US3737138A

US3737138A - Apparatus for locking hot tops

Info

Publication number: US3737138A
Application number: US00179693A
Authority: US
Inventors: D Gregan
Original assignee: Foseco International Ltd
Current assignee: Foseco International Ltd
Priority date: 1971-09-13
Filing date: 1971-09-13
Publication date: 1973-06-05
Anticipated expiration: 1990-06-05

Abstract

A hot top for a generally rectangular ingot mold comprising at least a pair of side boards, hanger clips for suspending the side boards adjacent the upper portion of opposite sides of the ingot mold, and locking means adapted to forcibly hold the side boards to the sides of the mold. The locking means include generally horizontal elongated members having generally perpendicularly disposed locking arms attached thereto, and adapted to interlock with one another in a manner which applies forces that hold the side boards firmly to the sides of the mold.

Description

United States Patent [191 Gregan June 5, 1973 APPARATUS FOR LOCKING HOT TOPS Inventor: Daniel P. (iregan, Cleveland, Ohio Assignee: Foseco International Limited, Birmingham, England Filed: Sept. 13, 1971 Appl. No.: 179,693

U.S. Cl. ..249/197, 29/239, 249/202 Int. Cl. ..B22d 7/10 Field of Search ..249/197, 202, 106;

References Cited UNITED STATES PATENTS Rote ..29/239 Tisdale ..249/202 X Primary Examiner-Robert D. Baldwin Atz0rneyWolfe, Hubbard, Leydig, Voit & Osann, Ltd.

[57] ABSTRACT A hot top for a generally rectangular ingot mold comprising at least a pair of side boards, hanger clips for suspending the side boards adjacent the upper portion of opposite sides of the ingot mold, and locking means adapted to forcibly hold the side boards to the sides of the mold. The locking means include generally horizontal elongated members having generally perpendicularly disposed locking arms attached thereto, and adapted to interlock with one another in a manner which applies forces that hold the side boards firmly to the sides of the mold.

7 Claims, 4 Drawing Figures PATENTED JUH 5 i975 SHEET 2 BF 2 APPARATUS FOR LOCKING HOT TOPS This invention generally relates to metal casting and, more particularly, to a hot top for casting steel in ingot form.

When the majority of molten metals are poured into an ingot mold, the first poured metal freezes against the mold wall and undergoes a density increase as it freezes so that it tends to produce a void and which is then filled by additional molten metal being poured. A molten pool in the center of the mold gradually sinks downwardly as it feeds the shrinking walls and this continues as long as the chilling effect of the mold wall is felt in the molten pool. When the effect is no longer felt, the molten metal freezes slowly throughout and shrinks downwardly, resulting in a casting with a sound wall and an axial cavity or pipe extending downwardly a considerable distance within the ingot. It is desirable that such piping be kept to a minimum so that a greater portion of the upper portion of the ingot mold need not be removed.

To prevent the upper portion of the ingot from cooling at a rate much faster than the bottom, and producing the previously described piping or shrinking, it is presently the practice to use hot tops as a means for holding the molten metal over the piping area and at the same time supplying heat or preventing heat from escaping at the top of the mold. This can be done by using hot tops. comprised of exothermic materials which supply heat to the top of the ingot, or by using materials which act as an insulator to prevent the heat of the molten metal from rapidly escaping. In the event side or liner boards of either the insulating or exothermic type are used in a hot top, it is important that they be held tightly to the sides of the mold, so that essentially no molten metal may flow between the mold and the side boards.

There have been many designs for holding side boards to the mold including such conventional devices as spring wire clips snapped over the mold wall which extend into the mold and hold the boards to the mold, or internal expanding spring loaded devices held in compression with tie wires or the like which, when the devices are in place, are cut to allow the device to expand against the boards and hold them in place. The devices must be either preloaded before they are inserted into the mold or, as in the case of the spring wire clips, they are susceptible to being sprung out during installation.

Accordingly, it is an object of the present invention to provide a hot top which is economically manufactured and easily installed.

Another object of the invention is to provide a hot top having a locking means which requires no preloading and is not susceptible to being sprung out during normal installation.

Yet another object of the present invention is to provide a hot top which includes a locking means which may be manufactured to provide a predetermined, substantially constant holding force to the side boards. A related and more specific object provides a hot top having a holding means which applies a generally uniform holding force along a substantial portion of the length of each of the side boards.

