US2715792A - Power control for aerial crop dusting - Google Patents

Description

Aug. 23, 1955 P. J. MAGNUSSON POWER CONTROL FOR AERIAL CROP DUSTING 2 Sheets-Sheet 1 Filed June 5 1951 Aug. 23, 1955 P. J. MAGNUSSON 2,715,792

POWER CONTROL FOR AERIAL CROP DUSTING Filed June 5, 1951 2 Sheets-Sheet 2 Q0 43 1.9 M A Per 33 Moan usson \NVENTOa 1 QaMMQMdMMdR -Q.Lo vrrvg United States Patent POWER CONTROL FOR AERIAL CROP DUSTING Per John Magnusson, Uppsala, Sweden Application June 5, 1951, Serial No. 229,934

Claims priority, application Sweden July 15, 1950 I 3 Claims. (Cl. 43-147) The present invention relates to a manual control device for controlling the flow rate of an insecticidal powder when dusting crops from a low flying aircraft, the powder delivery control being associated with the aircraft throttle control handle to permit simultaneous manipulation by the pilot of both the throttle and powder control while if L using only one of his hands to obtain independent control of both the aircraft engine speed and of the rate of powder delivery. This leaves the other hand of the pilot completely free for the manipulation of other controls.

Means for powder-ing or dusting growing crops from aeroplanes for protection against noxious insects are known. Such means generally consist of one or more containers for the powder, said container being placed inside or outside the aeroplane, the powder being fed from said container to a spreader or nozzle.

For feeding the powder it is known to use mechanical feeding means, for instance a screw conveyor, or aerodynamical feeding means, which by means of the airstream produce a vacuum at the discharge opening of the container, whereby the powder is exhausted from the container.

The powdering from aeroplanes must take place from a very low height, viz. a height below power-lines and the like. -It is evident that the pilot under such circumstances must concentrate his entire attention on the manoeuvring of the aeroplane.

This requires the pilot, while flying at such low altitudes, to keep one hand continuously on the throttle for effecting frequent changes in engine speed and to keep the other hand free for the manipulation of other controls. Moreover, it is necessary to control the flow rate of the insecticide and to start and stop the flow when entering and leaving the area being dusted. Unless the powder flow is carefully controlled, insecticidal powder will be wasted or the desired area will be only partially dusted,

or both.

Generally, the present invention provides means for controlling the flow of the insecticidal powder, this control means being so combined with the throttle lever that the pilot can control the flow of powder without removing his hand from the control handle of the throttle lever.

An embodiment of the invention is illustrated in the accompanying drawings.

Referring to the drawing:

Figure 1 is an elevational view of a powder reservoir and spreader, partly broken away to illustrate details of construction.

Figure 2 is a plan sectional view of the reservoir and spreader taken along the line II-II of Fig. 1.

Figure 3 is a front elevational view of a throttle handle embodying the invention, the handle being shown partly in section and being adapted for manipulation by the left hand of a pilot.

Figure 4 is a left end view of the handle shown in Fig. 3.

Figure 5 is a right end view of the handle shown in Fig. 3.

2,715,792 Patented Aug. 23, 1955 In the drawings 1 designates a powder container provided with two discharge duets 2 leading to aerodynamic spreader 3.

Said spreader 3 is constructed according to the venturi tube principle. A straight wall 4 defines the upper part of a channel 5, the bottom of which consists of the upper part of a wing-profiled surface 6, whereas the side walls of the channel consist of plane surfaces 7.

The uppermost part of said surface 6 is situated beneath said discharge ducts 2, at the throat of the venturi tube, a vacuum thus being produced below said ducts 2, when in flight causing the powder to be withdrawn from the container 1.

The discharge duets 2 are provided with butterfly valves .3 3, which are pivotably mounted on a horizontal shaft 9.

Said shaft is provided with a lever (not shown) which can be actuated by means of a bowden wire 10 (Figs. 4 and 5) for opening and closing the butterfly valves 8.

In Fig. 3, 11 designates the throttle lever of the aircraft, on which is rotatably mounted a butterfly valve control lever 12, to which the bowden wire 10 is fixed. On the valve control lever 12 a hollow cylindrical sleeve 13 is fixed by welding, the sleeve 13 forming the handle or operating member for the throttle lever 11 as well as being rotatable about its own axis for control of the but tertly valves 8. Around the cylindrical handle or sleeve 13 is disposed a length of rubber tubing 14 for obtaining a better grip of the handle 13. The throttle lever 11 is operated by displacing the handle 13 in the direction of flight which is laterally to the left or right as viewed in either, Fig. 4 or 5, whereas the flap valves 8 are operated by rotating the handle 13 about its own longitudinal axis.

