CA2444690C

CA2444690C - Suspended floating sprayer boom

Info

Publication number: CA2444690C
Application number: CA002444690A
Authority: CA
Inventors: David Gary Mccrea; Thomas Edward Mccrea
Original assignee: Individual
Current assignee: AG Shield Ltd
Priority date: 2002-10-16
Filing date: 2003-10-15
Publication date: 2005-05-17
Anticipated expiration: 2023-10-15
Also published as: CA2444690A1

Abstract

An applicator boom apparatus comprises an applicator boom extending laterally from a vehicle, and pivotally attached to the vehicle such that the boom can pivot up and down with respect to the vehicle. A kit provides a gauge member adapted to ride along a surface of the ground and support an outer portion of the boom such that the boom moves up and down with the gauge member as the gauge member rides along the ground, and also provides an active hydraulic source powering the shoulder hydraulic cylinder of the apparatus such that the shoulder hydraulic cylinder exerts an upward force on the boom such that a downward force exerted on the gauge member by the boom is reduced.

Description

SIJS>aENDED BOOM WITH GAUGE MEMBERS
This invention is in the ~cld of applicators for applying agricultural materials such as fertitizer, herbicides, and pesticides on fields, as well as for various industrial and commercial uses, and in particular the laterally extending booms on such applicators.
BACR~ROUND
In agricultural seeding operations a~cultural materials in liquid or dry granular form are spread over the surface of a field using an agricultural applicator. Liquid applicators are most cozzxzzzonly referred to as sprayers, while dry granzalar applicators are referred to as granular applicators. Typically such applicators comprise a central container carried on a frame supported on wheels, and applicator booms extending a considerable distance to each side so that a significant width can be covered in each pass. Applicator widths of 120 feet or more are common. The agricultural materials are carried from the container along the booms by a pump, air blast, or the like as is well known in the art.
Similar applicators aze used in industrial and commercial appIicatiozas for ground maintenance ox txeatrnent.
in conventional applicators traveling typically at speeds of 5 - 8 miles per hour (zxzph), the booms are generally supported by one or mare gauge wheels such that the boom moves up and down oz~ the gauge wheels to follow the ground. The gauge wheels 2S prevent the boom from contacting the ground, and xxzaintain the proper boom height to maintain even application as the terrain varies. The operation of such a conventional.
boom with gauge wheels to allow the boom to follow the ground is disclosed in United States Patent Number 4,650,124 to Connaughty et al. in some applicators, a skid shoe or the like is used instead of a wheel to act as tlxe gauge member.
1-Iigh speed applicators knave recently become very popular, as they reduce the applicatian time considerably. These are designed to operate at relatively high speeds of 15 to 20 mph. Such high speed applicators use a "suspended boom" arrangement wherein the boom extends to the side supported only at the inner end, with no gauge members.
Gauge members have not been cornrrlonly used on high. speed applicators. The booms can be quite heavy and so considerable wei~;lat zx~,ust be caz~.ed by the gauge members.
This weight on the gauge members creates a significant rearward force, especially in soft soil. As applicator spcod increases, the rearward force exerted by resistance o~ the gauge members traveling over the ground increases as well. The boom must be sarong enough to overcome this resistance, requiring increased weight, and compounding the problem.
With a su,~pended boom, there is no resistance from gauge members. The disadvantage is that the height of the boom is not controlled except at its inside end where it is attached to the applicator frame. The outer end of the boom can contact the ground in uneven terrain, and as well the proper boom height is not maintained nearly as well as when gauge members are used.
To address this problem, it is common to provide individually controllable hydraulic cylinders, commonly referred to as "shoulder cylinders", attached between the frame and each boom such that each boom can be pivoted upward about its inner end, where it is pivotally attached to the frame. In this way the operator can control the lxeight of the outer end of each boom independently, and maintain an appropriate boom height while going through ditches and similar terrain variations_ Considerable prior art has 'been addressed to alleviating the problems associated: with suspended booms. For example, United States Patent Numbers 4,427,154 to Mercil, 4,598,830 to Fletcher, 4,643,35$ to laekson, 5,348,226 to Heiniger et al., and 6,234,407 to Knight et al. disclose variations directed to aznproved performance of suspended boom applicators.
High speed applicators are conunonly used in high standing cxops at distances of four or more feet above the ground. At these higher boom. heights, the problem of the outer end of the boom hitting the ground is much reduced, and the proper boom height is much more variable. Thus such high speed applicators with suspended booms are well suited for operations in more mature crops at increased boom heights, but are less ~eff'ective and problematic at tower boozxx heights.
SX7MIV1ARY OF Tii~ )ll~'''V'~~1'x'>(4~
IS
It is an object of the present invention to provide a suspended boom for liquid and dry applicators that overcomes problems in the prior art. It is a further object of the present invention to provide a lcit to convert existing suspended applicator 'booms to ground following boo~ais wherein the suspended boom is supported on a gauge member so that the boom can follow the ground, and wherein the weight carried by the gauge member is reduced by providing an upward biasing force on the boom, thereby roducing rearward forces oz~ the gauge xneznber.
The present invention provides, in an applicator apparatus comprising a vehicle adapted for movement along the ground, a conventional hydraulic source supplied by a pump from a hydraulic fluid reservoir, an applicator boom extending laterally from the vehicle and pivotally attached to the vehicle such that the applicator boozx~, can pivot up and dawn - Page S
with respect to the vehicle, an extendable hydraulic shoulder cylinder operatively connected between the vehicle and the applicator 'boom and connected to the conventional hydraulic source such that the shoulder eylic~der moves m a first direction. to lower the applicator boom when a valve control directs hydraulic fluid through a lowering conduit unto a lowering port of the shoulder cylinder, and moves in an opposite second direction to raise the applicator boom when the valve control directs hydraulic fluid through a raising conduit into a raising port of the shoulder cylinder, a gauge member kit for attachment to the applicator apparatus. The kit comprises a gauge member adapted to ride along a surface of the ground and adapted. for attaehmcn.t to an outer portion of the applicator boom to support the applicator boom such that the applicator boom can move up and down with the gauge member as the gauge member rides slang the ground. An active hydraulic circuit is adapted for operative connection to the raising conduit wherein an active operating pressure of the hydraulic fluid in the raising conduit can be controlled, and wherein hydraulic t7.uid can pass from the putx~.p through the active hydraulic circuit to the xaising conduit, and from the raising conduit through the active hydraulic circuit to the hydraulic fluid reservoir, whereby the shoulder cylinder extends and retracts in response to forces exerted tkzereon that are greater or less than a force exerted by the active operating pressure, and whez~ein the active operating pressure is controlled to allow the shoulder cylinder to extend and z~etract as required to allow the applicator boom to move up and down with the gauge meTnber as the gauge member rides along the ground.
Thus once the kit is installed, the gauge members essentially "feel" the ground, but cause very little drag. The boom provides improved height control in high speed operations over the boom height controls of the prior art. 'fhe kit allows installation on existing prior art suspended boom applicators to econvxnically innprove their performance at lower boom heights. The kit can be configured for installation with closed center or open centez~ hydraulic systems.
DESCRIPTION OF TIIE DRAWINGS:
't~Vhile the invention is claimed in the ovncluding portio~as hereof, preferred embodiments are provided iz~ the accompanying detailed description which may be best understood in opnjunction with the accompanying diagrams where like parts in each of the several diagraFns are labeled with like numbers, and where:
Fig. i is a rear view of an applicator apparatus;
Fig. 2 is a schc view of the conaection of an active hydraulic source to the raising lime of the slxouldex cylinder;
IS
Fig. 3 is a schematic of an active hydraulic circuit of the invention coz~x~ected to an applicator with an open center hydraulic system, where the center boom is conventional;
Fig. 4 is a schematic of an active hydraulic circuit of the inrrention connected to an applicator with a closed center hydraulic system where the center boarn is floating;
Fig. 5 is a rear view of the left side of an applicator apparatus comprising a segmented boom.
bE'fAIX.Ep DESC~tXPTION OF T'~E R,X,~CJS~'~,TED )E1VIBODIMENTS:

