US2540523A - Lubricating mechanism for strip casting machines - Google Patents

Description

Feb. 6, 1951 H. l.. HORN 2,540,523

LUBRICATING MECHANISM FOR STRIP CASTING MACHINES Filed June 5, 1948 HARRY L.. HORN l/ A 1N V EN TOR.

ATTO/ENQ atented 6, 159541 Nmirri) STATES nUBRIoATING MEoHANrsM Fon nsrnljr CASTING MACHINES Harry Horn, Dallas, Ten Application June 5, 194s, 'seramo- 315285 1 n This invention relates to new and useful im. provements in lubricating mechanisms for use instrip casting machines for making printers leads, slugs and rules.

The machines used for diefexpressing or draws ing strips of type metal 'are adapted to form a continuous metal bar by drawing the same from abody of molten metal, the metal being drawn through the shaped channel of a suitable mold or die and cooled .while passing through said channel, so that the metal enters one end of the channel as a fluid andemerges from theother end thereof as a solid strip bar. The movement of the strip or vbar through the channel is effected by pulling ulpon the solidified portion thereof pro,- truding from the die, the molten metal being subjected merely to suflicient pressure to `cause it to follow through the die channel rather than to apressure great enough .to directly expel or extrude the metal through such channel.

f The lubricating device of the invention is designated particularly for introducing a lubri.-

cant into the channel of the .die for facilitating the :drawing of the formed metal through the die and preventing frictional adherence of the formed strip to the walls of .the die channel, so thatthe strip is formed with smooth surfaces and of a uniform size.

Qne object of the invention is to provide an improved lubricating mechanism for inserting lubricant into the ,strip forming channel yof the dieci a machine for making gprinters leads, Slugsand rules, and thelike.

An important object of the invention is to provide a lubricating mechanism Ahaving valve means for controlling `the admission of lubricant to the channel of the die of the strip forming machine, said valvemeans being normally closed and opened at predetermined intervals to admit lubricant to Ythe channel 4as aforesaid.

Another .Object of the invention is to provide a lubricating mechanism of the characterde,4 scribed having means for preventing backflow of lubricant or molten `metal into the body of the lubricator mechanism.

.1' A 'particular object nf `the inventionis .to provide a lubricating apparatus having a reservoir and valve means normally closed and intermittcntlv opened for controlling Ow cf lubricant f said reservoir, the outlet from ythe 'resers voir past the valve means comrnunicating Awith omal Secondary lubricant chamber having an outlet into the molten metal passage ofthe str-ip casting machine, whereby lubricant, from the'v reservoir is .admitted at predetermined intervals aolaims, (o1. .2a-57.2)

into the-'secondary chamber and is withdrawnfrom said chamber Ainto the molten metal pas-- sage 'of tlliestrip 'casting machine, the secondary' chamber being provided with a backilow ehecl valve at its outlet end for preventing molten metal'from, entering said chamber.

Another objectief 'the invention is to provide a-flubricating mechanismof thecharacter dei scribed having. an -improvedactuating ineoha-` nismY for 'opening thev control valve between the lubricant ,reservoir `'and theY secondary lubricant' chamber-whereby the Vvalve is opened Yat prede-' termined intervals and vis positively resiliently maintained closed at-all other times to prevent: undesired flow of oil from the-reservoir, .and also to prevent admission of molten metal to such reservoir. v ,1 IA still further object of the invention is to )provide :means for adjustably controlling the Imovement ,of `the vvalve separating the lubricant reservoirfrom the secondary lubricant chamberv tocontrol the amountof lubricant `permitted to pass through thevalve YWhen the valve is opened.

Another object of `theinvention is to provide an lubricating system'of the character described which lis readily removable and replaceable, if desired or necessary.

