US2942718A - Cooling system for foundry molds - Google Patents

Description

June 28, 1960 E. BUHRER COOLING SYSTEM FOR FOUNDRY MOLDS 3 Sheets-Sheet 1 Filed Aug. 28, 1957 June 28, 1960 E. BUHRER COOLING SYSTEM FOR FOUNDRY MOLDS 3 Sheets-Sheet 2 Filed Aug. 28, 1957 INVENTOR. A-w/w/v Edy/ii? June 28, 1960 E. BUHRER 2,942,718

COOLING SYSTEM FOR FOUNDRY MOLDS Filed Aug. 28, 1957 s Sheets-Sheet a tgfgfililllililiiiiiIIUIlIIIB fliiilflilillillli lililifi IIIIIIIIZIIIIIIII! IIIIZlZIIiIIIIEIIiIIIII IN VEN TOR. 52m Bi/mm BY WW2 nited States The present invention relates to a transporting system for the handling of articles, and more particularly, to a system for transporting and transferring foundry molds from and to conveyors or like support means.

It is well known that the molds employed in metal working foundries, after the casting operation has been performed on them, are permitted to travel on a conveyor or track along a predetermined path and for a desired period of time, in order to permit the cooling down of the casting molds to a state where the casting may be unpacked without any risk or danger of damaging the castmg.

It has been found desirable to unpack each casting mold as rapidly as possible in order to retain the maximum quantity of the admixtures in the molding sand, namely the coal dust and cementing clay. Since thinwalled castings may be unpacked much sooner after the casting operation than thick-walled castings, due to their increased cooling rates or solidification velocity, it is therefore desirable to provide some means of conveying the thin-walled castings from the transporting system to the unpacking station as quickly as possible in order that they may be unpacked.

As a result of the different cooling periods required for the various size castings contained in the molds and which are carried on a feeding or supply conveyor, a number of solutions has been proposed in regard to the removal or storage of the casting molds which require the greater cooling time.

One attempted solution to this problem was that the casting molds which require longer cooling periods were laterally shifted from the main supply conveyor and piled onto another conveyor track and thence to an unpacking station.

Another known solution to this problem provides for a vertical storage rack, wherein are placed the casting molds which require longer cooling periods, their transportation from and to the conveying track being performed by an elevating mechanism.

These various solutions to the aforementioned problem have the disadvantage that the transferring systems are comparatively complicated and will not permit the use of a completely automatic conveying system since certain steps during the transporting of the molds from the pouring station to the unpacking station must be achieved manually.

It is therefore an object of this invention to provide means elfectuating the transfer of articles having different cooling rates between the working stations of a foundry in a highly eificacious and reliable manner, without necessitating the use of auxiliary storage means as was heretofore known.

It is another object of this invention to provide means permitting the automatic transfer of castings having different cooling rates between the various operating stations.

It is a further object of this invention to provide means contributing to a positive control of the movement of the molds between the desired operating stations.

An ancillary object of the invention is the provision of means permitting the transfer of articles between working stations of a foundry in accordance with the movement of a feeding member.

atent O 2,942,718 Patented June 28, 1960 The present invention provides a foundry with a superior transferring and transporting system capable of highly efficient operation, which system is extremely compact in its construction.

Therefore, the present invention utilizes a plurality of cooling conveyors which are interposed between a feeding and a delivery conveyor, the number of said cooling conveyors being a function of the various existing cooling periods. The molds which are carried by the feeding conveyor are arranged in a certain sequence and periodically fed onto the delivery conveyor from the cooling conveyor in accordance with the respective cooling rates of the castings, so that each cooling conveyor only contains those castings having the same cooling rate. The feeding of the castings from the cooling conveyor to the delivery conveyor is achieved by means of a lifting device. Prior to the automatic operation of the device being commenced, different numbers of molds or empty flasks are placed on each of the respective cooling conveyors. Thus, when the automatic operation begins, the number of molds which at any time is transferred from the cooling conveyor to the lifting device may be the same as the number of molds transferred from the feed ing conveyor to the cooling conveyors.

