US 3393837 A
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y 1968 TAKAHIKO TAKESHIMA 3,393,837
DEVICE FOR LADLING MOLTEN BATH OF METALS Filed July 19, 1966 2 Sheets-Sheet l INVENTOR. TAKAHIKO TAKESHIMA ATTORNEY.
July 23, 1968 TAKAHIKO TAKESHIMA ,3
DEVICE FOR LADLING MOLTEN BATH OF METALS 2 Sheets-Sheet 2 Filed July 19, 1966 INVENTOR. TAKAHIKO TAKESHIMA wad ATTORNEY.
United States Patent Oflice 3,393,837 Patented July 23, 1968 ABSTRACT OF THE DISCLOSURE A device for ladling a molten bath of metals which consists of a drive means connected to a power source and disposed on one end of an arm, a fixed circular body on a rotary frame, a circular rotary means fixed with a ladle and being provided on the other end of the arm, endless chain means mounted between the fixed circular body and circular rotary means whereby the ladle is moved with its surface maintained in a horizontal position by an ellipsoidal movement of the chain means by virtue of the fixed circular body and circular rotary means for the ladling of the molten bath of metals, and means for inclining the ladle mounted on a piston rod of an hydraulic cylinder fixed rotatably through a shaft upon a support base.
The present invention relates to a device for ladling a molten bath of metal and in particular refers to a device for feeding molten metals automatically from a pan within a furnace into a casting sleeve of a die casting machine.
Generally, the feeding of molten bath of metals to a die casting machine of the cold chamber system has been made manually for the die casting of aluminum and like materials. Such automatic feeding machines as have been reduced to practical use were mostly of the air pressure type. In other words, they were of such a type that the pan of the furnace was closed airtight, and molten metals were forced to be squeezed out under the air pressure acting upon the surface of the molten metals. However, they were costly and highly corrosive. Besides, a constant amount of feed bath could not be maintained. Recently, mechanical systems of direct ladling have been developed, but they are not adequate to meet the requirements of the automatic means for feeding the metal bath.
It is noted that in any automatically operating device for feeding molten metals from a pan into a casting sleeve of a die casting machine, a mechanical or air pressure type, should at least fulfill the following conditions:
(a) A constant amount of metal bath can be provided at all times and any adjustment in the amount of bath to be fed may be made with case;
(b) The oxidation of the metal bath, the dripping of the metal bath from parts of a feeding device and the adhesion of the molten bath onto parts of the device in the course of feeding the molten bath of metals can be fully avoided;
(c) Pure molten bath of metals not containing solidified metals or other impurities are to be fed;
(d) Supply of molten bath to the pan for molten metals is quite easy;
(e) Simple construction and easy maintenance;
(f) Low manufacturing and installation costs.
The object of this invention is to provide a device for ladling a molten bath of metals which may fulfill the above-mentioned conditions.
According to the present invention, there is provided a device for ladling a molten bath of metals comprising a rotary drive means connected to a power source and being provided on one end of an arm, a fixed circular body on a rotary frame, a circular rotary means fixed with a ladle and being provided on the other end of said arm, chains and like means mounted endlessly between said fixed circular body and said circular rotary means, whereby said ladle is moved with its surface maintained in horizontal position by an ellipsoidal movement of chains and the like by means of said fixed circular body and said circular rotary plate so as to ladle the molten bath of metals.
'Furthermore, according to a preferable embodiment of the present invention, a worm and a worm-wheel may be used as said rotary drive means, and chain-wheels with the same pitch-circle respectively may be used as said fixed circular body and circular rotary means. Further, it is preferable to provide said rotary drive means and the fixed circular body concentrically.
The device according to the present invention may be also provided with a means for inclining the ladle which is mounted on a piston-rod of a oil pressure cylinder which is mounted rotatably on a support base by means of the shaft.
In the above embodiment of the invention, the end of the rotary frame may be connected to any other driving mechanism.
Still more, by the present invention, it has become possible to change the angle of inclination of the ladle against the surface of molten metals when molten bath of metals are ladled.
The device according to the present invention is preferably used in combination with a hopper which is pivotably mounted to locate directly overhead of a casting sleeve of a die casting machine and the shaking movement of the hopper is coupled with the transfer movement of the ladle.
In the above embodiment of the present invention, the shaking movement of the hopper may be provided by means of a pressure cylinder.
With the above-described mechanism and operation, the device of the present invention can achieve such effects as follows:
1) An amount of molten bath to be fed is determined by an angle of inclination of the ladle so that a precise amount of bath can be fed. By changing the angle of inclination of the ladle, therefore, it is quite possible to adjust the amount of bath and thereby to obtain any predesignated amount of bath with much ease.
(2) The ladle is carried to the surface of the molten bath in the state of inclination as determined previously and is returned to a perpendicular position when the ladle comes immediately above the surface of the molten bath. Accordingly, there is extremely little chance of spilling the molten bath from the ladle on the way of feeding the bath. Since no conduit is employed, as seen in common feeding machines of the air pressure type, there will be practically no oxidation of the molten bath, dripping of bath from parts of the feeding means, and adhesion of bath onto the parts of the feeding means will take place during the operation.
