US3538985A - Machine for thinning and hoeing rows of plants - Google Patents

Machine for thinning and hoeing rows of plants Download PDF

Info

Publication number
US3538985A
US3538985A US749117A US3538985DA US3538985A US 3538985 A US3538985 A US 3538985A US 749117 A US749117 A US 749117A US 3538985D A US3538985D A US 3538985DA US 3538985 A US3538985 A US 3538985A
Authority
US
United States
Prior art keywords
pressure
contact
relay
hydraulic
valve
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US749117A
Other languages
English (en)
Inventor
Arnold Gego
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Individual
Original Assignee
Individual
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Individual filed Critical Individual
Application granted granted Critical
Publication of US3538985A publication Critical patent/US3538985A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01B—SOIL WORKING IN AGRICULTURE OR FORESTRY; PARTS, DETAILS, OR ACCESSORIES OF AGRICULTURAL MACHINES OR IMPLEMENTS, IN GENERAL
    • A01B41/00—Thinning machines
    • A01B41/06—Thinning machines with electric, e.g. photo-electric control of thinning operations
    • A—HUMAN NECESSITIES
    • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
    • A01B—SOIL WORKING IN AGRICULTURE OR FORESTRY; PARTS, DETAILS, OR ACCESSORIES OF AGRICULTURAL MACHINES OR IMPLEMENTS, IN GENERAL
    • A01B41/00—Thinning machines
    • A01B41/04—Thinning machines with rotating tools

