Drift free spraying apparatus

A towable spraying device for attachment to a tractor, truck, or the like, for drift free spraying of chemicals such as herbicides and pesticides in a confined area in any wind condition. An elongated surface engaging spray housing is provided for attachment to a towing vehicle and includes an inner tubular member having a plurality of nozzles thereon for dispensing spray therefrom between fore and aft, elongated flexible baffles constructed upon the housing. The flexible baffles comprise lower portions of the fore and aft wall sections of the housing which permit same to engage and glide over rough terrain while substantially confining the spray therein. Spray such as insecticides can therein be applied to foliage and other ground surfaces in a controlled manner wherein extraneous contamination must be prevented.

BACKGROUND OF THE INVENTION 
The invention relates to an apparatus for spraying chemicals, and, more 
particularly, to a herbicide spraying unit adapted for towable attachment 
to a tractor to facilitate drift free spraying. 
It is generally the practice when spraying chemicals such as herbicides and 
insecticides to eject the chemical in a fine mist upon the foliage being 
treated. Oftentimes however, winds cause the mist to drift away from the 
subject foliage before same is contacted. This creates two problems. 
First, the purpose of the spraying is frustrated in that the subject 
foliage is not treated. Secondly, the drift of the spray often contacts 
areas which are detrimentally affected by the spray. This twofold problem 
has been addressed by certain prior art spraying devices which have 
provided "focusing" spray nozzles which intensify the spray stream to 
reduce drift contamination. However, such devices generally alter the mist 
characteristics of the chemical and reduce the treatment effectiveness 
thereof. 
Other prior art approaches to reducing spray contamination caused by drift 
have included spray bars designed for use very close to the sprayed 
surface whereby the spray pressure can be substantially reduced. Such an 
effect reduces mist drift but also reduces the rate at which the chemical 
can be applied as well as the mist characteristics. Furthermore, nozzle 
modifications for controlling mist drift are generally inconsistent with 
optimal spraying configurations from a technical standpoint. 
It would be an advantage therefore to provide spraying apparatus which 
could incorporate optimal spray nozzle configurations in an assembly 
providing confined spray application and the elimination of drift 
contamination. The invention of the present system is constructed for just 
such a purpose. The spray bar is enclosed in an elongated housing adapted 
for ambulatory surface engagement. The housing includes flexibly mounted 
fore and aft walls for conforming to uneven surfaces over which the 
housing is permitted to glide. The spray from the spray bar is confined 
therein during all wind conditions. 
SUMMARY OF THE INVENTION 
The invention relates to apparatus for towable ambulation behind a vehicle 
to effect confined spraying of underlying foliage. More particularly, one 
aspect of the invention includes an improved spraying apparatus of the 
type adapted for ambulation in connection with a vehicle and having a 
spray bar mounted in communication with a fluid pump and reservoir 
assembly adapted for emitting fluid in a mist configuration upon the 
surface to be sprayed through nozzles provided in the spray bar. The 
improvement in the spraying apparatus comprises an elongated housing 
having fore and aft walls adjacent first and second end walls and 
including the spray bar mounted therein for confined spraying therefrom. 
The housing includes a top wall interconnecting the fore, aft and side 
walls and is opposite an open lower portion adapted for abutting the 
surface to be sprayed. The fore and aft walls each include an elongated 
section flexibly mounted to the walls and adapted for abutting engagement 
with the surface to be sprayed and conformation with nonplanar areas 
thereof for confining spray thereon. The first and second end walls depend 
from the top wall in rigid interengagement therewith for supporting the 
housing upon the surface to be sprayed during travel thereover and 
confining the sprayed mist therebetween and between the fore and aft walls 
.

