US2525585A - Mixer - Google Patents

Description

Oct. 10, 1950 c, BRASINGTQN 7 2,525,585

MIXER Filgd Feb, 7, 1946 3 Sheets-Sheet 2 yl/IIIIIIIIIIIII/ IIIIII I i i z 9 5 /MK6,M

Och 1950 c. P. BRASINGTON 5,

MIXER 9 W Z 3 r0 I 1..- m a 1% w 45 m n e no 000 h S 3 Filed Feb. 7, 1946 INVENTOR.

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Patented Oct. 10, 1950 UNITED STATES PATENT OFFICE MIXER Charles P. Brasington, Cincinnati, Ohio Application February 7, 1946, Serial No. 646,072

6 Claims.

This invention relates to an improved mixer which is adapted particularly to be used in the preparation of fluid and viscuous compositions.

The principal objective of this invention has been to provide a machine which is more efficient in operation than the mixers now available, that is, a machine which requires less time to produce a given distribution of components one within the other, or a machine which in a given time is capable of producing a more thorough mixture.

Though the present apparatus is useful and is intended to be employed for a wide variety of purposes, it has been devised particularly in relation to the problem of distributing a dry powdery pigment throughout a vehicle such as a varnish or a paint medium. In such manufacture thoroughness of mixing and the tim required therefor are important cost consideracause the weighting of the pigment by the vehicle and to reduce the size of the pigment particles. However, if the preliminary mixing is not thorough, prolonged grinding on the mill is requisite, at high production cost. On the other hand, the preliminary mixers now available are not capable of providing thorough distribution of the pigment in the vehicle preparatory to final grinding unless the preliminary mixing operation is conducted over a long period of time. Thus, one of the main objectives of this invention has been to provide an improved apparatus in which a preliminary mixing operation can be conducted in a short period of time to such a degree of thoroughness that the time required for th final grinding operation is of short duration.

A further objective of the present invention is to provide a simplified apparatus utilizing a mixing element which may be cleaned very easily and with a minimum loss of time.

Briefly, the mechanism of this invention by which the desired results are obtained comprises a vessel having a circumferential side wall and a mixing element disposed at an angle bisecting the side wall and the bottom of the receptacle and having mixing blades disposed with respect to one another at an angle equal to the angle between the side wall and the bottom of the mix ing vessel. Both the mixing receptacle and the mixin element are rotated during themixing operation and, by virtue of the angular disposition of the mixing element Within the receptacle, as well as the arrangement of the blades: of the mixing element with respect to each other at an angle equal to the angle between the bottom and side wall of the receptacle, the blades progressively sweep past the bottom of the receptacle then past the side wall thereof, whereby material at the bottom of the container is lifted and com mingled with fluid material at the top of the container and vice versa, and thereby material adjacent the periphery of the container is advanced toward and commingled With material at the center thereof. In this manner the problem of stratification, which is encountered in the use'of many machines seemingly having thorough and efficient mechanism, is avoided. The mixing action, moreover, is thoroughly performed without great agitation and incorporation of air in the product is avoided.

In the preferred machines of th present invention a rotatable table is provided upon which mixing receptacles may be deposited for commingling of the contents stored therein; in this manner one batch after another of material may be treated in the machine and only the mixing element or paddle need be cleaned. However, the invention also contemplates machines in which the receptacle is built as an integral part of the apparatus.

In the preferred embodiment the mixing element is sustained upon a liftable arm which may be raised or lowered to introduce or withdraw the mixing element from the receptacle. When the arm is moved to raised position the mixing element occupies a position over the receptacle whereby surface liquid retained upon it drains or drips back into the receptacle after which the element is in an accessible position for cleaning.

From the foregoing principles upon which the present invention is predicated and from the following description of the drawings in which a typical embodiment of the apparatus is disclosed, those skilled in the art readily will comprehend the various modifications to which the invention is susceptible.

In the drawings:

Figure 1 is a side elevation of the apparatus.

Figure 4 is an end elevation of the machine taken on the line 4-4 of Figure 2.

