US3504734A - Electrode knockout mechanism - Google Patents

Description

A ril 7, 1970 N. LESK ELECTRODE KNOCKOUT MECHANISM Filed March 29, 1968 INVENTOR NORMAN LESK %W\ ATTORNEY United States Patent 3,504,734 ELECTRODE KNOCKOUT MECHANISM Norman Lesk, Laurelton, N.Y., assignor to Treadwell Corporation, New York, N.Y., a corporation of New York Filed Mar. 29, 1968, Ser. No. 717,340 Int. Cl. B22d 17/22, 29/00 U.S. Cl. 164-347 2 Claims ABSTRACT OF THE DISCLOSURE Background of the invention It has heretofore been known to associate a vertical pin slidably with the bottom of a mold with lower end of the pin extending downwardly to the level of an inclined surface of an underlying stationary arcuate cam track so that as the casting wheel is turned in its operation, the lower end of the pin carried by it engages and slides upwardly on the cam track, thus raising the pin and lifting one end of a formed anode from the mold.

This accepted arrangement has several disadvantages. For example, the bottom of the lifting pin slides directly upon the inclined cam surface and the resultant friction tends to cant the pin in the opening provided for it in the mold and in any guide means that might be provided for it. This canting tendency induces excessive wear in the bore or guide through which the pin extends thereby impairing its operation and modifying to some extent its coaction with the cam. The frictional engagement also may cause excessive wear at the lower end of this pin. A further and probably greater disadvantage of the generally accepted lifting pin arrangement is the fact and the upper end of the pin may engage the underside of the anode only at one point in order to lift it. If it is desired to employ two or more pins in association with a single anode mold to lift an anode at two or more points some complications are encountered either in providing pins of different lengths to work in unison on a common cam surface or in providing special or separate cams to actuate the several pins in unison. Under either of these alternative arrangements the mentioned excessive wear takes place and as the wear of the several pins would not be uniform, they would not work in unison as described.

A very effective form of mechanism is one in which the casting wheel rotates around its center as described in United States Patent 2,605,522, McNamara, Aug. 5, 1952, which is fully incorporated herein and after the pour the anode has the interval during which the wheel passes in one revolution to cool and the anode is then lifted out of its mold, or partially lifted out of its mold, by having a pin or anode lifter rod under it travel up to a cam thereby to give a positive ejection. If the anode is stuck in the mold it becomes necessary to loosen it manually and to proceed from there to the next in order to keep such casting operations going continuously.

A highly desirable form of mechanism would be one which would allow a longer period of cooling in the interval permitted by something less than the complete revolution of the casting wheel and, further, which allows 3,504,734 Patented Apr. 7, 1970 for the possibility of a repeated positively exerted force for lifting the anode out of its mold.

It is, accordingly, a fundamental object of the invention to provide an anode lifting mechanism in association With a casting wheel, whereby, when the anode has made a substantially complete revolution after pour and has had a significantly longer period of time in which to cool than that allowed by currently used mechanisms, activation of a hydraulic cylinder, or an air cylinder, is effected to apply a sudden lifting force to said anode by a stroke to give as much as 2 feet of movement, or what is needed, to a cam whereby the cam rises to a horizontal position, engages lifting pins and, thereby, disengages the anode from the mold in which it has cooled.

It is another object of the invention to provide a mechanism by which the cooling period of the cast anode is prolonged substantially through the provision, or with the provision, of a positive disengaging mechanism employing a large mechanical advantage and which permits repeated application of a disengaging force to an anode which may be caught in its mold.

Other objects and advantages of the invention will in part be obvious and in part appear hereafter.

Detailed description of the invention The invention accordingly is in an apparatus comprising, in combination, for use with a casting wheel equipped to be mounted in a horizontal position with its axis extending vertically so that it can be rotated, the wheel carrying radially placed molds in sectors thereof in which castings can be made, the wheel being further equipped with lifting pins which engage the anode castings and lift them respectively out of their molds to positions high enough so that the casting thus lifted can be engaged by the carrying means, either mechanical or manual, suitable for picking up the casting and conveying it to a point of use. In a modification of the invention it is possible to have the activating mechanism arranged so that it can engage a plurality of knockout pins by forming it with a yoke which will coact with the knock out pins to operate them in unison. The detailed structure and advantages of the invention embodying this mechanism are better understood by reference to the following drawings in which:

FIGURE 1 is a diagrammatic plan view of a casting wheel indicating diagrammatically the location of anode molds on the wheel;

FIGURE 2 is a fragmentary elevation section taken from FIG. 1 along line 22 showing the wheel in relation to a removal pit which houses the knockout mechanism; and

FIGURE 3 is a section taken along the line 33 of FIG. 2 showing the knockout mechanism and the means by which it is activated to engage the knockout pins for lifting anodes.

