Boom mounting and control assembly

An apparatus for controlling the horizontal and vertical orientation of a boom assembly. An elongated frame assembly adapted to be mounted to a vehicle has a cam plate mounted to and moveable therealong. Hydraulic drive means controls the movement of the cam plate between fully extended, intermediate, and fully retracted positions. A hinge plate assembly is rotatably mounted to the frame assembly and an elongated boom, such as an agricultural spray boom, is pivotably mounted to the hinge plate so that the boom is vertically adjustable relative to the ground. The cam plate is adapted to engage the hinge plate and the boom in such a way that when the cam plate is moved along the frame assembly between the fully extended and intermediate positions, it adjusts the boom height relative to the ground and when the cam plate is moved between the intermediate and fully retracted positions, it causes the hinge plate to rotate about its pivot axis, thereby swinging the boom toward and into its retracted (traveling) position.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to boom mounting and control apparatus. More 
particularly, the invention relates to an apparatus for mounting and 
controlling the orientation of a boom on a vehicle mounted frame by means 
of a single hydraulic drive mechanism. The invention is particularly 
adapted for controlling the operating orientation and extension and 
retraction of agricultural spray boom assemblies mounted on a tractor by 
means of a single hydraulic drive on each side. 
2. Description of the Prior Art 
Agricultural spray booms have been used for a number of years. These booms 
are generally mounted on a tractor and spray nozzles are positioned along 
the boom arms. The tractor is then driven across the field as the crops 
are sprayed. This allows a relatively wide swath to be covered with each 
pass through the field. Known types of agricultural spray boom assemblies 
are shown, for example, in U.S. Pat. No. 3,581,993, issued June 1, 1971, 
to Robert M. Reams and U.S. Pat. No. 3,514,038, issued May 26, 1970 to 
Alvin E. McQuinn. 
Devices of the type shown in the Reams and McQuinn patents use hydraulic 
mechanisms to either raise and lower the spray boom (Reams) or to 
longitudinally extend and retract the booms (McQuinn). Other standard 
hydraulically powered spray booms in the industry utilize one set of 
hydraulic cylinders to fold the ends of the boom toward the tractor when 
turning at the ends of a row or when transporting the device from field to 
field and a second set of hydraulic cylinders to adjust the height of the 
boom ends to allow for unlevel field conditions. The Reams and McQuinn 
patents disclose devices that have limited adjustment capability. The 
other types of known devices which use multiple sets of hydraulic 
cylinders are costly to manufacture and maintain. Further, the vehicle, 
such as the tractor, must be equiped with at least four sets of remote 
cylinders; this is usually not standard equipment on farm tractors. 
The present invention provides an apparatus that allows for multiple 
adjustability of the spray booms while employing only two hydraulic 
cylinders, one on each side of the tractor. The apparatus of the invention 
is advantageous in that it can be used with tractors that have as standard 
equipment two hydraulic take-offs, it is less expensive to manufacture and 
operate since it only employs two hydraulic drives, and it is easier to 
operate because only one control lever is needed per side (rather than the 
two control levers per side required with a four cylinder unit). 
SUMMARY OF THE INVENTION 
This invention relates to an apparatus for controlling the horizontal and 
vertical orientation of a boom assembly. An elongated frame assembly is 
adapted to be mounted to a vehicle, such as a tractor. A cam plate is 
mounted to and moveable along the frame assembly. Hydraulic drive means 
coupled to the frame assembly and the cam plate controls the movement of 
the cam plate between fully extended, intermediate, and fully retracted 
positions. A hinge plate assembly mounts to the frame assembly by means 
that substantially prevents longitudinal movement of the hinge plate while 
permitting rotational movement thereof relative to the frame. An elongated 
boom, such as an agricultural spray boom, is pivotably mounted to the 
hinge plate so that the boom is vertically adjustable relative to the 
ground. The cam plate is adapted to engage the hinge plate and the boom in 
such a way that when the cam plate is moved along the frame assembly 
between the fully extended and intermediate positions, it adjusts the boom 
height relative to the ground; when the cam plate is moved between the 
intermediate and fully retracted positions, it causes the hinge plate to 
rotate about its pivot axis, thereby swinging the boom between its 
extended (operating) position and its retracted (traveling) position.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The boom mounting and control assembly of this invention as shown in the 
drawing and described herein is particularly adapted for use on 
agricultural equipment. It should be self evident, however, that the 
invention is not so limited; it would, in fact, be applicable to any boom 
mounting situation where it is required to both raise and lower the boom 
assembly and to retract it at times to reduce the overall width of the 
equipment (usually a vehicle) on which the boom is mounted. The 
agricultural spray boom assembly described below and shown in the drawing 
figures depicts only one-half the complete unit. FIGS. 1 and 4-8, for 
example, all show one side of the complete assembly. The portion shown is 
mounted to a tractor (not shown but off to the left in FIGS. 1, 4, and 5 
and 8). 