The above and other objects of the invention will become further apparent from the following detailed description, reference being made to the accompanying drawings showing preferred embodiments of the invention.

Fig. 1 shows schematically a plan view of a first embodiment of the invention;

Fig. 2 is an enlarged sectional elevational view showing details of the lifting device seen in Fig. 1;

Fig. 3 shows schematically a plan view of another embodiment of the invention; and

Fig. 4 shows details of the cooling conveyor employed in Fig. 3.

Referring now to the drawings, and more particularly to Figs. 1 and 2, the transporting system comprises a feeding or supply conveyor 1 which continuously feeds the casting molds 2 which have previously been filled with a molten metal, as for example, iron, and are moving in the direction of arrow 3. Disposed substantially perpendicular to the direction of movement of the casting molds 2 on the feeding conveyor are feed rods or push-off devices 4, consisting of a piston and cylinder arrangement, wherein the piston is actuated by means of compressed air or any other suitable fluid medium. A pressure valve 47 is located adjacent to the feeding conveyor 1 and one of the push-off devices 4. The pressure valve receives a supply of compressed air from a source (not shown) and subsequently, feeds said compressed air to the push-01f devices by means of conduits 48 which are disposed between the push-off devices 4 and the pressure valve 47. The withdrawal or retraction of the pistons of the push-01f devices may, for example, be elfectuated by return springs or any other suitable means. The supply conveyor 1 is provided with' stop dog or trigger cam means 45, 46, which are spaced a predetermined distance from each other on the supply conveyor.

Spaced from the supply conveyor 1 and lying in a plane which is substantially parallel to said supply conveyor is a delivery or discharge conveyor 13 which leads to an unpacking station (not shown in the drawing). A number of roller conveyors 5, 6, 7, 8 provided with roller means- 9 are interposed between the supply conveyor 1 and the discharge conveyor '13.

The number of such roller or cooling conveyors is directly proportional and equal to the number of different cooling rates of the castings. Each of the cooling conveyors is adjustable so that its position'or angle of inclination may be altered.

i; V i a 2 r 3 7 These cooling conveyors are further provided with stop members or holding-devices 23, the construction of which is already known, said stop members may preferably be located at the respective ends of the cooling conveyors and reh 'ote'from the'fedingofsupplyconveyor li "The stop me'rhhers are actuatedw means-or compressed air delivered ffom the pfessiirevalve erthron h' eondnitasz Thus, as the trigger cam 45 passes tlfqpressnre valve dfi the lat-tr 'is-opened; andfeed's asupply of compressed air'to-the push off devices4=by means ofcon duiti48 and' '4 7 of casting molds, for example four casting molds as seen in Fig. l, which have arrived in front of theroller or cooling conveyors 5-8 onto the latter, the casting molds moving down towards the locking or stop devices 23 or to the last mold located onitherespective cooling conveyors,' either due. to -their own weightjor hytitilting'cthe roller conveyor. Each roller,ortcoolingconyeyon; is ;sup;

7 plied .with. casting. .moldschavinggthensame;;cooling;.rate.

