US2267677A

US2267677A - Sand muller

Info

Publication number: US2267677A
Application number: US305884A
Authority: US
Inventors: Baxter William
Original assignee: Crane Co
Current assignee: Crane Co
Priority date: 1939-11-24
Filing date: 1939-11-24
Publication date: 1941-12-23
Anticipated expiration: 1958-12-23

Description

Dec. 23, 1941. w. BAXTER 2,267,577

' SAND MULLER Filed Nov. 24, 1939 3 Sheets-Sheet 1 W. BAXTE R Dec. 23, 1941.

SAND MULLER Filed Nov. 24, 1939 5 Sheets-Sheet 2 Dec. 23, 1941. w. BAXTER 2,267,677

SAND MULLER Filed Nov. 24, 1939 3 Sheets-Sheet 5 Patented Dec. 23, 1941- SAND MULLER- William Baxter, Montreal, Quebec, Canada, as-

signor to Crane 00., Chicago, 111., a corporation of Illinois Application November 24. 1939, Serial No. 305,884

. 2 Claims.

This invention relates to a foundry sand muller having especially for its functionthe preparation or reconditioning of molding sand. .More particularly, the invention relates to a continuously operating type of sand muller as distinguished from those generallyreferred to as batch type mullers.

One of the more important advantages of the present invention lies in the provision of an apparatus in which one roller or ironer completely mulls or prepares a mixture of sand, clay and bond while the said mixture is making a single pass or contact thereunder.

Another object lies in the provision of an apparatus which will continuously and efficiently mull or prepare foundry sand for molding as the said sand is fed to the muller regardless of wide variations in the quantity of sand supplied to the muller for preparation.

A still further object of the invention is to provide a sand muller which utilizes a new type of mulling action, not heretofore available, for the -more efiicient treatment of the sand and clay particles whereby the clay is more evenly and thoroughly distributed in the sand. As hereinafter described in greater detail, the increased efiiciency of my mulling apparatus is derived from a novel brushing, crushing and tearing action imparted to the sand preferably by a specially constructed roller or ironer having a peripheral velocity which is not the same as the velocity of the'sand being fed to the said roller by a conveyor.

It is also a further object of my invention to provide a molding sand muller which is readily adaptable to being installed in existing sand reconditioning or transporting systems and which when installed requires a relatively small amount of power for its operation.

Other objects and advantages of my present invention will become apparent upon proceeding with the following detailed description of 'a preferred embodiment of the muller illustrated by the accompanying drawings in which:

Fig. 1 is a side view of the complete sand preparing unit.

Fig. 2 is a plan view thereof.

Fig. 3 is a fragmentary end view showing the preferred relative positioning of the respective sand tempering belt, the mixerv and the cooling belt. 1

Fig. 4 is a magnified fragmentary plan view showing in detail the mounting of the roller or ironer above the tempering conveyor belt.

Fig. 5 is'a side view thereof.

Fig. 6 is a sectional view showing the preferred construction of the roller or ironer.

Like reference numerals refer to like parts throughout the various views of the drawings.

Referring to Fig. 1, the preferred and conventional type of foundry molding sand conditioning apparatus to which I adapt my sand muller comprises a rotary screen or riddle I covered by an open ended bottomless housing 2 both of which are positioned immediately above a portion of an endless'belt type conveyor or tempering belt 3. The said tempering belt extends horizontally from one end of the riddle and has a plurality of stationary sweepers 4 (more clearly shown in Fig. 2) superposed upon a central portion of the belt. At the extreme end of the tempering belt I place an independently driven roller or ironer 5 the construction of which will hereinafter be described in greater detail. Immediately below the extreme end of the tempering belt I place the inlet of a conventional mixer or beater 6 (more clearly shown in Fig. 3) which may comprise an enclosed rotatable worm screw or, if desired, may incorporate any other means for mixing or beating and advancing material within the mixer to the opposite side or outlet end 1 thereof. Adjacently below the outlet of the mixer 6, .I prefer to provide a conveyor or cooling and transporting belt 8.

The manner of operation of the hereinabove briefly described apparatus comprises supplying the riddle or screen I with used and/or new molding sand by any convenient means .(not shown) such as a hopper or a conveyor belt having a chute to direct the sand into the riddle.

The riddle, previously described as being rotary,

falls upon the tempering belt 3.

The belt 3 encircles a pair of journaled rollers l8 and. I9 and has a plurality of supporting rollers 2| which prevent undesirable sagging of the con-- veyor belt. The roller l8 has a belt tension adjusting bearing 22 and the roller l9 has attached to its axle 23 a pulley 24 which by means of the belt 25 is driven by the pulley 26 secured upon the driveshaftz'l. The rotational drive imparted to the pullley I9 is preferably clockwise whereupon the uppermost portion of the belt 3 will travel in the direction indicated by the arrows. Thus, sand falling upon the tempering belt from v the riddle moves with the belt past the sweepers 4 which thus effect an even distribution of the sand upon the belt.

