US2680324A - Dusting machine - Google Patents

Description

June 8, 1954 M. H. TUFT 2,680,324

DUSTING MACHINE Filed Dec. 16. 1949 2 Sheets-Sheet l M/(ES H. TUFT,

HGENT June 8, 1954 U FT 2,680,324

DUSTING MACHINE 2 Sheets-Sheet 2 an-"b22212: m

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IN VEN TOR.

. V I Ewan 5% Patented June 8, 1954 DUSTING MACHINE Miles H. Tuft, Huntington Park, Calif., assignor to Hardie Manufacturing Company, Hudson,

Mich., a corporation of Michigan Application December 16, 1949, Serial'No. 133,331

6 Claims 1 This invention relates to agricultural machinery and more particularly relates to machinery for spreading dusts or powders, such as insecticides, upon crops or orchards.

It is an object of this invention to provide a dusting machine capable of spreading crop-dusting powders laterally and vertically so as to cover a wide area and a considerableheight.

A further object of the invention is to provide a dusting machine having simple and easily adjusted means for controlling and directing the spread of dusting powders in desired areas and directions.

Another object of the invention is to provide a dusting machine which is relatively free from clogging or packing and which is highly efiioient in maintaining the dust in a fiuid condition and in discharging the dust in a finely comminuted cloud of even distribution and density.

Still another object of the invention is to provide a dusting machine in which control of the volume of dust distributed in a given unit of time or of area is easily effected, with resultant control of the density of the dust cloud.

Other objects and advantages of the invention will be pointed out as the following description of a preferred embodiment of the invention proceeds, or will be apparent from that description and from consideration of the accompanying drawings illustrative of that embodiment, in which:

Figure 1 is a side elevational view of my improved dusting machine;

Figure 2 is a plan view from above;

Figure 3 is a vertical sectional view taken on the plane of section 3-'3 of Figure 2;

Figure 4 is a transverse vertical sectional view of the blower, or dust distributor, taken on the plane of section 4-4 of Figure 1, and illustrating the system of distributing valves;

Figure 5 is a sectional view through the volume control mechanism, taken on the plane of section 5-5 of Figure 3;

Figure 6 is another sectional view through the volume'control mechanism, taken substantially at right angle to the view of Figure 5, as indicated by the line 6-5 of Figure 3;

Figure '7 is a fragmentary sectional view of a portion of the distributing valve system shown in Figure 4, and illustrating changes in the valve settings and housing which may be effected to control the direction of the dust cloud; and

Figure 8 is a fragmentary perspective view illustrating means for locking the distributing valve system in desired positions.

- prises a hopper H and It is to be understood that my dusting machine will ordinarily be supported on a tractor or trailer and will derive power from the automotive source. For clarity of illustration, the dusting machine only has been shown in the drawings, with as much of the securing framework and power transmission mechanism as will illustrate the method of operation.

Having reference now to the details of the drawings, my improved dusting machine coma blower l2 supported on suitable framework [3, and connected by a conduit l4, through which dust stored in the hopper may be delivered to the blower for distribution. Within the hopper I! is an upwardly extending cylindrical housing I5 containing a screw-conveyer It. The housing I5 is open at both its lower end I? and upper end Hi to permit dust in the hopper to enter below and to be conveyed upwardly, there to spill over the upper end 18 in constant recirculation if not otherwise routed and used as hereinafter described. The lid l9 of'the hopper is removable-to fill the hopper, and a gate 29 operated by a lever 2! is provided for dumping unused powders. The housing l5 may be held erect within the hopper by suitable braces 22.

Near the upper end of the conveyor housing l5 is a port which is preferably elongated along the elemental lines of the cylindrical housing so as to have greater vertical than horizontal dimensions. A valve housing 26, containing mecha' nism for opening and closing the port extends from the conveyor housing l5 outwardly to the wall of the hopper l l where it opens to the atmosphere, preferably inclining upwardly to prevent dust from flowing therethrough to the open end 21. The inner end 28 of the valve housing is cut away to provide an opening 29 encompassing the port 25 and marginally fitting against the conveyor housing l5, and may be held secured to the conveyor housing by a clamp 30 (see Figure 5). Just below the port 25, the lower wall of the valve housing 26 has an opening 3i communicating with the upper end of the conduit I4, which may there be welded to the valve housing. It will be obvious that dust raised by the screw conveyor It to the level of the port 25 will pour through the port when the latter is open and will find its way by gravity through the opening 3| into the conduit l4.