For a detailed understanding of the nature of the operation of the structure constituting the invention reference may now be made to FIGURE 1. The figure is a diagrammatic plan view showing the casting wheel 10, which is formed like a cartwheel having a number of spokes 11, 12, 13 etc., mounted in a pit 20 of slightly larger diameter than the wheel. The spokes of the wheel define sectors supporting anode molds. Here the molds, e.g. 21, 22 are carried in pair of sectors formed by spokes 11, 12, 13, and with horizontal support or bracket 19, 19. In actual dimensions the wheel may be about 45 feet in diameter and the pit as close as 45 to 46 feet in diameter. The wheel is mounted in bearings at its axis and provision is made for rotating it about its axis and indexing it to pouring position. For example, the pouring position constitutes a spout of a ladle of copper to be cast in the molds 21, 22. The operators index the wheel to pouring position, and the spout is made to discharge metal into a mold under the spout. Typical casting is of copper anodes for use in electrolytic refining. The shape of the anode is generally a large fiat sheet as at 23, 24, about 5 feet square and inch thick, having notched sides 25, 26 to help form a slightly enlarged head or cars 27, 28. The casting operation, the head or cars serve as supports at which lifters (e.g. lifting hooks of an anode crane) can be placed under this anode head to lift if out of place.

The important problem in the manufacture or casting of the anodes, or electrodes, is to remove them from the mold after they have been cast. The time which the electrode spends in the mold is a time interval which is predetermined to allow adequate solidification of metal and also that in which the wheel is made to turn as it is indexed into position to receive a casting. Hence, at the given position in the wheel before the point of cast it is important that a solid anode be dislodged from the mold, lifted out of place and the mold be clear to receive another casting. Otherwise, the cycle is upset. Conventional equipment for this automatic casting of anodes might be said to be shown in United States Patent 2,605,522, wherein the knockout mechanism consists of a plunger under the wheel, the plunger carrying a wheel which travels on a cam and as the casting itself is indexed into position the cam follower rides up the cam and, in so doing, exerts an upwardly directed force on the electrode thereby to dislodge it. Inasmuch as this is a gradually applied uniform force, it is not alway completely successful in dislodging the anode, the consequence being that an anode can be stuck in the mold and require stopping of the wheel for a dislodgement.

In FIGURE 2 is shown the mechanism by which this situation is avoided in ejecting electrodes from molds carried by the casting wheel. Thus the casting wheel has mounted on the under side thereof a knockout pin actuator comprised of the yoke 30 carrying slide bar 31, and cam traveller 32, which yoke engages lifting pins or knockout pins 33 and 34, in the casting Wheel itself. These pins engage anode 35 in the bottom cavity wall of the mold, which bar is transverse to the anode and serves to engage it, lift it, and hold it up to be carried otf by conveying apparatus. This portion of the structure may "be considered to be substantially the same as that shown in United States Patent 2,605,522.

It is in the accompanying pit structure wherein the improvement of this invention is specifically located and here it may be observed that the pit incorporates the cavity bounded by vertical walls 41 and 42, and bottom 43, on which is mounted a pair of yokes 44-45, and 46-47 at either end of the cavity. In these yoke which are stationary in the cavity are bearings 48 and 49.

Extending from bearing 48 to hearing 49 is the moveable cam bar 50 having the earns 60 and 61 thereon. Mounted within the structure between the two bearings in space 53 and serving as a fixed point 54 for the hydraulic cylinder 55 is pivot point 56. The cylinder carries arm 57 extensible in conventional fashion by air or fluid pressure.

Connection to the hydraulic cylinder is by conventional hose line and the cylinder may be liquid or air operated.

Important to the operation of the device in this form is the fact the hydraulic cylinder is available for instantaneous activation, positively engaging the anode lifters with a suddenly and firmly applied vertical force, suitable for lifting the electrode.

The vertically applied force is developed by cams 60 and 61 carried by cam bar 50. Each cam is characterized by an initial long low slope where it rides on its rollers to develop a high mechanical advantage in the upward direction,

The operation is as follows: When the wheel is indexed to the electrode r movi g p sit on the hydraulic y i d 55 is activated and it pushes the cam bar 50 so that the cams 60 and 61 ride on rollers 48 and 49, presenting a uniformly elevating upper surface to the cam slide bars 31 which force thus directly transmitted to the anode lifts it out of the mold. In view of the fact that the stroke of the hydraulic cylinder i relatively short and need not *be more than about 2 feet, the force applied to the electrode lifter is quick, sharp, and because of the built in mechanical advantage in the gradual slope of the cam, virtually the equivalent of a mallet blow. It is uniformly suitable for dislodging and knocking out the freshly solidified electrode.