Definitions

  • This invention relates to a machine for thinning and hoeing rows of plants, the machine being of the type having at least one rotatably mounted tool disc on which hoeing-tools are mounted rigidly in generally radial arrangement, a plant feeler mounted behind each tool disc and a control device for operating and subsequently stopping the tool disc after a plant to be retained has been sensed'by the feeler.
  • a machine of this type it is possible to remove from a row of standing plantsfa certain number atcertain distances apart, so that the remaining plants can grow without hindrance. It is also possible to hoe spaces between plantsinspaced rows.
  • each tool disc is driven mechanically.
  • the drive is derived from the crankshaft of a tractor drawing the machine, and is transmitted for exam'ple through a'worm drive, a shaft, a conical gear drive, an articulated shaftand finally through a clutch to the tool disc.
  • An object of the. invention is-to provide a machine of the type referred to,wherein eachtool disc is hydraulically driven and control of the movement "of .each tool disc is electrohydraulic.
  • the hoeing tools are. not mounted rigidly-on the tool disc,;but areable to perform controlledpivotal movementsperpendicularly tothe plane of rotation of the tool disc between endpositions radial andparallel to the axis of rotation for "thepurpose of leaving standing certain plants during rotation of the tool disc.
  • a plant feeler is mounted in front of each tool disc and not behind it. Consequently, the machine in question belongs to another type of thinning and hoeing'machines' for rows of plants.
  • each tool disc is hydraulically driven and is mounted on the driving shaft of a hydraulic-motor or is conv nected theretoin amotion-transmitting manner, the feed pipe r of each hydraulic motor-being in direct connection with same and always being subject to constant fluid pressure, a control valve beingarranged in the return pipe of the oreach'hydraulic motor' which valve, under the action of the controldevice, closes or opens the return pipe.
  • each tool disc is mounted on the driving shaft of its hydraulic motor with interposition of an annular elastic coupling connected to the driving shaft.
  • This arrangement works well both for the hoeing tools and for the hydraulic motor when, during rotation of the tool discs, their hoeing tools encounter resistance, for example stones, because in this manner the hoeing tools and hydraulic motors are protected to some extent from shock.
  • each feed pipe there is arranged in each feed pipe at least one hydraulic pressure storage device and a hydraulic pressure storage feed device between a hydraulic pump and the pressure storage device, the said feed device having a nonret'urn valve and a pressure regulating valve connected with the return pipe.
  • the pressure regulating valve may be adjusted to a desired pressure. Since the number of revolutions of the hydraulic motor depends upon the fluid pressure obtaining in its feed pipe the possibility arises of altering the length hoed by the hoeing tools when the speed of travel of the machine remains constant.
  • each feed pipe for obtaining constant fluid pressure in each feed pipe, there may be arranged in each feed pipe at least one hydraulic pressure storage device and between the hydraulic pump and this pressure storage device an excess pressure valve connected to the return pipe, and further a hydraulic valve disposed behind the excess pressure valve and being electromagnetically operated in accordance with the pressure in the feed pipe, the said 7 further hydraulic valve allowing pressure fluid to pass into the return pipe when a set fluid pressure is exceeded.
  • an electrohydraulic pressure control means is disposed in the feed pipe of the hydraulic motor which control means acts upon an electromagnetic switch which operates the hydraulic valve.
  • the electrohydraulic pressure control means can be set for various pressures. This, if required, makes it possible by-thealternation of the fluid pressure prevailing in the feed pipe of the hydraulic motor or motors to alter the length hoed by the hoeing tools at constant speed of travel of the machine.
  • the length .hoed by the hoeing tools depends on the pressure in the feed pipe pressure gauge, calibrated to units of length of the hoeing length, may be inserted in the feed, pipe.
  • This pressure gauge indicates the length hoed by the hoeing tools in unit time at the pressure in the feed pipe.
  • an electromagnetic switching device for operating the control valve in each return pipe an electromagnetic switching device may be provided, which is switched on when a plant to be retained is sensed and thereby moves the control valve into its open position, and, after a certain rotary movement of the relevant tools disc, is
  • a hydraulic motor which has aninternal leak oil return .flow.-Such a hydraulic motorhas'the advantage'that, even inthe case of high counter pressure of about 70 atmospheres in its return pip'e, it doesnot requirean external leak oilpipe, which would have an adverse effect.
  • an electric feeler circuit which circuit includes an electric contact feeler, an amplifier and a potentiometer for setting the feelerfsensitivity.
  • each electromagnetic switching device there may be provided a switch and on the relevant tool disc an operating member for the switch.
  • the switch and the operating member are preferably so disposed in relation to one another that they shut off the control valve of the return pipewhen the corresponding tool disc with its hoeing tools is outside the range of the plants.
