 39, 40, and I. and extends down to and-around a. trolleyv drum 42 and also an idler drum 43 (Fig. 6). The trolley drum is directly driven by a motor 44 (either alternating current or direct current) whose controlling mechanisms will be described hereinafter. To keep the trolley line relatively taut and yet permit a momentary yielding, a carriage 45 (Fig. 5) is mounted on the monorail andis connected bya rope 46 with a counterweight 41, ,as disk closed-in the Harding Patent No. 1,631,030 dated May 31, 1927.. Both trolley-and hoist motors,

' together with their control mechanisms, are

shown housed 'in a machinery house H, which aifords protection against the weather.

As the two bucket-controlling lines are independently operated, it will be clear that the bucket'may be raised and lowered at any point desired.

and may be moved tothe right or left at any elevation beneath the track for practically the full length thereof, except for interference with the walls of the bins. Thus the system is adapt able to an infinite number of; arrangements of the bins etc.

The bucket is loaded by gravity from a hopper 48 elevated with respect to the bucket when in loading position. This hopper may be like the one shown in Patent No. 1,720,704 and may be above a pit 49, as in the illustrative plant, or' it may be above the surface of the ground.

. In either case control of the discharge from the hopper to the bucket is had by means of a pivoted gate 50 (Fig. 6) which is shown as being similar to the one disclosed in my Patent No. 1,808,953 assigned to the, assignee of this application. The bucket itself is more fully disclosed in the Bennett Patent No. 1,741,123 dated Dec. 24, 1929. The material being handled'is dumped from a car (not shown) on a railroad siding 5| (Fig, 8) into the hopper 4B, and flows by gravity into the bucket until the latter is filled, when the. flow automatically stops. Then the bucket is hoisted, thus closing the gate 50.

To guide the bucket as it is hoisted, it has pairs of rollers 52 on its opposite sides, each pair engaging between spaced guides or rails 53 extending down in'the pit Ill and upwardly to a point near the tops of the bins. At the upper ends of rails 53, there is preferably a bucket ,.g=uiding and straightening structure 54 (Fig.

6) whioh'i'nsures the proper engagement of the bucketrollers with the rails as the bucket is lowered from the monorail. The structure 54 is fully disclosed in. Patent No. 1,808,954,.dated June 9, 1931.

When the bucket is hoisted as far as the trol ley, its bail 26 engages a spring bufier 55 (Figs.

5 and 6) described in the patent to Towne No.

2,004,451Qassigned to the assignee ofthis case, or else the upper edge of the bucket engages a structure depending from the trolley, as disclosed in Patent No. 1,848,009 dated March 1,

1932. In either case, the bucket is stabilized,

i. e., it 'does not swing through awide are because of its inertia each time the trolley starts up, or because of its momentum each time the trolley is stopped. Such swinging as is induced by changes in velocity'of the trolley is immediately. checked by-the springs of the spring buffer 55.

when the bucket is brought ,over the bin or pile of material in or "on which its contents are tobe dumped, it is lowered until its trip pads 56 (Fig. 5) comein contact with the material, whereupon the bottom opens and the con-' tents flow out by gravity. The bucket is then immediately returned to. the loading point. It is lowered preferably with the bottom still open, and clodng is eflected by contact of the swinging bottom closure or jaw'with an abutment 5'! (Fig. .6) below the gate 4!, as described and claimed in the aforesaid Bennett pat-' cut. The gate is opened by a latch mechanism, as disclosed in my Fatent No, 1,808,953

dated June 9, 1931; but it may be opened auto- "matically by various mechanisms, for example,-

a motor with proper limit switches (not shown) or it may be opened by contact with the bucket cacao itself, as is known to the art of skip hoists.

when the bucket is filled, and the hoist line beginsto pull it up the guides 53, the gate is closed to prevent flow of material into the pit.

The cycle of the bucket, starting from the moment 'of loading, comprises, first, hoisting to the trolley, then a traverse of the trolley either to the-right or left as viewed in Fig. '5, then stopping of the trolley, then lowering of the bucket to the point of discharge, then dumping, then hoisting of the bucket to the trolley,

' then traverse of the trolley in the opposite direction to a point above the guides 53, stopping the trolley,.lowering the bucket to, the filling pointand holding the bucket stationary at that point until full. Obviously, then, there are two hoisting phases, one with'the bucket full. and the other with the bucket empty, two lowering phases, one with the bucket full and the other with it empty, and two traverse phases, one with the bucket full andv the other with it empty. Furthermore, each time the bucket is moved, whether hoisted or lowered or moved with the traverse of the trolley, there must be an acceleration of a heavy but very variable mass followed by a deceleration and stoppage thereof. The operation must be quick to be economical, yet must be smooth lest undue strain be imposed on the cables, cable. connectors,

sheaves, bearings, monorail supports, and other parts of the plant. Furthermore, all possibility of damage to the bucket and trolley must be eliminated. These facts and others known to those skilled in the operation .of trolley bucket systems make the deslderatum of an automatic control of a trolley bucket an extremely difllcult problem, which prior to the present invention, has never been solved. 1

Referring now to Figs. 1 and 2, which show in diagram electrical controlapparatus for three phase alternating current, there are the usual 7 power lines or. mains Ll, L2 and L3 which are connected to or disconnected from the control circuits by a master switch ii, The control circuits are respectively for the hoist motor 30 and the traverse motor M, and sets of fuses BI, 62 protect the two control circuitsagainst surges on the mains.

Considering first the hoist control circuit, there is shown a pair of mechanically interlocked magnetic contactors, the contactor 63 instituting hoisting of the bucket and contactor starting downward movement 'of the same, both contac tors being connected with two of the three conductors 55,-as shown, so that reversing of the hoist motor ll is effected by alternate closing of the contactors.- These contactors are also connected, through conductors ,with a thermal overload relay 61, which protects the motor in case of an excessive load continuing beyond a' certain time interval. Conductors Bl connect the thermal overload relay with the hoist motor (Fig. 2). A motor-mounted solenoid brake having a brake coil 6! effects automatic stoppage of. the hoist motor whenever the current through conductors i8 is cut off, thus stopping'the bucket.

To effect automatic acceleration of the hoist motor so as to minimize strain on the several elements whichcontrol the elevation 01 the bucket, and also to permit a net increase in the speed of hoisting and lowering beyond what is safely possible should the motor be thrown di-f rectly on the line, an accelerating resistor III is connected to the hoist motor by conductors II. As shown in-Flg. 1, two accelerating resistor contactors 12, 13 are connected by conductors I4, 15 respectively with the accelerating resistor HI, these contactors automatically cutting out resistances built in the resistor (not shown) to accelerate the hoist motor, after contactor G3 or 64 closes. As shown, the resistor contactor 12 is in open position, in which all the resistance of the resistor is in series with the secondary circuit of the hoist motor; but as soon as contactor I2 closes, part of the resistance is cut out. A magnetic timing relay switch I6, having a coil 11,

after a predetermined interval, is actuated to and permit full speed operation of the hoist mo-' tor. A conductor 80 connects the relay 16 with timing relays 8| and 82, both with time delay ele-x ments, relay 8i being actuated by an auxiliary contactor 83 which closes with the lowering contactor G4, and relay 82 being actuated by auxiliary. contactor 84 which closes with the hoisting contactor 63. Thus with the closing of either main contactor (63 or 64) a time delay element holds the full resistance of the resistor in circuit momentarily, then part of the resistance is 'cut out and another time delay element holds the remainder of the resistance in circuit for a second or two, and finally all the resistance is cut out and the bucket moves at high speed. Preferably the momentary delay which occurs be fore relay 82 permits contactor 12 to open, permits the slack to be taken out of the hoist rope,

in the hoisting operation.

