US3077015A

US3077015A - Automatic ladles

Info

Publication number: US3077015A
Application number: US81540A
Authority: US
Inventors: Earle W Rearwin
Original assignee: Individual
Current assignee: Individual
Priority date: 1961-01-09
Filing date: 1961-01-09
Publication date: 1963-02-12
Anticipated expiration: 1980-02-12

Description

Feb. 12, 1963 E. w. REARWIN AUTOMATIC LADLES 3 Sheets-Sheet 1 Filed Jan. 9, 1961 uOmDOm zuxho 2O a @231 Iowa wmbmmumm r INVENTOR.

EARLE W. REARWIN ATTORNEYS Feb. 12, 1963 E. w. REARWIN 3,077,015

AUTOMATIC LADLES Filed Jan. 9, 1961 3 Sheets-Sheet 2 EAR LE W. REAEWIN ATTORNEYS Feb. 12, 1963 y E. w. REARWIN 3,077,015

AUTOMATIC LADLES Filed Jan. 9, 1961 s Sheets-Sheet s INVENTOR. EARLE W. REARWIN ATTORNEYS United States Patent Ofilice Patented Feb. 12, lot-53 3,77,di5 AUTQMA'EEC LADLEd Earle W. iiearwin, Longmeadow, Mass assi nor to Joseph A. Kozzna and .losegsh A. Korma, In, both of Dearborn, Mich.

Filed Jan. 9, 1961, See. No. 815% 6 Qialms. (Cl. 22-$l) My invention relates to a new automatic ladle for dipping molten metal from the dip Well of a melting furnace and pouring into the receiving chamber of a metal casting or extruding machine, and more particularly to an improved ladle construction and automatic controls for opening same.

Heret fore, in the feedin of molten metal to casing or extruding machines, many problems have been encountered. Delays in the closing or locking of the dies held for feeding, resulting in failure to completely fill the dies or molds, or, if the metal is not poured, it will harden in the ladle. Also, delays and the inefficient methods by which the molten metal is dipped result in the tin: of excessive oxides, causing poor quality of Moreover, experience shows that molten metal is sometimes inadvertently poured into the receiving chamber of the machine when tr e dies or molds are not fully closed and/ or locked, and the charge of metal may cool and harden in the receiving chamber causing expensive and loss of the use of the machine until repairs An object of the present invention is to improve metal casting quality by providing an automatic ladle which will dip molten metal only from beneath the oxidized surface of the melting and/ or loading furnace.

Another obiect of the invention is to avoid losses due to cooling of the molten metal by providing an automatic ladle with a heating means.

A further object of the invention is to improve opera tion of automatic ladies by providing an actuating system connected with the casting or extruding machine which will provide for rapid transfer of metal from the dip well of the melt ng furnace to the machine.

A still furthe object of the invention is to protect casting and extrud I machines by providing a means for preventing pouring of metal unless the dies or molds are closed and locked.

Yet a furl er object of the invention is to facilitate effee've operation of casting and extruding machines by providing a fully automatic ladle mechanism integrated with the operation of the machine.

For a more complete understanding of the invention, reference may be made to the accompanying drawings illustrating a preferred embodiment of the invention in which like reference characters refer to like parts throughout the several views and in which l is a side View, psrtia ly in section and partially in elevation, of a preferred ladle mechanism embodying the present invention.

FIG. 2 is a top plan view of part of the mechanism shown HG. 1.

F16. 3 is a cross-sectional view of the ladle taken on the line 3-43 of PEG. 1.

d8. 4 is electrical diagram illustrating a preferred or typical control system for the present invention.

R6. 5 is a diagrammatic view of a preferred actua ing system embodied in the present invention.

PEG. 6 is a side view, partially in section and partially n elevation, of a modified construction.

A ladle mechanism ill is illustrated in FIGS, 1 and 2 as preferably mounted on the dip-well ll of a melting and/or holding furnace 1. and oper ble to dip molten metal therefrom and pour into tl e receiving chamber 13 of a casting machine 14, a portion only of which is shown. Although a die casting machine is shown, it will be apparent that the invention will operate with other types of machines such as permanent mold, gravity fed machines and the like.

