US3375945A

US3375945A - Furnace charger crane

Info

Publication number: US3375945A
Application number: US530491A
Authority: US
Inventors: Ross B Mccready; Klaus W Forster
Original assignee: Kerma Corp
Current assignee: Kerma Corp
Priority date: 1966-02-28
Filing date: 1966-02-28
Publication date: 1968-04-02
Anticipated expiration: 1985-04-02

Description

A ril 2, 1968 R. B. MCCREADY ETAL,

FURNACE CHARGER CRANE 5 Sheets-Sheet 1 Filed Feb. 28, 1966 Y SD R R E OET w E VC mm W M S %U A O L RK Y B WWW ATTORNEYS April 2, 1968 R. B. M CREADY ETAL FURNACE CHARGER CRANE 5 Sheets-Sheet i.

Filed Feb. 28, 1966 INVENTORS ROSS B. MC CREADY BY KLAUS W. FORSTEH ATTORNEYS April 1968 R. B. MCCREADY ETAL 3,375,945

FURNACE CHARGER CRANE Filed Feb. 28, 1966 5 Sheets-$heet 3 FIG. 4 INVENTORS ROSS -B. MCCREADY KLAUS W. FORSTER ATTORNEYS United States Patent I 3,375,945 FURNACE CHARGER CRANE Ross B. McCready, Alliance, and Klaus W. Forster, Brecksville, Ohio, assignors to Kenna Corporation, Alliance, Ohio, a corporation of Ohio Filed Feb. 28, 1966, Ser. No. 530,491 13 Claims. (Cl. 214--316) ABSTRACT OF THE DISCLOSURE A crane-type charger for basic oxygen furnaces having cable-type hoist means for connection to a container for material to be charged and in which the container is pivoted about a locus spaced a substantial distance from its supporting connection to the hoist means.

The present invention relates to cranes and more particularly to cranes especially designed for charging materials into vessels, such as a basic oxygen furnace or the like.

In charging basic oxygen furnaces in the manufacture of steel it is the practice to periodically charge the furnace by dumping molten metal and scrap metal into the furnace. Usually, the molten metal is dumped into the furnace by a conventional overhead bridge-type ladle crane which handles the molten metal in ladles suspended from the crane trolley by hoist cables. To a limited extent scrap buckets, or boxes, for containing scrap metal have been transported to and from a furnace and their contents dumped into the furnace by overhead crane equip ment similar to that used for handling ladies of molten metal. Such cranes have been constructed so that a scrap box or bucket is supported from hoists generally connected with the trolley of the crane and movable toward and away from the furnace upon movement of the trolley relative to the bridge of the crane. In installations of the type mentioned, it has been necessary to move the trolley to a position on the bridge where it is located generally vertically above an opening in the furnace before elevating an end of the scrap bucket or box to dump the material contained therein into the furnace. It has sometimes been found inconvenient or impossible to move the trolley into a position vertically above the opening in the furnace prior to dumping the material in the scrap bucket therein.

, A principal object of the present invention is the provision of a new and improved crane structure for supporting and transporting a box or bucket containing scrap material to a vessel, the crane being operable to dump the material transported thereby into the vessel and which is so constructed and arranged that the bucketis pivotally movable about a locus spaced a substantial distance from supporting connections between the bucket and the crane during dumping of the material in the bucket into the vessel.

Another object of the present invention is the provision of a new and improved crane structure operable to support and transport a box, or bucket containing scrap material and dump the material into a vessel of a furnace, or the like and which is so constructed and arranged that the scrap container is supported for movement along a predetermined path toward and away from the furnace and pivoted about an axis or series of axes generally transverse to the path of movement thereof, the axes being spaced from supporting connections between the bucket and the crane, and wherein a pivot axis or axes may pass through the furnace.

