US3693944A - Grain stirring apparatus - Google Patents

Abstract

A grain stirring device includes an endless flexible conveyor which is mounted on a supporting structure for movements about a circuitous path and for rotation of the circuitous path on a vertical axis within a circular grain drying bin and power means is provided to impart the circuitous and rotational movements upon proper energization of the power means.

Description

United States Patent Murphy 7 [451 Sept. 26, 1972 [54] GRAIN STIRRING APPARATUS [72] Inventor: David M. Murphy, RFD 4,

Mason City, Iowa 50401 [22] Filed: Aug. 13, 1971 21 Appl. No.: 171,421

[52] US. Cl ..259/114, 259/46 [51] Int. Cl. ..B0lf 5/26 [58] Field of Search ..259/99, 102, 111, 37, 40, 19,

[56] References Cited UNITED STATES PATENTS 3,156,541 11/1964 Kalke ..-.259/111 3,251,582 5/1966 Murphy ..259/l11 3,294,491 12/ 1 966 Brown ..259/ l 02 3,412,982 11/1968 Feteri ..259/37 3,445,091 5/1969 Jackson ..259/1 1 1 3,580,549 5/1971 Murphy ..259/1 11 Primary Examiner-Robert W. Jenkins Attorney-Merchant & Gould [5 7] ABSTRACT A grain stirring device includes an endless flexible conveyor which is mounted on a supporting structure for movements about a circuitous path and for rotation of the circuitous path on a vertical axis within a circular grain drying bin and power means is provided to impart the circuitous and rotational movements upon proper energization of the power means.

7 Claims, 7 Drawing Figures PATENTEDsms m2 SHEET 1 0F 2 PATENTED EP 26 9 3.693.944

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INVENTOR.

DAVID M MURPHY A7 TORNE Y5 1 GRAIN STIRRING APPARATUS BACKGROUND OF THE INVENTION 1. Field of the Invention:

It is current practice to dry grain or other likematerials by placing same in a cylindrical container or bin and forcing heated air upwardly therethrough. Such drying operations have resulted in various problems and the need to develop other methods to more efficiently dry the grain. An example of two methods of drying grain are batch drying and layer drying. Neither of the abovementioned drying methods are economically acceptable since both require considerable effort and man hours of labor to complete. Additionally, problems such as uneven drying, incomplete drying and crusting of the upper surface of the grain have further complicated such drying operations with the result that excessive insect infestation and/or spoilage and expense have occurred with the use of the above methods. A more acceptable method of drying grain has been deep bed drying in which the bin is substantially filled with grain and a mixing device, such as that disclosed in my prior US. Pat. No. 3,251,582, issued May 17, 1966, is used to constantly stir or mix the grain throughout the drying cycle. Such devices are normally constructed to provide a mixing device which automatically travels a predetermined path circumferentially and radially within the bin, during the drying cycle, to overcome the above problems.

2. Description of the Prior Art:

Present prior art stirring devices present problems in that, due to construction, such devices have not been able to sufficiently'mix or stir the grain or material in close proximity to the bin wall and are rather complicated and expensive .to manufacture. Such incoinplete stirring or mixing results in a longer drying period and the need for special manual adjustments to the stirring device to cause same to remain in the vicinity of the outer circular wall of the bin for a longer period of time. This is necessary due to increased moisture or condensation adjacent the interior of the metal bin wall which creates additional drying problems. Causing the stirring device to remain in the vicinity of the outer bin wall presents an additional problem in that the remainder of the grain or material in the bin is exposed to the flow of heated air for an excessive period of time and the grain-or material'is overheated or over-dried. If such adjustments are not made, the grain or material near the outer bin wall is not dried sufficiently and infestation and/or spoilage soon occurs. Additionally, that portion of the grain lying adjacent the bottom wall of the bin is, even under normal conditions, subjected to a much greater degree of heat than that lying thereabove since the heated air cools as it progresses upwardly through the grain. Prior art stirring devices have failed to provide for proportionally greater circulation of grain in this area with the result that this grain may be over-heated or over-dried relative to the remainder of the grain thereabove within the bin.

SUMMARY OF THE INVENTION The present invention is constructed of an endless flexible conveyor supported in the grain drying bin for movements of the conveyor about a circuitous path which lies in a plane extending generally radially from the vertical axis to the circular outer wall between the upper and lower wall of the drying bin and for rotary movements of the support means on a vertical axis coaxially disposed with respect to the vertical axis of the drying bin. Power means is operatively mounted to impart the circuitous movements to the conveyor and independent power means imparts rotational movement to the support means and conveyor mounted thereon during circuitous movements of the conveyor.

