US2345457A - Molding sand milling machine - Google Patents

Description

March 28, 1944. H L BURG 2,345,457

MOLDING SAND MILLING MACHINE March 28, 1944.;

H. L. BURG 2,345,457

MOLDING SAND MILLING MACHINE 4 Sheets-Shadi 2 Filed Nov. 13, 1942 March 28, 1944. H. l.. BURG MOLDING SAND M1LL1NG MACHINE Filed Nov. 1s, 1942 4 Sheets-Sheet 3 grwem/to/b ffomer u www# March 2s, 1944. H, L. URG 2,345,457

MOLDING SAND MILLING MACHINE Filed 13, 1942 4 Sheets-Sheet 4 54 7 Patented Mar. 28, 1944 UNITED STATES PATENT OFFICE MOLDING SAND MILLING MACHINE Homer L. Burg, Dallas City, 111.

Application November 13, 1942, Serial No. 465,493

(Cl. ,Z2-89) 17 Claims.

This invention relates to improvements in molding-sand milling machines, and is designed more particularly as an improvement upon a machine for similar purpose disclosed in my companion application, led December 4, 1940, Serial No.` 368,541.

The machine of the companion application is designed to condition the sand used by molders in foundry practice, being applicable for service with either the natural molding sands as well as with the synthetic molding sands, making it possible to provide the desired admixture of the latter in the heap position-due to portability of the machineand avoiding the necessity of transporting the heap to a milling machine for re-conditioning and then return to heap position for molding operations. The present invention is designed to produce similar service results, but, while operating on generally similar lines, presents certain features which make it possible for greater efficiency in operation and in transportation and storage. To produce the results under the changed conditions certain of the units have `been changed structurally and positionally and certain additions made, while one of the units has been omitted.

For instance, provision has been made for producing a more or less symmetrical heap of conditloned sand during the conditioning travel of the `machine over the unconditioned heap. To retain this condition of the heap the conditioning instrumentality is swung on and about its axis so `as to raise the conditioning brush above an unconditioned heap during the travel of the machine to its starting position for milling, the swing being through an arc of approximately l90 to the inactive position. To permit this, certain changes in the structural arrangement and loca-tions are essential in order to enable the `swing without interference, changes which aid in increasing the eiiiciency in operation; in addition, the dirigibility eiect has been increased to enable the machine to be more easily movedv vabout the iioor of the foundry and positioned tions with the power source, whether the latter be of the one or two unit type.

Generally, the machine, in service, utilizes certain of the fundamentals of the machine ofthe companion application, thus enabling it to treat different types oi sand, similarly to the machine of such application. However, one of the features of the companion machine-the additional material distributorhas been omitted,'in order to provide for the better balancing conditions, reliance being lplaced upon the usual methods of introducing the added material, such as distributing it on the iiasks for dumping with the sands used with the previous molding and casting. While the preliminary distribution is not as accurate as in the `companion application, it is sufciently so as to `provide for the proper admixture through by the brush action and the showering eiect set up on the sands in connection with the screen.

One of the features of the present invention pertains to the dirigibility control. The traction wheels are driven from the power source by individual drive rolls which can be rendered active concurrently or individually or rendered inactive as a drive, the selection being entirely within the control of the operator. Hence, it is possible to drive straight-away when servicing a heap, the speed of travel of machine and rotation of wheels being coordinated to prevent overload, disconnect the drive duringthe manual return, or swing the machine dirigibly by power source by the activity of the proper individual roll.

To provide for the swinging arcuate movement of the conditioning instrumentality, it is essential that, a zone of the instrumentality inrear of the brush do not extend beyond the major radius of the traction wheels-the swinging movement raises the front of the instrumentality and it must be possible for a zone of approximately of the rear of the instrumentality to swing through such arcuate path `.below the axle. This zone includes the screen, and because of this the latter is given adiierent form and speciiic location as compared with the companion disclosure; while the screen is usually removed during the return travel over the heap, it is possible that the heap conditions and the service may not require removal at times, and hence the screen is made to conform to this dimensional condition brought about by the arcuate swinglng of the instmimentality.

The instrumentality also includes a removable flexible heap-shaping apron or hood in rear of and overlying the screen. This apron, in service extends beyond the dimensional zone referred to, but inasmuch as it can be removed with the screen and/or be rolled up to be located within the dimensions, such apron projection will not aiect swinging of the instrumentality.

While the conditioning brush has the general characteristics of the similar brush of the companion application--formed of wire or bre bristles sufiiciently exible to permit ready passage over largerfobjects but capable of tossing smaller objects over the screen and into the collection zone, with the desired content thrown onto and through the screen in such manner as to tend to shower the conditioned sand to produce the working heap-certainchanges are made in structure of the brush to increase and permit maintenance of its stability vfor1 service.

