US2533576A

US2533576A - Rotary knockout mechanism for pig-casting machines

Info

Publication number: US2533576A
Application number: US793595A
Authority: US
Inventors: Leo A Gionet
Original assignee: American Steel and Wire Company of New Jersey
Current assignee: American Steel and Wire Company of New Jersey
Priority date: 1947-12-24
Filing date: 1947-12-24
Publication date: 1950-12-12
Anticipated expiration: 1967-12-12

Description

L. A. GlONET Dec. 12, 1950 ROTARY KNOCKOUT MECHANISM FOR PIG-CASTING MACHINES 2 Sheets-Sheet 1 Filed Dec. 24, 1947 1420872507. 150 4. fi/o/vfi L. A. GlON ET Dec. 12, 1950 RGTARY KNOCKOUT MECHANISM FOR PIG-CASTING MACHINES 2 Sheets-Sheet 2 Filed Dec. 24, 1947 stream which supplies'the molds. in. costly delays ".and permits additional 'skulling of'metalin the ladle. The overflow'of molten metal may stall'the chain drive'or cause breakage "of .the chains.

Patented Dec. 12, 1950 UNITED STATES iPATENT OFFICE Leo A. Gi onet,"Duluth, Minm, assignorto The American Steel and Wire *Company of New erseyya corporation of New Jersey -;,A p pi .flation December 24, -1947,- Serial N o 793,595

I 4Claims. -1

"This inventionrelatesto apparatus for insuring'the 'disiodgment. of pigs of metal from the molds of a continuouspig-casting machine.

JMetal' iromsmeltingfurnaces such as theconventional ,ironblast-furnace is commonly .LdlS- posed of by pouring it intothemolds of a .con-

"tinuous pig-casting machine. Such machines are .well-known, usually comprising a plurality of pig molds extending between a pair of parallel chains traveling around spaced sprockets. .A

p ouring.ladle adjacentone end of the machine fills the molds successively. Most of. thepigs" thus castfall .out of the molds; as they travel'around .thesprocket.at'the other end of the machine, "but an occasional 'oig'willxstick in the mold "despite .the precaution usually taken of spraying "the molds witha lime'wash "before each casting, 'Lto prevent sticking. Whena pig fails to fall from the mold at thedelivery end of the machine, it

" may fall at'some point along the lower run'of the chain with .thepossibility of. damage to the machine parts orinjuryto personnel. In such case, thepig must be manually recovered and'returned -'to'the vdeliveryend. If; the pigremains inthe I 'mold until .itiis' carried back toi'the pouring end of the machine it will. cause the molten metal to overfiovrthe moldoccupied'by the sticking pig unless the pouring ladle isoperated to stop the This results Several forms of apparatus have been ,pro-

posed 'forremoving pigs'from the molds of pig- "blows on'the bottoms of the. pi molds as they descend around the sprockets at the discharge end of the casting machine where'all the-pigs should'fall' out unlzss they'adhereahnormaily to the mold. A still further object"is-to-provide meansfor delivering a measured'blow to the molds so asto-test their susceptibility-"to"break- "age'aS'a'resuIt of heat cracks, in addition to' disjlodging pigs therefrom. It is genera 'lyaccepted that amold which'breaks when'cold under-a blow from ;a 12 pound sledge, because of such cracks, has reached the limit-of its useful life. Still another :object is to 'provide pig-dislodging .rnechanism which is entirely enclosed within the sprockets at the discharge .end of the casting machine.

J'In a preferredembodiment or the" invention, I mount a plurality of pivotpins for rotation with .'the sprockets for the mold chains at the discharge end of the "machine.

Conveniently, the gp-insarecarried by one or more spiders mounted .on'theshaft supporting the sprockets and having radially projecting legs. tosaidpins so that, on rotation of the sprockets, ';the'-hammers will besuccessively lifted up and Hammers are pivoted carried over the shaft in back-swinging position. Thenwheirtheir center of gravity movesahead of the pivot pins, the hammers will'fall forward on the descending side of the sprockets and strike the bottoms of the molds successively. The hammers areprefer-ably composed of web plates havingweig-hts attached to their free ends. pair of spiders may be employed and'should have "their legs in staggered relation.

