GB2165177A - Ladle for holding molten material - Google Patents

Abstract

A ladle (12) has above its rim (24) a pair of upstanding ears (16) which in use are above the level of molten metal which can be poured from the spout (30). The outer faces of the ears have indentations (36) into which fit protrusions (44) of a gripper apparatus (14). The position of the indentations and protrusions can be reversed; they are usually non-circular, e.g. square, to avoid relative rotation. The protrusions 44 face inwardly from paired lugs (40, 41) at least one of which is adjustably secured on an elongated support (38) by screws (50) which are loosened to allow the lug to move outwards before the gripper is engaged over the ladle. The gripper is attached by holes (56) to a handling device. The ladle is made of ceramic, e.g. fused silica, to withstand molten metals; the gripper is made of metal and does not contact the molten material. <IMAGE>

Description

SPECIFICATION Ladle for holding molten material The present invention relates generally to a ladle for holding molten material. More particularly, the invention relates to a ladle of the type which can be immersed in a molten metal bath to fill the ladle with molten metal and then removed from the bath to transport the molten metal in the ladle to a desired location.

A ladle, which includes a vessel for holding molten metal, typically requires supporting apparatus in the nature of a yoke, gripper, or other structure to support, lift and transport the ladle. A ladle to which such supporting apparatus has been attached can be referred to as a ladle assembly. Frequently, a ladle assembly is used to immerse or dip a ladle into a bath of molten material to fill the ladle with molten material from the bath. The ladle is then lifted from the bath and transported to a location at which the molten material is discharged from the ladle. Filling, moving and emptying of the ladle can be accomplished manually if the ladle is small enough or by automatically-or manually-controlled handling devices. For example, in casting operations, molten material is removed from a molten bath by the ladle and poured from the ladle into a casting mold.The ladle itself, or at least those portions which come into contact with the molten material, are made of a material which resists attack and degradation by the molten material. Such ladle materials in the past have included metals and non-metallic refractory materials such as ceramic materials.

Metal ladles suffer from the drawbacks that they are expensive to manufacture and tend to degrade quickly from contact with the molten materials. The use of refractory metals and alloys for the ladle can increase the life of the ladle but at the same time increases its cost. In order to prolong the life of metal ladles, they may be lined with a non-metallic refractory material such as a ceramic. However, such known non-metallic linings are relatively thin and have to be replaced frequently. In addition, such linings did nothing to protect the exterior of the ladle when it was introduced into a molten bath.

It is highly undesirable for the molten material being handled by the ladle to contact parts of the ladle assembly which have not been conditioned or constructed for contact with the molten material.

Such contact could result in impurities being introduced into the molten material being handled and/or damage to such parts. One of the parts of the ladle assembly which in the past it was sought to protect from contact with molten material is the ladle supporting apparatus referred to above, particularly any coupling means for attaching the supporting apparatus to the ladle.

In order to ensure that such supporting apparatus and any coupling means were not contacted by the molten material being handled, complex supporting arrangements were heretofore necessary, or the ladle was filled from a bath through an opening in a lower part of the ladle. For example, the ladle disclosed in U.S. Patent No. 4,289,259 (O'Brien) includes a slot in the side of the ladle which is submerged in a molten bath to permit molten material to enter into the ladle through the slot. U.S.

Patent No. 4,074,837 (Engel) and U.S. Patent No.

3,514,018 (Petig et al.) disclose complex ladle assemblies which include moving parts for opening and closing an opening to the ladle through which molten material is introduced into the ladle. The crucible disclosed in U.S. Patent No. 2,479,641 (Ripich) includes brackets affixed to the side of the crucible which are adapted to receive a crane hook, hoisting bar or other lifting accessory. It does not appear to be feasible to use these brackets for the purpose of introducing the crucible into a molten bath and for pivoting it.

While the use of non-metallic refractory materials for ladles may be known (see, for example, the aforementioned Ripich '641 Patent and U.S. Patent No. 487,286 (Pease), so far as the applicant is aware, ladles made entirely of a non-metallic refractory material have not heretofore been used commercially. The difficulty in developing a ladle made entirely of a non-metallic refractory material relates to the brittle nature of non-metallic refractory materials.