Other objects and advantages will become apparent while reading the ensuing specification and referring to the attached drawings, in which:

FIG. 1 is a perspective view of a portion of the hot top of the present invention, particularly illustrating the means for suspending the side boards adjacent the sides of the mold;

FIG. 2 is a perspective view of the hot top of the present invention, shown in position prior to being locked in place;

FIG. 3 is a perspective view of the upper portion of a rectangular ingot mold, and illustrating the hot top of the present invention as applied to an ingot mold; and

FIG. 4 is a plan view of a modification of the locking means of the present invention.

While the invention will be described in connection with preferred embodiments, it will be understood that it is not intended to limit the invention to those embodiments. On the contrary, it is intended to cover all modifications and alternative constructions falling within the spirit and scope of the invention as expressed in the appended claims. Although the hot top of the present invention is advantageously suited for use with ingot molds of the big-end-down configuration, it may also be used with molds of the big-end-up configuration as well.

In general, the hot top of the present invention utilizes means for suspending the side boards adjacent the upper portion of the interior of the ingot mold 10 and also includes locking means for forcibly holding the side boards to the inner surfaces of the respective sides thereof. Additionally, the suspending means and the locking means are coordinated to provide easy installation.

Turning now to the drawings, and particularly to FIG. 3, the upper portion of the big-end-down ingot mold 10 is illustrated in perspective and is shown together with a hot top, indicated generally at 12, of the present invention.

As is illustrated in FIG. 1, the hot top 12 of the present invention comprises at least two liner or side boards 14 adapted to be applied to opposite sides adjacent the upper portion of the mold 10. The side boards 14 may either be of the exothermic or insulating type as desired. In the event two side boards are used, it is preferred that they be of sufficient length to extend substantially across the longer dimension of the interior of the rectangular mold 10 to provide the optimum heating or insulating of the molten metal being poured into the mold.

To suspend the side boards 14 from the top of the mold a pair of hanger clips are provided, indicated generally at 16, which have an upper portion 18 that extends across the top of the ingot mold l0 and downwardly on the outside providing a hook for securing the clip. The lower portion of the hanger clip may have generally upwardly and inwardly directed tabs 20 adapted to receive and hold a portion of the locking means previously mentioned. Immediately adjacent each of the tabs, but upwardly thereof is an upwardly and outwardly directed extension 22 adapted to be inserted into an aperture 24 within the side boards 14 to thereby hold the side boards in place. As is shown in FIGS. 1-3, two hanger clips are provided for suspending each of the side boards within the mold. Although the hanger clips are preferred, it is contemplated that other means, such as an adhesive, may be used to suspend the boards adjacent the upper portion of the inside of the mold l2.

In accordance with another aspect of the invention, and referring to FIGS. 2 and 3, the locking means for holding the side boards to the sides of the mold are illustrated, and include a pair of spaced apart generally horizontal elongated members 26 extending substantially the length of each of the side boards. Attached to or integral with the elongated member 26 are at least one and preferably a pair of spaced apart locking arms 28, extending generally perpendicularly therefrom. The members as well as the arms may be fabricated from appropriately sized steel wire, such as No.3/O AWG wire, for example. The elongated members 26 are adapted to engage the upward and inwardly directed tabs 22 of the hanger clips and are thereby restrained from moving out of the desired position generally at an elevation preferably about midway between the upper and lower edges of the side boards. The locking arms 28, 30 of each of the elongated members are of two types, and are positioned opposite one another. One type of locking arm 28 of the elongated member cooperates with the other type of locking member 30 on the opposite elongated member to interlock with one another to firmly hold the side boards to the mold.

To provide the interlocking capability, the ends of the locking arms 30 have a transverse projection 32 which may be integrally formed as by bending, or may be a separately produced piece that is welded thereto. The cooperating locking arms 28 of the oppositely positioned elongated member each have an eye 34 attached thereto adapted to receive and retain the projection 32 of the locking member 30. At the outer end portion of each of the locking arms 28 is a hook 36 which is adapted to engage the locking member 30. The eye 34 is attached to the arm 28 at a predetermined distance from the elongated member so that the combined effective length of the interlocking arms is slightly greater than the distance separating the side boards. This insures that the locking arms will be slightly bowed and will exert a force holding the elongated members apart and therefore the side boards to the sides of the mold. By varying the length of the combined locking arms by either varying the length of either of the arms or by varying the distance of the eye 32 from the end of the elongated member, the effective length may be chosen to provide a fixed magnitude of force for holding the side boards to the mold. For example, the combined effective length is preferably about an inch longer than the distance separating the side boards for a conventional mold having a width of about 24 inches. As shown in FIG. 2, an additional eye 35 may be provided adjacent each of the eyes 34 to adapt the length of the combined locking arms for use with a different sized mold. It should be understood that the locking arms having the eye attached thereto are not required to be on the same elongated member, so long as the opposite cooperating member has the projection and is adapted to interlock as described.

