FR2547972A1 - MACHINE FOR WORKING SOIL, IN PARTICULAR FOR PREPARING A SOWING - Google Patents

Abstract

THE INVENTION CONCERNS AN AGRICULTURAL MACHINE, IN PARTICULAR FOR THE PREPARATION OF A BED OF SEEDS, CONSTITUTED BY A ROTARY HARROW PLACED IN FRONT OF A ROLLER 10, WHILE AN INTERCEPTION BODY 23 INTENDED TO CRUSH AND SCATTER THE EARTH IS AVAILABLE BETWEEN THE EARTHS. WORKING BODIES 3 OF THE HERSE AND ROLLER 10 ACCORDING TO THE INVENTION, THE INTERCEPTION BODY 23 IS CLEARED BY SWIVELING UP AROUND AN AXIS LOCATED IN FRONT OF THE AA PLAN DEFINED BY AXES 2 OF THE WORKING BODIES 3 OF LA HERSE, WHEN THE CONSTRAINT EXECTED ON IT BY THE LAND MOVED BY THE SAID WORKING BODIES BECOMES TOO GREAT.

Description

The invention relates to a machine for working the ground, in particular for

  preparing a seed bed, comprising a plurality of working members, arranged in a frame part in a transverse row, in a direction of advance of the machine and which are driven around substantially vertical axes, while behind row of working members is arranged a roller which can be placed and immobilized in any one of several possible positions with respect to the frame part and that between the roller and the working members, is arranged a distributor member of oblong interception, which is during operation near the ground and extends over almost the entire width

  working of the machine, near the trajectories 15 described by the working members.

  In soil working machines of this type, the earth moved backwards by the working members, during operation, is divided and scattered laterally, so that a layer of soil, scattered in a substantially homogeneous manner and some thickness

is brought to the roll.

  It has been shown that during a massive inflow of land, the divider tends to move downward, which may not only disadvantageously influence the structure of the seedbed, but also

  undesirably increase the power required.

  The object of the invention is therefore to provide a machine for working the soil of the above kind, in which the problem

  recalled above is solved while maintaining the effectiveness of the oblong splitter.

  According to the invention this result is obtained because the splitter can rotate, during operation, around at least one axis located in front of the plane defined by the axes of rotation of the working members. oblong splitter member can deviate upward, if necessary, then the specific location of the axis avoids that the splitter takes a disadvantageous position for its

  action of division and scattering of the earth.

  In another of its aspects, the invention aims to provide an oblong distributor member which can pivot upwards during operation, while there is at least one means for offloading the weight of this organ. distribution unit, a facility of movement which ensures a regular operation of

  this organ even in adverse conditions.

  Another aspect of the invention relates to the support of the oblong splitter member with the aid of an articulated polygon, while the position of at least one of the axes of articulation of the polygon can be modified. can give the polygon a shape such that the erasure of the splitter becomes easier or less easy. Yet another aspect of the invention relates to the presence of means, with which the useful surface of

  the active part of the distribution unit can be modified.

  It is then possible, if necessary, to increase

  or to reduce the active part of said organ.

  Other objects and features of the invention

  will come out from the following description which refers to

  FIGS. 1 is a plan view of a machine for working the ground, in particular for the preparation of the device according to the invention.

  of a seedling, having a structure according to the invention.

  FIG. 2 is a section, on a larger scale,

  along the line II-II of Figure 1.

  FIG. 3 is a view similar to FIG. 2 with another structure of the support of the distributor member and

  a different realization of this organ.

  FIG. 4 is a view similar to FIG. 2 with a third embodiment of the support of FIG.

  the splitter and the structure of this body.

  FIG. 5 is a view similar to FIG. 2 of a fourth embodiment of the splitter

and its support.

  Figure 6 shows a fifth embodiment

  of the distributor member according to the invention.

  FIG. 7 represents a sixth embodiment of the distributor element according to the invention, the active part of this member being able to be modified. FIG. 8 is a partial plan view of a seventh embodiment of a distribution device according to the invention, with possible modification of the

active part of this body.

  Figure 9 is a section along line IX-IX

of Figure 8.

  Figure 10 is a partial view of an eighth

  embodiment of a distribution device according to the invention with an modifiable active part.

  Figure 11 is a view along arrow XI

of Figure 10.

  The device shown in the figures relates to a rotary harrow for working the soil, in particular

  for the preparation of a seedbed.

