US2473770A

US2473770A - Art of mixing

Info

Publication number: US2473770A
Application number: US492014A
Authority: US
Inventors: Harry J Seaman
Original assignee: Individual
Current assignee: Individual
Priority date: 1943-06-24
Filing date: 1943-06-24
Publication date: 1949-06-21
Anticipated expiration: 1966-06-21

Description

June 21, 1949. I v EAMAN 2,4733% ART OF MIXING Filed June 24, 1943 ATTORNEYS Patented June 21, 1949 UNITED S TATES PATENT QFFICE ART OF MIXING Harry J. Seaman, Milwaukee, Wis.

Application .lune'24, 1943, SeriaIiNO. 4923114 (Cl..9'4i44;)

1 Claim. 1

This invention relates 'to improvements in the art of mixing. It is particularly concerned with apparatus and methods for pulverizing and mixing materials situ.

It is a primary object of the invention to secure in a single traverse of the work a more complete distribution and intermixing of all grades and sizes of particles of material than has heretofore been possible. While the invention is not limited to any specific class of materials or type of mixing operation, it may be exemplified by referring to the use of the invention in making soil-concrete. The use of clean sand, substantially free of clay, used to be thought necessary for the manufacture of strong concrete. has been found that ordinary soil mixed with cement will give a very strong concrete provided the soil particles are reduced to sufficient fineness and the "cement is distributed through the soil particles sufiiciently thoroughly, and the fines, both of soil and cement, are distributed between the coarser particles in such a manner as to leave no voids. When these conditions are satisfied, the resulting concrete is extremely compact and dense and has great strength.

Other typical mixing jobs involve the stabilization of soil with sand "asphalt or asphalt emulsion or mixtures of sand with clay, or the mixing of binders with materials other than soil. It has heretofore been proposed to do all of these mixing jobs by traversing the materials to be mixed with a soil tiller of the general type shown in my former Patent 2,214,702, granted September 10, 1940. As compared with the mixing job done by the apparatus there illustrated, I seek to secure greatly improved thoroughness of mixing and distribution by means of the present invention.

t is another object of the present invention to provide for the levelling of the surface traversed by the apparatus to an improved degree, leaving a smooth, level, hardsurface irrespective of such substantial irregularities as transverse furrows in the ground over which the'process and equipment are operated.

In the drawings:

Fig. 1 is a view partially in side elevation and partially in longitudinal section showing .apparatus for the practice of this invention.

Fig. 2 is a diagrammatic view in section showing the apparatus in operation for the practice of the method.

Like parts are identified by the same reference characters throughout the several views.

In general, the apparatus is quite similar to that In past years, it e disclosed in my former patent identified above. There is a wheeled frame 3 from which power is transmitted through the housing -4 to a shaft 5 which carries "a number of springtines at '6. This shaft projects laterally from a gear case '1' to which is connectedasupporting shoe 8, the "shoe being "adjustable through means not here pertinent, either clockwise or counterclockwise about the axis of the shaft '5 to determine the level at which the device will operate. The shoe tends to ridesubs'tantia lly horizontally and, according to its angular adjustment, the case .I and shaft '5 will be supported at 'difierent levels with reference to the *ea-xth'tra'versed.

A part of the weight of the housing 4., case '1 and the

rotary mixing assembly

5, 6, is carried by utension spring 9 supporting the housing 4 from the post IU of the frame. Another part of the weight of the assembly is supported .by means of link I I andcompression spring f2 from a subf-rame 15 which is pivoted at T6 to the frame and adjustable by means of the hydraulic cylinder 1? and piston 18.

The rotary mixing assembly is enclosed by a hood EB-connected tothe'irameby means of arms El for upward and downward oscillation. The link rod fiend compression spring 23 partially support the weight oi the hood from the subframe l5 so that the hood, like therotary mixing assembly, will partake .of the adjustment effected by the hydraulic cylinder and piston I1 and 18. While the general relation of the hood to the mixing assembly is thus approximately maintained, the "separate link rod 22 and spring 23 permit the hood to'have bodily movement independently of the mixing assembly.

For ,purely till'ing purposes, the hood preferably comprises hingedly 'yieldable panels '24 and 25 against which the :material dislodged by the tines 8 is primarily directed for pu'lverization. The *yie'ldability of these "panels upon the respective hinges permits them to clear stones and other obstructions such as are "encountered when the machine is being used for tillage. It is,

' however, an important feature of the present invention that these panels be latched down tojpreclude their movement independently .of the hood in its -'ent'irejty. For thisjpurpose, "the panel .25 is provided with an 1933! "at {26 through which bolt 2-? passes into engagement with the 'keeper'28 on the side of the hood. This precludes any independent'y'ielding movement of the panels when the apparatusis being used for mixing.

*Theuseo'f a demountslble iforarninous plate to, serving as a screen, is optional. The plate is pro- 3 vided with a hook at 3! which may be engaged over a cross rod 32 of the hood. Where the plate is used, it tends to force toward the bottom of the excavation made by the tines B such irreduceable coarse particles as will not penetrate the apertures of the plate.