The present invention also contemplates the easy in stallation of the locking means. By having the projections 32 of the locking arms 30 directed toward each other as shown in FIGS. 2 and 3, the elongated members are effectively attached to one another permitting each of them to be placed in the receiving tabs 22 of the hanger clips 16 and the locking means will be held in the position generally shown in FIG. 2. The installer then merely forces the hook 36 of each of the locking gated members 26 in their approximate positions while applying sufficient force leading toward engagement of the cooperating arms 28 and 30, the force being sufficient to hold the elongated members without the tabs. The installer would then merely complete engagement by securing the hook 36 on the locking arm 30.

A modification of the present invention shown in FIG. 4 also contemplates bowing or bending the elongated members 26 between the locking arms to provide a more uniform pressure to the side boards along the entire length thereof. By bending the elongated members as shown, pressure or force applied at the point of attachment of the transverse locking arms with the elongated member, effectively distributes the force more uniformly along the length of the side boards. The ends 38 of the elongated members 26 are inwardly curved as shown so that end boards similar to the side boards 14 may be held in place in the event they are desired.

Thus, it should be understood that a new and useful hot top has been shown and described that can be easily and inexpensively fabricatedfrom readily available materials that require a minimum of processing for incorporation into the hot top of the present invention.

I claim as my invention:

1. A hot top for a generally rectangular ingot mold comprising, in combination:

at least a pair of side boards;

means for suspending said side boards adjacent the upper portion of opposite sides of said rectangular mold;

locking means contacting and holding said side boards to said mold, said locking means including a pair of spaced apart elongated members, each having at least one locking arm extending generally perpendicularly therefrom, the locking arm of one elongated member cooperating with the locking arm of the other elongated member to interlock with one another to firmly hold said side boards against the sides of said mold, said cooperating locking arms being freely pivotable relative to one another so that said locking means is easily inserted into said mold prior to interlock of said locking arms.

2. A hot top as defined in claim 1 wherein the effective combined length of said cooperating opposed interlocked locking arms is slightly greater than the distance between said side boards, such that said cooperating locking arms are bowed to thereby apply a compressive force to each of said elongatedmembers.

3. A hot top as defined in claim 1 wherein one of said interlocking and cooperating locking arms has an eye attached thereto and has a hook at its outer end, the other of said cooperating arms having a transverse projection at its outer end, said projection being insertable into said eye of said one locking arm, said hook of said one locking arm being adapted to engage said other locking arm, the combined effective length of said arms being greater than the distance between said side boards, such that said interlocking arms are bowed and said one and said other arms are locked together.

4. A hot top as defined in claim 1 wherein said suspending means comprise a number of hanger clips, the top of which are adapted to extend across the width of the top of the ingot mold and extend downwardly along the outside thereof, said hanger clip having generally upward and inwardly directed tab adapted to receive and support a part of said elongated member, said clip having a means for holding said side boards.

5. A hot top as defined in claim 4 wherein at least two of said hanger clips hold each of said side boards.

6. A hot top as defined in claim 1 wherein each of said elongated members has two locking arms extending generally perpendicularly therefrom and in spaced locking members are interlocked with one another.

Claims

1. A hot top for a generally rectangular ingot mold comprising, in combination: at least a pair of side boards; means for suspending said side boards adjacent the upper portion of opposite sides of said rectangular mold; locking means contacting and holding said side boards to said mold, said locking means including a pair of spaced apart elongated members, each having at least one locking arm extending generally perpendicularly therefrom, the locking arm of one elongated member cooperating with the locking arm of the other elongated member to interlock with one another to firmly hold said side boards against the sides of said mold, said cooperating locking arms being freely pivotable relative to one another so that said locking means is easily inserted into said mold prior to interlock of said locking arms.

2. A hot top as defined in claim 1 wherein the effective combined length of said cooperating opposed interlocked locking arms is slightly greater than the distance between said side boards, such that said cooperating locking arms are bowed to thereby apply a compressive force to each of said elongated members.

6. A hot top as defined in claim 1 wherein each of said elongated members has two locking arms extending generally perpendicularly therefrom and in spaced relation relative to one another so that each of said cooperating interlocked locking arms are bowed to apply a compressive force to each of said elongated members.

7. A hot top as defined in claim 6 wherein said elongated members are generally curved toward said side board in which they are in contact along the length between the spaced apart perpendicularly extending locking arms to more evenly distribute the applied compressive force along said elongated members when said locking members are interlocked with one another.