US2488353A

US2488353A - Method and machine for forming metal

Info

Publication number: US2488353A
Application number: US548919A
Authority: US
Inventors: Chester E Unger
Original assignee: Wheelabrator Corp
Current assignee: Wheelabrator Corp
Priority date: 1944-08-10
Filing date: 1944-08-10
Publication date: 1949-11-15
Anticipated expiration: 1966-11-15

Description

Nov. 15 W49 c. E. UNGER METHOD AND MACHINE FOR FORMING METAL 2 Sheets-Sheet 1 Filed Aug. 10, 1944 INVENTOR.

CHESTER E. UNGER Nov. 15, 1949 c. E. UNGER METHOD AND MACHINE FOR FORMING METAL 2 Sheets-Sheet 2 Filed Aug. 10, 1344 F I G 5 INVENTOR.

CHESTER E.UNGER BY Mmm Patented Nov. 15, 1949 METHOD AND MACHINE FOR FORMING METAL Chester E. Unger, Mishawaka, Ind., assignor to American Wheelabrator & Equipment Corporation, a corporation of Delaware Application August 10, 1944, Serial No. 548,919

9 Claims.

This invention relates to a method and machine for forming metal, more particularly to a method and machine for making metal shot.

The invention provides a method and machine for producing metal shot, such as for example steel shot, in a continuous operation from a stream of molten metal.

According to the invention a stream of molten metal is directed onto a surface while the surface is being imparted a compound movement consisting of a rapid vibratory movement in a direction substantially normal to the surface element impacted by the stream of metal and a translatory movement substantially at right angles to the direction of the vibratory movement. The stream of metal directed onto the vibrating surface is broken up into individual particles and the particles are discharged from the surface in a predetermined direction. Subsequently the particles are cooled below their solidification point and collected.

The vibrating surface may be made of a refractory material to which the metal will not adhere. It may also be made of metal, means being provided for producing a protective film on the metal surface to prevent the molten metal from adhering. According to a feature of this invention a protective film is formed by a layer of rapidly moving air, the air film being created at the periphery of a rapidly spinning wheel.

The invention further provides machines for the continuous production of metal shot according to my method.

The various objects, features and advantages of this invention will appear more fully from the detailed description which follows accompanied by drawings illustrating my method and showing preferred forms of machines for carrying it out.

The invention also consists in certain new and original features of construction in combination of parts hereinafter set forth and claimed.

Although the novel features which are believed to be characteristic of this invention will be particularly pointed out in the claims appended hereto, the invention itself, its objects and advantages, and the manner in which it may be carried out may be better understood by referring to the following detailed description taken in connection with the accompanying drawings forming a part of it in which- Fig. 1 is a diagram illustrating the method of continuously producing metal shot;

Fig. 2 is a side elevation, partly in section, of a machine for the continuous production of cast metal shot;

Fig. 3 is a perspective view of a vibrating member which may be used in the machine shown in Fig. 2;

Fig. 4 is an elevational side view, partly in section, of a vibrating wheel for making metal shot; and

Fig. 5 is an end view of the machine shown in Fig. 4, a section being taken on line 5-5.

In the following description and in the claims various details will be identified by specific names for convenience. These names, however, are intended to be as generic in their application as the art will permit. Like reference characters refer to like parts in the several figures of the drawings.

In the drawings accompanying, and forming part of this description certain specific disclosure of the invention is made for the purpose of explanation, but it is understood that details may be modified in various respects without departure from the broad aspects of the invention.

The principle of the invention is diagrammatically illustrated in Fig. 1. A stream of molten metal I is directed from a pouring spout 2 onto a small surface element 3 which in actual practice forms a part of a larger surface. The surface element may be inclined by an angle appearing in the diagram between a vertical line 4 and an axis 5 normal to the surface element. A rapid vibratory motion substantially in the direction of axis 5 is imparted to the surface element as indicated by an arrow 6. A further and translatory movement is imparted to the surface element 3 in a direction substantially parallel to the surface element. This translatory movement may be combined with the vibratory movement and may either be of oscillatory or continuous character. The direction of the translatory movement is indicated by an arrow 1. The translatory movement may, as will later be shown, be produced by continuous rotation of the surface element in one direction or it may be produced as a component of a compound movement such as for example a substantially orbiculate motion of the surface element indicated by a series of arrows 8, 8' and 9, 9'. The arrows 8 and 8' represent the translatory component, and arrows 9 and 9' the normal component of the movement.

