US2377732A - Apparatus for casting metal ingots - Google Patents

Description

June 5, 1945. wis. WALKER 2,377,732

APPARATUS FOR CASTING METAL INGOTS I Filed June 9, 1945 s Sheets-Sheet 2 William 8 Wn/ Irer y nvenror 1 A44 V m M M June 5, 1945. w, a WALKER 2,377,732

APPARATUS FOR CASTING METAL INGOTS Filed June 9, 1945 5 Sheets-Sheet a Patented June 5, 1 945 V I h I UNITED STATES PATENT -OF'FlCE APPARATUS FOR CASTING METAL INGOTS William Shelley Walker, Hope, England, assignor to Thos. Firth & John Brown Limited, Sheflield,

Yorkshire, England, a British company Application June 9, 1943, Serial No. 490,165 In Great Britain July 8, 1942 1 Claim.

' means of bringing this about is to maintain during the filling of the mould an approximately constant but small height ot fall of the metal from the filling spout on to the liquid metal surace.

The above requirement is fulfilled in apparatus of the type (hereinafter referred to as the type described) with which the present invention is concerned, namely one in which the mould is formed in a side wall with a vertical slot through which the filling spout projects and in which the mould is gradually lowered (the position of the spout remaining fixed) as the metal is poured in, the slot in the mould wall being progressively closed from the bottom upwards so that at any wall across the slot, whereby a symmetrical bore is built up and a symmetrical casting produced. Each sectional element should be of substantially the same thickness as that of the mould wall so that it will not differ appreciably in thermal capacity and conductivity from the rest of the mould.

According to a further feature of the invention the sectional slot-closing elements are mounted in a vertical series alongside the mould, each being pivotally movable about a vertical axis into and out of the closure position, and a stationary vertically disposed cam track is arranged to cooperate with cam-followers carried by or coupled to the sectional elements so that on descent of the mould the elements from the bottom of the series upwards will be progressively inserted into stage of the casting operation the slot is covered up to a height slightly above the position of the liquid metal surface at that stage.

In a known apparatus of the type described the closing of the slot in the mould wall is effected by means of covering plates forming part of an endless chain adapted to be engaged by the mould and traversed with it during its downward movement. In such apparatus the covering plates were longer than the width of the mould slot so that each bridged over the slot and a consequent disadvantage of such an arrangement is that the mould when built up is not symmetrical and does not permit of strictly symmetrical casting. A

further disadvantage of such apparatus is that the plates differ in thermal capacity and conductivity from the rest of the mould wall and lead to non-symmetry in'the freezing of the ingot. Moreover, the plates are liable to distortion, thus interfering with the necessary accuracy of fit in building up the portion of the mould surface concerned.

The principal object of the present invention is to remedy the above disabilities by providing the mould wall slot.

One construction of apparatus embodying the foregoing and other features of the invention will now be described by way of example, with reference to the accompanying drawings inwhichratus; I

Figure 2' is an end elevation of the apparatus looking on the mould slot-closing elements;

Figure 3 is a plan view in which the positions of a number ofthe closing elements are indi- Figured is a section at 4-4 of Figure 1, to a larger scale, showing the operation of the slotclosing elements, and

Figure 5 is a section at the line 5-5 of Figure l, to a larger scale, also illustrating the actuation of the slot elements.

Like reference numerals indicate like parts in the several figures.

In this example the mould Ill is supported by a vertical frame ll mounted on a wheeled truck II. The mould, which is of circular cross-section, is attached to a vertically movable carriage l3 comprising upper and lower pairs of guide 1 wheels ll movable in channel bars I5 forming an improved method of closing the vertical slot in the wall of themould.

According to the primary feature of the invention the mould wall slot is closed by means of sectional elements inserted into the slot progressively from the bottom upwards as the mould descends, each element being so shaped as to conform to the configuration of the adjacent portion of the mould wall so that the element when inserted forms a virtual continuation of the mould its starting point.

part of the vertical mould frame. Movement of the mould is effected by means of a hand-wheel l6 operating through bevel gears l1 and a vertical screw I! on which a nut I9 secured by brackets 20 to the mould carriage I3 is mounted. ,In Figure 1 the mould is shown at approximately mid-position during the process of casting having already'been lowered this distance from On the side of the mould remote from the operating screw' It, the mould is formed with a vertical slot 2! extendingfor substantially the whole of the length of the mould.

Figure 1 is a sectional elevation of the appa- Sectionalslot-closing elements 22 are arranged as a vertical series alongside the mould slotv 2|. Each sectional element 22 is carried on an arm 23 which is pivotally mounted on a vertical spindle 24 so that it may be swung horizontally towards and away from the mould slot. The vertical spindle 24 is supported by projections 25 on the mould so that on descent of the mould the spindle moves with it. Each sectional element 22 is of substantially the same thickness as the mould wall and is of arcuate shape so that when inserted in the mould slot it forms a virtual continuation of the adjacent portions of the mould wall, as clearly shown 'in Figure 4. The movement of successive sectional elements into the closure position is controlled, automatically on the descent of the mould, by a fixed vertical cam track. In this example the cam track is in the form or a portion of a vertical circular tube 25, the length of the are, as seen in horizontal section, varying from bottom to top. Along the inside of this curved member are fixed projections 21 which serve as a scroll, the form of which determines the movement of small rollers 28 attached to radialprojections from the inner (i. e. pivotal) ends of the arms 23 which carry the sectional elements. The molten metal is fed 'into the mould from a trough 30 through a filling the mould throughspout 3! which projects into the wall slot 2|. As the mould descends during casting the projections 29 are successively caused by the scroll cam to move in such a. manner as to rotate the arms 23 and thus swing the sectional elements into position at the right moment for closing the corresponding portions of the wall slot. A separate spring-operated roller fl carried by the main frame ensures that suc- 'cessive elements'are brought to the final closing position,

The apparatus described above fulfils the requirement that the height between the filling spout ii and the liquid-metal level in the mould is maintained at a small and nearly constant amount while the mould is lowered. It also enables comparatively rapid filling of the mould as well as quick cooling which are desirable where sound fine-grained ingots are to be produced.

I claim:

Ingot casting apparatus comprising a supporting frame, a carriage movable vertically on said frame, a mould on said carriage having a side wall provided with a vertical slot to permit projection therethrough of a filling spout, means for gradually lowering the carriage as the metal is poured in, the position of the spout remaining fixed, a plurality of sectional, segmented slotclosing elements of the same thickness as the mould wall mounted in a vertical series alongside the mould slot, each element being pivotally movon said frame for engaging said elements successively to urge them home as the mould descends.

WILLIAM SHELLEY WALKER.

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