US2108457A - Apparatus for automatically feeding metal pigs - Google Patents

Description

Fe. 15, 193. v, TQBIA 2,398,457

APPARATUS FOR AUTOMATICALLY FEEDING METAL PIGS Filed Dec. 4, 1935 8 Sheets- Sheet 1 v. TOBIA 108,457

APPARATUS FOR AUTOMATICALLY FEEDING METAL 'PEEGS Filed Dec. 4, 1935 8 Sheets-Sheet 2 60 J5. J9 2a:

Ffib f l 3o V TOBlA 2,108,457

I APPARATUS FOR AUTOMATICALLY FEEDING METAL PIGS Filed Dec. 4, 1935 8 Sheets-Sheet 3 M Q IHIIIIII W MDQQWWL mm APPARATUS FOR AUTOMATICALLY FEEDING METAL PIGS Filed Dec. 4, 1935 8 Sheets-Sheet 4 Feb. 15, W38. v. TOBIA APPARATUS FOR AUTOMATICALLY FEEDING METAL FIGS 8 Sheets-Sheet Filed Dec. 4, 1955 Fe. 1, 393. v. TOBIA I APPARATUS FOR AUTOMATICALLY FEEDING METAL PIGS Fiied Dec. 4, 1955 a Sheets-Sheet e W 7 I w 2, WAS? i 6 xwmgmz w 59,13

Feb. 1, 193.

v. TOBHA 52,10,457

APPARATUS FOR AUTOMATICALLY FEEDING METAL PIGS Filed Dec. 4, 1955 8 Sheets-Sheet 7 igyzz a I N VE N TOR Vmcem 760/61 II T TORNE Y5 Feb. 15, was, v, T IA 2,308,457

APPARATUS FOR AUTOMATICALLY FEEDING METAL PIGS Filed Dec. 4, 1935 8 Sheets-Sheet 8 Patented Feb. 15, 1938 UNITED STATES PATENT OFFICE APPARATUS FOR AUTOMATICALLY FEED- ING METAL PIGS Application December 4, 1935, Serial No. 52,795 In Great Britain December 8, 1934 16 Claims.

of twenty-five, comprising five layers of live pigs each. It is, however, desirable to feed the pigs into the melting pot one at a time at regular intervals, the chief advantages accruing being that the variation in temperature of the molten metal in the pot due to the introduction of the solid pigs is minimized, and this is also the case in respect of the level of the molten metal, with the result that the sides of the melting pot are not subjected to the action of the dross, which forms on the surface of the molten metal and which becomes attached to the walls of the pot at, that surface, to the same degree as is the case if there be considerable variation in level. A

further advantage lies in the fact that, when using alloys, the maintenance of the correct proportion of the constituents inthe melting pot is facilitated if the pigs are fed in at a uniform rate with the resultant minimization of temperature variation. The present invention has for its main object to facilitate the handling of the pigs in groups as above described and theirfeeding into the melting pot one by one at regular intervals. 4

The invention consists in apparatus comprising a travelling belt or like conveyor on which the groups of pigs may be placed and a co-operating elevator having one or more cradles adapted to lift the pigs one layer at a time and to deliver them on to a delivery device, such as a chute or.

roller platform, provided with means for ,detaining the pigs constituting the layer and releasing them one by one at regular intervals into the melting pot. For the purpose of supporting the groups of pigs, the travelling belt, arranged so that its upper operative length is substantially horizontal, is fitted with a series of revoluble tables, each of a size and shape suitable to receive one group of pigs. The elevator with which the travelling belt co-operates may be constituted by twochains passed over upper and lower pairs of sprocket wheels, the rising and falling portions of the chains being substantially vertical 55, and the wheels ineach pair being connected so as to rotate together. In this casethere is provided a number of cradles each serving to lift a layer of pigs and constituted by two members, one on each of the chains, and pivoted thereto so as tobe capable of swinging toward or away from each other for the purpose of engaging or releasing a layer of pigs. In an alternative construction, there is a single cradle only arranged to travel upwardly with a single layer of pigs, to deposit them on to the delivery device and then to return by the same path fora second layer.

In either of the above constructions, since, as above mentioned, the pigs in each layer extend in a direction at right angles to those in the layers above and below, it is necessary that, after each layer has been lifted by the elevator, the group of pigs shall be rotated through a right angle about the vertical axis in order that, when the time comes for lifting the next layer, the pigs therein shall extend in the correct direction for engagement by the cradle. Accordingly, mechanism, automatically operated in sequence with the conveyor and elevator, is provided for periodically rotating the table which, for the time being, is in position for co-operation with the elevator.

In, order that the invention may be clearly' understood and readily carried into effect, it will now be described more fully with reference to theaccompanying drawings which illustrate two forms of apparatus in accordance therewith and wherein:-

Figure l is a side elevation of one form of apparatus comprising conveyor and elevator units, certain gear-wheels being shown in chain-dotted lines only in order to avoid obscuring parts lying behind them,

Figure 2 is a side view of the elevator unit to an enlarged scale,

Figure 3 is a section on the line AA of Figure 1 to the scale employed in Figure 2,

.Figure 4. is a partial section on the line A-A ofFigure 1 to a still further enlarged scale,

.Figure 5 is a plan View of a detail on the line B'-B of Figure 4,

Figure 6 is a side elevation of a modified form of apparatus,

Figures '7 and 8 are respectively side view and plan of certain details of the modified apparatus illustrated in Figure 6, but to a larger scale, certain other features being omitted or shown chaindotted'for the sake of clearness,

Figure 9 is an end elevation of a portion of the elevator unit shown in Figure 6 seen from the right-hand, side,

Figure 10 is a similar view as seen from the left-hand side.

