Pour Tube Latching Apparatus

This invention relates to improved apparatus for manipulating from a remote location a shroud tube that encloses the molten stream flowing from a bottom pour teeming vessel to a receiver, such as a tundish. More particularly, the invention involves a manipulator of simple, light-weight construction that can be operated by a single workman from a remote location for connecting the inlet end of a shroud tube to the discharge nozzle from a teeming vessel. The apparatus is also for imparting the compound movements necessary to extend the discharge end of the shroud tube through the limited access opening of a tundish cover.

It is desirable when pouring molten metal of certain compositions, such as aluminum-killed steels, to prevent contact of the metal with ambient air in order to protect against reoxidation of the metal. Receivers for such metals are, accordingly, usually provided with a closure cover containing an access opening of limited dimensions and shroud tubes are commonly provided to enclose the molten stream from the teeming vessel to the receiver.

Shroud tubes for such service are formed of refractory material that is subject to erosion and wear, and therefore the tubes must be periodically replaced, oftentimes, before the teeming vessel has been emptied. In such instances, it had been the practice to terminate the pour whereupon one or more workmen would manually remove the spent tube and install a new one, a practice that is both arduous and hazardous.

In U.S. Pat. No. 4,131,220, granted Dec. 26, 1978 to Bode et al and assigned to the assignee herein, there is shown and described a manipulator for shroud tubes that enables the replacement of spent pour tubes from a remote location. While such apparatus is effective for the purpose intended, it is unduly bulky in size and of complicated design. This apparatus, moreover, incorporates numerous hydraulic operators that not only add to the capital cost of the apparatus but also require ancillary sources of hydraulic power that increase the cost of operation.

It is to the improvement of such apparatus, therefore, that the present invention is directed.

According to the present invention, there is provided apparatus for mounting a shroud tube in operative relation to the pour opening in a bottom-pour teeming vessel which apparatus comprises a stationary base; a pivot saddle mounted on the base for rotation about a vertical axis thereof; open-ended journal means pivotally mounted to the saddle; an elongated arm received in the journal means and supported therein for axial and rotatable movement; means at the end of the arm for vertically suspending a shroud tube, such means including means for rotating the shroud tube about its longitudinal axis; means at the other end of the arm for manually moving the arm with respect to the journal means; and means operable from the other end of the arm for actuating the shroud tube rotating means.

It is therefore a principle object of the present invention to provide improved apparatus of simple, low-cost design for effectively connecting from a remote location a shroud tube to the pour nozzle of a bottom pour teeming vessel.

It is another object of the invention to provide apparatus of the described type that permits removal and replacement of shroud tubes with respect to the pour opening of a bottom-pour teeming vessel without disturbing other parts of the assembly and without danger to the workman.

A further object of the invention is to provide apparatus of the described type that permits operation thereof with movable discharge nozzles of sliding gate valves, or the like.

A still further object of the invention is to provide apparatus that permits ready removal and replacement of shroud tubes within the confined space between a bottom-pour teeming vessel and a closely subjacent receiver.

For a better understanding of the invention, its operating advantages and the specific objectives obtained by its use, reference should be made to the accompanying drawings and description which relate to a preferred embodiment thereof.

FIG. 1 is an elevational view of the apparatus of the present invention operatively positioned between a bottom-pour teeming ladle and a tundish;

FIG. 2 is a plan view of the apparatus of FIG. 1;

FIG. 3 is a sectional view taken along line 3--3 of FIG. 1;

FIG. 4 is a sectional view taken along line 4--4 of FIG. 1;

FIG. 5 is a partial elevational view taken through the shroud tube holder of the present invention;

FIG. 6 is a partial plan view, partly in section, illustrating the movable support and operating linkage incorporated in the invention;

FIG. 7 is an elevational representation of the movable support and operating linkage shown in FIG. 6;

FIGS. 8 and 9 are plan and side views, respectively, of the movable support; and

FIG. 10 is a plan view of the vertical support member of the apparatus.

In the drawings there is partly shown a receiving vessel, such as a tundish 10, in operative position beneath a bottom-pour teeming vessel 12. The tundish 10 includes an elongated, refractory-lined shell 14 having an upper end closed by refractory-lined cover 16. The cover 16 contains a centrally-disposed opening 18 to permit passage of a shroud tube 20. The teeming vessel 12, only part of which is shown, is a conventional ladle provided at its bottom end with a sliding gate valve 22 of known construction having a depending pour nozzle 24 that is movable in the direction of the arrow 26 to control the flow of molten metal from the ladle to the tundish. A sliding gate valve of the type shown at 22 is disclosed in detail in U.S. Pat. No. 4,063,668 granted Dec. 20, 1977 to E. P. Shapland, et al and will be described herein only to the extent necessary for an understanding of the present invention.