Fig. 1 illustrates an agricultural applicator apparatus 1 comprising a vehicle 3 adapted for movement along the ground. Typically the vehicle 3 would be a self propelled or tow behind trailer type sprayer or dry applicator. The vehicle 3 typically carries a tank 5 for carrying liquid or granular a,~icultu~ral materials to be applied, and a pump, blower, or the like to distribute the agricultural mateqials across the width of the apparatus 1.
Similar applicators are used in industrial and commercial applications for ground maintenance and treatment.
Leis and rig,~t applicator booms 7L, 7R extend laterally from the vehicle, and are pivotally attached to the vehicle 3 at pivot points 9 on the boom frame 8 such that the booms 7 can pivot up and down with respect to the vehicle 3, as indicated by arrows N.
A gauge xnenaber, illustrated as gauge wheel 10, supports an outer portion of each boom 7 such that tl~e booxu.s move up and down with the gauge wheels 10 as the gauge wheels roll along the ground. Typically the gauge wheels'10 will be castor wheels biased in a forward travel direction. The illustrated anbodiments show a gauge wheel, but in some conditions it could be desirable to substitute a skid shoe or the like adapted to ride along a surface of the ground to act as the gauge member.
An extendable hydraulic shoulder cylinder 13 is pivotally connected at each end thereof betw~n the vehicle 3 and the boom supports l~
An active hydraulic source 20 is operatively connected to each shoulder cylinder 13 by a raising conduit 21, and a lowering conduit 22. The active hydraulic source 20 supplies hydraulic fluid at an active operating pressure to the shoulder cylinder 13 such that the

2~ shoulder cylinder 13 extends and retracts in response to forces exerted thereon fat are greater or less than a force exerted by the active operating pressure.