The described automatic control of the acceleration takes place in both directions of rotation, so that there is a smooth, joltless start of the bucket when being lowered as well as when hoisted. The increase in speed of hoisting which is made possible by the resistor effects a considerable saving, because considerably more material may be handled in the course of a day, yet the wear and tear on the bucket handling apparatus is materially diminished, with the consequences of fewer repairs and shutdowns.

At rare intervals the hoist cable may become kinked and thus catch on a sheave block instead of passing over the sheave, or the bucket or its bail may foul on some projecting part. Any such occurrence would impose a severe strain on the hoist cable,a strain which, if continued might break the cable and allow the bucket to drop with probable injury to the bucket and to the object struck by it. To prevent the possibility of shutdowns and delays due to overloading the hoist cable, a safety or cut out switch 85 (Fig. 2) is connected in series with the holding circuit of the coil Gil of the hoisting contactor 63, as shown, and acts to stop the hoist motor quickly when the overload occurs. A cut out switch which was designed especially for use in the automatic control system of the present application is described and claimed in my Patent No. 1,890,539. As there disclosed, and as shown in Fig. 10 of the accompanying drawings, the switch 85 is carried on a crosstie '85 mounted on sheave frame 86 on which sheave 21' is mounted, the hoist line 20 passing around said sheave. The preferred position of the sheave in a trolley bucket plant is shown in Figs. and 8, but as shown in my abandoned application, Ser. No. 420,483, filed Jan. 13, 1930 the sheave may be positioned elsewhere, for instance, in the position of sheave 28 (Fig. 5). When an excessive tension is imposed on the hoist line, the crosshead accelerated lowering of the bucket.

8'1 is moved in the direction of the pull against the tension of springs 88. The movement of crosshead 81 moves arm 89, whose bent end 90 pushes contact member ill of switch 85 to open said switch.

When the hoist motor has lifted the bucket nearly to the trolley, a limit switch 92 (Fig. 2) is opened, thus opening the up contactor 63 and breaking the hoist motor circuit, so that the solenoid brake quickly stops the motor andthe bucket. Limit switch 92 is one of a set of four hoist limit switches (whose functions are to be described later) all of which may be of the well known traveling nut type, but which herein are actuated by a mechanism similar to that shown in Figs. 11 and 12 and more fully disclosed in the patent to Harding No. 1,867,453, assigned to the assignee of this application; The cam which actuates switch 92 is so adjusted that it brings the bucket to a dead halt at each hoisting operation, whether from the silo or form the pit, when the bucket engages the stabilizer 55 on the trolley. The shock arising from contact between the bucket and the lower end of the stabilizer is absorbed by the stabilizer springs, so that the trolley is protected.

When the bucket is lowered, initially the lowering contactor 64 is closed. The accelerating resistor, with its timing relay control, causes an After this acceleration, the bucket continues down at full speed until nearly at the lower limit of movement, when limit switch 94 opens, in turn opening the down contactor. 64, which opens the motor circuit, thus applying the brake having coil 69 and stopping the bucket (which in the meantime has been closed) directly under the gate 58. In order to hold the bucket under the gate a suflicient length of time to permit loading, a timing relay 95 (Fig. 1) is employed, said relay being started by limit switch 95 (Fig. 2) which is closed as limit switch 94 opens. After a predetermined interval, usually about seven seconds, but varying according to the nature of the material being handled, the contacts of relay 95 close, thus closing the circuit to hoist contactor coil 63 (with which relay 95 is connected by conductor 91), thus closing hoist contactor 83. The contactor 63 and the contacts of relay 85 are held closed by limit switch 92, which, as shown in Figs, 1 and 2, is connected to them by a wire 98. The bucket starts upward, accelerating through the resistor contactors 12, 13, after which it continues at full speed until the limit switch 92 is opened, opening contactor 63, stopthe main switch with a pair of reversing trolley contactors I02, I03, the former controlling travel to the right as the installation is viewed in Figs.

cult of the motor to increase the starting torque.

However, I may use an accelerating resistor like resistor 10, with relay controlled contactors. as heretofore explalnedln connection with the hoist circuits. 7

. To protect the traverse motor against continuing overloads, a thermal overload relay Ill,

which is like overload relay i1, is interposed between conductors I04 and themain contactor I03, breaking the motor circuit after the overload has existedi'or a certain length of time.

As previously stated, when the bucket is stopped at the end of the hoisting operation by opening of the limit switch 32 (Fig. 2), another limit switch I00 is closed. The purpose of this is to complete the circuit to the trolley contactor I02 through the selecting contacor I03,

this being one of two contactors (the other being designated-at I09) for automatically selecting the direction of traverse. By means of its time contact I I0, selecting contactor I08, when closed, will insure the movement 0! the trolley to the right, as viewed in Fig. 5, when the loaded bucket comes up from the pit, while by means of its time contact III, selecting contactor I09, will insure movement of the trolley to the left. It will be observed that time contact H0 is connected with the coil of themain contactor I02 by a wire II2 while time contact III is connected to the coil of main contactor I03 by a wire II3. Thus the coils of these trolley contactors-cannot be excited to close the contactors untiltheir circuits are completed through the time contacts and the wires H2, 3.

When the trolley contactor I02 closes, its auxiliary contact I02 closes, thus completing a circuit through-wires I02, I02 to the traverse brake contactor to be described, and this energizes brake coil I05 to release the brake of the trolley motor. The trolley, with the loaded bucket immediately below it, starts to the right, as viewed in Fig. 5, and continues its traverse until'a limit switch Ill (Fig.2) opens. This opens the selecting contactor I08, with which limit switch II is connected by a wire H5, and the opening of selecting contactor I08 opens main trolley contactor I02, cutting oil the power to the traverse motor.

It has been found highly desirable to permit the trolley to coast for a short time before the brake is applied to the motor to stop the trolley.

This coasting effects a deceleration in the trolley, thus making it .easier for the brake to bring the trolley to a dead stop, and minimizes swinging ofthe bucket in the vertical plane of the trolley when the trolley is finally stopped. Thus there is a much smoother operation, with less wear and tear, and also there is a saving in power, when the trolley coasts before stopping. In actual practice, this coasting may last one second or longer, depending on the speed of the trol1ey,'t he capacity of the bucket, the length of the monorail and other variables.