One preferred ladle mechanism comprises an elongated liquid conducting structure such as a trough, launder or conduit having downwardly extending flanges to to which is secured a rod 17 pivotally carried on upwardly extending arms of a support 19, preferably mounted on the dip well structure ii. A ladle ill is carried on one end of the structure and a pouring spout or the like is carried on the other end. The structure 15 is arranged to alternately dip molten metal 22 from the dip well it and pour it into the receiving chamber 13 of the casting machine id.

The ladle is provided with a cover 2-5 having a downwardly extending cup shaped portion 25a conforming generally to the contour of the ladle 29 but spaced therefrom to provide a passage 26 from the edge of the portion to a slot 27, shown in FiG. 3, cut into the end of the ladle 29 at a location remote from the edge of the portion 25a.

in operation, when the ladle is dipped into the molten metal 22 (called the fill position), the portion pushes aside the oxides which are always present on toe surface. The cover prevents these oxides from entering the ladle 2b, and instead, pure molten metal flows from beneath the surface through the passage 2w into the slot 27. The of the slot 2.7 regulates the amount of metal retained in the ladle 2 when same is raise in case the charge is not poured immediately, and also for the purpose of avoiding any cooling of the charge in flowing through the structure 15 when the pouring spout is lowered, a radiant heater device 3% of any preferred type (shown only in FIG. 1), is mounted on structure E5, to furnish radiant infra-red heating to the interior thereof.

The rod 37 has on its outer end a leverarm 31 preferably actuated by a piston 32 reciprocable in a fluid cylinder 33 pivotally mounted as at 34 on a floor bracket 35. The ladle mechanism 1% is illustrated in full line in an intermediate position and in phantom lines in the fill and pour positions.

At each position, some part of the mechanism such as the lever arm will be arranged to contact and trip a limit switch, these switches designated as LS4, LS2 and 18-3.

A portion only of a typical die-casting machine 14, with which the ladle mechanism may be used, is illustrated as comprising a stationary die plate 4d carrying a stationary die half :1, a movable die half 42. having a cavity i3 in which is mounted a die 4 A tubular sleeve is carried by the die plate and provides for the shot or receiving chamber 13, the molten metal being poured therein through a pouring slot 46 and subsequently forced into the die cavity 43 by a piston 47, all as is conventional with such machines.

When the movable die half 42 is closed against the stationary die half 4-1, a locking mechanism 29 can be actuated in conventional fashion to lock-up the macihne, and when so locxed, a relay designated as DL in FIG. 1 is preferably arranged to be closed for a purpose to be explained.

The general preferred operation of the ladle mechanism is as follows:

When the machine operator presses a switch (not shown) to initiate closing, the ladle mechanism It} will be simultaneously actuated to lower the ladle 20 to the fill position in the dip well 11 and when filled, will automatically raise to the intermediate position. If the lockup switch BL is closed, the control system of the ladle mechanism 10 will operate to continue raising the ladle 2t) and will lower the spout 21 to the pouring slot 46, the controlled charge of molten metal flowing from the ladle at) through the pre-heated liquid conducting structure 15 and from the spout 21 into the receiving chamber 13. The ladle mechanism 10 will dwell at this pour position until pouring is completed and will then return to the intermediate position. After piston 47, in the case of a die-casting machine, is actuated to make the shot and the die 42 opened, a new cycle can be initiated.

In FIGS. 4 and 5, a preferred or typical control system is illustrated diagrammatically in more detail, noting that switch, relay and valve positions are shown as when the ladle mechanism 10 is in the intermediate position with the limit switch LS-2 engaged by the arm 31, and that limit switch LS-2 is a gang switch with its three switches designated as LS-Za, LS-Zb, and LS-Zc, in FIG. 4. Op eration of the preferred circuit diagrammed is as follows:

(1) Master switch MS is closed manually.

(2) If used, pump switch PS is closed manually, energizing solenoid PR to close relay PR holding the PR circuit and close relay PR to start the pump P. This provides fluid pressure for the cylinder 33. In some installations, the user may instead use pressure from the casting machine or other source, and instead of the shown fluid operated system, an electrical or mechanical system may be employed.