Figure 5 is a fragmentary end elevation showing a portion of the drive and a portion of the arm lifting mechanism as taken on the line 55 of Figure 2.

Figure 6 is a fragmentary plan View showing the mixing element disposed within the receptacle in mixing position.

Figure 7 is an elevation showing a modified form of mixing element.

Figure 8 is a somewhat diagrammatic view showing the path of movement of the mixing element in various stages of a cycle of rotation thereofand the path of movement which the mixing element induces in the contents of the receptacle.

The machine, briefly, comprises a base i, a pair of uprights or columns 2-2 which are arranged in spaced relationship adjacent one another upon opposite sides of the base, an arm 4 pivotally mounted intermediate the uprights 2 adjacent the upper ends thereof, a mixing element indicated generally at 5 which is sustained upon the arm 4, and a mixing receptacle 5 which is rotatably mounted underneath the arm 4 upon the base The base i may be fabricated as a weldment consisting of side base plates 'l'i, end base walls 8-8, cross pieces 9 disposed at one end of the base to support a drive motor l5, and a cross web ll adjacent the opposite end of the base which forms the journal for rotatably supporting the receptacle 5. The uprights 2 are fastened to the side walls 7 of the base and, for rigidity, may be in the form of channel irons as indicated in Figure 3.

The arm 4 is also of weldment construction in the form of a box or tube comprising side walls l2 and top and bottom walls l3 and i4 respectively. The side walls 52 of the arm are bored in alignment to receive a cross shaft l5 which has its ends supported on the uprights 2. Collars 56 are fastened to the inner faces of the side walls 52 to form bearings of the arm upon the cross shaft.

The arm 4 is open at its rear end and a strap I! is disposed between the side walls thereof for supporting a journal block [8 which receives a drive shaft l9 passing longitudinally through the arm. Adjacent the strap if this drive shaft carries a gear 25. At the far end of the arm it is provided with an end piece M which is bored to form a journal for the opposite end of the drive shaft l9 which, beyond the cross piece 2!, carries a bevel gear 22. The shaft 59 preferably is rotatably journalled in anti-friction bearings 23 and 24 respectively.

The bevel pinion 22 is installed within a housing indicated generally at 25 which is mounted upon the end of the arm 4. This housing is of box construction and includes walls 25 and 27 which support bearings 28 and 29 in alignment with one another on an angle to the drive shaft IS. The bearings 28 and 29 receive a stub shaft 30 having a bevel gear keyed thereto as at 32 and this bevel gear is in meshing engagement with the bevel pinion 22. The lower end of the stub shaft 35 projects beyond the housing 25 where it is provided with a socket '53, for rigidly supporting one end of the mixing element 5 in driving connection therewith. For this purpose the socket 33 may be provided with a bayonet type slot 35a adapted to receive a pin 3317 projecting from the upper end of the mixing element shaft as shown in Figure 1.

The cross web H which is positioned between the side walls I of the base is bored to receive anti-friction bearings 38 which are in spaced relationship with one another surrounding a shaft 39 having a worm wheel 40 keyed thereto intermediate the bearings 38. A table 4| is keyed to the shaft 39 with its hub 42 resting on the upper bearing 38. The table 4| is of substantial diameter and forms the support for the receptacle 5.

Preferably, though not necessarily, locating blocks 43 are placed adjacent the outer periphery of the table 4! so as to center the receptacle 6 upon the table in order that it will be disposed substantially concentrically with respect to the axis of rotation of the shaft 39. If desirable, containers 6 may be employed having lugs 44 mounted at the outer periphery thereof for engagement with the locating blocks 43 of the table, whereby the receptacle 5 has a positive drive from the table.

As shown in Figure 2 the shaft of the mixing element 5 which projects from the socket connection 33 of the drive arm is disposed upon an angle which bisects the angle between the side Wall 45 of the mixing receptacle 5 and the bottom wall 45 thereof. The mixers carried by the mixing element 5 are in the form of two blades 4'! and 48. These are symmetrically mounted on the shaft of the element 5 and are angularly displaced with respect to one another at an angle corresponding to the angle between the side wall 45 and the bottom wall 46 of the mixer. Thus,

5 during each cycle of revolution the blades 41 and 48 respectively will each sweep past the bottom and side wall 45 of the mixing receptacle.

