reference is made to the drawings to describe an advantageous embodiment example , though in no way restrictive , of the leaf stripping machine according to the invention . though reference is made , in the following portion of the present document , solely to the use of this leaf stripping machine in order to make a leaf stripping machine specifically for the vine , it is obvious that such a usage is not restrictive and that this machine can be used in order to perform leaf stripping of other plants cultivated in the form of aligned shrubs . this leaf stripping machine is of the type described in the document fr - 2 , 808 , 964 a . it consists of at least one leaf stripping head or module 1 comprising a rotary aspirating drum 2 consisting of an opened cylindrical wall 3 . in a preferred manner , the leaf stripping machine consists of two leaf stripping heads or modules 1 designed to be placed on both sides of the vegetation of the vine row , during work , in a manner so as to fit tightly around the fructiferous zones , all along its movement from one end of the row to the other . the opened drum has , for example , a height of between 400 mm and 800 mm , according to the leaf stripping models , and a diameter on the order of 450 mm . an aspirating turbine , for example , comprised of a helicoidal vacuum generator 4 activated by a hydraulic motor m 1 , is installed above the drum 2 , in order to create a partial vacuum inside the drum , which generates an intake flow going through the opened lateral wall of the drum , causing the “ gluing ” of leaves of vegetation layer on the opened wall or grid of the drum . inside the drum 2 , affixed and housed near the opened lateral wall 3 of the drum , is a mechanism for channeling the flow of air , this mechanism being advantageously comprised of a baffle 5 , having a shape that is determined in order to optimize the efficiency of the aspirating system . this baffle 5 comprises a lateral wall 5 a and a base 5 b by the intermediary of which it is rigidly connected to a lower horizontal element 6 a of the frame 6 of the leaf stripping head , for example , by means of an axle 7 supporting the lower bearing 8 that ensures the rotational guidance of the drum 2 . an opening 9 is arranged in the lateral wall 5 a of the baffle . this opening extends , for example , over a height that is approximately equal to the height of the opened lateral wall 3 of the rotary drum and has a width on the order of 220 mm to 260 mm corresponding to an arc on the order of 70 ° to 80 °. the major part of the area corresponding to the width of the opening 9 is arranged behind a diametral plane p - p of the opened rotary drum 2 perpendicular to the axis of movement x - x of the leaf stripping head 1 during work , as fig1 and 17 show . the opening 9 of the baffle 5 is arranged near the opened cylindrical wall 3 of the rotary drum 2 , in a manner so that the baffle ensures , on the one hand , the waterproofedness over a large part of the circumference of the opened drum , and , on the other hand , it channels , inside the drum , the air sucked in by the opening 9 . it is understood that the air sucked in by the turbine 4 is channeled in the form of an intake flow that goes through a varying portion of the rotating cylindrical wall , the positioning and dimensions of this portion of the opened wall corresponding approximately to those of the opening . the opening 9 and the portion of the opened wall passing by which is in front of it thus comprise an intake vent arranged in a zone of the drum designed to be in contact with the vegetation layer of the vine row . according to this principle of aspiration of the leaves by direct contact with the vegetation layer , it appears that the partial vacuum flow necessary in order to catch and pin the leaves against the opened cylindrical wall of the drum can be relatively weak relative to the leaf stripping machines of other types that stay relatively far from the vegetation layer , which requires a very sizeable partial vacuum , thus much power in order to suck in the leaves into the cutting section . the fixed baffle 5 has , laterally , an approximately cylindrical shape . in the principle of the rotary contact cage , the intensity of the leaf stripping is proportional to the partial vacuum generated by the intake . the volume of the leaves cut can thus be regulated as a function of the vacuum force of the fan . this regulation of the vacuum force can , for example , be done either by making the speed of rotation of the turbine vary , or by slowing down the air output of the turbine . the