Additional objects and advantages of the invention .will readily be apparent from the read-- ing of the following description of a device constructed accordance with the invention, and reference to the accompanying drawingsthereof, Wherein: l

Figure 1 is a view, .partly in elevation and' partly in section, of a portion of a machine formaking .pri-liters leads, slugs, rules, and thezlike, and showing a .lubricating mechanism con;- structed in accordance with the invention inf" corporated therein,

Figure 2 .isr an enlarged vertical cross-sectional view of the lubricating mechanism, showing the' lubricant admitting val-ve opened to permit pas# sageof oil, and f Figure 3 is a similar view of the valve mecha-* nism, takenatright angles to Figure 2, showingl the lubricant controlling valve closed.

-Iii-Itho drawings, the numeral lll designates a melting pot or crucible, substantially cylindrical inform, which is mounted on a bench or table top .Il of a strin casting machine used for forming continuous barsof metal from a molten body.

thereof, inthe form of prin-ters? leads, slugs, rules, and the like. Beneath lthe crucible is mounted a:

gas burneror'other lheating' element l2 to which" fuel is supplied'for heating thecru'cible for melt-A` ing the type metal, lead, or similar soft metal alloys capable of fusion or melting at moderate temperatures and having a fair degree of tensile strength when cold, which metals are used in forming the strip. The crucible is provided with an outlet passage or spout I3 communicating with the lower portion of the crucible and extending laterally therefrom. The inner end of the passage communicates with the lower end of a pump cylinder I4, which is disposed in the body of the crucible and forms an integral part of the lower portion or bottom thereof. A piston or plunger I5 is slidable within the cylinder and is actuated by means of a connecting rod I6 extending upwardly from the piston and connected to one end of a lever I'I which is fulcrumed between lugs I8 formed on the upper end of the crucible body. The lever II is actuated by means of a push rod I9, which is connected with the outer end thereof and extends downwardly below the table top to a suitable crank or cam mechanism I9a which causes reciprocating movement of the push rod and thus, likewise, causes reciprocating movement of the piston I5 in the cylinder i4. Such reciprocating movement of the piston lifts the piston until it is positioned above a lateral opening 20 in the side wall of the cylinder, whereby molten metal may enter through said opening into the bore of the cylinder, whereupon downward movement of the piston will force the metal outwardly along the passage of the spout I3 in the usual manner.

A rotatable ported cylindrical plug valve 2I is mounted in the spout passage I3 for controlling iiow of molten metal through the passage of said spout. A valve stem 22 extends upwardly from the valve plug to a point above the upper end of the crucible and is provided with a handle 23 for manipulation by the user of the device.

A nozzle or tip member 29 is screw-threaded into the outer end of the outlet spout or throat I3 from the Crucible and has an axial flow passage therethrough for permitting the molten metal to flow outward through the nozzle and into the bore or shaped channel of a die or mold 3l which determines the form of the strip of type metal produced by the machine. The extreme outer portion or tip of the nozzle is preferably substantially hemispherical in configuration, and this hemispherical tip end of the nozzle engages in a concave or frusto-conical opening formed in the entrant end of the die or mold. The details of structure of the die or mold and the cooling system therefor are not essential to this invention, and may comprise any suitable arrangement, though the structure of the die and cooling system shown and described in my co-pending application for United States Letters Patent, Serial No. 20,855, filed April 14, 1948, is preferable. A clutch and pulling mechanism (not shown) of any desired suitable type, is mounted on the table top I I near the exit end of the die for positively drawing the strip T of type metal from the die in the usual manner. The strip so drawn from the die may subsequently be cut into sections of any predetermined desired length by a cutting mechanism (not shown) of any suitable or usual structure.

