US3297170A

US3297170A - Furnace charger crane

Info

Publication number: US3297170A
Application number: US434394A
Authority: US
Inventors: Ross B Mccready; Klaus W Forster
Original assignee: Kerma Corp
Current assignee: Kerma Corp
Priority date: 1965-02-23
Filing date: 1965-02-23
Publication date: 1967-01-10
Anticipated expiration: 1984-01-10

Description

Jan- 1967 R. B. MCCREADY ETAL 3,

FURNACE CHARGER CRANE Filed Feb. 23, 1965 3 Sheets-Sheet l w I O v u- KMT i u} z; a s

z A INVENTORS R055 8. MC CREADY BY KLAUS w. FORSTER ATTORNEYS Jan. 10, 1967 R. B. M CREADY ETAL 3,297,170

FURNACE CHARGER CRANE Filed Feb. 23, 1965 3 Sheets-Sheet 5 wawigmmzmmg imiizinllk g s v-6l INVENTORS ROSS B. MC CREADY H64 BYKLAUS w. FORSTER ATTORNEYS United States Patent 01 3,297,170 FURNACE CHARGER CRANE Ross B. Vicilready, Alliance, and Klaus W. Forster,

Brecksvilie, Ohio, assignors to Karma Corporation, Alliance, Ohio, a corporation of Ohio Filed Feb. 23, 1965, Ser. No. 434,394 4 Claims. (Cl. 212l4) The present invention relates to cranes and more particularly to overhead traveling cranes especially designed for charging materials into basic oxygen furnaces and 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 vessel of 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. The scrap metal is usually dumped into the furnace by ground supported equipment which transports the scrap metal to the furnace in rectangular boxes or like containers from which it is dumped into the furnace. To a limited extent scrap metal boxes have been transported to and from the furnace and their contents dumped into the furnace by overhead crane equipment similar to that used for handling the ladles of molten metal. This procedure, however, has not been satisfactory because the movements of the crane incidental to moving the scrap box to the furnace causes the box to swing which prevents quick and ready alignment of the box with the furnace, and in dumping the box, the shift of the weight of the scrap further causes undesired swinging of the box. To charge the furnace with scrap metal using conventional overhead crane equipment is a relatively slow procedure and requires considerable skill and care on the part of the crane operator. As a result, it has been conventional to install relatively heavy ground supported equipment for handling the scrap metal charging, which equipment is expensive to install and maintain and occupies valuable working space.

One of the principal objects of the present invention is the provision of a new and improved overhead crane particularly designed for handling scrap boxes and by use of which loaded scrap boxes can be quickly transported to a furnace of the type referred to above, accurately aligned with the furnace vessel in dumping position and the scrap contained therein dumped in the furnace.

Another of the objects of the present invention is to provide a new and improved overhead crane comprising a movable trolley having cable type hoist means for sup porting and dumping a load, which trolley comprises structure depending therefrom arranged to receive the cable suspended load when the load is hoisted to a given elevation and prevent or control lateral movement of the load during maneuvering of the trolley to bring the load to a predetermined position and/ or during the dumping of the load.

Other objects and advantages of the invention will be ap parent from the following description of preferred embodiments thereof, reference being made to the accompanying drawings in which:

FIG. 1 is a fragmentary side elevational view, with parts broken away, of a two crane installation embodying the present invention for dumping molten metal and scrap metal into a basic oxygen furnace, the vessel of which is shown in phantom lines;

FIG. 2 is a fragmentary view, with parts broken away, of a portion of the crane, herein sometimes referred to as the scrap box crane, shown in FIG. 1 with the load in an elevated position;

"ice

FIG. 3 is a sectional view of the crane shown in FIG. 2 with the load in the elevated position approximately on the line 33, with parts broken away;

FIG. 4 is a sectional view approximately on the line 4-4 of FIG. 3;

FIG. 5 is a fragmentary side view similar to FIG. 2 showing another embodiment of the invention, and

FIG. 6 is a sectional view approximately on the line 6-6 of FIG. 5 with parts brokenaway.

Referring to the drawings, the installation illustrated comprises two overhead traveling bridge type cranes A, B adapted for charging the vessel C shown in phantom lines, of a basic oxygen furnace with molten metal and scrap metal. The furnace and cranes are located in a building, not shown, and the bridges D, E of the crane A, B, respectively, are supported on and travel from one location in the building to another along the same runway comprising widely separated 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

14, 15 connected to end trucks supported by flanged wheels on the rails of the crane runway. The bridge is moved along the crane runway by driving mechanisms 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, such as the bridge type cranedescribed in United States Patent No. 3,095,829.