leaves are adhered by the vacuum on the cylindrical grid of the rotary drum . under the combined effect of the pneumatic suction and the mechanical rotation of the drum , the leaves are pulled from the vegetation layer . the leaves , lighter than the grapes , also provide a larger surface for suction , in a manner such that a relatively weak partial vacuum , due to the density difference , is sufficient to “ glue ” the leaves against the opened lateral surface of the rotary drum , without necessarily attracting the grapes . a cutting mechanism is installed near the mouth of the suction 9 of the rotary drum , in parallel or approximately parallel to the axis of rotation a - a of it . the cutting mechanism can be advantageously comprised of an alternating cutting bar 14 consisting of a mobile blade 14 a and a fixed bed knife 14 b , or a linear movement cutting bar , or of any other device . the cutting bar 14 is oriented in a manner so as to form an angle of ± 45 ° and , preferably , an angle on the order of 20 ° with a radius of the rotating intake drum 2 passing by the active edge of the cutting bar . it extends , preferably , over a height corresponding to the height of the opened lateral portion of the drum that has the vacuum flow passing through it . a rigid , horizontal shaft in the form of a ski 38 is fixed on the lower part of the structure of the leaf stripping head ; this shaft extends in front of the lower end of the cutting bar 14 , in order to protect it , for example in case of an encounter with a very twisted vine stock . according to a significant characteristic arrangement of the invention , the lateral wall 3 of the rotary drum 2 is comprised of a flexible material permeable to the air current . this flexible material permeable to the air current can be advantageously comprised of a metallic fabric formed from a multitude of meshes or interlaced metallic rings . a flexible metallic fabric of this type is generally designated by the name “ coat of mail ”. the small rings that comprise this metallic fabric have , for example , a diameter on the order of 4 mm and a thickness on the order of 5 / 10 mm . the upper and lower edges of this flexible opened lateral wall 3 are affixed to circular upper end elements 10 and circular lower end elements 11 , respectively , these end elements being made in a semi - rigid deformable material such as , for example , rubber , polyurethane , or other semi - rigid plastic deformable material . the opened drum thus made is suspended , with a rotational capacity , by the intermediary of its upper end element 10 and contact rollers 12 , on the case 13 enclosing the intake turbine 4 . the upper element 10 of the drum 2 is , for example , united in rotation with a circular track 10 a that moves over the contact rollers 12 on vertical axles mounted on the cylindrical wall of the case 13 , and subjected to the action of elastic pressure mechanisms against the track . a spring 45 acting by compression and arranged around the vertical axis 7 is interposed between the bottom 5 b of the baffle 5 and the lower guide bearing 8 of the drum 2 , comprising an element of the base vertically mobile from it in order to extend the coat of mail 3 in the vertical direction . the parts 5 c , 5 d of the baffle that define the aspirating mouth of the turning drum 2 , rub against the internal surface of the lateral wall 3 of the drum . for this purpose , at least the parts 5 c , 5 d of the baffle 5 are made of a flexible material . in an advantageous manner , the baffle 5 can be made of a flexible material , such as , for example , an impermeable cloth affixed to a rigid or semi - rigid frame . according to another characteristic arrangement of the invention , a supplementary mechanism for pulling leaves is arranged behind the cutting mechanism 14 taking into consideration the direction of movement of the leaf stripping machine , during work , or , more specifically , the reverse direction to the direction of rotation of the turning drum 2 of the leaf stripping head of the machine . in advantageous manner , this supplementary pulling mechanism can be comprised of a rotary feeder 16 tangent to the lateral wall 3 of the drum 2 and coupled to a rotational drive device , this rotary feeder being arranged in parallel to the cutting bar 14 and set back from it relative to the vegetation during work . this rotary feeder 16 consists , for example , of an axle 16 a , along which vertical flexible blades 16 b are affixed , oriented radially or at an incline from front to back considering the direction of rotation of the axle . the