To control the opening of the port 25, a valve plate 33 is mounted pivotally upon a lever 34 which extends outwardly through the valve housing 26 and has a ring or handle 35 in its outer end by which it may be manipulated. The valve plate 33 is curved to be concentric with and to conform to the exterior of the conveyor housing it, so that it may slide thereon in any direction and still maintain close contact therewith. As it is necessary for such sliding motion that the valve plate be maintained oriented with respect to the conveyor housing rather than with respect to the lever 3A, the valve plate is connected to the lever by a swivel stud 36. The stud 35 may turn freely in the lever and also, by virtue of its head 3'! being engaged loosely in a chamfered recess 38, it permits the lever to assume a variety of angles of tangency to the valve plate. Thus, in effect, the valve plate may slide around the conveyor housing it, as well as up and down thereon while the lever moves in one plane, and alternatively the plane of movement of the lever may be changed to some extent without affecting. movement of the valve plate.

The lever 34 preferably has some lateral resiliency, for example being made of a relatively thin piece of strip steel, and is mounted intermediately of its ends on a fulcrum pin 5 5}. The pin 40 extends across the valve housing 25 and is sufficiently long to permit the thin lever to have some lateral play axially. A sleeve 4!, carried by the pin 48 between the pin head &2 and the lever, and extending slidably through the wall of the valve housing, reduces the extent of lateral play, and may be brought to press against the lever by adjusting a nut 43 in a tightening direction. The lever may thus be moved laterally until its outer end is pressed against the outer end 2? of the valve housing 26 and the valve plate 33 carried by the inner end of the lever is pressed against the conveyor housing [5. tightening of the nut l3 will place the lever under resilient tension. The pressure of the valve plate 33 upon the conveyor housing may thus be adjusted.

The'blower 12 comprises a casing 45 in which is mounted a centrifugal impeller or fan as. The casing 45 has side walls ll, both of which are preferably disk-shaped, having central portions 48 spaced apart to accommodate the impeller and the hereinafter described air-passages and marginal portions dfi more narrowly spaced to Further provide high-velocity outlets from the air-passages. Suitable openings '51; in the central wall portions G3 permit the shaft 51 of the impeller to extend therethrough and provide for the intake of air. The shaft 51 is journalled at both its ends in journal boxes 52, one of which is at the outer end of a shaft housing 53 into which the lower end of the conduit i i discharges. A small auxiliary fan 54 is mounted on the shaft 5| substantially at the lower end of the conduit hi. Dust from the conduit thus enters the shaft housing .53, as shown in Figure 3, to be drawn along the shaft 5! to the center of the impeller as, there to be mixed with air and impelled centrifuge-11y.

Beginning at the periphery of the zone oi movement of the impeller -5, a plurality of baiiies 55 extend outwardly between the side walls 4? to define outwardly and upwardly extending air passages 56a, 55b, etc., which may be interspersed with dead air spaces as shown at 5? in Figure The baffles 55 are preferably welded to the side walls 51, and except where they enclose a space not intended for the passage of air, they preferably terminate outwardly at theperiphery of the more widely spaced wall portions it. As herein illustrated, the number or" air passages is eight, but more or less may be provided, and it will be ations that might afiect the distribution of dust. However, as the air passages lead outwardly they become narrower, in order to increase or at least maintain the velocity of the air. This necessitates the formation of the dead spaces 5"! between the'air passages, which may be provid d by joining two baflles 55 at their inner ends and permitting them to diverge outwardly.

- As the embodiment of the invention herein illustrated is intended for dusting trees and high crops and not for dusting the ground over which it is transported, no provision is made for downwardly directed air-passages, and the bottom of the casing 35 is closed by a wall 58. Consequently, it becomes desirable to provide means for preventing accumulation and calzing of dust in the lower quarter-periphery of the blower, particularly in that zone in which the fan. is driving the dust downwardly against the imperforate wall 58. The entrance area of air-passages in this zone, specifically passages 56g and 5%, may therefore be subdivided by short baiiies 55a to provide a plurality of narrow passages inv which the air velocity is high and which assist-each other by aspiration or induced draft to clear dust that may begin to accumulate in any one of them.

When the dusting machine is used to dust the outer side of the outer row of an orchard, there is no need for bilateral distribution of dust. A permanent exterior end wall 59 may be disposed between the outer casing walls 455. at one side of the casing, cutting off the lateral flow of air. The space 69 bounded outwardly by the Wallis and by a bafiie 55b dividing it from air passage 5%, may be a temporary dead air space, as shown in Figure 4, or may be converted into an upwardly directed air-passage as shown in Figure 7-. When the space as is to be used as an air passage, a temporary exterior walltl may be placed between the margins of the side walls 5'5, in extension of the permanent wall 59 to .the bottomwall. 58.