Figures 11 and 12, together constituting a single diagram, illustrate the electrical circuits of the apparatus described with reference to Figures 6 to 10.

Referring to Figures 1 to 5, the metal pigs I, normally stacked in groups of five layers, each layer comprising five pigs as shown, are supported on a series of tables 2, each rotatable about an axis at right angles to its surface. In Figure 1 six of such tables are shown, but it is to be understood that any number may be employed and, in fact, in Figure 4 a further table is shown in the inverted position which each table occupies in succession in the manner described below. Each of the rotatable tables 2 is supported by means of a ball race 3 from a non-rotatable frame 4, connected by means of lugs 5 with two endless conveyor chains 6 passed around pairs of sprocket wheels I and 8 located respectively at opposite ends of the apparatus, 50 that the portions of the conveyor chain 6 lying between them extend in substantially horizontal directions. The weight of the tables 2 and their supporting frame 4 as Well as of the groups of pigs I which may be placed on the tables is taken by channel guides 9 and I extending respectively over the length of the conveyor unit, and with which rollers II, carried by the frames 4 and extending laterally therefrom, are adapted to cooperate. The groups of metal pigs I are loaded on to their respective tables 2 when each of the latter is near the right-hand end of the conveyor unit, as seen in Figure 1: the tables are then caused to travel to the left toward the elevator unit under which each group of pigs remains stationary for a sufiicient period to allow the pigs to be dealt with by the elevator unit in the manner described below.

In order to secure the necessary periodic motion of the conveyor unit, the sprocket wheels 8 are driven from a continuously running shaft I2 which, as described below, also serves to drive the elevator; on the shaft I2 there is a pinion l3 meshing with a gear wheel I4 mounted on a spindle I5. Fast on the spindle I5 there is also a toothed segment I6 which gears with a toothed wheel IT on the spindle I8 of the sprocket wheels 8. Thus, although the spindle I2 revolves continuously, the sprocket wheels 8 are rotated intermittently, and the above-described gearing is so designed that the period during which the conveyor chain 6 is stationary occurs while one of the groups of metal pigs I is in its operative position relatively to the elevator and is by this means caused to remain there for a sufiiciently long period to allow of all the pigs being dealt with by the elevator. The sprocket wheels 8 are then rotated by the above-described gearing to a sufiicient degree to bring the group of pigs next in succession into the operative position relatively to the elevator where it remains for a like period and the sequence of operations is repeated.

The elevator unit comprises a pair of endless chains I9 each encircling upper and lower sprocket wheels 20, 2|. The lower sprocket wheels 2| are mounted on the driving shaft I2 so that the sprocket wheels and elevator chains are continually in motion in such a direction that the righthand portions of the chains, as seen in Figures 1 and 2, move in the upward direction. Attached to the elevator chains I9 is a series of five cradles, each comprising two swinging members 22 respectively pivoted at 23 to the chains I9, the

pivots being, as clearly seen in Figure 3, so located as to enable the members 22 to swing toward or away from each other. The members 22 are provided with inwardly directed extensions 24 adapted to engage underneath lugs 25 formed at opposite ends of each of the metal pigs I, whereby, as clearly appears from Figure 3, each cradle on its upward travel is adapted to lift a layer of metal pigs. By mechanism described below each pair of swinging members 22 is caused to lift the layer of pigs I which, for the time being, is uppermost in its group, to carry it over the highest position to which the chain I8 travels around the sprocket wheel 20 and then to begin lowering the layer of metal pigs until the latter come into contact with a delivery device consisting of an inclined platform comprising a series of rollers 26 on which the pigs are deposited. In order that, when the chains I9 pass over the upper portion of the sprocket 29 the cradles shall remain in their depending position, each of the pivots 23 is itself pivoted at 2 I in such a direction as to permit the corresponding member 22 to swing in a plane parallel to that of either chain I9. Thus the extensions 24 engaging the lugs 25 remain substantially horizontal and serve to support the metal pigs I until the latter make contact with and are borne by the rollers 26. After thus discharging the metal pigs, the cradles continue their downward motion until, having passed around the lower sprocket wheel 2!, each is again brought to the position in which it serves to lift the layer of pigs which, for the time being, is uppermost in the group which meanwhile has been brought by the conveyor to the operative position.

In order to effect this selection of the uppermost layer of pigs, each swinging member 22 is fitted with an upwardly directed arm 28 having a transverse bar 29 adapted, as the elevator chains travel upwards, to engage at its opposite ends one pair of a series of cam plates 30. As seen in Figure 3, in proximity to its lower extremity, each of these cam plates is so shaped that, as the transverse bar 29 comes into contact with the pair with which it co-operates, it is urged inwardly so as to cause the corresponding member 22 to rock in such a manner as to bring its inwardly directed extension 24 clear of the metal pigs. As, however, the cradle continues to ascend, the bars 29 clear the upper edges of the corresponding cam plates 30 so that the members 22 swing inwardly and this action is arranged to occur at such a moment that the extensions 24 are caused to engage beneath the lugs 25 of the layer of pigs which, for the time being, is uppermost: obviously, this must take place at progressively lower positions as occupied by the successive cradles in the series. Thus, in the apparatus illustrated, there are five cradles corresponding to the number of layers of pigs I in each group, and the cradle which, as shown in Figure 2, is approximately at the middle of its ascent, has functioned to lift the topmost layer in the group. For this purpose, the members 22 must be separated for a suiiicient length of their travel to clear the metal pigs in the four lower layers and the co-operating cam plates 38 are, accordingly, of suificient length to prevent the release of these members until the extensions 24 are opposite the topmost layer of pigs. The action of the succeeding cradle, however, must be such as to clear only the three lower layers of pigs and engage the fourth which is now the uppermost layer. Accordingly, the cam plates 38 adapted to co-operate with the bars 29 of this cradle must be correspondingly shorter: similarly, those which cooperate with succeeding cradles must be made correspondingly shorter still. This construction is clearly illustrated in Figure 2, from which it will also be seen that the bars 29 vary correspondingly in length, the barson the members 22 constituting the first cradle being made sufficiently long to co-operate with the longest pairs of c'am plates which are located respectively at the outside of each series. The next'shorter pairs of cam plates 3|] are located immediately within the longest pairs and correspondingly the bars 29 son the members 22 of the next succeeding cradle are shortened so as to engage with these pairs ofcam plates 30. Similarly the cam plates 30 constituting the succeeding pairs progressively decrease in length and in distance apart and the bars 29 adapted respectively to co-operate with them are correspondingly of progressively decreased length as shown in Figure 2.