rotary feeder 16 is arranged next to the cutting bar and it is located in contact with the flexible side wall 3 of the drum 2 , or very close to it ( the maximum spacing being on the order of 8 mm ). the rotary feeder 16 and the aspirating drum 2 are driven in rotation in the opposite direction and “ downstream ”. the leaves pinned on the opened lateral wall of the rotating drum 2 under the action of the partial vacuum created by the turbine 4 are then found to be pinched between the wall and the feeder and pulled towards the rear of the drum . the pinching combines with the intake vacuum to keep the leaves pinned against the lateral wall of the drum , in order to improve the pulling of the leaves , which are detached when their petioles are cut by the cutting bar . according to an embodiment mode of the invention , a comb 15 can be arranged in parallel and in front of the cutting bar , considering the direction of the movement of the leaf stripping machine ( arrow f 1 ), or , more specifically , the direction opposite the direction of rotation ( arrow f 2 ) of the rotating drum , during work ( fig1 ). this comb 15 comprises a plurality of stacked horizontal teeth or barrettes , slightly spaced , the spacing between the teeth being , for example , on the order of 5 to 15 mm . preferably , this comb 15 is replaceable and it is , for example , affixed in a manner so that it can be removed on the fixed bed knife 14 b of the cutting bar . in this way , it is possible to rapidly mount a comb whose spaces between teeth are adapted to the condition of the vegetation , which can be very variable as a function of the time of the leaf stripping or the variety of the grape . the rotational driving of the drum 2 is done using a vertical roller motor 17 and a counter - contact roller having a vertical axle 18 or a pair of counter - contact rollers 18 ′ with the parallel vertical axles mounted with the ability to pivot around a vertical axle , in the manner of a bogie ( fig1 ). the roller motor 17 is arranged outside the drum 2 while the counter - contact roller 18 or the pair of the counter - contact rollers 18 ′ is placed inside the drum . the flexible opened lateral wall 3 of the drum is pinched between the roller motor 17 and the counter - contact roller 18 , or the pair of counter - contact rollers 18 ′ in a manner so that starting the rotation of the roller motor has the effect of driving in rotation the drum 2 suspended by means of the contact rollers 12 . the counter - contact roller 18 or the pair of counter - contact rollers 18 ′ is subjected to the action of elastic pushing mechanisms 37 which hold it permanently under pressure against the internal surface of the flexible lateral wall 3 of the drum which is thus found to be held constantly applied against the drive roller 17 . a flexible vertical flap 39 affixed to a rigid vertical element 40 of the frame of the leaf stripping head can be arranged behind the pulling roller 16 , in order to prevent the cut leaves or vine shoots from being able to be taken between the roller motor 17 and the lateral wall 3 of the drum 2 . the driving in rotation of the rotating drum 2 ; the operation of the cutting bar 14 ; and the driving in rotation of the feeder 16 . this common motorization consists of , for example , a hydraulic motor m 2 whose output shaft 19 is coupled to the vertical shaft 20 of an eccentric 21 whose connecting rod 22 is coupled , by the intermediary of a ball joint 23 and a link 24 to the upper end of the blade 14 a of the cutting bar 14 . in this way , the starting of the rotation of the shaft 20 of the eccentric 21 ensures an alternating longitudinal movement of the blade 14 a of the cutting bar . the lower end of the vertical shaft 20 of the eccentric is connected , for example , by the intermediary of a coupling shaft 25 , to the upper end of the axle 16 a of the rotary feeder 16 . it is understood that starting the rotation of the shaft 20 of the eccentric 21 also ensures the rotation of the feeder 16 arranged in the axial extension of the shaft . the motorization consists of another vertical shaft 26 arranged at a distance from the vertical coupling shaft 25 and connected to this shaft by a transmission , comprised of , for example , a flexible strap wound around the wheels set on these shafts 25 , 26 , respectively . preferably , this transmission comprises a belt 27 wound , on the one hand , on a pulley 28 set on the coupling shaft 25 , and , on the other hand , on a pulley 29 set on the shaft 26 whose lower end is coupled to the upper end of the vertical axle 17 a of the drive roller 