Due to the fact that the screen is located within the limited dimension zone, it has been given a particular shape different from that of the companion application; g' in additionV it has, vbeen mounted to permit ready removal for cleaning,

l etc.; hence, it may be omitted in service, if the heap condition does not require its use, the apron operation of the drive rolls on the traction wheels will tend to swing the instrumentality frame on its pivot axle away from the instrumentality service position in the direction of inactivity. To prevent this, a drag structure is utilized, the latter being located in rear of .a vertical plane through the axis and, during service, riding on the ground oor; in case of tractionwheel stoppage the drag resists the swinging action of. the instrumentality; when desired swinging is to be had, the drag is moved toa raised position thus permitting the free swinging of the instrumentality. V Y .V

In addition to the above, certain'changes and additions have been made as to details which contribute to the operablity of the machine under the above conditions; these will .be pointed out in detail hereinafter, and are intended to beincluded within the objects 'of the invention..

To these and other ends, therefore, the nature of which will bernore fully enlarged upon hereinafter, said invention'consists in the improved constructionsl and combinations of parts, described in detail herein, illustrated in the vaccompanying drawings,v and'more particularly pointed out in the appended claims.

In theaccompanying drawings, in which 'similar reference' characters indicate similar parts in each of the views,

Figure 1 is'a'view partly in longitudinal section and partly in side Velevation 'of a machine `embodying the present invention' with "the parts shown in service position. Y

Figure 2 is a top plan View of the same.

Figure 3 is a-viewtaken on a different longitudinal section and showing the conditioning intrumentality shifted to its inactive position.

Figure 4 is a rear elevation, with parts broken 1 away, and in which the'instrumentality is in its service position. y

Figure 5 is a detail sectional view of the control means for applying power to the wheels.

Figure 6 is a-sectivonal view of a portion of the conditioning brush and showing the manner in which the brush elements are mounted.

Figure 7 is a detail View partly in section of a support connection.

As above indicated, the specific embodiment of the invention disclosed herein presents the general type of machine disclosed in the companion application-a machine capable of operating in connection with synthetic sands as well as the natural molding sands, the machine being operative to properly mill and distribute the added material when the heaps are being reconditioned. Certain changes'have been made to enable the machine to have the additional activities above pointed out. The following presents the details of construction:

The apparatus or machine includes a pair of traction'wheels lil, of a desired diameter, each of which has a tread of sufficient width to provide an inner surface lila with which a pair of drive rolls ii-one for each wheel-cooperate for advancing the wheels. The wheels lil are spaced apart a distance sumcient to straddle a heap, and

, carry an axle i2 arranged to provide and maintain the desired spacing of the wheels.

The axle i2 supports a frame formation I3, of semi-skeleton type, suitable bearingsV I3a being mounted on the axle to support the frame thereon in such manner las will permit the frame to swing on and about the axle at will. The frame provides the support for the various features of the conditioning instrumentalityl Because of the possibility of swing, the general arrangement of the instrumentality elements is such as to tend to balance the assembly and thus make for easier operation by the operator during service and for swinging between service and inactive positions in meeting the various conditions to be met.

Hence, the instrumentality tends to take on a zonal characteristic. For instance, :in service, the conditioning brush lll-'which operates in connection with the unconditioned heap and there- -metrically disposed above the axle; hence, the

two units are ideally located for service conditions, and tend to balance each other during the swinging movements. Similarly, the screen I6 and heap-shaping unit l1 are locatedat the rear, while the front carries the rolls Il and the control means therefore, and an extended steering handle arrangement for the operator, this general arrangement tending to Iaiord a somewhat similar balancing condition. Other features are present and so arranged as to aid in producing such balancing eiTect.

Since, as heretofore pointed out and as presently described in detail, the conditioning instrumentality is swung pivotally on and about the axle l2 when moving between service and inactive positions (the swinging is counterclockwise in Figure 1 when moving to inactive position), the zone content in rear of brush I4 is so formed and mounted that its maximum radius `from the axle is not greater than the radius of wheels l-in practice it is sufficiently less as to permit the instrumentality to swing without materially interfering with the content of an unconditioned heap in the end zone of Athe latter.

While, in Figure 1, the heap-shaping unitl'l is lshown as extending beyond the wheel periphery,

capable of being raised and placed in position above the screen zone and therefore within the wheel radius dimensions, Since the front portion, including the steering handle arrangement swings upwardly when moving to inactive position, there are no interference conditions set up, since the movement is in the direction of the vertical dimension of the foundry.

The brush I4 is of the type disclosed in the companion application, involving a spool-like portion Ilia to whichare `secured a plurality of radially extending flexible bristles I4b, formed of wire or of fibre. However, as indicated in Figure 6, the mounting of the bristles is somewhat changed. `For instance, the bristles are carried by longitudinally extending bars I4c with each bar carrying two rows of the bristles, the rows Vbeing spaced apart, the bars Abeing arranged about the body of the spool. In the form of the companion application, they are held in place by end members which places each bar in contact with the spool body. In the present arrangement the bars are preferably arranged in two series, one series made up of alternate bars contacting with and being secured to the spool body, while the second series formed by the remaining bars are also secured to the spool body but are spaced from the outer periphery of the body. The result is obtained by making each bar slightly overw-idth with respect to the equal angular division of a cross-section of the periphery of the spool body; with the adjacent sidefaces of the vbars extending substantially radial, it is apparent ness; the service is onerous, and can therefore disturb an arrangement of bristle holders-with the present arrangement, should any difficulties in this direction arise, they can be met by further tightening of the bar securing bolts to restore the desired conditions.