  • the switch preferably a contactless terminal switch with a reed contact is provided, while the operating elenected with the switch for initiating switching off of the electromagnetic switching device, andhas three high-resistance relays connected in parallel to the electromagnetic switching device and operating a series of contacts for switching the switching device on and off as necessary.
  • FIG. 1 is a side elevation of a machine
  • FIG. 2 is a rear elevation
  • FIG. 3 is a rear elevation of a tool disc
  • FIG. 4 illustrates a tool disc and a hydraulic motor, partly in longitudinal section and partly in side elevation
  • FIG. 5 is an electrohydraulic circuit diagram, including a tool disc and a hydraulic motor, all parts being shown in the position they occupy when the tool disc is stationary;
  • FIG. 6 is the same as FIG. 5, but with all parts in the position they occupy when the tool disc rotates;
  • FIG. 7 is a circuit diagram of another embodiment of the hydraulic devices for conducting pressure fluid at constant pressure to each hydraulic motor
  • FIG. 8 is a circuit diagram of an electrohydraulic pressure control means shown in FIG. 7;
  • FIG. 9 is a diagram showing five tool discs and their hydraulic motors, and hydraulic devices for conducting pressure fluid to the hydraulic motors and a control slide valve disposed in the return pipe of each hydraulic motor;
  • FIG. 10 is a diagram ofa row of plants to be treated.
  • FIG. 10 shows the conditions in a row of plants when singling out plants in this row by means of the machine of the invention, wherein plants remain only at certain minimum distance apart, while the other plants are removed.
  • This FIG. shows that, after sensing a plant which is to be retained, at a distance a in the direction of movement of the machine beyond that plant the ground is hoed for a length H. The plants in this length H are removed. The next plant adjacent the length H is not hoed out, irrespective of whether it is at a greater or less distance beyond the hoed length H. When this plant has been sensed further hoeing takes place beyond it.
  • the machine illustrated has, referring to FIGS. 1 and 2, a basic frame 11 which consists of a lower horizontal beam 12, two spaced uprights 13, I4 and an upper horizontal beam 15 which connects the upper ends of the uprights.
  • the basic frame 11 is connected to the rear end ofa three-point linkage 16 with the aid of which the machine can be connected to a tractor (not shown).
  • the machine is supported on the ground by wheels 17, 18. These are mounted in forks I9, 20 the upper parts of which are rotatably mounted in parts of the lower beam 12 and are connected by a horizontal link 21 for steering the wheels.
  • each hoeing assembly 22 mounted on the rear side ofthe frame 11 at distances apart corresponding to the distances apart of rows of plants to be worked are five hoeing assemblies 22.
  • the forward ends of the lever arms 23. 24 are pivotally connected to flanges 25, 26 formed on the underside of the beam 12 and at their rear ends wheels 27, 28 are mounted to support the corresponding hoeing assembly 22.
  • the wheels 27, 28 are mounted in supports 29 attached to the rear ends of the lever arms 23, 24.
  • a hydraulic motor 30 is secure between the rear ends of the lever arms 23, 24 of each assembly 22.
  • the hydraulic motor 30 is ofthe type which has an inner leak oil return flow, with a feed pipe 31 and a return pipe 32 for the pressure fluid.
  • ljach hydraulic motor 30 has a rearwardly extending driving shaft 33 on which is mounted a tool disc 34 to which in radial, equidistant arrangement six hoeing tools 35 are rigidly attached. Each hoeing tool 35 has a hoeing blade 36 at its outer end.
  • the disc 34 is mounted on the shaft 33 by a hub 37, which consists of an outer ring portion 38 of metal, an inner ring portion 39 of metal, and a rubber ring 40 between these two metal ring portions. Transmission of rotation from the driving shaft 33 to the tool disc 34 is by a key 41 (FIG. 4) in keyways formed both in the inner ring portion 39 and in the driving shaft 33.
  • a casing 42 is provided for each hydraulic motor 30 and tool disc 34, which partly surrounds them.
  • the casing is also fixed to the lever arms 23, 24.
  • each casing 42 At the rear end of each casing 42 is a cross bar 43 which carries a holder 44 for a plant feeler 45 the rear side of which is electrically insulated.
  • the plant fceler 45 is stirrup-shaped and is mounted on the holder 44 so as to be adjustable in height.
  • the holder 44 is mounted on the cross bar 43 so that its distance can be varied.
  • an oil tank 46 On the uprights 13, 14 and on the upper beam 15 an oil tank 46 is mounted, and below it is anoil pump 47 driven from the crankshaft of the tractor and for this purpose provided with a drive connection 47a. Also below the oil tank 46 is a hydraulic pressure storage loading device 48. Also, on the upper side of the beam 12 two hydraulic pressure storage devices 49, a pressure gauge 50 and a control box 51 for the reception of parts of the control device, are disposed.
  • the oil pump 47 and the oil tank 46 are connected by a pipe 52.
  • the oil for driving the hydraulic motors 30 is fed from the pump 47 through a pipe 53 to the pressure storage loading device 48.
  • a pipe 54 which leads to a common feed pipe 55.
  • a nonreturn valve 56 which prevents return flow of oil from the common feed pipe 55.
  • a pipe 57 branches off from the pipe 53 to a pressure regulating valve 58, from which a pipe 59 leads to a common return pipe 60. Should the oil pressure in the pipes 53, 54, 57 exceed a given value, oil flows through the regulating valve 58 and is fed back to the common return pipe 60 via the pipe 59 until the pressure falls to the intended value.
  • a pressure may be set at which the regulating valve 58 will allow oil to pass.
  • the oil pressure in the common feed pipe 55 will therefore be constantly held at a desired value by the pressure storage loading device.