The stream of metal I is broken up at the surface element 3 into individual particles which are thrown off and cooled below their solidification point, for example by letting them drop into a bath of cooling liquid l0.

Referring now to Fig. 2 showing a machine for practicing the illustrated method, a base ll carries a crosshead l2 movable about a pivot l3. A

rod I4 is slidable in a bore l5 of the crosshead l2 and is mounted with its ends [6 and I1 in lugs l8 and IQ of a head 28.

The head forms a hollow chamber 2| accommodating a dispersing member 22 which protrudes through an aperture 23 at the top of the chamber;

Cooling liquid may be circulated in the chamber 21 and enters through a flexible tube 24 at a port 25 and is withdrawn through a flexible tube 26 leading from a port 21.

The dispersing member 22 may be made of a ceramic material capable, .of withstanding the high temperatures of molten metal and possessing sufficient strength to stand up under vibrafeed mechanism.

-rmember outwardly so as to maintain the distance 11 between the top surface of the dispersing member and. the pouring spout 2 substantially contions. Graphite has been found satisfactory as material for the dispersing member.

The dispersing member is mounted on .a stem 28 provided with a collar 29 supporting the lower end surface of the dispersing member. The stem extends througha threaded aperture 30 in a boss '3l at the "bottom of thechamber. Cooling liquid is. prevented from escaping past the stem 28 byxa packing 3.I" in a hollow portion 32 at the bottom of the head '28, the packing being compressed by a. threaded packing collar 33.

ThestemIZB is provided with a threaded end 34 screwed in a threaded sleeve 35 .in an outer member. 36 of an eccentric. The outer member 36. supports the. head 20 by rods 31 and 38.

.An' eccentric disk .39 is .mounted on a drive shaft 48 connected" to "a suitable source of .motive power (not shown).

A worm gear 41 is mounted on the drive shaft '40 and meshes with aworm wheel 42 on .an intermediary shaft 43'. The intermediar shaft .43 also carries a worm gear 44 meshing with a further worm wheel '45 on a vertical shaft 46.

"The vertical shaft "46 drives a feed shaft 41 through bevel gears 48 and Y49 on shafts 46. and 41, respectively.

The feed shaft 41 carries. an eccentric disk 50 engaging an outer member 5| to whicha connecting rod'52 is 'hingedly connected at 53. The connecting rod 52 carries a fork piyotally engaginga ratchetisupport 55 at 5.6. The ratchet support is rotatable mounted on a flange 51 of the sleeve 35.:and carriesa pawl 58, pivoted at 59. The pawl engages a ratchet wheel 6.8,- provided with..a key .6l. engaging a keyway 62 in the stem 28 so as to rotate the stem.

The operation of the-machine is as follows:

The drive shaft 48. is. driven at a rapid rate. The eccentric, 3.9., 36 imparts tothe-head 20 and the dispersing. member 22 a vibratory movement whose. chief component. is anoscil ation in. the direction. of the axis .of the stem 28. In addition the. head 20 and the. dispersing -member.22 per- .forman oscillating movementabout thepivot 13. The oscillatory movement .in theidirectionof the .axisof the stem. 28. causestherod M of the head to. slide back and .forthin the bore 1.5 of the crosshead. and the oscillatory. movement about the. pivot. l3..causes the headto tilt aboutthe pivot l3. Cooling ..liquidmay be circulated through the chamber .2Lof. the head 28- through conduitsldandlfi- A stream.of molten-:-metal is discharged from thespout Zontothetopsurface ofthe dispersing member 22. and-isrbroken .up into individual particles 63 which are thrown off by-the dispersing member in a predetermined direction "I -0' compensate for wear of the .top surface of the -r'dispersinga-member .22; the member is progressively rotated and also fed outwardly by the stant. 7

It has been found advantageous to incline i the: axis. of'thastem. 28 approximately fifteen degrees. with respect to the vertical in order to direct the discharge of the molten metal particles. This is a particular feature of the machine permitting a trough of coolingliquid to beso-placed with respect to; the' machine that all the'discharged metal particles dropinto it without spillage.