As illustrated in Fig. 2, with are active operating pressure AF in the raising conduit 21, an upward force 1~ is excited oz~ the boom support rt 5 and boom 7, with the result that the downward force exerted on the gauge wheel 14 by the boom 7 is reduced. The force F is not sufficient to overvozne the total weight of the boozr~ 7, but instead reduces the weight on the gauge wheel 10 so that the rearward force on the boom 7 caused 'by the drag of the wheel IO is reduced. The active hydraulic source 20 allows hydraulic fluid to pass back and forth through fhe conduits 21, 22, as indicated by arrows F~, such that the shoulder cylinder 13 extends and retracts as required to allow the boom 7 to move up and down with the gauge wheel 10, floating as the gauge wheel 10 rolls along the ground.
The active operating pressure AP is adjustable, so that the upward force F on the boom ?
can be varied to suit boom design and application conditions.
A control 25 is provided so that the shoulder cylinder 13 caz~ further be selectively connected to a cvnventtional hydraulic source 30 instead of the active hydraulic source 20.
'4'Vhen connected to the conventional hydraulic source 30, the shoulder cylinder 13 extends and retracts in response to a valve control, and the boom 7 pivots up and down as the shoulder cylinder 13 e~ctends and retracts. The shoulder cylinder 13 thus provides position control of the boom 7 when in conventional mode.
The operator is thus able to switch the hydraulic system back and forth between the ground following rnodc provided by the active hydraulic source 20, and the position control mode provided by the conventional hydraulic source 30. ThE applicator apparatus I can then be used in ground following mode on short crops or bare fields with improved control of the boom height, and reduced risk of the booms hitting the ground.
The gauge wheels 10 can be vertically adjustable to pro~ride a necessary range o~F boom heights for a variety of nozzles, crop heights, at~d so forth. For use in tall crops, conventional position control made is used, and the booms 7L, 7R are raised to the required height and the attached gauge wheels 10 can be raised off the ground.
Since they carry very little weight, the gauge wheels 10 can be made quite light, such that they could be left in place during conventibnal operation. A mechanism could be provided to pivot the gauge wheels 10 up so they do .not drag on the crop. Alternatively the gauge wheels 10 could simply be removed for conventional operations.
A center boom 7C is attached to the boom frame 8 and extends laterally substantially across a width of the vehicle 3 to cover the gap bet veen the Ieft and right booms 7L, ~7R.
I O The boom frame 8 is raised and lowered by hydraulic lift cylinders 35 to adjust the height of the center boom 7C and the inner ends of the booms 7L, 7R. The gauge wheels 10 are adjusted vertically so that the booms 7L, 7R, 7C are aligned at the proper height.
Although the frame is generally well supported at a Suitable height by the wheels of the vehicle 3, a further gauge wheel 10 can be added to the center boom 7C, and the hydraulic lift cylinders 35 could be connected to an active hydraulic source to operate the center boom 7C in grownd following mode as well. This center boom ground following capability would maintain the proper height of the center boom 7C, as well as the inner ends of the left and right booms 7L, 7R attached to the boom frame 8, when the wheels of the vehicle 3 sink into mud, for example. Also on some applicators, the suspension is nat compensated so that the boom frame height changes sorx~ewhat when the tank goes from full to empty. Addition of float capabilities to the center boom provides a more stable boom height. The weight on the center gauge wheel 10 is small, such that same should not ordinarily sink into soft soil or mud to the same extent as the vehicle wheels which caz~ry coz~saderable weight.

-PagelO-A typical agricultural applicator apparatus comprises, as illustrated in Fig.

