US2302138A

US2302138A - Juice extractor

Info

Publication number: US2302138A
Application number: US339754A
Authority: US
Inventors: Daniel T Nicholson
Original assignee: Individual
Current assignee: Individual
Priority date: 1940-06-10
Filing date: 1940-06-10
Publication date: 1942-11-17
Anticipated expiration: 1959-11-17

Description

Nov. 17, 1942. D. T. mcHoLsoN JUICE EXTRACTOR Filed June 10, 1940 Patented Nov. 17, 1942 UNITED STATES PATENT OFFICE .mica Ex'raacron Daniel 'r. Nioholson, Los Angeles, Calif, Applioaiion June 1o, 1940, serial Nt. 339,154

22 claims. (ci. 14s-1s) This invention relates to machines for extracting juices from fruit and vegetables. More speciilcally, it concerns a machine having a mode of operation that involves a departure from the usual previous practice of presenting material to a cutter with the material held in a substantially fixed position, but pressed forward against the cutter. My machine, on the contrary, is especially constructed to prevent such a fixed presentation of the material during the commuting or.pulping operation, and operates to attain an opposite eifect and promote to the highest degree, practicable mobility of the material during the comminuating process. This avoids overloading the machine and consequent high power consumption accompanied by inferior results.

One of the objects of my invention is to provide a machine for immediately producing a relatively fine pulp from pieces of fruit or vegetables, and to extract the juices therefrom.

A principal object of the invention is to provide a machine, which in operation will continually turn over the pieces or chunks of material so that they will successively present different portions of their periphery to the cutters.

A further, object of the invention is to provide a machine for accomplishing the above objects with the expenditure of a minimum amount of power.- t

A further object of the invention is to provide a construction for the machine, that will enable it to develop a partial vacuum in the charging chamber or feed hopper of the machine, and at the comminuting zone, to increase the exuding of the juices from the pieces being reduced.

In its preferred construction, the machine includes a comminutorelement rotating at a high speed and surrounded by a centrifugal screen that separates the pulp from the juices. One

of the objects of my invention is to provide a 40 readily removable pulp collector that receives the pulp thatpasse's over the screen; also to construct the pulp collector so that when secured in position it will seal oir the juice chamber from 45 the outer space where the pulp is collected.

A further object of the invention is to provide a centrifugal comminutor element having features of construction enabling it to operate effrom a charge fed to it, and at the same time to protect it from being choked or retarded by -the pressure of the charge against it. This is highly advantageous as it enables the comminutor to be driven directly at a one to one ratio 55 from an electric motor, and avoids any necessity for employing reduction gearing in the drive;

Further objects of the invention will appear hereinafter. l

The invention consists in the novel parts and combination of parts to be described hereinafter,

all of which contribute to produce an eilicierlt I juice extractor. l

A preferred embodiment of the invention is described in the following specification, while the broad scope of the invention is pointed out in the appended claims. y

In the drawing: V

lFig. 1 is a side elevation of a small`domestic machine embodying my invention.

Fig. 2 is a vertical section through the machine illustrated in Fig. 1, but upon an enlarged scale, and further illustrating the preferred details of the invention. f

Fig. 3 is a horizontal section upon an enlarged scale passing through the comminutor element orpulper.

Fig. 4 is a side elevation and partial section with the middle portion broken away, of the comminutor element or pulper illustrated in Figs. 2 and 3.

Fig. 5 is a side elevation and -partial section illustrating upon a small scale a form of `guide or basket that may be used when the juices are not to be separated from the pulp.

Fig. 6 isA a fragmentary view, and is a vertical section taken at the upper end, of the motor shaft, and showing the driving connection between the shaft and the bottom of the-screen element.

Fig. 7 is a fragmentary View and is a vertical section taken through the edge ofthe comminutor in a, modiiied form that I may employ.

Fig. 8 is a side elevation .upon a small scale,

illustrating a disc-form of comminutor that may` be used if desired, with other features of the invention.

The drawing illustrates a machine embodying my invention. This machine is of a small, domestic type for household use, or in resturants. This type of machine is intended to operate upon pieces or chunks of fruit or vegetables previously chopped up more or less to sizes that will be suflicient'ly mobile individually under the influfectively ata high speed, to produce a fine pulp 50 ence of the centrifugal comminutor or pulper.