Another object of the present invention is the provision of a new and improved crane structure including a scrap box or bucket constructed to contain scrap material and which is operable to dump the scrap material 3,375,945 Patented Apr. 2, 1968 into a vessel of a furnace or the like, the crane being so constructed and arranged that the scrap bucket is translatably movable toward and away from the vessel or furnace by a movable trolley and pivotally movable to dump material into the vessel or furnace, the scrap bucket being translatable upon horizontal movement of the trolley toward and away from the furnace and the pivotal movement of the bucket being accompanied by horizontal movement thereof relative to the trolley.

Other objects and advantages of the invention will become apparent from a consideration of the detailed description of the preferred embodiment thereof in the accompanying specification and from the drawings which form a part of the specification and in which:

FIG. 1 is an elevational view of a crane structure embodying the present invention;

FIG. 2 is an enlarged portion of the crane structure shown in FIG. 1;

FIG. 3 is a sectional view of a crane structure taken approximately at line 33 of FIG. 2;

FIG. 4 is an elevational view taken approximately at line 4-4 of FIG. 2.

Referring to the drawings, the installation illustrated comprises two overhead traveling bridge-type cranes A, B adapted for charging a vessel C, of basic oxygen furnace with molten metal and scrap metal. The furnace and cranes are located in a building, not shown, and bridges D, E of the cranes A, B respectively, are supported on and travel from one location in the building to another along the same runway comprising widely spaced rails, only one of which appears in the drawings. The crane runway rails are supported by suitable elevated structures according to well-known practices. The bridge D of the crane A comprises two beam members'10, 11 connected to end trucks supported by flanged wheels on the rails of the crane runway. The bridge is moved along the crane runway by a driving mechanism of conventional construction, controlled by an operator riding in a cab on the crane, which cab for the sake of simplicity is not shown. The crane A thus far described including the drive mentioned may be of any suitable conventional construction.

In addition to the bridge D, the crane A comprises a trolley F which rides on rails supported on the top of the bridge beams 10, 11 and driven by suitable power means also under control of the crane operator, so that the trolley may be moved from one end of the bridge to the other. The trolley F includes a frame which supports or carries two hoisting mechanisms, one hoisting mechanism designated generally as G, constitutes the principal load lifting mechanism and the other designated generally as K constitutes the dumping mechanism for tilting and dumping the load. The load in the embodiment shown is a ladle H. The load lift hoist mechanism G includes two sets of hoist cables connected to a double cable drum mechanism and driven by an electric motor, controlled by the crane operator, to raise or lower a grab L comprising a cross beam or spreader structure having sheaves journaled in the end thereof about which the hoist cables are reeved. The load grab L also includes a pair of hooks attached to opposite ends of the spreader which depend therefrom and pivotally engage trunnions on the load or ladle H to be hoisted.

The load tilting hoist mechanism K comprises a hoisting cable having its opposite ends connected to a cable drum driven by an electric motor controlled by the crane operator. The cable is reeved about apair of sheaves connected to a hook-like grab 16 and the center loop of the cable passes over a sheave connected to a frame supported in the crane trolley for movement toward and away from the main hoist cable drum so that the pull on the grab can be maintained substantially vertical during the dump ing of the load, which in the present instance is the ladle H. This mechanism could be like that shown in US. Patent No. 3,111,228. It should be understood that the grab 1 6 is connected to a ladle tilt bracket fixed to the ladle adjacent its bottom at the side opposite its pouring lip.

As previously mentioned in the operation of the furnace of the character referred to molten metal and scrap metal are periodically dumped into the top opening of the furnace vessel. In the arrangements disclosed, the crane A is used to transport the molten metal in a conventional ladle H from some point in the building to the furnace and to dump the molten metal into the vessel of the furnace. For this purpose the trunnions of the ladle H are engaged with the hooks f the load hoist mechanism grab L and the tilt bracket on the ladle engaged by the hook of the grab 16. The hoist mechanisms are operated to raise the ladle to the desired elevation after which the ladle is tilted about the axis of its trunnions by operating the tilt hoist mechanism K to raise the grab 16 thereof to dump the molten metal into the furnace opening.