Due to that property of the non-metallic refractory materials, supporting a ladle made of those materials such that the supporting apparatus and any associated coupling means do not come into contact with the molten material while at the same time not subjecting the brittle ladle material to potentially damaging forces during attachment of the supporting apparatus and use of the ladle has been difficult to achieve.

It is therefore an object of the present invention to provide ladle apparatus which avoids the foregoing as well as other drawbacks.

It is another object of the present invention to provide a ladle of simplified construction, particularly one adapted to be introduced into a molten bath for filling.

It is also an object of the present invention to provide a less expensive ladle, particularly one adapted to be introduced into a molten bath for filling.

It is another object of the present invention to provide a ladle made entirely of a non-metallic material which is simple in construction and which can easily be attached to a supporting apparatus or a handling device.

It is another object of the present invention to provide a ladle of simplified construction which can be introduced into a molten material bath and carry molten material without any part of a supporting apparatus contacting the molten material.

It is another object of the present invention to provide supporting apparatus for a ladle, particularly a ladle made of a non-metallic refractory material, which is simple in construction.

It is another object of the present invention to provide a ladle, particularly a ladle made of a non-metallic refractory material, and supporting apparatus therefor which are simple in construction and permit the ladle to be introduced into a molten bath without the supporting apparatus coming into contact with the material of the bath.

It is yet another object of the present invention to provide a ladle made of a non-metallic refractory material and supporting apparatus therefor which are simple in construction, in which the supporting apparatus is protected from contacting molten material carried by the ladle and or molten material in a bath into which the ladle is introduced, and in which the supporting apparatus and any associated coupling means substantially do not subject the ladle to damaging forces and torques.

The above and other objects are achieved by the invention disclosed herein.

Briefly, a ladle in accordance with the invention comprises a vessel suitable for holding a molten material which has an opening to the interior of the vessel through which molten material can be introduced into and removed from the vessel, and coupling means by which the ladle can be attached to a supporting apparatus for the ladle such that the supporting apparatus does not come into contact with molten material during filling of the ladle from a bath and handling of the ladle. The supporting apparatus and the coupling means are such as to enable attachment of the supporting apparatus to the ladle and normal use of the ladle without subjecting the ladle to damaging torques and forces.

As a result, the ladle can be made of a brittle material.

More specifically, the vessel has an upper rim which defines the opening and the coupling means extends upwardly above the upper rim. The location on the ladle of the coupling means is such that the supporting apparatus, particularly that part which is attached to the coupling means, does not come into contact with material in a molten bath when the ladle is irnmersed in the bath for filling and with material carried by the ladle during handling.

According to one embodiment, the coupling means comprise ears attached to the vessel extending upwardly above the upper rim of the vessel so as substantially to stand above the level of molten material in all functional positions of the ladle. The coupling means further includes engaging means associated with the ears which engage the supporting apparatus. Such engaging means is disposed so as to be shielded from the interior of the vessel and above the upper rim, thereby preventing any molten material splashing inside the vessel and molten material in the bath from contacting the engaging means. The supporting means includes engaging means which engages the engaging means associated with the ears, preferably so as to prevent relative rotation between the ladle and the supporting means and enables the ladle to be pivoted by the supporting means.

The vessel and the ears are preferably made of a non-metallic refractory material as a unitary, integral unit. Also, the engaging means of the ears for attaching the supporting means to the ears is preferably unitary and integral with the ears.

According to one embodiment, the engaging means of the ears and the engaging means of the supporting apparatus comprise engaging indentations and protrusions. Preferably, the engaging means associated with the ears comprises an indentation in each ear and the engaging means of the supporting means comprises protrusions which are received in respective indentations. Relative rotation between the ladle and the supporting means is preferably prevented by making the cross-sectional shapes of the indentations and protrusions engageable in the directions of pivoting of the ladle.

Preferably, two ears are provided which extend substantially parallel to each other and are oppositely disposed, and the indentations are disposed in surfaces of the ears facing away from each other, thus facing away from the interior of the vessel.