A complete understandingof the invention --m ay-be obtained from the following detailed description which refers to the accompanying drawings illustrating a present preferred em "hodiment. In the drawings:

Figured isa partial horizontal section through the- 'sprocket shaftat the discharge end ofia .pi

casting-machine;

Figure '2'-is a partial-vertical sectiontaken on line li -ll of Figure 1;

"-Fig ure'B is a plan view showing a pair of ham- -mer=supporting spiders, the hammers being 40- omitted for clearness;

FigureA is a side elevation of the spiders showing' the hammers attached to some of the spider legs only;

Figure 5-is 1 an" elevationshowing an assembly of hammers pivoted to each legof' thespiders;

and.

' Figure-6 is anend View cf thehammer assemblyon a leg ofone of the spiders, showing in dotted' lines' there ative location of the" hammer assembly =carrie'd'hy a'legJ-of the other spider. Referring in detail to the drawings,-a plurality O iP molds i0 extend between a pair of' parallel -chainsand are secured "in groups to the links '=H thereof by bolts I2; "Thechains are mainta-ined in proper-"relation to each other by spacer rods I3 secured to the links and having rollers I4 on the outer ends thereof. At the delivery end of the machine, the chains travel around sprockets |5 mounted in spaced relation on a shaft It, usually the head-shaft of the continuous chain conveyor provided by the molds I!) and links H. The sprockets have teeth spaced circumferentially thereof provided with pockets I5 adapted to accommodate the rollers H on the spacer bars |3. The shaft is journalled in suitable bearings, not shown, and is driven by any suitable means, such as an electric motor through appropriate reduction gearing. The elements of the structural framework supporting the upper and lower runs of the chain between the headshaft and tail-shaft have been omitted, as well as the tail-shaft itself and the sprockets thereon since this construction is generally well known and no detailed disclosure thereof is necessary.

It will be understood that the sprockets l5 are driven in the counter-clockwise direction, as viewed in Figure 2, and that the mold-supporting chains travel in the direction indicated by the arrow. The molds are successively filled by. a pouring ladle, in the customary manner at the pouring end of the machine, i. e., the end adjacent the tail-shaft. By the time the molds reach .the vicinity of the sprockets Hi the pigs cast therein have solidified and should fall freely from the molds as the latter are inverted in passing around the sprockets. In order to insure that each mold is freed of its pig, I mount a spider I! on the shaft H5, intermediate the sprockets I5. The spider has a hub I8 and circumferentially spaced arms projecting radially therefrom. Conveniently, a pair of spiders are provided, as clearly shown in the drawings, with their hubs integral and the legs of one staggered between the legs of the other. The dual-spider structure is split transversely through its axis and is clamped to the shaft I6. It is secured thereon by bolts and is keyed thereto so as to rotate with the shaft and sprockets, as shown in Figure 2. One of the legs H) of one spider or the other is in radial'alignment with each of the spacer bars I 3 whose rollers are engaged by the sprocket teeth. The legs IQ of the spiders are slotted at their outer ends and are drilled to accommodate pivot pins 2|. The bottoms of the slots at the ends through the legs as indicated at 22. The legs are also drilled to accommodate fixed bearing pins 23, the purpose of which will appear shortly.

Each leg of the spiders is provided with an assembly of three

hammers

24, and 26, as best shown in Figures 5 and 6. The hammers are pivoted on the pins 2| and hang vertically or remain in the lowest possible position permitted by their engagement with associated parts. Each hammer comprises a web plate 21 drilled and hushed to receive one of the pins 2| and a head portion 28 of increased thickness adapted to deliver an impact blow. The additional weight and thickness of the head portions may conveniently be provided by welding extra thicknesses of plate to the web plates 21. As shown in Figure 6, the

hammers

24 and 25 are disposed on opposite sides of the spider leg l9 while the hammer 25 is fitted into the slot in the end thereof.

