US3225397A

US3225397A - Ladle carriage, particularly for converters in steel mills

Info

Publication number: US3225397A
Application number: US181343A
Authority: US
Inventors: Grunewald Waldemar; Schops Rudolf
Original assignee: Pintsch Bamag AG
Current assignee: Pintsch Bamag AG
Priority date: 1961-04-01
Filing date: 1962-03-21
Publication date: 1965-12-28
Anticipated expiration: 1982-12-28
Also published as: LU40826A1; BE611297A

Description

Dec. 28, 1965 w, GRUNEWALD ET AL 3,225,397

LADLE CARRIAGE, PARTICULARLY FOR CONVERTERS IN STEEL MILLS 2 Sheets-Sheet 1 Filed March 21, 1962 3 7 l T I Iii FIT L I Q a NN MN T A R Jnven fora: bajdem g buutaaald Dec. 28, 1965 w. GRUNEWALD ETAL 3,225,397

LADLE CARRIAGE, PARTICULARLY FOR CONVERTERS IN STEEL MILLS 2 Sheets-Sheet 2 Filed March 21, 1962 /IIIIIIlI/l United States Patent 1 Claim. in. 22-s2) Our invention relates to ladle carriages, particularly for receiving steel from converters in steel mills.

After blowing of a converter, the steel is poured into a ladle which, by means of the ladle carriage, is kept close to the mouth of the tilting converter. The filled ladle is transported on the carriage to the foundry where the ladle is transferred to a crane or directly emptied through a bottom opening into the ingot moulds.

It is an object of our invention to provide a ladle carriage that, aside from being applicable in the same manner as the known ladle carriages, can also be used for other purposes.

Another object of the invention is to devise a ladle carriage that affords more accurately adapting the varying ladle position to the tilting motion of the converter while the steel is being poured into the ladle.

Still another object of our invention is to devise an improved ladle carriage that affords reducing the pouring distance as well as the danger of spilling and splashing to a greater extent than heretofore feasible with known ladle carriages.

A ladle carriage according to the invention is based upon the known design in which the free end of an outrigger boom serves to hold the ladle, and the outrigger can be moved in such a manner that the ladle, during emptying of the converter, follows approximately the path of the converter mouth. According to our invention, however, such an outrigger boom is designed as a double-armed lever and is mounted for motion with two degrees of freedom of which the first one affords a ladle motion in adaptation to the tilting of the converter, while the second degree of freedom permits an essentially vertical displacement of the ladle independent of the tilting of the converter. Among the advantages thus achieved is the fact that the filled ladle, instead of being transported to the foundry on the heavy ladle carriage, can be put upon a simple rail vehicle which then takes care of further transportation. This reduces the necessary number of the heavy and expensive steel-receiving ladle carriages and also reduces the time required for transporting the steel from the converter to the foundry.

In known ladle carriages the movement of the outrigger boom during filling of the ladle is adapted to the tilting motion of the converter only in a coarse way, so that the purpose of such adaptation, namely to keep the pouring distance as short as possible and to minimize splashing or spilling of steel, is met only incompletely. These shortcomings are virtually eliminated by a ladle carriage according to the invention in that the outrigger lever is longitudinally displaceable relative to its fulcrum and has its rear arm guided along a guiding contour during longitudinal displacement.

Since the guiding contour can be given any desired shape, the path of the ladle can be better adapted in this manner to the converter tilting motion so that the purpose of such adaptation is satisfied to an optimal extent.

According to another, preferred feature of our invention, the above-mentioned guiding contour is constituted by the longitudinal side of a guiding slot. This provides a support for the rear end of the outrigger boom and 3,225,397 Patented Dec. 28, 1965 thereby prevents it from tilting upwardly under its own weight when the boom is withdrawn into the carriage after the ladle is put off.

According to another, more specific feature of the invention, the fulcrum of the outrigger lever is preferably made displaceable in the vertical plane for producing the outrigger motion in accordance with the above-mentioned second degree of freedom.

The displaceability of the outrigger boom relative to a support that forms the fulcrum can be used to further advantage by giving the lower edge of the boom a cam curvature that coacts with the above-mentioned contour at the rear end of the outrigger boom in producing the motion according to the first degree of freedom. The advantage of thus distributing the cam action upon two contours is the fact that the curvature of the contour at the rear end can be kept considerably smoother and shallower than if this contour were alone effective, while the curvature of the lower edge of the boom is likewise only slight.