After this coasting interval, the limit switch IIB (Fig. 2) opens, thus opening the brake contact I" (Fig. 1) which permits the traverse brake I03 to be applied. i

There is a conductor III connecting the main line with the brake coil I06 through brake contactor III. The .magneticcoil IIS, which, when energized, closes the brake contactor H1, is connected by a conductor I20 and an auxiliary gearing, not shown), said sprocket chain being switches Ill and I28 having their actuating arms in the planes of the respective disks, so

- which they are used, and are driven by a reducdirections and to adjust for a short traverse or a long traverse; hence to bring the bucket contactor I2I with a limit switch I22 in series with limit switch IIB (Fig. 2). Limit switch I22 is, however, closed when limit switch Iii is opened, as will be more fully disclosed hereinafter, and hence the opening of limit switch,

H6 is eilective to control the brake contactor II1. Referring to Figs. 11 and 12, which illustrate the preferred form of actuating means for the six traverse switches shown in Fig. 2, there are two cam disks I23, I23 having cams I25 on their peripheries, said disks'belng slowly driven by a common shaft I20 which in turn is driven by a sprocket chain I21 (through a reduction connected with the idler drum 43 (Fig. 8) of the traverse unit. The particular construction of this actuating means for the traverse limit switches is fully "disclosed in the aforesaid patent of H. V. Harding, No. 1,867,453. The limit switches Ill, IIG, I22, I23, I29, and I30 are placed adjacent the disks I23, I23, with that the cams I23 will depress the actuatin arms, thereby opening the control circuits governed by the limit switches. The disks are adjusted to suit the particular installation with tion gearing of such ratio that the disks are rotated less than one full revolution during the entire traverse of the trolley. Each cam I25 governs traverse movement of the trolley in one direction only, the two disks rotating in opposite directions as the trolley travels in opposite directions. Obviously, by adjusting the angular positions of the cams I25 it is possible to govern the traverse of the trolley in both to a stop directly over any one of a series of bins or piles of material.

As previously stated, limit switch Ill merely effects cutting off of power to the traverse motor (the same being true of the corresponding switch I28); stoppage is not effected until the brake contactor III, which is governed by limit switch IIB, breaks the circuit of the brake coil I00. To open limit switch IIB, and the corresponding limit switch I22, there are two cam arms I3I secured to the disks I23, I24 adjacent their peripheries and extending substantially at right angles to the fiat faces of the disks or parallel to the shaft I26. These cam arms may have pins at their ends inserted in one of a series of holes I32 drilled in the sides of the cams I23 and secured as by nuts I33. Each cam arm I3I depresses the actuating arms of two limit switches IIB, I20 or I22, I30, as the fected by switches IIS and I22. As will be explained,'swltches I 23' and I30 govern the operation of the direction-selecting contactors I03, I03 respectively.

In the above description of the arrangement and operation of the parts, the hoisting and when the trolley and loweringof the bucket between the monorail Before starting the lowering operation, a slight pause should occur, to insure a stationary buckthe aforesaid Towne application.

et. when the trolley stops, even after a period of coasting, the bucket tends to go on, because of its momentum, and hence its sheave 25 tends to climb the hoist line 20, by which the bucket is suspended. This tendency of the bucket to swing on the hoist line much like a short pendulum is strongly resisted by the powerful springs of the stabilizer 55, as fully explained in The stabilizer cannot -act instantaneously, however, and a brief interval must be allowed for the bucket to become still before lowering may begin, because if a swinging bucket were lowered, it might be dashed against the bin or some other obstacle as the pendulum" lengthened. The present invention provides means for effecting a brief pause before lowering begins. a

As previously explained, limit switch I29 is actuated with limit switch IIG governing the traverse brake. However, limit switch I29 is closed when switch I16 is opened, and this closing effects closing of selecting contactor I09,

closes a contactor I35 (Fig. 1) which has a time 3 element contact. When this time contact closes, after an interval of two or three seconds, the

lowering contactor 64 is closed, due-to the conductor I38, and the hoist motor starts lowering the bucket with automatic acceleration as pre- .viously described) until its trip pads strike the pileof material or the bottom of, the bin or the ground- When some of the weight of the bucket is taken off the hoist cable, a bucket return device, to be described, will operate, to effect a reversal of the motor with consequent hoisting of the bucket. This reversal of the hoi t motor may take place rapidly with an alternatingcurrent motor of a known type, without the least injury, and is much to be desired, not only to save time, but also to obviate trouble arising from a slack cable, as more fully ex plaihed in my Patent No. 1,890,539.

Referring to Fig. 2, two switches I31, I38 are shown diagrammatically, with connections such that switch I31 controls lowering of the bucket and switch I38 controls hoisting, as will-be explained. The switches I37, I30 are preferably on the sheave frame 86 (Fig. 10) and the arrange- -ment is such that when the hoist line slackens somewhat, the sheave frame moves relative to crcs shead I39 so that the latter strikes the contact element I38 of switch I38 to close said switch, .while switch I31 is allowed to open, be-- cause of its movement away from crosshead I39. The crening of limit switch I3I opens the lowering contactcr 64, while the closing of switch I30 closes the hoisting. contactor 63, thus stopping the downward movement of the bucket and starting the upward movement.

bucket again reaches the trolley, the limit switch above.

the Way of the gate chute.

When the.

s: of the hoist unit opens, opening the hoisting contactor 03, which eflects braking of the hoist motor and stoppage of the bucket.

With the bucket stopped at the upper limit of its travel, the limit switch I on the hoist unit then closes, closing the trolley contactor I03 through the selecting contactor I09, which was closed in a previous operation, as explained The bucket now. travels to the left, as viewed in Pig. 5, until the limit switch I28 (Fig. 2) on the traverse unit opens the trolley contactor I03, permitting coasting for about one second, followed by opening of limit switch I22 (Fig. 2) which opens the brake contactor II'I, causing the brake to stop the traverse motor and hence the bucket. Traverse to the left ceases, and there is a predetermined pause, with the bucket above the bucket straightening device 54 (Figs. 5 and 6) before the bucket is lowered. When limit switch I22 opens, limit switch I30 closes, thus closing the selecting contaotor I 08, and thereby preparing for the next traverse of the bucket, which will ordinarily be to the right. The opening of brake contaotor II1 again closes timing relay I35, which after the predetermined interval of two or three seconds closes the down contactor 64, so that the bucket is lowered down the guides 53, being automatically accelerated and finally brought to a stop, as previously explained, to take on another load.

Referring to Fig. '7, there is shown a slack cable device actuated when considerable slack occurs in the hoist cable to open a switch I40 to cut off the power to the hoist motor. The

connections of switch I40 are shown in Fig. 2,

said switch being, in series with the hoist limit switch 94, which, as explained, opens the lowering contactor 64, thus opening the circuit of the hoist motor. The purpose of switch I is to I make impossible an excessive amount of slack hoist cable, which is likely to foul on various objects, and be broken when drawn taut, thus letting the bucket fall and shutting down the entire plant.' The bucket return device shown in Fig. 10 acts to prevent slack when the bucket is down inbin or on top of a pile but is rendered inoperative, by means to be described, when the bucket is in the pit, as it is then desirable that the hoist cable be sufficiently slack to let the hail of the bucket swing down out of See Fig. 6. The slack cable device of Fig. 7 is a safety device, operating independently of the remainder of the mechanism to stop the hoist motor should excessive slack accumulate in the hoist cable; and it is described and claimed in Patent No.