3, s conventional hydraulic source 30 supplied by a pump 50 from a hydraulic fluid reservoir 52, and a pair of extendable hydraulic shoulder cylinders 53L, 53R operatively connected to the conventional hydraulic source 30 by raising conduits 21 and io~vering conduits 22.
Flow to the shoulder cylinders is controlled by a conventional electric valve control 55 comprising conventional switches S7 that are connected by electrical leads 58 to hydraulic block 59. The raising conduits 21 and lowering conduits 22 are connected to ports in the hydraulic block 59. The conventional control SS also includes a switch 57 to control one or more center cylinders 54, also supplied from the conventional hydraulic source 30 as illustrated, to raise and lower the boom frame of the conventional applicatoriw When the conventional switch 5'7L for the left shoulder cylindez 531. is moved to the up position, the raising co~aduit 21 of the left shoulder cylinder 53L is pressuriTed at the pump pressure and hydraulic fluid passes through the raising conduit 21 to the raising port vn the left shoulder cylinder 53L causing it to retract and raise the left boom. When the conventional switch 57L is moved to the neutral position, the left shoulder cylinder 53L stops moving and the 1cft boom remains in its position until the left shoulder cylinder 53L is again activated. Moving the conventional switch 57L to the down position causes the shoulder cylinder 53L to extend and move the boom down. The system for the right shoulder cylinder 53R operates in the saxar~e way. The conventional hydraulic source 30 thus provides positional control of the shoulder cylinders and thus the booms.
The kit of the prcsart invention provides a gauge member for attachment to an agricultural applicator apparatus including such a conventional hydraulic source 3U. The kit comprises a gauge member such as the gauge wheel 10 as seen in Fig, l, typically attached to each boom 7L, 7R by clamps or the like such that they can be removed for conventional operatioza if desired.

The kit fiirther comprises an active hydraulic circuit 100, shown generally on the right side of Fig. 3. The active hydraulic circuit 100 is adapted for operative connection through a T or the like to the raising conduit 21 of each shoulder cylinder S3L, 53R such that an active operating pressure of the hydraulic fluid ire the raising conduit 21 can be controlled, and such that hydraulic fluid can pass from the pump 50 through the active hydraulic circuit 100 to the raising conduit 21, and from the raising conduit 21 back through the active hydraulic circuit '100 to the hydraulic fluid reservoir 52, whereby the shoulder cylinder 53L or 53R extends and retracts in response to forces exerted thereon that are greater or less than a force exerEed by the active operating pressure. The active operating pressure is controlled at a pxessure that allows the shoulder cylinder to extend and retract as required to allow the boam to move up and dov~rn with the gauge wheel as the gauge wheel rolls along the ground. In the embodiment illustrated in Fig.
3, the center cylinder 54 is not connected to the active hydraulic circuit 100, and operates only conventionally.
The active hydraulic circuit comprises a pressure line 102 teed. into the output line 60 from the pump 50 to direct hydraulic fluid to the input port A of a pressure reducing relieving valve 104. ~'he pressuxe z~educing relieving valve 104 provides a reduced active pressure at active port B that is connected by active line Z06 to left and right active lines 106r., 10GR. The reduced active pres"~ure can be varied '~y adjusting a pressure cor~tr'ol 108 on the pz~essur~ reducing relieving valve 104. Excess hydraulic fluid is exhausted from the pressure reducing xelieviug valve 104 through exhaust port C to the hydraulic reservoir 52.