As in the companion application, the brush I4 is mounted in bearings I8a carried by members Iii located at opposite ends of the brush zone, said members being carried by the lower ends of vertically-extending threaded rods |813 which pass through frame I3 to points above such frame. Rods I8b provide convenient means for adjusting the vertical height of the brush bearings I8a and therefore permit the brush to not only be properly positioned relative to the floor surface in service position, vbut enable this result to be maintained in presence of wear, lowering of the bearings through the adjustments lowering the brush axis to provide for wear oompensation, suitable adjusting nuts being employed for the purpose.

Rods Ich also adjustably support a plate I9 vabove frame I3, vsaid plate serving to support the power source i and a portion of the structures used for applying the power to the several units as presently explained. If a single power unit is employed, a speed reduction assembly is neces sary, and such speed reduction assembly will be Carried by vplate IQ; if a pair of power units are employed, operative at different speeds, the speed reductionis not needed, and in such case the plate supports both power units. In addition, the plate will support the Vdrive elements which lead to the traction drive unit, any preferred form of drive connections being utilized. For instance, the drive connections for brush I4 may include a pulley 2u driven from th'e power source, and a belt 20a mounted to drive a pulley ZI on the shaft of brush I4; if desired, the drive may be of the sprocket type instead, the latter being indicated, for instance, in the connections between the speedreduction unit 22 and the shaft IIa of the traction drive unit presently referred to, the sprocket chain assemblage (sprocket and chain) being indicated aschain drive unit 23, the power source being indicated as of the single unit type.

The drawings show the use of a single power uni-t, hence the instrumentality is shown as including the speed reduction unit 22. This is shown as driven from the shaft of brush I, itself driven from the power unit, the shaft carrying a pulley 40 mounted at the opposite `end of the brush shaft from pulley 2l, pulley 4b being op# eratively connected with a pulley 4I by belt 41".. with pulley 4I serving to drive the speed reduction unit 22. If the power source utilizes two power units, the drive 4i), 4I and d2 will be omitted, and the sprocket assembly 23 driven direct by the second power unit, the latter, ob viously, operating at greatly reduced speed.

The frame I3 carries depending side plates ita extending downward beyond the ends of brush It", and extending rearward into the screen zone and forward of the brush I4, thus tending to form a semi-enclosed zone within which the brush and screen (and other elements presently described) are located, this arrangement being preferred to tend to retain the dust and dying sand particles, etc., produced by the rapidly rctating brush, from being scattered promiscuous ly. Due to the fact that the conditioning in struinentality swings to and from an inactivo position, the rear ends of the side plates ar-:t shaped to retain the edges inside the maximum radius of the wheels.

The screen I6 is of about one-quarter inch mesh and of a width approaching the distance between the opposite side plates I3a. In its direction of length the `screen is curved with its upper end carried into a spiral contour to pro vide the effect of a basin Ia at the top, the upper end Zone of the screen being supported by brackets I'Sb removably mounted on the upper ends of the rear rods IBI), the screen carrying, at an intermediate point of its height, suitable brackets Ic designed to rest upon flanges of frame I3. The curvature of the screen is such that, when in position, it lies inside the maximum radius of wheels I0 with its lower portion spaced rearwardly of brush I4, the upper portion being curved forwardly so that when the instrumentality is swung to its inactive position without removal of the screen and with the upper zone of the screen then in approximately a vertical plane through the axis of the wheels (Figure 3), the upper zone of the screen would lie materially above the ground level.

In practice, the brush i4, rotating at say lli) R. P. M., it advances along the heap at possibly ten to twenty feet per minute, constantly re moves a thin curved layercorresponding to the curvature of the peripheral path of the brushand throws it rearwardly with Vconsiderable velocity onto the front face of the screengenerally on to the lower halfthe velocity carrying the sand particles over the surface of the screen to a greater or less extent some passing directly through the screen in the lower zone while others may reach higher Zones before passing through the screen mesh. As a result, the material passes through and is discharged from the screen somewhat in the nature of a shower. If theV thrown material includes'lumpy aggregates too large to pass through the screen mesh, the velocity is suiciently high as to cause them to continue over the face of the screen and come to rest in the basin IEa-as is the case with small articles, such Yas nails, etc., used in molding, as well as small castings which may have been left in the unconditioned heap; vthe flexibility of the bristles is such as to cast the latter rearward, and be sufciently yieldable to permit the brush to pass over any heavy casting which may hav remained.