It is an object of the present invention to provide a grain stirring device which stirs and/or mixes the grain throughout the bin in which it is being dryed a proportionate amount to permit drying of such grain in a minimum of time and with but a minimum of labor.

It is another object of the present invention to provide a device of the above character which is easily in stalled in cylindrical grain drying bins presently manufactured, durable in use and extremely dependable in operation.

It is a further object of the present invention to provide a device of the character above described which consists of relatively few moving parts, requires a minimum of skill and manual adjustments to operate and is relatively inexpensive to manufacture.

These and other important objects will become apparent to those skilled in the art upon reference to the accompanying specification, claims and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS Referring to the drawings, wherein like characters indicate like parts throughout the figures:

FIG. 1 is a view in vertical section of a grain drying bin illustrating the present invention in side elevation and mounted thereon, portions thereof being broken away and shown in section;

FIG. 2 is a fragmentary view in horizontal section as seen generally from the line 22 in FIG. 1 on an enlarged scale;

FIG. 3 is an enlarged view in vertical section as seen generally from the line 3+3 of FIG. 1, portions thereof broken away;

FIG. 4 is a fragmentary view in vertical section as seen generally from the line 4-4 of FIG. 3;

FIG. 5 is a view in horizontal section on an enlarged scale as seen generally from the line 5-5 of FIG. 4;

FIG. 6 is an enlarged fragmentary view in horizontal section as seen from the line 6--6 of FIG. 4; and

FIG. 7 is a schematic diagram of the electrical circuit utilized to control the supply of electrical energy to the drive motors of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring more particularly to the drawings, FIG. 1 shows a vertical sectional view through a conventional circular grain drying bin indicated generally by the numeral 10. Drying bin 10 includes a circular outer wall 11 supported on a foundation 12. A frusto-conical upper wall or roof l3 overlies the circular outer wall 1 l and a perforate bottom wall 14 is positioned in the bin in upwardly spaced relation to the foundation 12. The perforate bottom wall 14 and adjacent portion of wall 11 serve to define, with the foundation 12, a plenum chamber 15. A conduit 15' leading from a source of heated air under pressure, not shown, communicates with the plenum chamber 15 and introduces heated air through the perforate bottom wall 14 to grain 16 stored within the drying bin 10. Openings 17, 18, formed in the upper wall 13, serve the functions of venting the heated air passing through grain 16 from the bin 10, providing openings for the introduction of grain 16 and permitting visual inspection of the interior of the bin 10.

A screw conveyor 20 is positioned within the plenum chamber 15 and has one end thereof communicating with an opening 21 formed centrally in the perforate bottom wall 14. Screw conveyor 20 leads laterally from the opening 21 to the exterior of the bin and is utilized to remove grain 16 from the interior of the bin 10 when it is so decided. Drying of grain 16 within the drying' bin 10 is normally accomplished by introducing heated air under pressure into the plenum chamber 15, upwardly through the perforate bottom wall 14, the grain 16 and finally out through the opening 17, 18.

In order to avoid the problems heretofor disclosed in the various methods of drying grain and the problems inherent in the prior art devices for stirring such grain, there is provided a grain stirring apparatus hereinafter identified generally by the numeral 30. Stirring apparatus 30 includes a flexible endless conveyor 31 preferably formed from an endless link chain. Support means mounting the conveyor 31 for movements about a circuitous path of travel within the drying bin 10 and for rotation of the circuitous path within the drying bin 10, as will be described in greater detail hereinafter, is indicated generally by the numeral 35. Support means 35 includes a tubular element 36 mounted as at 37, 38 for rotational movements on a vertical axis generally coaxially disposed with respect to the vertical axis of the drying bin 10. A first portion 39 extends radially from the tubular element 36 adjacent the bottom wall 14 of drying bin 10 and terminates at its radially outer end in -a second portion 40. Second portion 40 extends from the first portion 39 in a vertically upward direction, adjacent and parallel to the circular outer wall 11, to a point wherein it terminates adjacent the juncture of the upper wall 13 with the side wall 11. A rigid connecting link 41 connects the upper end of the portion 40 to the upper end of the tubular element 39.

