US2203831A - Casting wheel control - Google Patents

Description

June 11, 1940. i K, ,1 I .NDNER 2,203,831

CASTING WHEEL CONTROL Fi1ed oci. 8, 1957 2 Sheets-sheet 1 INVENTO June 1l, 1940. K. A. LINDNER CASTING WHEEL CONTROL Filed OCT.. 8, 1937 2 Sheets-Sheet 2 INVENTOR ,/fr/ Zzizdlzei 5 ATTORNEY Patented June 11, 1940 UNITED STATES CASTING WHEEL CONTROL Karl A. Lindner, Baltimore, Md., `assig'nor to American Smeltingand Relining Company, New York, N. Y., a corporation of New Jersey Application October 8,

' 3 claims.

This invention relates to a control for a casting wheel of the type used for intermittently casting metal shapes at a plurality of successive stations. The invention may be applied to any casting wheel of the above type, such as a wheel for casting copper cakes, copper Wire bars, copper or lead anodes or the like.

An object of the invention is to provide an automatic control for an intermittently driven casting wheel of the above type,

Another object is to provide means for automatically stopping the wheel at exact casting positions.

Another object is to provide means for gradually accelerating and decelerating the wheel so as to obtain a smooth and uniform operation with a minimum vibration.

' Another object is to provide for the automatic shifting of the casting Wheel between successive stations in response to the mere pressing of a button or closing of a switch.

Another object is to provide a novel and imv proved mechanism of the type above indicated.

Various other objects and advantages will be apparent as the nature of the invention is more fully disclosed.

Although the novel features which are believed to be characteristic of this .invention are' pointed out more particularly in the claims appended hereto, the invention itself will be better understood by referring to the following description, taken in connection with the accompanying drawings, in which a specific embodiment of the invention has been set forth for purposes of illustration.

In the drawings:

Fig. 1 is a plan view of a typical casting wheel of the type used for casting copper cakes;

Fig. 2 is a diagrammatic chart indicating the different operating positions of the casting wheel; and

Fig. 3 is a schematic diagram showing the electrical control circuit embodying the present invention.

In the following description and in the claims certain specific terms are used for convenience in referring to various details of the invention. These terms, however, are to be given as broad an interpretation as the state ofthe art will permit.

Referring to the drawings more in detail, the invention is shown as applied to a casting wheel of the type used for the vertical casting of copper cakes, although it is to be understood that this particular type of casting wheel is shown only for purposes of illustration and that this inven- 1937, Serial No. 167,927

tion is applicable to various` types of casting wheels which are intermittentlyshifted between a plurality of successive casting stations.

In the embodiment shown in Fig. l the casting wheel comprises a circular frame I0 carrying a plurality of separate molds II which are adapted to be used for casting' a metal shape such as, for example, a copper cake. Each mold il is supported by a bracket I2 which is rotatably mounted by means of trunnions I3 in the frame i0. The frame I0 and the molds above described are carried by a bull ring I4 having internal driving teeth I5. The bull ring I4 is supported by a pair of rollers I6 mounted on suitable brackets I1 carried by a spider I8 and is driven by a pair of spur gears I9 actuated through suitable gear reduction means 20 by driving motors 2| which are likewise mounted on the spider I8.

The molds Il are provided with tilting levers 25 which are adapted to engage stationary dump guides 26 to invert the molds for discharging the cast shapes, and to engage righting guides 21 for reinverting the molds to upright position to receive another casting. The molds are shown as of the water-cooling type, water being supplied through an inlet pipe 30, thence through pipes 3| and manifold pipes 32 to suitable connections (not shown) in the brackets I2. The water supply is controlled by a suitable valve (not shown) which is actuated automatically in accordance with the position of the wheel to supply cooling water during the time that the mold is in upright position and while the metal is being cooled therein, but to shut oi the supply oi' cooling water when the mold is inverted for dumping the casting and while the mold is in the inverted position for cleaning and receiving the mold wash. f".