As a result, the brush is constantly removing a curved cross-sectional thin slice from the unconditioned heap and showering it over and.

through the screen, thus providing an admixture effect on the content including the added material, thus ensuring a proper distribution, with the content of the conditioned heap more or less selective due to the sizing effect of the small mesh of the screen. In addition, the undesired content is segregated in the basin a; since the bottom of the basin is of the mesh type, any vibration effect set up through operation will Atend to loosen and segregate sand particles from the basin content and return these to the showering stream to pass with the latter on to and through the screen.

The heap-shaping unit I'l is in the form of a canvas hood-like formation which is also sup-4 in the desired position, especially since the side' edges of the hood are preferably detachably connected to the sides of the frame, thus preventing rearward movement of the hood beyond a desired position. In service, the unit serves to limit the extent to which sand particles can be' projected beyond the screen, and, being exible, will act to shape the heap of conditioned sand as the machine advances.

In service practice, the screen and hood can, and are generally used together. possible that with some heaps the screen may not be required, in which event it is omitted, and the hood alone used--the hood is used at all times during service. While, as above pointed out, the shape and location of the screen is arranged in such manner that it may remain in position during the swinging movements of the instrumentality, it is preferred to remove both hood and screen at the end of the treatment of each heapespecially when both screen and hood are being used; the hoodcan be housed in its inactive position without removal, but screen removal requires also removal of the hood. When the machine has been positioned relative to the succeeding heap, the screenif usedand the hood are restored to position.

The dirigibility ofthe machine under power drive is obtained by the mounting of shaft Ha which supports the drive rolls and which is driven through chain drive 23. Shaft Ila is supported However, it is .wing is being rotated toward the roller.

'by a pair-of shiftable bearings 24 located at opposite sides of the frame. As shown in Figure 5,

each bearing is supported on a casing 25 extending longitudinally of the frame and which carries `a plunger 26 supported by a spring 21 housed by the casing. The top of the casing is slottedto permit the passage of a toe 24a of the bearing, the latter being secured, as by pinning, to the plunger 26; as a result, the spring tends to hold the bearing in its forward position. The forward end of plunger 2B carries a roller 26a, which is adapted to contact a face of a cam 28 mounted on`a rod 29 extending across the front of the machine readily accessible to the operator, the rod carrying an operating handle 29a by which it can be rotated in either direction. This arrangement of bearing assembly is provided on each side of the machine (Figure 2) inthe vicinity of the end zones of shaft l la, and is designed to permit manipulation of shaft position,

.by cam operation, so as to provide for either of Vthree conditions to be present in connection with Vthe cam, the-rocking will not disturb the position `of rollerV 26a from such low position although the The cam 28 on one side of the machine has its high point opposite that of the cam of the opposite side of the machine, with the central low points in alinement on rod 29. The arrangement is such that when the low points of both cams are contacted by the two rollers 26a, the springs 21 will retain the bearingsf24 in their forward position Awith both rolls Il engagingthe wheels Il). When the operator rocks rod 29 in one direction, one of the cams will bring its high point in engagement with its roller 26, thus forcing its plunger rearward to shift its bearing rearward and thus move the adjacent roll Il out of its engagement with Wheel ID; the other cam will be rotated in the same direction, but will not aifect the position of the roller 26a which cooperates with the cam,

' thus leaving the roll l I on that side of the frame still in engagement with its wheel I9, with the result that only the latter wheel is being driven, thus turning the machine with 1the stationary wheel as the axis. If rod 29 is rotated in the opposite direction instead, the same operation will result but the active drive is then with the other wheel. Both cams are provided with an additional face 28d at a similar end of each cam, this face of one cam being laterally alined with the face of the other cam, and each of such faces have a depression 28e adapted to cooperate with the rollers 26a, the bottoms of the depressions being of similar radius from the axis of rod 29; hence, if rod 29 is rotated an additional distance in the direction to bring the depressions into engagement with the rollers 26a, both bearings will be moved rearward a corresponding distance, thus releasing the drive from both wheels Il. As is apparent, the low points 28h and the depressions 28e of a cam are active separately, but the activity of the low points or of the depressions of both cams is concurrent; while the rotating movement of the rod 29 in the direction of rendering the depressions active will cause an earlier disengagement of one roll lI from its wheel IIJ, and thus seemingly tend to swing the machine, the completion of the rod operation is rapid with the result that no material swing will be provided; the same is true when passing from the depressions to the low point position,

The forward portion of the frame also carries a pair of arms 30 which serve to permit the operator to steer the machine.

The frame I3 also carries a cross member IEE) located in advance of brush Id', this member being L-shaped in cross section. The member is designed to carry (l) a plurality of downwardly-extending rods or lingers 3l arranged to simulate the positions of rake teeth, and are designed to detect and advance any large objects,

such as castings, etc., which may be buried 'with 1 The frame also carries at each side a forwardlyv extending arm 33 the forward end of which is bent outwardly at an angle and carries a vertical member 33a, this being located well. in advance of the brush. Members 33a, which are positioned to operate only in connection with the unconditioned portion of the heap, form directing faces which tend to funnel side edge contents `of the heap into the brush zone, thus enabling the use of a shorter brush and less spacingl of wheels I0.