(3) The casting cycle is initiated by the operator, to start the dies or molds closing and to simultaneously close relay DS, energizing solenoid 1CR through circuit having relays ZTR and 2CR Energizing solenoid lCR closes relay lCR to energize valve solenoid VL and actuate a valve 50 shown in FIG. 5, the valve shuttle 51 being moved to direct fluid pressure through a conduit 52 to the upper end of the cylinder 33. This retracts the piston 32 to lower the ladle 20 into the molten metal 22 (fill position).

(4) The ladle mechanism in the fill position engages and closes limit switch LS-3 (NO) to energize solenoid ZCR (ITR and 2TR being closed). Energizing solenoid ZCR closes relay 2CR to hold the ZCR circuit, opens relay 2CR to de-energize solenoid 10R (thereby opening relay ICE and de-energizing the valve solenoid VL), and closing relay ZCR to energize solenoid 3CR, limit switch LS2c (N.C.) having closed on movement of the ladle mechanism 10 from the intermediate position.

(5) Energizing solenoid 3CR closes relay 3CR to energize valve solenoid VR and actuate the valve 50 to direct fluid pressure through a conduit 53 to the lower end of the cylinder 33. This extends the piston 32 to raise the ladle 20.

(6) When the ladle mechanism reaches the intermediate position, limit switch LS-2c (N.C.) opens. However, if the dies or molds are locked, the lock-up relay DL will be closed, so that, relay ZCR also being closed (see step 4 above), solenoid 3CR will remain energized to keep relay 3CR closed so that the ladle mechanism will continue on to the pour position (see step 9 below).

(7) If the casting machine is not locked up when the ladle mechanism 10 reaches the intermediate position (in step 6 above), solenoid SCR tie-energizes, opening relay 3CR to de-energize valve solenoid VR so that the ladle mechanism will remain in this intermediate position, holding limit switch LS-2b (N.O.) closed to energize a timer solenoid HR.

(8) On energizing timer solenoid 1TR, timer relay 1TR will time out and open (unless the die or mold gets locked in the interim) to de-energize solenoid ZCR, closing relay 2CR to re-energize solenoid lCR, initiating the ladle lowering cycle again (from step 3 et seq.)- This sequence of operation avoids the possible inadvertent pouring of metal into a casting machine not yet ready to operate and returns the ladle 2a to the dip well to prevent freezing of the metal in the ladle or the accumulation of excessive oxides.

(9) When the ladle mechanism 1t? is actuated to the pour position, limit switch LS-l (N.O.) closes to energize a timer solenoid ZTR, which closes relay ZTR to hold the ZTR circuit, opens relay ZTR and on timing out, relay 2TR opens (see step 11 below) and relay 2TR (if used) closes.

(10) Closing relay 2TR may be utilized either to signal the operator that the shot may be made or to automatically operate the die-casting piston 4'7, where the machine is a die-casting machine.

(11) Opening relay 2TR de-energizes the solenoid ZCR to close relay 2CR (see step 12 below) and to open relay 2CR, de-energizing the solenoid SCR to open relay SCR and de-energize valve solenoid VR.

(12) Closing relay 2CR again energizes solenoid lCR (limit switch LS2a being closed in the pour position) closing relay 1CR to energize valve solenoid VL and lower the ladle mechanism It) to the intermediate position, where the limit switch LS-2a is again engaged and opened to de-energize solenoid 1CR once more stopping ladle operation at the intermediate position.

(13) Before a new cycle can begin (since relay ZTR is open), the dies or molds must be opened to open relay DW, de-energizing solenoid ZTR to close relay ZTR after which, when the operator starts the dies closed, the relay DW will close and the sequence of operation will repeat from step 3 et seq.

In FIGS. 6-8, another modification is illustrated in which a ladle mechanism 116) comprises a shortened pivotally carried liquid conducting structure having a ladle 120 at one end, and a second liquid conducting structure 115A having a pouring spout 121.