For the purpose of rotating the group of pigs in operative position under the elevator, through a right angle'after each layer of pigs has been lifted, there is provided a turntable occupying such a position that it is immediately underneath the rotatable table 2 bearing the group of pigs being operated on by the elevator. This turntable and each of the tables 2 are provided with mutually acting engagement mechanism: the turntable comprises a disc 3|, Figures 4 and 5, on which there are two dogs 32 separated by a parallel-sided space 33. As the tables 2 are drawn forward by the conveyor, chains 6, the disc 3| is in the position shown in Figures 4 and 5, that is to say, the parallel-sided space 33 lies in the direction of travel so that a squared projection 34 from the underneath of the rotatable table 2 which is about to be brought beneath the elevator may enter the space 33, and correspondingly the way is clear for the table which has been emptied by the elevator to proceed on its course. As indicated, particularly in Figure 5, each of the squared projections 34 is of such a width as to engage the parallel inner faces of the dogs 32, so that, on the disc 3| being rotated, the table 2 is rotated with it. For the purpose of rotating the disc3| and dogs 32, there is provided a continuously revolving shaft 35 driven in any suitable manner such, for example, as by means of bevel gearing from the shaft l2. On the shaft 35 there is a worm 35 meshing with a worm wheel 31 fitted with an upwardly projecting stud 38 adapted to engage a projection 39 on a band 40 comprising one element of a fricthus the disc 3| is continuously rotated from the shaft 35 through the worm gearing and friction drive, unless it is forcibly prevented from' doing so, in which case the friction drive allows for slipping.

ina stationary guide 46 and jointed'to a lever' 41 pivoted at 48. The opposite end of the lever co-operate with a cam 55 on the shaft l2. The design and timing of the cam 50 are such that immediately a layer of pigs has been lifted from the group under the elevator, the plunger 45 is withdrawn from engagement with one of the projections 44, thus permitting rotation of the disc 3| and with it the table 2 and its layer ofpigs which is in the operative position. Before, however, rotation through a right angle has been completed, the cam has operated to allow restoration, by such means as a spring not shown, of the plunger 45 to or toward its original position so that it'is encounteredtby the next succeeding projection 44, whereupon the rotation of the disc 3| and consequently of the group of pigs in the operative position is arrested, the layer of pigs which is now uppermost being then in correct position for engagement with the cradle operating next in sequence: Figures 1 and 2 are drawn to depict this action as having already taken place. 7

After the lowest layer of pigs in a group has been lifted, obviously time must be allowed for bringing the neXt succeeding group beneath the elevator: for this reason, as seen in Figures 1 and 2, the cradles are not equispaced along the elevator chains, the space between the cradle adapted to lift the lowest layer and that operating on the topmost layer being longer than those between the remaining cradles.

Since-the roller platform 26, on to which the pigs are delivered layer by layer, is inclined, the pigs in each layer roll down it so as to make way for delivery of those constituting the next layer. For reasons above mentioned, however, it is desirable that the pigs should be delivered to the melting pot one at a time, and for this purpose, there is provided a detaining and releasing device, comprising a detent 5| pivoted at 52 and adapted to be rocked by means of a connecting rod 53 from a crank disc 54. This disc is fitted on a spindle 55 driven by chain gearing 56 from the spindle 51 on which the sprocket wheels 20 are mounted. The detent 5| is formed with two arms 58 and 59 and the arrangement is such that, on the detent being rocked, these arms project alternately above the level of the rollers 26. For instance, in Figure 2, it will be seen that the arm 58 is so projecting and is consequently preventing the pigs from sliding oi? the roller platform 23. On further rotation of the crank disc 54, however, the arm 58 will be depressed below the level of this platform, but previously to this action the arm 59 has risen so that the foremost pig only is free to slide off the platform, the remainder being detained by the arm 59. Continued rotation of the crank disc 55 results in depression of the arm 59 and to a second roller platform 60 extending at rightangles to the roller platform 26, whence it is delivered to the melting pot.

The apparatus illustrated in Figures 6 to 10 is of the same general type as that above described, comprising, namely a conveyor unit adapted to co-operate with an elevator unit by which the pigs are deliveredto a delivery device adapted to feed them to the melting pot one at a time. As

in the previous case, the metal pigs l are mounted on a series of tables 2 connected with an endless conveyor chain 6 passing around sprocket wheels I and 8. The elevator, however, although of the type comprising an endless chain passing around upper and lower sprocket wheels 20 and 2|, does not operate continuously in the same direction, nor is it provided with a series of cradles. Instead thereof there is a single cradle unit which is caused to travel upwardly and, having reached its highest point as determined by the upper sprocket wheel 26, to move downwardly so as to deposit its load of pigs on to the roller platform or like delivery device 26 and then to return by the same path for a further layer of pigs. The conveyor and elevator are respectively driven by separate electric motors 6|, 62, each operating through suitable gearing, while a third electric motor 63 serves to actuate the turntable mechanism. Obviously, none of these motors is required to run continuously in the same direction and they are automatically controlled both manually by start and stop press buttons and automatically by the various movements of the apparatus in the manner described below. Indications are given on the drawings of the various switches actuated by the apparatus during the course of its operation, but it is to be understood that, generally speaking, such representations are of a diagrammatic nature and are not intended to afford any indication of the actual construction of switches employed.