The boom mounting and control assembly of the invention includes a frame 
10, which may be an I-beam or box beam. In the preferred embodiment, a box 
beam is used to which wings or rails 12 have been added as guideways. A 
cam plate 14 slideably mounts on frame 10. As seen clearly in FIG. 3, the 
sides 16 of cam plate 14 extend downwardly and have internal recesses 17 
to form guideways for rails 12. Cam plate 14 may thus be securely but 
slideably mounted on box beam frame 10. 
A hinge plate 18 is pivotably mounted to the underside of frame 10. A pivot 
pin 20 extends through corresponding openings in the hinge plate 18 and 
frame 10. Surrounding the pin is a spring 22, the compression of which is 
adjustable by a nut 24 and washer 25 on the end of pivot pin 20. As nut 24 
is tightened, spring 22 exerts increasing pressure against hinge plate 18 
thereby increasing the friction coupling between the cooperating faces of 
hinge plate 18 (through plate 36) and frame 10. 
A boom 26 is mounted to the hinge plate 18 by a pivot pin 28. The pivot 
axis represented by pin 28 is substantially orthogonal or perpendicular to 
the pivot axis represented by pin 20. Thus, boom 26 can pivot relative to 
hinge plate 18 in the manner shown in FIG. 4. Hinge plate 18 and boom 26 
are together capable of rotating about pivot axis 20 relative to frame 10 
in the manner shown in FIG. 5. 
A hydraulic drive mechanism 30 is composed of a cylinder 32 and piston 34 
connected to a source of hydraulic fluid (not shown). The cylinder 32 is 
secured at one end 33 to a mounting member 11 welded to frame 10; the 
piston 34 is secured at its free end 35 to a mounting member 15 on cam 
plate 14. The hydraulic drive 30 is controlled in a known way, such as 
through a hydraulic fluid control system having a control lever mounted on 
a panel within reach of the tractor operator. As the piston 34 moves in 
and out of cylinder 32, it causes cam plate 14 to slide along frame 10 for 
purposes to be described below. 
Hinge plate 18 carries an intermediate plate 36 on which are fixed cam 
follower pins 38 and 39. Plate 36 has a key or rib 40 that seats in a slot 
or keyway 42 in plate 18. When the unit is assembled, plate 36 effectively 
becomes an integral part of hinge plate 18. Obviously, if manufacturing 
techniques permit or desire, pin 38 could be fitted and fixed directly to 
the upper surface of plate 18 without intermediate plate 36. 
When the apparatus is fully assembled, pin 38 lies between and in the path 
of movement of two cam fingers 44 and 46 that are welded or otherwise 
securely fixed to the bottom of side face 16 of the cam plate and extend 
laterally outwardly from the cam plate as shown in FIG. 3. Engagement of 
pin 38 by one or the other of cam fingers 44 and 46 causes a rotational 
movement of hinge plate 18, and thus boom 26, about pivot axis 20 in the 
manner described in more detail below. Pin 39 engages an extension 43 of 
cam finger 46 only when plates 18 and 36 have been rotated into a "boom 
retracted" position by the action of cam finger 46 against pin 38. 
A variation of the multiple cam finger embodiment is shown in FIG. 3A. 
Here, the cam plate 14' has a downwardly extending side face 16', as in 
the above described embodiment. However, instead of cam fingers 44, 46, 
the modified version has a plate 45 having a substantially "J"-shaped slot 
or guideway formed therein. Pin 38 seats in guideway 47. Pin 39 lies 
beneath plate 45 and engages an extension plate 43' at the front of plate 
45 only when hinge plate 18 has been rotated into the "boom retracted" 
position. The effective operation of cam plate 14' is essentially the same 
as that of cam plate 14. 
In the embodiment shown, cam plate 14 is coupled to boom 26 in the 
following way. A socket member 48 is welded or otherwise secured to the 
front end portion of cam plate 14. A boom support member 50 seats in 
socket member 48 in a way that allows boom support member 50 to rotate 
about its longitudinal axis within socket member 48. A support cable or 
rigid rod 52 (shown in FIG. 4) extends from the upper part of boom support 
member 50 to an outer end portion of boom 26. 
Finally, a hinge plate bias spring 54 has one end fixed to a support member 
56 which in turn is welded or otherwise securely fastened to frame 10. The 
other end of bias spring 54 is coupled through a coupler bar 58 and 
coupling pin 60 to hinge plate 18. Spring 54 biases hinge plate 18 toward 
the "boom extended" or operating position, as will be discussed in more 
detail below. 