have'f been *opehedfpermitthe"casting nroldsftojbe' trans: ferred from -the"-cooling' conveyors onto the lifting con- The trigger cam 45 simultaneously actuates the'zholdi'ng devices 23 sothat-said holdingedevices.are'opened to perrnit imovementof a group, of 1 four. casting, moldsmntq :the lifting stand, the latterbeing, in position; to receive said molds. Continued'rnovement of the. supply conveyor I 1 causes trigger cam 46 10 deactuate valve 47 so th'at -the veyor= lllithe-construc tion of thelatter Will hedescribed shortly; Furtherlnirovementof the supply. conveyor car; ries trigger -cam 46 past 'thevalve tfl; whereby the latter is deactuated, cutting-oifihesupply "ofcompressed air to both the pnsh-ofPdevices 4" the holding devices in order to retract the} iaisons"; bymeans of the springs and to close the holdi'n g deyices, respectively i The aforementioned lifting conveyor 10. is located adjacent the holdin'g de'vices" 23 is arranged in alignment with'the 'delivery f conveyor; 13. 'Thepush-off devices 4 displace the castingmolds'2 traveling on supplyfconveyor pnslfoif'devi'cesd v are-retracted and the holding-"devices" 23' are closed: The liftingconveyor 10 receives the feast-'- thata-new group-ofcasting moldsis pushed-onto the lonto the cooling conveyors s s; so that the molds'move towards the lifting conveyor l0i (in the direction of areitherf dtle to: their own. weight or'by adjusting the angle; of inclination ofsaid cooling conveyors. The lifting conveyor ,10 receives the: casting molds from the cooling conveyors'i s'and' imparts amovement to said casting molds in the directionof movement of the de-' livery conveyor 13; namely; in thegdirectioniof arrow'36.

The lifting conveyortorstandf 10; shown in an enlarged scale-and in sectioninf Fi'gii Z, consists; of a frame '14 made of steel or the'xlike, l A'plurality of transverseroller tracks 1 1 in combinationawith IOlllS' 121 is carried by the frame, rollers 12 supporting chain wheels 18 which are laterally disposedon said rollers. A motor 16 drives,

y meansof a Sprocket or flanged gearlfia; a chain 17 which is inengagementwith" the chain wheels 18 in order to rotate marchers- 2, the transverse rollers being spaced from-each othen V I 7 l A hydraulicallyg actnated cylinder 19"is1ocated adjar cent the lifting:conveyon10fand5slidably supports a pistonrodll which is adapted to'move along itslongitudinal axis)? A plurality of'bellfcr'ahk'spr' levers 20 arepivotally 1 seciir'edto the' framejlibwfmeans off thjeirshorter. arm. 7 e l e ia io s dibi lh a s' i ifid nficted t hth'ei piston rodjzl so' that upon longitudin'almovement of said] piston rod' in on'e 'directionjthe jconveyor 10 raises l the casting molds whichare supported on the rollers 12,

whereas movement; of' said piston rod in thejop'p'osite' direction lowers" said lifting conveyor, the bell cranks piviotingabout tiIG aXiSTZZZ Whenthe ljfting'standjs in t its'raisedposition, as seen inFig, 2, the motor 16 is actuated in 'order to impartja, rotationalimovement to the rollers 12; thereby moving the casting molds onto the,

along the supply conveyor 1 move towards the pressure valve 47; Prior to the automatic operation of the de-,-

' vice being commenced, different numbersjof molds or.

emery flasks are placedjfor ,preloadinggon each 'oftthe r semble-c o in o i Upon caching thepres'sure' valvetrigger cam 45 "aetuy ates sai'd valve so that the"push ofhdhiceslinove a; gfoupi the supply'eonveyorl'from thelpouring station towards 'thefpush-oif' devices}; ,The trigger, cams 45 and; which have .p'reviously been spaced at the desired location cooling 'convey'orsa". The lifting K conveyoris'then' hoisted by "means of thepressure cylinder :19; and the-motor-16 I is actuated in order todrive the-rollers 12, @whereby -'-thecasting molds'a re conveyed onto the discharge conveyor 13; which leads to the unpacking station; Thisoperationis repeated-as each trigger cam and Hi-reaches the pressure valve V V Thus itgwill bereadily apparent thatthe'number of niolds, which at any time 'is transferred-from the cooling conveyorto the lifting device-may be the same-as the numberiof'molds transferred atthe sametime-from thefe'edingconveyor to the cooling conveyor? As a-result= of placing {staples ct -molds or different numbers OfIl'lOldS or empty flasks for thefpurpose' of preloading onto the respective cooling conveyors prior to the automaticoper-z ation of the device-upon actuation" of" the device-fourmolds (see'Fig. '1) are transferred from the-feedingdevice to the cooling conveyor, and four of the-previousflasks will at the same 'time'be transferred to the lifting device'from the cooling'conveyor: The casting molds which actually require cooling -will remain on one specificconveyorduring a time which isreqnired to remove therefromthe empty flasks previously'placed thereon; Since this numberof empty flasks or molds-is diiferent=for-each The spacing of the trigger cams 45, 46 along thecon veyor can be altered so that any desired number of pushoffdevices and coolingconveyors'can be used. It is desired to have as many cooling-conveyors as there are various cooling rates, although it is'pos'sible to have'an excess number of cooling conveyors so'that some-.of the cooling conveyors carry molds having the same cooling v rate. V

