FR2531303A2 - Device intended for improving the ground grip of tractors carrying soil-cultivating tools. - Google Patents

Abstract

Agricultural machines. Device for improving the ground grip of a tractor, characterised in that it comprises a gauge wheel 50 carried by an arm 51 mounted pivotably on an axle 52, elastic means 54, 54a and a switch 55 designed so as, when the arm 51 tilts in a direction corresponding to a vertical force exerted on the wheel 50, to shorten a jack inserted between the tractor and the third-point linkage and, on the contrary, when the force exerted on said wheel 50 is below a specific threshold, to lengthen the corresponding jack.

Description

The present invention relates to a device intended

  born to improve the grip on the ground of a tractor with a three-point lifting device located at the front

  or at the rear and on which an agricultural machine is attached

  cole provided with tools for working the soli said machine being, at its free end, supported by a wheel

gauge.

  The main patent application describes

  a device intended to be mounted on an assembly

  taking a tractor and tillage tools, said tractor being provided with a three-point lifting device comprising two lifting arms and a third point bar, while the tillage tools are provided, on the one hand , means for coupling them to the

  three-point linkage and, on the other hand, a gauge wheel

  ge partially supporting the working tools, the third point bar being constituted by a hydraulic cylinder

  while the gauge wheel is connected to means of com-

  actuator command, said hydraulic actuator control means

  being arranged so that in response to a vertical force applied to said gauge wheel, and exceeding a determined threshold, the actuator is shortened and that in response to a vertical force applied to said gauge wheel and located below of a determined threshold, the jack

either lie down.

  With such an arrangement, one can maintain in

  all working conditions a vertical load ap-

  folded to the tractor according to the vertical load

  carried by the gauge wheel and thus allow the tractor

  to work with its maximum capacity depending on the ef-

strong to provide.

  In the embodiment described in the patent

  main, the gauge wheel is supported by a bar

  vertically sliding tee in a sleeve of a support, said sleeve comprising a lateral tab supporting a guide rod of a compression spring, said rod passing through a tab integral with the bar, the compression spring being inserted between a stop of the rod and the lug integral with the bar, the latter lug being provided with a first electrical contact intended to cooperate with a fixed electrical contact when the force applied to the gauge wheel exceeds a determined threshold, these contacts being inserted on the circuit electric of a corresponding solenoid valve, and a second electric contact intended to cooperate with a fixed electric contact when the vertical force applied to the gauge wheel is located below a determined threshold, these latter contacts being inserted

  on the electrical circuit of a corresponding solenoid valve.

  However, it has been stated that such an embodiment, if it worked perfectly, did not adapt well to reversible plows. Indeed, when the plow is turned over, the assembly comprising the gauge wheel bar, the sleeve, the electrical contacts, etc had to rotate 180 ', but the control is necessarily electric and we must bring electrical wires from a generator to the contacts and the solenoid valves, so that these wires are subjected to

  twists which could quickly cause damage

wire management.

  One of the aims of the present addition is to provide a simpler device which is more easily adapted to

reversible plows.

  Another disadvantage of the realization of the main patent

  cipal lies in the fact that the device as it is

  designed does not directly adapt to existing agricultural machinery

  Another object of the invention is to provide a

  to remedy this drawback.

  Improvements to the devices intended to improve the grip on the ground of a tractor according to the main patent, said tractor carrying soil working tools, and being provided with a three-point lifting device comprising two lifting arms and a bar third point while the soil-working tools comprise a frame and are provided, on the one hand, with means for their coupling to the three-point lifting device and, on the other hand, with a gauge wheel supporting partly the tools at work,

  the third point bar being constituted by a hy-

  hydraulic while the gauge wheel is connected to means for controlling the hydraulic cylinder, said means for controlling the hydraulic cylinder being arranged so that in response to a vertical force applied to said gauge shaft and

  exceeding a determined threshold, the hydraulic cylinder is

  courcl and, that in response to a vertical force applied to

  said gauge wheel and situated below a determined threshold

  born, the hydraulic cylinder is elongated, and are characterized in that the gauge wheel is carried by a movable arm on

  an axis extending substantially perpendicular to the direction

  advancement of the machine, said arm being movable

  against the action of elastic means, said control means

  of hydraulic cylinder comprising a switch integral with the frame and arranged for when the arm rocks in a direction corresponding to a vertical force applied to the wheel and

  exceeding a determined threshold, close an electrical circuit

  that command so as to shorten the cylinder and, at the con-

  milking, when the force applied to the gauge wheel falls

  below a determined threshold extend the cylinder.