As shown in several of the figures, the pour nozzle 24 is provided with a pair of diametrally opposed, radially extending pins 28 that serve to attach the shroud tube 20, the latter extending from the pour nozzle into the interior of the tundish 10 in order to prevent reoxidation of the flowing metal by protecting it against contact with ambient air. The shroud tube 20 is of conventional design being formed of an elongated, generally cylindrical hollow body having at its upper end an enlarged head 30 forming a downwardly facing shoulder 32.

In accordance with the invention, there is provided an adapter 34 formed as a generally cylindrical open-ended body sized to freely receive the shroud tube head 30 which engages the adapter at the shoulder 32. The upper end of the adapter is provided with a pair of diametrally opposed bayonet slots 36 engageable with the pins 28 to attach the adapter with the retained shroud tube 20 to the pour nozzle 24 upon rotation of the adapter in a clockwise direction, as hereinafter described. As shown in FIGS. 1 and 5, the lower legs of the slots 36, indicated as 38, are inclined in a direction to impart an upward movement to the shroud tube 20 in order to bring it into sealed, seated engagement with the lower end of the nozzle 24 when the adapter is rotated clockwise.

Apparatus for attaching the shroud tube 20 to the pour nozzle 24 and for manipulating the tube for insertion of its lower end through the opening 18 in tundish cover 16 from a remote location is indicated generally as 40. In general, it comprises an elongated arm 42 containing mechanism at one end for manipulating the shroud tube 20 through the movements necessary to produce the desired result and means at the other end for manually operating the manipulating means. Specifically, the apparatus includes a base 44 here shown as being mounted on the tundish cover 16 but which may be more desirably mounted elsewhere in a fixed location. The base 44 includes a hollow, upstanding post 46 and a horizontal platform 48 having an opening aligned with the interior of the post. A pivot saddle 50 is rotatably mounted on the base, comprising a bottom plate 52 that rests on the platform 48 and a pin 54 depending from the plate 52 that is telescopically received in the post 46 for rotation therein. Attached to the bottom plate 52 are a pair of upstanding plates 56, the upper ends of which contain pivot slots 58 that operate to pivotally mount a journal bearing 60 that mounts the arm 42 for axial and rotational movement.

The journal bearing 60 is best shown in FIG. 4 and comprises an arcuate base 62 formed as a section of a cylinder having an upwardly facing opening 64 to facilitate assembly of the arm 42 therein. A pair of diametrally opposed pins 66 extend outwardly from the midpoint of the base 62 and operate to mount the member 60 in the slots 58 for pivotal movement about its lateral axis. The arm 42 is supported in the journal bearing 60 upon roller bearings 68 disposed in fixed receptacles 69 that are circumferentially spaced about the base 62 adjacent opposite ends thereof.

The arm 42 of the apparatus is an elongated tubular member which, as shown in FIG. 1, rests in the journal bearing 60 and extends from a location subjacent the pour nozzle 24 to a point remote from the ladle 12. At the operating end of the arm 42, indicated generally as 70, there are provided oppositely extending operating handles 71 to permit a workman to manually operate the apparatus. The other end of the arm 42 has fixed thereto a support yoke 72 that is open at its end to permit attachment and detachment of a shroud tube 20. A generally C-chaped tube support plate 74 rests on the upper surface of the support yoke 72, its side opening conforming substantially with that of the opening in the yoke 72. The plate 74 is adapted for rotational movement upon the yoke 72 about an axis substantially coincident with the longitudinal axis of the shroud tube 20 when mounted thereon. The path of movement of the plate 74 is guided by the cooperation between a plurality of pins 76 depending from the lower surface of the plate and an arcuate slot 78 formed in the upwardly facing surface of the yoke 72. The ends of the pins 76 are desirably threaded for reception of nuts 80 that serve to retain the plate 74 in attached relation to the yoke 72. Movement between the plate 74 and the yoke 72 can be facilitated by interposition of a lubricated shim 82, or the like, between the plate and the yoke.

The tube support plate 74 contains an integrally formed, upstanding, arcuate wall 84 containing a pair of diametrally spaced slots 86 for reception of pins 88 that extend radially from the lower end of the shroud adapter 34 thereby serving to mount the adapter and its retained shroud tube for pivotal movement about a horizontal axis upon the support plate 74. In this regard, the upper edge of the wall 84 may be provided with an arcuately formed depression 86 at its rear end to accommodate rocking movement of the shroud tube head. It will be appreciated that mounting the adapter 34 upon the support plate 74 in this manner, not only permits pivotal adjustment of the shroud tube to facilitate reception of the pour nozzle pins 28 in the bayonet slots 36 in the adapter 34 but also serves as the means for retaining the shroud tube 20 on the arm 42 as well as for imparting the rotational movement to the adapter 34 necessary to effect connection of the shroud tube to the pour nozzle 24.