In'the-embodimentshown in Fig. 3, the supply conveyor'25 is disposed adjacent a'pluralityof substantially U shaped roller or cooling conveyors 28-31.. Push-off devices 26 similar to those shown'in Fig. 1 shift the'cast ing molds 27 as they move past the push-off devices 26 onto thedesired cooling conveyors 28, 29, :30,'31. -The pressurevalve, thetriggerzcamsand; the respective con-w duits ilead-ing to. the push-off devices, ;and/ the holding, devices, as shown in Fig. l, have beenzomitted from Fig.

3 'for the sake of clarity.-

A lifting roller conveyor 32 which is similar in' construction to the lifting-device discussed in Fig, 2receives the castingrnolds from the roller conveyors and deposits them onto the discharge conveyor track 33. i

The transfer system shown in Fig. 3 differs from that has two bends or deflections of approximately'degrees.

The arrangement of these roller conveyors in this manner permits the use, of conveyors which have different lengths, thereby afiording more ,spacqfor the storage of the molds during the cooling operation, and especially those molds which require the greater cooling time.

Fig. 4 shows a portion of a cooling conveyor shown in Fig. 3 and how the deflections of 90 can be obtained in actual practice. A group of rollers 49 lying in a common plane and defining a straight portion of the roller conveyor 31 are inclined in order that casting molds 2, shown in dotted lines in Fig. 4, will move thereon due to their own weight and to the slight inclination of the rollers 46. In front of the bend or deflection there is arranged a group of rollers 41 which are driven by a chain 42 by means of a suitable motor or prime mover (not shown). This group of rollers 41 is arranged so as to have a small rise or upward inclination of about 0.2%. The casting molds 2 are moved from the rollers 41 to the group of rollers 43, which form the bend or deflection in the conveyor, the upper edges of these rollers 43 lying in a horizontal plane. The casting molds upon passing over this group of rollers 43 are turned approximately 90 from their initial direction of travel, this group of rollers being also driven by a motor or prime mover.

Disposed adjacent the last roller of this roller group 43 and at the termination point of the bend is a group of rollers 44 which are similar to rollers 49 and form the straight portion of the cooling conveyor, said rollers 44 being inclined in a downward direction to facilitate movement of the casting molds 2 towards the other 90 deflection which is similar in construction to the one previously discussed. At the termination of the deflection and adjacent roller 45a there is suitably installed and located a switch (not shown) which is actuated by the molds 2, in order to disconnect both of the driving motors or prime movers for the roller groups 41 and 43. The actuation of said switch occurs when the cooling couveyor including the roller group 44 cannot receive molds any longer. As a result of stopping the motors which drive the roller groups 41 and 43, it is possible to prevent an agglomeration or collecting of the molds at the bend of the cooling conveyor, so that the movement of the molds on the cooling conveyor will not be hampered or interrupted.

It is also possible to operate a cooling track, as shown in Fig. 3, with only one or two roller conveyors and to keep in readiness one or more roller conveyors which will be used as supplemental cooling conveyors when a pattern modification requires a cooling period for the newly formed molds different from that which has hitherto been run.

It is also to be noted that in the embodiments of Figs. 3 and 4 it is possible to selectively actuate the respective holding devices in order to selectively transfer the cast ing molds from the respective cooling conveyors to the lifting device.