  Thanks to this arrangement, more mounting

  simple than that described in the main patent.

  According to yet another characteristic, the means

  rubber bands consist of rubber blocks.

  Preferably, and to allow an adjustment from which the length of the cylinder must be modified, the position

  rubber blocks is adjustable.

  According to a particular embodiment adaptable to a reversible plow, the device comprises a lug secured to the frame of the plow and supporting two rubber blocks arranged symmetrically with respect to a plane

  horizontal passing through the longitudinal axis of the frame of the

  street, two switches also arranged symmetrically and axially arranged to close a first circuit when they receive a thrust which exceeds a determined threshold and close a second circuit when this thrust falls below a determined threshold, a stop provided on the arm to cooperate with the corresponding switch in the plowing position and a contactor to open the general circuit of the switch used during plowing and close the general circuit

  on the other switch when turning over; ent.

  According to an alternative embodiment also suitable

  table with a reversible plow, the arm supporting the gauge wheel is inserted in a yoke with two wings and a core

  and having elastic pads inside its wings

  that cooperating with said arm and constituting the elastic means

  ticks while the soul supports the switch whose com

  control is ensured by a cam articulated on the core and connected to said arm, the Azant gauge wheel pivotally mounted on a

  support so as to be able to selectively occupy two positions

  tions offset by 1800 and means being provided for the ca-

1st in said two positions.

  In reversible plows, for transport, the gauge wheel is generally used, the plow being pivoted by 90 only, another characteristic according to the invention provides also to use the gauge wheel to support the plow in the transport position and for this purpose, the yoke is pivotally mounted so that it can be retracted while the support of the gauge wheel comprises means for wedging the gauge wheel in two

  positions angularly offset by 900.

  The invention will now be described in more detail with reference to particular embodiments, given by way of example only - and shown in the accompanying drawings, in which: Figure 5 schematically shows an embodiment of the invention adaptable to a reversible plow,

  Figure 6 is an enlarged view of an inter-

  breaker with overshoot of neutral position, FIG. 7 is a sectional view of a control switch, FIG. 8 shows the hydraulic diagram of the device, FIG. 9 shows the control diagram of the device, FIG. 10 is a perspective view of a alternative embodiment of the device according to the invention, Figure ll shows the electrical control diagram, Figure 12 shows the switch control cam, Figure 13 is a sectional view on a larger scale of a detail, Figure 14 shows in perspective, the gauge wheel in the transport position, figure 15 shows a detail of the mounting of the gauge wheel, in particular intended for reservable plows arranged

in front of a tractor.

  In Figures 6, 7, 8 and 9, there is shown an embodiment in which the gauge wheel which here bears the reference 50 is carried by a swinging arm 51 Le

  mounting particularly suitable for reversible plows.

  The swinging arm 51 is mounted on an axis 52 supported by the frame 53 of the plow, the latter comprising on the one hand, elastic stops 54 and 54 a and, on the other hand,

switches 55 and 55 a.

  The elastic stops 54 and 54 a are supported by a lug 57 having tapped holes 58 and 59 in which screws 60 and 61 are screwed respectively, these screws being integral with the elastic stops 54 and 54 a which are

  consisting of simple rubber stamps.

  Each switch 55 and 55 a (see FIG. 7) comprises a body 62 which has at one end a contact 63 against which a contact 64 which may be joined to abut d

  a rod 65 which passes through the body 62 through a hole 66 to make

  re protrudes outside, said rod supporting a second

  contact 67 likely to relate to a corresponding contact

  laying 68, a compression spring 70 being interposed between a stop 71 and the contact 67 so that the contacts

  67 and 68 tend to be applied against each other.

  On the arm 51, there is provided a stop 73 which is

  arranged in such a way that in a working direction of the char-

  street, it meets the rod 65 of the switch 55, while when the plow has been turned over, said stop 73

  meets the rod 65 of the switch 55 a.

  In FIG. 8, the hydraulic diagram of the arrangement of FIGS. 5 to 7 is shown. A tank 76 is provided, from which the oil can be sucked up by a pump 77 preferably actuated by the power take-off of the tractor. .