Each side of the frame also carries a footed element Sta at the front, which can ride on the ground surface, if desired, and which will tend to prevent rocking of the instrumentali-ty in the undesired direction; the element also servesas a rest for the instrumentality, if the machine A is stopped withv the instrumentality inservice position.

The frame also carries a pair of vertically extending members 34 at opposite sides and slightly forward of the position of the power the plane of members 34, or at right angles thereto-in either of these positions one of the openings 34h will register with opening 35a, and

a suitable pin inserted into the alined openings will retain the element in a desired position.

This assembly is designed primarily to forni (l) a means for aiding in moving the machine about manually when the instrumentality' *is swung to inactive position-in the latter posi` tion members 34 will extend horizontally, as in Figure S-and (2) to' support the machine stationary in inactive' position, in which case element 36 is swung to itsVv angular position to serve as the support,`

`The frame additionally carries a drag unit 3'I-'an articulated structure which, in service, is located directly in rear of the brush I4, riding on the ground surface. The' drag unit is made up of a drag element 31a having each en d mounted at the outer end of a link 31h which is pivotally supported bythe frame. Pivotally connected with one of the links is a control member 3Ic which extends upwardly in an in; clined direction toward the rear; said member carries apair of notches 31d and 31e designed to cooperate with aV pin:31 f'carrie'd by the frame, member 3'Ic having a suitable handle at its free end to permit manipulation of the member to engage either notch with the pin; notch 31d is of greater length than notch 31e, and is designed to engage the pin when the machine is in service-the lost motion effect thus set up permits the drag 31a. to move swingingly about the pivots of links 312i to meet inequalities f ground surface, etc.; a spring 31g connecting member31c with the frame, tends to retain the drag in'its lower positions but permitting yielding. Notch 31e is designed to support the drag unit in an` inactive position when the instrumen.- tality is to be swung to its inactive position`V drag 31a,- extends beyond the radial limits of wheelsIIl, and must therefore be shifted in order to permit the` instrumentality to swing. The drag 31a may be of any desired configuration, the formishown being that of an inclined plate 31h to which the links are connected, and a pair of downwardly inclined trailing fingers 317' which form the riding surface for the drag.`

The dragunit. has a dual function. In service,

plate 31h forms a directive face for sand beingV thrown by the brush I4, the plate tending to throw the sand inthe direction of length of the screen. However,- the drag additionally serves as a protective agency to prevent accidental Vina-- terial swinging of the conditioning instrumentality. For instance, should one or both wheels I0 meet an obstruction during service and come to rest, the rolls II will. continue to operate; since the drive is of friction type, the stalled wheel or wheels I0 do not continue to rotate, the tendency being for the rolls to tend to rotate the in'- strumentalitytoward its inactive position; such movement is not desired at this time, andl is resisted by the drag; the elongated notch 31d will permit a small movement this direction, and thus afford time for vthe operator to .swing the cams 28 tov bring the depressioris=28c `into action, thus breaking the drive engagement and prevent'- ing any damage to the machine. When member 3`Ic is shiftedto Vdisengage notch 31d and engagep notch 31d, each link 3117 isswung on its pivot to raise the drag and carry it within the majoi radius of the wheels |10, thus permitting the in# strumentality to swing; since the drag unit is a part of the instrumentality, it swings bodily with the instrumentality when the latter is swung"v bef-V tween its service and inactive positions.

One of the important featuresv of the instrumentality assemblage is the fact that thepotv'er source and the brush are located on opposite sides of the axle and generallysymmctrical"tota vplane through the axle. In the service positibnoftheA machine suchplane extends vertically? so that the weightl factor provided by the two unitsis' not disturbing even. though the entire machine is practically poised on the two points' represented by thezoneof the wheel treads in contact with the ground. When the instrumentality is in inactive position, this plane extends substantially horizontal, and the weight of the two units become-of value due to their location relative to the axle, since they not only tend to counterbalance one another, but tend to steady the inachine when the latter is being moved labout with theinstrumentality in inactive position-simulating somewhatthe conditions of a balancing pole. This fact is especially valuable at such time since the machineis then generally being moved manually, and thebalance reduces the need for watchful care in preventing undesired swinging. In addition, this balance condition is of value during the swinging movements, since it tends to reduce the effect of the weight being movedg, making it easier to swing the instrumentality about the axle.