As shown, particularly in FIG. 1, vertically disposed tubular element 36, together with first and second portions 39, 40, cooperate to define a guide track for conveyor 31. Such guide track guides the conveyor 31 in the above circuitous path of travel which lies in a plane that extends radially from the vertical axis to the circular outer wall 11 and generally between the upper and lower walls 13, 14, respectively, of the drying bin 10. As shown, portions 39, 40 are formed to have a generally rectangular C-shaped crosssectional configuration which opens in the direction of rotation of the stirring apparatus 30, indicated by the arrow in FIG. 2, to define a longitudinally extended slot 42. In the present application such direction is shown as being counterclockwise for exemplatory purposes only, it being understood that, by slight modification, such grain drying device 30 may be constructed to operate in either clockwise or counterclockwise directions of rotation. A plurality of paddle-like elements 43 are secured to the conveyor 31, at longitudinally spaced points thereof, in a manner to project laterally therefrom through the slot 42 and travel along such slot 42 during the above-mentioned circuitous movements. The paddle-like elements 43 act to engage and move grain adjacent to the portions 39, 40 in the direction indicated by the arrows shown in FIG. 1. Thus, as the conveyor 31 moves in its circuitous path of travel the grain 16 adjacent the guide portion 39, in the area of the perforate bottom wall 14, is moved radially outwardly toward the circular outer wall 11 and the grain 16 adjacent the guide portion 40 and the circular outer wall 11 is moved vertically upwardly toward the top wall 13. In this manner, it will be seen that rotation of the portions 39, 40 about the axis of the tubular element 36, together with the above-described circuitous movements of the conveyor 31, results in a circulation of the grain 16 within the bin 10 throughout 360 of rotation of the grain stirring device 30 about the vertical axis of the grain drying bin 10. It will be noted that positioning of the portions 39, 40 and conveyor 31 guided thereby, as above described, assures that grain 16 adjacent the bottom wall 14 is adequately circulated or moved in a greater proportion and amount than that grain 16 above it. Thus, grain 16 adjacent the bottom wall 14 is prevented from over-exposure to the heated air forced through the grain 16 from the plenum chamber 15 and consequently damage thereto. In addition, since excessive moisture problems may exist adjacent outer wall 11, positioning of portions 39, 40 and conveyor 31, as described, proportionally increases the circulation of grain 16 immediately adjacent wall 11 relative to grain l6 radially inwardly from portion 40.

To facilitate the movement of the conveyor 31 in its circuitous path of travel, with a minimum of frictional resistance, portion 39 is formed to include a radius 45 at its point of juncture with tubular element 36 and a radius 46 at its point of juncture with portion 40. A radius 47 is likewise formed at the upper end of portion 40. In order to complete a circuitous path of travel con veyor 31 extends from the radius 47 over sprockets 48, 49 carried by the supporting means 35 adjacent the upper end of tubular element 36. Sprocket 49 serves to guide the endless chain of the conveyor 31, together with the paddle-like elements 43, for movement downwardly through the interior of the tubular element 36 wherein same is then guided into movement radially outwardly toward the wall 1 1 over radius 45, along portion 39, over radius 46 and upwardly along portion 40 to radius 47. This arrangement guides the paddle-like elements 43 so they pass downwardly through the interior of the tubular element 36, and do not engage the grain 16. If such engagement were to occur, undue restrictive forces would retard movement of the conveyor 31 downwardly through the grain 16 resulting in undue wear and/or damage to the conveyor 31 or parts associated therewith and the requirement of expensive heavy-duty power means, together with expensive, heavy-duty construction of the supporting structure 35, for imparting such circuitous movements to the conveyor 31.

For the purpose of imparting the above-described circuitous movements to the conveyor 31 an electrically operated gearhead motor 55 is mounted adjacent the upper end of the tubular element 36. A power output shaft 56 of the gear-head motor 55 is rigidly affixed to the sprocket 49 to impart rotation thereto upon energization of the gearhead motor 55 and consequently circuitous movements to the conveyor 31. Sprocket member 48 functions as an idler and is adjustable in a direction to provide the correct amount of tension to the conveyor 31 to assure driving engagement of the sprocket 49 with the conveyor 31.

Independent power means, indicated generally by the numeral 60, for imparting movements to the support means 35 about the vertical axis of the grain drying bin includes an electrically operated gearhead motor 61. As shown, motor 61 is secured to the support means 35 generally at the level of the upper end of the portion 40 adjacent the outer wall 11 of the drying bin 10; A power output shaft 62 has rigidly affixed thereto a grooved drive wheel 63 which rests upon and has driving engagement with a circular track 64. Track 64 extends circumferentially of the drying bin 10 and is affixed to the circular outer wall 11 adjacent the upper wall 13. A generally vertically downwardly spaced roller element 65 is mounted on and carried by the support means 35 in a manner to underlie the circular track 64 and thus maintain the drive wheel 63 in driving engagement with the track 64 at all times during its 360 degrees of travel within the circular drying bin 10.