Because of the considerable width of the outrigger boom, the guidance at its rear end is preferably subdivided into two individual guidance portions. Since the same applies to the support of the outrigger at the fulcrum, the design may result in a statically indeterminate four-point support which may become objectionable in view of the heavy loads to be coped with. This, however, can be remedied by interconnecting the two individual supports that jointly define the fulcrum axis so as to form a mechanical or hydraulic balancing system;

The foregoing and more specific features of our invention will be more fully apparent from the following description in conjunction with the embodiments of ladle carriages according to the invention illustrated by way of example on the accompanying drawings in which:

FIG. 1 is a lateral view of the ladle carriage shown during emptying of steel from a converter into a ladle.

FIG. 2 shows in its left portion a section along the line AA and in its right portion a section along the line BB in FIG. 1; and

FIG. 3 illustrates another embodiment of a ladle carriage by a section corresponding to the left portion of FIG. 2.

The illustrated ladle carriage comprises a frame structure 1 with lateral walls 2 and a counterpoise 3 for compensating the load. The frame structure 1 is rotatable about a vertical axis on a truck 4 whose wheels 5 run on rails 6. The required propulsion drive and the drive for rotating the frame structure about the vertical axis are not illustrated because they are not essential to the invention and known as such. An outrigger boom 7 protrudes from the right of the frame structure 1 (FIG. 1). A portion of the boom 7 extends transversely between the two lateral walls 2 (FIG. 2) and is formed by several boxprofile structures partly visible in FIG. 2. The free end 8 of the outrigger 7 is designed as a fork whose legs straddle a casting ladle 9. Two hooks 10 at the ends of the legs engage from below the respective trunnions 11 with which the ladle is conventionally provided.

Journalled on the rear end 12 of the outrigger 7 are two laterally protruding rollers 13 which are located in guide slots 14 of the respective side walls 2. The lower edge 15 of the outrigger 7 rests upon two

roller pairs

16, 17. Each pair of rollers is journalled on a small teeter member 18. The purpose of using roller pairs is to reduce the area pressure. Carriages of lower weight may be equipped with single rollers in which case the teeter members 18 are omitted. In the illustrated embodiment, each teeter 18 is pivoted on a lever 19 rotatable about a pivot 20 on frame structure 1.

The piston 21 of a hydraulic drive has its head 24 articulately joined with the outrigger boom 7. The ap pertaining hydraulic cylinder 22 is located centrally between the lateral walls 2 and is tiltably mounted at 23 on the frame structure 1. The hydraulic drive has a doubleacting design and serves to displace the boom 7 longitudinally on the

roller pairs

16, 17. Two further hydraulic drives serve for rotating the respective levers 19. The appertaining hydraulic cylinders 25 are pivotally attached at 26 to the frame structure 1, and the respective pistons 27 are connected with the levers 19 by respective links 28. The two cylinders 25 are hydraulically connected in parallel. This is indicated in FIG. 2 by a pressure line 29 interconnecting the two cylinders 25.

In operation, the ladle carriage is run to the location of a converter 30 to be emptied, with the outrigger boom 7, carrying an empty ladle 9, withdrawn into the carriage. With the carriage in proper position, the converter 30 is tilted about the axis of its trunnions 31 after the blowing operation is terminated. The pouring of the steel commences when the converter assumes the dot-and-dash position. For this purpose the boom 7 is placed in the position where the ladle edge and ladle trunnion are at the respective locations denoted by I. With increasing tilting angle of the converter, the boom 7 is run out of the carriage a further extent so that the ladle passes successively through the positions II, III, IV and ultimately reaches the end position V. The dot-and-dash curves denoted by x and y indicate the travel path of the edge 32 at the converter mouth 33 and of the ladle edge 34 respectively. It will be recognized from these paths that the ladle accurately follows the tilting motion of the converter mouth.

The path 3 is obtained by giving the upper edge 35 of slot 14- a suitable guiding contour and also applying a corresponding guide curvature to the lower edge on the boom 7. If only one of these two expedients were used, considerably steeper curvatures either at edge 35 or at edge 15 would result and would cause correspondingly unfavorable stresses and strains.