Steel shot of the commercial sizes of between Nos. 15 and 40 havebeen produced with this machine. The size of the'shotmay be controlled by adjusting the rate o'f-the drive shaft 40'. A rate of between-"3500 'and "4000B. '1. M. has been found to give excellent results. Uniform spherical shot predominantly of 'size'No; 20 has been produced by the machine operated at a'rate of 3800 R. P. M. of the drive shaft 48, steel of a temperature of 3000 Fahrenheit being discharged onto the dispersing -member at the rate of 50 pounds per minute. The stroke of the cam 39 in this instance was 'onequarter of one inch. I

A modified form of dispersing member is-shown in Fig. 3. The dispersing member 20' comprises a hollow steel plate '83 mounted on a non-rotatable stem 28. Cooling liquid is circulated through the hollow interior of the plate 63 through ducts '24 and 26. Anorifice 64 discharges a burning jet of acetylene gas which is directed onto the top surface of the hollow steel plate 63 and deposits a protective layer or film of carbon thereon to prevent the molten metal from adhering to thesteel surface.

The operation of the device shown in Fig. 3 corresponds in all details to the operation of. the machine shown in Fig. 2 with the exception that no continuous feeding of thedispersing member towards the pouring. spout 2. is required since the dispersing steel plate is..not subject to. appreciable wear.

A modified. form of machine. for. the continuous production of metal. shot is shown in Fig. 4. The machine comprises a bell shaped wheel..65 having a smooth peripheral dispersing .surface 65. The wheel is mounted on a. substantially horizontal drive shaft 61.resting in bearings 68 and 69. The bearings have base plates 10 and 1i to which are vulcanized. blocks 12 .and 13 of rubber or other resilient...material. The. resilient blocks 12 and -13,-in. turn, are vulcanized to mounting plates 14 and. 15. secured .to abase- 1.6 by bolts 1.1. 7

One end ofthe. drive shaft. 61. carries. adrive pulley E8 and the other end of the shaft engages the upper bearin .18 .of aconnecting. rod 80.-

The lower end-of the connecting. rodlifl forms the outer member .8 I. ofan: eccentric. An eccentric disk 82 runsin the. outermemberfil. and is fixedly mounted on a shaft 83 supporteddn bearings 84 and 85 secured to the underside of the base 16 by bolts 86. A drive pulley 81 is secured to one end of the drive shaft 83 for the eccentric.

A cooling fan 88 is mounted on the drive shaft for the wheel within the hollow bell-shaped space of the wheel. The fan acts in the manner of a centrifugal fan causing a fiow of air into the interior of the bell shaped wheel space along the drive shaft 61 and a discharge of air along the inner periphery of the wheel thus cooling the rim of the wheel. A wiper 89 may be mounted adjacent the periphery of the wheel.

The operation of the device is as follows:

The drive pulleys 18 and 8'! are preferably connected to different prime movers provided with means for controlling their speeds. The shaft 61 is driven at a rapid rate, preferably of the order of 3000 to 4000 R. P. M. The shaft 83 is driven causing a rapid. vibratory motion to be imparted to the wheel 65 through the eccentric 8|, B2 and the connecting rod 80. The rubber blocks 12 and 13 in the supports of the bearing 68 and 69 permit of sufiicient deflection of the axis of the shaft 61 from the horizontal to execute the vibratory movements forced upon the wheel 65 by the eccentric.

A stream I of molten metal is discharged onto the periphery 66 of the wheel from a spout 2 and is dispersed into individual particles '63 which are discharged in a predetermined direction to be cooled and solidified.

The rapid rotation of the wheel causes a film of air to be dragged alon the periphery of the Wheel. This film of air is found to act as a protective layer preventing the molten metal from adhering to the metal rim of the wheel.

Highly satisfactory results are obtained with a wheel having a diameter of 12 inches driven at a rate of 3600 R. P. M. and vibrated between 1000 and 3600 cycles per minute. Molten steel SAE 1030 discharged at the rate of 50 pounds per minute onto the wheel surface was formed into perfect solid round steel shot of the commercial sizes between and 40. Due to the effective cooling provided by the fan 88 no appreciable increase in heat of the periphery of the wheel was observed during the operation.

Obviously the present invention is not restricted to the use of the specific machines herein shown and described. Various changes and substitutions may be made, for example the protective film of air formed around the periphery of the wheel may be replaced by a film of other matter such as carbon as hereinbefore described. A film of water may be applied to the periphery of the wheel either by spraying water on the wheel or by immersin the lowermost portion of the wheel in a bath of water causing enough water to be dragged along by the wheel to form a protective surface on it. The air cooling of the wheel may be replaced by water cooling. Also various features may be added or omitted, equivalent devices and features may be substituted, dimensions and speeds may be correspondingly changed and various other changes be made. All such modifications will be apparent to a person skilled in the art and manifestly do not involve a departure from the spirit and teachings of this invention.