As seen particularly in FIG. 7 of the drawings, electric motors 55, 61 are adapted to be connected to a source of electrical power, not shown, by means of a plurality of slip rings 70 and a switching mechanism 71. Slip rings 70 are normally mounted within a rectangular housing 73 positioned adjacent to the upper end of the tubular element 36 and adapted to mount and position the slip rings 70 such that the rotary axis thereof is generally coaxial with respect to the rotary axis of the tubular element 36. It will thus be seen that circuitous movements of the conveyor 31, through energization of the gearhead motor 55 and rotational movements of the support means 35, through energization of the motor 61, are caused by closing the switch 71 to supply a flow of electrical energy through the slip rings 70 from the source of power, not shown, to the motors 55, 61.

During grain drying operations of the grain stirring device 30 vertical portion 40, in its circumferential movement, may be excessively deflected from a vertical position by engagement with various obstructions within the drying bin 10 which tend to restrict circumferential movement thereof. By way of example, an obstruction may be catagorized as any material present in the drying bin 10 which would present undue restriction to movement of the support means 35 in its circumferential movement. It will be appreciated that that portion of the support means 35 adjacent the radius 46 may encounter more difficulty in passing through the grain 16 than that portion of guide portion 40 adjacent radius 47 due to the weight or packing of the grain adjacent bottom wall 14. Thus, attempts of the device 30 to move circumferentially within the bin 10 when filled with grain 16 may result in excessive deflection of the lower end of guide portion 40 rearwardly with respect to the upper end thereof and the direction of travel. It will also be appreciated that certain other conditions may cause heavy grain concentration or density at isolated spots and the term obstruction is meant to apply to any and all conditions which may be present to unduly restrict movement of portions 39 or 40 so as to excessively deflectguide portion 40 in an amount to 7 cause damage to stirring device 30.

For the purpose of protecting against damage to the stirring device during the occurrence of such deflection, for example a deflection of more than 5 degrees, means is provided for disabling the gearhead motor 61 until the guide portion 40 returns to a lesser degree of deflection (a deflection of less than 5). Such means includes a mercury switch 75 mounted on the upper end of the support means adjacent the upper end of the guide portion 40. A mounting bracket 76 is adapted to adjustably mount the mercury switch 75 so as to sense a desired degree of deflection of the portion 40. For the present example the above noted deflection of more than 5 of the guide portion will position the switch 75 to-terminate the supply of electrical energy to the gearhead motor 61 and thus terminate movement of the portions 39 and 40 circumferentially of the drying bin 10. Since the supply of electrical energy to only one of the gearhead motors 61 has been terminated, motor 55 continues to operate and impart movement to the conveyor 31 along its circuitous path of travel.

Normally obstructions, such as grain 16, within the container 10 engaging the upper end of the portion 40 i does not usually deflect such portion a sufflcient degree to cause the motor 61 to become disabled, but merely causes slippage between the drive wheel 63 and circular track 64 until such obstruction or grain 16 has been moved from the path of travel of conveyor 31 by the paddle-like elements 43. However, should the obstruction be positioned at a lower elevation so as to be engaged at a lower elevation on the guide portion 40 or by the guide portion 39, deflection of the guide portion 40 from the vertical could occur and the mercury switch would move to a position wherein the motor 61 would be deenergized to terminate movement of the portion 40 circumferentially of the bin 10. Since the conveyor 31 would continue to move in its circuitous path of travel, paddle-like elements 43 would continue to engage the material restricting the movements of guide portion 40 circumferentially of the bin 10 until the guide portion 40 would again return to its normal position of less than 5. Upon removal of the restriction switch 75 would again be positioned to energize the motor 61 and movement of the guide portion 40 circumferentially of the storage bin 10 would resume. It will be appreciated that such a start-stop cycle of circumferential movement may occur many times as the conveyor 31 and supporting structure thereof moves circumferentially of the bin 10, resulting in a walkingtype motion of the stirring apparatus 30. Such a disabling device as the mercury switch 75 obviously prevents any excessive twisting of the supporting structure 35 during the above-described deflection which could well result in damage thereto and consequently inoperativeness of the stirring mechanism 30. By reference to the foregoing description it will be seen that a grain stirring apparatus has been provided which is extremely simplified in construction, thus requiring little or no maintenance through extended periods of operation. In addition, a grain stirringapparatus has been provided which overcomes the inherent problems present in prior art grain stirring devices now manufactured so as to more efficiently reduce the drying time and expense of such grain drying operations.

While a specific embodiment of a grain stirring apparatus is illustrated and described, it should be understood that further modifications and improvements will occur to those skilled in the art. I desire it to be understood, therefore, that this invention is not limited to the particular structure shown and intend in the appended claims to cover all modifications which do no depart from the spirit and scope of this invention.