The active lines 106L, 1068 are teed into the raising conducts 21 of the respective left and right shoulder cylinders 53L, 53R such that hydraulic fluid at the active pressure is present in the raising conduits 21. Each active line 106L, 1068 includes an active valve 110 that can be opened oz' closed by right and left latching relays 112, located on active control 115 which are signaled from the corresponding conventional switches 57, which corresponds essentially to the control 25 in Fig. 2. Solid state and mechanical devices are also known that could provide the operativzt of the latching relays 112. An active switch 113 controls power to the latching relays 112 which corresponds essentially to the coz~t~o1 25 in Fig. 2.
Thus, in convexztional mode the active switch 113 is in the off or valve closed position, and the conventional switches 57 can be used to control the boom height convcntionall~r.
In the active ,ground following mode, the active switch l I3 is in the on or open valve position, and the conventional switches 57 are in the neutral position, and the up ports LU, RU on the hydraulic block 59 that cozwentiona~lly supply the raising conduits 21 are closed. l3ydraulic fluid at the active pressure can pass into and out of the raising pozts 51 on the shoulder cylix~dez~s 53L, 53R.
xhe pressure reducing reliEVing valve 104 maintains the active pressure at a selected setting such that the upward force F is exerted on the bvoxn and the weight of the boom carried by the gauge wheel is reduced.. The pressure control i08 is adjusted so that the weight of the boom is greater than the upward force F, and the boom rides on the gauge wheel, following the contours of the ground. When the gauge wheel on one or the other boom moves down the corresponding shoulder cylinder extends, pushing hydraulic fluid back through the active line 106 through the active port B on the pressure reducing relieving valve 104 and out the exhaust port C. When the gauge wheel moves up, the shoulder cylxz~der retracts and hydraulic fluid flows from the active port B
through the active line 106 into the raising port 51. Thus the force is maintained substantially constant at value F as the shoulder cylinder extends and retracts. The shoulder cylinder acts as a bias element exerting a constant upward force F on the boom that corresponds to the selected active pressure.
In some situations, the operator may need to quickly raise a boom to clear an obstacle or the like. In the illustrated embodiment, the conventional switches 57 are connected to the active control 115 such that when the conventional switch 57L is moved to the up position, the corresponding active valve 110 is closed, reverting the system for the lets boom to conventional up operation. The right boom remains unaffected in ground following mode.
The connection between the conventional switches 57 and the actives cpntrol ~!
I S can be conh.gured to override the active control and revert to conventional operation in a variety of ways. Typically the conventional switches 57 arc of the type that return to neutral when released. By moving the conventional switch 57 to the up position, the operator overrides the active control and reverts to conventional operation. The operator can then move the selected boozxx up coz~vez~txonally by holding the convexational switch 57 in the up posxtzoz~. Once the obstacle is cleared, the operator taps the coxwentzonal switch 57 for the selected boom to the dawn position to revert to active ground following mode, and the boom float: back down until the wheel rests on 'the ground. Alternatively, the operator could move the active switch 113 to the off position and back to the on position again to change to the ground follovving mode. Using this configuration, both boozxxs would revert to conventional operation. Other can#iguratians could be used as well.
The operator can control the system using the conventional switches S7 during normal operations, where a bvozn zxxigbt need to raised to clear an obstacle. The operation is convenient, as the operator essentially operates the booxns while traveling down the field in the same way as he would conventionally, with his hand Iocated on the conventional controls.
The hydraulic system illustrated in Fig. 3 is an "open center" system wherein hydraulic fluid is pumped steadily by the pump 50 to the hydraulic block 59. When the conventional switches 57 are ixa neutral, the hydraulic fluid is bypassed through the hydraulic block 59 to return line 62 az~d thus to the hydraulic reservoir 52.
The pressure on the output line 60 is thus very 5-rnali, since the hydraulic fluid is merely circulating. In order to obtain su.'~ciel~t pressure to operate the aetiwe hydraulic circuit, it is necessary to provide a return valve 64 in the return line 62 so that the retelrn. line 62 can be closed, and pressure will rise in the output line 60.
Hydraulic fluid is only drawn from the pump when fhe boozxx zxzoves up retracting the corresponding shoulder cylinder 53. When the boom moves up, there is drop in the pressure in active luxe 106. A pressure sensor 11? is teed into the active line 106 such that when the active pressure drops, the valve 64 closes and pressure line 102 is pressurized and supplies the required hydraulic fluid at the required pressure to the pressure reducing relieving valve 104.
Fig. 4 illustrates an embodiment for use on a closed center hydraulic system.
In such systems, the pump 50 does not constantly circulate hydraulic fluid, but instead maintains pressure on the output line 60 at all times, with flow only as called for.
Thus no pressure sensor or return valve is required. In a load sensing hydraulic system a load sensing line 120 is required tell the pump SO what pressure to maintain in the system. Clne way check valves 122 are required in the load sensing line.

Fig. 4 shows a schematic hydraulic system of an embodiment wherein the center cylinder S4 that controls the height of the boom frame is also subjected to an upwaz~d force, and is supported on gangs wheels as in Fig. 1. A second pressure reducing relieving valve I04 is added in parallel with the existing pressure reducing relieving valve X 04 of Fig. 3.
Hydraulic fluid at an active pressure is thcts supplied to the center active line 10~C and through it to the raising conduit 21 of the center cylinder or cylinders 54. A
latching relay I12C to control the active value in the center active Iine is added to the active control 11 S. The center cylinder S4 and attached boom frame thus float in the sazue manner as the right and left booms. A separate pressure reducing relieving valve 104 is supplied to operate the center cylinder 54 so that a different active pressure can be selected for the outboard booms and for the boom frame. The same active pressure is satis~Factoz~y to operate the left and right booms since t~,e weight of each boom is substantially the sartae. The weight of the booxx~, frame can very substantially from one applicator to another, and the separate pressure reducing relieving valve 104 allows for independent adjustment of fibs active pressure.
Fig. 5 shows an embodiment for operating a wider boom that is segmented into an inner boom section 207A, pivotally attached at its inner end tv the boom frame 208, and an outer boom section 207B pivotally attached at its inner end to the outer end of the inner boom section 207A. An inxxer gauge wheel 210A suppvz~ts an outer portion of the inner boom section 207A, and an outer gauge wheel 210B supports an outer portion of the outer boom section 207B. Inner shoulder cylinders 2134, and outer shoulder cylinders 213B provide an upward force on respective inner and outer boom sections 207A, 207B.
The weight carried by the inner and outer gauge wheels 210A, 2108 is thus reduced, and 2S the apparatus works in the same manner as described above. Again a separate pressure reducing relieving valve 104 is provided for the left and right outer boom sectio~as to allow for independent selection of the 'upward force on the outer boozxa sections. It will be noted that increasing the upward force exerted by the outer shoulder cylinders 2I3B
on the outer boom sections 207B will increase the weight of the inner boom sections 207A carried by the inner gauge wheels 210A, requiring increasing the upward fvFCe e~certed by the inner shoulder cylinders 21.3A. Independent adjustment allows a suitable combination of active pressures to be attained.
The inner and outer boom sections 207A, 207B of Fig. ~ could be locked into alignment for conventional operation as a suspended boom.
The foregoing is considered as illustrative only of the principles of the invention.
Further, since numerous changes axxd xnc~dif~cations will xeadily occur to those skilled in the azt, it is not desired to limit the invention to the exact construction az~;d operation shown and described, and accordingly, alI such suitable changes or modifications in structure or operation which may be resorted to are intended to fall within the scope of I S the claimed. invention.