In practicing the invention I provide a casing I presenting a oor or bottom 2 above which the centrifugal'pulper or comminutor 3 is located.

This comminutor 3 may be of disc form such as the disc form pulper 3a shown'in Fig. 8, or it may have the rounded bowl form of the pulper 3b illustrated in Fig.`7, in which the bottom is merged by an easy curve into the side wall; or of the conical form shown in Fig. 5.

However, I prefer to use a comminutor. or pulper 3 of cup form, that is to say, it is hollow, so that it is open above, and has a circumferential wall 4 and a bottom 5.

The pulper is driven at a high rotary speed by an electric motor 6 below it, the shaft 6a of which projects up through the floor 2, and which may be provided with a head 1 to removably support and rotate the pulper.

'I'he inner face of the wall 4 is given a form thatA will exert a force on the contacting chunks.

of the charge, to turn the same over and at the same time to take minute bites from their periphery. For this purpose I form the wall 4 with a, plurality of slots 8 extending through the same with the following edges 9 of the slots offset inwardly from the face of the wall 4. And I also form corrugations on the face of the wall by means of a screw thread I0. tation as indicated by the arrow in Fig. 3, this thread would be a right-hand thread, so that when a chunk of fruit cornes against the face of the Wall, the peaks of the thread "kick or wipe the outer side of the chunk upwardly, thereby causing the same to turn over, and as the oiset cutters 9 pass, they take minute bites out of the chunks. In this connection it is evident that each upwardly extending cutter 9 (extending along the edge of its slot 8) is composed of a plurality of minute teeth formed by the intersection of the slots with the screw thread, and the scroll thread on the disc of the comminutor. These minutel teeth reduce the flesh of the fruit or vegetable to a ne pulp which passes out through the slots against the inner face of a foraminous member or mesh screen IIA that retains the pulp, but passes the juice outwardly through it.

The screen Il is clampedbn the driving head 'l so as to rotate in unison with the pulper 3.

The slots 8 incline upwardly in a rearward direction with respect to the direction of rotation. Furthermore, the faces of the slots incline rearwardly with respect to a radial line, that is, rearwardly also with respect to the direction of rotation. This gives them a desired pneumatic effect on the air withinthe casing, and augments a partial vacuum as will be described more in detail hereinafter.

In order to agitate the charge and increase the lrolling effect that the thread IIJ has on the chunks or dies of cut up fruit or vegetables, I provide bailles so disposed that they cooperate to .lift the chunks and let them fall back toward the bottom of the pulper.

These bailles are preferably in the form of baille posts I3a that project down into the pulper adjacent to but not touching the inner face of the wall 4. They preferably incline upwardly and forwardly with respect to the direction of rotation so that when a chunk, die, or pellet strikes the side of a baille post, the upward inclination of this face cooperates with the pulper to lift the chunk at its outer side. The baille posts are preferably carried at the lower edge of an outlet I2 of reduced diameter that forms the lower end of the bowl or hopper i3 for the charge of fruit.

In order to prevent any tendency of the charge to become choked in the pulper, and to reduce For clockwise rothe resistance in driving the pulper, I prefer to provide a central shelf or baille I4 within the pulper, that is illustrated as of mushroom form with a substantially conical upper face that exerts a certain supporting effect, and down which the charge gravitates, and the'rotation of which throws the chunks out by centrifugal force. This center baille may be said'to divide the pulper into an upper and a lower chamber. The width of the space around its edge determines the size fl the pieces that can pass down. It is threaded below to form a socket enabling it to screw down on the upper end of the threaded shank 6b that is formed integrally on the upper end of the motor shaft 6a. This baille I4 is more specifically intended for large or commercial sizes of my machine in which any desired number may be placed one above another.

In order to relieve the pulper 3 and the baffley I4 of much of the weight of the column of material on it, I prefer to employ a. relatively large baille I rotatably hung at its center from a support I6 formed within the hopper in a position to hold the baille about in the throat above the reduced outlet I2 This baille is adjustable vertically on a screw spindle I5a and has downwardly projecting fingers I5b to engage the charge. The vertical adjustment on screw spin-s dle I5a permits feed control of various materials to the pulper at a rate suited to its capacity.