The engaging means of the ears and the engaging means of the supporting means engage to attach the supporting means to the ears without applying any substantial shear forces to the ears. In addition, the supporting means does not apply any substantial shear forces to the ears during normal use of the ladle. Rather, forces for engaging the supporting means and the ears and for causing the ladle to be supported, pivoted, dipped into a bath and otherwise moved are applied in directions substantially parallel to the longitudinal extent of the ears, i.e., in directions substantially parallel to the extension of the ears from the ladle. This is accomplished in the embodiment in which the engaging means of the ears and the engaging means of the supporting means comprise indentations and protrusions, by extending them transverse to the longitudinal extent of the ears.This causes the forces described above to be applied to the ears in directions transversely of the extending protrusions and indentations, in other words, in directions substantially parallel to the longitudinal extent of the ears as described above.

The supporting means in one embodiment comprises a gripper having depending lugs spaced apart so as to be attachable to the spaced ears, the lugs including the engaging means (e.g., protrusions) which engage the engaging means of the ears (e.g., indentations) for attaching the lugs to the ears. In a preferred embodiment of the ladle and gripper, two oppositely-disposed ears are provided which extend above the ladle upper rim substantially parallel to each other, the gripper lugs extend substantially parallel to each other, the engaging means of the ears face away from each other and the engaging means of the lugs face each other.

The gripper is preferably made of metal and the ladle, its ears and the coupling means of the ears are preferably made of a non-metallic refractory material as a unitary, integral piece.

The above and other objects, features, aspects and advantages of the present invention will be more readily perceived from the following description of the preferred embodiments thereof taken with the accompanying drawings and appended claims.

The invention is illustrated by way of example in the figures of the accompanying drawings, in which like references indicate similar parts, and in which: Figure 1 is an exploded perspective view of a ladle according to the invention and a gripper according to the invention attachable to the ladle; Figure 2 is a side view of the assembled ladle and gripper depicted in Figure 1; Figure 3 is a sectional view of the assembled ladle and gripper of Figure 2 taken along line 3-3 of Figure 2, in which full lines depict the gripper in its contracted configuration attached to the ladle and broken lines depict the gripper in its expanded configuration separated from the ladle; and Figure 4 is a sectional side view of the assembled ladle and gripper of Figure 1 partially immersed in a molten bath as the ladle is being filled.

Depicted in Figures 1-4 is a ladle assembly 10 comprising a ladle 12 and a supporting means or gripper 14 constructed in accordance with the present invention. The ladle includes coupling means in the form of upstanding ears 16, 16 to which the gripper 14 is removably attachable. The ladle 12 can be suspended or supported by the gripper 14 which is adapted to be attached to a handling device (not shown). By means of the gripper 14, the ladle can be introduced into a molten metal bath 18 (Figure 4), filled with molten metal and transported to a location where the molten metal may be poured from the ladle.

The ladle 12 is configured as a vessel having an opening 20 (Figure 1) defined by an upper rim 24 of the vessel. The ladle 12 can take any convenient shape suitable for holding a molten material. In the embodiment depicted in the drawings, the vessel includes a generally circularly-shaped bottom 26 and upwardly and outwardly extending sidewalls 28 terminating in the rim 24. The sidewalls 28 form an arcuately cross-sectional vessel having a forward section designated 30 and a rear section designated 32. The forward section 30 includes a gently vertexed portion 34 which is configured to form a pouring spoutforthe ladle. The vessel configuration depicted in the drawings and described above is not intended to be a limitation on the invention and other vessel configurations may be utilized.The ears 16, 16 extend upwardly from the sidewalls above the upper rim 24, and are located above the level of the molten metal in the bath 18 when the ladle is introduced therein (Figure 4) and above the level of any molten metal carried in the ladle. In other words, the ears 16, 16 are always above the level of molten metal contacting the ladle 12 in all functional positions of the ladle. The ears 16, 16 are extensions of the sidewalls and are unitary and integral with the sidewalls. The sidewalls in the vicinity of transition into the ears are thickened (Figure 3). The thickness of this transition as vvell as the thickness of the ears themselves will be determined by the particular ladle material used, the size of the ladle and the use to which it will be put.

Engaging means in the form of indentations 36,36 are provided in the sides of the ears for attaching the gripper to the ears. The indentations 36,36 face away from the interior of the vessel, and for two oppositely disposed ears, as depicted in the drawings, are disposed in the sides of the ears facing away from each other. The indentations 36, 36 do not extend through the ears, but rather terminate in the interior of the ears and are in the nature of blind holes.