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

14 and 15, respectively, and driven by suitable power means, also under the control of the crane operator, so that the trolley can be caused to move from one end of the bridge to the other. The trolley F shown is identical with the trolley shown in United States Patent No. 3,111,228 and includes a frame 20 which supports or carries two hoisting mechanisms, one designated generally as G constitutes the principal load lifting mechanism, which load in the embodiment shown is a ladle L and the other designated generally as H constitutes the dumping mechanism for tilting and dumping the load or ladle. The load lift hoist mechanism G shown has two sets of hoisting cables connected to a single cable drum mechanism extending transversely of the length of the crane bridge and driven by an electric motor, controlled by the crane operator, to raise or lower a load grab 26 comprising a cross beam or spreader structure 27 having pulleys jou'rnaled in the ends thereof about which the hoist cables are reeved, and a pair of hooks 30 attached to opposite ends of the spreader and depend therefrom for pivotally engaging trunnions on the load or ladle L to be hoisted.

The load tilting hoist mechanism H comprises a hoisting cable 33 having its opposite ends connected to a cable drum driven by an electric motor controlled by the crane operator. The cable 33 is reeved about a pair of sheaves connected to a hook-like grab 38 and the center loop of the cable passes over a sheave connected to a frame supported in the crane trolley for movement towards and from the main hoist cable drum so that the pull on the grab can be maintained substantially vertical during the dumping of the load, which in the present instance is the ladle L. It being understood that the grab 38 is connected to the ladle tilt bracket 39 connected to the ladle adjacent to its bottom at the side opposite its pouring lip. As previously mentioned, the trolley F illustrated is, in construction and operation, like that shown and described in United States Patent No. 3,111,228. It is to be understood, however, that other trolley arrangements may 3 be employed, for example, that shown in United States Patent No. 1,430,009.

The crane B illustrated including its trolley K, which travels on the bridge B comprising the beams or girders 40 and 41, is similar in construction and operation to the crane A except that the trolley is longer in the direction of its travel on the bridge so as to space the load lift hoist and the load tilting hoist mechanisms M and N farther apart because the load to be handled, that is, the scrap box S is longer lengthwise of the bridge than the ladle L. It is to be understood, however, that the scrap box may be shorter or in fact longer than the box S shown, as desired. The lengthening of the trolley K is preferably accomplished in such a manner that the movable member 42 which carries the sheave about which the center loop of the cable 43 is reeved can move proportionately further than the corresponding member of the trolley F. The only other difference between the trolleys F and K is the inclusion in the trolley K of means for receiving the load lift grab and/ or the trunnions of the load and holding them against lateral movement when the load has been raised to a predetermined position, which position in the present instance, is that required for dumping the scrap in the scrap box S into the furnace vessel C.

As previously mentioned in the operation of a furnace of the character referred to, molten metal and scrap metal are periodically dumped into the top opening of the furnace vessel and in the arrangements disclosed, crane A is used to transport the molten metal in a conventional ladle L from some point in the building to the furnace and dump the metal in the vessel of the furnace. For this purpose the trunnions of the ladle are engaged in the hooks 30 of the hoist mechanism G and the tilt bracket 39 engaged by the grab 38. Both 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 raising the brab 38 carried by the cable 33 to dump the metal into the furnace opening.

The crane B which includes the trolley is employed to transfer the scrap boxes S to the furnace and dump the scrap metal therein into the furnace. A number of boxes may be loaded with scrap metal in one or more locations in the building and transported one at a time by crane B to the furnace and the scrap therein dumped into the furnace. Box S is a rectangular trough-like box having one end closed and the other end provided with a discharge chute 50 for guiding or directing the scrap metal out of the end of the box as the box is tilted in the manner shown in phantom lines in FIG. 2. The box S has a pair of axially aligned

trunnions

51 and 52 projecting from opposite sides and adjacent the chute end thereof to be engaged by the

hooks

54 and 55 of the grab 56 and a projecting assembly 57 on the opposite or closed end of the box to be engaged by the grab 58. As previously stated the hook spacings of

grabs

56 and 58 are duplicates of the hook spacings of

grabs

27 and 38 of the crane A.

When scrap boxes of the character referred to are handled by cranes, such as the crane A shown, as previously stated, the acceleration and deceleration of the bridge and trolley in moving the boxes to the furnace cause the suspended box to swing which prevents ready alignment of the discharge chute of the boxes with the furnace opening, and after a box has been aligned with the furnace, the tilting thereof and the fiow of the scrap therefrom shifts the weight suspended by the cables which tends to and usually does, swing the box out of alignment with the furnace. To overcome these difiiculties, the trolley K has a guide structure P attached thereto and projecting downwardly therebelow to receive the ends of the spreader 56 and the

hooks

54 and 55 when the grab is raised a predetermined distance and which guide structure positively prevents lateral movements of the hooks and consequently the suspended scrap box carried thereby when the hooks are positioned therein.