The casing I is illustrated with an outer skeleton frame I6 of relatively large diameter, to form a space to receive an annular pulp holder I1 that has an inner wall or apron I'Iaagainst which the juices splatter, and which guides them down to an annular collecting gutter AI8 that leads the juices to a delivery spout I9at one side. Around the outer edge of the gutter I8 an encircling seat is formed. The pulp holder is formed with an annular shoulder 2l to t down tight upon this seat, a second seat 22 beso that when clamped in place the shoulder ZI will maintain itself tight on the seat 20. This pulp holder is so constructed as to render it readily removable and 'replaceable for cleansing without disturbing the pulper or its surrounding screen.

The bottom 5 of the pulper is also preferably provided'with outwardly extending slots 26 cut through the bottom; and the upper side of the bottom is preferably formed with corrugations by forming a circumferential scroll thread 21. If desired, this thread may consist of a succession of circular ridges or peaks separated by valleys or grooves, but this thread is preferably of spiral form and extending around the axis of rotation of the bottom in the opposite direction in which the pulper is rotated. Onthis account, the peaks of this thread constantly urge the material resting on the bottom, in an outward direction and against the inner face of the wall 4.

The outer ends of these slots if desired, may communicate with some of the slots 8 in the side wall 4 of the pulper, but'if desired, I may provided an increased number of slots 8 as compared with the slots 26.

In Fig. 6 I illustrate the driving connectionat the driving head 1. This driving head 1 m ,j the form of a nut that screws down onto a shouly der on the upper end of the motor shaft 6a, and this nut or driving head 1 is provided on its upper side with one or more `driving pins 23 that will nt into socketsy such as the sockets 29 formed circumterentlally in the lower face of a boss 30 formed on the under side of the bottom of the separator Il. By having a considerable number of these sockets 29, the placing .of the separator screen back in driving position is facilitated. The bottom of the lpulper has a central hub 3| which screws down into position over the,

'threaded shank bialready described and so clamps separator II securely on threaded shank 6b. To dismount this engagement it .is merely necessary to hold separator with onel hand while unscrewing the pulper with the other.

The bowl I3 is provided with a cover 32 that is. preferablyof transparent materiaLand this cover should seat with a substantially air-tight connection on the upper ilange 33 of the bowl. If desired, a Asoit gasket 34 may be used at this ing. The foot of this pedestal may be provided with a plurality of soft rubber feet 39 to rest upon -a horizontal surface.

The mode of operation of the machine will now be described. The more or less chopped up fruit or vegetables, are placed in the bowl I3 and descend by gravity through the throat of the bowl and the small pieces or pulped particles pass out point tosinsuresubstantial air-tightness. This is done in order to enable a. partial vacuum to be developed in the interior of the bowl I3. This partial vacuum is increased by reason of the fact that the rearwardly inclining slots 8 (with respect to the radius anddirectional rotation) 4 act as fan blades to withdraw air from the interior ofthe bowl i3. K

The pulper 3 which rotates at a relatively high speed. acts as a suction fan withdrawing the air from the interior of the bowl. This action is enhanced by reason of the fact that the lower end of the outlet l2 is fitted closely adjacent to the top part of the pulper wall. Creating a partial vacuum in this way, is highly conducive to an eiilcient extraction of the juices, because the juiceswithin the flesh of the fruit or vegetables are, of course, under atmospheric pressure, and when this is relieved, the juices exude with freedom and coolness.

In Fig. 7 I- illustrate another form of crosssection that may be used for the pulper, but in which the side wall 35 is more or less conical or flaring, and merges through a curve intcthe bottom 36. If the typeof cross-section shown in Fig. yl for the pulper is used, little or no inoline would be necessary for the baille posts that extend down along the inner `face of the side wall of the pulper; and in fact, with the wall having the form illustrated in Fig. `'7, it might be necessary to slant the baille posts in the other direction to overcome too great a tendency of the'charge to move up to the-edge of the pe. ripheral wall 35. 0f course,'if the type of wall illustrated in Fig. 'I or Fig. 8 is employed, the baie posts would be made to iit closely to the contour of the inner face of the Wall or floor of-such pulper. Whatever be the formof crosssection for the pulper, the baille posts Will conform to the same and extend close to the toothed surface of the pulper.