' In foundry practice, the melders generally have their activities on opposite sides of a central or intermediate aisle, each molder generally having an individual aisle or zone in which he fashions his molds, the latter aisles generally extending at approximate right angles to the central aisle. The molding aisles are spaced apart by rows of sand which form the normal sources of sand supply for the molding operations; the rows or heaps of sand generally extend from the central aisle to the vicinity of the sides of the foundry, with an aisle (parallel to the central aisle) left at the ends of the heap adjacent such foundry side', the latter aisles being relatively narrow while the central aisle is of considerable width; the aisles permit the ready movement of the workmen when pouring the metal. After the poured metal has cooled, the asks of the molds are dumped on to the adjacent heap, the castings removed, etc., leaving the heap made up of a mixture of sand unused in making the molds and-the sand which had been used in the completed casting operation; as the latter has been subjected to the casting temperatures, etc., and may contain small castings, nails, etc., used in molding, theresultant heap is unsuitable for the succeeding molding operation without being conditioned. At this time, moisture, new sand anol/ or bond may be addedfto the heap. The machine herein described is designed to provide the conditioning. j I Y fIn service, the machine is positioned relative to the wall end ofthe heap with the arms 30 in advance, and with the wheels in position to straddle the heap, the directing faces 33a being in position to direct sand toward the path ofwadvance oi the brush, the heap generally being ofgreater width than the distance between the fwheels. Assuming the power source to be active, the control lever is operated to bring the low jfaces 28h of the cams in contact with rollersa, causing the wheels l0 to be driven f clockwise in Figure-1, at a speed of from ten to twenty feet per minute, dependent on the power speed and the speed reduction employed. The activity of'the power source causes the brush I4 to be rotated at high. speed-possibly 1000 R. P. M.in a clockwise direction in Figure 1. The faces 33a serve to limit the width of the unconditioned heap in the brush zone, with the result that the sand content is thrown rearwardly ontoV and through the screen, when present, and with the hood limiting the spread of the shower produced; larger size materials and articles Will be 'thrown over the face of the screen into the basin, as pointed out. During. the advance., the

operator 4guides the machine by arms 30, but the power for the advance is from the power source.

When the center aisle end of the heap is reached, the hood is removed or folded up into its position between the brush and axle, the screen is removed if needed, vafter the control lever 29a has been moved to bring depressions 28e into activity with rollers 25a (thus disconnecting the traction wheel drive). The conditioning instrumentality is then swung bodily about the axle-counter-clockwise in Figure l--through approximately placing the instrumentality in the position of Figure 3, excepting Vthat arm 26 normally extends in the plane of arms 34. If the machine is to rest at this point, arm 36`is swung to the position of Figure 3-otherwise, it remains horizontal and offers an additional grasping element for operators during the manual movement. As is apparentV this places the brush, leveling plate, fingers, and drag in positions where the machine can be returned over the next unconditioned heap without materially disturbing the latter. Since shift of control lever 29a has rendered the drive rolls Il inactive, the machine can then be drawn manually over an unconditioned heap to return the machine to the wall end of the heap-the assembly 34, 34a, 35,

and 36 being in advance during this latter movement. The machine is then positioned relative to another unconditioned heap and the operation repeated.

When the machine is not required for service, it remains in the inactive position of Figure 3, arm 36 forming asupport to retain the parts in such position; the machine then occupies its minimum floor space and can be stored in such condition.V When it is desired to again place the machine in service, it is moved manually to the desired unconditioned heap, after which the conditioning instrumentality is swung about the axle to the position of Figure 1-the power source having been made active-the screen land hood placed in position, after which the control lever 29a is operated to move cams 28 to the low points 28bthus starting the advancing movement of the machine.

As is apparent, a number of advantages ar present. Among these is the fact that the ma'- chine can be placed in either service or inactive Aposition without disturbing the relationship of the instrumentality other than the manipulation of the screen and hood, with the movement of the instrumentality readily provided manually although the machine is comparatively heavy;

this ls due to the balanced character of the instrurnentality and the arrangement which permits the instrumentality to swing on and about the axle; this enables the machine to be of a desirable service length, and at the same time e power source and the traction wheels, and which y permits dirigibility during service and yet frees the drive during manual operation.

Another advantage lies in the simplicity of the screen and hood mountings which provide for` efficiency in service, and at the same time permits ready removal and/or manipulation.

Another advantage is found in the brush conv,struction by means of which the structure is retained rigid despite the severe and onerous conditions under which it operates.

Another advantage lies in the fact that the machine can serve as a heap conditioning means regardless of the particular form of molding sand being used; if the latter be of the natural type the complete shower action may not be neededin such case the screen may be omitted from the instrumentality and the hood alone used; if the sand be of the synthetic type, the presence of the screen enables the desired distribution admixture to be obtained. V/hen the screen is omitted, the machine has some of the characteristics of the usual power cutting machines, excepting that the presentmachine provides a superior milling action; because of this condition, the arrangement by which the conditioning instrumentality is movable between an active service position and an inactive position by swinging of the instrumentality on and about the axle, which is a fundamental of the present invention, is considered as falling within the scope of the present invention whether the instrumentality be used with or without the screen, thus including cutting instrumenta-lities.

Other advantages are found in the simplicity of construction and arrangement and the detail advantages pointed out in the above description.