  The pump 77 is connected by a hose 78 to a distri-

  goalscorer designated as a whole by the reference 80, an Il-

  pressure monitor 81 being inserted on the circuit to pro-

  cover the operating members The distributor 80 Â includes a first position "I" in which the oil

  drawn by the pump 77 returns to the cover 76 by a cana-

  read 82 In a position "II" a jack 85 is supplied through a flow regulator 86, while in a position "II" the jack 85 is directly connected to the cover 76. On the feed circuit of jack 85, he is

  provided with a piloted non-return valve 87 which allows

  fix the cylinder in the position avoiding leaks This valve is released when the distributor is located in the

position "III".

  Cylinder 85 replaces in the lifting system

  three points, the third point bar.

  The distributor 80) is controlled by an electrical circuit shown schematically in Figure 9 It is

  provided a generator 90 to which the interrup-

  55 and 55 a with interposition of two low contactors

  bottom dead center 91 and 91 a.

  In FIG. 6, a contact is shown in detail.

  tor 91 or 91 a, these comprising a fork 92 whose ends carry contacts 93 and 94 intended to cooperate with corresponding contacts 95 and 96 The fork is conductive, articulated on an insulating pin 98 and integral with an insulating bar 97 A member 99 is provided to tend to maintain applying the contacts 94 and 93 against the contacts respectively 96 and 95 from a determined angular position when the strip 97 is biased in the direction of the arrow "f", and, for on the contrary tilt the fork 92 against a stop 100 when said

  bar is stressed in the direction of the arrow "g".

  The arm 51 carries a finger 102 arranged to reinforce

  counter when lifting the plow and controlling the turning, the bar 97 of the contactor 91 to cover the power circuit of the switch 55

  and, at the end of the reversal stroke, meet the bar-

  rette 97 of contactor 91 a to close the supply circuit of switch 55 a and vice versa when the

plow in the initial position.

  The operation of this embodiment is the

following: -

  The wheel 50 rests on the ground, the reversible plow being able to be pulled or pushed and it constitutes a gauge wheel. The plow is coupled to a three-point lifting system of a tractor whose third point bar is

  constituted by the hydraulic cylinder 85.

  The position of the elastic stops 54 and 54 a is adjusted by tightening or loosening the screws 60 and 61 so that the closing of the contacts 63 and 64 desits * the switches 55

  and 55 a correspond to a determined effort.

  The distributor 80 normally remains in the position

  "l" If the force applied to the wheel 50 exceeds a threshold

  mined, threshold defined by the position of the stop 54, the stop 73 pushes the rod 65 which closes the contacts 63 and 64 so

  that the distributor 80 is controlled and its drawer comes oc-

  cut position "II, with pressurized oil being admitted into cylinder 85 on the side of the piston rod so that the third point bar which is formed by said cylinder shortens Thus, part of the weight of the plow

  is automatically transferred to the tractor.

  If, on the contrary, the force applied to the wheel 50 becomes less than a determined threshold, the stop 73 tends to move away from the rod 65 and the contacts 67 and 68 close the circuit on the distributor 80 so that the latter this comes to occupy the position "IIIV, the oil contained in the jack 85 returning to the cover 76 In this case, the jack 85 lengthens and part of the weight of the plow is transferred to the wheel

50 gauge.

  As soon as working conditions return to normal

  males, the electrical circuits open and the distributor

  80 returns to its initial position "I".

  When the plow is turned at the headland

253 1303

  to return it, the arm 51 swivels on its axis 52 in order to

  come to bear against the elastic stop 54 a During this

  of said arm 51, the finger 102 meets the strip 97 of the contactor 91 so that the circuit of the switch 55 is open, said switch coming into a position

  in which its fork 92 bears against the stop 100.

  The arm 51 encounters during this tilting, the bar-

  rette 97 of the contactor 91 a which then comes to be placed in a position in which the circuit of the switch 55 a is

closed (see fig 9).

  During operation, the same process as that which has just been described continues and it is understood that, when the arm 51 returns to its initial position (fig 5) it will command the opening of the circuit of the switch 55 a

  and closing the circuit of the switch 55.

  In Figures 10 to 14, a further

  variant adaptable to a reversible plow.

  In this embodiment, at the free end of the frame 110 of the plow, a pivoted axis 111 is provided.

  in a bearing 112 and secured to an arm 113.

  The arm 113, at its free end, has a pin 114 whose free end supports a bush 115 in

  which is mounted a bar 116 whose free end sup-

carries a 117 gauge wheel.