Ii it should be desired to collect the juice and pulp unseparated. this can be accomplished by removing the separator screen Il and substituting for it a solid Walled conical guide or receiver such as illustrated in Fig. 5. With this part in place the pulp anc juice travels up the conical Wall and over its upper edge into the pulp lholder l1.

The electric motor 6 can be driven through the agency of an electric cord 31 that may pass through an inlet opening in the side wall of the pedestal 38 that forms the lower part of the casthrough the slots 8 and l'and against the wall of the centrifugal screen Il. The screen operates to retain the pulp and permit the juices to pass through. Thesejuices splatter against the inner apron wall lla. of the pulp holder, and the juices rundown this wall into the collecting gutter i8 that conducts the juices around to the spout i3.

As the pulp accumulates in the screen, it

`travels up toward the upper edge of the screen and passes over this edge and over the upper edge ofthe apron ila and falls down into the annular space of the pulp holder, as indicated by the ar rows in Fig. 2,. From time to time the cover 24 of the casing can be removed, the pulp holder taken out of place, and the collected pulp dumped out, the pulp holder replaced .and operation con tinued.

The specific action of the thread lil in causing an upward rotation of the outer sides of the chunks oi-` material in contact with the wall 4, has been described in detail Within this specication. Suice it to say at this point, that my mechanism affords means for effecting a constant turning over or rotation of the chunks of material while small bites are taken from the same by the teeth of 'the cutters. This action results in reducing the chunks of fruit or vegetables to a more or less spherical form as the operation progresses. ln this Way even if the chunks of material are irregular when put in place, the machine operrates of course, to bite ofi projecting edges more rapidly than flat faces, and in this way the machine itself soon operates to reduce the chunks of material to more or less pellet form, and this of course, is favorable 'to their'rotation as the machine performs this rotating function during its operation.

Ii desired, the pulp holder il may be formed of transparent plastic material or glass, to enable the operator of the machine to observe Whether it is full of pulp.

lclogging effect, heat generation, congestion of the charge in the pulper and resultant discoloration of juices. l

The material being acted upon by the pulper is constantly impelled tomotion, causing change of its position by the screw actionrof the threads on the interior of the pulper. This insures thorough comminution or pulping as opposed to slicing.

The presentation of the material to the moving cutters and a constant; change of position for the chunks being reduced, has the following advantages: It avoids congestion or clogging of the material, and minimizes friction so that the machine can operate uniformly practically at its maximum speed, thus assuring maximum erliciency for the comminutor and separator elements. It also prevents clogging or choking of the charge, thereby avoiding the generation of heat and preventing the raising of the temperature with resultant discoloration of the juices.

The general construction and assembly of the machine is advantageous because the pulp chamber can be readily removed and replaced without disturbing the pulper or its associated parts upon the motor shaft. Furthermore, no tool is required to assemble or take apart for cleansing the elements employed in the machine.

Many other embodiments of the invention may be resorted to without departing from the spirit of the invention. i

What I claim is:

i. In a centrifugal machine for pulping vegetables or fruit and extracting the juices thereof, the combination of a hollow rotary comminutor element open above and having a circumferential 'wall with circumferentially extending corrugations on its inner face with slots in the wall exganarse tending across the corrugations so as to form the wall extending across theicorrugations so as to form comminutor teeth at said slots, means for guiding the charge of material down into the comminutor from above, a plurality of rela tively fixed bailies lying adjacent to the inner face of the said wall, and a rotary screen having an upwardly aring screen wall permitting the juices to pass through, and operating to advance the pulp upwardly toward the upper edge of the screen, and an annular pulp basin for collecting the pulp passing up and over said screen wall.

3. In acentrifugal machine for pulping vegetables or fruit and vextracting the juices thereof, the` combinationof a hollow rotary comminutor element open above and having a circumferential wall with circumferentially extending corrugationson its inner face with slots in the wall extending across the corrugations so as to .form comminutor teeth at said slots, means for guiding the charge of material down into the comminutor from above, a plurality of relatively fixed baiiles lying adjacent to the inner face of the side wall,- and a rotary screen having an upwardly ilaring screen wall permitting the juices to pass through, and operating to advance the pulp upwardly toward the upperedge of the screen, and a centrally disposed baffle Within the comminutor for dividing the comminutor chamber and forming an annular throat through which the charge feeds downwardly.