,Air valve plates 64 are swingably mountedbetween the outer side walls as at the outer. ends of the passages 5t and form extension outlets for the passages 56. By varying the positions of the plates e4, the extension outlets may be varied as to both direction and cross-sectional area, or may be closed. As the majority of the passages 56 have dead air spaces 5']. interspersedbetween them, the plates. 64 will. ordinarily .be. arranged in pairs of individual.platesrespective: to .each air passage. Where, howeveig'two passages adjoin without an intervening dead space, the plates forming the dividing extension outlet wall may be joined, as at Ma. Wherethe air passage wall extends to the periphery of the casing i5, as do the bottom wall 58 and the permanent end wall 58, the valve plates may be mounted adjacent the outer margins of the wall portions to, as shown at 54b, and may swing inwardly.

To permit the air valve platesfie to swing and to be easily removed, interchanged, and exchanged, the platesare .constructedwithopen hinge-bends 65 and are mounted .on ordinary bolts 66 which extend through the side walls 41. The side walls 4'! are not entirely rigid, but are made of material such as sheet iron, capable of yielding resiliently to pressure. The central portions 48 are, of course, held spaced by the baifies 56, welded thereto, so as not to collapse upon and interfere with theimpeller 6B, but the outer portions 49 are for the most part unsupported laterally and may be pressed toward one another by tightening nuts 6? on the bolts 66. Thus the valve plates 64 may be clamped in any desired position by simply tightening the nuts 6.1. As added means for clamping the valve plates clamps 68 are provided, which will be found particularly effective when used on the margins of the outer wall portions 49 in proximity to permanent spacing elements such as the bottom wall 58 or end wall 59.

To drive the dusting machine, power may be taken from power trail-emitting mechanism ill of the tractor or other prime mover, and transmitted through a shaft ll provided with end universal joints 72 to a pulley shaft l3 which may extend rearwardly through the blower through one of the dead air spaces 51. A pulley M, preferably of V-type, on the shaft 73, drives a pulley E5 on the impeller shaft 5! by belts 6, an idler pulley 77 being interposed if desired. From the impeller shaft 5|, power is taken by a belt 18 to a jack shaft 19 from which it is transmitted by a belt 8!) to a pulley 81 on the lower end of shaft 82 of the screw conveyor [6. It will be observed that this drive system is a unit for the impeller 46 and screw conveyor l6 and drives both of them at a constant speed ratio.

In operation of my improved dusting machine the operator determines from the nature of the work to be performed the desired directional setting of the dust jets which will emanate from the blower, the desired velocity of the jets in order to reach distant points such as tree tops, and the desired dust-concentration in the jets. If, for example, the operator desires to proceed between two rows of trees, dusting both rows si- 7 multaneously, he may set the valve plates as shown in Figure 4 andclamp theminthat position by tightening nuts El and clamps 68. It will be seen from Figure 4, that air passages 56a and 5622 are open to dust lower foliage to the left of the blower, the upward extension of 561) and the optional space 69 being closed; air passages 56c and 5611 will throw dust toward the upper left; air passages 56c and 56 will throw dust to the upper right; and lower foliage to the right will be dusted from air pasages 56g and 55h. If only trees to the right of the blower were to be dusted, the operator might leave the air valve plates of passages 55a 56], 569 and 5th in the aforesaid positions and turn the valve plates controlling the outlets of passages 56d, 56c, the upward branch of 56b and the space it also the right. The valve plate controlling the lower entrance to the space 60 may be removed, and the immediately lower valve plates be raised to close the lower branch of passage 5% and to fully open passage 56a. By temporary insertion of the temporary end wall 6| the passage 56a is made continuous with the space 60, to discharge upwardly and to the right.

When the various valve plates are being set for direction, they are also set to provide more or less throttle to the outlets which they control. If all the outlets are throttled to substantially like degree, the jets emanating therefrom will be substantially alike in velocity and volume and in dust-concentration,--that is, the ratio of dust to air in each jet-because the inlet areas of the air passages, the air-dust mixture at the inlet, and the pressure at the inlets is substantially alike. But an increase of throttle applied to one outlet with respect to others will cause a back pressure in that outlet which will decrease the volume of air-dust mixture through the particular air-passage and consequently reduce the quantity of dust discharged by that outlet.

Variation of the degree of opening of the port 25 by the setting of the valve plate 33 controls the total amount of dust delivered to the blower. It will be understood that the conveyor IE will, even at slow speeds, lift more dust past the port 25 than the port can pass at full opening.

It is. not necessary to vary the speed of operation in order to vary the total amount of dust distributed or to maintain a constant speed of operation in order to maintain a constant volume of dust, as the lever 3t may be readily moved by the operator in accordance with momentary requirements. When some of the outlets from the blower are inactivated by closure, the volume of air emanating individually from the remaining outlets will be increased, but the volume of dust emanating individually from these remaining outlets may be maintained constant by throttling the port 25. This step reduces the concentration of the air-dust mixture, but if, for example, the outlets remaining open are all directed to one side of the machine, it allows the total amount of dust thrown in that direction to remain constant.

