US2258392A

US2258392A - Mulling apparatus

Info

Publication number: US2258392A
Application number: US256741A
Authority: US
Inventors: Walter F Piper
Original assignee: Beardsley & Piper Co
Current assignee: Beardsley & Piper Co
Priority date: 1939-02-16
Filing date: 1939-02-16
Publication date: 1941-10-07
Anticipated expiration: 1958-10-07

Description

Oct. 7, 1941. w. FfPlPER 2,258,392

MULLING APPARATUS Filed Feb. 16, 1959 5 sheets-sheet 1 0C*- 7, 1941 w. F. PIPER. 2,258,392

A MLLING APPARATUS Filed Feb. 16,'I 1939 5 sheets-sheet 2 Oct 7, l941- w. F. PIPER 2,258,392

` MULLING APPARATUS Filed Feb` 16, 1939 5 Sheets-Sheet 3 Oct. 7, 1941. w F. PlPER MULLING APPARATUS Filed Feb. 16, 1939 5 Sheets-Sheet 4 oct. 7, 194,1.

w. F. PIPER 2,258,392

MULLING APPARATUS Filed Feb. 16, 1939 5 Sheets-Sheet 5 Patented oct. 7, 1941 MULLING APPARATUS Walter F. Piper, Oak Park, lll., assigner to The' Beardsley t Piper Company, Chicago, Ill., a

corporation of Illinois Application February 1s, v11139, serial No. 256,741 y 10 Claims.

The present invention relates generally to apparatus for mulling granulare` material. More particularly the invention relates to that type of mulling apparatus which is primarily adapted for mulling or conditioning molding sand in a foundry and comprises (1) a frame structure; (2) a sand retaining receptacle which is mounted for rotation about a horizontal axis and embodies an annular side wall with one end thereof open for the entry and discharge of batches of sand and its other end closed by a circular end wall; (3) an electric motor which is mounted on the structure and operats through the mediumy of a speed reducing unit to rotate the receptacle; (4) a plurality of mulling elements which are disposed adjacent tothe inner face of the side wall and are y adapted during rotation or drive of the receptacle to mull the sand by squeezing it against the side wall; and (5) a scraper whichvis also disposed adjacent to the inner face of the side wall and serves to scrape the sand from the side wall after squeezing thereof bythe mulling elements and to direct the scraped sand inwards so as to mix and serate it and also break up the lumps prior v 25 sideration of the following detailed description.

to .the next engagement of the sand by the elements. t

One object of the invention is t0 provides mulling apparatus of this type which is an improvement upon and is more eiiicient than pret viously designed sand mulling apparatus including that which is disclosed in, and forms the subject matter of, an application for United States Letters Patent llled by me February 13, 1939,

Serial No. 256,096. Y

Another object of the invention is to provide a mulling apparatus of the type-under consideration in which the mulling elements are preferably. two in number and are in the form of narrow freely. rotatable wheels, and positioned in laterally offset relation and one 'ahead of the other so that they operate in connectionwith squeezing oi the 4sand to shift the vsand laterally with a rubbing action whereby any bonding material in the sand is effectively distributed over the grains of sand. t

Another object of the invention is to provide` a sand mulling apparatus of the last mentioned type and character in which the wheel type mulling elements have supporting and control means 1 therefore whereby at the conclusion of a mulling operation they may be shifted bodily away from the side wall 'of the receptacle in order to render them 'ineffective and permit the scraper in connection with successive revolutions of the reeeptacle to break up any .mulling caused lumps (Cl. 83-45) i in the sand immediately prior to discharge of the sand from the receptacle. f Still another objectof the invention is to provide a mulling apparatus of the-aforementioned type which includes plow and defiector means which are of novel design and operate to assist the scraper in breaking up and aerating the sand and also to control the sand so that it is'properly positioned against the receptacle side' wall for l mulling by the wheel type mulling'elements.