1,848,972 dated March 8, 1932-.

Referring to Figs.'6 and '7, the hoist drum 29 has a base I, and pivoted on said base is a frame I42 carrying a sheave I43 at its upper end, a counterweight 44 on the other end of frame I42 holding the sheave in engagement with the hoist line 20. If the hoist line slackens, the counterweight swings frame I42 clockwise, as viewed in Fig. 7, thus raising an adjustable angle piece I45 which normally presses down on a spring-pressed plunger I46 which operates switch I40. When the plunger I46 is allowed to move upwardly, responsive to its spring (not shown) switch I40 opens the circuit of the hoist motor. A moderately taut hoist line will, however, malintain switch I40 closed because of the position in which frame I42 is held. The sheave I43 is' always maintained in contact with the I 42 and it travels back and forth along shaft I43! as'thehoist line is wound upon or unwound from the drum 29.

The aforementioned means to render the bucket return device inoperative while the bucket is in the pit is shown diagrammatically inFig. 2. A-

switch I41 is connected by conductors I with the limit switches I31, I38 and has an operating arm I40 with a roller I on its free end. The switch I I! is placed on or adjacent to the monorail in the path of a tripper I49? on the. trolley (Fig. 5) and is located above the bucket guides- 53 so that while the trolley is in position to lower the bucket upon the guides, the tripper I49 engages roller I 50, thus holding switch lll in position to cutout switches I31, I30. r

To prevent lowering of the bucket while either traversing contactor I02, I03 is closed, and to prevent traversing oi the bucket while either the up or down contactor is closed, electrical interlocks are provided. Referring to Fig. 1, the traverse contactors have auxiliary contacts I51, I52, which are connected in series with wire I53 leading from down contactor coil 64. The auxiliary contacts I5I, I52 each open when the corresponding traverse contactor closes, and each closes upon opening of the corresponding traverse contactor. The object of this apparatus is to prevent the down contactor coil fromlbeing energized as long as either traverse contactor is closed. In the same manner, auxiliary contacts I54, I55 are connected in series with wire I56 leading from both traverse contactor coils I02,

I03, thus preventingieither traverse contactor from closing as long as either contactor 63, 64 is closed. Auxiliary contact I54 also prevents the down, contactor 54 from. closing while the up. contactor 63 is closed.

One 01' theobjectsoi the invention is to provide a control for electrically driven trolley buckets which may beeither completely automatic or under the direct control of the operator, and a more specific object is to provide very simple means to change from automatic to hand operation and back again. The preferred form of con: trol panel I51 is shown in Fig. 9 and comprises six push buttons Iii-I63 and two toggle switches I64, I55. The wiring and connections for the several switches are shown in Fig. 2. When the switch I05 is at 'run position, the apparatus willoperate, but when it is at safe" position, nothing will move, however the apparatus is handled. When the switch IE4 is movedtoward the position designated by theword "hand, control of the bucket is eifected by pressing the switches I58-I53 in the order necessary to move the bucket wheredesired. The operator may thus effect step-by-step operation of the bucket, which continues its traveluntilstopped by traverse stop switch IE0 or hoist stop switch I63 or by one of the safety switches. It is thus necessary to press one of the buttons 458483 for each hoisting, lowering and traversing operation. But

when the switch IE4 is moved to the automatic position, the bucket operates automatically and i continuously without any further attention whatever.

The above described embodiment of the invention can be employed only when the source of poweris threephase alternating current, which, however, is almost universally availablethroughout the United States. In some of the older industrial .centers,'direct current electric power is supplied incertain restricted localities to the r I exclusion of alternating current. Hence it has augmentingthe braking action.

. cacao been found necessary to devise a direct current control system functionally the equivalent of the alternating current control system of Figs. 1 and 2. A direct current 'diagram embodying my invention is clearly shown in Figs. 3 and 4, which correspond to Figs. 1 and 2. respectively.

' In Fig. 3, there is shown a main line 200, a feeding switch MI, and fuses 202 and 203- protecting the motor circuits including conductors 204. There is also a main line contactor 205 which carries the auxiliary contacts 205 and 201.,

This contactor is used in connection with the reversing hoist contactors to be described and operates simultaneously with either contactor, its function being to break the main line circuit on the line side of the reversing contactors.

The hoisting and lowering of the bucket is controlled through four single pole contactors, the contactors 208 and 205 controlling-the hoisting movement and the contactors 2I0 and 2 conx trolling the lowering movement.

Each of the main contactors 208-2 has two auxiliary contacts as shown, these being designated bythe same reference numerals with" the letters a and b added. In order to provide for an accelera- I tion. of the bucket both in hoisting and lowering, there are two 'acccleratingrel'ays 2I2, 2I3 which control the time intervals of the closing of the two acceleratingcontactors 2 I4, 2I5, respectively, which cut in or cut out all of .the resistor R.

In stopping the direct current motor, countervoltage is set up, as is well known. In order to prevent reversing oi the hoist motor before its 'countervoltage dies down, a time relay 2IB is provided.

at 2 I1 and its auxiliary contacts at. 2Ila and 2I'Ib. The time relay for controlling the interval during which the bucket is held stationary before lowering is shown at 2I0. I

The traverse motor is controlled by two double pole contactors 2| 9, 220, each having three auxiliary contacts H9, H9", 2l9 and 220", 220", 220 The selecting contactors for controlling the direc tion of traverse are shown at HI and 222. Each has three auxiliary contacts, as shown. To accelerate the traverse motor. there is an accelerating contactor 223 and an accelerating relay 224,'a resistor R being cut in by the contactor 223 when the traverse motor starts and being automatically cut out after a predetermined interval through the action of the relay 224. A traverse brake contactor 225 with auxiliary contacts 225", 225 is also provided'to control the setting ofthe traverse brake which occurs after an interval of coasting, as previously explained. Overload protection to as the fuses 202 and 203.

Cooperating with the solenoid brake for the hoist motor is a dynamic brake resistor R2 which is cut in and cut out by means of auxiliary contact 201 on the main line contactor 205. The resistor R2 is short-circuited across the armature of the hoist motor whenever the line contactor opens, and stops the motor very quickly, greatly Referring now to Fig. 4, it is seen that the apparatus shown is much the same as the parts illustrated in Fig. 2 and hence very little additional description is necessary, particularly in view of the explanatory legends in the figure. The operating panel is arranged as in Fig. 2 and the various limit switches, as well as the cut-out switch and hoist cable overload switch perform The timing relay for holding the bucketin the pit while taking on a load is shown the same functions in the same way as the parts described in the alternating system.

While I have shown diagrams suitable only for three phase alternating current and for direct current, it is within the scope of my invention to wire the apparatus for operating and controlling the trolley bucket so as to operate on single phase or two phase alternating current.