In the construction shown in the drawings the container illustrated is of true symmetrical configuration, that is, side wall 45 is at 90 with respect to bottom wall 46. However, the container may be of conical configuration and the side wall may be dished or domed. In such instances the angular relationships are adjusted accordingly, that is, shaft 5 is disposed upon an angle which bisects the angle between the side wall and an adjacent portion of the bottom wall, and the blades 47 and 48 are symmetrically arranged upon the shaft at an included angle correspond ing to. the angle between the side wall and an adjacent portion of the bottom wall of the receptacle.

The drive to the receptacle 5 and to the mixing element 5 is furnished from motor l0 which has two sprockets 49 and 50 mounted on the shaft thereof. One of these sprockets is engaged by a chain 5! and extends upwardly around a sprocket 52 which is mounted upon a jack shaft 53. This jack shaft is rotatably supported in pillow blocks 5454 which are mounted upon a pedestal 55 supported from and intermediate the uprights 2. The jack shaft has a pinion 56 at one end thereof which is in meshing engagement with the pinion 20 of the drive shaft [9.

The other of the motor sprockets 49 drives a chain belt 58 which extends downwardly around a sprocket 59 which is fixedto a base shaft 60. One end of the base shaft, adjacent the sprocket 59, is journalled in a pillow block 86a which is supported from one of the cross straps 9 of the motor mounting. The opposite end of the base shaft as is rotatably journalled in two pillow blocks 6.l5l which are supported upon spacers 52 fixed'to a side wall '5 of the base. Intermediate these pillow blocks the base shaft 60 carries a worm 63 which is in meshing engagement with the worm wheel 4|] of the table drive assembly. While a conventional motor is disclosed in the drawings it will be understood that a variable speed unit readily may be employed for convenient adjustment in the speed of operation of the apparatus.

As previously indicated, the arm 4 is liftable in order to permit a mixing element 5 to be raised from the mixing receptacle 6 whereby the latter may be taken from the table and whereby the former may be elevated to a position for cleaning. Inasmuch as the arm 4 has a substantial overhang from its pivot point about shaft l5 it is counterbalanced by means of a weight 64 which is carried upon the cables 66 which extend upwardly above the arm around pulleys 61 and into fixed connec tion with the arm at points forwardly of the pivot shaft l5. In the preferred construction the pulleys 61 are mounted upon a top shaft 68 which is rotatably journalled at its endwise portions in posts 69-- B9 extending upwardly from the tops of the side standards 2.

To control the raising and lowering of the arm 4 a hand-driven worm and worm wheel assembly 10 is utilized. This assembly includes a worm wheel ll which is fixed to the same shaft upon which the arm is fastened. Adjacent this worm wheel a bracket 14 is mounted on an upright 2 of the base and journal blocks 15 are fastened to this bracket, the upper ends thereof being offset so as to overhang the worm wheel 1 l. These journal blocks rotatably support a shaft 76 having a worm Tl fixed thereon in meshing engagement with the worm wheel ll. Shaft 76 extends rearwardly through another pillow block 78 beyond which the hand wheel 10 is fixed to it. Upon rotation of the hand Wheel the arm 4 is lifted through engagement of the worm Wheel 'II and worm Tl.

It will be noticed that this elevation of the arm disengages the pinion from the pinion 56. When the arm is lowered these gears are brought into reengagement and a positive drive is established from the motor to the mixing element 5. The final lowered position of the arm is governed by its engagement with an abutment 19 which comprises an angle member 80 extending across the two side members 2 of the machine and an adjustable stop screw 8| which is threaded through the angle member and which carries a lock nut 82. This adjustment permits the arm to be lowered until the shaft of mixer 5 just bisects the angle between the side wall and bottom wall of the mixing receptacle or, that is, until the blades 4'! and 48 are spaced to reside adjacent but to clear the side and bottom walls of the receptacle.