The crane B is employed to transfer a scrap box S to the furnace and dump the scrap metal contained therein into the furnace. A number of boxes may be loaded with scrap metal and may be placed at one or more locations in the building and transported one at a time by the crane B to the furnace and the scrap metal therein dumped into the furnace. The crane B includes a bridge E comprising beams or

girders

20, 21 and a trolley M which travels on the bridge E.

The trolley M is provided with a hoist N including a hoisting cable 22 having its opposite ends connected to a cable drum driven by an electric motor and controlled by the crane operator. The cable is reeved about a pair of sheaves connected to a hook-like grab 23 and an equalizer sheave over which the center loop of the cable passes and which sheave is connected to a frame supported on the trolley for movement relative to the hoist cable drum so that pull on the grab may be maintained substantially vertical during dumping of a load. The construction for supporting the equalizer sheave for movement longitudinally along the trolley has not been shown in detail but preferably corresponds to the structure disclosed in US. Patent No. 3,111,228. The trolley M includes a support structure 24 integrally connected thereto which extends downwardly between the

girders

20, 21.

The support member 24 includes

side walls

25, 26 and

end walls

27, 28. The

side walls

25, 26 of the support member 24 include slots or

channels

30, 31, 32, 33 formed on the interiorly facing surfaces of the side walls. A carrier member R is supported between the

side walls

25, 26 by rollers carried on front and rear pairs of

trunnions

34, 35, respectively, which rollers engage and are supported on laterally extending surfaces of the slots or channels 30-33. The carrier member R is an elongate member having a generally inverted U-shaped cross section with the legs of the U forming downwardly extending sides of the carrier member and the front and rear pairs of

trunnions

34, 35 extend from the outer sides thereof. The trunnions 34 are axially aligned members which extend from sides of the carrier member at a point generally medially of the ends of the carrier and adjacent the top thereof. The trunnions 35 are axially aligned members extending from sides of the carrier member adjacent a rear end thereof and are located adjacent the ends of the downwardly extending sides or legs of the U-shaped carrier member.

The web of .the inverted U-shaped carrier member forms a top of the carrier member and supports a hoist mechanism P which is fixed on an upper surface thereof. The hoist mechanism P comprises two hoisting cables 36 which extend downwardly through

slots

38, 39 formed in the web of the carrier member R. The cables 36 have their ends fixed to the drum of the hoist N driven by an electric motor 40 which is controlled by the operator of the crane. The cables 36 are fixed at their other ends to points on the carrier member R.

The crane B is, as previously stated, employed to transfer a scrap box S to the vessel of a furnace and dump the scrap metal therein into the furnace. The scrap box S is a rectangular trough-like box 43 having one end closed and the other end provided with a discharge chute 44 for guiding or directing the scrap metal out of the end of the boxes, as the box is tilted. The box S includes axially aligned

trunnions

45, 46 projecting from opposite sides thereof adjacent the chute end thereof and which are engaged by the hook-like grabs 41 of the hoist P, and a projecting assembly 47 at the closed end of the box which is engageable by the hook of the grab 23.

The hoist P constitutes the primary load raising hoist While the hoist N constitutes the dumping mechanism for tilting and dumping the scrap box S.

In accordance with the present invention the scrap box S is raised into the carrier member, moved horizontally into a position adjacent to the opening in the furnace vessel and pivoted relative to the trolley M about an axis transverse to the length of the scrap box and which may be spaced substantially from the support structure for the scrap box. During horizontal movement of the scrap box to position it in front of the opening of the furnace vessel preparatory for dumping by movement of the trolley M along the

girders

20, 21 and the crane B along its runways, the box S is preferrably raised into engagement with the carrier member R to prevent horizontal swinging of the scrap box S.

As shown in the drawings, the scrap box S is of smaller width than the carrier member R and is elevatable relative to the trolley M so as to be positioned between the downwardly extending legs or sides of the carrier member R and with the top of the scrap box closely adjacent or engaging the Web of the carrier member. The legs or sides of the carrier member R includes

slots

48, 49 on the interiorly facing surfaces thereof which are open at the lower extremities of the sides of the carrier and snugly receive the trunnions on the scrap box and the hook-like grabs 41 of the hoist P in engagement therewith as the scrap box is raised into the carrier member. The scrap box S is held in position in the carrier member R by the hoist mechanism P.