While I have herein pointed out a particular structure and arrangement of parts and various ways of utilizing them, it will be readily under stood that changes or modifications therein may be found desirable or essential in meeting the exigencies of use and the individual desires of the user, and I therefore desire to be understood as reserving the right to make any and all such changes or modifications as may be found desirable or essential in meeting such conditions, insofar as the same may fall within the spirit and scope of the invention as expressed in the accompanying claims, when broadly construed,

I claim:

l. In a machine for conditioning sand for foundry molding service, wherein theunconditioned sand is in heap location and the machine conditions the heap sand within such location, a pair of spaced traction wheels connected by an axle to form a traction unit in which the wheel spacing is sufcient to straddle a heap, and a power-operated conditioning instrumentality supported by the axle and mounted to swing bodily thereon between service and inactive positions and with the swing provided on and about the axle to constitute the axle as the swing axis, said instrumentality including a power source, a

rotatable sand `conditioning unit driven from said source, said source being positioned on the opposite side of the axle from the position of the conditioning unit, the locations and weights of source and unit being such that a plane extending through both and through the axle will extend substantially vertical when the machine is in service and substantially horizontal when the instrumentality is in its inactive position to thereby provide approximate balance of the instrumentality in the vicinity of such plane in either position, a frame carried by the axle for supporting the source and rotating conditioning unit and for forming a semi-enclosed space within which the rotating conditioning unit is located, said frame having a zonal coniiguration in rear of such service position vertical plane such as to present a maximum radial distance from the swing axis within the zone as less than that of a radius of the traction wheels` tor thereby permit bodily 76 swing of the instrumentality between said service and inactive positions, removable means in rear of the conditioningunit for receiving the sand from such unit and for controlling the deposit of the sand in its conditioned heap formation, and controllable means for operably connecting the power source and the traction wheels at will to thereby provide power traction of the machine during service and permit manual traction when the instrumentality is in inactive position.

2. A machine as in claim 1 characterized in that the conditioning unit includes a rotatable brush having `.a plurality of rows of bristle-like elements brought into activity with the unconditioned sand by the bodily advance of the Inachine and operative to throw the sand rearwardly into the depositing zone under comparatively high velocity conditions by the speed of rotation of the brush. y

3. A machine as in claim l characterized in that the conditioning unit includes a rotatable brush having a plurality of bristle-like elements with the brush rotating at high peripheral speed, the instrumentality also carrying a removable screen positioned in rear of the brush and inclined upwardly and rearwardly, said screen being cooperative with the brush in conditioning the sand by the movement of the brush-delivered sand over and through the screen to create a sand-shower" effect in rear of the screen and within the sand depositing zone.

4. A machine as in claim l characterized in that the conditioning unit includes a rotatable brush having a plurality of bristle-like elements with the brush rotating at high peripheral speed, the instrumentality also carrying a removable screen positioned in rear of the brush and inclined upwardly and rearwardly, said screen being cooperative with the brush in conditioning the sand by the movement of the brush-delivered sand over and through the screen to create a sand-shower eifect in rear of the screen and within the sand depositing zone, said screen being located within the radial dimensions of the traction wheels when in service.

5. A machine as in claim` 1 characterized in that the conditioning unit includes a rotatable brush having a plurality of bristlelike elements with the brush rotating at high peripheral speed, the instrumentality also carrying a removable screen positioned in rear of the brush and inclined upwardly and rearwardly, said screen being cooperative with the brush in conditioning the sand by the movement of the brush-delivered sand over and through the screen to create a sand-shower eiIect in rear of the screen and within the sand depositing zone, said screen being curved in its direction of length and having its upper end formed to provide a basin effect for the reception of unscreened material advanced over the screen by brush action, the depth of the curvature facing in the direction of the traction unit axle.

6. A machine as in claim l characterized in that the sand deposit-controlling means is in the form of'a shaped hood of flexible material positioned to receive sand delivered from the rotating conditioning unit and permit its deposit in conditioned sand heap form.

7. A machine as in claim l characterized in that the sand deposit-controlling means is in the form Vof a shaped hood of exible material positioned to receive sand delivered from the rotating conditioning unit and permit its deposit in conditioned sand heap form, said hood being removably supported by the instrumentality and being foldable for housing within the instrumentality when the latter is moving to and in inactive position.

8. A machine as in claim 1 characterized in that the traction control means includes a shaft driven from a power source, a pair of drive rolls carried bythe shaft and positioned individual to the traction wheels, a pair of bearings for the Shaft with each bearing mounted for fore and aft movement with respect to the frame, a yieldable plunger for each bearing, and means for selectively controlling the position and movements oi the plungers individually at will to permit concurrent activity or inactivity of both rolls with the traction wheels or of activity of one roll and inactivity of the other roll with the respective traction wheels to provide machine dirigibility.