The described apparatus makes it possible for a single operatorto initiate automatic operation of a trolley bucket plant and thereafter to attend to other duties, if. he desires. All major and most minor operating troubles are eliminated by the apparatus described in this application. The invention provides an automatic trolley bucket system which has been proved to be highly reliable and smooth in operation.

Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations. i

What I claim is:-

1. An electrical control system for traversing hoists having a material carrier comprising, in combination, a. hoist motor; a slowly driven hoist limit switch actuator; a traverse motor; a slowly driven traverse limit switch actuator: primary circuits for the hoist and traverse motors; a switch or controlling automatic operation; a set oi six limit switches operated by the traverse limit switch actuator, two of which control the limits of the traverse motion, two of which control a slowing down of the traverse motor before the limits of the traverse motion in either direction are reached, and the remaining two of which control the selecting of the direction of traverse; a set of fourlimlt swltches operated by the hoist limit switch actuator. two of which control the limits of hoisting and lowering, one oi which controls the period of rest while the material carrier is loaded, and one of which interlocks electrically the traverse. and hoisting motions; so that traversing cannot begin until the hoisting limit has been reached: electromagnetic contactors and control circuits controlled by and connected with said sets of limit switches also connected to said motors, so that the hoisting, lowering, stopping and traversing are controlled entirely automatically, once said automatic control switch has been closed.

2. An electrical control system for traversing hoists having a material carrier comprising, in

combination, a hoist motor; a traverse motor; a

'hoist motor circuit; a traverse motor circuit; a

controlled by and connected with said sets of limit switches to control the hoisting, lowering and traversing entirely automatically, without any attention from the operator; means driven at slow speed by the hoist motor for actuating the four hoist limit switches; and means driven at slowspeed by the traverse motor for actuating the four traverse limit switches.

3. An electrical control system for traversing hoists comprising, in combination, a hoist mo tor and circuit therefor; a traverse motor and circuit therefor; a set of switches connected in the traverse motor circuit for governing the traverse motions; a set of switches connected in the hoist motor circuit for governing the hoist and lowering motions; electromagnetic contactors and auxiliary circuits controlled thereby and connected with said sets of switches to control the hoisting, lowering and traversing entirely automatically, without any attention from the operator; a manually operable switch and a circult controlledby said switch and so connected to the hoist and traverse circuits as to change the operation from a completely automatic one to an operator-controlled one: and manually operable switches for hand control of the system comprising a switch to stop traverse, two switches to initiate traverse respectively in upposite directions, a switch to stop hoisting, two switches to control respectively up and down movements of the material carrier; and a safety switch connected into the hoist and traverse circuits to shut off the power from all the circults. I

4. A fully automatic electrically operated trolley bucket system comprising, in combination, a bucket; a hoist rope; a trolley from which the bucket is suspended by the hoist rope; a trolley rope; means to support the trolley for the traverse; traverse and hoist motors; circuits for said motors; control circuits having more thantwo control switches for the traverse motor circuit; control circuits having control switches for the hoist motor circuit; means slowly driven by the traverse motor for actuating the control switches for the traverse motor; and means slow ly driven by the hoist motor for actuating the control switches for the hoist motor; two of said traverse control switches being-connected so as to effect coasting of the trolley in opposite directions with the power cut oil prior to stopping.

5. A trolley bucket installation comprising, in combination, a hoist line; a trolley line; a. trolley traversed by reciprocation of the trolley line;

a dumping bucket raised and lowered from the I trolley by the hoist line; a hoist line drum; a reversible electric motor for driving said hoist drum; a. trolley line drum; a reversible electric motor for driving said trolley drum; and electrical control circuits for governing the two motors, said circuits having a switch which, when closed. starts the bucket through its cycle: said circuits being so connected and arranged as to efiect automatically and continuously descent of the bucket for loading, then hoisting of the bucket to the trolley, then traverse of the trolley, then then hoisting of the bucket to the trolley, and then traverse of the trolley back to the point where lowering is to take place for the succeeding load; and interlocking circuits so connecting th hoist and traverse motor circuits as to make lowering of the bucket for discharge of its load.

motor for driving said trolley drum; and electrical control circuits for governing the two motors, said circuits having a switch which, when closed, starts the bucket through its cycle; said circuits being so connected and arranged as to effect automatically and continuously descent of the bucket for loading, then hoisting of the bucket to the trolley, then traverse of the trolley, then lowering of the bucket for discharge 01' its load, then hoisting oi the bucket to the trolley, and

then traverse of the trolley back to the point where lowering is to take place for the succeeding load; said switch being so connected in the circuits that, when opened, automatic operation ceases; and a plurality of switches also connected in said circuits each to eiiect one of the specified steps of hoisting, lowering and traversing in opposite directions.

7. A trolley bucket installation comprising, in combination, a hoist line; a trolley line; a trolley traversed by reciprocation oi the trolley line; a dumping bucket raised and lowered from the trolley by the hoist line; a hoist line drum; a

reversible electric motor for driving said hoist line; a trolley line drum; a reversible electric motor for driving said trolley drum; and electrical control circuits for governing the two motors, said circuits having a switch which, when closed, initiates automatic and continuous operation of the bucket including descent for loading, then hoisting oi the loaded bucket to the trolley, then traverse of the trolley, then lowering of the bucket for discharge of its load, then hoisting of the empty bucket to the trolley, and then traverse of the trolley back to the point where lowering is to take place for the succeeding load; said switch being so connected in the circuits that,

when opened, automatic operation ceases and hand control is then permitted; a plurality of hand-operated switches also connected in said circuits each to efiect one'of the specified steps of hoisting, lowering, and traversing in opposite directions; and a. safety switch disconnecting the control circuits when in one position to stop op eration and connecting them when in another position; the control circuits being so connected with the safety switch that when the operation stops, because of said safety switch, the bucket cycle is not changed and automatic operation resumes from the point at which it was stopped, when said safety switchis moved to said other position.

8. An electrical control system for trolley buckets of the gravity dumping type comprising,

in combination, a hoist control circuit having a time delay element for holding the bucket in loading position tor a predetermined interval; said time delay element being adjustable relative to the hoistcontrol circuit to vary the interval allowed for loading without varying the operation of the bucket in any other part of the cycle of operation; means for hoisting the bucket and so connected as to operate only when the aforesaid time interval has elapsed; means for stopping hoisting when the bucket reaches the trolley; means for effecting traverse of the trolley after hoisting has ceased; means for stopping the traversing trolley; means for lowering the bucket after traverse has ceased; hoist-,line-operated means for stopping the lowering and ef fecting immediate hoisting of the bucket when it reaches the point of discharge; means for eifecting traverse of the trolley in the opposite direction; means for stopping the trolley prior 2 to lowering of the bucket; and means for lower- 7 ing the bucket to the point 01 loading.

9. An electrical, control system for trolley buckets of the gravity dumping type, comprising, in combination, a hoist line for supporting the bucket; a trolley supporting said hoist line and adapted to traverse in opposite directions; a reto cut out the action of said bucket-reversing means when the bucket is being lowered empty for refilling.