In the preferred construction of the mixer element the blades 47 and 48 thereof are welded to the lowermost extremity of the mixing element shaft symmetrically in the plane thereof. Likewise, the end of the mixing element shaft is chamfered or pointed so as to reach closely adjacent the bottom corner of the mixing receptacle and thereby prevent accumulation of unmixed element in the corner recesses. The upper or free ends of the mixing blades preferably are cross connected with the shaft by means of supplemental blade elements 83 and 84. These supplemental blades, as shown best in Figure 3, have one end thereof welded facially to a mixing blade 4'! or 48, while the opposite end thereof is welded tangentially to the shaft of the mixing element. The supplemental blades are useful in that they augment the mixing action provided by the main mixing CJI blades even though they do not sweep past the bottom and side Walls of the receptacle. An action is obtained in which respective portions of the fluid in the receptacle are folded together and thus thoroughly commingled.

In the alternative, a mixing blade may be employed like that shown in Figure 7. The selection of the one type of mixer in preference to the other is governed by the viscosity of the material which is to be treated.

The socket connection of the mixing element to the shaft 3E3 at the head 25 of the overhanging arm of the machine is useful because it reduces the down time of the machine between successive batches of material. That is, for instance, as a batch of blue paint has been mixed, then the mixer in the machine, contaminated with blue, may readily be removed, a clean fresh mixer element placed in the machine, a batch of material,

say of a different color mixed therein, and meanwhile the mixing element which has been removed may be cleaned for later use on a different batch of material.

It is to be noticed, as shown in Figure 8, that an orbital mixing action is obtained by this apparatus in which a local portion of material at an elevated position in the batch is induced to flow toward a local portion of material at a different elevation in the batch and at a different radial position. The general path of movement is indicated by the dot and dash ellipse shown in Figure 8. Whether the mixing receptacle be rotated in the same direction or counter to the direction of rotation of the mixing element, a thorough and rapid commingling of the compo-- nent parts of the material is obtained which, as the pigment or finely divided material becomes wetted by the fluid component, becomes akin to kneading of the product; and any tendency of various portions of the material to stratify on account of differences in specific gravity continuously is disrupted.

Having described my invention, I claim:

1. A machine for mixing a color pigment with a fluid vehicle comprising: a base, a table rotatably mounted thereon, a cylindrical receptacle mounted upon said table, an arm, pivotally mounted on said base and adapted to overhang said receptacle, means for pivotally raising or lowering said arm, a drive shaft extending through said arm, a mixer shaft journalled in the end of said arm and extending at an angle into said receptacle when said arm is in operating position, paddle elements mounted upon said mixing shaft, gear means connecting the mixing shaft to said driving shaft, a driven gear secured to the opposite end of said driving shaft, a drive gear mounted on said base and arranged to mesh with the driven gear when the arm is in operating position with respect to said receptacle and a driving motor in common driving connection with the rotatable table and said drive gear whereby said drive shaft automatically is disengaged from said driving gear when the arm is pivoted to an inoperative position to halt rotation of the paddle elements without stopping the motor and table.

2. A machine for mixing a color pigment with a fluid vehicle comprising; a base, a table rotatably mounted thereon, means for driving said table, a cylindrical receptacle mounted upon said table, an arm, a pivot shaft mounted on said base and adapted to support said arm-in position to overhang said receptacle, means for pivotally raising or lowering said arm, a drive shaft extending through said arm beyond said pivot shaft, a mixer shaft journalled in the end of said arm and extending at an angle into said receptacle when said arm is lowered into operatin position, paddle elements mounted upon said mixing shaft, gear means connecting the mixing shaft to said driving shaft, a driven gear secured to the opposite end of said driving shaft beyond said pivot shaft, a drive gear mounted on said base and disposed above said driven gear,

said drive gear arranged to mesh with the driven gear when the arm is lowered into operating position with respect to said receptacle whereby said drive shaft automatically is disengaged from said driving gear when the arm is raised to an inoperative position.