  The machine comprises a frame part 1 in the form of a box which extends transversely to direction A of the advance and in which rests axles 2 equidistant from 25 cm preferably, substantially vertical, which are part of working members 3 Each working members 3 comprises a substantially horizontal support 4 which is wedged on the end of the axis 2 protruding under the frame part 1, and which at its ends carries tools 5, extending downwards. and having the shape of teeth The lateral sides of the box 30 1 are closed by plates 6 substantially vertical and parallel to the direction A of the advancement The plates 6 extend rearwardly to overflow the frame part 1 and upwards to above this frame part 1 to a height at least equal to that of the frame part and preferably twice that height Near the front each of the plates 6 carries, at some distance above the frame part 1, a bolt 7 Around the bolt 7 oscillates, on the inner side, an arm 8 which extends rearwardly along the plate 6 Each of the arms 8 is bent down just behind the frame part 1 and then it is bent again, reverse assens, backwards The end of the arm 8 which extends backwards, is provided with a support plate 9,

  which extends obliquely backwards and downwards.

  Between the lower portions of the respective support plates 9 freely journalled a roll 10 which extends transversely to the direction A of the advance of the machine and has an axis of rotation substantially parallel to the vertical plane aa defined by the axes of rotation of the machines. Working members 3 At its periphery, the roller 10 is provided with longitudinal members 11 which are formed by tubes. Near the rear, each of the arms 8 is connected to a threaded rod 12, which is supported at the rear of the box 1 and with the aid of which the position of the roller can be adjusted In this way, the roller 10 can also be used to adjust the working depth of the working members 3 At the front of the frame part 20 in form of box 1 there is, at the height of the supports 4 of the working members 3, a protection 13, which extends over substantially the entire length of the box The protection 13 has the shape of a bar, which is, in this exemplary embodiment, a During operation, the guard 13 can pivot about an axis located near the front of the frame part 1, against the action of a spring. At the ends of the casing 1 are arranged, with the aid of arms 14, plates 15 which can pivot each about an axis, which extend conveniently in the direction A of the advance of the machine and which cooperate during operation, with the working members external, when in the position as shown in Figure 1 At some distance from each end of the box 1, at least to the height of the axis of rotation of the third work member 3, counted from one end of the row of working members, is fixed a plate 16 of form

  trapezoidal on the upper face of said casing 1.

  The plate 16, substantially vertical and parallel to the direction A - of the advance of the machine, is provided in front of the vertical plane aa defined by the axes of rotation of the working members 3, at a distance from this plane equal to about one-third half of the width of the casing 1, two pivots 17, 5 spaced one above the other (Figure 2) The pivots 17 are substantially horizontal and transverse to the direction A of the machine advancement Around each of the pivots 17 oscillate arms 18, respectively 19, disposed on either side of the plate 16 and extending rearwardly along the plate to after the rear face of the box 1 at the rear ends arms 18 and 19 are articulated about pivots 20 substantially parallel to the pivots 17, the substantially vertical portion 21 and extending downwardly of a support arm 22 for a plate-shaped distributor member 23 which extends over practically the entire working width of the machine and es The longitudinal axis of the member 23 is substantially parallel to the vertical plane aa defined by the axes of rotation of the working members 3 The longitudinal axes of the pivots 17 and 18 form the points articulated polygon hinge 24 which in Figure 2 is a parallelogram The position of the arms 18 and 19 is substantially horizontal The position of the arms 18 and 19 and therefore the position of the distributor member 23 relative to the organs 3 can be adjusted using a stop 25 constituted by a pin inserted into one of several holes 26 located one above the other and formed in the plate 16 On the upper edge of each plate 16 is attached, at the rear, a support 27 which extends upwards On its upper half, the support 27 is provided with a row of holes 28 In one of the holes 28 is hung an end of a coil spring 29, the other end is hooked into one of several holes 30 in one of the upper arms 18 and arranged in a row above the longitudinal axis of said arm and substantially parallel to this axis The coil spring 29 constitutes a means to unload the weight of the distribution unit whose application points can be modified

  by the choice of the holes 28 and 30 used and thus the importance of its action.

  The distributor member 23 is disposed at the end of a portion 31 which extends obliquely forwardly and downwardly from the arm 22, so that this member 23 is located near the trajectories described by the tools. At the lower face of the casing 1, the portion 31 is connected to the substantially vertical portion

  21 of the arm 22 The divider 23 consists of two parts, which are substantially the same width (FIG. 2).