A further object ofthe invention is the provision in connection with a sand mulling apparatus of the type and character under consideration of a chute which is mounted or carried bythe supporting structure so that it is shiftable back and forth between a charging position wherein it is adapted to direct the sand to be mulled into the receptacle and av substantially inverted discharge position wherein it operates to catch orreceive the mulled sand from the scraper and direct it out of the receptacle. i i

Other objects of the invention and the various advantages and characteristics of the present mulling apparatus will beapparent from a con- Inthe drawings which accompany and form a" part of this speciication or disclosure and in which like numerals of reference denote corren sponding parts throughout the several views:

Figure l is a front view of a sand mulling ap- 3.53 paratus embodying the invention;

Figure 1* is a detail sectional view of the valve for controlling shift of the mulling elements to and from the receptacle side wall;

.Figure 2 is a rear view illustrating in detailV the design and location of the electric motor and speed reducing unit for drivingthe receptacle; Figure 3 is a vertical transverse sectional view of the speed reducing unit; y 'n Figure 4 is a vertical longitudinal sectional view Voi the apparatus taken on the line 4-`4.of Figure 1 and lshowing the-chutein its charslng'polition;

Figure 5' is a vertical longitudinal view taken on the une s-l or Figure 1 ssd mustreung the chute 5 0 in its discharge' position;

Figure 6 is a sectional view ofthe-elements showing in detail the design. arrangement `and manner of mounting of the mulling elements and alsothe design and manner cf mounting of the scraper for scraping the'sand from the inner face of the receptacle side Wall after treatment or squeezing by the mulling elements;

Figure 7 is a vertical transverse sectional view u taken on the line 1-1 of Figure 4 and illustrating the manner in which the mulling elements, the scraper, and the plow and defiector means operate in connection with mulling or treatment of the sand within the receptacle; and

Figure 8 is a vertical transverse sectional view showing the chute in its discharge position and the manner in which it coacts with the scraper to effect discharge of the mulled sand.

The\apparatuswhich is shown in the drawings constitutes the preferred embodiment of the invention. It is designed primarily for use in a foundry or like establishment in connection with the mulling or conditioning of molding sand and as its main parts comprises a frame structure 9,

a sand holding or retaining receptacle I9, a receptacle driving motor II, apair of mulling elements I2, a scraper I3, and a chute I4. j

' The frame structure 9 is adapted to rest on the oor of the foundry or other establishment in which the apparatus is used and serves as the main supporting medium for the operating parts of the apparatus. It is generally rectangular in contour and comprises a pair of horizontally extending laterally spaced parallel side beams I5, three cross beams I6, I1 and I8 and four legs I9. The side beams are cross-connected and held in laterally spacedrelation by the three cross beams. 'Dhe cross beam I6 extends between and is welded or)` otherwise fixedly secured at its ends to the front ends of the side beams and the cross beam I8 extends between and is welded to the rear ends of the side beams. The cross beam I1 is positioned slightly inwardly ofthe cross beam I8 and extends between and is welded or otherwise xedly secured at its ends to the central portion of the side beams I5. The legs I9 serve to hold the beam formed part of the frame structure 9 in an elevated position with respect to the foundry iioor and are secured to and depend from the ends of the side beams I5. In addition to the side and end beams and the legs, the frame structure 9 comprises a pair of vertically extending laterally spaced parallel standards 20 and 2l. These standards project upwardly from the central portion of the cross` beam I8, as shown in Figure 1. and are cross-'connected at their upper end by a plate 22.

The receptacle III is located over the front portion of the frame structure 9 and is adapted to be charged with a batch of sand to be mulled by way of the chute I4. It:is generally cylindrical in contour or design and embodies an annular side wall 23 and a circular end wall 24. The side Wall is of substantially uniform diameter from one end thereof to the other and'is adapted to have the sand to be mulled squeezed against the inner face thereof by the mulling elements I2. The end wall. 24 is joined to and formed integis laterally offset with respect to the speed reducing unit I9. 'Ilhe latter `comprises a casing 3|, a drive shaft 32, a pinion 33, a gear '34 and a driven shaft 35, and is connected for drive by the motor IIv by Way of a belt and pulley connection 36. The casing 29 is bolted or otherwise flxedly secured to the cross beams I1 and I9 of the frame structure 9 and embodies suitable bearings for the drive and driven

shafts

32 and 35. The drive shaft 32 extends horizontally and in parallel relation with the armature shaft of the electric motor II and carries the pinion 33. Iihe driven shaft 35 is positioned in parallel relation with the drive shaft 32 and is tubular, as shown in Figure 4. The front end of the driven shaft projects an appreciable distance beyond the casing 32 of the unit 29 and extends into and is xedly secured to the hub 25 of the end wall 24 of the receptacle.