The gripper 14 is configured generally as a bracket having an elongate central portion 38 and spaced depending lugs 40, 41. The elongate portion 38 includes an upstanding centrally-disposed flange 42 which provides rigidity to the elongate portion. Each of the lugs 40,41 includes a protrusion 44,44 which is shaped to engage a respective indentation 36,36 in the ears. In the embodiment depicted in the drawings in which the ears 16, 16 are oppositely disposed and extend parallel to each other, the lugs 40,41 extend parallel to each other and the protrusions 44,44 are on the sides of the lugs facing each other. The indentations 36,36 and the protrusions 44, 44 comprise an interlocking structure referenced generally by reference numeral 46 in Figure 3 for attaching the gripper to the ladle.The size of the indentations 36, 36 and the protrusions 44, 44 is such that the protrusions support the weight of theWladle 12 when filled and apply sufficient force to the ladle to submerge it in the bath. At the same time, the gripper 14 and the ears 16, 16 are engaged to prevent relative rotation between the ladle 12 and the gripper 14. This is accomplished in the embodiment depicted in the drawings by the engaging configuration of the indentations 36,36 and protrusions 44,44, which, as shown, have a non-circular cross section which may be of a polygonal, preferably rectangular, cross section.

In order to affix the gripper 14to the ladle 12, at least one of the lugs 40,41 is made adjustable with respect to the other lug. In the embodiment depicted in the drawings, lug 40 is adjustably affixed to the central portion 38 by screws 50, 50. For this purpose, the central portion 38 of the gripper 14 includes two slotted holes 52, 52 adjacent an end thereof and lug 40 includes two tapped holes 54, 54 in the top thereof registering with the slotted holes 52, 52. The opposite lug 40 of the gripper 14 is not made adjustable, although it could be, and is rigidly affixed to the central portion 39.To attach the gripper 14to the ears 16, 16 of the ladle, the screws 50,50 are loosened and the lug 40 is moved outwardly so the screws engage the extreme outer edge of the slotted holes 52, 52, as depicted by the broken lines in Figure 3. Assuming that the gripper 14 is connected to a handling device and that it is more convenient to move the ladle 12 rather than the gripper 14, the ladle 12 is moved in position adjacent to and below the gripper 14 with the ears 16, 16 of the ladle between lugs 40,41 of the gripper 14. Thereafter, the ladle 12 is moved to insert the protrusion 44 on the non-adjustable lug 41 into the indentation 36 in the ear 16 adjacent that lug. Finally, the adjustable lug 40 is moved to insert its protrusion 44 into the indentation 36 of the ear 16 adjacent that lug and the screws 50, 50 tightened.

The ladle 12 can and is preferably made of a non-metallic refractory material, preferably a ceramic material. One problem in fabricating the ladle entirely out of a ceramic or other brittle material is attachment of a gripper to the ladle so that the ceramic material is not unduly stressed either directly by the gripper by virtue of its attachment or by forces and torques generated during normal use, while at the same time preventing the gripper from coming into contact with the metal bath when the ladle is introduced therein and preventing the gripper from being contacted by any molten metal in the ladle which may splash during movement of the ladle.

The gripperfear arrangement described herein solves this problem and provides three significant advantages. First, substantially no shear forces are applied to the ears during attachment of the gripper and during use of the ladle assembly. Second, the ears allow the gripper to be attached to the ladle above the rim. Third, the ears shield the depending lugs 40,41 of the gripper from the interior of the ladle. These advantages are described more fully below.

The gripper described herein does not exert any substantial forces on the ladle transverse to the ears, i.e., in a direction transverse to the extension of the ears from and the connection of the ears to the ladle, either during assembly of the gripper 14to the ladle or during normal use of the ladle. Such transverse or shear force directions are referenced generally in Figure 1 by arrow 60 and generally lie in a horizontal plane for the upright ladle depicted in Figure 1.

Rather, essentially all of the forces are exerted substantially parallel to the longitudinal extent or elongate plane of the ear, i.e., substantially parallel to the plane in which the ears are connected to the ladle. These force directions are referenced generally by arrows 62 in Figure 1 and generally lie in a vertical plane for the upright ladle depicted in Figure 1.This is accomplished by providing engaging structure on the ears and gripper such as the protrusions 44 and the indentations 36 which apply forces to the ears generally in the plane of the ear when the ladle is lifted, lowered, pivoted and moved.