  The upper portion 32 is substantially vertical during operation, while the lower portion 33 extends obliquely downward and rearward as

  As shown in FIG. 2, the two parts are flat. The arm 22 is fixed at the rear of the upper part 32.

  The upper pivot 20 around which the upper arms 18 of the polygon 24 are articulated on the upper portion 21 of the arm 22, can be introduced / one of several holes 34 located one above the other in the arm 22 and also in a second hole 35 in the arms 18 In FIG. 2, the pivot 20 considered in the central hole is arranged with three holes 34, situated one above the other, and in the hole back 35 arms 18 It is clear that a

  plurality of holes 30 and 35 may be provided.

  If the pivot 20 is disposed in the hole 35 of the arms 18 located further forward, the articulated polygon 24, which then has shorter upper arms 18, no longer forms a parallelogram In this way, we obtain that the organ 23 is erased more rapidly during the operation, which, if there is, for example, hard bodies can avoid damage. Also, the height position of the distributor member 23 is changed depending on the earth coming from the work 3, for

  modify the effect of division and scattering.

  Other variations of the articulated polygon 24 can be obtained by introducing the pivot 20 into a

other holes 34 of the arm 22.

  In the casing of the frame 1 is disposed on the axis 2 of each working member 3 a right gear 36 with all so that two neighboring wheels 36 are engaged Near the middle of the row of working members 3 the The axis of a working member is extended upwards to extend into a gearbox 37. In the gearbox 37, the extension is in driving connection, via a gear transmission. bevel gears, with an axis extending in the direction A of the advance of the machine and which, via a speed variator O 10 located at the rear of the gearbox, is in driving link with a susjacent axis 39 which also extends in the direction A of the advance and which projects in front, outside the gear box The end of the axis 39, which makes protruding outside the gearbox 37, can be coupled by means of an intermediate axis 40 to the axis d At the center of the chassis part 1 is a trestle 41 with

  attachment points for coupling to the three-point lifting device of a tractor.

  During operation, the machine is coupled with the aid of the bridge 41 to the three-point lifting device of a tractor and the working members 3 are driven from the tractor PTO axis 25 by the transmission described above in the directions indicated by arrows in Figure 1 During the advancement of the machine according to the arrow A, the bodies 3 work at least contiguous strips of land Before starting work, it is regulated - as already mentioned30 with the aid of the roller 10, the working depth of the members 3 After the position of the distributor member 23 is adjusted to the desired height by means of the stop, which can be used optionally also As a means of immobilization For the adjustment of the member 23, one of the arms 18 and 19, preferably the arm 18, may be provided with an extension acting as a handle instead of the adjustment represented by the stop 25, there may also be

  Continuous tuning, which allows great precision.

  The distributor member 23 is adjusted in such a way that its lower edge is above the level of the lower generatrix of the roller 10 (FIG. 2). The earth grasped by the respective working members 3 is moved between two members. according to the direction of rotation of these working members, alternatively

  from one pair to another, forwards and backwards.

  The initial cohesion of the earth is broken during the forward movement of the tools 5 of the working members, after which the earth is crumbled more by the tools during their rearward movement which projects it fan back The big elements are projected further than the smaller elements, so that it is the larger elements which come into contact with the substantially vertical part 32 of the interception member located near the working members (FIG. 2), they are crumbled and scattered along this member, all so that a homogeneously crumbled layer of soil is gradually fed to the roller 10 by the lower edge of the portion 33, extending obliquely rearwardly; and downwards, of the interception member With the aid of the longitudinal elements 11 of the roll 10, a subsequent crumbling and also local compression is optionally obtained.

  the layer of soil that increases its resistance to erosion.

  The roll 10 which can be made as a packer roll also maintains, as much as possible, the position of the member 23, and thus, the thickness of the layer fed to the roll remains substantially constant. As already mentioned, the distributing and intercepting member 23 can be erased during operation by virtue of the presence of the weight-relieving means in the form of the coil spring 29 and the presence of the polygon. articulated 24, while the manner in which this erasure is effected is influenced by the choice of holes 34 and 35 used Thus, it can be said as aforesaid to obtain a faster erasure of the organ of interception by using the hole before the arms 18, while using the holes 34, another variation can be obtained The possibility of erasing the interception member, obtained using the articulated polygon 24 and load shedding means, contributes to a large extent to the regularity of the evacuation of the earth, coming from the working members and thus allows to draw the optimal effect of this interception splitter body. Although this is not represented, the body

  23 may also be composed of spaced or contiguous plates.