The gear 34 meshes with and is driven by the pinion 33, as shown in Figure 3, and is mounted on the central portion of the driven shaft 35. The belt and pulley connection 36 comprises a pair of pulleys 31 and 38, and a series or plurality of endless belts 39. The pulley 31 is xed to the rear end of the armature shaft of the electric motor II and has belt groovesA in the periphery thereof. The pulley 38 is mounted on and fixed to adhere to the side wall 33, yas hereinbefore derally with the ,rear end of the side wall and has in the central portion thereof a hub 25.l The front end of the side wall of the receptacle is provided with an inwardly extending annular flange 29 and this flange, as shown in Figures' 4 to 6 `inclusive, carries a flat ring 21, the inner edge of which defines a circular opening 28 for the entry and discharge of 'the sand. When the receptacle is rotated or driven by the motor II, the sand adheres to the side wall 23 as the result of cen.- trifugal force, and is brought into contact with and squeezed or mulled by the elements I2;

scribed. In order to prevent inadvertent con- Atact with the side wall 23 of the receptacle and resultant injury or damage during drive of the receptacle a substantially semicircular hood40 is provided. This hood extends around the central and upper portions of the receptacle, as shown in Figures 1, 2, 4 and '1, and is secured to .the side beams I5 and the plate 22.l

The two mulling elements I2 are in the form of narrow wheels and are positioned in laterally offset relation'and one ahead of the other, as shown in Figures 5 and 6. They are provided with solid rubber tires 4I andare rotatably mounted on a pair of parallel axles 42. These axles are mounted in sockets 43 in the ends of an arm 44 and proupper end of the arm 48 and carries the pin 46 at its inner end. -It projects through the opening 29 in the ring 21 and is of such length that the arm 45 is disposed in the central portion of the receptacle.A The lever 41 is pivotally supported by way of a bearing bracket 50 and a pintle 5I..

'Ilhe bracket is mounted on the central portion of the cross beam I8 of the frame structure 9 and underlies the, standard 2|.' The pinne is Journaled inthe bracket and is formed integrally with and projects' outwardly from the upper cen-- tral portion of the arm 48. Whenthe arm 43 is swung in a clockwise direction, as viewed in Figure 1, the lever is caused so to swing the arm 44 that the wheel type mulling elementsl I2 are urged or moved toward the side wall 23 of the receptacle I0. Wlhen the arm 43 is swung in the reverse direction, 'that is, counterclockwise as viewed in Figure 1, the lever 41 together with the arm 44 is swung in such manner that the mulling elements I2 are moved 'bodily away from said side wall 23. Swinging of the lever 41'is eiiected by means of a fluid pressure device 52 and a control valve 53. The device 52 underlies one end of the attacca cross beam I6 o1' the frame structure 3 and conf sists of a cylinder 54 and a piston 55. The cylinder is of uniform diameter from one end thereof to the other and is closed at the ends thereof by means of a pair of'head 56 and 51. The head 56 -is pivotally connected by a bolt 53 to one of the legs Ilot the frame structure-,0 so that the device 52 ispermitted to swing in a vertical plane. The piston 55 is. mounted in the cylinder to slide between the two heads'- 53 and 51 and is provided with a stem 59. yThe latter extends-through a packing gland 60 on the head 51 and is pivotally connected at its' outer `end to the lower end of the arm 43 oi the lever 41. When the piston is shifted in the cylinder towards the head 51 the bracket 48 is swung counterclockwise, as viewed in Figure l, and the mulling elements I2 are caused to move away from the receptacle side wall into an inoperativeposition, as hereinbefore pointed out. When the piston 55 is shifted in' the opposite direction, that is, toward the head 56 .of thecylinder 54, the lever 41 is swung or rotated in a clockwise direction and the mulling elements are thus swung toward the receptacle side wall. Shift or reciprocation of the piston in the cylinder is effected bymeans ofcompressed air i under control of the valve 53.'l This valve is mounted on a"bracket 6I on the cross beam I6 and consists of a cylindrical casing and a handle equipped plug 63. The casing supports the plug for rotation about a vertical axis and has a vertically extending annular side wall with four

ports

64, 65, 66 and 61. These ports are positioned or'located 90 apart, as shown in Figure 1*, and are so arranged that the port 61 is Adiametrically oppositethe port 64 and the port gis diametrically opposite the port 65. The

Y Vport 64 is connectedI by a pipe 63 to receive air under pressure from a storage tank or other source-.of supply, and the port 31 is connected to atmosphere by way of a vent-pipe 33.' The port 35,' is connected by a ilexible pipe orhose 1li to the head 53 lat one end of the cylinder 54 and the port 63 is connected by a ilexible pipe or hose 1I to the head 51 at the other end oi the cylinder.