In the embodiment shown means are provided for pouring two molds at a time. This comprises a pouring spout 35' having apair of discharge nozzles 36 which supply the molten metal to a pouring ladle 31, arranged to direct the metal into the two molds lia in casting position. The pouring spout and ladle may be lled with charcoal or other suitable deoxidizing material to prevent oxidation of the molten metal as is well known in the art. The metal shapes which are discharged from the molds are removed by a conveyor 50 which is driven through suitable gearing 4I by a motor I2,

The operation of this wheel for casting purposes is shown diagrammatically in Fig. 2 in which 'rfi the pouring point is indicated by the line 50.

The cooling zone extends between this line and the line In the positions represented 'by the angle I2 the molds are inverted for dumping purposes. The zone represented by the angle 53 constitutes the cleaning zone in which the molds may be cleaned by scraping or the like. The zone represented by the angle I4 constitutes the washing zone in which a suitable mold wash is applied to the mold cavity prior to casting the cakes therein. In the zone represented by the angle I5 the molds are again returned to upright position for receiving the molten metal. The valve, controlling the cooling water, is open for a period represented by the angle 58 which corresponds in general to the time during which the mold is in upright position. It will be noted that the valve is opened at the time the molds are returned to upright position and is closed just before the molds are inverted tor dumping.

It is to be understood that a conventional type ci casting wheel has been described above for convenience. The wheel may be mounted or driven in other ways and the molds may or may not be water cooled. While the molds have been shown as pivotally mounted to be dumped by inversion, it is to be understood that in certain instances the molds may be dumped by providing the 'mold with a removable bottom which is suitably opened and closed at the proper positions ci' the wheel. Suitable mechanism may also be used for opening and closing the water control valve, auch for example, V as a cam track engaging a control member at suitable positions oi? the wheel. It is further to be understood that any desired number of molds may be arranged to be filled at the same time depending upon the size of the molds and of the wheel and that the invention is not limited to the simultaneous casting or two molds, as shown in the drawings.

The present invention provides means for automatically controlling the driving motors 2| so as to drive the frame I0 and the various molds to bring successive molds into casting position. In the form shown the control is eiected by means of a ag 8|! which is driven by a gear 6| from the bull ring |4 at a gear ratio such that the gear 6l and the flag 30 make a complete revolution while the casting machine is being driven from one casting station to the next. The iiag 3l is adapted to intercept successively the light rays to a pair of photoelectric cells 62 and 33 constituting the deceleration control and stop control respectively.

The control as shown more in detail in Fig. 3, comprises a motor generator set 10 supplying current to drive the motors 2|. The current supplied by the generator is controlled by a starting switch 1|, by the deceleration control photoelectrlc cell 62, and by the stop control photoelectric cell 63.

'Ihe motor generator set 10 comprises a driving motor 12 actuated by any suitable source of current and driving a generator 13 and an exciter 14. The exciter 14 is provided with the usual shunt neld 1l and supplies current to lines w13 and 11. The switch 1| connects relays 1l and 1l across the lines-13 and 11 by means of lleads Il and 3|. The relay 18. when energized, closes a circuit from the line 1i, through lines 18a and 1lb. contactors "l, and line 18e back to the line 11, thereby closing contacts 32 and I3 of the con- -tactor 33. The contact 33 closes a circuit from the generator 13 to the motors 2|. 'Ihe .contact 32 closes a circuit from the lines 18 and 11 to the held winding 84 of the generator 13 through a potentiometer 85. The potentiometer 85 has a contact 33 driven by a motor I1 to variably increase or decrease the excitation applied to the ileld winding 34 and to correspondingly vary the current supplied by the generator 13 to the motors 2|.

'Ihe relay 19 is of the reversing type and is adapted, when closed by the closing of the switch 1|, to connect the motor 31 across the lines 16 and 11 so as to cause the motor to rotate in a direction to cause the contact I6 to progressively decrease the etl'ective resistance of the potentiometer 35, thereby progressively increasing the excitation of the field winding 34 until full voltage is applied thereto. The generator 13 accordingly supplies an increasing current to the motors 2| which causes the motors to smoothly accelerate to a maximum speed. When the contact 86 reaches its end position the motor 81 is automatically stopped by a stop control, not shown, which is actuated by said contact.