  FIG. 3 shows another embodiment of the invention, the parts similar to those of the preceding example being indicated with the same reference numerals. In this embodiment, the trapezoidal plates 16 are replaced by plates 42 which extend higher up front than rear; this in connection with the fact that the upper arms 18 of the articulated polygon are replaced by a single arm 43 formed by a rod 44, which can move in a cylinder 45 against an elastic means The free ends of the rod 44 and cylinder 45 are extended by a fork 46, 47 respectively, which around the pivot 20, respectively 17, are hinged as in the previous embodiment,

  on the support arm 22 and respectively on the plate 42.

  In the position shown in Figure 3, the articulated polygon 48 is a parallelogram, the arms 19 and 43 being substantially horizontal The upper side of the cylinder 45 carries two lugs 49, slightly spaced, between which is attached one end of a pneumatic damper 50, whose other end is articulated to the upper part of the plate 42 between two lugs 51, to form a shedding means Although not shown a possibility of adjustment of the damper 50 may be provided, similar to that of the spring in coil 29 of the previous example. The interception member 52 comprises, in this embodiment, also an upper portion 32, substantially vertical, which is fixed rigidly on the support arms 22 In this embodiment, the lower portion 53 is bent at its base, towards the rear, in an arc of about 180, the free edge thus being above the ground On the sides, the lower portion 53 is provided with side plates 54 which extend in the direction A of advancement Each of the plates 54 has a leading edge that extends from above, downward and forward and backward, which extends from top to bottom and back. The obliquity of the rear edge is larger than that of the front edge The edge

  The bottom of the plates 54 is connected to the front and back edges by rounding, as shown in FIG.

  The structure according to FIG. 3 of the interception member 52 makes it possible to collect in the same manner as in the preceding example of embodiment, the larger elements which are displaced backwards by the working members. The bottom curved lower end of the interception member has a larger contact plane with the earth to be discharged and the thickness of the layer of soil brought to the roller may be smaller. The presence of plates 54 disposed at the ends of the member 52 prevents large volumes of soil from being worked, that part of the earth escapes out of the ends of this body, which could cause irregularities in the seed bed. embodiment if the stress on the interception member 52 exceeds a certain value, the rod 44 which is part of the upper arm 43 enters the cylinder 45 against the elastic effect, the articulated polygon 48 is The "response time" of the erasure can also be reduced by using the second hole 35 to introduce the pivot 20 to give the polyg. in an initial configuration, which differs from a parallelogram The pneumatic damper 50, as a means of

  shedding requires relatively little maintenance.

  In the embodiment shown in FIG. 4, there are parts identical to those corresponding to the first exemplary embodiment and they bear the same references. In this exemplary embodiment, the arms 18 and 19 of the articulated polygon 24 are located at 1 in this way, a parallelogram position can be obtained in which the interception member can deviate more rapidly than when the Parallelogram arms extend substantially horizontally. Furthermore, with the plurality of holes 34 and 35 in the support arm 22 and the arms 18, a polygon can be created, which differs from a parallelogram and thus obtain the effects described above. . In this exemplary embodiment, the interception splitter 55 comprises a support 56, which extends transversely to direction A of the advance and is substantially parallel to the vertical plane aa defined by the axes of rotation of the working members 3. With the aid of gussets 57, is fixed to the support 56 a plate 58 which extends obliquely downwardly and rearwardly. The lower part of the plate 58 is provided with a flexible part 59 which is preferably made The intercepting member 55 thus formed is particularly suitable for use on fields where a lot of stones and other hard elements meet in the ground. The position of the plate 58 and the presence of the elastic piece 59 can prevent damage to the working members and the interception member This interception member is

  also less sensitive to the grip of the earth.

  In the exemplary embodiment shown in FIG. 5, there are arranged on the upper face of the box-like frame part 1 relatively low trauma plates 60. On either side of the plates 60 are articulated around a pivot 61, located with respect to the plane aa at the same location as the pivots 17 of the previous embodiments, arms 62 which extend along the plates 60 towards the rear. beyond the rear face of the frame part 1, a distance which is substantially equal to that on which the arms of the preceding embodiments of the arms extend.

  the support arms 22 are fixed for an interception member 63.