It will be apparent from the structure that the time interval for cooling obtainable by the positive knockout mechanism described herein virtually eliminate the possibility of bending an anode during the lifting process. That is, in the conventional form of mechanism employing a long cam track, length of the cam was of the order of a chord extending from one anode position to another and the cooling interval for an anode was substantially less than the time required for the wheel to make a complete revolution. With the mechanism herein the time of cooling allowed for the electrode is the time it takes the casting wheel to turn from pouring position to the point Where an emptied mold is being dressed for indexing to the sector just about to be filled again. Hence, the time for cooling each anode approaches closely the time of one revolution of the wheel; only the time for lifting and for mold dressing is subtracted.

This longer cooling cycle from anode pour to anode take-off allows for an increased wheel output capacity and also eliminates the possibility of bending the electrode during the lifting process.

A further advantage is that if one of the electrodes sticks in its mold, the cylinder can be made to repeat the jolt necessary to loosen it to remove the casting from its mold. Existing apparatus which employs a fixed cam track does not have the capability of repeating the force supplied to the mold and special measures must be taken when a casting sticks.

An additional mechanical advantage arising from this design is that external loads imposed from the wheel supporting structure by the cam track which required the wheel to travel on the curved track are eliminated and the life of the casting wheel is thereby extended.

When automatic take-off devices are used in conjunction with this improved apparatus it is possible to lower the knockout pins immediately after the anode is engaged by the take-off mechanism. The lowering of the knockout pins eliminates the possibility of pin damage which can occur during the actual removal of the anode from the mold.

In developing the quite sharp vertical stroke of the lifting pins by the horizontal movement of cam bar 50, the dimensions of the lift are related to the length of stroke and the length of the arm of the hydraulic cylinder is thus determined. In a typical instance of a 45 foot wheel the cam bar as shown in FIG. 2 would be about 10 feet long and total overall length of a cam might be about 2 feet. Approximately the first half of the cam riding on the bearing as shown in FIG. 2 would give the pins a lift of, a small fraction of an inch, for example, to /2 inch. This is to provide a dislodging force for possible stuck anodes. Having dislodged the anode, the cam then changes slope to give the bar a substantial lift of the order of six inches to a foot to permit the lifter to engage the anodes. The sharp mechanical advantage thus developed is during about the first half of movement of the cam and, since the stroke is hydraulic and powerfully applied the jolt to the anode is equivalent to a substantial mallet blow to lift it.

What I claim is:

1. In a knockout mechanism for a horizontally mov-. able mold including a cam disposed below the line of mo ement of the mold, plur l v rtical knockout pins of similar length, guided for vertical movement within separate, spaced apertures in the bottom cavity-wall of the mold and limited to such vertical movement, relatively to the mold, to lowermost positions in which the lower ends of the pins are at the same level, a bracket fixed to the underside of the mold adjacent to said pins, and a knockout pin actuator vertically slidably guided in said bracket and having a fiat, integral, horizontal top underlying said plural pins and coacting with the latter to push them simultaneously upwardly to cause their upper ends to protrude at a common level into the cavity of the mold; the improvement comprising an actuator consisting of a cam bar mounted between bearings, cams in said bar adapted to coact with said bar to develop vertical movement of said bar during such horizontal movement thereof, and hydraulic means connected to said cam and a fixed point to provide horizontal movement of said cam and bar.

2. In a knockout mechanism for a horizontally-arcuately movable mold, including an arcuate cam disposed below the line of movement of the mold, plural vertical knockout pins of similar length, guided for vertical movement within separate, spaced apertures in the bottom cavity-wall of the mold, which apertures are in a line which is normal to a radius of the arcuate mold movement, and the pins being limited to such vertical movement, relatively to the mold, to lowermost positions in which the lower ends of the pins are at the same level, a bracket fixed to the underside of the mold adjacent to said pins,

a knockout pin actuator vertically slidably guided in said bracket and restrained 'by the latter against rotation relatively to the bracket, the improvement comprising an enlarged fiat-top cam bar associated with said actuator and underlying said plural pins and coacting with the latter to push them simultaneously upwardly to cause their upper ends to protrude at a common level into the cavity of the mold; the lower portion of said cam bar carrying cams spaced from each other, said cams being adapted to coact with said fixed rollers to derive vertical movement of said bar therefrom during horizontal movement of the bar, and a hydraulic cylinder connected to said bar and a fixed point to provide horizontal movement to said cam bar.

References Cited UNITED STATES PATENTS 2,566,787 9/1951 Zevely 25-41 2,605,522 8/ 1952 McNamara 164404 2,757,414 8/1956 Chaloupka 182 X 3,454,991 7/1969 Rees 185 X J. SPENCER OVERHOLSER, Primary Examiner S. J. BROWN, Assistant Examiner US. Cl. X.R. 74-1 10

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