In the forming of the strip of type metal, the metal supplied to the die enters the bore or channel of the die in molten form and is caused to solidify or set adjacent the outlet or exit end of the die channel, such solidification or setting being eiected by cooling means 30 in heat-exchanging relationship with the die. Since the formed strip must be pulled from the exit end of the channel through the die, it becomes readily apparent that the presence of lubricant in the channel of the die is desirable for facilitating the passage of the solidified type metal through the die. The drawing of the formed metal strip from the die may thus be facilitated by introducing a suitable lubricant, such as engine oil or the like, into the spout, I3 so that portions of the lubricant will be carried into the die channel along with the molten metal from the spout passage. It is also important to note that the quantity of lubricantl admitted to the die must be very accurately controlled in accordance with the amounts required for properly lubricating strips of various thicknesses, etc.

For so supplying lubricant, the lubricating mechanism L has been provided. The lubricating mechanism includes a cup or container 40 having an elongate cylindrical tube or conductor 4I extending axially downward from its lower end and containing a flow passage 42. The portion of the tube adjacent to the bottom ofthe cup is enlarged in diameter and provided with external screw-threads 43, whereby the tube may be inserted into and secured in an opening 44 in the housing 45 for the outlet throat from the crucible and extend downwardly therein. A cap or cover plate 46 is removably positioned on the upper end of the cup 40 and held in place thereon by means of screws 41.

A valve body or housing 59 is screw-threaded onto the lower end of the tube 4I and forms a downward continuation of said tube, the lower` end of said valve body terminating in the throat passage I3 from the crucible to the outlet nozzle 29. The valve body is provided with an axial bore 5I which is reduced in diameter throughout its mid-portion so that an upwardly facing valve seat 52 is formed near the upper end of the housing and a downwardly facing valve seat 53 is formed near the'lower end of the housing. An elongate valve plunger 55, having a diameter smaller than the bore 42 of the tube and larger than the reduced bore 5I of the valve housing, is freely movable longitudinally of the tube into and out of engagement with the upwardly facing seat 52 of the valve housing. The upper end of the valve plunger 55 extends upwardly through an axial opening 55 in the cover 46 and is provided with external screw threads at its upper end for receiving an adjusting nut :51 for purposes which will be hereinafter described. A helical coiled spring 58 surrounds the valve plunger and is confined between the bottom of the cap 46 and a flange or ring 59 which is riveted or otherwise secured to the valve plunger at a point spaced above the bottom of the cup 40 when the! plunger is in its lowermost position. The spring exerts its force to constantly urge the valve plunger into engagement with the upwardly facing seat 52 in the valve housing 50 for controlling flow of lubricant from the cup 49 through the tube 4I and into the reduced passage 5I of the Valve housing.

An elongate substantially L-shaped lift .rod 60, has a bifurcated end 5I on its short horizontal portion, and the valve plunger 55 extends upwardly between the arms of the bifurcated end of such lift rod with the nut 5T above the arms, as clearly shown in Figure 2. The elongate vertical portion of the lift rod extends downwardly through an opening in a guide plate 62 secured by means of bolts 62a to the upper end of the housing .45, and then extends on downwardly through an opening in the table top II. A stop Washer or ring 63 is adjustably mounted on the lift rod above the table top by means of a set screw 64, for limiting downward movement of the lift rod. A roller wheel 65 is mounted on a transverse pin 66 at the lower end of the lift rod and is positioned to be engaged by a cam pin 61 carried by a rotatable follower disc 68 forming a part of a Geneva movement mechanism. I

` The follower disc 68 is provided with a plurality of uniformly spaced notches 69 in its periphery, and between the notches the periphery of the disc is formed with concave sections 10, whereby such concave sections will engage and ride upon the circular surface 1I of the actuating disc 12 of the Geneva type movement. The actuating disc is provided with an annular flange 413 along one side, and an actuating pin 14 is carried by the flange and adapted to engage in the notches 69 of the follower disc to cause the follower disc to be turned through a predetermined number of degrees. The circular surface 1I of the actuating disc is cut away adjacent the pin 14 to permit the points on each side of the notches in the follower disc to pass when the pin is engaged in one of the notches, so that the next adjacent concave surface V1I) is turned into contact with the circularsurface 1I of the actuating disc. Manifestly, the actuating disc must be turned through a number of rotations equal to the number of notches 69 in the follower disc to cause a single rotation of the follower disc. l

The actuator disc is mounted on the drive lshaft 15, which actuates the other parts ofthe strip casting machine and more particularly which drives the cam or gear mechanism which causes reciprocation of the push rod I9 to actuate the piston I5 of the molten metal pump. The follower disc 61 is mounted upon a stub orjack shaft 16 extending parallel to the main drive shaft and spaced therefrom a distance suiicient to permit the co-action of the follower .disc and the actuator disc just describede.