In the apparatus now under consideration, six tables are employed, as indicated in Figure 6, the loading position for each of these being, as in the previously described apparatus, toward the right-hand end of the machine as seen in Figure 6. In order to load each table, it is necessary that the conveyor should be stopped with the 40 table in its appropriate position, and for this purpose there is provided a switch A adapted, as the conveyor chain 6 travels in such a direction as to bring the tables toward the elevator, to be actuated by means of one of a series of buttons, rollers or the like 64. These are carried by the chain 6 in such positions relatively to the various tables as to actuate the switch A successively when the various tables arrive at the loading position. Due to such actuation, the circuit of the motor 6|, which has hitherto been running in order to drive the conveyor, is. broken and the conveyor therefore stops. The construction of the switch A is, however, such that after a few seconds it again closes, but during that period the circuit of the motor 6| has been opened by the control apparatus at another point, so that the motor does not restart on the automatic closing of the switch A. When, however, the loading operation on to the particular table in the loading position has been completed, the start press button of the apparatus is operated manually, resulting in the restarting of the motor 6! and the travel forward of the conveyor until the next following table has arrived at the loading position, whereupon the conveyor is again stopped automatically and the sequence of operations repeated.

For the purpose of arresting the tables successively in the position in which the elevator may operate on the groups of pigs thereon, a switch B is provided. This is adapted to be successively actuated by a second series of buttons, rollers or the like 65, suitably located along the chain 6. The switch B also operates to interrupt the circuit of the motor 6| and then automatically to reclose itself, but not until the motor circuit has been interrupted by another switch, the action of which is described below.

As above mentioned, the elevator is provided with a single cradle only. This comprises a pair of swinging members 66, seen most clearly in Figures 9 and 10, having inwardly directed projections 67 adapted to lift the uppermost layer of pigs in a manner similar to that existing in the previously described apparatus. The members 66 are pivoted at 66 to a cross beam 69 adapted to slide in vertical guides 10. In Figure 9 the cradle is depicted in full lines as travelling in the downward direction and in chain-dotted lines as having engaged the uppermost layer of pigs and about to commence its upward travel. Obviously, the lowest point to be reached by the cradle must be determined by the height of the particular layer of pigs which, for the time being, is uppermost; that is to say, if a group of pigs has just been introduced beneath the elevator, the downward travel of the cradle must be a minimum in order that it shall engage and lift only the topmost layer of pigs. On its next journey, however, it must reach a lower point in order to engage the second layer and, on subsequent journeys, it must travel to successively lower positions.

In order to determine the point of reversal, the cross beam 69 is provided with a plunger ll, which, on the downward travel of the cradle, comes into contact with the upper surfaces of the pigs in the uppermost layer for the time being. Motion of this plunger is, therefore, arrested, but, as the cross beam 69 continues to travel downwardly, the plunger slides through it. The plunger is provided with upper and lower collars 12 and 13: these collars co-operate with one arm of a bell-crank lever 14 pivoted at 15 to a bracket carried by the cross beam. 69. The other arm of the bell-crank lever 14 is jointed to a plunger 16 mounted in a guide 11 on the cross beam 69 so as to be capable of motion in the horizontal direction, and it will be seen that, on arrest of the plunger 'H by contact with the uppermost layer of pigs, such horizontal motion of the plunger toward the left, as seen in Figure 9, will occur. When this takes place, the plunger is opposite some portion of a swinging frame 18 which extends vertically over a height approximately equal to that of a complete group of pigs; the frame 18 is supported by pivoted links 19 and is spring biassed in a direction opposite to the above motion of the plunger 16. The frame 18 co-operates with a switch C which, on actuation, is effective to reverse the motor 62 which drives the elevator. This action occurs at the moment when the extensions have engaged the layer of pigs uppermost for the time being and results in the downward motion of the cradle being stopped and its upward motion with the layer of pigs commencmg.

The cradle rises to its highest position as determined by the travel of the elevator chain over the sprocket wheel 20, moves across to the opposite side of the elevator in a manner similar to that followed by the cradles in the previously described apparatus, and then descends so that the pigs are deposited on to the roller platform or like delivering device 26, whence they reach the melting pot one at a time by detaining and releasing mechanism similar to that previously described. The

depositing action is illustrated in Figure 10,-

wherein in full lines the cradle is shown as approaching the roller platform 26 and in dotted lines as having depositedits layer of pigs thereon. The downwardmotion of the cradle is," however, allowed to continue somewhat and the swinging members 66 are thereby thrust apart owing to the 5 fact that diverging plates '80' fitted thereto encounter fixed ramps 8!. In this separating mol5 maintaining the swinging members (it in their extended position. This action is, however,1maintained only' overthe first portion of the upward travel, since above the fla'ps83 there are gaps 85 which, when reached by therollers or studs 82, perfnitthe swinging members 66 to fall inwardly tofitheir," normal position. The object of thus keeping ,.'them separated until, on its return motion,'the cradleisclear of the roller platform 26, is to prevent the possibility of its again lifting the pigs which'have just been deposited and have failed to roll down the platform 26 owing to the presence of. other pigs, lower down the platformor for any other cause. Reversal' of theelevato-r after the cradle has passed the roller platform 30 26 is effected by means of a switch' E, actuated by a'ramp 86 carried by the cross'beam 69. 7