Referring now to Figs. 4 and 5, the sand, after being swept to an even thickness across the width of the belt 3, approaches the independently driven roller or ironer 5 wherein lies the essence of my invention. The ironer 5 is rotatably mounted upon a pivotable framework 28- comprising a pair of arms loosely attached to thecountershaft 29, the latter being supported above the tempering belt by the'bearing brackets .3! and the stationary framework 32. The outermost end of the pivotable framework 28 carries a scraper 33, preferably, made of rubber, leather, or the like material, which extends the length of the ironer 5. A pair of adjustable stops 34 extend upwardly from the general framework 13 and abut thepivotable ironer-carrying framework 28, maintaining the latter in its lowered position so that the ironer will not come in direct contact with the belt 3. It has been found desirable to make the stops 34 adjustable so as to maintain the periphery of the ironer 5 pref erably about A-inch above the tempering belt, although the latter distance may be varied;

The independent drive of the ironer 5 is provided for respectively by the pulley 35 upon the shaft 23, the crossed belt 36, the pulley 31 secured to the countershaft 29, the pulley 38 also secured'to the countershaft 29, the belt 39 and the pulley 4|, the latter being secured to the journ'aled shaft 42 of the ironer 5. Thus it can readily be observed thatvupon proper selection of the ratio between the diameters of the

pulleys

35 and 31 the peripheral velocity of the ironer 5 may be adjusted to anydesired speed and that the direction of rotation of the ironer will be counterclockwise. The apparatus has been found during actual operation to give satisfactory results in the mulling of sand when the lineal velocity of the tempering belt 3 is about 212 feet per minute and the peripheral velocity of the ironer 5-is about 230 feet per minute.

In operation, the sand upon the tempering belt after being swept to an even thickness by the sweepers 4 is fed under the ironer 5 the lower surface of which, by reason of its counterclockwise movement, is traveling in the same direction as the sand but preferably at a greater velocity than the sand, whereupon the sand receives a novel brushing, crushing and tearing action which separates and intermingles the various particles constituting the sand mixture. Re-

silience in the action of the ironer is provided for ing belt 3 or else is scraped therefrom by the scraper'52. -The scraper 52 is preferably supported by the extensions 53 secured to the general framework l3 and comprises a toggle construction mounted upon the journaled shaft 54 which extends through the bearings 55 and 56.

A weighted lever 51 securedto one end of the shaft 54 is provided to maintain the scraper blade 58 normally against the tempering beltto remove any particles or wads of sand adhering to the belt. Satisfactory material for use. as a scraper blade 58 is hardwood; however, if desired, other materials may be used.

As more clearly shown in Figs. 1, 2 and 3, the sand after leaving the tempering belt 3 drops into a conventional mixer or heater 6, aspreviously explained, and, as it is advanced toward the outlet 1 thereof, receives a thorough mixing,

beating and fiufiing treatment which suitably prepares the sand for use by a foundryman in making molds. The mixer 6. is preferably provided with a belt drive 59. From the mixer outlet 1 the sand needs only to be transportedto the location of its use and in the event that it. must be taken some distance from the mixer, a

satisfactory method-of transporting and incidentally cooling the sand is provided by the belt conveyor 8 traveling around the roller GI mounted upon the bearings 62 and the framework 63.

by the tempering belt 3 which has no support ,directly beneath the ironer and by the pivotability of the framework 28 which allows the ironer to rise upon the occurrence of an increase in the thickness andquantity of sand upon the temper-' ing belt. Obviously, the free riding weight of the ironer and its framework thus assist materially in the mulling treatment of the sand;

The construction of the roller or ironer 5, reference being had to, Fig. 6, comprises preferably a hollow metallic cylinder 43 having an external covering of rubber or the like material 44. Heads and 46 are provided in the ends of the cylinder for the purpose ofmaking it a liquid-tight container and to provide supports for theshaft 42. The shaft 42 is journaled in the

bearings

41 and 48 and, as previously described, is driven by the pulley 4| and the belt/39. A removable plug 49, is provided in the head 46. for the introduction of a weighting material 5| such as water, oil or other liquidor granular substance within the ironer. The amount of said weighting material may, of course, bereadily determined by experiment taking into consideration the size of the ironer and the average condition of the sand passing under the ironer.

Attention-is again directed? to Figs. 4 and 5. The sand, after receiving the treatment afforded by the ironer. 5, either falls from the temper- Having thus described and illustrated a preferred embodiment of my mulling apparatus, I

wish it to be clearly understood that various changes and modifications of the construction may be made without departing from the spirit and scope of the invention as defined by the claims appended hereto.

' I claim:

1. A continuously operating type sand muller comprising screening means, a sand tempering and transporting belt encircling a pair of jour--' naled rollers, an ironer, the said ironer compris-n ing a rotatable roller, the said belt being horizontal and flexible or freely suspended in the region of the journaled roller adiacent'the said" ironer, a flexibly mounted carrying 'member for the said rotatable roller positioned-adjacent one of the journaled rollers of the said transporting belt, thesaid rotatable roller being mounted in spaced relation above an end flexible portion of pendently driven weighted roller mounted upon a pivotable carrying member in proximity to an end portion of the said conveyor and adjacent to one of the said pulleys, the said weighted roller being axially disposed from the said pulleys in a /direction toward the span of the said belt as defined by the space between the said pair of' pulleys, whereby upon the conveyance, of sand upon the saidbelt, the spanof the latter member is depressible over a section beneath and adja-'- cent to the said weighted roller, the said belt being horizontal and'fiexibly or freely suspended in the region of the journaled roller adjacent the said ironer, the said roller having a peripheral :velocity which is not the same as thevelocity of the said tempering conveyor belt.