  The bar 116 is pierced with two angularly offset holes

  900, while the socket 115 has a hole 118, intended to selectively coincide with the holes in the

  bar 116 so that by the selective engagement of a bro-

  che, one can wedge said bar in two positions offset by 900 The axis 114 can rotate freely in a bearing 120

  of the arm 113 and comprises a crown 121 provided with two

  checkmarks 122 offset by 1800 with which selectively cooperates

  tively a latch 124 articulated on an axis 125 carried by the

says arm 113.

  The frame 110 supports a sleeve 127 on which is

  ticule a clevis 128 comprising two cheeks 129 and 130 connected by a plate 131 The cheek 129 is integral with a ring 132 which can be brought into two angular positions to coincide with sockets 135 and 133 so, by the introduction of a spindle 134, to allow the setting of the yoke 128 in the chosen position.

  The cheek 129 has a groove 139 which is crossed

  seed by a screw 140 on which a nut 141 is screwed and which

carries a rubber block 142.

  The cheek 130 has a groove 43 which allows, by

  screw and nut, fixing a rubber block 144.

  On the plate 131 is fixed a switch 150 of the same type as that described in FIG. 7 and comprising a

  body 151 with contacts 152 and 153, a strip 154 sup-

  bearing contacts 155 and 156 and on which is engaged a spring 157 interposed between a stop 158 and the contact 155, said spring tending to apply the contact 155 against the

contact 153.

  On the plate 131 is articulated on an axis 161, a cam 160 extended by a finger 162 whose free end carries a wheel 163 movable in a rail 164 carried by the

arm 113.

  The hydraulic installation controlling the extension

  or shortening the third point arm, for example-

  ple, cylinder 85, is the same as that shown in figure 8, however, the control installation can be much more simplified (see figure 11) since the same switch can be used in the two angular positions of the plow

at work.

  It will be noted that the cam 160 is symmetrical with respect to

  port to a plane passing through the finger 162 so that the control of the switch 150 is identical in the two positions

  working angles of the plow.

  In operation, the arm 113 is inserted between the blocks 142 and 144 whose position along the slots 139 and 143 determines the settings of the thresholds from which the switch 150 must actuate a distributor such as the

distributor 80.

  If the force exerted on the arm 113 exceeds a threshold

  determined, cam 160 commands the closing of the feed circuit

  mentation of the actuator by closing the contacts 152 and 156

  so that the third point arm (jack 85) is connected

  shortened. If, on the contrary, the effort is below the threshold

  determined, cam 160 allows the closing of the cooling circuit

  turn to the tarpaulin of the oil of the jack 85 by closing the cir-

  electric baking corresponding to the control of the distributor 80 by the contacts 153, and 155 which are applied one against the other.

  When you rotate the plow, when turning

  ment, the latch 124 disappears from the notch 122 and the axis 124 then released, can rotate freely under the weight of the wheel 117 until the end of the reversal where the latch 124 then becomes housed in the notch 123 In this position, the system works in the same way as what has just been

  described The embodiment which has just been described previously

  feels the interest of being usable both for a trailed plow and arranged at the rear as for a pushed plow and arranged at the front The axis 111 is located in the first case, in front of the fulcrum the wheel 117 on the ground and in the second case behind In the case nd the point of

  support of the wheel on the ground is in front of the axis 111, we ob-

  holds the additional advantage that the rolling resistance

  ment are compensated by a higher reaction on the ground so that there is not generated a torque relative to the axis 111, torque which would risk causing a

  wrong switch command.

  The embodiment which has just been described may present an additional advantage for the transport of the plow. In fact, for the transport position, the plow is pivoted by 90, the gauge wheel having to support it. When the plow must be put in the transport position, the yoke 128 is tilted so as to release the arm 113, which can then freely tilt on its axis 111 At the time of the inversion, the axis 114 is placed vertically under the arm 113 and to place the wheel 117

  in a suitable position to support the load.

  street, just remove pin 119 and after doing

  turn the bar 116 in the socket 115 to reclave this

  the latter so that the wheel occupies the position shown in Figure 14 Thus, the wheel 117 which was offset from the arm 116 is centered, the lock 124 cooperating with the notch 122 ensuring the locking The wheel thus constitutes a wheel follower, the bar 113 being held in a

  direction perpendicular to the arm 116.

  In the case where the plow is a pushed plow,

  the reversal takes place in the opposite direction, that is to say

  re that the plowshares pass over the plow while in the pulled plows they pass-underneath In the pushed plows, it is therefore necessary to provide that the bearing 112 is integral with one end of a bar 170 whose other end is integral with a profile 171 The bar 170 is arranged so as to form with the profile 171, on the side

  of the latter adjacent to the frame 110 an obtuse angle.