"The p1ug`63 is 'adapted to control the four ports in the side wall oi the valve casing and is limited in any suitable manner to 90 rotation. As shown in Figure 1' two diametrically opposite 90

arcuate notches

12 and 13 are formed in the marginal portion oi the plug.4 When the plug is in one position the notch'12 establishes communication between the pipe 33 and the pipe 1li and the notch 13 establishes communication between the pipe 1I and the vent pipe 33. When the plug is rotated into its other position the notch 12 establishes communication between the pipes 33 and 1l and the notch 13 establishes communication between thepipe 13 and the vent pipe 33.

From the foregoing it is maniiest that when the plug 61 is in itsone position, that is, with the 3 lishing communication between the pipe 1I and the vent pipe 69, air under pressure flows through the head 56 into the cylinder and causes the piston to move towards the head 51 and thus swing the lever 41 in such direction that the mulling elements I2 are swung away from the receptacle Y side wall into their inoperative'position. When the plug 63 is rotated into its other position, that is, the position wherein the notch 12 establishes the lever 41 swings the mulling elements I2 toward the side wall 23 of the receptacle.Y Byl rotating the plug 63 of the control valve 53 the mulling elements may be swung either toward the receptacle side wall and-held under pressure in their operative position or swung away from the receptacle side wall into their inoperative position. When the mulling elements are in their operative position they are under fluid pressure only and hence they arey free to move outwards in the event that they encounter scrap in the sand around.V the side wall of the receptacle. If. desired a pressure regulator (not shown) may be 4connected to the pipe 33 so that the pressure to which the mulling elementsv are subjected while l in their operative position may be controlled or varied. By reason of the fact that the wheel type mulling elements I2 are narrow an effective mulling action is obtained; This is attributable to the fact that the sand duringsqueezing therei portion of the sand which is squeezed or offset laterally by the leading element is directed into the path of the mulling element and is hence again subjected to a mulling action.

The scraper I3 is shaped conformably to the receptacle side wall 23 and is positioned in the upper portion of the receptacle and substantially directlybehind the following or trailing wheel type mulling element I2. It is carried by an'arm 14 which extends through the opening 28 in the ring 21 and is iixed to the central portion of the standard 2I by way of a bracket 15. As shown inFigure '7, the scraper during operation of the apparatus, that is rotation foi the receptacle, operates to scrape thesand from the side wall after it ha's been packed against the latter by the mulling elements I2. The inner face of the scraper is so angled or shaped that is directs the scraped sand inwardly at a slight angle and in an aerated manner. In order to assist thescraper in breaking up the sand and aerating it, the apparatus includes a plow 16 and a' pair of detlectors 11. The plow is located behind the scraper and consists of a pair-of, substantially triangular walls which `are arranged in wedge-type relation and operate to deflect the scraped sand laterally. A vertically extending pipe-like arm 13 serves to support the plow 16 in its operative position and this relation with the aids of rotation of the receptacle and! in addition tosupporting the arm 18 carries the defiectors 11.` The outer end o f the pipe 19 extends through the opening- 28l in the ring 21 positioned at the sides of and beneath'the plow 16 as shown in Figure 4, and are designed and adapted to receive the sand from the plow andf" direct it inwards toward the central portion of 'the side wall and into the path ofthe mulling elements I2. The scraper, plow and deectors coact to aerate and mix the sand after the latter has'been subjected tothe action of the mulling elements. When the mulling elements are shifted into their inoperative position by manipulation of the plug 63 of the control valve 53 the scraper, plow and deiiectors break up any lumps in the sand and thus condition the sand after mulling thereof for immediate use.

.The chute Il constitutes single means for in troducing the sand to be mulled into the receptacle and for discharging the mulled sand from the'receptacle via the opening 28. It commises an elongated curved bottom 8| and a pair of sides 82.' and is pivoted on a' rod 83 to swing about a horizontal axis. The sides 82 `of the chute are positioned in laterally spaced relation and have aligned pivot holes 84 for the rod 83. The rod, as shown in Figure -l, extends between register with the bracket il and have the pin I2 pass therethrough into the bracket 88 for locking purposes. f

In order to eliminate dust during use or operation of the apparatus a. duct 83 is provided.