A bracket 119 pivotally carries the structure 115 as at 117, and the second structure 115A is preferably pivotally carried by the bracket 119 on trunnions 123 or the like so that it may be placed and remain stationary with the spout 121 disposed in the receiving chamber of the molding machine (not shown in FIGS. 6-8). The structure 115 only is operatively connected with the cylinder 33 in this modification, so that when raised to the pour position, the molten metal flows into the stationary structure 115A and thence to the molding machine.

For convenience, switches and the heating device have been omitted from FIGS. 6-8, although operation will be substantially the same. It will be apparent that the switches LS-1, 2 and 3 shown in FIG. 1 may be located for actuation by any of the operative structure involved.

The advantage in thus dividing the conducting structure into two sections lessens the cost and increases convenience where the ladle must be replaced or changed, since only a small part of the total structure is involved.

Although I have described only one preferred embodiment of the present invention, it will be apparent to one skilled in the art to which the invention pertains that various changes and modifications may be made therein without departing from the spirit of the invention or the scope of the appended claims.

I claim:

1. An automatic ladle mechanism for transferring controlled charges of molten metal from the dip Well of a furnace to the receiving chamber of a casting machine having molds selectively opened and closed and locked, said ladle mechanism comprising a support, a liquid conducting structure pivotally carried on said support to swing in a vertical plane, a ladle on one end of said structure, said ladle mechanism being provided with means selectively operable to alternately lower said ladle into and raise same from the molten metal contained in said dip well, the molten metal dipped from said dip well flowing through said conducting structure to the casting machine and said ladle having means excluding oxides on the surface of the molten metal from entering said ladle when same is lowered into said dip well, said excluding means comprising a cover extending over and closing the top of said ladle and projecting outwardly and turned downwardly around the sides thereof to form a space between the ladle and the downwardly turned portion of the cover, and means openly connecting said space with the ladle under the cover.

2. The mechanism as defined in claim 1 and in which said latter means comprises a slot in the edge of said ladle remote from the edge of the downwardly turned portion of said cover.

3. An automatic ladle mechanism for transferring controlled charges of molten metal from the dip well of a furnace to the receiving chamber of a casting machine having molds selectively opened and closed and locked, said ladle mechanism comprising,

(a) a support,

(b) a liquid conducting structure carried on said support to swing in a vertical plane,

(0) a ladle on one end of said structure,

(d) actuating means operable to selectively pivot said structure to a fill position in which said ladle is lowered into the molten metal contained in said dip well, to an intermediate position in which said ladle is removed from the molten metal, and to a pour position in which said ladle is raised higher than the conducting structure so that the molten metal will flow from the ladle through the conducting structure to discharge into said casting machine and (e) automatic means normally operating said ladle actuating means through a cycle in sequence beginning with the intermediate position to the fill position, then through the intermediate position to the pour position, then returning to the intermediate position,

(7) said automatic means including means connected with said casting machine and automatically operating said ladle actuating means from the intermediate position to the pouring position only when the casting machine molds are in a locked position, and

(g) means holding said actuating means at said intermediate position if said molds are not in a locked position.

4. The mechanism as defined in claim 3 and in which said holding means is automatically operable to retain said ladle actuating means in the intermediate position for a predetermined time interval if said molds are not in a locked position and to return said ladle mechanism back to the fill position if said molds are not locked within said predetermined time interval.

5. The mechanism as defined in claim 4 and in Which said automatic means includes means automatically operable to hold said ladle actuating means in the pour position for a predetermined time interval.

6. The mechanism as defined in claim 4 and in which said automatic means includes means connected with said casting machine and automatically operable each time the casting machine molds are closed to initiate the aforesaid sequence of actuation of said ladle actuating means.

References fitted in the file of this patent UNITED STATES PATENTS 1,313,895 Hopkins Aug. 26, 1919 2,263,880 Jung NOV. 25, 1941 2,363,759 Waldie NOV. 28, 1944 2,568,578 Bennett Sept. 18, 1951 2,676,370 Doehler et al Apr. 27, 1954 2,962,278 Goetz Nov. 29, 1960 2,982,534 Mefiert May 2, 196].