As previously noted, the carrier member R is supported in the support structure 24 of the trolley M by rollers carried by pairs of

trunnions

34, 35 which extend from sides thereof and which rollers are engageable with laterally extending surfaces of slots 30-33 formed in the support structure. The pairs of slots in each of the

side walls

25, 26 are identical and therefore only one pair of slots will be described in detail. The

slots

31, 33, shown, include straight parallel

inclined portions

50, 51 which merge smoothly into parallel arcuate portions 52, 53. The portions 5053 of the

slots

31, 33 are inclined upwardly in the direction of the opening of the furnace vessel and the arcuate portions 52, 53 preferably form arcs of circles having a common center X which is spaced a substantial distance from the support member 24. In the preferred embodiment the center X lies on a line extending through the furnace vessel and in a direction transverse to the direction of movement of the trolley M on the

girders

20, 21. The carrier member R is normally supported in the lowermost ends of the slots 30-33 by the pairs of

trunnions

34, 35, which are freely movable in the slots 30-33.

When the scrap box S has been elevated relative to the trolley M into engagement with the carrier member R, further raising of the grab 23 of the hoist N will cause the scrap box S to urge the carrier member upwardly therewith. When the carrier member R is urged upwardly by action of the hoist N, the

trunnions

34, 35 move relative to the slots 30-33 and movement thereof is guided by the laterally extending surfaces of the slots. As the

trunnions

34, 35 are moved along the straight

inclined portions

50, 51 of the slots, the carrier member R and the scrap box S are moved as a unit upwardly and horiz-ontally relative to the support member 24. In the illustr-ated embodiment, the

inclined portions

50, 51 of the slots are constructed so that the forward end of the discharge chute 44 of the scrap box S is moved to a position just inside the opening of the furnace vessel to a point at which the center of curvature X of the arcuate portions 52, 53 of the channels is located as shown in phantom lines in FIG. 2. As the hoist N continues to urge the scrap box S and carrier N upwardly, the

trunnions

34, 35 move into the arcuate portions 52, 53 of the grooves or channels 30-33. As the trunnions '34, 35 follow the arcuate portions of the channels, the carrier and scrap box are pivoted about the center of curvature X of the arcuate portions 52, 53 to dump the scrap material contained in the scrap box S into the furnace vessel. The hoist N moves horizontally relative to the trolley M during movement of the scrap box and carrier member along the slots 30-33 to maintain the cable pull substantially vertical. When the carrier member and scrap box move along the arcuate slot portions 52, 53 and pivot about the center of curvature X, the

slots

48, 49 in the legs of the carrier member engage the grabs 41 and/or the trunnions on the scrap box to prevent the scrap box from moving relative to the carrier member toward the furnace opening. When dumping of the box S has been completed, cable is played out from the drum of the hoist N, permitting the carrier and scrap box S to move down the inclined slots 30-33 by the action of gravity and into the normal position where the

trunnions

34, 35 are supported at the lower ends of the straight inclined portions of the

slots

50, 51.

It can now be seen that an improved crane structure has been provided in which a scrap bucket is accurately moved along a predetermined path and pivotal about a point spaced from the scrap box or bucket supports to dump material contained in the scrap box into a vessel of a furnace or the like and in which movement of the scrap box during dumping thereof is controlled by the configuration of slots located in a support structure for the carrier member which permits the carrier member to be moved relative to its supporting structure. While the slots for guiding movement of the carrier member and scrap bucket as it is dumped preferably include straight inclined portions and arcuately curved portions along which the carrier member for the box is movable to effect a dumping movement of the box, and such slots have been described in detail in the preferred embodiment. It is to be understood that grooves having guiding surfaces which are different from those shown and described therein may be provided to effect any of the desired dumping movement of the box.