10. An electrical control system for trolley buckets of the gravity dumping type comprising, in combination, a reversible motor for hoisting the bucket; means for stopping the hoist motor at the end oi. each hoisting operation; a reversible motor for traversing the bucket when hoisted; means for stopping the traverse motor at the end of each traverse; control circuits for the traverse motor having switches effecting cutting off the power to the traverse motor before the bucket reaches. its stopping point, to permit coasting oi the bucket; means for lowering as soon as traversing ceases; and means ,for reversing the hoist motor as soon as the bucket has encountered an obstruction while lowering,

thus lessening the tension in the hoist line, said reversing means acting instantaneously to prevent slackening of the hoist line.

11. An electrical control system for trolley buckets of the gravity dumping type, comprising, in combination, a reversible motor for hoisting the bucket; automatic accelerating means connected in the hoist motor circuit and including magnetic switches acting during hoisting,

and also during lowering by the reversed motor;

a limit switchfor stopping the hoist motortat the end of each hoisting operation; a reversible motor for traversing the bucket when hoisted;

a limit switch for stopping the traverse motor at the end of each traverse; control circuits for the traverse motor having switches effecting cutting off the power to the traverse motor before the bucket reaches its stopping point, to permit coasting of the bucket; and means for reversing the hoist motor as soon as the bucket has encountered an obstruction while lowering, thus lessening the tension in the hoist line, said reversing means acting instantaneously to prevent slackening of the hoist line.

12. A trolley bucket installation comprising,

in combination, a hoist drum; a hoist line wound around said drum; a reversible motor for driving said hoist drum; a traverse drum; a traverse line 'wound ,around said traverse drum; .a reversible motor for driving said traverse drum; a trolley to which said traverse line'is secured; a gravity dumping bucket suspended by the hoist line from the trolley; mechanism actuated by the lessening of tension on the hoist line when the bucket is lowered into contact with a pile of material to operate a swltch;.a circuit controlled by said switch to reverse the hoist motor and thereby to start the bucket up again; and means to cut out the action of said switch whenthe bucket is lowered to the loading point.

13. A trolley bucket installation comprising, in combination, a hoist drum; a hoist line wound around said drum; a reversible motor for driving said hoist drum; a traverse drum; 9. traverse line wound around said traverse drum; a reversible motor for driving said traverse drum; a. trolley to which said traverse line is secured: a gravity dumping bucket suspended by the hoist line from the trolley; mechanism actuated by the lessening of tension on the .hoist line when the bucket is lowered into contact with a pile of material to operate a switch; a circuit controlled by said switch to reverse the hoist motor and thereby to start the bucket up again; a switch located adjacent the point where the trolley stops to permit lowering of the bucket to the loading point; and a switch-operating shoe fixed to the trolley and moving said last named switch went out the bucket-reversing switch as long as the trolley remains at the aforesaid point.

14. In an electrical trolley bucket installation, the combination of automatic electrical means for raising, lowering and traversing the bucket through a complete operative cycle to e'ifect loading, discharge of load, and return to the original loading point; operator-controlled means for predetermining in which one of two directions from the loading station traverse of the bucket will take place; and automatically acting means to hold the bucket at the loading point for a predetermined time interval so that loading may be completed before the hoisting is resumed.

15. In an electrical trolley bucket installation,

the combination of automatic electrical means for raising, lowering and traversing the bucket through a complete operative cycle to eifect loading, discharge of load, and return to the original loading' point; means for predetermining in which one oi two directions from the loading station traverse of the bucket will take place; means for effecting a pause in the operation at the end of each traverse of the bucket and before lowering the bucket, whether empty or full; and automatically acting means to hold the bucket at the loading point for a predetermined time interval so that loading may be completed before the hoisting is resumed.

16. In an electrical trolley bucket installation, the combination of automatic electrical means for raising, lowering and traversing the bucket through a complete operative cycle to effect loading, discharge of load, and return to the original loading point; operator-controlled 'means for selecting the direction of movement of traverse of the bucket before the bucket starts on its cycle, so that traverse in either direction, and return-traverse, are predetermined and fully automatic; and electrical interlocking circuits so connected and arranged as to prevent hoisting or lowering of the bucket while traversing takes place, and also to prevent traversing when the bucket is lowered from the trolley.

17. A trolley bucket installation comprising in combination, a hoist motor; a hoist line; a

trolley; a trolley motor; a trolley line; a bucket suspended from the trolley by the hoist line; both motors being" reversible to effect movement of the bucket in opposite directions,

by means of the lines; electrical circuits for the hoist and trolley motors to effect automatic operation of the bucket; and electrical interoperator-controlled locking circuits connecting the. hoist and trolley motor circuits to prevent traversing of the bucket when lowered from the trolley and to prevent hoisting or lowering while traversing.

18. In an electric motor-operated trolley bucket installation, the combination of a bucket; a trolley; a trolley motor; a solenoid brake for the trolley motor; a trolley line for traversing the trolley in opposite directions; a hoist motor; a hoist line supported by the trolley for raising and lowering the bucket; a plurality of traverse limit switches connected in the control circuit of the trolley motor; a mechanically driven limit switch actuator having adjustment means for varying the points at which actuation of said switches takes place, in opposite directions of traverse; two of the limit switches cutting oi! power to the trolley motor, respectively in opposite directions of traverse; two other limit switches effecting application of the brake, respectively in opposite directions of traverse; said actuator being so constructed and arranged that when adjusted for varying travel of 'the bucket, the time relation of the aforesaid limit switches for cutting ofi power and stopping the trolley is not changed.

19. An electrical control system for automatically and continuously hoisting, traversing, lowering, hoisting, return traversing, and again lowering a bucket which is controlled by two lines, operated by two reversible motors; said system having primary and control circuits for the two motors and a switch which, when closed against certain contacts, starts automatic operation; said switch, when closed against other contacts, changing the control'circuits to permit hand-controlled operation; hand-operated switches for controlling each hoisting, lowering and traversing motion of the bucket; the circuits of said switches being so connected and arranged that when the first-named switch is moved for hand-controlled operation while auto matic operation is taking place, the bucket continues its traverse or its ascent or descent until said traverse or ascent or descent ends, and then comes to a full stop and remains stationary until hand operated for each distinct phase of the operating cycle, or until automatic operation is resumed by moving the first-named switch for such operation.

20. A trolley bucket installation comprising, in combination, a hoist line; trolley line; a trolley traversed by reciprocation oi the trolley line; a dumping bucket raised and lowered from the trolley by the hoist line; a hoist line drum; a reversible electric motor for driving said hoist drum; a trolley line drum; areversible electric motor for driving said trolley drum; and electrical control circuits for governing the two motors, said' circuits having a switch which, when closed, initiates automatic and continuous operation of the bucket including descent for load -circuits when in one position to stop operation and connecting them when in another position to permit operation; the control circuits being so connected with the safety switch that when bucket installation of the two motor, gravity the operation stops, because of said safety switch, the bucket cycle is not changed and automatic operation resumes from the point at which it was stopped,wwhen said safety switch is moved to said other position; the control circuits being so arranged and actuated that'retrograde traverse of the bucket cannot take place when automatic operation is resumed, and traverse in the proper direction will always take place.