  On the arms 62 is hooked a shedding means, which is formed by a coil spring 29, arranged in the same manner as the coil springs of the first and third embodiments for the arms 62, there is also a stop constituted by pin 25

  which can be adjusted as in the previous examples.

  The interception member 63, in this embodiment, corresponds substantially to that of the first embodiment (FIG. 2), but here the lower portion 33 is provided, at the front, with an elastic material 64, for example rubber This elastic material 64 avoids damage by hard objects such as stones, and adhesion

  possible earth at the lower part of the organ 63.

  FIG. 6 shows an interception member 65 which can be used with the structures described above. This member 65 comprises a transverse bar 66 in the direction A of the advance of the machine and formed by a tube. Bar 66 is suspended a second bar 66 by means of links 67. Below the second bar 66 is suspended, by means of links 67, an angle 68. The whole forms a flexible member, which can by its great mobility, a crumbling and scattering of the collected soil The collected and worked soil is brought to the roller 10, in the case of this organ 65, mainly over the upper ridge

from the lower bar 68.

  The interception member 69 shown on the

  FIG. 7 may also be used with each of the supports described and shown in FIGS. 1 to 5. In the interception member 69, there is a transverse bar 70 in the direction A of the advance and substantially horizontal.

  The bar 70 is tubular and fixed to the respective carrier arms 22 and is provided with teeth 71, substantially equidistant and extend downwards. The teeth 71 are rigid, but could also be resilient or resiliently fastened. In this embodiment, one of two of the teeth 71 can be moved upwards and can be immobilized by means of a clamping bolt 71 A, to give the organ 69, at will, a larger or smaller active part and thus obtain a scatter and

  a more or less intensive crumbling of the collected earth.

  In the exemplary embodiment according to FIGS. 8 and 9, the active part and consequently the scattering and crumbling power of the interception member 72 is adjustable thanks to a structure in which two bars 73 and 74 tubular are spaced one behind the other Each of the bars 73 and 74 is provided with rigid teeth 75 extending downwards Again, instead of rigid teeth, one can provide elastic teeth or elastically fixed bar The bars 73 and 74 are arranged so that they can be moved relative to each other (FIG. 8) by means of articulated links 76 which are arranged near the ends of the bush. lower side and the upper side With a pin 77 which can be inserted into a hole of the upper link and one of a plurality of holes 78 A formed in a plate 79 fixed rigidly to the back of the bar before 73, the upper link 76 and consequently the rod 74 can be immobilized in one of several possible positions with respect to the front bar 73 With this adjustment, the teeth 75 can be set from a certain position, by example from where they are approximately in the axis of the teeth of the front bar 73 in another position, in which they are arranged out of this axis, all so that the active part and so the effect of scattering and crumbling of the member 72 is modified. The active part 30 of the interception member 78 can also be modified in the structure shown in FIGS. 10 and 11. Two bars 79 and 80 each formed by one tube are arranged one above the other and the teeth 75 of the bar

  upper through the lower bar 80 in holes 35 formed between the teeth 75 of the lower bar 80.

  The lower bar 80 is connected to the respective support arms 22, while the upper bar 79 is provided at each end with a pin 81 engaged in an oblong slot 82 formed in a substantially vertical plate 83 attached to the corresponding end. of the

  Each of the journals 81 is threaded at its free end to receive a wing nut 84.

  By the choice of the locking position of the journals 81 in the grooves 82, the upper bar 79 is arranged more or less at the top, and the passage between the teeth 75, under the lower bar 80, is larger or smaller which It is possible to regulate the crumbling and scattering action of the interception member. Here again, it is possible to provide resilient teeth or elastically fastened teeth. Furthermore, in this embodiment and also in the embodiments according to FIGS. at 9, the teeth can extend obliquely downward and towards

  the back instead of being substantially vertical.

Claims (19)