  FIG. 15 schematically shows a plow pushed into the transport position For clarity, the yoke 128 has not been shown. It will be noted that, thanks to the arrangement which has just been described, in the position

  transport, the frame is horizontal.

  In the various embodiments which have been described, a single-acting cylinder was used, but one could provide a double-acting cylinder, the distributor

being arranged accordingly.

  In some cases, two plows can be provided

  one climb at the front and the other at the back of the same plot

  Each plow may include a device such as

  those just described which allows stabilization

  tighten the tractor-plow assembly by balancing the tans-

  front and rear charging ferts.

  Of course, the invention is not limited to

  embodiments which have just been described and represented

  We can make many modifications to it

  details without departing, for this, from the scope of the invention.

  Thus, for example, the electrical sensors could be replaced by equivalent means such as resistive piezo sensors, sensors operating by imbalance of a wheastone bridge or sensors operating by reserve

hydraulic pressure.

R E Y E N D I C A T I O N S

  1 Device intended to improve the adhesion to the ground of

  a tractor carrying soil working tools, said tractor

  teur being provided with a three-point lifting device comprising two lifting arms and a third point bar while the soil working tillage comprises a frame and are provided on the one hand, means for their coupling to the lifting device three points and, on the other hand, a gauge wheel (50) partially supporting the tools at work, the third point bar being constituted by a hydraulic cylinder (85) while the gauge wheel (50) is connected to hydraulic cylinder control means (85), said hydraulic cylinder control means (45) being

  arranged so that in response to a vertical force applied

  qué on said gauge wheel and exceeding a determined threshold, the hydraulic cylinder (85) is shortened, and, that in response to a vertical force applied to said gauge wheel (50) and located below a determined threshold, the hydraulic cylinder (85) is elongated, characterized in that the gauge wheel (50) is carried by an arm (51) movable on an axis (52) extending substantially perpendicular to the direction of

  advancement of the machine, said arm (51) being movable against.

  the action of elastic means (54) said control means

  hydraulic cylinder comprising a switch (55) solid

  daire of the frame and arranged for, when the arm tilts in a direction corresponding to a vertical force applied to the

  wheel and exceeding a determined threshold, close an electrical circuit

  control plate so as to shorten the jack (85) and, on the contrary, when the force applied to the gauge wheel

  falls below a determined threshold, lengthen the jack (85).

  2 Device according to claim l, characterized in that the elastic means consist of blocks

(54) rubber.

  3 Device according to claims 1 and 2, charac-

  that the position of the rubber blocks is adjustable

corn

  4 Device according to claims 1, 2 and 3,

253 1303

  and adaptable to a reversible plow, characterized in

  that it comprises, a tab (57) integral with the frame of the tank

  street and supporting two rubber blocks (54.54 a) arranged symmetrically with respect to a horizontal plane passing through the longitudinal axis of the frame of the plow, two inter-

  switches (55.55 a) also arranged symmetrically and arranged

  to close a first control circuit when they

* receive a thrust which exceeds a determined threshold and closes

  sea a second control circuit when this thrust falls below a determined threshold, a stop (73) provided on the arm to cooperate with the corresponding switch

  in the plowing position and a contactor (91) for or

  during the turnaround, the general circuit of the interrupt

  tor (55.55 a) which was used during the previous plowing and close the general circuit on the other switch (55.55 a)

  which will be used during the next plowing.

  Device according to claim 1, and adaptable to a reversible plow, characterized in that the arm (113) supporting the gauge wheel (117) is inserted in a

  clevis (128) with two wings (1-29,130) and a core (131) cor-

  carrying inside its wings elastic buffers (142,144) cooperating with said arm (113) and constitart the elastic means while the core (131) supports 1 switch (150) whose control is ensured by a cam (160 ) articulated on the core (131) and connected to said arm (113), the gauge wheel (117) being pivotally mounted on

  a support (116) carried by the arm so as to be able to

  lectively occupy two positions offset by 1800 and

  means being provided for wedging it in said two positions

-30 tions.

  Device according to claim 5-and adaptable to a reversible plow, characterized in that the yoke

  (128) is pivotally mounted so that it can be stepped

  driven tandfs that the support (116) of the gauge wheel (117) comprises means for wedging the gauge wheel in two

  positions angularly offset by 900.