When the ladle 9 is filled and the converter 30 tilted back to its base position, the boom 7 is withdrawn into the carriage and the frame structure 1 is turned 90 about the vertical axis. The carriage can new travel on rails 6 away from the converter, for example to another rail on which a simple platform car is available for further transportation of the ladle. For lowering the ladle onto the vehicle, the boom 7 is run out for moving the ladle to above the car. Then the boom 7 is lowered by rotation of the levers 19 with the aid of the

drives

25, 27, until the ladle is set upon the platform of the car and the hooks 10 have released the ladle trunnions 11. Thereafter the boom 7 can be moved back into the ladle carriage. The guide slots 14 then prevent the boom from turning upwardly under its own weight. While the ladle is being transported away on a separate, simpler vehicle, the ladle carriage is again ready to receive an empty ladle and can travel to another converter to be discharged.

The hydraulic parallel connection of the two cylinders has the action of a balancing system which causes the two rails 36, by means of which the boom 7 rests upon the respective two pairs of

rollers

16 and 17, to always impose equal forces upon these rollers. The outrigger boom 7 is thus supported in a statically definite manner.

The same effect can be obtained according to FIG. 3 by purely mechanical means with the aid of a balance lever 37 which is pivotally mounted between bearing blocks 38 on a pivot pin 39 in frame structure 1. The levers 19 are connected with the respective ends of the balancing lever 37 by means of cross-type universal joints 40, each permitting a pivoting motion about two axes perpendicular to each other. For simplicity, only one supporting roller 41 is provided on each side. Some difliculty is encountered with respect to design and space requirements of the universal joints 40 which must be given large dimensions because of the very great forces involved. For that reason a hydraulic balancing system as exemplified by FIG. 2 is preferable in most cases.

The purpose of the levers 19 is not limited to affording a filled ladle 9 to be put off the outrigger boom by lowering the latter or conversely to load an empty ladle onto the boom. These levers 19 also permit adjusting and displacing the path y of the ladle edge. This may become necessary or desirable if converters of different dimensions are to be serviced by the same ladle carriage in the same plant, and also if the path x has changed by material burning away from the converter spout.

While we have described the invention with reference to converters in steel mills, ladle carriages according to the invention are also applicable to advantage in other plants requiring molten metal to be poured from a containing vessel structure into a casting ladle by tilting the vessel structure, such as the pouring of aluminum or other light metal from a tilting crucible into a ladle from which the metal is cast into moulds. In such cases, too, the invention affords keeping the pouring distance uniformly short and preventing or greatly minimizing the danger of spilling or splashing, aside from permitting a greater versatility of ladle motion for other purposes.

To those skilled in the art it will be obvious from a study of this disclosure that our invention permits of varying modifications with respect to details and hence can be given embodiments other than particularly illustrated and described herein, without departing from the essential features of our invention, and within the scope of the claim annexed hereto.

We claim:

A ladle carriage for converters in steel plants and similar purposes, comprising a wheeled truck and a frame structure thereon, said frame structure having fixed guide means forming a guide contour extending in a given direction, roller means engaging with said guide means and guidingly displaceable along said contour, a rigid boom forming a double-armed lever extending generally in the given direction of said contour, said lever having an arm fulcrummed on said roller means in guided relation with said contour and being displaceable with said roller means relative to said frame structure in the given direction of said contour, said lever also having a bifurcated frontal arm protruding beyond said frame structure and having two legs for straddling a ladle and adapted at the respective leg ends to hold the ladle, two supporting rollers engaging each of said respective legs from below and being arranged behind each other longitudinally of said lever, a teeter member on which said two rollers are journalled, an arm member pivotally joined with said teeter member and pivotally mounted on said frame structure for raising and lowering said rollers, and balancing means interconnecting the teeter members associated with each leg for conjoint load-sharing operation of said legs.

References Cited by the Examiner UNITED STATES PATENTS 1,629,184 5/1927 Thomas 2282 2,292,599 8/1942 Batie 2282 2,892,225 6/1959 Buhrer et al 22-82 FOREIGN PATENTS 665,205 4/ 1929 France.

743,000 1/1933 France.

614,338 6/1935 Germany.

I. SPENCER OVERHOLSER, Primary Examiner.

MARCUS U. LYONS, MICHAEL V. BRINDISI,

Examiners.