The positions successively assumed by the hammers of the several assemblies as the legs on which they are pivoted pass through their various positions are illustrated in Figure 2. It will be apparent from this showing that the hammers hang freely from the spider legs on the ascending iii) side of the sprockets. As the pin on which any given set of hammers are pivoted passes over the top of its circular path, the hammers swing back as far as permitted by the other elements of the structure, 1. e., the web plate of the hammer 25 engages the bottom of the slot in the spider leg and the web plates of the

hammers

24 and 26 engage the projecting ends of the bearing pin 23 in the same spider leg. The hammers thus pass from a vertical position to a backwardly inclined tangential position, through a horizontal position and then reach a position in which they are forwardly inclined with the head portions upraised.

Eventually,'as rotation of the shaft l6 proceeds, the center of gravity of each hammer will pass the dead-center position with respect to the pivot pin 2| after which the hammer will fall freely until it strikes the bottom of one of the pig molds. As indicated by the solid line positions of the hammers shown in Figure 2, one hammer strikes the bottom of each of the three molds secured to each pair of opposite links of the mold-supporting chain. In this way, as each set of three molds moves around the sprockets |5 toward the fully inverted position, the molds are struck individually by the head portions of the freely falling hammers. The resulting impact blows effectively dislodge the pigs from the molds despite any tendency they might have to adhere thereto.

It will be appreciated that the spiders move in unison with the sprockets and chains so that proper cooperation of the hammers with the individual molds is maintained at all times. It will further be apparent that, since the rotary spiders carrying the hammer systems are mounted on the head shaft of the conveyor system, no separate drive or auxiliary power mechanism therefor is required. A further advantage of the invention is that, since the spiders rotate at a predetermined speed and the hammers fall through predetermined arcs before striking the pig molds, they deliver blows of a predetermined force to the latter. The several hammers of each assembly are preferably so proportioned that they deliver substantially equal blows. It will be noted that the hammer 24, which is the shortest of the three, has a heavier head portion than the others of the spider legs are inclined to the radius and that, similarly, the head portion of the intermediate length hammer 25 is heavier than that of the hammer 26 having the greatest length. The hammers are preferably so designed as to deliver a blow which will result in breakage of any mold which is cracked by heat-checking, warpage or the like to an extent such that it should be replaced.

The invention also has the advantages of simplicity, low cost and automatic operation without supervision or maintenance. In addition, the apparatus is enclosed between the sprockets and is thus in an out-of-the-way position requiring no additional floor space. Finally, the hammers deliver sufficient impact to the bottoms of the upturned molds to insure dislodgementof any pig which tends to stickin the mold, thus preventing the undesirable results pointed out above which occur when a pig fails to drop out and is carried back to the pouring end of falls from the mold while the latter is traversing the lower run of the chains.

Although I have illustrated and described but a preferred embodiment of the invention, it will be recognized that changes in the details of the construction disclosed may be made without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. In a pig-casting machine including spaced traveling chains, a shaft having sprockets thereon around which the chains are trained and molds extending between the chains, the combination therewith of pig-dislodging means comprising a spider secured to said shaft between the sprockets having a plurality of radial legs, and a plurality of hammers of different lengths pivoted adjacent the end of each leg whereby, on rotationof the shaft, the hammers fall forward on the descending side of the sprockets and strike the molds successively.

2. The apparatus defined by claim 1, characterized by a pin projecting laterally from each leg of the spider adapted to support the hammers in back-tilted position as the legs pass over the top of their path on rotation of the spider.

3. In a pig-casting machine including spaced traveling chains, a shaft having sprockets thereon around which the chains are trained and molds extending between the chains, the combination therewith of pig-dislodging means comprising a member secured to the shaft between the sprockets, a plurality of pivots spaced circumferentially of said member and a plurality of hammers of different lengths journaled on each pivot whereby, on rotation of the shaft, the hammers fall forward on the descending side of the sprockets and strike the molds successively.

4. The apparatus defined by claim 3 characterized by each of said hammers including a web plate having its thickness increased adjacent the outer end to provide a head portion.

- LEO A. GIONET.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 306,903 Dandurand Oct. 21, 1884 584,691 Laughlin June 15, 1897 589,236 Williams Aug. 31, 1897 691,977 Slick Jan. 28, 1902 845,171 Gardner Feb. 26, 1907 1,230,360 Alinder June 19, 1917 1,898,722 Ford Feb. 21, 1933 FOREIGN PATENTS Number Country Date 531,444 Germany Aug. 10, 1931