  1 machine for working the soil, in particular for the preparation of a seed bed, comprising a plurality of working members, arranged in a box-shaped frame part in a transverse row in the direction of the machine advancement and which are driven about substantially vertical axes, while behind the row of working members is disposed a roll which can be placed and immobilized in any one of several possible positions with respect to the frame part and that between the roller and the working members, there is disposed an oblong interceptive splitter member, which is close to the ground during operation and extends over substantially the entire working width of the machine, close to the paths described by the working members, characterized in that, during operation, the oblong interception member (23, 52, 55, 63, 65, 69, 72, 78) is pivotable about at least one axis the plane (a-a) defined by the axes of rotation (2) of the working organs (3).   2 Machine for working the soil according to the   claim 1, characterized in that there is at least one means (29) of load shedding of the weight of the interception member (23).   3 machine for working the soil according to claim 2, characterized in that the load shedding means is constituted by a spring (29) which is arranged between a support arm (18) of the interception member (23) and the   box-shaped frame part (1).   Flooring machine according to one of the preceding claims, characterized   in that the oblong interception member (23) is connected to the frame part (1) at two spaced points by an articulated polygon (24) whose hinge axes extend transversely to the direction (A) the progress of the machine. 35 5 Machine for working the soil according to one   any of claims 1 to 3, characterized in that   the interception member (63) is hingedly connected to the frame part (1) by two spaced apart oscillating arms (62) extending over at least one   part of said frame part.   6 machine for working the ground according to claim 4, characterized in that the position of at least one of the articulation axes (20) of the articulated polygon (24) can be changed.   7 machine for working the ground according to claim 6, characterized in that the articulated polygon (24) has four axes of articulation (17, 20) and the position of at least one of the upper axes of articulation (20) can be changed.   8 machine for working the ground according to claim 6 or 7, characterized in that the articulated polygon (24) comprises two arms (18, 19) located one above the other, which extend in the direction (A ) of the advance of the machine and are articulated on the one hand on the frame part (1) and on the other hand to a support arm 20 (22) of the oblong interception member (23) and that there are means by which the useful length of the arm   higher (18) can be modified.   9 machine for working the ground according to claim 8, characterized in that the articulation between the upper arm (43) and the frame part (1), respectively the support arm (22), can be moved   in the longitudinal direction of the upper arm.   Machine for working the soil according to the   Claim 9, characterized in that the joint can be moved against the action of an elastic means.   11.Machine to work the soil according to one   any of claims 8 to 10, characterized in that   that the articulation between the upper arm (43) of the articulated polygon (48) and the carrying arm (22) of the interception member (52) can be moved in the longitudinal direction of the upper arm (43).   12 Machine for working the soil according to one   any of claims 8 to 11, characterized in that   that the arms (18, 19) of the articulated polygon (24) extend from their articulation on the chassis part (1),   obliquely backward and downward.   13 Machine for working the soil according to one   any of claims 4 to 12, characterized in that   a stop (25), whose height position can be adjusted, limits the downward movement of the interception member (23, 52, 55, 63). 14 Machine for working the soil according to one   any of the preceding claims, characterized in that the oblong interception member (23, 63) is plate-shaped and comprises a substantially vertical portion (32) and an obliquely extending portion (33). down and back.   Machine for working the soil according to claim 15, characterized in that the respective parts (32, 33) of the interception member (23, 63) are connected   to each other near the middle of said organ.   16 Machine for working the soil according to one   any of the preceding claims, characterized in that the oblong interception member (55) is, at least partially flexible.   Floor-tilling machine according to Claim 16, characterized in that the flexible part (59)   the interception member (55) is at the bottom of this member.   Flooring machine according to Claim 16 or 17, characterized in that the flexible part   (59) is constituted by an elastic material.   The soil cultivating machine according to any one of claims 1 to 13, characterized in that   the oblong interception member (65) comprises a plurality of bars (66) arranged one above the other and connected to each other   one to another by flexible links.   Machine for working the soil according to the re35 vendication 19, characterized in that the flexible connection   is formed by chain links (67).   21 Machine for working the soil according to one   any of the preceding claims, characterized in that   what are the means by which the useful surface of the active part of the interception device   oblong (69, 72, 78) can be changed.   Machine for working the soil according to any one of claims 1 to 13, characterized in that the oblong interception member (69) comprises at least one   carrier member (70) which is provided with teeth (71) and that one of two of these teeth, for example the teeth of even rank,   can be put in an inactive position.   Machine for working the floor according to any one of claims 1 to 13, characterized in that   that the oblong interceptor (72, 78) comprises two bearing bars (73, 74 or 79, 80) provided with teeth (75) and arranged close to one another so as to be able to   be moved relative to each other.   Floor-tilling machine according to Claim 23, characterized in that the carrier bars (73, 74) can be moved in the longitudinal direction one with respect to the other.   Soil working machine according to Claim 23, characterized in that the carrier bars (79, 80) can be displaced in height by one report to the other.   26 Machine for working the soil according to one   any of claims 22 to 25, characterized in that   the teeth (75) are made of an elastic material.