US2524751A - Comminuting machine - Google Patents

Description

oct'. 1o, 195o J. l.. BERGER COMMINUTING MACHINE 3 Sheets-Sheet 1 Filed Feb. 4, 1947 INVENTOR.

Oct. l0,v 1950 J. L. BERGER 2,524,751

cpmINuTING MACHINE A Filed Feb. 4. 1947 s sheets-sheet 2 FIGZ Oct. l0, 1950 J. l.. BERGER CDMMINUTING MACHINE 3 Sheets-Sheet 5 Filed Feb.. 4. 4'3.947

INVENTOR.

yuan/90a@ the Whiting was added at the disintegrator.

Patented Oct. 10, 1950 strong Cork Company,

ration of Pennsylvania.'

Lancaster, Pa., a corpo- Application February 4, 1947, seem No. 726,421

(c1. A18g-'12) This invention relates tota` comminuting Ina-v chine, and, more particularly, to a machine in which a mass of plastic composition is reduced to ne particle size in one operation, thereby doing away with a series Iof operations as required by present practice.

In the manufacture of floor coverings, of the inlaid linoleum type, it has been common practice to mix the color composition in a conventional mixer, such as a German mixer, from which the composition is Vextruded in long rodlike pieces. These rods of color composition are then fed to a two-roll calender which forms the color composition onto a thin sheet, the sheet adhering to one of the calender rolls'. A third roll, known as a scratcher roll, operates 'in such a manner that pins positioned on the surface thereof dig into the 'sheet of' color composition and scratch or tear the sheet into particles. rIhese particles then passv into'a' disintegrator period of time after its initial processing. During this storage, there-is a tendency for the particles to cohere torone another and form cakes of color composition which are not suitable for use inthe subsequent manufacturing operations.

In Vorder to prevent this caking, ithas been common practice to add a powder, such as Whiting,

l to-coat the particles and .thereby prevent them from cohering. In the process used heretofore,

Inasmuch as the use of a conventional disintegrator is eliminated in my process, I have found it advantageous t`` add the whiting at the time the composition is reduced to fine particle size.

With the advent of the newer type, iioor coverings, such. as those made from vinyllchloride.-

vinyl acetate copolymer, it has been found that theconventional scratcher, equipment described above is not effective for reduction of 'the mass,

since the composition` does not form atight.

blanket on the calender roll, but, instead, forms they break off large jsections of the sheet which are too large for the subsequent .processing steps.

Also, Yin the processing ofv vinyl chloride-vinyl,

claims.

particles. When operatingv at these higher tem peratures, the particles have a tendency to cohere when they come in contact with one another upon formation and, unless their temperature is reduced to a degree at which they will not readily cohere, an unworkable mass results.

In the past, comminuting machines have been built comprising a mixer, having an extrusion die and a rotating cutter slidably engaging the exterior surface of the extrusion die. Machines of this type are not satisfactory for comminuting plastic compositions of the vinyl chloride-Vinyl acetate type, since the sliding knife has a tendency to smear the plastic composition rather than shear it. In order to overcome this, I have provided a device in which the comminuting pins do not engage the surface of the extrusion die, but strike the extruded mass as it is being projected from the extrusion die.

An object of this invention is to eliminate some of the processing steps heretofore required in the processing of plastic color compositions for the production of sheet materials.

Another object of my invention is to provide a device in which the hot color composition as formed into particles is cooled to a temperature Where the particles will not cohere,

A still further object of my invention is the provision of a device for reducing plastic com-- position to small particles in one operation, thereby eliminating many of the difficulties encountered heretofore in trying to break down the plastic compositions.

In order that my invention may be more readily understood, it will be described in connection with the attached drawings, in which:

Figure 1 is an elevational View partly in cross section, showing the device of my invention,

4Figure 2 is an enlarged cross-sectional View showing the discharge end of a mixer with the comminuting device in position for operation,

acetate compositions, a highertemperature isyre,` quired inmixingfin .order toset 'proper .dlistnbuam of` the. Vbinder @Imposition .overt .the nu@ the bell-shaped housing to which vthe backingv plate` shown in Figure 3 is attached,

Figure 8 is a side elevational view of the hood surrounding the device of my invention, and

Figure 9 is a cross-sectional view taken on the line IX-IX of Figure 8, showing the hopper, motor, and conveyor for supplying powder to the hood.