When the grab is in its elevated position in which the lower ends of the hooks are received in the guide structure, the scrap box moves exactly in accordance with the movements of the bridge and/ or trolley and the crane operator may quickly align the discharge chute of the box with the furnace opening, and the alignment will be maintained throughout the scrap dumping operation.

Guide structure P shown comprises two

members

60, 61 which may be castings or weldments welded or otherwise secured to and projecting downwardly from the trolley frame adjacent to opposite sides thereof. In the embodiment shown both upper ends of the

members

60 and 61 as viewed in FIG. 1 are connected by

integral webs

62, 63 and 64 for stability purposes. The

guide members

60 and 61 comprise inwardly facing vertical grooves or

channels

65 and 66, respectively, extending to their lower ends adapted to receive the ends of the spreader structure 56 and the

hooks

54 and 55. The guide members confine the ends of the grab including the

hooks

54 and 55 when the grab is raised to engage within the

channels

65, 66 and prevent movement thereof and the scrap box S relative to the trolley in all directions except vertically. Preferably, the lower portions of the openings or

channels

65 and 66 in the guide members are bevelled to facilitate entry of the grab thereinto.

The distance that the guide structure for the grab extends below the trolley depends upon the distance from the trolley to the point about which the scrap box is pivoted in dumping its contents into the furnace vessel. While in the preferred embodiment of the invention shown the ends of the spreader 56 and the

hooks

54 and 55 are received in the

channels

65 and 66 of the guide structure K with very little clearance, preferably about one-half inch, on each of the three sides of the channels, it will be apparent that it would be merely necessary to confine the lower end of the

hooks

54 and 55 or in fact merely the trunnions of the scrap box because the scrap box pivots during dumping about the longitudinal axis of the trunnions. The crane B can also be used expeditiously to transport and dump the ladle L and when so used the ladle trunnions will be confined in the same manner as are the trunnions of the scrap box S.

While in the preferred embodiment a spreader type grab is employed with the principal hoist mechanisms it is to be understood that the spreader could be eliminated and the hooks of the grab directly attached to the pulley blocks on the lower end of the cables and the cables rearranged on the main hoist drum so that the hooks would enter the channels in the guide structure and be restrained thereby against lateral shifting.

FIGURES 5 and 6 show a modification of the trolley K shown in the preferred embodiment wherein lower sheaves of the hoist cable means 70 and 71, corresponding with the main hoist cable means of the preferred embodiment are directly connected to one-piece hooks 72 and 73, respectively, appreciable lengths of which are confined in the guide structure R depending from the trolley. The guide structure R is in all essential respects similar to the guide structure P of the preferred embodiment, and comprises

side members

75 and 76 having

vertical channels

77 and 78 therein within the lower ends of which the upper ends of the

hooks

72 and 73 are received when the load is elevated to dumping position.

The scrap box T, shown in FIGURES 5 and 6, is similar to the scrap box S except that the

trunnions

80 and 81 are connected thereto by brackets 82 and 83, respectively, instead of being directly connected to the box proper. This construction is employed so that when the box T is dumped it will not engage the downward projecting ends of the

side members

75 and 76 of the guide structure R. The trunnions could be connected directly to the scrap box, if desired, and other parts of the apparatus modified to permit dumping of the box. It will be noted that in the embodiment shown in FIGURES 5 and 6 the trunnions and the box, when the box is elevated to dumping position, are below the lower ends of the

side members

75 and 76 of the guide structure R. Alternatively, the hooks proper could be pivotally connected to pulley blocks having the lower sheaves of the cable means 70 and 71 connected thereto. In this event it would be necessary or desirable to have the dumping elevation of the load such that the lower ends of the hooks would be confined within the guide channels of the guide structure R.

The tilting hoist mechanism employed in the embodiment shown in FIGURES 5 and 6 is a duplicate of that forming a part of the trolley K of the preferred embodiment and the duplicate parts are designated by the same reference characters.

It will be apparent from the foregoing that the present invention provides a traveling overhead crane that can be employed to expeditiously charge scrap metal into a furnace thereby eliminating the necessity of providing ground supported equipment for this purpose. The crane B shown can also be used for expeditiously transporting and dumping ladles. The crane A can be omitted from the installation if desired and the crane B employed for both charging operations. Alternatively, both trolleys may be made similar to trolley K in which event either crane would be available for either operation which would be advantageous in the event of a breakdown of one of the cranes.

From the foregoing description of the preferred embodiments 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 overhead apparatus for use in steel mills and the like which not only does not occupy valuable floor space but which can be used to quickly change molten and/ or scrap metal into a furnace thus saving valuable furnace operating time which would be othe lost.