3. A machine for mixing a color pigment with a fluid vehicle comprising; a base, a table rotatably mounted thereon, means for driving said table, a cylindrical receptacle mounted upon said table, an arm, a pivot shaft mounted on said base and adapted to pivotally support said arm in position to overhang said receptacle, a worm wheel keyed to said pivot shaft, a worm, meshing with said worm wheel, hand means for rotating said worm, a drive shaft extending through said arm, a mixer shaft journalled in the end of said arm and extending at an angle into said receptacle when said arm is in operating position, paddle element mounted upon said mixing shaft, gear means connecting the mixing shaft to said driving shaft, a driven gear secured to the opposite end of said driving shaft, a drive gear mounted on said base and arranged to mesh with the driven gear when the arm is in operating position with respect to said receptacle whereby said drive shaft automatically is disconnected from said driving gear when the arm is pivoted to an inoperative position.

4. In a machine for mixing pigment with a fluid vehicle, a receptacle having a substantially flat bottom and a circular side wall mounted to rotate about its own vertical central axis, a rotatable drive shaft adapted to rotate about an axis which lies within a plane through said vertical central axis and which is along a line bisecting the angle between the bottom and side wall of the receptacle, a straight edged paddle blade mounted on said drive shaft at an angle equal to one half that between the bottom and side wall of the receptacle and adapted to generate a right circular cone upon rotation of the shaft which has a slant height greater than the radius of the bottom but less than the diameter of said receptacle and which has its apex at a point on the juncture between the bottom and side wall of the receptacle.

5. In a machine for mixing dry pigments with a liquid vehicle, a rotatable table, a cylindrical mixing can mounted for rotation upon the said rotatable table, the said cylindrical can having a side wall and bottom disposed substantially at an angle, a mixing element comprising a drive shaft extended into the cylindrical can at an angle bisecting the side wall and bottom of the can, the drive shaft having a pair of mixing paddle blades secured thereto, said blades extending from the projected end of the drive shaft and being symmetrically disposed in respect to said shaft, the included angle defined by the blades upon rotation of the said shaft corresponding to the angle between the side wall and bottom of the can, said mixing blades being mounted on said shaft to pass substantially in scraping contact successively across the side wall and bottom of the can during rotation of the drive shaft, the length of the said blades being greater than the radius of the can, so that a portion of each blade extends beyond the center of rotation of the can and is adapted to sweep substantially in scraping contact over and beyond the center of can rotation, driving means for rotating the drive shaft about its axis, and driving means for rotating the table and mixing can about its center of rotation.

6. In a machine for mixing dry pigments with a liquid vehicle, a cylindrical mixing can mounted for symmetrical rotation about an axis, the said can having a side wall and bottom disposed substantially at an angle to one another, a mixing clement comprising a drive shaft projecting into the can at an angle bisecting the said angle between the side wall and bottom of the can, said drive shaft having a lower end configurated in shape to conform to the can juncture between the bottom and side wall of the can and disposed substantially in scraping relationship therewith during rotation of the can, a pair of mixing paddle blades secured to the said drive shaft, said paddles being symmetrically disposed on said drive shaft at an included angle equal to the angle between the side wall and bottom of the said can and bisected by the axis of the drive shaft, the said mixing blades extending from the end of the driving shaft and arranged to pass substantially in scraping contact with the side wall and bottom of the can during rotation of the drive shaft, the length of the paddle blades being greater than the radius of the mixing can, with a portion of each blade extending beyond and adapted to sweep over the center of rotation of the mixing can, driving means for rotating the said drive shaft and paddle blades, and driving means for rotating the said can about its axis of rotation.

CHARLES P. BRASINGTON.

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

UNITED STATES PATENTS Number Name Date 291,460 Stanyan Mar. 19, 1878 1,290,045 Bachman Jan. 7, 1919 2,036,112 Aeschbach Mar. 31, 1936 2,390,742 Setterlund Dec. 11, 1945 FOREIGN PATENTS Number Country Date 285,168 Germany June 23, 1915 368,920 Germany Feb. 12, 1923 397,129 France Feb. 15, 1909 571,681 France May 21, 1924

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