Referring to Figure 1, there is shown a conventional German mixer 2, having an intake hopper 3, through which the charge is fed into the mixing chamber 4, wherein the charge is processed by mixing blades, several of which are shown at 5. It will be understood that'mixing blades similar to those shown at 5 are provided throughout the entire mixing chamber 4; `After the ingredients have been thoroughly mixed into a homogeneous mass, the mix is extruded through the elongated oriiices 6 in thetail plate 1, which is secured to the mixer by means of studs 8. This tail plate is more clearly shown in the enlarged view illustrated in Figures 2 and 4.

Figures 1, 2', and 7,-' show-a bell-shaped casting 9 positioned adjacent the extruding end of the mixer. The bell 9 is mounted by means of its hub'IU on the shaft IIV of a motor I2, Yor other suitable source of motive power. Secured to the bell 9 by means-of studs I3 is a circular plate or disc I4 having a plurality of pins I5 rigidly aiiixed thereto. These pins I5 are of a diameter smaller than the width, but not necessarily smaller than the thickness o f the mass being extruded through the orices B in the tail plate 'I. In addition to the c ircular` plate I4, the bell 9 also has a casting I6 secured to it by means of studs I'I.` Thiscasting I5 carries a series of fan blades I8. 1' 1:.' u n w It will be obvious from an examination oi Figures 3 and 4 that the'V arrangement of the pins in'platef I4 is such Vthat their projected surface will cover the entire area of the orices 9 during each rotation of the disc I4.

It will be noted 'from Figure 1 that the motor and bell assembly areslidably mountedon the support I9 to permit-lateral or axial movement of-this" as'sembly"w'ith`respect to the mixer 2. Thisslida'ble nounti'ng makes it possible to accurately adjust the* clearance between'the tail plate i and the -c'omminuting pins I5. This "is accomplishedAb3 means'of the screw 29 on the support`I9 which threadedly engages'the shoulder 2Ion the slidablemounting 22. It will be clear from this disclosureV that the motor and bell assembly Vmay be moved'laterally with respect to the mixer by merely turning the crank 23. The preferred clearance between the comminuting pins and the tail plate is .010; however, satisfactory results are obtained with clearances ranging from .095" to .020, or greater, depending upon the size of the particles desired, the physical characteristics of the material being operated upon, and other variable factors.

I have found that satisfactory results are obtained when the bell 9 is rotated at 3600 R. P. M.

It will be readily understood that when operating at this speed, the comminuting pins impart considerable centrifugal force to the small particles of composition as they are broken oi the extruded mass'. 'Ifo direct and collect these particles, I provide a spiral-shaped collector hood 24, shown in Figures 8v and 9.

Referring to Figure 3, it will be understood that the longitudinal axis of the bell is in the center oi the circular housing offset 25, and during the operation of the device the smail particles are thrown oi in arcs tangential to the circular housing offset 25. Particles traveling through arcs which clear the dividing point 26 will travel down the chute 2'I into a suitable sieve (not shown). Particles travelling through arcs which fall short of the point 26 will continue around the inner circumference of the hood 24 by means of the air blast created by the fan blades I 8 secured to the rotating bell, and pass down through chute 21.

In order to supply Whiting or other powder suitable for preventing the particles from cohering to one another, I provide a hopper 28 (Figure 9) havingv a trough-shaped bottom portion at 29, in which is positioned a screw conveyor 39, operating' in Ya tube 3I and driven through a shaft V3,21by motor 33. It will be understood, of course, that this screw conveyor can be driven by the motor I 2 used to rotate the bell 9; however, in the embodiment illustrated, I use a separate motor 33. The screw conveyor 30 carries the Whiting horizontally into a chamber 34 positioned between the discharge tube 2I and the hood 24. When the powder is in the'chamber 34, it is in the path of a compressed air blast directed through tube 35. This compressed air blast forces the powder out of the chamber 34 through tube 35 and discharges it into the area surrounded by the hood at point 36, which is in substantially the same vertical plane as the free ends of the comminuting pins 'I 5.Y This powder is carried around with the air blast caused by the blades I8.

In order to effect a substantial reduction in the temperature of` the particles immediately after they are 'formed to prevent them from cohering, I provide air intake openings 31 to which may be attached iiexible hose orother'conduits from sources outside the'machine, for supplying air to theinterior of the hood; If necessary, refrigerated air can'be supplied to the hood.