Claims

CLAIMS:
We claim:

1, In an applicator apparatus comprising a vehicle adapted for movement along the ground, a conventional hydraulic source supplied by a pump from a hydraulic fluid reservoir, an applicator boom extending laterally from the vehicle and pivotally attached to the vehicle such that the applicator boom can pivot up and down with respect to the vehicle, an extendable hydraulic shoulder cylinder operatively connected between the vehicle and the applicator boom and connected to the conventional hydraulic source such that the shoulder cylinder moves in a first direction to lower the applicator boom when a conventional electric valve control directs hydraulic fluid through a lowering conduit into a lowering port of the shoulder cylinder, and moves in an opposite second direction to raise the applicator boom when the conventional valve control directs hydraulic fluid through a raising conduit into a raising port of the shoulder cylinder, a gauge member kit for attachment to the applicator apparatus, the kit comprising:
a gauge member adapted to ride along a surface of the ground and adapted for attachment to an outer portion of the applicator boom to support the applicator boom such that the applicator boom can move up and down with the gauge member as the gauge member rides along the ground;
an active hydraulic circuit adapted for operative connection to the raising conduit wherein an active operating pressure of the hydraulic fluid in the raising conduit can be controlled, and wherein hydraulic fluid can pass from the pump through the active hydraulic circuit to the raising conduit, and from the raising conduit through the active hydraulic circuit to the hydraulic fluid reservoir, whereby the shoulder cylinder extends and retracts in response to forces exerted thereon that are greater or less than a force exerted by the active operating pressure, and wherein the active operating pressure is controlled to allow the shoulder cylinder to extend and retract as required to allow the applicator boom to move up and down with the gauge member as the gauge member rides along the ground;
an active control operative to switch the boom from conventional mode, wherein the conventional valve control directs hydraulic fluid through the raising conduit into the raising port of the shoulder cylinder and the active hydraulic circuit is disconnected, to active mode wherein the active operating pressure of the hydraulic fluid is present in the raising conduit;
wherein when the boom is in the active mode and the conventional valve control is moved in a direction to conventionally raise the applicator boom, the active hydraulic circuit is disconnected and the boom moves up; and wherein when the conventional valve control is moved in a direction to conventionally lower the applicator boom, the active hydraulic circuit is re-connected and the boom moves down.

2. In an applicator apparatus comprising a vehicle adapted for movement along the ground, a conventional hydraulic source supplied by a pump from a hydraulic fluid reservoir, an applicator boom extending laterally from the vehicle and pivotally attached to the vehicle such that the applicator boom can pivot up and down with respect to the vehicle, an extendable hydraulic shoulder cylinder operatively connected between the vehicle and the applicator boom and connected to the conventional hydraulic source such that the shoulder cylinder moves in a first direction to lower the applicator boom when a conventional electric valve control directs hydraulic fluid through a lowering conduit into a lowering port of the shoulder cylinder, and moves in an opposite second direction to raise the applicator boom when the conventional valve control directs hydraulic fluid through a raising conduit into a raising port of the shoulder cylinder, a gauge member kit for attachment to the applicator apparatus, the kit comprising:
a gauge member adapted to ride along a surface of the ground and adapted for attachment to an outer portion of the applicator boom to support the applicator boom such that the applicator boom can move up and down with the gauge member as the gauge member rides along the ground;
an active hydraulic circuit adapted for operative connection to the raising conduit wherein an active operating pressure of the hydraulic fluid in the raising conduit can be controlled, and wherein hydraulic fluid can pass from the pump through the active hydraulic circuit to the raising conduit, and from the raising conduit through the active hydraulic circuit to the hydraulic fluid reservoir, whereby the shoulder cylinder extends and retracts in response to forces exerted thereon that are greater or less than a force exerted by the active operating pressure, and wherein the active operating pressure is controlled to allow the shoulder cylinder to extend and retract as required to allow the applicator boom to move up and down with the gauge member as the gauge member rides along the ground;
an active control operative to switch the boom from conventional mode, wherein the conventional valve control directs hydraulic fluid through the raising conduit into the raising port of the shoulder cylinder and the active hydraulic circuit is disconnected, to active mode wherein the active operating pressure of the hydraulic fluid is present in the raising conduit; and wherein the kit is adaptable to an applicator apparatus having an open center hydraulic system.