DETAILED DESCRIPTION 
Referring first to FIG. 1, there is shown a perspective view of apparatus 
10 for drift free spraying of chemicals such as herbicides, insecticides 
and/or pesticides in a confined area. A housing 12 of the apparatus 10 is 
preferably coupled to a conventional tractor (not shown) for towable 
operation over a surface 16 to be sprayed. The housing 12 is constructed 
of an elongated top wall 18 rigidly interconnecting opposite end walls 20 
and 22, and fore and aft walls 24 and 26, respectively. Wheels 14 and 15 
are provided outwardly of aft wall 26 for mobile support thereof. The 
bottom portion 28 of the housing 12 is open and is adapted for abuttingly 
facing surface 16 in close proximity thereto to confine spray thereon and 
prevent spray drift therefrom. 
The housing 12 is preferably constructed of rigid sheet or plate metal, 
preferably welded one to the other and surface treated to resist the 
corrosive effects of the various types of conventional chemical sprays 
commonly utilized. A yoke assembly 30 is secured upon, and upstands from, 
the top wall 18 of the housing 12 for coupling to the tractor (not shown) 
or similar vehicle adapted for towing ambulation thereof as will be 
discussed in more detail below. The yoke 30, of the particular embodiment 
shown herein, thus includes port and starboard A-frame struts 32 and 34, 
respectively, interconnected through an upper pivot frame 36. Lower port 
and starboard pivot frames 38 and 40 are pivotally connected to the base 
of the struts 32 and 34, respectively. An hydraulic system (not shown) of 
conventional design for vehicles such as tractors is preferably provided 
for vertical, rectilinear movement of the housing 12 of this particular 
embodiment. The three point support of the housing 12 through the 
respective A-frame struts 32 and 34 thus facilitates such bidirectional 
actuation atop the surface to be sprayed. 
Referring now to FIG. 2, there is shown a front elevational, 
cross-sectional view of the housing 12, illustrating the securement of a 
spray bar 44 therein. Spray bar 44 is preferably conventional design, 
incorporating a plurality of spray nozzles 46 thereon. Nozzles 46 are 
preferably angulated toward the surface 16 for the delivery of spray 
thereto. The bar 44 is provided in a length generally equivalent to the 
length of the housing 12 for the complete application of the select 
chemical in mist form to the faced surface 16 therebelow. The chemical is 
provided to the spray bar 44 through a fitting 48 seated through the top 
wall 18 of the housing 12. A flexible hose 50 carries the chemical thereto 
from a pump and reservoir assembly shown diagrammatically as element 13, 
disposed upon and secured to the tractor or appropriate vehicle. The pump 
is preferably of the type adapted to be powered by the conventional power 
train of vehicles such as tractors. 
Referring now to FIG. 3, there is shown a side elevational, cross-sectional 
view of the housing 12, illustrating the angular deflection of the lower 
sections of fore and aft walls 24 and 26, respectively. Fore wall 24 may 
thus be seen to be comprised of a lower flexible section 54, connected 
along a hinge 56 to the upper wall section 58 thereof. Upper wall 58 is 
preferably rigidly secured to the top and side walls of the housing 12 
through welding, or the like, and is preferably made of similar material. 
The lower flexible section 54 is preferably formed of rubber, or the like, 
which is adapted for conforming to irregularities on the surface 16. For 
purposes of example only, "Neoprene" rubber of a thickness on the order of 
one-half inch has been found satisfactory. Such a material and thickness 
is durable enough to withstand the application of corrosive chemicals such 
as insecticides, herbicides and/or pesticides of conventional manufacture. 
Still referring to FIG. 3, there is shown the construction of aft wall 26, 
being comprised of a lower flexible section 60 connected along a hinge 62 
to the upper wall section 64 thereof. Upper wall 64 is preferably rigidly 
secured to the top and side walls of the housing 12 through welding, or 
the like, and is, also, preferably made of similar material. The lower 
flexible section 60 is also preferably formed of rubber, or the like, 
adapted for conforming to irregularities on the surface 16. It may be seen 
that both flexible sections 54 and 60 are inclined in general parallelism 
with an angulation toward the fore wall 24. In this manner the flexible 
sections 54 and 60 glide over the surface 16 with least resistance while 
serving as baffles to confine spray within the housing 12. 
In operation the tractor or suitable vehicle drive assembly powers the pump 
and reservoir to provide a spray emission as shown most clearly in FIG. 3. 
The spray, such as herbicides, is unaffected by wind currents outside the 
housing 12 and is applied to the foliage thereunder in the optimal mist 
configuration which, due to the wind free operation may be adjustably 
selected for specific applications. The particular structural embodiment 
of the apparatus 10 permits the housing 12 to glide over the surface 16 in 
very close proximity thereto. Unlike most prior art structures, this 
relationship is maintained in bumpy terrain and the degree of drift from 
wind blowing under the housing 12 is effectively negated. Due to the 
rectilinear translation of the housing 12 provided through the yoke 30 
when engaging a tractor having a hydraulic system the apparatus 10 is 
never incapacitated due to the surface irregularities of any size. With a 
conventional hydraulic float setting on the yoke 30 the housing 12 can be 
rendered effectively weightless and/or suitably light to ride over 
furroughs and moguls. In this manner herbicides, fertilizers and surface 
treatment chemicals can be emitted in areas such as domed football 
stadiums without risk of lateral spray contamination. It is also possible 
to provide substantially equivalent functional results with vehicles not 
having hydraulic systems as discussed below. 
As shown most clearly in FIG. 4, the sprayer 10 is showed secured to a 
truck 70 through one embodiment of an adjustable hitch 72 for towing 
therewith. The hitch 72 is comprised of a tongue 74, split yoke 76 and 
adjustment linkage 78. The yoke 76 engages the yoke 30 of the sprayer 10 
through pivot frames 38 and 40. The sprayer 10 is then permitted to pivot 
about the wheels 14 and 15 and frames 38 and 40 through length changes in 
linkage 78. The linkage 78 is preferably constructed in the form of a 
turnbuckle having upper and lower threaded members 84 and 86, one of which 
incorporates lefthanded threads and the other righthanded threads. A 
compatible, center threaded unit 88 is provided for receiving and coupling 
said threaded members. As unit 88 is rotated the length of the linkage 78 
is varied to cause selected pivoting about the wheels and height 
adjustment relative to the ground 16. 
Referring now to FIG. 5 there is shown via the use of phantom lines a side 
elevational view of the sprayer 10 being adjusted relative to the ground 
16. As may be seen from this illustration, adjustments in the linkage 78 
impart latent movements to the tongue 74 and angulation of the sprayer 10 
about the wheels 14 and 15. Since the wheels 14 and 15 are disposed 
substantially to the rear of the sprayer 10, angular movement thereacross 
is manifested in the main in height adjustment of said sprayer relative to 
the ground 16, although minor angular changes do occur. In this manner, 
once the wheels 14 and 15 are set for proper height relative to the 
sprayer 10, actual unit elevation adjustments may be easily facilitated 
through the linkage 78. Other ground curvature and related nonplanar areas 
are compensated for by the flexible sections discussed above. 
It is thus believed that the operation and construction of the invention 
will be apparent from the foregoing description. While the spray apparatus 
thereof and turn hitch therefor shown and described have been 
characterized as being preferred, it will be obvious that various changes 
and modifications may be made without departing from the spirit and scope 
of the invention as defined in the following claims.