21. An automatic, electrically operated trolley permit hand operation; manual control switches for effecting hoisting, lowering and traverse in either direction; the switches and control circuits being so arranged that when automatic operation is stopped because of said safety, switch, and later automatic operation is desired to be resumed, said safety switch need only be thrown to running position, and the bucket will resume operation in the proper direction from the point at which it had been stopped.

22. A trolley bucket installation comprising, in combination, a hoist line; a trolley line; a trolley moved in opposite directions by the trolley line; a dumping bucket raised and lowered from the trolley by the hoist line; a hoist line drum; a reversible electric motor for driving said hoist drum; a trolley line drum; a reversible electric motor for driving said trolley drum; electrical control circuits for governing the two motors, said circuits having a' switch which, when closed, permits completely automatic operation of the bucket through its entire operating cycle; said switch being so connected in the circuits that, when opened, automatic operation ceases and hand control of both motors is permitted; hand control switches in the control circuits permitting the starting of the bucket in any desired phase of its cycle and in any desired direction; the circuits being soarranged that the bucket, when started inone direction by one of the hand control switches, continues its movement in the same direction when the switch controlling automatic operation is thrown to automatic operation position. and completes its cycle in the proper sequence of operation and continuously repeats said cycle 7 unless stopped by the operator.

2a. In a two-line-controlled trolley buck t installation having reversible hoist and traverse motors for operating the lines, the combination of primary motor circuits; secondary control cir-- cuits connected with the primary circuits; me chanically actuated switches controlling the secondary circuits; interlocking circuitsv connecting the primary circuits so that traversing while hoisting and lowering while traversing are made impossible; adjustable means mechanically connectlng the aforesaid switches respectively with the hoist and traverse motors, so that the control circuits govern the primary circuits accordimpossible; adjustable means mechanically contraversing, lowering, hoisting, return-traversing and lowering of the bucket; and a switch conmeans to vary the time interval during which taneous reversal of the hoist motor; and a switch vrelay only after a predetermined time interval,

- rest at the end of said lowering operation, to

operation, followed 'byinstantaneous reversal oi.

ing toa predetermined and operator-adjusted cycle, thereby to effect automatically hoisting, traversing, lowering, hoisting, return-traversing and lowering of the bucket; and a switch connected in the circuits to initiate automatic operation.

24. In a two line-controlled trolley bucket installation having reversible hoist and traverse motors for operating the lines, the combination of primary motor circuits; secondary control circuits connected with the primary circuits; mechanically actuated switches controlling the secondary circuits; interlocking circuits connecting the primary circuits so that traversing while hoisting and lowering while traversing are made necting the aforesaid switches respectively with the hoist and traverse motors, so that the control circuits govern the primary circuits according to a predetermined and operator-adjusted cycle, thereby to effect automatically hoisting,

nected in the circuits to initiate automatic operation, said switch having contacts so connected that when it is moved to close them, hand operation of the'bucket is permitted; a series of switches connected in the control circuits to govern manually traverse, hoisting and lowering of the bucket; and a safety switch connected in the circuits so that when moved one way, all operation immediately ceases, and when moved another way either hand or automatic operation is permitted. a

25. In a two line-controlled trolley bucket installation having reversible hoist and traverse motors for operating the lines, the combination of primary motor circuits; secondary control circuits connected with the primary circuits for automatic operation of the trolley bucket; interlocking circuits connecting the primary circuits sothat traversing while-hoisting and lowering while traversing are made impossible; adjustable means forming a part of the control circuits to eifect a stopping of the bucket at the end of one lowering operation; manually adjustable the bucket is at rest while at the end of said lowering operation; switch means connected into the control circuits and effecting stopping of the other lowering operation, followed by instanconnected in the circuits to initiate automatic operation.

26. In a two line-controlled trolley bucket installation having reversible hoist and traverse motors for operating the lines, the combination of primary motor circuits; secondary control circuits connected with the primary circuits for automatic operation of the trolley bucket; interlocking circuits connecting the primary circuits so that traversing while hoisting and lowering while traversing are made impossible; adjustable means forming a part of the control circuits to effect a stopping of the bucket at the end of one lowering operation; a time relay connected in with the control circuits and having an adjustable member to effect closing of the whereby to eifect a delay, with the bucket at permit complete gravityloading of the bucket;

switch means connected into the control circuits and eli'ectlng stopping of the other lowering the hoist motor; and a switch connected in the circuits to initiate, automatic operation.

27. In combination with a trolley, and a trolley line for traversing the trolley in opposite directions along a track; a trolley drum for driving the trolley line; a reversible motor driving the trolley drum; 9. motor circuit; switch-actuating means mechanically driven at slow speed by the trolley motor; limit switches connected in the motor circuit; members carried by a movable part of said switch-actuating means and each being adjustable in position with respect to said movable part, and engageable with said limit switches to step traverse of the trolley in opposite directions; the amount of traverse being varied by the adjusted positions of said mem-- bers; and direction-selecting switches and circuits connecting them with the traverse motor circuit, said direction-selecting switch being adjacent to the limit switches and being actuated by the same members which actuate said limit switches.

28. In combination with a trolley, and a trolley line for traversing the trolley in opposite directions along a track; a trolley drum for driving the trolley line; a reversible motor driving the trolley drum; a motor circuit; switch-actuating means mechanically driven at slow speed by the trolley motor; limit switches connected in the motor circuit; members carried by a movable part of said switch-actuating means and each being adjustable in position with respect to said movable part, and engageable with said limit switches to stop traverse of the trolley in opposite directions; the amount of traverse being caried by the adjusted positions of said members; direction-selecting switches and circuits connecting them with the motor circuit, said direction-selecting switches being actuated by the switch actuating means; the circuits connecting the direction-selecting switches and the limit switches with the motor circuits being so connected and interlocked that the setting of the'ai'oresaid adiustable members to effect traverse of the trolley in either direction from a fixed point to a predetermined point on the track also adjusts the setting for the direction-selecting switches so that the proper direction of traverse from the fixed point is determined.

29. A traversing-hoist comprising, in combination, a trolley; a track along which the trolley moves; a material carrier suspended from the trolley by a hoist line; a hoist'drum and a motor driving said drum; a trolley line; a trolley drum for'driving the trolley line; a reversible motor driving the trolley drum; primary and control circuitsior the two motors; switch-actuating means mechanically driven at slow speed by the trolley motor; limit switches connected in the trolley motor circuit; member's carried by a 'movable part of said switch-actuating means and each being adjustable in position with respect to said movable part, and engageable with said limit switches to stop traverse oi the trolley in opposite directions; the amount of traverse b'eing varied by the adjusted positions of said members; direction-selecting switches and circuits connecting them with the traverse motor circuit; said direction-selecting switches being actuated by the aforesaid switch-actuating means; the circuits connecting the directionselecting switches and the limit switches with the motor circuits being so connected and interlocked that the setting of the aforesaid adjustable members to effect traverse of the trolley in either direction from a fixed point to a predetermined point on the track also adjusts the setting, for the direction-selecting switches so trolley drum for driving the trolley line; a reversible motor driving the trolley drum; primary and control circuits for the two motors;

direction-selecting switches and circuits connecting them with the traverse motor circuit; a pair of adjustable time relays connected to the primary circuit of the trolley motor and arranged so that the trolley motor cannot start rotation in either direction until one or the other of said time'relays has closed, thus effecting a delay for a predetermined and adjustable time interval bei'ore traversing in either direction begins after each hoisting operation; and an interlocking circuit preventing return movement of the trolley after stopping and after the proper directionselecting switch has been closed, until lowering and hoisting of the material'carrier have taken place.