From the foregoing description of the preferred embodiment of the invention, it will be apparent that the objects heretofore enumerated and others have been accomplished and that there has been provided a novel and improved crane structure for use in steel mills and the like. Although the preferred embodiment of the invention has been shown and described in considerable detail, it is to be understood that the invention disclosed is not limited to the particular construction shown and described and it is our intention hereby to cover all adaptations, modifications, and uses of the invention which come within the practice of those skilled in the art to which the invention relates and within the scope of the appended claims.

Having described our invention, we claim:

1. In a material handling apparatus, an overhead movable support structure adapted to handle a material container, hoist means carried by said support structure and having depending flexible members adapted to engage a material container for changing the elevation of the container relative to said support structure from a position below and free of said support structure to a position above the lower end of said support structure, said support structure having means controlling movement of a material container supported by said flexible members at an elevated position within said support structure, said means including spaced parallel surfaces effecting pivotal and horizontal movement of the material container relative to said support structure in response to hoisting movement of said flexible means with the material container within said support structure whereby the material container is moved horizontally and pivoted to empty material therefrom.

2. In a material handling apparatus as defined in claim 1 wherein said surfaces include parallel arcuate portions having a center of curvature spaced substantially therefrom.

3. In a material handling apparatus of the type defined in claim 2 wherein said means includes a member rigidly connected to said support structure and movable therewith with said surfaces being formed in said member.

4. An apparatus as defined in claim 1 and further including a carrier member supported for movement on said surfaces relative to said support structure.

5. An apparatus as defined in claim 4 wherein said hoist means includes a hoist mechanism supported on said carrier member and movable therewith.

6. An apparatus as defined in claim 5 wherein said means including parts associated with said carrier member engageable with portions of a material container to limit movement thereof relative to said carrier member.

7. In a crane comprising a trackway, a support structure movable along said traokway and including a first hoist, a support member depending from said support structure and connected thereto for movement therewith, a carrier member supported by said support member, and including a second hoist, a material container elevatably supported by said hoists movable vertically to a position adjacent said carrier and horizontally movable with said support structure, guide means cooperable with said carrier to direct movement of said carrier along a predetermined path relative to said support member, said carrier member and said material container being movable horizontally relative to said support member and said support structure and pivotally movable relative to said support structure in response to operation of said first hoist.

8. A crane as defined in claim 7 wherein said guide means includes surfaces extending laterally from said support member supporting said carrier for movement relative to said support structure.

9. A crane as defined in claim 8 wherein said surfaces includes arcuate portions having a center of curvature spaced from said carrier member.

10. In a crane including trackway supported by a bridge structure, a trolley movable along said trackway and including a first hoist, spaced support structures depending from said trolley and connected thereto for movement therewith, a carrier member supported by parts engaging said support structures, said carrier member including a second hoist, said first and second hoists being adapted for connection to a scrap box by flexible connecting means, said scrap box movable horizontally with said trolley and vertically in response to operation of said hoists, said scrap box movable vertically into a position adjacent said carrier member, guide means cooperable with said carrier and said support structures for moving said carrier and said scrap box horizontally relative to said trolley and for pivotal movement about a center of rotation spaced substantially from said support parts, said carrier and said scrap box being pivotally movable in response to movement thereof by said first hoist whereby material in said scrap box is emptied therefrom.

11. In a crane defined in claim 10 wherein said guide means includes surfaces formed in said support structures engageable with projections on said carrier for guiding said carrier relative to said support structures along a predetermined path.

7 8 12. A crane defined in claim 11 wherein said surfaces References Cited include spaced arallel "arcuate pcrtions the center 9f UNITED STATES PATENTS curvature of which lies on the aims of rotatlon of said carrier and said Scrap bucket 570,913 11/ 1896 Donaldson 214-708 13. In a crane defined in claim 11 wherein said prog 9/1902 Hughes 214' 707 X jections on said carrier include trunnion members rigidly secured to said carrier and spaced a predetermined fixed stance from each HUGO 0. SCHULZ, Primary Examiner.