17 . the receiving pulley 29 has a diameter approximately equal to or slightly greater than that of the driving pulley 28 , in a manner so that when the shaft 25 is set into rotation , the shaft 26 is driven in rotation at a speed approximately equal to or slightly slower than that of the shaft 25 . in other words , the tangential speed of the rotating feeder 16 is at least equal to the tangential speed of the drum 2 , or slightly greater than that of the drum . on the other hand , the rotational speed of the drum 2 is equal to or approximately equal to the speed of movement of the leaf stripping machine during work . if you consider that the drum ( s ) 2 of the leaf stripper roll ( s ) over the vegetation v , an immobile contact of the drum ( s ) relative to the vegetation results at a time t . thus , there is no friction between the leaf stripper , the bunches of grapes and the lateral wall 3 of the drums . the motorization described above is housed in a case 30 affixed , laterally , to an upper element 6 b of the framework of the leaf stripping head . the vertical shafts 20 and 26 are mounted so as to rotate in the bearings 31 and 32 , respectively , installed in the case 30 . according to another characteristic arrangement of the invention , the leaf stripping head comprises a servo system that enables , at its leaf stripping head 1 or at each of its leaf stripping heads or modules 1 , to follow the profile of the vegetation layer while regulating the contact force of the drum ( s ) 2 on the vegetation layer , in order to not crush the grape bunches . in the case of a leaf stripper equipped with two symmetrical leaf stripping heads , each leaf stripping head is controlled independently of the other one . the servo control consists of at least one sensor 33 housed inside the rotating drum 2 , near the flexible opened lateral wall 3 of the drum . in an advantageous manner , several stacked sensors are positioned inside the rotating drum 2 , preferably at an equal distance from each other , the extreme sensors ( upper and lower ) of this vertical alignment being arranged at a distance from the upper and lower edges , respectively of the opened lateral wall 3 . the sensors 33 can be advantageously comprised of sensors using the hall effect installed affixed and coupled to the stacked sensors 42 a , 42 b , 42 c , 42 d , . . . placed in contact with the flexible opened lateral wall 3 of the drum 2 . each sensor 42 is , for example , comprised of a contact shaft with a curved shape supporting a magnet that acts together with the hall effect sensor 33 to which this sensor is connected , in a manner so that the movements of this sensor 42 are detected and measured by the sensor 33 . as a result , the sensors 33 make it possible to detect and measure the deformations of the flexible lateral wall of the drum , resulting from the encounter of obstacles or an abnormal pressure of the leaf stripping drum on the vegetation . they make it possible to activate the electromechanical instruments or other instruments that control the positioning of the leaf stripping drum relative to the vegetation or vegetation layer v , and , as a result , to correct the position of the drum and ensure a continuous following of the vegetation layer . the flexibility of the lateral wall 3 makes it possible to press on each sensor 42 a , 42 b , 42 c , 42 d , . . . , over a distance on the order of 60 mm . the leaf stripping head or each leaf stripping head 1 of the leaf stripper is carried by a frame 36 , making it possible to mount it behind ( fig1 and 2 ) or in front of a farm tractor . it is suspended in a pendulum - like manner , for example , by means of an articulation by a horizontal axle 46 , connecting a vertical element of its frame 6 to a vertical element of the frame 36 ( fig3 ). this carrier chassis 36 is ( in a manner that is itself known from the prior art ) constructed and equipped with mechanisms that make it possible : to move apart or move together the leaf stripping head or each leaf stripping head 1 , relative to the movement axis y - y of the leaf stripper , the mechanisms advantageously comprising a deformable suspension parallelogram 36 a made by an upper part of the chassis ; and to regulate the position of the leaf stripping drum ( s ) 2 relative to the vertical ; these movements being controlled by the servo system as a function of the information transmitted by the sensors 33 . the servo system consists of another activator 41 , for example , comprised of an electric jack provided with an electronic board 43 for management of the servo control