3. In an applicator apparatus comprising a vehicle adapted for movement along the ground, a conventional hydraulic source supplied by a pump from a hydraulic fluid reservoir, an applicator boom extending laterally from the vehicle and pivotally attached to the vehicle such that the applicator boom can pivot up and down with respect to the vehicle, an extendable hydraulic shoulder cylinder operatively connected between the vehicle and the applicator boom and connected to the conventional hydraulic source such that the shoulder cylinder moves in a first direction to lower the applicator boom when a conventional electric valve control directs hydraulic fluid through a lowering conduit into a lowering port of the shoulder cylinder, and moves in an opposite second direction to raise the applicator boom when the conventional valve control directs hydraulic fluid through a raising conduit into a raising port of the shoulder cylinder, a gauge member kit for attachment to the applicator apparatus, the kit comprising:
a gauge member adapted to ride along a surface of the ground and adapted for attachment to an outer portion of the applicator boom to support the applicator boom such that the applicator boom can move up and down with the gauge member as the gauge member rides along the ground;
an active hydraulic circuit adapted for operative connection to the raising conduit wherein an active operating pressure of the hydraulic fluid in the raising conduit can be controlled, and wherein hydraulic fluid can pass from the pump through the active hydraulic circuit to the raising conduit, and from the raising conduit through the active hydraulic circuit to the hydraulic fluid reservoir, whereby the shoulder cylinder extends and retracts in response to forces exerted thereon that are greater or less than a force exerted by the active operating pressure, and wherein the active operating pressure is controlled to allow the shoulder cylinder to extend and retract as required to allow the applicator boom to move up and down with the gauge member as the gauge member rides along the ground;
an active control operative to switch the boom from conventional mode, wherein the conventional valve control directs hydraulic fluid through the raising conduit into the raising port of the shoulder cylinder and the active hydraulic circuit is disconnected, to active mode wherein the active operating pressure of the hydraulic fluid is present in the raising conduit; and wherein the kit is adaptable to an applicator apparatus having a closed center hydraulic system.

4. In an applicator apparatus comprising a vehicle adapted for movement along the ground, a conventional hydraulic source supplied by a pump from a hydraulic fluid reservoir, an applicator boom extending laterally from the vehicle and pivotally attached to the vehicle such that the applicator boom can pivot up and down with respect to the vehicle, an extendable hydraulic shoulder cylinder operatively connected between the vehicle and the applicator boom and connected to the conventional hydraulic source such that the shoulder cylinder moves in a first direction to lower the applicator boom when a conventional electric valve control directs hydraulic fluid through a lowering conduit into a lowering port of the shoulder cylinder, and moves in an opposite second direction to raise the applicator boom when the conventional valve control directs hydraulic fluid through a raising conduit into a raising port of the shoulder cylinder, a gauge member kit for attachment to the applicator apparatus, the kit comprising:
a gauge member comprising a caster wheel biased in a forward travel direction and adapted for attachment to an outer portion of the applicator boom to support the applicator boom such that the applicator boom can move up and down with the caster wheel as the caster wheel rides along the ground;
an active hydraulic circuit adapted for operative connection to the raising conduit wherein an active operating pressure of the hydraulic fluid in the raising conduit can be controlled, and wherein hydraulic fluid can pass from the pump through the active hydraulic circuit to the raising conduit, and from the raising conduit through the active hydraulic circuit to the hydraulic fluid reservoir, whereby the shoulder cylinder extends and retracts in response to forces exerted thereon that are greater or less than a force exerted by the active operating pressure, and wherein the active operating pressure is controlled to allow the shoulder cylinder to extend and retract as required to allow the applicator boom to move up and down with the gauge member as the gauge member rides along the ground;
an active control operative to switch the boom from conventional mode, wherein the conventional valve control directs hydraulic fluid through the raising conduit into the raising port of the shoulder cylinder and the active hydraulic circuit is disconnected, to active mode wherein the active operating pressure of the hydraulic fluid is present in the raising conduit.