It will be appreciatedthat, as in the previously described apparatus, rotation through a right an-.

gle of the group of pigs in operative relationship 7 35 with theelevator is required after the lifting of that adopted, in the apparatus previously de 45 scribed anda description'thereof, in the present instance, is therefore'unnecessary. The spindle 9| of the. turntable .81 is further provided with a spur wheel 92 meshing with a gear wheel 93 mounted on a spindle 94 which also carries a disc :50 95; having five notches 96 corresponding tothe five'layers of pigs in each group, and spaced as indicatedinFi'gure 8. C'o-operating with these notches is alever 91 pivoted at 9B and having attached at its outerend a cord orchain 9 9 passed 5 over an idler wheel H10 and provided atits lower end with a weight fill. The cordo-r chain 99is adapted to operate a-switch G in the circuit of the motor 63, in such a manner that,'on rotation of the disc 95 in a clockwise direction, whichis 60 that imparted to itby the motor 63, when the end of the lever'il'l drops into one of the notches 96,.

' the motor 63 is stopped. The period of stoppage, of course, corresponds to that during which the cradle of the elevator is travelling downwardly toward the group of pigs and is engaging and lifting the uppermost layer. After this action has occurred, rotation of the group of pigs is necessary and, accordingly} the motor 6 3 must be started] This is effectedby a switch D actuated 70 bya, ramp I02 carried by the cross beam 69. The construction of the mechanism acted upon by the ramp lll2, howe,ve r, is suchthat theswit'ch D is operated only on the upward motion ofthe cradle so that, when the latter returns after depositing '75 its load-of pigs on the platform 2 6,th e switch D maining notches.

, theret o';

is not again operated to restart the motor 63. Obviously, the action of the ramp I02 on the switch D must be maintained for such a time as to allow sufficient'rotation of thedisc 95 to cause the lever 91 to be ejected from the notch in which it has been resting. Rotation of the group of pigs through a right angle corresponds to such a rotation of the disc 95 that the endof the lever Bl drops into the succeeding notch 96 and operates to stop the motor 63.

After the table beneath the elevator has been emptied, it is, of course, necessary to restart the eonveyor, in order that the next table in successionrnaybe brought into co-operative relationship with the elevator. For this purpose a switch H is "provided'actuated by a lever I03 carried by the ldisc 95. [As in'dicated'in Figure 8, between the notch '96 correspondingto the lowest layer of pigs and that corresponding to then-highest layer, the angular distance is double that between the re- Thus, after the lowest layer has been removed, the turntable 181 revolves through 180 in order that the elements of the engagement mechanism respectively on the oncoming table 2 and the turntable ill-maybe in their proper mutual engagement position. This rotation of the turntable having been efiected, the lever Hi3 actuates the switch H, with the result that the motor 6| is restarted and the con-. veyor. travels forward until the button or roller 65 next in succession operates to open the switch B. This, of course, occurs when the next succeeding table 2 has been brought into co-operabut not until the lever I03 has rotated sufliciently to allow the switch Hto reopen.

In order, after the last table has been emptied and has passed from beneath theelevator, to stop the conveyor and theelevator, a'switch F is provided. This affects the circuit ofboth the motors 6 land 62 so that these motors are stopped. The switch F is actuated by a button, roller or the like attached to the last of the series of tables 2 or to a point on the conveyor chain 6 in' proximity Thus, after all the tables have been emptied, the whole apparatusis entirely disconnected from the power circuit.

Figures 11 and 12 taken together constitute a complete electrical diagram of the apparatus illustrated in Figures 6 to 10, certain of the items of that apparatus being shown in Figures 11 and 12 and marked with corresponding references. For

the sake'of' avoiding undue complication of the diagram, however, certain features of ordinary construction which would necessarily be embodied in the apparatus, for example, shunt windings of the motors, automatic starting rheostats, overload relays, are omitted, their methodofconnection in the system being perfectly obvious to those'skilled in the art and constituting no feature' of the pres;

tive relationship with the elevator and the abovedescribed sequence of operations is then repeated. Asabove mentioned-the switch B recloses itself,

tracing connections, 'wheren'ec'es'sary, from Figure 11 to Figure 12, the electrical leads which, owing to the necessity of employing two figures to represent a single diagram, are broken, have been marked correspondingly on these figures with the references a, b, w, at. These markings, however, do not constitute references in the normal sense of the term and will not be mentioned in the following description of the diagram.

The electrical supply to the apparatus is assumed to be direct current through a main double-pole switch I28 which at all times when the apparatus is in operation would be closed, thus making the terminals I29 and I38 respectively permanently positive and negative. Further, owing to certain fixed connections, certain other points in the apparatus will always possess a given polarity during the whole time that the switch I28 is closed. Thus the terminal W of the start push button I3I is permanently positive, being connected to terminal I29 by leads I32, I33. Similarly the lead I34 connected to lead I33 renders the contact I35 of the switch E permanently positive, and, further, the contact I36 of the switch D and the contacts I31 and I38 of the switch B are rendered positive from lead I34 via leads I39, I48, I4I, I42. Similarly, from the negative terminal I38 via lead I43, the terminals LC and LT are permanently negative, and this remark also applies to terminal I I I and point I44 connected with terminal LT via leads I45, I46. In the ensuing description, therefore, certain circuits will be traced between these points as being 2 positive and negative respectively.