During attachment of the gripper to the ladle, essentially no forces need be applied to the ears since it is essentially only necessary to move the ear and gripper structure into engaging contact, i.e., insert the protrusions 44 into the indentations 36, and lock the lug 40. The gripper- ear arrangement described herein allows the ladle to be forced into the bath, pivoted, lifted and transported without substantially applying the transverse forces described above to the ears. Thus the ladle and ears can be, and preferably, are made of a non-metallic refractory material such as ceramic.

As discussed above, the ears extend above the upper rim 24 of the ladle and the indentations 36,36 in the ears 16, 16 face away from the interior of the vessel. In order for the protrusions 44, on the lugs 40, 41 to engage the indentations 36,36, the lugs 40, 41 extend along the sides of the ears 16, 16 facing away from the interior of the vessel, as depicted in Figure 3. As also discussed, the indentations 36,36 do not extend through the ears and are disposed above the ladle rim 24. As a result, the ears position the gripper above the level of molten material in the ladle and at the same time shield the lugs from the interior of the vessel so that any splashing of molten metal in the vessel will not contact the lugs.

The material of which the ladle is made will depend on its intended use. For example, a ladle made from fused silica can withstand temperatures up to 2,000 F. and can therefore be used in a die casting operation with a number of metals and alloys such as aluminum (melting point of 1,2000 F.) and alloys of zinc, aluminum and copper which have melting points below 2000 F. A ladle made from alumina or zirconia, for example, can withstand higher temperatures and can be used in steel casing operations.

The gripper 14 can be provided with structure to enable itto be attached to a handling device. In the embodiment depicted in the drawings, three holes 56 are provided in the non-moveable lug 41 for this purpose. The flange 42 is also preferably connected to the lug 41 to provide more support for the central portion 38 when the bracket is supported at one end by the lug 41. Other structure for attaching the gripper 14to a lifting device can also be used.

As a result of the upstanding ears and the interlocking arrangement, the gripper can be quite simple, lightweight and easily coordinated with a manual or an automated handling device. An allceramic ladle is disposable, particularly because of its low cost. The gripper/ladle arrangement disclosed herein enables easy replacement of expended ladles.

It should be understood that while ladles and supporting means for the ladles have been described herein in connection with non-metallic ladles, it is not intended to limit the invention to non-metallic ladles, as the invention disclosed herein is also applicable to metallic ladles and ladles made of other materials.

It should also be understood that engaging configurations and arrangements other than those specifically shown can be used for preventing relative rotation between the ladle and gripper. For example, the indentations and protrusions may be of a rotationally non-engaging configuration such as circularly cross-sectioned, and other structure can be provided to prevent relative rotation between the gripper and the ladle. Where a configuration of the protrusions and indentations does not prevent such relative rotation, the gripper and the ears may be configured so that portions of the ears and gripper (other than the indentations and protrusions) engage to prevent relative rotation between the two.

For example, the ear itself (e.g., the top of the ear) can be engaged with a part of the gripper such as the bottom of the elongate portion 38. Alternatively, more than two ears can be provided or the ears can be located so as to prevent relative rotation between the gripper and the ladle.

One embodiment of engaging means disclosed herein utilizes protrusions and indentations. It is not intended, however, that the engaging means be so limited as other engaging structure can be utilized.

Moreover, indentations and protrusions are used herein in a broad sense and include recesses, receptacles, sockets and the associated engaging structure.

As will be apparent to those skilled in the art, changes such as those described above and others can be made to the embodiments disclosed herein, and the invention may be embodied in forms and used for purposes other than those specifically described herein.

Claims (25)

1. A ladle for holding molten material and adapted to be introduced into a molten bath for receiving molten material from the bath, transport ing the molten material and pouring the molten material at a desired location, comprising a vessel for holding the molten material, the vessel having an upper rim defining an opening into the vessel, and means extending upwardly from the upper rim for coupling supporting apparatus to and in engage ment with the ladle such that the ladle can be supported, lifted, pivoted and introduced into the bath to submerge at least part of the ladle upper rim in the bath by means of the supporting apparatus without the supporting apparatus coming into con tact with the molten material of the bath.