The foregoing constitutes the usual Genevatype movement, and causes intermittent movement of the lift rod 60 when the pin 61 engages the roller wheel 65 at the lower end of such lift rod. It will be seen, therefore, that the lift rod 60 will be lifted by the pin 61 one time for each six revolutions of the principal drive shaft 15 in the form of the movement illustrated in the drawings. Manifestly, the number of notches 69 and concave faces 1D formedA on the follower disc 68 may be varied from the number shown, to obtain different ratios between the revolutions of the principal drive shaft and the lifting of the lift rod. Also, it will readily be seen that any other suitable mechanism for causing intermittent movementy of the lift rod 60 may be employed rather than the Geneva movement illustrated.

When the lift rod 60 is elevated by the pin 61, the bifurcated end 5I of the horizontal porthe roller 65 at the lower end of the lift rod, the rod will drop downwardly until the stop ring 63 engages the upper surface of the table top I I of the strip casting machine, and the bi-f furcated end 6I of the lift rod will be normally spaced slightly below the nut 51 on the valve plunger. The valve plunger is normally con'- stantly resiliently held in engagement with the tion of the lift rod will engage beneath the nut 61 threaded on the upper end of` the valve plunger 55, and will lift the valve plunger away from the upwardly facing seat 52 in the valve housing 50. The distance which the plunger will be lifted may be variedand controlled byV adjusting the position of the nut 51.-,on theY threaded upper endof the valve plunger.V :When

upwardly facing valve seat 52 by means of the helical spring 58 acting downwardly upon the flange member 59 carried by the plunger, so that the oil or any other desired lubricant contained in the cup 40 will be prevented from flowing from the bore 42 of the tube 4I into the reduced passage 5I of the valve housing until the plunger is lifted by the lift rod in the manner just described. Furthermore, the engagement of the valve plunger with the seat 52 will also prevent entrance of molten metal into the bore of the lubricant tube 4 I.

It is preferable that the movement of the lift rod which elevates the valve plunger to permit' lubrficant from the reservoir or cup to flow into the throat passage be so timed with respect to the movement of the piston I5 of the molten metal pump in the crucible that the valve plunger will be elevated for only a short portion of the time during which the piston is moving upwardly to draw molten metal from the crucible into the pump cylinder and the molten metal in the throat passage is under suction. With the valve plunger so elevated to open the passage through the valve seat, lubricant from the reservoir and lubricant tube 4I may flow past the plunger and seat and into Ythe throat passage.- The amount of lubricant permitted to flow past the plunger and seat is therefore controlled by the'interval of time during which the plunger is lifted off such seat, and lubricant cannot flow from the reser' voir into the throat passage at any other time.