What is claimed is:

1. Grain stirring apparatus for use in a grain drying bin having a circular outer wall, a top wall and a bottom wall, said grain stirring apparatus comprising:

a. a flexible endless conveyor;

b. support means mounting said conveyor for movement about a circuitous path and for rotation of the circuitous path within said said drying bin; and

c. power means for providing said circuitous movement and said rotational movement upon proper energization thereof.

2. Grain stirring apparatus for use in a grain drying bin having a circular outer wall, a top wall and a bottom wall, said grain stirring apparatus comprising:

a. a flexible endless conveyor;

b. support means for said conveyor;

0. said flexible endless conveyor being mounted on said support means for movements in a circuitous path of travel;

d. means mounting said support means for rotation on a vertical axis generally parallel to the vertical axis of the grain drying bin;

e. power means operatively mounted to impart said circuitous movements to said conveyor; and

f. independent power means for imparting said rotational movement to said support means.

3. The structure of claim 2 in which said circuitous path of travel lies in a plane which generally extends radially from the vertical axis to the circular outer wall generally between the upper and lower wall of the grain drying bin.

4. The structure of claim 2 in which said support means mounting said conveyor for movements in a circuitous path includes:

a. a vertically disposed tubular element;

b. a first guide portion extending radially from said tubular element mounting said flexible conveyor for movements generally radially outwardly adjacent the bottom wall of the grain drying bin; and

c. a second guide portion extending vertically from the radially outer end of said first portion and mounting said conveyor for movements vertically upwardly adjacent the circular outer wall of said grain drying bin.

5. The structure of claim 4 in further combination with means for disabling said independent power means responsive to deflection of said second portion of said support means adjacent said circular outer wall a given amount of degrees from the vertical during circumferential movement of said portion relative to said circular outer wall.

6. The structure of claim 5 in which said independent power means includes an electrically operated motor and in which said means for disabling said independent power means is a mercury switch adjustably mounted on said second portion of said support means adjacent the u per end thereof, said mercury switch being moun ed to terminate the supply of electrical energy to said electrically operated motor responsive to deflection of said second portion of said support means a given amount of degrees from the vertical during said circumferential movement of said second portion.

7. The structure of claim 2 in which said tubular element defines the vertical axis of rotation of said support means and is coaxially disposed with respect to the vertical axis of the grain drying bin.

Claims (7)

1. Grain stirring apparatus for use in a grain drying bin having a circular outer wall, a top wall and a bottom wall, said grain stirring apparatus comprising: a. a flexible endless conveyor; b. support means mounting said conveyor for movement about a circuitous path and for rotation of the circuitous path within said said drying bin; and c. power means for providing said circuitous movement and said rotational movement upon proper energization thereof.

2. Grain stirring apparatus for use in a grain drying bin having a circular outer wall, a top wall and a bottom wall, said grain stirring apparatus comprising: a. a flexible endless conveyor; b. support means for said conveyor; c. said flexible endless conveyor being mounted on said support means for movements in a circuitous path of travel; d. means mounting said support means for rotation on a vertical axis generally parallel to the vertical axis of the grain drying bin; e. power means operatively mounted to impart said circuitous movements to said conveyor; and f. independent power means for imparting said rotational movement to said support means.

3. The structure of claim 2 in which said circuitous path of travel lies in a plane which generally extends radially from the vertical axis to the circular outer wall generally between the upper and lower wall of the grain drying bin.

4. The structure of claim 2 in which said support means mounting said conveyor for movements in a circuitous path includes: a. a vertically disposed tubular element; b. a first guide portion extending radially from said tubular element mounting said flexible conveyor for movements generally radially outwardly adjacent the bottom wall of the grain drying bin; and c. a second guide portion extending vertically from the radially outer end of said first portion and mounting said conveyor for movements vertically upwardly adjacent the circular outer wall of said grain drying bin.

5. The structure of claim 4 in further combination with means for disabling said independent power means responsive to deflection of said second portion of said support means adjacent said circular outer wall a given amount of degrees from the vertical during circumferential movement of said portion relative to said circular outer wall.

6. The structure of claim 5 in which said independent power means includes an electrically operated motor and in which said means for disabling said independent power means is a mercury switch adjustably mounted on said second portion of said support means adjacent the upper end thereof, said mercury switch being mounted to terminate the supply of electrical energy to said electrically operated motor responsive to deflection of said second portion of said support means a given amount of degrees from the vertical during said circumferential movement of said second portion.

7. The structure of claim 2 in which said tubular element defines the vertical axis of rotation of said support means and is coaxially disposed with respect to the vertical axis of the grain drying bin.

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