In the operation of mycomrninuting machine, the ingredients to be mixed to form the nal comminuted'"composition are fed through the hopper 3 into the mixing chamber 4 where they arethoroughly mixed by the blades 5. After the ingredients are thoroughly mixed, the homogeneous mass is extruded through the oblong oriiices I i inthe tail plate 'I attached to the mixer. As the homogeneous mass is extruded through the orices 6,' the comminuting pins I5 secured to the bell 9 which'rotates about an axis the same as the'horizontal axis of the tail plate 'I, strike the extruded mass and break it into small particles. The arrangement of the comminuting pins I5 on the plate I4 is such that their projected surface covers the entire area of the orifices 6 during each rotation of the disc. The size of` the particles may be controlled by the speed'of rotation or the bell, by the number of comminuting pins in the plate I4, or by the clearance between the tail plate 1 and the comminuting pins I5;

The particles travel in arcs tangential to the circular path of the comminuting pins as they are broken oil? by these pins, and the particles are coniined and directed by a, spiral-shaped hood 24 which surrounds the rotating bell. All particles which are not thrown directly into the discharge chute 2'I are carried around the hood by means of the'air blast created by the fan blades I 8. A powder such as Whiting is forced into the hood 24 through tube 30, the discharge end of which is in the same vertical plane as the free ends of the comminuting pins I5. The purpose of this powder is to coat the particles to prevent them from cohering to one another. Air

is supplied to the hood from the outside through the air intake openings 31 in the hood 24.

It will be clear from the above description that I have provided a machine in which the comminuting operation, the cooling operation, and the particle coating operation, are carried out in one processing step, thereby eliminating the processing chain used heretofore in the mixing and disintegrating of plastic color composition used in the manufacture of sheet material.

While I have illustrated. and described certain preferred embodiments of my invention, it will be understood that the same is not limited thereto, but may be otherwise embodied and practiced within the scope of the following claims.

I claim:

1. A comminuting machine comprising a device for extruding plastic composition through a plurality of oblong orifices in an extrusion die, a disc carrying a plurality of comminuting pins positioned adjacent the extruding end of the extruding device, said pins intersecting the path of the extruded material and being so arranged that their projected surface covers the entire area of the orifices, said extruding die and said disc carrying the comminuting pins being on the same longitudinal axis, means for rotating said disc, and means for adjusting the clearance between the comminuting pins and the extruding die.

2. A comminuting machine comprising a device for extruding plastic composition through a plurality of orifices in an extrusion die, a disc carrying a plurality of comminuting pins positioned adjacent the extruding end of said extruding device, said pins intersecting the path of the extruded material and being spaced from the extruding die and facing in a direction opposed to the direction of travel of the extruded mass, the arrangement of said pins being 4-such that their projected surface covers the entire area of the orifices, said extruding die and said disc carrying the comminuting pins being on the same longitudinal axis, means for rotating said disc, and means for adjusting the clearance between the comminuting pins and the extruding die.

3. A comminuting machine comprising a device for extruding plastic composition through a plurality of oblong orifices in an extrusion die, a disc carrying a plurality of comminuting pins positioned adjacent the extruding end of the extruding device, said pins being of a diameter less than the width of the individual orifices and being arranged so that their projected surface covers the entire area of the o rices, said extruding die and said disc carrying the comminuting pins being on the same longitudinal axis, means for rotating said disc and means for adjusting the clearance between the comminuting pins and extruding die.

4. A comminuting machine comprising a device for extruding plastic composition through a plurality of oblong orifices in an extrusion die, a disc carrying a plurality of comminuting pins positioned adjacent the extruding end of the extruding device, said pins being of a diameter less than the width of the individual orices and having flat tips of reduced cross-sectional area, said pins being spaced apart at their working surface and being so arranged that their projected area covers substantially the entire area of the extrusion orifices, said extruding die and said disc carrying the comminuting pins being on the same longitudinal axis, means for rotating said disc and means for adjusting the clearance between the comminuting pins and the extruding die.

5. A comminuting machine comprising a device for extruding a plastic composition through a plurality of orifices in an extrusion die, a disc carrying a plurality of comminuting pins positioned adjacent the extruding end of the extruding device, said pins intersecting the path of the extruded material and being so arranged that their projected surface covers the entire area of the orifices, said extruding die and said disc carrying the comminuting pins being on the same longitudinal axis, and means for rotating said disc.

JOHN L. BERGER.

REFERENCES CITED The-following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 383,713 Deissler May 29, 1888 960,143 Anderson May 31, 1910 1,713,719 Severson May 21, 1929 2,422,480 Gordon. -f, June .17. 1947

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