31. A traversing hoist installation comprising, in combination, a reversible trolley motor; a reversible hoist motor; a trolley drum driven by the trolley motor; a trolley rope movable in opposits directions by said drum; a hoist drum driven by the hoist motor; a hoist rope wound inand paid out by said hoist drum; a trolley moved in opposite directions by said trolley rope; a bucket. suspended from the trolley by the hoist rope; said bucket being open at the top for gravity loading and being discharged by gravity; pri mary motor circuits; control circuits for governing the primary circuits; interlocking circuits to prevent traversing while hoisting or lowering while traversing; and a series 01' manually controlled switches connected in the control circuits for initiating the various steps of the bucket cycle, there being one switch for traverse in each direction, one switch for hoisting and one for lowering; switches in the hoist motor circuit and in the traverse motor circuit to stop hoist and traverse: said manual control switches and the circuits controlled thereby being so connected and arranged that once any portion of the cycle is initiated, movement oi the bucket will continue until the end of that portion or the cycle, unless the bucket is stopped by said stop switches.

32. A conveyor system comprising a carriage, material-supporting structure adapted to be transported by said carriage, a loading station, track. structure for said carriage extending in several directions from said loading station, means for hoisting said material-supportingstructure from said loading station toward said carriage, reversible driving means for said carriage, and means responsive to predetermined position *of the ascending material-supporting means to efiect in proper sequence disabling of said hoisting means therefor and actuation of said carriage-driving means in the proper sense to transport the material-supporting structure in any desired direction from said loading station along the proper track structure.

33. A conveyor system comprising a carriage, material-supporting structure adapted to be transported by said carriage, a loading station, means for hoisting said material-supporting structure from said loading station toward said carriage, reversible driving means for said carriage, track. structure for said carriage extending in several directions from, said loading sta-.

tion, means responsive to predetermined position oi the ascending material-supporting means to elect in proper sequence disabling said hoisting means therefor and actuation of said carriage-driving means to transport the material-supporting structure in a selected direction from said loading station along the a proper track structure, and means responsive to predetermined position of the traveling carriage structure for disabling said driving means therefor. a

34. A conveyor system comprising loading and unloading stations, a control station, a carriage. an electric motor at said control station for moving said carriage between loading and unloading stations a material-supporting structure adapted to be transported by said carriage, a

second electric motor at said control station !or hoisting and lowering said structure toward and away from said carriage, relays located at said control station ior controlling the energisation and direction of rotation of said motors, and switch structure driven by said motors for controlling relays automatically to efiect lowering and hoisting or said structure at said stations and travel of said carriage between said stations,

38. A conveyor system comprising at least one loading station and at least one unloading station, a carriage, an electric motor for moving said carriage between loading and unloading stations, material-supporting structure, a second 1 matic operation at motor for hoisting and lowering said structure toward and, away from 'said carriage, limit switches responsive to positions or said carriage and structure and'relays controlledthereby automaticaily to efi'ect control or said motors in proper sequence to move said carriage between stations and hoisting and lowering 01' said structure at said stations, and manually controlled switching mechanism for interrupting automanual control of the carriage and structure tor continued movement in the same direction or reverse direction.

38. A conveyor system'comprlsing atleast one loading station and at least one unloading station, a carriage, an electric motor for movin said carriage between loading and unloading stations, material-supporting structure, a second electric motor for hoisting and lowering said structure toward and away from said carriage, limit switches for stopping said first motor upon arrival 01 said carriage at said stations and etfecting operation of said second motor for lowering said structure, a retarded-action relay for aflording a predetermined time interval beiore.

lowering at at least one oi said stations, a limit switch for stopping said second motor at desired lower position at one of saidstations. and a second retarded-action relay adjustable independently of said first retarded-action relay eifecting energization of said-second motor to-hoist said-structure after a predetermined interval at ihe other at said stations.

3'1. A conveyor system comprising at least-one loading station and at least oneunloading staiion, a carriage, an electric motor tor eflecting so,sso

said second motor for lowering said structure,

I stantially simultaneous deenergization of said mainder oi the operations. 39. An automatic conveyor system comprising any stage and establishing and away tromsaid carriage, means operated charged at the unloading point to permit dismovement 0! said carriage between said stations, material-supporting structure, a second eleciric motor for hoisting .and lowering said structure toward and away from said carriage, limit switches for stopping said first motor upon arrival of carriage at. said stations and energizing a retarded-action relay for afford ng a predetermined time interval beiore lowering, and means for disabling said retarded, relay to permit upon subsequent hoisting of said structure subsecond motor and energization of said first motor.

38. A conveyor. system comprising at least one loading station and at least one unloading'station, a carriage, an. electric motor for moving said carriage between loading and unloading stations, material-supporting structure, a second' electric motor for hoisting and lowering said structure toward and away from said carriage, limit switches for stopping said carriage at said stations by de-energization oi the first motor and for ei!ecting lowering of said structure at lower and upper limits of its travel by control of said second motor, and re-energization of said first motor for movement oi. said carriage to the other of said stations, and retarded-action relays aiiording predetermined time intervals before lowering of said structure at said stations, i

and between lowering and hoisting at the loading station, and means for excluding said retarded-action relays from circuit for the rea loading station and at least one unloadin station, a carriage, an electric motor therefor, material-supporting structure, a second motor for moving said structure toward or away-from said carriage, a control system including limit switches and relays ior eflecting operation of said -motors in proper sequence and direction" of rotation to transport material from said loading station, manually operable switching means to permit control oi ,said carriage motor. and means including a limit switch rendering said manually operable means inoperative during energization of said second motor.

40. A iuli automatic conveyor system comprising a carriage, driving means for moving said carriage between loading and unloading staiions, a bucket adapted to be transported by said carriage and having doors, motive means mr hoisting and lowering said bucket toward by the bucket in loading podtion to permit fiow of material to the interior thereof, means for efi'ecting ascent oi the bucket byits said mo tive means after the bucket has been loaded, latch mechanism for said bucket doors tripped upon engagement with material previously discharge oi' the bucket contents, means responsive to position of the carriage at said stations for disablingits said driving means and for efi'ecting lowering 01 said bucket-by its said motive means, means responsive to predetermined position 0! the ascending bucket at each of said stations for disabling its said motive means andefiecting movement of said carriage structure by its said driving. means to the other of said stations,and means operated by said engagement of said bucket while descending at an un1oad-.

ing station for effecting ascent of the bucket by its said motive means, the system when set into

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