This duct is connected. to the outer end of the hollow driven shaft 35 and is provided with a fan 94 for creating a suction therein. Therfan is so arranged that the suction within the duct operates to draw any Adust or sand in suspension from the interionof the receptacle through the driven shaft 35; The discharge. end of the duct is'adaptedto be connected to a dust collector or like device (not shown) When it is desired to operate the apparatus. the motor I0 is rst started so as to eiect rota@ tion `or drive of the cylindrical cylinder II. Thereafter the plug 53 of the control valve 53 is manipulated so as to cause by the control of compressed air movement of the piston 55 toward the head 55 of the iluid pressure device 52.

As heretofore pointed out, such movement of 'th'e piston operates through the medium of the lever 41 to swing' the wheel type mulling elements I2 toward the side walls of the receptacle.

` After the aforesaid manipulation of the plug of and is secured at its ends to the upper ends of the standards 420 and 2'I. The chute is so designed and pivoted that it may be swung back and forth between a charging position wherein it is outside of the receptacle and the bottom/8| is downwardly and inwardly inclined, as shown in Figure 4, and a discharge position wherein it is disposed for the most part within the receptacle I0 and the bottom is downwardly and outwardly inclined, as shown in Figure 5. When the chute I4 is in its charging position and sand to be mulled is introduced into it, the sand to be mulled is directed into the bottom of the receptacle. When the chute Il is swung into its discharge position, as shown in VFigures 5 and 8,

the inner portions of the sides 82 are positioned behind and beneath the scraper I8 and operate to catch the scraped sand and direct it onto the bottom BI which because of its incline directs or discharges the sand from the receptacle. 'I'he shaping of the inner ends or portions of the side walls 82 is such that'when the chute is in its discharge position they catch all of the sand from the scraper and hence discharge of the mulled sandA is effected during one revolution of the receptacle. By having a single chute serve as the charging and discharge meansI the apparatus as a whole 'is simpliiled.A A fixed U-shaped apron 85 is connected by brackets 88 to the central portion of the cross beam I 6 and serves as a continuation of the chute when the latter is in its charging position and prevents any spill-V tured lugs 90 and 9| on one side of the chute,A

and Za head equipped pin 92. The lug 9| is so arranged that when the chute is in its charging position it overlies or registers with the bracket 89 and permits the 'pin 92 to pass therethrough I the control valve 58 unit are such that the receptacle is driven at a.

into the aperture of the bracket and` lock theI chute in place. The lug 9| is located at the outer end ot the chute and is adapted when the chute is in its charging 'position to overlie or the control valve the sand to be mulled is introduced into the receptacle by delivering it to the chute Il while the latter is held or locked into its charging position. After the san'd is delivered into the receptacle it comes in contact with and revolves with the side wall 23. As the sand passes the wheel type mulling elements I2, it is squeezed against the side wall by the elements and the desired mullingis effected. If bonding material is mixed with the sand it is uniformly distributed over thev grains of'sand as the result of the squeezing and mulling action of the mull ing elements- I2. After the sand travels past the trailing mulling element I2 iti encounters the scraper I3 and is scraped' from the side wall and directed inwardly towards the plow 16, as hereinbefore described. After engaging or encountering the plow the sand strikes against the de.

, iiectors 'I1 and is deflected by the latter. toward the central portion of the receptacle side wall wherein it is lproperly positioned. for further mulling by the elements I2. As a result of the squeezing of the sand by the elements and the mixing and aeration of the sand by the scraper, plow, and deiiectors, thedesired or proper conditioning of the sand is obtained.A At the conclusion of the mulling operation the plug 58 of is turned so as to cause the fluid pressure device .52 to swing the mulling elements I2 into their inoperative position. While the elements are in their inoperative position, the receptacle is permitted to rotate several times so that the scraper, plow and deflectors operate to break up any lumps. After breaking up of all the lumps the chute is released by removing the pin 82 and is swung inwardly into its discharge position. As-soon as `the chute reaches such position it is locked in place by the pin and serves during but a-single revolution of thereceptacle to discharge all of the mulled sand. During operation ofthe apparatus the fan equipped duct 38 operates to evacuate any dust or sand in suspension from the receptacle. The motor and speed reducing suilicient speed to cause centrifugal action or foro ehto hold the sand in contact and for rotation withf the receptacle side wali 28. 'IL forexample, the receptacle has a diameter of four feet it is driven at forty revolutions per minute or more in order to effect the desired adherence of the sand with the receptacle side Wall.