The apparatus of this invention operates in the following way. Cam plate 14 
is slidable along rails 12 of frame 10 under the control of hydraulic 
cylinder mechanism 30. Cam plate 14 is movable between a fully extended 
piston position (shown in FIG. 6) and a fully retracted piston position 
(shown in FIG. 7). In the fully extended piston position, cam plate 40 is 
at the outermost reach of travel along rails 12. In this position, 
follower pin 38 will lie between cam fingers 44 and 46 close to or 
adjacent finger 44. Pin 39 rests in front of pin 38 adjacent the frame 10. 
Cam finger 44, acting against pin 38, in combination with the force of 
bias spring 54, causes hinge plate 18 to pivot about pivot axis 20 toward 
and into the boom extended position (shown in dashed line in FIG. 5). When 
cam plate 14 is in its first, or outermost position, boom 26 will rest in 
its lowest operating position (as shown in dashed line in FIG. 4). From 
this first, outermost position of cam plate 14, the hydraulic mechanism 
may be activated by the vehicle operator to draw piston 34 into cylinder 
32. This action causes cam plate 14 to slide inwardly (toward the left in 
FIG. 1) toward a second, intermediate position with cam finger 46 lying 
adjacent cam follower pin 38. The movement of cam plate 14 between the 
first, outermost position and the second, intermediate position (also 
along leg 47a in the variation shown in FIG. 3A) does not affect the 
lateral orientation of the boom. That is, movement of cam plate 14 between 
its first and second positions does not impart any pivot forces to cam 
follower pin 38; thus hinge plate 18 remains biased by spring 54 to 
maintain boom 26 in the extended position. 
Movement of cam plate 14 between its first and second positions does, 
however, affect the vertical orientation of boom 26. As cam plate 14 is 
moved inwardly from its outermost position to its intermediate position, 
boom 26 pivots about its pivot axis 28 and is raised from its lowermost 
position to its uppermost position (shown in solid line in FIG. 4; see 
also FIG. 8). Of course, it is contemplated that the movement of cam plate 
14 may be stopped at any point between its outermost and intermediate 
positions to thereby permit adjustment of boom 26 to any desired operating 
height between its lowermost and uppermost positions. 
When the hydraulic drive mechanism 30 is again activated to withdraw piston 
34 fully into cylinder 32, cam plate 14 thereby slides along rails 12 from 
its intermediate second position to a third, innermost position (shown in 
FIG. 7). As cam plate 14 slides along rails 12 between its second and 
third positions, cam finger 46 engages cam follower pin 38. As cam plate 
14 continues to move from its second to its third positions, cam finger 46 
acts on follower pin 38 and imparts a rotational force sufficient to 
overcome the biasing force of spring 54. (Similarly, in FIG. 3A, pin 38 
follows the path of leg 47b.) Hinge plate 18 is thereby caused to rotate 
about pivot axis 20 (in the direction of arrow A in FIG. 9) and to thereby 
rotate boom 26 from its extended operating position (shown in dashed line 
in FIG. 5) to its retracted traveling position (shown in solid line in 
FIG. 5). At the same time pin 39 is rotated about pivot axis 20 to come to 
rest in front of extension plate 43 (or 43'). Boom 26 will remain in its 
retracted position as long as cam finger 46 continues to bear on follower 
pin 38. 
To return to the "boom extended" operating position, the operator activates 
the hydraulic drive mechanism 30 to force piston 34 out of cylinder 32. 
This causes cam plate 14 to slide on rails 12 outwardly (toward the right 
in FIG. 1) along frame 10. As cam plate 14 slides from its third, 
innermost position to its second, intermediate position, the force applied 
by cam finger 46 on follower pin 38 is decreased. Extension plate 43 (or 
43') engages pin 39 to urge, together with the force of bias spring 54, 
hinge plate 18 into rotation toward the "boom extended" position. At an 
intermediate rotation point, pin 39 slides off plate 43; finger 44 engages 
pin 38 to continue moving hinge plate 18 toward and into the "boom 
extended" position. Thus, as cam plate 18 is moved from its third, fully 
retracted position to its second, intermediate position (in the absence of 
bias spring 54), cam finger 44 urges pin 38, hinge plate 18 and boom 26 
toward and into "boom extended" operating position. As cam plate 14 
continues to move outwardly under the force of expanding piston 34 from 
its intermediate, second position to its outermost first position, boom 26 
(which is now in its fully extended, operating position) is lowered to its 
desired operating height. 
As can be seen from the foregoing, the present invention provides a 
substantial advantage over known apparatus which requires the use of 
multiple hydraulic mechanisms or combinations of hydraulic, electric and 
manual operations to both adjust the boom operating height and boom 
extension and retraction (e.g., for operating and traveling modes, 
respectively). 
This invention may be embodied in other specific forms without departing 
from the spirit or essential characteristics thereof. The present 
embodiment is therefore to be considered in all respects as illustrative 
and not restrictive. The scope of the invention is indicated by the 
appended claims rather than by the foregoing description, and all changes 
which come within the meaning and range of equivalency of the claims are 
therefore intended to be embraced herein.