(3) Since the hopper is transferred only after a complete feeding of bath has been made in the casting sleeve, there is no mixing of impurities produced at the bottom of the ladle and solidified metals on the surroundings of the ladle in the casting sleeve so that excellent products can be obtained.
(4) The heat insulating furnace or the melting furnace can be of the open-air type with its upper part completely uncovered so that the molten bath or ingots can be supplied very simply.
(5) The device has a very simple construction and the ladle is the only part which is required to submerge in the molten bath. Consequently maintenance of the device is very simple. In short, the ladle can easily be replaced with a reserve ladle or by any other adequate ladle in case it becomes necessary to take out a larger amount of molten bath.
(6) Because of its simple construction, the ladling device according to the present invention may be installed in any common furnace without any troubles. Yet its manufacturing and installation costs are held very low.
The above and other features of the invention and the advantages deriving therefrom will be evident from the following specification of a preferred embodiment shown by way of non-limiting example with the accompanying drawings, in which:
FIGURE 1 is a vertical cross sectional view of one embodiment of the device according to this invention.
FIGURE 2 shows a cross section of the device on the line llII on FIGURE 1.
FIGURE 3 shows a cross section of the device on the line IIIIII on FIGURE 1.
FIGURE 4 shows a cross section of the device showing operative condition of a ladle according to this invention.
Referring to the drawings, a pan 1 is provided in a heat insulating furnace or a melting furnace 2 and in the pan is contained molten bath of metals 3. When the level of the molten bath decreases, additional molten metal is supplied in a state of bath for a heat insulating furnace while ingot is supplied for a melting furnace.
A ladle 4 is fixed by means of bolts 5 to a ladle fixing plate 6 and has a construction adapted to be easily replaced.
The ladle fixing plate 6 is fixed to a chain wheel 7 to which is fitted also a shaft 8 in a rotatable manner. On one end of an arm 9 is fitted the shaft 8 and on the other end thereof is fitted a drive shaft 10.
There is provided a chain wheel 11 fitted on a rotary frame 12 in such a manner that said chain wheel 11 is disposed concentrically with the drive shaft 10. The chain wheel 7 and the chain wheel 11 are connected by means of chains 13 and 14. Between the chains 13 and 14 there are provided two pieces of turn buckles 15 whereby tension of the chains 13 and 14 can be adjusted desirably. Further, diameters of pitch circles of the two chain wheels 7 and 11 are made equal.
A worm wheel 16 is provided on the drive shaft 10, said worm wheel being meshed with a worm 17 driven by a hydraulic motor 18 provided on the rotary frame 12.
On the side walls of the melting furnace or the heat insulating furnace 2 is provided a bracket 19 fitted thereon and on said bracket :1 support base 20 is fixed by means of bolts 21. On the upper end of the support base 20 there is provided a shaft 22 through bearings 23 and said rotary frame 12 is rotatably mounted on the shaft 22.
Furthermore a hydraulic cylinder 24 is fitted by means of a pin 25 to a bracket 26 on the support base 20 so that said hydraulic cylinder can oscillate freely. One end of a piston rod 27 of the hydraulic cylinder 24 is fitted at a projection 12A of the rotary frame with a pin 28.
It is further designed that when the ladle 4 is situated at a position shown by chain line in FIGURES 1 and 2 said ladle comes to a position so that outlet of the ladle 4 for the molten bath can situate on the line of extension of axis of the shaft 22.
There is provided a hopper 29 directly above a casting sleeve 30 of the die casting machine and for this purpose said hopper is fixed at a hopper seat 31 by means of a pin 32 to be capable of oscillating, and said hopper seat 31 is attached to a fixed platen 33 of the die casting machine by bolts 34. Furthermore, a bracket 35 is fitted on said fixed platen 33 by means of bolts 36, and on this bracket 35 a air cylinder 37 is oscillatorily fitted by a pin 38. The projection 29A of the hopper 29 is provided at a piston rod 39 of the air cylinder with a pin 40 so as to freely oscillate.
41 is a plunger tip for casting the molten metal 3 in the casting sleeve 30 into a metallic mold (not shown). 42 is a plunger rod.
In the drawings, (A) denotes a position of the ladle 4 when lying in the melting furnace or the heat insulating furnace 2; (B) shows a position when the ladle 4 comes directly above the hopper 29; and (C) in FIGURES 2 and 3 denotes a position of the ladle 4 when the ladle is tilted from the position of (B) by throwing down rotary frame 12 from the position of (B) and to discharge the molten bath into the hopper 29. (D) in FIGURES 2 and 3 shows a position taken at random by the rotary frame 12 when the latter has turned upright after feeding of bath has been accomplished.
In the embodiment of this invention, the worm 17 and worm wheel 16 can be substituted with other common rotary drive means; the chain wheel 11 with a fixed circular body; and the chain wheel 7 with a circular" rotary means. In said cases the chains 13 and 14 can be substituted by wire rope and the like.