2. The ladle according to claim 1 wherein the coupling means includes a longitudinal extent ex tending above the upper rim of the ladle and the coupling means includes engaging means posi tioned in said longitudinal extent engageable by the supporting means so as to couple the supporting means to the ladle without the application of any substantial forces to the coupling means transverse to the longitudinal extent thereof.

3. The ladle according to claim 2 wherein the coupling means comprises spaced ears including said longitudinal extent extending upwardly from the ladle upper rim.

4. A ladle according to claim 3, wherein the ears and the vessel constitute an integral, unitary structure.

5. A ladle according to claim 3 or 4, wherein the vessel and the ears are made of a non-metallic refractory material.

6. A ladle according to claim 3,4 or 5, wherein the engaging means comprises structure integral with the ears.

7. A ladle according to claim 6, wherein said structure comprises an indentation or protrusion in each ear extending transversely of the ear and shaped to receive a correspondingly-shaped structure of the supporting apparatus so as to prevent relative rotation between them.

8. A ladle according to claim 7, wherein the indentations or protrusions are shaped to engage the correspondingly-shaped structure of the sup porting apparatus so as to prevent relative rotation between them.

9. A ladle according to claim 7, 8 or 9, wherein the ears extend substanilally parallel to each other and are oppositely disposed, and the indentations or protrusions are disposed in surfaces of the ears facing away from each other.

10. A ladle according to claim 8, or 9, wherein the cross-sectional shape of the indentations or protru sions is non-circular.

11. A ladle according to claim 10, wherein said cross-sectional shape is polygonal.

12. A ladle as claimed in claim 1, substantially as herein before described with reference to the draw ings.

13. The combination of the ladle according to any of claims 3 to 12 and supporting apparatus, wherein the apparatus comprises a gripper having a pair of depending lugs spaced apart so as to be attachable to the spaced ears, the lugs including engaging means cooperating with the engaging means of the ears for coupling the lugs to the ears.

14. A combination according to claim 13, wherein the lug engaging means and the ear engaging means are configured so as to transmit forces to the ears only in directions generally parallel to the longitudinal extent of the ears.

15. A combination according to claim 13 or 14, wherein the ear and lug engaging means comprises engaging structure on the ears and on the lugs which prevents relative rotation between them.

16. The combination according to claim 15, wherein the engaging structure comprises an indentation and a mating protrusion, each ear having either an indentation or a protrusion and the corresponding lug having either a protrusion or an indentation, respectively, the indentations and protrusions extending transversely of the ears when the gripper is attached to the ladle.

17. A combination according to claim 16, wherein the gripper includes means for adjusting the spacing between the lugs, whereby the spacing between the lugs may be changed to prevent engagement and disengagement of corresponding protrusions and indentations.

18. A combination according to claim 17 dependent on claim 9, 10 or 11, wherein the lugs extend substantially parallel to each other, and the engaging structure of the ears faces away from each other and the engaging structure of the lugs faces each other.

19. A combination according to any of claims 13 to 18, wherein the gripper is made of metal.

20. A combination as claimed in any of claims 13 to 19, wherein the ladle and gripper are engageable so that the ladle can be introduced into the bath with at least a portion of the rim submerged in the molten metal of the bath without the gripper and the engaging means coming into contact with the molten material of the bath.

21. A combination as claimed in any of claims 13 to 20, wherein the gripper includes means for adjusting the spacing between the lugs whereby this spacing may be changed to permit engagement and disengagement between corresponding protrusions and indentations.

22. A combination according to any of claims 13 to 22, wherein the indentations are disposed in the ears and the protrusions extend from the lugs.

23. A combination according to claim 22, wherein the lugs extend substantially parallel to each other.

24. A combination according to any of claims 13 to 23, wherein the gripper comprises an elongate member and a pair of oppositely disposed, spaced lugs depending from the elongate member, means permitting movement of at least one of the lugs for adjusting the spacing between the lugs, and means locking the at least one lug at a desired position.

25. A combination of ladle and supporting apparatus substantially as hereinbefore described with reference to the drawings.