As above described, the first action required is the loading of the tables 2 with the groups of pigs and for this purpose they must be successively brought to and retained in position X immediately above the switch A, this switch being thereby opened so that the conveyor motor 6| is stopped. Normally, however, the switch is closed and on pressing the start push button I3I, circuit is established from positive at the terminal W of the push button, through the push button, leads I41, I48, relay coil I49, to negative at I44. This results in closing relay switch I58 and circuit is then made from positive at contact I31 of switch B, through the switch, lead I5I, terminal II2, lead I52, switch I58, coil I53 of conveyor motor contactor, lead I54, terminal II3, lead I55, switch A, lead I56, to negative at terminal III. This closes the holding-on switch I51 and the main conveyor motor switch I58. Circuit to the conveyor motor is then established from positive at terminal I29, via lead I59, switch I58, lead I68, terminal AC, lead I6I, conveyor motor 6|, lead I62 to negative at terminal LC. The conveyor then operates to bring the first table 2 to position X at which it opens the switch A, thus stopping the conveyor. As explained above, however, this switch is of such a construction that, after a certain period, it automatically recloses itself; hence, when the table 2, which is in the loading position, has been loaded, on again depressing the start push button, the conveyor motor 6| is started and the conveyor travels until the suc ceeding table 2 breaks circuit at the switch A, this cycle of events being repeated for the loading operation of each table.

On arrival of the table 2 in position Y in which it is in co-operative relationship with the elevator, the switch B breaks circuit between its contacts H2 and I31 and makes circuit between contacts I38 and I63. This breaks the circuit of the conveyor motor so that the table is stopped in positidn Y, and makes circuit from positive at contact I38, switch B, lead I64, switch F, lead I65, terminal I I4, lead I66, relay coil I61 to negative at I44; switches I68, I69 and I18 are thus closed. This completes circuit from positive at contact I38, switch B, leads I64, I1I, terminal II5, lead I12, switch I69, lead I13, arm of interlock switch I14, contact I15, leads I16, I11, terminal I23, lead I18, switch C, lead I19, terminal I22, lead I88, elevator motor down contactor coil I8I, leads I82, I83, I84, to negative at I44; switches I85, I86, I81, I88 are thereby closed. The circuit of the elevator motor is thus completed from positive at terminal I29, leads I59, I89, I98, switch I86, leads I9I, I92, terminal Y, lead I93. field-winding I94 of motor 62, lead I95, terminal Z, lead I96, switch I81, lead I91, terminal LE, lead I98, armature of motor 62, lead I99, terminal AE, lead 288, switch I88, leads 28I and 282, to negative at terminal LT. The elevator is thus started so that the cradle 66 travels in the downward direction in order to pick up the layer of pigs which, for the time being, is uppermost. As

this occurs, the switch C is actuated by means of the plunger H as described with reference to Figure 9. Accordingly, circuit is broken between the contacts I22 and I23 of the switch C and made at contacts I28 and I2I. This operates to de-energize the elevator contactor coil I8 I, whereby the switches I85, I86, I81 and I88 are opened and the motor 62 stopped.

Circuit whereby this motor is restarted in the opposite direction is, however, completed by the contacts I28 and I2I of switch C. This circuit is from positive at terminal W, leads 283, 284, switch I68, leads 285, 286, terminal I2I, lead 281, switch C (lower contacts) lead 288, terminal I 28, leads 289, 2I8, terminal II9, lead 2II, switch E, lead 2I2, terminal II8, lead 2I3, elevator motor up" contactor coil 2I4, leads 2I5,'I83, I84, to negative at I44. This closes switches 2I6, 2I1, 2I8, 2I9, 228 and starts the elevator motor in the reverse direction so that the cradle 66 is raised. For this purpose circuit is completed from positive at terminal I29 leads I59, I89, switch 2I8, lead I92, terminal Y, lead I93, field-winding I94 of elevator motor 62, lead I95, terminal Z, lead I96, switch 2I9, lead 288, terminal AE, lead I99, armature of elevator motor 62, lead I98, terminal LE, leads I91, 22I, switch 228, lead 282, to negative at LT. As the cradle 66 begins to ascend switch C breaks circuit at contacts I28, I2I and remakes it at contacts I22, I23. The contactor coil 2I4 is not,hoW ever, thereby, de-energized, its circuit being maintained throughthe holding-on switch 2I1, As above described, the cradle 66 on passing the switch D actuates it to start the turntable motor 63. The electrical circuits operative to this end will be described below. As the elevator motor continues to operate, the cradle actuates the switch E to break circuit at contacts I I8, I I 9 and to make it at I I1 and I35; thereby the circuit of the contactor coil 2I4 is broken and the switches which it controls opened, stopping the elevator motor.

Completion of circuit at contacts H1 and I35 of switch E results in restarting the elevator motor in the opposite direction, the circuit being from positive at contact I35, through switch E, lead 222, terminal II1, lead 223, reversing relay coil 224, lead I84, to negative at I44. This closes switches 225 and 226, establishing circuit from positive at terminal W via lead 283, switch I18, lead 221, switch 225, leads 228, I16, I11, terminal 123, lead I18,switch 0, lead I19,-ternii'nal J22, lead 180, contactor coil'I8I-, leads'l82, I83,JI84, to negative 'at I46. :This closes the-mainswitches I86, I81 and I88 of the circuit'which, as above explained, causes theelevator motor to'be started in such a direction that the cradle 66 travels downwards and the sequence of operations is'then repeated. As soon as the cradle 66 leaves the switch E circuit is opened at Contacts I I1 and l and reclosed at H6, H9, The circuit of coil IBI, however, remains closed through I holding-on switch I85. v 1 a *It will be noticed that; once theelevator has been started by one-of the tables 2 arriving at position Y, it will continue by'virtueof its-cooperation withswitches C and E'to be repeatedly reversed so thatthecradle 66 travels alternately in the upward and downward direction as requireduntil the tablehasbeen emptied; In performing these repeated reversals, howeverfcircuit is established independently of the [interlock switch, this switch-being providedfor the'purpose of ensuring thatwhen theelevator isstarted bythe arrival of atable 231', position-Y it shall travel in the appropriate direction. 3 Thus, in the above description, it is assumedthatinitial travel in the downward direction in order to take up a layer of pigs was'required, and, accordinglyg'pra viousdownward travel of thecradle wouldhave served to lock the interlock switch so thatits arm I'M bore on contact I'l5. Had, however, the travel of the cradle, before the elevator motor 62 waspreviously stopped, been in the upward direction, the arm226 of the interlock switch would have been bearing on the contact 236, contact be tween the arm l M and contact I15 being broken.