The valve control lever 12 is provided with a circular lower portion concentric with the longitudinal axis of the cylindrical handle .13. The upper portion of valve control lever 12 moves between the position shown in full lines and the position shown in dotted lines in Figs. 4 and 5. At its outer or upper end, the valve control lever 12 is bent back to provide an inverted U-shaped portion, and a transversely extending radial slot is formed therein, the slot extending across the entire closed end portion of the inverted U. The legs of the inverted U partially embrace the movable element of the bowden wire 10 and a transverse pin fixed to the movable element of the bowden wire 19 is received in the radial slot, as shown in Figs. 3, 4 and 5.

A plunger 15 extends through the center of the hollow cylindrical handle 13 and is axially movable therein. At its left end, as viewed in Fig. 3, the plunger 15 carries a yoke member 16. The yoke member 16, in turn, carries a pair of pins 17 which extend freely longitudinally movably through suitable apertures in throttle lever 11 to engage diametrically opposed locking holes 18 formed in valve control lever 12 near the periphery of its circular portion. For simplicity of illustration, only one locking hole 18 of each of two pairs of holes has been shown in Figs. 4 and 5 of the drawing, and these serve to lock the valve control lever either in the position shown in solid lines or in the position shown in dotted lines. The plunger 15 is freely slidable through throttle lever 12 and valve control lever 13, but is prevented from rotating with respect to throttle lever 11 by lateral engagement between the pins 17 of yoke member 16 and the sides of the apertures in throttle lever 11 through which these pins pass slidably. As shown in Figs. 3 and 4, the valve control lever may be locked in either the position shown in full lines or in the position shown in dotted lines.

The plunger 15 carries a collar 19 intermediate its ends. A helical compression spring 20 is wound around the left portion of plunger 15 and bears against collar 19, yieldingly urging plunger 15 to the right as viewed in Fig. 3. At its right hand end, the plunger 15 is provided with a push button 21. Pressure on button 21 unlocks valve control lever .12 by disengaging pins 17 from the locking holes 18 and thus permits rotation of handle 13 about its own axis to open or close the butterfly valves 8 by means of bowdenrwire 10. Movement of handle 13 to vary the engine speed flexes the bowden wire 10, but does not produce relative rotary movement between handle 13 and throttle lever 11. When pins 17 are engaged in locking holes 18, such movement is positively prevented.

I The operation of the device above described is as follows;

During flight the pilot has his left hand on the handle 13, 14 and controls the throttle lever by displacing it forwards and backwards in the direction of flight. Thus, the pilot is able to control the butterfly valves 8 with the same hand, as the throttle lever, by at first pushing the bottom 21, thereby releasing the locking means 16, 17, 18 against the action of the spring 20, whereupon the handle 13, 14 is turned, whereby by means of the lever 12 and the bowden wire 10 the position of the flap valves can be regulated.

i The invention is not limited to the embodiment now described, but can be modified in several ways within the scope of the invention.

Having now particularly described the nature of my invention and the manner of its operation what I claim 1. A control device for crop dusting apparatus of the class described, comprising: a powder reservoir adapted to be carried by an engine driven aircraft; spreading means disposed in the airstream of said aircraft while in flight, said spreading means being connected to said reserv'oir to receive powder therefrom; a throttle lever adapted to control the engine speed of said aircraft; a handle member for manually displacing said throttle lever, said handle member being secured to said throttle lever for rotation with respect thereto; valve means controlling the flow of powder from said reservoir to said spreading means; and valve control means coupled to said handle 3 4 member and said valve means, said valve control means causing said valve means to change the flow rate of said powder from said reservoir to said spreading means in response to rotation of said handle member with respect to said throttle lever, whereby the pilot of said aircraft varies both the engine speed thereof and controls the spreading of said powder by the use of a single hand.

2. A control device according to claim 1, further comprising manually releasable locking means'carried by said throttle lever and acting on said valve control means for holding said valve means locked to provide a fixed flow rate for said powder. 1

3. A control device aceording to claim 2, which said handle member is of hollow cylindrical configuration and is rotatable about its own axiswith respect to I Q a 7 said throttle lever, and wherein said locking means com- 1 prises a manually operable spring pressed plunger axially displaceably disposed within said handle member, a valve control lever having a locking hole formed therein, said valve control lever forming a part of said valve control means, said valve control lever being pivotally mounted on said throttle lever and adjacent to said throttle lever for pivotal movement about the axisof said. handle memher and being secured to said handle member for rotary movement therewith; and movable locking pin means car ried by said throttle lever and engaging saidlocking-hole for preventing said pivotal movement, said locking .pin means being connected to said plunger for disengagement from said locking hole in response to manual pressure on said plunger sufiicient to overcome said spring pressure and withdraw said pin means from said locking hole.

References Cited in the file of this patent UNITED, STATES PATENTS Great Britain Dec. 4, 1940

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