  • the hydraulic pressure storage devices 49 Connected to the common feed pipe 55 are the hydraulic pressure storage devices 49, ofwhich only one is seen in FIGS. 5 and 6.
  • these pressure storage devices 49 is stored oil under pressure, and their purpose is to supply oil to the hydraulic motors 30 in emergency. In order to avoid loss ofoil pressure in this event, the devices are gas-pressurized.
  • a pressure gauge 50 Connected to the common feed pipe 55 is a pressure gauge 50, with a scale calibrated in units of length of the hoeing length.
  • a hydraulic control slide valve 61 operated by a valve solenoid 62 by which the control slide valve 61 can be moved to either of two positions. In one position (FIG. 5) it closes the return pipe 32 of the hydraulic motor 30 in question, while in the other (FIG. 6) it opens the return pipe 32.
  • the return pipe 32 leads from the control slide valve 61 to the common return pipe 60, which in turn leads to an oil filter 63 connected to the tank 46.
  • FIG. 7 corresponds to that shown in FIGS. 5 and 6, except that the pressure storage loading device 48 is omitted and instead other devices are provided.
  • a pipe 64 branches off and leads to an excess pressure valve 65 which in turn is connected through a pipe 66 to the common return pipe 60.
  • the pipe 53 leads to a hydraulic valve 67 which can be moved into either of two positions by a solenoid 68. In one position the hydraulic valve 67 connects the pipe 53 to a pipe 69 which leads to the common feed pipe 55. In its other position (FIG. 7) the hydraulic valve 67 connects the pipe 53 to a pipe 70 which leads to the common return pipe 60.
  • the solenoid 68 is operated by an electrohydraulic pressure control means 71.
  • This pressure control means (FIG. 8) has a casing 72 connected by a pipe 73 to the common feed pipe 55. Within the casing 72 is a piston 74 subject to the pressure of a spring74a. The oil pressure in the common feed pipe 55 acts on the piston 74.
  • the piston 74 has a piston rod 75 which carries a contact member 76 at its outer end. By means (not shown) the pressure exerted by the spring 74a upon the piston 74 can be adjusted.
  • the pressure control means 7l is also connected to a source of current 77 and has wires 78, 79 which lead to the solenoid 68 of the hydraulic valve 67.
  • the connection 78 can be opened or closed by the contact member 76 of thepiston rod 75.
  • the hydraulic arrangement shown in FIG. 9 for feeding oil under pressure to the five hydraulic motors 30 correspond to the hydraulic arrangements shown in FIGS. 5 and 6 and, for controlling the oil pressure, also include a pressure storage loadingdevice48.
  • FIG. 9 will be seen the connection of each hydraulic motor 30 by its l'ccd pipe 3] to the common l'ecd pipe 55 and by its return pipe 32 to the common return pipe 60, and the arrangement of a control slide valvc 6
  • Each hoeing assembly '22 has a control device.
  • Theparts of thcsc control devices are particularly shown in FIGS. 5 and 6.
  • .Iiaclicontrol device incorporates a plant feeler 45, which is an electric touch feeler connected by a input signal conductor 88, which has a contactbto an amplifier 89. Also connected to the amplifier 89 by a conductor 90 is an earthing contact 91. When a plant is touched by the feeler 45 and the contact b is closed, a circuit is closed through the conductor 88, contact b feeler 45, the. plant, the soil, the earthing contact 91, and the conductor 90, through which the feeler current can flow.
  • the feeler circuit is supplied with current from a source 92. From this source 92 the amplifier 89 is also supplied with current. Thisamplifier amplifies the current flowing in the feeler circuit and provides output power signals via first and second output signal lines 104 and 104' respectively.
  • a potentiometer 93 is connected tothe feeler circuit and the amplifier 89.
  • this potentiometer 93 the sensitivity of the feeler circuit and ofthe feeler 45 can be set.
  • the control device also has current connections 94 to which first and secondpower wires 95 and 96 are attached.
  • the wire 96 leads to a 'contactless terminal switch97 which has a protective gas filling and a reed contact 98.
  • the solenoid 62 of the control device of each hoeing assembly 22 is connected by means of a wire 100, in which is a contact b,', to the wires 95, 96.
  • the control device includes three high resistance relays A, B and C connected to the wires 95, 96 in parallel with the solenoid 62.
  • the first relay A is connected in series with the contactless terminal switch 97 by a wire 101 and has a wire 102 shutting the terminal switch 97, contacts a and b being disposed in the wire 102.
  • the second relay B has a wire 103 with two parallel branches 103a and 103b. In the branch 103a is a contact c the branch 103b having a contact a,.
  • the third relay C is connected to the feeler circuit by a wire in the first part of which adjoining the wire 96 is a contact 0,.
  • the relay C behind the part of the wire 105' having the contact a has a wire 105 with which the wire 105 can be shunted.
  • the l'ecler circuit is closed. This causes through an output signal wire I04 operation of therelay C so that contact c closes and the relay C is connected to the wire 96 through the wire 105 and remains pulled in even if the feeler circuit should be again opened. Voltage is also applied to output signal I04 from amplifier 89. By operation of the relay C contact 0, is also closed, so that the relay B is connected to the wire 96 through the branch 103a and is pulled in. Operation of the relay B results in closing of the contact b,.