The action'of the mechanism to effect this result is well known and need not be further: alluded to. Contact being made; between-the arm 229 and contact .230, circuit would be established from positive "at'contact 5 3,8 through switch 3 leads I64, VIM-terminal H5, leadI'IZ, switch l69,, lead I13, arm 229, contact 236; leads 23I,2I0, terminal H9, lead 2! I, switch E; lead 2I2, terminal IIB', lead 2I3, contactor coil 2M, leads2l5, 183; I84, to

negative at I66. This serves toclose switches 2 I8;

2 I 9 and 22.0, whereby the ,elevatormotor is started in such a direction as to cause the cradle to travel upwardly as previously described, v f v The action of the switch D in controlling the turntable motor- 63 wi1l now be described. As the cradle 66 passes the'fswitch D,circuit is broken at contacts I 24 and I36and made at contacts I25 and 232. This establishes circuit from positive at contact 232 through switchD, lead 233; terminal I25, lead 236, switch 2I'6, lead 235,'turntab le mo tor contactor coil 236, leads .231, I 86, toflneg'ative at Hi l." This operatesto close switches 238 and 239, and establishes circuitfromipositive at iterminal I29, "leads l59; I39, switch 239, lead 24B, terminal AT, le'adf24l, turntable motor 63, lead 262, to negative at terminal LT. Gearedto revolve with the motor 63 isthe star-wheel 95, whereby switch G is' actuated. Qn rotation of the star-wheel the switch G bridges contacts I26, 243; whereby, shortly after the turntable motor 63 hasbeen; started, a holding-on circuit is completed from positive bsenteeism: switch B via lead'ZM, switch G, lead 2'45,jtermi nal 1 I26, lead 2416, switch 238, contactorcoil 2'36, leadsj 2 3 1, E84, tonegative at I44. 'When,how.ever, the turn: table motor 63 hasrevolved sufficiently to turn the. table. 2 for the time being in"positionl"Y through'a right angle, the star-wheel 95 oper cites to open'the switchG whereby theturhtable Patent of the United States is:-

contactor 236 is de energized and its switches opened thereby stopping the motor 63. It is then cycle of operationsrepeated. It will, however, be

observed that the form of the star-wheel 95 is such that, after the last layer of pigs has been lifted, the switch G is maintained closed for a period twice the length of its previous closures in order that, for the reasons above mentioned, the turntable shall be rotated through instead of 90. r

In order to re-start the'conveyor after a table has'been emptied, the switch H comes into operation. This is driven in such a manner as to close contacts at H6 after the last layer of pigs has been lifted, and before the cradle 66 reaches the switch E. When 'actuationof this switch by the cradle occurs, the contacts In and !35 are bridged and the reversing relay coil 22 4 excited as above described. Circuit is then established frompositive at contact I 31 of switch B through lead 246, contacts I I6 of switch H, lead 241, terminal I I6, lead 248,'switch 226, lead 266, conveyor contactor coil I53,=lead'I54, terminal II3,le'ad'I55,

veyor'and control the movements of the elevator and turntable in the manner above described.

After the'last table of the series has been emptied and has left position Y, switch F is 3 opened by the'conveyor as above stated. This operates to break thecircuit of the relay coil I67, allowing switches I68, I69, and I'Hl to open and stop the elevator. Motion of the conveyor, how= V everjcontinues until the switch of the motor 6| is opened by actuation of the switchA when the leading tableof the series arrives at position X.

While two examples of apparatus in accordance with theinvention have been described and illustrated, it is obvious that many other combinations within its scope might be'devised. Furtheir, features above described might be combined in other ways: for instance, in the'apparatus depicted in Figures 1 to 5, in place of driving the conveyor intermittently from a continuously revolving shaft, it might be actuated by a separate electricmotor underautomatic control, as described with reference to Figures 6 to 10.

- WhatIclaim and desire to secure by Letters 1. Apparatus for" the automatic delivery of metal pigs, comprisingin combination a conveyor in co-operative relationship with an elevator, a series of tables on said conveyor for the receptionof groups of pigs, each of said tables being revoluble about an axis at right angles to'its sup porting surface, means for rotating the table in said series for thetime being in operative relationship with the elevator througha right angle after each layer of pigs in a group on said table has been lifted and a delivery device, on which each layer of lifted pigs is deposited.

' '2. Apparatus for the automatic delivery of metalpigs stacked in superposed layers wherein the pigs in each layer lie at right angles to the pigs in the next layer, comprising in combination a conveyor in co-operative relationship withian elevator constituted by upper andlower sprocket wheels and endlesstravelling chain mechanism, a series of 'lifting'cradles on said chainmechanism,

and means operatively associated with thecradles for rotating the stack of pigs relatively to the conveyor to bring the top layer of pigs into position to be lifted, and means for causing the cradles selectively to lift the top layer of pigs.

3. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in cooperative relationship with an elevator, a series of tables on said conveyor for the recep tion of groups of pigs, each of said tables being revoluble about an axis at right angles to its supporting surface, a continuously rotating shaft, a friction slip device comprising driving and driven members in operative. connection with said shaft, mutual engagement mechanism associated with the driven member of said slip device and with each of said tables and means, controlled in synchronism with the movements of said elevator, for intermittently arresting rotation of said driven member.

4. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator, a series of tables on said conveyor for the reception of groups of pigs, each of said tables being revoluble about an axis at right angles to its supporting surface, a continuously rotating shaft, a friction slip device comprising driving and driven members in operative connection with said shaft, mutual engagement mechanism associated with the driven member of said slip device and with each of said tables, a disc in driving relationship with said driven member, projections on said disc, a plunger movable into or out of engagement with any of said projections, and a pivoted lever for actuating said plunger in synchronism with the movements of said elevator.

5. Apparatus for the automatic delivery of metal pigs, comprising in combination a con veyor in co-operative relationship with an elevator constituted by upper and lower sprocket wheels and endless travelling chain mechanism, a series of lifting cradles on said chain mechanism, each of said cradles comprising a pair of pivoted members capable of swinging toward or away from each other, means for rotating said sprocket wheels continuously in the same direction, a projecting element on each of said pivoted members and a plurality of cams each of which is adapted selectively to engage one of the projecting elements thereby holding the pivoted members to which they are engaged out of engagement with selected layers of pigs.

- 6. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator, a cradle on said elevator, mechanism on said cradle for lifting the uppermost layer of metal pigs in a group, a delivery device and means for raising said cradle from the position in which it is effective to lift a layer of pigs from a group in operative relationship with said elevator to that in which it deposits said pigs on said delivery device and for returning said cradle by the same path.

7. Apparatus for the automatic delivery of metal pigs comprising in combination a conveyor in co-operative relationship with an elevator, an electric driving motor for said elevator, a cradle on said elevator, mechanism on said cradle for lifting the uppermost layer of metal pigs in a group, a delivery device, ,reversing switches in the circuit of said motor and actuating means for said switches automatically operative when said cradle respectively is in position to lift a layer of pigs from said conveyor and has deposited said layer on said delivery device.

8. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator, an electric driving motor for said elevator, a lifting cradle on said elevator, a delivery device, reversing switches in the circuit of said motor and actuating means for said switches automatically operative when said cradle respectively is in operative lifting position relatively to the top layer of a group of pigs in operative relationship with said elevator and has deposited said layer on said delivery device.

9. Apparatus as in claim 8, wherein the actuating means effective for reversal when the cradle is in position operative for lifting includes an element so located as, when the cradle travels downwards, to bear on the successive top layer of pigs.

10. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator, a series of tables on said conveyor for the reception of groups of pigs, each of said tables being revoluble about an axis at right angles to its supporting surface, an electric motor for rotating the table in said series for the time being in operative relationship with said elevator through a right angle after each layer of pigs on said table has been lifted, a starting switch in the circuit of said motor and actuating means for said switch operated by said elevator after each of said layers has been lifted.

11. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator, a series of tables on said conveyor for the reception of groups of pigs, each of said tables being revoluble about an axis at right angles to its supporting surface, an electric motor for rotating the table for the time being in operative relationship with said elevator through a right angle after each layer of pigs on said table has been lifted, a switch in the circuit of said motor and means, actuated on rotation of said table,

whereby, on completion of rotation through a right angle, said switch is opened and said motor stopped.

12. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator, an electric driving motor for said conveyor, a switch in the circuit of said motor, mechanism automatically actuated by the motion of said conveyor whereby said switch is opened when said conveyor is in a position such that a group of metal pigs on said conveyor is in operative relationship with said elevator, and mechanism for closing said switch automatically actuated on removal of the lowest layer of pigs in a group in operative relationship with said elevator.

13. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator, an electric driving motor for said conveyor, a switch in the circuit of said motor, mechanism automatically actuated by the motion of said conveyor whereby said switch is opened when said conveyor is in a position such that a group of metal pigs on said conveyor is in operative relationship with said elevator, a further switch in the circuit of said motor, a series of tables on said conveyor for the reception of groups of pigs, each of said tables being revoluble about an axis at right angles to its supporting surface, a motor for periodically rotating the table in said series in operative relationship with said elevator through a right angle and means for closing said switch automatically actuated by said second-mentioned motor.

14. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator, an electric driving motor for said conveyor, a switch in the circuit of said motor, mechanism automatically actuated by the motion of said conveyor whereby said switch is opened when said conveyor is in a position such that a group of metal pigs on said conveyor is in operative relationship with said elevator, an electric driving motor for said elevator, a switch in the circuit of said motors respectively actuating said conveyor and said elevator and means for opening said switch automaticaly actuated on motion of said conveyor after the last group of pigs has been removed from its position of operative relationship with said elevator;

15. Apparatus as in claim 6, including outwardly inclined ramps located in that part of the path of the cradle traversed immediately after said layer of pigs has been deposited on said delivery device and pivoted flaps in proximity to said ramps, whereby the elements of said cradle are separated clear of said layer of pigs and are maintained so separated during the return travel of said cradle past said layer.

16. Apparatus for the automatic delivery of metal pigs, comprising in combination a conveyor in co-operative relationship with an elevator; a

series of tables on said conveyor for the reception of groups of pigs, each of said tables being revoluble about an axis at right angles to its supporting surface, and means in operative association with said elevator for intermittently rotating the table for the time being in operative relationship with said elevator about its axis through a right angle.

VINCENT TOBIA.

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