While apparatus other than that illustrated may be used to perform the mixing method embodying this invention, the apparatus disclosed is particularly adapted for use in the practice of said method. In order to use it for mixing, as distinguished from tillage, the apparatus is operated with the

hood panels

24 and 25 fastened down so that the chamber provided by hood is substantially closed. It is immaterial that the slots 33 and 34 for the housing 4 and the link rod l i are open. The places where closure is most desirable are at the front and rear. The panel is operated at such a level, as indicated in Fig. 2, as to function as a scraper. Being locked aaginst yieiding, it scrapes before it a substantial pile of pulverized material at 35. Thus the chamber within which the rotary mixing assembly functions is not only closed by the panel 25 but also is sealed by the mass of pulverized material 35 scraped ahead of such panel. This results in a very substantial portion of the pulverized material being caused to circulate around the interior of the generally cylindrical chamber in which the rotary mixer is operated. Such material, comprising mostly fines but some coarse material, moves clockwise with the mixing assembly, as viewed in the drawings, and is discharged from the free forward margin 36 of the hood to fall in a transverse windrow directly in u the path of the tines E of the mixing assembly. Thus, as such assembly rotates at high speed, it not only cuts into the previously unworked material at 3'! but, in reaching such unworked material, the tines pass downwardly through the fines and aggregates which have already passed about the hood and lodged in the windrow 38. The windrow 38 approximately, although not necessarily completely, closes the hood 20 at its forward side. As a result of the passage of the tines through this windrow and then through the previously unworked material, a much higher degree of perfect mixing action is secured than would otherwise be possible.

If the

panels

24 and 25, or particularly the latter, are left free for hinged movement, as in ordinary tillage, the amount of material making a circuit about the interior of the hood and deposited in the windrow 33 is greatly reduced and the mixing action is correspondingly less effective. Another mixing operation is also less effective under those circumstances. The pile of material scraped at 35 before the panel 25, when the panel is latched down, is in itself a very important factor in securing a perfect mix. The particles in the pile 35 are continually caused to churn over upon each other as the scraper portion 25 of the hood advances. Finally, such particles are forced into intimate contact by the wedging action and weight imposed thereon as the scraper passes over them. When the scraper panel 25 is not fastened down, even a small pebble or lump will lift this panel to discharge a very considerable quantity of the material that would otherwise be scraped forwardly. It is not possible under such circumstances to accumulate any mass of material at 35 because such mass of material, apart from any stone or lump, would of itself effect the lifting of the panel and the discharge of the material.

It will be apparent that the device and method as disclosed will also effect a levelling operation. As indicated at 39, the material not yet acted upon by the device is, or may be, quite irregular. The surface at 40 of the material compacted and leveled by the scraping panel 25 is smooth and hard. It is even possible to operate transversely of the furrows of a previously plowed field and to leave such a field completely level. The scraping panel 25 operates to accumulate the excess material of the ridges and to deposit such excess material in the furrows.

As will be apparent from the general description of the invention, if the material to be mixed comprises more than one separate ingredient, the several ingredients are aggregated or associated in the path of advance of the mixing implement and hood. For example, where cement or asphalt is to be mixed with soil, or sand is to be mixed with a clay soil, the cement, asphalt or sand may be deposited in piles or windrows 4| so distributed over the surface of the natural soil as to give approximately the correct proportions when mixed. Any number of ingredients may be thus associated, whether or not one or more of these comprises natural soil.

By operating the rotary mixing assembly in a substantially closed chamber and ahead of an inclined scraper edge as herein disclosed, I effectively distribute the particles of differing sizes throughout the mass of material acted upon and effective!" compress and compact the material to eliminate voids and secure a perfectly mixed product. Referring again to the soil-cement example chosen to illustrate the invention, a core taken from concrete made of soil and cement mixed in accordance with this invention will be smooth, compact and dense as compared with the relatively coarse, porous and rough concrete produced by apparatus and methods heretofore known.

I claim:

In a device of the character described having a rotary tilling head, means for rotating said head at high speed in a direction to throw tilled material rearwardly and a hood with a rearwardly inclined panel, the combination with said hood and panel, of an inclined foraminous screen mounted within the hood forwardly of the panel and at a steeper angle of inclination than the panel, said screen having openings adapted to pass fine material dislodged by said head and to force coarser material downwardly to be covered by such fine material, and means for releasably securing the panel against change of angular position respecting the hood, said panel having a hinged connection with the hood whereby to be floating when said means is released.

HARRY J. SEAMAN.

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

UNITED STATES PATENTS Number Name Date 1,512,596 Hamshaw Oct. 21, 1924 1,676,646 Funk July 10, 1928 1,878,442 Hamshaw Sept. 20, 1932 2,090,290 Gardner Aug. 1'7, 1937 2,181,320 Flynn Nov. 28, 1939 2,214,702 Seaman Sept. 10, 1940 2,289,334 Matter Oct. 20, 1942