During all of the above-described conditions of operation, the small auxiliary fan 54 will operate to create a partial vacuum in the conduit I4 and to draw whatever dust may enter the conduit H! to the blower. The valve plates 64 may be so throttled as to prevent any discharge of dust, yet the fan 54 will prevent clogging in the conduit [4, drawing air through the valvehousing 26 and discharging through the opposite air-intake opening 50 if no other outlet is available. When any of the valve plates 64 are open, the conflict between air drawn through the opening 50 by the fan and air drawn through the conduit M by the fan 54 creates a great turbulence and thoroughly mixes the dust with the air.

Obviously, many changes and modifications in the arrangement and construction of my improved dusting machine are possible within the scope and spirit of the invention; therefore, I do not wish to be limited to the precise embodiment herein described and illustrated, but only to the scope of the appended claims.

I claim:

1. In a dusting machine: a hopper for holding dust to be distributed by said machine; a

blower; an upwardly extending screw conveyor in said hopper, having a cylindrical housing open at its upper end and adapted to circulate dust upwardly through said housing for return by gravity to the lower portion of said hopper; there being a port in the upper portion of said housing; a conduit into which said port opens, leading to said blower; a curved plate concentric with said housing slidable on said housing to close said port; a lever on which said plate is pivotally mounted for moving said plate with respect to said port; and means acting on said lever to hold said plate in contact with said housmg.

2. In a dusting machine having a hopper, a conduit leading from said hopper, and cylindrically housed conveyor means for moving dust from saidhopper to saidconduit: there being a .port in the housing of said conveyor,-elongated in the direction of the longitudinalaxis of said housing and communicating with saidconduit;

a lever arranged to swing in a plane parallel to the longitudinal axis of said housing; a curved .plateconcentric with said housing and pivotally connected 130 0118 end of said lever andadapted to be moved thereby slidingly on the exterior ofsaid housing to close said port; a fulcrum for said lever intermediate its ends on which said lever is transverselymovable; means at the-end of said lever opposite to said plate limit- .ing transverse movement of said lever; and tensioning means urging the plate end of saidlever transversely toward said housing-,whereby said housing; a curved plate concentric with' said housing and pivotally connectedto .one end of said lever and adapted to be: moved thereby slidingly-on the exterior of said housing to close said port; a fulcrum for said lever intermediate its ends on which said lever is transversely movable; means at the end of said lever opposite to said plate limiting transverse movement. ofsaid lever; and tensioningi-means urging the plate end of said lever transversely toward said housing,-whereby said-lever is moved laterally-to maintain said plate in tensioned contact with said housing.

4. In a dusting machine: apparatus asset forth in claim 3, in which saidlever is of resilient material and bendable laterally ,.and said tensioning means is adapted to bend said leveragainst-the resistance of said housing and said limiting means.

5. In a dusting machine, the combination of: a'hopper for holding dust to be distributed by said-machine; a main fan, ahousing therefor,

and adrive-shaft on which said fan is mounted, the fan and housing arranged to receive. dust centrally adjacent said shaft and to discharge said dust centrifugally, said housing havingan opening for the admission of carrier air adjacent to said shaft at one side of said .main fan; a conduit arranged to conduct dustby gravity from said hopper and communicating with said housing adjacent said shaft and at the other side of said main fan; and an auxiliary fan mounted on said shaft adjacent the discharge end of said conduit and arranged to propel dust received from said conduit longitudinally of said shaft toward said opening.

6. In a dusting machine, the combination of a hopper for holding dust to be distributed by said machine; a main fan, a housing therefor, and a drive-shaft on which said fan is rounded, the fan and housing arranged to receivedust .centrally adjacent said shaft and to discharge said dust centrifugally, said housing having an opening for the admission of carrier airadjacent said shaft at one side of said main fan; a conduit for dust having one of its ends in communication with said hopper and with the atmosphere, and having its other end in communication with said housing adjacent said shaft and at the other side of said main fan; and .an auxiliary fan mounted on said shaft adjacent the discharge end of said conduit and arranged to propel dust received from said conduit longitudinally of said shaft toward said opening,.said auxiliary fan being so housed as to receive carrier air substantially only through said conduit.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 572,383 Smith Dec. 1, 1896 963,277 Clifiord July 5, 1910 1,551,877 Henning Sept. 1,1925 1,987,656 Althouse Jan. 15, 1935 2,206,876 Chater July 9,1940 2,253,802 Ness et al. Aug. 26, 1941 2,310,620 Dye Feb. 9, 1943 2,545,829 Spreng Mar-20, 1951

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