4. In a centrifugal machine for pulping vegetables or fruit and extracting the juices thereof,

the 'combination of 'a hollow rotary comminutor element open above and having a circumferential wall with circumferentially extending corrugations on its inner face with slots in the wall extending across the corrugations so as to form comminuator teeth at said slots, means for guiding the-charge of material down into the comminutor from above, a plurality of relatively A ixed baies lying adjacent to the inner face of the side wall, and a rotary screen surrounding the said wall for retaining the pulp and permitting the juices to pass out, said corrugations being of substantially V shape in cross-section and having pitch so related tothe direction of rotation a's to urge. upwardly chunks of material in contact with the same,I

5. In a centrifugal machine for pulping vegetables or fruit and extracting the juices thereof, the combination of a hollow rotary comminutor element open above and having a circumferential wall with circumferentially extending corrugations on its inner face with slots in the wall extending across the corrugations so as to form comminutor teeth at said slots, means for guidingthe charge or" material down into the comminutor from above, a plurality of relatively fixed.

baiiies lying adjacent to the inner face of the said wall, and a rotary screen surrounding the said wall for retaining the pulp and permitting the juices to pass out, said baflles being in the form of downwardly projecting bars inclined laterally in a direction to cooperate with the direction of rotation to urge upwardly, portions of the charge impelled into contact therewith v air from the interior of said hopper when the comminutor is rotating at a high speed, and a removable cover for the hopper making a substantially air-tight connection with the hopper,

cooperating with the rotating comminutor to develop a lpartial vacuum Within the hopper to augment the extraction 'of the juices as the cutting teeth function.

7. In a centrifugal machine for pulping vegetables or fruit, and extracting their juices, the combination of a casinga cup-form centrifugal comminutor having a\bottom and a circumferential Wall extending upwardly from the bottom and having cutting teeth on the upper face of the bottom, a charging hopper with an outlet at its lower end delivering the charge into the interior of the comminutor, said circumferential Y wall having a plurality of slots through the same rinclining rearwardly and outwardly with respect to the direction of rotation so as to Withdraw air from the interior of the delivery neck when the comminutor is rotating at a high speed, a removable cover for the hopper, making a substantially air-tight connection with the hopper cooperating with the rotating comminutor to develop a partial vacuum within the hopper to augment the extraction of the juices as the cutting teeth function, a pulp screen having a cir- :,soaisc cumierential wall surrounding the comminutor for retaining the pulp and permitting the juices to pass through, said casing having a juice gut-z edge of the screen and over which the pulp passes into the pulp catcher, said pulp catcher having an annular shoulder seating-tightly on said encircling seat, and having an outer wall, and-,a

cover for the casing in contact with the said outer wall of the pulp catcher, with means for tightening the same down so asto press the pulp catcher down tightly on said-seat. y

8. In a centrifugal machine for pulping vegetablesI or fruit, and extracting their juices, the combination of a casing, a cup-form centrifugal commuter having a bottom and a circumferential wall extending upwardly from the bottom and having cutting teeth on the upper face of the bottom, a charging hopper with a neck at its lowerend delivering the charge into the interior of the comminutor, said circumferential wall having a plurality of slots through the same inclining rearwardly and outwardly with respect tothe direction of rotation so as to withdraw air from the interior of the hopper when the comminutor is rotating at a high speed, a removable cover for .the hopper, making a'substantially air-tight connection with the hopper cooperating with the ro tating comminutorto develop a partial vacuum within the hopper to augment the extraction of the juices as the cutting teeth function, a pulp screen having a circumferential wall surrounding the comminutor for retaining the pulp and permitting the juices to pass through, said casingv having a juice gutter below the pulp screen for encircling the comminutor, a removable annular pulp catcher having an inner wall adjacent the upper edge of the screen and over which the pulp passes into the pulp catcher, and seating on said seat. Y

10. In a centrifugal juice extractor for pulping pieces of a vegetable product, the combination of a centrifugal hollow comminutor, open above, and having a circumferential wall with cutters formed on the inner face thereof, means for rotating the comminutor at a high speed, relatively fixed =means including parts projecting down into the interior of the comminutor adjacent the inner face of the said circumferential wall, operating to retard the same sufficiently to enable the cutters to cut slices from the product but not to stop circumferential movement of the product by the leading the juices out of the machine, with an annular seat encircling the same, a removable annular pulp catcher having an inner Wall adjacent the upper edge of the screen and over which the pulp passes into the pulp catcher, saidf pulp 'catcher having an annular shoulder seating tightly on lsaid encircling seat, and having an outer wall and a cover for the casing in contact with the said outer wall of the pulp catcher, with means for tightening the same down so as to press the pulp catcher down tightly on said seat, said casing having a skeleton form cuter wall adjacent `the outer wall of the pulp catcher.