  • the solenoid 62 is connected to the wire 96 and is excited, so that it moves the control slide valve 61 into the position to open the return pipe 32 of the hydraulic motor 30. This sets the hydraulic motor 30 and the tool disc 34 in motion, and the hoeing tools 35 will hoe the ground behind the plant sensed, along the hoeing length H.
  • a machine l'oi rnovt-nn'ut along, rows of plnnls l'or lltin mag and hoeing the plants comprising a frame, at least one tool support member mounted on said frame for unlimited rotation, hoeing tools mounted rigidly on said tool support member in a radial array, a rotary hydraulic motor having an output shaft drivingly connected to said tool support member for rotating said tool support member upon actuation of said rotary hydraulic motor, a source of hydraulic fluid, a feed pipe connecting said rotary hydraulic motor and said source of hydraulic fluid, pressure means in said feed pipe to constantly provide substantially constant pressure fluid to said motor, an exhaust pipe extending from said rotary hydraulic motor for returning exhaust fluid to said source of hydraulic fluid, control valve means in said return pipe operable for opening and closing said return pipe to permit said motor to rotate said tool support or to stop said tool support in fixed position, a plant feeler mounted on said frame behind each rotatable mounted tool support member for detecting plants and control means connected to said feeler and said control
  • Machine according to claim I wherein a pressure gauge, calibrated in units of length of the hoeing length, is provided in the feed pipe ofthe hydraulic motor.
  • said control means includes an electromagnetic switching device which is switched on by the control device when a plant to be retained is sensed and thereby moves the control valve to the open position, and is switched off after a given rotary movement of the tool support member, thereby moving the control valve to the closed position to stop rotation of said tool support member.
  • said pressure means comprises a hydraulic pump and additionally including at least one hydraulic pressure storage devicein said feed pipe, a nonreturn valve in said feed pipe between said hydraulic pressure storage device and said hydraulic pump and a pressure regu lating control valve connected to said feed pipe between said nonreturn valve and said hydraulic pump for directing pressurized fluid from said pump to said exhaust line when the pressure of said fluid from said pump exceeds a given value and for bypassing said fluid around said nonreturn valve when the pressure olsaid fluid from said pump is below said given value.
  • said pressure regulating valve includes adjustment means to vary the given pressure to consequently vary the pressure of hydraulic fluid provided to said hydraulic motor.
  • said pressure means comprises a hydraulic pump and additionally including at least one hydraulic pressure storage device in said feed pipe between said pump and said hydraulic motor, an excess pressure release valve connected in said feed pipe between said hydraulic pressure storage device and said pump responsive when subjected to pressure exceeding a critical value to provide communication between said feed pipe and said exhaust pipe, an electromagnetically operated valve located in said feed line between said hydraulic pressure storage device and said connection to said excess pressure release valve operable for either directing pressurized fluid from said pump to said exhaust pipe or to said hydraulic motor and control means for actuating said electromagnetically operated valve to direct fluid from the pump to the motor in response to the detection of pressure below a set low-pressure value in the portion of said feed line downstream from said electromagnetically operable valve.
  • control means for actuating said electromngnetically operated valve includes a contact member connected to a piston rod of a piston and cylinder having one end of said cylinder connected to said feed line downstream of said electromagnetically operated valve and spring means biassing said piston in a direction opposite the direction of force on said piston created by pressure in said feed line.
  • control means additionally includes circuit means connected to said feeler, an amplifier and a potentiometer for adjusting the sensitivity of said feeler.
  • control means includes switch means mounted adjacent said tool support member and an operating member on said tool support member operable for closing said switch means when said tool support member is in a given position of rotation.
  • control means includes valve solenoid means actuated by said switch means for closing said electromagnetically operable control.
  • control means additionally includes first and second power wires, first, second and third relays each of said relays having one terminal connected to said first power wire, said first relay including a first contact that is normally closed, a second contact that is normally open and a third contact that is normally closed, said second relay having a first contact that is normally open, a second contact that is normally closed, and a third contact that is normally closed, said third relay having a first contact that is normally open and a second contact that is normally open, a signal source amplifier having an input signal source conductor connected to said feeler with said second contact of said first relay being interposed in said input signal source conductor between said feeler and said relay, first and second output signal lines extending from said signal source amplifier, said valve solenoid for operating said valve being connected across said first and second power wires in series with said first contact of said second relay, :1 first wire from said first relay connecting said first relay in series through said reed switch to said second power wire, conductor means connecting said third contact