The hereindescribed muiling apparatus consists of but a small number of parts and hence may be manufactured at a low and reasonable cost. It is extremely eiiicient and effective asl far as the mulling of sand is concerned because of the arrangement and design of the narrow sand type mulling elements I2. By reason of the fact that the elements are mounted or supported so that they may be swung inwardly away from the side wall of the receptacle into an inoperative position it is possible at the conclusion of `a mulling operation to utilize the scraper and associated plow and deflector means for breaking up any lumps in the sand prior to discharge of the sand from the receptacle. By having the receptacle rotate on a horizontal axis and employing the chute Il for introducing the sand into the receptacle and discharging the mulled sand therefrom, the apparatus affords accessibility to its parts and is extremely Asimple in design.

Whereas the apparatus has been described as being primarily for use in a foundry in conneca pair of deectors positioned behind and outtion with mulling'of molding sand, it is to ,be

understood that it may be used for conditioning other materials. It is also to be understood that the invention is not to be restricted to the details set forth, since these may be modified within the scope of the appended claims, without departing from the spirit and scope of the invention.

lHaving thus described the invention, what I claim as new and desire to secure by Letters Patent is:

1. A mulling apparatus comprising in combination a .frame structure, a receptacle for the material to be mulled mounted to-rotate about the center thereof and embodying an annular side wall, means carried by the frame structure for rotatingvsaid receptacle, a mulling element disposed in the receptacle and adjacent the side wall 'and having frame-structure-carried supporting means-therefor whereby it is movable toward said side wall into an operative position wherein it serves during rotation of the recep-y tacle to muli the material by'squeezing it against the side wall, and away from said side wall. into an inoperative position wherein it effects no mulling of the material. and iiuid pressure actuated means fr shifting the elementinto either its operative or inoperative position embodying a valve type control device with a single movable part, and adapted upon movement of the part into one position to shift the element into its operative position and upon movement of the part into anotherv position to shift the element into its said inoperative position.

2.l A mulling apparatus comprising in combination a frame structure, a receptacle for the material to be mulled mounted on the frame structure to rotate on a substantially horizontal axis andl embodying an annular side wall concentrically arranged with respect to the axis and having means associated therewith for entry and discharge cf the'material, means on the frame structure for rotating the receptacle, a mulling ele-` ment positioned inthe receptacle and adjacent the side wall and adaptedduring rotation of the receptacle to muli the material by squeezing it against said side wall, a scraper disposed in the lreceptacle behind the element and adaptedto scrape and move inwardly the material from the side wall after squeezing thereof by the element,

wardly of the scraper and arranged and designed to divert the scraped material back on to the side wall and into the path of the mulling element.-

3. A mulling apparatus 4comprising in combination a frame structure, a receptacle for the material to be mulled mounted to rotate on a substantially horizontal axis and embodying an annular side wall concentrically arranged with re spect to the axis and having vone end thereof open, means for rotating the receptacle, a. mulling element positioned in the receptacle` and adjacent the side wall and adapted during rotation of the receptacle to muil the material by squeezing it against said side wall, a scraper in the receptacle positioned behind theV element and adapted to scrape the mulled material and direct it inwards'from the side wall, vand a chute mov-l ably supported `on the frame structure so that it is shiftable back and forth between a charging position where it is exteriorly positioned with respect to the receptacle and serves'tc direct the material to be mulled into the receptacle via thel open end and a discharge position wherein it is 'receptacle and adjacent the side wall and adapted during rotation of the receptacle to mull `the material by squeezing it against said'side wall,

a scraper' in the upper portion of the receptacle carried by the frame structure and arranged to scrape the mulled material from the side ,wall and deflect it downwards, and a chute pivotally supported on the frame structure so that it is shiftable back and forth between an inclined. charging position wherein it is exteriorly disposed with respect to the receptacle and serves to direct the material to be mulled into kthe receptacle via the open end, and a reversely inclined discharge position wherein it is disposed substantially within the receptacle and operates to receive the scraped material from the scraper and direct it outwards through said open end.