The transferring system of this invention can also be arranged in such a manner that one more cooling conveyor can be installed in excess of the number of different cooling periods required for the molds. This supplemental roller conveyor should he installed when there is a reduction in the cooling period of the Thus a principal advantage of the present invention is readily apparent, namely, a smooth course of automatically and mechanically conveying casting molds between the pouring and shake-out stations of a foundry, wherein said casting molds have different cooling rates. The transferring system of the present invention, and particularly the cooling conveyors require less space than the heretofore known systems used with molds having different cooling periods.

Various changes and modifications may be made without departing from the spirit and scope of the present invention and it is intended that such obvious changes and modifications be embraced by the annexed claims.

Having thus described the invention, what is claimed as new and desired to be secured by Letters Patent, is:

1. A system for substantially uniformly cooling foundry molds having a plurality of different cooling rates; comprising a feeding conveyor for carrying and moving molds in a predetermined path, a delivery conveyor spaced from said feeding conveyor, a plurality of cooling conveyors providing communication between said feeding and delivery conveyors, push-off means disposed adjacent said feeding conveyor for effectuating movement of molds onto the cooling conveyors, stop means located between said cooling conveyors and said delivery conveyor and coordinated with said push-ofi means to permit movement of molds already loaded onto said cooling conveyors from the latter to the delivery conveyor when the previously loaded molds have been cooled, and control means in registry with said push-off means and said stop means to periodically actuate and deactuate said push-off means and said stop means in accordance with the movement of said feeding conveyor, said cooling conveyors extending substantially in U-shaped formation, so that each cooling conveyor has a different overall length for storage of molds.

2. A system according to claim 1, said substantially U-shaped cooling conveyors having two deflections and being provided with rollers, drive means for driving said rollers which are disposed adjacent said 90 deflections, and switch means located adjacent said driven rollers to deactuate said drive means when said cooling conveyors are carrying a predetermined number of molds, in order to prevent overcrowding of molds on said cooling conveyors.

3. A system for substantially uniformly cooling foundry molds having a plurality of different cooling rates; comprising a feeding conveyor, a delivery conveyor spaced from said feeding conveyor, a plurality of cooling conveyors having respective first and second end portions, said cooling conveyors providing a path of movement for molds from said feedin conveyor to said delivery conveyors and being preloaded with a predetermined number of molds respectively, push-0E means disposed adjacent said first end portion of each of said cooling conveyors for causing movement of molds from the feeding conveyor onto said cooling conveyors, holding means located adjacent said second end portion of each of said cooling conveyors, a lifting conveyor located adjacent said holding means, and control means in registry with said push-off means and said holding means, to thereby permit displacement of molds from said feeding conveyor onto predetermined cooling conveyors in accordance with the respective cooling rates and with said predetermined number of preloaded molds and from the said cooling conveyors onto said lifting conveyor upon actuation of said push-off means and said holding means by said control means.

4. The method for substantially uniformly cooling foundry molds of various cooling rates; comprising the steps of preloading respective cooling conveyor means with molds according to the duration of cooling, placing heated molds on a feeding conveyor, transferring said heated molds from said feeding conveyor to said respective cooling conveyor means corresponding to their rates of cooling, subjecting the molds on said respective preloaded cooling conveyor means to cooling action for respective predetermined periods of time, and simultaneously transferring a single mold from the respective cooling conveyor means to a delivery conveyor as a mold is being fed to the respective cooling conveyor means.

References Cited in the file of this patent UNITED STATES PATENTS 1,558,691 McDermott Oct. 27, 1925 1,737,762 Howe Dec. 3, 1929 1,913,533 Brunner June 13, 1933 1,929,204 Jeifrey Oct. 3, 1933 2,071,859 Steiner Feb. 23, 1937 2,576,369 Sticelber Nov. 27, 1951 2,679,310 Lunn May 25, 1954

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