For preventing molten metal from the throat passage from backflowing upwardly into the reduced portion 5I of the bore of the valve housing, a check valve float or closure member 83 is movably mounted in the lower portion of the valve housing below the downwardly facing seat 53 formed therein, The check valve float is provided with a conical seating surface at its upper end which is arranged to engage against the seat 53 to prevent upward flow of molten metal therepast. The check float is maintained in place in the lower open end of the valve housing by a small transverse pin 82 fixed across the lower end of the housing and supporting and limiting downward movement of the float. The pin permits the float to move a sufficient distance below the seat 53 to allow lubricant to pass from the reduced portion of the bore of the housing into the throat housing, but when the molten metal is placed under pressure by the downward movement of the piston of the molten metal pump the float will be lifted back into engagement with the downwardly facing seat to prevent the molten metal from flowing into the reduced passage of the valve housing or to the valve plunger 55. Since the check float is preferably formed of steel cr similar metal, it will float upon the molten type metal and will normally engage against the downwardly facing seat 53. However, when the pump piston is moved upwardly to draw additional molten metal into, the cylinder a suction is created in the throat passage which will draw the check float downwardly away from the seat and permit lubricant containedl in the bore of the pin 61 has moved out of engagement vwith 7s the valve housing to be drawn past said float and aange@ im@ fine breiten' metal in the 'throat passage.

Wheifthepiston-'again 'moves downwardly, presfsiire is Yi'eap'plied to Ithe molten metal and the 'check o`a`t lis lifted back into engagement with 'the 'valve seat 53, v'and the lmolten metal is `thus pievbrited from 'entering the 'bore of the housing. 'Any incitan inetal passing the check oa't will, fliowev'e'r, be prevnted'from entering Vthe bore of the lubricant tube 41 'by 'the valve plunger 55 enfgagedagain'st the upwardly facing valve se'at 52'. -I-n '`iiect, therefore, the reduced portion 5i of the l-borefof the valve 'housing forms a small secondary lubricant clhamberfseparated from the lubricant reservoir vor cu-'p 40 by the engagement of the valve lplunger 55 'with the upwardly facing seat 52 at the upper end of the valve housing, and separated from 'the molten metal in the throat passage bythe check 'float 80 engaging the downwardly facing seat 53 'at the flower end of the housing.

Therefore, rwhile 'the molten meta'l'in the thi-'oat passage is :under pressure Aapplied by the down;- ward-stroke of the pump piston the molten metal cannot yenter "the lreduced 'passage or secondary cham-ber 5|, or if some metal does pass such checkv float the valve plunger 55 engaging the seat 52 prevents such metal from entering the boreof the lubricant tube and the reservoir. Furthermore, when the pump piston is moved upwardly to draw iadditional molten metal into the chamberi nto the throat passage until the valve .z

plunger 55 is lifted by the lift rod. As has Yalready ybeen pointed out, the valve plunger is not lifted except during a lshort interval of time during the upward or suction stroke of the pump piston, so thatthe passage through the upwardly facing seat is open during only a small part of the time that the check float is open. Thus, the lubricant permitted to pass from vthe reservoir through the secondary chamber into the throat' passa-ge is limited and controlled in amount by the period of time during which the valve plunger :is elevated. Also, a small portion of the lubricant will be retained in the secondary chamber 5l when the check iloat again seats against thedownwardly facing valve seat, and this lubricantwill pass into the throat passage during subsequent opening movements of the check iioat occurring when. the valve plunger 55 is not lifted. Thereforathe quantity of lubricant admitted into the molten metal in the throat passage is stricth controlled by the valve plunger, and lubricant is not, admitted to the passage except duringrytheY suction stroke of the molten metal pump piston.

Due to the fact that the lubricant cup 46 and the lubricant conductor tube il a-re supported in the housing i5 by means of the screw-threaded engagement of the enlarged portion vof the tube with the housing, it will readily be seen that the cup, tubejand valve housing 55 may be lifted from within the opening ifi after the scret;v threads -have been disengaged. Such removal of the lu-bricator provides access to the valve housing, whereby the seats and check float may be renewed or the housing replaced, if desired.