Although the preferred embodiments of the invention have been shown and described in considerable detail, it is to be understood that the invention disclosed is not limited to the particular constructions shown and described, and it is the intention to hereby 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 the scope of the appended claims.

Having described our invention, we claim:

1. In a crane having an overhead bridge, a crane trolley movable along said bridge and including depending members forming guide means, auxiliary hoist mechanism on said trolley comprising auxiliary hoist flexible cable means, auxiliary load grab means adapted to be detachably connected to a load, said auxiliary load grab means being connected to said auxiliary hoist cable means, main hoist mechanism comprising main hoist flexible cable means, and main load grab means adapted to be detachably connected to a load, said main load grab means being connected to said main hoist cable means and movable vertically between a position below and free of said guide means for connection to a load and a position above the lower end of said guide means for moving and discharging a load while suspended from said trolley by said main and auxiliary cable means, said guide means being operative to restrain lateral movement of a load carried by said main and auxiliaty load grab means when said main grab means is elevated to a position above the lower end of said guide means, said auxiliary load grab means being vertically movable relative to said trolley independently of said main load grab means.

2. In a crane, a trolley movable along an overhead trackway and comprising a frame including depending guide means providing generally vertical guideways, auxiliary hoist mechanism on said trolley comprising auxiliary hoist flexible cable means, auxiliary load grab means adapted to be detachably connected to a load, said auxiliary load grab means being connected to said auxiliary hoist cable means, main hoist mechanism on said trolley comprising main hoist flexible cable means, and main grab means adapted to be detachably connected to a load operatively connected to said main hoist cable means and movable vertically between a position without and clear of said guide-ways for connection to a load, and to a position within said guide-ways for moving and discharging a load while suspended from said trolley by said main and auxiliary cable means, said guide means being operative to prevent lateral movement of a load relative to said trolley suspended therefrom by said main and auxiliary cable means when said main grab means is within said guide-ways, said auxiliary load grab means being vertically movable relative to said trolley independently of said main load grab means.

3. In a material handling apparatus as defined in claim 1 wherein said guide means comprise generally vertically extending, spaced channel-like guide-ways facing one another formed in said guide means depending from said trolley.

d. In a material handling apparatus as defined in claim 2 in which said grab means are hook-type grabs detachably engageable with projections on said load, said projections engageable with said main grab means having portions movable into said guide means.

References Cited by the Examiner UNITED STATES PATENTS 1,362,560 12/1920 Coe 212 1,558,746 10/1925 Moore 212-430 3,034,659 5/1962 Willison et al. 2l2--14 3,111,228 11/1963 Anderson 212l30 ANDRES H. NIELSEN, Primary Examiner.

EVON C. BLUNK, Examiner.

A. L. LEVINE, Assistant Examiner.

Claims

1. IN A CRANE HAVING AN OVERHEAD BRIDGE, A CRANE TROLLEY MOVABLE ALONG SAID BRIDGE AND INCLUDING DEPENDING MEMBERS FORMING GUIDE MEANS, AUXILIARY HOIST MECHANISM ON SAID TROLLEY COMPRISING AUXILIARY HOIST FLEXIBLE CABLE MEANS, AUXILIARY LOAD GRAB MEANS ADAPTED TO BE DETACHABLY CONNECTED TO A LOAD, SAID AUXILIARY LOAD GRAB MEANS BEING CONNECTED TO SAID AUXILIARY HOIST CABLE MEANS, MAIN HOIST MECHANISM COMPRISING MAIN HOIST FLEXIBLE CABLE MEANS, AND MAIN LOAD GRAB MEANS ADAPTED TO BE DETACHABLY CONNECTED TO A LOAD, SAID MAIN LOAD GRAB MEANS BEING CONNECTED TO SAID MAIN HOIST CABLE MEANS AND MOVABLE VERTICALLY BETWEEN A POSITION BELOW AND FREE OF SAID GUIDE MEANS FOR CONNECTION TO A LOAD AND A POSITION ABOVE THE LOWER END OF SAID GUIDE MEANS FOR MOVING AND DISCHARGING A LOAD WHILE SUSPENDED FROM SAID TROLLEY BY SAID MAIN AND AUXILIARY CABLE MEANS, SAID GUIDE MEANS BEING OPERATIVE TO RESTRAIN LATERAL MOVEMENT OF A LOAD CARRIED BY SAID MAIN AND AUXILIARY LOAD GRAB MEANS WHEN SAID MAIN GRAB MEANS IS ELEVATED TO A POSITION ABOVE THE LOWER END OF SAID GUIDE MEANS, SAID AUXILIARY LOAD GRAB MEANS BEING VERTICALLY MOVABLE RELATIVE TO SAID TROLLEY INDEPENDENTLY OF SAID MAIN LOAD GRAB MEANS.