9. `A machine as in claim 1 characterized in that the traction control means includes a shaft driven from a power source, a pair of drive rolls carried by the shaft and positioned individual to the traction wheels, a pair of bearings for the shaft with each bearing mounted for fore and aft movement with respect to the frame, a yieldable plunger for each bearing, and means for selectively controlling the position and movements of the plunger individually at will to permit concurrent activity or inactivity of both rolls with the traction wheels or of activity of one roll and inactivity of the other roll with the respective traction wheels to provide machine dirigibility, said selective control means being in the form of a rotatable rod, and a pair of cams earried by the rod and individual to the respective plungers, each cam having a high and a low Y point, with the high point of one cam oppositely related to the high point of the other cam, and with both cams having the low point presented asof zonal length, whereby concurrent location of both cams in low point position will provide concurrent Contact of both rolls with their traction wheels, and rod rotation in either direction to render one of the high points active will move the plunger' to break contact between the roll controlled by such cam and its traction Wheel while maintaining contact of the other roll with its traction wheel, both cams having an additional face carrying a depression with such faces positioned to present the depressions as axially alined, said depression, when active with the respective plungers, serving to concurrently break the contact of both rolls with their traction wheels.

10. A machine as in claim 1 characterized in that the instrumentality includes means for preparing the content of the unconditioned heap for action by the rotary conditioning unit, with themeans carried by the frame in advance of the unit and partaking in the instrumentality swing movements, said means including a pair of wings each inclined outwardly in a forward direction to provide a mouth effect with the inner faces of the wings active to direct edge zones of the unconditioned heap content into the path of travel of the rotating conditioning unit.

1l. A machine as in claim 1 characterized in that the instrumentality includes means for preparing the content of the unconditioned heap for action by the rotary conditioning unit, with the means carried by the frame in advance of the unit and partaking in the instrumentality swing movements, said means including a heap leveling member adjustable vertically for controlling the depth of the heap to be acted uponx relation to produce a rake-like element in ad-V vance of the unit and active to detect the presence of large objects unexposed in the unconditioned heap, said bars being adjustable vertically.

13. A machine as in claim 1 characterized in that the instrumentality includes means for preparing the content of the unconditioned heap for action by the rotary conditioning unit, with the means carried by the frame in advance of the unit and partaking in the instrumentality swing movements, said means including a pair of wings each inclined outwardly in a forward direction to provide la mouth eiect with thev inner faces of the wings active to direct edge zones of the unconditioned heap content into the path of travel of the rotating conditioning u nit, a heap leveling member mounted rearward of said wings and adjustable vertically for controlling the depth of the heap to be acted upon by the rotating conditioning unit, and a service assemblage of vertically-extending bars in spaced relation to produce a rake-like element in rear of the leveling member and in advance of the unit, said element being active to detect the presence of large objects unexposed in the unconditioned heap, said bars being adjustable vertically.

14. AA machine as in claim 1 characterizedk in,

that the instrumentality includes a drag member unit movable between active and inactive positions and having a lost-motion action in its active position, said unit being mounted rearwardly of the rotating conditioning unit and hav.. ing a swingable assemblage which, in active positoin, travels on the floor surface and is yieldable within limits to compensate for inequalities, said unit being operative to prevent undesired swingtive position, said unit being mounted rearwardly of the rotating conditioning unit and having a swingable assemblage which, in active position, travels on the floor surface and is yieldable within limits to compensate for inequalities, said unit Y being operative to prevent undesired swinging of the instrumentality in the direction of the inactive position of the latter and for directing the milled sand from the brush through the screen into a milled heap, said unit ground assemblage being swingingly mounted on a radius such as to project beyond the traction wheel radius when y the assemblage is active, swinging of the assem-v blage to inactive position placing it within the traction wheel radius limits to permit swing of the instrumentality.

16. A machine as in claim 1 characterized iny y that the instrumentality includes a drag member unit movable between active and inactive positions andhaving a lost-motion action in its l active position, said unit being mounted rearwardly of the rotating conditioning unit and having a swingable assemblage which, in active position, travels on the floor surface and is yieldable Within limits to compensate for inequalities, said unit being operative to prevent undesired swinging of the instrumentality in the direction of the inactive position of the latter and for directing the milled sand from the brush through the screen into a milled heap, said drag member unit including a floor-contacting assemblage having an inclined plate positioned in the vicinity of the rotating conditioning unit and active in directing the sand from the latter unit, and trailing feet for supporting the plate, a link connection between the assemblage and the frame, and a spring-supported operating lever connected to the link and having a supporting relation with the frame at tWo spaced points, one of which permits of lost-motion characteristic and is active as a support when the instrumentality is in service position, the other point providing support when the assemblage is swung to inactive position to house the assemblage within the radius limits of the traction wheels.

17. A machine as in claim l characterized in that the instrumentality includes a skeleton frame carried by the instrumentality frame and normally inactive when the machine is in service, said frame being rendered active as a manual draft frame when the instrumentality is moved to its inactive position, said skeleton frame including an arm swingingly mounted on the skeleton frame and movable between a position in general alinement with the frame, to form an additional manual draft element, and a position at right angles thereto with the arm in the latter position serving as a support for the instrumentality in inactive position, the skeleton frame being movable with the instrumentality during the swinging movements of the latter.

HOMER L. BURG.

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