From the foregoing, it will be seen that an improved lubricating device has been provided for feeding lubricant into the strip forming channel of the die of a strip casting machine for making printers leads, slugs, and rules and the lll 'lile'gfsaid lubricating mechanism havin'giva" Jmeansfior-positively Acontrolling the admi on of lubricant 'to the channel of the die of the strip forming machine. 'It will further be` seen that valve ans Hof the lubricating mechanism is v ently restrained in closed position, and is open d only at predetermined intervals 1t 'lubricant through the small 4secondary chamber vintothe throat passage of thev machine; Further, they lubricating mechanism has been provided -iri'eans l'for preventing backeiiovv of -fli-ibricant and molten metal into the body of the `Iubric'a-to'r mechanism. The provision for controlled opening of the valve plunger con# trolling vfilo'w o'f lubricant from the reservoir; combination with the secondary chamber, provvides for strict control of the amount of lubricant adfiiitted to lthe' throat passage to pass with the `"riiolten fr'netal through the die channel. It'wili also Abese'en that the valve ymechanism is operated at intervals which preclude the admission 'of molten meta-l into Ythe valve housing tor lubriicater body; that the opening of the valves'is so controlled that undesired ow of nuids in either direction is prevented; and, that the lubricator mechanism is readily adjustable and removable, .if desired. A

The foregoing description of the intention is explanatory only, and changes in the details "of the construction 'ilhistratedmay bemad'e by those skilled in the art, within the scope of :the appendedfclaims, 'without departing from the spi-rit of the invention. i

What I claim and desire to secure by Letters Patent is:

, l. In a strip casting machine having a crucible for containing molten metal and having a sage from the crucible to a strip forming die and having a molten metal pump for forcing molten metal vfrom the crucible through the passage 'tof the die, aflubricating mechanism for introducing lubricant into vthe passage from the cruciblel to the die which includes, a lubricant reservoircup, a conductor tube from the reservoir 'cup to .the molten metal passage of the machine, upwardly: operable downwardly closable valve `nfiembers 'in the conductor controlling o'w of lubricant from' the reservoir to the molten metal passage,V a spring inthe reservoir cup normally biasing thev valve members toward closed position, a lift rod connected with the movable valve member for lifting said movable valve member against the action of the spring, and an intermittent move,- nnt `rnchanism for lifting the `lift rod and operated :in timed relationship with the movement of the molten meta-l pumpI for opening the valvemeans "at predetermined desired intervals to 'admit lubricant to the molten metal passage,l a vcheck valve in the conductor tube spaced from the first-named valve members for preventing 'of molten metal into said conductor, me

boreY of the 'conductor between said nrstmamed valve members and said check valve constituting a secondary lubricant reservoir.

Alubricatig mechanism for a strip casting machine 'having a melting pot with an outlet passage therefrom to a strip forming die which includes, a lubricant container having a ldowncommunicatir'i'g'v wardly eiitending conductor therewith, a'valve `housing removably connected nig 'with the outlet passage from the "melun-g' pet' of the strip casting machine whereby lubricant from the container may pass through the conductor and valve housing to the outlet passage, a downwardly movable valve member in the lubricant conductor engageable with the upwardly facing seat in the valve housing, a spring in the lubricant container engaging and normally biasing said valve member to closed position in engagement with said upwardly facing seat, and an upwardly movable check Valve member in the lower portion of the valve housing below the downwardly facing seat engageable with said downwardly facing seat for preventing back flow through the valve housing and conductor to the lubricant container.

3... A lubricating mechanism for introducing lubricantl into the passage from the crucible to the die o'f 1a strip casting machine which includes, a lubricant reservoir cup, a conductor tube from the reservoir cup to the molten metal passage of thejmachine, a valve housing removably. connectegLto the lower end of thefconductor tube and having a flow passage therethrough with an upwardly facing valve seat and a spaced downwardl" Afacing valve seat formed therein; an elongate valve plunger movable vertically in the and biasing the plunger into engagV HARRY "L. HORN.

REFERENCES CITED The following references are of yrecord in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,438,951 Elrod Dec. 19, 1922 1,466,125 Faupel Aug. 28, 1923 1,567,363 Elrod et al. Dec. 29, 1925 1,800,938 Hedly Apr. 14, 1931 1,913,945 Morris et al. June 13, 1933

Images