With the motors 2| operating at full speed the casting wheel is driven until the flag 60 registers with the light beam applied from a suitable source, not shown, to the photoelectric cell 62. When this occurs the light applied to the photoelectric cell 82 is interrupted and thel photoelectric cell operates through a relay 90 to reverse the relay 19 so as to cause reverse rotation of the motor 81, thereby moving the contact 8S in a direction to gradually decrease the excitation oi the iield winding 34. The motors 2| are thereby gradually decelerated.

The further rotation oi the casting wheel during the deceleration period causes further movement of the iiag i0 until this flag intercepts the light rays applied from a source (not shown) to the photoelectric cell 83. When this occurs the photoelectric cell 83 acts through a relay 9| to open the relay 18, thereby releasing the contactor 331, opening the contacts 32 and 83, breaking the current supply to the motors 2| and instantly stopping the casting wheel. The system is then ready to repeat its cycle of operation when the switch 1| is again closed.

It is to be noted that by this system the motors 2| are gradually accelerated and decelerated.

The casting wheel is accordingly smoothly driven between successive casting stations. Vibration and jerking of the molds in their movement is avoided thus preventing agitation, spilling or other undesirable movement of the cast metal which would result trom sudden starting or stopping of the wheel. Furthermore, the casting wheel ls stopped at the exact casting position by the correct timing of the iiag 30 with respect to theistop control photoelectric cell 03. The deceleration is so controlled that the motors 2| have been brought to a substantial stop by the time the stop control circuit is actuated. It is to be understood that the photoelectric cells 32 and 33 are spaced as required to eect the above operaticn. They have been shown as arranged diametrically opposite for purposes of illustration only.

In this system the motors 2| are caused to automatically carry out the above described cycle of operation. For shifting the casting wheel it ls only necessary to close the switch 1| which may constitute a push button, and thereafter .the casting wheel is automatically driven to the next casting station and is stopped in position to receive the next casting. The casting operai tion is speeded up because it is not necessary for the operator to slow down and stop the casting wheel or to fee for the correct casting poai- 15 tion. The above described system accordingly eliminates all mechanical *manipulations* and results in the continued and uniform operation of the control mechanism for the purpose specified.

It is to be understood that other specic types of control can be substituted for that set forth above. For example, mechanical switches can be used in place of photoelectric cells and stop means may be carried by either the bull ring I4 or the frame I0 or any other suitable part of the apparatus in a position to engage the mechanical switches and actuate the same at the designated deceleration and stop positions. Furthermore, the relay arrangement can be varied to constitute, for example, a standard starting box which may be arranged for reverse actuation for the gradual deceleration and stopping of the motors. In that event, the motors 2l may be supplied directly from a supply main. A motor generator set has been shown and described merely for-convenience. If a standard starting box is employed, the motor 81 and potentiometer 85 may be substituted thereby. It is also to be understood that any suitable type of reversing relay may be used for causing the reversible operation of the' motor 81. Such relays are Well known in the art and consequently the construction thereof has not been set forth herein.

Although a particular embodiment of the invention has been shown for purposes of illustration, it 'is to beunderstood that various changes and modiiications may be made therein by those skilled in the art without departing from the invention as defined in the appended claims.

What is claimed is:

1. Apparatus for casting metal shapes at a plurality of stations comprising the combination with a casting Wheel upon which a plurality of molds are mounted, of driving means for said wheel including a plurality ofelectric motors, said motors being connected in series and providing their own load balance from a common source of power, means to energize and to gradually and evenly accelerate said motors to top speed, and means actuated by said wheel when the latter reaches a predetermined position for gradually and evenly decelerating said motors to lowest speed, and means actuated by said v wheel when said wheel reaches a casting station for decelerating said motor until minimum speed is attained, and means interrupting the circuit between said generator and motor when said wheel reaches a predetermined position.

3. A control for a casting wheel for casting metal shapes comprising a motor driving said casting wheel, a generator supplying power for operating said motor, a variable potentiometer controlling the eld excitation of said generator, means closing the circuit from said generator to said motor for starting the latter, means actuating said potentiometer for gradually increasing the field excitation of said generator so as to gradually accelerate said motor until top speed is reached, means actuated by said wheel reversing said potentiometer for decreasing the eld excitation of said generator and gradually decelerating said motor until lowest speed is reached, and means interrupting the circuit be-V tween said generator and said ping the latter.

KARL A. LINDNER.

motor for stopg

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