5. The kit of any one of Claims 1 - 4 wherein the applicator apparatus further comprises:
a boom frame attached to the vehicle, and right and left applicator booms pivotally attached to corresponding sides of the boom frame and corresponding right and left shoulder cylinders attached to the boom frame and corresponding applicator booms;
and wherein the kit further comprises:
right and left gauge members adapted for attachment to corresponding right and left booms;
wherein the active hydraulic circuit is adapted for connection to right and left raising conduits connected to the corresponding right and left shoulder cylinders.

6. The kit of any one of Claims 1 - 5 wherein the applicator apparatus further comprises:

a boom frame attached to the vehicle, and wherein the applicator boom is pivotally attached to the boom frame and the shoulder cylinder is attached to the boom frame and applicator boom;
a center boom attached to the boom frame and extending laterally substantially across a width of the vehicle;
an extendable hydraulic center cylinder operatively connected between the vehicle and the boom frame and connected to the conventional hydraulic source such that the center cylinder moves in a first direction to lower the center boom when a center valve control directs hydraulic fluid through a center lowering conduit into a center lowering port of the center cylinder, and moves in an opposite second direction to raise the center boom when the center valve control directs hydraulic fluid through a center raising conduit into a center raising port of she center cylinder;
and wherein the kit further comprises:
a center gauge member adapted for attachment to the center boom such that the center gauge member can ride along a surface of the ground supporting the boom frame such that the boom frame moves up and down with the center gauge member as the center gauge member rides along the ground;

a center active hydraulic circuit adapted for operative connection to the center raising conduit wherein a center active operating pressure of the hydraulic fluid in the center raising conduit can be controlled, and wherein hydraulic fluid can pass from the pump through the center active hydraulic circuit to the center raising conduit, and from the center raising conduit through the center active hydraulic circuit to the hydraulic fluid reservoir, whereby the center cylinder extends and retracts in response to forces exerted thereon that are greater or less than a force exerted by the center active operating pressure, and wherein the center active operating pressure is controlled to allow the center cylinder to extend and retract as required to allow the center boom to move up and down with the center gauge member as the center gauge member rides along the ground;

wherein the center hydraulic cylinder can be selectively connected to the conventional hydraulic source or to the second active hydraulic source.

7. An applicator apparatus comprising:
a vehicle adapted for movement along the ground;
a conventional hydraulic source supplied by a pump from a hydraulic fluid reservoir;
an applicator boom extending laterally from the vehicle and pivotally attached to the vehicle such that the applicator boom can pivot up and down with respect to the vehicle;

an extendable hydraulic shoulder cylinder operatively connected between the vehicle and the applicator boom and connected to the conventional hydraulic source such that the shoulder cylinder moves in a first direction to lower the applicator boom when a conventional electric valve control directs hydraulic fluid through a lowering conduit into a lowering port of the shoulder cylinder, and moves in an opposite second direction to raise the applicator boom when the conventional valve control directs hydraulic fluid through a raising conduit into a raising port of the shoulder cylinder;

a gauge member adapted to ride along a surface of the ground and attached to an outer portion of the applicator boom to support the applicator boom such that the applicator boom can move up and down with the gauge member as the gauge member rides along the ground;
an active hydraulic circuit operatively connected to the raising conduit such that an active operating pressure of the hydraulic fluid in the raising conduit can be controlled, and such that hydraulic fluid can pass from the pump through the active hydraulic circuit to the raising conduit, and from the raising conduit through the active hydraulic circuit to the hydraulic fluid reservoir, whereby the shoulder cylinder extends and retracts in response to forces exerted thereon that are greater or less than a force exerted by the active operating pressure;

wherein the active operating pressure is controlled to allow the shoulder cylinder to extend and retract as required to allow the applicator boom to move up and down with the gauge member as the gauge member rides along the ground;

an active control operative to switch the boom from conventional mode, wherein the conventional valve control directs hydraulic fluid through the raising conduit into the raising port of the shoulder cylinder and the active hydraulic circuit is disconnected, to active mode wherein the active operating pressure of the hydraulic fluid is present in the raising conduit;

wherein when the boom is in the active mode and the conventional valve control is moved in a direction to conventionally raise the applicator boom, the active hydraulic circuit is disconnected and the boom moves up; and wherein when the conventional valve control is moved in a direction to conventionally lower the applicator boom, the active hydraulic circuit is re-connected and the boom moves down.