5. A mulling apparatus comprising in combination a frame structure, a receptacle for the materia1 to be mulled, mounted on the structure to rotate about the center thereof and embodying mounted von the ends ofthe arms and extending in substantially parallel relation with said side wall, comparatively n arrow wheel type mulling elements rotatably mounted on thev axles and adapted during rotation of the receptacle to muil thematerial by squeezing it against the sidewall, l

and means for quickly' and readily shifting the arm together with vthe mulling elements toward or away from said side wall. r 6. 'A mulling apparatus comprising a receptacle for the material to be mulled mounted to rotate about the axis thereof and embodying an annular side wall together with means forming an opening for entry of the material, means for rotating the receptacle, an arm in said receptacle and adjacent the side wall having supporting means therefor `whereby it is movable bodily to and from said side wall and embodying axles at its ends extending one in one' direction and the other in the opposite direction and arranged so that they are parallel to the axis of said receptacle, a pair of'narrow wheel type mulling elements mounted on the axles in laterally oiset relation and adapted during rotation of the receptacle to squeeze the material against the receptacle side wall in order to effect mulling thereof, and means associatedV with the supporting means for urging the arm towards the receptacle side wall and' thus rendering the elements opervative.

' 7. A mulling apparatus comprising a frame structure, a. receptacle for the material to be mulled mounted to rotate on a substantially horizontal axis and embodying an annular side wall concentrically arranged with respect to said axis and having one end thereof open, means on the frame structure for rotating the receptacle, an arm in the receptacle and adjacent said side wall, having frame-structure-supported mounting means therefor whereby it is movable bodily to Aand from said side wall and embodying at its ends a pair of laterally oil'set axles extending one in one direction and one in the opposite direction and substantially parallel with said receptacle side wall, a pair of wheel type mulling elements mounted rotatably on and held in laterally offset relation by the axles and adapted during rotation of the receptacle bysaid means to muil the material by` squeezing it against the side Wall, and means supported on said frame structure and associated with the -mounting means for urging said arm towards the receptacle side wall and thus rendering the elements operative.

8. A mulling apparatus comprising a receptacle for the material to be mulled embodying an annular side wall and having means forming anv opening for entry of the material, an arm inthe receptacle and adjacent the side wall, means for supporting the arm so that it is movable bodily to and from the side wall, embodying as part thereof a central pivot for the `arm whereby said arm is free to tilt relatively to the side wall. a pair of rotary wheel type mulling elements mounted on axles at the ends of the arm and parallel to the axis of thereceptacle, and adapted to effect mulling of the materialby squeezing it against the side wall, and means associated with the supporting means for urging the arm toward the receptacle side wall and thus rendering operative the mulling elements.

9. A mulling apparatus comprising a frame structure, a receptacle for the material to bev mulled mounted to vrotate about the center thereof and embodying an annular sidewall with one end thereof open for-entry of the material and its other end closed, means on the frame structure for rotating the receptacle, an elongated arm in the receptacle and adjacent the side wall vcarried by the frame structure so that it is movable bodily to and from said side wall and having a pivot at the central vportion thereof so that the ends thereof are free to swing to and from said side wall, axles on the ends of the arm projecting in opposite directions and in substantially parallel relation with the side wall, comparatively narrow wheel type mulling elements rotatably mounted on the axles in laterally oiset relation and adapted during rotation of the receptacle to muil the material by squeezing it v against the side wall, and power means for urging the arm toward the receptacle side wall and thus rendering operative the mullingl elements.

v10. A mulling apparatus comprising in combination a receptacle for the material to 'be mulled embodying a continuous side wall and an end Wall and having means forming an opening for the entry of the material, a freely rotatable mulling element in the receptacle and adjacent one wall thereof mounted to move towards said one Wall into an operative position wherein it serves to muli lthe material by squeezing it against saidv one wall and away from said one wall into an inoperative position wherein it eiiects no mulli'ng of the material, and iiuid pressure actuated means for shifting the element into and out of its inoperative position, embodying a valve type control device therefor with a single movable part and adapted upon shift of said'part into oneposition to shift said element into its operative position and upon shift or movement of the part into another position to retract the element or shift it into its inoperative position.'

WALTER F. PIPER.