using an algorithm that makes it possible to determine successive deformations of the flexible lateral wall of the drum as a function of the instructions sent by the sensors 33 . a potentiometer 44 makes it possible to adjust this information in order to regulate the pressure of the leaf stripping module on the vegetation . the electronic board 43 sends the information to the activator 41 which acts on the deformable parallelogram 36 a on which the leaf stripping head 1 is suspended , or each leaf stripping head ( 1 ), in a manner so as to obtain an optimum position of the leaf stripping drums 2 relative to the vegetation during work . a potentiometer 45 coupled to the main axis of the parallelogram limits the minimum and maximum distance of the jack . according to this servo system , an intermediate pushed - back position of the sensors is defined to correspond , for example , to a pushed - in position on the order of 20 mm and at this position , the leaf stripping head maintains a stable position ; a more sizeable pushed - in position of the sensors drives a pulling back of the leaf stripping head , while the relaxation of pressure on the sensors drives the movement of the leaf stripping head and its application against the vegetation layer . the sequential representation of fig1 shows this functioning . on the left of the drawing , the pressure of the vegetation against the lateral wall of the drum 2 of the leaf stripping head 1 is normal , the sensors are moderately pushed - in , the position of the leaf stripping head is stable . in the center of the drawing , the vegetation layer has a pro - eminent part , the pressure of the vegetation against the lateral wall of the drum is more sizeable , the sensors 42 are very pushed - in , and activate the sensors 33 that send the information to the electronic board 43 , the leaf stripping head 1 moves back . on the right of the drawing , the vegetation is not in contact with the drum 2 of the leaf stripping head 1 , the sensors are relaxed , the leaf stripping head comes to press against the vegetation . when there is a hole in the vegetation , the sensors 42 are totally decompressed and the leaf stripping head gets closer to the axis of the vine row . in an advantageous and known manner ( wo - 01 / 87047a ), a cutting bar 34 or other cutting mechanism such as an alternating cutting bar can be arranged vertically in front of the rotary drum of the leaf stripping head or each leaf stripping head . this cutting bar 34 activated by a hydraulic motor m 3 is carried by an element 35 of the leaf stripping machine chassis and is arranged at a sufficient distance from the leaf stripping drum 2 , in a manner so that the cutting fragments do not disturb the work of the leaf stripper . when the leaf stripper comprises two leaf stripping heads , they are arranged on both sides of the vine row and can move in a manner to more or less fit tightly around the row and also to open and re - close at the input and output of the row , respectively . leaf stripping is thus possible on the two sides of the row , or , alternatively , on one or the other sides . during leaf stripping on only one side , the drum that is located on the other side of the paling can continue to roll over the vegetation , which makes it possible for the paling to be held between two drums and to not be pushed from one side or the other . the absence of leaf stripping action on the side where this action is not desired is obtained by stopping the intake vacuum of the inactive leaf stripping head . the leaf stripper according to the invention can be easily installed on an inter - row tractor , or on a spanning tractor , or on a multi - function tool holder . it can also be self - propelled .
the invention relates to a leaf stripper which is intended more specifically for stripping vine leaves . the inventive leaf stripper consists of a stripping head which is equipped with a rotary drum comprising an open - work cylindrical side wall , means of rotating said drum , suction means which can be used to generate a suction air stream that passes through the aforementioned open - work cylindrical side wall of the drum , a means of channeling the air stream through a portion modifying the side wall and a cutting means which is installed close to the side wall portion of the rotating suction drum and which is positioned parallel or essentially parallel to the axis of rotation of the drum . the invention is characterized in that the open - work cylindrical wall of the drum is made from a flexible , deformable material which is permeable to the air stream .