Operation of the ladling device according to this invention will now be described in detail.
In the first place, it is to be understood that the ladle 4 as shown by (A) in solid line in FIGURE 1 lies below the surface of the metal bath 3. However, the rotary frame 12, as shown in FIGURES 2 and 3, is located at a position of (D) which makes an angle of 0 with the position of (B) so that the ladle 4 is tilted through the angle 0 and dipped in the metal bath 3, i.e., the ladle will lie in the metal bath 3 in the state shown by (a) in FIGURE 4.
When the hydraulic motor 18 is revolved by power from a power source not shown, the worm 17 in direct association with the hydraulic motor 18 revolves. In meshing with the worm 17 also revolves the worm wheel 13 in the clockwise direction as shown in FIGURE 1. The arm 9 therefore revolves in the clockwise direction with the drive shaft 10. Simultaneously chains 13 and 14 in association with the chain wheel 11 lying in the concentric circle with the drive shaft 10 revolves the chain wheel 7 associated with the ladle 4 through the fixing late 6 in the reverse direction of the rotation of the arm 9 through the angle that the arm 9 has been displaced.
Accordingly the ladle 4 moves maintaining the same posture irrespective of the position of the arm 9 wherever it is situated.
When the arm 9 starts to rotate, the ladle 4 rises up from the surface of the molten bath while maintaining its inclination at an angle of 0. When the ladle 4 is situated above the surface of the molten bath 3 as shown in FIG- URE 4(b), the surface level of the bath lies at a position of (M) which is the lowest point on the edge of the ladle 4. In this state, the amount of bath to be fed is measured. Therefore by varying the inclination angle of the ladle 4 or the angle 0 it is possible to adjust the amount of bath to be fed desirably.
After the measurement has been made, the pressure oil enters the upper part of the hydraulic cylinder 24 by means of electric signals and the piston rod 27 is pushed down so that the rotary frame 12 turns in counterclockwise direction around the shaft 22 and stops at a perpendicular position. The ladle 4 too restores a vertical posture from an inclined one, and the surface of the molten bath in the ladle 4 comes to the extent of (H) as shown in FIGURE 4 ,(C), thus preventing the spilling of the molten bath which may otherwise result from the oscillation of the ladle in operation.
In the course of operation, the rotation of the arm 9 is carried out in continuity. The ladle 4 moves up to the position of (B) as shown by chain lines in FIGURE 1, in other words, it comes to the position just above the hopper 29, and stops there. Up to that time, the hopper 29 remains in the position of (E) in FIGURE 1, and when the ladle 4 comes to the position of (B), simultaneously the pressure air is delivered to the side of the piston rod 39 of the air cylinder 37. The piston rod 39 is pulled to the right side. The hopper 29 turns around the pin 32 and stops at a position of (F) as shown by chain lines. As soon as the hopper 29 comes to the position of (F) the pressure oil enters the lower part of the hydraulic cylinder 24. Consequently the piston rod 27 is pushed up and the rotary frame 12 rotates in the clockwise direction around the shaft 22 as shown in FIGURES 2 and 3 and comes to the position of (C). The molten bath in the ladle 4, therefore, flows into the hopper 29 and then into the casting sleeve 30. Thereafter the plunger tip 41 and the plunger rod 42 are advanced to the left side and the molten bath is cast finally into the mold (not shown).
When flowing of the molten bath into the casting sleeve 30 is finished, the ladle 4 returns to the former position. Thereupon the hopper 29 comes back from the position of (F) to that of (E) thereby to prevent from falling into the casting sleeve 30 the solidified metals and impurities which have been adhered onto the outside of the ladle 4 during the process of casting.
When the ladle 4 arrives at the position of (D) the hydraulic motor 18 turns in the reverse direction. The arm 9 then rotates counter-clockwise and stops in the original positions. Thus one cycle of operation is accomplished.
1. A device for ladling a molten bath of metals comprising: a support base, a frame pivotally mounted on said base about a first axis, an arm pivotally mounted on said frame about a second axis perpendicular to said first axis, a drive means connected to a power source and disposed on one end of said arm, a circular body fixed on said frame concentric with said second axis, a circular rotary means fixed with a ladle and being pivotally mounted on the other end of the arm, endless chain means mounted between the fixed circular body and the circular rotary means, said drive means being connected to pivot said arm whereby the ladle is moved with its surface maintained in a horizontal position by an ellipsoidal movement of the chain means by means of the fixed circular b body and the circular rotary means for the ladling of the molten bath of metals, in combination with means for inclining the ladle including a hydraulic cylinder and piston rod pivotally mounted on said support base and pivotally connected to said frame.
References Cited UNITED STATES PATENTS 1,766,574 6/1930 Westin et al. 2 l4--1 2,463,811 3/ 1949 Schulze 222166- 3,003,206 10/1961 Peras 222-166 FOREIGN PATENTS 1,191,645 4/ 1959 France.
SAMUEL F. COLEMAN, Primary Examiner.