9. In a centrifugal machine for pulping vegetables or fruit, and extracting their juices, the combination of a casing, a cup-form centrifugal comminutor having a bottom and a circumferen tial wall extending upwardly from the bottomand having cutting teeth on the upper face of the bottom, a charging hopper with an outlet at its lower end delivering the charge into the interior of the comminutor, said circumferential wall having a plurality of slots through the same lnclining rearwardly and outwardly with respect 'to the direction :of rotation so as to withdraw air from the interior of the hopper when the comminutor is rotating at a high speed, a removable cover for the hopper, making a substantially airtight connection with the hopper cooperating with the rotating comminutor to develop a partial vacuum within the hopper to augment the I comminutor, and causing the pieces of the product to turn over and over as they progress interruptedly aroundl the interior of the comminutor and so as to present all sides of the same to the cutters.

11. In a rotary centrifugal juice extractor for forming pulp from pieces of a vegetable product, a. hollow comminutor open above to receive its charge and having a circumferential wall with slots cut through the same, said slots being inclined in an upward direction rearwardly with respect to the direction of rotation of the comminutor and having cutters formed at said slots on the inner face of the wall and on the rear side of the slots with respect to the direction of rotation, the said inclination operating to exert an upward thrust tending to lift and turn the said slots cut through the same, said slots being inclined in an upward direction'rearwardly with respect to the direction of rotation of the comminutor and having cutters formed at said slots on the inner face of the wall and on the rear side of the slots with respect to the direction of rotation, the axis of the horizontal cross-section of the said slots being inclined rearwardly toward the outer side of the wall with respect to a radial plane from the axis of rotation of thecomminuto'r, the said inclination operating to exert an upward thrust tending to lift and turn the said pieces of pulp upwardly at their` outer sides.

Y 13. In a rotarycentrifugal juice extractor for forming pulp from pieces of a vegetable product, a -hollow comminutor open above to receive its charge and having a circumferential wall with slots cut through the saine, and a thread cut on the inner face of said wall and crossing said slots to form cutting teeth thereat.

14. In a rotary centrifugal juice extractor for forming pulp from pieces of a vegetable product, a hollow comminutor open above to receive its charge and having a circumferential Wall with slots cut through the same, and a thread cut on the inner face of said wall and crossing said slots to form cutting teeth thereat, said thread having ,a pitch in a direction such that each thread rises y against the thread tends to raise the outer sides of the pieces, and turn them over.

l5. In a centrifugal machine for pulping pieces of produce such as vegetable or fruit, and extracting their juices, the combination of a, rotary centrifugal hollow comminutor element open above to receive its charge, and having a circumferential wall with cutters on the inner face thereof, said wall having openings therethrough through which the lpulp can pass outwardly, sai-d comminutor element operating to rotate its charge of produce with the rotation of the comminutor/lement on Yits own axis so that the structing means, thereby causing the pieces of produce to present all sides to the cutters in moving interruptedly around the interior of the comminutor. adjacent the inner face of said wall.

16. In a centrifugal machine for pulping pieces of product such asvegetable or fruit, and extracting their juices, the combination of a rotary centrifugal hollow comminutor velement open above to receive its charge, and having a circumferential wall with cuttersv on the inner face thereof, said wall having openings therethrough through which the pulp can pass outwardly, said comminutor element operating to rotate its charge of produce with the rotation of the comminutor element on its own axis so that the pieces to be pulped are held outwardly by the centrifugal force against the inner face of the circumferential Wall, and means lying adjacent to, and conned to, a point adjacent the said wall for obstructing and retarding the rotary movement of the outer portions of the charge, thereby causing the pieces of the charge adjacent the outer `wall to be turned about a more or less vertical axis when encountering said obstructing means, thereby causing the pieces of produce to present all sides to the cutters in moving interruptedly around the interior of the comminutor adjacent the imierface of said Wall, and means for maintaining the space in which the comminutor is located, in a state of partial vacuum to assist in withdrawing the juices.