Rotational movement of the plate 74 upon the yoke 72 is effected from the operating end 70 of the arm 42 by means of a fluid operated motor 92 including a cylinder 94 that is pivotally mounted in brackets 96 attached to the arm 42 within easy access to the workman. The piston operated within the cylinder 94 is connected via an elongated connecting rod 98 that is concentrically disposed within the interior of the tube 42. At its opposite end, the connecting rod attaches to a lever 100 pivotally mounted to the arm 42 by a pivot pin 102 retained in a clevis 104. The lever 100 is pin-connected at 106 to the connecting rod 98, access thereto being provided by an opening 108 provided in the wall of the tube 42. The other end of the lever 100 is connected to a finger 110 in the tube support plate by an articulated link 112. To accommodate the relative spacing between the connecting rod 98 and the finger 110, the lever 100 is conveniently offset as shown in FIG. 7.

Actuation of the fluid motor 92 is effected by a controller 114 that may be a hand-held pendant or, as shown, attached to the handles 71. The controller 114 contains switches to actuate the cylinder 94 to produce a forward and a retracted movement of the connecting rod 98. In the described apparatus, the connecting rod 98 is arranged to have a throw of approximately three inches which will produce a rotational movement in the tube support plate 74 of about twenty-two degrees. Movement of the connecting rod 94 in the forward direction will effect the clockwise rotation of the plate 74 required for engaging the bayonet connection between the adapter 34 and the pour nozzle 24. Conversely, retraction of the connecting rod 98 rotates the plate 74 in a counter-clockwise direction to disengage the bayonet connection.

The operation of the hereindescribed apparatus is as follows. With the slide gate valve 22 on the teeming vessel 12 in its closed position, the arm 42 of the apparatus 40 is manually retracted by the operator to its rearwardmost position in the journal bearing 60 and rotated about its vertical axis to place the yoke 72 and tube support plate 74 in an exposed position to receive a shroud tube 20 having the adapter 34 assembled thereon. Where, as in the illustrated arrangement, insufficient vertical spacing is available to permit the shroud tube 34 to be positioned in a vertical attitude in the yoke 72, the arm 42 is rotated about its horizontal axis within the journal bearing 60 to place the yoke and tube support plate in a position to receive the shroud tube 20 in an inclined attitude. The shroud tube 20 is thus assembled in the yoke 72 by positioning the adapter pins 88 in the slots 86 formed in the upstanding wall 84 of the tube support plate 74. The shroud tube 20 is held in its inclined position and the arm 42 rotated to move the tube to a position beneath the exposed pour nozzle 24. In moving the shroud tube 20 to its position beneath the pour nozzle the arm 42 is rotated about its horizontal axis to insert the lower end of the tube 20 through the opening 18 in the tundish cover 16 and into a vertical attitude. If required, the operating end 70 of the arm 42 can be raised through pivoting of the journal bearing 60 in the saddle 50 to lower the shroud tube 20 to a position spaced below the pour nozzle after which the shroud tube can be pivotally raised into a position whereby the pour nozzle 24 enters the adapter 34 and the pins 28 on the former enter the bayonet slots 36 on the latter. Following this the operator actuates controller 114 operating the fluid motor 92 to move the connecting rod 98 forwardly whereupon the tube support plate 74 is rotated clockwise to engage the bayonet connection between the pour nozzle 24 and adapter 34. It will be appreciated that, due to the inclination of the lower legs 38 of the slots 36, the head 30 of the shroud tube 20 will, as shown in FIG. 5, be brought into fluid tight engagement with the lower end of the nozzle.

The apparatus 40 may thereafter be disconnected from the shroud tube 20 by raising the operating end 70 of the arm 42 to lower the yoke 72 and tube support plate 74 and disengage the pins 88 from the slots 86. Fluid motor 92 is then actuated to retract the connecting rod 98 and rotate the tube support plate 74 counter-clockwise to its original position in alignment with the yoke 72 whereupon the arm can be axially retracted in the journal bearing 60 and thence rotated to an out-of-the-way position to permit teeming to commence by the opening of the gate valve 22.

The described apparatus 40 is operable to disconnect a spent shroud tube 20 from the pour nozzle 24 by simply reversing the procedural steps described above.

It will be understood that various changes in the details, materials and arrangements of parts which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.