Landscapes

  • Life Sciences & Earth Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Soil Sciences (AREA)
  • Environmental Sciences (AREA)
  • Fluid-Pressure Circuits (AREA)
  • Operation Control Of Excavators (AREA)
  • Earth Drilling (AREA)
US749117A 1967-07-31 1968-07-31 Machine for thinning and hoeing rows of plants Expired - Lifetime US3538985A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19671557705 DE1557705A1 (de) 1967-07-31 1967-07-31 Maschine zum Auslichten und Hacken von Pflanzenreihen mit mindestens einer drehbar angeordneten Werkzeugscheibe

Publications (1)

Publication Number Publication Date
US3538985A true US3538985A (en) 1970-11-10

Family

ID=5677292

Family Applications (1)

Application Number Title Priority Date Filing Date
US749117A Expired - Lifetime US3538985A (en) 1967-07-31 1968-07-31 Machine for thinning and hoeing rows of plants

Country Status (10)

Country Link
US (1) US3538985A (enrdf_load_stackoverflow)
AT (1) AT277632B (enrdf_load_stackoverflow)
BE (1) BE717869A (enrdf_load_stackoverflow)
DE (1) DE1557705A1 (enrdf_load_stackoverflow)
ES (1) ES356860A1 (enrdf_load_stackoverflow)
FR (1) FR1589102A (enrdf_load_stackoverflow)
GB (1) GB1230001A (enrdf_load_stackoverflow)
NL (1) NL6810785A (enrdf_load_stackoverflow)
SE (1) SE339585B (enrdf_load_stackoverflow)
YU (1) YU31667B (enrdf_load_stackoverflow)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
NL191227C (nl) * 1983-10-03 1995-04-03 Lely Nv C Van Der Grondbewerkingsmachine.
NL1004479C2 (nl) * 1996-11-08 1998-05-11 Rijkslandbouwhogeschool Actuator voor gebruik in een landbouwinrichting voor het uitvoeren van bewerkingen op rijgewassen.

Also Published As

Publication number Publication date
AT277632B (de) 1969-12-29
ES356860A1 (es) 1970-02-16
BE717869A (enrdf_load_stackoverflow) 1968-12-16
GB1230001A (enrdf_load_stackoverflow) 1971-04-28
YU31667B (en) 1973-10-31
YU177068A (en) 1973-02-28
NL6810785A (enrdf_load_stackoverflow) 1969-02-04
DE1557705A1 (de) 1970-04-02
SE339585B (enrdf_load_stackoverflow) 1971-10-11
FR1589102A (enrdf_load_stackoverflow) 1970-03-23

Similar Documents

Publication Publication Date Title
US2749824A (en) Laterally shiftable and tiltable rotary hoe
US4337959A (en) Self-leveling and height control hydraulic system
US3722193A (en) Automatic header height controlling mechanism
US3538985A (en) Machine for thinning and hoeing rows of plants
US4289256A (en) Tramlining device for seed drill
US3537531A (en) Automatic guidance apparatus for vehicles
US2178124A (en) Tractor power lift row marker
US2295898A (en) Side disk terracing machine
US3566587A (en) Header control system for mechanical cotton picking machine
JPS581881B2 (ja) 動力農機の走行制御装置
US2366155A (en) Power lift mechanism
US3503451A (en) Fluid actuated marker element for tractors and the like
US3006420A (en) Cultivator attachment for tractors
SE453873B (sv) Vendmekanism for delburen plog
GB888286A (en) Improvements in or relating to the control of implements by mechanically propelled vehicle
US2086350A (en) Control mechanism
US2197848A (en) Power lift attachment for tractors
US2409228A (en) Power lift
US2256593A (en) Harrow
US2221550A (en) Roll-over type dammer
US3005500A (en) Automatic retracting mechanism for agricultural machinery
US3458952A (en) Method of thinning plants
USRE22932E (en) Control means fob tractor
US2577351A (en) Remote motor control
RU2023356C1 (ru) Устройство для обработки почвы в рядах многолетних насаждений