17. In a centrifugal machine for pulping 'pieces of products such as vegetables or fruit, and extracting their juices, the combination of a rotary y centrifugal hollow comminutor element open above to receive its charge, means for preventing atmospheric air from flowing into the upper end of the comminutor, said comminutor having a circumferential wall with cutters on the inner face thereof, said comminutor element operating to rotate its charge of produce with the rotation of the comminutor element on its own axis, so that the pieces to be pulped are held outwardly by the centrifugal force against the inner face of the circumferential Wall, means cooperating with the cutters and located on the inner face of the Wall for enabling the cutters Ato bite into the pieces of the product constituting the outer portion of the charge, said wall having openings therethrough through whichrthe pulp produced by the cutters, can pass outwardly, and operating during the rotation of the comminutor element to exhaust the air from the interior of the comminutorelement and thereby reduce the air pressure therein and stimulate the extraction of the juices from the charge within the comminutor.

18. In a centrifugal machine for pulping pieces of product such as vegetable or fruit, and-extracting their juices, the combination of a rotary centrifugal hollow comminutor element open thereof, said wall having openings therethrough through'which the pulp can pass outwardly, said comminutor element operating to rotate its charge of produce with the rotation of the comminutor element on its own axis so that the pieces to be pulped are held outwardly by the centrifugal force against the inner face of the circumferential Wall, relatively .fixed means within the comminutor element lying adjacent to the path of the cutters cooperating with the cutters to temporarily retard portions of the charge adjacent to the cutters to effect the pulping of porfa tions of the charge lying adjacent the circumferential wall, said comminutor element having faces at said openings inclining rearwardly with respect to a radial plane and with respect to the direction of rotation, said inclined faces operat= ing to exhaust air from the interior of the comminutor element and thereby reduce the pres-11 sure therein and stimulate the extraction of the juices from the charge in the comminutor element. Y

19. in a centrifugal machine for pulping pieces of product such as vegetable or fruit, and extracting their juices, the combination of a rotary centrifugal hollow comminutor element open above to receive itsv charge, with a cover for sub` stantially sealing the comminutor 0E from the outside air, said comminutor having a circumfer ential wall with cutters on the inner face thereof, said wall having openings therethrough through which the pulp can pass outwardly, said comminutor element operating to rotate its charge of produce with the rotation of the comminutor element on its own axis so that the pieces to be pulped are held outwardly by the centrifugal force against the inner face of the circumferential wall, relatively fixed means within the comminutor element lying adjacent to the path of the cutters cooperating with the cutters to temporarily retard portions of the charge adjacent Ito the cutters to enable the same to bite into the outer 'portions' of the charge and form a pulp -from the same, the said openings having inclined faces inclined rearwardly with respect to a radial -plane and with respect to the direction of rotation, said inclined faces operating to exhaust air from the interior of the comminutor element and thereby reduce the pressure therein for stimulating the extraction of the juices from the charge.

20. In a, juice extractor, a' rotary comminutor having a disc with a continuous circumferential spiral convolution formed integrally with the disc, and on the upper face thereof disposed around the axis of the disc as a center, and hav-` ing slots through the same cutting across the cir-` cumferential convolutions to form a plurality of cutting teeth progressively more distant from the said axis for cutting into material above the disc.

21. In a juice extractor, the combination of a rotary comminutor having a disc with a continuous circumferentialv spiral convolution formed integrally with the disc, and on the upper face thereof disposed around the axis of the disc as a center, and having slots through the same extending in a ganeral radial direction and cutting across the circumferential convolutions to form .a plurality of cutting teeth progressively more distant from the said axis for cutting into material above the disc; and relatively xed means lying adjacent to the face of the comminutor for arresting portions of the vmaterial lying above the disc.

22. In a. machine of the kind described, the combination of a hollow rotary comminutor element open above to receive its charge on its inner side, and having a circumferential wall with slots therethrough, the rear edges of said slots 10 with respect to the direction of rotation being off- DANIEL T. NIcHoLsN.