What is claimed is:

l. The method of making metal shot which comprises, directing a continuous flow of molten metal onto an imperforate surface; simultaneously imparting to said surface a definite and 6,, controlled vibratory motion in a direction substantially normal to the extent of the surface element impacted by said flow and a movement in a direction substantially parallel to said surface element, the vibration being sufiiciently rapid to disperse said flow of metal into individual particles by rebound from said surface; and cooling said particles below their solidification point.

2. The method of making metal shot which comprises, imparting to an imperforate surface a translatory movement substantially in the direction in which said surface extends and a controlled and definite vibratory motion in a direction substantially normal to said surface; directing a continuous flow of molten metal onto said surface, the vibratory motion of said surface being sufiiciently rapid to cause said flow of metal to be broken up into individual particles by rebound from said surface; and cooling said par-.- ticles below their solidification point.

3. The method of making metal shot which comprises, directing a flow of molten metal onto the periphery of a wheel spinning about a substantially horizontal axis, imparting to the wheel simultaneously a controlled and definite vibration in a direction at right angles to the spin axis and substantially normal to the surface area of the periphery impacted by the fiow of metal, the vibration being sufficiently rapid to cause the flow of metal to be broken up into individual particles by rebound from said periphery; and cooling said particles below their solidification point.

4. The method of making metal shot which comprises, directing a flow of molten metal onto the substantially smooth periphery of a Wheel having a substantially horizontal axis; simultaneously imparting to the wheel a controlled and definite vibration in a direction substantially normal to the surface area of the periphery impacted by the fiow simultaneously spinning said wheel about said axis, thereby causing a film of air to be dragged along by said periphery, the rate of spin being suificiently high to set up a film of air dense enough to prevent said flow of metal from penetrating said film and adhering to said periphery, the vibration being sufficiently rapid to cause said fiow to be broken up by rebound into individual particles; and cooling said particles below the solidification point.

5. The method of making metal shot which comprises, directing a continuous flow of molten metal onto an imperforate dispersing surface; simultaneously imparting a definite and controlled compound vibratory motion to said surface having a translatory component substantially in the direction of the surface impacted by said flow and a vibratory component substantially normal to said surface, the vibratory motion being sufiiciently rapid to cause said flow to be broken up into individual particles by rebound from said surface; and cooling said particles below the solidification point.

6. The method of making metal shot which comprises, directing a continuous flow of molten metal onto a solid dispersing surface; simultaneously imparting a controlled and definite compound vibratory motion to said surface having a translatory component substantially in the direction of the surface impacted by said flow and a vibratory component substantially normal to said surface, the vibratory motion being sufiiciently rapid to cause said flow to be broken up into individual particles by rebound from said '1' surface; maintaining:an insulatingi film: on said surface to-preventthe molten: metal from. adhering, to. said: surface; andv cooling said particles below; the solidification point.

7. A machine for the continuous production of metal shot .comprising, in combination, a wheel; means;- for-:spinning-said:whee1 about-a substantially horizontal axis; means for directing a stream zof molten metal. against the rim of said wheel; and means for vibrating said wheel in a substantially vertical direction.

8.; A machine; for the-continuous production of metal shot comprising, in combination, a wheel; means for spinning said wheel about a substantially: horizontal axis; means for directing; a stream .ofxmoltencmetal against the rim of said wheel;v andmeans :for' vibrating said wheel v in a direction substantially normal to the area of the rimiimpactedbythe stream of the molten metal.

9. A machine for the continuous production of metal shot comprising, a wheel; a substantially horizontal shaftsupporting said wheel; a bearing-resiliently supporting said shaft near one end;

8; a iree bearingon said-shaft near theother, end; and an eccentric engaging said free bearing to .impart a vibratory motion to said shaft; and means fordirecting a stream of molten metal against the rim of said wheel.

CHESTER E. UNGER.

REFERENCES. CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 19;33'7 Barnard Feb. 16, 1858 "148,229 Mayers Mar. 3, 18574 194,271 Shiver 'Aug. 14, 187%? 686,839 Bachmann NOV. 19,,1901 862,856 Tygard Aug. 6, 1907 952,828 Martyn Mar. 22,1910 2,018,478 Whittier Oct. 22, 1935 2,062,093 Kahn Nov. 24', 1936 2,269,528 Gallup Jan. 13, 1942 2,318,244 McClure May 4, 1943